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 #include <net/syncppp.h>
  61
  62 #define KMEM_SAFETYZONE 8
  63
  64 /*
  65  *      Function Prototypes
  66  */
  67
  68 /*
  69  *      WAN device IOCTL handlers
  70  */
  71
  72 static int wanrouter_device_setup(struct wan_device *wandev,
  73                                   wandev_conf_t __user *u_conf);
  74 static int wanrouter_device_stat(struct wan_device *wandev,
  75                                  wandev_stat_t __user *u_stat);
  76 static int wanrouter_device_shutdown(struct wan_device *wandev);
  77 static int wanrouter_device_new_if(struct wan_device *wandev,
  78                                    wanif_conf_t __user *u_conf);
  79 static int wanrouter_device_del_if(struct wan_device *wandev,
  80                                    char __user *u_name);
  81
  82 /*
  83  *      Miscellaneous
  84  */
  85
  86 static struct wan_device *wanrouter_find_device(char *name);
  87 static int wanrouter_delete_interface(struct wan_device *wandev, char *name);
  88 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags);
  89 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags);
  90
  91
  92
  93 /*
  94  *      Global Data
  95  */
  96
  97 static char wanrouter_fullname[]  = "Sangoma WANPIPE Router";
  98 static char wanrouter_copyright[] = "(c) 1995-2000 Sangoma Technologies Inc.";
  99 static char wanrouter_modname[] = ROUTER_NAME; /* short module name */
 100 struct wan_device* wanrouter_router_devlist; /* list of registered devices */
 101
 102 /*
 103  *      Organize Unique Identifiers for encapsulation/decapsulation
 104  */
 105
 106 #if 0
 107 static unsigned char wanrouter_oui_ether[] = { 0x00, 0x00, 0x00 };
 108 static unsigned char wanrouter_oui_802_2[] = { 0x00, 0x80, 0xC2 };
 109 #endif
 110
 111 static int __init wanrouter_init(void)
 112 {
 113         int err;
 114
 115         printk(KERN_INFO "%s v%u.%u %s\n",
 116                wanrouter_fullname, ROUTER_VERSION, ROUTER_RELEASE,
 117                wanrouter_copyright);
 118
 119         err = wanrouter_proc_init();
 120         if (err)
 121                 printk(KERN_INFO "%s: can't create entry in proc filesystem!\n",
 122                        wanrouter_modname);
 123
 124         return err;
 125 }
 126
 127 static void __exit wanrouter_cleanup (void)
 128 {
 129         wanrouter_proc_cleanup();
 130 }
 131
 132 /*
 133  * This is just plain dumb.  We should move the bugger to drivers/net/wan,
 134  * slap it first in directory and make it module_init().  The only reason
 135  * for subsys_initcall() here is that net goes after drivers (why, BTW?)
 136  */
 137 subsys_initcall(wanrouter_init);
 138 module_exit(wanrouter_cleanup);
 139
 140 /*
 141  *      Kernel APIs
 142  */
 143
 144 /*
 145  *      Register WAN device.
 146  *      o verify device credentials
 147  *      o create an entry for the device in the /proc/net/router directory
 148  *      o initialize internally maintained fields of the wan_device structure
 149  *      o link device data space to a singly-linked list
 150  *      o if it's the first device, then start kernel 'thread'
 151  *      o increment module use count
 152  *
 153  *      Return:
 154  *      0       Ok
 155  *      < 0     error.
 156  *
 157  *      Context:        process
 158  */
 159
 160
 161 int register_wan_device(struct wan_device *wandev)
 162 {
 163         int err, namelen;
 164
 165         if ((wandev == NULL) || (wandev->magic != ROUTER_MAGIC) ||
 166             (wandev->name == NULL))
 167                 return -EINVAL;
 168
 169         namelen = strlen(wandev->name);
 170         if (!namelen || (namelen > WAN_DRVNAME_SZ))
 171                 return -EINVAL;
 172
 173         if (wanrouter_find_device(wandev->name))
 174                 return -EEXIST;
 175
 176 #ifdef WANDEBUG
 177         printk(KERN_INFO "%s: registering WAN device %s\n",
 178                wanrouter_modname, wandev->name);
 179 #endif
 180
 181         /*
 182          *      Register /proc directory entry
 183          */
 184         err = wanrouter_proc_add(wandev);
 185         if (err) {
 186                 printk(KERN_INFO
 187                         "%s: can't create /proc/net/router/%s entry!\n",
 188                         wanrouter_modname, wandev->name);
 189                 return err;
 190         }
 191
 192         /*
 193          *      Initialize fields of the wan_device structure maintained by the
 194          *      router and update local data.
