blob: 7b23f3037f1b9811cc349eed8802bf6c82d3be13 [file] [log] [blame]
/**
* @file json.c
* @author Radek Krejci <rkrejci@cesnet.cz>
* @brief Generic JSON format parser for libyang
*
* Copyright (c) 2020 CESNET, z.s.p.o.
*
* This source code is licensed under BSD 3-Clause License (the "License").
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://opensource.org/licenses/BSD-3-Clause
*/
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include "common.h"
#include "in_internal.h"
#include "json.h"
#define JSON_PUSH_STATUS_RET(CTX, STATUS) \
LY_CHECK_RET(ly_set_add(&CTX->status, (void*)STATUS, 1, NULL))
#define JSON_POP_STATUS_RET(CTX) \
assert(CTX->status.count); CTX->status.count--;
const char *
lyjson_token2str(enum LYJSON_PARSER_STATUS status)
{
switch (status) {
case LYJSON_ERROR:
return "error";
case LYJSON_ROOT:
return "document root";
case LYJSON_FALSE:
return "false";
case LYJSON_TRUE:
return "true";
case LYJSON_NULL:
return "null";
case LYJSON_OBJECT:
return "object";
case LYJSON_OBJECT_CLOSED:
return "object closed";
case LYJSON_OBJECT_EMPTY:
return "empty object";
case LYJSON_ARRAY:
return "array";
case LYJSON_ARRAY_CLOSED:
return "array closed";
case LYJSON_ARRAY_EMPTY:
return "empty array";
case LYJSON_NUMBER:
return "number";
case LYJSON_STRING:
return "string";
case LYJSON_END:
return "end of input";
}
return "";
}
static LY_ERR
skip_ws(struct lyjson_ctx *jsonctx)
{
/* skip leading whitespaces */
while (*jsonctx->in->current != '\0' && is_jsonws(*jsonctx->in->current)) {
if (*jsonctx->in->current == '\n') {
LY_IN_NEW_LINE(jsonctx->in);
}
ly_in_skip(jsonctx->in, 1);
}
if (*jsonctx->in->current == '\0') {
JSON_PUSH_STATUS_RET(jsonctx, LYJSON_END);
}
return LY_SUCCESS;
}
/*
* @brief Set value corresponding to the current context's status
*/
static void
lyjson_ctx_set_value(struct lyjson_ctx *jsonctx, const char *value, size_t value_len, ly_bool dynamic)
{
assert(jsonctx);
if (jsonctx->dynamic) {
free((char *)jsonctx->value);
}
jsonctx->value = value;
jsonctx->value_len = value_len;
jsonctx->dynamic = dynamic;
}
static LY_ERR
lyjson_check_next(struct lyjson_ctx *jsonctx)
{
if (jsonctx->status.count == 1) {
/* top level value (JSON-text), ws expected */
if ((*jsonctx->in->current == '\0') || is_jsonws(*jsonctx->in->current)) {
return LY_SUCCESS;
}
} else if (lyjson_ctx_status(jsonctx, 1) == LYJSON_OBJECT) {
LY_CHECK_RET(skip_ws(jsonctx));
if ((*jsonctx->in->current == ',') || (*jsonctx->in->current == '}')) {
return LY_SUCCESS;
}
} else if (lyjson_ctx_status(jsonctx, 1) == LYJSON_ARRAY) {
LY_CHECK_RET(skip_ws(jsonctx));
if ((*jsonctx->in->current == ',') || (*jsonctx->in->current == ']')) {
return LY_SUCCESS;
}
}
LOGVAL(jsonctx->ctx, LYVE_SYNTAX, "Unexpected character \"%c\" after JSON %s.",
*jsonctx->in->current, lyjson_token2str(lyjson_ctx_status(jsonctx, 0)));
return LY_EVALID;
}
/**
* Input is expected to start after the opening quotation-mark.
* When succeeds, input is moved after the closing quotation-mark.
