xref: /openbmc/linux/net/netrom/nr_route.c (revision 1ccd4b7b)
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 <linux/slab.h>
21 #include <net/ax25.h>
22 #include <linux/inet.h>
23 #include <linux/netdevice.h>
24 #include <net/arp.h>
25 #include <linux/if_arp.h>
26 #include <linux/skbuff.h>
27 #include <net/sock.h>
28 #include <asm/uaccess.h>
29 #include <asm/system.h>
30 #include <linux/fcntl.h>
31 #include <linux/termios.h>	/* For TIOCINQ/OUTQ */
32 #include <linux/mm.h>
33 #include <linux/interrupt.h>
34 #include <linux/notifier.h>
35 #include <linux/netfilter.h>
36 #include <linux/init.h>
37 #include <linux/spinlock.h>
38 #include <net/netrom.h>
39 #include <linux/seq_file.h>
40 
41 static unsigned int nr_neigh_no = 1;
42 
43 static HLIST_HEAD(nr_node_list);
44 static DEFINE_SPINLOCK(nr_node_list_lock);
45 static HLIST_HEAD(nr_neigh_list);
46 static DEFINE_SPINLOCK(nr_neigh_list_lock);
47 
48 static struct nr_node *nr_node_get(ax25_address *callsign)
49 {
50 	struct nr_node *found = NULL;
51 	struct nr_node *nr_node;
52 	struct hlist_node *node;
53 
54 	spin_lock_bh(&nr_node_list_lock);
55 	nr_node_for_each(nr_node, node, &nr_node_list)
56 		if (ax25cmp(callsign, &nr_node->callsign) == 0) {
57 			nr_node_hold(nr_node);
58 			found = nr_node;
59 			break;
60 		}
61 	spin_unlock_bh(&nr_node_list_lock);
62 	return found;
63 }
64 
65 static struct nr_neigh *nr_neigh_get_dev(ax25_address *callsign,
66 					 struct net_device *dev)
67 {
68 	struct nr_neigh *found = NULL;
69 	struct nr_neigh *nr_neigh;
70 	struct hlist_node *node;
71 
72 	spin_lock_bh(&nr_neigh_list_lock);
73 	nr_neigh_for_each(nr_neigh, node, &nr_neigh_list)
74 		if (ax25cmp(callsign, &nr_neigh->callsign) == 0 &&
75 		    nr_neigh->dev == dev) {
76 			nr_neigh_hold(nr_neigh);
77 			found = nr_neigh;
78 			break;
79 		}
80 	spin_unlock_bh(&nr_neigh_list_lock);
81 	return found;
82 }
83 
84 static void nr_remove_neigh(struct nr_neigh *);
85 
86 /*
87  *	Add a new route to a node, and in the process add the node and the
88  *	neighbour if it is new.
89  */
90 static int __must_check nr_add_node(ax25_address *nr, const char *mnemonic,
91 	ax25_address *ax25, ax25_digi *ax25_digi, struct net_device *dev,
92 	int quality, int obs_count)
93 {
94 	struct nr_node  *nr_node;
95 	struct nr_neigh *nr_neigh;
96 	struct nr_route nr_route;
97 	int i, found;
98 	struct net_device *odev;
99 
100 	if ((odev=nr_dev_get(nr)) != NULL) {	/* Can't add routes to ourself */
101 		dev_put(odev);
102 		return -EINVAL;
103 	}
104 
105 	nr_node = nr_node_get(nr);
106 
107 	nr_neigh = nr_neigh_get_dev(ax25, dev);
108 
109 	/*
110 	 * The L2 link to a neighbour has failed in the past
111 	 * and now a frame comes from this neighbour. We assume
112 	 * it was a temporary trouble with the link and reset the
113 	 * routes now (and not wait for a node broadcast).
