xref: /openbmc/linux/net/x25/af_x25.c (revision 28dce2c4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	X.25 Packet Layer release 002
4  *
5  *	This is ALPHA test software. This code may break your machine,
6  *	randomly fail to work with new releases, misbehave and/or generally
7  *	screw up. It might even work.
8  *
9  *	This code REQUIRES 2.1.15 or higher
10  *
11  *	History
12  *	X.25 001	Jonathan Naylor	Started coding.
13  *	X.25 002	Jonathan Naylor	Centralised disconnect handling.
14  *					New timer architecture.
15  *	2000-03-11	Henner Eisen	MSG_EOR handling more POSIX compliant.
16  *	2000-03-22	Daniela Squassoni Allowed disabling/enabling of
17  *					  facilities negotiation and increased
18  *					  the throughput upper limit.
19  *	2000-08-27	Arnaldo C. Melo s/suser/capable/ + micro cleanups
20  *	2000-09-04	Henner Eisen	Set sock->state in x25_accept().
21  *					Fixed x25_output() related skb leakage.
22  *	2000-10-02	Henner Eisen	Made x25_kick() single threaded per socket.
23  *	2000-10-27	Henner Eisen    MSG_DONTWAIT for fragment allocation.
24  *	2000-11-14	Henner Eisen    Closing datalink from NETDEV_GOING_DOWN
25  *	2002-10-06	Arnaldo C. Melo Get rid of cli/sti, move proc stuff to
26  *					x25_proc.c, using seq_file
27  *	2005-04-02	Shaun Pereira	Selective sub address matching
28  *					with call user data
29  *	2005-04-15	Shaun Pereira	Fast select with no restriction on
30  *					response
31  */
32 
33 #define pr_fmt(fmt) "X25: " fmt
34 
35 #include <linux/module.h>
36 #include <linux/capability.h>
37 #include <linux/errno.h>
38 #include <linux/kernel.h>
39 #include <linux/sched/signal.h>
40 #include <linux/timer.h>
41 #include <linux/string.h>
42 #include <linux/net.h>
43 #include <linux/netdevice.h>
44 #include <linux/if_arp.h>
45 #include <linux/skbuff.h>
46 #include <linux/slab.h>
47 #include <net/sock.h>
48 #include <net/tcp_states.h>
49 #include <linux/uaccess.h>
50 #include <linux/fcntl.h>
51 #include <linux/termios.h>	/* For TIOCINQ/OUTQ */
52 #include <linux/notifier.h>
53 #include <linux/init.h>
54 #include <linux/compat.h>
55 #include <linux/ctype.h>
56 
57 #include <net/x25.h>
58 #include <net/compat.h>
59 
60 int sysctl_x25_restart_request_timeout = X25_DEFAULT_T20;
61 int sysctl_x25_call_request_timeout    = X25_DEFAULT_T21;
62 int sysctl_x25_reset_request_timeout   = X25_DEFAULT_T22;
63 int sysctl_x25_clear_request_timeout   = X25_DEFAULT_T23;
64 int sysctl_x25_ack_holdback_timeout    = X25_DEFAULT_T2;
65 int sysctl_x25_forward                 = 0;
66 
67 HLIST_HEAD(x25_list);
68 DEFINE_RWLOCK(x25_list_lock);
69 
70 static const struct proto_ops x25_proto_ops;
71 
72 static const struct x25_address null_x25_address = {"               "};
73 
74 #ifdef CONFIG_COMPAT
75 struct compat_x25_subscrip_struct {
76 	char device[200-sizeof(compat_ulong_t)];
77 	compat_ulong_t global_facil_mask;
78 	compat_uint_t extended;
79 };
80 #endif
81 
82 
83 int x25_parse_address_block(struct sk_buff *skb,
84 		struct x25_address *called_addr,
85 		struct x25_address *calling_addr)
86 {
87 	unsigned char len;
88 	int needed;
89 	int rc;
90 
91 	if (!pskb_may_pull(skb, 1)) {
92 		/* packet has no address block */
93 		rc = 0;
94 		goto empty;
95 	}
96 
97 	len = *skb->data;
98 	needed = 1 + ((len >> 4) + (len & 0x0f) + 1) / 2;
99 
100 	if (!pskb_may_pull(skb, needed)) {
101 		/* packet is too short to hold the addresses it claims
102 		   to hold */
103 		rc = -1;
104 		goto empty;
105 	}
106 
107 	return x25_addr_ntoa(skb->data, called_addr, calling_addr);
108 
109 empty:
110 	*called_addr->x25_addr = 0;
111 	*calling_addr->x25_addr = 0;
112 
113 	return rc;
114 }
115 
116 
117 int x25_addr_ntoa(unsigned char *p, struct x25_address *called_addr,
118 		  struct x25_address *calling_addr)
119 {
120 	unsigned int called_len, calling_len;
121 	char *called, *calling;
122 	unsigned int i;
123 
124 	called_len  = (*p >> 0) & 0x0F;
125 	calling_len = (*p >> 4) & 0x0F;
126 
127 	called  = called_addr->x25_addr;
128 	calling = calling_addr->x25_addr;
129 	p++;
130 
131 	for (i = 0; i < (called_len + calling_len); i++) {
132 		if (i < called_len) {
133 			if (i % 2 != 0) {
134 				*called++ = ((*p >> 0) & 0x0F) + '0';
135 				p++;
136 			} else {
137 				*called++ = ((*p >> 4) & 0x0F) + '0';
138 			}
139 		} else {
140 			if (i % 2 != 0) {
141 				*calling++ = ((*p >> 0) & 0x0F) + '0';
142 				p++;
143 			} else {
144 				*calling++ = ((*p >> 4) & 0x0F) + '0';
145 			}
146 		}
147 	}
148 
149 	*called = *calling = '\0';
150 
151 	return 1 + (called_len + calling_len + 1) / 2;
152 }
153 
154 int x25_addr_aton(unsigned char *p, struct x25_address *called_addr,
155 		  struct x25_address *calling_addr)
156 {
157 	unsigned int called_len, calling_len;
158 	char *called, *calling;
159 	int i;
160 
161 	called  = called_addr->x25_addr;
162 	calling = calling_addr->x25_addr;
163 
164 	called_len  = strlen(called);
165 	calling_len = strlen(calling);
166 
167 	*p++ = (calling_len << 4) | (called_len << 0);
168 
169 	for (i = 0; i < (called_len + calling_len); i++) {
170 		if (i < called_len) {
171 			if (i % 2 != 0) {
172 				*p |= (*called++ - '0') << 0;
173 				p++;
174 			} else {
175 				*p = 0x00;
176 				*p |= (*called++ - '0') << 4;
177 			}
178 		} else {
179 			if (i % 2 != 0) {
180 				*p |= (*calling++ - '0') << 0;
181 				p++;
182 			} else {
183 				*p = 0x00;
184 				*p |= (*calling++ - '0') << 4;
185 			}
186 		}
187 	}
188 
189 	return 1 + (called_len + calling_len + 1) / 2;
190 }
191 
192 /*
193  *	Socket removal during an interrupt is now safe.
194  */
195 static void x25_remove_socket(struct sock *sk)
196 {
197 	write_lock_bh(&x25_list_lock);
198 	sk_del_node_init(sk);
199 	write_unlock_bh(&x25_list_lock);
200 }
201 
202 /*
203  *	Handle device status changes.
