net/wanrouter/wanmain.c

   1 /*****************************************************************************
   2 * wanmain.c     WAN Multiprotocol Router Module. Main code.
   3 *
   4 *               This module is completely hardware-independent and provides
   5 *               the following common services for the WAN Link Drivers:
   6 *                o WAN device management (registering, unregistering)
   7 *                o Network interface management
   8 *                o Physical connection management (dial-up, incoming calls)
   9 *                o Logical connection management (switched virtual circuits)
  10 *                o Protocol encapsulation/decapsulation
  11 *
  12 * Author:       Gideon Hack
  13 *
  14 * Copyright:    (c) 1995-1999 Sangoma Technologies Inc.
  15 *
  16 *               This program is free software; you can redistribute it and/or
  17 *               modify it under the terms of the GNU General Public License
  18 *               as published by the Free Software Foundation; either version
  19 *               2 of the License, or (at your option) any later version.
  20 * ============================================================================
  21 * Nov 24, 2000  Nenad Corbic    Updated for 2.4.X kernels
  22 * Nov 07, 2000  Nenad Corbic    Fixed the Mulit-Port PPP for kernels 2.2.16 and
  23 *                               greater.
  24 * Aug 2,  2000  Nenad Corbic    Block the Multi-Port PPP from running on
  25 *                               kernels 2.2.16 or greater.  The SyncPPP
  26 *                               has changed.
  27 * Jul 13, 2000  Nenad Corbic    Added SyncPPP support
  28 *                               Added extra debugging in device_setup().
  29 * Oct 01, 1999  Gideon Hack     Update for s514 PCI card
  30 * Dec 27, 1996  Gene Kozin      Initial version (based on Sangoma's WANPIPE)
  31 * Jan 16, 1997  Gene Kozin      router_devlist made public
  32 * Jan 31, 1997  Alan Cox        Hacked it about a bit for 2.1
  33 * Jun 27, 1997  Alan Cox        realigned with vendor code
  34 * Oct 15, 1997  Farhan Thawar   changed wan_encapsulate to add a pad byte of 0
  35 * Apr 20, 1998  Alan Cox        Fixed 2.1 symbols
  36 * May 17, 1998  K. Baranowski   Fixed SNAP encapsulation in wan_encapsulate
  37 * Dec 15, 1998  Arnaldo Melo    support for firmwares of up to 128000 bytes
  38 *                               check wandev->setup return value
  39 * Dec 22, 1998  Arnaldo Melo    vmalloc/vfree used in device_setup to allocate
  40 *                               kernel memory and copy configuration data to
  41 *                               kernel space (for big firmwares)
  42 * Jun 02, 1999  Gideon Hack     Updates for Linux 2.0.X and 2.2.X kernels.
  43 *****************************************************************************/
  44
  45 #include <linux/stddef.h>       /* offsetof(), etc. */
  46 #include <linux/capability.h>
  47 #include <linux/errno.h>        /* return codes */
  48 #include <linux/kernel.h>
  49 #include <linux/module.h>       /* support for loadable modules */
  50 #include <linux/slab.h>         /* kmalloc(), kfree() */
  51 #include <linux/mm.h>
  52 #include <linux/string.h>       /* inline mem*, str* functions */
  53
  54 #include <asm/byteorder.h>      /* htons(), etc. */
  55 #include <linux/wanrouter.h>    /* WAN router API definitions */
  56
  57 #include <linux/vmalloc.h>      /* vmalloc, vfree */
  58 #include <asm/uaccess.h>        /* copy_to/from_user */
  59 #include <linux/init.h>         /* __initfunc et al. */
  60
  61 #define KMEM_SAFETYZONE 8
  62
  63 #define DEV_TO_SLAVE(dev)       (*((struct net_device **)netdev_priv(dev)))
  64
  65 /*
  66  *      Function Prototypes
  67  */
  68
  69 /*
  70  *      WAN device IOCTL handlers
  71  */
  72
  73 static int wanrouter_device_setup(struct wan_device *wandev,
  74                                   wandev_conf_t __user *u_conf);
  75 static int wanrouter_device_stat(struct wan_device *wandev,
