[NET]: Rework dev_base via list_head (v3)
[linux-2.6.git] / net / netrom / nr_route.c
1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License as published by
4  * the Free Software Foundation; either version 2 of the License, or
5  * (at your option) any later version.
6  *
7  * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8  * Copyright Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
9  * Copyright Tomi Manninen OH2BNS (oh2bns@sral.fi)
10  */
11 #include <linux/errno.h>
12 #include <linux/types.h>
13 #include <linux/socket.h>
14 #include <linux/in.h>
15 #include <linux/kernel.h>
16 #include <linux/timer.h>
17 #include <linux/string.h>
18 #include <linux/sockios.h>
19 #include <linux/net.h>
20 #include <net/ax25.h>
21 #include <linux/inet.h>
22 #include <linux/netdevice.h>
23 #include <net/arp.h>
24 #include <linux/if_arp.h>
25 #include <linux/skbuff.h>
26 #include <net/sock.h>
27 #include <asm/uaccess.h>
28 #include <asm/system.h>
29 #include <linux/fcntl.h>
30 #include <linux/termios.h>      /* For TIOCINQ/OUTQ */
31 #include <linux/mm.h>
32 #include <linux/interrupt.h>
33 #include <linux/notifier.h>
34 #include <linux/netfilter.h>
35 #include <linux/init.h>
36 #include <linux/spinlock.h>
37 #include <net/netrom.h>
38 #include <linux/seq_file.h>
39
40 static unsigned int nr_neigh_no = 1;
41
42 static HLIST_HEAD(nr_node_list);
43 static DEFINE_SPINLOCK(nr_node_list_lock);
44 static HLIST_HEAD(nr_neigh_list);
45 static DEFINE_SPINLOCK(nr_neigh_list_lock);
46
47 static struct nr_node *nr_node_get(ax25_address *callsign)
48 {
49         struct nr_node *found = NULL;
50         struct nr_node *nr_node;
51         struct hlist_node *node;
52
53         spin_lock_bh(&nr_node_list_lock);
54         nr_node_for_each(nr_node, node, &nr_node_list)
55                 if (ax25cmp(callsign, &nr_node->callsign) == 0) {
56                         nr_node_hold(nr_node);
57                         found = nr_node;
58                         break;
59                 }
60         spin_unlock_bh(&nr_node_list_lock);
61         return found;
62 }
63
64 static struct nr_neigh *nr_neigh_get_dev(ax25_address *callsign,
65                                          struct net_device *dev)
66 {
67         struct nr_neigh *found = NULL;
68         struct nr_neigh *nr_neigh;
69         struct hlist_node *node;
70
71         spin_lock_bh(&nr_neigh_list_lock);
72         nr_neigh_for_each(nr_neigh, node, &nr_neigh_list)
73                 if (ax25cmp(callsign, &nr_neigh->callsign) == 0 &&
74                     nr_neigh->dev == dev) {
75                         nr_neigh_hold(nr_neigh);
76                         found = nr_neigh;
77                         break;
78                 }
79         spin_unlock_bh(&nr_neigh_list_lock);
80         return found;
81 }
82
83 static void nr_remove_neigh(struct nr_neigh *);
84
85 /*
86  *      Add a new route to a node, and in the process add the node and the
87  *      neighbour if it is new.
88  */
89 static int __must_check nr_add_node(ax25_address *nr, const char *mnemonic,
90         ax25_address *ax25, ax25_digi *ax25_digi, struct net_device *dev,
91         int quality, int obs_count)
92 {
93         struct nr_node  *nr_node;
94         struct nr_neigh *nr_neigh;
95         struct nr_route nr_route;
96         int i, found;
97         struct net_device *odev;
98
99         if ((odev=nr_dev_get(nr)) != NULL) {    /* Can't add routes to ourself */
100                 dev_put(odev);
101                 return -EINVAL;
102         }
103
104         nr_node = nr_node_get(nr);
105
106         nr_neigh = nr_neigh_get_dev(ax25, dev);
107
108         /*
109          * The L2 link to a neighbour has failed in the past
110          * and now a frame comes from this neighbour. We assume
111          * it was a temporary trouble with the link and reset the
112          * routes now (and not wait for a node broadcast).
