summaryrefslogblamecommitdiff
path: root/net/ax25/af_ax25.c
blob: 000695c48583c07d2005fd9446a58671f8f8455f (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
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
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596














                                                                       
                             






























                                                      
                           







                                
                                             

























































































                                                                              
                                   







                                                                              
                                                             



                                             
                                     













                                                                            
                                   









                                                                  
                                     








































                                                                                                                                   

                            





                                                                         
                                   











                                                                             
                                     















































































































































































                                                                                                                  



















                                                                               








                                                                      


















                                                            
                

                                                









                                       
                                                                

                            











































































































































































































































































































































































































                                                                               
                                 





























































































































                                                                                        

                             

















                                                                                                  








                                                               









                                          
                                 































































































                                                                                                     

                              



























































































































































































































































































































































































































































                                                                                                             
                                                  











































































































                                                                                                         
                                                            



                        
                                                   































































































































                                                                                                         
                                   







































                                                                       
                     










                                                                                                                                        
                                                   
                                          
                                                             


                                                                                 
                                                                  
























































                                                                                                      
                                                

















                                             














                                                                         











































                                                                      
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Copyright (C) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 * Copyright (C) Darryl Miles G7LED (dlm@g7led.demon.co.uk)
 * Copyright (C) Steven Whitehouse GW7RRM (stevew@acm.org)
 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
 * Copyright (C) Hans-Joachim Hetscher DD8NE (dd8ne@bnv-bamberg.de)
 * Copyright (C) Hans Alblas PE1AYX (hans@esrac.ele.tue.nl)
 * Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
 */
#include <linux/capability.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <asm/system.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 <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/netfilter.h>
#include <linux/sysctl.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <net/tcp_states.h>
#include <net/ip.h>
#include <net/arp.h>



HLIST_HEAD(ax25_list);
DEFINE_SPINLOCK(ax25_list_lock);

static const struct proto_ops ax25_proto_ops;

static void ax25_free_sock(struct sock *sk)
{
	ax25_cb_put(ax25_sk(sk));
}

/*
 *	Socket removal during an interrupt is now safe.
 */
static void ax25_cb_del(ax25_cb *ax25)
{
	if (!hlist_unhashed(&ax25->ax25_node)) {
		spin_lock_bh(&ax25_list_lock);
		hlist_del_init(&ax25->ax25_node);
		spin_unlock_bh(&ax25_list_lock);
		ax25_cb_put(ax25);
	}
}

/*
 *	Kill all bound sockets on a dropped device.
 */
static void ax25_kill_by_device(struct net_device *dev)
{
	ax25_dev *ax25_dev;
	ax25_cb *s;
	struct hlist_node *node;

	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
		return;

	spin_lock_bh(&ax25_list_lock);
	ax25_for_each(s, node, &ax25_list) {
		if (s->ax25_dev == ax25_dev) {
			s->ax25_dev = NULL;
			ax25_disconnect(s, ENETUNREACH);
		}
	}
	spin_unlock_bh(&ax25_list_lock);
}

/*
 *	Handle device status changes.
 */
static int ax25_device_event(struct notifier_block *this, unsigned long event,
	void *ptr)
{
	struct net_device *dev = (struct net_device *)ptr;

	/* Reject non AX.25 devices */
	if (dev->type != ARPHRD_AX25)
		return NOTIFY_DONE;

	switch (event) {
	case NETDEV_UP:
		ax25_dev_device_up(dev);
		break;
	case NETDEV_DOWN:
		ax25_kill_by_device(dev);
		ax25_rt_device_down(dev);
		ax25_dev_device_down(dev);
		break;
	default:
		break;
	}

	return NOTIFY_DONE;
}

/*
 *	Add a socket to the bound sockets list.
 */
void ax25_cb_add(ax25_cb *ax25)
{
	spin_lock_bh(&ax25_list_lock);
	ax25_cb_hold(ax25);
	hlist_add_head(&ax25->ax25_node, &ax25_list);
	spin_unlock_bh(&ax25_list_lock);
}

/*
 *	Find a socket that wants to accept the SABM we have just
 *	received.
 */
struct sock *ax25_find_listener(ax25_address *addr, int digi,
	struct net_device *dev, int type)
{
	ax25_cb *s;
	struct hlist_node *node;

	spin_lock(&ax25_list_lock);
	ax25_for_each(s, node, &ax25_list) {
		if ((s->iamdigi && !digi) || (!s->iamdigi && digi))
			continue;
		if (s->sk && !ax25cmp(&s->source_addr, addr) &&
		    s->sk->sk_type == type && s->sk->sk_state == TCP_LISTEN) {
			/* If device is null we match any device */
			if (s->ax25_dev == NULL || s->ax25_dev->dev == dev) {
				sock_hold(s->sk);
				spin_unlock(&ax25_list_lock);
				return s->sk;
			}
		}
	}
	spin_unlock(&ax25_list_lock);

	return NULL;
}

/*
 *	Find an AX.25 socket given both ends.
 */
struct sock *ax25_get_socket(ax25_address *my_addr, ax25_address *dest_addr,
	int type)
{
	struct sock *sk = NULL;
	ax25_cb *s;
	struct hlist_node *node;

	spin_lock(&ax25_list_lock);
	ax25_for_each(s, node, &ax25_list) {
		if (s->sk && !ax25cmp(&s->source_addr, my_addr) &&
		    !ax25cmp(&s->dest_addr, dest_addr) &&
		    s->sk->sk_type == type) {
			sk = s->sk;
			sock_hold(sk);
			break;
		}
	}

	spin_unlock(&ax25_list_lock);

	return sk;
}

/*
 *	Find an AX.25 control block given both ends. It will only pick up
 *	floating AX.25 control blocks or non Raw socket bound control blocks.
 */
ax25_cb *ax25_find_cb(ax25_address *src_addr, ax25_address *dest_addr,
	ax25_digi *digi, struct net_device *dev)
{
	ax25_cb *s;
	struct hlist_node *node;

	spin_lock_bh(&ax25_list_lock);
	ax25_for_each(s, node, &ax25_list) {
		if (s->sk && s->sk->sk_type != SOCK_SEQPACKET)
			continue;
		if (s->ax25_dev == NULL)
			continue;
		if (ax25cmp(&s->source_addr, src_addr) == 0 && ax25cmp(&s->dest_addr, dest_addr) == 0 && s->ax25_dev->dev == dev) {
			if (digi != NULL && digi->ndigi != 0) {
				if (s->digipeat == NULL)
					continue;
				if (ax25digicmp(s->digipeat, digi) != 0)
					continue;
			} else {
				if (s->digipeat != NULL && s->digipeat->ndigi != 0)
					continue;
			}
			ax25_cb_hold(s);
			spin_unlock_bh(&ax25_list_lock);

			return s;
		}
	}
	spin_unlock_bh(&ax25_list_lock);

	return NULL;
}

EXPORT_SYMBOL(ax25_find_cb);

void ax25_send_to_raw(ax25_address *addr, struct sk_buff *skb, int proto)
{
	ax25_cb *s;
	struct sk_buff *copy;
	struct hlist_node *node;

	spin_lock(&ax25_list_lock);
	ax25_for_each(s, node, &ax25_list) {
		if (s->sk != NULL && ax25cmp(&s->source_addr, addr) == 0 &&
		    s->sk->sk_type == SOCK_RAW &&
		    s->sk->sk_protocol == proto &&
		    s->ax25_dev->dev == skb->dev &&
		    atomic_read(&s->sk->sk_rmem_alloc) <= s->sk->sk_rcvbuf) {
			if ((copy = skb_clone(skb, GFP_ATOMIC)) == NULL)
				continue;
			if (sock_queue_rcv_skb(s->sk, copy) != 0)
				kfree_skb(copy);
		}
	}
	spin_unlock(&ax25_list_lock);
}