  76                                  wandev_stat_t __user *u_stat);
  77 static int wanrouter_device_shutdown(struct wan_device *wandev);
  78 static int wanrouter_device_new_if(struct wan_device *wandev,
  79                                    wanif_conf_t __user *u_conf);
  80 static int wanrouter_device_del_if(struct wan_device *wandev,
  81                                    char __user *u_name);
  82
  83 /*
  84  *      Miscellaneous
  85  */
  86
  87 static struct wan_device *wanrouter_find_device(char *name);
  88 static int wanrouter_delete_interface(struct wan_device *wandev, char *name);
  89 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags);
  90 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags);
  91
  92
  93
  94 /*
  95  *      Global Data
  96  */
  97
  98 static char wanrouter_fullname[]  = "Sangoma WANPIPE Router";
  99 static char wanrouter_copyright[] = "(c) 1995-2000 Sangoma Technologies Inc.";
 100 static char wanrouter_modname[] = ROUTER_NAME; /* short module name */
 101 struct wan_device* wanrouter_router_devlist; /* list of registered devices */
 102
 103 /*
 104  *      Organize Unique Identifiers for encapsulation/decapsulation
 105  */
 106
 107 #if 0
 108 static unsigned char wanrouter_oui_ether[] = { 0x00, 0x00, 0x00 };
 109 static unsigned char wanrouter_oui_802_2[] = { 0x00, 0x80, 0xC2 };
 110 #endif
 111
 112 static int __init wanrouter_init(void)
 113 {
 114         int err;
 115
 116         printk(KERN_INFO "%s v%u.%u %s\n",
 117                wanrouter_fullname, ROUTER_VERSION, ROUTER_RELEASE,
 118                wanrouter_copyright);
 119
 120         err = wanrouter_proc_init();
 121         if (err)
 122                 printk(KERN_INFO "%s: can't create entry in proc filesystem!\n",
 123                        wanrouter_modname);
 124
 125         return err;
 126 }
 127
 128 static void __exit wanrouter_cleanup (void)
 129 {
 130         wanrouter_proc_cleanup();
 131 }
 132
 133 /*
 134  * This is just plain dumb.  We should move the bugger to drivers/net/wan,
 135  * slap it first in directory and make it module_init().  The only reason
 136  * for subsys_initcall() here is that net goes after drivers (why, BTW?)
 137  */
 138 subsys_initcall(wanrouter_init);
 139 module_exit(wanrouter_cleanup);
 140
 141 /*
 142  *      Kernel APIs
 143  */
 144
 145 /*
 146  *      Register WAN device.
 147  *      o verify device credentials
 148  *      o create an entry for the device in the /proc/net/router directory
 149  *      o initialize internally maintained fields of the wan_device structure
 150  *      o link device data space to a singly-linked list
 151  *      o if it's the first device, then start kernel 'thread'
 152  *      o increment module use count
 153  *
 154  *      Return:
 155  *      0       Ok
 156  *      < 0     error.
 157  *
 158  *      Context:        process
 159  */
 160
 161
 162 int register_wan_device(struct wan_device *wandev)
 163 {
 164         int err, namelen;
 165
 166         if ((wandev == NULL) || (wandev->magic != ROUTER_MAGIC) ||
 167             (wandev->name == NULL))
 168                 return -EINVAL;
 169
 170         namelen = strlen(wandev->name);
 171         if (!namelen || (namelen > WAN_DRVNAME_SZ))
 172                 return -EINVAL;
 173
 174         if (wanrouter_find_device(wandev->name))
 175                 return -EEXIST;
 176
 177 #ifdef WANDEBUG
 178         printk(KERN_INFO "%s: registering WAN device %s\n",
 179                wanrouter_modname, wandev->name);
 180 #endif
 181
 182         /*
 183          *      Register /proc directory entry
 184          */
 185         err = wanrouter_proc_add(wandev);
 186         if (err) {
 187                 printk(KERN_INFO
 188                         "%s: can't create /proc/net/router/%s entry!\n",
 189                         wanrouter_modname, wandev->name);
 190                 return err;
 191         }
 192
 193         /*
 194          *      Initialize fields of the wan_device structure maintained by the
 195          *      router and update local data.
