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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 <linux/uaccess.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/init.h>
35#include <linux/spinlock.h>
36#include <net/netrom.h>
37#include <linux/seq_file.h>
38#include <linux/export.h>
39
40static unsigned int nr_neigh_no = 1;
41
42static HLIST_HEAD(nr_node_list);
43static DEFINE_SPINLOCK(nr_node_list_lock);
44static HLIST_HEAD(nr_neigh_list);
45static DEFINE_SPINLOCK(nr_neigh_list_lock);
46
47static struct nr_node *nr_node_get(ax25_address *callsign)
48{
49 struct nr_node *found = NULL;
50 struct nr_node *nr_node;
51
52 spin_lock_bh(&nr_node_list_lock);
53 nr_node_for_each(nr_node, &nr_node_list)
54 if (ax25cmp(callsign, &nr_node->callsign) == 0) {
55 nr_node_hold(nr_node);
56 found = nr_node;
57 break;
58 }
59 spin_unlock_bh(&nr_node_list_lock);
60 return found;
61}
62
63static struct nr_neigh *nr_neigh_get_dev(ax25_address *callsign,
64 struct net_device *dev)
65{
66 struct nr_neigh *found = NULL;
67 struct nr_neigh *nr_neigh;
68
69 spin_lock_bh(&nr_neigh_list_lock);
70 nr_neigh_for_each(nr_neigh, &nr_neigh_list)
71 if (ax25cmp(callsign, &nr_neigh->callsign) == 0 &&
72 nr_neigh->dev == dev) {
73 nr_neigh_hold(nr_neigh);
74 found = nr_neigh;
75 break;
76 }
77 spin_unlock_bh(&nr_neigh_list_lock);
78 return found;
79}
80
81static void nr_remove_neigh(struct nr_neigh *);
82
83/*
84 * Add a new route to a node, and in the process add the node and the
85 * neighbour if it is new.
86 */
87static int __must_check nr_add_node(ax25_address *nr, const char *mnemonic,
88 ax25_address *ax25, ax25_digi *ax25_digi, struct net_device *dev,
89 int quality, int obs_count)
90{
91 struct nr_node *nr_node;
92 struct nr_neigh *nr_neigh;
93 struct nr_route nr_route;
94 int i, found;
95 struct net_device *odev;
96
97 if ((odev=nr_dev_get(nr)) != NULL) { /* Can't add routes to ourself */
98 dev_put(odev);
99 return -EINVAL;
100 }
101
102 nr_node = nr_node_get(nr);
103
104 nr_neigh = nr_neigh_get_dev(ax25, dev);
105
106 /*
107 * The L2 link to a neighbour has failed in the past
108 * and now a frame comes from this neighbour. We assume
109 * it was a temporary trouble with the link and reset the
110 * routes now (and not wait for a node broadcast).
111 */
112 if (nr_neigh != NULL && nr_neigh->failed != 0 && quality == 0) {
113 struct nr_node *nr_nodet;
114
115 spin_lock_bh(&nr_node_list_lock);
116 nr_node_for_each(nr_nodet, &nr_node_list) {
117 nr_node_lock(nr_nodet);
118 for (i = 0; i < nr_nodet->count; i++)
119 if (nr_nodet->routes[i].neighbour == nr_neigh)
120 if (i < nr_nodet->which)
121 nr_nodet->which = i;
122 nr_node_unlock(nr_nodet);
123 }
124 spin_unlock_bh(&nr_node_list_lock);
125 }
126
127 if (nr_neigh != NULL)
128 nr_neigh->failed = 0;
129
130 if (quality == 0 && nr_neigh != NULL && nr_node != NULL) {
131 nr_neigh_put(nr_neigh);
132 nr_node_put(nr_node);
133 return 0;
134 }
135
136 if (nr_neigh == NULL) {
137 if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL) {
138 if (nr_node)
139 nr_node_put(nr_node);
140 return -ENOMEM;
141 }
142
143 nr_neigh->callsign = *ax25;
144 nr_neigh->digipeat = NULL;
145 nr_neigh->ax25 = NULL;
146 nr_neigh->dev = dev;
147 nr_neigh->quality = sysctl_netrom_default_path_quality;
148 nr_neigh->locked = 0;
149 nr_neigh->count = 0;
150 nr_neigh->number = nr_neigh_no++;
151 nr_neigh->failed = 0;
152 atomic_set(&nr_neigh->refcount, 1);
153
154 if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
155 nr_neigh->digipeat = kmemdup(ax25_digi,
156 sizeof(*ax25_digi),
157 GFP_KERNEL);
158 if (nr_neigh->digipeat == NULL) {
159 kfree(nr_neigh);
160 if (nr_node)
161 nr_node_put(nr_node);
162 return -ENOMEM;
163 }
164 }
165
166 spin_lock_bh(&nr_neigh_list_lock);
167 hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
168 nr_neigh_hold(nr_neigh);
169 spin_unlock_bh(&nr_neigh_list_lock);
170 }
171
172 if (quality != 0 && ax25cmp(nr, ax25) == 0 && !nr_neigh->locked)
173 nr_neigh->quality = quality;
174
175 if (nr_node == NULL) {
176 if ((nr_node = kmalloc(sizeof(*nr_node), GFP_ATOMIC)) == NULL) {
177 if (nr_neigh)
178 nr_neigh_put(nr_neigh);
179 return -ENOMEM;
180 }
181
182 nr_node->callsign = *nr;
183 strcpy(nr_node->mnemonic, mnemonic);
184
185 nr_node->which = 0;
186 nr_node->count = 1;
187 atomic_set(&nr_node->refcount, 1);
188 spin_lock_init(&nr_node->node_lock);
189
190 nr_node->routes[0].quality = quality;
191 nr_node->routes[0].obs_count = obs_count;
192 nr_node->routes[0].neighbour = nr_neigh;
193
194 nr_neigh_hold(nr_neigh);
195 nr_neigh->count++;
196
197 spin_lock_bh(&nr_node_list_lock);
198 hlist_add_head(&nr_node->node_node, &nr_node_list);
199 /* refcount initialized at 1 */
200 spin_unlock_bh(&nr_node_list_lock);
201
202 return 0;
203 }
204 nr_node_lock(nr_node);
205
206 if (quality != 0)
207 strcpy(nr_node->mnemonic, mnemonic);
208
209 for (found = 0, i = 0; i < nr_node->count; i++) {
210 if (nr_node->routes[i].neighbour == nr_neigh) {
211 nr_node->routes[i].quality = quality;
212 nr_node->routes[i].obs_count = obs_count;
213 found = 1;
214 break;
215 }
216 }
217
218 if (!found) {
219 /* We have space at the bottom, slot it in */
220 if (nr_node->count < 3) {
221 nr_node->routes[2] = nr_node->routes[1];
222 nr_node->routes[1] = nr_node->routes[0];
223
224 nr_node->routes[0].quality = quality;
225 nr_node->routes[0].obs_count = obs_count;
226 nr_node->routes[0].neighbour = nr_neigh;
227
228 nr_node->which++;
229 nr_node->count++;
230 nr_neigh_hold(nr_neigh);
231 nr_neigh->count++;
232 } else {
233 /* It must be better than the worst */
234 if (quality > nr_node->routes[2].quality) {
235 nr_node->routes[2].neighbour->count--;
236 nr_neigh_put(nr_node->routes[2].neighbour);
237
238 if (nr_node->routes[2].neighbour->count == 0 && !nr_node->routes[2].neighbour->locked)
239 nr_remove_neigh(nr_node->routes[2].neighbour);
240
241 nr_node->routes[2].quality = quality;
242 nr_node->routes[2].obs_count = obs_count;
243 nr_node->routes[2].neighbour = nr_neigh;
