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/smp_lock.h>
  52 #include <linux/mm.h>
  53 #include <linux/string.h>       /* inline mem*, str* functions */
  54
  55 #include <asm/byteorder.h>      /* htons(), etc. */
  56 #include <linux/wanrouter.h>    /* WAN router API definitions */
  57
  58 #include <linux/vmalloc.h>      /* vmalloc, vfree */
  59 #include <asm/uaccess.h>        /* copy_to/from_user */
  60 #include <linux/init.h>         /* __initfunc et al. */
  61
  62 #define KMEM_SAFETYZONE 8
  63
  64 #define DEV_TO_SLAVE(dev)       (*((struct net_device **)netdev_priv(dev)))
  65
  66 /*
  67  *      Function Prototypes
  68  */
  69
  70 /*
  71  *      WAN device IOCTL handlers
  72  */
  73
  74 static int wanrouter_device_setup(struct wan_device *wandev,
  75                                   wandev_conf_t __user *u_conf);
  76 static int wanrouter_device_stat(struct wan_device *wandev,
  77                                  wandev_stat_t __user *u_stat);
  78 static int wanrouter_device_shutdown(struct wan_device *wandev);
  79 static int wanrouter_device_new_if(struct wan_device *wandev,
  80                                    wanif_conf_t __user *u_conf);
  81 static int wanrouter_device_del_if(struct wan_device *wandev,
  82                                    char __user *u_name);
  83
  84 /*
  85  *      Miscellaneous
  86  */
  87
  88 static struct wan_device *wanrouter_find_device(char *name);
  89 static int wanrouter_delete_interface(struct wan_device *wandev, char *name);
  90 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
  91         __acquires(lock);
  92 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
  93         __releases(lock);
  94
  95
  96
  97 /*
  98  *      Global Data
  99  */
 100
 101 static char wanrouter_fullname[]  = "Sangoma WANPIPE Router";
 102 static char wanrouter_copyright[] = "(c) 1995-2000 Sangoma Technologies Inc.";
 103 static char wanrouter_modname[] = ROUTER_NAME; /* short module name */
 104 struct wan_device* wanrouter_router_devlist; /* list of registered devices */
 105
 106 /*
 107  *      Organize Unique Identifiers for encapsulation/decapsulation
 108  */
 109
 110 #if 0
 111 static unsigned char wanrouter_oui_ether[] = { 0x00, 0x00, 0x00 };
 112 static unsigned char wanrouter_oui_802_2[] = { 0x00, 0x80, 0xC2 };
 113 #endif
 114
 115 static int __init wanrouter_init(void)
 116 {
 117         int err;
 118
 119         printk(KERN_INFO "%s v%u.%u %s\n",
 120                wanrouter_fullname, ROUTER_VERSION, ROUTER_RELEASE,
 121                wanrouter_copyright);
 122
 123         err = wanrouter_proc_init();
 124         if (err)
 125                 printk(KERN_INFO "%s: can't create entry in proc filesystem!\n",
 126                        wanrouter_modname);
 127
 128         return err;
 129 }
 130
 131 static void __exit wanrouter_cleanup (void)
 132 {
 133         wanrouter_proc_cleanup();
 134 }
 135
 136 /*
 137  * This is just plain dumb.  We should move the bugger to drivers/net/wan,
 138  * slap it first in directory and make it module_init().  The only reason
 139  * for subsys_initcall() here is that net goes after drivers (why, BTW?)
 140  */
 141 subsys_initcall(wanrouter_init);
 142 module_exit(wanrouter_cleanup);
 143
 144 /*
 145  *      Kernel APIs
 146  */
 147
 148 /*
 149  *      Register WAN device.
 150  *      o verify device credentials
 151  *      o create an entry for the device in the /proc/net/router directory
 152  *      o initialize internally maintained fields of the wan_device structure
 153  *      o link device data space to a singly-linked list
 154  *      o if it's the first device, then start kernel 'thread'
 155  *      o increment module use count
 156  *
 157  *      Return:
 158  *      0       Ok
 159  *      < 0     error.
