xref: /linux/net/x25/af_x25.c (revision a4989fa91110508b64eea7ccde63d062113988ff)
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  *	Kill all bound sockets on a dropped device.
204  */
205 static void x25_kill_by_device(struct net_device *dev)
206 {
207 	struct sock *s;
208 
209 	write_lock_bh(&x25_list_lock);
210 
211 	sk_for_each(s, &x25_list)
212 		if (x25_sk(s)->neighbour && x25_sk(s)->neighbour->dev == dev)
213 			x25_disconnect(s, ENETUNREACH, 0, 0);
214 
215 	write_unlock_bh(&x25_list_lock);
216 }
217 
218 /*
219  *	Handle device status changes.
220  */
221 static int x25_device_event(struct notifier_block *this, unsigned long event,
222 			    void *ptr)
223 {
224 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
225 	struct x25_neigh *nb;
226 
227 	if (!net_eq(dev_net(dev), &init_net))
228 		return NOTIFY_DONE;
229 
230 	if (dev->type == ARPHRD_X25
231 #if IS_ENABLED(CONFIG_LLC)
232 	 || dev->type == ARPHRD_ETHER
233 #endif
234 	 ) {
235 		switch (event) {
236 		case NETDEV_REGISTER:
237 		case NETDEV_POST_TYPE_CHANGE:
238 			x25_link_device_up(dev);
239 			break;
240 		case NETDEV_DOWN:
241 			nb = x25_get_neigh(dev);
242 			if (nb) {
243 				x25_link_terminated(nb);
244 				x25_neigh_put(nb);
245 			}
246 			x25_route_device_down(dev);
247 			break;
248 		case NETDEV_PRE_TYPE_CHANGE:
249 		case NETDEV_UNREGISTER:
250 			x25_link_device_down(dev);
251 			break;
252 		case NETDEV_CHANGE:
253 			if (!netif_carrier_ok(dev)) {
254 				nb = x25_get_neigh(dev);
255 				if (nb) {
256 					x25_link_terminated(nb);
257 					x25_neigh_put(nb);
258 				}
259 			}
260 			break;
261 		}
262 	}
263 
264 	return NOTIFY_DONE;
265 }
266 
267 /*
268  *	Add a socket to the bound sockets list.
269  */
270 static void x25_insert_socket(struct sock *sk)
271 {
272 	write_lock_bh(&x25_list_lock);
273 	sk_add_node(sk, &x25_list);
274 	write_unlock_bh(&x25_list_lock);
275 }
276 
277 /*
278  *	Find a socket that wants to accept the Call Request we just
279  *	received. Check the full list for an address/cud match.
280  *	If no cuds match return the next_best thing, an address match.
281  *	Note: if a listening socket has cud set it must only get calls
282  *	with matching cud.
283  */
284 static struct sock *x25_find_listener(struct x25_address *addr,
285 					struct sk_buff *skb)
286 {
287 	struct sock *s;
288 	struct sock *next_best;
289 
290 	read_lock_bh(&x25_list_lock);
291 	next_best = NULL;
292 
293 	sk_for_each(s, &x25_list)
294 		if ((!strcmp(addr->x25_addr,
295 			x25_sk(s)->source_addr.x25_addr) ||
296 				!strcmp(x25_sk(s)->source_addr.x25_addr,
297 					null_x25_address.x25_addr)) &&
298 					s->sk_state == TCP_LISTEN) {
299 			/*
300 			 * Found a listening socket, now check the incoming
301 			 * call user data vs this sockets call user data
302 			 */
303 			if (x25_sk(s)->cudmatchlength > 0 &&
304 				skb->len >= x25_sk(s)->cudmatchlength) {
305 				if((memcmp(x25_sk(s)->calluserdata.cuddata,
306 					skb->data,
307 					x25_sk(s)->cudmatchlength)) == 0) {
308 					sock_hold(s);
309 					goto found;
310 				 }
311 			} else
312 				next_best = s;
313 		}
314 	if (next_best) {
315 		s = next_best;
316 		sock_hold(s);
317 		goto found;
318 	}
319 	s = NULL;
320 found:
321 	read_unlock_bh(&x25_list_lock);
322 	return s;
323 }
324 
325 /*
326  *	Find a connected X.25 socket given my LCI and neighbour.
327  */
328 static struct sock *__x25_find_socket(unsigned int lci, struct x25_neigh *nb)
329 {
330 	struct sock *s;
331 
332 	sk_for_each(s, &x25_list)
333 		if (x25_sk(s)->lci == lci && x25_sk(s)->neighbour == nb) {
334 			sock_hold(s);
335 			goto found;
336 		}
337 	s = NULL;
338 found:
339 	return s;
340 }
341 
342 struct sock *x25_find_socket(unsigned int lci, struct x25_neigh *nb)
343 {
344 	struct sock *s;
345 
346 	read_lock_bh(&x25_list_lock);
347 	s = __x25_find_socket(lci, nb);
348 	read_unlock_bh(&x25_list_lock);
349 	return s;
350 }
351 
352 /*
353  *	Find a unique LCI for a given device.
354  */
355 static unsigned int x25_new_lci(struct x25_neigh *nb)
356 {
357 	unsigned int lci = 1;
358 	struct sock *sk;
359 
360 	while ((sk = x25_find_socket(lci, nb)) != NULL) {
361 		sock_put(sk);
362 		if (++lci == 4096) {
363 			lci = 0;
364 			break;
365 		}
366 		cond_resched();
367 	}
368 
369 	return lci;
370 }
371 
372 /*
373  *	Deferred destroy.
374  */
375 static void __x25_destroy_socket(struct sock *);
376 
377 /*
378  *	handler for deferred kills.
379  */
380 static void x25_destroy_timer(struct timer_list *t)
381 {
382 	struct sock *sk = from_timer(sk, t, sk_timer);
383 
384 	x25_destroy_socket_from_timer(sk);
385 }
386 
387 /*
388  *	This is called from user mode and the timers. Thus it protects itself
389  *	against interrupt users but doesn't worry about being called during
390  *	work. Once it is removed from the queue no interrupt or bottom half
391  *	will touch it and we are (fairly 8-) ) safe.
392  *	Not static as it's used by the timer
393  */
394 static void __x25_destroy_socket(struct sock *sk)
395 {
396 	struct sk_buff *skb;
397 
398 	x25_stop_heartbeat(sk);
399 	x25_stop_timer(sk);
400 
401 	x25_remove_socket(sk);
402 	x25_clear_queues(sk);		/* Flush the queues */
403 
404 	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
405 		if (skb->sk != sk) {		/* A pending connection */
406 			/*
407 			 * Queue the unaccepted socket for death
408 			 */
409 			skb->sk->sk_state = TCP_LISTEN;
410 			sock_set_flag(skb->sk, SOCK_DEAD);
411 			x25_start_heartbeat(skb->sk);
412 			x25_sk(skb->sk)->state = X25_STATE_0;
413 		}
414 
415 		kfree_skb(skb);
416 	}
417 
418 	if (sk_has_allocations(sk)) {
419 		/* Defer: outstanding buffers */
420 		sk->sk_timer.expires  = jiffies + 10 * HZ;
421 		sk->sk_timer.function = x25_destroy_timer;
422 		add_timer(&sk->sk_timer);
423 	} else {
424 		/* drop last reference so sock_put will free */
425 		__sock_put(sk);
426 	}
427 }
428 
429 void x25_destroy_socket_from_timer(struct sock *sk)
430 {
431 	sock_hold(sk);
432 	bh_lock_sock(sk);
433 	__x25_destroy_socket(sk);
434 	bh_unlock_sock(sk);
435 	sock_put(sk);
436 }
437 
438 /*
439  *	Handling for system calls applied via the various interfaces to a
440  *	X.25 socket object.
