xref: /linux/net/x25/af_x25.c (revision 3213486f2e442831e324cc6201a2f9e924ecc235)
1 /*
2  *	X.25 Packet Layer release 002
3  *
4  *	This is ALPHA test software. This code may break your machine,
5  *	randomly fail to work with new releases, misbehave and/or generally
6  *	screw up. It might even work.
7  *
8  *	This code REQUIRES 2.1.15 or higher
9  *
10  *	This module:
11  *		This module is free software; you can redistribute it and/or
12  *		modify it under the terms of the GNU General Public License
13  *		as published by the Free Software Foundation; either version
14  *		2 of the License, or (at your option) any later version.
15  *
16  *	History
17  *	X.25 001	Jonathan Naylor	Started coding.
18  *	X.25 002	Jonathan Naylor	Centralised disconnect handling.
19  *					New timer architecture.
20  *	2000-03-11	Henner Eisen	MSG_EOR handling more POSIX compliant.
21  *	2000-03-22	Daniela Squassoni Allowed disabling/enabling of
22  *					  facilities negotiation and increased
23  *					  the throughput upper limit.
24  *	2000-08-27	Arnaldo C. Melo s/suser/capable/ + micro cleanups
25  *	2000-09-04	Henner Eisen	Set sock->state in x25_accept().
26  *					Fixed x25_output() related skb leakage.
27  *	2000-10-02	Henner Eisen	Made x25_kick() single threaded per socket.
28  *	2000-10-27	Henner Eisen    MSG_DONTWAIT for fragment allocation.
29  *	2000-11-14	Henner Eisen    Closing datalink from NETDEV_GOING_DOWN
30  *	2002-10-06	Arnaldo C. Melo Get rid of cli/sti, move proc stuff to
31  *					x25_proc.c, using seq_file
32  *	2005-04-02	Shaun Pereira	Selective sub address matching
33  *					with call user data
34  *	2005-04-15	Shaun Pereira	Fast select with no restriction on
35  *					response
36  */
37 
38 #define pr_fmt(fmt) "X25: " fmt
39 
40 #include <linux/module.h>
41 #include <linux/capability.h>
42 #include <linux/errno.h>
43 #include <linux/kernel.h>
44 #include <linux/sched/signal.h>
45 #include <linux/timer.h>
46 #include <linux/string.h>
47 #include <linux/net.h>
48 #include <linux/netdevice.h>
49 #include <linux/if_arp.h>
50 #include <linux/skbuff.h>
51 #include <linux/slab.h>
52 #include <net/sock.h>
53 #include <net/tcp_states.h>
54 #include <linux/uaccess.h>
55 #include <linux/fcntl.h>
56 #include <linux/termios.h>	/* For TIOCINQ/OUTQ */
57 #include <linux/notifier.h>
58 #include <linux/init.h>
59 #include <linux/compat.h>
60 #include <linux/ctype.h>
61 
62 #include <net/x25.h>
63 #include <net/compat.h>
64 
65 int sysctl_x25_restart_request_timeout = X25_DEFAULT_T20;
66 int sysctl_x25_call_request_timeout    = X25_DEFAULT_T21;
67 int sysctl_x25_reset_request_timeout   = X25_DEFAULT_T22;
68 int sysctl_x25_clear_request_timeout   = X25_DEFAULT_T23;
69 int sysctl_x25_ack_holdback_timeout    = X25_DEFAULT_T2;
70 int sysctl_x25_forward                 = 0;
71 
72 HLIST_HEAD(x25_list);
73 DEFINE_RWLOCK(x25_list_lock);
74 
75 static const struct proto_ops x25_proto_ops;
76 
77 static const struct x25_address null_x25_address = {"               "};
78 
79 #ifdef CONFIG_COMPAT
80 struct compat_x25_subscrip_struct {
81 	char device[200-sizeof(compat_ulong_t)];
82 	compat_ulong_t global_facil_mask;
83 	compat_uint_t extended;
84 };
85 #endif
86 
87 
88 int x25_parse_address_block(struct sk_buff *skb,
89 		struct x25_address *called_addr,
90 		struct x25_address *calling_addr)
91 {
92 	unsigned char len;
93 	int needed;
94 	int rc;
95 
96 	if (!pskb_may_pull(skb, 1)) {
97 		/* packet has no address block */
98 		rc = 0;
99 		goto empty;
100 	}
101 
102 	len = *skb->data;
103 	needed = 1 + ((len >> 4) + (len & 0x0f) + 1) / 2;
104 
105 	if (!pskb_may_pull(skb, needed)) {
106 		/* packet is too short to hold the addresses it claims
107 		   to hold */
108 		rc = -1;
109 		goto empty;
110 	}
111 
112 	return x25_addr_ntoa(skb->data, called_addr, calling_addr);
113 
114 empty:
115 	*called_addr->x25_addr = 0;
116 	*calling_addr->x25_addr = 0;
117 
118 	return rc;
119 }
120 
121 
122 int x25_addr_ntoa(unsigned char *p, struct x25_address *called_addr,
123 		  struct x25_address *calling_addr)
124 {
125 	unsigned int called_len, calling_len;
126 	char *called, *calling;
127 	unsigned int i;
128 
129 	called_len  = (*p >> 0) & 0x0F;
130 	calling_len = (*p >> 4) & 0x0F;
131 
132 	called  = called_addr->x25_addr;
133 	calling = calling_addr->x25_addr;
134 	p++;
135 
136 	for (i = 0; i < (called_len + calling_len); i++) {
137 		if (i < called_len) {
138 			if (i % 2 != 0) {
139 				*called++ = ((*p >> 0) & 0x0F) + '0';
140 				p++;
141 			} else {
142 				*called++ = ((*p >> 4) & 0x0F) + '0';
143 			}
144 		} else {
145 			if (i % 2 != 0) {
146 				*calling++ = ((*p >> 0) & 0x0F) + '0';
147 				p++;
148 			} else {
149 				*calling++ = ((*p >> 4) & 0x0F) + '0';
150 			}
151 		}
152 	}
153 
154 	*called = *calling = '\0';
155 
156 	return 1 + (called_len + calling_len + 1) / 2;
157 }
158 
159 int x25_addr_aton(unsigned char *p, struct x25_address *called_addr,
160 		  struct x25_address *calling_addr)
161 {
162 	unsigned int called_len, calling_len;
163 	char *called, *calling;
164 	int i;
165 
166 	called  = called_addr->x25_addr;
167 	calling = calling_addr->x25_addr;
168 
169 	called_len  = strlen(called);
170 	calling_len = strlen(calling);
171 
172 	*p++ = (calling_len << 4) | (called_len << 0);
173 
174 	for (i = 0; i < (called_len + calling_len); i++) {
175 		if (i < called_len) {
176 			if (i % 2 != 0) {
177 				*p |= (*called++ - '0') << 0;
178 				p++;
179 			} else {
180 				*p = 0x00;
181 				*p |= (*called++ - '0') << 4;
182 			}
183 		} else {
184 			if (i % 2 != 0) {
185 				*p |= (*calling++ - '0') << 0;
186 				p++;
187 			} else {
188 				*p = 0x00;
189 				*p |= (*calling++ - '0') << 4;
190 			}
191 		}
192 	}
193 
194 	return 1 + (called_len + calling_len + 1) / 2;
195 }
196 
197 /*
198  *	Socket removal during an interrupt is now safe.
199  */
200 static void x25_remove_socket(struct sock *sk)
201 {
202 	write_lock_bh(&x25_list_lock);
203 	sk_del_node_init(sk);
204 	write_unlock_bh(&x25_list_lock);
205 }
206 
207 /*
208  *	Kill all bound sockets on a dropped device.
209  */
210 static void x25_kill_by_device(struct net_device *dev)
211 {
212 	struct sock *s;
213 
214 	write_lock_bh(&x25_list_lock);
215 
216 	sk_for_each(s, &x25_list)
217 		if (x25_sk(s)->neighbour && x25_sk(s)->neighbour->dev == dev)
218 			x25_disconnect(s, ENETUNREACH, 0, 0);
219 
220 	write_unlock_bh(&x25_list_lock);
221 }
222 
223 /*
224  *	Handle device status changes.
