# would no longer match).
BUILD_logger ?= n
BUILD_proc_tsm ?= n
+BUILD_kdbus ?= n
obj-$(BUILD_logger) += logger.o
obj-$(BUILD_proc_tsm) += proc-tsm.o
+obj-$(BUILD_kdbus) += kdbus/
all:
make -C $(KERNELDIR) M=$(PWD) modules
--- /dev/null
+kdbus-y := \
+ bus.o \
+ connection.o \
+ endpoint.o \
+ fs.o \
+ handle.o \
+ item.o \
+ main.o \
+ match.o \
+ message.o \
+ metadata.o \
+ names.o \
+ node.o \
+ notify.o \
+ domain.o \
+ policy.o \
+ pool.o \
+ reply.o \
+ queue.o \
+ util.o
+
+obj-m += kdbus.o
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/cred.h>
+#include <linux/fs.h>
+#include <linux/hashtable.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+
+#include "bus.h"
+#include "notify.h"
+#include "connection.h"
+#include "domain.h"
+#include "endpoint.h"
+#include "handle.h"
+#include "item.h"
+#include "match.h"
+#include "message.h"
+#include "metadata.h"
+#include "names.h"
+#include "policy.h"
+#include "util.h"
+
+static void kdbus_bus_free(struct kdbus_node *node)
+{
+ struct kdbus_bus *bus = container_of(node, struct kdbus_bus, node);
+
+ WARN_ON(!list_empty(&bus->monitors_list));
+ WARN_ON(!hash_empty(bus->conn_hash));
+
+ kdbus_notify_free(bus);
+
+ kdbus_user_unref(bus->creator);
+ kdbus_name_registry_free(bus->name_registry);
+ kdbus_domain_unref(bus->domain);
+ kdbus_policy_db_clear(&bus->policy_db);
+ kdbus_meta_proc_unref(bus->creator_meta);
+ kfree(bus);
+}
+
+static void kdbus_bus_release(struct kdbus_node *node, bool was_active)
+{
+ struct kdbus_bus *bus = container_of(node, struct kdbus_bus, node);
+
+ if (was_active)
+ atomic_dec(&bus->creator->buses);
+}
+
+static struct kdbus_bus *kdbus_bus_new(struct kdbus_domain *domain,
+ const char *name,
+ struct kdbus_bloom_parameter *bloom,
+ const u64 *pattach_owner,
+ u64 flags, kuid_t uid, kgid_t gid)
+{
+ struct kdbus_bus *b;
+ u64 attach_owner;
+ int ret;
+
+ if (bloom->size < 8 || bloom->size > KDBUS_BUS_BLOOM_MAX_SIZE ||
+ !KDBUS_IS_ALIGNED8(bloom->size) || bloom->n_hash < 1)
+ return ERR_PTR(-EINVAL);
+
+ ret = kdbus_sanitize_attach_flags(pattach_owner ? *pattach_owner : 0,
+ &attach_owner);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ ret = kdbus_verify_uid_prefix(name, domain->user_namespace, uid);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ b = kzalloc(sizeof(*b), GFP_KERNEL);
+ if (!b)
+ return ERR_PTR(-ENOMEM);
+
+ kdbus_node_init(&b->node, KDBUS_NODE_BUS);
+
+ b->node.free_cb = kdbus_bus_free;
+ b->node.release_cb = kdbus_bus_release;
+ b->node.uid = uid;
+ b->node.gid = gid;
+ b->node.mode = S_IRUSR | S_IXUSR;
+
+ if (flags & (KDBUS_MAKE_ACCESS_GROUP | KDBUS_MAKE_ACCESS_WORLD))
+ b->node.mode |= S_IRGRP | S_IXGRP;
+ if (flags & KDBUS_MAKE_ACCESS_WORLD)
+ b->node.mode |= S_IROTH | S_IXOTH;
+
+ b->id = atomic64_inc_return(&domain->last_id);
+ b->bus_flags = flags;
+ b->attach_flags_owner = attach_owner;
+ generate_random_uuid(b->id128);
+ b->bloom = *bloom;
+ b->domain = kdbus_domain_ref(domain);
+
+ kdbus_policy_db_init(&b->policy_db);
+
+ init_rwsem(&b->conn_rwlock);
+ hash_init(b->conn_hash);
+ INIT_LIST_HEAD(&b->monitors_list);
+
+ INIT_LIST_HEAD(&b->notify_list);
+ spin_lock_init(&b->notify_lock);
+ mutex_init(&b->notify_flush_lock);
+
+ ret = kdbus_node_link(&b->node, &domain->node, name);
+ if (ret < 0)
+ goto exit_unref;
+
+ /* cache the metadata/credentials of the creator */
+ b->creator_meta = kdbus_meta_proc_new();
+ if (IS_ERR(b->creator_meta)) {
+ ret = PTR_ERR(b->creator_meta);
+ b->creator_meta = NULL;
+ goto exit_unref;
+ }
+
+ ret = kdbus_meta_proc_collect(b->creator_meta,
+ KDBUS_ATTACH_CREDS |
+ KDBUS_ATTACH_PIDS |
+ KDBUS_ATTACH_AUXGROUPS |
+ KDBUS_ATTACH_TID_COMM |
+ KDBUS_ATTACH_PID_COMM |
+ KDBUS_ATTACH_EXE |
+ KDBUS_ATTACH_CMDLINE |
+ KDBUS_ATTACH_CGROUP |
+ KDBUS_ATTACH_CAPS |
+ KDBUS_ATTACH_SECLABEL |
+ KDBUS_ATTACH_AUDIT);
+ if (ret < 0)
+ goto exit_unref;
+
+ b->name_registry = kdbus_name_registry_new();
+ if (IS_ERR(b->name_registry)) {
+ ret = PTR_ERR(b->name_registry);
+ b->name_registry = NULL;
+ goto exit_unref;
+ }
+
+ /*
+ * Bus-limits of the creator are accounted on its real UID, just like
+ * all other per-user limits.
+ */
+ b->creator = kdbus_user_lookup(domain, current_uid());
+ if (IS_ERR(b->creator)) {
+ ret = PTR_ERR(b->creator);
+ b->creator = NULL;
+ goto exit_unref;
+ }
+
+ return b;
+
+exit_unref:
+ kdbus_node_deactivate(&b->node);
+ kdbus_node_unref(&b->node);
+ return ERR_PTR(ret);
+}
+
+/**
+ * kdbus_bus_ref() - increase the reference counter of a kdbus_bus
+ * @bus: The bus to reference
+ *
+ * Every user of a bus, except for its creator, must add a reference to the
+ * kdbus_bus using this function.
+ *
+ * Return: the bus itself
+ */
+struct kdbus_bus *kdbus_bus_ref(struct kdbus_bus *bus)
+{
+ if (bus)
+ kdbus_node_ref(&bus->node);
+ return bus;
+}
+
+/**
+ * kdbus_bus_unref() - decrease the reference counter of a kdbus_bus
+ * @bus: The bus to unref
+ *
+ * Release a reference. If the reference count drops to 0, the bus will be
+ * freed.
+ *
+ * Return: NULL
+ */
+struct kdbus_bus *kdbus_bus_unref(struct kdbus_bus *bus)
+{
+ if (bus)
+ kdbus_node_unref(&bus->node);
+ return NULL;
+}
+
+/**
+ * kdbus_bus_find_conn_by_id() - find a connection with a given id
+ * @bus: The bus to look for the connection
+ * @id: The 64-bit connection id
+ *
+ * Looks up a connection with a given id. The returned connection
+ * is ref'ed, and needs to be unref'ed by the user. Returns NULL if
+ * the connection can't be found.
+ */
+struct kdbus_conn *kdbus_bus_find_conn_by_id(struct kdbus_bus *bus, u64 id)
+{
+ struct kdbus_conn *conn, *found = NULL;
+
+ down_read(&bus->conn_rwlock);
+ hash_for_each_possible(bus->conn_hash, conn, hentry, id)
+ if (conn->id == id) {
+ found = kdbus_conn_ref(conn);
+ break;
+ }
+ up_read(&bus->conn_rwlock);
+
+ return found;
+}
+
+/**
+ * kdbus_bus_broadcast() - send a message to all subscribed connections
+ * @bus: The bus the connections are connected to
+ * @conn_src: The source connection, may be %NULL for kernel notifications
+ * @staging: Staging object containing the message to send
+ *
+ * Send message to all connections that are currently active on the bus.
+ * Connections must still have matches installed in order to let the message
+ * pass.
+ *
+ * The caller must hold the name-registry lock of @bus.
+ */
+void kdbus_bus_broadcast(struct kdbus_bus *bus,
+ struct kdbus_conn *conn_src,
+ struct kdbus_staging *staging)
+{
+ struct kdbus_conn *conn_dst;
+ unsigned int i;
+ int ret;
+
+ lockdep_assert_held(&bus->name_registry->rwlock);
+
+ /*
+ * Make sure broadcast are queued on monitors before we send it out to
+ * anyone else. Otherwise, connections might react to broadcasts before
+ * the monitor gets the broadcast queued. In the worst case, the
+ * monitor sees a reaction to the broadcast before the broadcast itself.
+ * We don't give ordering guarantees across connections (and monitors
+ * can re-construct order via sequence numbers), but we should at least
+ * try to avoid re-ordering for monitors.
+ */
+ kdbus_bus_eavesdrop(bus, conn_src, staging);
+
+ down_read(&bus->conn_rwlock);
+ hash_for_each(bus->conn_hash, i, conn_dst, hentry) {
+ if (!kdbus_conn_is_ordinary(conn_dst))
+ continue;
+
+ /*
+ * Check if there is a match for the kmsg object in
+ * the destination connection match db
+ */
+ if (!kdbus_match_db_match_msg(conn_dst->match_db, conn_src,
+ staging))
+ continue;
+
+ if (conn_src) {
+ /*
+ * Anyone can send broadcasts, as they have no
+ * destination. But a receiver needs TALK access to
+ * the sender in order to receive broadcasts.
+ */
+ if (!kdbus_conn_policy_talk(conn_dst, NULL, conn_src))
+ continue;
+ } else {
+ /*
+ * Check if there is a policy db that prevents the
+ * destination connection from receiving this kernel
+ * notification
+ */
+ if (!kdbus_conn_policy_see_notification(conn_dst, NULL,
+ staging->msg))
+ continue;
+ }
+
+ ret = kdbus_conn_entry_insert(conn_src, conn_dst, staging,
+ NULL, NULL);
+ if (ret < 0)
+ kdbus_conn_lost_message(conn_dst);
+ }
+ up_read(&bus->conn_rwlock);
+}
+
+/**
+ * kdbus_bus_eavesdrop() - send a message to all subscribed monitors
+ * @bus: The bus the monitors are connected to
+ * @conn_src: The source connection, may be %NULL for kernel notifications
+ * @staging: Staging object containing the message to send
+ *
+ * Send message to all monitors that are currently active on the bus. Monitors
+ * must still have matches installed in order to let the message pass.
+ *
+ * The caller must hold the name-registry lock of @bus.
+ */
+void kdbus_bus_eavesdrop(struct kdbus_bus *bus,
+ struct kdbus_conn *conn_src,
+ struct kdbus_staging *staging)
+{
+ struct kdbus_conn *conn_dst;
+ int ret;
+
+ /*
+ * Monitor connections get all messages; ignore possible errors
+ * when sending messages to monitor connections.
+ */
+
+ lockdep_assert_held(&bus->name_registry->rwlock);
+
+ down_read(&bus->conn_rwlock);
+ list_for_each_entry(conn_dst, &bus->monitors_list, monitor_entry) {
+ ret = kdbus_conn_entry_insert(conn_src, conn_dst, staging,
+ NULL, NULL);
+ if (ret < 0)
+ kdbus_conn_lost_message(conn_dst);
+ }
+ up_read(&bus->conn_rwlock);
+}
+
+/**
+ * kdbus_cmd_bus_make() - handle KDBUS_CMD_BUS_MAKE
+ * @domain: domain to operate on
+ * @argp: command payload
+ *
+ * Return: NULL or newly created bus on success, ERR_PTR on failure.
+ */
+struct kdbus_bus *kdbus_cmd_bus_make(struct kdbus_domain *domain,
+ void __user *argp)
+{
+ struct kdbus_bus *bus = NULL;
+ struct kdbus_cmd *cmd;
+ struct kdbus_ep *ep = NULL;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_MAKE_NAME, .mandatory = true },
+ { .type = KDBUS_ITEM_BLOOM_PARAMETER, .mandatory = true },
+ { .type = KDBUS_ITEM_ATTACH_FLAGS_SEND },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_MAKE_ACCESS_GROUP |
+ KDBUS_MAKE_ACCESS_WORLD,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0)
+ return NULL;
+
+ bus = kdbus_bus_new(domain,
+ argv[1].item->str, &argv[2].item->bloom_parameter,
+ argv[3].item ? argv[3].item->data64 : NULL,
+ cmd->flags, current_euid(), current_egid());
+ if (IS_ERR(bus)) {
+ ret = PTR_ERR(bus);
+ bus = NULL;
+ goto exit;
+ }
+
+ if (atomic_inc_return(&bus->creator->buses) > KDBUS_USER_MAX_BUSES) {
+ atomic_dec(&bus->creator->buses);
+ ret = -EMFILE;
+ goto exit;
+ }
+
+ if (!kdbus_node_activate(&bus->node)) {
+ atomic_dec(&bus->creator->buses);
+ ret = -ESHUTDOWN;
+ goto exit;
+ }
+
+ ep = kdbus_ep_new(bus, "bus", cmd->flags, bus->node.uid, bus->node.gid,
+ false);
+ if (IS_ERR(ep)) {
+ ret = PTR_ERR(ep);
+ ep = NULL;
+ goto exit;
+ }
+
+ if (!kdbus_node_activate(&ep->node)) {
+ ret = -ESHUTDOWN;
+ goto exit;
+ }
+
+ /*
+ * Drop our own reference, effectively causing the endpoint to be
+ * deactivated and released when the parent bus is.
+ */
+ ep = kdbus_ep_unref(ep);
+
+exit:
+ ret = kdbus_args_clear(&args, ret);
+ if (ret < 0) {
+ if (ep) {
+ kdbus_node_deactivate(&ep->node);
+ kdbus_ep_unref(ep);
+ }
+ if (bus) {
+ kdbus_node_deactivate(&bus->node);
+ kdbus_bus_unref(bus);
+ }
+ return ERR_PTR(ret);
+ }
+ return bus;
+}
+
+/**
+ * kdbus_cmd_bus_creator_info() - handle KDBUS_CMD_BUS_CREATOR_INFO
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_bus_creator_info(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_cmd_info *cmd;
+ struct kdbus_bus *bus = conn->ep->bus;
+ struct kdbus_pool_slice *slice = NULL;
+ struct kdbus_item *meta_items = NULL;
+ struct kdbus_item_header item_hdr;
+ struct kdbus_info info = {};
+ size_t meta_size, name_len, cnt = 0;
+ struct kvec kvec[6];
+ u64 attach_flags, size = 0;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ ret = kdbus_sanitize_attach_flags(cmd->attach_flags, &attach_flags);
+ if (ret < 0)
+ goto exit;
+
+ attach_flags &= bus->attach_flags_owner;
+
+ ret = kdbus_meta_emit(bus->creator_meta, NULL, NULL, conn,
+ attach_flags, &meta_items, &meta_size);
+ if (ret < 0)
+ goto exit;
+
+ name_len = strlen(bus->node.name) + 1;
+ info.id = bus->id;
+ info.flags = bus->bus_flags;
+ item_hdr.type = KDBUS_ITEM_MAKE_NAME;
+ item_hdr.size = KDBUS_ITEM_HEADER_SIZE + name_len;
+
+ kdbus_kvec_set(&kvec[cnt++], &info, sizeof(info), &size);
+ kdbus_kvec_set(&kvec[cnt++], &item_hdr, sizeof(item_hdr), &size);
+ kdbus_kvec_set(&kvec[cnt++], bus->node.name, name_len, &size);
+ cnt += !!kdbus_kvec_pad(&kvec[cnt], &size);
+ if (meta_size > 0) {
+ kdbus_kvec_set(&kvec[cnt++], meta_items, meta_size, &size);
+ cnt += !!kdbus_kvec_pad(&kvec[cnt], &size);
+ }
+
+ info.size = size;
+
+ slice = kdbus_pool_slice_alloc(conn->pool, size, false);
+ if (IS_ERR(slice)) {
+ ret = PTR_ERR(slice);
+ slice = NULL;
+ goto exit;
+ }
+
+ ret = kdbus_pool_slice_copy_kvec(slice, 0, kvec, cnt, size);
+ if (ret < 0)
+ goto exit;
+
+ kdbus_pool_slice_publish(slice, &cmd->offset, &cmd->info_size);
+
+ if (kdbus_member_set_user(&cmd->offset, argp, typeof(*cmd), offset) ||
+ kdbus_member_set_user(&cmd->info_size, argp,
+ typeof(*cmd), info_size))
+ ret = -EFAULT;
+
+exit:
+ kdbus_pool_slice_release(slice);
+ kfree(meta_items);
+ return kdbus_args_clear(&args, ret);
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_BUS_H
+#define __KDBUS_BUS_H
+
+#include <linux/hashtable.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/spinlock.h>
+#include <uapi/linux/kdbus.h>
+
+#include "metadata.h"
+#include "names.h"
+#include "node.h"
+#include "policy.h"
+
+struct kdbus_conn;
+struct kdbus_domain;
+struct kdbus_staging;
+struct kdbus_user;
+
+/**
+ * struct kdbus_bus - bus in a domain
+ * @node: kdbus_node
+ * @id: ID of this bus in the domain
+ * @bus_flags: Simple pass-through flags from userspace to userspace
+ * @attach_flags_owner: KDBUS_ATTACH_* flags of bus creator that other
+ * connections can see or query
+ * @id128: Unique random 128 bit ID of this bus
+ * @bloom: Bloom parameters
+ * @domain: Domain of this bus
+ * @creator: Creator of the bus
+ * @creator_meta: Meta information about the bus creator
+ * @last_message_id: Last used message id
+ * @policy_db: Policy database for this bus
+ * @name_registry: Name registry of this bus
+ * @conn_rwlock: Read/Write lock for all lists of child connections
+ * @conn_hash: Map of connection IDs
+ * @monitors_list: Connections that monitor this bus
+ * @notify_list: List of pending kernel-generated messages
+ * @notify_lock: Notification list lock
+ * @notify_flush_lock: Notification flushing lock
+ */
+struct kdbus_bus {
+ struct kdbus_node node;
+
+ /* static */
+ u64 id;
+ u64 bus_flags;
+ u64 attach_flags_owner;
+ u8 id128[16];
+ struct kdbus_bloom_parameter bloom;
+ struct kdbus_domain *domain;
+ struct kdbus_user *creator;
+ struct kdbus_meta_proc *creator_meta;
+
+ /* protected by own locks */
+ atomic64_t last_message_id;
+ struct kdbus_policy_db policy_db;
+ struct kdbus_name_registry *name_registry;
+
+ /* protected by conn_rwlock */
+ struct rw_semaphore conn_rwlock;
+ DECLARE_HASHTABLE(conn_hash, 8);
+ struct list_head monitors_list;
+
+ /* protected by notify_lock */
+ struct list_head notify_list;
+ spinlock_t notify_lock;
+ struct mutex notify_flush_lock;
+};
+
+struct kdbus_bus *kdbus_bus_ref(struct kdbus_bus *bus);
+struct kdbus_bus *kdbus_bus_unref(struct kdbus_bus *bus);
+
+struct kdbus_conn *kdbus_bus_find_conn_by_id(struct kdbus_bus *bus, u64 id);
+void kdbus_bus_broadcast(struct kdbus_bus *bus,
+ struct kdbus_conn *conn_src,
+ struct kdbus_staging *staging);
+void kdbus_bus_eavesdrop(struct kdbus_bus *bus,
+ struct kdbus_conn *conn_src,
+ struct kdbus_staging *staging);
+
+struct kdbus_bus *kdbus_cmd_bus_make(struct kdbus_domain *domain,
+ void __user *argp);
+int kdbus_cmd_bus_creator_info(struct kdbus_conn *conn, void __user *argp);
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/audit.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/fs_struct.h>
+#include <linux/hashtable.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/math64.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/path.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/shmem_fs.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+#include <linux/uio.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "endpoint.h"
+#include "handle.h"
+#include "match.h"
+#include "message.h"
+#include "metadata.h"
+#include "names.h"
+#include "domain.h"
+#include "item.h"
+#include "notify.h"
+#include "policy.h"
+#include "pool.h"
+#include "reply.h"
+#include "util.h"
+#include "queue.h"
+
+#define KDBUS_CONN_ACTIVE_BIAS (INT_MIN + 2)
+#define KDBUS_CONN_ACTIVE_NEW (INT_MIN + 1)
+
+/* Disable internal kdbus policy - possibilities of connections to own, see and
+ * talk to names are restricted by libdbuspolicy library and LSM hooks
+ */
+#define DISABLE_KDBUS_POLICY
+
+static struct kdbus_conn *kdbus_conn_new(struct kdbus_ep *ep,
+ struct file *file,
+ struct kdbus_cmd_hello *hello,
+ const char *name,
+ const struct kdbus_creds *creds,
+ const struct kdbus_pids *pids,
+ const char *seclabel,
+ const char *conn_description)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ static struct lock_class_key __key;
+#endif
+ struct kdbus_pool_slice *slice = NULL;
+ struct kdbus_bus *bus = ep->bus;
+ struct kdbus_conn *conn;
+ u64 attach_flags_send;
+ u64 attach_flags_recv;
+ u64 items_size = 0;
+ bool is_policy_holder;
+ bool is_activator;
+ bool is_monitor;
+ bool privileged;
+ bool owner;
+ struct kvec kvec;
+ int ret;
+
+ struct {
+ u64 size;
+ u64 type;
+ struct kdbus_bloom_parameter bloom;
+ } bloom_item;
+
+ privileged = kdbus_ep_is_privileged(ep, file);
+ owner = kdbus_ep_is_owner(ep, file);
+
+ is_monitor = hello->flags & KDBUS_HELLO_MONITOR;
+ is_activator = hello->flags & KDBUS_HELLO_ACTIVATOR;
+ is_policy_holder = hello->flags & KDBUS_HELLO_POLICY_HOLDER;
+
+ if (!hello->pool_size || !IS_ALIGNED(hello->pool_size, PAGE_SIZE))
+ return ERR_PTR(-EINVAL);
+ if (is_monitor + is_activator + is_policy_holder > 1)
+ return ERR_PTR(-EINVAL);
+ if (name && !is_activator && !is_policy_holder)
+ return ERR_PTR(-EINVAL);
+ if (!name && (is_activator || is_policy_holder))
+ return ERR_PTR(-EINVAL);
+ if (name && !kdbus_name_is_valid(name, true))
+ return ERR_PTR(-EINVAL);
+ if (is_monitor && ep->user)
+ return ERR_PTR(-EOPNOTSUPP);
+ if (!owner && (is_activator || is_policy_holder || is_monitor))
+ return ERR_PTR(-EPERM);
+ if (!owner && (creds || pids || seclabel))
+ return ERR_PTR(-EPERM);
+
+ ret = kdbus_sanitize_attach_flags(hello->attach_flags_send,
+ &attach_flags_send);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ ret = kdbus_sanitize_attach_flags(hello->attach_flags_recv,
+ &attach_flags_recv);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ conn = kzalloc(sizeof(*conn), GFP_KERNEL);
+ if (!conn)
+ return ERR_PTR(-ENOMEM);
+
+ kref_init(&conn->kref);
+ atomic_set(&conn->active, KDBUS_CONN_ACTIVE_NEW);
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ lockdep_init_map(&conn->dep_map, "s_active", &__key, 0);
+#endif
+ mutex_init(&conn->lock);
+ INIT_LIST_HEAD(&conn->names_list);
+ INIT_LIST_HEAD(&conn->reply_list);
+ atomic_set(&conn->request_count, 0);
+ atomic_set(&conn->lost_count, 0);
+ INIT_DELAYED_WORK(&conn->work, kdbus_reply_list_scan_work);
+ conn->cred = get_cred(file->f_cred);
+ conn->pid = get_pid(task_pid(current));
+ get_fs_root(current->fs, &conn->root_path);
+ init_waitqueue_head(&conn->wait);
+ kdbus_queue_init(&conn->queue);
+ conn->privileged = privileged;
+ conn->owner = owner;
+ conn->ep = kdbus_ep_ref(ep);
+ conn->id = atomic64_inc_return(&bus->domain->last_id);
+ conn->flags = hello->flags;
+ atomic64_set(&conn->attach_flags_send, attach_flags_send);
+ atomic64_set(&conn->attach_flags_recv, attach_flags_recv);
+ INIT_LIST_HEAD(&conn->monitor_entry);
+
+ if (conn_description) {
+ conn->description = kstrdup(conn_description, GFP_KERNEL);
+ if (!conn->description) {
+ ret = -ENOMEM;
+ goto exit_unref;
+ }
+ }
+
+ conn->pool = kdbus_pool_new(conn->description, hello->pool_size);
+ if (IS_ERR(conn->pool)) {
+ ret = PTR_ERR(conn->pool);
+ conn->pool = NULL;
+ goto exit_unref;
+ }
+
+ conn->match_db = kdbus_match_db_new();
+ if (IS_ERR(conn->match_db)) {
+ ret = PTR_ERR(conn->match_db);
+ conn->match_db = NULL;
+ goto exit_unref;
+ }
+
+ /* return properties of this connection to the caller */
+ hello->bus_flags = bus->bus_flags;
+ hello->id = conn->id;
+
+ BUILD_BUG_ON(sizeof(bus->id128) != sizeof(hello->id128));
+ memcpy(hello->id128, bus->id128, sizeof(hello->id128));
+
+ /* privileged processes can impersonate somebody else */
+ if (creds || pids || seclabel) {
+ conn->meta_fake = kdbus_meta_fake_new();
+ if (IS_ERR(conn->meta_fake)) {
+ ret = PTR_ERR(conn->meta_fake);
+ conn->meta_fake = NULL;
+ goto exit_unref;
+ }
+
+ ret = kdbus_meta_fake_collect(conn->meta_fake,
+ creds, pids, seclabel);
+ if (ret < 0)
+ goto exit_unref;
+ } else {
+ conn->meta_proc = kdbus_meta_proc_new();
+ if (IS_ERR(conn->meta_proc)) {
+ ret = PTR_ERR(conn->meta_proc);
+ conn->meta_proc = NULL;
+ goto exit_unref;
+ }
+
+ ret = kdbus_meta_proc_collect(conn->meta_proc,
+ KDBUS_ATTACH_CREDS |
+ KDBUS_ATTACH_PIDS |
+ KDBUS_ATTACH_AUXGROUPS |
+ KDBUS_ATTACH_TID_COMM |
+ KDBUS_ATTACH_PID_COMM |
+ KDBUS_ATTACH_EXE |
+ KDBUS_ATTACH_CMDLINE |
+ KDBUS_ATTACH_CGROUP |
+ KDBUS_ATTACH_CAPS |
+ KDBUS_ATTACH_SECLABEL |
+ KDBUS_ATTACH_AUDIT);
+ if (ret < 0)
+ goto exit_unref;
+ }
+
+ /*
+ * Account the connection against the current user (UID), or for
+ * custom endpoints use the anonymous user assigned to the endpoint.
+ * Note that limits are always accounted against the real UID, not
+ * the effective UID (cred->user always points to the accounting of
+ * cred->uid, not cred->euid).
+ * In case the caller is privileged, we allow changing the accounting
+ * to the faked user.
+ */
+ if (ep->user) {
+ conn->user = kdbus_user_ref(ep->user);
+ } else {
+ kuid_t uid;
+
+ if (conn->meta_fake && uid_valid(conn->meta_fake->uid) &&
+ conn->privileged)
+ uid = conn->meta_fake->uid;
+ else
+ uid = conn->cred->uid;
+
+ conn->user = kdbus_user_lookup(ep->bus->domain, uid);
+ if (IS_ERR(conn->user)) {
+ ret = PTR_ERR(conn->user);
+ conn->user = NULL;
+ goto exit_unref;
+ }
+ }
+
+ if (atomic_inc_return(&conn->user->connections) > KDBUS_USER_MAX_CONN) {
+ /* decremented by destructor as conn->user is valid */
+ ret = -EMFILE;
+ goto exit_unref;
+ }
+
+ bloom_item.size = sizeof(bloom_item);
+ bloom_item.type = KDBUS_ITEM_BLOOM_PARAMETER;
+ bloom_item.bloom = bus->bloom;
+ kdbus_kvec_set(&kvec, &bloom_item, bloom_item.size, &items_size);
+
+ slice = kdbus_pool_slice_alloc(conn->pool, items_size, false);
+ if (IS_ERR(slice)) {
+ ret = PTR_ERR(slice);
+ slice = NULL;
+ goto exit_unref;
+ }
+
+ ret = kdbus_pool_slice_copy_kvec(slice, 0, &kvec, 1, items_size);
+ if (ret < 0)
+ goto exit_unref;
+
+ kdbus_pool_slice_publish(slice, &hello->offset, &hello->items_size);
+ kdbus_pool_slice_release(slice);
+
+ return conn;
+
+exit_unref:
+ kdbus_pool_slice_release(slice);
+ kdbus_conn_unref(conn);
+ return ERR_PTR(ret);
+}
+
+static void __kdbus_conn_free(struct kref *kref)
+{
+ struct kdbus_conn *conn = container_of(kref, struct kdbus_conn, kref);
+
+ WARN_ON(kdbus_conn_active(conn));
+ WARN_ON(delayed_work_pending(&conn->work));
+ WARN_ON(!list_empty(&conn->queue.msg_list));
+ WARN_ON(!list_empty(&conn->names_list));
+ WARN_ON(!list_empty(&conn->reply_list));
+
+ if (conn->user) {
+ atomic_dec(&conn->user->connections);
+ kdbus_user_unref(conn->user);
+ }
+
+ kdbus_meta_fake_free(conn->meta_fake);
+ kdbus_meta_proc_unref(conn->meta_proc);
+ kdbus_match_db_free(conn->match_db);
+ kdbus_pool_free(conn->pool);
+ kdbus_ep_unref(conn->ep);
+ path_put(&conn->root_path);
+ put_pid(conn->pid);
+ put_cred(conn->cred);
+ kfree(conn->description);
+ kfree(conn->quota);
+ kfree(conn);
+}
+
+/**
+ * kdbus_conn_ref() - take a connection reference
+ * @conn: Connection, may be %NULL
+ *
+ * Return: the connection itself
+ */
+struct kdbus_conn *kdbus_conn_ref(struct kdbus_conn *conn)
+{
+ if (conn)
+ kref_get(&conn->kref);
+ return conn;
+}
+
+/**
+ * kdbus_conn_unref() - drop a connection reference
+ * @conn: Connection (may be NULL)
+ *
+ * When the last reference is dropped, the connection's internal structure
+ * is freed.
+ *
+ * Return: NULL
+ */
+struct kdbus_conn *kdbus_conn_unref(struct kdbus_conn *conn)
+{
+ if (conn)
+ kref_put(&conn->kref, __kdbus_conn_free);
+ return NULL;
+}
+
+/**
+ * kdbus_conn_active() - connection is not disconnected
+ * @conn: Connection to check
+ *
+ * Return true if the connection was not disconnected, yet. Note that a
+ * connection might be disconnected asynchronously, unless you hold the
+ * connection lock. If that's not suitable for you, see kdbus_conn_acquire() to
+ * suppress connection shutdown for a short period.
+ *
+ * Return: true if the connection is still active
+ */
+bool kdbus_conn_active(const struct kdbus_conn *conn)
+{
+ return atomic_read(&conn->active) >= 0;
+}
+
+/**
+ * kdbus_conn_acquire() - acquire an active connection reference
+ * @conn: Connection
+ *
+ * Users can close a connection via KDBUS_BYEBYE (or by destroying the
+ * endpoint/bus/...) at any time. Whenever this happens, we should deny any
+ * user-visible action on this connection and signal ECONNRESET instead.
+ * To avoid testing for connection availability everytime you take the
+ * connection-lock, you can acquire a connection for short periods.
+ *
+ * By calling kdbus_conn_acquire(), you gain an "active reference" to the
+ * connection. You must also hold a regular reference at any time! As long as
+ * you hold the active-ref, the connection will not be shut down. However, if
+ * the connection was shut down, you can never acquire an active-ref again.
+ *
+ * kdbus_conn_disconnect() disables the connection and then waits for all active
+ * references to be dropped. It will also wake up any pending operation.
+ * However, you must not sleep for an indefinite period while holding an
+ * active-reference. Otherwise, kdbus_conn_disconnect() might stall. If you need
+ * to sleep for an indefinite period, either release the reference and try to
+ * acquire it again after waking up, or make kdbus_conn_disconnect() wake up
+ * your wait-queue.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_conn_acquire(struct kdbus_conn *conn)
+{
+ if (!atomic_inc_unless_negative(&conn->active))
+ return -ECONNRESET;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ rwsem_acquire_read(&conn->dep_map, 0, 1, _RET_IP_);
+#endif
+
+ return 0;
+}
+
+/**
+ * kdbus_conn_release() - release an active connection reference
+ * @conn: Connection
+ *
+ * This releases an active reference that has been acquired via
+ * kdbus_conn_acquire(). If the connection was already disabled and this is the
+ * last active-ref that is dropped, the disconnect-waiter will be woken up and
+ * properly close the connection.
+ */
+void kdbus_conn_release(struct kdbus_conn *conn)
+{
+ int v;
+
+ if (!conn)
+ return;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ rwsem_release(&conn->dep_map, 1, _RET_IP_);
+#endif
+
+ v = atomic_dec_return(&conn->active);
+ if (v != KDBUS_CONN_ACTIVE_BIAS)
+ return;
+
+ wake_up_all(&conn->wait);
+}
+
+static int kdbus_conn_connect(struct kdbus_conn *conn, const char *name)
+{
+ struct kdbus_ep *ep = conn->ep;
+ struct kdbus_bus *bus = ep->bus;
+ int ret;
+
+ if (WARN_ON(atomic_read(&conn->active) != KDBUS_CONN_ACTIVE_NEW))
+ return -EALREADY;
+
+ /* make sure the ep-node is active while we add our connection */
+ if (!kdbus_node_acquire(&ep->node))
+ return -ESHUTDOWN;
+
+ /* lock order: domain -> bus -> ep -> names -> conn */
+ mutex_lock(&ep->lock);
+ down_write(&bus->conn_rwlock);
+
+ /* link into monitor list */
+ if (kdbus_conn_is_monitor(conn))
+ list_add_tail(&conn->monitor_entry, &bus->monitors_list);
+
+ /* link into bus and endpoint */
+ list_add_tail(&conn->ep_entry, &ep->conn_list);
+ hash_add(bus->conn_hash, &conn->hentry, conn->id);
+
+ /* enable lookups and acquire active ref */
+ atomic_set(&conn->active, 1);
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ rwsem_acquire_read(&conn->dep_map, 0, 1, _RET_IP_);
+#endif
+
+ up_write(&bus->conn_rwlock);
+ mutex_unlock(&ep->lock);
+
+ kdbus_node_release(&ep->node);
+
+ /*
+ * Notify subscribers about the new active connection, unless it is
+ * a monitor. Monitors are invisible on the bus, can't be addressed
+ * directly, and won't cause any notifications.
+ */
+ if (!kdbus_conn_is_monitor(conn)) {
+ ret = kdbus_notify_id_change(bus, KDBUS_ITEM_ID_ADD,
+ conn->id, conn->flags);
+ if (ret < 0)
+ goto exit_disconnect;
+ }
+
+ if (kdbus_conn_is_activator(conn)) {
+ u64 flags = KDBUS_NAME_ACTIVATOR;
+
+ if (WARN_ON(!name)) {
+ ret = -EINVAL;
+ goto exit_disconnect;
+ }
+
+ ret = kdbus_name_acquire(bus->name_registry, conn, name,
+ flags, NULL);
+ if (ret < 0)
+ goto exit_disconnect;
+ }
+
+ kdbus_conn_release(conn);
+ kdbus_notify_flush(bus);
+ return 0;
+
+exit_disconnect:
+ kdbus_conn_release(conn);
+ kdbus_conn_disconnect(conn, false);
+ return ret;
+}
+
+/**
+ * kdbus_conn_disconnect() - disconnect a connection
+ * @conn: The connection to disconnect
+ * @ensure_queue_empty: Flag to indicate if the call should fail in
+ * case the connection's message list is not
+ * empty
+ *
+ * If @ensure_msg_list_empty is true, and the connection has pending messages,
+ * -EBUSY is returned.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+int kdbus_conn_disconnect(struct kdbus_conn *conn, bool ensure_queue_empty)
+{
+ struct kdbus_queue_entry *entry, *tmp;
+ struct kdbus_bus *bus = conn->ep->bus;
+ struct kdbus_reply *r, *r_tmp;
+ struct kdbus_conn *c;
+ int i, v;
+
+ mutex_lock(&conn->lock);
+ v = atomic_read(&conn->active);
+ if (v == KDBUS_CONN_ACTIVE_NEW) {
+ /* was never connected */
+ mutex_unlock(&conn->lock);
+ return 0;
+ }
+ if (v < 0) {
+ /* already dead */
+ mutex_unlock(&conn->lock);
+ return -ECONNRESET;
+ }
+ if (ensure_queue_empty && !list_empty(&conn->queue.msg_list)) {
+ /* still busy */
+ mutex_unlock(&conn->lock);
+ return -EBUSY;
+ }
+
+ atomic_add(KDBUS_CONN_ACTIVE_BIAS, &conn->active);
+ mutex_unlock(&conn->lock);
+
+ wake_up_interruptible(&conn->wait);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ rwsem_acquire(&conn->dep_map, 0, 0, _RET_IP_);
+ if (atomic_read(&conn->active) != KDBUS_CONN_ACTIVE_BIAS)
+ lock_contended(&conn->dep_map, _RET_IP_);
+#endif
+
+ wait_event(conn->wait,
+ atomic_read(&conn->active) == KDBUS_CONN_ACTIVE_BIAS);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ lock_acquired(&conn->dep_map, _RET_IP_);
+ rwsem_release(&conn->dep_map, 1, _RET_IP_);
+#endif
+
+ cancel_delayed_work_sync(&conn->work);
+ kdbus_policy_remove_owner(&conn->ep->bus->policy_db, conn);
+
+ /* lock order: domain -> bus -> ep -> names -> conn */
+ mutex_lock(&conn->ep->lock);
+ down_write(&bus->conn_rwlock);
+
+ /* remove from bus and endpoint */
+ hash_del(&conn->hentry);
+ list_del(&conn->monitor_entry);
+ list_del(&conn->ep_entry);
+
+ up_write(&bus->conn_rwlock);
+ mutex_unlock(&conn->ep->lock);
+
+ /*
+ * Remove all names associated with this connection; this possibly
+ * moves queued messages back to the activator connection.
+ */
+ kdbus_name_release_all(bus->name_registry, conn);
+
+ /* if we die while other connections wait for our reply, notify them */
+ mutex_lock(&conn->lock);
+ list_for_each_entry_safe(entry, tmp, &conn->queue.msg_list, entry) {
+ if (entry->reply)
+ kdbus_notify_reply_dead(bus,
+ entry->reply->reply_dst->id,
+ entry->reply->cookie);
+ kdbus_queue_entry_free(entry);
+ }
+
+ list_for_each_entry_safe(r, r_tmp, &conn->reply_list, entry)
+ kdbus_reply_unlink(r);
+ mutex_unlock(&conn->lock);
+
+ /* lock order: domain -> bus -> ep -> names -> conn */
+ down_read(&bus->conn_rwlock);
+ hash_for_each(bus->conn_hash, i, c, hentry) {
+ mutex_lock(&c->lock);
+ list_for_each_entry_safe(r, r_tmp, &c->reply_list, entry) {
+ if (r->reply_src != conn)
+ continue;
+
+ if (r->sync)
+ kdbus_sync_reply_wakeup(r, -EPIPE);
+ else
+ /* send a 'connection dead' notification */
+ kdbus_notify_reply_dead(bus, c->id, r->cookie);
+
+ kdbus_reply_unlink(r);
+ }
+ mutex_unlock(&c->lock);
+ }
+ up_read(&bus->conn_rwlock);
+
+ if (!kdbus_conn_is_monitor(conn))
+ kdbus_notify_id_change(bus, KDBUS_ITEM_ID_REMOVE,
+ conn->id, conn->flags);
+
+ kdbus_notify_flush(bus);
+
+ return 0;
+}
+
+/**
+ * kdbus_conn_has_name() - check if a connection owns a name
+ * @conn: Connection
+ * @name: Well-know name to check for
+ *
+ * The caller must hold the registry lock of conn->ep->bus.
+ *
+ * Return: true if the name is currently owned by the connection
+ */
+bool kdbus_conn_has_name(struct kdbus_conn *conn, const char *name)
+{
+ struct kdbus_name_owner *owner;
+
+ lockdep_assert_held(&conn->ep->bus->name_registry->rwlock);
+
+ list_for_each_entry(owner, &conn->names_list, conn_entry)
+ if (!(owner->flags & KDBUS_NAME_IN_QUEUE) &&
+ !strcmp(name, owner->name->name))
+ return true;
+
+ return false;
+}
+
+struct kdbus_quota {
+ u32 memory;
+ u16 msgs;
+ u8 fds;
+};
+
+/**
+ * kdbus_conn_quota_inc() - increase quota accounting
+ * @c: connection owning the quota tracking
+ * @u: user to account for (or NULL for kernel accounting)
+ * @memory: size of memory to account for
+ * @fds: number of FDs to account for
+ *
+ * This call manages the quotas on resource @c. That is, it's used if other
+ * users want to use the resources of connection @c, which so far only concerns
+ * the receive queue of the destination.
+ *
+ * This increases the quota-accounting for user @u by @memory bytes and @fds
+ * file descriptors. If the user has already reached the quota limits, this call
+ * will not do any accounting but return a negative error code indicating the
+ * failure.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_conn_quota_inc(struct kdbus_conn *c, struct kdbus_user *u,
+ size_t memory, size_t fds)
+{
+ struct kdbus_quota *quota;
+ size_t available, accounted;
+ unsigned int id;
+
+ /*
+ * Pool Layout:
+ * 50% of a pool is always owned by the connection. It is reserved for
+ * kernel queries, handling received messages and other tasks that are
+ * under control of the pool owner. The other 50% of the pool are used
+ * as incoming queue.
+ * As we optionally support user-space based policies, we need fair
+ * allocation schemes. Furthermore, resource utilization should be
+ * maximized, so only minimal resources stay reserved. However, we need
+ * to adapt to a dynamic number of users, as we cannot know how many
+ * users will talk to a connection. Therefore, the current allocation
+ * works like this:
+ * We limit the number of bytes in a destination's pool per sending
+ * user. The space available for a user is 33% of the unused pool space
+ * (whereas the space used by the user itself is also treated as
+ * 'unused'). This way, we favor users coming first, but keep enough
+ * pool space available for any following users. Given that messages are
+ * dequeued in FIFO order, this should balance nicely if the number of
+ * users grows. At the same time, this algorithm guarantees that the
+ * space available to a connection is reduced dynamically, the more
+ * concurrent users talk to a connection.
+ */
+
+ /* per user-accounting is expensive, so we keep state small */
+ BUILD_BUG_ON(sizeof(quota->memory) != 4);
+ BUILD_BUG_ON(sizeof(quota->msgs) != 2);
+ BUILD_BUG_ON(sizeof(quota->fds) != 1);
+ BUILD_BUG_ON(KDBUS_CONN_MAX_MSGS > U16_MAX);
+ BUILD_BUG_ON(KDBUS_CONN_MAX_FDS_PER_USER > U8_MAX);
+
+ id = u ? u->id : KDBUS_USER_KERNEL_ID;
+ if (id >= c->n_quota) {
+ unsigned int users;
+
+ users = max(KDBUS_ALIGN8(id) + 8, id);
+ quota = krealloc(c->quota, users * sizeof(*quota),
+ GFP_KERNEL | __GFP_ZERO);
+ if (!quota)
+ return -ENOMEM;
+
+ c->n_quota = users;
+ c->quota = quota;
+ }
+
+ quota = &c->quota[id];
+ kdbus_pool_accounted(c->pool, &available, &accounted);
+
+ /* half the pool is _always_ reserved for the pool owner */
+ available /= 2;
+
+ /*
+ * Pool owner slices are un-accounted slices; they can claim more
+ * than 50% of the queue. However, the slices we're dealing with here
+ * belong to the incoming queue, hence they are 'accounted' slices
+ * to which the 50%-limit applies.
+ */
+ if (available < accounted)
+ return -ENOBUFS;
+
+ /* 1/3 of the remaining space (including your own memory) */
+ available = (available - accounted + quota->memory) / 3;
+
+ if (available < quota->memory ||
+ available - quota->memory < memory ||
+ quota->memory + memory > U32_MAX)
+ return -ENOBUFS;
+ if (quota->msgs >= KDBUS_CONN_MAX_MSGS)
+ return -ENOBUFS;
+ if (quota->fds + fds < quota->fds ||
+ quota->fds + fds > KDBUS_CONN_MAX_FDS_PER_USER)
+ return -EMFILE;
+
+ quota->memory += memory;
+ quota->fds += fds;
+ ++quota->msgs;
+ return 0;
+}
+
+/**
+ * kdbus_conn_quota_dec() - decrease quota accounting
+ * @c: connection owning the quota tracking
+ * @u: user which was accounted for (or NULL for kernel accounting)
+ * @memory: size of memory which was accounted for
+ * @fds: number of FDs which were accounted for
+ *
+ * This does the reverse of kdbus_conn_quota_inc(). You have to release any
+ * accounted resources that you called kdbus_conn_quota_inc() for. However, you
+ * must not call kdbus_conn_quota_dec() if the accounting failed (that is,
+ * kdbus_conn_quota_inc() failed).
+ */
+void kdbus_conn_quota_dec(struct kdbus_conn *c, struct kdbus_user *u,
+ size_t memory, size_t fds)
+{
+ struct kdbus_quota *quota;
+ unsigned int id;
+
+ id = u ? u->id : KDBUS_USER_KERNEL_ID;
+ if (WARN_ON(id >= c->n_quota))
+ return;
+
+ quota = &c->quota[id];
+
+ if (!WARN_ON(quota->msgs == 0))
+ --quota->msgs;
+ if (!WARN_ON(quota->memory < memory))
+ quota->memory -= memory;
+ if (!WARN_ON(quota->fds < fds))
+ quota->fds -= fds;
+}
+
+/**
+ * kdbus_conn_lost_message() - handle lost messages
+ * @c: connection that lost a message
+ *
+ * kdbus is reliable. That means, we try hard to never lose messages. However,
+ * memory is limited, so we cannot rely on transmissions to never fail.
+ * Therefore, we use quota-limits to let callers know if their unicast message
+ * cannot be transmitted to a peer. This works fine for unicasts, but for
+ * broadcasts we cannot make the caller handle the transmission failure.
+ * Instead, we must let the destination know that it couldn't receive a
+ * broadcast.
+ * As this is an unlikely scenario, we keep it simple. A single lost-counter
+ * remembers the number of lost messages since the last call to RECV. The next
+ * message retrieval will notify the connection that it lost messages since the
+ * last message retrieval and thus should resync its state.
+ */
+void kdbus_conn_lost_message(struct kdbus_conn *c)
+{
+ if (atomic_inc_return(&c->lost_count) == 1)
+ wake_up_interruptible(&c->wait);
+}
+
+/* Callers should take the conn_dst lock */
+static struct kdbus_queue_entry *
+kdbus_conn_entry_make(struct kdbus_conn *conn_src,
+ struct kdbus_conn *conn_dst,
+ struct kdbus_staging *staging)
+{
+ /* The remote connection was disconnected */
+ if (!kdbus_conn_active(conn_dst))
+ return ERR_PTR(-ECONNRESET);
+
+ /*
+ * If the connection does not accept file descriptors but the message
+ * has some attached, refuse it.
+ *
+ * If this is a monitor connection, accept the message. In that
+ * case, all file descriptors will be set to -1 at receive time.
+ */
+ if (!kdbus_conn_is_monitor(conn_dst) &&
+ !(conn_dst->flags & KDBUS_HELLO_ACCEPT_FD) &&
+ staging->gaps && staging->gaps->n_fds > 0)
+ return ERR_PTR(-ECOMM);
+
+ return kdbus_queue_entry_new(conn_src, conn_dst, staging);
+}
+
+/*
+ * Synchronously responding to a message, allocate a queue entry
+ * and attach it to the reply tracking object.
+ * The connection's queue will never get to see it.
+ */
+static int kdbus_conn_entry_sync_attach(struct kdbus_conn *conn_dst,
+ struct kdbus_staging *staging,
+ struct kdbus_reply *reply_wake)
+{
+ struct kdbus_queue_entry *entry;
+ int remote_ret, ret = 0;
+
+ mutex_lock(&reply_wake->reply_dst->lock);
+
+ /*
+ * If we are still waiting then proceed, allocate a queue
+ * entry and attach it to the reply object
+ */
+ if (reply_wake->waiting) {
+ entry = kdbus_conn_entry_make(reply_wake->reply_src, conn_dst,
+ staging);
+ if (IS_ERR(entry))
+ ret = PTR_ERR(entry);
+ else
+ /* Attach the entry to the reply object */
+ reply_wake->queue_entry = entry;
+ } else {
+ ret = -ECONNRESET;
+ }
+
+ /*
+ * Update the reply object and wake up remote peer only
+ * on appropriate return codes
+ *
+ * * -ECOMM: if the replying connection failed with -ECOMM
+ * then wakeup remote peer with -EREMOTEIO
+ *
+ * We do this to differenciate between -ECOMM errors
+ * from the original sender perspective:
+ * -ECOMM error during the sync send and
+ * -ECOMM error during the sync reply, this last
+ * one is rewritten to -EREMOTEIO
+ *
+ * * Wake up on all other return codes.
+ */
+ remote_ret = ret;
+
+ if (ret == -ECOMM)
+ remote_ret = -EREMOTEIO;
+
+ kdbus_sync_reply_wakeup(reply_wake, remote_ret);
+ mutex_unlock(&reply_wake->reply_dst->lock);
+
+ return ret;
+}
+
+/**
+ * kdbus_conn_entry_insert() - enqueue a message into the receiver's pool
+ * @conn_src: The sending connection
+ * @conn_dst: The connection to queue into
+ * @staging: Message to send
+ * @reply: The reply tracker to attach to the queue entry
+ * @name: Destination name this msg is sent to, or NULL
+ *
+ * Return: 0 on success. negative error otherwise.
+ */
+int kdbus_conn_entry_insert(struct kdbus_conn *conn_src,
+ struct kdbus_conn *conn_dst,
+ struct kdbus_staging *staging,
+ struct kdbus_reply *reply,
+ const struct kdbus_name_entry *name)
+{
+ struct kdbus_queue_entry *entry;
+ int ret;
+
+ kdbus_conn_lock2(conn_src, conn_dst);
+
+ entry = kdbus_conn_entry_make(conn_src, conn_dst, staging);
+ if (IS_ERR(entry)) {
+ ret = PTR_ERR(entry);
+ goto exit_unlock;
+ }
+
+ if (reply) {
+ kdbus_reply_link(reply);
+ if (!reply->sync)
+ schedule_delayed_work(&conn_src->work, 0);
+ }
+
+ /*
+ * Record the sequence number of the registered name; it will
+ * be remembered by the queue, in case messages addressed to a
+ * name need to be moved from or to an activator.
+ */
+ if (name)
+ entry->dst_name_id = name->name_id;
+
+ kdbus_queue_entry_enqueue(entry, reply);
+ wake_up_interruptible(&conn_dst->wait);
+
+ ret = 0;
+
+exit_unlock:
+ kdbus_conn_unlock2(conn_src, conn_dst);
+ return ret;
+}
+
+static int kdbus_conn_wait_reply(struct kdbus_conn *conn_src,
+ struct kdbus_cmd_send *cmd_send,
+ struct file *ioctl_file,
+ struct file *cancel_fd,
+ struct kdbus_reply *reply_wait,
+ ktime_t expire)
+{
+ struct kdbus_queue_entry *entry;
+ struct poll_wqueues pwq = {};
+ int ret;
+
+ if (WARN_ON(!reply_wait))
+ return -EIO;
+
+ /*
+ * Block until the reply arrives. reply_wait is left untouched
+ * by the timeout scans that might be conducted for other,
+ * asynchronous replies of conn_src.
+ */
+
+ poll_initwait(&pwq);
+ poll_wait(ioctl_file, &conn_src->wait, &pwq.pt);
+
+ for (;;) {
+ /*
+ * Any of the following conditions will stop our synchronously
+ * blocking SEND command:
+ *
+ * a) The origin sender closed its connection
+ * b) The remote peer answered, setting reply_wait->waiting = 0
+ * c) The cancel FD was written to
+ * d) A signal was received
+ * e) The specified timeout was reached, and none of the above
+ * conditions kicked in.
+ */
+
+ /*
+ * We have already acquired an active reference when
+ * entering here, but another thread may call
+ * KDBUS_CMD_BYEBYE which does not acquire an active
+ * reference, therefore kdbus_conn_disconnect() will
+ * not wait for us.
+ */
+ if (!kdbus_conn_active(conn_src)) {
+ ret = -ECONNRESET;
+ break;
+ }
+
+ /*
+ * After the replying peer unset the waiting variable
+ * it will wake up us.
+ */
+ if (!reply_wait->waiting) {
+ ret = reply_wait->err;
+ break;
+ }
+
+ if (cancel_fd) {
+ unsigned int r;
+
+ r = cancel_fd->f_op->poll(cancel_fd, &pwq.pt);
+ if (r & POLLIN) {
+ ret = -ECANCELED;
+ break;
+ }
+ }
+
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+
+ if (!poll_schedule_timeout(&pwq, TASK_INTERRUPTIBLE,
+ &expire, 0)) {
+ ret = -ETIMEDOUT;
+ break;
+ }
+
+ /*
+ * Reset the poll worker func, so the waitqueues are not
+ * added to the poll table again. We just reuse what we've
+ * collected earlier for further iterations.
+ */
+ init_poll_funcptr(&pwq.pt, NULL);
+ }
+
+ poll_freewait(&pwq);
+
+ if (ret == -EINTR) {
+ /*
+ * Interrupted system call. Unref the reply object, and pass
+ * the return value down the chain. Mark the reply as
+ * interrupted, so the cleanup work can remove it, but do not
+ * unlink it from the list. Once the syscall restarts, we'll
+ * pick it up and wait on it again.
+ */
+ mutex_lock(&conn_src->lock);
+ reply_wait->interrupted = true;
+ schedule_delayed_work(&conn_src->work, 0);
+ mutex_unlock(&conn_src->lock);
+
+ return -ERESTARTSYS;
+ }
+
+ mutex_lock(&conn_src->lock);
+ reply_wait->waiting = false;
+ entry = reply_wait->queue_entry;
+ if (entry) {
+ ret = kdbus_queue_entry_install(entry,
+ &cmd_send->reply.return_flags,
+ true);
+ kdbus_pool_slice_publish(entry->slice, &cmd_send->reply.offset,
+ &cmd_send->reply.msg_size);
+ kdbus_queue_entry_free(entry);
+ }
+ kdbus_reply_unlink(reply_wait);
+ mutex_unlock(&conn_src->lock);
+
+ return ret;
+}
+
+static int kdbus_pin_dst(struct kdbus_bus *bus,
+ struct kdbus_staging *staging,
+ struct kdbus_name_entry **out_name,
+ struct kdbus_conn **out_dst)
+{
+ const struct kdbus_msg *msg = staging->msg;
+ struct kdbus_name_owner *owner = NULL;
+ struct kdbus_name_entry *name = NULL;
+ struct kdbus_conn *dst = NULL;
+ int ret;
+
+ lockdep_assert_held(&bus->name_registry->rwlock);
+
+ if (!staging->dst_name) {
+ dst = kdbus_bus_find_conn_by_id(bus, msg->dst_id);
+ if (!dst)
+ return -ENXIO;
+
+ if (!kdbus_conn_is_ordinary(dst)) {
+ ret = -ENXIO;
+ goto error;
+ }
+ } else {
+ name = kdbus_name_lookup_unlocked(bus->name_registry,
+ staging->dst_name);
+ if (name)
+ owner = kdbus_name_get_owner(name);
+ if (!owner)
+ return -ESRCH;
+
+ /*
+ * If both a name and a connection ID are given as destination
+ * of a message, check that the currently owning connection of
+ * the name matches the specified ID.
+ * This way, we allow userspace to send the message to a
+ * specific connection by ID only if the connection currently
+ * owns the given name.
