| Message ID | 20150417053209.GA23855@gondor.apana.org.au |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Fri, Apr 17, 2015 at 01:32:09PM +0800, Herbert Xu wrote: > When you redirect a VLAN device to any device, you end up with > crap in af_packet on the xmit path because hard_header_len is > not equal to skb->mac_len. So the redirected packet contains > four extra bytes at the start which then gets interpreted as > part of the MAC address. > > This patch fixes this by only pushing skb->mac_len. We also > need to fix ifb because it tries to undo the pushing done by > act_mirred. > > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Alexei Starovoitov <ast@plumgrid.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Herbert Xu <herbert@gondor.apana.org.au> Date: Fri, 17 Apr 2015 13:32:09 +0800 > On Thu, Apr 16, 2015 at 07:40:30PM -0700, Alexei Starovoitov wrote: >> On Fri, Apr 17, 2015 at 10:15:01AM +0800, Herbert Xu wrote: >> > > seems the cleaner fix will be to push skb->mac_len instead? >> > >> > No skb->mac_len is the same as skb2->dev->hard_header_len. >> >> hmm. please help me understand the problem then. >> In the commit log you mentioned that your vlan dev and ifb >> have unequal hard header length. I think that can only happen if >> your master dev used to create vlan, didn't have vlan offload, >> so vlandev->hhl = 18 and ifb->hhl = 14. Then when tagged packet >> arrives on master device we call skb_vlan_untag() and >> skb->mac_len becomes 14, then vlan_do_receive() will do > > You are right. I should've just used mac_len. > > ---8<--- > When you redirect a VLAN device to any device, you end up with > crap in af_packet on the xmit path because hard_header_len is > not equal to skb->mac_len. So the redirected packet contains > four extra bytes at the start which then gets interpreted as > part of the MAC address. > > This patch fixes this by only pushing skb->mac_len. We also > need to fix ifb because it tries to undo the pushing done by > act_mirred. > > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c index 34f846b..94570aa 100644 --- a/drivers/net/ifb.c +++ b/drivers/net/ifb.c @@ -105,7 +105,7 @@ static void ri_tasklet(unsigned long dev) if (from & AT_EGRESS) { dev_queue_xmit(skb); } else if (from & AT_INGRESS) { - skb_pull(skb, skb->dev->hard_header_len); + skb_pull(skb, skb->mac_len); netif_receive_skb(skb); } else BUG(); diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index 5953517..3f63cea 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -157,7 +157,7 @@ static int tcf_mirred(struct sk_buff *skb, const struct tc_action *a, if (!(at & AT_EGRESS)) { if (m->tcfm_ok_push) - skb_push(skb2, skb2->dev->hard_header_len); + skb_push(skb2, skb->mac_len); } /* mirror is always swallowed */