[linux-block.git] / drivers / net / arcnet / rfc1051.c

/*
 * Linux ARCnet driver - RFC1051 ("simple" standard) packet encapsulation
 *
 * Written 1994-1999 by Avery Pennarun.
 * Derived from skeleton.c by Donald Becker.
 *
 * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
 *  for sponsoring the further development of this driver.
 *
 * **********************
 *
 * 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
 *
 * **********************
 */

#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt

#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 "arcdevice.h"

static __be16 type_trans(struct sk_buff *skb, struct net_device *dev);
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 struct ArcProto rfc1051_proto = {
	.suffix		= 's',
	.mtu		= XMTU - RFC1051_HDR_SIZE,
	.is_ip          = 1,
	.rx		= rx,
	.build_header	= build_header,
	.prepare_tx	= prepare_tx,
	.continue_tx    = NULL,
	.ack_tx         = NULL
};

static int __init arcnet_rfc1051_init(void)
{
	pr_info("%s\n", "RFC1051 \"simple standard\" (`s') encapsulation support loaded");

	arc_proto_map[ARC_P_IP_RFC1051]
	    = arc_proto_map[ARC_P_ARP_RFC1051]
	    = &rfc1051_proto;

	/* if someone else already owns the broadcast, we won't take it */
	if (arc_bcast_proto == arc_proto_default)
		arc_bcast_proto = &rfc1051_proto;

	return 0;
}

static void __exit arcnet_rfc1051_exit(void)
{
	arcnet_unregister_proto(&rfc1051_proto);
}

module_init(arcnet_rfc1051_init);
module_exit(arcnet_rfc1051_exit);

MODULE_DESCRIPTION("ARCNet packet format (RFC 1051) module");
MODULE_LICENSE("GPL");

/* Determine a packet's protocol ID.
 *
 * With ARCnet we have to convert everything to Ethernet-style stuff.
 */
static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
{
	struct archdr *pkt = (struct archdr *)skb->data;
	struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
	int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;

	/* Pull off the arcnet header. */
	skb_reset_mac_header(skb);
	skb_pull(skb, hdr_size);

	if (pkt->hard.dest == 0) {
		skb->pkt_type = PACKET_BROADCAST;
	} else if (dev->flags & IFF_PROMISC) {
		/* if we're not sending to ourselves :) */
		if (pkt->hard.dest != dev->dev_addr[0])
			skb->pkt_type = PACKET_OTHERHOST;
	}
	/* now return the protocol number */
	switch (soft->proto) {
	case ARC_P_IP_RFC1051:
		return htons(ETH_P_IP);
	case ARC_P_ARP_RFC1051:
		return htons(ETH_P_ARP);

	default:
		dev->stats.rx_errors++;
		dev->stats.rx_crc_errors++;
		return 0;
	}

	return htons(ETH_P_IP);
}

/* 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;
	int ofs;

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

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

	skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
	if (!skb) {
		dev->stats.rx_dropped++;
		return;
	}
	skb_put(skb, length + ARC_HDR_SIZE);
	skb->dev = dev;

	pkt = (struct archdr *)skb->data;

	/* up to sizeof(pkt->soft) has already been copied from the card */
	memcpy(pkt, pkthdr, sizeof(struct archdr));
	if (length > sizeof(pkt->soft))
		lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
				      pkt->soft.raw + sizeof(pkt->soft),
				      length - sizeof(pkt->soft));

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

	skb->protocol = type_trans(skb, dev);
	netif_rx(skb);
}

/* Create the ARCnet hard/soft headers for RFC1051 */
static int build_header(struct sk_buff *skb, struct net_device *dev,
			unsigned short type, uint8_t daddr)
{
	int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
	struct archdr *pkt = skb_push(skb, hdr_size);
	struct arc_rfc1051 *soft = &pkt->soft.rfc1051;

	/* set the protocol ID according to RFC1051 */
	switch (type) {
	case ETH_P_IP:
		soft->proto = ARC_P_IP_RFC1051;
		break;
	case ETH_P_ARP:
		soft->proto = ARC_P_ARP_RFC1051;
		break;
	default:
		arc_printk(D_NORMAL, dev, "RFC1051: I don't understand protocol %d (%Xh)\n",
			   type, type);
		dev->stats.tx_errors++;
		dev->stats.tx_aborted_errors++;
		return 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;

