xref: /kernel/linux/linux-5.10/net/netrom/nr_route.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5 * Copyright Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
6 * Copyright Tomi Manninen OH2BNS (oh2bns@sral.fi)
7 */
8#include <linux/errno.h>
9#include <linux/types.h>
10#include <linux/socket.h>
11#include <linux/in.h>
12#include <linux/kernel.h>
13#include <linux/timer.h>
14#include <linux/string.h>
15#include <linux/sockios.h>
16#include <linux/net.h>
17#include <linux/slab.h>
18#include <net/ax25.h>
19#include <linux/inet.h>
20#include <linux/netdevice.h>
21#include <net/arp.h>
22#include <linux/if_arp.h>
23#include <linux/skbuff.h>
24#include <net/sock.h>
25#include <linux/uaccess.h>
26#include <linux/fcntl.h>
27#include <linux/termios.h>	/* For TIOCINQ/OUTQ */
28#include <linux/mm.h>
29#include <linux/interrupt.h>
30#include <linux/notifier.h>
31#include <linux/init.h>
32#include <linux/spinlock.h>
33#include <net/netrom.h>
34#include <linux/seq_file.h>
35#include <linux/export.h>
36
37static unsigned int nr_neigh_no = 1;
38
39static HLIST_HEAD(nr_node_list);
40static DEFINE_SPINLOCK(nr_node_list_lock);
41static HLIST_HEAD(nr_neigh_list);
42static DEFINE_SPINLOCK(nr_neigh_list_lock);
43
44static struct nr_node *nr_node_get(ax25_address *callsign)
45{
46	struct nr_node *found = NULL;
47	struct nr_node *nr_node;
48
49	spin_lock_bh(&nr_node_list_lock);
50	nr_node_for_each(nr_node, &nr_node_list)
51		if (ax25cmp(callsign, &nr_node->callsign) == 0) {
52			nr_node_hold(nr_node);
53			found = nr_node;
54			break;
55		}
56	spin_unlock_bh(&nr_node_list_lock);
57	return found;
58}
59
60static struct nr_neigh *nr_neigh_get_dev(ax25_address *callsign,
61					 struct net_device *dev)
62{
63	struct nr_neigh *found = NULL;
64	struct nr_neigh *nr_neigh;
65
66	spin_lock_bh(&nr_neigh_list_lock);
67	nr_neigh_for_each(nr_neigh, &nr_neigh_list)
68		if (ax25cmp(callsign, &nr_neigh->callsign) == 0 &&
69		    nr_neigh->dev == dev) {
70			nr_neigh_hold(nr_neigh);
71			found = nr_neigh;
72			break;
73		}
74	spin_unlock_bh(&nr_neigh_list_lock);
75	return found;
76}
77
78static void nr_remove_neigh(struct nr_neigh *);
79
80/*      re-sort the routes in quality order.    */
81static void re_sort_routes(struct nr_node *nr_node, int x, int y)
82{
83	if (nr_node->routes[y].quality > nr_node->routes[x].quality) {
84		if (nr_node->which == x)
85			nr_node->which = y;
86		else if (nr_node->which == y)
87			nr_node->which = x;
88
89		swap(nr_node->routes[x], nr_node->routes[y]);
90	}
91}
92
93/*
94 *	Add a new route to a node, and in the process add the node and the
95 *	neighbour if it is new.
96 */
97static int __must_check nr_add_node(ax25_address *nr, const char *mnemonic,
98	ax25_address *ax25, ax25_digi *ax25_digi, struct net_device *dev,
99	int quality, int obs_count)
100{
101	struct nr_node  *nr_node;
102	struct nr_neigh *nr_neigh;
103	int i, found;
104	struct net_device *odev;
105
106	if ((odev=nr_dev_get(nr)) != NULL) {	/* Can't add routes to ourself */
107		dev_put(odev);
108		return -EINVAL;
109	}
110
111	nr_node = nr_node_get(nr);
112
113	nr_neigh = nr_neigh_get_dev(ax25, dev);
114
115	/*
116	 * The L2 link to a neighbour has failed in the past
117	 * and now a frame comes from this neighbour. We assume
118	 * it was a temporary trouble with the link and reset the
119	 * routes now (and not wait for a node broadcast).
