[PATCH net] ipv4: Pass original device to ip_rcv_finish_core

[David Ahern]

From: David Ahern <dsah...@gmail.com>

ip_route_input_rcu expects the original ingress device (e.g., for
proper multicast handling). The skb->dev can be changed by l3mdev_ip_rcv,
so dev needs to be saved prior to calling it. This was the behavior prior
to the listify changes.

Fixes: 5fa12739a53d0 ("net: ipv4: listify ip_rcv_finish")
Cc: Edward Cree <ec...@solarflare.com>
Signed-off-by: David Ahern <dsah...@gmail.com>
---
 net/ipv4/ip_input.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 51d8efba6de2..1f4737b77067 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -307,11 +307,10 @@ static inline bool ip_rcv_options(struct sk_buff *skb)
 }
 
 static int ip_rcv_finish_core(struct net *net, struct sock *sk,
-                             struct sk_buff *skb)
+                             struct sk_buff *skb, struct net_device *dev)
 {
        const struct iphdr *iph = ip_hdr(skb);
        int (*edemux)(struct sk_buff *skb);
-       struct net_device *dev = skb->dev;
        struct rtable *rt;
        int err;
 
@@ -400,6 +399,7 @@ static int ip_rcv_finish_core(struct net *net, struct sock 
*sk,
 
 static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
+       struct net_device *dev = skb->dev;
        int ret;
 
        /* if ingress device is enslaved to an L3 master device pass the
@@ -409,7 +409,7 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, 
struct sk_buff *skb)
        if (!skb)
                return NET_RX_SUCCESS;
 
-       ret = ip_rcv_finish_core(net, sk, skb);
+       ret = ip_rcv_finish_core(net, sk, skb, dev);
        if (ret != NET_RX_DROP)
                ret = dst_input(skb);
        return ret;
@@ -545,6 +545,7 @@ static void ip_list_rcv_finish(struct net *net, struct sock 
*sk,
 
        INIT_LIST_HEAD(&sublist);
        list_for_each_entry_safe(skb, next, head, list) {
+               struct net_device *dev = skb->dev;
                struct dst_entry *dst;
 
                skb_list_del_init(skb);
@@ -554,7 +555,7 @@ static void ip_list_rcv_finish(struct net *net, struct sock 
*sk,
                skb = l3mdev_ip_rcv(skb);
                if (!skb)
                        continue;
-               if (ip_rcv_finish_core(net, sk, skb) == NET_RX_DROP)
+               if (ip_rcv_finish_core(net, sk, skb, dev) == NET_RX_DROP)
                        continue;
 
                dst = skb_dst(skb);
-- 
2.11.0