/* Lua CJSON - JSON support for Lua * * Copyright (c) 2010-2012 Mark Pulford * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /* Caveats: * - JSON "null" values are represented as lightuserdata since Lua * tables cannot contain "nil". Compare with cjson.null. * - Invalid UTF-8 characters are not detected and will be passed * untouched. If required, UTF-8 error checking should be done * outside this library. * - Javascript comments are not part of the JSON spec, and are not * currently supported. * * Note: Decoding is slower than encoding. Lua spends significant * time (30%) managing tables when parsing JSON since it is * difficult to know object/array sizes ahead of time. */ #include #include #include #include #include #include #include "strbuf.h" #include "fpconv.h" #ifndef CJSON_MODNAME #define CJSON_MODNAME "cjson" #endif #ifndef CJSON_VERSION #define CJSON_VERSION "2.1devel" #endif /* Workaround for Solaris platforms missing isinf() */ #if !defined(isinf) && (defined(USE_INTERNAL_ISINF) || defined(MISSING_ISINF)) #define isinf(x) (!isnan(x) && isnan((x) - (x))) #endif #define DEFAULT_SPARSE_CONVERT 0 #define DEFAULT_SPARSE_RATIO 2 #define DEFAULT_SPARSE_SAFE 10 #define DEFAULT_ENCODE_MAX_DEPTH 1000 #define DEFAULT_DECODE_MAX_DEPTH 1000 #define DEFAULT_ENCODE_INVALID_NUMBERS 0 #define DEFAULT_DECODE_INVALID_NUMBERS 1 #define DEFAULT_ENCODE_KEEP_BUFFER 1 #define DEFAULT_ENCODE_NUMBER_PRECISION 14 #define DEFAULT_ENCODE_EMPTY_TABLE_AS_OBJECT 1 #ifdef DISABLE_INVALID_NUMBERS #undef DEFAULT_DECODE_INVALID_NUMBERS #define DEFAULT_DECODE_INVALID_NUMBERS 0 #endif typedef enum { T_OBJ_BEGIN, T_OBJ_END, T_ARR_BEGIN, T_ARR_END, T_STRING, T_NUMBER, T_BOOLEAN, T_NULL, T_COLON, T_COMMA, T_END, T_WHITESPACE, T_ERROR, T_UNKNOWN } json_token_type_t; static const char *json_token_type_name[] = { "T_OBJ_BEGIN", "T_OBJ_END", "T_ARR_BEGIN", "T_ARR_END", "T_STRING", "T_NUMBER", "T_BOOLEAN", "T_NULL", "T_COLON", "T_COMMA", "T_END", "T_WHITESPACE", "T_ERROR", "T_UNKNOWN", NULL }; typedef struct { json_token_type_t ch2token[256]; char escape2char[256]; /* Decoding */ /* encode_buf is only allocated and used when * encode_keep_buffer is set */ strbuf_t encode_buf; int encode_sparse_convert; int encode_sparse_ratio; int encode_sparse_safe; int encode_max_depth; int encode_invalid_numbers; /* 2 => Encode as "null" */ int encode_number_precision; int encode_keep_buffer; int encode_empty_table_as_object; int decode_invalid_numbers; int decode_max_depth; } json_config_t; typedef struct { const char *data; const char *ptr; strbuf_t *tmp; /* Temporary storage for strings */ json_config_t *cfg; int current_depth; } json_parse_t; typedef struct { json_token_type_t type; int index; union { const char *string; double number; int boolean; } value; int string_len; } json_token_t; static const char *char2escape[256] = { "\\u0000", "\\u0001", "\\u0002", "\\u0003", "\\u0004", "\\u0005", "\\u0006", "\\u0007", "\\b", "\\t", "\\n", "\\u000b", "\\f", "\\r", "\\u000e", "\\u000f", "\\u0010", "\\u0011", "\\u0012", "\\u0013", "\\u0014", "\\u0015", "\\u0016", "\\u0017", "\\u0018", "\\u0019", "\\u001a", "\\u001b", "\\u001c", "\\u001d", "\\u001e", "\\u001f", NULL, NULL, "\\\"", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "\\/", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "\\\\", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "\\u007f", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, }; /* ===== CONFIGURATION ===== */ static json_config_t *json_fetch_config(lua_State *l) { json_config_t *cfg; cfg = lua_touserdata(l, lua_upvalueindex(1)); if (!cfg) luaL_error(l, "BUG: Unable to fetch CJSON configuration"); return cfg; } /* Ensure the correct number of arguments have been provided. * Pad with nil to allow other functions to simply check arg[i] * to find whether an argument was provided */ static json_config_t *json_arg_init(lua_State *l, int args) { luaL_argcheck(l, lua_gettop(l) <= args, args + 1, "found too many arguments"); while (lua_gettop(l) < args) lua_pushnil(l); return json_fetch_config(l); } /* Process integer options for configuration functions */ static int json_integer_option(lua_State *l, int optindex, int *setting, int min, int max) { char errmsg[64]; int