113          */
114         if (nr_neigh != NULL && nr_neigh->failed != 0 && quality == 0) {
115                 struct nr_node *nr_nodet;
116                 struct hlist_node *node;
117
118                 spin_lock_bh(&nr_node_list_lock);
119                 nr_node_for_each(nr_nodet, node, &nr_node_list) {
120                         nr_node_lock(nr_nodet);
121                         for (i = 0; i < nr_nodet->count; i++)
122                                 if (nr_nodet->routes[i].neighbour == nr_neigh)
123                                         if (i < nr_nodet->which)
124                                                 nr_nodet->which = i;
125                         nr_node_unlock(nr_nodet);
126                 }
127                 spin_unlock_bh(&nr_node_list_lock);
128         }
129
130         if (nr_neigh != NULL)
131                 nr_neigh->failed = 0;
132
133         if (quality == 0 && nr_neigh != NULL && nr_node != NULL) {
134                 nr_neigh_put(nr_neigh);
135                 nr_node_put(nr_node);
136                 return 0;
137         }
138
139         if (nr_neigh == NULL) {
140                 if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL) {
141                         if (nr_node)
142                                 nr_node_put(nr_node);
143                         return -ENOMEM;
144                 }
145
146                 nr_neigh->callsign = *ax25;
147                 nr_neigh->digipeat = NULL;
148                 nr_neigh->ax25     = NULL;
149                 nr_neigh->dev      = dev;
150                 nr_neigh->quality  = sysctl_netrom_default_path_quality;
151                 nr_neigh->locked   = 0;
152                 nr_neigh->count    = 0;
153                 nr_neigh->number   = nr_neigh_no++;
154                 nr_neigh->failed   = 0;
155                 atomic_set(&nr_neigh->refcount, 1);
156
157                 if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
158                         nr_neigh->digipeat = kmemdup(ax25_digi,
159                                                      sizeof(*ax25_digi),
160                                                      GFP_KERNEL);
161                         if (nr_neigh->digipeat == NULL) {
162                                 kfree(nr_neigh);
163                                 if (nr_node)
164                                         nr_node_put(nr_node);
165                                 return -ENOMEM;
166                         }
167                 }
168
169                 spin_lock_bh(&nr_neigh_list_lock);
170                 hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
171                 nr_neigh_hold(nr_neigh);
172                 spin_unlock_bh(&nr_neigh_list_lock);
173         }
174
175         if (quality != 0 && ax25cmp(nr, ax25) == 0 && !nr_neigh->locked)
176                 nr_neigh->quality = quality;
177
178         if (nr_node == NULL) {
179                 if ((nr_node = kmalloc(sizeof(*nr_node), GFP_ATOMIC)) == NULL) {
180                         if (nr_neigh)
181                                 nr_neigh_put(nr_neigh);
182                         return -ENOMEM;
183                 }
184
185                 nr_node->callsign = *nr;
186                 strcpy(nr_node->mnemonic, mnemonic);
187
188                 nr_node->which = 0;
189                 nr_node->count = 1;
190                 atomic_set(&nr_node->refcount, 1);
191                 spin_lock_init(&nr_node->node_lock);
192
193                 nr_node->routes[0].quality   = quality;
194                 nr_node->routes[0].obs_count = obs_count;
195                 nr_node->routes[0].neighbour = nr_neigh;
196
197                 nr_neigh_hold(nr_neigh);
198                 nr_neigh->count++;
199
200                 spin_lock_bh(&nr_node_list_lock);
201                 hlist_add_head(&nr_node->node_node, &nr_node_list);
202                 /* refcount initialized at 1 */
203                 spin_unlock_bh(&nr_node_list_lock);
204
205                 return 0;
206         }
207         nr_node_lock(nr_node);
208
209         if (quality != 0)
210                 strcpy(nr_node->mnemonic, mnemonic);
211
212         for (found = 0, i = 0; i < nr_node->count; i++) {
213                 if (nr_node->routes[i].neighbour == nr_neigh) {
214                         nr_node->routes[i].quality   = quality;
215                         nr_node->routes[i].obs_count = obs_count;
216                         found = 1;
217                         break;
218                 }
219         }
220
221         if (!found) {
222                 /* We have space at the bottom, slot it in */
223                 if (nr_node->count < 3) {
224                         nr_node->routes[2] = nr_node->routes[1];
225                         nr_node->routes[1] = nr_node->routes[0];
226
227                         nr_node->routes[0].quality   = quality;