+ */
+ if (msg->dst_id != KDBUS_DST_ID_NAME &&
+ msg->dst_id != owner->conn->id)
+ return -EREMCHG;
+
+ if ((msg->flags & KDBUS_MSG_NO_AUTO_START) &&
+ kdbus_conn_is_activator(owner->conn))
+ return -EADDRNOTAVAIL;
+
+ dst = kdbus_conn_ref(owner->conn);
+ }
+
+ *out_name = name;
+ *out_dst = dst;
+ return 0;
+
+error:
+ kdbus_conn_unref(dst);
+ return ret;
+}
+
+static int kdbus_conn_reply(struct kdbus_conn *src,
+ struct kdbus_staging *staging)
+{
+ const struct kdbus_msg *msg = staging->msg;
+ struct kdbus_name_entry *name = NULL;
+ struct kdbus_reply *reply, *wake = NULL;
+ struct kdbus_conn *dst = NULL;
+ struct kdbus_bus *bus = src->ep->bus;
+ int ret;
+
+ if (WARN_ON(msg->dst_id == KDBUS_DST_ID_BROADCAST) ||
+ WARN_ON(msg->flags & KDBUS_MSG_EXPECT_REPLY) ||
+ WARN_ON(msg->flags & KDBUS_MSG_SIGNAL))
+ return -EINVAL;
+
+ /* name-registry must be locked for lookup *and* collecting data */
+ down_read(&bus->name_registry->rwlock);
+
+ /* find and pin destination */
+
+ ret = kdbus_pin_dst(bus, staging, &name, &dst);
+ if (ret < 0)
+ goto exit;
+
+ mutex_lock(&dst->lock);
+ reply = kdbus_reply_find(src, dst, msg->cookie_reply);
+ if (reply) {
+ if (reply->sync)
+ wake = kdbus_reply_ref(reply);
+ else
+ kdbus_reply_unlink(reply);
+ }
+ mutex_unlock(&dst->lock);
+
+
+ /* send message */
+
+ kdbus_bus_eavesdrop(bus, src, staging);
+
+ if (wake)
+ ret = kdbus_conn_entry_sync_attach(dst, staging, wake);
+ else
+ ret = kdbus_conn_entry_insert(src, dst, staging, NULL, name);
+
+exit:
+ up_read(&bus->name_registry->rwlock);
+ kdbus_reply_unref(wake);
+ kdbus_conn_unref(dst);
+ return ret;
+}
+
+static struct kdbus_reply *kdbus_conn_call(struct kdbus_conn *src,
+ struct kdbus_staging *staging,
+ ktime_t exp)
+{
+ const struct kdbus_msg *msg = staging->msg;
+ struct kdbus_name_entry *name = NULL;
+ struct kdbus_reply *wait = NULL;
+ struct kdbus_conn *dst = NULL;
+ struct kdbus_bus *bus = src->ep->bus;
+ int ret;
+
+ if (WARN_ON(msg->dst_id == KDBUS_DST_ID_BROADCAST) ||
+ WARN_ON(msg->flags & KDBUS_MSG_SIGNAL) ||
+ WARN_ON(!(msg->flags & KDBUS_MSG_EXPECT_REPLY)))
+ return ERR_PTR(-EINVAL);
+
+ /* resume previous wait-context, if available */
+
+ mutex_lock(&src->lock);
+ wait = kdbus_reply_find(NULL, src, msg->cookie);
+ if (wait) {
+ if (wait->interrupted) {
+ kdbus_reply_ref(wait);
+ wait->interrupted = false;
+ } else {
+ wait = NULL;
+ }
+ }
+ mutex_unlock(&src->lock);
+
+ if (wait)
+ return wait;
+
+ if (ktime_compare(ktime_get(), exp) >= 0)
+ return ERR_PTR(-ETIMEDOUT);
+
+ /* name-registry must be locked for lookup *and* collecting data */
+ down_read(&bus->name_registry->rwlock);
+
+ /* find and pin destination */
+
+ ret = kdbus_pin_dst(bus, staging, &name, &dst);
+ if (ret < 0)
+ goto exit;
+
+ if (!kdbus_conn_policy_talk(src, current_cred(), dst)) {
+ ret = -EPERM;
+ goto exit;
+ }
+
+ wait = kdbus_reply_new(dst, src, msg, name, true);
+ if (IS_ERR(wait)) {
+ ret = PTR_ERR(wait);
+ wait = NULL;
+ goto exit;
+ }
+
+ /* send message */
+
+ kdbus_bus_eavesdrop(bus, src, staging);
+
+ ret = kdbus_conn_entry_insert(src, dst, staging, wait, name);
+ if (ret < 0)
+ goto exit;
+
+ ret = 0;
+
+exit:
+ up_read(&bus->name_registry->rwlock);
+ if (ret < 0) {
+ kdbus_reply_unref(wait);
+ wait = ERR_PTR(ret);
+ }
+ kdbus_conn_unref(dst);
+ return wait;
+}
+
+static int kdbus_conn_unicast(struct kdbus_conn *src,
+ struct kdbus_staging *staging)
+{
+ const struct kdbus_msg *msg = staging->msg;
+ struct kdbus_name_entry *name = NULL;
+ struct kdbus_reply *wait = NULL;
+ struct kdbus_conn *dst = NULL;
+ struct kdbus_bus *bus = src->ep->bus;
+ bool is_signal = (msg->flags & KDBUS_MSG_SIGNAL);
+ int ret = 0;
+
+ if (WARN_ON(msg->dst_id == KDBUS_DST_ID_BROADCAST) ||
+ WARN_ON(!(msg->flags & KDBUS_MSG_EXPECT_REPLY) &&
+ msg->cookie_reply != 0))
+ return -EINVAL;
+
+ /* name-registry must be locked for lookup *and* collecting data */
+ down_read(&bus->name_registry->rwlock);
+
+ /* find and pin destination */
+
+ ret = kdbus_pin_dst(bus, staging, &name, &dst);
+ if (ret < 0)
+ goto exit;
+
+ if (is_signal) {
+ /* like broadcasts we eavesdrop even if the msg is dropped */
+ kdbus_bus_eavesdrop(bus, src, staging);
+
+ /* drop silently if peer is not interested or not privileged */
+ if (!kdbus_match_db_match_msg(dst->match_db, src, staging) ||
+ !kdbus_conn_policy_talk(dst, NULL, src))
+ goto exit;
+ } else if (!kdbus_conn_policy_talk(src, current_cred(), dst)) {
+ ret = -EPERM;
+ goto exit;
+ } else if (msg->flags & KDBUS_MSG_EXPECT_REPLY) {
+ wait = kdbus_reply_new(dst, src, msg, name, false);
+ if (IS_ERR(wait)) {
+ ret = PTR_ERR(wait);
+ wait = NULL;
+ goto exit;
+ }
+ }
+
+ /* send message */
+
+ if (!is_signal)
+ kdbus_bus_eavesdrop(bus, src, staging);
+
+ ret = kdbus_conn_entry_insert(src, dst, staging, wait, name);
+ if (ret < 0 && !is_signal)
+ goto exit;
+
+ /* signals are treated like broadcasts, recv-errors are ignored */
+ ret = 0;
+
+exit:
+ up_read(&bus->name_registry->rwlock);
+ kdbus_reply_unref(wait);
+ kdbus_conn_unref(dst);
+ return ret;
+}
+
+/**
+ * kdbus_conn_move_messages() - move messages from one connection to another
+ * @conn_dst: Connection to copy to
+ * @conn_src: Connection to copy from
+ * @name_id: Filter for the sequence number of the registered
+ * name, 0 means no filtering.
+ *
+ * Move all messages from one connection to another. This is used when
+ * an implementer connection is taking over/giving back a well-known name
+ * from/to an activator connection.
+ */
+void kdbus_conn_move_messages(struct kdbus_conn *conn_dst,
+ struct kdbus_conn *conn_src,
+ u64 name_id)
+{
+ struct kdbus_queue_entry *e, *e_tmp;
+ struct kdbus_reply *r, *r_tmp;
+ struct kdbus_bus *bus;
+ struct kdbus_conn *c;
+ LIST_HEAD(msg_list);
+ int i, ret = 0;
+
+ if (WARN_ON(conn_src == conn_dst))
+ return;
+
+ bus = conn_src->ep->bus;
+
+ /* lock order: domain -> bus -> ep -> names -> conn */
+ down_read(&bus->conn_rwlock);
+ hash_for_each(bus->conn_hash, i, c, hentry) {
+ if (c == conn_src || c == conn_dst)
+ continue;
+
+ mutex_lock(&c->lock);
+ list_for_each_entry_safe(r, r_tmp, &c->reply_list, entry) {
+ if (r->reply_src != conn_src)
+ continue;
+
+ /* filter messages for a specific name */
+ if (name_id > 0 && r->name_id != name_id)
+ continue;
+
+ kdbus_conn_unref(r->reply_src);
+ r->reply_src = kdbus_conn_ref(conn_dst);
+ }
+ mutex_unlock(&c->lock);
+ }
+ up_read(&bus->conn_rwlock);
+
+ kdbus_conn_lock2(conn_src, conn_dst);
+ list_for_each_entry_safe(e, e_tmp, &conn_src->queue.msg_list, entry) {
+ /* filter messages for a specific name */
+ if (name_id > 0 && e->dst_name_id != name_id)
+ continue;
+
+ if (!(conn_dst->flags & KDBUS_HELLO_ACCEPT_FD) &&
+ e->gaps && e->gaps->n_fds > 0) {
+ kdbus_conn_lost_message(conn_dst);
+ kdbus_queue_entry_free(e);
+ continue;
+ }
+
+ ret = kdbus_queue_entry_move(e, conn_dst);
+ if (ret < 0) {
+ kdbus_conn_lost_message(conn_dst);
+ kdbus_queue_entry_free(e);
+ continue;
+ }
+ }
+ kdbus_conn_unlock2(conn_src, conn_dst);
+
+ /* wake up poll() */
+ wake_up_interruptible(&conn_dst->wait);
+}
+
+/* query the policy-database for all names of @whom */
+static bool kdbus_conn_policy_query_all(struct kdbus_conn *conn,
+ const struct cred *conn_creds,
+ struct kdbus_policy_db *db,
+ struct kdbus_conn *whom,
+ unsigned int access)
+{
+ struct kdbus_name_owner *owner;
+ bool pass = false;
+ int res;
+
+ lockdep_assert_held(&conn->ep->bus->name_registry->rwlock);
+
+ down_read(&db->entries_rwlock);
+ mutex_lock(&whom->lock);
+
+ list_for_each_entry(owner, &whom->names_list, conn_entry) {
+ if (owner->flags & KDBUS_NAME_IN_QUEUE)
+ continue;
+
+ res = kdbus_policy_query_unlocked(db,
+ conn_creds ? : conn->cred,
+ owner->name->name,
+ kdbus_strhash(owner->name->name));
+ if (res >= (int)access) {
+ pass = true;
+ break;
+ }
+ }
+
+ mutex_unlock(&whom->lock);
+ up_read(&db->entries_rwlock);
+
+ return pass;
+}
+
+/**
+ * kdbus_conn_policy_own_name() - verify a connection can own the given name
+ * @conn: Connection
+ * @conn_creds: Credentials of @conn to use for policy check
+ * @name: Name
+ *
+ * This verifies that @conn is allowed to acquire the well-known name @name.
+ *
+ * Return: true if allowed, false if not.
+ */
+bool kdbus_conn_policy_own_name(struct kdbus_conn *conn,
+ const struct cred *conn_creds,
+ const char *name)
+{
+ unsigned int hash = kdbus_strhash(name);
+ int res;
+
+#ifdef DISABLE_KDBUS_POLICY
+ return true;
+#endif
+
+ if (!conn_creds)
+ conn_creds = conn->cred;
+
+ if (conn->ep->user) {
+ res = kdbus_policy_query(&conn->ep->policy_db, conn_creds,
+ name, hash);
+ if (res < KDBUS_POLICY_OWN)
+ return false;
+ }
+
+ if (conn->owner)
+ return true;
+
+ res = kdbus_policy_query(&conn->ep->bus->policy_db, conn_creds,
+ name, hash);
+ return res >= KDBUS_POLICY_OWN;
+}
+
+/**
+ * kdbus_conn_policy_talk() - verify a connection can talk to a given peer
+ * @conn: Connection that tries to talk
+ * @conn_creds: Credentials of @conn to use for policy check
+ * @to: Connection that is talked to
+ *
+ * This verifies that @conn is allowed to talk to @to.
+ *
+ * Return: true if allowed, false if not.
+ */
+bool kdbus_conn_policy_talk(struct kdbus_conn *conn,
+ const struct cred *conn_creds,
+ struct kdbus_conn *to)
+{
+
+#ifdef DISABLE_KDBUS_POLICY
+ return true;
+#endif
+
+ if (!conn_creds)
+ conn_creds = conn->cred;
+
+ if (conn->ep->user &&
+ !kdbus_conn_policy_query_all(conn, conn_creds, &conn->ep->policy_db,
+ to, KDBUS_POLICY_TALK))
+ return false;
+
+ if (conn->owner)
+ return true;
+ if (uid_eq(conn_creds->euid, to->cred->uid))
+ return true;
+
+ return kdbus_conn_policy_query_all(conn, conn_creds,
+ &conn->ep->bus->policy_db, to,
+ KDBUS_POLICY_TALK);
+}
+
+/**
+ * kdbus_conn_policy_see_name_unlocked() - verify a connection can see a given
+ * name
+ * @conn: Connection
+ * @conn_creds: Credentials of @conn to use for policy check
+ * @name: Name
+ *
+ * This verifies that @conn is allowed to see the well-known name @name. Caller
+ * must hold policy-lock.
+ *
+ * Return: true if allowed, false if not.
+ */
+bool kdbus_conn_policy_see_name_unlocked(struct kdbus_conn *conn,
+ const struct cred *conn_creds,
+ const char *name)
+{
+ int res;
+
+#ifdef DISABLE_KDBUS_POLICY
+ return true;
+#endif
+
+ /*
+ * By default, all names are visible on a bus. SEE policies can only be
+ * installed on custom endpoints, where by default no name is visible.
+ */
+ if (!conn->ep->user)
+ return true;
+
+ res = kdbus_policy_query_unlocked(&conn->ep->policy_db,
+ conn_creds ? : conn->cred,
+ name, kdbus_strhash(name));
+ return res >= KDBUS_POLICY_SEE;
+}
+
+static bool kdbus_conn_policy_see_name(struct kdbus_conn *conn,
+ const struct cred *conn_creds,
+ const char *name)
+{
+ bool res;
+
+ down_read(&conn->ep->policy_db.entries_rwlock);
+ res = kdbus_conn_policy_see_name_unlocked(conn, conn_creds, name);
+ up_read(&conn->ep->policy_db.entries_rwlock);
+
+ return res;
+}
+
+static bool kdbus_conn_policy_see(struct kdbus_conn *conn,
+ const struct cred *conn_creds,
+ struct kdbus_conn *whom)
+{
+
+#ifdef DISABLE_KDBUS_POLICY
+ return true;
+#endif
+
+ /*
+ * By default, all names are visible on a bus, so a connection can
+ * always see other connections. SEE policies can only be installed on
+ * custom endpoints, where by default no name is visible and we hide
+ * peers from each other, unless you see at least _one_ name of the
+ * peer.
+ */
+ return !conn->ep->user ||
+ kdbus_conn_policy_query_all(conn, conn_creds,
+ &conn->ep->policy_db, whom,
+ KDBUS_POLICY_SEE);
+}
+
+/**
+ * kdbus_conn_policy_see_notification() - verify a connection is allowed to
+ * receive a given kernel notification
+ * @conn: Connection
+ * @conn_creds: Credentials of @conn to use for policy check
+ * @msg: Notification message
+ *
+ * This checks whether @conn is allowed to see the kernel notification.
+ *
+ * Return: true if allowed, false if not.
+ */
+bool kdbus_conn_policy_see_notification(struct kdbus_conn *conn,
+ const struct cred *conn_creds,
+ const struct kdbus_msg *msg)
+{
+ /*
+ * Depending on the notification type, broadcasted kernel notifications
+ * have to be filtered:
+ *
+ * KDBUS_ITEM_NAME_{ADD,REMOVE,CHANGE}: This notification is forwarded
+ * to a peer if, and only if, that peer can see the name this
+ * notification is for.
+ *
+ * KDBUS_ITEM_ID_{ADD,REMOVE}: Notifications for ID changes are
+ * broadcast to everyone, to allow tracking peers.
+ */
+
+ switch (msg->items[0].type) {
+ case KDBUS_ITEM_NAME_ADD:
+ case KDBUS_ITEM_NAME_REMOVE:
+ case KDBUS_ITEM_NAME_CHANGE:
+ return kdbus_conn_policy_see_name(conn, conn_creds,
+ msg->items[0].name_change.name);
+
+ case KDBUS_ITEM_ID_ADD:
+ case KDBUS_ITEM_ID_REMOVE:
+ return true;
+
+ default:
+ WARN(1, "Invalid type for notification broadcast: %llu\n",
+ (unsigned long long)msg->items[0].type);
+ return false;
+ }
+}
+
+/**
+ * kdbus_cmd_hello() - handle KDBUS_CMD_HELLO
+ * @ep: Endpoint to operate on
+ * @file: File this connection is opened on
+ * @argp: Command payload
+ *
+ * Return: NULL or newly created connection on success, ERR_PTR on failure.
+ */
+struct kdbus_conn *kdbus_cmd_hello(struct kdbus_ep *ep, struct file *file,
+ void __user *argp)
+{
+ struct kdbus_cmd_hello *cmd;
+ struct kdbus_conn *c = NULL;
+ const char *item_name;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_NAME },
+ { .type = KDBUS_ITEM_CREDS },
+ { .type = KDBUS_ITEM_PIDS },
+ { .type = KDBUS_ITEM_SECLABEL },
+ { .type = KDBUS_ITEM_CONN_DESCRIPTION },
+ { .type = KDBUS_ITEM_POLICY_ACCESS, .multiple = true },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_HELLO_ACCEPT_FD |
+ KDBUS_HELLO_ACTIVATOR |
+ KDBUS_HELLO_POLICY_HOLDER |
+ KDBUS_HELLO_MONITOR,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0)
+ return NULL;
+
+ item_name = argv[1].item ? argv[1].item->str : NULL;
+
+ c = kdbus_conn_new(ep, file, cmd, item_name,
+ argv[2].item ? &argv[2].item->creds : NULL,
+ argv[3].item ? &argv[3].item->pids : NULL,
+ argv[4].item ? argv[4].item->str : NULL,
+ argv[5].item ? argv[5].item->str : NULL);
+ if (IS_ERR(c)) {
+ ret = PTR_ERR(c);
+ c = NULL;
+ goto exit;
+ }
+
+ ret = kdbus_conn_connect(c, item_name);
+ if (ret < 0)
+ goto exit;
+
+ if (kdbus_conn_is_activator(c) || kdbus_conn_is_policy_holder(c)) {
+ ret = kdbus_conn_acquire(c);
+ if (ret < 0)
+ goto exit;
+
+ ret = kdbus_policy_set(&c->ep->bus->policy_db, args.items,
+ args.items_size, 1,
+ kdbus_conn_is_policy_holder(c), c);
+ kdbus_conn_release(c);
+ if (ret < 0)
+ goto exit;
+ }
+
+ if (copy_to_user(argp, cmd, sizeof(*cmd)))
+ ret = -EFAULT;
+
+exit:
+ ret = kdbus_args_clear(&args, ret);
+ if (ret < 0) {
+ if (c) {
+ kdbus_conn_disconnect(c, false);
+ kdbus_conn_unref(c);
+ }
+ return ERR_PTR(ret);
+ }
+ return c;
+}
+
+/**
+ * kdbus_cmd_byebye_unlocked() - handle KDBUS_CMD_BYEBYE
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * The caller must not hold any active reference to @conn or this will deadlock.
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_byebye_unlocked(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_cmd *cmd;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ if (!kdbus_conn_is_ordinary(conn))
+ return -EOPNOTSUPP;
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ ret = kdbus_conn_disconnect(conn, true);
+ return kdbus_args_clear(&args, ret);
+}
+
+/**
+ * kdbus_cmd_conn_info() - handle KDBUS_CMD_CONN_INFO
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_conn_info(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_meta_conn *conn_meta = NULL;
+ struct kdbus_pool_slice *slice = NULL;
+ struct kdbus_name_entry *entry = NULL;
+ struct kdbus_name_owner *owner = NULL;
+ struct kdbus_conn *owner_conn = NULL;
+ struct kdbus_item *meta_items = NULL;
+ struct kdbus_info info = {};
+ struct kdbus_cmd_info *cmd;
+ struct kdbus_bus *bus = conn->ep->bus;
+ struct kvec kvec[3];
+ size_t meta_size, cnt = 0;
+ const char *name;
+ u64 attach_flags, size = 0;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_NAME },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ /* registry must be held throughout lookup *and* collecting data */
+ down_read(&bus->name_registry->rwlock);
+
+ ret = kdbus_sanitize_attach_flags(cmd->attach_flags, &attach_flags);
+ if (ret < 0)
+ goto exit;
+
+ name = argv[1].item ? argv[1].item->str : NULL;
+
+ if (name) {
+ entry = kdbus_name_lookup_unlocked(bus->name_registry, name);
+ if (entry)
+ owner = kdbus_name_get_owner(entry);
+ if (!owner ||
+ !kdbus_conn_policy_see_name(conn, current_cred(), name) ||
+ (cmd->id != 0 && owner->conn->id != cmd->id)) {
+ /* pretend a name doesn't exist if you cannot see it */
+ ret = -ESRCH;
+ goto exit;
+ }
+
+ owner_conn = kdbus_conn_ref(owner->conn);
+ } else if (cmd->id > 0) {
+ owner_conn = kdbus_bus_find_conn_by_id(bus, cmd->id);
+ if (!owner_conn || !kdbus_conn_policy_see(conn, current_cred(),
+ owner_conn)) {
+ /* pretend an id doesn't exist if you cannot see it */
+ ret = -ENXIO;
+ goto exit;
+ }
+ } else {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ attach_flags &= atomic64_read(&owner_conn->attach_flags_send);
+
+ conn_meta = kdbus_meta_conn_new();
+ if (IS_ERR(conn_meta)) {
+ ret = PTR_ERR(conn_meta);
+ conn_meta = NULL;
+ goto exit;
+ }
+
+ ret = kdbus_meta_conn_collect(conn_meta, owner_conn, 0, attach_flags);
+ if (ret < 0)
+ goto exit;
+
+ ret = kdbus_meta_emit(owner_conn->meta_proc, owner_conn->meta_fake,
+ conn_meta, conn, attach_flags,
+ &meta_items, &meta_size);
+ if (ret < 0)
+ goto exit;
+
+ info.id = owner_conn->id;
+ info.flags = owner_conn->flags;
+
+ kdbus_kvec_set(&kvec[cnt++], &info, sizeof(info), &size);
+ if (meta_size > 0) {
+ kdbus_kvec_set(&kvec[cnt++], meta_items, meta_size, &size);
+ cnt += !!kdbus_kvec_pad(&kvec[cnt], &size);
+ }
+
+ info.size = size;
+
+ slice = kdbus_pool_slice_alloc(conn->pool, size, false);
+ if (IS_ERR(slice)) {
+ ret = PTR_ERR(slice);
+ slice = NULL;
+ goto exit;
+ }
+
+ ret = kdbus_pool_slice_copy_kvec(slice, 0, kvec, cnt, size);
+ if (ret < 0)
+ goto exit;
+
+ kdbus_pool_slice_publish(slice, &cmd->offset, &cmd->info_size);
+
+ if (kdbus_member_set_user(&cmd->offset, argp, typeof(*cmd), offset) ||
+ kdbus_member_set_user(&cmd->info_size, argp,
+ typeof(*cmd), info_size)) {
+ ret = -EFAULT;
+ goto exit;
+ }
+
+ ret = 0;
+
+exit:
+ up_read(&bus->name_registry->rwlock);
+ kdbus_pool_slice_release(slice);
+ kfree(meta_items);
+ kdbus_meta_conn_unref(conn_meta);
+ kdbus_conn_unref(owner_conn);
+ return kdbus_args_clear(&args, ret);
+}
+
+/**
+ * kdbus_cmd_update() - handle KDBUS_CMD_UPDATE
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_update(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_item *item_policy;
+ u64 *item_attach_send = NULL;
+ u64 *item_attach_recv = NULL;
+ struct kdbus_cmd *cmd;
+ u64 attach_send;
+ u64 attach_recv;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_ATTACH_FLAGS_SEND },
+ { .type = KDBUS_ITEM_ATTACH_FLAGS_RECV },
+ { .type = KDBUS_ITEM_NAME, .multiple = true },
+ { .type = KDBUS_ITEM_POLICY_ACCESS, .multiple = true },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ item_attach_send = argv[1].item ? &argv[1].item->data64[0] : NULL;
+ item_attach_recv = argv[2].item ? &argv[2].item->data64[0] : NULL;
+ item_policy = argv[3].item ? : argv[4].item;
+
+ if (item_attach_send) {
+ if (!kdbus_conn_is_ordinary(conn) &&
+ !kdbus_conn_is_monitor(conn)) {
+ ret = -EOPNOTSUPP;
+ goto exit;
+ }
+
+ ret = kdbus_sanitize_attach_flags(*item_attach_send,
+ &attach_send);
+ if (ret < 0)
+ goto exit;
+ }
+
+ if (item_attach_recv) {
+ if (!kdbus_conn_is_ordinary(conn) &&
+ !kdbus_conn_is_monitor(conn) &&
+ !kdbus_conn_is_activator(conn)) {
+ ret = -EOPNOTSUPP;
+ goto exit;
+ }
+
+ ret = kdbus_sanitize_attach_flags(*item_attach_recv,
+ &attach_recv);
+ if (ret < 0)
+ goto exit;
+ }
+
+ if (item_policy && !kdbus_conn_is_policy_holder(conn)) {
+ ret = -EOPNOTSUPP;
+ goto exit;
+ }
+
+ /* now that we verified the input, update the connection */
+
+ if (item_policy) {
+ ret = kdbus_policy_set(&conn->ep->bus->policy_db, cmd->items,
+ KDBUS_ITEMS_SIZE(cmd, items),
+ 1, true, conn);
+ if (ret < 0)
+ goto exit;
+ }
+
+ if (item_attach_send)
+ atomic64_set(&conn->attach_flags_send, attach_send);
+
+ if (item_attach_recv)
+ atomic64_set(&conn->attach_flags_recv, attach_recv);
+
+exit:
+ return kdbus_args_clear(&args, ret);
+}
+
+/**
+ * kdbus_cmd_send() - handle KDBUS_CMD_SEND
+ * @conn: connection to operate on
+ * @f: file this command was called on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_send(struct kdbus_conn *conn, struct file *f, void __user *argp)
+{
+ struct kdbus_cmd_send *cmd;
+ struct kdbus_staging *staging = NULL;
+ struct kdbus_msg *msg = NULL;
+ struct file *cancel_fd = NULL;
+ int ret, ret2;
+
+ /* command arguments */
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_CANCEL_FD },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_SEND_SYNC_REPLY,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ /* message arguments */
+ struct kdbus_arg msg_argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_PAYLOAD_VEC, .multiple = true },
+ { .type = KDBUS_ITEM_PAYLOAD_MEMFD, .multiple = true },
+ { .type = KDBUS_ITEM_FDS },
+ { .type = KDBUS_ITEM_BLOOM_FILTER },
+ { .type = KDBUS_ITEM_DST_NAME },
+ };
+ struct kdbus_args msg_args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_MSG_EXPECT_REPLY |
+ KDBUS_MSG_NO_AUTO_START |
+ KDBUS_MSG_SIGNAL,
+ .argv = msg_argv,
+ .argc = ARRAY_SIZE(msg_argv),
+ };
+
+ if (!kdbus_conn_is_ordinary(conn))
+ return -EOPNOTSUPP;
+
+ /* make sure to parse both, @cmd and @msg on negotiation */
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret < 0)
+ goto exit;
+ else if (ret > 0 && !cmd->msg_address) /* negotiation without msg */
+ goto exit;
+
+ ret2 = kdbus_args_parse_msg(&msg_args, KDBUS_PTR(cmd->msg_address),
+ &msg);
+ if (ret2 < 0) { /* cannot parse message */
+ ret = ret2;
+ goto exit;
+ } else if (ret2 > 0 && !ret) { /* msg-negot implies cmd-negot */
+ ret = -EINVAL;
+ goto exit;
+ } else if (ret > 0) { /* negotiation */
+ goto exit;
+ }
+
+ /* here we parsed both, @cmd and @msg, and neither wants negotiation */
+
+ cmd->reply.return_flags = 0;
+ kdbus_pool_publish_empty(conn->pool, &cmd->reply.offset,
+ &cmd->reply.msg_size);
+
+ if (argv[1].item) {
+ cancel_fd = fget(argv[1].item->fds[0]);
+ if (!cancel_fd) {
+ ret = -EBADF;
+ goto exit;
+ }
+
+ if (!cancel_fd->f_op->poll) {
+ ret = -EINVAL;
+ goto exit;
+ }
+ }
+
+ /* patch-in the source of this message */
+ if (msg->src_id > 0 && msg->src_id != conn->id) {
+ ret = -EINVAL;
+ goto exit;
+ }
+ msg->src_id = conn->id;
+
+ staging = kdbus_staging_new_user(conn->ep->bus, cmd, msg);
+ if (IS_ERR(staging)) {
+ ret = PTR_ERR(staging);
+ staging = NULL;
+ goto exit;
+ }
+
+ if (msg->dst_id == KDBUS_DST_ID_BROADCAST) {
+ down_read(&conn->ep->bus->name_registry->rwlock);
+ kdbus_bus_broadcast(conn->ep->bus, conn, staging);
+ up_read(&conn->ep->bus->name_registry->rwlock);
+ } else if (cmd->flags & KDBUS_SEND_SYNC_REPLY) {
+ struct kdbus_reply *r;
+ ktime_t exp;
+
+ exp = ns_to_ktime(msg->timeout_ns);
+ r = kdbus_conn_call(conn, staging, exp);
+ if (IS_ERR(r)) {
+ ret = PTR_ERR(r);
+ goto exit;
+ }
+
+ ret = kdbus_conn_wait_reply(conn, cmd, f, cancel_fd, r, exp);
+ kdbus_reply_unref(r);
+ if (ret < 0)
+ goto exit;
+ } else if ((msg->flags & KDBUS_MSG_EXPECT_REPLY) ||
+ msg->cookie_reply == 0) {
+ ret = kdbus_conn_unicast(conn, staging);
+ if (ret < 0)
+ goto exit;
+ } else {
+ ret = kdbus_conn_reply(conn, staging);
+ if (ret < 0)
+ goto exit;
+ }
+
+ if (kdbus_member_set_user(&cmd->reply, argp, typeof(*cmd), reply))
+ ret = -EFAULT;
+
+exit:
+ if (cancel_fd)
+ fput(cancel_fd);
+ kdbus_staging_free(staging);
+ ret = kdbus_args_clear(&msg_args, ret);
+ return kdbus_args_clear(&args, ret);
+}
+
+/**
+ * kdbus_cmd_recv() - handle KDBUS_CMD_RECV
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_recv(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_queue_entry *entry;
+ struct kdbus_cmd_recv *cmd;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_RECV_PEEK |
+ KDBUS_RECV_DROP |
+ KDBUS_RECV_USE_PRIORITY,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ if (!kdbus_conn_is_ordinary(conn) &&
+ !kdbus_conn_is_monitor(conn) &&
+ !kdbus_conn_is_activator(conn))
+ return -EOPNOTSUPP;
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ cmd->dropped_msgs = 0;
+ cmd->msg.return_flags = 0;
+ kdbus_pool_publish_empty(conn->pool, &cmd->msg.offset,
+ &cmd->msg.msg_size);
+
+ /* DROP+priority is not realiably, so prevent it */
+ if ((cmd->flags & KDBUS_RECV_DROP) &&
+ (cmd->flags & KDBUS_RECV_USE_PRIORITY)) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ mutex_lock(&conn->lock);
+
+ entry = kdbus_queue_peek(&conn->queue, cmd->priority,
+ cmd->flags & KDBUS_RECV_USE_PRIORITY);
+ if (!entry) {
+ mutex_unlock(&conn->lock);
+ ret = -EAGAIN;
+ } else if (cmd->flags & KDBUS_RECV_DROP) {
+ struct kdbus_reply *reply = kdbus_reply_ref(entry->reply);
+
+ kdbus_queue_entry_free(entry);
+
+ mutex_unlock(&conn->lock);
+
+ if (reply) {
+ mutex_lock(&reply->reply_dst->lock);
+ if (!list_empty(&reply->entry)) {
+ kdbus_reply_unlink(reply);
+ if (reply->sync)
+ kdbus_sync_reply_wakeup(reply, -EPIPE);
+ else
+ kdbus_notify_reply_dead(conn->ep->bus,
+ reply->reply_dst->id,
+ reply->cookie);
+ }
+ mutex_unlock(&reply->reply_dst->lock);
+ kdbus_notify_flush(conn->ep->bus);
+ }
+
+ kdbus_reply_unref(reply);
+ } else {
+ bool install_fds;
+
+ /*
+ * PEEK just returns the location of the next message. Do not
+ * install FDs nor memfds nor anything else. The only
+ * information of interest should be the message header and
+ * metadata. Any FD numbers in the payload is undefined for
+ * PEEK'ed messages.
+ * Also make sure to never install fds into a connection that
+ * has refused to receive any. Ordinary connections will not get
+ * messages with FDs queued (the receiver will get -ECOMM), but
+ * eavesdroppers might.
+ */
+ install_fds = (conn->flags & KDBUS_HELLO_ACCEPT_FD) &&
+ !(cmd->flags & KDBUS_RECV_PEEK);
+
+ ret = kdbus_queue_entry_install(entry,
+ &cmd->msg.return_flags,
+ install_fds);
+ if (ret < 0) {
+ mutex_unlock(&conn->lock);
+ goto exit;
+ }
+
+ kdbus_pool_slice_publish(entry->slice, &cmd->msg.offset,
+ &cmd->msg.msg_size);
+
+ if (!(cmd->flags & KDBUS_RECV_PEEK))
+ kdbus_queue_entry_free(entry);
+
+ mutex_unlock(&conn->lock);
+ }
+
+ cmd->dropped_msgs = atomic_xchg(&conn->lost_count, 0);
+ if (cmd->dropped_msgs > 0)
+ cmd->return_flags |= KDBUS_RECV_RETURN_DROPPED_MSGS;
+
+ if (kdbus_member_set_user(&cmd->msg, argp, typeof(*cmd), msg) ||
+ kdbus_member_set_user(&cmd->dropped_msgs, argp, typeof(*cmd),
+ dropped_msgs))
+ ret = -EFAULT;
+
+exit:
+ return kdbus_args_clear(&args, ret);
+}
+
+/**
+ * kdbus_cmd_free() - handle KDBUS_CMD_FREE
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_free(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_cmd_free *cmd;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ if (!kdbus_conn_is_ordinary(conn) &&
+ !kdbus_conn_is_monitor(conn) &&
+ !kdbus_conn_is_activator(conn))
+ return -EOPNOTSUPP;
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ ret = kdbus_pool_release_offset(conn->pool, cmd->offset);
+
+ return kdbus_args_clear(&args, ret);
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_CONNECTION_H
+#define __KDBUS_CONNECTION_H
+
+#include <linux/atomic.h>
+#include <linux/kref.h>
+#include <linux/lockdep.h>
+#include <linux/path.h>
+
+#include "limits.h"
+#include "metadata.h"
+#include "pool.h"
+#include "queue.h"
+#include "util.h"
+
+#define KDBUS_HELLO_SPECIAL_CONN (KDBUS_HELLO_ACTIVATOR | \
+ KDBUS_HELLO_POLICY_HOLDER | \
+ KDBUS_HELLO_MONITOR)
+
+struct kdbus_name_entry;
+struct kdbus_quota;
+struct kdbus_staging;
+
+/**
+ * struct kdbus_conn - connection to a bus
+ * @kref: Reference count
+ * @active: Active references to the connection
+ * @id: Connection ID
+ * @flags: KDBUS_HELLO_* flags
+ * @attach_flags_send: KDBUS_ATTACH_* flags for sending
+ * @attach_flags_recv: KDBUS_ATTACH_* flags for receiving
+ * @description: Human-readable connection description, used for
+ * debugging. This field is only set when the
+ * connection is created.
+ * @ep: The endpoint this connection belongs to
+ * @lock: Connection data lock
+ * @hentry: Entry in ID <-> connection map
+ * @ep_entry: Entry in endpoint
+ * @monitor_entry: Entry in monitor, if the connection is a monitor
+ * @reply_list: List of connections this connection should
+ * reply to
+ * @work: Delayed work to handle timeouts
+ * activator for
+ * @match_db: Subscription filter to broadcast messages
+ * @meta_proc: Process metadata of connection creator, or NULL
+ * @meta_fake: Faked metadata, or NULL
+ * @pool: The user's buffer to receive messages
+ * @user: Owner of the connection
+ * @cred: The credentials of the connection at creation time
+ * @pid: Pid at creation time
+ * @root_path: Root path at creation time
+ * @request_count: Number of pending requests issued by this
+ * connection that are waiting for replies from
+ * other peers
+ * @lost_count: Number of lost broadcast messages
+ * @wait: Wake up this endpoint
+ * @queue: The message queue associated with this connection
+ * @quota: Array of per-user quota indexed by user->id
+ * @n_quota: Number of elements in quota array
+ * @names_list: List of well-known names
+ * @name_count: Number of owned well-known names
+ * @privileged: Whether this connection is privileged on the domain
+ * @owner: Owned by the same user as the bus owner
+ */
+struct kdbus_conn {
+ struct kref kref;
+ atomic_t active;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+ u64 id;
+ u64 flags;
+ atomic64_t attach_flags_send;
+ atomic64_t attach_flags_recv;
+ const char *description;
+ struct kdbus_ep *ep;
+ struct mutex lock;
+ struct hlist_node hentry;
+ struct list_head ep_entry;
+ struct list_head monitor_entry;
+ struct list_head reply_list;
+ struct delayed_work work;
+ struct kdbus_match_db *match_db;
+ struct kdbus_meta_proc *meta_proc;
+ struct kdbus_meta_fake *meta_fake;
+ struct kdbus_pool *pool;
+ struct kdbus_user *user;
+ const struct cred *cred;
+ struct pid *pid;
+ struct path root_path;
+ atomic_t request_count;
+ atomic_t lost_count;
+ wait_queue_head_t wait;
+ struct kdbus_queue queue;
+
+ struct kdbus_quota *quota;
+ unsigned int n_quota;
+
+ /* protected by registry->rwlock */
+ struct list_head names_list;
+ unsigned int name_count;
+
+ bool privileged:1;
+ bool owner:1;
+};
+
+struct kdbus_conn *kdbus_conn_ref(struct kdbus_conn *conn);
+struct kdbus_conn *kdbus_conn_unref(struct kdbus_conn *conn);
+bool kdbus_conn_active(const struct kdbus_conn *conn);
+int kdbus_conn_acquire(struct kdbus_conn *conn);
+void kdbus_conn_release(struct kdbus_conn *conn);
+int kdbus_conn_disconnect(struct kdbus_conn *conn, bool ensure_queue_empty);
+bool kdbus_conn_has_name(struct kdbus_conn *conn, const char *name);
+int kdbus_conn_quota_inc(struct kdbus_conn *c, struct kdbus_user *u,
+ size_t memory, size_t fds);
+void kdbus_conn_quota_dec(struct kdbus_conn *c, struct kdbus_user *u,
+ size_t memory, size_t fds);
+void kdbus_conn_lost_message(struct kdbus_conn *c);
+int kdbus_conn_entry_insert(struct kdbus_conn *conn_src,
+ struct kdbus_conn *conn_dst,
+ struct kdbus_staging *staging,
+ struct kdbus_reply *reply,
+ const struct kdbus_name_entry *name);
+void kdbus_conn_move_messages(struct kdbus_conn *conn_dst,
+ struct kdbus_conn *conn_src,
+ u64 name_id);
+
+/* policy */
+bool kdbus_conn_policy_own_name(struct kdbus_conn *conn,
+ const struct cred *conn_creds,
+ const char *name);
+bool kdbus_conn_policy_talk(struct kdbus_conn *conn,
+ const struct cred *conn_creds,
+ struct kdbus_conn *to);
+bool kdbus_conn_policy_see_name_unlocked(struct kdbus_conn *conn,
+ const struct cred *curr_creds,
+ const char *name);
+bool kdbus_conn_policy_see_notification(struct kdbus_conn *conn,
+ const struct cred *curr_creds,
+ const struct kdbus_msg *msg);
+
+/* command dispatcher */
+struct kdbus_conn *kdbus_cmd_hello(struct kdbus_ep *ep, struct file *file,
+ void __user *argp);
+int kdbus_cmd_byebye_unlocked(struct kdbus_conn *conn, void __user *argp);
+int kdbus_cmd_conn_info(struct kdbus_conn *conn, void __user *argp);
+int kdbus_cmd_update(struct kdbus_conn *conn, void __user *argp);
+int kdbus_cmd_send(struct kdbus_conn *conn, struct file *f, void __user *argp);
+int kdbus_cmd_recv(struct kdbus_conn *conn, void __user *argp);
+int kdbus_cmd_free(struct kdbus_conn *conn, void __user *argp);
+
+/**
+ * kdbus_conn_is_ordinary() - Check if connection is ordinary
+ * @conn: The connection to check
+ *
+ * Return: Non-zero if the connection is an ordinary connection
+ */
+static inline int kdbus_conn_is_ordinary(const struct kdbus_conn *conn)
+{
+ return !(conn->flags & KDBUS_HELLO_SPECIAL_CONN);
+}
+
+/**
+ * kdbus_conn_is_activator() - Check if connection is an activator
+ * @conn: The connection to check
+ *
+ * Return: Non-zero if the connection is an activator
+ */
+static inline int kdbus_conn_is_activator(const struct kdbus_conn *conn)
+{
+ return conn->flags & KDBUS_HELLO_ACTIVATOR;
+}
+
+/**
+ * kdbus_conn_is_policy_holder() - Check if connection is a policy holder
+ * @conn: The connection to check
+ *
+ * Return: Non-zero if the connection is a policy holder
+ */
+static inline int kdbus_conn_is_policy_holder(const struct kdbus_conn *conn)
+{
+ return conn->flags & KDBUS_HELLO_POLICY_HOLDER;
+}
+
+/**
+ * kdbus_conn_is_monitor() - Check if connection is a monitor
+ * @conn: The connection to check
+ *
+ * Return: Non-zero if the connection is a monitor
+ */
+static inline int kdbus_conn_is_monitor(const struct kdbus_conn *conn)
+{
+ return conn->flags & KDBUS_HELLO_MONITOR;
+}
+
+/**
+ * kdbus_conn_lock2() - Lock two connections
+ * @a: connection A to lock or NULL
+ * @b: connection B to lock or NULL
+ *
+ * Lock two connections at once. As we need to have a stable locking order, we
+ * always lock the connection with lower memory address first.
+ */
+static inline void kdbus_conn_lock2(struct kdbus_conn *a, struct kdbus_conn *b)
+{
+ if (a < b) {
+ if (a)
+ mutex_lock(&a->lock);
+ if (b && b != a)
+ mutex_lock_nested(&b->lock, !!a);
+ } else {
+ if (b)
+ mutex_lock(&b->lock);
+ if (a && a != b)
+ mutex_lock_nested(&a->lock, !!b);
+ }
+}
+
+/**
+ * kdbus_conn_unlock2() - Unlock two connections
+ * @a: connection A to unlock or NULL
+ * @b: connection B to unlock or NULL
+ *
+ * Unlock two connections at once. See kdbus_conn_lock2().
+ */
+static inline void kdbus_conn_unlock2(struct kdbus_conn *a,
+ struct kdbus_conn *b)
+{
+ if (a)
+ mutex_unlock(&a->lock);
+ if (b && b != a)
+ mutex_unlock(&b->lock);
+}
+
+/**
+ * kdbus_conn_assert_active() - lockdep assert on active lock
+ * @conn: connection that shall be active
+ *
+ * This verifies via lockdep that the caller holds an active reference to the
+ * given connection.
+ */
+static inline void kdbus_conn_assert_active(struct kdbus_conn *conn)
+{
+ lockdep_assert_held(conn);
+}
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/cred.h>
+#include <linux/fs.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include "bus.h"
+#include "domain.h"
+#include "handle.h"
+#include "item.h"
+#include "limits.h"
+#include "util.h"
+
+static void kdbus_domain_control_free(struct kdbus_node *node)
+{
+ kfree(node);
+}
+
+static struct kdbus_node *kdbus_domain_control_new(struct kdbus_domain *domain,
+ unsigned int access)
+{
+ struct kdbus_node *node;
+ int ret;
+
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node)
+ return ERR_PTR(-ENOMEM);
+
+ kdbus_node_init(node, KDBUS_NODE_CONTROL);
+
+ node->free_cb = kdbus_domain_control_free;
+ node->mode = domain->node.mode;
+ node->mode = S_IRUSR | S_IWUSR;
+ if (access & (KDBUS_MAKE_ACCESS_GROUP | KDBUS_MAKE_ACCESS_WORLD))
+ node->mode |= S_IRGRP | S_IWGRP;
+ if (access & KDBUS_MAKE_ACCESS_WORLD)
+ node->mode |= S_IROTH | S_IWOTH;
+
+ ret = kdbus_node_link(node, &domain->node, "control");
+ if (ret < 0)
+ goto exit_free;
+
+ return node;
+
+exit_free:
+ kdbus_node_deactivate(node);
+ kdbus_node_unref(node);
+ return ERR_PTR(ret);
+}
+
+static void kdbus_domain_free(struct kdbus_node *node)
+{
+ struct kdbus_domain *domain =
+ container_of(node, struct kdbus_domain, node);
+
+ put_user_ns(domain->user_namespace);
+ ida_destroy(&domain->user_ida);
+ idr_destroy(&domain->user_idr);
+ kfree(domain);
+}
+
+/**
+ * kdbus_domain_new() - create a new domain
+ * @access: The access mode for this node (KDBUS_MAKE_ACCESS_*)
+ *
+ * Return: a new kdbus_domain on success, ERR_PTR on failure
+ */
+struct kdbus_domain *kdbus_domain_new(unsigned int access)
+{
+ struct kdbus_domain *d;
+ int ret;
+
+ d = kzalloc(sizeof(*d), GFP_KERNEL);
+ if (!d)
+ return ERR_PTR(-ENOMEM);
+
+ kdbus_node_init(&d->node, KDBUS_NODE_DOMAIN);
+
+ d->node.free_cb = kdbus_domain_free;
+ d->node.mode = S_IRUSR | S_IXUSR;
+ if (access & (KDBUS_MAKE_ACCESS_GROUP | KDBUS_MAKE_ACCESS_WORLD))
+ d->node.mode |= S_IRGRP | S_IXGRP;
+ if (access & KDBUS_MAKE_ACCESS_WORLD)
+ d->node.mode |= S_IROTH | S_IXOTH;
+
+ mutex_init(&d->lock);
+ idr_init(&d->user_idr);
+ ida_init(&d->user_ida);
+
+ /* Pin user namespace so we can guarantee domain-unique bus * names. */
+ d->user_namespace = get_user_ns(current_user_ns());
+
+ ret = kdbus_node_link(&d->node, NULL, NULL);
+ if (ret < 0)
+ goto exit_unref;
+
+ return d;
+
+exit_unref:
+ kdbus_node_deactivate(&d->node);
+ kdbus_node_unref(&d->node);
+ return ERR_PTR(ret);
+}
+
+/**
+ * kdbus_domain_ref() - take a domain reference
+ * @domain: Domain
+ *
+ * Return: the domain itself
+ */
+struct kdbus_domain *kdbus_domain_ref(struct kdbus_domain *domain)
+{
+ if (domain)
+ kdbus_node_ref(&domain->node);
+ return domain;
+}
+
+/**
+ * kdbus_domain_unref() - drop a domain reference
+ * @domain: Domain
+ *
+ * When the last reference is dropped, the domain internal structure
+ * is freed.
+ *
+ * Return: NULL
+ */
+struct kdbus_domain *kdbus_domain_unref(struct kdbus_domain *domain)
+{
+ if (domain)
+ kdbus_node_unref(&domain->node);
+ return NULL;
+}
+
+/**
+ * kdbus_domain_populate() - populate static domain nodes
+ * @domain: domain to populate
+ * @access: KDBUS_MAKE_ACCESS_* access restrictions for new nodes
+ *
+ * Allocate and activate static sub-nodes of the given domain. This will fail if
+ * you call it on a non-active node or if the domain was already populated.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_domain_populate(struct kdbus_domain *domain, unsigned int access)
+{
+ struct kdbus_node *control;
+
+ /*
+ * Create a control-node for this domain. We drop our own reference
+ * immediately, effectively causing the node to be deactivated and
+ * released when the parent domain is.
+ */
+ control = kdbus_domain_control_new(domain, access);
+ if (IS_ERR(control))
+ return PTR_ERR(control);
+
+ kdbus_node_activate(control);
+ kdbus_node_unref(control);
+ return 0;
+}
+
+/**
+ * kdbus_user_lookup() - lookup a kdbus_user object
+ * @domain: domain of the user
+ * @uid: uid of the user; INVALID_UID for an anon user
+ *
+ * Lookup the kdbus user accounting object for the given domain. If INVALID_UID
+ * is passed, a new anonymous user is created which is private to the caller.
+ *
+ * Return: The user object is returned, ERR_PTR on failure.
+ */
+struct kdbus_user *kdbus_user_lookup(struct kdbus_domain *domain, kuid_t uid)
+{
+ struct kdbus_user *u = NULL, *old = NULL;
+ int ret;
+
+ mutex_lock(&domain->lock);
+
+ if (uid_valid(uid)) {
+ old = idr_find(&domain->user_idr, __kuid_val(uid));
+ /*
+ * If the object is about to be destroyed, ignore it and
+ * replace the slot in the IDR later on.
+ */
+ if (old && kref_get_unless_zero(&old->kref)) {
+ mutex_unlock(&domain->lock);
+ return old;
+ }
+ }
+
+ u = kzalloc(sizeof(*u), GFP_KERNEL);
+ if (!u) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ kref_init(&u->kref);
+ u->domain = kdbus_domain_ref(domain);
+ u->uid = uid;
+ atomic_set(&u->buses, 0);
+ atomic_set(&u->connections, 0);
+
+ if (uid_valid(uid)) {
+ if (old) {
+ idr_replace(&domain->user_idr, u, __kuid_val(uid));
+ old->uid = INVALID_UID; /* mark old as removed */
+ } else {
+ ret = idr_alloc(&domain->user_idr, u, __kuid_val(uid),
+ __kuid_val(uid) + 1, GFP_KERNEL);
+ if (ret < 0)
+ goto exit;
+ }
+ }
+
+ /*
+ * Allocate the smallest possible index for this user; used
+ * in arrays for accounting user quota in receiver queues.
+ */
+ ret = ida_simple_get(&domain->user_ida, 1, 0, GFP_KERNEL);
+ if (ret < 0)
+ goto exit;
+
+ u->id = ret;
+ mutex_unlock(&domain->lock);
+ return u;
+
+exit:
+ if (u) {
+ if (uid_valid(u->uid))
+ idr_remove(&domain->user_idr, __kuid_val(u->uid));
+ kdbus_domain_unref(u->domain);
+ kfree(u);
+ }
+ mutex_unlock(&domain->lock);
+ return ERR_PTR(ret);
+}
+
+static void __kdbus_user_free(struct kref *kref)
+{
+ struct kdbus_user *user = container_of(kref, struct kdbus_user, kref);
+
+ WARN_ON(atomic_read(&user->buses) > 0);
+ WARN_ON(atomic_read(&user->connections) > 0);
+
+ mutex_lock(&user->domain->lock);
+ ida_simple_remove(&user->domain->user_ida, user->id);
+ if (uid_valid(user->uid))
+ idr_remove(&user->domain->user_idr, __kuid_val(user->uid));
+ mutex_unlock(&user->domain->lock);
+
+ kdbus_domain_unref(user->domain);
+ kfree(user);
+}
+
+/**
+ * kdbus_user_ref() - take a user reference
+ * @u: User
+ *
+ * Return: @u is returned
+ */
+struct kdbus_user *kdbus_user_ref(struct kdbus_user *u)
+{
+ if (u)
+ kref_get(&u->kref);
+ return u;
+}
+
+/**
+ * kdbus_user_unref() - drop a user reference
+ * @u: User
+ *
+ * Return: NULL
+ */
+struct kdbus_user *kdbus_user_unref(struct kdbus_user *u)
+{
+ if (u)
+ kref_put(&u->kref, __kdbus_user_free);
+ return NULL;
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_DOMAIN_H
+#define __KDBUS_DOMAIN_H
+
+#include <linux/fs.h>
+#include <linux/idr.h>
+#include <linux/kref.h>
+#include <linux/user_namespace.h>
+
+#include "node.h"
+
+/**
+ * struct kdbus_domain - domain for buses
+ * @node: Underlying API node
+ * @lock: Domain data lock
+ * @last_id: Last used object id
+ * @user_idr: Set of all users indexed by UID
+ * @user_ida: Set of all users to compute small indices
+ * @user_namespace: User namespace, pinned at creation time
+ * @dentry: Root dentry of VFS mount (don't use outside of kdbusfs)
+ */
+struct kdbus_domain {
+ struct kdbus_node node;
+ struct mutex lock;
+ atomic64_t last_id;
+ struct idr user_idr;
+ struct ida user_ida;
+ struct user_namespace *user_namespace;
+ struct dentry *dentry;
+};
+
+/**
+ * struct kdbus_user - resource accounting for users
+ * @kref: Reference counter
+ * @domain: Domain of the user
+ * @id: Index of this user
+ * @uid: UID of the user
+ * @buses: Number of buses the user has created
+ * @connections: Number of connections the user has created
+ */
+struct kdbus_user {
+ struct kref kref;
+ struct kdbus_domain *domain;
+ unsigned int id;
+ kuid_t uid;
+ atomic_t buses;
+ atomic_t connections;
+};
+
+#define kdbus_domain_from_node(_node) \
+ container_of((_node), struct kdbus_domain, node)
+
+struct kdbus_domain *kdbus_domain_new(unsigned int access);
+struct kdbus_domain *kdbus_domain_ref(struct kdbus_domain *domain);
+struct kdbus_domain *kdbus_domain_unref(struct kdbus_domain *domain);
+int kdbus_domain_populate(struct kdbus_domain *domain, unsigned int access);
+
+#define KDBUS_USER_KERNEL_ID 0 /* ID 0 is reserved for kernel accounting */
+
+struct kdbus_user *kdbus_user_lookup(struct kdbus_domain *domain, kuid_t uid);
+struct kdbus_user *kdbus_user_ref(struct kdbus_user *u);
+struct kdbus_user *kdbus_user_unref(struct kdbus_user *u);
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/cred.h>
+#include <linux/fs.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "domain.h"
+#include "endpoint.h"
+#include "handle.h"
+#include "item.h"
+#include "message.h"
+#include "policy.h"
+
+static void kdbus_ep_free(struct kdbus_node *node)
+{
+ struct kdbus_ep *ep = container_of(node, struct kdbus_ep, node);
+
+ WARN_ON(!list_empty(&ep->conn_list));
+
+ kdbus_policy_db_clear(&ep->policy_db);
+ kdbus_bus_unref(ep->bus);
+ kdbus_user_unref(ep->user);
+ kfree(ep);
+}
+
+static void kdbus_ep_release(struct kdbus_node *node, bool was_active)
+{
+ struct kdbus_ep *ep = container_of(node, struct kdbus_ep, node);
+
+ /* disconnect all connections to this endpoint */
+ for (;;) {
+ struct kdbus_conn *conn;
+
+ mutex_lock(&ep->lock);
+ conn = list_first_entry_or_null(&ep->conn_list,
+ struct kdbus_conn,
+ ep_entry);
+ if (!conn) {
+ mutex_unlock(&ep->lock);
+ break;
+ }
+
+ /* take reference, release lock, disconnect without lock */
+ kdbus_conn_ref(conn);
+ mutex_unlock(&ep->lock);
+
+ kdbus_conn_disconnect(conn, false);
+ kdbus_conn_unref(conn);
+ }
+}
+
+/**
+ * kdbus_ep_new() - create a new endpoint
+ * @bus: The bus this endpoint will be created for
+ * @name: The name of the endpoint
+ * @access: The access flags for this node (KDBUS_MAKE_ACCESS_*)
+ * @uid: The uid of the node
+ * @gid: The gid of the node
+ * @is_custom: Whether this is a custom endpoint
+ *
+ * This function will create a new endpoint with the given
+ * name and properties for a given bus.
+ *
+ * Return: a new kdbus_ep on success, ERR_PTR on failure.
+ */
+struct kdbus_ep *kdbus_ep_new(struct kdbus_bus *bus, const char *name,
+ unsigned int access, kuid_t uid, kgid_t gid,
+ bool is_custom)
+{
+ struct kdbus_ep *e;
+ int ret;
+
+ /*
+ * Validate only custom endpoints names, default endpoints
+ * with a "bus" name are created when the bus is created
+ */
+ if (is_custom) {
+ ret = kdbus_verify_uid_prefix(name, bus->domain->user_namespace,
+ uid);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ }
+
+ e = kzalloc(sizeof(*e), GFP_KERNEL);
+ if (!e)
+ return ERR_PTR(-ENOMEM);
+
+ kdbus_node_init(&e->node, KDBUS_NODE_ENDPOINT);
+
+ e->node.free_cb = kdbus_ep_free;
+ e->node.release_cb = kdbus_ep_release;
+ e->node.uid = uid;
+ e->node.gid = gid;
+ e->node.mode = S_IRUSR | S_IWUSR;
+ if (access & (KDBUS_MAKE_ACCESS_GROUP | KDBUS_MAKE_ACCESS_WORLD))
+ e->node.mode |= S_IRGRP | S_IWGRP;
+ if (access & KDBUS_MAKE_ACCESS_WORLD)
+ e->node.mode |= S_IROTH | S_IWOTH;
+
+ mutex_init(&e->lock);
+ INIT_LIST_HEAD(&e->conn_list);
+ kdbus_policy_db_init(&e->policy_db);
+ e->bus = kdbus_bus_ref(bus);
+
+ ret = kdbus_node_link(&e->node, &bus->node, name);
+ if (ret < 0)
+ goto exit_unref;
+
+ /*
+ * Transactions on custom endpoints are never accounted on the global
+ * user limits. Instead, for each custom endpoint, we create a custom,
+ * unique user, which all transactions are accounted on. Regardless of
+ * the user using that endpoint, it is always accounted on the same
+ * user-object. This budget is not shared with ordinary users on
+ * non-custom endpoints.
+ */
+ if (is_custom) {
+ e->user = kdbus_user_lookup(bus->domain, INVALID_UID);
+ if (IS_ERR(e->user)) {
+ ret = PTR_ERR(e->user);
+ e->user = NULL;
+ goto exit_unref;
+ }
+ }
+
+ return e;
+
+exit_unref:
+ kdbus_node_deactivate(&e->node);
+ kdbus_node_unref(&e->node);
+ return ERR_PTR(ret);
+}
+
+/**
+ * kdbus_ep_ref() - increase the reference counter of a kdbus_ep
+ * @ep: The endpoint to reference
+ *
+ * Every user of an endpoint, except for its creator, must add a reference to
+ * the kdbus_ep instance using this function.
