Re: [PATCH 1/1] igmp: fix ip_mc_clear_src to not reset ip_mc_list->sf{mode,count}
From: David Miller <davem@davemloft.net>
Date: 2011-05-16 18:08:03
Also in:
linux-kbuild, lkml
From: Veaceslav Falico <redacted> Date: Sun, 15 May 2011 18:59:45 +0200
ip_mc_clear_src resets the imc->sfcount and imc->sfmode, without taking into account the current number of sockets listening on that multicast struct, which can lead to bogus routes for local listeners. On NETDEV_DOWN/UP event, if there were 3 multicast listeners for that interface's address, the imc->sfcount[MCAST_EXCLUDE] will be reset to 1. And after that a listener socket destroys, multicast traffic will not be delivered to local listeners because __mkroute_output drops the local flag for the route (by checking ip_check_mc). Signed-off-by: Veaceslav Falico <redacted>
David, please take a look at this. Thanks.
quoted hunk ↗ jump to hunk
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 1fd3d9c..b14f371 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c@@ -1775,9 +1775,6 @@ static void ip_mc_clear_src(struct ip_mc_list *pmc) kfree(psf); } pmc->sources = NULL; - pmc->sfmode = MCAST_EXCLUDE; - pmc->sfcount[MCAST_INCLUDE] = 0; - pmc->sfcount[MCAST_EXCLUDE] = 1; }