441  */
442 
443 static int x25_setsockopt(struct socket *sock, int level, int optname,
444 			  sockptr_t optval, unsigned int optlen)
445 {
446 	int opt;
447 	struct sock *sk = sock->sk;
448 	int rc = -ENOPROTOOPT;
449 
450 	if (level != SOL_X25 || optname != X25_QBITINCL)
451 		goto out;
452 
453 	rc = -EINVAL;
454 	if (optlen < sizeof(int))
455 		goto out;
456 
457 	rc = -EFAULT;
458 	if (copy_from_sockptr(&opt, optval, sizeof(int)))
459 		goto out;
460 
461 	if (opt)
462 		set_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
463 	else
464 		clear_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
465 	rc = 0;
466 out:
467 	return rc;
468 }
469 
470 static int x25_getsockopt(struct socket *sock, int level, int optname,
471 			  char __user *optval, int __user *optlen)
472 {
473 	struct sock *sk = sock->sk;
474 	int val, len, rc = -ENOPROTOOPT;
475 
476 	if (level != SOL_X25 || optname != X25_QBITINCL)
477 		goto out;
478 
479 	rc = -EFAULT;
480 	if (get_user(len, optlen))
481 		goto out;
482 
483 	len = min_t(unsigned int, len, sizeof(int));
484 
485 	rc = -EINVAL;
486 	if (len < 0)
487 		goto out;
488 
489 	rc = -EFAULT;
490 	if (put_user(len, optlen))
491 		goto out;
492 
493 	val = test_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
494 	rc = copy_to_user(optval, &val, len) ? -EFAULT : 0;
495 out:
496 	return rc;
497 }
498 
499 static int x25_listen(struct socket *sock, int backlog)
500 {
501 	struct sock *sk = sock->sk;
502 	int rc = -EOPNOTSUPP;
503 
504 	lock_sock(sk);
505 	if (sk->sk_state != TCP_LISTEN) {
506 		memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN);
507 		sk->sk_max_ack_backlog = backlog;
508 		sk->sk_state           = TCP_LISTEN;
509 		rc = 0;
510 	}
511 	release_sock(sk);
512 
513 	return rc;
514 }
515 
516 static struct proto x25_proto = {
517 	.name	  = "X25",
518 	.owner	  = THIS_MODULE,
519 	.obj_size = sizeof(struct x25_sock),
520 };
521 
522 static struct sock *x25_alloc_socket(struct net *net, int kern)
523 {
524 	struct x25_sock *x25;
525 	struct sock *sk = sk_alloc(net, AF_X25, GFP_ATOMIC, &x25_proto, kern);
526 
527 	if (!sk)
528 		goto out;
529 
530 	sock_init_data(NULL, sk);
531 
532 	x25 = x25_sk(sk);
533 	skb_queue_head_init(&x25->ack_queue);
534 	skb_queue_head_init(&x25->fragment_queue);
535 	skb_queue_head_init(&x25->interrupt_in_queue);
536 	skb_queue_head_init(&x25->interrupt_out_queue);
537 out:
538 	return sk;
539 }
540 
541 static int x25_create(struct net *net, struct socket *sock, int protocol,
542 		      int kern)
543 {
544 	struct sock *sk;
545 	struct x25_sock *x25;
546 	int rc = -EAFNOSUPPORT;
547 
548 	if (!net_eq(net, &init_net))
549 		goto out;
550 
551 	rc = -ESOCKTNOSUPPORT;
552 	if (sock->type != SOCK_SEQPACKET)
553 		goto out;
554 
555 	rc = -EINVAL;
556 	if (protocol)
557 		goto out;
558 
559 	rc = -ENOBUFS;
560 	if ((sk = x25_alloc_socket(net, kern)) == NULL)
561 		goto out;
562 
563 	x25 = x25_sk(sk);
564 
565 	sock_init_data(sock, sk);
566 
567 	x25_init_timers(sk);
568 
569 	sock->ops    = &x25_proto_ops;
570 	sk->sk_protocol = protocol;
571 	sk->sk_backlog_rcv = x25_backlog_rcv;
572 
573 	x25->t21   = sysctl_x25_call_request_timeout;
574 	x25->t22   = sysctl_x25_reset_request_timeout;
575 	x25->t23   = sysctl_x25_clear_request_timeout;
576 	x25->t2    = sysctl_x25_ack_holdback_timeout;
577 	x25->state = X25_STATE_0;
578 	x25->cudmatchlength = 0;
579 	set_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);	/* normally no cud  */
580 							/* on call accept   */
581 
582 	x25->facilities.winsize_in  = X25_DEFAULT_WINDOW_SIZE;
583 	x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
584 	x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
585 	x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
586 	x25->facilities.throughput  = 0;	/* by default don't negotiate
587 						   throughput */
588 	x25->facilities.reverse     = X25_DEFAULT_REVERSE;
589 	x25->dte_facilities.calling_len = 0;
590 	x25->dte_facilities.called_len = 0;
591 	memset(x25->dte_facilities.called_ae, '\0',
592 			sizeof(x25->dte_facilities.called_ae));
593 	memset(x25->dte_facilities.calling_ae, '\0',
594 			sizeof(x25->dte_facilities.calling_ae));
595 
596 	rc = 0;
597 out:
598 	return rc;
599 }
600 
601 static struct sock *x25_make_new(struct sock *osk)
602 {
603 	struct sock *sk = NULL;
604 	struct x25_sock *x25, *ox25;
605 
606 	if (osk->sk_type != SOCK_SEQPACKET)
607 		goto out;
608 
609 	if ((sk = x25_alloc_socket(sock_net(osk), 0)) == NULL)
610 		goto out;
611 
612 	x25 = x25_sk(sk);
613 
614 	sk->sk_type        = osk->sk_type;
615 	sk->sk_priority    = osk->sk_priority;
616 	sk->sk_protocol    = osk->sk_protocol;
617 	sk->sk_rcvbuf      = osk->sk_rcvbuf;
618 	sk->sk_sndbuf      = osk->sk_sndbuf;
619 	sk->sk_state       = TCP_ESTABLISHED;
620 	sk->sk_backlog_rcv = osk->sk_backlog_rcv;
621 	sock_copy_flags(sk, osk);
622 
623 	ox25 = x25_sk(osk);
624 	x25->t21        = ox25->t21;
625 	x25->t22        = ox25->t22;
626 	x25->t23        = ox25->t23;
627 	x25->t2         = ox25->t2;
628 	x25->flags	= ox25->flags;
629 	x25->facilities = ox25->facilities;
630 	x25->dte_facilities = ox25->dte_facilities;
631 	x25->cudmatchlength = ox25->cudmatchlength;
632 
633 	clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
634 	x25_init_timers(sk);
635 out:
636 	return sk;
637 }
638 
639 static int x25_release(struct socket *sock)
640 {
641 	struct sock *sk = sock->sk;
642 	struct x25_sock *x25;
643 
644 	if (!sk)
645 		return 0;
646 
647 	x25 = x25_sk(sk);
648 
649 	sock_hold(sk);
650 	lock_sock(sk);
651 	switch (x25->state) {
652 
653 		case X25_STATE_0:
654 		case X25_STATE_2:
