Netdev Archive on lore.kernel.org
help / color / mirror / Atom feed
* [PATCH net] net/sched: act_skbmod: Skip non-Ethernet packets
@ 2021-07-19 23:41 Peilin Ye
  2021-07-20 14:20 ` patchwork-bot+netdevbpf
  0 siblings, 1 reply; 2+ messages in thread
From: Peilin Ye @ 2021-07-19 23:41 UTC (permalink / raw)
  To: Jamal Hadi Salim, Cong Wang, Jiri Pirko
  Cc: Peilin Ye, David S. Miller, Jakub Kicinski, Cong Wang, netdev,
	linux-kernel, Peilin Ye

From: Peilin Ye <peilin.ye@bytedance.com>

Currently tcf_skbmod_act() assumes that packets use Ethernet as their L2
protocol, which is not always the case.  As an example, for CAN devices:

	$ ip link add dev vcan0 type vcan
	$ ip link set up vcan0
	$ tc qdisc add dev vcan0 root handle 1: htb
	$ tc filter add dev vcan0 parent 1: protocol ip prio 10 \
		matchall action skbmod swap mac

Doing the above silently corrupts all the packets.  Do not perform skbmod
actions for non-Ethernet packets.

Fixes: 86da71b57383 ("net_sched: Introduce skbmod action")
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
---
 net/sched/act_skbmod.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
index 81a1c67335be..8d17a543cc9f 100644
--- a/net/sched/act_skbmod.c
+++ b/net/sched/act_skbmod.c
@@ -6,6 +6,7 @@
 */
 
 #include <linux/module.h>
+#include <linux/if_arp.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/skbuff.h>
@@ -33,6 +34,13 @@ static int tcf_skbmod_act(struct sk_buff *skb, const struct tc_action *a,
 	tcf_lastuse_update(&d->tcf_tm);
 	bstats_cpu_update(this_cpu_ptr(d->common.cpu_bstats), skb);
 
+	action = READ_ONCE(d->tcf_action);
+	if (unlikely(action == TC_ACT_SHOT))
+		goto drop;
+
+	if (!skb->dev || skb->dev->type != ARPHRD_ETHER)
+		return action;
+
 	/* XXX: if you are going to edit more fields beyond ethernet header
 	 * (example when you add IP header replacement or vlan swap)
 	 * then MAX_EDIT_LEN needs to change appropriately
@@ -41,10 +49,6 @@ static int tcf_skbmod_act(struct sk_buff *skb, const struct tc_action *a,
 	if (unlikely(err)) /* best policy is to drop on the floor */
 		goto drop;
 
-	action = READ_ONCE(d->tcf_action);
-	if (unlikely(action == TC_ACT_SHOT))
-		goto drop;
-
 	p = rcu_dereference_bh(d->skbmod_p);
 	flags = p->flags;
 	if (flags & SKBMOD_F_DMAC)
-- 
2.20.1


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH net] net/sched: act_skbmod: Skip non-Ethernet packets
  2021-07-19 23:41 [PATCH net] net/sched: act_skbmod: Skip non-Ethernet packets Peilin Ye
@ 2021-07-20 14:20 ` patchwork-bot+netdevbpf
  0 siblings, 0 replies; 2+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-07-20 14:20 UTC (permalink / raw)
  To: Peilin Ye
  Cc: jhs, xiyou.wangcong, jiri, peilin.ye, davem, kuba, cong.wang,
	netdev, linux-kernel

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Mon, 19 Jul 2021 16:41:24 -0700 you wrote:
> From: Peilin Ye <peilin.ye@bytedance.com>
> 
> Currently tcf_skbmod_act() assumes that packets use Ethernet as their L2
> protocol, which is not always the case.  As an example, for CAN devices:
> 
> 	$ ip link add dev vcan0 type vcan
> 	$ ip link set up vcan0
> 	$ tc qdisc add dev vcan0 root handle 1: htb
> 	$ tc filter add dev vcan0 parent 1: protocol ip prio 10 \
> 		matchall action skbmod swap mac
> 
> [...]

Here is the summary with links:
  - [net] net/sched: act_skbmod: Skip non-Ethernet packets
    https://git.kernel.org/netdev/net/c/727d6a8b7ef3

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html



^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2021-07-20 14:25 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-19 23:41 [PATCH net] net/sched: act_skbmod: Skip non-Ethernet packets Peilin Ye
2021-07-20 14:20 ` patchwork-bot+netdevbpf

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).