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1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8 * Copyright Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
9 * Copyright Darryl Miles G7LED (dlm@g7led.demon.co.uk)
10 */
11#include <linux/module.h>
12#include <linux/moduleparam.h>
13#include <linux/capability.h>
14#include <linux/errno.h>
15#include <linux/types.h>
16#include <linux/socket.h>
17#include <linux/in.h>
18#include <linux/slab.h>
19#include <linux/kernel.h>
20#include <linux/sched.h>
21#include <linux/timer.h>
22#include <linux/string.h>
23#include <linux/sockios.h>
24#include <linux/net.h>
25#include <linux/stat.h>
26#include <net/ax25.h>
27#include <linux/inet.h>
28#include <linux/netdevice.h>
29#include <linux/if_arp.h>
30#include <linux/skbuff.h>
31#include <net/net_namespace.h>
32#include <net/sock.h>
33#include <linux/uaccess.h>
34#include <linux/fcntl.h>
35#include <linux/termios.h> /* For TIOCINQ/OUTQ */
36#include <linux/mm.h>
37#include <linux/interrupt.h>
38#include <linux/notifier.h>
39#include <net/netrom.h>
40#include <linux/proc_fs.h>
41#include <linux/seq_file.h>
42#include <net/ip.h>
43#include <net/tcp_states.h>
44#include <net/arp.h>
45#include <linux/init.h>
46
47static int nr_ndevs = 4;
48
49int sysctl_netrom_default_path_quality = NR_DEFAULT_QUAL;
50int sysctl_netrom_obsolescence_count_initialiser = NR_DEFAULT_OBS;
51int sysctl_netrom_network_ttl_initialiser = NR_DEFAULT_TTL;
52int sysctl_netrom_transport_timeout = NR_DEFAULT_T1;
53int sysctl_netrom_transport_maximum_tries = NR_DEFAULT_N2;
54int sysctl_netrom_transport_acknowledge_delay = NR_DEFAULT_T2;
55int sysctl_netrom_transport_busy_delay = NR_DEFAULT_T4;
56int sysctl_netrom_transport_requested_window_size = NR_DEFAULT_WINDOW;
57int sysctl_netrom_transport_no_activity_timeout = NR_DEFAULT_IDLE;
58int sysctl_netrom_routing_control = NR_DEFAULT_ROUTING;
59int sysctl_netrom_link_fails_count = NR_DEFAULT_FAILS;
60int sysctl_netrom_reset_circuit = NR_DEFAULT_RESET;
61
62static unsigned short circuit = 0x101;
63
64static HLIST_HEAD(nr_list);
65static DEFINE_SPINLOCK(nr_list_lock);
66
67static const struct proto_ops nr_proto_ops;
68
69/*
70 * NETROM network devices are virtual network devices encapsulating NETROM
71 * frames into AX.25 which will be sent through an AX.25 device, so form a
72 * special "super class" of normal net devices; split their locks off into a
73 * separate class since they always nest.
74 */
75static struct lock_class_key nr_netdev_xmit_lock_key;
76static struct lock_class_key nr_netdev_addr_lock_key;
77
78static void nr_set_lockdep_one(struct net_device *dev,
79 struct netdev_queue *txq,
80 void *_unused)
81{
82 lockdep_set_class(&txq->_xmit_lock, &nr_netdev_xmit_lock_key);
83}
84
85static void nr_set_lockdep_key(struct net_device *dev)
86{
87 lockdep_set_class(&dev->addr_list_lock, &nr_netdev_addr_lock_key);
88 netdev_for_each_tx_queue(dev, nr_set_lockdep_one, NULL);
89}
90
91/*
92 * Socket removal during an interrupt is now safe.
93 */
94static void nr_remove_socket(struct sock *sk)
95{
96 spin_lock_bh(&nr_list_lock);
97 sk_del_node_init(sk);
98 spin_unlock_bh(&nr_list_lock);
99}
100
101/*
102 * Kill all bound sockets on a dropped device.
103 */
104static void nr_kill_by_device(struct net_device *dev)
105{
106 struct sock *s;
107
108 spin_lock_bh(&nr_list_lock);
109 sk_for_each(s, &nr_list)
110 if (nr_sk(s)->device == dev)
111 nr_disconnect(s, ENETUNREACH);
112 spin_unlock_bh(&nr_list_lock);
113}
114
115/*
116 * Handle device status changes.
117 */
118static int nr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
119{
120 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
121
122 if (!net_eq(dev_net(dev), &init_net))
123 return NOTIFY_DONE;
124
125 if (event != NETDEV_DOWN)
126 return NOTIFY_DONE;
127
128 nr_kill_by_device(dev);
129 nr_rt_device_down(dev);
130
131 return NOTIFY_DONE;
132}
133
134/*
135 * Add a socket to the bound sockets list.
136 */
137static void nr_insert_socket(struct sock *sk)
138{
139 spin_lock_bh(&nr_list_lock);
140 sk_add_node(sk, &nr_list);
141 spin_unlock_bh(&nr_list_lock);
142}
143
144/*
145 * Find a socket that wants to accept the Connect Request we just
146 * received.
147 */
148static struct sock *nr_find_listener(ax25_address *addr)
149{
150 struct sock *s;
151
152 spin_lock_bh(&nr_list_lock);
153 sk_for_each(s, &nr_list)
154 if (!ax25cmp(&nr_sk(s)->source_addr, addr) &&
155 s->sk_state == TCP_LISTEN) {
156 bh_lock_sock(s);
157 goto found;
158 }
159 s = NULL;
160found:
161 spin_unlock_bh(&nr_list_lock);
162 return s;
163}
164
165/*
166 * Find a connected NET/ROM socket given my circuit IDs.
167 */
168static struct sock *nr_find_socket(unsigned char index, unsigned char id)
169{
170 struct sock *s;
171
172 spin_lock_bh(&nr_list_lock);
173 sk_for_each(s, &nr_list) {
174 struct nr_sock *nr = nr_sk(s);
175
176 if (nr->my_index == index && nr->my_id == id) {
177 bh_lock_sock(s);
178 goto found;
179 }
180 }
181 s = NULL;
182found:
183 spin_unlock_bh(&nr_list_lock);
184 return s;
185}
186
187/*
188 * Find a connected NET/ROM socket given their circuit IDs.
189 */
190static struct sock *nr_find_peer(unsigned char index, unsigned char id,
191 ax25_address *dest)
192{
193 struct sock *s;
194
195 spin_lock_bh(&nr_list_lock);
196 sk_for_each(s, &nr_list) {
197 struct nr_sock *nr = nr_sk(s);
198
199 if (nr->your_index == index && nr->your_id == id &&
200 !ax25cmp(&nr->dest_addr, dest)) {
201 bh_lock_sock(s);
202 goto found;
203 }
204 }
205 s = NULL;
206found:
207 spin_unlock_bh(&nr_list_lock);
208 return s;
209}
210
211/*
212 * Find next free circuit ID.
213 */
214static unsigned short nr_find_next_circuit(void)
215{
216 unsigned short id = circuit;
217 unsigned char i, j;
218 struct sock *sk;
219
220 for (;;) {
221 i = id / 256;
222 j = id % 256;
223
224 if (i != 0 && j != 0) {
225 if ((sk=nr_find_socket(i, j)) == NULL)
226 break;
227 bh_unlock_sock(sk);
228 }
229
230 id++;
231 }
232
233 return id;
234}
235
236/*
237 * Deferred destroy.
238 */
239void nr_destroy_socket(struct sock *);
240
241/*
242 * Handler for deferred kills.
243 */
244static void nr_destroy_timer(unsigned long data)
245{
246 struct sock *sk=(struct sock *)data;
247 bh_lock_sock(sk);
248 sock_hold(sk);
249 nr_destroy_socket(sk);
250 bh_unlock_sock(sk);
251 sock_put(sk);
252}
253
254/*
255 * This is called from user mode and the timers. Thus it protects itself
256 * against interrupt users but doesn't worry about being called during
257 * work. Once it is removed from the queue no interrupt or bottom half
258 * will touch it and we are (fairly 8-) ) safe.
259 */
260void nr_destroy_socket(struct sock *sk)
261{
262 struct sk_buff *skb;
263
264 nr_remove_socket(sk);
265
266 nr_stop_heartbeat(sk);
267 nr_stop_t1timer(sk);
268 nr_stop_t2timer(sk);
269 nr_stop_t4timer(sk);
270 nr_stop_idletimer(sk);
271
272 nr_clear_queues(sk); /* Flush the queues */
273
274 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
275 if (skb->sk != sk) { /* A pending connection */
276 /* Queue the unaccepted socket for death */
277 sock_set_flag(skb->sk, SOCK_DEAD);
278 nr_start_heartbeat(skb->sk);
279 nr_sk(skb->sk)->state = NR_STATE_0;
280 }
281
282 kfree_skb(skb);
283 }
284
285 if (sk_has_allocations(sk)) {
286 /* Defer: outstanding buffers */
287 sk->sk_timer.function = nr_destroy_timer;
288 sk->sk_timer.expires = jiffies + 2 * HZ;
289 add_timer(&sk->sk_timer);
290 } else
291 sock_put(sk);
292}
293
294/*
295 * Handling for system calls applied via the various interfaces to a
296 * NET/ROM socket object.