228                         nr_node->routes[0].obs_count = obs_count;
229                         nr_node->routes[0].neighbour = nr_neigh;
230
231                         nr_node->which++;
232                         nr_node->count++;
233                         nr_neigh_hold(nr_neigh);
234                         nr_neigh->count++;
235                 } else {
236                         /* It must be better than the worst */
237                         if (quality > nr_node->routes[2].quality) {
238                                 nr_node->routes[2].neighbour->count--;
239                                 nr_neigh_put(nr_node->routes[2].neighbour);
240
241                                 if (nr_node->routes[2].neighbour->count == 0 && !nr_node->routes[2].neighbour->locked)
242                                         nr_remove_neigh(nr_node->routes[2].neighbour);
243
244                                 nr_node->routes[2].quality   = quality;
245                                 nr_node->routes[2].obs_count = obs_count;
246                                 nr_node->routes[2].neighbour = nr_neigh;
247
248                                 nr_neigh_hold(nr_neigh);
249                                 nr_neigh->count++;
250                         }
251                 }
252         }
253
254         /* Now re-sort the routes in quality order */
255         switch (nr_node->count) {
256         case 3:
257                 if (nr_node->routes[1].quality > nr_node->routes[0].quality) {
258                         switch (nr_node->which) {
259                                 case 0:  nr_node->which = 1; break;
260                                 case 1:  nr_node->which = 0; break;
261                                 default: break;
262                         }
263                         nr_route           = nr_node->routes[0];
264                         nr_node->routes[0] = nr_node->routes[1];
265                         nr_node->routes[1] = nr_route;
266                 }
267                 if (nr_node->routes[2].quality > nr_node->routes[1].quality) {
268                         switch (nr_node->which) {
269                         case 1:  nr_node->which = 2;
270                                 break;
271
272                         case 2:  nr_node->which = 1;
273                                 break;
274
275                         default:
276                                 break;
277                         }
278                         nr_route           = nr_node->routes[1];
279                         nr_node->routes[1] = nr_node->routes[2];
280                         nr_node->routes[2] = nr_route;
281                 }
282         case 2:
283                 if (nr_node->routes[1].quality > nr_node->routes[0].quality) {
284                         switch (nr_node->which) {
285                         case 0:  nr_node->which = 1;
286                                 break;
287
288                         case 1:  nr_node->which = 0;
289                                 break;
290
291                         default: break;
292                         }
293                         nr_route           = nr_node->routes[0];
294                         nr_node->routes[0] = nr_node->routes[1];
295                         nr_node->routes[1] = nr_route;
296                         }
297         case 1:
298                 break;
299         }
300
301         for (i = 0; i < nr_node->count; i++) {
302                 if (nr_node->routes[i].neighbour == nr_neigh) {
303                         if (i < nr_node->which)
304                                 nr_node->which = i;
305                         break;
306                 }
307         }
308
309         nr_neigh_put(nr_neigh);
310         nr_node_unlock(nr_node);
311         nr_node_put(nr_node);
312         return 0;
313 }
314
315 static inline void __nr_remove_node(struct nr_node *nr_node)
316 {
317         hlist_del_init(&nr_node->node_node);
318         nr_node_put(nr_node);
319 }
320
321 #define nr_remove_node_locked(__node) \
322         __nr_remove_node(__node)
323
324 static void nr_remove_node(struct nr_node *nr_node)
325 {
326         spin_lock_bh(&nr_node_list_lock);
327         __nr_remove_node(nr_node);
328         spin_unlock_bh(&nr_node_list_lock);
329 }
330
331 static inline void __nr_remove_neigh(struct nr_neigh *nr_neigh)
332 {
333         hlist_del_init(&nr_neigh->neigh_node);
334         nr_neigh_put(nr_neigh);
335 }
336
337 #define nr_remove_neigh_locked(__neigh) \
338         __nr_remove_neigh(__neigh)
339
340 static void nr_remove_neigh(struct nr_neigh *nr_neigh)
341 {
342         spin_lock_bh(&nr_neigh_list_lock);
343         __nr_remove_neigh(nr_neigh);
344         spin_unlock_bh(&nr_neigh_list_lock);
345 }
346
347 /*
348  *      "Delete" a node. Strictly speaking remove a route to a node. The node
349  *      is only deleted if no routes are left to it.
