forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 17
/
af_netrom.c
1536 lines (1267 loc) · 32.6 KB
/
af_netrom.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* Copyright Jonathan Naylor G4KLX ([email protected])
* Copyright Alan Cox GW4PTS ([email protected])
* Copyright Darryl Miles G7LED ([email protected])
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/stat.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/termios.h> /* For TIOCINQ/OUTQ */
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <net/netrom.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <net/ip.h>
#include <net/tcp_states.h>
#include <net/arp.h>
#include <linux/init.h>
static int nr_ndevs = 4;
int sysctl_netrom_default_path_quality = NR_DEFAULT_QUAL;
int sysctl_netrom_obsolescence_count_initialiser = NR_DEFAULT_OBS;
int sysctl_netrom_network_ttl_initialiser = NR_DEFAULT_TTL;
int sysctl_netrom_transport_timeout = NR_DEFAULT_T1;
int sysctl_netrom_transport_maximum_tries = NR_DEFAULT_N2;
int sysctl_netrom_transport_acknowledge_delay = NR_DEFAULT_T2;
int sysctl_netrom_transport_busy_delay = NR_DEFAULT_T4;
int sysctl_netrom_transport_requested_window_size = NR_DEFAULT_WINDOW;
int sysctl_netrom_transport_no_activity_timeout = NR_DEFAULT_IDLE;
int sysctl_netrom_routing_control = NR_DEFAULT_ROUTING;
int sysctl_netrom_link_fails_count = NR_DEFAULT_FAILS;
int sysctl_netrom_reset_circuit = NR_DEFAULT_RESET;
static unsigned short circuit = 0x101;
static HLIST_HEAD(nr_list);
static DEFINE_SPINLOCK(nr_list_lock);
static const struct proto_ops nr_proto_ops;
/*
* NETROM network devices are virtual network devices encapsulating NETROM
* frames into AX.25 which will be sent through an AX.25 device, so form a
* special "super class" of normal net devices; split their locks off into a
* separate class since they always nest.
*/
static struct lock_class_key nr_netdev_xmit_lock_key;
static struct lock_class_key nr_netdev_addr_lock_key;
static void nr_set_lockdep_one(struct net_device *dev,
struct netdev_queue *txq,
void *_unused)
{
lockdep_set_class(&txq->_xmit_lock, &nr_netdev_xmit_lock_key);
}
static void nr_set_lockdep_key(struct net_device *dev)
{
lockdep_set_class(&dev->addr_list_lock, &nr_netdev_addr_lock_key);
netdev_for_each_tx_queue(dev, nr_set_lockdep_one, NULL);
}
/*
* Socket removal during an interrupt is now safe.
*/
static void nr_remove_socket(struct sock *sk)
{
spin_lock_bh(&nr_list_lock);
sk_del_node_init(sk);
spin_unlock_bh(&nr_list_lock);
}
/*
* Kill all bound sockets on a dropped device.
*/
static void nr_kill_by_device(struct net_device *dev)
{
struct sock *s;
spin_lock_bh(&nr_list_lock);
sk_for_each(s, &nr_list)
if (nr_sk(s)->device == dev)
nr_disconnect(s, ENETUNREACH);
spin_unlock_bh(&nr_list_lock);
}
/*
* Handle device status changes.
*/
static int nr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
if (!net_eq(dev_net(dev), &init_net))
return NOTIFY_DONE;
if (event != NETDEV_DOWN)
return NOTIFY_DONE;
nr_kill_by_device(dev);
nr_rt_device_down(dev);
return NOTIFY_DONE;
}
/*
* Add a socket to the bound sockets list.
*/
static void nr_insert_socket(struct sock *sk)
{
spin_lock_bh(&nr_list_lock);
sk_add_node(sk, &nr_list);
spin_unlock_bh(&nr_list_lock);
}
/*
* Find a socket that wants to accept the Connect Request we just
* received.
*/
static struct sock *nr_find_listener(ax25_address *addr)
{
struct sock *s;
spin_lock_bh(&nr_list_lock);
sk_for_each(s, &nr_list)
if (!ax25cmp(&nr_sk(s)->source_addr, addr) &&
s->sk_state == TCP_LISTEN) {
sock_hold(s);
goto found;
}
s = NULL;
found:
spin_unlock_bh(&nr_list_lock);
return s;
}
/*
* Find a connected NET/ROM socket given my circuit IDs.
