vserver 1.9.3
[linux-2.6.git] / net / x25 / af_x25.c
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  */
33
34 #include <linux/config.h>
35 #include <linux/module.h>
36 #include <linux/errno.h>
37 #include <linux/types.h>
38 #include <linux/socket.h>
39 #include <linux/in.h>
40 #include <linux/kernel.h>
41 #include <linux/sched.h>
42 #include <linux/timer.h>
43 #include <linux/string.h>
44 #include <linux/sockios.h>
45 #include <linux/net.h>
46 #include <linux/stat.h>
47 #include <linux/inet.h>
48 #include <linux/netdevice.h>
49 #include <linux/if_arp.h>
50 #include <linux/skbuff.h>
51 #include <net/sock.h>
52 #include <net/tcp.h>
53 #include <asm/system.h>
54 #include <asm/uaccess.h>
55 #include <linux/fcntl.h>
56 #include <linux/termios.h>      /* For TIOCINQ/OUTQ */
57 #include <linux/mm.h>
58 #include <linux/interrupt.h>
59 #include <linux/notifier.h>
60 #include <linux/init.h>
61 #include <net/x25.h>
62
63 int sysctl_x25_restart_request_timeout = X25_DEFAULT_T20;
64 int sysctl_x25_call_request_timeout    = X25_DEFAULT_T21;
65 int sysctl_x25_reset_request_timeout   = X25_DEFAULT_T22;
66 int sysctl_x25_clear_request_timeout   = X25_DEFAULT_T23;
67 int sysctl_x25_ack_holdback_timeout    = X25_DEFAULT_T2;
68
69 HLIST_HEAD(x25_list);
70 rwlock_t x25_list_lock = RW_LOCK_UNLOCKED;
71
72 static struct proto_ops x25_proto_ops;
73
74 static struct x25_address null_x25_address = {"               "};
75
76 int x25_addr_ntoa(unsigned char *p, struct x25_address *called_addr,
77                   struct x25_address *calling_addr)
78 {
79         int called_len, calling_len;
80         char *called, *calling;
81         int i;
82
83         called_len  = (*p >> 0) & 0x0F;
84         calling_len = (*p >> 4) & 0x0F;
85
86         called  = called_addr->x25_addr;
87         calling = calling_addr->x25_addr;
88         p++;
89
90         for (i = 0; i < (called_len + calling_len); i++) {
91                 if (i < called_len) {
92                         if (i % 2 != 0) {
93                                 *called++ = ((*p >> 0) & 0x0F) + '0';
94                                 p++;
95                         } else {
96                                 *called++ = ((*p >> 4) & 0x0F) + '0';
97                         }
98                 } else {
99                         if (i % 2 != 0) {
100                                 *calling++ = ((*p >> 0) & 0x0F) + '0';
101                                 p++;
102                         } else {
103                                 *calling++ = ((*p >> 4) & 0x0F) + '0';
104                         }
105                 }
106         }
107
108         *called = *calling = '\0';
109
110         return 1 + (called_len + calling_len + 1) / 2;
111 }
112
113 int x25_addr_aton(unsigned char *p, struct x25_address *called_addr,
114                   struct x25_address *calling_addr)
115 {
116         unsigned int called_len, calling_len;
117         char *called, *calling;
118         int i;
119
120         called  = called_addr->x25_addr;
121         calling = calling_addr->x25_addr;
122
123         called_len  = strlen(called);
124         calling_len = strlen(calling);
125
126         *p++ = (calling_len << 4) | (called_len << 0);
127
128         for (i = 0; i < (called_len + calling_len); i++) {
129                 if (i < called_len) {
130                         if (i % 2 != 0) {
131                                 *p |= (*called++ - '0') << 0;
132                                 p++;
133                         } else {
134                                 *p = 0x00;
135                                 *p |= (*called++ - '0') << 4;
136                         }
137                 } else {
138                         if (i % 2 != 0) {
139                                 *p |= (*calling++ - '0') << 0;
140                                 p++;
141                         } else {
142                                 *p = 0x00;
143                                 *p |= (*calling++ - '0') << 4;
144                         }
145                 }
146         }
147
148         return 1 + (called_len + calling_len + 1) / 2;
149 }
150
151 /*
152  *      Socket removal during an interrupt is now safe.
153  */
154 static void x25_remove_socket(struct sock *sk)
155 {
156         write_lock_bh(&x25_list_lock);
157         sk_del_node_init(sk);
158         write_unlock_bh(&x25_list_lock);
159 }
160
161 /*
162  *      Kill all bound sockets on a dropped device.
163  */
164 static void x25_kill_by_device(struct net_device *dev)
165 {
166         struct sock *s;
167         struct hlist_node *node;
168
169         write_lock_bh(&x25_list_lock);
170
171         sk_for_each(s, node, &x25_list)
172                 if (x25_sk(s)->neighbour && x25_sk(s)->neighbour->dev == dev)
173                         x25_disconnect(s, ENETUNREACH, 0, 0);
174
175         write_unlock_bh(&x25_list_lock);
176 }
177
178 /*
179  *      Handle device status changes.
180  */
181 static int x25_device_event(struct notifier_block *this, unsigned long event,
182                             void *ptr)
183 {
184         struct net_device *dev = ptr;
185         struct x25_neigh *nb;
186
187         if (dev->type == ARPHRD_X25
188 #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
189          || dev->type == ARPHRD_ETHER
190 #endif
191          ) {
192                 switch (event) {
193                         case NETDEV_UP:
194                                 x25_link_device_up(dev);
195                                 break;
196                         case NETDEV_GOING_DOWN:
197                                 nb = x25_get_neigh(dev);
198                                 if (nb) {
199                                         x25_terminate_link(nb);
200                                         x25_neigh_put(nb);
201                                 }
202                                 break;
203                         case NETDEV_DOWN:
204                                 x25_kill_by_device(dev);
205                                 x25_route_device_down(dev);
206                                 x25_link_device_down(dev);
207                                 break;
208                 }
209         }
210
211         return NOTIFY_DONE;
212 }
213
214 /*
215  *      Add a socket to the bound sockets list.
