Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Al Viro | 701181a | 2007-08-22 22:59:11 -0400 | [diff] [blame^] | 37 | static __be16 type_trans(struct sk_buff *skb, struct net_device *dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Adrian Bunk | f03aa2d | 2006-01-14 03:10:22 +0100 | [diff] [blame] | 46 | static struct ArcProto rfc1201_proto = |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | */ |
Al Viro | 701181a | 2007-08-22 22:59:11 -0400 | [diff] [blame^] | 91 | static __be16 type_trans(struct sk_buff *skb, struct net_device *dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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. */ |
Arnaldo Carvalho de Melo | 459a98e | 2007-03-19 15:30:44 -0700 | [diff] [blame] | 99 | skb_reset_mac_header(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ |
| 134 | static 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. */ |
| 376 | static 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 | /* |
| 430 | * FIXME: fill in the last byte of the dest ipaddr here to better |
| 431 | * comply with RFC1051 in "noarp" mode. For now, always broadcasting |
| 432 | * will probably at least get packets sent out :) |
| 433 | */ |
| 434 | pkt->hard.dest = 0; |
| 435 | return hdr_size; |
| 436 | } |
| 437 | /* otherwise, drop in the dest address */ |
| 438 | pkt->hard.dest = daddr; |
| 439 | return hdr_size; |
| 440 | } |
| 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 = dev->priv; |
| 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; |
Al Viro | 701181a | 2007-08-22 22:59:11 -0400 | [diff] [blame^] | 459 | excsoft.sequence = htons(0xffff); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE); |
| 470 | lp->hw.copy_to_card(dev, bufnum, ofs, soft, softlen); |
| 471 | |
| 472 | lp->lastload_dest = hard->dest; |
| 473 | } |
| 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 = dev->priv; |
| 480 | const int maxsegsize = XMTU - RFC1201_HDR_SIZE; |
| 481 | struct Outgoing *out; |
| 482 | |
| 483 | |
| 484 | BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n", |
| 485 | lp->next_tx, lp->cur_tx, bufnum); |
| 486 | |
| 487 | length -= ARC_HDR_SIZE; /* hard header is not included in packet length */ |
| 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 | BUGMSG(D_DURING, "rfc1201 prep_tx: ready for %d-segment split " |
| 500 | "(%d bytes, seq=%d)\n", 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, &pkt->hard, &pkt->soft.rfc1201, length, bufnum); |
| 507 | |
| 508 | return 1; /* done */ |
| 509 | } |
| 510 | |
| 511 | |
| 512 | static int continue_tx(struct net_device *dev, int bufnum) |
| 513 | { |
| 514 | struct arcnet_local *lp = dev->priv; |
| 515 | struct Outgoing *out = &lp->outgoing; |
| 516 | struct arc_hardware *hard = &out->pkt->hard; |
| 517 | struct arc_rfc1201 *soft = &out->pkt->soft.rfc1201, *newsoft; |
| 518 | int maxsegsize = XMTU - RFC1201_HDR_SIZE; |
| 519 | int seglen; |
| 520 | |
| 521 | BUGMSG(D_DURING, |
| 522 | "rfc1201 continue_tx: loading segment %d(+1) of %d (seq=%d)\n", |
| 523 | out->segnum, out->numsegs, soft->sequence); |
| 524 | |
| 525 | /* the "new" soft header comes right before the data chunk */ |
| 526 | newsoft = (struct arc_rfc1201 *) |
| 527 | (out->pkt->soft.raw + out->length - out->dataleft); |
| 528 | |
| 529 | if (!out->segnum) /* first packet; newsoft == soft */ |
| 530 | newsoft->split_flag = ((out->numsegs - 2) << 1) | 1; |
| 531 | else { |
| 532 | newsoft->split_flag = out->segnum << 1; |
| 533 | newsoft->proto = soft->proto; |
| 534 | newsoft->sequence = soft->sequence; |
| 535 | } |
| 536 | |
| 537 | seglen = maxsegsize; |
| 538 | if (seglen > out->dataleft) |
| 539 | seglen = out->dataleft; |
| 540 | out->dataleft -= seglen; |
| 541 | |
| 542 | load_pkt(dev, hard, newsoft, seglen + RFC1201_HDR_SIZE, bufnum); |
| 543 | |
| 544 | out->segnum++; |
| 545 | if (out->segnum >= out->numsegs) |
| 546 | return 1; |
| 547 | else |
| 548 | return 0; |
| 549 | } |