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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 = READ_ONCE(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 strscpy(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 strscpy(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 void nr_remove_node_locked(struct nr_node *nr_node)
289{
290 lockdep_assert_held(&nr_node_list_lock);
291
292 hlist_del_init(&nr_node->node_node);
293 nr_node_put(nr_node);
294}
295
296static inline void __nr_remove_neigh(struct nr_neigh *nr_neigh)
297{
298 hlist_del_init(&nr_neigh->neigh_node);
299 nr_neigh_put(nr_neigh);
300}
301
302#define nr_remove_neigh_locked(__neigh) \
303 __nr_remove_neigh(__neigh)
304
305static void nr_remove_neigh(struct nr_neigh *nr_neigh)
306{
307 spin_lock_bh(&nr_neigh_list_lock);
308 __nr_remove_neigh(nr_neigh);
309 spin_unlock_bh(&nr_neigh_list_lock);
310}
311
312/*
313 * "Delete" a node. Strictly speaking remove a route to a node. The node
314 * is only deleted if no routes are left to it.
315 */
316static int nr_del_node(ax25_address *callsign, ax25_address *neighbour, struct net_device *dev)
317{
318 struct nr_node *nr_node;
319 struct nr_neigh *nr_neigh;
320 int i;
321
322 nr_node = nr_node_get(callsign);
323
324 if (nr_node == NULL)
325 return -EINVAL;
326
327 nr_neigh = nr_neigh_get_dev(neighbour, dev);
328
329 if (nr_neigh == NULL) {
330 nr_node_put(nr_node);
331 return -EINVAL;
332 }
333
334 spin_lock_bh(&nr_node_list_lock);
335 nr_node_lock(nr_node);
336 for (i = 0; i < nr_node->count; i++) {
337 if (nr_node->routes[i].neighbour == nr_neigh) {
338 nr_neigh->count--;
339 nr_neigh_put(nr_neigh);
340
341 if (nr_neigh->count == 0 && !nr_neigh->locked)
342 nr_remove_neigh(nr_neigh);
343 nr_neigh_put(nr_neigh);
344
345 nr_node->count--;
346
347 if (nr_node->count == 0) {
348 nr_remove_node_locked(nr_node);
349 } else {
350 switch (i) {
351 case 0:
352 nr_node->routes[0] = nr_node->routes[1];
353 fallthrough;
354 case 1:
355 nr_node->routes[1] = nr_node->routes[2];
356 fallthrough;
357 case 2:
358 break;
359 }
360 nr_node_put(nr_node);
361 }
362 nr_node_unlock(nr_node);
363 spin_unlock_bh(&nr_node_list_lock);
364
365 return 0;
366 }
367 }
368 nr_neigh_put(nr_neigh);
369 nr_node_unlock(nr_node);
370 spin_unlock_bh(&nr_node_list_lock);
371 nr_node_put(nr_node);
372
373 return -EINVAL;
374}
375
376/*
377 * Lock a neighbour with a quality.
378 */
379static int __must_check nr_add_neigh(ax25_address *callsign,
380 ax25_digi *ax25_digi, struct net_device *dev, unsigned int quality)
381{
382 struct nr_neigh *nr_neigh;
383
384 nr_neigh = nr_neigh_get_dev(callsign, dev);
385 if (nr_neigh) {
386 nr_neigh->quality = quality;
387 nr_neigh->locked = 1;
388 nr_neigh_put(nr_neigh);
389 return 0;
390 }
391
392 if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL)
393 return -ENOMEM;
394
395 nr_neigh->callsign = *callsign;
396 nr_neigh->digipeat = NULL;
397 nr_neigh->ax25 = NULL;
398 nr_neigh->dev = dev;
399 nr_neigh->quality = quality;
400 nr_neigh->locked = 1;
401 nr_neigh->count = 0;
402 nr_neigh->number = nr_neigh_no++;
403 nr_neigh->failed = 0;
404 refcount_set(&nr_neigh->refcount, 1);
405
406 if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
407 nr_neigh->digipeat = kmemdup(ax25_digi, sizeof(*ax25_digi),
408 GFP_KERNEL);
409 if (nr_neigh->digipeat == NULL) {
410 kfree(nr_neigh);
411 return -ENOMEM;
412 }
413 }
414
415 spin_lock_bh(&nr_neigh_list_lock);
416 hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
417 /* refcount is initialized at 1 */
418 spin_unlock_bh(&nr_neigh_list_lock);
419
420 return 0;
421}
422
423/*
424 * "Delete" a neighbour. The neighbour is only removed if the number
425 * of nodes that may use it is zero.