350  */
351 static int nr_del_node(ax25_address *callsign, ax25_address *neighbour, struct net_device *dev)
352 {
353         struct nr_node  *nr_node;
354         struct nr_neigh *nr_neigh;
355         int i;
356
357         nr_node = nr_node_get(callsign);
358
359         if (nr_node == NULL)
360                 return -EINVAL;
361
362         nr_neigh = nr_neigh_get_dev(neighbour, dev);
363
364         if (nr_neigh == NULL) {
365                 nr_node_put(nr_node);
366                 return -EINVAL;
367         }
368
369         nr_node_lock(nr_node);
370         for (i = 0; i < nr_node->count; i++) {
371                 if (nr_node->routes[i].neighbour == nr_neigh) {
372                         nr_neigh->count--;
373                         nr_neigh_put(nr_neigh);
374
375                         if (nr_neigh->count == 0 && !nr_neigh->locked)
376                                 nr_remove_neigh(nr_neigh);
377                         nr_neigh_put(nr_neigh);
378
379                         nr_node->count--;
380
381                         if (nr_node->count == 0) {
382                                 nr_remove_node(nr_node);
383                         } else {
384                                 switch (i) {
385                                 case 0:
386                                         nr_node->routes[0] = nr_node->routes[1];
387                                 case 1:
388                                         nr_node->routes[1] = nr_node->routes[2];
389                                 case 2:
390                                         break;
391                                 }
392                                 nr_node_put(nr_node);
393                         }
394                         nr_node_unlock(nr_node);
395
396                         return 0;
397                 }
398         }
399         nr_neigh_put(nr_neigh);
400         nr_node_unlock(nr_node);
401         nr_node_put(nr_node);
402
403         return -EINVAL;
404 }
405
406 /*
407  *      Lock a neighbour with a quality.
408  */
409 static int __must_check nr_add_neigh(ax25_address *callsign,
410         ax25_digi *ax25_digi, struct net_device *dev, unsigned int quality)
411 {
412         struct nr_neigh *nr_neigh;
413
414         nr_neigh = nr_neigh_get_dev(callsign, dev);
415         if (nr_neigh) {
416                 nr_neigh->quality = quality;
417                 nr_neigh->locked  = 1;
418                 nr_neigh_put(nr_neigh);
419                 return 0;
420         }
421
422         if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL)
423                 return -ENOMEM;
424
425         nr_neigh->callsign = *callsign;
426         nr_neigh->digipeat = NULL;
427         nr_neigh->ax25     = NULL;
428         nr_neigh->dev      = dev;
429         nr_neigh->quality  = quality;
430         nr_neigh->locked   = 1;
431         nr_neigh->count    = 0;
432         nr_neigh->number   = nr_neigh_no++;
433         nr_neigh->failed   = 0;
434         atomic_set(&nr_neigh->refcount, 1);
435
436         if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
437                 nr_neigh->digipeat = kmemdup(ax25_digi, sizeof(*ax25_digi),
438                                              GFP_KERNEL);
439                 if (nr_neigh->digipeat == NULL) {
440                         kfree(nr_neigh);
441                         return -ENOMEM;
442                 }
443         }
444
445         spin_lock_bh(&nr_neigh_list_lock);
446         hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
447         /* refcount is initialized at 1 */
448         spin_unlock_bh(&nr_neigh_list_lock);
449
450         return 0;
451 }
452
453 /*
454  *      "Delete" a neighbour. The neighbour is only removed if the number
455  *      of nodes that may use it is zero.
456  */
457 static int nr_del_neigh(ax25_address *callsign, struct net_device *dev, unsigned int quality)
458 {
459         struct nr_neigh *nr_neigh;
460
461         nr_neigh = nr_neigh_get_dev(callsign, dev);
462
463         if (nr_neigh == NULL) return -EINVAL;
464
465         nr_neigh->quality = quality;
466         nr_neigh->locked  = 0;
467
468         if (nr_neigh->count == 0)
469                 nr_remove_neigh(nr_neigh);
470         nr_neigh_put(nr_neigh);
471
472         return 0;
473 }
474
475 /*
476  *      Decrement the obsolescence count by one. If a route is reduced to a
477  *      count of zero, remove it. Also remove any unlocked neighbours with
478  *      zero nodes routing via it.
479  */
480 static int nr_dec_obs(void)
481 {
482         struct nr_neigh *nr_neigh;
483         struct nr_node  *s;
484         struct hlist_node *node, *nodet;
485         int i;
486
487         spin_lock_bh(&nr_node_list_lock);
488         nr_node_for_each_safe(s, node, nodet, &nr_node_list) {
489                 nr_node_lock(s);
490                 for (i = 0; i < s->count; i++) {
491                         switch (s->routes[i].obs_count) {
492                         case 0:         /* A locked entry */
493                                 break;
494
495                         case 1:         /* From 1 -> 0 */
496                                 nr_neigh = s->routes[i].neighbour;
497
498                                 nr_neigh->count--;
499                                 nr_neigh_put(nr_neigh);
500
501                                 if (nr_neigh->count == 0 && !nr_neigh->locked)
502                                         nr_remove_neigh(nr_neigh);
503
504                                 s->count--;
505
506                                 switch (i) {
507                                         case 0:
508                                                 s->routes[0] = s->routes[1];
509                                         case 1:
510                                                 s->routes[1] = s->routes[2];
511                                         case 2:
512                                                 break;
513                                 }
514                                 break;
515
516                         default:
517                                 s->routes[i].obs_count--;
518                                 break;
519
520                         }
521                 }
522
523                 if (s->count <= 0)
524                         nr_remove_node_locked(s);
525                 nr_node_unlock(s);
526         }
527         spin_unlock_bh(&nr_node_list_lock);
528
529         return 0;
530 }
531
532 /*
533  *      A device has been removed. Remove its routes and neighbours.
