[NET]: Fix comparisons of unsigned < 0.
[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/init.h>
50 #include <linux/module.h>       /* support for loadable modules */
51 #include <linux/slab.h>         /* kmalloc(), kfree() */
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 #include <net/syncppp.h>
62
63 #define KMEM_SAFETYZONE 8
64
65 /*
66  *      Function Prototypes
67  */
68
69 /*
70  *      WAN device IOCTL handlers
71  */
72
73 static int wanrouter_device_setup(struct wan_device *wandev,
74                                   wandev_conf_t __user *u_conf);
75 static int wanrouter_device_stat(struct wan_device *wandev,
76                                  wandev_stat_t __user *u_stat);
77 static int wanrouter_device_shutdown(struct wan_device *wandev);
78 static int wanrouter_device_new_if(struct wan_device *wandev,
79                                    wanif_conf_t __user *u_conf);
80 static int wanrouter_device_del_if(struct wan_device *wandev,
81                                    char __user *u_name);
82
83 /*
84  *      Miscellaneous
85  */
86
87 static struct wan_device *wanrouter_find_device(char *name);
88 static int wanrouter_delete_interface(struct wan_device *wandev, char *name);
89 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags);
90 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags);
91
92
93
94 /*
95  *      Global Data
96  */
97
98 static char wanrouter_fullname[]  = "Sangoma WANPIPE Router";
99 static char wanrouter_copyright[] = "(c) 1995-2000 Sangoma Technologies Inc.";
100 static char wanrouter_modname[] = ROUTER_NAME; /* short module name */
101 struct wan_device* wanrouter_router_devlist; /* list of registered devices */
102
103 /*
104  *      Organize Unique Identifiers for encapsulation/decapsulation
105  */
106
107 #if 0
108 static unsigned char wanrouter_oui_ether[] = { 0x00, 0x00, 0x00 };
109 static unsigned char wanrouter_oui_802_2[] = { 0x00, 0x80, 0xC2 };
110 #endif
111
112 static int __init wanrouter_init(void)
113 {
114         int err;
115
116         printk(KERN_INFO "%s v%u.%u %s\n",
117                wanrouter_fullname, ROUTER_VERSION, ROUTER_RELEASE,
118                wanrouter_copyright);
119
120         err = wanrouter_proc_init();
121         if (err)
122                 printk(KERN_INFO "%s: can't create entry in proc filesystem!\n",
123                        wanrouter_modname);
124
125         return err;
126 }
127
128 static void __exit wanrouter_cleanup (void)
129 {
130         wanrouter_proc_cleanup();
131 }
132
133 /*
134  * This is just plain dumb.  We should move the bugger to drivers/net/wan,
135  * slap it first in directory and make it module_init().  The only reason
136  * for subsys_initcall() here is that net goes after drivers (why, BTW?)
137  */
138 subsys_initcall(wanrouter_init);
139 module_exit(wanrouter_cleanup);
140
141 /*
142  *      Kernel APIs
143  */
144
145 /*
146  *      Register WAN device.
147  *      o verify device credentials
148  *      o create an entry for the device in the /proc/net/router directory
149  *      o initialize internally maintained fields of the wan_device structure
150  *      o link device data space to a singly-linked list
151  *      o if it's the first device, then start kernel 'thread'
152  *      o increment module use count
153  *
154  *      Return:
155  *      0       Ok
156  *      < 0     error.