225  */
226 static int x25_device_event(struct notifier_block *this, unsigned long event,
227 			    void *ptr)
228 {
229 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
230 	struct x25_neigh *nb;
231 
232 	if (!net_eq(dev_net(dev), &init_net))
233 		return NOTIFY_DONE;
234 
235 	if (dev->type == ARPHRD_X25
236 #if IS_ENABLED(CONFIG_LLC)
237 	 || dev->type == ARPHRD_ETHER
238 #endif
239 	 ) {
240 		switch (event) {
241 		case NETDEV_UP:
242 			x25_link_device_up(dev);
243 			break;
244 		case NETDEV_GOING_DOWN:
245 			nb = x25_get_neigh(dev);
246 			if (nb) {
247 				x25_terminate_link(nb);
248 				x25_neigh_put(nb);
249 			}
250 			break;
251 		case NETDEV_DOWN:
252 			x25_kill_by_device(dev);
253 			x25_route_device_down(dev);
254 			x25_link_device_down(dev);
255 			break;
256 		}
257 	}
258 
259 	return NOTIFY_DONE;
260 }
261 
262 /*
263  *	Add a socket to the bound sockets list.
264  */
265 static void x25_insert_socket(struct sock *sk)
266 {
267 	write_lock_bh(&x25_list_lock);
268 	sk_add_node(sk, &x25_list);
269 	write_unlock_bh(&x25_list_lock);
270 }
271 
272 /*
273  *	Find a socket that wants to accept the Call Request we just
274  *	received. Check the full list for an address/cud match.
275  *	If no cuds match return the next_best thing, an address match.
276  *	Note: if a listening socket has cud set it must only get calls
277  *	with matching cud.
278  */
279 static struct sock *x25_find_listener(struct x25_address *addr,
280 					struct sk_buff *skb)
281 {
282 	struct sock *s;
283 	struct sock *next_best;
284 
285 	read_lock_bh(&x25_list_lock);
286 	next_best = NULL;
287 
288 	sk_for_each(s, &x25_list)
289 		if ((!strcmp(addr->x25_addr,
290 			x25_sk(s)->source_addr.x25_addr) ||
291 				!strcmp(x25_sk(s)->source_addr.x25_addr,
292 					null_x25_address.x25_addr)) &&
293 					s->sk_state == TCP_LISTEN) {
294 			/*
295 			 * Found a listening socket, now check the incoming
296 			 * call user data vs this sockets call user data
297 			 */
298 			if (x25_sk(s)->cudmatchlength > 0 &&
299 				skb->len >= x25_sk(s)->cudmatchlength) {
300 				if((memcmp(x25_sk(s)->calluserdata.cuddata,
301 					skb->data,
302 					x25_sk(s)->cudmatchlength)) == 0) {
303 					sock_hold(s);
304 					goto found;
305 				 }
306 			} else
307 				next_best = s;
308 		}
309 	if (next_best) {
310 		s = next_best;
311 		sock_hold(s);
312 		goto found;
313 	}
314 	s = NULL;
315 found:
316 	read_unlock_bh(&x25_list_lock);
317 	return s;
318 }
319 
320 /*
321  *	Find a connected X.25 socket given my LCI and neighbour.
322  */
323 static struct sock *__x25_find_socket(unsigned int lci, struct x25_neigh *nb)
324 {
325 	struct sock *s;
326 
327 	sk_for_each(s, &x25_list)
328 		if (x25_sk(s)->lci == lci && x25_sk(s)->neighbour == nb) {
329 			sock_hold(s);
330 			goto found;
331 		}
332 	s = NULL;
333 found:
334 	return s;
335 }
336 
337 struct sock *x25_find_socket(unsigned int lci, struct x25_neigh *nb)
338 {
339 	struct sock *s;
340 
341 	read_lock_bh(&x25_list_lock);
342 	s = __x25_find_socket(lci, nb);
343 	read_unlock_bh(&x25_list_lock);
344 	return s;
345 }
346 
347 /*
348  *	Find a unique LCI for a given device.
349  */
350 static unsigned int x25_new_lci(struct x25_neigh *nb)
351 {
352 	unsigned int lci = 1;
353 	struct sock *sk;
354 
355 	while ((sk = x25_find_socket(lci, nb)) != NULL) {
356 		sock_put(sk);
357 		if (++lci == 4096) {
358 			lci = 0;
359 			break;
360 		}
361 		cond_resched();
362 	}
363 
364 	return lci;
365 }
366 
367 /*
368  *	Deferred destroy.
369  */
370 static void __x25_destroy_socket(struct sock *);
371 
372 /*
373  *	handler for deferred kills.
374  */
375 static void x25_destroy_timer(struct timer_list *t)
376 {
377 	struct sock *sk = from_timer(sk, t, sk_timer);
378 
379 	x25_destroy_socket_from_timer(sk);
380 }
381 
382 /*
383  *	This is called from user mode and the timers. Thus it protects itself
384  *	against interrupt users but doesn't worry about being called during
385  *	work. Once it is removed from the queue no interrupt or bottom half
386  *	will touch it and we are (fairly 8-) ) safe.
387  *	Not static as it's used by the timer
388  */
389 static void __x25_destroy_socket(struct sock *sk)
390 {
391 	struct sk_buff *skb;
392 
393 	x25_stop_heartbeat(sk);
394 	x25_stop_timer(sk);
395 
396 	x25_remove_socket(sk);
397 	x25_clear_queues(sk);		/* Flush the queues */
398 
399 	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
400 		if (skb->sk != sk) {		/* A pending connection */
401 			/*
402 			 * Queue the unaccepted socket for death
403 			 */
404 			skb->sk->sk_state = TCP_LISTEN;
405 			sock_set_flag(skb->sk, SOCK_DEAD);
406 			x25_start_heartbeat(skb->sk);
407 			x25_sk(skb->sk)->state = X25_STATE_0;
408 		}
409 
410 		kfree_skb(skb);
411 	}
412 
413 	if (sk_has_allocations(sk)) {
414 		/* Defer: outstanding buffers */
415 		sk->sk_timer.expires  = jiffies + 10 * HZ;
416 		sk->sk_timer.function = x25_destroy_timer;
417 		add_timer(&sk->sk_timer);
418 	} else {
419 		/* drop last reference so sock_put will free */
420 		__sock_put(sk);
421 	}
422 }
423 
424 void x25_destroy_socket_from_timer(struct sock *sk)
425 {
426 	sock_hold(sk);
427 	bh_lock_sock(sk);
428 	__x25_destroy_socket(sk);
429 	bh_unlock_sock(sk);
430 	sock_put(sk);
431 }
432 
433 /*
434  *	Handling for system calls applied via the various interfaces to a
435  *	X.25 socket object.
