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/config.h> /* for CONFIG_DLCI_COUNT */
  32 #include <linux/module.h>
  33 #include <linux/kernel.h>
  34 #include <linux/types.h>
  35 #include <linux/fcntl.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/ptrace.h>
  38 #include <linux/ioport.h>
  39 #include <linux/in.h>
  40 #include <linux/init.h>
  41 #include <linux/slab.h>
  42 #include <linux/string.h>
  43 #include <linux/errno.h>
  44 #include <linux/netdevice.h>
  45 #include <linux/skbuff.h>
  46 #include <linux/if_arp.h>
  47 #include <linux/if_frad.h>
  48
  49 #include <net/sock.h>
  50
  51 #include <asm/system.h>
  52 #include <asm/bitops.h>
  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, void *daddr, void *saddr,
  71                            unsigned len)
  72 {
  73         struct frhdr            hdr;
  74         struct dlci_local       *dlp;
  75         unsigned int            hlen;
  76         char                    *dest;
  77
  78         dlp = dev->priv;
  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 = dev->priv;
 115         if (!pskb_may_pull(skb, sizeof(*hdr))) {
 116                 printk(KERN_NOTICE "%s: invalid data no header\n",
 117                        dev->name);
 118                 dlp->stats.rx_errors++;
 119                 kfree_skb(skb);
 120                 return;
 121         }
 122
 123         hdr = (struct frhdr *) skb->data;
 124         process = 0;
 125         header = 0;
 126         skb->dev = dev;
 127
 128         if (hdr->control != FRAD_I_UI)
 129         {
 130                 printk(KERN_NOTICE "%s: Invalid header flag 0x%02X.\n", dev->name, hdr->control);
 131                 dlp->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                                         printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->NLPID);
 140                                         dlp->stats.rx_errors++;
 141                                         break;
 142                                 }
 143
 144                                 if (hdr->OUI[0] + hdr->OUI[1] + hdr->OUI[2] != 0)
 145                                 {
 146                                         printk(KERN_NOTICE "%s: Unsupported organizationally unique identifier 0x%02X-%02X-%02X.\n", dev->name, hdr->OUI[0], hdr->OUI[1], hdr->OUI[2]);
 147                                         dlp->stats.rx_errors++;
 148                                         break;
 149                                 }
 150
 151                                 /* at this point, it's an EtherType frame */
 152                                 header = sizeof(struct frhdr);
 153                                 /* Already in network order ! */
 154                                 skb->protocol = hdr->PID;
 155                                 process = 1;
 156                                 break;
 157
 158                         case FRAD_P_IP:
 159                                 header = sizeof(hdr->control) + sizeof(hdr->IP_NLPID);
 160                                 skb->protocol = htons(ETH_P_IP);
 161                                 process = 1;
 162                                 break;
 163
 164                         case FRAD_P_SNAP:
 165                         case FRAD_P_Q933:
 166                         case FRAD_P_CLNP:
 167                                 printk(KERN_NOTICE "%s: Unsupported NLPID 0x%02X.\n", dev->name, hdr->pad);
 168                                 dlp->stats.rx_errors++;
 169                                 break;
 170
 171                         default:
 172                                 printk(KERN_NOTICE "%s: Invalid pad byte 0x%02X.\n", dev->name, hdr->pad);
 173                                 dlp->stats.rx_errors++;
 174                                 break;
 175                 }
 176
 177         if (process)
 178         {
 179                 /* we've set up the protocol, so discard the header */
 180                 skb->mac.raw = skb->data;
 181                 skb_pull(skb, header);
 182                 dlp->stats.rx_bytes += skb->len;
 183                 netif_rx(skb);
 184                 dlp->stats.rx_packets++;
 185                 dev->last_rx = jiffies;
 186         }
 187         else
 188                 dev_kfree_skb(skb);
 189 }
 190
 191 static int dlci_transmit(struct sk_buff *skb, struct net_device *dev)
 192 {
 193         struct dlci_local *dlp;
 194         int                                     ret;
 195
 196         ret = 0;
 197
 198         if (!skb || !dev)
 199                 return(0);
 200
 201         dlp = dev->priv;
 202
 203         netif_stop_queue(dev);
 204
 205         ret = dlp->slave->hard_start_xmit(skb, dlp->slave);
 206         switch (ret)
 207         {
 208                 case DLCI_RET_OK:
 209                         dlp->stats.tx_packets++;
 210                         ret = 0;
 211                         break;
 212                         case DLCI_RET_ERR:
 213                         dlp->stats.tx_errors++;
 214                         ret = 0;
 215                         break;
 216                         case DLCI_RET_DROP:
 217                         dlp->stats.tx_dropped++;
 218                         ret = 1;
