1 /*
2 * Linux ARCnet driver - RFC1201 (standard) packet encapsulation
3 *
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>
27 #include <linux/init.h>
28 #include <linux/if_arp.h>
29 #include <linux/netdevice.h>
30 #include <linux/skbuff.h>
31 #include <linux/arcdevice.h>
32
33 MODULE_LICENSE("GPL");
34 #define VERSION "arcnet: RFC1201 \"standard\" (`a') encapsulation support loaded.\n"
35
36
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,
43 int bufnum);
44 static int continue_tx(struct net_device *dev, int bufnum);
45
46 static struct ArcProto rfc1201_proto =
47 {
48 .suffix = 'a',
49 .mtu = 1500, /* could be more, but some receivers can't handle it... */
50 .is_ip = 1, /* This is for sending IP and ARP packages */
51 .rx = rx,
52 .build_header = build_header,
53 .prepare_tx = prepare_tx,
54 .continue_tx = continue_tx,
55 .ack_tx = NULL
56 };
57
58
59 static int __init arcnet_rfc1201_init(void)
60 {
61 printk(VERSION);
62
63 arc_proto_map[ARC_P_IP]
64 = arc_proto_map[ARC_P_IPV6]
65 = arc_proto_map[ARC_P_ARP]
66 = arc_proto_map[ARC_P_RARP]
67 = arc_proto_map[ARC_P_IPX]
68 = arc_proto_map[ARC_P_NOVELL_EC]
69 = &rfc1201_proto;
70
71 /* if someone else already owns the broadcast, we won't take it */
72 if (arc_bcast_proto == arc_proto_default)
73 arc_bcast_proto = &rfc1201_proto;
74
75 return 0;
76 }
77
78 static void __exit arcnet_rfc1201_exit(void)
79 {
80 arcnet_unregister_proto(&rfc1201_proto);
81 }
82
83 module_init(arcnet_rfc1201_init);
84 module_exit(arcnet_rfc1201_exit);
85
86 /*
87 * Determine a packet's protocol ID.
88 *
89 * With ARCnet we have to convert everything to Ethernet-style stuff.
90 */
91 static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
92 {
93 struct archdr *pkt = (struct archdr *) skb->data;
94 struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
95 int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
96
97 /* Pull off the arcnet header. */
98 skb_reset_mac_header(skb);
99 skb_pull(skb, hdr_size);
100
101 if (pkt->hard.dest == 0)
102 skb->pkt_type = PACKET_BROADCAST;
103 else if (dev->flags & IFF_PROMISC) {
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:
123 dev->stats.rx_errors++;
124 dev->stats.rx_crc_errors++;
125 return 0;
126 }
127
128 return htons(ETH_P_IP);
129 }
130
131
132 /* packet receiver */
133 static void rx(struct net_device *dev, int bufnum,
134 struct archdr *pkthdr, int length)
135 {
136 struct arcnet_local *lp = netdev_priv(dev);
137 struct sk_buff *skb;
138 struct archdr *pkt = pkthdr;
139 struct arc_rfc1201 *soft = &pkthdr->soft.rfc1201;
140 int saddr = pkt->hard.source, ofs;
141 struct Incoming *in = &lp->rfc1201.incoming[saddr];
142
143 BUGMSG(D_DURING, "it's an RFC1201 packet (length=%d)\n", length);
144
145 if (length >= MinTU)
146 ofs = 512 - length;
147 else
148 ofs = 256 - length;
149
150 if (soft->split_flag == 0xFF) { /* Exception Packet */
151 if (length >= 4 + RFC1201_HDR_SIZE)
152 BUGMSG(D_DURING, "compensating for exception packet\n");
153 else {
154 BUGMSG(D_EXTRA, "short RFC1201 exception packet from %02Xh",
155 saddr);
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 */
166 BUGMSG(D_RX, "incoming is not split (splitflag=%d)\n",
167 soft->split_flag);
168
169 if (in->skb) { /* already assembling one! */
170 BUGMSG(D_EXTRA, "aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n",
171 in->sequence, soft->split_flag, soft->sequence);
172 lp->rfc1201.aborted_seq = soft->sequence;
173 dev_kfree_skb_irq(in->skb);
174 dev->stats.rx_errors++;
175 dev->stats.rx_missed_errors++;
176 in->skb = NULL;
177 }
178 in->sequence = soft->sequence;
179
180 skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
181 if (skb == NULL) {
182 BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
183 dev->stats.rx_dropped++;
184 return;
185 }
186 skb_put(skb, length + ARC_HDR_SIZE);
187 skb->dev = dev;
188
189 pkt = (struct archdr *) skb->data;
190 soft = &pkt->soft.rfc1201;
191
192 /* up to sizeof(pkt->soft) has already been copied from the card */
193 memcpy(pkt, pkthdr, sizeof(struct archdr));
194 if (length > sizeof(pkt->soft))
195 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
196 pkt->soft.raw + sizeof(pkt->soft),
197 length - sizeof(pkt->soft));
198
199 /*
200 * ARP packets have problems when sent from some DOS systems: the
201 * source address is always 0! So we take the hardware source addr
202 * (which is impossible to fumble) and insert it ourselves.