*/
static LY_ERR
lyjson_string_(struct lyjson_ctx *jsonctx)
{
#define BUFSIZE 24
#define BUFSIZE_STEP 128
const char *in = jsonctx->in->current, *start;
char *buf = NULL;
size_t offset; /* read offset in input buffer */
size_t len; /* length of the output string (write offset in output buffer) */
size_t size = 0; /* size of the output buffer */
size_t u;
uint64_t start_line;
assert(jsonctx);
/* init */
start = in;
start_line = jsonctx->in->line;
offset = len = 0;
/* parse */
while (in[offset]) {
if (in[offset] == '\\') {
/* escape sequence */
const char *slash = &in[offset];
uint32_t value;
uint8_t i = 1;
if (!buf) {
/* prepare output buffer */
buf = malloc(BUFSIZE);
LY_CHECK_ERR_RET(!buf, LOGMEM(jsonctx->ctx), LY_EMEM);
size = BUFSIZE;
}
/* allocate enough for the offset and next character,
* we will need 4 bytes at most since we support only the predefined
* (one-char) entities and character references */
if (len + offset + 4 >= size) {
size_t increment;
for (increment = BUFSIZE_STEP; len + offset + 4 >= size + increment; increment += BUFSIZE_STEP) {}
buf = ly_realloc(buf, size + increment);
LY_CHECK_ERR_RET(!buf, LOGMEM(jsonctx->ctx), LY_EMEM);
size += BUFSIZE_STEP;
}
if (offset) {
/* store what we have so far */
memcpy(&buf[len], in, offset);
len += offset;
in += offset;
offset = 0;
}
switch (in[++offset]) {
case '"':
/* quotation mark */
value = 0x22;
break;
case '\\':
/* reverse solidus */
value = 0x5c;
break;
case '/':
/* solidus */
value = 0x2f;
break;
case 'b':
/* backspace */
value = 0x08;
break;
case 'f':
/* form feed */
value = 0x0c;
break;
case 'n':
/* line feed */
value = 0x0a;
break;
case 'r':
/* carriage return */
value = 0x0d;
break;
case 't':
/* tab */
value = 0x09;
break;
case 'u':
/* Basic Multilingual Plane character \uXXXX */
offset++;
for (value = i = 0; i < 4; i++) {
if (!in[offset + i]) {
LOGVAL(jsonctx->ctx, LYVE_SYNTAX, "Invalid basic multilingual plane character \"%s\".", slash);
goto error;
} else if (isdigit(in[offset + i])) {
u = (in[offset + i] - '0');
} else if (in[offset + i] > 'F') {
u = LY_BASE_DEC + (in[offset + i] - 'a');
} else {
u = LY_BASE_DEC + (in[offset + i] - 'A');
}
value = (LY_BASE_HEX * value) + u;
}
break;
default:
/* invalid escape sequence */
LOGVAL(jsonctx->ctx, LYVE_SYNTAX, "Invalid character escape sequence \\%c.", in[offset]);
goto error;
}
offset += i; /* add read escaped characters */
LY_CHECK_ERR_GOTO(ly_pututf8(&buf[len], value, &u),
LOGVAL(jsonctx->ctx, LYVE_SYNTAX, "Invalid character reference \"%.*s\" (0x%08x).",
(int)(&in[offset] - slash), slash, value),
error);
len += u; /* update number of bytes in buffer */
in += offset; /* move the input by the processed bytes stored in the buffer ... */
offset = 0; /* ... and reset the offset index for future moving data into buffer */
} else if (in[offset] == '"') {
/* end of string */
if (buf) {
/* realloc exact size string */
buf = ly_realloc(buf, len + offset + 1);
LY_CHECK_ERR_RET(!buf, LOGMEM(jsonctx->ctx), LY_EMEM);
size = len + offset + 1;
if (offset) {
memcpy(&buf[len], in, offset);
}
/* set terminating NULL byte */
buf[len + offset] = '\0';
}
len += offset;
++offset;
in += offset;
goto success;
} else {
/* get it as UTF-8 character for check */
const char *c = &in[offset];
uint32_t code = 0;
size_t code_len = 0;
LY_CHECK_ERR_GOTO(ly_getutf8(&c, &code, &code_len),
LOGVAL(jsonctx->ctx, LY_VCODE_INCHAR, in[offset]), error);
LY_CHECK_ERR_GOTO(!is_jsonstrchar(code),
LOGVAL(jsonctx->ctx, LYVE_SYNTAX, "Invalid character in JSON string \"%.*s\" (0x%08x).",
(int)(&in[offset] - start + code_len), start, code),
error);
/* character is ok, continue */
offset += code_len;
}
}
/* EOF reached before endchar */
LOGVAL(jsonctx->ctx, LY_VCODE_EOF);
LOGVAL_LINE(jsonctx->ctx, start_line, LYVE_SYNTAX, "Missing quotation-mark at the end of a JSON string.");
error:
free(buf);
return LY_EVALID;
success:
jsonctx->in->current = in;
if (buf) {
lyjson_ctx_set_value(jsonctx, buf, len, 1);
} else {
lyjson_ctx_set_value(jsonctx, start, len, 0);
}
return LY_SUCCESS;
#undef BUFSIZE
#undef BUFSIZE_STEP
}
/*
*
* Wrapper around lyjson_string_() adding LYJSON_STRING status into context to allow using lyjson_string_() for parsing object's name.
