ipv4/ip_vti.c: VTI fix post-decryption forwarding

With the latest kernel there are two things that must be done post decryption
 so that the packet are forwarded.
 1. Remove the mark from the packet. This will cause the packet to not match
 the ipsec-policy again. However doing this causes the post-decryption check to
 fail also and the packet will get dropped. (cat /proc/net/xfrm_stat).
 2. Remove the sp association in the skbuff so that no policy check is done on
 the packet for VTI tunnels.

Due to #2 above we must now do a security-policy check in the vti rcv path
prior to resetting the mark in the skbuff.

Signed-off-by: Saurabh Mohan <saurabh.mohan@vyatta.com>
Reported-by: Ruben Herold <ruben@puettmann.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index 1831092f999fb32880f2d5e721c242236b000228..858fddf6482a645c46bf441c67d9ed323dc7d78f 100644 (file)
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -338,12 +338,17 @@ static int vti_rcv(struct sk_buff *skb)
        if (tunnel != NULL) {
                struct pcpu_tstats *tstats;
 
+               if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
+                       return -1;
+
                tstats = this_cpu_ptr(tunnel->dev->tstats);
                u64_stats_update_begin(&tstats->syncp);
                tstats->rx_packets++;
                tstats->rx_bytes += skb->len;
                u64_stats_update_end(&tstats->syncp);
 
+               skb->mark = 0;
+               secpath_reset(skb);
                skb->dev = tunnel->dev;
                return 1;
        }