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/mutex.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 DEFINE_MUTEX(wanrouter_mutex);
  75 static int wanrouter_device_setup(struct wan_device *wandev,
  76                                   wandev_conf_t __user *u_conf);
  77 static int wanrouter_device_stat(struct wan_device *wandev,
  78                                  wandev_stat_t __user *u_stat);
  79 static int wanrouter_device_shutdown(struct wan_device *wandev);
  80 static int wanrouter_device_new_if(struct wan_device *wandev,
  81                                    wanif_conf_t __user *u_conf);
  82 static int wanrouter_device_del_if(struct wan_device *wandev,
  83                                    char __user *u_name);
  84
  85 /*
  86  *      Miscellaneous
  87  */
  88
  89 static struct wan_device *wanrouter_find_device(char *name);
  90 static int wanrouter_delete_interface(struct wan_device *wandev, char *name);
  91 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
  92         __acquires(lock);
  93 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
  94         __releases(lock);
  95
  96
  97
  98 /*
  99  *      Global Data
 100  */
 101
 102 static char wanrouter_fullname[]  = "Sangoma WANPIPE Router";
 103 static char wanrouter_copyright[] = "(c) 1995-2000 Sangoma Technologies Inc.";
 104 static char wanrouter_modname[] = ROUTER_NAME; /* short module name */
 105 struct wan_device* wanrouter_router_devlist; /* list of registered devices */
 106
 107 /*
 108  *      Organize Unique Identifiers for encapsulation/decapsulation
 109  */
 110
 111 #if 0
 112 static unsigned char wanrouter_oui_ether[] = { 0x00, 0x00, 0x00 };
 113 static unsigned char wanrouter_oui_802_2[] = { 0x00, 0x80, 0xC2 };
 114 #endif
 115
 116 static int __init wanrouter_init(void)
 117 {
 118         int err;
 119
 120         printk(KERN_INFO "%s v%u.%u %s\n",
 121                wanrouter_fullname, ROUTER_VERSION, ROUTER_RELEASE,
 122                wanrouter_copyright);
 123
 124         err = wanrouter_proc_init();
 125         if (err)
 126                 printk(KERN_INFO "%s: can't create entry in proc filesystem!\n",
 127                        wanrouter_modname);
 128
 129         return err;
 130 }
 131
 132 static void __exit wanrouter_cleanup (void)
 133 {
 134         wanrouter_proc_cleanup();
 135 }
 136
 137 /*
 138  * This is just plain dumb.  We should move the bugger to drivers/net/wan,
 139  * slap it first in directory and make it module_init().  The only reason
 140  * for subsys_initcall() here is that net goes after drivers (why, BTW?)
 141  */
 142 subsys_initcall(wanrouter_init);
 143 module_exit(wanrouter_cleanup);
 144
 145 /*
 146  *      Kernel APIs
 147  */
 148
 149 /*
 150  *      Register WAN device.
 151  *      o verify device credentials
 152  *      o create an entry for the device in the /proc/net/router directory
 153  *      o initialize internally maintained fields of the wan_device structure
 154  *      o link device data space to a singly-linked list
 155  *      o if it's the first device, then start kernel 'thread'
 156  *      o increment module use count
 157  *
 158  *      Return:
 159  *      0       Ok
 160  *      < 0     error.
 161  *
 162  *      Context:        process
 163  */
 164
 165
 166 int register_wan_device(struct wan_device *wandev)
 167 {
 168         int err, namelen;
 169
 170         if ((wandev == NULL) || (wandev->magic != ROUTER_MAGIC) ||
 171             (wandev->name == NULL))
 172                 return -EINVAL;
 173
 174         namelen = strlen(wandev->name);
 175         if (!namelen || (namelen > WAN_DRVNAME_SZ))
 176                 return -EINVAL;
 177
 178         if (wanrouter_find_device(wandev->name))
 179                 return -EEXIST;
 180
 181 #ifdef WANDEBUG
 182         printk(KERN_INFO "%s: registering WAN device %s\n",
 183                wanrouter_modname, wandev->name);
 184 #endif
 185
 186         /*
 187          *      Register /proc directory entry
 188          */
 189         err = wanrouter_proc_add(wandev);
 190         if (err) {
 191                 printk(KERN_INFO
 192                         "%s: can't create /proc/net/router/%s entry!\n",
 193                         wanrouter_modname, wandev->name);
 194                 return err;
 195         }
 196
 197         /*
 198          *      Initialize fields of the wan_device structure maintained by the
 199          *      router and update local data.
