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 | |
27 | #define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt |
28 | |
29 | #include <linux/gfp.h> |
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> |
35 | |
36 | #include "arcdevice.h" |
37 | |
38 | MODULE_DESCRIPTION("ARCNet packet format (RFC 1201) module" ); |
39 | MODULE_LICENSE("GPL" ); |
40 | |
41 | static __be16 type_trans(struct sk_buff *skb, struct net_device *dev); |
42 | static void rx(struct net_device *dev, int bufnum, |
43 | struct archdr *pkthdr, int length); |
44 | static int build_header(struct sk_buff *skb, struct net_device *dev, |
45 | unsigned short type, uint8_t daddr); |
46 | static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, |
47 | int bufnum); |
48 | static int continue_tx(struct net_device *dev, int bufnum); |
49 | |
50 | static struct ArcProto rfc1201_proto = { |
51 | .suffix = 'a', |
52 | .mtu = 1500, /* could be more, but some receivers can't handle it... */ |
53 | .is_ip = 1, /* This is for sending IP and ARP packages */ |
54 | .rx = rx, |
55 | .build_header = build_header, |
56 | .prepare_tx = prepare_tx, |
57 | .continue_tx = continue_tx, |
58 | .ack_tx = NULL |
59 | }; |
60 | |
61 | static int __init arcnet_rfc1201_init(void) |
62 | { |
63 | pr_info("%s\n" , "RFC1201 \"standard\" (`a') encapsulation support loaded" ); |
64 | |
65 | arc_proto_map[ARC_P_IP] |
66 | = arc_proto_map[ARC_P_IPV6] |
67 | = arc_proto_map[ARC_P_ARP] |
68 | = arc_proto_map[ARC_P_RARP] |
69 | = arc_proto_map[ARC_P_IPX] |
70 | = arc_proto_map[ARC_P_NOVELL_EC] |
71 | = &rfc1201_proto; |
72 | |
73 | /* if someone else already owns the broadcast, we won't take it */ |
74 | if (arc_bcast_proto == arc_proto_default) |
75 | arc_bcast_proto = &rfc1201_proto; |
76 | |
77 | return 0; |
78 | } |
79 | |
80 | static void __exit arcnet_rfc1201_exit(void) |
81 | { |
82 | arcnet_unregister_proto(proto: &rfc1201_proto); |
83 | } |
84 | |
85 | module_init(arcnet_rfc1201_init); |
86 | module_exit(arcnet_rfc1201_exit); |
87 | |
88 | /* Determine a packet's protocol ID. |
89 | * |
90 | * With ARCnet we have to convert everything to Ethernet-style stuff. |
91 | */ |
92 | static __be16 type_trans(struct sk_buff *skb, struct net_device *dev) |
93 | { |
94 | struct archdr *pkt = (struct archdr *)skb->data; |
95 | struct arc_rfc1201 *soft = &pkt->soft.rfc1201; |
96 | int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE; |
97 | |
98 | /* Pull off the arcnet header. */ |
99 | skb_reset_mac_header(skb); |
100 | skb_pull(skb, len: hdr_size); |
101 | |
102 | if (pkt->hard.dest == 0) { |
103 | skb->pkt_type = PACKET_BROADCAST; |
104 | } else if (dev->flags & IFF_PROMISC) { |
105 | /* if we're not sending to ourselves :) */ |
106 | if (pkt->hard.dest != dev->dev_addr[0]) |
107 | skb->pkt_type = PACKET_OTHERHOST; |
108 | } |
109 | /* now return the protocol number */ |
110 | switch (soft->proto) { |
111 | case ARC_P_IP: |
112 | return htons(ETH_P_IP); |
113 | case ARC_P_IPV6: |
114 | return htons(ETH_P_IPV6); |
115 | case ARC_P_ARP: |
116 | return htons(ETH_P_ARP); |
117 | case ARC_P_RARP: |
118 | return htons(ETH_P_RARP); |
119 | |
120 | case ARC_P_IPX: |
121 | case ARC_P_NOVELL_EC: |
122 | return htons(ETH_P_802_3); |
123 | default: |
124 | dev->stats.rx_errors++; |
125 | dev->stats.rx_crc_errors++; |
126 | return 0; |
127 | } |
128 | |
129 | return htons(ETH_P_IP); |
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 | arc_printk(D_DURING, dev, "it's an RFC1201 packet (length=%d)\n" , |
144 | length); |
145 | |
146 | if (length >= MinTU) |
147 | ofs = 512 - length; |