436  */
437 
438 static int x25_setsockopt(struct socket *sock, int level, int optname,
439 			  char __user *optval, unsigned int optlen)
440 {
441 	int opt;
442 	struct sock *sk = sock->sk;
443 	int rc = -ENOPROTOOPT;
444 
445 	if (level != SOL_X25 || optname != X25_QBITINCL)
446 		goto out;
447 
448 	rc = -EINVAL;
449 	if (optlen < sizeof(int))
450 		goto out;
451 
452 	rc = -EFAULT;
453 	if (get_user(opt, (int __user *)optval))
454 		goto out;
455 
456 	if (opt)
457 		set_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
458 	else
459 		clear_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
460 	rc = 0;
461 out:
462 	return rc;
463 }
464 
465 static int x25_getsockopt(struct socket *sock, int level, int optname,
466 			  char __user *optval, int __user *optlen)
467 {
468 	struct sock *sk = sock->sk;
469 	int val, len, rc = -ENOPROTOOPT;
470 
471 	if (level != SOL_X25 || optname != X25_QBITINCL)
472 		goto out;
473 
474 	rc = -EFAULT;
475 	if (get_user(len, optlen))
476 		goto out;
477 
478 	len = min_t(unsigned int, len, sizeof(int));
479 
480 	rc = -EINVAL;
481 	if (len < 0)
482 		goto out;
483 
484 	rc = -EFAULT;
485 	if (put_user(len, optlen))
486 		goto out;
487 
488 	val = test_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
489 	rc = copy_to_user(optval, &val, len) ? -EFAULT : 0;
490 out:
491 	return rc;
492 }
493 
494 static int x25_listen(struct socket *sock, int backlog)
495 {
496 	struct sock *sk = sock->sk;
497 	int rc = -EOPNOTSUPP;
498 
499 	lock_sock(sk);
500 	if (sk->sk_state != TCP_LISTEN) {
501 		memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN);
502 		sk->sk_max_ack_backlog = backlog;
503 		sk->sk_state           = TCP_LISTEN;
504 		rc = 0;
505 	}
506 	release_sock(sk);
507 
508 	return rc;
509 }
510 
511 static struct proto x25_proto = {
512 	.name	  = "X25",
513 	.owner	  = THIS_MODULE,
514 	.obj_size = sizeof(struct x25_sock),
515 };
516 
517 static struct sock *x25_alloc_socket(struct net *net, int kern)
518 {
519 	struct x25_sock *x25;
520 	struct sock *sk = sk_alloc(net, AF_X25, GFP_ATOMIC, &x25_proto, kern);
521 
522 	if (!sk)
523 		goto out;
524 
525 	sock_init_data(NULL, sk);
526 
527 	x25 = x25_sk(sk);
528 	skb_queue_head_init(&x25->ack_queue);
529 	skb_queue_head_init(&x25->fragment_queue);
530 	skb_queue_head_init(&x25->interrupt_in_queue);
531 	skb_queue_head_init(&x25->interrupt_out_queue);
532 out:
533 	return sk;
534 }
535 
536 static int x25_create(struct net *net, struct socket *sock, int protocol,
537 		      int kern)
538 {
539 	struct sock *sk;
540 	struct x25_sock *x25;
541 	int rc = -EAFNOSUPPORT;
542 
543 	if (!net_eq(net, &init_net))
544 		goto out;
545 
546 	rc = -ESOCKTNOSUPPORT;
547 	if (sock->type != SOCK_SEQPACKET)
548 		goto out;
549 
550 	rc = -EINVAL;
551 	if (protocol)
552 		goto out;
553 
554 	rc = -ENOBUFS;
555 	if ((sk = x25_alloc_socket(net, kern)) == NULL)
556 		goto out;
557 
558 	x25 = x25_sk(sk);
559 
560 	sock_init_data(sock, sk);
561 
562 	x25_init_timers(sk);
563 
564 	sock->ops    = &x25_proto_ops;
565 	sk->sk_protocol = protocol;
566 	sk->sk_backlog_rcv = x25_backlog_rcv;
567 
568 	x25->t21   = sysctl_x25_call_request_timeout;
569 	x25->t22   = sysctl_x25_reset_request_timeout;
570 	x25->t23   = sysctl_x25_clear_request_timeout;
571 	x25->t2    = sysctl_x25_ack_holdback_timeout;
572 	x25->state = X25_STATE_0;
573 	x25->cudmatchlength = 0;
574 	set_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);	/* normally no cud  */
575 							/* on call accept   */
576 
577 	x25->facilities.winsize_in  = X25_DEFAULT_WINDOW_SIZE;
578 	x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
579 	x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
580 	x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
581 	x25->facilities.throughput  = 0;	/* by default don't negotiate
582 						   throughput */
583 	x25->facilities.reverse     = X25_DEFAULT_REVERSE;
584 	x25->dte_facilities.calling_len = 0;
585 	x25->dte_facilities.called_len = 0;
586 	memset(x25->dte_facilities.called_ae, '\0',
587 			sizeof(x25->dte_facilities.called_ae));
588 	memset(x25->dte_facilities.calling_ae, '\0',
589 			sizeof(x25->dte_facilities.calling_ae));
590 
591 	rc = 0;
592 out:
593 	return rc;
594 }
595 
596 static struct sock *x25_make_new(struct sock *osk)
597 {
598 	struct sock *sk = NULL;
599 	struct x25_sock *x25, *ox25;
600 
601 	if (osk->sk_type != SOCK_SEQPACKET)
602 		goto out;
603 
604 	if ((sk = x25_alloc_socket(sock_net(osk), 0)) == NULL)
605 		goto out;
606 
607 	x25 = x25_sk(sk);
608 
609 	sk->sk_type        = osk->sk_type;
610 	sk->sk_priority    = osk->sk_priority;
611 	sk->sk_protocol    = osk->sk_protocol;
612 	sk->sk_rcvbuf      = osk->sk_rcvbuf;
613 	sk->sk_sndbuf      = osk->sk_sndbuf;
614 	sk->sk_state       = TCP_ESTABLISHED;
615 	sk->sk_backlog_rcv = osk->sk_backlog_rcv;
616 	sock_copy_flags(sk, osk);
617 
618 	ox25 = x25_sk(osk);
619 	x25->t21        = ox25->t21;
620 	x25->t22        = ox25->t22;
621 	x25->t23        = ox25->t23;
622 	x25->t2         = ox25->t2;
623 	x25->flags	= ox25->flags;
624 	x25->facilities = ox25->facilities;
625 	x25->dte_facilities = ox25->dte_facilities;
626 	x25->cudmatchlength = ox25->cudmatchlength;
627 
628 	clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
629 	x25_init_timers(sk);
630 out:
631 	return sk;
632 }
633 
634 static int x25_release(struct socket *sock)
635 {
636 	struct sock *sk = sock->sk;
637 	struct x25_sock *x25;
638 
639 	if (!sk)
640 		return 0;
641 
642 	x25 = x25_sk(sk);
643 
644 	sock_hold(sk);
645 	lock_sock(sk);
646 	switch (x25->state) {
647 
648 		case X25_STATE_0:
649 		case X25_STATE_2:
650 			x25_disconnect(sk, 0, 0, 0);
651 			__x25_destroy_socket(sk);
652 			goto out;
653 
654 		case X25_STATE_1:
655 		case X25_STATE_3:
656 		case X25_STATE_4:
657 			x25_clear_queues(sk);
658 			x25_write_internal(sk, X25_CLEAR_REQUEST);
659 			x25_start_t23timer(sk);
660 			x25->state = X25_STATE_2;
661 			sk->sk_state	= TCP_CLOSE;
662 			sk->sk_shutdown	|= SEND_SHUTDOWN;
663 			sk->sk_state_change(sk);
664 			sock_set_flag(sk, SOCK_DEAD);
665 			sock_set_flag(sk, SOCK_DESTROY);
666 			break;
667 	}
668 
669 	sock_orphan(sk);
670 out:
671 	release_sock(sk);
672 	sock_put(sk);
673 	return 0;
674 }
675 
676 static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
677 {
678 	struct sock *sk = sock->sk;
679 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
680 	int len, i, rc = 0;
681 
682 	if (addr_len != sizeof(struct sockaddr_x25) ||
683 	    addr->sx25_family != AF_X25) {
684 		rc = -EINVAL;
685 		goto out;
686 	}
687 
688 	/* check for the null_x25_address */
689 	if (strcmp(addr->sx25_addr.x25_addr, null_x25_address.x25_addr)) {
690 
691 		len = strlen(addr->sx25_addr.x25_addr);
692 		for (i = 0; i < len; i++) {
693 			if (!isdigit(addr->sx25_addr.x25_addr[i])) {
694 				rc = -EINVAL;
695 				goto out;
696 			}
697 		}
698 	}
699 
700 	lock_sock(sk);
701 	if (sock_flag(sk, SOCK_ZAPPED)) {
