cvs.zerfleddert.de Git - proxmark3-svn/blob - client/jansson/load.c

   1 /*
   2  * Copyright (c) 2009-2016 Petri Lehtinen <petri@digip.org>
   3  *
   4  * Jansson is free software; you can redistribute it and/or modify
   5  * it under the terms of the MIT license. See LICENSE for details.
   6  */
   7
   8 #ifndef _GNU_SOURCE
   9 #define _GNU_SOURCE
  10 #endif
  11
  12 #include "jansson_private.h"
  13
  14 #include <errno.h>
  15 #include <limits.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <assert.h>
  20 #ifdef HAVE_UNISTD_H
  21 #include <unistd.h>
  22 #endif
  23
  24 #include "jansson.h"
  25 #include "strbuffer.h"
  26 #include "utf.h"
  27
  28 #define STREAM_STATE_OK        0
  29 #define STREAM_STATE_EOF      -1
  30 #define STREAM_STATE_ERROR    -2
  31
  32 #define TOKEN_INVALID         -1
  33 #define TOKEN_EOF              0
  34 #define TOKEN_STRING         256
  35 #define TOKEN_INTEGER        257
  36 #define TOKEN_REAL           258
  37 #define TOKEN_TRUE           259
  38 #define TOKEN_FALSE          260
  39 #define TOKEN_NULL           261
  40
  41 /* Locale independent versions of isxxx() functions */
  42 #define l_isupper(c)  ('A' <= (c) && (c) <= 'Z')
  43 #define l_islower(c)  ('a' <= (c) && (c) <= 'z')
  44 #define l_isalpha(c)  (l_isupper(c) || l_islower(c))
  45 #define l_isdigit(c)  ('0' <= (c) && (c) <= '9')
  46 #define l_isxdigit(c) \
  47     (l_isdigit(c) || ('A' <= (c) && (c) <= 'F') || ('a' <= (c) && (c) <= 'f'))
  48
  49 /* Read one byte from stream, convert to unsigned char, then int, and
  50    return. return EOF on end of file. This corresponds to the
  51    behaviour of fgetc(). */
  52 typedef int (*get_func)(void *data);
  53
  54 typedef struct {
  55     get_func get;
  56     void *data;
  57     char buffer[5];
  58     size_t buffer_pos;
  59     int state;
  60     int line;
  61     int column, last_column;
  62     size_t position;
  63 } stream_t;
  64
  65 typedef struct {
  66     stream_t stream;
  67     strbuffer_t saved_text;
  68     size_t flags;
  69     size_t depth;
  70     int token;
  71     union {
  72         struct {
  73             char *val;
  74             size_t len;
  75         } string;
  76         json_int_t integer;
  77         double real;
  78     } value;
  79 } lex_t;
  80
  81 #define stream_to_lex(stream) container_of(stream, lex_t, stream)
  82
  83
  84 /*** error reporting ***/
  85
  86 static void error_set(json_error_t *error, const lex_t *lex,
  87                       enum json_error_code code,
  88                       const char *msg, ...)
  89 {
  90     va_list ap;
  91     char msg_text[JSON_ERROR_TEXT_LENGTH];
  92     char msg_with_context[JSON_ERROR_TEXT_LENGTH];
  93
  94     int line = -1, col = -1;
  95     size_t pos = 0;
  96     const char *result = msg_text;
  97
  98     if(!error)
  99         return;
 100
 101     va_start(ap, msg);
 102     vsnprintf(msg_text, JSON_ERROR_TEXT_LENGTH, msg, ap);
 103     msg_text[JSON_ERROR_TEXT_LENGTH - 1] = '\0';
 104     va_end(ap);
 105
 106     if(lex)
 107     {
 108         const char *saved_text = strbuffer_value(&lex->saved_text);
 109
 110         line = lex->stream.line;
 111         col = lex->stream.column;
 112         pos = lex->stream.position;
 113
 114         if(saved_text && saved_text[0])
 115         {
 116             if(lex->saved_text.length <= 20) {
 117                 snprintf(msg_with_context, JSON_ERROR_TEXT_LENGTH,
 118                          "%s near '%s'", msg_text, saved_text);
 119                 msg_with_context[JSON_ERROR_TEXT_LENGTH - 1] = '\0';
 120                 result = msg_with_context;
 121             }
 122         }
 123         else
 124         {
 125             if(code == json_error_invalid_syntax) {
 126                 /* More specific error code for premature end of file. */
 127                 code = json_error_premature_end_of_input;
 128             }
 129             if(lex->stream.state == STREAM_STATE_ERROR) {
 130                 /* No context for UTF-8 decoding errors */
 131                 result = msg_text;