203 */
204 if (soft->proto == ARC_P_ARP) {
205 struct arphdr *arp = (struct arphdr *) soft->payload;
206
207 /* make sure addresses are the right length */
208 if (arp->ar_hln == 1 && arp->ar_pln == 4) {
209 uint8_t *cptr = (uint8_t *) arp + sizeof(struct arphdr);
210
211 if (!*cptr) { /* is saddr = 00? */
212 BUGMSG(D_EXTRA,
213 "ARP source address was 00h, set to %02Xh.\n",
214 saddr);
215 dev->stats.rx_crc_errors++;
216 *cptr = saddr;
217 } else {
218 BUGMSG(D_DURING, "ARP source address (%Xh) is fine.\n",
219 *cptr);
220 }
221 } else {
222 BUGMSG(D_NORMAL, "funny-shaped ARP packet. (%Xh, %Xh)\n",
223 arp->ar_hln, arp->ar_pln);
224 dev->stats.rx_errors++;
225 dev->stats.rx_crc_errors++;
226 }
227 }
228 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
229
230 skb->protocol = type_trans(skb, dev);
231 netif_rx(skb);
232 } else { /* split packet */
233 /*
234 * NOTE: MSDOS ARP packet correction should only need to apply to
235 * unsplit packets, since ARP packets are so short.
236 *
237 * My interpretation of the RFC1201 document is that if a packet is
238 * received out of order, the entire assembly process should be
239 * aborted.
240 *
241 * The RFC also mentions "it is possible for successfully received
242 * packets to be retransmitted." As of 0.40 all previously received
243 * packets are allowed, not just the most recent one.
244 *
245 * We allow multiple assembly processes, one for each ARCnet card
246 * possible on the network. Seems rather like a waste of memory,
247 * but there's no other way to be reliable.
248 */
249
250 BUGMSG(D_RX, "packet is split (splitflag=%d, seq=%d)\n",
251 soft->split_flag, in->sequence);
252
253 if (in->skb && in->sequence != soft->sequence) {
254 BUGMSG(D_EXTRA, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n",
255 saddr, in->sequence, soft->sequence,
256 soft->split_flag);
257 dev_kfree_skb_irq(in->skb);
258 in->skb = NULL;
259 dev->stats.rx_errors++;
260 dev->stats.rx_missed_errors++;
261 in->lastpacket = in->numpackets = 0;
262 }
263 if (soft->split_flag & 1) { /* first packet in split */
264 BUGMSG(D_RX, "brand new splitpacket (splitflag=%d)\n",
265 soft->split_flag);
266 if (in->skb) { /* already assembling one! */
267 BUGMSG(D_EXTRA, "aborting previous (seq=%d) assembly "
268 "(splitflag=%d, seq=%d)\n",
269 in->sequence, soft->split_flag,
270 soft->sequence);
271 dev->stats.rx_errors++;
272 dev->stats.rx_missed_errors++;
273 dev_kfree_skb_irq(in->skb);
274 }
275 in->sequence = soft->sequence;
276 in->numpackets = ((unsigned) soft->split_flag >> 1) + 2;
277 in->lastpacket = 1;
278
279 if (in->numpackets > 16) {
280 BUGMSG(D_EXTRA, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n",
281 soft->split_flag);
282 lp->rfc1201.aborted_seq = soft->sequence;
283 dev->stats.rx_errors++;
284 dev->stats.rx_length_errors++;
285 return;
286 }
287 in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE,
288 GFP_ATOMIC);
289 if (skb == NULL) {
290 BUGMSG(D_NORMAL, "(split) memory squeeze, dropping packet.\n");
291 lp->rfc1201.aborted_seq = soft->sequence;
292 dev->stats.rx_dropped++;
293 return;
294 }
295 skb->dev = dev;
296 pkt = (struct archdr *) skb->data;
297 soft = &pkt->soft.rfc1201;
298
299 memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
300 skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
301
302 soft->split_flag = 0; /* end result won't be split */
303 } else { /* not first packet */
304 int packetnum = ((unsigned) soft->split_flag >> 1) + 1;
305
306 /*
307 * if we're not assembling, there's no point trying to
308 * continue.
