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 38 static __be16 type_trans(struct sk_buff *skb, struct net_device *dev); 39 static void rx(struct net_device *dev, int bufnum, 40 struct archdr *pkthdr, int length); 41 static int build_header(struct sk_buff *skb, struct net_device *dev, 42 unsigned short type, uint8_t daddr); 43 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, 44 int bufnum); 45 static int continue_tx(struct net_device *dev, int bufnum); 46 47 static struct ArcProto rfc1201_proto = 48 { 49 .suffix = 'a', 50 .mtu = 1500, /* could be more, but some receivers can't handle it... */ 51 .is_ip = 1, /* This is for sending IP and ARP packages */ 52 .rx = rx, 53 .build_header = build_header, 54 .prepare_tx = prepare_tx, 55 .continue_tx = continue_tx, 56 .ack_tx = NULL 57 }; 58 59 60 static int __init arcnet_rfc1201_init(void) 61 { 62 printk(VERSION); 63 64 arc_proto_map[ARC_P_IP] 65 = arc_proto_map[ARC_P_IPV6] 66 = arc_proto_map[ARC_P_ARP] 67 = arc_proto_map[ARC_P_RARP] 68 = arc_proto_map[ARC_P_IPX] 69 = arc_proto_map[ARC_P_NOVELL_EC] 70 = &rfc1201_proto; 71 72 /* if someone else already owns the broadcast, we won't take it */ 73 if (arc_bcast_proto == arc_proto_default) 74 arc_bcast_proto = &rfc1201_proto; 75 76 return 0; 77 } 78 79 static void __exit arcnet_rfc1201_exit(void) 80 { 81 arcnet_unregister_proto(&rfc1201_proto); 82 } 83 84 module_init(arcnet_rfc1201_init); 85 module_exit(arcnet_rfc1201_exit); 86 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, 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 } 131 132 133 /* packet receiver */ 134 static void rx(struct net_device *dev, int bufnum, 135 struct archdr *pkthdr, int length) 136 { 137 struct arcnet_local *lp = netdev_priv(dev); 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 dev->stats.rx_errors++; 176 dev->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 dev->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 dev->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 dev->stats.rx_errors++; 226 dev->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 } else { /* split packet */ 234 /* 235 * NOTE: MSDOS ARP packet correction should only need to apply to 236 * unsplit packets, since ARP packets are so short. 237 * 238 * My interpretation of the RFC1201 document is that if a packet is 239 * received out of order, the entire assembly process should be 240 * aborted. 241 * 242 * The RFC also mentions "it is possible for successfully received 243 * packets to be retransmitted." As of 0.40 all previously received 244 * packets are allowed, not just the most recent one. 245 * 246 * We allow multiple assembly processes, one for each ARCnet card 247 * possible on the network. Seems rather like a waste of memory, 248 * but there's no other way to be reliable. 249 */ 250 251 BUGMSG(D_RX, "packet is split (splitflag=%d, seq=%d)\n", 252 soft->split_flag, in->sequence); 253 254 if (in->skb && in->sequence != soft->sequence) { 255 BUGMSG(D_EXTRA, "wrong seq number (saddr=%d, expected=%d, seq=%d, splitflag=%d)\n", 256 saddr, in->sequence, soft->sequence, 257 soft->split_flag); 258 dev_kfree_skb_irq(in->skb); 259 in->skb = NULL; 260 dev->stats.rx_errors++; 261 dev->stats.rx_missed_errors++; 262 in->lastpacket = in->numpackets = 0; 263 } 264 if (soft->split_flag & 1) { /* first packet in split */ 265 BUGMSG(D_RX, "brand new splitpacket (splitflag=%d)\n", 266 soft->split_flag); 267 if (in->skb) { /* already assembling one! */ 268 BUGMSG(D_EXTRA, "aborting previous (seq=%d) assembly " 269 "(splitflag=%d, seq=%d)\n", 270 in->sequence, soft->split_flag, 271 soft->sequence); 272 dev->stats.rx_errors++; 273 dev->stats.rx_missed_errors++; 274 dev_kfree_skb_irq(in->skb); 275 } 276 in->sequence = soft->sequence; 277 in->numpackets = ((unsigned) soft->split_flag >> 1) + 2; 278 in->lastpacket = 1; 279 280 if (in->numpackets > 16) { 281 BUGMSG(D_EXTRA, "incoming packet more than 16 segments; dropping. (splitflag=%d)\n", 282 soft->split_flag); 283 lp->rfc1201.aborted_seq = soft->sequence; 284 dev->stats.rx_errors++; 285 dev->stats.rx_length_errors++; 286 return; 287 } 288 in->skb = skb = alloc_skb(508 * in->numpackets + ARC_HDR_SIZE, 289 GFP_ATOMIC); 290 if (skb == NULL) { 291 BUGMSG(D_NORMAL, "(split) memory squeeze, dropping packet.