On Wed, 2013-10-16 at 12:16 -0400, Vlad Yasevich wrote:

On 10/16/2013 11:55 AM, Stephen Hemminger wrote:

quoted

On Wed, 16 Oct 2013 17:07:14 +0900
Toshiaki Makita [off-list ref] wrote:

quoted

IEEE 802.1Q says that when we receive priority-tagged (VID 0) frames
use the PVID for the port as its VID.
(See IEEE 802.1Q-2011 6.9.1 and Table 9-2)

Apply the PVID to not only untagged frames but also priority-tagged frames.

Signed-off-by: Toshiaki Makita <redacted>
---
  net/bridge/br_vlan.c | 27 ++++++++++++++++++++-------
  1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 21b6d21..5a9c44a 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c

@@ -189,6 +189,8 @@ out:
  bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
  			struct sk_buff *skb, u16 *vid)
  {
+	int err;
+
  	/* If VLAN filtering is disabled on the bridge, all packets are
  	 * permitted.
  	 */

@@ -201,20 +203,31 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
  	if (!v)
  		return false;

-	if (br_vlan_get_tag(skb, vid)) {
+	err = br_vlan_get_tag(skb, vid);
+	if (!*vid) {
  		u16 pvid = br_get_pvid(v);

Ok, but it looks like br_vlan_get_tag() could be cleaner if it just returned
the tag, and there was another br_vlan_tag_present() function.

Thank you for reviewing.
I agree with you.
I had been afraid that if it affects other codes because
br_vlan_get_tag() is used in many places else, but now I have decided
not to hesitate to change its signature and behavior.

I was just thinking about that as well.  If we make br_vlan_get_tag()
return either the actual tag (if the packet is tagged), or the pvid
if (untagged/prio_tagged), then we can skp most of this.

Hmm... maybe I don't fully understand you.

Is what you intend something like
	br_allowed_ingress(...) {
		...
		vid = br_vlan_get_tag(skb, v);
		if (!tagged(skb)) put_tag(skb, vid); /* untagged */
		else if (!get_vid(skb)) update_vid(skb, vid); /* prio_tagged */
		...
	}

	br_vlan_get_tag(skb, v) {
		if (tagged(skb)) {
			vid = get_vid(skb);
			if (!vid) return get_pvid(v); /* prio_tagged */
			return vid;
		}
		return get_pvid(v); /* untagged */
	}

This needs double check for prio_tagged at br_allowed_ingress() and
br_vlan_get_tag().

Or if we modify skb->vlan_tci at br_vlan_get_tag(), isn't it a little
dangerous to other codes that use this function in order to just get
vid?

I am thinking it makes things simple that br_vlan_get_tag() returns 0 if
(untagged/prio_tagged).

	br_allowed_ingress(...) {
		...
		vid = br_vlan_get_tag(skb);
		if (!vid) {
			vid = get_pvid(v);
			if (!tagged(skb)) put_tag(skb, vid);/* untagged */
			else update_vid(skb, vid); /* prio_tagged */
		}
		...
	}

	br_vlan_get_tag(skb) {
		if (tagged(skb)) return get_vid(skb);
		return 0;
	}

Thanks,

Toshiaki Makita

quoted

Also, does this still work if CONFIG_BRIDGE_VLAN_FILTERING is disabled?

Yes.  br_allowed_ingress becomes an inline if the config option is disabled.

-vlad