From 52015366e361a88c569550a285c71f72bb095661 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Sun, 22 Mar 2020 14:09:57 -0700 Subject: [PATCH] net: dsa: Implement flow dissection for tag_brcm.c Provide a flow_dissect callback which returns the network offset and where to find the skb protocol, given the tags structure a common function works for both tagging formats that are supported. Signed-off-by: Florian Fainelli Reviewed-by: Vivien Didelot Signed-off-by: David S. Miller --- net/dsa/tag_brcm.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c index 9c3114179690..0d3f796d14a3 100644 --- a/net/dsa/tag_brcm.c +++ b/net/dsa/tag_brcm.c @@ -142,6 +142,27 @@ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb, return skb; } + +static int 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]; + return 0; +} #endif #if IS_ENABLED(CONFIG_NET_DSA_TAG_BRCM) @@ -177,6 +198,7 @@ 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); @@ -205,6 +227,7 @@ 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);