426 */
427static int nr_del_neigh(ax25_address *callsign, struct net_device *dev, unsigned int quality)
428{
429 struct nr_neigh *nr_neigh;
430
431 nr_neigh = nr_neigh_get_dev(callsign, dev);
432
433 if (nr_neigh == NULL) return -EINVAL;
434
435 nr_neigh->quality = quality;
436 nr_neigh->locked = 0;
437
438 if (nr_neigh->count == 0)
439 nr_remove_neigh(nr_neigh);
440 nr_neigh_put(nr_neigh);
441
442 return 0;
443}
444
445/*
446 * Decrement the obsolescence count by one. If a route is reduced to a
447 * count of zero, remove it. Also remove any unlocked neighbours with
448 * zero nodes routing via it.
449 */
450static int nr_dec_obs(void)
451{
452 struct nr_neigh *nr_neigh;
453 struct nr_node *s;
454 struct hlist_node *nodet;
455 int i;
456
457 spin_lock_bh(&nr_node_list_lock);
458 nr_node_for_each_safe(s, nodet, &nr_node_list) {
459 nr_node_lock(s);
460 for (i = 0; i < s->count; i++) {
461 switch (s->routes[i].obs_count) {
462 case 0: /* A locked entry */
463 break;
464
465 case 1: /* From 1 -> 0 */
466 nr_neigh = s->routes[i].neighbour;
467
468 nr_neigh->count--;
469 nr_neigh_put(nr_neigh);
470
471 if (nr_neigh->count == 0 && !nr_neigh->locked)
472 nr_remove_neigh(nr_neigh);
473
474 s->count--;
475
476 switch (i) {
477 case 0:
478 s->routes[0] = s->routes[1];
479 fallthrough;
480 case 1:
481 s->routes[1] = s->routes[2];
482 break;
483 case 2:
484 break;
485 }
486 break;
487
488 default:
489 s->routes[i].obs_count--;
490 break;
491
492 }
493 }
494
495 if (s->count <= 0)
496 nr_remove_node_locked(s);
497 nr_node_unlock(s);
498 }
499 spin_unlock_bh(&nr_node_list_lock);
500
501 return 0;
502}
503
504/*
505 * A device has been removed. Remove its routes and neighbours.
506 */
507void nr_rt_device_down(struct net_device *dev)
508{
509 struct nr_neigh *s;
510 struct hlist_node *nodet, *node2t;
511 struct nr_node *t;
512 int i;
513
514 spin_lock_bh(&nr_neigh_list_lock);
515 nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
516 if (s->dev == dev) {
517 spin_lock_bh(&nr_node_list_lock);
518 nr_node_for_each_safe(t, node2t, &nr_node_list) {
519 nr_node_lock(t);
520 for (i = 0; i < t->count; i++) {
521 if (t->routes[i].neighbour == s) {
522 t->count--;
523
524 switch (i) {
525 case 0:
526 t->routes[0] = t->routes[1];
527 fallthrough;
528 case 1:
529 t->routes[1] = t->routes[2];
530 break;
531 case 2:
532 break;
533 }
534 }
535 }
536
537 if (t->count <= 0)
538 nr_remove_node_locked(t);
539 nr_node_unlock(t);
540 }
541 spin_unlock_bh(&nr_node_list_lock);
542
543 nr_remove_neigh_locked(s);
544 }
545 }
546 spin_unlock_bh(&nr_neigh_list_lock);
547}
548
549/*
550 * Check that the device given is a valid AX.25 interface that is "up".
551 * Or a valid ethernet interface with an AX.25 callsign binding.
552 */
553static struct net_device *nr_ax25_dev_get(char *devname)
554{
555 struct net_device *dev;
556
557 if ((dev = dev_get_by_name(&init_net, devname)) == NULL)
558 return NULL;
559
560 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_AX25)
561 return dev;
562
563 dev_put(dev);
564 return NULL;
565}
566
567/*
568 * Find the first active NET/ROM device, usually "nr0".