204  */
205 static int x25_device_event(struct notifier_block *this, unsigned long event,
206 			    void *ptr)
207 {
208 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
209 	struct x25_neigh *nb;
210 
211 	if (!net_eq(dev_net(dev), &init_net))
212 		return NOTIFY_DONE;
213 
214 	if (dev->type == ARPHRD_X25) {
215 		switch (event) {
216 		case NETDEV_REGISTER:
217 		case NETDEV_POST_TYPE_CHANGE:
218 			x25_link_device_up(dev);
219 			break;
220 		case NETDEV_DOWN:
221 			nb = x25_get_neigh(dev);
222 			if (nb) {
223 				x25_link_terminated(nb);
224 				x25_neigh_put(nb);
225 			}
226 			x25_route_device_down(dev);
227 			break;
228 		case NETDEV_PRE_TYPE_CHANGE:
229 		case NETDEV_UNREGISTER:
230 			x25_link_device_down(dev);
231 			break;
232 		case NETDEV_CHANGE:
233 			if (!netif_carrier_ok(dev)) {
234 				nb = x25_get_neigh(dev);
235 				if (nb) {
236 					x25_link_terminated(nb);
237 					x25_neigh_put(nb);
238 				}
239 			}
240 			break;
241 		}
242 	}
243 
244 	return NOTIFY_DONE;
245 }
246 
247 /*
248  *	Add a socket to the bound sockets list.
249  */
250 static void x25_insert_socket(struct sock *sk)
251 {
252 	write_lock_bh(&x25_list_lock);
253 	sk_add_node(sk, &x25_list);
254 	write_unlock_bh(&x25_list_lock);
255 }
256 
257 /*
258  *	Find a socket that wants to accept the Call Request we just
259  *	received. Check the full list for an address/cud match.
260  *	If no cuds match return the next_best thing, an address match.
261  *	Note: if a listening socket has cud set it must only get calls
262  *	with matching cud.
263  */
264 static struct sock *x25_find_listener(struct x25_address *addr,
265 					struct sk_buff *skb)
266 {
267 	struct sock *s;
268 	struct sock *next_best;
269 
270 	read_lock_bh(&x25_list_lock);
271 	next_best = NULL;
272 
273 	sk_for_each(s, &x25_list)
274 		if ((!strcmp(addr->x25_addr,
275 			x25_sk(s)->source_addr.x25_addr) ||
276 				!strcmp(x25_sk(s)->source_addr.x25_addr,
277 					null_x25_address.x25_addr)) &&
278 					s->sk_state == TCP_LISTEN) {
279 			/*
280 			 * Found a listening socket, now check the incoming
281 			 * call user data vs this sockets call user data
282 			 */
283 			if (x25_sk(s)->cudmatchlength > 0 &&
284 				skb->len >= x25_sk(s)->cudmatchlength) {
285 				if((memcmp(x25_sk(s)->calluserdata.cuddata,
286 					skb->data,
287 					x25_sk(s)->cudmatchlength)) == 0) {
288 					sock_hold(s);
289 					goto found;
290 				 }
291 			} else
292 				next_best = s;
293 		}
294 	if (next_best) {
295 		s = next_best;
296 		sock_hold(s);
297 		goto found;
298 	}
299 	s = NULL;
300 found:
301 	read_unlock_bh(&x25_list_lock);
302 	return s;
303 }
304 
305 /*
306  *	Find a connected X.25 socket given my LCI and neighbour.
307  */
308 static struct sock *__x25_find_socket(unsigned int lci, struct x25_neigh *nb)
309 {
310 	struct sock *s;
311 
312 	sk_for_each(s, &x25_list)
313 		if (x25_sk(s)->lci == lci && x25_sk(s)->neighbour == nb) {
314 			sock_hold(s);
315 			goto found;
316 		}
317 	s = NULL;
318 found:
319 	return s;
320 }
321 
322 struct sock *x25_find_socket(unsigned int lci, struct x25_neigh *nb)
323 {
324 	struct sock *s;
325 
326 	read_lock_bh(&x25_list_lock);
327 	s = __x25_find_socket(lci, nb);
328 	read_unlock_bh(&x25_list_lock);
329 	return s;
330 }
331 
332 /*
333  *	Find a unique LCI for a given device.
334  */
335 static unsigned int x25_new_lci(struct x25_neigh *nb)
336 {
337 	unsigned int lci = 1;
338 	struct sock *sk;
339 
340 	while ((sk = x25_find_socket(lci, nb)) != NULL) {
341 		sock_put(sk);
342 		if (++lci == 4096) {
343 			lci = 0;
344 			break;
345 		}
346 		cond_resched();
347 	}
348 
349 	return lci;
350 }
351 
352 /*
353  *	Deferred destroy.
354  */
355 static void __x25_destroy_socket(struct sock *);
356 
357 /*
358  *	handler for deferred kills.
359  */
360 static void x25_destroy_timer(struct timer_list *t)
361 {
362 	struct sock *sk = from_timer(sk, t, sk_timer);
363 
364 	x25_destroy_socket_from_timer(sk);
365 }
366 
367 /*
368  *	This is called from user mode and the timers. Thus it protects itself
369  *	against interrupt users but doesn't worry about being called during
370  *	work. Once it is removed from the queue no interrupt or bottom half
371  *	will touch it and we are (fairly 8-) ) safe.
372  *	Not static as it's used by the timer
373  */
374 static void __x25_destroy_socket(struct sock *sk)
375 {
376 	struct sk_buff *skb;
377 
378 	x25_stop_heartbeat(sk);
379 	x25_stop_timer(sk);
380 
381 	x25_remove_socket(sk);
382 	x25_clear_queues(sk);		/* Flush the queues */
383 
384 	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
385 		if (skb->sk != sk) {		/* A pending connection */
386 			/*
387 			 * Queue the unaccepted socket for death
388 			 */
389 			skb->sk->sk_state = TCP_LISTEN;
390 			sock_set_flag(skb->sk, SOCK_DEAD);
391 			x25_start_heartbeat(skb->sk);
392 			x25_sk(skb->sk)->state = X25_STATE_0;
393 		}
394 
395 		kfree_skb(skb);
396 	}
397 
398 	if (sk_has_allocations(sk)) {
399 		/* Defer: outstanding buffers */
400 		sk->sk_timer.expires  = jiffies + 10 * HZ;
401 		sk->sk_timer.function = x25_destroy_timer;
402 		add_timer(&sk->sk_timer);
403 	} else {
404 		/* drop last reference so sock_put will free */
405 		__sock_put(sk);
406 	}
407 }
408 
409 void x25_destroy_socket_from_timer(struct sock *sk)
410 {
411 	sock_hold(sk);
412 	bh_lock_sock(sk);
413 	__x25_destroy_socket(sk);
414 	bh_unlock_sock(sk);
415 	sock_put(sk);
416 }
417 
418 /*
419  *	Handling for system calls applied via the various interfaces to a
420  *	X.25 socket object.
