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1 /*
2  *	X.25 Packet Layer release 002
3  *
4  *	This is ALPHA test software. This code may break your machine,
5  *	randomly fail to work with new releases, misbehave and/or generally
6  *	screw up. It might even work.
7  *
8  *	This code REQUIRES 2.1.15 or higher
9  *
10  *	This module:
11  *		This module is free software; you can redistribute it and/or
12  *		modify it under the terms of the GNU General Public License
13  *		as published by the Free Software Foundation; either version
14  *		2 of the License, or (at your option) any later version.
15  *
16  *	History
17  *	X.25 001	Jonathan Naylor	Started coding.
18  *	X.25 002	Jonathan Naylor	Centralised disconnect handling.
19  *					New timer architecture.
20  *	2000-03-11	Henner Eisen	MSG_EOR handling more POSIX compliant.
21  *	2000-03-22	Daniela Squassoni Allowed disabling/enabling of
22  *					  facilities negotiation and increased
23  *					  the throughput upper limit.
24  *	2000-08-27	Arnaldo C. Melo s/suser/capable/ + micro cleanups
25  *	2000-09-04	Henner Eisen	Set sock->state in x25_accept().
26  *					Fixed x25_output() related skb leakage.
27  *	2000-10-02	Henner Eisen	Made x25_kick() single threaded per socket.
28  *	2000-10-27	Henner Eisen    MSG_DONTWAIT for fragment allocation.
29  *	2000-11-14	Henner Eisen    Closing datalink from NETDEV_GOING_DOWN
30  *	2002-10-06	Arnaldo C. Melo Get rid of cli/sti, move proc stuff to
31  *					x25_proc.c, using seq_file
32  *	2005-04-02	Shaun Pereira	Selective sub address matching
33  *					with call user data
34  *	2005-04-15	Shaun Pereira	Fast select with no restriction on
35  *					response
36  */
37 
38 #define pr_fmt(fmt) "X25: " fmt
39 
40 #include <linux/module.h>
41 #include <linux/capability.h>
42 #include <linux/errno.h>
43 #include <linux/kernel.h>
44 #include <linux/sched/signal.h>
45 #include <linux/timer.h>
46 #include <linux/string.h>
47 #include <linux/net.h>
48 #include <linux/netdevice.h>
49 #include <linux/if_arp.h>
50 #include <linux/skbuff.h>
51 #include <linux/slab.h>
52 #include <net/sock.h>
53 #include <net/tcp_states.h>
54 #include <linux/uaccess.h>
55 #include <linux/fcntl.h>
56 #include <linux/termios.h>	/* For TIOCINQ/OUTQ */
57 #include <linux/notifier.h>
58 #include <linux/init.h>
59 #include <linux/compat.h>
60 #include <linux/ctype.h>
61 
62 #include <net/x25.h>
63 #include <net/compat.h>
64 
65 int sysctl_x25_restart_request_timeout = X25_DEFAULT_T20;
66 int sysctl_x25_call_request_timeout    = X25_DEFAULT_T21;
67 int sysctl_x25_reset_request_timeout   = X25_DEFAULT_T22;
68 int sysctl_x25_clear_request_timeout   = X25_DEFAULT_T23;
69 int sysctl_x25_ack_holdback_timeout    = X25_DEFAULT_T2;
70 int sysctl_x25_forward                 = 0;
71 
72 HLIST_HEAD(x25_list);
73 DEFINE_RWLOCK(x25_list_lock);
74 
75 static const struct proto_ops x25_proto_ops;
76 
77 static const struct x25_address null_x25_address = {"               "};
78 
79 #ifdef CONFIG_COMPAT
80 struct compat_x25_subscrip_struct {
81 	char device[200-sizeof(compat_ulong_t)];
82 	compat_ulong_t global_facil_mask;
83 	compat_uint_t extended;
84 };
85 #endif
86 
87 
x25_parse_address_block(struct sk_buff * skb,struct x25_address * called_addr,struct x25_address * calling_addr)88 int x25_parse_address_block(struct sk_buff *skb,
89 		struct x25_address *called_addr,
90 		struct x25_address *calling_addr)
91 {
92 	unsigned char len;
93 	int needed;
94 	int rc;
95 
96 	if (!pskb_may_pull(skb, 1)) {
97 		/* packet has no address block */
98 		rc = 0;
99 		goto empty;
100 	}
101 
102 	len = *skb->data;
103 	needed = 1 + ((len >> 4) + (len & 0x0f) + 1) / 2;
104 
105 	if (!pskb_may_pull(skb, needed)) {
106 		/* packet is too short to hold the addresses it claims
107 		   to hold */
108 		rc = -1;
109 		goto empty;
110 	}
111 
112 	return x25_addr_ntoa(skb->data, called_addr, calling_addr);
113 
114 empty:
115 	*called_addr->x25_addr = 0;
116 	*calling_addr->x25_addr = 0;
117 
118 	return rc;
119 }
120 
121 
x25_addr_ntoa(unsigned char * p,struct x25_address * called_addr,struct x25_address * calling_addr)122 int x25_addr_ntoa(unsigned char *p, struct x25_address *called_addr,
123 		  struct x25_address *calling_addr)
124 {
125 	unsigned int called_len, calling_len;
126 	char *called, *calling;
127 	unsigned int i;
128 
129 	called_len  = (*p >> 0) & 0x0F;
130 	calling_len = (*p >> 4) & 0x0F;
131 
132 	called  = called_addr->x25_addr;
133 	calling = calling_addr->x25_addr;
134 	p++;
135 
136 	for (i = 0; i < (called_len + calling_len); i++) {
137 		if (i < called_len) {
138 			if (i % 2 != 0) {
139 				*called++ = ((*p >> 0) & 0x0F) + '0';
140 				p++;
141 			} else {
142 				*called++ = ((*p >> 4) & 0x0F) + '0';
143 			}
144 		} else {
145 			if (i % 2 != 0) {
146 				*calling++ = ((*p >> 0) & 0x0F) + '0';
147 				p++;
148 			} else {
149 				*calling++ = ((*p >> 4) & 0x0F) + '0';
150 			}
151 		}
152 	}
153 
154 	*called = *calling = '\0';
155 
156 	return 1 + (called_len + calling_len + 1) / 2;
157 }
158 
x25_addr_aton(unsigned char * p,struct x25_address * called_addr,struct x25_address * calling_addr)159 int x25_addr_aton(unsigned char *p, struct x25_address *called_addr,
160 		  struct x25_address *calling_addr)
161 {
162 	unsigned int called_len, calling_len;
163 	char *called, *calling;
164 	int i;
165 
166 	called  = called_addr->x25_addr;
167 	calling = calling_addr->x25_addr;
168 
169 	called_len  = strlen(called);
170 	calling_len = strlen(calling);
171 
172 	*p++ = (calling_len << 4) | (called_len << 0);
173 
174 	for (i = 0; i < (called_len + calling_len); i++) {
175 		if (i < called_len) {
176 			if (i % 2 != 0) {
177 				*p |= (*called++ - '0') << 0;
178 				p++;
179 			} else {
180 				*p = 0x00;
181 				*p |= (*called++ - '0') << 4;
182 			}
183 		} else {
184 			if (i % 2 != 0) {
185 				*p |= (*calling++ - '0') << 0;
186 				p++;
187 			} else {
188 				*p = 0x00;
189 				*p |= (*calling++ - '0') << 4;
190 			}
191 		}
192 	}
193 
194 	return 1 + (called_len + calling_len + 1) / 2;
195 }
196 
197 /*
198  *	Socket removal during an interrupt is now safe.
199  */
x25_remove_socket(struct sock * sk)200 static void x25_remove_socket(struct sock *sk)
201 {
202 	write_lock_bh(&x25_list_lock);
203 	sk_del_node_init(sk);
204 	write_unlock_bh(&x25_list_lock);
205 }
206 
207 /*
208  *	Kill all bound sockets on a dropped device.
209  */
x25_kill_by_device(struct net_device * dev)210 static void x25_kill_by_device(struct net_device *dev)
211 {
212 	struct sock *s;
213 
214 	write_lock_bh(&x25_list_lock);
215 
216 	sk_for_each(s, &x25_list)
217 		if (x25_sk(s)->neighbour && x25_sk(s)->neighbour->dev == dev)
218 			x25_disconnect(s, ENETUNREACH, 0, 0);
219 
220 	write_unlock_bh(&x25_list_lock);
221 }
222 
223 /*
224  *	Handle device status changes.