216  */
217 static void x25_insert_socket(struct sock *sk)
218 {
219         write_lock_bh(&x25_list_lock);
220         sk_add_node(sk, &x25_list);
221         write_unlock_bh(&x25_list_lock);
222 }
223
224 /*
225  *      Find a socket that wants to accept the Call Request we just
226  *      received.
227  */
228 static struct sock *x25_find_listener(struct x25_address *addr)
229 {
230         struct sock *s;
231         struct hlist_node *node;
232
233         read_lock_bh(&x25_list_lock);
234
235         sk_for_each(s, node, &x25_list)
236                 if ((!strcmp(addr->x25_addr,
237                              x25_sk(s)->source_addr.x25_addr) ||
238                      !strcmp(addr->x25_addr,
239                              null_x25_address.x25_addr)) &&
240                      s->sk_state == TCP_LISTEN) {
241                         sock_hold(s);
242                         goto found;
243                 }
244         s = NULL;
245 found:
246         read_unlock_bh(&x25_list_lock);
247         return s;
248 }
249
250 /*
251  *      Find a connected X.25 socket given my LCI and neighbour.
252  */
253 struct sock *__x25_find_socket(unsigned int lci, struct x25_neigh *nb)
254 {
255         struct sock *s;
256         struct hlist_node *node;
257
258         sk_for_each(s, node, &x25_list)
259                 if (x25_sk(s)->lci == lci && x25_sk(s)->neighbour == nb) {
260                         sock_hold(s);
261                         goto found;
262                 }
263         s = NULL;
264 found:
265         return s;
266 }
267
268 struct sock *x25_find_socket(unsigned int lci, struct x25_neigh *nb)
269 {
270         struct sock *s;
271
272         read_lock_bh(&x25_list_lock);
273         s = __x25_find_socket(lci, nb);
274         read_unlock_bh(&x25_list_lock);
275         return s;
276 }
277
278 /*
279  *      Find a unique LCI for a given device.
280  */
281 unsigned int x25_new_lci(struct x25_neigh *nb)
282 {
283         unsigned int lci = 1;
284         struct sock *sk;
285
286         read_lock_bh(&x25_list_lock);
287
288         while ((sk = __x25_find_socket(lci, nb)) != NULL) {
289                 sock_put(sk);
290                 if (++lci == 4096) {
291                         lci = 0;
292                         break;
293                 }
294         }
295
296         read_unlock_bh(&x25_list_lock);
297         return lci;
298 }
299
300 /*
301  *      Deferred destroy.
302  */
303 void x25_destroy_socket(struct sock *);
304
305 /*
306  *      handler for deferred kills.
307  */
308 static void x25_destroy_timer(unsigned long data)
309 {
310         x25_destroy_socket((struct sock *)data);
311 }
312
313 /*
314  *      This is called from user mode and the timers. Thus it protects itself
315  *      against interrupt users but doesn't worry about being called during
316  *      work. Once it is removed from the queue no interrupt or bottom half
317  *      will touch it and we are (fairly 8-) ) safe.
318  *      Not static as it's used by the timer
319  */
320 void x25_destroy_socket(struct sock *sk)
321 {
322         struct sk_buff *skb;
323
324         sock_hold(sk);
325         lock_sock(sk);
326         x25_stop_heartbeat(sk);
327         x25_stop_timer(sk);
328
329         x25_remove_socket(sk);
330         x25_clear_queues(sk);           /* Flush the queues */
331
332         while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
333                 if (skb->sk != sk) {            /* A pending connection */
334                         /*
335                          * Queue the unaccepted socket for death
336                          */
337                         sock_set_flag(skb->sk, SOCK_DEAD);
338                         x25_start_heartbeat(skb->sk);
339                         x25_sk(skb->sk)->state = X25_STATE_0;
340                 }
341
342                 kfree_skb(skb);
343         }
344
345         if (atomic_read(&sk->sk_wmem_alloc) ||
346             atomic_read(&sk->sk_rmem_alloc)) {
347                 /* Defer: outstanding buffers */
348                 sk->sk_timer.expires  = jiffies + 10 * HZ;
349                 sk->sk_timer.function = x25_destroy_timer;
350                 add_timer(&sk->sk_timer);
351         } else {
352                 /* drop last reference so sock_put will free */
353                 __sock_put(sk);
354         }
355
356         release_sock(sk);
357         sock_put(sk);
358 }
359
360 /*
361  *      Handling for system calls applied via the various interfaces to a
362  *      X.25 socket object.