114 	 */
115 	if (nr_neigh != NULL && nr_neigh->failed != 0 && quality == 0) {
116 		struct nr_node *nr_nodet;
117 		struct hlist_node *node;
118 
119 		spin_lock_bh(&nr_node_list_lock);
120 		nr_node_for_each(nr_nodet, node, &nr_node_list) {
121 			nr_node_lock(nr_nodet);
122 			for (i = 0; i < nr_nodet->count; i++)
123 				if (nr_nodet->routes[i].neighbour == nr_neigh)
124 					if (i < nr_nodet->which)
125 						nr_nodet->which = i;
126 			nr_node_unlock(nr_nodet);
127 		}
128 		spin_unlock_bh(&nr_node_list_lock);
129 	}
130 
131 	if (nr_neigh != NULL)
132 		nr_neigh->failed = 0;
133 
134 	if (quality == 0 && nr_neigh != NULL && nr_node != NULL) {
135 		nr_neigh_put(nr_neigh);
136 		nr_node_put(nr_node);
137 		return 0;
138 	}
139 
140 	if (nr_neigh == NULL) {
141 		if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL) {
142 			if (nr_node)
143 				nr_node_put(nr_node);
144 			return -ENOMEM;
145 		}
146 
147 		nr_neigh->callsign = *ax25;
148 		nr_neigh->digipeat = NULL;
149 		nr_neigh->ax25     = NULL;
150 		nr_neigh->dev      = dev;
151 		nr_neigh->quality  = sysctl_netrom_default_path_quality;
152 		nr_neigh->locked   = 0;
153 		nr_neigh->count    = 0;
154 		nr_neigh->number   = nr_neigh_no++;
155 		nr_neigh->failed   = 0;
156 		atomic_set(&nr_neigh->refcount, 1);
157 
158 		if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
159 			nr_neigh->digipeat = kmemdup(ax25_digi,
160 						     sizeof(*ax25_digi),
161 						     GFP_KERNEL);
162 			if (nr_neigh->digipeat == NULL) {
163 				kfree(nr_neigh);
164 				if (nr_node)
165 					nr_node_put(nr_node);
166 				return -ENOMEM;
167 			}
168 		}
169 
170 		spin_lock_bh(&nr_neigh_list_lock);
171 		hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
172 		nr_neigh_hold(nr_neigh);
173 		spin_unlock_bh(&nr_neigh_list_lock);
174 	}
175 
176 	if (quality != 0 && ax25cmp(nr, ax25) == 0 && !nr_neigh->locked)
177 		nr_neigh->quality = quality;
178 
179 	if (nr_node == NULL) {
180 		if ((nr_node = kmalloc(sizeof(*nr_node), GFP_ATOMIC)) == NULL) {
181 			if (nr_neigh)
182 				nr_neigh_put(nr_neigh);
183 			return -ENOMEM;
184 		}
185 
186 		nr_node->callsign = *nr;
187 		strcpy(nr_node->mnemonic, mnemonic);
188 
189 		nr_node->which = 0;
190 		nr_node->count = 1;
191 		atomic_set(&nr_node->refcount, 1);
192 		spin_lock_init(&nr_node->node_lock);
193 
194 		nr_node->routes[0].quality   = quality;
195 		nr_node->routes[0].obs_count = obs_count;
196 		nr_node->routes[0].neighbour = nr_neigh;
197 
198 		nr_neigh_hold(nr_neigh);
199 		nr_neigh->count++;
200 
201 		spin_lock_bh(&nr_node_list_lock);
202 		hlist_add_head(&nr_node->node_node, &nr_node_list);
203 		/* refcount initialized at 1 */
204 		spin_unlock_bh(&nr_node_list_lock);
205 
206 		return 0;
207 	}
208 	nr_node_lock(nr_node);
209 
210 	if (quality != 0)
211 		strcpy(nr_node->mnemonic, mnemonic);
212 
213 	for (found = 0, i = 0; i < nr_node->count; i++) {
214 		if (nr_node->routes[i].neighbour == nr_neigh) {
215 			nr_node->routes[i].quality   = quality;
216 			nr_node->routes[i].obs_count = obs_count;
217 			found = 1;
218 			break;
219 		}
220 	}
221 
222 	if (!found) {
223 		/* We have space at the bottom, slot it in */
224 		if (nr_node->count < 3) {
225 			nr_node->routes[2] = nr_node->routes[1];
226 			nr_node->routes[1] = nr_node->routes[0];
227 
228 			nr_node->routes[0].quality   = quality;
