[net-next-2.6.git] / net / dsa / tag_trailer.c

/*
 * net/dsa/tag_trailer.c - Trailer tag format handling
 * Copyright (c) 2008-2009 Marvell Semiconductor
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/etherdevice.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include "dsa_priv.h"

netdev_tx_t trailer_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct dsa_slave_priv *p = netdev_priv(dev);
	struct sk_buff *nskb;
	int padlen;
	u8 *trailer;

	dev->stats.tx_packets++;
	dev->stats.tx_bytes += skb->len;

	/*
	 * We have to make sure that the trailer ends up as the very
	 * last 4 bytes of the packet.  This means that we have to pad
	 * the packet to the minimum ethernet frame size, if necessary,
	 * before adding the trailer.
	 */
	padlen = 0;
	if (skb->len < 60)
		padlen = 60 - skb->len;

	nskb = alloc_skb(NET_IP_ALIGN + skb->len + padlen + 4, GFP_ATOMIC);
	if (nskb == NULL) {
		kfree_skb(skb);
		return NETDEV_TX_OK;
	}
	skb_reserve(nskb, NET_IP_ALIGN);

	skb_reset_mac_header(nskb);
	skb_set_network_header(nskb, skb_network_header(skb) - skb->head);
	skb_set_transport_header(nskb, skb_transport_header(skb) - skb->head);
	skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len));
	kfree_skb(skb);

	if (padlen) {
		u8 *pad = skb_put(nskb, padlen);
		memset(pad, 0, padlen);
	}

	trailer = skb_put(nskb, 4);
	trailer[0] = 0x80;
	trailer[1] = 1 << p->port;
	trailer[2] = 0x10;
	trailer[3] = 0x00;

	nskb->protocol = htons(ETH_P_TRAILER);

	nskb->dev = p->parent->dst->master_netdev;
	dev_queue_xmit(nskb);

	return NETDEV_TX_OK;
}

static int trailer_rcv(struct sk_buff *skb, struct net_device *dev,
		       struct packet_type *pt, struct net_device *orig_dev)
{
	struct dsa_switch_tree *dst = dev->dsa_ptr;
	struct dsa_switch *ds;
	u8 *trailer;
	int source_port;

	if (unlikely(dst == NULL))
		goto out_drop;
	ds = dst->ds[0];

	skb = skb_unshare(skb, GFP_ATOMIC);
	if (skb == NULL)
		goto out;

	if (skb_linearize(skb))
		goto out_drop;

	trailer = skb_tail_pointer(skb) - 4;
	if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 ||
	    (trailer[3] & 0xef) != 0x00 || trailer[3] != 0x00)
		goto out_drop;

	source_port = trailer[1] & 7;
	if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL)
		goto out_drop;

	pskb_trim_rcsum(skb, skb->len - 4);

	skb->dev = ds->ports[source_port];
	skb_push(skb, ETH_HLEN);
	skb->pkt_type = PACKET_HOST;
	skb->protocol = eth_type_trans(skb, skb->dev);

	skb->dev->stats.rx_packets++;
	skb->dev->stats.rx_bytes += skb->len;

	netif_receive_skb(skb);

	return 0;

out_drop:
	kfree_skb(skb);
out:
	return 0;
}

static struct packet_type trailer_packet_type __read_mostly = {
	.type	= cpu_to_be16(ETH_P_TRAILER),
	.func	= trailer_rcv,
};

static int __init trailer_init_module(void)
{
	dev_add_pack(&trailer_packet_type);
	return 0;
}
module_init(trailer_init_module);

