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 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->netdev_ops->ndo_start_xmit(skb, dlp->slave);
 204         switch (ret)
 205         {
 206                 case DLCI_RET_OK:
 207                         dev->stats.tx_packets++;
 208                         ret = NETDEV_TX_OK;
 209                         break;
 210                         case DLCI_RET_ERR:
 211                         dev->stats.tx_errors++;
 212                         ret = NETDEV_TX_OK;
 213                         break;
 214                         case DLCI_RET_DROP:
 215                         dev->stats.tx_dropped++;
 216                         ret = NETDEV_TX_BUSY;
 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 = netdev_priv(dev);
 299
 300         return dev_set_mtu(dlp->slave, new_mtu);
 301 }
 302
 303 static int dlci_open(struct net_device *dev)
 304 {
 305         struct dlci_local       *dlp;
 306         struct frad_local       *flp;
 307         int                     err;
 308
 309         dlp = netdev_priv(dev);
 310
 311         if (!*(short *)(dev->dev_addr))
 312                 return(-EINVAL);
 313
 314         if (!netif_running(dlp->slave))
 315                 return(-ENOTCONN);
 316
 317         flp = netdev_priv(dlp->slave);
 318         err = (*flp->activate)(dlp->slave, dev);
 319         if (err)
 320                 return(err);
 321
 322         netif_start_queue(dev);
 323
 324         return 0;
 325 }
 326
 327 static int dlci_close(struct net_device *dev)
 328 {
 329         struct dlci_local       *dlp;
 330         struct frad_local       *flp;
 331         int                     err;
 332
 333         netif_stop_queue(dev);
 334
 335         dlp = netdev_priv(dev);
 336
 337         flp = netdev_priv(dlp->slave);
 338         err = (*flp->deactivate)(dlp->slave, dev);
 339
 340         return 0;
 341 }
 342
 343 static int dlci_add(struct dlci_add *dlci)
 344 {
 345         struct net_device       *master, *slave;
 346         struct dlci_local       *dlp;
 347         struct frad_local       *flp;
 348         int                     err = -EINVAL;
 349
 350
 351         /* validate slave device */
 352         slave = dev_get_by_name(&init_net, dlci->devname);
 353         if (!slave)
 354                 return -ENODEV;
 355
 356         if (slave->type != ARPHRD_FRAD || netdev_priv(slave) == NULL)
 357                 goto err1;
 358
 359         /* create device name */
 360         master = alloc_netdev( sizeof(struct dlci_local), "dlci%d",
 361                               dlci_setup);
 362         if (!master) {
 363                 err = -ENOMEM;
 364                 goto err1;
 365         }
 366
 367         /* make sure same slave not already registered */
 368         rtnl_lock();
 369         list_for_each_entry(dlp, &dlci_devs, list) {
 370                 if (dlp->slave == slave) {
 371                         err = -EBUSY;
 372                         goto err2;
 373                 }
 374         }
 375
 376         err = dev_alloc_name(master, master->name);
 377         if (err < 0)
 378                 goto err2;
 379
 380         *(short *)(master->dev_addr) = dlci->dlci;
 381
 382         dlp = netdev_priv(master);
 383         dlp->slave = slave;
 384         dlp->master = master;
 385
 386         flp = netdev_priv(slave);
 387         err = (*flp->assoc)(slave, master);
 388         if (err < 0)
 389                 goto err2;
 390
 391         err = register_netdevice(master);
 392         if (err < 0)
 393                 goto err2;
 394
 395         strcpy(dlci->devname, master->name);
 396
 397         list_add(&dlp->list, &dlci_devs);
 398         rtnl_unlock();
 399
 400         return(0);
 401
 402  err2:
 403         rtnl_unlock();
 404         free_netdev(master);
 405  err1:
 406         dev_put(slave);
 407         return(err);
 408 }
 409
 410 static int dlci_del(struct dlci_add *dlci)
 411 {
 412         struct dlci_local       *dlp;
 413         struct frad_local       *flp;
 414         struct net_device       *master, *slave;
 415         int                     err;
 416
 417         /* validate slave device */
 418         master = __dev_get_by_name(&init_net, dlci->devname);
 419         if (!master)
 420                 return(-ENODEV);
 421