655 			x25_disconnect(sk, 0, 0, 0);
656 			__x25_destroy_socket(sk);
657 			goto out;
658 
659 		case X25_STATE_1:
660 		case X25_STATE_3:
661 		case X25_STATE_4:
662 			x25_clear_queues(sk);
663 			x25_write_internal(sk, X25_CLEAR_REQUEST);
664 			x25_start_t23timer(sk);
665 			x25->state = X25_STATE_2;
666 			sk->sk_state	= TCP_CLOSE;
667 			sk->sk_shutdown	|= SEND_SHUTDOWN;
668 			sk->sk_state_change(sk);
669 			sock_set_flag(sk, SOCK_DEAD);
670 			sock_set_flag(sk, SOCK_DESTROY);
671 			break;
672 
673 		case X25_STATE_5:
674 			x25_write_internal(sk, X25_CLEAR_REQUEST);
675 			x25_disconnect(sk, 0, 0, 0);
676 			__x25_destroy_socket(sk);
677 			goto out;
678 	}
679 
680 	sock_orphan(sk);
681 out:
682 	release_sock(sk);
683 	sock_put(sk);
684 	return 0;
685 }
686 
687 static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
688 {
689 	struct sock *sk = sock->sk;
690 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
691 	int len, i, rc = 0;
692 
693 	if (addr_len != sizeof(struct sockaddr_x25) ||
694 	    addr->sx25_family != AF_X25) {
695 		rc = -EINVAL;
696 		goto out;
697 	}
698 
699 	/* check for the null_x25_address */
700 	if (strcmp(addr->sx25_addr.x25_addr, null_x25_address.x25_addr)) {
701 
702 		len = strlen(addr->sx25_addr.x25_addr);
703 		for (i = 0; i < len; i++) {
704 			if (!isdigit(addr->sx25_addr.x25_addr[i])) {
705 				rc = -EINVAL;
706 				goto out;
707 			}
708 		}
709 	}
710 
711 	lock_sock(sk);
712 	if (sock_flag(sk, SOCK_ZAPPED)) {
713 		x25_sk(sk)->source_addr = addr->sx25_addr;
714 		x25_insert_socket(sk);
715 		sock_reset_flag(sk, SOCK_ZAPPED);
716 	} else {
717 		rc = -EINVAL;
718 	}
719 	release_sock(sk);
720 	SOCK_DEBUG(sk, "x25_bind: socket is bound\n");
721 out:
722 	return rc;
723 }
724 
725 static int x25_wait_for_connection_establishment(struct sock *sk)
726 {
727 	DECLARE_WAITQUEUE(wait, current);
728 	int rc;
729 
730 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
731 	for (;;) {
732 		__set_current_state(TASK_INTERRUPTIBLE);
733 		rc = -ERESTARTSYS;
734 		if (signal_pending(current))
735 			break;
736 		rc = sock_error(sk);
737 		if (rc) {
738 			sk->sk_socket->state = SS_UNCONNECTED;
739 			break;
740 		}
741 		rc = 0;
742 		if (sk->sk_state != TCP_ESTABLISHED) {
743 			release_sock(sk);
744 			schedule();
745 			lock_sock(sk);
746 		} else
747 			break;
748 	}
749 	__set_current_state(TASK_RUNNING);
750 	remove_wait_queue(sk_sleep(sk), &wait);
751 	return rc;
752 }
753 
754 static int x25_connect(struct socket *sock, struct sockaddr *uaddr,
755 		       int addr_len, int flags)
756 {
757 	struct sock *sk = sock->sk;
758 	struct x25_sock *x25 = x25_sk(sk);
759 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
760 	struct x25_route *rt;
761 	int rc = 0;
762 
763 	lock_sock(sk);
764 	if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
765 		sock->state = SS_CONNECTED;
766 		goto out; /* Connect completed during a ERESTARTSYS event */
767 	}
768 
769 	rc = -ECONNREFUSED;
770 	if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
771 		sock->state = SS_UNCONNECTED;
772 		goto out;
773 	}
774 
775 	rc = -EISCONN;	/* No reconnect on a seqpacket socket */
776 	if (sk->sk_state == TCP_ESTABLISHED)
777 		goto out;
778 
779 	rc = -EALREADY;	/* Do nothing if call is already in progress */
780 	if (sk->sk_state == TCP_SYN_SENT)
781 		goto out;
782 
783 	sk->sk_state   = TCP_CLOSE;
784 	sock->state = SS_UNCONNECTED;
785 
786 	rc = -EINVAL;
787 	if (addr_len != sizeof(struct sockaddr_x25) ||
788 	    addr->sx25_family != AF_X25)
789 		goto out;
790 
791 	rc = -ENETUNREACH;
792 	rt = x25_get_route(&addr->sx25_addr);
793 	if (!rt)
794 		goto out;
795 
796 	x25->neighbour = x25_get_neigh(rt->dev);
797 	if (!x25->neighbour)
798 		goto out_put_route;
799 
800 	x25_limit_facilities(&x25->facilities, x25->neighbour);
801 
802 	x25->lci = x25_new_lci(x25->neighbour);
803 	if (!x25->lci)
804 		goto out_put_neigh;
805 
806 	rc = -EINVAL;
807 	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
808 		goto out_put_neigh;
809 
810 	if (!strcmp(x25->source_addr.x25_addr, null_x25_address.x25_addr))
811 		memset(&x25->source_addr, '\0', X25_ADDR_LEN);
812 
813 	x25->dest_addr = addr->sx25_addr;
814 
815 	/* Move to connecting socket, start sending Connect Requests */
816 	sock->state   = SS_CONNECTING;
817 	sk->sk_state  = TCP_SYN_SENT;
818 
819 	x25->state = X25_STATE_1;
820 
821 	x25_write_internal(sk, X25_CALL_REQUEST);
822 
823 	x25_start_heartbeat(sk);
824 	x25_start_t21timer(sk);
825 
826 	/* Now the loop */
827 	rc = -EINPROGRESS;
828 	if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK))
829 		goto out;
830 
831 	rc = x25_wait_for_connection_establishment(sk);
832 	if (rc)
833 		goto out_put_neigh;
834 
835 	sock->state = SS_CONNECTED;
836 	rc = 0;
837 out_put_neigh:
838 	if (rc && x25->neighbour) {
839 		read_lock_bh(&x25_list_lock);
840 		x25_neigh_put(x25->neighbour);
841 		x25->neighbour = NULL;
842 		read_unlock_bh(&x25_list_lock);
843 		x25->state = X25_STATE_0;
844 	}
845 out_put_route:
846 	x25_route_put(rt);
847 out:
848 	release_sock(sk);
849 	return rc;
850 }
851 
852 static int x25_wait_for_data(struct sock *sk, long timeout)
853 {
854 	DECLARE_WAITQUEUE(wait, current);
855 	int rc = 0;
856 
857 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
858 	for (;;) {
859 		__set_current_state(TASK_INTERRUPTIBLE);
860 		if (sk->sk_shutdown & RCV_SHUTDOWN)
861 			break;
862 		rc = -ERESTARTSYS;
863 		if (signal_pending(current))
864 			break;
865 		rc = -EAGAIN;
866 		if (!timeout)
867 			break;
868 		rc = 0;
869 		if (skb_queue_empty(&sk->sk_receive_queue)) {
870 			release_sock(sk);
