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         unsigned int            hlen;
  75         char                    *dest;
  76
  77         hdr.control = FRAD_I_UI;
  78         switch (type)
  79         {
  80                 case ETH_P_IP:
  81                         hdr.IP_NLPID = FRAD_P_IP;
  82                         hlen = sizeof(hdr.control) + sizeof(hdr.IP_NLPID);
  83                         break;
  84
  85                 /* feel free to add other types, if necessary */
  86
  87                 default:
  88                         hdr.pad = FRAD_P_PADDING;
  89                         hdr.NLPID = FRAD_P_SNAP;
  90                         memset(hdr.OUI, 0, sizeof(hdr.OUI));
  91                         hdr.PID = htons(type);
  92                         hlen = sizeof(hdr);
  93                         break;
  94         }
  95
  96         dest = skb_push(skb, hlen);
  97         if (!dest)
  98                 return 0;
  99
 100         memcpy(dest, &hdr, hlen);
 101
 102         return hlen;
 103 }
 104
 105 static void dlci_receive(struct sk_buff *skb, struct net_device *dev)
 106 {
 107         struct frhdr            *hdr;
 108         int                                     process, header;
 109
 110         if (!pskb_may_pull(skb, sizeof(*hdr))) {
 111                 netdev_notice(dev, "invalid data no header\n");
 112                 dev->stats.rx_errors++;
 113                 kfree_skb(skb);
 114                 return;
 115         }
 116
 117         hdr = (struct frhdr *) skb->data;
 118         process = 0;
 119         header = 0;
 120         skb->dev = dev;
 121
 122         if (hdr->control != FRAD_I_UI)
 123         {
 124                 netdev_notice(dev, "Invalid header flag 0x%02X\n",
 125                               hdr->control);
 126                 dev->stats.rx_errors++;
 127         }
 128         else
 129                 switch (hdr->IP_NLPID)
 130                 {
 131                         case FRAD_P_PADDING:
 132                                 if (hdr->NLPID != FRAD_P_SNAP)
 133                                 {
 134                                         netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
 135                                                       hdr->NLPID);
 136                                         dev->stats.rx_errors++;
 137                                         break;
 138                                 }
 139
 140                                 if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
 141                                 {
 142                                         netdev_notice(dev, "Unsupported organizationally unique identifier 0x%02X-%02X-%02X\n",
 143                                                       hdr->OUI[0],
 144                                                       hdr->OUI[1],
 145                                                       hdr->OUI[2]);
 146                                         dev->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                                 netdev_notice(dev, "Unsupported NLPID 0x%02X\n",
 167                                               hdr->pad);
 168                                 dev->stats.rx_errors++;
 169                                 break;
 170
 171                         default:
 172                                 netdev_notice(dev, "Invalid pad byte 0x%02X\n",
 173                                               hdr->pad);
 174                                 dev->stats.rx_errors++;
 175                                 break;
 176                 }
 177
 178         if (process)
 179         {
 180                 /* we've set up the protocol, so discard the header */
 181                 skb_reset_mac_header(skb);
 182                 skb_pull(skb, header);
 183                 dev->stats.rx_bytes += skb->len;
 184                 netif_rx(skb);
 185                 dev->stats.rx_packets++;
 186         }
 187         else
 188                 dev_kfree_skb(skb);
 189 }
 190
 191 static netdev_tx_t dlci_transmit(struct sk_buff *skb, struct net_device *dev)
 192 {
 193         struct dlci_local *dlp = netdev_priv(dev);
 194
 195         if (skb)
 196                 dlp->slave->netdev_ops->ndo_start_xmit(skb, dlp->slave);
 197         return NETDEV_TX_OK;
 198 }
 199
 200 static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
 201 {
 202         struct dlci_conf        config;
 203         struct dlci_local       *dlp;
 204         struct frad_local       *flp;
 205         int                     err;
 206
 207         dlp = netdev_priv(dev);
 208
 209         flp = netdev_priv(dlp->slave);
 210
 211         if (!get)
 212         {
 213                 if (copy_from_user(&config, conf, sizeof(struct dlci_conf)))
 214                         return -EFAULT;
 215                 if (config.flags & ~DLCI_VALID_FLAGS)
 216                         return -EINVAL;