*/
static LY_ERR
lyjson_string(struct lyjson_ctx *jsonctx)
{
LY_CHECK_RET(lyjson_string_(jsonctx));
JSON_PUSH_STATUS_RET(jsonctx, LYJSON_STRING);
LY_CHECK_RET(lyjson_check_next(jsonctx));
return LY_SUCCESS;
}
/**
* @brief Calculate how many @p c characters there are in a row.
*
* @param[in] str Count from this position.
* @param[in] end Position after the last checked character.
* @param[in] c Checked character.
* @param[in] backwards Set to 1, if to proceed from end-1 to str.
* @return Number of characters in a row.
*/
static uint32_t
lyjson_count_in_row(const char *str, const char *end, char c, ly_bool backwards)
{
uint32_t cnt;
assert(str && end);
if (str >= end) {
return 0;
}
if (!backwards) {
for (cnt = 0; (str != end) && (*str == c); ++str, ++cnt) {}
} else {
--end;
--str;
for (cnt = 0; (str != end) && (*end == c); --end, ++cnt) {}
}
return cnt;
}
/**
* @brief Check if the number can be shortened to zero.
*
* @param[in] in Start of input string;
* @param[in] end End of input string;
* @return 1 if number is zero, otherwise 0.
*/
static ly_bool
lyjson_number_is_zero(const char *in, const char *end)
{
assert(in < end);
if ((in[0] == '-') || (in[0] == '+')) {
in++;
assert(in < end);
}
if ((in[0] == '0') && (in[1] == '.')) {
in += 2;
if (!(in < end)) {
return 1;
}
}
return lyjson_count_in_row(in, end, '0', 0) == end - in;
}
/**
* @brief Allocate buffer for number in string format.
*
* @param[in] jsonctx JSON context.
* @param[in] num_len Required space in bytes for a number.
* Terminating null byte is added by default.
* @param[out] buffer Output allocated buffer.
* @return LY_ERR value.
*/
static LY_ERR
lyjson_get_buffer_for_number(const struct ly_ctx *ctx, uint64_t num_len, char **buffer)
{
*buffer = NULL;
LY_CHECK_ERR_RET((num_len + 1) > LY_NUMBER_MAXLEN, LOGVAL(ctx, LYVE_SEMANTICS,
"Number encoded as a string exceeded the LY_NUMBER_MAXLEN limit."), LY_EVALID);
/* allocate buffer for the result (add NULL-byte) */
*buffer = malloc(num_len + 1);
LY_CHECK_ERR_RET(!(*buffer), LOGMEM(ctx), LY_EMEM);
return LY_SUCCESS;
}
/**
* @brief Copy the 'numeric part' (@p num) except its decimal point
* (@p dec_point) and insert the new decimal point (@p dp_position)
* only if it is to be placed in the 'numeric part' range (@p num).
*
* @param[in] num Begin of the 'numeric part'.
* @param[in] num_len Length of the 'numeric part'.
* @param[in] dec_point Pointer to the old decimal point.
* If it has a NULL value, it is ignored.
* @param[in] dp_position Position of the new decimal point.
* If it has a negative value, it is ignored.
* @param[out] dst Memory into which the copied result is written.
* @return Number of characters written to the @p dst.
*/
static uint32_t
lyjson_exp_number_copy_num_part(const char *num, uint32_t num_len,
char *dec_point, int32_t dp_position, char *dst)
{
int32_t dec_point_idx;
int32_t n, d;
assert(num && dst);
dec_point_idx = dec_point ? dec_point - num : INT32_MAX;
assert((dec_point_idx >= 0) && (dec_point_idx != dp_position));
for (n = 0, d = 0; (uint32_t)n < num_len; n++) {
if (n == dec_point_idx) {
continue;
} else if (d == dp_position) {
dst[d++] = '.';
dst[d++] = num[n];
} else {
dst[d++] = num[n];
}
}
return d;
}
/**
* @brief Convert JSON number with exponent into the representation
* used by YANG.