157  *
158  *      Context:        process
159  */
160
161
162 int register_wan_device(struct wan_device *wandev)
163 {
164         int err, namelen;
165
166         if ((wandev == NULL) || (wandev->magic != ROUTER_MAGIC) ||
167             (wandev->name == NULL))
168                 return -EINVAL;
169
170         namelen = strlen(wandev->name);
171         if (!namelen || (namelen > WAN_DRVNAME_SZ))
172                 return -EINVAL;
173
174         if (wanrouter_find_device(wandev->name))
175                 return -EEXIST;
176
177 #ifdef WANDEBUG
178         printk(KERN_INFO "%s: registering WAN device %s\n",
179                wanrouter_modname, wandev->name);
180 #endif
181
182         /*
183          *      Register /proc directory entry
184          */
185         err = wanrouter_proc_add(wandev);
186         if (err) {
187                 printk(KERN_INFO
188                         "%s: can't create /proc/net/router/%s entry!\n",
189                         wanrouter_modname, wandev->name);
190                 return err;
191         }
192
193         /*
194          *      Initialize fields of the wan_device structure maintained by the
195          *      router and update local data.
196          */
197
198         wandev->ndev = 0;
199         wandev->dev  = NULL;
200         wandev->next = wanrouter_router_devlist;
201         wanrouter_router_devlist = wandev;
202         return 0;
203 }
204
205 /*
206  *      Unregister WAN device.
207  *      o shut down device
208  *      o unlink device data space from the linked list
209  *      o delete device entry in the /proc/net/router directory
210  *      o decrement module use count
211  *
212  *      Return:         0       Ok
213  *                      <0      error.
214  *      Context:        process
215  */
216
217
218 int unregister_wan_device(char *name)
219 {
220         struct wan_device *wandev, *prev;
221
222         if (name == NULL)
223                 return -EINVAL;
224
225         for (wandev = wanrouter_router_devlist, prev = NULL;
226                 wandev && strcmp(wandev->name, name);
227                 prev = wandev, wandev = wandev->next)
228                 ;
229         if (wandev == NULL)
230                 return -ENODEV;
231
232 #ifdef WANDEBUG
233         printk(KERN_INFO "%s: unregistering WAN device %s\n",
234                wanrouter_modname, name);
235 #endif
236
237         if (wandev->state != WAN_UNCONFIGURED)
238                 wanrouter_device_shutdown(wandev);
239
240         if (prev)
241                 prev->next = wandev->next;
242         else
243                 wanrouter_router_devlist = wandev->next;
244
245         wanrouter_proc_delete(wandev);
246         return 0;
247 }
248
249 #if 0
250
251 /*
252  *      Encapsulate packet.
253  *
254  *      Return: encapsulation header size
255  *              < 0     - unsupported Ethertype
256  *
257  *      Notes:
258  *      1. This function may be called on interrupt context.
259  */
260
261
262 int wanrouter_encapsulate(struct sk_buff *skb, struct net_device *dev,
263                           unsigned short type)
264 {
265         int hdr_len = 0;
266
267         switch (type) {
268         case ETH_P_IP:          /* IP datagram encapsulation */
269                 hdr_len += 1;
270                 skb_push(skb, 1);
271                 skb->data[0] = NLPID_IP;
272                 break;
273
274         case ETH_P_IPX:         /* SNAP encapsulation */
275         case ETH_P_ARP:
276                 hdr_len += 7;
277                 skb_push(skb, 7);
278                 skb->data[0] = 0;
279                 skb->data[1] = NLPID_SNAP;
280                 skb_copy_to_linear_data_offset(skb, 2, wanrouter_oui_ether,
281                                                sizeof(wanrouter_oui_ether));
282                 *((unsigned short*)&skb->data[5]) = htons(type);
283                 break;
284
285         default:                /* Unknown packet type */
286                 printk(KERN_INFO
287                         "%s: unsupported Ethertype 0x%04X on interface %s!\n",
288                         wanrouter_modname, type, dev->name);
289                 hdr_len = -EINVAL;
290         }
291         return hdr_len;
292 }
293
294
295 /*
296  *      Decapsulate packet.
297  *
298  *      Return: Ethertype (in network order)
299  *                      0       unknown encapsulation
300  *
301  *      Notes:
302  *      1. This function may be called on interrupt context.
