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[PATCH] g_file_storage: fix obscure race condition
[linux/fpc-iii.git] / drivers / isdn / hisax / isdnl3.c
blobc9917cd2132b74e0fb311447aaa66c1b03cdd395
1 /* $Id: isdnl3.c,v 2.22.2.3 2004/01/13 14:31:25 keil Exp $
2 *
3 * Author Karsten Keil
4 * based on the teles driver from Jan den Ouden
5 * Copyright by Karsten Keil <keil@isdn4linux.de>
6 *
7 * This software may be used and distributed according to the terms
8 * of the GNU General Public License, incorporated herein by reference.
9 *
10 * For changes and modifications please read
11 * Documentation/isdn/HiSax.cert
12 *
13 * Thanks to Jan den Ouden
14 * Fritz Elfert
15 *
16 */
17
18 #include <linux/init.h>
19 #include "hisax.h"
20 #include "isdnl3.h"
21 #include <linux/config.h>
22
23 const char *l3_revision = "$Revision: 2.22.2.3 $";
24
25 static struct Fsm l3fsm;
26
27 enum {
28 ST_L3_LC_REL,
29 ST_L3_LC_ESTAB_WAIT,
30 ST_L3_LC_REL_DELAY,
31 ST_L3_LC_REL_WAIT,
32 ST_L3_LC_ESTAB,
33 };
34
35 #define L3_STATE_COUNT (ST_L3_LC_ESTAB+1)
36
37 static char *strL3State[] =
38 {
39 "ST_L3_LC_REL",
40 "ST_L3_LC_ESTAB_WAIT",
41 "ST_L3_LC_REL_DELAY",
42 "ST_L3_LC_REL_WAIT",
43 "ST_L3_LC_ESTAB",
44 };
45
46 enum {
47 EV_ESTABLISH_REQ,
48 EV_ESTABLISH_IND,
49 EV_ESTABLISH_CNF,
50 EV_RELEASE_REQ,
51 EV_RELEASE_CNF,
52 EV_RELEASE_IND,
53 EV_TIMEOUT,
54 };
55
56 #define L3_EVENT_COUNT (EV_TIMEOUT+1)
57
58 static char *strL3Event[] =
59 {
60 "EV_ESTABLISH_REQ",
61 "EV_ESTABLISH_IND",
62 "EV_ESTABLISH_CNF",
63 "EV_RELEASE_REQ",
64 "EV_RELEASE_CNF",
65 "EV_RELEASE_IND",
66 "EV_TIMEOUT",
67 };
68
69 static void
70 l3m_debug(struct FsmInst *fi, char *fmt, ...)
71 {
72 va_list args;
73 struct PStack *st = fi->userdata;
74
75 va_start(args, fmt);
76 VHiSax_putstatus(st->l1.hardware, st->l3.debug_id, fmt, args);
77 va_end(args);
78 }
79
80 u_char *
81 findie(u_char * p, int size, u_char ie, int wanted_set)
82 {
83 int l, codeset, maincodeset;
84 u_char *pend = p + size;
85
86 /* skip protocol discriminator, callref and message type */
87 p++;
88 l = (*p++) & 0xf;
89 p += l;
90 p++;
91 codeset = 0;
92 maincodeset = 0;
93 /* while there are bytes left... */
94 while (p < pend) {
95 if ((*p & 0xf0) == 0x90) {
96 codeset = *p & 0x07;
97 if (!(*p & 0x08))
98 maincodeset = codeset;
99 }
100 if (*p & 0x80)
101 p++;
102 else {
103 if (codeset == wanted_set) {
104 if (*p == ie)
105 { /* improved length check (Werner Cornelius) */
106 if ((pend - p) < 2)
107 return(NULL);
108 if (*(p+1) > (pend - (p+2)))
109 return(NULL);
110 return (p);
111 }
112
113 if (*p > ie)
114 return (NULL);
115 }
116 p++;
117 l = *p++;
118 p += l;
119 codeset = maincodeset;
120 }
121 }
122 return (NULL);
123 }
124
125 int
126 getcallref(u_char * p)
127 {
128 int l, cr = 0;
129
130 p++; /* prot discr */
131 if (*p & 0xfe) /* wrong callref BRI only 1 octet*/
132 return(-2);
133 l = 0xf & *p++; /* callref length */
134 if (!l) /* dummy CallRef */
135 return(-1);
136 cr = *p++;
137 return (cr);
138 }
139