229 			nr_node->routes[0].obs_count = obs_count;
230 			nr_node->routes[0].neighbour = nr_neigh;
231 
232 			nr_node->which++;
233 			nr_node->count++;
234 			nr_neigh_hold(nr_neigh);
235 			nr_neigh->count++;
236 		} else {
237 			/* It must be better than the worst */
238 			if (quality > nr_node->routes[2].quality) {
239 				nr_node->routes[2].neighbour->count--;
240 				nr_neigh_put(nr_node->routes[2].neighbour);
241 
242 				if (nr_node->routes[2].neighbour->count == 0 && !nr_node->routes[2].neighbour->locked)
243 					nr_remove_neigh(nr_node->routes[2].neighbour);
244 
245 				nr_node->routes[2].quality   = quality;
246 				nr_node->routes[2].obs_count = obs_count;
247 				nr_node->routes[2].neighbour = nr_neigh;
248 
249 				nr_neigh_hold(nr_neigh);
250 				nr_neigh->count++;
251 			}
252 		}
253 	}
254 
255 	/* Now re-sort the routes in quality order */
256 	switch (nr_node->count) {
257 	case 3:
258 		if (nr_node->routes[1].quality > nr_node->routes[0].quality) {
259 			switch (nr_node->which) {
260 			case 0:
261 				nr_node->which = 1;
262 				break;
263 			case 1:
264 				nr_node->which = 0;
265 				break;
266 			}
267 			nr_route           = nr_node->routes[0];
268 			nr_node->routes[0] = nr_node->routes[1];
269 			nr_node->routes[1] = nr_route;
270 		}
271 		if (nr_node->routes[2].quality > nr_node->routes[1].quality) {
272 			switch (nr_node->which) {
273 			case 1:  nr_node->which = 2;
274 				break;
275 
276 			case 2:  nr_node->which = 1;
277 				break;
278 
279 			default:
280 				break;
281 			}
282 			nr_route           = nr_node->routes[1];
283 			nr_node->routes[1] = nr_node->routes[2];
284 			nr_node->routes[2] = nr_route;
285 		}
286 	case 2:
287 		if (nr_node->routes[1].quality > nr_node->routes[0].quality) {
288 			switch (nr_node->which) {
289 			case 0:  nr_node->which = 1;
290 				break;
291 
292 			case 1:  nr_node->which = 0;
293 				break;
294 
295 			default: break;
296 			}
297 			nr_route           = nr_node->routes[0];
298 			nr_node->routes[0] = nr_node->routes[1];
299 			nr_node->routes[1] = nr_route;
300 			}
301 	case 1:
302 		break;
303 	}
304 
305 	for (i = 0; i < nr_node->count; i++) {
306 		if (nr_node->routes[i].neighbour == nr_neigh) {
307 			if (i < nr_node->which)
308 				nr_node->which = i;
309 			break;
310 		}
311 	}
312 
313 	nr_neigh_put(nr_neigh);
314 	nr_node_unlock(nr_node);
315 	nr_node_put(nr_node);
316 	return 0;
317 }
318 
319 static inline void __nr_remove_node(struct nr_node *nr_node)
320 {
321 	hlist_del_init(&nr_node->node_node);
322 	nr_node_put(nr_node);
323 }
324 
325 #define nr_remove_node_locked(__node) \
326 	__nr_remove_node(__node)
327 
328 static void nr_remove_node(struct nr_node *nr_node)
329 {
330 	spin_lock_bh(&nr_node_list_lock);
331 	__nr_remove_node(nr_node);
332 	spin_unlock_bh(&nr_node_list_lock);
333 }
334 
335 static inline void __nr_remove_neigh(struct nr_neigh *nr_neigh)
336 {
337 	hlist_del_init(&nr_neigh->neigh_node);
338 	nr_neigh_put(nr_neigh);
339 }
340 
341 #define nr_remove_neigh_locked(__neigh) \
342 	__nr_remove_neigh(__neigh)
343 
344 static void nr_remove_neigh(struct nr_neigh *nr_neigh)
345 {
346 	spin_lock_bh(&nr_neigh_list_lock);
347 	__nr_remove_neigh(nr_neigh);
348 	spin_unlock_bh(&nr_neigh_list_lock);
349 }
350 
351 /*
352  *	"Delete" a node. Strictly speaking remove a route to a node. The node
353  *	is only deleted if no routes are left to it.