/*
 *	Deferred destroy.
 */
void ax25_destroy_socket(ax25_cb *);

/*
 *	Handler for deferred kills.
 */
static void ax25_destroy_timer(unsigned long data)
{
	ax25_cb *ax25=(ax25_cb *)data;
	struct sock *sk;
	
	sk=ax25->sk;
	
	bh_lock_sock(sk);
	sock_hold(sk);
	ax25_destroy_socket(ax25);
	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 ax25_destroy_socket(ax25_cb *ax25)
{
	struct sk_buff *skb;

	ax25_cb_del(ax25);

	ax25_stop_heartbeat(ax25);
	ax25_stop_t1timer(ax25);
	ax25_stop_t2timer(ax25);
	ax25_stop_t3timer(ax25);
	ax25_stop_idletimer(ax25);

	ax25_clear_queues(ax25);	/* Flush the queues */

	if (ax25->sk != NULL) {
		while ((skb = skb_dequeue(&ax25->sk->sk_receive_queue)) != NULL) {
			if (skb->sk != ax25->sk) {
				/* A pending connection */
				ax25_cb *sax25 = ax25_sk(skb->sk);

				/* Queue the unaccepted socket for death */
				sock_orphan(skb->sk);

				ax25_start_heartbeat(sax25);
				sax25->state = AX25_STATE_0;
			}

			kfree_skb(skb);
		}
		skb_queue_purge(&ax25->sk->sk_write_queue);
	}

	if (ax25->sk != NULL) {
		if (atomic_read(&ax25->sk->sk_wmem_alloc) ||
		    atomic_read(&ax25->sk->sk_rmem_alloc)) {
			/* Defer: outstanding buffers */
			init_timer(&ax25->dtimer);
			ax25->dtimer.expires  = jiffies + 2 * HZ;
			ax25->dtimer.function = ax25_destroy_timer;
			ax25->dtimer.data     = (unsigned long)ax25;
			add_timer(&ax25->dtimer);
		} else {
			struct sock *sk=ax25->sk;
			ax25->sk=NULL;
			sock_put(sk);
		}
	} else {
		ax25_cb_put(ax25);
	}
}

/*
 * dl1bke 960311: set parameters for existing AX.25 connections,
 *		  includes a KILL command to abort any connection.
 *		  VERY useful for debugging ;-)
 */
static int ax25_ctl_ioctl(const unsigned int cmd, void __user *arg)
{
	struct ax25_ctl_struct ax25_ctl;
	ax25_digi digi;
	ax25_dev *ax25_dev;
	ax25_cb *ax25;
	unsigned int k;

	if (copy_from_user(&ax25_ctl, arg, sizeof(ax25_ctl)))
		return -EFAULT;

	if ((ax25_dev = ax25_addr_ax25dev(&ax25_ctl.port_addr)) == NULL)
		return -ENODEV;

	if (ax25_ctl.digi_count > AX25_MAX_DIGIS)
		return -EINVAL;

	digi.ndigi = ax25_ctl.digi_count;
	for (k = 0; k < digi.ndigi; k++)
		digi.calls[k] = ax25_ctl.digi_addr[k];

	if ((ax25 = ax25_find_cb(&ax25_ctl.source_addr, &ax25_ctl.dest_addr, &digi, ax25_dev->dev)) == NULL)
		return -ENOTCONN;

	switch (ax25_ctl.cmd) {
	case AX25_KILL:
		ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
#ifdef CONFIG_AX25_DAMA_SLAVE
		if (ax25_dev->dama.slave && ax25->ax25_dev->values[AX25_VALUES_PROTOCOL] == AX25_PROTO_DAMA_SLAVE)
			ax25_dama_off(ax25);
#endif
		ax25_disconnect(ax25, ENETRESET);
		break;

  	case AX25_WINDOW:
  		if (ax25->modulus == AX25_MODULUS) {
  			if (ax25_ctl.arg < 1 || ax25_ctl.arg > 7)
  				return -EINVAL;
  		} else {
  			if (ax25_ctl.arg < 1 || ax25_ctl.arg > 63)
  				return -EINVAL;
  		}
  		ax25->window = ax25_ctl.arg;
  		break;

  	case AX25_T1:
		if (ax25_ctl.arg < 1)
  			return -EINVAL;
  		ax25->rtt = (ax25_ctl.arg * HZ) / 2;
  		ax25->t1  = ax25_ctl.arg * HZ;
  		break;

  	case AX25_T2:
  		if (ax25_ctl.arg < 1)
  			return -EINVAL;
  		ax25->t2 = ax25_ctl.arg * HZ;
  		break;

  	case AX25_N2:
  		if (ax25_ctl.arg < 1 || ax25_ctl.arg > 31)
			return -EINVAL;
  		ax25->n2count = 0;
  		ax25->n2 = ax25_ctl.arg;
  		break;

  	case AX25_T3:
  		if (ax25_ctl.arg < 0)
  			return -EINVAL;
  		ax25->t3 = ax25_ctl.arg * HZ;
  		break;

  	case AX25_IDLE:
  		if (ax25_ctl.arg < 0)
  			return -EINVAL;
  		ax25->idle = ax25_ctl.arg * 60 * HZ;
  		break;

  	case AX25_PACLEN:
  		if (ax25_ctl.arg < 16 || ax25_ctl.arg > 65535)
  			return -EINVAL;
  		ax25->paclen = ax25_ctl.arg;
  		break;

  	default:
  		return -EINVAL;
	  }

	return 0;
}

static void ax25_fillin_cb_from_dev(ax25_cb *ax25, ax25_dev *ax25_dev)
{
	ax25->rtt     = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_T1]) / 2;
	ax25->t1      = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_T1]);
	ax25->t2      = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_T2]);
	ax25->t3      = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_T3]);
	ax25->n2      = ax25_dev->values[AX25_VALUES_N2];
	ax25->paclen  = ax25_dev->values[AX25_VALUES_PACLEN];
	ax25->idle    = msecs_to_jiffies(ax25_dev->values[AX25_VALUES_IDLE]);
	ax25->backoff = ax25_dev->values[AX25_VALUES_BACKOFF];

	if (ax25_dev->values[AX25_VALUES_AXDEFMODE]) {
		ax25->modulus = AX25_EMODULUS;
		ax25->window  = ax25_dev->values[AX25_VALUES_EWINDOW];
	} else {
		ax25->modulus = AX25_MODULUS;
		ax25->window  = ax25_dev->values[AX25_VALUES_WINDOW];
	}
}

/*
 *	Fill in a created AX.25 created control block with the default
 *	values for a particular device.
 */
void ax25_fillin_cb(ax25_cb *ax25, ax25_dev *ax25_dev)
{
	ax25->ax25_dev = ax25_dev;

	if (ax25->ax25_dev != NULL) {
		ax25_fillin_cb_from_dev(ax25, ax25_dev);
		return;
	}

	/*
	 * No device, use kernel / AX.25 spec default values
	 */
	ax25->rtt     = msecs_to_jiffies(AX25_DEF_T1) / 2;
	ax25->t1      = msecs_to_jiffies(AX25_DEF_T1);
	ax25->t2      = msecs_to_jiffies(AX25_DEF_T2);
	ax25->t3      = msecs_to_jiffies(AX25_DEF_T3);
	ax25->n2      = AX25_DEF_N2;
	ax25->paclen  = AX25_DEF_PACLEN;
	ax25->idle    = msecs_to_jiffies(AX25_DEF_IDLE);
	ax25->backoff = AX25_DEF_BACKOFF;

	if (AX25_DEF_AXDEFMODE) {
		ax25->modulus = AX25_EMODULUS;
		ax25->window  = AX25_DEF_EWINDOW;
	} else {
		ax25->modulus = AX25_MODULUS;
		ax25->window  = AX25_DEF_WINDOW;
	}
}

