From: Edward Chron <echron@arista.com>
Date: Thu, 31 Jan 2019 23:00:40 +0000 (-0800)
Subject: ipv4/igmp: Don't drop IGMP pkt with zeros src addr
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=1d2f4ebbbeb1ec055dcd3cf3dba833cfd0a84f3a;p=linux.git

ipv4/igmp: Don't drop IGMP pkt with zeros src addr

Don't drop IGMP packets with a source address of all zeros which are
IGMP proxy reports. This is documented in Section 2.1.1 IGMP
Forwarding Rules of RFC 4541 IGMP and MLD Snooping Switches
Considerations.

Signed-off-by: Edward Chron <echron@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 99be68b15da07..16259ea9df549 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1608,7 +1608,8 @@ int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		return -EINVAL;
 
 	if (ipv4_is_zeronet(saddr)) {
-		if (!ipv4_is_local_multicast(daddr))
+		if (!ipv4_is_local_multicast(daddr) &&
+		    ip_hdr(skb)->protocol != IPPROTO_IGMP)
 			return -EINVAL;
 	} else {
 		err = fib_validate_source(skb, saddr, 0, tos, 0, dev,