297 */
298
299static int nr_setsockopt(struct socket *sock, int level, int optname,
300 char __user *optval, unsigned int optlen)
301{
302 struct sock *sk = sock->sk;
303 struct nr_sock *nr = nr_sk(sk);
304 unsigned long opt;
305
306 if (level != SOL_NETROM)
307 return -ENOPROTOOPT;
308
309 if (optlen < sizeof(unsigned int))
310 return -EINVAL;
311
312 if (get_user(opt, (unsigned int __user *)optval))
313 return -EFAULT;
314
315 switch (optname) {
316 case NETROM_T1:
317 if (opt < 1 || opt > ULONG_MAX / HZ)
318 return -EINVAL;
319 nr->t1 = opt * HZ;
320 return 0;
321
322 case NETROM_T2:
323 if (opt < 1 || opt > ULONG_MAX / HZ)
324 return -EINVAL;
325 nr->t2 = opt * HZ;
326 return 0;
327
328 case NETROM_N2:
329 if (opt < 1 || opt > 31)
330 return -EINVAL;
331 nr->n2 = opt;
332 return 0;
333
334 case NETROM_T4:
335 if (opt < 1 || opt > ULONG_MAX / HZ)
336 return -EINVAL;
337 nr->t4 = opt * HZ;
338 return 0;
339
340 case NETROM_IDLE:
341 if (opt > ULONG_MAX / (60 * HZ))
342 return -EINVAL;
343 nr->idle = opt * 60 * HZ;
344 return 0;
345
346 default:
347 return -ENOPROTOOPT;
348 }
349}
350
351static int nr_getsockopt(struct socket *sock, int level, int optname,
352 char __user *optval, int __user *optlen)
353{
354 struct sock *sk = sock->sk;
355 struct nr_sock *nr = nr_sk(sk);
356 int val = 0;
357 int len;
358
359 if (level != SOL_NETROM)
360 return -ENOPROTOOPT;
361
362 if (get_user(len, optlen))
363 return -EFAULT;
364
365 if (len < 0)
366 return -EINVAL;
367
368 switch (optname) {
369 case NETROM_T1:
370 val = nr->t1 / HZ;
371 break;
372
373 case NETROM_T2:
374 val = nr->t2 / HZ;
375 break;
376
377 case NETROM_N2:
378 val = nr->n2;
379 break;
380
381 case NETROM_T4:
382 val = nr->t4 / HZ;
383 break;
384
385 case NETROM_IDLE:
386 val = nr->idle / (60 * HZ);
387 break;
388
389 default:
390 return -ENOPROTOOPT;
391 }
392
393 len = min_t(unsigned int, len, sizeof(int));
394
395 if (put_user(len, optlen))
396 return -EFAULT;
397
398 return copy_to_user(optval, &val, len) ? -EFAULT : 0;
399}
400
401static int nr_listen(struct socket *sock, int backlog)
402{
403 struct sock *sk = sock->sk;
404
405 lock_sock(sk);
406 if (sk->sk_state != TCP_LISTEN) {
407 memset(&nr_sk(sk)->user_addr, 0, AX25_ADDR_LEN);
408 sk->sk_max_ack_backlog = backlog;
409 sk->sk_state = TCP_LISTEN;
410 release_sock(sk);
411 return 0;
412 }
413 release_sock(sk);
414
415 return -EOPNOTSUPP;
416}
417
418static struct proto nr_proto = {
419 .name = "NETROM",
420 .owner = THIS_MODULE,
421 .obj_size = sizeof(struct nr_sock),
422};
423
424static int nr_create(struct net *net, struct socket *sock, int protocol,
425 int kern)
426{
427 struct sock *sk;
428 struct nr_sock *nr;
429
430 if (!net_eq(net, &init_net))
431 return -EAFNOSUPPORT;
432
433 if (sock->type != SOCK_SEQPACKET || protocol != 0)
434 return -ESOCKTNOSUPPORT;
435
436 sk = sk_alloc(net, PF_NETROM, GFP_ATOMIC, &nr_proto, kern);
437 if (sk == NULL)
438 return -ENOMEM;
439
440 nr = nr_sk(sk);
441
442 sock_init_data(sock, sk);
443
444 sock->ops = &nr_proto_ops;
445 sk->sk_protocol = protocol;
446
447 skb_queue_head_init(&nr->ack_queue);
448 skb_queue_head_init(&nr->reseq_queue);
449 skb_queue_head_init(&nr->frag_queue);
450
451 nr_init_timers(sk);
452
453 nr->t1 =
454 msecs_to_jiffies(sysctl_netrom_transport_timeout);
455 nr->t2 =
456 msecs_to_jiffies(sysctl_netrom_transport_acknowledge_delay);
457 nr->n2 =
458 msecs_to_jiffies(sysctl_netrom_transport_maximum_tries);
459 nr->t4 =
460 msecs_to_jiffies(sysctl_netrom_transport_busy_delay);
461 nr->idle =
462 msecs_to_jiffies(sysctl_netrom_transport_no_activity_timeout);
463 nr->window = sysctl_netrom_transport_requested_window_size;
464
465 nr->bpqext = 1;
466 nr->state = NR_STATE_0;
467
468 return 0;
469}
470
471static struct sock *nr_make_new(struct sock *osk)
472{
473 struct sock *sk;
474 struct nr_sock *nr, *onr;
475
476 if (osk->sk_type != SOCK_SEQPACKET)
477 return NULL;
478
479 sk = sk_alloc(sock_net(osk), PF_NETROM, GFP_ATOMIC, osk->sk_prot, 0);
480 if (sk == NULL)
481 return NULL;
482
483 nr = nr_sk(sk);
484
485 sock_init_data(NULL, sk);
486
487 sk->sk_type = osk->sk_type;
488 sk->sk_priority = osk->sk_priority;
489 sk->sk_protocol = osk->sk_protocol;
490 sk->sk_rcvbuf = osk->sk_rcvbuf;
491 sk->sk_sndbuf = osk->sk_sndbuf;
492 sk->sk_state = TCP_ESTABLISHED;
493 sock_copy_flags(sk, osk);
494
495 skb_queue_head_init(&nr->ack_queue);
496 skb_queue_head_init(&nr->reseq_queue);
497 skb_queue_head_init(&nr->frag_queue);
498
499 nr_init_timers(sk);
500
501 onr = nr_sk(osk);
502
503 nr->t1 = onr->t1;
504 nr->t2 = onr->t2;
505 nr->n2 = onr->n2;
506 nr->t4 = onr->t4;
507 nr->idle = onr->idle;
508 nr->window = onr->window;
509
510 nr->device = onr->device;
511 nr->bpqext = onr->bpqext;
512
513 return sk;
514}
515
516static int nr_release(struct socket *sock)
517{
518 struct sock *sk = sock->sk;
519 struct nr_sock *nr;
520
521 if (sk == NULL) return 0;
522
523 sock_hold(sk);
524 sock_orphan(sk);
525 lock_sock(sk);
526 nr = nr_sk(sk);
527
528 switch (nr->state) {
529 case NR_STATE_0:
530 case NR_STATE_1:
531 case NR_STATE_2:
532 nr_disconnect(sk, 0);
533 nr_destroy_socket(sk);
534 break;
535
536 case NR_STATE_3:
537 nr_clear_queues(sk);
538 nr->n2count = 0;
539 nr_write_internal(sk, NR_DISCREQ);
540 nr_start_t1timer(sk);
541 nr_stop_t2timer(sk);
542 nr_stop_t4timer(sk);
543 nr_stop_idletimer(sk);
544 nr->state = NR_STATE_2;
545 sk->sk_state = TCP_CLOSE;
546 sk->sk_shutdown |= SEND_SHUTDOWN;
547 sk->sk_state_change(sk);
548 sock_set_flag(sk, SOCK_DESTROY);
549 break;
550
551 default:
552 break;
553 }
554
555 sock->sk = NULL;
556 release_sock(sk);
557 sock_put(sk);
558
559 return 0;
560}
561
562static int nr_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
563{
564 struct sock *sk = sock->sk;
565 struct nr_sock *nr = nr_sk(sk);
566 struct full_sockaddr_ax25 *addr = (struct full_sockaddr_ax25 *)uaddr;
567 struct net_device *dev;
568 ax25_uid_assoc *user;
569 ax25_address *source;
570
571 lock_sock(sk);
572 if (!sock_flag(sk, SOCK_ZAPPED)) {
573 release_sock(sk);
574 return -EINVAL;
575 }
576 if (addr_len < sizeof(struct sockaddr_ax25) || addr_len > sizeof(struct full_sockaddr_ax25)) {
577 release_sock(sk);
578 return -EINVAL;
579 }
580 if (addr_len < (addr->fsa_ax25.sax25_ndigis * sizeof(ax25_address) + sizeof(struct sockaddr_ax25))) {
581 release_sock(sk);
582 return -EINVAL;
583 }
584 if (addr->fsa_ax25.sax25_family != AF_NETROM) {
585 release_sock(sk);
586 return -EINVAL;
587 }
588 if ((dev = nr_dev_get(&addr->fsa_ax25.sax25_call)) == NULL) {
589 release_sock(sk);
590 return -EADDRNOTAVAIL;
591 }
592
593 /*
594 * Only the super user can set an arbitrary user callsign.
595 */
596 if (addr->fsa_ax25.sax25_ndigis == 1) {
597 if (!capable(CAP_NET_BIND_SERVICE)) {
598 dev_put(dev);
599 release_sock(sk);
600 return -EPERM;
601 }
602 nr->user_addr = addr->fsa_digipeater[0];
603 nr->source_addr = addr->fsa_ax25.sax25_call;
604 } else {
605 source = &addr->fsa_ax25.sax25_call;
606
607 user = ax25_findbyuid(current_euid());
608 if (user) {
609 nr->user_addr = user->call;
610 ax25_uid_put(user);
611 } else {
612 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
613 release_sock(sk);
614 dev_put(dev);
615 return -EPERM;
616 }
617 nr->user_addr = *source;
618 }
619
620 nr->source_addr = *source;
621 }
622
623 nr->device = dev;
624 nr_insert_socket(sk);
625
626 sock_reset_flag(sk, SOCK_ZAPPED);
627 dev_put(dev);
628 release_sock(sk);
629
630 return 0;
631}
632
633static int nr_connect(struct socket *sock, struct sockaddr *uaddr,
634 int addr_len, int flags)
635{
636 struct sock *sk = sock->sk;
637 struct nr_sock *nr = nr_sk(sk);
638 struct sockaddr_ax25 *addr = (struct sockaddr_ax25 *)uaddr;
639 ax25_address *source = NULL;
640 ax25_uid_assoc *user;
641 struct net_device *dev;
642 int err = 0;
643
644 lock_sock(sk);
645 if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
646 sock->state = SS_CONNECTED;
647 goto out_release; /* Connect completed during a ERESTARTSYS event */
648 }
649
650 if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
651 sock->state = SS_UNCONNECTED;
652 err = -ECONNREFUSED;
653 goto out_release;
654 }
655
656 if (sk->sk_state == TCP_ESTABLISHED) {
657 err = -EISCONN; /* No reconnect on a seqpacket socket */
658 goto out_release;
659 }
660
661 sk->sk_state = TCP_CLOSE;
662 sock->state = SS_UNCONNECTED;
663
664 if (addr_len != sizeof(struct sockaddr_ax25) && addr_len != sizeof(struct full_sockaddr_ax25)) {
665 err = -EINVAL;
666 goto out_release;
667 }
668 if (addr->sax25_family != AF_NETROM) {
669 err = -EINVAL;
670 goto out_release;
671 }
672 if (sock_flag(sk, SOCK_ZAPPED)) { /* Must bind first - autobinding in this may or may not work */
673 sock_reset_flag(sk, SOCK_ZAPPED);
674
675 if ((dev = nr_dev_first()) == NULL) {
676 err = -ENETUNREACH;
677 goto out_release;
678 }
679 source = (ax25_address *)dev->dev_addr;
680
681 user = ax25_findbyuid(current_euid());
682 if (user) {
683 nr->user_addr = user->call;
684 ax25_uid_put(user);
685 } else {
686 if (ax25_uid_policy && !capable(CAP_NET_ADMIN)) {
687 dev_put(dev);
688 err = -EPERM;
689 goto out_release;
690 }
691 nr->user_addr = *source;
692 }
693
694 nr->source_addr = *source;
695 nr->device = dev;
696
697 dev_put(dev);
698 nr_insert_socket(sk); /* Finish the bind */
699 }
700
701 nr->dest_addr = addr->sax25_call;
702
703 release_sock(sk);
704 circuit = nr_find_next_circuit();
705 lock_sock(sk);
706
707 nr->my_index = circuit / 256;
708 nr->my_id = circuit % 256;
709
710 circuit++;
711
712 /* Move to connecting socket, start sending Connect Requests */
713 sock->state = SS_CONNECTING;
714 sk->sk_state = TCP_SYN_SENT;
715
716 nr_establish_data_link(sk);
717
718 nr->state = NR_STATE_1;
719
720 nr_start_heartbeat(sk);
721
722 /* Now the loop */
723 if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK)) {
724 err = -EINPROGRESS;
725 goto out_release;
726 }
727
728 /*
729 * A Connect Ack with Choke or timeout or failed routing will go to
730 * closed.