+ *
+ * Return: the ep itself
+ */
+struct kdbus_ep *kdbus_ep_ref(struct kdbus_ep *ep)
+{
+ if (ep)
+ kdbus_node_ref(&ep->node);
+ return ep;
+}
+
+/**
+ * kdbus_ep_unref() - decrease the reference counter of a kdbus_ep
+ * @ep: The ep to unref
+ *
+ * Release a reference. If the reference count drops to 0, the ep will be
+ * freed.
+ *
+ * Return: NULL
+ */
+struct kdbus_ep *kdbus_ep_unref(struct kdbus_ep *ep)
+{
+ if (ep)
+ kdbus_node_unref(&ep->node);
+ return NULL;
+}
+
+/**
+ * kdbus_ep_is_privileged() - check whether a file is privileged
+ * @ep: endpoint to operate on
+ * @file: file to test
+ *
+ * Return: True if @file is privileged in the domain of @ep.
+ */
+bool kdbus_ep_is_privileged(struct kdbus_ep *ep, struct file *file)
+{
+ return !ep->user &&
+ file_ns_capable(file, ep->bus->domain->user_namespace,
+ CAP_IPC_OWNER);
+}
+
+/**
+ * kdbus_ep_is_owner() - check whether a file should be treated as bus owner
+ * @ep: endpoint to operate on
+ * @file: file to test
+ *
+ * Return: True if @file should be treated as bus owner on @ep
+ */
+bool kdbus_ep_is_owner(struct kdbus_ep *ep, struct file *file)
+{
+ return !ep->user &&
+ (uid_eq(file->f_cred->euid, ep->bus->node.uid) ||
+ kdbus_ep_is_privileged(ep, file));
+}
+
+/**
+ * kdbus_cmd_ep_make() - handle KDBUS_CMD_ENDPOINT_MAKE
+ * @bus: bus to operate on
+ * @argp: command payload
+ *
+ * Return: NULL or newly created endpoint on success, ERR_PTR on failure.
+ */
+struct kdbus_ep *kdbus_cmd_ep_make(struct kdbus_bus *bus, void __user *argp)
+{
+ const char *item_make_name;
+ struct kdbus_ep *ep = NULL;
+ struct kdbus_cmd *cmd;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_MAKE_NAME, .mandatory = true },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_MAKE_ACCESS_GROUP |
+ KDBUS_MAKE_ACCESS_WORLD,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0)
+ return NULL;
+
+ item_make_name = argv[1].item->str;
+
+ ep = kdbus_ep_new(bus, item_make_name, cmd->flags,
+ current_euid(), current_egid(), true);
+ if (IS_ERR(ep)) {
+ ret = PTR_ERR(ep);
+ ep = NULL;
+ goto exit;
+ }
+
+ if (!kdbus_node_activate(&ep->node)) {
+ ret = -ESHUTDOWN;
+ goto exit;
+ }
+
+exit:
+ ret = kdbus_args_clear(&args, ret);
+ if (ret < 0) {
+ if (ep) {
+ kdbus_node_deactivate(&ep->node);
+ kdbus_ep_unref(ep);
+ }
+ return ERR_PTR(ret);
+ }
+ return ep;
+}
+
+/**
+ * kdbus_cmd_ep_update() - handle KDBUS_CMD_ENDPOINT_UPDATE
+ * @ep: endpoint to operate on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_ep_update(struct kdbus_ep *ep, void __user *argp)
+{
+ struct kdbus_cmd *cmd;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_NAME, .multiple = true },
+ { .type = KDBUS_ITEM_POLICY_ACCESS, .multiple = true },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ ret = kdbus_policy_set(&ep->policy_db, args.items, args.items_size,
+ 0, true, ep);
+ return kdbus_args_clear(&args, ret);
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_ENDPOINT_H
+#define __KDBUS_ENDPOINT_H
+
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/uidgid.h>
+#include "node.h"
+#include "policy.h"
+
+struct kdbus_bus;
+struct kdbus_user;
+
+/**
+ * struct kdbus_ep - endpoint to access a bus
+ * @node: The kdbus node
+ * @lock: Endpoint data lock
+ * @bus: Bus behind this endpoint
+ * @user: Custom enpoints account against an anonymous user
+ * @policy_db: Uploaded policy
+ * @conn_list: Connections of this endpoint
+ *
+ * An endpoint offers access to a bus; the default endpoint node name is "bus".
+ * Additional custom endpoints to the same bus can be created and they can
+ * carry their own policies/filters.
+ */
+struct kdbus_ep {
+ struct kdbus_node node;
+ struct mutex lock;
+
+ /* static */
+ struct kdbus_bus *bus;
+ struct kdbus_user *user;
+
+ /* protected by own locks */
+ struct kdbus_policy_db policy_db;
+
+ /* protected by ep->lock */
+ struct list_head conn_list;
+};
+
+#define kdbus_ep_from_node(_node) \
+ container_of((_node), struct kdbus_ep, node)
+
+struct kdbus_ep *kdbus_ep_new(struct kdbus_bus *bus, const char *name,
+ unsigned int access, kuid_t uid, kgid_t gid,
+ bool policy);
+struct kdbus_ep *kdbus_ep_ref(struct kdbus_ep *ep);
+struct kdbus_ep *kdbus_ep_unref(struct kdbus_ep *ep);
+
+bool kdbus_ep_is_privileged(struct kdbus_ep *ep, struct file *file);
+bool kdbus_ep_is_owner(struct kdbus_ep *ep, struct file *file);
+
+struct kdbus_ep *kdbus_cmd_ep_make(struct kdbus_bus *bus, void __user *argp);
+int kdbus_cmd_ep_update(struct kdbus_ep *ep, void __user *argp);
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/dcache.h>
+#include <linux/fs.h>
+#include <linux/fsnotify.h>
+#include <linux/init.h>
+#include <linux/ipc_namespace.h>
+#include <linux/magic.h>
+#include <linux/module.h>
+#include <uapi/linux/mount.h>
+#include <linux/mutex.h>
+#include <linux/namei.h>
+#include <linux/pagemap.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include "bus.h"
+#include "domain.h"
+#include "endpoint.h"
+#include "fs.h"
+#include "handle.h"
+#include "node.h"
+
+#define kdbus_node_from_dentry(_dentry) \
+ ((struct kdbus_node *)(_dentry)->d_fsdata)
+
+static struct inode *fs_inode_get(struct super_block *sb,
+ struct kdbus_node *node);
+
+/*
+ * Directory Management
+ */
+
+static inline unsigned char kdbus_dt_type(struct kdbus_node *node)
+{
+ switch (node->type) {
+ case KDBUS_NODE_DOMAIN:
+ case KDBUS_NODE_BUS:
+ return DT_DIR;
+ case KDBUS_NODE_CONTROL:
+ case KDBUS_NODE_ENDPOINT:
+ return DT_REG;
+ }
+
+ return DT_UNKNOWN;
+}
+
+static int fs_dir_fop_iterate(struct file *file, struct dir_context *ctx)
+{
+ struct dentry *dentry = file->f_path.dentry;
+ struct kdbus_node *parent = kdbus_node_from_dentry(dentry);
+ struct kdbus_node *old, *next = file->private_data;
+
+ /*
+ * kdbusfs directory iterator (modelled after sysfs/kernfs)
+ * When iterating kdbusfs directories, we iterate all children of the
+ * parent kdbus_node object. We use ctx->pos to store the hash of the
+ * child and file->private_data to store a reference to the next node
+ * object. If ctx->pos is not modified via llseek while you iterate a
+ * directory, then we use the file->private_data node pointer to
+ * directly access the next node in the tree.
+ * However, if you directly seek on the directory, we have to find the
+ * closest node to that position and cannot use our node pointer. This
+ * means iterating the rb-tree to find the closest match and start over
+ * from there.
+ * Note that hash values are not necessarily unique. Therefore, llseek
+ * is not guaranteed to seek to the same node that you got when you
+ * retrieved the position. Seeking to 0, 1, 2 and >=INT_MAX is safe,
+ * though. We could use the inode-number as position, but this would
+ * require another rb-tree for fast access. Kernfs and others already
+ * ignore those conflicts, so we should be fine, too.
+ */
+
+ if (!dir_emit_dots(file, ctx))
+ return 0;
+
+ /* acquire @next; if deactivated, or seek detected, find next node */
+ old = next;
+ if (next && ctx->pos == next->hash) {
+ if (kdbus_node_acquire(next))
+ kdbus_node_ref(next);
+ else
+ next = kdbus_node_next_child(parent, next);
+ } else {
+ next = kdbus_node_find_closest(parent, ctx->pos);
+ }
+ kdbus_node_unref(old);
+
+ while (next) {
+ /* emit @next */
+ file->private_data = next;
+ ctx->pos = next->hash;
+
+ kdbus_node_release(next);
+
+ if (!dir_emit(ctx, next->name, strlen(next->name), next->id,
+ kdbus_dt_type(next)))
+ return 0;
+
+ /* find next node after @next */
+ old = next;
+ next = kdbus_node_next_child(parent, next);
+ kdbus_node_unref(old);
+ }
+
+ file->private_data = NULL;
+ ctx->pos = INT_MAX;
+
+ return 0;
+}
+
+static loff_t fs_dir_fop_llseek(struct file *file, loff_t offset, int whence)
+{
+ struct inode *inode = file_inode(file);
+ loff_t ret;
+
+ /* protect f_off against fop_iterate */
+ inode_lock(inode);
+ ret = generic_file_llseek(file, offset, whence);
+ inode_unlock(inode);
+
+ return ret;
+}
+
+static int fs_dir_fop_release(struct inode *inode, struct file *file)
+{
+ kdbus_node_unref(file->private_data);
+ return 0;
+}
+
+static const struct file_operations fs_dir_fops = {
+ .read = generic_read_dir,
+ .iterate = fs_dir_fop_iterate,
+ .llseek = fs_dir_fop_llseek,
+ .release = fs_dir_fop_release,
+};
+
+static struct dentry *fs_dir_iop_lookup(struct inode *dir,
+ struct dentry *dentry,
+ unsigned int flags)
+{
+ struct dentry *dnew = NULL;
+ struct kdbus_node *parent;
+ struct kdbus_node *node;
+ struct inode *inode;
+
+ parent = kdbus_node_from_dentry(dentry->d_parent);
+ if (!kdbus_node_acquire(parent))
+ return NULL;
+
+ /* returns reference to _acquired_ child node */
+ node = kdbus_node_find_child(parent, dentry->d_name.name);
+ if (node) {
+ dentry->d_fsdata = node;
+ inode = fs_inode_get(dir->i_sb, node);
+ if (IS_ERR(inode))
+ dnew = ERR_CAST(inode);
+ else
+ dnew = d_splice_alias(inode, dentry);
+
+ kdbus_node_release(node);
+ }
+
+ kdbus_node_release(parent);
+ return dnew;
+}
+
+static const struct inode_operations fs_dir_iops = {
+ .permission = generic_permission,
+ .lookup = fs_dir_iop_lookup,
+};
+
+/*
+ * Inode Management
+ */
+
+static const struct inode_operations fs_inode_iops = {
+ .permission = generic_permission,
+};
+
+static struct inode *fs_inode_get(struct super_block *sb,
+ struct kdbus_node *node)
+{
+ struct inode *inode;
+
+ inode = iget_locked(sb, node->id);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+ if (!(inode->i_state & I_NEW))
+ return inode;
+
+ inode->i_private = kdbus_node_ref(node);
+ inode->i_mapping->a_ops = &empty_aops;
+ inode->i_mode = node->mode & S_IALLUGO;
+ inode->i_atime = inode->i_ctime = inode->i_mtime = current_time(inode);
+ inode->i_uid = node->uid;
+ inode->i_gid = node->gid;
+
+ switch (node->type) {
+ case KDBUS_NODE_DOMAIN:
+ case KDBUS_NODE_BUS:
+ inode->i_mode |= S_IFDIR;
+ inode->i_op = &fs_dir_iops;
+ inode->i_fop = &fs_dir_fops;
+ set_nlink(inode, 2);
+ break;
+ case KDBUS_NODE_CONTROL:
+ case KDBUS_NODE_ENDPOINT:
+ inode->i_mode |= S_IFREG;
+ inode->i_op = &fs_inode_iops;
+ inode->i_fop = &kdbus_handle_ops;
+ break;
+ }
+
+ unlock_new_inode(inode);
+
+ return inode;
+}
+
+/*
+ * Superblock Management
+ */
+
+static int fs_super_dop_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ struct kdbus_node *node;
+
+ /* Force lookup on negatives */
+ if (!dentry->d_inode)
+ return 0;
+
+ node = kdbus_node_from_dentry(dentry);
+
+ /* see whether the node has been removed */
+ if (!kdbus_node_is_active(node))
+ return 0;
+
+ return 1;
+}
+
+static void fs_super_dop_release(struct dentry *dentry)
+{
+ kdbus_node_unref(dentry->d_fsdata);
+}
+
+static const struct dentry_operations fs_super_dops = {
+ .d_revalidate = fs_super_dop_revalidate,
+ .d_release = fs_super_dop_release,
+};
+
+static void fs_super_sop_evict_inode(struct inode *inode)
+{
+ struct kdbus_node *node = kdbus_node_from_inode(inode);
+
+ truncate_inode_pages_final(&inode->i_data);
+ clear_inode(inode);
+ kdbus_node_unref(node);
+}
+
+static const struct super_operations fs_super_sops = {
+ .statfs = simple_statfs,
+ .drop_inode = generic_delete_inode,
+ .evict_inode = fs_super_sop_evict_inode,
+};
+
+static int fs_super_fill(struct super_block *sb)
+{
+ struct kdbus_domain *domain = sb->s_fs_info;
+ struct inode *inode;
+ int ret;
+
+ sb->s_blocksize = PAGE_SIZE;
+ sb->s_blocksize_bits = PAGE_SHIFT;
+ sb->s_magic = KDBUS_SUPER_MAGIC;
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_op = &fs_super_sops;
+ sb->s_time_gran = 1;
+
+ inode = fs_inode_get(sb, &domain->node);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root) {
+ /* d_make_root iput()s the inode on failure */
+ return -ENOMEM;
+ }
+
+ /* sb holds domain reference */
+ sb->s_root->d_fsdata = &domain->node;
+ sb->s_d_op = &fs_super_dops;
+
+ /* sb holds root reference */
+ domain->dentry = sb->s_root;
+
+ if (!kdbus_node_activate(&domain->node))
+ return -ESHUTDOWN;
+
+ ret = kdbus_domain_populate(domain, KDBUS_MAKE_ACCESS_WORLD);
+ if (ret < 0)
+ return ret;
+
+ sb->s_flags |= MS_ACTIVE;
+ return 0;
+}
+
+static void fs_super_kill(struct super_block *sb)
+{
+ struct kdbus_domain *domain = sb->s_fs_info;
+
+ if (domain) {
+ kdbus_node_deactivate(&domain->node);
+ domain->dentry = NULL;
+ }
+
+ kill_anon_super(sb);
+ kdbus_domain_unref(domain);
+}
+
+static int fs_super_set(struct super_block *sb, void *data)
+{
+ int ret;
+
+ ret = set_anon_super(sb, data);
+ if (!ret)
+ sb->s_fs_info = data;
+
+ return ret;
+}
+
+static struct dentry *fs_super_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name,
+ void *data)
+{
+ struct kdbus_domain *domain;
+ struct super_block *sb;
+ int ret;
+
+ domain = kdbus_domain_new(KDBUS_MAKE_ACCESS_WORLD);
+ if (IS_ERR(domain))
+ return ERR_CAST(domain);
+
+ sb = sget(fs_type, NULL, fs_super_set, flags, domain);
+ if (IS_ERR(sb)) {
+ kdbus_node_deactivate(&domain->node);
+ kdbus_domain_unref(domain);
+ return ERR_CAST(sb);
+ }
+
+ WARN_ON(sb->s_fs_info != domain);
+ WARN_ON(sb->s_root);
+
+ ret = fs_super_fill(sb);
+ if (ret < 0) {
+ /* calls into ->kill_sb() when done */
+ deactivate_locked_super(sb);
+ return ERR_PTR(ret);
+ }
+
+ return dget(sb->s_root);
+}
+
+static struct file_system_type fs_type = {
+ .name = KBUILD_MODNAME "fs",
+ .owner = THIS_MODULE,
+ .mount = fs_super_mount,
+ .kill_sb = fs_super_kill,
+ .fs_flags = FS_USERNS_MOUNT,
+};
+
+/**
+ * kdbus_fs_init() - register kdbus filesystem
+ *
+ * This registers a filesystem with the VFS layer. The filesystem is called
+ * `KBUILD_MODNAME "fs"', which usually resolves to `kdbusfs'. The nameing
+ * scheme allows to set KBUILD_MODNAME to "kdbus2" and you will get an
+ * independent filesystem for developers.
+ *
+ * Each mount of the kdbusfs filesystem has an kdbus_domain attached.
+ * Operations on this mount will only affect the attached domain. On each mount
+ * a new domain is automatically created and used for this mount exclusively.
+ * If you want to share a domain across multiple mounts, you need to bind-mount
+ * it.
+ *
+ * Mounts of kdbusfs (with a different domain each) are unrelated to each other
+ * and will never have any effect on any domain but their own.
+ *
+ * Return: 0 on success, negative error otherwise.
+ */
+int kdbus_fs_init(void)
+{
+ return register_filesystem(&fs_type);
+}
+
+/**
+ * kdbus_fs_exit() - unregister kdbus filesystem
+ *
+ * This does the reverse to kdbus_fs_init(). It unregisters the kdbusfs
+ * filesystem from VFS and cleans up any allocated resources.
+ */
+void kdbus_fs_exit(void)
+{
+ unregister_filesystem(&fs_type);
+}
+
+/* acquire domain of @node, making sure all ancestors are active */
+static struct kdbus_domain *fs_acquire_domain(struct kdbus_node *node)
+{
+ struct kdbus_domain *domain;
+ struct kdbus_node *iter;
+
+ /* caller must guarantee that @node is linked */
+ for (iter = node; iter->parent; iter = iter->parent)
+ if (!kdbus_node_is_active(iter->parent))
+ return NULL;
+
+ /* root nodes are always domains */
+ if (WARN_ON(iter->type != KDBUS_NODE_DOMAIN))
+ return NULL;
+
+ domain = kdbus_domain_from_node(iter);
+ if (!kdbus_node_acquire(&domain->node))
+ return NULL;
+
+ return domain;
+}
+
+/**
+ * kdbus_fs_flush() - flush dcache entries of a node
+ * @node: Node to flush entries of
+ *
+ * This flushes all VFS filesystem cache entries for a node and all its
+ * children. This should be called whenever a node is destroyed during
+ * runtime. It will flush the cache entries so the linked objects can be
+ * deallocated.
+ *
+ * This is a no-op if you call it on active nodes (they really should stay in
+ * cache) or on nodes with deactivated parents (flushing the parent is enough).
+ * Furthermore, there is no need to call it on nodes whose lifetime is bound to
+ * their parents'. In those cases, the parent-flush will always also flush the
+ * children.
+ */
+void kdbus_fs_flush(struct kdbus_node *node)
+{
+ struct dentry *dentry, *parent_dentry = NULL;
+ struct kdbus_domain *domain;
+ struct qstr name;
+
+ /* active nodes should remain in cache */
+ if (!kdbus_node_is_deactivated(node))
+ return;
+
+ /* nodes that were never linked were never instantiated */
+ if (!node->parent)
+ return;
+
+ /* acquire domain and verify all ancestors are active */
+ domain = fs_acquire_domain(node);
+ if (!domain)
+ return;
+
+ switch (node->type) {
+ case KDBUS_NODE_ENDPOINT:
+ if (WARN_ON(!node->parent || !node->parent->name))
+ goto exit;
+
+ name.name = node->parent->name;
+ name.len = strlen(node->parent->name);
+ parent_dentry = d_hash_and_lookup(domain->dentry, &name);
+ if (IS_ERR_OR_NULL(parent_dentry))
+ goto exit;
+
+ /* fallthrough */
+ case KDBUS_NODE_BUS:
+ if (WARN_ON(!node->name))
+ goto exit;
+
+ name.name = node->name;
+ name.len = strlen(node->name);
+ dentry = d_hash_and_lookup(parent_dentry ? : domain->dentry,
+ &name);
+ if (!IS_ERR_OR_NULL(dentry)) {
+ d_invalidate(dentry);
+ dput(dentry);
+ }
+
+ dput(parent_dentry);
+ break;
+
+ default:
+ /* all other types are bound to their parent lifetime */
+ break;
+ }
+
+exit:
+ kdbus_node_release(&domain->node);
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUSFS_H
+#define __KDBUSFS_H
+
+#include <linux/kernel.h>
+
+struct kdbus_node;
+
+int kdbus_fs_init(void);
+void kdbus_fs_exit(void);
+void kdbus_fs_flush(struct kdbus_node *node);
+
+#define kdbus_node_from_inode(_inode) \
+ ((struct kdbus_node *)(_inode)->i_private)
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/kdev_t.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "endpoint.h"
+#include "fs.h"
+#include "handle.h"
+#include "item.h"
+#include "match.h"
+#include "message.h"
+#include "names.h"
+#include "domain.h"
+#include "policy.h"
+
+static int kdbus_args_verify(struct kdbus_args *args)
+{
+ struct kdbus_item *item;
+ size_t i;
+ int ret;
+
+ KDBUS_ITEMS_FOREACH(item, args->items, args->items_size) {
+ struct kdbus_arg *arg = NULL;
+
+ if (!KDBUS_ITEM_VALID(item, args->items, args->items_size))
+ return -EINVAL;
+
+ for (i = 0; i < args->argc; ++i)
+ if (args->argv[i].type == item->type)
+ break;
+ if (i >= args->argc)
+ return -EINVAL;
+
+ arg = &args->argv[i];
+
+ ret = kdbus_item_validate(item);
+ if (ret < 0)
+ return ret;
+
+ if (arg->item && !arg->multiple)
+ return -EINVAL;
+
+ arg->item = item;
+ }
+
+ if (!KDBUS_ITEMS_END(item, args->items, args->items_size))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int kdbus_args_negotiate(struct kdbus_args *args)
+{
+ struct kdbus_item __user *user;
+ struct kdbus_item *negotiation;
+ size_t i, j, num;
+
+ /*
+ * If KDBUS_FLAG_NEGOTIATE is set, we overwrite the flags field with
+ * the set of supported flags. Furthermore, if an KDBUS_ITEM_NEGOTIATE
+ * item is passed, we iterate its payload (array of u64, each set to an
+ * item type) and clear all unsupported item-types to 0.
+ * The caller might do this recursively, if other flags or objects are
+ * embedded in the payload itself.
+ */
+
+ if (args->cmd->flags & KDBUS_FLAG_NEGOTIATE) {
+ if (put_user(args->allowed_flags & ~KDBUS_FLAG_NEGOTIATE,
+ &args->user->flags))
+ return -EFAULT;
+ }
+
+ if (args->argc < 1 || args->argv[0].type != KDBUS_ITEM_NEGOTIATE ||
+ !args->argv[0].item)
+ return 0;
+
+ negotiation = args->argv[0].item;
+ user = (struct kdbus_item __user *)
+ ((u8 __user *)args->user +
+ ((u8 *)negotiation - (u8 *)args->cmd));
+ num = KDBUS_ITEM_PAYLOAD_SIZE(negotiation) / sizeof(u64);
+
+ for (i = 0; i < num; ++i) {
+ for (j = 0; j < args->argc; ++j)
+ if (negotiation->data64[i] == args->argv[j].type)
+ break;
+
+ if (j < args->argc)
+ continue;
+
+ /* this item is not supported, clear it out */
+ negotiation->data64[i] = 0;
+ if (put_user(negotiation->data64[i], &user->data64[i]))
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+/**
+ * __kdbus_args_parse() - parse payload of kdbus command
+ * @args: object to parse data into
+ * @is_cmd: whether this is a command or msg payload
+ * @argp: user-space location of command payload to parse
+ * @type_size: overall size of command payload to parse
+ * @items_offset: offset of items array in command payload
+ * @out: output variable to store pointer to copied payload
+ *
+ * This parses the ioctl payload at user-space location @argp into @args. @args
+ * must be pre-initialized by the caller to reflect the supported flags and
+ * items of this command. This parser will then copy the command payload into
+ * kernel-space, verify correctness and consistency and cache pointers to parsed
+ * items and other data in @args.
+ *
+ * If this function succeeded, you must call kdbus_args_clear() to release
+ * allocated resources before destroying @args.
+ *
+ * This can also be used to import kdbus_msg objects. In that case, @is_cmd must
+ * be set to 'false' and the 'return_flags' field will not be touched (as it
+ * doesn't exist on kdbus_msg).
+ *
+ * Return: On failure a negative error code is returned. Otherwise, 1 is
+ * returned if negotiation was requested, 0 if not.
+ */
+int __kdbus_args_parse(struct kdbus_args *args, bool is_cmd, void __user *argp,
+ size_t type_size, size_t items_offset, void **out)
+{
+ u64 user_size;
+ int ret, i;
+
+ ret = kdbus_copy_from_user(&user_size, argp, sizeof(user_size));
+ if (ret < 0)
+ return ret;
+
+ if (user_size < type_size)
+ return -EINVAL;
+ if (user_size > KDBUS_CMD_MAX_SIZE)
+ return -EMSGSIZE;
+
+ if (user_size <= sizeof(args->cmd_buf)) {
+ if (copy_from_user(args->cmd_buf, argp, user_size))
+ return -EFAULT;
+ args->cmd = (void*)args->cmd_buf;
+ } else {
+ args->cmd = memdup_user(argp, user_size);
+ if (IS_ERR(args->cmd))
+ return PTR_ERR(args->cmd);
+ }
+
+ if (args->cmd->size != user_size) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ if (is_cmd)
+ args->cmd->return_flags = 0;
+ args->user = argp;
+ args->items = (void *)((u8 *)args->cmd + items_offset);
+ args->items_size = args->cmd->size - items_offset;
+ args->is_cmd = is_cmd;
+
+ if (args->cmd->flags & ~args->allowed_flags) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ ret = kdbus_args_verify(args);
+ if (ret < 0)
+ goto error;
+
+ ret = kdbus_args_negotiate(args);
+ if (ret < 0)
+ goto error;
+
+ /* mandatory items must be given (but not on negotiation) */
+ if (!(args->cmd->flags & KDBUS_FLAG_NEGOTIATE)) {
+ for (i = 0; i < args->argc; ++i)
+ if (args->argv[i].mandatory && !args->argv[i].item) {
+ ret = -EINVAL;
+ goto error;
+ }
+ }
+
+ *out = args->cmd;
+ return !!(args->cmd->flags & KDBUS_FLAG_NEGOTIATE);
+
+error:
+ return kdbus_args_clear(args, ret);
+}
+
+/**
+ * kdbus_args_clear() - release allocated command resources
+ * @args: object to release resources of
+ * @ret: return value of this command
+ *
+ * This frees all allocated resources on @args and copies the command result
+ * flags into user-space. @ret is usually returned unchanged by this function,
+ * so it can be used in the final 'return' statement of the command handler.
+ *
+ * Return: -EFAULT if return values cannot be copied into user-space, otherwise
+ * @ret is returned unchanged.
+ */
+int kdbus_args_clear(struct kdbus_args *args, int ret)
+{
+ if (!args)
+ return ret;
+
+ if (!IS_ERR_OR_NULL(args->cmd)) {
+ if (args->is_cmd && put_user(args->cmd->return_flags,
+ &args->user->return_flags))
+ ret = -EFAULT;
+ if (args->cmd != (void*)args->cmd_buf)
+ kfree(args->cmd);
+ args->cmd = NULL;
+ }
+
+ return ret;
+}
+
+/**
+ * enum kdbus_handle_type - type an handle can be of
+ * @KDBUS_HANDLE_NONE: no type set, yet
+ * @KDBUS_HANDLE_BUS_OWNER: bus owner
+ * @KDBUS_HANDLE_EP_OWNER: endpoint owner
+ * @KDBUS_HANDLE_CONNECTED: endpoint connection after HELLO
+ */
+enum kdbus_handle_type {
+ KDBUS_HANDLE_NONE,
+ KDBUS_HANDLE_BUS_OWNER,
+ KDBUS_HANDLE_EP_OWNER,
+ KDBUS_HANDLE_CONNECTED,
+};
+
+/**
+ * struct kdbus_handle - handle to the kdbus system
+ * @lock: handle lock
+ * @type: type of this handle (KDBUS_HANDLE_*)
+ * @bus_owner: bus this handle owns
+ * @ep_owner: endpoint this handle owns
+ * @conn: connection this handle owns
+ */
+struct kdbus_handle {
+ struct mutex lock;
+
+ enum kdbus_handle_type type;
+ union {
+ struct kdbus_bus *bus_owner;
+ struct kdbus_ep *ep_owner;
+ struct kdbus_conn *conn;
+ };
+};
+
+static int kdbus_handle_open(struct inode *inode, struct file *file)
+{
+ struct kdbus_handle *handle;
+ struct kdbus_node *node;
+ int ret;
+
+ node = kdbus_node_from_inode(inode);
+ if (!kdbus_node_acquire(node))
+ return -ESHUTDOWN;
+
+ handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+ if (!handle) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ mutex_init(&handle->lock);
+ handle->type = KDBUS_HANDLE_NONE;
+
+ file->private_data = handle;
+ ret = 0;
+
+exit:
+ kdbus_node_release(node);
+ return ret;
+}
+
+static int kdbus_handle_release(struct inode *inode, struct file *file)
+{
+ struct kdbus_handle *handle = file->private_data;
+
+ switch (handle->type) {
+ case KDBUS_HANDLE_BUS_OWNER:
+ if (handle->bus_owner) {
+ kdbus_node_deactivate(&handle->bus_owner->node);
+ kdbus_bus_unref(handle->bus_owner);
+ }
+ break;
+ case KDBUS_HANDLE_EP_OWNER:
+ if (handle->ep_owner) {
+ kdbus_node_deactivate(&handle->ep_owner->node);
+ kdbus_ep_unref(handle->ep_owner);
+ }
+ break;
+ case KDBUS_HANDLE_CONNECTED:
+ kdbus_conn_disconnect(handle->conn, false);
+ kdbus_conn_unref(handle->conn);
+ break;
+ case KDBUS_HANDLE_NONE:
+ /* nothing to clean up */
+ break;
+ }
+
+ kfree(handle);
+
+ return 0;
+}
+
+static long kdbus_handle_ioctl_control(struct file *file, unsigned int cmd,
+ void __user *argp)
+{
+ struct kdbus_handle *handle = file->private_data;
+ struct kdbus_node *node = file_inode(file)->i_private;
+ struct kdbus_domain *domain;
+ int ret = 0;
+
+ if (!kdbus_node_acquire(node))
+ return -ESHUTDOWN;
+
+ /*
+ * The parent of control-nodes is always a domain, make sure to pin it
+ * so the parent is actually valid.
+ */
+ domain = kdbus_domain_from_node(node->parent);
+ if (!kdbus_node_acquire(&domain->node)) {
+ kdbus_node_release(node);
+ return -ESHUTDOWN;
+ }
+
+ switch (cmd) {
+ case KDBUS_CMD_BUS_MAKE: {
+ struct kdbus_bus *bus;
+
+ bus = kdbus_cmd_bus_make(domain, argp);
+ if (IS_ERR_OR_NULL(bus)) {
+ ret = PTR_ERR_OR_ZERO(bus);
+ break;
+ }
+
+ handle->bus_owner = bus;
+ ret = KDBUS_HANDLE_BUS_OWNER;
+ break;
+ }
+
+ default:
+ ret = -EBADFD;
+ break;
+ }
+
+ kdbus_node_release(&domain->node);
+ kdbus_node_release(node);
+ return ret;
+}
+
+static long kdbus_handle_ioctl_ep(struct file *file, unsigned int cmd,
+ void __user *buf)
+{
+ struct kdbus_handle *handle = file->private_data;
+ struct kdbus_node *node = file_inode(file)->i_private;
+ struct kdbus_ep *ep, *file_ep = kdbus_ep_from_node(node);
+ struct kdbus_bus *bus = file_ep->bus;
+ struct kdbus_conn *conn;
+ int ret = 0;
+
+ if (!kdbus_node_acquire(node))
+ return -ESHUTDOWN;
+
+ switch (cmd) {
+ case KDBUS_CMD_ENDPOINT_MAKE: {
+ /* creating custom endpoints is a privileged operation */
+ if (!kdbus_ep_is_owner(file_ep, file)) {
+ ret = -EPERM;
+ break;
+ }
+
+ ep = kdbus_cmd_ep_make(bus, buf);
+ if (IS_ERR_OR_NULL(ep)) {
+ ret = PTR_ERR_OR_ZERO(ep);
+ break;
+ }
+
+ handle->ep_owner = ep;
+ ret = KDBUS_HANDLE_EP_OWNER;
+ break;
+ }
+
+ case KDBUS_CMD_HELLO:
+ conn = kdbus_cmd_hello(file_ep, file, buf);
+ if (IS_ERR_OR_NULL(conn)) {
+ ret = PTR_ERR_OR_ZERO(conn);
+ break;
+ }
+
+ handle->conn = conn;
+ ret = KDBUS_HANDLE_CONNECTED;
+ break;
+
+ default:
+ ret = -EBADFD;
+ break;
+ }
+
+ kdbus_node_release(node);
+ return ret;
+}
+
+static long kdbus_handle_ioctl_ep_owner(struct file *file, unsigned int command,
+ void __user *buf)
+{
+ struct kdbus_handle *handle = file->private_data;
+ struct kdbus_ep *ep = handle->ep_owner;
+ int ret;
+
+ if (!kdbus_node_acquire(&ep->node))
+ return -ESHUTDOWN;
+
+ switch (command) {
+ case KDBUS_CMD_ENDPOINT_UPDATE:
+ ret = kdbus_cmd_ep_update(ep, buf);
+ break;
+ default:
+ ret = -EBADFD;
+ break;
+ }
+
+ kdbus_node_release(&ep->node);
+ return ret;
+}
+
+static long kdbus_handle_ioctl_connected(struct file *file,
+ unsigned int command, void __user *buf)
+{
+ struct kdbus_handle *handle = file->private_data;
+ struct kdbus_conn *conn = handle->conn;
+ struct kdbus_conn *release_conn = NULL;
+ int ret;
+
+ release_conn = conn;
+ ret = kdbus_conn_acquire(release_conn);
+ if (ret < 0)
+ return ret;
+
+ switch (command) {
+ case KDBUS_CMD_BYEBYE:
+ /*
+ * BYEBYE is special; we must not acquire a connection when
+ * calling into kdbus_conn_disconnect() or we will deadlock,
+ * because kdbus_conn_disconnect() will wait for all acquired
+ * references to be dropped.
+ */
+ kdbus_conn_release(release_conn);
+ release_conn = NULL;
+ ret = kdbus_cmd_byebye_unlocked(conn, buf);
+ break;
+ case KDBUS_CMD_NAME_ACQUIRE:
+ ret = kdbus_cmd_name_acquire(conn, buf);
+ break;
+ case KDBUS_CMD_NAME_RELEASE:
+ ret = kdbus_cmd_name_release(conn, buf);
+ break;
+ case KDBUS_CMD_LIST:
+ ret = kdbus_cmd_list(conn, buf);
+ break;
+ case KDBUS_CMD_CONN_INFO:
+ ret = kdbus_cmd_conn_info(conn, buf);
+ break;
+ case KDBUS_CMD_BUS_CREATOR_INFO:
+ ret = kdbus_cmd_bus_creator_info(conn, buf);
+ break;
+ case KDBUS_CMD_UPDATE:
+ ret = kdbus_cmd_update(conn, buf);
+ break;
+ case KDBUS_CMD_MATCH_ADD:
+ ret = kdbus_cmd_match_add(conn, buf);
+ break;
+ case KDBUS_CMD_MATCH_REMOVE:
+ ret = kdbus_cmd_match_remove(conn, buf);
+ break;
+ case KDBUS_CMD_SEND:
+ ret = kdbus_cmd_send(conn, file, buf);
+ break;
+ case KDBUS_CMD_RECV:
+ ret = kdbus_cmd_recv(conn, buf);
+ break;
+ case KDBUS_CMD_FREE:
+ ret = kdbus_cmd_free(conn, buf);
+ break;
+ default:
+ ret = -EBADFD;
+ break;
+ }
+
+ kdbus_conn_release(release_conn);
+ return ret;
+}
+
+static long kdbus_handle_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct kdbus_handle *handle = file->private_data;
+ struct kdbus_node *node = kdbus_node_from_inode(file_inode(file));
+ void __user *argp = (void __user *)arg;
+ long ret = -EBADFD;
+
+ switch (cmd) {
+ case KDBUS_CMD_BUS_MAKE:
+ case KDBUS_CMD_ENDPOINT_MAKE:
+ case KDBUS_CMD_HELLO:
+ mutex_lock(&handle->lock);
+ if (handle->type == KDBUS_HANDLE_NONE) {
+ if (node->type == KDBUS_NODE_CONTROL)
+ ret = kdbus_handle_ioctl_control(file, cmd,
+ argp);
+ else if (node->type == KDBUS_NODE_ENDPOINT)
+ ret = kdbus_handle_ioctl_ep(file, cmd, argp);
+
+ if (ret > 0) {
+ /*
+ * The data given via open() is not sufficient
+ * to setup a kdbus handle. Hence, we require
+ * the user to perform a setup ioctl. This setup
+ * can only be performed once and defines the
+ * type of the handle. The different setup
+ * ioctls are locked against each other so they
+ * cannot race. Once the handle type is set,
+ * the type-dependent ioctls are enabled. To
+ * improve performance, we don't lock those via
+ * handle->lock. Instead, we issue a
+ * write-barrier before performing the
+ * type-change, which pairs with smp_rmb() in
+ * all handlers that access the type field. This
+ * guarantees the handle is fully setup, if
+ * handle->type is set. If handle->type is
+ * unset, you must not make any assumptions
+ * without taking handle->lock.
+ * Note that handle->type is only set once. It
+ * will never change afterwards.
+ */
+ smp_wmb();
+ handle->type = ret;
+ }
+ }
+ mutex_unlock(&handle->lock);
+ break;
+
+ case KDBUS_CMD_ENDPOINT_UPDATE:
+ case KDBUS_CMD_BYEBYE:
+ case KDBUS_CMD_NAME_ACQUIRE:
+ case KDBUS_CMD_NAME_RELEASE:
+ case KDBUS_CMD_LIST:
+ case KDBUS_CMD_CONN_INFO:
+ case KDBUS_CMD_BUS_CREATOR_INFO:
+ case KDBUS_CMD_UPDATE:
+ case KDBUS_CMD_MATCH_ADD:
+ case KDBUS_CMD_MATCH_REMOVE:
+ case KDBUS_CMD_SEND:
+ case KDBUS_CMD_RECV:
+ case KDBUS_CMD_FREE: {
+ enum kdbus_handle_type type;
+
+ /*
+ * This read-barrier pairs with smp_wmb() of the handle setup.
+ * it guarantees the handle is fully written, in case the
+ * type has been set. It allows us to access the handle without
+ * taking handle->lock, given the guarantee that the type is
+ * only ever set once, and stays constant afterwards.
+ * Furthermore, the handle object itself is not modified in any
+ * way after the type is set. That is, the type-field is the
+ * last field that is written on any handle. If it has not been
+ * set, we must not access the handle here.
+ */
+ type = handle->type;
+ smp_rmb();
+
+ if (type == KDBUS_HANDLE_EP_OWNER)
+ ret = kdbus_handle_ioctl_ep_owner(file, cmd, argp);
+ else if (type == KDBUS_HANDLE_CONNECTED)
+ ret = kdbus_handle_ioctl_connected(file, cmd, argp);
+
+ break;
+ }
+ default:
+ ret = -ENOTTY;
+ break;
+ }
+
+ return ret < 0 ? ret : 0;
+}
+
+static unsigned int kdbus_handle_poll(struct file *file,
+ struct poll_table_struct *wait)
+{
+ struct kdbus_handle *handle = file->private_data;
+ enum kdbus_handle_type type;
+ unsigned int mask = POLLOUT | POLLWRNORM;
+
+ /*
+ * This pairs with smp_wmb() during handle setup. It guarantees that
+ * _iff_ the handle type is set, handle->conn is valid. Furthermore,
+ * _iff_ the type is set, the handle object is constant and never
+ * changed again. If it's not set, we must not access the handle but
+ * bail out. We also must assume no setup has taken place, yet.
+ */
+ type = handle->type;
+ smp_rmb();
+
+ /* Only a connected endpoint can read/write data */
+ if (type != KDBUS_HANDLE_CONNECTED)
+ return POLLERR | POLLHUP;
+
+ poll_wait(file, &handle->conn->wait, wait);
+
+ /*
+ * Verify the connection hasn't been deactivated _after_ adding the
+ * wait-queue. This guarantees, that if the connection is deactivated
+ * after we checked it, the waitqueue is signaled and we're called
+ * again.
+ */
+ if (!kdbus_conn_active(handle->conn))
+ return POLLERR | POLLHUP;
+
+ if (!list_empty(&handle->conn->queue.msg_list) ||
+ atomic_read(&handle->conn->lost_count) > 0)
+ mask |= POLLIN | POLLRDNORM;
+
+ return mask;
+}
+
+static int kdbus_handle_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct kdbus_handle *handle = file->private_data;
+ enum kdbus_handle_type type;
+ int ret = -EBADFD;
+
+ /*
+ * This pairs with smp_wmb() during handle setup. It guarantees that
+ * _iff_ the handle type is set, handle->conn is valid. Furthermore,
+ * _iff_ the type is set, the handle object is constant and never
+ * changed again. If it's not set, we must not access the handle but
+ * bail out. We also must assume no setup has taken place, yet.
+ */
+ type = handle->type;
+ smp_rmb();
+
+ /* Only connected handles have a pool we can map */
+ if (type == KDBUS_HANDLE_CONNECTED)
+ ret = kdbus_pool_mmap(handle->conn->pool, vma);
+
+ return ret;
+}
+
+const struct file_operations kdbus_handle_ops = {
+ .owner = THIS_MODULE,
+ .open = kdbus_handle_open,
+ .release = kdbus_handle_release,
+ .poll = kdbus_handle_poll,
+ .llseek = noop_llseek,
+ .unlocked_ioctl = kdbus_handle_ioctl,
+ .mmap = kdbus_handle_mmap,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = kdbus_handle_ioctl,
+#endif
+};
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_HANDLE_H
+#define __KDBUS_HANDLE_H
+
+#include <linux/fs.h>
+#include <uapi/linux/kdbus.h>
+
+extern const struct file_operations kdbus_handle_ops;
+
+/**
+ * kdbus_arg - information and state of a single ioctl command item
+ * @type: item type
+ * @item: set by the parser to the first found item of this type
+ * @multiple: whether multiple items of this type are allowed
+ * @mandatory: whether at least one item of this type is required
+ *
+ * This structure describes a single item in an ioctl command payload. The
+ * caller has to pre-fill the type and flags, the parser will then use this
+ * information to verify the ioctl payload. @item is set by the parser to point
+ * to the first occurrence of the item.
+ */
+struct kdbus_arg {
+ u64 type;
+ struct kdbus_item *item;
+ bool multiple : 1;
+ bool mandatory : 1;
+};
+
+/**
+ * kdbus_args - information and state of ioctl command parser
+ * @allowed_flags: set of flags this command supports
+ * @argc: number of items in @argv
+ * @argv: array of items this command supports
+ * @user: set by parser to user-space location of current command
+ * @cmd: set by parser to kernel copy of command payload
+ * @cmd_buf: inline buf to avoid kmalloc() on small cmds
+ * @items: points to item array in @cmd
+ * @items_size: size of @items in bytes
+ * @is_cmd: whether this is a command-payload or msg-payload
+ *
+ * This structure is used to parse ioctl command payloads on each invocation.
+ * The ioctl handler has to pre-fill the flags and allowed items before passing
+ * the object to kdbus_args_parse(). The parser will copy the command payload
+ * into kernel-space and verify the correctness of the data.
+ *
+ * We use a 256 bytes buffer for small command payloads, to be allocated on
+ * stack on syscall entrance.
+ */
+struct kdbus_args {
+ u64 allowed_flags;
+ size_t argc;
+ struct kdbus_arg *argv;
+
+ struct kdbus_cmd __user *user;
+ struct kdbus_cmd *cmd;
+ u8 cmd_buf[256];
+
+ struct kdbus_item *items;
+ size_t items_size;
+ bool is_cmd : 1;
+};
+
+int __kdbus_args_parse(struct kdbus_args *args, bool is_cmd, void __user *argp,
+ size_t type_size, size_t items_offset, void **out);
+int kdbus_args_clear(struct kdbus_args *args, int ret);
+
+#define kdbus_args_parse(_args, _argp, _v) \
+ ({ \
+ BUILD_BUG_ON(offsetof(typeof(**(_v)), size) != \
+ offsetof(struct kdbus_cmd, size)); \
+ BUILD_BUG_ON(offsetof(typeof(**(_v)), flags) != \
+ offsetof(struct kdbus_cmd, flags)); \
+ BUILD_BUG_ON(offsetof(typeof(**(_v)), return_flags) != \
+ offsetof(struct kdbus_cmd, return_flags)); \
+ __kdbus_args_parse((_args), 1, (_argp), sizeof(**(_v)), \
+ offsetof(typeof(**(_v)), items), \
+ (void **)(_v)); \
+ })
+
+#define kdbus_args_parse_msg(_args, _argp, _v) \
+ ({ \
+ BUILD_BUG_ON(offsetof(typeof(**(_v)), size) != \
+ offsetof(struct kdbus_cmd, size)); \
+ BUILD_BUG_ON(offsetof(typeof(**(_v)), flags) != \
+ offsetof(struct kdbus_cmd, flags)); \
+ __kdbus_args_parse((_args), 0, (_argp), sizeof(**(_v)), \
+ offsetof(typeof(**(_v)), items), \
+ (void **)(_v)); \
+ })
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/ctype.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+
+#include "item.h"
+#include "limits.h"
+#include "util.h"
+
+/*
+ * This verifies the string at position @str with size @size is properly
+ * zero-terminated and does not contain a 0-byte but at the end.
+ */
+static bool kdbus_str_valid(const char *str, size_t size)
+{
+ return size > 0 && memchr(str, '\0', size) == str + size - 1;
+}
+
+/**
+ * kdbus_item_validate_name() - validate an item containing a name
+ * @item: Item to validate
+ *
+ * Return: zero on success or an negative error code on failure
+ */
+int kdbus_item_validate_name(const struct kdbus_item *item)
+{
+ const char *name = item->str;
+ unsigned int i;
+ size_t len;
+
+ if (item->size < KDBUS_ITEM_HEADER_SIZE + 2)
+ return -EINVAL;
+
+ if (item->size > KDBUS_ITEM_HEADER_SIZE +
+ KDBUS_SYSNAME_MAX_LEN + 1)
+ return -ENAMETOOLONG;
+
+ if (!kdbus_str_valid(name, KDBUS_ITEM_PAYLOAD_SIZE(item)))
+ return -EINVAL;
+
+ len = strlen(name);
+ if (len == 0)
+ return -EINVAL;
+
+ for (i = 0; i < len; i++) {
+ if (isalpha(name[i]))
+ continue;
+ if (isdigit(name[i]))
+ continue;
+ if (name[i] == '_')
+ continue;
+ if (i > 0 && i + 1 < len && (name[i] == '-' || name[i] == '.'))
+ continue;
+
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * kdbus_item_validate() - validate a single item
+ * @item: item to validate
+ *
+ * Return: 0 if item is valid, negative error code if not.
+ */
+int kdbus_item_validate(const struct kdbus_item *item)
+{
+ size_t payload_size = KDBUS_ITEM_PAYLOAD_SIZE(item);
+ size_t l;
+ int ret;
+
+ BUILD_BUG_ON(KDBUS_ITEM_HEADER_SIZE !=
+ sizeof(struct kdbus_item_header));
+
+ if (item->size < KDBUS_ITEM_HEADER_SIZE)
+ return -EINVAL;
+
+ switch (item->type) {
+ case KDBUS_ITEM_NEGOTIATE:
+ if (payload_size % sizeof(u64) != 0)
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_PAYLOAD_VEC:
+ case KDBUS_ITEM_PAYLOAD_OFF:
+ if (payload_size != sizeof(struct kdbus_vec))
+ return -EINVAL;
+ if (item->vec.size == 0 || item->vec.size > SIZE_MAX)
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_PAYLOAD_MEMFD:
+ if (payload_size != sizeof(struct kdbus_memfd))
+ return -EINVAL;
+ if (item->memfd.size == 0 || item->memfd.size > SIZE_MAX)
+ return -EINVAL;
+ if (item->memfd.fd < 0)
+ return -EBADF;
+ break;
+
+ case KDBUS_ITEM_FDS:
+ if (payload_size % sizeof(int) != 0)
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_CANCEL_FD:
+ if (payload_size != sizeof(int))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_BLOOM_PARAMETER:
+ if (payload_size != sizeof(struct kdbus_bloom_parameter))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_BLOOM_FILTER:
+ /* followed by the bloom-mask, depends on the bloom-size */
+ if (payload_size < sizeof(struct kdbus_bloom_filter))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_BLOOM_MASK:
+ /* size depends on bloom-size of bus */
+ break;
+
+ case KDBUS_ITEM_CONN_DESCRIPTION:
+ case KDBUS_ITEM_MAKE_NAME:
+ ret = kdbus_item_validate_name(item);
+ if (ret < 0)
+ return ret;
+ break;
+
+ case KDBUS_ITEM_ATTACH_FLAGS_SEND:
+ case KDBUS_ITEM_ATTACH_FLAGS_RECV:
+ case KDBUS_ITEM_ID:
+ case KDBUS_ITEM_DST_ID:
+ if (payload_size != sizeof(u64))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_TIMESTAMP:
+ if (payload_size != sizeof(struct kdbus_timestamp))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_CREDS:
+ if (payload_size != sizeof(struct kdbus_creds))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_AUXGROUPS:
+ if (payload_size % sizeof(u32) != 0)
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_NAME:
+ case KDBUS_ITEM_DST_NAME:
+ case KDBUS_ITEM_PID_COMM:
+ case KDBUS_ITEM_TID_COMM:
+ case KDBUS_ITEM_EXE:
+ case KDBUS_ITEM_CMDLINE:
+ case KDBUS_ITEM_CGROUP:
+ case KDBUS_ITEM_SECLABEL:
+ if (!kdbus_str_valid(item->str, payload_size))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_CAPS:
+ if (payload_size < sizeof(u32))
+ return -EINVAL;
+ if (payload_size < sizeof(u32) +
+ 4 * CAP_TO_INDEX(item->caps.last_cap) * sizeof(u32))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_AUDIT:
+ if (payload_size != sizeof(struct kdbus_audit))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_POLICY_ACCESS:
+ if (payload_size != sizeof(struct kdbus_policy_access))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_NAME_ADD:
+ case KDBUS_ITEM_NAME_REMOVE:
+ case KDBUS_ITEM_NAME_CHANGE:
+ if (payload_size < sizeof(struct kdbus_notify_name_change))
+ return -EINVAL;
+ l = payload_size - offsetof(struct kdbus_notify_name_change,
+ name);
+ if (l > 0 && !kdbus_str_valid(item->name_change.name, l))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_ID_ADD:
+ case KDBUS_ITEM_ID_REMOVE:
+ if (payload_size != sizeof(struct kdbus_notify_id_change))
+ return -EINVAL;
+ break;
+
+ case KDBUS_ITEM_REPLY_TIMEOUT:
+ case KDBUS_ITEM_REPLY_DEAD:
+ if (payload_size != 0)
+ return -EINVAL;
+ break;
+
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+/**
+ * kdbus_items_validate() - validate items passed by user-space
+ * @items: items to validate
+ * @items_size: number of items
+ *
+ * This verifies that the passed items pointer is consistent and valid.
+ * Furthermore, each item is checked for:
+ * - valid "size" value
+ * - payload is of expected type
+ * - payload is fully included in the item
+ * - string payloads are zero-terminated
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_items_validate(const struct kdbus_item *items, size_t items_size)
+{
+ const struct kdbus_item *item;
+ int ret;
+
+ KDBUS_ITEMS_FOREACH(item, items, items_size) {
+ if (!KDBUS_ITEM_VALID(item, items, items_size))
+ return -EINVAL;
+
+ ret = kdbus_item_validate(item);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (!KDBUS_ITEMS_END(item, items, items_size))
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * kdbus_item_set() - Set item content
+ * @item: The item to modify
+ * @type: The item type to set (KDBUS_ITEM_*)
+ * @data: Data to copy to item->data, may be %NULL
+ * @len: Number of bytes in @data
+ *
+ * This sets type, size and data fields of an item. If @data is NULL, the data
+ * memory is cleared.
+ *
+ * Note that you must align your @data memory to 8 bytes. Trailing padding (in
+ * case @len is not 8byte aligned) is cleared by this call.
+ *
+ * Returns: Pointer to the following item.
+ */
+struct kdbus_item *kdbus_item_set(struct kdbus_item *item, u64 type,
+ const void *data, size_t len)
+{
+ item->type = type;
+ item->size = KDBUS_ITEM_HEADER_SIZE + len;
+
+ if (data) {
+ memcpy(item->data, data, len);
+ memset(item->data + len, 0, KDBUS_ALIGN8(len) - len);
+ } else {
+ memset(item->data, 0, KDBUS_ALIGN8(len));
+ }
+
+ return KDBUS_ITEM_NEXT(item);
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_ITEM_H
+#define __KDBUS_ITEM_H
+
+#include <linux/kernel.h>
+#include <uapi/linux/kdbus.h>
+
+#include "util.h"
+
+/* generic access and iterators over a stream of items */
+#define KDBUS_ITEM_NEXT(_i) (typeof(_i))((u8 *)(_i) + KDBUS_ALIGN8((_i)->size))
+#define KDBUS_ITEMS_SIZE(_h, _is) ((_h)->size - offsetof(typeof(*(_h)), _is))
+#define KDBUS_ITEM_HEADER_SIZE offsetof(struct kdbus_item, data)
+#define KDBUS_ITEM_SIZE(_s) KDBUS_ALIGN8(KDBUS_ITEM_HEADER_SIZE + (_s))
+#define KDBUS_ITEM_PAYLOAD_SIZE(_i) ((_i)->size - KDBUS_ITEM_HEADER_SIZE)
+
+#define KDBUS_ITEMS_FOREACH(_i, _is, _s) \
+ for ((_i) = (_is); \
+ ((u8 *)(_i) < (u8 *)(_is) + (_s)) && \
+ ((u8 *)(_i) >= (u8 *)(_is)); \
+ (_i) = KDBUS_ITEM_NEXT(_i))
+
+#define KDBUS_ITEM_VALID(_i, _is, _s) \
+ ((_i)->size >= KDBUS_ITEM_HEADER_SIZE && \
+ (u8 *)(_i) + (_i)->size > (u8 *)(_i) && \
+ (u8 *)(_i) + (_i)->size <= (u8 *)(_is) + (_s) && \
+ (u8 *)(_i) >= (u8 *)(_is))
+
+#define KDBUS_ITEMS_END(_i, _is, _s) \
+ ((u8 *)(_i) == ((u8 *)(_is) + KDBUS_ALIGN8(_s)))
+
+/**
+ * struct kdbus_item_header - Describes the fix part of an item
+ * @size: The total size of the item
+ * @type: The item type, one of KDBUS_ITEM_*
+ */
+struct kdbus_item_header {
+ u64 size;
+ u64 type;
+};
+
+int kdbus_item_validate_name(const struct kdbus_item *item);
+int kdbus_item_validate(const struct kdbus_item *item);
+int kdbus_items_validate(const struct kdbus_item *items, size_t items_size);
+struct kdbus_item *kdbus_item_set(struct kdbus_item *item, u64 type,
+ const void *data, size_t len);
+
+#endif
--- /dev/null
+/*
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef _UAPI_KDBUS_H_
+#define _UAPI_KDBUS_H_
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+#define KDBUS_IOCTL_MAGIC 0x95
+#define KDBUS_SRC_ID_KERNEL (0)
+#define KDBUS_DST_ID_NAME (0)
+#define KDBUS_MATCH_ID_ANY (~0ULL)
+#define KDBUS_DST_ID_BROADCAST (~0ULL)
+#define KDBUS_FLAG_NEGOTIATE (1ULL << 63)
+
+/**
+ * struct kdbus_notify_id_change - name registry change message
+ * @id: New or former owner of the name
+ * @flags: flags field from KDBUS_HELLO_*
+ *
+ * Sent from kernel to userspace when the owner or activator of
+ * a well-known name changes.
+ *
+ * Attached to:
+ * KDBUS_ITEM_ID_ADD
+ * KDBUS_ITEM_ID_REMOVE
+ */
+struct kdbus_notify_id_change {
+ __u64 id;
+ __u64 flags;
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_notify_name_change - name registry change message
+ * @old_id: ID and flags of former owner of a name
+ * @new_id: ID and flags of new owner of a name
+ * @name: Well-known name
+ *
+ * Sent from kernel to userspace when the owner or activator of
+ * a well-known name changes.
+ *
+ * Attached to:
+ * KDBUS_ITEM_NAME_ADD
+ * KDBUS_ITEM_NAME_REMOVE
+ * KDBUS_ITEM_NAME_CHANGE
+ */
+struct kdbus_notify_name_change {
+ struct kdbus_notify_id_change old_id;
+ struct kdbus_notify_id_change new_id;
+ char name[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_creds - process credentials
+ * @uid: User ID
+ * @euid: Effective UID
+ * @suid: Saved UID
+ * @fsuid: Filesystem UID
+ * @gid: Group ID
+ * @egid: Effective GID
+ * @sgid: Saved GID
+ * @fsgid: Filesystem GID
+ *
+ * Attached to:
+ * KDBUS_ITEM_CREDS
+ */
+struct kdbus_creds {
+ __u64 uid;
+ __u64 euid;
+ __u64 suid;
+ __u64 fsuid;
+ __u64 gid;
+ __u64 egid;
+ __u64 sgid;
+ __u64 fsgid;
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_pids - process identifiers
+ * @pid: Process ID
+ * @tid: Thread ID
+ * @ppid: Parent process ID
+ *
+ * The PID and TID of a process.