702 		x25_sk(sk)->source_addr = addr->sx25_addr;
703 		x25_insert_socket(sk);
704 		sock_reset_flag(sk, SOCK_ZAPPED);
705 	} else {
706 		rc = -EINVAL;
707 	}
708 	release_sock(sk);
709 	SOCK_DEBUG(sk, "x25_bind: socket is bound\n");
710 out:
711 	return rc;
712 }
713 
714 static int x25_wait_for_connection_establishment(struct sock *sk)
715 {
716 	DECLARE_WAITQUEUE(wait, current);
717 	int rc;
718 
719 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
720 	for (;;) {
721 		__set_current_state(TASK_INTERRUPTIBLE);
722 		rc = -ERESTARTSYS;
723 		if (signal_pending(current))
724 			break;
725 		rc = sock_error(sk);
726 		if (rc) {
727 			sk->sk_socket->state = SS_UNCONNECTED;
728 			break;
729 		}
730 		rc = 0;
731 		if (sk->sk_state != TCP_ESTABLISHED) {
732 			release_sock(sk);
733 			schedule();
734 			lock_sock(sk);
735 		} else
736 			break;
737 	}
738 	__set_current_state(TASK_RUNNING);
739 	remove_wait_queue(sk_sleep(sk), &wait);
740 	return rc;
741 }
742 
743 static int x25_connect(struct socket *sock, struct sockaddr *uaddr,
744 		       int addr_len, int flags)
745 {
746 	struct sock *sk = sock->sk;
747 	struct x25_sock *x25 = x25_sk(sk);
748 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
749 	struct x25_route *rt;
750 	int rc = 0;
751 
752 	lock_sock(sk);
753 	if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
754 		sock->state = SS_CONNECTED;
755 		goto out; /* Connect completed during a ERESTARTSYS event */
756 	}
757 
758 	rc = -ECONNREFUSED;
759 	if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
760 		sock->state = SS_UNCONNECTED;
761 		goto out;
762 	}
763 
764 	rc = -EISCONN;	/* No reconnect on a seqpacket socket */
765 	if (sk->sk_state == TCP_ESTABLISHED)
766 		goto out;
767 
768 	sk->sk_state   = TCP_CLOSE;
769 	sock->state = SS_UNCONNECTED;
770 
771 	rc = -EINVAL;
772 	if (addr_len != sizeof(struct sockaddr_x25) ||
773 	    addr->sx25_family != AF_X25)
774 		goto out;
775 
776 	rc = -ENETUNREACH;
777 	rt = x25_get_route(&addr->sx25_addr);
778 	if (!rt)
779 		goto out;
780 
781 	x25->neighbour = x25_get_neigh(rt->dev);
782 	if (!x25->neighbour)
783 		goto out_put_route;
784 
785 	x25_limit_facilities(&x25->facilities, x25->neighbour);
786 
787 	x25->lci = x25_new_lci(x25->neighbour);
788 	if (!x25->lci)
789 		goto out_put_neigh;
790 
791 	rc = -EINVAL;
792 	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
793 		goto out_put_neigh;
794 
795 	if (!strcmp(x25->source_addr.x25_addr, null_x25_address.x25_addr))
796 		memset(&x25->source_addr, '\0', X25_ADDR_LEN);
797 
798 	x25->dest_addr = addr->sx25_addr;
799 
800 	/* Move to connecting socket, start sending Connect Requests */
801 	sock->state   = SS_CONNECTING;
802 	sk->sk_state  = TCP_SYN_SENT;
803 
804 	x25->state = X25_STATE_1;
805 
806 	x25_write_internal(sk, X25_CALL_REQUEST);
807 
808 	x25_start_heartbeat(sk);
809 	x25_start_t21timer(sk);
810 
811 	/* Now the loop */
812 	rc = -EINPROGRESS;
813 	if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK))
814 		goto out_put_neigh;
815 
816 	rc = x25_wait_for_connection_establishment(sk);
817 	if (rc)
818 		goto out_put_neigh;
819 
820 	sock->state = SS_CONNECTED;
821 	rc = 0;
822 out_put_neigh:
823 	if (rc) {
824 		read_lock_bh(&x25_list_lock);
825 		x25_neigh_put(x25->neighbour);
826 		x25->neighbour = NULL;
827 		read_unlock_bh(&x25_list_lock);
828 		x25->state = X25_STATE_0;
829 	}
830 out_put_route:
831 	x25_route_put(rt);
832 out:
833 	release_sock(sk);
834 	return rc;
835 }
836 
837 static int x25_wait_for_data(struct sock *sk, long timeout)
838 {
839 	DECLARE_WAITQUEUE(wait, current);
840 	int rc = 0;
841 
842 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
843 	for (;;) {
844 		__set_current_state(TASK_INTERRUPTIBLE);
845 		if (sk->sk_shutdown & RCV_SHUTDOWN)
846 			break;
847 		rc = -ERESTARTSYS;
848 		if (signal_pending(current))
849 			break;
850 		rc = -EAGAIN;
851 		if (!timeout)
852 			break;
853 		rc = 0;
854 		if (skb_queue_empty(&sk->sk_receive_queue)) {
855 			release_sock(sk);
856 			timeout = schedule_timeout(timeout);
857 			lock_sock(sk);
858 		} else
859 			break;
860 	}
861 	__set_current_state(TASK_RUNNING);
862 	remove_wait_queue(sk_sleep(sk), &wait);
863 	return rc;
864 }
865 
866 static int x25_accept(struct socket *sock, struct socket *newsock, int flags,
867 		      bool kern)
868 {
869 	struct sock *sk = sock->sk;
870 	struct sock *newsk;
871 	struct sk_buff *skb;
872 	int rc = -EINVAL;
873 
874 	if (!sk)
875 		goto out;
876 
877 	rc = -EOPNOTSUPP;
878 	if (sk->sk_type != SOCK_SEQPACKET)
879 		goto out;
880 
881 	lock_sock(sk);
882 	rc = -EINVAL;
883 	if (sk->sk_state != TCP_LISTEN)
884 		goto out2;
885 
886 	rc = x25_wait_for_data(sk, sk->sk_rcvtimeo);
887 	if (rc)
888 		goto out2;
889 	skb = skb_dequeue(&sk->sk_receive_queue);
890 	rc = -EINVAL;
891 	if (!skb->sk)
892 		goto out2;
893 	newsk		 = skb->sk;
894 	sock_graft(newsk, newsock);
895 
896 	/* Now attach up the new socket */
897 	skb->sk = NULL;
898 	kfree_skb(skb);
899 	sk->sk_ack_backlog--;
900 	newsock->state = SS_CONNECTED;
901 	rc = 0;
902 out2:
903 	release_sock(sk);
904 out:
905 	return rc;
906 }
907 
908 static int x25_getname(struct socket *sock, struct sockaddr *uaddr,
909 		       int peer)
910 {
911 	struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)uaddr;
912 	struct sock *sk = sock->sk;
913 	struct x25_sock *x25 = x25_sk(sk);
914 	int rc = 0;
915 
916 	if (peer) {
917 		if (sk->sk_state != TCP_ESTABLISHED) {
918 			rc = -ENOTCONN;
919 			goto out;
920 		}
921 		sx25->sx25_addr = x25->dest_addr;
922 	} else
923 		sx25->sx25_addr = x25->source_addr;
924 
925 	sx25->sx25_family = AF_X25;
926 	rc = sizeof(*sx25);
927 
928 out:
929 	return rc;
930 }
931 
932 int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
933 			unsigned int lci)
934 {
935 	struct sock *sk;
936 	struct sock *make;
937 	struct x25_sock *makex25;
938 	struct x25_address source_addr, dest_addr;
939 	struct x25_facilities facilities;
940 	struct x25_dte_facilities dte_facilities;
941 	int len, addr_len, rc;
942 
943 	/*
944 	 *	Remove the LCI and frame type.
945 	 */
946 	skb_pull(skb, X25_STD_MIN_LEN);
947 
948 	/*
949 	 *	Extract the X.25 addresses and convert them to ASCII strings,
950 	 *	and remove them.
951 	 *
952 	 *	Address block is mandatory in call request packets
953 	 */
954 	addr_len = x25_parse_address_block(skb, &source_addr, &dest_addr);
955 	if (addr_len <= 0)
956 		goto out_clear_request;
957 	skb_pull(skb, addr_len);
958 
959 	/*
960 	 *	Get the length of the facilities, skip past them for the moment
961 	 *	get the call user data because this is needed to determine
962 	 *	the correct listener
963 	 *
964 	 *	Facilities length is mandatory in call request packets
965 	 */
966 	if (!pskb_may_pull(skb, 1))
967 		goto out_clear_request;
968 	len = skb->data[0] + 1;
969 	if (!pskb_may_pull(skb, len))
970 		goto out_clear_request;
971 	skb_pull(skb,len);
972 
973 	/*
974 	 *	Ensure that the amount of call user data is valid.