 132             }
 133             else {
 134                 snprintf(msg_with_context, JSON_ERROR_TEXT_LENGTH,
 135                          "%s near end of file", msg_text);
 136                 msg_with_context[JSON_ERROR_TEXT_LENGTH - 1] = '\0';
 137                 result = msg_with_context;
 138             }
 139         }
 140     }
 141
 142     jsonp_error_set(error, line, col, pos, code, "%s", result);
 143 }
 144
 145
 146 /*** lexical analyzer ***/
 147
 148 static void
 149 stream_init(stream_t *stream, get_func get, void *data)
 150 {
 151     stream->get = get;
 152     stream->data = data;
 153     stream->buffer[0] = '\0';
 154     stream->buffer_pos = 0;
 155
 156     stream->state = STREAM_STATE_OK;
 157     stream->line = 1;
 158     stream->column = 0;
 159     stream->position = 0;
 160 }
 161
 162 static int stream_get(stream_t *stream, json_error_t *error)
 163 {
 164     int c;
 165
 166     if(stream->state != STREAM_STATE_OK)
 167         return stream->state;
 168
 169     if(!stream->buffer[stream->buffer_pos])
 170     {
 171         c = stream->get(stream->data);
 172         if(c == EOF) {
 173             stream->state = STREAM_STATE_EOF;
 174             return STREAM_STATE_EOF;
 175         }
 176
 177         stream->buffer[0] = c;
 178         stream->buffer_pos = 0;
 179
 180         if(0x80 <= c && c <= 0xFF)
 181         {
 182             /* multi-byte UTF-8 sequence */
 183             size_t i, count;
 184
 185             count = utf8_check_first(c);
 186             if(!count)
 187                 goto out;
 188
 189             assert(count >= 2);
 190
 191             for(i = 1; i < count; i++)
 192                 stream->buffer[i] = stream->get(stream->data);
 193
 194             if(!utf8_check_full(stream->buffer, count, NULL))
 195                 goto out;
 196
 197             stream->buffer[count] = '\0';
 198         }
 199         else
 200             stream->buffer[1] = '\0';
 201     }
 202
 203     c = stream->buffer[stream->buffer_pos++];
 204
 205     stream->position++;
 206     if(c == '\n') {
 207         stream->line++;
 208         stream->last_column = stream->column;
 209         stream->column = 0;
 210     }
 211     else if(utf8_check_first(c)) {
 212         /* track the Unicode character column, so increment only if
 213            this is the first character of a UTF-8 sequence */
 214         stream->column++;
 215     }
 216
 217     return c;
 218
 219 out:
 220     stream->state = STREAM_STATE_ERROR;
 221     error_set(error, stream_to_lex(stream), json_error_invalid_utf8, "unable to decode byte 0x%x", c);
 222     return STREAM_STATE_ERROR;
 223 }
 224
 225 static void stream_unget(stream_t *stream, int c)
 226 {
 227     if(c == STREAM_STATE_EOF || c == STREAM_STATE_ERROR)
 228         return;
 229
 230     stream->position--;
 231     if(c == '\n') {
 232         stream->line--;
 233         stream->column = stream->last_column;
 234     }
 235     else if(utf8_check_first(c))
 236         stream->column--;
 237
 238     assert(stream->buffer_pos > 0);
 239     stream->buffer_pos--;
 240     assert(stream->buffer[stream->buffer_pos] == c);
 241 }
 242
 243
 244 static int lex_get(lex_t *lex, json_error_t *error)
 245 {
 246     return stream_get(&lex->stream, error);
 247 }
 248
 249 static void lex_save(lex_t *lex, int c)
 250 {
 251     strbuffer_append_byte(&lex->saved_text, c);
 252 }
 253
 254 static int lex_get_save(lex_t *lex, json_error_t *error)
 255 {
 256     int c = stream_get(&lex->stream, error);
 257     if(c != STREAM_STATE_EOF && c != STREAM_STATE_ERROR)
 258         lex_save(lex, c);
 259     return c;
 260 }
 261
 262 static void lex_unget(lex_t *lex, int c)
 263 {
 264     stream_unget(&lex->stream, c);
 265 }
 266
 267 static void lex_unget_unsave(lex_t *lex, int c)
 268 {
 269     if(c != STREAM_STATE_EOF && c != STREAM_STATE_ERROR) {
 270         /* Since we treat warnings as errors, when assertions are turned
 271          * off the "d" variable would be set but never used. Which is
 272          * treated as an error by GCC.
