xref: /openbmc/linux/net/x25/af_x25.c (revision 2fa49589)
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 	read_lock_bh(&x25_list_lock);
356 
357 	while ((sk = __x25_find_socket(lci, nb)) != NULL) {
358 		sock_put(sk);
359 		if (++lci == 4096) {
360 			lci = 0;
361 			break;
362 		}
363 	}
364 
365 	read_unlock_bh(&x25_list_lock);
366 	return lci;
367 }
368 
369 /*
370  *	Deferred destroy.
371  */
372 static void __x25_destroy_socket(struct sock *);
373 
374 /*
375  *	handler for deferred kills.
376  */
377 static void x25_destroy_timer(struct timer_list *t)
378 {
379 	struct sock *sk = from_timer(sk, t, sk_timer);
380 
381 	x25_destroy_socket_from_timer(sk);
382 }
383 
384 /*
385  *	This is called from user mode and the timers. Thus it protects itself
386  *	against interrupt users but doesn't worry about being called during
387  *	work. Once it is removed from the queue no interrupt or bottom half
388  *	will touch it and we are (fairly 8-) ) safe.
389  *	Not static as it's used by the timer
390  */
391 static void __x25_destroy_socket(struct sock *sk)
392 {
393 	struct sk_buff *skb;
394 
395 	x25_stop_heartbeat(sk);
396 	x25_stop_timer(sk);
397 
398 	x25_remove_socket(sk);
399 	x25_clear_queues(sk);		/* Flush the queues */
400 
401 	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
402 		if (skb->sk != sk) {		/* A pending connection */
403 			/*
404 			 * Queue the unaccepted socket for death
405 			 */
406 			skb->sk->sk_state = TCP_LISTEN;
407 			sock_set_flag(skb->sk, SOCK_DEAD);
408 			x25_start_heartbeat(skb->sk);
409 			x25_sk(skb->sk)->state = X25_STATE_0;
410 		}
411 
412 		kfree_skb(skb);
413 	}
414 
415 	if (sk_has_allocations(sk)) {
416 		/* Defer: outstanding buffers */
417 		sk->sk_timer.expires  = jiffies + 10 * HZ;
418 		sk->sk_timer.function = x25_destroy_timer;
419 		add_timer(&sk->sk_timer);
420 	} else {
421 		/* drop last reference so sock_put will free */
422 		__sock_put(sk);
423 	}
424 }
425 
426 void x25_destroy_socket_from_timer(struct sock *sk)
427 {
428 	sock_hold(sk);
429 	bh_lock_sock(sk);
430 	__x25_destroy_socket(sk);
431 	bh_unlock_sock(sk);
432 	sock_put(sk);
433 }
434 
435 /*
436  *	Handling for system calls applied via the various interfaces to a
437  *	X.25 socket object.
438  */
439 
440 static int x25_setsockopt(struct socket *sock, int level, int optname,
441 			  char __user *optval, unsigned int optlen)
442 {
443 	int opt;
444 	struct sock *sk = sock->sk;
445 	int rc = -ENOPROTOOPT;
446 
447 	if (level != SOL_X25 || optname != X25_QBITINCL)
448 		goto out;
449 
450 	rc = -EINVAL;
451 	if (optlen < sizeof(int))
452 		goto out;
453 
454 	rc = -EFAULT;
455 	if (get_user(opt, (int __user *)optval))
456 		goto out;
457 
458 	if (opt)
459 		set_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
460 	else
461 		clear_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
462 	rc = 0;
463 out:
464 	return rc;
465 }
466 
467 static int x25_getsockopt(struct socket *sock, int level, int optname,
468 			  char __user *optval, int __user *optlen)
469 {
470 	struct sock *sk = sock->sk;
471 	int val, len, rc = -ENOPROTOOPT;
472 
473 	if (level != SOL_X25 || optname != X25_QBITINCL)
474 		goto out;
475 
476 	rc = -EFAULT;
477 	if (get_user(len, optlen))
478 		goto out;
479 
480 	len = min_t(unsigned int, len, sizeof(int));
481 
482 	rc = -EINVAL;
483 	if (len < 0)
484 		goto out;
485 
486 	rc = -EFAULT;
487 	if (put_user(len, optlen))
488 		goto out;
489 
490 	val = test_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
491 	rc = copy_to_user(optval, &val, len) ? -EFAULT : 0;
492 out:
493 	return rc;
494 }
495 
496 static int x25_listen(struct socket *sock, int backlog)
497 {
498 	struct sock *sk = sock->sk;
499 	int rc = -EOPNOTSUPP;
500 
501 	lock_sock(sk);
502 	if (sk->sk_state != TCP_LISTEN) {
503 		memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN);
504 		sk->sk_max_ack_backlog = backlog;
505 		sk->sk_state           = TCP_LISTEN;
506 		rc = 0;
507 	}
508 	release_sock(sk);
509 
510 	return rc;
511 }
512 
513 static struct proto x25_proto = {
514 	.name	  = "X25",
515 	.owner	  = THIS_MODULE,
516 	.obj_size = sizeof(struct x25_sock),
517 };
518 
519 static struct sock *x25_alloc_socket(struct net *net, int kern)
520 {
521 	struct x25_sock *x25;
522 	struct sock *sk = sk_alloc(net, AF_X25, GFP_ATOMIC, &x25_proto, kern);
523 
524 	if (!sk)
525 		goto out;
526 
527 	sock_init_data(NULL, sk);
528 
529 	x25 = x25_sk(sk);
530 	skb_queue_head_init(&x25->ack_queue);
531 	skb_queue_head_init(&x25->fragment_queue);
532 	skb_queue_head_init(&x25->interrupt_in_queue);
533 	skb_queue_head_init(&x25->interrupt_out_queue);
534 out:
535 	return sk;
536 }
537 
538 static int x25_create(struct net *net, struct socket *sock, int protocol,
539 		      int kern)
540 {
541 	struct sock *sk;
542 	struct x25_sock *x25;
543 	int rc = -EAFNOSUPPORT;
544 
545 	if (!net_eq(net, &init_net))
546 		goto out;
547 
548 	rc = -ESOCKTNOSUPPORT;
549 	if (sock->type != SOCK_SEQPACKET)
550 		goto out;
551 
552 	rc = -EINVAL;
553 	if (protocol)
554 		goto out;
555 
556 	rc = -ENOBUFS;