 195          */
 196
 197         wandev->ndev = 0;
 198         wandev->dev  = NULL;
 199         wandev->next = wanrouter_router_devlist;
 200         wanrouter_router_devlist = wandev;
 201         return 0;
 202 }
 203
 204 /*
 205  *      Unregister WAN device.
 206  *      o shut down device
 207  *      o unlink device data space from the linked list
 208  *      o delete device entry in the /proc/net/router directory
 209  *      o decrement module use count
 210  *
 211  *      Return:         0       Ok
 212  *                      <0      error.
 213  *      Context:        process
 214  */
 215
 216
 217 int unregister_wan_device(char *name)
 218 {
 219         struct wan_device *wandev, *prev;
 220
 221         if (name == NULL)
 222                 return -EINVAL;
 223
 224         for (wandev = wanrouter_router_devlist, prev = NULL;
 225                 wandev && strcmp(wandev->name, name);
 226                 prev = wandev, wandev = wandev->next)
 227                 ;
 228         if (wandev == NULL)
 229                 return -ENODEV;
 230
 231 #ifdef WANDEBUG
 232         printk(KERN_INFO "%s: unregistering WAN device %s\n",
 233                wanrouter_modname, name);
 234 #endif
 235
 236         if (wandev->state != WAN_UNCONFIGURED)
 237                 wanrouter_device_shutdown(wandev);
 238
 239         if (prev)
 240                 prev->next = wandev->next;
 241         else
 242                 wanrouter_router_devlist = wandev->next;
 243
 244         wanrouter_proc_delete(wandev);
 245         return 0;
 246 }
 247
 248 #if 0
 249
 250 /*
 251  *      Encapsulate packet.
 252  *
 253  *      Return: encapsulation header size
 254  *              < 0     - unsupported Ethertype
 255  *
 256  *      Notes:
 257  *      1. This function may be called on interrupt context.
 258  */
 259
 260
 261 int wanrouter_encapsulate(struct sk_buff *skb, struct net_device *dev,
 262                           unsigned short type)
 263 {
 264         int hdr_len = 0;
 265
 266         switch (type) {
 267         case ETH_P_IP:          /* IP datagram encapsulation */
 268                 hdr_len += 1;
 269                 skb_push(skb, 1);
 270                 skb->data[0] = NLPID_IP;
 271                 break;
 272
 273         case ETH_P_IPX:         /* SNAP encapsulation */
 274         case ETH_P_ARP:
 275                 hdr_len += 7;
 276                 skb_push(skb, 7);
 277                 skb->data[0] = 0;
 278                 skb->data[1] = NLPID_SNAP;
 279                 skb_copy_to_linear_data_offset(skb, 2, wanrouter_oui_ether,
 280                                                sizeof(wanrouter_oui_ether));
 281                 *((unsigned short*)&skb->data[5]) = htons(type);
 282                 break;
 283
 284         default:                /* Unknown packet type */
 285                 printk(KERN_INFO
 286                         "%s: unsupported Ethertype 0x%04X on interface %s!\n",
 287                         wanrouter_modname, type, dev->name);
 288                 hdr_len = -EINVAL;
 289         }
 290         return hdr_len;
 291 }
 292
 293
 294 /*
 295  *      Decapsulate packet.
 296  *
 297  *      Return: Ethertype (in network order)
 298  *                      0       unknown encapsulation
 299  *
 300  *      Notes:
 301  *      1. This function may be called on interrupt context.