120	 */
121	if (nr_neigh != NULL && nr_neigh->failed != 0 && quality == 0) {
122		struct nr_node *nr_nodet;
123
124		spin_lock_bh(&nr_node_list_lock);
125		nr_node_for_each(nr_nodet, &nr_node_list) {
126			nr_node_lock(nr_nodet);
127			for (i = 0; i < nr_nodet->count; i++)
128				if (nr_nodet->routes[i].neighbour == nr_neigh)
129					if (i < nr_nodet->which)
130						nr_nodet->which = i;
131			nr_node_unlock(nr_nodet);
132		}
133		spin_unlock_bh(&nr_node_list_lock);
134	}
135
136	if (nr_neigh != NULL)
137		nr_neigh->failed = 0;
138
139	if (quality == 0 && nr_neigh != NULL && nr_node != NULL) {
140		nr_neigh_put(nr_neigh);
141		nr_node_put(nr_node);
142		return 0;
143	}
144
145	if (nr_neigh == NULL) {
146		if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL) {
147			if (nr_node)
148				nr_node_put(nr_node);
149			return -ENOMEM;
150		}
151
152		nr_neigh->callsign = *ax25;
153		nr_neigh->digipeat = NULL;
154		nr_neigh->ax25     = NULL;
155		nr_neigh->dev      = dev;
156		nr_neigh->quality  = sysctl_netrom_default_path_quality;
157		nr_neigh->locked   = 0;
158		nr_neigh->count    = 0;
159		nr_neigh->number   = nr_neigh_no++;
160		nr_neigh->failed   = 0;
161		refcount_set(&nr_neigh->refcount, 1);
162
163		if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
164			nr_neigh->digipeat = kmemdup(ax25_digi,
165						     sizeof(*ax25_digi),
166						     GFP_KERNEL);
167			if (nr_neigh->digipeat == NULL) {
168				kfree(nr_neigh);
169				if (nr_node)
170					nr_node_put(nr_node);
171				return -ENOMEM;
172			}
173		}
174
175		spin_lock_bh(&nr_neigh_list_lock);
176		hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
177		nr_neigh_hold(nr_neigh);
178		spin_unlock_bh(&nr_neigh_list_lock);
179	}
180
181	if (quality != 0 && ax25cmp(nr, ax25) == 0 && !nr_neigh->locked)
182		nr_neigh->quality = quality;
183
184	if (nr_node == NULL) {
185		if ((nr_node = kmalloc(sizeof(*nr_node), GFP_ATOMIC)) == NULL) {
186			if (nr_neigh)
187				nr_neigh_put(nr_neigh);
188			return -ENOMEM;
189		}
190
191		nr_node->callsign = *nr;
192		strcpy(nr_node->mnemonic, mnemonic);
193
194		nr_node->which = 0;
195		nr_node->count = 1;
196		refcount_set(&nr_node->refcount, 1);
197		spin_lock_init(&nr_node->node_lock);
198
199		nr_node->routes[0].quality   = quality;
200		nr_node->routes[0].obs_count = obs_count;
201		nr_node->routes[0].neighbour = nr_neigh;
202
203		nr_neigh_hold(nr_neigh);
204		nr_neigh->count++;
205
206		spin_lock_bh(&nr_node_list_lock);
207		hlist_add_head(&nr_node->node_node, &nr_node_list);
208		/* refcount initialized at 1 */
209		spin_unlock_bh(&nr_node_list_lock);
210
211		nr_neigh_put(nr_neigh);
212		return 0;
213	}
214	nr_node_lock(nr_node);
215
216	if (quality != 0)
217		strcpy(nr_node->mnemonic, mnemonic);
218
