util.c revision 1.16 
1/*	$OpenBSD: util.c,v 1.16 2003/07/06 20:03:58 deraadt 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/mman.h>
32#include <sys/sysctl.h>
33#include <string.h>
34#include "archdep.h"
35
36/*
37 * Stack protector dummies.
38 * Ideally, a scheme to compile these stubs from libc should be used, but
39 * this would end up dragging too much code from libc here.
40 */
41long __guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
42
43void __stack_smash_handler(char [], int);
44
45void
46__stack_smash_handler(char func[], int damaged)
47{
48	_dl_exit(127);
49}
50
51/*
52 * Static vars usable after bootstrapping.
53 */
54static void *_dl_malloc_base;
55static void *_dl_malloc_pool = 0;
56static long *_dl_malloc_free = 0;
57
58char *
59_dl_strdup(const char *orig)
60{
61	char *newstr;
62	int len;
63
64	len = _dl_strlen(orig)+1;
65	newstr = _dl_malloc(len);
66	_dl_strlcpy(newstr, orig, len);
67	return (newstr);
68}
69
70/*
71 * The following malloc/free code is a very simplified implementation
72 * of a malloc function. However, we do not need to be very complex here
73 * because we only free memory when 'dlclose()' is called and we can
74 * reuse at least the memory allocated for the object descriptor. We have
75 * one dynamic string allocated, the library name and it is likely that
76 * we can reuse that one to without a lot of complex colapsing code.
77 */
78void *
79_dl_malloc(size_t size)
80{
81	long *p, *t, *n;
82
83	size = (size + 8 + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1);
84
85	if ((t = _dl_malloc_free) != 0) {	/* Try free list first */
86		n = (long *)&_dl_malloc_free;
87		while (t && t[-1] < size) {
88			n = t;
89			t = (long *)*t;
90		}
91		if (t) {
92			*n = *t;
93			_dl_memset(t, 0, t[-1] - 4);
94			return((void *)t);
95		}
96	}
97	if (_dl_malloc_pool == 0 ||
98	    _dl_malloc_pool + size > _dl_malloc_base + 4096) {
99		_dl_malloc_pool = (void *)_dl_mmap((void *)0, 4096,
100		    PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
101		if (_dl_malloc_pool == 0 || _dl_malloc_pool == MAP_FAILED ) {
102			_dl_printf("Dynamic loader failure: malloc.\n");
103			_dl_exit(7);
104		}
105		_dl_malloc_base = _dl_malloc_pool;
106	}
107	p = _dl_malloc_pool;
108	_dl_malloc_pool += size;
109	_dl_memset(p, 0, size);
110	*p = size;
111	return((void *)(p + 1));
112}
113
114void
115_dl_free(void *p)
116{
117	long *t = (long *)p;
118
119	*t = (long)_dl_malloc_free;
120	_dl_malloc_free = p;
121}
122
123
124unsigned int
125_dl_random(void)
126{
127	int mib[2];
128	unsigned int rnd;
129	size_t len;
130
131	mib[0] = CTL_KERN;
132	mib[1] = KERN_ARND;
133	len = sizeof(rnd);
134	_dl_sysctl(mib, 2, &rnd, &len, NULL, 0);
135
136	return (rnd);
137}
138
139
140