From 4d75313ce9b832efc4efb487f080b5ed72beae2c Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Tue, 25 Oct 2011 12:19:05 -0400 Subject: [PATCH] tipc: Prevent broadcast link stalling in dual LAN environments Ensure that sequence number information about incoming broadcast link messages is initialized only by the activation of the first link to a given cluster node. Previously, a race condition allowed reset and/or activation messages for a second link to re-initialize this sequence number information with obsolete values. This could trigger TIPC to request the retransmission of previously acknowledged broadcast link messages from that node, resulting in broadcast link processing becoming stalled if the node had already released one or more of those messages and was unable to perform the required retransmission. Thanks to Laser for identifying this problem and assisting in the development of this fix. Signed-off-by: Allan Stephens Signed-off-by: Paul Gortmaker --- net/tipc/link.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/tipc/link.c b/net/tipc/link.c index bee316ce387c..4ea6cad11746 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -2128,14 +2128,15 @@ static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf) } l_ptr->owner->bclink.supported = (max_pkt_info != 0); + /* Synchronize broadcast link info, if not done previously */ + + if (!tipc_node_is_up(l_ptr->owner)) + l_ptr->owner->bclink.last_in = msg_last_bcast(msg); + link_state_event(l_ptr, msg_type(msg)); l_ptr->peer_session = msg_session(msg); l_ptr->peer_bearer_id = msg_bearer_id(msg); - - /* Synchronize broadcast sequence numbers */ - if (!tipc_node_redundant_links(l_ptr->owner)) - l_ptr->owner->bclink.last_in = mod(msg_last_bcast(msg)); break; case STATE_MSG: -- 2.20.1