[linux-2.6-block.git] / net / dsa / tag_edsa.c

/*
 * net/dsa/tag_edsa.c - Ethertype DSA tagging
 * 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"

#define DSA_HLEN	4
#define EDSA_HLEN	8

int edsa_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct dsa_slave_priv *p = netdev_priv(dev);
	u8 *edsa_header;

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

	/*
	 * Convert the outermost 802.1q tag to a DSA tag and prepend
	 * a DSA ethertype field is the packet is tagged, or insert
	 * a DSA ethertype plus DSA tag between the addresses and the
	 * current ethertype field if the packet is untagged.
	 */
	if (skb->protocol == htons(ETH_P_8021Q)) {
		if (skb_cow_head(skb, DSA_HLEN) < 0)
			goto out_free;
		skb_push(skb, DSA_HLEN);

		memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN);

		/*
		 * Construct tagged FROM_CPU DSA tag from 802.1q tag.
		 */
		edsa_header = skb->data + 2 * ETH_ALEN;
		edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff;
		edsa_header[1] = ETH_P_EDSA & 0xff;
		edsa_header[2] = 0x00;
		edsa_header[3] = 0x00;
		edsa_header[4] = 0x60;
		edsa_header[5] = p->port << 3;

		/*
		 * Move CFI field from byte 6 to byte 5.
		 */
		if (edsa_header[6] & 0x10) {
			edsa_header[5] |= 0x01;
			edsa_header[6] &= ~0x10;
		}
	} else {
		if (skb_cow_head(skb, EDSA_HLEN) < 0)
			goto out_free;
		skb_push(skb, EDSA_HLEN);

		memmove(skb->data, skb->data + EDSA_HLEN, 2 * ETH_ALEN);

		/*
		 * Construct untagged FROM_CPU DSA tag.
		 */
		edsa_header = skb->data + 2 * ETH_ALEN;
		edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff;
		edsa_header[1] = ETH_P_EDSA & 0xff;
		edsa_header[2] = 0x00;
		edsa_header[3] = 0x00;
		edsa_header[4] = 0x40;
		edsa_header[5] = p->port << 3;
		edsa_header[6] = 0x00;
		edsa_header[7] = 0x00;
	}

	skb->protocol = htons(ETH_P_EDSA);

	skb->dev = p->parent->master_netdev;
	dev_queue_xmit(skb);

	return NETDEV_TX_OK;

out_free:
	kfree_skb(skb);
	return NETDEV_TX_OK;
}

static int edsa_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 *edsa_header;
	int source_port;

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

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

	if (unlikely(!pskb_may_pull(skb, EDSA_HLEN)))
		goto out_drop;

	/*
	 * Skip the two null bytes after the ethertype.
	 */
	edsa_header = skb->data + 2;

	/*
	 * Check that frame type is either TO_CPU or FORWARD, and
	 * that the source device is zero.
	 */
	if ((edsa_header[0] & 0xdf) != 0x00 && (edsa_header[0] & 0xdf) != 0xc0)
		goto out_drop;

	/*
	 * Check that the source port is a registered DSA port.
	 */
	source_port = (edsa_header[1] >> 3) & 0x1f;
	if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL)
		goto out_drop;

	/*
	 * If the 'tagged' bit is set, convert the DSA tag to a 802.1q
	 * tag and delete the ethertype part.  If the 'tagged' bit is
	 * clear, delete the ethertype and the DSA tag parts.
	 */
	if (edsa_header[0] & 0x20) {
		u8 new_header[4];

		/*
		 * Insert 802.1q ethertype and copy the VLAN-related
		 * fields, but clear the bit that will hold CFI (since
		 * DSA uses that bit location for another purpose).
		 */
		new_header[0] = (ETH_P_8021Q >> 8) & 0xff;
		new_header[1] = ETH_P_8021Q & 0xff;
		new_header[2] = edsa_header[2] & ~0x10;
		new_header[3] = edsa_header[3];

		/*
		 * Move CFI bit from its place in the DSA header to
		 * its 802.1q-designated place.
		 */
		if (edsa_header[1] & 0x01)
			new_header[2] |= 0x10;

		skb_pull_rcsum(skb, DSA_HLEN);