static void __exit trailer_cleanup_module(void)
{
	dev_remove_pack(&trailer_packet_type);
}
module_exit(trailer_cleanup_module);
Commit	Line	Data
396138f0 LB	1	/*
396138f0 LB	2	* net/dsa/tag_trailer.c - Trailer tag format handling
e84665c9	3	* Copyright (c) 2008-2009 Marvell Semiconductor
396138f0 LB	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*/
	10
	11	#include <linux/etherdevice.h>
	12	#include <linux/list.h>
	13	#include <linux/netdevice.h>
5a0e3ad6	14	#include <linux/slab.h>
396138f0 LB	15	#include "dsa_priv.h"
396138f0 LB	16
6fef4c0c	17	netdev_tx_t trailer_xmit(struct sk_buff skb, struct net_device dev)
396138f0 LB	18	{
	19	struct dsa_slave_priv *p = netdev_priv(dev);
	20	struct sk_buff *nskb;
	21	int padlen;
	22	u8 *trailer;
	23
	24	dev->stats.tx_packets++;
	25	dev->stats.tx_bytes += skb->len;
	26
	27	/*
	28	* We have to make sure that the trailer ends up as the very
	29	* last 4 bytes of the packet. This means that we have to pad
	30	* the packet to the minimum ethernet frame size, if necessary,
	31	* before adding the trailer.
	32	*/
	33	padlen = 0;
	34	if (skb->len < 60)
	35	padlen = 60 - skb->len;
	36
	37	nskb = alloc_skb(NET_IP_ALIGN + skb->len + padlen + 4, GFP_ATOMIC);
	38	if (nskb == NULL) {
	39	kfree_skb(skb);
	40	return NETDEV_TX_OK;
	41	}
	42	skb_reserve(nskb, NET_IP_ALIGN);
	43
	44	skb_reset_mac_header(nskb);
	45	skb_set_network_header(nskb, skb_network_header(skb) - skb->head);
	46	skb_set_transport_header(nskb, skb_transport_header(skb) - skb->head);
	47	skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len));
	48	kfree_skb(skb);
	49
	50	if (padlen) {
	51	u8 *pad = skb_put(nskb, padlen);
	52	memset(pad, 0, padlen);
	53	}
	54
	55	trailer = skb_put(nskb, 4);
	56	trailer[0] = 0x80;
	57	trailer[1] = 1 << p->port;
	58	trailer[2] = 0x10;
	59	trailer[3] = 0x00;
	60
	61	nskb->protocol = htons(ETH_P_TRAILER);
	62
e84665c9	63	nskb->dev = p->parent->dst->master_netdev;
396138f0 LB	64	dev_queue_xmit(nskb);
	65
	66	return NETDEV_TX_OK;
	67	}
	68
	69	static int trailer_rcv(struct sk_buff skb, struct net_device dev,
	70	struct packet_type pt, struct net_device orig_dev)
	71	{
e84665c9 LB	72	struct dsa_switch_tree *dst = dev->dsa_ptr;
e84665c9 LB	73	struct dsa_switch *ds;
396138f0 LB	74	u8 *trailer;
	75	int source_port;
	76
e84665c9	77	if (unlikely(dst == NULL))
396138f0	78	goto out_drop;
e84665c9	79	ds = dst->ds[0];
396138f0 LB	80
	81	skb = skb_unshare(skb, GFP_ATOMIC);
	82	if (skb == NULL)
	83	goto out;
	84
	85	if (skb_linearize(skb))
	86	goto out_drop;
	87
	88	trailer = skb_tail_pointer(skb) - 4;
	89	if (trailer[0] != 0x80 \|\| (trailer[1] & 0xf8) != 0x00 \|\|
	90	(trailer[3] & 0xef) != 0x00 \|\| trailer[3] != 0x00)
	91	goto out_drop;
	92
	93	source_port = trailer[1] & 7;
	94	if (source_port >= DSA_MAX_PORTS \|\| ds->ports[source_port] == NULL)
	95	goto out_drop;
	96
	97	pskb_trim_rcsum(skb, skb->len - 4);
	98
	99	skb->dev = ds->ports[source_port];
	100	skb_push(skb, ETH_HLEN);
14ee6742	101	skb->pkt_type = PACKET_HOST;
396138f0 LB	102	skb->protocol = eth_type_trans(skb, skb->dev);
396138f0 LB	103
396138f0 LB	104	skb->dev->stats.rx_packets++;
	105	skb->dev->stats.rx_bytes += skb->len;
	106
	107	netif_receive_skb(skb);
	108
	109	return 0;
	110
	111	out_drop:
	112	kfree_skb(skb);
	113	out:
	114	return 0;
	115	}
	116
7546dd97	117	static struct packet_type trailer_packet_type __read_mostly = {
09640e63	118	.type = cpu_to_be16(ETH_P_TRAILER),
396138f0 LB	119	.func = trailer_rcv,
	120	};
	121
	122	static int __init trailer_init_module(void)
	123	{
	124	dev_add_pack(&trailer_packet_type);
	125	return 0;
	126	}
	127	module_init(trailer_init_module);
	128
	129	static void __exit trailer_cleanup_module(void)
	130	{
	131	dev_remove_pack(&trailer_packet_type);
	132	}
	133	module_exit(trailer_cleanup_module);