[linux.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/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"


static void rx(struct net_device *dev, int bufnum,
	       struct archdr *pkthdr, int length);
static int build_header(struct sk_buff *skb,
			struct net_device *dev,
			unsigned short type,
			uint8_t daddr);
static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
		      int bufnum);
static int ack_tx(struct net_device *dev, int acked);


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;
}


#ifdef MODULE

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");
#endif				/* MODULE */


/* 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");
		lp->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 = __constant_htons(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 = __constant_htons(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;
}
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>
	30	#include <linux/init.h>
	31	#include <linux/if_arp.h>
	32	#include <net/arp.h>
	33	#include <linux/netdevice.h>
	34	#include <linux/skbuff.h>
	35	#include <linux/arcdevice.h>
	36
	37	#define VERSION "arcnet: cap mode (`c') encapsulation support loaded.\n"
	38
	39
	40	static void rx(struct net_device *dev, int bufnum,
	41	struct archdr *pkthdr, int length);
	42	static int build_header(struct sk_buff *skb,
	43	struct net_device *dev,
	44	unsigned short type,
	45	uint8_t daddr);
	46	static int prepare_tx(struct net_device dev, struct archdr pkt, int length,
	47	int bufnum);
	48	static int ack_tx(struct net_device *dev, int acked);
	49
	50
75c96f85	51	static struct ArcProto capmode_proto =
1da177e4 LT	52	{
	53	'r',
	54	XMTU,
	55	0,
	56	rx,
	57	build_header,
	58	prepare_tx,
	59	NULL,
	60	ack_tx
	61	};
	62
	63
888432f6	64	static void arcnet_cap_init(void)
1da177e4 LT	65	{
	66	int count;
	67
	68	for (count = 1; count <= 8; count++)
	69	if (arc_proto_map[count] == arc_proto_default)
	70	arc_proto_map[count] = &capmode_proto;
	71
	72	/* for cap mode, we only set the bcast proto if there's no better one */
	73	if (arc_bcast_proto == arc_proto_default)
	74	arc_bcast_proto = &capmode_proto;
	75
	76	arc_proto_default = &capmode_proto;
	77	arc_raw_proto = &capmode_proto;
	78	}
	79
	80
	81	#ifdef MODULE
	82
7249d4c3	83	static int __init capmode_module_init(void)
1da177e4 LT	84	{
	85	printk(VERSION);
	86	arcnet_cap_init();
	87	return 0;
	88	}
	89
7249d4c3	90	static void __exit capmode_module_exit(void)
1da177e4 LT	91	{
	92	arcnet_unregister_proto(&capmode_proto);
	93	}
7249d4c3 JS	94	module_init(capmode_module_init);
7249d4c3 JS	95	module_exit(capmode_module_exit);
1da177e4 LT	96
	97	MODULE_LICENSE("GPL");
	98	#endif /* MODULE */
	99
	100
	101
	102	/* packet receiver */
	103	static void rx(struct net_device *dev, int bufnum,
	104	struct archdr *pkthdr, int length)
	105	{
454d7c9b	106	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	107	struct sk_buff *skb;
	108	struct archdr *pkt = pkthdr;
	109	char pktbuf, pkthdrbuf;
	110	int ofs;
	111
	112	BUGMSG(D_DURING, "it's a raw(cap) packet (length=%d)\n", length);
	113
	114	if (length >= MinTU)
	115	ofs = 512 - length;
	116	else
	117	ofs = 256 - length;
	118
	119	skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), GFP_ATOMIC);
	120	if (skb == NULL) {
	121	BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
	122	lp->stats.rx_dropped++;
	123	return;
	124	}
	125	skb_put(skb, length + ARC_HDR_SIZE + sizeof(int));
	126	skb->dev = dev;
459a98ed	127	skb_reset_mac_header(skb);
98e399f8	128	pkt = (struct archdr *)skb_mac_header(skb);
1da177e4 LT	129	skb_pull(skb, ARC_HDR_SIZE);
	130
	131	/* up to sizeof(pkt->soft) has already been copied from the card */
	132	/* squeeze in an int for the cap encapsulation */
	133
	134	/* use these variables to be sure we count in bytes, not in
	135	sizeof(struct archdr) */
	136	pktbuf=(char*)pkt;
	137	pkthdrbuf=(char*)pkthdr;
	138	memcpy(pktbuf, pkthdrbuf, ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto));
	139	memcpy(pktbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto)+sizeof(int),
	140	pkthdrbuf+ARC_HDR_SIZE+sizeof(pkt->soft.cap.proto),
	141	sizeof(struct archdr)-ARC_HDR_SIZE-sizeof(pkt->soft.cap.proto));
	142
	143	if (length > sizeof(pkt->soft))
	144	lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
	145	pkt->soft.raw + sizeof(pkt->soft)
	146	+ sizeof(int),
	147	length - sizeof(pkt->soft));
	148
	149	BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
	150
	151	skb->protocol = __constant_htons(ETH_P_ARCNET);
	152	;
	153	netif_rx(skb);