148 | else |
149 | ofs = 256 - length; |
150 | |
151 | if (soft->split_flag == 0xFF) { /* Exception Packet */ |
152 | if (length >= 4 + RFC1201_HDR_SIZE) { |
153 | arc_printk(D_DURING, dev, "compensating for exception packet\n" ); |
154 | } else { |
155 | arc_printk(D_EXTRA, dev, "short RFC1201 exception packet from %02Xh" , |
156 | saddr); |
157 | return; |
158 | } |
159 | |
160 | /* skip over 4-byte junkola */ |
161 | length -= 4; |
162 | ofs += 4; |
163 | lp->hw.copy_from_card(dev, bufnum, 512 - length, |
164 | soft, sizeof(pkt->soft)); |
165 | } |
166 | if (!soft->split_flag) { /* not split */ |
167 | arc_printk(D_RX, dev, "incoming is not split (splitflag=%d)\n" , |
168 | soft->split_flag); |
169 | |
170 | if (in->skb) { /* already assembling one! */ |
171 | arc_printk(D_EXTRA, dev, "aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n" , |
172 | in->sequence, soft->split_flag, |
173 | soft->sequence); |
174 | lp->rfc1201.aborted_seq = soft->sequence; |
175 | dev_kfree_skb_irq(skb: in->skb); |
176 | dev->stats.rx_errors++; |
177 | dev->stats.rx_missed_errors++; |
178 | in->skb = NULL; |
179 | } |
180 | in->sequence = soft->sequence; |
181 | |
182 | skb = alloc_skb(size: length + ARC_HDR_SIZE, GFP_ATOMIC); |
183 | if (!skb) { |
184 | dev->stats.rx_dropped++; |
185 | return; |
186 | } |
187 | skb_put(skb, len: length + ARC_HDR_SIZE); |
188 | skb->dev = dev; |
189 | |
190 | pkt = (struct archdr *)skb->data; |
191 | soft = &pkt->soft.rfc1201; |
192 | |
193 | /* up to sizeof(pkt->soft) has already |
194 | * been copied from the card |
195 | */ |
196 | memcpy(pkt, pkthdr, sizeof(struct archdr)); |
197 | if (length > sizeof(pkt->soft)) |
198 | lp->hw.copy_from_card(dev, bufnum, |
199 | ofs + sizeof(pkt->soft), |
200 | pkt->soft.raw + sizeof(pkt->soft), |
201 | length - sizeof(pkt->soft)); |
202 | |
203 | /* ARP packets have problems when sent from some DOS systems: |
204 | * the source address is always 0! |
205 | * So we take the hardware source addr (which is impossible |
206 | * to fumble) and insert it ourselves. |
207 | */ |
208 | if (soft->proto == ARC_P_ARP) { |
209 | struct arphdr *arp = (struct arphdr *)soft->payload; |
210 | |
211 | /* make sure addresses are the right length */ |
212 | if (arp->ar_hln == 1 && arp->ar_pln == 4) { |
213 | uint8_t *cptr = (uint8_t *)arp + sizeof(struct arphdr); |
214 | |
215 | if (!*cptr) { /* is saddr = 00? */ |
216 | arc_printk(D_EXTRA, dev, |
217 | "ARP source address was 00h, set to %02Xh\n" , |
218 | saddr); |
219 | dev->stats.rx_crc_errors++; |
220 | *cptr = saddr; |
221 | } else { |
222 | arc_printk(D_DURING, dev, "ARP source address (%Xh) is fine.\n" , |
223 | *cptr); |
224 | } |
225 | } else { |
226 | arc_printk(D_NORMAL, dev, "funny-shaped ARP packet. (%Xh, %Xh)\n" , |
227 | arp->ar_hln, arp->ar_pln); |
228 | dev->stats.rx_errors++; |
229 | dev->stats.rx_crc_errors++; |
230 | } |
231 | } |
232 | if (BUGLVL(D_SKB)) |
233 | arcnet_dump_skb(dev, skb, desc: "rx" ); |
234 | |
235 | skb->protocol = type_trans(skb, dev); |
236 | netif_rx(skb); |
237 | } else { /* split packet */ |
238 | /* NOTE: MSDOS ARP packet correction should only need to |
239 | * apply to unsplit packets, since ARP packets are so short. |
240 | * |
241 | * My interpretation of the RFC1201 document is that if a |
242 | * packet is received out of order, the entire assembly |
243 | * process should be aborted. |
244 | * |
245 | * The RFC also mentions "it is possible for successfully |
246 | * received packets to be retransmitted." As of 0.40 all |
247 | * previously received packets are allowed, not just the |