 273          */
 274         #ifndef NDEBUG
 275         char d;
 276         #endif
 277         stream_unget(&lex->stream, c);
 278         #ifndef NDEBUG
 279         d =
 280         #endif
 281             strbuffer_pop(&lex->saved_text);
 282         assert(c == d);
 283     }
 284 }
 285
 286 static void lex_save_cached(lex_t *lex)
 287 {
 288     while(lex->stream.buffer[lex->stream.buffer_pos] != '\0')
 289     {
 290         lex_save(lex, lex->stream.buffer[lex->stream.buffer_pos]);
 291         lex->stream.buffer_pos++;
 292         lex->stream.position++;
 293     }
 294 }
 295
 296 static void lex_free_string(lex_t *lex)
 297 {
 298     jsonp_free(lex->value.string.val);
 299     lex->value.string.val = NULL;
 300     lex->value.string.len = 0;
 301 }
 302
 303 /* assumes that str points to 'u' plus at least 4 valid hex digits */
 304 static int32_t decode_unicode_escape(const char *str)
 305 {
 306     int i;
 307     int32_t value = 0;
 308
 309     assert(str[0] == 'u');
 310
 311     for(i = 1; i <= 4; i++) {
 312         char c = str[i];
 313         value <<= 4;
 314         if(l_isdigit(c))
 315             value += c - '0';
 316         else if(l_islower(c))
 317             value += c - 'a' + 10;
 318         else if(l_isupper(c))
 319             value += c - 'A' + 10;
 320         else
 321             return -1;
 322     }
 323
 324     return value;
 325 }
 326
 327 static void lex_scan_string(lex_t *lex, json_error_t *error)
 328 {
 329     int c;
 330     const char *p;
 331     char *t;
 332     int i;
 333
 334     lex->value.string.val = NULL;
 335     lex->token = TOKEN_INVALID;
 336
 337     c = lex_get_save(lex, error);
 338
 339     while(c != '"') {
 340         if(c == STREAM_STATE_ERROR)
 341             goto out;
 342
 343         else if(c == STREAM_STATE_EOF) {
 344             error_set(error, lex, json_error_premature_end_of_input, "premature end of input");
 345             goto out;
 346         }
 347
 348         else if(0 <= c && c <= 0x1F) {
 349             /* control character */
 350             lex_unget_unsave(lex, c);
 351             if(c == '\n')
 352                 error_set(error, lex, json_error_invalid_syntax, "unexpected newline");
 353             else
 354                 error_set(error, lex, json_error_invalid_syntax, "control character 0x%x", c);
 355             goto out;
 356         }
 357
 358         else if(c == '\\') {
 359             c = lex_get_save(lex, error);
 360             if(c == 'u') {
 361                 c = lex_get_save(lex, error);
 362                 for(i = 0; i < 4; i++) {
 363                     if(!l_isxdigit(c)) {
 364                         error_set(error, lex, json_error_invalid_syntax, "invalid escape");
 365                         goto out;
 366                     }
 367                     c = lex_get_save(lex, error);
 368                 }
 369             }
 370             else if(c == '"' || c == '\\' || c == '/' || c == 'b' ||
 371                     c == 'f' || c == 'n' || c == 'r' || c == 't')
 372                 c = lex_get_save(lex, error);
 373             else {
 374                 error_set(error, lex, json_error_invalid_syntax, "invalid escape");
 375                 goto out;
 376             }
 377         }
 378         else
 379             c = lex_get_save(lex, error);
 380     }
 381
 382     /* the actual value is at most of the same length as the source
 383        string, because:
 384          - shortcut escapes (e.g. "\t") (length 2) are converted to 1 byte
 385          - a single \uXXXX escape (length 6) is converted to at most 3 bytes
 386          - two \uXXXX escapes (length 12) forming an UTF-16 surrogate pair
 387            are converted to 4 bytes
 388     */
 389     t = jsonp_malloc(lex->saved_text.length + 1);
 390     if(!t) {
 391         /* this is not very nice, since TOKEN_INVALID is returned */
 392         goto out;
 393     }
 394     lex->value.string.val = t;
 395
 396     /* + 1 to skip the " */
 397     p = strbuffer_value(&lex->saved_text) + 1;
 398
 399     while(*p != '"') {
 400         if(*p == '\\') {
 401             p++;
 402             if(*p == 'u') {
 403                 size_t length;
 404                 int32_t value;
 405