		/*
		 * Update packet checksum if skb is CHECKSUM_COMPLETE.
		 */
		if (skb->ip_summed == CHECKSUM_COMPLETE) {
			__wsum c = skb->csum;
			c = csum_add(c, csum_partial(new_header + 2, 2, 0));
			c = csum_sub(c, csum_partial(edsa_header + 2, 2, 0));
			skb->csum = c;
		}

		memcpy(edsa_header, new_header, DSA_HLEN);

		memmove(skb->data - ETH_HLEN,
			skb->data - ETH_HLEN - DSA_HLEN,
			2 * ETH_ALEN);
	} else {
		/*
		 * Remove DSA tag and update checksum.
		 */
		skb_pull_rcsum(skb, EDSA_HLEN);
		memmove(skb->data - ETH_HLEN,
			skb->data - ETH_HLEN - EDSA_HLEN,
			2 * ETH_ALEN);
	}

	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 edsa_packet_type = {
	.type	= __constant_htons(ETH_P_EDSA),
	.func	= edsa_rcv,
};

static int __init edsa_init_module(void)
{
	dev_add_pack(&edsa_packet_type);
	return 0;
}
module_init(edsa_init_module);

static void __exit edsa_cleanup_module(void)
{
	dev_remove_pack(&edsa_packet_type);
}
module_exit(edsa_cleanup_module);
Commit	Line	Data
91da11f8 LB	1	/*
	2	* net/dsa/tag_edsa.c - Ethertype DSA tagging
	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	#define DSA_HLEN 4
	17	#define EDSA_HLEN 8
	18
	19	int edsa_xmit(struct sk_buff skb, struct net_device dev)
	20	{
	21	struct dsa_slave_priv *p = netdev_priv(dev);
	22	u8 *edsa_header;
	23
	24	dev->stats.tx_packets++;
	25	dev->stats.tx_bytes += skb->len;
	26
	27	/*
	28	* Convert the outermost 802.1q tag to a DSA tag and prepend
	29	* a DSA ethertype field is the packet is tagged, or insert
	30	* a DSA ethertype plus DSA tag between the addresses and the
	31	* current ethertype field if the packet is untagged.
	32	*/
	33	if (skb->protocol == htons(ETH_P_8021Q)) {
	34	if (skb_cow_head(skb, DSA_HLEN) < 0)
	35	goto out_free;
	36	skb_push(skb, DSA_HLEN);
	37
	38	memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN);
	39
	40	/*
	41	* Construct tagged FROM_CPU DSA tag from 802.1q tag.
	42	*/
	43	edsa_header = skb->data + 2 * ETH_ALEN;
	44	edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff;
	45	edsa_header[1] = ETH_P_EDSA & 0xff;
	46	edsa_header[2] = 0x00;
	47	edsa_header[3] = 0x00;
	48	edsa_header[4] = 0x60;
	49	edsa_header[5] = p->port << 3;
	50
	51	/*
	52	* Move CFI field from byte 6 to byte 5.
	53	*/
	54	if (edsa_header[6] & 0x10) {
	55	edsa_header[5] \|= 0x01;
	56	edsa_header[6] &= ~0x10;
	57	}
	58	} else {
	59	if (skb_cow_head(skb, EDSA_HLEN) < 0)
	60	goto out_free;
	61	skb_push(skb, EDSA_HLEN);
	62
	63	memmove(skb->data, skb->data + EDSA_HLEN, 2 * ETH_ALEN);
	64
65	/*
66	* Construct untagged FROM_CPU DSA tag.
67	*/
68	edsa_header = skb->data + 2 * ETH_ALEN;
69	edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff;
70	edsa_header[1] = ETH_P_EDSA & 0xff;
71	edsa_header[2] = 0x00;
72	edsa_header[3] = 0x00;
73	edsa_header[4] = 0x40;
74	edsa_header[5] = p->port << 3;
75	edsa_header[6] = 0x00;
76	edsa_header[7] = 0x00;
77	}
78
79	skb->protocol = htons(ETH_P_EDSA);
80
81	skb->dev = p->parent->master_netdev;
82	dev_queue_xmit(skb);
83
84	return NETDEV_TX_OK;
85
86	out_free:
87	kfree_skb(skb);
88	return NETDEV_TX_OK;
89	}
90
91	static int edsa_rcv(struct sk_buff skb, struct net_device dev,
