LXR linux-bk/net/irda/parameters.c

   1/*********************************************************************
   2 *
   3 * Filename:      parameters.c
   4 * Version:       1.0
   5 * Description:   A more general way to handle (pi,pl,pv) parameters
   6 * Status:        Experimental.
   7 * Author:        Dag Brattli <dagb@cs.uit.no>
   8 * Created at:    Mon Jun  7 10:25:11 1999
   9 * Modified at:   Sun Jan 30 14:08:39 2000
  10 * Modified by:   Dag Brattli <dagb@cs.uit.no>
  11 *
  12 *     Copyright (c) 1999-2000 Dag Brattli, All Rights Reserved.
  13 *
  14 *     This program is free software; you can redistribute it and/or
  15 *     modify it under the terms of the GNU General Public License as
  16 *     published by the Free Software Foundation; either version 2 of
  17 *     the License, or (at your option) any later version.
  18 *
  19 *     This program is distributed in the hope that it will be useful,
  20 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  22 *     GNU General Public License for more details.
  23 *
  24 *     You should have received a copy of the GNU General Public License
  25 *     along with this program; if not, write to the Free Software
  26 *     Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  27 *     MA 02111-1307 USA
  28 *
  29 ********************************************************************/
  30
  31#include <linux/types.h>
  32#include <linux/module.h>
  33
  34#include <asm/unaligned.h>
  35#include <asm/byteorder.h>
  36
  37#include <net/irda/irda.h>
  38#include <net/irda/parameters.h>
  39
  40static int irda_extract_integer(void *self, __u8 *buf, int len, __u8 pi,
  41                                PV_TYPE type, PI_HANDLER func);
  42static int irda_extract_string(void *self, __u8 *buf, int len, __u8 pi,
  43                               PV_TYPE type, PI_HANDLER func);
  44static int irda_extract_octseq(void *self, __u8 *buf, int len, __u8 pi,
  45                               PV_TYPE type, PI_HANDLER func);
  46static int irda_extract_no_value(void *self, __u8 *buf, int len, __u8 pi,
  47                                 PV_TYPE type, PI_HANDLER func);
  48
  49static int irda_insert_integer(void *self, __u8 *buf, int len, __u8 pi,
  50                               PV_TYPE type, PI_HANDLER func);
  51static int irda_insert_no_value(void *self, __u8 *buf, int len, __u8 pi,
  52                                PV_TYPE type, PI_HANDLER func);
  53
  54static int irda_param_unpack(__u8 *buf, char *fmt, ...);
  55
  56/* Parameter value call table. Must match PV_TYPE */
  57static PV_HANDLER pv_extract_table[] = {
  58        irda_extract_integer, /* Handler for any length integers */
  59        irda_extract_integer, /* Handler for 8  bits integers */
  60        irda_extract_integer, /* Handler for 16 bits integers */
  61        irda_extract_string,  /* Handler for strings */
  62        irda_extract_integer, /* Handler for 32 bits integers */
  63        irda_extract_octseq,  /* Handler for octet sequences */
  64        irda_extract_no_value /* Handler for no value parameters */
  65};
  66
  67static PV_HANDLER pv_insert_table[] = {
  68        irda_insert_integer, /* Handler for any length integers */
  69        irda_insert_integer, /* Handler for 8  bits integers */
  70        irda_insert_integer, /* Handler for 16 bits integers */
  71        NULL,                /* Handler for strings */
  72        irda_insert_integer, /* Handler for 32 bits integers */
  73        NULL,                /* Handler for octet sequences */
  74        irda_insert_no_value /* Handler for no value parameters */
  75};
  76
  77/*
  78 * Function irda_insert_no_value (self, buf, len, pi, type, func)
  79 */
  80static int irda_insert_no_value(void *self, __u8 *buf, int len, __u8 pi,
  81                                PV_TYPE type, PI_HANDLER func)
  82{
  83        irda_param_t p;
  84        int ret;
  85
  86        p.pi = pi;
  87        p.pl = 0;
  88
  89        /* Call handler for this parameter */
  90        ret = (*func)(self, &p, PV_GET);
  91
  92        /* Extract values anyway, since handler may need them */
  93        irda_param_pack(buf, "bb", p.pi, p.pl);
  94
  95        if (ret < 0)
  96                return ret;
  97
  98        return 2; /* Inserted pl+2 bytes */
  99}
 100
 101/*
 102 * Function irda_extract_no_value (self, buf, len, type, func)
 103 *
 104 *    Extracts a parameter without a pv field (pl=0)
 105 *
 106 */
 107static int irda_extract_no_value(void *self, __u8 *buf, int len, __u8 pi,
 108                                 PV_TYPE type, PI_HANDLER func)