 200          */
 201
 202         wandev->ndev = 0;
 203         wandev->dev  = NULL;
 204         wandev->next = wanrouter_router_devlist;
 205         wanrouter_router_devlist = wandev;
 206         return 0;
 207 }
 208
 209 /*
 210  *      Unregister WAN device.
 211  *      o shut down device
 212  *      o unlink device data space from the linked list
 213  *      o delete device entry in the /proc/net/router directory
 214  *      o decrement module use count
 215  *
 216  *      Return:         0       Ok
 217  *                      <0      error.
 218  *      Context:        process
 219  */
 220
 221
 222 int unregister_wan_device(char *name)
 223 {
 224         struct wan_device *wandev, *prev;
 225
 226         if (name == NULL)
 227                 return -EINVAL;
 228
 229         for (wandev = wanrouter_router_devlist, prev = NULL;
 230                 wandev && strcmp(wandev->name, name);
 231                 prev = wandev, wandev = wandev->next)
 232                 ;
 233         if (wandev == NULL)
 234                 return -ENODEV;
 235
 236 #ifdef WANDEBUG
 237         printk(KERN_INFO "%s: unregistering WAN device %s\n",
 238                wanrouter_modname, name);
 239 #endif
 240
 241         if (wandev->state != WAN_UNCONFIGURED)
 242                 wanrouter_device_shutdown(wandev);
 243
 244         if (prev)
 245                 prev->next = wandev->next;
 246         else
 247                 wanrouter_router_devlist = wandev->next;
 248
 249         wanrouter_proc_delete(wandev);
 250         return 0;
 251 }
 252
 253 #if 0
 254
 255 /*
 256  *      Encapsulate packet.
 257  *
 258  *      Return: encapsulation header size
 259  *              < 0     - unsupported Ethertype
 260  *
 261  *      Notes:
 262  *      1. This function may be called on interrupt context.
 263  */
 264
 265
 266 int wanrouter_encapsulate(struct sk_buff *skb, struct net_device *dev,
 267                           unsigned short type)
 268 {
 269         int hdr_len = 0;
 270
 271         switch (type) {
 272         case ETH_P_IP:          /* IP datagram encapsulation */
 273                 hdr_len += 1;
 274                 skb_push(skb, 1);
 275                 skb->data[0] = NLPID_IP;
 276                 break;
 277
 278         case ETH_P_IPX:         /* SNAP encapsulation */
 279         case ETH_P_ARP:
 280                 hdr_len += 7;
 281                 skb_push(skb, 7);
 282                 skb->data[0] = 0;
 283                 skb->data[1] = NLPID_SNAP;
 284                 skb_copy_to_linear_data_offset(skb, 2, wanrouter_oui_ether,
 285                                                sizeof(wanrouter_oui_ether));
 286                 *((unsigned short*)&skb->data[5]) = htons(type);
 287                 break;
 288
 289         default:                /* Unknown packet type */
 290                 printk(KERN_INFO
 291                         "%s: unsupported Ethertype 0x%04X on interface %s!\n",
 292                         wanrouter_modname, type, dev->name);
 293                 hdr_len = -EINVAL;
 294         }
 295         return hdr_len;
 296 }
 297
 298
 299 /*
 300  *      Decapsulate packet.
 301  *
 302  *      Return: Ethertype (in network order)
 303  *                      0       unknown encapsulation
 304  *
 305  *      Notes:
 306  *      1. This function may be called on interrupt context.