731 */
732 if (sk->sk_state == TCP_SYN_SENT) {
733 DEFINE_WAIT(wait);
734
735 for (;;) {
736 prepare_to_wait(sk_sleep(sk), &wait,
737 TASK_INTERRUPTIBLE);
738 if (sk->sk_state != TCP_SYN_SENT)
739 break;
740 if (!signal_pending(current)) {
741 release_sock(sk);
742 schedule();
743 lock_sock(sk);
744 continue;
745 }
746 err = -ERESTARTSYS;
747 break;
748 }
749 finish_wait(sk_sleep(sk), &wait);
750 if (err)
751 goto out_release;
752 }
753
754 if (sk->sk_state != TCP_ESTABLISHED) {
755 sock->state = SS_UNCONNECTED;
756 err = sock_error(sk); /* Always set at this point */
757 goto out_release;
758 }
759
760 sock->state = SS_CONNECTED;
761
762out_release:
763 release_sock(sk);
764
765 return err;
766}
767
768static int nr_accept(struct socket *sock, struct socket *newsock, int flags)
769{
770 struct sk_buff *skb;
771 struct sock *newsk;
772 DEFINE_WAIT(wait);
773 struct sock *sk;
774 int err = 0;
775
776 if ((sk = sock->sk) == NULL)
777 return -EINVAL;
778
779 lock_sock(sk);
780 if (sk->sk_type != SOCK_SEQPACKET) {
781 err = -EOPNOTSUPP;
782 goto out_release;
783 }
784
785 if (sk->sk_state != TCP_LISTEN) {
786 err = -EINVAL;
787 goto out_release;
788 }
789
790 /*
791 * The write queue this time is holding sockets ready to use
792 * hooked into the SABM we saved
793 */
794 for (;;) {
795 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
796 skb = skb_dequeue(&sk->sk_receive_queue);
797 if (skb)
798 break;
799
800 if (flags & O_NONBLOCK) {
801 err = -EWOULDBLOCK;
802 break;
803 }
804 if (!signal_pending(current)) {
805 release_sock(sk);
806 schedule();
807 lock_sock(sk);
808 continue;
809 }
810 err = -ERESTARTSYS;
811 break;
812 }
813 finish_wait(sk_sleep(sk), &wait);
814 if (err)
815 goto out_release;
816
817 newsk = skb->sk;
818 sock_graft(newsk, newsock);
819
820 /* Now attach up the new socket */
821 kfree_skb(skb);
822 sk_acceptq_removed(sk);
823
824out_release:
825 release_sock(sk);
826
827 return err;
828}
829
830static int nr_getname(struct socket *sock, struct sockaddr *uaddr,
831 int *uaddr_len, int peer)
832{
833 struct full_sockaddr_ax25 *sax = (struct full_sockaddr_ax25 *)uaddr;
834 struct sock *sk = sock->sk;
835 struct nr_sock *nr = nr_sk(sk);
836
837 memset(&sax->fsa_ax25, 0, sizeof(struct sockaddr_ax25));
838
839 lock_sock(sk);
840 if (peer != 0) {
841 if (sk->sk_state != TCP_ESTABLISHED) {
842 release_sock(sk);
843 return -ENOTCONN;
844 }
845 sax->fsa_ax25.sax25_family = AF_NETROM;
846 sax->fsa_ax25.sax25_ndigis = 1;
847 sax->fsa_ax25.sax25_call = nr->user_addr;
848 memset(sax->fsa_digipeater, 0, sizeof(sax->fsa_digipeater));
849 sax->fsa_digipeater[0] = nr->dest_addr;
850 *uaddr_len = sizeof(struct full_sockaddr_ax25);
851 } else {
852 sax->fsa_ax25.sax25_family = AF_NETROM;
853 sax->fsa_ax25.sax25_ndigis = 0;
854 sax->fsa_ax25.sax25_call = nr->source_addr;
855 *uaddr_len = sizeof(struct sockaddr_ax25);
856 }
857 release_sock(sk);
858
859 return 0;
860}
861
862int nr_rx_frame(struct sk_buff *skb, struct net_device *dev)
863{
864 struct sock *sk;
865 struct sock *make;
866 struct nr_sock *nr_make;
867 ax25_address *src, *dest, *user;
868 unsigned short circuit_index, circuit_id;
869 unsigned short peer_circuit_index, peer_circuit_id;
870 unsigned short frametype, flags, window, timeout;
871 int ret;
872
873 skb->sk = NULL; /* Initially we don't know who it's for */
874
875 /*
876 * skb->data points to the netrom frame start
877 */
878
879 src = (ax25_address *)(skb->data + 0);
880 dest = (ax25_address *)(skb->data + 7);
881
882 circuit_index = skb->data[15];
883 circuit_id = skb->data[16];
884 peer_circuit_index = skb->data[17];
885 peer_circuit_id = skb->data[18];
886 frametype = skb->data[19] & 0x0F;
887 flags = skb->data[19] & 0xF0;
888
889 /*
890 * Check for an incoming IP over NET/ROM frame.
891 */
892 if (frametype == NR_PROTOEXT &&
893 circuit_index == NR_PROTO_IP && circuit_id == NR_PROTO_IP) {
894 skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
895 skb_reset_transport_header(skb);
896
897 return nr_rx_ip(skb, dev);
898 }
899
900 /*
901 * Find an existing socket connection, based on circuit ID, if it's
902 * a Connect Request base it on their circuit ID.
903 *
904 * Circuit ID 0/0 is not valid but it could still be a "reset" for a
905 * circuit that no longer exists at the other end ...
906 */
907
908 sk = NULL;
909
910 if (circuit_index == 0 && circuit_id == 0) {
911 if (frametype == NR_CONNACK && flags == NR_CHOKE_FLAG)
912 sk = nr_find_peer(peer_circuit_index, peer_circuit_id, src);
913 } else {
914 if (frametype == NR_CONNREQ)
915 sk = nr_find_peer(circuit_index, circuit_id, src);
916 else
917 sk = nr_find_socket(circuit_index, circuit_id);
918 }
919
920 if (sk != NULL) {
921 skb_reset_transport_header(skb);
922
923 if (frametype == NR_CONNACK && skb->len == 22)
924 nr_sk(sk)->bpqext = 1;
925 else
926 nr_sk(sk)->bpqext = 0;
927
928 ret = nr_process_rx_frame(sk, skb);
929 bh_unlock_sock(sk);
930 return ret;
931 }
932
933 /*
934 * Now it should be a CONNREQ.
935 */
936 if (frametype != NR_CONNREQ) {
937 /*
938 * Here it would be nice to be able to send a reset but
939 * NET/ROM doesn't have one. We've tried to extend the protocol
940 * by sending NR_CONNACK | NR_CHOKE_FLAGS replies but that
941 * apparently kills BPQ boxes... :-(
942 * So now we try to follow the established behaviour of
943 * G8PZT's Xrouter which is sending packets with command type 7
944 * as an extension of the protocol.
945 */
946 if (sysctl_netrom_reset_circuit &&
947 (frametype != NR_RESET || flags != 0))
948 nr_transmit_reset(skb, 1);
949
950 return 0;
951 }
952
953 sk = nr_find_listener(dest);
954
955 user = (ax25_address *)(skb->data + 21);
956
957 if (sk == NULL || sk_acceptq_is_full(sk) ||
958 (make = nr_make_new(sk)) == NULL) {
959 nr_transmit_refusal(skb, 0);
960 if (sk)
961 bh_unlock_sock(sk);
962 return 0;
963 }
964
965 window = skb->data[20];
966
967 skb->sk = make;
968 make->sk_state = TCP_ESTABLISHED;
969
970 /* Fill in his circuit details */
971 nr_make = nr_sk(make);
972 nr_make->source_addr = *dest;
973 nr_make->dest_addr = *src;
974 nr_make->user_addr = *user;
975
976 nr_make->your_index = circuit_index;
977 nr_make->your_id = circuit_id;
978
979 bh_unlock_sock(sk);
980 circuit = nr_find_next_circuit();
981 bh_lock_sock(sk);
982
983 nr_make->my_index = circuit / 256;
984 nr_make->my_id = circuit % 256;
985
986 circuit++;
987
988 /* Window negotiation */
989 if (window < nr_make->window)
990 nr_make->window = window;
991
992 /* L4 timeout negotiation */
993 if (skb->len == 37) {
994 timeout = skb->data[36] * 256 + skb->data[35];
995 if (timeout * HZ < nr_make->t1)
996 nr_make->t1 = timeout * HZ;
997 nr_make->bpqext = 1;
998 } else {
999 nr_make->bpqext = 0;
1000 }
1001
1002 nr_write_internal(make, NR_CONNACK);
1003
1004 nr_make->condition = 0x00;
1005 nr_make->vs = 0;
1006 nr_make->va = 0;
1007 nr_make->vr = 0;
1008 nr_make->vl = 0;
1009 nr_make->state = NR_STATE_3;
1010 sk_acceptq_added(sk);
1011 skb_queue_head(&sk->sk_receive_queue, skb);
1012
1013 if (!sock_flag(sk, SOCK_DEAD))
1014 sk->sk_data_ready(sk);
1015
1016 bh_unlock_sock(sk);
1017
1018 nr_insert_socket(make);
1019
1020 nr_start_heartbeat(make);
1021 nr_start_idletimer(make);
1022
1023 return 1;
1024}
1025
1026static int nr_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1027{
1028 struct sock *sk = sock->sk;
1029 struct nr_sock *nr = nr_sk(sk);
1030 DECLARE_SOCKADDR(struct sockaddr_ax25 *, usax, msg->msg_name);
1031 int err;
1032 struct sockaddr_ax25 sax;
1033 struct sk_buff *skb;
1034 unsigned char *asmptr;
1035 int size;
1036
1037 if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_CMSG_COMPAT))
1038 return -EINVAL;
1039
1040 lock_sock(sk);
1041 if (sock_flag(sk, SOCK_ZAPPED)) {
1042 err = -EADDRNOTAVAIL;
1043 goto out;
1044 }
1045
1046 if (sk->sk_shutdown & SEND_SHUTDOWN) {
1047 send_sig(SIGPIPE, current, 0);
1048 err = -EPIPE;
1049 goto out;
1050 }
1051
1052 if (nr->device == NULL) {
1053 err = -ENETUNREACH;
1054 goto out;
1055 }
1056
1057 if (usax) {
1058 if (msg->msg_namelen < sizeof(sax)) {
1059 err = -EINVAL;
1060 goto out;
1061 }
1062 sax = *usax;
1063 if (ax25cmp(&nr->dest_addr, &sax.sax25_call) != 0) {
1064 err = -EISCONN;
1065 goto out;
1066 }
1067 if (sax.sax25_family != AF_NETROM) {
1068 err = -EINVAL;
1069 goto out;
1070 }
1071 } else {
1072 if (sk->sk_state != TCP_ESTABLISHED) {
1073 err = -ENOTCONN;
1074 goto out;
1075 }
1076 sax.sax25_family = AF_NETROM;
1077 sax.sax25_call = nr->dest_addr;
1078 }
1079
1080 /* Build a packet - the conventional user limit is 236 bytes. We can
1081 do ludicrously large NetROM frames but must not overflow */
1082 if (len > 65536) {
1083 err = -EMSGSIZE;
1084 goto out;
1085 }
1086
1087 size = len + NR_NETWORK_LEN + NR_TRANSPORT_LEN;
1088
1089 if ((skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT, &err)) == NULL)
1090 goto out;
1091
1092 skb_reserve(skb, size - len);
1093 skb_reset_transport_header(skb);
1094
1095 /*
1096 * Push down the NET/ROM header
1097 */
1098
1099 asmptr = skb_push(skb, NR_TRANSPORT_LEN);
1100
1101 /* Build a NET/ROM Transport header */
1102
1103 *asmptr++ = nr->your_index;
1104 *asmptr++ = nr->your_id;
1105 *asmptr++ = 0; /* To be filled in later */
1106 *asmptr++ = 0; /* Ditto */
1107 *asmptr++ = NR_INFO;
1108
1109 /*
1110 * Put the data on the end
1111 */
1112 skb_put(skb, len);
1113
1114 /* User data follows immediately after the NET/ROM transport header */
1115 if (memcpy_from_msg(skb_transport_header(skb), msg, len)) {
1116 kfree_skb(skb);
1117 err = -EFAULT;
1118 goto out;
1119 }
1120
1121 if (sk->sk_state != TCP_ESTABLISHED) {
1122 kfree_skb(skb);
1123 err = -ENOTCONN;
1124 goto out;
1125 }
1126
1127 nr_output(sk, skb); /* Shove it onto the queue */
1128
1129 err = len;
1130out:
1131 release_sock(sk);
1132 return err;
1133}
1134
1135static int nr_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1136 int flags)
1137{
1138 struct sock *sk = sock->sk;
1139 DECLARE_SOCKADDR(struct sockaddr_ax25 *, sax, msg->msg_name);
1140 size_t copied;
1141 struct sk_buff *skb;
1142 int er;
1143
1144 /*
1145 * This works for seqpacket too. The receiver has ordered the queue for
1146 * us! We do one quick check first though
1147 */
1148
1149 lock_sock(sk);
1150 if (sk->sk_state != TCP_ESTABLISHED) {
1151 release_sock(sk);
1152 return -ENOTCONN;
1153 }
1154
1155 /* Now we can treat all alike */
1156 if ((skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &er)) == NULL) {
1157 release_sock(sk);
1158 return er;
1159 }
1160
1161 skb_reset_transport_header(skb);
1162 copied = skb->len;
1163
1164 if (copied > size) {
1165 copied = size;
1166 msg->msg_flags |= MSG_TRUNC;
1167 }
1168
1169 er = skb_copy_datagram_msg(skb, 0, msg, copied);
1170 if (er < 0) {
1171 skb_free_datagram(sk, skb);
1172 release_sock(sk);
1173 return er;
1174 }
1175
1176 if (sax != NULL) {