140 static int OrigCallRef = 0;
141
142 int
143 newcallref(void)
144 {
145 if (OrigCallRef == 127)
146 OrigCallRef = 1;
147 else
148 OrigCallRef++;
149 return (OrigCallRef);
150 }
151
152 void
153 newl3state(struct l3_process *pc, int state)
154 {
155 if (pc->debug & L3_DEB_STATE)
156 l3_debug(pc->st, "newstate cr %d %d --> %d",
157 pc->callref & 0x7F,
158 pc->state, state);
159 pc->state = state;
160 }
161
162 static void
163 L3ExpireTimer(struct L3Timer *t)
164 {
165 t->pc->st->lli.l4l3(t->pc->st, t->event, t->pc);
166 }
167
168 void
169 L3InitTimer(struct l3_process *pc, struct L3Timer *t)
170 {
171 t->pc = pc;
172 t->tl.function = (void *) L3ExpireTimer;
173 t->tl.data = (long) t;
174 init_timer(&t->tl);
175 }
176
177 void
178 L3DelTimer(struct L3Timer *t)
179 {
180 del_timer(&t->tl);
181 }
182
183 int
184 L3AddTimer(struct L3Timer *t,
185 int millisec, int event)
186 {
187 if (timer_pending(&t->tl)) {
188 printk(KERN_WARNING "L3AddTimer: timer already active!\n");
189 return -1;
190 }
191 init_timer(&t->tl);
192 t->event = event;
193 t->tl.expires = jiffies + (millisec * HZ) / 1000;
194 add_timer(&t->tl);
195 return 0;
196 }
197
198 void
199 StopAllL3Timer(struct l3_process *pc)
200 {
201 L3DelTimer(&pc->timer);
202 }
203
204 struct sk_buff *
205 l3_alloc_skb(int len)
206 {
207 struct sk_buff *skb;
208
209 if (!(skb = alloc_skb(len + MAX_HEADER_LEN, GFP_ATOMIC))) {
210 printk(KERN_WARNING "HiSax: No skb for D-channel\n");
211 return (NULL);
212 }
213 skb_reserve(skb, MAX_HEADER_LEN);
214 return (skb);
215 }
216
217 static void
218 no_l3_proto(struct PStack *st, int pr, void *arg)
219 {
220 struct sk_buff *skb = arg;
221
222 HiSax_putstatus(st->l1.hardware, "L3", "no D protocol");
223 if (skb) {
224 dev_kfree_skb(skb);
225 }
226 }
227
228 static int
229 no_l3_proto_spec(struct PStack *st, isdn_ctrl *ic)
230 {
231 printk(KERN_WARNING "HiSax: no specific protocol handler for proto %lu\n",ic->arg & 0xFF);
232 return(-1);
233 }
234
235 #ifdef CONFIG_HISAX_EURO
236 extern void setstack_dss1(struct PStack *st);
237 #endif
238
239 #ifdef CONFIG_HISAX_NI1
240 extern void setstack_ni1(struct PStack *st);
241 #endif
242
243 #ifdef CONFIG_HISAX_1TR6
244 extern void setstack_1tr6(struct PStack *st);
245 #endif
246
247 struct l3_process
248 *getl3proc(struct PStack *st, int cr)
249 {
250 struct l3_process *p = st->l3.proc;
251
252 while (p)
253 if (p->callref == cr)
254 return (p);
255 else
256 p = p->next;
257 return (NULL);
258 }
259
260 struct l3_process
261 *new_l3_process(struct PStack *st, int cr)
262 {
263 struct l3_process *p, *np;
264
265 if (!(p = kmalloc(sizeof(struct l3_process), GFP_ATOMIC))) {
266 printk(KERN_ERR "HiSax can't get memory for cr %d\n", cr);
267 return (NULL);
268 }
269 if (!st->l3.proc)
270 st->l3.proc = p;
271 else {
272 np = st->l3.proc;
273 while (np->next)
274 np = np->next;
275 np->next = p;
276 }
277 p->next = NULL;
278 p->debug = st->l3.debug;
279 p->callref = cr;
280 p->state = 0;
281 p->chan = NULL;
282 p->st = st;
283 p->N303 = st->l3.N303;
