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authorDavid Stevens <dlstevens@us.ibm.com>2010-09-30 14:29:40 +0000
committerDavid S. Miller <davem@davemloft.net>2010-10-03 21:58:47 -0700
commit5b7c84066733c5dfb0e4016d939757b38de189e4 (patch)
treefe7edf2d6327abfc1c4abdab5121e73cce52b693 /net
parent10ccff62bd3de7a64cf98f4c37ec0414b8affd4f (diff)
ipv4: correct IGMP behavior on v3 query during v2-compatibility mode
A recent patch to allow IGMPv2 responses to IGMPv3 queries bypasses length checks for valid query lengths, incorrectly resets the v2_seen timer, and does not support IGMPv1. The following patch responds with a v2 report as required by IGMPv2 while correcting the other problems introduced by the patch. Signed-Off-By: David L Stevens <dlstevens@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/igmp.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 1fdcacd36ce7..2a4bb76f2132 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -834,7 +834,7 @@ static void igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
int mark = 0;
- if (len == 8 || IGMP_V2_SEEN(in_dev)) {
+ if (len == 8) {
if (ih->code == 0) {
/* Alas, old v1 router presents here. */
@@ -856,6 +856,18 @@ static void igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
igmpv3_clear_delrec(in_dev);
} else if (len < 12) {
return; /* ignore bogus packet; freed by caller */
+ } else if (IGMP_V1_SEEN(in_dev)) {
+ /* This is a v3 query with v1 queriers present */
+ max_delay = IGMP_Query_Response_Interval;
+ group = 0;
+ } else if (IGMP_V2_SEEN(in_dev)) {
+ /* this is a v3 query with v2 queriers present;
+ * Interpretation of the max_delay code is problematic here.
+ * A real v2 host would use ih_code directly, while v3 has a
+ * different encoding. We use the v3 encoding as more likely
+ * to be intended in a v3 query.
+ */
+ max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
} else { /* v3 */
if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
return;

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