xref: /linux/net/x25/af_x25.c (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	X.25 Packet Layer release 002
4  *
5  *	This is ALPHA test software. This code may break your machine,
6  *	randomly fail to work with new releases, misbehave and/or generally
7  *	screw up. It might even work.
8  *
9  *	This code REQUIRES 2.1.15 or higher
10  *
11  *	History
12  *	X.25 001	Jonathan Naylor	Started coding.
13  *	X.25 002	Jonathan Naylor	Centralised disconnect handling.
14  *					New timer architecture.
15  *	2000-03-11	Henner Eisen	MSG_EOR handling more POSIX compliant.
16  *	2000-03-22	Daniela Squassoni Allowed disabling/enabling of
17  *					  facilities negotiation and increased
18  *					  the throughput upper limit.
19  *	2000-08-27	Arnaldo C. Melo s/suser/capable/ + micro cleanups
20  *	2000-09-04	Henner Eisen	Set sock->state in x25_accept().
21  *					Fixed x25_output() related skb leakage.
22  *	2000-10-02	Henner Eisen	Made x25_kick() single threaded per socket.
23  *	2000-10-27	Henner Eisen    MSG_DONTWAIT for fragment allocation.
24  *	2000-11-14	Henner Eisen    Closing datalink from NETDEV_GOING_DOWN
25  *	2002-10-06	Arnaldo C. Melo Get rid of cli/sti, move proc stuff to
26  *					x25_proc.c, using seq_file
27  *	2005-04-02	Shaun Pereira	Selective sub address matching
28  *					with call user data
29  *	2005-04-15	Shaun Pereira	Fast select with no restriction on
30  *					response
31  */
32 
33 #define pr_fmt(fmt) "X25: " fmt
34 
35 #include <linux/module.h>
36 #include <linux/capability.h>
37 #include <linux/errno.h>
38 #include <linux/kernel.h>
39 #include <linux/sched/signal.h>
40 #include <linux/timer.h>
41 #include <linux/string.h>
42 #include <linux/net.h>
43 #include <linux/netdevice.h>
44 #include <linux/if_arp.h>
45 #include <linux/skbuff.h>
46 #include <linux/slab.h>
47 #include <net/sock.h>
48 #include <net/tcp_states.h>
49 #include <linux/uaccess.h>
50 #include <linux/fcntl.h>
51 #include <linux/termios.h>	/* For TIOCINQ/OUTQ */
52 #include <linux/notifier.h>
53 #include <linux/init.h>
54 #include <linux/compat.h>
55 #include <linux/ctype.h>
56 
57 #include <net/x25.h>
58 #include <net/compat.h>
59 
60 int sysctl_x25_restart_request_timeout = X25_DEFAULT_T20;
61 int sysctl_x25_call_request_timeout    = X25_DEFAULT_T21;
62 int sysctl_x25_reset_request_timeout   = X25_DEFAULT_T22;
63 int sysctl_x25_clear_request_timeout   = X25_DEFAULT_T23;
64 int sysctl_x25_ack_holdback_timeout    = X25_DEFAULT_T2;
65 int sysctl_x25_forward                 = 0;
66 
67 HLIST_HEAD(x25_list);
68 DEFINE_RWLOCK(x25_list_lock);
69 
70 static const struct proto_ops x25_proto_ops;
71 
72 static const struct x25_address null_x25_address = {"               "};
73 
74 #ifdef CONFIG_COMPAT
75 struct compat_x25_subscrip_struct {
76 	char device[200-sizeof(compat_ulong_t)];
77 	compat_ulong_t global_facil_mask;
78 	compat_uint_t extended;
79 };
80 #endif
81 
82 
83 int x25_parse_address_block(struct sk_buff *skb,
84 		struct x25_address *called_addr,
85 		struct x25_address *calling_addr)
86 {
87 	unsigned char len;
88 	int needed;
89 	int rc;
90 
91 	if (!pskb_may_pull(skb, 1)) {
92 		/* packet has no address block */
93 		rc = 0;
94 		goto empty;
95 	}
96 
97 	len = *skb->data;
98 	needed = 1 + ((len >> 4) + (len & 0x0f) + 1) / 2;
99 
100 	if (!pskb_may_pull(skb, needed)) {
101 		/* packet is too short to hold the addresses it claims
102 		   to hold */
103 		rc = -1;
104 		goto empty;
105 	}
106 
107 	return x25_addr_ntoa(skb->data, called_addr, calling_addr);
108 
109 empty:
110 	*called_addr->x25_addr = 0;
111 	*calling_addr->x25_addr = 0;
112 
113 	return rc;
114 }
115 
116 
117 int x25_addr_ntoa(unsigned char *p, struct x25_address *called_addr,
118 		  struct x25_address *calling_addr)
119 {
120 	unsigned int called_len, calling_len;
121 	char *called, *calling;
122 	unsigned int i;
123 
124 	called_len  = (*p >> 0) & 0x0F;
125 	calling_len = (*p >> 4) & 0x0F;
126 
127 	called  = called_addr->x25_addr;
128 	calling = calling_addr->x25_addr;
129 	p++;
130 
131 	for (i = 0; i < (called_len + calling_len); i++) {
132 		if (i < called_len) {
133 			if (i % 2 != 0) {
134 				*called++ = ((*p >> 0) & 0x0F) + '0';
135 				p++;
136 			} else {
137 				*called++ = ((*p >> 4) & 0x0F) + '0';
138 			}
139 		} else {
140 			if (i % 2 != 0) {
141 				*calling++ = ((*p >> 0) & 0x0F) + '0';
142 				p++;
143 			} else {
144 				*calling++ = ((*p >> 4) & 0x0F) + '0';
145 			}
146 		}
147 	}
148 
149 	*called = *calling = '\0';
150 
151 	return 1 + (called_len + calling_len + 1) / 2;
152 }
153 
154 int x25_addr_aton(unsigned char *p, struct x25_address *called_addr,
155 		  struct x25_address *calling_addr)
156 {
157 	unsigned int called_len, calling_len;
158 	char *called, *calling;
159 	int i;
160 
161 	called  = called_addr->x25_addr;
162 	calling = calling_addr->x25_addr;
163 
164 	called_len  = strlen(called);
165 	calling_len = strlen(calling);
166 
167 	*p++ = (calling_len << 4) | (called_len << 0);
168 
169 	for (i = 0; i < (called_len + calling_len); i++) {
170 		if (i < called_len) {
171 			if (i % 2 != 0) {
172 				*p |= (*called++ - '0') << 0;
173 				p++;
174 			} else {
175 				*p = 0x00;
176 				*p |= (*called++ - '0') << 4;
177 			}
178 		} else {
179 			if (i % 2 != 0) {
180 				*p |= (*calling++ - '0') << 0;
181 				p++;
182 			} else {
183 				*p = 0x00;
184 				*p |= (*calling++ - '0') << 4;
185 			}
186 		}
187 	}
188 
189 	return 1 + (called_len + calling_len + 1) / 2;
190 }
191 
192 /*
193  *	Socket removal during an interrupt is now safe.
194  */
195 static void x25_remove_socket(struct sock *sk)
196 {
197 	write_lock_bh(&x25_list_lock);
198 	sk_del_node_init(sk);
199 	write_unlock_bh(&x25_list_lock);
200 }
201 
202 /*
203  *	Handle device status changes.
204  */
205 static int x25_device_event(struct notifier_block *this, unsigned long event,
206 			    void *ptr)
207 {
208 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
209 	struct x25_neigh *nb;
210 
211 	if (!net_eq(dev_net(dev), &init_net))
212 		return NOTIFY_DONE;
213 
214 	if (dev->type == ARPHRD_X25) {
215 		switch (event) {
216 		case NETDEV_REGISTER:
217 		case NETDEV_POST_TYPE_CHANGE:
218 			x25_link_device_up(dev);
219 			break;
220 		case NETDEV_DOWN:
221 			nb = x25_get_neigh(dev);
222 			if (nb) {
223 				x25_link_terminated(nb);
224 				x25_neigh_put(nb);
225 			}
226 			x25_route_device_down(dev);
227 			break;
228 		case NETDEV_PRE_TYPE_CHANGE:
229 		case NETDEV_UNREGISTER:
230 			x25_link_device_down(dev);
231 			break;
232 		case NETDEV_CHANGE:
233 			if (!netif_carrier_ok(dev)) {
234 				nb = x25_get_neigh(dev);
235 				if (nb) {
236 					x25_link_terminated(nb);
237 					x25_neigh_put(nb);
238 				}
239 			}
240 			break;
241 		}
242 	}
243 
244 	return NOTIFY_DONE;
245 }
246 
247 /*
248  *	Add a socket to the bound sockets list.