1177 memset(sax, 0, sizeof(*sax));
1178 sax->sax25_family = AF_NETROM;
1179 skb_copy_from_linear_data_offset(skb, 7, sax->sax25_call.ax25_call,
1180 AX25_ADDR_LEN);
1181 msg->msg_namelen = sizeof(*sax);
1182 }
1183
1184 skb_free_datagram(sk, skb);
1185
1186 release_sock(sk);
1187 return copied;
1188}
1189
1190
1191static int nr_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1192{
1193 struct sock *sk = sock->sk;
1194 void __user *argp = (void __user *)arg;
1195 int ret;
1196
1197 switch (cmd) {
1198 case TIOCOUTQ: {
1199 long amount;
1200
1201 lock_sock(sk);
1202 amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1203 if (amount < 0)
1204 amount = 0;
1205 release_sock(sk);
1206 return put_user(amount, (int __user *)argp);
1207 }
1208
1209 case TIOCINQ: {
1210 struct sk_buff *skb;
1211 long amount = 0L;
1212
1213 lock_sock(sk);
1214 /* These two are safe on a single CPU system as only user tasks fiddle here */
1215 if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1216 amount = skb->len;
1217 release_sock(sk);
1218 return put_user(amount, (int __user *)argp);
1219 }
1220
1221 case SIOCGSTAMP:
1222 lock_sock(sk);
1223 ret = sock_get_timestamp(sk, argp);
1224 release_sock(sk);
1225 return ret;
1226
1227 case SIOCGSTAMPNS:
1228 lock_sock(sk);
1229 ret = sock_get_timestampns(sk, argp);
1230 release_sock(sk);
1231 return ret;
1232
1233 case SIOCGIFADDR:
1234 case SIOCSIFADDR:
1235 case SIOCGIFDSTADDR:
1236 case SIOCSIFDSTADDR:
1237 case SIOCGIFBRDADDR:
1238 case SIOCSIFBRDADDR:
1239 case SIOCGIFNETMASK:
1240 case SIOCSIFNETMASK:
1241 case SIOCGIFMETRIC:
1242 case SIOCSIFMETRIC:
1243 return -EINVAL;
1244
1245 case SIOCADDRT:
1246 case SIOCDELRT:
1247 case SIOCNRDECOBS:
1248 if (!capable(CAP_NET_ADMIN))
1249 return -EPERM;
1250 return nr_rt_ioctl(cmd, argp);
1251
1252 default:
1253 return -ENOIOCTLCMD;
1254 }
1255
1256 return 0;
1257}
1258
1259#ifdef CONFIG_PROC_FS
1260
1261static void *nr_info_start(struct seq_file *seq, loff_t *pos)
1262{
1263 spin_lock_bh(&nr_list_lock);
1264 return seq_hlist_start_head(&nr_list, *pos);
1265}
1266
1267static void *nr_info_next(struct seq_file *seq, void *v, loff_t *pos)
1268{
1269 return seq_hlist_next(v, &nr_list, pos);
1270}
1271
1272static void nr_info_stop(struct seq_file *seq, void *v)
1273{
1274 spin_unlock_bh(&nr_list_lock);
1275}
1276
1277static int nr_info_show(struct seq_file *seq, void *v)
1278{
1279 struct sock *s = sk_entry(v);
1280 struct net_device *dev;
1281 struct nr_sock *nr;
1282 const char *devname;
1283 char buf[11];
1284
1285 if (v == SEQ_START_TOKEN)
1286 seq_puts(seq,
1287"user_addr dest_node src_node dev my your st vs vr va t1 t2 t4 idle n2 wnd Snd-Q Rcv-Q inode\n");
1288
1289 else {
1290
1291 bh_lock_sock(s);
1292 nr = nr_sk(s);
1293
1294 if ((dev = nr->device) == NULL)
1295 devname = "???";
1296 else
1297 devname = dev->name;
1298
1299 seq_printf(seq, "%-9s ", ax2asc(buf, &nr->user_addr));
1300 seq_printf(seq, "%-9s ", ax2asc(buf, &nr->dest_addr));
1301 seq_printf(seq,
1302"%-9s %-3s %02X/%02X %02X/%02X %2d %3d %3d %3d %3lu/%03lu %2lu/%02lu %3lu/%03lu %3lu/%03lu %2d/%02d %3d %5d %5d %ld\n",
1303 ax2asc(buf, &nr->source_addr),
1304 devname,
1305 nr->my_index,
1306 nr->my_id,
1307 nr->your_index,
1308 nr->your_id,
1309 nr->state,
1310 nr->vs,
1311 nr->vr,
1312 nr->va,
1313 ax25_display_timer(&nr->t1timer) / HZ,
1314 nr->t1 / HZ,
1315 ax25_display_timer(&nr->t2timer) / HZ,
1316 nr->t2 / HZ,
1317 ax25_display_timer(&nr->t4timer) / HZ,
1318 nr->t4 / HZ,
1319 ax25_display_timer(&nr->idletimer) / (60 * HZ),
1320 nr->idle / (60 * HZ),
1321 nr->n2count,
1322 nr->n2,
1323 nr->window,
1324 sk_wmem_alloc_get(s),
1325 sk_rmem_alloc_get(s),
1326 s->sk_socket ? SOCK_INODE(s->sk_socket)->i_ino : 0L);
1327
1328 bh_unlock_sock(s);
1329 }
1330 return 0;
1331}
1332
1333static const struct seq_operations nr_info_seqops = {
1334 .start = nr_info_start,
1335 .next = nr_info_next,
1336 .stop = nr_info_stop,
1337 .show = nr_info_show,
1338};
1339
1340static int nr_info_open(struct inode *inode, struct file *file)
1341{
1342 return seq_open(file, &nr_info_seqops);
1343}
1344
1345static const struct file_operations nr_info_fops = {
1346 .owner = THIS_MODULE,
1347 .open = nr_info_open,
1348 .read = seq_read,
1349 .llseek = seq_lseek,
1350 .release = seq_release,
1351};
1352#endif /* CONFIG_PROC_FS */
1353
1354static const struct net_proto_family nr_family_ops = {
1355 .family = PF_NETROM,
1356 .create = nr_create,
1357 .owner = THIS_MODULE,
1358};
1359
1360static const struct proto_ops nr_proto_ops = {
1361 .family = PF_NETROM,
1362 .owner = THIS_MODULE,
1363 .release = nr_release,
1364 .bind = nr_bind,
1365 .connect = nr_connect,
1366 .socketpair = sock_no_socketpair,
1367 .accept = nr_accept,
1368 .getname = nr_getname,
1369 .poll = datagram_poll,
1370 .ioctl = nr_ioctl,
1371 .listen = nr_listen,
1372 .shutdown = sock_no_shutdown,
1373 .setsockopt = nr_setsockopt,
1374 .getsockopt = nr_getsockopt,
1375 .sendmsg = nr_sendmsg,
1376 .recvmsg = nr_recvmsg,
1377 .mmap = sock_no_mmap,
1378 .sendpage = sock_no_sendpage,
1379};
1380
1381static struct notifier_block nr_dev_notifier = {
1382 .notifier_call = nr_device_event,
1383};
1384
1385static struct net_device **dev_nr;
1386
1387static struct ax25_protocol nr_pid = {
1388 .pid = AX25_P_NETROM,
1389 .func = nr_route_frame
1390};
1391
1392static struct ax25_linkfail nr_linkfail_notifier = {
1393 .func = nr_link_failed,
1394};
1395
1396static int __init nr_proto_init(void)
1397{
1398 int i;
1399 int rc = proto_register(&nr_proto, 0);
1400
1401 if (rc != 0)
1402 goto out;
1403
1404 if (nr_ndevs > 0x7fffffff/sizeof(struct net_device *)) {
1405 printk(KERN_ERR "NET/ROM: nr_proto_init - nr_ndevs parameter to large\n");
1406 return -1;
1407 }
1408
1409 dev_nr = kzalloc(nr_ndevs * sizeof(struct net_device *), GFP_KERNEL);
1410 if (dev_nr == NULL) {
1411 printk(KERN_ERR "NET/ROM: nr_proto_init - unable to allocate device array\n");
1412 return -1;
1413 }
1414
1415 for (i = 0; i < nr_ndevs; i++) {
1416 char name[IFNAMSIZ];
1417 struct net_device *dev;
1418
1419 sprintf(name, "nr%d", i);
1420 dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, nr_setup);
1421 if (!dev) {
1422 printk(KERN_ERR "NET/ROM: nr_proto_init - unable to allocate device structure\n");
1423 goto fail;
1424 }
1425
1426 dev->base_addr = i;
1427 if (register_netdev(dev)) {
1428 printk(KERN_ERR "NET/ROM: nr_proto_init - unable to register network device\n");
1429 free_netdev(dev);
1430 goto fail;
1431 }
1432 nr_set_lockdep_key(dev);
1433 dev_nr[i] = dev;
1434 }
1435
1436 if (sock_register(&nr_family_ops)) {
1437 printk(KERN_ERR "NET/ROM: nr_proto_init - unable to register socket family\n");
1438 goto fail;
1439 }
1440
1441 register_netdevice_notifier(&nr_dev_notifier);
1442
1443 ax25_register_pid(&nr_pid);
1444 ax25_linkfail_register(&nr_linkfail_notifier);
1445
1446#ifdef CONFIG_SYSCTL
1447 nr_register_sysctl();
1448#endif
1449
1450 nr_loopback_init();
1451
1452 proc_create("nr", S_IRUGO, init_net.proc_net, &nr_info_fops);
1453 proc_create("nr_neigh", S_IRUGO, init_net.proc_net, &nr_neigh_fops);
1454 proc_create("nr_nodes", S_IRUGO, init_net.proc_net, &nr_nodes_fops);
1455out:
1456 return rc;
1457fail:
1458 while (--i >= 0) {
1459 unregister_netdev(dev_nr[i]);
1460 free_netdev(dev_nr[i]);
1461 }
1462 kfree(dev_nr);
1463 proto_unregister(&nr_proto);
1464 rc = -1;
1465 goto out;
1466}
1467
1468module_init(nr_proto_init);
1469
1470module_param(nr_ndevs, int, 0);
1471MODULE_PARM_DESC(nr_ndevs, "number of NET/ROM devices");
1472
1473MODULE_AUTHOR("Jonathan Naylor G4KLX <g4klx@g4klx.demon.co.uk>");
1474MODULE_DESCRIPTION("The amateur radio NET/ROM network and transport layer protocol");
1475MODULE_LICENSE("GPL");
1476MODULE_ALIAS_NETPROTO(PF_NETROM);
1477
1478static void __exit nr_exit(void)
1479{
1480 int i;
1481
1482 remove_proc_entry("nr", init_net.proc_net);
1483 remove_proc_entry("nr_neigh", init_net.proc_net);
1484 remove_proc_entry("nr_nodes", init_net.proc_net);
1485 nr_loopback_clear();
1486
1487 nr_rt_free();
1488
1489#ifdef CONFIG_SYSCTL
1490 nr_unregister_sysctl();
1491#endif
1492
1493 ax25_linkfail_release(&nr_linkfail_notifier);
1494 ax25_protocol_release(AX25_P_NETROM);
1495
1496 unregister_netdevice_notifier(&nr_dev_notifier);
1497
1498 sock_unregister(PF_NETROM);
1499
1500 for (i = 0; i < nr_ndevs; i++) {
1501 struct net_device *dev = dev_nr[i];
1502 if (dev) {
1503 unregister_netdev(dev);
1504 free_netdev(dev);
1505 }
1506 }
1507
1508 kfree(dev_nr);
1509 proto_unregister(&nr_proto);
1510}
1511module_exit(nr_exit);
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 Darryl Miles G7LED (dlm@g7led.demon.co.uk)
7 */
8#include <linux/module.h>
9#include <linux/moduleparam.h>
10#include <linux/capability.h>
11#include <linux/errno.h>
12#include <linux/types.h>
13#include <linux/socket.h>
14#include <linux/in.h>
15#include <linux/slab.h>
16#include <linux/kernel.h>
17#include <linux/sched/signal.h>
18#include <linux/timer.h>
19#include <linux/string.h>
20#include <linux/sockios.h>
21#include <linux/net.h>
22#include <linux/stat.h>
23#include <net/ax25.h>
24#include <linux/inet.h>
25#include <linux/netdevice.h>
26#include <linux/if_arp.h>
27#include <linux/skbuff.h>
28#include <net/net_namespace.h>
29#include <net/sock.h>
30#include <linux/uaccess.h>
31#include <linux/fcntl.h>
32#include <linux/termios.h> /* For TIOCINQ/OUTQ */
33#include <linux/mm.h>
34#include <linux/interrupt.h>
35#include <linux/notifier.h>
36#include <net/netrom.h>
37#include <linux/proc_fs.h>
38#include <linux/seq_file.h>
39#include <net/ip.h>
40#include <net/tcp_states.h>
41#include <net/arp.h>
42#include <linux/init.h>
43
44static int nr_ndevs = 4;
45
46int sysctl_netrom_default_path_quality = NR_DEFAULT_QUAL;
47int sysctl_netrom_obsolescence_count_initialiser = NR_DEFAULT_OBS;
48int sysctl_netrom_network_ttl_initialiser = NR_DEFAULT_TTL;
49int sysctl_netrom_transport_timeout = NR_DEFAULT_T1;
50int sysctl_netrom_transport_maximum_tries = NR_DEFAULT_N2;
51int sysctl_netrom_transport_acknowledge_delay = NR_DEFAULT_T2;
52int sysctl_netrom_transport_busy_delay = NR_DEFAULT_T4;
53int sysctl_netrom_transport_requested_window_size = NR_DEFAULT_WINDOW;
54int sysctl_netrom_transport_no_activity_timeout = NR_DEFAULT_IDLE;
55int sysctl_netrom_routing_control = NR_DEFAULT_ROUTING;
56int sysctl_netrom_link_fails_count = NR_DEFAULT_FAILS;
57int sysctl_netrom_reset_circuit = NR_DEFAULT_RESET;
58
59static unsigned short circuit = 0x101;
60
61static HLIST_HEAD(nr_list);
62static DEFINE_SPINLOCK(nr_list_lock);
63
64static const struct proto_ops nr_proto_ops;
65
66/*
67 * NETROM network devices are virtual network devices encapsulating NETROM
68 * frames into AX.25 which will be sent through an AX.25 device, so form a
69 * special "super class" of normal net devices; split their locks off into a
70 * separate class since they always nest.
