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         __acquires(lock);
  91 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
  92         __releases(lock);
  93
  94
  95
  96 /*
  97  *      Global Data
  98  */
  99
 100 static char wanrouter_fullname[]  = "Sangoma WANPIPE Router";
 101 static char wanrouter_copyright[] = "(c) 1995-2000 Sangoma Technologies Inc.";
 102 static char wanrouter_modname[] = ROUTER_NAME; /* short module name */
 103 struct wan_device* wanrouter_router_devlist; /* list of registered devices */
 104
 105 /*
 106  *      Organize Unique Identifiers for encapsulation/decapsulation
 107  */
 108
 109 #if 0
 110 static unsigned char wanrouter_oui_ether[] = { 0x00, 0x00, 0x00 };
 111 static unsigned char wanrouter_oui_802_2[] = { 0x00, 0x80, 0xC2 };
 112 #endif
 113
 114 static int __init wanrouter_init(void)
 115 {
 116         int err;
 117
 118         printk(KERN_INFO "%s v%u.%u %s\n",
 119                wanrouter_fullname, ROUTER_VERSION, ROUTER_RELEASE,
 120                wanrouter_copyright);
 121
 122         err = wanrouter_proc_init();
 123         if (err)
 124                 printk(KERN_INFO "%s: can't create entry in proc filesystem!\n",
 125                        wanrouter_modname);
 126
 127         return err;
 128 }
 129
 130 static void __exit wanrouter_cleanup (void)
 131 {
 132         wanrouter_proc_cleanup();
 133 }
 134
 135 /*
 136  * This is just plain dumb.  We should move the bugger to drivers/net/wan,
 137  * slap it first in directory and make it module_init().  The only reason
 138  * for subsys_initcall() here is that net goes after drivers (why, BTW?)
 139  */
 140 subsys_initcall(wanrouter_init);
 141 module_exit(wanrouter_cleanup);
 142
 143 /*
 144  *      Kernel APIs
 145  */
 146
 147 /*
 148  *      Register WAN device.
 149  *      o verify device credentials
 150  *      o create an entry for the device in the /proc/net/router directory
 151  *      o initialize internally maintained fields of the wan_device structure
 152  *      o link device data space to a singly-linked list
 153  *      o if it's the first device, then start kernel 'thread'
 154  *      o increment module use count
 155  *
 156  *      Return:
 157  *      0       Ok
 158  *      < 0     error.
 159  *
 160  *      Context:        process
 161  */
 162
 163
 164 int register_wan_device(struct wan_device *wandev)
 165 {
 166         int err, namelen;
 167
 168         if ((wandev == NULL) || (wandev->magic != ROUTER_MAGIC) ||
 169             (wandev->name == NULL))
 170                 return -EINVAL;
 171
 172         namelen = strlen(wandev->name);
 173         if (!namelen || (namelen > WAN_DRVNAME_SZ))
 174                 return -EINVAL;
 175
 176         if (wanrouter_find_device(wandev->name))
 177                 return -EEXIST;
 178
 179 #ifdef WANDEBUG
 180         printk(KERN_INFO "%s: registering WAN device %s\n",
 181                wanrouter_modname, wandev->name);
 182 #endif
 183
 184         /*
 185          *      Register /proc directory entry
 186          */
 187         err = wanrouter_proc_add(wandev);
 188         if (err) {
 189                 printk(KERN_INFO
 190                         "%s: can't create /proc/net/router/%s entry!\n",
 191                         wanrouter_modname, wandev->name);
 192                 return err;
 193         }
 194
 195         /*
 196          *      Initialize fields of the wan_device structure maintained by the
 197          *      router and update local data.
 198          */
 199
 200         wandev->ndev = 0;
 201         wandev->dev  = NULL;
 202         wandev->next = wanrouter_router_devlist;
 203         wanrouter_router_devlist = wandev;
 204         return 0;
 205 }
 206
 207 /*
 208  *      Unregister WAN device.