249  */
250 static void x25_insert_socket(struct sock *sk)
251 {
252 	write_lock_bh(&x25_list_lock);
253 	sk_add_node(sk, &x25_list);
254 	write_unlock_bh(&x25_list_lock);
255 }
256 
257 /*
258  *	Find a socket that wants to accept the Call Request we just
259  *	received. Check the full list for an address/cud match.
260  *	If no cuds match return the next_best thing, an address match.
261  *	Note: if a listening socket has cud set it must only get calls
262  *	with matching cud.
263  */
264 static struct sock *x25_find_listener(struct x25_address *addr,
265 					struct sk_buff *skb)
266 {
267 	struct sock *s;
268 	struct sock *next_best;
269 
270 	read_lock_bh(&x25_list_lock);
271 	next_best = NULL;
272 
273 	sk_for_each(s, &x25_list)
274 		if ((!strcmp(addr->x25_addr,
275 			x25_sk(s)->source_addr.x25_addr) ||
276 				!strcmp(x25_sk(s)->source_addr.x25_addr,
277 					null_x25_address.x25_addr)) &&
278 					s->sk_state == TCP_LISTEN) {
279 			/*
280 			 * Found a listening socket, now check the incoming
281 			 * call user data vs this sockets call user data
282 			 */
283 			if (x25_sk(s)->cudmatchlength > 0 &&
284 				skb->len >= x25_sk(s)->cudmatchlength) {
285 				if((memcmp(x25_sk(s)->calluserdata.cuddata,
286 					skb->data,
287 					x25_sk(s)->cudmatchlength)) == 0) {
288 					sock_hold(s);
289 					goto found;
290 				 }
291 			} else
292 				next_best = s;
293 		}
294 	if (next_best) {
295 		s = next_best;
296 		sock_hold(s);
297 		goto found;
298 	}
299 	s = NULL;
300 found:
301 	read_unlock_bh(&x25_list_lock);
302 	return s;
303 }
304 
305 /*
306  *	Find a connected X.25 socket given my LCI and neighbour.
307  */
308 static struct sock *__x25_find_socket(unsigned int lci, struct x25_neigh *nb)
309 {
310 	struct sock *s;
311 
312 	sk_for_each(s, &x25_list)
313 		if (x25_sk(s)->lci == lci && x25_sk(s)->neighbour == nb) {
314 			sock_hold(s);
315 			goto found;
316 		}
317 	s = NULL;
318 found:
319 	return s;
320 }
321 
322 struct sock *x25_find_socket(unsigned int lci, struct x25_neigh *nb)
323 {
324 	struct sock *s;
325 
326 	read_lock_bh(&x25_list_lock);
327 	s = __x25_find_socket(lci, nb);
328 	read_unlock_bh(&x25_list_lock);
329 	return s;
330 }
331 
332 /*
333  *	Find a unique LCI for a given device.
334  */
335 static unsigned int x25_new_lci(struct x25_neigh *nb)
336 {
337 	unsigned int lci = 1;
338 	struct sock *sk;
339 
340 	while ((sk = x25_find_socket(lci, nb)) != NULL) {
341 		sock_put(sk);
342 		if (++lci == 4096) {
343 			lci = 0;
344 			break;
345 		}
346 		cond_resched();
347 	}
348 
349 	return lci;
350 }
351 
352 /*
353  *	Deferred destroy.
354  */
355 static void __x25_destroy_socket(struct sock *);
356 
357 /*
358  *	handler for deferred kills.
359  */
360 static void x25_destroy_timer(struct timer_list *t)
361 {
362 	struct sock *sk = from_timer(sk, t, sk_timer);
363 
364 	x25_destroy_socket_from_timer(sk);
365 }
366 
367 /*
368  *	This is called from user mode and the timers. Thus it protects itself
369  *	against interrupting users but doesn't worry about being called during
370  *	work. Once it is removed from the queue no interrupt or bottom half
371  *	will touch it and we are (fairly 8-) ) safe.
372  *	Not static as it's used by the timer
373  */
374 static void __x25_destroy_socket(struct sock *sk)
375 {
376 	struct sk_buff *skb;
377 
378 	x25_stop_heartbeat(sk);
379 	x25_stop_timer(sk);
380 
381 	x25_remove_socket(sk);
382 	x25_clear_queues(sk);		/* Flush the queues */
383 
384 	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
385 		if (skb->sk != sk) {		/* A pending connection */
386 			/*
387 			 * Queue the unaccepted socket for death
388 			 */
389 			skb->sk->sk_state = TCP_LISTEN;
390 			sock_set_flag(skb->sk, SOCK_DEAD);
391 			x25_start_heartbeat(skb->sk);
392 			x25_sk(skb->sk)->state = X25_STATE_0;
393 		}
394 
395 		kfree_skb(skb);
396 	}
397 
398 	if (sk_has_allocations(sk)) {
399 		/* Defer: outstanding buffers */
400 		sk->sk_timer.expires  = jiffies + 10 * HZ;
401 		sk->sk_timer.function = x25_destroy_timer;
402 		add_timer(&sk->sk_timer);
403 	} else {
404 		/* drop last reference so sock_put will free */
405 		__sock_put(sk);
406 	}
407 }
408 
409 void x25_destroy_socket_from_timer(struct sock *sk)
410 {
411 	sock_hold(sk);
412 	bh_lock_sock(sk);
413 	__x25_destroy_socket(sk);
414 	bh_unlock_sock(sk);
415 	sock_put(sk);
416 }
417 
418 /*
419  *	Handling for system calls applied via the various interfaces to a
420  *	X.25 socket object.
