2 * Linux ARCnet driver - RFC1201 (standard) packet encapsulation
4 * Written 1994-1999 by Avery Pennarun.
5 * Derived from skeleton.c by Donald Becker.
7 * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
8 * for sponsoring the further development of this driver.
10 * **********************
12 * The original copyright of skeleton.c was as follows:
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.
20 * **********************
22 * For more details, see drivers/net/arcnet.c
24 * **********************
26 #include <linux/gfp.h>
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/if_arp.h>
30 #include <linux/netdevice.h>
31 #include <linux/skbuff.h>
32 #include <linux/arcdevice.h>
34 MODULE_LICENSE("GPL");
35 #define VERSION "arcnet: RFC1201 \"standard\" (`a') encapsulation support loaded.\n"
37 static __be16 type_trans(struct sk_buff *skb, struct net_device *dev);
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,
44 static int continue_tx(struct net_device *dev, int bufnum);
46 static struct ArcProto rfc1201_proto = {
48 .mtu = 1500, /* could be more, but some receivers can't handle it... */
49 .is_ip = 1, /* This is for sending IP and ARP packages */
51 .build_header = build_header,
52 .prepare_tx = prepare_tx,
53 .continue_tx = continue_tx,
57 static int __init arcnet_rfc1201_init(void)
61 arc_proto_map[ARC_P_IP]
62 = arc_proto_map[ARC_P_IPV6]
63 = arc_proto_map[ARC_P_ARP]
64 = arc_proto_map[ARC_P_RARP]
65 = arc_proto_map[ARC_P_IPX]
66 = arc_proto_map[ARC_P_NOVELL_EC]
69 /* if someone else already owns the broadcast, we won't take it */
70 if (arc_bcast_proto == arc_proto_default)
71 arc_bcast_proto = &rfc1201_proto;
76 static void __exit arcnet_rfc1201_exit(void)
78 arcnet_unregister_proto(&rfc1201_proto);
81 module_init(arcnet_rfc1201_init);
82 module_exit(arcnet_rfc1201_exit);
84 /* Determine a packet's protocol ID.
86 * With ARCnet we have to convert everything to Ethernet-style stuff.
88 static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
90 struct archdr *pkt = (struct archdr *)skb->data;
91 struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
92 int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
94 /* Pull off the arcnet header. */
95 skb_reset_mac_header(skb);
96 skb_pull(skb, hdr_size);
98 if (pkt->hard.dest == 0) {
99 skb->pkt_type = PACKET_BROADCAST;
100 } else if (dev->flags & IFF_PROMISC) {
101 /* if we're not sending to ourselves :) */
102 if (pkt->hard.dest != dev->dev_addr[0])
103 skb->pkt_type = PACKET_OTHERHOST;
105 /* now return the protocol number */
106 switch (soft->proto) {
108 return htons(ETH_P_IP);
110 return htons(ETH_P_IPV6);
112 return htons(ETH_P_ARP);
114 return htons(ETH_P_RARP);
117 case ARC_P_NOVELL_EC:
118 return htons(ETH_P_802_3);
120 dev->stats.rx_errors++;
121 dev->stats.rx_crc_errors++;
125 return htons(ETH_P_IP);
128 /* packet receiver */
129 static void rx(struct net_device *dev, int bufnum,
130 struct archdr *pkthdr, int length)
132 struct arcnet_local *lp = netdev_priv(dev);
134 struct archdr *pkt = pkthdr;
135 struct arc_rfc1201 *soft = &pkthdr->soft.rfc1201;
136 int saddr = pkt->hard.source, ofs;
