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 <linux/slab.h>
20 #include "hisax.h"
21 #include "isdnl3.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 __attribute__((format(printf, 2, 3))) void
l3m_debug(struct FsmInst * fi,char * fmt,...)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 *
findie(u_char * p,int size,u_char ie,int wanted_set)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
getcallref(u_char * p)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
newcallref(void)143 newcallref(void)
144 {
145 	if (OrigCallRef == 127)
146 		OrigCallRef = 1;
147 	else
148 		OrigCallRef++;
149 	return (OrigCallRef);
150 }
151 
152 void
newl3state(struct l3_process * pc,int state)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
L3ExpireTimer(struct L3Timer * t)163 L3ExpireTimer(struct L3Timer *t)
164 {
165 	t->pc->st->lli.l4l3(t->pc->st, t->event, t->pc);
166 }
167 
168 void
L3InitTimer(struct l3_process * pc,struct L3Timer * t)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
L3DelTimer(struct L3Timer * t)178 L3DelTimer(struct L3Timer *t)
179 {
180 	del_timer(&t->tl);
181 }
182 
183 int
L3AddTimer(struct L3Timer * t,int millisec,int event)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
StopAllL3Timer(struct l3_process * pc)199 StopAllL3Timer(struct l3_process *pc)
200 {
201 	L3DelTimer(&pc->timer);
202 }
203 
204 struct sk_buff *
l3_alloc_skb(int len)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
no_l3_proto(struct PStack * st,int pr,void * arg)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
no_l3_proto_spec(struct PStack * st,isdn_ctrl * ic)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 struct l3_process
getl3proc(struct PStack * st,int cr)236 *getl3proc(struct PStack *st, int cr)
237 {
238 	struct l3_process *p = st->l3.proc;
239 
240 	while (p)
241 		if (p->callref == cr)
242 			return (p);
243 		else
244 			p = p->next;
245 	return (NULL);
246 }
247 
248 struct l3_process
new_l3_process(struct PStack * st,int cr)249 *new_l3_process(struct PStack *st, int cr)
250 {
251 	struct l3_process *p, *np;
252 
253 	if (!(p = kmalloc(sizeof(struct l3_process), GFP_ATOMIC))) {
254 		printk(KERN_ERR "HiSax can't get memory for cr %d\n", cr);
255 		return (NULL);
256 	}
257 	if (!st->l3.proc)
258 		st->l3.proc = p;
259 	else {
260 		np = st->l3.proc;
261 		while (np->next)
262 			np = np->next;
263 		np->next = p;
264 	}
265 	p->next = NULL;
266 	p->debug = st->l3.debug;
267 	p->callref = cr;
268 	p->state = 0;
269 	p->chan = NULL;
270 	p->st = st;
271 	p->N303 = st->l3.N303;
272 	L3InitTimer(p, &p->timer);
273 	return (p);
274 };
275 
276 void
release_l3_process(struct l3_process * p)277 release_l3_process(struct l3_process *p)
278 {
279 	struct l3_process *np, *pp = NULL;
280 
281 	if (!p)
282 		return;
283 	np = p->st->l3.proc;
284 	while (np) {
285 		if (np == p) {
286 			StopAllL3Timer(p);
287 			if (pp)
288 				pp->next = np->next;
289 			else if (!(p->st->l3.proc = np->next) &&
290 				!test_bit(FLG_PTP, &p->st->l2.flag)) {
291 				if (p->debug)
292 					l3_debug(p->st, "release_l3_process: last process");
293 				if (skb_queue_empty(&p->st->l3.squeue)) {
294 					if (p->debug)
