xref: /openbmc/linux/net/x25/af_x25.c (revision fe0a5788)
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_UP:
237 			x25_link_device_up(dev);
238 			break;
239 		case NETDEV_GOING_DOWN:
240 			nb = x25_get_neigh(dev);
241 			if (nb) {
242 				x25_terminate_link(nb);
243 				x25_neigh_put(nb);
244 			}
245 			break;
246 		case NETDEV_DOWN:
247 			x25_kill_by_device(dev);
248 			x25_route_device_down(dev);
249 			x25_link_device_down(dev);
250 			break;
251 		}
252 	}
253 
254 	return NOTIFY_DONE;
255 }
256 
257 /*
258  *	Add a socket to the bound sockets list.
259  */
260 static void x25_insert_socket(struct sock *sk)
261 {
262 	write_lock_bh(&x25_list_lock);
263 	sk_add_node(sk, &x25_list);
264 	write_unlock_bh(&x25_list_lock);
265 }
266 
267 /*
268  *	Find a socket that wants to accept the Call Request we just
269  *	received. Check the full list for an address/cud match.
270  *	If no cuds match return the next_best thing, an address match.
271  *	Note: if a listening socket has cud set it must only get calls
272  *	with matching cud.
273  */
274 static struct sock *x25_find_listener(struct x25_address *addr,
275 					struct sk_buff *skb)
276 {
277 	struct sock *s;
278 	struct sock *next_best;
279 
280 	read_lock_bh(&x25_list_lock);
281 	next_best = NULL;
282 
283 	sk_for_each(s, &x25_list)
284 		if ((!strcmp(addr->x25_addr,
285 			x25_sk(s)->source_addr.x25_addr) ||
286 				!strcmp(x25_sk(s)->source_addr.x25_addr,
287 					null_x25_address.x25_addr)) &&
288 					s->sk_state == TCP_LISTEN) {
289 			/*
290 			 * Found a listening socket, now check the incoming
291 			 * call user data vs this sockets call user data
292 			 */
293 			if (x25_sk(s)->cudmatchlength > 0 &&
294 				skb->len >= x25_sk(s)->cudmatchlength) {
295 				if((memcmp(x25_sk(s)->calluserdata.cuddata,
296 					skb->data,
297 					x25_sk(s)->cudmatchlength)) == 0) {
298 					sock_hold(s);
299 					goto found;
300 				 }
301 			} else
302 				next_best = s;
303 		}
304 	if (next_best) {
305 		s = next_best;
306 		sock_hold(s);
307 		goto found;
308 	}
309 	s = NULL;
310 found:
311 	read_unlock_bh(&x25_list_lock);
312 	return s;
313 }
314 
315 /*
316  *	Find a connected X.25 socket given my LCI and neighbour.
317  */
318 static struct sock *__x25_find_socket(unsigned int lci, struct x25_neigh *nb)
319 {
320 	struct sock *s;
321 
322 	sk_for_each(s, &x25_list)
323 		if (x25_sk(s)->lci == lci && x25_sk(s)->neighbour == nb) {
324 			sock_hold(s);
325 			goto found;
326 		}
327 	s = NULL;
328 found:
329 	return s;
330 }
331 
332 struct sock *x25_find_socket(unsigned int lci, struct x25_neigh *nb)
333 {
334 	struct sock *s;
335 
336 	read_lock_bh(&x25_list_lock);
337 	s = __x25_find_socket(lci, nb);
338 	read_unlock_bh(&x25_list_lock);
339 	return s;
340 }
341 
342 /*
343  *	Find a unique LCI for a given device.
344  */
345 static unsigned int x25_new_lci(struct x25_neigh *nb)
346 {
347 	unsigned int lci = 1;
348 	struct sock *sk;
349 
350 	while ((sk = x25_find_socket(lci, nb)) != NULL) {
351 		sock_put(sk);
352 		if (++lci == 4096) {
353 			lci = 0;
354 			break;
355 		}
356 		cond_resched();
357 	}
358 
359 	return lci;
360 }
361 
362 /*
363  *	Deferred destroy.
364  */
365 static void __x25_destroy_socket(struct sock *);
366 
367 /*
368  *	handler for deferred kills.
369  */
370 static void x25_destroy_timer(struct timer_list *t)
371 {
372 	struct sock *sk = from_timer(sk, t, sk_timer);
373 
374 	x25_destroy_socket_from_timer(sk);
375 }
376 
377 /*
378  *	This is called from user mode and the timers. Thus it protects itself
379  *	against interrupt users but doesn't worry about being called during
380  *	work. Once it is removed from the queue no interrupt or bottom half
381  *	will touch it and we are (fairly 8-) ) safe.
382  *	Not static as it's used by the timer
383  */
384 static void __x25_destroy_socket(struct sock *sk)
385 {
386 	struct sk_buff *skb;
387 
388 	x25_stop_heartbeat(sk);
389 	x25_stop_timer(sk);
390 
391 	x25_remove_socket(sk);
392 	x25_clear_queues(sk);		/* Flush the queues */
393 
394 	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
395 		if (skb->sk != sk) {		/* A pending connection */
396 			/*
397 			 * Queue the unaccepted socket for death
398 			 */
399 			skb->sk->sk_state = TCP_LISTEN;
400 			sock_set_flag(skb->sk, SOCK_DEAD);
401 			x25_start_heartbeat(skb->sk);
402 			x25_sk(skb->sk)->state = X25_STATE_0;
403 		}
404 
405 		kfree_skb(skb);
406 	}
407 
408 	if (sk_has_allocations(sk)) {
409 		/* Defer: outstanding buffers */
410 		sk->sk_timer.expires  = jiffies + 10 * HZ;
411 		sk->sk_timer.function = x25_destroy_timer;
412 		add_timer(&sk->sk_timer);
413 	} else {
414 		/* drop last reference so sock_put will free */
415 		__sock_put(sk);
416 	}
417 }
418 
419 void x25_destroy_socket_from_timer(struct sock *sk)
420 {
421 	sock_hold(sk);
422 	bh_lock_sock(sk);
423 	__x25_destroy_socket(sk);
424 	bh_unlock_sock(sk);
425 	sock_put(sk);
426 }
427 
428 /*
429  *	Handling for system calls applied via the various interfaces to a
430  *	X.25 socket object.
