[net-next-2.6.git] / drivers / net / arcnet / capmode.c

/*
 * Linux ARCnet driver - "cap mode" packet encapsulation.
 * It adds sequence numbers to packets for communicating between a user space
 * application and the driver. After a transmit it sends a packet with protocol
 * byte 0 back up to the userspace containing the sequence number of the packet
 * plus the transmit-status on the ArcNet.
 *
 * Written 2002-4 by Esben Nielsen, Vestas Wind Systems A/S
 * Derived from arc-rawmode.c by Avery Pennarun.
 * arc-rawmode was in turned based on skeleton.c, see below.
 *
 * **********************
 *
 * The original copyright of skeleton.c was as follows:
 *
 * skeleton.c Written 1993 by Donald Becker.
 * Copyright 1993 United States Government as represented by the
 * Director, National Security Agency.  This software may only be used
 * and distributed according to the terms of the GNU General Public License as
 * modified by SRC, incorporated herein by reference.
 *
 * **********************
 *
 * For more details, see drivers/net/arcnet.c
 *
 * **********************
 */

#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/if_arp.h>
#include <net/arp.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/arcdevice.h>

#define VERSION "arcnet: cap mode (`c') encapsulation support loaded.\n"

/* packet receiver */
static void rx(struct net_device *dev, int bufnum,
	       struct archdr *pkthdr, int length)
{
	struct arcnet_local *lp = netdev_priv(dev);
	struct sk_buff *skb;
	struct archdr *pkt = pkthdr;
	char *pktbuf, *pkthdrbuf;
	int ofs;

	BUGMSG(D_DURING, "it's a raw(cap) packet (length=%d)\n", length);

	if (length >= MinTU)
		ofs = 512 - length;
	else
		ofs = 256 - length;

	skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), GFP_ATOMIC);
	if (skb == NULL) {
		BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
		dev->stats.rx_dropped++;
		return;
	}
	skb_put(skb, length + ARC_HDR_SIZE + sizeof(int));
	skb->dev = dev;
	skb_reset_mac_header(skb);
	pkt = (struct archdr *)skb_mac_header(skb);
	skb_pull(skb, ARC_HDR_SIZE);

	/* up to sizeof(pkt->soft) has already been copied from the card */
	/* squeeze in an int for the cap encapsulation */

	/* use these variables to be sure we count in bytes, not in
	   sizeof(struct archdr) */
	pktbuf=(char*)pkt;
	pkthdrbuf=(char*)pkthdr;
	memcpy(pktbuf, pkthdrbuf, ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto));
	memcpy(pktbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto)+sizeof(int),
	       pkthdrbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto),
	       sizeof(struct archdr)-ARC_HDR_SIZE-sizeof(pkt->soft.cap.proto));

	if (length > sizeof(pkt->soft))
		lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
				      pkt->soft.raw + sizeof(pkt->soft)
				      + sizeof(int),
				      length - sizeof(pkt->soft));

	BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");

	skb->protocol = cpu_to_be16(ETH_P_ARCNET);
	netif_rx(skb);
}


/*
 * Create the ARCnet hard/soft headers for cap mode.
 * There aren't any soft headers in cap mode - not even the protocol id.
 */
static int build_header(struct sk_buff *skb,
			struct net_device *dev,
			unsigned short type,
			uint8_t daddr)
{
	int hdr_size = ARC_HDR_SIZE;
	struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);

	BUGMSG(D_PROTO, "Preparing header for cap packet %x.\n",
	       *((int*)&pkt->soft.cap.cookie[0]));
	/*
	 * Set the source hardware address.
	 *
	 * This is pretty pointless for most purposes, but it can help in
	 * debugging.  ARCnet does not allow us to change the source address in
	 * the actual packet sent)
	 */
	pkt->hard.source = *dev->dev_addr;