244
245 nr_neigh_hold(nr_neigh);
246 nr_neigh->count++;
247 }
248 }
249 }
250
251 /* Now re-sort the routes in quality order */
252 switch (nr_node->count) {
253 case 3:
254 if (nr_node->routes[1].quality > nr_node->routes[0].quality) {
255 switch (nr_node->which) {
256 case 0:
257 nr_node->which = 1;
258 break;
259 case 1:
260 nr_node->which = 0;
261 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
315static 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
324static 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
331static 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
340static 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 */
351static 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 */
409static 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 */
457static 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 */
480static int nr_dec_obs(void)
481{
482 struct nr_neigh *nr_neigh;
483 struct nr_node *s;
484 struct hlist_node *nodet;
485 int i;
486
487 spin_lock_bh(&nr_node_list_lock);
488 nr_node_for_each_safe(s, 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 /* Fallthrough */
510 case 1:
511 s->routes[1] = s->routes[2];
512 case 2:
513 break;
514 }
515 break;
516
517 default:
518 s->routes[i].obs_count--;
519 break;
520
521 }
522 }
523
524 if (s->count <= 0)
525 nr_remove_node_locked(s);
526 nr_node_unlock(s);
527 }
528 spin_unlock_bh(&nr_node_list_lock);
529
530 return 0;
531}
532
533/*
534 * A device has been removed. Remove its routes and neighbours.
535 */
536void nr_rt_device_down(struct net_device *dev)
537{
538 struct nr_neigh *s;
539 struct hlist_node *nodet, *node2t;
540 struct nr_node *t;
541 int i;
542
543 spin_lock_bh(&nr_neigh_list_lock);
544 nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
545 if (s->dev == dev) {
546 spin_lock_bh(&nr_node_list_lock);
547 nr_node_for_each_safe(t, node2t, &nr_node_list) {
548 nr_node_lock(t);
549 for (i = 0; i < t->count; i++) {
550 if (t->routes[i].neighbour == s) {
551 t->count--;
552
553 switch (i) {
554 case 0:
555 t->routes[0] = t->routes[1];
556 case 1:
557 t->routes[1] = t->routes[2];
558 case 2:
559 break;
560 }
561 }
562 }
563
564 if (t->count <= 0)
565 nr_remove_node_locked(t);
566 nr_node_unlock(t);
567 }
568 spin_unlock_bh(&nr_node_list_lock);
569
570 nr_remove_neigh_locked(s);
571 }
572 }
573 spin_unlock_bh(&nr_neigh_list_lock);
574}
575
576/*
577 * Check that the device given is a valid AX.25 interface that is "up".
578 * Or a valid ethernet interface with an AX.25 callsign binding.
579 */
580static struct net_device *nr_ax25_dev_get(char *devname)
581{
582 struct net_device *dev;
583
584 if ((dev = dev_get_by_name(&init_net, devname)) == NULL)
585 return NULL;
586
587 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_AX25)
588 return dev;
589
590 dev_put(dev);
591 return NULL;
592}
593
594/*
595 * Find the first active NET/ROM device, usually "nr0".
596 */
597struct net_device *nr_dev_first(void)
598{
599 struct net_device *dev, *first = NULL;
600
601 rcu_read_lock();
602 for_each_netdev_rcu(&init_net, dev) {
603 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM)
604 if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
605 first = dev;
606 }
607 if (first)
608 dev_hold(first);
609 rcu_read_unlock();
610
611 return first;
612}
613
614/*
615 * Find the NET/ROM device for the given callsign.
616 */
617struct net_device *nr_dev_get(ax25_address *addr)
618{
619 struct net_device *dev;
620
621 rcu_read_lock();
622 for_each_netdev_rcu(&init_net, dev) {
623 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM &&
624 ax25cmp(addr, (ax25_address *)dev->dev_addr) == 0) {
625 dev_hold(dev);
626 goto out;
627 }
628 }
629 dev = NULL;
630out:
631 rcu_read_unlock();
632 return dev;
633}
634
635static ax25_digi *nr_call_to_digi(ax25_digi *digi, int ndigis,
636 ax25_address *digipeaters)
637{
638 int i;
639
640 if (ndigis == 0)
641 return NULL;
642
643 for (i = 0; i < ndigis; i++) {
644 digi->calls[i] = digipeaters[i];
645 digi->repeated[i] = 0;
646 }
647
648 digi->ndigi = ndigis;
649 digi->lastrepeat = -1;
650
651 return digi;
652}
653
654/*
655 * Handle the ioctls that control the routing functions.
656 */
657int nr_rt_ioctl(unsigned int cmd, void __user *arg)
658{
659 struct nr_route_struct nr_route;
660 struct net_device *dev;
661 ax25_digi digi;
662 int ret;
663
664 switch (cmd) {
665 case SIOCADDRT:
666 if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
667 return -EFAULT;
668 if (nr_route.ndigis > AX25_MAX_DIGIS)
669 return -EINVAL;
670 if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
671 return -EINVAL;
672 switch (nr_route.type) {
673 case NETROM_NODE:
674 if (strnlen(nr_route.mnemonic, 7) == 7) {
675 ret = -EINVAL;
676 break;
677 }
678
679 ret = nr_add_node(&nr_route.callsign,
680 nr_route.mnemonic,
681 &nr_route.neighbour,
682 nr_call_to_digi(&digi, nr_route.ndigis,
683 nr_route.digipeaters),
684 dev, nr_route.quality,
685 nr_route.obs_count);
686 break;
687 case NETROM_NEIGH:
688 ret = nr_add_neigh(&nr_route.callsign,
689 nr_call_to_digi(&digi, nr_route.ndigis,
690 nr_route.digipeaters),
691 dev, nr_route.quality);
692 break;
693 default:
694 ret = -EINVAL;
695 }
696 dev_put(dev);
697 return ret;
698
699 case SIOCDELRT:
700 if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
701 return -EFAULT;
702 if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
703 return -EINVAL;
704 switch (nr_route.type) {
705 case NETROM_NODE:
706 ret = nr_del_node(&nr_route.callsign,
707 &nr_route.neighbour, dev);
708 break;
709 case NETROM_NEIGH:
710 ret = nr_del_neigh(&nr_route.callsign,
711 dev, nr_route.quality);
712 break;
713 default:
714 ret = -EINVAL;
715 }
716 dev_put(dev);
717 return ret;
718
719 case SIOCNRDECOBS:
720 return nr_dec_obs();
721
722 default:
723 return -EINVAL;
724 }
725
726 return 0;
727}
728
729/*
730 * A level 2 link has timed out, therefore it appears to be a poor link,
731 * then don't use that neighbour until it is reset.
