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_dev.c b/net/8021q/vlan_dev.c
index 7cb285f..3d59c9b 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -142,6 +142,7 @@
{
struct vlan_hdr *vhdr;
struct vlan_rx_stats *rx_stats;
+ struct net_device *vlan_dev;
u16 vlan_id;
u16 vlan_tci;
@@ -157,55 +158,71 @@
vlan_id = vlan_tci & VLAN_VID_MASK;
rcu_read_lock();
- skb->dev = __find_vlan_dev(dev, vlan_id);
- if (!skb->dev) {
- pr_debug("%s: ERROR: No net_device for VID: %u on dev: %s\n",
- __func__, vlan_id, dev->name);
- goto err_unlock;
- }
+ vlan_dev = __find_vlan_dev(dev, vlan_id);
- rx_stats = per_cpu_ptr(vlan_dev_info(skb->dev)->vlan_rx_stats,
- smp_processor_id());
- u64_stats_update_begin(&rx_stats->syncp);
- rx_stats->rx_packets++;
- rx_stats->rx_bytes += skb->len;
+ /* If the VLAN device is defined, we use it.
+ * If not, and the VID is 0, it is a 802.1p packet (not
+ * really a VLAN), so we will just netif_rx it later to the
+ * original interface, but with the skb->proto set to the
+ * wrapped proto: we do nothing here.
+ */
+
+ if (!vlan_dev) {
+ if (vlan_id) {
+ pr_debug("%s: ERROR: No net_device for VID: %u on dev: %s\n",
+ __func__, vlan_id, dev->name);
+ goto err_unlock;
+ }
+ rx_stats = NULL;
+ } else {
+ skb->dev = vlan_dev;
+
+ rx_stats = per_cpu_ptr(vlan_dev_info(skb->dev)->vlan_rx_stats,
+ smp_processor_id());
+ u64_stats_update_begin(&rx_stats->syncp);
+ rx_stats->rx_packets++;
+ rx_stats->rx_bytes += skb->len;
+
+ skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tci);
+
+ pr_debug("%s: priority: %u for TCI: %hu\n",
+ __func__, skb->priority, vlan_tci);
+
+ switch (skb->pkt_type) {
+ case PACKET_BROADCAST:
+ /* Yeah, stats collect these together.. */
+ /* stats->broadcast ++; // no such counter :-( */
+ break;
+
+ case PACKET_MULTICAST:
+ rx_stats->rx_multicast++;
+ break;
+
+ case PACKET_OTHERHOST:
+ /* Our lower layer thinks this is not local, let's make
+ * sure.
+ * This allows the VLAN to have a different MAC than the
+ * underlying device, and still route correctly.
+ */
+ if (!compare_ether_addr(eth_hdr(skb)->h_dest,
+ skb->dev->dev_addr))
+ skb->pkt_type = PACKET_HOST;
+ break;
+ default:
+ break;
+ }
+ u64_stats_update_end(&rx_stats->syncp);
+ }
skb_pull_rcsum(skb, VLAN_HLEN);
-
- skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tci);
-
- pr_debug("%s: priority: %u for TCI: %hu\n",
- __func__, skb->priority, vlan_tci);
-
- switch (skb->pkt_type) {
- case PACKET_BROADCAST: /* Yeah, stats collect these together.. */
- /* stats->broadcast ++; // no such counter :-( */
- break;
-
- case PACKET_MULTICAST:
- rx_stats->rx_multicast++;
- break;
-
- case PACKET_OTHERHOST:
- /* Our lower layer thinks this is not local, let's make sure.
- * This allows the VLAN to have a different MAC than the
- * underlying device, and still route correctly.
- */
- if (!compare_ether_addr(eth_hdr(skb)->h_dest,
- skb->dev->dev_addr))
- skb->pkt_type = PACKET_HOST;
- break;
- default:
- break;
- }
- u64_stats_update_end(&rx_stats->syncp);
-
vlan_set_encap_proto(skb, vhdr);
- skb = vlan_check_reorder_header(skb);
- if (!skb) {
- rx_stats->rx_errors++;
- goto err_unlock;
+ if (vlan_dev) {
+ skb = vlan_check_reorder_header(skb);
+ if (!skb) {
+ rx_stats->rx_errors++;
+ goto err_unlock;
+ }
}
netif_rx(skb);