284 L3InitTimer(p, &p->timer);
285 return (p);
286 };
287
288 void
289 release_l3_process(struct l3_process *p)
290 {
291 struct l3_process *np, *pp = NULL;
292
293 if (!p)
294 return;
295 np = p->st->l3.proc;
296 while (np) {
297 if (np == p) {
298 StopAllL3Timer(p);
299 if (pp)
300 pp->next = np->next;
301 else if (!(p->st->l3.proc = np->next) &&
302 !test_bit(FLG_PTP, &p->st->l2.flag)) {
303 if (p->debug)
304 l3_debug(p->st, "release_l3_process: last process");
305 if (skb_queue_empty(&p->st->l3.squeue)) {
306 if (p->debug)
307 l3_debug(p->st, "release_l3_process: release link");
308 if (p->st->protocol != ISDN_PTYPE_NI1)
309 FsmEvent(&p->st->l3.l3m, EV_RELEASE_REQ, NULL);
310 else
311 FsmEvent(&p->st->l3.l3m, EV_RELEASE_IND, NULL);
312 } else {
313 if (p->debug)
314 l3_debug(p->st, "release_l3_process: not release link");
315 }
316 }
317 kfree(p);
318 return;
319 }
320 pp = np;
321 np = np->next;
322 }
323 printk(KERN_ERR "HiSax internal L3 error CR(%d) not in list\n", p->callref);
324 l3_debug(p->st, "HiSax internal L3 error CR(%d) not in list", p->callref);
325 };
326
327 static void
328 l3ml3p(struct PStack *st, int pr)
329 {
330 struct l3_process *p = st->l3.proc;
331 struct l3_process *np;
332
333 while (p) {
334 /* p might be kfreed under us, so we need to save where we want to go on */
335 np = p->next;
336 st->l3.l3ml3(st, pr, p);
337 p = np;
338 }
339 }
340
341 void
342 setstack_l3dc(struct PStack *st, struct Channel *chanp)
343 {
344 char tmp[64];
345
346 st->l3.proc = NULL;
347 st->l3.global = NULL;
348 skb_queue_head_init(&st->l3.squeue);
349 st->l3.l3m.fsm = &l3fsm;
350 st->l3.l3m.state = ST_L3_LC_REL;
351 st->l3.l3m.debug = 1;
352 st->l3.l3m.userdata = st;
353 st->l3.l3m.userint = 0;
354 st->l3.l3m.printdebug = l3m_debug;
355 FsmInitTimer(&st->l3.l3m, &st->l3.l3m_timer);
356 strcpy(st->l3.debug_id, "L3DC ");
357 st->lli.l4l3_proto = no_l3_proto_spec;
358
359 #ifdef CONFIG_HISAX_EURO
360 if (st->protocol == ISDN_PTYPE_EURO) {
361 setstack_dss1(st);
362 } else
363 #endif
364 #ifdef CONFIG_HISAX_NI1
365 if (st->protocol == ISDN_PTYPE_NI1) {
366 setstack_ni1(st);
367 } else
368 #endif
369 #ifdef CONFIG_HISAX_1TR6
370 if (st->protocol == ISDN_PTYPE_1TR6) {
371 setstack_1tr6(st);
372 } else
373 #endif
374 if (st->protocol == ISDN_PTYPE_LEASED) {
375 st->lli.l4l3 = no_l3_proto;
376 st->l2.l2l3 = no_l3_proto;
377 st->l3.l3ml3 = no_l3_proto;
378 printk(KERN_INFO "HiSax: Leased line mode\n");
379 } else {
380 st->lli.l4l3 = no_l3_proto;
381 st->l2.l2l3 = no_l3_proto;
382 st->l3.l3ml3 = no_l3_proto;
383 sprintf(tmp, "protocol %s not supported",
384 (st->protocol == ISDN_PTYPE_1TR6) ? "1tr6" :
385 (st->protocol == ISDN_PTYPE_EURO) ? "euro" :
386 (st->protocol == ISDN_PTYPE_NI1) ? "ni1" :
387 "unknown");
388 printk(KERN_WARNING "HiSax: %s\n", tmp);
389 st->protocol = -1;
390 }
391 }
392
393 static void
394 isdnl3_trans(struct PStack *st, int pr, void *arg) {
395 st->l3.l3l2(st, pr, arg);
396 }
397
398 void
399 releasestack_isdnl3(struct PStack *st)
