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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 return 0;
212 }
213 nr_node_lock(nr_node);
214
215 if (quality != 0)
216 strcpy(nr_node->mnemonic, mnemonic);
217
218 for (found = 0, i = 0; i < nr_node->count; i++) {
219 if (nr_node->routes[i].neighbour == nr_neigh) {
220 nr_node->routes[i].quality = quality;
221 nr_node->routes[i].obs_count = obs_count;
222 found = 1;
223 break;
224 }
225 }
226
227 if (!found) {
228 /* We have space at the bottom, slot it in */
229 if (nr_node->count < 3) {
230 nr_node->routes[2] = nr_node->routes[1];
231 nr_node->routes[1] = nr_node->routes[0];
232
233 nr_node->routes[0].quality = quality;
234 nr_node->routes[0].obs_count = obs_count;
235 nr_node->routes[0].neighbour = nr_neigh;
236
237 nr_node->which++;
238 nr_node->count++;
239 nr_neigh_hold(nr_neigh);
240 nr_neigh->count++;
241 } else {
242 /* It must be better than the worst */
243 if (quality > nr_node->routes[2].quality) {
244 nr_node->routes[2].neighbour->count--;
245 nr_neigh_put(nr_node->routes[2].neighbour);
246
247 if (nr_node->routes[2].neighbour->count == 0 && !nr_node->routes[2].neighbour->locked)
248 nr_remove_neigh(nr_node->routes[2].neighbour);
249
250 nr_node->routes[2].quality = quality;
251 nr_node->routes[2].obs_count = obs_count;
252 nr_node->routes[2].neighbour = nr_neigh;
253
254 nr_neigh_hold(nr_neigh);
255 nr_neigh->count++;
256 }
257 }
258 }
259
260 /* Now re-sort the routes in quality order */
261 switch (nr_node->count) {
262 case 3:
263 re_sort_routes(nr_node, 0, 1);
264 re_sort_routes(nr_node, 1, 2);
265 /* fall through */
266 case 2:
267 re_sort_routes(nr_node, 0, 1);
268 case 1:
269 break;
270 }
271
272 for (i = 0; i < nr_node->count; i++) {
273 if (nr_node->routes[i].neighbour == nr_neigh) {
274 if (i < nr_node->which)
275 nr_node->which = i;
276 break;
277 }
278 }
279
280 nr_neigh_put(nr_neigh);
281 nr_node_unlock(nr_node);
282 nr_node_put(nr_node);
283 return 0;
284}
285
286static inline void __nr_remove_node(struct nr_node *nr_node)
287{
288 hlist_del_init(&nr_node->node_node);
289 nr_node_put(nr_node);
290}
291
292#define nr_remove_node_locked(__node) \
293 __nr_remove_node(__node)
294
295static void nr_remove_node(struct nr_node *nr_node)
296{
297 spin_lock_bh(&nr_node_list_lock);
298 __nr_remove_node(nr_node);
299 spin_unlock_bh(&nr_node_list_lock);
300}
301
302static inline void __nr_remove_neigh(struct nr_neigh *nr_neigh)
303{
304 hlist_del_init(&nr_neigh->neigh_node);
305 nr_neigh_put(nr_neigh);
306}
307
308#define nr_remove_neigh_locked(__neigh) \
309 __nr_remove_neigh(__neigh)
310
311static void nr_remove_neigh(struct nr_neigh *nr_neigh)
312{
313 spin_lock_bh(&nr_neigh_list_lock);
314 __nr_remove_neigh(nr_neigh);
315 spin_unlock_bh(&nr_neigh_list_lock);
316}
317
318/*
319 * "Delete" a node. Strictly speaking remove a route to a node. The node
320 * is only deleted if no routes are left to it.
