[NET]: Make /proc/net per network namespace
[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/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 int wanrouter_ioctl(struct inode *inode, struct file *file,
354                 unsigned int cmd, unsigned long arg)
355 {
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         switch (cmd) {
376         case ROUTER_SETUP:
377                 err = wanrouter_device_setup(wandev, data);
378                 break;
379
380         case ROUTER_DOWN:
381                 err = wanrouter_device_shutdown(wandev);
382                 break;
383
384         case ROUTER_STAT:
385                 err = wanrouter_device_stat(wandev, data);
386                 break;
387
388         case ROUTER_IFNEW:
389                 err = wanrouter_device_new_if(wandev, data);
390                 break;
391
392         case ROUTER_IFDEL:
393                 err = wanrouter_device_del_if(wandev, data);
394                 break;
395
396         case ROUTER_IFSTAT:
397                 break;
398
399         default:
400                 if ((cmd >= ROUTER_USER) &&
401                     (cmd <= ROUTER_USER_MAX) &&
402                     wandev->ioctl)
403                         err = wandev->ioctl(wandev, cmd, arg);
404                 else err = -EINVAL;
405         }
406         return err;
407 }
408
409 /*
410  *      WAN Driver IOCTL Handlers
411  */
412
413 /*
414  *      Setup WAN link device.
415  *      o verify user address space
416  *      o allocate kernel memory and copy configuration data to kernel space
417  *      o if configuration data includes extension, copy it to kernel space too
418  *      o call driver's setup() entry point
419  */
420
421 static int wanrouter_device_setup(struct wan_device *wandev,
422                                   wandev_conf_t __user *u_conf)
423 {
424         void *data = NULL;
425         wandev_conf_t *conf;
426         int err = -EINVAL;
427
428         if (wandev->setup == NULL) {    /* Nothing to do ? */
429                 printk(KERN_INFO "%s: ERROR, No setup script: wandev->setup()\n",
430                                 wandev->name);
431                 return 0;
432         }
433
434         conf = kmalloc(sizeof(wandev_conf_t), GFP_KERNEL);
435         if (conf == NULL){
436                 printk(KERN_INFO "%s: ERROR, Failed to allocate kernel memory !\n",
437                                 wandev->name);
438                 return -ENOBUFS;
439         }
440
441         if (copy_from_user(conf, u_conf, sizeof(wandev_conf_t))) {
442                 printk(KERN_INFO "%s: Failed to copy user config data to kernel space!\n",
443                                 wandev->name);
444                 kfree(conf);
445                 return -EFAULT;
446         }
447
448         if (conf->magic != ROUTER_MAGIC) {
449                 kfree(conf);
450                 printk(KERN_INFO "%s: ERROR, Invalid MAGIC Number\n",
451                                 wandev->name);
452                 return -EINVAL;
453         }
454
455         if (conf->data_size && conf->data) {
456                 if (conf->data_size > 128000) {
457                         printk(KERN_INFO
458                             "%s: ERROR, Invalid firmware data size %i !\n",
459                                         wandev->name, conf->data_size);
460                         kfree(conf);
461                         return -EINVAL;
462                 }
463
464                 data = vmalloc(conf->data_size);
465                 if (!data) {
466                         printk(KERN_INFO
467                                 "%s: ERROR, Faild allocate kernel memory !\n",
468                                 wandev->name);
469                         kfree(conf);
470                         return -ENOBUFS;
471                 }
472                 if (!copy_from_user(data, conf->data, conf->data_size)) {
473                         conf->data = data;
474                         err = wandev->setup(wandev, conf);
475                 } else {
476                         printk(KERN_INFO
477                              "%s: ERROR, Faild to copy from user data !\n",
478                                wandev->name);
479                         err = -EFAULT;
480                 }
481                 vfree(data);
482         } else {
483                 printk(KERN_INFO
484                     "%s: ERROR, No firmware found ! Firmware size = %i !\n",
485                                 wandev->name, conf->data_size);
486         }
487
488         kfree(conf);
489         return err;
490 }
491
492 /*
493  *      Shutdown WAN device.
494  *      o delete all not opened logical channels for this device
495  *      o call driver's shutdown() entry point
496  */
497
498 static int wanrouter_device_shutdown(struct wan_device *wandev)
499 {
500         struct net_device *dev;
501         int err=0;
502
503         if (wandev->state == WAN_UNCONFIGURED)
504                 return 0;
505
506         printk(KERN_INFO "\n%s: Shutting Down!\n",wandev->name);
507
508         for (dev = wandev->dev; dev;) {
509                 err = wanrouter_delete_interface(wandev, dev->name);
510                 if (err)
511                         return err;
512                 /* The above function deallocates the current dev
513                  * structure. Therefore, we cannot use dev->priv
514                  * as the next element: wandev->dev points to the
515                  * next element */
516                 dev = wandev->dev;
517         }
518
519         if (wandev->ndev)
520                 return -EBUSY;  /* there are opened interfaces  */
521
522         if (wandev->shutdown)
523                 err=wandev->shutdown(wandev);
524
525         return err;
526 }
527
528 /*
529  *      Get WAN device status & statistics.