	/* see linux/net/ethernet/eth.c to see where I got the following */

	if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
		/*
		 * FIXME: fill in the last byte of the dest ipaddr here to better
		 * comply with RFC1051 in "noarp" mode.
		 */
		pkt->hard.dest = 0;
		return hdr_size;
	}
	/* otherwise, just fill it in and go! */
	pkt->hard.dest = daddr;

	return hdr_size;	/* success */
}


static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
		      int bufnum)
{
	struct arcnet_local *lp = netdev_priv(dev);
	struct arc_hardware *hard = &pkt->hard;
	int ofs;


	/* hard header is not included in packet length */
	length -= ARC_HDR_SIZE;
	/* And neither is the cookie field */
	length -= sizeof(int);

	BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
	       lp->next_tx, lp->cur_tx, bufnum);

	BUGMSG(D_PROTO, "Sending for cap packet %x.\n",
	       *((int*)&pkt->soft.cap.cookie[0]));

	if (length > XMTU) {
		/* should never happen! other people already check for this. */
		BUGMSG(D_NORMAL, "Bug!  prepare_tx with size %d (> %d)\n",
		       length, XMTU);
		length = XMTU;
	}
	if (length > MinTU) {
		hard->offset[0] = 0;
		hard->offset[1] = ofs = 512 - length;
	} else if (length > MTU) {
		hard->offset[0] = 0;
		hard->offset[1] = ofs = 512 - length - 3;
	} else
		hard->offset[0] = ofs = 256 - length;

	BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n",
	       length,ofs);

	/* Copy the arcnet-header + the protocol byte down: */
	lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
	lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft.cap.proto,
			    sizeof(pkt->soft.cap.proto));

	/* Skip the extra integer we have written into it as a cookie
	   but write the rest of the message: */
	lp->hw.copy_to_card(dev, bufnum, ofs+1,
			    ((unsigned char*)&pkt->soft.cap.mes),length-1);

	lp->lastload_dest = hard->dest;

	return 1;	/* done */
}

static int ack_tx(struct net_device *dev, int acked)
{
	struct arcnet_local *lp = netdev_priv(dev);
	struct sk_buff *ackskb;
	struct archdr *ackpkt;
	int length=sizeof(struct arc_cap);

	BUGMSG(D_DURING, "capmode: ack_tx: protocol: %x: result: %d\n",
		lp->outgoing.skb->protocol, acked);

	BUGLVL(D_SKB) arcnet_dump_skb(dev, lp->outgoing.skb, "ack_tx");

	/* Now alloc a skb to send back up through the layers: */
	ackskb = alloc_skb(length + ARC_HDR_SIZE , GFP_ATOMIC);
	if (ackskb == NULL) {
		BUGMSG(D_NORMAL, "Memory squeeze, can't acknowledge.\n");
		goto free_outskb;
	}

	skb_put(ackskb, length + ARC_HDR_SIZE );
	ackskb->dev = dev;

	skb_reset_mac_header(ackskb);
	ackpkt = (struct archdr *)skb_mac_header(ackskb);
	/* skb_pull(ackskb, ARC_HDR_SIZE); */

	skb_copy_from_linear_data(lp->outgoing.skb, ackpkt,
				  ARC_HDR_SIZE + sizeof(struct arc_cap));
	ackpkt->soft.cap.proto = 0; /* using protocol 0 for acknowledge */
	ackpkt->soft.cap.mes.ack=acked;

	BUGMSG(D_PROTO, "Ackknowledge for cap packet %x.\n",
			*((int*)&ackpkt->soft.cap.cookie[0]));

	ackskb->protocol = cpu_to_be16(ETH_P_ARCNET);

	BUGLVL(D_SKB) arcnet_dump_skb(dev, ackskb, "ack_tx_recv");
	netif_rx(ackskb);

free_outskb:
	dev_kfree_skb_irq(lp->outgoing.skb);
	lp->outgoing.proto = NULL; /* We are always finished when in this protocol */

	return 0;
}

static struct ArcProto capmode_proto =
{
	'r',
	XMTU,
	0,
	rx,
	build_header,
	prepare_tx,
	NULL,
	ack_tx
};

static void arcnet_cap_init(void)
{
	int count;

	for (count = 1; count <= 8; count++)
		if (arc_proto_map[count] == arc_proto_default)
			arc_proto_map[count] = &capmode_proto;