 209  *      o shut down device
 210  *      o unlink device data space from the linked list
 211  *      o delete device entry in the /proc/net/router directory
 212  *      o decrement module use count
 213  *
 214  *      Return:         0       Ok
 215  *                      <0      error.
 216  *      Context:        process
 217  */
 218
 219
 220 int unregister_wan_device(char *name)
 221 {
 222         struct wan_device *wandev, *prev;
 223
 224         if (name == NULL)
 225                 return -EINVAL;
 226
 227         for (wandev = wanrouter_router_devlist, prev = NULL;
 228                 wandev && strcmp(wandev->name, name);
 229                 prev = wandev, wandev = wandev->next)
 230                 ;
 231         if (wandev == NULL)
 232                 return -ENODEV;
 233
 234 #ifdef WANDEBUG
 235         printk(KERN_INFO "%s: unregistering WAN device %s\n",
 236                wanrouter_modname, name);
 237 #endif
 238
 239         if (wandev->state != WAN_UNCONFIGURED)
 240                 wanrouter_device_shutdown(wandev);
 241
 242         if (prev)
 243                 prev->next = wandev->next;
 244         else
 245                 wanrouter_router_devlist = wandev->next;
 246
 247         wanrouter_proc_delete(wandev);
 248         return 0;
 249 }
 250
 251 #if 0
 252
 253 /*
 254  *      Encapsulate packet.
 255  *
 256  *      Return: encapsulation header size
 257  *              < 0     - unsupported Ethertype
 258  *
 259  *      Notes:
 260  *      1. This function may be called on interrupt context.
 261  */
 262
 263
 264 int wanrouter_encapsulate(struct sk_buff *skb, struct net_device *dev,
 265                           unsigned short type)
 266 {
 267         int hdr_len = 0;
 268
 269         switch (type) {
 270         case ETH_P_IP:          /* IP datagram encapsulation */
 271                 hdr_len += 1;
 272                 skb_push(skb, 1);
 273                 skb->data[0] = NLPID_IP;
 274                 break;
 275
 276         case ETH_P_IPX:         /* SNAP encapsulation */
 277         case ETH_P_ARP:
 278                 hdr_len += 7;
 279                 skb_push(skb, 7);
 280                 skb->data[0] = 0;
 281                 skb->data[1] = NLPID_SNAP;
 282                 skb_copy_to_linear_data_offset(skb, 2, wanrouter_oui_ether,
 283                                                sizeof(wanrouter_oui_ether));
 284                 *((unsigned short*)&skb->data[5]) = htons(type);
 285                 break;
 286
 287         default:                /* Unknown packet type */
 288                 printk(KERN_INFO
 289                         "%s: unsupported Ethertype 0x%04X on interface %s!\n",
 290                         wanrouter_modname, type, dev->name);
 291                 hdr_len = -EINVAL;
 292         }
 293         return hdr_len;
 294 }
 295
 296
 297 /*
 298  *      Decapsulate packet.
 299  *
 300  *      Return: Ethertype (in network order)
 301  *                      0       unknown encapsulation
 302  *
 303  *      Notes:
 304  *      1. This function may be called on interrupt context.