 196          */
 197
 198         wandev->ndev = 0;
 199         wandev->dev  = NULL;
 200         wandev->next = wanrouter_router_devlist;
 201         wanrouter_router_devlist = wandev;
 202         return 0;
 203 }
 204
 205 /*
 206  *      Unregister WAN device.
 207  *      o shut down device
 208  *      o unlink device data space from the linked list
 209  *      o delete device entry in the /proc/net/router directory
 210  *      o decrement module use count
 211  *
 212  *      Return:         0       Ok
 213  *                      <0      error.
 214  *      Context:        process
 215  */
 216
 217
 218 int unregister_wan_device(char *name)
 219 {
 220         struct wan_device *wandev, *prev;
 221
 222         if (name == NULL)
 223                 return -EINVAL;
 224
 225         for (wandev = wanrouter_router_devlist, prev = NULL;
 226                 wandev && strcmp(wandev->name, name);
 227                 prev = wandev, wandev = wandev->next)
 228                 ;
 229         if (wandev == NULL)
 230                 return -ENODEV;
 231
 232 #ifdef WANDEBUG
 233         printk(KERN_INFO "%s: unregistering WAN device %s\n",
 234                wanrouter_modname, name);
 235 #endif
 236
 237         if (wandev->state != WAN_UNCONFIGURED)
 238                 wanrouter_device_shutdown(wandev);
 239
 240         if (prev)
 241                 prev->next = wandev->next;
 242         else
 243                 wanrouter_router_devlist = wandev->next;
 244
 245         wanrouter_proc_delete(wandev);
 246         return 0;
 247 }
 248
 249 #if 0
 250
 251 /*
 252  *      Encapsulate packet.
 253  *
 254  *      Return: encapsulation header size
 255  *              < 0     - unsupported Ethertype
 256  *
 257  *      Notes:
 258  *      1. This function may be called on interrupt context.
 259  */
 260
 261
 262 int wanrouter_encapsulate(struct sk_buff *skb, struct net_device *dev,
 263                           unsigned short type)
 264 {
 265         int hdr_len = 0;
 266
 267         switch (type) {
 268         case ETH_P_IP:          /* IP datagram encapsulation */
 269                 hdr_len += 1;
 270                 skb_push(skb, 1);
 271                 skb->data[0] = NLPID_IP;
 272                 break;
 273
 274         case ETH_P_IPX:         /* SNAP encapsulation */
 275         case ETH_P_ARP:
 276                 hdr_len += 7;
 277                 skb_push(skb, 7);
 278                 skb->data[0] = 0;
 279                 skb->data[1] = NLPID_SNAP;
 280                 skb_copy_to_linear_data_offset(skb, 2, wanrouter_oui_ether,
 281                                                sizeof(wanrouter_oui_ether));
 282                 *((unsigned short*)&skb->data[5]) = htons(type);
 283                 break;
 284
 285         default:                /* Unknown packet type */
 286                 printk(KERN_INFO
 287                         "%s: unsupported Ethertype 0x%04X on interface %s!\n",
 288                         wanrouter_modname, type, dev->name);
 289                 hdr_len = -EINVAL;
 290         }
 291         return hdr_len;
 292 }
 293
 294
 295 /*
 296  *      Decapsulate packet.
 297  *
 298  *      Return: Ethertype (in network order)
 299  *                      0       unknown encapsulation
 300  *
 301  *      Notes:
 302  *      1. This function may be called on interrupt context.
