pd-mapper/json.c
Jeremy Linton 10997ba7c4 pd-mapper: Add ability to decompress .xz json files
Many distros and ship Linux firmware in compressed form.
In the case of fedora that is .xz format, so lets add the
ability for pd-mapper to understand LZMA compressed JSON files.

Signed-off-by: Jeremy Linton <lintonrjeremy@gmail.com>
2023-09-01 09:55:20 -05:00

459 lines
8.1 KiB
C

/*
* Copyright (c) 2018-2019, Linaro Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/stat.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <lzma.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "json.h"
static const char *input_buf;
static int input_pos;
static int input_len;
static int json_parse_array(struct json_value *array);
static int json_parse_object(struct json_value *object);
static int json_parse_property(struct json_value *value);
static int input(void)
{
if (input_pos >= input_len)
return 0;
return input_buf[input_pos++];
}
static void unput(void)
{
input_pos--;
}
static void json_skip_whitespace(void)
{
int ch;
while ((ch = input()) && isspace(ch))
;
unput();
}
static int json_parse_string(struct json_value *value)
{
char buf[128];
char *b = buf;
int ch;
ch = input();
if (ch != '"') {
unput();
return 0;
}
while ((ch = input()) && ch != '"' && b - buf < sizeof(buf) - 1)
*b++ = ch;
*b = '\0';
if (!ch)
return -1;
value->type = JSON_TYPE_STRING;
value->u.string = strdup(buf);
return 1;
}
static int json_parse_number(struct json_value *value)
{
char buf[20];
char *b = buf;
int ch;
while ((ch = input()) && isdigit(ch) && b - buf < sizeof(buf) - 1)
*b++ = ch;
*b = '\0';
unput();
if (b == buf)
return 0;
value->type = JSON_TYPE_NUMBER;
value->u.number = strtod(buf, NULL);
return 1;
}
static int json_parse_keyword(struct json_value *value)
{
const char *match;
const char *m;
int ch;
ch = input();
switch (ch) {
case 't':
match = "true";
value->type = JSON_TYPE_TRUE;
break;
case 'f':
match = "false";
value->type = JSON_TYPE_FALSE;
break;
case 'n':
match = "null";
value->type = JSON_TYPE_NULL;
break;
default:
unput();
return 0;
}
m = match;
while (*m && *m++ == ch)
ch = input();
unput();
return *m == '\0' ? 1 : -1;
}
static int json_parse_value(struct json_value *value)
{
int ret;
json_skip_whitespace();
ret = json_parse_object(value);
if (ret)
goto out;
ret = json_parse_array(value);
if (ret)
goto out;
ret = json_parse_string(value);
if (ret)
goto out;
ret = json_parse_number(value);
if (ret)
goto out;
ret = json_parse_keyword(value);
if (ret)
goto out;
fprintf(stderr, "unable to match a value\n");
return -1;
out:
json_skip_whitespace();
return ret;
}
static int json_parse_array(struct json_value *array)
{
struct json_value *value;
struct json_value *last = NULL;
int ret;
int ch;
ch = input();
if (ch != '[') {
unput();
return 0;
}
array->type = JSON_TYPE_ARRAY;
do {
value = calloc(1, sizeof(*value));
if (!value)
return -1;
ret = json_parse_value(value);
if (ret <= 0) {
free(value);
return -1;
}
if (!array->u.value)
array->u.value = value;
if (last)
last->next = value;
last = value;
ch = input();
if (ch == ']') {
return 1;
}
} while (ch == ',');
fprintf(stderr, "expected ',' got '%c'\n", ch);
return -1;
}
static int json_parse_object(struct json_value *object)
{
struct json_value *value;
struct json_value *last = NULL;
int ret;
int ch;
ch = input();
if (ch != '{') {
unput();
return 0;
}
object->type = JSON_TYPE_OBJECT;
do {
value = calloc(1, sizeof(*value));
if (!value)
return -1;
ret = json_parse_property(value);
if (ret <= 0) {
free(value);
return -1;
}
if (!object->u.value)
object->u.value = value;
if (last)
last->next = value;
last = value;
ch = input();
if (ch == '}') {
return 1;
}
} while (ch == ',');
return -1;
}
static int json_parse_property(struct json_value *value)
{
struct json_value key;
int ret;
int ch;
json_skip_whitespace();
ret = json_parse_string(&key);
if (ret <= 0)
return -1;
value->key = key.u.string;
json_skip_whitespace();
ch = input();
if (ch != ':')
return -1;
ret = json_parse_value(value);
if (ret <= 0)
return -1;
return 1;
}
struct json_value *json_parse(const char *json)
{
struct json_value *root;
int ret;
input_buf = json;
input_pos = 0;
input_len = strlen(input_buf);
root = calloc(1, sizeof(*root));
if (!root)
return NULL;
ret = json_parse_value(root);
if (ret != 1) {
free(root);
return NULL;
}
return root;
}
extern int lzma_decomp(const char *file);
struct json_value *json_parse_file(const char *file)
{
struct json_value *root;
struct stat sb;
int ret;
int fd;
if ((strlen(file) > 3) && !strcmp(&file[strlen(file)-3], ".xz"))
fd = lzma_decomp(file);
else
fd = open(file, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "failed to open %s: %s\n", file, strerror(errno));
return NULL;
}
ret = fstat(fd, &sb);
if (ret < 0)
return NULL;
input_pos = 0;
input_len = sb.st_size;
input_buf = malloc(sb.st_size);
ret = read(fd, (char *)input_buf, input_len);
close(fd);
if (ret != input_len) {
fprintf(stderr, "failed to read %d bytes form %s\n", input_len, file);
return NULL;
}
root = calloc(1, sizeof(*root));
if (!root)
return NULL;
ret = json_parse_value(root);
if (ret != 1) {
json_free(root);
return NULL;
}
return root;
}
struct json_value *json_get_child(struct json_value *object, const char *key)
{
struct json_value *it;
if(object->type != JSON_TYPE_OBJECT)
return NULL;
for (it = object->u.value; it; it = it->next) {
if (!strcmp(it->key, key))
return it;
}
return NULL;
}
int json_count_children(struct json_value *array)
{
struct json_value *it;
int count = 0;
if (!array || array->type != JSON_TYPE_ARRAY)
return -1;
for (it = array->u.value; it; it = it->next)
count++;
return count;
}
int json_get_number(struct json_value *object, const char *key, double *number)
{
struct json_value *it;
if (!object || object->type != JSON_TYPE_OBJECT)
return -1;
for (it = object->u.value; it; it = it->next) {
if (!strcmp(it->key, key)) {
if (it->type != JSON_TYPE_NUMBER)
return -1;
*number = it->u.number;
return 0;
}
}
return -1;
}
const char *json_get_string(struct json_value *object, const char *key)
{
struct json_value *it;
if (!object || object->type != JSON_TYPE_OBJECT)
return NULL;
for (it = object->u.value; it; it = it->next) {
if (!strcmp(it->key, key)) {
if (it->type != JSON_TYPE_STRING)
return NULL;
return it->u.string;
}
}
return NULL;
}
void json_free(struct json_value *value)
{
struct json_value *next;
struct json_value *it;
free((char *)value->key);
switch (value->type) {
case JSON_TYPE_OBJECT:
case JSON_TYPE_ARRAY:
it = value->u.value;
while (it) {
next = it->next;
json_free(it);
it = next;
}
break;
case JSON_TYPE_STRING:
free((char *)value->u.string);
break;
}
free(value);
}