/*
 * Create an empty AX.25 control block.
 */
ax25_cb *ax25_create_cb(void)
{
	ax25_cb *ax25;

	if ((ax25 = kzalloc(sizeof(*ax25), GFP_ATOMIC)) == NULL)
		return NULL;

	atomic_set(&ax25->refcount, 1);

	skb_queue_head_init(&ax25->write_queue);
	skb_queue_head_init(&ax25->frag_queue);
	skb_queue_head_init(&ax25->ack_queue);
	skb_queue_head_init(&ax25->reseq_queue);

	init_timer(&ax25->timer);
	init_timer(&ax25->t1timer);
	init_timer(&ax25->t2timer);
	init_timer(&ax25->t3timer);
	init_timer(&ax25->idletimer);

	ax25_fillin_cb(ax25, NULL);

	ax25->state = AX25_STATE_0;

	return ax25;
}

/*
 *	Handling for system calls applied via the various interfaces to an
 *	AX25 socket object
 */

static int ax25_setsockopt(struct socket *sock, int level, int optname,
	char __user *optval, int optlen)
{
	struct sock *sk = sock->sk;
	ax25_cb *ax25;
	struct net_device *dev;
	char devname[IFNAMSIZ];
	int opt, res = 0;

	if (level != SOL_AX25)
		return -ENOPROTOOPT;

	if (optlen < sizeof(int))
		return -EINVAL;

	if (get_user(opt, (int __user *)optval))
		return -EFAULT;

	lock_sock(sk);
	ax25 = ax25_sk(sk);

	switch (optname) {
	case AX25_WINDOW:
		if (ax25->modulus == AX25_MODULUS) {
			if (opt < 1 || opt > 7) {
				res = -EINVAL;
				break;
			}
		} else {
			if (opt < 1 || opt > 63) {
				res = -EINVAL;
				break;
			}
		}
		ax25->window = opt;
		break;

	case AX25_T1:
		if (opt < 1) {
			res = -EINVAL;
			break;
		}
		ax25->rtt = (opt * HZ) / 2;
		ax25->t1  = opt * HZ;
		break;

	case AX25_T2:
		if (opt < 1) {
			res = -EINVAL;
			break;
		}
		ax25->t2 = opt * HZ;
		break;

	case AX25_N2:
		if (opt < 1 || opt > 31) {
			res = -EINVAL;
			break;
		}
		ax25->n2 = opt;
		break;

	case AX25_T3:
		if (opt < 1) {
			res = -EINVAL;
			break;
		}
		ax25->t3 = opt * HZ;
		break;

	case AX25_IDLE:
		if (opt < 0) {
			res = -EINVAL;
			break;
		}
		ax25->idle = opt * 60 * HZ;
		break;

	case AX25_BACKOFF:
		if (opt < 0 || opt > 2) {
			res = -EINVAL;
			break;
		}
		ax25->backoff = opt;
		break;

	case AX25_EXTSEQ:
		ax25->modulus = opt ? AX25_EMODULUS : AX25_MODULUS;
		break;

	case AX25_PIDINCL:
		ax25->pidincl = opt ? 1 : 0;
		break;

	case AX25_IAMDIGI:
		ax25->iamdigi = opt ? 1 : 0;
		break;

	case AX25_PACLEN:
		if (opt < 16 || opt > 65535) {
			res = -EINVAL;
			break;
		}
		ax25->paclen = opt;
		break;

	case SO_BINDTODEVICE:
		if (optlen > IFNAMSIZ)
			optlen=IFNAMSIZ;
		if (copy_from_user(devname, optval, optlen)) {
		res = -EFAULT;
			break;
		}

		dev = dev_get_by_name(devname);
		if (dev == NULL) {
			res = -ENODEV;
			break;
		}

		if (sk->sk_type == SOCK_SEQPACKET &&
		   (sock->state != SS_UNCONNECTED ||
		    sk->sk_state == TCP_LISTEN)) {
			res = -EADDRNOTAVAIL;
			dev_put(dev);
			break;
		}

		ax25->ax25_dev = ax25_dev_ax25dev(dev);
		ax25_fillin_cb(ax25, ax25->ax25_dev);
		break;

	default:
		res = -ENOPROTOOPT;
	}
	release_sock(sk);

	return res;
}

static int ax25_getsockopt(struct socket *sock, int level, int optname,
	char __user *optval, int __user *optlen)
{
	struct sock *sk = sock->sk;
	ax25_cb *ax25;
	struct ax25_dev *ax25_dev;
	char devname[IFNAMSIZ];
	void *valptr;
	int val = 0;
	int maxlen, length;

	if (level != SOL_AX25)
		return -ENOPROTOOPT;

	if (get_user(maxlen, optlen))
		return -EFAULT;

	if (maxlen < 1)
		return -EFAULT;

	valptr = (void *) &val;
	length = min_t(unsigned int, maxlen, sizeof(int));

	lock_sock(sk);
	ax25 = ax25_sk(sk);

	switch (optname) {
	case AX25_WINDOW:
		val = ax25->window;
		break;

	case AX25_T1:
		val = ax25->t1 / HZ;
		break;

	case AX25_T2:
		val = ax25->t2 / HZ;
		break;

	case AX25_N2:
		val = ax25->n2;
		break;

	case AX25_T3:
		val = ax25->t3 / HZ;
		break;

	case AX25_IDLE:
		val = ax25->idle / (60 * HZ);
		break;

	case AX25_BACKOFF:
		val = ax25->backoff;
		break;

	case AX25_EXTSEQ:
		val = (ax25->modulus == AX25_EMODULUS);
		break;

	case AX25_PIDINCL:
		val = ax25->pidincl;
		break;

	case AX25_IAMDIGI:
		val = ax25->iamdigi;
		break;

	case AX25_PACLEN:
		val = ax25->paclen;
		break;

	case SO_BINDTODEVICE:
		ax25_dev = ax25->ax25_dev;

		if (ax25_dev != NULL && ax25_dev->dev != NULL) {
			strlcpy(devname, ax25_dev->dev->name, sizeof(devname));
			length = strlen(devname) + 1;
		} else {
			*devname = '\0';
			length = 1;
		}

		valptr = (void *) devname;
		break;

	default:
		release_sock(sk);
		return -ENOPROTOOPT;
	}
	release_sock(sk);

	if (put_user(length, optlen))
		return -EFAULT;

	return copy_to_user(optval, valptr, length) ? -EFAULT : 0;
}

static int ax25_listen(struct socket *sock, int backlog)
{
	struct sock *sk = sock->sk;
	int res = 0;

	lock_sock(sk);
	if (sk->sk_type == SOCK_SEQPACKET && sk->sk_state != TCP_LISTEN) {
		sk->sk_max_ack_backlog = backlog;
		sk->sk_state           = TCP_LISTEN;
		goto out;
	}
	res = -EOPNOTSUPP;

out:
	release_sock(sk);

	return res;
}

/*
 * XXX: when creating ax25_sock we should update the .obj_size setting
 * below.
 */
static struct proto ax25_proto = {
	.name	  = "AX25",
	.owner	  = THIS_MODULE,
	.obj_size = sizeof(struct sock),
};

static int ax25_create(struct socket *sock, int protocol)
{
	struct sock *sk;
	ax25_cb *ax25;

