From 3485129b7798ef43d7b5831640784da82d5ccb66 Mon Sep 17 00:00:00 2001
From: Kay Sievers <kay@vrfy.org>
Date: Tue, 14 Jan 2014 15:59:04 +0800
Subject: [PATCH] export namespace-global message sequence number (ABI break)

---
 bus.c             |  3 +--
 bus.h             | 10 ++++------
 connection.c      | 13 ++++++++++---
 endpoint.c        |  2 +-
 handle.c          |  2 +-
 kdbus.h           |  2 ++
 message.c         |  5 +++++
 message.h         |  3 +++
 metadata.c        | 11 +++++++++--
 metadata.h        |  3 +++
 names.c           |  3 +--
 names.h           |  4 ++--
 namespace.c       |  5 +++--
 namespace.h       |  8 ++++++--
 test/kdbus-util.c |  3 ++-
 15 files changed, 53 insertions(+), 24 deletions(-)

diff --git a/bus.c b/bus.c
index 872ddbd..ef0c9a6 100644
--- a/bus.c
+++ b/bus.c
@@ -205,7 +205,6 @@ int kdbus_bus_new(struct kdbus_ns *ns,
 	b->uid_owner = uid;
 	b->bus_flags = make->flags;
 	b->bloom_size = bloom_size;
-	b->conn_id_next = 1; /* connection 0 == kernel */
 	mutex_init(&b->lock);
 	hash_init(b->conn_hash);
 	INIT_LIST_HEAD(&b->ep_list);
@@ -239,7 +238,7 @@ int kdbus_bus_new(struct kdbus_ns *ns,
 
 	/* link into namespace */
 	mutex_lock(&ns->lock);
-	b->id = ns->bus_id_next++;
+	b->id = ++ns->bus_seq_last;
 	list_add_tail(&b->ns_entry, &ns->bus_list);
 	b->ns = kdbus_ns_ref(ns);
 	mutex_unlock(&ns->lock);
diff --git a/bus.h b/bus.h
index 5af1712..87395c7 100644
--- a/bus.h
+++ b/bus.h
@@ -27,9 +27,8 @@
  * @name:		The bus name
  * @id:			ID of this bus in the namespace
  * @lock:		Bus data lock
- * @ep_id_next:		Next endpoint id sequence number
- * @conn_id_next:	Next connection id sequence number
- * @msg_id_next:	Next message id sequence number
+ * @ep_seq_last:	Last used endpoint id sequence number
+ * @conn_seq_last:	Last used connection id sequence number
  * @conn_idr:		Map of connection device minor nummbers
  * @conn_hash:		Map of connection IDs
  * @ep_list:		Endpoints on this bus
@@ -54,9 +53,8 @@ struct kdbus_bus {
 	const char *name;
 	u64 id;
 	struct mutex lock;
-	u64 ep_id_next;
-	u64 conn_id_next;
-	u64 msg_id_next;
+	u64 ep_seq_last;
+	u64 conn_seq_last;
 	struct idr conn_idr;
 	DECLARE_HASHTABLE(conn_hash, 6);
 	struct list_head ep_list;
diff --git a/connection.c b/connection.c
index c426fb3..c0d280b 100644
--- a/connection.c
+++ b/connection.c
@@ -669,8 +669,13 @@ int kdbus_conn_kmsg_send(struct kdbus_ep *ep,
 	struct kdbus_conn *c;
 	int ret;
 
+	/* assign namespace-global message sequence number */
+	BUG_ON(kmsg->seq > 0);
+	kmsg->seq = atomic_inc_return(&ep->bus->ns->msg_seq_last);
+
 	/* non-kernel senders append credentials/metadata */
 	if (conn_src) {
+
 		ret = kdbus_meta_new(&kmsg->meta);
 		if (ret < 0)
 			return ret;
@@ -704,6 +709,7 @@ int kdbus_conn_kmsg_send(struct kdbus_ep *ep,
 			 */
 			if (conn_src)
 				kdbus_meta_append(kmsg->meta, conn_src,
+						  kmsg->seq,
 						  conn_dst->attach_flags);
 
 			kdbus_conn_queue_insert(conn_dst, kmsg);
@@ -787,7 +793,7 @@ int kdbus_conn_kmsg_send(struct kdbus_ep *ep,
 	}
 
 	if (conn_src) {
-		ret = kdbus_meta_append(kmsg->meta, conn_src,
+		ret = kdbus_meta_append(kmsg->meta, conn_src, kmsg->seq,
 					conn_dst->attach_flags);
 		if (ret < 0)
 			goto exit_unref;
@@ -1395,7 +1401,8 @@ int kdbus_cmd_conn_info(struct kdbus_conn *conn,
 		if (ret < 0)
 			goto exit;
 