421  */
422 
423 static int x25_setsockopt(struct socket *sock, int level, int optname,
424 			  sockptr_t optval, unsigned int optlen)
425 {
426 	int opt;
427 	struct sock *sk = sock->sk;
428 	int rc = -ENOPROTOOPT;
429 
430 	if (level != SOL_X25 || optname != X25_QBITINCL)
431 		goto out;
432 
433 	rc = -EINVAL;
434 	if (optlen < sizeof(int))
435 		goto out;
436 
437 	rc = -EFAULT;
438 	if (copy_from_sockptr(&opt, optval, sizeof(int)))
439 		goto out;
440 
441 	if (opt)
442 		set_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
443 	else
444 		clear_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
445 	rc = 0;
446 out:
447 	return rc;
448 }
449 
450 static int x25_getsockopt(struct socket *sock, int level, int optname,
451 			  char __user *optval, int __user *optlen)
452 {
453 	struct sock *sk = sock->sk;
454 	int val, len, rc = -ENOPROTOOPT;
455 
456 	if (level != SOL_X25 || optname != X25_QBITINCL)
457 		goto out;
458 
459 	rc = -EFAULT;
460 	if (get_user(len, optlen))
461 		goto out;
462 
463 	len = min_t(unsigned int, len, sizeof(int));
464 
465 	rc = -EINVAL;
466 	if (len < 0)
467 		goto out;
468 
469 	rc = -EFAULT;
470 	if (put_user(len, optlen))
471 		goto out;
472 
473 	val = test_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
474 	rc = copy_to_user(optval, &val, len) ? -EFAULT : 0;
475 out:
476 	return rc;
477 }
478 
479 static int x25_listen(struct socket *sock, int backlog)
480 {
481 	struct sock *sk = sock->sk;
482 	int rc = -EOPNOTSUPP;
483 
484 	lock_sock(sk);
485 	if (sk->sk_state != TCP_LISTEN) {
486 		memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN);
487 		sk->sk_max_ack_backlog = backlog;
488 		sk->sk_state           = TCP_LISTEN;
489 		rc = 0;
490 	}
491 	release_sock(sk);
492 
493 	return rc;
494 }
495 
496 static struct proto x25_proto = {
497 	.name	  = "X25",
498 	.owner	  = THIS_MODULE,
499 	.obj_size = sizeof(struct x25_sock),
500 };
501 
502 static struct sock *x25_alloc_socket(struct net *net, int kern)
503 {
504 	struct x25_sock *x25;
505 	struct sock *sk = sk_alloc(net, AF_X25, GFP_ATOMIC, &x25_proto, kern);
506 
507 	if (!sk)
508 		goto out;
509 
510 	sock_init_data(NULL, sk);
511 
512 	x25 = x25_sk(sk);
513 	skb_queue_head_init(&x25->ack_queue);
514 	skb_queue_head_init(&x25->fragment_queue);
515 	skb_queue_head_init(&x25->interrupt_in_queue);
516 	skb_queue_head_init(&x25->interrupt_out_queue);
517 out:
518 	return sk;
519 }
520 
521 static int x25_create(struct net *net, struct socket *sock, int protocol,
522 		      int kern)
523 {
524 	struct sock *sk;
525 	struct x25_sock *x25;
526 	int rc = -EAFNOSUPPORT;
527 
528 	if (!net_eq(net, &init_net))
529 		goto out;
530 
531 	rc = -ESOCKTNOSUPPORT;
532 	if (sock->type != SOCK_SEQPACKET)
533 		goto out;
534 
535 	rc = -EINVAL;
536 	if (protocol)
537 		goto out;
538 
539 	rc = -ENOBUFS;
540 	if ((sk = x25_alloc_socket(net, kern)) == NULL)
541 		goto out;
542 
543 	x25 = x25_sk(sk);
544 
545 	sock_init_data(sock, sk);
546 
547 	x25_init_timers(sk);
548 
549 	sock->ops    = &x25_proto_ops;
550 	sk->sk_protocol = protocol;
551 	sk->sk_backlog_rcv = x25_backlog_rcv;
552 
553 	x25->t21   = sysctl_x25_call_request_timeout;
554 	x25->t22   = sysctl_x25_reset_request_timeout;
555 	x25->t23   = sysctl_x25_clear_request_timeout;
556 	x25->t2    = sysctl_x25_ack_holdback_timeout;
557 	x25->state = X25_STATE_0;
558 	x25->cudmatchlength = 0;
559 	set_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);	/* normally no cud  */
560 							/* on call accept   */
561 
562 	x25->facilities.winsize_in  = X25_DEFAULT_WINDOW_SIZE;
563 	x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
564 	x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
565 	x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
566 	x25->facilities.throughput  = 0;	/* by default don't negotiate
567 						   throughput */
568 	x25->facilities.reverse     = X25_DEFAULT_REVERSE;
569 	x25->dte_facilities.calling_len = 0;
570 	x25->dte_facilities.called_len = 0;
571 	memset(x25->dte_facilities.called_ae, '\0',
572 			sizeof(x25->dte_facilities.called_ae));
573 	memset(x25->dte_facilities.calling_ae, '\0',
574 			sizeof(x25->dte_facilities.calling_ae));
575 
576 	rc = 0;
577 out:
578 	return rc;
579 }
580 
581 static struct sock *x25_make_new(struct sock *osk)
582 {
583 	struct sock *sk = NULL;
584 	struct x25_sock *x25, *ox25;
585 
586 	if (osk->sk_type != SOCK_SEQPACKET)
587 		goto out;
588 
589 	if ((sk = x25_alloc_socket(sock_net(osk), 0)) == NULL)
590 		goto out;
591 
592 	x25 = x25_sk(sk);
593 
594 	sk->sk_type        = osk->sk_type;
595 	sk->sk_priority    = osk->sk_priority;
596 	sk->sk_protocol    = osk->sk_protocol;
597 	sk->sk_rcvbuf      = osk->sk_rcvbuf;
598 	sk->sk_sndbuf      = osk->sk_sndbuf;
599 	sk->sk_state       = TCP_ESTABLISHED;
600 	sk->sk_backlog_rcv = osk->sk_backlog_rcv;
601 	sock_copy_flags(sk, osk);
602 
603 	ox25 = x25_sk(osk);
604 	x25->t21        = ox25->t21;
605 	x25->t22        = ox25->t22;
606 	x25->t23        = ox25->t23;
607 	x25->t2         = ox25->t2;
608 	x25->flags	= ox25->flags;
609 	x25->facilities = ox25->facilities;
610 	x25->dte_facilities = ox25->dte_facilities;
611 	x25->cudmatchlength = ox25->cudmatchlength;
612 
613 	clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
614 	x25_init_timers(sk);
615 out:
616 	return sk;
617 }
618 
619 static int x25_release(struct socket *sock)
620 {
621 	struct sock *sk = sock->sk;
622 	struct x25_sock *x25;
623 
624 	if (!sk)
625 		return 0;
626 
627 	x25 = x25_sk(sk);
628 
629 	sock_hold(sk);
630 	lock_sock(sk);
631 	switch (x25->state) {
632 
633 		case X25_STATE_0:
634 		case X25_STATE_2:
635 			x25_disconnect(sk, 0, 0, 0);
636 			__x25_destroy_socket(sk);
637 			goto out;
638 
639 		case X25_STATE_1:
640 		case X25_STATE_3:
641 		case X25_STATE_4:
642 			x25_clear_queues(sk);
643 			x25_write_internal(sk, X25_CLEAR_REQUEST);
644 			x25_start_t23timer(sk);
645 			x25->state = X25_STATE_2;
646 			sk->sk_state	= TCP_CLOSE;
647 			sk->sk_shutdown	|= SEND_SHUTDOWN;
648 			sk->sk_state_change(sk);
649 			sock_set_flag(sk, SOCK_DEAD);
650 			sock_set_flag(sk, SOCK_DESTROY);
651 			break;
652 
653 		case X25_STATE_5:
654 			x25_write_internal(sk, X25_CLEAR_REQUEST);
655 			x25_disconnect(sk, 0, 0, 0);
656 			__x25_destroy_socket(sk);
657 			goto out;
658 	}
659 
660 	sock_orphan(sk);
661 out:
662 	release_sock(sk);
663 	sock_put(sk);
664 	return 0;
665 }
666 
667 static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
668 {
669 	struct sock *sk = sock->sk;
670 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
671 	int len, i, rc = 0;
672 
673 	if (addr_len != sizeof(struct sockaddr_x25) ||
674 	    addr->sx25_family != AF_X25 ||
675 	    strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) {
676 		rc = -EINVAL;
677 		goto out;
678 	}
679 
