[IPSEC]: IPv4 over IPv6 IPsec tunnel

This is the patch to support IPv4 over IPv6 IPsec.

Signed-off-by: Miika Komu <miika@iki.fi>
Signed-off-by: Diego Beltrami <Diego.Beltrami@hiit.fi>
Signed-off-by: Kazunori Miyazawa <miyazawa@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 17 deletions

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index fb9f69c616f5..011136a95809 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -72,13 +72,11 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
         struct dst_entry *dst, *dst_prev;
         struct rtable *rt0 = (struct rtable*)(*dst_p);
         struct rtable *rt = rt0;
-        __be32 remote = fl->fl4_dst;
-        __be32 local  = fl->fl4_src;
         struct flowi fl_tunnel = {
                 .nl_u = {
                         .ip4_u = {
-                                .saddr = local,
-                                .daddr = remote,
+                                .saddr = fl->fl4_src,
+                                .daddr = fl->fl4_dst,
                                 .tos = fl->fl4_tos
                         }
                 }
@@ -94,7 +92,6 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
         for (i = 0; i < nx; i++) {
                 struct dst_entry *dst1 = dst_alloc(&xfrm4_dst_ops);
                 struct xfrm_dst *xdst;
-                int tunnel = 0;
 
                 if (unlikely(dst1 == NULL)) {
                         err = -ENOBUFS;
@@ -116,19 +113,28 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
 
                 dst1->next = dst_prev;
                 dst_prev = dst1;
-                if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
-                        remote = xfrm[i]->id.daddr.a4;
-                        local  = xfrm[i]->props.saddr.a4;
-                        tunnel = 1;
-                }
+
                 header_len += xfrm[i]->props.header_len;
                 trailer_len += xfrm[i]->props.trailer_len;
 
-                if (tunnel) {
-                        fl_tunnel.fl4_src = local;
-                        fl_tunnel.fl4_dst = remote;
+                if (xfrm[i]->props.mode == XFRM_MODE_TUNNEL) {
+                        unsigned short encap_family = xfrm[i]->props.family;
+                        switch(encap_family) {
+                        case AF_INET:
+                                fl_tunnel.fl4_dst = xfrm[i]->id.daddr.a4;
+                                fl_tunnel.fl4_src = xfrm[i]->props.saddr.a4;
+                                break;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+                        case AF_INET6:
+                                ipv6_addr_copy(&fl_tunnel.fl6_dst, (struct in6_addr*)&xfrm[i]->id.daddr.a6);
+                                ipv6_addr_copy(&fl_tunnel.fl6_src, (struct in6_addr*)&xfrm[i]->props.saddr.a6);
+                                break;
+#endif
+                        default:
+                                BUG_ON(1);
+                        }
                         err = xfrm_dst_lookup((struct xfrm_dst **)&rt,
-                                              &fl_tunnel, AF_INET);
+                                              &fl_tunnel, encap_family);
                         if (err)
                                 goto error;
                 } else
@@ -145,6 +151,7 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
         i = 0;
         for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
                 struct xfrm_dst *x = (struct xfrm_dst*)dst_prev;
+                struct xfrm_state_afinfo *afinfo;
                 x->u.rt.fl = *fl;
 
                 dst_prev->xfrm = xfrm[i++];
@@ -162,8 +169,17 @@ __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
                 /* Copy neighbout for reachability confirmation */
                 dst_prev->neighbour     = neigh_clone(rt->u.dst.neighbour);
                 dst_prev->input         = rt->u.dst.input;
-                dst_prev->output        = xfrm4_output;
-                if (rt->peer)
+                /* XXX: When IPv6 module can be unloaded, we should manage reference
+                 * to xfrm6_output in afinfo->output. Miyazawa
+                 * */
+                afinfo = xfrm_state_get_afinfo(dst_prev->xfrm->props.family);
+                if (!afinfo) {
+                        dst = *dst_p;
+                        goto error;
+                }
+                dst_prev->output = afinfo->output;
+                xfrm_state_put_afinfo(afinfo);
+                if (dst_prev->xfrm->props.family == AF_INET && rt->peer)
                         atomic_inc(&rt->peer->refcnt);
                 x->u.rt.peer = rt->peer;
                 /* Sheit... I remember I did this right. Apparently,
@@ -274,7 +290,7 @@ static void xfrm4_dst_destroy(struct dst_entry *dst)
 
         if (likely(xdst->u.rt.idev))
                 in_dev_put(xdst->u.rt.idev);
-        if (likely(xdst->u.rt.peer))
+        if (dst->xfrm->props.family == AF_INET && likely(xdst->u.rt.peer))
                 inet_putpeer(xdst->u.rt.peer);
         xfrm_dst_destroy(xdst);
 }