-		ret = kdbus_meta_append(meta, owner_conn, KDBUS_ATTACH_NAMES);
+		ret = kdbus_meta_append(meta, owner_conn, 0,
+					KDBUS_ATTACH_NAMES);
 		if (ret < 0)
 			goto exit;
 
@@ -1551,7 +1558,7 @@ int kdbus_conn_new(struct kdbus_ep *ep,
 
 	/* link into bus; get new id for this connection */
 	mutex_lock(&bus->lock);
-	conn->id = bus->conn_id_next++;
+	conn->id = ++bus->conn_seq_last;
 	hash_add(bus->conn_hash, &conn->hentry, conn->id);
 	mutex_unlock(&bus->lock);
 
diff --git a/endpoint.c b/endpoint.c
index 75ccf3f..6bb6180 100644
--- a/endpoint.c
+++ b/endpoint.c
@@ -218,7 +218,7 @@ int kdbus_ep_new(struct kdbus_bus *bus, struct kdbus_ns *ns, const char *name,
 
 	/* link into bus  */
 	mutex_lock(&bus->lock);
-	e->id = bus->ep_id_next++;
+	e->id = ++bus->ep_seq_last;
 	e->bus = kdbus_bus_ref(bus);
 	list_add_tail(&e->bus_entry, &bus->ep_list);
 	mutex_unlock(&bus->lock);
diff --git a/handle.c b/handle.c
index 3a03a0e..1bfec19 100644
--- a/handle.c
+++ b/handle.c
@@ -131,7 +131,7 @@ static int kdbus_handle_open(struct inode *inode, struct file *file)
 	if (ret < 0)
 		goto exit_unlock;
 
-	ret = kdbus_meta_append(handle->meta, NULL,
+	ret = kdbus_meta_append(handle->meta, NULL, 0,
 				KDBUS_ATTACH_CREDS |
 				KDBUS_ATTACH_COMM |
 				KDBUS_ATTACH_EXE |
diff --git a/kdbus.h b/kdbus.h
index eb4525e..601d018 100644
--- a/kdbus.h
+++ b/kdbus.h
@@ -102,6 +102,7 @@ struct kdbus_audit {
 
 /**
  * struct kdbus_timestamp
+ * @seqnum:		Global per-namespace message sequence number
  * @monotonic_ns:	Monotonic timestamp, in nanoseconds
  * @realtime_ns:	Realtime timestamp, in nanoseconds
  *
@@ -109,6 +110,7 @@ struct kdbus_audit {
  *   KDBUS_ITEM_TIMESTAMP
  */
 struct kdbus_timestamp {
+	__u64 seqnum;
 	__u64 monotonic_ns;
 	__u64 realtime_ns;
 };
diff --git a/message.c b/message.c
index 0340b55..e9b8f52 100644
--- a/message.c
+++ b/message.c
@@ -24,6 +24,7 @@
 #include <linux/uaccess.h>
 
 #include "bus.h"
+#include "namespace.h"
 #include "connection.h"
 #include "endpoint.h"
 #include "match.h"
@@ -287,6 +288,10 @@ int kdbus_kmsg_new_from_user(struct kdbus_conn *conn,
 		goto exit_free;
 
 	/* patch-in the source of this message */
+	if (m->msg.src_id > 0 && m->msg.src_id != conn->id) {
+		ret = -EINVAL;
+		goto exit_free;
+	}
 	m->msg.src_id = conn->id;
 
 	*kmsg = m;
diff --git a/message.h b/message.h
index 55fa6cf..44ed106 100644
--- a/message.h
+++ b/message.h
@@ -14,10 +14,12 @@
 #define __KDBUS_MESSAGE_H
 
 #include "util.h"
+#include "namespace.h"
 #include "metadata.h"
 