219	for (found = 0, i = 0; i < nr_node->count; i++) {
220		if (nr_node->routes[i].neighbour == nr_neigh) {
221			nr_node->routes[i].quality   = quality;
222			nr_node->routes[i].obs_count = obs_count;
223			found = 1;
224			break;
225		}
226	}
227
228	if (!found) {
229		/* We have space at the bottom, slot it in */
230		if (nr_node->count < 3) {
231			nr_node->routes[2] = nr_node->routes[1];
232			nr_node->routes[1] = nr_node->routes[0];
233
234			nr_node->routes[0].quality   = quality;
235			nr_node->routes[0].obs_count = obs_count;
236			nr_node->routes[0].neighbour = nr_neigh;
237
238			nr_node->which++;
239			nr_node->count++;
240			nr_neigh_hold(nr_neigh);
241			nr_neigh->count++;
242		} else {
243			/* It must be better than the worst */
244			if (quality > nr_node->routes[2].quality) {
245				nr_node->routes[2].neighbour->count--;
246				nr_neigh_put(nr_node->routes[2].neighbour);
247
248				if (nr_node->routes[2].neighbour->count == 0 && !nr_node->routes[2].neighbour->locked)
249					nr_remove_neigh(nr_node->routes[2].neighbour);
250
251				nr_node->routes[2].quality   = quality;
252				nr_node->routes[2].obs_count = obs_count;
253				nr_node->routes[2].neighbour = nr_neigh;
254
255				nr_neigh_hold(nr_neigh);
256				nr_neigh->count++;
257			}
258		}
259	}
260
261	/* Now re-sort the routes in quality order */
262	switch (nr_node->count) {
263	case 3:
264		re_sort_routes(nr_node, 0, 1);
265		re_sort_routes(nr_node, 1, 2);
266		fallthrough;
267	case 2:
268		re_sort_routes(nr_node, 0, 1);
269	case 1:
270		break;
271	}
272
273	for (i = 0; i < nr_node->count; i++) {
274		if (nr_node->routes[i].neighbour == nr_neigh) {
275			if (i < nr_node->which)
276				nr_node->which = i;
277			break;
278		}
279	}
280
281	nr_neigh_put(nr_neigh);
282	nr_node_unlock(nr_node);
283	nr_node_put(nr_node);
284	return 0;
285}
286
287static inline void __nr_remove_node(struct nr_node *nr_node)
288{
289	hlist_del_init(&nr_node->node_node);
290	nr_node_put(nr_node);
291}
292
293#define nr_remove_node_locked(__node) \
294	__nr_remove_node(__node)
295
296static void nr_remove_node(struct nr_node *nr_node)
297{
298	spin_lock_bh(&nr_node_list_lock);
299	__nr_remove_node(nr_node);
300	spin_unlock_bh(&nr_node_list_lock);
301}
302
303static inline void __nr_remove_neigh(struct nr_neigh *nr_neigh)
304{
305	hlist_del_init(&nr_neigh->neigh_node);
306	nr_neigh_put(nr_neigh);
307}
308
309#define nr_remove_neigh_locked(__neigh) \
310	__nr_remove_neigh(__neigh)
311
312static void nr_remove_neigh(struct nr_neigh *nr_neigh)
313{
314	spin_lock_bh(&nr_neigh_list_lock);
315	__nr_remove_neigh(nr_neigh);
316	spin_unlock_bh(&nr_neigh_list_lock);
317}
318
319/*
320 *	"Delete" a node. Strictly speaking remove a route to a node. The node
321 *	is only deleted if no routes are left to it.