225  */
x25_device_event(struct notifier_block * this,unsigned long event,void * ptr)226 static int x25_device_event(struct notifier_block *this, unsigned long event,
227 			    void *ptr)
228 {
229 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
230 	struct x25_neigh *nb;
231 
232 	if (!net_eq(dev_net(dev), &init_net))
233 		return NOTIFY_DONE;
234 
235 	if (dev->type == ARPHRD_X25
236 #if IS_ENABLED(CONFIG_LLC)
237 	 || dev->type == ARPHRD_ETHER
238 #endif
239 	 ) {
240 		switch (event) {
241 		case NETDEV_UP:
242 			x25_link_device_up(dev);
243 			break;
244 		case NETDEV_GOING_DOWN:
245 			nb = x25_get_neigh(dev);
246 			if (nb) {
247 				x25_terminate_link(nb);
248 				x25_neigh_put(nb);
249 			}
250 			break;
251 		case NETDEV_DOWN:
252 			x25_kill_by_device(dev);
253 			x25_route_device_down(dev);
254 			x25_link_device_down(dev);
255 			break;
256 		}
257 	}
258 
259 	return NOTIFY_DONE;
260 }
261 
262 /*
263  *	Add a socket to the bound sockets list.
264  */
x25_insert_socket(struct sock * sk)265 static void x25_insert_socket(struct sock *sk)
266 {
267 	write_lock_bh(&x25_list_lock);
268 	sk_add_node(sk, &x25_list);
269 	write_unlock_bh(&x25_list_lock);
270 }
271 
272 /*
273  *	Find a socket that wants to accept the Call Request we just
274  *	received. Check the full list for an address/cud match.
275  *	If no cuds match return the next_best thing, an address match.
276  *	Note: if a listening socket has cud set it must only get calls
277  *	with matching cud.
278  */
x25_find_listener(struct x25_address * addr,struct sk_buff * skb)279 static struct sock *x25_find_listener(struct x25_address *addr,
280 					struct sk_buff *skb)
281 {
282 	struct sock *s;
283 	struct sock *next_best;
284 
285 	read_lock_bh(&x25_list_lock);
286 	next_best = NULL;
287 
288 	sk_for_each(s, &x25_list)
289 		if ((!strcmp(addr->x25_addr,
290 			x25_sk(s)->source_addr.x25_addr) ||
291 				!strcmp(x25_sk(s)->source_addr.x25_addr,
292 					null_x25_address.x25_addr)) &&
293 					s->sk_state == TCP_LISTEN) {
294 			/*
295 			 * Found a listening socket, now check the incoming
296 			 * call user data vs this sockets call user data
297 			 */
298 			if (x25_sk(s)->cudmatchlength > 0 &&
299 				skb->len >= x25_sk(s)->cudmatchlength) {
300 				if((memcmp(x25_sk(s)->calluserdata.cuddata,
301 					skb->data,
302 					x25_sk(s)->cudmatchlength)) == 0) {
303 					sock_hold(s);
304 					goto found;
305 				 }
306 			} else
307 				next_best = s;
308 		}
309 	if (next_best) {
310 		s = next_best;
311 		sock_hold(s);
312 		goto found;
313 	}
314 	s = NULL;
315 found:
316 	read_unlock_bh(&x25_list_lock);
317 	return s;
318 }
319 
320 /*
321  *	Find a connected X.25 socket given my LCI and neighbour.
322  */
__x25_find_socket(unsigned int lci,struct x25_neigh * nb)323 static struct sock *__x25_find_socket(unsigned int lci, struct x25_neigh *nb)
324 {
325 	struct sock *s;
326 
327 	sk_for_each(s, &x25_list)
328 		if (x25_sk(s)->lci == lci && x25_sk(s)->neighbour == nb) {
329 			sock_hold(s);
330 			goto found;
331 		}
332 	s = NULL;
333 found:
334 	return s;
335 }
336 
x25_find_socket(unsigned int lci,struct x25_neigh * nb)337 struct sock *x25_find_socket(unsigned int lci, struct x25_neigh *nb)
338 {
339 	struct sock *s;
340 
341 	read_lock_bh(&x25_list_lock);
342 	s = __x25_find_socket(lci, nb);
343 	read_unlock_bh(&x25_list_lock);
344 	return s;
345 }
346 
347 /*
348  *	Find a unique LCI for a given device.
349  */
x25_new_lci(struct x25_neigh * nb)350 static unsigned int x25_new_lci(struct x25_neigh *nb)
351 {
352 	unsigned int lci = 1;
353 	struct sock *sk;
354 
355 	while ((sk = x25_find_socket(lci, nb)) != NULL) {
356 		sock_put(sk);
357 		if (++lci == 4096) {
358 			lci = 0;
359 			break;
360 		}
361 		cond_resched();
362 	}
363 
364 	return lci;
365 }
366 
367 /*
368  *	Deferred destroy.
369  */
370 static void __x25_destroy_socket(struct sock *);
371 
372 /*
373  *	handler for deferred kills.
374  */
x25_destroy_timer(unsigned long data)375 static void x25_destroy_timer(unsigned long data)
376 {
377 	x25_destroy_socket_from_timer((struct sock *)data);
378 }
379 
380 /*
381  *	This is called from user mode and the timers. Thus it protects itself
382  *	against interrupt users but doesn't worry about being called during
383  *	work. Once it is removed from the queue no interrupt or bottom half
384  *	will touch it and we are (fairly 8-) ) safe.
385  *	Not static as it's used by the timer
386  */
__x25_destroy_socket(struct sock * sk)387 static void __x25_destroy_socket(struct sock *sk)
388 {
389 	struct sk_buff *skb;
390 
391 	x25_stop_heartbeat(sk);
392 	x25_stop_timer(sk);
393 
394 	x25_remove_socket(sk);
395 	x25_clear_queues(sk);		/* Flush the queues */
396 
397 	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
398 		if (skb->sk != sk) {		/* A pending connection */
399 			/*
400 			 * Queue the unaccepted socket for death
401 			 */
402 			skb->sk->sk_state = TCP_LISTEN;
403 			sock_set_flag(skb->sk, SOCK_DEAD);
404 			x25_start_heartbeat(skb->sk);
405 			x25_sk(skb->sk)->state = X25_STATE_0;
406 		}
407 
408 		kfree_skb(skb);
409 	}
410 
411 	if (sk_has_allocations(sk)) {
412 		/* Defer: outstanding buffers */
413 		sk->sk_timer.expires  = jiffies + 10 * HZ;
414 		sk->sk_timer.function = x25_destroy_timer;
415 		sk->sk_timer.data = (unsigned long)sk;
416 		add_timer(&sk->sk_timer);
417 	} else {
418 		/* drop last reference so sock_put will free */
419 		__sock_put(sk);
420 	}
421 }
422 
x25_destroy_socket_from_timer(struct sock * sk)423 void x25_destroy_socket_from_timer(struct sock *sk)
424 {
425 	sock_hold(sk);
426 	bh_lock_sock(sk);
427 	__x25_destroy_socket(sk);
428 	bh_unlock_sock(sk);
429 	sock_put(sk);
430 }
431 
432 /*
433  *	Handling for system calls applied via the various interfaces to a
434  *	X.25 socket object.
