1 /*
2  * SPDX-License-Identifier: ISC
3  *
4  * Copyright (c) 2020 Todd C. Miller <Todd.Miller@sudo.ws>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 /*
20  * This is an open source non-commercial project. Dear PVS-Studio, please check it.
21  * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
22  */
23 
24 #include <config.h>
25 
26 #include <errno.h>
27 #include <unistd.h>
28 
29 #include "sudo_compat.h"
30 
31 #if !defined(HAVE_PWRITE) && !defined(HAVE_PWRITE64)
32 ssize_t
sudo_pwrite(int fd,const void * buf,size_t nbytes,off_t offset)33 sudo_pwrite(int fd, const void *buf, size_t nbytes, off_t offset)
34 {
35     ssize_t nwritten;
36     off_t old_offset;
37 
38     old_offset = lseek(fd, (off_t)0, SEEK_CUR);
39     if (old_offset == -1 || lseek(fd, offset, SEEK_SET) == -1)
40 	return -1;
41 
42     nwritten = write(fd, buf, nbytes);
43     if (lseek(fd, old_offset, SEEK_SET) == -1)
44 	return -1;
45 
46     return nwritten;
47 }
48 #endif /* HAVE_PWRITE && !HAVE_PWRITE64 */
49