*
* The input numeric string must be syntactically valid. Also, before
* calling this function, checks should be performed using the
* ::lyjson_number_is_zero().
*
* @param[in] ctx Context for the error message.
* @param[in] in Beginning of the string containing the number.
* @param[in] exponent Pointer to the letter E/e.
* @param[in] total_len Total size of the input number.
* @param[out] res Conversion result.
* @param[out] res_len Length of the result.
* @return LY_ERR value.
*/
static LY_ERR
lyjson_exp_number(const struct ly_ctx *ctx, const char *in, const char *exponent,
uint64_t total_len, char **res, uint64_t *res_len)
{
#define MAYBE_WRITE_MINUS(ARRAY, INDEX, FLAG) \
if (FLAG) { \
ARRAY[INDEX++] = '-'; \
}
/* Length of leading zero followed by the decimal point. */
#define LEADING_ZERO 1
/* Flags for the ::lyjson_count_in_row() */
#define FORWARD 0
#define BACKWARD 1
/* Buffer where the result is stored. */
char *buf;
/* Size without space for terminating NULL-byte. */
uint64_t buf_len;
/* Index to buf. */
uint32_t i = 0;
/* A 'numeric part' doesn't contain a minus sign or an leading zero.
* For example, in 0.45, there is the leading zero.
*/
const char *num;
/* Length of the 'numeric part' ends before E/e. */
uint16_t num_len;
/* Position of decimal point in the num. */
char *dec_point;
/* Final position of decimal point in the buf. */
int32_t dp_position;
/* Exponent as integer. */
long int e_val;
/* Byte for the decimal point. */
int8_t dot;
/* Required additional byte for the minus sign. */
uint8_t minus;
/* The number of zeros. */
long zeros;
/* If the number starts with leading zero followed by the decimal point. */
ly_bool leading_zero;
assert(ctx && in && exponent && res && res_len && (total_len > 2));
assert((in < exponent) && ((*exponent == 'e') || (*exponent == 'E')));
if ((exponent - in) > UINT16_MAX) {
LOGVAL(ctx, LYVE_SEMANTICS, "JSON number is too long.");
return LY_EVALID;
}
/* Convert exponent. */
errno = 0;
e_val = strtol(exponent + 1, NULL, LY_BASE_DEC);
if (errno || (labs(e_val) > UINT16_MAX)) {
LOGVAL(ctx, LYVE_SEMANTICS,
"Exponent out-of-bounds in a JSON Number value (%.*s).",
total_len, in);
return LY_EVALID;
}
minus = in[0] == '-';
if (in[minus] == '0') {
assert(in[minus + 1] == '.');
leading_zero = 1;
/* The leading zero has been found, it will be skipped. */
num = &in[minus + 1];
} else {
leading_zero = 0;
/* Set to the first number. */
num = &in[minus];
}
num_len = exponent - num;
/* Find the location of the decimal points. */
dec_point = ly_strnchr(num, '.', num_len);
dp_position = dec_point ?
dec_point - num + e_val :
num_len + e_val;
/* Remove zeros after the decimal point from the end of
* the 'numeric part' because these are useless.
* (For example, in 40.001000 these are the last 3).
*/
num_len -= dp_position > 0 ?
lyjson_count_in_row(num + dp_position - 1, exponent, '0', BACKWARD) :
lyjson_count_in_row(num, exponent, '0', BACKWARD);
/* Decide what to do with the dot from the 'numeric part'. */
if (dec_point && ((int32_t)(num_len - 1) == dp_position)) {
/* Decimal point in the last place is useless. */
dot = -1;
} else if (dec_point) {
/* Decimal point is shifted. */
dot = 0;
} else {
/* Additional byte for the decimal point is requred. */
dot = 1;
}
/* Final composition of the result. */
if (dp_position <= 0) {
/* Adding decimal point before the integer with adding additional zero(s). */
zeros = labs(dp_position);
buf_len = minus + LEADING_ZERO + dot + zeros + num_len;
LY_CHECK_RET(lyjson_get_buffer_for_number(ctx, buf_len, &buf));
MAYBE_WRITE_MINUS(buf, i, minus);
buf[i++] = '0';
buf[i++] = '.';
memset(buf + i, '0', zeros);
i += zeros;
dp_position = -1;
lyjson_exp_number_copy_num_part(num, num_len, dec_point, dp_position, buf + i);
} else if (leading_zero && (dp_position < (ssize_t)num_len)) {
/* Insert decimal point between the integer's digits. */
/* Set a new range of 'numeric part'. Old decimal point is skipped. */
num++;
num_len--;
dp_position--;
/* Get the number of useless zeros between the old
* and new decimal point. For example, in the number 0.005E1,
* there is one useless zero.