569 */
570struct net_device *nr_dev_first(void)
571{
572 struct net_device *dev, *first = NULL;
573
574 rcu_read_lock();
575 for_each_netdev_rcu(&init_net, dev) {
576 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM)
577 if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
578 first = dev;
579 }
580 dev_hold(first);
581 rcu_read_unlock();
582
583 return first;
584}
585
586/*
587 * Find the NET/ROM device for the given callsign.
588 */
589struct net_device *nr_dev_get(ax25_address *addr)
590{
591 struct net_device *dev;
592
593 rcu_read_lock();
594 for_each_netdev_rcu(&init_net, dev) {
595 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM &&
596 ax25cmp(addr, (const ax25_address *)dev->dev_addr) == 0) {
597 dev_hold(dev);
598 goto out;
599 }
600 }
601 dev = NULL;
602out:
603 rcu_read_unlock();
604 return dev;
605}
606
607static ax25_digi *nr_call_to_digi(ax25_digi *digi, int ndigis,
608 ax25_address *digipeaters)
609{
610 int i;
611
612 if (ndigis == 0)
613 return NULL;
614
615 for (i = 0; i < ndigis; i++) {
616 digi->calls[i] = digipeaters[i];
617 digi->repeated[i] = 0;
618 }
619
620 digi->ndigi = ndigis;
621 digi->lastrepeat = -1;
622
623 return digi;
624}
625
626/*
627 * Handle the ioctls that control the routing functions.
628 */
629int nr_rt_ioctl(unsigned int cmd, void __user *arg)
630{
631 struct nr_route_struct nr_route;
632 struct net_device *dev;
633 ax25_digi digi;
634 int ret;
635
636 switch (cmd) {
637 case SIOCADDRT:
638 if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
639 return -EFAULT;
640 if (nr_route.ndigis > AX25_MAX_DIGIS)
641 return -EINVAL;
642 if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
643 return -EINVAL;
644 switch (nr_route.type) {
645 case NETROM_NODE:
646 if (strnlen(nr_route.mnemonic, 7) == 7) {
647 ret = -EINVAL;
648 break;
649 }
650
651 ret = nr_add_node(&nr_route.callsign,
652 nr_route.mnemonic,
653 &nr_route.neighbour,
654 nr_call_to_digi(&digi, nr_route.ndigis,
655 nr_route.digipeaters),
656 dev, nr_route.quality,
657 nr_route.obs_count);
658 break;
659 case NETROM_NEIGH:
660 ret = nr_add_neigh(&nr_route.callsign,
661 nr_call_to_digi(&digi, nr_route.ndigis,
662 nr_route.digipeaters),
663 dev, nr_route.quality);
664 break;
665 default:
666 ret = -EINVAL;
667 }
668 dev_put(dev);
669 return ret;
670
671 case SIOCDELRT:
672 if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
673 return -EFAULT;
674 if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
675 return -EINVAL;
676 switch (nr_route.type) {
677 case NETROM_NODE:
678 ret = nr_del_node(&nr_route.callsign,
679 &nr_route.neighbour, dev);
680 break;
681 case NETROM_NEIGH:
682 ret = nr_del_neigh(&nr_route.callsign,
683 dev, nr_route.quality);
684 break;
685 default:
686 ret = -EINVAL;
687 }
688 dev_put(dev);
689 return ret;
690
691 case SIOCNRDECOBS:
692 return nr_dec_obs();
693
694 default:
695 return -EINVAL;
696 }
697
698 return 0;
699}
700
701/*
702 * A level 2 link has timed out, therefore it appears to be a poor link,
703 * then don't use that neighbour until it is reset.
704 */
705void nr_link_failed(ax25_cb *ax25, int reason)
706{
707 struct nr_neigh *s, *nr_neigh = NULL;
708 struct nr_node *nr_node = NULL;
709
710 spin_lock_bh(&nr_neigh_list_lock);
711 nr_neigh_for_each(s, &nr_neigh_list) {
712 if (s->ax25 == ax25) {
713 nr_neigh_hold(s);
714 nr_neigh = s;
715 break;
716 }
717 }
718 spin_unlock_bh(&nr_neigh_list_lock);
719
720 if (nr_neigh == NULL)
721 return;
722
723 nr_neigh->ax25 = NULL;
724 ax25_cb_put(ax25);
725
726 if (++nr_neigh->failed < READ_ONCE(sysctl_netrom_link_fails_count)) {
727 nr_neigh_put(nr_neigh);
728 return;
729 }
730 spin_lock_bh(&nr_node_list_lock);
731 nr_node_for_each(nr_node, &nr_node_list) {
732 nr_node_lock(nr_node);
733 if (nr_node->which < nr_node->count &&
734 nr_node->routes[nr_node->which].neighbour == nr_neigh)
735 nr_node->which++;
736 nr_node_unlock(nr_node);
737 }
738 spin_unlock_bh(&nr_node_list_lock);
739 nr_neigh_put(nr_neigh);
740}
741
742/*
743 * Route a frame to an appropriate AX.25 connection. A NULL ax25_cb
744 * indicates an internally generated frame.
