projects / deliverable / linux.git / blob
? search:


4abb20e26eadc8b28fce61d5531b5eef6000df36
[deliverable/linux.git] / drivers / net / arcnet / rfc1201.c
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/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>
33
34 MODULE_LICENSE("GPL");
35 #define VERSION "arcnet: RFC1201 \"standard\" (`a') encapsulation support loaded.\n"
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 .suffix = 'a',
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 */
50 .rx = rx,
51 .build_header = build_header,
52 .prepare_tx = prepare_tx,
53 .continue_tx = continue_tx,
54 .ack_tx = NULL
55 };
56
57 static int __init arcnet_rfc1201_init(void)
58 {
59 printk(VERSION);
60
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]
67 = &rfc1201_proto;
68
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;
72
73 return 0;
74 }
75
76 static void __exit arcnet_rfc1201_exit(void)
77 {
78 arcnet_unregister_proto(&rfc1201_proto);
79 }
80
81 module_init(arcnet_rfc1201_init);
82 module_exit(arcnet_rfc1201_exit);
83
84 /*
85 * Determine a packet's protocol ID.
86 *
87 * With ARCnet we have to convert everything to Ethernet-style stuff.
88 */
89 static __be16 type_trans(struct sk_buff *skb, struct net_device *dev)
90 {
91 struct archdr *pkt = (struct archdr *)skb->data;
92 struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
93 int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
94
95 /* Pull off the arcnet header. */
96 skb_reset_mac_header(skb);
97 skb_pull(skb, hdr_size);
98
99 if (pkt->hard.dest == 0) {
100 skb->pkt_type = PACKET_BROADCAST;
101 } else if (dev->flags & IFF_PROMISC) {
102 /* if we're not sending to ourselves :) */
103 if (pkt->hard.dest != dev->dev_addr[0])
104 skb->pkt_type = PACKET_OTHERHOST;
105 }
106 /* now return the protocol number */
107 switch (soft->proto) {
108 case ARC_P_IP:
109 return htons(ETH_P_IP);
110 case ARC_P_IPV6:
111 return htons(ETH_P_IPV6);
112 case ARC_P_ARP:
113 return htons(ETH_P_ARP);
114 case ARC_P_RARP:
115 return htons(ETH_P_RARP);
116
117 case ARC_P_IPX:
118 case ARC_P_NOVELL_EC:
119 return htons(ETH_P_802_3);
120 default:
121 dev->stats.rx_errors++;
122 dev->stats.rx_crc_errors++;
123 return 0;
124 }
125
126 return htons(ETH_P_IP);
127 }
128
129 /* packet receiver */
130 static void rx(struct net_device *dev, int bufnum,
131 struct archdr *pkthdr, int length)
132 {
133 struct arcnet_local *lp = netdev_priv(dev);
134 struct sk_buff *skb;
135 struct archdr *pkt = pkthdr;
136 struct arc_rfc1201 *soft = &pkthdr->soft.rfc1201;
137 int saddr = pkt->hard.source, ofs;
138 struct Incoming *in = &lp->rfc1201.incoming[saddr];
139
140 BUGMSG(D_DURING, "it's an RFC1201 packet (length=%d)\n", length);
141
142 if (length >= MinTU)
143 ofs = 512 - length;
144 else
145 ofs = 256 - length;
146
147 if (soft->split_flag == 0xFF) { /* Exception Packet */
148 if (length >= 4 + RFC1201_HDR_SIZE) {
149 BUGMSG(D_DURING, "compensating for exception packet\n");
150 } else {
151 BUGMSG(D_EXTRA, "short RFC1201 exception packet from %02Xh",
152 saddr);
153 return;
154 }
155
156 /* skip over 4-byte junkola */
157 length -= 4;
158 ofs += 4;
159 lp->hw.copy_from_card(dev, bufnum, 512 - length,
160 soft, sizeof(pkt->soft));
161 }
162 if (!soft->split_flag) { /* not split */
163 BUGMSG(D_RX, "incoming is not split (splitflag=%d)\n",
164 soft->split_flag);
165
166 if (in->skb) { /* already assembling one! */
167 BUGMSG(D_EXTRA, "aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n",
168 in->sequence, soft->split_flag, soft->sequence);
169 lp->rfc1201.aborted_seq = soft->sequence;
170 dev_kfree_skb_irq(in->skb);
171 dev->stats.rx_errors++;
172 dev->stats.rx_missed_errors++;
173 in->skb = NULL;
174 }
175 in->sequence = soft->sequence;
176
177 skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
178 if (skb == NULL) {
179 BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n");
180 dev->stats.rx_dropped++;
181 return;
182 }
183 skb_put(skb, length + ARC_HDR_SIZE);
184 skb->dev = dev;
185
186 pkt = (struct archdr *)skb->data;
187 soft = &pkt->soft.rfc1201;
188
189 /* up to sizeof(pkt->soft) has already been copied from the card */
190 memcpy(pkt, pkthdr, sizeof(struct archdr));
191 if (length > sizeof(pkt->soft))
192 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
193 pkt->soft.raw + sizeof(pkt->soft),
194 length - sizeof(pkt->soft));
195
196 /*
197 * ARP packets have problems when sent from some DOS systems: the
198 * source address is always 0! So we take the hardware source addr
199 * (which is impossible to fumble) and insert it ourselves.