*/
static struct sock *nr_find_socket(unsigned char index, unsigned char id)
{
struct sock *s;
spin_lock_bh(&nr_list_lock);
sk_for_each(s, &nr_list) {
struct nr_sock *nr = nr_sk(s);
if (nr->my_index == index && nr->my_id == id) {
sock_hold(s);
goto found;
}
}
s = NULL;
found:
spin_unlock_bh(&nr_list_lock);
return s;
}
/*
* Find a connected NET/ROM socket given their circuit IDs.
*/
static struct sock *nr_find_peer(unsigned char index, unsigned char id,
ax25_address *dest)
{
struct sock *s;
spin_lock_bh(&nr_list_lock);
sk_for_each(s, &nr_list) {
struct nr_sock *nr = nr_sk(s);
if (nr->your_index == index && nr->your_id == id &&
!ax25cmp(&nr->dest_addr, dest)) {
sock_hold(s);
goto found;
}
}
s = NULL;
found:
spin_unlock_bh(&nr_list_lock);
return s;
}
/*
* Find next free circuit ID.
*/
static unsigned short nr_find_next_circuit(void)
{
unsigned short id = circuit;
unsigned char i, j;
struct sock *sk;
for (;;) {
i = id / 256;
j = id % 256;
if (i != 0 && j != 0) {
if ((sk=nr_find_socket(i, j)) == NULL)
break;
sock_put(sk);
}
id++;
}
return id;
}
/*
* Deferred destroy.
*/
void nr_destroy_socket(struct sock *);
/*
* Handler for deferred kills.
*/
static void nr_destroy_timer(struct timer_list *t)
{
struct sock *sk = from_timer(sk, t, sk_timer);
bh_lock_sock(sk);
sock_hold(sk);
nr_destroy_socket(sk);
bh_unlock_sock(sk);
sock_put(sk);
}
/*
* This is called from user mode and the timers. Thus it protects itself
* against interrupt users but doesn't worry about being called during
* work. Once it is removed from the queue no interrupt or bottom half
* will touch it and we are (fairly 8-) ) safe.
*/
void nr_destroy_socket(struct sock *sk)
{
struct sk_buff *skb;
nr_remove_socket(sk);
nr_stop_heartbeat(sk);
nr_stop_t1timer(sk);
nr_stop_t2timer(sk);
nr_stop_t4timer(sk);
nr_stop_idletimer(sk);
nr_clear_queues(sk); /* Flush the queues */
while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
if (skb->sk != sk) { /* A pending connection */
/* Queue the unaccepted socket for death */
sock_set_flag(skb->sk, SOCK_DEAD);
nr_start_heartbeat(skb->sk);
nr_sk(skb->sk)->state = NR_STATE_0;
}
kfree_skb(skb);
}
if (sk_has_allocations(sk)) {
/* Defer: outstanding buffers */
sk->sk_timer.function = nr_destroy_timer;
sk->sk_timer.expires = jiffies + 2 * HZ;
add_timer(&sk->sk_timer);
} else
sock_put(sk);
}
/*
* Handling for system calls applied via the various interfaces to a
* NET/ROM socket object.
