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
37 static unsigned int nr_neigh_no = 1;
38
39 static HLIST_HEAD(nr_node_list);
40 static DEFINE_SPINLOCK(nr_node_list_lock);
41 static HLIST_HEAD(nr_neigh_list);
42 static DEFINE_SPINLOCK(nr_neigh_list_lock);
43
nr_node_get(ax25_address * callsign)44 static 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
nr_neigh_get_dev(ax25_address * callsign,struct net_device * dev)60 static 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
78 static void nr_remove_neigh(struct nr_neigh *);
79
80 /* re-sort the routes in quality order. */
re_sort_routes(struct nr_node * nr_node,int x,int y)81 static 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 */
nr_add_node(ax25_address * nr,const char * mnemonic,ax25_address * ax25,ax25_digi * ax25_digi,struct net_device * dev,int quality,int obs_count)97 static 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 strcpy(nr_node->mnemonic, mnemonic);
193
194 nr_node->which = 0;
195 nr_node->count = 1;
196 refcount_set(&nr_node->refcount, 1);
197 spin_lock_init(&nr_node->node_lock);
198
199 nr_node->routes[0].quality = quality;
200 nr_node->routes[0].obs_count = obs_count;
201 nr_node->routes[0].neighbour = nr_neigh;
202
203 nr_neigh_hold(nr_neigh);
204 nr_neigh->count++;
205
206 spin_lock_bh(&nr_node_list_lock);
207 hlist_add_head(&nr_node->node_node, &nr_node_list);
208 /* refcount initialized at 1 */
209 spin_unlock_bh(&nr_node_list_lock);
210
211 nr_neigh_put(nr_neigh);
212 return 0;
213 }
214 nr_node_lock(nr_node);
215
216 if (quality != 0)
217 strcpy(nr_node->mnemonic, mnemonic);
218
219 for (found = 0, i = 0; i < nr_node->count; i++) {
220 if (nr_node->routes[i].neighbour == nr_neigh) {
221 nr_node->routes[i].quality = quality;
222 nr_node->routes[i].obs_count = obs_count;
223 found = 1;
224 break;
225 }
226 }
227
228 if (!found) {
229 /* We have space at the bottom, slot it in */
230 if (nr_node->count < 3) {
231 nr_node->routes[2] = nr_node->routes[1];
232 nr_node->routes[1] = nr_node->routes[0];
233
234 nr_node->routes[0].quality = quality;
235 nr_node->routes[0].obs_count = obs_count;
236 nr_node->routes[0].neighbour = nr_neigh;
237
238 nr_node->which++;
239 nr_node->count++;
240 nr_neigh_hold(nr_neigh);
241 nr_neigh->count++;
242 } else {
243 /* It must be better than the worst */
244 if (quality > nr_node->routes[2].quality) {
245 nr_node->routes[2].neighbour->count--;
246 nr_neigh_put(nr_node->routes[2].neighbour);
247
248 if (nr_node->routes[2].neighbour->count == 0 && !nr_node->routes[2].neighbour->locked)
249 nr_remove_neigh(nr_node->routes[2].neighbour);
250
251 nr_node->routes[2].quality = quality;
252 nr_node->routes[2].obs_count = obs_count;
253 nr_node->routes[2].neighbour = nr_neigh;
254
255 nr_neigh_hold(nr_neigh);
256 nr_neigh->count++;
257 }
258 }
259 }
260
261 /* Now re-sort the routes in quality order */
262 switch (nr_node->count) {
263 case 3:
264 re_sort_routes(nr_node, 0, 1);
265 re_sort_routes(nr_node, 1, 2);
266 fallthrough;
267 case 2:
268 re_sort_routes(nr_node, 0, 1);
269 break;
270 case 1:
271 break;
272 }
273
274 for (i = 0; i < nr_node->count; i++) {
275 if (nr_node->routes[i].neighbour == nr_neigh) {
276 if (i < nr_node->which)
277 nr_node->which = i;
278 break;
279 }
280 }
281
282 nr_neigh_put(nr_neigh);
283 nr_node_unlock(nr_node);
284 nr_node_put(nr_node);
285 return 0;
286 }
287
nr_remove_node_locked(struct nr_node * nr_node)288 static 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
__nr_remove_neigh(struct nr_neigh * nr_neigh)296 static 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
nr_remove_neigh(struct nr_neigh * nr_neigh)305 static 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 */