 219                         break;
 220         }
 221         /* Alan Cox recommends always returning 0, and always freeing the packet */
 222         /* experience suggest a slightly more conservative approach */
 223
 224         if (!ret)
 225         {
 226                 dev_kfree_skb(skb);
 227                 netif_wake_queue(dev);
 228         }
 229         return(ret);
 230 }
 231
 232 static int dlci_config(struct net_device *dev, struct dlci_conf __user *conf, int get)
 233 {
 234         struct dlci_conf        config;
 235         struct dlci_local       *dlp;
 236         struct frad_local       *flp;
 237         int                     err;
 238
 239         dlp = dev->priv;
 240
 241         flp = dlp->slave->priv;
 242
 243         if (!get)
 244         {
 245                 if(copy_from_user(&config, conf, sizeof(struct dlci_conf)))
 246                         return -EFAULT;
 247                 if (config.flags & ~DLCI_VALID_FLAGS)
 248                         return(-EINVAL);
 249                 memcpy(&dlp->config, &config, sizeof(struct dlci_conf));
 250                 dlp->configured = 1;
 251         }
 252
 253         err = (*flp->dlci_conf)(dlp->slave, dev, get);
 254         if (err)
 255                 return(err);
 256
 257         if (get)
 258         {
 259                 if(copy_to_user(conf, &dlp->config, sizeof(struct dlci_conf)))
 260                         return -EFAULT;
 261         }
 262
 263         return(0);
 264 }
 265
 266 static int dlci_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 267 {
 268         struct dlci_local *dlp;
 269
 270         if (!capable(CAP_NET_ADMIN))
 271                 return(-EPERM);
 272
 273         dlp = dev->priv;
 274
 275         switch(cmd)
 276         {
 277                 case DLCI_GET_SLAVE:
 278                         if (!*(short *)(dev->dev_addr))
 279                                 return(-EINVAL);
 280
 281                         strncpy(ifr->ifr_slave, dlp->slave->name, sizeof(ifr->ifr_slave));
 282                         break;
 283
 284                 case DLCI_GET_CONF:
 285                 case DLCI_SET_CONF:
 286                         if (!*(short *)(dev->dev_addr))
 287                                 return(-EINVAL);
 288
 289                         return(dlci_config(dev, ifr->ifr_data, cmd == DLCI_GET_CONF));
 290                         break;
 291
 292                 default:
 293                         return(-EOPNOTSUPP);
 294         }
 295         return(0);
 296 }
 297
 298 static int dlci_change_mtu(struct net_device *dev, int new_mtu)
 299 {
 300         struct dlci_local *dlp;
 301
 302         dlp = dev->priv;
 303
 304         return((*dlp->slave->change_mtu)(dlp->slave, new_mtu));
 305 }
 306
 307 static int dlci_open(struct net_device *dev)
 308 {
 309         struct dlci_local       *dlp;
 310         struct frad_local       *flp;
 311         int                     err;
 312
 313         dlp = dev->priv;
 314
 315         if (!*(short *)(dev->dev_addr))
 316                 return(-EINVAL);
 317
 318         if (!netif_running(dlp->slave))
 319                 return(-ENOTCONN);
 320
 321         flp = dlp->slave->priv;
 322         err = (*flp->activate)(dlp->slave, dev);
 323         if (err)
 324                 return(err);
 325
 326         netif_start_queue(dev);
 327
 328         return 0;
 329 }
 330
 331 static int dlci_close(struct net_device *dev)
 332 {
 333         struct dlci_local       *dlp;
 334         struct frad_local       *flp;
 335         int                     err;
 336
 337         netif_stop_queue(dev);
 338
 339         dlp = dev->priv;
 340
 341         flp = dlp->slave->priv;
 342         err = (*flp->deactivate)(dlp->slave, dev);
 343
 344         return 0;
 345 }
 346
 347 static struct net_device_stats *dlci_get_stats(struct net_device *dev)
 348 {
 349         struct dlci_local *dlp;
 350
 351         dlp = dev->priv;
 352
 353         return(&dlp->stats);
 354 }
 355
 356 static int dlci_add(struct dlci_add *dlci)
 357 {
 358         struct net_device       *master, *slave;
 359         struct dlci_local       *dlp;
 360         struct frad_local       *flp;
 361         int                     err = -EINVAL;
 362
 363
 364         /* validate slave device */
 365         slave = dev_get_by_name(dlci->devname);
 366         if (!slave)
 367                 return -ENODEV;
 368
 369         if (slave->type != ARPHRD_FRAD || slave->priv == NULL)
 370                 goto err1;
 371
 372         /* create device name */
 373         master = alloc_netdev( sizeof(struct dlci_local), "dlci%d",
 374                               dlci_setup);
 375         if (!master) {
 376                 err = -ENOMEM;
 377                 goto err1;
 378         }
 379
 380         /* make sure same slave not already registered */
 381         rtnl_lock();
 382         list_for_each_entry(dlp, &dlci_devs, list) {
 383                 if (dlp->slave == slave) {
 384                         err = -EBUSY;
 385                         goto err2;
 386                 }
 387         }
 388
 389         err = dev_alloc_name(master, master->name);
 390         if (err < 0)
 391                 goto err2;
 392