value; if (!lua_isnil(l, optindex)) { value = luaL_checkinteger(l, optindex); snprintf(errmsg, sizeof(errmsg), "expected integer between %d and %d", min, max); luaL_argcheck(l, min <= value && value <= max, 1, errmsg); *setting = value; } lua_pushinteger(l, *setting); return 1; } /* Process enumerated arguments for a configuration function */ static int json_enum_option(lua_State *l, int optindex, int *setting, const char **options, int bool_true) { static const char *bool_options[] = { "off", "on", NULL }; if (!options) { options = bool_options; bool_true = 1; } if (!lua_isnil(l, optindex)) { if (bool_true && lua_isboolean(l, optindex)) *setting = lua_toboolean(l, optindex) * bool_true; else *setting = luaL_checkoption(l, optindex, NULL, options); } if (bool_true && (*setting == 0 || *setting == bool_true)) lua_pushboolean(l, *setting); else lua_pushstring(l, options[*setting]); return 1; } /* Configures handling of extremely sparse arrays: * convert: Convert extremely sparse arrays into objects? Otherwise error. * ratio: 0: always allow sparse; 1: never allow sparse; >1: use ratio * safe: Always use an array when the max index <= safe */ static int json_cfg_encode_sparse_array(lua_State *l) { json_config_t *cfg = json_arg_init(l, 3); json_enum_option(l, 1, &cfg->encode_sparse_convert, NULL, 1); json_integer_option(l, 2, &cfg->encode_sparse_ratio, 0, INT_MAX); json_integer_option(l, 3, &cfg->encode_sparse_safe, 0, INT_MAX); return 3; } /* Configures the maximum number of nested arrays/objects allowed when * encoding */ static int json_cfg_encode_max_depth(lua_State *l) { json_config_t *cfg = json_arg_init(l, 1); return json_integer_option(l, 1, &cfg->encode_max_depth, 1, INT_MAX); } /* Configures the maximum number of nested arrays/objects allowed when * encoding */ static int json_cfg_decode_max_depth(lua_State *l) { json_config_t *cfg = json_arg_init(l, 1); return json_integer_option(l, 1, &cfg->decode_max_depth, 1, INT_MAX); } /* Configures number precision when converting doubles to text */ static int json_cfg_encode_number_precision(lua_State *l) { json_config_t *cfg = json_arg_init(l, 1); return json_integer_option(l, 1, &cfg->encode_number_precision, 1, 14); } /* Configures how to treat empty table when encode lua table */ static int json_cfg_encode_empty_table_as_object(lua_State *l) { json_config_t *cfg = json_arg_init(l, 1); return json_enum_option(l, 1, &cfg->encode_empty_table_as_object, NULL, 1); } /* Configures JSON encoding buffer persistence */ static int json_cfg_encode_keep_buffer(lua_State *l) { json_config_t *cfg = json_arg_init(l, 1); int old_value; old_value = cfg->encode_keep_buffer; json_enum_option(l, 1, &cfg->encode_keep_buffer, NULL, 1); /* Init / free the buffer if the setting has changed */ if (old_value ^ cfg->encode_keep_buffer) { if (cfg->encode_keep_buffer) strbuf_init(&cfg->encode_buf, 0); else strbuf_free(&cfg->encode_buf); } return 1; } #if defined(DISABLE_INVALID_NUMBERS) && !defined(USE_INTERNAL_FPCONV) void json_verify_invalid_number_setting(lua_State *l, int *setting) { if (*setting == 1) { *setting = 0; luaL_error(l, "Infinity, NaN, and/or hexadecimal numbers are not supported."); } } #else #define json_verify_invalid_number_setting(l, s) do { } while(0) #endif static int json_cfg_encode_invalid_numbers(lua_State *l) { static const char *options[] = { "off", "on", "null", NULL }; json_config_t *cfg = json_arg_init(l, 1); json_enum_option(l, 1, &cfg->encode_invalid_numbers, options, 1); json_verify_invalid_number_setting(l, &cfg->encode_invalid_numbers); return 1; } static int json_cfg_decode_invalid_numbers(lua_State *l) { json_config_t *cfg = json_arg_init(l, 1); json_enum_option(l, 1, &cfg->decode_invalid_numbers, NULL, 1); json_verify_invalid_number_setting(l, &cfg->encode_invalid_numbers); return 1; } static int json_destroy_config(lua_State *l) { json_config_t *cfg; cfg = lua_touserdata(l, 1); if (cfg) strbuf_free(&cfg->encode_buf); cfg = NULL; return 0; } static void json_create_config(lua_State *l) { json_config_t *cfg; int i; cfg = lua_newuserdata(l, sizeof(*cfg)); /* Create GC method to clean up strbuf */ lua_newtable(l); lua_pushcfunction(l, json_destroy_config); lua_setfield(l, -2, "__gc"); lua_setmetatable(l, -2); cfg->encode_sparse_convert = DEFAULT_SPARSE_CONVERT; cfg->encode_sparse_ratio = DEFAULT_SPARSE_RATIO; cfg->encode_sparse_safe = DEFAULT_SPARSE_SAFE; cfg->encode_max_depth = DEFAULT_ENCODE_MAX_DEPTH; cfg->decode_max_depth = DEFAULT_DECODE_MAX_DEPTH; cfg->encode_invalid_numbers = DEFAULT_ENCODE_INVALID_NUMBERS; cfg->decode_invalid_numbers = DEFAULT_DECODE_INVALID_NUMBERS; cfg->encode_keep_buffer = DEFAULT_ENCODE_KEEP_BUFFER; cfg->encode_number_precision = DEFAULT_ENCODE_NUMBER_PRECISION; cfg->encode_empty_table_as_object = DEFAULT_ENCODE_EMPTY_TABLE_AS_OBJECT; #if DEFAULT_ENCODE_KEEP_BUFFER > 0 strbuf_init(&cfg->encode_buf, 0); #endif /* Decoding init */ /* Tag all characters as an error */ for (i = 0; i < 256; i++) cfg->ch2token[i] = T_ERROR; /* Set tokens that require no further processing */ cfg->ch2token['{'] = T_OBJ_BEGIN; cfg->ch2token['}'] = T_OBJ_END; cfg->ch2token['['] = T_ARR_BEGIN; cfg->ch2token[']'] = T_ARR_END; cfg->ch2token[','] = T_COMMA; cfg->ch2token[':'] = T_COLON; cfg->ch2token['\0'] = T_END; cfg->ch2token[' '] = T_WHITESPACE; cfg->ch2token['\t'] = T_WHITESPACE; cfg->ch2token['\n'] = T_WHITESPACE; cfg->ch2token['\r'] = T_WHITESPACE; /* Update characters that require further processing */ cfg->ch2token['f'] = T_UNKNOWN; /* false? */ cfg->ch2token['i'] = T_UNKNOWN; /* inf, ininity? */ cfg->ch2token['I'] = T_UNKNOWN; cfg->ch2token['n'] = T_UNKNOWN; /* null, nan? */ cfg->ch2token['N'] = T_UNKNOWN; cfg->ch2token['t'] = T_UNKNOWN; /* true? */ cfg->ch2token['"'] = T_UNKNOWN; /* string? */ cfg->ch2token['+'] = T_UNKNOWN; /* number? */ cfg->ch2token['-'] = T_UNKNOWN; for (i = 0; i < 10; i++) cfg->ch2token['0' + i] = T_UNKNOWN; /* Lookup table for parsing escape characters */ for (i = 0; i < 256; i++) cfg->escape2char[i] = 0; /* String error */ cfg->escape2char['"'] = '"'; cfg->escape2char['\\'] = '\\'; cfg->escape2char['/'] = '/'; cfg->escape2char['b'] = '\b'; cfg->escape2char['t'] = '\t'; cfg->escape2char['n'] = '\n'; cfg->escape2char['f'] = '\f'; cfg->escape2char['r'] = '\r'; cfg->escape2char['u'] = 'u'; /* Unicode parsing required */ } /* ===== ENCODING ===== */ static void json_encode_exception(lua_State *l, json_config_t *cfg, strbuf_t *json, int lindex, const char *reason) { if (!cfg->encode_keep_buffer) strbuf_free(json); luaL_error(l, "Cannot serialise %s: %s", lua_typename(l, lua_type(l, lindex)), reason); } /* json_append_string args: * - lua_State * - JSON strbuf * - String (Lua stack index) * * Returns nothing. Doesn't remove string from Lua stack */ static void json_append_string(lua_State *l, strbuf_t *json, int lindex) { const char *escstr; int i; const char *str; size_t len; str = lua_tolstring(l, lindex, &len); /* Worst case is len * 6 (all unicode escapes). * This buffer is reused constantly for small strings * If there are any excess pages, they won't be hit anyway. * This gains ~5% speedup. */ strbuf_ensure_empty_length(json, len * 6 + 2); strbuf_append_char_unsafe(json, '\"'); for (i = 0; i < len; i++) { escstr = char2escape[(unsigned char)str[i]]; if (escstr) strbuf_append_string(json, escstr); else strbuf_append_char_unsafe(json, str[i]); } strbuf_append_char_unsafe(json, '\"'); } /* Find the size of the array on the top of the Lua stack * -1 object (not a pure array) * >=0 elements in array */ static int lua_array_length(lua_State *l, json_config_t *cfg, strbuf_t *json) { double k; int max; int items; max = 0; items = 0; lua_pushnil(l); /* table, startkey */ while (lua_next(l, -2) != 0) { /* table, key, value */ if (lua_type(l, -2) == LUA_TNUMBER && (k = lua_tonumber(l, -2))) { /* Integer >= 1 ? */ if (floor(k) == k && k >= 1) { if (k > max) max = k; items++; lua_pop(l, 1); continue; } } /* Must not be an array (non integer key) */ lua_pop(l, 2); return -1; } /* Encode excessively sparse arrays as objects (if enabled) */ if (cfg->encode_sparse_ratio > 0 && max > items * cfg->encode_sparse_ratio && max > cfg->encode_sparse_safe) { if (!cfg->encode_sparse_convert) json_encode_exception(l, cfg, json, -1, "excessively sparse array"); return -1; } return max; } static void json_check_encode_depth(lua_State *l, json_config_t *cfg, int current_depth, strbuf_t *json) { /* Ensure there are enough slots