util.c revision 1.32 
1/*	$OpenBSD: util.c,v 1.32 2014/06/21 08:00:23 otto Exp $	*/
2
3/*
4 * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
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 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 */
28
29#include <sys/types.h>
30#include <sys/param.h>
31#include <sys/sysctl.h>
32#include <string.h>
33#include "archdep.h"
34
35/*
36 * Stack protector dummies.
37 * Ideally, a scheme to compile these stubs from libc should be used, but
38 * this would end up dragging too much code from libc here.
39 */
40long __guard_local __dso_hidden __attribute__((section(".openbsd.randomdata")));
41
42void __stack_smash_handler(char [], int);
43
44void
45__stack_smash_handler(char func[], int damaged)
46{
47	_dl_exit(127);
48}
49
50char *
51_dl_strdup(const char *orig)
52{
53	char *newstr;
54	size_t len;
55
56	len = _dl_strlen(orig)+1;
57	newstr = _dl_malloc(len);
58	if (newstr != NULL)
59		_dl_strlcpy(newstr, orig, len);
60	return (newstr);
61}
62
63void
64_dl_randombuf(void *buf, size_t buflen)
65{
66	const int mib[2] = { CTL_KERN, KERN_ARND };
67	size_t chunk;
68
69	while (buflen != 0) {
70		if (buflen > 256)
71			chunk = 256;
72		else
73			chunk = buflen;
74		_dl_sysctl(mib, 2, buf, &chunk, NULL, 0);
75		buflen -= chunk;
76		buf += chunk;
77	}
78}
79
80u_int32_t
81_dl_random(void)
82{
83	u_int32_t rnd;
84	_dl_randombuf(&rnd, sizeof(rnd));
85	return (rnd);
86}
87