975 	 */
976 	if (skb->len > X25_MAX_CUD_LEN)
977 		goto out_clear_request;
978 
979 	/*
980 	 *	Get all the call user data so it can be used in
981 	 *	x25_find_listener and skb_copy_from_linear_data up ahead.
982 	 */
983 	if (!pskb_may_pull(skb, skb->len))
984 		goto out_clear_request;
985 
986 	/*
987 	 *	Find a listener for the particular address/cud pair.
988 	 */
989 	sk = x25_find_listener(&source_addr,skb);
990 	skb_push(skb,len);
991 
992 	if (sk != NULL && sk_acceptq_is_full(sk)) {
993 		goto out_sock_put;
994 	}
995 
996 	/*
997 	 *	We dont have any listeners for this incoming call.
998 	 *	Try forwarding it.
999 	 */
1000 	if (sk == NULL) {
1001 		skb_push(skb, addr_len + X25_STD_MIN_LEN);
1002 		if (sysctl_x25_forward &&
1003 				x25_forward_call(&dest_addr, nb, skb, lci) > 0)
1004 		{
1005 			/* Call was forwarded, dont process it any more */
1006 			kfree_skb(skb);
1007 			rc = 1;
1008 			goto out;
1009 		} else {
1010 			/* No listeners, can't forward, clear the call */
1011 			goto out_clear_request;
1012 		}
1013 	}
1014 
1015 	/*
1016 	 *	Try to reach a compromise on the requested facilities.
1017 	 */
1018 	len = x25_negotiate_facilities(skb, sk, &facilities, &dte_facilities);
1019 	if (len == -1)
1020 		goto out_sock_put;
1021 
1022 	/*
1023 	 * current neighbour/link might impose additional limits
1024 	 * on certain facilties
1025 	 */
1026 
1027 	x25_limit_facilities(&facilities, nb);
1028 
1029 	/*
1030 	 *	Try to create a new socket.
1031 	 */
1032 	make = x25_make_new(sk);
1033 	if (!make)
1034 		goto out_sock_put;
1035 
1036 	/*
1037 	 *	Remove the facilities
1038 	 */
1039 	skb_pull(skb, len);
1040 
1041 	skb->sk     = make;
1042 	make->sk_state = TCP_ESTABLISHED;
1043 
1044 	makex25 = x25_sk(make);
1045 	makex25->lci           = lci;
1046 	makex25->dest_addr     = dest_addr;
1047 	makex25->source_addr   = source_addr;
1048 	makex25->neighbour     = nb;
1049 	makex25->facilities    = facilities;
1050 	makex25->dte_facilities= dte_facilities;
1051 	makex25->vc_facil_mask = x25_sk(sk)->vc_facil_mask;
1052 	/* ensure no reverse facil on accept */
1053 	makex25->vc_facil_mask &= ~X25_MASK_REVERSE;
1054 	/* ensure no calling address extension on accept */
1055 	makex25->vc_facil_mask &= ~X25_MASK_CALLING_AE;
1056 	makex25->cudmatchlength = x25_sk(sk)->cudmatchlength;
1057 
1058 	/* Normally all calls are accepted immediately */
1059 	if (test_bit(X25_ACCPT_APPRV_FLAG, &makex25->flags)) {
1060 		x25_write_internal(make, X25_CALL_ACCEPTED);
1061 		makex25->state = X25_STATE_3;
1062 	}
1063 
1064 	/*
1065 	 *	Incoming Call User Data.
1066 	 */
1067 	skb_copy_from_linear_data(skb, makex25->calluserdata.cuddata, skb->len);
1068 	makex25->calluserdata.cudlength = skb->len;
1069 
1070 	sk->sk_ack_backlog++;
1071 
1072 	x25_insert_socket(make);
1073 
1074 	skb_queue_head(&sk->sk_receive_queue, skb);
1075 
1076 	x25_start_heartbeat(make);
1077 
1078 	if (!sock_flag(sk, SOCK_DEAD))
1079 		sk->sk_data_ready(sk);
1080 	rc = 1;
1081 	sock_put(sk);
1082 out:
1083 	return rc;
1084 out_sock_put:
1085 	sock_put(sk);
1086 out_clear_request:
1087 	rc = 0;
1088 	x25_transmit_clear_request(nb, lci, 0x01);
1089 	goto out;
1090 }
1091 
1092 static int x25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1093 {
1094 	struct sock *sk = sock->sk;
1095 	struct x25_sock *x25 = x25_sk(sk);
1096 	DECLARE_SOCKADDR(struct sockaddr_x25 *, usx25, msg->msg_name);
1097 	struct sockaddr_x25 sx25;
1098 	struct sk_buff *skb;
1099 	unsigned char *asmptr;
1100 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1101 	size_t size;
1102 	int qbit = 0, rc = -EINVAL;
1103 
1104 	lock_sock(sk);
1105 	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_OOB|MSG_EOR|MSG_CMSG_COMPAT))
1106 		goto out;
1107 
1108 	/* we currently don't support segmented records at the user interface */
1109 	if (!(msg->msg_flags & (MSG_EOR|MSG_OOB)))
1110 		goto out;
1111 
1112 	rc = -EADDRNOTAVAIL;
1113 	if (sock_flag(sk, SOCK_ZAPPED))
1114 		goto out;
1115 
1116 	rc = -EPIPE;
1117 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1118 		send_sig(SIGPIPE, current, 0);
1119 		goto out;
1120 	}
1121 
1122 	rc = -ENETUNREACH;
1123 	if (!x25->neighbour)
1124 		goto out;
1125 
1126 	if (usx25) {
1127 		rc = -EINVAL;
1128 		if (msg->msg_namelen < sizeof(sx25))
1129 			goto out;
1130 		memcpy(&sx25, usx25, sizeof(sx25));
1131 		rc = -EISCONN;
1132 		if (strcmp(x25->dest_addr.x25_addr, sx25.sx25_addr.x25_addr))
1133 			goto out;
1134 		rc = -EINVAL;
1135 		if (sx25.sx25_family != AF_X25)
1136 			goto out;
1137 	} else {
1138 		/*
1139 		 *	FIXME 1003.1g - if the socket is like this because
1140 		 *	it has become closed (not started closed) we ought
1141 		 *	to SIGPIPE, EPIPE;
1142 		 */
1143 		rc = -ENOTCONN;
1144 		if (sk->sk_state != TCP_ESTABLISHED)
1145 			goto out;
1146 
1147 		sx25.sx25_family = AF_X25;
1148 		sx25.sx25_addr   = x25->dest_addr;
1149 	}
1150 
1151 	/* Sanity check the packet size */
1152 	if (len > 65535) {
1153 		rc = -EMSGSIZE;
1154 		goto out;
1155 	}
1156 
1157 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: Addresses built.\n");
1158 
1159 	/* Build a packet */
1160 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: building packet.\n");
1161 
1162 	if ((msg->msg_flags & MSG_OOB) && len > 32)
1163 		len = 32;
1164 
1165 	size = len + X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
1166 
1167 	release_sock(sk);
1168 	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
1169 	lock_sock(sk);
1170 	if (!skb)
1171 		goto out;
1172 	X25_SKB_CB(skb)->flags = msg->msg_flags;
1173 
1174 	skb_reserve(skb, X25_MAX_L2_LEN + X25_EXT_MIN_LEN);
1175 
1176 	/*
1177 	 *	Put the data on the end
1178 	 */
1179 	SOCK_DEBUG(sk, "x25_sendmsg: Copying user data\n");
1180 
1181 	skb_reset_transport_header(skb);
1182 	skb_put(skb, len);
1183 
1184 	rc = memcpy_from_msg(skb_transport_header(skb), msg, len);
1185 	if (rc)
1186 		goto out_kfree_skb;
1187 
1188 	/*
1189 	 *	If the Q BIT Include socket option is in force, the first
1190 	 *	byte of the user data is the logical value of the Q Bit.