421  */
422 
423 static int x25_setsockopt(struct socket *sock, int level, int optname,
424 			  sockptr_t optval, unsigned int optlen)
425 {
426 	int opt;
427 	struct sock *sk = sock->sk;
428 	int rc = -ENOPROTOOPT;
429 
430 	if (level != SOL_X25 || optname != X25_QBITINCL)
431 		goto out;
432 
433 	rc = -EINVAL;
434 	if (optlen < sizeof(int))
435 		goto out;
436 
437 	rc = -EFAULT;
438 	if (copy_from_sockptr(&opt, optval, sizeof(int)))
439 		goto out;
440 
441 	if (opt)
442 		set_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
443 	else
444 		clear_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
445 	rc = 0;
446 out:
447 	return rc;
448 }
449 
450 static int x25_getsockopt(struct socket *sock, int level, int optname,
451 			  char __user *optval, int __user *optlen)
452 {
453 	struct sock *sk = sock->sk;
454 	int val, len, rc = -ENOPROTOOPT;
455 
456 	if (level != SOL_X25 || optname != X25_QBITINCL)
457 		goto out;
458 
459 	rc = -EFAULT;
460 	if (get_user(len, optlen))
461 		goto out;
462 
463 	len = min_t(unsigned int, len, sizeof(int));
464 
465 	rc = -EINVAL;
466 	if (len < 0)
467 		goto out;
468 
469 	rc = -EFAULT;
470 	if (put_user(len, optlen))
471 		goto out;
472 
473 	val = test_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
474 	rc = copy_to_user(optval, &val, len) ? -EFAULT : 0;
475 out:
476 	return rc;
477 }
478 
479 static int x25_listen(struct socket *sock, int backlog)
480 {
481 	struct sock *sk = sock->sk;
482 	int rc = -EOPNOTSUPP;
483 
484 	lock_sock(sk);
485 	if (sock->state != SS_UNCONNECTED) {
486 		rc = -EINVAL;
487 		release_sock(sk);
488 		return rc;
489 	}
490 
491 	if (sk->sk_state != TCP_LISTEN) {
492 		memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN);
493 		sk->sk_max_ack_backlog = backlog;
494 		sk->sk_state           = TCP_LISTEN;
495 		rc = 0;
496 	}
497 	release_sock(sk);
498 
499 	return rc;
500 }
501 
502 static struct proto x25_proto = {
503 	.name	  = "X25",
504 	.owner	  = THIS_MODULE,
505 	.obj_size = sizeof(struct x25_sock),
506 };
507 
508 static struct sock *x25_alloc_socket(struct net *net, int kern)
509 {
510 	struct x25_sock *x25;
511 	struct sock *sk = sk_alloc(net, AF_X25, GFP_ATOMIC, &x25_proto, kern);
512 
513 	if (!sk)
514 		goto out;
515 
516 	sock_init_data(NULL, sk);
517 
518 	x25 = x25_sk(sk);
519 	skb_queue_head_init(&x25->ack_queue);
520 	skb_queue_head_init(&x25->fragment_queue);
521 	skb_queue_head_init(&x25->interrupt_in_queue);
522 	skb_queue_head_init(&x25->interrupt_out_queue);
523 out:
524 	return sk;
525 }
526 
527 static int x25_create(struct net *net, struct socket *sock, int protocol,
528 		      int kern)
529 {
530 	struct sock *sk;
531 	struct x25_sock *x25;
532 	int rc = -EAFNOSUPPORT;
533 
534 	if (!net_eq(net, &init_net))
535 		goto out;
536 
537 	rc = -ESOCKTNOSUPPORT;
538 	if (sock->type != SOCK_SEQPACKET)
539 		goto out;
540 
541 	rc = -EINVAL;
542 	if (protocol)
543 		goto out;
544 
545 	rc = -ENOMEM;
546 	if ((sk = x25_alloc_socket(net, kern)) == NULL)
547 		goto out;
548 
549 	x25 = x25_sk(sk);
550 
551 	sock_init_data(sock, sk);
552 
553 	x25_init_timers(sk);
554 
555 	sock->ops    = &x25_proto_ops;
556 	sk->sk_protocol = protocol;
557 	sk->sk_backlog_rcv = x25_backlog_rcv;
558 
559 	x25->t21   = sysctl_x25_call_request_timeout;
560 	x25->t22   = sysctl_x25_reset_request_timeout;
561 	x25->t23   = sysctl_x25_clear_request_timeout;
562 	x25->t2    = sysctl_x25_ack_holdback_timeout;
563 	x25->state = X25_STATE_0;
564 	x25->cudmatchlength = 0;
565 	set_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);	/* normally no cud  */
566 							/* on call accept   */
567 
568 	x25->facilities.winsize_in  = X25_DEFAULT_WINDOW_SIZE;
569 	x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
570 	x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
571 	x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
572 	x25->facilities.throughput  = 0;	/* by default don't negotiate
573 						   throughput */
574 	x25->facilities.reverse     = X25_DEFAULT_REVERSE;
575 	x25->dte_facilities.calling_len = 0;
576 	x25->dte_facilities.called_len = 0;
577 	memset(x25->dte_facilities.called_ae, '\0',
578 			sizeof(x25->dte_facilities.called_ae));
579 	memset(x25->dte_facilities.calling_ae, '\0',
580 			sizeof(x25->dte_facilities.calling_ae));
581 
582 	rc = 0;
583 out:
584 	return rc;
585 }
586 
587 static struct sock *x25_make_new(struct sock *osk)
588 {
589 	struct sock *sk = NULL;
590 	struct x25_sock *x25, *ox25;
591 
592 	if (osk->sk_type != SOCK_SEQPACKET)
593 		goto out;
594 
595 	if ((sk = x25_alloc_socket(sock_net(osk), 0)) == NULL)
596 		goto out;
597 
598 	x25 = x25_sk(sk);
599 
600 	sk->sk_type        = osk->sk_type;
601 	sk->sk_priority    = READ_ONCE(osk->sk_priority);
602 	sk->sk_protocol    = osk->sk_protocol;
603 	sk->sk_rcvbuf      = osk->sk_rcvbuf;
604 	sk->sk_sndbuf      = osk->sk_sndbuf;
605 	sk->sk_state       = TCP_ESTABLISHED;
606 	sk->sk_backlog_rcv = osk->sk_backlog_rcv;
607 	sock_copy_flags(sk, osk);
608 
609 	ox25 = x25_sk(osk);
610 	x25->t21        = ox25->t21;
611 	x25->t22        = ox25->t22;
612 	x25->t23        = ox25->t23;
613 	x25->t2         = ox25->t2;
614 	x25->flags	= ox25->flags;
615 	x25->facilities = ox25->facilities;
616 	x25->dte_facilities = ox25->dte_facilities;
617 	x25->cudmatchlength = ox25->cudmatchlength;
618 
619 	clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
620 	x25_init_timers(sk);
621 out:
622 	return sk;
623 }
624 
625 static int x25_release(struct socket *sock)
626 {
627 	struct sock *sk = sock->sk;
628 	struct x25_sock *x25;
629 
630 	if (!sk)
631 		return 0;
632 
633 	x25 = x25_sk(sk);
634 
635 	sock_hold(sk);
636 	lock_sock(sk);
637 	switch (x25->state) {
638 
639 		case X25_STATE_0:
640 		case X25_STATE_2:
641 			x25_disconnect(sk, 0, 0, 0);
642 			__x25_destroy_socket(sk);
643 			goto out;
644 
645 		case X25_STATE_1:
646 		case X25_STATE_3:
647 		case X25_STATE_4:
648 			x25_clear_queues(sk);
649 			x25_write_internal(sk, X25_CLEAR_REQUEST);
650 			x25_start_t23timer(sk);
651 			x25->state = X25_STATE_2;
652 			sk->sk_state	= TCP_CLOSE;
653 			sk->sk_shutdown	|= SEND_SHUTDOWN;
654 			sk->sk_state_change(sk);
655 			sock_set_flag(sk, SOCK_DEAD);
656 			sock_set_flag(sk, SOCK_DESTROY);
657 			break;
658 
659 		case X25_STATE_5:
660 			x25_write_internal(sk, X25_CLEAR_REQUEST);
661 			x25_disconnect(sk, 0, 0, 0);
662 			__x25_destroy_socket(sk);
663 			goto out;
664 	}
665 
666 	sock_orphan(sk);
667 out:
668 	release_sock(sk);
669 	sock_put(sk);
670 	return 0;
671 }
672 
673 static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
674 {
675 	struct sock *sk = sock->sk;
676 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
677 	int len, i, rc = 0;
678 
679 	if (addr_len != sizeof(struct sockaddr_x25) ||
680 	    addr->sx25_family != AF_X25 ||
681 	    strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) {
682 		rc = -EINVAL;
683 		goto out;
684 	}
685 
