From: David Ahern <dsahern@gmail.com>
Date: Wed, 16 Aug 2017 01:38:42 +0000 (-0700)
Subject: net: igmp: Use ingress interface rather than vrf device
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c7b725be84985532161bcb4fbecd056326998a77;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

net: igmp: Use ingress interface rather than vrf device

Anuradha reported that statically added groups for interfaces enslaved
to a VRF device were not persisting. The problem is that igmp queries
and reports need to use the data in the in_dev for the real ingress
device rather than the VRF device. Update igmp_rcv accordingly.

Fixes: e58e41596811 ("net: Enable support for VRF with ipv4 multicast")
Reported-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 498706b072fb..caf2f1101d02 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1007,10 +1007,18 @@ int igmp_rcv(struct sk_buff *skb)
 {
 	/* This basically follows the spec line by line -- see RFC1112 */
 	struct igmphdr *ih;
-	struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
+	struct net_device *dev = skb->dev;
+	struct in_device *in_dev;
 	int len = skb->len;
 	bool dropped = true;
 
+	if (netif_is_l3_master(dev)) {
+		dev = dev_get_by_index_rcu(dev_net(dev), IPCB(skb)->iif);
+		if (!dev)
+			goto drop;
+	}
+
+	in_dev = __in_dev_get_rcu(dev);
 	if (!in_dev)
 		goto drop;