	/* for cap mode, we only set the bcast proto if there's no better one */
	if (arc_bcast_proto == arc_proto_default)
		arc_bcast_proto = &capmode_proto;

	arc_proto_default = &capmode_proto;
	arc_raw_proto = &capmode_proto;
}

static int __init capmode_module_init(void)
{
	printk(VERSION);
	arcnet_cap_init();
	return 0;
}

static void __exit capmode_module_exit(void)
{
	arcnet_unregister_proto(&capmode_proto);
}
module_init(capmode_module_init);
module_exit(capmode_module_exit);

MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Linux ARCnet driver - "cap mode" packet encapsulation.
	3	* It adds sequence numbers to packets for communicating between a user space
	4	* application and the driver. After a transmit it sends a packet with protocol
	5	* byte 0 back up to the userspace containing the sequence number of the packet
	6	* plus the transmit-status on the ArcNet.
	7	*
	8	* Written 2002-4 by Esben Nielsen, Vestas Wind Systems A/S
	9	* Derived from arc-rawmode.c by Avery Pennarun.
	10	* arc-rawmode was in turned based on skeleton.c, see below.
	11	*
	12	* **********************
	13	*
	14	* The original copyright of skeleton.c was as follows:
	15	*
	16	* skeleton.c Written 1993 by Donald Becker.
	17	* Copyright 1993 United States Government as represented by the
	18	* Director, National Security Agency. This software may only be used
	19	* and distributed according to the terms of the GNU General Public License as
	20	* modified by SRC, incorporated herein by reference.
	21	*
	22	* **********************
	23	*
	24	* For more details, see drivers/net/arcnet.c
	25	*
	26	* **********************
	27	*/
	28
	29	#include <linux/module.h>
5a0e3ad6	30	#include <linux/gfp.h>
1da177e4 LT	31	#include <linux/init.h>
	32	#include <linux/if_arp.h>
	33	#include <net/arp.h>
	34	#include <linux/netdevice.h>
	35	#include <linux/skbuff.h>
	36	#include <linux/arcdevice.h>
	37
	38	#define VERSION "arcnet: cap mode (`c') encapsulation support loaded.\n"
	39
1da177e4 LT	40	/* packet receiver */
	41	static void rx(struct net_device *dev, int bufnum,
	42	struct archdr *pkthdr, int length)
	43	{
454d7c9b	44	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	45	struct sk_buff *skb;
	46	struct archdr *pkt = pkthdr;
	47	char pktbuf, pkthdrbuf;
	48	int ofs;
	49
	50	BUGMSG(D_DURING, "it's a raw(cap) packet (length=%d)\n", length);
	51
	52	if (length >= MinTU)
	53	ofs = 512 - length;
	54	else
	55	ofs = 256 - length;
	56
	57	skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), GFP_ATOMIC);
	58	if (skb == NULL) {
	59	BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
5803c512	60	dev->stats.rx_dropped++;
1da177e4 LT	61	return;
	62	}
	63	skb_put(skb, length + ARC_HDR_SIZE + sizeof(int));
	64	skb->dev = dev;
459a98ed	65	skb_reset_mac_header(skb);
98e399f8	66	pkt = (struct archdr *)skb_mac_header(skb);
1da177e4 LT	67	skb_pull(skb, ARC_HDR_SIZE);
	68
	69	/* up to sizeof(pkt->soft) has already been copied from the card */
	70	/* squeeze in an int for the cap encapsulation */
	71
	72	/* use these variables to be sure we count in bytes, not in
	73	sizeof(struct archdr) */
	74	pktbuf=(char*)pkt;
	75	pkthdrbuf=(char*)pkthdr;
	76	memcpy(pktbuf, pkthdrbuf, ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto));