354  */
355 static int nr_del_node(ax25_address *callsign, ax25_address *neighbour, struct net_device *dev)
356 {
357 	struct nr_node  *nr_node;
358 	struct nr_neigh *nr_neigh;
359 	int i;
360 
361 	nr_node = nr_node_get(callsign);
362 
363 	if (nr_node == NULL)
364 		return -EINVAL;
365 
366 	nr_neigh = nr_neigh_get_dev(neighbour, dev);
367 
368 	if (nr_neigh == NULL) {
369 		nr_node_put(nr_node);
370 		return -EINVAL;
371 	}
372 
373 	nr_node_lock(nr_node);
374 	for (i = 0; i < nr_node->count; i++) {
375 		if (nr_node->routes[i].neighbour == nr_neigh) {
376 			nr_neigh->count--;
377 			nr_neigh_put(nr_neigh);
378 
379 			if (nr_neigh->count == 0 && !nr_neigh->locked)
380 				nr_remove_neigh(nr_neigh);
381 			nr_neigh_put(nr_neigh);
382 
383 			nr_node->count--;
384 
385 			if (nr_node->count == 0) {
386 				nr_remove_node(nr_node);
387 			} else {
388 				switch (i) {
389 				case 0:
390 					nr_node->routes[0] = nr_node->routes[1];
391 				case 1:
392 					nr_node->routes[1] = nr_node->routes[2];
393 				case 2:
394 					break;
395 				}
396 				nr_node_put(nr_node);
397 			}
398 			nr_node_unlock(nr_node);
399 
400 			return 0;
401 		}
402 	}
403 	nr_neigh_put(nr_neigh);
404 	nr_node_unlock(nr_node);
405 	nr_node_put(nr_node);
406 
407 	return -EINVAL;
408 }
409 
410 /*
411  *	Lock a neighbour with a quality.
412  */
413 static int __must_check nr_add_neigh(ax25_address *callsign,
414 	ax25_digi *ax25_digi, struct net_device *dev, unsigned int quality)
415 {
416 	struct nr_neigh *nr_neigh;
417 
418 	nr_neigh = nr_neigh_get_dev(callsign, dev);
419 	if (nr_neigh) {
420 		nr_neigh->quality = quality;
421 		nr_neigh->locked  = 1;
422 		nr_neigh_put(nr_neigh);
423 		return 0;
424 	}
425 
426 	if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL)
427 		return -ENOMEM;
428 
429 	nr_neigh->callsign = *callsign;
430 	nr_neigh->digipeat = NULL;
431 	nr_neigh->ax25     = NULL;
432 	nr_neigh->dev      = dev;
433 	nr_neigh->quality  = quality;
434 	nr_neigh->locked   = 1;
435 	nr_neigh->count    = 0;
436 	nr_neigh->number   = nr_neigh_no++;
437 	nr_neigh->failed   = 0;
438 	atomic_set(&nr_neigh->refcount, 1);
439 
440 	if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
441 		nr_neigh->digipeat = kmemdup(ax25_digi, sizeof(*ax25_digi),
442 					     GFP_KERNEL);
443 		if (nr_neigh->digipeat == NULL) {
444 			kfree(nr_neigh);
445 			return -ENOMEM;
446 		}
447 	}
448 
449 	spin_lock_bh(&nr_neigh_list_lock);
450 	hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
451 	/* refcount is initialized at 1 */
452 	spin_unlock_bh(&nr_neigh_list_lock);
453 
454 	return 0;
455 }
456 
457 /*
458  *	"Delete" a neighbour. The neighbour is only removed if the number
459  *	of nodes that may use it is zero.
460  */
461 static int nr_del_neigh(ax25_address *callsign, struct net_device *dev, unsigned int quality)
462 {
463 	struct nr_neigh *nr_neigh;
464 
465 	nr_neigh = nr_neigh_get_dev(callsign, dev);
466 
467 	if (nr_neigh == NULL) return -EINVAL;
468 
469 	nr_neigh->quality = quality;
470 	nr_neigh->locked  = 0;
471 
472 	if (nr_neigh->count == 0)
473 		nr_remove_neigh(nr_neigh);
474 	nr_neigh_put(nr_neigh);
475 
476 	return 0;
477 }
478 
479 /*
480  *	Decrement the obsolescence count by one. If a route is reduced to a
481  *	count of zero, remove it. Also remove any unlocked neighbours with
482  *	zero nodes routing via it.