free to traverse a table (key, * value) and push a string for a potential error message. * * Unlike "decode", the key and value are still on the stack when * lua_checkstack() is called. Hence an extra slot for luaL_error() * below is required just in case the next check to lua_checkstack() * fails. * * While this won't cause a crash due to the EXTRA_STACK reserve * slots, it would still be an improper use of the API. */ if (current_depth <= cfg->encode_max_depth && lua_checkstack(l, 3)) return; if (!cfg->encode_keep_buffer) strbuf_free(json); luaL_error(l, "Cannot serialise, excessive nesting (%d)", current_depth); } static void json_append_data(lua_State *l, json_config_t *cfg, int current_depth, strbuf_t *json); /* json_append_array args: * - lua_State * - JSON strbuf * - Size of passwd Lua array (top of stack) */ static void json_append_array(lua_State *l, json_config_t *cfg, int current_depth, strbuf_t *json, int array_length) { int comma, i; strbuf_append_char(json, '['); comma = 0; for (i = 1; i <= array_length; i++) { if (comma) strbuf_append_char(json, ','); else comma = 1; lua_rawgeti(l, -1, i); json_append_data(l, cfg, current_depth, json); lua_pop(l, 1); } strbuf_append_char(json, ']'); } static void json_append_number(lua_State *l, json_config_t *cfg, strbuf_t *json, int lindex) { double num = lua_tonumber(l, lindex); int len; if (cfg->encode_invalid_numbers == 0) { /* Prevent encoding invalid numbers */ if (isinf(num) || isnan(num)) json_encode_exception(l, cfg, json, lindex, "must not be NaN or Infinity"); } else if (cfg->encode_invalid_numbers == 1) { /* Encode NaN/Infinity separately to ensure Javascript compatible * values are used. */ if (isnan(num)) { strbuf_append_mem(json, "NaN", 3); return; } if (isinf(num)) { if (num < 0) strbuf_append_mem(json, "-Infinity", 9); else strbuf_append_mem(json, "Infinity", 8); return; } } else { /* Encode invalid numbers as "null" */ if (isinf(num) || isnan(num)) { strbuf_append_mem(json, "null", 4); return; } } strbuf_ensure_empty_length(json, FPCONV_G_FMT_BUFSIZE); len = fpconv_g_fmt(strbuf_empty_ptr(json), num, cfg->encode_number_precision); strbuf_extend_length(json, len); } static void json_append_object(lua_State *l, json_config_t *cfg, int current_depth, strbuf_t *json) { int comma, keytype; /* Object */ strbuf_append_char(json, '{'); lua_pushnil(l); /* table, startkey */ comma = 0; while (lua_next(l, -2) != 0) { if (comma) strbuf_append_char(json, ','); else comma = 1; /* table, key, value */ keytype = lua_type(l, -2); if (keytype == LUA_TNUMBER) { strbuf_append_char(json, '"'); json_append_number(l, cfg, json, -2); strbuf_append_mem(json, "\":", 2); } else if (keytype == LUA_TSTRING) { json_append_string(l, json, -2); strbuf_append_char(json, ':'); } else { json_encode_exception(l, cfg, json, -2, "table key must be a number or string"); /* never returns */ } /* table, key, value */ json_append_data(l, cfg, current_depth, json); lua_pop(l, 1); /* table, key */ } strbuf_append_char(json, '}'); } /* Serialise Lua data into JSON string. */ static void json_append_data(lua_State *l, json_config_t *cfg, int current_depth, strbuf_t *json) { int len; switch (lua_type(l, -1)) { case LUA_TSTRING: json_append_string(l, json, -1); break; case LUA_TNUMBER: json_append_number(l, cfg, json, -1); break; case LUA_TBOOLEAN: if (lua_toboolean(l, -1)) strbuf_append_mem(json, "true", 4); else strbuf_append_mem(json, "false", 5); break; case LUA_TTABLE: current_depth++; json_check_encode_depth(l, cfg, current_depth, json); len = lua_array_length(l, cfg, json); if (len > 0 || (len == 0 && !cfg->encode_empty_table_as_object)) json_append_array(l, cfg, current_depth, json, len); else json_append_object(l, cfg, current_depth, json); break; case LUA_TNIL: strbuf_append_mem(json, "null", 4); break; case LUA_TLIGHTUSERDATA: if (lua_touserdata(l, -1) == NULL) { strbuf_append_mem(json, "null", 4); break; } default: /* Remaining types (LUA_TFUNCTION, LUA_TUSERDATA, LUA_TTHREAD, * and LUA_TLIGHTUSERDATA) cannot be serialised */ json_encode_exception(l, cfg, json, -1, "type not supported"); /* never returns */ } } static int json_encode(lua_State *l) { json_config_t *cfg = json_fetch_config(l); strbuf_t local_encode_buf; strbuf_t *encode_buf; char *json; int len; luaL_argcheck(l, lua_gettop(l) == 1, 1, "expected 1 argument"); if (!cfg->encode_keep_buffer) { /* Use private buffer */ encode_buf = &local_encode_buf; strbuf_init(encode_buf, 0); } else { /* Reuse existing buffer */ encode_buf = &cfg->encode_buf; strbuf_reset(encode_buf); } json_append_data(l, cfg, 0, encode_buf); json = strbuf_string(encode_buf, &len); lua_pushlstring(l, json, len); if (!cfg->encode_keep_buffer) strbuf_free(encode_buf); return 1; } /* ===== DECODING ===== */ static void json_process_value(lua_State *l, json_parse_t *json, json_token_t *token); static int hexdigit2int(char hex) { if ('0' <= hex && hex <= '9') return hex - '0'; /* Force lowercase */ hex |= 0x20; if ('a' <= hex && hex <= 'f') return 10 + hex - 'a'; return -1; } static int decode_hex4(const char *hex) { int digit[4]; int i; /* Convert ASCII hex digit to numeric digit * Note: this returns an error for invalid hex digits, including * NULL */ for (i = 0; i < 4; i++) { digit[i] = hexdigit2int(hex[i]); if (digit[i] < 0) { return -1; } } return (digit[0] << 12) + (digit[1] << 8) + (digit[2] << 4) + digit[3]; } /* Converts a Unicode codepoint to UTF-8. * Returns UTF-8 string length, and up to 4 bytes in *utf8 */ static int codepoint_to_utf8(char *utf8, int codepoint) { /* 0xxxxxxx */ if (codepoint <= 0x7F) { utf8[0] = codepoint; return 1; } /* 110xxxxx 10xxxxxx */ if (codepoint <= 0x7FF) { utf8[0] = (codepoint >> 6) | 0xC0; utf8[1] = (codepoint & 0x3F) | 0x80; return 2; } /* 1110xxxx 10xxxxxx 10xxxxxx */ if (codepoint <= 0xFFFF) { utf8[0] = (codepoint >> 12) | 0xE0; utf8[1] = ((codepoint >> 6) & 0x3F) | 0x80; utf8[2] = (codepoint & 0x3F) | 0x80; return 3; } /* 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */ if (codepoint <= 0x1FFFFF) { utf8[0] = (codepoint >> 18) | 0xF0; utf8[1] = ((codepoint >> 12) & 0x3F) | 0x80; utf8[2] = ((codepoint >> 6) & 0x3F) | 0x80; utf8[3] = (codepoint & 0x3F) | 0x80; return 4; } return 0; } /* Called when index pointing to beginning of UTF-16 code escape: \uXXXX * \u is guaranteed to exist, but the remaining hex characters may be * missing. * Translate to UTF-8 and append to temporary token string. * Must advance index to the next character to be processed. * Returns: 0 success * -1 error */ static int json_append_unicode_escape(json_parse_t *json) { char utf8[4]; /* Surrogate pairs require 4 UTF-8 bytes */ int codepoint; int surrogate_low; int len; int escape_len = 6; /* Fetch UTF-16 code unit */ codepoint = decode_hex4(json->ptr + 2); if (codepoint < 0) return -1; /* UTF-16 surrogate pairs take the following 2 byte form: * 11011 x yyyyyyyyyy * When x = 0: y is the high 10 bits of the codepoint * x = 1: y is the low 10 bits of the codepoint * * Check for a surrogate pair (high or low) */ if ((codepoint & 0xF800) == 0xD800) { /* Error if the 1st surrogate is not high */ if (codepoint & 0x400) return -1; /* Ensure the next code is a unicode escape */ if (*(json->ptr + escape_len) != '\\' || *(json->ptr + escape_len + 1) != 'u') { return -1; } /* Fetch the next codepoint */ surrogate_low = decode_hex4(json->ptr + 2 + escape_len); if (surrogate_low < 0) return -1; /* Error if the 2nd code is not a low surrogate */ if ((surrogate_low & 0xFC00) != 0xDC00) return -1; /* Calculate Unicode codepoint */ codepoint = (codepoint & 0x3FF) << 10; surrogate_low &= 0x3FF; codepoint = (codepoint | surrogate_low) + 0x10000; escape_len = 12; } /* Convert codepoint to UTF-8 */ len = codepoint_to_utf8(utf8, codepoint); if (!len) return -1; /* Append bytes and advance parse index */ strbuf_append_mem_unsafe(json->tmp, utf8, len); json->ptr += escape_len; return 0; } static void json_set_token_error(json_token_t *token, json_parse_t *json, const char *errtype) { token->type = T_ERROR; token->index = json->ptr - json->data; token->value.string = errtype; } static void json_next_string_token(json_parse_t *json, json_token_t *token) { char *escape2char = json->cfg->escape2char; char ch; /* Caller must ensure a string is next */ assert(*json->ptr == '"'); /* Skip " */ json->ptr++; /* json->tmp is the temporary strbuf used to accumulate the * decoded string value. * json->tmp is sized to handle JSON containing only a string