nr_del_node(ax25_address * callsign,ax25_address * neighbour,struct net_device * dev)316 static 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 */
nr_add_neigh(ax25_address * callsign,ax25_digi * ax25_digi,struct net_device * dev,unsigned int quality)379 static 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 */
nr_del_neigh(ax25_address * callsign,struct net_device * dev,unsigned int quality)427 static 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 */
nr_dec_obs(void)450 static 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 */
nr_rt_device_down(struct net_device * dev)507 void 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 */
nr_ax25_dev_get(char * devname)553 static 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 */
nr_dev_first(void)570 struct 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 */
nr_dev_get(ax25_address * addr)589 struct 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;
602 out:
603 rcu_read_unlock();
604 return dev;
605 }
606
nr_call_to_digi(ax25_digi * digi,int ndigis,ax25_address * digipeaters)607 static 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 */
nr_rt_ioctl(unsigned int cmd,void __user * arg)629 int 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 */
nr_link_failed(ax25_cb * ax25,int reason)705 void 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 */
nr_route_frame(struct sk_buff * skb,ax25_cb * ax25)746 int 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 nr_src = (ax25_address *)(skb->data + 0);
759 nr_dest = (ax25_address *)(skb->data + 7);
760
761 if (ax25 != NULL) {
762 ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
763 ax25->ax25_dev->dev, 0,
764 READ_ONCE(sysctl_netrom_obsolescence_count_initialiser));
765 if (ret)
766 return ret;
767 }
768
769 if ((dev = nr_dev_get(nr_dest)) != NULL) { /* Its for me */
770 if (ax25 == NULL) /* Its from me */
771 ret = nr_loopback_queue(skb);
772 else
773 ret = nr_rx_frame(skb, dev);
774 dev_put(dev);
775 return ret;
776 }
777
778 if (!READ_ONCE(sysctl_netrom_routing_control) && ax25 != NULL)
779 return 0;
780
781 /* Its Time-To-Live has expired */
782 if (skb->data[14] == 1) {
783 return 0;
784 }
785
786 nr_node = nr_node_get(nr_dest);
787 if (nr_node == NULL)
788 return 0;
789 nr_node_lock(nr_node);
790
791 if (nr_node->which >= nr_node->count) {
792 nr_node_unlock(nr_node);
793 nr_node_put(nr_node);
794 return 0;
795 }
796
797 nr_neigh = nr_node->routes[nr_node->which].neighbour;
798
799 if ((dev = nr_dev_first()) == NULL) {
800 nr_node_unlock(nr_node);
801 nr_node_put(nr_node);
802 return 0;
803 }
804
805 /* We are going to change the netrom headers so we should get our
806 own skb, we also did not know until now how much header space
807 we had to reserve... - RXQ */
808 if ((skbn=skb_copy_expand(skb, dev->hard_header_len, 0, GFP_ATOMIC)) == NULL) {
809 nr_node_unlock(nr_node);
810 nr_node_put(nr_node);
811 dev_put(dev);
812 return 0;
813 }
814 kfree_skb(skb);
815 skb=skbn;
816 skb->data[14]--;
817
818 dptr = skb_push(skb, 1);
819 *dptr = AX25_P_NETROM;
820
821 ax25s = nr_neigh->ax25;
822 nr_neigh->ax25 = ax25_send_frame(skb, 256,
823 (const ax25_address *)dev->dev_addr,
824 &nr_neigh->callsign,
825 nr_neigh->digipeat, nr_neigh->dev);
826 if (ax25s)
827 ax25_cb_put(ax25s);
828
829 dev_put(dev);
830 ret = (nr_neigh->ax25 != NULL);
831 nr_node_unlock(nr_node);
832 nr_node_put(nr_node);
833
834 return ret;
835 }
836
837 #ifdef CONFIG_PROC_FS
838
nr_node_start(struct seq_file * seq,loff_t * pos)839 static void *nr_node_start(struct seq_file *seq, loff_t *pos)
840 __acquires(&nr_node_list_lock)
841 {
842 spin_lock_bh(&nr_node_list_lock);
843 return seq_hlist_start_head(&nr_node_list, *pos);
844 }
845