 406                 value = decode_unicode_escape(p);
 407                 if(value < 0) {
 408                     error_set(error, lex, json_error_invalid_syntax, "invalid Unicode escape '%.6s'", p - 1);
 409                     goto out;
 410                 }
 411                 p += 5;
 412
 413                 if(0xD800 <= value && value <= 0xDBFF) {
 414                     /* surrogate pair */
 415                     if(*p == '\\' && *(p + 1) == 'u') {
 416                         int32_t value2 = decode_unicode_escape(++p);
 417                         if(value2 < 0) {
 418                             error_set(error, lex, json_error_invalid_syntax, "invalid Unicode escape '%.6s'", p - 1);
 419                             goto out;
 420                         }
 421                         p += 5;
 422
 423                         if(0xDC00 <= value2 && value2 <= 0xDFFF) {
 424                             /* valid second surrogate */
 425                             value =
 426                                 ((value - 0xD800) << 10) +
 427                                 (value2 - 0xDC00) +
 428                                 0x10000;
 429                         }
 430                         else {
 431                             /* invalid second surrogate */
 432                             error_set(error, lex,
 433                                       json_error_invalid_syntax,
 434                                       "invalid Unicode '\\u%04X\\u%04X'",
 435                                       value, value2);
 436                             goto out;
 437                         }
 438                     }
 439                     else {
 440                         /* no second surrogate */
 441                         error_set(error, lex, json_error_invalid_syntax, "invalid Unicode '\\u%04X'",
 442                                   value);
 443                         goto out;
 444                     }
 445                 }
 446                 else if(0xDC00 <= value && value <= 0xDFFF) {
 447                     error_set(error, lex, json_error_invalid_syntax, "invalid Unicode '\\u%04X'", value);
 448                     goto out;
 449                 }
 450
 451                 if(utf8_encode(value, t, &length))
 452                     assert(0);
 453                 t += length;
 454             }
 455             else {
 456                 switch(*p) {
 457                     case '"': case '\\': case '/':
 458                         *t = *p; break;
 459                     case 'b': *t = '\b'; break;
 460                     case 'f': *t = '\f'; break;
 461                     case 'n': *t = '\n'; break;
 462                     case 'r': *t = '\r'; break;
 463                     case 't': *t = '\t'; break;
 464                     default: assert(0);
 465                 }
 466                 t++;
 467                 p++;
 468             }
 469         }
 470         else
 471             *(t++) = *(p++);
 472     }
 473     *t = '\0';
 474     lex->value.string.len = t - lex->value.string.val;
 475     lex->token = TOKEN_STRING;
 476     return;
 477
 478 out:
 479     lex_free_string(lex);
 480 }
 481
 482 #ifndef JANSSON_USING_CMAKE /* disabled if using cmake */
 483 #if JSON_INTEGER_IS_LONG_LONG
 484 #ifdef _MSC_VER  /* Microsoft Visual Studio */
 485 #define json_strtoint     _strtoi64
 486 #else
 487 #define json_strtoint     strtoll
 488 #endif
 489 #else
 490 #define json_strtoint     strtol
 491 #endif
 492 #endif
 493
 494 static int lex_scan_number(lex_t *lex, int c, json_error_t *error)
 495 {
 496     const char *saved_text;
 497     char *end;
 498     double doubleval;
 499
 500     lex->token = TOKEN_INVALID;
 501
 502     if(c == '-')
 503         c = lex_get_save(lex, error);
 504
 505     if(c == '0') {
 506         c = lex_get_save(lex, error);
 507         if(l_isdigit(c)) {
 508             lex_unget_unsave(lex, c);
 509             goto out;
 510         }
 511     }
 512     else if(l_isdigit(c)) {
 513         do
 514             c = lex_get_save(lex, error);
 515         while(l_isdigit(c));
 516     }
 517     else {
 518         lex_unget_unsave(lex, c);
 519         goto out;
 520     }
 521
 522     if(!(lex->flags & JSON_DECODE_INT_AS_REAL) &&