483  */
484 static int nr_dec_obs(void)
485 {
486 	struct nr_neigh *nr_neigh;
487 	struct nr_node  *s;
488 	struct hlist_node *node, *nodet;
489 	int i;
490 
491 	spin_lock_bh(&nr_node_list_lock);
492 	nr_node_for_each_safe(s, node, nodet, &nr_node_list) {
493 		nr_node_lock(s);
494 		for (i = 0; i < s->count; i++) {
495 			switch (s->routes[i].obs_count) {
496 			case 0:		/* A locked entry */
497 				break;
498 
499 			case 1:		/* From 1 -> 0 */
500 				nr_neigh = s->routes[i].neighbour;
501 
502 				nr_neigh->count--;
503 				nr_neigh_put(nr_neigh);
504 
505 				if (nr_neigh->count == 0 && !nr_neigh->locked)
506 					nr_remove_neigh(nr_neigh);
507 
508 				s->count--;
509 
510 				switch (i) {
511 				case 0:
512 					s->routes[0] = s->routes[1];
513 					/* Fallthrough */
514 				case 1:
515 					s->routes[1] = s->routes[2];
516 				case 2:
517 					break;
518 				}
519 				break;
520 
521 			default:
522 				s->routes[i].obs_count--;
523 				break;
524 
525 			}
526 		}
527 
528 		if (s->count <= 0)
529 			nr_remove_node_locked(s);
530 		nr_node_unlock(s);
531 	}
532 	spin_unlock_bh(&nr_node_list_lock);
533 
534 	return 0;
535 }
536 
537 /*
538  *	A device has been removed. Remove its routes and neighbours.
539  */
540 void nr_rt_device_down(struct net_device *dev)
541 {
542 	struct nr_neigh *s;
543 	struct hlist_node *node, *nodet, *node2, *node2t;
544 	struct nr_node  *t;
545 	int i;
546 
547 	spin_lock_bh(&nr_neigh_list_lock);
548 	nr_neigh_for_each_safe(s, node, nodet, &nr_neigh_list) {
549 		if (s->dev == dev) {
550 			spin_lock_bh(&nr_node_list_lock);
551 			nr_node_for_each_safe(t, node2, node2t, &nr_node_list) {
552 				nr_node_lock(t);
553 				for (i = 0; i < t->count; i++) {
554 					if (t->routes[i].neighbour == s) {
555 						t->count--;
556 
557 						switch (i) {
558 						case 0:
559 							t->routes[0] = t->routes[1];
560 						case 1:
561 							t->routes[1] = t->routes[2];
562 						case 2:
563 							break;
564 						}
565 					}
566 				}
567 
568 				if (t->count <= 0)
569 					nr_remove_node_locked(t);
570 				nr_node_unlock(t);
571 			}
572 			spin_unlock_bh(&nr_node_list_lock);
573 
574 			nr_remove_neigh_locked(s);
575 		}
576 	}
577 	spin_unlock_bh(&nr_neigh_list_lock);
578 }
579 
580 /*
581  *	Check that the device given is a valid AX.25 interface that is "up".
582  *	Or a valid ethernet interface with an AX.25 callsign binding.
583  */
584 static struct net_device *nr_ax25_dev_get(char *devname)
585 {
586 	struct net_device *dev;
587 
588 	if ((dev = dev_get_by_name(&init_net, devname)) == NULL)
589 		return NULL;
590 
591 	if ((dev->flags & IFF_UP) && dev->type == ARPHRD_AX25)
592 		return dev;
593 
594 	dev_put(dev);
595 	return NULL;
596 }
597 
598 /*
599  *	Find the first active NET/ROM device, usually "nr0".
600  */
601 struct net_device *nr_dev_first(void)
602 {
603 	struct net_device *dev, *first = NULL;
604 
605 	rcu_read_lock();
606 	for_each_netdev_rcu(&init_net, dev) {
607 		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM)
608 			if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
609 				first = dev;
610 	}
611 	if (first)
612 		dev_hold(first);
613 	rcu_read_unlock();
614 
615 	return first;
616 }
617 
618 /*
619  *	Find the NET/ROM device for the given callsign.
620  */
621 struct net_device *nr_dev_get(ax25_address *addr)
622 {
623 	struct net_device *dev;
624 
625 	rcu_read_lock();
626 	for_each_netdev_rcu(&init_net, dev) {
627 		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM &&
628 		    ax25cmp(addr, (ax25_address *)dev->dev_addr) == 0) {
629 			dev_hold(dev);
630 			goto out;
631 		}
632 	}
633 	dev = NULL;
634 out:
635 	rcu_read_unlock();
636 	return dev;
637 }
638 
639 static ax25_digi *nr_call_to_digi(ax25_digi *digi, int ndigis,
640 	ax25_address *digipeaters)
641 {
642 	int i;
643 
644 	if (ndigis == 0)
645 		return NULL;
646 
647 	for (i = 0; i < ndigis; i++) {
648 		digi->calls[i]    = digipeaters[i];
649 		digi->repeated[i] = 0;
650 	}
651 
652 	digi->ndigi      = ndigis;
653 	digi->lastrepeat = -1;
654 
655 	return digi;
656 }
657 
658 /*
659  *	Handle the ioctls that control the routing functions.