534  */
535 void nr_rt_device_down(struct net_device *dev)
536 {
537         struct nr_neigh *s;
538         struct hlist_node *node, *nodet, *node2, *node2t;
539         struct nr_node  *t;
540         int i;
541
542         spin_lock_bh(&nr_neigh_list_lock);
543         nr_neigh_for_each_safe(s, node, nodet, &nr_neigh_list) {
544                 if (s->dev == dev) {
545                         spin_lock_bh(&nr_node_list_lock);
546                         nr_node_for_each_safe(t, node2, node2t, &nr_node_list) {
547                                 nr_node_lock(t);
548                                 for (i = 0; i < t->count; i++) {
549                                         if (t->routes[i].neighbour == s) {
550                                                 t->count--;
551
552                                                 switch (i) {
553                                                 case 0:
554                                                         t->routes[0] = t->routes[1];
555                                                 case 1:
556                                                         t->routes[1] = t->routes[2];
557                                                 case 2:
558                                                         break;
559                                                 }
560                                         }
561                                 }
562
563                                 if (t->count <= 0)
564                                         nr_remove_node_locked(t);
565                                 nr_node_unlock(t);
566                         }
567                         spin_unlock_bh(&nr_node_list_lock);
568
569                         nr_remove_neigh_locked(s);
570                 }
571         }
572         spin_unlock_bh(&nr_neigh_list_lock);
573 }
574
575 /*
576  *      Check that the device given is a valid AX.25 interface that is "up".
577  *      Or a valid ethernet interface with an AX.25 callsign binding.
578  */
579 static struct net_device *nr_ax25_dev_get(char *devname)
580 {
581         struct net_device *dev;
582
583         if ((dev = dev_get_by_name(devname)) == NULL)
584                 return NULL;
585
586         if ((dev->flags & IFF_UP) && dev->type == ARPHRD_AX25)
587                 return dev;
588
589         dev_put(dev);
590         return NULL;
591 }
592
593 /*
594  *      Find the first active NET/ROM device, usually "nr0".
595  */
596 struct net_device *nr_dev_first(void)
597 {
598         struct net_device *dev, *first = NULL;
599
600         read_lock(&dev_base_lock);
601         for_each_netdev(dev) {
602                 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM)
603                         if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
604                                 first = dev;
605         }
606         if (first)
607                 dev_hold(first);
608         read_unlock(&dev_base_lock);
609
610         return first;
611 }
612
613 /*
614  *      Find the NET/ROM device for the given callsign.
615  */
616 struct net_device *nr_dev_get(ax25_address *addr)
617 {
618         struct net_device *dev;
619
620         read_lock(&dev_base_lock);
621         for_each_netdev(dev) {
622                 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM && ax25cmp(addr, (ax25_address *)dev->dev_addr) == 0) {
623                         dev_hold(dev);
624                         goto out;
625                 }
626         }
627         dev = NULL;
628 out:
629         read_unlock(&dev_base_lock);
630         return dev;
631 }
632
633 static ax25_digi *nr_call_to_digi(int ndigis, ax25_address *digipeaters)
634 {
635         static ax25_digi ax25_digi;
636         int i;
637
638         if (ndigis == 0)
639                 return NULL;
640
641         for (i = 0; i < ndigis; i++) {
642                 ax25_digi.calls[i]    = digipeaters[i];
643                 ax25_digi.repeated[i] = 0;
644         }
645
646         ax25_digi.ndigi      = ndigis;
647         ax25_digi.lastrepeat = -1;
648
649         return &ax25_digi;
650 }
651
652 /*
653  *      Handle the ioctls that control the routing functions.
