Loading...
1/* Parse JSON files using the JSMN parser. */
2
3/*
4 * Copyright (c) 2014, Intel Corporation
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
20 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
21 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
22 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
28 * OF THE POSSIBILITY OF SUCH DAMAGE.
29*/
30
31#include <stdlib.h>
32#include <string.h>
33#include <sys/mman.h>
34#include <sys/stat.h>
35#include <fcntl.h>
36#include <stdio.h>
37#include <errno.h>
38#include <unistd.h>
39#include "jsmn.h"
40#include "json.h"
41#include <linux/kernel.h>
42
43
44static char *mapfile(const char *fn, size_t *size)
45{
46 unsigned ps = sysconf(_SC_PAGESIZE);
47 struct stat st;
48 char *map = NULL;
49 int err;
50 int fd = open(fn, O_RDONLY);
51
52 if (fd < 0 && verbose > 0 && fn) {
53 pr_err("Error opening events file '%s': %s\n", fn,
54 strerror(errno));
55 }
56
57 if (fd < 0)
58 return NULL;
59 err = fstat(fd, &st);
60 if (err < 0)
61 goto out;
62 *size = st.st_size;
63 map = mmap(NULL,
64 (st.st_size + ps - 1) & ~(ps - 1),
65 PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
66 if (map == MAP_FAILED)
67 map = NULL;
68out:
69 close(fd);
70 return map;
71}
72
73static void unmapfile(char *map, size_t size)
74{
75 unsigned ps = sysconf(_SC_PAGESIZE);
76 munmap(map, roundup(size, ps));
77}
78
79/*
80 * Parse json file using jsmn. Return array of tokens,
81 * and mapped file. Caller needs to free array.
82 */
83jsmntok_t *parse_json(const char *fn, char **map, size_t *size, int *len)
84{
85 jsmn_parser parser;
86 jsmntok_t *tokens;
87 jsmnerr_t res;
88 unsigned sz;
89
90 *map = mapfile(fn, size);
91 if (!*map)
92 return NULL;
93 /* Heuristic */
94 sz = *size * 16;
95 tokens = malloc(sz);
96 if (!tokens)
97 goto error;
98 jsmn_init(&parser);
99 res = jsmn_parse(&parser, *map, *size, tokens,
100 sz / sizeof(jsmntok_t));
101 if (res != JSMN_SUCCESS) {
102 pr_err("%s: json error %s\n", fn, jsmn_strerror(res));
103 goto error_free;
104 }
105 if (len)
106 *len = parser.toknext;
107 return tokens;
108error_free:
109 free(tokens);
110error:
111 unmapfile(*map, *size);
112 return NULL;
113}
114
115void free_json(char *map, size_t size, jsmntok_t *tokens)
116{
117 free(tokens);
118 unmapfile(map, size);
119}
120
121static int countchar(char *map, char c, int end)
122{
123 int i;
124 int count = 0;
125 for (i = 0; i < end; i++)
126 if (map[i] == c)
127 count++;
128 return count;
129}
130
131/* Return line number of a jsmn token */
132int json_line(char *map, jsmntok_t *t)
133{
134 return countchar(map, '\n', t->start) + 1;
135}
136
137static const char * const jsmn_types[] = {
138 [JSMN_PRIMITIVE] = "primitive",
139 [JSMN_ARRAY] = "array",
140 [JSMN_OBJECT] = "object",
141 [JSMN_STRING] = "string"
142};
143
144#define LOOKUP(a, i) ((i) < (sizeof(a)/sizeof(*(a))) ? ((a)[i]) : "?")
145
146/* Return type name of a jsmn token */
147const char *json_name(jsmntok_t *t)
148{
149 return LOOKUP(jsmn_types, t->type);
150}
151
152int json_len(jsmntok_t *t)
153{
154 return t->end - t->start;
155}
156
157/* Is string t equal to s? */
158int json_streq(char *map, jsmntok_t *t, const char *s)
159{
160 unsigned len = json_len(t);
161 return len == strlen(s) && !strncasecmp(map + t->start, s, len);
162}
1/* Parse JSON files using the JSMN parser. */
2
3/*
4 * Copyright (c) 2014, Intel Corporation
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
20 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
21 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
22 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
28 * OF THE POSSIBILITY OF SUCH DAMAGE.