322 */
323static int nr_del_node(ax25_address *callsign, ax25_address *neighbour, struct net_device *dev)
324{
325	struct nr_node  *nr_node;
326	struct nr_neigh *nr_neigh;
327	int i;
328
329	nr_node = nr_node_get(callsign);
330
331	if (nr_node == NULL)
332		return -EINVAL;
333
334	nr_neigh = nr_neigh_get_dev(neighbour, dev);
335
336	if (nr_neigh == NULL) {
337		nr_node_put(nr_node);
338		return -EINVAL;
339	}
340
341	nr_node_lock(nr_node);
342	for (i = 0; i < nr_node->count; i++) {
343		if (nr_node->routes[i].neighbour == nr_neigh) {
344			nr_neigh->count--;
345			nr_neigh_put(nr_neigh);
346
347			if (nr_neigh->count == 0 && !nr_neigh->locked)
348				nr_remove_neigh(nr_neigh);
349			nr_neigh_put(nr_neigh);
350
351			nr_node->count--;
352
353			if (nr_node->count == 0) {
354				nr_remove_node(nr_node);
355			} else {
356				switch (i) {
357				case 0:
358					nr_node->routes[0] = nr_node->routes[1];
359					fallthrough;
360				case 1:
361					nr_node->routes[1] = nr_node->routes[2];
362				case 2:
363					break;
364				}
365				nr_node_put(nr_node);
366			}
367			nr_node_unlock(nr_node);
368
369			return 0;
370		}
371	}
372	nr_neigh_put(nr_neigh);
373	nr_node_unlock(nr_node);
374	nr_node_put(nr_node);
375
376	return -EINVAL;
377}
378
379/*
380 *	Lock a neighbour with a quality.
381 */
382static int __must_check nr_add_neigh(ax25_address *callsign,
383	ax25_digi *ax25_digi, struct net_device *dev, unsigned int quality)
384{
385	struct nr_neigh *nr_neigh;
386
387	nr_neigh = nr_neigh_get_dev(callsign, dev);
388	if (nr_neigh) {
389		nr_neigh->quality = quality;
390		nr_neigh->locked  = 1;
391		nr_neigh_put(nr_neigh);
392		return 0;
393	}
394
395	if ((nr_neigh = kmalloc(sizeof(*nr_neigh), GFP_ATOMIC)) == NULL)
396		return -ENOMEM;
397
398	nr_neigh->callsign = *callsign;
399	nr_neigh->digipeat = NULL;
400	nr_neigh->ax25     = NULL;
401	nr_neigh->dev      = dev;
402	nr_neigh->quality  = quality;
403	nr_neigh->locked   = 1;
404	nr_neigh->count    = 0;
405	nr_neigh->number   = nr_neigh_no++;
406	nr_neigh->failed   = 0;
407	refcount_set(&nr_neigh->refcount, 1);
408
409	if (ax25_digi != NULL && ax25_digi->ndigi > 0) {
410		nr_neigh->digipeat = kmemdup(ax25_digi, sizeof(*ax25_digi),
411					     GFP_KERNEL);
412		if (nr_neigh->digipeat == NULL) {
413			kfree(nr_neigh);
414			return -ENOMEM;
415		}
416	}
417
418	spin_lock_bh(&nr_neigh_list_lock);
419	hlist_add_head(&nr_neigh->neigh_node, &nr_neigh_list);
420	/* refcount is initialized at 1 */
421	spin_unlock_bh(&nr_neigh_list_lock);
422
423	return 0;
424}
425
426/*
427 *	"Delete" a neighbour. The neighbour is only removed if the number
428 *	of nodes that may use it is zero.
429 */
430static int nr_del_neigh(ax25_address *callsign, struct net_device *dev, unsigned int quality)
431{
432	struct nr_neigh *nr_neigh;
433
434	nr_neigh = nr_neigh_get_dev(callsign, dev);
435
436	if (nr_neigh == NULL) return -EINVAL;
437
438	nr_neigh->quality = quality;
439	nr_neigh->locked  = 0;
440
441	if (nr_neigh->count == 0)
442		nr_remove_neigh(nr_neigh);
443	nr_neigh_put(nr_neigh);
444
445	return 0;
446}
447
448/*
449 *	Decrement the obsolescence count by one. If a route is reduced to a
450 *	count of zero, remove it. Also remove any unlocked neighbours with
451 *	zero nodes routing via it.
