[mirror_ubuntu-zesty-kernel.git] / drivers / net / arcnet / rfc1201.c

/*
 * Linux ARCnet driver - RFC1201 (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/gfp.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>

#include "arcdevice.h"

MODULE_LICENSE("GPL");

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 int continue_tx(struct net_device *dev, int bufnum);

static struct ArcProto rfc1201_proto = {
	.suffix		= 'a',
	.mtu		= 1500,	/* could be more, but some receivers can't handle it... */
	.is_ip          = 1,    /* This is for sending IP and ARP packages */
	.rx		= rx,
	.build_header	= build_header,
	.prepare_tx	= prepare_tx,
	.continue_tx	= continue_tx,
	.ack_tx         = NULL
};

static int __init arcnet_rfc1201_init(void)
{
	pr_info("%s\n", "RFC1201 \"standard\" (`a') encapsulation support loaded");

	arc_proto_map[ARC_P_IP]
	    = arc_proto_map[ARC_P_IPV6]
	    = arc_proto_map[ARC_P_ARP]
	    = arc_proto_map[ARC_P_RARP]
	    = arc_proto_map[ARC_P_IPX]
	    = arc_proto_map[ARC_P_NOVELL_EC]
	    = &rfc1201_proto;

	/* if someone else already owns the broadcast, we won't take it */
	if (arc_bcast_proto == arc_proto_default)
		arc_bcast_proto = &rfc1201_proto;

	return 0;
}

static void __exit arcnet_rfc1201_exit(void)
{
	arcnet_unregister_proto(&rfc1201_proto);
}

module_init(arcnet_rfc1201_init);
module_exit(arcnet_rfc1201_exit);

/* 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_rfc1201 *soft = &pkt->soft.rfc1201;
	int hdr_size = ARC_HDR_SIZE + RFC1201_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:
		return htons(ETH_P_IP);
	case ARC_P_IPV6:
		return htons(ETH_P_IPV6);
	case ARC_P_ARP:
		return htons(ETH_P_ARP);
	case ARC_P_RARP:
		return htons(ETH_P_RARP);

	case ARC_P_IPX:
	case ARC_P_NOVELL_EC:
		return htons(ETH_P_802_3);
	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;
	struct arc_rfc1201 *soft = &pkthdr->soft.rfc1201;
	int saddr = pkt->hard.source, ofs;
	struct Incoming *in = &lp->rfc1201.incoming[saddr];

	arc_printk(D_DURING, dev, "it's an RFC1201 packet (length=%d)\n",
		   length);

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

	if (soft->split_flag == 0xFF) {		/* Exception Packet */
		if (length >= 4 + RFC1201_HDR_SIZE) {
			arc_printk(D_DURING, dev, "compensating for exception packet\n");
		} else {
			arc_printk(D_EXTRA, dev, "short RFC1201 exception packet from %02Xh",
				   saddr);
			return;
		}

		/* skip over 4-byte junkola */
		length -= 4;
		ofs += 4;
		lp->hw.copy_from_card(dev, bufnum, 512 - length,
				      soft, sizeof(pkt->soft));
	}
	if (!soft->split_flag) {	/* not split */
		arc_printk(D_RX, dev, "incoming is not split (splitflag=%d)\n",
			   soft->split_flag);

		if (in->skb) {	/* already assembling one! */
			arc_printk(D_EXTRA, dev, "aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n",
				   in->sequence, soft->split_flag,
				   soft->sequence);
			lp->rfc1201.aborted_seq = soft->sequence;
			dev_kfree_skb_irq(in->skb);
			dev->stats.rx_errors++;
			dev->stats.rx_missed_errors++;
			in->skb = NULL;
		}
		in->sequence = soft->sequence;

		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;
		soft = &pkt->soft.rfc1201;

		/* 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));

		/* ARP packets have problems when sent from some DOS systems:
		 * the source address is always 0!
		 * So we take the hardware source addr (which is impossible
		 * to fumble) and insert it ourselves.
		 */
		if (soft->proto == ARC_P_ARP) {
			struct arphdr *arp = (struct arphdr *)soft->payload;

			/* make sure addresses are the right length */
			if (arp->ar_hln == 1 && arp->ar_pln == 4) {
				uint8_t *cptr = (uint8_t *)arp + sizeof(struct arphdr);

				if (!*cptr) {	/* is saddr = 00? */
					arc_printk(D_EXTRA, dev,
						   "ARP source address was 00h, set to %02Xh\n",
						   saddr);
					dev->stats.rx_crc_errors++;
					*cptr = saddr;
				} else {
					arc_printk(D_DURING, dev, "ARP source address (%Xh) is fine.\n",
						   *cptr);
				}
			} else {
				arc_printk(D_NORMAL, dev, "funny-shaped ARP packet. (%Xh, %Xh)\n",
					   arp->ar_hln, arp->ar_pln);
				dev->stats.rx_errors++;
				dev->stats.rx_crc_errors++;
			}
		}
		if (BUGLVL(D_SKB))
			arcnet_dump_skb(dev, skb, "rx");

