tipc: Ensure broadcast link spinlock is held when updating node map

Fixes oversight that allowed broadcast link node map to be updated without
first taking the broadcast link spinlock that protects the map. As part
of this fix the node map has been incorporated into the broadcast link
structure to make the need for such protection more evident.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

1 files changed, 18 insertions, 6 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 738cb642d31b..5ca8fdda63ca 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -87,6 +87,7 @@ struct bcbearer {
  * struct bclink - link used for broadcast messages
  * @link: (non-standard) broadcast link structure
  * @node: (non-standard) node structure representing b'cast link's peer node
+ * @bcast_nodes: map of broadcast-capable nodes
  * @retransmit_to: node that most recently requested a retransmit
  *
  * Handles sequence numbering, fragmentation, bundling, etc.
@@ -95,6 +96,7 @@ struct bcbearer {
 struct bclink {
 	struct link link;
 	struct tipc_node node;
+	struct tipc_node_map bcast_nodes;
 	struct tipc_node *retransmit_to;
 };
 
@@ -107,9 +109,6 @@ static struct link *bcl = &bcast_link.link;
 
 static DEFINE_SPINLOCK(bc_lock);
 
-/* broadcast-capable node map */
-struct tipc_node_map tipc_bcast_nmap;
-
 const char tipc_bclink_name[] = "broadcast-link";
 
 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
@@ -136,6 +135,19 @@ static void bcbuf_decr_acks(struct sk_buff *buf)
 	bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
 }
 
+void tipc_bclink_add_node(u32 addr)
+{
+	spin_lock_bh(&bc_lock);
+	tipc_nmap_add(&bclink->bcast_nodes, addr);
+	spin_unlock_bh(&bc_lock);
+}
+
+void tipc_bclink_remove_node(u32 addr)
+{
+	spin_lock_bh(&bc_lock);
+	tipc_nmap_remove(&bclink->bcast_nodes, addr);
+	spin_unlock_bh(&bc_lock);
+}
 
 static void bclink_set_last_sent(void)
 {
@@ -575,13 +587,13 @@ static int tipc_bcbearer_send(struct sk_buff *buf,
 	if (likely(!msg_non_seq(buf_msg(buf)))) {
 		struct tipc_msg *msg;
 
-		bcbuf_set_acks(buf, tipc_bcast_nmap.count);
+		bcbuf_set_acks(buf, bclink->bcast_nodes.count);
 		msg = buf_msg(buf);
 		msg_set_non_seq(msg, 1);
 		msg_set_mc_netid(msg, tipc_net_id);
 		bcl->stats.sent_info++;
 
-		if (WARN_ON(!tipc_bcast_nmap.count)) {
+		if (WARN_ON(!bclink->bcast_nodes.count)) {
 			dump_stack();
 			return 0;
 		}
@@ -589,7 +601,7 @@ static int tipc_bcbearer_send(struct sk_buff *buf,
 
 	/* Send buffer over bearers until all targets reached */
 
-	bcbearer->remains = tipc_bcast_nmap;
+	bcbearer->remains = bclink->bcast_nodes;
 
 	for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
 		struct tipc_bearer *p = bcbearer->bpairs[bp_index].primary;