321 */
322static int nr_del_node(ax25_address *callsign, ax25_address *neighbour, struct net_device *dev)
323{
324 struct nr_node *nr_node;
325 struct nr_neigh *nr_neigh;
326 int i;
327
328 nr_node = nr_node_get(callsign);
329
330 if (nr_node == NULL)
331 return -EINVAL;
332
333 nr_neigh = nr_neigh_get_dev(neighbour, dev);
334
335 if (nr_neigh == NULL) {
336 nr_node_put(nr_node);
337 return -EINVAL;
338 }
339
340 nr_node_lock(nr_node);
341 for (i = 0; i < nr_node->count; i++) {
342 if (nr_node->routes[i].neighbour == nr_neigh) {
343 nr_neigh->count--;
344 nr_neigh_put(nr_neigh);
345
346 if (nr_neigh->count == 0 && !nr_neigh->locked)
347 nr_remove_neigh(nr_neigh);
348 nr_neigh_put(nr_neigh);
349
350 nr_node->count--;
351
352 if (nr_node->count == 0) {
353 nr_remove_node(nr_node);
354 } else {
355 switch (i) {
356 case 0:
357 nr_node->routes[0] = nr_node->routes[1];
358 /* fall through */
359 case 1:
360 nr_node->routes[1] = nr_node->routes[2];
361 case 2:
362 break;
363 }
364 nr_node_put(nr_node);
365 }
366 nr_node_unlock(nr_node);
367
368 return 0;
369 }
370 }
371 nr_neigh_put(nr_neigh);
372 nr_node_unlock(nr_node);
373 nr_node_put(nr_node);
374
375 return -EINVAL;
376}
377
378/*
379 * Lock a neighbour with a quality.
380 */
381static int __must_check nr_add_neigh(ax25_address *callsign,
382 ax25_digi *ax25_digi, struct net_device *dev, unsigned int quality)
383{
384 struct nr_neigh *nr_neigh;
385
386 nr_neigh = nr_neigh_get_dev(callsign, dev);
387 if (nr_neigh) {
388 nr_neigh->quality = quality;
389 nr_neigh->locked = 1;
390 nr_neigh_put(nr_neigh);
391 return 0;
392 }
393
394 if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL)
395 return -ENOMEM;
396
397 nr_neigh->callsign = *callsign;
398 nr_neigh->digipeat = NULL;
399 nr_neigh->ax25 = NULL;
400 nr_neigh->dev = dev;
401 nr_neigh->quality = quality;
402 nr_neigh->locked = 1;
403 nr_neigh->count = 0;
404 nr_neigh->number = nr_neigh_no++;
405 nr_neigh->failed = 0;
406 refcount_set(&nr_neigh->refcount, 1);
407
408 if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
409 nr_neigh->digipeat = kmemdup(ax25_digi, sizeof(*ax25_digi),
410 GFP_KERNEL);
411 if (nr_neigh->digipeat == NULL) {
412 kfree(nr_neigh);
413 return -ENOMEM;
414 }
415 }
416
417 spin_lock_bh(&nr_neigh_list_lock);
418 hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
419 /* refcount is initialized at 1 */
420 spin_unlock_bh(&nr_neigh_list_lock);
421
422 return 0;
423}
424
425/*
426 * "Delete" a neighbour. The neighbour is only removed if the number
427 * of nodes that may use it is zero.
428 */
429static int nr_del_neigh(ax25_address *callsign, struct net_device *dev, unsigned int quality)
430{
431 struct nr_neigh *nr_neigh;
432
433 nr_neigh = nr_neigh_get_dev(callsign, dev);
434
435 if (nr_neigh == NULL) return -EINVAL;
436
437 nr_neigh->quality = quality;
438 nr_neigh->locked = 0;
439
440 if (nr_neigh->count == 0)
441 nr_remove_neigh(nr_neigh);
442 nr_neigh_put(nr_neigh);
443
444 return 0;
445}
446
447/*
448 * Decrement the obsolescence count by one. If a route is reduced to a
449 * count of zero, remove it. Also remove any unlocked neighbours with
450 * zero nodes routing via it.
451 */
452static int nr_dec_obs(void)
453{
454 struct nr_neigh *nr_neigh;
455 struct nr_node *s;
456 struct hlist_node *nodet;
457 int i;
458
459 spin_lock_bh(&nr_node_list_lock);
460 nr_node_for_each_safe(s, nodet, &nr_node_list) {
461 nr_node_lock(s);
462 for (i = 0; i < s->count; i++) {
463 switch (s->routes[i].obs_count) {
464 case 0: /* A locked entry */
465 break;
466
467 case 1: /* From 1 -> 0 */
468 nr_neigh = s->routes[i].neighbour;
469
470 nr_neigh->count--;
471 nr_neigh_put(nr_neigh);
472
473 if (nr_neigh->count == 0 && !nr_neigh->locked)
474 nr_remove_neigh(nr_neigh);
475
476 s->count--;
477
478 switch (i) {
479 case 0:
480 s->routes[0] = s->routes[1];
481 /* Fallthrough */
482 case 1:
483 s->routes[1] = s->routes[2];
484 case 2:
485 break;
486 }
487 break;
488
489 default:
490 s->routes[i].obs_count--;
491 break;
492
493 }
494 }
495
496 if (s->count <= 0)
497 nr_remove_node_locked(s);
498 nr_node_unlock(s);
499 }
500 spin_unlock_bh(&nr_node_list_lock);
501
502 return 0;
503}
504
505/*
506 * A device has been removed. Remove its routes and neighbours.