71 */
72static struct lock_class_key nr_netdev_xmit_lock_key;
73static struct lock_class_key nr_netdev_addr_lock_key;
74
75static void nr_set_lockdep_one(struct net_device *dev,
76 struct netdev_queue *txq,
77 void *_unused)
78{
79 lockdep_set_class(&txq->_xmit_lock, &nr_netdev_xmit_lock_key);
80}
81
82static void nr_set_lockdep_key(struct net_device *dev)
83{
84 lockdep_set_class(&dev->addr_list_lock, &nr_netdev_addr_lock_key);
85 netdev_for_each_tx_queue(dev, nr_set_lockdep_one, NULL);
86}
87
88/*
89 * Socket removal during an interrupt is now safe.
90 */
91static void nr_remove_socket(struct sock *sk)
92{
93 spin_lock_bh(&nr_list_lock);
94 sk_del_node_init(sk);
95 spin_unlock_bh(&nr_list_lock);
96}
97
98/*
99 * Kill all bound sockets on a dropped device.
100 */
101static void nr_kill_by_device(struct net_device *dev)
102{
103 struct sock *s;
104
105 spin_lock_bh(&nr_list_lock);
106 sk_for_each(s, &nr_list)
107 if (nr_sk(s)->device == dev)
108 nr_disconnect(s, ENETUNREACH);
109 spin_unlock_bh(&nr_list_lock);
110}
111
112/*
113 * Handle device status changes.
114 */
115static int nr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
116{
117 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
118
119 if (!net_eq(dev_net(dev), &init_net))
120 return NOTIFY_DONE;
121
122 if (event != NETDEV_DOWN)
123 return NOTIFY_DONE;
124
125 nr_kill_by_device(dev);
126 nr_rt_device_down(dev);
127
128 return NOTIFY_DONE;
129}
130
131/*
132 * Add a socket to the bound sockets list.
133 */
134static void nr_insert_socket(struct sock *sk)
135{
136 spin_lock_bh(&nr_list_lock);
137 sk_add_node(sk, &nr_list);
138 spin_unlock_bh(&nr_list_lock);
139}
140
141/*
142 * Find a socket that wants to accept the Connect Request we just
143 * received.
144 */
145static struct sock *nr_find_listener(ax25_address *addr)
146{
147 struct sock *s;
148
149 spin_lock_bh(&nr_list_lock);
150 sk_for_each(s, &nr_list)
151 if (!ax25cmp(&nr_sk(s)->source_addr, addr) &&
152 s->sk_state == TCP_LISTEN) {
153 sock_hold(s);
154 goto found;
155 }
156 s = NULL;
157found:
158 spin_unlock_bh(&nr_list_lock);
159 return s;
160}
161
162/*
163 * Find a connected NET/ROM socket given my circuit IDs.
164 */
165static struct sock *nr_find_socket(unsigned char index, unsigned char id)
166{
167 struct sock *s;
168
169 spin_lock_bh(&nr_list_lock);
170 sk_for_each(s, &nr_list) {
171 struct nr_sock *nr = nr_sk(s);
172
173 if (nr->my_index == index && nr->my_id == id) {
174 sock_hold(s);
175 goto found;
176 }
177 }
178 s = NULL;
179found:
180 spin_unlock_bh(&nr_list_lock);
181 return s;
182}
183
184/*
185 * Find a connected NET/ROM socket given their circuit IDs.
186 */
187static struct sock *nr_find_peer(unsigned char index, unsigned char id,
188 ax25_address *dest)
189{
190 struct sock *s;
191
192 spin_lock_bh(&nr_list_lock);
193 sk_for_each(s, &nr_list) {
194 struct nr_sock *nr = nr_sk(s);
195
196 if (nr->your_index == index && nr->your_id == id &&
197 !ax25cmp(&nr->dest_addr, dest)) {
198 sock_hold(s);
199 goto found;
200 }
201 }
202 s = NULL;
203found:
204 spin_unlock_bh(&nr_list_lock);
205 return s;
206}
207
208/*
209 * Find next free circuit ID.
210 */
211static unsigned short nr_find_next_circuit(void)
212{
213 unsigned short id = circuit;
214 unsigned char i, j;
215 struct sock *sk;
216
217 for (;;) {
218 i = id / 256;
219 j = id % 256;
220
221 if (i != 0 && j != 0) {
222 if ((sk=nr_find_socket(i, j)) == NULL)
223 break;
224 sock_put(sk);
225 }
226
227 id++;
228 }
229
230 return id;
231}
232
233/*
234 * Deferred destroy.
235 */
236void nr_destroy_socket(struct sock *);
237
238/*
239 * Handler for deferred kills.
240 */
241static void nr_destroy_timer(struct timer_list *t)
242{
243 struct sock *sk = from_timer(sk, t, sk_timer);
244 bh_lock_sock(sk);
245 sock_hold(sk);
246 nr_destroy_socket(sk);
247 bh_unlock_sock(sk);
248 sock_put(sk);
249}
250
251/*
252 * This is called from user mode and the timers. Thus it protects itself
253 * against interrupt users but doesn't worry about being called during
254 * work. Once it is removed from the queue no interrupt or bottom half
255 * will touch it and we are (fairly 8-) ) safe.
256 */
257void nr_destroy_socket(struct sock *sk)
258{
259 struct sk_buff *skb;
260
261 nr_remove_socket(sk);
262
263 nr_stop_heartbeat(sk);
264 nr_stop_t1timer(sk);
265 nr_stop_t2timer(sk);
266 nr_stop_t4timer(sk);
267 nr_stop_idletimer(sk);
268
269 nr_clear_queues(sk); /* Flush the queues */
270
271 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
272 if (skb->sk != sk) { /* A pending connection */
273 /* Queue the unaccepted socket for death */
274 sock_set_flag(skb->sk, SOCK_DEAD);
275 nr_start_heartbeat(skb->sk);
276 nr_sk(skb->sk)->state = NR_STATE_0;
277 }
278
279 kfree_skb(skb);
280 }
281
282 if (sk_has_allocations(sk)) {
283 /* Defer: outstanding buffers */
284 sk->sk_timer.function = nr_destroy_timer;
285 sk->sk_timer.expires = jiffies + 2 * HZ;
286 add_timer(&sk->sk_timer);
287 } else
288 sock_put(sk);
289}
290
291/*
292 * Handling for system calls applied via the various interfaces to a
293 * NET/ROM socket object.