nr_node_next(struct seq_file * seq,void * v,loff_t * pos)846 static 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
nr_node_stop(struct seq_file * seq,void * v)851 static void nr_node_stop(struct seq_file *seq, void *v)
852 __releases(&nr_node_list_lock)
853 {
854 spin_unlock_bh(&nr_node_list_lock);
855 }
856
nr_node_show(struct seq_file * seq,void * v)857 static int nr_node_show(struct seq_file *seq, void *v)
858 {
859 char buf[11];
860 int i;
861
862 if (v == SEQ_START_TOKEN)
863 seq_puts(seq,
864 "callsign mnemonic w n qual obs neigh qual obs neigh qual obs neigh\n");
865 else {
866 struct nr_node *nr_node = hlist_entry(v, struct nr_node,
867 node_node);
868
869 nr_node_lock(nr_node);
870 seq_printf(seq, "%-9s %-7s %d %d",
871 ax2asc(buf, &nr_node->callsign),
872 (nr_node->mnemonic[0] == '\0') ? "*" : nr_node->mnemonic,
873 nr_node->which + 1,
874 nr_node->count);
875
876 for (i = 0; i < nr_node->count; i++) {
877 seq_printf(seq, " %3d %d %05d",
878 nr_node->routes[i].quality,
879 nr_node->routes[i].obs_count,
880 nr_node->routes[i].neighbour->number);
881 }
882 nr_node_unlock(nr_node);
883
884 seq_puts(seq, "\n");
885 }
886 return 0;
887 }
888
889 const struct seq_operations nr_node_seqops = {
890 .start = nr_node_start,
891 .next = nr_node_next,
892 .stop = nr_node_stop,
893 .show = nr_node_show,
894 };
895
nr_neigh_start(struct seq_file * seq,loff_t * pos)896 static void *nr_neigh_start(struct seq_file *seq, loff_t *pos)
897 __acquires(&nr_neigh_list_lock)
898 {
899 spin_lock_bh(&nr_neigh_list_lock);
900 return seq_hlist_start_head(&nr_neigh_list, *pos);
901 }
902
nr_neigh_next(struct seq_file * seq,void * v,loff_t * pos)903 static void *nr_neigh_next(struct seq_file *seq, void *v, loff_t *pos)
904 {
905 return seq_hlist_next(v, &nr_neigh_list, pos);
906 }
907
nr_neigh_stop(struct seq_file * seq,void * v)908 static void nr_neigh_stop(struct seq_file *seq, void *v)
909 __releases(&nr_neigh_list_lock)
910 {
911 spin_unlock_bh(&nr_neigh_list_lock);
912 }
913
nr_neigh_show(struct seq_file * seq,void * v)914 static int nr_neigh_show(struct seq_file *seq, void *v)
915 {
916 char buf[11];
917 int i;
918
919 if (v == SEQ_START_TOKEN)
920 seq_puts(seq, "addr callsign dev qual lock count failed digipeaters\n");
921 else {
922 struct nr_neigh *nr_neigh;
923
924 nr_neigh = hlist_entry(v, struct nr_neigh, neigh_node);
925 seq_printf(seq, "%05d %-9s %-4s %3d %d %3d %3d",
926 nr_neigh->number,
927 ax2asc(buf, &nr_neigh->callsign),
928 nr_neigh->dev ? nr_neigh->dev->name : "???",
929 nr_neigh->quality,
930 nr_neigh->locked,
931 nr_neigh->count,
932 nr_neigh->failed);
933
934 if (nr_neigh->digipeat != NULL) {
935 for (i = 0; i < nr_neigh->digipeat->ndigi; i++)
936 seq_printf(seq, " %s",
937 ax2asc(buf, &nr_neigh->digipeat->calls[i]));
938 }
939
940 seq_puts(seq, "\n");
941 }
942 return 0;
943 }
944
945 const struct seq_operations nr_neigh_seqops = {
946 .start = nr_neigh_start,
947 .next = nr_neigh_next,
948 .stop = nr_neigh_stop,
949 .show = nr_neigh_show,
950 };
951 #endif
952
953 /*
954 * Free all memory associated with the nodes and routes lists.
955 */
nr_rt_free(void)956 void nr_rt_free(void)
957 {
958 struct nr_neigh *s = NULL;
959 struct nr_node *t = NULL;
960 struct hlist_node *nodet;
961
962 spin_lock_bh(&nr_neigh_list_lock);
963 spin_lock_bh(&nr_node_list_lock);
964 nr_node_for_each_safe(t, nodet, &nr_node_list) {
965 nr_node_lock(t);
966 nr_remove_node_locked(t);
967 nr_node_unlock(t);
968 }
969 nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
970 while(s->count) {
971 s->count--;
972 nr_neigh_put(s);
973 }
974 nr_remove_neigh_locked(s);
975 }
976 spin_unlock_bh(&nr_node_list_lock);
977 spin_unlock_bh(&nr_neigh_list_lock);
978 }
979