+ *
+ * Attached to:
+ * KDBUS_ITEM_PIDS
+ */
+struct kdbus_pids {
+ __u64 pid;
+ __u64 tid;
+ __u64 ppid;
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_caps - process capabilities
+ * @last_cap: Highest currently known capability bit
+ * @caps: Variable number of 32-bit capabilities flags
+ *
+ * Contains a variable number of 32-bit capabilities flags.
+ *
+ * Attached to:
+ * KDBUS_ITEM_CAPS
+ */
+struct kdbus_caps {
+ __u32 last_cap;
+ __u32 caps[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_audit - audit information
+ * @sessionid: The audit session ID
+ * @loginuid: The audit login uid
+ *
+ * Attached to:
+ * KDBUS_ITEM_AUDIT
+ */
+struct kdbus_audit {
+ __u32 sessionid;
+ __u32 loginuid;
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_timestamp
+ * @seqnum: Global per-domain message sequence number
+ * @monotonic_ns: Monotonic timestamp, in nanoseconds
+ * @realtime_ns: Realtime timestamp, in nanoseconds
+ *
+ * Attached to:
+ * KDBUS_ITEM_TIMESTAMP
+ */
+struct kdbus_timestamp {
+ __u64 seqnum;
+ __u64 monotonic_ns;
+ __u64 realtime_ns;
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_vec - I/O vector for kdbus payload items
+ * @size: The size of the vector
+ * @address: Memory address of data buffer
+ * @offset: Offset in the in-message payload memory,
+ * relative to the message head
+ *
+ * Attached to:
+ * KDBUS_ITEM_PAYLOAD_VEC, KDBUS_ITEM_PAYLOAD_OFF
+ */
+struct kdbus_vec {
+ __u64 size;
+ union {
+ __u64 address;
+ __u64 offset;
+ };
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_bloom_parameter - bus-wide bloom parameters
+ * @size: Size of the bit field in bytes (m / 8)
+ * @n_hash: Number of hash functions used (k)
+ */
+struct kdbus_bloom_parameter {
+ __u64 size;
+ __u64 n_hash;
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_bloom_filter - bloom filter containing n elements
+ * @generation: Generation of the element set in the filter
+ * @data: Bit field, multiple of 8 bytes
+ */
+struct kdbus_bloom_filter {
+ __u64 generation;
+ __u64 data[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_memfd - a kdbus memfd
+ * @start: The offset into the memfd where the segment starts
+ * @size: The size of the memfd segment
+ * @fd: The file descriptor number
+ * @__pad: Padding to ensure proper alignment and size
+ *
+ * Attached to:
+ * KDBUS_ITEM_PAYLOAD_MEMFD
+ */
+struct kdbus_memfd {
+ __u64 start;
+ __u64 size;
+ int fd;
+ __u32 __pad;
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_name - a registered well-known name with its flags
+ * @flags: Flags from KDBUS_NAME_*
+ * @name: Well-known name
+ *
+ * Attached to:
+ * KDBUS_ITEM_OWNED_NAME
+ */
+struct kdbus_name {
+ __u64 flags;
+ char name[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * enum kdbus_policy_access_type - permissions of a policy record
+ * @_KDBUS_POLICY_ACCESS_NULL: Uninitialized/invalid
+ * @KDBUS_POLICY_ACCESS_USER: Grant access to a uid
+ * @KDBUS_POLICY_ACCESS_GROUP: Grant access to gid
+ * @KDBUS_POLICY_ACCESS_WORLD: World-accessible
+ */
+enum kdbus_policy_access_type {
+ _KDBUS_POLICY_ACCESS_NULL,
+ KDBUS_POLICY_ACCESS_USER,
+ KDBUS_POLICY_ACCESS_GROUP,
+ KDBUS_POLICY_ACCESS_WORLD,
+};
+
+/**
+ * enum kdbus_policy_access_flags - mode flags
+ * @KDBUS_POLICY_OWN: Allow to own a well-known name
+ * Implies KDBUS_POLICY_TALK and KDBUS_POLICY_SEE
+ * @KDBUS_POLICY_TALK: Allow communication to a well-known name
+ * Implies KDBUS_POLICY_SEE
+ * @KDBUS_POLICY_SEE: Allow to see a well-known name
+ */
+enum kdbus_policy_type {
+ KDBUS_POLICY_SEE = 0,
+ KDBUS_POLICY_TALK,
+ KDBUS_POLICY_OWN,
+};
+
+/**
+ * struct kdbus_policy_access - policy access item
+ * @type: One of KDBUS_POLICY_ACCESS_* types
+ * @access: Access to grant
+ * @id: For KDBUS_POLICY_ACCESS_USER, the uid
+ * For KDBUS_POLICY_ACCESS_GROUP, the gid
+ */
+struct kdbus_policy_access {
+ __u64 type; /* USER, GROUP, WORLD */
+ __u64 access; /* OWN, TALK, SEE */
+ __u64 id; /* uid, gid, 0 */
+} __attribute__((__aligned__(8)));
+
+/**
+ * enum kdbus_attach_flags - flags for metadata attachments
+ * @KDBUS_ATTACH_TIMESTAMP: Timestamp
+ * @KDBUS_ATTACH_CREDS: Credentials
+ * @KDBUS_ATTACH_PIDS: PIDs
+ * @KDBUS_ATTACH_AUXGROUPS: Auxiliary groups
+ * @KDBUS_ATTACH_NAMES: Well-known names
+ * @KDBUS_ATTACH_TID_COMM: The "comm" process identifier of the TID
+ * @KDBUS_ATTACH_PID_COMM: The "comm" process identifier of the PID
+ * @KDBUS_ATTACH_EXE: The path of the executable
+ * @KDBUS_ATTACH_CMDLINE: The process command line
+ * @KDBUS_ATTACH_CGROUP: The croup membership
+ * @KDBUS_ATTACH_CAPS: The process capabilities
+ * @KDBUS_ATTACH_SECLABEL: The security label
+ * @KDBUS_ATTACH_AUDIT: The audit IDs
+ * @KDBUS_ATTACH_CONN_DESCRIPTION: The human-readable connection name
+ * @_KDBUS_ATTACH_ALL: All of the above
+ * @_KDBUS_ATTACH_ANY: Wildcard match to enable any kind of
+ * metatdata.
+ */
+enum kdbus_attach_flags {
+ KDBUS_ATTACH_TIMESTAMP = 1ULL << 0,
+ KDBUS_ATTACH_CREDS = 1ULL << 1,
+ KDBUS_ATTACH_PIDS = 1ULL << 2,
+ KDBUS_ATTACH_AUXGROUPS = 1ULL << 3,
+ KDBUS_ATTACH_NAMES = 1ULL << 4,
+ KDBUS_ATTACH_TID_COMM = 1ULL << 5,
+ KDBUS_ATTACH_PID_COMM = 1ULL << 6,
+ KDBUS_ATTACH_EXE = 1ULL << 7,
+ KDBUS_ATTACH_CMDLINE = 1ULL << 8,
+ KDBUS_ATTACH_CGROUP = 1ULL << 9,
+ KDBUS_ATTACH_CAPS = 1ULL << 10,
+ KDBUS_ATTACH_SECLABEL = 1ULL << 11,
+ KDBUS_ATTACH_AUDIT = 1ULL << 12,
+ KDBUS_ATTACH_CONN_DESCRIPTION = 1ULL << 13,
+ _KDBUS_ATTACH_ALL = (1ULL << 14) - 1,
+ _KDBUS_ATTACH_ANY = ~0ULL
+};
+
+/**
+ * enum kdbus_item_type - item types to chain data in a list
+ * @_KDBUS_ITEM_NULL: Uninitialized/invalid
+ * @_KDBUS_ITEM_USER_BASE: Start of user items
+ * @KDBUS_ITEM_NEGOTIATE: Negotiate supported items
+ * @KDBUS_ITEM_PAYLOAD_VEC: Vector to data
+ * @KDBUS_ITEM_PAYLOAD_OFF: Data at returned offset to message head
+ * @KDBUS_ITEM_PAYLOAD_MEMFD: Data as sealed memfd
+ * @KDBUS_ITEM_FDS: Attached file descriptors
+ * @KDBUS_ITEM_CANCEL_FD: FD used to cancel a synchronous
+ * operation by writing to it from
+ * userspace
+ * @KDBUS_ITEM_BLOOM_PARAMETER: Bus-wide bloom parameters, used with
+ * KDBUS_CMD_BUS_MAKE, carries a
+ * struct kdbus_bloom_parameter
+ * @KDBUS_ITEM_BLOOM_FILTER: Bloom filter carried with a message,
+ * used to match against a bloom mask of a
+ * connection, carries a struct
+ * kdbus_bloom_filter
+ * @KDBUS_ITEM_BLOOM_MASK: Bloom mask used to match against a
+ * message'sbloom filter
+ * @KDBUS_ITEM_DST_NAME: Destination's well-known name
+ * @KDBUS_ITEM_MAKE_NAME: Name of domain, bus, endpoint
+ * @KDBUS_ITEM_ATTACH_FLAGS_SEND: Attach-flags, used for updating which
+ * metadata a connection opts in to send
+ * @KDBUS_ITEM_ATTACH_FLAGS_RECV: Attach-flags, used for updating which
+ * metadata a connection requests to
+ * receive for each reeceived message
+ * @KDBUS_ITEM_ID: Connection ID
+ * @KDBUS_ITEM_NAME: Well-know name with flags
+ * @_KDBUS_ITEM_ATTACH_BASE: Start of metadata attach items
+ * @KDBUS_ITEM_TIMESTAMP: Timestamp
+ * @KDBUS_ITEM_CREDS: Process credentials
+ * @KDBUS_ITEM_PIDS: Process identifiers
+ * @KDBUS_ITEM_AUXGROUPS: Auxiliary process groups
+ * @KDBUS_ITEM_OWNED_NAME: A name owned by the associated
+ * connection
+ * @KDBUS_ITEM_TID_COMM: Thread ID "comm" identifier
+ * (Don't trust this, see below.)
+ * @KDBUS_ITEM_PID_COMM: Process ID "comm" identifier
+ * (Don't trust this, see below.)
+ * @KDBUS_ITEM_EXE: The path of the executable
+ * (Don't trust this, see below.)
+ * @KDBUS_ITEM_CMDLINE: The process command line
+ * (Don't trust this, see below.)
+ * @KDBUS_ITEM_CGROUP: The croup membership
+ * @KDBUS_ITEM_CAPS: The process capabilities
+ * @KDBUS_ITEM_SECLABEL: The security label
+ * @KDBUS_ITEM_AUDIT: The audit IDs
+ * @KDBUS_ITEM_CONN_DESCRIPTION: The connection's human-readable name
+ * (debugging)
+ * @_KDBUS_ITEM_POLICY_BASE: Start of policy items
+ * @KDBUS_ITEM_POLICY_ACCESS: Policy access block
+ * @_KDBUS_ITEM_KERNEL_BASE: Start of kernel-generated message items
+ * @KDBUS_ITEM_NAME_ADD: Notification in kdbus_notify_name_change
+ * @KDBUS_ITEM_NAME_REMOVE: Notification in kdbus_notify_name_change
+ * @KDBUS_ITEM_NAME_CHANGE: Notification in kdbus_notify_name_change
+ * @KDBUS_ITEM_ID_ADD: Notification in kdbus_notify_id_change
+ * @KDBUS_ITEM_ID_REMOVE: Notification in kdbus_notify_id_change
+ * @KDBUS_ITEM_REPLY_TIMEOUT: Timeout has been reached
+ * @KDBUS_ITEM_REPLY_DEAD: Destination died
+ *
+ * N.B: The process and thread COMM fields, as well as the CMDLINE and
+ * EXE fields may be altered by unprivileged processes und should
+ * hence *not* used for security decisions. Peers should make use of
+ * these items only for informational purposes, such as generating log
+ * records.
+ */
+enum kdbus_item_type {
+ _KDBUS_ITEM_NULL,
+ _KDBUS_ITEM_USER_BASE,
+ KDBUS_ITEM_NEGOTIATE = _KDBUS_ITEM_USER_BASE,
+ KDBUS_ITEM_PAYLOAD_VEC,
+ KDBUS_ITEM_PAYLOAD_OFF,
+ KDBUS_ITEM_PAYLOAD_MEMFD,
+ KDBUS_ITEM_FDS,
+ KDBUS_ITEM_CANCEL_FD,
+ KDBUS_ITEM_BLOOM_PARAMETER,
+ KDBUS_ITEM_BLOOM_FILTER,
+ KDBUS_ITEM_BLOOM_MASK,
+ KDBUS_ITEM_DST_NAME,
+ KDBUS_ITEM_MAKE_NAME,
+ KDBUS_ITEM_ATTACH_FLAGS_SEND,
+ KDBUS_ITEM_ATTACH_FLAGS_RECV,
+ KDBUS_ITEM_ID,
+ KDBUS_ITEM_NAME,
+ KDBUS_ITEM_DST_ID,
+
+ /* keep these item types in sync with KDBUS_ATTACH_* flags */
+ _KDBUS_ITEM_ATTACH_BASE = 0x1000,
+ KDBUS_ITEM_TIMESTAMP = _KDBUS_ITEM_ATTACH_BASE,
+ KDBUS_ITEM_CREDS,
+ KDBUS_ITEM_PIDS,
+ KDBUS_ITEM_AUXGROUPS,
+ KDBUS_ITEM_OWNED_NAME,
+ KDBUS_ITEM_TID_COMM,
+ KDBUS_ITEM_PID_COMM,
+ KDBUS_ITEM_EXE,
+ KDBUS_ITEM_CMDLINE,
+ KDBUS_ITEM_CGROUP,
+ KDBUS_ITEM_CAPS,
+ KDBUS_ITEM_SECLABEL,
+ KDBUS_ITEM_AUDIT,
+ KDBUS_ITEM_CONN_DESCRIPTION,
+
+ _KDBUS_ITEM_POLICY_BASE = 0x2000,
+ KDBUS_ITEM_POLICY_ACCESS = _KDBUS_ITEM_POLICY_BASE,
+
+ _KDBUS_ITEM_KERNEL_BASE = 0x8000,
+ KDBUS_ITEM_NAME_ADD = _KDBUS_ITEM_KERNEL_BASE,
+ KDBUS_ITEM_NAME_REMOVE,
+ KDBUS_ITEM_NAME_CHANGE,
+ KDBUS_ITEM_ID_ADD,
+ KDBUS_ITEM_ID_REMOVE,
+ KDBUS_ITEM_REPLY_TIMEOUT,
+ KDBUS_ITEM_REPLY_DEAD,
+};
+
+/**
+ * struct kdbus_item - chain of data blocks
+ * @size: Overall data record size
+ * @type: Kdbus_item type of data
+ * @data: Generic bytes
+ * @data32: Generic 32 bit array
+ * @data64: Generic 64 bit array
+ * @str: Generic string
+ * @id: Connection ID
+ * @vec: KDBUS_ITEM_PAYLOAD_VEC
+ * @creds: KDBUS_ITEM_CREDS
+ * @audit: KDBUS_ITEM_AUDIT
+ * @timestamp: KDBUS_ITEM_TIMESTAMP
+ * @name: KDBUS_ITEM_NAME
+ * @bloom_parameter: KDBUS_ITEM_BLOOM_PARAMETER
+ * @bloom_filter: KDBUS_ITEM_BLOOM_FILTER
+ * @memfd: KDBUS_ITEM_PAYLOAD_MEMFD
+ * @name_change: KDBUS_ITEM_NAME_ADD
+ * KDBUS_ITEM_NAME_REMOVE
+ * KDBUS_ITEM_NAME_CHANGE
+ * @id_change: KDBUS_ITEM_ID_ADD
+ * KDBUS_ITEM_ID_REMOVE
+ * @policy: KDBUS_ITEM_POLICY_ACCESS
+ */
+struct kdbus_item {
+ __u64 size;
+ __u64 type;
+ union {
+ __u8 data[0];
+ __u32 data32[0];
+ __u64 data64[0];
+ char str[0];
+
+ __u64 id;
+ struct kdbus_vec vec;
+ struct kdbus_creds creds;
+ struct kdbus_pids pids;
+ struct kdbus_audit audit;
+ struct kdbus_caps caps;
+ struct kdbus_timestamp timestamp;
+ struct kdbus_name name;
+ struct kdbus_bloom_parameter bloom_parameter;
+ struct kdbus_bloom_filter bloom_filter;
+ struct kdbus_memfd memfd;
+ int fds[0];
+ struct kdbus_notify_name_change name_change;
+ struct kdbus_notify_id_change id_change;
+ struct kdbus_policy_access policy_access;
+ };
+} __attribute__((__aligned__(8)));
+
+/**
+ * enum kdbus_msg_flags - type of message
+ * @KDBUS_MSG_EXPECT_REPLY: Expect a reply message, used for
+ * method calls. The userspace-supplied
+ * cookie identifies the message and the
+ * respective reply carries the cookie
+ * in cookie_reply
+ * @KDBUS_MSG_NO_AUTO_START: Do not start a service if the addressed
+ * name is not currently active. This flag is
+ * not looked at by the kernel but only
+ * serves as hint for userspace implementations.
+ * @KDBUS_MSG_SIGNAL: Treat this message as signal
+ */
+enum kdbus_msg_flags {
+ KDBUS_MSG_EXPECT_REPLY = 1ULL << 0,
+ KDBUS_MSG_NO_AUTO_START = 1ULL << 1,
+ KDBUS_MSG_SIGNAL = 1ULL << 2,
+};
+
+/**
+ * enum kdbus_payload_type - type of payload carried by message
+ * @KDBUS_PAYLOAD_KERNEL: Kernel-generated simple message
+ * @KDBUS_PAYLOAD_DBUS: D-Bus marshalling "DBusDBus"
+ *
+ * Any payload-type is accepted. Common types will get added here once
+ * established.
+ */
+enum kdbus_payload_type {
+ KDBUS_PAYLOAD_KERNEL,
+ KDBUS_PAYLOAD_DBUS = 0x4442757344427573ULL,
+};
+
+/**
+ * struct kdbus_msg - the representation of a kdbus message
+ * @size: Total size of the message
+ * @flags: Message flags (KDBUS_MSG_*), userspace → kernel
+ * @priority: Message queue priority value
+ * @dst_id: 64-bit ID of the destination connection
+ * @src_id: 64-bit ID of the source connection
+ * @payload_type: Payload type (KDBUS_PAYLOAD_*)
+ * @cookie: Userspace-supplied cookie, for the connection
+ * to identify its messages
+ * @timeout_ns: The time to wait for a message reply from the peer.
+ * If there is no reply, and the send command is
+ * executed asynchronously, a kernel-generated message
+ * with an attached KDBUS_ITEM_REPLY_TIMEOUT item
+ * is sent to @src_id. For synchronously executed send
+ * command, the value denotes the maximum time the call
+ * blocks to wait for a reply. The timeout is expected in
+ * nanoseconds and as absolute CLOCK_MONOTONIC value.
+ * @cookie_reply: A reply to the requesting message with the same
+ * cookie. The requesting connection can match its
+ * request and the reply with this value
+ * @items: A list of kdbus_items containing the message payload
+ */
+struct kdbus_msg {
+ __u64 size;
+ __u64 flags;
+ __s64 priority;
+ __u64 dst_id;
+ __u64 src_id;
+ __u64 payload_type;
+ __u64 cookie;
+ union {
+ __u64 timeout_ns;
+ __u64 cookie_reply;
+ };
+ struct kdbus_item items[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_msg_info - returned message container
+ * @offset: Offset of kdbus_msg slice in pool
+ * @msg_size: Copy of the kdbus_msg.size field
+ * @return_flags: Command return flags, kernel → userspace
+ */
+struct kdbus_msg_info {
+ __u64 offset;
+ __u64 msg_size;
+ __u64 return_flags;
+} __attribute__((__aligned__(8)));
+
+/**
+ * enum kdbus_send_flags - flags for sending messages
+ * @KDBUS_SEND_SYNC_REPLY: Wait for destination connection to
+ * reply to this message. The
+ * KDBUS_CMD_SEND ioctl() will block
+ * until the reply is received, and
+ * reply in struct kdbus_cmd_send will
+ * yield the offset in the sender's pool
+ * where the reply can be found.
+ * This flag is only valid if
+ * @KDBUS_MSG_EXPECT_REPLY is set as well.
+ */
+enum kdbus_send_flags {
+ KDBUS_SEND_SYNC_REPLY = 1ULL << 0,
+};
+
+/**
+ * struct kdbus_cmd_send - send message
+ * @size: Overall size of this structure
+ * @flags: Flags to change send behavior (KDBUS_SEND_*)
+ * @return_flags: Command return flags, kernel → userspace
+ * @msg_address: Storage address of the kdbus_msg to send
+ * @reply: Storage for message reply if KDBUS_SEND_SYNC_REPLY
+ * was given
+ * @items: Additional items for this command
+ */
+struct kdbus_cmd_send {
+ __u64 size;
+ __u64 flags;
+ __u64 return_flags;
+ __u64 msg_address;
+ struct kdbus_msg_info reply;
+ struct kdbus_item items[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * enum kdbus_recv_flags - flags for de-queuing messages
+ * @KDBUS_RECV_PEEK: Return the next queued message without
+ * actually de-queuing it, and without installing
+ * any file descriptors or other resources. It is
+ * usually used to determine the activating
+ * connection of a bus name.
+ * @KDBUS_RECV_DROP: Drop and free the next queued message and all
+ * its resources without actually receiving it.
+ * @KDBUS_RECV_USE_PRIORITY: Only de-queue messages with the specified or
+ * higher priority (lowest values); if not set,
+ * the priority value is ignored.
+ */
+enum kdbus_recv_flags {
+ KDBUS_RECV_PEEK = 1ULL << 0,
+ KDBUS_RECV_DROP = 1ULL << 1,
+ KDBUS_RECV_USE_PRIORITY = 1ULL << 2,
+};
+
+/**
+ * enum kdbus_recv_return_flags - return flags for message receive commands
+ * @KDBUS_RECV_RETURN_INCOMPLETE_FDS: One or more file descriptors could not
+ * be installed. These descriptors in
+ * KDBUS_ITEM_FDS will carry the value -1.
+ * @KDBUS_RECV_RETURN_DROPPED_MSGS: There have been dropped messages since
+ * the last time a message was received.
+ * The 'dropped_msgs' counter contains the
+ * number of messages dropped pool
+ * overflows or other missed broadcasts.
+ */
+enum kdbus_recv_return_flags {
+ KDBUS_RECV_RETURN_INCOMPLETE_FDS = 1ULL << 0,
+ KDBUS_RECV_RETURN_DROPPED_MSGS = 1ULL << 1,
+};
+
+/**
+ * struct kdbus_cmd_recv - struct to de-queue a buffered message
+ * @size: Overall size of this object
+ * @flags: KDBUS_RECV_* flags, userspace → kernel
+ * @return_flags: Command return flags, kernel → userspace
+ * @priority: Minimum priority of the messages to de-queue. Lowest
+ * values have the highest priority.
+ * @dropped_msgs: In case there were any dropped messages since the last
+ * time a message was received, this will be set to the
+ * number of lost messages and
+ * KDBUS_RECV_RETURN_DROPPED_MSGS will be set in
+ * 'return_flags'. This can only happen if the ioctl
+ * returns 0 or EAGAIN.
+ * @msg: Return storage for received message.
+ * @items: Additional items for this command.
+ *
+ * This struct is used with the KDBUS_CMD_RECV ioctl.
+ */
+struct kdbus_cmd_recv {
+ __u64 size;
+ __u64 flags;
+ __u64 return_flags;
+ __s64 priority;
+ __u64 dropped_msgs;
+ struct kdbus_msg_info msg;
+ struct kdbus_item items[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_cmd_free - struct to free a slice of memory in the pool
+ * @size: Overall size of this structure
+ * @flags: Flags for the free command, userspace → kernel
+ * @return_flags: Command return flags, kernel → userspace
+ * @offset: The offset of the memory slice, as returned by other
+ * ioctls
+ * @items: Additional items to modify the behavior
+ *
+ * This struct is used with the KDBUS_CMD_FREE ioctl.
+ */
+struct kdbus_cmd_free {
+ __u64 size;
+ __u64 flags;
+ __u64 return_flags;
+ __u64 offset;
+ struct kdbus_item items[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * enum kdbus_hello_flags - flags for struct kdbus_cmd_hello
+ * @KDBUS_HELLO_ACCEPT_FD: The connection allows the reception of
+ * any passed file descriptors
+ * @KDBUS_HELLO_ACTIVATOR: Special-purpose connection which registers
+ * a well-know name for a process to be started
+ * when traffic arrives
+ * @KDBUS_HELLO_POLICY_HOLDER: Special-purpose connection which registers
+ * policy entries for a name. The provided name
+ * is not activated and not registered with the
+ * name database, it only allows unprivileged
+ * connections to acquire a name, talk or discover
+ * a service
+ * @KDBUS_HELLO_MONITOR: Special-purpose connection to monitor
+ * bus traffic
+ */
+enum kdbus_hello_flags {
+ KDBUS_HELLO_ACCEPT_FD = 1ULL << 0,
+ KDBUS_HELLO_ACTIVATOR = 1ULL << 1,
+ KDBUS_HELLO_POLICY_HOLDER = 1ULL << 2,
+ KDBUS_HELLO_MONITOR = 1ULL << 3,
+};
+
+/**
+ * struct kdbus_cmd_hello - struct to say hello to kdbus
+ * @size: The total size of the structure
+ * @flags: Connection flags (KDBUS_HELLO_*), userspace → kernel
+ * @return_flags: Command return flags, kernel → userspace
+ * @attach_flags_send: Mask of metadata to attach to each message sent
+ * off by this connection (KDBUS_ATTACH_*)
+ * @attach_flags_recv: Mask of metadata to attach to each message receieved
+ * by the new connection (KDBUS_ATTACH_*)
+ * @bus_flags: The flags field copied verbatim from the original
+ * KDBUS_CMD_BUS_MAKE ioctl. It's intended to be useful
+ * to do negotiation of features of the payload that is
+ * transferred (kernel → userspace)
+ * @id: The ID of this connection (kernel → userspace)
+ * @pool_size: Size of the connection's buffer where the received
+ * messages are placed
+ * @offset: Pool offset where items are returned to report
+ * additional information about the bus and the newly
+ * created connection.
+ * @items_size: Size of buffer returned in the pool slice at @offset.
+ * @id128: Unique 128-bit ID of the bus (kernel → userspace)
+ * @items: A list of items
+ *
+ * This struct is used with the KDBUS_CMD_HELLO ioctl.
+ */
+struct kdbus_cmd_hello {
+ __u64 size;
+ __u64 flags;
+ __u64 return_flags;
+ __u64 attach_flags_send;
+ __u64 attach_flags_recv;
+ __u64 bus_flags;
+ __u64 id;
+ __u64 pool_size;
+ __u64 offset;
+ __u64 items_size;
+ __u8 id128[16];
+ struct kdbus_item items[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_info - connection information
+ * @size: total size of the struct
+ * @id: 64bit object ID
+ * @flags: object creation flags
+ * @items: list of items
+ *
+ * Note that the user is responsible for freeing the allocated memory with
+ * the KDBUS_CMD_FREE ioctl.
+ */
+struct kdbus_info {
+ __u64 size;
+ __u64 id;
+ __u64 flags;
+ struct kdbus_item items[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * enum kdbus_list_flags - what to include into the returned list
+ * @KDBUS_LIST_UNIQUE: active connections
+ * @KDBUS_LIST_ACTIVATORS: activator connections
+ * @KDBUS_LIST_NAMES: known well-known names
+ * @KDBUS_LIST_QUEUED: queued-up names
+ */
+enum kdbus_list_flags {
+ KDBUS_LIST_UNIQUE = 1ULL << 0,
+ KDBUS_LIST_NAMES = 1ULL << 1,
+ KDBUS_LIST_ACTIVATORS = 1ULL << 2,
+ KDBUS_LIST_QUEUED = 1ULL << 3,
+};
+
+/**
+ * struct kdbus_cmd_list - list connections
+ * @size: overall size of this object
+ * @flags: flags for the query (KDBUS_LIST_*), userspace → kernel
+ * @return_flags: command return flags, kernel → userspace
+ * @offset: Offset in the caller's pool buffer where an array of
+ * kdbus_info objects is stored.
+ * The user must use KDBUS_CMD_FREE to free the
+ * allocated memory.
+ * @list_size: size of returned list in bytes
+ * @items: Items for the command. Reserved for future use.
+ *
+ * This structure is used with the KDBUS_CMD_LIST ioctl.
+ */
+struct kdbus_cmd_list {
+ __u64 size;
+ __u64 flags;
+ __u64 return_flags;
+ __u64 offset;
+ __u64 list_size;
+ struct kdbus_item items[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * struct kdbus_cmd_info - struct used for KDBUS_CMD_CONN_INFO ioctl
+ * @size: The total size of the struct
+ * @flags: Flags for this ioctl, userspace → kernel
+ * @return_flags: Command return flags, kernel → userspace
+ * @id: The 64-bit ID of the connection. If set to zero, passing
+ * @name is required. kdbus will look up the name to
+ * determine the ID in this case.
+ * @attach_flags: Set of attach flags to specify the set of information
+ * to receive, userspace → kernel
+ * @offset: Returned offset in the caller's pool buffer where the
+ * kdbus_info struct result is stored. The user must
+ * use KDBUS_CMD_FREE to free the allocated memory.
+ * @info_size: Output buffer to report size of data at @offset.
+ * @items: The optional item list, containing the
+ * well-known name to look up as a KDBUS_ITEM_NAME.
+ * Only needed in case @id is zero.
+ *
+ * On success, the KDBUS_CMD_CONN_INFO ioctl will return 0 and @offset will
+ * tell the user the offset in the connection pool buffer at which to find the
+ * result in a struct kdbus_info.
+ */
+struct kdbus_cmd_info {
+ __u64 size;
+ __u64 flags;
+ __u64 return_flags;
+ __u64 id;
+ __u64 attach_flags;
+ __u64 offset;
+ __u64 info_size;
+ struct kdbus_item items[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * enum kdbus_cmd_match_flags - flags to control the KDBUS_CMD_MATCH_ADD ioctl
+ * @KDBUS_MATCH_REPLACE: If entries with the supplied cookie already
+ * exists, remove them before installing the new
+ * matches.
+ */
+enum kdbus_cmd_match_flags {
+ KDBUS_MATCH_REPLACE = 1ULL << 0,
+};
+
+/**
+ * struct kdbus_cmd_match - struct to add or remove matches
+ * @size: The total size of the struct
+ * @flags: Flags for match command (KDBUS_MATCH_*),
+ * userspace → kernel
+ * @return_flags: Command return flags, kernel → userspace
+ * @cookie: Userspace supplied cookie. When removing, the cookie
+ * identifies the match to remove
+ * @items: A list of items for additional information
+ *
+ * This structure is used with the KDBUS_CMD_MATCH_ADD and
+ * KDBUS_CMD_MATCH_REMOVE ioctl.
+ */
+struct kdbus_cmd_match {
+ __u64 size;
+ __u64 flags;
+ __u64 return_flags;
+ __u64 cookie;
+ struct kdbus_item items[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * enum kdbus_make_flags - Flags for KDBUS_CMD_{BUS,ENDPOINT}_MAKE
+ * @KDBUS_MAKE_ACCESS_GROUP: Make the bus or endpoint node group-accessible
+ * @KDBUS_MAKE_ACCESS_WORLD: Make the bus or endpoint node world-accessible
+ */
+enum kdbus_make_flags {
+ KDBUS_MAKE_ACCESS_GROUP = 1ULL << 0,
+ KDBUS_MAKE_ACCESS_WORLD = 1ULL << 1,
+};
+
+/**
+ * enum kdbus_name_flags - flags for KDBUS_CMD_NAME_ACQUIRE
+ * @KDBUS_NAME_REPLACE_EXISTING: Try to replace name of other connections
+ * @KDBUS_NAME_ALLOW_REPLACEMENT: Allow the replacement of the name
+ * @KDBUS_NAME_QUEUE: Name should be queued if busy
+ * @KDBUS_NAME_IN_QUEUE: Name is queued
+ * @KDBUS_NAME_ACTIVATOR: Name is owned by a activator connection
+ * @KDBUS_NAME_PRIMARY: Primary owner of the name
+ * @KDBUS_NAME_ACQUIRED: Name was acquired/queued _now_
+ */
+enum kdbus_name_flags {
+ KDBUS_NAME_REPLACE_EXISTING = 1ULL << 0,
+ KDBUS_NAME_ALLOW_REPLACEMENT = 1ULL << 1,
+ KDBUS_NAME_QUEUE = 1ULL << 2,
+ KDBUS_NAME_IN_QUEUE = 1ULL << 3,
+ KDBUS_NAME_ACTIVATOR = 1ULL << 4,
+ KDBUS_NAME_PRIMARY = 1ULL << 5,
+ KDBUS_NAME_ACQUIRED = 1ULL << 6,
+};
+
+/**
+ * struct kdbus_cmd - generic ioctl payload
+ * @size: Overall size of this structure
+ * @flags: Flags for this ioctl, userspace → kernel
+ * @return_flags: Ioctl return flags, kernel → userspace
+ * @items: Additional items to modify the behavior
+ *
+ * This is a generic ioctl payload object. It's used by all ioctls that only
+ * take flags and items as input.
+ */
+struct kdbus_cmd {
+ __u64 size;
+ __u64 flags;
+ __u64 return_flags;
+ struct kdbus_item items[0];
+} __attribute__((__aligned__(8)));
+
+/**
+ * Ioctl API
+ *
+ * KDBUS_CMD_BUS_MAKE: After opening the "control" node, this command
+ * creates a new bus with the specified
+ * name. The bus is immediately shut down and
+ * cleaned up when the opened file descriptor is
+ * closed.
+ *
+ * KDBUS_CMD_ENDPOINT_MAKE: Creates a new named special endpoint to talk to
+ * the bus. Such endpoints usually carry a more
+ * restrictive policy and grant restricted access
+ * to specific applications.
+ * KDBUS_CMD_ENDPOINT_UPDATE: Update the properties of a custom enpoint. Used
+ * to update the policy.
+ *
+ * KDBUS_CMD_HELLO: By opening the bus node, a connection is
+ * created. After a HELLO the opened connection
+ * becomes an active peer on the bus.
+ * KDBUS_CMD_UPDATE: Update the properties of a connection. Used to
+ * update the metadata subscription mask and
+ * policy.
+ * KDBUS_CMD_BYEBYE: Disconnect a connection. If there are no
+ * messages queued up in the connection's pool,
+ * the call succeeds, and the handle is rendered
+ * unusable. Otherwise, -EBUSY is returned without
+ * any further side-effects.
+ * KDBUS_CMD_FREE: Release the allocated memory in the receiver's
+ * pool.
+ * KDBUS_CMD_CONN_INFO: Retrieve credentials and properties of the
+ * initial creator of the connection. The data was
+ * stored at registration time and does not
+ * necessarily represent the connected process or
+ * the actual state of the process.
+ * KDBUS_CMD_BUS_CREATOR_INFO: Retrieve information of the creator of the bus
+ * a connection is attached to.
+ *
+ * KDBUS_CMD_SEND: Send a message and pass data from userspace to
+ * the kernel.
+ * KDBUS_CMD_RECV: Receive a message from the kernel which is
+ * placed in the receiver's pool.
+ *
+ * KDBUS_CMD_NAME_ACQUIRE: Request a well-known bus name to associate with
+ * the connection. Well-known names are used to
+ * address a peer on the bus.
+ * KDBUS_CMD_NAME_RELEASE: Release a well-known name the connection
+ * currently owns.
+ * KDBUS_CMD_LIST: Retrieve the list of all currently registered
+ * well-known and unique names.
+ *
+ * KDBUS_CMD_MATCH_ADD: Install a match which broadcast messages should
+ * be delivered to the connection.
+ * KDBUS_CMD_MATCH_REMOVE: Remove a current match for broadcast messages.
+ */
+enum kdbus_ioctl_type {
+ /* bus owner (00-0f) */
+ KDBUS_CMD_BUS_MAKE = _IOW(KDBUS_IOCTL_MAGIC, 0x00,
+ struct kdbus_cmd),
+
+ /* endpoint owner (10-1f) */
+ KDBUS_CMD_ENDPOINT_MAKE = _IOW(KDBUS_IOCTL_MAGIC, 0x10,
+ struct kdbus_cmd),
+ KDBUS_CMD_ENDPOINT_UPDATE = _IOW(KDBUS_IOCTL_MAGIC, 0x11,
+ struct kdbus_cmd),
+
+ /* connection owner (80-ff) */
+ KDBUS_CMD_HELLO = _IOWR(KDBUS_IOCTL_MAGIC, 0x80,
+ struct kdbus_cmd_hello),
+ KDBUS_CMD_UPDATE = _IOW(KDBUS_IOCTL_MAGIC, 0x81,
+ struct kdbus_cmd),
+ KDBUS_CMD_BYEBYE = _IOW(KDBUS_IOCTL_MAGIC, 0x82,
+ struct kdbus_cmd),
+ KDBUS_CMD_FREE = _IOW(KDBUS_IOCTL_MAGIC, 0x83,
+ struct kdbus_cmd_free),
+ KDBUS_CMD_CONN_INFO = _IOR(KDBUS_IOCTL_MAGIC, 0x84,
+ struct kdbus_cmd_info),
+ KDBUS_CMD_BUS_CREATOR_INFO = _IOR(KDBUS_IOCTL_MAGIC, 0x85,
+ struct kdbus_cmd_info),
+ KDBUS_CMD_LIST = _IOR(KDBUS_IOCTL_MAGIC, 0x86,
+ struct kdbus_cmd_list),
+
+ KDBUS_CMD_SEND = _IOW(KDBUS_IOCTL_MAGIC, 0x90,
+ struct kdbus_cmd_send),
+ KDBUS_CMD_RECV = _IOR(KDBUS_IOCTL_MAGIC, 0x91,
+ struct kdbus_cmd_recv),
+
+ KDBUS_CMD_NAME_ACQUIRE = _IOW(KDBUS_IOCTL_MAGIC, 0xa0,
+ struct kdbus_cmd),
+ KDBUS_CMD_NAME_RELEASE = _IOW(KDBUS_IOCTL_MAGIC, 0xa1,
+ struct kdbus_cmd),
+
+ KDBUS_CMD_MATCH_ADD = _IOW(KDBUS_IOCTL_MAGIC, 0xb0,
+ struct kdbus_cmd_match),
+ KDBUS_CMD_MATCH_REMOVE = _IOW(KDBUS_IOCTL_MAGIC, 0xb1,
+ struct kdbus_cmd_match),
+};
+
+#endif /* _UAPI_KDBUS_H_ */
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_DEFAULTS_H
+#define __KDBUS_DEFAULTS_H
+
+#include <linux/kernel.h>
+
+/* maximum size of message header and items */
+#define KDBUS_MSG_MAX_SIZE SZ_8K
+
+/* maximum number of memfd items per message */
+#define KDBUS_MSG_MAX_MEMFD_ITEMS 16
+
+/* max size of ioctl command data */
+#define KDBUS_CMD_MAX_SIZE SZ_32K
+
+/* maximum number of inflight fds in a target queue per user */
+#define KDBUS_CONN_MAX_FDS_PER_USER 16
+
+/* maximum message payload size */
+#define KDBUS_MSG_MAX_PAYLOAD_VEC_SIZE SZ_2M
+
+/* maximum size of bloom bit field in bytes */
+#define KDBUS_BUS_BLOOM_MAX_SIZE SZ_4K
+
+/* maximum length of well-known bus name */
+#define KDBUS_NAME_MAX_LEN 255
+
+/* maximum length of bus, domain, ep name */
+#define KDBUS_SYSNAME_MAX_LEN 63
+
+/* maximum number of matches per connection */
+#define KDBUS_MATCH_MAX 256
+
+/* maximum number of queued messages from the same individual user */
+#define KDBUS_CONN_MAX_MSGS 256
+
+/* maximum number of well-known names per connection */
+#define KDBUS_CONN_MAX_NAMES 256
+
+/* maximum number of queued requests waiting for a reply */
+#define KDBUS_CONN_MAX_REQUESTS_PENDING 1024
+
+/* maximum number of connections per user in one domain */
+#define KDBUS_USER_MAX_CONN 1024
+
+/* maximum number of buses per user in one domain */
+#define KDBUS_USER_MAX_BUSES 16
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+
+#include "util.h"
+#include "fs.h"
+#include "handle.h"
+#include "metadata.h"
+#include "node.h"
+
+/*
+ * This is a simplified outline of the internal kdbus object relations, for
+ * those interested in the inner life of the driver implementation.
+ *
+ * From a mount point's (domain's) perspective:
+ *
+ * struct kdbus_domain
+ * |» struct kdbus_user *user (many, owned)
+ * '» struct kdbus_node node (embedded)
+ * |» struct kdbus_node children (many, referenced)
+ * |» struct kdbus_node *parent (pinned)
+ * '» struct kdbus_bus (many, pinned)
+ * |» struct kdbus_node node (embedded)
+ * '» struct kdbus_ep (many, pinned)
+ * |» struct kdbus_node node (embedded)
+ * |» struct kdbus_bus *bus (pinned)
+ * |» struct kdbus_conn conn_list (many, pinned)
+ * | |» struct kdbus_ep *ep (pinned)
+ * | |» struct kdbus_name_entry *activator_of (owned)
+ * | |» struct kdbus_match_db *match_db (owned)
+ * | |» struct kdbus_meta *meta (owned)
+ * | |» struct kdbus_match_db *match_db (owned)
+ * | | '» struct kdbus_match_entry (many, owned)
+ * | |
+ * | |» struct kdbus_pool *pool (owned)
+ * | | '» struct kdbus_pool_slice *slices (many, owned)
+ * | | '» struct kdbus_pool *pool (pinned)
+ * | |
+ * | |» struct kdbus_user *user (pinned)
+ * | `» struct kdbus_queue_entry entries (many, embedded)
+ * | |» struct kdbus_pool_slice *slice (pinned)
+ * | |» struct kdbus_conn_reply *reply (owned)
+ * | '» struct kdbus_user *user (pinned)
+ * |
+ * '» struct kdbus_user *user (pinned)
+ * '» struct kdbus_policy_db policy_db (embedded)
+ * |» struct kdbus_policy_db_entry (many, owned)
+ * | |» struct kdbus_conn (pinned)
+ * | '» struct kdbus_ep (pinned)
+ * |
+ * '» struct kdbus_policy_db_cache_entry (many, owned)
+ * '» struct kdbus_conn (pinned)
+ *
+ * For the life-time of a file descriptor derived from calling open() on a file
+ * inside the mount point:
+ *
+ * struct kdbus_handle
+ * |» struct kdbus_meta *meta (owned)
+ * |» struct kdbus_ep *ep (pinned)
+ * |» struct kdbus_conn *conn (owned)
+ * '» struct kdbus_ep *ep (owned)
+ */
+
+/* kdbus mount-point /sys/fs/kdbus */
+static struct kobject *kdbus_dir;
+
+static int __init kdbus_init(void)
+{
+ int ret;
+
+ kdbus_dir = kobject_create_and_add(KBUILD_MODNAME, fs_kobj);
+ if (!kdbus_dir)
+ return -ENOMEM;
+
+ ret = kdbus_fs_init();
+ if (ret < 0) {
+ pr_err("cannot register filesystem: %d\n", ret);
+ goto exit_dir;
+ }
+
+ pr_info("initialized\n");
+ return 0;
+
+exit_dir:
+ kobject_put(kdbus_dir);
+ return ret;
+}
+
+static void __exit kdbus_exit(void)
+{
+ kdbus_fs_exit();
+ kobject_put(kdbus_dir);
+ ida_destroy(&kdbus_node_ida);
+}
+
+module_init(kdbus_init);
+module_exit(kdbus_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("D-Bus, powerful, easy to use interprocess communication");
+MODULE_ALIAS_FS(KBUILD_MODNAME "fs");
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/fs.h>
+#include <linux/hash.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "endpoint.h"
+#include "handle.h"
+#include "item.h"
+#include "match.h"
+#include "message.h"
+#include "names.h"
+
+/**
+ * struct kdbus_match_db - message filters
+ * @entries_list: List of matches
+ * @mdb_rwlock: Match data lock
+ * @entries_count: Number of entries in database
+ */
+struct kdbus_match_db {
+ struct list_head entries_list;
+ struct rw_semaphore mdb_rwlock;
+ unsigned int entries_count;
+};
+
+/**
+ * struct kdbus_match_entry - a match database entry
+ * @cookie: User-supplied cookie to lookup the entry
+ * @list_entry: The list entry element for the db list
+ * @rules_list: The list head for tracking rules of this entry
+ */
+struct kdbus_match_entry {
+ u64 cookie;
+ struct list_head list_entry;
+ struct list_head rules_list;
+};
+
+/**
+ * struct kdbus_bloom_mask - mask to match against filter
+ * @generations: Number of generations carried
+ * @data: Array of bloom bit fields
+ */
+struct kdbus_bloom_mask {
+ u64 generations;
+ u64 *data;
+};
+
+/**
+ * struct kdbus_match_rule - a rule appended to a match entry
+ * @type: An item type to match against
+ * @bloom_mask: Bloom mask to match a message's filter against, used
+ * with KDBUS_ITEM_BLOOM_MASK
+ * @name: Name to match against, used with KDBUS_ITEM_NAME,
+ * KDBUS_ITEM_NAME_{ADD,REMOVE,CHANGE}
+ * @old_id: ID to match against, used with
+ * KDBUS_ITEM_NAME_{ADD,REMOVE,CHANGE},
+ * KDBUS_ITEM_ID_REMOVE
+ * @new_id: ID to match against, used with
+ * KDBUS_ITEM_NAME_{ADD,REMOVE,CHANGE},
+ * KDBUS_ITEM_ID_REMOVE
+ * @src_id: ID to match against, used with KDBUS_ITEM_ID
+ * @dst_id: Message destination ID, used with KDBUS_ITEM_DST_ID
+ * @rules_entry: Entry in the entry's rules list
+ */
+struct kdbus_match_rule {
+ u64 type;
+ union {
+ struct kdbus_bloom_mask bloom_mask;
+ struct {
+ char *name;
+ u64 old_id;
+ u64 new_id;
+ };
+ u64 src_id;
+ u64 dst_id;
+ };
+ struct list_head rules_entry;
+};
+
+static void kdbus_match_rule_free(struct kdbus_match_rule *rule)
+{
+ if (!rule)
+ return;
+
+ switch (rule->type) {
+ case KDBUS_ITEM_BLOOM_MASK:
+ kfree(rule->bloom_mask.data);
+ break;
+
+ case KDBUS_ITEM_NAME:
+ case KDBUS_ITEM_NAME_ADD:
+ case KDBUS_ITEM_NAME_REMOVE:
+ case KDBUS_ITEM_NAME_CHANGE:
+ kfree(rule->name);
+ break;
+
+ case KDBUS_ITEM_ID:
+ case KDBUS_ITEM_DST_ID:
+ case KDBUS_ITEM_ID_ADD:
+ case KDBUS_ITEM_ID_REMOVE:
+ break;
+
+ default:
+ BUG();
+ }
+
+ list_del(&rule->rules_entry);
+ kfree(rule);
+}
+
+static void kdbus_match_entry_free(struct kdbus_match_entry *entry)
+{
+ struct kdbus_match_rule *r, *tmp;
+
+ if (!entry)
+ return;
+
+ list_for_each_entry_safe(r, tmp, &entry->rules_list, rules_entry)
+ kdbus_match_rule_free(r);
+
+ list_del(&entry->list_entry);
+ kfree(entry);
+}
+
+/**
+ * kdbus_match_db_free() - free match db resources
+ * @mdb: The match database
+ */
+void kdbus_match_db_free(struct kdbus_match_db *mdb)
+{
+ struct kdbus_match_entry *entry, *tmp;
+
+ if (!mdb)
+ return;
+
+ list_for_each_entry_safe(entry, tmp, &mdb->entries_list, list_entry)
+ kdbus_match_entry_free(entry);
+
+ kfree(mdb);
+}
+
+/**
+ * kdbus_match_db_new() - create a new match database
+ *
+ * Return: a new kdbus_match_db on success, ERR_PTR on failure.
+ */
+struct kdbus_match_db *kdbus_match_db_new(void)
+{
+ struct kdbus_match_db *d;
+
+ d = kzalloc(sizeof(*d), GFP_KERNEL);
+ if (!d)
+ return ERR_PTR(-ENOMEM);
+
+ init_rwsem(&d->mdb_rwlock);
+ INIT_LIST_HEAD(&d->entries_list);
+
+ return d;
+}
+
+static bool kdbus_match_bloom(const struct kdbus_bloom_filter *filter,
+ const struct kdbus_bloom_mask *mask,
+ const struct kdbus_conn *conn)
+{
+ size_t n = conn->ep->bus->bloom.size / sizeof(u64);
+ const u64 *m;
+ size_t i;
+
+ /*
+ * The message's filter carries a generation identifier, the
+ * match's mask possibly carries an array of multiple generations
+ * of the mask. Select the mask with the closest match of the
+ * filter's generation.
+ */
+ m = mask->data + (min(filter->generation, mask->generations - 1) * n);
+
+ /*
+ * The message's filter contains the messages properties,
+ * the match's mask contains the properties to look for in the
+ * message. Check the mask bit field against the filter bit field,
+ * if the message possibly carries the properties the connection
+ * has subscribed to.
+ */
+ for (i = 0; i < n; i++)
+ if ((filter->data[i] & m[i]) != m[i])
+ return false;
+
+ return true;
+}
+
+static bool kdbus_match_rule_conn(const struct kdbus_match_rule *r,
+ struct kdbus_conn *c,
+ const struct kdbus_staging *s)
+{
+ lockdep_assert_held(&c->ep->bus->name_registry->rwlock);
+
+ switch (r->type) {
+ case KDBUS_ITEM_BLOOM_MASK:
+ return kdbus_match_bloom(s->bloom_filter, &r->bloom_mask, c);
+ case KDBUS_ITEM_ID:
+ return r->src_id == c->id || r->src_id == KDBUS_MATCH_ID_ANY;
+ case KDBUS_ITEM_DST_ID:
+ return r->dst_id == s->msg->dst_id ||
+ r->dst_id == KDBUS_MATCH_ID_ANY;
+ case KDBUS_ITEM_NAME:
+ return kdbus_conn_has_name(c, r->name);
+ default:
+ return false;
+ }
+}
+
+static bool kdbus_match_rule_kernel(const struct kdbus_match_rule *r,
+ const struct kdbus_staging *s)
+{
+ struct kdbus_item *n = s->notify;
+
+ if (WARN_ON(!n) || n->type != r->type)
+ return false;
+
+ switch (r->type) {
+ case KDBUS_ITEM_ID_ADD:
+ return r->new_id == KDBUS_MATCH_ID_ANY ||
+ r->new_id == n->id_change.id;
+ case KDBUS_ITEM_ID_REMOVE:
+ return r->old_id == KDBUS_MATCH_ID_ANY ||
+ r->old_id == n->id_change.id;
+ case KDBUS_ITEM_NAME_ADD:
+ case KDBUS_ITEM_NAME_CHANGE:
+ case KDBUS_ITEM_NAME_REMOVE:
+ return (r->old_id == KDBUS_MATCH_ID_ANY ||
+ r->old_id == n->name_change.old_id.id) &&
+ (r->new_id == KDBUS_MATCH_ID_ANY ||
+ r->new_id == n->name_change.new_id.id) &&
+ (!r->name || !strcmp(r->name, n->name_change.name));
+ default:
+ return false;
+ }
+}
+
+static bool kdbus_match_rules(const struct kdbus_match_entry *entry,
+ struct kdbus_conn *c,
+ const struct kdbus_staging *s)
+{
+ struct kdbus_match_rule *r;
+
+ list_for_each_entry(r, &entry->rules_list, rules_entry)
+ if ((c && !kdbus_match_rule_conn(r, c, s)) ||
+ (!c && !kdbus_match_rule_kernel(r, s)))
+ return false;
+
+ return true;
+}
+
+/**
+ * kdbus_match_db_match_msg() - match a msg object agains the database entries
+ * @mdb: The match database
+ * @conn_src: The connection object originating the message
+ * @staging: Staging object containing the message to match against
+ *
+ * This function will walk through all the database entries previously uploaded
+ * with kdbus_match_db_add(). As soon as any of them has an all-satisfied rule
+ * set, this function will return true.
+ *
+ * The caller must hold the registry lock of conn_src->ep->bus, in case conn_src
+ * is non-NULL.
+ *
+ * Return: true if there was a matching database entry, false otherwise.
+ */
+bool kdbus_match_db_match_msg(struct kdbus_match_db *mdb,
+ struct kdbus_conn *conn_src,
+ const struct kdbus_staging *staging)
+{
+ struct kdbus_match_entry *entry;
+ bool matched = false;
+
+ down_read(&mdb->mdb_rwlock);
+ list_for_each_entry(entry, &mdb->entries_list, list_entry) {
+ matched = kdbus_match_rules(entry, conn_src, staging);
+ if (matched)
+ break;
+ }
+ up_read(&mdb->mdb_rwlock);
+
+ return matched;
+}
+
+static int kdbus_match_db_remove_unlocked(struct kdbus_match_db *mdb,
+ u64 cookie)
+{
+ struct kdbus_match_entry *entry, *tmp;
+ bool found = false;
+
+ list_for_each_entry_safe(entry, tmp, &mdb->entries_list, list_entry)
+ if (entry->cookie == cookie) {
+ kdbus_match_entry_free(entry);
+ --mdb->entries_count;
+ found = true;
+ }
+
+ return found ? 0 : -EBADSLT;
+}
+
+/**
+ * kdbus_cmd_match_add() - handle KDBUS_CMD_MATCH_ADD
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * One call to this function (or one ioctl(KDBUS_CMD_MATCH_ADD), respectively,
+ * adds one new database entry with n rules attached to it. Each rule is
+ * described with an kdbus_item, and an entry is considered matching if all
+ * its rules are satisfied.
+ *
+ * The items attached to a kdbus_cmd_match struct have the following mapping:
+ *
+ * KDBUS_ITEM_BLOOM_MASK: A bloom mask
+ * KDBUS_ITEM_NAME: A connection's source name
+ * KDBUS_ITEM_ID: A connection ID
+ * KDBUS_ITEM_DST_ID: A connection ID
+ * KDBUS_ITEM_NAME_ADD:
+ * KDBUS_ITEM_NAME_REMOVE:
+ * KDBUS_ITEM_NAME_CHANGE: Well-known name changes, carry
+ * kdbus_notify_name_change
+ * KDBUS_ITEM_ID_ADD:
+ * KDBUS_ITEM_ID_REMOVE: Connection ID changes, carry
+ * kdbus_notify_id_change
+ *
+ * For kdbus_notify_{id,name}_change structs, only the ID and name fields
+ * are looked at when adding an entry. The flags are unused.
+ *
+ * Also note that KDBUS_ITEM_BLOOM_MASK, KDBUS_ITEM_NAME, KDBUS_ITEM_ID,
+ * and KDBUS_ITEM_DST_ID are used to match messages from userspace, while the
+ * others apply to kernel-generated notifications.
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_match_add(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_match_db *mdb = conn->match_db;
+ struct kdbus_match_entry *entry = NULL;
+ struct kdbus_cmd_match *cmd;
+ struct kdbus_item *item;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_BLOOM_MASK, .multiple = true },
+ { .type = KDBUS_ITEM_NAME, .multiple = true },
+ { .type = KDBUS_ITEM_ID, .multiple = true },
+ { .type = KDBUS_ITEM_DST_ID, .multiple = true },
+ { .type = KDBUS_ITEM_NAME_ADD, .multiple = true },
+ { .type = KDBUS_ITEM_NAME_REMOVE, .multiple = true },
+ { .type = KDBUS_ITEM_NAME_CHANGE, .multiple = true },
+ { .type = KDBUS_ITEM_ID_ADD, .multiple = true },
+ { .type = KDBUS_ITEM_ID_REMOVE, .multiple = true },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_MATCH_REPLACE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ if (!kdbus_conn_is_ordinary(conn))
+ return -EOPNOTSUPP;
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ entry->cookie = cmd->cookie;
+ INIT_LIST_HEAD(&entry->list_entry);
+ INIT_LIST_HEAD(&entry->rules_list);
+
+ KDBUS_ITEMS_FOREACH(item, cmd->items, KDBUS_ITEMS_SIZE(cmd, items)) {
+ struct kdbus_match_rule *rule;
+ size_t size = item->size - offsetof(struct kdbus_item, data);
+
+ rule = kzalloc(sizeof(*rule), GFP_KERNEL);
+ if (!rule) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ rule->type = item->type;
+ INIT_LIST_HEAD(&rule->rules_entry);
+
+ switch (item->type) {
+ case KDBUS_ITEM_BLOOM_MASK: {
+ u64 bsize = conn->ep->bus->bloom.size;
+ u64 generations;
+ u64 remainder;
+
+ generations = div64_u64_rem(size, bsize, &remainder);
+ if (size < bsize || remainder > 0) {
+ ret = -EDOM;
+ break;
+ }
+
+ rule->bloom_mask.data = kmemdup(item->data,
+ size, GFP_KERNEL);
+ if (!rule->bloom_mask.data) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ rule->bloom_mask.generations = generations;
+ break;
+ }
+
+ case KDBUS_ITEM_NAME:
+ if (!kdbus_name_is_valid(item->str, false)) {
+ ret = -EINVAL;
+ break;
+ }
+
+ rule->name = kstrdup(item->str, GFP_KERNEL);
+ if (!rule->name)
+ ret = -ENOMEM;
+
+ break;
+
+ case KDBUS_ITEM_ID:
+ rule->src_id = item->id;
+ break;
+
+ case KDBUS_ITEM_DST_ID:
+ rule->dst_id = item->id;
+ break;
+
+ case KDBUS_ITEM_NAME_ADD:
+ case KDBUS_ITEM_NAME_REMOVE:
+ case KDBUS_ITEM_NAME_CHANGE:
+ rule->old_id = item->name_change.old_id.id;
+ rule->new_id = item->name_change.new_id.id;
+
+ if (size > sizeof(struct kdbus_notify_name_change)) {
+ rule->name = kstrdup(item->name_change.name,
+ GFP_KERNEL);
+ if (!rule->name)
+ ret = -ENOMEM;
+ }
+
+ break;
+
+ case KDBUS_ITEM_ID_ADD:
+ case KDBUS_ITEM_ID_REMOVE:
+ if (item->type == KDBUS_ITEM_ID_ADD)
+ rule->new_id = item->id_change.id;
+ else
+ rule->old_id = item->id_change.id;
+
+ break;
+ }
+
+ if (ret < 0) {
+ kdbus_match_rule_free(rule);
+ goto exit;
+ }
+
+ list_add_tail(&rule->rules_entry, &entry->rules_list);
+ }
+
+ down_write(&mdb->mdb_rwlock);
+
+ /* Remove any entry that has the same cookie as the current one. */
+ if (cmd->flags & KDBUS_MATCH_REPLACE)
+ kdbus_match_db_remove_unlocked(mdb, entry->cookie);
+
+ /*
+ * If the above removal caught any entry, there will be room for the
+ * new one.