*/
static int nr_setsockopt(struct socket *sock, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
unsigned int opt;
if (level != SOL_NETROM)
return -ENOPROTOOPT;
if (optlen < sizeof(unsigned int))
return -EINVAL;
if (copy_from_sockptr(&opt, optval, sizeof(opt)))
return -EFAULT;
switch (optname) {
case NETROM_T1:
if (opt < 1 || opt > UINT_MAX / HZ)
return -EINVAL;
nr->t1 = opt * HZ;
return 0;
case NETROM_T2:
if (opt < 1 || opt > UINT_MAX / HZ)
return -EINVAL;
nr->t2 = opt * HZ;
return 0;
case NETROM_N2:
if (opt < 1 || opt > 31)
return -EINVAL;
nr->n2 = opt;
return 0;
case NETROM_T4:
if (opt < 1 || opt > UINT_MAX / HZ)
return -EINVAL;
nr->t4 = opt * HZ;
return 0;
case NETROM_IDLE:
if (opt > UINT_MAX / (60 * HZ))
return -EINVAL;
nr->idle = opt * 60 * HZ;
return 0;
default:
return -ENOPROTOOPT;
}
}
static int nr_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
int val = 0;
int len;
if (level != SOL_NETROM)
return -ENOPROTOOPT;
if (get_user(len, optlen))
return -EFAULT;
if (len < 0)
return -EINVAL;
switch (optname) {
case NETROM_T1:
val = nr->t1 / HZ;
break;
case NETROM_T2:
val = nr->t2 / HZ;
break;
case NETROM_N2:
val = nr->n2;
break;
case NETROM_T4:
val = nr->t4 / HZ;
break;
case NETROM_IDLE:
val = nr->idle / (60 * HZ);
break;
default:
return -ENOPROTOOPT;
}
len = min_t(unsigned int, len, sizeof(int));
if (put_user(len, optlen))
return -EFAULT;
return copy_to_user(optval, &val, len) ? -EFAULT : 0;
}
static int nr_listen(struct socket *sock, int backlog)
{
struct sock *sk = sock->sk;
lock_sock(sk);
if (sock->state != SS_UNCONNECTED) {
release_sock(sk);
return -EINVAL;
}
if (sk->sk_state != TCP_LISTEN) {
memset(&nr_sk(sk)->user_addr, 0, AX25_ADDR_LEN);
sk->sk_max_ack_backlog = backlog;
sk->sk_state = TCP_LISTEN;
release_sock(sk);
return 0;
}
release_sock(sk);
return -EOPNOTSUPP;
}
static struct proto nr_proto = {
.name = "NETROM",
.owner = THIS_MODULE,
.obj_size = sizeof(struct nr_sock),
};
static int nr_create(struct net *net, struct socket *sock, int protocol,
int kern)
{
struct sock *sk;
struct nr_sock *nr;
if (!net_eq(net, &init_net))
return -EAFNOSUPPORT;
if (sock->type != SOCK_SEQPACKET || protocol != 0)
return -ESOCKTNOSUPPORT;
sk = sk_alloc(net, PF_NETROM, GFP_ATOMIC, &nr_proto, kern);
if (sk == NULL)
return -ENOMEM;
nr = nr_sk(sk);
sock_init_data(sock, sk);
sock->ops = &nr_proto_ops;
sk->sk_protocol = protocol;
skb_queue_head_init(&nr->ack_queue);
skb_queue_head_init(&nr->reseq_queue);
skb_queue_head_init(&nr->frag_queue);
nr_init_timers(sk);
nr->t1 =
msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_timeout));
nr->t2 =
msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_acknowledge_delay));
nr->n2 =
msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_maximum_tries));
nr->t4 =
msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_busy_delay));
nr->idle =
msecs_to_jiffies(READ_ONCE(sysctl_netrom_transport_no_activity_timeout));
nr->window = READ_ONCE(sysctl_netrom_transport_requested_window_size);
nr->bpqext = 1;
nr->state = NR_STATE_0;
return 0;
}
static struct sock *nr_make_new(struct sock *osk)
{
struct sock *sk;
struct nr_sock *nr, *onr;
if (osk->sk_type != SOCK_SEQPACKET)
return NULL;
sk = sk_alloc(sock_net(osk), PF_NETROM, GFP_ATOMIC, osk->sk_prot, 0);
if (sk == NULL)
return NULL;
nr = nr_sk(sk);
sock_init_data(NULL, sk);
sk->sk_type = osk->sk_type;
sk->sk_priority = READ_ONCE(osk->sk_priority);
sk->sk_protocol = osk->sk_protocol;
