xref: /linux/net/x25/af_x25.c (revision 447edcb0e4be5d2ea26bc2e8439a6cf9adb8ebe5)
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 #include <linux/uio.h>
57 
58 #include <net/x25.h>
59 #include <net/compat.h>
60 
61 int sysctl_x25_restart_request_timeout = X25_DEFAULT_T20;
62 int sysctl_x25_call_request_timeout    = X25_DEFAULT_T21;
63 int sysctl_x25_reset_request_timeout   = X25_DEFAULT_T22;
64 int sysctl_x25_clear_request_timeout   = X25_DEFAULT_T23;
65 int sysctl_x25_ack_holdback_timeout    = X25_DEFAULT_T2;
66 int sysctl_x25_forward                 = 0;
67 
68 HLIST_HEAD(x25_list);
69 DEFINE_RWLOCK(x25_list_lock);
70 
71 static const struct proto_ops x25_proto_ops;
72 
73 static const struct x25_address null_x25_address = {"               "};
74 
75 #ifdef CONFIG_COMPAT
76 struct compat_x25_subscrip_struct {
77 	char device[200-sizeof(compat_ulong_t)];
78 	compat_ulong_t global_facil_mask;
79 	compat_uint_t extended;
80 };
81 #endif
82 
83 
84 int x25_parse_address_block(struct sk_buff *skb,
85 		struct x25_address *called_addr,
86 		struct x25_address *calling_addr)
87 {
88 	unsigned char len;
89 	int needed;
90 	int rc;
91 
92 	if (!pskb_may_pull(skb, 1)) {
93 		/* packet has no address block */
94 		rc = 0;
95 		goto empty;
96 	}
97 
98 	len = *skb->data;
99 	needed = 1 + ((len >> 4) + (len & 0x0f) + 1) / 2;
100 
101 	if (!pskb_may_pull(skb, needed)) {
102 		/* packet is too short to hold the addresses it claims
103 		   to hold */
104 		rc = -1;
105 		goto empty;
106 	}
107 
108 	return x25_addr_ntoa(skb->data, called_addr, calling_addr);
109 
110 empty:
111 	*called_addr->x25_addr = 0;
112 	*calling_addr->x25_addr = 0;
113 
114 	return rc;
115 }
116 
117 
118 int x25_addr_ntoa(unsigned char *p, struct x25_address *called_addr,
119 		  struct x25_address *calling_addr)
120 {
121 	unsigned int called_len, calling_len;
122 	char *called, *calling;
123 	unsigned int i;
124 
125 	called_len  = (*p >> 0) & 0x0F;
126 	calling_len = (*p >> 4) & 0x0F;
127 
128 	called  = called_addr->x25_addr;
129 	calling = calling_addr->x25_addr;
130 	p++;
131 
132 	for (i = 0; i < (called_len + calling_len); i++) {
133 		if (i < called_len) {
134 			if (i % 2 != 0) {
135 				*called++ = ((*p >> 0) & 0x0F) + '0';
136 				p++;
137 			} else {
138 				*called++ = ((*p >> 4) & 0x0F) + '0';
139 			}
140 		} else {
141 			if (i % 2 != 0) {
142 				*calling++ = ((*p >> 0) & 0x0F) + '0';
143 				p++;
144 			} else {
145 				*calling++ = ((*p >> 4) & 0x0F) + '0';
146 			}
147 		}
148 	}
149 
150 	*called = *calling = '\0';
151 
152 	return 1 + (called_len + calling_len + 1) / 2;
153 }
154 
155 int x25_addr_aton(unsigned char *p, struct x25_address *called_addr,
156 		  struct x25_address *calling_addr)
157 {
158 	unsigned int called_len, calling_len;
159 	char *called, *calling;
160 	int i;
161 
162 	called  = called_addr->x25_addr;
163 	calling = calling_addr->x25_addr;
164 
165 	called_len  = strlen(called);
166 	calling_len = strlen(calling);
167 
168 	*p++ = (calling_len << 4) | (called_len << 0);
169 
170 	for (i = 0; i < (called_len + calling_len); i++) {
171 		if (i < called_len) {
172 			if (i % 2 != 0) {
173 				*p |= (*called++ - '0') << 0;
174 				p++;
175 			} else {
176 				*p = 0x00;
177 				*p |= (*called++ - '0') << 4;
178 			}
179 		} else {
180 			if (i % 2 != 0) {
181 				*p |= (*calling++ - '0') << 0;
182 				p++;
183 			} else {
184 				*p = 0x00;
185 				*p |= (*calling++ - '0') << 4;
186 			}
187 		}
188 	}
189 
190 	return 1 + (called_len + calling_len + 1) / 2;
191 }
192 
193 /*
194  *	Socket removal during an interrupt is now safe.
195  */
196 static void x25_remove_socket(struct sock *sk)
197 {
198 	write_lock_bh(&x25_list_lock);
199 	sk_del_node_init(sk);
200 	write_unlock_bh(&x25_list_lock);
201 }
202 
203 /*
204  *	Handle device status changes.
205  */
206 static int x25_device_event(struct notifier_block *this, unsigned long event,
207 			    void *ptr)
208 {
209 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
210 	struct x25_neigh *nb;
211 
212 	if (!net_eq(dev_net(dev), &init_net))
213 		return NOTIFY_DONE;
214 
215 	if (dev->type == ARPHRD_X25) {
216 		switch (event) {
217 		case NETDEV_REGISTER:
218 		case NETDEV_POST_TYPE_CHANGE:
219 			x25_link_device_up(dev);
220 			break;
221 		case NETDEV_DOWN:
222 			nb = x25_get_neigh(dev);
223 			if (nb) {
224 				x25_link_terminated(nb);
225 				x25_neigh_put(nb);
226 			}
227 			x25_route_device_down(dev);
228 			break;
229 		case NETDEV_PRE_TYPE_CHANGE:
230 		case NETDEV_UNREGISTER:
231 			x25_link_device_down(dev);
232 			break;
233 		case NETDEV_CHANGE:
234 			if (!netif_carrier_ok(dev)) {
235 				nb = x25_get_neigh(dev);
236 				if (nb) {
237 					x25_link_terminated(nb);
238 					x25_neigh_put(nb);
239 				}
240 			}
241 			break;
242 		}
243 	}
244 
245 	return NOTIFY_DONE;
246 }
247 
248 /*
249  *	Add a socket to the bound sockets list.
250  */
251 static void x25_insert_socket(struct sock *sk)
252 {
253 	write_lock_bh(&x25_list_lock);
254 	sk_add_node(sk, &x25_list);
255 	write_unlock_bh(&x25_list_lock);
256 }
257 
258 /*
259  *	Find a socket that wants to accept the Call Request we just
260  *	received. Check the full list for an address/cud match.
261  *	If no cuds match return the next_best thing, an address match.
262  *	Note: if a listening socket has cud set it must only get calls
263  *	with matching cud.
264  */
265 static struct sock *x25_find_listener(struct x25_address *addr,
266 					struct sk_buff *skb)
267 {
268 	struct sock *s;
269 	struct sock *next_best;
270 
271 	read_lock_bh(&x25_list_lock);
272 	next_best = NULL;
273 
274 	sk_for_each(s, &x25_list)
275 		if ((!strcmp(addr->x25_addr,
276 			x25_sk(s)->source_addr.x25_addr) ||
277 				!strcmp(x25_sk(s)->source_addr.x25_addr,
278 					null_x25_address.x25_addr)) &&
279 					s->sk_state == TCP_LISTEN) {
280 			/*
281 			 * Found a listening socket, now check the incoming
282 			 * call user data vs this sockets call user data
283 			 */
284 			if (x25_sk(s)->cudmatchlength > 0 &&
285 				skb->len >= x25_sk(s)->cudmatchlength) {
286 				if((memcmp(x25_sk(s)->calluserdata.cuddata,
287 					skb->data,
288 					x25_sk(s)->cudmatchlength)) == 0) {
289 					sock_hold(s);
290 					goto found;
291 				 }
292 			} else
293 				next_best = s;
294 		}
295 	if (next_best) {
296 		s = next_best;
297 		sock_hold(s);
298 		goto found;
299 	}
300 	s = NULL;
301 found:
302 	read_unlock_bh(&x25_list_lock);
303 	return s;
304 }
305 
306 /*
307  *	Find a connected X.25 socket given my LCI and neighbour.
