commit bd566e7525b5986864e8d6eb5b67640abcd284a9
author Joonwoo Park <joonwpark81@gmail.com> Fri Jan 18 03:44:48 2008 -0800
committer David S. Miller <davem@davemloft.net> Sun Jan 20 20:31:37 2008 -0800
tree ef53396f419171eb1db49803d84c0c8b50af0ca8
parent b3652b2dc5ec6ccd946ae9136b30c6babb81305a

[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>

net/ipv4/fib_hash.c

diff --git a/net/ipv4/fib_hash.c b/net/ipv4/fib_hash.c
index 527a6e0..99071d7 100644
--- a/net/ipv4/fib_hash.c
+++ b/net/ipv4/fib_hash.c
@@ -444,6 +444,9 @@
 			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;