1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
|
/*
* CAPI encoder/decoder for
* Portugal Telecom CAPI 2.0
*
* Copyright (C) 1996 Universidade de Lisboa
*
* Written by Pedro Roque Marques (roque@di.fc.ul.pt)
*
* This software may be used and distributed according to the terms of
* the GNU General Public License, incorporated herein by reference.
*
* Not compatible with the AVM Gmbh. CAPI 2.0
*
*/
/*
* Documentation:
* - "Common ISDN API - Perfil Português - Versão 2.1",
* Telecom Portugal, Fev 1992.
* - "Common ISDN API - Especificação de protocolos para
* acesso aos canais B", Inesc, Jan 1994.
*/
/*
* TODO: better decoding of Information Elements
* for debug purposes mainly
* encode our number in CallerPN and ConnectedPN
*/
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/skbuff.h>
#include <asm/io.h>
#include <asm/string.h>
#include <linux/isdnif.h>
#include "pcbit.h"
#include "edss1.h"
#include "capi.h"
/*
* Encoding of CAPI messages
*
*/
int capi_conn_req(const char * calledPN, struct sk_buff **skb, int proto)
{
ushort len;
/*
* length
* AppInfoMask - 2
* BC0 - 3
* BC1 - 1
* Chan - 2
* Keypad - 1
* CPN - 1
* CPSA - 1
* CalledPN - 2 + strlen
* CalledPSA - 1
* rest... - 4
* ----------------
* Total 18 + strlen
*/
len = 18 + strlen(calledPN);
if (proto == ISDN_PROTO_L2_TRANS)
len++;
if ((*skb = dev_alloc_skb(len)) == NULL) {
printk(KERN_WARNING "capi_conn_req: alloc_skb failed\n");
return -1;
}
/* InfoElmMask */
*((ushort*) skb_put(*skb, 2)) = AppInfoMask;
if (proto == ISDN_PROTO_L2_TRANS)
{
/* Bearer Capability - Mandatory*/
*(skb_put(*skb, 1)) = 3; /* BC0.Length */
*(skb_put(*skb, 1)) = 0x80; /* Speech */
*(skb_put(*skb, 1)) = 0x10; /* Circuit Mode */
*(skb_put(*skb, 1)) = 0x23; /* A-law */
}
else
{
/* Bearer Capability - Mandatory*/
*(skb_put(*skb, 1)) = 2; /* BC0.Length */
*(skb_put(*skb, 1)) = 0x88; /* Digital Information */
*(skb_put(*skb, 1)) = 0x90; /* BC0.Octect4 */
}
/* Bearer Capability - Optional*/
*(skb_put(*skb, 1)) = 0; /* BC1.Length = 0 */
*(skb_put(*skb, 1)) = 1; /* ChannelID.Length = 1 */
*(skb_put(*skb, 1)) = 0x83; /* Basic Interface - Any Channel */
*(skb_put(*skb, 1)) = 0; /* Keypad.Length = 0 */
*(skb_put(*skb, 1)) = 0; /* CallingPN.Length = 0 */
*(skb_put(*skb, 1)) = 0; /* CallingPSA.Length = 0 */
/* Called Party Number */
*(skb_put(*skb, 1)) = strlen(calledPN) + 1;
*(skb_put(*skb, 1)) = 0x81;
memcpy(skb_put(*skb, strlen(calledPN)), calledPN, strlen(calledPN));
/* '#' */
*(skb_put(*skb, 1)) = 0; /* CalledPSA.Length = 0 */
/* LLC.Length = 0; */
/* HLC0.Length = 0; */
/* HLC1.Length = 0; */
/* UTUS.Length = 0; */
memset(skb_put(*skb, 4), 0, 4);
return len;
}
int capi_conn_resp(struct pcbit_chan* chan, struct sk_buff **skb)
{
if ((*skb = dev_alloc_skb(5)) == NULL) {
printk(KERN_WARNING "capi_conn_resp: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
*(skb_put(*skb, 1)) = 0x01; /* ACCEPT_CALL */