431  */
432 
433 static int x25_setsockopt(struct socket *sock, int level, int optname,
434 			  sockptr_t optval, unsigned int optlen)
435 {
436 	int opt;
437 	struct sock *sk = sock->sk;
438 	int rc = -ENOPROTOOPT;
439 
440 	if (level != SOL_X25 || optname != X25_QBITINCL)
441 		goto out;
442 
443 	rc = -EINVAL;
444 	if (optlen < sizeof(int))
445 		goto out;
446 
447 	rc = -EFAULT;
448 	if (copy_from_sockptr(&opt, optval, sizeof(int)))
449 		goto out;
450 
451 	if (opt)
452 		set_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
453 	else
454 		clear_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
455 	rc = 0;
456 out:
457 	return rc;
458 }
459 
460 static int x25_getsockopt(struct socket *sock, int level, int optname,
461 			  char __user *optval, int __user *optlen)
462 {
463 	struct sock *sk = sock->sk;
464 	int val, len, rc = -ENOPROTOOPT;
465 
466 	if (level != SOL_X25 || optname != X25_QBITINCL)
467 		goto out;
468 
469 	rc = -EFAULT;
470 	if (get_user(len, optlen))
471 		goto out;
472 
473 	len = min_t(unsigned int, len, sizeof(int));
474 
475 	rc = -EINVAL;
476 	if (len < 0)
477 		goto out;
478 
479 	rc = -EFAULT;
480 	if (put_user(len, optlen))
481 		goto out;
482 
483 	val = test_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
484 	rc = copy_to_user(optval, &val, len) ? -EFAULT : 0;
485 out:
486 	return rc;
487 }
488 
489 static int x25_listen(struct socket *sock, int backlog)
490 {
491 	struct sock *sk = sock->sk;
492 	int rc = -EOPNOTSUPP;
493 
494 	lock_sock(sk);
495 	if (sk->sk_state != TCP_LISTEN) {
496 		memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN);
497 		sk->sk_max_ack_backlog = backlog;
498 		sk->sk_state           = TCP_LISTEN;
499 		rc = 0;
500 	}
501 	release_sock(sk);
502 
503 	return rc;
504 }
505 
506 static struct proto x25_proto = {
507 	.name	  = "X25",
508 	.owner	  = THIS_MODULE,
509 	.obj_size = sizeof(struct x25_sock),
510 };
511 
512 static struct sock *x25_alloc_socket(struct net *net, int kern)
513 {
514 	struct x25_sock *x25;
515 	struct sock *sk = sk_alloc(net, AF_X25, GFP_ATOMIC, &x25_proto, kern);
516 
517 	if (!sk)
518 		goto out;
519 
520 	sock_init_data(NULL, sk);
521 
522 	x25 = x25_sk(sk);
523 	skb_queue_head_init(&x25->ack_queue);
524 	skb_queue_head_init(&x25->fragment_queue);
525 	skb_queue_head_init(&x25->interrupt_in_queue);
526 	skb_queue_head_init(&x25->interrupt_out_queue);
527 out:
528 	return sk;
529 }
530 
531 static int x25_create(struct net *net, struct socket *sock, int protocol,
532 		      int kern)
533 {
534 	struct sock *sk;
535 	struct x25_sock *x25;
536 	int rc = -EAFNOSUPPORT;
537 
538 	if (!net_eq(net, &init_net))
539 		goto out;
540 
541 	rc = -ESOCKTNOSUPPORT;
542 	if (sock->type != SOCK_SEQPACKET)
543 		goto out;
544 
545 	rc = -EINVAL;
546 	if (protocol)
547 		goto out;
548 
549 	rc = -ENOBUFS;
550 	if ((sk = x25_alloc_socket(net, kern)) == NULL)
551 		goto out;
552 
553 	x25 = x25_sk(sk);
554 
555 	sock_init_data(sock, sk);
556 
557 	x25_init_timers(sk);
558 
559 	sock->ops    = &x25_proto_ops;
560 	sk->sk_protocol = protocol;
561 	sk->sk_backlog_rcv = x25_backlog_rcv;
562 
563 	x25->t21   = sysctl_x25_call_request_timeout;
564 	x25->t22   = sysctl_x25_reset_request_timeout;
565 	x25->t23   = sysctl_x25_clear_request_timeout;
566 	x25->t2    = sysctl_x25_ack_holdback_timeout;
567 	x25->state = X25_STATE_0;
568 	x25->cudmatchlength = 0;
569 	set_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);	/* normally no cud  */
570 							/* on call accept   */
571 
572 	x25->facilities.winsize_in  = X25_DEFAULT_WINDOW_SIZE;
573 	x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
574 	x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
575 	x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
576 	x25->facilities.throughput  = 0;	/* by default don't negotiate
577 						   throughput */
578 	x25->facilities.reverse     = X25_DEFAULT_REVERSE;
579 	x25->dte_facilities.calling_len = 0;
580 	x25->dte_facilities.called_len = 0;
581 	memset(x25->dte_facilities.called_ae, '\0',
582 			sizeof(x25->dte_facilities.called_ae));
583 	memset(x25->dte_facilities.calling_ae, '\0',
584 			sizeof(x25->dte_facilities.calling_ae));
585 
586 	rc = 0;
587 out:
588 	return rc;
589 }
590 
591 static struct sock *x25_make_new(struct sock *osk)
592 {
593 	struct sock *sk = NULL;
594 	struct x25_sock *x25, *ox25;
595 
596 	if (osk->sk_type != SOCK_SEQPACKET)
597 		goto out;
598 
