wireshark/wiretap/mp4.c

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/* mp4.c
*
* MP4 (ISO/IEC 14496-12) file format decoder for the Wiretap library.
*
* Wiretap Library
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "mp4.h"
#include <string.h>
#include "file_wrappers.h"
#include "wtap-int.h"
static const guint8 mp4_magic[] = { 'f', 't', 'y', 'p' };
static const guint8 mp4_magic_sidx[] = { 's', 'i', 'd', 'x' };
static const guint8 mp4_magic_styp[] = { 's', 't', 'y', 'p' };
static int mp4_file_type_subtype = -1;
void register_mp4(void);
wtap_open_return_val
mp4_open(wtap *wth, int *err, gchar **err_info)
{
char magic_buf[8];
int bytes_read;
bytes_read = file_read(magic_buf, sizeof (magic_buf), wth->fh);
if (bytes_read < 0) {
*err = file_error(wth->fh, err_info);
return WTAP_OPEN_ERROR;
}
if (bytes_read == 0)
return WTAP_OPEN_NOT_MINE;
if (bytes_read == sizeof (magic_buf) &&
memcmp(magic_buf + 4, mp4_magic, sizeof (mp4_magic)) &&
memcmp(magic_buf + 4, mp4_magic_sidx, sizeof (mp4_magic_sidx)) &&
memcmp(magic_buf + 4, mp4_magic_styp, sizeof (mp4_magic_styp)))
return WTAP_OPEN_NOT_MINE;
if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
return WTAP_OPEN_ERROR;
wth->file_type_subtype = mp4_file_type_subtype;
wth->file_encap = WTAP_ENCAP_MP4;
wth->file_tsprec = WTAP_TSPREC_SEC;
wth->subtype_read = wtap_full_file_read;
wth->subtype_seek_read = wtap_full_file_seek_read;
wth->snapshot_length = 0;
return WTAP_OPEN_MINE;
}
static const struct supported_block_type mp4_blocks_supported[] = {
/*
* This is a file format that we dissect, so we provide
* only one "packet" with the file's contents, and don't
* support any options.
*/
{ WTAP_BLOCK_PACKET, ONE_BLOCK_SUPPORTED, NO_OPTIONS_SUPPORTED }
};
static const struct file_type_subtype_info mp4_info = {
"MP4 media", "mp4", "mp4", NULL,
FALSE, BLOCKS_SUPPORTED(mp4_blocks_supported),
NULL, NULL, NULL
};
void register_mp4(void)
{
mp4_file_type_subtype = wtap_register_file_type_subtype(&mp4_info);
wiretap: more work on file type/subtypes. Provide a wiretap routine to get an array of all savable file type/subtypes, sorted with pcap and pcapng at the top, followed by the other types, sorted either by the name or the description. Use that routine to list options for the -F flag for various commands Rename wtap_get_savable_file_types_subtypes() to wtap_get_savable_file_types_subtypes_for_file(), to indicate that it provides an array of all file type/subtypes in which a given file can be saved. Have it sort all types, other than the default type/subtype and, if there is one, the "other" type (both of which are put at the top), by the name or the description. Don't allow wtap_register_file_type_subtypes() to override any existing registrations; have them always register a new type. In that routine, if there are any emply slots in the table, due to an entry being unregistered, use it rather than allocating a new slot. Don't allow unregistration of built-in types. Rename the "dump open table" to the "file type/subtype table", as it has entries for all types/subtypes, even if we can't write them. Initialize that table in a routine that pre-allocates the GArray before filling it with built-in types/subtypes, so it doesn't keep getting reallocated. Get rid of wtap_num_file_types_subtypes - it's just a copy of the size of the GArray. Don't have wtap_file_type_subtype_description() crash if handed an file type/subtype that isn't a valid array index - just return NULL, as we do with wtap_file_type_subtype_name(). In wtap_name_to_file_type_subtype(), don't use WTAP_FILE_TYPE_SUBTYPE_ names for the backwards-compatibility names - map those names to the current names, and then look them up. This reduces the number of uses of hardwired WTAP_FILE_TYPE_SUBTYPE_ values. Clean up the type of wtap_module_count - it has no need to be a gulong. Have built-in wiretap file handlers register names to be used for their file type/subtypes, rather than building the table in init.lua. Add a new Lua C function get_wtap_filetypes() to construct the wtap_filetypes table, based on the registered names, and use it in init.lua. Add a #define WSLUA_INTERNAL_FUNCTION to register functions intended only for internal use in init.lua, so they can be made available from Lua without being documented. Get rid of WTAP_NUM_FILE_TYPES_SUBTYPES - most code has no need to use it, as it can just request arrays of types, and the space of type/subtype codes can be sparse due to registration in any case, so code has to be careful using it. wtap_get_num_file_types_subtypes() is no longer used, so remove it. It returns the number of elements in the file type/subtype array, which is not necessarily the name of known file type/subtypes, as there may have been some deregistered types, and those types do *not* get removed from the array, they just get cleared so that they're available for future allocation (we don't want the indices of any registered types to changes if another type is deregistered, as those indicates are the type/subtype values, so we can't shrink the array). Clean up white space and remove some comments that shouldn't have been added.
2021-02-17 06:24:47 +00:00
/*
* Register name for backwards compatibility with the
* wtap_filetypes table in Lua.
*/
wtap_register_backwards_compatibility_lua_name("MP4",
mp4_file_type_subtype);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/