363  */
364
365 static int x25_setsockopt(struct socket *sock, int level, int optname,
366                           char __user *optval, int optlen)
367 {
368         int opt;
369         struct sock *sk = sock->sk;
370         int rc = -ENOPROTOOPT;
371
372         if (level != SOL_X25 || optname != X25_QBITINCL)
373                 goto out;
374
375         rc = -EINVAL;
376         if (optlen < sizeof(int))
377                 goto out;
378
379         rc = -EFAULT;
380         if (get_user(opt, (int __user *)optval))
381                 goto out;
382
383         x25_sk(sk)->qbitincl = !!opt;
384         rc = 0;
385 out:
386         return rc;
387 }
388
389 static int x25_getsockopt(struct socket *sock, int level, int optname,
390                           char __user *optval, int __user *optlen)
391 {
392         struct sock *sk = sock->sk;
393         int val, len, rc = -ENOPROTOOPT;
394         
395         if (level != SOL_X25 || optname != X25_QBITINCL)
396                 goto out;
397
398         rc = -EFAULT;
399         if (get_user(len, optlen))
400                 goto out;
401
402         len = min_t(unsigned int, len, sizeof(int));
403
404         rc = -EINVAL;
405         if (len < 0)
406                 goto out;
407                 
408         rc = -EFAULT;
409         if (put_user(len, optlen))
410                 goto out;
411
412         val = x25_sk(sk)->qbitincl;
413         rc = copy_to_user(optval, &val, len) ? -EFAULT : 0;
414 out:
415         return rc;
416 }
417
418 static int x25_listen(struct socket *sock, int backlog)
419 {
420         struct sock *sk = sock->sk;
421         int rc = -EOPNOTSUPP;
422
423         if (sk->sk_state != TCP_LISTEN) {
424                 memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN);
425                 sk->sk_max_ack_backlog = backlog;
426                 sk->sk_state           = TCP_LISTEN;
427                 rc = 0;
428         }
429
430         return rc;
431 }
432
433 static struct sock *x25_alloc_socket(void)
434 {
435         struct x25_opt *x25;
436         struct sock *sk = sk_alloc(AF_X25, GFP_ATOMIC, 1, NULL);
437
438         if (!sk)
439                 goto out;
440
441         x25 = sk->sk_protinfo = kmalloc(sizeof(*x25), GFP_ATOMIC);
442         if (!x25)
443                 goto frees;
444
445         memset(x25, 0, sizeof(*x25));
446
447         x25->sk = sk;
448
449         sock_init_data(NULL, sk);
450         sk_set_owner(sk, THIS_MODULE);
451
452         skb_queue_head_init(&x25->ack_queue);
453         skb_queue_head_init(&x25->fragment_queue);
454         skb_queue_head_init(&x25->interrupt_in_queue);
455         skb_queue_head_init(&x25->interrupt_out_queue);
456 out:
457         return sk;
458 frees:
459         sk_free(sk);
460         sk = NULL;
461         goto out;
462 }
463
464 void x25_init_timers(struct sock *sk);
465
466 static int x25_create(struct socket *sock, int protocol)
467 {
468         struct sock *sk;
469         struct x25_opt *x25;
470         int rc = -ESOCKTNOSUPPORT;
471
472         if (sock->type != SOCK_SEQPACKET || protocol)
473                 goto out;
474
475         rc = -ENOMEM;
476         if ((sk = x25_alloc_socket()) == NULL)
477                 goto out;
478
479         x25 = x25_sk(sk);
480
481         sock_init_data(sock, sk);
482         sk_set_owner(sk, THIS_MODULE);
483
484         x25_init_timers(sk);
485
486         sock->ops    = &x25_proto_ops;
487         sk->sk_protocol = protocol;
488         sk->sk_backlog_rcv = x25_backlog_rcv;
489
490         x25->t21   = sysctl_x25_call_request_timeout;
491         x25->t22   = sysctl_x25_reset_request_timeout;
492         x25->t23   = sysctl_x25_clear_request_timeout;
493         x25->t2    = sysctl_x25_ack_holdback_timeout;
494         x25->state = X25_STATE_0;
495
496         x25->facilities.winsize_in  = X25_DEFAULT_WINDOW_SIZE;
497         x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
498         x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
499         x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
500         x25->facilities.throughput  = X25_DEFAULT_THROUGHPUT;
501         x25->facilities.reverse     = X25_DEFAULT_REVERSE;
502         rc = 0;
503 out:
504         return rc;
505 }
506
507 static struct sock *x25_make_new(struct sock *osk)
508 {
509         struct sock *sk = NULL;
510         struct x25_opt *x25, *ox25;
511
512         if (osk->sk_type != SOCK_SEQPACKET)
513                 goto out;
514
515         if ((sk = x25_alloc_socket()) == NULL)
516                 goto out;
517
518         x25 = x25_sk(sk);
519
520         sk->sk_type        = osk->sk_type;
521         sk->sk_socket      = osk->sk_socket;
522         sk->sk_priority    = osk->sk_priority;
523         sk->sk_protocol    = osk->sk_protocol;
524         sk->sk_rcvbuf      = osk->sk_rcvbuf;
525         sk->sk_sndbuf      = osk->sk_sndbuf;
526         sk->sk_debug       = osk->sk_debug;
527         sk->sk_state       = TCP_ESTABLISHED;
528         sk->sk_sleep       = osk->sk_sleep;
529         sk->sk_zapped      = osk->sk_zapped;
530         sk->sk_backlog_rcv = osk->sk_backlog_rcv;
531
532         ox25 = x25_sk(osk);
533         x25->t21        = ox25->t21;
534         x25->t22        = ox25->t22;
535         x25->t23        = ox25->t23;
536         x25->t2         = ox25->t2;
537         x25->facilities = ox25->facilities;
538         x25->qbitincl   = ox25->qbitincl;
539
540         x25_init_timers(sk);
541 out:
542         return sk;
543 }
544
545 static int x25_release(struct socket *sock)
546 {
547         struct sock *sk = sock->sk;
548         struct x25_opt *x25;
549
550         if (!sk)
551                 goto out;
552
553         x25 = x25_sk(sk);
554
555         switch (x25->state) {
556
557                 case X25_STATE_0:
558                 case X25_STATE_2:
559                         x25_disconnect(sk, 0, 0, 0);
560                         x25_destroy_socket(sk);
561                         goto out;
562