557 	if ((sk = x25_alloc_socket(net, kern)) == NULL)
558 		goto out;
559 
560 	x25 = x25_sk(sk);
561 
562 	sock_init_data(sock, sk);
563 
564 	x25_init_timers(sk);
565 
566 	sock->ops    = &x25_proto_ops;
567 	sk->sk_protocol = protocol;
568 	sk->sk_backlog_rcv = x25_backlog_rcv;
569 
570 	x25->t21   = sysctl_x25_call_request_timeout;
571 	x25->t22   = sysctl_x25_reset_request_timeout;
572 	x25->t23   = sysctl_x25_clear_request_timeout;
573 	x25->t2    = sysctl_x25_ack_holdback_timeout;
574 	x25->state = X25_STATE_0;
575 	x25->cudmatchlength = 0;
576 	set_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);	/* normally no cud  */
577 							/* on call accept   */
578 
579 	x25->facilities.winsize_in  = X25_DEFAULT_WINDOW_SIZE;
580 	x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
581 	x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
582 	x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
583 	x25->facilities.throughput  = 0;	/* by default don't negotiate
584 						   throughput */
585 	x25->facilities.reverse     = X25_DEFAULT_REVERSE;
586 	x25->dte_facilities.calling_len = 0;
587 	x25->dte_facilities.called_len = 0;
588 	memset(x25->dte_facilities.called_ae, '\0',
589 			sizeof(x25->dte_facilities.called_ae));
590 	memset(x25->dte_facilities.calling_ae, '\0',
591 			sizeof(x25->dte_facilities.calling_ae));
592 
593 	rc = 0;
594 out:
595 	return rc;
596 }
597 
598 static struct sock *x25_make_new(struct sock *osk)
599 {
600 	struct sock *sk = NULL;
601 	struct x25_sock *x25, *ox25;
602 
603 	if (osk->sk_type != SOCK_SEQPACKET)
604 		goto out;
605 
606 	if ((sk = x25_alloc_socket(sock_net(osk), 0)) == NULL)
607 		goto out;
608 
609 	x25 = x25_sk(sk);
610 
611 	sk->sk_type        = osk->sk_type;
612 	sk->sk_priority    = osk->sk_priority;
613 	sk->sk_protocol    = osk->sk_protocol;
614 	sk->sk_rcvbuf      = osk->sk_rcvbuf;
615 	sk->sk_sndbuf      = osk->sk_sndbuf;
616 	sk->sk_state       = TCP_ESTABLISHED;
617 	sk->sk_backlog_rcv = osk->sk_backlog_rcv;
618 	sock_copy_flags(sk, osk);
619 
620 	ox25 = x25_sk(osk);
621 	x25->t21        = ox25->t21;
622 	x25->t22        = ox25->t22;
623 	x25->t23        = ox25->t23;
624 	x25->t2         = ox25->t2;
625 	x25->flags	= ox25->flags;
626 	x25->facilities = ox25->facilities;
627 	x25->dte_facilities = ox25->dte_facilities;
628 	x25->cudmatchlength = ox25->cudmatchlength;
629 
630 	clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
631 	x25_init_timers(sk);
632 out:
633 	return sk;
634 }
635 
636 static int x25_release(struct socket *sock)
637 {
638 	struct sock *sk = sock->sk;
639 	struct x25_sock *x25;
640 
641 	if (!sk)
642 		return 0;
643 
644 	x25 = x25_sk(sk);
645 
646 	sock_hold(sk);
647 	lock_sock(sk);
648 	switch (x25->state) {
649 
650 		case X25_STATE_0:
651 		case X25_STATE_2:
652 			x25_disconnect(sk, 0, 0, 0);
653 			__x25_destroy_socket(sk);
654 			goto out;
655 
656 		case X25_STATE_1:
657 		case X25_STATE_3:
658 		case X25_STATE_4:
659 			x25_clear_queues(sk);
660 			x25_write_internal(sk, X25_CLEAR_REQUEST);
661 			x25_start_t23timer(sk);
662 			x25->state = X25_STATE_2;
663 			sk->sk_state	= TCP_CLOSE;
664 			sk->sk_shutdown	|= SEND_SHUTDOWN;
665 			sk->sk_state_change(sk);
666 			sock_set_flag(sk, SOCK_DEAD);
667 			sock_set_flag(sk, SOCK_DESTROY);
668 			break;
669 	}
670 
671 	sock_orphan(sk);
672 out:
673 	release_sock(sk);
674 	sock_put(sk);
675 	return 0;
676 }
677 
678 static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
679 {
680 	struct sock *sk = sock->sk;
681 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
682 	int len, i, rc = 0;
683 
684 	if (!sock_flag(sk, SOCK_ZAPPED) ||
685 	    addr_len != sizeof(struct sockaddr_x25) ||
686 	    addr->sx25_family != AF_X25) {
687 		rc = -EINVAL;
688 		goto out;
689 	}
690 
691 	/* check for the null_x25_address */
692 	if (strcmp(addr->sx25_addr.x25_addr, null_x25_address.x25_addr)) {
693 
694 		len = strlen(addr->sx25_addr.x25_addr);
695 		for (i = 0; i < len; i++) {
696 			if (!isdigit(addr->sx25_addr.x25_addr[i])) {
697 				rc = -EINVAL;
698 				goto out;
699 			}
700 		}
701 	}
702 
703 	lock_sock(sk);
704 	x25_sk(sk)->source_addr = addr->sx25_addr;
705 	x25_insert_socket(sk);
706 	sock_reset_flag(sk, SOCK_ZAPPED);
707 	release_sock(sk);
708 	SOCK_DEBUG(sk, "x25_bind: socket is bound\n");
709 out:
710 	return rc;
711 }
712 
713 static int x25_wait_for_connection_establishment(struct sock *sk)
714 {
715 	DECLARE_WAITQUEUE(wait, current);
716 	int rc;
717 
718 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
719 	for (;;) {
720 		__set_current_state(TASK_INTERRUPTIBLE);
721 		rc = -ERESTARTSYS;
722 		if (signal_pending(current))
723 			break;
724 		rc = sock_error(sk);
725 		if (rc) {
726 			sk->sk_socket->state = SS_UNCONNECTED;
727 			break;
728 		}
729 		rc = 0;
730 		if (sk->sk_state != TCP_ESTABLISHED) {
731 			release_sock(sk);
732 			schedule();
733 			lock_sock(sk);
734 		} else
735 			break;
736 	}
737 	__set_current_state(TASK_RUNNING);
738 	remove_wait_queue(sk_sleep(sk), &wait);
739 	return rc;
740 }
741 
