From b46ffb854554ff939701bdd492b81558da5706fc Mon Sep 17 00:00:00 2001 From: Changli Gao Date: Tue, 21 Sep 2010 21:17:31 +0000 Subject: [PATCH] netfilter: fix ipt_REJECT TCP RST routing for indev == outdev ip_route_me_harder can't create the route cache when the outdev is the same with the indev for the skbs whichout a valid protocol set. __mkroute_input functions has this check: 1998 if (skb->protocol != htons(ETH_P_IP)) { 1999 /* Not IP (i.e. ARP). Do not create route, if it is 2000 * invalid for proxy arp. DNAT routes are always valid. 2001 * 2002 * Proxy arp feature have been extended to allow, ARP 2003 * replies back to the same interface, to support 2004 * Private VLAN switch technologies. See arp.c. 2005 */ 2006 if (out_dev == in_dev && 2007 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) { 2008 err = -EINVAL; 2009 goto cleanup; 2010 } 2011 } This patch gives the new skb a valid protocol to bypass this check. In order to make ipt_REJECT work with bridges, you also need to enable ip_forward. This patch also fixes a regression. When we used skb_copy_expand(), we didn't have this issue stated above, as the protocol was properly set. Signed-off-by: Changli Gao Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/ipv4/netfilter/ipt_REJECT.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c index b254dafaf429..43eec80c0e7c 100644 --- a/net/ipv4/netfilter/ipt_REJECT.c +++ b/net/ipv4/netfilter/ipt_REJECT.c @@ -112,6 +112,7 @@ static void send_reset(struct sk_buff *oldskb, int hook) /* ip_route_me_harder expects skb->dst to be set */ skb_dst_set_noref(nskb, skb_dst(oldskb)); + nskb->protocol = htons(ETH_P_IP); if (ip_route_me_harder(nskb, addr_type)) goto free_nskb; -- 2.34.1