drivers/net/wan/dlci.c

   1 /*
   2  * DLCI         Implementation of Frame Relay protocol for Linux, according to
   3  *              RFC 1490.  This generic device provides en/decapsulation for an
   4  *              underlying hardware driver.  Routes & IPs are assigned to these
   5  *              interfaces.  Requires 'dlcicfg' program to create usable
   6  *              interfaces, the initial one, 'dlci' is for IOCTL use only.
   7  *
   8  * Version:     @(#)dlci.c      0.35    4 Jan 1997
   9  *
  10  * Author:      Mike McLagan <mike.mclagan@linux.org>
  11  *
  12  * Changes:
  13  *
  14  *              0.15    Mike Mclagan    Packet freeing, bug in kmalloc call
  15  *                                      DLCI_RET handling
  16  *              0.20    Mike McLagan    More conservative on which packets
  17  *                                      are returned for retry and which are
  18  *                                      are dropped.  If DLCI_RET_DROP is
  19  *                                      returned from the FRAD, the packet is
  20  *                                      sent back to Linux for re-transmission
  21  *              0.25    Mike McLagan    Converted to use SIOC IOCTL calls
  22  *              0.30    Jim Freeman     Fixed to allow IPX traffic
  23  *              0.35    Michael Elizabeth       Fixed incorrect memcpy_fromfs
  24  *
  25  *              This program is free software; you can redistribute it and/or
  26  *              modify it under the terms of the GNU General Public License
  27  *              as published by the Free Software Foundation; either version
  28  *              2 of the License, or (at your option) any later version.
  29  */
  30
  31 #include <linux/module.h>
  32 #include <linux/kernel.h>
  33 #include <linux/types.h>
  34 #include <linux/fcntl.h>
  35 #include <linux/interrupt.h>
  36 #include <linux/ptrace.h>
  37 #include <linux/ioport.h>
  38 #include <linux/in.h>
  39 #include <linux/init.h>
  40 #include <linux/slab.h>
  41 #include <linux/string.h>
  42 #include <linux/errno.h>
  43 #include <linux/netdevice.h>
  44 #include <linux/skbuff.h>
  45 #include <linux/if_arp.h>
  46 #include <linux/if_frad.h>
  47 #include <linux/bitops.h>
  48
  49 #include <net/sock.h>
  50
  51 #include <asm/system.h>
  52 #include <asm/io.h>
  53 #include <asm/dma.h>
  54 #include <asm/uaccess.h>
  55
  56 static const char version[] = "DLCI driver v0.35, 4 Jan 1997, mike.mclagan@linux.org";
  57
  58 static LIST_HEAD(dlci_devs);
  59
  60 static void dlci_setup(struct net_device *);
  61
  62 /*
  63  * these encapsulate the RFC 1490 requirements as well as
  64  * deal with packet transmission and reception, working with
  65  * the upper network layers
  66  */
  67
  68 static int dlci_header(struct sk_buff *skb, struct net_device *dev,
  69                        unsigned short type, const void *daddr,
  70                        const void *saddr, unsigned len)
  71 {
  72         struct frhdr            hdr;
  73         struct dlci_local       *dlp;
  74         unsigned int            hlen;
  75         char                    *dest;
  76
  77         dlp = dev->priv;
  78
  79         hdr.control = FRAD_I_UI;
  80         switch(type)
  81         {
  82                 case ETH_P_IP:
  83                         hdr.IP_NLPID = FRAD_P_IP;
  84                         hlen = sizeof(hdr.control) + sizeof(hdr.IP_NLPID);
  85                         break;
  86
  87                 /* feel free to add other types, if necessary */
  88
  89                 default:
  90                         hdr.pad = FRAD_P_PADDING;
  91                         hdr.NLPID = FRAD_P_SNAP;
  92                         memset(hdr.OUI, 0, sizeof(hdr.OUI));
  93                         hdr.PID = htons(type);
  94                         hlen = sizeof(hdr);
  95                         break;
  96         }
  97
  98         dest = skb_push(skb, hlen);
  99         if (!dest)
 100                 return(0);
 101
 102         memcpy(dest, &hdr, hlen);
 103
 104         return(hlen);
 105 }
 106
 107 static void dlci_receive(struct sk_buff *skb, struct net_device *dev)
 108 {
 109         struct dlci_local *dlp;
 110         struct frhdr            *hdr;
 111         int                                     process, header;
 112
 113         dlp = dev->priv;
 114         if (!pskb_may_pull(skb, sizeof(*hdr))) {
 115                 printk(KERN_NOTICE "%s: invalid data no header\n",
 116                        dev->name);
 117                 dlp->stats.rx_errors++;
 118                 kfree_skb(skb);
 119                 return;
 120         }
 121
 122         hdr = (struct frhdr *) skb->data;
 123         process = 0;
 124         header = 0;
 125         skb->dev = dev;
 126
 127         if (hdr->control != FRAD_I_UI)
 128         {