680 	/* check for the null_x25_address */
681 	if (strcmp(addr->sx25_addr.x25_addr, null_x25_address.x25_addr)) {
682 
683 		len = strlen(addr->sx25_addr.x25_addr);
684 		for (i = 0; i < len; i++) {
685 			if (!isdigit(addr->sx25_addr.x25_addr[i])) {
686 				rc = -EINVAL;
687 				goto out;
688 			}
689 		}
690 	}
691 
692 	lock_sock(sk);
693 	if (sock_flag(sk, SOCK_ZAPPED)) {
694 		x25_sk(sk)->source_addr = addr->sx25_addr;
695 		x25_insert_socket(sk);
696 		sock_reset_flag(sk, SOCK_ZAPPED);
697 	} else {
698 		rc = -EINVAL;
699 	}
700 	release_sock(sk);
701 	SOCK_DEBUG(sk, "x25_bind: socket is bound\n");
702 out:
703 	return rc;
704 }
705 
706 static int x25_wait_for_connection_establishment(struct sock *sk)
707 {
708 	DECLARE_WAITQUEUE(wait, current);
709 	int rc;
710 
711 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
712 	for (;;) {
713 		__set_current_state(TASK_INTERRUPTIBLE);
714 		rc = -ERESTARTSYS;
715 		if (signal_pending(current))
716 			break;
717 		rc = sock_error(sk);
718 		if (rc) {
719 			sk->sk_socket->state = SS_UNCONNECTED;
720 			break;
721 		}
722 		rc = 0;
723 		if (sk->sk_state != TCP_ESTABLISHED) {
724 			release_sock(sk);
725 			schedule();
726 			lock_sock(sk);
727 		} else
728 			break;
729 	}
730 	__set_current_state(TASK_RUNNING);
731 	remove_wait_queue(sk_sleep(sk), &wait);
732 	return rc;
733 }
734 
735 static int x25_connect(struct socket *sock, struct sockaddr *uaddr,
736 		       int addr_len, int flags)
737 {
738 	struct sock *sk = sock->sk;
739 	struct x25_sock *x25 = x25_sk(sk);
740 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
741 	struct x25_route *rt;
742 	int rc = 0;
743 
744 	lock_sock(sk);
745 	if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
746 		sock->state = SS_CONNECTED;
747 		goto out; /* Connect completed during a ERESTARTSYS event */
748 	}
749 
750 	rc = -ECONNREFUSED;
751 	if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
752 		sock->state = SS_UNCONNECTED;
753 		goto out;
754 	}
755 
756 	rc = -EISCONN;	/* No reconnect on a seqpacket socket */
757 	if (sk->sk_state == TCP_ESTABLISHED)
758 		goto out;
759 
760 	rc = -EALREADY;	/* Do nothing if call is already in progress */
761 	if (sk->sk_state == TCP_SYN_SENT)
762 		goto out;
763 
764 	sk->sk_state   = TCP_CLOSE;
765 	sock->state = SS_UNCONNECTED;
766 
767 	rc = -EINVAL;
768 	if (addr_len != sizeof(struct sockaddr_x25) ||
769 	    addr->sx25_family != AF_X25 ||
770 	    strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN)
771 		goto out;
772 
773 	rc = -ENETUNREACH;
774 	rt = x25_get_route(&addr->sx25_addr);
775 	if (!rt)
776 		goto out;
777 
778 	x25->neighbour = x25_get_neigh(rt->dev);
779 	if (!x25->neighbour)
780 		goto out_put_route;
781 
782 	x25_limit_facilities(&x25->facilities, x25->neighbour);
783 
784 	x25->lci = x25_new_lci(x25->neighbour);
785 	if (!x25->lci)
786 		goto out_put_neigh;
787 
788 	rc = -EINVAL;
789 	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
790 		goto out_put_neigh;
791 
792 	if (!strcmp(x25->source_addr.x25_addr, null_x25_address.x25_addr))
793 		memset(&x25->source_addr, '\0', X25_ADDR_LEN);
794 
795 	x25->dest_addr = addr->sx25_addr;
796 
797 	/* Move to connecting socket, start sending Connect Requests */
798 	sock->state   = SS_CONNECTING;
799 	sk->sk_state  = TCP_SYN_SENT;
800 
801 	x25->state = X25_STATE_1;
802 
803 	x25_write_internal(sk, X25_CALL_REQUEST);
804 
805 	x25_start_heartbeat(sk);
806 	x25_start_t21timer(sk);
807 
808 	/* Now the loop */
809 	rc = -EINPROGRESS;
810 	if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK))
811 		goto out;
812 
813 	rc = x25_wait_for_connection_establishment(sk);
814 	if (rc)
815 		goto out_put_neigh;
816 
817 	sock->state = SS_CONNECTED;
818 	rc = 0;
819 out_put_neigh:
820 	if (rc && x25->neighbour) {
821 		read_lock_bh(&x25_list_lock);
822 		x25_neigh_put(x25->neighbour);
823 		x25->neighbour = NULL;
824 		read_unlock_bh(&x25_list_lock);
825 		x25->state = X25_STATE_0;
826 	}
827 out_put_route:
828 	x25_route_put(rt);
829 out:
830 	release_sock(sk);
831 	return rc;
832 }
833 
834 static int x25_wait_for_data(struct sock *sk, long timeout)
835 {
836 	DECLARE_WAITQUEUE(wait, current);
837 	int rc = 0;
838 
839 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
840 	for (;;) {
841 		__set_current_state(TASK_INTERRUPTIBLE);
842 		if (sk->sk_shutdown & RCV_SHUTDOWN)
843 			break;
844 		rc = -ERESTARTSYS;
845 		if (signal_pending(current))
846 			break;
847 		rc = -EAGAIN;
848 		if (!timeout)
849 			break;
850 		rc = 0;
851 		if (skb_queue_empty(&sk->sk_receive_queue)) {
852 			release_sock(sk);
853 			timeout = schedule_timeout(timeout);
854 			lock_sock(sk);
855 		} else
856 			break;
857 	}
858 	__set_current_state(TASK_RUNNING);
859 	remove_wait_queue(sk_sleep(sk), &wait);
860 	return rc;
861 }
862 
863 static int x25_accept(struct socket *sock, struct socket *newsock, int flags,
864 		      bool kern)
865 {
866 	struct sock *sk = sock->sk;
867 	struct sock *newsk;
868 	struct sk_buff *skb;
869 	int rc = -EINVAL;
870 
871 	if (!sk)
872 		goto out;
873 
874 	rc = -EOPNOTSUPP;
875 	if (sk->sk_type != SOCK_SEQPACKET)
876 		goto out;
877 
878 	lock_sock(sk);
879 	rc = -EINVAL;
880 	if (sk->sk_state != TCP_LISTEN)
881 		goto out2;
882 
883 	rc = x25_wait_for_data(sk, sk->sk_rcvtimeo);
884 	if (rc)
885 		goto out2;
886 	skb = skb_dequeue(&sk->sk_receive_queue);
887 	rc = -EINVAL;
888 	if (!skb->sk)
889 		goto out2;
890 	newsk		 = skb->sk;
891 	sock_graft(newsk, newsock);
892 
893 	/* Now attach up the new socket */
894 	skb->sk = NULL;
895 	kfree_skb(skb);
896 	sk_acceptq_removed(sk);
897 	newsock->state = SS_CONNECTED;
898 	rc = 0;
899 out2:
900 	release_sock(sk);
901 out:
902 	return rc;
903 }
904 
905 static int x25_getname(struct socket *sock, struct sockaddr *uaddr,
906 		       int peer)
907 {
908 	struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)uaddr;
909 	struct sock *sk = sock->sk;
910 	struct x25_sock *x25 = x25_sk(sk);
911 	int rc = 0;
912 
913 	if (peer) {
914 		if (sk->sk_state != TCP_ESTABLISHED) {
915 			rc = -ENOTCONN;
916 			goto out;
917 		}
918 		sx25->sx25_addr = x25->dest_addr;
919 	} else
920 		sx25->sx25_addr = x25->source_addr;
921 
922 	sx25->sx25_family = AF_X25;
923 	rc = sizeof(*sx25);
924 
925 out:
926 	return rc;
927 }
928 
929 int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
930 			unsigned int lci)
931 {
932 	struct sock *sk;
933 	struct sock *make;
934 	struct x25_sock *makex25;
935 	struct x25_address source_addr, dest_addr;
936 	struct x25_facilities facilities;
937 	struct x25_dte_facilities dte_facilities;
938 	int len, addr_len, rc;
939 
940 	/*
941 	 *	Remove the LCI and frame type.
942 	 */
943 	skb_pull(skb, X25_STD_MIN_LEN);
944 
945 	/*
946 	 *	Extract the X.25 addresses and convert them to ASCII strings,
947 	 *	and remove them.