 523        c != '.' && c != 'E' && c != 'e')
 524     {
 525         json_int_t intval;
 526
 527         lex_unget_unsave(lex, c);
 528
 529         saved_text = strbuffer_value(&lex->saved_text);
 530
 531         errno = 0;
 532         intval = json_strtoint(saved_text, &end, 10);
 533         if(errno == ERANGE) {
 534             if(intval < 0)
 535                 error_set(error, lex, json_error_numeric_overflow, "too big negative integer");
 536             else
 537                 error_set(error, lex, json_error_numeric_overflow, "too big integer");
 538             goto out;
 539         }
 540
 541         assert(end == saved_text + lex->saved_text.length);
 542
 543         lex->token = TOKEN_INTEGER;
 544         lex->value.integer = intval;
 545         return 0;
 546     }
 547
 548     if(c == '.') {
 549         c = lex_get(lex, error);
 550         if(!l_isdigit(c)) {
 551             lex_unget(lex, c);
 552             goto out;
 553         }
 554         lex_save(lex, c);
 555
 556         do
 557             c = lex_get_save(lex, error);
 558         while(l_isdigit(c));
 559     }
 560
 561     if(c == 'E' || c == 'e') {
 562         c = lex_get_save(lex, error);
 563         if(c == '+' || c == '-')
 564             c = lex_get_save(lex, error);
 565
 566         if(!l_isdigit(c)) {
 567             lex_unget_unsave(lex, c);
 568             goto out;
 569         }
 570
 571         do
 572             c = lex_get_save(lex, error);
 573         while(l_isdigit(c));
 574     }
 575
 576     lex_unget_unsave(lex, c);
 577
 578     if(jsonp_strtod(&lex->saved_text, &doubleval)) {
 579         error_set(error, lex, json_error_numeric_overflow, "real number overflow");
 580         goto out;
 581     }
 582
 583     lex->token = TOKEN_REAL;
 584     lex->value.real = doubleval;
 585     return 0;
 586
 587 out:
 588     return -1;
 589 }
 590
 591 static int lex_scan(lex_t *lex, json_error_t *error)
 592 {
 593     int c;
 594
 595     strbuffer_clear(&lex->saved_text);
 596
 597     if(lex->token == TOKEN_STRING)
 598         lex_free_string(lex);
 599
 600     do
 601         c = lex_get(lex, error);
 602     while(c == ' ' || c == '\t' || c == '\n' || c == '\r');
 603
 604     if(c == STREAM_STATE_EOF) {
 605         lex->token = TOKEN_EOF;
 606         goto out;
 607     }
 608
 609     if(c == STREAM_STATE_ERROR) {
 610         lex->token = TOKEN_INVALID;
 611         goto out;
 612     }
 613
 614     lex_save(lex, c);
 615
 616     if(c == '{' || c == '}' || c == '[' || c == ']' || c == ':' || c == ',')
 617         lex->token = c;
 618
 619     else if(c == '"')
 620         lex_scan_string(lex, error);
 621
 622     else if(l_isdigit(c) || c == '-') {
 623         if(lex_scan_number(lex, c, error))
 624             goto out;
 625     }
 626
 627     else if(l_isalpha(c)) {
 628         /* eat up the whole identifier for clearer error messages */
 629         const char *saved_text;
 630
 631         do
 632             c = lex_get_save(lex, error);
 633         while(l_isalpha(c));
 634         lex_unget_unsave(lex, c);
 635
 636         saved_text = strbuffer_value(&lex->saved_text);
 637
 638         if(strcmp(saved_text, "true") == 0)
 639             lex->token = TOKEN_TRUE;
 640         else if(strcmp(saved_text, "false") == 0)
 641             lex->token = TOKEN_FALSE;
 642         else if(strcmp(saved_text, "null") == 0)
 643             lex->token = TOKEN_NULL;
 644         else
 645             lex->token = TOKEN_INVALID;
 646     }
 647
 648     else {
 649         /* save the rest of the input UTF-8 sequence to get an error
 650            message of valid UTF-8 */
 651         lex_save_cached(lex);
 652         lex->token = TOKEN_INVALID;
 653     }
 654
 655 out:
 656     return lex->token;
 657 }
 658
 659 static char *lex_steal_string(lex_t *lex, size_t *out_len)
 660 {
 661     char *result = NULL;
 662     if(lex->token == TOKEN_STRING) {
 663         result = lex->value.string.val;
 664         *out_len = lex->value.string.len;
 665         lex->value.string.val = NULL;
 666         lex->value.string.len = 0;
 667     }
 668     return result;
 669 }
 670
 671 static int lex_init(lex_t *lex, get_func get, size_t flags, void *data)
 672 {
 673     stream_init(&lex->stream, get, data);
