drivers/isdn/pcbit/capi.c

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