 129                 printk(KERN_NOTICE "%s: Invalid header flag 0x%02X.\n", dev->name, hdr->control);
 130                 dlp->stats.rx_errors++;
 131         }
 132         else
 133                 switch(hdr->IP_NLPID)
 134                 {
 135                         case FRAD_P_PADDING:
 136                                 if (hdr->NLPID != FRAD_P_SNAP)
 137                                 {
 138                                         printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->NLPID);
 139                                         dlp->stats.rx_errors++;
 140                                         break;
 141                                 }
 142
 143                                 if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
 144                                 {
 145                                         printk(KERN_NOTICE "%s: Unsupported organizationally unique identifier 0x%02X-%02X-%02X.\n", dev->name, hdr->OUI[0], hdr->OUI[1], hdr->OUI[2]);
 146                                         dlp->stats.rx_errors++;
 147                                         break;
 148                                 }
 149
 150                                 /* at this point, it's an EtherType frame */
 151                                 header = sizeof(struct frhdr);
 152                                 /* Already in network order ! */
 153                                 skb->protocol = hdr->PID;
 154                                 process = 1;
 155                                 break;
 156
 157                         case FRAD_P_IP:
 158                                 header = sizeof(hdr->control) + sizeof(hdr->IP_NLPID);
 159                                 skb->protocol = htons(ETH_P_IP);
 160                                 process = 1;
 161                                 break;
 162
 163                         case FRAD_P_SNAP:
 164                         case FRAD_P_Q933:
 165                         case FRAD_P_CLNP:
 166                                 printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->pad);
 167                                 dlp->stats.rx_errors++;
 168                                 break;
 169
 170                         default:
 171                                 printk(KERN_NOTICE "%s: Invalid pad byte 0x%02X.\n", dev->name, hdr->pad);
 172                                 dlp->stats.rx_errors++;
 173                                 break;
 174                 }
 175
 176         if (process)
 177         {
 178                 /* we've set up the protocol, so discard the header */
 179                 skb_reset_mac_header(skb);
 180                 skb_pull(skb, header);
 181                 dlp->stats.rx_bytes += skb->len;
 182                 netif_rx(skb);
 183                 dlp->stats.rx_packets++;
 184                 dev->last_rx = jiffies;
 185         }
 186         else
 187                 dev_kfree_skb(skb);
 188 }
 189
 190 static int dlci_transmit(struct sk_buff *skb, struct net_device *dev)
 191 {
 192         struct dlci_local *dlp;
 193         int                                     ret;
 194
 195         ret = 0;
 196
 197         if (!skb || !dev)
 198                 return(0);
 199
 200         dlp = dev->priv;
 201
 202         netif_stop_queue(dev);
 203
 204         ret = dlp->slave->hard_start_xmit(skb, dlp->slave);
 205         switch (ret)
 206         {
 207                 case DLCI_RET_OK:
 208                         dlp->stats.tx_packets++;
 209                         ret = 0;
 210                         break;
 211                         case DLCI_RET_ERR:
 212                         dlp->stats.tx_errors++;
 213                         ret = 0;
 214                         break;
 215                         case DLCI_RET_DROP:
 216                         dlp->stats.tx_dropped++;
 217                         ret = 1;
 218                         break;
 219         }
 220         /* Alan Cox recommends always returning 0, and always freeing the packet */
 221         /* experience suggest a slightly more conservative approach */
 222
 223         if (!ret)
 224         {
 225                 dev_kfree_skb(skb);
 226                 netif_wake_queue(dev);
 227         }
 228         return(ret);
 229 }
 230
 231 static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
 232 {
 233         struct dlci_conf        config;
 234         struct dlci_local       *dlp;
 235         struct frad_local       *flp;
 236         int                     err;
 237
 238         dlp = dev->priv;
 239
 240         flp = dlp->slave->priv;
 241
 242         if (!get)
 243         {
 244                 if(copy_from_user(&config, conf, sizeof(struct dlci_conf)))
 245                         return -EFAULT;
 246                 if (config.flags & ~DLCI_VALID_FLAGS)
