Commit a052517a authored by Hangbin Liu's avatar Hangbin Liu Committed by David S. Miller
Browse files

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: default avatarHangbin Liu <liuhangbin@gmail.com>
Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 013ad40d

net/ipv4/igmp.c

+10 −0
Original line number Diff line number Diff line
@@ -472,6 +472,15 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, 
			continue;

		}



		/* Based on RFC3376 5.1. Should not send source-list change

		 * records when there is a filter mode change.

		 */

		if (((gdeleted && pmc->sfmode == MCAST_EXCLUDE) ||

		     (!gdeleted && pmc->crcount)) &&

		    (type == IGMPV3_ALLOW_NEW_SOURCES ||

		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount)

			goto decrease_sf_crcount;



		/* clear marks on query responses */

		if (isquery)

			psf->sf_gsresp = 0;
@@ -499,6 +508,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc, 
		scount++; stotal++;

		if ((type == IGMPV3_ALLOW_NEW_SOURCES ||

		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {

decrease_sf_crcount:

			psf->sf_crcount--;

			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {

				if (psf_prev)

net/ipv6/mcast.c

+10 −0
Original line number Diff line number Diff line
@@ -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)

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