*(skb_put(*skb, 1)) = 0;
*(skb_put(*skb, 1)) = 0;
return 5;
}
int capi_conn_active_req(struct pcbit_chan* chan, struct sk_buff **skb)
{
/*
* 8 bytes
*/
if ((*skb = dev_alloc_skb(8)) == NULL) {
printk(KERN_WARNING "capi_conn_active_req: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
#ifdef DEBUG
printk(KERN_DEBUG "Call Reference: %04x\n", chan->callref);
#endif
*(skb_put(*skb, 1)) = 0; /* BC.Length = 0; */
*(skb_put(*skb, 1)) = 0; /* ConnectedPN.Length = 0 */
*(skb_put(*skb, 1)) = 0; /* PSA.Length */
*(skb_put(*skb, 1)) = 0; /* LLC.Length = 0; */
*(skb_put(*skb, 1)) = 0; /* HLC.Length = 0; */
*(skb_put(*skb, 1)) = 0; /* UTUS.Length = 0; */
return 8;
}
int capi_conn_active_resp(struct pcbit_chan* chan, struct sk_buff **skb)
{
/*
* 2 bytes
*/
if ((*skb = dev_alloc_skb(2)) == NULL) {
printk(KERN_WARNING "capi_conn_active_resp: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
return 2;
}
int capi_select_proto_req(struct pcbit_chan *chan, struct sk_buff **skb,
int outgoing)
{
/*
* 18 bytes
*/
if ((*skb = dev_alloc_skb(18)) == NULL) {
printk(KERN_WARNING "capi_select_proto_req: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
/* Layer2 protocol */
switch (chan->proto) {
case ISDN_PROTO_L2_X75I:
*(skb_put(*skb, 1)) = 0x05; /* LAPB */
break;
case ISDN_PROTO_L2_HDLC:
*(skb_put(*skb, 1)) = 0x02;
break;
case ISDN_PROTO_L2_TRANS:
/*
* Voice (a-law)
*/
*(skb_put(*skb, 1)) = 0x06;
break;
default:
#ifdef DEBUG
printk(KERN_DEBUG "Transparent\n");
#endif
*(skb_put(*skb, 1)) = 0x03;
break;
}
*(skb_put(*skb, 1)) = (outgoing ? 0x02 : 0x42); /* Don't ask */
*(skb_put(*skb, 1)) = 0x00;
*((ushort *) skb_put(*skb, 2)) = MRU;
*(skb_put(*skb, 1)) = 0x08; /* Modulo */
*(skb_put(*skb, 1)) = 0x07; /* Max Window */
*(skb_put(*skb, 1)) = 0x01; /* No Layer3 Protocol */
/*
* 2 - layer3 MTU [10]
* - Modulo [12]
* - Window
* - layer1 proto [14]
* - bitrate
* - sub-channel [16]
* - layer1dataformat [17]
*/
memset(skb_put(*skb, 8), 0, 8);
return 18;
}
int capi_activate_transp_req(struct pcbit_chan *chan, struct sk_buff **skb)
{
if ((*skb = dev_alloc_skb(7)) == NULL) {
printk(KERN_WARNING "capi_activate_transp_req: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
*(skb_put(*skb, 1)) = chan->layer2link; /* Layer2 id */
*(skb_put(*skb, 1)) = 0x00; /* Transmit by default */
*((ushort *) skb_put(*skb, 2)) = MRU;
*(skb_put(*skb, 1)) = 0x01; /* Enables reception*/
return 7;
}
int capi_tdata_req(struct pcbit_chan* chan, struct sk_buff *skb)
{
ushort data_len;
/*
* callref - 2
* layer2link - 1
* wBlockLength - 2
* data - 4
* sernum - 1
*/
data_len = skb->len;
if(skb_headroom(skb) < 10)
{
printk(KERN_CRIT "No headspace (%u) on headroom %p for capi header\n", skb_headroom(skb), skb);
}
else
{
skb_push(skb, 10);
}
*((u16 *) (skb->data)) = chan->callref;
skb->data[2] = chan->layer2link;
*((u16 *) (skb->data + 3)) = data_len;
chan->s_refnum = (chan->s_refnum + 1) % 8;