435  */
436 
x25_setsockopt(struct socket * sock,int level,int optname,char __user * optval,unsigned int optlen)437 static int x25_setsockopt(struct socket *sock, int level, int optname,
438 			  char __user *optval, unsigned int optlen)
439 {
440 	int opt;
441 	struct sock *sk = sock->sk;
442 	int rc = -ENOPROTOOPT;
443 
444 	if (level != SOL_X25 || optname != X25_QBITINCL)
445 		goto out;
446 
447 	rc = -EINVAL;
448 	if (optlen < sizeof(int))
449 		goto out;
450 
451 	rc = -EFAULT;
452 	if (get_user(opt, (int __user *)optval))
453 		goto out;
454 
455 	if (opt)
456 		set_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
457 	else
458 		clear_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
459 	rc = 0;
460 out:
461 	return rc;
462 }
463 
x25_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)464 static int x25_getsockopt(struct socket *sock, int level, int optname,
465 			  char __user *optval, int __user *optlen)
466 {
467 	struct sock *sk = sock->sk;
468 	int val, len, rc = -ENOPROTOOPT;
469 
470 	if (level != SOL_X25 || optname != X25_QBITINCL)
471 		goto out;
472 
473 	rc = -EFAULT;
474 	if (get_user(len, optlen))
475 		goto out;
476 
477 	len = min_t(unsigned int, len, sizeof(int));
478 
479 	rc = -EINVAL;
480 	if (len < 0)
481 		goto out;
482 
483 	rc = -EFAULT;
484 	if (put_user(len, optlen))
485 		goto out;
486 
487 	val = test_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
488 	rc = copy_to_user(optval, &val, len) ? -EFAULT : 0;
489 out:
490 	return rc;
491 }
492 
x25_listen(struct socket * sock,int backlog)493 static int x25_listen(struct socket *sock, int backlog)
494 {
495 	struct sock *sk = sock->sk;
496 	int rc = -EOPNOTSUPP;
497 
498 	lock_sock(sk);
499 	if (sk->sk_state != TCP_LISTEN) {
500 		memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN);
501 		sk->sk_max_ack_backlog = backlog;
502 		sk->sk_state           = TCP_LISTEN;
503 		rc = 0;
504 	}
505 	release_sock(sk);
506 
507 	return rc;
508 }
509 
510 static struct proto x25_proto = {
511 	.name	  = "X25",
512 	.owner	  = THIS_MODULE,
513 	.obj_size = sizeof(struct x25_sock),
514 };
515 
x25_alloc_socket(struct net * net,int kern)516 static struct sock *x25_alloc_socket(struct net *net, int kern)
517 {
518 	struct x25_sock *x25;
519 	struct sock *sk = sk_alloc(net, AF_X25, GFP_ATOMIC, &x25_proto, kern);
520 
521 	if (!sk)
522 		goto out;
523 
524 	sock_init_data(NULL, sk);
525 
526 	x25 = x25_sk(sk);
527 	skb_queue_head_init(&x25->ack_queue);
528 	skb_queue_head_init(&x25->fragment_queue);
529 	skb_queue_head_init(&x25->interrupt_in_queue);
530 	skb_queue_head_init(&x25->interrupt_out_queue);
531 out:
532 	return sk;
533 }
534 
x25_create(struct net * net,struct socket * sock,int protocol,int kern)535 static int x25_create(struct net *net, struct socket *sock, int protocol,
536 		      int kern)
537 {
538 	struct sock *sk;
539 	struct x25_sock *x25;
540 	int rc = -EAFNOSUPPORT;
541 
542 	if (!net_eq(net, &init_net))
543 		goto out;
544 
545 	rc = -ESOCKTNOSUPPORT;
546 	if (sock->type != SOCK_SEQPACKET)
547 		goto out;
548 
549 	rc = -EINVAL;
550 	if (protocol)
551 		goto out;
552 
553 	rc = -ENOBUFS;
554 	if ((sk = x25_alloc_socket(net, kern)) == NULL)
555 		goto out;
556 
557 	x25 = x25_sk(sk);
558 
559 	sock_init_data(sock, sk);
560 
561 	x25_init_timers(sk);
562 
563 	sock->ops    = &x25_proto_ops;
564 	sk->sk_protocol = protocol;
565 	sk->sk_backlog_rcv = x25_backlog_rcv;
566 
567 	x25->t21   = sysctl_x25_call_request_timeout;
568 	x25->t22   = sysctl_x25_reset_request_timeout;
569 	x25->t23   = sysctl_x25_clear_request_timeout;
570 	x25->t2    = sysctl_x25_ack_holdback_timeout;
571 	x25->state = X25_STATE_0;
572 	x25->cudmatchlength = 0;
573 	set_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);	/* normally no cud  */
574 							/* on call accept   */
575 
576 	x25->facilities.winsize_in  = X25_DEFAULT_WINDOW_SIZE;
577 	x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
578 	x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
579 	x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
580 	x25->facilities.throughput  = 0;	/* by default don't negotiate
581 						   throughput */
582 	x25->facilities.reverse     = X25_DEFAULT_REVERSE;
583 	x25->dte_facilities.calling_len = 0;
584 	x25->dte_facilities.called_len = 0;
585 	memset(x25->dte_facilities.called_ae, '\0',
586 			sizeof(x25->dte_facilities.called_ae));
587 	memset(x25->dte_facilities.calling_ae, '\0',
588 			sizeof(x25->dte_facilities.calling_ae));
589 
590 	rc = 0;
591 out:
592 	return rc;
593 }
594 
x25_make_new(struct sock * osk)595 static struct sock *x25_make_new(struct sock *osk)
596 {
597 	struct sock *sk = NULL;
598 	struct x25_sock *x25, *ox25;
599 
600 	if (osk->sk_type != SOCK_SEQPACKET)
601 		goto out;
602 
603 	if ((sk = x25_alloc_socket(sock_net(osk), 0)) == NULL)
604 		goto out;
605 
606 	x25 = x25_sk(sk);
607 
608 	sk->sk_type        = osk->sk_type;
609 	sk->sk_priority    = osk->sk_priority;
610 	sk->sk_protocol    = osk->sk_protocol;
611 	sk->sk_rcvbuf      = osk->sk_rcvbuf;
612 	sk->sk_sndbuf      = osk->sk_sndbuf;
613 	sk->sk_state       = TCP_ESTABLISHED;
614 	sk->sk_backlog_rcv = osk->sk_backlog_rcv;
615 	sock_copy_flags(sk, osk);
616 
617 	ox25 = x25_sk(osk);
618 	x25->t21        = ox25->t21;
619 	x25->t22        = ox25->t22;
620 	x25->t23        = ox25->t23;
621 	x25->t2         = ox25->t2;
622 	x25->flags	= ox25->flags;
623 	x25->facilities = ox25->facilities;
624 	x25->dte_facilities = ox25->dte_facilities;
625 	x25->cudmatchlength = ox25->cudmatchlength;
626 
627 	clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
628 	x25_init_timers(sk);
629 out:
630 	return sk;
631 }
632 
x25_release(struct socket * sock)633 static int x25_release(struct socket *sock)
634 {
635 	struct sock *sk = sock->sk;
636 	struct x25_sock *x25;
637 
638 	if (!sk)
639 		return 0;
640 
641 	x25 = x25_sk(sk);
642 
643 	sock_hold(sk);
644 	lock_sock(sk);
645 	switch (x25->state) {
646 
647 		case X25_STATE_0:
648 		case X25_STATE_2:
649 			x25_disconnect(sk, 0, 0, 0);
650 			__x25_destroy_socket(sk);
651 			goto out;
652 
653 		case X25_STATE_1:
654 		case X25_STATE_3:
655 		case X25_STATE_4:
656 			x25_clear_queues(sk);
657 			x25_write_internal(sk, X25_CLEAR_REQUEST);
658 			x25_start_t23timer(sk);
659 			x25->state = X25_STATE_2;
660 			sk->sk_state	= TCP_CLOSE;
661 			sk->sk_shutdown	|= SEND_SHUTDOWN;
662 			sk->sk_state_change(sk);
663 			sock_set_flag(sk, SOCK_DEAD);
664 			sock_set_flag(sk, SOCK_DESTROY);
665 			break;
666 	}
667 
668 	sock_orphan(sk);
669 out:
670 	release_sock(sk);
671 	sock_put(sk);
672 	return 0;
673 }
674 
x25_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)675 static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
676 {
677 	struct sock *sk = sock->sk;
678 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
679 	int len, i, rc = 0;
680 
681 	if (addr_len != sizeof(struct sockaddr_x25) ||
682 	    addr->sx25_family != AF_X25) {
683 		rc = -EINVAL;
684 		goto out;
685 	}
686 
687 	/* check for the null_x25_address */
688 	if (strcmp(addr->sx25_addr.x25_addr, null_x25_address.x25_addr)) {