 109{
 110        irda_param_t p;
 111        int ret;
 112
 113        /* Extract values anyway, since handler may need them */
 114        irda_param_unpack(buf, "bb", &p.pi, &p.pl);
 115
 116        /* Call handler for this parameter */
 117        ret = (*func)(self, &p, PV_PUT);
 118
 119        if (ret < 0)
 120                return ret;
 121
 122        return 2; /* Extracted pl+2 bytes */
 123}
 124
 125/*
 126 * Function irda_insert_integer (self, buf, len, pi, type, func)
 127 */
 128static int irda_insert_integer(void *self, __u8 *buf, int len, __u8 pi,
 129                               PV_TYPE type, PI_HANDLER func)
 130{
 131        irda_param_t p;
 132        int n = 0;
 133        int err;
 134
 135        p.pi = pi;             /* In case handler needs to know */
 136        p.pl = type & PV_MASK; /* The integer type codes the lenght as well */
 137        p.pv.i = 0;            /* Clear value */
 138
 139        /* Call handler for this parameter */
 140        err = (*func)(self, &p, PV_GET);
 141        if (err < 0)
 142                return err;
 143
 144        /*
 145         * If parameter lenght is still 0, then (1) this is an any length
 146         * integer, and (2) the handler function does not care which length
 147         * we choose to use, so we pick the one the gives the fewest bytes.
 148         */
 149        if (p.pl == 0) {
 150                if (p.pv.i < 0xff) {
 151                        IRDA_DEBUG(2, "%s(), using 1 byte\n", __FUNCTION__);
 152                        p.pl = 1;
 153                } else if (p.pv.i < 0xffff) {
 154                        IRDA_DEBUG(2, "%s(), using 2 bytes\n", __FUNCTION__);
 155                        p.pl = 2;
 156                } else {
 157                        IRDA_DEBUG(2, "%s(), using 4 bytes\n", __FUNCTION__);
 158                        p.pl = 4; /* Default length */
 159                }
 160        }
 161        /* Check if buffer is long enough for insertion */
 162        if (len < (2+p.pl)) {
 163                WARNING("%s: buffer to short for insertion!\n", __FUNCTION__);
 164                return -1;
 165        }
 166        IRDA_DEBUG(2, "%s(), pi=%#x, pl=%d, pi=%d\n", __FUNCTION__,
 167                   p.pi, p.pl, p.pv.i);
 168        switch (p.pl) {
 169        case 1:
 170                n += irda_param_pack(buf, "bbb", p.pi, p.pl, (__u8) p.pv.i);
 171                break;
 172        case 2:
 173                if (type & PV_BIG_ENDIAN)
 174                        p.pv.i = cpu_to_be16((__u16) p.pv.i);
 175                else
 176                        p.pv.i = cpu_to_le16((__u16) p.pv.i);
 177                n += irda_param_pack(buf, "bbs", p.pi, p.pl, (__u16) p.pv.i);
 178                break;
 179        case 4:
 180                if (type & PV_BIG_ENDIAN)
 181                        cpu_to_be32s(&p.pv.i);
 182                else
 183                        cpu_to_le32s(&p.pv.i);
 184                n += irda_param_pack(buf, "bbi", p.pi, p.pl, p.pv.i);
 185
 186                break;
 187        default:
 188                WARNING("%s: length %d not supported\n", __FUNCTION__, p.pl);
 189                /* Skip parameter */
 190                return -1;
 191        }
 192
 193        return p.pl+2; /* Inserted pl+2 bytes */
 194}
 195
 196/*
 197 * Function irda_extract integer (self, buf, len, pi, type, func)
 198 *
 199 *    Extract a possibly variable length integer from buffer, and call
 200 *    handler for processing of the parameter
 201 */
 202static int irda_extract_integer(void *self, __u8 *buf, int len, __u8 pi,
 203                                PV_TYPE type, PI_HANDLER func)
 204{
 205        irda_param_t p;
 206        int n = 0;
 207        int extract_len;        /* Real lenght we extract */
 208        int err;
 209
 210        p.pi = pi;     /* In case handler needs to know */
 211        p.pl = buf[1]; /* Extract lenght of value */
 212        p.pv.i = 0;    /* Clear value */
 213        extract_len = p.pl;     /* Default : extract all */
 214
 215        /* Check if buffer is long enough for parsing */
 216        if (len < (2+p.pl)) {
 217                WARNING("%s: buffer to short for parsing! "
 218                        "Need %d bytes, but len is only %d\n",
 219                        __FUNCTION__, p.pl, len);
 220                return -1;
 221        }
 222
 223        /*
 224         * Check that the integer length is what we expect it to be. If the
 225         * handler want a 16 bits integer then a 32 bits is not good enough
 226         * PV_INTEGER means that the handler is flexible.