 160  *
 161  *      Context:        process
 162  */
 163
 164
 165 int register_wan_device(struct wan_device *wandev)
 166 {
 167         int err, namelen;
 168
 169         if ((wandev == NULL) || (wandev->magic != ROUTER_MAGIC) ||
 170             (wandev->name == NULL))
 171                 return -EINVAL;
 172
 173         namelen = strlen(wandev->name);
 174         if (!namelen || (namelen > WAN_DRVNAME_SZ))
 175                 return -EINVAL;
 176
 177         if (wanrouter_find_device(wandev->name))
 178                 return -EEXIST;
 179
 180 #ifdef WANDEBUG
 181         printk(KERN_INFO "%s: registering WAN device %s\n",
 182                wanrouter_modname, wandev->name);
 183 #endif
 184
 185         /*
 186          *      Register /proc directory entry
 187          */
 188         err = wanrouter_proc_add(wandev);
 189         if (err) {
 190                 printk(KERN_INFO
 191                         "%s: can't create /proc/net/router/%s entry!\n",
 192                         wanrouter_modname, wandev->name);
 193                 return err;
 194         }
 195
 196         /*
 197          *      Initialize fields of the wan_device structure maintained by the
 198          *      router and update local data.
 199          */
 200
 201         wandev->ndev = 0;
 202         wandev->dev  = NULL;
 203         wandev->next = wanrouter_router_devlist;
 204         wanrouter_router_devlist = wandev;
 205         return 0;
 206 }
 207
 208 /*
 209  *      Unregister WAN device.
 210  *      o shut down device
 211  *      o unlink device data space from the linked list
 212  *      o delete device entry in the /proc/net/router directory
 213  *      o decrement module use count
 214  *
 215  *      Return:         0       Ok
 216  *                      <0      error.
 217  *      Context:        process
 218  */
 219
 220
 221 int unregister_wan_device(char *name)
 222 {
 223         struct wan_device *wandev, *prev;
 224
 225         if (name == NULL)
 226                 return -EINVAL;
 227
 228         for (wandev = wanrouter_router_devlist, prev = NULL;
 229                 wandev && strcmp(wandev->name, name);
 230                 prev = wandev, wandev = wandev->next)
 231                 ;
 232         if (wandev == NULL)
 233                 return -ENODEV;
 234
 235 #ifdef WANDEBUG
 236         printk(KERN_INFO "%s: unregistering WAN device %s\n",
 237                wanrouter_modname, name);
 238 #endif
 239
 240         if (wandev->state != WAN_UNCONFIGURED)
 241                 wanrouter_device_shutdown(wandev);
 242
 243         if (prev)
 244                 prev->next = wandev->next;
 245         else
 246                 wanrouter_router_devlist = wandev->next;
 247
 248         wanrouter_proc_delete(wandev);
 249         return 0;
 250 }
 251
 252 #if 0
 253
 254 /*
 255  *      Encapsulate packet.
 256  *
 257  *      Return: encapsulation header size
 258  *              < 0     - unsupported Ethertype
 259  *
 260  *      Notes:
 261  *      1. This function may be called on interrupt context.
 262  */
 263
 264
 265 int wanrouter_encapsulate(struct sk_buff *skb, struct net_device *dev,
 266                           unsigned short type)
 267 {
 268         int hdr_len = 0;
 269
 270         switch (type) {
 271         case ETH_P_IP:          /* IP datagram encapsulation */
 272                 hdr_len += 1;
 273                 skb_push(skb, 1);
 274                 skb->data[0] = NLPID_IP;
 275                 break;
 276
 277         case ETH_P_IPX:         /* SNAP encapsulation */
 278         case ETH_P_ARP:
 279                 hdr_len += 7;
 280                 skb_push(skb, 7);
 281                 skb->data[0] = 0;
 282                 skb->data[1] = NLPID_SNAP;
 283                 skb_copy_to_linear_data_offset(skb, 2, wanrouter_oui_ether,
 284                                                sizeof(wanrouter_oui_ether));
 285                 *((unsigned short*)&skb->data[5]) = htons(type);
 286                 break;
 287
 288         default:                /* Unknown packet type */
 289                 printk(KERN_INFO
 290                         "%s: unsupported Ethertype 0x%04X on interface %s!\n",
 291                         wanrouter_modname, type, dev->name);
 292                 hdr_len = -EINVAL;
 293         }
 294         return hdr_len;
 295 }
 296
 297
 298 /*
 299  *      Decapsulate packet.