294 */
295
296static int nr_setsockopt(struct socket *sock, int level, int optname,
297 sockptr_t optval, unsigned int optlen)
298{
299 struct sock *sk = sock->sk;
300 struct nr_sock *nr = nr_sk(sk);
301 unsigned int opt;
302
303 if (level != SOL_NETROM)
304 return -ENOPROTOOPT;
305
306 if (optlen < sizeof(unsigned int))
307 return -EINVAL;
308
309 if (copy_from_sockptr(&opt, optval, sizeof(opt)))
310 return -EFAULT;
311
312 switch (optname) {
313 case NETROM_T1:
314 if (opt < 1 || opt > UINT_MAX / HZ)
315 return -EINVAL;
316 nr->t1 = opt * HZ;
317 return 0;
318
319 case NETROM_T2:
320 if (opt < 1 || opt > UINT_MAX / HZ)
321 return -EINVAL;
322 nr->t2 = opt * HZ;
323 return 0;
324
325 case NETROM_N2:
326 if (opt < 1 || opt > 31)
327 return -EINVAL;
328 nr->n2 = opt;
329 return 0;
330
331 case NETROM_T4:
332 if (opt < 1 || opt > UINT_MAX / HZ)
333 return -EINVAL;
334 nr->t4 = opt * HZ;
335 return 0;
336
337 case NETROM_IDLE:
338 if (opt > UINT_MAX / (60 * HZ))
339 return -EINVAL;
340 nr->idle = opt * 60 * HZ;
341 return 0;
342
343 default:
344 return -ENOPROTOOPT;
345 }
346}
347
348static int nr_getsockopt(struct socket *sock, int level, int optname,
349 char __user *optval, int __user *optlen)
350{
351 struct sock *sk = sock->sk;
352 struct nr_sock *nr = nr_sk(sk);
353 int val = 0;
354 int len;
355
356 if (level != SOL_NETROM)
357 return -ENOPROTOOPT;
358
359 if (get_user(len, optlen))
360 return -EFAULT;
361
362 if (len < 0)
363 return -EINVAL;
364
365 switch (optname) {
366 case NETROM_T1:
367 val = nr->t1 / HZ;
368 break;
369
370 case NETROM_T2:
371 val = nr->t2 / HZ;
372 break;
373
374 case NETROM_N2:
375 val = nr->n2;
376 break;
377
378 case NETROM_T4:
379 val = nr->t4 / HZ;
380 break;
381
382 case NETROM_IDLE:
383 val = nr->idle / (60 * HZ);
384 break;
385
386 default:
387 return -ENOPROTOOPT;
388 }
389
390 len = min_t(unsigned int, len, sizeof(int));
391
392 if (put_user(len, optlen))
393 return -EFAULT;
394
395 return copy_to_user(optval, &val, len) ? -EFAULT : 0;
396}
397
398static int nr_listen(struct socket *sock, int backlog)
399{
400 struct sock *sk = sock->sk;
401
402 lock_sock(sk);
403 if (sock->state != SS_UNCONNECTED) {
404 release_sock(sk);
405 return -EINVAL;
406 }
407
408 if (sk->sk_state != TCP_LISTEN) {
409 memset(&nr_sk(sk)->user_addr, 0, AX25_ADDR_LEN);
410 sk->sk_max_ack_backlog = backlog;
411 sk->sk_state = TCP_LISTEN;
412 release_sock(sk);
413 return 0;
414 }
415 release_sock(sk);
416
417 return -EOPNOTSUPP;
418}
419
420static struct proto nr_proto = {
421 .name = "NETROM",
422 .owner = THIS_MODULE,
423 .obj_size = sizeof(struct nr_sock),
424};
425
426static int nr_create(struct net *net, struct socket *sock, int protocol,
427 int kern)
428{
429 struct sock *sk;
430 struct nr_sock *nr;
431
432 if (!net_eq(net, &init_net))
433 return -EAFNOSUPPORT;
434
435 if (sock->type != SOCK_SEQPACKET || protocol != 0)
436 return -ESOCKTNOSUPPORT;
437
438 sk = sk_alloc(net, PF_NETROM, GFP_ATOMIC, &nr_proto, kern);
439 if (sk == NULL)
440 return -ENOMEM;
441
442 nr = nr_sk(sk);
443
444 sock_init_data(sock, sk);
445
446 sock->ops = &nr_proto_ops;
447 sk->sk_protocol = protocol;
448
449 skb_queue_head_init(&nr->ack_queue);
450 skb_queue_head_init(&nr->reseq_queue);
451 skb_queue_head_init(&nr->frag_queue);
452
453 nr_init_timers(sk);
454
455 nr->t1 =
456 msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_timeout));
457 nr->t2 =
458 msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_acknowledge_delay));
459 nr->n2 =
460 msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_maximum_tries));
461 nr->t4 =
462 msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_busy_delay));
463 nr->idle =
464 msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_no_activity_timeout));
465 nr->window = READ_ONCE(sysctl_netrom_transport_requested_window_size);
466
467 nr->bpqext = 1;
468 nr->state = NR_STATE_0;
469
470 return 0;
471}
472
473static struct sock *nr_make_new(struct sock *osk)
474{
475 struct sock *sk;
476 struct nr_sock *nr, *onr;
477
478 if (osk->sk_type != SOCK_SEQPACKET)
479 return NULL;
480
481 sk = sk_alloc(sock_net(osk), PF_NETROM, GFP_ATOMIC, osk->sk_prot, 0);
482 if (sk == NULL)
483 return NULL;
484
485 nr = nr_sk(sk);
486
487 sock_init_data(NULL, sk);
488
489 sk->sk_type = osk->sk_type;
490 sk->sk_priority = READ_ONCE(osk->sk_priority);
491 sk->sk_protocol = osk->sk_protocol;
492 sk->sk_rcvbuf = osk->sk_rcvbuf;
493 sk->sk_sndbuf = osk->sk_sndbuf;
494 sk->sk_state = TCP_ESTABLISHED;
495 sock_copy_flags(sk, osk);
496
497 skb_queue_head_init(&nr->ack_queue);
498 skb_queue_head_init(&nr->reseq_queue);
499 skb_queue_head_init(&nr->frag_queue);
500
501 nr_init_timers(sk);
502
503 onr = nr_sk(osk);
504
505 nr->t1 = onr->t1;
506 nr->t2 = onr->t2;
507 nr->n2 = onr->n2;
508 nr->t4 = onr->t4;
509 nr->idle = onr->idle;
510 nr->window = onr->window;
511
512 nr->device = onr->device;
513 nr->bpqext = onr->bpqext;
514
515 return sk;
516}
517
518static int nr_release(struct socket *sock)
519{
520 struct sock *sk = sock->sk;
521 struct nr_sock *nr;
522
523 if (sk == NULL) return 0;
524
525 sock_hold(sk);
526 sock_orphan(sk);
527 lock_sock(sk);
528 nr = nr_sk(sk);
529
530 switch (nr->state) {
531 case NR_STATE_0:
532 case NR_STATE_1:
533 case NR_STATE_2:
534 nr_disconnect(sk, 0);
535 nr_destroy_socket(sk);
536 break;
537
538 case NR_STATE_3:
539 nr_clear_queues(sk);
540 nr->n2count = 0;
541 nr_write_internal(sk, NR_DISCREQ);
542 nr_start_t1timer(sk);
543 nr_stop_t2timer(sk);
544 nr_stop_t4timer(sk);
545 nr_stop_idletimer(sk);
546 nr->state = NR_STATE_2;
547 sk->sk_state = TCP_CLOSE;
548 sk->sk_shutdown |= SEND_SHUTDOWN;
549 sk->sk_state_change(sk);
550 sock_set_flag(sk, SOCK_DESTROY);
551 break;
552
553 default:
554 break;
555 }
556
557 sock->sk = NULL;
558 release_sock(sk);
559 sock_put(sk);
560
561 return 0;
562}
563
564static int nr_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
565{
566 struct sock *sk = sock->sk;
567 struct nr_sock *nr = nr_sk(sk);
568 struct full_sockaddr_ax25 *addr = (struct full_sockaddr_ax25 *)uaddr;
569 struct net_device *dev;
570 ax25_uid_assoc *user;
571 ax25_address *source;
572
573 lock_sock(sk);
574 if (!sock_flag(sk, SOCK_ZAPPED)) {
575 release_sock(sk);
576 return -EINVAL;
577 }
578 if (addr_len < sizeof(struct sockaddr_ax25) || addr_len > sizeof(struct full_sockaddr_ax25)) {
579 release_sock(sk);
580 return -EINVAL;
581 }
582 if (addr_len < (addr->fsa_ax25.sax25_ndigis * sizeof(ax25_address) + sizeof(struct sockaddr_ax25))) {
583 release_sock(sk);
584 return -EINVAL;
585 }
586 if (addr->fsa_ax25.sax25_family != AF_NETROM) {
587 release_sock(sk);
588 return -EINVAL;
589 }
590 if ((dev = nr_dev_get(&addr->fsa_ax25.sax25_call)) == NULL) {
591 release_sock(sk);
592 return -EADDRNOTAVAIL;
593 }
594
595 /*
596 * Only the super user can set an arbitrary user callsign.
597 */
598 if (addr->fsa_ax25.sax25_ndigis == 1) {
599 if (!capable(CAP_NET_BIND_SERVICE)) {
600 dev_put(dev);
601 release_sock(sk);
602 return -EPERM;
603 }
604 nr->user_addr = addr->fsa_digipeater[0];
605 nr->source_addr = addr->fsa_ax25.sax25_call;
606 } else {
607 source = &addr->fsa_ax25.sax25_call;
608
609 user = ax25_findbyuid(current_euid());
610 if (user) {
611 nr->user_addr = user->call;
612 ax25_uid_put(user);
613 } else {
614 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
615 release_sock(sk);
616 dev_put(dev);
617 return -EPERM;
618 }
619 nr->user_addr = *source;
620 }
621
622 nr->source_addr = *source;
623 }
624
625 nr->device = dev;
626 nr_insert_socket(sk);
627
628 sock_reset_flag(sk, SOCK_ZAPPED);
629 dev_put(dev);
630 release_sock(sk);
631
632 return 0;
633}
634
635static int nr_connect(struct socket *sock, struct sockaddr *uaddr,
636 int addr_len, int flags)
637{
638 struct sock *sk = sock->sk;
639 struct nr_sock *nr = nr_sk(sk);
640 struct sockaddr_ax25 *addr = (struct sockaddr_ax25 *)uaddr;
641 const ax25_address *source = NULL;
642 ax25_uid_assoc *user;
643 struct net_device *dev;
644 int err = 0;
645
646 lock_sock(sk);
647 if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
648 sock->state = SS_CONNECTED;
649 goto out_release; /* Connect completed during a ERESTARTSYS event */
650 }
651
652 if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
653 sock->state = SS_UNCONNECTED;
654 err = -ECONNREFUSED;
655 goto out_release;
656 }
657
658 if (sk->sk_state == TCP_ESTABLISHED) {
659 err = -EISCONN; /* No reconnect on a seqpacket socket */
660 goto out_release;
661 }
662
663 if (sock->state == SS_CONNECTING) {
664 err = -EALREADY;
665 goto out_release;
666 }
667
668 sk->sk_state = TCP_CLOSE;
669 sock->state = SS_UNCONNECTED;
670
671 if (addr_len != sizeof(struct sockaddr_ax25) && addr_len != sizeof(struct full_sockaddr_ax25)) {
672 err = -EINVAL;
673 goto out_release;
674 }
675 if (addr->sax25_family != AF_NETROM) {
676 err = -EINVAL;
677 goto out_release;
678 }
679 if (sock_flag(sk, SOCK_ZAPPED)) { /* Must bind first - autobinding in this may or may not work */
680 sock_reset_flag(sk, SOCK_ZAPPED);
681
682 if ((dev = nr_dev_first()) == NULL) {
683 err = -ENETUNREACH;
684 goto out_release;
685 }
686 source = (const ax25_address *)dev->dev_addr;
687
688 user = ax25_findbyuid(current_euid());
689 if (user) {
690 nr->user_addr = user->call;
691 ax25_uid_put(user);
692 } else {
693 if (ax25_uid_policy && !capable(CAP_NET_ADMIN)) {
694 dev_put(dev);
695 err = -EPERM;
696 goto out_release;
697 }
698 nr->user_addr = *source;
699 }
700
701 nr->source_addr = *source;
702 nr->device = dev;
703
704 dev_put(dev);
705 nr_insert_socket(sk); /* Finish the bind */
706 }
707
708 nr->dest_addr = addr->sax25_call;
709
710 release_sock(sk);
711 circuit = nr_find_next_circuit();
712 lock_sock(sk);
713
714 nr->my_index = circuit / 256;
715 nr->my_id = circuit % 256;
716
717 circuit++;
718
719 /* Move to connecting socket, start sending Connect Requests */
720 sock->state = SS_CONNECTING;
721 sk->sk_state = TCP_SYN_SENT;
722
723 nr_establish_data_link(sk);
724
725 nr->state = NR_STATE_1;
726
727 nr_start_heartbeat(sk);
728
729 /* Now the loop */
730 if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK)) {
731 err = -EINPROGRESS;
732 goto out_release;
733 }
734
735 /*
736 * A Connect Ack with Choke or timeout or failed routing will go to
737 * closed.
