netns xfrm: lookup in netns

Pass netns to xfrm_lookup()/__xfrm_lookup(). For that pass netns
to flow_cache_lookup() and resolver callback.

Take it from socket or netdevice. Stub DECnet to init_net.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index a5d750a..f259c96 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -260,7 +260,8 @@
 	if (final_p)
 		ipv6_addr_copy(&fl.fl6_dst, final_p);
 
-	if ((err = __xfrm_lookup(&dst, &fl, sk, XFRM_LOOKUP_WAIT)) < 0) {
+	err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
+	if (err < 0) {
 		if (err == -EREMOTE)
 			err = ip6_dst_blackhole(sk, &dst, &fl);
 		if (err < 0)
@@ -390,7 +391,7 @@
 				goto out;
 			}
 
-			if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
+			if ((err = xfrm_lookup(net, &dst, &fl, sk, 0)) < 0) {
 				sk->sk_err_soft = -err;
 				goto out;
 			}
@@ -492,7 +493,7 @@
 		goto done;
 	if (final_p)
 		ipv6_addr_copy(&fl.fl6_dst, final_p);
-	if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
+	if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
 		goto done;
 
 	skb = tcp_make_synack(sk, dst, req);
@@ -1018,7 +1019,7 @@
 	 * namespace
 	 */
 	if (!ip6_dst_lookup(ctl_sk, &buff->dst, &fl)) {
-		if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
+		if (xfrm_lookup(net, &buff->dst, &fl, NULL, 0) >= 0) {
 			ip6_xmit(ctl_sk, buff, &fl, NULL, 0);
 			TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
 			if (rst)
@@ -1316,7 +1317,7 @@
 		if (final_p)
 			ipv6_addr_copy(&fl.fl6_dst, final_p);
 
-		if ((xfrm_lookup(&dst, &fl, sk, 0)) < 0)
+		if ((xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
 			goto out;
 	}