 302  */
 303
 304
 305 __be16 wanrouter_type_trans(struct sk_buff *skb, struct net_device *dev)
 306 {
 307         int cnt = skb->data[0] ? 0 : 1; /* there may be a pad present */
 308         __be16 ethertype;
 309
 310         switch (skb->data[cnt]) {
 311         case NLPID_IP:          /* IP datagramm */
 312                 ethertype = htons(ETH_P_IP);
 313                 cnt += 1;
 314                 break;
 315
 316         case NLPID_SNAP:        /* SNAP encapsulation */
 317                 if (memcmp(&skb->data[cnt + 1], wanrouter_oui_ether,
 318                            sizeof(wanrouter_oui_ether))){
 319                         printk(KERN_INFO
 320                                 "%s: unsupported SNAP OUI %02X-%02X-%02X "
 321                                 "on interface %s!\n", wanrouter_modname,
 322                                 skb->data[cnt+1], skb->data[cnt+2],
 323                                 skb->data[cnt+3], dev->name);
 324                         return 0;
 325                 }
 326                 ethertype = *((__be16*)&skb->data[cnt+4]);
 327                 cnt += 6;
 328                 break;
 329
 330         /* add other protocols, e.g. CLNP, ESIS, ISIS, if needed */
 331
 332         default:
 333                 printk(KERN_INFO
 334                         "%s: unsupported NLPID 0x%02X on interface %s!\n",
 335                         wanrouter_modname, skb->data[cnt], dev->name);
 336                 return 0;
 337         }
 338         skb->protocol = ethertype;
 339         skb->pkt_type = PACKET_HOST;    /*      Physically point to point */
 340         skb_pull(skb, cnt);
 341         skb_reset_mac_header(skb);
 342         return ethertype;
 343 }
 344
 345 #endif  /*  0  */
 346
 347 /*
 348  *      WAN device IOCTL.
 349  *      o find WAN device associated with this node
 350  *      o execute requested action or pass command to the device driver
 351  */
 352
 353 long wanrouter_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 354 {
 355         struct inode *inode = file->f_path.dentry->d_inode;
 356         int err = 0;
 357         struct proc_dir_entry *dent;
 358         struct wan_device *wandev;
 359         void __user *data = (void __user *)arg;
 360
 361         if (!capable(CAP_NET_ADMIN))
 362                 return -EPERM;
 363
 364         if ((cmd >> 8) != ROUTER_IOCTL)
 365                 return -EINVAL;
 366
 367         dent = PDE(inode);
 368         if ((dent == NULL) || (dent->data == NULL))
 369                 return -EINVAL;
 370
 371         wandev = dent->data;
 372         if (wandev->magic != ROUTER_MAGIC)
 373                 return -EINVAL;
 374
 375         lock_kernel();
 376         switch (cmd) {
 377         case ROUTER_SETUP:
 378                 err = wanrouter_device_setup(wandev, data);
 379                 break;
 380
 381         case ROUTER_DOWN:
 382                 err = wanrouter_device_shutdown(wandev);
 383                 break;
 384
 385         case ROUTER_STAT:
 386                 err = wanrouter_device_stat(wandev, data);
 387                 break;
 388
 389         case ROUTER_IFNEW:
 390                 err = wanrouter_device_new_if(wandev, data);
 391                 break;
 392
 393         case ROUTER_IFDEL:
 394                 err = wanrouter_device_del_if(wandev, data);
 395                 break;
 396
 397         case ROUTER_IFSTAT:
 398                 break;
 399
 400         default:
 401                 if ((cmd >= ROUTER_USER) &&
 402                     (cmd <= ROUTER_USER_MAX) &&
 403                     wandev->ioctl)
 404                         err = wandev->ioctl(wandev, cmd, arg);
 405                 else err = -EINVAL;
 406         }
 407         unlock_kernel();
 408         return err;
 409 }
 410
 411 /*
 412  *      WAN Driver IOCTL Handlers
 413  */
 414
 415 /*
 416  *      Setup WAN link device.
