[IPSEC]: Add encapsulation family.

Signed-off-by: NMiika Komu <miika@iki.fi>
Signed-off-by: NDiego Beltrami <Diego.Beltrami@hiit.fi>
Signed-off-by: NKazunori Miyazawa <miyazawa@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/xfrm.h

@@ -310,6 +310,8 @@ struct xfrm_tmpl
 /* Source address of tunnel. Ignored, if it is not a tunnel. */
 	xfrm_address_t		saddr;
 
+	unsigned short		encap_family;
+
 	__u32			reqid;
 
 /* Mode: transport, tunnel etc. */

net/xfrm/xfrm_policy.c

@@ -1211,6 +1211,7 @@ xfrm_tmpl_resolve_one(struct xfrm_policy *policy, struct flowi *fl,
 		if (tmpl->mode == XFRM_MODE_TUNNEL) {
 			remote = &tmpl->id.daddr;
 			local = &tmpl->saddr;
+			family = tmpl->encap_family;
 			if (xfrm_addr_any(local, family)) {
 				error = xfrm_get_saddr(&tmp, remote, family);
 				if (error)