 217                 memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
 218                 dlp->configured = 1;
 219         }
 220
 221         err = (*flp->dlci_conf)(dlp->slave, dev, get);
 222         if (err)
 223                 return err;
 224
 225         if (get)
 226         {
 227                 if (copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
 228                         return -EFAULT;
 229         }
 230
 231         return 0;
 232 }
 233
 234 static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 235 {
 236         struct dlci_local *dlp;
 237
 238         if (!capable(CAP_NET_ADMIN))
 239                 return -EPERM;
 240
 241         dlp = netdev_priv(dev);
 242
 243         switch (cmd)
 244         {
 245                 case DLCI_GET_SLAVE:
 246                         if (!*(short *)(dev->dev_addr))
 247                                 return -EINVAL;
 248
 249                         strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
 250                         break;
 251
 252                 case DLCI_GET_CONF:
 253                 case DLCI_SET_CONF:
 254                         if (!*(short *)(dev->dev_addr))
 255                                 return -EINVAL;
 256
 257                         return dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF);
 258
 259                 default:
 260                         return -EOPNOTSUPP;
 261         }
 262         return 0;
 263 }
 264
 265 static int dlci_change_mtu(struct net_device *dev, int new_mtu)
 266 {
 267         struct dlci_local *dlp = netdev_priv(dev);
 268
 269         return dev_set_mtu(dlp->slave, new_mtu);
 270 }
 271
 272 static int dlci_open(struct net_device *dev)
 273 {
 274         struct dlci_local       *dlp;
 275         struct frad_local       *flp;
 276         int                     err;
 277
 278         dlp = netdev_priv(dev);
 279
 280         if (!*(short *)(dev->dev_addr))
 281                 return -EINVAL;
 282
 283         if (!netif_running(dlp->slave))
 284                 return -ENOTCONN;
 285
 286         flp = netdev_priv(dlp->slave);
 287         err = (*flp->activate)(dlp->slave, dev);
 288         if (err)
 289                 return err;
 290
 291         netif_start_queue(dev);
 292
 293         return 0;
 294 }
 295
 296 static int dlci_close(struct net_device *dev)
 297 {
 298         struct dlci_local       *dlp;
 299         struct frad_local       *flp;
 300         int                     err;
 301
 302         netif_stop_queue(dev);
 303
 304         dlp = netdev_priv(dev);
 305
 306         flp = netdev_priv(dlp->slave);
 307         err = (*flp->deactivate)(dlp->slave, dev);
 308
 309         return 0;
 310 }
 311
 312 static int dlci_add(struct dlci_add *dlci)
 313 {
 314         struct net_device       *master, *slave;
 315         struct dlci_local       *dlp;
 316         struct frad_local       *flp;
 317         int                     err = -EINVAL;
 318
 319
 320         /* validate slave device */
 321         slave = dev_get_by_name(&init_net, dlci->devname);
 322         if (!slave)
 323                 return -ENODEV;
 324
 325         if (slave->type != ARPHRD_FRAD || netdev_priv(slave) == NULL)
 326                 goto err1;
 327
 328         /* create device name */
 329         master = alloc_netdev(sizeof(struct dlci_local), "dlci%d",
 330                               NET_NAME_UNKNOWN, dlci_setup);
 331         if (!master) {
 332                 err = -ENOMEM;
 333                 goto err1;
 334         }
 335
 336         /* make sure same slave not already registered */
 337         rtnl_lock();
 338         list_for_each_entry(dlp, &dlci_devs, list) {
 339                 if (dlp->slave == slave) {
 340                         err = -EBUSY;
 341                         goto err2;
 342                 }
 343         }
 344
 345         *(short *)(master->dev_addr) = dlci->dlci;
 346
 347         dlp = netdev_priv(master);
 348         dlp->slave = slave;
 349         dlp->master = master;
 350
 351         flp = netdev_priv(slave);
 352         err = (*flp->assoc)(slave, master);
 353         if (err < 0)
 354                 goto err2;
 355
 356         err = register_netdevice(master);
 357         if (err < 0)
 358                 goto err2;
 359
 360         strcpy(dlci->devname, master->name);
 361
 362         list_add(&dlp->list, &dlci_devs);
 363         rtnl_unlock();
 364
 365         return 0;
 366
 367  err2:
 368         rtnl_unlock();
 369         free_netdev(master);
 370  err1:
 371         dev_put(slave);
 372         return err;
 373 }
 374
 375 static int dlci_del(struct dlci_add *dlci)
 376 {
 377         struct dlci_local       *dlp;
 378         struct frad_local       *flp;
 379         struct net_device       *master, *slave;
 380         int                     err;
 381         bool                    found = false;
 382