 674     if(strbuffer_init(&lex->saved_text))
 675         return -1;
 676
 677     lex->flags = flags;
 678     lex->token = TOKEN_INVALID;
 679     return 0;
 680 }
 681
 682 static void lex_close(lex_t *lex)
 683 {
 684     if(lex->token == TOKEN_STRING)
 685         lex_free_string(lex);
 686     strbuffer_close(&lex->saved_text);
 687 }
 688
 689
 690 /*** parser ***/
 691
 692 static json_t *parse_value(lex_t *lex, size_t flags, json_error_t *error);
 693
 694 static json_t *parse_object(lex_t *lex, size_t flags, json_error_t *error)
 695 {
 696     json_t *object = json_object();
 697     if(!object)
 698         return NULL;
 699
 700     lex_scan(lex, error);
 701     if(lex->token == '}')
 702         return object;
 703
 704     while(1) {
 705         char *key;
 706         size_t len;
 707         json_t *value;
 708
 709         if(lex->token != TOKEN_STRING) {
 710             error_set(error, lex, json_error_invalid_syntax, "string or '}' expected");
 711             goto error;
 712         }
 713
 714         key = lex_steal_string(lex, &len);
 715         if(!key)
 716             return NULL;
 717         if (memchr(key, '\0', len)) {
 718             jsonp_free(key);
 719             error_set(error, lex, json_error_null_byte_in_key, "NUL byte in object key not supported");
 720             goto error;
 721         }
 722
 723         if(flags & JSON_REJECT_DUPLICATES) {
 724             if(json_object_get(object, key)) {
 725                 jsonp_free(key);
 726                 error_set(error, lex, json_error_duplicate_key, "duplicate object key");
 727                 goto error;
 728             }
 729         }
 730
 731         lex_scan(lex, error);
 732         if(lex->token != ':') {
 733             jsonp_free(key);
 734             error_set(error, lex, json_error_invalid_syntax, "':' expected");
 735             goto error;
 736         }
 737
 738         lex_scan(lex, error);
 739         value = parse_value(lex, flags, error);
 740         if(!value) {
 741             jsonp_free(key);
 742             goto error;
 743         }
 744
 745         if(json_object_set_new_nocheck(object, key, value)) {
 746             jsonp_free(key);
 747             goto error;
 748         }
 749
 750         jsonp_free(key);
 751
 752         lex_scan(lex, error);
 753         if(lex->token != ',')
 754             break;
 755
 756         lex_scan(lex, error);
 757     }
 758
 759     if(lex->token != '}') {
 760         error_set(error, lex, json_error_invalid_syntax, "'}' expected");
 761         goto error;
 762     }
 763
 764     return object;
 765
 766 error:
 767     json_decref(object);
 768     return NULL;
 769 }
 770
 771 static json_t *parse_array(lex_t *lex, size_t flags, json_error_t *error)
 772 {
 773     json_t *array = json_array();
 774     if(!array)
 775         return NULL;
 776
 777     lex_scan(lex, error);
 778     if(lex->token == ']')
 779         return array;
 780
 781     while(lex->token) {
 782         json_t *elem = parse_value(lex, flags, error);
 783         if(!elem)
 784             goto error;
 785
 786         if(json_array_append_new(array, elem)) {
 787             goto error;
 788         }
 789
 790         lex_scan(lex, error);
 791         if(lex->token != ',')
 792             break;
 793
 794         lex_scan(lex, error);
 795     }
 796
 797     if(lex->token != ']') {
 798         error_set(error, lex, json_error_invalid_syntax, "']' expected");
 799         goto error;
 800     }
 801
 802     return array;
 803
 804 error:
 805     json_decref(array);
 806     return NULL;
 807 }
 808
 809 static json_t *parse_value(lex_t *lex, size_t flags, json_error_t *error)
 810 {
 811     json_t *json;
 812
 813     lex->depth++;
 814     if(lex->depth > JSON_PARSER_MAX_DEPTH) {
 815         error_set(error, lex, json_error_stack_overflow, "maximum parsing depth reached");
 816         return NULL;
 817     }
 818
 819     switch(lex->token) {
 820         case TOKEN_STRING: {
 821             const char *value = lex->value.string.val;
 822             size_t len = lex->value.string.len;
 823
 824             if(!(flags & JSON_ALLOW_NUL)) {
 825                 if(memchr(value, '\0', len)) {