*/
zeros = lyjson_count_in_row(num, num + dp_position + 1, '0', FORWARD);
/* If the new decimal point will be in the place of the first non-zero subnumber. */
if (zeros == (dp_position + 1)) {
/* keep one zero as leading zero */
zeros--;
/* new decimal point will be behind the leading zero */
dp_position = 1;
dot = 1;
} else {
dot = 0;
}
buf_len = minus + dot + (num_len - zeros);
LY_CHECK_RET(lyjson_get_buffer_for_number(ctx, buf_len, &buf));
MAYBE_WRITE_MINUS(buf, i, minus);
/* Skip useless zeros and copy. */
lyjson_exp_number_copy_num_part(num + zeros, num_len - zeros, NULL, dp_position, buf + i);
} else if (dp_position < (ssize_t)num_len) {
/* Insert decimal point between the integer's digits. */
buf_len = minus + dot + num_len;
LY_CHECK_RET(lyjson_get_buffer_for_number(ctx, buf_len, &buf));
MAYBE_WRITE_MINUS(buf, i, minus);
lyjson_exp_number_copy_num_part(num, num_len, dec_point, dp_position, buf + i);
} else if (leading_zero) {
/* Adding decimal point after the decimal value make the integer result. */
/* Set a new range of 'numeric part'. Old decimal point is skipped. */
num++;
num_len--;
/* Get the number of useless zeros. */
zeros = lyjson_count_in_row(num, num + num_len, '0', FORWARD);
buf_len = minus + dp_position - zeros;
LY_CHECK_RET(lyjson_get_buffer_for_number(ctx, buf_len, &buf));
MAYBE_WRITE_MINUS(buf, i, minus);
/* Skip useless zeros and copy. */
i += lyjson_exp_number_copy_num_part(num + zeros, num_len - zeros, NULL, dp_position, buf + i);
/* Add multiples of ten behind the 'numeric part'. */
memset(buf + i, '0', buf_len - i);
} else {
/* Adding decimal point after the decimal value make the integer result. */
buf_len = minus + dp_position;
LY_CHECK_RET(lyjson_get_buffer_for_number(ctx, buf_len, &buf));
MAYBE_WRITE_MINUS(buf, i, minus);
i += lyjson_exp_number_copy_num_part(num, num_len, dec_point, dp_position, buf + i);
/* Add multiples of ten behind the 'numeric part'. */
memset(buf + i, '0', buf_len - i);
}
buf[buf_len] = '\0';
*res = buf;
*res_len = buf_len;
#undef MAYBE_WRITE_MINUS
#undef LEADING_ZERO
#undef FORWARD
#undef BACKWARD
return LY_SUCCESS;
}
static LY_ERR
lyjson_number(struct lyjson_ctx *jsonctx)
{
size_t offset = 0, num_len;
const char *in = jsonctx->in->current, *exponent = NULL;
uint8_t minus = 0;
char *num;
if (in[offset] == '-') {
++offset;
minus = 1;
}
if (in[offset] == '0') {
++offset;
} else if (isdigit(in[offset])) {
++offset;
while (isdigit(in[offset])) {
++offset;
}
} else {
invalid_character:
if (in[offset]) {
LOGVAL(jsonctx->ctx, LYVE_SYNTAX, "Invalid character in JSON Number value (\"%c\").", in[offset]);
} else {
LOGVAL(jsonctx->ctx, LY_VCODE_EOF);
}
return LY_EVALID;
}
if (in[offset] == '.') {
++offset;
if (!isdigit(in[offset])) {
goto invalid_character;
}
while (isdigit(in[offset])) {
++offset;
}
}
if ((in[offset] == 'e') || (in[offset] == 'E')) {
exponent = &in[offset];
++offset;
if ((in[offset] == '+') || (in[offset] == '-')) {
++offset;
}
if (!isdigit(in[offset])) {
goto invalid_character;
}
while (isdigit(in[offset])) {
