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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  32
  33 #include <linux/module.h>
  34 #include <linux/kernel.h>
  35 #include <linux/types.h>
  36 #include <linux/fcntl.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/ptrace.h>
  39 #include <linux/ioport.h>
  40 #include <linux/in.h>
  41 #include <linux/init.h>
  42 #include <linux/slab.h>
  43 #include <linux/string.h>
  44 #include <linux/errno.h>
  45 #include <linux/netdevice.h>
  46 #include <linux/skbuff.h>
  47 #include <linux/if_arp.h>
  48 #include <linux/if_frad.h>
  49 #include <linux/bitops.h>
  50
  51 #include <net/sock.h>
  52
  53 #include <asm/io.h>
  54 #include <asm/dma.h>
  55 #include <asm/uaccess.h>
  56
  57 static const char version[] = "DLCI driver v0.35, 4 Jan 1997, mike.mclagan@linux.org";
  58
  59 static LIST_HEAD(dlci_devs);
  60
  61 static void dlci_setup(struct net_device *);
  62
  63 /*
  64  * these encapsulate the RFC 1490 requirements as well as
  65  * deal with packet transmission and reception, working with
  66  * the upper network layers
  67  */
  68
  69 static int dlci_header(struct sk_buff *skb, struct net_device *dev,
  70                        unsigned short type, const void *daddr,
  71                        const void *saddr, unsigned len)
  72 {
  73         struct frhdr            hdr;
  74         struct dlci_local       *dlp;
  75         unsigned int            hlen;
  76         char                    *dest;
  77
  78         dlp = netdev_priv(dev);
  79
  80         hdr.control = FRAD_I_UI;
  81         switch (type)
  82         {
  83                 case ETH_P_IP:
  84                         hdr.IP_NLPID = FRAD_P_IP;
  85                         hlen = sizeof(hdr.control) + sizeof(hdr.IP_NLPID);
  86                         break;
  87
  88                 /* feel free to add other types, if necessary */
  89
  90                 default:
  91                         hdr.pad = FRAD_P_PADDING;
  92                         hdr.NLPID = FRAD_P_SNAP;
  93                         memset(hdr.OUI, 0, sizeof(hdr.OUI));
  94                         hdr.PID = htons(type);
  95                         hlen = sizeof(hdr);
  96                         break;
  97         }
  98
  99         dest = skb_push(skb, hlen);
 100         if (!dest)
 101                 return 0;
 102
 103         memcpy(dest, &hdr, hlen);
 104
 105         return hlen;
 106 }
 107
 108 static void dlci_receive(struct sk_buff *skb, struct net_device *dev)
 109 {
 110         struct dlci_local *dlp;
 111         struct frhdr            *hdr;
 112         int                                     process, header;
 113
 114         dlp = netdev_priv(dev);
 115         if (!pskb_may_pull(skb, sizeof(*hdr))) {
 116                 netdev_notice(dev, "invalid data no header\n");
 117                 dev->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                 netdev_notice(dev, "Invalid header flag 0x%02X\n",
 130                               hdr->control);
 131                 dev->stats.rx_errors++;
 132         }
 133         else
 134                 switch (hdr->IP_NLPID)
 135                 {
 136                         case FRAD_P_PADDING:
 137                                 if (hdr->NLPID != FRAD_P_SNAP)
 138                                 {
 139                                         netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
 140                                                       hdr->NLPID);
 141                                         dev->stats.rx_errors++;
 142                                         break;
 143                                 }
 144
 145                                 if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
 146                                 {
 147                                         netdev_notice(dev, "Unsupported organizationally unique identifier 0x%02X-%02X-%02X\n",
 148                                                       hdr->OUI[0],
 149                                                       hdr->OUI[1],
 150                                                       hdr->OUI[2]);
 151                                         dev->stats.rx_errors++;