value. */ strbuf_reset(json->tmp); while ((ch = *json->ptr) != '"') { if (!ch) { /* Premature end of the string */ json_set_token_error(token, json, "unexpected end of string"); return; } /* Handle escapes */ if (ch == '\\') { /* Fetch escape character */ ch = *(json->ptr + 1); /* Translate escape code and append to tmp string */ ch = escape2char[(unsigned char)ch]; if (ch == 'u') { if (json_append_unicode_escape(json) == 0) continue; json_set_token_error(token, json, "invalid unicode escape code"); return; } if (!ch) { json_set_token_error(token, json, "invalid escape code"); return; } /* Skip '\' */ json->ptr++; } /* Append normal character or translated single character * Unicode escapes are handled above */ strbuf_append_char_unsafe(json->tmp, ch); json->ptr++; } json->ptr++; /* Eat final quote (") */ strbuf_ensure_null(json->tmp); token->type = T_STRING; token->value.string = strbuf_string(json->tmp, &token->string_len); } /* JSON numbers should take the following form: * -?(0|[1-9]|[1-9][0-9]+)(.[0-9]+)?([eE][-+]?[0-9]+)? * * json_next_number_token() uses strtod() which allows other forms: * - numbers starting with '+' * - NaN, -NaN, infinity, -infinity * - hexadecimal numbers * - numbers with leading zeros * * json_is_invalid_number() detects "numbers" which may pass strtod()'s * error checking, but should not be allowed with strict JSON. * * json_is_invalid_number() may pass numbers which cause strtod() * to generate an error. */ static int json_is_invalid_number(json_parse_t *json) { const char *p = json->ptr; /* Reject numbers starting with + */ if (*p == '+') return 1; /* Skip minus sign if it exists */ if (*p == '-') p++; /* Reject numbers starting with 0x, or leading zeros */ if (*p == '0') { int ch2 = *(p + 1); if ((ch2 | 0x20) == 'x' || /* Hex */ ('0' <= ch2 && ch2 <= '9')) /* Leading zero */ return 1; return 0; } else if (*p <= '9') { return 0; /* Ordinary number */ } /* Reject inf/nan */ if (!strncasecmp(p, "inf", 3)) return 1; if (!strncasecmp(p, "nan", 3)) return 1; /* Pass all other numbers which may still be invalid, but * strtod() will catch them. */ return 0; } static void json_next_number_token(json_parse_t *json, json_token_t *token) { char *endptr; token->type = T_NUMBER; token->value.number = fpconv_strtod(json->ptr, &endptr); if (json->ptr == endptr) json_set_token_error(token, json, "invalid number"); else json->ptr = endptr; /* Skip the processed number */ return; } /* Fills in the token struct. * T_STRING will return a pointer to the json_parse_t temporary string * T_ERROR will leave the json->ptr pointer at the error. */ static void json_next_token(json_parse_t *json, json_token_t *token) { const json_token_type_t *ch2token = json->cfg->ch2token; int ch; /* Eat whitespace. */ while (1) { ch = (unsigned char)*(json->ptr); token->type = ch2token[ch]; if (token->type != T_WHITESPACE) break; json->ptr++; } /* Store location of new token. Required when throwing errors * for unexpected tokens (syntax errors). */ token->index = json->ptr - json->data; /* Don't advance the pointer for an error or the end */ if (token->type == T_ERROR) { json_set_token_error(token, json, "invalid token"); return; } if (token->type == T_END) { return; } /* Found a known single character token, advance index and return */ if (token->type != T_UNKNOWN) { json->ptr++; return; } /* Process characters which triggered T_UNKNOWN * * Must use strncmp() to match the front of the JSON string. * JSON identifier must be lowercase. * When strict_numbers if disabled, either case is allowed for * Infinity/NaN (since we are no longer following the spec..) */ if (ch == '"') { json_next_string_token(json, token); return; } else if (ch == '-' || ('0' <= ch && ch <= '9')) { if (!json->cfg->decode_invalid_numbers && json_is_invalid_number(json)) { json_set_token_error(token, json, "invalid number"); return; } json_next_number_token(json, token); return; } else if (!strncmp(json->ptr, "true", 4)) { token->type = T_BOOLEAN; token->value.boolean = 1; json->ptr += 4; return; } else if (!strncmp(json->ptr, "false", 5)) { token->type = T_BOOLEAN; token->value.boolean = 0; json->ptr += 5; return; } else if (!strncmp(json->ptr, "null", 4)) { token->type = T_NULL; json->ptr += 4; return; } else if (json->cfg->decode_invalid_numbers && json_is_invalid_number(json)) { /* When decode_invalid_numbers is enabled, only attempt to process * numbers we know are invalid JSON (Inf, NaN, hex) * This is required to generate an appropriate token error, * otherwise all bad tokens will register as "invalid number" */ json_next_number_token(json, token); return; } /* Token starts with t/f/n but isn't recognised above. */ json_set_token_error(token, json, "invalid token"); } /* This function does not return. * DO NOT CALL WITH DYNAMIC MEMORY ALLOCATED. * The only supported exception is the temporary parser string * json->tmp struct. * json and token should exist on the stack somewhere. * luaL_error() will long_jmp and release the stack */ static void json_throw_parse_error(lua_State *l, json_parse_t *json, const char *exp, json_token_t *token) { const char *found; strbuf_free(json->tmp); if (token->type == T_ERROR) found = token->value.string; else found = json_token_type_name[token->type]; /* Note: token->index is 0 based, display starting from 1 */ luaL_error(l, "Expected %s but found %s at character %d", exp, found, token->index + 1); } static inline void json_decode_ascend(json_parse_t *json) { json->current_depth--; } static void json_decode_descend(lua_State *l, json_parse_t *json, int slots) { json->current_depth++; if (json->current_depth <= json->cfg->decode_max_depth && lua_checkstack(l, slots)) { return; } strbuf_free(json->tmp); luaL_error(l, "Found too many nested data structures (%d) at character %d", json->current_depth, json->ptr - json->data); } static void json_parse_object_context(lua_State *l, json_parse_t *json) { json_token_t token; /* 3 slots required: * .., table, key, value */ json_decode_descend(l, json, 3); lua_newtable(l); json_next_token(json, &token); /* Handle empty objects */ if (token.type == T_OBJ_END) { json_decode_ascend(json); return; } while (1) { if (token.type != T_STRING) json_throw_parse_error(l, json, "object key string", &token); /* Push key */ lua_pushlstring(l, token.value.string, token.string_len); json_next_token(json, &token); if (token.type != T_COLON) json_throw_parse_error(l, json, "colon", &token); /* Fetch value */ json_next_token(json, &token); json_process_value(l, json, &token); /* Set key = value */ lua_rawset(l, -3); json_next_token(json, &token); if (token.type == T_OBJ_END) { json_decode_ascend(json); return; } if (token.type != T_COMMA) json_throw_parse_error(l, json, "comma or object end", &token); json_next_token(json, &token); } } /* Handle the array context */ static void json_parse_array_context(lua_State *l, json_parse_t *json) { json_token_t token; int i; /* 2 slots required: * .., table, value */ json_decode_descend(l, json, 2); lua_newtable(l); json_next_token(json, &token); /* Handle empty arrays */ if (token.type == T_ARR_END) { json_decode_ascend(json); return; } for (i = 1; ; i++) { json_process_value(l, json, &token); lua_rawseti(l, -2, i); /* arr[i] = value */ json_next_token(json, &token); if (token.type == T_ARR_END) { json_decode_ascend(json); return; } if (token.type != T_COMMA) json_throw_parse_error(l, json, "comma or array end", &token); json_next_token(json, &token); } } /* Handle the "value" context */ static void json_process_value(lua_State *l, json_parse_t *json, json_token_t *token) { switch (token->type) { case T_STRING: lua_pushlstring(l, token->value.string, token->string_len); break;; case T_NUMBER: lua_pushnumber(l, token->value.number); break;; case T_BOOLEAN: lua_pushboolean(l, token->value.boolean); break;; case T_OBJ_BEGIN: json_parse_object_context(l, json); break;; case T_ARR_BEGIN: json_parse_array_context(l, json); break;; case T_NULL: /* In Lua, setting "t[k] = nil" will delete k from the table. * Hence a NULL pointer lightuserdata object is used instead */ lua_pushlightuserdata(l, NULL); break;; default: json_throw_parse_error(l, json, "value", token); } } static int json_decode(lua_State *l) { json_parse_t json; json_token_t token; size_t json_len; luaL_argcheck(l, lua_gettop(l) == 1, 1, "expected 1 argument"); json.cfg = json_fetch_config(l); json.data = luaL_checklstring(l, 1, &json_len); json.current_depth = 0; json.ptr = json.data; /* Detect Unicode other than UTF-8 (see RFC 4627, Sec 3) * * CJSON can support any simple data type, hence only the first * character is guaranteed to be ASCII (at worst: '"'). This is * still enough to detect whether the wrong encoding is in use. */ if (json_len >= 2 && (!json.data[0] || !json.data[1])) luaL_error(l, "JSON parser does not support UTF-16 or UTF-32"); /* Ensure the temporary buffer can hold the entire string. * This means we no longer need to do length checks since the decoded * string must be smaller than the entire json string */ json.tmp = strbuf_new(json_len); json_next_token(&json, &token); json_process_value(l, &json, &token); /* Ensure there is no more input left */ json_next_token(&json, &token); if (token.type != T_END) json_throw_parse_error(l, &json, "the end", &token); strbuf_free(json.tmp); return 1; } /* ===== INITIALISATION ===== */ #if !defined(LUA_VERSION_NUM) || LUA_VERSION_NUM < 502 /* Compatibility for Lua 5.1. * * luaL_setfuncs() is used to create a module table where the functions have * json_config_t as their first upvalue. Code borrowed from Lua 5.2 source. */ static void luaL_setfuncs (lua_State *l, const luaL_Reg *reg, int nup) { int i; luaL_checkstack(l, nup, "too many upvalues"); for (; reg->name != NULL; reg++) { /* fill the table with given functions */ for (i = 0; i < nup; i++) /* copy upvalues to the top */ lua_pushvalue(l, -nup); lua_pushcclosure(l, reg->func, nup); /* closure with those upvalues */ lua_setfield(l, -(nup + 2), reg->name); } lua_pop(l, nup); /* remove upvalues */ } #endif /* Call target function in protected mode with all supplied args. * Assumes target function only returns a single non-nil value. * Convert and return thrown errors as: nil, "error message" */ static int json_protect_conversion(lua_State *l) { int err; /* Deliberately throw an error for invalid arguments */ luaL_argcheck(l, lua_gettop(l) == 1, 1, "expected 1 argument"); /* pcall() the function stored as upvalue(1) */ lua_pushvalue(l, lua_upvalueindex(1)); lua_insert(l, 1); err = lua_pcall(l, 1, 1, 0); if (!err) return 1; if (err == LUA_ERRRUN) { lua_pushnil(l); lua_insert(l, -2); return 2; } /* Since we are not using a custom error handler, the only remaining * errors are memory related */ return luaL_error(l, "Memory allocation error in CJSON protected call"); } /* Return cjson module table */ static int lua_cjson_new(lua_State *l) { luaL_Reg reg[] = { { "encode", json_encode }, { "decode", json_decode }, { "encode_empty_table_as_object", json_cfg_encode_empty_table_as_object }, { "encode_sparse_array", json_cfg_encode_sparse_array }, { "encode_max_depth", json_cfg_encode_max_depth }, { "decode_max_depth", json_cfg_decode_max_depth }, { "encode_number_precision", json_cfg_encode_number_precision }, { "encode_keep_buffer", json_cfg_encode_keep_buffer }, { "encode_invalid_numbers", json_cfg_encode_invalid_numbers }, { "decode_invalid_numbers", json_cfg_decode_invalid_numbers }, { "new", lua_cjson_new }, { NULL, NULL } }; /* Initialise number conversions */ fpconv_init(); /* cjson module table */ lua_newtable(l); /* Register functions with config data as upvalue */ json_create_config(l); luaL_setfuncs(l, reg, 1); /* Set cjson.null */ lua_pushlightuserdata(l, NULL); lua_setfield(l, -2, "null"); /* Set module name / version fields */ lua_pushliteral(l, CJSON_MODNAME); lua_setfield(l, -2, "_NAME"); lua_pushliteral(l, CJSON_VERSION); lua_setfield(l, -2, "_VERSION"); return 1; } /* Return cjson.safe module table */ static int lua_cjson_safe_new(lua_State *l) { const char *func[] = { "decode", "encode", NULL }; int i; lua_cjson_new(l); /* Fix new() method */ lua_pushcfunction(l, lua_cjson_safe_new); lua_setfield(l, -2, "new"); for (i = 0; func[i]; i++) { lua_getfield(l, -1, func[i]); lua_pushcclosure(l, json_protect_conversion, 1); lua_setfield(l, -2, func[i]); } return 1; } int luaopen_cjson(lua_State *l) { lua_cjson_new(l); #ifdef ENABLE_CJSON_GLOBAL /* Register a global "cjson" table. */ lua_pushvalue(l, -1); lua_setglobal(l, CJSON_MODNAME); #endif /* Return cjson table */ return 1; } int luaopen_cjson_safe(lua_State *l) { lua_cjson_safe_new(l); /* Return cjson.safe table */ return 1; } /* vi:ai et sw=4 ts=4: */