563                 case X25_STATE_1:
564                 case X25_STATE_3:
565                 case X25_STATE_4:
566                         x25_clear_queues(sk);
567                         x25_write_internal(sk, X25_CLEAR_REQUEST);
568                         x25_start_t23timer(sk);
569                         x25->state = X25_STATE_2;
570                         sk->sk_state    = TCP_CLOSE;
571                         sk->sk_shutdown |= SEND_SHUTDOWN;
572                         sk->sk_state_change(sk);
573                         sock_set_flag(sk, SOCK_DEAD);
574                         sock_set_flag(sk, SOCK_DESTROY);
575                         break;
576         }
577
578         sock->sk        = NULL; 
579         sk->sk_socket   = NULL; /* Not used, but we should do this */
580 out:
581         return 0;
582 }
583
584 static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
585 {
586         struct sock *sk = sock->sk;
587         struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
588
589         if (!sk->sk_zapped ||
590             addr_len != sizeof(struct sockaddr_x25) ||
591             addr->sx25_family != AF_X25)
592                 return -EINVAL;
593
594         x25_sk(sk)->source_addr = addr->sx25_addr;
595         x25_insert_socket(sk);
596         sk->sk_zapped = 0;
597         SOCK_DEBUG(sk, "x25_bind: socket is bound\n");
598
599         return 0;
600 }
601
602 static int x25_wait_for_connection_establishment(struct sock *sk)
603 {
604         DECLARE_WAITQUEUE(wait, current);
605         int rc;
606
607         add_wait_queue_exclusive(sk->sk_sleep, &wait);
608         for (;;) {
609                 __set_current_state(TASK_INTERRUPTIBLE);
610                 rc = -ERESTARTSYS;
611                 if (signal_pending(current))
612                         break;
613                 rc = sock_error(sk);
614                 if (rc) {
615                         sk->sk_socket->state = SS_UNCONNECTED;
616                         break;
617                 }
618                 rc = 0;
619                 if (sk->sk_state != TCP_ESTABLISHED) {
620                         release_sock(sk);
621                         schedule();
622                         lock_sock(sk);
623                 } else
624                         break;
625         }
626         __set_current_state(TASK_RUNNING);
627         remove_wait_queue(sk->sk_sleep, &wait);
628         return rc;
629 }
630
631 static int x25_connect(struct socket *sock, struct sockaddr *uaddr,
632                        int addr_len, int flags)
633 {
634         struct sock *sk = sock->sk;
635         struct x25_opt *x25 = x25_sk(sk);
636         struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
637         struct x25_route *rt;
638         int rc = 0;
639
640         lock_sock(sk);
641         if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
642                 sock->state = SS_CONNECTED;
643                 goto out; /* Connect completed during a ERESTARTSYS event */
644         }
645
646         rc = -ECONNREFUSED;
647         if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
648                 sock->state = SS_UNCONNECTED;
649                 goto out;
650         }
651
652         rc = -EISCONN;  /* No reconnect on a seqpacket socket */
653         if (sk->sk_state == TCP_ESTABLISHED)
654                 goto out;
655
656         sk->sk_state   = TCP_CLOSE;     
657         sock->state = SS_UNCONNECTED;
658
659         rc = -EINVAL;
660         if (addr_len != sizeof(struct sockaddr_x25) ||
661             addr->sx25_family != AF_X25)
662                 goto out;
663
664         rc = -ENETUNREACH;
665         rt = x25_get_route(&addr->sx25_addr);
666         if (!rt)
667                 goto out;
668
669         x25->neighbour = x25_get_neigh(rt->dev);
670         if (!x25->neighbour)
671                 goto out_put_route;
672
673         x25_limit_facilities(&x25->facilities, x25->neighbour);
674
675         x25->lci = x25_new_lci(x25->neighbour);
676         if (!x25->lci)
677                 goto out_put_neigh;
678
679         rc = -EINVAL;
680         if (sk->sk_zapped) /* Must bind first - autobinding does not work */
681                 goto out_put_neigh;
682
683         if (!strcmp(x25->source_addr.x25_addr, null_x25_address.x25_addr))
684                 memset(&x25->source_addr, '\0', X25_ADDR_LEN);
685
686         x25->dest_addr = addr->sx25_addr;
687
688         /* Move to connecting socket, start sending Connect Requests */
689         sock->state   = SS_CONNECTING;
690         sk->sk_state  = TCP_SYN_SENT;
691
692         x25->state = X25_STATE_1;
693
694         x25_write_internal(sk, X25_CALL_REQUEST);
695
696         x25_start_heartbeat(sk);
697         x25_start_t21timer(sk);
698
699         /* Now the loop */
700         rc = -EINPROGRESS;
701         if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK))
702                 goto out_put_neigh;
703
704         rc = x25_wait_for_connection_establishment(sk);
705         if (rc)
706                 goto out_put_neigh;
707
708         sock->state = SS_CONNECTED;
709         rc = 0;
710 out_put_neigh:
711         if (rc)
712                 x25_neigh_put(x25->neighbour);
713 out_put_route:
714         x25_route_put(rt);
715 out:
716         release_sock(sk);
717         return rc;
718 }
719
720 static int x25_wait_for_data(struct sock *sk, int timeout)
721 {
722         DECLARE_WAITQUEUE(wait, current);
723         int rc = 0;
724
725         add_wait_queue_exclusive(sk->sk_sleep, &wait);
726         for (;;) {
727                 __set_current_state(TASK_INTERRUPTIBLE);
728                 if (sk->sk_shutdown & RCV_SHUTDOWN)
729                         break;
730                 rc = -ERESTARTSYS;
731                 if (signal_pending(current))
732                         break;
733                 rc = -EAGAIN;
734                 if (!timeout)
735                         break;
736                 rc = 0;
737                 if (skb_queue_empty(&sk->sk_receive_queue)) {