303  */
304
305
306 __be16 wanrouter_type_trans(struct sk_buff *skb, struct net_device *dev)
307 {
308         int cnt = skb->data[0] ? 0 : 1; /* there may be a pad present */
309         __be16 ethertype;
310
311         switch (skb->data[cnt]) {
312         case NLPID_IP:          /* IP datagramm */
313                 ethertype = htons(ETH_P_IP);
314                 cnt += 1;
315                 break;
316
317         case NLPID_SNAP:        /* SNAP encapsulation */
318                 if (memcmp(&skb->data[cnt + 1], wanrouter_oui_ether,
319                            sizeof(wanrouter_oui_ether))){
320                         printk(KERN_INFO
321                                 "%s: unsupported SNAP OUI %02X-%02X-%02X "
322                                 "on interface %s!\n", wanrouter_modname,
323                                 skb->data[cnt+1], skb->data[cnt+2],
324                                 skb->data[cnt+3], dev->name);
325                         return 0;
326                 }
327                 ethertype = *((__be16*)&skb->data[cnt+4]);
328                 cnt += 6;
329                 break;
330
331         /* add other protocols, e.g. CLNP, ESIS, ISIS, if needed */
332
333         default:
334                 printk(KERN_INFO
335                         "%s: unsupported NLPID 0x%02X on interface %s!\n",
336                         wanrouter_modname, skb->data[cnt], dev->name);
337                 return 0;
338         }
339         skb->protocol = ethertype;
340         skb->pkt_type = PACKET_HOST;    /*      Physically point to point */
341         skb_pull(skb, cnt);
342         skb_reset_mac_header(skb);
343         return ethertype;
344 }
345
346 #endif  /*  0  */
347
348 /*
349  *      WAN device IOCTL.
350  *      o find WAN device associated with this node
351  *      o execute requested action or pass command to the device driver
352  */
353
354 int wanrouter_ioctl(struct inode *inode, struct file *file,
355                 unsigned int cmd, unsigned long arg)
356 {
357         int err = 0;
358         struct proc_dir_entry *dent;
359         struct wan_device *wandev;
360         void __user *data = (void __user *)arg;
361
362         if (!capable(CAP_NET_ADMIN))
363                 return -EPERM;
364
365         if ((cmd >> 8) != ROUTER_IOCTL)
366                 return -EINVAL;
367
368         dent = PDE(inode);
369         if ((dent == NULL) || (dent->data == NULL))
370                 return -EINVAL;
371
372         wandev = dent->data;
373         if (wandev->magic != ROUTER_MAGIC)
374                 return -EINVAL;
375
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         return err;
408 }
409
410 /*
411  *      WAN Driver IOCTL Handlers
412  */
413
414 /*
415  *      Setup WAN link device.
416  *      o verify user address space
417  *      o allocate kernel memory and copy configuration data to kernel space
418  *      o if configuration data includes extension, copy it to kernel space too
419  *      o call driver's setup() entry point
420  */
421
422 static int wanrouter_device_setup(struct wan_device *wandev,
423                                   wandev_conf_t __user *u_conf)
424 {
425         void *data = NULL;
426         wandev_conf_t *conf;
427         int err = -EINVAL;
428
429         if (wandev->setup == NULL) {    /* Nothing to do ? */
430                 printk(KERN_INFO "%s: ERROR, No setup script: wandev->setup()\n",
431                                 wandev->name);
432                 return 0;
433         }
434
435         conf = kmalloc(sizeof(wandev_conf_t), GFP_KERNEL);
436         if (conf == NULL){
437                 printk(KERN_INFO "%s: ERROR, Failed to allocate kernel memory !\n",
438                                 wandev->name);
439                 return -ENOBUFS;
440         }
441
442         if (copy_from_user(conf, u_conf, sizeof(wandev_conf_t))) {
443                 printk(KERN_INFO "%s: Failed to copy user config data to kernel space!\n",