742 static int x25_connect(struct socket *sock, struct sockaddr *uaddr,
743 		       int addr_len, int flags)
744 {
745 	struct sock *sk = sock->sk;
746 	struct x25_sock *x25 = x25_sk(sk);
747 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
748 	struct x25_route *rt;
749 	int rc = 0;
750 
751 	lock_sock(sk);
752 	if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
753 		sock->state = SS_CONNECTED;
754 		goto out; /* Connect completed during a ERESTARTSYS event */
755 	}
756 
757 	rc = -ECONNREFUSED;
758 	if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
759 		sock->state = SS_UNCONNECTED;
760 		goto out;
761 	}
762 
763 	rc = -EISCONN;	/* No reconnect on a seqpacket socket */
764 	if (sk->sk_state == TCP_ESTABLISHED)
765 		goto out;
766 
767 	sk->sk_state   = TCP_CLOSE;
768 	sock->state = SS_UNCONNECTED;
769 
770 	rc = -EINVAL;
771 	if (addr_len != sizeof(struct sockaddr_x25) ||
772 	    addr->sx25_family != AF_X25)
773 		goto out;
774 
775 	rc = -ENETUNREACH;
776 	rt = x25_get_route(&addr->sx25_addr);
777 	if (!rt)
778 		goto out;
779 
780 	x25->neighbour = x25_get_neigh(rt->dev);
781 	if (!x25->neighbour)
782 		goto out_put_route;
783 
784 	x25_limit_facilities(&x25->facilities, x25->neighbour);
785 
786 	x25->lci = x25_new_lci(x25->neighbour);
787 	if (!x25->lci)
788 		goto out_put_neigh;
789 
790 	rc = -EINVAL;
791 	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
792 		goto out_put_neigh;
793 
794 	if (!strcmp(x25->source_addr.x25_addr, null_x25_address.x25_addr))
795 		memset(&x25->source_addr, '\0', X25_ADDR_LEN);
796 
797 	x25->dest_addr = addr->sx25_addr;
798 
799 	/* Move to connecting socket, start sending Connect Requests */
800 	sock->state   = SS_CONNECTING;
801 	sk->sk_state  = TCP_SYN_SENT;
802 
803 	x25->state = X25_STATE_1;
804 
805 	x25_write_internal(sk, X25_CALL_REQUEST);
806 
807 	x25_start_heartbeat(sk);
808 	x25_start_t21timer(sk);
809 
810 	/* Now the loop */
811 	rc = -EINPROGRESS;
812 	if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK))
813 		goto out_put_neigh;
814 
815 	rc = x25_wait_for_connection_establishment(sk);
816 	if (rc)
817 		goto out_put_neigh;
818 
819 	sock->state = SS_CONNECTED;
820 	rc = 0;
821 out_put_neigh:
822 	if (rc)
823 		x25_neigh_put(x25->neighbour);
824 out_put_route:
825 	x25_route_put(rt);
826 out:
827 	release_sock(sk);
828 	return rc;
829 }
830 
831 static int x25_wait_for_data(struct sock *sk, long timeout)
832 {
833 	DECLARE_WAITQUEUE(wait, current);
834 	int rc = 0;
835 
836 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
837 	for (;;) {
838 		__set_current_state(TASK_INTERRUPTIBLE);
839 		if (sk->sk_shutdown & RCV_SHUTDOWN)
840 			break;
841 		rc = -ERESTARTSYS;
842 		if (signal_pending(current))
843 			break;
844 		rc = -EAGAIN;
845 		if (!timeout)
846 			break;
847 		rc = 0;
848 		if (skb_queue_empty(&sk->sk_receive_queue)) {
849 			release_sock(sk);
850 			timeout = schedule_timeout(timeout);
851 			lock_sock(sk);
852 		} else
853 			break;
854 	}
855 	__set_current_state(TASK_RUNNING);
856 	remove_wait_queue(sk_sleep(sk), &wait);
857 	return rc;
858 }
859 
860 static int x25_accept(struct socket *sock, struct socket *newsock, int flags,
861 		      bool kern)
862 {
863 	struct sock *sk = sock->sk;
864 	struct sock *newsk;
865 	struct sk_buff *skb;
866 	int rc = -EINVAL;
867 
868 	if (!sk)
869 		goto out;
870 
871 	rc = -EOPNOTSUPP;
872 	if (sk->sk_type != SOCK_SEQPACKET)
873 		goto out;
874 
875 	lock_sock(sk);
876 	rc = -EINVAL;
877 	if (sk->sk_state != TCP_LISTEN)
878 		goto out2;
879 
880 	rc = x25_wait_for_data(sk, sk->sk_rcvtimeo);
881 	if (rc)
882 		goto out2;
883 	skb = skb_dequeue(&sk->sk_receive_queue);
884 	rc = -EINVAL;
885 	if (!skb->sk)
886 		goto out2;
887 	newsk		 = skb->sk;
888 	sock_graft(newsk, newsock);
889 
890 	/* Now attach up the new socket */
891 	skb->sk = NULL;
892 	kfree_skb(skb);
893 	sk->sk_ack_backlog--;
894 	newsock->state = SS_CONNECTED;
895 	rc = 0;
896 out2:
897 	release_sock(sk);
898 out:
899 	return rc;
900 }
901 
902 static int x25_getname(struct socket *sock, struct sockaddr *uaddr,
903 		       int peer)
904 {
905 	struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)uaddr;
906 	struct sock *sk = sock->sk;
907 	struct x25_sock *x25 = x25_sk(sk);
908 	int rc = 0;
909 
910 	if (peer) {
911 		if (sk->sk_state != TCP_ESTABLISHED) {
912 			rc = -ENOTCONN;
913 			goto out;
914 		}
915 		sx25->sx25_addr = x25->dest_addr;
916 	} else
917 		sx25->sx25_addr = x25->source_addr;
918 
919 	sx25->sx25_family = AF_X25;
920 	rc = sizeof(*sx25);
921 
922 out:
923 	return rc;
924 }
925 
926 int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
927 			unsigned int lci)
928 {
929 	struct sock *sk;
930 	struct sock *make;
931 	struct x25_sock *makex25;
932 	struct x25_address source_addr, dest_addr;
933 	struct x25_facilities facilities;
934 	struct x25_dte_facilities dte_facilities;
935 	int len, addr_len, rc;
936 
937 	/*
938 	 *	Remove the LCI and frame type.
939 	 */
940 	skb_pull(skb, X25_STD_MIN_LEN);
941 
942 	/*
943 	 *	Extract the X.25 addresses and convert them to ASCII strings,
944 	 *	and remove them.