 826                     error_set(error, lex, json_error_null_character, "\\u0000 is not allowed without JSON_ALLOW_NUL");
 827                     return NULL;
 828                 }
 829             }
 830
 831             json = jsonp_stringn_nocheck_own(value, len);
 832             if(json) {
 833                 lex->value.string.val = NULL;
 834                 lex->value.string.len = 0;
 835             }
 836             break;
 837         }
 838
 839         case TOKEN_INTEGER: {
 840             json = json_integer(lex->value.integer);
 841             break;
 842         }
 843
 844         case TOKEN_REAL: {
 845             json = json_real(lex->value.real);
 846             break;
 847         }
 848
 849         case TOKEN_TRUE:
 850             json = json_true();
 851             break;
 852
 853         case TOKEN_FALSE:
 854             json = json_false();
 855             break;
 856
 857         case TOKEN_NULL:
 858             json = json_null();
 859             break;
 860
 861         case '{':
 862             json = parse_object(lex, flags, error);
 863             break;
 864
 865         case '[':
 866             json = parse_array(lex, flags, error);
 867             break;
 868
 869         case TOKEN_INVALID:
 870             error_set(error, lex, json_error_invalid_syntax, "invalid token");
 871             return NULL;
 872
 873         default:
 874             error_set(error, lex, json_error_invalid_syntax, "unexpected token");
 875             return NULL;
 876     }
 877
 878     if(!json)
 879         return NULL;
 880
 881     lex->depth--;
 882     return json;
 883 }
 884
 885 static json_t *parse_json(lex_t *lex, size_t flags, json_error_t *error)
 886 {
 887     json_t *result;
 888
 889     lex->depth = 0;
 890
 891     lex_scan(lex, error);
 892     if(!(flags & JSON_DECODE_ANY)) {
 893         if(lex->token != '[' && lex->token != '{') {
 894             error_set(error, lex, json_error_invalid_syntax, "'[' or '{' expected");
 895             return NULL;
 896         }
 897     }
 898
 899     result = parse_value(lex, flags, error);
 900     if(!result)
 901         return NULL;
 902
 903     if(!(flags & JSON_DISABLE_EOF_CHECK)) {
 904         lex_scan(lex, error);
 905         if(lex->token != TOKEN_EOF) {
 906             error_set(error, lex, json_error_end_of_input_expected, "end of file expected");
 907             json_decref(result);
 908             return NULL;
 909         }
 910     }
 911
 912     if(error) {
 913         /* Save the position even though there was no error */
 914         error->position = (int)lex->stream.position;
 915     }
 916
 917     return result;
 918 }
 919
 920 typedef struct
 921 {
 922     const char *data;
 923     size_t pos;
 924 } string_data_t;
 925
 926 static int string_get(void *data)
 927 {
 928     char c;
 929     string_data_t *stream = (string_data_t *)data;
 930     c = stream->data[stream->pos];
 931     if(c == '\0')
 932         return EOF;
 933     else
 934     {
 935         stream->pos++;
 936         return (unsigned char)c;
 937     }
 938 }
 939
 940 json_t *json_loads(const char *string, size_t flags, json_error_t *error)
 941 {
 942     lex_t lex;
 943     json_t *result;
 944     string_data_t stream_data;
 945
 946     jsonp_error_init(error, "<string>");
 947
 948     if (string == NULL) {
 949         error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
 950         return NULL;
 951     }
 952
 953     stream_data.data = string;
 954     stream_data.pos = 0;
 955
 956     if(lex_init(&lex, string_get, flags, (void *)&stream_data))
 957         return NULL;
 958
 959     result = parse_json(&lex, flags, error);
 960
 961     lex_close(&lex);
 962     return result;
 963 }
 964
 965 typedef struct
 966 {
 967     const char *data;
 968     size_t len;
 969     size_t pos;
 970 } buffer_data_t;
 971
 972 static int buffer_get(void *data)
 973 {
 974     char c;
 975     buffer_data_t *stream = data;
 976     if(stream->pos >= stream->len)
 977       return EOF;
 978
 979     c = stream->data[stream->pos];
 980     stream->pos++;
 981     return (unsigned char)c;
 982 }
 983
 984 json_t *json_loadb(const char *buffer, size_t buflen, size_t flags, json_error_t *error)
 985 {
 986     lex_t lex;
 987     json_t *result;