137 struct Incoming *in = &lp->rfc1201.incoming[saddr];
139 arc_printk(D_DURING, dev, "it's an RFC1201 packet (length=%d)\n",
147 if (soft->split_flag == 0xFF) { /* Exception Packet */
148 if (length >= 4 + RFC1201_HDR_SIZE) {
149 arc_printk(D_DURING, dev, "compensating for exception packet\n");
151 arc_printk(D_EXTRA, dev, "short RFC1201 exception packet from %02Xh",
156 /* skip over 4-byte junkola */
159 lp->hw.copy_from_card(dev, bufnum, 512 - length,
160 soft, sizeof(pkt->soft));
162 if (!soft->split_flag) { /* not split */
163 arc_printk(D_RX, dev, "incoming is not split (splitflag=%d)\n",
166 if (in->skb) { /* already assembling one! */
167 arc_printk(D_EXTRA, dev, "aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n",
168 in->sequence, soft->split_flag,
170 lp->rfc1201.aborted_seq = soft->sequence;
171 dev_kfree_skb_irq(in->skb);
172 dev->stats.rx_errors++;
173 dev->stats.rx_missed_errors++;
176 in->sequence = soft->sequence;
178 skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
180 arc_printk(D_NORMAL, dev, "Memory squeeze, dropping packet\n");
181 dev->stats.rx_dropped++;
184 skb_put(skb, length + ARC_HDR_SIZE);
187 pkt = (struct archdr *)skb->data;
188 soft = &pkt->soft.rfc1201;
190 /* up to sizeof(pkt->soft) has already been copied from the card */
191 memcpy(pkt, pkthdr, sizeof(struct archdr));
192 if (length > sizeof(pkt->soft))
193 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
194 pkt->soft.raw + sizeof(pkt->soft),
195 length - sizeof(pkt->soft));
197 /* ARP packets have problems when sent from some DOS systems:
198 * the source address is always 0!
199 * So we take the hardware source addr (which is impossible
200 * to fumble) and insert it ourselves.
202 if (soft->proto == ARC_P_ARP) {
203 struct arphdr *arp = (struct arphdr *)soft->payload;
205 /* make sure addresses are the right length */
206 if (arp->ar_hln == 1 && arp->ar_pln == 4) {
207 uint8_t *cptr = (uint8_t *)arp + sizeof(struct arphdr);
209 if (!*cptr) { /* is saddr = 00? */
210 arc_printk(D_EXTRA, dev,
211 "ARP source address was 00h, set to %02Xh\n",
213 dev->stats.rx_crc_errors++;
216 arc_printk(D_DURING, dev, "ARP source address (%Xh) is fine.\n",
220 arc_printk(D_NORMAL, dev, "funny-shaped ARP packet. (%Xh, %Xh)\n",
221 arp->ar_hln, arp->ar_pln);
222 dev->stats.rx_errors++;
223 dev->stats.rx_crc_errors++;
227 arcnet_dump_skb(dev, skb, "rx");
229 skb->protocol = type_trans(skb, dev);
231 } else { /* split packet */
232 /* NOTE: MSDOS ARP packet correction should only need to
233 * apply to unsplit packets, since ARP packets are so short.
235 * My interpretation of the RFC1201 document is that if a
236 * packet is received out of order, the entire assembly
237 * process should be aborted.
239 * The RFC also mentions "it is possible for successfully
240 * received packets to be retransmitted." As of 0.40 all
241 * previously received packets are allowed, not just the
244 * We allow multiple assembly processes, one for each
245 * ARCnet card possible on the network.
246 * Seems rather like a waste of memory, but there's no
247 * other way to be reliable.