 307  */
 308
 309
 310 __be16 wanrouter_type_trans(struct sk_buff *skb, struct net_device *dev)
 311 {
 312         int cnt = skb->data[0] ? 0 : 1; /* there may be a pad present */
 313         __be16 ethertype;
 314
 315         switch (skb->data[cnt]) {
 316         case NLPID_IP:          /* IP datagramm */
 317                 ethertype = htons(ETH_P_IP);
 318                 cnt += 1;
 319                 break;
 320
 321         case NLPID_SNAP:        /* SNAP encapsulation */
 322                 if (memcmp(&skb->data[cnt + 1], wanrouter_oui_ether,
 323                            sizeof(wanrouter_oui_ether))){
 324                         printk(KERN_INFO
 325                                 "%s: unsupported SNAP OUI %02X-%02X-%02X "
 326                                 "on interface %s!\n", wanrouter_modname,
 327                                 skb->data[cnt+1], skb->data[cnt+2],
 328                                 skb->data[cnt+3], dev->name);
 329                         return 0;
 330                 }
 331                 ethertype = *((__be16*)&skb->data[cnt+4]);
 332                 cnt += 6;
 333                 break;
 334
 335         /* add other protocols, e.g. CLNP, ESIS, ISIS, if needed */
 336
 337         default:
 338                 printk(KERN_INFO
 339                         "%s: unsupported NLPID 0x%02X on interface %s!\n",
 340                         wanrouter_modname, skb->data[cnt], dev->name);
 341                 return 0;
 342         }
 343         skb->protocol = ethertype;
 344         skb->pkt_type = PACKET_HOST;    /*      Physically point to point */
 345         skb_pull(skb, cnt);
 346         skb_reset_mac_header(skb);
 347         return ethertype;
 348 }
 349
 350 #endif  /*  0  */
 351
 352 /*
 353  *      WAN device IOCTL.
 354  *      o find WAN device associated with this node
 355  *      o execute requested action or pass command to the device driver
 356  */
 357
 358 long wanrouter_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 359 {
 360         struct inode *inode = file->f_path.dentry->d_inode;
 361         int err = 0;
 362         struct proc_dir_entry *dent;
 363         struct wan_device *wandev;
 364         void __user *data = (void __user *)arg;
 365
 366         if (!capable(CAP_NET_ADMIN))
 367                 return -EPERM;
 368
 369         if ((cmd >> 8) != ROUTER_IOCTL)
 370                 return -EINVAL;
 371
 372         dent = PDE(inode);
 373         if ((dent == NULL) || (dent->data == NULL))
 374                 return -EINVAL;
 375
 376         wandev = dent->data;
 377         if (wandev->magic != ROUTER_MAGIC)
 378                 return -EINVAL;
 379
 380         mutex_lock(&wanrouter_mutex);
 381         switch (cmd) {
 382         case ROUTER_SETUP:
 383                 err = wanrouter_device_setup(wandev, data);
 384                 break;
 385
 386         case ROUTER_DOWN:
 387                 err = wanrouter_device_shutdown(wandev);
 388                 break;
 389
 390         case ROUTER_STAT:
 391                 err = wanrouter_device_stat(wandev, data);
 392                 break;
 393
 394         case ROUTER_IFNEW:
 395                 err = wanrouter_device_new_if(wandev, data);
 396                 break;
 397
 398         case ROUTER_IFDEL:
 399                 err = wanrouter_device_del_if(wandev, data);
 400                 break;
 401
 402         case ROUTER_IFSTAT:
 403                 break;
 404
 405         default:
 406                 if ((cmd >= ROUTER_USER) &&
 407                     (cmd <= ROUTER_USER_MAX) &&
 408                     wandev->ioctl)
 409                         err = wandev->ioctl(wandev, cmd, arg);
 410                 else err = -EINVAL;
 411         }
 412         mutex_unlock(&wanrouter_mutex);
 413         return err;
 414 }
 415
 416 /*
 417  *      WAN Driver IOCTL Handlers
 418  */
 419
 420 /*
 421  *      Setup WAN link device.