309 */
310 if (!in->skb) {
311 if (lp->rfc1201.aborted_seq != soft->sequence) {
312 BUGMSG(D_EXTRA, "can't continue split without starting "
313 "first! (splitflag=%d, seq=%d, aborted=%d)\n",
314 soft->split_flag, soft->sequence,
315 lp->rfc1201.aborted_seq);
316 dev->stats.rx_errors++;
317 dev->stats.rx_missed_errors++;
318 }
319 return;
320 }
321 in->lastpacket++;
322 if (packetnum != in->lastpacket) { /* not the right flag! */
323 /* harmless duplicate? ignore. */
324 if (packetnum <= in->lastpacket - 1) {
325 BUGMSG(D_EXTRA, "duplicate splitpacket ignored! (splitflag=%d)\n",
326 soft->split_flag);
327 dev->stats.rx_errors++;
328 dev->stats.rx_frame_errors++;
329 return;
330 }
331 /* "bad" duplicate, kill reassembly */
332 BUGMSG(D_EXTRA, "out-of-order splitpacket, reassembly "
333 "(seq=%d) aborted (splitflag=%d, seq=%d)\n",
334 in->sequence, soft->split_flag, soft->sequence);
335 lp->rfc1201.aborted_seq = soft->sequence;
336 dev_kfree_skb_irq(in->skb);
337 in->skb = NULL;
338 dev->stats.rx_errors++;
339 dev->stats.rx_missed_errors++;
340 in->lastpacket = in->numpackets = 0;
341 return;
342 }
343 pkt = (struct archdr *) in->skb->data;
344 soft = &pkt->soft.rfc1201;
345 }
346
347 skb = in->skb;
348
349 lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE,
350 skb->data + skb->len,
351 length - RFC1201_HDR_SIZE);
352 skb_put(skb, length - RFC1201_HDR_SIZE);
353
354 /* are we done? */
355 if (in->lastpacket == in->numpackets) {
356 in->skb = NULL;
357 in->lastpacket = in->numpackets = 0;
358
359 BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (unsplit)\n",
360 skb->len, pkt->hard.source);
361 BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (split)\n",
362 skb->len, pkt->hard.source);
363 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
364
365 skb->protocol = type_trans(skb, dev);
366 netif_rx(skb);
367 }
368 }
369 }
370
371
372 /* Create the ARCnet hard/soft headers for RFC1201. */
373 static int build_header(struct sk_buff *skb, struct net_device *dev,
374 unsigned short type, uint8_t daddr)
375 {
376 struct arcnet_local *lp = netdev_priv(dev);
377 int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
378 struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size);
379 struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
380
381 /* set the protocol ID according to RFC1201 */
382 switch (type) {
383 case ETH_P_IP:
384 soft->proto = ARC_P_IP;
385 break;
386 case ETH_P_IPV6:
387 soft->proto = ARC_P_IPV6;
388 break;
389 case ETH_P_ARP:
390 soft->proto = ARC_P_ARP;
391 break;
392 case ETH_P_RARP:
393 soft->proto = ARC_P_RARP;
394 break;
395 case ETH_P_IPX:
396 case ETH_P_802_3:
397 case ETH_P_802_2:
398 soft->proto = ARC_P_IPX;
399 break;
400 case ETH_P_ATALK:
401 soft->proto = ARC_P_ATALK;
402 break;
403 default:
404 BUGMSG(D_NORMAL, "RFC1201: I don't understand protocol %d (%Xh)\n",
405 type, type);
406 dev->stats.tx_errors++;
407 dev->stats.tx_aborted_errors++;
408 return 0;
409 }
410
411 /*
412 * Set the source hardware address.
