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 = netdev_priv(dev);
  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 = netdev_priv(dev);
 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         }
 185         else
 186                 dev_kfree_skb(skb);
 187 }
 188
 189 static int dlci_transmit(struct sk_buff *skb, struct net_device *dev)
 190 {
 191         struct dlci_local *dlp;
 192         int                                     ret;
 193
 194         ret = 0;
 195
 196         if (!skb || !dev)
 197                 return(0);
 198
 199         dlp = netdev_priv(dev);
 200
 201         netif_stop_queue(dev);
 202
 203         ret = dlp->slave->hard_start_xmit(skb, dlp->slave);
 204         switch (ret)
 205         {
 206                 case DLCI_RET_OK:
 207                         dlp->stats.tx_packets++;
 208                         ret = 0;
 209                         break;
 210                         case DLCI_RET_ERR:
 211                         dlp->stats.tx_errors++;
 212                         ret = 0;
 213                         break;
 214                         case DLCI_RET_DROP:
 215                         dlp->stats.tx_dropped++;
 216                         ret = 1;
 217                         break;
 218         }
 219         /* Alan Cox recommends always returning 0, and always freeing the packet */
 220         /* experience suggest a slightly more conservative approach */
 221
 222         if (!ret)
 223         {
 224                 dev_kfree_skb(skb);
 225                 netif_wake_queue(dev);
 226         }
 227         return(ret);
 228 }
 229
 230 static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
 231 {
 232         struct dlci_conf        config;
 233         struct dlci_local       *dlp;
 234         struct frad_local       *flp;
 235         int                     err;
 236
 237         dlp = netdev_priv(dev);
 238
 239         flp = netdev_priv(dlp->slave);
 240
 241         if (!get)
 242         {
 243                 if(copy_from_user(&config, conf, sizeof(struct dlci_conf)))
 244                         return -EFAULT;
 245                 if (config.flags & ~DLCI_VALID_FLAGS)
 246                         return(-EINVAL);
 247                 memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
 248                 dlp->configured = 1;
 249         }
 250
 251         err = (*flp->dlci_conf)(dlp->slave, dev, get);
 252         if (err)
 253                 return(err);
 254
 255         if (get)
 256         {
 257                 if(copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
 258                         return -EFAULT;
 259         }
 260
 261         return(0);
 262 }
 263
 264 static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 265 {
 266         struct dlci_local *dlp;
 267
 268         if (!capable(CAP_NET_ADMIN))
 269                 return(-EPERM);
 270
 271         dlp = netdev_priv(dev);
 272
 273         switch(cmd)
 274         {
 275                 case DLCI_GET_SLAVE:
 276                         if (!*(short *)(dev->dev_addr))
 277                                 return(-EINVAL);
 278
 279                         strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
 280                         break;
 281
 282                 case DLCI_GET_CONF:
 283                 case DLCI_SET_CONF:
 284                         if (!*(short *)(dev->dev_addr))
 285                                 return(-EINVAL);
 286
 287                         return(dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF));
 288                         break;
 289
 290                 default:
 291                         return(-EOPNOTSUPP);
 292         }
 293         return(0);
 294 }
 295
 296 static int dlci_change_mtu(struct net_device *dev, int new_mtu)
 297 {
 298         struct dlci_local *dlp;
 299
 300         dlp = netdev_priv(dev);
 301
 302         return((*dlp->slave->change_mtu)(dlp->slave, new_mtu));
 303 }
 304
 305 static int dlci_open(struct net_device *dev)
 306 {
 307         struct dlci_local       *dlp;
 308         struct frad_local       *flp;
 309         int                     err;
 310
 311         dlp = netdev_priv(dev);
 312
 313         if (!*(short *)(dev->dev_addr))
 314                 return(-EINVAL);
 315
 316         if (!netif_running(dlp->slave))
 317                 return(-ENOTCONN);
 318
 319         flp = netdev_priv(dlp->slave);
 320         err = (*flp->activate)(dlp->slave, dev);
 321         if (err)
 322                 return(err);
 323
 324         netif_start_queue(dev);
 325
 326         return 0;
 327 }
 328
 329 static int dlci_close(struct net_device *dev)
 330 {
 331         struct dlci_local       *dlp;
 332         struct frad_local       *flp;
 333         int                     err;
 334
 335         netif_stop_queue(dev);
 336
 337         dlp = netdev_priv(dev);
 338
 339         flp = netdev_priv(dlp->slave);
 340         err = (*flp->deactivate)(dlp->slave, dev);
 341
 342         return 0;
 343 }
 344
 345 static struct net_device_stats *dlci_get_stats(struct net_device *dev)
 346 {
 347         struct dlci_local *dlp;
 348
 349         dlp = netdev_priv(dev);
 350
 351         return(&dlp->stats);
 352 }
 353
 354 static int dlci_add(struct dlci_add *dlci)
 355 {
 356         struct net_device       *master, *slave;
 357         struct dlci_local       *dlp;
 358         struct frad_local       *flp;
 359         int                     err = -EINVAL;
 360
 361
 362         /* validate slave device */
 363         slave = dev_get_by_name(&init_net, dlci->devname);
 364         if (!slave)
 365                 return -ENODEV;
 366
 367         if (slave->type != ARPHRD_FRAD || netdev_priv(slave) == NULL)
 368                 goto err1;
 369
 370         /* create device name */
 371         master = alloc_netdev( sizeof(struct dlci_local), "dlci%d",
 372                               dlci_setup);
 373         if (!master) {