945 	 *
946 	 *	Address block is mandatory in call request packets
947 	 */
948 	addr_len = x25_parse_address_block(skb, &source_addr, &dest_addr);
949 	if (addr_len <= 0)
950 		goto out_clear_request;
951 	skb_pull(skb, addr_len);
952 
953 	/*
954 	 *	Get the length of the facilities, skip past them for the moment
955 	 *	get the call user data because this is needed to determine
956 	 *	the correct listener
957 	 *
958 	 *	Facilities length is mandatory in call request packets
959 	 */
960 	if (!pskb_may_pull(skb, 1))
961 		goto out_clear_request;
962 	len = skb->data[0] + 1;
963 	if (!pskb_may_pull(skb, len))
964 		goto out_clear_request;
965 	skb_pull(skb,len);
966 
967 	/*
968 	 *	Ensure that the amount of call user data is valid.
969 	 */
970 	if (skb->len > X25_MAX_CUD_LEN)
971 		goto out_clear_request;
972 
973 	/*
974 	 *	Get all the call user data so it can be used in
975 	 *	x25_find_listener and skb_copy_from_linear_data up ahead.
976 	 */
977 	if (!pskb_may_pull(skb, skb->len))
978 		goto out_clear_request;
979 
980 	/*
981 	 *	Find a listener for the particular address/cud pair.
982 	 */
983 	sk = x25_find_listener(&source_addr,skb);
984 	skb_push(skb,len);
985 
986 	if (sk != NULL && sk_acceptq_is_full(sk)) {
987 		goto out_sock_put;
988 	}
989 
990 	/*
991 	 *	We dont have any listeners for this incoming call.
992 	 *	Try forwarding it.
993 	 */
994 	if (sk == NULL) {
995 		skb_push(skb, addr_len + X25_STD_MIN_LEN);
996 		if (sysctl_x25_forward &&
997 				x25_forward_call(&dest_addr, nb, skb, lci) > 0)
998 		{
999 			/* Call was forwarded, dont process it any more */
1000 			kfree_skb(skb);
1001 			rc = 1;
1002 			goto out;
1003 		} else {
1004 			/* No listeners, can't forward, clear the call */
1005 			goto out_clear_request;
1006 		}
1007 	}
1008 
1009 	/*
1010 	 *	Try to reach a compromise on the requested facilities.
1011 	 */
1012 	len = x25_negotiate_facilities(skb, sk, &facilities, &dte_facilities);
1013 	if (len == -1)
1014 		goto out_sock_put;
1015 
1016 	/*
1017 	 * current neighbour/link might impose additional limits
1018 	 * on certain facilties
1019 	 */
1020 
1021 	x25_limit_facilities(&facilities, nb);
1022 
1023 	/*
1024 	 *	Try to create a new socket.
1025 	 */
1026 	make = x25_make_new(sk);
1027 	if (!make)
1028 		goto out_sock_put;
1029 
1030 	/*
1031 	 *	Remove the facilities
1032 	 */
1033 	skb_pull(skb, len);
1034 
1035 	skb->sk     = make;
1036 	make->sk_state = TCP_ESTABLISHED;
1037 
1038 	makex25 = x25_sk(make);
1039 	makex25->lci           = lci;
1040 	makex25->dest_addr     = dest_addr;
1041 	makex25->source_addr   = source_addr;
1042 	makex25->neighbour     = nb;
1043 	makex25->facilities    = facilities;
1044 	makex25->dte_facilities= dte_facilities;
1045 	makex25->vc_facil_mask = x25_sk(sk)->vc_facil_mask;
1046 	/* ensure no reverse facil on accept */
1047 	makex25->vc_facil_mask &= ~X25_MASK_REVERSE;
1048 	/* ensure no calling address extension on accept */
1049 	makex25->vc_facil_mask &= ~X25_MASK_CALLING_AE;
1050 	makex25->cudmatchlength = x25_sk(sk)->cudmatchlength;
1051 
1052 	/* Normally all calls are accepted immediately */
1053 	if (test_bit(X25_ACCPT_APPRV_FLAG, &makex25->flags)) {
1054 		x25_write_internal(make, X25_CALL_ACCEPTED);
1055 		makex25->state = X25_STATE_3;
1056 	}
1057 
1058 	/*
1059 	 *	Incoming Call User Data.
1060 	 */
1061 	skb_copy_from_linear_data(skb, makex25->calluserdata.cuddata, skb->len);
1062 	makex25->calluserdata.cudlength = skb->len;
1063 
1064 	sk->sk_ack_backlog++;
1065 
1066 	x25_insert_socket(make);
1067 
1068 	skb_queue_head(&sk->sk_receive_queue, skb);
1069 
1070 	x25_start_heartbeat(make);
1071 
1072 	if (!sock_flag(sk, SOCK_DEAD))
1073 		sk->sk_data_ready(sk);
1074 	rc = 1;
1075 	sock_put(sk);
1076 out:
1077 	return rc;
1078 out_sock_put:
1079 	sock_put(sk);
1080 out_clear_request:
1081 	rc = 0;
1082 	x25_transmit_clear_request(nb, lci, 0x01);
1083 	goto out;
1084 }
1085 
1086 static int x25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1087 {
1088 	struct sock *sk = sock->sk;
1089 	struct x25_sock *x25 = x25_sk(sk);
1090 	DECLARE_SOCKADDR(struct sockaddr_x25 *, usx25, msg->msg_name);
1091 	struct sockaddr_x25 sx25;
1092 	struct sk_buff *skb;
1093 	unsigned char *asmptr;
1094 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1095 	size_t size;
1096 	int qbit = 0, rc = -EINVAL;
1097 
1098 	lock_sock(sk);
1099 	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_OOB|MSG_EOR|MSG_CMSG_COMPAT))
1100 		goto out;
1101 
1102 	/* we currently don't support segmented records at the user interface */
1103 	if (!(msg->msg_flags & (MSG_EOR|MSG_OOB)))
1104 		goto out;
1105 
1106 	rc = -EADDRNOTAVAIL;
1107 	if (sock_flag(sk, SOCK_ZAPPED))
1108 		goto out;
1109 
1110 	rc = -EPIPE;
1111 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1112 		send_sig(SIGPIPE, current, 0);
1113 		goto out;
1114 	}
1115 
1116 	rc = -ENETUNREACH;
1117 	if (!x25->neighbour)
1118 		goto out;
1119 
1120 	if (usx25) {
1121 		rc = -EINVAL;
1122 		if (msg->msg_namelen < sizeof(sx25))
1123 			goto out;
1124 		memcpy(&sx25, usx25, sizeof(sx25));
1125 		rc = -EISCONN;
1126 		if (strcmp(x25->dest_addr.x25_addr, sx25.sx25_addr.x25_addr))
1127 			goto out;
1128 		rc = -EINVAL;
1129 		if (sx25.sx25_family != AF_X25)
1130 			goto out;
1131 	} else {
1132 		/*
1133 		 *	FIXME 1003.1g - if the socket is like this because
1134 		 *	it has become closed (not started closed) we ought
1135 		 *	to SIGPIPE, EPIPE;
1136 		 */
1137 		rc = -ENOTCONN;
1138 		if (sk->sk_state != TCP_ESTABLISHED)
1139 			goto out;
1140 
1141 		sx25.sx25_family = AF_X25;
1142 		sx25.sx25_addr   = x25->dest_addr;
1143 	}
1144 
1145 	/* Sanity check the packet size */
1146 	if (len > 65535) {
1147 		rc = -EMSGSIZE;
1148 		goto out;
1149 	}
1150 
1151 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: Addresses built.\n");
1152 
1153 	/* Build a packet */
1154 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: building packet.\n");
1155 
1156 	if ((msg->msg_flags & MSG_OOB) && len > 32)
1157 		len = 32;
1158 
1159 	size = len + X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
1160 
1161 	release_sock(sk);
1162 	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
1163 	lock_sock(sk);
1164 	if (!skb)
1165 		goto out;
1166 	X25_SKB_CB(skb)->flags = msg->msg_flags;
1167 
1168 	skb_reserve(skb, X25_MAX_L2_LEN + X25_EXT_MIN_LEN);
1169 
1170 	/*
1171 	 *	Put the data on the end
1172 	 */
1173 	SOCK_DEBUG(sk, "x25_sendmsg: Copying user data\n");
1174 
1175 	skb_reset_transport_header(skb);
1176 	skb_put(skb, len);
1177 
1178 	rc = memcpy_from_msg(skb_transport_header(skb), msg, len);
1179 	if (rc)
1180 		goto out_kfree_skb;
1181 
1182 	/*
1183 	 *	If the Q BIT Include socket option is in force, the first
1184 	 *	byte of the user data is the logical value of the Q Bit.
