[linux.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/slab.h>
#include "dsa_priv.h"

static 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;
}

const struct dsa_device_ops trailer_netdev_ops = {
	.xmit	= trailer_xmit,
	.rcv	= trailer_rcv,
};
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>
5a0e3ad6	13	#include <linux/slab.h>
396138f0 LB	14	#include "dsa_priv.h"
396138f0 LB	15
3e8a72d1	16	static netdev_tx_t trailer_xmit(struct sk_buff skb, struct net_device dev)
396138f0 LB	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
e84665c9	62	nskb->dev = p->parent->dst->master_netdev;
396138f0 LB	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	{
e84665c9 LB	71	struct dsa_switch_tree *dst = dev->dsa_ptr;
e84665c9 LB	72	struct dsa_switch *ds;
396138f0 LB	73	u8 *trailer;
	74	int source_port;
	75
e84665c9	76	if (unlikely(dst == NULL))
396138f0	77	goto out_drop;
e84665c9	78	ds = dst->ds[0];
396138f0 LB	79
	80	skb = skb_unshare(skb, GFP_ATOMIC);
	81	if (skb == NULL)
	82	goto out;
	83
	84	if (skb_linearize(skb))
	85	goto out_drop;
	86
	87	trailer = skb_tail_pointer(skb) - 4;
	88	if (trailer[0] != 0x80 \|\| (trailer[1] & 0xf8) != 0x00 \|\|
	89	(trailer[3] & 0xef) != 0x00 \|\| trailer[3] != 0x00)
	90	goto out_drop;
	91
	92	source_port = trailer[1] & 7;
	93	if (source_port >= DSA_MAX_PORTS \|\| ds->ports[source_port] == NULL)
	94	goto out_drop;
	95
	96	pskb_trim_rcsum(skb, skb->len - 4);
	97
	98	skb->dev = ds->ports[source_port];
	99	skb_push(skb, ETH_HLEN);
14ee6742	100	skb->pkt_type = PACKET_HOST;
396138f0 LB	101	skb->protocol = eth_type_trans(skb, skb->dev);
396138f0 LB	102
396138f0 LB	103	skb->dev->stats.rx_packets++;
	104	skb->dev->stats.rx_bytes += skb->len;
	105
	106	netif_receive_skb(skb);
	107
	108	return 0;
	109
	110	out_drop:
	111	kfree_skb(skb);
	112	out:
	113	return 0;
	114	}
	115
3e8a72d1 FF	116	const struct dsa_device_ops trailer_netdev_ops = {
	117	.xmit = trailer_xmit,
	118	.rcv = trailer_rcv,
396138f0	119	};