 393         *(short *)(master->dev_addr) = dlci->dlci;
 394
 395         dlp = (struct dlci_local *) master->priv;
 396         dlp->slave = slave;
 397         dlp->master = master;
 398
 399         flp = slave->priv;
 400         err = (*flp->assoc)(slave, master);
 401         if (err < 0)
 402                 goto err2;
 403
 404         err = register_netdevice(master);
 405         if (err < 0)
 406                 goto err2;
 407
 408         strcpy(dlci->devname, master->name);
 409
 410         list_add(&dlp->list, &dlci_devs);
 411         rtnl_unlock();
 412
 413         return(0);
 414
 415  err2:
 416         rtnl_unlock();
 417         free_netdev(master);
 418  err1:
 419         dev_put(slave);
 420         return(err);
 421 }
 422
 423 static int dlci_del(struct dlci_add *dlci)
 424 {
 425         struct dlci_local       *dlp;
 426         struct frad_local       *flp;
 427         struct net_device       *master, *slave;
 428         int                     err;
 429
 430         /* validate slave device */
 431         master = __dev_get_by_name(dlci->devname);
 432         if (!master)
 433                 return(-ENODEV);
 434
 435         if (netif_running(master)) {
 436                 return(-EBUSY);
 437         }
 438
 439         dlp = master->priv;
 440         slave = dlp->slave;
 441         flp = slave->priv;
 442
 443         rtnl_lock();
 444         err = (*flp->deassoc)(slave, master);
 445         if (!err) {
 446                 list_del(&dlp->list);
 447
 448                 unregister_netdevice(master);
 449
 450                 dev_put(slave);
 451         }
 452         rtnl_unlock();
 453
 454         return(err);
 455 }
 456
 457 static int dlci_ioctl(unsigned int cmd, void __user *arg)
 458 {
 459         struct dlci_add add;
 460         int err;
 461
 462         if (!capable(CAP_NET_ADMIN))
 463                 return(-EPERM);
 464
 465         if(copy_from_user(&add, arg, sizeof(struct dlci_add)))
 466                 return -EFAULT;
 467
 468         switch (cmd)
 469         {
 470                 case SIOCADDDLCI:
 471                         err = dlci_add(&add);
 472
 473                         if (!err)
 474                                 if(copy_to_user(arg, &add, sizeof(struct dlci_add)))
 475                                         return -EFAULT;
 476                         break;
 477
 478                 case SIOCDELDLCI:
 479                         err = dlci_del(&add);
 480                         break;
 481
 482                 default:
 483                         err = -EINVAL;
 484         }
 485
 486         return(err);
 487 }
 488
 489 static void dlci_setup(struct net_device *dev)
 490 {
 491         struct dlci_local *dlp = dev->priv;
 492
 493         dev->flags              = 0;
 494         dev->open               = dlci_open;
 495         dev->stop               = dlci_close;
 496         dev->do_ioctl           = dlci_dev_ioctl;
 497         dev->hard_start_xmit    = dlci_transmit;
 498         dev->hard_header        = dlci_header;
 499         dev->get_stats          = dlci_get_stats;
 500         dev->change_mtu         = dlci_change_mtu;
 501         dev->destructor         = free_netdev;
 502
 503         dlp->receive            = dlci_receive;
 504
 505         dev->type               = ARPHRD_DLCI;
 506         dev->hard_header_len    = sizeof(struct frhdr);
 507         dev->addr_len           = sizeof(short);
 508
 509 }
 510
 511 /* if slave is unregistering, then cleanup master */
 512 static int dlci_dev_event(struct notifier_block *unused,
 513                           unsigned long event, void *ptr)
 514 {
 515         struct net_device *dev = (struct net_device *) ptr;
 516
 517         if (event == NETDEV_UNREGISTER) {
 518                 struct dlci_local *dlp;
 519
 520                 list_for_each_entry(dlp, &dlci_devs, list) {
 521                         if (dlp->slave == dev) {
 522                                 list_del(&dlp->list);
 523                                 unregister_netdevice(dlp->master);
 524                                 dev_put(dlp->slave);
 525                                 break;
 526                         }
 527                 }
 528         }
 529         return NOTIFY_DONE;
 530 }
 531
 532 static struct notifier_block dlci_notifier = {
 533         .notifier_call = dlci_dev_event,
 534 };
 535
 536 static int __init init_dlci(void)
 537 {
 538         dlci_ioctl_set(dlci_ioctl);
 539         register_netdevice_notifier(&dlci_notifier);
 540
 541         printk("%s.\n", version);
 542
 543         return 0;
 544 }
 545
 546 static void __exit dlci_exit(void)
 547 {
 548         struct dlci_local       *dlp, *nxt;
 549
 550         dlci_ioctl_set(NULL);
 551         unregister_netdevice_notifier(&dlci_notifier);
 552
 553         rtnl_lock();
 554         list_for_each_entry_safe(dlp, nxt, &dlci_devs, list) {
 555                 unregister_netdevice(dlp->master);
 556                 dev_put(dlp->slave);
 557         }
 558         rtnl_unlock();
 559 }
 560
 561 module_init(init_dlci);
 562 module_exit(dlci_exit);
 563
 564 MODULE_AUTHOR("Mike McLagan");
 565 MODULE_DESCRIPTION("Frame Relay DLCI layer");
 566 MODULE_LICENSE("GPL");