util.c revision 1.36 
1/*	$OpenBSD: util.c,v 1.36 2014/12/09 15:36:36 tedu 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 "archdep.h"
32
33/*
34 * Stack protector dummies.
35 * Ideally, a scheme to compile these stubs from libc should be used, but
36 * this would end up dragging too much code from libc here.
37 */
38long __guard_local __dso_hidden __attribute__((section(".openbsd.randomdata")));
39
40void __stack_smash_handler(char [], int);
41
42void
43__stack_smash_handler(char func[], int damaged)
44{
45	extern const char *_dl_progname;
46	char message[100];
47
48	/* <10> indicates LOG_CRIT */
49	_dl_strlcpy(message, "<10>ld.so:", sizeof message);
50	_dl_strlcat(message, _dl_progname, sizeof message);
51	_dl_strlcat(message, "stack overflow in function ", sizeof message);
52	_dl_strlcat(message, func, sizeof message);
53
54	_dl_sendsyslog(message, _dl_strlen(message));
55	_dl_exit(127);
56}
57
58char *
59_dl_strdup(const char *orig)
60{
61	char *newstr;
62	size_t len;
63
64	len = _dl_strlen(orig)+1;
65	newstr = _dl_malloc(len);
66	if (newstr != NULL)
67		_dl_strlcpy(newstr, orig, len);
68	return (newstr);
69}
70
71void
72_dl_randombuf(void *v, size_t buflen)
73{
74	char *buf = v;
75	size_t chunk;
76
77	while (buflen != 0) {
78		if (buflen > 256)
79			chunk = 256;
80		else
81			chunk = buflen;
82		if (_dl_getentropy(buf, chunk) != 0)
83			_dl_exit(8);
84		buflen -= chunk;
85		buf += chunk;
86	}
87}
88
89u_int32_t
90_dl_random(void)
91{
92	u_int32_t rnd;
93	_dl_randombuf(&rnd, sizeof(rnd));
94	return (rnd);
95}
96