Re: [PATCH] ipip: Fix bug added to ipip_tunnel_xmit().

[David Miller <davem@davemloft.net>]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 25 Jan 2012 00:21:35 +0100

> Le mardi 24 janvier 2012 à 18:18 -0500, David Miller a écrit :
>> We can remove the rt_gateway == 0 check but we shouldn't
>> remove the 'dst' initialization too.
>> 
>> Noticed by Eric Dumazet.
>> 
>> Signed-off-by: David S. Miller <davem@davemloft.net>
>> ---
>>  net/ipv4/ipip.c |    1 +
>>  1 files changed, 1 insertions(+), 0 deletions(-)
>> 
>> diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
>> index 87c63b6..f84ebff 100644
>> --- a/net/ipv4/ipip.c
>> +++ b/net/ipv4/ipip.c
>> @@ -454,6 +454,7 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
>>  			dev->stats.tx_fifo_errors++;
>>  			goto tx_error;
>>  		}
>> +		dst = rt->rt_gateway;
>>  	}
>>  
>>  	rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
> 
> 
> Well, a similar fix is needed for net/ipv4/ip_gre.c :)

Indeed:

--------------------
ip_gre: Fix bug added to ipgre_tunnel_xmit().

We can remove the rt_gateway == 0 check but we shouldn't
remove the 'dst' initialization too.

Noticed by Eric Dumazet.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/ip_gre.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index fc21335..05f7419 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -724,8 +724,10 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
 			goto tx_error;
 		}
 
-		if (skb->protocol == htons(ETH_P_IP))
+		if (skb->protocol == htons(ETH_P_IP)) {
 			rt = skb_rtable(skb);
+			dst = rt->rt_gateway;
+		}
 #if IS_ENABLED(CONFIG_IPV6)
 		else if (skb->protocol == htons(ETH_P_IPV6)) {
 			struct neighbour *neigh = dst_get_neighbour_noref(skb_dst(skb));
-- 
1.7.7.6