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

	/* hard header is not included in packet length */
	length -= ARC_HDR_SIZE;

	if (length > XMTU) {
		/* should never happen! other people already check for this. */
		arc_printk(D_NORMAL, dev, "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;
	}

	lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
	lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);

	lp->lastload_dest = hard->dest;

	return 1;		/* done */
}
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* Linux ARCnet driver - RFC1051 ("simple" standard) packet encapsulation
cb334648	3	*
1da177e4 LT	4	* Written 1994-1999 by Avery Pennarun.
	5	* Derived from skeleton.c by Donald Becker.
	6	*
	7	* Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
	8	* for sponsoring the further development of this driver.
	9	*
	10	* **********************
	11	*
	12	* The original copyright of skeleton.c was as follows:
	13	*
	14	* skeleton.c Written 1993 by Donald Becker.
	15	* Copyright 1993 United States Government as represented by the
	16	* Director, National Security Agency. This software may only be used
	17	* and distributed according to the terms of the GNU General Public License as
	18	* modified by SRC, incorporated herein by reference.
	19	*
	20	* **********************
	21	*
	22	* For more details, see drivers/net/arcnet.c
	23	*
	24	* **********************
	25	*/
05a24b23 JP	26
	27	#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt
	28
1da177e4	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>
26c6d281 JP	36
26c6d281 JP	37	#include "arcdevice.h"
1da177e4	38
701181ac	39	static __be16 type_trans(struct sk_buff skb, struct net_device dev);
1da177e4 LT	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, struct net_device dev,
	43	unsigned short type, uint8_t daddr);
	44	static int prepare_tx(struct net_device dev, struct archdr pkt, int length,
	45	int bufnum);
	46
7f5e760c	47	static struct ArcProto rfc1051_proto = {
1da177e4 LT	48	.suffix = 's',
	49	.mtu = XMTU - RFC1051_HDR_SIZE,
	50	.is_ip = 1,
	51	.rx = rx,
	52	.build_header = build_header,
	53	.prepare_tx = prepare_tx,
	54	.continue_tx = NULL,
	55	.ack_tx = NULL
	56	};
	57
1da177e4 LT	58	static int __init arcnet_rfc1051_init(void)
1da177e4 LT	59	{
05a24b23	60	pr_info("%s\n", "RFC1051 \"simple standard\" (`s') encapsulation support loaded");
1da177e4 LT	61
	62	arc_proto_map[ARC_P_IP_RFC1051]
	63	= arc_proto_map[ARC_P_ARP_RFC1051]
	64	= &rfc1051_proto;
	65
	66	/* if someone else already owns the broadcast, we won't take it */
	67	if (arc_bcast_proto == arc_proto_default)
	68	arc_bcast_proto = &rfc1051_proto;
	69
	70	return 0;
	71	}
	72
	73	static void __exit arcnet_rfc1051_exit(void)
	74	{
	75	arcnet_unregister_proto(&rfc1051_proto);
	76	}
	77
	78	module_init(arcnet_rfc1051_init);
	79	module_exit(arcnet_rfc1051_exit);
	80
538b22e7	81	MODULE_DESCRIPTION("ARCNet packet format (RFC 1051) module");
1da177e4 LT	82	MODULE_LICENSE("GPL");
1da177e4 LT	83
f2f0a16b	84	/* Determine a packet's protocol ID.
cb334648	85	*
1da177e4 LT	86	* With ARCnet we have to convert everything to Ethernet-style stuff.
1da177e4 LT	87	*/
701181ac	88	static __be16 type_trans(struct sk_buff skb, struct net_device dev)
1da177e4	89	{
cb334648	90	struct archdr pkt = (struct archdr )skb->data;
1da177e4 LT	91	struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
	92	int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
	93
	94	/* Pull off the arcnet header. */
459a98ed	95	skb_reset_mac_header(skb);
1da177e4 LT	96	skb_pull(skb, hdr_size);
1da177e4 LT	97
7f5e760c	98	if (pkt->hard.dest == 0) {
1da177e4	99	skb->pkt_type = PACKET_BROADCAST;
7f5e760c	100	} else if (dev->flags & IFF_PROMISC) {
1da177e4 LT	101	/* if we're not sending to ourselves :) */
	102	if (pkt->hard.dest != dev->dev_addr[0])
	103	skb->pkt_type = PACKET_OTHERHOST;
	104	}
	105	/* now return the protocol number */
	106	switch (soft->proto) {
	107	case ARC_P_IP_RFC1051:
	108	return htons(ETH_P_IP);
	109	case ARC_P_ARP_RFC1051:
	110	return htons(ETH_P_ARP);
	111
	112	default:
5803c512 SH	113	dev->stats.rx_errors++;
5803c512 SH	114	dev->stats.rx_crc_errors++;
1da177e4 LT	115	return 0;
	116	}
	117
	118	return htons(ETH_P_IP);