400 {
401 while (st->l3.proc)
402 release_l3_process(st->l3.proc);
403 if (st->l3.global) {
404 StopAllL3Timer(st->l3.global);
405 kfree(st->l3.global);
406 st->l3.global = NULL;
407 }
408 FsmDelTimer(&st->l3.l3m_timer, 54);
409 skb_queue_purge(&st->l3.squeue);
410 }
411
412 void
413 setstack_l3bc(struct PStack *st, struct Channel *chanp)
414 {
415
416 st->l3.proc = NULL;
417 st->l3.global = NULL;
418 skb_queue_head_init(&st->l3.squeue);
419 st->l3.l3m.fsm = &l3fsm;
420 st->l3.l3m.state = ST_L3_LC_REL;
421 st->l3.l3m.debug = 1;
422 st->l3.l3m.userdata = st;
423 st->l3.l3m.userint = 0;
424 st->l3.l3m.printdebug = l3m_debug;
425 strcpy(st->l3.debug_id, "L3BC ");
426 st->lli.l4l3 = isdnl3_trans;
427 }
428
429 #define DREL_TIMER_VALUE 40000
430
431 static void
432 lc_activate(struct FsmInst *fi, int event, void *arg)
433 {
434 struct PStack *st = fi->userdata;
435
436 FsmChangeState(fi, ST_L3_LC_ESTAB_WAIT);
437 st->l3.l3l2(st, DL_ESTABLISH | REQUEST, NULL);
438 }
439
440 static void
441 lc_connect(struct FsmInst *fi, int event, void *arg)
442 {
443 struct PStack *st = fi->userdata;
444 struct sk_buff *skb = arg;
445 int dequeued = 0;
446
447 FsmChangeState(fi, ST_L3_LC_ESTAB);
448 while ((skb = skb_dequeue(&st->l3.squeue))) {
449 st->l3.l3l2(st, DL_DATA | REQUEST, skb);
450 dequeued++;
451 }
452 if ((!st->l3.proc) && dequeued) {
453 if (st->l3.debug)
454 l3_debug(st, "lc_connect: release link");
455 FsmEvent(&st->l3.l3m, EV_RELEASE_REQ, NULL);
456 } else
457 l3ml3p(st, DL_ESTABLISH | INDICATION);
458 }
459
460 static void
461 lc_connected(struct FsmInst *fi, int event, void *arg)
462 {
463 struct PStack *st = fi->userdata;
464 struct sk_buff *skb = arg;
465 int dequeued = 0;
466
467 FsmDelTimer(&st->l3.l3m_timer, 51);
468 FsmChangeState(fi, ST_L3_LC_ESTAB);
469 while ((skb = skb_dequeue(&st->l3.squeue))) {
470 st->l3.l3l2(st, DL_DATA | REQUEST, skb);
471 dequeued++;
472 }
473 if ((!st->l3.proc) && dequeued) {
474 if (st->l3.debug)
475 l3_debug(st, "lc_connected: release link");
476 FsmEvent(&st->l3.l3m, EV_RELEASE_REQ, NULL);
477 } else
478 l3ml3p(st, DL_ESTABLISH | CONFIRM);
479 }
480
481 static void
482 lc_start_delay(struct FsmInst *fi, int event, void *arg)
483 {
484 struct PStack *st = fi->userdata;
485
486 FsmChangeState(fi, ST_L3_LC_REL_DELAY);
487 FsmAddTimer(&st->l3.l3m_timer, DREL_TIMER_VALUE, EV_TIMEOUT, NULL, 50);
488 }
489
490 static void
491 lc_start_delay_check(struct FsmInst *fi, int event, void *arg)
492 /* 20/09/00 - GE timer not user for NI-1 as layer 2 should stay up */
493 {
494 struct PStack *st = fi->userdata;
495
496 FsmChangeState(fi, ST_L3_LC_REL_DELAY);
497 /* 19/09/00 - GE timer not user for NI-1 */
498 if (st->protocol != ISDN_PTYPE_NI1)
499 FsmAddTimer(&st->l3.l3m_timer, DREL_TIMER_VALUE, EV_TIMEOUT, NULL, 50);
500 }
501
502 static void
503 lc_release_req(struct FsmInst *fi, int event, void *arg)
504 {
505 struct PStack *st = fi->userdata;
506
507 if (test_bit(FLG_L2BLOCK, &st->l2.flag)) {
508 if (st->l3.debug)