248 | * most recent one. |
249 | * |
250 | * We allow multiple assembly processes, one for each |
251 | * ARCnet card possible on the network. |
252 | * Seems rather like a waste of memory, but there's no |
253 | * other way to be reliable. |
254 | */ |
255 | |
256 | arc_printk(D_RX, dev, "packet is split (splitflag=%d, seq=%d)\n" , |
257 | soft->split_flag, in->sequence); |
258 | |
259 | if (in->skb && in->sequence != soft->sequence) { |
260 | arc_printk(D_EXTRA, dev, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n" , |
261 | saddr, in->sequence, soft->sequence, |
262 | soft->split_flag); |
263 | dev_kfree_skb_irq(skb: in->skb); |
264 | in->skb = NULL; |
265 | dev->stats.rx_errors++; |
266 | dev->stats.rx_missed_errors++; |
267 | in->lastpacket = in->numpackets = 0; |
268 | } |
269 | if (soft->split_flag & 1) { /* first packet in split */ |
270 | arc_printk(D_RX, dev, "brand new splitpacket (splitflag=%d)\n" , |
271 | soft->split_flag); |
272 | if (in->skb) { /* already assembling one! */ |
273 | arc_printk(D_EXTRA, dev, "aborting previous (seq=%d) assembly (splitflag=%d, seq=%d)\n" , |
274 | in->sequence, soft->split_flag, |
275 | soft->sequence); |
276 | dev->stats.rx_errors++; |
277 | dev->stats.rx_missed_errors++; |
278 | dev_kfree_skb_irq(skb: in->skb); |
279 | } |
280 | in->sequence = soft->sequence; |
281 | in->numpackets = ((unsigned)soft->split_flag >> 1) + 2; |
282 | in->lastpacket = 1; |
283 | |
284 | if (in->numpackets > 16) { |
285 | arc_printk(D_EXTRA, dev, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n" , |
286 | soft->split_flag); |
287 | lp->rfc1201.aborted_seq = soft->sequence; |
288 | dev->stats.rx_errors++; |
289 | dev->stats.rx_length_errors++; |
290 | return; |
291 | } |
292 | in->skb = skb = alloc_skb(size: 508 * in->numpackets + ARC_HDR_SIZE, |
293 | GFP_ATOMIC); |
294 | if (!skb) { |
295 | arc_printk(D_NORMAL, dev, "(split) memory squeeze, dropping packet.\n" ); |
296 | lp->rfc1201.aborted_seq = soft->sequence; |
297 | dev->stats.rx_dropped++; |
298 | return; |
299 | } |
300 | skb->dev = dev; |
301 | pkt = (struct archdr *)skb->data; |
302 | soft = &pkt->soft.rfc1201; |
303 | |
304 | memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE); |
305 | skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE); |
306 | |
307 | soft->split_flag = 0; /* end result won't be split */ |
308 | } else { /* not first packet */ |
309 | int packetnum = ((unsigned)soft->split_flag >> 1) + 1; |
310 | |
311 | /* if we're not assembling, there's no point trying to |
312 | * continue. |
313 | */ |
314 | if (!in->skb) { |
315 | if (lp->rfc1201.aborted_seq != soft->sequence) { |
316 | arc_printk(D_EXTRA, dev, "can't continue split without starting first! (splitflag=%d, seq=%d, aborted=%d)\n" , |
317 | soft->split_flag, |
318 | soft->sequence, |
319 | lp->rfc1201.aborted_seq); |
320 | dev->stats.rx_errors++; |
321 | dev->stats.rx_missed_errors++; |
322 | } |
323 | return; |
324 | } |
325 | in->lastpacket++; |
326 | /* if not the right flag */ |
327 | if (packetnum != in->lastpacket) { |
328 | /* harmless duplicate? ignore. */ |
329 | if (packetnum <= in->lastpacket - 1) { |
330 | arc_printk(D_EXTRA, dev, "duplicate splitpacket ignored! (splitflag=%d)\n" , |
331 | soft->split_flag); |
332 | dev->stats.rx_errors++; |
333 | dev->stats.rx_frame_errors++; |
334 | return; |
335 | } |
336 | /* "bad" duplicate, kill reassembly */ |
337 | arc_printk(D_EXTRA, dev, "out-of-order splitpacket, reassembly (seq=%d) aborted (splitflag=%d, seq=%d)\n" , |
338 | in->sequence, soft->split_flag, |