	switch (sock->type) {
	case SOCK_DGRAM:
		if (protocol == 0 || protocol == PF_AX25)
			protocol = AX25_P_TEXT;
		break;

	case SOCK_SEQPACKET:
		switch (protocol) {
		case 0:
		case PF_AX25:	/* For CLX */
			protocol = AX25_P_TEXT;
			break;
		case AX25_P_SEGMENT:
#ifdef CONFIG_INET
		case AX25_P_ARP:
		case AX25_P_IP:
#endif
#ifdef CONFIG_NETROM
		case AX25_P_NETROM:
#endif
#ifdef CONFIG_ROSE
		case AX25_P_ROSE:
#endif
			return -ESOCKTNOSUPPORT;
#ifdef CONFIG_NETROM_MODULE
		case AX25_P_NETROM:
			if (ax25_protocol_is_registered(AX25_P_NETROM))
				return -ESOCKTNOSUPPORT;
#endif
#ifdef CONFIG_ROSE_MODULE
		case AX25_P_ROSE:
			if (ax25_protocol_is_registered(AX25_P_ROSE))
				return -ESOCKTNOSUPPORT;
#endif
		default:
			break;
		}
		break;

	case SOCK_RAW:
		break;
	default:
		return -ESOCKTNOSUPPORT;
	}

	if ((sk = sk_alloc(PF_AX25, GFP_ATOMIC, &ax25_proto, 1)) == NULL)
		return -ENOMEM;

	ax25 = sk->sk_protinfo = ax25_create_cb();
	if (!ax25) {
		sk_free(sk);
		return -ENOMEM;
	}

	sock_init_data(sock, sk);

	sk->sk_destruct = ax25_free_sock;
	sock->ops    = &ax25_proto_ops;
	sk->sk_protocol = protocol;

	ax25->sk    = sk;

	return 0;
}

struct sock *ax25_make_new(struct sock *osk, struct ax25_dev *ax25_dev)
{
	struct sock *sk;
	ax25_cb *ax25, *oax25;

	if ((sk = sk_alloc(PF_AX25, GFP_ATOMIC, osk->sk_prot, 1)) == NULL)
		return NULL;

	if ((ax25 = ax25_create_cb()) == NULL) {
		sk_free(sk);
		return NULL;
	}

	switch (osk->sk_type) {
	case SOCK_DGRAM:
		break;
	case SOCK_SEQPACKET:
		break;
	default:
		sk_free(sk);
		ax25_cb_put(ax25);
		return NULL;
	}

	sock_init_data(NULL, sk);

	sk->sk_destruct = ax25_free_sock;
	sk->sk_type     = osk->sk_type;
	sk->sk_socket   = osk->sk_socket;
	sk->sk_priority = 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;
	sk->sk_sleep    = osk->sk_sleep;
	sock_copy_flags(sk, osk);

	oax25 = ax25_sk(osk);

	ax25->modulus = oax25->modulus;
	ax25->backoff = oax25->backoff;
	ax25->pidincl = oax25->pidincl;
	ax25->iamdigi = oax25->iamdigi;
	ax25->rtt     = oax25->rtt;
	ax25->t1      = oax25->t1;
	ax25->t2      = oax25->t2;
	ax25->t3      = oax25->t3;
	ax25->n2      = oax25->n2;
	ax25->idle    = oax25->idle;
	ax25->paclen  = oax25->paclen;
	ax25->window  = oax25->window;

	ax25->ax25_dev    = ax25_dev;
	ax25->source_addr = oax25->source_addr;

	if (oax25->digipeat != NULL) {
		if ((ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
			sk_free(sk);
			ax25_cb_put(ax25);
			return NULL;
		}

		memcpy(ax25->digipeat, oax25->digipeat, sizeof(ax25_digi));
	}

	sk->sk_protinfo = ax25;
	ax25->sk    = sk;

	return sk;
}

static int ax25_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	ax25_cb *ax25;

	if (sk == NULL)
		return 0;

	sock_hold(sk);
	sock_orphan(sk);
	lock_sock(sk);
	ax25 = ax25_sk(sk);

	if (sk->sk_type == SOCK_SEQPACKET) {
		switch (ax25->state) {
		case AX25_STATE_0:
			release_sock(sk);
			ax25_disconnect(ax25, 0);
			lock_sock(sk);
			ax25_destroy_socket(ax25);
			break;

		case AX25_STATE_1:
		case AX25_STATE_2:
			ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
			release_sock(sk);
			ax25_disconnect(ax25, 0);
			lock_sock(sk);
			ax25_destroy_socket(ax25);
			break;

		case AX25_STATE_3:
		case AX25_STATE_4:
			ax25_clear_queues(ax25);
			ax25->n2count = 0;

			switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
			case AX25_PROTO_STD_SIMPLEX:
			case AX25_PROTO_STD_DUPLEX:
				ax25_send_control(ax25,
						  AX25_DISC,
						  AX25_POLLON,
						  AX25_COMMAND);
				ax25_stop_t2timer(ax25);
				ax25_stop_t3timer(ax25);
				ax25_stop_idletimer(ax25);
				break;
#ifdef CONFIG_AX25_DAMA_SLAVE
			case AX25_PROTO_DAMA_SLAVE:
				ax25_stop_t3timer(ax25);
				ax25_stop_idletimer(ax25);
				break;
#endif
			}
			ax25_calculate_t1(ax25);
			ax25_start_t1timer(ax25);
			ax25->state = AX25_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;
		}
	} else {
		sk->sk_state     = TCP_CLOSE;
		sk->sk_shutdown |= SEND_SHUTDOWN;
		sk->sk_state_change(sk);
		ax25_destroy_socket(ax25);
	}

	sock->sk   = NULL;
	release_sock(sk);
	sock_put(sk);

	return 0;
}

/*
 *	We support a funny extension here so you can (as root) give any callsign
 *	digipeated via a local address as source. This hack is obsolete now
 *	that we've implemented support for SO_BINDTODEVICE. It is however small
 *	and trivially backward compatible.
 */
static int ax25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
	struct sock *sk = sock->sk;
	struct full_sockaddr_ax25 *addr = (struct full_sockaddr_ax25 *)uaddr;
	ax25_dev *ax25_dev = NULL;
	ax25_uid_assoc *user;
	ax25_address call;
	ax25_cb *ax25;
	int err = 0;

	if (addr_len != sizeof(struct sockaddr_ax25) &&
	    addr_len != sizeof(struct full_sockaddr_ax25)) {
		/* support for old structure may go away some time */
		if ((addr_len < sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 6) ||
		    (addr_len > sizeof(struct full_sockaddr_ax25))) {
			return -EINVAL;
	}

		printk(KERN_WARNING "ax25_bind(): %s uses old (6 digipeater) socket structure.\n",
			current->comm);
	}

	if (addr->fsa_ax25.sax25_family != AF_AX25)
		return -EINVAL;

	user = ax25_findbyuid(current->euid);
	if (user) {
		call = user->call;
		ax25_uid_put(user);
	} else {
		if (ax25_uid_policy && !capable(CAP_NET_ADMIN))
			return -EACCES;

		call = addr->fsa_ax25.sax25_call;
	}

	lock_sock(sk);

	ax25 = ax25_sk(sk);
	if (!sock_flag(sk, SOCK_ZAPPED)) {
		err = -EINVAL;
		goto out;
	}

	ax25->source_addr = call;