+ */
+ if (++mdb->entries_count > KDBUS_MATCH_MAX) {
+ --mdb->entries_count;
+ ret = -EMFILE;
+ } else {
+ list_add_tail(&entry->list_entry, &mdb->entries_list);
+ entry = NULL;
+ }
+
+ up_write(&mdb->mdb_rwlock);
+
+exit:
+ kdbus_match_entry_free(entry);
+ return kdbus_args_clear(&args, ret);
+}
+
+/**
+ * kdbus_cmd_match_remove() - handle KDBUS_CMD_MATCH_REMOVE
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_match_remove(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_cmd_match *cmd;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ if (!kdbus_conn_is_ordinary(conn))
+ return -EOPNOTSUPP;
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ down_write(&conn->match_db->mdb_rwlock);
+ ret = kdbus_match_db_remove_unlocked(conn->match_db, cmd->cookie);
+ up_write(&conn->match_db->mdb_rwlock);
+
+ return kdbus_args_clear(&args, ret);
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_MATCH_H
+#define __KDBUS_MATCH_H
+
+struct kdbus_conn;
+struct kdbus_match_db;
+struct kdbus_staging;
+
+struct kdbus_match_db *kdbus_match_db_new(void);
+void kdbus_match_db_free(struct kdbus_match_db *db);
+int kdbus_match_db_add(struct kdbus_conn *conn,
+ struct kdbus_cmd_match *cmd);
+int kdbus_match_db_remove(struct kdbus_conn *conn,
+ struct kdbus_cmd_match *cmd);
+bool kdbus_match_db_match_msg(struct kdbus_match_db *db,
+ struct kdbus_conn *conn_src,
+ const struct kdbus_staging *staging);
+
+int kdbus_cmd_match_add(struct kdbus_conn *conn, void __user *argp);
+int kdbus_cmd_match_remove(struct kdbus_conn *conn, void __user *argp);
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/capability.h>
+#include <linux/cgroup.h>
+#include <linux/cred.h>
+#include <linux/file.h>
+#include <linux/init.h>
+#include <linux/memfd.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <net/sock.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "domain.h"
+#include "endpoint.h"
+#include "handle.h"
+#include "item.h"
+#include "match.h"
+#include "message.h"
+#include "names.h"
+#include "policy.h"
+
+static const char * const zeros = "\0\0\0\0\0\0\0";
+
+static struct kdbus_gaps *kdbus_gaps_new(size_t n_memfds, size_t n_fds)
+{
+ size_t size_offsets, size_memfds, size_fds, size;
+ struct kdbus_gaps *gaps;
+
+ size_offsets = n_memfds * sizeof(*gaps->memfd_offsets);
+ size_memfds = n_memfds * sizeof(*gaps->memfd_files);
+ size_fds = n_fds * sizeof(*gaps->fd_files);
+ size = sizeof(*gaps) + size_offsets + size_memfds + size_fds;
+
+ gaps = kzalloc(size, GFP_KERNEL);
+ if (!gaps)
+ return ERR_PTR(-ENOMEM);
+
+ kref_init(&gaps->kref);
+ gaps->n_memfds = 0; /* we reserve n_memfds, but don't enforce them */
+ gaps->memfd_offsets = (void *)(gaps + 1);
+ gaps->memfd_files = (void *)((u8 *)gaps->memfd_offsets + size_offsets);
+ gaps->n_fds = 0; /* we reserve n_fds, but don't enforce them */
+ gaps->fd_files = (void *)((u8 *)gaps->memfd_files + size_memfds);
+
+ return gaps;
+}
+
+static void kdbus_gaps_free(struct kref *kref)
+{
+ struct kdbus_gaps *gaps = container_of(kref, struct kdbus_gaps, kref);
+ size_t i;
+
+ for (i = 0; i < gaps->n_fds; ++i)
+ if (gaps->fd_files[i])
+ fput(gaps->fd_files[i]);
+ for (i = 0; i < gaps->n_memfds; ++i)
+ if (gaps->memfd_files[i])
+ fput(gaps->memfd_files[i]);
+
+ kfree(gaps);
+}
+
+/**
+ * kdbus_gaps_ref() - gain reference
+ * @gaps: gaps object
+ *
+ * Return: @gaps is returned
+ */
+struct kdbus_gaps *kdbus_gaps_ref(struct kdbus_gaps *gaps)
+{
+ if (gaps)
+ kref_get(&gaps->kref);
+ return gaps;
+}
+
+/**
+ * kdbus_gaps_unref() - drop reference
+ * @gaps: gaps object
+ *
+ * Return: NULL
+ */
+struct kdbus_gaps *kdbus_gaps_unref(struct kdbus_gaps *gaps)
+{
+ if (gaps)
+ kref_put(&gaps->kref, kdbus_gaps_free);
+ return NULL;
+}
+
+/**
+ * kdbus_gaps_install() - install file-descriptors
+ * @gaps: gaps object, or NULL
+ * @slice: pool slice that contains the message
+ * @out_incomplete output variable to note incomplete fds
+ *
+ * This function installs all file-descriptors of @gaps into the current
+ * process and copies the file-descriptor numbers into the target pool slice.
+ *
+ * If the file-descriptors were only partially installed, then @out_incomplete
+ * will be set to true. Otherwise, it's set to false.
+ *
+ * Return: 0 on success, negative error code on failure
+ */
+int kdbus_gaps_install(struct kdbus_gaps *gaps, struct kdbus_pool_slice *slice,
+ bool *out_incomplete)
+{
+ bool incomplete_fds = false;
+ struct kvec kvec;
+ size_t i, n_fds;
+ int ret, *fds;
+
+ if (!gaps) {
+ /* nothing to do */
+ *out_incomplete = incomplete_fds;
+ return 0;
+ }
+
+ n_fds = gaps->n_fds + gaps->n_memfds;
+ if (n_fds < 1) {
+ /* nothing to do */
+ *out_incomplete = incomplete_fds;
+ return 0;
+ }
+
+ fds = kmalloc_array(n_fds, sizeof(*fds), GFP_KERNEL);
+ n_fds = 0;
+ if (!fds)
+ return -ENOMEM;
+
+ /* 1) allocate fds and copy them over */
+
+ if (gaps->n_fds > 0) {
+ for (i = 0; i < gaps->n_fds; ++i) {
+ int fd;
+
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0)
+ incomplete_fds = true;
+
+ WARN_ON(!gaps->fd_files[i]);
+
+ fds[n_fds++] = fd < 0 ? -1 : fd;
+ }
+
+ /*
+ * The file-descriptor array can only be present once per
+ * message. Hence, prepare all fds and then copy them over with
+ * a single kvec.
+ */
+
+ WARN_ON(!gaps->fd_offset);
+
+ kvec.iov_base = fds;
+ kvec.iov_len = gaps->n_fds * sizeof(*fds);
+ ret = kdbus_pool_slice_copy_kvec(slice, gaps->fd_offset,
+ &kvec, 1, kvec.iov_len);
+ if (ret < 0)
+ goto exit;
+ }
+
+ for (i = 0; i < gaps->n_memfds; ++i) {
+ int memfd;
+
+ memfd = get_unused_fd_flags(O_CLOEXEC);
+ if (memfd < 0) {
+ incomplete_fds = true;
+ /* memfds are initialized to -1, skip copying it */
+ continue;
+ }
+
+ fds[n_fds++] = memfd;
+
+ /*
+ * memfds have to be copied individually as they each are put
+ * into a separate item. This should not be an issue, though,
+ * as usually there is no need to send more than one memfd per
+ * message.
+ */
+
+ WARN_ON(!gaps->memfd_offsets[i]);
+ WARN_ON(!gaps->memfd_files[i]);
+
+ kvec.iov_base = &memfd;
+ kvec.iov_len = sizeof(memfd);
+ ret = kdbus_pool_slice_copy_kvec(slice, gaps->memfd_offsets[i],
+ &kvec, 1, kvec.iov_len);
+ if (ret < 0)
+ goto exit;
+ }
+
+ /* 2) install fds now that everything was successful */
+
+ for (i = 0; i < gaps->n_fds; ++i)
+ if (fds[i] >= 0)
+ fd_install(fds[i], get_file(gaps->fd_files[i]));
+ for (i = 0; i < gaps->n_memfds; ++i)
+ if (fds[gaps->n_fds + i] >= 0)
+ fd_install(fds[gaps->n_fds + i],
+ get_file(gaps->memfd_files[i]));
+
+ ret = 0;
+
+exit:
+ if (ret < 0)
+ for (i = 0; i < n_fds; ++i)
+ put_unused_fd(fds[i]);
+ kfree(fds);
+ *out_incomplete = incomplete_fds;
+ return ret;
+}
+
+static struct file *kdbus_get_fd(int fd)
+{
+ struct file *f, *ret;
+
+ if (fd < 0)
+ return ERR_PTR(-EBADF);
+
+ f = fget_raw(fd);
+ if (!f)
+ return ERR_PTR(-EBADF);
+
+ if (f->f_mode & FMODE_PATH)
+ ret = f; /* O_PATH is always allowed */
+ else if (f->f_op == &kdbus_handle_ops)
+ ret = ERR_PTR(-EOPNOTSUPP); /* disallow kdbus-fd over kdbus */
+ else
+ ret = f; /* all other are allowed */
+
+ if (f != ret)
+ fput(f);
+
+ return ret;
+}
+
+static struct file *kdbus_get_memfd(const struct kdbus_memfd *memfd)
+{
+ const int m = F_SEAL_SHRINK | F_SEAL_GROW | F_SEAL_WRITE | F_SEAL_SEAL;
+ struct file *f, *ret;
+ int s;
+
+ if (memfd->fd < 0)
+ return ERR_PTR(-EBADF);
+
+ f = fget(memfd->fd);
+ if (!f)
+ return ERR_PTR(-EBADF);
+
+ s = memfd_fcntl(f, F_GET_SEALS, 0);
+ if (s < 0)
+ ret = ERR_PTR(-EMEDIUMTYPE);
+ else if ((s & m) != m)
+ ret = ERR_PTR(-ETXTBSY);
+ else if (memfd->start + memfd->size > (u64)i_size_read(file_inode(f)))
+ ret = ERR_PTR(-EFAULT);
+ else
+ ret = f;
+
+ if (f != ret)
+ fput(f);
+
+ return ret;
+}
+
+static int kdbus_msg_examine(struct kdbus_msg *msg, struct kdbus_bus *bus,
+ struct kdbus_cmd_send *cmd, size_t *out_n_memfds,
+ size_t *out_n_fds, size_t *out_n_parts)
+{
+ struct kdbus_item *item, *fds = NULL, *bloom = NULL, *dstname = NULL;
+ u64 n_parts, n_memfds, n_fds;
+
+ /*
+ * Step 1:
+ * Validate the message and command parameters.
+ */
+
+ /* KDBUS_PAYLOAD_KERNEL is reserved to kernel messages */
+ if (msg->payload_type == KDBUS_PAYLOAD_KERNEL)
+ return -EINVAL;
+
+ if (msg->dst_id == KDBUS_DST_ID_BROADCAST) {
+ /* broadcasts must be marked as signals */
+ if (!(msg->flags & KDBUS_MSG_SIGNAL))
+ return -EBADMSG;
+ /* broadcasts cannot have timeouts */
+ if (msg->timeout_ns > 0)
+ return -ENOTUNIQ;
+ }
+
+ if (msg->flags & KDBUS_MSG_EXPECT_REPLY) {
+ /* if you expect a reply, you must specify a timeout */
+ if (msg->timeout_ns == 0 || !msg->cookie)
+ return -EINVAL;
+ /* signals cannot have replies */
+ if (msg->flags & KDBUS_MSG_SIGNAL)
+ return -ENOTUNIQ;
+ } else {
+ /* must expect reply if sent as synchronous call */
+ if (cmd->flags & KDBUS_SEND_SYNC_REPLY)
+ return -EINVAL;
+ /* cannot mark replies as signal */
+ if (msg->cookie_reply && (msg->flags & KDBUS_MSG_SIGNAL))
+ return -EINVAL;
+ }
+
+ /*
+ * Step 2:
+ * Validate all passed items. While at it, select some statistics that
+ * are required to allocate state objects later on.
+ *
+ * Generic item validation has already been done via
+ * kdbus_item_validate(). Furthermore, the number of items is naturally
+ * limited by the maximum message size. Hence, only non-generic item
+ * checks are performed here (mainly integer overflow tests).
+ */
+
+ n_parts = 0;
+ n_memfds = 0;
+ n_fds = 0;
+
+ KDBUS_ITEMS_FOREACH(item, msg->items, KDBUS_ITEMS_SIZE(msg, items)) {
+ switch (item->type) {
+ case KDBUS_ITEM_PAYLOAD_VEC: {
+ void __force __user *ptr = KDBUS_PTR(item->vec.address);
+ u64 size = item->vec.size;
+
+ if (size > KDBUS_MSG_MAX_PAYLOAD_VEC_SIZE)
+ return -EMSGSIZE;
+ if (ptr && unlikely(!access_ok(ptr, size)))
+ return -EFAULT;
+
+ if (ptr || size % 8) /* data or padding */
+ ++n_parts;
+ break;
+ }
+ case KDBUS_ITEM_PAYLOAD_MEMFD: {
+ u64 start = item->memfd.start;
+ u64 size = item->memfd.size;
+
+ if (start + size < start)
+ return -EMSGSIZE;
+ if (n_memfds >= KDBUS_MSG_MAX_MEMFD_ITEMS)
+ return -E2BIG;
+
+ ++n_memfds;
+ if (size % 8) /* vec-padding required */
+ ++n_parts;
+ break;
+ }
+ case KDBUS_ITEM_FDS: {
+ if (fds)
+ return -EEXIST;
+
+ fds = item;
+ n_fds = KDBUS_ITEM_PAYLOAD_SIZE(item) / sizeof(int);
+ if (n_fds > KDBUS_CONN_MAX_FDS_PER_USER)
+ return -EMFILE;
+
+ break;
+ }
+ case KDBUS_ITEM_BLOOM_FILTER: {
+ u64 bloom_size;
+
+ if (bloom)
+ return -EEXIST;
+
+ bloom = item;
+ bloom_size = KDBUS_ITEM_PAYLOAD_SIZE(item) -
+ offsetof(struct kdbus_bloom_filter, data);
+ if (!KDBUS_IS_ALIGNED8(bloom_size))
+ return -EFAULT;
+ if (bloom_size != bus->bloom.size)
+ return -EDOM;
+
+ break;
+ }
+ case KDBUS_ITEM_DST_NAME: {
+ if (dstname)
+ return -EEXIST;
+
+ dstname = item;
+ if (!kdbus_name_is_valid(item->str, false))
+ return -EINVAL;
+ if (msg->dst_id == KDBUS_DST_ID_BROADCAST)
+ return -EBADMSG;
+
+ break;
+ }
+ default:
+ return -EINVAL;
+ }
+ }
+
+ /*
+ * Step 3:
+ * Validate that required items were actually passed, and that no item
+ * contradicts the message flags.
+ */
+
+ /* bloom filters must be attached _iff_ it's a signal */
+ if (!(msg->flags & KDBUS_MSG_SIGNAL) != !bloom)
+ return -EBADMSG;
+ /* destination name is required if no ID is given */
+ if (msg->dst_id == KDBUS_DST_ID_NAME && !dstname)
+ return -EDESTADDRREQ;
+ /* cannot send file-descriptors attached to broadcasts */
+ if (msg->dst_id == KDBUS_DST_ID_BROADCAST && fds)
+ return -ENOTUNIQ;
+
+ *out_n_memfds = n_memfds;
+ *out_n_fds = n_fds;
+ *out_n_parts = n_parts;
+
+ return 0;
+}
+
+static bool kdbus_staging_merge_vecs(struct kdbus_staging *staging,
+ struct kdbus_item **prev_item,
+ struct iovec **prev_vec,
+ const struct kdbus_item *merge)
+{
+ void __user *ptr = (void __user *)KDBUS_PTR(merge->vec.address);
+ u64 padding = merge->vec.size % 8;
+ struct kdbus_item *prev = *prev_item;
+ struct iovec *vec = *prev_vec;
+
+ /* XXX: merging is disabled so far */
+ if (0 && prev && prev->type == KDBUS_ITEM_PAYLOAD_OFF &&
+ !merge->vec.address == !prev->vec.address) {
+ /*
+ * If we merge two VECs, we can always drop the second
+ * PAYLOAD_VEC item. Hence, include its size in the previous
+ * one.
+ */
+ prev->vec.size += merge->vec.size;
+
+ if (ptr) {
+ /*
+ * If we merge two data VECs, we need two iovecs to copy
+ * the data. But the items can be easily merged by
+ * summing their lengths.
+ */
+ vec = &staging->parts[staging->n_parts++];
+ vec->iov_len = merge->vec.size;
+ vec->iov_base = ptr;
+ staging->n_payload += vec->iov_len;
+ } else if (padding) {
+ /*
+ * If we merge two 0-vecs with the second 0-vec
+ * requiring padding, we need to insert an iovec to copy
+ * the 0-padding. We try merging it with the previous
+ * 0-padding iovec. This might end up with an
+ * iov_len==0, in which case we simply drop the iovec.
+ */
+ if (vec) {
+ staging->n_payload -= vec->iov_len;
+ vec->iov_len = prev->vec.size % 8;
+ if (!vec->iov_len) {
+ --staging->n_parts;
+ vec = NULL;
+ } else {
+ staging->n_payload += vec->iov_len;
+ }
+ } else {
+ vec = &staging->parts[staging->n_parts++];
+ vec->iov_len = padding;
+ vec->iov_base = (char __user *)zeros;
+ staging->n_payload += vec->iov_len;
+ }
+ } else {
+ /*
+ * If we merge two 0-vecs with the second 0-vec having
+ * no padding, we know the padding of the first stays
+ * the same. Hence, @vec needs no adjustment.
+ */
+ }
+
+ /* successfully merged with previous item */
+ merge = prev;
+ } else {
+ /*
+ * If we cannot merge the payload item with the previous one,
+ * we simply insert a new iovec for the data/padding.
+ */
+ if (ptr) {
+ vec = &staging->parts[staging->n_parts++];
+ vec->iov_len = merge->vec.size;
+ vec->iov_base = ptr;
+ staging->n_payload += vec->iov_len;
+ } else if (padding) {
+ vec = &staging->parts[staging->n_parts++];
+ vec->iov_len = padding;
+ vec->iov_base = (char __user *)zeros;
+ staging->n_payload += vec->iov_len;
+ } else {
+ vec = NULL;
+ }
+ }
+
+ *prev_item = (struct kdbus_item *)merge;
+ *prev_vec = vec;
+
+ return merge == prev;
+}
+
+static int kdbus_staging_import(struct kdbus_staging *staging)
+{
+ struct kdbus_item *it, *item, *last, *prev_payload;
+ struct kdbus_gaps *gaps = staging->gaps;
+ struct kdbus_msg *msg = staging->msg;
+ struct iovec *part, *prev_part;
+ bool drop_item;
+
+ drop_item = false;
+ last = NULL;
+ prev_payload = NULL;
+ prev_part = NULL;
+
+ /*
+ * We modify msg->items along the way; make sure to use @item as offset
+ * to the next item (instead of the iterator @it).
+ */
+ for (it = item = msg->items;
+ it >= msg->items &&
+ (u8 *)it < (u8 *)msg + msg->size &&
+ (u8 *)it + it->size <= (u8 *)msg + msg->size; ) {
+ /*
+ * If we dropped items along the way, move current item to
+ * front. We must not access @it afterwards, but use @item
+ * instead!
+ */
+ if (it != item)
+ memmove(item, it, it->size);
+ it = (void *)((u8 *)it + KDBUS_ALIGN8(item->size));
+
+ switch (item->type) {
+ case KDBUS_ITEM_PAYLOAD_VEC: {
+ size_t offset = staging->n_payload;
+
+ if (kdbus_staging_merge_vecs(staging, &prev_payload,
+ &prev_part, item)) {
+ drop_item = true;
+ } else if (item->vec.address) {
+ /* real offset is patched later on */
+ item->type = KDBUS_ITEM_PAYLOAD_OFF;
+ item->vec.offset = offset;
+ } else {
+ item->type = KDBUS_ITEM_PAYLOAD_OFF;
+ item->vec.offset = ~0ULL;
+ }
+
+ break;
+ }
+ case KDBUS_ITEM_PAYLOAD_MEMFD: {
+ struct file *f;
+
+ f = kdbus_get_memfd(&item->memfd);
+ if (IS_ERR(f))
+ return PTR_ERR(f);
+
+ gaps->memfd_files[gaps->n_memfds] = f;
+ gaps->memfd_offsets[gaps->n_memfds] =
+ (u8 *)&item->memfd.fd - (u8 *)msg;
+ ++gaps->n_memfds;
+
+ /* memfds cannot be merged */
+ prev_payload = item;
+ prev_part = NULL;
+
+ /* insert padding to make following VECs aligned */
+ if (item->memfd.size % 8) {
+ part = &staging->parts[staging->n_parts++];
+ part->iov_len = item->memfd.size % 8;
+ part->iov_base = (char __user *)zeros;
+ staging->n_payload += part->iov_len;
+ }
+
+ break;
+ }
+ case KDBUS_ITEM_FDS: {
+ size_t i, n_fds;
+
+ n_fds = KDBUS_ITEM_PAYLOAD_SIZE(item) / sizeof(int);
+ for (i = 0; i < n_fds; ++i) {
+ struct file *f;
+
+ f = kdbus_get_fd(item->fds[i]);
+ if (IS_ERR(f))
+ return PTR_ERR(f);
+
+ gaps->fd_files[gaps->n_fds++] = f;
+ }
+
+ gaps->fd_offset = (u8 *)item->fds - (u8 *)msg;
+
+ break;
+ }
+ case KDBUS_ITEM_BLOOM_FILTER:
+ staging->bloom_filter = &item->bloom_filter;
+ break;
+ case KDBUS_ITEM_DST_NAME:
+ staging->dst_name = item->str;
+ break;
+ }
+
+ /* drop item if we merged it with a previous one */
+ if (drop_item) {
+ drop_item = false;
+ } else {
+ last = item;
+ item = KDBUS_ITEM_NEXT(item);
+ }
+ }
+
+ /* adjust message size regarding dropped items */
+ msg->size = offsetof(struct kdbus_msg, items);
+ if (last)
+ msg->size += ((u8 *)last - (u8 *)msg->items) + last->size;
+
+ return 0;
+}
+
+static void kdbus_staging_reserve(struct kdbus_staging *staging)
+{
+ struct iovec *part;
+
+ part = &staging->parts[staging->n_parts++];
+ part->iov_base = (void __user *)zeros;
+ part->iov_len = 0;
+}
+
+static struct kdbus_staging *kdbus_staging_new(struct kdbus_bus *bus,
+ size_t n_parts,
+ size_t msg_extra_size)
+{
+ const size_t reserved_parts = 5; /* see below for explanation */
+ struct kdbus_staging *staging;
+ int ret;
+
+ n_parts += reserved_parts;
+
+ staging = kzalloc(sizeof(*staging) + n_parts * sizeof(*staging->parts) +
+ msg_extra_size, GFP_KERNEL);
+ if (!staging)
+ return ERR_PTR(-ENOMEM);
+
+ staging->msg_seqnum = atomic64_inc_return(&bus->last_message_id);
+ staging->n_parts = 0; /* we reserve n_parts, but don't enforce them */
+ staging->parts = (void *)(staging + 1);
+
+ if (msg_extra_size) /* if requested, allocate message, too */
+ staging->msg = (void *)((u8 *)staging->parts +
+ n_parts * sizeof(*staging->parts));
+
+ staging->meta_proc = kdbus_meta_proc_new();
+ if (IS_ERR(staging->meta_proc)) {
+ ret = PTR_ERR(staging->meta_proc);
+ staging->meta_proc = NULL;
+ goto error;
+ }
+
+ staging->meta_conn = kdbus_meta_conn_new();
+ if (IS_ERR(staging->meta_conn)) {
+ ret = PTR_ERR(staging->meta_conn);
+ staging->meta_conn = NULL;
+ goto error;
+ }
+
+ /*
+ * Prepare iovecs to copy the message into the target pool. We use the
+ * following iovecs:
+ * * iovec to copy "kdbus_msg.size"
+ * * iovec to copy "struct kdbus_msg" (minus size) plus items
+ * * iovec for possible padding after the items
+ * * iovec for metadata items
+ * * iovec for possible padding after the items
+ *
+ * Make sure to update @reserved_parts if you add more parts here.
+ */
+
+ kdbus_staging_reserve(staging); /* msg.size */
+ kdbus_staging_reserve(staging); /* msg (minus msg.size) plus items */
+ kdbus_staging_reserve(staging); /* msg padding */
+ kdbus_staging_reserve(staging); /* meta */
+ kdbus_staging_reserve(staging); /* meta padding */
+
+ return staging;
+
+error:
+ kdbus_staging_free(staging);
+ return ERR_PTR(ret);
+}
+
+struct kdbus_staging *kdbus_staging_new_kernel(struct kdbus_bus *bus,
+ u64 dst, u64 cookie_timeout,
+ size_t it_size, size_t it_type)
+{
+ struct kdbus_staging *staging;
+ size_t size;
+
+ size = offsetof(struct kdbus_msg, items) +
+ KDBUS_ITEM_HEADER_SIZE + it_size;
+
+ staging = kdbus_staging_new(bus, 0, KDBUS_ALIGN8(size));
+ if (IS_ERR(staging))
+ return ERR_CAST(staging);
+
+ staging->msg->size = size;
+ staging->msg->flags = (dst == KDBUS_DST_ID_BROADCAST) ?
+ KDBUS_MSG_SIGNAL : 0;
+ staging->msg->dst_id = dst;
+ staging->msg->src_id = KDBUS_SRC_ID_KERNEL;
+ staging->msg->payload_type = KDBUS_PAYLOAD_KERNEL;
+ staging->msg->cookie_reply = cookie_timeout;
+ staging->notify = staging->msg->items;
+ staging->notify->size = KDBUS_ITEM_HEADER_SIZE + it_size;
+ staging->notify->type = it_type;
+
+ return staging;
+}
+
+struct kdbus_staging *kdbus_staging_new_user(struct kdbus_bus *bus,
+ struct kdbus_cmd_send *cmd,
+ struct kdbus_msg *msg)
+{
+ const size_t reserved_parts = 1; /* see below for explanation */
+ size_t n_memfds, n_fds, n_parts;
+ struct kdbus_staging *staging;
+ int ret;
+
+ /*
+ * Examine user-supplied message and figure out how many resources we
+ * need to allocate in our staging area. This requires us to iterate
+ * the message twice, but saves us from re-allocating our resources
+ * all the time.
+ */
+
+ ret = kdbus_msg_examine(msg, bus, cmd, &n_memfds, &n_fds, &n_parts);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ n_parts += reserved_parts;
+
+ /*
+ * Allocate staging area with the number of required resources. Make
+ * sure that we have enough iovecs for all required parts pre-allocated
+ * so this will hopefully be the only memory allocation for this
+ * message transaction.
+ */
+
+ staging = kdbus_staging_new(bus, n_parts, 0);
+ if (IS_ERR(staging))
+ return ERR_CAST(staging);
+
+ staging->msg = msg;
+
+ /*
+ * If the message contains memfds or fd items, we need to remember some
+ * state so we can fill in the requested information at RECV time.
+ * File-descriptors cannot be passed at SEND time. Hence, allocate a
+ * gaps-object to remember that state. That gaps object is linked to
+ * from the staging area, but will also be linked to from the message
+ * queue of each peer. Hence, each receiver owns a reference to it, and
+ * it will later be used to fill the 'gaps' in message that couldn't be
+ * filled at SEND time.
+ * Note that the 'gaps' object is read-only once the staging-allocator
+ * returns. There might be connections receiving a queued message while
+ * the sender still broadcasts the message to other receivers.
+ */
+
+ if (n_memfds > 0 || n_fds > 0) {
+ staging->gaps = kdbus_gaps_new(n_memfds, n_fds);
+ if (IS_ERR(staging->gaps)) {
+ ret = PTR_ERR(staging->gaps);
+ staging->gaps = NULL;
+ kdbus_staging_free(staging);
+ return ERR_PTR(ret);
+ }
+ }
+
+ /*
+ * kdbus_staging_new() already reserves parts for message setup. For
+ * user-supplied messages, we add the following iovecs:
+ * ... variable number of iovecs for payload ...
+ * * final iovec for possible padding of payload
+ *
+ * Make sure to update @reserved_parts if you add more parts here.
+ */
+
+ ret = kdbus_staging_import(staging); /* payload */
+ kdbus_staging_reserve(staging); /* payload padding */
+
+ if (ret < 0)
+ goto error;
+
+ return staging;
+
+error:
+ kdbus_staging_free(staging);
+ return ERR_PTR(ret);
+}
+
+struct kdbus_staging *kdbus_staging_free(struct kdbus_staging *staging)
+{
+ if (!staging)
+ return NULL;
+
+ kdbus_meta_conn_unref(staging->meta_conn);
+ kdbus_meta_proc_unref(staging->meta_proc);
+ kdbus_gaps_unref(staging->gaps);
+ kfree(staging);
+
+ return NULL;
+}
+
+static int kdbus_staging_collect_metadata(struct kdbus_staging *staging,
+ struct kdbus_conn *src,
+ struct kdbus_conn *dst,
+ u64 *out_attach)
+{
+ u64 attach;
+ int ret;
+
+ if (src)
+ attach = kdbus_meta_msg_mask(src, dst);
+ else
+ attach = KDBUS_ATTACH_TIMESTAMP; /* metadata for kernel msgs */
+
+ if (src && !src->meta_fake) {
+ ret = kdbus_meta_proc_collect(staging->meta_proc, attach);
+ if (ret < 0)
+ return ret;
+ }
+
+ ret = kdbus_meta_conn_collect(staging->meta_conn, src,
+ staging->msg_seqnum, attach);
+ if (ret < 0)
+ return ret;
+
+ *out_attach = attach;
+ return 0;
+}
+
+/**
+ * kdbus_staging_emit() - emit linearized message in target pool
+ * @staging: staging object to create message from
+ * @src: sender of the message (or NULL)
+ * @dst: target connection to allocate message for
+ *
+ * This allocates a pool-slice for @dst and copies the message provided by
+ * @staging into it. The new slice is then returned to the caller for further
+ * processing. It's not linked into any queue, yet.
+ *
+ * Return: Newly allocated slice or ERR_PTR on failure.
+ */
+struct kdbus_pool_slice *kdbus_staging_emit(struct kdbus_staging *staging,
+ struct kdbus_conn *src,
+ struct kdbus_conn *dst)
+{
+ struct kdbus_item *item, *meta_items = NULL;
+ struct kdbus_pool_slice *slice = NULL;
+ size_t off, size, meta_size;
+ struct iovec *v;
+ u64 attach, msg_size;
+ int ret;
+ size_t kvec_parts_count, size_before_payload = 0;
+
+ /*
+ * Step 1:
+ * Collect metadata from @src depending on the attach-flags allowed for
+ * @dst. Translate it into the namespaces pinned by @dst.
+ */
+
+ ret = kdbus_staging_collect_metadata(staging, src, dst, &attach);
+ if (ret < 0)
+ goto error;
+
+ ret = kdbus_meta_emit(staging->meta_proc, NULL, staging->meta_conn,
+ dst, attach, &meta_items, &meta_size);
+ if (ret < 0)
+ goto error;
+
+ /*
+ * Step 2:
+ * Setup iovecs for the message. See kdbus_staging_new() for allocation
+ * of those iovecs. All reserved iovecs have been initialized with
+ * iov_len=0 + iov_base=zeros. Furthermore, the iovecs to copy the
+ * actual message payload have already been initialized and need not be
+ * touched.
+ */
+
+ v = staging->parts;
+ msg_size = staging->msg->size;
+
+ /* msg.size */
+ v->iov_len = sizeof(msg_size);
+ v->iov_base = (void __user *)&msg_size;
+ ++v;
+
+ /* msg (after msg.size) plus items */
+ v->iov_len = staging->msg->size - sizeof(staging->msg->size);
+ v->iov_base = (void __user *)((u8 *)staging->msg +
+ sizeof(staging->msg->size));
+ ++v;
+
+ /* padding after msg */
+ v->iov_len = KDBUS_ALIGN8(staging->msg->size) - staging->msg->size;
+ v->iov_base = (void __user *)zeros;
+ ++v;
+
+ if (meta_size > 0) {
+ /* metadata items */
+ v->iov_len = meta_size;
+ v->iov_base = (void __user *)meta_items;
+ ++v;
+
+ /* padding after metadata */
+ v->iov_len = KDBUS_ALIGN8(meta_size) - meta_size;
+ v->iov_base = (void __user *)zeros;
+ ++v;
+
+ msg_size = KDBUS_ALIGN8(msg_size) + meta_size;
+ } else {
+ /* metadata items */
+ v->iov_len = 0;
+ v->iov_base = (void __user *)zeros;
+ ++v;
+
+ /* padding after metadata */
+ v->iov_len = 0;
+ v->iov_base = (void __user *)zeros;
+ ++v;
+ }
+
+ kvec_parts_count = v - staging->parts;
+
+ /* ... payload iovecs are already filled in ... */
+
+ /* compute overall size and fill in padding after payload */
+ size = KDBUS_ALIGN8(msg_size);
+
+ if (staging->n_payload > 0) {
+ size += staging->n_payload;
+
+ v = &staging->parts[staging->n_parts - 1];
+ v->iov_len = KDBUS_ALIGN8(size) - size;
+ v->iov_base = (void __user *)zeros;
+
+ size = KDBUS_ALIGN8(size);
+ }
+
+ /*
+ * Step 3:
+ * The PAYLOAD_OFF items in the message contain a relative 'offset'
+ * field that tells the receiver where to find the actual payload. This
+ * offset is relative to the start of the message, and as such depends
+ * on the size of the metadata items we inserted. This size is variable
+ * and changes for each peer we send the message to. Hence, we remember
+ * the last relative offset that was used to calculate the 'offset'
+ * fields. For each message, we re-calculate it and patch all items, in
+ * case it changed.
+ */
+
+ off = KDBUS_ALIGN8(msg_size);
+
+ if (off != staging->i_payload) {
+ KDBUS_ITEMS_FOREACH(item, staging->msg->items,
+ KDBUS_ITEMS_SIZE(staging->msg, items)) {
+ if (item->type != KDBUS_ITEM_PAYLOAD_OFF)
+ continue;
+
+ item->vec.offset -= staging->i_payload;
+ item->vec.offset += off;
+ }
+
+ staging->i_payload = off;
+ }
+
+ /*
+ * Step 4:
+ * Allocate pool slice and copy over all data. Make sure to properly
+ * account on user quota.
+ */
+
+ ret = kdbus_conn_quota_inc(dst, src ? src->user : NULL, size,
+ staging->gaps ? staging->gaps->n_fds : 0);
+ if (ret < 0)
+ goto error;
+
+ slice = kdbus_pool_slice_alloc(dst->pool, size, true);
+ if (IS_ERR(slice)) {
+ ret = PTR_ERR(slice);
+ slice = NULL;
+ goto error;
+ }
+
+ WARN_ON(kdbus_pool_slice_size(slice) != size);
+
+ {
+ ulong count_parts;
+ for (count_parts = 0; count_parts < kvec_parts_count; count_parts++)
+ size_before_payload += staging->parts[count_parts].iov_len;
+ }
+
+ ret = kdbus_pool_slice_copy_kvec(slice, 0, (struct kvec *)staging->parts,
+ kvec_parts_count, size_before_payload);
+ if (ret < 0)
+ goto error;
+
+ for (; kvec_parts_count < staging->n_parts; kvec_parts_count++) {
+ struct iovec *part = &staging->parts[kvec_parts_count];
+ if (part->iov_base != zeros)
+ ret = kdbus_pool_slice_copy_iovec(slice, size_before_payload,
+ part, 1, part->iov_len);
+ else
+ ret = kdbus_pool_slice_copy_kvec(slice, size_before_payload,
+ (struct kvec *)&part, 1, part->iov_len);
+ if (ret < 0)
+ goto error;
+ size_before_payload += part->iov_len;
+ }
+
+ /* all done, return slice to caller */
+ goto exit;
+
+error:
+ if (slice)
+ kdbus_conn_quota_dec(dst, src ? src->user : NULL, size,
+ staging->gaps ? staging->gaps->n_fds : 0);
+ kdbus_pool_slice_release(slice);
+ slice = ERR_PTR(ret);
+exit:
+ kfree(meta_items);
+ return slice;
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_MESSAGE_H
+#define __KDBUS_MESSAGE_H
+
+#include <linux/fs.h>
+#include <linux/kref.h>
+#include <uapi/linux/kdbus.h>
+
+struct kdbus_bus;
+struct kdbus_conn;
+struct kdbus_meta_conn;
+struct kdbus_meta_proc;
+struct kdbus_pool_slice;
+
+/**
+ * struct kdbus_gaps - gaps in message to be filled later
+ * @kref: Reference counter
+ * @n_memfd_offs: Number of memfds
+ * @memfd_offs: Offsets of kdbus_memfd items in target slice
+ * @n_fds: Number of fds
+ * @fds: Array of sent fds
+ * @fds_offset: Offset of fd-array in target slice
+ *
+ * The 'gaps' object is used to track data that is needed to fill gaps in a
+ * message at RECV time. Usually, we try to compile the whole message at SEND
+ * time. This has the advantage, that we don't have to cache any information and
+ * can keep the memory consumption small. Furthermore, all copy operations can
+ * be combined into a single function call, which speeds up transactions
+ * considerably.
+ * However, things like file-descriptors can only be fully installed at RECV
+ * time. The gaps object tracks this data and pins it until a message is
+ * received. The gaps object is shared between all receivers of the same
+ * message.
+ */
+struct kdbus_gaps {
+ struct kref kref;
+
+ /* state tracking for KDBUS_ITEM_PAYLOAD_MEMFD entries */
+ size_t n_memfds;
+ u64 *memfd_offsets;
+ struct file **memfd_files;
+
+ /* state tracking for KDBUS_ITEM_FDS */
+ size_t n_fds;
+ struct file **fd_files;
+ u64 fd_offset;
+};
+
+struct kdbus_gaps *kdbus_gaps_ref(struct kdbus_gaps *gaps);
+struct kdbus_gaps *kdbus_gaps_unref(struct kdbus_gaps *gaps);
+int kdbus_gaps_install(struct kdbus_gaps *gaps, struct kdbus_pool_slice *slice,
+ bool *out_incomplete);
+
+/**
+ * struct kdbus_staging - staging area to import messages
+ * @msg: User-supplied message
+ * @gaps: Gaps-object created during import (or NULL if empty)
+ * @msg_seqnum: Message sequence number
+ * @notify_entry: Entry into list of kernel-generated notifications
+ * @i_payload: Current relative index of start of payload
+ * @n_payload: Total number of bytes needed for payload
+ * @n_parts: Number of parts
+ * @parts: Array of iovecs that make up the whole message
+ * @meta_proc: Process metadata of the sender (or NULL if empty)
+ * @meta_conn: Connection metadata of the sender (or NULL if empty)
+ * @bloom_filter: Pointer to the bloom-item in @msg, or NULL
+ * @dst_name: Pointer to the dst-name-item in @msg, or NULL
+ * @notify: Pointer to the notification item in @msg, or NULL
+ *
+ * The kdbus_staging object is a temporary staging area to import user-supplied
+ * messages into the kernel. It is only used during SEND and dropped once the
+ * message is queued. Any data that cannot be collected during SEND, is
+ * collected in a kdbus_gaps object and attached to the message queue.
+ */
+struct kdbus_staging {
+ struct kdbus_msg *msg;
+ struct kdbus_gaps *gaps;
+ u64 msg_seqnum;
+ struct list_head notify_entry;
+
+ /* crafted iovecs to copy the message */
+ size_t i_payload;
+ size_t n_payload;
+ size_t n_parts;
+ struct iovec *parts;
+
+ /* metadata state */
+ struct kdbus_meta_proc *meta_proc;
+ struct kdbus_meta_conn *meta_conn;
+
+ /* cached pointers into @msg */
+ const struct kdbus_bloom_filter *bloom_filter;
+ const char *dst_name;
+ struct kdbus_item *notify;
+};
+
+struct kdbus_staging *kdbus_staging_new_kernel(struct kdbus_bus *bus,
+ u64 dst, u64 cookie_timeout,
+ size_t it_size, size_t it_type);
+struct kdbus_staging *kdbus_staging_new_user(struct kdbus_bus *bus,
+ struct kdbus_cmd_send *cmd,
+ struct kdbus_msg *msg);
+struct kdbus_staging *kdbus_staging_free(struct kdbus_staging *staging);
+struct kdbus_pool_slice *kdbus_staging_emit(struct kdbus_staging *staging,
+ struct kdbus_conn *src,
+ struct kdbus_conn *dst);
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/audit.h>
+#include <linux/capability.h>
+#include <linux/cgroup.h>
+#include <linux/cred.h>
+#include <linux/file.h>
+#include <linux/fs_struct.h>
+#include <linux/init.h>
+#include <linux/kref.h>
+#include <linux/mount.h>
+#include <linux/mutex.h>
+#include <linux/proc_fs.h>
+#include <linux/sched.h>
+#include <linux/security.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/uidgid.h>
+#include <linux/uio.h>
+#include <linux/user_namespace.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "endpoint.h"
+#include "item.h"
+#include "message.h"
+#include "metadata.h"
+#include "names.h"
+
+/**
+ * struct kdbus_meta_proc - Process metadata
+ * @kref: Reference counting
+ * @lock: Object lock
+ * @collected: Bitmask of collected items
+ * @valid: Bitmask of collected and valid items
+ * @cred: Credentials
+ * @pid: PID of process
+ * @tgid: TGID of process
+ * @ppid: PPID of process
+ * @tid_comm: TID comm line
+ * @pid_comm: PID comm line
+ * @exe_path: Executable path
+ * @root_path: Root-FS path
+ * @cmdline: Command-line
+ * @cgroup: Full cgroup path
+ * @seclabel: Seclabel
+ * @audit_loginuid: Audit login-UID
+ * @audit_sessionid: Audit session-ID
+ */
+struct kdbus_meta_proc {
+ struct kref kref;
+ struct mutex lock;
+ u64 collected;
+ u64 valid;
+
+ /* KDBUS_ITEM_CREDS */
+ /* KDBUS_ITEM_AUXGROUPS */
+ /* KDBUS_ITEM_CAPS */
+ const struct cred *cred;
+
+ /* KDBUS_ITEM_PIDS */
+ struct pid *pid;
+ struct pid *tgid;
+ struct pid *ppid;
+
+ /* KDBUS_ITEM_TID_COMM */
+ char tid_comm[TASK_COMM_LEN];
+ /* KDBUS_ITEM_PID_COMM */
+ char pid_comm[TASK_COMM_LEN];
+
+ /* KDBUS_ITEM_EXE */
+ struct path exe_path;
+ struct path root_path;
+
+ /* KDBUS_ITEM_CMDLINE */
+ char *cmdline;
+
+ /* KDBUS_ITEM_CGROUP */
+ char *cgroup;
+
+ /* KDBUS_ITEM_SECLABEL */
+ char *seclabel;
+
+ /* KDBUS_ITEM_AUDIT */
+ kuid_t audit_loginuid;
+ unsigned int audit_sessionid;
+};
+
+/**
+ * struct kdbus_meta_conn
+ * @kref: Reference counting
+ * @lock: Object lock
+ * @collected: Bitmask of collected items
+ * @valid: Bitmask of collected and valid items
+ * @ts: Timestamp values
+ * @owned_names_items: Serialized items for owned names
+ * @owned_names_size: Size of @owned_names_items
+ * @conn_description: Connection description
+ */
+struct kdbus_meta_conn {
+ struct kref kref;
+ struct mutex lock;
+ u64 collected;
+ u64 valid;
+
+ /* KDBUS_ITEM_TIMESTAMP */
+ struct kdbus_timestamp ts;
+
+ /* KDBUS_ITEM_OWNED_NAME */
+ struct kdbus_item *owned_names_items;
+ size_t owned_names_size;
+
+ /* KDBUS_ITEM_CONN_DESCRIPTION */
+ char *conn_description;
+};
+
+/* fixed size equivalent of "kdbus_caps" */
+struct kdbus_meta_caps {
+ u32 last_cap;
+ struct {
+ u32 caps[_KERNEL_CAPABILITY_U32S];
+ } set[4];
+};
+
+/**
+ * kdbus_meta_proc_new() - Create process metadata object
+ *
+ * Return: Pointer to new object on success, ERR_PTR on failure.
+ */
+struct kdbus_meta_proc *kdbus_meta_proc_new(void)
+{
+ struct kdbus_meta_proc *mp;
+
+ mp = kzalloc(sizeof(*mp), GFP_KERNEL);
+ if (!mp)
+ return ERR_PTR(-ENOMEM);
+
+ kref_init(&mp->kref);
+ mutex_init(&mp->lock);
+
+ return mp;
+}
+
+static void kdbus_meta_proc_free(struct kref *kref)
+{
+ struct kdbus_meta_proc *mp = container_of(kref, struct kdbus_meta_proc,
+ kref);
+
+ path_put(&mp->exe_path);
+ path_put(&mp->root_path);
+ if (mp->cred)
+ put_cred(mp->cred);
+ put_pid(mp->ppid);
+ put_pid(mp->tgid);
+ put_pid(mp->pid);
+
+ kfree(mp->seclabel);
+ kfree(mp->cmdline);
+ kfree(mp->cgroup);
+ kfree(mp);
+}
+
+/**
+ * kdbus_meta_proc_ref() - Gain reference
+ * @mp: Process metadata object
+ *
+ * Return: @mp is returned
+ */
+struct kdbus_meta_proc *kdbus_meta_proc_ref(struct kdbus_meta_proc *mp)
+{
+ if (mp)
+ kref_get(&mp->kref);
+ return mp;
+}
+
+/**
+ * kdbus_meta_proc_unref() - Drop reference
+ * @mp: Process metadata object
+ *
+ * Return: NULL
+ */
+struct kdbus_meta_proc *kdbus_meta_proc_unref(struct kdbus_meta_proc *mp)
+{
+ if (mp)
+ kref_put(&mp->kref, kdbus_meta_proc_free);
+ return NULL;
+}
+
+static void kdbus_meta_proc_collect_pids(struct kdbus_meta_proc *mp)
+{
+ struct task_struct *parent;
+
+ mp->pid = get_pid(task_pid(current));
+ mp->tgid = get_pid(task_tgid(current));
+
+ rcu_read_lock();
+ parent = rcu_dereference(current->real_parent);
+ mp->ppid = get_pid(task_tgid(parent));
+ rcu_read_unlock();
+
+ mp->valid |= KDBUS_ATTACH_PIDS;
+}
+
+static void kdbus_meta_proc_collect_tid_comm(struct kdbus_meta_proc *mp)
+{
+ get_task_comm(mp->tid_comm, current);
+ mp->valid |= KDBUS_ATTACH_TID_COMM;
+}
+
+static void kdbus_meta_proc_collect_pid_comm(struct kdbus_meta_proc *mp)
+{
+ get_task_comm(mp->pid_comm, current->group_leader);
+ mp->valid |= KDBUS_ATTACH_PID_COMM;
+}
+
+static void kdbus_meta_proc_collect_exe(struct kdbus_meta_proc *mp)
+{
+ struct file *exe_file;
+
+ rcu_read_lock();
+ exe_file = rcu_dereference(current->mm->exe_file);
+ if (exe_file) {
+ mp->exe_path = exe_file->f_path;
+ path_get(&mp->exe_path);
+ get_fs_root(current->fs, &mp->root_path);
+ mp->valid |= KDBUS_ATTACH_EXE;
+ }
+ rcu_read_unlock();
+}
+
+static int kdbus_meta_proc_collect_cmdline(struct kdbus_meta_proc *mp)
+{
+ struct mm_struct *mm = current->mm;
+ char *cmdline;
+
+ if (mm->arg_start >= mm->arg_end)
+ return 0;
+
+ cmdline = strndup_user((const char __user *)mm->arg_start,
+ mm->arg_end - mm->arg_start);
+ if (IS_ERR(cmdline))
+ return PTR_ERR(cmdline);
+
+ mp->cmdline = cmdline;
+ mp->valid |= KDBUS_ATTACH_CMDLINE;
+
+ return 0;
+}
+
+static int kdbus_meta_proc_collect_cgroup(struct kdbus_meta_proc *mp)
+{
+#ifdef CONFIG_CGROUPS
+ void *page;
+
+ page = (void *)__get_free_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ if (task_cgroup_path(current, page, PAGE_SIZE) < PAGE_SIZE) {
+ mp->cgroup = kstrdup(page, GFP_KERNEL);
+ if (!mp->cgroup) {
+ free_page((unsigned long)page);
+ return -ENOMEM;
+ }
+ }
+
+ free_page((unsigned long)page);
+ mp->valid |= KDBUS_ATTACH_CGROUP;
+#endif
+
+ return 0;
+}
+
+static int kdbus_meta_proc_collect_seclabel(struct kdbus_meta_proc *mp)
+{
+#ifdef CONFIG_SECURITY
+ char *ctx = NULL;
+ u32 sid, len;
+ int ret;
+
+ security_task_getsecid(current, &sid);
+ ret = security_secid_to_secctx(sid, &ctx, &len);
+ if (ret < 0) {
+ /*
+ * EOPNOTSUPP means no security module is active,
+ * lets skip adding the seclabel then. This effectively
+ * drops the SECLABEL item.
+ */
+ return (ret == -EOPNOTSUPP) ? 0 : ret;
+ }
+
+ mp->seclabel = kstrdup(ctx, GFP_KERNEL);
+ security_release_secctx(ctx, len);
+ if (!mp->seclabel)
+ return -ENOMEM;
+
+ mp->valid |= KDBUS_ATTACH_SECLABEL;
+#endif
+
+ return 0;
+}
+
+static void kdbus_meta_proc_collect_audit(struct kdbus_meta_proc *mp)
+{
+#ifdef CONFIG_AUDITSYSCALL
+ mp->audit_loginuid = audit_get_loginuid(current);
+ mp->audit_sessionid = audit_get_sessionid(current);
+ mp->valid |= KDBUS_ATTACH_AUDIT;
+#endif
+}
+
+/**
+ * kdbus_meta_proc_collect() - Collect process metadata
+ * @mp: Process metadata object
+ * @what: Attach flags to collect
+ *
+ * This collects process metadata from current and saves it in @mp.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_meta_proc_collect(struct kdbus_meta_proc *mp, u64 what)
+{
+ int ret;
+
+ if (!mp || !(what & (KDBUS_ATTACH_CREDS |
+ KDBUS_ATTACH_PIDS |
+ KDBUS_ATTACH_AUXGROUPS |
+ KDBUS_ATTACH_TID_COMM |
+ KDBUS_ATTACH_PID_COMM |
+ KDBUS_ATTACH_EXE |
+ KDBUS_ATTACH_CMDLINE |
+ KDBUS_ATTACH_CGROUP |
+ KDBUS_ATTACH_CAPS |
+ KDBUS_ATTACH_SECLABEL |
+ KDBUS_ATTACH_AUDIT)))
+ return 0;
+
+ mutex_lock(&mp->lock);
+
+ /* creds, auxgrps and caps share "struct cred" as context */
+ {
+ const u64 m_cred = KDBUS_ATTACH_CREDS |
+ KDBUS_ATTACH_AUXGROUPS |
+ KDBUS_ATTACH_CAPS;
+
+ if ((what & m_cred) && !(mp->collected & m_cred)) {
+ mp->cred = get_current_cred();
+ mp->valid |= m_cred;
+ mp->collected |= m_cred;
+ }
+ }
+
+ if ((what & KDBUS_ATTACH_PIDS) &&
+ !(mp->collected & KDBUS_ATTACH_PIDS)) {
+ kdbus_meta_proc_collect_pids(mp);
+ mp->collected |= KDBUS_ATTACH_PIDS;
+ }
+
+ if ((what & KDBUS_ATTACH_TID_COMM) &&
+ !(mp->collected & KDBUS_ATTACH_TID_COMM)) {
+ kdbus_meta_proc_collect_tid_comm(mp);
+ mp->collected |= KDBUS_ATTACH_TID_COMM;
+ }
+
+ if ((what & KDBUS_ATTACH_PID_COMM) &&
+ !(mp->collected & KDBUS_ATTACH_PID_COMM)) {
+ kdbus_meta_proc_collect_pid_comm(mp);
+ mp->collected |= KDBUS_ATTACH_PID_COMM;
+ }
+
+ if ((what & KDBUS_ATTACH_EXE) &&
+ !(mp->collected & KDBUS_ATTACH_EXE)) {
+ kdbus_meta_proc_collect_exe(mp);
+ mp->collected |= KDBUS_ATTACH_EXE;
+ }
+
+ if ((what & KDBUS_ATTACH_CMDLINE) &&
+ !(mp->collected & KDBUS_ATTACH_CMDLINE)) {
+ ret = kdbus_meta_proc_collect_cmdline(mp);
+ if (ret < 0)
+ goto exit_unlock;
+ mp->collected |= KDBUS_ATTACH_CMDLINE;
+ }
+
+ if ((what & KDBUS_ATTACH_CGROUP) &&
+ !(mp->collected & KDBUS_ATTACH_CGROUP)) {
+ ret = kdbus_meta_proc_collect_cgroup(mp);
+ if (ret < 0)
+ goto exit_unlock;
+ mp->collected |= KDBUS_ATTACH_CGROUP;
+ }
+
+ if ((what & KDBUS_ATTACH_SECLABEL) &&
+ !(mp->collected & KDBUS_ATTACH_SECLABEL)) {
+ ret = kdbus_meta_proc_collect_seclabel(mp);
+ if (ret < 0)
+ goto exit_unlock;
+ mp->collected |= KDBUS_ATTACH_SECLABEL;
+ }
+
+ if ((what & KDBUS_ATTACH_AUDIT) &&
+ !(mp->collected & KDBUS_ATTACH_AUDIT)) {
+ kdbus_meta_proc_collect_audit(mp);
+ mp->collected |= KDBUS_ATTACH_AUDIT;
+ }
+
+ ret = 0;
+
+exit_unlock:
+ mutex_unlock(&mp->lock);
+ return ret;
+}
+
+/**
+ * kdbus_meta_fake_new() - Create fake metadata object
+ *
+ * Return: Pointer to new object on success, ERR_PTR on failure.
+ */
+struct kdbus_meta_fake *kdbus_meta_fake_new(void)
+{
+ struct kdbus_meta_fake *mf;
+
+ mf = kzalloc(sizeof(*mf), GFP_KERNEL);
+ if (!mf)
+ return ERR_PTR(-ENOMEM);
+
+ return mf;
+}
+
+/**
+ * kdbus_meta_fake_free() - Free fake metadata object
+ * @mf: Fake metadata object
+ *
+ * Return: NULL
+ */
+struct kdbus_meta_fake *kdbus_meta_fake_free(struct kdbus_meta_fake *mf)
+{
+ if (mf) {
+ put_pid(mf->ppid);
+ put_pid(mf->tgid);
+ put_pid(mf->pid);
+ kfree(mf->seclabel);
+ kfree(mf);
+ }
+
+ return NULL;
+}
+
+/**
+ * kdbus_meta_fake_collect() - Fill fake metadata from faked credentials
+ * @mf: Fake metadata object
+ * @creds: Creds to set, may be %NULL
+ * @pids: PIDs to set, may be %NULL
+ * @seclabel: Seclabel to set, may be %NULL
+ *
+ * This function takes information stored in @creds, @pids and @seclabel and
+ * resolves them to kernel-representations, if possible. This call uses the
+ * current task's namespaces to resolve the given information.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_meta_fake_collect(struct kdbus_meta_fake *mf,
+ const struct kdbus_creds *creds,
+ const struct kdbus_pids *pids,
+ const char *seclabel)
+{
+ if (mf->valid)
+ return -EALREADY;
+
+ if (creds) {
+ struct user_namespace *ns = current_user_ns();
+
+ mf->uid = make_kuid(ns, creds->uid);
+ mf->euid = make_kuid(ns, creds->euid);
+ mf->suid = make_kuid(ns, creds->suid);
+ mf->fsuid = make_kuid(ns, creds->fsuid);
+
+ mf->gid = make_kgid(ns, creds->gid);
+ mf->egid = make_kgid(ns, creds->egid);
+ mf->sgid = make_kgid(ns, creds->sgid);
+ mf->fsgid = make_kgid(ns, creds->fsgid);
+
+ if ((creds->uid != (uid_t)-1 && !uid_valid(mf->uid)) ||
+ (creds->euid != (uid_t)-1 && !uid_valid(mf->euid)) ||
+ (creds->suid != (uid_t)-1 && !uid_valid(mf->suid)) ||
+ (creds->fsuid != (uid_t)-1 && !uid_valid(mf->fsuid)) ||
+ (creds->gid != (gid_t)-1 && !gid_valid(mf->gid)) ||
+ (creds->egid != (gid_t)-1 && !gid_valid(mf->egid)) ||
+ (creds->sgid != (gid_t)-1 && !gid_valid(mf->sgid)) ||
+ (creds->fsgid != (gid_t)-1 && !gid_valid(mf->fsgid)))
+ return -EINVAL;
+
+ mf->valid |= KDBUS_ATTACH_CREDS;
+ }
+
+ if (pids) {
+ mf->pid = get_pid(find_vpid(pids->tid));
+ mf->tgid = get_pid(find_vpid(pids->pid));
+ mf->ppid = get_pid(find_vpid(pids->ppid));
+
+ if ((pids->tid != 0 && !mf->pid) ||
+ (pids->pid != 0 && !mf->tgid) ||
+ (pids->ppid != 0 && !mf->ppid)) {
+ put_pid(mf->pid);
+ put_pid(mf->tgid);
+ put_pid(mf->ppid);
+ mf->pid = NULL;
+ mf->tgid = NULL;
+ mf->ppid = NULL;
+ return -EINVAL;
+ }
+
+ mf->valid |= KDBUS_ATTACH_PIDS;
+ }
+
+ if (seclabel) {
+ mf->seclabel = kstrdup(seclabel, GFP_KERNEL);
+ if (!mf->seclabel)
+ return -ENOMEM;
+
+ mf->valid |= KDBUS_ATTACH_SECLABEL;
+ }
+
+ return 0;
+}
+
+/**
+ * kdbus_meta_conn_new() - Create connection metadata object
+ *
+ * Return: Pointer to new object on success, ERR_PTR on failure.