 422  *      o verify user address space
 423  *      o allocate kernel memory and copy configuration data to kernel space
 424  *      o if configuration data includes extension, copy it to kernel space too
 425  *      o call driver's setup() entry point
 426  */
 427
 428 static int wanrouter_device_setup(struct wan_device *wandev,
 429                                   wandev_conf_t __user *u_conf)
 430 {
 431         void *data = NULL;
 432         wandev_conf_t *conf;
 433         int err = -EINVAL;
 434
 435         if (wandev->setup == NULL) {    /* Nothing to do ? */
 436                 printk(KERN_INFO "%s: ERROR, No setup script: wandev->setup()\n",
 437                                 wandev->name);
 438                 return 0;
 439         }
 440
 441         conf = kmalloc(sizeof(wandev_conf_t), GFP_KERNEL);
 442         if (conf == NULL){
 443                 printk(KERN_INFO "%s: ERROR, Failed to allocate kernel memory !\n",
 444                                 wandev->name);
 445                 return -ENOBUFS;
 446         }
 447
 448         if (copy_from_user(conf, u_conf, sizeof(wandev_conf_t))) {
 449                 printk(KERN_INFO "%s: Failed to copy user config data to kernel space!\n",
 450                                 wandev->name);
 451                 kfree(conf);
 452                 return -EFAULT;
 453         }
 454
 455         if (conf->magic != ROUTER_MAGIC) {
 456                 kfree(conf);
 457                 printk(KERN_INFO "%s: ERROR, Invalid MAGIC Number\n",
 458                                 wandev->name);
 459                 return -EINVAL;
 460         }
 461
 462         if (conf->data_size && conf->data) {
 463                 if (conf->data_size > 128000) {
 464                         printk(KERN_INFO
 465                             "%s: ERROR, Invalid firmware data size %i !\n",
 466                                         wandev->name, conf->data_size);
 467                         kfree(conf);
 468                         return -EINVAL;
 469                 }
 470
 471                 data = vmalloc(conf->data_size);
 472                 if (!data) {
 473                         printk(KERN_INFO
 474                                 "%s: ERROR, Failed allocate kernel memory !\n",
 475                                 wandev->name);
 476                         kfree(conf);
 477                         return -ENOBUFS;
 478                 }
 479                 if (!copy_from_user(data, conf->data, conf->data_size)) {
 480                         conf->data = data;
 481                         err = wandev->setup(wandev, conf);
 482                 } else {
 483                         printk(KERN_INFO
 484                              "%s: ERROR, Failed to copy from user data !\n",
 485                                wandev->name);
 486                         err = -EFAULT;
 487                 }
 488                 vfree(data);
 489         } else {
 490                 printk(KERN_INFO
 491                     "%s: ERROR, No firmware found ! Firmware size = %i !\n",
 492                                 wandev->name, conf->data_size);
 493         }
 494
 495         kfree(conf);
 496         return err;
 497 }
 498
 499 /*
 500  *      Shutdown WAN device.
 501  *      o delete all not opened logical channels for this device
 502  *      o call driver's shutdown() entry point
 503  */
 504
 505 static int wanrouter_device_shutdown(struct wan_device *wandev)
 506 {
 507         struct net_device *dev;
 508         int err=0;
 509
 510         if (wandev->state == WAN_UNCONFIGURED)
 511                 return 0;
 512
 513         printk(KERN_INFO "\n%s: Shutting Down!\n",wandev->name);
 514
 515         for (dev = wandev->dev; dev;) {
 516                 err = wanrouter_delete_interface(wandev, dev->name);
 517                 if (err)
 518                         return err;
 519                 /* The above function deallocates the current dev
 520                  * structure. Therefore, we cannot use netdev_priv(dev)
 521                  * as the next element: wandev->dev points to the
 522                  * next element */
 523                 dev = wandev->dev;
 524         }
 525
 526         if (wandev->ndev)
 527                 return -EBUSY;  /* there are opened interfaces  */
 528
 529         if (wandev->shutdown)
 530                 err=wandev->shutdown(wandev);
 531
 532         return err;
 533 }
 534
 535 /*
 536  *      Get WAN device status & statistics.