*((u32 *) (skb->data + 5)) = chan->s_refnum;
skb->data[9] = 0; /* HDLC frame number */
return 10;
}
int capi_tdata_resp(struct pcbit_chan *chan, struct sk_buff ** skb)
{
if ((*skb = dev_alloc_skb(4)) == NULL) {
printk(KERN_WARNING "capi_tdata_resp: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
*(skb_put(*skb, 1)) = chan->layer2link;
*(skb_put(*skb, 1)) = chan->r_refnum;
return (*skb)->len;
}
int capi_disc_req(ushort callref, struct sk_buff **skb, u_char cause)
{
if ((*skb = dev_alloc_skb(6)) == NULL) {
printk(KERN_WARNING "capi_disc_req: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = callref;
*(skb_put(*skb, 1)) = 2; /* Cause.Length = 2; */
*(skb_put(*skb, 1)) = 0x80;
*(skb_put(*skb, 1)) = 0x80 | cause;
/*
* Change it: we should send 'Sic transit gloria Mundi' here ;-)
*/
*(skb_put(*skb, 1)) = 0; /* UTUS.Length = 0; */
return 6;
}
int capi_disc_resp(struct pcbit_chan *chan, struct sk_buff **skb)
{
if ((*skb = dev_alloc_skb(2)) == NULL) {
printk(KERN_WARNING "capi_disc_resp: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2)) = chan->callref;
return 2;
}
/*
* Decoding of CAPI messages
*
*/
int capi_decode_conn_ind(struct pcbit_chan * chan,
struct sk_buff *skb,
struct callb_data *info)
{
int CIlen, len;
/* Call Reference [CAPI] */
chan->callref = *((ushort*) skb->data);
skb_pull(skb, 2);
#ifdef DEBUG
printk(KERN_DEBUG "Call Reference: %04x\n", chan->callref);
#endif
/* Channel Identification */
/* Expect
Len = 1
Octect 3 = 0100 10CC - [ 7 Basic, 4 , 2-1 chan ]
*/
CIlen = skb->data[0];
#ifdef DEBUG
if (CIlen == 1) {
if ( ((skb->data[1]) & 0xFC) == 0x48 )
printk(KERN_DEBUG "decode_conn_ind: chan ok\n");
printk(KERN_DEBUG "phyChan = %d\n", skb->data[1] & 0x03);
}
else
printk(KERN_DEBUG "conn_ind: CIlen = %d\n", CIlen);
#endif
skb_pull(skb, CIlen + 1);
/* Calling Party Number */
/* An "additional service" as far as Portugal Telecom is concerned */
len = skb->data[0];
if (len > 0) {
int count = 1;
#ifdef DEBUG
printk(KERN_DEBUG "CPN: Octect 3 %02x\n", skb->data[1]);
#endif
if ((skb->data[1] & 0x80) == 0)
count = 2;
if (!(info->data.setup.CallingPN = kmalloc(len - count + 1, GFP_ATOMIC)))
return -1;
memcpy(info->data.setup.CallingPN, skb->data + count + 1,
len - count);
info->data.setup.CallingPN[len - count] = 0;
}
else {
info->data.setup.CallingPN = NULL;
printk(KERN_DEBUG "NULL CallingPN\n");
}
skb_pull(skb, len + 1);
/* Calling Party Subaddress */
skb_pull(skb, skb->data[0] + 1);
/* Called Party Number */
len = skb->data[0];
if (len > 0) {
int count = 1;
if ((skb->data[1] & 0x80) == 0)
count = 2;
if (!(info->data.setup.CalledPN = kmalloc(len - count + 1, GFP_ATOMIC)))
return -1;
memcpy(info->data.setup.CalledPN, skb->data + count + 1,
len - count);
info->data.setup.CalledPN[len - count] = 0;
}
else {
info->data.setup.CalledPN = NULL;
printk(KERN_DEBUG "NULL CalledPN\n");
}
skb_pull(skb, len + 1);
