From: Joonwoo Park <joonwpark81@gmail.com>
Date: Fri, 18 Jan 2008 11:44:48 +0000 (-0800)
Subject: [IPV4] fib_hash: fix duplicated route issue
X-Git-Tag: v2.6.24~26^2~14
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bd566e7525b5986864e8d6eb5b67640abcd284a9;p=linux-2.6

[IPV4] fib_hash: fix duplicated route issue

http://bugzilla.kernel.org/show_bug.cgi?id=9493

The fib allows making identical routes with 'ip route replace'.
This patch makes the fib return -EEXIST if replacement would cause duplication.

Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/fib_hash.c b/net/ipv4/fib_hash.c
index 527a6e0af5..99071d79c5 100644
--- a/net/ipv4/fib_hash.c
+++ b/net/ipv4/fib_hash.c
@@ -444,6 +444,9 @@ static int fn_hash_insert(struct fib_table *tb, struct fib_config *cfg)
 			struct fib_info *fi_drop;
 			u8 state;
 
+			if (fi->fib_treeref > 1)
+				goto out;
+
 			write_lock_bh(&fib_hash_lock);
 			fi_drop = fa->fa_info;
 			fa->fa_info = fi;