IPVS: netns to services part 1

Services hash tables got netns ptr a hash arg,
While Real Servers (rs) has been moved to ipvs struct.
Two new inline functions added to get net ptr from skb.

Since ip_vs is called from different contexts there is two
places to dig for the net ptr skb->dev or skb->sk
this is handled in skb_net() and skb_sknet()

Global functions, ip_vs_service_get() ip_vs_lookup_real_service()
etc have got  struct net *net as first param.
If possible get net ptr skb etc,
 - if not &init_net is used at this early stage of patching.

ip_vs_ctl.c  procfs not ready for netns yet.

*v3
 Comments by Julian
- __ip_vs_service_find and __ip_vs_svc_fwm_find are fast path,
  net_eq(svc->net, net) so the check is at the end now.
- net = skb_net(skb) in ip_vs_out moved after check for skb_dst.

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

include/net/netns/ip_vs.h

@@ -20,6 +20,14 @@ struct ctl_table_header;
 
 struct netns_ipvs {
 	int			gen;		/* Generation */
+	/*
+	 *	Hash table: for real service lookups
+	 */
+	#define IP_VS_RTAB_BITS 4
+	#define IP_VS_RTAB_SIZE (1 << IP_VS_RTAB_BITS)
+	#define IP_VS_RTAB_MASK (IP_VS_RTAB_SIZE - 1)
+
+	struct list_head	rs_table[IP_VS_RTAB_SIZE];
 };
 
 #endif /* IP_VS_H_ */