1191 	 */
1192 	if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1193 		if (!pskb_may_pull(skb, 1))
1194 			goto out_kfree_skb;
1195 
1196 		qbit = skb->data[0];
1197 		skb_pull(skb, 1);
1198 	}
1199 
1200 	/*
1201 	 *	Push down the X.25 header
1202 	 */
1203 	SOCK_DEBUG(sk, "x25_sendmsg: Building X.25 Header.\n");
1204 
1205 	if (msg->msg_flags & MSG_OOB) {
1206 		if (x25->neighbour->extended) {
1207 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1208 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1209 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1210 			*asmptr++ = X25_INTERRUPT;
1211 		} else {
1212 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1213 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1214 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1215 			*asmptr++ = X25_INTERRUPT;
1216 		}
1217 	} else {
1218 		if (x25->neighbour->extended) {
1219 			/* Build an Extended X.25 header */
1220 			asmptr    = skb_push(skb, X25_EXT_MIN_LEN);
1221 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1222 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1223 			*asmptr++ = X25_DATA;
1224 			*asmptr++ = X25_DATA;
1225 		} else {
1226 			/* Build an Standard X.25 header */
1227 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1228 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1229 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1230 			*asmptr++ = X25_DATA;
1231 		}
1232 
1233 		if (qbit)
1234 			skb->data[0] |= X25_Q_BIT;
1235 	}
1236 
1237 	SOCK_DEBUG(sk, "x25_sendmsg: Built header.\n");
1238 	SOCK_DEBUG(sk, "x25_sendmsg: Transmitting buffer\n");
1239 
1240 	rc = -ENOTCONN;
1241 	if (sk->sk_state != TCP_ESTABLISHED)
1242 		goto out_kfree_skb;
1243 
1244 	if (msg->msg_flags & MSG_OOB)
1245 		skb_queue_tail(&x25->interrupt_out_queue, skb);
1246 	else {
1247 		rc = x25_output(sk, skb);
1248 		len = rc;
1249 		if (rc < 0)
1250 			kfree_skb(skb);
1251 		else if (test_bit(X25_Q_BIT_FLAG, &x25->flags))
1252 			len++;
1253 	}
1254 
1255 	x25_kick(sk);
1256 	rc = len;
1257 out:
1258 	release_sock(sk);
1259 	return rc;
1260 out_kfree_skb:
1261 	kfree_skb(skb);
1262 	goto out;
1263 }
1264 
1265 
1266 static int x25_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1267 		       int flags)
1268 {
1269 	struct sock *sk = sock->sk;
1270 	struct x25_sock *x25 = x25_sk(sk);
1271 	DECLARE_SOCKADDR(struct sockaddr_x25 *, sx25, msg->msg_name);
1272 	size_t copied;
1273 	int qbit, header_len;
1274 	struct sk_buff *skb;
1275 	unsigned char *asmptr;
1276 	int rc = -ENOTCONN;
1277 
1278 	lock_sock(sk);
1279 
1280 	if (x25->neighbour == NULL)
1281 		goto out;
1282 
1283 	header_len = x25->neighbour->extended ?
1284 		X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
1285 
1286 	/*
1287 	 * This works for seqpacket too. The receiver has ordered the queue for
1288 	 * us! We do one quick check first though
1289 	 */
1290 	if (sk->sk_state != TCP_ESTABLISHED)
1291 		goto out;
1292 
1293 	if (flags & MSG_OOB) {
1294 		rc = -EINVAL;
1295 		if (sock_flag(sk, SOCK_URGINLINE) ||
1296 		    !skb_peek(&x25->interrupt_in_queue))
1297 			goto out;
1298 
1299 		skb = skb_dequeue(&x25->interrupt_in_queue);
1300 
1301 		if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
1302 			goto out_free_dgram;
1303 
1304 		skb_pull(skb, X25_STD_MIN_LEN);
1305 
1306 		/*
1307 		 *	No Q bit information on Interrupt data.
1308 		 */
1309 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1310 			asmptr  = skb_push(skb, 1);
1311 			*asmptr = 0x00;
1312 		}
1313 
1314 		msg->msg_flags |= MSG_OOB;
1315 	} else {
1316 		/* Now we can treat all alike */
1317 		release_sock(sk);
1318 		skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1319 					flags & MSG_DONTWAIT, &rc);
1320 		lock_sock(sk);
1321 		if (!skb)
1322 			goto out;
1323 
1324 		if (!pskb_may_pull(skb, header_len))
1325 			goto out_free_dgram;
1326 
1327 		qbit = (skb->data[0] & X25_Q_BIT) == X25_Q_BIT;
1328 
1329 		skb_pull(skb, header_len);
1330 
1331 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1332 			asmptr  = skb_push(skb, 1);
1333 			*asmptr = qbit;
1334 		}
1335 	}
1336 
1337 	skb_reset_transport_header(skb);
1338 	copied = skb->len;
1339 
1340 	if (copied > size) {
1341 		copied = size;
1342 		msg->msg_flags |= MSG_TRUNC;
1343 	}
1344 
1345 	/* Currently, each datagram always contains a complete record */
1346 	msg->msg_flags |= MSG_EOR;
1347 
1348 	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
1349 	if (rc)
1350 		goto out_free_dgram;
1351 
1352 	if (sx25) {
1353 		sx25->sx25_family = AF_X25;
1354 		sx25->sx25_addr   = x25->dest_addr;
1355 		msg->msg_namelen = sizeof(*sx25);
1356 	}
1357 
1358 	x25_check_rbuf(sk);
1359 	rc = copied;
1360 out_free_dgram:
1361 	skb_free_datagram(sk, skb);
1362 out:
1363 	release_sock(sk);
1364 	return rc;
1365 }
1366 
1367 
1368 static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1369 {
1370 	struct sock *sk = sock->sk;
1371 	struct x25_sock *x25 = x25_sk(sk);
1372 	void __user *argp = (void __user *)arg;
1373 	int rc;
1374 
1375 	switch (cmd) {
1376 	case TIOCOUTQ: {
1377 		int amount;
1378 
1379 		amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1380 		if (amount < 0)
1381 			amount = 0;
1382 		rc = put_user(amount, (unsigned int __user *)argp);
1383 		break;
1384 	}
1385 
1386 	case TIOCINQ: {
1387 		struct sk_buff *skb;
1388 		int amount = 0;
1389 		/*
1390 		 * These two are safe on a single CPU system as
1391 		 * only user tasks fiddle here
1392 		 */
1393 		lock_sock(sk);
1394 		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1395 			amount = skb->len;
1396 		release_sock(sk);
1397 		rc = put_user(amount, (unsigned int __user *)argp);
1398 		break;
1399 	}
1400 
1401 	case SIOCGSTAMP:
1402 		rc = -EINVAL;
1403 		if (sk)
1404 			rc = sock_get_timestamp(sk,
1405 						(struct timeval __user *)argp);
1406 		break;
1407 	case SIOCGSTAMPNS:
1408 		rc = -EINVAL;
1409 		if (sk)
1410 			rc = sock_get_timestampns(sk,
1411 					(struct timespec __user *)argp);