 227         */
 228        if (((type & PV_MASK) != PV_INTEGER) && ((type & PV_MASK) != p.pl)) {
 229                ERROR("%s: invalid parameter length! "
 230                      "Expected %d bytes, but value had %d bytes!\n",
 231                      __FUNCTION__, type & PV_MASK, p.pl);
 232
 233                /* Most parameters are bit/byte fields or little endian,
 234                 * so it's ok to only extract a subset of it (the subset
 235                 * that the handler expect). This is necessary, as some
 236                 * broken implementations seems to add extra undefined bits.
 237                 * If the parameter is shorter than we expect or is big
 238                 * endian, we can't play those tricks. Jean II */
 239                if((p.pl < (type & PV_MASK)) || (type & PV_BIG_ENDIAN)) {
 240                        /* Skip parameter */
 241                        return p.pl+2;
 242                } else {
 243                        /* Extract subset of it, fallthrough */
 244                        extract_len = type & PV_MASK;
 245                }
 246        }
 247
 248
 249        switch (extract_len) {
 250        case 1:
 251                n += irda_param_unpack(buf+2, "b", &p.pv.i);
 252                break;
 253        case 2:
 254                n += irda_param_unpack(buf+2, "s", &p.pv.i);
 255                if (type & PV_BIG_ENDIAN)
 256                        p.pv.i = be16_to_cpu((__u16) p.pv.i);
 257                else
 258                        p.pv.i = le16_to_cpu((__u16) p.pv.i);
 259                break;
 260        case 4:
 261                n += irda_param_unpack(buf+2, "i", &p.pv.i);
 262                if (type & PV_BIG_ENDIAN)
 263                        be32_to_cpus(&p.pv.i);
 264                else
 265                        le32_to_cpus(&p.pv.i);
 266                break;
 267        default:
 268                WARNING("%s: length %d not supported\n", __FUNCTION__, p.pl);
 269
 270                /* Skip parameter */
 271                return p.pl+2;
 272        }
 273
 274        IRDA_DEBUG(2, "%s(), pi=%#x, pl=%d, pi=%d\n", __FUNCTION__,
 275                   p.pi, p.pl, p.pv.i);
 276        /* Call handler for this parameter */
 277        err = (*func)(self, &p, PV_PUT);
 278        if (err < 0)
 279                return err;
 280
 281        return p.pl+2; /* Extracted pl+2 bytes */
 282}
 283
 284/*
 285 * Function irda_extract_string (self, buf, len, type, func)
 286 */
 287static int irda_extract_string(void *self, __u8 *buf, int len, __u8 pi,
 288                               PV_TYPE type, PI_HANDLER func)
 289{
 290        char str[33];
 291        irda_param_t p;
 292        int err;
 293
 294        IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
 295
 296        p.pi = pi;     /* In case handler needs to know */
 297        p.pl = buf[1]; /* Extract lenght of value */
 298
 299        IRDA_DEBUG(2, "%s(), pi=%#x, pl=%d\n", __FUNCTION__,
 300                   p.pi, p.pl);
 301
 302        /* Check if buffer is long enough for parsing */
 303        if (len < (2+p.pl)) {
 304                WARNING("%s: buffer to short for parsing! "
 305                        "Need %d bytes, but len is only %d\n",
 306                        __FUNCTION__, p.pl, len);
 307                return -1;
 308        }
 309
 310        /* Should be safe to copy string like this since we have already
 311         * checked that the buffer is long enough */
 312        strncpy(str, buf+2, p.pl);
 313
 314        IRDA_DEBUG(2, "%s(), str=0x%02x 0x%02x\n", __FUNCTION__,
 315                   (__u8) str[0], (__u8) str[1]);
 316
 317        /* Null terminate string */
 318        str[p.pl+1] = '\0';
 319
 320        p.pv.c = str; /* Handler will need to take a copy */
 321
 322        /* Call handler for this parameter */
 323        err = (*func)(self, &p, PV_PUT);
 324        if (err < 0)
 325                return err;
 326
 327        return p.pl+2; /* Extracted pl+2 bytes */
 328}
 329
 330/*
 331 * Function irda_extract_octseq (self, buf, len, type, func)
 332 */
 333static int irda_extract_octseq(void *self, __u8 *buf, int len, __u8 pi,
 334                               PV_TYPE type, PI_HANDLER func)
 335{
 336        irda_param_t p;
 337
 338        p.pi = pi;     /* In case handler needs to know */
 339        p.pl = buf[1]; /* Extract lenght of value */
 340
 341        /* Check if buffer is long enough for parsing */
 342        if (len < (2+p.pl)) {
 343                WARNING("%s: buffer to short for parsing! "
 344                        "Need %d bytes, but len is only %d\n",
 345                        __FUNCTION__, p.pl, len);
 346                return -1;
 347        }
 348
 349        IRDA_DEBUG(0, "%s(), not impl\n", __FUNCTION__);
 350
 351        return p.pl+2; /* Extracted pl+2 bytes */
 352}
 353
 354/*
 355 * Function irda_param_pack (skb, fmt, ...)