444                                 wandev->name);
445                 kfree(conf);
446                 return -EFAULT;
447         }
448
449         if (conf->magic != ROUTER_MAGIC) {
450                 kfree(conf);
451                 printk(KERN_INFO "%s: ERROR, Invalid MAGIC Number\n",
452                                 wandev->name);
453                 return -EINVAL;
454         }
455
456         if (conf->data_size && conf->data) {
457                 if (conf->data_size > 128000) {
458                         printk(KERN_INFO
459                             "%s: ERROR, Invalid firmware data size %i !\n",
460                                         wandev->name, conf->data_size);
461                         kfree(conf);
462                         return -EINVAL;
463                 }
464
465                 data = vmalloc(conf->data_size);
466                 if (!data) {
467                         printk(KERN_INFO
468                                 "%s: ERROR, Faild allocate kernel memory !\n",
469                                 wandev->name);
470                         kfree(conf);
471                         return -ENOBUFS;
472                 }
473                 if (!copy_from_user(data, conf->data, conf->data_size)) {
474                         conf->data = data;
475                         err = wandev->setup(wandev, conf);
476                 } else {
477                         printk(KERN_INFO
478                              "%s: ERROR, Faild to copy from user data !\n",
479                                wandev->name);
480                         err = -EFAULT;
481                 }
482                 vfree(data);
483         } else {
484                 printk(KERN_INFO
485                     "%s: ERROR, No firmware found ! Firmware size = %i !\n",
486                                 wandev->name, conf->data_size);
487         }
488
489         kfree(conf);
490         return err;
491 }
492
493 /*
494  *      Shutdown WAN device.
495  *      o delete all not opened logical channels for this device
496  *      o call driver's shutdown() entry point
497  */
498
499 static int wanrouter_device_shutdown(struct wan_device *wandev)
500 {
501         struct net_device *dev;
502         int err=0;
503
504         if (wandev->state == WAN_UNCONFIGURED)
505                 return 0;
506
507         printk(KERN_INFO "\n%s: Shutting Down!\n",wandev->name);
508
509         for (dev = wandev->dev; dev;) {
510                 err = wanrouter_delete_interface(wandev, dev->name);
511                 if (err)
512                         return err;
513                 /* The above function deallocates the current dev
514                  * structure. Therefore, we cannot use dev->priv
515                  * as the next element: wandev->dev points to the
516                  * next element */
517                 dev = wandev->dev;
518         }
519
520         if (wandev->ndev)
521                 return -EBUSY;  /* there are opened interfaces  */
522
523         if (wandev->shutdown)
524                 err=wandev->shutdown(wandev);
525
526         return err;
527 }
528
529 /*
530  *      Get WAN device status & statistics.
531  */
532
533 static int wanrouter_device_stat(struct wan_device *wandev,
534                                  wandev_stat_t __user *u_stat)
535 {
536         wandev_stat_t stat;
537
538         memset(&stat, 0, sizeof(stat));
539
540         /* Ask device driver to update device statistics */
541         if ((wandev->state != WAN_UNCONFIGURED) && wandev->update)
542                 wandev->update(wandev);
543
544         /* Fill out structure */
545         stat.ndev  = wandev->ndev;
546         stat.state = wandev->state;
547
548         if (copy_to_user(u_stat, &stat, sizeof(stat)))
549                 return -EFAULT;
550
551         return 0;
552 }
553
554 /*
555  *      Create new WAN interface.