308  */
309 static struct sock *__x25_find_socket(unsigned int lci, struct x25_neigh *nb)
310 {
311 	struct sock *s;
312 
313 	sk_for_each(s, &x25_list)
314 		if (x25_sk(s)->lci == lci && x25_sk(s)->neighbour == nb) {
315 			sock_hold(s);
316 			goto found;
317 		}
318 	s = NULL;
319 found:
320 	return s;
321 }
322 
323 struct sock *x25_find_socket(unsigned int lci, struct x25_neigh *nb)
324 {
325 	struct sock *s;
326 
327 	read_lock_bh(&x25_list_lock);
328 	s = __x25_find_socket(lci, nb);
329 	read_unlock_bh(&x25_list_lock);
330 	return s;
331 }
332 
333 /*
334  *	Find a unique LCI for a given device.
335  */
336 static unsigned int x25_new_lci(struct x25_neigh *nb)
337 {
338 	unsigned int lci = 1;
339 	struct sock *sk;
340 
341 	while ((sk = x25_find_socket(lci, nb)) != NULL) {
342 		sock_put(sk);
343 		if (++lci == 4096) {
344 			lci = 0;
345 			break;
346 		}
347 		cond_resched();
348 	}
349 
350 	return lci;
351 }
352 
353 /*
354  *	Deferred destroy.
355  */
356 static void __x25_destroy_socket(struct sock *);
357 
358 /*
359  *	handler for deferred kills.
360  */
361 static void x25_destroy_timer(struct timer_list *t)
362 {
363 	struct sock *sk = timer_container_of(sk, t, sk_timer);
364 
365 	x25_destroy_socket_from_timer(sk);
366 }
367 
368 /*
369  *	This is called from user mode and the timers. Thus it protects itself
370  *	against interrupting users but doesn't worry about being called during
371  *	work. Once it is removed from the queue no interrupt or bottom half
372  *	will touch it and we are (fairly 8-) ) safe.
373  *	Not static as it's used by the timer
374  */
375 static void __x25_destroy_socket(struct sock *sk)
376 {
377 	struct sk_buff *skb;
378 
379 	x25_stop_heartbeat(sk);
380 	x25_stop_timer(sk);
381 
382 	x25_remove_socket(sk);
383 	x25_clear_queues(sk);		/* Flush the queues */
384 
385 	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
386 		if (skb->sk != sk) {		/* A pending connection */
387 			/*
388 			 * Queue the unaccepted socket for death
389 			 */
390 			skb->sk->sk_state = TCP_LISTEN;
391 			sock_set_flag(skb->sk, SOCK_DEAD);
392 			x25_start_heartbeat(skb->sk);
393 			x25_sk(skb->sk)->state = X25_STATE_0;
394 		}
395 
396 		kfree_skb(skb);
397 	}
398 
399 	if (sk_has_allocations(sk)) {
400 		/* Defer: outstanding buffers */
401 		sk->sk_timer.expires  = jiffies + 10 * HZ;
402 		sk->sk_timer.function = x25_destroy_timer;
403 		add_timer(&sk->sk_timer);
404 	} else {
405 		/* drop last reference so sock_put will free */
406 		__sock_put(sk);
407 	}
408 }
409 
410 void x25_destroy_socket_from_timer(struct sock *sk)
411 {
412 	sock_hold(sk);
413 	bh_lock_sock(sk);
414 	__x25_destroy_socket(sk);
415 	bh_unlock_sock(sk);
416 	sock_put(sk);
417 }
418 
419 /*
420  *	Handling for system calls applied via the various interfaces to a
421  *	X.25 socket object.
422  */
423 
424 static int x25_setsockopt(struct socket *sock, int level, int optname,
425 			  sockptr_t optval, unsigned int optlen)
426 {
427 	int opt;
428 	struct sock *sk = sock->sk;
429 	int rc = -ENOPROTOOPT;
430 
431 	if (level != SOL_X25 || optname != X25_QBITINCL)
432 		goto out;
433 
434 	rc = -EINVAL;
435 	if (optlen < sizeof(int))
436 		goto out;
437 
438 	rc = -EFAULT;
439 	if (copy_from_sockptr(&opt, optval, sizeof(int)))
440 		goto out;
441 
442 	if (opt)
443 		set_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
444 	else
445 		clear_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
446 	rc = 0;
447 out:
448 	return rc;
449 }
450 
451 static int x25_getsockopt(struct socket *sock, int level, int optname,
452 			  sockopt_t *opt)
453 {
454 	struct sock *sk = sock->sk;
455 	int val, len, rc = -ENOPROTOOPT;
456 
457 	if (level != SOL_X25 || optname != X25_QBITINCL)
458 		goto out;
459 
460 	len = opt->optlen;
461 
462 	rc = -EINVAL;
463 	if (len < 0)
464 		goto out;
465 
466 	len = min_t(unsigned int, len, sizeof(int));
467 	opt->optlen = len;
468 
469 	val = test_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
470 	rc = copy_to_iter(&val, len, &opt->iter_out) != len ? -EFAULT : 0;
471 out:
472 	return rc;
473 }
474 
475 static int x25_listen(struct socket *sock, int backlog)
476 {
477 	struct sock *sk = sock->sk;
478 	int rc = -EOPNOTSUPP;
479 
480 	lock_sock(sk);
481 	if (sock->state != SS_UNCONNECTED) {
482 		rc = -EINVAL;
483 		release_sock(sk);
484 		return rc;
485 	}
486 
487 	if (sk->sk_state != TCP_LISTEN) {
488 		memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN);
489 		sk->sk_max_ack_backlog = backlog;
490 		sk->sk_state           = TCP_LISTEN;
491 		rc = 0;
492 	}
493 	release_sock(sk);
494 
495 	return rc;
496 }
497 
498 static struct proto x25_proto = {
499 	.name	  = "X25",
500 	.owner	  = THIS_MODULE,
501 	.obj_size = sizeof(struct x25_sock),
502 };
503 
504 static struct sock *x25_alloc_socket(struct net *net, int kern)
505 {
506 	struct x25_sock *x25;
507 	struct sock *sk = sk_alloc(net, AF_X25, GFP_ATOMIC, &x25_proto, kern);
508 
509 	if (!sk)
510 		goto out;
511 
512 	sock_init_data(NULL, sk);
513 
514 	x25 = x25_sk(sk);
515 	skb_queue_head_init(&x25->ack_queue);
516 	skb_queue_head_init(&x25->fragment_queue);
517 	skb_queue_head_init(&x25->interrupt_in_queue);
518 	skb_queue_head_init(&x25->interrupt_out_queue);
519 out:
520 	return sk;
521 }
522 
523 static int x25_create(struct net *net, struct socket *sock, int protocol,
524 		      int kern)
525 {
526 	struct sock *sk;
527 	struct x25_sock *x25;
528 	int rc = -EAFNOSUPPORT;
529 
530 	if (!net_eq(net, &init_net))
531 		goto out;
532 
533 	rc = -ESOCKTNOSUPPORT;
534 	if (sock->type != SOCK_SEQPACKET)
535 		goto out;
536 
537 	rc = -EINVAL;
538 	if (protocol)
539 		goto out;
540 
541 	rc = -ENOMEM;
542 	if ((sk = x25_alloc_socket(net, kern)) == NULL)
543 		goto out;
544 
545 	x25 = x25_sk(sk);
546 
547 	sock_init_data(sock, sk);
548 
549 	x25_init_timers(sk);
550 
551 	sock->ops    = &x25_proto_ops;
552 	sk->sk_protocol = protocol;
553 	sk->sk_backlog_rcv = x25_backlog_rcv;
554 
555 	x25->t21   = sysctl_x25_call_request_timeout;