507 */
508void nr_rt_device_down(struct net_device *dev)
509{
510 struct nr_neigh *s;
511 struct hlist_node *nodet, *node2t;
512 struct nr_node *t;
513 int i;
514
515 spin_lock_bh(&nr_neigh_list_lock);
516 nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
517 if (s->dev == dev) {
518 spin_lock_bh(&nr_node_list_lock);
519 nr_node_for_each_safe(t, node2t, &nr_node_list) {
520 nr_node_lock(t);
521 for (i = 0; i < t->count; i++) {
522 if (t->routes[i].neighbour == s) {
523 t->count--;
524
525 switch (i) {
526 case 0:
527 t->routes[0] = t->routes[1];
528 /* fall through */
529 case 1:
530 t->routes[1] = t->routes[2];
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 if (first)
581 dev_hold(first);
582 rcu_read_unlock();
583
584 return first;
585}
586
587/*
588 * Find the NET/ROM device for the given callsign.
589 */
590struct net_device *nr_dev_get(ax25_address *addr)
591{
592 struct net_device *dev;
593
594 rcu_read_lock();
595 for_each_netdev_rcu(&init_net, dev) {
596 if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM &&
597 ax25cmp(addr, (ax25_address *)dev->dev_addr) == 0) {
598 dev_hold(dev);
599 goto out;
600 }
601 }
602 dev = NULL;
603out:
604 rcu_read_unlock();
605 return dev;
606}
607
608static ax25_digi *nr_call_to_digi(ax25_digi *digi, int ndigis,
609 ax25_address *digipeaters)
610{
611 int i;
612
613 if (ndigis == 0)
614 return NULL;
615
616 for (i = 0; i < ndigis; i++) {
617 digi->calls[i] = digipeaters[i];
618 digi->repeated[i] = 0;
619 }
620
621 digi->ndigi = ndigis;
622 digi->lastrepeat = -1;
623
624 return digi;
625}
626
627/*
628 * Handle the ioctls that control the routing functions.
629 */
630int nr_rt_ioctl(unsigned int cmd, void __user *arg)
631{
632 struct nr_route_struct nr_route;
633 struct net_device *dev;
634 ax25_digi digi;
635 int ret;
636
637 switch (cmd) {
638 case SIOCADDRT:
639 if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
640 return -EFAULT;
641 if (nr_route.ndigis > AX25_MAX_DIGIS)
642 return -EINVAL;
643 if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
644 return -EINVAL;
645 switch (nr_route.type) {
646 case NETROM_NODE:
647 if (strnlen(nr_route.mnemonic, 7) == 7) {
648 ret = -EINVAL;
649 break;
650 }
651
652 ret = nr_add_node(&nr_route.callsign,
653 nr_route.mnemonic,
654 &nr_route.neighbour,
655 nr_call_to_digi(&digi, nr_route.ndigis,
656 nr_route.digipeaters),
657 dev, nr_route.quality,
658 nr_route.obs_count);
659 break;
660 case NETROM_NEIGH:
661 ret = nr_add_neigh(&nr_route.callsign,
662 nr_call_to_digi(&digi, nr_route.ndigis,
663 nr_route.digipeaters),
664 dev, nr_route.quality);
665 break;
666 default:
667 ret = -EINVAL;
668 }
669 dev_put(dev);
670 return ret;
671
672 case SIOCDELRT:
673 if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
674 return -EFAULT;
675 if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
676 return -EINVAL;
677 switch (nr_route.type) {
678 case NETROM_NODE:
679 ret = nr_del_node(&nr_route.callsign,
680 &nr_route.neighbour, dev);
681 break;
682 case NETROM_NEIGH:
683 ret = nr_del_neigh(&nr_route.callsign,
684 dev, nr_route.quality);
685 break;
686 default:
687 ret = -EINVAL;
688 }
689 dev_put(dev);
690 return ret;
691
692 case SIOCNRDECOBS:
693 return nr_dec_obs();
694
695 default:
696 return -EINVAL;
697 }
698
699 return 0;
700}
701
702/*
703 * A level 2 link has timed out, therefore it appears to be a poor link,
704 * then don't use that neighbour until it is reset.