	/*
	 * User already set interface with SO_BINDTODEVICE
	 */
	if (ax25->ax25_dev != NULL)
		goto done;

	if (addr_len > sizeof(struct sockaddr_ax25) && addr->fsa_ax25.sax25_ndigis == 1) {
		if (ax25cmp(&addr->fsa_digipeater[0], &null_ax25_address) != 0 &&
		    (ax25_dev = ax25_addr_ax25dev(&addr->fsa_digipeater[0])) == NULL) {
			err = -EADDRNOTAVAIL;
			goto out;
		}
	} else {
		if ((ax25_dev = ax25_addr_ax25dev(&addr->fsa_ax25.sax25_call)) == NULL) {
			err = -EADDRNOTAVAIL;
			goto out;
		}
	}

	if (ax25_dev != NULL)
		ax25_fillin_cb(ax25, ax25_dev);

done:
	ax25_cb_add(ax25);
	sock_reset_flag(sk, SOCK_ZAPPED);

out:
	release_sock(sk);

	return 0;
}

/*
 *	FIXME: nonblock behaviour looks like it may have a bug.
 */
static int ax25_connect(struct socket *sock, struct sockaddr *uaddr,
	int addr_len, int flags)
{
	struct sock *sk = sock->sk;
	ax25_cb *ax25 = ax25_sk(sk), *ax25t;
	struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)uaddr;
	ax25_digi *digi = NULL;
	int ct = 0, err = 0;

	/*
	 * some sanity checks. code further down depends on this
	 */

	if (addr_len == sizeof(struct sockaddr_ax25)) {
		/* support for this will go away in early 2.5.x */
		printk(KERN_WARNING "ax25_connect(): %s uses obsolete socket structure\n",
			current->comm);
	}
	else if (addr_len != sizeof(struct full_sockaddr_ax25)) {
		/* support for old structure may go away some time */
		if ((addr_len < sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 6) ||
		    (addr_len > sizeof(struct full_sockaddr_ax25))) {
			return -EINVAL;
		}

		printk(KERN_WARNING "ax25_connect(): %s uses old (6 digipeater) socket structure.\n",
			current->comm);
	}

	if (fsa->fsa_ax25.sax25_family != AF_AX25)
		return -EINVAL;

	lock_sock(sk);

	/* deal with restarts */
	if (sock->state == SS_CONNECTING) {
		switch (sk->sk_state) {
		case TCP_SYN_SENT: /* still trying */
			err = -EINPROGRESS;
			goto out;

		case TCP_ESTABLISHED: /* connection established */
			sock->state = SS_CONNECTED;
			goto out;

		case TCP_CLOSE: /* connection refused */
			sock->state = SS_UNCONNECTED;
			err = -ECONNREFUSED;
			goto out;
		}
	}

	if (sk->sk_state == TCP_ESTABLISHED && sk->sk_type == SOCK_SEQPACKET) {
		err = -EISCONN;	/* No reconnect on a seqpacket socket */
		goto out;
	}

	sk->sk_state   = TCP_CLOSE;
	sock->state = SS_UNCONNECTED;

	kfree(ax25->digipeat);
	ax25->digipeat = NULL;

	/*
	 *	Handle digi-peaters to be used.
	 */
	if (addr_len > sizeof(struct sockaddr_ax25) &&
	    fsa->fsa_ax25.sax25_ndigis != 0) {
		/* Valid number of digipeaters ? */
		if (fsa->fsa_ax25.sax25_ndigis < 1 || fsa->fsa_ax25.sax25_ndigis > AX25_MAX_DIGIS) {
			err = -EINVAL;
			goto out;
		}

		if ((digi = kmalloc(sizeof(ax25_digi), GFP_KERNEL)) == NULL) {
			err = -ENOBUFS;
			goto out;
		}

		digi->ndigi      = fsa->fsa_ax25.sax25_ndigis;
		digi->lastrepeat = -1;

		while (ct < fsa->fsa_ax25.sax25_ndigis) {
			if ((fsa->fsa_digipeater[ct].ax25_call[6] &
			     AX25_HBIT) && ax25->iamdigi) {
				digi->repeated[ct] = 1;
				digi->lastrepeat   = ct;
			} else {
				digi->repeated[ct] = 0;
			}
			digi->calls[ct] = fsa->fsa_digipeater[ct];
			ct++;
		}
	}

	/*
	 *	Must bind first - autobinding in this may or may not work. If
	 *	the socket is already bound, check to see if the device has
	 *	been filled in, error if it hasn't.
	 */
	if (sock_flag(sk, SOCK_ZAPPED)) {
		/* check if we can remove this feature. It is broken. */
		printk(KERN_WARNING "ax25_connect(): %s uses autobind, please contact jreuter@yaina.de\n",
			current->comm);
		if ((err = ax25_rt_autobind(ax25, &fsa->fsa_ax25.sax25_call)) < 0) {
			kfree(digi);
			goto out;
		}

		ax25_fillin_cb(ax25, ax25->ax25_dev);
		ax25_cb_add(ax25);
	} else {
		if (ax25->ax25_dev == NULL) {
			kfree(digi);
			err = -EHOSTUNREACH;
			goto out;
		}
	}

	if (sk->sk_type == SOCK_SEQPACKET &&
	    (ax25t=ax25_find_cb(&ax25->source_addr, &fsa->fsa_ax25.sax25_call, digi,
		    	 ax25->ax25_dev->dev))) {
		kfree(digi);
		err = -EADDRINUSE;		/* Already such a connection */
		ax25_cb_put(ax25t);
		goto out;
	}

	ax25->dest_addr = fsa->fsa_ax25.sax25_call;
	ax25->digipeat  = digi;

	/* First the easy one */
	if (sk->sk_type != SOCK_SEQPACKET) {
		sock->state = SS_CONNECTED;
		sk->sk_state   = TCP_ESTABLISHED;
		goto out;
	}

	/* Move to connecting socket, ax.25 lapb WAIT_UA.. */
	sock->state        = SS_CONNECTING;
	sk->sk_state          = TCP_SYN_SENT;

	switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) {
	case AX25_PROTO_STD_SIMPLEX:
	case AX25_PROTO_STD_DUPLEX:
		ax25_std_establish_data_link(ax25);
		break;

#ifdef CONFIG_AX25_DAMA_SLAVE
	case AX25_PROTO_DAMA_SLAVE:
		ax25->modulus = AX25_MODULUS;
		ax25->window  = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
		if (ax25->ax25_dev->dama.slave)
			ax25_ds_establish_data_link(ax25);
		else
			ax25_std_establish_data_link(ax25);
		break;
#endif
	}

	ax25->state = AX25_STATE_1;

	ax25_start_heartbeat(ax25);

