json.c revision 2bb4c7e384c31de4727f1330da3f4de2f0bb7784
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2014 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <sys/types.h>
#include <math.h>
#include "macro.h"
#include "log.h"
#include "util.h"
#include "utf8.h"
#include "json.h"
enum {
STATE_NULL,
STATE_VALUE,
STATE_VALUE_POST,
};
static void inc_lines(unsigned *line, const char *s, size_t n) {
const char *p = s;
if (!line)
return;
for (;;) {
const char *f;
f = memchr(p, '\n', n);
if (!f)
return;
n -= (f - p) + 1;
p = f + 1;
(*line)++;
}
}
static int json_parse_string(const char **p, char **ret) {
_cleanup_free_ char *s = NULL;
size_t n = 0, allocated = 0;
const char *c;
assert(p);
assert(*p);
assert(ret);
c = *p;
if (*c != '"')
return -EINVAL;
c++;
for (;;) {
int len;
/* Check for EOF */
if (*c == 0)
return -EINVAL;
/* Check for control characters 0x00..0x1f */
if (*c > 0 && *c < ' ')
return -EINVAL;
/* Check for control character 0x7f */
if (*c == 0x7f)
return -EINVAL;
if (*c == '"') {
if (!s) {
s = strdup("");
if (!s)
return -ENOMEM;
} else
s[n] = 0;
*p = c + 1;
*ret = s;
s = NULL;
return JSON_STRING;
}
if (*c == '\\') {
char ch = 0;
c++;
if (*c == 0)
return -EINVAL;
if (IN_SET(*c, '"', '\\', '/'))
ch = *c;
else if (*c == 'b')
ch = '\b';
else if (*c == 'f')
ch = '\f';
else if (*c == 'n')
ch = '\n';
else if (*c == 'r')
ch = '\r';
else if (*c == 't')
ch = '\t';
else if (*c == 'u') {
int aa, bb, cc, dd;
uint16_t x;
aa = unhexchar(c[1]);
if (aa < 0)
return -EINVAL;
bb = unhexchar(c[2]);
if (bb < 0)
return -EINVAL;
cc = unhexchar(c[3]);
if (cc < 0)
return -EINVAL;
dd = unhexchar(c[4]);
if (dd < 0)
return -EINVAL;
x = ((uint16_t) aa << 12) |
((uint16_t) bb << 8) |
((uint16_t) cc << 4) |
((uint16_t) dd);
if (x <= 0)
return -EINVAL;
if (!GREEDY_REALLOC(s, allocated, n + 4))
return -ENOMEM;
n += utf8_encode_unichar(s + n, x);
c += 5;
continue;
} else
return -EINVAL;
if (!GREEDY_REALLOC(s, allocated, n + 2))
return -ENOMEM;
s[n++] = ch;
c ++;
continue;
}
len = utf8_encoded_valid_unichar(c);
if (len < 0)
return len;
if (!GREEDY_REALLOC(s, allocated, n + len + 1))
return -ENOMEM;
memcpy(s + n, c, len);
n += len;
c += len;
}
}
static int json_parse_number(const char **p, union json_value *ret) {
bool negative = false, exponent_negative = false, is_double = false;
double x = 0.0, y = 0.0, exponent = 0.0, shift = 1.0;
intmax_t i = 0;
const char *c;
assert(p);
assert(*p);
assert(ret);
c = *p;
if (*c == '-') {
negative = true;
c++;
}
if (*c == '0')
c++;
else {
if (!strchr("123456789", *c) || *c == 0)
return -EINVAL;
do {
if (!is_double) {
int64_t t;
t = 10 * i + (*c - '0');
if (t < i) /* overflow */
is_double = false;
else
i = t;
}
x = 10.0 * x + (*c - '0');
c++;
} while (strchr("0123456789", *c) && *c != 0);
}
if (*c == '.') {
is_double = true;
c++;
if (!strchr("0123456789", *c) || *c == 0)
return -EINVAL;
do {
y = 10.0 * y + (*c - '0');
shift = 10.0 * shift;
c++;
} while (strchr("0123456789", *c) && *c != 0);
}
if (*c == 'e' || *c == 'E') {
is_double = true;
