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