fix printk typo 'faild'
[linux-2.6.git] / 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  */