		skb->protocol = type_trans(skb, dev);
		netif_rx(skb);
	} else {		/* split packet */
		/* NOTE: MSDOS ARP packet correction should only need to
		 * apply to unsplit packets, since ARP packets are so short.
		 *
		 * My interpretation of the RFC1201 document is that if a
		 * packet is received out of order, the entire assembly
		 * process should be aborted.
		 *
		 * The RFC also mentions "it is possible for successfully
		 * received packets to be retransmitted." As of 0.40 all
		 * previously received packets are allowed, not just the
		 * most recent one.
		 *
		 * We allow multiple assembly processes, one for each
		 * ARCnet card possible on the network.
		 * Seems rather like a waste of memory, but there's no
		 * other way to be reliable.
		 */

		arc_printk(D_RX, dev, "packet is split (splitflag=%d, seq=%d)\n",
			   soft->split_flag, in->sequence);

		if (in->skb && in->sequence != soft->sequence) {
			arc_printk(D_EXTRA, dev, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n",
				   saddr, in->sequence, soft->sequence,
				   soft->split_flag);
			dev_kfree_skb_irq(in->skb);
			in->skb = NULL;
			dev->stats.rx_errors++;
			dev->stats.rx_missed_errors++;
			in->lastpacket = in->numpackets = 0;
		}
		if (soft->split_flag & 1) {	/* first packet in split */
			arc_printk(D_RX, dev, "brand new splitpacket (splitflag=%d)\n",
				   soft->split_flag);
			if (in->skb) {	/* already assembling one! */
				arc_printk(D_EXTRA, dev, "aborting previous (seq=%d) assembly (splitflag=%d, seq=%d)\n",
					   in->sequence, soft->split_flag,
					   soft->sequence);
				dev->stats.rx_errors++;
				dev->stats.rx_missed_errors++;
				dev_kfree_skb_irq(in->skb);
			}
			in->sequence = soft->sequence;
			in->numpackets = ((unsigned)soft->split_flag >> 1) + 2;
			in->lastpacket = 1;

			if (in->numpackets > 16) {
				arc_printk(D_EXTRA, dev, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n",
					   soft->split_flag);
				lp->rfc1201.aborted_seq = soft->sequence;
				dev->stats.rx_errors++;
				dev->stats.rx_length_errors++;
				return;
			}
			in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE,
						  GFP_ATOMIC);
			if (!skb) {
				arc_printk(D_NORMAL, dev, "(split) memory squeeze, dropping packet.\n");
				lp->rfc1201.aborted_seq = soft->sequence;
				dev->stats.rx_dropped++;
				return;
			}
			skb->dev = dev;
			pkt = (struct archdr *)skb->data;
			soft = &pkt->soft.rfc1201;

			memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
			skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE);

			soft->split_flag = 0;	/* end result won't be split */
		} else {	/* not first packet */
			int packetnum = ((unsigned)soft->split_flag >> 1) + 1;

			/* if we're not assembling, there's no point trying to
			 * continue.
			 */
			if (!in->skb) {
				if (lp->rfc1201.aborted_seq != soft->sequence) {
					arc_printk(D_EXTRA, dev, "can't continue split without starting first! (splitflag=%d, seq=%d, aborted=%d)\n",
						   soft->split_flag,
						   soft->sequence,
						   lp->rfc1201.aborted_seq);
					dev->stats.rx_errors++;
					dev->stats.rx_missed_errors++;
				}
				return;
			}
			in->lastpacket++;
			/* if not the right flag */
			if (packetnum != in->lastpacket) {
				/* harmless duplicate? ignore. */
				if (packetnum <= in->lastpacket - 1) {
					arc_printk(D_EXTRA, dev, "duplicate splitpacket ignored! (splitflag=%d)\n",
						   soft->split_flag);
					dev->stats.rx_errors++;
					dev->stats.rx_frame_errors++;
					return;
				}
				/* "bad" duplicate, kill reassembly */
				arc_printk(D_EXTRA, dev, "out-of-order splitpacket, reassembly (seq=%d) aborted (splitflag=%d, seq=%d)\n",
					   in->sequence, soft->split_flag,
					   soft->sequence);
				lp->rfc1201.aborted_seq = soft->sequence;
				dev_kfree_skb_irq(in->skb);
				in->skb = NULL;
				dev->stats.rx_errors++;
				dev->stats.rx_missed_errors++;
				in->lastpacket = in->numpackets = 0;
				return;
			}
			pkt = (struct archdr *)in->skb->data;
			soft = &pkt->soft.rfc1201;
		}

		skb = in->skb;

		lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE,
				      skb->data + skb->len,
				      length - RFC1201_HDR_SIZE);
		skb_put(skb, length - RFC1201_HDR_SIZE);