599 	if ((sk = x25_alloc_socket(sock_net(osk), 0)) == NULL)
600 		goto out;
601 
602 	x25 = x25_sk(sk);
603 
604 	sk->sk_type        = osk->sk_type;
605 	sk->sk_priority    = osk->sk_priority;
606 	sk->sk_protocol    = osk->sk_protocol;
607 	sk->sk_rcvbuf      = osk->sk_rcvbuf;
608 	sk->sk_sndbuf      = osk->sk_sndbuf;
609 	sk->sk_state       = TCP_ESTABLISHED;
610 	sk->sk_backlog_rcv = osk->sk_backlog_rcv;
611 	sock_copy_flags(sk, osk);
612 
613 	ox25 = x25_sk(osk);
614 	x25->t21        = ox25->t21;
615 	x25->t22        = ox25->t22;
616 	x25->t23        = ox25->t23;
617 	x25->t2         = ox25->t2;
618 	x25->flags	= ox25->flags;
619 	x25->facilities = ox25->facilities;
620 	x25->dte_facilities = ox25->dte_facilities;
621 	x25->cudmatchlength = ox25->cudmatchlength;
622 
623 	clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
624 	x25_init_timers(sk);
625 out:
626 	return sk;
627 }
628 
629 static int x25_release(struct socket *sock)
630 {
631 	struct sock *sk = sock->sk;
632 	struct x25_sock *x25;
633 
634 	if (!sk)
635 		return 0;
636 
637 	x25 = x25_sk(sk);
638 
639 	sock_hold(sk);
640 	lock_sock(sk);
641 	switch (x25->state) {
642 
643 		case X25_STATE_0:
644 		case X25_STATE_2:
645 			x25_disconnect(sk, 0, 0, 0);
646 			__x25_destroy_socket(sk);
647 			goto out;
648 
649 		case X25_STATE_1:
650 		case X25_STATE_3:
651 		case X25_STATE_4:
652 			x25_clear_queues(sk);
653 			x25_write_internal(sk, X25_CLEAR_REQUEST);
654 			x25_start_t23timer(sk);
655 			x25->state = X25_STATE_2;
656 			sk->sk_state	= TCP_CLOSE;
657 			sk->sk_shutdown	|= SEND_SHUTDOWN;
658 			sk->sk_state_change(sk);
659 			sock_set_flag(sk, SOCK_DEAD);
660 			sock_set_flag(sk, SOCK_DESTROY);
661 			break;
662 
663 		case X25_STATE_5:
664 			x25_write_internal(sk, X25_CLEAR_REQUEST);
665 			x25_disconnect(sk, 0, 0, 0);
666 			__x25_destroy_socket(sk);
667 			goto out;
668 	}
669 
670 	sock_orphan(sk);
671 out:
672 	release_sock(sk);
673 	sock_put(sk);
674 	return 0;
675 }
676 
677 static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
678 {
679 	struct sock *sk = sock->sk;
680 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
681 	int len, i, rc = 0;
682 
683 	if (addr_len != sizeof(struct sockaddr_x25) ||
684 	    addr->sx25_family != AF_X25) {
685 		rc = -EINVAL;
686 		goto out;
687 	}
688 
689 	/* check for the null_x25_address */
690 	if (strcmp(addr->sx25_addr.x25_addr, null_x25_address.x25_addr)) {
691 
692 		len = strlen(addr->sx25_addr.x25_addr);
693 		for (i = 0; i < len; i++) {
694 			if (!isdigit(addr->sx25_addr.x25_addr[i])) {
695 				rc = -EINVAL;
696 				goto out;
697 			}
698 		}
699 	}
700 
701 	lock_sock(sk);
702 	if (sock_flag(sk, SOCK_ZAPPED)) {
703 		x25_sk(sk)->source_addr = addr->sx25_addr;
704 		x25_insert_socket(sk);
705 		sock_reset_flag(sk, SOCK_ZAPPED);
706 	} else {
707 		rc = -EINVAL;
708 	}
709 	release_sock(sk);
710 	SOCK_DEBUG(sk, "x25_bind: socket is bound\n");
711 out:
712 	return rc;
713 }
714 
715 static int x25_wait_for_connection_establishment(struct sock *sk)
716 {
717 	DECLARE_WAITQUEUE(wait, current);
718 	int rc;
719 
720 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
721 	for (;;) {
722 		__set_current_state(TASK_INTERRUPTIBLE);
723 		rc = -ERESTARTSYS;
724 		if (signal_pending(current))
725 			break;
726 		rc = sock_error(sk);
727 		if (rc) {
728 			sk->sk_socket->state = SS_UNCONNECTED;
729 			break;
730 		}
731 		rc = 0;
732 		if (sk->sk_state != TCP_ESTABLISHED) {
733 			release_sock(sk);
734 			schedule();
735 			lock_sock(sk);
736 		} else
737 			break;
738 	}
739 	__set_current_state(TASK_RUNNING);
740 	remove_wait_queue(sk_sleep(sk), &wait);
741 	return rc;
742 }
743 
744 static int x25_connect(struct socket *sock, struct sockaddr *uaddr,
745 		       int addr_len, int flags)
746 {
747 	struct sock *sk = sock->sk;
748 	struct x25_sock *x25 = x25_sk(sk);
749 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
750 	struct x25_route *rt;
751 	int rc = 0;
752 
753 	lock_sock(sk);
754 	if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
755 		sock->state = SS_CONNECTED;
756 		goto out; /* Connect completed during a ERESTARTSYS event */
757 	}
758 
759 	rc = -ECONNREFUSED;
760 	if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
761 		sock->state = SS_UNCONNECTED;
762 		goto out;
763 	}
764 
765 	rc = -EISCONN;	/* No reconnect on a seqpacket socket */
766 	if (sk->sk_state == TCP_ESTABLISHED)
767 		goto out;
768 