732 */
733void nr_link_failed(ax25_cb *ax25, int reason)
734{
735 struct nr_neigh *s, *nr_neigh = NULL;
736 struct nr_node *nr_node = NULL;
737
738 spin_lock_bh(&nr_neigh_list_lock);
739 nr_neigh_for_each(s, &nr_neigh_list) {
740 if (s->ax25 == ax25) {
741 nr_neigh_hold(s);
742 nr_neigh = s;
743 break;
744 }
745 }
746 spin_unlock_bh(&nr_neigh_list_lock);
747
748 if (nr_neigh == NULL)
749 return;
750
751 nr_neigh->ax25 = NULL;
752 ax25_cb_put(ax25);
753
754 if (++nr_neigh->failed < sysctl_netrom_link_fails_count) {
755 nr_neigh_put(nr_neigh);
756 return;
757 }
758 spin_lock_bh(&nr_node_list_lock);
759 nr_node_for_each(nr_node, &nr_node_list) {
760 nr_node_lock(nr_node);
761 if (nr_node->which < nr_node->count &&
762 nr_node->routes[nr_node->which].neighbour == nr_neigh)
763 nr_node->which++;
764 nr_node_unlock(nr_node);
765 }
766 spin_unlock_bh(&nr_node_list_lock);
767 nr_neigh_put(nr_neigh);
768}
769
770/*
771 * Route a frame to an appropriate AX.25 connection. A NULL ax25_cb
772 * indicates an internally generated frame.
773 */
774int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
775{
776 ax25_address *nr_src, *nr_dest;
777 struct nr_neigh *nr_neigh;
778 struct nr_node *nr_node;
779 struct net_device *dev;
780 unsigned char *dptr;
781 ax25_cb *ax25s;
782 int ret;
783 struct sk_buff *skbn;
784
785
786 nr_src = (ax25_address *)(skb->data + 0);
787 nr_dest = (ax25_address *)(skb->data + 7);
788
789 if (ax25 != NULL) {
790 ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
791 ax25->ax25_dev->dev, 0,
792 sysctl_netrom_obsolescence_count_initialiser);
793 if (ret)
794 return ret;
795 }
796
797 if ((dev = nr_dev_get(nr_dest)) != NULL) { /* Its for me */
798 if (ax25 == NULL) /* Its from me */
799 ret = nr_loopback_queue(skb);
800 else
801 ret = nr_rx_frame(skb, dev);
802 dev_put(dev);
803 return ret;
804 }
805
806 if (!sysctl_netrom_routing_control && ax25 != NULL)
807 return 0;
808
809 /* Its Time-To-Live has expired */
810 if (skb->data[14] == 1) {
811 return 0;
812 }
813
814 nr_node = nr_node_get(nr_dest);
815 if (nr_node == NULL)
816 return 0;
817 nr_node_lock(nr_node);
818
819 if (nr_node->which >= nr_node->count) {
820 nr_node_unlock(nr_node);
821 nr_node_put(nr_node);
822 return 0;
823 }
824
825 nr_neigh = nr_node->routes[nr_node->which].neighbour;
826
827 if ((dev = nr_dev_first()) == NULL) {
828 nr_node_unlock(nr_node);
829 nr_node_put(nr_node);
830 return 0;
831 }
832
833 /* We are going to change the netrom headers so we should get our
834 own skb, we also did not know until now how much header space
835 we had to reserve... - RXQ */
836 if ((skbn=skb_copy_expand(skb, dev->hard_header_len, 0, GFP_ATOMIC)) == NULL) {
837 nr_node_unlock(nr_node);
838 nr_node_put(nr_node);
839 dev_put(dev);
840 return 0;
841 }
842 kfree_skb(skb);
843 skb=skbn;
844 skb->data[14]--;
845
846 dptr = skb_push(skb, 1);
847 *dptr = AX25_P_NETROM;
848
849 ax25s = nr_neigh->ax25;
850 nr_neigh->ax25 = ax25_send_frame(skb, 256,
851 (ax25_address *)dev->dev_addr,
852 &nr_neigh->callsign,
853 nr_neigh->digipeat, nr_neigh->dev);
854 if (ax25s)
855 ax25_cb_put(ax25s);
856
857 dev_put(dev);
858 ret = (nr_neigh->ax25 != NULL);
859 nr_node_unlock(nr_node);
860 nr_node_put(nr_node);
861
862 return ret;
863}
864
865#ifdef CONFIG_PROC_FS
866
867static void *nr_node_start(struct seq_file *seq, loff_t *pos)
868{
869 spin_lock_bh(&nr_node_list_lock);
870 return seq_hlist_start_head(&nr_node_list, *pos);
871}
872
873static void *nr_node_next(struct seq_file *seq, void *v, loff_t *pos)
874{
875 return seq_hlist_next(v, &nr_node_list, pos);
876}
877
878static void nr_node_stop(struct seq_file *seq, void *v)
879{
880 spin_unlock_bh(&nr_node_list_lock);
881}
882
883static int nr_node_show(struct seq_file *seq, void *v)
884{
885 char buf[11];
886 int i;
887
888 if (v == SEQ_START_TOKEN)
889 seq_puts(seq,
890 "callsign mnemonic w n qual obs neigh qual obs neigh qual obs neigh\n");
891 else {
892 struct nr_node *nr_node = hlist_entry(v, struct nr_node,
893 node_node);
894
895 nr_node_lock(nr_node);
896 seq_printf(seq, "%-9s %-7s %d %d",
897 ax2asc(buf, &nr_node->callsign),
898 (nr_node->mnemonic[0] == '\0') ? "*" : nr_node->mnemonic,
899 nr_node->which + 1,
900 nr_node->count);
901
902 for (i = 0; i < nr_node->count; i++) {
903 seq_printf(seq, " %3d %d %05d",
904 nr_node->routes[i].quality,
905 nr_node->routes[i].obs_count,
906 nr_node->routes[i].neighbour->number);
907 }
908 nr_node_unlock(nr_node);
909
910 seq_puts(seq, "\n");
911 }
912 return 0;
913}
914
915static const struct seq_operations nr_node_seqops = {
916 .start = nr_node_start,
917 .next = nr_node_next,
918 .stop = nr_node_stop,
919 .show = nr_node_show,
920};
921
922static int nr_node_info_open(struct inode *inode, struct file *file)
923{
924 return seq_open(file, &nr_node_seqops);
925}
926
927const struct file_operations nr_nodes_fops = {
928 .owner = THIS_MODULE,
929 .open = nr_node_info_open,
930 .read = seq_read,
931 .llseek = seq_lseek,
932 .release = seq_release,