738 */
739 if (sk->sk_state == TCP_SYN_SENT) {
740 DEFINE_WAIT(wait);
741
742 for (;;) {
743 prepare_to_wait(sk_sleep(sk), &wait,
744 TASK_INTERRUPTIBLE);
745 if (sk->sk_state != TCP_SYN_SENT)
746 break;
747 if (!signal_pending(current)) {
748 release_sock(sk);
749 schedule();
750 lock_sock(sk);
751 continue;
752 }
753 err = -ERESTARTSYS;
754 break;
755 }
756 finish_wait(sk_sleep(sk), &wait);
757 if (err)
758 goto out_release;
759 }
760
761 if (sk->sk_state != TCP_ESTABLISHED) {
762 sock->state = SS_UNCONNECTED;
763 err = sock_error(sk); /* Always set at this point */
764 goto out_release;
765 }
766
767 sock->state = SS_CONNECTED;
768
769out_release:
770 release_sock(sk);
771
772 return err;
773}
774
775static int nr_accept(struct socket *sock, struct socket *newsock, int flags,
776 bool kern)
777{
778 struct sk_buff *skb;
779 struct sock *newsk;
780 DEFINE_WAIT(wait);
781 struct sock *sk;
782 int err = 0;
783
784 if ((sk = sock->sk) == NULL)
785 return -EINVAL;
786
787 lock_sock(sk);
788 if (sk->sk_type != SOCK_SEQPACKET) {
789 err = -EOPNOTSUPP;
790 goto out_release;
791 }
792
793 if (sk->sk_state != TCP_LISTEN) {
794 err = -EINVAL;
795 goto out_release;
796 }
797
798 /*
799 * The write queue this time is holding sockets ready to use
800 * hooked into the SABM we saved
801 */
802 for (;;) {
803 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
804 skb = skb_dequeue(&sk->sk_receive_queue);
805 if (skb)
806 break;
807
808 if (flags & O_NONBLOCK) {
809 err = -EWOULDBLOCK;
810 break;
811 }
812 if (!signal_pending(current)) {
813 release_sock(sk);
814 schedule();
815 lock_sock(sk);
816 continue;
817 }
818 err = -ERESTARTSYS;
819 break;
820 }
821 finish_wait(sk_sleep(sk), &wait);
822 if (err)
823 goto out_release;
824
825 newsk = skb->sk;
826 sock_graft(newsk, newsock);
827
828 /* Now attach up the new socket */
829 kfree_skb(skb);
830 sk_acceptq_removed(sk);
831
832out_release:
833 release_sock(sk);
834
835 return err;
836}
837
838static int nr_getname(struct socket *sock, struct sockaddr *uaddr,
839 int peer)
840{
841 struct full_sockaddr_ax25 *sax = (struct full_sockaddr_ax25 *)uaddr;
842 struct sock *sk = sock->sk;
843 struct nr_sock *nr = nr_sk(sk);
844 int uaddr_len;
845
846 memset(&sax->fsa_ax25, 0, sizeof(struct sockaddr_ax25));
847
848 lock_sock(sk);
849 if (peer != 0) {
850 if (sk->sk_state != TCP_ESTABLISHED) {
851 release_sock(sk);
852 return -ENOTCONN;
853 }
854 sax->fsa_ax25.sax25_family = AF_NETROM;
855 sax->fsa_ax25.sax25_ndigis = 1;
856 sax->fsa_ax25.sax25_call = nr->user_addr;
857 memset(sax->fsa_digipeater, 0, sizeof(sax->fsa_digipeater));
858 sax->fsa_digipeater[0] = nr->dest_addr;
859 uaddr_len = sizeof(struct full_sockaddr_ax25);
860 } else {
861 sax->fsa_ax25.sax25_family = AF_NETROM;
862 sax->fsa_ax25.sax25_ndigis = 0;
863 sax->fsa_ax25.sax25_call = nr->source_addr;
864 uaddr_len = sizeof(struct sockaddr_ax25);
865 }
866 release_sock(sk);
867
868 return uaddr_len;
869}
870
871int nr_rx_frame(struct sk_buff *skb, struct net_device *dev)
872{
873 struct sock *sk;
874 struct sock *make;
875 struct nr_sock *nr_make;
876 ax25_address *src, *dest, *user;
877 unsigned short circuit_index, circuit_id;
878 unsigned short peer_circuit_index, peer_circuit_id;
879 unsigned short frametype, flags, window, timeout;
880 int ret;
881
882 skb_orphan(skb);
883
884 /*
885 * skb->data points to the netrom frame start
886 */
887
888 src = (ax25_address *)(skb->data + 0);
889 dest = (ax25_address *)(skb->data + 7);
890
891 circuit_index = skb->data[15];
892 circuit_id = skb->data[16];
893 peer_circuit_index = skb->data[17];
894 peer_circuit_id = skb->data[18];
895 frametype = skb->data[19] & 0x0F;
896 flags = skb->data[19] & 0xF0;
897
898 /*
899 * Check for an incoming IP over NET/ROM frame.
900 */
901 if (frametype == NR_PROTOEXT &&
902 circuit_index == NR_PROTO_IP && circuit_id == NR_PROTO_IP) {
903 skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
904 skb_reset_transport_header(skb);
905
906 return nr_rx_ip(skb, dev);
907 }
908
909 /*
910 * Find an existing socket connection, based on circuit ID, if it's
911 * a Connect Request base it on their circuit ID.
912 *
913 * Circuit ID 0/0 is not valid but it could still be a "reset" for a
914 * circuit that no longer exists at the other end ...
915 */
916
917 sk = NULL;
918
919 if (circuit_index == 0 && circuit_id == 0) {
920 if (frametype == NR_CONNACK && flags == NR_CHOKE_FLAG)
921 sk = nr_find_peer(peer_circuit_index, peer_circuit_id, src);
922 } else {
923 if (frametype == NR_CONNREQ)
924 sk = nr_find_peer(circuit_index, circuit_id, src);
925 else
926 sk = nr_find_socket(circuit_index, circuit_id);
927 }
928
929 if (sk != NULL) {
930 bh_lock_sock(sk);
931 skb_reset_transport_header(skb);
932
933 if (frametype == NR_CONNACK && skb->len == 22)
934 nr_sk(sk)->bpqext = 1;
935 else
936 nr_sk(sk)->bpqext = 0;
937
938 ret = nr_process_rx_frame(sk, skb);
939 bh_unlock_sock(sk);
940 sock_put(sk);
941 return ret;
942 }
943
944 /*
945 * Now it should be a CONNREQ.
946 */
947 if (frametype != NR_CONNREQ) {
948 /*
949 * Here it would be nice to be able to send a reset but
950 * NET/ROM doesn't have one. We've tried to extend the protocol
951 * by sending NR_CONNACK | NR_CHOKE_FLAGS replies but that
952 * apparently kills BPQ boxes... :-(
953 * So now we try to follow the established behaviour of
954 * G8PZT's Xrouter which is sending packets with command type 7
955 * as an extension of the protocol.
956 */
957 if (READ_ONCE(sysctl_netrom_reset_circuit) &&
958 (frametype != NR_RESET || flags != 0))
959 nr_transmit_reset(skb, 1);
960
961 return 0;
962 }
963
964 sk = nr_find_listener(dest);
965
966 user = (ax25_address *)(skb->data + 21);
967
968 if (sk == NULL || sk_acceptq_is_full(sk) ||
969 (make = nr_make_new(sk)) == NULL) {
970 nr_transmit_refusal(skb, 0);
971 if (sk)
972 sock_put(sk);
973 return 0;
974 }
975
976 bh_lock_sock(sk);
977
978 window = skb->data[20];
979
980 sock_hold(make);
981 skb->sk = make;
982 skb->destructor = sock_efree;
983 make->sk_state = TCP_ESTABLISHED;
984
985 /* Fill in his circuit details */
986 nr_make = nr_sk(make);
987 nr_make->source_addr = *dest;
988 nr_make->dest_addr = *src;
989 nr_make->user_addr = *user;
990
991 nr_make->your_index = circuit_index;
992 nr_make->your_id = circuit_id;
993
994 bh_unlock_sock(sk);
995 circuit = nr_find_next_circuit();
996 bh_lock_sock(sk);
997
998 nr_make->my_index = circuit / 256;
999 nr_make->my_id = circuit % 256;
1000
1001 circuit++;
1002
1003 /* Window negotiation */
1004 if (window < nr_make->window)
1005 nr_make->window = window;
1006
1007 /* L4 timeout negotiation */
1008 if (skb->len == 37) {
1009 timeout = skb->data[36] * 256 + skb->data[35];
1010 if (timeout * HZ < nr_make->t1)
1011 nr_make->t1 = timeout * HZ;
1012 nr_make->bpqext = 1;
1013 } else {
1014 nr_make->bpqext = 0;
1015 }
1016
1017 nr_write_internal(make, NR_CONNACK);
1018
1019 nr_make->condition = 0x00;
1020 nr_make->vs = 0;
1021 nr_make->va = 0;
1022 nr_make->vr = 0;
1023 nr_make->vl = 0;
1024 nr_make->state = NR_STATE_3;
1025 sk_acceptq_added(sk);
1026 skb_queue_head(&sk->sk_receive_queue, skb);
1027
1028 if (!sock_flag(sk, SOCK_DEAD))
1029 sk->sk_data_ready(sk);
1030
1031 bh_unlock_sock(sk);
1032 sock_put(sk);
1033
1034 nr_insert_socket(make);
1035
1036 nr_start_heartbeat(make);
1037 nr_start_idletimer(make);
1038
1039 return 1;
1040}
1041
1042static int nr_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1043{
1044 struct sock *sk = sock->sk;
1045 struct nr_sock *nr = nr_sk(sk);
1046 DECLARE_SOCKADDR(struct sockaddr_ax25 *, usax, msg->msg_name);
1047 int err;
1048 struct sockaddr_ax25 sax;
1049 struct sk_buff *skb;
1050 unsigned char *asmptr;
1051 int size;
1052
1053 if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_CMSG_COMPAT))
1054 return -EINVAL;
1055
1056 lock_sock(sk);
1057 if (sock_flag(sk, SOCK_ZAPPED)) {
1058 err = -EADDRNOTAVAIL;
1059 goto out;
1060 }
1061
1062 if (sk->sk_shutdown & SEND_SHUTDOWN) {
1063 send_sig(SIGPIPE, current, 0);
1064 err = -EPIPE;
1065 goto out;
1066 }
1067
1068 if (nr->device == NULL) {
1069 err = -ENETUNREACH;
1070 goto out;
1071 }
1072
1073 if (usax) {
1074 if (msg->msg_namelen < sizeof(sax)) {
1075 err = -EINVAL;
1076 goto out;
1077 }
1078 sax = *usax;
1079 if (ax25cmp(&nr->dest_addr, &sax.sax25_call) != 0) {
1080 err = -EISCONN;
1081 goto out;
1082 }
1083 if (sax.sax25_family != AF_NETROM) {
1084 err = -EINVAL;
1085 goto out;
1086 }
1087 } else {
1088 if (sk->sk_state != TCP_ESTABLISHED) {
1089 err = -ENOTCONN;
1090 goto out;
1091 }
1092 sax.sax25_family = AF_NETROM;
1093 sax.sax25_call = nr->dest_addr;
1094 }
1095
1096 /* Build a packet - the conventional user limit is 236 bytes. We can
1097 do ludicrously large NetROM frames but must not overflow */
1098 if (len > 65536) {
1099 err = -EMSGSIZE;
1100 goto out;
1101 }
1102
1103 size = len + NR_NETWORK_LEN + NR_TRANSPORT_LEN;
1104
1105 if ((skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT, &err)) == NULL)
1106 goto out;
1107
1108 skb_reserve(skb, size - len);
1109 skb_reset_transport_header(skb);
1110
1111 /*
1112 * Push down the NET/ROM header
1113 */
1114
1115 asmptr = skb_push(skb, NR_TRANSPORT_LEN);
1116
1117 /* Build a NET/ROM Transport header */
1118
1119 *asmptr++ = nr->your_index;
1120 *asmptr++ = nr->your_id;
1121 *asmptr++ = 0; /* To be filled in later */
1122 *asmptr++ = 0; /* Ditto */
1123 *asmptr++ = NR_INFO;
1124
1125 /*
1126 * Put the data on the end
1127 */
1128 skb_put(skb, len);
1129
1130 /* User data follows immediately after the NET/ROM transport header */
1131 if (memcpy_from_msg(skb_transport_header(skb), msg, len)) {
1132 kfree_skb(skb);
1133 err = -EFAULT;
1134 goto out;
1135 }
1136
1137 if (sk->sk_state != TCP_ESTABLISHED) {