	77	memcpy(pktbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto)+sizeof(int),
	78	pkthdrbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto),
	79	sizeof(struct archdr)-ARC_HDR_SIZE-sizeof(pkt->soft.cap.proto));
	80
	81	if (length > sizeof(pkt->soft))
	82	lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
	83	pkt->soft.raw + sizeof(pkt->soft)
	84	+ sizeof(int),
	85	length - sizeof(pkt->soft));
	86
	87	BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
	88
09640e63	89	skb->protocol = cpu_to_be16(ETH_P_ARCNET);
1da177e4	90	netif_rx(skb);
1da177e4 LT	91	}
	92
	93
	94	/*
	95	* Create the ARCnet hard/soft headers for cap mode.
	96	* There aren't any soft headers in cap mode - not even the protocol id.
	97	*/
	98	static int build_header(struct sk_buff *skb,
	99	struct net_device *dev,
	100	unsigned short type,
	101	uint8_t daddr)
	102	{
	103	int hdr_size = ARC_HDR_SIZE;
	104	struct archdr pkt = (struct archdr ) skb_push(skb, hdr_size);
	105
	106	BUGMSG(D_PROTO, "Preparing header for cap packet %x.\n",
	107	((int)&pkt->soft.cap.cookie[0]));
	108	/*
	109	* Set the source hardware address.
	110	*
	111	* This is pretty pointless for most purposes, but it can help in
	112	* debugging. ARCnet does not allow us to change the source address in
	113	* the actual packet sent)
	114	*/
	115	pkt->hard.source = *dev->dev_addr;
	116
	117	/* see linux/net/ethernet/eth.c to see where I got the following */
	118
	119	if (dev->flags & (IFF_LOOPBACK \| IFF_NOARP)) {
	120	/*
	121	* FIXME: fill in the last byte of the dest ipaddr here to better
	122	* comply with RFC1051 in "noarp" mode.
	123	*/
	124	pkt->hard.dest = 0;
	125	return hdr_size;
	126	}
	127	/* otherwise, just fill it in and go! */
	128	pkt->hard.dest = daddr;
	129
	130	return hdr_size; /* success */
	131	}
	132
	133
	134	static int prepare_tx(struct net_device dev, struct archdr pkt, int length,
	135	int bufnum)
	136	{
454d7c9b	137	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	138	struct arc_hardware *hard = &pkt->hard;
	139	int ofs;
	140
	141
	142	/* hard header is not included in packet length */
	143	length -= ARC_HDR_SIZE;
	144	/* And neither is the cookie field */
	145	length -= sizeof(int);
	146
	147	BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
	148	lp->next_tx, lp->cur_tx, bufnum);
	149
	150	BUGMSG(D_PROTO, "Sending for cap packet %x.\n",
	151	((int)&pkt->soft.cap.cookie[0]));
	152
	153	if (length > XMTU) {
	154	/* should never happen! other people already check for this. */
	155	BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n",
	156	length, XMTU);
	157	length = XMTU;
	158	}
	159	if (length > MinTU) {
	160	hard->offset[0] = 0;
	161	hard->offset[1] = ofs = 512 - length;
	162	} else if (length > MTU) {
	163	hard->offset[0] = 0;
	164	hard->offset[1] = ofs = 512 - length - 3;
	165	} else
	166	hard->offset[0] = ofs = 256 - length;
	167
	168	BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n",
	169	length,ofs);
	170
0da529a7	171	/* Copy the arcnet-header + the protocol byte down: */
1da177e4 LT	172	lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
	173	lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft.cap.proto,