871 			timeout = schedule_timeout(timeout);
872 			lock_sock(sk);
873 		} else
874 			break;
875 	}
876 	__set_current_state(TASK_RUNNING);
877 	remove_wait_queue(sk_sleep(sk), &wait);
878 	return rc;
879 }
880 
881 static int x25_accept(struct socket *sock, struct socket *newsock, int flags,
882 		      bool kern)
883 {
884 	struct sock *sk = sock->sk;
885 	struct sock *newsk;
886 	struct sk_buff *skb;
887 	int rc = -EINVAL;
888 
889 	if (!sk)
890 		goto out;
891 
892 	rc = -EOPNOTSUPP;
893 	if (sk->sk_type != SOCK_SEQPACKET)
894 		goto out;
895 
896 	lock_sock(sk);
897 	rc = -EINVAL;
898 	if (sk->sk_state != TCP_LISTEN)
899 		goto out2;
900 
901 	rc = x25_wait_for_data(sk, sk->sk_rcvtimeo);
902 	if (rc)
903 		goto out2;
904 	skb = skb_dequeue(&sk->sk_receive_queue);
905 	rc = -EINVAL;
906 	if (!skb->sk)
907 		goto out2;
908 	newsk		 = skb->sk;
909 	sock_graft(newsk, newsock);
910 
911 	/* Now attach up the new socket */
912 	skb->sk = NULL;
913 	kfree_skb(skb);
914 	sk_acceptq_removed(sk);
915 	newsock->state = SS_CONNECTED;
916 	rc = 0;
917 out2:
918 	release_sock(sk);
919 out:
920 	return rc;
921 }
922 
923 static int x25_getname(struct socket *sock, struct sockaddr *uaddr,
924 		       int peer)
925 {
926 	struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)uaddr;
927 	struct sock *sk = sock->sk;
928 	struct x25_sock *x25 = x25_sk(sk);
929 	int rc = 0;
930 
931 	if (peer) {
932 		if (sk->sk_state != TCP_ESTABLISHED) {
933 			rc = -ENOTCONN;
934 			goto out;
935 		}
936 		sx25->sx25_addr = x25->dest_addr;
937 	} else
938 		sx25->sx25_addr = x25->source_addr;
939 
940 	sx25->sx25_family = AF_X25;
941 	rc = sizeof(*sx25);
942 
943 out:
944 	return rc;
945 }
946 
947 int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
948 			unsigned int lci)
949 {
950 	struct sock *sk;
951 	struct sock *make;
952 	struct x25_sock *makex25;
953 	struct x25_address source_addr, dest_addr;
954 	struct x25_facilities facilities;
955 	struct x25_dte_facilities dte_facilities;
956 	int len, addr_len, rc;
957 
958 	/*
959 	 *	Remove the LCI and frame type.
960 	 */
961 	skb_pull(skb, X25_STD_MIN_LEN);
962 
963 	/*
964 	 *	Extract the X.25 addresses and convert them to ASCII strings,
965 	 *	and remove them.
966 	 *
967 	 *	Address block is mandatory in call request packets
968 	 */
969 	addr_len = x25_parse_address_block(skb, &source_addr, &dest_addr);
970 	if (addr_len <= 0)
971 		goto out_clear_request;
972 	skb_pull(skb, addr_len);
973 
974 	/*
975 	 *	Get the length of the facilities, skip past them for the moment
976 	 *	get the call user data because this is needed to determine
977 	 *	the correct listener
978 	 *
979 	 *	Facilities length is mandatory in call request packets
980 	 */
981 	if (!pskb_may_pull(skb, 1))
982 		goto out_clear_request;
983 	len = skb->data[0] + 1;
984 	if (!pskb_may_pull(skb, len))
985 		goto out_clear_request;
986 	skb_pull(skb,len);
987 
988 	/*
989 	 *	Ensure that the amount of call user data is valid.
990 	 */
991 	if (skb->len > X25_MAX_CUD_LEN)
992 		goto out_clear_request;
993 
994 	/*
995 	 *	Get all the call user data so it can be used in
996 	 *	x25_find_listener and skb_copy_from_linear_data up ahead.
997 	 */
998 	if (!pskb_may_pull(skb, skb->len))
999 		goto out_clear_request;
1000 
1001 	/*
1002 	 *	Find a listener for the particular address/cud pair.
1003 	 */
1004 	sk = x25_find_listener(&source_addr,skb);
1005 	skb_push(skb,len);
1006 
1007 	if (sk != NULL && sk_acceptq_is_full(sk)) {
1008 		goto out_sock_put;
1009 	}
1010 
1011 	/*
1012 	 *	We dont have any listeners for this incoming call.
1013 	 *	Try forwarding it.
1014 	 */
1015 	if (sk == NULL) {
1016 		skb_push(skb, addr_len + X25_STD_MIN_LEN);
1017 		if (sysctl_x25_forward &&
1018 				x25_forward_call(&dest_addr, nb, skb, lci) > 0)
1019 		{
1020 			/* Call was forwarded, dont process it any more */
1021 			kfree_skb(skb);
1022 			rc = 1;
1023 			goto out;
1024 		} else {
1025 			/* No listeners, can't forward, clear the call */
1026 			goto out_clear_request;
1027 		}
1028 	}
1029 
1030 	/*
1031 	 *	Try to reach a compromise on the requested facilities.
1032 	 */
1033 	len = x25_negotiate_facilities(skb, sk, &facilities, &dte_facilities);
1034 	if (len == -1)
1035 		goto out_sock_put;
1036 
1037 	/*
1038 	 * current neighbour/link might impose additional limits
1039 	 * on certain facilties
1040 	 */
1041 
1042 	x25_limit_facilities(&facilities, nb);
1043 
1044 	/*
1045 	 *	Try to create a new socket.
1046 	 */
1047 	make = x25_make_new(sk);
1048 	if (!make)
1049 		goto out_sock_put;
1050 
1051 	/*
1052 	 *	Remove the facilities
1053 	 */
1054 	skb_pull(skb, len);
1055 
1056 	skb->sk     = make;
1057 	make->sk_state = TCP_ESTABLISHED;
1058 
1059 	makex25 = x25_sk(make);
1060 	makex25->lci           = lci;
1061 	makex25->dest_addr     = dest_addr;
1062 	makex25->source_addr   = source_addr;
1063 	x25_neigh_hold(nb);
1064 	makex25->neighbour     = nb;
1065 	makex25->facilities    = facilities;
1066 	makex25->dte_facilities= dte_facilities;
1067 	makex25->vc_facil_mask = x25_sk(sk)->vc_facil_mask;
1068 	/* ensure no reverse facil on accept */
1069 	makex25->vc_facil_mask &= ~X25_MASK_REVERSE;
1070 	/* ensure no calling address extension on accept */
1071 	makex25->vc_facil_mask &= ~X25_MASK_CALLING_AE;
1072 	makex25->cudmatchlength = x25_sk(sk)->cudmatchlength;
1073 
1074 	/* Normally all calls are accepted immediately */
1075 	if (test_bit(X25_ACCPT_APPRV_FLAG, &makex25->flags)) {
1076 		x25_write_internal(make, X25_CALL_ACCEPTED);
1077 		makex25->state = X25_STATE_3;
1078 	} else {
1079 		makex25->state = X25_STATE_5;
1080 	}
1081 
1082 	/*
1083 	 *	Incoming Call User Data.