/* Called Party Subaddress */
skb_pull(skb, skb->data[0] + 1);
/* LLC */
skb_pull(skb, skb->data[0] + 1);
/* HLC */
skb_pull(skb, skb->data[0] + 1);
/* U2U */
skb_pull(skb, skb->data[0] + 1);
return 0;
}
/*
* returns errcode
*/
int capi_decode_conn_conf(struct pcbit_chan * chan, struct sk_buff *skb,
int *complete)
{
int errcode;
chan->callref = *((ushort *) skb->data); /* Update CallReference */
skb_pull(skb, 2);
errcode = *((ushort *) skb->data); /* read errcode */
skb_pull(skb, 2);
*complete = *(skb->data);
skb_pull(skb, 1);
/* FIX ME */
/* This is actually a firmware bug */
if (!*complete)
{
printk(KERN_DEBUG "complete=%02x\n", *complete);
*complete = 1;
}
/* Optional Bearer Capability */
skb_pull(skb, *(skb->data) + 1);
/* Channel Identification */
skb_pull(skb, *(skb->data) + 1);
/* High Layer Compatibility follows */
skb_pull(skb, *(skb->data) + 1);
return errcode;
}
int capi_decode_conn_actv_ind(struct pcbit_chan * chan, struct sk_buff *skb)
{
ushort len;
#ifdef DEBUG
char str[32];
#endif
/* Yet Another Bearer Capability */
skb_pull(skb, *(skb->data) + 1);
/* Connected Party Number */
len=*(skb->data);
#ifdef DEBUG
if (len > 1 && len < 31) {
memcpy(str, skb->data + 2, len - 1);
str[len] = 0;
printk(KERN_DEBUG "Connected Party Number: %s\n", str);
}
else
printk(KERN_DEBUG "actv_ind CPN len = %d\n", len);
#endif
skb_pull(skb, len + 1);
/* Connected Subaddress */
skb_pull(skb, *(skb->data) + 1);
/* Low Layer Capability */
skb_pull(skb, *(skb->data) + 1);
/* High Layer Capability */
skb_pull(skb, *(skb->data) + 1);
return 0;
}
int capi_decode_conn_actv_conf(struct pcbit_chan * chan, struct sk_buff *skb)
{
ushort errcode;
errcode = *((ushort*) skb->data);
skb_pull(skb, 2);
/* Channel Identification
skb_pull(skb, skb->data[0] + 1);
*/
return errcode;
}
int capi_decode_sel_proto_conf(struct pcbit_chan *chan, struct sk_buff *skb)
{
ushort errcode;
chan->layer2link = *(skb->data);
skb_pull(skb, 1);
errcode = *((ushort*) skb->data);
skb_pull(skb, 2);
return errcode;
}
int capi_decode_actv_trans_conf(struct pcbit_chan *chan, struct sk_buff *skb)
{
ushort errcode;
if (chan->layer2link != *(skb->data) )
printk("capi_decode_actv_trans_conf: layer2link doesn't match\n");
skb_pull(skb, 1);
errcode = *((ushort*) skb->data);
skb_pull(skb, 2);
return errcode;
}
int capi_decode_disc_ind(struct pcbit_chan *chan, struct sk_buff *skb)
{
ushort len;
#ifdef DEBUG
int i;
#endif
/* Cause */
len = *(skb->data);
skb_pull(skb, 1);
#ifdef DEBUG
for (i=0; i<len; i++)
printk(KERN_DEBUG "Cause Octect %d: %02x\n", i+3,
*(skb->data + i));
#endif
skb_pull(skb, len);
return 0;
}
#ifdef DEBUG
int capi_decode_debug_188(u_char *hdr, ushort hdrlen)
{
char str[64];
int len;
len = hdr[0];
if (len < 64 && len == hdrlen - 1) {
memcpy(str, hdr + 1, hdrlen - 1);
str[hdrlen - 1] = 0;
printk("%s\n", str);
}
else
printk("debug message incorrect\n");
return 0;
}
#endif
|