933};
934
935static void *nr_neigh_start(struct seq_file *seq, loff_t *pos)
936{
937 spin_lock_bh(&nr_neigh_list_lock);
938 return seq_hlist_start_head(&nr_neigh_list, *pos);
939}
940
941static void *nr_neigh_next(struct seq_file *seq, void *v, loff_t *pos)
942{
943 return seq_hlist_next(v, &nr_neigh_list, pos);
944}
945
946static void nr_neigh_stop(struct seq_file *seq, void *v)
947{
948 spin_unlock_bh(&nr_neigh_list_lock);
949}
950
951static int nr_neigh_show(struct seq_file *seq, void *v)
952{
953 char buf[11];
954 int i;
955
956 if (v == SEQ_START_TOKEN)
957 seq_puts(seq, "addr callsign dev qual lock count failed digipeaters\n");
958 else {
959 struct nr_neigh *nr_neigh;
960
961 nr_neigh = hlist_entry(v, struct nr_neigh, neigh_node);
962 seq_printf(seq, "%05d %-9s %-4s %3d %d %3d %3d",
963 nr_neigh->number,
964 ax2asc(buf, &nr_neigh->callsign),
965 nr_neigh->dev ? nr_neigh->dev->name : "???",
966 nr_neigh->quality,
967 nr_neigh->locked,
968 nr_neigh->count,
969 nr_neigh->failed);
970
971 if (nr_neigh->digipeat != NULL) {
972 for (i = 0; i < nr_neigh->digipeat->ndigi; i++)
973 seq_printf(seq, " %s",
974 ax2asc(buf, &nr_neigh->digipeat->calls[i]));
975 }
976
977 seq_puts(seq, "\n");
978 }
979 return 0;
980}
981
982static const struct seq_operations nr_neigh_seqops = {
983 .start = nr_neigh_start,
984 .next = nr_neigh_next,
985 .stop = nr_neigh_stop,
986 .show = nr_neigh_show,
987};
988
989static int nr_neigh_info_open(struct inode *inode, struct file *file)
990{
991 return seq_open(file, &nr_neigh_seqops);
992}
993
994const struct file_operations nr_neigh_fops = {
995 .owner = THIS_MODULE,
996 .open = nr_neigh_info_open,
997 .read = seq_read,
998 .llseek = seq_lseek,
999 .release = seq_release,
1000};
1001
1002#endif
1003
1004/*
1005 * Free all memory associated with the nodes and routes lists.
1006 */
1007void __exit nr_rt_free(void)
1008{
1009 struct nr_neigh *s = NULL;
1010 struct nr_node *t = NULL;
1011 struct hlist_node *nodet;
1012
1013 spin_lock_bh(&nr_neigh_list_lock);
1014 spin_lock_bh(&nr_node_list_lock);
1015 nr_node_for_each_safe(t, nodet, &nr_node_list) {
1016 nr_node_lock(t);
1017 nr_remove_node_locked(t);
1018 nr_node_unlock(t);
1019 }
1020 nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
1021 while(s->count) {
1022 s->count--;
1023 nr_neigh_put(s);
1024 }
1025 nr_remove_neigh_locked(s);
1026 }
1027 spin_unlock_bh(&nr_node_list_lock);
1028 spin_unlock_bh(&nr_neigh_list_lock);
1029}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5 * Copyright Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
6 * Copyright Tomi Manninen OH2BNS (oh2bns@sral.fi)
7 */
8#include <linux/errno.h>
9#include <linux/types.h>
10#include <linux/socket.h>
11#include <linux/in.h>
12#include <linux/kernel.h>
13#include <linux/timer.h>
14#include <linux/string.h>
15#include <linux/sockios.h>
16#include <linux/net.h>
17#include <linux/slab.h>
18#include <net/ax25.h>
19#include <linux/inet.h>
20#include <linux/netdevice.h>
21#include <net/arp.h>
22#include <linux/if_arp.h>
23#include <linux/skbuff.h>
24#include <net/sock.h>
25#include <linux/uaccess.h>
26#include <linux/fcntl.h>
27#include <linux/termios.h> /* For TIOCINQ/OUTQ */
28#include <linux/mm.h>
29#include <linux/interrupt.h>
30#include <linux/notifier.h>
31#include <linux/init.h>
32#include <linux/spinlock.h>
33#include <net/netrom.h>
34#include <linux/seq_file.h>
35#include <linux/export.h>
36
37static unsigned int nr_neigh_no = 1;
38
39static HLIST_HEAD(nr_node_list);
40static DEFINE_SPINLOCK(nr_node_list_lock);
41static HLIST_HEAD(nr_neigh_list);
42static DEFINE_SPINLOCK(nr_neigh_list_lock);
43
44static struct nr_node *nr_node_get(ax25_address *callsign)
45{
46 struct nr_node *found = NULL;
47 struct nr_node *nr_node;
48
49 spin_lock_bh(&nr_node_list_lock);
50 nr_node_for_each(nr_node, &nr_node_list)
51 if (ax25cmp(callsign, &nr_node->callsign) == 0) {
52 nr_node_hold(nr_node);
53 found = nr_node;
54 break;
55 }
56 spin_unlock_bh(&nr_node_list_lock);
57 return found;
58}
59
60static struct nr_neigh *nr_neigh_get_dev(ax25_address *callsign,
61 struct net_device *dev)
62{
63 struct nr_neigh *found = NULL;
64 struct nr_neigh *nr_neigh;
65
66 spin_lock_bh(&nr_neigh_list_lock);
67 nr_neigh_for_each(nr_neigh, &nr_neigh_list)
68 if (ax25cmp(callsign, &nr_neigh->callsign) == 0 &&
69 nr_neigh->dev == dev) {
70 nr_neigh_hold(nr_neigh);
71 found = nr_neigh;
72 break;
73 }
74 spin_unlock_bh(&nr_neigh_list_lock);
75 return found;
76}
77
78static void nr_remove_neigh(struct nr_neigh *);
79
80/* re-sort the routes in quality order. */
81static void re_sort_routes(struct nr_node *nr_node, int x, int y)
82{
83 if (nr_node->routes[y].quality > nr_node->routes[x].quality) {
84 if (nr_node->which == x)
85 nr_node->which = y;
86 else if (nr_node->which == y)
87 nr_node->which = x;
88
89 swap(nr_node->routes[x], nr_node->routes[y]);
90 }
91}
92
93/*
94 * Add a new route to a node, and in the process add the node and the
95 * neighbour if it is new.