1412 		break;
1413 	case SIOCGIFADDR:
1414 	case SIOCSIFADDR:
1415 	case SIOCGIFDSTADDR:
1416 	case SIOCSIFDSTADDR:
1417 	case SIOCGIFBRDADDR:
1418 	case SIOCSIFBRDADDR:
1419 	case SIOCGIFNETMASK:
1420 	case SIOCSIFNETMASK:
1421 	case SIOCGIFMETRIC:
1422 	case SIOCSIFMETRIC:
1423 		rc = -EINVAL;
1424 		break;
1425 	case SIOCADDRT:
1426 	case SIOCDELRT:
1427 		rc = -EPERM;
1428 		if (!capable(CAP_NET_ADMIN))
1429 			break;
1430 		rc = x25_route_ioctl(cmd, argp);
1431 		break;
1432 	case SIOCX25GSUBSCRIP:
1433 		rc = x25_subscr_ioctl(cmd, argp);
1434 		break;
1435 	case SIOCX25SSUBSCRIP:
1436 		rc = -EPERM;
1437 		if (!capable(CAP_NET_ADMIN))
1438 			break;
1439 		rc = x25_subscr_ioctl(cmd, argp);
1440 		break;
1441 	case SIOCX25GFACILITIES: {
1442 		lock_sock(sk);
1443 		rc = copy_to_user(argp, &x25->facilities,
1444 				  sizeof(x25->facilities))
1445 			? -EFAULT : 0;
1446 		release_sock(sk);
1447 		break;
1448 	}
1449 
1450 	case SIOCX25SFACILITIES: {
1451 		struct x25_facilities facilities;
1452 		rc = -EFAULT;
1453 		if (copy_from_user(&facilities, argp, sizeof(facilities)))
1454 			break;
1455 		rc = -EINVAL;
1456 		lock_sock(sk);
1457 		if (sk->sk_state != TCP_LISTEN &&
1458 		    sk->sk_state != TCP_CLOSE)
1459 			goto out_fac_release;
1460 		if (facilities.pacsize_in < X25_PS16 ||
1461 		    facilities.pacsize_in > X25_PS4096)
1462 			goto out_fac_release;
1463 		if (facilities.pacsize_out < X25_PS16 ||
1464 		    facilities.pacsize_out > X25_PS4096)
1465 			goto out_fac_release;
1466 		if (facilities.winsize_in < 1 ||
1467 		    facilities.winsize_in > 127)
1468 			goto out_fac_release;
1469 		if (facilities.throughput) {
1470 			int out = facilities.throughput & 0xf0;
1471 			int in  = facilities.throughput & 0x0f;
1472 			if (!out)
1473 				facilities.throughput |=
1474 					X25_DEFAULT_THROUGHPUT << 4;
1475 			else if (out < 0x30 || out > 0xD0)
1476 				goto out_fac_release;
1477 			if (!in)
1478 				facilities.throughput |=
1479 					X25_DEFAULT_THROUGHPUT;
1480 			else if (in < 0x03 || in > 0x0D)
1481 				goto out_fac_release;
1482 		}
1483 		if (facilities.reverse &&
1484 		    (facilities.reverse & 0x81) != 0x81)
1485 			goto out_fac_release;
1486 		x25->facilities = facilities;
1487 		rc = 0;
1488 out_fac_release:
1489 		release_sock(sk);
1490 		break;
1491 	}
1492 
1493 	case SIOCX25GDTEFACILITIES: {
1494 		lock_sock(sk);
1495 		rc = copy_to_user(argp, &x25->dte_facilities,
1496 				  sizeof(x25->dte_facilities));
1497 		release_sock(sk);
1498 		if (rc)
1499 			rc = -EFAULT;
1500 		break;
1501 	}
1502 
1503 	case SIOCX25SDTEFACILITIES: {
1504 		struct x25_dte_facilities dtefacs;
1505 		rc = -EFAULT;
1506 		if (copy_from_user(&dtefacs, argp, sizeof(dtefacs)))
1507 			break;
1508 		rc = -EINVAL;
1509 		lock_sock(sk);
1510 		if (sk->sk_state != TCP_LISTEN &&
1511 		    sk->sk_state != TCP_CLOSE)
1512 			goto out_dtefac_release;
1513 		if (dtefacs.calling_len > X25_MAX_AE_LEN)
1514 			goto out_dtefac_release;
1515 		if (dtefacs.called_len > X25_MAX_AE_LEN)
1516 			goto out_dtefac_release;
1517 		x25->dte_facilities = dtefacs;
1518 		rc = 0;
1519 out_dtefac_release:
1520 		release_sock(sk);
1521 		break;
1522 	}
1523 
1524 	case SIOCX25GCALLUSERDATA: {
1525 		lock_sock(sk);
1526 		rc = copy_to_user(argp, &x25->calluserdata,
1527 				  sizeof(x25->calluserdata))
1528 			? -EFAULT : 0;
1529 		release_sock(sk);
1530 		break;
1531 	}
1532 
1533 	case SIOCX25SCALLUSERDATA: {
1534 		struct x25_calluserdata calluserdata;
1535 
1536 		rc = -EFAULT;
1537 		if (copy_from_user(&calluserdata, argp, sizeof(calluserdata)))
1538 			break;
1539 		rc = -EINVAL;
1540 		if (calluserdata.cudlength > X25_MAX_CUD_LEN)
1541 			break;
1542 		lock_sock(sk);
1543 		x25->calluserdata = calluserdata;
1544 		release_sock(sk);
1545 		rc = 0;
1546 		break;
1547 	}
1548 
1549 	case SIOCX25GCAUSEDIAG: {
1550 		lock_sock(sk);
1551 		rc = copy_to_user(argp, &x25->causediag, sizeof(x25->causediag))
1552 			? -EFAULT : 0;
1553 		release_sock(sk);
1554 		break;
1555 	}
1556 
1557 	case SIOCX25SCAUSEDIAG: {
1558 		struct x25_causediag causediag;
1559 		rc = -EFAULT;
1560 		if (copy_from_user(&causediag, argp, sizeof(causediag)))
1561 			break;
1562 		lock_sock(sk);
1563 		x25->causediag = causediag;
1564 		release_sock(sk);
1565 		rc = 0;
1566 		break;
1567 
1568 	}
1569 
1570 	case SIOCX25SCUDMATCHLEN: {
1571 		struct x25_subaddr sub_addr;
1572 		rc = -EINVAL;
1573 		lock_sock(sk);
1574 		if(sk->sk_state != TCP_CLOSE)
1575 			goto out_cud_release;
1576 		rc = -EFAULT;
1577 		if (copy_from_user(&sub_addr, argp,
1578 				   sizeof(sub_addr)))
1579 			goto out_cud_release;
1580 		rc = -EINVAL;
1581 		if (sub_addr.cudmatchlength > X25_MAX_CUD_LEN)
1582 			goto out_cud_release;
1583 		x25->cudmatchlength = sub_addr.cudmatchlength;
1584 		rc = 0;
1585 out_cud_release:
1586 		release_sock(sk);
1587 		break;
1588 	}
1589 
1590 	case SIOCX25CALLACCPTAPPRV: {
1591 		rc = -EINVAL;
1592 		lock_sock(sk);
1593 		if (sk->sk_state == TCP_CLOSE) {
1594 			clear_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);
1595 			rc = 0;
1596 		}
1597 		release_sock(sk);
1598 		break;
1599 	}
1600 
1601 	case SIOCX25SENDCALLACCPT:  {
1602 		rc = -EINVAL;
1603 		lock_sock(sk);
1604 		if (sk->sk_state != TCP_ESTABLISHED)
1605 			goto out_sendcallaccpt_release;
1606 		/* must call accptapprv above */
1607 		if (test_bit(X25_ACCPT_APPRV_FLAG, &x25->flags))
1608 			goto out_sendcallaccpt_release;
1609 		x25_write_internal(sk, X25_CALL_ACCEPTED);
1610 		x25->state = X25_STATE_3;
1611 		rc = 0;
1612 out_sendcallaccpt_release:
1613 		release_sock(sk);
1614 		break;
1615 	}
1616 
1617 	default:
1618 		rc = -ENOIOCTLCMD;
1619 		break;
1620 	}
1621 
1622 	return rc;
1623 }
1624 
1625 static const struct net_proto_family x25_family_ops = {
1626 	.family =	AF_X25,
1627 	.create =	x25_create,
1628 	.owner	=	THIS_MODULE,
1629 };
1630 
1631 #ifdef CONFIG_COMPAT
1632 static int compat_x25_subscr_ioctl(unsigned int cmd,
1633 		struct compat_x25_subscrip_struct __user *x25_subscr32)
