[NETNS]: Process /proc/net/rt_cache inside a namespace.

Show routing cache for a particular namespace only.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/route.c

@@ -273,6 +273,7 @@ static unsigned int rt_hash_code(u32 daddr, u32 saddr)
 
 #ifdef CONFIG_PROC_FS
 struct rt_cache_iter_state {
+	struct seq_net_private p;
 	int bucket;
 	int genid;
 };
@@ -285,7 +286,8 @@ static struct rtable *rt_cache_get_first(struct rt_cache_iter_state *st)
 		rcu_read_lock_bh();
 		r = rcu_dereference(rt_hash_table[st->bucket].chain);
 		while (r) {
-			if (r->rt_genid == st->genid)
+			if (r->u.dst.dev->nd_net == st->p.net &&
+			    r->rt_genid == st->genid)
 				return r;
 			r = rcu_dereference(r->u.dst.rt_next);
 		}
@@ -312,6 +314,8 @@ static struct rtable *rt_cache_get_next(struct rt_cache_iter_state *st,
 					struct rtable *r)
 {
 	while ((r = __rt_cache_get_next(st, r)) != NULL) {
+		if (r->u.dst.dev->nd_net != st->p.net)
+			continue;
 		if (r->rt_genid == st->genid)
 			break;
 	}
@@ -398,7 +402,7 @@ static const struct seq_operations rt_cache_seq_ops = {
 
 static int rt_cache_seq_open(struct inode *inode, struct file *file)
 {
-	return seq_open_private(file, &rt_cache_seq_ops,
+	return seq_open_net(inode, file, &rt_cache_seq_ops,
 			sizeof(struct rt_cache_iter_state));
 }
 
@@ -407,7 +411,7 @@ static const struct file_operations rt_cache_seq_fops = {
 	.open	 = rt_cache_seq_open,
 	.read	 = seq_read,
 	.llseek	 = seq_lseek,
-	.release = seq_release_private,
+	.release = seq_release_net,
 };