660  */
661 int nr_rt_ioctl(unsigned int cmd, void __user *arg)
662 {
663 	struct nr_route_struct nr_route;
664 	struct net_device *dev;
665 	ax25_digi digi;
666 	int ret;
667 
668 	switch (cmd) {
669 	case SIOCADDRT:
670 		if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
671 			return -EFAULT;
672 		if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
673 			return -EINVAL;
674 		if (nr_route.ndigis < 0 || nr_route.ndigis > AX25_MAX_DIGIS) {
675 			dev_put(dev);
676 			return -EINVAL;
677 		}
678 		switch (nr_route.type) {
679 		case NETROM_NODE:
680 			ret = nr_add_node(&nr_route.callsign,
681 				nr_route.mnemonic,
682 				&nr_route.neighbour,
683 				nr_call_to_digi(&digi, nr_route.ndigis,
684 						nr_route.digipeaters),
685 				dev, nr_route.quality,
686 				nr_route.obs_count);
687 			break;
688 		case NETROM_NEIGH:
689 			ret = nr_add_neigh(&nr_route.callsign,
690 				nr_call_to_digi(&digi, nr_route.ndigis,
691 						nr_route.digipeaters),
692 				dev, nr_route.quality);
693 			break;
694 		default:
695 			ret = -EINVAL;
696 		}
697 		dev_put(dev);
698 		return ret;
699 
700 	case SIOCDELRT:
701 		if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
702 			return -EFAULT;
703 		if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
704 			return -EINVAL;
705 		switch (nr_route.type) {
706 		case NETROM_NODE:
707 			ret = nr_del_node(&nr_route.callsign,
708 				&nr_route.neighbour, dev);
709 			break;
710 		case NETROM_NEIGH:
711 			ret = nr_del_neigh(&nr_route.callsign,
712 				dev, nr_route.quality);
713 			break;
714 		default:
715 			ret = -EINVAL;
716 		}
717 		dev_put(dev);
718 		return ret;
719 
720 	case SIOCNRDECOBS:
721 		return nr_dec_obs();
722 
723 	default:
724 		return -EINVAL;
725 	}
726 
727 	return 0;
728 }
729 
730 /*
731  * 	A level 2 link has timed out, therefore it appears to be a poor link,
732  *	then don't use that neighbour until it is reset.
733  */
734 void nr_link_failed(ax25_cb *ax25, int reason)
735 {
736 	struct nr_neigh *s, *nr_neigh = NULL;
737 	struct hlist_node *node;
738 	struct nr_node  *nr_node = NULL;
739 
740 	spin_lock_bh(&nr_neigh_list_lock);
741 	nr_neigh_for_each(s, node, &nr_neigh_list) {
742 		if (s->ax25 == ax25) {
743 			nr_neigh_hold(s);
744 			nr_neigh = s;
745 			break;
746 		}
747 	}
748 	spin_unlock_bh(&nr_neigh_list_lock);
749 
750 	if (nr_neigh == NULL)
751 		return;
752 
753 	nr_neigh->ax25 = NULL;
754 	ax25_cb_put(ax25);
755 
756 	if (++nr_neigh->failed < sysctl_netrom_link_fails_count) {
757 		nr_neigh_put(nr_neigh);
758 		return;
759 	}
760 	spin_lock_bh(&nr_node_list_lock);
761 	nr_node_for_each(nr_node, node, &nr_node_list) {
762 		nr_node_lock(nr_node);
763 		if (nr_node->which < nr_node->count &&
764 		    nr_node->routes[nr_node->which].neighbour == nr_neigh)
765 			nr_node->which++;
766 		nr_node_unlock(nr_node);
767 	}
768 	spin_unlock_bh(&nr_node_list_lock);
769 	nr_neigh_put(nr_neigh);
770 }
771 
772 /*
773  *	Route a frame to an appropriate AX.25 connection. A NULL ax25_cb
774  *	indicates an internally generated frame.