++offset;
}
}
if (lyjson_number_is_zero(in, exponent ? exponent : &in[offset])) {
lyjson_ctx_set_value(jsonctx, in, minus + 1, 0);
} else if (exponent && lyjson_number_is_zero(exponent + 1, &in[offset])) {
lyjson_ctx_set_value(jsonctx, in, exponent - in, 0);
} else if (exponent) {
LY_CHECK_RET(lyjson_exp_number(jsonctx->ctx, in, exponent, offset, &num, &num_len));
lyjson_ctx_set_value(jsonctx, num, num_len, 1);
} else {
if (offset > LY_NUMBER_MAXLEN) {
LOGVAL(jsonctx->ctx, LYVE_SEMANTICS,
"Number encoded as a string exceeded the LY_NUMBER_MAXLEN limit.");
return LY_EVALID;
}
lyjson_ctx_set_value(jsonctx, in, offset, 0);
}
ly_in_skip(jsonctx->in, offset);
JSON_PUSH_STATUS_RET(jsonctx, LYJSON_NUMBER);
LY_CHECK_RET(lyjson_check_next(jsonctx));
return LY_SUCCESS;
}
static LY_ERR
lyjson_object_name(struct lyjson_ctx *jsonctx)
{
if (*jsonctx->in->current != '"') {
LOGVAL(jsonctx->ctx, LY_VCODE_INSTREXP, LY_VCODE_INSTREXP_len(jsonctx->in->current),
jsonctx->in->current, "a JSON object's member");
return LY_EVALID;
}
ly_in_skip(jsonctx->in, 1);
LY_CHECK_RET(lyjson_string_(jsonctx));
LY_CHECK_RET(skip_ws(jsonctx));
if (*jsonctx->in->current != ':') {
LOGVAL(jsonctx->ctx, LY_VCODE_INSTREXP, LY_VCODE_INSTREXP_len(jsonctx->in->current), jsonctx->in->current,
"a JSON object's name-separator ':'");
return LY_EVALID;
}
ly_in_skip(jsonctx->in, 1);
LY_CHECK_RET(skip_ws(jsonctx));
return LY_SUCCESS;
}
static LY_ERR
lyjson_object(struct lyjson_ctx *jsonctx)
{
LY_CHECK_RET(skip_ws(jsonctx));
if (*jsonctx->in->current == '}') {
assert(jsonctx->depth);
jsonctx->depth--;
/* empty object */
ly_in_skip(jsonctx->in, 1);
lyjson_ctx_set_value(jsonctx, NULL, 0, 0);
JSON_PUSH_STATUS_RET(jsonctx, LYJSON_OBJECT_EMPTY);
return LY_SUCCESS;
}
LY_CHECK_RET(lyjson_object_name(jsonctx));
/* output data are set by lyjson_string_() */
JSON_PUSH_STATUS_RET(jsonctx, LYJSON_OBJECT);
return LY_SUCCESS;
}
/*
* @brief Process JSON array envelope
*
*
*
* @param[in] jsonctx JSON parser context
* @return LY_SUCCESS or LY_EMEM
*/
static LY_ERR
lyjson_array(struct lyjson_ctx *jsonctx)
{
LY_CHECK_RET(skip_ws(jsonctx));
if (*jsonctx->in->current == ']') {
/* empty array */
ly_in_skip(jsonctx->in, 1);
JSON_PUSH_STATUS_RET(jsonctx, LYJSON_ARRAY_EMPTY);
} else {
JSON_PUSH_STATUS_RET(jsonctx, LYJSON_ARRAY);
}
/* erase previous values, array has no value on its own */
lyjson_ctx_set_value(jsonctx, NULL, 0, 0);
return LY_SUCCESS;
}
static LY_ERR
lyjson_value(struct lyjson_ctx *jsonctx)
{
if (jsonctx->status.count && (lyjson_ctx_status(jsonctx, 0) == LYJSON_END)) {
return LY_SUCCESS;
}
if ((*jsonctx->in->current == 'f') && !strncmp(jsonctx->in->current, "false", ly_strlen_const("false"))) {
/* false */
lyjson_ctx_set_value(jsonctx, jsonctx->in->current, ly_strlen_const("false"), 0);
ly_in_skip(jsonctx->in, ly_strlen_const("false"));
JSON_PUSH_STATUS_RET(jsonctx, LYJSON_FALSE);
LY_CHECK_RET(lyjson_check_next(jsonctx));
} else if ((*jsonctx->in->current == 't') && !strncmp(jsonctx->in->current, "true", ly_strlen_const("true"))) {