 247                         return(-EINVAL);
 248                 memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
 249                 dlp->configured = 1;
 250         }
 251
 252         err = (*flp->dlci_conf)(dlp->slave, dev, get);
 253         if (err)
 254                 return(err);
 255
 256         if (get)
 257         {
 258                 if(copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
 259                         return -EFAULT;
 260         }
 261
 262         return(0);
 263 }
 264
 265 static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 266 {
 267         struct dlci_local *dlp;
 268
 269         if (!capable(CAP_NET_ADMIN))
 270                 return(-EPERM);
 271
 272         dlp = dev->priv;
 273
 274         switch(cmd)
 275         {
 276                 case DLCI_GET_SLAVE:
 277                         if (!*(short *)(dev->dev_addr))
 278                                 return(-EINVAL);
 279
 280                         strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
 281                         break;
 282
 283                 case DLCI_GET_CONF:
 284                 case DLCI_SET_CONF:
 285                         if (!*(short *)(dev->dev_addr))
 286                                 return(-EINVAL);
 287
 288                         return(dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF));
 289                         break;
 290
 291                 default:
 292                         return(-EOPNOTSUPP);
 293         }
 294         return(0);
 295 }
 296
 297 static int dlci_change_mtu(struct net_device *dev, int new_mtu)
 298 {
 299         struct dlci_local *dlp;
 300
 301         dlp = dev->priv;
 302
 303         return((*dlp->slave->change_mtu)(dlp->slave, new_mtu));
 304 }
 305
 306 static int dlci_open(struct net_device *dev)
 307 {
 308         struct dlci_local       *dlp;
 309         struct frad_local       *flp;
 310         int                     err;
 311
 312         dlp = dev->priv;
 313
 314         if (!*(short *)(dev->dev_addr))
 315                 return(-EINVAL);
 316
 317         if (!netif_running(dlp->slave))
 318                 return(-ENOTCONN);
 319
 320         flp = dlp->slave->priv;
 321         err = (*flp->activate)(dlp->slave, dev);
 322         if (err)
 323                 return(err);
 324
 325         netif_start_queue(dev);
 326
 327         return 0;
 328 }
 329
 330 static int dlci_close(struct net_device *dev)
 331 {
 332         struct dlci_local       *dlp;
 333         struct frad_local       *flp;
 334         int                     err;
 335
 336         netif_stop_queue(dev);
 337
 338         dlp = dev->priv;
 339
 340         flp = dlp->slave->priv;
 341         err = (*flp->deactivate)(dlp->slave, dev);
 342
 343         return 0;
 344 }
 345
 346 static struct net_device_stats *dlci_get_stats(struct net_device *dev)
 347 {
 348         struct dlci_local *dlp;
 349
 350         dlp = dev->priv;
 351
 352         return(&dlp->stats);
 353 }
 354
 355 static int dlci_add(struct dlci_add *dlci)
 356 {
 357         struct net_device       *master, *slave;
 358         struct dlci_local       *dlp;
 359         struct frad_local       *flp;
 360         int                     err = -EINVAL;
 361
 362
 363         /* validate slave device */
 364         slave = dev_get_by_name(&init_net, dlci->devname);
 365         if (!slave)
 366                 return -ENODEV;
 367
 368         if (slave->type != ARPHRD_FRAD || slave->priv == NULL)
 369                 goto err1;
 370
 371         /* create device name */
 372         master = alloc_netdev( sizeof(struct dlci_local), "dlci%d",
 373                               dlci_setup);
 374         if (!master) {
 375                 err = -ENOMEM;
 376                 goto err1;
 377         }
 378
 379         /* make sure same slave not already registered */
 380         rtnl_lock();
 381         list_for_each_entry(dlp, &dlci_devs, list) {
 382                 if (dlp->slave == slave) {
 383                         err = -EBUSY;
 384                         goto err2;
 385                 }
 386         }
 387
 388         err = dev_alloc_name(master, master->name);
 389         if (err < 0)
 390                 goto err2;
 391
 392         *(short *)(master->dev_addr) = dlci->dlci;
 393
 394         dlp = (struct dlci_local *) master->priv;
 395         dlp->slave = slave;
 396         dlp->master = master;
 397
 398         flp = slave->priv;
 399         err = (*flp->assoc)(slave, master);
 400         if (err < 0)
 401                 goto err2;
 402
 403         err = register_netdevice(master);
 404         if (err < 0)
 405                 goto err2;
 406
 407         strcpy(dlci->devname, master->name);
 408
 409         list_add(&dlp->list, &dlci_devs);
 410         rtnl_unlock();
 411
 412         return(0);
 413