686 	/* check for the null_x25_address */
687 	if (strcmp(addr->sx25_addr.x25_addr, null_x25_address.x25_addr)) {
688 
689 		len = strlen(addr->sx25_addr.x25_addr);
690 		for (i = 0; i < len; i++) {
691 			if (!isdigit(addr->sx25_addr.x25_addr[i])) {
692 				rc = -EINVAL;
693 				goto out;
694 			}
695 		}
696 	}
697 
698 	lock_sock(sk);
699 	if (sock_flag(sk, SOCK_ZAPPED)) {
700 		x25_sk(sk)->source_addr = addr->sx25_addr;
701 		x25_insert_socket(sk);
702 		sock_reset_flag(sk, SOCK_ZAPPED);
703 	} else {
704 		rc = -EINVAL;
705 	}
706 	release_sock(sk);
707 	SOCK_DEBUG(sk, "x25_bind: socket is bound\n");
708 out:
709 	return rc;
710 }
711 
712 static int x25_wait_for_connection_establishment(struct sock *sk)
713 {
714 	DECLARE_WAITQUEUE(wait, current);
715 	int rc;
716 
717 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
718 	for (;;) {
719 		__set_current_state(TASK_INTERRUPTIBLE);
720 		rc = -ERESTARTSYS;
721 		if (signal_pending(current))
722 			break;
723 		rc = sock_error(sk);
724 		if (rc) {
725 			sk->sk_socket->state = SS_UNCONNECTED;
726 			break;
727 		}
728 		rc = -ENOTCONN;
729 		if (sk->sk_state == TCP_CLOSE) {
730 			sk->sk_socket->state = SS_UNCONNECTED;
731 			break;
732 		}
733 		rc = 0;
734 		if (sk->sk_state != TCP_ESTABLISHED) {
735 			release_sock(sk);
736 			schedule();
737 			lock_sock(sk);
738 		} else
739 			break;
740 	}
741 	__set_current_state(TASK_RUNNING);
742 	remove_wait_queue(sk_sleep(sk), &wait);
743 	return rc;
744 }
745 
746 static int x25_connect(struct socket *sock, struct sockaddr *uaddr,
747 		       int addr_len, int flags)
748 {
749 	struct sock *sk = sock->sk;
750 	struct x25_sock *x25 = x25_sk(sk);
751 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
752 	struct x25_route *rt;
753 	int rc = 0;
754 
755 	lock_sock(sk);
756 	if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
757 		sock->state = SS_CONNECTED;
758 		goto out; /* Connect completed during a ERESTARTSYS event */
759 	}
760 
761 	rc = -ECONNREFUSED;
762 	if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
763 		sock->state = SS_UNCONNECTED;
764 		goto out;
765 	}
766 
767 	rc = -EISCONN;	/* No reconnect on a seqpacket socket */
768 	if (sk->sk_state == TCP_ESTABLISHED)
769 		goto out;
770 
771 	rc = -EALREADY;	/* Do nothing if call is already in progress */
772 	if (sk->sk_state == TCP_SYN_SENT)
773 		goto out;
774 
775 	sk->sk_state   = TCP_CLOSE;
776 	sock->state = SS_UNCONNECTED;
777 
778 	rc = -EINVAL;
779 	if (addr_len != sizeof(struct sockaddr_x25) ||
780 	    addr->sx25_family != AF_X25 ||
781 	    strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN)
782 		goto out;
783 
784 	rc = -ENETUNREACH;
785 	rt = x25_get_route(&addr->sx25_addr);
786 	if (!rt)
787 		goto out;
788 
789 	x25->neighbour = x25_get_neigh(rt->dev);
790 	if (!x25->neighbour)
791 		goto out_put_route;
792 
793 	x25_limit_facilities(&x25->facilities, x25->neighbour);
794 
795 	x25->lci = x25_new_lci(x25->neighbour);
796 	if (!x25->lci)
797 		goto out_put_neigh;
798 
799 	rc = -EINVAL;
800 	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
801 		goto out_put_neigh;
802 
803 	if (!strcmp(x25->source_addr.x25_addr, null_x25_address.x25_addr))
804 		memset(&x25->source_addr, '\0', X25_ADDR_LEN);
805 
806 	x25->dest_addr = addr->sx25_addr;
807 
808 	/* Move to connecting socket, start sending Connect Requests */
809 	sock->state   = SS_CONNECTING;
810 	sk->sk_state  = TCP_SYN_SENT;
811 
812 	x25->state = X25_STATE_1;
813 
814 	x25_write_internal(sk, X25_CALL_REQUEST);
815 
816 	x25_start_heartbeat(sk);
817 	x25_start_t21timer(sk);
818 
819 	/* Now the loop */
820 	rc = -EINPROGRESS;
821 	if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK))
822 		goto out;
823 
824 	rc = x25_wait_for_connection_establishment(sk);
825 	if (rc)
826 		goto out_put_neigh;
827 
828 	sock->state = SS_CONNECTED;
829 	rc = 0;
830 out_put_neigh:
831 	if (rc && x25->neighbour) {
832 		read_lock_bh(&x25_list_lock);
833 		x25_neigh_put(x25->neighbour);
834 		x25->neighbour = NULL;
835 		read_unlock_bh(&x25_list_lock);
836 		x25->state = X25_STATE_0;
837 	}
838 out_put_route:
839 	x25_route_put(rt);
840 out:
841 	release_sock(sk);
842 	return rc;
843 }
844 
845 static int x25_wait_for_data(struct sock *sk, long timeout)
846 {
847 	DECLARE_WAITQUEUE(wait, current);
848 	int rc = 0;
849 
850 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
851 	for (;;) {
852 		__set_current_state(TASK_INTERRUPTIBLE);
853 		if (sk->sk_shutdown & RCV_SHUTDOWN)
854 			break;
855 		rc = -ERESTARTSYS;
856 		if (signal_pending(current))
857 			break;
858 		rc = -EAGAIN;
859 		if (!timeout)
860 			break;
861 		rc = 0;
862 		if (skb_queue_empty(&sk->sk_receive_queue)) {
863 			release_sock(sk);
864 			timeout = schedule_timeout(timeout);
865 			lock_sock(sk);
866 		} else
867 			break;
868 	}
869 	__set_current_state(TASK_RUNNING);
870 	remove_wait_queue(sk_sleep(sk), &wait);
871 	return rc;
872 }
873 
874 static int x25_accept(struct socket *sock, struct socket *newsock, int flags,
875 		      bool kern)
876 {
877 	struct sock *sk = sock->sk;
878 	struct sock *newsk;
879 	struct sk_buff *skb;
880 	int rc = -EINVAL;
881 
882 	if (!sk)
883 		goto out;
884 
885 	rc = -EOPNOTSUPP;
886 	if (sk->sk_type != SOCK_SEQPACKET)
887 		goto out;
888 
889 	lock_sock(sk);
890 	rc = -EINVAL;
891 	if (sk->sk_state != TCP_LISTEN)
892 		goto out2;
893 
894 	rc = x25_wait_for_data(sk, sk->sk_rcvtimeo);
895 	if (rc)
896 		goto out2;
897 	skb = skb_dequeue(&sk->sk_receive_queue);
898 	rc = -EINVAL;
899 	if (!skb->sk)
900 		goto out2;
901 	newsk		 = skb->sk;
902 	sock_graft(newsk, newsock);
903 
904 	/* Now attach up the new socket */
905 	skb->sk = NULL;
906 	kfree_skb(skb);
907 	sk_acceptq_removed(sk);
908 	newsock->state = SS_CONNECTED;
909 	rc = 0;
910 out2:
911 	release_sock(sk);
912 out:
913 	return rc;
914 }
915 
916 static int x25_getname(struct socket *sock, struct sockaddr *uaddr,
917 		       int peer)
918 {
919 	struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)uaddr;
920 	struct sock *sk = sock->sk;
921 	struct x25_sock *x25 = x25_sk(sk);
922 	int rc = 0;
923 
924 	if (peer) {
925 		if (sk->sk_state != TCP_ESTABLISHED) {
926 			rc = -ENOTCONN;
927 			goto out;
928 		}
929 		sx25->sx25_addr = x25->dest_addr;
930 	} else
931 		sx25->sx25_addr = x25->source_addr;
932 
933 	sx25->sx25_family = AF_X25;
934 	rc = sizeof(*sx25);
935 
936 out:
937 	return rc;
938 }
939 
940 int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
941 			unsigned int lci)
942 {
943 	struct sock *sk;
944 	struct sock *make;
945 	struct x25_sock *makex25;
946 	struct x25_address source_addr, dest_addr;
947 	struct x25_facilities facilities;
948 	struct x25_dte_facilities dte_facilities;
949 	int len, addr_len, rc;
950 
951 	/*
952 	 *	Remove the LCI and frame type.
953 	 */
954 	skb_pull(skb, X25_STD_MIN_LEN);
955 
956 	/*
957 	 *	Extract the X.25 addresses and convert them to ASCII strings,
958 	 *	and remove them.