+ */
+struct kdbus_meta_conn *kdbus_meta_conn_new(void)
+{
+ struct kdbus_meta_conn *mc;
+
+ mc = kzalloc(sizeof(*mc), GFP_KERNEL);
+ if (!mc)
+ return ERR_PTR(-ENOMEM);
+
+ kref_init(&mc->kref);
+ mutex_init(&mc->lock);
+
+ return mc;
+}
+
+static void kdbus_meta_conn_free(struct kref *kref)
+{
+ struct kdbus_meta_conn *mc =
+ container_of(kref, struct kdbus_meta_conn, kref);
+
+ kfree(mc->conn_description);
+ kfree(mc->owned_names_items);
+ kfree(mc);
+}
+
+/**
+ * kdbus_meta_conn_ref() - Gain reference
+ * @mc: Connection metadata object
+ */
+struct kdbus_meta_conn *kdbus_meta_conn_ref(struct kdbus_meta_conn *mc)
+{
+ if (mc)
+ kref_get(&mc->kref);
+ return mc;
+}
+
+/**
+ * kdbus_meta_conn_unref() - Drop reference
+ * @mc: Connection metadata object
+ */
+struct kdbus_meta_conn *kdbus_meta_conn_unref(struct kdbus_meta_conn *mc)
+{
+ if (mc)
+ kref_put(&mc->kref, kdbus_meta_conn_free);
+ return NULL;
+}
+
+static void kdbus_meta_conn_collect_timestamp(struct kdbus_meta_conn *mc,
+ u64 msg_seqnum)
+{
+ mc->ts.monotonic_ns = ktime_get_ns();
+ mc->ts.realtime_ns = ktime_get_real_ns();
+
+ if (msg_seqnum)
+ mc->ts.seqnum = msg_seqnum;
+
+ mc->valid |= KDBUS_ATTACH_TIMESTAMP;
+}
+
+static int kdbus_meta_conn_collect_names(struct kdbus_meta_conn *mc,
+ struct kdbus_conn *conn)
+{
+ const struct kdbus_name_owner *owner;
+ struct kdbus_item *item;
+ size_t slen, size;
+
+ lockdep_assert_held(&conn->ep->bus->name_registry->rwlock);
+
+ size = 0;
+ /* open-code length calculation to avoid final padding */
+ list_for_each_entry(owner, &conn->names_list, conn_entry)
+ if (!(owner->flags & KDBUS_NAME_IN_QUEUE))
+ size = KDBUS_ALIGN8(size) + KDBUS_ITEM_HEADER_SIZE +
+ sizeof(struct kdbus_name) +
+ strlen(owner->name->name) + 1;
+
+ if (!size)
+ return 0;
+
+ /* make sure we include zeroed padding for convenience helpers */
+ item = kmalloc(KDBUS_ALIGN8(size), GFP_KERNEL);
+ if (!item)
+ return -ENOMEM;
+
+ mc->owned_names_items = item;
+ mc->owned_names_size = size;
+
+ list_for_each_entry(owner, &conn->names_list, conn_entry) {
+ if (owner->flags & KDBUS_NAME_IN_QUEUE)
+ continue;
+
+ slen = strlen(owner->name->name) + 1;
+ kdbus_item_set(item, KDBUS_ITEM_OWNED_NAME, NULL,
+ sizeof(struct kdbus_name) + slen);
+ item->name.flags = owner->flags;
+ memcpy(item->name.name, owner->name->name, slen);
+ item = KDBUS_ITEM_NEXT(item);
+ }
+
+ /* sanity check: the buffer should be completely written now */
+ WARN_ON((u8 *)item !=
+ (u8 *)mc->owned_names_items + KDBUS_ALIGN8(size));
+
+ mc->valid |= KDBUS_ATTACH_NAMES;
+ return 0;
+}
+
+static int kdbus_meta_conn_collect_description(struct kdbus_meta_conn *mc,
+ struct kdbus_conn *conn)
+{
+ if (!conn->description)
+ return 0;
+
+ mc->conn_description = kstrdup(conn->description, GFP_KERNEL);
+ if (!mc->conn_description)
+ return -ENOMEM;
+
+ mc->valid |= KDBUS_ATTACH_CONN_DESCRIPTION;
+ return 0;
+}
+
+/**
+ * kdbus_meta_conn_collect() - Collect connection metadata
+ * @mc: Message metadata object
+ * @conn: Connection to collect data from
+ * @msg_seqnum: Sequence number of the message to send
+ * @what: Attach flags to collect
+ *
+ * This collects connection metadata from @msg_seqnum and @conn and saves it
+ * in @mc.
+ *
+ * If KDBUS_ATTACH_NAMES is set in @what and @conn is non-NULL, the caller must
+ * hold the name-registry read-lock of conn->ep->bus->registry.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_meta_conn_collect(struct kdbus_meta_conn *mc,
+ struct kdbus_conn *conn,
+ u64 msg_seqnum, u64 what)
+{
+ int ret;
+
+ if (!mc || !(what & (KDBUS_ATTACH_TIMESTAMP |
+ KDBUS_ATTACH_NAMES |
+ KDBUS_ATTACH_CONN_DESCRIPTION)))
+ return 0;
+
+ mutex_lock(&mc->lock);
+
+ if (msg_seqnum && (what & KDBUS_ATTACH_TIMESTAMP) &&
+ !(mc->collected & KDBUS_ATTACH_TIMESTAMP)) {
+ kdbus_meta_conn_collect_timestamp(mc, msg_seqnum);
+ mc->collected |= KDBUS_ATTACH_TIMESTAMP;
+ }
+
+ if (conn && (what & KDBUS_ATTACH_NAMES) &&
+ !(mc->collected & KDBUS_ATTACH_NAMES)) {
+ ret = kdbus_meta_conn_collect_names(mc, conn);
+ if (ret < 0)
+ goto exit_unlock;
+ mc->collected |= KDBUS_ATTACH_NAMES;
+ }
+
+ if (conn && (what & KDBUS_ATTACH_CONN_DESCRIPTION) &&
+ !(mc->collected & KDBUS_ATTACH_CONN_DESCRIPTION)) {
+ ret = kdbus_meta_conn_collect_description(mc, conn);
+ if (ret < 0)
+ goto exit_unlock;
+ mc->collected |= KDBUS_ATTACH_CONN_DESCRIPTION;
+ }
+
+ ret = 0;
+
+exit_unlock:
+ mutex_unlock(&mc->lock);
+ return ret;
+}
+
+static void kdbus_meta_export_caps(struct kdbus_meta_caps *out,
+ const struct kdbus_meta_proc *mp,
+ struct user_namespace *user_ns)
+{
+ struct user_namespace *iter;
+ const struct cred *cred = mp->cred;
+ bool parent = false, owner = false;
+ int i;
+
+ /*
+ * This translates the effective capabilities of 'cred' into the given
+ * user-namespace. If the given user-namespace is a child-namespace of
+ * the user-namespace of 'cred', the mask can be copied verbatim. If
+ * not, the mask is cleared.
+ * There's one exception: If 'cred' is the owner of any user-namespace
+ * in the path between the given user-namespace and the user-namespace
+ * of 'cred', then it has all effective capabilities set. This means,
+ * the user who created a user-namespace always has all effective
+ * capabilities in any child namespaces. Note that this is based on the
+ * uid of the namespace creator, not the task hierarchy.
+ */
+ for (iter = user_ns; iter; iter = iter->parent) {
+ if (iter == cred->user_ns) {
+ parent = true;
+ break;
+ }
+
+ if (iter == &init_user_ns)
+ break;
+
+ if ((iter->parent == cred->user_ns) &&
+ uid_eq(iter->owner, cred->euid)) {
+ owner = true;
+ break;
+ }
+ }
+
+ out->last_cap = CAP_LAST_CAP;
+
+ CAP_FOR_EACH_U32(i) {
+ if (parent) {
+ out->set[0].caps[i] = cred->cap_inheritable.cap[i];
+ out->set[1].caps[i] = cred->cap_permitted.cap[i];
+ out->set[2].caps[i] = cred->cap_effective.cap[i];
+ out->set[3].caps[i] = cred->cap_bset.cap[i];
+ } else if (owner) {
+ out->set[0].caps[i] = 0U;
+ out->set[1].caps[i] = ~0U;
+ out->set[2].caps[i] = ~0U;
+ out->set[3].caps[i] = ~0U;
+ } else {
+ out->set[0].caps[i] = 0U;
+ out->set[1].caps[i] = 0U;
+ out->set[2].caps[i] = 0U;
+ out->set[3].caps[i] = 0U;
+ }
+ }
+
+ /* clear unused bits */
+ for (i = 0; i < 4; i++)
+ out->set[i].caps[CAP_TO_INDEX(CAP_LAST_CAP)] &=
+ CAP_LAST_U32_VALID_MASK;
+}
+
+/* This is equivalent to from_kuid_munged(), but maps INVALID_UID to itself */
+static uid_t kdbus_from_kuid_keep(struct user_namespace *ns, kuid_t uid)
+{
+ return uid_valid(uid) ? from_kuid_munged(ns, uid) : ((uid_t)-1);
+}
+
+/* This is equivalent to from_kgid_munged(), but maps INVALID_GID to itself */
+static gid_t kdbus_from_kgid_keep(struct user_namespace *ns, kgid_t gid)
+{
+ return gid_valid(gid) ? from_kgid_munged(ns, gid) : ((gid_t)-1);
+}
+
+struct kdbus_meta_staging {
+ const struct kdbus_meta_proc *mp;
+ const struct kdbus_meta_fake *mf;
+ const struct kdbus_meta_conn *mc;
+ const struct kdbus_conn *conn;
+ u64 mask;
+
+ void *exe;
+ const char *exe_path;
+};
+
+static size_t kdbus_meta_measure(struct kdbus_meta_staging *staging)
+{
+ const struct kdbus_meta_proc *mp = staging->mp;
+ const struct kdbus_meta_fake *mf = staging->mf;
+ const struct kdbus_meta_conn *mc = staging->mc;
+ const u64 mask = staging->mask;
+ size_t size = 0;
+
+ /* process metadata */
+
+ if (mf && (mask & KDBUS_ATTACH_CREDS))
+ size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_creds));
+ else if (mp && (mask & KDBUS_ATTACH_CREDS))
+ size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_creds));
+
+ if (mf && (mask & KDBUS_ATTACH_PIDS))
+ size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_pids));
+ else if (mp && (mask & KDBUS_ATTACH_PIDS))
+ size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_pids));
+
+ if (mp && (mask & KDBUS_ATTACH_AUXGROUPS))
+ size += KDBUS_ITEM_SIZE(mp->cred->group_info->ngroups *
+ sizeof(u64));
+
+ if (mp && (mask & KDBUS_ATTACH_TID_COMM))
+ size += KDBUS_ITEM_SIZE(strlen(mp->tid_comm) + 1);
+
+ if (mp && (mask & KDBUS_ATTACH_PID_COMM))
+ size += KDBUS_ITEM_SIZE(strlen(mp->pid_comm) + 1);
+
+ if (staging->exe_path && (mask & KDBUS_ATTACH_EXE))
+ size += KDBUS_ITEM_SIZE(strlen(staging->exe_path) + 1);
+
+ if (mp && (mask & KDBUS_ATTACH_CMDLINE))
+ size += KDBUS_ITEM_SIZE(strlen(mp->cmdline) + 1);
+
+ if (mp && (mask & KDBUS_ATTACH_CGROUP))
+ size += KDBUS_ITEM_SIZE(strlen(mp->cgroup) + 1);
+
+ if (mp && (mask & KDBUS_ATTACH_CAPS))
+ size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_meta_caps));
+
+ if (mf && (mask & KDBUS_ATTACH_SECLABEL))
+ size += KDBUS_ITEM_SIZE(strlen(mf->seclabel) + 1);
+ else if (mp && (mask & KDBUS_ATTACH_SECLABEL))
+ size += KDBUS_ITEM_SIZE(strlen(mp->seclabel) + 1);
+
+ if (mp && (mask & KDBUS_ATTACH_AUDIT))
+ size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_audit));
+
+ /* connection metadata */
+
+ if (mc && (mask & KDBUS_ATTACH_NAMES))
+ size += KDBUS_ALIGN8(mc->owned_names_size);
+
+ if (mc && (mask & KDBUS_ATTACH_CONN_DESCRIPTION))
+ size += KDBUS_ITEM_SIZE(strlen(mc->conn_description) + 1);
+
+ if (mc && (mask & KDBUS_ATTACH_TIMESTAMP))
+ size += KDBUS_ITEM_SIZE(sizeof(struct kdbus_timestamp));
+
+ return size;
+}
+
+static struct kdbus_item *kdbus_write_head(struct kdbus_item **iter,
+ u64 type, u64 size)
+{
+ struct kdbus_item *item = *iter;
+ size_t padding;
+
+ item->type = type;
+ item->size = KDBUS_ITEM_HEADER_SIZE + size;
+
+ /* clear padding */
+ padding = KDBUS_ALIGN8(item->size) - item->size;
+ if (padding)
+ memset(item->data + size, 0, padding);
+
+ *iter = KDBUS_ITEM_NEXT(item);
+ return item;
+}
+
+static struct kdbus_item *kdbus_write_full(struct kdbus_item **iter,
+ u64 type, u64 size, const void *data)
+{
+ struct kdbus_item *item;
+
+ item = kdbus_write_head(iter, type, size);
+ memcpy(item->data, data, size);
+ return item;
+}
+
+static size_t kdbus_meta_write(struct kdbus_meta_staging *staging, void *mem,
+ size_t size)
+{
+ struct user_namespace *user_ns = staging->conn->cred->user_ns;
+ struct pid_namespace *pid_ns = ns_of_pid(staging->conn->pid);
+ struct kdbus_item *item = NULL, *items = mem;
+ u8 *end, *owned_names_end = NULL;
+
+ /* process metadata */
+
+ if (staging->mf && (staging->mask & KDBUS_ATTACH_CREDS)) {
+ const struct kdbus_meta_fake *mf = staging->mf;
+
+ item = kdbus_write_head(&items, KDBUS_ITEM_CREDS,
+ sizeof(struct kdbus_creds));
+ item->creds = (struct kdbus_creds){
+ .uid = kdbus_from_kuid_keep(user_ns, mf->uid),
+ .euid = kdbus_from_kuid_keep(user_ns, mf->euid),
+ .suid = kdbus_from_kuid_keep(user_ns, mf->suid),
+ .fsuid = kdbus_from_kuid_keep(user_ns, mf->fsuid),
+ .gid = kdbus_from_kgid_keep(user_ns, mf->gid),
+ .egid = kdbus_from_kgid_keep(user_ns, mf->egid),
+ .sgid = kdbus_from_kgid_keep(user_ns, mf->sgid),
+ .fsgid = kdbus_from_kgid_keep(user_ns, mf->fsgid),
+ };
+ } else if (staging->mp && (staging->mask & KDBUS_ATTACH_CREDS)) {
+ const struct cred *c = staging->mp->cred;
+
+ item = kdbus_write_head(&items, KDBUS_ITEM_CREDS,
+ sizeof(struct kdbus_creds));
+ item->creds = (struct kdbus_creds){
+ .uid = kdbus_from_kuid_keep(user_ns, c->uid),
+ .euid = kdbus_from_kuid_keep(user_ns, c->euid),
+ .suid = kdbus_from_kuid_keep(user_ns, c->suid),
+ .fsuid = kdbus_from_kuid_keep(user_ns, c->fsuid),
+ .gid = kdbus_from_kgid_keep(user_ns, c->gid),
+ .egid = kdbus_from_kgid_keep(user_ns, c->egid),
+ .sgid = kdbus_from_kgid_keep(user_ns, c->sgid),
+ .fsgid = kdbus_from_kgid_keep(user_ns, c->fsgid),
+ };
+ }
+
+ if (staging->mf && (staging->mask & KDBUS_ATTACH_PIDS)) {
+ item = kdbus_write_head(&items, KDBUS_ITEM_PIDS,
+ sizeof(struct kdbus_pids));
+ item->pids = (struct kdbus_pids){
+ .pid = pid_nr_ns(staging->mf->tgid, pid_ns),
+ .tid = pid_nr_ns(staging->mf->pid, pid_ns),
+ .ppid = pid_nr_ns(staging->mf->ppid, pid_ns),
+ };
+ } else if (staging->mp && (staging->mask & KDBUS_ATTACH_PIDS)) {
+ item = kdbus_write_head(&items, KDBUS_ITEM_PIDS,
+ sizeof(struct kdbus_pids));
+ item->pids = (struct kdbus_pids){
+ .pid = pid_nr_ns(staging->mp->tgid, pid_ns),
+ .tid = pid_nr_ns(staging->mp->pid, pid_ns),
+ .ppid = pid_nr_ns(staging->mp->ppid, pid_ns),
+ };
+ }
+
+ if (staging->mp && (staging->mask & KDBUS_ATTACH_AUXGROUPS)) {
+ const struct group_info *info = staging->mp->cred->group_info;
+ size_t i;
+
+ item = kdbus_write_head(&items, KDBUS_ITEM_AUXGROUPS,
+ info->ngroups * sizeof(u64));
+ for (i = 0; i < info->ngroups; ++i)
+ item->data64[i] = from_kgid_munged(user_ns, info->gid[i]);
+ }
+
+ if (staging->mp && (staging->mask & KDBUS_ATTACH_TID_COMM))
+ item = kdbus_write_full(&items, KDBUS_ITEM_TID_COMM,
+ strlen(staging->mp->tid_comm) + 1,
+ staging->mp->tid_comm);
+
+ if (staging->mp && (staging->mask & KDBUS_ATTACH_PID_COMM))
+ item = kdbus_write_full(&items, KDBUS_ITEM_PID_COMM,
+ strlen(staging->mp->pid_comm) + 1,
+ staging->mp->pid_comm);
+
+ if (staging->exe_path && (staging->mask & KDBUS_ATTACH_EXE))
+ item = kdbus_write_full(&items, KDBUS_ITEM_EXE,
+ strlen(staging->exe_path) + 1,
+ staging->exe_path);
+
+ if (staging->mp && (staging->mask & KDBUS_ATTACH_CMDLINE))
+ item = kdbus_write_full(&items, KDBUS_ITEM_CMDLINE,
+ strlen(staging->mp->cmdline) + 1,
+ staging->mp->cmdline);
+
+ if (staging->mp && (staging->mask & KDBUS_ATTACH_CGROUP))
+ item = kdbus_write_full(&items, KDBUS_ITEM_CGROUP,
+ strlen(staging->mp->cgroup) + 1,
+ staging->mp->cgroup);
+
+ if (staging->mp && (staging->mask & KDBUS_ATTACH_CAPS)) {
+ item = kdbus_write_head(&items, KDBUS_ITEM_CAPS,
+ sizeof(struct kdbus_meta_caps));
+ kdbus_meta_export_caps((void*)&item->caps, staging->mp,
+ user_ns);
+ }
+
+ if (staging->mf && (staging->mask & KDBUS_ATTACH_SECLABEL))
+ item = kdbus_write_full(&items, KDBUS_ITEM_SECLABEL,
+ strlen(staging->mf->seclabel) + 1,
+ staging->mf->seclabel);
+ else if (staging->mp && (staging->mask & KDBUS_ATTACH_SECLABEL))
+ item = kdbus_write_full(&items, KDBUS_ITEM_SECLABEL,
+ strlen(staging->mp->seclabel) + 1,
+ staging->mp->seclabel);
+
+ if (staging->mp && (staging->mask & KDBUS_ATTACH_AUDIT)) {
+ item = kdbus_write_head(&items, KDBUS_ITEM_AUDIT,
+ sizeof(struct kdbus_audit));
+ item->audit = (struct kdbus_audit){
+ .loginuid = from_kuid(user_ns,
+ staging->mp->audit_loginuid),
+ .sessionid = staging->mp->audit_sessionid,
+ };
+ }
+
+ /* connection metadata */
+
+ if (staging->mc && (staging->mask & KDBUS_ATTACH_NAMES)) {
+ memcpy(items, staging->mc->owned_names_items,
+ KDBUS_ALIGN8(staging->mc->owned_names_size));
+ owned_names_end = (u8 *)items + staging->mc->owned_names_size;
+ items = (void *)KDBUS_ALIGN8((unsigned long)owned_names_end);
+ }
+
+ if (staging->mc && (staging->mask & KDBUS_ATTACH_CONN_DESCRIPTION))
+ item = kdbus_write_full(&items, KDBUS_ITEM_CONN_DESCRIPTION,
+ strlen(staging->mc->conn_description) + 1,
+ staging->mc->conn_description);
+
+ if (staging->mc && (staging->mask & KDBUS_ATTACH_TIMESTAMP))
+ item = kdbus_write_full(&items, KDBUS_ITEM_TIMESTAMP,
+ sizeof(staging->mc->ts),
+ &staging->mc->ts);
+
+ /*
+ * Return real size (minus trailing padding). In case of 'owned_names'
+ * we cannot deduce it from item->size, so treat it special.
+ */
+
+ if (items == (void *)KDBUS_ALIGN8((unsigned long)owned_names_end))
+ end = owned_names_end;
+ else if (item)
+ end = (u8 *)item + item->size;
+ else
+ end = mem;
+
+ WARN_ON((u8 *)items - (u8 *)mem != size);
+ WARN_ON((void *)KDBUS_ALIGN8((unsigned long)end) != (void *)items);
+
+ return end - (u8 *)mem;
+}
+
+int kdbus_meta_emit(struct kdbus_meta_proc *mp,
+ struct kdbus_meta_fake *mf,
+ struct kdbus_meta_conn *mc,
+ struct kdbus_conn *conn,
+ u64 mask,
+ struct kdbus_item **out_items,
+ size_t *out_size)
+{
+ struct kdbus_meta_staging staging = {};
+ struct kdbus_item *items = NULL;
+ size_t size = 0;
+ int ret;
+
+ if (WARN_ON(mf && mp))
+ mp = NULL;
+
+ staging.mp = mp;
+ staging.mf = mf;
+ staging.mc = mc;
+ staging.conn = conn;
+
+ /* get mask of valid items */
+ if (mf)
+ staging.mask |= mf->valid;
+ if (mp) {
+ mutex_lock(&mp->lock);
+ staging.mask |= mp->valid;
+ mutex_unlock(&mp->lock);
+ }
+ if (mc) {
+ mutex_lock(&mc->lock);
+ staging.mask |= mc->valid;
+ mutex_unlock(&mc->lock);
+ }
+
+ staging.mask &= mask;
+
+ if (!staging.mask) { /* bail out if nothing to do */
+ ret = 0;
+ goto exit;
+ }
+
+ /* EXE is special as it needs a temporary page to assemble */
+ if (mp && (staging.mask & KDBUS_ATTACH_EXE)) {
+ struct path p;
+
+ /*
+ * XXX: We need access to __d_path() so we can write the path
+ * relative to conn->root_path. Once upstream, we need
+ * EXPORT_SYMBOL(__d_path) or an equivalent of d_path() that
+ * takes the root path directly. Until then, we drop this item
+ * if the root-paths differ.
+ */
+
+ get_fs_root(current->fs, &p);
+ if (path_equal(&p, &conn->root_path)) {
+ staging.exe = (void *)__get_free_page(GFP_KERNEL);
+ if (!staging.exe) {
+ path_put(&p);
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ staging.exe_path = d_path(&mp->exe_path, staging.exe,
+ PAGE_SIZE);
+ if (IS_ERR(staging.exe_path)) {
+ path_put(&p);
+ ret = PTR_ERR(staging.exe_path);
+ goto exit;
+ }
+ }
+ path_put(&p);
+ }
+
+ size = kdbus_meta_measure(&staging);
+ if (!size) { /* bail out if nothing to do */
+ ret = 0;
+ goto exit;
+ }
+
+ items = kmalloc(size, GFP_KERNEL);
+ if (!items) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ size = kdbus_meta_write(&staging, items, size);
+ if (!size) {
+ kfree(items);
+ items = NULL;
+ }
+
+ ret = 0;
+
+exit:
+ if (staging.exe)
+ free_page((unsigned long)staging.exe);
+ if (ret >= 0) {
+ *out_items = items;
+ *out_size = size;
+ }
+ return ret;
+}
+
+enum {
+ KDBUS_META_PROC_NONE,
+ KDBUS_META_PROC_NORMAL,
+};
+
+static int max_hide_pid(struct vfsmount *mnt, void *arg)
+{
+ struct proc_fs_info *fs_info_out = arg;
+ struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
+ struct super_block *sb = mnt_path.dentry->d_sb;
+ struct proc_fs_info *fs_info_in = sb->s_fs_info;
+
+ if (strcmp("proc", sb->s_type->name) != 0)
+ return 0;
+
+ if (fs_info_out->hide_pid <= fs_info_in->hide_pid) {
+ fs_info_out->hide_pid = fs_info_in->hide_pid;
+ fs_info_out->pid_gid = fs_info_in->pid_gid;
+ }
+
+ return 0;
+}
+
+/**
+ * kdbus_proc_permission() - check /proc permissions on target pid
+ * @req_pid: pid of requestor
+ * @req_cred: credentials of requestor
+ * @target: target process
+ *
+ * This checks whether a process with credentials @cred can access
+ * information of @target in the namespace of @req_pid. This tries to
+ * follow /proc permissions, but is slightly more restrictive.
+ *
+ * Return: The /proc access level (KDBUS_META_PROC_*) is returned.
+ */
+static unsigned int kdbus_proc_permission(const struct pid *req_pid,
+ const struct cred *req_cred,
+ struct pid *target)
+{
+ struct task_struct *task = get_pid_task(req_pid, PIDTYPE_PID);
+ struct vfsmount *root_mnt;
+ struct path path;
+ unsigned int ret = KDBUS_META_PROC_NONE;
+ struct proc_fs_info fs_info;
+
+ if (!task)
+ return ret;
+
+ fs_info.hide_pid = 0;
+
+ get_fs_root(task->fs, &path);
+ root_mnt = collect_mounts(&path);
+ path_put(&path);
+
+ ret = PTR_ERR(root_mnt);
+ if (IS_ERR(root_mnt))
+ goto out;
+
+ iterate_mounts(max_hide_pid, &fs_info, root_mnt);
+
+ ret = KDBUS_META_PROC_NORMAL;
+ if (fs_info.hide_pid < 1)
+ goto out;
+
+ /* XXX: we need groups_search() exported for aux-groups */
+ if (gid_eq(req_cred->egid, fs_info.pid_gid))
+ goto out;
+
+ /*
+ * XXX: If ptrace_may_access(PTRACE_MODE_READ) is granted, you can
+ * overwrite hide_pid. However, ptrace_may_access() only supports
+ * checking 'current', hence, we cannot use this here. But we
+ * simply decide to not support this override, so no need to worry.
+ */
+
+ ret = KDBUS_META_PROC_NONE;
+out:
+ drop_collected_mounts(root_mnt);
+ put_task_struct(task);
+ return ret;
+}
+
+/**
+ * kdbus_meta_proc_mask() - calculate which metadata would be visible to
+ * a connection via /proc
+ * @prv_pid: pid of metadata provider
+ * @req_pid: pid of metadata requestor
+ * @req_cred: credentials of metadata reqeuestor
+ * @wanted: metadata that is requested
+ *
+ * This checks which metadata items of @prv_pid can be read via /proc by the
+ * requestor @req_pid.
+ *
+ * Return: Set of metadata flags the requestor can see (limited by @wanted).
+ */
+static u64 kdbus_meta_proc_mask(struct pid *prv_pid,
+ struct pid *req_pid,
+ const struct cred *req_cred,
+ u64 wanted)
+{
+ struct pid_namespace *prv_ns, *req_ns;
+ unsigned int proc;
+
+ prv_ns = ns_of_pid(prv_pid);
+ req_ns = ns_of_pid(req_pid);
+
+ /*
+ * If the sender is not visible in the receiver namespace, then the
+ * receiver cannot access the sender via its own procfs. Hence, we do
+ * not attach any additional metadata.
+ */
+ if (!pid_nr_ns(prv_pid, req_ns))
+ return 0;
+
+ /*
+ * If the pid-namespace of the receiver has hide_pid set, it cannot see
+ * any process but its own. We shortcut this /proc permission check if
+ * provider and requestor are the same. If not, we perform rather
+ * expensive /proc permission checks.
+ */
+ if (prv_pid == req_pid)
+ proc = KDBUS_META_PROC_NORMAL;
+ else
+ proc = kdbus_proc_permission(req_pid, req_cred, prv_pid);
+
+ /* you need /proc access to read standard process attributes */
+ if (proc < KDBUS_META_PROC_NORMAL)
+ wanted &= ~(KDBUS_ATTACH_TID_COMM |
+ KDBUS_ATTACH_PID_COMM |
+ KDBUS_ATTACH_SECLABEL |
+ KDBUS_ATTACH_CMDLINE |
+ KDBUS_ATTACH_CGROUP |
+ KDBUS_ATTACH_AUDIT |
+ KDBUS_ATTACH_CAPS |
+ KDBUS_ATTACH_EXE);
+
+ /* clear all non-/proc flags */
+ return wanted & (KDBUS_ATTACH_TID_COMM |
+ KDBUS_ATTACH_PID_COMM |
+ KDBUS_ATTACH_SECLABEL |
+ KDBUS_ATTACH_CMDLINE |
+ KDBUS_ATTACH_CGROUP |
+ KDBUS_ATTACH_AUDIT |
+ KDBUS_ATTACH_CAPS |
+ KDBUS_ATTACH_EXE);
+}
+
+/**
+ * kdbus_meta_get_mask() - calculate attach flags mask for metadata request
+ * @prv_pid: pid of metadata provider
+ * @prv_mask: mask of metadata the provide grants unchecked
+ * @req_pid: pid of metadata requestor
+ * @req_cred: credentials of metadata requestor
+ * @req_mask: mask of metadata that is requested
+ *
+ * This calculates the metadata items that the requestor @req_pid can access
+ * from the metadata provider @prv_pid. This permission check consists of
+ * several different parts:
+ * - Providers can grant metadata items unchecked. Regardless of their type,
+ * they're always granted to the requestor. This mask is passed as @prv_mask.
+ * - Basic items (credentials and connection metadata) are granted implicitly
+ * to everyone. They're publicly available to any bus-user that can see the
+ * provider.
+ * - Process credentials that are not granted implicitly follow the same
+ * permission checks as /proc. This means, we always assume a requestor
+ * process has access to their *own* /proc mount, if they have access to
+ * kdbusfs.
+ *
+ * Return: Mask of metadata that is granted.
+ */
+static u64 kdbus_meta_get_mask(struct pid *prv_pid, u64 prv_mask,
+ struct pid *req_pid,
+ const struct cred *req_cred, u64 req_mask)
+{
+ u64 missing, impl_mask, proc_mask = 0;
+
+ /*
+ * Connection metadata and basic unix process credentials are
+ * transmitted implicitly, and cannot be suppressed. Both are required
+ * to perform user-space policies on the receiver-side. Furthermore,
+ * connection metadata is public state, anyway, and unix credentials
+ * are needed for UDS-compatibility. We extend them slightly by
+ * auxiliary groups and additional uids/gids/pids.
+ */
+ impl_mask = /* connection metadata */
+ KDBUS_ATTACH_CONN_DESCRIPTION |
+ KDBUS_ATTACH_TIMESTAMP |
+ KDBUS_ATTACH_NAMES |
+ /* credentials and pids */
+ KDBUS_ATTACH_AUXGROUPS |
+ KDBUS_ATTACH_CREDS |
+ KDBUS_ATTACH_PIDS;
+
+ /*
+ * Calculate the set of metadata that is not granted implicitly nor by
+ * the sender, but still requested by the receiver. If any are left,
+ * perform rather expensive /proc access checks for them.
+ */
+ missing = req_mask & ~((prv_mask | impl_mask) & req_mask);
+ if (missing)
+ proc_mask = kdbus_meta_proc_mask(prv_pid, req_pid, req_cred,
+ missing);
+
+ return (prv_mask | impl_mask | proc_mask) & req_mask;
+}
+
+/**
+ */
+u64 kdbus_meta_info_mask(const struct kdbus_conn *conn, u64 mask)
+{
+ return kdbus_meta_get_mask(conn->pid,
+ atomic64_read(&conn->attach_flags_send),
+ task_pid(current),
+ current_cred(),
+ mask);
+}
+
+/**
+ */
+u64 kdbus_meta_msg_mask(const struct kdbus_conn *snd,
+ const struct kdbus_conn *rcv)
+{
+ return kdbus_meta_get_mask(task_pid(current),
+ atomic64_read(&snd->attach_flags_send),
+ rcv->pid,
+ rcv->cred,
+ atomic64_read(&rcv->attach_flags_recv));
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_METADATA_H
+#define __KDBUS_METADATA_H
+
+#include <linux/kernel.h>
+
+struct kdbus_conn;
+struct kdbus_pool_slice;
+
+struct kdbus_meta_proc;
+struct kdbus_meta_conn;
+
+/**
+ * struct kdbus_meta_fake - Fake metadata
+ * @valid: Bitmask of collected and valid items
+ * @uid: UID of process
+ * @euid: EUID of process
+ * @suid: SUID of process
+ * @fsuid: FSUID of process
+ * @gid: GID of process
+ * @egid: EGID of process
+ * @sgid: SGID of process
+ * @fsgid: FSGID of process
+ * @pid: PID of process
+ * @tgid: TGID of process
+ * @ppid: PPID of process
+ * @seclabel: Seclabel
+ */
+struct kdbus_meta_fake {
+ u64 valid;
+
+ /* KDBUS_ITEM_CREDS */
+ kuid_t uid, euid, suid, fsuid;
+ kgid_t gid, egid, sgid, fsgid;
+
+ /* KDBUS_ITEM_PIDS */
+ struct pid *pid, *tgid, *ppid;
+
+ /* KDBUS_ITEM_SECLABEL */
+ char *seclabel;
+};
+
+struct kdbus_meta_proc *kdbus_meta_proc_new(void);
+struct kdbus_meta_proc *kdbus_meta_proc_ref(struct kdbus_meta_proc *mp);
+struct kdbus_meta_proc *kdbus_meta_proc_unref(struct kdbus_meta_proc *mp);
+int kdbus_meta_proc_collect(struct kdbus_meta_proc *mp, u64 what);
+
+struct kdbus_meta_fake *kdbus_meta_fake_new(void);
+struct kdbus_meta_fake *kdbus_meta_fake_free(struct kdbus_meta_fake *mf);
+int kdbus_meta_fake_collect(struct kdbus_meta_fake *mf,
+ const struct kdbus_creds *creds,
+ const struct kdbus_pids *pids,
+ const char *seclabel);
+
+struct kdbus_meta_conn *kdbus_meta_conn_new(void);
+struct kdbus_meta_conn *kdbus_meta_conn_ref(struct kdbus_meta_conn *mc);
+struct kdbus_meta_conn *kdbus_meta_conn_unref(struct kdbus_meta_conn *mc);
+int kdbus_meta_conn_collect(struct kdbus_meta_conn *mc,
+ struct kdbus_conn *conn,
+ u64 msg_seqnum, u64 what);
+
+int kdbus_meta_emit(struct kdbus_meta_proc *mp,
+ struct kdbus_meta_fake *mf,
+ struct kdbus_meta_conn *mc,
+ struct kdbus_conn *conn,
+ u64 mask,
+ struct kdbus_item **out_items,
+ size_t *out_size);
+u64 kdbus_meta_info_mask(const struct kdbus_conn *conn, u64 mask);
+u64 kdbus_meta_msg_mask(const struct kdbus_conn *snd,
+ const struct kdbus_conn *rcv);
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/cred.h>
+#include <linux/ctype.h>
+#include <linux/fs.h>
+#include <linux/hash.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "endpoint.h"
+#include "handle.h"
+#include "item.h"
+#include "names.h"
+#include "notify.h"
+#include "policy.h"
+
+#define KDBUS_NAME_SAVED_MASK (KDBUS_NAME_ALLOW_REPLACEMENT | \
+ KDBUS_NAME_QUEUE)
+
+static bool kdbus_name_owner_is_used(struct kdbus_name_owner *owner)
+{
+ return !list_empty(&owner->name_entry) ||
+ owner == owner->name->activator;
+}
+
+static struct kdbus_name_owner *
+kdbus_name_owner_new(struct kdbus_conn *conn, struct kdbus_name_entry *name,
+ u64 flags)
+{
+ struct kdbus_name_owner *owner;
+
+ kdbus_conn_assert_active(conn);
+
+ if (conn->name_count >= KDBUS_CONN_MAX_NAMES)
+ return ERR_PTR(-E2BIG);
+
+ owner = kmalloc(sizeof(*owner), GFP_KERNEL);
+ if (!owner)
+ return ERR_PTR(-ENOMEM);
+
+ owner->flags = flags & KDBUS_NAME_SAVED_MASK;
+ owner->conn = conn;
+ owner->name = name;
+ list_add_tail(&owner->conn_entry, &conn->names_list);
+ INIT_LIST_HEAD(&owner->name_entry);
+
+ ++conn->name_count;
+ return owner;
+}
+
+static void kdbus_name_owner_free(struct kdbus_name_owner *owner)
+{
+ if (!owner)
+ return;
+
+ WARN_ON(kdbus_name_owner_is_used(owner));
+ --owner->conn->name_count;
+ list_del(&owner->conn_entry);
+ kfree(owner);
+}
+
+static struct kdbus_name_owner *
+kdbus_name_owner_find(struct kdbus_name_entry *name, struct kdbus_conn *conn)
+{
+ struct kdbus_name_owner *owner;
+
+ /*
+ * Use conn->names_list over name->queue to make sure boundaries of
+ * this linear search are controlled by the connection itself.
+ * Furthermore, this will find normal owners as well as activators
+ * without any additional code.
+ */
+ list_for_each_entry(owner, &conn->names_list, conn_entry)
+ if (owner->name == name)
+ return owner;
+
+ return NULL;
+}
+
+static bool kdbus_name_entry_is_used(struct kdbus_name_entry *name)
+{
+ return !list_empty(&name->queue) || name->activator;
+}
+
+static struct kdbus_name_owner *
+kdbus_name_entry_first(struct kdbus_name_entry *name)
+{
+ return list_first_entry_or_null(&name->queue, struct kdbus_name_owner,
+ name_entry);
+}
+
+static struct kdbus_name_entry *
+kdbus_name_entry_new(struct kdbus_name_registry *r, u32 hash,
+ const char *name_str)
+{
+ struct kdbus_name_entry *name;
+ size_t namelen;
+
+ lockdep_assert_held(&r->rwlock);
+
+ namelen = strlen(name_str);
+
+ name = kmalloc(sizeof(*name) + namelen + 1, GFP_KERNEL);
+ if (!name)
+ return ERR_PTR(-ENOMEM);
+
+ name->name_id = ++r->name_seq_last;
+ name->activator = NULL;
+ INIT_LIST_HEAD(&name->queue);
+ hash_add(r->entries_hash, &name->hentry, hash);
+ memcpy(name->name, name_str, namelen + 1);
+
+ return name;
+}
+
+static void kdbus_name_entry_free(struct kdbus_name_entry *name)
+{
+ if (!name)
+ return;
+
+ WARN_ON(kdbus_name_entry_is_used(name));
+ hash_del(&name->hentry);
+ kfree(name);
+}
+
+static struct kdbus_name_entry *
+kdbus_name_entry_find(struct kdbus_name_registry *r, u32 hash,
+ const char *name_str)
+{
+ struct kdbus_name_entry *name;
+
+ lockdep_assert_held(&r->rwlock);
+
+ hash_for_each_possible(r->entries_hash, name, hentry, hash)
+ if (!strcmp(name->name, name_str))
+ return name;
+
+ return NULL;
+}
+
+/**
+ * kdbus_name_registry_new() - create a new name registry
+ *
+ * Return: a new kdbus_name_registry on success, ERR_PTR on failure.
+ */
+struct kdbus_name_registry *kdbus_name_registry_new(void)
+{
+ struct kdbus_name_registry *r;
+
+ r = kmalloc(sizeof(*r), GFP_KERNEL);
+ if (!r)
+ return ERR_PTR(-ENOMEM);
+
+ hash_init(r->entries_hash);
+ init_rwsem(&r->rwlock);
+ r->name_seq_last = 0;
+
+ return r;
+}
+
+/**
+ * kdbus_name_registry_free() - free name registry
+ * @r: name registry to free, or NULL
+ *
+ * Free a name registry and cleanup all internal objects. This is a no-op if
+ * you pass NULL as registry.
+ */
+void kdbus_name_registry_free(struct kdbus_name_registry *r)
+{
+ if (!r)
+ return;
+
+ WARN_ON(!hash_empty(r->entries_hash));
+ kfree(r);
+}
+
+/**
+ * kdbus_name_lookup_unlocked() - lookup name in registry
+ * @reg: name registry
+ * @name: name to lookup
+ *
+ * This looks up @name in the given name-registry and returns the
+ * kdbus_name_entry object. The caller must hold the registry-lock and must not
+ * access the returned object after releasing the lock.
+ *
+ * Return: Pointer to name-entry, or NULL if not found.
+ */
+struct kdbus_name_entry *
+kdbus_name_lookup_unlocked(struct kdbus_name_registry *reg, const char *name)
+{
+ return kdbus_name_entry_find(reg, kdbus_strhash(name), name);
+}
+
+static int kdbus_name_become_activator(struct kdbus_name_owner *owner,
+ u64 *return_flags)
+{
+ if (kdbus_name_owner_is_used(owner))
+ return -EALREADY;
+ if (owner->name->activator)
+ return -EEXIST;
+
+ owner->name->activator = owner;
+ owner->flags |= KDBUS_NAME_ACTIVATOR;
+
+ if (kdbus_name_entry_first(owner->name)) {
+ owner->flags |= KDBUS_NAME_IN_QUEUE;
+ } else {
+ owner->flags |= KDBUS_NAME_PRIMARY;
+ kdbus_notify_name_change(owner->conn->ep->bus,
+ KDBUS_ITEM_NAME_ADD,
+ 0, owner->conn->id,
+ 0, owner->flags,
+ owner->name->name);
+ }
+
+ if (return_flags)
+ *return_flags = owner->flags | KDBUS_NAME_ACQUIRED;
+
+ return 0;
+}
+
+static int kdbus_name_update(struct kdbus_name_owner *owner, u64 flags,
+ u64 *return_flags)
+{
+ struct kdbus_name_owner *primary, *activator;
+ struct kdbus_name_entry *name;
+ struct kdbus_bus *bus;
+ u64 nflags = 0;
+ int ret = 0;
+
+ name = owner->name;
+ bus = owner->conn->ep->bus;
+ primary = kdbus_name_entry_first(name);
+ activator = name->activator;
+
+ /* cannot be activator and acquire a name */
+ if (owner == activator)
+ return -EUCLEAN;
+
+ /* update saved flags */
+ owner->flags = flags & KDBUS_NAME_SAVED_MASK;
+
+ if (!primary) {
+ /*
+ * No primary owner (but maybe an activator). Take over the
+ * name.
+ */
+
+ list_add(&owner->name_entry, &name->queue);
+ owner->flags |= KDBUS_NAME_PRIMARY;
+ nflags |= KDBUS_NAME_ACQUIRED;
+
+ /* move messages to new owner on activation */
+ if (activator) {
+ kdbus_conn_move_messages(owner->conn, activator->conn,
+ name->name_id);
+ kdbus_notify_name_change(bus, KDBUS_ITEM_NAME_CHANGE,
+ activator->conn->id, owner->conn->id,
+ activator->flags, owner->flags,
+ name->name);
+ activator->flags &= ~KDBUS_NAME_PRIMARY;
+ activator->flags |= KDBUS_NAME_IN_QUEUE;
+ } else {
+ kdbus_notify_name_change(bus, KDBUS_ITEM_NAME_ADD,
+ 0, owner->conn->id,
+ 0, owner->flags,
+ name->name);
+ }
+
+ } else if (owner == primary) {
+ /*
+ * Already the primary owner of the name, flags were already
+ * updated. Nothing to do.
+ */
+
+ owner->flags |= KDBUS_NAME_PRIMARY;
+
+ } else if ((primary->flags & KDBUS_NAME_ALLOW_REPLACEMENT) &&
+ (flags & KDBUS_NAME_REPLACE_EXISTING)) {
+ /*
+ * We're not the primary owner but can replace it. Move us
+ * ahead of the primary owner and acquire the name (possibly
+ * skipping queued owners ahead of us).
+ */
+
+ list_del_init(&owner->name_entry);
+ list_add(&owner->name_entry, &name->queue);
+ owner->flags |= KDBUS_NAME_PRIMARY;
+ nflags |= KDBUS_NAME_ACQUIRED;
+
+ kdbus_notify_name_change(bus, KDBUS_ITEM_NAME_CHANGE,
+ primary->conn->id, owner->conn->id,
+ primary->flags, owner->flags,
+ name->name);
+
+ /* requeue old primary, or drop if queueing not wanted */
+ if (primary->flags & KDBUS_NAME_QUEUE) {
+ primary->flags &= ~KDBUS_NAME_PRIMARY;
+ primary->flags |= KDBUS_NAME_IN_QUEUE;
+ } else {
+ list_del_init(&primary->name_entry);
+ kdbus_name_owner_free(primary);
+ }
+
+ } else if (flags & KDBUS_NAME_QUEUE) {
+ /*
+ * Name is already occupied and we cannot take it over, but
+ * queuing is allowed. Put us silently on the queue, if not
+ * already there.
+ */
+
+ owner->flags |= KDBUS_NAME_IN_QUEUE;
+ if (!kdbus_name_owner_is_used(owner)) {
+ list_add_tail(&owner->name_entry, &name->queue);
+ nflags |= KDBUS_NAME_ACQUIRED;
+ }
+ } else if (kdbus_name_owner_is_used(owner)) {
+ /*
+ * Already queued on name, but re-queueing was not requested.
+ * Make sure to unlink it from the name, the caller is
+ * responsible for releasing it.
+ */
+
+ list_del_init(&owner->name_entry);
+ } else {
+ /*
+ * Name is already claimed and queueing is not requested.
+ * Return error to the caller.
+ */
+
+ ret = -EEXIST;
+ }
+
+ if (return_flags)
+ *return_flags = owner->flags | nflags;
+
+ return ret;
+}
+
+int kdbus_name_acquire(struct kdbus_name_registry *reg,
+ struct kdbus_conn *conn, const char *name_str,
+ u64 flags, u64 *return_flags)
+{
+ struct kdbus_name_entry *name = NULL;
+ struct kdbus_name_owner *owner = NULL;
+ u32 hash;
+ int ret;
+
+ kdbus_conn_assert_active(conn);
+
+ down_write(®->rwlock);
+
+ /*
+ * Verify the connection has access to the name. Do this before testing
+ * for double-acquisitions and other errors to make sure we do not leak
+ * information about this name through possible custom endpoints.
+ */
+ if (!kdbus_conn_policy_own_name(conn, current_cred(), name_str)) {
+ ret = -EPERM;
+ goto exit;
+ }
+
+ /*
+ * Lookup the name entry. If it already exists, search for an owner
+ * entry as we might already own that name. If either does not exist,
+ * we will allocate a fresh one.
+ */
+ hash = kdbus_strhash(name_str);
+ name = kdbus_name_entry_find(reg, hash, name_str);
+ if (name) {
+ owner = kdbus_name_owner_find(name, conn);
+ } else {
+ name = kdbus_name_entry_new(reg, hash, name_str);
+ if (IS_ERR(name)) {
+ ret = PTR_ERR(name);
+ name = NULL;
+ goto exit;
+ }
+ }
+
+ /* create name owner object if not already queued */
+ if (!owner) {
+ owner = kdbus_name_owner_new(conn, name, flags);
+ if (IS_ERR(owner)) {
+ ret = PTR_ERR(owner);
+ owner = NULL;
+ goto exit;
+ }
+ }
+
+ if (flags & KDBUS_NAME_ACTIVATOR)
+ ret = kdbus_name_become_activator(owner, return_flags);
+ else
+ ret = kdbus_name_update(owner, flags, return_flags);
+ if (ret < 0)
+ goto exit;
+
+exit:
+ if (owner && !kdbus_name_owner_is_used(owner))
+ kdbus_name_owner_free(owner);
+ if (name && !kdbus_name_entry_is_used(name))
+ kdbus_name_entry_free(name);
+ up_write(®->rwlock);
+ kdbus_notify_flush(conn->ep->bus);
+ return ret;
+}
+
+static void kdbus_name_release_unlocked(struct kdbus_name_owner *owner)
+{
+ struct kdbus_name_owner *primary, *next;
+ struct kdbus_name_entry *name;
+
+ name = owner->name;
+ primary = kdbus_name_entry_first(name);
+
+ list_del_init(&owner->name_entry);
+ if (owner == name->activator)
+ name->activator = NULL;
+
+ if (!primary || owner == primary) {
+ next = kdbus_name_entry_first(name);
+ if (!next)
+ next = name->activator;
+
+ if (next) {
+ /* hand to next in queue */
+ next->flags &= ~KDBUS_NAME_IN_QUEUE;
+ next->flags |= KDBUS_NAME_PRIMARY;
+ if (next == name->activator)
+ kdbus_conn_move_messages(next->conn,
+ owner->conn,
+ name->name_id);
+
+ kdbus_notify_name_change(owner->conn->ep->bus,
+ KDBUS_ITEM_NAME_CHANGE,
+ owner->conn->id, next->conn->id,
+ owner->flags, next->flags,
+ name->name);
+ } else {
+ kdbus_notify_name_change(owner->conn->ep->bus,
+ KDBUS_ITEM_NAME_REMOVE,
+ owner->conn->id, 0,
+ owner->flags, 0,
+ name->name);
+ }
+ }
+
+ kdbus_name_owner_free(owner);
+ if (!kdbus_name_entry_is_used(name))
+ kdbus_name_entry_free(name);
+}
+
+static int kdbus_name_release(struct kdbus_name_registry *reg,
+ struct kdbus_conn *conn,
+ const char *name_str)
+{
+ struct kdbus_name_owner *owner;
+ struct kdbus_name_entry *name;
+ int ret = 0;
+
+ down_write(®->rwlock);
+ name = kdbus_name_entry_find(reg, kdbus_strhash(name_str), name_str);
+ if (name) {
+ owner = kdbus_name_owner_find(name, conn);
+ if (owner)
+ kdbus_name_release_unlocked(owner);
+ else
+ ret = -EADDRINUSE;
+ } else {
+ ret = -ESRCH;
+ }
+ up_write(®->rwlock);
+
+ kdbus_notify_flush(conn->ep->bus);
+ return ret;
+}
+
+/**
+ * kdbus_name_release_all() - remove all name entries of a given connection
+ * @reg: name registry
+ * @conn: connection
+ */
+void kdbus_name_release_all(struct kdbus_name_registry *reg,
+ struct kdbus_conn *conn)
+{
+ struct kdbus_name_owner *owner;
+
+ down_write(®->rwlock);
+
+ while ((owner = list_first_entry_or_null(&conn->names_list,
+ struct kdbus_name_owner,
+ conn_entry)))
+ kdbus_name_release_unlocked(owner);
+
+ up_write(®->rwlock);
+
+ kdbus_notify_flush(conn->ep->bus);
+}
+
+/**
+ * kdbus_name_is_valid() - check if a name is valid
+ * @p: The name to check
+ * @allow_wildcard: Whether or not to allow a wildcard name
+ *
+ * A name is valid if all of the following criterias are met:
+ *
+ * - The name has two or more elements separated by a period ('.') character.
+ * - All elements must contain at least one character.
+ * - Each element must only contain the ASCII characters "[A-Z][a-z][0-9]_-"
+ * and must not begin with a digit.
+ * - The name must not exceed KDBUS_NAME_MAX_LEN.
+ * - If @allow_wildcard is true, the name may end on '.*'
+ */
+bool kdbus_name_is_valid(const char *p, bool allow_wildcard)
+{
+ bool dot, found_dot = false;
+ const char *q;
+
+ for (dot = true, q = p; *q; q++) {
+ if (*q == '.') {
+ if (dot)
+ return false;
+
+ found_dot = true;
+ dot = true;
+ } else {
+ bool good;
+
+ good = isalpha(*q) || (!dot && isdigit(*q)) ||
+ *q == '_' || *q == '-' ||
+ (allow_wildcard && dot &&
+ *q == '*' && *(q + 1) == '\0');
+
+ if (!good)
+ return false;
+
+ dot = false;
+ }
+ }
+
+ if (q - p > KDBUS_NAME_MAX_LEN)
+ return false;
+
+ if (dot)
+ return false;
+
+ if (!found_dot)
+ return false;
+
+ return true;
+}
+
+/**
+ * kdbus_cmd_name_acquire() - handle KDBUS_CMD_NAME_ACQUIRE
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_name_acquire(struct kdbus_conn *conn, void __user *argp)
+{
+ const char *item_name;
+ struct kdbus_cmd *cmd;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_NAME, .mandatory = true },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_NAME_REPLACE_EXISTING |
+ KDBUS_NAME_ALLOW_REPLACEMENT |
+ KDBUS_NAME_QUEUE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ if (!kdbus_conn_is_ordinary(conn))
+ return -EOPNOTSUPP;
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ item_name = argv[1].item->str;
+ if (!kdbus_name_is_valid(item_name, false)) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ ret = kdbus_name_acquire(conn->ep->bus->name_registry, conn, item_name,
+ cmd->flags, &cmd->return_flags);
+
+exit:
+ return kdbus_args_clear(&args, ret);
+}
+
+/**
+ * kdbus_cmd_name_release() - handle KDBUS_CMD_NAME_RELEASE
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_name_release(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_cmd *cmd;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_NAME, .mandatory = true },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ if (!kdbus_conn_is_ordinary(conn))
+ return -EOPNOTSUPP;
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ ret = kdbus_name_release(conn->ep->bus->name_registry, conn,
+ argv[1].item->str);
+ return kdbus_args_clear(&args, ret);
+}
+
+static int kdbus_list_write(struct kdbus_conn *conn,
+ struct kdbus_conn *c,
+ struct kdbus_pool_slice *slice,
+ size_t *pos,
+ struct kdbus_name_owner *o,
+ bool write)
+{
+ struct kvec kvec[4];
+ size_t cnt = 0;
+ int ret;
+
+ /* info header */
+ struct kdbus_info info = {
+ .size = 0,
+ .id = c->id,
+ .flags = c->flags,
+ };
+
+ /* fake the header of a kdbus_name item */
+ struct {
+ u64 size;
+ u64 type;
+ u64 flags;
+ } h = {};
+
+ if (o && !kdbus_conn_policy_see_name_unlocked(conn, current_cred(),
+ o->name->name))
+ return 0;
+
+ kdbus_kvec_set(&kvec[cnt++], &info, sizeof(info), &info.size);
+
+ /* append name */
+ if (o) {
+ size_t slen = strlen(o->name->name) + 1;
+
+ h.size = offsetof(struct kdbus_item, name.name) + slen;
+ h.type = KDBUS_ITEM_OWNED_NAME;
+ h.flags = o->flags;
+
+ kdbus_kvec_set(&kvec[cnt++], &h, sizeof(h), &info.size);
+ kdbus_kvec_set(&kvec[cnt++], o->name->name, slen, &info.size);
+ cnt += !!kdbus_kvec_pad(&kvec[cnt], &info.size);
+ }
+
+ if (write) {
+ ret = kdbus_pool_slice_copy_kvec(slice, *pos, kvec,
+ cnt, info.size);
+ if (ret < 0)
+ return ret;
+ }
+
+ *pos += info.size;
+ return 0;
+}
+
+static int kdbus_list_all(struct kdbus_conn *conn, u64 flags,
+ struct kdbus_pool_slice *slice,
+ size_t *pos, bool write)
+{
+ struct kdbus_conn *c;
+ size_t p = *pos;
+ int ret, i;
+
+ hash_for_each(conn->ep->bus->conn_hash, i, c, hentry) {
+ bool added = false;
+
+ /* skip monitors */
+ if (kdbus_conn_is_monitor(c))
+ continue;
+
+ /* all names the connection owns */
+ if (flags & (KDBUS_LIST_NAMES |
+ KDBUS_LIST_ACTIVATORS |
+ KDBUS_LIST_QUEUED)) {
+ struct kdbus_name_owner *o;
+
+ list_for_each_entry(o, &c->names_list, conn_entry) {
+ if (o->flags & KDBUS_NAME_ACTIVATOR) {
+ if (!(flags & KDBUS_LIST_ACTIVATORS))
+ continue;
+
+ ret = kdbus_list_write(conn, c, slice,
+ &p, o, write);
+ if (ret < 0) {
+ mutex_unlock(&c->lock);
+ return ret;
+ }
+
+ added = true;
+ } else if (o->flags & KDBUS_NAME_IN_QUEUE) {
+ if (!(flags & KDBUS_LIST_QUEUED))
+ continue;
+
+ ret = kdbus_list_write(conn, c, slice,
+ &p, o, write);
+ if (ret < 0) {
+ mutex_unlock(&c->lock);
+ return ret;
+ }
+
+ added = true;
+ } else if (flags & KDBUS_LIST_NAMES) {
+ ret = kdbus_list_write(conn, c, slice,
+ &p, o, write);
+ if (ret < 0) {
+ mutex_unlock(&c->lock);
+ return ret;
+ }
+
+ added = true;
+ }
+ }
+ }
+
+ /* nothing added so far, just add the unique ID */
+ if (!added && (flags & KDBUS_LIST_UNIQUE)) {
+ ret = kdbus_list_write(conn, c, slice, &p, NULL, write);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ *pos = p;
+ return 0;
+}
+
+/**
+ * kdbus_cmd_list() - handle KDBUS_CMD_LIST
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: >=0 on success, negative error code on failure.