705 */
706void nr_link_failed(ax25_cb *ax25, int reason)
707{
708 struct nr_neigh *s, *nr_neigh = NULL;
709 struct nr_node *nr_node = NULL;
710
711 spin_lock_bh(&nr_neigh_list_lock);
712 nr_neigh_for_each(s, &nr_neigh_list) {
713 if (s->ax25 == ax25) {
714 nr_neigh_hold(s);
715 nr_neigh = s;
716 break;
717 }
718 }
719 spin_unlock_bh(&nr_neigh_list_lock);
720
721 if (nr_neigh == NULL)
722 return;
723
724 nr_neigh->ax25 = NULL;
725 ax25_cb_put(ax25);
726
727 if (++nr_neigh->failed < sysctl_netrom_link_fails_count) {
728 nr_neigh_put(nr_neigh);
729 return;
730 }
731 spin_lock_bh(&nr_node_list_lock);
732 nr_node_for_each(nr_node, &nr_node_list) {
733 nr_node_lock(nr_node);
734 if (nr_node->which < nr_node->count &&
735 nr_node->routes[nr_node->which].neighbour == nr_neigh)
736 nr_node->which++;
737 nr_node_unlock(nr_node);
738 }
739 spin_unlock_bh(&nr_node_list_lock);
740 nr_neigh_put(nr_neigh);
741}
742
743/*
744 * Route a frame to an appropriate AX.25 connection. A NULL ax25_cb
745 * indicates an internally generated frame.
746 */
747int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
748{
749 ax25_address *nr_src, *nr_dest;
750 struct nr_neigh *nr_neigh;
751 struct nr_node *nr_node;
752 struct net_device *dev;
753 unsigned char *dptr;
754 ax25_cb *ax25s;
755 int ret;
756 struct sk_buff *skbn;
757
758
759 nr_src = (ax25_address *)(skb->data + 0);
760 nr_dest = (ax25_address *)(skb->data + 7);
761
762 if (ax25 != NULL) {
763 ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
764 ax25->ax25_dev->dev, 0,
765 sysctl_netrom_obsolescence_count_initialiser);
766 if (ret)
767 return ret;
768 }
769
770 if ((dev = nr_dev_get(nr_dest)) != NULL) { /* Its for me */
771 if (ax25 == NULL) /* Its from me */
772 ret = nr_loopback_queue(skb);
773 else
774 ret = nr_rx_frame(skb, dev);
775 dev_put(dev);
776 return ret;
777 }
778
779 if (!sysctl_netrom_routing_control && ax25 != NULL)
780 return 0;
781
782 /* Its Time-To-Live has expired */
783 if (skb->data[14] == 1) {
784 return 0;
785 }
786
787 nr_node = nr_node_get(nr_dest);
788 if (nr_node == NULL)
789 return 0;
790 nr_node_lock(nr_node);
791
792 if (nr_node->which >= nr_node->count) {
793 nr_node_unlock(nr_node);
794 nr_node_put(nr_node);
795 return 0;
796 }
797
798 nr_neigh = nr_node->routes[nr_node->which].neighbour;
799
800 if ((dev = nr_dev_first()) == NULL) {
801 nr_node_unlock(nr_node);
802 nr_node_put(nr_node);
803 return 0;
804 }
805
806 /* We are going to change the netrom headers so we should get our
807 own skb, we also did not know until now how much header space
808 we had to reserve... - RXQ */
809 if ((skbn=skb_copy_expand(skb, dev->hard_header_len, 0, GFP_ATOMIC)) == NULL) {
810 nr_node_unlock(nr_node);
811 nr_node_put(nr_node);
812 dev_put(dev);
813 return 0;
814 }
815 kfree_skb(skb);
816 skb=skbn;
817 skb->data[14]--;
818
819 dptr = skb_push(skb, 1);
820 *dptr = AX25_P_NETROM;
821
822 ax25s = nr_neigh->ax25;
823 nr_neigh->ax25 = ax25_send_frame(skb, 256,
824 (ax25_address *)dev->dev_addr,
825 &nr_neigh->callsign,
826 nr_neigh->digipeat, nr_neigh->dev);
827 if (ax25s)
828 ax25_cb_put(ax25s);
829
830 dev_put(dev);
831 ret = (nr_neigh->ax25 != NULL);
832 nr_node_unlock(nr_node);
833 nr_node_put(nr_node);
834
835 return ret;
836}
837
838#ifdef CONFIG_PROC_FS
839
840static void *nr_node_start(struct seq_file *seq, loff_t *pos)
841{
842 spin_lock_bh(&nr_node_list_lock);