769 	rc = -EALREADY;	/* Do nothing if call is already in progress */
770 	if (sk->sk_state == TCP_SYN_SENT)
771 		goto out;
772 
773 	sk->sk_state   = TCP_CLOSE;
774 	sock->state = SS_UNCONNECTED;
775 
776 	rc = -EINVAL;
777 	if (addr_len != sizeof(struct sockaddr_x25) ||
778 	    addr->sx25_family != AF_X25)
779 		goto out;
780 
781 	rc = -ENETUNREACH;
782 	rt = x25_get_route(&addr->sx25_addr);
783 	if (!rt)
784 		goto out;
785 
786 	x25->neighbour = x25_get_neigh(rt->dev);
787 	if (!x25->neighbour)
788 		goto out_put_route;
789 
790 	x25_limit_facilities(&x25->facilities, x25->neighbour);
791 
792 	x25->lci = x25_new_lci(x25->neighbour);
793 	if (!x25->lci)
794 		goto out_put_neigh;
795 
796 	rc = -EINVAL;
797 	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
798 		goto out_put_neigh;
799 
800 	if (!strcmp(x25->source_addr.x25_addr, null_x25_address.x25_addr))
801 		memset(&x25->source_addr, '\0', X25_ADDR_LEN);
802 
803 	x25->dest_addr = addr->sx25_addr;
804 
805 	/* Move to connecting socket, start sending Connect Requests */
806 	sock->state   = SS_CONNECTING;
807 	sk->sk_state  = TCP_SYN_SENT;
808 
809 	x25->state = X25_STATE_1;
810 
811 	x25_write_internal(sk, X25_CALL_REQUEST);
812 
813 	x25_start_heartbeat(sk);
814 	x25_start_t21timer(sk);
815 
816 	/* Now the loop */
817 	rc = -EINPROGRESS;
818 	if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK))
819 		goto out;
820 
821 	rc = x25_wait_for_connection_establishment(sk);
822 	if (rc)
823 		goto out_put_neigh;
824 
825 	sock->state = SS_CONNECTED;
826 	rc = 0;
827 out_put_neigh:
828 	if (rc) {
829 		read_lock_bh(&x25_list_lock);
830 		x25_neigh_put(x25->neighbour);
831 		x25->neighbour = NULL;
832 		read_unlock_bh(&x25_list_lock);
833 		x25->state = X25_STATE_0;
834 	}
835 out_put_route:
836 	x25_route_put(rt);
837 out:
838 	release_sock(sk);
839 	return rc;
840 }
841 
842 static int x25_wait_for_data(struct sock *sk, long timeout)
843 {
844 	DECLARE_WAITQUEUE(wait, current);
845 	int rc = 0;
846 
847 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
848 	for (;;) {
849 		__set_current_state(TASK_INTERRUPTIBLE);
850 		if (sk->sk_shutdown & RCV_SHUTDOWN)
851 			break;
852 		rc = -ERESTARTSYS;
853 		if (signal_pending(current))
854 			break;
855 		rc = -EAGAIN;
856 		if (!timeout)
857 			break;
858 		rc = 0;
859 		if (skb_queue_empty(&sk->sk_receive_queue)) {
860 			release_sock(sk);
861 			timeout = schedule_timeout(timeout);
862 			lock_sock(sk);
863 		} else
864 			break;
865 	}
866 	__set_current_state(TASK_RUNNING);
867 	remove_wait_queue(sk_sleep(sk), &wait);
868 	return rc;
869 }
870 
871 static int x25_accept(struct socket *sock, struct socket *newsock, int flags,
872 		      bool kern)
873 {
874 	struct sock *sk = sock->sk;
875 	struct sock *newsk;
876 	struct sk_buff *skb;
877 	int rc = -EINVAL;
878 
879 	if (!sk)
880 		goto out;
881 
882 	rc = -EOPNOTSUPP;
883 	if (sk->sk_type != SOCK_SEQPACKET)
884 		goto out;
885 
886 	lock_sock(sk);
887 	rc = -EINVAL;
888 	if (sk->sk_state != TCP_LISTEN)
889 		goto out2;
890 
891 	rc = x25_wait_for_data(sk, sk->sk_rcvtimeo);
892 	if (rc)
893 		goto out2;
894 	skb = skb_dequeue(&sk->sk_receive_queue);
895 	rc = -EINVAL;
896 	if (!skb->sk)
897 		goto out2;
898 	newsk		 = skb->sk;
899 	sock_graft(newsk, newsock);
900 
901 	/* Now attach up the new socket */
902 	skb->sk = NULL;
903 	kfree_skb(skb);
904 	sk_acceptq_removed(sk);
905 	newsock->state = SS_CONNECTED;
906 	rc = 0;
907 out2:
908 	release_sock(sk);
909 out:
910 	return rc;
911 }
912 
913 static int x25_getname(struct socket *sock, struct sockaddr *uaddr,
914 		       int peer)
915 {
916 	struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)uaddr;
917 	struct sock *sk = sock->sk;
918 	struct x25_sock *x25 = x25_sk(sk);
919 	int rc = 0;
920 
921 	if (peer) {
922 		if (sk->sk_state != TCP_ESTABLISHED) {
923 			rc = -ENOTCONN;
924 			goto out;
925 		}
926 		sx25->sx25_addr = x25->dest_addr;
927 	} else
928 		sx25->sx25_addr = x25->source_addr;
929 
930 	sx25->sx25_family = AF_X25;
931 	rc = sizeof(*sx25);
932 
933 out:
934 	return rc;
935 }
936 
937 int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
938 			unsigned int lci)
939 {
940 	struct sock *sk;
941 	struct sock *make;
942 	struct x25_sock *makex25;
943 	struct x25_address source_addr, dest_addr;
944 	struct x25_facilities facilities;
945 	struct x25_dte_facilities dte_facilities;
946 	int len, addr_len, rc;
947 
948 	/*
949 	 *	Remove the LCI and frame type.