775  */
776 int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
777 {
778 	ax25_address *nr_src, *nr_dest;
779 	struct nr_neigh *nr_neigh;
780 	struct nr_node  *nr_node;
781 	struct net_device *dev;
782 	unsigned char *dptr;
783 	ax25_cb *ax25s;
784 	int ret;
785 	struct sk_buff *skbn;
786 
787 
788 	nr_src  = (ax25_address *)(skb->data + 0);
789 	nr_dest = (ax25_address *)(skb->data + 7);
790 
791 	if (ax25 != NULL) {
792 		ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
793 				  ax25->ax25_dev->dev, 0,
794 				  sysctl_netrom_obsolescence_count_initialiser);
795 		if (ret)
796 			return ret;
797 	}
798 
799 	if ((dev = nr_dev_get(nr_dest)) != NULL) {	/* Its for me */
800 		if (ax25 == NULL)			/* Its from me */
801 			ret = nr_loopback_queue(skb);
802 		else
803 			ret = nr_rx_frame(skb, dev);
804 		dev_put(dev);
805 		return ret;
806 	}
807 
808 	if (!sysctl_netrom_routing_control && ax25 != NULL)
809 		return 0;
810 
811 	/* Its Time-To-Live has expired */
812 	if (skb->data[14] == 1) {
813 		return 0;
814 	}
815 
816 	nr_node = nr_node_get(nr_dest);
817 	if (nr_node == NULL)
818 		return 0;
819 	nr_node_lock(nr_node);
820 
821 	if (nr_node->which >= nr_node->count) {
822 		nr_node_unlock(nr_node);
823 		nr_node_put(nr_node);
824 		return 0;
825 	}
826 
827 	nr_neigh = nr_node->routes[nr_node->which].neighbour;
828 
829 	if ((dev = nr_dev_first()) == NULL) {
830 		nr_node_unlock(nr_node);
831 		nr_node_put(nr_node);
832 		return 0;
833 	}
834 
835 	/* We are going to change the netrom headers so we should get our
836 	   own skb, we also did not know until now how much header space
837 	   we had to reserve... - RXQ */
838 	if ((skbn=skb_copy_expand(skb, dev->hard_header_len, 0, GFP_ATOMIC)) == NULL) {
839 		nr_node_unlock(nr_node);
840 		nr_node_put(nr_node);
841 		dev_put(dev);
842 		return 0;
843 	}
844 	kfree_skb(skb);
845 	skb=skbn;
846 	skb->data[14]--;
847 
848 	dptr  = skb_push(skb, 1);
849 	*dptr = AX25_P_NETROM;
850 
851 	ax25s = nr_neigh->ax25;
852 	nr_neigh->ax25 = ax25_send_frame(skb, 256,
853 					 (ax25_address *)dev->dev_addr,
854 					 &nr_neigh->callsign,
855 					 nr_neigh->digipeat, nr_neigh->dev);
856 	if (ax25s)
857 		ax25_cb_put(ax25s);
858 
859 	dev_put(dev);
860 	ret = (nr_neigh->ax25 != NULL);
861 	nr_node_unlock(nr_node);
862 	nr_node_put(nr_node);
863 
864 	return ret;
865 }
866 
867 #ifdef CONFIG_PROC_FS
868 
869 static void *nr_node_start(struct seq_file *seq, loff_t *pos)
870 {
871 	spin_lock_bh(&nr_node_list_lock);
872 	return seq_hlist_start_head(&nr_node_list, *pos);
873 }
874 
875 static void *nr_node_next(struct seq_file *seq, void *v, loff_t *pos)
876 {
877 	return seq_hlist_next(v, &nr_node_list, pos);
878 }
879 
880 static void nr_node_stop(struct seq_file *seq, void *v)
881 {
882 	spin_unlock_bh(&nr_node_list_lock);
883 }
884 
885 static int nr_node_show(struct seq_file *seq, void *v)
886 {
887 	char buf[11];
888 	int i;
889 
890 	if (v == SEQ_START_TOKEN)
891 		seq_puts(seq,
892 			 "callsign  mnemonic w n qual obs neigh qual obs neigh qual obs neigh\n");
893 	else {
894 		struct nr_node *nr_node = hlist_entry(v, struct nr_node,
895 						      node_node);
896 
897 		nr_node_lock(nr_node);
898 		seq_printf(seq, "%-9s %-7s  %d %d",
899 			ax2asc(buf, &nr_node->callsign),
900 			(nr_node->mnemonic[0] == '\0') ? "*" : nr_node->mnemonic,
901 			nr_node->which + 1,
902 			nr_node->count);
903 