745 */
746int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
747{
748 ax25_address *nr_src, *nr_dest;
749 struct nr_neigh *nr_neigh;
750 struct nr_node *nr_node;
751 struct net_device *dev;
752 unsigned char *dptr;
753 ax25_cb *ax25s;
754 int ret;
755 struct sk_buff *skbn;
756
757 /*
758 * Reject malformed packets early. Check that it contains at least 2
759 * addresses and 1 byte more for Time-To-Live
760 */
761 if (skb->len < 2 * sizeof(ax25_address) + 1)
762 return 0;
763
764 nr_src = (ax25_address *)(skb->data + 0);
765 nr_dest = (ax25_address *)(skb->data + 7);
766
767 if (ax25 != NULL) {
768 ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
769 ax25->ax25_dev->dev, 0,
770 READ_ONCE(sysctl_netrom_obsolescence_count_initialiser));
771 if (ret)
772 return ret;
773 }
774
775 if ((dev = nr_dev_get(nr_dest)) != NULL) { /* Its for me */
776 if (ax25 == NULL) /* Its from me */
777 ret = nr_loopback_queue(skb);
778 else
779 ret = nr_rx_frame(skb, dev);
780 dev_put(dev);
781 return ret;
782 }
783
784 if (!READ_ONCE(sysctl_netrom_routing_control) && ax25 != NULL)
785 return 0;
786
787 /* Its Time-To-Live has expired */
788 if (skb->data[14] == 1) {
789 return 0;
790 }
791
792 nr_node = nr_node_get(nr_dest);
793 if (nr_node == NULL)
794 return 0;
795 nr_node_lock(nr_node);
796
797 if (nr_node->which >= nr_node->count) {
798 nr_node_unlock(nr_node);
799 nr_node_put(nr_node);
800 return 0;
801 }
802
803 nr_neigh = nr_node->routes[nr_node->which].neighbour;
804
805 if ((dev = nr_dev_first()) == NULL) {
806 nr_node_unlock(nr_node);
807 nr_node_put(nr_node);
808 return 0;
809 }
810
811 /* We are going to change the netrom headers so we should get our
812 own skb, we also did not know until now how much header space
813 we had to reserve... - RXQ */
814 if ((skbn=skb_copy_expand(skb, dev->hard_header_len, 0, GFP_ATOMIC)) == NULL) {
815 nr_node_unlock(nr_node);
816 nr_node_put(nr_node);
817 dev_put(dev);
818 return 0;
819 }
820 kfree_skb(skb);
821 skb=skbn;
822 skb->data[14]--;
823
824 dptr = skb_push(skb, 1);
825 *dptr = AX25_P_NETROM;
826
827 ax25s = nr_neigh->ax25;
828 nr_neigh->ax25 = ax25_send_frame(skb, 256,
829 (const ax25_address *)dev->dev_addr,
830 &nr_neigh->callsign,
831 nr_neigh->digipeat, nr_neigh->dev);
832 if (ax25s)
833 ax25_cb_put(ax25s);
834
835 dev_put(dev);
836 ret = (nr_neigh->ax25 != NULL);
837 nr_node_unlock(nr_node);
838 nr_node_put(nr_node);
839
840 return ret;
841}
842
843#ifdef CONFIG_PROC_FS
844
845static void *nr_node_start(struct seq_file *seq, loff_t *pos)
846 __acquires(&nr_node_list_lock)
847{
848 spin_lock_bh(&nr_node_list_lock);
849 return seq_hlist_start_head(&nr_node_list, *pos);
850}
851
852static void *nr_node_next(struct seq_file *seq, void *v, loff_t *pos)
853{
854 return seq_hlist_next(v, &nr_node_list, pos);
855}
856
857static void nr_node_stop(struct seq_file *seq, void *v)
858 __releases(&nr_node_list_lock)
859{
860 spin_unlock_bh(&nr_node_list_lock);
861}
862
863static int nr_node_show(struct seq_file *seq, void *v)
864{
865 char buf[11];