 383         rtnl_lock();
 384
 385         /* validate slave device */
 386         master = __dev_get_by_name(&init_net, dlci->devname);
 387         if (!master) {
 388                 err = -ENODEV;
 389                 goto out;
 390         }
 391
 392         list_for_each_entry(dlp, &dlci_devs, list) {
 393                 if (dlp->master == master) {
 394                         found = true;
 395                         break;
 396                 }
 397         }
 398         if (!found) {
 399                 err = -ENODEV;
 400                 goto out;
 401         }
 402
 403         if (netif_running(master)) {
 404                 err = -EBUSY;
 405                 goto out;
 406         }
 407
 408         dlp = netdev_priv(master);
 409         slave = dlp->slave;
 410         flp = netdev_priv(slave);
 411
 412         err = (*flp->deassoc)(slave, master);
 413         if (!err) {
 414                 list_del(&dlp->list);
 415
 416                 unregister_netdevice(master);
 417
 418                 dev_put(slave);
 419         }
 420 out:
 421         rtnl_unlock();
 422         return err;
 423 }
 424
 425 static int dlci_ioctl(unsigned int cmd, void __user *arg)
 426 {
 427         struct dlci_add add;
 428         int err;
 429
 430         if (!capable(CAP_NET_ADMIN))
 431                 return -EPERM;
 432
 433         if (copy_from_user(&add, arg, sizeof(struct dlci_add)))
 434                 return -EFAULT;
 435
 436         switch (cmd)
 437         {
 438                 case SIOCADDDLCI:
 439                         err = dlci_add(&add);
 440
 441                         if (!err)
 442                                 if (copy_to_user(arg, &add, sizeof(struct dlci_add)))
 443                                         return -EFAULT;
 444                         break;
 445
 446                 case SIOCDELDLCI:
 447                         err = dlci_del(&add);
 448                         break;
 449
 450                 default:
 451                         err = -EINVAL;
 452         }
 453
 454         return err;
 455 }
 456
 457 static const struct header_ops dlci_header_ops = {
 458         .create = dlci_header,
 459 };
 460
 461 static const struct net_device_ops dlci_netdev_ops = {
 462         .ndo_open       = dlci_open,
 463         .ndo_stop       = dlci_close,
 464         .ndo_do_ioctl   = dlci_dev_ioctl,
 465         .ndo_start_xmit = dlci_transmit,
 466         .ndo_change_mtu = dlci_change_mtu,
 467 };
 468
 469 static void dlci_setup(struct net_device *dev)
 470 {
 471         struct dlci_local *dlp = netdev_priv(dev);
 472
 473         dev->flags              = 0;
 474         dev->header_ops         = &dlci_header_ops;
 475         dev->netdev_ops         = &dlci_netdev_ops;
 476         dev->destructor         = free_netdev;
 477
 478         dlp->receive            = dlci_receive;
 479
 480         dev->type               = ARPHRD_DLCI;
 481         dev->hard_header_len    = sizeof(struct frhdr);
 482         dev->addr_len           = sizeof(short);
 483
 484 }
 485
 486 /* if slave is unregistering, then cleanup master */
 487 static int dlci_dev_event(struct notifier_block *unused,
 488                           unsigned long event, void *ptr)
 489 {
 490         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 491
 492         if (dev_net(dev) != &init_net)
 493                 return NOTIFY_DONE;
 494
 495         if (event == NETDEV_UNREGISTER) {
 496                 struct dlci_local *dlp;
 497
 498                 list_for_each_entry(dlp, &dlci_devs, list) {
 499                         if (dlp->slave == dev) {
 500                                 list_del(&dlp->list);
 501                                 unregister_netdevice(dlp->master);
 502                                 dev_put(dlp->slave);
 503                                 break;
 504                         }
 505                 }
 506         }
 507         return NOTIFY_DONE;
 508 }
 509
 510 static struct notifier_block dlci_notifier = {
 511         .notifier_call = dlci_dev_event,
 512 };
 513
 514 static int __init init_dlci(void)
 515 {
 516         dlci_ioctl_set(dlci_ioctl);
 517         register_netdevice_notifier(&dlci_notifier);
 518
 519         printk("%s.\n", version);
 520
 521         return 0;
 522 }
 523
 524 static void __exit dlci_exit(void)
 525 {
 526         struct dlci_local       *dlp, *nxt;
 527
 528         dlci_ioctl_set(NULL);
 529         unregister_netdevice_notifier(&dlci_notifier);
 530
 531         rtnl_lock();
 532         list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
 533                 unregister_netdevice(dlp->master);
 534                 dev_put(dlp->slave);
 535         }
 536         rtnl_unlock();
 537 }
 538
 539 module_init(init_dlci);
 540 module_exit(dlci_exit);
 541
 542 MODULE_AUTHOR("Mike McLagan");
 543 MODULE_DESCRIPTION("Frame Relay DLCI layer");
 544 MODULE_LICENSE("GPL");