 537  */
 538
 539 static int wanrouter_device_stat(struct wan_device *wandev,
 540                                  wandev_stat_t __user *u_stat)
 541 {
 542         wandev_stat_t stat;
 543
 544         memset(&stat, 0, sizeof(stat));
 545
 546         /* Ask device driver to update device statistics */
 547         if ((wandev->state != WAN_UNCONFIGURED) && wandev->update)
 548                 wandev->update(wandev);
 549
 550         /* Fill out structure */
 551         stat.ndev  = wandev->ndev;
 552         stat.state = wandev->state;
 553
 554         if (copy_to_user(u_stat, &stat, sizeof(stat)))
 555                 return -EFAULT;
 556
 557         return 0;
 558 }
 559
 560 /*
 561  *      Create new WAN interface.
 562  *      o verify user address space
 563  *      o copy configuration data to kernel address space
 564  *      o allocate network interface data space
 565  *      o call driver's new_if() entry point
 566  *      o make sure there is no interface name conflict
 567  *      o register network interface
 568  */
 569
 570 static int wanrouter_device_new_if(struct wan_device *wandev,
 571                                    wanif_conf_t __user *u_conf)
 572 {
 573         wanif_conf_t *cnf;
 574         struct net_device *dev = NULL;
 575         int err;
 576
 577         if ((wandev->state == WAN_UNCONFIGURED) || (wandev->new_if == NULL))
 578                 return -ENODEV;
 579
 580         cnf = kmalloc(sizeof(wanif_conf_t), GFP_KERNEL);
 581         if (!cnf)
 582                 return -ENOBUFS;
 583
 584         err = -EFAULT;
 585         if (copy_from_user(cnf, u_conf, sizeof(wanif_conf_t)))
 586                 goto out;
 587
 588         err = -EINVAL;
 589         if (cnf->magic != ROUTER_MAGIC)
 590                 goto out;
 591
 592         if (cnf->config_id == WANCONFIG_MPPP) {
 593                 printk(KERN_INFO "%s: Wanpipe Mulit-Port PPP support has not been compiled in!\n",
 594                                 wandev->name);
 595                 err = -EPROTONOSUPPORT;
 596                 goto out;
 597         } else {
 598                 err = wandev->new_if(wandev, dev, cnf);
 599         }
 600
 601         if (!err) {
 602                 /* Register network interface. This will invoke init()
 603                  * function supplied by the driver.  If device registered
 604                  * successfully, add it to the interface list.
 605                  */
 606
 607                 if (dev->name == NULL) {
 608                         err = -EINVAL;
 609                 } else {
 610
 611                         #ifdef WANDEBUG
 612                         printk(KERN_INFO "%s: registering interface %s...\n",
 613                                 wanrouter_modname, dev->name);
 614                         #endif
 615
 616                         err = register_netdev(dev);
 617                         if (!err) {
 618                                 struct net_device *slave = NULL;
 619                                 unsigned long smp_flags=0;
 620
 621                                 lock_adapter_irq(&wandev->lock, &smp_flags);
 622
 623                                 if (wandev->dev == NULL) {
 624                                         wandev->dev = dev;
 625                                 } else {
 626                                         for (slave=wandev->dev;
 627                                              DEV_TO_SLAVE(slave);
 628                                              slave = DEV_TO_SLAVE(slave))
 629                                                 DEV_TO_SLAVE(slave) = dev;
 630                                 }
 631                                 ++wandev->ndev;
 632
 633                                 unlock_adapter_irq(&wandev->lock, &smp_flags);
 634                                 err = 0;        /* done !!! */
 635                                 goto out;
 636                         }
 637                 }
 638                 if (wandev->del_if)
 639                         wandev->del_if(wandev, dev);
 640                 free_netdev(dev);
 641         }
 642
 643 out:
 644         kfree(cnf);
 645         return err;
 646 }
 647
 648
 649 /*
 650  *      Delete WAN logical channel.