1634 {
1635 	struct compat_x25_subscrip_struct x25_subscr;
1636 	struct x25_neigh *nb;
1637 	struct net_device *dev;
1638 	int rc = -EINVAL;
1639 
1640 	rc = -EFAULT;
1641 	if (copy_from_user(&x25_subscr, x25_subscr32, sizeof(*x25_subscr32)))
1642 		goto out;
1643 
1644 	rc = -EINVAL;
1645 	dev = x25_dev_get(x25_subscr.device);
1646 	if (dev == NULL)
1647 		goto out;
1648 
1649 	nb = x25_get_neigh(dev);
1650 	if (nb == NULL)
1651 		goto out_dev_put;
1652 
1653 	dev_put(dev);
1654 
1655 	if (cmd == SIOCX25GSUBSCRIP) {
1656 		read_lock_bh(&x25_neigh_list_lock);
1657 		x25_subscr.extended = nb->extended;
1658 		x25_subscr.global_facil_mask = nb->global_facil_mask;
1659 		read_unlock_bh(&x25_neigh_list_lock);
1660 		rc = copy_to_user(x25_subscr32, &x25_subscr,
1661 				sizeof(*x25_subscr32)) ? -EFAULT : 0;
1662 	} else {
1663 		rc = -EINVAL;
1664 		if (x25_subscr.extended == 0 || x25_subscr.extended == 1) {
1665 			rc = 0;
1666 			write_lock_bh(&x25_neigh_list_lock);
1667 			nb->extended = x25_subscr.extended;
1668 			nb->global_facil_mask = x25_subscr.global_facil_mask;
1669 			write_unlock_bh(&x25_neigh_list_lock);
1670 		}
1671 	}
1672 	x25_neigh_put(nb);
1673 out:
1674 	return rc;
1675 out_dev_put:
1676 	dev_put(dev);
1677 	goto out;
1678 }
1679 
1680 static int compat_x25_ioctl(struct socket *sock, unsigned int cmd,
1681 				unsigned long arg)
1682 {
1683 	void __user *argp = compat_ptr(arg);
1684 	struct sock *sk = sock->sk;
1685 
1686 	int rc = -ENOIOCTLCMD;
1687 
1688 	switch(cmd) {
1689 	case TIOCOUTQ:
1690 	case TIOCINQ:
1691 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1692 		break;
1693 	case SIOCGSTAMP:
1694 		rc = -EINVAL;
1695 		if (sk)
1696 			rc = compat_sock_get_timestamp(sk,
1697 					(struct timeval __user*)argp);
1698 		break;
1699 	case SIOCGSTAMPNS:
1700 		rc = -EINVAL;
1701 		if (sk)
1702 			rc = compat_sock_get_timestampns(sk,
1703 					(struct timespec __user*)argp);
1704 		break;
1705 	case SIOCGIFADDR:
1706 	case SIOCSIFADDR:
1707 	case SIOCGIFDSTADDR:
1708 	case SIOCSIFDSTADDR:
1709 	case SIOCGIFBRDADDR:
1710 	case SIOCSIFBRDADDR:
1711 	case SIOCGIFNETMASK:
1712 	case SIOCSIFNETMASK:
1713 	case SIOCGIFMETRIC:
1714 	case SIOCSIFMETRIC:
1715 		rc = -EINVAL;
1716 		break;
1717 	case SIOCADDRT:
1718 	case SIOCDELRT:
1719 		rc = -EPERM;
1720 		if (!capable(CAP_NET_ADMIN))
1721 			break;
1722 		rc = x25_route_ioctl(cmd, argp);
1723 		break;
1724 	case SIOCX25GSUBSCRIP:
1725 		rc = compat_x25_subscr_ioctl(cmd, argp);
1726 		break;
1727 	case SIOCX25SSUBSCRIP:
1728 		rc = -EPERM;
1729 		if (!capable(CAP_NET_ADMIN))
1730 			break;
1731 		rc = compat_x25_subscr_ioctl(cmd, argp);
1732 		break;
1733 	case SIOCX25GFACILITIES:
1734 	case SIOCX25SFACILITIES:
1735 	case SIOCX25GDTEFACILITIES:
1736 	case SIOCX25SDTEFACILITIES:
1737 	case SIOCX25GCALLUSERDATA:
1738 	case SIOCX25SCALLUSERDATA:
1739 	case SIOCX25GCAUSEDIAG:
1740 	case SIOCX25SCAUSEDIAG:
1741 	case SIOCX25SCUDMATCHLEN:
1742 	case SIOCX25CALLACCPTAPPRV:
1743 	case SIOCX25SENDCALLACCPT:
1744 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1745 		break;
1746 	default:
1747 		rc = -ENOIOCTLCMD;
1748 		break;
1749 	}
1750 	return rc;
1751 }
1752 #endif
1753 
1754 static const struct proto_ops x25_proto_ops = {
1755 	.family =	AF_X25,
1756 	.owner =	THIS_MODULE,
1757 	.release =	x25_release,
1758 	.bind =		x25_bind,
1759 	.connect =	x25_connect,
1760 	.socketpair =	sock_no_socketpair,
1761 	.accept =	x25_accept,
1762 	.getname =	x25_getname,
1763 	.poll =		datagram_poll,
1764 	.ioctl =	x25_ioctl,
1765 #ifdef CONFIG_COMPAT
1766 	.compat_ioctl = compat_x25_ioctl,
1767 #endif
1768 	.listen =	x25_listen,
1769 	.shutdown =	sock_no_shutdown,
1770 	.setsockopt =	x25_setsockopt,
1771 	.getsockopt =	x25_getsockopt,
1772 	.sendmsg =	x25_sendmsg,
1773 	.recvmsg =	x25_recvmsg,
1774 	.mmap =		sock_no_mmap,
1775 	.sendpage =	sock_no_sendpage,
1776 };
1777 
1778 static struct packet_type x25_packet_type __read_mostly = {
1779 	.type =	cpu_to_be16(ETH_P_X25),
1780 	.func =	x25_lapb_receive_frame,
1781 };
1782 
1783 static struct notifier_block x25_dev_notifier = {
1784 	.notifier_call = x25_device_event,
1785 };
1786 
1787 void x25_kill_by_neigh(struct x25_neigh *nb)
1788 {
1789 	struct sock *s;
1790 
1791 	write_lock_bh(&x25_list_lock);
1792 
1793 	sk_for_each(s, &x25_list)
1794 		if (x25_sk(s)->neighbour == nb)
1795 			x25_disconnect(s, ENETUNREACH, 0, 0);
1796 
1797 	write_unlock_bh(&x25_list_lock);
1798 
1799 	/* Remove any related forwards */
1800 	x25_clear_forward_by_dev(nb->dev);
1801 }
1802 
1803 static int __init x25_init(void)
1804 {
1805 	int rc;
1806 
1807 	rc = proto_register(&x25_proto, 0);
1808 	if (rc)
1809 		goto out;
1810 
1811 	rc = sock_register(&x25_family_ops);
1812 	if (rc)
1813 		goto out_proto;
1814 
1815 	dev_add_pack(&x25_packet_type);
1816 
1817 	rc = register_netdevice_notifier(&x25_dev_notifier);
1818 	if (rc)
1819 		goto out_sock;
1820 
1821 	rc = x25_register_sysctl();
1822 	if (rc)
1823 		goto out_dev;
1824 
1825 	rc = x25_proc_init();
1826 	if (rc)
1827 		goto out_sysctl;
1828 
1829 	pr_info("Linux Version 0.2\n");
1830 
1831 out:
1832 	return rc;
1833 out_sysctl:
1834 	x25_unregister_sysctl();
1835 out_dev:
1836 	unregister_netdevice_notifier(&x25_dev_notifier);
1837 out_sock:
1838 	dev_remove_pack(&x25_packet_type);
1839 	sock_unregister(AF_X25);
1840 out_proto:
1841 	proto_unregister(&x25_proto);
1842 	goto out;
1843 }
1844 module_init(x25_init);
1845 
1846 static void __exit x25_exit(void)
1847 {
1848 	x25_proc_exit();
1849 	x25_link_free();
1850 	x25_route_free();
1851 
1852 	x25_unregister_sysctl();
1853 
1854 	unregister_netdevice_notifier(&x25_dev_notifier);
1855 
1856 	dev_remove_pack(&x25_packet_type);
1857 
1858 	sock_unregister(AF_X25);
1859 	proto_unregister(&x25_proto);
1860 }
1861 module_exit(x25_exit);
1862 
1863 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
1864 MODULE_DESCRIPTION("The X.25 Packet Layer network layer protocol");
1865 MODULE_LICENSE("GPL");
1866 MODULE_ALIAS_NETPROTO(PF_X25);
1867