200 */
201 if (soft->proto == ARC_P_ARP) {
202 struct arphdr *arp = (struct arphdr *)soft->payload;
203
204 /* make sure addresses are the right length */
205 if (arp->ar_hln == 1 && arp->ar_pln == 4) {
206 uint8_t *cptr = (uint8_t *)arp + sizeof(struct arphdr);
207
208 if (!*cptr) { /* is saddr = 00? */
209 BUGMSG(D_EXTRA,
210 "ARP source address was 00h, set to %02Xh.\n",
211 saddr);
212 dev->stats.rx_crc_errors++;
213 *cptr = saddr;
214 } else {
215 BUGMSG(D_DURING, "ARP source address (%Xh) is fine.\n",
216 *cptr);
217 }
218 } else {
219 BUGMSG(D_NORMAL, "funny-shaped ARP packet. (%Xh, %Xh)\n",
220 arp->ar_hln, arp->ar_pln);
221 dev->stats.rx_errors++;
222 dev->stats.rx_crc_errors++;
223 }
224 }
225 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
226
227 skb->protocol = type_trans(skb, dev);
228 netif_rx(skb);
229 } else { /* split packet */
230 /*
231 * NOTE: MSDOS ARP packet correction should only need to apply to
232 * unsplit packets, since ARP packets are so short.
233 *
234 * My interpretation of the RFC1201 document is that if a packet is
235 * received out of order, the entire assembly process should be
236 * aborted.
237 *
238 * The RFC also mentions "it is possible for successfully received
239 * packets to be retransmitted." As of 0.40 all previously received
240 * packets are allowed, not just the most recent one.
241 *
242 * We allow multiple assembly processes, one for each ARCnet card
243 * possible on the network. Seems rather like a waste of memory,
244 * but there's no other way to be reliable.
245 */
246
247 BUGMSG(D_RX, "packet is split (splitflag=%d, seq=%d)\n",
248 soft->split_flag, in->sequence);
249
250 if (in->skb && in->sequence != soft->sequence) {
251 BUGMSG(D_EXTRA, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n",
252 saddr, in->sequence, soft->sequence,
253 soft->split_flag);
254 dev_kfree_skb_irq(in->skb);
255 in->skb = NULL;
256 dev->stats.rx_errors++;
257 dev->stats.rx_missed_errors++;
258 in->lastpacket = in->numpackets = 0;
259 }
260 if (soft->split_flag & 1) { /* first packet in split */
261 BUGMSG(D_RX, "brand new splitpacket (splitflag=%d)\n",
262 soft->split_flag);
263 if (in->skb) { /* already assembling one! */
264 BUGMSG(D_EXTRA, "aborting previous (seq=%d) assembly "
265 "(splitflag=%d, seq=%d)\n",
266 in->sequence, soft->split_flag,
267 soft->sequence);
268 dev->stats.rx_errors++;
269 dev->stats.rx_missed_errors++;
270 dev_kfree_skb_irq(in->skb);
271 }
272 in->sequence = soft->sequence;
273 in->numpackets = ((unsigned)soft->split_flag >> 1) + 2;
274 in->lastpacket = 1;
275
276 if (in->numpackets > 16) {
277 BUGMSG(D_EXTRA, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n",
278 soft->split_flag);
279 lp->rfc1201.aborted_seq = soft->sequence;
280 dev->stats.rx_errors++;
281 dev->stats.rx_length_errors++;
282 return;
283 }
284 in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE,
285 GFP_ATOMIC);
286 if (skb == NULL) {
287 BUGMSG(D_NORMAL, "(split) memory squeeze, dropping packet.\n");
288 lp->rfc1201.aborted_seq = soft->sequence;
289 dev->stats.rx_dropped++;
290 return;
291 }
292 skb->dev = dev;
293 pkt = (struct archdr *)skb->data;
294 soft = &pkt->soft.rfc1201;
295
296 memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
297 skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE);
298
299 soft->split_flag = 0; /* end result won't be split */
300 } else { /* not first packet */
301 int packetnum = ((unsigned)soft->split_flag >> 1) + 1;
302
303 /*
304 * if we're not assembling, there's no point trying to
305 * continue.