 356 *
 357 *    Format:
 358 *        'i' = 32 bits integer
 359 *        's' = string
 360 *
 361 */
 362int irda_param_pack(__u8 *buf, char *fmt, ...)
 363{
 364        irda_pv_t arg;
 365        va_list args;
 366        char *p;
 367        int n = 0;
 368
 369        va_start(args, fmt);
 370
 371        for (p = fmt; *p != '\0'; p++) {
 372                switch (*p) {
 373                case 'b':  /* 8 bits unsigned byte */
 374                        buf[n++] = (__u8)va_arg(args, int);
 375                        break;
 376                case 's':  /* 16 bits unsigned short */
 377                        arg.i = (__u16)va_arg(args, int);
 378                        put_unaligned((__u16)arg.i, (__u16 *)(buf+n)); n+=2;
 379                        break;
 380                case 'i':  /* 32 bits unsigned integer */
 381                        arg.i = va_arg(args, __u32);
 382                        put_unaligned(arg.i, (__u32 *)(buf+n)); n+=4;
 383                        break;
 384#if 0
 385                case 'c': /* \0 terminated string */
 386                        arg.c = va_arg(args, char *);
 387                        strcpy(buf+n, arg.c);
 388                        n += strlen(arg.c) + 1;
 389                        break;
 390#endif
 391                default:
 392                        va_end(args);
 393                        return -1;
 394                }
 395        }
 396        va_end(args);
 397
 398        return 0;
 399}
 400EXPORT_SYMBOL(irda_param_pack);
 401
 402/*
 403 * Function irda_param_unpack (skb, fmt, ...)
 404 */
 405static int irda_param_unpack(__u8 *buf, char *fmt, ...)
 406{
 407        irda_pv_t arg;
 408        va_list args;
 409        char *p;
 410        int n = 0;
 411
 412        va_start(args, fmt);
 413
 414        for (p = fmt; *p != '\0'; p++) {
 415                switch (*p) {
 416                case 'b':  /* 8 bits byte */
 417                        arg.ip = va_arg(args, __u32 *);
 418                        *arg.ip = buf[n++];
 419                        break;
 420                case 's':  /* 16 bits short */
 421                        arg.ip = va_arg(args, __u32 *);
 422                        *arg.ip = get_unaligned((__u16 *)(buf+n)); n+=2;
 423                        break;
 424                case 'i':  /* 32 bits unsigned integer */
 425                        arg.ip = va_arg(args, __u32 *);
 426                        *arg.ip = get_unaligned((__u32 *)(buf+n)); n+=4;
 427                        break;
 428#if 0
 429                case 'c':   /* \0 terminated string */
 430                        arg.c = va_arg(args, char *);
 431                        strcpy(arg.c, buf+n);
 432                        n += strlen(arg.c) + 1;
 433                        break;
 434#endif
 435                default:
 436                        va_end(args);
 437                        return -1;
 438                }
 439
 440        }
 441        va_end(args);
 442
 443        return 0;
 444}
 445
 446/*
 447 * Function irda_param_insert (self, pi, buf, len, info)
 448 *
 449 *    Insert the specified parameter (pi) into buffer. Returns number of
 450 *    bytes inserted
 451 */
 452int irda_param_insert(void *self, __u8 pi, __u8 *buf, int len,
 453                      pi_param_info_t *info)
 454{
 455        pi_minor_info_t *pi_minor_info;
 456        __u8 pi_minor;
 457        __u8 pi_major;
 458        int type;
 459        int ret = -1;
 460        int n = 0;
 461
 462        ASSERT(buf != NULL, return ret;);
 463        ASSERT(info != 0, return ret;);
 464
 465        pi_minor = pi & info->pi_mask;
 466        pi_major = pi >> info->pi_major_offset;
 467
 468        /* Check if the identifier value (pi) is valid */
 469        if ((pi_major > info->len-1) ||
 470            (pi_minor > info->tables[pi_major].len-1))
 471        {
 472                IRDA_DEBUG(0, "%s(), no handler for parameter=0x%02x\n",
 473                           __FUNCTION__, pi);
 474