556  *      o verify user address space
557  *      o copy configuration data to kernel address space
558  *      o allocate network interface data space
559  *      o call driver's new_if() entry point
560  *      o make sure there is no interface name conflict
561  *      o register network interface
562  */
563
564 static int wanrouter_device_new_if(struct wan_device *wandev,
565                                    wanif_conf_t __user *u_conf)
566 {
567         wanif_conf_t *cnf;
568         struct net_device *dev = NULL;
569 #ifdef CONFIG_WANPIPE_MULTPPP
570         struct ppp_device *pppdev=NULL;
571 #endif
572         int err;
573
574         if ((wandev->state == WAN_UNCONFIGURED) || (wandev->new_if == NULL))
575                 return -ENODEV;
576
577         cnf = kmalloc(sizeof(wanif_conf_t), GFP_KERNEL);
578         if (!cnf)
579                 return -ENOBUFS;
580
581         err = -EFAULT;
582         if (copy_from_user(cnf, u_conf, sizeof(wanif_conf_t)))
583                 goto out;
584
585         err = -EINVAL;
586         if (cnf->magic != ROUTER_MAGIC)
587                 goto out;
588
589         if (cnf->config_id == WANCONFIG_MPPP) {
590 #ifdef CONFIG_WANPIPE_MULTPPP
591                 pppdev = kzalloc(sizeof(struct ppp_device), GFP_KERNEL);
592                 err = -ENOBUFS;
593                 if (pppdev == NULL)
594                         goto out;
595                 pppdev->dev = kzalloc(sizeof(struct net_device), GFP_KERNEL);
596                 if (pppdev->dev == NULL) {
597                         kfree(pppdev);
598                         err = -ENOBUFS;
599                         goto out;
600                 }
601                 err = wandev->new_if(wandev, (struct net_device *)pppdev, cnf);
602                 dev = pppdev->dev;
603 #else
604                 printk(KERN_INFO "%s: Wanpipe Mulit-Port PPP support has not been compiled in!\n",
605                                 wandev->name);
606                 err = -EPROTONOSUPPORT;
607                 goto out;
608 #endif
609         } else {
610                 dev = kzalloc(sizeof(struct net_device), GFP_KERNEL);
611                 err = -ENOBUFS;
612                 if (dev == NULL)
613                         goto out;
614                 err = wandev->new_if(wandev, dev, cnf);
615         }
616
617         if (!err) {
618                 /* Register network interface. This will invoke init()
619                  * function supplied by the driver.  If device registered
620                  * successfully, add it to the interface list.
621                  */
622
623                 if (dev->name == NULL) {
624                         err = -EINVAL;
625                 } else {
626
627                         #ifdef WANDEBUG
628                         printk(KERN_INFO "%s: registering interface %s...\n",
629                                 wanrouter_modname, dev->name);
630                         #endif
631
632                         err = register_netdev(dev);
633                         if (!err) {
634                                 struct net_device *slave = NULL;
635                                 unsigned long smp_flags=0;
636
637                                 lock_adapter_irq(&wandev->lock, &smp_flags);
638
639                                 if (wandev->dev == NULL) {
640                                         wandev->dev = dev;
641                                 } else {
642                                         for (slave=wandev->dev;
643                                          *((struct net_device **)slave->priv);
644                                  slave = *((struct net_device **)slave->priv));
645
646                                      *((struct net_device **)slave->priv) = dev;
647                                 }
648                                 ++wandev->ndev;
649
650                                 unlock_adapter_irq(&wandev->lock, &smp_flags);
651                                 err = 0;        /* done !!! */
652                                 goto out;
653                         }
654                 }
655                 if (wandev->del_if)
656                         wandev->del_if(wandev, dev);
657         }
658
659         /* This code has moved from del_if() function */
660         kfree(dev->priv);
661         dev->priv = NULL;
662
663 #ifdef CONFIG_WANPIPE_MULTPPP
664         if (cnf->config_id == WANCONFIG_MPPP)
665                 kfree(pppdev);
666         else
667                 kfree(dev);
668 #else
669         /* Sync PPP is disabled */
670         if (cnf->config_id != WANCONFIG_MPPP)
671                 kfree(dev);
672 #endif
673
674 out:
675         kfree(cnf);
676         return err;
677 }
678
679
680 /*
681  *      Delete WAN logical channel.