	/* Now the loop */
	if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK)) {
		err = -EINPROGRESS;
		goto out;
	}

	if (sk->sk_state == TCP_SYN_SENT) {
		struct task_struct *tsk = current;
		DECLARE_WAITQUEUE(wait, tsk);

		add_wait_queue(sk->sk_sleep, &wait);
		for (;;) {
			if (sk->sk_state != TCP_SYN_SENT)
				break;
			set_current_state(TASK_INTERRUPTIBLE);
			release_sock(sk);
			if (!signal_pending(tsk)) {
				schedule();
				lock_sock(sk);
				continue;
			}
			current->state = TASK_RUNNING;
			remove_wait_queue(sk->sk_sleep, &wait);
			return -ERESTARTSYS;
		}
		current->state = TASK_RUNNING;
		remove_wait_queue(sk->sk_sleep, &wait);
	}

	if (sk->sk_state != TCP_ESTABLISHED) {
		/* Not in ABM, not in WAIT_UA -> failed */
		sock->state = SS_UNCONNECTED;
		err = sock_error(sk);	/* Always set at this point */
		goto out;
	}

	sock->state = SS_CONNECTED;

	err=0;
out:
	release_sock(sk);

	return err;
}


static int ax25_accept(struct socket *sock, struct socket *newsock, int flags)
{
	struct task_struct *tsk = current;
	DECLARE_WAITQUEUE(wait, tsk);
	struct sk_buff *skb;
	struct sock *newsk;
	struct sock *sk;
	int err = 0;

	if (sock->state != SS_UNCONNECTED)
		return -EINVAL;

	if ((sk = sock->sk) == NULL)
		return -EINVAL;

	lock_sock(sk);
	if (sk->sk_type != SOCK_SEQPACKET) {
		err = -EOPNOTSUPP;
		goto out;
	}

	if (sk->sk_state != TCP_LISTEN) {
		err = -EINVAL;
		goto out;
	}

	/*
	 *	The read queue this time is holding sockets ready to use
	 *	hooked into the SABM we saved
	 */
	add_wait_queue(sk->sk_sleep, &wait);
	for (;;) {
		skb = skb_dequeue(&sk->sk_receive_queue);
		if (skb)
			break;

		release_sock(sk);
		current->state = TASK_INTERRUPTIBLE;
		if (flags & O_NONBLOCK) {
			current->state = TASK_RUNNING;
			remove_wait_queue(sk->sk_sleep, &wait);
			return -EWOULDBLOCK;
		}
		if (!signal_pending(tsk)) {
			schedule();
			lock_sock(sk);
			continue;
		}
		current->state = TASK_RUNNING;
		remove_wait_queue(sk->sk_sleep, &wait);
		return -ERESTARTSYS;
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(sk->sk_sleep, &wait);

	newsk		 = skb->sk;
	newsk->sk_socket = newsock;
	newsk->sk_sleep	 = &newsock->wait;

	/* Now attach up the new socket */
	kfree_skb(skb);
	sk->sk_ack_backlog--;
	newsock->sk    = newsk;
	newsock->state = SS_CONNECTED;

out:
	release_sock(sk);

	return err;
}

static int ax25_getname(struct socket *sock, struct sockaddr *uaddr,
	int *uaddr_len, int peer)
{
	struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)uaddr;
	struct sock *sk = sock->sk;
	unsigned char ndigi, i;
	ax25_cb *ax25;
	int err = 0;

	lock_sock(sk);
	ax25 = ax25_sk(sk);

	if (peer != 0) {
		if (sk->sk_state != TCP_ESTABLISHED) {
			err = -ENOTCONN;
			goto out;
		}

		fsa->fsa_ax25.sax25_family = AF_AX25;
		fsa->fsa_ax25.sax25_call   = ax25->dest_addr;
		fsa->fsa_ax25.sax25_ndigis = 0;

		if (ax25->digipeat != NULL) {
			ndigi = ax25->digipeat->ndigi;
			fsa->fsa_ax25.sax25_ndigis = ndigi;
			for (i = 0; i < ndigi; i++)
				fsa->fsa_digipeater[i] =
						ax25->digipeat->calls[i];
		}
	} else {
		fsa->fsa_ax25.sax25_family = AF_AX25;
		fsa->fsa_ax25.sax25_call   = ax25->source_addr;
		fsa->fsa_ax25.sax25_ndigis = 1;
		if (ax25->ax25_dev != NULL) {
			memcpy(&fsa->fsa_digipeater[0],
			       ax25->ax25_dev->dev->dev_addr, AX25_ADDR_LEN);
		} else {
			fsa->fsa_digipeater[0] = null_ax25_address;
		}
	}
	*uaddr_len = sizeof (struct full_sockaddr_ax25);

out:
	release_sock(sk);

	return err;
}

static int ax25_sendmsg(struct kiocb *iocb, struct socket *sock,
			struct msghdr *msg, size_t len)
{
	struct sockaddr_ax25 *usax = (struct sockaddr_ax25 *)msg->msg_name;
	struct sock *sk = sock->sk;
	struct sockaddr_ax25 sax;
	struct sk_buff *skb;
	ax25_digi dtmp, *dp;
	unsigned char *asmptr;
	ax25_cb *ax25;
	size_t size;
	int lv, err, addr_len = msg->msg_namelen;

	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_CMSG_COMPAT))
		return -EINVAL;

	lock_sock(sk);
	ax25 = ax25_sk(sk);

	if (sock_flag(sk, SOCK_ZAPPED)) {
		err = -EADDRNOTAVAIL;
		goto out;
	}

	if (sk->sk_shutdown & SEND_SHUTDOWN) {
		send_sig(SIGPIPE, current, 0);
		err = -EPIPE;
		goto out;
	}

	if (ax25->ax25_dev == NULL) {
		err = -ENETUNREACH;
		goto out;
	}

	if (len > ax25->ax25_dev->dev->mtu) {
		err = -EMSGSIZE;
		goto out;
	}
		
	if (usax != NULL) {
		if (usax->sax25_family != AF_AX25) {
			err = -EINVAL;
			goto out;
		}

		if (addr_len == sizeof(struct sockaddr_ax25)) {
			printk(KERN_WARNING "ax25_sendmsg(): %s uses obsolete socket structure\n",
				current->comm);
		}
		else if (addr_len != sizeof(struct full_sockaddr_ax25)) {
			/* support for old structure may go away some time */
			if ((addr_len < sizeof(struct sockaddr_ax25) + sizeof(ax25_address) * 6) ||
		    	    (addr_len > sizeof(struct full_sockaddr_ax25))) {
		    		err = -EINVAL;
				goto out;
			}

			printk(KERN_WARNING "ax25_sendmsg(): %s uses old (6 digipeater) socket structure.\n",
				current->comm);
		}

		if (addr_len > sizeof(struct sockaddr_ax25) && usax->sax25_ndigis != 0) {
			int ct           = 0;
			struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)usax;

			/* Valid number of digipeaters ? */
			if (usax->sax25_ndigis < 1 || usax->sax25_ndigis > AX25_MAX_DIGIS) {
				err = -EINVAL;
				goto out;
			}

			dtmp.ndigi      = usax->sax25_ndigis;

			while (ct < usax->sax25_ndigis) {
				dtmp.repeated[ct] = 0;
				dtmp.calls[ct]    = fsa->fsa_digipeater[ct];
				ct++;
			}

			dtmp.lastrepeat = 0;
		}

		sax = *usax;
		if (sk->sk_type == SOCK_SEQPACKET &&
		    ax25cmp(&ax25->dest_addr, &sax.sax25_call)) {
			err = -EISCONN;
			goto out;
		}
		if (usax->sax25_ndigis == 0)
			dp = NULL;
		else
			dp = &dtmp;
	} else {
		/*
		 *	FIXME: 1003.1g - if the socket is like this because
		 *	it has become closed (not started closed) and is VC
		 *	we ought to SIGPIPE, EPIPE
		 */
		if (sk->sk_state != TCP_ESTABLISHED) {
			err = -ENOTCONN;
			goto out;
		}
		sax.sax25_family = AF_AX25;
		sax.sax25_call   = ax25->dest_addr;
		dp = ax25->digipeat;
	}

	SOCK_DEBUG(sk, "AX.25: sendto: Addresses built.\n");

	/* Build a packet */
	SOCK_DEBUG(sk, "AX.25: sendto: building packet.\n");

	/* Assume the worst case */
	size = len + ax25->ax25_dev->dev->hard_header_len;

	skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT, &err);
	if (skb == NULL)
		goto out;

	skb_reserve(skb, size - len);

	SOCK_DEBUG(sk, "AX.25: Appending user data\n");

