[XFRM]: Fix wildcard as tunnel source

Hashing SAs by source address breaks templates with wildcards as tunnel
source since the source address used for hashing/lookup is still 0/0.
Move source address lookup to xfrm_tmpl_resolve_one() so we can use the
real address in the lookup.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 20 insertions, 15 deletions

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 4795985..eabcd27 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -21,6 +21,25 @@ static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
 	return __ip_route_output_key((struct rtable**)dst, fl);
 }
 
+static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
+{
+	struct rtable *rt;
+	struct flowi fl_tunnel = {
+		.nl_u = {
+			.ip4_u = {
+				.daddr = daddr->a4,
+			},
+		},
+	};
+
+	if (!xfrm4_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) {
+		saddr->a4 = rt->rt_src;
+		dst_release(&rt->u.dst);
+		return 0;
+	}
+	return -EHOSTUNREACH;
+}
+
 static struct dst_entry *
 __xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
 {
@@ -298,6 +317,7 @@ static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
 	.family = 		AF_INET,
 	.dst_ops =		&xfrm4_dst_ops,
 	.dst_lookup =		xfrm4_dst_lookup,
+	.get_saddr =		xfrm4_get_saddr,
 	.find_bundle = 		__xfrm4_find_bundle,
 	.bundle_create =	__xfrm4_bundle_create,
 	.decode_session =	_decode_session4,
diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c
index 6a2a4ab..fe20344 100644
--- a/net/ipv4/xfrm4_state.c
+++ b/net/ipv4/xfrm4_state.c
@@ -42,21 +42,6 @@ __xfrm4_init_tempsel(struct xfrm_state *x, struct flowi *fl,
 	x->props.saddr = tmpl->saddr;
 	if (x->props.saddr.a4 == 0)
 		x->props.saddr.a4 = saddr->a4;
-	if (tmpl->mode == XFRM_MODE_TUNNEL && x->props.saddr.a4 == 0) {
-		struct rtable *rt;
-	        struct flowi fl_tunnel = {
-        	        .nl_u = {
-        			.ip4_u = {
-					.daddr = x->id.daddr.a4,
-				}
-			}
-		};
-		if (!xfrm_dst_lookup((struct xfrm_dst **)&rt,
-		                     &fl_tunnel, AF_INET)) {
-			x->props.saddr.a4 = rt->rt_src;
-			dst_release(&rt->u.dst);
-		}
-	}
 	x->props.mode = tmpl->mode;
 	x->props.reqid = tmpl->reqid;
 	x->props.family = AF_INET;