682  *       o verify user address space
683  *       o copy configuration data to kernel address space
684  */
685
686 static int wanrouter_device_del_if(struct wan_device *wandev, char __user *u_name)
687 {
688         char name[WAN_IFNAME_SZ + 1];
689         int err = 0;
690
691         if (wandev->state == WAN_UNCONFIGURED)
692                 return -ENODEV;
693
694         memset(name, 0, sizeof(name));
695
696         if (copy_from_user(name, u_name, WAN_IFNAME_SZ))
697                 return -EFAULT;
698
699         err = wanrouter_delete_interface(wandev, name);
700         if (err)
701                 return err;
702
703         /* If last interface being deleted, shutdown card
704          * This helps with administration at leaf nodes
705          * (You can tell if the person at the other end of the phone
706          * has an interface configured) and avoids DoS vulnerabilities
707          * in binary driver files - this fixes a problem with the current
708          * Sangoma driver going into strange states when all the network
709          * interfaces are deleted and the link irrecoverably disconnected.
710          */
711
712         if (!wandev->ndev && wandev->shutdown)
713                 err = wandev->shutdown(wandev);
714
715         return err;
716 }
717
718 /*
719  *      Miscellaneous Functions
720  */
721
722 /*
723  *      Find WAN device by name.
724  *      Return pointer to the WAN device data space or NULL if device not found.
725  */
726
727 static struct wan_device *wanrouter_find_device(char *name)
728 {
729         struct wan_device *wandev;
730
731         for (wandev = wanrouter_router_devlist;
732              wandev && strcmp(wandev->name, name);
733                 wandev = wandev->next);
734         return wandev;
735 }
736
737 /*
738  *      Delete WAN logical channel identified by its name.
739  *      o find logical channel by its name
740  *      o call driver's del_if() entry point
741  *      o unregister network interface
742  *      o unlink channel data space from linked list of channels
743  *      o release channel data space
744  *
745  *      Return: 0               success
746  *              -ENODEV         channel not found.
747  *              -EBUSY          interface is open
748  *
749  *      Note: If (force != 0), then device will be destroyed even if interface
750  *      associated with it is open. It's caller's responsibility to make
751  *      sure that opened interfaces are not removed!
752  */
753
754 static int wanrouter_delete_interface(struct wan_device *wandev, char *name)
755 {
756         struct net_device *dev = NULL, *prev = NULL;
757         unsigned long smp_flags=0;
758
759         lock_adapter_irq(&wandev->lock, &smp_flags);
760         dev = wandev->dev;
761         prev = NULL;
762         while (dev && strcmp(name, dev->name)) {
763                 struct net_device **slave = dev->priv;
764                 prev = dev;
765                 dev = *slave;
766         }
767         unlock_adapter_irq(&wandev->lock, &smp_flags);
768
769         if (dev == NULL)
770                 return -ENODEV; /* interface not found */
771
772         if (netif_running(dev))
773                 return -EBUSY;  /* interface in use */
774
775         if (wandev->del_if)
776                 wandev->del_if(wandev, dev);
777
778         lock_adapter_irq(&wandev->lock, &smp_flags);
779         if (prev) {
780                 struct net_device **prev_slave = prev->priv;
781                 struct net_device **slave = dev->priv;
782
783                 *prev_slave = *slave;
784         } else {
785                 struct net_device **slave = dev->priv;
786                 wandev->dev = *slave;
787         }
788         --wandev->ndev;
789         unlock_adapter_irq(&wandev->lock, &smp_flags);
790
791         printk(KERN_INFO "%s: unregistering '%s'\n", wandev->name, dev->name);
792
793         /* Due to new interface linking method using dev->priv,
794          * this code has moved from del_if() function.*/
795         kfree(dev->priv);
796         dev->priv=NULL;
797
798         unregister_netdev(dev);
799
800         free_netdev(dev);
801
802         return 0;
803 }
804
805 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
806 {
807         spin_lock_irqsave(lock, *smp_flags);
808 }
809
810
811 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
812 {
813         spin_unlock_irqrestore(lock, *smp_flags);
814 }
815
816 EXPORT_SYMBOL(register_wan_device);
817 EXPORT_SYMBOL(unregister_wan_device);
818
819 MODULE_LICENSE("GPL");
820
821 /*
822  *      End
823  */