sk->sk_rcvbuf = osk->sk_rcvbuf;
sk->sk_sndbuf = osk->sk_sndbuf;
sk->sk_state = TCP_ESTABLISHED;
sock_copy_flags(sk, osk);
skb_queue_head_init(&nr->ack_queue);
skb_queue_head_init(&nr->reseq_queue);
skb_queue_head_init(&nr->frag_queue);
nr_init_timers(sk);
onr = nr_sk(osk);
nr->t1 = onr->t1;
nr->t2 = onr->t2;
nr->n2 = onr->n2;
nr->t4 = onr->t4;
nr->idle = onr->idle;
nr->window = onr->window;
nr->device = onr->device;
nr->bpqext = onr->bpqext;
return sk;
}
static int nr_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct nr_sock *nr;
if (sk == NULL) return 0;
sock_hold(sk);
sock_orphan(sk);
lock_sock(sk);
nr = nr_sk(sk);
switch (nr->state) {
case NR_STATE_0:
case NR_STATE_1:
case NR_STATE_2:
nr_disconnect(sk, 0);
nr_destroy_socket(sk);
break;
case NR_STATE_3:
nr_clear_queues(sk);
nr->n2count = 0;
nr_write_internal(sk, NR_DISCREQ);
nr_start_t1timer(sk);
nr_stop_t2timer(sk);
nr_stop_t4timer(sk);
nr_stop_idletimer(sk);
nr->state = NR_STATE_2;
sk->sk_state = TCP_CLOSE;
sk->sk_shutdown |= SEND_SHUTDOWN;
sk->sk_state_change(sk);
sock_set_flag(sk, SOCK_DESTROY);
break;
default:
break;
}
sock->sk = NULL;
release_sock(sk);
sock_put(sk);
return 0;
}
static int nr_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
struct full_sockaddr_ax25 *addr = (struct full_sockaddr_ax25 *)uaddr;
struct net_device *dev;
ax25_uid_assoc *user;
ax25_address *source;
lock_sock(sk);
if (!sock_flag(sk, SOCK_ZAPPED)) {
release_sock(sk);
return -EINVAL;
}
if (addr_len < sizeof(struct sockaddr_ax25) || addr_len > sizeof(struct full_sockaddr_ax25)) {
release_sock(sk);
return -EINVAL;
}
if (addr_len < (addr->fsa_ax25.sax25_ndigis * sizeof(ax25_address) + sizeof(struct sockaddr_ax25))) {
release_sock(sk);
return -EINVAL;
}
if (addr->fsa_ax25.sax25_family != AF_NETROM) {
release_sock(sk);
return -EINVAL;
}
if ((dev = nr_dev_get(&addr->fsa_ax25.sax25_call)) == NULL) {
release_sock(sk);
return -EADDRNOTAVAIL;
}
/*
* Only the super user can set an arbitrary user callsign.
*/
if (addr->fsa_ax25.sax25_ndigis == 1) {
if (!capable(CAP_NET_BIND_SERVICE)) {
dev_put(dev);
release_sock(sk);
return -EPERM;
}
nr->user_addr = addr->fsa_digipeater[0];
nr->source_addr = addr->fsa_ax25.sax25_call;
} else {
source = &addr->fsa_ax25.sax25_call;
user = ax25_findbyuid(current_euid());
if (user) {
nr->user_addr = user->call;
ax25_uid_put(user);
} else {
if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
release_sock(sk);
dev_put(dev);
return -EPERM;
}
nr->user_addr = *source;
}
nr->source_addr = *source;
}
nr->device = dev;
nr_insert_socket(sk);
sock_reset_flag(sk, SOCK_ZAPPED);
dev_put(dev);
release_sock(sk);
return 0;
}
static int nr_connect(struct socket *sock, struct sockaddr *uaddr,
int addr_len, int flags)
{
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
struct sockaddr_ax25 *addr = (struct sockaddr_ax25 *)uaddr;
const ax25_address *source = NULL;
ax25_uid_assoc *user;
struct net_device *dev;
int err = 0;
lock_sock(sk);
if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
sock->state = SS_CONNECTED;
goto out_release; /* Connect completed during a ERESTARTSYS event */
}
if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
sock->state = SS_UNCONNECTED;
err = -ECONNREFUSED;
goto out_release;
}
if (sk->sk_state == TCP_ESTABLISHED) {
err = -EISCONN; /* No reconnect on a seqpacket socket */
goto out_release;
}
if (sock->state == SS_CONNECTING) {
err = -EALREADY;
goto out_release;
}