654  */
655 int nr_rt_ioctl(unsigned int cmd, void __user *arg)
656 {
657         struct nr_route_struct nr_route;
658         struct net_device *dev;
659         int ret;
660
661         switch (cmd) {
662         case SIOCADDRT:
663                 if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
664                         return -EFAULT;
665                 if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
666                         return -EINVAL;
667                 if (nr_route.ndigis < 0 || nr_route.ndigis > AX25_MAX_DIGIS) {
668                         dev_put(dev);
669                         return -EINVAL;
670                 }
671                 switch (nr_route.type) {
672                 case NETROM_NODE:
673                         ret = nr_add_node(&nr_route.callsign,
674                                 nr_route.mnemonic,
675                                 &nr_route.neighbour,
676                                 nr_call_to_digi(nr_route.ndigis, nr_route.digipeaters),
677                                 dev, nr_route.quality,
678                                 nr_route.obs_count);
679                         break;
680                 case NETROM_NEIGH:
681                         ret = nr_add_neigh(&nr_route.callsign,
682                                 nr_call_to_digi(nr_route.ndigis, nr_route.digipeaters),
683                                 dev, nr_route.quality);
684                         break;
685                 default:
686                         ret = -EINVAL;
687                 }
688                 dev_put(dev);
689                 return ret;
690
691         case SIOCDELRT:
692                 if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
693                         return -EFAULT;
694                 if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
695                         return -EINVAL;
696                 switch (nr_route.type) {
697                 case NETROM_NODE:
698                         ret = nr_del_node(&nr_route.callsign,
699                                 &nr_route.neighbour, dev);
700                         break;
701                 case NETROM_NEIGH:
702                         ret = nr_del_neigh(&nr_route.callsign,
703                                 dev, nr_route.quality);
704                         break;
705                 default:
706                         ret = -EINVAL;
707                 }
708                 dev_put(dev);
709                 return ret;
710
711         case SIOCNRDECOBS:
712                 return nr_dec_obs();
713
714         default:
715                 return -EINVAL;
716         }
717
718         return 0;
719 }
720
721 /*
722  *      A level 2 link has timed out, therefore it appears to be a poor link,
723  *      then don't use that neighbour until it is reset.
724  */
725 void nr_link_failed(ax25_cb *ax25, int reason)
726 {
727         struct nr_neigh *s, *nr_neigh = NULL;
728         struct hlist_node *node;
729         struct nr_node  *nr_node = NULL;
730
731         spin_lock_bh(&nr_neigh_list_lock);
732         nr_neigh_for_each(s, node, &nr_neigh_list) {
733                 if (s->ax25 == ax25) {
734                         nr_neigh_hold(s);
735                         nr_neigh = s;
736                         break;
737                 }
738         }
739         spin_unlock_bh(&nr_neigh_list_lock);
740
741         if (nr_neigh == NULL)
742                 return;
743
744         nr_neigh->ax25 = NULL;
745         ax25_cb_put(ax25);
746
747         if (++nr_neigh->failed < sysctl_netrom_link_fails_count) {
748                 nr_neigh_put(nr_neigh);
749                 return;
750         }
751         spin_lock_bh(&nr_node_list_lock);
752         nr_node_for_each(nr_node, node, &nr_node_list) {
753                 nr_node_lock(nr_node);
754                 if (nr_node->which < nr_node->count &&
755                     nr_node->routes[nr_node->which].neighbour == nr_neigh)
756                         nr_node->which++;
757                 nr_node_unlock(nr_node);
758         }
759         spin_unlock_bh(&nr_node_list_lock);
760         nr_neigh_put(nr_neigh);
761 }
762
763 /*
764  *      Route a frame to an appropriate AX.25 connection. A NULL ax25_cb
765  *      indicates an internally generated frame.
