net: vlan: add protocol argument to packet tagging functions

Add a protocol argument to the VLAN packet tagging functions. In case of HW
tagging, we need that protocol available in the ndo_start_xmit functions,
so it is stored in a new field in the skb. The new field fits into a hole
(on 64 bit) and doesn't increase the sks's size.

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

2 files changed, 26 insertions, 9 deletions

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 2c9fb65f8267..8086ff9988b1 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -157,9 +157,18 @@ static inline bool vlan_uses_dev(const struct net_device *dev)
 }
 #endif
 
+static inline bool vlan_hw_offload_capable(netdev_features_t features,
+                                           __be16 proto)
+{
+        if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
+                return true;
+        return false;
+}
+
 /**
  * vlan_insert_tag - regular VLAN tag inserting
  * @skb: skbuff to tag
+ * @vlan_proto: VLAN encapsulation protocol
  * @vlan_tci: VLAN TCI to insert
  *
  * Inserts the VLAN tag into @skb as part of the payload
@@ -170,7 +179,8 @@ static inline bool vlan_uses_dev(const struct net_device *dev)
  *
  * Does not change skb->protocol so this function can be used during receive.
  */
-static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
+static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
+                                              __be16 vlan_proto, u16 vlan_tci)
 {
         struct vlan_ethhdr *veth;
 
@@ -185,7 +195,7 @@ static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
         skb->mac_header -= VLAN_HLEN;
 
         /* first, the ethernet type */
-        veth->h_vlan_proto = htons(ETH_P_8021Q);
+        veth->h_vlan_proto = vlan_proto;
 
         /* now, the TCI */
         veth->h_vlan_TCI = htons(vlan_tci);
@@ -204,24 +214,28 @@ static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
  * Following the skb_unshare() example, in case of error, the calling function
  * doesn't have to worry about freeing the original skb.
  */
-static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
+static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb,
+                                             __be16 vlan_proto, u16 vlan_tci)
 {
-        skb = vlan_insert_tag(skb, vlan_tci);
+        skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
         if (skb)
-                skb->protocol = htons(ETH_P_8021Q);
+                skb->protocol = vlan_proto;
         return skb;
 }
 
 /**
  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
  * @skb: skbuff to tag
+ * @vlan_proto: VLAN encapsulation protocol
  * @vlan_tci: VLAN TCI to insert
  *
  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
  */
 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
+                                                     __be16 vlan_proto,
                                                      u16 vlan_tci)
 {
+        skb->vlan_proto = vlan_proto;
         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
         return skb;
 }
@@ -236,12 +250,13 @@ static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
  * Assumes skb->dev is the target that will xmit this frame.
  * Returns a VLAN tagged skb.
  */
-static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
+static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb,
+                                           __be16 vlan_proto, u16 vlan_tci)
 {
-        if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
-                return __vlan_hwaccel_put_tag(skb, vlan_tci);
+        if (vlan_hw_offload_capable(skb->dev->features, vlan_proto)) {
+                return __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
         } else {
-                return __vlan_put_tag(skb, vlan_tci);
+                return __vlan_put_tag(skb, vlan_proto, vlan_tci);
         }
 }
 
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index e27d1c782f32..f5bed7b31954 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -387,6 +387,7 @@ typedef unsigned char *sk_buff_data_t;
  *      @secmark: security marking
  *      @mark: Generic packet mark
  *      @dropcount: total number of sk_receive_queue overflows
+ *      @vlan_proto: vlan encapsulation protocol
  *      @vlan_tci: vlan tag control information
  *      @inner_transport_header: Inner transport layer header (encapsulation)
  *      @inner_network_header: Network layer header (encapsulation)
@@ -465,6 +466,7 @@ struct sk_buff {
 
         __u32                   rxhash;
 
+        __be16                  vlan_proto;
         __u16                   vlan_tci;
 
 #ifdef CONFIG_NET_SCHED