 152                                         break;
 153                                 }
 154
 155                                 /* at this point, it's an EtherType frame */
 156                                 header = sizeof(struct frhdr);
 157                                 /* Already in network order ! */
 158                                 skb->protocol = hdr->PID;
 159                                 process = 1;
 160                                 break;
 161
 162                         case FRAD_P_IP:
 163                                 header = sizeof(hdr->control) + sizeof(hdr->IP_NLPID);
 164                                 skb->protocol = htons(ETH_P_IP);
 165                                 process = 1;
 166                                 break;
 167
 168                         case FRAD_P_SNAP:
 169                         case FRAD_P_Q933:
 170                         case FRAD_P_CLNP:
 171                                 netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
 172                                               hdr->pad);
 173                                 dev->stats.rx_errors++;
 174                                 break;
 175
 176                         default:
 177                                 netdev_notice(dev, "Invalid pad byte 0x%02X\n",
 178                                               hdr->pad);
 179                                 dev->stats.rx_errors++;
 180                                 break;
 181                 }
 182
 183         if (process)
 184         {
 185                 /* we've set up the protocol, so discard the header */
 186                 skb_reset_mac_header(skb);
 187                 skb_pull(skb, header);
 188                 dev->stats.rx_bytes += skb->len;
 189                 netif_rx(skb);
 190                 dev->stats.rx_packets++;
 191         }
 192         else
 193                 dev_kfree_skb(skb);
 194 }
 195
 196 static netdev_tx_t dlci_transmit(struct sk_buff *skb, struct net_device *dev)
 197 {
 198         struct dlci_local *dlp = netdev_priv(dev);
 199
 200         if (skb)
 201                 dlp->slave->netdev_ops->ndo_start_xmit(skb, dlp->slave);
 202         return NETDEV_TX_OK;
 203 }
 204
 205 static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
 206 {
 207         struct dlci_conf        config;
 208         struct dlci_local       *dlp;
 209         struct frad_local       *flp;
 210         int                     err;
 211
 212         dlp = netdev_priv(dev);
 213
 214         flp = netdev_priv(dlp->slave);
 215
 216         if (!get)
 217         {
 218                 if (copy_from_user(&config, conf, sizeof(struct dlci_conf)))
 219                         return -EFAULT;
 220                 if (config.flags & ~DLCI_VALID_FLAGS)
 221                         return -EINVAL;
 222                 memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
 223                 dlp->configured = 1;
 224         }
 225
 226         err = (*flp->dlci_conf)(dlp->slave, dev, get);
 227         if (err)
 228                 return err;
 229
 230         if (get)
 231         {
 232                 if (copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
 233                         return -EFAULT;
 234         }
 235
 236         return 0;
 237 }
 238
 239 static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 240 {
 241         struct dlci_local *dlp;
 242
 243         if (!capable(CAP_NET_ADMIN))
 244                 return -EPERM;
 245
 246         dlp = netdev_priv(dev);
 247
 248         switch (cmd)
 249         {
 250                 case DLCI_GET_SLAVE:
 251                         if (!*(short *)(dev->dev_addr))
 252                                 return -EINVAL;
 253
 254                         strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
 255                         break;
 256
 257                 case DLCI_GET_CONF:
 258                 case DLCI_SET_CONF:
 259                         if (!*(short *)(dev->dev_addr))
 260                                 return -EINVAL;
 261
 262                         return dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF);
 263                         break;
 264
 265                 default:
 266                         return -EOPNOTSUPP;
 267         }
 268         return 0;
 269 }
 270
 271 static int dlci_change_mtu(struct net_device *dev, int new_mtu)
 272 {
 273         struct dlci_local *dlp = netdev_priv(dev);
 274
 275         return dev_set_mtu(dlp->slave, new_mtu);
 276 }
 277
 278 static int dlci_open(struct net_device *dev)
 279 {
 280         struct dlci_local       *dlp;
 281         struct frad_local       *flp;
 282         int                     err;
 283
 284         dlp = netdev_priv(dev);
 285
 286         if (!*(short *)(dev->dev_addr))
 287                 return -EINVAL;
 288
 289         if (!netif_running(dlp->slave))
 290                 return -ENOTCONN;
 291
 292         flp = netdev_priv(dlp->slave);
 293         err = (*flp->activate)(dlp->slave, dev);
 294         if (err)
 295                 return err;
 296
 297         netif_start_queue(dev);
 298
 299         return 0;
 300 }
 301
 302 static int dlci_close(struct net_device *dev)
 303 {
 304         struct dlci_local       *dlp;
 305         struct frad_local       *flp;
 306         int                     err;
 307
 308         netif_stop_queue(dev);
 309
 310         dlp = netdev_priv(dev);
 311
 312         flp = netdev_priv(dlp->slave);
 313         err = (*flp->deactivate)(dlp->slave, dev);
 314
 315         return 0;
 316 }
 317
 318 static int dlci_add(struct dlci_add *dlci)
 319 {
 320         struct net_device       *master, *slave;
 321         struct dlci_local       *dlp;
 322         struct frad_local       *flp;
 323         int                     err = -EINVAL;
 324
 325
 326         /* validate slave device */
 327         slave = dev_get_by_name(&init_net, dlci->devname);
 328         if (!slave)
 329                 return -ENODEV;
 330
 331         if (slave->type != ARPHRD_FRAD || netdev_priv(slave) == NULL)
 332                 goto err1;
 333
 334         /* create device name */
 335         master = alloc_netdev( sizeof(struct dlci_local), "dlci%d",
 336                               dlci_setup);
 337         if (!master) {
 338                 err = -ENOMEM;
 339                 goto err1;
 340         }
 341
 342         /* make sure same slave not already registered */
 343         rtnl_lock();
 344         list_for_each_entry(dlp, &dlci_devs, list) {
 345                 if (dlp->slave == slave) {
 346                         err = -EBUSY;
 347                         goto err2;
 348                 }
 349         }
 350
 351         *(short *)(master->dev_addr) = dlci->dlci;
 352
 353         dlp = netdev_priv(master);
 354         dlp->slave = slave;
 355         dlp->master = master;
 356
 357         flp = netdev_priv(slave);
 358         err = (*flp->assoc)(slave, master);
 359         if (err < 0)
 360                 goto err2;
 361
 362         err = register_netdevice(master);
 363         if (err < 0)
 364                 goto err2;
 365
 366         strcpy(dlci->devname, master->name);
 367
 368         list_add(&dlp->list, &dlci_devs);
 369         rtnl_unlock();
 370
 371         return 0;
 372
 373  err2:
 374         rtnl_unlock();
 375         free_netdev(master);
 376  err1:
 377         dev_put(slave);
 378         return err;
 379 }
 380
 381 static int dlci_del(struct dlci_add *dlci)
 382 {
 383         struct dlci_local       *dlp;
 384         struct frad_local       *flp;
 385         struct net_device       *master, *slave;
 386         int                     err;
 387         bool                    found = false;
 388
 389         rtnl_lock();
 390
 391         /* validate slave device */
 392         master = __dev_get_by_name(&init_net, dlci->devname);
 393         if (!master) {
 394                 err = -ENODEV;
 395                 goto out;
 396         }
 397
 398         list_for_each_entry(dlp, &dlci_devs, list) {
 399                 if (dlp->master == master) {
 400                         found = true;
 401                         break;
 402                 }
 403         }
 404         if (!found) {
 405                 err = -ENODEV;
 406                 goto out;
 407         }
 408
 409         if (netif_running(master)) {
 410                 err = -EBUSY;
 411                 goto out;