92	struct packet_type pt, struct net_device orig_dev)
93	{
94	struct dsa_switch *ds = dev->dsa_ptr;
95	u8 *edsa_header;
96	int source_port;
97
98	if (unlikely(ds == NULL))
99	goto out_drop;
100
101	skb = skb_unshare(skb, GFP_ATOMIC);
102	if (skb == NULL)
103	goto out;
104
105	if (unlikely(!pskb_may_pull(skb, EDSA_HLEN)))
106	goto out_drop;
107
108	/*
109	* Skip the two null bytes after the ethertype.
110	*/
111	edsa_header = skb->data + 2;
112
113	/*
114	* Check that frame type is either TO_CPU or FORWARD, and
115	* that the source device is zero.
116	*/
117	if ((edsa_header[0] & 0xdf) != 0x00 && (edsa_header[0] & 0xdf) != 0xc0)
118	goto out_drop;
119
120	/*
121	* Check that the source port is a registered DSA port.
122	*/
123	source_port = (edsa_header[1] >> 3) & 0x1f;
124	if (source_port >= DSA_MAX_PORTS \|\| ds->ports[source_port] == NULL)
125	goto out_drop;
126
127	/*
128	* If the 'tagged' bit is set, convert the DSA tag to a 802.1q
129	* tag and delete the ethertype part. If the 'tagged' bit is
130	* clear, delete the ethertype and the DSA tag parts.
131	*/
132	if (edsa_header[0] & 0x20) {
133	u8 new_header[4];
134
135	/*
136	* Insert 802.1q ethertype and copy the VLAN-related
137	* fields, but clear the bit that will hold CFI (since
138	* DSA uses that bit location for another purpose).
139	*/
140	new_header[0] = (ETH_P_8021Q >> 8) & 0xff;
141	new_header[1] = ETH_P_8021Q & 0xff;
142	new_header[2] = edsa_header[2] & ~0x10;
143	new_header[3] = edsa_header[3];
144
145	/*
146	* Move CFI bit from its place in the DSA header to
147	* its 802.1q-designated place.
148	*/
149	if (edsa_header[1] & 0x01)
150	new_header[2] \|= 0x10;
151
152	skb_pull_rcsum(skb, DSA_HLEN);
153
154	/*
155	* Update packet checksum if skb is CHECKSUM_COMPLETE.
156	*/
157	if (skb->ip_summed == CHECKSUM_COMPLETE) {
158	__wsum c = skb->csum;
159	c = csum_add(c, csum_partial(new_header + 2, 2, 0));
160	c = csum_sub(c, csum_partial(edsa_header + 2, 2, 0));
161	skb->csum = c;
162	}
163
164	memcpy(edsa_header, new_header, DSA_HLEN);
165
166	memmove(skb->data - ETH_HLEN,
167	skb->data - ETH_HLEN - DSA_HLEN,
168	2 * ETH_ALEN);
169	} else {
170	/*
171	* Remove DSA tag and update checksum.
172	*/
173	skb_pull_rcsum(skb, EDSA_HLEN);
174	memmove(skb->data - ETH_HLEN,
175	skb->data - ETH_HLEN - EDSA_HLEN,
176	2 * ETH_ALEN);
177	}
178
179	skb->dev = ds->ports[source_port];
180	skb_push(skb, ETH_HLEN);
14ee6742	181	skb->pkt_type = PACKET_HOST;
91da11f8 LB	182	skb->protocol = eth_type_trans(skb, skb->dev);
91da11f8 LB	183
91da11f8 LB	184	skb->dev->stats.rx_packets++;
	185	skb->dev->stats.rx_bytes += skb->len;
	186
	187	netif_receive_skb(skb);
	188
	189	return 0;
	190
	191	out_drop:
	192	kfree_skb(skb);
	193	out:
	194	return 0;
	195	}
	196
	197	static struct packet_type edsa_packet_type = {
	198	.type = __constant_htons(ETH_P_EDSA),
	199	.func = edsa_rcv,
	200	};
	201
	202	static int __init edsa_init_module(void)
	203	{
	204	dev_add_pack(&edsa_packet_type);
	205	return 0;
	206	}
	207	module_init(edsa_init_module);
	208
	209	static void __exit edsa_cleanup_module(void)
	210	{
	211	dev_remove_pack(&edsa_packet_type);
	212	}
	213	module_exit(edsa_cleanup_module);