 988     buffer_data_t stream_data;
 989
 990     jsonp_error_init(error, "<buffer>");
 991
 992     if (buffer == NULL) {
 993         error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
 994         return NULL;
 995     }
 996
 997     stream_data.data = buffer;
 998     stream_data.pos = 0;
 999     stream_data.len = buflen;
1000
1001     if(lex_init(&lex, buffer_get, flags, (void *)&stream_data))
1002         return NULL;
1003
1004     result = parse_json(&lex, flags, error);
1005
1006     lex_close(&lex);
1007     return result;
1008 }
1009
1010 json_t *json_loadf(FILE *input, size_t flags, json_error_t *error)
1011 {
1012     lex_t lex;
1013     const char *source;
1014     json_t *result;
1015
1016     if(input == stdin)
1017         source = "<stdin>";
1018     else
1019         source = "<stream>";
1020
1021     jsonp_error_init(error, source);
1022
1023     if (input == NULL) {
1024         error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
1025         return NULL;
1026     }
1027
1028     if(lex_init(&lex, (get_func)fgetc, flags, input))
1029         return NULL;
1030
1031     result = parse_json(&lex, flags, error);
1032
1033     lex_close(&lex);
1034     return result;
1035 }
1036
1037 static int fd_get_func(int *fd)
1038 {
1039     uint8_t c;
1040 #ifdef HAVE_UNISTD_H
1041     if (read(*fd, &c, 1) == 1)
1042         return c;
1043 #endif
1044     return EOF;
1045 }
1046
1047 json_t *json_loadfd(int input, size_t flags, json_error_t *error)
1048 {
1049     lex_t lex;
1050     const char *source;
1051     json_t *result;
1052
1053 #ifdef HAVE_UNISTD_H
1054     if(input == STDIN_FILENO)
1055         source = "<stdin>";
1056     else
1057 #endif
1058         source = "<stream>";
1059
1060     jsonp_error_init(error, source);
1061
1062     if (input < 0) {
1063         error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
1064         return NULL;
1065     }
1066
1067     if(lex_init(&lex, (get_func)fd_get_func, flags, &input))
1068         return NULL;
1069
1070     result = parse_json(&lex, flags, error);
1071
1072     lex_close(&lex);
1073     return result;
1074 }
1075
1076 json_t *json_load_file(const char *path, size_t flags, json_error_t *error)
1077 {
1078     json_t *result;
1079     FILE *fp;
1080
1081     jsonp_error_init(error, path);
1082
1083     if (path == NULL) {
1084         error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
1085         return NULL;
1086     }
1087
1088     fp = fopen(path, "rb");
1089     if(!fp)
1090     {
1091         error_set(error, NULL, json_error_cannot_open_file, "unable to open %s: %s",
1092                   path, strerror(errno));
1093         return NULL;
1094     }
1095
1096     result = json_loadf(fp, flags, error);
1097
1098     fclose(fp);
1099     return result;
1100 }
1101
1102 #define MAX_BUF_LEN 1024
1103
1104 typedef struct
1105 {
1106     char data[MAX_BUF_LEN];
1107     size_t len;
1108     size_t pos;
1109     json_load_callback_t callback;
1110     void *arg;
1111 } callback_data_t;
1112
1113 static int callback_get(void *data)
1114 {
1115     char c;
1116     callback_data_t *stream = data;
1117
1118     if(stream->pos >= stream->len) {
1119         stream->pos = 0;
1120         stream->len = stream->callback(stream->data, MAX_BUF_LEN, stream->arg);
1121         if(stream->len == 0 || stream->len == (size_t)-1)
1122             return EOF;
1123     }
1124
1125     c = stream->data[stream->pos];
1126     stream->pos++;
1127     return (unsigned char)c;
1128 }
1129
1130 json_t *json_load_callback(json_load_callback_t callback, void *arg, size_t flags, json_error_t *error)
1131 {
1132     lex_t lex;
1133     json_t *result;
1134
1135     callback_data_t stream_data;
1136
1137     memset(&stream_data, 0, sizeof(stream_data));
1138     stream_data.callback = callback;
1139     stream_data.arg = arg;
1140
1141     jsonp_error_init(error, "<callback>");
1142
1143     if (callback == NULL) {
1144         error_set(error, NULL, json_error_invalid_argument, "wrong arguments");
1145         return NULL;
1146     }
1147
1148     if(lex_init(&lex, (get_func)callback_get, flags, &stream_data))
1149         return NULL;
1150
1151     result = parse_json(&lex, flags, error);
1152
1153     lex_close(&lex);
1154     return result;
1155 }