vlan: deliver packets received with VLAN acceleration to network taps

When VLAN header stripping is used, packets currently bypass packet
sockets (and other network taps) completely. For locally existing
VLANs, they appear directly on the VLAN device, for unknown VLANs
they are silently dropped.

Add a new function netif_nit_deliver() to deliver incoming packets
to all network interface taps and use it in __vlan_hwaccel_rx() to
make VLAN packets visible on the underlying device.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 31 insertions, 0 deletions

diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
index 68df12d3664b..916061f681b6 100644
--- a/net/8021q/vlan_core.c
+++ b/net/8021q/vlan_core.c
@@ -14,6 +14,9 @@ int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
                 return NET_RX_DROP;
         }
 
+        skb->vlan_tci = vlan_tci;
+        netif_nit_deliver(skb);
+
         skb->dev = vlan_group_get_device(grp, vlan_tci & VLAN_VID_MASK);
         if (skb->dev == NULL) {
                 dev_kfree_skb_any(skb);
@@ -22,6 +25,7 @@ int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
                 return NET_RX_SUCCESS;
         }
         skb->dev->last_rx = jiffies;
+        skb->vlan_tci = 0;
 
         stats = &skb->dev->stats;
         stats->rx_packets++;
diff --git a/net/core/dev.c b/net/core/dev.c
index a29a359b15d1..feaab4898a5b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2068,6 +2068,33 @@ out:
 }
 #endif
 
+/*
+ *      netif_nit_deliver - deliver received packets to network taps
+ *      @skb: buffer
+ *
+ *      This function is used to deliver incoming packets to network
+ *      taps. It should be used when the normal netif_receive_skb path
+ *      is bypassed, for example because of VLAN acceleration.
+ */
+void netif_nit_deliver(struct sk_buff *skb)
+{
+        struct packet_type *ptype;
+
+        if (list_empty(&ptype_all))
+                return;
+
+        skb_reset_network_header(skb);
+        skb_reset_transport_header(skb);
+        skb->mac_len = skb->network_header - skb->mac_header;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(ptype, &ptype_all, list) {
+                if (!ptype->dev || ptype->dev == skb->dev)
+                        deliver_skb(skb, ptype, skb->dev);
+        }
+        rcu_read_unlock();
+}
+
 /**
  *      netif_receive_skb - process receive buffer from network
  *      @skb: buffer to process