+ */
+int kdbus_cmd_list(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_name_registry *reg = conn->ep->bus->name_registry;
+ struct kdbus_pool_slice *slice = NULL;
+ struct kdbus_cmd_list *cmd;
+ size_t pos, size;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_LIST_UNIQUE |
+ KDBUS_LIST_NAMES |
+ KDBUS_LIST_ACTIVATORS |
+ KDBUS_LIST_QUEUED,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ /* lock order: domain -> bus -> ep -> names -> conn */
+ down_read(®->rwlock);
+ down_read(&conn->ep->bus->conn_rwlock);
+ down_read(&conn->ep->policy_db.entries_rwlock);
+
+ /* size of records */
+ size = 0;
+ ret = kdbus_list_all(conn, cmd->flags, NULL, &size, false);
+ if (ret < 0)
+ goto exit_unlock;
+
+ if (size == 0) {
+ kdbus_pool_publish_empty(conn->pool, &cmd->offset,
+ &cmd->list_size);
+ } else {
+ slice = kdbus_pool_slice_alloc(conn->pool, size, false);
+ if (IS_ERR(slice)) {
+ ret = PTR_ERR(slice);
+ slice = NULL;
+ goto exit_unlock;
+ }
+
+ /* copy the records */
+ pos = 0;
+ ret = kdbus_list_all(conn, cmd->flags, slice, &pos, true);
+ if (ret < 0)
+ goto exit_unlock;
+
+ WARN_ON(pos != size);
+ kdbus_pool_slice_publish(slice, &cmd->offset, &cmd->list_size);
+ }
+
+ if (kdbus_member_set_user(&cmd->offset, argp, typeof(*cmd), offset) ||
+ kdbus_member_set_user(&cmd->list_size, argp,
+ typeof(*cmd), list_size))
+ ret = -EFAULT;
+
+exit_unlock:
+ up_read(&conn->ep->policy_db.entries_rwlock);
+ up_read(&conn->ep->bus->conn_rwlock);
+ up_read(®->rwlock);
+ kdbus_pool_slice_release(slice);
+ return kdbus_args_clear(&args, ret);
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_NAMES_H
+#define __KDBUS_NAMES_H
+
+#include <linux/hashtable.h>
+#include <linux/rwsem.h>
+
+struct kdbus_name_entry;
+struct kdbus_name_owner;
+struct kdbus_name_registry;
+
+/**
+ * struct kdbus_name_registry - names registered for a bus
+ * @entries_hash: Map of entries
+ * @lock: Registry data lock
+ * @name_seq_last: Last used sequence number to assign to a name entry
+ */
+struct kdbus_name_registry {
+ DECLARE_HASHTABLE(entries_hash, 8);
+ struct rw_semaphore rwlock;
+ u64 name_seq_last;
+};
+
+/**
+ * struct kdbus_name_entry - well-know name entry
+ * @name_id: sequence number of name entry to be able to uniquely
+ * identify a name over its registration lifetime
+ * @activator: activator of this name, or NULL
+ * @queue: list of queued owners
+ * @hentry: entry in registry map
+ * @name: well-known name
+ */
+struct kdbus_name_entry {
+ u64 name_id;
+ struct kdbus_name_owner *activator;
+ struct list_head queue;
+ struct hlist_node hentry;
+ char name[];
+};
+
+/**
+ * struct kdbus_name_owner - owner of a well-known name
+ * @flags: KDBUS_NAME_* flags of this owner
+ * @conn: connection owning the name
+ * @name: name that is owned
+ * @conn_entry: link into @conn
+ * @name_entry: link into @name
+ */
+struct kdbus_name_owner {
+ u64 flags;
+ struct kdbus_conn *conn;
+ struct kdbus_name_entry *name;
+ struct list_head conn_entry;
+ struct list_head name_entry;
+};
+
+bool kdbus_name_is_valid(const char *p, bool allow_wildcard);
+
+struct kdbus_name_registry *kdbus_name_registry_new(void);
+void kdbus_name_registry_free(struct kdbus_name_registry *reg);
+
+struct kdbus_name_entry *
+kdbus_name_lookup_unlocked(struct kdbus_name_registry *reg, const char *name);
+
+int kdbus_name_acquire(struct kdbus_name_registry *reg,
+ struct kdbus_conn *conn, const char *name,
+ u64 flags, u64 *return_flags);
+void kdbus_name_release_all(struct kdbus_name_registry *reg,
+ struct kdbus_conn *conn);
+
+int kdbus_cmd_name_acquire(struct kdbus_conn *conn, void __user *argp);
+int kdbus_cmd_name_release(struct kdbus_conn *conn, void __user *argp);
+int kdbus_cmd_list(struct kdbus_conn *conn, void __user *argp);
+
+/**
+ * kdbus_name_get_owner() - get current owner of a name
+ * @name: name to get current owner of
+ *
+ * This returns a pointer to the current owner of a name (or its activator if
+ * there is no owner). The caller must make sure @name is valid and does not
+ * vanish.
+ *
+ * Return: Pointer to current owner or NULL if there is none.
+ */
+static inline struct kdbus_name_owner *
+kdbus_name_get_owner(struct kdbus_name_entry *name)
+{
+ return list_first_entry_or_null(&name->queue, struct kdbus_name_owner,
+ name_entry) ? : name->activator;
+}
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/atomic.h>
+#include <linux/fs.h>
+#include <linux/idr.h>
+#include <linux/kdev_t.h>
+#include <linux/rbtree.h>
+#include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+
+#include "bus.h"
+#include "domain.h"
+#include "endpoint.h"
+#include "fs.h"
+#include "handle.h"
+#include "node.h"
+#include "util.h"
+
+/**
+ * DOC: kdbus nodes
+ *
+ * Nodes unify lifetime management across exposed kdbus objects and provide a
+ * hierarchy. Each kdbus object, that might be exposed to user-space, has a
+ * kdbus_node object embedded and is linked into the hierarchy. Each node can
+ * have any number (0-n) of child nodes linked. Each child retains a reference
+ * to its parent node. For root-nodes, the parent is NULL.
+ *
+ * Each node object goes through a bunch of states during it's lifetime:
+ * * NEW
+ * * LINKED (can be skipped by NEW->FREED transition)
+ * * ACTIVE (can be skipped by LINKED->INACTIVE transition)
+ * * INACTIVE
+ * * DRAINED
+ * * FREED
+ *
+ * Each node is allocated by the caller and initialized via kdbus_node_init().
+ * This never fails and sets the object into state NEW. From now on, ref-counts
+ * on the node manage its lifetime. During init, the ref-count is set to 1. Once
+ * it drops to 0, the node goes to state FREED and the node->free_cb() callback
+ * is called to deallocate any memory.
+ *
+ * After initializing a node, you usually link it into the hierarchy. You need
+ * to provide a parent node and a name. The node will be linked as child to the
+ * parent and a globally unique ID is assigned to the child. The name of the
+ * child must be unique for all children of this parent. Otherwise, linking the
+ * child will fail with -EEXIST.
+ * Note that the child is not marked active, yet. Admittedly, it prevents any
+ * other node from being linked with the same name (thus, it reserves that
+ * name), but any child-lookup (via name or unique ID) will never return this
+ * child unless it has been marked active.
+ *
+ * Once successfully linked, you can use kdbus_node_activate() to activate a
+ * child. This will mark the child active. This state can be skipped by directly
+ * deactivating the child via kdbus_node_deactivate() (see below).
+ * By activating a child, you enable any lookups on this child to succeed from
+ * now on. Furthermore, any code that got its hands on a reference to the node,
+ * can from now on "acquire" the node.
+ *
+ * Active References (or: 'acquiring' and 'releasing' a node)
+ * Additionally to normal object references, nodes support something we call
+ * "active references". An active reference can be acquired via
+ * kdbus_node_acquire() and released via kdbus_node_release(). A caller
+ * _must_ own a normal object reference whenever calling those functions.
+ * Unlike object references, acquiring an active reference can fail (by
+ * returning 'false' from kdbus_node_acquire()). An active reference can
+ * only be acquired if the node is marked active. If it is not marked
+ * active, yet, or if it was already deactivated, no more active references
+ * can be acquired, ever!
+ * Active references are used to track tasks working on a node. Whenever a
+ * task enters kernel-space to perform an action on a node, it acquires an
+ * active reference, performs the action and releases the reference again.
+ * While holding an active reference, the node is guaranteed to stay active.
+ * If the node is deactivated in parallel, the node is marked as
+ * deactivated, then we wait for all active references to be dropped, before
+ * we finally proceed with any cleanups. That is, if you hold an active
+ * reference to a node, any resources that are bound to the "active" state
+ * are guaranteed to stay accessible until you release your reference.
+ *
+ * Active-references are very similar to rw-locks, where acquiring a node is
+ * equal to try-read-lock and releasing to read-unlock. Deactivating a node
+ * means write-lock and never releasing it again.
+ * Unlike rw-locks, the 'active reference' concept is more versatile and
+ * avoids unusual rw-lock usage (never releasing a write-lock..).
+ *
+ * It is safe to acquire multiple active-references recursively. But you
+ * need to check the return value of kdbus_node_acquire() on _each_ call. It
+ * may stop granting references at _any_ time.
+ *
+ * You're free to perform any operations you want while holding an active
+ * reference, except sleeping for an indefinite period. Sleeping for a fixed
+ * amount of time is fine, but you usually should not wait on wait-queues
+ * without a timeout.
+ * For example, if you wait for I/O to happen, you should gather all data
+ * and schedule the I/O operation, then release your active reference and
+ * wait for it to complete. Then try to acquire a new reference. If it
+ * fails, perform any cleanup (the node is now dead). Otherwise, you can
+ * finish your operation.
+ *
+ * All nodes can be deactivated via kdbus_node_deactivate() at any time. You can
+ * call this multiple times, even in parallel or on nodes that were never
+ * linked, and it will just work. The only restriction is, you must not hold an
+ * active reference when calling kdbus_node_deactivate().
+ * By deactivating a node, it is immediately marked inactive. Then, we wait for
+ * all active references to be released (called 'draining' the node). This
+ * shouldn't take very long as we don't perform long-lasting operations while
+ * holding an active reference. Note that once the node is marked inactive, no
+ * new active references can be acquired.
+ * Once all active references are dropped, the node is considered 'drained'. Now
+ * kdbus_node_deactivate() is called on each child of the node before we
+ * continue deactivating our node. That is, once all children are entirely
+ * deactivated, we call ->release_cb() of our node. ->release_cb() can release
+ * any resources on that node which are bound to the "active" state of a node.
+ * When done, we unlink the node from its parent rb-tree, mark it as
+ * 'released' and return.
+ * If kdbus_node_deactivate() is called multiple times (even in parallel), all
+ * but one caller will just wait until the node is fully deactivated. That is,
+ * one random caller of kdbus_node_deactivate() is selected to call
+ * ->release_cb() and cleanup the node. Only once all this is done, all other
+ * callers will return from kdbus_node_deactivate(). That is, it doesn't matter
+ * whether you're the selected caller or not, it will only return after
+ * everything is fully done.
+ *
+ * When a node is activated, we acquire a normal object reference to the node.
+ * This reference is dropped after deactivation is fully done (and only iff the
+ * node really was activated). This allows callers to link+activate a child node
+ * and then drop all refs. The node will be deactivated together with the
+ * parent, and then be freed when this reference is dropped.
+ *
+ * Currently, nodes provide a bunch of resources that external code can use
+ * directly. This includes:
+ *
+ * * node->waitq: Each node has its own wait-queue that is used to manage
+ * the 'active' state. When a node is deactivated, we wait on
+ * this queue until all active refs are dropped. Analogously,
+ * when you release an active reference on a deactivated
+ * node, and the active ref-count drops to 0, we wake up a
+ * single thread on this queue. Furthermore, once the
+ * ->release_cb() callback finished, we wake up all waiters.
+ * The node-owner is free to re-use this wait-queue for other
+ * purposes. As node-management uses this queue only during
+ * deactivation, it is usually totally fine to re-use the
+ * queue for other, preferably low-overhead, use-cases.
+ *
+ * * node->type: This field defines the type of the owner of this node. It
+ * must be set during node initialization and must remain
+ * constant. The node management never looks at this value,
+ * but external users might use to gain access to the owner
+ * object of a node.
+ * It is totally up to the owner of the node to define what
+ * their type means. Usually it means you can access the
+ * parent structure via container_of(), as long as you hold an
+ * active reference to the node.
+ *
+ * * node->free_cb: callback after all references are dropped
+ * node->release_cb: callback during node deactivation
+ * These fields must be set by the node owner during
+ * node initialization. They must remain constant. If
+ * NULL, they're skipped.
+ *
+ * * node->mode: filesystem access modes
+ * node->uid: filesystem owner uid
+ * node->gid: filesystem owner gid
+ * These fields must be set by the node owner during node
+ * initialization. They must remain constant and may be
+ * accessed by other callers to properly initialize
+ * filesystem nodes.
+ *
+ * * node->id: This is an unsigned 32bit integer allocated by an IDA. It is
+ * always kept as small as possible during allocation and is
+ * globally unique across all nodes allocated by this module. 0
+ * is reserved as "not assigned" and is the default.
+ * The ID is assigned during kdbus_node_link() and is kept until
+ * the object is freed. Thus, the ID surpasses the active
+ * lifetime of a node. As long as you hold an object reference
+ * to a node (and the node was linked once), the ID is valid and
+ * unique.
+ *
+ * * node->name: name of this node
+ * node->hash: 31bit hash-value of @name (range [2..INT_MAX-1])
+ * These values follow the same lifetime rules as node->id.
+ * They're initialized when the node is linked and then remain
+ * constant until the last object reference is dropped.
+ * Unlike the id, the name is only unique across all siblings
+ * and only until the node is deactivated. Currently, the name
+ * is even unique if linked but not activated, yet. This might
+ * change in the future, though. Code should not rely on this.
+ *
+ * * node->lock: lock to protect node->children, node->rb, node->parent
+ * * node->parent: Reference to parent node. This is set during LINK time
+ * and is dropped during destruction. You must not access
+ * it unless you hold an active reference to the node or if
+ * you know the node is dead.
+ * * node->children: rb-tree of all linked children of this node. You must
+ * not access this directly, but use one of the iterator
+ * or lookup helpers.
+ */
+
+/*
+ * Bias values track states of "active references". They're all negative. If a
+ * node is active, its active-ref-counter is >=0 and tracks all active
+ * references. Once a node is deactivaed, we subtract NODE_BIAS. This means, the
+ * counter is now negative but still counts the active references. Once it drops
+ * to exactly NODE_BIAS, we know all active references were dropped. Exactly one
+ * thread will change it to NODE_RELEASE now, perform cleanup and then put it
+ * into NODE_DRAINED. Once drained, all other threads that tried deactivating
+ * the node will now be woken up (thus, they wait until the node is fully done).
+ * The initial state during node-setup is NODE_NEW. If a node is directly
+ * deactivated without having ever been active, it is put into
+ * NODE_RELEASE_DIRECT instead of NODE_BIAS. This tracks this one-bit state
+ * across node-deactivation. The task putting it into NODE_RELEASE now knows
+ * whether the node was active before or not.
+ *
+ * Some archs implement atomic_sub(v) with atomic_add(-v), so reserve INT_MIN
+ * to avoid overflows if multiplied by -1.
+ */
+#define KDBUS_NODE_BIAS (INT_MIN + 5)
+#define KDBUS_NODE_RELEASE_DIRECT (KDBUS_NODE_BIAS - 1)
+#define KDBUS_NODE_RELEASE (KDBUS_NODE_BIAS - 2)
+#define KDBUS_NODE_DRAINED (KDBUS_NODE_BIAS - 3)
+#define KDBUS_NODE_NEW (KDBUS_NODE_BIAS - 4)
+
+/* global unique ID mapping for kdbus nodes */
+DEFINE_IDA(kdbus_node_ida);
+
+/**
+ * kdbus_node_name_hash() - hash a name
+ * @name: The string to hash
+ *
+ * This computes the hash of @name. It is guaranteed to be in the range
+ * [2..INT_MAX-1]. The values 1, 2 and INT_MAX are unused as they are reserved
+ * for the filesystem code.
+ *
+ * Return: hash value of the passed string
+ */
+static unsigned int kdbus_node_name_hash(const char *name)
+{
+ unsigned int hash;
+
+ /* reserve hash numbers 0, 1 and >=INT_MAX for magic directories */
+ hash = kdbus_strhash(name) & INT_MAX;
+ if (hash < 2)
+ hash += 2;
+ if (hash >= INT_MAX)
+ hash = INT_MAX - 1;
+
+ return hash;
+}
+
+/**
+ * kdbus_node_name_compare() - compare a name with a node's name
+ * @hash: hash of the string to compare the node with
+ * @name: name to compare the node with
+ * @node: node to compare the name with
+ *
+ * Return: 0 if @name and @hash exactly match the information in @node, or
+ * an integer less than or greater than zero if @name is found, respectively,
+ * to be less than or be greater than the string stored in @node.
+ */
+static int kdbus_node_name_compare(unsigned int hash, const char *name,
+ const struct kdbus_node *node)
+{
+ if (hash != node->hash)
+ return hash - node->hash;
+
+ return strcmp(name, node->name);
+}
+
+/**
+ * kdbus_node_init() - initialize a kdbus_node
+ * @node: Pointer to the node to initialize
+ * @type: The type the node will have (KDBUS_NODE_*)
+ *
+ * The caller is responsible of allocating @node and initializating it to zero.
+ * Once this call returns, you must use the node_ref() and node_unref()
+ * functions to manage this node.
+ */
+void kdbus_node_init(struct kdbus_node *node, unsigned int type)
+{
+ atomic_set(&node->refcnt, 1);
+ mutex_init(&node->lock);
+ node->id = 0;
+ node->type = type;
+ RB_CLEAR_NODE(&node->rb);
+ node->children = RB_ROOT;
+ init_waitqueue_head(&node->waitq);
+ atomic_set(&node->active, KDBUS_NODE_NEW);
+}
+
+/**
+ * kdbus_node_link() - link a node into the nodes system
+ * @node: Pointer to the node to initialize
+ * @parent: Pointer to a parent node, may be %NULL
+ * @name: The name of the node (or NULL if root node)
+ *
+ * This links a node into the hierarchy. This must not be called multiple times.
+ * If @parent is NULL, the node becomes a new root node.
+ *
+ * This call will fail if @name is not unique across all its siblings or if no
+ * ID could be allocated. You must not activate a node if linking failed! It is
+ * safe to deactivate it, though.
+ *
+ * Once you linked a node, you must call kdbus_node_deactivate() before you drop
+ * the last reference (even if you never activate the node).
+ *
+ * Return: 0 on success. negative error otherwise.
+ */
+int kdbus_node_link(struct kdbus_node *node, struct kdbus_node *parent,
+ const char *name)
+{
+ int ret;
+
+ if (WARN_ON(node->type != KDBUS_NODE_DOMAIN && !parent))
+ return -EINVAL;
+
+ if (WARN_ON(parent && !name))
+ return -EINVAL;
+
+ if (name) {
+ node->name = kstrdup(name, GFP_KERNEL);
+ if (!node->name)
+ return -ENOMEM;
+
+ node->hash = kdbus_node_name_hash(name);
+ }
+
+ ret = ida_simple_get(&kdbus_node_ida, 1, 0, GFP_KERNEL);
+ if (ret < 0)
+ return ret;
+
+ node->id = ret;
+ ret = 0;
+
+ if (parent) {
+ struct rb_node **n, *prev;
+
+ if (!kdbus_node_acquire(parent))
+ return -ESHUTDOWN;
+
+ mutex_lock(&parent->lock);
+
+ n = &parent->children.rb_node;
+ prev = NULL;
+
+ while (*n) {
+ struct kdbus_node *pos;
+ int result;
+
+ pos = kdbus_node_from_rb(*n);
+ prev = *n;
+ result = kdbus_node_name_compare(node->hash,
+ node->name,
+ pos);
+ if (result == 0) {
+ ret = -EEXIST;
+ goto exit_unlock;
+ }
+
+ if (result < 0)
+ n = &pos->rb.rb_left;
+ else
+ n = &pos->rb.rb_right;
+ }
+
+ /* add new node and rebalance the tree */
+ rb_link_node(&node->rb, prev, n);
+ rb_insert_color(&node->rb, &parent->children);
+ node->parent = kdbus_node_ref(parent);
+
+exit_unlock:
+ mutex_unlock(&parent->lock);
+ kdbus_node_release(parent);
+ }
+
+ return ret;
+}
+
+/**
+ * kdbus_node_ref() - Acquire object reference
+ * @node: node to acquire reference to (or NULL)
+ *
+ * This acquires a new reference to @node. You must already own a reference when
+ * calling this!
+ * If @node is NULL, this is a no-op.
+ *
+ * Return: @node is returned
+ */
+struct kdbus_node *kdbus_node_ref(struct kdbus_node *node)
+{
+ if (node)
+ atomic_inc(&node->refcnt);
+ return node;
+}
+
+/**
+ * kdbus_node_unref() - Drop object reference
+ * @node: node to drop reference to (or NULL)
+ *
+ * This drops an object reference to @node. You must not access the node if you
+ * no longer own a reference.
+ * If the ref-count drops to 0, the object will be destroyed (->free_cb will be
+ * called).
+ *
+ * If you linked or activated the node, you must deactivate the node before you
+ * drop your last reference! If you didn't link or activate the node, you can
+ * drop any reference you want.
+ *
+ * Note that this calls into ->free_cb() and thus _might_ sleep. The ->free_cb()
+ * callbacks must not acquire any outer locks, though. So you can safely drop
+ * references while holding locks.
+ *
+ * If @node is NULL, this is a no-op.
+ *
+ * Return: This always returns NULL
+ */
+struct kdbus_node *kdbus_node_unref(struct kdbus_node *node)
+{
+ if (node && atomic_dec_and_test(&node->refcnt)) {
+ struct kdbus_node safe = *node;
+
+ WARN_ON(atomic_read(&node->active) != KDBUS_NODE_DRAINED);
+ WARN_ON(!RB_EMPTY_NODE(&node->rb));
+
+ if (node->free_cb)
+ node->free_cb(node);
+ if (safe.id > 0)
+ ida_simple_remove(&kdbus_node_ida, safe.id);
+
+ kfree(safe.name);
+
+ /*
+ * kdbusfs relies on the parent to be available even after the
+ * node was deactivated and unlinked. Therefore, we pin it
+ * until a node is destroyed.
+ */
+ kdbus_node_unref(safe.parent);
+ }
+
+ return NULL;
+}
+
+/**
+ * kdbus_node_is_active() - test whether a node is active
+ * @node: node to test
+ *
+ * This checks whether @node is active. That means, @node was linked and
+ * activated by the node owner and hasn't been deactivated, yet. If, and only
+ * if, a node is active, kdbus_node_acquire() will be able to acquire active
+ * references.
+ *
+ * Note that this function does not give any lifetime guarantees. After this
+ * call returns, the node might be deactivated immediately. Normally, what you
+ * want is to acquire a real active reference via kdbus_node_acquire().
+ *
+ * Return: true if @node is active, false otherwise
+ */
+bool kdbus_node_is_active(struct kdbus_node *node)
+{
+ return atomic_read(&node->active) >= 0;
+}
+
+/**
+ * kdbus_node_is_deactivated() - test whether a node was already deactivated
+ * @node: node to test
+ *
+ * This checks whether kdbus_node_deactivate() was called on @node. Note that
+ * this might be true even if you never deactivated the node directly, but only
+ * one of its ancestors.
+ *
+ * Note that even if this returns 'false', the node might get deactivated
+ * immediately after the call returns.
+ *
+ * Return: true if @node was already deactivated, false if not
+ */
+bool kdbus_node_is_deactivated(struct kdbus_node *node)
+{
+ int v;
+
+ v = atomic_read(&node->active);
+ return v != KDBUS_NODE_NEW && v < 0;
+}
+
+/**
+ * kdbus_node_activate() - activate a node
+ * @node: node to activate
+ *
+ * This marks @node as active if, and only if, the node wasn't activated nor
+ * deactivated, yet, and the parent is still active. Any but the first call to
+ * kdbus_node_activate() is a no-op.
+ * If you called kdbus_node_deactivate() before, then even the first call to
+ * kdbus_node_activate() will be a no-op.
+ *
+ * This call doesn't give any lifetime guarantees. The node might get
+ * deactivated immediately after this call returns. Or the parent might already
+ * be deactivated, which will make this call a no-op.
+ *
+ * If this call successfully activated a node, it will take an object reference
+ * to it. This reference is dropped after the node is deactivated. Therefore,
+ * the object owner can safely drop their reference to @node iff they know that
+ * its parent node will get deactivated at some point. Once the parent node is
+ * deactivated, it will deactivate all its child and thus drop this reference
+ * again.
+ *
+ * Return: True if this call successfully activated the node, otherwise false.
+ * Note that this might return false, even if the node is still active
+ * (eg., if you called this a second time).
+ */
+bool kdbus_node_activate(struct kdbus_node *node)
+{
+ bool res = false;
+
+ mutex_lock(&node->lock);
+ if (atomic_read(&node->active) == KDBUS_NODE_NEW) {
+ atomic_sub(KDBUS_NODE_NEW, &node->active);
+ /* activated nodes have ref +1 */
+ kdbus_node_ref(node);
+ res = true;
+ }
+ mutex_unlock(&node->lock);
+
+ return res;
+}
+
+/**
+ * kdbus_node_deactivate() - deactivate a node
+ * @node: The node to deactivate.
+ *
+ * This function recursively deactivates this node and all its children. It
+ * returns only once all children and the node itself were recursively disabled
+ * (even if you call this function multiple times in parallel).
+ *
+ * It is safe to call this function on _any_ node that was initialized _any_
+ * number of times.
+ *
+ * This call may sleep, as it waits for all active references to be dropped.
+ */
+void kdbus_node_deactivate(struct kdbus_node *node)
+{
+ struct kdbus_node *pos, *child;
+ struct rb_node *rb;
+ int v_pre, v_post;
+
+ pos = node;
+
+ /*
+ * To avoid recursion, we perform back-tracking while deactivating
+ * nodes. For each node we enter, we first mark the active-counter as
+ * deactivated by adding BIAS. If the node as children, we set the first
+ * child as current position and start over. If the node has no
+ * children, we drain the node by waiting for all active refs to be
+ * dropped and then releasing the node.
+ *
+ * After the node is released, we set its parent as current position
+ * and start over. If the current position was the initial node, we're
+ * done.
+ *
+ * Note that this function can be called in parallel by multiple
+ * callers. We make sure that each node is only released once, and any
+ * racing caller will wait until the other thread fully released that
+ * node.
+ */
+
+ for (;;) {
+ /*
+ * Add BIAS to node->active to mark it as inactive. If it was
+ * never active before, immediately mark it as RELEASE_INACTIVE
+ * so we remember this state.
+ * We cannot remember v_pre as we might iterate into the
+ * children, overwriting v_pre, before we can release our node.
+ */
+ mutex_lock(&pos->lock);
+ v_pre = atomic_read(&pos->active);
+ if (v_pre >= 0)
+ atomic_add_return(KDBUS_NODE_BIAS, &pos->active);
+ else if (v_pre == KDBUS_NODE_NEW)
+ atomic_set(&pos->active, KDBUS_NODE_RELEASE_DIRECT);
+ mutex_unlock(&pos->lock);
+
+ /* wait until all active references were dropped */
+ wait_event(pos->waitq,
+ atomic_read(&pos->active) <= KDBUS_NODE_BIAS);
+
+ mutex_lock(&pos->lock);
+ /* recurse into first child if any */
+ rb = rb_first(&pos->children);
+ if (rb) {
+ child = kdbus_node_ref(kdbus_node_from_rb(rb));
+ mutex_unlock(&pos->lock);
+ pos = child;
+ continue;
+ }
+
+ /* mark object as RELEASE */
+ v_post = atomic_read(&pos->active);
+ if (v_post == KDBUS_NODE_BIAS ||
+ v_post == KDBUS_NODE_RELEASE_DIRECT)
+ atomic_set(&pos->active, KDBUS_NODE_RELEASE);
+ mutex_unlock(&pos->lock);
+
+ /*
+ * If this is the thread that marked the object as RELEASE, we
+ * perform the actual release. Otherwise, we wait until the
+ * release is done and the node is marked as DRAINED.
+ */
+ if (v_post == KDBUS_NODE_BIAS ||
+ v_post == KDBUS_NODE_RELEASE_DIRECT) {
+ if (pos->release_cb)
+ pos->release_cb(pos, v_post == KDBUS_NODE_BIAS);
+
+ if (pos->parent) {
+ mutex_lock(&pos->parent->lock);
+ if (!RB_EMPTY_NODE(&pos->rb)) {
+ rb_erase(&pos->rb,
+ &pos->parent->children);
+ RB_CLEAR_NODE(&pos->rb);
+ }
+ mutex_unlock(&pos->parent->lock);
+ }
+
+ /* mark as DRAINED */
+ atomic_set(&pos->active, KDBUS_NODE_DRAINED);
+ wake_up_all(&pos->waitq);
+
+ /* drop VFS cache */
+ kdbus_fs_flush(pos);
+
+ /*
+ * If the node was activated and someone subtracted BIAS
+ * from it to deactivate it, we, and only us, are
+ * responsible to release the extra ref-count that was
+ * taken once in kdbus_node_activate().
+ * If the node was never activated, no-one ever
+ * subtracted BIAS, but instead skipped that state and
+ * immediately went to NODE_RELEASE_DIRECT. In that case
+ * we must not drop the reference.
+ */
+ if (v_post == KDBUS_NODE_BIAS)
+ kdbus_node_unref(pos);
+ } else {
+ /* wait until object is DRAINED */
+ wait_event(pos->waitq,
+ atomic_read(&pos->active) == KDBUS_NODE_DRAINED);
+ }
+
+ /*
+ * We're done with the current node. Continue on its parent
+ * again, which will try deactivating its next child, or itself
+ * if no child is left.
+ * If we've reached our initial node again, we are done and
+ * can safely return.
+ */
+ if (pos == node)
+ break;
+
+ child = pos;
+ pos = pos->parent;
+ kdbus_node_unref(child);
+ }
+}
+
+/**
+ * kdbus_node_acquire() - Acquire an active ref on a node
+ * @node: The node
+ *
+ * This acquires an active-reference to @node. This will only succeed if the
+ * node is active. You must release this active reference via
+ * kdbus_node_release() again.
+ *
+ * See the introduction to "active references" for more details.
+ *
+ * Return: %true if @node was non-NULL and active
+ */
+bool kdbus_node_acquire(struct kdbus_node *node)
+{
+ return node && atomic_inc_unless_negative(&node->active);
+}
+
+/**
+ * kdbus_node_release() - Release an active ref on a node
+ * @node: The node
+ *
+ * This releases an active reference that was previously acquired via
+ * kdbus_node_acquire(). See kdbus_node_acquire() for details.
+ */
+void kdbus_node_release(struct kdbus_node *node)
+{
+ if (node && atomic_dec_return(&node->active) == KDBUS_NODE_BIAS)
+ wake_up(&node->waitq);
+}
+
+/**
+ * kdbus_node_find_child() - Find child by name
+ * @node: parent node to search through
+ * @name: name of child node
+ *
+ * This searches through all children of @node for a child-node with name @name.
+ * If not found, or if the child is deactivated, NULL is returned. Otherwise,
+ * the child is acquired and a new reference is returned.
+ *
+ * If you're done with the child, you need to release it and drop your
+ * reference.
+ *
+ * This function does not acquire the parent node. However, if the parent was
+ * already deactivated, then kdbus_node_deactivate() will, at some point, also
+ * deactivate the child. Therefore, we can rely on the explicit ordering during
+ * deactivation.
+ *
+ * Return: Reference to acquired child node, or NULL if not found / not active.
+ */
+struct kdbus_node *kdbus_node_find_child(struct kdbus_node *node,
+ const char *name)
+{
+ struct kdbus_node *child;
+ struct rb_node *rb;
+ unsigned int hash;
+ int ret;
+
+ hash = kdbus_node_name_hash(name);
+
+ mutex_lock(&node->lock);
+ rb = node->children.rb_node;
+ while (rb) {
+ child = kdbus_node_from_rb(rb);
+ ret = kdbus_node_name_compare(hash, name, child);
+ if (ret < 0)
+ rb = rb->rb_left;
+ else if (ret > 0)
+ rb = rb->rb_right;
+ else
+ break;
+ }
+ if (rb && kdbus_node_acquire(child))
+ kdbus_node_ref(child);
+ else
+ child = NULL;
+ mutex_unlock(&node->lock);
+
+ return child;
+}
+
+static struct kdbus_node *node_find_closest_unlocked(struct kdbus_node *node,
+ unsigned int hash,
+ const char *name)
+{
+ struct kdbus_node *n, *pos = NULL;
+ struct rb_node *rb;
+ int res;
+
+ /*
+ * Find the closest child with ``node->hash >= hash'', or, if @name is
+ * valid, ``node->name >= name'' (where '>=' is the lex. order).
+ */
+
+ rb = node->children.rb_node;
+ while (rb) {
+ n = kdbus_node_from_rb(rb);
+
+ if (name)
+ res = kdbus_node_name_compare(hash, name, n);
+ else
+ res = hash - n->hash;
+
+ if (res <= 0) {
+ rb = rb->rb_left;
+ pos = n;
+ } else { /* ``hash > n->hash'', ``name > n->name'' */
+ rb = rb->rb_right;
+ }
+ }
+
+ return pos;
+}
+
+/**
+ * kdbus_node_find_closest() - Find closest child-match
+ * @node: parent node to search through
+ * @hash: hash value to find closest match for
+ *
+ * Find the closest child of @node with a hash greater than or equal to @hash.
+ * The closest match is the left-most child of @node with this property. Which
+ * means, it is the first child with that hash returned by
+ * kdbus_node_next_child(), if you'd iterate the whole parent node.
+ *
+ * Return: Reference to acquired child, or NULL if none found.
+ */
+struct kdbus_node *kdbus_node_find_closest(struct kdbus_node *node,
+ unsigned int hash)
+{
+ struct kdbus_node *child;
+ struct rb_node *rb;
+
+ mutex_lock(&node->lock);
+
+ child = node_find_closest_unlocked(node, hash, NULL);
+ while (child && !kdbus_node_acquire(child)) {
+ rb = rb_next(&child->rb);
+ if (rb)
+ child = kdbus_node_from_rb(rb);
+ else
+ child = NULL;
+ }
+ kdbus_node_ref(child);
+
+ mutex_unlock(&node->lock);
+
+ return child;
+}
+
+/**
+ * kdbus_node_next_child() - Acquire next child
+ * @node: parent node
+ * @prev: previous child-node position or NULL
+ *
+ * This function returns a reference to the next active child of @node, after
+ * the passed position @prev. If @prev is NULL, a reference to the first active
+ * child is returned. If no more active children are found, NULL is returned.
+ *
+ * This function acquires the next child it returns. If you're done with the
+ * returned pointer, you need to release _and_ unref it.
+ *
+ * The passed in pointer @prev is not modified by this function, and it does
+ * *not* have to be active. If @prev was acquired via different means, or if it
+ * was unlinked from its parent before you pass it in, then this iterator will
+ * still return the next active child (it will have to search through the
+ * rb-tree based on the node-name, though).
+ * However, @prev must not be linked to a different parent than @node!
+ *
+ * Return: Reference to next acquired child, or NULL if at the end.
+ */
+struct kdbus_node *kdbus_node_next_child(struct kdbus_node *node,
+ struct kdbus_node *prev)
+{
+ struct kdbus_node *pos = NULL;
+ struct rb_node *rb;
+
+ mutex_lock(&node->lock);
+
+ if (!prev) {
+ /*
+ * New iteration; find first node in rb-tree and try to acquire
+ * it. If we got it, directly return it as first element.
+ * Otherwise, the loop below will find the next active node.
+ */
+ rb = rb_first(&node->children);
+ if (!rb)
+ goto exit;
+ pos = kdbus_node_from_rb(rb);
+ if (kdbus_node_acquire(pos))
+ goto exit;
+ } else if (RB_EMPTY_NODE(&prev->rb)) {
+ /*
+ * The current iterator is no longer linked to the rb-tree. Use
+ * its hash value and name to find the next _higher_ node and
+ * acquire it. If we got it, return it as next element.
+ * Otherwise, the loop below will find the next active node.
+ */
+ pos = node_find_closest_unlocked(node, prev->hash, prev->name);
+ if (!pos)
+ goto exit;
+ if (kdbus_node_acquire(pos))
+ goto exit;
+ } else {
+ /*
+ * The current iterator is still linked to the parent. Set it
+ * as current position and use the loop below to find the next
+ * active element.
+ */
+ pos = prev;
+ }
+
+ /* @pos was already returned or is inactive; find next active node */
+ do {
+ rb = rb_next(&pos->rb);
+ if (rb)
+ pos = kdbus_node_from_rb(rb);
+ else
+ pos = NULL;
+ } while (pos && !kdbus_node_acquire(pos));
+
+exit:
+ /* @pos is NULL or acquired. Take ref if non-NULL and return it */
+ kdbus_node_ref(pos);
+ mutex_unlock(&node->lock);
+ return pos;
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_NODE_H
+#define __KDBUS_NODE_H
+
+#include <linux/atomic.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/wait.h>
+
+struct kdbus_node;
+
+enum kdbus_node_type {
+ KDBUS_NODE_DOMAIN,
+ KDBUS_NODE_CONTROL,
+ KDBUS_NODE_BUS,
+ KDBUS_NODE_ENDPOINT,
+};
+
+typedef void (*kdbus_node_free_t) (struct kdbus_node *node);
+typedef void (*kdbus_node_release_t) (struct kdbus_node *node, bool was_active);
+
+struct kdbus_node {
+ atomic_t refcnt;
+ atomic_t active;
+ wait_queue_head_t waitq;
+
+ /* static members */
+ unsigned int type;
+ kdbus_node_free_t free_cb;
+ kdbus_node_release_t release_cb;
+ umode_t mode;
+ kuid_t uid;
+ kgid_t gid;
+
+ /* valid once linked */
+ char *name;
+ unsigned int hash;
+ unsigned int id;
+ struct kdbus_node *parent; /* may be NULL */
+
+ /* valid iff active */
+ struct mutex lock;
+ struct rb_node rb;
+ struct rb_root children;
+};
+
+#define kdbus_node_from_rb(_node) rb_entry((_node), struct kdbus_node, rb)
+
+extern struct ida kdbus_node_ida;
+
+void kdbus_node_init(struct kdbus_node *node, unsigned int type);
+
+int kdbus_node_link(struct kdbus_node *node, struct kdbus_node *parent,
+ const char *name);
+
+struct kdbus_node *kdbus_node_ref(struct kdbus_node *node);
+struct kdbus_node *kdbus_node_unref(struct kdbus_node *node);
+
+bool kdbus_node_is_active(struct kdbus_node *node);
+bool kdbus_node_is_deactivated(struct kdbus_node *node);
+bool kdbus_node_activate(struct kdbus_node *node);
+void kdbus_node_deactivate(struct kdbus_node *node);
+
+bool kdbus_node_acquire(struct kdbus_node *node);
+void kdbus_node_release(struct kdbus_node *node);
+
+struct kdbus_node *kdbus_node_find_child(struct kdbus_node *node,
+ const char *name);
+struct kdbus_node *kdbus_node_find_closest(struct kdbus_node *node,
+ unsigned int hash);
+struct kdbus_node *kdbus_node_next_child(struct kdbus_node *node,
+ struct kdbus_node *prev);
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "domain.h"
+#include "endpoint.h"
+#include "item.h"
+#include "message.h"
+#include "notify.h"
+
+static inline void kdbus_notify_add_tail(struct kdbus_staging *staging,
+ struct kdbus_bus *bus)
+{
+ spin_lock(&bus->notify_lock);
+ list_add_tail(&staging->notify_entry, &bus->notify_list);
+ spin_unlock(&bus->notify_lock);
+}
+
+static int kdbus_notify_reply(struct kdbus_bus *bus, u64 id,
+ u64 cookie, u64 msg_type)
+{
+ struct kdbus_staging *s;
+
+ s = kdbus_staging_new_kernel(bus, id, cookie, 0, msg_type);
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+
+ kdbus_notify_add_tail(s, bus);
+ return 0;
+}
+
+/**
+ * kdbus_notify_reply_timeout() - queue a timeout reply
+ * @bus: Bus which queues the messages
+ * @id: The destination's connection ID
+ * @cookie: The cookie to set in the reply.
+ *
+ * Queues a message that has a KDBUS_ITEM_REPLY_TIMEOUT item attached.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int kdbus_notify_reply_timeout(struct kdbus_bus *bus, u64 id, u64 cookie)
+{
+ return kdbus_notify_reply(bus, id, cookie, KDBUS_ITEM_REPLY_TIMEOUT);
+}
+
+/**
+ * kdbus_notify_reply_dead() - queue a 'dead' reply
+ * @bus: Bus which queues the messages
+ * @id: The destination's connection ID
+ * @cookie: The cookie to set in the reply.
+ *
+ * Queues a message that has a KDBUS_ITEM_REPLY_DEAD item attached.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int kdbus_notify_reply_dead(struct kdbus_bus *bus, u64 id, u64 cookie)
+{
+ return kdbus_notify_reply(bus, id, cookie, KDBUS_ITEM_REPLY_DEAD);
+}
+
+/**
+ * kdbus_notify_name_change() - queue a notification about a name owner change
+ * @bus: Bus which queues the messages
+ * @type: The type if the notification; KDBUS_ITEM_NAME_ADD,
+ * KDBUS_ITEM_NAME_CHANGE or KDBUS_ITEM_NAME_REMOVE
+ * @old_id: The id of the connection that used to own the name
+ * @new_id: The id of the new owner connection
+ * @old_flags: The flags to pass in the KDBUS_ITEM flags field for
+ * the old owner
+ * @new_flags: The flags to pass in the KDBUS_ITEM flags field for
+ * the new owner
+ * @name: The name that was removed or assigned to a new owner
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int kdbus_notify_name_change(struct kdbus_bus *bus, u64 type,
+ u64 old_id, u64 new_id,
+ u64 old_flags, u64 new_flags,
+ const char *name)
+{
+ size_t name_len, extra_size;
+ struct kdbus_staging *s;
+
+ name_len = strlen(name) + 1;
+ extra_size = sizeof(struct kdbus_notify_name_change) + name_len;
+
+ s = kdbus_staging_new_kernel(bus, KDBUS_DST_ID_BROADCAST, 0,
+ extra_size, type);
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+
+ s->notify->name_change.old_id.id = old_id;
+ s->notify->name_change.old_id.flags = old_flags;
+ s->notify->name_change.new_id.id = new_id;
+ s->notify->name_change.new_id.flags = new_flags;
+ memcpy(s->notify->name_change.name, name, name_len);
+
+ kdbus_notify_add_tail(s, bus);
+ return 0;
+}
+
+/**
+ * kdbus_notify_id_change() - queue a notification about a unique ID change
+ * @bus: Bus which queues the messages
+ * @type: The type if the notification; KDBUS_ITEM_ID_ADD or
+ * KDBUS_ITEM_ID_REMOVE
+ * @id: The id of the connection that was added or removed
+ * @flags: The flags to pass in the KDBUS_ITEM flags field
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int kdbus_notify_id_change(struct kdbus_bus *bus, u64 type, u64 id, u64 flags)
+{
+ struct kdbus_staging *s;
+ size_t extra_size;
+
+ extra_size = sizeof(struct kdbus_notify_id_change);
+ s = kdbus_staging_new_kernel(bus, KDBUS_DST_ID_BROADCAST, 0,
+ extra_size, type);
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+
+ s->notify->id_change.id = id;
+ s->notify->id_change.flags = flags;
+
+ kdbus_notify_add_tail(s, bus);
+ return 0;
+}
+
+/**
+ * kdbus_notify_flush() - send a list of collected messages
+ * @bus: Bus which queues the messages
+ *
+ * The list is empty after sending the messages.
+ */
+void kdbus_notify_flush(struct kdbus_bus *bus)
+{
+ LIST_HEAD(notify_list);
+ struct kdbus_staging *s, *tmp;
+
+ mutex_lock(&bus->notify_flush_lock);
+ down_read(&bus->name_registry->rwlock);
+
+ spin_lock(&bus->notify_lock);
+ list_splice_init(&bus->notify_list, ¬ify_list);
+ spin_unlock(&bus->notify_lock);
+
+ list_for_each_entry_safe(s, tmp, ¬ify_list, notify_entry) {
+ if (s->msg->dst_id != KDBUS_DST_ID_BROADCAST) {
+ struct kdbus_conn *conn;
+
+ conn = kdbus_bus_find_conn_by_id(bus, s->msg->dst_id);
+ if (conn) {
+ kdbus_bus_eavesdrop(bus, NULL, s);
+ kdbus_conn_entry_insert(NULL, conn, s, NULL,
+ NULL);
+ kdbus_conn_unref(conn);
+ }
+ } else {
+ kdbus_bus_broadcast(bus, NULL, s);
+ }
+
+ list_del(&s->notify_entry);
+ kdbus_staging_free(s);
+ }
+
+ up_read(&bus->name_registry->rwlock);
+ mutex_unlock(&bus->notify_flush_lock);
+}
+
+/**
+ * kdbus_notify_free() - free a list of collected messages
+ * @bus: Bus which queues the messages
+ */
+void kdbus_notify_free(struct kdbus_bus *bus)
+{
+ struct kdbus_staging *s, *tmp;
+
+ list_for_each_entry_safe(s, tmp, &bus->notify_list, notify_entry) {
+ list_del(&s->notify_entry);
+ kdbus_staging_free(s);
+ }
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_NOTIFY_H
+#define __KDBUS_NOTIFY_H
+
+struct kdbus_bus;
+
+int kdbus_notify_id_change(struct kdbus_bus *bus, u64 type, u64 id, u64 flags);
+int kdbus_notify_reply_timeout(struct kdbus_bus *bus, u64 id, u64 cookie);
+int kdbus_notify_reply_dead(struct kdbus_bus *bus, u64 id, u64 cookie);
+int kdbus_notify_name_change(struct kdbus_bus *bus, u64 type,
+ u64 old_id, u64 new_id,
+ u64 old_flags, u64 new_flags,
+ const char *name);
+void kdbus_notify_flush(struct kdbus_bus *bus);
+void kdbus_notify_free(struct kdbus_bus *bus);
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/cred.h>
+#include <linux/dcache.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "domain.h"
+#include "item.h"
+#include "names.h"
+#include "policy.h"
+
+#define KDBUS_POLICY_HASH_SIZE 64
+
+/**
+ * struct kdbus_policy_db_entry_access - a database entry access item
+ * @type: One of KDBUS_POLICY_ACCESS_* types
+ * @access: Access to grant. One of KDBUS_POLICY_*
+ * @uid: For KDBUS_POLICY_ACCESS_USER, the global uid
+ * @gid: For KDBUS_POLICY_ACCESS_GROUP, the global gid
+ * @list: List entry item for the entry's list
+ *
+ * This is the internal version of struct kdbus_policy_db_access.
+ */
+struct kdbus_policy_db_entry_access {
+ u8 type; /* USER, GROUP, WORLD */
+ u8 access; /* OWN, TALK, SEE */
+ union {
+ kuid_t uid; /* global uid */
+ kgid_t gid; /* global gid */
+ };
+ struct list_head list;
+};
+
+/**
+ * struct kdbus_policy_db_entry - a policy database entry
+ * @name: The name to match the policy entry against
+ * @hentry: The hash entry for the database's entries_hash
+ * @access_list: List head for keeping tracks of the entry's
+ * access items.
+ * @owner: The owner of this entry. Can be a kdbus_conn or
+ * a kdbus_ep object.
+ * @wildcard: The name is a wildcard, such as ending on '.*'
+ */
+struct kdbus_policy_db_entry {
+ char *name;
+ struct hlist_node hentry;
+ struct list_head access_list;
+ const void *owner;
+ bool wildcard:1;
+};
+
+static void kdbus_policy_entry_free(struct kdbus_policy_db_entry *e)
+{
+ struct kdbus_policy_db_entry_access *a, *tmp;
+
+ list_for_each_entry_safe(a, tmp, &e->access_list, list) {
+ list_del(&a->list);
+ kfree(a);
+ }
+
+ kfree(e->name);
+ kfree(e);
+}
+
+static unsigned int kdbus_strnhash(const char *str, size_t len)
+{
+ unsigned long hash = init_name_hash(0);
+
+ while (len--)
+ hash = partial_name_hash(*str++, hash);
+
+ return end_name_hash(hash);
+}
+
+static const struct kdbus_policy_db_entry *
+kdbus_policy_lookup(struct kdbus_policy_db *db, const char *name, u32 hash)
+{
+ struct kdbus_policy_db_entry *e;
+ const char *dot;
+ size_t len;
+
+ /* find exact match */
+ hash_for_each_possible(db->entries_hash, e, hentry, hash)
+ if (strcmp(e->name, name) == 0 && !e->wildcard)
+ return e;
+
+ /* find wildcard match */
+
+ dot = strrchr(name, '.');
+ if (!dot)
+ return NULL;
+
+ len = dot - name;
+ hash = kdbus_strnhash(name, len);
+
+ hash_for_each_possible(db->entries_hash, e, hentry, hash)
+ if (e->wildcard && !strncmp(e->name, name, len) &&
+ !e->name[len])
+ return e;
+
+ return NULL;
+}
+
+/**
+ * kdbus_policy_db_clear - release all memory from a policy db
+ * @db: The policy database
+ */
+void kdbus_policy_db_clear(struct kdbus_policy_db *db)
+{
+ struct kdbus_policy_db_entry *e;
+ struct hlist_node *tmp;
+ unsigned int i;
+
+ /* purge entries */
+ down_write(&db->entries_rwlock);
+ hash_for_each_safe(db->entries_hash, i, tmp, e, hentry) {
+ hash_del(&e->hentry);
+ kdbus_policy_entry_free(e);
+ }
+ up_write(&db->entries_rwlock);
+}
+
+/**
+ * kdbus_policy_db_init() - initialize a new policy database
+ * @db: The location of the database
+ *
+ * This initializes a new policy-db. The underlying memory must have been
+ * cleared to zero by the caller.
+ */
+void kdbus_policy_db_init(struct kdbus_policy_db *db)
+{
+ hash_init(db->entries_hash);
+ init_rwsem(&db->entries_rwlock);
+}
+
+/**
+ * kdbus_policy_query_unlocked() - Query the policy database
+ * @db: Policy database
+ * @cred: Credentials to test against
+ * @name: Name to query
+ * @hash: Hash value of @name
+ *
+ * Same as kdbus_policy_query() but requires the caller to lock the policy
+ * database against concurrent writes.
+ *
+ * Return: The highest KDBUS_POLICY_* access type found, or -EPERM if none.
+ */
+int kdbus_policy_query_unlocked(struct kdbus_policy_db *db,
+ const struct cred *cred, const char *name,
+ unsigned int hash)
+{
+ struct kdbus_policy_db_entry_access *a;
+ const struct kdbus_policy_db_entry *e;
+ int i, highest = -EPERM;
+
+ e = kdbus_policy_lookup(db, name, hash);
+ if (!e)
+ return -EPERM;
+
+ list_for_each_entry(a, &e->access_list, list) {
+ if ((int)a->access <= highest)
+ continue;
+
+ switch (a->type) {
+ case KDBUS_POLICY_ACCESS_USER:
+ if (uid_eq(cred->euid, a->uid))
+ highest = a->access;
+ break;
+ case KDBUS_POLICY_ACCESS_GROUP:
+ if (gid_eq(cred->egid, a->gid)) {
+ highest = a->access;
+ break;
+ }
+
+ for (i = 0; i < cred->group_info->ngroups; i++) {
+ kgid_t gid = cred->group_info->gid[i];
+
+ if (gid_eq(gid, a->gid)) {
+ highest = a->access;
+ break;
+ }
+ }
+
+ break;
+ case KDBUS_POLICY_ACCESS_WORLD:
+ highest = a->access;
+ break;
+ }
+
+ /* OWN is the highest possible policy */
+ if (highest >= KDBUS_POLICY_OWN)
+ break;
+ }
+
+ return highest;
+}
+
+/**
+ * kdbus_policy_query() - Query the policy database
+ * @db: Policy database
+ * @cred: Credentials to test against
+ * @name: Name to query
+ * @hash: Hash value of @name
+ *
+ * Query the policy database @db for the access rights of @cred to the name
+ * @name. The access rights of @cred are returned, or -EPERM if no access is
+ * granted.
+ *
+ * This call effectively searches for the highest access-right granted to
+ * @cred. The caller should really cache those as policy lookups are rather
+ * expensive.
+ *
+ * Return: The highest KDBUS_POLICY_* access type found, or -EPERM if none.
+ */
+int kdbus_policy_query(struct kdbus_policy_db *db, const struct cred *cred,
+ const char *name, unsigned int hash)
+{
+ int ret;
+
+ down_read(&db->entries_rwlock);
+ ret = kdbus_policy_query_unlocked(db, cred, name, hash);
+ up_read(&db->entries_rwlock);
+
+ return ret;
+}
+
+static void __kdbus_policy_remove_owner(struct kdbus_policy_db *db,
+ const void *owner)
+{
+ struct kdbus_policy_db_entry *e;
+ struct hlist_node *tmp;
+ int i;
+
+ hash_for_each_safe(db->entries_hash, i, tmp, e, hentry)
+ if (e->owner == owner) {
+ hash_del(&e->hentry);
+ kdbus_policy_entry_free(e);
+ }
+}
+
+/**
+ * kdbus_policy_remove_owner() - remove all entries related to a connection
+ * @db: The policy database
+ * @owner: The connection which items to remove
+ */
+void kdbus_policy_remove_owner(struct kdbus_policy_db *db,
+ const void *owner)
+{
+ down_write(&db->entries_rwlock);
+ __kdbus_policy_remove_owner(db, owner);
+ up_write(&db->entries_rwlock);
+}
+
+/*
+ * Convert user provided policy access to internal kdbus policy
+ * access
+ */
+static struct kdbus_policy_db_entry_access *
+kdbus_policy_make_access(const struct kdbus_policy_access *uaccess)
+{
+ int ret;
+ struct kdbus_policy_db_entry_access *a;
+
+ a = kzalloc(sizeof(*a), GFP_KERNEL);
+ if (!a)
+ return ERR_PTR(-ENOMEM);
+
+ ret = -EINVAL;
+ switch (uaccess->access) {
+ case KDBUS_POLICY_SEE:
+ case KDBUS_POLICY_TALK:
+ case KDBUS_POLICY_OWN:
+ a->access = uaccess->access;
+ break;
+ default:
+ goto err;
+ }
+
+ switch (uaccess->type) {
+ case KDBUS_POLICY_ACCESS_USER:
+ a->uid = make_kuid(current_user_ns(), uaccess->id);
+ if (!uid_valid(a->uid))
+ goto err;
+
+ break;
+ case KDBUS_POLICY_ACCESS_GROUP:
+ a->gid = make_kgid(current_user_ns(), uaccess->id);
+ if (!gid_valid(a->gid))
+ goto err;
+
+ break;
+ case KDBUS_POLICY_ACCESS_WORLD:
+ break;
+ default:
+ goto err;
+ }
+
+ a->type = uaccess->type;
+
+ return a;
+
+err:
+ kfree(a);
+ return ERR_PTR(ret);
+}
+
+/**
+ * kdbus_policy_set() - set a connection's policy rules
+ * @db: The policy database
+ * @items: A list of kdbus_item elements that contain both
+ * names and access rules to set.
+ * @items_size: The total size of the items.
+ * @max_policies: The maximum number of policy entries to allow.
+ * Pass 0 for no limit.
+ * @allow_wildcards: Boolean value whether wildcard entries (such
+ * ending on '.*') should be allowed.
+ * @owner: The owner of the new policy items.
+ *
+ * This function sets a new set of policies for a given owner. The names and
+ * access rules are gathered by walking the list of items passed in as
+ * argument. An item of type KDBUS_ITEM_NAME is expected before any number of
+ * KDBUS_ITEM_POLICY_ACCESS items. If there are more repetitions of this
+ * pattern than denoted in @max_policies, -EINVAL is returned.
+ *
+ * In order to allow atomic replacement of rules, the function first removes
+ * all entries that have been created for the given owner previously.
+ *
+ * Callers to this function must make sure that the owner is a custom
+ * endpoint, or if the endpoint is a default endpoint, then it must be
+ * either a policy holder or an activator.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int kdbus_policy_set(struct kdbus_policy_db *db,
+ const struct kdbus_item *items,
+ size_t items_size,
+ size_t max_policies,
+ bool allow_wildcards,
+ const void *owner)
+{
+ struct kdbus_policy_db_entry_access *a;
+ struct kdbus_policy_db_entry *e, *p;
+ const struct kdbus_item *item;
+ struct hlist_node *tmp;
+ HLIST_HEAD(entries);
+ HLIST_HEAD(restore);
+ size_t count = 0;
+ int i, ret = 0;
+ u32 hash;
+
+ /* Walk the list of items and look for new policies */
+ e = NULL;
+ KDBUS_ITEMS_FOREACH(item, items, items_size) {
+ switch (item->type) {
+ case KDBUS_ITEM_NAME: {
+ size_t len;
+
+ if (max_policies && ++count > max_policies) {
+ ret = -E2BIG;
+ goto exit;
+ }
+
+ if (!kdbus_name_is_valid(item->str, true)) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ e = kzalloc(sizeof(*e), GFP_KERNEL);
+ if (!e) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ INIT_LIST_HEAD(&e->access_list);
+ e->owner = owner;
+ hlist_add_head(&e->hentry, &entries);
+
+ e->name = kstrdup(item->str, GFP_KERNEL);
+ if (!e->name) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ /*
+ * If a supplied name ends with an '.*', cut off that
+ * part, only store anything before it, and mark the
+ * entry as wildcard.