950 	 */
951 	skb_pull(skb, X25_STD_MIN_LEN);
952 
953 	/*
954 	 *	Extract the X.25 addresses and convert them to ASCII strings,
955 	 *	and remove them.
956 	 *
957 	 *	Address block is mandatory in call request packets
958 	 */
959 	addr_len = x25_parse_address_block(skb, &source_addr, &dest_addr);
960 	if (addr_len <= 0)
961 		goto out_clear_request;
962 	skb_pull(skb, addr_len);
963 
964 	/*
965 	 *	Get the length of the facilities, skip past them for the moment
966 	 *	get the call user data because this is needed to determine
967 	 *	the correct listener
968 	 *
969 	 *	Facilities length is mandatory in call request packets
970 	 */
971 	if (!pskb_may_pull(skb, 1))
972 		goto out_clear_request;
973 	len = skb->data[0] + 1;
974 	if (!pskb_may_pull(skb, len))
975 		goto out_clear_request;
976 	skb_pull(skb,len);
977 
978 	/*
979 	 *	Ensure that the amount of call user data is valid.
980 	 */
981 	if (skb->len > X25_MAX_CUD_LEN)
982 		goto out_clear_request;
983 
984 	/*
985 	 *	Get all the call user data so it can be used in
986 	 *	x25_find_listener and skb_copy_from_linear_data up ahead.
987 	 */
988 	if (!pskb_may_pull(skb, skb->len))
989 		goto out_clear_request;
990 
991 	/*
992 	 *	Find a listener for the particular address/cud pair.
993 	 */
994 	sk = x25_find_listener(&source_addr,skb);
995 	skb_push(skb,len);
996 
997 	if (sk != NULL && sk_acceptq_is_full(sk)) {
998 		goto out_sock_put;
999 	}
1000 
1001 	/*
1002 	 *	We dont have any listeners for this incoming call.
1003 	 *	Try forwarding it.
1004 	 */
1005 	if (sk == NULL) {
1006 		skb_push(skb, addr_len + X25_STD_MIN_LEN);
1007 		if (sysctl_x25_forward &&
1008 				x25_forward_call(&dest_addr, nb, skb, lci) > 0)
1009 		{
1010 			/* Call was forwarded, dont process it any more */
1011 			kfree_skb(skb);
1012 			rc = 1;
1013 			goto out;
1014 		} else {
1015 			/* No listeners, can't forward, clear the call */
1016 			goto out_clear_request;
1017 		}
1018 	}
1019 
1020 	/*
1021 	 *	Try to reach a compromise on the requested facilities.
1022 	 */
1023 	len = x25_negotiate_facilities(skb, sk, &facilities, &dte_facilities);
1024 	if (len == -1)
1025 		goto out_sock_put;
1026 
1027 	/*
1028 	 * current neighbour/link might impose additional limits
1029 	 * on certain facilties
1030 	 */
1031 
1032 	x25_limit_facilities(&facilities, nb);
1033 
1034 	/*
1035 	 *	Try to create a new socket.
1036 	 */
1037 	make = x25_make_new(sk);
1038 	if (!make)
1039 		goto out_sock_put;
1040 
1041 	/*
1042 	 *	Remove the facilities
1043 	 */
1044 	skb_pull(skb, len);
1045 
1046 	skb->sk     = make;
1047 	make->sk_state = TCP_ESTABLISHED;
1048 
1049 	makex25 = x25_sk(make);
1050 	makex25->lci           = lci;
1051 	makex25->dest_addr     = dest_addr;
1052 	makex25->source_addr   = source_addr;
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 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: Addresses built.\n");
1165 
1166 	/* Build a packet */
1167 	SOCK_DEBUG(sk, "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 	SOCK_DEBUG(sk, "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 	SOCK_DEBUG(sk, "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 	SOCK_DEBUG(sk, "x25_sendmsg: Built header.\n");
1245 	SOCK_DEBUG(sk, "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 & ~MSG_DONTWAIT,
1326 					flags & MSG_DONTWAIT, &rc);
1327 		lock_sock(sk);
1328 		if (!skb)
1329 			goto out;
1330 
1331 		if (!pskb_may_pull(skb, header_len))
1332 			goto out_free_dgram;
1333 
1334 		qbit = (skb->data[0] & X25_Q_BIT) == X25_Q_BIT;
1335 
1336 		skb_pull(skb, header_len);
1337 
1338 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1339 			asmptr  = skb_push(skb, 1);
1340 			*asmptr = qbit;
1341 		}
1342 	}
1343 
1344 	skb_reset_transport_header(skb);
1345 	copied = skb->len;
1346 
1347 	if (copied > size) {
1348 		copied = size;
1349 		msg->msg_flags |= MSG_TRUNC;
1350 	}
1351 
1352 	/* Currently, each datagram always contains a complete record */
1353 	msg->msg_flags |= MSG_EOR;
1354 
1355 	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
1356 	if (rc)
1357 		goto out_free_dgram;
1358 
1359 	if (sx25) {
1360 		sx25->sx25_family = AF_X25;
1361 		sx25->sx25_addr   = x25->dest_addr;
1362 		msg->msg_namelen = sizeof(*sx25);
1363 	}