959 	 *
960 	 *	Address block is mandatory in call request packets
961 	 */
962 	addr_len = x25_parse_address_block(skb, &source_addr, &dest_addr);
963 	if (addr_len <= 0)
964 		goto out_clear_request;
965 	skb_pull(skb, addr_len);
966 
967 	/*
968 	 *	Get the length of the facilities, skip past them for the moment
969 	 *	get the call user data because this is needed to determine
970 	 *	the correct listener
971 	 *
972 	 *	Facilities length is mandatory in call request packets
973 	 */
974 	if (!pskb_may_pull(skb, 1))
975 		goto out_clear_request;
976 	len = skb->data[0] + 1;
977 	if (!pskb_may_pull(skb, len))
978 		goto out_clear_request;
979 	skb_pull(skb,len);
980 
981 	/*
982 	 *	Ensure that the amount of call user data is valid.
983 	 */
984 	if (skb->len > X25_MAX_CUD_LEN)
985 		goto out_clear_request;
986 
987 	/*
988 	 *	Get all the call user data so it can be used in
989 	 *	x25_find_listener and skb_copy_from_linear_data up ahead.
990 	 */
991 	if (!pskb_may_pull(skb, skb->len))
992 		goto out_clear_request;
993 
994 	/*
995 	 *	Find a listener for the particular address/cud pair.
996 	 */
997 	sk = x25_find_listener(&source_addr,skb);
998 	skb_push(skb,len);
999 
1000 	if (sk != NULL && sk_acceptq_is_full(sk)) {
1001 		goto out_sock_put;
1002 	}
1003 
1004 	/*
1005 	 *	We dont have any listeners for this incoming call.
1006 	 *	Try forwarding it.
1007 	 */
1008 	if (sk == NULL) {
1009 		skb_push(skb, addr_len + X25_STD_MIN_LEN);
1010 		if (sysctl_x25_forward &&
1011 				x25_forward_call(&dest_addr, nb, skb, lci) > 0)
1012 		{
1013 			/* Call was forwarded, dont process it any more */
1014 			kfree_skb(skb);
1015 			rc = 1;
1016 			goto out;
1017 		} else {
1018 			/* No listeners, can't forward, clear the call */
1019 			goto out_clear_request;
1020 		}
1021 	}
1022 
1023 	/*
1024 	 *	Try to reach a compromise on the requested facilities.
1025 	 */
1026 	len = x25_negotiate_facilities(skb, sk, &facilities, &dte_facilities);
1027 	if (len == -1)
1028 		goto out_sock_put;
1029 
1030 	/*
1031 	 * current neighbour/link might impose additional limits
1032 	 * on certain facilities
1033 	 */
1034 
1035 	x25_limit_facilities(&facilities, nb);
1036 
1037 	/*
1038 	 *	Try to create a new socket.
1039 	 */
1040 	make = x25_make_new(sk);
1041 	if (!make)
1042 		goto out_sock_put;
1043 
1044 	/*
1045 	 *	Remove the facilities
1046 	 */
1047 	skb_pull(skb, len);
1048 
1049 	skb->sk     = make;
1050 	make->sk_state = TCP_ESTABLISHED;
1051 
1052 	makex25 = x25_sk(make);
1053 	makex25->lci           = lci;
1054 	makex25->dest_addr     = dest_addr;
1055 	makex25->source_addr   = source_addr;
1056 	x25_neigh_hold(nb);
1057 	makex25->neighbour     = nb;
1058 	makex25->facilities    = facilities;
1059 	makex25->dte_facilities= dte_facilities;
1060 	makex25->vc_facil_mask = x25_sk(sk)->vc_facil_mask;
1061 	/* ensure no reverse facil on accept */
1062 	makex25->vc_facil_mask &= ~X25_MASK_REVERSE;
1063 	/* ensure no calling address extension on accept */
1064 	makex25->vc_facil_mask &= ~X25_MASK_CALLING_AE;
1065 	makex25->cudmatchlength = x25_sk(sk)->cudmatchlength;
1066 
1067 	/* Normally all calls are accepted immediately */
1068 	if (test_bit(X25_ACCPT_APPRV_FLAG, &makex25->flags)) {
1069 		x25_write_internal(make, X25_CALL_ACCEPTED);
1070 		makex25->state = X25_STATE_3;
1071 	} else {
1072 		makex25->state = X25_STATE_5;
1073 	}
1074 
1075 	/*
1076 	 *	Incoming Call User Data.
1077 	 */
1078 	skb_copy_from_linear_data(skb, makex25->calluserdata.cuddata, skb->len);
1079 	makex25->calluserdata.cudlength = skb->len;
1080 
1081 	sk_acceptq_added(sk);
1082 
1083 	x25_insert_socket(make);
1084 
1085 	skb_queue_head(&sk->sk_receive_queue, skb);
1086 
1087 	x25_start_heartbeat(make);
1088 
1089 	if (!sock_flag(sk, SOCK_DEAD))
1090 		sk->sk_data_ready(sk);
1091 	rc = 1;
1092 	sock_put(sk);
1093 out:
1094 	return rc;
1095 out_sock_put:
1096 	sock_put(sk);
1097 out_clear_request:
1098 	rc = 0;
1099 	x25_transmit_clear_request(nb, lci, 0x01);
1100 	goto out;
1101 }
1102 
1103 static int x25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1104 {
1105 	struct sock *sk = sock->sk;
1106 	struct x25_sock *x25 = x25_sk(sk);
1107 	DECLARE_SOCKADDR(struct sockaddr_x25 *, usx25, msg->msg_name);
1108 	struct sockaddr_x25 sx25;
1109 	struct sk_buff *skb;
1110 	unsigned char *asmptr;
1111 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1112 	size_t size;
1113 	int qbit = 0, rc = -EINVAL;
1114 
1115 	lock_sock(sk);
1116 	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_OOB|MSG_EOR|MSG_CMSG_COMPAT))
1117 		goto out;
1118 
1119 	/* we currently don't support segmented records at the user interface */
1120 	if (!(msg->msg_flags & (MSG_EOR|MSG_OOB)))
1121 		goto out;
1122 
1123 	rc = -EADDRNOTAVAIL;
1124 	if (sock_flag(sk, SOCK_ZAPPED))
1125 		goto out;
1126 
1127 	rc = -EPIPE;
1128 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1129 		send_sig(SIGPIPE, current, 0);
1130 		goto out;
1131 	}
1132 
1133 	rc = -ENETUNREACH;
1134 	if (!x25->neighbour)
1135 		goto out;
1136 
1137 	if (usx25) {
1138 		rc = -EINVAL;
1139 		if (msg->msg_namelen < sizeof(sx25))
1140 			goto out;
1141 		memcpy(&sx25, usx25, sizeof(sx25));
1142 		rc = -EISCONN;
1143 		if (strcmp(x25->dest_addr.x25_addr, sx25.sx25_addr.x25_addr))
1144 			goto out;
1145 		rc = -EINVAL;
1146 		if (sx25.sx25_family != AF_X25)
1147 			goto out;
1148 	} else {
1149 		/*
1150 		 *	FIXME 1003.1g - if the socket is like this because
1151 		 *	it has become closed (not started closed) we ought
1152 		 *	to SIGPIPE, EPIPE;
1153 		 */
1154 		rc = -ENOTCONN;
1155 		if (sk->sk_state != TCP_ESTABLISHED)
1156 			goto out;
1157 
1158 		sx25.sx25_family = AF_X25;
1159 		sx25.sx25_addr   = x25->dest_addr;
1160 	}
1161 
1162 	/* Sanity check the packet size */
1163 	if (len > 65535) {
1164 		rc = -EMSGSIZE;
1165 		goto out;
1166 	}
1167 
1168 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: Addresses built.\n");
1169 
1170 	/* Build a packet */
1171 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: building packet.\n");
1172 
1173 	if ((msg->msg_flags & MSG_OOB) && len > 32)
1174 		len = 32;
1175 
1176 	size = len + X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
1177 
1178 	release_sock(sk);
1179 	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
1180 	lock_sock(sk);
1181 	if (!skb)
1182 		goto out;
1183 	X25_SKB_CB(skb)->flags = msg->msg_flags;
1184 
1185 	skb_reserve(skb, X25_MAX_L2_LEN + X25_EXT_MIN_LEN);
1186 
1187 	/*
1188 	 *	Put the data on the end
1189 	 */
1190 	SOCK_DEBUG(sk, "x25_sendmsg: Copying user data\n");
1191 
1192 	skb_reset_transport_header(skb);
1193 	skb_put(skb, len);
1194 
1195 	rc = memcpy_from_msg(skb_transport_header(skb), msg, len);
1196 	if (rc)
1197 		goto out_kfree_skb;
1198 
1199 	/*
1200 	 *	If the Q BIT Include socket option is in force, the first
1201 	 *	byte of the user data is the logical value of the Q Bit.