c++;
if (*c == '-') {
exponent_negative = true;
c++;
} else if (*c == '+')
c++;
if (!strchr("0123456789", *c) || *c == 0)
return -EINVAL;
do {
exponent = 10.0 * exponent + (*c - '0');
c++;
} while (strchr("0123456789", *c) && *c != 0);
}
if (*c != 0)
return -EINVAL;
*p = c;
if (is_double) {
ret->real = ((negative ? -1.0 : 1.0) * (x + (y / shift))) * exp10((exponent_negative ? -1.0 : 1.0) * exponent);
return JSON_REAL;
} else {
ret->integer = negative ? -i : i;
return JSON_INTEGER;
}
}
int json_tokenize(
const char **p,
char **ret_string,
union json_value *ret_value,
void **state,
unsigned *line) {
const char *c;
int t;
int r;
assert(p);
assert(*p);
assert(ret_string);
assert(ret_value);
assert(state);
t = PTR_TO_INT(*state);
c = *p;
if (t == STATE_NULL) {
if (line)
*line = 1;
t = STATE_VALUE;
}
for (;;) {
const char *b;
b = c + strspn(c, WHITESPACE);
if (*b == 0)
return JSON_END;
inc_lines(line, c, b - c);
c = b;
switch (t) {
case STATE_VALUE:
if (*c == '{') {
*ret_string = NULL;
*ret_value = JSON_VALUE_NULL;
*p = c + 1;
*state = INT_TO_PTR(STATE_VALUE);
return JSON_OBJECT_OPEN;
} else if (*c == '}') {
*ret_string = NULL;
*ret_value = JSON_VALUE_NULL;
*p = c + 1;
*state = INT_TO_PTR(STATE_VALUE_POST);
return JSON_OBJECT_CLOSE;
} else if (*c == '[') {
*ret_string = NULL;
*ret_value = JSON_VALUE_NULL;
*p = c + 1;
*state = INT_TO_PTR(STATE_VALUE);
return JSON_ARRAY_OPEN;
} else if (*c == ']') {
*ret_string = NULL;
*ret_value = JSON_VALUE_NULL;
*p = c + 1;
*state = INT_TO_PTR(STATE_VALUE_POST);
return JSON_ARRAY_CLOSE;
} else if (*c == '"') {
r = json_parse_string(&c, ret_string);
if (r < 0)
return r;
*ret_value = JSON_VALUE_NULL;
*p = c;
*state = INT_TO_PTR(STATE_VALUE_POST);
return r;
} else if (strchr("-0123456789", *c)) {
r = json_parse_number(&c, ret_value);
if (r < 0)
return r;
*ret_string = NULL;
*p = c;
*state = INT_TO_PTR(STATE_VALUE_POST);
return r;
} else if (startswith(c, "true")) {
*ret_string = NULL;
ret_value->boolean = true;
*p = c + 4;
*state = INT_TO_PTR(STATE_VALUE_POST);
return JSON_BOOLEAN;
} else if (startswith(c, "false")) {
*ret_string = NULL;
ret_value->boolean = false;
*p = c + 5;
*state = INT_TO_PTR(STATE_VALUE_POST);
return JSON_BOOLEAN;
} else if (startswith(c, "null")) {
*ret_string = NULL;
*ret_value = JSON_VALUE_NULL;
*p = c + 4;
*state = INT_TO_PTR(STATE_VALUE_POST);
return JSON_NULL;
} else
return -EINVAL;
case STATE_VALUE_POST:
if (*c == ':') {
*ret_string = NULL;
*ret_value = JSON_VALUE_NULL;
*p = c + 1;
*state = INT_TO_PTR(STATE_VALUE);
return JSON_COLON;
} else if (*c == ',') {
*ret_string = NULL;
*ret_value = JSON_VALUE_NULL;
*p = c + 1;
*state = INT_TO_PTR(STATE_VALUE);
return JSON_COMMA;
} else if (*c == '}') {
*ret_string = NULL;
*ret_value = JSON_VALUE_NULL;
*p = c + 1;
*state = INT_TO_PTR(STATE_VALUE_POST);
return JSON_OBJECT_CLOSE;
} else if (*c == ']') {
*ret_string = NULL;
*ret_value = JSON_VALUE_NULL;
*p = c + 1;
*state = INT_TO_PTR(STATE_VALUE_POST);
return JSON_ARRAY_CLOSE;
} else
return -EINVAL;
}
}
}