 374                 err = -ENOMEM;
 375                 goto err1;
 376         }
 377
 378         /* make sure same slave not already registered */
 379         rtnl_lock();
 380         list_for_each_entry(dlp, &dlci_devs, list) {
 381                 if (dlp->slave == slave) {
 382                         err = -EBUSY;
 383                         goto err2;
 384                 }
 385         }
 386
 387         err = dev_alloc_name(master, master->name);
 388         if (err < 0)
 389                 goto err2;
 390
 391         *(short *)(master->dev_addr) = dlci->dlci;
 392
 393         dlp = netdev_priv(master);
 394         dlp->slave = slave;
 395         dlp->master = master;
 396
 397         flp = netdev_priv(slave);
 398         err = (*flp->assoc)(slave, master);
 399         if (err < 0)
 400                 goto err2;
 401
 402         err = register_netdevice(master);
 403         if (err < 0)
 404                 goto err2;
 405
 406         strcpy(dlci->devname, master->name);
 407
 408         list_add(&dlp->list, &dlci_devs);
 409         rtnl_unlock();
 410
 411         return(0);
 412
 413  err2:
 414         rtnl_unlock();
 415         free_netdev(master);
 416  err1:
 417         dev_put(slave);
 418         return(err);
 419 }
 420
 421 static int dlci_del(struct dlci_add *dlci)
 422 {
 423         struct dlci_local       *dlp;
 424         struct frad_local       *flp;
 425         struct net_device       *master, *slave;
 426         int                     err;
 427
 428         /* validate slave device */
 429         master = __dev_get_by_name(&init_net, dlci->devname);
 430         if (!master)
 431                 return(-ENODEV);
 432
 433         if (netif_running(master)) {
 434                 return(-EBUSY);
 435         }
 436
 437         dlp = netdev_priv(master);
 438         slave = dlp->slave;
 439         flp = netdev_priv(slave);
 440
 441         rtnl_lock();
 442         err = (*flp->deassoc)(slave, master);
 443         if (!err) {
 444                 list_del(&dlp->list);
 445
 446                 unregister_netdevice(master);
 447
 448                 dev_put(slave);
 449         }
 450         rtnl_unlock();
 451
 452         return(err);
 453 }
 454
 455 static int dlci_ioctl(unsigned int cmd, void __user *arg)
 456 {
 457         struct dlci_add add;
 458         int err;
 459
 460         if (!capable(CAP_NET_ADMIN))
 461                 return(-EPERM);
 462
 463         if(copy_from_user(&add, arg, sizeof(struct dlci_add)))
 464                 return -EFAULT;
 465
 466         switch (cmd)
 467         {
 468                 case SIOCADDDLCI:
 469                         err = dlci_add(&add);
 470
 471                         if (!err)
 472                                 if(copy_to_user(arg, &add, sizeof(struct dlci_add)))
 473                                         return -EFAULT;
 474                         break;
 475
 476                 case SIOCDELDLCI:
 477                         err = dlci_del(&add);
 478                         break;
 479
 480                 default:
 481                         err = -EINVAL;
 482         }
 483
 484         return(err);
 485 }
 486
 487 static const struct header_ops dlci_header_ops = {
 488         .create = dlci_header,
 489 };
 490
 491 static void dlci_setup(struct net_device *dev)
 492 {
 493         struct dlci_local *dlp = netdev_priv(dev);
 494
 495         dev->flags              = 0;
 496         dev->open               = dlci_open;
 497         dev->stop               = dlci_close;
 498         dev->do_ioctl           = dlci_dev_ioctl;
 499         dev->hard_start_xmit    = dlci_transmit;
 500         dev->header_ops         = &dlci_header_ops;
 501         dev->get_stats          = dlci_get_stats;
 502         dev->change_mtu         = dlci_change_mtu;
 503         dev->destructor         = free_netdev;
 504
 505         dlp->receive            = dlci_receive;
 506
 507         dev->type               = ARPHRD_DLCI;
 508         dev->hard_header_len    = sizeof(struct frhdr);
 509         dev->addr_len           = sizeof(short);
 510
 511 }
 512
 513 /* if slave is unregistering, then cleanup master */
 514 static int dlci_dev_event(struct notifier_block *unused,
 515                           unsigned long event, void *ptr)
 516 {
 517         struct net_device *dev = (struct net_device *) ptr;
 518
 519         if (dev_net(dev) != &init_net)
 520                 return NOTIFY_DONE;
 521
 522         if (event == NETDEV_UNREGISTER) {
 523                 struct dlci_local *dlp;
 524
 525                 list_for_each_entry(dlp, &dlci_devs, list) {
 526                         if (dlp->slave == dev) {
 527                                 list_del(&dlp->list);
 528                                 unregister_netdevice(dlp->master);
 529                                 dev_put(dlp->slave);
 530                                 break;
 531                         }
 532                 }
 533         }
 534         return NOTIFY_DONE;
 535 }
 536
 537 static struct notifier_block dlci_notifier = {
 538         .notifier_call = dlci_dev_event,
 539 };
 540
 541 static int __init init_dlci(void)
 542 {
 543         dlci_ioctl_set(dlci_ioctl);
 544         register_netdevice_notifier(&dlci_notifier);
 545
 546         printk("%s.\n", version);
 547
 548         return 0;
 549 }
 550
 551 static void __exit dlci_exit(void)
 552 {
 553         struct dlci_local       *dlp, *nxt;
 554
 555         dlci_ioctl_set(NULL);
 556         unregister_netdevice_notifier(&dlci_notifier);
 557
 558         rtnl_lock();
 559         list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
 560                 unregister_netdevice(dlp->master);
 561                 dev_put(dlp->slave);
 562         }
 563         rtnl_unlock();
 564 }
 565
 566 module_init(init_dlci);
 567 module_exit(dlci_exit);
 568
 569 MODULE_AUTHOR("Mike McLagan");
 570 MODULE_DESCRIPTION("Frame Relay DLCI layer");
 571 MODULE_LICENSE("GPL");