339 | soft->sequence); |
340 | lp->rfc1201.aborted_seq = soft->sequence; |
341 | dev_kfree_skb_irq(skb: in->skb); |
342 | in->skb = NULL; |
343 | dev->stats.rx_errors++; |
344 | dev->stats.rx_missed_errors++; |
345 | in->lastpacket = in->numpackets = 0; |
346 | return; |
347 | } |
348 | pkt = (struct archdr *)in->skb->data; |
349 | soft = &pkt->soft.rfc1201; |
350 | } |
351 | |
352 | skb = in->skb; |
353 | |
354 | lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE, |
355 | skb->data + skb->len, |
356 | length - RFC1201_HDR_SIZE); |
357 | skb_put(skb, len: length - RFC1201_HDR_SIZE); |
358 | |
359 | /* are we done? */ |
360 | if (in->lastpacket == in->numpackets) { |
361 | in->skb = NULL; |
362 | in->lastpacket = in->numpackets = 0; |
363 | |
364 | arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (unsplit)\n" , |
365 | skb->len, pkt->hard.source); |
366 | arc_printk(D_SKB_SIZE, dev, "skb: received %d bytes from %02X (split)\n" , |
367 | skb->len, pkt->hard.source); |
368 | if (BUGLVL(D_SKB)) |
369 | arcnet_dump_skb(dev, skb, desc: "rx" ); |
370 | |
371 | skb->protocol = type_trans(skb, dev); |
372 | netif_rx(skb); |
373 | } |
374 | } |
375 | } |
376 | |
377 | /* Create the ARCnet hard/soft headers for RFC1201. */ |
378 | static int (struct sk_buff *skb, struct net_device *dev, |
379 | unsigned short type, uint8_t daddr) |
380 | { |
381 | struct arcnet_local *lp = netdev_priv(dev); |
382 | int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE; |
383 | struct archdr *pkt = skb_push(skb, len: hdr_size); |
384 | struct arc_rfc1201 *soft = &pkt->soft.rfc1201; |
385 | |
386 | /* set the protocol ID according to RFC1201 */ |
387 | switch (type) { |
388 | case ETH_P_IP: |
389 | soft->proto = ARC_P_IP; |
390 | break; |
391 | case ETH_P_IPV6: |
392 | soft->proto = ARC_P_IPV6; |
393 | break; |
394 | case ETH_P_ARP: |
395 | soft->proto = ARC_P_ARP; |
396 | break; |
397 | case ETH_P_RARP: |
398 | soft->proto = ARC_P_RARP; |
399 | break; |
400 | case ETH_P_IPX: |
401 | case ETH_P_802_3: |
402 | case ETH_P_802_2: |
403 | soft->proto = ARC_P_IPX; |
404 | break; |
405 | case ETH_P_ATALK: |
406 | soft->proto = ARC_P_ATALK; |
407 | break; |
408 | default: |
409 | arc_printk(D_NORMAL, dev, "RFC1201: I don't understand protocol %d (%Xh)\n" , |
410 | type, type); |
411 | dev->stats.tx_errors++; |
412 | dev->stats.tx_aborted_errors++; |
413 | return 0; |
414 | } |
415 | |
416 | /* Set the source hardware address. |
417 | * |
418 | * This is pretty pointless for most purposes, but it can help in |
419 | * debugging. ARCnet does not allow us to change the source address |
420 | * in the actual packet sent. |
421 | */ |
422 | pkt->hard.source = *dev->dev_addr; |
423 | |
424 | soft->sequence = htons(lp->rfc1201.sequence++); |
425 | soft->split_flag = 0; /* split packets are done elsewhere */ |
426 | |
427 | /* see linux/net/ethernet/eth.c to see where I got the following */ |
428 | |
429 | if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) { |
430 | /* FIXME: fill in the last byte of the dest ipaddr here |
431 | * to better comply with RFC1051 in "noarp" mode. |
432 | * For now, always broadcasting will probably at least get |
433 | * packets sent out :) |
434 | */ |
435 | pkt->hard.dest = 0; |
436 | return hdr_size; |
437 | } |
438 | /* otherwise, drop in the dest address */ |
439 | pkt->hard.dest = daddr; |
440 | return hdr_size; |
441 | } |
442 | |
443 | static void load_pkt(struct net_device *dev, struct arc_hardware *hard, |
444 | struct arc_rfc1201 *soft, int softlen, int bufnum) |
445 | { |
446 | struct arcnet_local *lp = netdev_priv(dev); |