\n"); 292 lp->rfc1201.aborted_seq = soft->sequence; 293 dev->stats.rx_dropped++; 294 return; 295 } 296 skb->dev = dev; 297 pkt = (struct archdr *) skb->data; 298 soft = &pkt->soft.rfc1201; 299 300 memcpy(pkt, pkthdr, ARC_HDR_SIZE + RFC1201_HDR_SIZE); 301 skb_put(skb, ARC_HDR_SIZE + RFC1201_HDR_SIZE); 302 303 soft->split_flag = 0; /* end result won't be split */ 304 } else { /* not first packet */ 305 int packetnum = ((unsigned) soft->split_flag >> 1) + 1; 306 307 /* 308 * if we're not assembling, there's no point trying to 309 * continue. 310 */ 311 if (!in->skb) { 312 if (lp->rfc1201.aborted_seq != soft->sequence) { 313 BUGMSG(D_EXTRA, "can't continue split without starting " 314 "first! (splitflag=%d, seq=%d, aborted=%d)\n", 315 soft->split_flag, soft->sequence, 316 lp->rfc1201.aborted_seq); 317 dev->stats.rx_errors++; 318 dev->stats.rx_missed_errors++; 319 } 320 return; 321 } 322 in->lastpacket++; 323 if (packetnum != in->lastpacket) { /* not the right flag! */ 324 /* harmless duplicate? ignore. */ 325 if (packetnum <= in->lastpacket - 1) { 326 BUGMSG(D_EXTRA, "duplicate splitpacket ignored! (splitflag=%d)\n", 327 soft->split_flag); 328 dev->stats.rx_errors++; 329 dev->stats.rx_frame_errors++; 330 return; 331 } 332 /* "bad" duplicate, kill reassembly */ 333 BUGMSG(D_EXTRA, "out-of-order splitpacket, reassembly " 334 "(seq=%d) aborted (splitflag=%d, seq=%d)\n", 335 in->sequence, soft->split_flag, soft->sequence); 336 lp->rfc1201.aborted_seq = soft->sequence; 337 dev_kfree_skb_irq(in->skb); 338 in->skb = NULL; 339 dev->stats.rx_errors++; 340 dev->stats.rx_missed_errors++; 341 in->lastpacket = in->numpackets = 0; 342 return; 343 } 344 pkt = (struct archdr *) in->skb->data; 345 soft = &pkt->soft.rfc1201; 346 } 347 348 skb = in->skb; 349 350 lp->hw.copy_from_card(dev, bufnum, ofs + RFC1201_HDR_SIZE, 351 skb->data + skb->len, 352 length - RFC1201_HDR_SIZE); 353 skb_put(skb, length - RFC1201_HDR_SIZE); 354 355 /* are we done? */ 356 if (in->lastpacket == in->numpackets) { 357 in->skb = NULL; 358 in->lastpacket = in->numpackets = 0; 359 360 BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (unsplit)\n", 361 skb->len, pkt->hard.source); 362 BUGMSG(D_SKB_SIZE, "skb: received %d bytes from %02X (split)\n", 363 skb->len, pkt->hard.source); 364 BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx"); 365 366 skb->protocol = type_trans(skb, dev); 367 netif_rx(skb); 368 } 369 } 370 } 371 372 373 /* Create the ARCnet hard/soft headers for RFC1201. */ 374 static int build_header(struct sk_buff *skb, struct net_device *dev, 375 unsigned short type, uint8_t daddr) 376 { 377 struct arcnet_local *lp = netdev_priv(dev); 378 int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE; 379 struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size); 380 struct arc_rfc1201 *soft = &pkt->soft.rfc1201; 381 382 /* set the protocol ID according to RFC1201 */ 383 switch (type) { 384 case ETH_P_IP: 385 soft->proto = ARC_P_IP; 386 break; 387 case ETH_P_IPV6: 388 soft->proto = ARC_P_IPV6; 389 break; 390 case ETH_P_ARP: 391 soft->proto = ARC_P_ARP; 392 break; 393 case ETH_P_RARP: 394 soft->proto = ARC_P_RARP; 395 break; 396 case ETH_P_IPX: 397 case ETH_P_802_3: 398 case ETH_P_802_2: 399 soft->proto = ARC_P_IPX; 400 break; 401 case ETH_P_ATALK: 402 soft->proto = ARC_P_ATALK; 403 break; 404 default: 405 BUGMSG(D_NORMAL, "RFC1201: I don't understand protocol %d (%Xh)\n", 406 type, type); 407 dev->stats.tx_errors++; 408 dev->stats.tx_aborted_errors++; 409 return 0; 410 } 411 412 /* 413 * Set the source hardware address. 