96 */
97static int __must_check nr_add_node(ax25_address *nr, const char *mnemonic,
98 ax25_address *ax25, ax25_digi *ax25_digi, struct net_device *dev,
99 int quality, int obs_count)
100{
101 struct nr_node *nr_node;
102 struct nr_neigh *nr_neigh;
103 int i, found;
104 struct net_device *odev;
105
106 if ((odev=nr_dev_get(nr)) != NULL) { /* Can't add routes to ourself */
107 dev_put(odev);
108 return -EINVAL;
109 }
110
111 nr_node = nr_node_get(nr);
112
113 nr_neigh = nr_neigh_get_dev(ax25, dev);
114
115 /*
116 * The L2 link to a neighbour has failed in the past
117 * and now a frame comes from this neighbour. We assume
118 * it was a temporary trouble with the link and reset the
119 * routes now (and not wait for a node broadcast).
120 */
121 if (nr_neigh != NULL && nr_neigh->failed != 0 && quality == 0) {
122 struct nr_node *nr_nodet;
123
124 spin_lock_bh(&nr_node_list_lock);
125 nr_node_for_each(nr_nodet, &nr_node_list) {
126 nr_node_lock(nr_nodet);
127 for (i = 0; i < nr_nodet->count; i++)
128 if (nr_nodet->routes[i].neighbour == nr_neigh)
129 if (i < nr_nodet->which)
130 nr_nodet->which = i;
131 nr_node_unlock(nr_nodet);
132 }
133 spin_unlock_bh(&nr_node_list_lock);
134 }
135
136 if (nr_neigh != NULL)
137 nr_neigh->failed = 0;
138
139 if (quality == 0 && nr_neigh != NULL && nr_node != NULL) {
140 nr_neigh_put(nr_neigh);
141 nr_node_put(nr_node);
142 return 0;
143 }
144
145 if (nr_neigh == NULL) {
146 if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL) {
147 if (nr_node)
148 nr_node_put(nr_node);
149 return -ENOMEM;
150 }
151
152 nr_neigh->callsign = *ax25;
153 nr_neigh->digipeat = NULL;
154 nr_neigh->ax25 = NULL;
155 nr_neigh->dev = dev;
156 nr_neigh->quality = sysctl_netrom_default_path_quality;
157 nr_neigh->locked = 0;
158 nr_neigh->count = 0;
159 nr_neigh->number = nr_neigh_no++;
160 nr_neigh->failed = 0;
161 refcount_set(&nr_neigh->refcount, 1);
162
163 if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
164 nr_neigh->digipeat = kmemdup(ax25_digi,
165 sizeof(*ax25_digi),
166 GFP_KERNEL);
167 if (nr_neigh->digipeat == NULL) {
168 kfree(nr_neigh);
169 if (nr_node)
170 nr_node_put(nr_node);
171 return -ENOMEM;
172 }
173 }
174
175 spin_lock_bh(&nr_neigh_list_lock);
176 hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
177 nr_neigh_hold(nr_neigh);
178 spin_unlock_bh(&nr_neigh_list_lock);
179 }
180
181 if (quality != 0 && ax25cmp(nr, ax25) == 0 && !nr_neigh->locked)
182 nr_neigh->quality = quality;
183
184 if (nr_node == NULL) {
185 if ((nr_node = kmalloc(sizeof(*nr_node), GFP_ATOMIC)) == NULL) {
186 if (nr_neigh)
187 nr_neigh_put(nr_neigh);
188 return -ENOMEM;
189 }
190
191 nr_node->callsign = *nr;
192 strcpy(nr_node->mnemonic, mnemonic);
193
194 nr_node->which = 0;
195 nr_node->count = 1;
196 refcount_set(&nr_node->refcount, 1);
197 spin_lock_init(&nr_node->node_lock);
198
199 nr_node->routes[0].quality = quality;
200 nr_node->routes[0].obs_count = obs_count;
201 nr_node->routes[0].neighbour = nr_neigh;
202
203 nr_neigh_hold(nr_neigh);
204 nr_neigh->count++;
205
206 spin_lock_bh(&nr_node_list_lock);
207 hlist_add_head(&nr_node->node_node, &nr_node_list);
208 /* refcount initialized at 1 */
209 spin_unlock_bh(&nr_node_list_lock);
210
211 nr_neigh_put(nr_neigh);
212 return 0;
213 }
214 nr_node_lock(nr_node);
215
216 if (quality != 0)
217 strcpy(nr_node->mnemonic, mnemonic);
218
219 for (found = 0, i = 0; i < nr_node->count; i++) {
220 if (nr_node->routes[i].neighbour == nr_neigh) {
221 nr_node->routes[i].quality = quality;
222 nr_node->routes[i].obs_count = obs_count;
223 found = 1;
224 break;
225 }
226 }
227
228 if (!found) {
229 /* We have space at the bottom, slot it in */
230 if (nr_node->count < 3) {
231 nr_node->routes[2] = nr_node->routes[1];
232 nr_node->routes[1] = nr_node->routes[0];
233
234 nr_node->routes[0].quality = quality;
235 nr_node->routes[0].obs_count = obs_count;
236 nr_node->routes[0].neighbour = nr_neigh;
237
238 nr_node->which++;
239 nr_node->count++;
240 nr_neigh_hold(nr_neigh);
241 nr_neigh->count++;
242 } else {
243 /* It must be better than the worst */
244 if (quality > nr_node->routes[2].quality) {
245 nr_node->routes[2].neighbour->count--;
246 nr_neigh_put(nr_node->routes[2].neighbour);
247
248 if (nr_node->routes[2].neighbour->count == 0 && !nr_node->routes[2].neighbour->locked)
249 nr_remove_neigh(nr_node->routes[2].neighbour);
250
251 nr_node->routes[2].quality = quality;
252 nr_node->routes[2].obs_count = obs_count;
253 nr_node->routes[2].neighbour = nr_neigh;
254
255 nr_neigh_hold(nr_neigh);
256 nr_neigh->count++;
257 }
258 }
259 }
260
261 /* Now re-sort the routes in quality order */
262 switch (nr_node->count) {
263 case 3:
264 re_sort_routes(nr_node, 0, 1);
265 re_sort_routes(nr_node, 1, 2);
266 fallthrough;
267 case 2:
268 re_sort_routes(nr_node, 0, 1);
269 break;
270 case 1:
271 break;
272 }
273
274 for (i = 0; i < nr_node->count; i++) {
275 if (nr_node->routes[i].neighbour == nr_neigh) {
276 if (i < nr_node->which)
277 nr_node->which = i;
278 break;
279 }
280 }
281
282 nr_neigh_put(nr_neigh);
283 nr_node_unlock(nr_node);
284 nr_node_put(nr_node);
285 return 0;
286}
287
288static inline void __nr_remove_node(struct nr_node *nr_node)
289{
290 hlist_del_init(&nr_node->node_node);
291 nr_node_put(nr_node);
292}
293
294#define nr_remove_node_locked(__node) \
295 __nr_remove_node(__node)
296
297static void nr_remove_node(struct nr_node *nr_node)
298{
299 spin_lock_bh(&nr_node_list_lock);
300 __nr_remove_node(nr_node);
301 spin_unlock_bh(&nr_node_list_lock);
302}
303
304static inline void __nr_remove_neigh(struct nr_neigh *nr_neigh)
305{
306 hlist_del_init(&nr_neigh->neigh_node);
307 nr_neigh_put(nr_neigh);
308}
309
310#define nr_remove_neigh_locked(__neigh) \
311 __nr_remove_neigh(__neigh)
312
313static void nr_remove_neigh(struct nr_neigh *nr_neigh)
314{
315 spin_lock_bh(&nr_neigh_list_lock);
316 __nr_remove_neigh(nr_neigh);
317 spin_unlock_bh(&nr_neigh_list_lock);
318}
319
320/*
321 * "Delete" a node. Strictly speaking remove a route to a node. The node
322 * is only deleted if no routes are left to it.