 305  */
 306
 307
 308 __be16 wanrouter_type_trans(struct sk_buff *skb, struct net_device *dev)
 309 {
 310         int cnt = skb->data[0] ? 0 : 1; /* there may be a pad present */
 311         __be16 ethertype;
 312
 313         switch (skb->data[cnt]) {
 314         case NLPID_IP:          /* IP datagramm */
 315                 ethertype = htons(ETH_P_IP);
 316                 cnt += 1;
 317                 break;
 318
 319         case NLPID_SNAP:        /* SNAP encapsulation */
 320                 if (memcmp(&skb->data[cnt + 1], wanrouter_oui_ether,
 321                            sizeof(wanrouter_oui_ether))){
 322                         printk(KERN_INFO
 323                                 "%s: unsupported SNAP OUI %02X-%02X-%02X "
 324                                 "on interface %s!\n", wanrouter_modname,
 325                                 skb->data[cnt+1], skb->data[cnt+2],
 326                                 skb->data[cnt+3], dev->name);
 327                         return 0;
 328                 }
 329                 ethertype = *((__be16*)&skb->data[cnt+4]);
 330                 cnt += 6;
 331                 break;
 332
 333         /* add other protocols, e.g. CLNP, ESIS, ISIS, if needed */
 334
 335         default:
 336                 printk(KERN_INFO
 337                         "%s: unsupported NLPID 0x%02X on interface %s!\n",
 338                         wanrouter_modname, skb->data[cnt], dev->name);
 339                 return 0;
 340         }
 341         skb->protocol = ethertype;
 342         skb->pkt_type = PACKET_HOST;    /*      Physically point to point */
 343         skb_pull(skb, cnt);
 344         skb_reset_mac_header(skb);
 345         return ethertype;
 346 }
 347
 348 #endif  /*  0  */
 349
 350 /*
 351  *      WAN device IOCTL.
 352  *      o find WAN device associated with this node
 353  *      o execute requested action or pass command to the device driver
 354  */
 355
 356 long wanrouter_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 357 {
 358         struct inode *inode = file->f_path.dentry->d_inode;
 359         int err = 0;
 360         struct proc_dir_entry *dent;
 361         struct wan_device *wandev;
 362         void __user *data = (void __user *)arg;
 363
 364         if (!capable(CAP_NET_ADMIN))
 365                 return -EPERM;
 366
 367         if ((cmd >> 8) != ROUTER_IOCTL)
 368                 return -EINVAL;
 369
 370         dent = PDE(inode);
 371         if ((dent == NULL) || (dent->data == NULL))
 372                 return -EINVAL;
 373
 374         wandev = dent->data;
 375         if (wandev->magic != ROUTER_MAGIC)
 376                 return -EINVAL;
 377
 378         lock_kernel();
 379         switch (cmd) {
 380         case ROUTER_SETUP:
 381                 err = wanrouter_device_setup(wandev, data);
 382                 break;
 383
 384         case ROUTER_DOWN:
 385                 err = wanrouter_device_shutdown(wandev);
 386                 break;
 387
 388         case ROUTER_STAT:
 389                 err = wanrouter_device_stat(wandev, data);
 390                 break;
 391
 392         case ROUTER_IFNEW:
 393                 err = wanrouter_device_new_if(wandev, data);
 394                 break;
 395
 396         case ROUTER_IFDEL:
 397                 err = wanrouter_device_del_if(wandev, data);
 398                 break;
 399
 400         case ROUTER_IFSTAT:
 401                 break;
 402
 403         default:
 404                 if ((cmd >= ROUTER_USER) &&
 405                     (cmd <= ROUTER_USER_MAX) &&
 406                     wandev->ioctl)
 407                         err = wandev->ioctl(wandev, cmd, arg);
 408                 else err = -EINVAL;
 409         }
 410         unlock_kernel();
 411         return err;
 412 }
 413
 414 /*
 415  *      WAN Driver IOCTL Handlers
 416  */
 417
 418 /*
 419  *      Setup WAN link device.
