From f569ad52570eca01a8c57a04719b1d71085f1363 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 26 Sep 2020 22:32:09 +0300 Subject: net: dsa: tag_brcm: use generic flow dissector procedure There are 2 Broadcom tags in use, one places the DSA tag before the Ethernet destination MAC address, and the other before the EtherType. Nonetheless, both displace the rest of the headers, so this tagger can use the generic flow dissector procedure which accounts for that. The ASCII art drawing is a good reference though, so keep it but move it somewhere else. Cc: Florian Fainelli Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller --- net/dsa/tag_brcm.c | 34 ++++++++++++---------------------- 1 file changed, 12 insertions(+), 22 deletions(-) (limited to 'net') diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c index 610bc7469667..69d6b8c597a9 100644 --- a/net/dsa/tag_brcm.c +++ b/net/dsa/tag_brcm.c @@ -107,6 +107,18 @@ static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb, return skb; } +/* Frames with this tag have one of these two layouts: + * ----------------------------------- + * | MAC DA | MAC SA | 4b tag | Type | DSA_TAG_PROTO_BRCM + * ----------------------------------- + * ----------------------------------- + * | 4b tag | MAC DA | MAC SA | Type | DSA_TAG_PROTO_BRCM_PREPEND + * ----------------------------------- + * In both cases, at receive time, skb->data points 2 bytes before the actual + * Ethernet type field and we have an offset of 4bytes between where skb->data + * and where the payload starts. So the same low-level receive function can be + * used. + */ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, @@ -149,26 +161,6 @@ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb, return skb; } - -static void brcm_tag_flow_dissect(const struct sk_buff *skb, __be16 *proto, - int *offset) -{ - /* We have been called on the DSA master network device after - * eth_type_trans() which pulled the Ethernet header already. - * Frames have one of these two layouts: - * ----------------------------------- - * | MAC DA | MAC SA | 4b tag | Type | DSA_TAG_PROTO_BRCM - * ----------------------------------- - * ----------------------------------- - * | 4b tag | MAC DA | MAC SA | Type | DSA_TAG_PROTO_BRCM_PREPEND - * ----------------------------------- - * skb->data points 2 bytes before the actual Ethernet type field and - * we have an offset of 4bytes between where skb->data and where the - * payload starts. - */ - *offset = BRCM_TAG_LEN; - *proto = ((__be16 *)skb->data)[1]; -} #endif #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM) @@ -204,7 +196,6 @@ static const struct dsa_device_ops brcm_netdev_ops = { .xmit = brcm_tag_xmit, .rcv = brcm_tag_rcv, .overhead = BRCM_TAG_LEN, - .flow_dissect = brcm_tag_flow_dissect, }; DSA_TAG_DRIVER(brcm_netdev_ops); @@ -239,7 +230,6 @@ static const struct dsa_device_ops brcm_prepend_netdev_ops = { .xmit = brcm_tag_xmit_prepend, .rcv = brcm_tag_rcv_prepend, .overhead = BRCM_TAG_LEN, - .flow_dissect = brcm_tag_flow_dissect, }; DSA_TAG_DRIVER(brcm_prepend_netdev_ops); -- cgit v1.2.3