1185 	 */
1186 	if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1187 		if (!pskb_may_pull(skb, 1))
1188 			goto out_kfree_skb;
1189 
1190 		qbit = skb->data[0];
1191 		skb_pull(skb, 1);
1192 	}
1193 
1194 	/*
1195 	 *	Push down the X.25 header
1196 	 */
1197 	SOCK_DEBUG(sk, "x25_sendmsg: Building X.25 Header.\n");
1198 
1199 	if (msg->msg_flags & MSG_OOB) {
1200 		if (x25->neighbour->extended) {
1201 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1202 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1203 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1204 			*asmptr++ = X25_INTERRUPT;
1205 		} else {
1206 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1207 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1208 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1209 			*asmptr++ = X25_INTERRUPT;
1210 		}
1211 	} else {
1212 		if (x25->neighbour->extended) {
1213 			/* Build an Extended X.25 header */
1214 			asmptr    = skb_push(skb, X25_EXT_MIN_LEN);
1215 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1216 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1217 			*asmptr++ = X25_DATA;
1218 			*asmptr++ = X25_DATA;
1219 		} else {
1220 			/* Build an Standard X.25 header */
1221 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1222 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1223 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1224 			*asmptr++ = X25_DATA;
1225 		}
1226 
1227 		if (qbit)
1228 			skb->data[0] |= X25_Q_BIT;
1229 	}
1230 
1231 	SOCK_DEBUG(sk, "x25_sendmsg: Built header.\n");
1232 	SOCK_DEBUG(sk, "x25_sendmsg: Transmitting buffer\n");
1233 
1234 	rc = -ENOTCONN;
1235 	if (sk->sk_state != TCP_ESTABLISHED)
1236 		goto out_kfree_skb;
1237 
1238 	if (msg->msg_flags & MSG_OOB)
1239 		skb_queue_tail(&x25->interrupt_out_queue, skb);
1240 	else {
1241 		rc = x25_output(sk, skb);
1242 		len = rc;
1243 		if (rc < 0)
1244 			kfree_skb(skb);
1245 		else if (test_bit(X25_Q_BIT_FLAG, &x25->flags))
1246 			len++;
1247 	}
1248 
1249 	x25_kick(sk);
1250 	rc = len;
1251 out:
1252 	release_sock(sk);
1253 	return rc;
1254 out_kfree_skb:
1255 	kfree_skb(skb);
1256 	goto out;
1257 }
1258 
1259 
1260 static int x25_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1261 		       int flags)
1262 {
1263 	struct sock *sk = sock->sk;
1264 	struct x25_sock *x25 = x25_sk(sk);
1265 	DECLARE_SOCKADDR(struct sockaddr_x25 *, sx25, msg->msg_name);
1266 	size_t copied;
1267 	int qbit, header_len;
1268 	struct sk_buff *skb;
1269 	unsigned char *asmptr;
1270 	int rc = -ENOTCONN;
1271 
1272 	lock_sock(sk);
1273 
1274 	if (x25->neighbour == NULL)
1275 		goto out;
1276 
1277 	header_len = x25->neighbour->extended ?
1278 		X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
1279 
1280 	/*
1281 	 * This works for seqpacket too. The receiver has ordered the queue for
1282 	 * us! We do one quick check first though
1283 	 */
1284 	if (sk->sk_state != TCP_ESTABLISHED)
1285 		goto out;
1286 
1287 	if (flags & MSG_OOB) {
1288 		rc = -EINVAL;
1289 		if (sock_flag(sk, SOCK_URGINLINE) ||
1290 		    !skb_peek(&x25->interrupt_in_queue))
1291 			goto out;
1292 
1293 		skb = skb_dequeue(&x25->interrupt_in_queue);
1294 
1295 		if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
1296 			goto out_free_dgram;
1297 
1298 		skb_pull(skb, X25_STD_MIN_LEN);
1299 
1300 		/*
1301 		 *	No Q bit information on Interrupt data.