295 						l3_debug(p->st, "release_l3_process: release link");
296 					if (p->st->protocol != ISDN_PTYPE_NI1)
297 						FsmEvent(&p->st->l3.l3m, EV_RELEASE_REQ, NULL);
298 					else
299 						FsmEvent(&p->st->l3.l3m, EV_RELEASE_IND, NULL);
300 				} else {
301 					if (p->debug)
302 						l3_debug(p->st, "release_l3_process: not release link");
303 				}
304 			}
305 			kfree(p);
306 			return;
307 		}
308 		pp = np;
309 		np = np->next;
310 	}
311 	printk(KERN_ERR "HiSax internal L3 error CR(%d) not in list\n", p->callref);
312 	l3_debug(p->st, "HiSax internal L3 error CR(%d) not in list", p->callref);
313 };
314 
315 static void
l3ml3p(struct PStack * st,int pr)316 l3ml3p(struct PStack *st, int pr)
317 {
318 	struct l3_process *p = st->l3.proc;
319 	struct l3_process *np;
320 
321 	while (p) {
322 		/* p might be kfreed under us, so we need to save where we want to go on */
323 		np = p->next;
324 		st->l3.l3ml3(st, pr, p);
325 		p = np;
326 	}
327 }
328 
329 void
setstack_l3dc(struct PStack * st,struct Channel * chanp)330 setstack_l3dc(struct PStack *st, struct Channel *chanp)
331 {
332 	char tmp[64];
333 
334 	st->l3.proc   = NULL;
335 	st->l3.global = NULL;
336 	skb_queue_head_init(&st->l3.squeue);
337 	st->l3.l3m.fsm = &l3fsm;
338 	st->l3.l3m.state = ST_L3_LC_REL;
339 	st->l3.l3m.debug = 1;
340 	st->l3.l3m.userdata = st;
341 	st->l3.l3m.userint = 0;
342 	st->l3.l3m.printdebug = l3m_debug;
343         FsmInitTimer(&st->l3.l3m, &st->l3.l3m_timer);
344 	strcpy(st->l3.debug_id, "L3DC ");
345 	st->lli.l4l3_proto = no_l3_proto_spec;
346 
347 #ifdef	CONFIG_HISAX_EURO
348 	if (st->protocol == ISDN_PTYPE_EURO) {
349 		setstack_dss1(st);
350 	} else
351 #endif
352 #ifdef  CONFIG_HISAX_NI1
353 	if (st->protocol == ISDN_PTYPE_NI1) {
354 		setstack_ni1(st);
355 	} else
356 #endif
357 #ifdef	CONFIG_HISAX_1TR6
358 	if (st->protocol == ISDN_PTYPE_1TR6) {
359 		setstack_1tr6(st);
360 	} else
361 #endif
362 	if (st->protocol == ISDN_PTYPE_LEASED) {
363 		st->lli.l4l3 = no_l3_proto;
364 		st->l2.l2l3 = no_l3_proto;
365                 st->l3.l3ml3 = no_l3_proto;
366 		printk(KERN_INFO "HiSax: Leased line mode\n");
367 	} else {
368 		st->lli.l4l3 = no_l3_proto;
369 		st->l2.l2l3 = no_l3_proto;
370                 st->l3.l3ml3 = no_l3_proto;
371 		sprintf(tmp, "protocol %s not supported",
372 			(st->protocol == ISDN_PTYPE_1TR6) ? "1tr6" :
373 			(st->protocol == ISDN_PTYPE_EURO) ? "euro" :
374 			(st->protocol == ISDN_PTYPE_NI1) ? "ni1" :
375 			"unknown");
376 		printk(KERN_WARNING "HiSax: %s\n", tmp);
377 		st->protocol = -1;
378 	}
379 }
380 
381 static void
isdnl3_trans(struct PStack * st,int pr,void * arg)382 isdnl3_trans(struct PStack *st, int pr, void *arg) {
383 	st->l3.l3l2(st, pr, arg);
384 }
385 
386 void
releasestack_isdnl3(struct PStack * st)387 releasestack_isdnl3(struct PStack *st)
388 {
389 	while (st->l3.proc)
390 		release_l3_process(st->l3.proc);
391 	if (st->l3.global) {
392 		StopAllL3Timer(st->l3.global);
393 		kfree(st->l3.global);
394 		st->l3.global = NULL;
395 	}
396 	FsmDelTimer(&st->l3.l3m_timer, 54);
397 	skb_queue_purge(&st->l3.squeue);
398 }
399 
400 void
setstack_l3bc(struct PStack * st,struct Channel * chanp)401 setstack_l3bc(struct PStack *st, struct Channel *chanp)