689 
690 		len = strlen(addr->sx25_addr.x25_addr);
691 		for (i = 0; i < len; i++) {
692 			if (!isdigit(addr->sx25_addr.x25_addr[i])) {
693 				rc = -EINVAL;
694 				goto out;
695 			}
696 		}
697 	}
698 
699 	lock_sock(sk);
700 	if (sock_flag(sk, SOCK_ZAPPED)) {
701 		x25_sk(sk)->source_addr = addr->sx25_addr;
702 		x25_insert_socket(sk);
703 		sock_reset_flag(sk, SOCK_ZAPPED);
704 	} else {
705 		rc = -EINVAL;
706 	}
707 	release_sock(sk);
708 	SOCK_DEBUG(sk, "x25_bind: socket is bound\n");
709 out:
710 	return rc;
711 }
712 
x25_wait_for_connection_establishment(struct sock * sk)713 static int x25_wait_for_connection_establishment(struct sock *sk)
714 {
715 	DECLARE_WAITQUEUE(wait, current);
716 	int rc;
717 
718 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
719 	for (;;) {
720 		__set_current_state(TASK_INTERRUPTIBLE);
721 		rc = -ERESTARTSYS;
722 		if (signal_pending(current))
723 			break;
724 		rc = sock_error(sk);
725 		if (rc) {
726 			sk->sk_socket->state = SS_UNCONNECTED;
727 			break;
728 		}
729 		rc = 0;
730 		if (sk->sk_state != TCP_ESTABLISHED) {
731 			release_sock(sk);
732 			schedule();
733 			lock_sock(sk);
734 		} else
735 			break;
736 	}
737 	__set_current_state(TASK_RUNNING);
738 	remove_wait_queue(sk_sleep(sk), &wait);
739 	return rc;
740 }
741 
x25_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)742 static int x25_connect(struct socket *sock, struct sockaddr *uaddr,
743 		       int addr_len, int flags)
744 {
745 	struct sock *sk = sock->sk;
746 	struct x25_sock *x25 = x25_sk(sk);
747 	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
748 	struct x25_route *rt;
749 	int rc = 0;
750 
751 	lock_sock(sk);
752 	if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
753 		sock->state = SS_CONNECTED;
754 		goto out; /* Connect completed during a ERESTARTSYS event */
755 	}
756 
757 	rc = -ECONNREFUSED;
758 	if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
759 		sock->state = SS_UNCONNECTED;
760 		goto out;
761 	}
762 
763 	rc = -EISCONN;	/* No reconnect on a seqpacket socket */
764 	if (sk->sk_state == TCP_ESTABLISHED)
765 		goto out;
766 
767 	rc = -EALREADY;	/* Do nothing if call is already in progress */
768 	if (sk->sk_state == TCP_SYN_SENT)
769 		goto out;
770 
771 	sk->sk_state   = TCP_CLOSE;
772 	sock->state = SS_UNCONNECTED;
773 
774 	rc = -EINVAL;
775 	if (addr_len != sizeof(struct sockaddr_x25) ||
776 	    addr->sx25_family != AF_X25)
777 		goto out;
778 
779 	rc = -ENETUNREACH;
780 	rt = x25_get_route(&addr->sx25_addr);
781 	if (!rt)
782 		goto out;
783 
784 	x25->neighbour = x25_get_neigh(rt->dev);
785 	if (!x25->neighbour)
786 		goto out_put_route;
787 
788 	x25_limit_facilities(&x25->facilities, x25->neighbour);
789 
790 	x25->lci = x25_new_lci(x25->neighbour);
791 	if (!x25->lci)
792 		goto out_put_neigh;
793 
794 	rc = -EINVAL;
795 	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
796 		goto out_put_neigh;
797 
798 	if (!strcmp(x25->source_addr.x25_addr, null_x25_address.x25_addr))
799 		memset(&x25->source_addr, '\0', X25_ADDR_LEN);
800 
801 	x25->dest_addr = addr->sx25_addr;
802 
803 	/* Move to connecting socket, start sending Connect Requests */
804 	sock->state   = SS_CONNECTING;
805 	sk->sk_state  = TCP_SYN_SENT;
806 
807 	x25->state = X25_STATE_1;
808 
809 	x25_write_internal(sk, X25_CALL_REQUEST);
810 
811 	x25_start_heartbeat(sk);
812 	x25_start_t21timer(sk);
813 
814 	/* Now the loop */
815 	rc = -EINPROGRESS;
816 	if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK))
817 		goto out;
818 
819 	rc = x25_wait_for_connection_establishment(sk);
820 	if (rc)
821 		goto out_put_neigh;
822 
823 	sock->state = SS_CONNECTED;
824 	rc = 0;
825 out_put_neigh:
826 	if (rc) {
827 		read_lock_bh(&x25_list_lock);
828 		x25_neigh_put(x25->neighbour);
829 		x25->neighbour = NULL;
830 		read_unlock_bh(&x25_list_lock);
831 		x25->state = X25_STATE_0;
832 	}
833 out_put_route:
834 	x25_route_put(rt);
835 out:
836 	release_sock(sk);
837 	return rc;
838 }
839 
x25_wait_for_data(struct sock * sk,long timeout)840 static int x25_wait_for_data(struct sock *sk, long timeout)
841 {
842 	DECLARE_WAITQUEUE(wait, current);
843 	int rc = 0;
844 
845 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
846 	for (;;) {
847 		__set_current_state(TASK_INTERRUPTIBLE);
848 		if (sk->sk_shutdown & RCV_SHUTDOWN)
849 			break;
850 		rc = -ERESTARTSYS;
851 		if (signal_pending(current))
852 			break;
853 		rc = -EAGAIN;
854 		if (!timeout)
855 			break;
856 		rc = 0;
857 		if (skb_queue_empty(&sk->sk_receive_queue)) {
858 			release_sock(sk);
859 			timeout = schedule_timeout(timeout);
860 			lock_sock(sk);
861 		} else
862 			break;
863 	}
864 	__set_current_state(TASK_RUNNING);
865 	remove_wait_queue(sk_sleep(sk), &wait);
866 	return rc;
867 }
868 
x25_accept(struct socket * sock,struct socket * newsock,int flags,bool kern)869 static int x25_accept(struct socket *sock, struct socket *newsock, int flags,
870 		      bool kern)
871 {
872 	struct sock *sk = sock->sk;
873 	struct sock *newsk;
874 	struct sk_buff *skb;
875 	int rc = -EINVAL;
876 
877 	if (!sk)
878 		goto out;
879 
880 	rc = -EOPNOTSUPP;
881 	if (sk->sk_type != SOCK_SEQPACKET)
882 		goto out;
883 
884 	lock_sock(sk);
885 	rc = -EINVAL;
886 	if (sk->sk_state != TCP_LISTEN)
887 		goto out2;
888 
889 	rc = x25_wait_for_data(sk, sk->sk_rcvtimeo);
890 	if (rc)
891 		goto out2;
892 	skb = skb_dequeue(&sk->sk_receive_queue);
893 	rc = -EINVAL;
894 	if (!skb->sk)
895 		goto out2;
896 	newsk		 = skb->sk;
897 	sock_graft(newsk, newsock);
898 
899 	/* Now attach up the new socket */
900 	skb->sk = NULL;
901 	kfree_skb(skb);
902 	sk->sk_ack_backlog--;
903 	newsock->state = SS_CONNECTED;
904 	rc = 0;
905 out2:
906 	release_sock(sk);
907 out:
908 	return rc;
909 }
910 
x25_getname(struct socket * sock,struct sockaddr * uaddr,int * uaddr_len,int peer)911 static int x25_getname(struct socket *sock, struct sockaddr *uaddr,
912 		       int *uaddr_len, int peer)
913 {
914 	struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)uaddr;
915 	struct sock *sk = sock->sk;
916 	struct x25_sock *x25 = x25_sk(sk);
917 	int rc = 0;
918 
919 	if (peer) {
920 		if (sk->sk_state != TCP_ESTABLISHED) {
921 			rc = -ENOTCONN;
922 			goto out;
923 		}
924 		sx25->sx25_addr = x25->dest_addr;
925 	} else
926 		sx25->sx25_addr = x25->source_addr;
927 
928 	sx25->sx25_family = AF_X25;
929 	*uaddr_len = sizeof(*sx25);
930 
931 out:
932 	return rc;
933 }
934 
x25_rx_call_request(struct sk_buff * skb,struct x25_neigh * nb,unsigned int lci)935 int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
936 			unsigned int lci)
937 {
938 	struct sock *sk;
939 	struct sock *make;
940 	struct x25_sock *makex25;
941 	struct x25_address source_addr, dest_addr;
942 	struct x25_facilities facilities;
943 	struct x25_dte_facilities dte_facilities;
944 	int len, addr_len, rc;
945 
946 	/*
947 	 *	Remove the LCI and frame type.
948 	 */
949 	skb_pull(skb, X25_STD_MIN_LEN);
950 
951 	/*
952 	 *	Extract the X.25 addresses and convert them to ASCII strings,
953 	 *	and remove them.