	/* User data follows immediately after the AX.25 data */
	if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
		err = -EFAULT;
		kfree_skb(skb);
		goto out;
	}

	skb->nh.raw = skb->data;

	/* Add the PID if one is not supplied by the user in the skb */
	if (!ax25->pidincl) {
		asmptr  = skb_push(skb, 1);
		*asmptr = sk->sk_protocol;
	}

	SOCK_DEBUG(sk, "AX.25: Transmitting buffer\n");

	if (sk->sk_type == SOCK_SEQPACKET) {
		/* Connected mode sockets go via the LAPB machine */
		if (sk->sk_state != TCP_ESTABLISHED) {
			kfree_skb(skb);
			err = -ENOTCONN;
			goto out;
		}

		/* Shove it onto the queue and kick */
		ax25_output(ax25, ax25->paclen, skb);

		err = len;
		goto out;
	}

	asmptr = skb_push(skb, 1 + ax25_addr_size(dp));

	SOCK_DEBUG(sk, "Building AX.25 Header (dp=%p).\n", dp);

	if (dp != NULL)
		SOCK_DEBUG(sk, "Num digipeaters=%d\n", dp->ndigi);

	/* Build an AX.25 header */
	asmptr += (lv = ax25_addr_build(asmptr, &ax25->source_addr,
					&sax.sax25_call, dp,
					AX25_COMMAND, AX25_MODULUS));

	SOCK_DEBUG(sk, "Built header (%d bytes)\n",lv);

	skb->h.raw = asmptr;

	SOCK_DEBUG(sk, "base=%p pos=%p\n", skb->data, asmptr);

	*asmptr = AX25_UI;

	/* Datagram frames go straight out of the door as UI */
	ax25_queue_xmit(skb, ax25->ax25_dev->dev);

	err = len;

out:
	release_sock(sk);

	return err;
}

static int ax25_recvmsg(struct kiocb *iocb, struct socket *sock,
	struct msghdr *msg, size_t size, int flags)
{
	struct sock *sk = sock->sk;
	struct sk_buff *skb;
	int copied;
	int err = 0;

	lock_sock(sk);
	/*
	 * 	This works for seqpacket too. The receiver has ordered the
	 *	queue for us! We do one quick check first though
	 */
	if (sk->sk_type == SOCK_SEQPACKET && sk->sk_state != TCP_ESTABLISHED) {
		err =  -ENOTCONN;
		goto out;
	}

	/* Now we can treat all alike */
	skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
	                        flags & MSG_DONTWAIT, &err);
	if (skb == NULL)
		goto out;

	if (!ax25_sk(sk)->pidincl)
		skb_pull(skb, 1);		/* Remove PID */

	skb->h.raw = skb->data;
	copied     = skb->len;

	if (copied > size) {
		copied = size;
		msg->msg_flags |= MSG_TRUNC;
	}

	skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);

	if (msg->msg_namelen != 0) {
		struct sockaddr_ax25 *sax = (struct sockaddr_ax25 *)msg->msg_name;
		ax25_digi digi;
		ax25_address src;

		ax25_addr_parse(skb->mac.raw+1, skb->data-skb->mac.raw-1, &src, NULL, &digi, NULL, NULL);

		sax->sax25_family = AF_AX25;
		/* We set this correctly, even though we may not let the
		   application know the digi calls further down (because it
		   did NOT ask to know them).  This could get political... **/
		sax->sax25_ndigis = digi.ndigi;
		sax->sax25_call   = src;

		if (sax->sax25_ndigis != 0) {
			int ct;
			struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)sax;

			for (ct = 0; ct < digi.ndigi; ct++)
				fsa->fsa_digipeater[ct] = digi.calls[ct];
		}
		msg->msg_namelen = sizeof(struct full_sockaddr_ax25);
	}

	skb_free_datagram(sk, skb);
	err = copied;

out:
	release_sock(sk);

	return err;
}

static int ax25_shutdown(struct socket *sk, int how)
{
	/* FIXME - generate DM and RNR states */
	return -EOPNOTSUPP;
}

static int ax25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	struct sock *sk = sock->sk;
	void __user *argp = (void __user *)arg;
	int res = 0;

	lock_sock(sk);
	switch (cmd) {
	case TIOCOUTQ: {
		long amount;
		amount = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
		if (amount < 0)
			amount = 0;
		res = put_user(amount, (int __user *)argp);
		break;
	}

	case TIOCINQ: {
		struct sk_buff *skb;
		long amount = 0L;
		/* These two are safe on a single CPU system as only user tasks fiddle here */
		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
			amount = skb->len;
		res = put_user(amount, (int __user *) argp);
		break;
	}

	case SIOCGSTAMP:
		res = sock_get_timestamp(sk, argp);
		break;

	case SIOCAX25ADDUID:	/* Add a uid to the uid/call map table */
	case SIOCAX25DELUID:	/* Delete a uid from the uid/call map table */
	case SIOCAX25GETUID: {
		struct sockaddr_ax25 sax25;
		if (copy_from_user(&sax25, argp, sizeof(sax25))) {
			res = -EFAULT;
			break;
		}
		res = ax25_uid_ioctl(cmd, &sax25);
		break;
	}

	case SIOCAX25NOUID: {	/* Set the default policy (default/bar) */
		long amount;
		if (!capable(CAP_NET_ADMIN)) {
			res = -EPERM;
			break;
		}
		if (get_user(amount, (long __user *)argp)) {
			res = -EFAULT;
			break;
		}
		if (amount > AX25_NOUID_BLOCK) {
			res = -EINVAL;
			break;
		}
		ax25_uid_policy = amount;
		res = 0;
		break;
	}

	case SIOCADDRT:
	case SIOCDELRT:
	case SIOCAX25OPTRT:
		if (!capable(CAP_NET_ADMIN)) {
			res = -EPERM;
			break;
		}
		res = ax25_rt_ioctl(cmd, argp);
		break;

	case SIOCAX25CTLCON:
		if (!capable(CAP_NET_ADMIN)) {
			res = -EPERM;
			break;
		}
		res = ax25_ctl_ioctl(cmd, argp);
		break;

	case SIOCAX25GETINFO:
	case SIOCAX25GETINFOOLD: {
		ax25_cb *ax25 = ax25_sk(sk);
		struct ax25_info_struct ax25_info;

		ax25_info.t1        = ax25->t1   / HZ;
		ax25_info.t2        = ax25->t2   / HZ;
		ax25_info.t3        = ax25->t3   / HZ;
		ax25_info.idle      = ax25->idle / (60 * HZ);
		ax25_info.n2        = ax25->n2;
		ax25_info.t1timer   = ax25_display_timer(&ax25->t1timer)   / HZ;
		ax25_info.t2timer   = ax25_display_timer(&ax25->t2timer)   / HZ;
		ax25_info.t3timer   = ax25_display_timer(&ax25->t3timer)   / HZ;
		ax25_info.idletimer = ax25_display_timer(&ax25->idletimer) / (60 * HZ);
		ax25_info.n2count   = ax25->n2count;
		ax25_info.state     = ax25->state;
		ax25_info.rcv_q     = atomic_read(&sk->sk_rmem_alloc);
		ax25_info.snd_q     = atomic_read(&sk->sk_wmem_alloc);
		ax25_info.vs        = ax25->vs;
		ax25_info.vr        = ax25->vr;
		ax25_info.va        = ax25->va;
		ax25_info.vs_max    = ax25->vs; /* reserved */
		ax25_info.paclen    = ax25->paclen;
		ax25_info.window    = ax25->window;