 300  *
 301  *      Return: Ethertype (in network order)
 302  *                      0       unknown encapsulation
 303  *
 304  *      Notes:
 305  *      1. This function may be called on interrupt context.
 306  */
 307
 308
 309 __be16 wanrouter_type_trans(struct sk_buff *skb, struct net_device *dev)
 310 {
 311         int cnt = skb->data[0] ? 0 : 1; /* there may be a pad present */
 312         __be16 ethertype;
 313
 314         switch (skb->data[cnt]) {
 315         case NLPID_IP:          /* IP datagramm */
 316                 ethertype = htons(ETH_P_IP);
 317                 cnt += 1;
 318                 break;
 319
 320         case NLPID_SNAP:        /* SNAP encapsulation */
 321                 if (memcmp(&skb->data[cnt + 1], wanrouter_oui_ether,
 322                            sizeof(wanrouter_oui_ether))){
 323                         printk(KERN_INFO
 324                                 "%s: unsupported SNAP OUI %02X-%02X-%02X "
 325                                 "on interface %s!\n", wanrouter_modname,
 326                                 skb->data[cnt+1], skb->data[cnt+2],
 327                                 skb->data[cnt+3], dev->name);
 328                         return 0;
 329                 }
 330                 ethertype = *((__be16*)&skb->data[cnt+4]);
 331                 cnt += 6;
 332                 break;
 333
 334         /* add other protocols, e.g. CLNP, ESIS, ISIS, if needed */
 335
 336         default:
 337                 printk(KERN_INFO
 338                         "%s: unsupported NLPID 0x%02X on interface %s!\n",
 339                         wanrouter_modname, skb->data[cnt], dev->name);
 340                 return 0;
 341         }
 342         skb->protocol = ethertype;
 343         skb->pkt_type = PACKET_HOST;    /*      Physically point to point */
 344         skb_pull(skb, cnt);
 345         skb_reset_mac_header(skb);
 346         return ethertype;
 347 }
 348
 349 #endif  /*  0  */
 350
 351 /*
 352  *      WAN device IOCTL.
 353  *      o find WAN device associated with this node
 354  *      o execute requested action or pass command to the device driver
 355  */
 356
 357 long wanrouter_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 358 {
 359         struct inode *inode = file->f_path.dentry->d_inode;
 360         int err = 0;
 361         struct proc_dir_entry *dent;
 362         struct wan_device *wandev;
 363         void __user *data = (void __user *)arg;
 364
 365         if (!capable(CAP_NET_ADMIN))
 366                 return -EPERM;
 367
 368         if ((cmd >> 8) != ROUTER_IOCTL)
 369                 return -EINVAL;
 370
 371         dent = PDE(inode);
 372         if ((dent == NULL) || (dent->data == NULL))
 373                 return -EINVAL;
 374
 375         wandev = dent->data;
 376         if (wandev->magic != ROUTER_MAGIC)
 377                 return -EINVAL;
 378
 379         lock_kernel();
 380         switch (cmd) {
 381         case ROUTER_SETUP:
 382                 err = wanrouter_device_setup(wandev, data);
 383                 break;
 384
 385         case ROUTER_DOWN:
 386                 err = wanrouter_device_shutdown(wandev);
 387                 break;
 388
 389         case ROUTER_STAT:
 390                 err = wanrouter_device_stat(wandev, data);
 391                 break;
 392
 393         case ROUTER_IFNEW:
 394                 err = wanrouter_device_new_if(wandev, data);
 395                 break;
 396
 397         case ROUTER_IFDEL:
 398                 err = wanrouter_device_del_if(wandev, data);
 399                 break;
 400
 401         case ROUTER_IFSTAT:
 402                 break;
 403
 404         default:
 405                 if ((cmd >= ROUTER_USER) &&
 406                     (cmd <= ROUTER_USER_MAX) &&
 407                     wandev->ioctl)
 408                         err = wandev->ioctl(wandev, cmd, arg);
 409                 else err = -EINVAL;
 410         }
 411         unlock_kernel();
 412         return err;
 413 }
 414
 415 /*
 416  *      WAN Driver IOCTL Handlers
 417  */
 418
 419 /*
 420  *      Setup WAN link device.