 417  *      o verify user address space
 418  *      o allocate kernel memory and copy configuration data to kernel space
 419  *      o if configuration data includes extension, copy it to kernel space too
 420  *      o call driver's setup() entry point
 421  */
 422
 423 static int wanrouter_device_setup(struct wan_device *wandev,
 424                                   wandev_conf_t __user *u_conf)
 425 {
 426         void *data = NULL;
 427         wandev_conf_t *conf;
 428         int err = -EINVAL;
 429
 430         if (wandev->setup == NULL) {    /* Nothing to do ? */
 431                 printk(KERN_INFO "%s: ERROR, No setup script: wandev->setup()\n",
 432                                 wandev->name);
 433                 return 0;
 434         }
 435
 436         conf = kmalloc(sizeof(wandev_conf_t), GFP_KERNEL);
 437         if (conf == NULL){
 438                 printk(KERN_INFO "%s: ERROR, Failed to allocate kernel memory !\n",
 439                                 wandev->name);
 440                 return -ENOBUFS;
 441         }
 442
 443         if (copy_from_user(conf, u_conf, sizeof(wandev_conf_t))) {
 444                 printk(KERN_INFO "%s: Failed to copy user config data to kernel space!\n",
 445                                 wandev->name);
 446                 kfree(conf);
 447                 return -EFAULT;
 448         }
 449
 450         if (conf->magic != ROUTER_MAGIC) {
 451                 kfree(conf);
 452                 printk(KERN_INFO "%s: ERROR, Invalid MAGIC Number\n",
 453                                 wandev->name);
 454                 return -EINVAL;
 455         }
 456
 457         if (conf->data_size && conf->data) {
 458                 if (conf->data_size > 128000) {
 459                         printk(KERN_INFO
 460                             "%s: ERROR, Invalid firmware data size %i !\n",
 461                                         wandev->name, conf->data_size);
 462                         kfree(conf);
 463                         return -EINVAL;
 464                 }
 465
 466                 data = vmalloc(conf->data_size);
 467                 if (!data) {
 468                         printk(KERN_INFO
 469                                 "%s: ERROR, Faild allocate kernel memory !\n",
 470                                 wandev->name);
 471                         kfree(conf);
 472                         return -ENOBUFS;
 473                 }
 474                 if (!copy_from_user(data, conf->data, conf->data_size)) {
 475                         conf->data = data;
 476                         err = wandev->setup(wandev, conf);
 477                 } else {
 478                         printk(KERN_INFO
 479                              "%s: ERROR, Faild to copy from user data !\n",
 480                                wandev->name);
 481                         err = -EFAULT;
 482                 }
 483                 vfree(data);
 484         } else {
 485                 printk(KERN_INFO
 486                     "%s: ERROR, No firmware found ! Firmware size = %i !\n",
 487                                 wandev->name, conf->data_size);
 488         }
 489
 490         kfree(conf);
 491         return err;
 492 }
 493
 494 /*
 495  *      Shutdown WAN device.
 496  *      o delete all not opened logical channels for this device
 497  *      o call driver's shutdown() entry point
 498  */
 499
 500 static int wanrouter_device_shutdown(struct wan_device *wandev)
 501 {
 502         struct net_device *dev;
 503         int err=0;
 504
 505         if (wandev->state == WAN_UNCONFIGURED)
 506                 return 0;
 507
 508         printk(KERN_INFO "\n%s: Shutting Down!\n",wandev->name);
 509
 510         for (dev = wandev->dev; dev;) {
 511                 err = wanrouter_delete_interface(wandev, dev->name);
 512                 if (err)
 513                         return err;
 514                 /* The above function deallocates the current dev
 515                  * structure. Therefore, we cannot use dev->priv
 516                  * as the next element: wandev->dev points to the
 517                  * next element */
 518                 dev = wandev->dev;
 519         }
 520
 521         if (wandev->ndev)
 522                 return -EBUSY;  /* there are opened interfaces  */
 523
 524         if (wandev->shutdown)
 525                 err=wandev->shutdown(wandev);
 526
 527         return err;
 528 }
 529
 530 /*
 531  *      Get WAN device status & statistics.
 532  */
 533
 534 static int wanrouter_device_stat(struct wan_device *wandev,
 535                                  wandev_stat_t __user *u_stat)
 536 {
 537         wandev_stat_t stat;
 538
 539         memset(&stat, 0, sizeof(stat));
 540
 541         /* Ask device driver to update device statistics */
 542         if ((wandev->state != WAN_UNCONFIGURED) && wandev->update)
 543                 wandev->update(wandev);
 544
 545         /* Fill out structure */
 546         stat.ndev  = wandev->ndev;
 547         stat.state = wandev->state;
 548
 549         if (copy_to_user(u_stat, &stat, sizeof(stat)))
 550                 return -EFAULT;
 551
 552         return 0;
 553 }
 554
 555 /*
 556  *      Create new WAN interface.
