[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>

6 files changed, 51 insertions, 3 deletions

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 14830edc2ac0..d8d85b13364d 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -101,7 +101,7 @@ struct rt6_info
         atomic_t                        rt6i_ref;
 
         /* more non-fragment space at head required */
-        unsigned short                  nfheader_len;
+        unsigned short                  rt6i_nfheader_len;
 
         u8                              rt6i_protocol;
 
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index d6dae5ae7abe..eea1c327c93e 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -242,6 +242,9 @@ struct xfrm_policy_afinfo {
                                                   struct flowi *fl,
                                                   int reverse);
         int                     (*get_tos)(struct flowi *fl);
+        int                     (*init_path)(struct xfrm_dst *path,
+                                             struct dst_entry *dst,
+                                             int nfheader_len);
         int                     (*fill_dst)(struct xfrm_dst *xdst,
                                             struct net_device *dev);
 };
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 5ccae3a463c2..656345f75e0d 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -84,6 +84,12 @@ static int xfrm4_get_tos(struct flowi *fl)
         return fl->fl4_tos;
 }
 
+static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
+                           int nfheader_len)
+{
+        return 0;
+}
+
 static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
 {
         struct rtable *rt = (struct rtable *)xdst->route;
@@ -251,6 +257,7 @@ static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
         .find_bundle =          __xfrm4_find_bundle,
         .decode_session =       _decode_session4,
         .get_tos =              xfrm4_get_tos,
+        .init_path =            xfrm4_init_path,
         .fill_dst =             xfrm4_fill_dst,
 };
 
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,
 };
 
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 8023a3c0dad5..521cb6e12561 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1266,6 +1266,23 @@ static inline struct xfrm_dst *xfrm_alloc_dst(int family)
         return xdst;
 }
 
+static inline int xfrm_init_path(struct xfrm_dst *path, struct dst_entry *dst,
+                                 int nfheader_len)
+{
+        struct xfrm_policy_afinfo *afinfo =
+                xfrm_policy_get_afinfo(dst->ops->family);
+        int err;
+
+        if (!afinfo)
+                return -EINVAL;
+
+        err = afinfo->init_path(path, dst, nfheader_len);
+
+        xfrm_policy_put_afinfo(afinfo);
+
+        return err;
+}
+
 static inline int xfrm_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
 {
         struct xfrm_policy_afinfo *afinfo =
@@ -1298,6 +1315,7 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
         int i = 0;
         int err;
         int header_len = 0;
+        int nfheader_len = 0;
         int trailer_len = 0;
         int tos;
         int family = policy->selector.family;
@@ -1352,6 +1370,8 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
                 dst_prev = dst1;
 
                 header_len += xfrm[i]->props.header_len;
+                if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
+                        nfheader_len += xfrm[i]->props.header_len;
                 trailer_len += xfrm[i]->props.trailer_len;
         }
 
@@ -1366,6 +1386,7 @@ static struct dst_entry *xfrm_bundle_create(struct xfrm_policy *policy,
         /* Copy neighbout for reachability confirmation */
         dst0->neighbour = neigh_clone(dst->neighbour);
 
+        xfrm_init_path((struct xfrm_dst *)dst0, dst, nfheader_len);
         xfrm_init_pmtu(dst_prev);
 
         for (dst_prev = dst0; dst_prev != dst; dst_prev = dst_prev->child) {