NetBSD/libexec/ld.elf_so/expand.c

173 lines
4.1 KiB
C

/* $NetBSD: expand.c,v 1.5 2008/04/28 20:23:03 martin Exp $ */
/*-
* Copyright (c) 2007 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: expand.c,v 1.5 2008/04/28 20:23:03 martin Exp $");
#endif /* not lint */
#include <ctype.h>
#include <string.h>
#include <sys/sysctl.h>
#ifdef DEBUG_EXPAND
#include <stdio.h>
#include <err.h>
#define xwarn warn
#define xerr err
size_t _rtld_expand_path(char *, size_t, const char *, const char *,
const char *);
#else
#include <sys/stat.h>
#include "rtld.h"
#endif
static const struct {
const char *name;
size_t namelen;
} bltn[] = {
#define ADD(a) { #a, sizeof(#a) - 1 },
ADD(HWCAP) /* SSE, MMX, etc */
ADD(ISALIST) /* XXX */
ADD(ORIGIN) /* dirname argv[0] */
ADD(OSNAME) /* uname -s */
ADD(OSREL) /* uname -r */
ADD(PLATFORM) /* uname -p */
};
static int mib[3][2] = {
{ CTL_KERN, KERN_OSTYPE },
{ CTL_KERN, KERN_OSRELEASE },
{ CTL_HW, HW_MACHINE_ARCH },
};
static size_t
expand(char *buf, const char *execname, int what, size_t bl)
{
const char *p, *ep;
char *bp = buf;
size_t len;
char name[32];
switch (what) {
case 0: /* HWCAP XXX: Not yet */
case 1: /* ISALIST XXX: Not yet */
return 0;
case 2: /* ORIGIN */
if (execname == NULL)
xerr(1, "execname not specified in AUX vector");
if ((ep = strrchr(p = execname, '/')) == NULL)
xerr(1, "bad execname `%s' in AUX vector", execname);
break;
case 3: /* OSNAME */
case 4: /* OSREL */
case 5: /* PLATFORM */
len = sizeof(name);
if (sysctl(mib[what - 3], 2, name, &len, NULL, 0) == -1) {
xwarn("sysctl");
return 0;
}
ep = (p = name) + len - 1;
break;
default:
return 0;
}
while (p != ep && bl)
*bp++ = *p++, bl--;
return bp - buf;
}
size_t
_rtld_expand_path(char *buf, size_t bufsize, const char *execname,
const char *bp, const char *ep)
{
size_t i, ds = bufsize;
char *dp = buf;
const char *p;
int br;
for (p = bp; p < ep;) {
if (*p == '$') {
br = *++p == '{';
if (br)
p++;
for (i = 0; i < sizeof(bltn) / sizeof(bltn[0]); i++) {
size_t s = bltn[i].namelen;
const char *es = p + s;
if ((br && *es != '}') ||
(!br && (es != ep &&
isalpha((unsigned char)*es))))
continue;
if (strncmp(bltn[i].name, p, s) == 0) {
size_t ls = expand(dp, execname, i, ds);
if (ls >= ds)
return bufsize;
ds -= ls;
dp += ls;
p = es + br;
goto done;
}
}
p -= br + 1;
}
*dp++ = *p++;
ds--;
done:;
}
*dp = '\0';
return dp - buf;
}
#ifdef DEBUG_EXPAND
int
main(int argc, char *argv[])
{
char buf[1024];
size_t i;
for (i = 1; i < argc; i++) {
char *p = argv[i], *ep = argv[i] + strlen(p);
size_t n = _rtld_expand_path(buf, sizeof(buf), argv[0], p, ep);
printf("%s\n", buf);
}
return 0;
}
#endif