 420  *      o verify user address space
 421  *      o allocate kernel memory and copy configuration data to kernel space
 422  *      o if configuration data includes extension, copy it to kernel space too
 423  *      o call driver's setup() entry point
 424  */
 425
 426 static int wanrouter_device_setup(struct wan_device *wandev,
 427                                   wandev_conf_t __user *u_conf)
 428 {
 429         void *data = NULL;
 430         wandev_conf_t *conf;
 431         int err = -EINVAL;
 432
 433         if (wandev->setup == NULL) {    /* Nothing to do ? */
 434                 printk(KERN_INFO "%s: ERROR, No setup script: wandev->setup()\n",
 435                                 wandev->name);
 436                 return 0;
 437         }
 438
 439         conf = kmalloc(sizeof(wandev_conf_t), GFP_KERNEL);
 440         if (conf == NULL){
 441                 printk(KERN_INFO "%s: ERROR, Failed to allocate kernel memory !\n",
 442                                 wandev->name);
 443                 return -ENOBUFS;
 444         }
 445
 446         if (copy_from_user(conf, u_conf, sizeof(wandev_conf_t))) {
 447                 printk(KERN_INFO "%s: Failed to copy user config data to kernel space!\n",
 448                                 wandev->name);
 449                 kfree(conf);
 450                 return -EFAULT;
 451         }
 452
 453         if (conf->magic != ROUTER_MAGIC) {
 454                 kfree(conf);
 455                 printk(KERN_INFO "%s: ERROR, Invalid MAGIC Number\n",
 456                                 wandev->name);
 457                 return -EINVAL;
 458         }
 459
 460         if (conf->data_size && conf->data) {
 461                 if (conf->data_size > 128000) {
 462                         printk(KERN_INFO
 463                             "%s: ERROR, Invalid firmware data size %i !\n",
 464                                         wandev->name, conf->data_size);
 465                         kfree(conf);
 466                         return -EINVAL;
 467                 }
 468
 469                 data = vmalloc(conf->data_size);
 470                 if (!data) {
 471                         printk(KERN_INFO
 472                                 "%s: ERROR, Faild allocate kernel memory !\n",
 473                                 wandev->name);
 474                         kfree(conf);
 475                         return -ENOBUFS;
 476                 }
 477                 if (!copy_from_user(data, conf->data, conf->data_size)) {
 478                         conf->data = data;
 479                         err = wandev->setup(wandev, conf);
 480                 } else {
 481                         printk(KERN_INFO
 482                              "%s: ERROR, Faild to copy from user data !\n",
 483                                wandev->name);
 484                         err = -EFAULT;
 485                 }
 486                 vfree(data);
 487         } else {
 488                 printk(KERN_INFO
 489                     "%s: ERROR, No firmware found ! Firmware size = %i !\n",
 490                                 wandev->name, conf->data_size);
 491         }
 492
 493         kfree(conf);
 494         return err;
 495 }
 496
 497 /*
 498  *      Shutdown WAN device.
 499  *      o delete all not opened logical channels for this device
 500  *      o call driver's shutdown() entry point
 501  */
 502
 503 static int wanrouter_device_shutdown(struct wan_device *wandev)
 504 {
 505         struct net_device *dev;
 506         int err=0;
 507
 508         if (wandev->state == WAN_UNCONFIGURED)
 509                 return 0;
 510
 511         printk(KERN_INFO "\n%s: Shutting Down!\n",wandev->name);
 512
 513         for (dev = wandev->dev; dev;) {
 514                 err = wanrouter_delete_interface(wandev, dev->name);
 515                 if (err)
 516                         return err;
 517                 /* The above function deallocates the current dev
 518                  * structure. Therefore, we cannot use netdev_priv(dev)
 519                  * as the next element: wandev->dev points to the
 520                  * next element */
 521                 dev = wandev->dev;
 522         }
 523
 524         if (wandev->ndev)
 525                 return -EBUSY;  /* there are opened interfaces  */
 526
 527         if (wandev->shutdown)
 528                 err=wandev->shutdown(wandev);
 529
 530         return err;
 531 }
 532
 533 /*
 534  *      Get WAN device status & statistics.
 535  */
 536
 537 static int wanrouter_device_stat(struct wan_device *wandev,
 538                                  wandev_stat_t __user *u_stat)
 539 {
 540         wandev_stat_t stat;
 541
 542         memset(&stat, 0, sizeof(stat));
 543
 544         /* Ask device driver to update device statistics */
 545         if ((wandev->state != WAN_UNCONFIGURED) && wandev->update)
 546                 wandev->update(wandev);
 547
 548         /* Fill out structure */
 549         stat.ndev  = wandev->ndev;
 550         stat.state = wandev->state;
 551
 552         if (copy_to_user(u_stat, &stat, sizeof(stat)))
 553                 return -EFAULT;
 554
 555         return 0;
 556 }
 557
 558 /*
 559  *      Create new WAN interface.