402 {
403 
404 	st->l3.proc   = NULL;
405 	st->l3.global = NULL;
406 	skb_queue_head_init(&st->l3.squeue);
407 	st->l3.l3m.fsm = &l3fsm;
408 	st->l3.l3m.state = ST_L3_LC_REL;
409 	st->l3.l3m.debug = 1;
410 	st->l3.l3m.userdata = st;
411 	st->l3.l3m.userint = 0;
412 	st->l3.l3m.printdebug = l3m_debug;
413 	strcpy(st->l3.debug_id, "L3BC ");
414 	st->lli.l4l3 = isdnl3_trans;
415 }
416 
417 #define DREL_TIMER_VALUE 40000
418 
419 static void
lc_activate(struct FsmInst * fi,int event,void * arg)420 lc_activate(struct FsmInst *fi, int event, void *arg)
421 {
422 	struct PStack *st = fi->userdata;
423 
424 	FsmChangeState(fi, ST_L3_LC_ESTAB_WAIT);
425 	st->l3.l3l2(st, DL_ESTABLISH | REQUEST, NULL);
426 }
427 
428 static void
lc_connect(struct FsmInst * fi,int event,void * arg)429 lc_connect(struct FsmInst *fi, int event, void *arg)
430 {
431 	struct PStack *st = fi->userdata;
432 	struct sk_buff *skb = arg;
433 	int dequeued = 0;
434 
435 	FsmChangeState(fi, ST_L3_LC_ESTAB);
436 	while ((skb = skb_dequeue(&st->l3.squeue))) {
437 		st->l3.l3l2(st, DL_DATA | REQUEST, skb);
438 		dequeued++;
439 	}
440 	if ((!st->l3.proc) &&  dequeued) {
441 		if (st->l3.debug)
442 			l3_debug(st, "lc_connect: release link");
443 		FsmEvent(&st->l3.l3m, EV_RELEASE_REQ, NULL);
444 	} else
445 		l3ml3p(st, DL_ESTABLISH | INDICATION);
446 }
447 
448 static void
lc_connected(struct FsmInst * fi,int event,void * arg)449 lc_connected(struct FsmInst *fi, int event, void *arg)
450 {
451 	struct PStack *st = fi->userdata;
452 	struct sk_buff *skb = arg;
453 	int dequeued = 0;
454 
455 	FsmDelTimer(&st->l3.l3m_timer, 51);
456 	FsmChangeState(fi, ST_L3_LC_ESTAB);
457 	while ((skb = skb_dequeue(&st->l3.squeue))) {
458 		st->l3.l3l2(st, DL_DATA | REQUEST, skb);
459 		dequeued++;
460 	}
461 	if ((!st->l3.proc) &&  dequeued) {
462 		if (st->l3.debug)
463 			l3_debug(st, "lc_connected: release link");
464 		FsmEvent(&st->l3.l3m, EV_RELEASE_REQ, NULL);
465 	} else
466 		l3ml3p(st, DL_ESTABLISH | CONFIRM);
467 }
468 
469 static void
lc_start_delay(struct FsmInst * fi,int event,void * arg)470 lc_start_delay(struct FsmInst *fi, int event, void *arg)
471 {
472        struct PStack *st = fi->userdata;
473 
474        FsmChangeState(fi, ST_L3_LC_REL_DELAY);
475        FsmAddTimer(&st->l3.l3m_timer, DREL_TIMER_VALUE, EV_TIMEOUT, NULL, 50);
476 }
477 
478 static void
lc_start_delay_check(struct FsmInst * fi,int event,void * arg)479 lc_start_delay_check(struct FsmInst *fi, int event, void *arg)
480 /* 20/09/00 - GE timer not user for NI-1 as layer 2 should stay up */
481 {
482        struct PStack *st = fi->userdata;
483 
484        FsmChangeState(fi, ST_L3_LC_REL_DELAY);
485        /* 19/09/00 - GE timer not user for NI-1 */
486        if (st->protocol != ISDN_PTYPE_NI1)
487        		FsmAddTimer(&st->l3.l3m_timer, DREL_TIMER_VALUE, EV_TIMEOUT, NULL, 50);
488 }
489 
490 static void
lc_release_req(struct FsmInst * fi,int event,void * arg)491 lc_release_req(struct FsmInst *fi, int event, void *arg)
492 {
493 	struct PStack *st = fi->userdata;
494 
495 	if (test_bit(FLG_L2BLOCK, &st->l2.flag)) {
496 		if (st->l3.debug)
497 			l3_debug(st, "lc_release_req: l2 blocked");
498 		/* restart release timer */