1138 kfree_skb(skb);
1139 err = -ENOTCONN;
1140 goto out;
1141 }
1142
1143 nr_output(sk, skb); /* Shove it onto the queue */
1144
1145 err = len;
1146out:
1147 release_sock(sk);
1148 return err;
1149}
1150
1151static int nr_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1152 int flags)
1153{
1154 struct sock *sk = sock->sk;
1155 DECLARE_SOCKADDR(struct sockaddr_ax25 *, sax, msg->msg_name);
1156 size_t copied;
1157 struct sk_buff *skb;
1158 int er;
1159
1160 /*
1161 * This works for seqpacket too. The receiver has ordered the queue for
1162 * us! We do one quick check first though
1163 */
1164
1165 lock_sock(sk);
1166 if (sk->sk_state != TCP_ESTABLISHED) {
1167 release_sock(sk);
1168 return -ENOTCONN;
1169 }
1170
1171 /* Now we can treat all alike */
1172 skb = skb_recv_datagram(sk, flags, &er);
1173 if (!skb) {
1174 release_sock(sk);
1175 return er;
1176 }
1177
1178 skb_reset_transport_header(skb);
1179 copied = skb->len;
1180
1181 if (copied > size) {
1182 copied = size;
1183 msg->msg_flags |= MSG_TRUNC;
1184 }
1185
1186 er = skb_copy_datagram_msg(skb, 0, msg, copied);
1187 if (er < 0) {
1188 skb_free_datagram(sk, skb);
1189 release_sock(sk);
1190 return er;
1191 }
1192
1193 if (sax != NULL) {
1194 memset(sax, 0, sizeof(*sax));
1195 sax->sax25_family = AF_NETROM;
1196 skb_copy_from_linear_data_offset(skb, 7, sax->sax25_call.ax25_call,
1197 AX25_ADDR_LEN);
1198 msg->msg_namelen = sizeof(*sax);
1199 }
1200
1201 skb_free_datagram(sk, skb);
1202
1203 release_sock(sk);
1204 return copied;
1205}
1206
1207
1208static int nr_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1209{
1210 struct sock *sk = sock->sk;
1211 void __user *argp = (void __user *)arg;
1212
1213 switch (cmd) {
1214 case TIOCOUTQ: {
1215 long amount;
1216
1217 lock_sock(sk);
1218 amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1219 if (amount < 0)
1220 amount = 0;
1221 release_sock(sk);
1222 return put_user(amount, (int __user *)argp);
1223 }
1224
1225 case TIOCINQ: {
1226 struct sk_buff *skb;
1227 long amount = 0L;
1228
1229 lock_sock(sk);
1230 /* These two are safe on a single CPU system as only user tasks fiddle here */
1231 if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1232 amount = skb->len;
1233 release_sock(sk);
1234 return put_user(amount, (int __user *)argp);
1235 }
1236
1237 case SIOCGIFADDR:
1238 case SIOCSIFADDR:
1239 case SIOCGIFDSTADDR:
1240 case SIOCSIFDSTADDR:
1241 case SIOCGIFBRDADDR:
1242 case SIOCSIFBRDADDR:
1243 case SIOCGIFNETMASK:
1244 case SIOCSIFNETMASK:
1245 case SIOCGIFMETRIC:
1246 case SIOCSIFMETRIC:
1247 return -EINVAL;
1248
1249 case SIOCADDRT:
1250 case SIOCDELRT:
1251 case SIOCNRDECOBS:
1252 if (!capable(CAP_NET_ADMIN))
1253 return -EPERM;
1254 return nr_rt_ioctl(cmd, argp);
1255
1256 default:
1257 return -ENOIOCTLCMD;
1258 }
1259
1260 return 0;
1261}
1262
1263#ifdef CONFIG_PROC_FS
1264
1265static void *nr_info_start(struct seq_file *seq, loff_t *pos)
1266 __acquires(&nr_list_lock)
1267{
1268 spin_lock_bh(&nr_list_lock);
1269 return seq_hlist_start_head(&nr_list, *pos);
1270}
1271
1272static void *nr_info_next(struct seq_file *seq, void *v, loff_t *pos)
1273{
1274 return seq_hlist_next(v, &nr_list, pos);
1275}
1276
1277static void nr_info_stop(struct seq_file *seq, void *v)
1278 __releases(&nr_list_lock)
1279{
1280 spin_unlock_bh(&nr_list_lock);
1281}
1282
1283static int nr_info_show(struct seq_file *seq, void *v)
1284{
1285 struct sock *s = sk_entry(v);
1286 struct net_device *dev;
1287 struct nr_sock *nr;
1288 const char *devname;
1289 char buf[11];
1290
1291 if (v == SEQ_START_TOKEN)
1292 seq_puts(seq,
1293"user_addr dest_node src_node dev my your st vs vr va t1 t2 t4 idle n2 wnd Snd-Q Rcv-Q inode\n");
1294
1295 else {
1296
1297 bh_lock_sock(s);
1298 nr = nr_sk(s);
1299
1300 if ((dev = nr->device) == NULL)
1301 devname = "???";
1302 else
1303 devname = dev->name;
1304
1305 seq_printf(seq, "%-9s ", ax2asc(buf, &nr->user_addr));
1306 seq_printf(seq, "%-9s ", ax2asc(buf, &nr->dest_addr));
1307 seq_printf(seq,
1308"%-9s %-3s %02X/%02X %02X/%02X %2d %3d %3d %3d %3lu/%03lu %2lu/%02lu %3lu/%03lu %3lu/%03lu %2d/%02d %3d %5d %5d %ld\n",
1309 ax2asc(buf, &nr->source_addr),
1310 devname,
1311 nr->my_index,
1312 nr->my_id,
1313 nr->your_index,
1314 nr->your_id,
1315 nr->state,
1316 nr->vs,
1317 nr->vr,
1318 nr->va,
1319 ax25_display_timer(&nr->t1timer) / HZ,
1320 nr->t1 / HZ,
1321 ax25_display_timer(&nr->t2timer) / HZ,
1322 nr->t2 / HZ,
1323 ax25_display_timer(&nr->t4timer) / HZ,
1324 nr->t4 / HZ,
1325 ax25_display_timer(&nr->idletimer) / (60 * HZ),
1326 nr->idle / (60 * HZ),
1327 nr->n2count,
1328 nr->n2,
1329 nr->window,
1330 sk_wmem_alloc_get(s),
1331 sk_rmem_alloc_get(s),
1332 s->sk_socket ? SOCK_INODE(s->sk_socket)->i_ino : 0L);
1333
1334 bh_unlock_sock(s);
1335 }
1336 return 0;
1337}
1338
1339static const struct seq_operations nr_info_seqops = {
1340 .start = nr_info_start,
1341 .next = nr_info_next,
1342 .stop = nr_info_stop,
1343 .show = nr_info_show,
1344};
1345#endif /* CONFIG_PROC_FS */
1346
1347static const struct net_proto_family nr_family_ops = {
1348 .family = PF_NETROM,
1349 .create = nr_create,
1350 .owner = THIS_MODULE,
1351};
1352
1353static const struct proto_ops nr_proto_ops = {
1354 .family = PF_NETROM,
1355 .owner = THIS_MODULE,
1356 .release = nr_release,
1357 .bind = nr_bind,
1358 .connect = nr_connect,
1359 .socketpair = sock_no_socketpair,
1360 .accept = nr_accept,
1361 .getname = nr_getname,
1362 .poll = datagram_poll,
1363 .ioctl = nr_ioctl,
1364 .gettstamp = sock_gettstamp,
1365 .listen = nr_listen,
1366 .shutdown = sock_no_shutdown,
1367 .setsockopt = nr_setsockopt,
1368 .getsockopt = nr_getsockopt,
1369 .sendmsg = nr_sendmsg,
1370 .recvmsg = nr_recvmsg,
1371 .mmap = sock_no_mmap,
1372};
1373
1374static struct notifier_block nr_dev_notifier = {
1375 .notifier_call = nr_device_event,
1376};
1377
1378static struct net_device **dev_nr;
1379
1380static struct ax25_protocol nr_pid = {
1381 .pid = AX25_P_NETROM,
1382 .func = nr_route_frame
1383};
1384
1385static struct ax25_linkfail nr_linkfail_notifier = {
1386 .func = nr_link_failed,
1387};
1388
1389static int __init nr_proto_init(void)
1390{
1391 int i;
1392 int rc = proto_register(&nr_proto, 0);
1393
1394 if (rc)
1395 return rc;
1396
1397 if (nr_ndevs > 0x7fffffff/sizeof(struct net_device *)) {
1398 pr_err("NET/ROM: %s - nr_ndevs parameter too large\n",
1399 __func__);
1400 rc = -EINVAL;
1401 goto unregister_proto;
1402 }
1403
1404 dev_nr = kcalloc(nr_ndevs, sizeof(struct net_device *), GFP_KERNEL);
1405 if (!dev_nr) {
1406 pr_err("NET/ROM: %s - unable to allocate device array\n",
1407 __func__);
1408 rc = -ENOMEM;
1409 goto unregister_proto;
1410 }
1411
1412 for (i = 0; i < nr_ndevs; i++) {
1413 char name[IFNAMSIZ];
1414 struct net_device *dev;
1415
1416 sprintf(name, "nr%d", i);
1417 dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, nr_setup);
1418 if (!dev) {
1419 rc = -ENOMEM;
1420 goto fail;
1421 }
1422
1423 dev->base_addr = i;
1424 rc = register_netdev(dev);
1425 if (rc) {
1426 free_netdev(dev);
1427 goto fail;
1428 }
1429 nr_set_lockdep_key(dev);
1430 dev_nr[i] = dev;
1431 }
1432
1433 rc = sock_register(&nr_family_ops);
1434 if (rc)
1435 goto fail;
1436
1437 rc = register_netdevice_notifier(&nr_dev_notifier);
1438 if (rc)
1439 goto out_sock;
1440
1441 ax25_register_pid(&nr_pid);
1442 ax25_linkfail_register(&nr_linkfail_notifier);
1443
1444#ifdef CONFIG_SYSCTL
1445 rc = nr_register_sysctl();
1446 if (rc)
1447 goto out_sysctl;
1448#endif
1449
1450 nr_loopback_init();
1451
1452 rc = -ENOMEM;
1453 if (!proc_create_seq("nr", 0444, init_net.proc_net, &nr_info_seqops))
1454 goto proc_remove1;
1455 if (!proc_create_seq("nr_neigh", 0444, init_net.proc_net,
1456 &nr_neigh_seqops))
1457 goto proc_remove2;
1458 if (!proc_create_seq("nr_nodes", 0444, init_net.proc_net,
1459 &nr_node_seqops))
1460 goto proc_remove3;
1461
1462 return 0;
1463
1464proc_remove3:
1465 remove_proc_entry("nr_neigh", init_net.proc_net);
1466proc_remove2:
1467 remove_proc_entry("nr", init_net.proc_net);
1468proc_remove1:
1469
1470 nr_loopback_clear();
1471 nr_rt_free();
1472
1473#ifdef CONFIG_SYSCTL
1474 nr_unregister_sysctl();
1475out_sysctl:
1476#endif
1477 ax25_linkfail_release(&nr_linkfail_notifier);
1478 ax25_protocol_release(AX25_P_NETROM);
1479 unregister_netdevice_notifier(&nr_dev_notifier);
1480out_sock:
1481 sock_unregister(PF_NETROM);
1482fail:
1483 while (--i >= 0) {
1484 unregister_netdev(dev_nr[i]);
1485 free_netdev(dev_nr[i]);
1486 }
1487 kfree(dev_nr);
1488unregister_proto:
1489 proto_unregister(&nr_proto);
1490 return rc;
1491}
1492
1493module_init(nr_proto_init);
1494
1495module_param(nr_ndevs, int, 0);
1496MODULE_PARM_DESC(nr_ndevs, "number of NET/ROM devices");
1497
1498MODULE_AUTHOR("Jonathan Naylor G4KLX <g4klx@g4klx.demon.co.uk>");
1499MODULE_DESCRIPTION("The amateur radio NET/ROM network and transport layer protocol");
1500MODULE_LICENSE("GPL");
1501MODULE_ALIAS_NETPROTO(PF_NETROM);
1502
1503static void __exit nr_exit(void)
1504{
1505 int i;
1506
1507 remove_proc_entry("nr", init_net.proc_net);
1508 remove_proc_entry("nr_neigh", init_net.proc_net);
1509 remove_proc_entry("nr_nodes", init_net.proc_net);
1510 nr_loopback_clear();
1511
1512 nr_rt_free();
1513
1514#ifdef CONFIG_SYSCTL
1515 nr_unregister_sysctl();
1516#endif
1517
1518 ax25_linkfail_release(&nr_linkfail_notifier);
1519 ax25_protocol_release(AX25_P_NETROM);
1520
1521 unregister_netdevice_notifier(&nr_dev_notifier);
1522
1523 sock_unregister(PF_NETROM);
1524
1525 for (i = 0; i < nr_ndevs; i++) {
1526 struct net_device *dev = dev_nr[i];
1527 if (dev) {
1528 unregister_netdev(dev);
1529 free_netdev(dev);
1530 }
1531 }
1532
1533 kfree(dev_nr);
1534 proto_unregister(&nr_proto);
1535}
1536module_exit(nr_exit);