 414  err2:
 415         rtnl_unlock();
 416         free_netdev(master);
 417  err1:
 418         dev_put(slave);
 419         return(err);
 420 }
 421
 422 static int dlci_del(struct dlci_add *dlci)
 423 {
 424         struct dlci_local       *dlp;
 425         struct frad_local       *flp;
 426         struct net_device       *master, *slave;
 427         int                     err;
 428
 429         /* validate slave device */
 430         master = __dev_get_by_name(&init_net, dlci->devname);
 431         if (!master)
 432                 return(-ENODEV);
 433
 434         if (netif_running(master)) {
 435                 return(-EBUSY);
 436         }
 437
 438         dlp = master->priv;
 439         slave = dlp->slave;
 440         flp = slave->priv;
 441
 442         rtnl_lock();
 443         err = (*flp->deassoc)(slave, master);
 444         if (!err) {
 445                 list_del(&dlp->list);
 446
 447                 unregister_netdevice(master);
 448
 449                 dev_put(slave);
 450         }
 451         rtnl_unlock();
 452
 453         return(err);
 454 }
 455
 456 static int dlci_ioctl(unsigned int cmd, void __user *arg)
 457 {
 458         struct dlci_add add;
 459         int err;
 460
 461         if (!capable(CAP_NET_ADMIN))
 462                 return(-EPERM);
 463
 464         if(copy_from_user(&add, arg, sizeof(struct dlci_add)))
 465                 return -EFAULT;
 466
 467         switch (cmd)
 468         {
 469                 case SIOCADDDLCI:
 470                         err = dlci_add(&add);
 471
 472                         if (!err)
 473                                 if(copy_to_user(arg, &add, sizeof(struct dlci_add)))
 474                                         return -EFAULT;
 475                         break;
 476
 477                 case SIOCDELDLCI:
 478                         err = dlci_del(&add);
 479                         break;
 480
 481                 default:
 482                         err = -EINVAL;
 483         }
 484
 485         return(err);
 486 }
 487
 488 static const struct header_ops dlci_header_ops = {
 489         .create = dlci_header,
 490 };
 491
 492 static void dlci_setup(struct net_device *dev)
 493 {
 494         struct dlci_local *dlp = dev->priv;
 495
 496         dev->flags              = 0;
 497         dev->open               = dlci_open;
 498         dev->stop               = dlci_close;
 499         dev->do_ioctl           = dlci_dev_ioctl;
 500         dev->hard_start_xmit    = dlci_transmit;
 501         dev->header_ops         = &dlci_header_ops;
 502         dev->get_stats          = dlci_get_stats;
 503         dev->change_mtu         = dlci_change_mtu;
 504         dev->destructor         = free_netdev;
 505
 506         dlp->receive            = dlci_receive;
 507
 508         dev->type               = ARPHRD_DLCI;
 509         dev->hard_header_len    = sizeof(struct frhdr);
 510         dev->addr_len           = sizeof(short);
 511
 512 }
 513
 514 /* if slave is unregistering, then cleanup master */
 515 static int dlci_dev_event(struct notifier_block *unused,
 516                           unsigned long event, void *ptr)
 517 {
 518         struct net_device *dev = (struct net_device *) ptr;
 519
 520         if (dev->nd_net != &init_net)
 521                 return NOTIFY_DONE;
 522
 523         if (event == NETDEV_UNREGISTER) {
 524                 struct dlci_local *dlp;
 525
 526                 list_for_each_entry(dlp, &dlci_devs, list) {
 527                         if (dlp->slave == dev) {
 528                                 list_del(&dlp->list);
 529                                 unregister_netdevice(dlp->master);
 530                                 dev_put(dlp->slave);
 531                                 break;
 532                         }
 533                 }
 534         }
 535         return NOTIFY_DONE;
 536 }
 537
 538 static struct notifier_block dlci_notifier = {
 539         .notifier_call = dlci_dev_event,
 540 };
 541
 542 static int __init init_dlci(void)
 543 {
 544         dlci_ioctl_set(dlci_ioctl);
 545         register_netdevice_notifier(&dlci_notifier);
 546
 547         printk("%s.\n", version);
 548
 549         return 0;
 550 }
 551
 552 static void __exit dlci_exit(void)
 553 {
 554         struct dlci_local       *dlp, *nxt;
 555
 556         dlci_ioctl_set(NULL);
 557         unregister_netdevice_notifier(&dlci_notifier);
 558
 559         rtnl_lock();
 560         list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
 561                 unregister_netdevice(dlp->master);
 562                 dev_put(dlp->slave);
 563         }
 564         rtnl_unlock();
 565 }
 566
 567 module_init(init_dlci);
 568 module_exit(dlci_exit);
 569
 570 MODULE_AUTHOR("Mike McLagan");
 571 MODULE_DESCRIPTION("Frame Relay DLCI layer");
 572 MODULE_LICENSE("GPL");