413 *
414 * This is pretty pointless for most purposes, but it can help in
415 * debugging. ARCnet does not allow us to change the source address in
416 * the actual packet sent)
417 */
418 pkt->hard.source = *dev->dev_addr;
419
420 soft->sequence = htons(lp->rfc1201.sequence++);
421 soft->split_flag = 0; /* split packets are done elsewhere */
422
423 /* see linux/net/ethernet/eth.c to see where I got the following */
424
425 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
426 /*
427 * FIXME: fill in the last byte of the dest ipaddr here to better
428 * comply with RFC1051 in "noarp" mode. For now, always broadcasting
429 * will probably at least get packets sent out :)
430 */
431 pkt->hard.dest = 0;
432 return hdr_size;
433 }
434 /* otherwise, drop in the dest address */
435 pkt->hard.dest = daddr;
436 return hdr_size;
437 }
438
439
440 static void load_pkt(struct net_device *dev, struct arc_hardware *hard,
441 struct arc_rfc1201 *soft, int softlen, int bufnum)
442 {
443 struct arcnet_local *lp = netdev_priv(dev);
444 int ofs;
445
446 /* assume length <= XMTU: someone should have handled that by now. */
447
448 if (softlen > MinTU) {
449 hard->offset[0] = 0;
450 hard->offset[1] = ofs = 512 - softlen;
451 } else if (softlen > MTU) { /* exception packet - add an extra header */
452 struct arc_rfc1201 excsoft;
453
454 excsoft.proto = soft->proto;
455 excsoft.split_flag = 0xff;
456 excsoft.sequence = htons(0xffff);
457
458 hard->offset[0] = 0;
459 ofs = 512 - softlen;
460 hard->offset[1] = ofs - RFC1201_HDR_SIZE;
461 lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE,
462 &excsoft, RFC1201_HDR_SIZE);
463 } else
464 hard->offset[0] = ofs = 256 - softlen;
465
466 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
467 lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen);
468
469 lp->lastload_dest = hard->dest;
470 }
471
472
473 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
474 int bufnum)
475 {
476 struct arcnet_local *lp = netdev_priv(dev);
477 const int maxsegsize = XMTU - RFC1201_HDR_SIZE;
478 struct Outgoing *out;
479
480
481 BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
482 lp->next_tx, lp->cur_tx, bufnum);
483
484 length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
485 pkt->soft.rfc1201.split_flag = 0;
486
487 /* need to do a split packet? */
488 if (length > XMTU) {
489 out = &lp->outgoing;
490
491 out->length = length - RFC1201_HDR_SIZE;
492 out->dataleft = lp->outgoing.length;
493 out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize;
494 out->segnum = 0;
495
496 BUGMSG(D_DURING, "rfc1201 prep_tx: ready for %d-segment split "
497 "(%d bytes, seq=%d)\n", out->numsegs, out->length,
498 pkt->soft.rfc1201.sequence);
499
500 return 0; /* not done */
501 }
502 /* just load the packet into the buffers and send it off */
503 load_pkt(dev, &pkt->hard, &pkt->soft.rfc1201, length, bufnum);
504
505 return 1; /* done */
506 }
507
508
509 static int continue_tx(struct net_device *dev, int bufnum)
510 {
511 struct arcnet_local *lp = netdev_priv(dev);
512 struct Outgoing *out = &lp->outgoing;
513 struct arc_hardware *hard = &out->pkt->hard;
514 struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft;
515 int maxsegsize = XMTU - RFC1201_HDR_SIZE;
516 int seglen;
517
518 BUGMSG(D_DURING,
519 "rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n",
520 out->segnum, out->numsegs, soft->sequence);
521
522 /* the "new" soft header comes right before the data chunk */
523 newsoft = (struct arc_rfc1201 *)
524 (out->pkt->soft.raw + out->length - out->dataleft);
525
526 if (!out->segnum) /* first packet; newsoft == soft */
527 newsoft->split_flag = ((out->numsegs - 2) << 1) | 1;
528 else {
529 newsoft->split_flag = out->segnum << 1;
530 newsoft->proto = soft->proto;
531 newsoft->sequence = soft->sequence;
532 }
533
534 seglen = maxsegsize;
535 if (seglen > out->dataleft)
536 seglen = out->dataleft;
537 out->dataleft -= seglen;
538
539 load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum);
540
541 out->segnum++;
542 if (out->segnum >= out->numsegs)
543 return 1;
544 else
545 return 0;
546 }
547
|
This page was automatically generated by the
LXR engine.
|