xref: /PHP-7.2/ext/zip/lib/zip_file_get_offset.c (revision 0d57c06b)
1 /*
2   zip_file_get_offset.c -- get offset of file data in archive.
3   Copyright (C) 1999-2015 Dieter Baron and Thomas Klausner
4 
5   This file is part of libzip, a library to manipulate ZIP archives.
6   The authors can be contacted at <libzip@nih.at>
7 
8   Redistribution and use in source and binary forms, with or without
9   modification, are permitted provided that the following conditions
10   are met:
11   1. Redistributions of source code must retain the above copyright
12      notice, this list of conditions and the following disclaimer.
13   2. Redistributions in binary form must reproduce the above copyright
14      notice, this list of conditions and the following disclaimer in
15      the documentation and/or other materials provided with the
16      distribution.
17   3. The names of the authors may not be used to endorse or promote
18      products derived from this software without specific prior
19      written permission.
20 
21   THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
22   OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24   ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
25   DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
29   IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30   OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
31   IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33 
34 
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 
41 #include "zipint.h"
42 
43 
44 /* _zip_file_get_offset(za, ze):
45    Returns the offset of the file data for entry ze.
46 
47    On error, fills in za->error and returns 0.
48 */
49 
50 zip_uint64_t
_zip_file_get_offset(const zip_t * za,zip_uint64_t idx,zip_error_t * error)51 _zip_file_get_offset(const zip_t *za, zip_uint64_t idx, zip_error_t *error)
52 {
53     zip_uint64_t offset;
54     zip_int32_t size;
55 
56     offset = za->entry[idx].orig->offset;
57 
58     if (zip_source_seek(za->src, (zip_int64_t)offset, SEEK_SET) < 0) {
59 	_zip_error_set_from_source(error, za->src);
60 	return 0;
61     }
62 
63     /* TODO: cache? */
64     if ((size=_zip_dirent_size(za->src, ZIP_EF_LOCAL, error)) < 0)
65 	return 0;
66 
67     if (offset+(zip_uint32_t)size > ZIP_INT64_MAX) {
68         zip_error_set(error, ZIP_ER_SEEK, EFBIG);
69         return 0;
70     }
71 
72     return offset + (zip_uint32_t)size;
73 }
74