[mirror_ubuntu-artful-kernel.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
 *
 * **********************
 */
#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: RFC1051 \"simple standard\" (`s') encapsulation support loaded.\n"

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)
{
	printk(VERSION);

	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_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;

	BUGMSG(D_DURING, "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 == NULL) {
		BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
		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));

	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 = (struct archdr *)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:
		BUGMSG(D_NORMAL, "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;

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

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

	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;
	}

	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	*/
	26	#include <linux/module.h>
5a0e3ad6	27	#include <linux/gfp.h>
1da177e4 LT	28	#include <linux/init.h>
	29	#include <linux/if_arp.h>
	30	#include <net/arp.h>
	31	#include <linux/netdevice.h>
	32	#include <linux/skbuff.h>
	33	#include <linux/arcdevice.h>
	34
	35	#define VERSION "arcnet: RFC1051 \"simple standard\" (`s') encapsulation support loaded.\n"
	36
701181ac	37	static __be16 type_trans(struct sk_buff skb, struct net_device dev);
1da177e4 LT	38	static void rx(struct net_device *dev, int bufnum,
	39	struct archdr *pkthdr, int length);
	40	static int build_header(struct sk_buff skb, struct net_device dev,
	41	unsigned short type, uint8_t daddr);
	42	static int prepare_tx(struct net_device dev, struct archdr pkt, int length,
	43	int bufnum);
	44
7f5e760c	45	static struct ArcProto rfc1051_proto = {
1da177e4 LT	46	.suffix = 's',
	47	.mtu = XMTU - RFC1051_HDR_SIZE,
	48	.is_ip = 1,
	49	.rx = rx,
	50	.build_header = build_header,
	51	.prepare_tx = prepare_tx,
	52	.continue_tx = NULL,
	53	.ack_tx = NULL
	54	};
	55
1da177e4 LT	56	static int __init arcnet_rfc1051_init(void)
	57	{
	58	printk(VERSION);
	59
	60	arc_proto_map[ARC_P_IP_RFC1051]
	61	= arc_proto_map[ARC_P_ARP_RFC1051]
	62	= &rfc1051_proto;
	63
	64	/* if someone else already owns the broadcast, we won't take it */
	65	if (arc_bcast_proto == arc_proto_default)
	66	arc_bcast_proto = &rfc1051_proto;
	67
	68	return 0;
	69	}
	70
	71	static void __exit arcnet_rfc1051_exit(void)
	72	{
	73	arcnet_unregister_proto(&rfc1051_proto);
	74	}
	75
	76	module_init(arcnet_rfc1051_init);
	77	module_exit(arcnet_rfc1051_exit);
	78
	79	MODULE_LICENSE("GPL");
	80
	81	/*
	82	* Determine a packet's protocol ID.
cb334648	83	*
1da177e4 LT	84	* With ARCnet we have to convert everything to Ethernet-style stuff.
1da177e4 LT	85	*/
701181ac	86	static __be16 type_trans(struct sk_buff skb, struct net_device dev)
1da177e4	87	{
cb334648	88	struct archdr pkt = (struct archdr )skb->data;
1da177e4 LT	89	struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
	90	int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
	91
	92	/* Pull off the arcnet header. */
459a98ed	93	skb_reset_mac_header(skb);
1da177e4 LT	94	skb_pull(skb, hdr_size);
1da177e4 LT	95
7f5e760c	96	if (pkt->hard.dest == 0) {
1da177e4	97	skb->pkt_type = PACKET_BROADCAST;
7f5e760c	98	} else if (dev->flags & IFF_PROMISC) {
1da177e4 LT	99	/* if we're not sending to ourselves :) */
	100	if (pkt->hard.dest != dev->dev_addr[0])
	101	skb->pkt_type = PACKET_OTHERHOST;
	102	}
	103	/* now return the protocol number */
	104	switch (soft->proto) {
	105	case ARC_P_IP_RFC1051:
	106	return htons(ETH_P_IP);
	107	case ARC_P_ARP_RFC1051:
