[IPV4]: multicast API "join" issues
1) Changes IP_ADD_SOURCE_MEMBERSHIP and MCAST_JOIN_SOURCE_GROUP to ignore
EADDRINUSE errors on a "courtesy join" -- prior membership or not
is ok for these.
2) Adds "leave group" equivalence of (INCLUDE, empty) filters in the
delta-based API. Without this, mixing delta-based API calls that
end in an (INCLUDE, empty) filter would not allow a subsequent
regular IP_ADD_MEMBERSHIP. It also frees socket buffer memory that
isn't needed for both the multicast group record and source filter.
Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 111eb67..e21ebe7 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1724,6 +1724,7 @@
struct in_device *in_dev = NULL;
struct inet_sock *inet = inet_sk(sk);
struct ip_sf_socklist *psl;
+ int leavegroup = 0;
int i, j, rv;
if (!MULTICAST(addr))
@@ -1775,6 +1776,12 @@
if (rv) /* source not found */
goto done;
+ /* special case - (INCLUDE, empty) == LEAVE_GROUP */
+ if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
+ leavegroup = 1;
+ goto done;
+ }
+
/* update the interface filter */
ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
&mreqs->imr_sourceaddr, 1);
@@ -1831,6 +1838,8 @@
&mreqs->imr_sourceaddr, 1);
done:
rtnl_shunlock();
+ if (leavegroup)
+ return ip_mc_leave_group(sk, &imr);
return err;
}