 560  *      o verify user address space
 561  *      o copy configuration data to kernel address space
 562  *      o allocate network interface data space
 563  *      o call driver's new_if() entry point
 564  *      o make sure there is no interface name conflict
 565  *      o register network interface
 566  */
 567
 568 static int wanrouter_device_new_if(struct wan_device *wandev,
 569                                    wanif_conf_t __user *u_conf)
 570 {
 571         wanif_conf_t *cnf;
 572         struct net_device *dev = NULL;
 573         int err;
 574
 575         if ((wandev->state == WAN_UNCONFIGURED) || (wandev->new_if == NULL))
 576                 return -ENODEV;
 577
 578         cnf = kmalloc(sizeof(wanif_conf_t), GFP_KERNEL);
 579         if (!cnf)
 580                 return -ENOBUFS;
 581
 582         err = -EFAULT;
 583         if (copy_from_user(cnf, u_conf, sizeof(wanif_conf_t)))
 584                 goto out;
 585
 586         err = -EINVAL;
 587         if (cnf->magic != ROUTER_MAGIC)
 588                 goto out;
 589
 590         if (cnf->config_id == WANCONFIG_MPPP) {
 591                 printk(KERN_INFO "%s: Wanpipe Mulit-Port PPP support has not been compiled in!\n",
 592                                 wandev->name);
 593                 err = -EPROTONOSUPPORT;
 594                 goto out;
 595         } else {
 596                 err = wandev->new_if(wandev, dev, cnf);
 597         }
 598
 599         if (!err) {
 600                 /* Register network interface. This will invoke init()
 601                  * function supplied by the driver.  If device registered
 602                  * successfully, add it to the interface list.
 603                  */
 604
 605                 if (dev->name == NULL) {
 606                         err = -EINVAL;
 607                 } else {
 608
 609                         #ifdef WANDEBUG
 610                         printk(KERN_INFO "%s: registering interface %s...\n",
 611                                 wanrouter_modname, dev->name);
 612                         #endif
 613
 614                         err = register_netdev(dev);
 615                         if (!err) {
 616                                 struct net_device *slave = NULL;
 617                                 unsigned long smp_flags=0;
 618
 619                                 lock_adapter_irq(&wandev->lock, &smp_flags);
 620
 621                                 if (wandev->dev == NULL) {
 622                                         wandev->dev = dev;
 623                                 } else {
 624                                         for (slave=wandev->dev;
 625                                              DEV_TO_SLAVE(slave);
 626                                              slave = DEV_TO_SLAVE(slave))
 627                                                 DEV_TO_SLAVE(slave) = dev;
 628                                 }
 629                                 ++wandev->ndev;
 630
 631                                 unlock_adapter_irq(&wandev->lock, &smp_flags);
 632                                 err = 0;        /* done !!! */
 633                                 goto out;
 634                         }
 635                 }
 636                 if (wandev->del_if)
 637                         wandev->del_if(wandev, dev);
 638                 free_netdev(dev);
 639         }
 640
 641 out:
 642         kfree(cnf);
 643         return err;
 644 }
 645
 646
 647 /*
 648  *      Delete WAN logical channel.
 649  *       o verify user address space
 650  *       o copy configuration data to kernel address space
 651  */
 652
 653 static int wanrouter_device_del_if(struct wan_device *wandev, char __user *u_name)
 654 {
 655         char name[WAN_IFNAME_SZ + 1];
 656         int err = 0;
 657
 658         if (wandev->state == WAN_UNCONFIGURED)
 659                 return -ENODEV;
 660
 661         memset(name, 0, sizeof(name));
 662
 663         if (copy_from_user(name, u_name, WAN_IFNAME_SZ))
 664                 return -EFAULT;
 665
 666         err = wanrouter_delete_interface(wandev, name);
 667         if (err)
 668                 return err;
 669
 670         /* If last interface being deleted, shutdown card
 671          * This helps with administration at leaf nodes
 672          * (You can tell if the person at the other end of the phone
 673          * has an interface configured) and avoids DoS vulnerabilities
 674          * in binary driver files - this fixes a problem with the current
 675          * Sangoma driver going into strange states when all the network
 676          * interfaces are deleted and the link irrecoverably disconnected.