 /**
  * struct kdbus_kmsg - internal message handling data
+ * @seq:		Namespace-global message sequence number
  * @notify_type:	Short-cut for faster lookup
  * @notify_old_id:	Short-cut for faster lookup
  * @notify_new_id:	Short-cut for faster lookup
@@ -36,6 +38,7 @@
  * @msg:		Message from or to userspace
  */
 struct kdbus_kmsg {
+	u64 seq;
 	u64 notify_type;
 	u64 notify_old_id;
 	u64 notify_new_id;
diff --git a/metadata.c b/metadata.c
index 364d9cd..3fe639e 100644
--- a/metadata.c
+++ b/metadata.c
@@ -25,6 +25,7 @@
 #include <linux/uaccess.h>
 
 #include "connection.h"
+#include "message.h"
 #include "metadata.h"
 #include "names.h"
 
@@ -148,7 +149,8 @@ static int kdbus_meta_append_str(struct kdbus_meta *meta, u64 type,
 	return kdbus_meta_append_data(meta, type, str, strlen(str) + 1);
 }
 
-static int kdbus_meta_append_timestamp(struct kdbus_meta *meta)
+static int kdbus_meta_append_timestamp(struct kdbus_meta *meta,
+				       u64 seq)
 {
 	struct kdbus_item *item;
 	u64 size = KDBUS_ITEM_SIZE(sizeof(struct kdbus_timestamp));
@@ -161,6 +163,9 @@ static int kdbus_meta_append_timestamp(struct kdbus_meta *meta)
 	item->type = KDBUS_ITEM_TIMESTAMP;
 	item->size = size;
 
+	if (seq > 0)
+		item->timestamp.seqnum = seq;
+
 	ktime_get_ts(&ts);
 	item->timestamp.monotonic_ns = timespec_to_ns(&ts);
 
@@ -381,6 +386,7 @@ static int kdbus_meta_append_seclabel(struct kdbus_meta *meta)
  * kdbus_meta_append() - collect metadata from current process
  * @meta:		Metadata object
  * @conn:		Current connection to read names from
+ * @seq:		Message sequence number
  * @which:		KDBUS_ATTACH_* flags which typ of data to attach
  *
  * Collect the data specified in flags and allocate or extend
@@ -390,6 +396,7 @@ static int kdbus_meta_append_seclabel(struct kdbus_meta *meta)
  */
 int kdbus_meta_append(struct kdbus_meta *meta,
 		      struct kdbus_conn *conn,
+		      u64 seq,
 		      u64 which)
 {
 	int ret = 0;
@@ -400,7 +407,7 @@ int kdbus_meta_append(struct kdbus_meta *meta,
 
 	if (which & KDBUS_ATTACH_TIMESTAMP &&
 	    !(meta->attached & KDBUS_ATTACH_TIMESTAMP)) {
-		ret = kdbus_meta_append_timestamp(meta);
+		ret = kdbus_meta_append_timestamp(meta, seq);
 		if (ret < 0)
 			goto exit;
 	}
diff --git a/metadata.h b/metadata.h
index f3fdc46..1ee510e 100644
--- a/metadata.h
+++ b/metadata.h
@@ -13,6 +13,8 @@
 #ifndef __KDBUS_METADATA_H
 #define __KDBUS_METADATA_H
 
+#include "message.h"
+
 /**
  * struct kdbus_meta - metadata buffer
  * @attached:		Flags for already attached data
@@ -39,6 +41,7 @@ int kdbus_meta_append_data(struct kdbus_meta *meta, u64 type,
 			   const void *buf, size_t len);
 int kdbus_meta_append(struct kdbus_meta *meta,
 		      struct kdbus_conn *conn,
+		      u64 seq,
 		      u64 which);
 void kdbus_meta_free(struct kdbus_meta *meta);
 #endif
diff --git a/names.c b/names.c
index 39327e2..7feabd5 100644
--- a/names.c
+++ b/names.c
@@ -88,7 +88,6 @@ int kdbus_name_registry_new(struct kdbus_name_registry **reg)
 
 	hash_init(r->entries_hash);
 	mutex_init(&r->entries_lock);
-	r->name_id_next = 1;
 
 	*reg = r;
 
