[XFRM] IPv6: Fix dst/routing check at transformation.

IPv6 specific thing is wrongly removed from transformation at net-2.6.25.
This patch recovers it with current design.

o Update "path" of xfrm_dst since IPv6 transformation should
  care about routing changes. It is required by MIPv6 and
  off-link destined IPsec.
o Rename nfheader_len which is for non-fragment transformation used by
  MIPv6 to rt6i_nfheader_len as IPv6 name space.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 19 insertions, 2 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index d54da616e3af..4686646058d3 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1126,7 +1126,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
                 sk->sk_sndmsg_page = NULL;
                 sk->sk_sndmsg_off = 0;
                 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0) -
-                            rt->nfheader_len;
+                            rt->rt6i_nfheader_len;
                 length += exthdrlen;
                 transhdrlen += exthdrlen;
         } else {
@@ -1141,7 +1141,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 
         hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
 
-        fragheaderlen = sizeof(struct ipv6hdr) + rt->nfheader_len +
+        fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
                         (opt ? opt->opt_nflen : 0);
         maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
 
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index d26b7dc3f33b..cf373b46a1ba 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -98,6 +98,20 @@ static int xfrm6_get_tos(struct flowi *fl)
         return 0;
 }
 
+static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst,
+                           int nfheader_len)
+{
+        if (dst->ops->family == AF_INET6) {
+                struct rt6_info *rt = (struct rt6_info*)dst;
+                if (rt->rt6i_node)
+                        path->path_cookie = rt->rt6i_node->fn_sernum;
+        }
+
+        path->u.rt6.rt6i_nfheader_len = nfheader_len;
+
+        return 0;
+}
+
 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
 {
         struct rt6_info *rt = (struct rt6_info*)xdst->route;
@@ -115,6 +129,8 @@ static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
                                                    RTF_LOCAL);
         xdst->u.rt6.rt6i_metric = rt->rt6i_metric;
         xdst->u.rt6.rt6i_node = rt->rt6i_node;
+        if (rt->rt6i_node)
+                xdst->route_cookie = rt->rt6i_node->fn_sernum;
         xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
         xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
         xdst->u.rt6.rt6i_src = rt->rt6i_src;
@@ -266,6 +282,7 @@ static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
         .find_bundle =          __xfrm6_find_bundle,
         .decode_session =       _decode_session6,
         .get_tos =              xfrm6_get_tos,
+        .init_path =            xfrm6_init_path,
         .fill_dst =             xfrm6_fill_dst,
 };