1364 
1365 	x25_check_rbuf(sk);
1366 	rc = copied;
1367 out_free_dgram:
1368 	skb_free_datagram(sk, skb);
1369 out:
1370 	release_sock(sk);
1371 	return rc;
1372 }
1373 
1374 
1375 static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1376 {
1377 	struct sock *sk = sock->sk;
1378 	struct x25_sock *x25 = x25_sk(sk);
1379 	void __user *argp = (void __user *)arg;
1380 	int rc;
1381 
1382 	switch (cmd) {
1383 	case TIOCOUTQ: {
1384 		int amount;
1385 
1386 		amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1387 		if (amount < 0)
1388 			amount = 0;
1389 		rc = put_user(amount, (unsigned int __user *)argp);
1390 		break;
1391 	}
1392 
1393 	case TIOCINQ: {
1394 		struct sk_buff *skb;
1395 		int amount = 0;
1396 		/*
1397 		 * These two are safe on a single CPU system as
1398 		 * only user tasks fiddle here
1399 		 */
1400 		lock_sock(sk);
1401 		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1402 			amount = skb->len;
1403 		release_sock(sk);
1404 		rc = put_user(amount, (unsigned int __user *)argp);
1405 		break;
1406 	}
1407 
1408 	case SIOCGIFADDR:
1409 	case SIOCSIFADDR:
1410 	case SIOCGIFDSTADDR:
1411 	case SIOCSIFDSTADDR:
1412 	case SIOCGIFBRDADDR:
1413 	case SIOCSIFBRDADDR:
1414 	case SIOCGIFNETMASK:
1415 	case SIOCSIFNETMASK:
1416 	case SIOCGIFMETRIC:
1417 	case SIOCSIFMETRIC:
1418 		rc = -EINVAL;
1419 		break;
1420 	case SIOCADDRT:
1421 	case SIOCDELRT:
1422 		rc = -EPERM;
1423 		if (!capable(CAP_NET_ADMIN))
1424 			break;
1425 		rc = x25_route_ioctl(cmd, argp);
1426 		break;
1427 	case SIOCX25GSUBSCRIP:
1428 		rc = x25_subscr_ioctl(cmd, argp);
1429 		break;
1430 	case SIOCX25SSUBSCRIP:
1431 		rc = -EPERM;
1432 		if (!capable(CAP_NET_ADMIN))
1433 			break;
1434 		rc = x25_subscr_ioctl(cmd, argp);
1435 		break;
1436 	case SIOCX25GFACILITIES: {
1437 		lock_sock(sk);
1438 		rc = copy_to_user(argp, &x25->facilities,
1439 				  sizeof(x25->facilities))
1440 			? -EFAULT : 0;
1441 		release_sock(sk);
1442 		break;
1443 	}
1444 
1445 	case SIOCX25SFACILITIES: {
1446 		struct x25_facilities facilities;
1447 		rc = -EFAULT;
1448 		if (copy_from_user(&facilities, argp, sizeof(facilities)))
1449 			break;
1450 		rc = -EINVAL;
1451 		lock_sock(sk);
1452 		if (sk->sk_state != TCP_LISTEN &&
1453 		    sk->sk_state != TCP_CLOSE)
1454 			goto out_fac_release;
1455 		if (facilities.pacsize_in < X25_PS16 ||
1456 		    facilities.pacsize_in > X25_PS4096)
1457 			goto out_fac_release;
1458 		if (facilities.pacsize_out < X25_PS16 ||
1459 		    facilities.pacsize_out > X25_PS4096)
1460 			goto out_fac_release;
1461 		if (facilities.winsize_in < 1 ||
1462 		    facilities.winsize_in > 127)
1463 			goto out_fac_release;
1464 		if (facilities.throughput) {
1465 			int out = facilities.throughput & 0xf0;
1466 			int in  = facilities.throughput & 0x0f;
1467 			if (!out)
1468 				facilities.throughput |=
1469 					X25_DEFAULT_THROUGHPUT << 4;
1470 			else if (out < 0x30 || out > 0xD0)
1471 				goto out_fac_release;
1472 			if (!in)
1473 				facilities.throughput |=
1474 					X25_DEFAULT_THROUGHPUT;
1475 			else if (in < 0x03 || in > 0x0D)
1476 				goto out_fac_release;
1477 		}
1478 		if (facilities.reverse &&
1479 		    (facilities.reverse & 0x81) != 0x81)
1480 			goto out_fac_release;
1481 		x25->facilities = facilities;
1482 		rc = 0;
1483 out_fac_release:
1484 		release_sock(sk);
1485 		break;
1486 	}
1487 
1488 	case SIOCX25GDTEFACILITIES: {
1489 		lock_sock(sk);
1490 		rc = copy_to_user(argp, &x25->dte_facilities,
1491 				  sizeof(x25->dte_facilities));
1492 		release_sock(sk);
1493 		if (rc)
1494 			rc = -EFAULT;
1495 		break;
1496 	}
1497 
1498 	case SIOCX25SDTEFACILITIES: {
1499 		struct x25_dte_facilities dtefacs;
1500 		rc = -EFAULT;
1501 		if (copy_from_user(&dtefacs, argp, sizeof(dtefacs)))
1502 			break;
1503 		rc = -EINVAL;
1504 		lock_sock(sk);
1505 		if (sk->sk_state != TCP_LISTEN &&
1506 		    sk->sk_state != TCP_CLOSE)
1507 			goto out_dtefac_release;
1508 		if (dtefacs.calling_len > X25_MAX_AE_LEN)
1509 			goto out_dtefac_release;
1510 		if (dtefacs.called_len > X25_MAX_AE_LEN)
1511 			goto out_dtefac_release;
1512 		x25->dte_facilities = dtefacs;
1513 		rc = 0;
1514 out_dtefac_release:
1515 		release_sock(sk);
1516 		break;
1517 	}
1518 
1519 	case SIOCX25GCALLUSERDATA: {
