vlan_dev: VLAN 0 should be treated as "no vlan tag" (802.1p packet)
- Without the 8021q module loaded in the kernel, all 802.1p packets
(VLAN 0 but QoS tagging) are silently discarded (as expected, as
the protocol is not loaded).
- Without this patch in 8021q module, these packets are forwarded to
the module, but they are discarded also if VLAN 0 is not configured,
which should not be the default behaviour, as VLAN 0 is not really
a VLANed packet but a 802.1p packet. Defining VLAN 0 makes it almost
impossible to communicate with mixed 802.1p and non 802.1p devices on
the same network due to arp table issues.
- Changed logic to skip vlan specific code in vlan_skb_recv if VLAN
is 0 and we have not defined a VLAN with ID 0, but we accept the
packet with the encapsulated proto and pass it later to netif_rx.
- In the vlan device event handler, added some logic to add VLAN 0
to HW filter in devices that support it (this prevented any traffic
in VLAN 0 to reach the stack in e1000e with HW filter under 2.6.35,
and probably also with other HW filtered cards, so we fix it here).
- In the vlan unregister logic, prevent the elimination of VLAN 0
in devices with HW filter.
- The default behaviour is to ignore the VLAN 0 tagging and accept
the packet as if it was not tagged, but we can still define a
VLAN 0 if desired (so it is backwards compatible).
Signed-off-by: Pedro Garcia <pedro.netdev@dondevamos.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 3c1c8c1..a2ad152 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -155,9 +155,10 @@
BUG_ON(!grp);
/* Take it out of our own structures, but be sure to interlock with
- * HW accelerating devices or SW vlan input packet processing.
+ * HW accelerating devices or SW vlan input packet processing if
+ * VLAN is not 0 (leave it there for 802.1p).
*/
- if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
+ if (vlan_id && (real_dev->features & NETIF_F_HW_VLAN_FILTER))
ops->ndo_vlan_rx_kill_vid(real_dev, vlan_id);
grp->nr_vlans--;
@@ -419,6 +420,14 @@
if (is_vlan_dev(dev))
__vlan_device_event(dev, event);
+ if ((event == NETDEV_UP) &&
+ (dev->features & NETIF_F_HW_VLAN_FILTER) &&
+ dev->netdev_ops->ndo_vlan_rx_add_vid) {
+ pr_info("8021q: adding VLAN 0 to HW filter on device %s\n",
+ dev->name);
+ dev->netdev_ops->ndo_vlan_rx_add_vid(dev, 0);
+ }
+
grp = __vlan_find_group(dev);
if (!grp)
goto out;