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| author | David Stevens <dlstevens@us.ibm.com> | 2010-09-30 14:29:40 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-10-03 21:58:47 -0700 |
| commit | 5b7c84066733c5dfb0e4016d939757b38de189e4 (patch) | |
| tree | fe7edf2d6327abfc1c4abdab5121e73cce52b693 | |
| parent | 10ccff62bd3de7a64cf98f4c37ec0414b8affd4f (diff) | |
| download | linux-3.10-5b7c84066733c5dfb0e4016d939757b38de189e4.tar.gz linux-3.10-5b7c84066733c5dfb0e4016d939757b38de189e4.tar.bz2 linux-3.10-5b7c84066733c5dfb0e4016d939757b38de189e4.zip | |
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>
| -rw-r--r-- | net/ipv4/igmp.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 1fdcacd36ce..2a4bb76f213 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; |