		/* are we done? */
		if (in->lastpacket == in->numpackets) {
			in->skb = NULL;
			in->lastpacket = in->numpackets = 0;

			arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (unsplit)\n",
				   skb->len, pkt->hard.source);
			arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (split)\n",
				   skb->len, pkt->hard.source);
			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 RFC1201. */
static int build_header(struct sk_buff *skb, struct net_device *dev,
			unsigned short type, uint8_t daddr)
{
	struct arcnet_local *lp = netdev_priv(dev);
	int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
	struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
	struct arc_rfc1201 *soft = &pkt->soft.rfc1201;

	/* set the protocol ID according to RFC1201 */
	switch (type) {
	case ETH_P_IP:
		soft->proto = ARC_P_IP;
		break;
	case ETH_P_IPV6:
		soft->proto = ARC_P_IPV6;
		break;
	case ETH_P_ARP:
		soft->proto = ARC_P_ARP;
		break;
	case ETH_P_RARP:
		soft->proto = ARC_P_RARP;
		break;
	case ETH_P_IPX:
	case ETH_P_802_3:
	case ETH_P_802_2:
		soft->proto = ARC_P_IPX;
		break;
	case ETH_P_ATALK:
		soft->proto = ARC_P_ATALK;
		break;
	default:
		arc_printk(D_NORMAL, dev, "RFC1201: 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;

	soft->sequence = htons(lp->rfc1201.sequence++);
	soft->split_flag = 0;	/* split packets are done elsewhere */

	/* 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.
		 * For now, always broadcasting will probably at least get
		 * packets sent out :)
		 */
		pkt->hard.dest = 0;
		return hdr_size;
	}
	/* otherwise, drop in the dest address */
	pkt->hard.dest = daddr;
	return hdr_size;
}

static void load_pkt(struct net_device *dev, struct arc_hardware *hard,
		     struct arc_rfc1201 *soft, int softlen, int bufnum)
{
	struct arcnet_local *lp = netdev_priv(dev);
	int ofs;

	/* assume length <= XMTU: someone should have handled that by now. */

	if (softlen > MinTU) {
		hard->offset[0] = 0;
		hard->offset[1] = ofs = 512 - softlen;
	} else if (softlen > MTU) {	/* exception packet - add an extra header */
		struct arc_rfc1201 excsoft;

		excsoft.proto = soft->proto;
		excsoft.split_flag = 0xff;
		excsoft.sequence = htons(0xffff);

		hard->offset[0] = 0;
		ofs = 512 - softlen;
		hard->offset[1] = ofs - RFC1201_HDR_SIZE;
		lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE,
				    &excsoft, RFC1201_HDR_SIZE);
	} else {
		hard->offset[0] = ofs = 256 - softlen;
	}

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

	lp->lastload_dest = hard->dest;
}

static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
		      int bufnum)
{
	struct arcnet_local *lp = netdev_priv(dev);
	const int maxsegsize = XMTU - RFC1201_HDR_SIZE;
	struct Outgoing *out;

	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;
	pkt->soft.rfc1201.split_flag = 0;

	/* need to do a split packet? */
	if (length > XMTU) {
		out = &lp->outgoing;

		out->length = length - RFC1201_HDR_SIZE;
		out->dataleft = lp->outgoing.length;
		out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize;
		out->segnum = 0;

		arc_printk(D_DURING, dev, "rfc1201 prep_tx: ready for %d-segment split (%d bytes, seq=%d)\n",
			   out->numsegs, out->length,
			   pkt->soft.rfc1201.sequence);

		return 0;	/* not done */
	}
	/* just load the packet into the buffers and send it off */
	load_pkt(dev, &pkt->hard, &pkt->soft.rfc1201, length, bufnum);

	return 1;		/* done */
}

static int continue_tx(struct net_device *dev, int bufnum)
{
	struct arcnet_local *lp = netdev_priv(dev);
	struct Outgoing *out = &lp->outgoing;
	struct arc_hardware *hard = &out->pkt->hard;
	struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft;
	int maxsegsize = XMTU - RFC1201_HDR_SIZE;
	int seglen;

	arc_printk(D_DURING, dev,
		   "rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n",
		   out->segnum, out->numsegs, soft->sequence);

