[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 fb9f69c..011136a 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);
 }