738                         release_sock(sk);
739                         timeout = schedule_timeout(timeout);
740                         lock_sock(sk);
741                 } else
742                         break;
743         }
744         __set_current_state(TASK_RUNNING);
745         remove_wait_queue(sk->sk_sleep, &wait);
746         return rc;
747 }
748         
749 static int x25_accept(struct socket *sock, struct socket *newsock, int flags)
750 {
751         struct sock *sk = sock->sk;
752         struct sock *newsk;
753         struct sk_buff *skb;
754         int rc = -EINVAL;
755
756         if (!sk || sk->sk_state != TCP_LISTEN)
757                 goto out;
758
759         rc = -EOPNOTSUPP;
760         if (sk->sk_type != SOCK_SEQPACKET)
761                 goto out;
762
763         lock_sock(sk);
764         rc = x25_wait_for_data(sk, sk->sk_rcvtimeo);
765         if (rc)
766                 goto out2;
767         skb = skb_dequeue(&sk->sk_receive_queue);
768         rc = -EINVAL;
769         if (!skb->sk)
770                 goto out2;
771         newsk            = skb->sk;
772         newsk->sk_socket = newsock;
773         newsk->sk_sleep  = &newsock->wait;
774
775         /* Now attach up the new socket */
776         skb->sk = NULL;
777         kfree_skb(skb);
778         sk->sk_ack_backlog--;
779         newsock->sk    = newsk;
780         newsock->state = SS_CONNECTED;
781         rc = 0;
782 out2:
783         release_sock(sk);
784 out:
785         return rc;
786 }
787
788 static int x25_getname(struct socket *sock, struct sockaddr *uaddr,
789                        int *uaddr_len, int peer)
790 {
791         struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)uaddr;
792         struct sock *sk = sock->sk;
793         struct x25_opt *x25 = x25_sk(sk);
794
795         if (peer) {
796                 if (sk->sk_state != TCP_ESTABLISHED)
797                         return -ENOTCONN;
798                 sx25->sx25_addr = x25->dest_addr;
799         } else
800                 sx25->sx25_addr = x25->source_addr;
801
802         sx25->sx25_family = AF_X25;
803         *uaddr_len = sizeof(*sx25);
804
805         return 0;
806 }
807  
808 int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
809                         unsigned int lci)
810 {
811         struct sock *sk;
812         struct sock *make;
813         struct x25_opt *makex25;
814         struct x25_address source_addr, dest_addr;
815         struct x25_facilities facilities;
816         int len, rc;
817
818         /*
819          *      Remove the LCI and frame type.
820          */
821         skb_pull(skb, X25_STD_MIN_LEN);
822
823         /*
824          *      Extract the X.25 addresses and convert them to ASCII strings,
825          *      and remove them.
826          */
827         skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr));
828
829         /*
830          *      Find a listener for the particular address.
831          */
832         sk = x25_find_listener(&source_addr);
833
834         /*
835          *      We can't accept the Call Request.
836          */
837         if (!sk || sk->sk_ack_backlog == sk->sk_max_ack_backlog)
838                 goto out_clear_request;
839
840         /*
841          *      Try to reach a compromise on the requested facilities.
842          */
843         if ((len = x25_negotiate_facilities(skb, sk, &facilities)) == -1)
844                 goto out_sock_put;
845
846         /*
847          * current neighbour/link might impose additional limits
848          * on certain facilties
849          */
850
851         x25_limit_facilities(&facilities, nb);
852
853         /*
854          *      Try to create a new socket.
855          */
856         make = x25_make_new(sk);
857         if (!make)
858                 goto out_sock_put;
859
860         /*
861          *      Remove the facilities, leaving any Call User Data.
862          */
863         skb_pull(skb, len);
864
865         skb->sk     = make;
866         make->sk_state = TCP_ESTABLISHED;
867
868         makex25 = x25_sk(make);
869         makex25->lci           = lci;
870         makex25->dest_addr     = dest_addr;
871         makex25->source_addr   = source_addr;
872         makex25->neighbour     = nb;
873         makex25->facilities    = facilities;
874         makex25->vc_facil_mask = x25_sk(sk)->vc_facil_mask;
875
876         x25_write_internal(make, X25_CALL_ACCEPTED);
877
878         /*
879          *      Incoming Call User Data.
880          */
881         if (skb->len >= 0) {
882                 memcpy(makex25->calluserdata.cuddata, skb->data, skb->len);
883                 makex25->calluserdata.cudlength = skb->len;
884         }
885
886         makex25->state = X25_STATE_3;
887
888         sk->sk_ack_backlog++;
889
890         x25_insert_socket(make);
891
892         skb_queue_head(&sk->sk_receive_queue, skb);
893
894         x25_start_heartbeat(make);
895
896         if (!sock_flag(sk, SOCK_DEAD))
897                 sk->sk_data_ready(sk, skb->len);
898         rc = 1;
899         sock_put(sk);
900 out:
901         return rc;
902 out_sock_put:
903         sock_put(sk);
904 out_clear_request:
905         rc = 0;
906         x25_transmit_clear_request(nb, lci, 0x01);
907         goto out;
908 }
909
910 static int x25_sendmsg(struct kiocb *iocb, struct socket *sock,
911                        struct msghdr *msg, size_t len)
912 {
913         struct sock *sk = sock->sk;
914         struct x25_opt *x25 = x25_sk(sk);
915         struct sockaddr_x25 *usx25 = (struct sockaddr_x25 *)msg->msg_name;
916         struct sockaddr_x25 sx25;
917         struct sk_buff *skb;
918         unsigned char *asmptr;
919         int noblock = msg->msg_flags & MSG_DONTWAIT;
920         size_t size;
921         int qbit = 0, rc = -EINVAL;
922
923         if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_OOB|MSG_EOR|MSG_CMSG_COMPAT))
924                 goto out;
925
926         /* we currently don't support segmented records at the user interface */