 421  *      o verify user address space
 422  *      o allocate kernel memory and copy configuration data to kernel space
 423  *      o if configuration data includes extension, copy it to kernel space too
 424  *      o call driver's setup() entry point
 425  */
 426
 427 static int wanrouter_device_setup(struct wan_device *wandev,
 428                                   wandev_conf_t __user *u_conf)
 429 {
 430         void *data = NULL;
 431         wandev_conf_t *conf;
 432         int err = -EINVAL;
 433
 434         if (wandev->setup == NULL) {    /* Nothing to do ? */
 435                 printk(KERN_INFO "%s: ERROR, No setup script: wandev->setup()\n",
 436                                 wandev->name);
 437                 return 0;
 438         }
 439
 440         conf = kmalloc(sizeof(wandev_conf_t), GFP_KERNEL);
 441         if (conf == NULL){
 442                 printk(KERN_INFO "%s: ERROR, Failed to allocate kernel memory !\n",
 443                                 wandev->name);
 444                 return -ENOBUFS;
 445         }
 446
 447         if (copy_from_user(conf, u_conf, sizeof(wandev_conf_t))) {
 448                 printk(KERN_INFO "%s: Failed to copy user config data to kernel space!\n",
 449                                 wandev->name);
 450                 kfree(conf);
 451                 return -EFAULT;
 452         }
 453
 454         if (conf->magic != ROUTER_MAGIC) {
 455                 kfree(conf);
 456                 printk(KERN_INFO "%s: ERROR, Invalid MAGIC Number\n",
 457                                 wandev->name);
 458                 return -EINVAL;
 459         }
 460
 461         if (conf->data_size && conf->data) {
 462                 if (conf->data_size > 128000) {
 463                         printk(KERN_INFO
 464                             "%s: ERROR, Invalid firmware data size %i !\n",
 465                                         wandev->name, conf->data_size);
 466                         kfree(conf);
 467                         return -EINVAL;
 468                 }
 469
 470                 data = vmalloc(conf->data_size);
 471                 if (!data) {
 472                         printk(KERN_INFO
 473                                 "%s: ERROR, Faild allocate kernel memory !\n",
 474                                 wandev->name);
 475                         kfree(conf);
 476                         return -ENOBUFS;
 477                 }
 478                 if (!copy_from_user(data, conf->data, conf->data_size)) {
 479                         conf->data = data;
 480                         err = wandev->setup(wandev, conf);
 481                 } else {
 482                         printk(KERN_INFO
 483                              "%s: ERROR, Faild to copy from user data !\n",
 484                                wandev->name);
 485                         err = -EFAULT;
 486                 }
 487                 vfree(data);
 488         } else {
 489                 printk(KERN_INFO
 490                     "%s: ERROR, No firmware found ! Firmware size = %i !\n",
 491                                 wandev->name, conf->data_size);
 492         }
 493
 494         kfree(conf);
 495         return err;
 496 }
 497
 498 /*
 499  *      Shutdown WAN device.
 500  *      o delete all not opened logical channels for this device
 501  *      o call driver's shutdown() entry point
 502  */
 503
 504 static int wanrouter_device_shutdown(struct wan_device *wandev)
 505 {
 506         struct net_device *dev;
 507         int err=0;
 508
 509         if (wandev->state == WAN_UNCONFIGURED)
 510                 return 0;
 511
 512         printk(KERN_INFO "\n%s: Shutting Down!\n",wandev->name);
 513
 514         for (dev = wandev->dev; dev;) {
 515                 err = wanrouter_delete_interface(wandev, dev->name);
 516                 if (err)
 517                         return err;
 518                 /* The above function deallocates the current dev
 519                  * structure. Therefore, we cannot use netdev_priv(dev)
 520                  * as the next element: wandev->dev points to the
 521                  * next element */
 522                 dev = wandev->dev;
 523         }
 524
 525         if (wandev->ndev)
 526                 return -EBUSY;  /* there are opened interfaces  */
 527
 528         if (wandev->shutdown)
 529                 err=wandev->shutdown(wandev);
 530
 531         return err;
 532 }
 533
 534 /*
 535  *      Get WAN device status & statistics.
