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

/*
 * net/dsa/tag_trailer.c - Trailer tag format handling
 * Copyright (c) 2008 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 "dsa_priv.h"

int 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->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 *ds = dev->dsa_ptr;
	u8 *trailer;
	int source_port;

	if (unlikely(ds == NULL))
		goto out_drop;

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