	119	}
	120
1da177e4 LT	121	/* packet receiver */
	122	static void rx(struct net_device *dev, int bufnum,
	123	struct archdr *pkthdr, int length)
	124	{
454d7c9b	125	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	126	struct sk_buff *skb;
	127	struct archdr *pkt = pkthdr;
	128	int ofs;
	129
a34c0932	130	arc_printk(D_DURING, dev, "it's a raw packet (length=%d)\n", length);
1da177e4 LT	131
	132	if (length >= MinTU)
	133	ofs = 512 - length;
	134	else
	135	ofs = 256 - length;
	136
	137	skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
d8101e7b	138	if (!skb) {
5803c512	139	dev->stats.rx_dropped++;
1da177e4 LT	140	return;
	141	}
	142	skb_put(skb, length + ARC_HDR_SIZE);
	143	skb->dev = dev;
	144
cb334648	145	pkt = (struct archdr *)skb->data;
1da177e4 LT	146
	147	/* up to sizeof(pkt->soft) has already been copied from the card */
	148	memcpy(pkt, pkthdr, sizeof(struct archdr));
	149	if (length > sizeof(pkt->soft))
	150	lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
	151	pkt->soft.raw + sizeof(pkt->soft),
	152	length - sizeof(pkt->soft));
	153
72aeea48 JP	154	if (BUGLVL(D_SKB))
72aeea48 JP	155	arcnet_dump_skb(dev, skb, "rx");
1da177e4 LT	156
	157	skb->protocol = type_trans(skb, dev);
	158	netif_rx(skb);
1da177e4 LT	159	}
1da177e4 LT	160
f2f0a16b	161	/* Create the ARCnet hard/soft headers for RFC1051 */
1da177e4 LT	162	static int build_header(struct sk_buff skb, struct net_device dev,
	163	unsigned short type, uint8_t daddr)
	164	{
1da177e4	165	int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
d58ff351	166	struct archdr *pkt = skb_push(skb, hdr_size);
1da177e4 LT	167	struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
	168
	169	/* set the protocol ID according to RFC1051 */
	170	switch (type) {
	171	case ETH_P_IP:
	172	soft->proto = ARC_P_IP_RFC1051;
	173	break;
	174	case ETH_P_ARP:
	175	soft->proto = ARC_P_ARP_RFC1051;
	176	break;
	177	default:
a34c0932 JP	178	arc_printk(D_NORMAL, dev, "RFC1051: I don't understand protocol %d (%Xh)\n",
a34c0932 JP	179	type, type);
5803c512 SH	180	dev->stats.tx_errors++;
5803c512 SH	181	dev->stats.tx_aborted_errors++;
1da177e4 LT	182	return 0;
	183	}
	184
f2f0a16b	185	/* Set the source hardware address.
1da177e4 LT	186	*
1da177e4 LT	187	* This is pretty pointless for most purposes, but it can help in
f2f0a16b JP	188	* debugging. ARCnet does not allow us to change the source address
f2f0a16b JP	189	* in the actual packet sent.
1da177e4 LT	190	*/
	191	pkt->hard.source = *dev->dev_addr;
	192
	193	/* see linux/net/ethernet/eth.c to see where I got the following */
	194
	195	if (dev->flags & (IFF_LOOPBACK \| IFF_NOARP)) {
f2f0a16b JP	196	/* FIXME: fill in the last byte of the dest ipaddr here to
f2f0a16b JP	197	* better comply with RFC1051 in "noarp" mode.
1da177e4 LT	198	*/
	199	pkt->hard.dest = 0;
	200	return hdr_size;
	201	}
	202	/* otherwise, just fill it in and go! */
	203	pkt->hard.dest = daddr;
	204
	205	return hdr_size; /* success */
	206	}
	207
1da177e4 LT	208	static int prepare_tx(struct net_device dev, struct archdr pkt, int length,
	209	int bufnum)
	210	{
454d7c9b	211	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	212	struct arc_hardware *hard = &pkt->hard;
	213	int ofs;
	214
a34c0932 JP	215	arc_printk(D_DURING, dev, "prepare_tx: txbufs=%d/%d/%d\n",
a34c0932 JP	216	lp->next_tx, lp->cur_tx, bufnum);
1da177e4	217
d6d7d3ed JP	218	/* hard header is not included in packet length */
d6d7d3ed JP	219	length -= ARC_HDR_SIZE;
1da177e4 LT	220
	221	if (length > XMTU) {
	222	/* should never happen! other people already check for this. */
a34c0932 JP	223	arc_printk(D_NORMAL, dev, "Bug! prepare_tx with size %d (> %d)\n",
a34c0932 JP	224	length, XMTU);
1da177e4 LT	225	length = XMTU;
	226	}
	227	if (length > MinTU) {
	228	hard->offset[0] = 0;
	229	hard->offset[1] = ofs = 512 - length;
	230	} else if (length > MTU) {
	231	hard->offset[0] = 0;
	232	hard->offset[1] = ofs = 512 - length - 3;
7f5e760c	233	} else {
1da177e4	234	hard->offset[0] = ofs = 256 - length;
7f5e760c	235	}
1da177e4 LT	236
	237	lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
	238	lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
	239
	240	lp->lastload_dest = hard->dest;
	241
	242	return 1; /* done */
	243	}