323 */
324static int nr_del_node(ax25_address *callsign, ax25_address *neighbour, struct net_device *dev)
325{
326 struct nr_node *nr_node;
327 struct nr_neigh *nr_neigh;
328 int i;
329
330 nr_node = nr_node_get(callsign);
331
332 if (nr_node == NULL)
333 return -EINVAL;
334
335 nr_neigh = nr_neigh_get_dev(neighbour, dev);
336
337 if (nr_neigh == NULL) {
338 nr_node_put(nr_node);
339 return -EINVAL;
340 }
341
342 nr_node_lock(nr_node);
343 for (i = 0; i < nr_node->count; i++) {
344 if (nr_node->routes[i].neighbour == nr_neigh) {
345 nr_neigh->count--;
346 nr_neigh_put(nr_neigh);
347
348 if (nr_neigh->count == 0 && !nr_neigh->locked)
349 nr_remove_neigh(nr_neigh);
350 nr_neigh_put(nr_neigh);
351
352 nr_node->count--;
353
354 if (nr_node->count == 0) {
355 nr_remove_node(nr_node);
356 } else {
357 switch (i) {
358 case 0:
359 nr_node->routes[0] = nr_node->routes[1];
360 fallthrough;
361 case 1:
362 nr_node->routes[1] = nr_node->routes[2];
363 fallthrough;
364 case 2:
365 break;
366 }
367 nr_node_put(nr_node);
368 }
369 nr_node_unlock(nr_node);
370
371 return 0;
372 }
373 }
374 nr_neigh_put(nr_neigh);
375 nr_node_unlock(nr_node);
376 nr_node_put(nr_node);
377
378 return -EINVAL;
379}
380
381/*
382 * Lock a neighbour with a quality.
383 */
384static int __must_check nr_add_neigh(ax25_address *callsign,
385 ax25_digi *ax25_digi, struct net_device *dev, unsigned int quality)
386{
387 struct nr_neigh *nr_neigh;
388
389 nr_neigh = nr_neigh_get_dev(callsign, dev);
390 if (nr_neigh) {
391 nr_neigh->quality = quality;
392 nr_neigh->locked = 1;
393 nr_neigh_put(nr_neigh);
394 return 0;
395 }
396
397 if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL)
398 return -ENOMEM;
399
400 nr_neigh->callsign = *callsign;
401 nr_neigh->digipeat = NULL;
402 nr_neigh->ax25 = NULL;
403 nr_neigh->dev = dev;
404 nr_neigh->quality = quality;
405 nr_neigh->locked = 1;
406 nr_neigh->count = 0;
407 nr_neigh->number = nr_neigh_no++;
408 nr_neigh->failed = 0;
409 refcount_set(&nr_neigh->refcount, 1);
410
411 if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
412 nr_neigh->digipeat = kmemdup(ax25_digi, sizeof(*ax25_digi),
413 GFP_KERNEL);
414 if (nr_neigh->digipeat == NULL) {
415 kfree(nr_neigh);
416 return -ENOMEM;
417 }
418 }
419
420 spin_lock_bh(&nr_neigh_list_lock);
421 hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
422 /* refcount is initialized at 1 */
423 spin_unlock_bh(&nr_neigh_list_lock);
424
425 return 0;
426}
427
428/*
429 * "Delete" a neighbour. The neighbour is only removed if the number
430 * of nodes that may use it is zero.
431 */
432static int nr_del_neigh(ax25_address *callsign, struct net_device *dev, unsigned int quality)
433{
434 struct nr_neigh *nr_neigh;
435
436 nr_neigh = nr_neigh_get_dev(callsign, dev);
437
438 if (nr_neigh == NULL) return -EINVAL;
439
440 nr_neigh->quality = quality;
441 nr_neigh->locked = 0;
442
443 if (nr_neigh->count == 0)
444 nr_remove_neigh(nr_neigh);
445 nr_neigh_put(nr_neigh);
446
447 return 0;
448}
449
450/*
451 * Decrement the obsolescence count by one. If a route is reduced to a
452 * count of zero, remove it. Also remove any unlocked neighbours with
453 * zero nodes routing via it.
454 */
455static int nr_dec_obs(void)
456{
457 struct nr_neigh *nr_neigh;
458 struct nr_node *s;
459 struct hlist_node *nodet;
460 int i;
461
462 spin_lock_bh(&nr_node_list_lock);
463 nr_node_for_each_safe(s, nodet, &nr_node_list) {
464 nr_node_lock(s);
465 for (i = 0; i < s->count; i++) {
466 switch (s->routes[i].obs_count) {
467 case 0: /* A locked entry */
468 break;
469
470 case 1: /* From 1 -> 0 */
471 nr_neigh = s->routes[i].neighbour;
472
473 nr_neigh->count--;
474 nr_neigh_put(nr_neigh);
475
476 if (nr_neigh->count == 0 && !nr_neigh->locked)
477 nr_remove_neigh(nr_neigh);
478
479 s->count--;
480
481 switch (i) {
482 case 0:
483 s->routes[0] = s->routes[1];
484 fallthrough;
485 case 1:
486 s->routes[1] = s->routes[2];
487 break;
488 case 2:
489 break;
490 }
491 break;
492
493 default:
494 s->routes[i].obs_count--;
495 break;
496
497 }
498 }
499
500 if (s->count <= 0)
501 nr_remove_node_locked(s);
502 nr_node_unlock(s);
503 }
504 spin_unlock_bh(&nr_node_list_lock);
505
506 return 0;
507}
508
509/*
510 * A device has been removed. Remove its routes and neighbours.
511 */
512void nr_rt_device_down(struct net_device *dev)
513{
514 struct nr_neigh *s;
515 struct hlist_node *nodet, *node2t;
516 struct nr_node *t;
517 int i;
518
519 spin_lock_bh(&nr_neigh_list_lock);
520 nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
521 if (s->dev == dev) {
522 spin_lock_bh(&nr_node_list_lock);
523 nr_node_for_each_safe(t, node2t, &nr_node_list) {
524 nr_node_lock(t);
525 for (i = 0; i < t->count; i++) {
526 if (t->routes[i].neighbour == s) {
527 t->count--;
528
529 switch (i) {
530 case 0:
531 t->routes[0] = t->routes[1];
532 fallthrough;
533 case 1:
534 t->routes[1] = t->routes[2];
535 break;
536 case 2:
537 break;
538 }
539 }
540 }
541
542 if (t->count <= 0)
543 nr_remove_node_locked(t);
544 nr_node_unlock(t);
545 }
546 spin_unlock_bh(&nr_node_list_lock);
547
548 nr_remove_neigh_locked(s);
549 }
550 }
551 spin_unlock_bh(&nr_neigh_list_lock);
552}
553
554/*
555 * Check that the device given is a valid AX.25 interface that is "up".