556 	x25->t22   = sysctl_x25_reset_request_timeout;
557 	x25->t23   = sysctl_x25_clear_request_timeout;
558 	x25->t2    = sysctl_x25_ack_holdback_timeout;
559 	x25->state = X25_STATE_0;
560 	x25->cudmatchlength = 0;
561 	set_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);	/* normally no cud  */
562 							/* on call accept   */
563 
564 	x25->facilities.winsize_in  = X25_DEFAULT_WINDOW_SIZE;
565 	x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
566 	x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
567 	x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
568 	x25->facilities.throughput  = 0;	/* by default don't negotiate
569 						   throughput */
570 	x25->facilities.reverse     = X25_DEFAULT_REVERSE;
571 	x25->dte_facilities.calling_len = 0;
572 	x25->dte_facilities.called_len = 0;
573 	memset(x25->dte_facilities.called_ae, '\0',
574 			sizeof(x25->dte_facilities.called_ae));
575 	memset(x25->dte_facilities.calling_ae, '\0',
576 			sizeof(x25->dte_facilities.calling_ae));
577 
578 	rc = 0;
579 out:
580 	return rc;
581 }
582 
583 static struct sock *x25_make_new(struct sock *osk)
584 {
585 	struct sock *sk = NULL;
586 	struct x25_sock *x25, *ox25;
587 
588 	if (osk->sk_type != SOCK_SEQPACKET)
589 		goto out;
590 
591 	if ((sk = x25_alloc_socket(sock_net(osk), 0)) == NULL)
592 		goto out;
593 
594 	x25 = x25_sk(sk);
595 
596 	sk->sk_type        = osk->sk_type;
597 	sk->sk_priority    = READ_ONCE(osk->sk_priority);
598 	sk->sk_protocol    = osk->sk_protocol;
599 	sk->sk_rcvbuf      = osk->sk_rcvbuf;
600 	sk->sk_sndbuf      = osk->sk_sndbuf;
601 	sk->sk_state       = TCP_ESTABLISHED;
602 	sk->sk_backlog_rcv = osk->sk_backlog_rcv;
603 	sock_copy_flags(sk, osk);
604 
605 	ox25 = x25_sk(osk);
606 	x25->t21        = ox25->t21;
607 	x25->t22        = ox25->t22;
608 	x25->t23        = ox25->t23;
609 	x25->t2         = ox25->t2;
610 	x25->flags	= ox25->flags;
611 	x25->facilities = ox25->facilities;
612 	x25->dte_facilities = ox25->dte_facilities;
613 	x25->cudmatchlength = ox25->cudmatchlength;
614 
615 	clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
616 	x25_init_timers(sk);
617 out:
618 	return sk;
619 }
620 
621 static int x25_release(struct socket *sock)
622 {
623 	struct sock *sk = sock->sk;
624 	struct x25_sock *x25;
625 
626 	if (!sk)
627 		return 0;
628 
629 	x25 = x25_sk(sk);
630 
631 	sock_hold(sk);
632 	lock_sock(sk);
633 	switch (x25->state) {
634 
635 		case X25_STATE_0:
636 		case X25_STATE_2:
637 			x25_disconnect(sk, 0, 0, 0);
638 			__x25_destroy_socket(sk);
639 			goto out;
640 
641 		case X25_STATE_1:
642 		case X25_STATE_3:
643 		case X25_STATE_4:
644 			x25_clear_queues(sk);
645 			x25_write_internal(sk, X25_CLEAR_REQUEST);
646 			x25_start_t23timer(sk);
647 			x25->state = X25_STATE_2;
648 			sk->sk_state	= TCP_CLOSE;
649 			sk->sk_shutdown	|= SEND_SHUTDOWN;
650 			sk->sk_state_change(sk);
651 			sock_set_flag(sk, SOCK_DEAD);
652 			sock_set_flag(sk, SOCK_DESTROY);
653 			break;
654 
655 		case X25_STATE_5:
656 			x25_write_internal(sk, X25_CLEAR_REQUEST);
657 			x25_disconnect(sk, 0, 0, 0);
658 			__x25_destroy_socket(sk);
659 			goto out;
660 	}
661 
662 	sock_orphan(sk);
663 out:
664 	release_sock(sk);
665 	sock_put(sk);
666 	return 0;
667 }
668 
669 static int x25_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int addr_len)
670 {
671 	struct sock *sk = sock->sk;
672 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
673 	int len, i, rc = 0;
674 
675 	if (addr_len != sizeof(struct sockaddr_x25) ||
676 	    addr->sx25_family != AF_X25 ||
677 	    strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) {
678 		rc = -EINVAL;
679 		goto out;
680 	}
681 
682 	/* check for the null_x25_address */
683 	if (strcmp(addr->sx25_addr.x25_addr, null_x25_address.x25_addr)) {
684 
685 		len = strlen(addr->sx25_addr.x25_addr);
686 		for (i = 0; i < len; i++) {
687 			if (!isdigit(addr->sx25_addr.x25_addr[i])) {
688 				rc = -EINVAL;
689 				goto out;
690 			}
691 		}
692 	}
693 
694 	lock_sock(sk);
695 	if (sock_flag(sk, SOCK_ZAPPED)) {
696 		x25_sk(sk)->source_addr = addr->sx25_addr;
697 		x25_insert_socket(sk);
698 		sock_reset_flag(sk, SOCK_ZAPPED);
699 	} else {
700 		rc = -EINVAL;
701 	}
702 	release_sock(sk);
703 	net_dbg_ratelimited("x25_bind: socket is bound\n");
704 out:
705 	return rc;
706 }
707 
708 static int x25_wait_for_connection_establishment(struct sock *sk)
709 {
710 	DECLARE_WAITQUEUE(wait, current);
711 	int rc;
712 
713 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
714 	for (;;) {
715 		__set_current_state(TASK_INTERRUPTIBLE);
716 		rc = -ERESTARTSYS;
717 		if (signal_pending(current))
718 			break;
719 		rc = sock_error(sk);
720 		if (rc) {
721 			sk->sk_socket->state = SS_UNCONNECTED;
722 			break;
723 		}
724 		rc = -ENOTCONN;
725 		if (sk->sk_state == TCP_CLOSE) {
726 			sk->sk_socket->state = SS_UNCONNECTED;
727 			break;
728 		}
729 		rc = 0;
730 		if (sk->sk_state != TCP_ESTABLISHED) {
731 			release_sock(sk);
732 			schedule();
733 			lock_sock(sk);
734 		} else
735 			break;
736 	}
737 	__set_current_state(TASK_RUNNING);
738 	remove_wait_queue(sk_sleep(sk), &wait);
739 	return rc;
740 }
741 
742 static int x25_connect(struct socket *sock, struct sockaddr_unsized *uaddr,
743 		       int addr_len, int flags)
744 {
745 	struct sock *sk = sock->sk;
746 	struct x25_sock *x25 = x25_sk(sk);
747 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
748 	struct x25_route *rt;
749 	int rc = 0;
750 
751 	lock_sock(sk);
752 	if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
753 		sock->state = SS_CONNECTED;
754 		goto out; /* Connect completed during a ERESTARTSYS event */
755 	}
756 
757 	rc = -ECONNREFUSED;
758 	if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
759 		sock->state = SS_UNCONNECTED;
760 		goto out;
761 	}
762 
763 	rc = -EISCONN;	/* No reconnect on a seqpacket socket */
764 	if (sk->sk_state == TCP_ESTABLISHED)
765 		goto out;
766 
767 	rc = -EALREADY;	/* Do nothing if call is already in progress */
