4ed70ce9f0
All tagging protocols do the same thing: increment device statistics, make room for the tag to be inserted, create the tag, invoke the parent network device transmit function. In order to prepare for adding netpoll support, which requires the tag creation, but not using the parent network device transmit function, do some little refactoring which eliminates duplication between the 4 tagging protocols supported. We need to return a sk_buff pointer back to the caller because the tag specific transmit function may have to reallocate the original skb (e.g: tag_trailer.c) and this is the one we should be transmitting, not the original sk_buff we were passed. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
163 lines
4 KiB
C
163 lines
4 KiB
C
/*
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* Broadcom tag support
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*
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* Copyright (C) 2014 Broadcom Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/etherdevice.h>
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#include <linux/list.h>
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#include <linux/slab.h>
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#include "dsa_priv.h"
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/* This tag length is 4 bytes, older ones were 6 bytes, we do not
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* handle them
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*/
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#define BRCM_TAG_LEN 4
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/* Tag is constructed and desconstructed using byte by byte access
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* because the tag is placed after the MAC Source Address, which does
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* not make it 4-bytes aligned, so this might cause unaligned accesses
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* on most systems where this is used.
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*/
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/* Ingress and egress opcodes */
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#define BRCM_OPCODE_SHIFT 5
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#define BRCM_OPCODE_MASK 0x7
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/* Ingress fields */
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/* 1st byte in the tag */
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#define BRCM_IG_TC_SHIFT 2
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#define BRCM_IG_TC_MASK 0x7
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/* 2nd byte in the tag */
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#define BRCM_IG_TE_MASK 0x3
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#define BRCM_IG_TS_SHIFT 7
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/* 3rd byte in the tag */
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#define BRCM_IG_DSTMAP2_MASK 1
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#define BRCM_IG_DSTMAP1_MASK 0xff
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/* Egress fields */
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/* 2nd byte in the tag */
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#define BRCM_EG_CID_MASK 0xff
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/* 3rd byte in the tag */
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#define BRCM_EG_RC_MASK 0xff
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#define BRCM_EG_RC_RSVD (3 << 6)
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#define BRCM_EG_RC_EXCEPTION (1 << 5)
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#define BRCM_EG_RC_PROT_SNOOP (1 << 4)
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#define BRCM_EG_RC_PROT_TERM (1 << 3)
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#define BRCM_EG_RC_SWITCH (1 << 2)
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#define BRCM_EG_RC_MAC_LEARN (1 << 1)
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#define BRCM_EG_RC_MIRROR (1 << 0)
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#define BRCM_EG_TC_SHIFT 5
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#define BRCM_EG_TC_MASK 0x7
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#define BRCM_EG_PID_MASK 0x1f
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static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev)
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{
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struct dsa_slave_priv *p = netdev_priv(dev);
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u8 *brcm_tag;
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if (skb_cow_head(skb, BRCM_TAG_LEN) < 0)
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goto out_free;
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skb_push(skb, BRCM_TAG_LEN);
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memmove(skb->data, skb->data + BRCM_TAG_LEN, 2 * ETH_ALEN);
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/* Build the tag after the MAC Source Address */
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brcm_tag = skb->data + 2 * ETH_ALEN;
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/* Set the ingress opcode, traffic class, tag enforcment is
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* deprecated
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*/
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brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) |
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((skb->priority << BRCM_IG_TC_SHIFT) & BRCM_IG_TC_MASK);
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brcm_tag[1] = 0;
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brcm_tag[2] = 0;
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if (p->port == 8)
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brcm_tag[2] = BRCM_IG_DSTMAP2_MASK;
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brcm_tag[3] = (1 << p->port) & BRCM_IG_DSTMAP1_MASK;
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return skb;
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out_free:
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kfree_skb(skb);
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return NULL;
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}
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static int brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev,
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struct packet_type *pt, struct net_device *orig_dev)
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{
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struct dsa_switch_tree *dst = dev->dsa_ptr;
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struct dsa_switch *ds;
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int source_port;
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u8 *brcm_tag;
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if (unlikely(dst == NULL))
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goto out_drop;
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ds = dst->ds[0];
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skb = skb_unshare(skb, GFP_ATOMIC);
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if (skb == NULL)
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goto out;
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if (unlikely(!pskb_may_pull(skb, BRCM_TAG_LEN)))
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goto out_drop;
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/* skb->data points to the EtherType, the tag is right before it */
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brcm_tag = skb->data - 2;
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/* The opcode should never be different than 0b000 */
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if (unlikely((brcm_tag[0] >> BRCM_OPCODE_SHIFT) & BRCM_OPCODE_MASK))
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goto out_drop;
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/* We should never see a reserved reason code without knowing how to
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* handle it
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*/
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WARN_ON(brcm_tag[2] & BRCM_EG_RC_RSVD);
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/* Locate which port this is coming from */
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source_port = brcm_tag[3] & BRCM_EG_PID_MASK;
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/* Validate port against switch setup, either the port is totally */
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if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL)
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goto out_drop;
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/* Remove Broadcom tag and update checksum */
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skb_pull_rcsum(skb, BRCM_TAG_LEN);
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/* Move the Ethernet DA and SA */
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memmove(skb->data - ETH_HLEN,
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skb->data - ETH_HLEN - BRCM_TAG_LEN,
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2 * ETH_ALEN);
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skb_push(skb, ETH_HLEN);
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skb->pkt_type = PACKET_HOST;
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skb->dev = ds->ports[source_port];
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skb->protocol = eth_type_trans(skb, skb->dev);
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skb->dev->stats.rx_packets++;
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skb->dev->stats.rx_bytes += skb->len;
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netif_receive_skb(skb);
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return 0;
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out_drop:
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kfree_skb(skb);
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out:
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return 0;
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}
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const struct dsa_device_ops brcm_netdev_ops = {
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.xmit = brcm_tag_xmit,
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.rcv = brcm_tag_rcv,
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};
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