/* true */
lyjson_ctx_set_value(jsonctx, jsonctx->in->current, ly_strlen_const("true"), 0);
ly_in_skip(jsonctx->in, ly_strlen_const("true"));
JSON_PUSH_STATUS_RET(jsonctx, LYJSON_TRUE);
LY_CHECK_RET(lyjson_check_next(jsonctx));
} else if ((*jsonctx->in->current == 'n') && !strncmp(jsonctx->in->current, "null", ly_strlen_const("null"))) {
/* none */
lyjson_ctx_set_value(jsonctx, "", 0, 0);
ly_in_skip(jsonctx->in, ly_strlen_const("null"));
JSON_PUSH_STATUS_RET(jsonctx, LYJSON_NULL);
LY_CHECK_RET(lyjson_check_next(jsonctx));
} else if (*jsonctx->in->current == '"') {
/* string */
ly_in_skip(jsonctx->in, 1);
LY_CHECK_RET(lyjson_string(jsonctx));
} else if (*jsonctx->in->current == '[') {
/* array */
ly_in_skip(jsonctx->in, 1);
LY_CHECK_RET(lyjson_array(jsonctx));
} else if (*jsonctx->in->current == '{') {
jsonctx->depth++;
if (jsonctx->depth > LY_MAX_BLOCK_DEPTH) {
LOGERR(jsonctx->ctx, LY_EINVAL,
"The maximum number of block nestings has been exceeded.");
return LY_EINVAL;
}
/* object */
ly_in_skip(jsonctx->in, 1);
LY_CHECK_RET(lyjson_object(jsonctx));
} else if ((*jsonctx->in->current == '-') || ((*jsonctx->in->current >= '0') && (*jsonctx->in->current <= '9'))) {
/* number */
LY_CHECK_RET(lyjson_number(jsonctx));
} else {
/* unexpected value */
LOGVAL(jsonctx->ctx, LY_VCODE_INSTREXP, LY_VCODE_INSTREXP_len(jsonctx->in->current),
jsonctx->in->current, "a JSON value");
return LY_EVALID;
}
return LY_SUCCESS;
}
LY_ERR
lyjson_ctx_new(const struct ly_ctx *ctx, struct ly_in *in, struct lyjson_ctx **jsonctx_p)
{
LY_ERR ret = LY_SUCCESS;
struct lyjson_ctx *jsonctx;
assert(ctx);
assert(in);
assert(jsonctx_p);
/* new context */
jsonctx = calloc(1, sizeof *jsonctx);
LY_CHECK_ERR_RET(!jsonctx, LOGMEM(ctx), LY_EMEM);
jsonctx->ctx = ctx;
jsonctx->in = in;
LOG_LOCINIT(NULL, NULL, NULL, in);
/* parse JSON value, if any */
LY_CHECK_GOTO(ret = skip_ws(jsonctx), cleanup);
if (lyjson_ctx_status(jsonctx, 0) == LYJSON_END) {
/* empty data input */
goto cleanup;
}
ret = lyjson_value(jsonctx);
if ((jsonctx->status.count > 1) && (lyjson_ctx_status(jsonctx, 0) == LYJSON_END)) {
LOGVAL(jsonctx->ctx, LY_VCODE_EOF);
ret = LY_EVALID;
}
cleanup:
if (ret) {
lyjson_ctx_free(jsonctx);
} else {
*jsonctx_p = jsonctx;
}
return ret;
}
void
lyjson_ctx_backup(struct lyjson_ctx *jsonctx)
{
if (jsonctx->backup.dynamic) {
free((char *)jsonctx->backup.value);
}
jsonctx->backup.status = lyjson_ctx_status(jsonctx, 0);
jsonctx->backup.status_count = jsonctx->status.count;
jsonctx->backup.value = jsonctx->value;
jsonctx->backup.value_len = jsonctx->value_len;
jsonctx->backup.input = jsonctx->in->current;
jsonctx->backup.dynamic = jsonctx->dynamic;
jsonctx->backup.depth = jsonctx->depth;
jsonctx->dynamic = 0;
}
void
lyjson_ctx_restore(struct lyjson_ctx *jsonctx)
{
if (jsonctx->dynamic) {
free((char *)jsonctx->value);
}
jsonctx->status.count = jsonctx->backup.status_count;
jsonctx->status.objs[jsonctx->backup.status_count - 1] = (void *)jsonctx->backup.status;
jsonctx->value = jsonctx->backup.value;
jsonctx->value_len = jsonctx->backup.value_len;