452 */
453static int nr_dec_obs(void)
454{
455	struct nr_neigh *nr_neigh;
456	struct nr_node  *s;
457	struct hlist_node *nodet;
458	int i;
459
460	spin_lock_bh(&nr_node_list_lock);
461	nr_node_for_each_safe(s, nodet, &nr_node_list) {
462		nr_node_lock(s);
463		for (i = 0; i < s->count; i++) {
464			switch (s->routes[i].obs_count) {
465			case 0:		/* A locked entry */
466				break;
467
468			case 1:		/* From 1 -> 0 */
469				nr_neigh = s->routes[i].neighbour;
470
471				nr_neigh->count--;
472				nr_neigh_put(nr_neigh);
473
474				if (nr_neigh->count == 0 && !nr_neigh->locked)
475					nr_remove_neigh(nr_neigh);
476
477				s->count--;
478
479				switch (i) {
480				case 0:
481					s->routes[0] = s->routes[1];
482					fallthrough;
483				case 1:
484					s->routes[1] = s->routes[2];
485				case 2:
486					break;
487				}
488				break;
489
490			default:
491				s->routes[i].obs_count--;
492				break;
493
494			}
495		}
496
497		if (s->count <= 0)
498			nr_remove_node_locked(s);
499		nr_node_unlock(s);
500	}
501	spin_unlock_bh(&nr_node_list_lock);
502
503	return 0;
504}
505
506/*
507 *	A device has been removed. Remove its routes and neighbours.
508 */
509void nr_rt_device_down(struct net_device *dev)
510{
511	struct nr_neigh *s;
512	struct hlist_node *nodet, *node2t;
513	struct nr_node  *t;
514	int i;
515
516	spin_lock_bh(&nr_neigh_list_lock);
517	nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
518		if (s->dev == dev) {
519			spin_lock_bh(&nr_node_list_lock);
520			nr_node_for_each_safe(t, node2t, &nr_node_list) {
521				nr_node_lock(t);
522				for (i = 0; i < t->count; i++) {
523					if (t->routes[i].neighbour == s) {
524						t->count--;
525
526						switch (i) {
527						case 0:
528							t->routes[0] = t->routes[1];
529							fallthrough;
530						case 1:
531							t->routes[1] = t->routes[2];
532						case 2:
533							break;
534						}
535					}
536				}
537
538				if (t->count <= 0)
539					nr_remove_node_locked(t);
540				nr_node_unlock(t);
541			}
542			spin_unlock_bh(&nr_node_list_lock);
543
544			nr_remove_neigh_locked(s);
545		}
546	}
547	spin_unlock_bh(&nr_neigh_list_lock);
548}
549
550/*
551 *	Check that the device given is a valid AX.25 interface that is "up".
552 *	Or a valid ethernet interface with an AX.25 callsign binding.
553 */
554static struct net_device *nr_ax25_dev_get(char *devname)
555{
556	struct net_device *dev;
557
558	if ((dev = dev_get_by_name(&init_net, devname)) == NULL)
559		return NULL;
560
561	if ((dev->flags & IFF_UP) && dev->type == ARPHRD_AX25)
562		return dev;
563
564	dev_put(dev);
565	return NULL;
566}
567
568/*
569 *	Find the first active NET/ROM device, usually "nr0".
570 */
571struct net_device *nr_dev_first(void)
572{
573	struct net_device *dev, *first = NULL;
574
575	rcu_read_lock();
576	for_each_netdev_rcu(&init_net, dev) {
577		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM)
578			if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
579				first = dev;
580	}
581	if (first)
582		dev_hold(first);
583	rcu_read_unlock();
584
585	return first;
586}
587
588/*
589 *	Find the NET/ROM device for the given callsign.
590 */
591struct net_device *nr_dev_get(ax25_address *addr)
592{
593	struct net_device *dev;
594
595	rcu_read_lock();
596	for_each_netdev_rcu(&init_net, dev) {
597		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM &&
598		    ax25cmp(addr, (ax25_address *)dev->dev_addr) == 0) {
599			dev_hold(dev);
600			goto out;
601		}
602	}
603	dev = NULL;
604out:
605	rcu_read_unlock();
606	return dev;
607}
608
609static ax25_digi *nr_call_to_digi(ax25_digi *digi, int ndigis,
610	ax25_address *digipeaters)
611{
612	int i;
613
614	if (ndigis == 0)
615		return NULL;
616
617	for (i = 0; i < ndigis; i++) {
618		digi->calls[i]    = digipeaters[i];
619		digi->repeated[i] = 0;
620	}
621
622	digi->ndigi      = ndigis;
623	digi->lastrepeat = -1;
624
625	return digi;
626}
627
628/*
629 *	Handle the ioctls that control the routing functions.