556 * Or a valid ethernet interface with an AX.25 callsign binding.
557 */
558static struct net_device *nr_ax25_dev_get(char *devname)
559{
560 struct net_device *dev;
561
562 if ((dev = dev_get_by_name(&init_net, devname)) == NULL)
563 return NULL;
564
565 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_AX25)
566 return dev;
567
568 dev_put(dev);
569 return NULL;
570}
571
572/*
573 * Find the first active NET/ROM device, usually "nr0".
574 */
575struct net_device *nr_dev_first(void)
576{
577 struct net_device *dev, *first = NULL;
578
579 rcu_read_lock();
580 for_each_netdev_rcu(&init_net, dev) {
581 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM)
582 if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
583 first = dev;
584 }
585 dev_hold(first);
586 rcu_read_unlock();
587
588 return first;
589}
590
591/*
592 * Find the NET/ROM device for the given callsign.
593 */
594struct net_device *nr_dev_get(ax25_address *addr)
595{
596 struct net_device *dev;
597
598 rcu_read_lock();
599 for_each_netdev_rcu(&init_net, dev) {
600 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM &&
601 ax25cmp(addr, (const ax25_address *)dev->dev_addr) == 0) {
602 dev_hold(dev);
603 goto out;
604 }
605 }
606 dev = NULL;
607out:
608 rcu_read_unlock();
609 return dev;
610}
611
612static ax25_digi *nr_call_to_digi(ax25_digi *digi, int ndigis,
613 ax25_address *digipeaters)
614{
615 int i;
616
617 if (ndigis == 0)
618 return NULL;
619
620 for (i = 0; i < ndigis; i++) {
621 digi->calls[i] = digipeaters[i];
622 digi->repeated[i] = 0;
623 }
624
625 digi->ndigi = ndigis;
626 digi->lastrepeat = -1;
627
628 return digi;
629}
630
631/*
632 * Handle the ioctls that control the routing functions.
633 */
634int nr_rt_ioctl(unsigned int cmd, void __user *arg)
635{
636 struct nr_route_struct nr_route;
637 struct net_device *dev;
638 ax25_digi digi;
639 int ret;
640
641 switch (cmd) {
642 case SIOCADDRT:
643 if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
644 return -EFAULT;
645 if (nr_route.ndigis > AX25_MAX_DIGIS)
646 return -EINVAL;
647 if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
648 return -EINVAL;
649 switch (nr_route.type) {
650 case NETROM_NODE:
651 if (strnlen(nr_route.mnemonic, 7) == 7) {
652 ret = -EINVAL;
653 break;
654 }
655
656 ret = nr_add_node(&nr_route.callsign,
657 nr_route.mnemonic,
658 &nr_route.neighbour,
659 nr_call_to_digi(&digi, nr_route.ndigis,
660 nr_route.digipeaters),
661 dev, nr_route.quality,
662 nr_route.obs_count);
663 break;
664 case NETROM_NEIGH:
665 ret = nr_add_neigh(&nr_route.callsign,
666 nr_call_to_digi(&digi, nr_route.ndigis,
667 nr_route.digipeaters),
668 dev, nr_route.quality);
669 break;
670 default:
671 ret = -EINVAL;
672 }
673 dev_put(dev);
674 return ret;
675
676 case SIOCDELRT:
677 if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
678 return -EFAULT;
679 if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
680 return -EINVAL;
681 switch (nr_route.type) {
682 case NETROM_NODE:
683 ret = nr_del_node(&nr_route.callsign,
684 &nr_route.neighbour, dev);
685 break;
686 case NETROM_NEIGH:
687 ret = nr_del_neigh(&nr_route.callsign,
688 dev, nr_route.quality);
689 break;
690 default:
691 ret = -EINVAL;
692 }
693 dev_put(dev);
694 return ret;
695
696 case SIOCNRDECOBS:
697 return nr_dec_obs();
698
699 default:
700 return -EINVAL;
701 }
702
703 return 0;
704}
705
706/*
707 * A level 2 link has timed out, therefore it appears to be a poor link,
708 * then don't use that neighbour until it is reset.
709 */
710void nr_link_failed(ax25_cb *ax25, int reason)
711{
712 struct nr_neigh *s, *nr_neigh = NULL;
713 struct nr_node *nr_node = NULL;
714
715 spin_lock_bh(&nr_neigh_list_lock);
716 nr_neigh_for_each(s, &nr_neigh_list) {
717 if (s->ax25 == ax25) {
718 nr_neigh_hold(s);
719 nr_neigh = s;
720 break;
721 }
722 }
723 spin_unlock_bh(&nr_neigh_list_lock);
724
725 if (nr_neigh == NULL)
726 return;
727
728 nr_neigh->ax25 = NULL;
729 ax25_cb_put(ax25);
730
731 if (++nr_neigh->failed < sysctl_netrom_link_fails_count) {
732 nr_neigh_put(nr_neigh);
733 return;
734 }
735 spin_lock_bh(&nr_node_list_lock);
736 nr_node_for_each(nr_node, &nr_node_list) {
737 nr_node_lock(nr_node);
738 if (nr_node->which < nr_node->count &&
739 nr_node->routes[nr_node->which].neighbour == nr_neigh)
740 nr_node->which++;
741 nr_node_unlock(nr_node);
742 }
743 spin_unlock_bh(&nr_node_list_lock);
744 nr_neigh_put(nr_neigh);
745}
746
747/*
748 * Route a frame to an appropriate AX.25 connection. A NULL ax25_cb
749 * indicates an internally generated frame.
