Commit 1349fe9a authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller
Browse files

vlan: clean up vlan_dev_hard_header()

Remove some debugging and excessive comments, merge the two
dev_hard_header calls into one.
Signed-off-by: default avatarPatrick McHardy <>
Signed-off-by: default avatarDavid S. Miller <>
parent 19b9a4e2
......@@ -256,43 +256,18 @@ static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
unsigned int len)
struct vlan_hdr *vhdr;
unsigned int vhdrlen = 0;
u16 vlan_tci = 0;
int rc = 0;
int build_vlan_header = 0;
pr_debug("%s: skb: %p type: %hx len: %u vlan_id: %hx, daddr: %p\n",
__func__, skb, type, len, vlan_dev_info(dev)->vlan_id,
int rc;
if (WARN_ON(skb_headroom(skb) < dev->hard_header_len))
return -ENOSPC;
/* build vlan header only if re_order_header flag is NOT set. This
* fixes some programs that get confused when they see a VLAN device
* sending a frame that is VLAN encoded (the consensus is that the VLAN
* device should look completely like an Ethernet device when the
* REORDER_HEADER flag is set) The drawback to this is some extra
* header shuffling in the hard_start_xmit. Users can turn off this
* REORDER behaviour with the vconfig tool.
if (!(vlan_dev_info(dev)->flags & VLAN_FLAG_REORDER_HDR))
build_vlan_header = 1;
if (build_vlan_header) {
if (!(vlan_dev_info(dev)->flags & VLAN_FLAG_REORDER_HDR)) {
vhdr = (struct vlan_hdr *) skb_push(skb, VLAN_HLEN);
/* build the four bytes that make this a VLAN header. */
/* Now, construct the second two bytes. This field looks
* something like:
* usr_priority: 3 bits (high bits)
* CFI 1 bit
* VLAN ID 12 bits (low bits)
vlan_tci = vlan_dev_info(dev)->vlan_id;
vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb);
vhdr->h_vlan_TCI = htons(vlan_tci);
......@@ -300,37 +275,25 @@ static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
* put the length in here instead. It is up to the 802.2
* layer to carry protocol information.
if (type != ETH_P_802_3)
vhdr->h_vlan_encapsulated_proto = htons(type);
vhdr->h_vlan_encapsulated_proto = htons(len);
skb->protocol = htons(ETH_P_8021Q);
type = ETH_P_8021Q;
vhdrlen = VLAN_HLEN;
/* Before delegating work to the lower layer, enter our MAC-address */
if (saddr == NULL)
saddr = dev->dev_addr;
/* Now make the underlying real hard header */
dev = vlan_dev_info(dev)->real_dev;
if (build_vlan_header) {
/* Now make the underlying real hard header */
rc = dev_hard_header(skb, dev, ETH_P_8021Q, daddr, saddr,
len + VLAN_HLEN);
if (rc > 0)
rc += VLAN_HLEN;
else if (rc < 0)
rc -= VLAN_HLEN;
} else
/* If here, then we'll just make a normal looking ethernet
* frame, but, the hard_start_xmit method will insert the tag
* (it has to be able to do this for bridged and other skbs
* that don't come down the protocol stack in an orderly manner.
rc = dev_hard_header(skb, dev, type, daddr, saddr, len);
rc = dev_hard_header(skb, dev, type, daddr, saddr, len + vhdrlen);
if (rc > 0)
rc += vhdrlen;
return rc;
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