630 */
631int nr_rt_ioctl(unsigned int cmd, void __user *arg)
632{
633	struct nr_route_struct nr_route;
634	struct net_device *dev;
635	ax25_digi digi;
636	int ret;
637
638	switch (cmd) {
639	case SIOCADDRT:
640		if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
641			return -EFAULT;
642		if (nr_route.ndigis > AX25_MAX_DIGIS)
643			return -EINVAL;
644		if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
645			return -EINVAL;
646		switch (nr_route.type) {
647		case NETROM_NODE:
648			if (strnlen(nr_route.mnemonic, 7) == 7) {
649				ret = -EINVAL;
650				break;
651			}
652
653			ret = nr_add_node(&nr_route.callsign,
654				nr_route.mnemonic,
655				&nr_route.neighbour,
656				nr_call_to_digi(&digi, nr_route.ndigis,
657						nr_route.digipeaters),
658				dev, nr_route.quality,
659				nr_route.obs_count);
660			break;
661		case NETROM_NEIGH:
662			ret = nr_add_neigh(&nr_route.callsign,
663				nr_call_to_digi(&digi, nr_route.ndigis,
664						nr_route.digipeaters),
665				dev, nr_route.quality);
666			break;
667		default:
668			ret = -EINVAL;
669		}
670		dev_put(dev);
671		return ret;
672
673	case SIOCDELRT:
674		if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
675			return -EFAULT;
676		if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
677			return -EINVAL;
678		switch (nr_route.type) {
679		case NETROM_NODE:
680			ret = nr_del_node(&nr_route.callsign,
681				&nr_route.neighbour, dev);
682			break;
683		case NETROM_NEIGH:
684			ret = nr_del_neigh(&nr_route.callsign,
685				dev, nr_route.quality);
686			break;
687		default:
688			ret = -EINVAL;
689		}
690		dev_put(dev);
691		return ret;
692
693	case SIOCNRDECOBS:
694		return nr_dec_obs();
695
696	default:
697		return -EINVAL;
698	}
699
700	return 0;
701}
702
703/*
704 * 	A level 2 link has timed out, therefore it appears to be a poor link,
705 *	then don't use that neighbour until it is reset.
706 */
707void nr_link_failed(ax25_cb *ax25, int reason)
708{
709	struct nr_neigh *s, *nr_neigh = NULL;
710	struct nr_node  *nr_node = NULL;
711
712	spin_lock_bh(&nr_neigh_list_lock);
713	nr_neigh_for_each(s, &nr_neigh_list) {
714		if (s->ax25 == ax25) {
715			nr_neigh_hold(s);
716			nr_neigh = s;
717			break;
718		}
719	}
720	spin_unlock_bh(&nr_neigh_list_lock);
721
722	if (nr_neigh == NULL)
723		return;
724
725	nr_neigh->ax25 = NULL;
726	ax25_cb_put(ax25);
727
728	if (++nr_neigh->failed < sysctl_netrom_link_fails_count) {
729		nr_neigh_put(nr_neigh);
730		return;
731	}
732	spin_lock_bh(&nr_node_list_lock);
733	nr_node_for_each(nr_node, &nr_node_list) {
734		nr_node_lock(nr_node);
735		if (nr_node->which < nr_node->count &&
736		    nr_node->routes[nr_node->which].neighbour == nr_neigh)
737			nr_node->which++;
738		nr_node_unlock(nr_node);
739	}
740	spin_unlock_bh(&nr_node_list_lock);
741	nr_neigh_put(nr_neigh);
742}
743
744/*
745 *	Route a frame to an appropriate AX.25 connection. A NULL ax25_cb
746 *	indicates an internally generated frame.