499 		FsmAddTimer(&st->l3.l3m_timer, DREL_TIMER_VALUE, EV_TIMEOUT, NULL, 51);
500 	} else {
501 		FsmChangeState(fi, ST_L3_LC_REL_WAIT);
502 		st->l3.l3l2(st, DL_RELEASE | REQUEST, NULL);
503 	}
504 }
505 
506 static void
lc_release_ind(struct FsmInst * fi,int event,void * arg)507 lc_release_ind(struct FsmInst *fi, int event, void *arg)
508 {
509 	struct PStack *st = fi->userdata;
510 
511 	FsmDelTimer(&st->l3.l3m_timer, 52);
512 	FsmChangeState(fi, ST_L3_LC_REL);
513 	skb_queue_purge(&st->l3.squeue);
514 	l3ml3p(st, DL_RELEASE | INDICATION);
515 }
516 
517 static void
lc_release_cnf(struct FsmInst * fi,int event,void * arg)518 lc_release_cnf(struct FsmInst *fi, int event, void *arg)
519 {
520 	struct PStack *st = fi->userdata;
521 
522 	FsmChangeState(fi, ST_L3_LC_REL);
523 	skb_queue_purge(&st->l3.squeue);
524 	l3ml3p(st, DL_RELEASE | CONFIRM);
525 }
526 
527 
528 /* *INDENT-OFF* */
529 static struct FsmNode L3FnList[] __initdata =
530 {
531 	{ST_L3_LC_REL,		EV_ESTABLISH_REQ,	lc_activate},
532 	{ST_L3_LC_REL,		EV_ESTABLISH_IND,	lc_connect},
533 	{ST_L3_LC_REL,		EV_ESTABLISH_CNF,	lc_connect},
534 	{ST_L3_LC_ESTAB_WAIT,	EV_ESTABLISH_CNF,	lc_connected},
535 	{ST_L3_LC_ESTAB_WAIT,	EV_RELEASE_REQ,		lc_start_delay},
536 	{ST_L3_LC_ESTAB_WAIT,	EV_RELEASE_IND,		lc_release_ind},
537 	{ST_L3_LC_ESTAB,	EV_RELEASE_IND,		lc_release_ind},
538 	{ST_L3_LC_ESTAB,	EV_RELEASE_REQ,		lc_start_delay_check},
539         {ST_L3_LC_REL_DELAY,    EV_RELEASE_IND,         lc_release_ind},
540         {ST_L3_LC_REL_DELAY,    EV_ESTABLISH_REQ,       lc_connected},
541         {ST_L3_LC_REL_DELAY,    EV_TIMEOUT,             lc_release_req},
542 	{ST_L3_LC_REL_WAIT,	EV_RELEASE_CNF,		lc_release_cnf},
543 	{ST_L3_LC_REL_WAIT,	EV_ESTABLISH_REQ,	lc_activate},
544 };
545 /* *INDENT-ON* */
546 
547 void
l3_msg(struct PStack * st,int pr,void * arg)548 l3_msg(struct PStack *st, int pr, void *arg)
549 {
550 	switch (pr) {
551 		case (DL_DATA | REQUEST):
552 			if (st->l3.l3m.state == ST_L3_LC_ESTAB) {
553 				st->l3.l3l2(st, pr, arg);
554 			} else {
555 				struct sk_buff *skb = arg;
556 
557 				skb_queue_tail(&st->l3.squeue, skb);
558 				FsmEvent(&st->l3.l3m, EV_ESTABLISH_REQ, NULL);
559 			}
560 			break;
561 		case (DL_ESTABLISH | REQUEST):
562 			FsmEvent(&st->l3.l3m, EV_ESTABLISH_REQ, NULL);
563 			break;
564 		case (DL_ESTABLISH | CONFIRM):
565 			FsmEvent(&st->l3.l3m, EV_ESTABLISH_CNF, NULL);
566 			break;
567 		case (DL_ESTABLISH | INDICATION):
568 			FsmEvent(&st->l3.l3m, EV_ESTABLISH_IND, NULL);
569 			break;
570 		case (DL_RELEASE | INDICATION):
571 			FsmEvent(&st->l3.l3m, EV_RELEASE_IND, NULL);
572 			break;
573 		case (DL_RELEASE | CONFIRM):
574 			FsmEvent(&st->l3.l3m, EV_RELEASE_CNF, NULL);
575 			break;
576 		case (DL_RELEASE | REQUEST):
577 			FsmEvent(&st->l3.l3m, EV_RELEASE_REQ, NULL);
578 			break;
579 	}
580 }
581 
582 int __init
Isdnl3New(void)583 Isdnl3New(void)
584 {
585 	l3fsm.state_count = L3_STATE_COUNT;
586 	l3fsm.event_count = L3_EVENT_COUNT;
587 	l3fsm.strEvent = strL3Event;
588 	l3fsm.strState = strL3State;
589 	return FsmNew(&l3fsm, L3FnList, ARRAY_SIZE(L3FnList));
590 }
591 
592 void
Isdnl3Free(void)593 Isdnl3Free(void)
594 {
595 	FsmFree(&l3fsm);
596 }
597