 412         }
 413
 414         dlp = netdev_priv(master);
 415         slave = dlp->slave;
 416         flp = netdev_priv(slave);
 417
 418         err = (*flp->deassoc)(slave, master);
 419         if (!err) {
 420                 list_del(&dlp->list);
 421
 422                 unregister_netdevice(master);
 423
 424                 dev_put(slave);
 425         }
 426 out:
 427         rtnl_unlock();
 428         return err;
 429 }
 430
 431 static int dlci_ioctl(unsigned int cmd, void __user *arg)
 432 {
 433         struct dlci_add add;
 434         int err;
 435
 436         if (!capable(CAP_NET_ADMIN))
 437                 return -EPERM;
 438
 439         if (copy_from_user(&add, arg, sizeof(struct dlci_add)))
 440                 return -EFAULT;
 441
 442         switch (cmd)
 443         {
 444                 case SIOCADDDLCI:
 445                         err = dlci_add(&add);
 446
 447                         if (!err)
 448                                 if (copy_to_user(arg, &add, sizeof(struct dlci_add)))
 449                                         return -EFAULT;
 450                         break;
 451
 452                 case SIOCDELDLCI:
 453                         err = dlci_del(&add);
 454                         break;
 455
 456                 default:
 457                         err = -EINVAL;
 458         }
 459
 460         return err;
 461 }
 462
 463 static const struct header_ops dlci_header_ops = {
 464         .create = dlci_header,
 465 };
 466
 467 static const struct net_device_ops dlci_netdev_ops = {
 468         .ndo_open       = dlci_open,
 469         .ndo_stop       = dlci_close,
 470         .ndo_do_ioctl   = dlci_dev_ioctl,
 471         .ndo_start_xmit = dlci_transmit,
 472         .ndo_change_mtu = dlci_change_mtu,
 473 };
 474
 475 static void dlci_setup(struct net_device *dev)
 476 {
 477         struct dlci_local *dlp = netdev_priv(dev);
 478
 479         dev->flags              = 0;
 480         dev->header_ops         = &dlci_header_ops;
 481         dev->netdev_ops         = &dlci_netdev_ops;
 482         dev->destructor         = free_netdev;
 483
 484         dlp->receive            = dlci_receive;
 485
 486         dev->type               = ARPHRD_DLCI;
 487         dev->hard_header_len    = sizeof(struct frhdr);
 488         dev->addr_len           = sizeof(short);
 489
 490 }
 491
 492 /* if slave is unregistering, then cleanup master */
 493 static int dlci_dev_event(struct notifier_block *unused,
 494                           unsigned long event, void *ptr)
 495 {
 496         struct net_device *dev = (struct net_device *) ptr;
 497
 498         if (dev_net(dev) != &init_net)
 499                 return NOTIFY_DONE;
 500
 501         if (event == NETDEV_UNREGISTER) {
 502                 struct dlci_local *dlp;
 503
 504                 list_for_each_entry(dlp, &dlci_devs, list) {
 505                         if (dlp->slave == dev) {
 506                                 list_del(&dlp->list);
 507                                 unregister_netdevice(dlp->master);
 508                                 dev_put(dlp->slave);
 509                                 break;
 510                         }
 511                 }
 512         }
 513         return NOTIFY_DONE;
 514 }
 515
 516 static struct notifier_block dlci_notifier = {
 517         .notifier_call = dlci_dev_event,
 518 };
 519
 520 static int __init init_dlci(void)
 521 {
 522         dlci_ioctl_set(dlci_ioctl);
 523         register_netdevice_notifier(&dlci_notifier);
 524
 525         printk("%s.\n", version);
 526
 527         return 0;
 528 }
 529
 530 static void __exit dlci_exit(void)
 531 {
 532         struct dlci_local       *dlp, *nxt;
 533
 534         dlci_ioctl_set(NULL);
 535         unregister_netdevice_notifier(&dlci_notifier);
 536
 537         rtnl_lock();
 538         list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
 539                 unregister_netdevice(dlp->master);
 540                 dev_put(dlp->slave);
 541         }
 542         rtnl_unlock();
 543 }
 544
 545 module_init(init_dlci);
 546 module_exit(dlci_exit);
 547
 548 MODULE_AUTHOR("Mike McLagan");
 549 MODULE_DESCRIPTION("Frame Relay DLCI layer");
 550 MODULE_LICENSE("GPL");