927         if (!(msg->msg_flags & (MSG_EOR|MSG_OOB)))
928                 goto out;
929
930         rc = -EADDRNOTAVAIL;
931         if (sk->sk_zapped)
932                 goto out;
933
934         rc = -EPIPE;
935         if (sk->sk_shutdown & SEND_SHUTDOWN) {
936                 send_sig(SIGPIPE, current, 0);
937                 goto out;
938         }
939
940         rc = -ENETUNREACH;
941         if (!x25->neighbour)
942                 goto out;
943
944         if (usx25) {
945                 rc = -EINVAL;
946                 if (msg->msg_namelen < sizeof(sx25))
947                         goto out;
948                 memcpy(&sx25, usx25, sizeof(sx25));
949                 rc = -EISCONN;
950                 if (strcmp(x25->dest_addr.x25_addr, sx25.sx25_addr.x25_addr))
951                         goto out;
952                 rc = -EINVAL;
953                 if (sx25.sx25_family != AF_X25)
954                         goto out;
955         } else {
956                 /*
957                  *      FIXME 1003.1g - if the socket is like this because
958                  *      it has become closed (not started closed) we ought
959                  *      to SIGPIPE, EPIPE;
960                  */
961                 rc = -ENOTCONN;
962                 if (sk->sk_state != TCP_ESTABLISHED)
963                         goto out;
964
965                 sx25.sx25_family = AF_X25;
966                 sx25.sx25_addr   = x25->dest_addr;
967         }
968
969         SOCK_DEBUG(sk, "x25_sendmsg: sendto: Addresses built.\n");
970
971         /* Build a packet */
972         SOCK_DEBUG(sk, "x25_sendmsg: sendto: building packet.\n");
973
974         if ((msg->msg_flags & MSG_OOB) && len > 32)
975                 len = 32;
976
977         size = len + X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
978
979         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
980         if (!skb)
981                 goto out;
982         X25_SKB_CB(skb)->flags = msg->msg_flags;
983
984         skb_reserve(skb, X25_MAX_L2_LEN + X25_EXT_MIN_LEN);
985
986         /*
987          *      Put the data on the end
988          */
989         SOCK_DEBUG(sk, "x25_sendmsg: Copying user data\n");
990
991         asmptr = skb->h.raw = skb_put(skb, len);
992
993         rc = memcpy_fromiovec(asmptr, msg->msg_iov, len);
994         if (rc)
995                 goto out_kfree_skb;
996
997         /*
998          *      If the Q BIT Include socket option is in force, the first
999          *      byte of the user data is the logical value of the Q Bit.
1000          */
1001         if (x25->qbitincl) {
1002                 qbit = skb->data[0];
1003                 skb_pull(skb, 1);
1004         }
1005
1006         /*
1007          *      Push down the X.25 header
1008          */
1009         SOCK_DEBUG(sk, "x25_sendmsg: Building X.25 Header.\n");
1010
1011         if (msg->msg_flags & MSG_OOB) {
1012                 if (x25->neighbour->extended) {
1013                         asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1014                         *asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1015                         *asmptr++ = (x25->lci >> 0) & 0xFF;
1016                         *asmptr++ = X25_INTERRUPT;
1017                 } else {
1018                         asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1019                         *asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1020                         *asmptr++ = (x25->lci >> 0) & 0xFF;
1021                         *asmptr++ = X25_INTERRUPT;
1022                 }
1023         } else {
1024                 if (x25->neighbour->extended) {
1025                         /* Build an Extended X.25 header */
1026                         asmptr    = skb_push(skb, X25_EXT_MIN_LEN);
1027                         *asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_EXTSEQ;
1028                         *asmptr++ = (x25->lci >> 0) & 0xFF;
1029                         *asmptr++ = X25_DATA;
1030                         *asmptr++ = X25_DATA;
1031                 } else {
1032                         /* Build an Standard X.25 header */
1033                         asmptr    = skb_push(skb, X25_STD_MIN_LEN);
1034                         *asmptr++ = ((x25->lci >> 8) & 0x0F) | X25_GFI_STDSEQ;
1035                         *asmptr++ = (x25->lci >> 0) & 0xFF;
1036                         *asmptr++ = X25_DATA;
1037                 }
1038
1039                 if (qbit)
1040                         skb->data[0] |= X25_Q_BIT;
1041         }
1042
1043         SOCK_DEBUG(sk, "x25_sendmsg: Built header.\n");
1044         SOCK_DEBUG(sk, "x25_sendmsg: Transmitting buffer\n");
1045
1046         rc = -ENOTCONN;
1047         if (sk->sk_state != TCP_ESTABLISHED)
1048                 goto out_kfree_skb;
1049
1050         if (msg->msg_flags & MSG_OOB)
1051                 skb_queue_tail(&x25->interrupt_out_queue, skb);
1052         else {
1053                 len = x25_output(sk, skb);
1054                 if (len < 0)
1055                         kfree_skb(skb);
1056                 else if (x25->qbitincl)
1057                         len++;
1058         }
1059
1060         /*
1061          * lock_sock() is currently only used to serialize this x25_kick()
1062          * against input-driven x25_kick() calls. It currently only blocks
1063          * incoming packets for this socket and does not protect against
1064          * any other socket state changes and is not called from anywhere
1065          * else. As x25_kick() cannot block and as long as all socket
1066          * operations are BKL-wrapped, we don't need take to care about
1067          * purging the backlog queue in x25_release().
1068          *
1069          * Using lock_sock() to protect all socket operations entirely
1070          * (and making the whole x25 stack SMP aware) unfortunately would
1071          * require major changes to {send,recv}msg and skb allocation methods.
