From: Jiri Pirko <jiri@resnulli•us>
To: Daniel Borkmann <dborkman@redhat•com>
Cc: David Miller <davem@davemloft•net>,
netdev@vger•kernel.org, Eric Dumazet <eric.dumazet@gmail•com>,
Ani Sinha <ani@aristanetworks•com>,
Jiri Pirko <jpirko@redhat•com>
Subject: Re: [PATCH net 1/2] net: dev_queue_xmit_nit: fix skb->vlan_tci field value
Date: Tue, 8 Jan 2013 21:14:50 +0100 [thread overview]
Message-ID: <20130108201450.GD1621@minipsycho.orion> (raw)
In-Reply-To: <1357671093-9605-2-git-send-email-dborkman@redhat.com>
Tue, Jan 08, 2013 at 07:51:32PM CET, dborkman@redhat•com wrote:
>VLAN packets that are locally injected through taps will loose their
>skb->vlan_tci value when they pass dev_hard_start_xmit and get looped
>back to a packet sniffer via dev_queue_xmit_nit. Besides others, this
>meta data is used in Linux socket filtering for VLANs. Tested with a
>VLAN ancillary ops filter.
>
>Patch is based on a previous version by Jiri Pirko.
>
>Cc: Eric Dumazet <eric.dumazet@gmail•com>
>Cc: Ani Sinha <ani@aristanetworks•com>
>Cc: Jiri Pirko <jpirko@redhat•com>
>Reported-by: Paul Pearce <pearce@cs•berkeley.edu>
>Signed-off-by: Daniel Borkmann <dborkman@redhat•com>
>---
> net/core/dev.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
>diff --git a/net/core/dev.c b/net/core/dev.c
>index 515473e..723dcd0 100644
>--- a/net/core/dev.c
>+++ b/net/core/dev.c
>@@ -1775,6 +1775,19 @@ static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
> struct packet_type *ptype;
> struct sk_buff *skb2 = NULL;
> struct packet_type *pt_prev = NULL;
>+ struct ethhdr *ehdr;
>+
>+ /* Network taps could make use of skb->vlan_tci, which got wiped
>+ * out. Hence, we need to reset it correctly.
>+ */
>+ skb_reset_mac_header(skb);
>+ ehdr = eth_hdr(skb);
>+
>+ if (ehdr->h_proto == __constant_htons(ETH_P_8021Q)) {
>+ skb2 = vlan_untag(skb);
>+ if (likely(skb2))
>+ skb = skb2;
>+ }
Hmm, nitpick, I think that better would be to do:
skb = vlan_untag(skb);
if (unlikely(!skb))
return;
I believe that better is to deliver skbs in consistent way and
to do not deliver at all in case of -ENOMEM
next prev parent reply other threads:[~2013-01-08 20:14 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-08 18:51 [PATCH net 0/2] net: dev_queue_xmit_nit fixes Daniel Borkmann
2013-01-08 18:51 ` [PATCH net 1/2] net: dev_queue_xmit_nit: fix skb->vlan_tci field value Daniel Borkmann
2013-01-08 19:54 ` Ani Sinha
2013-01-08 20:04 ` Eric Dumazet
2013-01-08 20:22 ` Jiri Pirko
2013-01-08 20:42 ` Eric Dumazet
2013-01-08 20:14 ` Jiri Pirko [this message]
2013-01-08 18:51 ` [PATCH net 2/2] net: dev_queue_xmit_nit: fix potential NULL ptr dereference Daniel Borkmann
2013-01-08 19:22 ` Eric Dumazet
2013-01-08 19:38 ` Daniel Borkmann
-- strict thread matches above, loose matches on Subject: below --
2013-01-09 5:15 [PATCH net 1/2] net: dev_queue_xmit_nit: fix skb->vlan_tci field value Paul Pearce
2013-01-09 6:06 ` Ani Sinha
2013-01-09 6:27 ` Eric Dumazet
2013-01-09 6:34 ` Ani Sinha
2013-01-09 19:27 ` Ani Sinha
2013-01-09 19:51 ` Eric Dumazet
2013-01-09 20:01 ` Ani Sinha
2013-01-09 20:06 ` Ani Sinha
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