[NETFILTER]: Fix xfrm lookup in ip_route_me_harder/ip6_route_me_harder

ip_route_me_harder doesn't use the port numbers of the xfrm lookup and
uses ip_route_input for non-local addresses which doesn't do a xfrm
lookup, ip6_route_me_harder doesn't do a xfrm lookup at all.

Use xfrm_decode_session and do the lookup manually, make sure both
only do the lookup if the packet hasn't been transformed already.

Makeing sure the lookup only happens once needs a new field in the
IP6CB, which exceeds the size of skb->cb. The size of skb->cb is
increased to 48b. Apparently the IPv6 mobile extensions need some
more room anyway.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 65c3a91ed85e..de16e944777f 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -832,7 +832,7 @@ static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
         skb->h.raw = skb->nh.raw;
         skb->nh.raw = skb_push(skb, gre_hlen);
         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
-        IPCB(skb)->flags &= ~IPSKB_XFRM_TUNNEL_SIZE;
+        IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE|IPSKB_XFRM_TRANSFORMED);
         dst_release(skb->dst);
         skb->dst = &rt->u.dst;