 475                /* Skip this parameter */
 476                return -1;
 477        }
 478
 479        /* Lookup the info on how to parse this parameter */
 480        pi_minor_info = &info->tables[pi_major].pi_minor_call_table[pi_minor];
 481
 482        /* Find expected data type for this parameter identifier (pi)*/
 483        type = pi_minor_info->type;
 484
 485        /*  Check if handler has been implemented */
 486        if (!pi_minor_info->func) {
 487                MESSAGE("%s: no handler for pi=%#x\n", __FUNCTION__, pi);
 488                /* Skip this parameter */
 489                return -1;
 490        }
 491
 492        /* Insert parameter value */
 493        ret = (*pv_insert_table[type & PV_MASK])(self, buf+n, len, pi, type,
 494                                                 pi_minor_info->func);
 495        return ret;
 496}
 497EXPORT_SYMBOL(irda_param_insert);
 498
 499/*
 500 * Function irda_param_extract (self, buf, len, info)
 501 *
 502 *    Parse all parameters. If len is correct, then everything should be
 503 *    safe. Returns the number of bytes that was parsed
 504 *
 505 */
 506static int irda_param_extract(void *self, __u8 *buf, int len,
 507                              pi_param_info_t *info)
 508{
 509        pi_minor_info_t *pi_minor_info;
 510        __u8 pi_minor;
 511        __u8 pi_major;
 512        int type;
 513        int ret = -1;
 514        int n = 0;
 515
 516        ASSERT(buf != NULL, return ret;);
 517        ASSERT(info != 0, return ret;);
 518
 519        pi_minor = buf[n] & info->pi_mask;
 520        pi_major = buf[n] >> info->pi_major_offset;
 521
 522        /* Check if the identifier value (pi) is valid */
 523        if ((pi_major > info->len-1) ||
 524            (pi_minor > info->tables[pi_major].len-1))
 525        {
 526                IRDA_DEBUG(0, "%s(), no handler for parameter=0x%02x\n",
 527                           __FUNCTION__, buf[0]);
 528
 529                /* Skip this parameter */
 530                return 2 + buf[n + 1];  /* Continue */
 531        }
 532
 533        /* Lookup the info on how to parse this parameter */
 534        pi_minor_info = &info->tables[pi_major].pi_minor_call_table[pi_minor];
 535
 536        /* Find expected data type for this parameter identifier (pi)*/
 537        type = pi_minor_info->type;
 538
 539        IRDA_DEBUG(3, "%s(), pi=[%d,%d], type=%d\n", __FUNCTION__,
 540                   pi_major, pi_minor, type);
 541
 542        /*  Check if handler has been implemented */
 543        if (!pi_minor_info->func) {
 544                MESSAGE("%s: no handler for pi=%#x\n", __FUNCTION__, buf[n]);
 545                /* Skip this parameter */
 546                return 2 + buf[n + 1]; /* Continue */
 547        }
 548
 549        /* Parse parameter value */
 550        ret = (*pv_extract_table[type & PV_MASK])(self, buf+n, len, buf[n],
 551                                                  type, pi_minor_info->func);
 552        return ret;
 553}
 554
 555/*
 556 * Function irda_param_extract_all (self, buf, len, info)
 557 *
 558 *    Parse all parameters. If len is correct, then everything should be
 559 *    safe. Returns the number of bytes that was parsed
 560 *
 561 */
 562int irda_param_extract_all(void *self, __u8 *buf, int len, 
 563                           pi_param_info_t *info)
 564{
 565        int ret = -1;
 566        int n = 0;
 567
 568        ASSERT(buf != NULL, return ret;);
 569        ASSERT(info != 0, return ret;);
 570
 571        /*
 572         * Parse all parameters. Each parameter must be at least two bytes
 573         * long or else there is no point in trying to parse it
 574         */
 575        while (len > 2) {
 576                ret = irda_param_extract(self, buf+n, len, info);
 577                if (ret < 0)
 578                        return ret;
 579
 580                n += ret;
 581                len -= ret;
 582        }
 583        return n;
 584}
 585EXPORT_SYMBOL(irda_param_extract_all);
 586