		/* old structure? */
		if (cmd == SIOCAX25GETINFOOLD) {
			static int warned = 0;
			if (!warned) {
				printk(KERN_INFO "%s uses old SIOCAX25GETINFO\n",
					current->comm);
				warned=1;
			}

			if (copy_to_user(argp, &ax25_info, sizeof(struct ax25_info_struct_deprecated))) {
				res = -EFAULT;
				break;
			}
		} else {
			if (copy_to_user(argp, &ax25_info, sizeof(struct ax25_info_struct))) {
				res = -EINVAL;
				break;
			}
		}
		res = 0;
		break;
	}

	case SIOCAX25ADDFWD:
	case SIOCAX25DELFWD: {
		struct ax25_fwd_struct ax25_fwd;
		if (!capable(CAP_NET_ADMIN)) {
			res = -EPERM;
			break;
		}
		if (copy_from_user(&ax25_fwd, argp, sizeof(ax25_fwd))) {
			res = -EFAULT;
			break;
		}
		res = ax25_fwd_ioctl(cmd, &ax25_fwd);
		break;
	}

	case SIOCGIFADDR:
	case SIOCSIFADDR:
	case SIOCGIFDSTADDR:
	case SIOCSIFDSTADDR:
	case SIOCGIFBRDADDR:
	case SIOCSIFBRDADDR:
	case SIOCGIFNETMASK:
	case SIOCSIFNETMASK:
	case SIOCGIFMETRIC:
	case SIOCSIFMETRIC:
		res = -EINVAL;
		break;

	default:
		res = -ENOIOCTLCMD;
		break;
	}
	release_sock(sk);

	return res;
}

#ifdef CONFIG_PROC_FS

static void *ax25_info_start(struct seq_file *seq, loff_t *pos)
{
	struct ax25_cb *ax25;
	struct hlist_node *node;
	int i = 0;

	spin_lock_bh(&ax25_list_lock);
	ax25_for_each(ax25, node, &ax25_list) {
		if (i == *pos)
			return ax25;
		++i;
	}
	return NULL;
}

static void *ax25_info_next(struct seq_file *seq, void *v, loff_t *pos)
{
	++*pos;

	return hlist_entry( ((struct ax25_cb *)v)->ax25_node.next,
			    struct ax25_cb, ax25_node);
}
	
static void ax25_info_stop(struct seq_file *seq, void *v)
{
	spin_unlock_bh(&ax25_list_lock);
}

static int ax25_info_show(struct seq_file *seq, void *v)
{
	ax25_cb *ax25 = v;
	char buf[11];
	int k;


	/*
	 * New format:
	 * magic dev src_addr dest_addr,digi1,digi2,.. st vs vr va t1 t1 t2 t2 t3 t3 idle idle n2 n2 rtt window paclen Snd-Q Rcv-Q inode
	 */

	seq_printf(seq, "%8.8lx %s %s%s ",
		   (long) ax25,
		   ax25->ax25_dev == NULL? "???" : ax25->ax25_dev->dev->name,
		   ax2asc(buf, &ax25->source_addr),
		   ax25->iamdigi? "*":"");
	seq_printf(seq, "%s", ax2asc(buf, &ax25->dest_addr));

	for (k=0; (ax25->digipeat != NULL) && (k < ax25->digipeat->ndigi); k++) {
		seq_printf(seq, ",%s%s",
			   ax2asc(buf, &ax25->digipeat->calls[k]),
			   ax25->digipeat->repeated[k]? "*":"");
	}

	seq_printf(seq, " %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %d %d",
		   ax25->state,
		   ax25->vs, ax25->vr, ax25->va,
		   ax25_display_timer(&ax25->t1timer) / HZ, ax25->t1 / HZ,
		   ax25_display_timer(&ax25->t2timer) / HZ, ax25->t2 / HZ,
		   ax25_display_timer(&ax25->t3timer) / HZ, ax25->t3 / HZ,
		   ax25_display_timer(&ax25->idletimer) / (60 * HZ),
		   ax25->idle / (60 * HZ),
		   ax25->n2count, ax25->n2,
		   ax25->rtt / HZ,
		   ax25->window,
		   ax25->paclen);

	if (ax25->sk != NULL) {
		bh_lock_sock(ax25->sk);
		seq_printf(seq," %d %d %ld\n",
			   atomic_read(&ax25->sk->sk_wmem_alloc),
			   atomic_read(&ax25->sk->sk_rmem_alloc),
			   ax25->sk->sk_socket != NULL ? SOCK_INODE(ax25->sk->sk_socket)->i_ino : 0L);
		bh_unlock_sock(ax25->sk);
	} else {
		seq_puts(seq, " * * *\n");
	}
	return 0;
}

static struct seq_operations ax25_info_seqops = {
	.start = ax25_info_start,
	.next = ax25_info_next,
	.stop = ax25_info_stop,
	.show = ax25_info_show,
};

static int ax25_info_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &ax25_info_seqops);
}

static struct file_operations ax25_info_fops = {
	.owner = THIS_MODULE,
	.open = ax25_info_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
};

#endif

static struct net_proto_family ax25_family_ops = {
	.family =	PF_AX25,
	.create =	ax25_create,
	.owner	=	THIS_MODULE,
};

static const struct proto_ops ax25_proto_ops = {
	.family		= PF_AX25,
	.owner		= THIS_MODULE,
	.release	= ax25_release,
	.bind		= ax25_bind,
	.connect	= ax25_connect,
	.socketpair	= sock_no_socketpair,
	.accept		= ax25_accept,
	.getname	= ax25_getname,
	.poll		= datagram_poll,
	.ioctl		= ax25_ioctl,
	.listen		= ax25_listen,
	.shutdown	= ax25_shutdown,
	.setsockopt	= ax25_setsockopt,
	.getsockopt	= ax25_getsockopt,
	.sendmsg	= ax25_sendmsg,
	.recvmsg	= ax25_recvmsg,
	.mmap		= sock_no_mmap,
	.sendpage	= sock_no_sendpage,
};

/*
 *	Called by socket.c on kernel start up
 */
static struct packet_type ax25_packet_type = {
	.type	=	__constant_htons(ETH_P_AX25),
	.dev	=	NULL,				/* All devices */
	.func	=	ax25_kiss_rcv,
};

static struct notifier_block ax25_dev_notifier = {
	.notifier_call =ax25_device_event,
};

static int __init ax25_init(void)
{
	int rc = proto_register(&ax25_proto, 0);

	if (rc != 0)
		goto out;

	sock_register(&ax25_family_ops);
	dev_add_pack(&ax25_packet_type);
	register_netdevice_notifier(&ax25_dev_notifier);
	ax25_register_sysctl();

	proc_net_fops_create("ax25_route", S_IRUGO, &ax25_route_fops);
	proc_net_fops_create("ax25", S_IRUGO, &ax25_info_fops);
	proc_net_fops_create("ax25_calls", S_IRUGO, &ax25_uid_fops);
out:
	return rc;
}
module_init(ax25_init);


MODULE_AUTHOR("Jonathan Naylor G4KLX <g4klx@g4klx.demon.co.uk>");
MODULE_DESCRIPTION("The amateur radio AX.25 link layer protocol");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_AX25);

static void __exit ax25_exit(void)
{
	proc_net_remove("ax25_route");
	proc_net_remove("ax25");
	proc_net_remove("ax25_calls");
	ax25_rt_free();
	ax25_uid_free();
	ax25_dev_free();

	ax25_unregister_sysctl();
	unregister_netdevice_notifier(&ax25_dev_notifier);

	dev_remove_pack(&ax25_packet_type);

	sock_unregister(PF_AX25);
	proto_unregister(&ax25_proto);
}
module_exit(ax25_exit);