948 	 *
949 	 *	Address block is mandatory in call request packets
950 	 */
951 	addr_len = x25_parse_address_block(skb, &source_addr, &dest_addr);
952 	if (addr_len <= 0)
953 		goto out_clear_request;
954 	skb_pull(skb, addr_len);
955 
956 	/*
957 	 *	Get the length of the facilities, skip past them for the moment
958 	 *	get the call user data because this is needed to determine
959 	 *	the correct listener
960 	 *
961 	 *	Facilities length is mandatory in call request packets
962 	 */
963 	if (!pskb_may_pull(skb, 1))
964 		goto out_clear_request;
965 	len = skb->data[0] + 1;
966 	if (!pskb_may_pull(skb, len))
967 		goto out_clear_request;
968 	skb_pull(skb,len);
969 
970 	/*
971 	 *	Ensure that the amount of call user data is valid.
972 	 */
973 	if (skb->len > X25_MAX_CUD_LEN)
974 		goto out_clear_request;
975 
976 	/*
977 	 *	Get all the call user data so it can be used in
978 	 *	x25_find_listener and skb_copy_from_linear_data up ahead.
979 	 */
980 	if (!pskb_may_pull(skb, skb->len))
981 		goto out_clear_request;
982 
983 	/*
984 	 *	Find a listener for the particular address/cud pair.
985 	 */
986 	sk = x25_find_listener(&source_addr,skb);
987 	skb_push(skb,len);
988 
989 	if (sk != NULL && sk_acceptq_is_full(sk)) {
990 		goto out_sock_put;
991 	}
992 
993 	/*
994 	 *	We dont have any listeners for this incoming call.
995 	 *	Try forwarding it.
996 	 */
997 	if (sk == NULL) {
998 		skb_push(skb, addr_len + X25_STD_MIN_LEN);
999 		if (sysctl_x25_forward &&
1000 				x25_forward_call(&dest_addr, nb, skb, lci) > 0)
1001 		{
1002 			/* Call was forwarded, dont process it any more */
1003 			kfree_skb(skb);
1004 			rc = 1;
1005 			goto out;
1006 		} else {
1007 			/* No listeners, can't forward, clear the call */
1008 			goto out_clear_request;
1009 		}
1010 	}
1011 
1012 	/*
1013 	 *	Try to reach a compromise on the requested facilities.
1014 	 */
1015 	len = x25_negotiate_facilities(skb, sk, &facilities, &dte_facilities);
1016 	if (len == -1)
1017 		goto out_sock_put;
1018 
1019 	/*
1020 	 * current neighbour/link might impose additional limits
1021 	 * on certain facilities
1022 	 */
1023 
1024 	x25_limit_facilities(&facilities, nb);
1025 
1026 	/*
1027 	 *	Try to create a new socket.
1028 	 */
1029 	make = x25_make_new(sk);
1030 	if (!make)
1031 		goto out_sock_put;
1032 
1033 	/*
1034 	 *	Remove the facilities
1035 	 */
1036 	skb_pull(skb, len);
1037 
1038 	skb->sk     = make;
1039 	make->sk_state = TCP_ESTABLISHED;
1040 
1041 	makex25 = x25_sk(make);
1042 	makex25->lci           = lci;
1043 	makex25->dest_addr     = dest_addr;
1044 	makex25->source_addr   = source_addr;
1045 	x25_neigh_hold(nb);
1046 	makex25->neighbour     = nb;
1047 	makex25->facilities    = facilities;
1048 	makex25->dte_facilities= dte_facilities;
1049 	makex25->vc_facil_mask = x25_sk(sk)->vc_facil_mask;
1050 	/* ensure no reverse facil on accept */
1051 	makex25->vc_facil_mask &= ~X25_MASK_REVERSE;
1052 	/* ensure no calling address extension on accept */
1053 	makex25->vc_facil_mask &= ~X25_MASK_CALLING_AE;
1054 	makex25->cudmatchlength = x25_sk(sk)->cudmatchlength;
1055 
1056 	/* Normally all calls are accepted immediately */
1057 	if (test_bit(X25_ACCPT_APPRV_FLAG, &makex25->flags)) {
1058 		x25_write_internal(make, X25_CALL_ACCEPTED);
1059 		makex25->state = X25_STATE_3;
1060 	} else {
1061 		makex25->state = X25_STATE_5;
1062 	}
1063 
1064 	/*
1065 	 *	Incoming Call User Data.
1066 	 */
1067 	skb_copy_from_linear_data(skb, makex25->calluserdata.cuddata, skb->len);
1068 	makex25->calluserdata.cudlength = skb->len;
1069 
1070 	sk_acceptq_added(sk);
1071 
1072 	x25_insert_socket(make);
1073 
1074 	skb_queue_head(&sk->sk_receive_queue, skb);
1075 
1076 	x25_start_heartbeat(make);
1077 
1078 	if (!sock_flag(sk, SOCK_DEAD))
1079 		sk->sk_data_ready(sk);
1080 	rc = 1;
1081 	sock_put(sk);
1082 out:
1083 	return rc;
1084 out_sock_put:
1085 	sock_put(sk);
1086 out_clear_request:
1087 	rc = 0;
1088 	x25_transmit_clear_request(nb, lci, 0x01);
1089 	goto out;
1090 }
1091 
1092 static int x25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1093 {
1094 	struct sock *sk = sock->sk;
1095 	struct x25_sock *x25 = x25_sk(sk);
1096 	DECLARE_SOCKADDR(struct sockaddr_x25 *, usx25, msg->msg_name);
1097 	struct sockaddr_x25 sx25;
1098 	struct sk_buff *skb;
1099 	unsigned char *asmptr;
1100 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1101 	size_t size;
1102 	int qbit = 0, rc = -EINVAL;
1103 
1104 	lock_sock(sk);
1105 	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_OOB|MSG_EOR|MSG_CMSG_COMPAT))
1106 		goto out;
1107 
1108 	/* we currently don't support segmented records at the user interface */
1109 	if (!(msg->msg_flags & (MSG_EOR|MSG_OOB)))
1110 		goto out;
1111 
1112 	rc = -EADDRNOTAVAIL;
1113 	if (sock_flag(sk, SOCK_ZAPPED))
1114 		goto out;
1115 
1116 	rc = -EPIPE;
1117 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1118 		send_sig(SIGPIPE, current, 0);
1119 		goto out;
1120 	}
1121 
1122 	rc = -ENETUNREACH;
1123 	if (!x25->neighbour)
1124 		goto out;
1125 
1126 	if (usx25) {
1127 		rc = -EINVAL;
1128 		if (msg->msg_namelen < sizeof(sx25))
1129 			goto out;
1130 		memcpy(&sx25, usx25, sizeof(sx25));
1131 		rc = -EISCONN;
1132 		if (strcmp(x25->dest_addr.x25_addr, sx25.sx25_addr.x25_addr))
1133 			goto out;
1134 		rc = -EINVAL;
1135 		if (sx25.sx25_family != AF_X25)
1136 			goto out;
1137 	} else {
1138 		/*
1139 		 *	FIXME 1003.1g - if the socket is like this because
1140 		 *	it has become closed (not started closed) we ought
1141 		 *	to SIGPIPE, EPIPE;
1142 		 */
1143 		rc = -ENOTCONN;
1144 		if (sk->sk_state != TCP_ESTABLISHED)
1145 			goto out;
1146 
1147 		sx25.sx25_family = AF_X25;
1148 		sx25.sx25_addr   = x25->dest_addr;
1149 	}
1150 
1151 	/* Sanity check the packet size */
1152 	if (len > 65535) {
1153 		rc = -EMSGSIZE;
1154 		goto out;
1155 	}
1156 
1157 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: Addresses built.\n");
1158 
1159 	/* Build a packet */
1160 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: building packet.\n");
1161 
1162 	if ((msg->msg_flags & MSG_OOB) && len > 32)
1163 		len = 32;
1164 
1165 	size = len + X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
1166 
1167 	release_sock(sk);
1168 	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
1169 	lock_sock(sk);
1170 	if (!skb)
1171 		goto out;
1172 	X25_SKB_CB(skb)->flags = msg->msg_flags;
1173 
1174 	skb_reserve(skb, X25_MAX_L2_LEN + X25_EXT_MIN_LEN);
1175 
1176 	/*
1177 	 *	Put the data on the end
1178 	 */
1179 	SOCK_DEBUG(sk, "x25_sendmsg: Copying user data\n");
1180 
1181 	skb_reset_transport_header(skb);
1182 	skb_put(skb, len);
1183 
1184 	rc = memcpy_from_msg(skb_transport_header(skb), msg, len);
1185 	if (rc)
1186 		goto out_kfree_skb;
1187 
1188 	/*
1189 	 *	If the Q BIT Include socket option is in force, the first
1190 	 *	byte of the user data is the logical value of the Q Bit.