 303  */
 304
 305
 306 __be16 wanrouter_type_trans(struct sk_buff *skb, struct net_device *dev)
 307 {
 308         int cnt = skb->data[0] ? 0 : 1; /* there may be a pad present */
 309         __be16 ethertype;
 310
 311         switch (skb->data[cnt]) {
 312         case NLPID_IP:          /* IP datagramm */
 313                 ethertype = htons(ETH_P_IP);
 314                 cnt += 1;
 315                 break;
 316
 317         case NLPID_SNAP:        /* SNAP encapsulation */
 318                 if (memcmp(&skb->data[cnt + 1], wanrouter_oui_ether,
 319                            sizeof(wanrouter_oui_ether))){
 320                         printk(KERN_INFO
 321                                 "%s: unsupported SNAP OUI %02X-%02X-%02X "
 322                                 "on interface %s!\n", wanrouter_modname,
 323                                 skb->data[cnt+1], skb->data[cnt+2],
 324                                 skb->data[cnt+3], dev->name);
 325                         return 0;
 326                 }
 327                 ethertype = *((__be16*)&skb->data[cnt+4]);
 328                 cnt += 6;
 329                 break;
 330
 331         /* add other protocols, e.g. CLNP, ESIS, ISIS, if needed */
 332
 333         default:
 334                 printk(KERN_INFO
 335                         "%s: unsupported NLPID 0x%02X on interface %s!\n",
 336                         wanrouter_modname, skb->data[cnt], dev->name);
 337                 return 0;
 338         }
 339         skb->protocol = ethertype;
 340         skb->pkt_type = PACKET_HOST;    /*      Physically point to point */
 341         skb_pull(skb, cnt);
 342         skb_reset_mac_header(skb);
 343         return ethertype;
 344 }
 345
 346 #endif  /*  0  */
 347
 348 /*
 349  *      WAN device IOCTL.
 350  *      o find WAN device associated with this node
 351  *      o execute requested action or pass command to the device driver
 352  */
 353
 354 long wanrouter_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 355 {
 356         struct inode *inode = file->f_path.dentry->d_inode;
 357         int err = 0;
 358         struct proc_dir_entry *dent;
 359         struct wan_device *wandev;
 360         void __user *data = (void __user *)arg;
 361
 362         if (!capable(CAP_NET_ADMIN))
 363                 return -EPERM;
 364
 365         if ((cmd >> 8) != ROUTER_IOCTL)
 366                 return -EINVAL;
 367
 368         dent = PDE(inode);
 369         if ((dent == NULL) || (dent->data == NULL))
 370                 return -EINVAL;
 371
 372         wandev = dent->data;
 373         if (wandev->magic != ROUTER_MAGIC)
 374                 return -EINVAL;
 375
 376         lock_kernel();
 377         switch (cmd) {
 378         case ROUTER_SETUP:
 379                 err = wanrouter_device_setup(wandev, data);
 380                 break;
 381
 382         case ROUTER_DOWN:
 383                 err = wanrouter_device_shutdown(wandev);
 384                 break;
 385
 386         case ROUTER_STAT:
 387                 err = wanrouter_device_stat(wandev, data);
 388                 break;
 389
 390         case ROUTER_IFNEW:
 391                 err = wanrouter_device_new_if(wandev, data);
 392                 break;
 393
 394         case ROUTER_IFDEL:
 395                 err = wanrouter_device_del_if(wandev, data);
 396                 break;
 397
 398         case ROUTER_IFSTAT:
 399                 break;
 400
 401         default:
 402                 if ((cmd >= ROUTER_USER) &&
 403                     (cmd <= ROUTER_USER_MAX) &&
 404                     wandev->ioctl)
 405                         err = wandev->ioctl(wandev, cmd, arg);
 406                 else err = -EINVAL;
 407         }
 408         unlock_kernel();
 409         return err;
 410 }
 411
 412 /*
 413  *      WAN Driver IOCTL Handlers
 414  */
 415
 416 /*
 417  *      Setup WAN link device.
