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                 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                 printk(KERN_NOTICE "%s: Invalid header flag 0x%02X.\n", dev->name, hdr->control);
 130                 dev->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                                         dev->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                                         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                                 printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->pad);
 167                                 dev->stats.rx_errors++;
 168                                 break;
 169
 170                         default:
 171                                 printk(KERN_NOTICE "%s: Invalid pad byte 0x%02X.\n", dev->name, hdr->pad);
 172                                 dev->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                 dev->stats.rx_bytes += skb->len;
 182                 netif_rx(skb);
 183                 dev->stats.rx_packets++;
 184         }
 185         else
 186                 dev_kfree_skb(skb);
 187 }
 188
 189 static netdev_tx_t dlci_transmit(struct sk_buff *skb, struct net_device *dev)
 190 {
 191         struct dlci_local *dlp = netdev_priv(dev);
 192
 193         if (skb)
 194                 dlp->slave->netdev_ops->ndo_start_xmit(skb, dlp->slave);
 195         return NETDEV_TX_OK;
 196 }
 197
 198 static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
 199 {
 200         struct dlci_conf        config;
 201         struct dlci_local       *dlp;
 202         struct frad_local       *flp;
 203         int                     err;
 204
 205         dlp = netdev_priv(dev);
 206
 207         flp = netdev_priv(dlp->slave);
 208
 209         if (!get)
 210         {
 211                 if (copy_from_user(&config, conf, sizeof(struct dlci_conf)))
 212                         return -EFAULT;
 213                 if (config.flags & ~DLCI_VALID_FLAGS)
 214                         return -EINVAL;
 215                 memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
 216                 dlp->configured = 1;
 217         }
 218
 219         err = (*flp->dlci_conf)(dlp->slave, dev, get);
 220         if (err)
 221                 return err;
 222
 223         if (get)
 224         {
 225                 if (copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
 226                         return -EFAULT;
 227         }
 228
 229         return 0;
 230 }
 231
 232 static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 233 {
 234         struct dlci_local *dlp;
 235
 236         if (!capable(CAP_NET_ADMIN))
 237                 return -EPERM;
 238
 239         dlp = netdev_priv(dev);
 240
 241         switch (cmd)
 242         {
 243                 case DLCI_GET_SLAVE:
 244                         if (!*(short *)(dev->dev_addr))
 245                                 return -EINVAL;
 246
 247                         strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
 248                         break;
 249
 250                 case DLCI_GET_CONF:
 251                 case DLCI_SET_CONF:
 252                         if (!*(short *)(dev->dev_addr))
 253                                 return -EINVAL;
 254
 255                         return dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF);
 256                         break;
 257
 258                 default:
 259                         return -EOPNOTSUPP;
 260         }
 261         return 0;
 262 }
 263
 264 static int dlci_change_mtu(struct net_device *dev, int new_mtu)
 265 {
 266         struct dlci_local *dlp = netdev_priv(dev);
 267
 268         return dev_set_mtu(dlp->slave, new_mtu);
 269 }
 270
 271 static int dlci_open(struct net_device *dev)
 272 {
 273         struct dlci_local       *dlp;
 274         struct frad_local       *flp;
 275         int                     err;
 276
 277         dlp = netdev_priv(dev);
 278
 279         if (!*(short *)(dev->dev_addr))
 280                 return -EINVAL;
 281
 282         if (!netif_running(dlp->slave))
 283                 return -ENOTCONN;
 284
 285         flp = netdev_priv(dlp->slave);
 286         err = (*flp->activate)(dlp->slave, dev);
 287         if (err)
 288                 return err;
 289
 290         netif_start_queue(dev);
 291
 292         return 0;
 293 }
 294
 295 static int dlci_close(struct net_device *dev)
 296 {
 297         struct dlci_local       *dlp;
 298         struct frad_local       *flp;
 299         int                     err;
 300
 301         netif_stop_queue(dev);
 302
 303         dlp = netdev_priv(dev);
 304
 305         flp = netdev_priv(dlp->slave);
 306         err = (*flp->deactivate)(dlp->slave, dev);
 307
 308         return 0;
 309 }
 310
 311 static int dlci_add(struct dlci_add *dlci)
 312 {
 313         struct net_device       *master, *slave;
 314         struct dlci_local       *dlp;
 315         struct frad_local       *flp;
 316         int                     err = -EINVAL;
 317
 318
 319         /* validate slave device */
 320         slave = dev_get_by_name(&init_net, dlci->devname);
 321         if (!slave)
 322                 return -ENODEV;
 323
 324         if (slave->type != ARPHRD_FRAD || netdev_priv(slave) == NULL)
 325                 goto err1;
 326
 327         /* create device name */
 328         master = alloc_netdev( sizeof(struct dlci_local), "dlci%d",
 329                               dlci_setup);
 330         if (!master) {
 331                 err = -ENOMEM;
 332                 goto err1;
 333         }
 334
 335         /* make sure same slave not already registered */
 336         rtnl_lock();