1202 	 */
1203 	if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1204 		if (!pskb_may_pull(skb, 1))
1205 			goto out_kfree_skb;
1206 
1207 		qbit = skb->data[0];
1208 		skb_pull(skb, 1);
1209 	}
1210 
1211 	/*
1212 	 *	Push down the X.25 header
1213 	 */
1214 	SOCK_DEBUG(sk, "x25_sendmsg: Building X.25 Header.\n");
1215 
1216 	if (msg->msg_flags & MSG_OOB) {
1217 		if (x25->neighbour->extended) {
1218 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1219 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1220 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1221 			*asmptr++ = X25_INTERRUPT;
1222 		} else {
1223 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1224 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1225 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1226 			*asmptr++ = X25_INTERRUPT;
1227 		}
1228 	} else {
1229 		if (x25->neighbour->extended) {
1230 			/* Build an Extended X.25 header */
1231 			asmptr    = skb_push(skb, X25_EXT_MIN_LEN);
1232 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1233 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1234 			*asmptr++ = X25_DATA;
1235 			*asmptr++ = X25_DATA;
1236 		} else {
1237 			/* Build an Standard X.25 header */
1238 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1239 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1240 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1241 			*asmptr++ = X25_DATA;
1242 		}
1243 
1244 		if (qbit)
1245 			skb->data[0] |= X25_Q_BIT;
1246 	}
1247 
1248 	SOCK_DEBUG(sk, "x25_sendmsg: Built header.\n");
1249 	SOCK_DEBUG(sk, "x25_sendmsg: Transmitting buffer\n");
1250 
1251 	rc = -ENOTCONN;
1252 	if (sk->sk_state != TCP_ESTABLISHED)
1253 		goto out_kfree_skb;
1254 
1255 	if (msg->msg_flags & MSG_OOB)
1256 		skb_queue_tail(&x25->interrupt_out_queue, skb);
1257 	else {
1258 		rc = x25_output(sk, skb);
1259 		len = rc;
1260 		if (rc < 0)
1261 			kfree_skb(skb);
1262 		else if (test_bit(X25_Q_BIT_FLAG, &x25->flags))
1263 			len++;
1264 	}
1265 
1266 	x25_kick(sk);
1267 	rc = len;
1268 out:
1269 	release_sock(sk);
1270 	return rc;
1271 out_kfree_skb:
1272 	kfree_skb(skb);
1273 	goto out;
1274 }
1275 
1276 
1277 static int x25_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1278 		       int flags)
1279 {
1280 	struct sock *sk = sock->sk;
1281 	struct x25_sock *x25 = x25_sk(sk);
1282 	DECLARE_SOCKADDR(struct sockaddr_x25 *, sx25, msg->msg_name);
1283 	size_t copied;
1284 	int qbit, header_len;
1285 	struct sk_buff *skb;
1286 	unsigned char *asmptr;
1287 	int rc = -ENOTCONN;
1288 
1289 	lock_sock(sk);
1290 
1291 	if (x25->neighbour == NULL)
1292 		goto out;
1293 
1294 	header_len = x25->neighbour->extended ?
1295 		X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
1296 
1297 	/*
1298 	 * This works for seqpacket too. The receiver has ordered the queue for
1299 	 * us! We do one quick check first though
1300 	 */
1301 	if (sk->sk_state != TCP_ESTABLISHED)
1302 		goto out;
1303 
1304 	if (flags & MSG_OOB) {
1305 		rc = -EINVAL;
1306 		if (sock_flag(sk, SOCK_URGINLINE) ||
1307 		    !skb_peek(&x25->interrupt_in_queue))
1308 			goto out;
1309 
1310 		skb = skb_dequeue(&x25->interrupt_in_queue);
1311 
1312 		if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
1313 			goto out_free_dgram;
1314 
1315 		skb_pull(skb, X25_STD_MIN_LEN);
1316 
1317 		/*
1318 		 *	No Q bit information on Interrupt data.
1319 		 */
1320 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1321 			asmptr  = skb_push(skb, 1);
1322 			*asmptr = 0x00;
1323 		}
1324 
1325 		msg->msg_flags |= MSG_OOB;
1326 	} else {
1327 		/* Now we can treat all alike */
1328 		release_sock(sk);
1329 		skb = skb_recv_datagram(sk, flags, &rc);
1330 		lock_sock(sk);
1331 		if (!skb)
1332 			goto out;
1333 
1334 		if (!pskb_may_pull(skb, header_len))
1335 			goto out_free_dgram;
1336 
1337 		qbit = (skb->data[0] & X25_Q_BIT) == X25_Q_BIT;
1338 
1339 		skb_pull(skb, header_len);
1340 
1341 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1342 			asmptr  = skb_push(skb, 1);
1343 			*asmptr = qbit;
1344 		}
1345 	}
1346 
1347 	skb_reset_transport_header(skb);
1348 	copied = skb->len;
1349 
1350 	if (copied > size) {
1351 		copied = size;
1352 		msg->msg_flags |= MSG_TRUNC;
1353 	}
1354 
1355 	/* Currently, each datagram always contains a complete record */
1356 	msg->msg_flags |= MSG_EOR;
1357 
1358 	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
1359 	if (rc)
1360 		goto out_free_dgram;
1361 
1362 	if (sx25) {
1363 		sx25->sx25_family = AF_X25;
1364 		sx25->sx25_addr   = x25->dest_addr;
1365 		msg->msg_namelen = sizeof(*sx25);
1366 	}
1367 
1368 	x25_check_rbuf(sk);
1369 	rc = copied;
1370 out_free_dgram:
1371 	skb_free_datagram(sk, skb);
1372 out:
1373 	release_sock(sk);
1374 	return rc;
1375 }
1376 
1377 
1378 static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1379 {
1380 	struct sock *sk = sock->sk;
1381 	struct x25_sock *x25 = x25_sk(sk);
1382 	void __user *argp = (void __user *)arg;
1383 	int rc;
1384 
1385 	switch (cmd) {
1386 	case TIOCOUTQ: {
1387 		int amount;
1388 
1389 		amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1390 		if (amount < 0)
1391 			amount = 0;
1392 		rc = put_user(amount, (unsigned int __user *)argp);
1393 		break;
1394 	}
1395 
1396 	case TIOCINQ: {
1397 		struct sk_buff *skb;
1398 		int amount = 0;
1399 		/*
1400 		 * These two are safe on a single CPU system as
1401 		 * only user tasks fiddle here
1402 		 */
1403 		lock_sock(sk);
1404 		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1405 			amount = skb->len;
1406 		release_sock(sk);
1407 		rc = put_user(amount, (unsigned int __user *)argp);
1408 		break;
1409 	}
1410 
1411 	case SIOCGIFADDR:
1412 	case SIOCSIFADDR:
1413 	case SIOCGIFDSTADDR:
1414 	case SIOCSIFDSTADDR:
1415 	case SIOCGIFBRDADDR:
1416 	case SIOCSIFBRDADDR:
1417 	case SIOCGIFNETMASK:
1418 	case SIOCSIFNETMASK:
1419 	case SIOCGIFMETRIC:
1420 	case SIOCSIFMETRIC:
1421 		rc = -EINVAL;
1422 		break;
1423 	case SIOCADDRT:
1424 	case SIOCDELRT:
1425 		rc = -EPERM;
1426 		if (!capable(CAP_NET_ADMIN))
1427 			break;
1428 		rc = x25_route_ioctl(cmd, argp);
1429 		break;
1430 	case SIOCX25GSUBSCRIP:
1431 		rc = x25_subscr_ioctl(cmd, argp);
1432 		break;
1433 	case SIOCX25SSUBSCRIP:
1434 		rc = -EPERM;
1435 		if (!capable(CAP_NET_ADMIN))
1436 			break;
1437 		rc = x25_subscr_ioctl(cmd, argp);
1438 		break;
1439 	case SIOCX25GFACILITIES: {
1440 		lock_sock(sk);
1441 		rc = copy_to_user(argp, &x25->facilities,
1442 				  sizeof(x25->facilities))
1443 			? -EFAULT : 0;
1444 		release_sock(sk);
1445 		break;
1446 	}
1447 
1448 	case SIOCX25SFACILITIES: {
1449 		struct x25_facilities facilities;
1450 		rc = -EFAULT;
1451 		if (copy_from_user(&facilities, argp, sizeof(facilities)))
1452 			break;
1453 		rc = -EINVAL;
1454 		lock_sock(sk);
1455 		if (sk->sk_state != TCP_LISTEN &&
1456 		    sk->sk_state != TCP_CLOSE)
1457 			goto out_fac_release;
1458 		if (facilities.pacsize_in < X25_PS16 ||
1459 		    facilities.pacsize_in > X25_PS4096)
1460 			goto out_fac_release;
1461 		if (facilities.pacsize_out < X25_PS16 ||
1462 		    facilities.pacsize_out > X25_PS4096)
1463 			goto out_fac_release;
1464 		if (facilities.winsize_in < 1 ||
1465 		    facilities.winsize_in > 127)
1466 			goto out_fac_release;
1467 		if (facilities.throughput) {
1468 			int out = facilities.throughput & 0xf0;
1469 			int in  = facilities.throughput & 0x0f;
1470 			if (!out)
1471 				facilities.throughput |=
1472 					X25_DEFAULT_THROUGHPUT << 4;
1473 			else if (out < 0x30 || out > 0xD0)
1474 				goto out_fac_release;
1475 			if (!in)
1476 				facilities.throughput |=
1477 					X25_DEFAULT_THROUGHPUT;
1478 			else if (in < 0x03 || in > 0x0D)
1479 				goto out_fac_release;
1480 		}
1481 		if (facilities.reverse &&
1482 		    (facilities.reverse & 0x81) != 0x81)
1483 			goto out_fac_release;
1484 		x25->facilities = facilities;
1485 		rc = 0;
1486 out_fac_release:
1487 		release_sock(sk);
1488 		break;
1489 	}
1490 
1491 	case SIOCX25GDTEFACILITIES: {
1492 		lock_sock(sk);
1493 		rc = copy_to_user(argp, &x25->dte_facilities,
1494 				  sizeof(x25->dte_facilities));
1495 		release_sock(sk);
1496 		if (rc)
1497 			rc = -EFAULT;
1498 		break;
1499 	}
1500 
1501 	case SIOCX25SDTEFACILITIES: {
1502 		struct x25_dte_facilities dtefacs;
1503 		rc = -EFAULT;
1504 		if (copy_from_user(&dtefacs, argp, sizeof(dtefacs)))
1505 			break;
1506 		rc = -EINVAL;
1507 		lock_sock(sk);
1508 		if (sk->sk_state != TCP_LISTEN &&
1509 		    sk->sk_state != TCP_CLOSE)
1510 			goto out_dtefac_release;
1511 		if (dtefacs.calling_len > X25_MAX_AE_LEN)
1512 			goto out_dtefac_release;
1513 		if (dtefacs.called_len > X25_MAX_AE_LEN)
1514 			goto out_dtefac_release;
1515 		x25->dte_facilities = dtefacs;
1516 		rc = 0;
1517 out_dtefac_release:
1518 		release_sock(sk);
1519 		break;
1520 	}
1521 
1522 	case SIOCX25GCALLUSERDATA: {
1523 		lock_sock(sk);
1524 		rc = copy_to_user(argp, &x25->calluserdata,
1525 				  sizeof(x25->calluserdata))
1526 			? -EFAULT : 0;
1527 		release_sock(sk);
1528 		break;
1529 	}
1530 
1531 	case SIOCX25SCALLUSERDATA: {
1532 		struct x25_calluserdata calluserdata;
1533 
1534 		rc = -EFAULT;
1535 		if (copy_from_user(&calluserdata, argp, sizeof(calluserdata)))
1536 			break;
1537 		rc = -EINVAL;
1538 		if (calluserdata.cudlength > X25_MAX_CUD_LEN)
1539 			break;
1540 		lock_sock(sk);
1541 		x25->calluserdata = calluserdata;
1542 		release_sock(sk);
1543 		rc = 0;
1544 		break;
1545 	}
1546 
1547 	case SIOCX25GCAUSEDIAG: {
1548 		lock_sock(sk);
1549 		rc = copy_to_user(argp, &x25->causediag, sizeof(x25->causediag))
1550 			? -EFAULT : 0;
1551 		release_sock(sk);
1552 		break;
1553 	}
1554 
1555 	case SIOCX25SCAUSEDIAG: {
1556 		struct x25_causediag causediag;
1557 		rc = -EFAULT;
1558 		if (copy_from_user(&causediag, argp, sizeof(causediag)))
1559 			break;
1560 		lock_sock(sk);
1561 		x25->causediag = causediag;
1562 		release_sock(sk);
1563 		rc = 0;
1564 		break;
1565 
1566 	}
1567 
1568 	case SIOCX25SCUDMATCHLEN: {
1569 		struct x25_subaddr sub_addr;
1570 		rc = -EINVAL;
1571 		lock_sock(sk);
1572 		if(sk->sk_state != TCP_CLOSE)
1573 			goto out_cud_release;
1574 		rc = -EFAULT;
1575 		if (copy_from_user(&sub_addr, argp,
1576 				   sizeof(sub_addr)))
1577 			goto out_cud_release;
1578 		rc = -EINVAL;
1579 		if (sub_addr.cudmatchlength > X25_MAX_CUD_LEN)
1580 			goto out_cud_release;
1581 		x25->cudmatchlength = sub_addr.cudmatchlength;
1582 		rc = 0;
1583 out_cud_release:
1584 		release_sock(sk);
1585 		break;
1586 	}
1587 
1588 	case SIOCX25CALLACCPTAPPRV: {
1589 		rc = -EINVAL;
1590 		lock_sock(sk);
1591 		if (sk->sk_state == TCP_CLOSE) {
1592 			clear_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);
1593 			rc = 0;
1594 		}
1595 		release_sock(sk);
1596 		break;
1597 	}
1598 
1599 	case SIOCX25SENDCALLACCPT:  {
1600 		rc = -EINVAL;
1601 		lock_sock(sk);
1602 		if (sk->sk_state != TCP_ESTABLISHED)
1603 			goto out_sendcallaccpt_release;
1604 		/* must call accptapprv above */
1605 		if (test_bit(X25_ACCPT_APPRV_FLAG, &x25->flags))
1606 			goto out_sendcallaccpt_release;
1607 		x25_write_internal(sk, X25_CALL_ACCEPTED);
1608 		x25->state = X25_STATE_3;
1609 		rc = 0;
1610 out_sendcallaccpt_release:
1611 		release_sock(sk);
1612 		break;
1613 	}
1614 
1615 	default:
1616 		rc = -ENOIOCTLCMD;
1617 		break;
1618 	}
1619 
1620 	return rc;
1621 }
1622 
1623 static const struct net_proto_family x25_family_ops = {
1624 	.family =	AF_X25,
1625 	.create =	x25_create,
1626 	.owner	=	THIS_MODULE,
1627 };
1628 
1629 #ifdef CONFIG_COMPAT
1630 static int compat_x25_subscr_ioctl(unsigned int cmd,
1631 		struct compat_x25_subscrip_struct __user *x25_subscr32)