904 		for (i = 0; i < nr_node->count; i++) {
905 			seq_printf(seq, "  %3d   %d %05d",
906 				nr_node->routes[i].quality,
907 				nr_node->routes[i].obs_count,
908 				nr_node->routes[i].neighbour->number);
909 		}
910 		nr_node_unlock(nr_node);
911 
912 		seq_puts(seq, "\n");
913 	}
914 	return 0;
915 }
916 
917 static const struct seq_operations nr_node_seqops = {
918 	.start = nr_node_start,
919 	.next = nr_node_next,
920 	.stop = nr_node_stop,
921 	.show = nr_node_show,
922 };
923 
924 static int nr_node_info_open(struct inode *inode, struct file *file)
925 {
926 	return seq_open(file, &nr_node_seqops);
927 }
928 
929 const struct file_operations nr_nodes_fops = {
930 	.owner = THIS_MODULE,
931 	.open = nr_node_info_open,
932 	.read = seq_read,
933 	.llseek = seq_lseek,
934 	.release = seq_release,
935 };
936 
937 static void *nr_neigh_start(struct seq_file *seq, loff_t *pos)
938 {
939 	spin_lock_bh(&nr_neigh_list_lock);
940 	return seq_hlist_start_head(&nr_neigh_list, *pos);
941 }
942 
943 static void *nr_neigh_next(struct seq_file *seq, void *v, loff_t *pos)
944 {
945 	return seq_hlist_next(v, &nr_neigh_list, pos);
946 }
947 
948 static void nr_neigh_stop(struct seq_file *seq, void *v)
949 {
950 	spin_unlock_bh(&nr_neigh_list_lock);
951 }
952 
953 static int nr_neigh_show(struct seq_file *seq, void *v)
954 {
955 	char buf[11];
956 	int i;
957 
958 	if (v == SEQ_START_TOKEN)
959 		seq_puts(seq, "addr  callsign  dev  qual lock count failed digipeaters\n");
960 	else {
961 		struct nr_neigh *nr_neigh;
962 
963 		nr_neigh = hlist_entry(v, struct nr_neigh, neigh_node);
964 		seq_printf(seq, "%05d %-9s %-4s  %3d    %d   %3d    %3d",
965 			nr_neigh->number,
966 			ax2asc(buf, &nr_neigh->callsign),
967 			nr_neigh->dev ? nr_neigh->dev->name : "???",
968 			nr_neigh->quality,
969 			nr_neigh->locked,
970 			nr_neigh->count,
971 			nr_neigh->failed);
972 
973 		if (nr_neigh->digipeat != NULL) {
974 			for (i = 0; i < nr_neigh->digipeat->ndigi; i++)
975 				seq_printf(seq, " %s",
976 					   ax2asc(buf, &nr_neigh->digipeat->calls[i]));
977 		}
978 
979 		seq_puts(seq, "\n");
980 	}
981 	return 0;
982 }
983 
984 static const struct seq_operations nr_neigh_seqops = {
985 	.start = nr_neigh_start,
986 	.next = nr_neigh_next,
987 	.stop = nr_neigh_stop,
988 	.show = nr_neigh_show,
989 };
990 
991 static int nr_neigh_info_open(struct inode *inode, struct file *file)
992 {
993 	return seq_open(file, &nr_neigh_seqops);
994 }
995 
996 const struct file_operations nr_neigh_fops = {
997 	.owner = THIS_MODULE,
998 	.open = nr_neigh_info_open,
999 	.read = seq_read,
1000 	.llseek = seq_lseek,
1001 	.release = seq_release,
1002 };
1003 
1004 #endif
1005 
1006 /*
1007  *	Free all memory associated with the nodes and routes lists.
1008  */
1009 void __exit nr_rt_free(void)
1010 {
1011 	struct nr_neigh *s = NULL;
1012 	struct nr_node  *t = NULL;
1013 	struct hlist_node *node, *nodet;
1014 
1015 	spin_lock_bh(&nr_neigh_list_lock);
1016 	spin_lock_bh(&nr_node_list_lock);
1017 	nr_node_for_each_safe(t, node, nodet, &nr_node_list) {
1018 		nr_node_lock(t);
1019 		nr_remove_node_locked(t);
1020 		nr_node_unlock(t);
1021 	}
1022 	nr_neigh_for_each_safe(s, node, nodet, &nr_neigh_list) {
1023 		while(s->count) {
1024 			s->count--;
1025 			nr_neigh_put(s);
1026 		}
1027 		nr_remove_neigh_locked(s);
1028 	}
1029 	spin_unlock_bh(&nr_node_list_lock);
1030 	spin_unlock_bh(&nr_neigh_list_lock);
1031 }
1032