 557  *      o verify user address space
 558  *      o copy configuration data to kernel address space
 559  *      o allocate network interface data space
 560  *      o call driver's new_if() entry point
 561  *      o make sure there is no interface name conflict
 562  *      o register network interface
 563  */
 564
 565 static int wanrouter_device_new_if(struct wan_device *wandev,
 566                                    wanif_conf_t __user *u_conf)
 567 {
 568         wanif_conf_t *cnf;
 569         struct net_device *dev = NULL;
 570 #ifdef CONFIG_WANPIPE_MULTPPP
 571         struct ppp_device *pppdev=NULL;
 572 #endif
 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 #ifdef CONFIG_WANPIPE_MULTPPP
 592                 pppdev = kzalloc(sizeof(struct ppp_device), GFP_KERNEL);
 593                 err = -ENOBUFS;
 594                 if (pppdev == NULL)
 595                         goto out;
 596                 pppdev->dev = kzalloc(sizeof(struct net_device), GFP_KERNEL);
 597                 if (pppdev->dev == NULL) {
 598                         kfree(pppdev);
 599                         err = -ENOBUFS;
 600                         goto out;
 601                 }
 602                 err = wandev->new_if(wandev, (struct net_device *)pppdev, cnf);
 603                 dev = pppdev->dev;
 604 #else
 605                 printk(KERN_INFO "%s: Wanpipe Mulit-Port PPP support has not been compiled in!\n",
 606                                 wandev->name);
 607                 err = -EPROTONOSUPPORT;
 608                 goto out;
 609 #endif
 610         } else {
 611                 dev = kzalloc(sizeof(struct net_device), GFP_KERNEL);
 612                 err = -ENOBUFS;
 613                 if (dev == NULL)
 614                         goto out;
 615                 err = wandev->new_if(wandev, dev, cnf);
 616         }
 617
 618         if (!err) {
 619                 /* Register network interface. This will invoke init()
 620                  * function supplied by the driver.  If device registered
 621                  * successfully, add it to the interface list.
 622                  */
 623
 624                 if (dev->name == NULL) {
 625                         err = -EINVAL;
 626                 } else {
 627
 628                         #ifdef WANDEBUG
 629                         printk(KERN_INFO "%s: registering interface %s...\n",
 630                                 wanrouter_modname, dev->name);
 631                         #endif
 632
 633                         err = register_netdev(dev);
 634                         if (!err) {
 635                                 struct net_device *slave = NULL;
 636                                 unsigned long smp_flags=0;
 637
 638                                 lock_adapter_irq(&wandev->lock, &smp_flags);
 639
 640                                 if (wandev->dev == NULL) {
 641                                         wandev->dev = dev;
 642                                 } else {
 643                                         for (slave=wandev->dev;
 644                                          *((struct net_device **)slave->priv);
 645                                  slave = *((struct net_device **)slave->priv));
 646
 647                                      *((struct net_device **)slave->priv) = dev;
 648                                 }
 649                                 ++wandev->ndev;
 650
 651                                 unlock_adapter_irq(&wandev->lock, &smp_flags);
 652                                 err = 0;        /* done !!! */
 653                                 goto out;
 654                         }
 655                 }
 656                 if (wandev->del_if)
 657                         wandev->del_if(wandev, dev);
 658         }
 659
 660         /* This code has moved from del_if() function */
 661         kfree(dev->priv);
 662         dev->priv = NULL;
 663
 664 #ifdef CONFIG_WANPIPE_MULTPPP
 665         if (cnf->config_id == WANCONFIG_MPPP)
 666                 kfree(pppdev);
 667         else
 668                 kfree(dev);
 669 #else
 670         /* Sync PPP is disabled */
 671         if (cnf->config_id != WANCONFIG_MPPP)
 672                 kfree(dev);
 673 #endif
 674
 675 out:
 676         kfree(cnf);
 677         return err;
 678 }
 679
 680
 681 /*
 682  *      Delete WAN logical channel.