1084 	 */
1085 	skb_copy_from_linear_data(skb, makex25->calluserdata.cuddata, skb->len);
1086 	makex25->calluserdata.cudlength = skb->len;
1087 
1088 	sk_acceptq_added(sk);
1089 
1090 	x25_insert_socket(make);
1091 
1092 	skb_queue_head(&sk->sk_receive_queue, skb);
1093 
1094 	x25_start_heartbeat(make);
1095 
1096 	if (!sock_flag(sk, SOCK_DEAD))
1097 		sk->sk_data_ready(sk);
1098 	rc = 1;
1099 	sock_put(sk);
1100 out:
1101 	return rc;
1102 out_sock_put:
1103 	sock_put(sk);
1104 out_clear_request:
1105 	rc = 0;
1106 	x25_transmit_clear_request(nb, lci, 0x01);
1107 	goto out;
1108 }
1109 
1110 static int x25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1111 {
1112 	struct sock *sk = sock->sk;
1113 	struct x25_sock *x25 = x25_sk(sk);
1114 	DECLARE_SOCKADDR(struct sockaddr_x25 *, usx25, msg->msg_name);
1115 	struct sockaddr_x25 sx25;
1116 	struct sk_buff *skb;
1117 	unsigned char *asmptr;
1118 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1119 	size_t size;
1120 	int qbit = 0, rc = -EINVAL;
1121 
1122 	lock_sock(sk);
1123 	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_OOB|MSG_EOR|MSG_CMSG_COMPAT))
1124 		goto out;
1125 
1126 	/* we currently don't support segmented records at the user interface */
1127 	if (!(msg->msg_flags & (MSG_EOR|MSG_OOB)))
1128 		goto out;
1129 
1130 	rc = -EADDRNOTAVAIL;
1131 	if (sock_flag(sk, SOCK_ZAPPED))
1132 		goto out;
1133 
1134 	rc = -EPIPE;
1135 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1136 		send_sig(SIGPIPE, current, 0);
1137 		goto out;
1138 	}
1139 
1140 	rc = -ENETUNREACH;
1141 	if (!x25->neighbour)
1142 		goto out;
1143 
1144 	if (usx25) {
1145 		rc = -EINVAL;
1146 		if (msg->msg_namelen < sizeof(sx25))
1147 			goto out;
1148 		memcpy(&sx25, usx25, sizeof(sx25));
1149 		rc = -EISCONN;
1150 		if (strcmp(x25->dest_addr.x25_addr, sx25.sx25_addr.x25_addr))
1151 			goto out;
1152 		rc = -EINVAL;
1153 		if (sx25.sx25_family != AF_X25)
1154 			goto out;
1155 	} else {
1156 		/*
1157 		 *	FIXME 1003.1g - if the socket is like this because
1158 		 *	it has become closed (not started closed) we ought
1159 		 *	to SIGPIPE, EPIPE;
1160 		 */
1161 		rc = -ENOTCONN;
1162 		if (sk->sk_state != TCP_ESTABLISHED)
1163 			goto out;
1164 
1165 		sx25.sx25_family = AF_X25;
1166 		sx25.sx25_addr   = x25->dest_addr;
1167 	}
1168 
1169 	/* Sanity check the packet size */
1170 	if (len > 65535) {
1171 		rc = -EMSGSIZE;
1172 		goto out;
1173 	}
1174 
1175 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: Addresses built.\n");
1176 
1177 	/* Build a packet */
1178 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: building packet.\n");
1179 
1180 	if ((msg->msg_flags & MSG_OOB) && len > 32)
1181 		len = 32;
1182 
1183 	size = len + X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
1184 
1185 	release_sock(sk);
1186 	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
1187 	lock_sock(sk);
1188 	if (!skb)
1189 		goto out;
1190 	X25_SKB_CB(skb)->flags = msg->msg_flags;
1191 
1192 	skb_reserve(skb, X25_MAX_L2_LEN + X25_EXT_MIN_LEN);
1193 
1194 	/*
1195 	 *	Put the data on the end
1196 	 */
1197 	SOCK_DEBUG(sk, "x25_sendmsg: Copying user data\n");
1198 
1199 	skb_reset_transport_header(skb);
1200 	skb_put(skb, len);
1201 
1202 	rc = memcpy_from_msg(skb_transport_header(skb), msg, len);
1203 	if (rc)
1204 		goto out_kfree_skb;
1205 
1206 	/*
1207 	 *	If the Q BIT Include socket option is in force, the first
1208 	 *	byte of the user data is the logical value of the Q Bit.
1209 	 */
1210 	if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1211 		if (!pskb_may_pull(skb, 1))
1212 			goto out_kfree_skb;
1213 
1214 		qbit = skb->data[0];
1215 		skb_pull(skb, 1);
1216 	}
1217 
1218 	/*
1219 	 *	Push down the X.25 header
1220 	 */
1221 	SOCK_DEBUG(sk, "x25_sendmsg: Building X.25 Header.\n");
1222 
1223 	if (msg->msg_flags & MSG_OOB) {
1224 		if (x25->neighbour->extended) {
1225 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1226 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1227 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1228 			*asmptr++ = X25_INTERRUPT;
1229 		} else {
1230 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1231 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1232 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1233 			*asmptr++ = X25_INTERRUPT;
1234 		}
1235 	} else {
1236 		if (x25->neighbour->extended) {
1237 			/* Build an Extended X.25 header */
1238 			asmptr    = skb_push(skb, X25_EXT_MIN_LEN);
1239 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1240 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1241 			*asmptr++ = X25_DATA;
1242 			*asmptr++ = X25_DATA;
1243 		} else {
1244 			/* Build an Standard X.25 header */
1245 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1246 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1247 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1248 			*asmptr++ = X25_DATA;
1249 		}
1250 
1251 		if (qbit)
1252 			skb->data[0] |= X25_Q_BIT;
1253 	}
1254 
1255 	SOCK_DEBUG(sk, "x25_sendmsg: Built header.\n");
1256 	SOCK_DEBUG(sk, "x25_sendmsg: Transmitting buffer\n");
1257 
1258 	rc = -ENOTCONN;
1259 	if (sk->sk_state != TCP_ESTABLISHED)
1260 		goto out_kfree_skb;
1261 
1262 	if (msg->msg_flags & MSG_OOB)
1263 		skb_queue_tail(&x25->interrupt_out_queue, skb);
1264 	else {
1265 		rc = x25_output(sk, skb);
1266 		len = rc;
1267 		if (rc < 0)
1268 			kfree_skb(skb);
1269 		else if (test_bit(X25_Q_BIT_FLAG, &x25->flags))
1270 			len++;
1271 	}
1272 
1273 	x25_kick(sk);
1274 	rc = len;
1275 out:
1276 	release_sock(sk);
1277 	return rc;
1278 out_kfree_skb:
1279 	kfree_skb(skb);
1280 	goto out;
1281 }
1282 
1283 
1284 static int x25_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1285 		       int flags)
1286 {
1287 	struct sock *sk = sock->sk;
1288 	struct x25_sock *x25 = x25_sk(sk);
1289 	DECLARE_SOCKADDR(struct sockaddr_x25 *, sx25, msg->msg_name);
1290 	size_t copied;
1291 	int qbit, header_len;
1292 	struct sk_buff *skb;
1293 	unsigned char *asmptr;
1294 	int rc = -ENOTCONN;
1295 
1296 	lock_sock(sk);
1297 
1298 	if (x25->neighbour == NULL)
1299 		goto out;
1300 
1301 	header_len = x25->neighbour->extended ?
