Re: [PATCH v2 resend] netfilter: ipt_REJECT can't send TCP reset

[Patrick McHardy <kaber@trash.net>]

On 17.08.2010 09:26, Changli Gao wrote:
> 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.

Applied to nf-2.6.git, thanks.