747 */
748int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
749{
750	ax25_address *nr_src, *nr_dest;
751	struct nr_neigh *nr_neigh;
752	struct nr_node  *nr_node;
753	struct net_device *dev;
754	unsigned char *dptr;
755	ax25_cb *ax25s;
756	int ret;
757	struct sk_buff *skbn;
758
759
760	nr_src  = (ax25_address *)(skb->data + 0);
761	nr_dest = (ax25_address *)(skb->data + 7);
762
763	if (ax25 != NULL) {
764		ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
765				  ax25->ax25_dev->dev, 0,
766				  sysctl_netrom_obsolescence_count_initialiser);
767		if (ret)
768			return ret;
769	}
770
771	if ((dev = nr_dev_get(nr_dest)) != NULL) {	/* Its for me */
772		if (ax25 == NULL)			/* Its from me */
773			ret = nr_loopback_queue(skb);
774		else
775			ret = nr_rx_frame(skb, dev);
776		dev_put(dev);
777		return ret;
778	}
779
780	if (!sysctl_netrom_routing_control && ax25 != NULL)
781		return 0;
782
783	/* Its Time-To-Live has expired */
784	if (skb->data[14] == 1) {
785		return 0;
786	}
787
788	nr_node = nr_node_get(nr_dest);
789	if (nr_node == NULL)
790		return 0;
791	nr_node_lock(nr_node);
792
793	if (nr_node->which >= nr_node->count) {
794		nr_node_unlock(nr_node);
795		nr_node_put(nr_node);
796		return 0;
797	}
798
799	nr_neigh = nr_node->routes[nr_node->which].neighbour;
800
801	if ((dev = nr_dev_first()) == NULL) {
802		nr_node_unlock(nr_node);
803		nr_node_put(nr_node);
804		return 0;
805	}
806
807	/* We are going to change the netrom headers so we should get our
808	   own skb, we also did not know until now how much header space
809	   we had to reserve... - RXQ */
810	if ((skbn=skb_copy_expand(skb, dev->hard_header_len, 0, GFP_ATOMIC)) == NULL) {
811		nr_node_unlock(nr_node);
812		nr_node_put(nr_node);
813		dev_put(dev);
814		return 0;
815	}
816	kfree_skb(skb);
817	skb=skbn;
818	skb->data[14]--;
819
820	dptr  = skb_push(skb, 1);
821	*dptr = AX25_P_NETROM;
822
823	ax25s = nr_neigh->ax25;
824	nr_neigh->ax25 = ax25_send_frame(skb, 256,
825					 (ax25_address *)dev->dev_addr,
826					 &nr_neigh->callsign,
827					 nr_neigh->digipeat, nr_neigh->dev);
828	if (ax25s)
829		ax25_cb_put(ax25s);
830
831	dev_put(dev);
832	ret = (nr_neigh->ax25 != NULL);
833	nr_node_unlock(nr_node);
834	nr_node_put(nr_node);
835
836	return ret;
837}
838
839#ifdef CONFIG_PROC_FS
840
841static void *nr_node_start(struct seq_file *seq, loff_t *pos)
842	__acquires(&nr_node_list_lock)
843{
844	spin_lock_bh(&nr_node_list_lock);
845	return seq_hlist_start_head(&nr_node_list, *pos);
846}
847
848static void *nr_node_next(struct seq_file *seq, void *v, loff_t *pos)
849{
850	return seq_hlist_next(v, &nr_node_list, pos);
851}
852
853static void nr_node_stop(struct seq_file *seq, void *v)
854	__releases(&nr_node_list_lock)
855{
856	spin_unlock_bh(&nr_node_list_lock);
857}
858
859static int nr_node_show(struct seq_file *seq, void *v)
860{
861	char buf[11];
862	int i;
863
864	if (v == SEQ_START_TOKEN)
865		seq_puts(seq,
866			 "callsign  mnemonic w n qual obs neigh qual obs neigh qual obs neigh\n");