sk->sk_state = TCP_CLOSE;
sock->state = SS_UNCONNECTED;
if (addr_len != sizeof(struct sockaddr_ax25) && addr_len != sizeof(struct full_sockaddr_ax25)) {
err = -EINVAL;
goto out_release;
}
if (addr->sax25_family != AF_NETROM) {
err = -EINVAL;
goto out_release;
}
if (sock_flag(sk, SOCK_ZAPPED)) { /* Must bind first - autobinding in this may or may not work */
sock_reset_flag(sk, SOCK_ZAPPED);
if ((dev = nr_dev_first()) == NULL) {
err = -ENETUNREACH;
goto out_release;
}
source = (const ax25_address *)dev->dev_addr;
user = ax25_findbyuid(current_euid());
if (user) {
nr->user_addr = user->call;
ax25_uid_put(user);
} else {
if (ax25_uid_policy && !capable(CAP_NET_ADMIN)) {
dev_put(dev);
err = -EPERM;
goto out_release;
}
nr->user_addr = *source;
}
nr->source_addr = *source;
nr->device = dev;
dev_put(dev);
nr_insert_socket(sk); /* Finish the bind */
}
nr->dest_addr = addr->sax25_call;
release_sock(sk);
circuit = nr_find_next_circuit();
lock_sock(sk);
nr->my_index = circuit / 256;
nr->my_id = circuit % 256;
circuit++;
/* Move to connecting socket, start sending Connect Requests */
sock->state = SS_CONNECTING;
sk->sk_state = TCP_SYN_SENT;
nr_establish_data_link(sk);
nr->state = NR_STATE_1;
nr_start_heartbeat(sk);
/* Now the loop */
if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK)) {
err = -EINPROGRESS;
goto out_release;
}
/*
* A Connect Ack with Choke or timeout or failed routing will go to
* closed.
*/
if (sk->sk_state == TCP_SYN_SENT) {
DEFINE_WAIT(wait);
for (;;) {
prepare_to_wait(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
if (sk->sk_state != TCP_SYN_SENT)
break;
if (!signal_pending(current)) {
release_sock(sk);
schedule();
lock_sock(sk);
continue;
}
err = -ERESTARTSYS;
break;
}
finish_wait(sk_sleep(sk), &wait);
if (err)
goto out_release;
}
if (sk->sk_state != TCP_ESTABLISHED) {
sock->state = SS_UNCONNECTED;
err = sock_error(sk); /* Always set at this point */
goto out_release;
}
sock->state = SS_CONNECTED;
out_release:
release_sock(sk);
return err;
}
static int nr_accept(struct socket *sock, struct socket *newsock, int flags,
bool kern)
{
struct sk_buff *skb;
struct sock *newsk;
DEFINE_WAIT(wait);
struct sock *sk;
int err = 0;
if ((sk = sock->sk) == NULL)
return -EINVAL;
lock_sock(sk);
if (sk->sk_type != SOCK_SEQPACKET) {
err = -EOPNOTSUPP;
goto out_release;
}
if (sk->sk_state != TCP_LISTEN) {
err = -EINVAL;
goto out_release;
}
/*
* The write queue this time is holding sockets ready to use
* hooked into the SABM we saved
*/
for (;;) {
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
skb = skb_dequeue(&sk->sk_receive_queue);
if (skb)
break;
if (flags & O_NONBLOCK) {
err = -EWOULDBLOCK;
break;
}
if (!signal_pending(current)) {
release_sock(sk);
schedule();
lock_sock(sk);
continue;
}
err = -ERESTARTSYS;
break;
}
finish_wait(sk_sleep(sk), &wait);
if (err)
goto out_release;
newsk = skb->sk;
sock_graft(newsk, newsock);
/* Now attach up the new socket */
kfree_skb(skb);
sk_acceptq_removed(sk);
out_release:
release_sock(sk);
return err;
}
static int nr_getname(struct socket *sock, struct sockaddr *uaddr,
int peer)
{
struct full_sockaddr_ax25 *sax = (struct full_sockaddr_ax25 *)uaddr;
struct sock *sk = sock->sk;
struct nr_sock *nr = nr_sk(sk);
int uaddr_len;
memset(&sax->fsa_ax25, 0, sizeof(struct sockaddr_ax25));
lock_sock(sk);
if (peer != 0) {
if (sk->sk_state != TCP_ESTABLISHED) {
release_sock(sk);
return -ENOTCONN;
}
sax->fsa_ax25.sax25_family = AF_NETROM;
