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 33MODULE_LICENSE("GPL"); 34#define VERSION "arcnet: RFC1201 \"standard\" (`a') encapsulation support loaded.\n" 35 36 37static unsigned short type_trans(struct sk_buff *skb, struct net_device *dev); 38static void rx(struct net_device *dev, int bufnum, 39 struct archdr *pkthdr, int length); 40static int build_header(struct sk_buff *skb, struct net_device *dev, 41 unsigned short type, uint8_t daddr); 42static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, 43 int bufnum); 44static int continue_tx(struct net_device *dev, int bufnum); 45 46static 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 59static 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 78static void __exit arcnet_rfc1201_exit(void) 79{ 80 arcnet_unregister_proto(&rfc1201_proto); 81} 82 83module_init(arcnet_rfc1201_init); 84module_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 */ 91static unsigned short 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 struct arcnet_local *lp = dev->priv; 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, 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 lp->stats.rx_errors++; 125 lp->stats.rx_crc_errors++; 126 return 0; 127 } 128 129 return htons(ETH_P_IP); 130} 131 132 133/* packet receiver */ 134static void rx(struct net_device *dev, int bufnum, 135 struct archdr *pkthdr, int length) 136{ 137 struct arcnet_local *lp = dev->priv; 138 struct sk_buff *skb; 139 struct archdr *pkt = pkthdr; 140 struct arc_rfc1201 *soft = &pkthdr->soft.rfc1201; 141 int saddr = pkt->hard.source, ofs; 142 struct Incoming *in = &lp->rfc1201.incoming[saddr]; 143 144 BUGMSG(D_DURING, "it's an RFC1201 packet (length=%d)\n", 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 BUGMSG(D_DURING, "compensating for exception packet\n"); 154 else { 155 BUGMSG(D_EXTRA, "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 BUGMSG(D_RX, "incoming is not split (splitflag=%d)\n", 168 soft->split_flag); 169 170 if (in->skb) { /* already assembling one! */ 171 BUGMSG(D_EXTRA, "aborting assembly (seq=%d) for unsplit packet (splitflag=%d, seq=%d)\n", 172 in->sequence, soft->split_flag, soft->sequence); 173 lp->rfc1201.aborted_seq = soft->sequence; 174 dev_kfree_skb_irq(in->skb); 175 lp->stats.rx_errors++; 176 lp->stats.rx_missed_errors++; 177 in->skb = NULL; 178 } 179 in->sequence = soft->sequence; 180 181 skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC); 182 if (skb == NULL) { 183 BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n"); 184 lp->stats.rx_dropped++; 185 return; 186 } 187 skb_put(skb, 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 been copied from the card */ 194 memcpy(pkt, pkthdr, sizeof(struct archdr)); 195 if (length > sizeof(pkt->soft)) 196 lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft), 197 pkt->soft.raw + sizeof(pkt->soft), 198 length - sizeof(pkt->soft)); 199 200 /* 201 * ARP packets have problems when sent from some DOS systems: the 202 * source address is always 0! So we take the hardware source addr 203 * (which is impossible to fumble) and insert it ourselves. 204 */ 205 if (soft->proto == ARC_P_ARP) { 206 struct arphdr *arp = (struct arphdr *) soft->payload; 207 208 /* make sure addresses are the right length */ 209 if (arp->ar_hln == 1 && arp->ar_pln == 4) { 210 uint8_t *cptr = (uint8_t *) arp + sizeof(struct arphdr); 211 212 if (!*cptr) { /* is saddr = 00? */ 213 BUGMSG(D_EXTRA, 214 "ARP source address was 00h, set to %02Xh.\n", 215 saddr); 216 lp->stats.rx_crc_errors++; 217 *cptr = saddr; 218 } else { 219 BUGMSG(D_DURING, "ARP source address (%Xh) is fine.\n", 220 *cptr); 221 } 222 } else { 223 BUGMSG(D_NORMAL, "funny-shaped ARP packet. (%Xh, %Xh)\n", 224 arp->ar_hln, arp->ar_pln); 225 lp->stats.rx_errors++; 226 lp->stats.rx_crc_errors++; 227 } 228 } 229 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx"); 230 231 skb->protocol = type_trans(skb, dev); 232 netif_rx(skb); 233 dev->last_rx = jiffies; 234 } else { /* split packet */ 235 /* 236 * NOTE: MSDOS ARP packet correction should only need to apply to 237 * unsplit packets, since ARP packets are so short. 238 * 239 * My interpretation of the RFC1201 document is that if a packet is 240 * received out of order, the entire assembly process should be 241 * aborted. 