	/* the "new" soft header comes right before the data chunk */
	newsoft = (struct arc_rfc1201 *)
	    (out->pkt->soft.raw + out->length - out->dataleft);

	if (!out->segnum)	/* first packet; newsoft == soft */
		newsoft->split_flag = ((out->numsegs - 2) << 1) | 1;
	else {
		newsoft->split_flag = out->segnum << 1;
		newsoft->proto = soft->proto;
		newsoft->sequence = soft->sequence;
	}

	seglen = maxsegsize;
	if (seglen > out->dataleft)
		seglen = out->dataleft;
	out->dataleft -= seglen;

	load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum);

	out->segnum++;
	if (out->segnum >= out->numsegs)
		return 1;
	else
		return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* Linux ARCnet driver - RFC1201 (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
5a0e3ad6	29	#include <linux/gfp.h>
1da177e4 LT	30	#include <linux/module.h>
	31	#include <linux/init.h>
	32	#include <linux/if_arp.h>
	33	#include <linux/netdevice.h>
	34	#include <linux/skbuff.h>
26c6d281 JP	35
26c6d281 JP	36	#include "arcdevice.h"
1da177e4 LT	37
1da177e4 LT	38	MODULE_LICENSE("GPL");
1da177e4	39
701181ac	40	static __be16 type_trans(struct sk_buff skb, struct net_device dev);
1da177e4 LT	41	static void rx(struct net_device *dev, int bufnum,
	42	struct archdr *pkthdr, int length);
	43	static int build_header(struct sk_buff skb, struct net_device dev,
	44	unsigned short type, uint8_t daddr);
	45	static int prepare_tx(struct net_device dev, struct archdr pkt, int length,
	46	int bufnum);
	47	static int continue_tx(struct net_device *dev, int bufnum);
	48
7f5e760c	49	static struct ArcProto rfc1201_proto = {
1da177e4 LT	50	.suffix = 'a',
	51	.mtu = 1500, /* could be more, but some receivers can't handle it... */
	52	.is_ip = 1, /* This is for sending IP and ARP packages */
	53	.rx = rx,
	54	.build_header = build_header,
	55	.prepare_tx = prepare_tx,
	56	.continue_tx = continue_tx,
	57	.ack_tx = NULL
	58	};
	59
1da177e4 LT	60	static int __init arcnet_rfc1201_init(void)
1da177e4 LT	61	{
05a24b23	62	pr_info("%s\n", "RFC1201 \"standard\" (`a') encapsulation support loaded");
1da177e4 LT	63
	64	arc_proto_map[ARC_P_IP]
	65	= arc_proto_map[ARC_P_IPV6]
	66	= arc_proto_map[ARC_P_ARP]
	67	= arc_proto_map[ARC_P_RARP]
	68	= arc_proto_map[ARC_P_IPX]
	69	= arc_proto_map[ARC_P_NOVELL_EC]
	70	= &rfc1201_proto;
	71
	72	/* if someone else already owns the broadcast, we won't take it */
	73	if (arc_bcast_proto == arc_proto_default)
	74	arc_bcast_proto = &rfc1201_proto;
	75
	76	return 0;
	77	}
	78
	79	static void __exit arcnet_rfc1201_exit(void)
	80	{
	81	arcnet_unregister_proto(&rfc1201_proto);
	82	}
	83
	84	module_init(arcnet_rfc1201_init);
	85	module_exit(arcnet_rfc1201_exit);
	86
f2f0a16b	87	/* Determine a packet's protocol ID.
cb334648	88	*
1da177e4 LT	89	* With ARCnet we have to convert everything to Ethernet-style stuff.
1da177e4 LT	90	*/
701181ac	91	static __be16 type_trans(struct sk_buff skb, struct net_device dev)
1da177e4	92	{
cb334648	93	struct archdr pkt = (struct archdr )skb->data;
1da177e4	94	struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
1da177e4 LT	95	int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
	96
	97	/* Pull off the arcnet header. */
459a98ed	98	skb_reset_mac_header(skb);
1da177e4 LT	99	skb_pull(skb, hdr_size);
1da177e4 LT	100
7f5e760c	101	if (pkt->hard.dest == 0) {
1da177e4	102	skb->pkt_type = PACKET_BROADCAST;
7f5e760c	103	} else if (dev->flags & IFF_PROMISC) {
1da177e4 LT	104	/* if we're not sending to ourselves :) */
	105	if (pkt->hard.dest != dev->dev_addr[0])
	106	skb->pkt_type = PACKET_OTHERHOST;
	107	}
	108	/* now return the protocol number */
	109	switch (soft->proto) {
	110	case ARC_P_IP:
	111	return htons(ETH_P_IP);
	112	case ARC_P_IPV6:
	113	return htons(ETH_P_IPV6);
	114	case ARC_P_ARP:
	115	return htons(ETH_P_ARP);
	116	case ARC_P_RARP:
	117	return htons(ETH_P_RARP);
	118
	119	case ARC_P_IPX:
	120	case ARC_P_NOVELL_EC:
	121	return htons(ETH_P_802_3);
	122	default:
5803c512 SH	123	dev->stats.rx_errors++;
5803c512 SH	124	dev->stats.rx_crc_errors++;
1da177e4 LT	125	return 0;
	126	}
	127
	128	return htons(ETH_P_IP);
	129	}
	130
1da177e4 LT	131	/* packet receiver */
	132	static void rx(struct net_device *dev, int bufnum,
	133	struct archdr *pkthdr, int length)
	134	{
454d7c9b	135	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	136	struct sk_buff *skb;
	137	struct archdr *pkt = pkthdr;
	138	struct arc_rfc1201 *soft = &pkthdr->soft.rfc1201;
	139	int saddr = pkt->hard.source, ofs;
	140	struct Incoming *in = &lp->rfc1201.incoming[saddr];
	141
a34c0932 JP	142	arc_printk(D_DURING, dev, "it's an RFC1201 packet (length=%d)\n",
a34c0932 JP	143	length);
1da177e4 LT	144
	145	if (length >= MinTU)
	146	ofs = 512 - length;
	147	else
	148	ofs = 256 - length;
	149
	150	if (soft->split_flag == 0xFF) { /* Exception Packet */
7f5e760c	151	if (length >= 4 + RFC1201_HDR_SIZE) {
a34c0932	152	arc_printk(D_DURING, dev, "compensating for exception packet\n");
7f5e760c	153	} else {
a34c0932 JP	154	arc_printk(D_EXTRA, dev, "short RFC1201 exception packet from %02Xh",
a34c0932 JP	155	saddr);
1da177e4 LT	156	return;
	157	}
	158
	159	/* skip over 4-byte junkola */
	160	length -= 4;
	161	ofs += 4;
	162	lp->hw.copy_from_card(dev, bufnum, 512 - length,
	163	soft, sizeof(pkt->soft));
	164	}
	165	if (!soft->split_flag) { /* not split */
a34c0932 JP	166	arc_printk(D_RX, dev, "incoming is not split (splitflag=%d)\n",
a34c0932 JP	167	soft->split_flag);
1da177e4 LT	168
1da177e4 LT	169	if (in->skb) { /* already assembling one! */
a34c0932 JP	170	arc_printk(D_EXTRA, dev, "aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n",
	171	in->sequence, soft->split_flag,
	172	soft->sequence);
1da177e4 LT	173	lp->rfc1201.aborted_seq = soft->sequence;
1da177e4 LT	174	dev_kfree_skb_irq(in->skb);
5803c512 SH	175	dev->stats.rx_errors++;
5803c512 SH	176	dev->stats.rx_missed_errors++;
1da177e4 LT	177	in->skb = NULL;
	178	}
	179	in->sequence = soft->sequence;
	180
	181	skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
d8101e7b	182	if (!skb) {
5803c512	183	dev->stats.rx_dropped++;
1da177e4 LT	184	return;
	185	}
	186	skb_put(skb, length + ARC_HDR_SIZE);
	187	skb->dev = dev;
	188
cb334648	189	pkt = (struct archdr *)skb->data;
1da177e4 LT	190	soft = &pkt->soft.rfc1201;
1da177e4 LT	191
d6d7d3ed JP	192	/* up to sizeof(pkt->soft) has already
	193	* been copied from the card
	194	*/
1da177e4 LT	195	memcpy(pkt, pkthdr, sizeof(struct archdr));
1da177e4 LT	196	if (length > sizeof(pkt->soft))
d6d7d3ed JP	197	lp->hw.copy_from_card(dev, bufnum,
	198	ofs + sizeof(pkt->soft),
	199	pkt->soft.raw + sizeof(pkt->soft),
1da177e4 LT	200	length - sizeof(pkt->soft));
1da177e4 LT	201
f2f0a16b JP	202	/* ARP packets have problems when sent from some DOS systems:
	203	* the source address is always 0!
	204	* So we take the hardware source addr (which is impossible
	205	* to fumble) and insert it ourselves.
1da177e4 LT	206	*/
1da177e4 LT	207	if (soft->proto == ARC_P_ARP) {
cb334648	208	struct arphdr arp = (struct arphdr )soft->payload;
1da177e4 LT	209
	210	/* make sure addresses are the right length */
	211	if (arp->ar_hln == 1 && arp->ar_pln == 4) {
cb334648	212	uint8_t cptr = (uint8_t )arp + sizeof(struct arphdr);
1da177e4 LT	213
1da177e4 LT	214	if (!cptr) { / is saddr = 00? */
a34c0932 JP	215	arc_printk(D_EXTRA, dev,
	216	"ARP source address was 00h, set to %02Xh\n",
	217	saddr);
5803c512	218	dev->stats.rx_crc_errors++;
1da177e4 LT	219	*cptr = saddr;
1da177e4 LT	220	} else {
a34c0932 JP	221	arc_printk(D_DURING, dev, "ARP source address (%Xh) is fine.\n",
a34c0932 JP	222	*cptr);
1da177e4 LT	223	}
1da177e4 LT	224	} else {
a34c0932 JP	225	arc_printk(D_NORMAL, dev, "funny-shaped ARP packet. (%Xh, %Xh)\n",
a34c0932 JP	226	arp->ar_hln, arp->ar_pln);
5803c512 SH	227	dev->stats.rx_errors++;