1302 		X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
1303 
1304 	/*
1305 	 * This works for seqpacket too. The receiver has ordered the queue for
1306 	 * us! We do one quick check first though
1307 	 */
1308 	if (sk->sk_state != TCP_ESTABLISHED)
1309 		goto out;
1310 
1311 	if (flags & MSG_OOB) {
1312 		rc = -EINVAL;
1313 		if (sock_flag(sk, SOCK_URGINLINE) ||
1314 		    !skb_peek(&x25->interrupt_in_queue))
1315 			goto out;
1316 
1317 		skb = skb_dequeue(&x25->interrupt_in_queue);
1318 
1319 		if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
1320 			goto out_free_dgram;
1321 
1322 		skb_pull(skb, X25_STD_MIN_LEN);
1323 
1324 		/*
1325 		 *	No Q bit information on Interrupt data.
1326 		 */
1327 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1328 			asmptr  = skb_push(skb, 1);
1329 			*asmptr = 0x00;
1330 		}
1331 
1332 		msg->msg_flags |= MSG_OOB;
1333 	} else {
1334 		/* Now we can treat all alike */
1335 		release_sock(sk);
1336 		skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1337 					flags & MSG_DONTWAIT, &rc);
1338 		lock_sock(sk);
1339 		if (!skb)
1340 			goto out;
1341 
1342 		if (!pskb_may_pull(skb, header_len))
1343 			goto out_free_dgram;
1344 
1345 		qbit = (skb->data[0] & X25_Q_BIT) == X25_Q_BIT;
1346 
1347 		skb_pull(skb, header_len);
1348 
1349 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1350 			asmptr  = skb_push(skb, 1);
1351 			*asmptr = qbit;
1352 		}
1353 	}
1354 
1355 	skb_reset_transport_header(skb);
1356 	copied = skb->len;
1357 
1358 	if (copied > size) {
1359 		copied = size;
1360 		msg->msg_flags |= MSG_TRUNC;
1361 	}
1362 
1363 	/* Currently, each datagram always contains a complete record */
1364 	msg->msg_flags |= MSG_EOR;
1365 
1366 	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
1367 	if (rc)
1368 		goto out_free_dgram;
1369 
1370 	if (sx25) {
1371 		sx25->sx25_family = AF_X25;
1372 		sx25->sx25_addr   = x25->dest_addr;
1373 		msg->msg_namelen = sizeof(*sx25);
1374 	}
1375 
1376 	x25_check_rbuf(sk);
1377 	rc = copied;
1378 out_free_dgram:
1379 	skb_free_datagram(sk, skb);
1380 out:
1381 	release_sock(sk);
1382 	return rc;
1383 }
1384 
1385 
1386 static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1387 {
1388 	struct sock *sk = sock->sk;
1389 	struct x25_sock *x25 = x25_sk(sk);
1390 	void __user *argp = (void __user *)arg;
1391 	int rc;
1392 
1393 	switch (cmd) {
1394 	case TIOCOUTQ: {
1395 		int amount;
1396 
1397 		amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1398 		if (amount < 0)
1399 			amount = 0;
1400 		rc = put_user(amount, (unsigned int __user *)argp);
1401 		break;
1402 	}
1403 
1404 	case TIOCINQ: {
1405 		struct sk_buff *skb;
1406 		int amount = 0;
1407 		/*
1408 		 * These two are safe on a single CPU system as
1409 		 * only user tasks fiddle here
1410 		 */
1411 		lock_sock(sk);
1412 		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1413 			amount = skb->len;
1414 		release_sock(sk);
1415 		rc = put_user(amount, (unsigned int __user *)argp);
1416 		break;
1417 	}
1418 
1419 	case SIOCGIFADDR:
1420 	case SIOCSIFADDR:
1421 	case SIOCGIFDSTADDR:
1422 	case SIOCSIFDSTADDR:
1423 	case SIOCGIFBRDADDR:
1424 	case SIOCSIFBRDADDR:
1425 	case SIOCGIFNETMASK:
1426 	case SIOCSIFNETMASK:
1427 	case SIOCGIFMETRIC:
1428 	case SIOCSIFMETRIC:
1429 		rc = -EINVAL;
1430 		break;
1431 	case SIOCADDRT:
1432 	case SIOCDELRT:
1433 		rc = -EPERM;
1434 		if (!capable(CAP_NET_ADMIN))
1435 			break;
1436 		rc = x25_route_ioctl(cmd, argp);
1437 		break;
1438 	case SIOCX25GSUBSCRIP:
1439 		rc = x25_subscr_ioctl(cmd, argp);
1440 		break;
1441 	case SIOCX25SSUBSCRIP:
1442 		rc = -EPERM;
1443 		if (!capable(CAP_NET_ADMIN))
1444 			break;
1445 		rc = x25_subscr_ioctl(cmd, argp);
1446 		break;
1447 	case SIOCX25GFACILITIES: {
1448 		lock_sock(sk);
1449 		rc = copy_to_user(argp, &x25->facilities,
1450 				  sizeof(x25->facilities))
1451 			? -EFAULT : 0;
1452 		release_sock(sk);
1453 		break;
1454 	}
1455 
1456 	case SIOCX25SFACILITIES: {
1457 		struct x25_facilities facilities;
1458 		rc = -EFAULT;
1459 		if (copy_from_user(&facilities, argp, sizeof(facilities)))
1460 			break;
1461 		rc = -EINVAL;
1462 		lock_sock(sk);
1463 		if (sk->sk_state != TCP_LISTEN &&
1464 		    sk->sk_state != TCP_CLOSE)
1465 			goto out_fac_release;
1466 		if (facilities.pacsize_in < X25_PS16 ||
1467 		    facilities.pacsize_in > X25_PS4096)
1468 			goto out_fac_release;
1469 		if (facilities.pacsize_out < X25_PS16 ||
1470 		    facilities.pacsize_out > X25_PS4096)
1471 			goto out_fac_release;
1472 		if (facilities.winsize_in < 1 ||
1473 		    facilities.winsize_in > 127)
1474 			goto out_fac_release;
1475 		if (facilities.throughput) {
1476 			int out = facilities.throughput & 0xf0;
1477 			int in  = facilities.throughput & 0x0f;
1478 			if (!out)
1479 				facilities.throughput |=
1480 					X25_DEFAULT_THROUGHPUT << 4;
1481 			else if (out < 0x30 || out > 0xD0)
