diff options
Diffstat (limited to 'net/dsa/tag_8021q.c')
| -rw-r--r-- | net/dsa/tag_8021q.c | 57 |
1 files changed, 37 insertions, 20 deletions
diff --git a/net/dsa/tag_8021q.c b/net/dsa/tag_8021q.c index 65a35e976d7b..6ebbd799c4eb 100644 --- a/net/dsa/tag_8021q.c +++ b/net/dsa/tag_8021q.c @@ -235,31 +235,48 @@ struct sk_buff *dsa_8021q_xmit(struct sk_buff *skb, struct net_device *netdev, } EXPORT_SYMBOL_GPL(dsa_8021q_xmit); -struct sk_buff *dsa_8021q_rcv(struct sk_buff *skb, struct net_device *netdev, - struct packet_type *pt, u16 *tpid, u16 *tci) +/* In the DSA packet_type handler, skb->data points in the middle of the VLAN + * tag, after tpid and before tci. This is because so far, ETH_HLEN + * (DMAC, SMAC, EtherType) bytes were pulled. + * There are 2 bytes of VLAN tag left in skb->data, and upper + * layers expect the 'real' EtherType to be consumed as well. + * Coincidentally, a VLAN header is also of the same size as + * the number of bytes that need to be pulled. + * + * skb_mac_header skb->data + * | | + * v v + * | | | | | | | | | | | | | | | | | | | + * +-----------------------+-----------------------+-------+-------+-------+ + * | Destination MAC | Source MAC | TPID | TCI | EType | + * +-----------------------+-----------------------+-------+-------+-------+ + * ^ | | + * |<--VLAN_HLEN-->to <---VLAN_HLEN---> + * from | + * >>>>>>> v + * >>>>>>> | | | | | | | | | | | | | | | + * >>>>>>> +-----------------------+-----------------------+-------+ + * >>>>>>> | Destination MAC | Source MAC | EType | + * +-----------------------+-----------------------+-------+ + * ^ ^ + * (now part of | | + * skb->head) skb_mac_header skb->data + */ +struct sk_buff *dsa_8021q_remove_header(struct sk_buff *skb) { - struct vlan_ethhdr *tag; - - if (unlikely(!pskb_may_pull(skb, VLAN_HLEN))) - return NULL; + u8 *from = skb_mac_header(skb); + u8 *dest = from + VLAN_HLEN; - tag = vlan_eth_hdr(skb); - *tpid = ntohs(tag->h_vlan_proto); - *tci = ntohs(tag->h_vlan_TCI); - - /* skb->data points in the middle of the VLAN tag, - * after tpid and before tci. This is because so far, - * ETH_HLEN (DMAC, SMAC, EtherType) bytes were pulled. - * There are 2 bytes of VLAN tag left in skb->data, and upper - * layers expect the 'real' EtherType to be consumed as well. - * Coincidentally, a VLAN header is also of the same size as - * the number of bytes that need to be pulled. - */ - skb_pull_rcsum(skb, VLAN_HLEN); + memmove(dest, from, ETH_HLEN - VLAN_HLEN); + skb_pull(skb, VLAN_HLEN); + skb_push(skb, ETH_HLEN); + skb_reset_mac_header(skb); + skb_reset_mac_len(skb); + skb_pull_rcsum(skb, ETH_HLEN); return skb; } -EXPORT_SYMBOL_GPL(dsa_8021q_rcv); +EXPORT_SYMBOL_GPL(dsa_8021q_remove_header); static const struct dsa_device_ops dsa_8021q_netdev_ops = { .name = "8021q", |