Tasmota/lib/default/jsmn-shadinger-1.0/src/jsmn.cpp
Theo Arends 9c5162672b Fix JSMN unescape function
Fix JSMN unescape function (#10107)
2020-12-13 17:31:46 +01:00

458 lines
12 KiB
C++

/*
* MIT License
*
* Copyright (c) 2010 Serge Zaitsev
*
* 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.
*/
#include "jsmn.h"
#define JSMN_STRICT // force strict mode
const uint32_t JSMN_START_MAX = (1U << JSMN_START_B) - 1;
const uint32_t JSMN_LEN_MAX = (1U << JSMN_LEN_B) - 1;
/**
* Allocates a fresh unused token from the token pool.
*/
static jsmntok_t *jsmn_alloc_token(jsmn_parser *parser, jsmntok_t *tokens,
const size_t num_tokens) {
jsmntok_t *tok;
if (parser->toknext >= num_tokens) {
return NULL;
}
tok = &tokens[parser->toknext++];
tok->start = JSMN_START_MAX;
tok->len = JSMN_LEN_MAX;
tok->size = 0;
return tok;
}
/**
* Fills token type and boundaries.
*/
static void jsmn_fill_token(jsmntok_t *token, const jsmntype_t type,
const int start, const int len) {
token->type = type;
token->start = start;
token->len = len;
token->size = 0;
}
/**
* Fills next available token with JSON primitive.
*/
static int jsmn_parse_primitive(jsmn_parser *parser, const char *js,
const size_t len, jsmntok_t *tokens,
const size_t num_tokens) {
jsmntok_t *token;
int start;
start = parser->pos;
for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
switch (js[parser->pos]) {
#ifndef JSMN_STRICT
/* In strict mode primitive must be followed by "," or "}" or "]" */
case ':':
#endif
case '\t':
case '\r':
case '\n':
case ' ':
case ',':
case ']':
case '}':
goto found;
default:
/* to quiet a warning from gcc*/
break;
}
if (js[parser->pos] < 32 || js[parser->pos] >= 127) {
parser->pos = start;
return JSMN_ERROR_INVAL;
}
}
#ifdef JSMN_STRICT
/* In strict mode primitive must be followed by a comma/object/array */
parser->pos = start;
return JSMN_ERROR_PART;
#endif
found:
if (tokens == NULL) {
parser->pos--;
return 0;
}
token = jsmn_alloc_token(parser, tokens, num_tokens);
if (token == NULL) {
parser->pos = start;
return JSMN_ERROR_NOMEM;
}
jsmn_fill_token(token, JSMN_PRIMITIVE, start, parser->pos - start);
parser->pos--;
return 0;
}
/**
* Fills next token with JSON string.
*/
static int jsmn_parse_string(jsmn_parser *parser, const char *js,
const size_t len, jsmntok_t *tokens,
const size_t num_tokens) {
jsmntok_t *token;
int start = parser->pos;
parser->pos++;
/* Skip starting quote */
for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
char c = js[parser->pos];
/* Quote: end of string */
if (c == '\"') {
if (tokens == NULL) {
return 0;
}
token = jsmn_alloc_token(parser, tokens, num_tokens);
if (token == NULL) {
parser->pos = start;
return JSMN_ERROR_NOMEM;
}
jsmn_fill_token(token, JSMN_STRING, start + 1, parser->pos - start - 1);
return 0;
}
/* Backslash: Quoted symbol expected */
if (c == '\\' && parser->pos + 1 < len) {
int i;
parser->pos++;
switch (js[parser->pos]) {
/* Allowed escaped symbols */
case '\"':
case '/':
case '\\':
case 'b':
case 'f':
case 'r':
case 'n':
case 't':
break;
/* Allows escaped symbol \uXXXX */
case 'u':
parser->pos++;
for (i = 0; i < 4 && parser->pos < len && js[parser->pos] != '\0';
i++) {
/* If it isn't a hex character we have an error */
if (!((js[parser->pos] >= 48 && js[parser->pos] <= 57) || /* 0-9 */
(js[parser->pos] >= 65 && js[parser->pos] <= 70) || /* A-F */
(js[parser->pos] >= 97 && js[parser->pos] <= 102))) { /* a-f */
parser->pos = start;
return JSMN_ERROR_INVAL;
}
parser->pos++;
}
parser->pos--;
break;
/* Unexpected symbol */
default:
parser->pos = start;
return JSMN_ERROR_INVAL;
}
}
}
parser->pos = start;
return JSMN_ERROR_PART;
}
/**
* Parse JSON string and fill tokens.