1302 		 */
1303 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1304 			asmptr  = skb_push(skb, 1);
1305 			*asmptr = 0x00;
1306 		}
1307 
1308 		msg->msg_flags |= MSG_OOB;
1309 	} else {
1310 		/* Now we can treat all alike */
1311 		release_sock(sk);
1312 		skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1313 					flags & MSG_DONTWAIT, &rc);
1314 		lock_sock(sk);
1315 		if (!skb)
1316 			goto out;
1317 
1318 		if (!pskb_may_pull(skb, header_len))
1319 			goto out_free_dgram;
1320 
1321 		qbit = (skb->data[0] & X25_Q_BIT) == X25_Q_BIT;
1322 
1323 		skb_pull(skb, header_len);
1324 
1325 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1326 			asmptr  = skb_push(skb, 1);
1327 			*asmptr = qbit;
1328 		}
1329 	}
1330 
1331 	skb_reset_transport_header(skb);
1332 	copied = skb->len;
1333 
1334 	if (copied > size) {
1335 		copied = size;
1336 		msg->msg_flags |= MSG_TRUNC;
1337 	}
1338 
1339 	/* Currently, each datagram always contains a complete record */
1340 	msg->msg_flags |= MSG_EOR;
1341 
1342 	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
1343 	if (rc)
1344 		goto out_free_dgram;
1345 
1346 	if (sx25) {
1347 		sx25->sx25_family = AF_X25;
1348 		sx25->sx25_addr   = x25->dest_addr;
1349 		msg->msg_namelen = sizeof(*sx25);
1350 	}
1351 
1352 	x25_check_rbuf(sk);
1353 	rc = copied;
1354 out_free_dgram:
1355 	skb_free_datagram(sk, skb);
1356 out:
1357 	release_sock(sk);
1358 	return rc;
1359 }
1360 
1361 
1362 static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1363 {
1364 	struct sock *sk = sock->sk;
1365 	struct x25_sock *x25 = x25_sk(sk);
1366 	void __user *argp = (void __user *)arg;
1367 	int rc;
1368 
1369 	switch (cmd) {
1370 	case TIOCOUTQ: {
1371 		int amount;
1372 
1373 		amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1374 		if (amount < 0)
1375 			amount = 0;
1376 		rc = put_user(amount, (unsigned int __user *)argp);
1377 		break;
1378 	}
1379 
1380 	case TIOCINQ: {
1381 		struct sk_buff *skb;
1382 		int amount = 0;
1383 		/*
1384 		 * These two are safe on a single CPU system as
1385 		 * only user tasks fiddle here
1386 		 */
1387 		lock_sock(sk);
1388 		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1389 			amount = skb->len;
1390 		release_sock(sk);
1391 		rc = put_user(amount, (unsigned int __user *)argp);
1392 		break;
1393 	}
1394 
1395 	case SIOCGSTAMP:
1396 		rc = -EINVAL;
1397 		if (sk)
1398 			rc = sock_get_timestamp(sk,
1399 						(struct timeval __user *)argp);
1400 		break;
1401 	case SIOCGSTAMPNS:
1402 		rc = -EINVAL;
1403 		if (sk)
1404 			rc = sock_get_timestampns(sk,
1405 					(struct timespec __user *)argp);
1406 		break;
1407 	case SIOCGIFADDR:
1408 	case SIOCSIFADDR:
1409 	case SIOCGIFDSTADDR:
1410 	case SIOCSIFDSTADDR:
1411 	case SIOCGIFBRDADDR:
1412 	case SIOCSIFBRDADDR:
1413 	case SIOCGIFNETMASK:
1414 	case SIOCSIFNETMASK:
1415 	case SIOCGIFMETRIC:
1416 	case SIOCSIFMETRIC:
1417 		rc = -EINVAL;
1418 		break;
1419 	case SIOCADDRT:
1420 	case SIOCDELRT:
1421 		rc = -EPERM;
1422 		if (!capable(CAP_NET_ADMIN))
1423 			break;
1424 		rc = x25_route_ioctl(cmd, argp);
1425 		break;
1426 	case SIOCX25GSUBSCRIP:
1427 		rc = x25_subscr_ioctl(cmd, argp);
1428 		break;
1429 	case SIOCX25SSUBSCRIP:
1430 		rc = -EPERM;
1431 		if (!capable(CAP_NET_ADMIN))
1432 			break;
1433 		rc = x25_subscr_ioctl(cmd, argp);
1434 		break;
1435 	case SIOCX25GFACILITIES: {
1436 		lock_sock(sk);
1437 		rc = copy_to_user(argp, &x25->facilities,
1438 				  sizeof(x25->facilities))
1439 			? -EFAULT : 0;
1440 		release_sock(sk);
1441 		break;
1442 	}
1443 
1444 	case SIOCX25SFACILITIES: {
1445 		struct x25_facilities facilities;
1446 		rc = -EFAULT;
1447 		if (copy_from_user(&facilities, argp, sizeof(facilities)))
1448 			break;
1449 		rc = -EINVAL;
1450 		lock_sock(sk);
1451 		if (sk->sk_state != TCP_LISTEN &&
1452 		    sk->sk_state != TCP_CLOSE)
1453 			goto out_fac_release;
1454 		if (facilities.pacsize_in < X25_PS16 ||
1455 		    facilities.pacsize_in > X25_PS4096)
1456 			goto out_fac_release;
1457 		if (facilities.pacsize_out < X25_PS16 ||
1458 		    facilities.pacsize_out > X25_PS4096)
1459 			goto out_fac_release;
1460 		if (facilities.winsize_in < 1 ||
1461 		    facilities.winsize_in > 127)
1462 			goto out_fac_release;
1463 		if (facilities.throughput) {
1464 			int out = facilities.throughput & 0xf0;
1465 			int in  = facilities.throughput & 0x0f;
1466 			if (!out)
1467 				facilities.throughput |=
1468 					X25_DEFAULT_THROUGHPUT << 4;
1469 			else if (out < 0x30 || out > 0xD0)
1470 				goto out_fac_release;
1471 			if (!in)
1472 				facilities.throughput |=
1473 					X25_DEFAULT_THROUGHPUT;
1474 			else if (in < 0x03 || in > 0x0D)
1475 				goto out_fac_release;
1476 		}
1477 		if (facilities.reverse &&
1478 		    (facilities.reverse & 0x81) != 0x81)
1479 			goto out_fac_release;
1480 		x25->facilities = facilities;
1481 		rc = 0;
1482 out_fac_release:
1483 		release_sock(sk);
1484 		break;
1485 	}
1486 
1487 	case SIOCX25GDTEFACILITIES: {
1488 		lock_sock(sk);
1489 		rc = copy_to_user(argp, &x25->dte_facilities,
1490 				  sizeof(x25->dte_facilities));
1491 		release_sock(sk);
1492 		if (rc)
1493 			rc = -EFAULT;
1494 		break;
1495 	}
1496 
1497 	case SIOCX25SDTEFACILITIES: {
1498 		struct x25_dte_facilities dtefacs;
1499 		rc = -EFAULT;
1500 		if (copy_from_user(&dtefacs, argp, sizeof(dtefacs)))
1501 			break;
1502 		rc = -EINVAL;
1503 		lock_sock(sk);
1504 		if (sk->sk_state != TCP_LISTEN &&
1505 		    sk->sk_state != TCP_CLOSE)
1506 			goto out_dtefac_release;
1507 		if (dtefacs.calling_len > X25_MAX_AE_LEN)
1508 			goto out_dtefac_release;
1509 		if (dtefacs.called_len > X25_MAX_AE_LEN)
1510 			goto out_dtefac_release;
1511 		x25->dte_facilities = dtefacs;
1512 		rc = 0;
1513 out_dtefac_release:
1514 		release_sock(sk);
1515 		break;
1516 	}
1517 
1518 	case SIOCX25GCALLUSERDATA: {
1519 		lock_sock(sk);
1520 		rc = copy_to_user(argp, &x25->calluserdata,
1521 				  sizeof(x25->calluserdata))
1522 			? -EFAULT : 0;
1523 		release_sock(sk);
1524 		break;
1525 	}
1526 
1527 	case SIOCX25SCALLUSERDATA: {
1528 		struct x25_calluserdata calluserdata;
1529 
1530 		rc = -EFAULT;
1531 		if (copy_from_user(&calluserdata, argp, sizeof(calluserdata)))
1532 			break;
1533 		rc = -EINVAL;
1534 		if (calluserdata.cudlength > X25_MAX_CUD_LEN)
1535 			break;
1536 		lock_sock(sk);
1537 		x25->calluserdata = calluserdata;
1538 		release_sock(sk);
1539 		rc = 0;
1540 		break;
1541 	}
1542 
1543 	case SIOCX25GCAUSEDIAG: {
1544 		lock_sock(sk);
1545 		rc = copy_to_user(argp, &x25->causediag, sizeof(x25->causediag))
1546 			? -EFAULT : 0;
1547 		release_sock(sk);
1548 		break;
1549 	}
1550 
1551 	case SIOCX25SCAUSEDIAG: {
1552 		struct x25_causediag causediag;
1553 		rc = -EFAULT;
1554 		if (copy_from_user(&causediag, argp, sizeof(causediag)))
1555 			break;
1556 		lock_sock(sk);
1557 		x25->causediag = causediag;
1558 		release_sock(sk);
1559 		rc = 0;
1560 		break;
1561 
1562 	}
1563 
1564 	case SIOCX25SCUDMATCHLEN: {
1565 		struct x25_subaddr sub_addr;
1566 		rc = -EINVAL;
1567 		lock_sock(sk);
1568 		if(sk->sk_state != TCP_CLOSE)
1569 			goto out_cud_release;
1570 		rc = -EFAULT;
1571 		if (copy_from_user(&sub_addr, argp,
1572 				   sizeof(sub_addr)))
1573 			goto out_cud_release;
1574 		rc = -EINVAL;
1575 		if (sub_addr.cudmatchlength > X25_MAX_CUD_LEN)
1576 			goto out_cud_release;
1577 		x25->cudmatchlength = sub_addr.cudmatchlength;
1578 		rc = 0;
1579 out_cud_release:
1580 		release_sock(sk);
1581 		break;
1582 	}
1583 
1584 	case SIOCX25CALLACCPTAPPRV: {
1585 		rc = -EINVAL;
1586 		lock_sock(sk);
1587 		if (sk->sk_state == TCP_CLOSE) {
1588 			clear_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);
1589 			rc = 0;
1590 		}
1591 		release_sock(sk);
1592 		break;
1593 	}
1594 
1595 	case SIOCX25SENDCALLACCPT:  {
1596 		rc = -EINVAL;
1597 		lock_sock(sk);
1598 		if (sk->sk_state != TCP_ESTABLISHED)
1599 			goto out_sendcallaccpt_release;
1600 		/* must call accptapprv above */
1601 		if (test_bit(X25_ACCPT_APPRV_FLAG, &x25->flags))
1602 			goto out_sendcallaccpt_release;
1603 		x25_write_internal(sk, X25_CALL_ACCEPTED);
1604 		x25->state = X25_STATE_3;
1605 		rc = 0;
1606 out_sendcallaccpt_release:
1607 		release_sock(sk);
1608 		break;
1609 	}
1610 
1611 	default:
1612 		rc = -ENOIOCTLCMD;
1613 		break;
1614 	}
1615 
1616 	return rc;
1617 }
1618 
1619 static const struct net_proto_family x25_family_ops = {
1620 	.family =	AF_X25,
1621 	.create =	x25_create,
1622 	.owner	=	THIS_MODULE,
1623 };
1624 
1625 #ifdef CONFIG_COMPAT
1626 static int compat_x25_subscr_ioctl(unsigned int cmd,
1627 		struct compat_x25_subscrip_struct __user *x25_subscr32)
1628 {
1629 	struct compat_x25_subscrip_struct x25_subscr;
1630 	struct x25_neigh *nb;
1631 	struct net_device *dev;
1632 	int rc = -EINVAL;
1633 
1634 	rc = -EFAULT;
1635 	if (copy_from_user(&x25_subscr, x25_subscr32, sizeof(*x25_subscr32)))
1636 		goto out;
1637 
1638 	rc = -EINVAL;
1639 	dev = x25_dev_get(x25_subscr.device);
1640 	if (dev == NULL)
1641 		goto out;
1642 
1643 	nb = x25_get_neigh(dev);
1644 	if (nb == NULL)
1645 		goto out_dev_put;
1646 
1647 	dev_put(dev);
1648 
1649 	if (cmd == SIOCX25GSUBSCRIP) {
1650 		read_lock_bh(&x25_neigh_list_lock);
1651 		x25_subscr.extended = nb->extended;
1652 		x25_subscr.global_facil_mask = nb->global_facil_mask;
1653 		read_unlock_bh(&x25_neigh_list_lock);
1654 		rc = copy_to_user(x25_subscr32, &x25_subscr,
1655 				sizeof(*x25_subscr32)) ? -EFAULT : 0;
1656 	} else {
1657 		rc = -EINVAL;
1658 		if (x25_subscr.extended == 0 || x25_subscr.extended == 1) {
1659 			rc = 0;
1660 			write_lock_bh(&x25_neigh_list_lock);
1661 			nb->extended = x25_subscr.extended;
1662 			nb->global_facil_mask = x25_subscr.global_facil_mask;
1663 			write_unlock_bh(&x25_neigh_list_lock);