954 	 *
955 	 *	Address block is mandatory in call request packets
956 	 */
957 	addr_len = x25_parse_address_block(skb, &source_addr, &dest_addr);
958 	if (addr_len <= 0)
959 		goto out_clear_request;
960 	skb_pull(skb, addr_len);
961 
962 	/*
963 	 *	Get the length of the facilities, skip past them for the moment
964 	 *	get the call user data because this is needed to determine
965 	 *	the correct listener
966 	 *
967 	 *	Facilities length is mandatory in call request packets
968 	 */
969 	if (!pskb_may_pull(skb, 1))
970 		goto out_clear_request;
971 	len = skb->data[0] + 1;
972 	if (!pskb_may_pull(skb, len))
973 		goto out_clear_request;
974 	skb_pull(skb,len);
975 
976 	/*
977 	 *	Ensure that the amount of call user data is valid.
978 	 */
979 	if (skb->len > X25_MAX_CUD_LEN)
980 		goto out_clear_request;
981 
982 	/*
983 	 *	Get all the call user data so it can be used in
984 	 *	x25_find_listener and skb_copy_from_linear_data up ahead.
985 	 */
986 	if (!pskb_may_pull(skb, skb->len))
987 		goto out_clear_request;
988 
989 	/*
990 	 *	Find a listener for the particular address/cud pair.
991 	 */
992 	sk = x25_find_listener(&source_addr,skb);
993 	skb_push(skb,len);
994 
995 	if (sk != NULL && sk_acceptq_is_full(sk)) {
996 		goto out_sock_put;
997 	}
998 
999 	/*
1000 	 *	We dont have any listeners for this incoming call.
1001 	 *	Try forwarding it.
1002 	 */
1003 	if (sk == NULL) {
1004 		skb_push(skb, addr_len + X25_STD_MIN_LEN);
1005 		if (sysctl_x25_forward &&
1006 				x25_forward_call(&dest_addr, nb, skb, lci) > 0)
1007 		{
1008 			/* Call was forwarded, dont process it any more */
1009 			kfree_skb(skb);
1010 			rc = 1;
1011 			goto out;
1012 		} else {
1013 			/* No listeners, can't forward, clear the call */
1014 			goto out_clear_request;
1015 		}
1016 	}
1017 
1018 	/*
1019 	 *	Try to reach a compromise on the requested facilities.
1020 	 */
1021 	len = x25_negotiate_facilities(skb, sk, &facilities, &dte_facilities);
1022 	if (len == -1)
1023 		goto out_sock_put;
1024 
1025 	/*
1026 	 * current neighbour/link might impose additional limits
1027 	 * on certain facilties
1028 	 */
1029 
1030 	x25_limit_facilities(&facilities, nb);
1031 
1032 	/*
1033 	 *	Try to create a new socket.
1034 	 */
1035 	make = x25_make_new(sk);
1036 	if (!make)
1037 		goto out_sock_put;
1038 
1039 	/*
1040 	 *	Remove the facilities
1041 	 */
1042 	skb_pull(skb, len);
1043 
1044 	skb->sk     = make;
1045 	make->sk_state = TCP_ESTABLISHED;
1046 
1047 	makex25 = x25_sk(make);
1048 	makex25->lci           = lci;
1049 	makex25->dest_addr     = dest_addr;
1050 	makex25->source_addr   = source_addr;
1051 	makex25->neighbour     = nb;
1052 	makex25->facilities    = facilities;
1053 	makex25->dte_facilities= dte_facilities;
1054 	makex25->vc_facil_mask = x25_sk(sk)->vc_facil_mask;
1055 	/* ensure no reverse facil on accept */
1056 	makex25->vc_facil_mask &= ~X25_MASK_REVERSE;
1057 	/* ensure no calling address extension on accept */
1058 	makex25->vc_facil_mask &= ~X25_MASK_CALLING_AE;
1059 	makex25->cudmatchlength = x25_sk(sk)->cudmatchlength;
1060 
1061 	/* Normally all calls are accepted immediately */
1062 	if (test_bit(X25_ACCPT_APPRV_FLAG, &makex25->flags)) {
1063 		x25_write_internal(make, X25_CALL_ACCEPTED);
1064 		makex25->state = X25_STATE_3;
1065 	}
1066 
1067 	/*
1068 	 *	Incoming Call User Data.
1069 	 */
1070 	skb_copy_from_linear_data(skb, makex25->calluserdata.cuddata, skb->len);
1071 	makex25->calluserdata.cudlength = skb->len;
1072 
1073 	sk->sk_ack_backlog++;
1074 
1075 	x25_insert_socket(make);
1076 
1077 	skb_queue_head(&sk->sk_receive_queue, skb);
1078 
1079 	x25_start_heartbeat(make);
1080 
1081 	if (!sock_flag(sk, SOCK_DEAD))
1082 		sk->sk_data_ready(sk);
1083 	rc = 1;
1084 	sock_put(sk);
1085 out:
1086 	return rc;
1087 out_sock_put:
1088 	sock_put(sk);
1089 out_clear_request:
1090 	rc = 0;
1091 	x25_transmit_clear_request(nb, lci, 0x01);
1092 	goto out;
1093 }
1094 
x25_sendmsg(struct socket * sock,struct msghdr * msg,size_t len)1095 static int x25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1096 {
1097 	struct sock *sk = sock->sk;
1098 	struct x25_sock *x25 = x25_sk(sk);
1099 	DECLARE_SOCKADDR(struct sockaddr_x25 *, usx25, msg->msg_name);
1100 	struct sockaddr_x25 sx25;
1101 	struct sk_buff *skb;
1102 	unsigned char *asmptr;
1103 	int noblock = msg->msg_flags & MSG_DONTWAIT;
1104 	size_t size;
1105 	int qbit = 0, rc = -EINVAL;
1106 
1107 	lock_sock(sk);
1108 	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_OOB|MSG_EOR|MSG_CMSG_COMPAT))
1109 		goto out;
1110 
1111 	/* we currently don't support segmented records at the user interface */
1112 	if (!(msg->msg_flags & (MSG_EOR|MSG_OOB)))
1113 		goto out;
1114 
1115 	rc = -EADDRNOTAVAIL;
1116 	if (sock_flag(sk, SOCK_ZAPPED))
1117 		goto out;
1118 
1119 	rc = -EPIPE;
1120 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
1121 		send_sig(SIGPIPE, current, 0);
1122 		goto out;
1123 	}
1124 
1125 	rc = -ENETUNREACH;
1126 	if (!x25->neighbour)
1127 		goto out;
1128 
1129 	if (usx25) {
1130 		rc = -EINVAL;
1131 		if (msg->msg_namelen < sizeof(sx25))
1132 			goto out;
1133 		memcpy(&sx25, usx25, sizeof(sx25));
1134 		rc = -EISCONN;
1135 		if (strcmp(x25->dest_addr.x25_addr, sx25.sx25_addr.x25_addr))
1136 			goto out;
1137 		rc = -EINVAL;
1138 		if (sx25.sx25_family != AF_X25)
1139 			goto out;
1140 	} else {
1141 		/*
1142 		 *	FIXME 1003.1g - if the socket is like this because
1143 		 *	it has become closed (not started closed) we ought
1144 		 *	to SIGPIPE, EPIPE;
1145 		 */
1146 		rc = -ENOTCONN;
1147 		if (sk->sk_state != TCP_ESTABLISHED)
1148 			goto out;
1149 
1150 		sx25.sx25_family = AF_X25;
1151 		sx25.sx25_addr   = x25->dest_addr;
1152 	}
1153 
1154 	/* Sanity check the packet size */
1155 	if (len > 65535) {
1156 		rc = -EMSGSIZE;
1157 		goto out;
1158 	}
1159 
1160 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: Addresses built.\n");
1161 
1162 	/* Build a packet */
1163 	SOCK_DEBUG(sk, "x25_sendmsg: sendto: building packet.\n");
1164 
1165 	if ((msg->msg_flags & MSG_OOB) && len > 32)
1166 		len = 32;
1167 
1168 	size = len + X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
1169 
1170 	release_sock(sk);
1171 	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
1172 	lock_sock(sk);
1173 	if (!skb)
1174 		goto out;
1175 	X25_SKB_CB(skb)->flags = msg->msg_flags;
1176 
1177 	skb_reserve(skb, X25_MAX_L2_LEN + X25_EXT_MIN_LEN);
1178 
1179 	/*
1180 	 *	Put the data on the end
1181 	 */
1182 	SOCK_DEBUG(sk, "x25_sendmsg: Copying user data\n");
1183 
1184 	skb_reset_transport_header(skb);
1185 	skb_put(skb, len);
1186 
1187 	rc = memcpy_from_msg(skb_transport_header(skb), msg, len);
1188 	if (rc)
1189 		goto out_kfree_skb;
1190 
1191 	/*
1192 	 *	If the Q BIT Include socket option is in force, the first
1193 	 *	byte of the user data is the logical value of the Q Bit.