*/
JSMN_API int jsmn_parse(jsmn_parser *parser, const char *js, const size_t len,
jsmntok_t *tokens, const unsigned int num_tokens) {
int r;
int i;
jsmntok_t *token;
int count = parser->toknext;
for (; parser->pos < len && js[parser->pos] != '\0'; parser->pos++) {
char c;
jsmntype_t type;
c = js[parser->pos];
switch (c) {
case '{':
case '[':
count++;
if (tokens == NULL) {
break;
}
token = jsmn_alloc_token(parser, tokens, num_tokens);
if (token == NULL) {
return JSMN_ERROR_NOMEM;
}
if (parser->toksuper != -1) {
jsmntok_t *t = &tokens[parser->toksuper];
#ifdef JSMN_STRICT
/* In strict mode an object or array can't become a key */
if (t->type == JSMN_OBJECT) {
return JSMN_ERROR_INVAL;
}
#endif
t->size++;
}
token->type = (c == '{' ? JSMN_OBJECT : JSMN_ARRAY);
token->start = parser->pos;
parser->toksuper = parser->toknext - 1;
break;
case '}':
case ']':
if (tokens == NULL) {
break;
}
type = (c == '}' ? JSMN_OBJECT : JSMN_ARRAY);
for (i = parser->toknext - 1; i >= 0; i--) {
token = &tokens[i];
if ((token->start != JSMN_START_MAX) && (token->len == JSMN_LEN_MAX)) {
if (token->type != type) {
return JSMN_ERROR_INVAL;
}
parser->toksuper = -1;
token->len = parser->pos + 1 - token->start;
break;
}
}
/* Error if unmatched closing bracket */
if (i == -1) {
return JSMN_ERROR_INVAL;
}
for (; i >= 0; i--) {
token = &tokens[i];
if ((token->start != JSMN_START_MAX) && (token->len == JSMN_LEN_MAX)) {
parser->toksuper = i;
break;
}
}
break;
case '\"':
r = jsmn_parse_string(parser, js, len, tokens, num_tokens);
if (r < 0) {
return r;
}
count++;
if (parser->toksuper != -1 && tokens != NULL) {
tokens[parser->toksuper].size++;
}
break;
case '\t':
case '\r':
case '\n':
case ' ':
break;
case ':':
parser->toksuper = parser->toknext - 1;
break;
case ',':
if (tokens != NULL && parser->toksuper != -1 &&
tokens[parser->toksuper].type != JSMN_ARRAY &&
tokens[parser->toksuper].type != JSMN_OBJECT) {
for (i = parser->toknext - 1; i >= 0; i--) {
if (tokens[i].type == JSMN_ARRAY || tokens[i].type == JSMN_OBJECT) {
if ((tokens[i].start != JSMN_START_MAX) && (tokens[i].len == JSMN_LEN_MAX)) {
parser->toksuper = i;
break;
}
}
}
}
break;
#ifdef JSMN_STRICT
/* In strict mode primitives are: numbers and booleans */
case '-':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
case 't':
case 'f':
case 'n':
// Add uppercase variants
case 'T':
case 'F':
case 'N':
/* And they must not be keys of the object */
if (tokens != NULL && parser->toksuper != -1) {
const jsmntok_t *t = &tokens[parser->toksuper];
if (t->type == JSMN_OBJECT ||
(t->type == JSMN_STRING && t->size != 0)) {
return JSMN_ERROR_INVAL;
}
}
#else
/* In non-strict mode every unquoted value is a primitive */
default:
#endif
r = jsmn_parse_primitive(parser, js, len, tokens, num_tokens);
if (r < 0) {
return r;
}
count++;
if (parser->toksuper != -1 && tokens != NULL) {
tokens[parser->toksuper].size++;
}
break;
#ifdef JSMN_STRICT
/* Unexpected char in strict mode */
default:
return JSMN_ERROR_INVAL;
#endif
}
}
if (tokens != NULL) {
for (i = parser->toknext - 1; i >= 0; i--) {
/* Unmatched opened object or array */
if ((tokens[i].start != JSMN_START_MAX) && (tokens[i].len == JSMN_LEN_MAX)) {
return JSMN_ERROR_PART;
}
}
}
return count;
}
/**
* Creates a new parser based over a given buffer with an array of tokens
* available.
