1 /* mp4.c
2 *
3 * MP4 (ISO/IEC 14496-12) file format decoder for the Wiretap library.
4 *
5 * Wiretap Library
6 *
7 * SPDX-License-Identifier: GPL-2.0-or-later
8 */
9
10 #include "mp4.h"
11
12 #include <string.h>
13
14 #include "file_wrappers.h"
15 #include "wtap-int.h"
16
17 static const guint8 mp4_magic[] = { 'f', 't', 'y', 'p' };
18
19 static int mp4_file_type_subtype = -1;
20
21 void register_mp4(void);
22
23 wtap_open_return_val
mp4_open(wtap * wth,int * err,gchar ** err_info)24 mp4_open(wtap *wth, int *err, gchar **err_info)
25 {
26 char magic_buf[8];
27 int bytes_read;
28
29 bytes_read = file_read(magic_buf, sizeof (magic_buf), wth->fh);
30
31 if (bytes_read < 0) {
32 *err = file_error(wth->fh, err_info);
33 return WTAP_OPEN_ERROR;
34 }
35 if (bytes_read == 0)
36 return WTAP_OPEN_NOT_MINE;
37
38 if (bytes_read == sizeof (magic_buf) &&
39 memcmp(magic_buf + 4, mp4_magic, sizeof (mp4_magic)))
40 return WTAP_OPEN_NOT_MINE;
41
42 if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
43 return WTAP_OPEN_ERROR;
44
45 wth->file_type_subtype = mp4_file_type_subtype;
46 wth->file_encap = WTAP_ENCAP_MP4;
47 wth->file_tsprec = WTAP_TSPREC_SEC;
48 wth->subtype_read = wtap_full_file_read;
49 wth->subtype_seek_read = wtap_full_file_seek_read;
50 wth->snapshot_length = 0;
51
52 return WTAP_OPEN_MINE;
53 }
54
55 static const struct supported_block_type mp4_blocks_supported[] = {
56 /*
57 * This is a file format that we dissect, so we provide
58 * only one "packet" with the file's contents, and don't
59 * support any options.
60 */
61 { WTAP_BLOCK_PACKET, ONE_BLOCK_SUPPORTED, NO_OPTIONS_SUPPORTED }
62 };
63
64 static const struct file_type_subtype_info mp4_info = {
65 "MP4 media", "mp4", "mp4", NULL,
66 FALSE, BLOCKS_SUPPORTED(mp4_blocks_supported),
67 NULL, NULL, NULL
68 };
69
register_mp4(void)70 void register_mp4(void)
71 {
72 mp4_file_type_subtype = wtap_register_file_type_subtype(&mp4_info);
73
74 /*
75 * Register name for backwards compatibility with the
76 * wtap_filetypes table in Lua.
77 */
78 wtap_register_backwards_compatibility_lua_name("MP4",
79 mp4_file_type_subtype);
80 }
81
82 /*
83 * Editor modelines - https://www.wireshark.org/tools/modelines.html
84 *
85 * Local variables:
86 * c-basic-offset: 8
87 * tab-width: 8
88 * indent-tabs-mode: t
89 * End:
90 *
91 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
92 * :indentSize=8:tabSize=8:noTabs=false:
93 */
94