766  */
767 int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
768 {
769         ax25_address *nr_src, *nr_dest;
770         struct nr_neigh *nr_neigh;
771         struct nr_node  *nr_node;
772         struct net_device *dev;
773         unsigned char *dptr;
774         ax25_cb *ax25s;
775         int ret;
776         struct sk_buff *skbn;
777
778
779         nr_src  = (ax25_address *)(skb->data + 0);
780         nr_dest = (ax25_address *)(skb->data + 7);
781
782         if (ax25 != NULL) {
783                 ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
784                                   ax25->ax25_dev->dev, 0,
785                                   sysctl_netrom_obsolescence_count_initialiser);
786                 if (ret)
787                         return ret;
788         }
789
790         if ((dev = nr_dev_get(nr_dest)) != NULL) {      /* Its for me */
791                 if (ax25 == NULL)                       /* Its from me */
792                         ret = nr_loopback_queue(skb);
793                 else
794                         ret = nr_rx_frame(skb, dev);
795                 dev_put(dev);
796                 return ret;
797         }
798
799         if (!sysctl_netrom_routing_control && ax25 != NULL)
800                 return 0;
801
802         /* Its Time-To-Live has expired */
803         if (skb->data[14] == 1) {
804                 return 0;
805         }
806
807         nr_node = nr_node_get(nr_dest);
808         if (nr_node == NULL)
809                 return 0;
810         nr_node_lock(nr_node);
811
812         if (nr_node->which >= nr_node->count) {
813                 nr_node_unlock(nr_node);
814                 nr_node_put(nr_node);
815                 return 0;
816         }
817
818         nr_neigh = nr_node->routes[nr_node->which].neighbour;
819
820         if ((dev = nr_dev_first()) == NULL) {
821                 nr_node_unlock(nr_node);
822                 nr_node_put(nr_node);
823                 return 0;
824         }
825
826         /* We are going to change the netrom headers so we should get our
827            own skb, we also did not know until now how much header space
828            we had to reserve... - RXQ */
829         if ((skbn=skb_copy_expand(skb, dev->hard_header_len, 0, GFP_ATOMIC)) == NULL) {
830                 nr_node_unlock(nr_node);
831                 nr_node_put(nr_node);
832                 dev_put(dev);
833                 return 0;
834         }
835         kfree_skb(skb);
836         skb=skbn;
837         skb->data[14]--;
838
839         dptr  = skb_push(skb, 1);
840         *dptr = AX25_P_NETROM;
841
842         ax25s = ax25_send_frame(skb, 256, (ax25_address *)dev->dev_addr, &nr_neigh->callsign, nr_neigh->digipeat, nr_neigh->dev);
843         if (nr_neigh->ax25 && ax25s) {
844                 /* We were already holding this ax25_cb */
845                 ax25_cb_put(ax25s);
846         }
847         nr_neigh->ax25 = ax25s;
848
849         dev_put(dev);
850         ret = (nr_neigh->ax25 != NULL);
851         nr_node_unlock(nr_node);
852         nr_node_put(nr_node);
853
854         return ret;
855 }
856
857 #ifdef CONFIG_PROC_FS
858
859 static void *nr_node_start(struct seq_file *seq, loff_t *pos)
860 {
861         struct nr_node *nr_node;
862         struct hlist_node *node;
863         int i = 1;
864
865         spin_lock_bh(&nr_node_list_lock);
866         if (*pos == 0)
867                 return SEQ_START_TOKEN;
868
869         nr_node_for_each(nr_node, node, &nr_node_list) {
870                 if (i == *pos)
871                         return nr_node;
872                 ++i;
873         }
874
875         return NULL;
876 }
877
878 static void *nr_node_next(struct seq_file *seq, void *v, loff_t *pos)
879 {
880         struct hlist_node *node;
881         ++*pos;
882
883         node = (v == SEQ_START_TOKEN)
884                 ? nr_node_list.first
885                 : ((struct nr_node *)v)->node_node.next;
886
887         return hlist_entry(node, struct nr_node, node_node);
888 }
889
890 static void nr_node_stop(struct seq_file *seq, void *v)
891 {
892         spin_unlock_bh(&nr_node_list_lock);
893 }
894
895 static int nr_node_show(struct seq_file *seq, void *v)
896 {
897         char buf[11];
898         int i;
899
900         if (v == SEQ_START_TOKEN)
901                 seq_puts(seq,
902                          "callsign  mnemonic w n qual obs neigh qual obs neigh qual obs neigh\n");
903         else {
904                 struct nr_node *nr_node = v;
905                 nr_node_lock(nr_node);
906                 seq_printf(seq, "%-9s %-7s  %d %d",
907                         ax2asc(buf, &nr_node->callsign),
908                         (nr_node->mnemonic[0] == '\0') ? "*" : nr_node->mnemonic,
909                         nr_node->which + 1,