447 | int ofs; |
448 | |
449 | /* assume length <= XMTU: someone should have handled that by now. */ |
450 | |
451 | if (softlen > MinTU) { |
452 | hard->offset[0] = 0; |
453 | hard->offset[1] = ofs = 512 - softlen; |
454 | } else if (softlen > MTU) { /* exception packet - add an extra header */ |
455 | struct arc_rfc1201 excsoft; |
456 | |
457 | excsoft.proto = soft->proto; |
458 | excsoft.split_flag = 0xff; |
459 | excsoft.sequence = htons(0xffff); |
460 | |
461 | hard->offset[0] = 0; |
462 | ofs = 512 - softlen; |
463 | hard->offset[1] = ofs - RFC1201_HDR_SIZE; |
464 | lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE, |
465 | &excsoft, RFC1201_HDR_SIZE); |
466 | } else { |
467 | hard->offset[0] = ofs = 256 - softlen; |
468 | } |
469 | |
470 | lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE); |
471 | lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen); |
472 | |
473 | lp->lastload_dest = hard->dest; |
474 | } |
475 | |
476 | static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, |
477 | int bufnum) |
478 | { |
479 | struct arcnet_local *lp = netdev_priv(dev); |
480 | const int maxsegsize = XMTU - RFC1201_HDR_SIZE; |
481 | struct Outgoing *out; |
482 | |
483 | arc_printk(D_DURING, dev, "prepare_tx: txbufs=%d/%d/%d\n" , |
484 | lp->next_tx, lp->cur_tx, bufnum); |
485 | |
486 | /* hard header is not included in packet length */ |
487 | length -= ARC_HDR_SIZE; |
488 | pkt->soft.rfc1201.split_flag = 0; |
489 | |
490 | /* need to do a split packet? */ |
491 | if (length > XMTU) { |
492 | out = &lp->outgoing; |
493 | |
494 | out->length = length - RFC1201_HDR_SIZE; |
495 | out->dataleft = lp->outgoing.length; |
496 | out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize; |
497 | out->segnum = 0; |
498 | |
499 | arc_printk(D_DURING, dev, "rfc1201 prep_tx: ready for %d-segment split (%d bytes, seq=%d)\n" , |
500 | out->numsegs, out->length, |
501 | pkt->soft.rfc1201.sequence); |
502 | |
503 | return 0; /* not done */ |
504 | } |
505 | /* just load the packet into the buffers and send it off */ |
506 | load_pkt(dev, hard: &pkt->hard, soft: &pkt->soft.rfc1201, softlen: length, bufnum); |
507 | |
508 | return 1; /* done */ |
509 | } |
510 | |
511 | static int continue_tx(struct net_device *dev, int bufnum) |
512 | { |
513 | struct arcnet_local *lp = netdev_priv(dev); |
514 | struct Outgoing *out = &lp->outgoing; |
515 | struct arc_hardware *hard = &out->pkt->hard; |
516 | struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft; |
517 | int maxsegsize = XMTU - RFC1201_HDR_SIZE; |
518 | int seglen; |
519 | |
520 | arc_printk(D_DURING, dev, |
521 | "rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n" , |
522 | out->segnum, out->numsegs, soft->sequence); |
523 | |
524 | /* the "new" soft header comes right before the data chunk */ |
525 | newsoft = (struct arc_rfc1201 *) |
526 | (out->pkt->soft.raw + out->length - out->dataleft); |
527 | |
528 | if (!out->segnum) /* first packet; newsoft == soft */ |
529 | newsoft->split_flag = ((out->numsegs - 2) << 1) | 1; |
530 | else { |
531 | newsoft->split_flag = out->segnum << 1; |
532 | newsoft->proto = soft->proto; |
533 | newsoft->sequence = soft->sequence; |
534 | } |
535 | |
536 | seglen = maxsegsize; |
537 | if (seglen > out->dataleft) |
538 | seglen = out->dataleft; |
539 | out->dataleft -= seglen; |
540 | |
541 | load_pkt(dev, hard, soft: newsoft, softlen: seglen + RFC1201_HDR_SIZE, bufnum); |
542 | |
543 | out->segnum++; |
544 | if (out->segnum >= out->numsegs) |
545 | return 1; |
546 | else |
547 | return 0; |
548 | } |
549 | |