1191 	 */
1192 	if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1193 		if (!pskb_may_pull(skb, 1))
1194 			goto out_kfree_skb;
1195 
1196 		qbit = skb->data[0];
1197 		skb_pull(skb, 1);
1198 	}
1199 
1200 	/*
1201 	 *	Push down the X.25 header
1202 	 */
1203 	SOCK_DEBUG(sk, "x25_sendmsg: Building X.25 Header.\n");
1204 
1205 	if (msg->msg_flags & MSG_OOB) {
1206 		if (x25->neighbour->extended) {
1207 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1208 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1209 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1210 			*asmptr++ = X25_INTERRUPT;
1211 		} else {
1212 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1213 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1214 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1215 			*asmptr++ = X25_INTERRUPT;
1216 		}
1217 	} else {
1218 		if (x25->neighbour->extended) {
1219 			/* Build an Extended X.25 header */
1220 			asmptr    = skb_push(skb, X25_EXT_MIN_LEN);
1221 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1222 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1223 			*asmptr++ = X25_DATA;
1224 			*asmptr++ = X25_DATA;
1225 		} else {
1226 			/* Build an Standard X.25 header */
1227 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1228 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1229 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1230 			*asmptr++ = X25_DATA;
1231 		}
1232 
1233 		if (qbit)
1234 			skb->data[0] |= X25_Q_BIT;
1235 	}
1236 
1237 	SOCK_DEBUG(sk, "x25_sendmsg: Built header.\n");
1238 	SOCK_DEBUG(sk, "x25_sendmsg: Transmitting buffer\n");
1239 
1240 	rc = -ENOTCONN;
1241 	if (sk->sk_state != TCP_ESTABLISHED)
1242 		goto out_kfree_skb;
1243 
1244 	if (msg->msg_flags & MSG_OOB)
1245 		skb_queue_tail(&x25->interrupt_out_queue, skb);
1246 	else {
1247 		rc = x25_output(sk, skb);
1248 		len = rc;
1249 		if (rc < 0)
1250 			kfree_skb(skb);
1251 		else if (test_bit(X25_Q_BIT_FLAG, &x25->flags))
1252 			len++;
1253 	}
1254 
1255 	x25_kick(sk);
1256 	rc = len;
1257 out:
1258 	release_sock(sk);
1259 	return rc;
1260 out_kfree_skb:
1261 	kfree_skb(skb);
1262 	goto out;
1263 }
1264 
1265 
1266 static int x25_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1267 		       int flags)
1268 {
1269 	struct sock *sk = sock->sk;
1270 	struct x25_sock *x25 = x25_sk(sk);
1271 	DECLARE_SOCKADDR(struct sockaddr_x25 *, sx25, msg->msg_name);
1272 	size_t copied;
1273 	int qbit, header_len;
1274 	struct sk_buff *skb;
1275 	unsigned char *asmptr;
1276 	int rc = -ENOTCONN;
1277 
1278 	lock_sock(sk);
1279 
1280 	if (x25->neighbour == NULL)
1281 		goto out;
1282 
1283 	header_len = x25->neighbour->extended ?
1284 		X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
1285 
1286 	/*
1287 	 * This works for seqpacket too. The receiver has ordered the queue for
1288 	 * us! We do one quick check first though
1289 	 */
1290 	if (sk->sk_state != TCP_ESTABLISHED)
1291 		goto out;
1292 
1293 	if (flags & MSG_OOB) {
1294 		rc = -EINVAL;
1295 		if (sock_flag(sk, SOCK_URGINLINE) ||
1296 		    !skb_peek(&x25->interrupt_in_queue))
1297 			goto out;
1298 
1299 		skb = skb_dequeue(&x25->interrupt_in_queue);
1300 
1301 		if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
1302 			goto out_free_dgram;
1303 
1304 		skb_pull(skb, X25_STD_MIN_LEN);
1305 
1306 		/*
1307 		 *	No Q bit information on Interrupt data.
1308 		 */
1309 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1310 			asmptr  = skb_push(skb, 1);
1311 			*asmptr = 0x00;
1312 		}
1313 
1314 		msg->msg_flags |= MSG_OOB;
1315 	} else {
1316 		/* Now we can treat all alike */
1317 		release_sock(sk);
1318 		skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1319 					flags & MSG_DONTWAIT, &rc);
1320 		lock_sock(sk);
1321 		if (!skb)
1322 			goto out;
1323 
1324 		if (!pskb_may_pull(skb, header_len))
1325 			goto out_free_dgram;
1326 
1327 		qbit = (skb->data[0] & X25_Q_BIT) == X25_Q_BIT;
1328 
1329 		skb_pull(skb, header_len);
1330 
1331 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1332 			asmptr  = skb_push(skb, 1);
1333 			*asmptr = qbit;
1334 		}
1335 	}
1336 
1337 	skb_reset_transport_header(skb);
1338 	copied = skb->len;
1339 
1340 	if (copied > size) {
1341 		copied = size;
1342 		msg->msg_flags |= MSG_TRUNC;
1343 	}
1344 
1345 	/* Currently, each datagram always contains a complete record */
1346 	msg->msg_flags |= MSG_EOR;
1347 
1348 	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
1349 	if (rc)
1350 		goto out_free_dgram;
1351 
1352 	if (sx25) {
1353 		sx25->sx25_family = AF_X25;
1354 		sx25->sx25_addr   = x25->dest_addr;
1355 		msg->msg_namelen = sizeof(*sx25);
1356 	}
1357 
1358 	x25_check_rbuf(sk);
1359 	rc = copied;
1360 out_free_dgram:
1361 	skb_free_datagram(sk, skb);
1362 out:
1363 	release_sock(sk);
1364 	return rc;
1365 }
1366 
1367 
1368 static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1369 {
1370 	struct sock *sk = sock->sk;
1371 	struct x25_sock *x25 = x25_sk(sk);
1372 	void __user *argp = (void __user *)arg;
1373 	int rc;
1374 
1375 	switch (cmd) {
1376 	case TIOCOUTQ: {
1377 		int amount;
1378 
1379 		amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1380 		if (amount < 0)
1381 			amount = 0;
1382 		rc = put_user(amount, (unsigned int __user *)argp);
1383 		break;
1384 	}
1385 
1386 	case TIOCINQ: {
1387 		struct sk_buff *skb;
1388 		int amount = 0;
1389 		/*
1390 		 * These two are safe on a single CPU system as
1391 		 * only user tasks fiddle here
1392 		 */
1393 		lock_sock(sk);
1394 		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1395 			amount = skb->len;
1396 		release_sock(sk);
1397 		rc = put_user(amount, (unsigned int __user *)argp);
1398 		break;
1399 	}
1400 
1401 	case SIOCGIFADDR:
1402 	case SIOCSIFADDR:
1403 	case SIOCGIFDSTADDR:
1404 	case SIOCSIFDSTADDR:
1405 	case SIOCGIFBRDADDR:
1406 	case SIOCSIFBRDADDR:
1407 	case SIOCGIFNETMASK:
1408 	case SIOCSIFNETMASK:
1409 	case SIOCGIFMETRIC:
1410 	case SIOCSIFMETRIC:
1411 		rc = -EINVAL;
1412 		break;
1413 	case SIOCADDRT:
1414 	case SIOCDELRT:
1415 		rc = -EPERM;
1416 		if (!capable(CAP_NET_ADMIN))
1417 			break;
1418 		rc = x25_route_ioctl(cmd, argp);
1419 		break;
1420 	case SIOCX25GSUBSCRIP:
1421 		rc = x25_subscr_ioctl(cmd, argp);
1422 		break;
1423 	case SIOCX25SSUBSCRIP:
1424 		rc = -EPERM;
1425 		if (!capable(CAP_NET_ADMIN))
1426 			break;
1427 		rc = x25_subscr_ioctl(cmd, argp);
1428 		break;
1429 	case SIOCX25GFACILITIES: {
1430 		lock_sock(sk);
1431 		rc = copy_to_user(argp, &x25->facilities,
1432 				  sizeof(x25->facilities))
1433 			? -EFAULT : 0;
1434 		release_sock(sk);
1435 		break;
1436 	}
1437 
1438 	case SIOCX25SFACILITIES: {
1439 		struct x25_facilities facilities;
1440 		rc = -EFAULT;
1441 		if (copy_from_user(&facilities, argp, sizeof(facilities)))
1442 			break;
1443 		rc = -EINVAL;
1444 		lock_sock(sk);
1445 		if (sk->sk_state != TCP_LISTEN &&
1446 		    sk->sk_state != TCP_CLOSE)
1447 			goto out_fac_release;
1448 		if (facilities.pacsize_in < X25_PS16 ||
1449 		    facilities.pacsize_in > X25_PS4096)
1450 			goto out_fac_release;
1451 		if (facilities.pacsize_out < X25_PS16 ||
1452 		    facilities.pacsize_out > X25_PS4096)
1453 			goto out_fac_release;
1454 		if (facilities.winsize_in < 1 ||
1455 		    facilities.winsize_in > 127)
1456 			goto out_fac_release;
1457 		if (facilities.throughput) {
1458 			int out = facilities.throughput & 0xf0;
1459 			int in  = facilities.throughput & 0x0f;
1460 			if (!out)
1461 				facilities.throughput |=
1462 					X25_DEFAULT_THROUGHPUT << 4;
1463 			else if (out < 0x30 || out > 0xD0)
1464 				goto out_fac_release;
1465 			if (!in)
1466 				facilities.throughput |=
1467 					X25_DEFAULT_THROUGHPUT;
1468 			else if (in < 0x03 || in > 0x0D)
1469 				goto out_fac_release;
1470 		}
1471 		if (facilities.reverse &&
1472 		    (facilities.reverse & 0x81) != 0x81)
1473 			goto out_fac_release;
1474 		x25->facilities = facilities;
1475 		rc = 0;
1476 out_fac_release:
1477 		release_sock(sk);
1478 		break;
1479 	}
1480 
1481 	case SIOCX25GDTEFACILITIES: {
1482 		lock_sock(sk);
1483 		rc = copy_to_user(argp, &x25->dte_facilities,
1484 				  sizeof(x25->dte_facilities));
1485 		release_sock(sk);
1486 		if (rc)
1487 			rc = -EFAULT;
1488 		break;
1489 	}
1490 
1491 	case SIOCX25SDTEFACILITIES: {
1492 		struct x25_dte_facilities dtefacs;
1493 		rc = -EFAULT;
1494 		if (copy_from_user(&dtefacs, argp, sizeof(dtefacs)))
1495 			break;
1496 		rc = -EINVAL;
1497 		lock_sock(sk);
1498 		if (sk->sk_state != TCP_LISTEN &&
1499 		    sk->sk_state != TCP_CLOSE)
1500 			goto out_dtefac_release;
1501 		if (dtefacs.calling_len > X25_MAX_AE_LEN)
1502 			goto out_dtefac_release;
1503 		if (dtefacs.called_len > X25_MAX_AE_LEN)
1504 			goto out_dtefac_release;
1505 		x25->dte_facilities = dtefacs;
1506 		rc = 0;
1507 out_dtefac_release:
1508 		release_sock(sk);
1509 		break;
1510 	}
1511 
1512 	case SIOCX25GCALLUSERDATA: {
1513 		lock_sock(sk);
1514 		rc = copy_to_user(argp, &x25->calluserdata,
1515 				  sizeof(x25->calluserdata))
1516 			? -EFAULT : 0;
1517 		release_sock(sk);
1518 		break;
1519 	}
1520 
1521 	case SIOCX25SCALLUSERDATA: {
1522 		struct x25_calluserdata calluserdata;
1523 
1524 		rc = -EFAULT;
1525 		if (copy_from_user(&calluserdata, argp, sizeof(calluserdata)))
1526 			break;
1527 		rc = -EINVAL;
1528 		if (calluserdata.cudlength > X25_MAX_CUD_LEN)
1529 			break;
1530 		lock_sock(sk);
1531 		x25->calluserdata = calluserdata;
1532 		release_sock(sk);
1533 		rc = 0;
1534 		break;
1535 	}
1536 
1537 	case SIOCX25GCAUSEDIAG: {
1538 		lock_sock(sk);
1539 		rc = copy_to_user(argp, &x25->causediag, sizeof(x25->causediag))
1540 			? -EFAULT : 0;
1541 		release_sock(sk);
1542 		break;
1543 	}
1544 
1545 	case SIOCX25SCAUSEDIAG: {
1546 		struct x25_causediag causediag;
1547 		rc = -EFAULT;
1548 		if (copy_from_user(&causediag, argp, sizeof(causediag)))
1549 			break;
1550 		lock_sock(sk);
1551 		x25->causediag = causediag;
1552 		release_sock(sk);
1553 		rc = 0;
1554 		break;
1555 
1556 	}
1557 
1558 	case SIOCX25SCUDMATCHLEN: {
1559 		struct x25_subaddr sub_addr;
1560 		rc = -EINVAL;
1561 		lock_sock(sk);
1562 		if(sk->sk_state != TCP_CLOSE)
1563 			goto out_cud_release;
1564 		rc = -EFAULT;
1565 		if (copy_from_user(&sub_addr, argp,
1566 				   sizeof(sub_addr)))
1567 			goto out_cud_release;
1568 		rc = -EINVAL;
1569 		if (sub_addr.cudmatchlength > X25_MAX_CUD_LEN)
1570 			goto out_cud_release;
1571 		x25->cudmatchlength = sub_addr.cudmatchlength;
1572 		rc = 0;
1573 out_cud_release:
1574 		release_sock(sk);
1575 		break;
1576 	}
1577 
1578 	case SIOCX25CALLACCPTAPPRV: {
1579 		rc = -EINVAL;
1580 		lock_sock(sk);
1581 		if (sk->sk_state == TCP_CLOSE) {
1582 			clear_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);
1583 			rc = 0;
1584 		}
1585 		release_sock(sk);
1586 		break;
1587 	}
1588 
1589 	case SIOCX25SENDCALLACCPT:  {
1590 		rc = -EINVAL;
1591 		lock_sock(sk);
1592 		if (sk->sk_state != TCP_ESTABLISHED)
1593 			goto out_sendcallaccpt_release;
1594 		/* must call accptapprv above */
1595 		if (test_bit(X25_ACCPT_APPRV_FLAG, &x25->flags))
1596 			goto out_sendcallaccpt_release;
1597 		x25_write_internal(sk, X25_CALL_ACCEPTED);
1598 		x25->state = X25_STATE_3;
1599 		rc = 0;
1600 out_sendcallaccpt_release:
1601 		release_sock(sk);
1602 		break;
1603 	}
1604 
1605 	default:
1606 		rc = -ENOIOCTLCMD;
1607 		break;
1608 	}
1609 
1610 	return rc;
1611 }
1612 
1613 static const struct net_proto_family x25_family_ops = {
1614 	.family =	AF_X25,
1615 	.create =	x25_create,
1616 	.owner	=	THIS_MODULE,
1617 };
1618 
1619 #ifdef CONFIG_COMPAT