1072          * -> 2.5 ;)
1073          */
1074         lock_sock(sk);
1075         x25_kick(sk);
1076         release_sock(sk);
1077         rc = len;
1078 out:
1079         return rc;
1080 out_kfree_skb:
1081         kfree_skb(skb);
1082         goto out;
1083 }
1084
1085
1086 static int x25_recvmsg(struct kiocb *iocb, struct socket *sock,
1087                        struct msghdr *msg, size_t size,
1088                        int flags)
1089 {
1090         struct sock *sk = sock->sk;
1091         struct x25_opt *x25 = x25_sk(sk);
1092         struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)msg->msg_name;
1093         size_t copied;
1094         int qbit;
1095         struct sk_buff *skb;
1096         unsigned char *asmptr;
1097         int rc = -ENOTCONN;
1098
1099         /*
1100          * This works for seqpacket too. The receiver has ordered the queue for
1101          * us! We do one quick check first though
1102          */
1103         if (sk->sk_state != TCP_ESTABLISHED)
1104                 goto out;
1105
1106         if (flags & MSG_OOB) {
1107                 rc = -EINVAL;
1108                 if (sock_flag(sk, SOCK_URGINLINE) ||
1109                     !skb_peek(&x25->interrupt_in_queue))
1110                         goto out;
1111
1112                 skb = skb_dequeue(&x25->interrupt_in_queue);
1113
1114                 skb_pull(skb, X25_STD_MIN_LEN);
1115
1116                 /*
1117                  *      No Q bit information on Interrupt data.
1118                  */
1119                 if (x25->qbitincl) {
1120                         asmptr  = skb_push(skb, 1);
1121                         *asmptr = 0x00;
1122                 }
1123
1124                 msg->msg_flags |= MSG_OOB;
1125         } else {
1126                 /* Now we can treat all alike */
1127                 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1128                                         flags & MSG_DONTWAIT, &rc);
1129                 if (!skb)
1130                         goto out;
1131
1132                 qbit = (skb->data[0] & X25_Q_BIT) == X25_Q_BIT;
1133
1134                 skb_pull(skb, x25->neighbour->extended ?
1135                                 X25_EXT_MIN_LEN : X25_STD_MIN_LEN);
1136
1137                 if (x25->qbitincl) {
1138                         asmptr  = skb_push(skb, 1);
1139                         *asmptr = qbit;
1140                 }
1141         }
1142
1143         skb->h.raw = skb->data;
1144
1145         copied = skb->len;
1146
1147         if (copied > size) {
1148                 copied = size;
1149                 msg->msg_flags |= MSG_TRUNC;
1150         }
1151
1152         /* Currently, each datagram always contains a complete record */ 
1153         msg->msg_flags |= MSG_EOR;
1154
1155         rc = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1156         if (rc)
1157                 goto out_free_dgram;
1158
1159         if (sx25) {
1160                 sx25->sx25_family = AF_X25;
1161                 sx25->sx25_addr   = x25->dest_addr;
1162         }
1163
1164         msg->msg_namelen = sizeof(struct sockaddr_x25);
1165
1166         lock_sock(sk);
1167         x25_check_rbuf(sk);
1168         release_sock(sk);
1169         rc = copied;
1170 out_free_dgram:
1171         skb_free_datagram(sk, skb);
1172 out:
1173         return rc;
1174 }
1175
1176
1177 static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1178 {
1179         struct sock *sk = sock->sk;
1180         struct x25_opt *x25 = x25_sk(sk);
1181         void __user *argp = (void __user *)arg;
1182         int rc;
1183
1184         switch (cmd) {
1185                 case TIOCOUTQ: {
1186                         int amount = sk->sk_sndbuf -
1187                                      atomic_read(&sk->sk_wmem_alloc);
1188                         if (amount < 0)
1189                                 amount = 0;
1190                         rc = put_user(amount, (unsigned int __user *)argp);
1191                         break;
1192                 }
1193
1194                 case TIOCINQ: {
1195                         struct sk_buff *skb;
1196                         int amount = 0;
1197                         /*
1198                          * These two are safe on a single CPU system as
1199                          * only user tasks fiddle here
1200                          */
1201                         if ((skb = skb_peek(&sk->sk_receive_queue)) != NULL)
1202                                 amount = skb->len;
1203                         rc = put_user(amount, (unsigned int __user *)argp);
1204                         break;
1205                 }
1206
1207                 case SIOCGSTAMP:
1208                         rc = -EINVAL;
1209                         if (sk)
1210                                 rc = sock_get_timestamp(sk, 
1211                                                 (struct timeval __user *)argp); 
1212                         break;
1213                 case SIOCGIFADDR:
1214                 case SIOCSIFADDR:
1215                 case SIOCGIFDSTADDR:
1216                 case SIOCSIFDSTADDR:
1217                 case SIOCGIFBRDADDR:
1218                 case SIOCSIFBRDADDR:
1219                 case SIOCGIFNETMASK:
1220                 case SIOCSIFNETMASK:
1221                 case SIOCGIFMETRIC:
1222                 case SIOCSIFMETRIC:
1223                         rc = -EINVAL;
1224                         break;
1225                 case SIOCADDRT:
1226                 case SIOCDELRT:
1227                         rc = -EPERM;
1228                         if (!capable(CAP_NET_ADMIN))
1229                                 break;
1230                         rc = x25_route_ioctl(cmd, argp);
1231                         break;
1232                 case SIOCX25GSUBSCRIP:
1233                         rc = x25_subscr_ioctl(cmd, argp);
1234                         break;
1235                 case SIOCX25SSUBSCRIP:
1236                         rc = -EPERM;
1237                         if (!capable(CAP_NET_ADMIN))
1238                                 break;
1239                         rc = x25_subscr_ioctl(cmd, argp);
1240                         break;
1241                 case SIOCX25GFACILITIES: {