 418  *      o verify user address space
 419  *      o allocate kernel memory and copy configuration data to kernel space
 420  *      o if configuration data includes extension, copy it to kernel space too
 421  *      o call driver's setup() entry point
 422  */
 423
 424 static int wanrouter_device_setup(struct wan_device *wandev,
 425                                   wandev_conf_t __user *u_conf)
 426 {
 427         void *data = NULL;
 428         wandev_conf_t *conf;
 429         int err = -EINVAL;
 430
 431         if (wandev->setup == NULL) {    /* Nothing to do ? */
 432                 printk(KERN_INFO "%s: ERROR, No setup script: wandev->setup()\n",
 433                                 wandev->name);
 434                 return 0;
 435         }
 436
 437         conf = kmalloc(sizeof(wandev_conf_t), GFP_KERNEL);
 438         if (conf == NULL){
 439                 printk(KERN_INFO "%s: ERROR, Failed to allocate kernel memory !\n",
 440                                 wandev->name);
 441                 return -ENOBUFS;
 442         }
 443
 444         if (copy_from_user(conf, u_conf, sizeof(wandev_conf_t))) {
 445                 printk(KERN_INFO "%s: Failed to copy user config data to kernel space!\n",
 446                                 wandev->name);
 447                 kfree(conf);
 448                 return -EFAULT;
 449         }
 450
 451         if (conf->magic != ROUTER_MAGIC) {
 452                 kfree(conf);
 453                 printk(KERN_INFO "%s: ERROR, Invalid MAGIC Number\n",
 454                                 wandev->name);
 455                 return -EINVAL;
 456         }
 457
 458         if (conf->data_size && conf->data) {
 459                 if (conf->data_size > 128000) {
 460                         printk(KERN_INFO
 461                             "%s: ERROR, Invalid firmware data size %i !\n",
 462                                         wandev->name, conf->data_size);
 463                         kfree(conf);
 464                         return -EINVAL;
 465                 }
 466
 467                 data = vmalloc(conf->data_size);
 468                 if (!data) {
 469                         printk(KERN_INFO
 470                                 "%s: ERROR, Faild allocate kernel memory !\n",
 471                                 wandev->name);
 472                         kfree(conf);
 473                         return -ENOBUFS;
 474                 }
 475                 if (!copy_from_user(data, conf->data, conf->data_size)) {
 476                         conf->data = data;
 477                         err = wandev->setup(wandev, conf);
 478                 } else {
 479                         printk(KERN_INFO
 480                              "%s: ERROR, Faild to copy from user data !\n",
 481                                wandev->name);
 482                         err = -EFAULT;
 483                 }
 484                 vfree(data);
 485         } else {
 486                 printk(KERN_INFO
 487                     "%s: ERROR, No firmware found ! Firmware size = %i !\n",
 488                                 wandev->name, conf->data_size);
 489         }
 490
 491         kfree(conf);
 492         return err;
 493 }
 494
 495 /*
 496  *      Shutdown WAN device.
 497  *      o delete all not opened logical channels for this device
 498  *      o call driver's shutdown() entry point
 499  */
 500
 501 static int wanrouter_device_shutdown(struct wan_device *wandev)
 502 {
 503         struct net_device *dev;
 504         int err=0;
 505
 506         if (wandev->state == WAN_UNCONFIGURED)
 507                 return 0;
 508
 509         printk(KERN_INFO "\n%s: Shutting Down!\n",wandev->name);
 510
 511         for (dev = wandev->dev; dev;) {
 512                 err = wanrouter_delete_interface(wandev, dev->name);
 513                 if (err)
 514                         return err;
 515                 /* The above function deallocates the current dev
 516                  * structure. Therefore, we cannot use netdev_priv(dev)
 517                  * as the next element: wandev->dev points to the
 518                  * next element */
 519                 dev = wandev->dev;
 520         }
 521
 522         if (wandev->ndev)
 523                 return -EBUSY;  /* there are opened interfaces  */
 524
 525         if (wandev->shutdown)
 526                 err=wandev->shutdown(wandev);
 527
 528         return err;
 529 }
 530
 531 /*
 532  *      Get WAN device status & statistics.