 337         list_for_each_entry(dlp, &dlci_devs, list) {
 338                 if (dlp->slave == slave) {
 339                         err = -EBUSY;
 340                         goto err2;
 341                 }
 342         }
 343
 344         *(short *)(master->dev_addr) = dlci->dlci;
 345
 346         dlp = netdev_priv(master);
 347         dlp->slave = slave;
 348         dlp->master = master;
 349
 350         flp = netdev_priv(slave);
 351         err = (*flp->assoc)(slave, master);
 352         if (err < 0)
 353                 goto err2;
 354
 355         err = register_netdevice(master);
 356         if (err < 0)
 357                 goto err2;
 358
 359         strcpy(dlci->devname, master->name);
 360
 361         list_add(&dlp->list, &dlci_devs);
 362         rtnl_unlock();
 363
 364         return 0;
 365
 366  err2:
 367         rtnl_unlock();
 368         free_netdev(master);
 369  err1:
 370         dev_put(slave);
 371         return err;
 372 }
 373
 374 static int dlci_del(struct dlci_add *dlci)
 375 {
 376         struct dlci_local       *dlp;
 377         struct frad_local       *flp;
 378         struct net_device       *master, *slave;
 379         int                     err;
 380
 381         /* validate slave device */
 382         master = __dev_get_by_name(&init_net, dlci->devname);
 383         if (!master)
 384                 return -ENODEV;
 385
 386         if (netif_running(master)) {
 387                 return -EBUSY;
 388         }
 389
 390         dlp = netdev_priv(master);
 391         slave = dlp->slave;
 392         flp = netdev_priv(slave);
 393
 394         rtnl_lock();
 395         err = (*flp->deassoc)(slave, master);
 396         if (!err) {
 397                 list_del(&dlp->list);
 398
 399                 unregister_netdevice(master);
 400
 401                 dev_put(slave);
 402         }
 403         rtnl_unlock();
 404
 405         return err;
 406 }
 407
 408 static int dlci_ioctl(unsigned int cmd, void __user *arg)
 409 {
 410         struct dlci_add add;
 411         int err;
 412
 413         if (!capable(CAP_NET_ADMIN))
 414                 return -EPERM;
 415
 416         if (copy_from_user(&add, arg, sizeof(struct dlci_add)))
 417                 return -EFAULT;
 418
 419         switch (cmd)
 420         {
 421                 case SIOCADDDLCI:
 422                         err = dlci_add(&add);
 423
 424                         if (!err)
 425                                 if (copy_to_user(arg, &add, sizeof(struct dlci_add)))
 426                                         return -EFAULT;
 427                         break;
 428
 429                 case SIOCDELDLCI:
 430                         err = dlci_del(&add);
 431                         break;
 432
 433                 default:
 434                         err = -EINVAL;
 435         }
 436
 437         return err;
 438 }
 439
 440 static const struct header_ops dlci_header_ops = {
 441         .create = dlci_header,
 442 };
 443
 444 static const struct net_device_ops dlci_netdev_ops = {
 445         .ndo_open       = dlci_open,
 446         .ndo_stop       = dlci_close,
 447         .ndo_do_ioctl   = dlci_dev_ioctl,
 448         .ndo_start_xmit = dlci_transmit,
 449         .ndo_change_mtu = dlci_change_mtu,
 450 };
 451
 452 static void dlci_setup(struct net_device *dev)
 453 {
 454         struct dlci_local *dlp = netdev_priv(dev);
 455
 456         dev->flags              = 0;
 457         dev->header_ops         = &dlci_header_ops;
 458         dev->netdev_ops         = &dlci_netdev_ops;
 459         dev->destructor         = free_netdev;
 460
 461         dlp->receive            = dlci_receive;
 462
 463         dev->type               = ARPHRD_DLCI;
 464         dev->hard_header_len    = sizeof(struct frhdr);
 465         dev->addr_len           = sizeof(short);
 466
 467 }
 468
 469 /* if slave is unregistering, then cleanup master */
 470 static int dlci_dev_event(struct notifier_block *unused,
 471                           unsigned long event, void *ptr)
 472 {
 473         struct net_device *dev = (struct net_device *) ptr;
 474
 475         if (dev_net(dev) != &init_net)
 476                 return NOTIFY_DONE;
 477
 478         if (event == NETDEV_UNREGISTER) {
 479                 struct dlci_local *dlp;
 480
 481                 list_for_each_entry(dlp, &dlci_devs, list) {
 482                         if (dlp->slave == dev) {
 483                                 list_del(&dlp->list);
 484                                 unregister_netdevice(dlp->master);
 485                                 dev_put(dlp->slave);
 486                                 break;
 487                         }
 488                 }
 489         }
 490         return NOTIFY_DONE;
 491 }
 492
 493 static struct notifier_block dlci_notifier = {
 494         .notifier_call = dlci_dev_event,
 495 };
 496
 497 static int __init init_dlci(void)
 498 {
 499         dlci_ioctl_set(dlci_ioctl);
 500         register_netdevice_notifier(&dlci_notifier);
 501
 502         printk("%s.\n", version);
 503
 504         return 0;
 505 }
 506
 507 static void __exit dlci_exit(void)
 508 {
 509         struct dlci_local       *dlp, *nxt;
 510
 511         dlci_ioctl_set(NULL);
 512         unregister_netdevice_notifier(&dlci_notifier);
 513
 514         rtnl_lock();
 515         list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
 516                 unregister_netdevice(dlp->master);
 517                 dev_put(dlp->slave);
 518         }
 519         rtnl_unlock();
 520 }
 521
 522 module_init(init_dlci);
 523 module_exit(dlci_exit);
 524
 525 MODULE_AUTHOR("Mike McLagan");
 526 MODULE_DESCRIPTION("Frame Relay DLCI layer");
 527 MODULE_LICENSE("GPL");