	174	sizeof(pkt->soft.cap.proto));
	175
0da529a7 DM	176	/* Skip the extra integer we have written into it as a cookie
0da529a7 DM	177	but write the rest of the message: */
1da177e4 LT	178	lp->hw.copy_to_card(dev, bufnum, ofs+1,
	179	((unsigned char*)&pkt->soft.cap.mes),length-1);
	180
	181	lp->lastload_dest = hard->dest;
	182
0da529a7	183	return 1; /* done */
1da177e4 LT	184	}
1da177e4 LT	185
1da177e4 LT	186	static int ack_tx(struct net_device *dev, int acked)
1da177e4 LT	187	{
0da529a7 DM	188	struct arcnet_local *lp = netdev_priv(dev);
	189	struct sk_buff *ackskb;
	190	struct archdr *ackpkt;
	191	int length=sizeof(struct arc_cap);
1da177e4	192
0da529a7 DM	193	BUGMSG(D_DURING, "capmode: ack_tx: protocol: %x: result: %d\n",
0da529a7 DM	194	lp->outgoing.skb->protocol, acked);
1da177e4	195
0da529a7	196	BUGLVL(D_SKB) arcnet_dump_skb(dev, lp->outgoing.skb, "ack_tx");
1da177e4	197
0da529a7 DM	198	/* Now alloc a skb to send back up through the layers: */
	199	ackskb = alloc_skb(length + ARC_HDR_SIZE , GFP_ATOMIC);
	200	if (ackskb == NULL) {
	201	BUGMSG(D_NORMAL, "Memory squeeze, can't acknowledge.\n");
	202	goto free_outskb;
	203	}
	204
	205	skb_put(ackskb, length + ARC_HDR_SIZE );
	206	ackskb->dev = dev;
	207
	208	skb_reset_mac_header(ackskb);
	209	ackpkt = (struct archdr *)skb_mac_header(ackskb);
	210	/* skb_pull(ackskb, ARC_HDR_SIZE); */
1da177e4	211
0da529a7 DM	212	skb_copy_from_linear_data(lp->outgoing.skb, ackpkt,
	213	ARC_HDR_SIZE + sizeof(struct arc_cap));
	214	ackpkt->soft.cap.proto = 0; /* using protocol 0 for acknowledge */
	215	ackpkt->soft.cap.mes.ack=acked;
1da177e4	216
0da529a7 DM	217	BUGMSG(D_PROTO, "Ackknowledge for cap packet %x.\n",
0da529a7 DM	218	((int)&ackpkt->soft.cap.cookie[0]));
1da177e4	219
0da529a7	220	ackskb->protocol = cpu_to_be16(ETH_P_ARCNET);
1da177e4	221
0da529a7 DM	222	BUGLVL(D_SKB) arcnet_dump_skb(dev, ackskb, "ack_tx_recv");
0da529a7 DM	223	netif_rx(ackskb);
1da177e4	224
0da529a7 DM	225	free_outskb:
	226	dev_kfree_skb_irq(lp->outgoing.skb);
	227	lp->outgoing.proto = NULL; /* We are always finished when in this protocol */
1da177e4	228
0da529a7 DM	229	return 0;
0da529a7 DM	230	}
1da177e4	231
0da529a7 DM	232	static struct ArcProto capmode_proto =
	233	{
	234	'r',
	235	XMTU,
	236	0,
	237	rx,
	238	build_header,
	239	prepare_tx,
	240	NULL,
	241	ack_tx
	242	};
1da177e4	243
0da529a7 DM	244	static void arcnet_cap_init(void)
	245	{
	246	int count;
1da177e4	247
0da529a7 DM	248	for (count = 1; count <= 8; count++)
	249	if (arc_proto_map[count] == arc_proto_default)
	250	arc_proto_map[count] = &capmode_proto;
	251
	252	/* for cap mode, we only set the bcast proto if there's no better one */
	253	if (arc_bcast_proto == arc_proto_default)
	254	arc_bcast_proto = &capmode_proto;
	255
	256	arc_proto_default = &capmode_proto;
	257	arc_raw_proto = &capmode_proto;
1da177e4	258	}
0da529a7 DM	259
	260	static int __init capmode_module_init(void)
	261	{
	262	printk(VERSION);
	263	arcnet_cap_init();
	264	return 0;
	265	}
	266
	267	static void __exit capmode_module_exit(void)
	268	{
	269	arcnet_unregister_proto(&capmode_proto);
	270	}
	271	module_init(capmode_module_init);
	272	module_exit(capmode_module_exit);
	273
	274	MODULE_LICENSE("GPL");