 533  */
 534
 535 static int wanrouter_device_stat(struct wan_device *wandev,
 536                                  wandev_stat_t __user *u_stat)
 537 {
 538         wandev_stat_t stat;
 539
 540         memset(&stat, 0, sizeof(stat));
 541
 542         /* Ask device driver to update device statistics */
 543         if ((wandev->state != WAN_UNCONFIGURED) && wandev->update)
 544                 wandev->update(wandev);
 545
 546         /* Fill out structure */
 547         stat.ndev  = wandev->ndev;
 548         stat.state = wandev->state;
 549
 550         if (copy_to_user(u_stat, &stat, sizeof(stat)))
 551                 return -EFAULT;
 552
 553         return 0;
 554 }
 555
 556 /*
 557  *      Create new WAN interface.
 558  *      o verify user address space
 559  *      o copy configuration data to kernel address space
 560  *      o allocate network interface data space
 561  *      o call driver's new_if() entry point
 562  *      o make sure there is no interface name conflict
 563  *      o register network interface
 564  */
 565
 566 static int wanrouter_device_new_if(struct wan_device *wandev,
 567                                    wanif_conf_t __user *u_conf)
 568 {
 569         wanif_conf_t *cnf;
 570         struct net_device *dev = NULL;
 571         int err;
 572
 573         if ((wandev->state == WAN_UNCONFIGURED) || (wandev->new_if == NULL))
 574                 return -ENODEV;
 575
 576         cnf = kmalloc(sizeof(wanif_conf_t), GFP_KERNEL);
 577         if (!cnf)
 578                 return -ENOBUFS;
 579
 580         err = -EFAULT;
 581         if (copy_from_user(cnf, u_conf, sizeof(wanif_conf_t)))
 582                 goto out;
 583
 584         err = -EINVAL;
 585         if (cnf->magic != ROUTER_MAGIC)
 586                 goto out;
 587
 588         if (cnf->config_id == WANCONFIG_MPPP) {
 589                 printk(KERN_INFO "%s: Wanpipe Mulit-Port PPP support has not been compiled in!\n",
 590                                 wandev->name);
 591                 err = -EPROTONOSUPPORT;
 592                 goto out;
 593         } else {
 594                 err = wandev->new_if(wandev, dev, cnf);
 595         }
 596
 597         if (!err) {
 598                 /* Register network interface. This will invoke init()
 599                  * function supplied by the driver.  If device registered
 600                  * successfully, add it to the interface list.
 601                  */
 602
 603                 if (dev->name == NULL) {
 604                         err = -EINVAL;
 605                 } else {
 606
 607                         #ifdef WANDEBUG
 608                         printk(KERN_INFO "%s: registering interface %s...\n",
 609                                 wanrouter_modname, dev->name);
 610                         #endif
 611
 612                         err = register_netdev(dev);
 613                         if (!err) {
 614                                 struct net_device *slave = NULL;
 615                                 unsigned long smp_flags=0;
 616
 617                                 lock_adapter_irq(&wandev->lock, &smp_flags);
 618
 619                                 if (wandev->dev == NULL) {
 620                                         wandev->dev = dev;
 621                                 } else {
 622                                         for (slave=wandev->dev;
 623                                              DEV_TO_SLAVE(slave);
 624                                              slave = DEV_TO_SLAVE(slave))
 625                                                 DEV_TO_SLAVE(slave) = dev;
 626                                 }
 627                                 ++wandev->ndev;
 628
 629                                 unlock_adapter_irq(&wandev->lock, &smp_flags);
 630                                 err = 0;        /* done !!! */
 631                                 goto out;
 632                         }
 633                 }
 634                 if (wandev->del_if)
 635                         wandev->del_if(wandev, dev);
 636                 free_netdev(dev);
 637         }
 638
 639 out:
 640         kfree(cnf);
 641         return err;
 642 }
 643
 644
 645 /*
 646  *      Delete WAN logical channel.