1482 				goto out_fac_release;
1483 			if (!in)
1484 				facilities.throughput |=
1485 					X25_DEFAULT_THROUGHPUT;
1486 			else if (in < 0x03 || in > 0x0D)
1487 				goto out_fac_release;
1488 		}
1489 		if (facilities.reverse &&
1490 		    (facilities.reverse & 0x81) != 0x81)
1491 			goto out_fac_release;
1492 		x25->facilities = facilities;
1493 		rc = 0;
1494 out_fac_release:
1495 		release_sock(sk);
1496 		break;
1497 	}
1498 
1499 	case SIOCX25GDTEFACILITIES: {
1500 		lock_sock(sk);
1501 		rc = copy_to_user(argp, &x25->dte_facilities,
1502 				  sizeof(x25->dte_facilities));
1503 		release_sock(sk);
1504 		if (rc)
1505 			rc = -EFAULT;
1506 		break;
1507 	}
1508 
1509 	case SIOCX25SDTEFACILITIES: {
1510 		struct x25_dte_facilities dtefacs;
1511 		rc = -EFAULT;
1512 		if (copy_from_user(&dtefacs, argp, sizeof(dtefacs)))
1513 			break;
1514 		rc = -EINVAL;
1515 		lock_sock(sk);
1516 		if (sk->sk_state != TCP_LISTEN &&
1517 		    sk->sk_state != TCP_CLOSE)
1518 			goto out_dtefac_release;
1519 		if (dtefacs.calling_len > X25_MAX_AE_LEN)
1520 			goto out_dtefac_release;
1521 		if (dtefacs.called_len > X25_MAX_AE_LEN)
1522 			goto out_dtefac_release;
1523 		x25->dte_facilities = dtefacs;
1524 		rc = 0;
1525 out_dtefac_release:
1526 		release_sock(sk);
1527 		break;
1528 	}
1529 
1530 	case SIOCX25GCALLUSERDATA: {
1531 		lock_sock(sk);
1532 		rc = copy_to_user(argp, &x25->calluserdata,
1533 				  sizeof(x25->calluserdata))
1534 			? -EFAULT : 0;
1535 		release_sock(sk);
1536 		break;
1537 	}
1538 
1539 	case SIOCX25SCALLUSERDATA: {
1540 		struct x25_calluserdata calluserdata;
1541 
1542 		rc = -EFAULT;
1543 		if (copy_from_user(&calluserdata, argp, sizeof(calluserdata)))
1544 			break;
1545 		rc = -EINVAL;
1546 		if (calluserdata.cudlength > X25_MAX_CUD_LEN)
1547 			break;
1548 		lock_sock(sk);
1549 		x25->calluserdata = calluserdata;
1550 		release_sock(sk);
1551 		rc = 0;
1552 		break;
1553 	}
1554 
1555 	case SIOCX25GCAUSEDIAG: {
1556 		lock_sock(sk);
1557 		rc = copy_to_user(argp, &x25->causediag, sizeof(x25->causediag))
1558 			? -EFAULT : 0;
1559 		release_sock(sk);
1560 		break;
1561 	}
1562 
1563 	case SIOCX25SCAUSEDIAG: {
1564 		struct x25_causediag causediag;
1565 		rc = -EFAULT;
1566 		if (copy_from_user(&causediag, argp, sizeof(causediag)))
1567 			break;
1568 		lock_sock(sk);
1569 		x25->causediag = causediag;
1570 		release_sock(sk);
1571 		rc = 0;
1572 		break;
1573 
1574 	}
1575 
1576 	case SIOCX25SCUDMATCHLEN: {
1577 		struct x25_subaddr sub_addr;
1578 		rc = -EINVAL;
1579 		lock_sock(sk);
1580 		if(sk->sk_state != TCP_CLOSE)
1581 			goto out_cud_release;
1582 		rc = -EFAULT;
1583 		if (copy_from_user(&sub_addr, argp,
1584 				   sizeof(sub_addr)))
1585 			goto out_cud_release;
1586 		rc = -EINVAL;
1587 		if (sub_addr.cudmatchlength > X25_MAX_CUD_LEN)
1588 			goto out_cud_release;
1589 		x25->cudmatchlength = sub_addr.cudmatchlength;
1590 		rc = 0;
1591 out_cud_release:
1592 		release_sock(sk);
1593 		break;
1594 	}
1595 
1596 	case SIOCX25CALLACCPTAPPRV: {
1597 		rc = -EINVAL;
1598 		lock_sock(sk);
1599 		if (sk->sk_state == TCP_CLOSE) {
1600 			clear_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);
1601 			rc = 0;
1602 		}
1603 		release_sock(sk);
1604 		break;
1605 	}
1606 
1607 	case SIOCX25SENDCALLACCPT:  {
1608 		rc = -EINVAL;
1609 		lock_sock(sk);
1610 		if (sk->sk_state != TCP_ESTABLISHED)
1611 			goto out_sendcallaccpt_release;
1612 		/* must call accptapprv above */
1613 		if (test_bit(X25_ACCPT_APPRV_FLAG, &x25->flags))
1614 			goto out_sendcallaccpt_release;
1615 		x25_write_internal(sk, X25_CALL_ACCEPTED);
1616 		x25->state = X25_STATE_3;
1617 		rc = 0;
1618 out_sendcallaccpt_release:
1619 		release_sock(sk);
1620 		break;
1621 	}
1622 
1623 	default:
1624 		rc = -ENOIOCTLCMD;
1625 		break;
1626 	}
1627 
1628 	return rc;
1629 }
1630 
1631 static const struct net_proto_family x25_family_ops = {
1632 	.family =	AF_X25,
1633 	.create =	x25_create,
1634 	.owner	=	THIS_MODULE,
1635 };
1636 
1637 #ifdef CONFIG_COMPAT
1638 static int compat_x25_subscr_ioctl(unsigned int cmd,
1639 		struct compat_x25_subscrip_struct __user *x25_subscr32)
1640 {
1641 	struct compat_x25_subscrip_struct x25_subscr;
1642 	struct x25_neigh *nb;
1643 	struct net_device *dev;
1644 	int rc = -EINVAL;
1645 
1646 	rc = -EFAULT;
1647 	if (copy_from_user(&x25_subscr, x25_subscr32, sizeof(*x25_subscr32)))
1648 		goto out;
1649 
1650 	rc = -EINVAL;
1651 	dev = x25_dev_get(x25_subscr.device);
1652 	if (dev == NULL)
1653 		goto out;
1654 
1655 	nb = x25_get_neigh(dev);
1656 	if (nb == NULL)
1657 		goto out_dev_put;
1658 
1659 	dev_put(dev);
1660 
1661 	if (cmd == SIOCX25GSUBSCRIP) {
1662 		read_lock_bh(&x25_neigh_list_lock);
1663 		x25_subscr.extended = nb->extended;
1664 		x25_subscr.global_facil_mask = nb->global_facil_mask;
1665 		read_unlock_bh(&x25_neigh_list_lock);
1666 		rc = copy_to_user(x25_subscr32, &x25_subscr,