306 */
307 if (!in->skb) {
308 if (lp->rfc1201.aborted_seq != soft->sequence) {
309 BUGMSG(D_EXTRA, "can't continue split without starting "
310 "first! (splitflag=%d, seq=%d, aborted=%d)\n",
311 soft->split_flag, soft->sequence,
312 lp->rfc1201.aborted_seq);
313 dev->stats.rx_errors++;
314 dev->stats.rx_missed_errors++;
315 }
316 return;
317 }
318 in->lastpacket++;
319 if (packetnum != in->lastpacket) { /* not the right flag! */
320 /* harmless duplicate? ignore. */
321 if (packetnum <= in->lastpacket - 1) {
322 BUGMSG(D_EXTRA, "duplicate splitpacket ignored! (splitflag=%d)\n",
323 soft->split_flag);
324 dev->stats.rx_errors++;
325 dev->stats.rx_frame_errors++;
326 return;
327 }
328 /* "bad" duplicate, kill reassembly */
329 BUGMSG(D_EXTRA, "out-of-order splitpacket, reassembly "
330 "(seq=%d) aborted (splitflag=%d, seq=%d)\n",
331 in->sequence, soft->split_flag, soft->sequence);
332 lp->rfc1201.aborted_seq = soft->sequence;
333 dev_kfree_skb_irq(in->skb);
334 in->skb = NULL;
335 dev->stats.rx_errors++;
336 dev->stats.rx_missed_errors++;
337 in->lastpacket = in->numpackets = 0;
338 return;
339 }
340 pkt = (struct archdr *)in->skb->data;
341 soft = &pkt->soft.rfc1201;
342 }
343
344 skb = in->skb;
345
346 lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE,
347 skb->data + skb->len,
348 length - RFC1201_HDR_SIZE);
349 skb_put(skb, length - RFC1201_HDR_SIZE);
350
351 /* are we done? */
352 if (in->lastpacket == in->numpackets) {
353 in->skb = NULL;
354 in->lastpacket = in->numpackets = 0;
355
356 BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (unsplit)\n",
357 skb->len, pkt->hard.source);
358 BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (split)\n",
359 skb->len, pkt->hard.source);
360 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx");
361
362 skb->protocol = type_trans(skb, dev);
363 netif_rx(skb);
364 }
365 }
366 }
367
368 /* Create the ARCnet hard/soft headers for RFC1201. */
369 static int build_header(struct sk_buff *skb, struct net_device *dev,
370 unsigned short type, uint8_t daddr)
371 {
372 struct arcnet_local *lp = netdev_priv(dev);
373 int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
374 struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
375 struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
376
377 /* set the protocol ID according to RFC1201 */
378 switch (type) {
379 case ETH_P_IP:
380 soft->proto = ARC_P_IP;
381 break;
382 case ETH_P_IPV6:
383 soft->proto = ARC_P_IPV6;
384 break;
385 case ETH_P_ARP:
386 soft->proto = ARC_P_ARP;
387 break;
388 case ETH_P_RARP:
389 soft->proto = ARC_P_RARP;
390 break;
391 case ETH_P_IPX:
392 case ETH_P_802_3:
393 case ETH_P_802_2:
394 soft->proto = ARC_P_IPX;
395 break;
396 case ETH_P_ATALK:
397 soft->proto = ARC_P_ATALK;
398 break;
399 default:
400 BUGMSG(D_NORMAL, "RFC1201: I don't understand protocol %d (%Xh)\n",
401 type, type);
402 dev->stats.tx_errors++;
403 dev->stats.tx_aborted_errors++;
404 return 0;
405 }
406
407 /*
408 * Set the source hardware address.