5803c512 SH	228	dev->stats.rx_crc_errors++;
1da177e4 LT	229	}
1da177e4 LT	230	}
72aeea48 JP	231	if (BUGLVL(D_SKB))
72aeea48 JP	232	arcnet_dump_skb(dev, skb, "rx");
1da177e4 LT	233
	234	skb->protocol = type_trans(skb, dev);
	235	netif_rx(skb);
1da177e4	236	} else { /* split packet */
f2f0a16b JP	237	/* NOTE: MSDOS ARP packet correction should only need to
f2f0a16b JP	238	* apply to unsplit packets, since ARP packets are so short.
1da177e4	239	*
f2f0a16b JP	240	* My interpretation of the RFC1201 document is that if a
	241	* packet is received out of order, the entire assembly
	242	* process should be aborted.
1da177e4	243	*
f2f0a16b JP	244	* The RFC also mentions "it is possible for successfully
	245	* received packets to be retransmitted." As of 0.40 all
	246	* previously received packets are allowed, not just the
	247	* most recent one.
1da177e4	248	*
f2f0a16b JP	249	* We allow multiple assembly processes, one for each
	250	* ARCnet card possible on the network.
	251	* Seems rather like a waste of memory, but there's no
	252	* other way to be reliable.
1da177e4 LT	253	*/
1da177e4 LT	254
a34c0932 JP	255	arc_printk(D_RX, dev, "packet is split (splitflag=%d, seq=%d)\n",
a34c0932 JP	256	soft->split_flag, in->sequence);
1da177e4 LT	257
1da177e4 LT	258	if (in->skb && in->sequence != soft->sequence) {
a34c0932 JP	259	arc_printk(D_EXTRA, dev, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n",
	260	saddr, in->sequence, soft->sequence,
	261	soft->split_flag);
1da177e4 LT	262	dev_kfree_skb_irq(in->skb);
1da177e4 LT	263	in->skb = NULL;
5803c512 SH	264	dev->stats.rx_errors++;
5803c512 SH	265	dev->stats.rx_missed_errors++;
1da177e4 LT	266	in->lastpacket = in->numpackets = 0;
	267	}
	268	if (soft->split_flag & 1) { /* first packet in split */
a34c0932 JP	269	arc_printk(D_RX, dev, "brand new splitpacket (splitflag=%d)\n",
a34c0932 JP	270	soft->split_flag);
1da177e4	271	if (in->skb) { /* already assembling one! */
a34c0932 JP	272	arc_printk(D_EXTRA, dev, "aborting previous (seq=%d) assembly (splitflag=%d, seq=%d)\n",
	273	in->sequence, soft->split_flag,
	274	soft->sequence);
5803c512 SH	275	dev->stats.rx_errors++;
5803c512 SH	276	dev->stats.rx_missed_errors++;
1da177e4 LT	277	dev_kfree_skb_irq(in->skb);
	278	}
	279	in->sequence = soft->sequence;
cb334648	280	in->numpackets = ((unsigned)soft->split_flag >> 1) + 2;
1da177e4 LT	281	in->lastpacket = 1;
	282
	283	if (in->numpackets > 16) {
a34c0932 JP	284	arc_printk(D_EXTRA, dev, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n",
a34c0932 JP	285	soft->split_flag);
1da177e4	286	lp->rfc1201.aborted_seq = soft->sequence;
5803c512 SH	287	dev->stats.rx_errors++;
5803c512 SH	288	dev->stats.rx_length_errors++;
1da177e4 LT	289	return;
	290	}
	291	in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE,
	292	GFP_ATOMIC);
d8101e7b	293	if (!skb) {
a34c0932	294	arc_printk(D_NORMAL, dev, "(split) memory squeeze, dropping packet.\n");
1da177e4	295	lp->rfc1201.aborted_seq = soft->sequence;
5803c512	296	dev->stats.rx_dropped++;
1da177e4 LT	297	return;
	298	}
	299	skb->dev = dev;
cb334648	300	pkt = (struct archdr *)skb->data;
1da177e4 LT	301	soft = &pkt->soft.rfc1201;
	302
	303	memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
	304	skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
	305
	306	soft->split_flag = 0; /* end result won't be split */
	307	} else { /* not first packet */
cb334648	308	int packetnum = ((unsigned)soft->split_flag >> 1) + 1;
1da177e4	309
f2f0a16b	310	/* if we're not assembling, there's no point trying to
1da177e4 LT	311	* continue.
	312	*/
	313	if (!in->skb) {
	314	if (lp->rfc1201.aborted_seq != soft->sequence) {
a34c0932 JP	315	arc_printk(D_EXTRA, dev, "can't continue split without starting first! (splitflag=%d, seq=%d, aborted=%d)\n",
	316	soft->split_flag,
	317	soft->sequence,
	318	lp->rfc1201.aborted_seq);
5803c512 SH	319	dev->stats.rx_errors++;
5803c512 SH	320	dev->stats.rx_missed_errors++;
