--- /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/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,
+ const u64 *pattach_recv,
+ u64 flags, kuid_t uid, kgid_t gid)
+{
+ struct kdbus_bus *b;
+ u64 attach_owner;
+ u64 attach_recv;
+ 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_recv ? *pattach_recv : 0,
+ &attach_recv);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ 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_req = attach_recv;
+ 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
+ * @kmsg: The message to send.
+ *
+ * Send @kmsg 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_kmsg *kmsg)
+{
+ 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, kmsg);
+
+ down_read(&bus->conn_rwlock);
+ hash_for_each(bus->conn_hash, i, conn_dst, hentry) {
+ if (conn_dst->id == kmsg->msg.src_id)
+ continue;
+ 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_kmsg(conn_dst->match_db, conn_src,
+ kmsg))
+ continue;
+
+ if (conn_src) {
+ u64 attach_flags;
+
+ /*
+ * 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;
+
+ attach_flags = kdbus_meta_calc_attach_flags(conn_src,
+ conn_dst);
+
+ /*
+ * Keep sending messages even if we cannot acquire the
+ * requested metadata. It's up to the receiver to drop
+ * messages that lack expected metadata.
+ */
+ if (!conn_src->faked_meta)
+ kdbus_meta_proc_collect(kmsg->proc_meta,
+ attach_flags);
+ kdbus_meta_conn_collect(kmsg->conn_meta, kmsg, conn_src,
+ attach_flags);
+ } 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,
+ kmsg))
+ continue;
+ }
+
+ ret = kdbus_conn_entry_insert(conn_src, conn_dst, kmsg, 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
+ * @kmsg: The message to send.
+ *
+ * Send @kmsg 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_kmsg *kmsg)
+{
+ 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) {
+ /*
+ * Collect metadata requested by the destination connection.
+ * Ignore errors, as receivers need to check metadata
+ * availability, anyway. So it's still better to send messages
+ * that lack data, than to skip it entirely.
+ */
+ if (conn_src) {
+ u64 attach_flags;
+
+ attach_flags = kdbus_meta_calc_attach_flags(conn_src,
+ conn_dst);
+ if (!conn_src->faked_meta)
+ kdbus_meta_proc_collect(kmsg->proc_meta,
+ attach_flags);
+ kdbus_meta_conn_collect(kmsg->conn_meta, kmsg, conn_src,
+ attach_flags);
+ }
+
+ ret = kdbus_conn_entry_insert(conn_src, conn_dst, kmsg, 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: 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 },
+ { .type = KDBUS_ITEM_ATTACH_FLAGS_RECV },
+ };
+ 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,
+ argv[4].item ? argv[4].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_header item_hdr;
+ struct kdbus_info info = {};
+ size_t meta_size, name_len;
+ struct kvec kvec[5];
+ u64 hdr_size = 0;
+ u64 attach_flags;
+ size_t cnt = 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_export_prepare(bus->creator_meta, NULL,
+ &attach_flags, &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), &hdr_size);
+ kdbus_kvec_set(&kvec[cnt++], &item_hdr, sizeof(item_hdr), &hdr_size);
+ kdbus_kvec_set(&kvec[cnt++], bus->node.name, name_len, &hdr_size);
+ cnt += !!kdbus_kvec_pad(&kvec[cnt], &hdr_size);
+
+ slice = kdbus_pool_slice_alloc(conn->pool, hdr_size + meta_size, false);
+ if (IS_ERR(slice)) {
+ ret = PTR_ERR(slice);
+ slice = NULL;
+ goto exit;
+ }
+
+ ret = kdbus_meta_export(bus->creator_meta, NULL, attach_flags,
+ slice, hdr_size, &meta_size);
+ if (ret < 0)
+ goto exit;
+
+ info.size = hdr_size + meta_size;
+
+ ret = kdbus_pool_slice_copy_kvec(slice, 0, kvec, cnt, hdr_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);
+
+ 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_kmsg;
+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_req: KDBUS_ATTACH_* flags required by connecting peers
+ * @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
+ * @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_req;
+ 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 */
+ 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_kmsg *kmsg);
+void kdbus_bus_eavesdrop(struct kdbus_bus *bus,
+ struct kdbus_conn *conn_src,
+ struct kdbus_kmsg *kmsg);
+
+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/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/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 enpoint 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_cmd_ep_make() - handle KDBUS_CMD_ENDPOINT_MAKE
+ * @bus: bus to operate on
+ * @argp: command payload
+ *
+ * Return: 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: Newly created endpoint on success, ERR_PTR 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 - enpoint 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 enpoint 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);
+
+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