1520 		lock_sock(sk);
1521 		rc = copy_to_user(argp, &x25->calluserdata,
1522 				  sizeof(x25->calluserdata))
1523 			? -EFAULT : 0;
1524 		release_sock(sk);
1525 		break;
1526 	}
1527 
1528 	case SIOCX25SCALLUSERDATA: {
1529 		struct x25_calluserdata calluserdata;
1530 
1531 		rc = -EFAULT;
1532 		if (copy_from_user(&calluserdata, argp, sizeof(calluserdata)))
1533 			break;
1534 		rc = -EINVAL;
1535 		if (calluserdata.cudlength > X25_MAX_CUD_LEN)
1536 			break;
1537 		lock_sock(sk);
1538 		x25->calluserdata = calluserdata;
1539 		release_sock(sk);
1540 		rc = 0;
1541 		break;
1542 	}
1543 
1544 	case SIOCX25GCAUSEDIAG: {
1545 		lock_sock(sk);
1546 		rc = copy_to_user(argp, &x25->causediag, sizeof(x25->causediag))
1547 			? -EFAULT : 0;
1548 		release_sock(sk);
1549 		break;
1550 	}
1551 
1552 	case SIOCX25SCAUSEDIAG: {
1553 		struct x25_causediag causediag;
1554 		rc = -EFAULT;
1555 		if (copy_from_user(&causediag, argp, sizeof(causediag)))
1556 			break;
1557 		lock_sock(sk);
1558 		x25->causediag = causediag;
1559 		release_sock(sk);
1560 		rc = 0;
1561 		break;
1562 
1563 	}
1564 
1565 	case SIOCX25SCUDMATCHLEN: {
1566 		struct x25_subaddr sub_addr;
1567 		rc = -EINVAL;
1568 		lock_sock(sk);
1569 		if(sk->sk_state != TCP_CLOSE)
1570 			goto out_cud_release;
1571 		rc = -EFAULT;
1572 		if (copy_from_user(&sub_addr, argp,
1573 				   sizeof(sub_addr)))
1574 			goto out_cud_release;
1575 		rc = -EINVAL;
1576 		if (sub_addr.cudmatchlength > X25_MAX_CUD_LEN)
1577 			goto out_cud_release;
1578 		x25->cudmatchlength = sub_addr.cudmatchlength;
1579 		rc = 0;
1580 out_cud_release:
1581 		release_sock(sk);
1582 		break;
1583 	}
1584 
1585 	case SIOCX25CALLACCPTAPPRV: {
1586 		rc = -EINVAL;
1587 		lock_sock(sk);
1588 		if (sk->sk_state == TCP_CLOSE) {
1589 			clear_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);
1590 			rc = 0;
1591 		}
1592 		release_sock(sk);
1593 		break;
1594 	}
1595 
1596 	case SIOCX25SENDCALLACCPT:  {
1597 		rc = -EINVAL;
1598 		lock_sock(sk);
1599 		if (sk->sk_state != TCP_ESTABLISHED)
1600 			goto out_sendcallaccpt_release;
1601 		/* must call accptapprv above */
1602 		if (test_bit(X25_ACCPT_APPRV_FLAG, &x25->flags))
1603 			goto out_sendcallaccpt_release;
1604 		x25_write_internal(sk, X25_CALL_ACCEPTED);
1605 		x25->state = X25_STATE_3;
1606 		rc = 0;
1607 out_sendcallaccpt_release:
1608 		release_sock(sk);
1609 		break;
1610 	}
1611 
1612 	default:
1613 		rc = -ENOIOCTLCMD;
1614 		break;
1615 	}
1616 
1617 	return rc;
1618 }
1619 
1620 static const struct net_proto_family x25_family_ops = {
1621 	.family =	AF_X25,
1622 	.create =	x25_create,
1623 	.owner	=	THIS_MODULE,
1624 };
1625 
1626 #ifdef CONFIG_COMPAT
1627 static int compat_x25_subscr_ioctl(unsigned int cmd,
1628 		struct compat_x25_subscrip_struct __user *x25_subscr32)
1629 {
1630 	struct compat_x25_subscrip_struct x25_subscr;
1631 	struct x25_neigh *nb;
1632 	struct net_device *dev;
1633 	int rc = -EINVAL;
1634 
1635 	rc = -EFAULT;
1636 	if (copy_from_user(&x25_subscr, x25_subscr32, sizeof(*x25_subscr32)))
1637 		goto out;
1638 
1639 	rc = -EINVAL;
1640 	dev = x25_dev_get(x25_subscr.device);
1641 	if (dev == NULL)
1642 		goto out;
1643 
1644 	nb = x25_get_neigh(dev);
1645 	if (nb == NULL)
1646 		goto out_dev_put;
1647 
1648 	dev_put(dev);
1649 
1650 	if (cmd == SIOCX25GSUBSCRIP) {
1651 		read_lock_bh(&x25_neigh_list_lock);
1652 		x25_subscr.extended = nb->extended;
1653 		x25_subscr.global_facil_mask = nb->global_facil_mask;
1654 		read_unlock_bh(&x25_neigh_list_lock);
1655 		rc = copy_to_user(x25_subscr32, &x25_subscr,
1656 				sizeof(*x25_subscr32)) ? -EFAULT : 0;
1657 	} else {
1658 		rc = -EINVAL;
1659 		if (x25_subscr.extended == 0 || x25_subscr.extended == 1) {
1660 			rc = 0;
1661 			write_lock_bh(&x25_neigh_list_lock);
1662 			nb->extended = x25_subscr.extended;
1663 			nb->global_facil_mask = x25_subscr.global_facil_mask;
1664 			write_unlock_bh(&x25_neigh_list_lock);
1665 		}
1666 	}
1667 	x25_neigh_put(nb);
1668 out:
1669 	return rc;
1670 out_dev_put:
1671 	dev_put(dev);
1672 	goto out;
1673 }
1674 
1675 static int compat_x25_ioctl(struct socket *sock, unsigned int cmd,
1676 				unsigned long arg)
1677 {
1678 	void __user *argp = compat_ptr(arg);
1679 	int rc = -ENOIOCTLCMD;