 536  */
 537
 538 static int wanrouter_device_stat(struct wan_device *wandev,
 539                                  wandev_stat_t __user *u_stat)
 540 {
 541         wandev_stat_t stat;
 542
 543         memset(&stat, 0, sizeof(stat));
 544
 545         /* Ask device driver to update device statistics */
 546         if ((wandev->state != WAN_UNCONFIGURED) && wandev->update)
 547                 wandev->update(wandev);
 548
 549         /* Fill out structure */
 550         stat.ndev  = wandev->ndev;
 551         stat.state = wandev->state;
 552
 553         if (copy_to_user(u_stat, &stat, sizeof(stat)))
 554                 return -EFAULT;
 555
 556         return 0;
 557 }
 558
 559 /*
 560  *      Create new WAN interface.
 561  *      o verify user address space
 562  *      o copy configuration data to kernel address space
 563  *      o allocate network interface data space
 564  *      o call driver's new_if() entry point
 565  *      o make sure there is no interface name conflict
 566  *      o register network interface
 567  */
 568
 569 static int wanrouter_device_new_if(struct wan_device *wandev,
 570                                    wanif_conf_t __user *u_conf)
 571 {
 572         wanif_conf_t *cnf;
 573         struct net_device *dev = NULL;
 574         int err;
 575
 576         if ((wandev->state == WAN_UNCONFIGURED) || (wandev->new_if == NULL))
 577                 return -ENODEV;
 578
 579         cnf = kmalloc(sizeof(wanif_conf_t), GFP_KERNEL);
 580         if (!cnf)
 581                 return -ENOBUFS;
 582
 583         err = -EFAULT;
 584         if (copy_from_user(cnf, u_conf, sizeof(wanif_conf_t)))
 585                 goto out;
 586
 587         err = -EINVAL;
 588         if (cnf->magic != ROUTER_MAGIC)
 589                 goto out;
 590
 591         if (cnf->config_id == WANCONFIG_MPPP) {
 592                 printk(KERN_INFO "%s: Wanpipe Mulit-Port PPP support has not been compiled in!\n",
 593                                 wandev->name);
 594                 err = -EPROTONOSUPPORT;
 595                 goto out;
 596         } else {
 597                 err = wandev->new_if(wandev, dev, cnf);
 598         }
 599
 600         if (!err) {
 601                 /* Register network interface. This will invoke init()
 602                  * function supplied by the driver.  If device registered
 603                  * successfully, add it to the interface list.
 604                  */
 605
 606                 if (dev->name == NULL) {
 607                         err = -EINVAL;
 608                 } else {
 609
 610                         #ifdef WANDEBUG
 611                         printk(KERN_INFO "%s: registering interface %s...\n",
 612                                 wanrouter_modname, dev->name);
 613                         #endif
 614
 615                         err = register_netdev(dev);
 616                         if (!err) {
 617                                 struct net_device *slave = NULL;
 618                                 unsigned long smp_flags=0;
 619
 620                                 lock_adapter_irq(&wandev->lock, &smp_flags);
 621
 622                                 if (wandev->dev == NULL) {
 623                                         wandev->dev = dev;
 624                                 } else {
 625                                         for (slave=wandev->dev;
 626                                              DEV_TO_SLAVE(slave);
 627                                              slave = DEV_TO_SLAVE(slave))
 628                                                 DEV_TO_SLAVE(slave) = dev;
 629                                 }
 630                                 ++wandev->ndev;
 631
 632                                 unlock_adapter_irq(&wandev->lock, &smp_flags);
 633                                 err = 0;        /* done !!! */
 634                                 goto out;
 635                         }
 636                 }
 637                 if (wandev->del_if)
 638                         wandev->del_if(wandev, dev);
 639                 free_netdev(dev);
 640         }
 641
 642 out:
 643         kfree(cnf);
 644         return err;
 645 }
 646
 647
 648 /*
 649  *      Delete WAN logical channel.
