Commit 75fea73d authored Sep 28, 2015 by Alexander Duyck Committed by David S. Miller Sep 29, 2015

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 <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 2094acbb

net/ipv4/route.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -1487,8 +1487,7 @@ 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))
		if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
		goto e_inval;

		if (ipv4_is_zeronet(saddr)) {

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