jsonctx->in->current = jsonctx->backup.input;
jsonctx->dynamic = jsonctx->backup.dynamic;
jsonctx->depth = jsonctx->backup.depth;
jsonctx->backup.dynamic = 0;
}
LY_ERR
lyjson_ctx_next(struct lyjson_ctx *jsonctx, enum LYJSON_PARSER_STATUS *status)
{
LY_ERR ret = LY_SUCCESS;
ly_bool toplevel = 0;
enum LYJSON_PARSER_STATUS prev;
assert(jsonctx);
prev = lyjson_ctx_status(jsonctx, 0);
if ((prev == LYJSON_OBJECT) || (prev == LYJSON_ARRAY)) {
/* get value for the object's member OR the first value in the array */
ret = lyjson_value(jsonctx);
goto result;
} else {
/* the previous token is closed and should be completely processed */
JSON_POP_STATUS_RET(jsonctx);
prev = lyjson_ctx_status(jsonctx, 0);
}
if (!jsonctx->status.count) {
/* we are done with the top level value */
toplevel = 1;
}
LY_CHECK_RET(skip_ws(jsonctx));
if (toplevel && !jsonctx->status.count) {
/* EOF expected, but there are some data after the top level token */
LOGVAL(jsonctx->ctx, LYVE_SYNTAX, "Expecting end-of-input, but some data follows the top level JSON value.");
return LY_EVALID;
}
if (toplevel) {
/* we are done */
return LY_SUCCESS;
}
/* continue with the next token */
assert(prev == LYJSON_OBJECT || prev == LYJSON_ARRAY);
if (*jsonctx->in->current == ',') {
/* sibling item in the ... */
ly_in_skip(jsonctx->in, 1);
LY_CHECK_RET(skip_ws(jsonctx));
if (prev == LYJSON_OBJECT) {
/* ... object - get another object's member */
ret = lyjson_object_name(jsonctx);
} else { /* LYJSON_ARRAY */
/* ... array - get another complete value */
ret = lyjson_value(jsonctx);
}
} else if (((prev == LYJSON_OBJECT) && (*jsonctx->in->current == '}')) || ((prev == LYJSON_ARRAY) && (*jsonctx->in->current == ']'))) {
if (*jsonctx->in->current == '}') {
assert(jsonctx->depth);
jsonctx->depth--;
}
ly_in_skip(jsonctx->in, 1);
JSON_POP_STATUS_RET(jsonctx);
JSON_PUSH_STATUS_RET(jsonctx, prev + 1);
} else {
/* unexpected value */
LOGVAL(jsonctx->ctx, LY_VCODE_INSTREXP, LY_VCODE_INSTREXP_len(jsonctx->in->current), jsonctx->in->current,
prev == LYJSON_ARRAY ? "another JSON value in array" : "another JSON object's member");
return LY_EVALID;
}
result:
if ((ret == LY_SUCCESS) && (jsonctx->status.count > 1) && (lyjson_ctx_status(jsonctx, 0) == LYJSON_END)) {
LOGVAL(jsonctx->ctx, LY_VCODE_EOF);
ret = LY_EVALID;
}
if ((ret == LY_SUCCESS) && status) {
*status = lyjson_ctx_status(jsonctx, 0);
}
return ret;
}
enum LYJSON_PARSER_STATUS
lyjson_ctx_status(struct lyjson_ctx *jsonctx, uint32_t index)
{
assert(jsonctx);
if (jsonctx->status.count < index) {
return LYJSON_ERROR;
} else if (jsonctx->status.count == index) {
return LYJSON_ROOT;
} else {
return (enum LYJSON_PARSER_STATUS)(uintptr_t)jsonctx->status.objs[jsonctx->status.count - (index + 1)];
}
}
void
lyjson_ctx_free(struct lyjson_ctx *jsonctx)
{
if (!jsonctx) {
return;
}
LOG_LOCBACK(0, 0, 0, 1);
if (jsonctx->dynamic) {
free((char *)jsonctx->value);
}
if (jsonctx->backup.dynamic) {
free((char *)jsonctx->backup.value);
}
ly_set_erase(&jsonctx->status, NULL);
free(jsonctx);
}