 683  *       o verify user address space
 684  *       o copy configuration data to kernel address space
 685  */
 686
 687 static int wanrouter_device_del_if(struct wan_device *wandev, char __user *u_name)
 688 {
 689         char name[WAN_IFNAME_SZ + 1];
 690         int err = 0;
 691
 692         if (wandev->state == WAN_UNCONFIGURED)
 693                 return -ENODEV;
 694
 695         memset(name, 0, sizeof(name));
 696
 697         if (copy_from_user(name, u_name, WAN_IFNAME_SZ))
 698                 return -EFAULT;
 699
 700         err = wanrouter_delete_interface(wandev, name);
 701         if (err)
 702                 return err;
 703
 704         /* If last interface being deleted, shutdown card
 705          * This helps with administration at leaf nodes
 706          * (You can tell if the person at the other end of the phone
 707          * has an interface configured) and avoids DoS vulnerabilities
 708          * in binary driver files - this fixes a problem with the current
 709          * Sangoma driver going into strange states when all the network
 710          * interfaces are deleted and the link irrecoverably disconnected.
 711          */
 712
 713         if (!wandev->ndev && wandev->shutdown)
 714                 err = wandev->shutdown(wandev);
 715
 716         return err;
 717 }
 718
 719 /*
 720  *      Miscellaneous Functions
 721  */
 722
 723 /*
 724  *      Find WAN device by name.
 725  *      Return pointer to the WAN device data space or NULL if device not found.
 726  */
 727
 728 static struct wan_device *wanrouter_find_device(char *name)
 729 {
 730         struct wan_device *wandev;
 731
 732         for (wandev = wanrouter_router_devlist;
 733              wandev && strcmp(wandev->name, name);
 734                 wandev = wandev->next);
 735         return wandev;
 736 }
 737
 738 /*
 739  *      Delete WAN logical channel identified by its name.
 740  *      o find logical channel by its name
 741  *      o call driver's del_if() entry point
 742  *      o unregister network interface
 743  *      o unlink channel data space from linked list of channels
 744  *      o release channel data space
 745  *
 746  *      Return: 0               success
 747  *              -ENODEV         channel not found.
 748  *              -EBUSY          interface is open
 749  *
 750  *      Note: If (force != 0), then device will be destroyed even if interface
 751  *      associated with it is open. It's caller's responsibility to make
 752  *      sure that opened interfaces are not removed!
 753  */
 754
 755 static int wanrouter_delete_interface(struct wan_device *wandev, char *name)
 756 {
 757         struct net_device *dev = NULL, *prev = NULL;
 758         unsigned long smp_flags=0;
 759
 760         lock_adapter_irq(&wandev->lock, &smp_flags);
 761         dev = wandev->dev;
 762         prev = NULL;
 763         while (dev && strcmp(name, dev->name)) {
 764                 struct net_device **slave = dev->priv;
 765                 prev = dev;
 766                 dev = *slave;
 767         }
 768         unlock_adapter_irq(&wandev->lock, &smp_flags);
 769
 770         if (dev == NULL)
 771                 return -ENODEV; /* interface not found */
 772
 773         if (netif_running(dev))
 774                 return -EBUSY;  /* interface in use */
 775
 776         if (wandev->del_if)
 777                 wandev->del_if(wandev, dev);
 778
 779         lock_adapter_irq(&wandev->lock, &smp_flags);
 780         if (prev) {
 781                 struct net_device **prev_slave = prev->priv;
 782                 struct net_device **slave = dev->priv;
 783
 784                 *prev_slave = *slave;
 785         } else {
 786                 struct net_device **slave = dev->priv;
 787                 wandev->dev = *slave;
 788         }
 789         --wandev->ndev;
 790         unlock_adapter_irq(&wandev->lock, &smp_flags);
 791
 792         printk(KERN_INFO "%s: unregistering '%s'\n", wandev->name, dev->name);
 793
 794         /* Due to new interface linking method using dev->priv,
 795          * this code has moved from del_if() function.*/
 796         kfree(dev->priv);
 797         dev->priv=NULL;
 798
 799         unregister_netdev(dev);
 800
 801         free_netdev(dev);
 802
 803         return 0;
 804 }
 805
 806 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
 807 {
 808         spin_lock_irqsave(lock, *smp_flags);
 809 }
 810
 811
 812 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
 813 {
 814         spin_unlock_irqrestore(lock, *smp_flags);
 815 }
 816
 817 EXPORT_SYMBOL(register_wan_device);
 818 EXPORT_SYMBOL(unregister_wan_device);
 819
 820 MODULE_LICENSE("GPL");
 821
 822 /*
 823  *      End
 824  */