250 arc_printk(D_RX, dev, "packet is split (splitflag=%d, seq=%d)\n",
251 soft->split_flag, in->sequence);
253 if (in->skb && in->sequence != soft->sequence) {
254 arc_printk(D_EXTRA, dev, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n",
255 saddr, in->sequence, soft->sequence,
257 dev_kfree_skb_irq(in->skb);
259 dev->stats.rx_errors++;
260 dev->stats.rx_missed_errors++;
261 in->lastpacket = in->numpackets = 0;
263 if (soft->split_flag & 1) { /* first packet in split */
264 arc_printk(D_RX, dev, "brand new splitpacket (splitflag=%d)\n",
266 if (in->skb) { /* already assembling one! */
267 arc_printk(D_EXTRA, dev, "aborting previous (seq=%d) assembly (splitflag=%d, seq=%d)\n",
268 in->sequence, soft->split_flag,
270 dev->stats.rx_errors++;
271 dev->stats.rx_missed_errors++;
272 dev_kfree_skb_irq(in->skb);
274 in->sequence = soft->sequence;
275 in->numpackets = ((unsigned)soft->split_flag >> 1) + 2;
278 if (in->numpackets > 16) {
279 arc_printk(D_EXTRA, dev, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n",
281 lp->rfc1201.aborted_seq = soft->sequence;
282 dev->stats.rx_errors++;
283 dev->stats.rx_length_errors++;
286 in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE,
289 arc_printk(D_NORMAL, dev, "(split) memory squeeze, dropping packet.\n");
290 lp->rfc1201.aborted_seq = soft->sequence;
291 dev->stats.rx_dropped++;
295 pkt = (struct archdr *)skb->data;
296 soft = &pkt->soft.rfc1201;
298 memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
299 skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
301 soft->split_flag = 0; /* end result won't be split */
302 } else { /* not first packet */
303 int packetnum = ((unsigned)soft->split_flag >> 1) + 1;
305 /* if we're not assembling, there's no point trying to
309 if (lp->rfc1201.aborted_seq != soft->sequence) {
310 arc_printk(D_EXTRA, dev, "can't continue split without starting first! (splitflag=%d, seq=%d, aborted=%d)\n",
313 lp->rfc1201.aborted_seq);
314 dev->stats.rx_errors++;
315 dev->stats.rx_missed_errors++;
320 if (packetnum != in->lastpacket) { /* not the right flag! */
321 /* harmless duplicate? ignore. */
322 if (packetnum <= in->lastpacket - 1) {
323 arc_printk(D_EXTRA, dev, "duplicate splitpacket ignored! (splitflag=%d)\n",
325 dev->stats.rx_errors++;
326 dev->stats.rx_frame_errors++;
329 /* "bad" duplicate, kill reassembly */
330 arc_printk(D_EXTRA, dev, "out-of-order splitpacket, reassembly (seq=%d) aborted (splitflag=%d, seq=%d)\n",
331 in->sequence, soft->split_flag,
333 lp->rfc1201.aborted_seq = soft->sequence;
334 dev_kfree_skb_irq(in->skb);
336 dev->stats.rx_errors++;
337 dev->stats.rx_missed_errors++;
338 in->lastpacket = in->numpackets = 0;
341 pkt = (struct archdr *)in->skb->data;
342 soft = &pkt->soft.rfc1201;
347 lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE,
348 skb->data + skb->len,
349 length - RFC1201_HDR_SIZE);
350 skb_put(skb, length - RFC1201_HDR_SIZE);
353 if (in->lastpacket == in->numpackets) {
355 in->lastpacket = in->numpackets = 0;
357 arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (unsplit)\n",
358 skb->len, pkt->hard.source);
359 arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (split)\n",
360 skb->len, pkt->hard.source);
362 arcnet_dump_skb(dev, skb, "rx");
364 skb->protocol = type_trans(skb, dev);
370 /* Create the ARCnet hard/soft headers for RFC1201. */
371 static int build_header(struct sk_buff *skb, struct net_device *dev,
372 unsigned short type, uint8_t daddr)
374 struct arcnet_local *lp = netdev_priv(dev);
375 int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
376 struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
377 struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
379 /* set the protocol ID according to RFC1201 */
382 soft->proto = ARC_P_IP;
385 soft->proto = ARC_P_IPV6;
388 soft->proto = ARC_P_ARP;
391 soft->proto = ARC_P_RARP;
396 soft->proto = ARC_P_IPX;
399 soft->proto = ARC_P_ATALK;
402 arc_printk(D_NORMAL, dev, "RFC1201: I don't understand protocol %d (%Xh)\n",
404 dev->stats.tx_errors++;
405 dev->stats.tx_aborted_errors++;
409 /* Set the source hardware address.
