ipv6: wire up skb->encapsulation

When pushing a new header before current one call skb_reset_inner_headers
to record the position of the inner headers in the various ipv6 tunnel
protocols.

We later need this to correctly identify the addresses needed to send
back an error in the xfrm layer.

This change is safe, because skb->protocol is always checked before
dereferencing data from the inner protocol.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index ecd60733e5e24afdb28a52c95686fec28e2e4d73..90747f1973fe048abd6d8283235b2d80d038d691 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -724,6 +724,11 @@ static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
                ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
        }
 
+       if (likely(!skb->encapsulation)) {
+               skb_reset_inner_headers(skb);
+               skb->encapsulation = 1;
+       }
+
        skb_push(skb, gre_hlen);
        skb_reset_network_header(skb);
        skb_set_transport_header(skb, sizeof(*ipv6h));

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 1e55866cead7425eefdff36c1ddca1aab9504286..46ba243605a3d4de90b693b20b0f9ed58288234c 100644 (file)
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1027,6 +1027,12 @@ static int ip6_tnl_xmit2(struct sk_buff *skb,
                init_tel_txopt(&opt, encap_limit);
                ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
        }
+
+       if (likely(!skb->encapsulation)) {
+               skb_reset_inner_headers(skb);
+               skb->encapsulation = 1;
+       }
+
        skb_push(skb, sizeof(struct ipv6hdr));
        skb_reset_network_header(skb);
        ipv6h = ipv6_hdr(skb);

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index a3437a4cd07ecfdd28cbe47e0acd00e379ba9b19..fbfc5a83867ff5c03c2f7dec6ec6e93a0677171e 100644 (file)
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -888,6 +888,11 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
                ttl = iph6->hop_limit;
        tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 
+       if (likely(!skb->encapsulation)) {
+               skb_reset_inner_headers(skb);
+               skb->encapsulation = 1;
+       }
+
        err = iptunnel_xmit(dev_net(dev), rt, skb, fl4.saddr, fl4.daddr,
                            IPPROTO_IPV6, tos, ttl, df);
        iptunnel_xmit_stats(err, &dev->stats, dev->tstats);