768 	if (sk->sk_state == TCP_SYN_SENT)
769 		goto out;
770 
771 	sk->sk_state   = TCP_CLOSE;
772 	sock->state = SS_UNCONNECTED;
773 
774 	rc = -EINVAL;
775 	if (addr_len != sizeof(struct sockaddr_x25) ||
776 	    addr->sx25_family != AF_X25 ||
777 	    strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN)
778 		goto out;
779 
780 	rc = -ENETUNREACH;
781 	rt = x25_get_route(&addr->sx25_addr);
782 	if (!rt)
783 		goto out;
784 
785 	x25->neighbour = x25_get_neigh(rt->dev);
786 	if (!x25->neighbour)
787 		goto out_put_route;
788 
789 	x25_limit_facilities(&x25->facilities, x25->neighbour);
790 
791 	x25->lci = x25_new_lci(x25->neighbour);
792 	if (!x25->lci)
793 		goto out_put_neigh;
794 
795 	rc = -EINVAL;
796 	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
797 		goto out_put_neigh;
798 
799 	if (!strcmp(x25->source_addr.x25_addr, null_x25_address.x25_addr))
800 		memset(&x25->source_addr, '\0', X25_ADDR_LEN);
801 
802 	x25->dest_addr = addr->sx25_addr;
803 
804 	/* Move to connecting socket, start sending Connect Requests */
805 	sock->state   = SS_CONNECTING;
806 	sk->sk_state  = TCP_SYN_SENT;
807 
808 	x25->state = X25_STATE_1;
809 
810 	x25_write_internal(sk, X25_CALL_REQUEST);
811 
812 	x25_start_heartbeat(sk);
813 	x25_start_t21timer(sk);
814 
815 	/* Now the loop */
816 	rc = -EINPROGRESS;
817 	if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK))
818 		goto out;
819 
820 	rc = x25_wait_for_connection_establishment(sk);
821 	if (rc)
822 		goto out_put_neigh;
823 
824 	sock->state = SS_CONNECTED;
825 	rc = 0;
826 out_put_neigh:
827 	if (rc && x25->neighbour) {
828 		read_lock_bh(&x25_list_lock);
829 		x25_neigh_put(x25->neighbour);
830 		x25->neighbour = NULL;
831 		read_unlock_bh(&x25_list_lock);
832 		x25->state = X25_STATE_0;
833 	}
834 out_put_route:
835 	x25_route_put(rt);
836 out:
837 	release_sock(sk);
838 	return rc;
839 }
840 
841 static int x25_wait_for_data(struct sock *sk, long timeout)
842 {
843 	DECLARE_WAITQUEUE(wait, current);
844 	int rc = 0;
845 
846 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
847 	for (;;) {
848 		__set_current_state(TASK_INTERRUPTIBLE);
849 		if (sk->sk_shutdown & RCV_SHUTDOWN)
850 			break;
851 		rc = -ERESTARTSYS;
852 		if (signal_pending(current))
853 			break;
854 		rc = -EAGAIN;
855 		if (!timeout)
856 			break;
857 		rc = 0;
858 		if (skb_queue_empty(&sk->sk_receive_queue)) {
859 			release_sock(sk);
860 			timeout = schedule_timeout(timeout);
861 			lock_sock(sk);
862 		} else
863 			break;
864 	}
865 	__set_current_state(TASK_RUNNING);
866 	remove_wait_queue(sk_sleep(sk), &wait);
867 	return rc;
868 }
869 
870 static int x25_accept(struct socket *sock, struct socket *newsock,
871 		      struct proto_accept_arg *arg)
872 {
873 	struct sock *sk = sock->sk;
874 	struct sock *newsk;
875 	struct sk_buff *skb;
876 	int rc = -EINVAL;
877 
878 	if (!sk)
879 		goto out;
880 
881 	rc = -EOPNOTSUPP;
882 	if (sk->sk_type != SOCK_SEQPACKET)
883 		goto out;
884 
885 	lock_sock(sk);
886 	rc = -EINVAL;
887 	if (sk->sk_state != TCP_LISTEN)
888 		goto out2;
889 
890 	rc = x25_wait_for_data(sk, READ_ONCE(sk->sk_rcvtimeo));
891 	if (rc)
892 		goto out2;
893 	skb = skb_dequeue(&sk->sk_receive_queue);
894 	rc = -EINVAL;
895 	if (!skb->sk)
896 		goto out2;
897 	newsk		 = skb->sk;
898 	sock_graft(newsk, newsock);
899 
900 	/* Now attach up the new socket */
901 	skb->sk = NULL;
902 	kfree_skb(skb);
903 	sk_acceptq_removed(sk);
904 	newsock->state = SS_CONNECTED;
905 	rc = 0;
906 out2:
907 	release_sock(sk);
908 out:
909 	return rc;
910 }
911 
912 static int x25_getname(struct socket *sock, struct sockaddr *uaddr,
913 		       int peer)
914 {
915 	struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)uaddr;
916 	struct sock *sk = sock->sk;
917 	struct x25_sock *x25 = x25_sk(sk);
918 	int rc = 0;
919 
920 	if (peer) {
921 		if (sk->sk_state != TCP_ESTABLISHED) {
922 			rc = -ENOTCONN;
923 			goto out;
924 		}
925 		sx25->sx25_addr = x25->dest_addr;
926 	} else
927 		sx25->sx25_addr = x25->source_addr;
928 
929 	sx25->sx25_family = AF_X25;
930 	rc = sizeof(*sx25);
931 
932 out:
933 	return rc;
934 }
935 
936 int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
937 			unsigned int lci)
938 {
939 	struct sock *sk;
940 	struct sock *make;
941 	struct x25_sock *makex25;
942 	struct x25_address source_addr, dest_addr;
943 	struct x25_facilities facilities;
944 	struct x25_dte_facilities dte_facilities;
945 	int len, addr_len, rc;
946 
947 	/*
948 	 *	Remove the LCI and frame type.
949 	 */
950 	skb_pull(skb, X25_STD_MIN_LEN);
951 
952 	/*
953 	 *	Extract the X.25 addresses and convert them to ASCII strings,
954 	 *	and remove them.
955 	 *
956 	 *	Address block is mandatory in call request packets
957 	 */
958 	addr_len = x25_parse_address_block(skb, &source_addr, &dest_addr);
959 	if (addr_len <= 0)
960 		goto out_clear_request;
961 	skb_pull(skb, addr_len);
962 
963 	/*
964 	 *	Get the length of the facilities, skip past them for the moment
965 	 *	get the call user data because this is needed to determine
966 	 *	the correct listener
967 	 *
968 	 *	Facilities length is mandatory in call request packets
969 	 */
970 	if (!pskb_may_pull(skb, 1))
971 		goto out_clear_request;
972 	len = skb->data[0] + 1;
973 	if (!pskb_may_pull(skb, len))
974 		goto out_clear_request;
975 	skb_pull(skb,len);
976 
977 	/*
978 	 *	Ensure that the amount of call user data is valid.
979 	 */
980 	if (skb->len > X25_MAX_CUD_LEN)
981 		goto out_clear_request;
982 
983 	/*
984 	 *	Get all the call user data so it can be used in
985 	 *	x25_find_listener and skb_copy_from_linear_data up ahead.
986 	 */
987 	if (!pskb_may_pull(skb, skb->len))
988 		goto out_clear_request;
989 
990 	/*
991 	 *	Find a listener for the particular address/cud pair.
992 	 */
993 	sk = x25_find_listener(&source_addr,skb);
994 	skb_push(skb,len);
995 
996 	if (sk != NULL && sk_acceptq_is_full(sk)) {
997 		goto out_sock_put;
998 	}
999 
1000 	/*
1001 	 *	We dont have any listeners for this incoming call.