843 return seq_hlist_start_head(&nr_node_list, *pos);
844}
845
846static void *nr_node_next(struct seq_file *seq, void *v, loff_t *pos)
847{
848 return seq_hlist_next(v, &nr_node_list, pos);
849}
850
851static void nr_node_stop(struct seq_file *seq, void *v)
852{
853 spin_unlock_bh(&nr_node_list_lock);
854}
855
856static int nr_node_show(struct seq_file *seq, void *v)
857{
858 char buf[11];
859 int i;
860
861 if (v == SEQ_START_TOKEN)
862 seq_puts(seq,
863 "callsign mnemonic w n qual obs neigh qual obs neigh qual obs neigh\n");
864 else {
865 struct nr_node *nr_node = hlist_entry(v, struct nr_node,
866 node_node);
867
868 nr_node_lock(nr_node);
869 seq_printf(seq, "%-9s %-7s %d %d",
870 ax2asc(buf, &nr_node->callsign),
871 (nr_node->mnemonic[0] == '\0') ? "*" : nr_node->mnemonic,
872 nr_node->which + 1,
873 nr_node->count);
874
875 for (i = 0; i < nr_node->count; i++) {
876 seq_printf(seq, " %3d %d %05d",
877 nr_node->routes[i].quality,
878 nr_node->routes[i].obs_count,
879 nr_node->routes[i].neighbour->number);
880 }
881 nr_node_unlock(nr_node);
882
883 seq_puts(seq, "\n");
884 }
885 return 0;
886}
887
888const struct seq_operations nr_node_seqops = {
889 .start = nr_node_start,
890 .next = nr_node_next,
891 .stop = nr_node_stop,
892 .show = nr_node_show,
893};
894
895static void *nr_neigh_start(struct seq_file *seq, loff_t *pos)
896{
897 spin_lock_bh(&nr_neigh_list_lock);
898 return seq_hlist_start_head(&nr_neigh_list, *pos);
899}
900
901static void *nr_neigh_next(struct seq_file *seq, void *v, loff_t *pos)
902{
903 return seq_hlist_next(v, &nr_neigh_list, pos);
904}
905
906static void nr_neigh_stop(struct seq_file *seq, void *v)
907{
908 spin_unlock_bh(&nr_neigh_list_lock);
909}
910
911static int nr_neigh_show(struct seq_file *seq, void *v)
912{
913 char buf[11];
914 int i;
915
916 if (v == SEQ_START_TOKEN)
917 seq_puts(seq, "addr callsign dev qual lock count failed digipeaters\n");
918 else {
919 struct nr_neigh *nr_neigh;
920
921 nr_neigh = hlist_entry(v, struct nr_neigh, neigh_node);
922 seq_printf(seq, "%05d %-9s %-4s %3d %d %3d %3d",
923 nr_neigh->number,
924 ax2asc(buf, &nr_neigh->callsign),
925 nr_neigh->dev ? nr_neigh->dev->name : "???",
926 nr_neigh->quality,
927 nr_neigh->locked,
928 nr_neigh->count,
929 nr_neigh->failed);
930
931 if (nr_neigh->digipeat != NULL) {
932 for (i = 0; i < nr_neigh->digipeat->ndigi; i++)
933 seq_printf(seq, " %s",
934 ax2asc(buf, &nr_neigh->digipeat->calls[i]));
935 }
936
937 seq_puts(seq, "\n");
938 }
939 return 0;
940}
941
942const struct seq_operations nr_neigh_seqops = {
943 .start = nr_neigh_start,
944 .next = nr_neigh_next,
945 .stop = nr_neigh_stop,
946 .show = nr_neigh_show,
947};
948#endif
949
950/*
951 * Free all memory associated with the nodes and routes lists.
952 */
953void nr_rt_free(void)
954{
955 struct nr_neigh *s = NULL;
956 struct nr_node *t = NULL;
957 struct hlist_node *nodet;
958
959 spin_lock_bh(&nr_neigh_list_lock);
960 spin_lock_bh(&nr_node_list_lock);
961 nr_node_for_each_safe(t, nodet, &nr_node_list) {
962 nr_node_lock(t);
963 nr_remove_node_locked(t);
964 nr_node_unlock(t);
965 }
966 nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
967 while(s->count) {
968 s->count--;
969 nr_neigh_put(s);
970 }
971 nr_remove_neigh_locked(s);
972 }
973 spin_unlock_bh(&nr_node_list_lock);
974 spin_unlock_bh(&nr_neigh_list_lock);
975}
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}