Coverage Report

Created: 2025-07-23 08:18

/src/libzip/lib/zip_source_seek.c
Line
Count
Source (jump to first uncovered line)
1
/*
2
  zip_source_seek.c -- seek to offset
3
  Copyright (C) 2014-2022 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 <info@libzip.org>
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 "zipint.h"
36
37
38
ZIP_EXTERN int
39
0
zip_source_seek(zip_source_t *src, zip_int64_t offset, int whence) {
40
0
    zip_source_args_seek_t args;
41
42
0
    if (src->source_closed) {
43
0
        return -1;
44
0
    }
45
0
    if (!ZIP_SOURCE_IS_OPEN_READING(src) || (whence != SEEK_SET && whence != SEEK_CUR && whence != SEEK_END)) {
46
0
        zip_error_set(&src->error, ZIP_ER_INVAL, 0);
47
0
        return -1;
48
0
    }
49
50
0
    args.offset = offset;
51
0
    args.whence = whence;
52
53
0
    if (_zip_source_call(src, &args, sizeof(args), ZIP_SOURCE_SEEK) < 0) {
54
0
        return -1;
55
0
    }
56
57
0
    src->eof = 0;
58
0
    return 0;
59
0
}
60
61
62
zip_int64_t
63
0
zip_source_seek_compute_offset(zip_uint64_t offset, zip_uint64_t length, void *data, zip_uint64_t data_length, zip_error_t *error) {
64
0
    zip_int64_t new_offset;
65
0
    zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, data_length, error);
66
67
0
    if (args == NULL) {
68
0
        return -1;
69
0
    }
70
71
0
    switch (args->whence) {
72
0
    case SEEK_CUR:
73
0
        new_offset = (zip_int64_t)offset + args->offset;
74
0
        break;
75
76
0
    case SEEK_END:
77
0
        new_offset = (zip_int64_t)length + args->offset;
78
0
        break;
79
80
0
    case SEEK_SET:
81
0
        new_offset = args->offset;
82
0
        break;
83
84
0
    default:
85
0
        zip_error_set(error, ZIP_ER_INVAL, 0);
86
0
        return -1;
87
0
    }
88
89
0
    if (new_offset < 0 || (zip_uint64_t)new_offset > length) {
90
0
        zip_error_set(error, ZIP_ER_INVAL, 0);
91
0
        return -1;
92
0
    }
93
94
0
    return new_offset;
95
0
}