Coverage Report

Created: 2025-04-03 08:45

/src/wireshark/wiretap/json.c
Line
Count
Source (jump to first uncovered line)
1
/* json.c
2
 *
3
 * Copyright 2015, Dario Lombardo <lomato@gmail.com>
4
 *
5
 * SPDX-License-Identifier: GPL-2.0-or-later
6
 */
7
8
#include "config.h"
9
#include "json.h"
10
11
#include <string.h>
12
13
#include "wtap-int.h"
14
#include "file_wrappers.h"
15
16
#include <wsutil/wsjson.h>
17
18
/* Maximum size of json file. */
19
0
#define MAX_FILE_SIZE  (50*1024*1024)
20
21
static int json_file_type_subtype = -1;
22
23
void register_json(void);
24
25
wtap_open_return_val json_open(wtap *wth, int *err, char **err_info)
26
0
{
27
0
    uint8_t* filebuf;
28
0
    int bytes_read;
29
30
    /* XXX checking the full file contents might be a bit expensive, maybe
31
     * resort to simpler heuristics like '{' or '[' (with some other chars)? */
32
0
    filebuf = (uint8_t*)g_malloc0(MAX_FILE_SIZE);
33
0
    if (!filebuf)
34
0
        return WTAP_OPEN_ERROR;
35
36
0
    bytes_read = file_read(filebuf, MAX_FILE_SIZE, wth->fh);
37
0
    if (bytes_read < 0) {
38
        /* Read error. */
39
0
        *err = file_error(wth->fh, err_info);
40
0
        g_free(filebuf);
41
0
        return WTAP_OPEN_ERROR;
42
0
    }
43
0
    if (bytes_read == 0) {
44
        /* empty file, not *anybody's* */
45
0
        g_free(filebuf);
46
0
        return WTAP_OPEN_NOT_MINE;
47
0
    }
48
49
    /* We could reduce the maximum size to read and accept if the parser
50
     * returns JSMN_ERROR_PART (i.e., only fail on JSMN_ERROR_INVAL as we
51
     * shouldn't get JSMN_ERROR_NOMEM if tokens is NULL.) That way we
52
     * could handle bigger files without testing the entire file.
53
     * packet-json shows excess unparsed data at the end with the
54
     * data-text-lines dissector.
55
     */
56
0
    if (json_parse_len(filebuf, bytes_read, NULL, 0) < 0) {
57
0
        g_free(filebuf);
58
0
        return WTAP_OPEN_NOT_MINE;
59
0
    }
60
61
0
    if (file_seek(wth->fh, 0, SEEK_SET, err) == -1) {
62
0
        g_free(filebuf);
63
0
        return WTAP_OPEN_ERROR;
64
0
    }
65
66
0
    wth->file_type_subtype = json_file_type_subtype;
67
0
    wth->file_encap = WTAP_ENCAP_JSON;
68
0
    wth->file_tsprec = WTAP_TSPREC_SEC;
69
0
    wth->subtype_read = wtap_full_file_read;
70
0
    wth->subtype_seek_read = wtap_full_file_seek_read;
71
0
    wth->snapshot_length = 0;
72
73
0
    g_free(filebuf);
74
0
    return WTAP_OPEN_MINE;
75
0
}
76
77
static const struct supported_block_type json_blocks_supported[] = {
78
    /*
79
     * This is a file format that we dissect, so we provide only one
80
     * "packet" with the file's contents, and don't support any
81
     * options.
82
     */
83
    { WTAP_BLOCK_PACKET, ONE_BLOCK_SUPPORTED, NO_OPTIONS_SUPPORTED }
84
};
85
86
static const struct file_type_subtype_info json_info = {
87
    "JavaScript Object Notation", "json", "json", NULL,
88
    false, BLOCKS_SUPPORTED(json_blocks_supported),
89
    NULL, NULL, NULL
90
};
91
92
void register_json(void)
93
8
{
94
8
    json_file_type_subtype = wtap_register_file_type_subtype(&json_info);
95
96
    /*
97
     * Register name for backwards compatibility with the
98
     * wtap_filetypes table in Lua.
99
     */
100
8
    wtap_register_backwards_compatibility_lua_name("JSON",
101
8
                                                   json_file_type_subtype);
102
8
}
103
104
/*
105
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
106
 *
107
 * Local variables:
108
 * c-basic-offset: 4
109
 * tab-width: 8
110
 * indent-tabs-mode: nil
111
 * End:
112
 *
113
 * vi: set shiftwidth=4 tabstop=8 expandtab:
114
 * :indentSize=4:tabSize=8:noTabs=true:
115
 */