509 l3_debug(st, "lc_release_req: l2 blocked");
510 /* restart release timer */
511 FsmAddTimer(&st->l3.l3m_timer, DREL_TIMER_VALUE, EV_TIMEOUT, NULL, 51);
512 } else {
513 FsmChangeState(fi, ST_L3_LC_REL_WAIT);
514 st->l3.l3l2(st, DL_RELEASE | REQUEST, NULL);
515 }
516 }
517
518 static void
519 lc_release_ind(struct FsmInst *fi, int event, void *arg)
520 {
521 struct PStack *st = fi->userdata;
522
523 FsmDelTimer(&st->l3.l3m_timer, 52);
524 FsmChangeState(fi, ST_L3_LC_REL);
525 skb_queue_purge(&st->l3.squeue);
526 l3ml3p(st, DL_RELEASE | INDICATION);
527 }
528
529 static void
530 lc_release_cnf(struct FsmInst *fi, int event, void *arg)
531 {
532 struct PStack *st = fi->userdata;
533
534 FsmChangeState(fi, ST_L3_LC_REL);
535 skb_queue_purge(&st->l3.squeue);
536 l3ml3p(st, DL_RELEASE | CONFIRM);
537 }
538
539
540 /* *INDENT-OFF* */
541 static struct FsmNode L3FnList[] __initdata =
542 {
543 {ST_L3_LC_REL, EV_ESTABLISH_REQ, lc_activate},
544 {ST_L3_LC_REL, EV_ESTABLISH_IND, lc_connect},
545 {ST_L3_LC_REL, EV_ESTABLISH_CNF, lc_connect},
546 {ST_L3_LC_ESTAB_WAIT, EV_ESTABLISH_CNF, lc_connected},
547 {ST_L3_LC_ESTAB_WAIT, EV_RELEASE_REQ, lc_start_delay},
548 {ST_L3_LC_ESTAB_WAIT, EV_RELEASE_IND, lc_release_ind},
549 {ST_L3_LC_ESTAB, EV_RELEASE_IND, lc_release_ind},
550 {ST_L3_LC_ESTAB, EV_RELEASE_REQ, lc_start_delay_check},
551 {ST_L3_LC_REL_DELAY, EV_RELEASE_IND, lc_release_ind},
552 {ST_L3_LC_REL_DELAY, EV_ESTABLISH_REQ, lc_connected},
553 {ST_L3_LC_REL_DELAY, EV_TIMEOUT, lc_release_req},
554 {ST_L3_LC_REL_WAIT, EV_RELEASE_CNF, lc_release_cnf},
555 {ST_L3_LC_REL_WAIT, EV_ESTABLISH_REQ, lc_activate},
556 };
557 /* *INDENT-ON* */
558
559 #define L3_FN_COUNT (sizeof(L3FnList)/sizeof(struct FsmNode))
560
561 void
562 l3_msg(struct PStack *st, int pr, void *arg)
563 {
564 switch (pr) {
565 case (DL_DATA | REQUEST):
566 if (st->l3.l3m.state == ST_L3_LC_ESTAB) {
567 st->l3.l3l2(st, pr, arg);
568 } else {
569 struct sk_buff *skb = arg;
570
571 skb_queue_tail(&st->l3.squeue, skb);
572 FsmEvent(&st->l3.l3m, EV_ESTABLISH_REQ, NULL);
573 }
574 break;
575 case (DL_ESTABLISH | REQUEST):
576 FsmEvent(&st->l3.l3m, EV_ESTABLISH_REQ, NULL);
577 break;
578 case (DL_ESTABLISH | CONFIRM):
579 FsmEvent(&st->l3.l3m, EV_ESTABLISH_CNF, NULL);
580 break;
581 case (DL_ESTABLISH | INDICATION):
582 FsmEvent(&st->l3.l3m, EV_ESTABLISH_IND, NULL);
583 break;
584 case (DL_RELEASE | INDICATION):
585 FsmEvent(&st->l3.l3m, EV_RELEASE_IND, NULL);
586 break;
587 case (DL_RELEASE | CONFIRM):
588 FsmEvent(&st->l3.l3m, EV_RELEASE_CNF, NULL);
589 break;
590 case (DL_RELEASE | REQUEST):
591 FsmEvent(&st->l3.l3m, EV_RELEASE_REQ, NULL);
592 break;
593 }
594 }
595
596 int __init
597 Isdnl3New(void)
598 {
599 l3fsm.state_count = L3_STATE_COUNT;
600 l3fsm.event_count = L3_EVENT_COUNT;
601 l3fsm.strEvent = strL3Event;
602 l3fsm.strState = strL3State;
603 return FsmNew(&l3fsm, L3FnList, L3_FN_COUNT);
604 }
605
606 void
607 Isdnl3Free(void)
608 {
609 FsmFree(&l3fsm);
610 }
Linux with added FPC-III support