 650  *       o verify user address space
 651  *       o copy configuration data to kernel address space
 652  */
 653
 654 static int wanrouter_device_del_if(struct wan_device *wandev, char __user *u_name)
 655 {
 656         char name[WAN_IFNAME_SZ + 1];
 657         int err = 0;
 658
 659         if (wandev->state == WAN_UNCONFIGURED)
 660                 return -ENODEV;
 661
 662         memset(name, 0, sizeof(name));
 663
 664         if (copy_from_user(name, u_name, WAN_IFNAME_SZ))
 665                 return -EFAULT;
 666
 667         err = wanrouter_delete_interface(wandev, name);
 668         if (err)
 669                 return err;
 670
 671         /* If last interface being deleted, shutdown card
 672          * This helps with administration at leaf nodes
 673          * (You can tell if the person at the other end of the phone
 674          * has an interface configured) and avoids DoS vulnerabilities
 675          * in binary driver files - this fixes a problem with the current
 676          * Sangoma driver going into strange states when all the network
 677          * interfaces are deleted and the link irrecoverably disconnected.
 678          */
 679
 680         if (!wandev->ndev && wandev->shutdown)
 681                 err = wandev->shutdown(wandev);
 682
 683         return err;
 684 }
 685
 686 /*
 687  *      Miscellaneous Functions
 688  */
 689
 690 /*
 691  *      Find WAN device by name.
 692  *      Return pointer to the WAN device data space or NULL if device not found.
 693  */
 694
 695 static struct wan_device *wanrouter_find_device(char *name)
 696 {
 697         struct wan_device *wandev;
 698
 699         for (wandev = wanrouter_router_devlist;
 700              wandev && strcmp(wandev->name, name);
 701                 wandev = wandev->next);
 702         return wandev;
 703 }
 704
 705 /*
 706  *      Delete WAN logical channel identified by its name.
 707  *      o find logical channel by its name
 708  *      o call driver's del_if() entry point
 709  *      o unregister network interface
 710  *      o unlink channel data space from linked list of channels
 711  *      o release channel data space
 712  *
 713  *      Return: 0               success
 714  *              -ENODEV         channel not found.
 715  *              -EBUSY          interface is open
 716  *
 717  *      Note: If (force != 0), then device will be destroyed even if interface
 718  *      associated with it is open. It's caller's responsibility to make
 719  *      sure that opened interfaces are not removed!
 720  */
 721
 722 static int wanrouter_delete_interface(struct wan_device *wandev, char *name)
 723 {
 724         struct net_device *dev = NULL, *prev = NULL;
 725         unsigned long smp_flags=0;
 726
 727         lock_adapter_irq(&wandev->lock, &smp_flags);
 728         dev = wandev->dev;
 729         prev = NULL;
 730         while (dev && strcmp(name, dev->name)) {
 731                 struct net_device **slave = netdev_priv(dev);
 732                 prev = dev;
 733                 dev = *slave;
 734         }
 735         unlock_adapter_irq(&wandev->lock, &smp_flags);
 736
 737         if (dev == NULL)
 738                 return -ENODEV; /* interface not found */
 739
 740         if (netif_running(dev))
 741                 return -EBUSY;  /* interface in use */
 742
 743         if (wandev->del_if)
 744                 wandev->del_if(wandev, dev);
 745
 746         lock_adapter_irq(&wandev->lock, &smp_flags);
 747         if (prev) {
 748                 struct net_device **prev_slave = netdev_priv(prev);
 749                 struct net_device **slave = netdev_priv(dev);
 750
 751                 *prev_slave = *slave;
 752         } else {
 753                 struct net_device **slave = netdev_priv(dev);
 754                 wandev->dev = *slave;
 755         }
 756         --wandev->ndev;
 757         unlock_adapter_irq(&wandev->lock, &smp_flags);
 758
 759         printk(KERN_INFO "%s: unregistering '%s'\n", wandev->name, dev->name);
 760
 761         unregister_netdev(dev);
 762
 763         free_netdev(dev);
 764
 765         return 0;
 766 }
 767
 768 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
 769         __acquires(lock)
 770 {
 771         spin_lock_irqsave(lock, *smp_flags);
 772 }
 773
 774
 775 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
 776         __releases(lock)
 777 {
 778         spin_unlock_irqrestore(lock, *smp_flags);
 779 }
 780
 781 EXPORT_SYMBOL(register_wan_device);
 782 EXPORT_SYMBOL(unregister_wan_device);
 783
 784 MODULE_LICENSE("GPL");
 785
 786 /*
 787  *      End
 788  */