[PATCH net] ipv6: only apply anti-spoofing checks to not-pointopoint tunnels

[PATCH net] ipv6: only apply anti-spoofing checks to not-pointopoint tunnels

[Hannes Frederic Sowa]

Because of commit 218774dc341f219bfcf940304a081b121a0e8099 ("ipv6: add
anti-spoofing checks for 6to4 and 6rd") the sit driver dropped packets
for 2002::/16 destinations and sources even when configured to work as a
tunnel with fixed endpoint. We may only apply the 6rd/6to4 anti-spoofing
checks if the device is not in pointopoint mode.

This was an oversight from me in the above commit, sorry.  Thanks to
Roman Mamedov for reporting this!

Reported-by: Roman Mamedov <rm@romanrm.ru>
Cc: David Miller <davem@davemloft.net>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
David, could you please (after review) put this in the stable queue for
a potential v3.9.9 release? It is only applicable for v3.9. Thanks!

 net/ipv6/sit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 3353634..60df36d 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -589,7 +589,7 @@ static int ipip6_rcv(struct sk_buff *skb)
 				tunnel->dev->stats.rx_errors++;
 				goto out;
 			}
-		} else {
+		} else if (!(tunnel->dev->flags&IFF_POINTOPOINT)) {
 			if (is_spoofed_6rd(tunnel, iph->saddr,
 					   &ipv6_hdr(skb)->saddr) ||
 			    is_spoofed_6rd(tunnel, iph->daddr,
-- 
1.8.1.4

Re: [PATCH net] ipv6: only apply anti-spoofing checks to not-pointopoint tunnels

[David Miller]

From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Date: Thu, 27 Jun 2013 22:46:04 +0200

> Because of commit 218774dc341f219bfcf940304a081b121a0e8099 ("ipv6: add
> anti-spoofing checks for 6to4 and 6rd") the sit driver dropped packets
> for 2002::/16 destinations and sources even when configured to work as a
> tunnel with fixed endpoint. We may only apply the 6rd/6to4 anti-spoofing
> checks if the device is not in pointopoint mode.
> 
> This was an oversight from me in the above commit, sorry.  Thanks to
> Roman Mamedov for reporting this!
> 
> Reported-by: Roman Mamedov <rm@romanrm.ru>
> Cc: David Miller <davem@davemloft.net>
> Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

Applied and queued up for -stable.