1667 				sizeof(*x25_subscr32)) ? -EFAULT : 0;
1668 	} else {
1669 		rc = -EINVAL;
1670 		if (x25_subscr.extended == 0 || x25_subscr.extended == 1) {
1671 			rc = 0;
1672 			write_lock_bh(&x25_neigh_list_lock);
1673 			nb->extended = x25_subscr.extended;
1674 			nb->global_facil_mask = x25_subscr.global_facil_mask;
1675 			write_unlock_bh(&x25_neigh_list_lock);
1676 		}
1677 	}
1678 	x25_neigh_put(nb);
1679 out:
1680 	return rc;
1681 out_dev_put:
1682 	dev_put(dev);
1683 	goto out;
1684 }
1685 
1686 static int compat_x25_ioctl(struct socket *sock, unsigned int cmd,
1687 				unsigned long arg)
1688 {
1689 	void __user *argp = compat_ptr(arg);
1690 	int rc = -ENOIOCTLCMD;
1691 
1692 	switch(cmd) {
1693 	case TIOCOUTQ:
1694 	case TIOCINQ:
1695 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1696 		break;
1697 	case SIOCGIFADDR:
1698 	case SIOCSIFADDR:
1699 	case SIOCGIFDSTADDR:
1700 	case SIOCSIFDSTADDR:
1701 	case SIOCGIFBRDADDR:
1702 	case SIOCSIFBRDADDR:
1703 	case SIOCGIFNETMASK:
1704 	case SIOCSIFNETMASK:
1705 	case SIOCGIFMETRIC:
1706 	case SIOCSIFMETRIC:
1707 		rc = -EINVAL;
1708 		break;
1709 	case SIOCADDRT:
1710 	case SIOCDELRT:
1711 		rc = -EPERM;
1712 		if (!capable(CAP_NET_ADMIN))
1713 			break;
1714 		rc = x25_route_ioctl(cmd, argp);
1715 		break;
1716 	case SIOCX25GSUBSCRIP:
1717 		rc = compat_x25_subscr_ioctl(cmd, argp);
1718 		break;
1719 	case SIOCX25SSUBSCRIP:
1720 		rc = -EPERM;
1721 		if (!capable(CAP_NET_ADMIN))
1722 			break;
1723 		rc = compat_x25_subscr_ioctl(cmd, argp);
1724 		break;
1725 	case SIOCX25GFACILITIES:
1726 	case SIOCX25SFACILITIES:
1727 	case SIOCX25GDTEFACILITIES:
1728 	case SIOCX25SDTEFACILITIES:
1729 	case SIOCX25GCALLUSERDATA:
1730 	case SIOCX25SCALLUSERDATA:
1731 	case SIOCX25GCAUSEDIAG:
1732 	case SIOCX25SCAUSEDIAG:
1733 	case SIOCX25SCUDMATCHLEN:
1734 	case SIOCX25CALLACCPTAPPRV:
1735 	case SIOCX25SENDCALLACCPT:
1736 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1737 		break;
1738 	default:
1739 		rc = -ENOIOCTLCMD;
1740 		break;
1741 	}
1742 	return rc;
1743 }
1744 #endif
1745 
1746 static const struct proto_ops x25_proto_ops = {
1747 	.family =	AF_X25,
1748 	.owner =	THIS_MODULE,
1749 	.release =	x25_release,
1750 	.bind =		x25_bind,
1751 	.connect =	x25_connect,
1752 	.socketpair =	sock_no_socketpair,
1753 	.accept =	x25_accept,
1754 	.getname =	x25_getname,
1755 	.poll =		datagram_poll,
1756 	.ioctl =	x25_ioctl,
1757 #ifdef CONFIG_COMPAT
1758 	.compat_ioctl = compat_x25_ioctl,
1759 #endif
1760 	.gettstamp =	sock_gettstamp,
1761 	.listen =	x25_listen,
1762 	.shutdown =	sock_no_shutdown,
1763 	.setsockopt =	x25_setsockopt,
1764 	.getsockopt =	x25_getsockopt,
1765 	.sendmsg =	x25_sendmsg,
1766 	.recvmsg =	x25_recvmsg,
1767 	.mmap =		sock_no_mmap,
1768 	.sendpage =	sock_no_sendpage,
1769 };
1770 
1771 static struct packet_type x25_packet_type __read_mostly = {
1772 	.type =	cpu_to_be16(ETH_P_X25),
1773 	.func =	x25_lapb_receive_frame,
1774 };
1775 
1776 static struct notifier_block x25_dev_notifier = {
1777 	.notifier_call = x25_device_event,
1778 };
1779 
1780 void x25_kill_by_neigh(struct x25_neigh *nb)
1781 {
1782 	struct sock *s;
1783 
1784 	write_lock_bh(&x25_list_lock);
1785 
1786 	sk_for_each(s, &x25_list)
1787 		if (x25_sk(s)->neighbour == nb)
1788 			x25_disconnect(s, ENETUNREACH, 0, 0);
1789 
1790 	write_unlock_bh(&x25_list_lock);
1791 
1792 	/* Remove any related forwards */
1793 	x25_clear_forward_by_dev(nb->dev);
1794 }
1795 
1796 static int __init x25_init(void)
1797 {
1798 	int rc;
1799 
1800 	rc = proto_register(&x25_proto, 0);
1801 	if (rc)
1802 		goto out;
1803 
1804 	rc = sock_register(&x25_family_ops);
1805 	if (rc)
1806 		goto out_proto;
1807 
1808 	dev_add_pack(&x25_packet_type);
1809 
1810 	rc = register_netdevice_notifier(&x25_dev_notifier);
1811 	if (rc)
1812 		goto out_sock;
1813 
1814 	rc = x25_register_sysctl();
1815 	if (rc)
1816 		goto out_dev;
1817 
1818 	rc = x25_proc_init();
1819 	if (rc)
1820 		goto out_sysctl;
1821 
1822 	pr_info("Linux Version 0.2\n");
1823 
1824 out:
1825 	return rc;
1826 out_sysctl:
1827 	x25_unregister_sysctl();
1828 out_dev:
1829 	unregister_netdevice_notifier(&x25_dev_notifier);
1830 out_sock:
1831 	dev_remove_pack(&x25_packet_type);
1832 	sock_unregister(AF_X25);
1833 out_proto:
1834 	proto_unregister(&x25_proto);
1835 	goto out;
1836 }
1837 module_init(x25_init);
1838 
1839 static void __exit x25_exit(void)
1840 {
1841 	x25_proc_exit();
1842 	x25_link_free();
1843 	x25_route_free();
1844 
1845 	x25_unregister_sysctl();
1846 
1847 	unregister_netdevice_notifier(&x25_dev_notifier);
1848 
1849 	dev_remove_pack(&x25_packet_type);
1850 
1851 	sock_unregister(AF_X25);
1852 	proto_unregister(&x25_proto);
1853 }
1854 module_exit(x25_exit);
1855 
1856 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
1857 MODULE_DESCRIPTION("The X.25 Packet Layer network layer protocol");
1858 MODULE_LICENSE("GPL");
1859 MODULE_ALIAS_NETPROTO(PF_X25);
1860