1194 	 */
1195 	if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1196 		if (!pskb_may_pull(skb, 1))
1197 			goto out_kfree_skb;
1198 
1199 		qbit = skb->data[0];
1200 		skb_pull(skb, 1);
1201 	}
1202 
1203 	/*
1204 	 *	Push down the X.25 header
1205 	 */
1206 	SOCK_DEBUG(sk, "x25_sendmsg: Building X.25 Header.\n");
1207 
1208 	if (msg->msg_flags & MSG_OOB) {
1209 		if (x25->neighbour->extended) {
1210 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1211 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1212 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1213 			*asmptr++ = X25_INTERRUPT;
1214 		} else {
1215 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1216 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1217 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1218 			*asmptr++ = X25_INTERRUPT;
1219 		}
1220 	} else {
1221 		if (x25->neighbour->extended) {
1222 			/* Build an Extended X.25 header */
1223 			asmptr    = skb_push(skb, X25_EXT_MIN_LEN);
1224 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1225 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1226 			*asmptr++ = X25_DATA;
1227 			*asmptr++ = X25_DATA;
1228 		} else {
1229 			/* Build an Standard X.25 header */
1230 			asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1231 			*asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1232 			*asmptr++ = (x25->lci >> 0) & 0xFF;
1233 			*asmptr++ = X25_DATA;
1234 		}
1235 
1236 		if (qbit)
1237 			skb->data[0] |= X25_Q_BIT;
1238 	}
1239 
1240 	SOCK_DEBUG(sk, "x25_sendmsg: Built header.\n");
1241 	SOCK_DEBUG(sk, "x25_sendmsg: Transmitting buffer\n");
1242 
1243 	rc = -ENOTCONN;
1244 	if (sk->sk_state != TCP_ESTABLISHED)
1245 		goto out_kfree_skb;
1246 
1247 	if (msg->msg_flags & MSG_OOB)
1248 		skb_queue_tail(&x25->interrupt_out_queue, skb);
1249 	else {
1250 		rc = x25_output(sk, skb);
1251 		len = rc;
1252 		if (rc < 0)
1253 			kfree_skb(skb);
1254 		else if (test_bit(X25_Q_BIT_FLAG, &x25->flags))
1255 			len++;
1256 	}
1257 
1258 	x25_kick(sk);
1259 	rc = len;
1260 out:
1261 	release_sock(sk);
1262 	return rc;
1263 out_kfree_skb:
1264 	kfree_skb(skb);
1265 	goto out;
1266 }
1267 
1268 
x25_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)1269 static int x25_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1270 		       int flags)
1271 {
1272 	struct sock *sk = sock->sk;
1273 	struct x25_sock *x25 = x25_sk(sk);
1274 	DECLARE_SOCKADDR(struct sockaddr_x25 *, sx25, msg->msg_name);
1275 	size_t copied;
1276 	int qbit, header_len;
1277 	struct sk_buff *skb;
1278 	unsigned char *asmptr;
1279 	int rc = -ENOTCONN;
1280 
1281 	lock_sock(sk);
1282 
1283 	if (x25->neighbour == NULL)
1284 		goto out;
1285 
1286 	header_len = x25->neighbour->extended ?
1287 		X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
1288 
1289 	/*
1290 	 * This works for seqpacket too. The receiver has ordered the queue for
1291 	 * us! We do one quick check first though
1292 	 */
1293 	if (sk->sk_state != TCP_ESTABLISHED)
1294 		goto out;
1295 
1296 	if (flags & MSG_OOB) {
1297 		rc = -EINVAL;
1298 		if (sock_flag(sk, SOCK_URGINLINE) ||
1299 		    !skb_peek(&x25->interrupt_in_queue))
1300 			goto out;
1301 
1302 		skb = skb_dequeue(&x25->interrupt_in_queue);
1303 
1304 		if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
1305 			goto out_free_dgram;
1306 
1307 		skb_pull(skb, X25_STD_MIN_LEN);
1308 
1309 		/*
1310 		 *	No Q bit information on Interrupt data.
1311 		 */
1312 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1313 			asmptr  = skb_push(skb, 1);
1314 			*asmptr = 0x00;
1315 		}
1316 
1317 		msg->msg_flags |= MSG_OOB;
1318 	} else {
1319 		/* Now we can treat all alike */
1320 		release_sock(sk);
1321 		skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1322 					flags & MSG_DONTWAIT, &rc);
1323 		lock_sock(sk);
1324 		if (!skb)
1325 			goto out;
1326 
1327 		if (!pskb_may_pull(skb, header_len))
1328 			goto out_free_dgram;
1329 
1330 		qbit = (skb->data[0] & X25_Q_BIT) == X25_Q_BIT;
1331 
1332 		skb_pull(skb, header_len);
1333 
1334 		if (test_bit(X25_Q_BIT_FLAG, &x25->flags)) {
1335 			asmptr  = skb_push(skb, 1);
1336 			*asmptr = qbit;
1337 		}
1338 	}
1339 
1340 	skb_reset_transport_header(skb);
1341 	copied = skb->len;
1342 
1343 	if (copied > size) {
1344 		copied = size;
1345 		msg->msg_flags |= MSG_TRUNC;
1346 	}
1347 
1348 	/* Currently, each datagram always contains a complete record */
1349 	msg->msg_flags |= MSG_EOR;
1350 
1351 	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
1352 	if (rc)
1353 		goto out_free_dgram;
1354 
1355 	if (sx25) {
1356 		sx25->sx25_family = AF_X25;
1357 		sx25->sx25_addr   = x25->dest_addr;
1358 		msg->msg_namelen = sizeof(*sx25);
1359 	}
1360 
1361 	x25_check_rbuf(sk);
1362 	rc = copied;
1363 out_free_dgram:
1364 	skb_free_datagram(sk, skb);
1365 out:
1366 	release_sock(sk);
1367 	return rc;
1368 }
1369 
1370 
x25_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1371 static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1372 {
1373 	struct sock *sk = sock->sk;
1374 	struct x25_sock *x25 = x25_sk(sk);
1375 	void __user *argp = (void __user *)arg;
1376 	int rc;
1377 
1378 	switch (cmd) {
1379 	case TIOCOUTQ: {
1380 		int amount;
1381 
1382 		amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1383 		if (amount < 0)
1384 			amount = 0;
1385 		rc = put_user(amount, (unsigned int __user *)argp);
1386 		break;
1387 	}
1388 
1389 	case TIOCINQ: {
1390 		struct sk_buff *skb;
1391 		int amount = 0;
1392 		/*
1393 		 * These two are safe on a single CPU system as
1394 		 * only user tasks fiddle here
1395 		 */
1396 		lock_sock(sk);
1397 		if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1398 			amount = skb->len;
1399 		release_sock(sk);
1400 		rc = put_user(amount, (unsigned int __user *)argp);
1401 		break;
1402 	}
1403 
1404 	case SIOCGSTAMP:
1405 		rc = -EINVAL;
1406 		if (sk)
1407 			rc = sock_get_timestamp(sk,
1408 						(struct timeval __user *)argp);
1409 		break;
1410 	case SIOCGSTAMPNS:
1411 		rc = -EINVAL;
1412 		if (sk)
1413 			rc = sock_get_timestampns(sk,
1414 					(struct timespec __user *)argp);