1da177e4 LT	154	}
	155
	156
	157	/*
	158	* Create the ARCnet hard/soft headers for cap mode.
	159	* There aren't any soft headers in cap mode - not even the protocol id.
	160	*/
	161	static int build_header(struct sk_buff *skb,
	162	struct net_device *dev,
	163	unsigned short type,
	164	uint8_t daddr)
	165	{
	166	int hdr_size = ARC_HDR_SIZE;
	167	struct archdr pkt = (struct archdr ) skb_push(skb, hdr_size);
	168
	169	BUGMSG(D_PROTO, "Preparing header for cap packet %x.\n",
	170	((int)&pkt->soft.cap.cookie[0]));
	171	/*
	172	* Set the source hardware address.
	173	*
	174	* This is pretty pointless for most purposes, but it can help in
	175	* debugging. ARCnet does not allow us to change the source address in
	176	* the actual packet sent)
	177	*/
	178	pkt->hard.source = *dev->dev_addr;
	179
	180	/* see linux/net/ethernet/eth.c to see where I got the following */
	181
	182	if (dev->flags & (IFF_LOOPBACK \| IFF_NOARP)) {
	183	/*
	184	* FIXME: fill in the last byte of the dest ipaddr here to better
	185	* comply with RFC1051 in "noarp" mode.
	186	*/
	187	pkt->hard.dest = 0;
	188	return hdr_size;
	189	}
	190	/* otherwise, just fill it in and go! */
	191	pkt->hard.dest = daddr;
	192
	193	return hdr_size; /* success */
	194	}
	195
	196
	197	static int prepare_tx(struct net_device dev, struct archdr pkt, int length,
	198	int bufnum)
	199	{
454d7c9b	200	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	201	struct arc_hardware *hard = &pkt->hard;
	202	int ofs;
	203
	204
	205	/* hard header is not included in packet length */
	206	length -= ARC_HDR_SIZE;
	207	/* And neither is the cookie field */
	208	length -= sizeof(int);
	209
	210	BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
	211	lp->next_tx, lp->cur_tx, bufnum);
	212
	213	BUGMSG(D_PROTO, "Sending for cap packet %x.\n",
	214	((int)&pkt->soft.cap.cookie[0]));
	215
	216	if (length > XMTU) {
	217	/* should never happen! other people already check for this. */
	218	BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n",
	219	length, XMTU);
	220	length = XMTU;
	221	}
	222	if (length > MinTU) {
	223	hard->offset[0] = 0;
	224	hard->offset[1] = ofs = 512 - length;
	225	} else if (length > MTU) {
	226	hard->offset[0] = 0;
	227	hard->offset[1] = ofs = 512 - length - 3;
	228	} else
	229	hard->offset[0] = ofs = 256 - length;
	230
	231	BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n",
	232	length,ofs);
	233
	234	// Copy the arcnet-header + the protocol byte down:
	235	lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
	236	lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft.cap.proto,
	237	sizeof(pkt->soft.cap.proto));
	238
	239	// Skip the extra integer we have written into it as a cookie
	240	// but write the rest of the message:
	241	lp->hw.copy_to_card(dev, bufnum, ofs+1,
	242	((unsigned char*)&pkt->soft.cap.mes),length-1);
	243
	244	lp->lastload_dest = hard->dest;
	245
	246	return 1; /* done */
	247	}
	248
	249
	250	static int ack_tx(struct net_device *dev, int acked)
	251	{
454d7c9b	252	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	253	struct sk_buff *ackskb;
	254	struct archdr *ackpkt;
	255	int length=sizeof(struct arc_cap);
	256
	257	BUGMSG(D_DURING, "capmode: ack_tx: protocol: %x: result: %d\n",
	258	lp->outgoing.skb->protocol, acked);
	259
	260	BUGLVL(D_SKB) arcnet_dump_skb(dev, lp->outgoing.skb, "ack_tx");
	261
	262	/* Now alloc a skb to send back up through the layers: */
	263	ackskb = alloc_skb(length + ARC_HDR_SIZE , GFP_ATOMIC);
	264	if (ackskb == NULL) {
	265	BUGMSG(D_NORMAL, "Memory squeeze, can't acknowledge.\n");
	266	goto free_outskb;
	267	}
	268
	269	skb_put(ackskb, length + ARC_HDR_SIZE );
	270	ackskb->dev = dev;
	271
459a98ed	272	skb_reset_mac_header(ackskb);
98e399f8	273	ackpkt = (struct archdr *)skb_mac_header(ackskb);
1da177e4 LT	274	/* skb_pull(ackskb, ARC_HDR_SIZE); */
	275
	276
d626f62b ACM	277	skb_copy_from_linear_data(lp->outgoing.skb, ackpkt,
d626f62b ACM	278	ARC_HDR_SIZE + sizeof(struct arc_cap));
1da177e4 LT	279	ackpkt->soft.cap.proto=0; /* using protocol 0 for acknowledge */
	280	ackpkt->soft.cap.mes.ack=acked;
	281
	282	BUGMSG(D_PROTO, "Ackknowledge for cap packet %x.\n",
	283	((int)&ackpkt->soft.cap.cookie[0]));
	284
	285	ackskb->protocol = __constant_htons(ETH_P_ARCNET);
	286
	287	BUGLVL(D_SKB) arcnet_dump_skb(dev, ackskb, "ack_tx_recv");
	288	netif_rx(ackskb);
	289
	290	free_outskb:
	291	dev_kfree_skb_irq(lp->outgoing.skb);
	292	lp->outgoing.proto = NULL; /* We are always finished when in this protocol */
	293
	294	return 0;
	295	}