Commit d01ed324 authored by Antoine Tenart's avatar Antoine Tenart Committed by Pablo Neira Ayuso
Browse files

netfilter: br_netfilter: remove unused conditional and dead code 



The SKB_DROP_REASON_IP_INADDRERRORS drop reason is never returned from
any function, as such it cannot be returned from the ip_route_input call
tree. The 'reason != SKB_DROP_REASON_IP_INADDRERRORS' conditional is
thus always true.

Looking back at history, commit 50038bf3 ("net: ip: make
ip_route_input() return drop reasons") changed the ip_route_input
returned value check in br_nf_pre_routing_finish from -EHOSTUNREACH to
SKB_DROP_REASON_IP_INADDRERRORS. It turns out -EHOSTUNREACH could not be
returned either from the ip_route_input call tree and this since commit
251da413 ("ipv4: Cache ip_error() routes even when not
forwarding.").

Not a fix as this won't change the behavior. While at it use
kfree_skb_reason.

Signed-off-by: default avatarAntoine Tenart <atenart@kernel.org>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 8d738c18

net/bridge/br_netfilter_hooks.c

+1 −29
Original line number Diff line number Diff line
@@ -393,38 +393,10 @@ static int br_nf_pre_routing_finish(struct net *net, struct sock *sk, struct sk_ 
		reason = ip_route_input(skb, iph->daddr, iph->saddr,

					ip4h_dscp(iph), dev);

		if (reason) {

			struct in_device *in_dev = __in_dev_get_rcu(dev);



			/* If err equals -EHOSTUNREACH the error is due to a

			 * martian destination or due to the fact that

			 * forwarding is disabled. For most martian packets,

			 * ip_route_output_key() will fail. It won't fail for 2 types of

			 * martian destinations: loopback destinations and destination

			 * 0.0.0.0. In both cases the packet will be dropped because the

			 * destination is the loopback device and not the bridge. */

			if (reason != SKB_DROP_REASON_IP_INADDRERRORS || !in_dev ||

			    IN_DEV_FORWARD(in_dev))

				goto free_skb;



			rt = ip_route_output(net, iph->daddr, 0,

					     ip4h_dscp(iph), 0,

					     RT_SCOPE_UNIVERSE);

			if (!IS_ERR(rt)) {

				/* - Bridged-and-DNAT'ed traffic doesn't

				 *   require ip_forwarding. */

				if (rt->dst.dev == dev) {

					skb_dst_drop(skb);

					skb_dst_set(skb, &rt->dst);

					goto bridged_dnat;

				}

				ip_rt_put(rt);

			}

free_skb:

			kfree_skb(skb);

			kfree_skb_reason(skb, reason);

			return 0;

		} else {

			if (skb_dst(skb)->dev == dev) {

bridged_dnat:

				skb->dev = br_indev;

				nf_bridge_update_protocol(skb);

				nf_bridge_push_encap_header(skb);