29*/
30
31#include <stdlib.h>
32#include <string.h>
33#include <sys/mman.h>
34#include <sys/stat.h>
35#include <fcntl.h>
36#include <stdio.h>
37#include <errno.h>
38#include <unistd.h>
39#include "jsmn.h"
40#include "json.h"
41#include <linux/kernel.h>
42
43
44static char *mapfile(const char *fn, size_t *size)
45{
46 unsigned ps = sysconf(_SC_PAGESIZE);
47 struct stat st;
48 char *map = NULL;
49 int err;
50 int fd = open(fn, O_RDONLY);
51
52 if (fd < 0 && verbose > 0 && fn) {
53 pr_err("Error opening events file '%s': %s\n", fn,
54 strerror(errno));
55 }
56
57 if (fd < 0)
58 return NULL;
59 err = fstat(fd, &st);
60 if (err < 0)
61 goto out;
62 *size = st.st_size;
63 map = mmap(NULL,
64 (st.st_size + ps - 1) & ~(ps - 1),
65 PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
66 if (map == MAP_FAILED)
67 map = NULL;
68out:
69 close(fd);
70 return map;
71}
72
73static void unmapfile(char *map, size_t size)
74{
75 unsigned ps = sysconf(_SC_PAGESIZE);
76 munmap(map, roundup(size, ps));
77}
78
79/*
80 * Parse json file using jsmn. Return array of tokens,
81 * and mapped file. Caller needs to free array.
82 */
83jsmntok_t *parse_json(const char *fn, char **map, size_t *size, int *len)
84{
85 jsmn_parser parser;
86 jsmntok_t *tokens;
87 jsmnerr_t res;
88 unsigned sz;
89
90 *map = mapfile(fn, size);
91 if (!*map)
92 return NULL;
93 /* Heuristic */
94 sz = *size * 16;
95 tokens = malloc(sz);
96 if (!tokens)
97 goto error;
98 jsmn_init(&parser);
99 res = jsmn_parse(&parser, *map, *size, tokens,
100 sz / sizeof(jsmntok_t));
101 if (res != JSMN_SUCCESS) {
102 pr_err("%s: json error %s\n", fn, jsmn_strerror(res));
103 goto error_free;
104 }
105 if (len)
106 *len = parser.toknext;
107 return tokens;
108error_free:
109 free(tokens);
110error:
111 unmapfile(*map, *size);
112 return NULL;
113}
114
115void free_json(char *map, size_t size, jsmntok_t *tokens)
116{
117 free(tokens);
118 unmapfile(map, size);
119}
120
121static int countchar(char *map, char c, int end)
122{
123 int i;
124 int count = 0;
125 for (i = 0; i < end; i++)
126 if (map[i] == c)
127 count++;
128 return count;
129}
130
131/* Return line number of a jsmn token */
132int json_line(char *map, jsmntok_t *t)
133{
134 return countchar(map, '\n', t->start) + 1;
135}
136
137static const char * const jsmn_types[] = {
138 [JSMN_PRIMITIVE] = "primitive",
139 [JSMN_ARRAY] = "array",
140 [JSMN_OBJECT] = "object",
141 [JSMN_STRING] = "string"
142};
143
144#define LOOKUP(a, i) ((i) < (sizeof(a)/sizeof(*(a))) ? ((a)[i]) : "?")
145
146/* Return type name of a jsmn token */
147const char *json_name(jsmntok_t *t)
148{
149 return LOOKUP(jsmn_types, t->type);
150}
151
152int json_len(jsmntok_t *t)
153{
154 return t->end - t->start;
155}
156
157/* Is string t equal to s? */
158int json_streq(char *map, jsmntok_t *t, const char *s)
159{
160 unsigned len = json_len(t);
161 return len == strlen(s) && !strncasecmp(map + t->start, s, len);
162}