xref: /freebsd/contrib/elftoolchain/libpe/libpe_utils.c (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1 /*-
2  * Copyright (c) 2016 Kai Wang
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/param.h>
28 #include <assert.h>
29 #include <errno.h>
30 #include <string.h>
31 #include <unistd.h>
32 
33 #include "_libpe.h"
34 
35 ELFTC_VCSID("$Id: libpe_utils.c 3312 2016-01-10 09:23:51Z kaiwang27 $");
36 
37 off_t
38 libpe_align(PE *pe, off_t off, size_t align)
39 {
40 	off_t n;
41 
42 	assert(align > 0 && (align & (align - 1)) == 0);
43 
44 	n = roundup(off, align);
45 	if (n > off) {
46 		if (libpe_pad(pe, n - off) < 0)
47 			return (-1);
48 	}
49 
50 	return (n);
51 }
52 
53 int
54 libpe_pad(PE *pe, size_t pad)
55 {
56 	char tmp[128];
57 	size_t s;
58 
59 	memset(tmp, 0, sizeof(tmp));
60 	for (; pad > 0; pad -= s) {
61 		s = pad > sizeof(tmp) ? sizeof(tmp) : pad;
62 		if (write(pe->pe_fd, tmp, s) != (ssize_t) s) {
63 			errno = EIO;
64 			return (-1);
65 		}
66 	}
67 
68 	return (0);
69 }
70