 647  *       o verify user address space
 648  *       o copy configuration data to kernel address space
 649  */
 650
 651 static int wanrouter_device_del_if(struct wan_device *wandev, char __user *u_name)
 652 {
 653         char name[WAN_IFNAME_SZ + 1];
 654         int err = 0;
 655
 656         if (wandev->state == WAN_UNCONFIGURED)
 657                 return -ENODEV;
 658
 659         memset(name, 0, sizeof(name));
 660
 661         if (copy_from_user(name, u_name, WAN_IFNAME_SZ))
 662                 return -EFAULT;
 663
 664         err = wanrouter_delete_interface(wandev, name);
 665         if (err)
 666                 return err;
 667
 668         /* If last interface being deleted, shutdown card
 669          * This helps with administration at leaf nodes
 670          * (You can tell if the person at the other end of the phone
 671          * has an interface configured) and avoids DoS vulnerabilities
 672          * in binary driver files - this fixes a problem with the current
 673          * Sangoma driver going into strange states when all the network
 674          * interfaces are deleted and the link irrecoverably disconnected.
 675          */
 676
 677         if (!wandev->ndev && wandev->shutdown)
 678                 err = wandev->shutdown(wandev);
 679
 680         return err;
 681 }
 682
 683 /*
 684  *      Miscellaneous Functions
 685  */
 686
 687 /*
 688  *      Find WAN device by name.
 689  *      Return pointer to the WAN device data space or NULL if device not found.
 690  */
 691
 692 static struct wan_device *wanrouter_find_device(char *name)
 693 {
 694         struct wan_device *wandev;
 695
 696         for (wandev = wanrouter_router_devlist;
 697              wandev && strcmp(wandev->name, name);
 698                 wandev = wandev->next);
 699         return wandev;
 700 }
 701
 702 /*
 703  *      Delete WAN logical channel identified by its name.
 704  *      o find logical channel by its name
 705  *      o call driver's del_if() entry point
 706  *      o unregister network interface
 707  *      o unlink channel data space from linked list of channels
 708  *      o release channel data space
 709  *
 710  *      Return: 0               success
 711  *              -ENODEV         channel not found.
 712  *              -EBUSY          interface is open
 713  *
 714  *      Note: If (force != 0), then device will be destroyed even if interface
 715  *      associated with it is open. It's caller's responsibility to make
 716  *      sure that opened interfaces are not removed!
 717  */
 718
 719 static int wanrouter_delete_interface(struct wan_device *wandev, char *name)
 720 {
 721         struct net_device *dev = NULL, *prev = NULL;
 722         unsigned long smp_flags=0;
 723
 724         lock_adapter_irq(&wandev->lock, &smp_flags);
 725         dev = wandev->dev;
 726         prev = NULL;
 727         while (dev && strcmp(name, dev->name)) {
 728                 struct net_device **slave = netdev_priv(dev);
 729                 prev = dev;
 730                 dev = *slave;
 731         }
 732         unlock_adapter_irq(&wandev->lock, &smp_flags);
 733
 734         if (dev == NULL)
 735                 return -ENODEV; /* interface not found */
 736
 737         if (netif_running(dev))
 738                 return -EBUSY;  /* interface in use */
 739
 740         if (wandev->del_if)
 741                 wandev->del_if(wandev, dev);
 742
 743         lock_adapter_irq(&wandev->lock, &smp_flags);
 744         if (prev) {
 745                 struct net_device **prev_slave = netdev_priv(prev);
 746                 struct net_device **slave = netdev_priv(dev);
 747
 748                 *prev_slave = *slave;
 749         } else {
 750                 struct net_device **slave = netdev_priv(dev);
 751                 wandev->dev = *slave;
 752         }
 753         --wandev->ndev;
 754         unlock_adapter_irq(&wandev->lock, &smp_flags);
 755
 756         printk(KERN_INFO "%s: unregistering '%s'\n", wandev->name, dev->name);
 757
 758         unregister_netdev(dev);
 759
 760         free_netdev(dev);
 761
 762         return 0;
 763 }
 764
 765 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
 766 {
 767         spin_lock_irqsave(lock, *smp_flags);
 768 }
 769
 770
 771 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
 772 {
 773         spin_unlock_irqrestore(lock, *smp_flags);
 774 }
 775
 776 EXPORT_SYMBOL(register_wan_device);
 777 EXPORT_SYMBOL(unregister_wan_device);
 778
 779 MODULE_LICENSE("GPL");
 780
 781 /*
 782  *      End
 783  */