ipvs: do not schedule conns from real servers

 	This patch is needed to avoid scheduling of
packets from local real server when we add ip_vs_in
in LOCAL_OUT hook to support local client.

 	Currently, when ip_vs_in can not find existing
connection it tries to create new one by calling ip_vs_schedule.

 	The default indication from ip_vs_schedule was if
connection was scheduled to real server. If real server is
not available we try to use the bypass forwarding method
or to send ICMP error. But in some cases we do not want to use
the bypass feature. So, add flag 'ignored' to indicate if
the scheduler ignores this packet.

 	Make sure we do not create new connections from replies.
We can hit this problem for persistent services and local real
server when ip_vs_in is added to LOCAL_OUT hook to handle
local clients.

 	Also, make sure ip_vs_schedule ignores SYN packets
for Active FTP DATA from local real server. The FTP DATA
connection should be created on SYN+ACK from client to assign
correct connection daddr.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/netfilter/ipvs/ip_vs_proto_udp.c b/net/netfilter/ipvs/ip_vs_proto_udp.c
index 9c558c4..5d21f08 100644
--- a/net/netfilter/ipvs/ip_vs_proto_udp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_udp.c
@@ -46,6 +46,8 @@ udp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
 	svc = ip_vs_service_get(af, skb->mark, iph.protocol,
 				&iph.daddr, uh->dest);
 	if (svc) {
+		int ignored;
+
 		if (ip_vs_todrop()) {
 			/*
 			 * It seems that we are very loaded.
@@ -60,8 +62,8 @@ udp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
 		 * Let the virtual server select a real server for the
 		 * incoming connection, and create a connection entry.
 		 */
-		*cpp = ip_vs_schedule(svc, skb);
-		if (!*cpp) {
+		*cpp = ip_vs_schedule(svc, skb, pp, &ignored);
+		if (!*cpp && !ignored) {
 			*verdict = ip_vs_leave(svc, skb, pp);
 			return 0;
 		}