	108	return htons(ETH_P_ARP);
	109
	110	default:
5803c512 SH	111	dev->stats.rx_errors++;
5803c512 SH	112	dev->stats.rx_crc_errors++;
1da177e4 LT	113	return 0;
	114	}
	115
	116	return htons(ETH_P_IP);
	117	}
	118
1da177e4 LT	119	/* packet receiver */
	120	static void rx(struct net_device *dev, int bufnum,
	121	struct archdr *pkthdr, int length)
	122	{
454d7c9b	123	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	124	struct sk_buff *skb;
	125	struct archdr *pkt = pkthdr;
	126	int ofs;
	127
	128	BUGMSG(D_DURING, "it's a raw packet (length=%d)\n", length);
	129
	130	if (length >= MinTU)
	131	ofs = 512 - length;
	132	else
	133	ofs = 256 - length;
	134
	135	skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
	136	if (skb == NULL) {
	137	BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
5803c512	138	dev->stats.rx_dropped++;
1da177e4 LT	139	return;
	140	}
	141	skb_put(skb, length + ARC_HDR_SIZE);
	142	skb->dev = dev;
	143
cb334648	144	pkt = (struct archdr *)skb->data;
1da177e4 LT	145
	146	/* up to sizeof(pkt->soft) has already been copied from the card */
	147	memcpy(pkt, pkthdr, sizeof(struct archdr));
	148	if (length > sizeof(pkt->soft))
	149	lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
	150	pkt->soft.raw + sizeof(pkt->soft),
	151	length - sizeof(pkt->soft));
	152
	153	BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
	154
	155	skb->protocol = type_trans(skb, dev);
	156	netif_rx(skb);
1da177e4 LT	157	}
1da177e4 LT	158
1da177e4 LT	159	/*
	160	* Create the ARCnet hard/soft headers for RFC1051.
	161	*/
	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;
cb334648	166	struct archdr pkt = (struct archdr )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:
	178	BUGMSG(D_NORMAL, "RFC1051: I don't understand protocol %d (%Xh)\n",
	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
1da177e4 LT	185	/*
	186	* Set the source hardware address.
	187	*
	188	* This is pretty pointless for most purposes, but it can help in
	189	* debugging. ARCnet does not allow us to change the source address in
	190	* the actual packet sent)
	191	*/
	192	pkt->hard.source = *dev->dev_addr;
	193
	194	/* see linux/net/ethernet/eth.c to see where I got the following */
	195
	196	if (dev->flags & (IFF_LOOPBACK \| IFF_NOARP)) {
cb334648	197	/*
1da177e4 LT	198	* FIXME: fill in the last byte of the dest ipaddr here to better
	199	* comply with RFC1051 in "noarp" mode.
	200	*/
	201	pkt->hard.dest = 0;
	202	return hdr_size;
	203	}
	204	/* otherwise, just fill it in and go! */
	205	pkt->hard.dest = daddr;
	206
	207	return hdr_size; /* success */
	208	}
	209
1da177e4 LT	210	static int prepare_tx(struct net_device dev, struct archdr pkt, int length,
	211	int bufnum)
	212	{
454d7c9b	213	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	214	struct arc_hardware *hard = &pkt->hard;
	215	int ofs;
	216
	217	BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
	218	lp->next_tx, lp->cur_tx, bufnum);
	219
	220	length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
	221
	222	if (length > XMTU) {
	223	/* should never happen! other people already check for this. */
	224	BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n",
	225	length, XMTU);
	226	length = XMTU;
	227	}
	228	if (length > MinTU) {
	229	hard->offset[0] = 0;
	230	hard->offset[1] = ofs = 512 - length;
	231	} else if (length > MTU) {
	232	hard->offset[0] = 0;
	233	hard->offset[1] = ofs = 512 - length - 3;
7f5e760c	234	} else {
1da177e4	235	hard->offset[0] = ofs = 256 - length;
7f5e760c	236	}
1da177e4 LT	237
	238	lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
	239	lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
	240
	241	lp->lastload_dest = hard->dest;
	242
	243	return 1; /* done */
	244	}