910                         nr_node->count);
911
912                 for (i = 0; i < nr_node->count; i++) {
913                         seq_printf(seq, "  %3d   %d %05d",
914                                 nr_node->routes[i].quality,
915                                 nr_node->routes[i].obs_count,
916                                 nr_node->routes[i].neighbour->number);
917                 }
918                 nr_node_unlock(nr_node);
919
920                 seq_puts(seq, "\n");
921         }
922         return 0;
923 }
924
925 static struct seq_operations nr_node_seqops = {
926         .start = nr_node_start,
927         .next = nr_node_next,
928         .stop = nr_node_stop,
929         .show = nr_node_show,
930 };
931
932 static int nr_node_info_open(struct inode *inode, struct file *file)
933 {
934         return seq_open(file, &nr_node_seqops);
935 }
936
937 const struct file_operations nr_nodes_fops = {
938         .owner = THIS_MODULE,
939         .open = nr_node_info_open,
940         .read = seq_read,
941         .llseek = seq_lseek,
942         .release = seq_release,
943 };
944
945 static void *nr_neigh_start(struct seq_file *seq, loff_t *pos)
946 {
947         struct nr_neigh *nr_neigh;
948         struct hlist_node *node;
949         int i = 1;
950
951         spin_lock_bh(&nr_neigh_list_lock);
952         if (*pos == 0)
953                 return SEQ_START_TOKEN;
954
955         nr_neigh_for_each(nr_neigh, node, &nr_neigh_list) {
956                 if (i == *pos)
957                         return nr_neigh;
958         }
959         return NULL;
960 }
961
962 static void *nr_neigh_next(struct seq_file *seq, void *v, loff_t *pos)
963 {
964         struct hlist_node *node;
965         ++*pos;
966
967         node = (v == SEQ_START_TOKEN)
968                 ? nr_neigh_list.first
969                 : ((struct nr_neigh *)v)->neigh_node.next;
970
971         return hlist_entry(node, struct nr_neigh, neigh_node);
972 }
973
974 static void nr_neigh_stop(struct seq_file *seq, void *v)
975 {
976         spin_unlock_bh(&nr_neigh_list_lock);
977 }
978
979 static int nr_neigh_show(struct seq_file *seq, void *v)
980 {
981         char buf[11];
982         int i;
983
984         if (v == SEQ_START_TOKEN)
985                 seq_puts(seq, "addr  callsign  dev  qual lock count failed digipeaters\n");
986         else {
987                 struct nr_neigh *nr_neigh = v;
988
989                 seq_printf(seq, "%05d %-9s %-4s  %3d    %d   %3d    %3d",
990                         nr_neigh->number,
991                         ax2asc(buf, &nr_neigh->callsign),
992                         nr_neigh->dev ? nr_neigh->dev->name : "???",
993                         nr_neigh->quality,
994                         nr_neigh->locked,
995                         nr_neigh->count,
996                         nr_neigh->failed);
997
998                 if (nr_neigh->digipeat != NULL) {
999                         for (i = 0; i < nr_neigh->digipeat->ndigi; i++)
1000                                 seq_printf(seq, " %s",
1001                                            ax2asc(buf, &nr_neigh->digipeat->calls[i]));
1002                 }
1003
1004                 seq_puts(seq, "\n");
1005         }
1006         return 0;
1007 }
1008
1009 static struct seq_operations nr_neigh_seqops = {
1010         .start = nr_neigh_start,
1011         .next = nr_neigh_next,
1012         .stop = nr_neigh_stop,
1013         .show = nr_neigh_show,
1014 };
1015
1016 static int nr_neigh_info_open(struct inode *inode, struct file *file)
1017 {
1018         return seq_open(file, &nr_neigh_seqops);
1019 }
1020
1021 const struct file_operations nr_neigh_fops = {
1022         .owner = THIS_MODULE,
1023         .open = nr_neigh_info_open,
1024         .read = seq_read,
1025         .llseek = seq_lseek,
1026         .release = seq_release,
1027 };
1028
1029 #endif
1030
1031 /*
1032  *      Free all memory associated with the nodes and routes lists.
1033  */
1034 void __exit nr_rt_free(void)
1035 {
1036         struct nr_neigh *s = NULL;
1037         struct nr_node  *t = NULL;
1038         struct hlist_node *node, *nodet;
1039
1040         spin_lock_bh(&nr_neigh_list_lock);
1041         spin_lock_bh(&nr_node_list_lock);
1042         nr_node_for_each_safe(t, node, nodet, &nr_node_list) {
1043                 nr_node_lock(t);
1044                 nr_remove_node_locked(t);
1045                 nr_node_unlock(t);
1046         }
1047         nr_neigh_for_each_safe(s, node, nodet, &nr_neigh_list) {
1048                 while(s->count) {
1049                         s->count--;
1050                         nr_neigh_put(s);
1051                 }
1052                 nr_remove_neigh_locked(s);
1053         }
1054         spin_unlock_bh(&nr_node_list_lock);
1055         spin_unlock_bh(&nr_neigh_list_lock);
1056 }