530  */
531
532 static int wanrouter_device_stat(struct wan_device *wandev,
533                                  wandev_stat_t __user *u_stat)
534 {
535         wandev_stat_t stat;
536
537         memset(&stat, 0, sizeof(stat));
538
539         /* Ask device driver to update device statistics */
540         if ((wandev->state != WAN_UNCONFIGURED) && wandev->update)
541                 wandev->update(wandev);
542
543         /* Fill out structure */
544         stat.ndev  = wandev->ndev;
545         stat.state = wandev->state;
546
547         if (copy_to_user(u_stat, &stat, sizeof(stat)))
548                 return -EFAULT;
549
550         return 0;
551 }
552
553 /*
554  *      Create new WAN interface.
555  *      o verify user address space
556  *      o copy configuration data to kernel address space
557  *      o allocate network interface data space
558  *      o call driver's new_if() entry point
559  *      o make sure there is no interface name conflict
560  *      o register network interface
561  */
562
563 static int wanrouter_device_new_if(struct wan_device *wandev,
564                                    wanif_conf_t __user *u_conf)
565 {
566         wanif_conf_t *cnf;
567         struct net_device *dev = NULL;
568 #ifdef CONFIG_WANPIPE_MULTPPP
569         struct ppp_device *pppdev=NULL;
570 #endif
571         int err;
572
573         if ((wandev->state == WAN_UNCONFIGURED) || (wandev->new_if == NULL))
574                 return -ENODEV;
575
576         cnf = kmalloc(sizeof(wanif_conf_t), GFP_KERNEL);
577         if (!cnf)
578                 return -ENOBUFS;
579
580         err = -EFAULT;
581         if (copy_from_user(cnf, u_conf, sizeof(wanif_conf_t)))
582                 goto out;
583
584         err = -EINVAL;
585         if (cnf->magic != ROUTER_MAGIC)
586                 goto out;
587
588         if (cnf->config_id == WANCONFIG_MPPP) {
589 #ifdef CONFIG_WANPIPE_MULTPPP
590                 pppdev = kzalloc(sizeof(struct ppp_device), GFP_KERNEL);
591                 err = -ENOBUFS;
592                 if (pppdev == NULL)
593                         goto out;
594                 pppdev->dev = kzalloc(sizeof(struct net_device), GFP_KERNEL);
595                 if (pppdev->dev == NULL) {
596                         kfree(pppdev);
597                         err = -ENOBUFS;
598                         goto out;
599                 }
600                 err = wandev->new_if(wandev, (struct net_device *)pppdev, cnf);
601                 dev = pppdev->dev;
602 #else
603                 printk(KERN_INFO "%s: Wanpipe Mulit-Port PPP support has not been compiled in!\n",
604                                 wandev->name);
605                 err = -EPROTONOSUPPORT;
606                 goto out;
607 #endif
608         } else {
609                 dev = kzalloc(sizeof(struct net_device), GFP_KERNEL);
610                 err = -ENOBUFS;
611                 if (dev == NULL)
612                         goto out;
613                 err = wandev->new_if(wandev, dev, cnf);
614         }
615
616         if (!err) {
617                 /* Register network interface. This will invoke init()
618                  * function supplied by the driver.  If device registered
619                  * successfully, add it to the interface list.
620                  */
621
622                 if (dev->name == NULL) {
623                         err = -EINVAL;
624                 } else {
625
626                         #ifdef WANDEBUG
627                         printk(KERN_INFO "%s: registering interface %s...\n",
628                                 wanrouter_modname, dev->name);
629                         #endif
630
631                         err = register_netdev(dev);
632                         if (!err) {
633                                 struct net_device *slave = NULL;
634                                 unsigned long smp_flags=0;
635
636                                 lock_adapter_irq(&wandev->lock, &smp_flags);
637
638                                 if (wandev->dev == NULL) {
639                                         wandev->dev = dev;
640                                 } else {
641                                         for (slave=wandev->dev;
642                                          *((struct net_device **)slave->priv);
643                                  slave = *((struct net_device **)slave->priv));
644
645                                      *((struct net_device **)slave->priv) = dev;
646                                 }
647                                 ++wandev->ndev;
648
649                                 unlock_adapter_irq(&wandev->lock, &smp_flags);
650                                 err = 0;        /* done !!! */
651                                 goto out;
652                         }
653                 }
654                 if (wandev->del_if)
655                         wandev->del_if(wandev, dev);
656         }
657
658         /* This code has moved from del_if() function */
659         kfree(dev->priv);
660         dev->priv = NULL;
661
662 #ifdef CONFIG_WANPIPE_MULTPPP
663         if (cnf->config_id == WANCONFIG_MPPP)
664                 kfree(pppdev);
665         else
666                 kfree(dev);
667 #else
668         /* Sync PPP is disabled */
669         if (cnf->config_id != WANCONFIG_MPPP)
670                 kfree(dev);
671 #endif
672
673 out:
674         kfree(cnf);
675         return err;
676 }
677
678
679 /*
680  *      Delete WAN logical channel.
