Re: [PATCH] 802.1Q VLAN

[Ben Greear <greearb@xxxxxxxxxxxxxxx>]

How does this look?  I think it should fix the problem with
having a new skb created in the __vlan_put_tag() method.


int vlan_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct net_device_stats *stats = vlan_dev_get_stats(dev);
        struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);

        /* Please note, dev_queue_xmit consumes the pkt regardless of the
         * return value.  So, will copy the skb first and free if successful.
         */
        struct sk_buff* skb2 = skb_get(skb);

        /* Handle non-VLAN frames if they are sent to us, for example by DHCP.
         *
         * NOTE: THIS ASSUMES DIX ETHERNET, SPECIFICALLY NOT SUPPORTING
         * OTHER THINGS LIKE FDDI/TokenRing/802.3 SNAPs...
         */

        if (veth->h_vlan_proto != __constant_htons(ETH_P_8021Q)) {
                int orig_headroom = skb_headroom(skb);
                unsigned short veth_TCI;

                /* This is not a VLAN frame...but we can fix that! */
                VLAN_DEV_INFO(dev)->cnt_encap_on_xmit++;

#ifdef VLAN_DEBUG
                printk(VLAN_DBG "%s: proto to encap: 0x%hx (hbo)\n",
                        __FUNCTION__, htons(veth->h_vlan_proto));
#endif
                /* 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)
                 */
                veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;
                veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);

                skb = __vlan_put_tag(skb, veth_TCI);
                if (!skb) {
                        stats->tx_dropped++;
                        /* Free the extra copy, assuming this is a 
non-recoverable
                         * issue and we don't want calling code to retry.
                         */
                        kfree_skb(skb2);
                        return 0;
                }

                if (orig_headroom < VLAN_HLEN) {
                        VLAN_DEV_INFO(dev)->cnt_inc_headroom_on_tx++;
                }
        }

#ifdef VLAN_DEBUG
        printk(VLAN_DBG "%s: about to send skb: %p to dev: %s\n",
                __FUNCTION__, skb, skb->dev->name);
        printk(VLAN_DBG "  %2hx.%2hx.%2hx.%2xh.%2hx.%2hx 
%2hx.%2hx.%2hx.%2hx.%2hx.%2hx %4hx %4hx %4hx\n",
               veth->h_dest[0], veth->h_dest[1], veth->h_dest[2], veth->h_dest[3], 
veth->h_dest[4], veth->h_dest[5],
               veth->h_source[0], veth->h_source[1], veth->h_source[2], 
veth->h_source[3], veth->h_source[4], veth->h_source[5],
               veth->h_vlan_proto, veth->h_vlan_TCI, 
veth->h_vlan_encapsulated_proto);
#endif

        skb->dev = VLAN_DEV_INFO(dev)->real_dev;

        {
                int rv = dev_queue_xmit(skb);
                if (rv == 0) {
                        /* Was success, need to free the skb reference since
                         * we bumped up the user count above.  If there was an
                         * error instead, then the skb2 will not be freed, and 
so
                         * the calling code will be able to re-send it.
                         */

                        stats->tx_packets++; /* for statics only */
                        stats->tx_bytes += skb2->len;

                        kfree_skb(skb2);
                }
                return rv;
        }
}


--
Ben Greear <greearb@xxxxxxxxxxxxxxx>
Candela Technologies Inc  http://www.candelatech.com