1002 	 *	Try forwarding it.
1003 	 */
1004 	if (sk == NULL) {
1005 		skb_push(skb, addr_len + X25_STD_MIN_LEN);
1006 		if (sysctl_x25_forward &&
1007 				x25_forward_call(&dest_addr, nb, skb, lci) > 0)
1008 		{
1009 			/* Call was forwarded, dont process it any more */
1010 			kfree_skb(skb);
1011 			rc = 1;
1012 			goto out;
1013 		} else {
1014 			/* No listeners, can't forward, clear the call */
1015 			goto out_clear_request;
1016 		}
1017 	}
1018 
1019 	/*
1020 	 *	Try to reach a compromise on the requested facilities.
1021 	 */
1022 	len = x25_negotiate_facilities(skb, sk, &facilities, &dte_facilities);
1023 	if (len == -1)
1024 		goto out_sock_put;
1025 
1026 	/*
1027 	 * current neighbour/link might impose additional limits
1028 	 * on certain facilities
1029 	 */
1030 
1031 	x25_limit_facilities(&facilities, nb);
1032 
1033 	/*
1034 	 *	Try to create a new socket.
1035 	 */
1036 	make = x25_make_new(sk);
1037 	if (!make)
1038 		goto out_sock_put;
1039 
1040 	/*
1041 	 *	Remove the facilities
1042 	 */
1043 	skb_pull(skb, len);
1044 
1045 	skb->sk     = make;
1046 	make->sk_state = TCP_ESTABLISHED;
1047 
1048 	makex25 = x25_sk(make);
1049 	makex25->lci           = lci;
1050 	makex25->dest_addr     = dest_addr;
1051 	makex25->source_addr   = source_addr;
1052 	x25_neigh_hold(nb);
1053 	makex25->neighbour     = nb;
1054 	makex25->facilities    = facilities;
1055 	makex25->dte_facilities= dte_facilities;
1056 	makex25->vc_facil_mask = x25_sk(sk)->vc_facil_mask;
1057 	/* ensure no reverse facil on accept */
1058 	makex25->vc_facil_mask &= ~X25_MASK_REVERSE;
1059 	/* ensure no calling address extension on accept */
1060 	makex25->vc_facil_mask &= ~X25_MASK_CALLING_AE;
1061 	makex25->cudmatchlength = x25_sk(sk)->cudmatchlength;
1062 
1063 	/* Normally all calls are accepted immediately */
1064 	if (test_bit(X25_ACCPT_APPRV_FLAG, &makex25->flags)) {
1065 		x25_write_internal(make, X25_CALL_ACCEPTED);
1066 		makex25->state = X25_STATE_3;
1067 	} else {
1068 		makex25->state = X25_STATE_5;
1069 	}
1070 
1071 	/*
1072 	 *	Incoming Call User Data.
1073 	 */
1074 	skb_copy_from_linear_data(skb, makex25->calluserdata.cuddata, skb->len);
1075 	makex25->calluserdata.cudlength = skb->len;
1076 
1077 	sk_acceptq_added(sk);
1078 
1079 	x25_insert_socket(make);
1080 
1081 	skb_queue_head(&sk->sk_receive_queue, skb);
1082 
1083 	x25_start_heartbeat(make);
1084 
1085 	if (!sock_flag(sk, SOCK_DEAD))
1086 		sk->sk_data_ready(sk);
1087 	rc = 1;
1088 	sock_put(sk);
1089 out:
1090 	return rc;
1091 out_sock_put:
1092 	sock_put(sk);
1093 out_clear_request:
1094 	rc = 0;
1095 	x25_transmit_clear_request(nb, lci, 0x01);
1096 	goto out;
1097 }
1098 
1099 static int x25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1100 {
1101 	struct sock *sk = sock->sk;
1102 	struct x25_sock *x25 = x25_sk(sk);
1103 	DECLARE_SOCKADDR(struct sockaddr_x25 *, usx25, msg->msg_name);
1104 	struct sockaddr_x25 sx25;
1105 	struct sk_buff *skb;
1106 	unsigned char *asmptr;
1107 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1108 	size_t size;
1109 	int qbit = 0, rc = -EINVAL;
1110 
1111 	lock_sock(sk);
1112 	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_OOB|MSG_EOR|MSG_CMSG_COMPAT))
1113 		goto out;
1114 
1115 	/* we currently don't support segmented records at the user interface */
1116 	if (!(msg->msg_flags & (MSG_EOR|MSG_OOB)))
1117 		goto out;
1118 
1119 	rc = -EADDRNOTAVAIL;
1120 	if (sock_flag(sk, SOCK_ZAPPED))
1121 		goto out;
1122 
1123 	rc = -EPIPE;
1124 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1125 		send_sig(SIGPIPE, current, 0);
1126 		goto out;
1127 	}
1128 
1129 	rc = -ENETUNREACH;
1130 	if (!x25->neighbour)
1131 		goto out;
1132 
1133 	if (usx25) {
1134 		rc = -EINVAL;
1135 		if (msg->msg_namelen < sizeof(sx25))
1136 			goto out;
1137 		memcpy(&sx25, usx25, sizeof(sx25));
1138 		rc = -EISCONN;
1139 		if (strcmp(x25->dest_addr.x25_addr, sx25.sx25_addr.x25_addr))
1140 			goto out;
1141 		rc = -EINVAL;
1142 		if (sx25.sx25_family != AF_X25)
1143 			goto out;
1144 	} else {
1145 		/*
1146 		 *	FIXME 1003.1g - if the socket is like this because
1147 		 *	it has become closed (not started closed) we ought
1148 		 *	to SIGPIPE, EPIPE;
1149 		 */
1150 		rc = -ENOTCONN;
1151 		if (sk->sk_state != TCP_ESTABLISHED)
1152 			goto out;
1153 
1154 		sx25.sx25_family = AF_X25;
1155 		sx25.sx25_addr   = x25->dest_addr;
1156 	}
1157 
1158 	/* Sanity check the packet size */
1159 	if (len > 65535) {
1160 		rc = -EMSGSIZE;
1161 		goto out;
1162 	}
1163 
1164 	net_dbg_ratelimited("x25_sendmsg: sendto: Addresses built.\n");
1165 
1166 	/* Build a packet */
1167 	net_dbg_ratelimited("x25_sendmsg: sendto: building packet.\n");
1168 
1169 	if ((msg->msg_flags & MSG_OOB) && len > 32)
1170 		len = 32;
1171 
1172 	size = len + X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
1173 
1174 	release_sock(sk);
1175 	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
1176 	lock_sock(sk);
1177 	if (!skb)
1178 		goto out;
1179 	X25_SKB_CB(skb)->flags = msg->msg_flags;
1180 
1181 	skb_reserve(skb, X25_MAX_L2_LEN + X25_EXT_MIN_LEN);
1182 
1183 	/*
1184 	 *	Put the data on the end
1185 	 */
1186 	net_dbg_ratelimited("x25_sendmsg: Copying user data\n");
1187 
1188 	skb_reset_transport_header(skb);
1189 	skb_put(skb, len);
1190 
1191 	rc = memcpy_from_msg(skb_transport_header(skb), msg, len);
1192 	if (rc)
1193 		goto out_kfree_skb;
1194 
1195 	/*
1196 	 *	If the Q BIT Include socket option is in force, the first
1197 	 *	byte of the user data is the logical value of the Q Bit.