1da177e4 LT	321	}
	322	return;
	323	}
	324	in->lastpacket++;
d6d7d3ed JP	325	/* if not the right flag */
d6d7d3ed JP	326	if (packetnum != in->lastpacket) {
1da177e4 LT	327	/* harmless duplicate? ignore. */
1da177e4 LT	328	if (packetnum <= in->lastpacket - 1) {
a34c0932 JP	329	arc_printk(D_EXTRA, dev, "duplicate splitpacket ignored! (splitflag=%d)\n",
a34c0932 JP	330	soft->split_flag);
5803c512 SH	331	dev->stats.rx_errors++;
5803c512 SH	332	dev->stats.rx_frame_errors++;
1da177e4 LT	333	return;
	334	}
	335	/* "bad" duplicate, kill reassembly */
a34c0932 JP	336	arc_printk(D_EXTRA, dev, "out-of-order splitpacket, reassembly (seq=%d) aborted (splitflag=%d, seq=%d)\n",
	337	in->sequence, soft->split_flag,
	338	soft->sequence);
1da177e4 LT	339	lp->rfc1201.aborted_seq = soft->sequence;
	340	dev_kfree_skb_irq(in->skb);
	341	in->skb = NULL;
5803c512 SH	342	dev->stats.rx_errors++;
5803c512 SH	343	dev->stats.rx_missed_errors++;
1da177e4 LT	344	in->lastpacket = in->numpackets = 0;
	345	return;
	346	}
cb334648	347	pkt = (struct archdr *)in->skb->data;
1da177e4 LT	348	soft = &pkt->soft.rfc1201;
	349	}
	350
	351	skb = in->skb;
	352
	353	lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE,
	354	skb->data + skb->len,
	355	length - RFC1201_HDR_SIZE);
	356	skb_put(skb, length - RFC1201_HDR_SIZE);
	357
	358	/* are we done? */
	359	if (in->lastpacket == in->numpackets) {
	360	in->skb = NULL;
	361	in->lastpacket = in->numpackets = 0;
	362
a34c0932 JP	363	arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (unsplit)\n",
	364	skb->len, pkt->hard.source);
	365	arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (split)\n",
	366	skb->len, pkt->hard.source);
72aeea48 JP	367	if (BUGLVL(D_SKB))
72aeea48 JP	368	arcnet_dump_skb(dev, skb, "rx");
1da177e4 LT	369
	370	skb->protocol = type_trans(skb, dev);
	371	netif_rx(skb);
1da177e4 LT	372	}
	373	}
	374	}
	375
1da177e4 LT	376	/* Create the ARCnet hard/soft headers for RFC1201. */
	377	static int build_header(struct sk_buff skb, struct net_device dev,
	378	unsigned short type, uint8_t daddr)
	379	{
454d7c9b	380	struct arcnet_local *lp = netdev_priv(dev);
1da177e4	381	int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
cb334648	382	struct archdr pkt = (struct archdr )skb_push(skb, hdr_size);
1da177e4 LT	383	struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
	384
	385	/* set the protocol ID according to RFC1201 */
	386	switch (type) {
	387	case ETH_P_IP:
	388	soft->proto = ARC_P_IP;
	389	break;
	390	case ETH_P_IPV6:
	391	soft->proto = ARC_P_IPV6;
	392	break;
	393	case ETH_P_ARP:
	394	soft->proto = ARC_P_ARP;
	395	break;
	396	case ETH_P_RARP:
	397	soft->proto = ARC_P_RARP;
	398	break;
	399	case ETH_P_IPX:
	400	case ETH_P_802_3:
	401	case ETH_P_802_2:
	402	soft->proto = ARC_P_IPX;
	403	break;
	404	case ETH_P_ATALK:
	405	soft->proto = ARC_P_ATALK;
	406	break;
	407	default:
a34c0932 JP	408	arc_printk(D_NORMAL, dev, "RFC1201: I don't understand protocol %d (%Xh)\n",
a34c0932 JP	409	type, type);
5803c512 SH	410	dev->stats.tx_errors++;
5803c512 SH	411	dev->stats.tx_aborted_errors++;
1da177e4 LT	412	return 0;
	413	}
	414
f2f0a16b	415	/* Set the source hardware address.
1da177e4 LT	416	*
1da177e4 LT	417	* This is pretty pointless for most purposes, but it can help in
f2f0a16b JP	418	* debugging. ARCnet does not allow us to change the source address
f2f0a16b JP	419	* in the actual packet sent.
1da177e4 LT	420	*/
	421	pkt->hard.source = *dev->dev_addr;
	422
	423	soft->sequence = htons(lp->rfc1201.sequence++);
	424	soft->split_flag = 0; /* split packets are done elsewhere */
	425
	426	/* see linux/net/ethernet/eth.c to see where I got the following */
	427
	428	if (dev->flags & (IFF_LOOPBACK \| IFF_NOARP)) {
f2f0a16b JP	429	/* FIXME: fill in the last byte of the dest ipaddr here
	430	* to better comply with RFC1051 in "noarp" mode.
	431	* For now, always broadcasting will probably at least get