1242                         struct x25_facilities fac = x25->facilities;
1243                         rc = copy_to_user(argp, &fac,
1244                                           sizeof(fac)) ? -EFAULT : 0;
1245                         break;
1246                 }
1247
1248                 case SIOCX25SFACILITIES: {
1249                         struct x25_facilities facilities;
1250                         rc = -EFAULT;
1251                         if (copy_from_user(&facilities, argp,
1252                                            sizeof(facilities)))
1253                                 break;
1254                         rc = -EINVAL;
1255                         if (sk->sk_state != TCP_LISTEN &&
1256                             sk->sk_state != TCP_CLOSE)
1257                                 break;
1258                         if (facilities.pacsize_in < X25_PS16 ||
1259                             facilities.pacsize_in > X25_PS4096)
1260                                 break;
1261                         if (facilities.pacsize_out < X25_PS16 ||
1262                             facilities.pacsize_out > X25_PS4096)
1263                                 break;
1264                         if (facilities.winsize_in < 1 ||
1265                             facilities.winsize_in > 127)
1266                                 break;
1267                         if (facilities.throughput < 0x03 ||
1268                             facilities.throughput > 0xDD)
1269                                 break;
1270                         if (facilities.reverse && facilities.reverse != 1)
1271                                 break;
1272                         x25->facilities = facilities;
1273                         rc = 0;
1274                         break;
1275                 }
1276
1277                 case SIOCX25GCALLUSERDATA: {
1278                         struct x25_calluserdata cud = x25->calluserdata;
1279                         rc = copy_to_user(argp, &cud,
1280                                           sizeof(cud)) ? -EFAULT : 0;
1281                         break;
1282                 }
1283
1284                 case SIOCX25SCALLUSERDATA: {
1285                         struct x25_calluserdata calluserdata;
1286
1287                         rc = -EFAULT;
1288                         if (copy_from_user(&calluserdata, argp,
1289                                            sizeof(calluserdata)))
1290                                 break;
1291                         rc = -EINVAL;
1292                         if (calluserdata.cudlength > X25_MAX_CUD_LEN)
1293                                 break;
1294                         x25->calluserdata = calluserdata;
1295                         rc = 0;
1296                         break;
1297                 }
1298
1299                 case SIOCX25GCAUSEDIAG: {
1300                         struct x25_causediag causediag;
1301                         causediag = x25->causediag;
1302                         rc = copy_to_user(argp, &causediag,
1303                                           sizeof(causediag)) ? -EFAULT : 0;
1304                         break;
1305                 }
1306
1307                 default:
1308                         rc = dev_ioctl(cmd, argp);
1309                         break;
1310         }
1311
1312         return rc;
1313 }
1314
1315 struct net_proto_family x25_family_ops = {
1316         .family =       AF_X25,
1317         .create =       x25_create,
1318         .owner  =       THIS_MODULE,
1319 };
1320
1321 static struct proto_ops SOCKOPS_WRAPPED(x25_proto_ops) = {
1322         .family =       AF_X25,
1323         .owner =        THIS_MODULE,
1324         .release =      x25_release,
1325         .bind =         x25_bind,
1326         .connect =      x25_connect,
1327         .socketpair =   sock_no_socketpair,
1328         .accept =       x25_accept,
1329         .getname =      x25_getname,
1330         .poll =         datagram_poll,
1331         .ioctl =        x25_ioctl,
1332         .listen =       x25_listen,
1333         .shutdown =     sock_no_shutdown,
1334         .setsockopt =   x25_setsockopt,
1335         .getsockopt =   x25_getsockopt,
1336         .sendmsg =      x25_sendmsg,
1337         .recvmsg =      x25_recvmsg,
1338         .mmap =         sock_no_mmap,
1339         .sendpage =     sock_no_sendpage,
1340 };
1341
1342 #include <linux/smp_lock.h>
1343 SOCKOPS_WRAP(x25_proto, AF_X25);
1344
1345 static struct packet_type x25_packet_type = {
1346         .type = __constant_htons(ETH_P_X25),
1347         .func = x25_lapb_receive_frame,
1348 };
1349
1350 struct notifier_block x25_dev_notifier = {
1351         .notifier_call = x25_device_event,
1352 };
1353
1354 void x25_kill_by_neigh(struct x25_neigh *nb)
1355 {
1356         struct sock *s;
1357         struct hlist_node *node;
1358
1359         write_lock_bh(&x25_list_lock);
1360
1361         sk_for_each(s, node, &x25_list)
1362                 if (x25_sk(s)->neighbour == nb)
1363                         x25_disconnect(s, ENETUNREACH, 0, 0);
1364
1365         write_unlock_bh(&x25_list_lock);
1366 }
1367
1368 static int __init x25_init(void)
1369 {
1370         sock_register(&x25_family_ops);
1371
1372         dev_add_pack(&x25_packet_type);
1373
1374         register_netdevice_notifier(&x25_dev_notifier);
1375
1376         printk(KERN_INFO "X.25 for Linux. Version 0.2 for Linux 2.1.15\n");
1377
1378 #ifdef CONFIG_SYSCTL
1379         x25_register_sysctl();
1380 #endif
1381         x25_proc_init();
1382         return 0;
1383 }
1384 module_init(x25_init);
1385
1386 static void __exit x25_exit(void)
1387 {
1388         x25_proc_exit();
1389         x25_link_free();
1390         x25_route_free();
1391
1392 #ifdef CONFIG_SYSCTL
1393         x25_unregister_sysctl();
1394 #endif
1395
1396         unregister_netdevice_notifier(&x25_dev_notifier);
1397
1398         dev_remove_pack(&x25_packet_type);
1399
1400         sock_unregister(AF_X25);
1401 }
1402 module_exit(x25_exit);
1403
1404 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
1405 MODULE_DESCRIPTION("The X.25 Packet Layer network layer protocol");
1406 MODULE_LICENSE("GPL");
1407 MODULE_ALIAS_NETPROTO(PF_X25);