242 * 243 * The RFC also mentions "it is possible for successfully received 244 * packets to be retransmitted." As of 0.40 all previously received 245 * packets are allowed, not just the most recent one. 246 * 247 * We allow multiple assembly processes, one for each ARCnet card 248 * possible on the network. Seems rather like a waste of memory, 249 * but there's no other way to be reliable. 250 */ 251 252 BUGMSG(D_RX, "packet is split (splitflag=%d, seq=%d)\n", 253 soft->split_flag, in->sequence); 254 255 if (in->skb && in->sequence != soft->sequence) { 256 BUGMSG(D_EXTRA, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n", 257 saddr, in->sequence, soft->sequence, 258 soft->split_flag); 259 dev_kfree_skb_irq(in->skb); 260 in->skb = NULL; 261 lp->stats.rx_errors++; 262 lp->stats.rx_missed_errors++; 263 in->lastpacket = in->numpackets = 0; 264 } 265 if (soft->split_flag & 1) { /* first packet in split */ 266 BUGMSG(D_RX, "brand new splitpacket (splitflag=%d)\n", 267 soft->split_flag); 268 if (in->skb) { /* already assembling one! */ 269 BUGMSG(D_EXTRA, "aborting previous (seq=%d) assembly " 270 "(splitflag=%d, seq=%d)\n", 271 in->sequence, soft->split_flag, 272 soft->sequence); 273 lp->stats.rx_errors++; 274 lp->stats.rx_missed_errors++; 275 dev_kfree_skb_irq(in->skb); 276 } 277 in->sequence = soft->sequence; 278 in->numpackets = ((unsigned) soft->split_flag >> 1) + 2; 279 in->lastpacket = 1; 280 281 if (in->numpackets > 16) { 282 BUGMSG(D_EXTRA, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n", 283 soft->split_flag); 284 lp->rfc1201.aborted_seq = soft->sequence; 285 lp->stats.rx_errors++; 286 lp->stats.rx_length_errors++; 287 return; 288 } 289 in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE, 290 GFP_ATOMIC); 291 if (skb == NULL) { 292 BUGMSG(D_NORMAL, "(split) memory squeeze, dropping packet.\n"); 293 lp->rfc1201.aborted_seq = soft->sequence; 294 lp->stats.rx_dropped++; 295 return; 296 } 297 skb->dev = dev; 298 pkt = (struct archdr *) skb->data; 299 soft = &pkt->soft.rfc1201; 300 301 memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE); 302 skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE); 303 304 soft->split_flag = 0; /* end result won't be split */ 305 } else { /* not first packet */ 306 int packetnum = ((unsigned) soft->split_flag >> 1) + 1; 307 308 /* 309 * if we're not assembling, there's no point trying to 310 * continue. 311 */ 312 if (!in->skb) { 313 if (lp->rfc1201.aborted_seq != soft->sequence) { 314 BUGMSG(D_EXTRA, "can't continue split without starting " 315 "first! (splitflag=%d, seq=%d, aborted=%d)\n", 316 soft->split_flag, soft->sequence, 317 lp->rfc1201.aborted_seq); 318 lp->stats.rx_errors++; 319 lp->stats.rx_missed_errors++; 320 } 321 return; 322 } 323 in->lastpacket++; 324 if (packetnum != in->lastpacket) { /* not the right flag! */ 325 /* harmless duplicate? ignore. */ 326 if (packetnum <= in->lastpacket - 1) { 327 BUGMSG(D_EXTRA, "duplicate splitpacket ignored! (splitflag=%d)\n", 328 soft->split_flag); 329 lp->stats.rx_errors++; 330 lp->stats.rx_frame_errors++; 331 return; 332 } 333 /* "bad" duplicate, kill reassembly */ 334 BUGMSG(D_EXTRA, "out-of-order splitpacket, reassembly " 335 "(seq=%d) aborted (splitflag=%d, seq=%d)\n", 336 in->sequence, soft->split_flag, soft->sequence); 337 lp->rfc1201.aborted_seq = soft->sequence; 338 dev_kfree_skb_irq(in->skb); 339 in->skb = NULL; 340 lp->stats.rx_errors++; 341 lp->stats.rx_missed_errors++; 342 in->lastpacket = in->numpackets = 0; 343 return; 344 } 345 pkt = (struct archdr *) in->skb->data; 346 soft = &pkt->soft.rfc1201; 347 } 348 349 skb = in->skb; 350 351 lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE, 352 skb->data + skb->len, 353 length - RFC1201_HDR_SIZE); 354 skb_put(skb, length - RFC1201_HDR_SIZE); 355 356 /* are we done? */ 357 if (in->lastpacket == in->numpackets) { 358 in->skb = NULL; 359 in->lastpacket = in->numpackets = 0; 360 361 BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (unsplit)\n", 362 skb->len, pkt->hard.source); 363 BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (split)\n", 364 skb->len, pkt->hard.source); 365 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx"); 366 367 skb->protocol = type_trans(skb, dev); 368 netif_rx(skb); 369 dev->last_rx = jiffies; 370 } 371 } 372} 373 374 375/* Create the ARCnet hard/soft headers for RFC1201. */ 376static int build_header(struct sk_buff *skb, struct net_device *dev, 377 unsigned short type, uint8_t daddr) 378{ 379 struct arcnet_local *lp = dev->priv; 380 int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE; 381 struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size); 382 struct arc_rfc1201 *soft = &pkt->soft.rfc1201; 383 384 /* set the protocol ID according to RFC1201 */ 385 switch (type) { 386 case ETH_P_IP: 387 soft->proto = ARC_P_IP; 388 break; 389 case ETH_P_IPV6: 390 soft->proto = ARC_P_IPV6; 391 break; 392 case ETH_P_ARP: 393 soft->proto = ARC_P_ARP; 394 break; 395 case ETH_P_RARP: 396 soft->proto = ARC_P_RARP; 397 break; 398 case ETH_P_IPX: 399 case ETH_P_802_3: 400 case ETH_P_802_2: 401 soft->proto = ARC_P_IPX; 402 break; 403 case ETH_P_ATALK: 404 soft->proto = ARC_P_ATALK; 405 break; 406 default: 407 BUGMSG(D_NORMAL, "RFC1201: I don't understand protocol %d (%Xh)\n", 408 type, type); 409 lp->stats.tx_errors++; 410 lp->stats.tx_aborted_errors++; 411 return 0; 412 } 413 414 /* 415 * Set the source hardware address. 416 * 417 * This is pretty pointless for most purposes, but it can help in 418 * debugging. ARCnet does not allow us to change the source address in 419 * the actual packet sent) 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)) { 429 pkt->hard.dest = 0; 430 return hdr_size; 431 } 432 /* otherwise, drop in the dest address */ 433 pkt->hard.dest = daddr; 434 return hdr_size; 435} 436 437 438static void load_pkt(struct net_device *dev, struct arc_hardware *hard, 439 struct arc_rfc1201 *soft, int softlen, int bufnum) 440{ 441 struct arcnet_local *lp = dev->priv; 442 int ofs; 443 444 /* assume length <= XMTU: someone should have handled that by now. */ 445 446 if (softlen > MinTU) { 447 hard->offset[0] = 0; 448 hard->offset[1] = ofs = 512 - softlen; 449 } else if (softlen > MTU) { /* exception packet - add an extra header */ 450 struct arc_rfc1201 excsoft; 451 452 excsoft.proto = soft->proto; 453 excsoft.split_flag = 0xff; 454 excsoft.sequence = 0xffff; 455 456 hard->offset[0] = 0; 457 ofs = 512 - softlen; 458 hard->offset[1] = ofs - RFC1201_HDR_SIZE; 459 lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE, 460 &excsoft, RFC1201_HDR_SIZE); 461 } else 462 hard->offset[0] = ofs = 256 - softlen; 463 464 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE); 465 lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen); 466 467 lp->lastload_dest = hard->dest; 468} 469 470 471static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, 472 int bufnum) 473{ 474 struct arcnet_local *lp = dev->priv; 475 const int maxsegsize = XMTU - RFC1201_HDR_SIZE; 476 struct Outgoing *out; 477 478 479 BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n", 480 lp->next_tx, lp->cur_tx, bufnum); 481 482 length -= ARC_HDR_SIZE; /* hard header is not included in packet length */ 483 pkt->soft.rfc1201.split_flag = 0; 484 485 /* need to do a split packet? */ 486 if (length > XMTU) { 487 out = &lp->outgoing; 488 489 out->length = length - RFC1201_HDR_SIZE; 490 out->dataleft = lp->outgoing.length; 491 out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize; 492 out->segnum = 0; 493 494 BUGMSG(D_DURING, "rfc1201 prep_tx: ready for %d-segment split " 495 "(%d bytes, seq=%d)\n", out->numsegs, out->length, 496 pkt->soft.rfc1201.sequence); 497 498 return 0; /* not done */ 499 } 500 /* just load the packet into the buffers and send it off */ 501 load_pkt(dev, &pkt->hard, &pkt->soft.rfc1201, length, bufnum); 502 503 return 1; /* done */ 504} 505 506 507static int continue_tx(struct net_device *dev, int bufnum) 508{ 509 struct arcnet_local *lp = dev->priv; 510 struct Outgoing *out = &lp->outgoing; 511 struct arc_hardware *hard = &out->pkt->hard; 512 struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft; 513 int maxsegsize = XMTU - RFC1201_HDR_SIZE; 514 int seglen; 515 516 BUGMSG(D_DURING, 517 "rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n", 518 out->segnum, out->numsegs, soft->sequence); 519 520 /* the "new" soft header comes right before the data chunk */ 521 newsoft = (struct arc_rfc1201 *) 522 (out->pkt->soft.raw + out->length - out->dataleft); 523 524 if (!out->segnum) /* first packet; newsoft == soft */ 525 newsoft->split_flag = ((out->numsegs - 2) << 1) | 1; 526 else { 527 newsoft->split_flag = out->segnum << 1; 528 newsoft->proto = soft->proto; 529 newsoft->sequence = soft->sequence; 530 } 531 532 seglen = maxsegsize; 533 if (seglen > out->dataleft) 534 seglen = out->dataleft; 535 out->dataleft -= seglen; 536 537 load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum); 538 539 out->segnum++; 540 if (out->segnum >= out->numsegs) 541 return 1; 542 else 543 return 0; 544} 545