1664 		}
1665 	}
1666 	x25_neigh_put(nb);
1667 out:
1668 	return rc;
1669 out_dev_put:
1670 	dev_put(dev);
1671 	goto out;
1672 }
1673 
1674 static int compat_x25_ioctl(struct socket *sock, unsigned int cmd,
1675 				unsigned long arg)
1676 {
1677 	void __user *argp = compat_ptr(arg);
1678 	struct sock *sk = sock->sk;
1679 
1680 	int rc = -ENOIOCTLCMD;
1681 
1682 	switch(cmd) {
1683 	case TIOCOUTQ:
1684 	case TIOCINQ:
1685 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1686 		break;
1687 	case SIOCGSTAMP:
1688 		rc = -EINVAL;
1689 		if (sk)
1690 			rc = compat_sock_get_timestamp(sk,
1691 					(struct timeval __user*)argp);
1692 		break;
1693 	case SIOCGSTAMPNS:
1694 		rc = -EINVAL;
1695 		if (sk)
1696 			rc = compat_sock_get_timestampns(sk,
1697 					(struct timespec __user*)argp);
1698 		break;
1699 	case SIOCGIFADDR:
1700 	case SIOCSIFADDR:
1701 	case SIOCGIFDSTADDR:
1702 	case SIOCSIFDSTADDR:
1703 	case SIOCGIFBRDADDR:
1704 	case SIOCSIFBRDADDR:
1705 	case SIOCGIFNETMASK:
1706 	case SIOCSIFNETMASK:
1707 	case SIOCGIFMETRIC:
1708 	case SIOCSIFMETRIC:
1709 		rc = -EINVAL;
1710 		break;
1711 	case SIOCADDRT:
1712 	case SIOCDELRT:
1713 		rc = -EPERM;
1714 		if (!capable(CAP_NET_ADMIN))
1715 			break;
1716 		rc = x25_route_ioctl(cmd, argp);
1717 		break;
1718 	case SIOCX25GSUBSCRIP:
1719 		rc = compat_x25_subscr_ioctl(cmd, argp);
1720 		break;
1721 	case SIOCX25SSUBSCRIP:
1722 		rc = -EPERM;
1723 		if (!capable(CAP_NET_ADMIN))
1724 			break;
1725 		rc = compat_x25_subscr_ioctl(cmd, argp);
1726 		break;
1727 	case SIOCX25GFACILITIES:
1728 	case SIOCX25SFACILITIES:
1729 	case SIOCX25GDTEFACILITIES:
1730 	case SIOCX25SDTEFACILITIES:
1731 	case SIOCX25GCALLUSERDATA:
1732 	case SIOCX25SCALLUSERDATA:
1733 	case SIOCX25GCAUSEDIAG:
1734 	case SIOCX25SCAUSEDIAG:
1735 	case SIOCX25SCUDMATCHLEN:
1736 	case SIOCX25CALLACCPTAPPRV:
1737 	case SIOCX25SENDCALLACCPT:
1738 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1739 		break;
1740 	default:
1741 		rc = -ENOIOCTLCMD;
1742 		break;
1743 	}
1744 	return rc;
1745 }
1746 #endif
1747 
1748 static const struct proto_ops x25_proto_ops = {
1749 	.family =	AF_X25,
1750 	.owner =	THIS_MODULE,
1751 	.release =	x25_release,
1752 	.bind =		x25_bind,
1753 	.connect =	x25_connect,
1754 	.socketpair =	sock_no_socketpair,
1755 	.accept =	x25_accept,
1756 	.getname =	x25_getname,
1757 	.poll =		datagram_poll,
1758 	.ioctl =	x25_ioctl,
1759 #ifdef CONFIG_COMPAT
1760 	.compat_ioctl = compat_x25_ioctl,
1761 #endif
1762 	.listen =	x25_listen,
1763 	.shutdown =	sock_no_shutdown,
1764 	.setsockopt =	x25_setsockopt,
1765 	.getsockopt =	x25_getsockopt,
1766 	.sendmsg =	x25_sendmsg,
1767 	.recvmsg =	x25_recvmsg,
1768 	.mmap =		sock_no_mmap,
1769 	.sendpage =	sock_no_sendpage,
1770 };
1771 
1772 static struct packet_type x25_packet_type __read_mostly = {
1773 	.type =	cpu_to_be16(ETH_P_X25),
1774 	.func =	x25_lapb_receive_frame,
1775 };
1776 
1777 static struct notifier_block x25_dev_notifier = {
1778 	.notifier_call = x25_device_event,
1779 };
1780 
1781 void x25_kill_by_neigh(struct x25_neigh *nb)
1782 {
1783 	struct sock *s;
1784 
1785 	write_lock_bh(&x25_list_lock);
1786 
1787 	sk_for_each(s, &x25_list)
1788 		if (x25_sk(s)->neighbour == nb)
1789 			x25_disconnect(s, ENETUNREACH, 0, 0);
1790 
1791 	write_unlock_bh(&x25_list_lock);
1792 
1793 	/* Remove any related forwards */
1794 	x25_clear_forward_by_dev(nb->dev);
1795 }
1796 
1797 static int __init x25_init(void)
1798 {
1799 	int rc;
1800 
1801 	rc = proto_register(&x25_proto, 0);
1802 	if (rc)
1803 		goto out;
1804 
1805 	rc = sock_register(&x25_family_ops);
1806 	if (rc)
1807 		goto out_proto;
1808 
1809 	dev_add_pack(&x25_packet_type);
1810 
1811 	rc = register_netdevice_notifier(&x25_dev_notifier);
1812 	if (rc)
1813 		goto out_sock;
1814 
1815 	rc = x25_register_sysctl();
1816 	if (rc)
1817 		goto out_dev;
1818 
1819 	rc = x25_proc_init();
1820 	if (rc)
1821 		goto out_sysctl;
1822 
1823 	pr_info("Linux Version 0.2\n");
1824 
1825 out:
1826 	return rc;
1827 out_sysctl:
1828 	x25_unregister_sysctl();
1829 out_dev:
1830 	unregister_netdevice_notifier(&x25_dev_notifier);
1831 out_sock:
1832 	dev_remove_pack(&x25_packet_type);
1833 	sock_unregister(AF_X25);
1834 out_proto:
1835 	proto_unregister(&x25_proto);
1836 	goto out;
1837 }
1838 module_init(x25_init);
1839 
1840 static void __exit x25_exit(void)
1841 {
1842 	x25_proc_exit();
1843 	x25_link_free();
1844 	x25_route_free();
1845 
1846 	x25_unregister_sysctl();
1847 
1848 	unregister_netdevice_notifier(&x25_dev_notifier);
1849 
1850 	dev_remove_pack(&x25_packet_type);
1851 
1852 	sock_unregister(AF_X25);
1853 	proto_unregister(&x25_proto);
1854 }
1855 module_exit(x25_exit);
1856 
1857 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
1858 MODULE_DESCRIPTION("The X.25 Packet Layer network layer protocol");
1859 MODULE_LICENSE("GPL");
1860 MODULE_ALIAS_NETPROTO(PF_X25);
1861