From a052517a8ff654f5226cf47008ebc4f7936b8f13 Mon Sep 17 00:00:00 2001 From: Hangbin Liu Date: Tue, 2 Aug 2016 18:02:57 +0800 Subject: net/multicast: should not send source list records when have filter mode change Based on RFC3376 5.1 and RFC3810 6.1 If the per-interface listening change that triggers the new report is a filter mode change, then the next [Robustness Variable] State Change Reports will include a Filter Mode Change Record. This applies even if any number of source list changes occur in that period. Old State New State State Change Record Sent --------- --------- ------------------------ INCLUDE (A) EXCLUDE (B) TO_EX (B) EXCLUDE (A) INCLUDE (B) TO_IN (B) So we should not send source-list change if there is a filter-mode change. Here are two scenarios: 1. Group deleted and filter mode is EXCLUDE, which means we need send a TO_IN { }. 2. Not group deleted, but has pcm->crcount, which means we need send a normal filter-mode-change. At the same time, if the type is ALLOW or BLOCK, and have psf->sf_crcount, we stop add records and decrease sf_crcount directly Reference: https://www.ietf.org/mail-archive/web/magma/current/msg01274.html Signed-off-by: Hangbin Liu Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/ipv6/mcast.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'net/ipv6/mcast.c') diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index d64ee7e83664..75c1fc54f188 100644 --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -1739,6 +1739,15 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc, continue; } + /* Based on RFC3810 6.1. Should not send source-list change + * records when there is a filter mode change. + */ + if (((gdeleted && pmc->mca_sfmode == MCAST_EXCLUDE) || + (!gdeleted && pmc->mca_crcount)) && + (type == MLD2_ALLOW_NEW_SOURCES || + type == MLD2_BLOCK_OLD_SOURCES) && psf->sf_crcount) + goto decrease_sf_crcount; + /* clear marks on query responses */ if (isquery) psf->sf_gsresp = 0; @@ -1766,6 +1775,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc, scount++; stotal++; if ((type == MLD2_ALLOW_NEW_SOURCES || type == MLD2_BLOCK_OLD_SOURCES) && psf->sf_crcount) { +decrease_sf_crcount: psf->sf_crcount--; if ((sdeleted || gdeleted) && psf->sf_crcount == 0) { if (psf_prev) -- cgit v1.2.3