+ */
+ len = strlen(e->name);
+ if (len > 2 &&
+ e->name[len - 3] == '.' &&
+ e->name[len - 2] == '*') {
+ if (!allow_wildcards) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ e->name[len - 3] = '\0';
+ e->wildcard = true;
+ }
+
+ break;
+ }
+
+ case KDBUS_ITEM_POLICY_ACCESS:
+ if (!e) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ a = kdbus_policy_make_access(&item->policy_access);
+ if (IS_ERR(a)) {
+ ret = PTR_ERR(a);
+ goto exit;
+ }
+
+ list_add_tail(&a->list, &e->access_list);
+ break;
+ }
+ }
+
+ down_write(&db->entries_rwlock);
+
+ /* remember previous entries to restore in case of failure */
+ hash_for_each_safe(db->entries_hash, i, tmp, e, hentry)
+ if (e->owner == owner) {
+ hash_del(&e->hentry);
+ hlist_add_head(&e->hentry, &restore);
+ }
+
+ hlist_for_each_entry_safe(e, tmp, &entries, hentry) {
+ /* prevent duplicates */
+ hash = kdbus_strhash(e->name);
+ hash_for_each_possible(db->entries_hash, p, hentry, hash)
+ if (strcmp(e->name, p->name) == 0 &&
+ e->wildcard == p->wildcard) {
+ ret = -EEXIST;
+ goto restore;
+ }
+
+ hlist_del(&e->hentry);
+ hash_add(db->entries_hash, &e->hentry, hash);
+ }
+
+restore:
+ /* if we failed, flush all entries we added so far */
+ if (ret < 0)
+ __kdbus_policy_remove_owner(db, owner);
+
+ /* if we failed, restore entries, otherwise release them */
+ hlist_for_each_entry_safe(e, tmp, &restore, hentry) {
+ hlist_del(&e->hentry);
+ if (ret < 0) {
+ hash = kdbus_strhash(e->name);
+ hash_add(db->entries_hash, &e->hentry, hash);
+ } else {
+ kdbus_policy_entry_free(e);
+ }
+ }
+
+ up_write(&db->entries_rwlock);
+
+exit:
+ hlist_for_each_entry_safe(e, tmp, &entries, hentry) {
+ hlist_del(&e->hentry);
+ kdbus_policy_entry_free(e);
+ }
+
+ return ret;
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_POLICY_H
+#define __KDBUS_POLICY_H
+
+#include <linux/hashtable.h>
+#include <linux/rwsem.h>
+
+struct kdbus_conn;
+struct kdbus_item;
+
+/**
+ * struct kdbus_policy_db - policy database
+ * @entries_hash: Hashtable of entries
+ * @entries_rwlock: Mutex to protect the database's access entries
+ */
+struct kdbus_policy_db {
+ DECLARE_HASHTABLE(entries_hash, 6);
+ struct rw_semaphore entries_rwlock;
+};
+
+void kdbus_policy_db_init(struct kdbus_policy_db *db);
+void kdbus_policy_db_clear(struct kdbus_policy_db *db);
+
+int kdbus_policy_query_unlocked(struct kdbus_policy_db *db,
+ const struct cred *cred, const char *name,
+ unsigned int hash);
+int kdbus_policy_query(struct kdbus_policy_db *db, const struct cred *cred,
+ const char *name, unsigned int hash);
+
+void kdbus_policy_remove_owner(struct kdbus_policy_db *db,
+ const void *owner);
+int kdbus_policy_set(struct kdbus_policy_db *db,
+ const struct kdbus_item *items,
+ size_t items_size,
+ size_t max_policies,
+ bool allow_wildcards,
+ const void *owner);
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/aio.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/highmem.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <linux/rbtree.h>
+#include <linux/sched.h>
+#include <linux/shmem_fs.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+
+#include "pool.h"
+#include "util.h"
+
+/**
+ * struct kdbus_pool - the receiver's buffer
+ * @f: The backing shmem file
+ * @size: The size of the file
+ * @accounted_size: Currently accounted memory in bytes
+ * @lock: Pool data lock
+ * @slices: All slices sorted by address
+ * @slices_busy: Tree of allocated slices
+ * @slices_free: Tree of free slices
+ *
+ * The receiver's buffer, managed as a pool of allocated and free
+ * slices containing the queued messages.
+ *
+ * Messages sent with KDBUS_CMD_SEND are copied directly by the
+ * sending process into the receiver's pool.
+ *
+ * Messages received with KDBUS_CMD_RECV just return the offset
+ * to the data placed in the pool.
+ *
+ * The internally allocated memory needs to be returned by the receiver
+ * with KDBUS_CMD_FREE.
+ */
+struct kdbus_pool {
+ struct file *f;
+ size_t size;
+ size_t accounted_size;
+ struct mutex lock;
+
+ struct list_head slices;
+ struct rb_root slices_busy;
+ struct rb_root slices_free;
+};
+
+/**
+ * struct kdbus_pool_slice - allocated element in kdbus_pool
+ * @pool: Pool this slice belongs to
+ * @off: Offset of slice in the shmem file
+ * @size: Size of slice
+ * @entry: Entry in "all slices" list
+ * @rb_node: Entry in free or busy list
+ * @free: Unused slice
+ * @accounted: Accounted as queue slice
+ * @ref_kernel: Kernel holds a reference
+ * @ref_user: Userspace holds a reference
+ *
+ * The pool has one or more slices, always spanning the entire size of the
+ * pool.
+ *
+ * Every slice is an element in a list sorted by the buffer address, to
+ * provide access to the next neighbor slice.
+ *
+ * Every slice is member in either the busy or the free tree. The free
+ * tree is organized by slice size, the busy tree organized by buffer
+ * offset.
+ */
+struct kdbus_pool_slice {
+ struct kdbus_pool *pool;
+ size_t off;
+ size_t size;
+
+ struct list_head entry;
+ struct rb_node rb_node;
+
+ bool free:1;
+ bool accounted:1;
+ bool ref_kernel:1;
+ bool ref_user:1;
+};
+
+static struct kdbus_pool_slice *kdbus_pool_slice_new(struct kdbus_pool *pool,
+ size_t off, size_t size)
+{
+ struct kdbus_pool_slice *slice;
+
+ slice = kzalloc(sizeof(*slice), GFP_KERNEL);
+ if (!slice)
+ return NULL;
+
+ slice->pool = pool;
+ slice->off = off;
+ slice->size = size;
+ slice->free = true;
+ return slice;
+}
+
+/* insert a slice into the free tree */
+static void kdbus_pool_add_free_slice(struct kdbus_pool *pool,
+ struct kdbus_pool_slice *slice)
+{
+ struct rb_node **n;
+ struct rb_node *pn = NULL;
+
+ n = &pool->slices_free.rb_node;
+ while (*n) {
+ struct kdbus_pool_slice *pslice;
+
+ pn = *n;
+ pslice = rb_entry(pn, struct kdbus_pool_slice, rb_node);
+ if (slice->size < pslice->size)
+ n = &pn->rb_left;
+ else
+ n = &pn->rb_right;
+ }
+
+ rb_link_node(&slice->rb_node, pn, n);
+ rb_insert_color(&slice->rb_node, &pool->slices_free);
+}
+
+/* insert a slice into the busy tree */
+static void kdbus_pool_add_busy_slice(struct kdbus_pool *pool,
+ struct kdbus_pool_slice *slice)
+{
+ struct rb_node **n;
+ struct rb_node *pn = NULL;
+
+ n = &pool->slices_busy.rb_node;
+ while (*n) {
+ struct kdbus_pool_slice *pslice;
+
+ pn = *n;
+ pslice = rb_entry(pn, struct kdbus_pool_slice, rb_node);
+ if (slice->off < pslice->off)
+ n = &pn->rb_left;
+ else if (slice->off > pslice->off)
+ n = &pn->rb_right;
+ else
+ BUG();
+ }
+
+ rb_link_node(&slice->rb_node, pn, n);
+ rb_insert_color(&slice->rb_node, &pool->slices_busy);
+}
+
+static struct kdbus_pool_slice *kdbus_pool_find_slice(struct kdbus_pool *pool,
+ size_t off)
+{
+ struct rb_node *n;
+
+ n = pool->slices_busy.rb_node;
+ while (n) {
+ struct kdbus_pool_slice *s;
+
+ s = rb_entry(n, struct kdbus_pool_slice, rb_node);
+ if (off < s->off)
+ n = n->rb_left;
+ else if (off > s->off)
+ n = n->rb_right;
+ else
+ return s;
+ }
+
+ return NULL;
+}
+
+/**
+ * kdbus_pool_slice_alloc() - allocate memory from a pool
+ * @pool: The receiver's pool
+ * @size: The number of bytes to allocate
+ * @accounted: Whether this slice should be accounted for
+ *
+ * The returned slice is used for kdbus_pool_slice_release() to
+ * free the allocated memory. If either @kvec or @iovec is non-NULL, the data
+ * will be copied from kernel or userspace memory into the new slice at
+ * offset 0.
+ *
+ * Return: the allocated slice on success, ERR_PTR on failure.
+ */
+struct kdbus_pool_slice *kdbus_pool_slice_alloc(struct kdbus_pool *pool,
+ size_t size, bool accounted)
+{
+ size_t slice_size = KDBUS_ALIGN8(size);
+ struct rb_node *n, *found = NULL;
+ struct kdbus_pool_slice *s;
+ int ret = 0;
+
+ if (WARN_ON(!size))
+ return ERR_PTR(-EINVAL);
+
+ /* search a free slice with the closest matching size */
+ mutex_lock(&pool->lock);
+ n = pool->slices_free.rb_node;
+ while (n) {
+ s = rb_entry(n, struct kdbus_pool_slice, rb_node);
+ if (slice_size < s->size) {
+ found = n;
+ n = n->rb_left;
+ } else if (slice_size > s->size) {
+ n = n->rb_right;
+ } else {
+ found = n;
+ break;
+ }
+ }
+
+ /* no slice with the minimum size found in the pool */
+ if (!found) {
+ ret = -EXFULL;
+ goto exit_unlock;
+ }
+
+ /* no exact match, use the closest one */
+ if (!n) {
+ struct kdbus_pool_slice *s_new;
+
+ s = rb_entry(found, struct kdbus_pool_slice, rb_node);
+
+ /* split-off the remainder of the size to its own slice */
+ s_new = kdbus_pool_slice_new(pool, s->off + slice_size,
+ s->size - slice_size);
+ if (!s_new) {
+ ret = -ENOMEM;
+ goto exit_unlock;
+ }
+
+ list_add(&s_new->entry, &s->entry);
+ kdbus_pool_add_free_slice(pool, s_new);
+
+ /* adjust our size now that we split-off another slice */
+ s->size = slice_size;
+ }
+
+ /* move slice from free to the busy tree */
+ rb_erase(found, &pool->slices_free);
+ kdbus_pool_add_busy_slice(pool, s);
+
+ WARN_ON(s->ref_kernel || s->ref_user);
+
+ s->ref_kernel = true;
+ s->free = false;
+ s->accounted = accounted;
+ if (accounted)
+ pool->accounted_size += s->size;
+ mutex_unlock(&pool->lock);
+
+ return s;
+
+exit_unlock:
+ mutex_unlock(&pool->lock);
+ return ERR_PTR(ret);
+}
+
+static void __kdbus_pool_slice_release(struct kdbus_pool_slice *slice)
+{
+ struct kdbus_pool *pool = slice->pool;
+
+ /* don't free the slice if either has a reference */
+ if (slice->ref_kernel || slice->ref_user)
+ return;
+
+ if (WARN_ON(slice->free))
+ return;
+
+ rb_erase(&slice->rb_node, &pool->slices_busy);
+
+ /* merge with the next free slice */
+ if (!list_is_last(&slice->entry, &pool->slices)) {
+ struct kdbus_pool_slice *s;
+
+ s = list_entry(slice->entry.next,
+ struct kdbus_pool_slice, entry);
+ if (s->free) {
+ rb_erase(&s->rb_node, &pool->slices_free);
+ list_del(&s->entry);
+ slice->size += s->size;
+ kfree(s);
+ }
+ }
+
+ /* merge with previous free slice */
+ if (pool->slices.next != &slice->entry) {
+ struct kdbus_pool_slice *s;
+
+ s = list_entry(slice->entry.prev,
+ struct kdbus_pool_slice, entry);
+ if (s->free) {
+ rb_erase(&s->rb_node, &pool->slices_free);
+ list_del(&slice->entry);
+ s->size += slice->size;
+ kfree(slice);
+ slice = s;
+ }
+ }
+
+ slice->free = true;
+ kdbus_pool_add_free_slice(pool, slice);
+}
+
+/**
+ * kdbus_pool_slice_release() - drop kernel-reference on allocated slice
+ * @slice: Slice allocated from the pool
+ *
+ * This releases the kernel-reference on the given slice. If the
+ * kernel-reference and the user-reference on a slice are dropped, the slice is
+ * returned to the pool.
+ *
+ * So far, we do not implement full ref-counting on slices. Each, kernel and
+ * user-space can have exactly one reference to a slice. If both are dropped at
+ * the same time, the slice is released.
+ */
+void kdbus_pool_slice_release(struct kdbus_pool_slice *slice)
+{
+ struct kdbus_pool *pool;
+
+ if (!slice)
+ return;
+
+ /* @slice may be freed, so keep local ptr to @pool */
+ pool = slice->pool;
+
+ mutex_lock(&pool->lock);
+ /* kernel must own a ref to @slice to drop it */
+ WARN_ON(!slice->ref_kernel);
+ slice->ref_kernel = false;
+ /* no longer kernel-owned, de-account slice */
+ if (slice->accounted && !WARN_ON(pool->accounted_size < slice->size))
+ pool->accounted_size -= slice->size;
+ __kdbus_pool_slice_release(slice);
+ mutex_unlock(&pool->lock);
+}
+
+/**
+ * kdbus_pool_release_offset() - release a public offset
+ * @pool: pool to operate on
+ * @off: offset to release
+ *
+ * This should be called whenever user-space frees a slice given to them. It
+ * verifies the slice is available and public, and then drops it. It ensures
+ * correct locking and barriers against queues.
+ *
+ * Return: 0 on success, ENXIO if the offset is invalid or not public.
+ */
+int kdbus_pool_release_offset(struct kdbus_pool *pool, size_t off)
+{
+ struct kdbus_pool_slice *slice;
+ int ret = 0;
+
+ /* 'pool->size' is used as dummy offset for empty slices */
+ if (off == pool->size)
+ return 0;
+
+ mutex_lock(&pool->lock);
+ slice = kdbus_pool_find_slice(pool, off);
+ if (slice && slice->ref_user) {
+ slice->ref_user = false;
+ __kdbus_pool_slice_release(slice);
+ } else {
+ ret = -ENXIO;
+ }
+ mutex_unlock(&pool->lock);
+
+ return ret;
+}
+
+/**
+ * kdbus_pool_publish_empty() - publish empty slice to user-space
+ * @pool: pool to operate on
+ * @off: output storage for offset, or NULL
+ * @size: output storage for size, or NULL
+ *
+ * This is the same as kdbus_pool_slice_publish(), but uses a dummy slice with
+ * size 0. The returned offset points to the end of the pool and is never
+ * returned on real slices.
+ */
+void kdbus_pool_publish_empty(struct kdbus_pool *pool, u64 *off, u64 *size)
+{
+ if (off)
+ *off = pool->size;
+ if (size)
+ *size = 0;
+}
+
+/**
+ * kdbus_pool_slice_publish() - publish slice to user-space
+ * @slice: The slice
+ * @out_offset: Output storage for offset, or NULL
+ * @out_size: Output storage for size, or NULL
+ *
+ * This prepares a slice to be published to user-space.
+ *
+ * This call combines the following operations:
+ * * the memory region is flushed so the user's memory view is consistent
+ * * the slice is marked as referenced by user-space, so user-space has to
+ * call KDBUS_CMD_FREE to release it
+ * * the offset and size of the slice are written to the given output
+ * arguments, if non-NULL
+ */
+void kdbus_pool_slice_publish(struct kdbus_pool_slice *slice,
+ u64 *out_offset, u64 *out_size)
+{
+ mutex_lock(&slice->pool->lock);
+ /* kernel must own a ref to @slice to gain a user-space ref */
+ WARN_ON(!slice->ref_kernel);
+ slice->ref_user = true;
+ mutex_unlock(&slice->pool->lock);
+
+ if (out_offset)
+ *out_offset = slice->off;
+ if (out_size)
+ *out_size = slice->size;
+}
+
+/**
+ * kdbus_pool_slice_offset() - Get a slice's offset inside the pool
+ * @slice: Slice to return the offset of
+ *
+ * Return: The internal offset @slice inside the pool.
+ */
+off_t kdbus_pool_slice_offset(const struct kdbus_pool_slice *slice)
+{
+ return slice->off;
+}
+
+/**
+ * kdbus_pool_slice_size() - get size of a pool slice
+ * @slice: slice to query
+ *
+ * Return: size of the given slice
+ */
+size_t kdbus_pool_slice_size(const struct kdbus_pool_slice *slice)
+{
+ return slice->size;
+}
+
+/**
+ * kdbus_pool_new() - create a new pool
+ * @name: Name of the (deleted) file which shows up in
+ * /proc, used for debugging
+ * @size: Maximum size of the pool
+ *
+ * Return: a new kdbus_pool on success, ERR_PTR on failure.
+ */
+struct kdbus_pool *kdbus_pool_new(const char *name, size_t size)
+{
+ struct kdbus_pool_slice *s;
+ struct kdbus_pool *p;
+ struct file *f;
+ char *n = NULL;
+ int ret;
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return ERR_PTR(-ENOMEM);
+
+ if (name) {
+ n = kasprintf(GFP_KERNEL, KBUILD_MODNAME "-conn:%s", name);
+ if (!n) {
+ ret = -ENOMEM;
+ goto exit_free;
+ }
+ }
+
+ f = shmem_file_setup(n ?: KBUILD_MODNAME "-conn", size, 0);
+ kfree(n);
+
+ if (IS_ERR(f)) {
+ ret = PTR_ERR(f);
+ goto exit_free;
+ }
+
+ ret = get_write_access(file_inode(f));
+ if (ret < 0)
+ goto exit_put_shmem;
+
+ /* allocate first slice spanning the entire pool */
+ s = kdbus_pool_slice_new(p, 0, size);
+ if (!s) {
+ ret = -ENOMEM;
+ goto exit_put_write;
+ }
+
+ p->f = f;
+ p->size = size;
+ p->slices_free = RB_ROOT;
+ p->slices_busy = RB_ROOT;
+ mutex_init(&p->lock);
+
+ INIT_LIST_HEAD(&p->slices);
+ list_add(&s->entry, &p->slices);
+
+ kdbus_pool_add_free_slice(p, s);
+ return p;
+
+exit_put_write:
+ put_write_access(file_inode(f));
+exit_put_shmem:
+ fput(f);
+exit_free:
+ kfree(p);
+ return ERR_PTR(ret);
+}
+
+/**
+ * kdbus_pool_free() - destroy pool
+ * @pool: The receiver's pool
+ */
+void kdbus_pool_free(struct kdbus_pool *pool)
+{
+ struct kdbus_pool_slice *s, *tmp;
+
+ if (!pool)
+ return;
+
+ list_for_each_entry_safe(s, tmp, &pool->slices, entry) {
+ list_del(&s->entry);
+ kfree(s);
+ }
+
+ put_write_access(file_inode(pool->f));
+ fput(pool->f);
+ kfree(pool);
+}
+
+/**
+ * kdbus_pool_accounted() - retrieve accounting information
+ * @pool: pool to query
+ * @size: output for overall pool size
+ * @acc: output for currently accounted size
+ *
+ * This returns accounting information of the pool. Note that the data might
+ * change after the function returns, as the pool lock is dropped. You need to
+ * protect the data via other means, if you need reliable accounting.
+ */
+void kdbus_pool_accounted(struct kdbus_pool *pool, size_t *size, size_t *acc)
+{
+ mutex_lock(&pool->lock);
+ if (size)
+ *size = pool->size;
+ if (acc)
+ *acc = pool->accounted_size;
+ mutex_unlock(&pool->lock);
+}
+
+/**
+ * kdbus_pool_slice_copy_iovec() - copy user memory to a slice
+ * @slice: The slice to write to
+ * @off: Offset in the slice to write to
+ * @iov: iovec array, pointing to data to copy
+ * @iov_len: Number of elements in @iov
+ * @total_len: Total number of bytes described in members of @iov
+ *
+ * User memory referenced by @iov will be copied into @slice at offset @off.
+ *
+ * Return: the numbers of bytes copied, negative errno on failure.
+ */
+ssize_t
+kdbus_pool_slice_copy_iovec(const struct kdbus_pool_slice *slice, loff_t off,
+ struct iovec *iov, size_t iov_len, size_t total_len)
+{
+ struct iov_iter iter;
+ ssize_t len;
+
+ if (WARN_ON(off + total_len > slice->size))
+ return -EFAULT;
+
+ off += slice->off;
+ iov_iter_init(&iter, WRITE, iov, iov_len, total_len);
+ len = vfs_iter_write(slice->pool->f, &iter, &off, 0);
+
+ return (len >= 0 && len != total_len) ? -EFAULT : len;
+}
+
+/**
+ * kdbus_pool_slice_copy_kvec() - copy kernel memory to a slice
+ * @slice: The slice to write to
+ * @off: Offset in the slice to write to
+ * @kvec: kvec array, pointing to data to copy
+ * @kvec_len: Number of elements in @kvec
+ * @total_len: Total number of bytes described in members of @kvec
+ *
+ * Kernel memory referenced by @kvec will be copied into @slice at offset @off.
+ *
+ * Return: the numbers of bytes copied, negative errno on failure.
+ */
+ssize_t kdbus_pool_slice_copy_kvec(const struct kdbus_pool_slice *slice,
+ loff_t off, struct kvec *kvec,
+ size_t kvec_len, size_t total_len)
+{
+ struct iov_iter iter;
+ mm_segment_t old_fs;
+ ssize_t len;
+
+ if (WARN_ON(off + total_len > slice->size))
+ return -EFAULT;
+
+ off += slice->off;
+ iov_iter_kvec(&iter, WRITE, kvec, kvec_len, total_len);
+
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ len = vfs_iter_write(slice->pool->f, &iter, &off, 0);
+ set_fs(old_fs);
+
+ return (len >= 0 && len != total_len) ? -EFAULT : len;
+}
+
+/**
+ * kdbus_pool_slice_copy() - copy data from one slice into another
+ * @slice_dst: destination slice
+ * @slice_src: source slice
+ *
+ * Return: 0 on success, negative error number on failure.
+ */
+int kdbus_pool_slice_copy(const struct kdbus_pool_slice *slice_dst,
+ const struct kdbus_pool_slice *slice_src)
+{
+ struct file *f_src = slice_src->pool->f;
+ struct file *f_dst = slice_dst->pool->f;
+ struct inode *i_dst = file_inode(f_dst);
+ struct address_space *mapping_dst = f_dst->f_mapping;
+ const struct address_space_operations *aops = mapping_dst->a_ops;
+ unsigned long len = slice_src->size;
+ loff_t off_src = slice_src->off;
+ loff_t off_dst = slice_dst->off;
+ mm_segment_t old_fs;
+ int ret = 0;
+
+ if (WARN_ON(slice_src->size != slice_dst->size) ||
+ WARN_ON(slice_src->free || slice_dst->free))
+ return -EINVAL;
+
+ inode_lock(i_dst);
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ while (len > 0) {
+ unsigned long page_off;
+ unsigned long copy_len;
+ char __user *kaddr;
+ struct page *page;
+ ssize_t n_read;
+ void *fsdata;
+ long status;
+
+ page_off = off_dst & (PAGE_SIZE - 1);
+ copy_len = min_t(unsigned long,
+ PAGE_SIZE - page_off, len);
+
+ status = aops->write_begin(f_dst, mapping_dst, off_dst,
+ copy_len, 0, &page, &fsdata);
+ if (unlikely(status < 0)) {
+ ret = status;
+ break;
+ }
+
+ kaddr = (char __force __user *)kmap(page) + page_off;
+ n_read = kernel_read(f_src, kaddr, copy_len, &off_src);
+ kunmap(page);
+ mark_page_accessed(page);
+ flush_dcache_page(page);
+
+ if (unlikely(n_read != copy_len)) {
+ ret = -EFAULT;
+ break;
+ }
+
+ status = aops->write_end(f_dst, mapping_dst, off_dst,
+ copy_len, copy_len, page, fsdata);
+ if (unlikely(status != copy_len)) {
+ ret = -EFAULT;
+ break;
+ }
+
+ off_dst += copy_len;
+ len -= copy_len;
+ }
+ set_fs(old_fs);
+ inode_unlock(i_dst);
+
+ return ret;
+}
+
+/**
+ * kdbus_pool_mmap() - map the pool into the process
+ * @pool: The receiver's pool
+ * @vma: passed by mmap() syscall
+ *
+ * Return: the result of the mmap() call, negative errno on failure.
+ */
+int kdbus_pool_mmap(const struct kdbus_pool *pool, struct vm_area_struct *vma)
+{
+ /* deny write access to the pool */
+ if (vma->vm_flags & VM_WRITE)
+ return -EPERM;
+ vma->vm_flags &= ~VM_MAYWRITE;
+
+ /* do not allow to map more than the size of the file */
+ if ((vma->vm_end - vma->vm_start) > pool->size)
+ return -EFAULT;
+
+ /* replace the connection file with our shmem file */
+ if (vma->vm_file)
+ fput(vma->vm_file);
+ vma->vm_file = get_file(pool->f);
+
+ return pool->f->f_op->mmap(pool->f, vma);
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_POOL_H
+#define __KDBUS_POOL_H
+
+#include <linux/uio.h>
+
+struct kdbus_pool;
+struct kdbus_pool_slice;
+
+struct kdbus_pool *kdbus_pool_new(const char *name, size_t size);
+void kdbus_pool_free(struct kdbus_pool *pool);
+void kdbus_pool_accounted(struct kdbus_pool *pool, size_t *size, size_t *acc);
+int kdbus_pool_mmap(const struct kdbus_pool *pool, struct vm_area_struct *vma);
+int kdbus_pool_release_offset(struct kdbus_pool *pool, size_t off);
+void kdbus_pool_publish_empty(struct kdbus_pool *pool, u64 *off, u64 *size);
+
+struct kdbus_pool_slice *kdbus_pool_slice_alloc(struct kdbus_pool *pool,
+ size_t size, bool accounted);
+void kdbus_pool_slice_release(struct kdbus_pool_slice *slice);
+void kdbus_pool_slice_publish(struct kdbus_pool_slice *slice,
+ u64 *out_offset, u64 *out_size);
+off_t kdbus_pool_slice_offset(const struct kdbus_pool_slice *slice);
+size_t kdbus_pool_slice_size(const struct kdbus_pool_slice *slice);
+int kdbus_pool_slice_copy(const struct kdbus_pool_slice *slice_dst,
+ const struct kdbus_pool_slice *slice_src);
+ssize_t kdbus_pool_slice_copy_kvec(const struct kdbus_pool_slice *slice,
+ loff_t off, struct kvec *kvec,
+ size_t kvec_count, size_t total_len);
+ssize_t kdbus_pool_slice_copy_iovec(const struct kdbus_pool_slice *slice,
+ loff_t off, struct iovec *iov,
+ size_t iov_count, size_t total_len);
+
+#endif
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/audit.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/hashtable.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/math64.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+#include <linux/uio.h>
+
+#include "util.h"
+#include "domain.h"
+#include "connection.h"
+#include "item.h"
+#include "message.h"
+#include "metadata.h"
+#include "queue.h"
+#include "reply.h"
+
+/**
+ * kdbus_queue_init() - initialize data structure related to a queue
+ * @queue: The queue to initialize
+ */
+void kdbus_queue_init(struct kdbus_queue *queue)
+{
+ INIT_LIST_HEAD(&queue->msg_list);
+ queue->msg_prio_queue = RB_ROOT;
+}
+
+/**
+ * kdbus_queue_peek() - Retrieves an entry from a queue
+ * @queue: The queue
+ * @priority: The minimum priority of the entry to peek
+ * @use_priority: Boolean flag whether or not to peek by priority
+ *
+ * Look for a entry in a queue, either by priority, or the oldest one (FIFO).
+ * The entry is not freed, put off the queue's lists or anything else.
+ *
+ * Return: the peeked queue entry on success, NULL if no suitable msg is found
+ */
+struct kdbus_queue_entry *kdbus_queue_peek(struct kdbus_queue *queue,
+ s64 priority, bool use_priority)
+{
+ struct kdbus_queue_entry *e;
+
+ if (list_empty(&queue->msg_list))
+ return NULL;
+
+ if (use_priority) {
+ /* get next entry with highest priority */
+ e = rb_entry(queue->msg_prio_highest,
+ struct kdbus_queue_entry, prio_node);
+
+ /* no entry with the requested priority */
+ if (e->priority > priority)
+ return NULL;
+ } else {
+ /* ignore the priority, return the next entry in the entry */
+ e = list_first_entry(&queue->msg_list,
+ struct kdbus_queue_entry, entry);
+ }
+
+ return e;
+}
+
+static void kdbus_queue_entry_link(struct kdbus_queue_entry *entry)
+{
+ struct kdbus_queue *queue = &entry->conn->queue;
+ struct rb_node **n, *pn = NULL;
+ bool highest = true;
+
+ lockdep_assert_held(&entry->conn->lock);
+ if (WARN_ON(!list_empty(&entry->entry)))
+ return;
+
+ /* sort into priority entry tree */
+ n = &queue->msg_prio_queue.rb_node;
+ while (*n) {
+ struct kdbus_queue_entry *e;
+
+ pn = *n;
+ e = rb_entry(pn, struct kdbus_queue_entry, prio_node);
+
+ /* existing node for this priority, add to its list */
+ if (likely(entry->priority == e->priority)) {
+ list_add_tail(&entry->prio_entry, &e->prio_entry);
+ goto prio_done;
+ }
+
+ if (entry->priority < e->priority) {
+ n = &pn->rb_left;
+ } else {
+ n = &pn->rb_right;
+ highest = false;
+ }
+ }
+
+ /* cache highest-priority entry */
+ if (highest)
+ queue->msg_prio_highest = &entry->prio_node;
+
+ /* new node for this priority */
+ rb_link_node(&entry->prio_node, pn, n);
+ rb_insert_color(&entry->prio_node, &queue->msg_prio_queue);
+ INIT_LIST_HEAD(&entry->prio_entry);
+
+prio_done:
+ /* add to unsorted fifo list */
+ list_add_tail(&entry->entry, &queue->msg_list);
+}
+
+static void kdbus_queue_entry_unlink(struct kdbus_queue_entry *entry)
+{
+ struct kdbus_queue *queue = &entry->conn->queue;
+
+ lockdep_assert_held(&entry->conn->lock);
+ if (list_empty(&entry->entry))
+ return;
+
+ list_del_init(&entry->entry);
+
+ if (list_empty(&entry->prio_entry)) {
+ /*
+ * Single entry for this priority, update cached
+ * highest-priority entry, remove the tree node.
+ */
+ if (queue->msg_prio_highest == &entry->prio_node)
+ queue->msg_prio_highest = rb_next(&entry->prio_node);
+
+ rb_erase(&entry->prio_node, &queue->msg_prio_queue);
+ } else {
+ struct kdbus_queue_entry *q;
+
+ /*
+ * Multiple entries for this priority entry, get next one in
+ * the list. Update cached highest-priority entry, store the
+ * new one as the tree node.
+ */
+ q = list_first_entry(&entry->prio_entry,
+ struct kdbus_queue_entry, prio_entry);
+ list_del(&entry->prio_entry);
+
+ if (queue->msg_prio_highest == &entry->prio_node)
+ queue->msg_prio_highest = &q->prio_node;
+
+ rb_replace_node(&entry->prio_node, &q->prio_node,
+ &queue->msg_prio_queue);
+ }
+}
+
+/**
+ * kdbus_queue_entry_new() - allocate a queue entry
+ * @src: source connection, or NULL
+ * @dst: destination connection
+ * @s: staging object carrying the message
+ *
+ * Allocates a queue entry based on a given msg and allocate space for
+ * the message payload and the requested metadata in the connection's pool.
+ * The entry is not actually added to the queue's lists at this point.
+ *
+ * Return: the allocated entry on success, or an ERR_PTR on failures.
+ */
+struct kdbus_queue_entry *kdbus_queue_entry_new(struct kdbus_conn *src,
+ struct kdbus_conn *dst,
+ struct kdbus_staging *s)
+{
+ struct kdbus_queue_entry *entry;
+ int ret;
+
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&entry->entry);
+ entry->priority = s->msg->priority;
+ entry->conn = kdbus_conn_ref(dst);
+ entry->gaps = kdbus_gaps_ref(s->gaps);
+
+ entry->slice = kdbus_staging_emit(s, src, dst);
+ if (IS_ERR(entry->slice)) {
+ ret = PTR_ERR(entry->slice);
+ entry->slice = NULL;
+ goto error;
+ }
+
+ entry->user = src ? kdbus_user_ref(src->user) : NULL;
+ return entry;
+
+error:
+ kdbus_queue_entry_free(entry);
+ return ERR_PTR(ret);
+}
+
+/**
+ * kdbus_queue_entry_free() - free resources of an entry
+ * @entry: The entry to free
+ *
+ * Removes resources allocated by a queue entry, along with the entry itself.
+ * Note that the entry's slice is not freed at this point.
+ */
+void kdbus_queue_entry_free(struct kdbus_queue_entry *entry)
+{
+ if (!entry)
+ return;
+
+ lockdep_assert_held(&entry->conn->lock);
+
+ kdbus_queue_entry_unlink(entry);
+ kdbus_reply_unref(entry->reply);
+
+ if (entry->slice) {
+ kdbus_conn_quota_dec(entry->conn, entry->user,
+ kdbus_pool_slice_size(entry->slice),
+ entry->gaps ? entry->gaps->n_fds : 0);
+ kdbus_pool_slice_release(entry->slice);
+ }
+
+ kdbus_user_unref(entry->user);
+ kdbus_gaps_unref(entry->gaps);
+ kdbus_conn_unref(entry->conn);
+ kfree(entry);
+}
+
+/**
+ * kdbus_queue_entry_install() - install message components into the
+ * receiver's process
+ * @entry: The queue entry to install
+ * @return_flags: Pointer to store the return flags for userspace
+ * @install_fds: Whether or not to install associated file descriptors
+ *
+ * Return: 0 on success.
+ */
+int kdbus_queue_entry_install(struct kdbus_queue_entry *entry,
+ u64 *return_flags, bool install_fds)
+{
+ bool incomplete_fds = false;
+ int ret;
+
+ lockdep_assert_held(&entry->conn->lock);
+
+ ret = kdbus_gaps_install(entry->gaps, entry->slice, &incomplete_fds);
+ if (ret < 0)
+ return ret;
+
+ if (incomplete_fds)
+ *return_flags |= KDBUS_RECV_RETURN_INCOMPLETE_FDS;
+ return 0;
+}
+
+/**
+ * kdbus_queue_entry_enqueue() - enqueue an entry
+ * @entry: entry to enqueue
+ * @reply: reply to link to this entry (or NULL if none)
+ *
+ * This enqueues an unqueued entry into the message queue of the linked
+ * connection. It also binds a reply object to the entry so we can remember it
+ * when the message is moved.
+ *
+ * Once this call returns (and the connection lock is released), this entry can
+ * be dequeued by the target connection. Note that the entry will not be removed
+ * from the queue until it is destroyed.
+ */
+void kdbus_queue_entry_enqueue(struct kdbus_queue_entry *entry,
+ struct kdbus_reply *reply)
+{
+ lockdep_assert_held(&entry->conn->lock);
+
+ if (WARN_ON(entry->reply) || WARN_ON(!list_empty(&entry->entry)))
+ return;
+
+ entry->reply = kdbus_reply_ref(reply);
+ kdbus_queue_entry_link(entry);
+}
+
+/**
+ * kdbus_queue_entry_move() - move queue entry
+ * @e: queue entry to move
+ * @dst: destination connection to queue the entry on
+ *
+ * This moves a queue entry onto a different connection. It allocates a new
+ * slice on the target connection and copies the message over. If the copy
+ * succeeded, we move the entry from @src to @dst.
+ *
+ * On failure, the entry is left untouched.
+ *
+ * The queue entry must be queued right now, and after the call succeeds it will
+ * be queued on the destination, but no longer on the source.
+ *
+ * The caller must hold the connection lock of the source *and* destination.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_queue_entry_move(struct kdbus_queue_entry *e,
+ struct kdbus_conn *dst)
+{
+ struct kdbus_pool_slice *slice = NULL;
+ struct kdbus_conn *src = e->conn;
+ size_t size, fds;
+ int ret;
+
+ lockdep_assert_held(&src->lock);
+ lockdep_assert_held(&dst->lock);
+
+ if (WARN_ON(list_empty(&e->entry)))
+ return -EINVAL;
+ if (src == dst)
+ return 0;
+
+ size = kdbus_pool_slice_size(e->slice);
+ fds = e->gaps ? e->gaps->n_fds : 0;
+
+ ret = kdbus_conn_quota_inc(dst, e->user, size, fds);
+ if (ret < 0)
+ return ret;
+
+ slice = kdbus_pool_slice_alloc(dst->pool, size, true);
+ if (IS_ERR(slice)) {
+ ret = PTR_ERR(slice);
+ slice = NULL;
+ goto error;
+ }
+
+ ret = kdbus_pool_slice_copy(slice, e->slice);
+ if (ret < 0)
+ goto error;
+
+ kdbus_queue_entry_unlink(e);
+ kdbus_conn_quota_dec(src, e->user, size, fds);
+ kdbus_pool_slice_release(e->slice);
+ kdbus_conn_unref(e->conn);
+
+ e->slice = slice;
+ e->conn = kdbus_conn_ref(dst);
+ kdbus_queue_entry_link(e);
+
+ return 0;
+
+error:
+ kdbus_pool_slice_release(slice);
+ kdbus_conn_quota_dec(dst, e->user, size, fds);
+ return ret;
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_QUEUE_H
+#define __KDBUS_QUEUE_H
+
+#include <linux/list.h>
+#include <linux/rbtree.h>
+
+struct kdbus_conn;
+struct kdbus_pool_slice;
+struct kdbus_reply;
+struct kdbus_staging;
+struct kdbus_user;
+
+/**
+ * struct kdbus_queue - a connection's message queue
+ * @msg_list: List head for kdbus_queue_entry objects
+ * @msg_prio_queue: RB tree root for messages, sorted by priority
+ * @msg_prio_highest: Link to the RB node referencing the message with the
+ * highest priority in the tree.
+ */
+struct kdbus_queue {
+ struct list_head msg_list;
+ struct rb_root msg_prio_queue;
+ struct rb_node *msg_prio_highest;
+};
+
+/**
+ * struct kdbus_queue_entry - messages waiting to be read
+ * @entry: Entry in the connection's list
+ * @prio_node: Entry in the priority queue tree
+ * @prio_entry: Queue tree node entry in the list of one priority
+ * @priority: Message priority
+ * @dst_name_id: The sequence number of the name this message is
+ * addressed to, 0 for messages sent to an ID
+ * @conn: Connection this entry is queued on
+ * @gaps: Gaps object to fill message gaps at RECV time
+ * @user: User used for accounting
+ * @slice: Slice in the receiver's pool for the message
+ * @reply: The reply block if a reply to this message is expected
+ */
+struct kdbus_queue_entry {
+ struct list_head entry;
+ struct rb_node prio_node;
+ struct list_head prio_entry;
+
+ s64 priority;
+ u64 dst_name_id;
+
+ struct kdbus_conn *conn;
+ struct kdbus_gaps *gaps;
+ struct kdbus_user *user;
+ struct kdbus_pool_slice *slice;
+ struct kdbus_reply *reply;
+};
+
+void kdbus_queue_init(struct kdbus_queue *queue);
+struct kdbus_queue_entry *kdbus_queue_peek(struct kdbus_queue *queue,
+ s64 priority, bool use_priority);
+
+struct kdbus_queue_entry *kdbus_queue_entry_new(struct kdbus_conn *src,
+ struct kdbus_conn *dst,
+ struct kdbus_staging *s);
+void kdbus_queue_entry_free(struct kdbus_queue_entry *entry);
+int kdbus_queue_entry_install(struct kdbus_queue_entry *entry,
+ u64 *return_flags, bool install_fds);
+void kdbus_queue_entry_enqueue(struct kdbus_queue_entry *entry,
+ struct kdbus_reply *reply);
+int kdbus_queue_entry_move(struct kdbus_queue_entry *entry,
+ struct kdbus_conn *dst);
+
+#endif /* __KDBUS_QUEUE_H */
--- /dev/null
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/uio.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "endpoint.h"
+#include "message.h"
+#include "metadata.h"
+#include "names.h"
+#include "domain.h"
+#include "item.h"
+#include "notify.h"
+#include "policy.h"
+#include "reply.h"
+#include "util.h"
+
+/**
+ * kdbus_reply_new() - Allocate and set up a new kdbus_reply object
+ * @reply_src: The connection a reply is expected from
+ * @reply_dst: The connection this reply object belongs to
+ * @msg: Message associated with the reply
+ * @name_entry: Name entry used to send the message
+ * @sync: Whether or not to make this reply synchronous
+ *
+ * Allocate and fill a new kdbus_reply object.
+ *
+ * Return: New kdbus_conn object on success, ERR_PTR on error.
+ */
+struct kdbus_reply *kdbus_reply_new(struct kdbus_conn *reply_src,
+ struct kdbus_conn *reply_dst,
+ const struct kdbus_msg *msg,
+ struct kdbus_name_entry *name_entry,
+ bool sync)
+{
+ struct kdbus_reply *r;
+ int ret;
+
+ if (atomic_inc_return(&reply_dst->request_count) >
+ KDBUS_CONN_MAX_REQUESTS_PENDING) {
+ ret = -EMLINK;
+ goto exit_dec_request_count;
+ }
+
+ r = kzalloc(sizeof(*r), GFP_KERNEL);
+ if (!r) {
+ ret = -ENOMEM;
+ goto exit_dec_request_count;
+ }
+
+ kref_init(&r->kref);
+ INIT_LIST_HEAD(&r->entry);
+ r->reply_src = kdbus_conn_ref(reply_src);
+ r->reply_dst = kdbus_conn_ref(reply_dst);
+ r->cookie = msg->cookie;
+ r->name_id = name_entry ? name_entry->name_id : 0;
+ r->deadline_ns = msg->timeout_ns;
+
+ if (sync) {
+ r->sync = true;
+ r->waiting = true;
+ }
+
+ return r;
+
+exit_dec_request_count:
+ atomic_dec(&reply_dst->request_count);
+ return ERR_PTR(ret);
+}
+
+static void __kdbus_reply_free(struct kref *kref)
+{
+ struct kdbus_reply *reply =
+ container_of(kref, struct kdbus_reply, kref);
+
+ atomic_dec(&reply->reply_dst->request_count);
+ kdbus_conn_unref(reply->reply_src);
+ kdbus_conn_unref(reply->reply_dst);
+ kfree(reply);
+}
+
+/**
+ * kdbus_reply_ref() - Increase reference on kdbus_reply
+ * @r: The reply, may be %NULL
+ *
+ * Return: The reply object with an extra reference
+ */
+struct kdbus_reply *kdbus_reply_ref(struct kdbus_reply *r)
+{
+ if (r)
+ kref_get(&r->kref);
+ return r;
+}
+
+/**
+ * kdbus_reply_unref() - Decrease reference on kdbus_reply
+ * @r: The reply, may be %NULL
+ *
+ * Return: NULL
+ */
+struct kdbus_reply *kdbus_reply_unref(struct kdbus_reply *r)
+{
+ if (r)
+ kref_put(&r->kref, __kdbus_reply_free);
+ return NULL;
+}
+
+/**
+ * kdbus_reply_link() - Link reply object into target connection
+ * @r: Reply to link
+ */
+void kdbus_reply_link(struct kdbus_reply *r)
+{
+ if (WARN_ON(!list_empty(&r->entry)))
+ return;
+
+ list_add_tail(&r->entry, &r->reply_dst->reply_list);
+ kdbus_reply_ref(r);
+}
+
+/**
+ * kdbus_reply_unlink() - Unlink reply object from target connection
+ * @r: Reply to unlink
+ */
+void kdbus_reply_unlink(struct kdbus_reply *r)
+{
+ if (!list_empty(&r->entry)) {
+ list_del_init(&r->entry);
+ kdbus_reply_unref(r);
+ }
+}
+
+/**
+ * kdbus_sync_reply_wakeup() - Wake a synchronously blocking reply
+ * @reply: The reply object
+ * @err: Error code to set on the remote side
+ *
+ * Wake up remote peer (method origin) with the appropriate synchronous reply
+ * code.
+ */
+void kdbus_sync_reply_wakeup(struct kdbus_reply *reply, int err)
+{
+ if (WARN_ON(!reply->sync))
+ return;
+
+ reply->waiting = false;
+ reply->err = err;
+ wake_up_interruptible(&reply->reply_dst->wait);
+}
+
+/**
+ * kdbus_reply_find() - Find the corresponding reply object
+ * @replying: The replying connection or NULL
+ * @reply_dst: The connection the reply will be sent to
+ * (method origin)
+ * @cookie: The cookie of the requesting message
+ *
+ * Lookup a reply object that should be sent as a reply by
+ * @replying to @reply_dst with the given cookie.
+ *
+ * Callers must take the @reply_dst lock.
+ *
+ * Return: the corresponding reply object or NULL if not found
+ */
+struct kdbus_reply *kdbus_reply_find(struct kdbus_conn *replying,
+ struct kdbus_conn *reply_dst,
+ u64 cookie)
+{
+ struct kdbus_reply *r;
+
+ list_for_each_entry(r, &reply_dst->reply_list, entry) {
+ if (r->cookie == cookie &&
+ (!replying || r->reply_src == replying))
+ return r;
+ }
+
+ return NULL;
+}
+
+/**
+ * kdbus_reply_list_scan_work() - Worker callback to scan the replies of a
+ * connection for exceeded timeouts
+ * @work: Work struct of the connection to scan
+ *
+ * Walk the list of replies stored with a connection and look for entries
+ * that have exceeded their timeout. If such an entry is found, a timeout
+ * notification is sent to the waiting peer, and the reply is removed from
+ * the list.
+ *
+ * The work is rescheduled to the nearest timeout found during the list
+ * iteration.
+ */
+void kdbus_reply_list_scan_work(struct work_struct *work)
+{
+ struct kdbus_conn *conn =
+ container_of(work, struct kdbus_conn, work.work);
+ struct kdbus_reply *reply, *reply_tmp;
+ u64 deadline = ~0ULL;
+ u64 now;
+
+ now = ktime_get_ns();
+
+ mutex_lock(&conn->lock);
+ if (!kdbus_conn_active(conn)) {
+ mutex_unlock(&conn->lock);
+ return;
+ }
+
+ list_for_each_entry_safe(reply, reply_tmp, &conn->reply_list, entry) {
+ /*
+ * If the reply block is waiting for synchronous I/O,
+ * the timeout is handled by wait_event_*_timeout(),
+ * so we don't have to care for it here.
+ */
+ if (reply->sync && !reply->interrupted)
+ continue;
+
+ WARN_ON(reply->reply_dst != conn);
+
+ if (reply->deadline_ns > now) {
+ /* remember next timeout */
+ if (deadline > reply->deadline_ns)
+ deadline = reply->deadline_ns;
+
+ continue;
+ }
+
+ /*
+ * A zero deadline means the connection died, was
+ * cleaned up already and the notification was sent.
+ * Don't send notifications for reply trackers that were
+ * left in an interrupted syscall state.
+ */
+ if (reply->deadline_ns != 0 && !reply->interrupted)
+ kdbus_notify_reply_timeout(conn->ep->bus, conn->id,
+ reply->cookie);
+
+ kdbus_reply_unlink(reply);
+ }
+
+ /* rearm delayed work with next timeout */
+ if (deadline != ~0ULL)
+ schedule_delayed_work(&conn->work,
+ nsecs_to_jiffies(deadline - now));
+
+ mutex_unlock(&conn->lock);
+
+ kdbus_notify_flush(conn->ep->bus);
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_REPLY_H
+#define __KDBUS_REPLY_H
+
+/**
+ * struct kdbus_reply - an entry of kdbus_conn's list of replies
+ * @kref: Ref-count of this object
+ * @entry: The entry of the connection's reply_list
+ * @reply_src: The connection the reply will be sent from
+ * @reply_dst: The connection the reply will be sent to
+ * @queue_entry: The queue entry item that is prepared by the replying
+ * connection
+ * @deadline_ns: The deadline of the reply, in nanoseconds
+ * @cookie: The cookie of the requesting message
+ * @name_id: ID of the well-known name the original msg was sent to
+ * @sync: The reply block is waiting for synchronous I/O
+ * @waiting: The condition to synchronously wait for
+ * @interrupted: The sync reply was left in an interrupted state
+ * @err: The error code for the synchronous reply
+ */
+struct kdbus_reply {
+ struct kref kref;
+ struct list_head entry;
+ struct kdbus_conn *reply_src;
+ struct kdbus_conn *reply_dst;
+ struct kdbus_queue_entry *queue_entry;
+ u64 deadline_ns;
+ u64 cookie;
+ u64 name_id;
+ bool sync:1;
+ bool waiting:1;
+ bool interrupted:1;
+ int err;
+};
+
+struct kdbus_reply *kdbus_reply_new(struct kdbus_conn *reply_src,
+ struct kdbus_conn *reply_dst,
+ const struct kdbus_msg *msg,
+ struct kdbus_name_entry *name_entry,
+ bool sync);
+
+struct kdbus_reply *kdbus_reply_ref(struct kdbus_reply *r);
+struct kdbus_reply *kdbus_reply_unref(struct kdbus_reply *r);
+
+void kdbus_reply_link(struct kdbus_reply *r);
+void kdbus_reply_unlink(struct kdbus_reply *r);
+
+struct kdbus_reply *kdbus_reply_find(struct kdbus_conn *replying,
+ struct kdbus_conn *reply_dst,
+ u64 cookie);
+
+void kdbus_sync_reply_wakeup(struct kdbus_reply *reply, int err);
+void kdbus_reply_list_scan_work(struct work_struct *work);
+
+#endif /* __KDBUS_REPLY_H */
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/capability.h>
+#include <linux/cred.h>
+#include <linux/ctype.h>
+#include <linux/err.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+#include <linux/user_namespace.h>
+
+#include "limits.h"
+#include "util.h"
+
+/**
+ * kdbus_copy_from_user() - copy aligned data from user-space
+ * @dest: target buffer in kernel memory
+ * @user_ptr: user-provided source buffer
+ * @size: memory size to copy from user
+ *
+ * This copies @size bytes from @user_ptr into the kernel, just like
+ * copy_from_user() does. But we enforce an 8-byte alignment and reject any
+ * unaligned user-space pointers.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_copy_from_user(void *dest, void __user *user_ptr, size_t size)
+{
+ if (!KDBUS_IS_ALIGNED8((uintptr_t)user_ptr))
+ return -EFAULT;
+
+ if (copy_from_user(dest, user_ptr, size))
+ return -EFAULT;
+
+ return 0;
+}
+
+/**
+ * kdbus_verify_uid_prefix() - verify UID prefix of a user-supplied name
+ * @name: user-supplied name to verify
+ * @user_ns: user-namespace to act in
+ * @kuid: Kernel internal uid of user
+ *
+ * This verifies that the user-supplied name @name has their UID as prefix. This
+ * is the default name-spacing policy we enforce on user-supplied names for
+ * public kdbus entities like buses and endpoints.
+ *
+ * The user must supply names prefixed with "<UID>-", whereas the UID is
+ * interpreted in the user-namespace of the domain. If the user fails to supply
+ * such a prefixed name, we reject it.
+ *
+ * Return: 0 on success, negative error code on failure
+ */
+int kdbus_verify_uid_prefix(const char *name, struct user_namespace *user_ns,
+ kuid_t kuid)
+{
+ uid_t uid;
+ char prefix[16];
+
+ /*
+ * The kuid must have a mapping into the userns of the domain
+ * otherwise do not allow creation of buses nor endpoints.
+ */
+ uid = from_kuid(user_ns, kuid);
+ if (uid == (uid_t) -1)
+ return -EINVAL;
+
+ snprintf(prefix, sizeof(prefix), "%u-", uid);
+ if (strncmp(name, prefix, strlen(prefix)) != 0)
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * kdbus_sanitize_attach_flags() - Sanitize attach flags from user-space
+ * @flags: Attach flags provided by userspace
+ * @attach_flags: A pointer where to store the valid attach flags
+ *
+ * Convert attach-flags provided by user-space into a valid mask. If the mask
+ * is invalid, an error is returned. The sanitized attach flags are stored in
+ * the output parameter.
+ *
+ * Return: 0 on success, negative error on failure.
+ */
+int kdbus_sanitize_attach_flags(u64 flags, u64 *attach_flags)
+{
+ /* 'any' degrades to 'all' for compatibility */
+ if (flags == _KDBUS_ATTACH_ANY)
+ flags = _KDBUS_ATTACH_ALL;
+
+ /* reject unknown attach flags */
+ if (flags & ~_KDBUS_ATTACH_ALL)
+ return -EINVAL;
+
+ *attach_flags = flags;
+ return 0;
+}
+
+/**
+ * kdbus_kvec_set - helper utility to assemble kvec arrays
+ * @kvec: kvec entry to use
+ * @src: Source address to set in @kvec
+ * @len: Number of bytes in @src
+ * @total_len: Pointer to total length variable
+ *
+ * Set @src and @len in @kvec, and increase @total_len by @len.
+ */
+void kdbus_kvec_set(struct kvec *kvec, void *src, size_t len, u64 *total_len)
+{
+ kvec->iov_base = src;
+ kvec->iov_len = len;
+ *total_len += len;
+}
+
+static const char * const zeros = "\0\0\0\0\0\0\0";
+
+/**
+ * kdbus_kvec_pad - conditionally write a padding kvec
+ * @kvec: kvec entry to use
+ * @len: Total length used for kvec array
+ *
+ * Check if the current total byte length of the array in @len is aligned to
+ * 8 bytes. If it isn't, fill @kvec with padding information and increase @len
+ * by the number of bytes stored in @kvec.
+ *
+ * Return: the number of added padding bytes.
+ */
+size_t kdbus_kvec_pad(struct kvec *kvec, u64 *len)
+{
+ size_t pad = KDBUS_ALIGN8(*len) - *len;
+
+ if (!pad)
+ return 0;
+
+ kvec->iov_base = (void *)zeros;
+ kvec->iov_len = pad;
+
+ *len += pad;
+
+ return pad;
+}
--- /dev/null
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ */
+
+#ifndef __KDBUS_UTIL_H
+#define __KDBUS_UTIL_H
+
+#include <linux/dcache.h>
+#include <linux/ioctl.h>
+#include <linux/stddef.h>
+
+#include <uapi/linux/kdbus.h>
+
+/* all exported addresses are 64 bit */
+#define KDBUS_PTR(addr) ((void __user *)(uintptr_t)(addr))
+
+/* all exported sizes are 64 bit and data aligned to 64 bit */
+#define KDBUS_ALIGN8(s) ALIGN((s), 8)
+#define KDBUS_IS_ALIGNED8(s) (IS_ALIGNED(s, 8))
+
+/**
+ * kdbus_member_set_user - write a structure member to user memory
+ * @_s: Variable to copy from
+ * @_b: Buffer to write to
+ * @_t: Structure type
+ * @_m: Member name in the passed structure
+ *
+ * Return: the result of copy_to_user()
+ */
+#define kdbus_member_set_user(_s, _b, _t, _m) \
+({ \
+ u64 __user *_sz = \
+ (void __user *)((u8 __user *)(_b) + offsetof(_t, _m)); \
+ copy_to_user(_sz, _s, sizeof_field(_t, _m)); \
+})
+
+/**
+ * kdbus_strhash - calculate a hash
+ * @str: String
+ *
+ * Return: hash value
+ */
+static inline unsigned int kdbus_strhash(const char *str)
+{
+ unsigned long hash = init_name_hash(0);
+
+ while (*str)
+ hash = partial_name_hash(*str++, hash);
+
+ return end_name_hash(hash);
+}
+
+int kdbus_verify_uid_prefix(const char *name, struct user_namespace *user_ns,
+ kuid_t kuid);
+int kdbus_sanitize_attach_flags(u64 flags, u64 *attach_flags);
+
+int kdbus_copy_from_user(void *dest, void __user *user_ptr, size_t size);
+
+struct kvec;
+
+void kdbus_kvec_set(struct kvec *kvec, void *src, size_t len, u64 *total_len);
+size_t kdbus_kvec_pad(struct kvec *kvec, u64 *len);
+
+#endif
cp %{SOURCE1} .
%install
-mkdir -p %{buildroot}/usr/src/%{name}
+mkdir -p %{buildroot}/usr/src/%{name}/kdbus
cp kernel/*.[ch] kernel/Makefile COPYING %{buildroot}/usr/src/%{name}
+cp kernel/kdbus/*.[ch] kernel/kdbus/Makefile %{buildroot}/usr/src/%{name}/kdbus
%files
%manifest %{name}.manifest
/usr/src/%{name}/*.c
/usr/src/%{name}/*.h
/usr/src/%{name}/Makefile
+/usr/src/%{name}/kdbus/*.c
+/usr/src/%{name}/kdbus/*.h
+/usr/src/%{name}/kdbus/Makefile
projects / platform / kernel / linux-tizen-modules-source.git / commitdiff