1198 	 */
1199 	if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1200 		if (!pskb_may_pull(skb, 1))
1201 			goto out_kfree_skb;
1202 
1203 		qbit = skb->data[0];
1204 		skb_pull(skb, 1);
1205 	}
1206 
1207 	/*
1208 	 *	Push down the X.25 header
1209 	 */
1210 	net_dbg_ratelimited("x25_sendmsg: Building X.25 Header.\n");
1211 
1212 	if (msg->msg_flags & MSG_OOB) {
1213 		if (x25->neighbour->extended) {
1214 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1215 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1216 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1217 			*asmptr++ = X25_INTERRUPT;
1218 		} else {
1219 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1220 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1221 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1222 			*asmptr++ = X25_INTERRUPT;
1223 		}
1224 	} else {
1225 		if (x25->neighbour->extended) {
1226 			/* Build an Extended X.25 header */
1227 			asmptr    = skb_push(skb, X25_EXT_MIN_LEN);
1228 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1229 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1230 			*asmptr++ = X25_DATA;
1231 			*asmptr++ = X25_DATA;
1232 		} else {
1233 			/* Build an Standard X.25 header */
1234 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1235 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1236 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1237 			*asmptr++ = X25_DATA;
1238 		}
1239 
1240 		if (qbit)
1241 			skb->data[0] |= X25_Q_BIT;
1242 	}
1243 
1244 	net_dbg_ratelimited("x25_sendmsg: Built header.\n");
1245 	net_dbg_ratelimited("x25_sendmsg: Transmitting buffer\n");
1246 
1247 	rc = -ENOTCONN;
1248 	if (sk->sk_state != TCP_ESTABLISHED)
1249 		goto out_kfree_skb;
1250 
1251 	if (msg->msg_flags & MSG_OOB)
1252 		skb_queue_tail(&x25->interrupt_out_queue, skb);
1253 	else {
1254 		rc = x25_output(sk, skb);
1255 		len = rc;
1256 		if (rc < 0)
1257 			kfree_skb(skb);
1258 		else if (test_bit(X25_Q_BIT_FLAG, &x25->flags))
1259 			len++;
1260 	}
1261 
1262 	x25_kick(sk);
1263 	rc = len;
1264 out:
1265 	release_sock(sk);
1266 	return rc;
1267 out_kfree_skb:
1268 	kfree_skb(skb);
1269 	goto out;
1270 }
1271 
1272 
1273 static int x25_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1274 		       int flags)
1275 {
1276 	struct sock *sk = sock->sk;
1277 	struct x25_sock *x25 = x25_sk(sk);
1278 	DECLARE_SOCKADDR(struct sockaddr_x25 *, sx25, msg->msg_name);
1279 	size_t copied;
1280 	int qbit, header_len;
1281 	struct sk_buff *skb;
1282 	unsigned char *asmptr;
1283 	int rc = -ENOTCONN;
1284 
1285 	lock_sock(sk);
1286 
1287 	if (x25->neighbour == NULL)
1288 		goto out;
1289 
1290 	header_len = x25->neighbour->extended ?
1291 		X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
1292 
1293 	/*
1294 	 * This works for seqpacket too. The receiver has ordered the queue for
1295 	 * us! We do one quick check first though
1296 	 */
1297 	if (sk->sk_state != TCP_ESTABLISHED)
1298 		goto out;
1299 
1300 	if (flags & MSG_OOB) {
1301 		rc = -EINVAL;
1302 		if (sock_flag(sk, SOCK_URGINLINE) ||
1303 		    !skb_peek(&x25->interrupt_in_queue))
1304 			goto out;
1305 
1306 		skb = skb_dequeue(&x25->interrupt_in_queue);
1307 
1308 		if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
1309 			goto out_free_dgram;
1310 
1311 		skb_pull(skb, X25_STD_MIN_LEN);
1312 
1313 		/*
1314 		 *	No Q bit information on Interrupt data.
1315 		 */
1316 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1317 			asmptr  = skb_push(skb, 1);
1318 			*asmptr = 0x00;
1319 		}
1320 
1321 		msg->msg_flags |= MSG_OOB;
1322 	} else {
1323 		/* Now we can treat all alike */
1324 		release_sock(sk);
1325 		skb = skb_recv_datagram(sk, flags, &rc);
1326 		lock_sock(sk);
1327 		if (!skb)
1328 			goto out;
1329 
1330 		if (!pskb_may_pull(skb, header_len))
1331 			goto out_free_dgram;
1332 
1333 		qbit = (skb->data[0] & X25_Q_BIT) == X25_Q_BIT;
1334 
1335 		skb_pull(skb, header_len);
1336 
1337 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1338 			asmptr  = skb_push(skb, 1);
1339 			*asmptr = qbit;
1340 		}
1341 	}
1342 
1343 	skb_reset_transport_header(skb);
1344 	copied = skb->len;
1345 
1346 	if (copied > size) {
1347 		copied = size;
1348 		msg->msg_flags |= MSG_TRUNC;
1349 	}
1350 
1351 	/* Currently, each datagram always contains a complete record */
1352 	msg->msg_flags |= MSG_EOR;
1353 
1354 	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
1355 	if (rc)
1356 		goto out_free_dgram;
1357 
1358 	if (sx25) {
1359 		sx25->sx25_family = AF_X25;
1360 		sx25->sx25_addr   = x25->dest_addr;
1361 		msg->msg_namelen = sizeof(*sx25);
1362 	}
1363 
1364 	x25_check_rbuf(sk);
1365 	rc = copied;
1366 out_free_dgram:
1367 	skb_free_datagram(sk, skb);
1368 out:
1369 	release_sock(sk);
1370 	return rc;
1371 }
1372 
1373 
1374 static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1375 {
1376 	struct sock *sk = sock->sk;
1377 	struct x25_sock *x25 = x25_sk(sk);
1378 	void __user *argp = (void __user *)arg;
1379 	int rc;
1380 
1381 	switch (cmd) {
1382 	case TIOCOUTQ: {
1383 		int amount;
1384 
1385 		amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1386 		if (amount < 0)
1387 			amount = 0;
1388 		rc = put_user(amount, (unsigned int __user *)argp);
1389 		break;
1390 	}
1391 
1392 	case TIOCINQ: {
1393 		struct sk_buff *skb;
1394 		int amount = 0;
1395 		/*
1396 		 * These two are safe on a single CPU system as
1397 		 * only user tasks fiddle here
1398 		 */
1399 		lock_sock(sk);
1400 		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1401 			amount = skb->len;
1402 		release_sock(sk);
1403 		rc = put_user(amount, (unsigned int __user *)argp);
1404 		break;
1405 	}
1406 
1407 	case SIOCGIFADDR:
1408 	case SIOCSIFADDR:
1409 	case SIOCGIFDSTADDR:
1410 	case SIOCSIFDSTADDR:
1411 	case SIOCGIFBRDADDR:
1412 	case SIOCSIFBRDADDR:
