[NETNS]: Process FIB rule action in the context of the namespace.

Save namespace context on the fib rule at the rule creation time and
call routing lookup in the correct namespace.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/fib_rules.h

@@ -22,6 +22,7 @@ struct fib_rule
 	u32			target;
 	struct fib_rule *	ctarget;
 	struct rcu_head		rcu;
+	struct net *		fr_net;
 };
 
 struct fib_lookup_arg

net/core/fib_rules.c

@@ -29,6 +29,7 @@ int fib_default_rule_add(struct fib_rules_ops *ops,
 	r->pref = pref;
 	r->table = table;
 	r->flags = flags;
+	r->fr_net = ops->fro_net;
 
 	/* The lock is not required here, the list in unreacheable
 	 * at the moment this function is called */
@@ -242,6 +243,7 @@ static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 		err = -ENOMEM;
 		goto errout;
 	}
+	rule->fr_net = net;
 
 	if (tb[FRA_PRIORITY])
 		rule->pref = nla_get_u32(tb[FRA_PRIORITY]);

net/ipv4/fib_rules.c

@@ -91,7 +91,7 @@ static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
 		goto errout;
 	}
 
-	if ((tbl = fib_get_table(&init_net, rule->table)) == NULL)
+	if ((tbl = fib_get_table(rule->fr_net, rule->table)) == NULL)
 		goto errout;
 
 	err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result);