 677          */
 678
 679         if (!wandev->ndev && wandev->shutdown)
 680                 err = wandev->shutdown(wandev);
 681
 682         return err;
 683 }
 684
 685 /*
 686  *      Miscellaneous Functions
 687  */
 688
 689 /*
 690  *      Find WAN device by name.
 691  *      Return pointer to the WAN device data space or NULL if device not found.
 692  */
 693
 694 static struct wan_device *wanrouter_find_device(char *name)
 695 {
 696         struct wan_device *wandev;
 697
 698         for (wandev = wanrouter_router_devlist;
 699              wandev && strcmp(wandev->name, name);
 700                 wandev = wandev->next);
 701         return wandev;
 702 }
 703
 704 /*
 705  *      Delete WAN logical channel identified by its name.
 706  *      o find logical channel by its name
 707  *      o call driver's del_if() entry point
 708  *      o unregister network interface
 709  *      o unlink channel data space from linked list of channels
 710  *      o release channel data space
 711  *
 712  *      Return: 0               success
 713  *              -ENODEV         channel not found.
 714  *              -EBUSY          interface is open
 715  *
 716  *      Note: If (force != 0), then device will be destroyed even if interface
 717  *      associated with it is open. It's caller's responsibility to make
 718  *      sure that opened interfaces are not removed!
 719  */
 720
 721 static int wanrouter_delete_interface(struct wan_device *wandev, char *name)
 722 {
 723         struct net_device *dev = NULL, *prev = NULL;
 724         unsigned long smp_flags=0;
 725
 726         lock_adapter_irq(&wandev->lock, &smp_flags);
 727         dev = wandev->dev;
 728         prev = NULL;
 729         while (dev && strcmp(name, dev->name)) {
 730                 struct net_device **slave = netdev_priv(dev);
 731                 prev = dev;
 732                 dev = *slave;
 733         }
 734         unlock_adapter_irq(&wandev->lock, &smp_flags);
 735
 736         if (dev == NULL)
 737                 return -ENODEV; /* interface not found */
 738
 739         if (netif_running(dev))
 740                 return -EBUSY;  /* interface in use */
 741
 742         if (wandev->del_if)
 743                 wandev->del_if(wandev, dev);
 744
 745         lock_adapter_irq(&wandev->lock, &smp_flags);
 746         if (prev) {
 747                 struct net_device **prev_slave = netdev_priv(prev);
 748                 struct net_device **slave = netdev_priv(dev);
 749
 750                 *prev_slave = *slave;
 751         } else {
 752                 struct net_device **slave = netdev_priv(dev);
 753                 wandev->dev = *slave;
 754         }
 755         --wandev->ndev;
 756         unlock_adapter_irq(&wandev->lock, &smp_flags);
 757
 758         printk(KERN_INFO "%s: unregistering '%s'\n", wandev->name, dev->name);
 759
 760         unregister_netdev(dev);
 761
 762         free_netdev(dev);
 763
 764         return 0;
 765 }
 766
 767 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
 768         __acquires(lock)
 769 {
 770         spin_lock_irqsave(lock, *smp_flags);
 771 }
 772
 773
 774 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
 775         __releases(lock)
 776 {
 777         spin_unlock_irqrestore(lock, *smp_flags);
 778 }
 779
 780 EXPORT_SYMBOL(register_wan_device);
 781 EXPORT_SYMBOL(unregister_wan_device);
 782
 783 MODULE_LICENSE("GPL");
 784
 785 /*
 786  *      End
 787  */