From c9e3e8b6958e02230079e6817862ea2968509866 Mon Sep 17 00:00:00 2001 From: David L Stevens Date: Tue, 21 Jun 2005 13:58:25 -0700 Subject: [IPV6]: multicast join and misc Here is a simplified version of the patch to fix a bug in IPv6 multicasting. It: 1) adds existence check & EADDRINUSE error for regular joins 2) adds an exception for EADDRINUSE in the source-specific multicast join (where a prior join is ok) 3) adds a missing/needed read_lock on sock_mc_list; would've raced with destroying the socket on interface down without 4) adds a "leave group" in the (INCLUDE, empty) source filter case. This frees unneeded socket buffer memory, but also prevents an inappropriate interaction among the 8 socket options that mess with this. Some would fail as if in the group when you aren't really. Item #4 had a locking bug in the last version of this patch; rather than removing the idev->lock read lock only, I've simplified it to remove all lock state in the path and treat it as a direct "leave group" call for the (INCLUDE,empty) case it covers. Tested on an MP machine. :-) Much thanks to HoerdtMickael who reported the original bug. Signed-off-by: David L Stevens Signed-off-by: David S. Miller --- net/ipv6/ipv6_sockglue.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/ipv6/ipv6_sockglue.c') diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index 279ab86be662..f3ef4c38d315 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -423,11 +423,12 @@ done: psin6 = (struct sockaddr_in6 *)&greqs.gsr_group; retv = ipv6_sock_mc_join(sk, greqs.gsr_interface, &psin6->sin6_addr); - if (retv) + /* prior join w/ different source is ok */ + if (retv && retv != -EADDRINUSE) break; omode = MCAST_INCLUDE; add = 1; - } else /*IP_DROP_SOURCE_MEMBERSHIP */ { + } else /* MCAST_LEAVE_SOURCE_GROUP */ { omode = MCAST_INCLUDE; add = 0; } -- cgit v1.2.3