681  *       o verify user address space
682  *       o copy configuration data to kernel address space
683  */
684
685 static int wanrouter_device_del_if(struct wan_device *wandev, char __user *u_name)
686 {
687         char name[WAN_IFNAME_SZ + 1];
688         int err = 0;
689
690         if (wandev->state == WAN_UNCONFIGURED)
691                 return -ENODEV;
692
693         memset(name, 0, sizeof(name));
694
695         if (copy_from_user(name, u_name, WAN_IFNAME_SZ))
696                 return -EFAULT;
697
698         err = wanrouter_delete_interface(wandev, name);
699         if (err)
700                 return err;
701
702         /* If last interface being deleted, shutdown card
703          * This helps with administration at leaf nodes
704          * (You can tell if the person at the other end of the phone
705          * has an interface configured) and avoids DoS vulnerabilities
706          * in binary driver files - this fixes a problem with the current
707          * Sangoma driver going into strange states when all the network
708          * interfaces are deleted and the link irrecoverably disconnected.
709          */
710
711         if (!wandev->ndev && wandev->shutdown)
712                 err = wandev->shutdown(wandev);
713
714         return err;
715 }
716
717 /*
718  *      Miscellaneous Functions
719  */
720
721 /*
722  *      Find WAN device by name.
723  *      Return pointer to the WAN device data space or NULL if device not found.
724  */
725
726 static struct wan_device *wanrouter_find_device(char *name)
727 {
728         struct wan_device *wandev;
729
730         for (wandev = wanrouter_router_devlist;
731              wandev && strcmp(wandev->name, name);
732                 wandev = wandev->next);
733         return wandev;
734 }
735
736 /*
737  *      Delete WAN logical channel identified by its name.
738  *      o find logical channel by its name
739  *      o call driver's del_if() entry point
740  *      o unregister network interface
741  *      o unlink channel data space from linked list of channels
742  *      o release channel data space
743  *
744  *      Return: 0               success
745  *              -ENODEV         channel not found.
746  *              -EBUSY          interface is open
747  *
748  *      Note: If (force != 0), then device will be destroyed even if interface
749  *      associated with it is open. It's caller's responsibility to make
750  *      sure that opened interfaces are not removed!
751  */
752
753 static int wanrouter_delete_interface(struct wan_device *wandev, char *name)
754 {
755         struct net_device *dev = NULL, *prev = NULL;
756         unsigned long smp_flags=0;
757
758         lock_adapter_irq(&wandev->lock, &smp_flags);
759         dev = wandev->dev;
760         prev = NULL;
761         while (dev && strcmp(name, dev->name)) {
762                 struct net_device **slave = dev->priv;
763                 prev = dev;
764                 dev = *slave;
765         }
766         unlock_adapter_irq(&wandev->lock, &smp_flags);
767
768         if (dev == NULL)
769                 return -ENODEV; /* interface not found */
770
771         if (netif_running(dev))
772                 return -EBUSY;  /* interface in use */
773
774         if (wandev->del_if)
775                 wandev->del_if(wandev, dev);
776
777         lock_adapter_irq(&wandev->lock, &smp_flags);
778         if (prev) {
779                 struct net_device **prev_slave = prev->priv;
780                 struct net_device **slave = dev->priv;
781
782                 *prev_slave = *slave;
783         } else {
784                 struct net_device **slave = dev->priv;
785                 wandev->dev = *slave;
786         }
787         --wandev->ndev;
788         unlock_adapter_irq(&wandev->lock, &smp_flags);
789
790         printk(KERN_INFO "%s: unregistering '%s'\n", wandev->name, dev->name);
791
792         /* Due to new interface linking method using dev->priv,
793          * this code has moved from del_if() function.*/
794         kfree(dev->priv);
795         dev->priv=NULL;
796
797         unregister_netdev(dev);
798
799         free_netdev(dev);
800
801         return 0;
802 }
803
804 static void lock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
805 {
806         spin_lock_irqsave(lock, *smp_flags);
807 }
808
809
810 static void unlock_adapter_irq(spinlock_t *lock, unsigned long *smp_flags)
811 {
812         spin_unlock_irqrestore(lock, *smp_flags);
813 }
814
815 EXPORT_SYMBOL(register_wan_device);
816 EXPORT_SYMBOL(unregister_wan_device);
817
818 MODULE_LICENSE("GPL");
819
820 /*
821  *      End
822  */