	432	* packets sent out :)
1da177e4 LT	433	*/
	434	pkt->hard.dest = 0;
	435	return hdr_size;
	436	}
	437	/* otherwise, drop in the dest address */
	438	pkt->hard.dest = daddr;
	439	return hdr_size;
	440	}
	441
1da177e4 LT	442	static void load_pkt(struct net_device dev, struct arc_hardware hard,
	443	struct arc_rfc1201 *soft, int softlen, int bufnum)
	444	{
454d7c9b	445	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	446	int ofs;
	447
	448	/* assume length <= XMTU: someone should have handled that by now. */
	449
	450	if (softlen > MinTU) {
	451	hard->offset[0] = 0;
	452	hard->offset[1] = ofs = 512 - softlen;
	453	} else if (softlen > MTU) { /* exception packet - add an extra header */
	454	struct arc_rfc1201 excsoft;
	455
	456	excsoft.proto = soft->proto;
	457	excsoft.split_flag = 0xff;
701181ac	458	excsoft.sequence = htons(0xffff);
1da177e4 LT	459
	460	hard->offset[0] = 0;
	461	ofs = 512 - softlen;
	462	hard->offset[1] = ofs - RFC1201_HDR_SIZE;
	463	lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE,
	464	&excsoft, RFC1201_HDR_SIZE);
7f5e760c	465	} else {
1da177e4	466	hard->offset[0] = ofs = 256 - softlen;
7f5e760c	467	}
1da177e4 LT	468
	469	lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
	470	lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen);
	471
	472	lp->lastload_dest = hard->dest;
	473	}
	474
1da177e4 LT	475	static int prepare_tx(struct net_device dev, struct archdr pkt, int length,
	476	int bufnum)
	477	{
454d7c9b	478	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	479	const int maxsegsize = XMTU - RFC1201_HDR_SIZE;
	480	struct Outgoing *out;
	481
a34c0932 JP	482	arc_printk(D_DURING, dev, "prepare_tx: txbufs=%d/%d/%d\n",
a34c0932 JP	483	lp->next_tx, lp->cur_tx, bufnum);
1da177e4	484
d6d7d3ed JP	485	/* hard header is not included in packet length */
d6d7d3ed JP	486	length -= ARC_HDR_SIZE;
1da177e4 LT	487	pkt->soft.rfc1201.split_flag = 0;
	488
	489	/* need to do a split packet? */
	490	if (length > XMTU) {
	491	out = &lp->outgoing;
	492
	493	out->length = length - RFC1201_HDR_SIZE;
	494	out->dataleft = lp->outgoing.length;
	495	out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize;
	496	out->segnum = 0;
	497
a34c0932 JP	498	arc_printk(D_DURING, dev, "rfc1201 prep_tx: ready for %d-segment split (%d bytes, seq=%d)\n",
	499	out->numsegs, out->length,
	500	pkt->soft.rfc1201.sequence);
1da177e4 LT	501
	502	return 0; /* not done */
	503	}
	504	/* just load the packet into the buffers and send it off */
	505	load_pkt(dev, &pkt->hard, &pkt->soft.rfc1201, length, bufnum);
	506
	507	return 1; /* done */
	508	}
	509
1da177e4 LT	510	static int continue_tx(struct net_device *dev, int bufnum)
1da177e4 LT	511	{
454d7c9b	512	struct arcnet_local *lp = netdev_priv(dev);
1da177e4 LT	513	struct Outgoing *out = &lp->outgoing;
	514	struct arc_hardware *hard = &out->pkt->hard;
	515	struct arc_rfc1201 soft = &out->pkt->soft.rfc1201, newsoft;
	516	int maxsegsize = XMTU - RFC1201_HDR_SIZE;
	517	int seglen;
	518
a34c0932 JP	519	arc_printk(D_DURING, dev,
	520	"rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n",
	521	out->segnum, out->numsegs, soft->sequence);
1da177e4 LT	522
	523	/* the "new" soft header comes right before the data chunk */
	524	newsoft = (struct arc_rfc1201 *)
	525	(out->pkt->soft.raw + out->length - out->dataleft);
	526
	527	if (!out->segnum) /* first packet; newsoft == soft */
	528	newsoft->split_flag = ((out->numsegs - 2) << 1) \| 1;
	529	else {
	530	newsoft->split_flag = out->segnum << 1;
	531	newsoft->proto = soft->proto;
	532	newsoft->sequence = soft->sequence;
	533	}
	534
	535	seglen = maxsegsize;
	536	if (seglen > out->dataleft)
	537	seglen = out->dataleft;
	538	out->dataleft -= seglen;
	539
	540	load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum);
	541
	542	out->segnum++;
	543	if (out->segnum >= out->numsegs)
	544	return 1;
	545	else
	546	return 0;
	547	}