1620 static int compat_x25_subscr_ioctl(unsigned int cmd,
1621 		struct compat_x25_subscrip_struct __user *x25_subscr32)
1622 {
1623 	struct compat_x25_subscrip_struct x25_subscr;
1624 	struct x25_neigh *nb;
1625 	struct net_device *dev;
1626 	int rc = -EINVAL;
1627 
1628 	rc = -EFAULT;
1629 	if (copy_from_user(&x25_subscr, x25_subscr32, sizeof(*x25_subscr32)))
1630 		goto out;
1631 
1632 	rc = -EINVAL;
1633 	dev = x25_dev_get(x25_subscr.device);
1634 	if (dev == NULL)
1635 		goto out;
1636 
1637 	nb = x25_get_neigh(dev);
1638 	if (nb == NULL)
1639 		goto out_dev_put;
1640 
1641 	dev_put(dev);
1642 
1643 	if (cmd == SIOCX25GSUBSCRIP) {
1644 		read_lock_bh(&x25_neigh_list_lock);
1645 		x25_subscr.extended = nb->extended;
1646 		x25_subscr.global_facil_mask = nb->global_facil_mask;
1647 		read_unlock_bh(&x25_neigh_list_lock);
1648 		rc = copy_to_user(x25_subscr32, &x25_subscr,
1649 				sizeof(*x25_subscr32)) ? -EFAULT : 0;
1650 	} else {
1651 		rc = -EINVAL;
1652 		if (x25_subscr.extended == 0 || x25_subscr.extended == 1) {
1653 			rc = 0;
1654 			write_lock_bh(&x25_neigh_list_lock);
1655 			nb->extended = x25_subscr.extended;
1656 			nb->global_facil_mask = x25_subscr.global_facil_mask;
1657 			write_unlock_bh(&x25_neigh_list_lock);
1658 		}
1659 	}
1660 	x25_neigh_put(nb);
1661 out:
1662 	return rc;
1663 out_dev_put:
1664 	dev_put(dev);
1665 	goto out;
1666 }
1667 
1668 static int compat_x25_ioctl(struct socket *sock, unsigned int cmd,
1669 				unsigned long arg)
1670 {
1671 	void __user *argp = compat_ptr(arg);
1672 	int rc = -ENOIOCTLCMD;
1673 
1674 	switch(cmd) {
1675 	case TIOCOUTQ:
1676 	case TIOCINQ:
1677 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1678 		break;
1679 	case SIOCGIFADDR:
1680 	case SIOCSIFADDR:
1681 	case SIOCGIFDSTADDR:
1682 	case SIOCSIFDSTADDR:
1683 	case SIOCGIFBRDADDR:
1684 	case SIOCSIFBRDADDR:
1685 	case SIOCGIFNETMASK:
1686 	case SIOCSIFNETMASK:
1687 	case SIOCGIFMETRIC:
1688 	case SIOCSIFMETRIC:
1689 		rc = -EINVAL;
1690 		break;
1691 	case SIOCADDRT:
1692 	case SIOCDELRT:
1693 		rc = -EPERM;
1694 		if (!capable(CAP_NET_ADMIN))
1695 			break;
1696 		rc = x25_route_ioctl(cmd, argp);
1697 		break;
1698 	case SIOCX25GSUBSCRIP:
1699 		rc = compat_x25_subscr_ioctl(cmd, argp);
1700 		break;
1701 	case SIOCX25SSUBSCRIP:
1702 		rc = -EPERM;
1703 		if (!capable(CAP_NET_ADMIN))
1704 			break;
1705 		rc = compat_x25_subscr_ioctl(cmd, argp);
1706 		break;
1707 	case SIOCX25GFACILITIES:
1708 	case SIOCX25SFACILITIES:
1709 	case SIOCX25GDTEFACILITIES:
1710 	case SIOCX25SDTEFACILITIES:
1711 	case SIOCX25GCALLUSERDATA:
1712 	case SIOCX25SCALLUSERDATA:
1713 	case SIOCX25GCAUSEDIAG:
1714 	case SIOCX25SCAUSEDIAG:
1715 	case SIOCX25SCUDMATCHLEN:
1716 	case SIOCX25CALLACCPTAPPRV:
1717 	case SIOCX25SENDCALLACCPT:
1718 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1719 		break;
1720 	default:
1721 		rc = -ENOIOCTLCMD;
1722 		break;
1723 	}
1724 	return rc;
1725 }
1726 #endif
1727 
1728 static const struct proto_ops x25_proto_ops = {
1729 	.family =	AF_X25,
1730 	.owner =	THIS_MODULE,
1731 	.release =	x25_release,
1732 	.bind =		x25_bind,
1733 	.connect =	x25_connect,
1734 	.socketpair =	sock_no_socketpair,
1735 	.accept =	x25_accept,
1736 	.getname =	x25_getname,
1737 	.poll =		datagram_poll,
1738 	.ioctl =	x25_ioctl,
1739 #ifdef CONFIG_COMPAT
1740 	.compat_ioctl = compat_x25_ioctl,
1741 #endif
1742 	.gettstamp =	sock_gettstamp,
1743 	.listen =	x25_listen,
1744 	.shutdown =	sock_no_shutdown,
1745 	.setsockopt =	x25_setsockopt,
1746 	.getsockopt =	x25_getsockopt,
1747 	.sendmsg =	x25_sendmsg,
1748 	.recvmsg =	x25_recvmsg,
1749 	.mmap =		sock_no_mmap,
1750 	.sendpage =	sock_no_sendpage,
1751 };
1752 
1753 static struct packet_type x25_packet_type __read_mostly = {
1754 	.type =	cpu_to_be16(ETH_P_X25),
1755 	.func =	x25_lapb_receive_frame,
1756 };
1757 
1758 static struct notifier_block x25_dev_notifier = {
1759 	.notifier_call = x25_device_event,
1760 };
1761 
1762 void x25_kill_by_neigh(struct x25_neigh *nb)
1763 {
1764 	struct sock *s;
1765 
1766 	write_lock_bh(&x25_list_lock);
1767 
1768 	sk_for_each(s, &x25_list)
1769 		if (x25_sk(s)->neighbour == nb)
1770 			x25_disconnect(s, ENETUNREACH, 0, 0);
1771 
1772 	write_unlock_bh(&x25_list_lock);
1773 
1774 	/* Remove any related forwards */
1775 	x25_clear_forward_by_dev(nb->dev);
1776 }
1777 
1778 static int __init x25_init(void)
1779 {
1780 	int rc;
1781 
1782 	rc = proto_register(&x25_proto, 0);
1783 	if (rc)
1784 		goto out;
1785 
1786 	rc = sock_register(&x25_family_ops);
1787 	if (rc)
1788 		goto out_proto;
1789 
1790 	dev_add_pack(&x25_packet_type);
1791 
1792 	rc = register_netdevice_notifier(&x25_dev_notifier);
1793 	if (rc)
1794 		goto out_sock;
1795 
1796 	rc = x25_register_sysctl();
1797 	if (rc)
1798 		goto out_dev;
1799 
1800 	rc = x25_proc_init();
1801 	if (rc)
1802 		goto out_sysctl;
1803 
1804 	pr_info("Linux Version 0.2\n");
1805 
1806 out:
1807 	return rc;
1808 out_sysctl:
1809 	x25_unregister_sysctl();
1810 out_dev:
1811 	unregister_netdevice_notifier(&x25_dev_notifier);
1812 out_sock:
1813 	dev_remove_pack(&x25_packet_type);
1814 	sock_unregister(AF_X25);
1815 out_proto:
1816 	proto_unregister(&x25_proto);
1817 	goto out;
1818 }
1819 module_init(x25_init);
1820 
1821 static void __exit x25_exit(void)
1822 {
1823 	x25_proc_exit();
1824 	x25_link_free();
1825 	x25_route_free();
1826 
1827 	x25_unregister_sysctl();
1828 
1829 	unregister_netdevice_notifier(&x25_dev_notifier);
1830 
1831 	dev_remove_pack(&x25_packet_type);
1832 
1833 	sock_unregister(AF_X25);
1834 	proto_unregister(&x25_proto);
1835 }
1836 module_exit(x25_exit);
1837 
1838 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
1839 MODULE_DESCRIPTION("The X.25 Packet Layer network layer protocol");
1840 MODULE_LICENSE("GPL");
1841 MODULE_ALIAS_NETPROTO(PF_X25);
1842