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 <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
b46ffb8545