1413 	case SIOCGIFNETMASK:
1414 	case SIOCSIFNETMASK:
1415 	case SIOCGIFMETRIC:
1416 	case SIOCSIFMETRIC:
1417 		rc = -EINVAL;
1418 		break;
1419 	case SIOCADDRT:
1420 	case SIOCDELRT:
1421 		rc = -EPERM;
1422 		if (!capable(CAP_NET_ADMIN))
1423 			break;
1424 		rc = x25_route_ioctl(cmd, argp);
1425 		break;
1426 	case SIOCX25GSUBSCRIP:
1427 		rc = x25_subscr_ioctl(cmd, argp);
1428 		break;
1429 	case SIOCX25SSUBSCRIP:
1430 		rc = -EPERM;
1431 		if (!capable(CAP_NET_ADMIN))
1432 			break;
1433 		rc = x25_subscr_ioctl(cmd, argp);
1434 		break;
1435 	case SIOCX25GFACILITIES: {
1436 		lock_sock(sk);
1437 		rc = copy_to_user(argp, &x25->facilities,
1438 				  sizeof(x25->facilities))
1439 			? -EFAULT : 0;
1440 		release_sock(sk);
1441 		break;
1442 	}
1443 
1444 	case SIOCX25SFACILITIES: {
1445 		struct x25_facilities facilities;
1446 		rc = -EFAULT;
1447 		if (copy_from_user(&facilities, argp, sizeof(facilities)))
1448 			break;
1449 		rc = -EINVAL;
1450 		lock_sock(sk);
1451 		if (sk->sk_state != TCP_LISTEN &&
1452 		    sk->sk_state != TCP_CLOSE)
1453 			goto out_fac_release;
1454 		if (facilities.pacsize_in < X25_PS16 ||
1455 		    facilities.pacsize_in > X25_PS4096)
1456 			goto out_fac_release;
1457 		if (facilities.pacsize_out < X25_PS16 ||
1458 		    facilities.pacsize_out > X25_PS4096)
1459 			goto out_fac_release;
1460 		if (facilities.winsize_in < 1 ||
1461 		    facilities.winsize_in > 127)
1462 			goto out_fac_release;
1463 		if (facilities.throughput) {
1464 			int out = facilities.throughput & 0xf0;
1465 			int in  = facilities.throughput & 0x0f;
1466 			if (!out)
1467 				facilities.throughput |=
1468 					X25_DEFAULT_THROUGHPUT << 4;
1469 			else if (out < 0x30 || out > 0xD0)
1470 				goto out_fac_release;
1471 			if (!in)
1472 				facilities.throughput |=
1473 					X25_DEFAULT_THROUGHPUT;
1474 			else if (in < 0x03 || in > 0x0D)
1475 				goto out_fac_release;
1476 		}
1477 		if (facilities.reverse &&
1478 		    (facilities.reverse & 0x81) != 0x81)
1479 			goto out_fac_release;
1480 		x25->facilities = facilities;
1481 		rc = 0;
1482 out_fac_release:
1483 		release_sock(sk);
1484 		break;
1485 	}
1486 
1487 	case SIOCX25GDTEFACILITIES: {
1488 		lock_sock(sk);
1489 		rc = copy_to_user(argp, &x25->dte_facilities,
1490 				  sizeof(x25->dte_facilities));
1491 		release_sock(sk);
1492 		if (rc)
1493 			rc = -EFAULT;
1494 		break;
1495 	}
1496 
1497 	case SIOCX25SDTEFACILITIES: {
1498 		struct x25_dte_facilities dtefacs;
1499 		rc = -EFAULT;
1500 		if (copy_from_user(&dtefacs, argp, sizeof(dtefacs)))
1501 			break;
1502 		rc = -EINVAL;
1503 		lock_sock(sk);
1504 		if (sk->sk_state != TCP_LISTEN &&
1505 		    sk->sk_state != TCP_CLOSE)
1506 			goto out_dtefac_release;
1507 		if (dtefacs.calling_len > X25_MAX_AE_LEN)
1508 			goto out_dtefac_release;
1509 		if (dtefacs.called_len > X25_MAX_AE_LEN)
1510 			goto out_dtefac_release;
1511 		x25->dte_facilities = dtefacs;
1512 		rc = 0;
1513 out_dtefac_release:
1514 		release_sock(sk);
1515 		break;
1516 	}
1517 
1518 	case SIOCX25GCALLUSERDATA: {
1519 		lock_sock(sk);
1520 		rc = copy_to_user(argp, &x25->calluserdata,
1521 				  sizeof(x25->calluserdata))
1522 			? -EFAULT : 0;
1523 		release_sock(sk);
1524 		break;
1525 	}
1526 
1527 	case SIOCX25SCALLUSERDATA: {
1528 		struct x25_calluserdata calluserdata;
1529 
1530 		rc = -EFAULT;
1531 		if (copy_from_user(&calluserdata, argp, sizeof(calluserdata)))
1532 			break;
1533 		rc = -EINVAL;
1534 		if (calluserdata.cudlength > X25_MAX_CUD_LEN)
1535 			break;
1536 		lock_sock(sk);
1537 		x25->calluserdata = calluserdata;
1538 		release_sock(sk);
1539 		rc = 0;
1540 		break;
1541 	}
1542 
1543 	case SIOCX25GCAUSEDIAG: {
1544 		lock_sock(sk);
1545 		rc = copy_to_user(argp, &x25->causediag, sizeof(x25->causediag))
1546 			? -EFAULT : 0;
1547 		release_sock(sk);
1548 		break;
1549 	}
1550 
1551 	case SIOCX25SCAUSEDIAG: {
1552 		struct x25_causediag causediag;
1553 		rc = -EFAULT;
1554 		if (copy_from_user(&causediag, argp, sizeof(causediag)))
1555 			break;
1556 		lock_sock(sk);
1557 		x25->causediag = causediag;
1558 		release_sock(sk);
1559 		rc = 0;
1560 		break;
1561 
1562 	}
1563 
1564 	case SIOCX25SCUDMATCHLEN: {
1565 		struct x25_subaddr sub_addr;
1566 		rc = -EINVAL;
1567 		lock_sock(sk);
1568 		if(sk->sk_state != TCP_CLOSE)
1569 			goto out_cud_release;
1570 		rc = -EFAULT;
1571 		if (copy_from_user(&sub_addr, argp,
1572 				   sizeof(sub_addr)))
1573 			goto out_cud_release;
1574 		rc = -EINVAL;
1575 		if (sub_addr.cudmatchlength > X25_MAX_CUD_LEN)
1576 			goto out_cud_release;
1577 		x25->cudmatchlength = sub_addr.cudmatchlength;
1578 		rc = 0;
1579 out_cud_release:
1580 		release_sock(sk);
1581 		break;
1582 	}
1583 
1584 	case SIOCX25CALLACCPTAPPRV: {
1585 		rc = -EINVAL;
1586 		lock_sock(sk);
1587 		if (sk->sk_state == TCP_CLOSE) {
1588 			clear_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);
1589 			rc = 0;
1590 		}
1591 		release_sock(sk);
1592 		break;
1593 	}
1594 
1595 	case SIOCX25SENDCALLACCPT:  {
1596 		rc = -EINVAL;
1597 		lock_sock(sk);
1598 		if (sk->sk_state != TCP_ESTABLISHED)
1599 			goto out_sendcallaccpt_release;
1600 		/* must call accptapprv above */
1601 		if (test_bit(X25_ACCPT_APPRV_FLAG, &x25->flags))
1602 			goto out_sendcallaccpt_release;
1603 		x25_write_internal(sk, X25_CALL_ACCEPTED);
1604 		x25->state = X25_STATE_3;
1605 		rc = 0;
1606 out_sendcallaccpt_release:
1607 		release_sock(sk);
1608 		break;
1609 	}
1610 
1611 	default:
1612 		rc = -ENOIOCTLCMD;
1613 		break;
1614 	}
1615 
1616 	return rc;
1617 }
1618 
1619 static const struct net_proto_family x25_family_ops = {
1620 	.family =	AF_X25,
1621 	.create =	x25_create,
1622 	.owner	=	THIS_MODULE,
1623 };
1624 
1625 #ifdef CONFIG_COMPAT
1626 static int compat_x25_subscr_ioctl(unsigned int cmd,
1627 		struct compat_x25_subscrip_struct __user *x25_subscr32)