1415 		break;
1416 	case SIOCGIFADDR:
1417 	case SIOCSIFADDR:
1418 	case SIOCGIFDSTADDR:
1419 	case SIOCSIFDSTADDR:
1420 	case SIOCGIFBRDADDR:
1421 	case SIOCSIFBRDADDR:
1422 	case SIOCGIFNETMASK:
1423 	case SIOCSIFNETMASK:
1424 	case SIOCGIFMETRIC:
1425 	case SIOCSIFMETRIC:
1426 		rc = -EINVAL;
1427 		break;
1428 	case SIOCADDRT:
1429 	case SIOCDELRT:
1430 		rc = -EPERM;
1431 		if (!capable(CAP_NET_ADMIN))
1432 			break;
1433 		rc = x25_route_ioctl(cmd, argp);
1434 		break;
1435 	case SIOCX25GSUBSCRIP:
1436 		rc = x25_subscr_ioctl(cmd, argp);
1437 		break;
1438 	case SIOCX25SSUBSCRIP:
1439 		rc = -EPERM;
1440 		if (!capable(CAP_NET_ADMIN))
1441 			break;
1442 		rc = x25_subscr_ioctl(cmd, argp);
1443 		break;
1444 	case SIOCX25GFACILITIES: {
1445 		lock_sock(sk);
1446 		rc = copy_to_user(argp, &x25->facilities,
1447 				  sizeof(x25->facilities))
1448 			? -EFAULT : 0;
1449 		release_sock(sk);
1450 		break;
1451 	}
1452 
1453 	case SIOCX25SFACILITIES: {
1454 		struct x25_facilities facilities;
1455 		rc = -EFAULT;
1456 		if (copy_from_user(&facilities, argp, sizeof(facilities)))
1457 			break;
1458 		rc = -EINVAL;
1459 		lock_sock(sk);
1460 		if (sk->sk_state != TCP_LISTEN &&
1461 		    sk->sk_state != TCP_CLOSE)
1462 			goto out_fac_release;
1463 		if (facilities.pacsize_in < X25_PS16 ||
1464 		    facilities.pacsize_in > X25_PS4096)
1465 			goto out_fac_release;
1466 		if (facilities.pacsize_out < X25_PS16 ||
1467 		    facilities.pacsize_out > X25_PS4096)
1468 			goto out_fac_release;
1469 		if (facilities.winsize_in < 1 ||
1470 		    facilities.winsize_in > 127)
1471 			goto out_fac_release;
1472 		if (facilities.throughput) {
1473 			int out = facilities.throughput & 0xf0;
1474 			int in  = facilities.throughput & 0x0f;
1475 			if (!out)
1476 				facilities.throughput |=
1477 					X25_DEFAULT_THROUGHPUT << 4;
1478 			else if (out < 0x30 || out > 0xD0)
1479 				goto out_fac_release;
1480 			if (!in)
1481 				facilities.throughput |=
1482 					X25_DEFAULT_THROUGHPUT;
1483 			else if (in < 0x03 || in > 0x0D)
1484 				goto out_fac_release;
1485 		}
1486 		if (facilities.reverse &&
1487 		    (facilities.reverse & 0x81) != 0x81)
1488 			goto out_fac_release;
1489 		x25->facilities = facilities;
1490 		rc = 0;
1491 out_fac_release:
1492 		release_sock(sk);
1493 		break;
1494 	}
1495 
1496 	case SIOCX25GDTEFACILITIES: {
1497 		lock_sock(sk);
1498 		rc = copy_to_user(argp, &x25->dte_facilities,
1499 				  sizeof(x25->dte_facilities));
1500 		release_sock(sk);
1501 		if (rc)
1502 			rc = -EFAULT;
1503 		break;
1504 	}
1505 
1506 	case SIOCX25SDTEFACILITIES: {
1507 		struct x25_dte_facilities dtefacs;
1508 		rc = -EFAULT;
1509 		if (copy_from_user(&dtefacs, argp, sizeof(dtefacs)))
1510 			break;
1511 		rc = -EINVAL;
1512 		lock_sock(sk);
1513 		if (sk->sk_state != TCP_LISTEN &&
1514 		    sk->sk_state != TCP_CLOSE)
1515 			goto out_dtefac_release;
1516 		if (dtefacs.calling_len > X25_MAX_AE_LEN)
1517 			goto out_dtefac_release;
1518 		if (dtefacs.called_len > X25_MAX_AE_LEN)
1519 			goto out_dtefac_release;
1520 		x25->dte_facilities = dtefacs;
1521 		rc = 0;
1522 out_dtefac_release:
1523 		release_sock(sk);
1524 		break;
1525 	}
1526 
1527 	case SIOCX25GCALLUSERDATA: {
1528 		lock_sock(sk);
1529 		rc = copy_to_user(argp, &x25->calluserdata,
1530 				  sizeof(x25->calluserdata))
1531 			? -EFAULT : 0;
1532 		release_sock(sk);
1533 		break;
1534 	}
1535 
1536 	case SIOCX25SCALLUSERDATA: {
1537 		struct x25_calluserdata calluserdata;
1538 
1539 		rc = -EFAULT;
1540 		if (copy_from_user(&calluserdata, argp, sizeof(calluserdata)))
1541 			break;
1542 		rc = -EINVAL;
1543 		if (calluserdata.cudlength > X25_MAX_CUD_LEN)
1544 			break;
1545 		lock_sock(sk);
1546 		x25->calluserdata = calluserdata;
1547 		release_sock(sk);
1548 		rc = 0;
1549 		break;
1550 	}
1551 
1552 	case SIOCX25GCAUSEDIAG: {
1553 		lock_sock(sk);
1554 		rc = copy_to_user(argp, &x25->causediag, sizeof(x25->causediag))
1555 			? -EFAULT : 0;
1556 		release_sock(sk);
1557 		break;
1558 	}
1559 
1560 	case SIOCX25SCAUSEDIAG: {
1561 		struct x25_causediag causediag;
1562 		rc = -EFAULT;
1563 		if (copy_from_user(&causediag, argp, sizeof(causediag)))
1564 			break;
1565 		lock_sock(sk);
1566 		x25->causediag = causediag;
1567 		release_sock(sk);
1568 		rc = 0;
1569 		break;
1570 
1571 	}
1572 
1573 	case SIOCX25SCUDMATCHLEN: {
1574 		struct x25_subaddr sub_addr;
1575 		rc = -EINVAL;
1576 		lock_sock(sk);
1577 		if(sk->sk_state != TCP_CLOSE)
1578 			goto out_cud_release;
1579 		rc = -EFAULT;
1580 		if (copy_from_user(&sub_addr, argp,
1581 				   sizeof(sub_addr)))
1582 			goto out_cud_release;
1583 		rc = -EINVAL;
1584 		if (sub_addr.cudmatchlength > X25_MAX_CUD_LEN)
1585 			goto out_cud_release;
1586 		x25->cudmatchlength = sub_addr.cudmatchlength;
1587 		rc = 0;
1588 out_cud_release:
1589 		release_sock(sk);
1590 		break;
1591 	}
1592 
1593 	case SIOCX25CALLACCPTAPPRV: {
1594 		rc = -EINVAL;
1595 		lock_sock(sk);
1596 		if (sk->sk_state == TCP_CLOSE) {
1597 			clear_bit(X25_ACCPT_APPRV_FLAG, &x25->flags);
1598 			rc = 0;
1599 		}
1600 		release_sock(sk);
1601 		break;
1602 	}
1603 
1604 	case SIOCX25SENDCALLACCPT:  {
1605 		rc = -EINVAL;
1606 		lock_sock(sk);
1607 		if (sk->sk_state != TCP_ESTABLISHED)
1608 			goto out_sendcallaccpt_release;
1609 		/* must call accptapprv above */
1610 		if (test_bit(X25_ACCPT_APPRV_FLAG, &x25->flags))
1611 			goto out_sendcallaccpt_release;
1612 		x25_write_internal(sk, X25_CALL_ACCEPTED);
1613 		x25->state = X25_STATE_3;
1614 		rc = 0;
1615 out_sendcallaccpt_release:
1616 		release_sock(sk);
1617 		break;
1618 	}
1619 
1620 	default:
1621 		rc = -ENOIOCTLCMD;
1622 		break;
1623 	}
1624 
1625 	return rc;
1626 }
1627 
1628 static const struct net_proto_family x25_family_ops = {
1629 	.family =	AF_X25,
1630 	.create =	x25_create,
1631 	.owner	=	THIS_MODULE,
1632 };
1633 
1634 #ifdef CONFIG_COMPAT
compat_x25_subscr_ioctl(unsigned int cmd,struct compat_x25_subscrip_struct __user * x25_subscr32)1635 static int compat_x25_subscr_ioctl(unsigned int cmd,
1636 		struct compat_x25_subscrip_struct __user *x25_subscr32)
1637 {