*/
JSMN_API void jsmn_init(jsmn_parser *parser) {
parser->pos = 0;
parser->toknext = 0;
parser->toksuper = -1;
}
//
// Json in-place string unescape
// inpired from https://github.com/mjansson/json/blob/master/json.h
//
//! Define a bitmask with the given number of bits set to 1
#define JSON_BITMASK(numbits) ((1U << (numbits)) - 1)
static uint32_t json_get_num_bytes_as_utf8(uint32_t val) {
if (val >= 0x04000000) return 6;
else if (val >= 0x00200000) return 5;
else if (val >= 0x00010000) return 4;
else if (val >= 0x00000800) return 3;
else if (val >= 0x00000080) return 2;
return 1;
}
static uint32_t json_encode_utf8(char* str, uint32_t val) {
if (val < 0x80) {
*str = (char)val;
return 1;
}
//Get number of _extra_ bytes
uint32_t num = json_get_num_bytes_as_utf8(val) - 1;
*str++ = (char)((0x80U | (JSON_BITMASK(num) << (7U - num))) |
((val >> (6U * num)) & JSON_BITMASK(6U - num)));
for (uint32_t j = 1; j <= num; ++j)
*str++ = (char)(0x80U | ((val >> (6U * (num - j))) & 0x3F));
return num + 1;
}
void json_unescape(char* string) {
size_t outlength = 0;
uint32_t hexval, numbytes;
char c;
for (uint32_t i = 0; (c = string[i]) != 0; i++) {
if ('\\' == c) {
c = string[++i];
switch (c) {
case 0:
string[outlength++] = 0;
return; // end of stream
case '\"':
case '/':
case '\\':
string[outlength++] = c;
break;
case 'b':
string[outlength++] = '\b';
break;
case 'f':
string[outlength++] = '\f';
break;
case 'r':
string[outlength++] = '\r';
break;
case 'n':
string[outlength++] = '\n';
break;
case 't':
string[outlength++] = '\t';
break;
case 'u':
{
uint32_t hexval = 0;
for (uint32_t j = 0; j < 4; ++j) {
char val = string[++i];
if (0 == val) {
string[outlength++] = 0;
return; // we reached end of string
}
uint32_t uival = 0;
if ((val >= 'a') && (val <= 'f'))
uival = 10 + (val - 'a');
else if ((val >= 'A') && (val <= 'F'))
uival = 10 + (val - 'A');
else if ((val >= '0') && (val <= '9'))
uival = val - '0';
hexval |= uival << (3 - j);
}
numbytes = json_get_num_bytes_as_utf8(hexval);
outlength += json_encode_utf8(string + outlength, hexval);
}
break;
default:
break;
}
}
else {
string[outlength++] = c;
}
}
string[outlength++] = 0;
}