ipv4: Make Netfilter's ip_route_me_harder() non-local address compatible

Netfilter's ip_route_me_harder() tries to re-route packets either
generated or re-routed by Netfilter. This patch changes
ip_route_me_harder() to handle packets from non-locally-bound sockets
with IP_TRANSPARENT set as local and to set the appropriate flowi
flags when re-doing the routing lookup.

Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index d533a89..d2a8f8b 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -340,6 +340,7 @@
 							.saddr = inet->saddr,
 							.tos = RT_CONN_FLAGS(sk) } },
 					    .proto = sk->sk_protocol,
+					    .flags = inet_sk_flowi_flags(sk),
 					    .uli_u = { .ports =
 						       { .sport = inet->sport,
 							 .dport = inet->dport } } };
@@ -1371,7 +1372,8 @@
 				    .uli_u = { .ports =
 					       { .sport = tcp_hdr(skb)->dest,
 						 .dport = tcp_hdr(skb)->source } },
-				    .proto = sk->sk_protocol };
+				    .proto = sk->sk_protocol,
+				    .flags = ip_reply_arg_flowi_flags(arg) };
 		security_skb_classify_flow(skb, &fl);
 		if (ip_route_output_key(sock_net(sk), &rt, &fl))
 			return;