1638 	struct compat_x25_subscrip_struct x25_subscr;
1639 	struct x25_neigh *nb;
1640 	struct net_device *dev;
1641 	int rc = -EINVAL;
1642 
1643 	rc = -EFAULT;
1644 	if (copy_from_user(&x25_subscr, x25_subscr32, sizeof(*x25_subscr32)))
1645 		goto out;
1646 
1647 	rc = -EINVAL;
1648 	dev = x25_dev_get(x25_subscr.device);
1649 	if (dev == NULL)
1650 		goto out;
1651 
1652 	nb = x25_get_neigh(dev);
1653 	if (nb == NULL)
1654 		goto out_dev_put;
1655 
1656 	dev_put(dev);
1657 
1658 	if (cmd == SIOCX25GSUBSCRIP) {
1659 		read_lock_bh(&x25_neigh_list_lock);
1660 		x25_subscr.extended = nb->extended;
1661 		x25_subscr.global_facil_mask = nb->global_facil_mask;
1662 		read_unlock_bh(&x25_neigh_list_lock);
1663 		rc = copy_to_user(x25_subscr32, &x25_subscr,
1664 				sizeof(*x25_subscr32)) ? -EFAULT : 0;
1665 	} else {
1666 		rc = -EINVAL;
1667 		if (x25_subscr.extended == 0 || x25_subscr.extended == 1) {
1668 			rc = 0;
1669 			write_lock_bh(&x25_neigh_list_lock);
1670 			nb->extended = x25_subscr.extended;
1671 			nb->global_facil_mask = x25_subscr.global_facil_mask;
1672 			write_unlock_bh(&x25_neigh_list_lock);
1673 		}
1674 	}
1675 	x25_neigh_put(nb);
1676 out:
1677 	return rc;
1678 out_dev_put:
1679 	dev_put(dev);
1680 	goto out;
1681 }
1682 
compat_x25_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1683 static int compat_x25_ioctl(struct socket *sock, unsigned int cmd,
1684 				unsigned long arg)
1685 {
1686 	void __user *argp = compat_ptr(arg);
1687 	struct sock *sk = sock->sk;
1688 
1689 	int rc = -ENOIOCTLCMD;
1690 
1691 	switch(cmd) {
1692 	case TIOCOUTQ:
1693 	case TIOCINQ:
1694 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1695 		break;
1696 	case SIOCGSTAMP:
1697 		rc = -EINVAL;
1698 		if (sk)
1699 			rc = compat_sock_get_timestamp(sk,
1700 					(struct timeval __user*)argp);
1701 		break;
1702 	case SIOCGSTAMPNS:
1703 		rc = -EINVAL;
1704 		if (sk)
1705 			rc = compat_sock_get_timestampns(sk,
1706 					(struct timespec __user*)argp);
1707 		break;
1708 	case SIOCGIFADDR:
1709 	case SIOCSIFADDR:
1710 	case SIOCGIFDSTADDR:
1711 	case SIOCSIFDSTADDR:
1712 	case SIOCGIFBRDADDR:
1713 	case SIOCSIFBRDADDR:
1714 	case SIOCGIFNETMASK:
1715 	case SIOCSIFNETMASK:
1716 	case SIOCGIFMETRIC:
1717 	case SIOCSIFMETRIC:
1718 		rc = -EINVAL;
1719 		break;
1720 	case SIOCADDRT:
1721 	case SIOCDELRT:
1722 		rc = -EPERM;
1723 		if (!capable(CAP_NET_ADMIN))
1724 			break;
1725 		rc = x25_route_ioctl(cmd, argp);
1726 		break;
1727 	case SIOCX25GSUBSCRIP:
1728 		rc = compat_x25_subscr_ioctl(cmd, argp);
1729 		break;
1730 	case SIOCX25SSUBSCRIP:
1731 		rc = -EPERM;
1732 		if (!capable(CAP_NET_ADMIN))
1733 			break;
1734 		rc = compat_x25_subscr_ioctl(cmd, argp);
1735 		break;
1736 	case SIOCX25GFACILITIES:
1737 	case SIOCX25SFACILITIES:
1738 	case SIOCX25GDTEFACILITIES:
1739 	case SIOCX25SDTEFACILITIES:
1740 	case SIOCX25GCALLUSERDATA:
1741 	case SIOCX25SCALLUSERDATA:
1742 	case SIOCX25GCAUSEDIAG:
1743 	case SIOCX25SCAUSEDIAG:
1744 	case SIOCX25SCUDMATCHLEN:
1745 	case SIOCX25CALLACCPTAPPRV:
1746 	case SIOCX25SENDCALLACCPT:
1747 		rc = x25_ioctl(sock, cmd, (unsigned long)argp);
1748 		break;
1749 	default:
1750 		rc = -ENOIOCTLCMD;
1751 		break;
1752 	}
1753 	return rc;
1754 }
1755 #endif
1756 
1757 static const struct proto_ops x25_proto_ops = {
1758 	.family =	AF_X25,
1759 	.owner =	THIS_MODULE,
1760 	.release =	x25_release,
1761 	.bind =		x25_bind,
1762 	.connect =	x25_connect,
1763 	.socketpair =	sock_no_socketpair,
1764 	.accept =	x25_accept,
1765 	.getname =	x25_getname,
1766 	.poll =		datagram_poll,
1767 	.ioctl =	x25_ioctl,
1768 #ifdef CONFIG_COMPAT
1769 	.compat_ioctl = compat_x25_ioctl,
1770 #endif
1771 	.listen =	x25_listen,
1772 	.shutdown =	sock_no_shutdown,
1773 	.setsockopt =	x25_setsockopt,
1774 	.getsockopt =	x25_getsockopt,
1775 	.sendmsg =	x25_sendmsg,
1776 	.recvmsg =	x25_recvmsg,
1777 	.mmap =		sock_no_mmap,
1778 	.sendpage =	sock_no_sendpage,
1779 };
1780 
1781 static struct packet_type x25_packet_type __read_mostly = {
1782 	.type =	cpu_to_be16(ETH_P_X25),
1783 	.func =	x25_lapb_receive_frame,
1784 };
1785 
1786 static struct notifier_block x25_dev_notifier = {
1787 	.notifier_call = x25_device_event,
1788 };
1789 
x25_kill_by_neigh(struct x25_neigh * nb)1790 void x25_kill_by_neigh(struct x25_neigh *nb)
1791 {
1792 	struct sock *s;
1793 
1794 	write_lock_bh(&x25_list_lock);
1795 
1796 	sk_for_each(s, &x25_list)
1797 		if (x25_sk(s)->neighbour == nb)
1798 			x25_disconnect(s, ENETUNREACH, 0, 0);
1799 
1800 	write_unlock_bh(&x25_list_lock);
1801 
1802 	/* Remove any related forwards */
1803 	x25_clear_forward_by_dev(nb->dev);
1804 }
1805 
x25_init(void)1806 static int __init x25_init(void)
1807 {
1808 	int rc;
1809 
1810 	rc = proto_register(&x25_proto, 0);
1811 	if (rc)
1812 		goto out;
1813 
1814 	rc = sock_register(&x25_family_ops);
1815 	if (rc)
1816 		goto out_proto;
1817 
1818 	dev_add_pack(&x25_packet_type);
1819 
1820 	rc = register_netdevice_notifier(&x25_dev_notifier);
1821 	if (rc)
1822 		goto out_sock;
1823 
1824 	rc = x25_register_sysctl();
1825 	if (rc)
1826 		goto out_dev;
1827 
1828 	rc = x25_proc_init();
1829 	if (rc)
1830 		goto out_sysctl;
1831 
1832 	pr_info("Linux Version 0.2\n");
1833 
1834 out:
1835 	return rc;
1836 out_sysctl:
1837 	x25_unregister_sysctl();
1838 out_dev:
1839 	unregister_netdevice_notifier(&x25_dev_notifier);
1840 out_sock:
1841 	dev_remove_pack(&x25_packet_type);
1842 	sock_unregister(AF_X25);
1843 out_proto:
1844 	proto_unregister(&x25_proto);
1845 	goto out;
1846 }
1847 module_init(x25_init);
1848 
x25_exit(void)1849 static void __exit x25_exit(void)
1850 {
1851 	x25_proc_exit();
1852 	x25_link_free();
1853 	x25_route_free();
1854 
1855 	x25_unregister_sysctl();
1856 
1857 	unregister_netdevice_notifier(&x25_dev_notifier);
1858 
1859 	dev_remove_pack(&x25_packet_type);
1860 
1861 	sock_unregister(AF_X25);
1862 	proto_unregister(&x25_proto);
1863 }
1864 module_exit(x25_exit);
1865 
1866 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
1867 MODULE_DESCRIPTION("The X.25 Packet Layer network layer protocol");
1868 MODULE_LICENSE("GPL");
1869 MODULE_ALIAS_NETPROTO(PF_X25);
1870