1680 
1681 	switch(cmd) {
1682 	case TIOCOUTQ:
1683 	case TIOCINQ:
1684 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1685 		break;
1686 	case SIOCGIFADDR:
1687 	case SIOCSIFADDR:
1688 	case SIOCGIFDSTADDR:
1689 	case SIOCSIFDSTADDR:
1690 	case SIOCGIFBRDADDR:
1691 	case SIOCSIFBRDADDR:
1692 	case SIOCGIFNETMASK:
1693 	case SIOCSIFNETMASK:
1694 	case SIOCGIFMETRIC:
1695 	case SIOCSIFMETRIC:
1696 		rc = -EINVAL;
1697 		break;
1698 	case SIOCADDRT:
1699 	case SIOCDELRT:
1700 		rc = -EPERM;
1701 		if (!capable(CAP_NET_ADMIN))
1702 			break;
1703 		rc = x25_route_ioctl(cmd, argp);
1704 		break;
1705 	case SIOCX25GSUBSCRIP:
1706 		rc = compat_x25_subscr_ioctl(cmd, argp);
1707 		break;
1708 	case SIOCX25SSUBSCRIP:
1709 		rc = -EPERM;
1710 		if (!capable(CAP_NET_ADMIN))
1711 			break;
1712 		rc = compat_x25_subscr_ioctl(cmd, argp);
1713 		break;
1714 	case SIOCX25GFACILITIES:
1715 	case SIOCX25SFACILITIES:
1716 	case SIOCX25GDTEFACILITIES:
1717 	case SIOCX25SDTEFACILITIES:
1718 	case SIOCX25GCALLUSERDATA:
1719 	case SIOCX25SCALLUSERDATA:
1720 	case SIOCX25GCAUSEDIAG:
1721 	case SIOCX25SCAUSEDIAG:
1722 	case SIOCX25SCUDMATCHLEN:
1723 	case SIOCX25CALLACCPTAPPRV:
1724 	case SIOCX25SENDCALLACCPT:
1725 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1726 		break;
1727 	default:
1728 		rc = -ENOIOCTLCMD;
1729 		break;
1730 	}
1731 	return rc;
1732 }
1733 #endif
1734 
1735 static const struct proto_ops x25_proto_ops = {
1736 	.family =	AF_X25,
1737 	.owner =	THIS_MODULE,
1738 	.release =	x25_release,
1739 	.bind =		x25_bind,
1740 	.connect =	x25_connect,
1741 	.socketpair =	sock_no_socketpair,
1742 	.accept =	x25_accept,
1743 	.getname =	x25_getname,
1744 	.poll =		datagram_poll,
1745 	.ioctl =	x25_ioctl,
1746 #ifdef CONFIG_COMPAT
1747 	.compat_ioctl = compat_x25_ioctl,
1748 #endif
1749 	.gettstamp =	sock_gettstamp,
1750 	.listen =	x25_listen,
1751 	.shutdown =	sock_no_shutdown,
1752 	.setsockopt =	x25_setsockopt,
1753 	.getsockopt =	x25_getsockopt,
1754 	.sendmsg =	x25_sendmsg,
1755 	.recvmsg =	x25_recvmsg,
1756 	.mmap =		sock_no_mmap,
1757 	.sendpage =	sock_no_sendpage,
1758 };
1759 
1760 static struct packet_type x25_packet_type __read_mostly = {
1761 	.type =	cpu_to_be16(ETH_P_X25),
1762 	.func =	x25_lapb_receive_frame,
1763 };
1764 
1765 static struct notifier_block x25_dev_notifier = {
1766 	.notifier_call = x25_device_event,
1767 };
1768 
1769 void x25_kill_by_neigh(struct x25_neigh *nb)
1770 {
1771 	struct sock *s;
1772 
1773 	write_lock_bh(&x25_list_lock);
1774 
1775 	sk_for_each(s, &x25_list)
1776 		if (x25_sk(s)->neighbour == nb)
1777 			x25_disconnect(s, ENETUNREACH, 0, 0);
1778 
1779 	write_unlock_bh(&x25_list_lock);
1780 
1781 	/* Remove any related forwards */
1782 	x25_clear_forward_by_dev(nb->dev);
1783 }
1784 
1785 static int __init x25_init(void)
1786 {
1787 	int rc;
1788 
1789 	rc = proto_register(&x25_proto, 0);
1790 	if (rc)
1791 		goto out;
1792 
1793 	rc = sock_register(&x25_family_ops);
1794 	if (rc)
1795 		goto out_proto;
1796 
1797 	dev_add_pack(&x25_packet_type);
1798 
1799 	rc = register_netdevice_notifier(&x25_dev_notifier);
1800 	if (rc)
1801 		goto out_sock;
1802 
1803 	rc = x25_register_sysctl();
1804 	if (rc)
1805 		goto out_dev;
1806 
1807 	rc = x25_proc_init();
1808 	if (rc)
1809 		goto out_sysctl;
1810 
1811 	pr_info("Linux Version 0.2\n");
1812 
1813 out:
1814 	return rc;
1815 out_sysctl:
1816 	x25_unregister_sysctl();
1817 out_dev:
1818 	unregister_netdevice_notifier(&x25_dev_notifier);
1819 out_sock:
1820 	dev_remove_pack(&x25_packet_type);
1821 	sock_unregister(AF_X25);
1822 out_proto:
1823 	proto_unregister(&x25_proto);
1824 	goto out;
1825 }
1826 module_init(x25_init);
1827 
1828 static void __exit x25_exit(void)
1829 {
1830 	x25_proc_exit();
1831 	x25_link_free();
1832 	x25_route_free();
1833 
1834 	x25_unregister_sysctl();
1835 
1836 	unregister_netdevice_notifier(&x25_dev_notifier);
1837 
1838 	dev_remove_pack(&x25_packet_type);
1839 
1840 	sock_unregister(AF_X25);
1841 	proto_unregister(&x25_proto);
1842 }
1843 module_exit(x25_exit);
1844 
1845 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
1846 MODULE_DESCRIPTION("The X.25 Packet Layer network layer protocol");
1847 MODULE_LICENSE("GPL");
1848 MODULE_ALIAS_NETPROTO(PF_X25);
1849