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 <liuhang...@gmail.com>
Acked-by: Hannes Frederic Sowa <han...@stressinduktion.org>
---
net/ipv4/igmp.c | 10 ++++++++++
net/ipv6/mcast.c | 10 ++++++++++
2 files changed, 20 insertions(+)
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 9b4ca87..606cc3e 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -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)
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index d64ee7e..75c1fc5 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)
--
2.5.5