750 */
751int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
752{
753 ax25_address *nr_src, *nr_dest;
754 struct nr_neigh *nr_neigh;
755 struct nr_node *nr_node;
756 struct net_device *dev;
757 unsigned char *dptr;
758 ax25_cb *ax25s;
759 int ret;
760 struct sk_buff *skbn;
761
762
763 nr_src = (ax25_address *)(skb->data + 0);
764 nr_dest = (ax25_address *)(skb->data + 7);
765
766 if (ax25 != NULL) {
767 ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
768 ax25->ax25_dev->dev, 0,
769 sysctl_netrom_obsolescence_count_initialiser);
770 if (ret)
771 return ret;
772 }
773
774 if ((dev = nr_dev_get(nr_dest)) != NULL) { /* Its for me */
775 if (ax25 == NULL) /* Its from me */
776 ret = nr_loopback_queue(skb);
777 else
778 ret = nr_rx_frame(skb, dev);
779 dev_put(dev);
780 return ret;
781 }
782
783 if (!sysctl_netrom_routing_control && ax25 != NULL)
784 return 0;
785
786 /* Its Time-To-Live has expired */
787 if (skb->data[14] == 1) {
788 return 0;
789 }
790
791 nr_node = nr_node_get(nr_dest);
792 if (nr_node == NULL)
793 return 0;
794 nr_node_lock(nr_node);
795
796 if (nr_node->which >= nr_node->count) {
797 nr_node_unlock(nr_node);
798 nr_node_put(nr_node);
799 return 0;
800 }
801
802 nr_neigh = nr_node->routes[nr_node->which].neighbour;
803
804 if ((dev = nr_dev_first()) == NULL) {
805 nr_node_unlock(nr_node);
806 nr_node_put(nr_node);
807 return 0;
808 }
809
810 /* We are going to change the netrom headers so we should get our
811 own skb, we also did not know until now how much header space
812 we had to reserve... - RXQ */
813 if ((skbn=skb_copy_expand(skb, dev->hard_header_len, 0, GFP_ATOMIC)) == NULL) {
814 nr_node_unlock(nr_node);
815 nr_node_put(nr_node);
816 dev_put(dev);
817 return 0;
818 }
819 kfree_skb(skb);
820 skb=skbn;
821 skb->data[14]--;
822
823 dptr = skb_push(skb, 1);
824 *dptr = AX25_P_NETROM;
825
826 ax25s = nr_neigh->ax25;
827 nr_neigh->ax25 = ax25_send_frame(skb, 256,
828 (const ax25_address *)dev->dev_addr,
829 &nr_neigh->callsign,
830 nr_neigh->digipeat, nr_neigh->dev);
831 if (ax25s)
832 ax25_cb_put(ax25s);
833
834 dev_put(dev);
835 ret = (nr_neigh->ax25 != NULL);
836 nr_node_unlock(nr_node);
837 nr_node_put(nr_node);
838
839 return ret;
840}
841
842#ifdef CONFIG_PROC_FS
843
844static void *nr_node_start(struct seq_file *seq, loff_t *pos)
845 __acquires(&nr_node_list_lock)
846{
847 spin_lock_bh(&nr_node_list_lock);
848 return seq_hlist_start_head(&nr_node_list, *pos);
849}
850
851static void *nr_node_next(struct seq_file *seq, void *v, loff_t *pos)
852{
853 return seq_hlist_next(v, &nr_node_list, pos);
854}
855
856static void nr_node_stop(struct seq_file *seq, void *v)
857 __releases(&nr_node_list_lock)
858{
859 spin_unlock_bh(&nr_node_list_lock);
860}
861
862static int nr_node_show(struct seq_file *seq, void *v)
863{
864 char buf[11];
865 int i;
866
867 if (v == SEQ_START_TOKEN)
868 seq_puts(seq,
869 "callsign mnemonic w n qual obs neigh qual obs neigh qual obs neigh\n");
870 else {
871 struct nr_node *nr_node = hlist_entry(v, struct nr_node,
872 node_node);
873
874 nr_node_lock(nr_node);
875 seq_printf(seq, "%-9s %-7s %d %d",
876 ax2asc(buf, &nr_node->callsign),
877 (nr_node->mnemonic[0] == '\0') ? "*" : nr_node->mnemonic,
878 nr_node->which + 1,
879 nr_node->count);
880
881 for (i = 0; i < nr_node->count; i++) {
882 seq_printf(seq, " %3d %d %05d",
883 nr_node->routes[i].quality,
884 nr_node->routes[i].obs_count,
885 nr_node->routes[i].neighbour->number);
886 }
887 nr_node_unlock(nr_node);
888
889 seq_puts(seq, "\n");
890 }
891 return 0;
892}
893
894const struct seq_operations nr_node_seqops = {
895 .start = nr_node_start,
896 .next = nr_node_next,
897 .stop = nr_node_stop,
898 .show = nr_node_show,
899};
900
901static void *nr_neigh_start(struct seq_file *seq, loff_t *pos)
902 __acquires(&nr_neigh_list_lock)
903{
904 spin_lock_bh(&nr_neigh_list_lock);
905 return seq_hlist_start_head(&nr_neigh_list, *pos);
906}
907
908static void *nr_neigh_next(struct seq_file *seq, void *v, loff_t *pos)
909{
910 return seq_hlist_next(v, &nr_neigh_list, pos);
911}
912
913static void nr_neigh_stop(struct seq_file *seq, void *v)
914 __releases(&nr_neigh_list_lock)
915{
916 spin_unlock_bh(&nr_neigh_list_lock);
917}
918
919static int nr_neigh_show(struct seq_file *seq, void *v)
920{
921 char buf[11];
922 int i;
923
924 if (v == SEQ_START_TOKEN)
925 seq_puts(seq, "addr callsign dev qual lock count failed digipeaters\n");
926 else {
927 struct nr_neigh *nr_neigh;
928
929 nr_neigh = hlist_entry(v, struct nr_neigh, neigh_node);
930 seq_printf(seq, "%05d %-9s %-4s %3d %d %3d %3d",
931 nr_neigh->number,
932 ax2asc(buf, &nr_neigh->callsign),
933 nr_neigh->dev ? nr_neigh->dev->name : "???",
934 nr_neigh->quality,
935 nr_neigh->locked,
936 nr_neigh->count,
937 nr_neigh->failed);
938
939 if (nr_neigh->digipeat != NULL) {
940 for (i = 0; i < nr_neigh->digipeat->ndigi; i++)
941 seq_printf(seq, " %s",
942 ax2asc(buf, &nr_neigh->digipeat->calls[i]));
943 }
944
945 seq_puts(seq, "\n");
946 }
947 return 0;
948}
949
950const struct seq_operations nr_neigh_seqops = {
951 .start = nr_neigh_start,
952 .next = nr_neigh_next,
953 .stop = nr_neigh_stop,
954 .show = nr_neigh_show,
955};
956#endif
957
958/*
959 * Free all memory associated with the nodes and routes lists.
960 */
961void nr_rt_free(void)
962{
963 struct nr_neigh *s = NULL;
964 struct nr_node *t = NULL;
965 struct hlist_node *nodet;
966
967 spin_lock_bh(&nr_neigh_list_lock);
968 spin_lock_bh(&nr_node_list_lock);
969 nr_node_for_each_safe(t, nodet, &nr_node_list) {
970 nr_node_lock(t);
971 nr_remove_node_locked(t);
972 nr_node_unlock(t);
973 }
974 nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
975 while(s->count) {
976 s->count--;
977 nr_neigh_put(s);
978 }
979 nr_remove_neigh_locked(s);
980 }
981 spin_unlock_bh(&nr_node_list_lock);
982 spin_unlock_bh(&nr_neigh_list_lock);
983}