09640e6365
Base versions handle constant folding now. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
195 lines
4.4 KiB
C
195 lines
4.4 KiB
C
/*
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* net/dsa/tag_dsa.c - (Non-ethertype) DSA tagging
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* Copyright (c) 2008 Marvell Semiconductor
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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/netdevice.h>
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#include "dsa_priv.h"
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#define DSA_HLEN 4
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int dsa_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 *dsa_header;
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dev->stats.tx_packets++;
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dev->stats.tx_bytes += skb->len;
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/*
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* Convert the outermost 802.1q tag to a DSA tag for tagged
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* packets, or insert a DSA tag between the addresses and
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* the ethertype field for untagged packets.
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*/
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if (skb->protocol == htons(ETH_P_8021Q)) {
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if (skb_cow_head(skb, 0) < 0)
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goto out_free;
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/*
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* Construct tagged FROM_CPU DSA tag from 802.1q tag.
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*/
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dsa_header = skb->data + 2 * ETH_ALEN;
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dsa_header[0] = 0x60;
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dsa_header[1] = p->port << 3;
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/*
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* Move CFI field from byte 2 to byte 1.
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*/
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if (dsa_header[2] & 0x10) {
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dsa_header[1] |= 0x01;
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dsa_header[2] &= ~0x10;
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}
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} else {
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if (skb_cow_head(skb, DSA_HLEN) < 0)
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goto out_free;
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skb_push(skb, DSA_HLEN);
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memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN);
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/*
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* Construct untagged FROM_CPU DSA tag.
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*/
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dsa_header = skb->data + 2 * ETH_ALEN;
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dsa_header[0] = 0x40;
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dsa_header[1] = p->port << 3;
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dsa_header[2] = 0x00;
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dsa_header[3] = 0x00;
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}
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skb->protocol = htons(ETH_P_DSA);
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skb->dev = p->parent->master_netdev;
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dev_queue_xmit(skb);
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return NETDEV_TX_OK;
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out_free:
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kfree_skb(skb);
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return NETDEV_TX_OK;
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}
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static int dsa_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 *ds = dev->dsa_ptr;
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u8 *dsa_header;
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int source_port;
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if (unlikely(ds == NULL))
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goto out_drop;
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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, DSA_HLEN)))
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goto out_drop;
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/*
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* The ethertype field is part of the DSA header.
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*/
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dsa_header = skb->data - 2;
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/*
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* Check that frame type is either TO_CPU or FORWARD, and
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* that the source device is zero.
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*/
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if ((dsa_header[0] & 0xdf) != 0x00 && (dsa_header[0] & 0xdf) != 0xc0)
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goto out_drop;
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/*
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* Check that the source port is a registered DSA port.
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*/
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source_port = (dsa_header[1] >> 3) & 0x1f;
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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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/*
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* Convert the DSA header to an 802.1q header if the 'tagged'
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* bit in the DSA header is set. If the 'tagged' bit is clear,
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* delete the DSA header entirely.
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*/
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if (dsa_header[0] & 0x20) {
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u8 new_header[4];
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/*
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* Insert 802.1q ethertype and copy the VLAN-related
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* fields, but clear the bit that will hold CFI (since
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* DSA uses that bit location for another purpose).
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*/
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new_header[0] = (ETH_P_8021Q >> 8) & 0xff;
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new_header[1] = ETH_P_8021Q & 0xff;
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new_header[2] = dsa_header[2] & ~0x10;
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new_header[3] = dsa_header[3];
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/*
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* Move CFI bit from its place in the DSA header to
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* its 802.1q-designated place.
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*/
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if (dsa_header[1] & 0x01)
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new_header[2] |= 0x10;
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/*
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* Update packet checksum if skb is CHECKSUM_COMPLETE.
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*/
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if (skb->ip_summed == CHECKSUM_COMPLETE) {
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__wsum c = skb->csum;
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c = csum_add(c, csum_partial(new_header + 2, 2, 0));
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c = csum_sub(c, csum_partial(dsa_header + 2, 2, 0));
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skb->csum = c;
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}
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memcpy(dsa_header, new_header, DSA_HLEN);
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} else {
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/*
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* Remove DSA tag and update checksum.
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*/
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skb_pull_rcsum(skb, DSA_HLEN);
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memmove(skb->data - ETH_HLEN,
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skb->data - ETH_HLEN - DSA_HLEN,
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2 * ETH_ALEN);
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}
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skb->dev = ds->ports[source_port];
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skb_push(skb, ETH_HLEN);
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skb->pkt_type = PACKET_HOST;
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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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static struct packet_type dsa_packet_type = {
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.type = cpu_to_be16(ETH_P_DSA),
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.func = dsa_rcv,
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};
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static int __init dsa_init_module(void)
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{
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dev_add_pack(&dsa_packet_type);
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return 0;
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}
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module_init(dsa_init_module);
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static void __exit dsa_cleanup_module(void)
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{
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dev_remove_pack(&dsa_packet_type);
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}
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module_exit(dsa_cleanup_module);
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