[IPSEC]: IPv6 over IPv4 IPsec tunnel

This is the patch to support IPv6 over IPv4 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, 31 insertions, 15 deletions

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 8dffd4daae9c..59480e92177d 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -131,13 +131,11 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
         struct dst_entry *dst, *dst_prev;
         struct rt6_info *rt0 = (struct rt6_info*)(*dst_p);
         struct rt6_info *rt  = rt0;
-        struct in6_addr *remote = &fl->fl6_dst;
-        struct in6_addr *local  = &fl->fl6_src;
         struct flowi fl_tunnel = {
                 .nl_u = {
                         .ip6_u = {
-                                .saddr = *local,
-                                .daddr = *remote
+                                .saddr = fl->fl6_src,
+                                .daddr = fl->fl6_dst,
                         }
                 }
         };
@@ -153,7 +151,6 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
         for (i = 0; i < nx; i++) {
                 struct dst_entry *dst1 = dst_alloc(&xfrm6_dst_ops);
                 struct xfrm_dst *xdst;
-                int tunnel = 0;
 
                 if (unlikely(dst1 == NULL)) {
                         err = -ENOBUFS;
@@ -177,19 +174,27 @@ __xfrm6_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 = __xfrm6_bundle_addr_remote(xfrm[i], remote);
-                        local  = __xfrm6_bundle_addr_local(xfrm[i], local);
-                        tunnel = 1;
-                }
+
                 __xfrm6_bundle_len_inc(&header_len, &nfheader_len, xfrm[i]);
                 trailer_len += xfrm[i]->props.trailer_len;
 
-                if (tunnel) {
-                        ipv6_addr_copy(&fl_tunnel.fl6_dst, remote);
-                        ipv6_addr_copy(&fl_tunnel.fl6_src, local);
+                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;
+                        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;
+                        default:
+                                BUG_ON(1);
+                        }
+
                         err = xfrm_dst_lookup((struct xfrm_dst **) &rt,
-                                              &fl_tunnel, AF_INET6);
+                                              &fl_tunnel, encap_family);
                         if (err)
                                 goto error;
                 } else
@@ -208,6 +213,7 @@ __xfrm6_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;
 
                 dst_prev->xfrm = xfrm[i++];
                 dst_prev->dev = rt->u.dst.dev;
@@ -224,7 +230,17 @@ __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int
                 /* Copy neighbour for reachability confirmation */
                 dst_prev->neighbour     = neigh_clone(rt->u.dst.neighbour);
                 dst_prev->input         = rt->u.dst.input;
-                dst_prev->output        = xfrm6_output;
+                /* XXX: When IPv4 is implemented as module and can be unloaded,
+                 * we should manage reference to xfrm4_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);
                 /* Sheit... I remember I did this right. Apparently,
                  * it was magically lost, so this code needs audit */
                 x->u.rt6.rt6i_flags    = rt0->rt6i_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);