867	else {
868		struct nr_node *nr_node = hlist_entry(v, struct nr_node,
869						      node_node);
870
871		nr_node_lock(nr_node);
872		seq_printf(seq, "%-9s %-7s  %d %d",
873			ax2asc(buf, &nr_node->callsign),
874			(nr_node->mnemonic[0] == '\0') ? "*" : nr_node->mnemonic,
875			nr_node->which + 1,
876			nr_node->count);
877
878		for (i = 0; i < nr_node->count; i++) {
879			seq_printf(seq, "  %3d   %d %05d",
880				nr_node->routes[i].quality,
881				nr_node->routes[i].obs_count,
882				nr_node->routes[i].neighbour->number);
883		}
884		nr_node_unlock(nr_node);
885
886		seq_puts(seq, "\n");
887	}
888	return 0;
889}
890
891const struct seq_operations nr_node_seqops = {
892	.start = nr_node_start,
893	.next = nr_node_next,
894	.stop = nr_node_stop,
895	.show = nr_node_show,
896};
897
898static void *nr_neigh_start(struct seq_file *seq, loff_t *pos)
899	__acquires(&nr_neigh_list_lock)
900{
901	spin_lock_bh(&nr_neigh_list_lock);
902	return seq_hlist_start_head(&nr_neigh_list, *pos);
903}
904
905static void *nr_neigh_next(struct seq_file *seq, void *v, loff_t *pos)
906{
907	return seq_hlist_next(v, &nr_neigh_list, pos);
908}
909
910static void nr_neigh_stop(struct seq_file *seq, void *v)
911	__releases(&nr_neigh_list_lock)
912{
913	spin_unlock_bh(&nr_neigh_list_lock);
914}
915
916static int nr_neigh_show(struct seq_file *seq, void *v)
917{
918	char buf[11];
919	int i;
920
921	if (v == SEQ_START_TOKEN)
922		seq_puts(seq, "addr  callsign  dev  qual lock count failed digipeaters\n");
923	else {
924		struct nr_neigh *nr_neigh;
925
926		nr_neigh = hlist_entry(v, struct nr_neigh, neigh_node);
927		seq_printf(seq, "%05d %-9s %-4s  %3d    %d   %3d    %3d",
928			nr_neigh->number,
929			ax2asc(buf, &nr_neigh->callsign),
930			nr_neigh->dev ? nr_neigh->dev->name : "???",
931			nr_neigh->quality,
932			nr_neigh->locked,
933			nr_neigh->count,
934			nr_neigh->failed);
935
936		if (nr_neigh->digipeat != NULL) {
937			for (i = 0; i < nr_neigh->digipeat->ndigi; i++)
938				seq_printf(seq, " %s",
939					   ax2asc(buf, &nr_neigh->digipeat->calls[i]));
940		}
941
942		seq_puts(seq, "\n");
943	}
944	return 0;
945}
946
947const struct seq_operations nr_neigh_seqops = {
948	.start = nr_neigh_start,
949	.next = nr_neigh_next,
950	.stop = nr_neigh_stop,
951	.show = nr_neigh_show,
952};
953#endif
954
955/*
956 *	Free all memory associated with the nodes and routes lists.
957 */
958void nr_rt_free(void)
959{
960	struct nr_neigh *s = NULL;
961	struct nr_node  *t = NULL;
962	struct hlist_node *nodet;
963
964	spin_lock_bh(&nr_neigh_list_lock);
965	spin_lock_bh(&nr_node_list_lock);
966	nr_node_for_each_safe(t, nodet, &nr_node_list) {
967		nr_node_lock(t);
968		nr_remove_node_locked(t);
969		nr_node_unlock(t);
970	}
971	nr_neigh_for_each_safe(s, nodet, &nr_neigh_list) {
972		while(s->count) {
973			s->count--;
974			nr_neigh_put(s);
975		}
976		nr_remove_neigh_locked(s);
977	}
978	spin_unlock_bh(&nr_node_list_lock);
979	spin_unlock_bh(&nr_neigh_list_lock);
980}
981