1628 {
1629 	struct compat_x25_subscrip_struct x25_subscr;
1630 	struct x25_neigh *nb;
1631 	struct net_device *dev;
1632 	int rc = -EINVAL;
1633 
1634 	rc = -EFAULT;
1635 	if (copy_from_user(&x25_subscr, x25_subscr32, sizeof(*x25_subscr32)))
1636 		goto out;
1637 
1638 	rc = -EINVAL;
1639 	dev = x25_dev_get(x25_subscr.device);
1640 	if (dev == NULL)
1641 		goto out;
1642 
1643 	nb = x25_get_neigh(dev);
1644 	if (nb == NULL)
1645 		goto out_dev_put;
1646 
1647 	dev_put(dev);
1648 
1649 	if (cmd == SIOCX25GSUBSCRIP) {
1650 		read_lock_bh(&x25_neigh_list_lock);
1651 		x25_subscr.extended = nb->extended;
1652 		x25_subscr.global_facil_mask = nb->global_facil_mask;
1653 		read_unlock_bh(&x25_neigh_list_lock);
1654 		rc = copy_to_user(x25_subscr32, &x25_subscr,
1655 				sizeof(*x25_subscr32)) ? -EFAULT : 0;
1656 	} else {
1657 		rc = -EINVAL;
1658 		if (x25_subscr.extended == 0 || x25_subscr.extended == 1) {
1659 			rc = 0;
1660 			write_lock_bh(&x25_neigh_list_lock);
1661 			nb->extended = x25_subscr.extended;
1662 			nb->global_facil_mask = x25_subscr.global_facil_mask;
1663 			write_unlock_bh(&x25_neigh_list_lock);
1664 		}
1665 	}
1666 	x25_neigh_put(nb);
1667 out:
1668 	return rc;
1669 out_dev_put:
1670 	dev_put(dev);
1671 	goto out;
1672 }
1673 
1674 static int compat_x25_ioctl(struct socket *sock, unsigned int cmd,
1675 				unsigned long arg)
1676 {
1677 	void __user *argp = compat_ptr(arg);
1678 	int rc = -ENOIOCTLCMD;
1679 
1680 	switch(cmd) {
1681 	case TIOCOUTQ:
1682 	case TIOCINQ:
1683 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1684 		break;
1685 	case SIOCGIFADDR:
1686 	case SIOCSIFADDR:
1687 	case SIOCGIFDSTADDR:
1688 	case SIOCSIFDSTADDR:
1689 	case SIOCGIFBRDADDR:
1690 	case SIOCSIFBRDADDR:
1691 	case SIOCGIFNETMASK:
1692 	case SIOCSIFNETMASK:
1693 	case SIOCGIFMETRIC:
1694 	case SIOCSIFMETRIC:
1695 		rc = -EINVAL;
1696 		break;
1697 	case SIOCADDRT:
1698 	case SIOCDELRT:
1699 		rc = -EPERM;
1700 		if (!capable(CAP_NET_ADMIN))
1701 			break;
1702 		rc = x25_route_ioctl(cmd, argp);
1703 		break;
1704 	case SIOCX25GSUBSCRIP:
1705 		rc = compat_x25_subscr_ioctl(cmd, argp);
1706 		break;
1707 	case SIOCX25SSUBSCRIP:
1708 		rc = -EPERM;
1709 		if (!capable(CAP_NET_ADMIN))
1710 			break;
1711 		rc = compat_x25_subscr_ioctl(cmd, argp);
1712 		break;
1713 	case SIOCX25GFACILITIES:
1714 	case SIOCX25SFACILITIES:
1715 	case SIOCX25GDTEFACILITIES:
1716 	case SIOCX25SDTEFACILITIES:
1717 	case SIOCX25GCALLUSERDATA:
1718 	case SIOCX25SCALLUSERDATA:
1719 	case SIOCX25GCAUSEDIAG:
1720 	case SIOCX25SCAUSEDIAG:
1721 	case SIOCX25SCUDMATCHLEN:
1722 	case SIOCX25CALLACCPTAPPRV:
1723 	case SIOCX25SENDCALLACCPT:
1724 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1725 		break;
1726 	default:
1727 		rc = -ENOIOCTLCMD;
1728 		break;
1729 	}
1730 	return rc;
1731 }
1732 #endif
1733 
1734 static const struct proto_ops x25_proto_ops = {
1735 	.family =	AF_X25,
1736 	.owner =	THIS_MODULE,
1737 	.release =	x25_release,
1738 	.bind =		x25_bind,
1739 	.connect =	x25_connect,
1740 	.socketpair =	sock_no_socketpair,
1741 	.accept =	x25_accept,
1742 	.getname =	x25_getname,
1743 	.poll =		datagram_poll,
1744 	.ioctl =	x25_ioctl,
1745 #ifdef CONFIG_COMPAT
1746 	.compat_ioctl = compat_x25_ioctl,
1747 #endif
1748 	.gettstamp =	sock_gettstamp,
1749 	.listen =	x25_listen,
1750 	.shutdown =	sock_no_shutdown,
1751 	.setsockopt =	x25_setsockopt,
1752 	.getsockopt_iter = x25_getsockopt,
1753 	.sendmsg =	x25_sendmsg,
1754 	.recvmsg =	x25_recvmsg,
1755 	.mmap =		sock_no_mmap,
1756 };
1757 
1758 static struct packet_type x25_packet_type __read_mostly = {
1759 	.type =	cpu_to_be16(ETH_P_X25),
1760 	.func =	x25_lapb_receive_frame,
1761 };
1762 
1763 static struct notifier_block x25_dev_notifier = {
1764 	.notifier_call = x25_device_event,
1765 };
1766 
1767 void x25_kill_by_neigh(struct x25_neigh *nb)
1768 {
1769 	struct sock *s;
1770 
1771 	write_lock_bh(&x25_list_lock);
1772 
1773 	sk_for_each(s, &x25_list) {
1774 		if (x25_sk(s)->neighbour == nb) {
1775 			write_unlock_bh(&x25_list_lock);
1776 			lock_sock(s);
1777 			x25_disconnect(s, ENETUNREACH, 0, 0);
1778 			release_sock(s);
1779 			write_lock_bh(&x25_list_lock);
1780 		}
1781 	}
1782 	write_unlock_bh(&x25_list_lock);
1783 
1784 	/* Remove any related forwards */
1785 	x25_clear_forward_by_dev(nb->dev);
1786 }
1787 
1788 static int __init x25_init(void)
1789 {
1790 	int rc;
1791 
1792 	rc = proto_register(&x25_proto, 0);
1793 	if (rc)
1794 		goto out;
1795 
1796 	rc = sock_register(&x25_family_ops);
1797 	if (rc)
1798 		goto out_proto;
1799 
1800 	dev_add_pack(&x25_packet_type);
1801 
1802 	rc = register_netdevice_notifier(&x25_dev_notifier);
1803 	if (rc)
1804 		goto out_sock;
1805 
1806 	rc = x25_register_sysctl();
1807 	if (rc)
1808 		goto out_dev;
1809 
1810 	rc = x25_proc_init();
1811 	if (rc)
1812 		goto out_sysctl;
1813 
1814 	pr_info("Linux Version 0.2\n");
1815 
1816 out:
1817 	return rc;
1818 out_sysctl:
1819 	x25_unregister_sysctl();
1820 out_dev:
1821 	unregister_netdevice_notifier(&x25_dev_notifier);
1822 out_sock:
1823 	dev_remove_pack(&x25_packet_type);
1824 	sock_unregister(AF_X25);
1825 out_proto:
1826 	proto_unregister(&x25_proto);
1827 	goto out;
1828 }
1829 module_init(x25_init);
1830 
1831 static void __exit x25_exit(void)
1832 {
1833 	x25_proc_exit();
1834 	x25_link_free();
1835 	x25_route_free();
1836 
1837 	x25_unregister_sysctl();
1838 
1839 	unregister_netdevice_notifier(&x25_dev_notifier);
1840 
1841 	dev_remove_pack(&x25_packet_type);
1842 
1843 	sock_unregister(AF_X25);
1844 	proto_unregister(&x25_proto);
1845 }
1846 module_exit(x25_exit);
1847 
1848 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
1849 MODULE_DESCRIPTION("The X.25 Packet Layer network layer protocol");
1850 MODULE_LICENSE("GPL");
1851 MODULE_ALIAS_NETPROTO(PF_X25);
1852