414 * 415 * This is pretty pointless for most purposes, but it can help in 416 * debugging. ARCnet does not allow us to change the source address in 417 * the actual packet sent) 418 */ 419 pkt->hard.source = *dev->dev_addr; 420 421 soft->sequence = htons(lp->rfc1201.sequence++); 422 soft->split_flag = 0; /* split packets are done elsewhere */ 423 424 /* see linux/net/ethernet/eth.c to see where I got the following */ 425 426 if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) { 427 /* 428 * FIXME: fill in the last byte of the dest ipaddr here to better 429 * comply with RFC1051 in "noarp" mode. For now, always broadcasting 430 * will probably at least get packets sent out :) 431 */ 432 pkt->hard.dest = 0; 433 return hdr_size; 434 } 435 /* otherwise, drop in the dest address */ 436 pkt->hard.dest = daddr; 437 return hdr_size; 438 } 439 440 441 static void load_pkt(struct net_device *dev, struct arc_hardware *hard, 442 struct arc_rfc1201 *soft, int softlen, int bufnum) 443 { 444 struct arcnet_local *lp = netdev_priv(dev); 445 int ofs; 446 447 /* assume length <= XMTU: someone should have handled that by now. */ 448 449 if (softlen > MinTU) { 450 hard->offset[0] = 0; 451 hard->offset[1] = ofs = 512 - softlen; 452 } else if (softlen > MTU) { /* exception packet - add an extra header */ 453 struct arc_rfc1201 excsoft; 454 455 excsoft.proto = soft->proto; 456 excsoft.split_flag = 0xff; 457 excsoft.sequence = htons(0xffff); 458 459 hard->offset[0] = 0; 460 ofs = 512 - softlen; 461 hard->offset[1] = ofs - RFC1201_HDR_SIZE; 462 lp->hw.copy_to_card(dev, bufnum, ofs - RFC1201_HDR_SIZE, 463 &excsoft, RFC1201_HDR_SIZE); 464 } else 465 hard->offset[0] = ofs = 256 - softlen; 466 467 lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE); 468 lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen); 469 470 lp->lastload_dest = hard->dest; 471 } 472 473 474 static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, 475 int bufnum) 476 { 477 struct arcnet_local *lp = netdev_priv(dev); 478 const int maxsegsize = XMTU - RFC1201_HDR_SIZE; 479 struct Outgoing *out; 480 481 482 BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n", 483 lp->next_tx, lp->cur_tx, bufnum); 484 485 length -= ARC_HDR_SIZE; /* hard header is not included in packet length */ 486 pkt->soft.rfc1201.split_flag = 0; 487 488 /* need to do a split packet? */ 489 if (length > XMTU) { 490 out = &lp->outgoing; 491 492 out->length = length - RFC1201_HDR_SIZE; 493 out->dataleft = lp->outgoing.length; 494 out->numsegs = (out->dataleft + maxsegsize - 1) / maxsegsize; 495 out->segnum = 0; 496 497 BUGMSG(D_DURING, "rfc1201 prep_tx: ready for %d-segment split " 498 "(%d bytes, seq=%d)\n", out->numsegs, out->length, 499 pkt->soft.rfc1201.sequence); 500 501 return 0; /* not done */ 502 } 503 /* just load the packet into the buffers and send it off */ 504 load_pkt(dev, &pkt->hard, &pkt->soft.rfc1201, length, bufnum); 505 506 return 1; /* done */ 507 } 508 509 510 static int continue_tx(struct net_device *dev, int bufnum) 511 { 512 struct arcnet_local *lp = netdev_priv(dev); 513 struct Outgoing *out = &lp->outgoing; 514 struct arc_hardware *hard = &out->pkt->hard; 515 struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft; 516 int maxsegsize = XMTU - RFC1201_HDR_SIZE; 517 int seglen; 518 519 BUGMSG(D_DURING, 520 "rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n", 521 out->segnum, out->numsegs, soft->sequence); 522 523 /* the "new" soft header comes right before the data chunk */ 524 newsoft = (struct arc_rfc1201 *) 525 (out->pkt->soft.raw + out->length - out->dataleft); 526 527 if (!out->segnum) /* first packet; newsoft == soft */ 528 newsoft->split_flag = ((out->numsegs - 2) << 1) | 1; 529 else { 530 newsoft->split_flag = out->segnum << 1; 531 newsoft->proto = soft->proto; 532 newsoft->sequence = soft->sequence; 533 } 534 535 seglen = maxsegsize; 536 if (seglen > out->dataleft) 537 seglen = out->dataleft; 538 out->dataleft -= seglen; 539 540 load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum); 541 542 out->segnum++; 543 if (out->segnum >= out->numsegs) 544 return 1; 545 else 546 return 0; 547 } 548