Date: Tue, 1 Dec 2015 11:17:41 +0000 (UTC) From: "Andrey V. Elsukov" <ae@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r291578 - head/sys/netinet6 Message-ID: <201512011117.tB1BHftA014306@repo.freebsd.org>
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Author: ae Date: Tue Dec 1 11:17:41 2015 New Revision: 291578 URL: https://svnweb.freebsd.org/changeset/base/291578 Log: mld_v2_dispatch_general_query() is used by mld_fasttimo_vnet() to send a reply to the MLDv2 General Query. In case when router has a lot of multicast groups, the reply can take several packets due to MTU limitation. Also we have a limit MLD_MAX_RESPONSE_BURST == 4, that limits the number of packets we send in one shot. Then we recalculate the timer value and schedule the remaining packets for sending. The problem is that when we call mld_v2_dispatch_general_query() to send remaining packets, we queue new reply in the same mbuf queue. And when number of packets is bigger than MLD_MAX_RESPONSE_BURST, we get endless reply of MLDv2 reports. To fix this, add the check for remaining packets in the queue. PR: 204831 MFC after: 1 week Sponsored by: Yandex LLC Modified: head/sys/netinet6/mld6.c Modified: head/sys/netinet6/mld6.c ============================================================================== --- head/sys/netinet6/mld6.c Tue Dec 1 09:52:41 2015 (r291577) +++ head/sys/netinet6/mld6.c Tue Dec 1 11:17:41 2015 (r291578) @@ -2985,6 +2985,15 @@ mld_v2_dispatch_general_query(struct mld KASSERT(mli->mli_version == MLD_VERSION_2, ("%s: called when version %d", __func__, mli->mli_version)); + /* + * Check that there are some packets queued. If so, send them first. + * For large number of groups the reply to general query can take + * many packets, we should finish sending them before starting of + * queuing the new reply. + */ + if (mbufq_len(&mli->mli_gq) != 0) + goto send; + ifp = mli->mli_ifp; IF_ADDR_RLOCK(ifp); @@ -3020,6 +3029,7 @@ mld_v2_dispatch_general_query(struct mld } IF_ADDR_RUNLOCK(ifp); +send: mld_dispatch_queue(&mli->mli_gq, MLD_MAX_RESPONSE_BURST); /*
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