From 75fea73dce4ed7c1725f9f5c0adf5aecc8d0fcfd Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Mon, 28 Sep 2015 11:10:38 -0700 Subject: [PATCH] net: Swap ordering of tests in ip_route_input_mc This patch just swaps the ordering of one of the conditional tests in ip_route_input_mc. Specifically it swaps the testing for the source address to see if it is loopback, and the test to see if we allow a loopback source address. The reason for swapping these two tests is because it is much faster to test if an address is loopback than it is to dereference several pointers to get at the net structure to see if the use of loopback is allowed. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller --- net/ipv4/route.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 6bab84503cd9..43508c8d08e2 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1487,9 +1487,8 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, skb->protocol != htons(ETH_P_IP)) goto e_inval; - if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) - if (ipv4_is_loopback(saddr)) - goto e_inval; + if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev)) + goto e_inval; if (ipv4_is_zeronet(saddr)) { if (!ipv4_is_local_multicast(daddr)) -- 2.39.2