411 * This is pretty pointless for most purposes, but it can help in
412 * debugging. ARCnet does not allow us to change the source address
413 * in the actual packet sent.
415 pkt->hard.source = *dev->dev_addr;
417 soft->sequence = htons(lp->rfc1201.sequence++);
418 soft->split_flag = 0; /* split packets are done elsewhere */
420 /* see linux/net/ethernet/eth.c to see where I got the following */
422 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
423 /* FIXME: fill in the last byte of the dest ipaddr here
424 * to better comply with RFC1051 in "noarp" mode.
425 * For now, always broadcasting will probably at least get
426 * packets sent out :)
431 /* otherwise, drop in the dest address */
432 pkt->hard.dest = daddr;
436 static void load_pkt(struct net_device *dev, struct arc_hardware *hard,
437 struct arc_rfc1201 *soft, int softlen, int bufnum)
439 struct arcnet_local *lp = netdev_priv(dev);
442 /* assume length <= XMTU: someone should have handled that by now. */
444 if (softlen > MinTU) {
446 hard->offset[1] = ofs = 512 - softlen;
447 } else if (softlen > MTU) { /* exception packet - add an extra header */
448 struct arc_rfc1201 excsoft;
450 excsoft.proto = soft->proto;
451 excsoft.split_flag = 0xff;
452 excsoft.sequence = htons(0xffff);
456 hard->offset[1] = ofs - RFC1201_HDR_SIZE;
457 lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE,
458 &excsoft, RFC1201_HDR_SIZE);
460 hard->offset[0] = ofs = 256 - softlen;
463 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
464 lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen);
466 lp->lastload_dest = hard->dest;
469 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
472 struct arcnet_local *lp = netdev_priv(dev);
473 const int maxsegsize = XMTU - RFC1201_HDR_SIZE;
474 struct Outgoing *out;
476 arc_printk(D_DURING, dev, "prepare_tx: txbufs=%d/%d/%d\n",
477 lp->next_tx, lp->cur_tx, bufnum);
479 length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
480 pkt->soft.rfc1201.split_flag = 0;
482 /* need to do a split packet? */
486 out->length = length - RFC1201_HDR_SIZE;
487 out->dataleft = lp->outgoing.length;
488 out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize;
491 arc_printk(D_DURING, dev, "rfc1201 prep_tx: ready for %d-segment split (%d bytes, seq=%d)\n",
492 out->numsegs, out->length,
493 pkt->soft.rfc1201.sequence);
495 return 0; /* not done */
497 /* just load the packet into the buffers and send it off */
498 load_pkt(dev, &pkt->hard, &pkt->soft.rfc1201, length, bufnum);
503 static int continue_tx(struct net_device *dev, int bufnum)
505 struct arcnet_local *lp = netdev_priv(dev);
506 struct Outgoing *out = &lp->outgoing;
507 struct arc_hardware *hard = &out->pkt->hard;
508 struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft;
509 int maxsegsize = XMTU - RFC1201_HDR_SIZE;
512 arc_printk(D_DURING, dev,
513 "rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n",
514 out->segnum, out->numsegs, soft->sequence);
516 /* the "new" soft header comes right before the data chunk */
517 newsoft = (struct arc_rfc1201 *)
518 (out->pkt->soft.raw + out->length - out->dataleft);
520 if (!out->segnum) /* first packet; newsoft == soft */
521 newsoft->split_flag = ((out->numsegs - 2) << 1) | 1;
523 newsoft->split_flag = out->segnum << 1;
524 newsoft->proto = soft->proto;
525 newsoft->sequence = soft->sequence;
529 if (seglen > out->dataleft)
530 seglen = out->dataleft;
531 out->dataleft -= seglen;
533 load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum);
536 if (out->segnum >= out->numsegs)