 422         if (netif_running(master)) {
 423                 return(-EBUSY);
 424         }
 425
 426         dlp = netdev_priv(master);
 427         slave = dlp->slave;
 428         flp = netdev_priv(slave);
 429
 430         rtnl_lock();
 431         err = (*flp->deassoc)(slave, master);
 432         if (!err) {
 433                 list_del(&dlp->list);
 434
 435                 unregister_netdevice(master);
 436
 437                 dev_put(slave);
 438         }
 439         rtnl_unlock();
 440
 441         return(err);
 442 }
 443
 444 static int dlci_ioctl(unsigned int cmd, void __user *arg)
 445 {
 446         struct dlci_add add;
 447         int err;
 448
 449         if (!capable(CAP_NET_ADMIN))
 450                 return(-EPERM);
 451
 452         if(copy_from_user(&add, arg, sizeof(struct dlci_add)))
 453                 return -EFAULT;
 454
 455         switch (cmd)
 456         {
 457                 case SIOCADDDLCI:
 458                         err = dlci_add(&add);
 459
 460                         if (!err)
 461                                 if(copy_to_user(arg, &add, sizeof(struct dlci_add)))
 462                                         return -EFAULT;
 463                         break;
 464
 465                 case SIOCDELDLCI:
 466                         err = dlci_del(&add);
 467                         break;
 468
 469                 default:
 470                         err = -EINVAL;
 471         }
 472
 473         return(err);
 474 }
 475
 476 static const struct header_ops dlci_header_ops = {
 477         .create = dlci_header,
 478 };
 479
 480 static const struct net_device_ops dlci_netdev_ops = {
 481         .ndo_open       = dlci_open,
 482         .ndo_stop       = dlci_close,
 483         .ndo_do_ioctl   = dlci_dev_ioctl,
 484         .ndo_start_xmit = dlci_transmit,
 485         .ndo_change_mtu = dlci_change_mtu,
 486 };
 487
 488 static void dlci_setup(struct net_device *dev)
 489 {
 490         struct dlci_local *dlp = netdev_priv(dev);
 491
 492         dev->flags              = 0;
 493         dev->header_ops         = &dlci_header_ops;
 494         dev->netdev_ops         = &dlci_netdev_ops;
 495         dev->destructor         = free_netdev;
 496
 497         dlp->receive            = dlci_receive;
 498
 499         dev->type               = ARPHRD_DLCI;
 500         dev->hard_header_len    = sizeof(struct frhdr);
 501         dev->addr_len           = sizeof(short);
 502
 503 }
 504
 505 /* if slave is unregistering, then cleanup master */
 506 static int dlci_dev_event(struct notifier_block *unused,
 507                           unsigned long event, void *ptr)
 508 {
 509         struct net_device *dev = (struct net_device *) ptr;
 510
 511         if (dev_net(dev) != &init_net)
 512                 return NOTIFY_DONE;
 513
 514         if (event == NETDEV_UNREGISTER) {
 515                 struct dlci_local *dlp;
 516
 517                 list_for_each_entry(dlp, &dlci_devs, list) {
 518                         if (dlp->slave == dev) {
 519                                 list_del(&dlp->list);
 520                                 unregister_netdevice(dlp->master);
 521                                 dev_put(dlp->slave);
 522                                 break;
 523                         }
 524                 }
 525         }
 526         return NOTIFY_DONE;
 527 }
 528
 529 static struct notifier_block dlci_notifier = {
 530         .notifier_call = dlci_dev_event,
 531 };
 532
 533 static int __init init_dlci(void)
 534 {
 535         dlci_ioctl_set(dlci_ioctl);
 536         register_netdevice_notifier(&dlci_notifier);
 537
 538         printk("%s.\n", version);
 539
 540         return 0;
 541 }
 542
 543 static void __exit dlci_exit(void)
 544 {
 545         struct dlci_local       *dlp, *nxt;
 546
 547         dlci_ioctl_set(NULL);
 548         unregister_netdevice_notifier(&dlci_notifier);
 549
 550         rtnl_lock();
 551         list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
 552                 unregister_netdevice(dlp->master);
 553                 dev_put(dlp->slave);
 554         }
 555         rtnl_unlock();
 556 }
 557
 558 module_init(init_dlci);
 559 module_exit(dlci_exit);
 560
 561 MODULE_AUTHOR("Mike McLagan");
 562 MODULE_DESCRIPTION("Frame Relay DLCI layer");
 563 MODULE_LICENSE("GPL");