 651  *       o verify user address space
 652  *       o copy configuration data to kernel address space
 653  */
 654
 655 static int wanrouter_device_del_if(struct wan_device *wandev, char __user *u_name)
 656 {
 657         char name[WAN_IFNAME_SZ + 1];
 658         int err = 0;
 659
 660         if (wandev->state == WAN_UNCONFIGURED)
 661                 return -ENODEV;
 662
 663         memset(name, 0, sizeof(name));
 664
 665         if (copy_from_user(name, u_name, WAN_IFNAME_SZ))
 666                 return -EFAULT;
 667
 668         err = wanrouter_delete_interface(wandev, name);
 669         if (err)
 670                 return err;
 671
 672         /* If last interface being deleted, shutdown card
 673          * This helps with administration at leaf nodes
 674          * (You can tell if the person at the other end of the phone
 675          * has an interface configured) and avoids DoS vulnerabilities
 676          * in binary driver files - this fixes a problem with the current
 677          * Sangoma driver going into strange states when all the network
 678          * interfaces are deleted and the link irrecoverably disconnected.
 679          */
 680
 681         if (!wandev->ndev && wandev->shutdown)
 682                 err = wandev->shutdown(wandev);
 683
 684         return err;
 685 }
 686
 687 /*
 688  *      Miscellaneous Functions
 689  */
 690
 691 /*
 692  *      Find WAN device by name.
 693  *      Return pointer to the WAN device data space or NULL if device not found.
 694  */
 695
 696 static struct wan_device *wanrouter_find_device(char *name)
 697 {
 698         struct wan_device *wandev;
 699
 700         for (wandev = wanrouter_router_devlist;
 701              wandev && strcmp(wandev->name, name);
 702                 wandev = wandev->next);
 703         return wandev;
 704 }
 705
 706 /*
 707  *      Delete WAN logical channel identified by its name.
 708  *      o find logical channel by its name
 709  *      o call driver's del_if() entry point
 710  *      o unregister network interface
 711  *      o unlink channel data space from linked list of channels
 712  *      o release channel data space
 713  *
 714  *      Return: 0               success
 715  *              -ENODEV         channel not found.
 716  *              -EBUSY          interface is open
 717  *
 718  *      Note: If (force != 0), then device will be destroyed even if interface
 719  *      associated with it is open. It's caller's responsibility to make
 720  *      sure that opened interfaces are not removed!
 721  */
 722
 723 static int wanrouter_delete_interface(struct wan_device *wandev, char *name)
 724 {
 725         struct net_device *dev = NULL, *prev = NULL;
 726         unsigned long smp_flags=0;
 727
 728         lock_adapter_irq(&wandev->lock, &smp_flags);
 729         dev = wandev->dev;
 730         prev = NULL;
 731         while (dev && strcmp(name, dev->name)) {
 732                 struct net_device **slave = netdev_priv(dev);
 733                 prev = dev;
 734                 dev = *slave;
 735         }
 736         unlock_adapter_irq(&wandev->lock, &smp_flags);
 737
 738         if (dev == NULL)
 739                 return -ENODEV; /* interface not found */
 740
 741         if (netif_running(dev))
 742                 return -EBUSY;  /* interface in use */
 743
 744         if (wandev->del_if)
 745                 wandev->del_if(wandev, dev);
 746
 747         lock_adapter_irq(&wandev->lock, &smp_flags);
 748         if (prev) {
 749                 struct net_device **prev_slave = netdev_priv(prev);
 750                 struct net_device **slave = netdev_priv(dev);
 751
 752                 *prev_slave = *slave;
 753         } else {
 754                 struct net_device **slave = netdev_priv(dev);
 755                 wandev->dev = *slave;
 756         }
 757         --wandev->ndev;
 758         unlock_adapter_irq(&wandev->lock, &smp_flags);
 759
 760         printk(KERN_INFO "%s: unregistering '%s'\n", wandev->name, dev->name);
 761
 762         unregister_netdev(dev);
 763
 764         free_netdev(dev);
 765
 766         return 0;
 767 }
 768
 769 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
 770         __acquires(lock)
 771 {
 772         spin_lock_irqsave(lock, *smp_flags);
 773 }
 774
 775
 776 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
 777         __releases(lock)
 778 {
 779         spin_unlock_irqrestore(lock, *smp_flags);
 780 }
 781
 782 EXPORT_SYMBOL(register_wan_device);
 783 EXPORT_SYMBOL(unregister_wan_device);
 784
 785 MODULE_LICENSE("GPL");
 786
 787 /*
 788  *      End
 789  */