@@ -478,7 +477,7 @@ int kdbus_name_acquire(struct kdbus_name_registry *reg,
 
 	e->flags = *flags;
 	INIT_LIST_HEAD(&e->queue_list);
-	e->name_id = reg->name_id_next++;
+	e->name_id = ++reg->name_seq_last;
 	hash_add(reg->entries_hash, &e->hentry, hash);
 	kdbus_name_entry_set_owner(e, conn);
 
diff --git a/names.h b/names.h
index 0dbb63d..447122a 100644
--- a/names.h
+++ b/names.h
@@ -19,12 +19,12 @@
  * struct kdbus_name_registry - names registered for a bus
  * @entries_hash:	Map of entries
  * @entries_lock:	Registry data lock
- * @name_id_next:	Next sequence number to assign to a name entry
+ * @name_seq_last:	Last used sequence number to assign to a name entry
  */
 struct kdbus_name_registry {
 	DECLARE_HASHTABLE(entries_hash, 6);
 	struct mutex		entries_lock;
-	u64 name_id_next;
+	u64 name_seq_last;
 };
 
 /**
diff --git a/namespace.c b/namespace.c
index 684fe43..c19816e 100644
--- a/namespace.c
+++ b/namespace.c
@@ -30,7 +30,7 @@
 static DEFINE_IDR(kdbus_ns_major_idr);
 
 /* next namespace id sequence number */
-static u64 kdbus_ns_id_next;
+static u64 kdbus_ns_seq_last;
 
 /* kdbus initial namespace */
 struct kdbus_ns *kdbus_ns_init;
@@ -216,6 +216,7 @@ int kdbus_ns_new(struct kdbus_ns *parent, const char *name, umode_t mode,
 	n->mode = mode;
 	idr_init(&n->idr);
 	mutex_init(&n->lock);
+	atomic_set(&n->msg_seq_last, 0);
 
 	mutex_lock(&kdbus_subsys_lock);
 
@@ -270,7 +271,7 @@ int kdbus_ns_new(struct kdbus_ns *parent, const char *name, umode_t mode,
 	}
 
 	/* get id for this namespace */
-	n->id = kdbus_ns_id_next++;
+	n->id = ++kdbus_ns_seq_last;
 
 	/* register control device for this namespace */
 	n->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
diff --git a/namespace.h b/namespace.h
index 93ff21b..e0730d6 100644
--- a/namespace.h
+++ b/namespace.h
@@ -13,6 +13,8 @@
 #ifndef __KDBUS_NS_H
 #define __KDBUS_NS_H
 
+#include <linux/idr.h>
+
 /**
  * struct kdbus_namespace - namespace for buses
  * @kref:		Reference counter
@@ -27,7 +29,8 @@
  * @idr:		Map of endpoint minors to buses
  * @dev:		Control device node, minor == 0
  * @lock:		Namespace data lock
- * @bus_id_next:	Next bus id sequence number
+ * @bus_seq_last:	Last used bus id sequence number
+ * @msg_seq_last:	Last used message id sequence number
  * @ns_entry:		Entry in parent namespace
  * @bus_list:		Buses in this namespace
  *
@@ -54,7 +57,8 @@ struct kdbus_ns {
 	struct idr idr;
 	struct device *dev;
 	struct mutex lock;
-	u64 bus_id_next;
+	u64 bus_seq_last;
+	atomic_t msg_seq_last;
 	struct list_head ns_entry;
 	struct list_head bus_list;
 };
diff --git a/test/kdbus-util.c b/test/kdbus-util.c
index 359a038..a8e2b80 100644
--- a/test/kdbus-util.c
+++ b/test/kdbus-util.c
@@ -350,8 +350,9 @@ void msg_dump(const struct conn *conn, const struct kdbus_msg *msg)
 		}
 
 		case KDBUS_ITEM_TIMESTAMP:
-			printf("  +%s (%llu bytes) realtime=%lluns monotonic=%lluns\n",
+			printf("  +%s (%llu bytes) seq=%llu realtime=%lluns monotonic=%lluns\n",
 			       enum_MSG(item->type), item->size,
+			       (unsigned long long)item->timestamp.seqnum,
 			       (unsigned long long)item->timestamp.realtime_ns,
 			       (unsigned long long)item->timestamp.monotonic_ns);
 			break;
-- 
2.34.1