866 int i;
867
868 if (v == SEQ_START_TOKEN)
869 seq_puts(seq,
870 "callsign mnemonic w n qual obs neigh qual obs neigh qual obs neigh\n");
871 else {
872 struct nr_node *nr_node = hlist_entry(v, struct nr_node,
873 node_node);
874
875 nr_node_lock(nr_node);
876 seq_printf(seq, "%-9s %-7s %d %d",
877 ax2asc(buf, &nr_node->callsign),
878 (nr_node->mnemonic[0] == '\0') ? "*" : nr_node->mnemonic,
879 nr_node->which + 1,
880 nr_node->count);
881
882 for (i = 0; i < nr_node->count; i++) {
883 seq_printf(seq, " %3d %d %05d",
884 nr_node->routes[i].quality,
885 nr_node->routes[i].obs_count,
886 nr_node->routes[i].neighbour->number);
887 }
888 nr_node_unlock(nr_node);
889
890 seq_puts(seq, "\n");
891 }
892 return 0;
893}
894
895const struct seq_operations nr_node_seqops = {
896 .start = nr_node_start,
897 .next = nr_node_next,
898 .stop = nr_node_stop,
899 .show = nr_node_show,
900};
901
902static void *nr_neigh_start(struct seq_file *seq, loff_t *pos)
903 __acquires(&nr_neigh_list_lock)
904{
905 spin_lock_bh(&nr_neigh_list_lock);
906 return seq_hlist_start_head(&nr_neigh_list, *pos);
907}
908
909static void *nr_neigh_next(struct seq_file *seq, void *v, loff_t *pos)
910{
911 return seq_hlist_next(v, &nr_neigh_list, pos);
912}
913
914static void nr_neigh_stop(struct seq_file *seq, void *v)
915 __releases(&nr_neigh_list_lock)
916{
917 spin_unlock_bh(&nr_neigh_list_lock);
918}
919
920static int nr_neigh_show(struct seq_file *seq, void *v)
921{
922 char buf[11];
923 int i;
924
925 if (v == SEQ_START_TOKEN)
926 seq_puts(seq, "addr callsign dev qual lock count failed digipeaters\n");
927 else {
928 struct nr_neigh *nr_neigh;
929
930 nr_neigh = hlist_entry(v, struct nr_neigh, neigh_node);
931 seq_printf(seq, "%05d %-9s %-4s %3d %d %3d %3d",
932 nr_neigh->number,
933 ax2asc(buf, &nr_neigh->callsign),
934 nr_neigh->dev ? nr_neigh->dev->name : "???",
935 nr_neigh->quality,
936 nr_neigh->locked,
937 nr_neigh->count,
938 nr_neigh->failed);
939
940 if (nr_neigh->digipeat != NULL) {
941 for (i = 0; i < nr_neigh->digipeat->ndigi; i++)
942 seq_printf(seq, " %s",
943 ax2asc(buf, &nr_neigh->digipeat->calls[i]));
944 }
945
946 seq_puts(seq, "\n");
947 }
948 return 0;
949}
950
951const struct seq_operations nr_neigh_seqops = {
952 .start = nr_neigh_start,
953 .next = nr_neigh_next,
954 .stop = nr_neigh_stop,
955 .show = nr_neigh_show,
956};
957#endif
958
959/*
960 * Free all memory associated with the nodes and routes lists.
961 */
962void nr_rt_free(void)
963{
964 struct nr_neigh *s = NULL;
965 struct nr_node *t = NULL;
966 struct hlist_node *nodet;
967
968 spin_lock_bh(&nr_neigh_list_lock);
969 spin_lock_bh(&nr_node_list_lock);
970 nr_node_for_each_safe(t, nodet, &nr_node_list) {
971 nr_node_lock(t);
972 nr_remove_node_locked(t);
973 nr_node_unlock(t);
974 }
975 nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
976 while(s->count) {
977 s->count--;
978 nr_neigh_put(s);
979 }
980 nr_remove_neigh_locked(s);
981 }
982 spin_unlock_bh(&nr_node_list_lock);
983 spin_unlock_bh(&nr_neigh_list_lock);
984}