409 *
410 * This is pretty pointless for most purposes, but it can help in
411 * debugging. ARCnet does not allow us to change the source address in
412 * the actual packet sent)
413 */
414 pkt->hard.source = *dev->dev_addr;
415
416 soft->sequence = htons(lp->rfc1201.sequence++);
417 soft->split_flag = 0; /* split packets are done elsewhere */
418
419 /* see linux/net/ethernet/eth.c to see where I got the following */
420
421 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
422 /*
423 * FIXME: fill in the last byte of the dest ipaddr here to better
424 * comply with RFC1051 in "noarp" mode. For now, always broadcasting
425 * will probably at least get packets sent out :)
426 */
427 pkt->hard.dest = 0;
428 return hdr_size;
429 }
430 /* otherwise, drop in the dest address */
431 pkt->hard.dest = daddr;
432 return hdr_size;
433 }
434
435 static void load_pkt(struct net_device *dev, struct arc_hardware *hard,
436 struct arc_rfc1201 *soft, int softlen, int bufnum)
437 {
438 struct arcnet_local *lp = netdev_priv(dev);
439 int ofs;
440
441 /* assume length <= XMTU: someone should have handled that by now. */
442
443 if (softlen > MinTU) {
444 hard->offset[0] = 0;
445 hard->offset[1] = ofs = 512 - softlen;
446 } else if (softlen > MTU) { /* exception packet - add an extra header */
447 struct arc_rfc1201 excsoft;
448
449 excsoft.proto = soft->proto;
450 excsoft.split_flag = 0xff;
451 excsoft.sequence = htons(0xffff);
452
453 hard->offset[0] = 0;
454 ofs = 512 - softlen;
455 hard->offset[1] = ofs - RFC1201_HDR_SIZE;
456 lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE,
457 &excsoft, RFC1201_HDR_SIZE);
458 } else {
459 hard->offset[0] = ofs = 256 - softlen;
460 }
461
462 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
463 lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen);
464
465 lp->lastload_dest = hard->dest;
466 }
467
468 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
469 int bufnum)
470 {
471 struct arcnet_local *lp = netdev_priv(dev);
472 const int maxsegsize = XMTU - RFC1201_HDR_SIZE;
473 struct Outgoing *out;
474
475 BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n",
476 lp->next_tx, lp->cur_tx, bufnum);
477
478 length -= ARC_HDR_SIZE; /* hard header is not included in packet length */
479 pkt->soft.rfc1201.split_flag = 0;
480
481 /* need to do a split packet? */
482 if (length > XMTU) {
483 out = &lp->outgoing;
484
485 out->length = length - RFC1201_HDR_SIZE;
486 out->dataleft = lp->outgoing.length;
487 out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize;
488 out->segnum = 0;
489
490 BUGMSG(D_DURING, "rfc1201 prep_tx: ready for %d-segment split "
491 "(%d bytes, seq=%d)\n", out->numsegs, out->length,
492 pkt->soft.rfc1201.sequence);
493
494 return 0; /* not done */
495 }
496 /* just load the packet into the buffers and send it off */
497 load_pkt(dev, &pkt->hard, &pkt->soft.rfc1201, length, bufnum);
498
499 return 1; /* done */
500 }
501
502 static int continue_tx(struct net_device *dev, int bufnum)
503 {
504 struct arcnet_local *lp = netdev_priv(dev);
505 struct Outgoing *out = &lp->outgoing;
506 struct arc_hardware *hard = &out->pkt->hard;
507 struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft;
508 int maxsegsize = XMTU - RFC1201_HDR_SIZE;
509 int seglen;
510
511 BUGMSG(D_DURING,
512 "rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n",
513 out->segnum, out->numsegs, soft->sequence);
514
515 /* the "new" soft header comes right before the data chunk */
516 newsoft = (struct arc_rfc1201 *)
517 (out->pkt->soft.raw + out->length - out->dataleft);
518
519 if (!out->segnum) /* first packet; newsoft == soft */
520 newsoft->split_flag = ((out->numsegs - 2) << 1) | 1;
521 else {
522 newsoft->split_flag = out->segnum << 1;
523 newsoft->proto = soft->proto;
524 newsoft->sequence = soft->sequence;
525 }
526
527 seglen = maxsegsize;
528 if (seglen > out->dataleft)
529 seglen = out->dataleft;
530 out->dataleft -= seglen;
531
532 load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum);
533
534 out->segnum++;
535 if (out->segnum >= out->numsegs)
536 return 1;
537 else
538 return 0;
539 }
Linux kernel - Deliverables
This page took 0.048149 seconds and 4 git commands to generate.