sax->fsa_ax25.sax25_ndigis = 1;
sax->fsa_ax25.sax25_call = nr->user_addr;
memset(sax->fsa_digipeater, 0, sizeof(sax->fsa_digipeater));
sax->fsa_digipeater[0] = nr->dest_addr;
uaddr_len = sizeof(struct full_sockaddr_ax25);
} else {
sax->fsa_ax25.sax25_family = AF_NETROM;
sax->fsa_ax25.sax25_ndigis = 0;
sax->fsa_ax25.sax25_call = nr->source_addr;
uaddr_len = sizeof(struct sockaddr_ax25);
}
release_sock(sk);
return uaddr_len;
}
int nr_rx_frame(struct sk_buff *skb, struct net_device *dev)
{
struct sock *sk;
struct sock *make;
struct nr_sock *nr_make;
ax25_address *src, *dest, *user;
unsigned short circuit_index, circuit_id;
unsigned short peer_circuit_index, peer_circuit_id;
unsigned short frametype, flags, window, timeout;
int ret;
skb_orphan(skb);
/*
* skb->data points to the netrom frame start
*/
src = (ax25_address *)(skb->data + 0);
dest = (ax25_address *)(skb->data + 7);
circuit_index = skb->data[15];
circuit_id = skb->data[16];
peer_circuit_index = skb->data[17];
peer_circuit_id = skb->data[18];
frametype = skb->data[19] & 0x0F;
flags = skb->data[19] & 0xF0;
/*
* Check for an incoming IP over NET/ROM frame.
*/
if (frametype == NR_PROTOEXT &&
circuit_index == NR_PROTO_IP && circuit_id == NR_PROTO_IP) {
skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
skb_reset_transport_header(skb);
return nr_rx_ip(skb, dev);
}
/*
* Find an existing socket connection, based on circuit ID, if it's
* a Connect Request base it on their circuit ID.
*
* Circuit ID 0/0 is not valid but it could still be a "reset" for a
* circuit that no longer exists at the other end ...
*/
sk = NULL;
if (circuit_index == 0 && circuit_id == 0) {
if (frametype == NR_CONNACK && flags == NR_CHOKE_FLAG)
sk = nr_find_peer(peer_circuit_index, peer_circuit_id, src);
} else {
if (frametype == NR_CONNREQ)
sk = nr_find_peer(circuit_index, circuit_id, src);
else
sk = nr_find_socket(circuit_index, circuit_id);
}
if (sk != NULL) {
bh_lock_sock(sk);
skb_reset_transport_header(skb);
if (frametype == NR_CONNACK && skb->len == 22)
nr_sk(sk)->bpqext = 1;
else
nr_sk(sk)->bpqext = 0;
ret = nr_process_rx_frame(sk, skb);
bh_unlock_sock(sk);
sock_put(sk);
return ret;
}
/*
* Now it should be a CONNREQ.
*/
if (frametype != NR_CONNREQ) {
/*
* Here it would be nice to be able to send a reset but
* NET/ROM doesn't have one. We've tried to extend the protocol
* by sending NR_CONNACK | NR_CHOKE_FLAGS replies but that
* apparently kills BPQ boxes... :-(
* So now we try to follow the established behaviour of
* G8PZT's Xrouter which is sending packets with command type 7
* as an extension of the protocol.
*/
if (READ_ONCE(sysctl_netrom_reset_circuit) &&
(frametype != NR_RESET || flags != 0))
nr_transmit_reset(skb, 1);
return 0;
}
sk = nr_find_listener(dest);
user = (ax25_address *)(skb->data + 21);
if (sk == NULL || sk_acceptq_is_full(sk) ||
(make = nr_make_new(sk)) == NULL) {
nr_transmit_refusal(skb, 0);
if (sk)
sock_put(sk);
return 0;
}
bh_lock_sock(sk);
window = skb->data[20];
sock_hold(make);
skb->sk = make;
skb->destructor = sock_efree;
make->sk_state = TCP_ESTABLISHED;
/* Fill in his circuit details */
nr_make = nr_sk(make);
nr_make->source_addr = *dest;
nr_make->dest_addr = *src;
nr_make->user_addr = *user;
nr_make->your_index = circuit_index;
nr_make->your_id = circuit_id;
bh_unlock_sock(sk);
circuit = nr_find_next_circuit();
bh_lock_sock(sk);
nr_make->my_index = circuit / 256;
nr_make->my_id = circuit % 256;