[NETNS]: Add netns parameter to fib_select_default.

Currently fib_select_default calls fib_get_table() with the
init_net. Prepare it to provide a correct namespace to lookup default
route.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip_fib.h

@@ -213,7 +213,8 @@ extern const struct nla_policy rtm_ipv4_policy[];
 extern void		ip_fib_init(void);
 extern int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
 			       struct net_device *dev, __be32 *spec_dst, u32 *itag);
-extern void fib_select_default(const struct flowi *flp, struct fib_result *res);
+extern void fib_select_default(struct net *net, const struct flowi *flp,
+			       struct fib_result *res);
 
 /* Exported by fib_semantics.c */
 extern int ip_fib_check_default(__be32 gw, struct net_device *dev);

net/ipv4/fib_frontend.c

@@ -116,7 +116,8 @@ struct fib_table *fib_get_table(struct net *net, u32 id)
 }
 #endif /* CONFIG_IP_MULTIPLE_TABLES */
 
-void fib_select_default(const struct flowi *flp, struct fib_result *res)
+void fib_select_default(struct net *net,
+			const struct flowi *flp, struct fib_result *res)
 {
 	struct fib_table *tb;
 	int table = RT_TABLE_MAIN;
@@ -125,7 +126,7 @@ void fib_select_default(const struct flowi *flp, struct fib_result *res)
 		return;
 	table = res->r->table;
 #endif
-	tb = fib_get_table(&init_net, table);
+	tb = fib_get_table(net, table);
 	if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 		tb->tb_select_default(tb, flp, res);
 }

net/ipv4/route.c

@@ -2419,7 +2419,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
 	else
 #endif
 	if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
-		fib_select_default(&fl, &res);
+		fib_select_default(&init_net, &fl, &res);
 
 	if (!fl.fl4_src)
 		fl.fl4_src = FIB_RES_PREFSRC(res);