1632 {
1633 	struct compat_x25_subscrip_struct x25_subscr;
1634 	struct x25_neigh *nb;
1635 	struct net_device *dev;
1636 	int rc = -EINVAL;
1637 
1638 	rc = -EFAULT;
1639 	if (copy_from_user(&x25_subscr, x25_subscr32, sizeof(*x25_subscr32)))
1640 		goto out;
1641 
1642 	rc = -EINVAL;
1643 	dev = x25_dev_get(x25_subscr.device);
1644 	if (dev == NULL)
1645 		goto out;
1646 
1647 	nb = x25_get_neigh(dev);
1648 	if (nb == NULL)
1649 		goto out_dev_put;
1650 
1651 	dev_put(dev);
1652 
1653 	if (cmd == SIOCX25GSUBSCRIP) {
1654 		read_lock_bh(&x25_neigh_list_lock);
1655 		x25_subscr.extended = nb->extended;
1656 		x25_subscr.global_facil_mask = nb->global_facil_mask;
1657 		read_unlock_bh(&x25_neigh_list_lock);
1658 		rc = copy_to_user(x25_subscr32, &x25_subscr,
1659 				sizeof(*x25_subscr32)) ? -EFAULT : 0;
1660 	} else {
1661 		rc = -EINVAL;
1662 		if (x25_subscr.extended == 0 || x25_subscr.extended == 1) {
1663 			rc = 0;
1664 			write_lock_bh(&x25_neigh_list_lock);
1665 			nb->extended = x25_subscr.extended;
1666 			nb->global_facil_mask = x25_subscr.global_facil_mask;
1667 			write_unlock_bh(&x25_neigh_list_lock);
1668 		}
1669 	}
1670 	x25_neigh_put(nb);
1671 out:
1672 	return rc;
1673 out_dev_put:
1674 	dev_put(dev);
1675 	goto out;
1676 }
1677 
1678 static int compat_x25_ioctl(struct socket *sock, unsigned int cmd,
1679 				unsigned long arg)
1680 {
1681 	void __user *argp = compat_ptr(arg);
1682 	int rc = -ENOIOCTLCMD;
1683 
1684 	switch(cmd) {
1685 	case TIOCOUTQ:
1686 	case TIOCINQ:
1687 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1688 		break;
1689 	case SIOCGIFADDR:
1690 	case SIOCSIFADDR:
1691 	case SIOCGIFDSTADDR:
1692 	case SIOCSIFDSTADDR:
1693 	case SIOCGIFBRDADDR:
1694 	case SIOCSIFBRDADDR:
1695 	case SIOCGIFNETMASK:
1696 	case SIOCSIFNETMASK:
1697 	case SIOCGIFMETRIC:
1698 	case SIOCSIFMETRIC:
1699 		rc = -EINVAL;
1700 		break;
1701 	case SIOCADDRT:
1702 	case SIOCDELRT:
1703 		rc = -EPERM;
1704 		if (!capable(CAP_NET_ADMIN))
1705 			break;
1706 		rc = x25_route_ioctl(cmd, argp);
1707 		break;
1708 	case SIOCX25GSUBSCRIP:
1709 		rc = compat_x25_subscr_ioctl(cmd, argp);
1710 		break;
1711 	case SIOCX25SSUBSCRIP:
1712 		rc = -EPERM;
1713 		if (!capable(CAP_NET_ADMIN))
1714 			break;
1715 		rc = compat_x25_subscr_ioctl(cmd, argp);
1716 		break;
1717 	case SIOCX25GFACILITIES:
1718 	case SIOCX25SFACILITIES:
1719 	case SIOCX25GDTEFACILITIES:
1720 	case SIOCX25SDTEFACILITIES:
1721 	case SIOCX25GCALLUSERDATA:
1722 	case SIOCX25SCALLUSERDATA:
1723 	case SIOCX25GCAUSEDIAG:
1724 	case SIOCX25SCAUSEDIAG:
1725 	case SIOCX25SCUDMATCHLEN:
1726 	case SIOCX25CALLACCPTAPPRV:
1727 	case SIOCX25SENDCALLACCPT:
1728 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1729 		break;
1730 	default:
1731 		rc = -ENOIOCTLCMD;
1732 		break;
1733 	}
1734 	return rc;
1735 }
1736 #endif
1737 
1738 static const struct proto_ops x25_proto_ops = {
1739 	.family =	AF_X25,
1740 	.owner =	THIS_MODULE,
1741 	.release =	x25_release,
1742 	.bind =		x25_bind,
1743 	.connect =	x25_connect,
1744 	.socketpair =	sock_no_socketpair,
1745 	.accept =	x25_accept,
1746 	.getname =	x25_getname,
1747 	.poll =		datagram_poll,
1748 	.ioctl =	x25_ioctl,
1749 #ifdef CONFIG_COMPAT
1750 	.compat_ioctl = compat_x25_ioctl,
1751 #endif
1752 	.gettstamp =	sock_gettstamp,
1753 	.listen =	x25_listen,
1754 	.shutdown =	sock_no_shutdown,
1755 	.setsockopt =	x25_setsockopt,
1756 	.getsockopt =	x25_getsockopt,
1757 	.sendmsg =	x25_sendmsg,
1758 	.recvmsg =	x25_recvmsg,
1759 	.mmap =		sock_no_mmap,
1760 };
1761 
1762 static struct packet_type x25_packet_type __read_mostly = {
1763 	.type =	cpu_to_be16(ETH_P_X25),
1764 	.func =	x25_lapb_receive_frame,
1765 };
1766 
1767 static struct notifier_block x25_dev_notifier = {
1768 	.notifier_call = x25_device_event,
1769 };
1770 
1771 void x25_kill_by_neigh(struct x25_neigh *nb)
1772 {
1773 	struct sock *s;
1774 
1775 	write_lock_bh(&x25_list_lock);
1776 
1777 	sk_for_each(s, &x25_list) {
1778 		if (x25_sk(s)->neighbour == nb) {
1779 			write_unlock_bh(&x25_list_lock);
1780 			lock_sock(s);
1781 			x25_disconnect(s, ENETUNREACH, 0, 0);
1782 			release_sock(s);
1783 			write_lock_bh(&x25_list_lock);
1784 		}
1785 	}
1786 	write_unlock_bh(&x25_list_lock);
1787 
1788 	/* Remove any related forwards */
1789 	x25_clear_forward_by_dev(nb->dev);
1790 }
1791 
1792 static int __init x25_init(void)
1793 {
1794 	int rc;
1795 
1796 	rc = proto_register(&x25_proto, 0);
1797 	if (rc)
1798 		goto out;
1799 
1800 	rc = sock_register(&x25_family_ops);
1801 	if (rc)
1802 		goto out_proto;
1803 
1804 	dev_add_pack(&x25_packet_type);
1805 
1806 	rc = register_netdevice_notifier(&x25_dev_notifier);
1807 	if (rc)
1808 		goto out_sock;
1809 
1810 	rc = x25_register_sysctl();
1811 	if (rc)
1812 		goto out_dev;
1813 
1814 	rc = x25_proc_init();
1815 	if (rc)
1816 		goto out_sysctl;
1817 
1818 	pr_info("Linux Version 0.2\n");
1819 
1820 out:
1821 	return rc;
1822 out_sysctl:
1823 	x25_unregister_sysctl();
1824 out_dev:
1825 	unregister_netdevice_notifier(&x25_dev_notifier);
1826 out_sock:
1827 	dev_remove_pack(&x25_packet_type);
1828 	sock_unregister(AF_X25);
1829 out_proto:
1830 	proto_unregister(&x25_proto);
1831 	goto out;
1832 }
1833 module_init(x25_init);
1834 
1835 static void __exit x25_exit(void)
1836 {
1837 	x25_proc_exit();
1838 	x25_link_free();
1839 	x25_route_free();
1840 
1841 	x25_unregister_sysctl();
1842 
1843 	unregister_netdevice_notifier(&x25_dev_notifier);
1844 
1845 	dev_remove_pack(&x25_packet_type);
1846 
1847 	sock_unregister(AF_X25);
1848 	proto_unregister(&x25_proto);
1849 }
1850 module_exit(x25_exit);
1851 
1852 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
1853 MODULE_DESCRIPTION("The X.25 Packet Layer network layer protocol");
1854 MODULE_LICENSE("GPL");
1855 MODULE_ALIAS_NETPROTO(PF_X25);
1856