source: mainline/uspace/lib/posix/source/sys/stat.c@ 10de842

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 10de842 was 59f388a, checked in by Jakub Jermar <jakub@…>, 8 years ago

Fail legacy interfaces if the position is too large for them to represent

HelenOS interfaces support unsigned 64-bit file sizes and offsets. This
is in contrast with C99-ish and POSIX-ish interfaces in libc and libposix.
The legacy API emulation internally uses the native unsigned 64-bit file
sizes and positions and so it may happen that a returned file size or
offset are bigger than the legacy interface can represent. We choose
to report failure in such a case in order to avoid returning wrong
results.

  • Property mode set to 100644
File size: 4.6 KB
Line 
1/*
2 * Copyright (c) 2011 Jiri Zarevucky
3 * Copyright (c) 2011 Petr Koupy
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * - Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * - Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * - The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30/** @addtogroup libposix
31 * @{
32 */
33/** @file File status handling.
34 */
35
36#define LIBPOSIX_INTERNAL
37#define __POSIX_DEF__(x) posix_##x
38
39#include "../internal/common.h"
40#include "posix/sys/stat.h"
41#include "libc/vfs/vfs.h"
42
43#include "posix/errno.h"
44#include "libc/mem.h"
45
46/**
47 * Convert HelenOS stat struct into POSIX stat struct (if possible).
48 *
49 * @param dest POSIX stat struct.
50 * @param src HelenOS stat struct.
51 *
52 * @return 0 on success, -1 on error.
53 */
54static int stat_to_posix(struct posix_stat *dest, struct stat *src)
55{
56 memset(dest, 0, sizeof(struct posix_stat));
57
58 dest->st_dev = src->service;
59 dest->st_ino = src->index;
60
61 /* HelenOS doesn't support permissions, so we set them all */
62 dest->st_mode = S_IRWXU | S_IRWXG | S_IRWXO;
63 if (src->is_file) {
64 dest->st_mode |= S_IFREG;
65 }
66 if (src->is_directory) {
67 dest->st_mode |= S_IFDIR;
68 }
69
70 dest->st_nlink = src->lnkcnt;
71 dest->st_size = src->size;
72
73 if (src->size > INT64_MAX) {
74 errno = ERANGE;
75 return -1;
76 }
77
78 return 0;
79}
80
81/**
82 * Retrieve file status for file associated with file descriptor.
83 *
84 * @param fd File descriptor of the opened file.
85 * @param st Status structure to be filled with information.
86 * @return Zero on success, -1 otherwise.
87 */
88int posix_fstat(int fd, struct posix_stat *st)
89{
90 struct stat hst;
91 int rc = rcerrno(vfs_stat, fd, &hst);
92 if (rc < 0)
93 return -1;
94 return stat_to_posix(st, &hst);
95}
96
97/**
98 * Retrieve file status for symbolic link.
99 *
100 * @param path Path to the symbolic link.
101 * @param st Status structure to be filled with information.
102 * @return Zero on success, -1 otherwise.
103 */
104int posix_lstat(const char *restrict path, struct posix_stat *restrict st)
105{
106 /* There are currently no symbolic links in HelenOS. */
107 return posix_stat(path, st);
108}
109
110/**
111 * Retrieve file status for regular file (or symbolic link target).
112 *
113 * @param path Path to the file/link.
114 * @param st Status structure to be filled with information.
115 * @return Zero on success, -1 otherwise.
116 */
117int posix_stat(const char *restrict path, struct posix_stat *restrict st)
118{
119 struct stat hst;
120 int rc = rcerrno(vfs_stat_path, path, &hst);
121 if (rc < 0)
122 return -1;
123 return stat_to_posix(st, &hst);
124}
125
126/**
127 * Change permission bits for the file if possible.
128 *
129 * @param path Path to the file.
130 * @param mode Permission bits to be set.
131 * @return Zero on success, -1 otherwise.
132 */
133int posix_chmod(const char *path, posix_mode_t mode)
134{
135 /* HelenOS doesn't support permissions, return success. */
136 return 0;
137}
138
139/**
140 * Set the file mode creation mask of the process.
141 *
142 * @param mask Set permission bits are cleared in the related creation
143 * functions. Non-permission bits are ignored.
144 * @return Previous file mode creation mask.
145 */
146posix_mode_t posix_umask(posix_mode_t mask)
147{
148 /* HelenOS doesn't support permissions, return empty mask. */
149 return 0;
150}
151
152/**
153 * Create a directory.
154 *
155 * @param path Path to the new directory.
156 * @param mode Permission bits to be set.
157 * @return Zero on success, -1 otherwise.
158 */
159int posix_mkdir(const char *path, posix_mode_t mode)
160{
161 int rc = rcerrno(vfs_link_path, path, KIND_DIRECTORY, NULL);
162 if (rc != EOK)
163 return -1;
164 else
165 return 0;
166}
167
168/** @}
169 */
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