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/* $NetBSD: execvp.c,v 1.31 2014/09/26 19:28:03 christos Exp $ */
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)exec.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: execvp.c,v 1.31 2014/09/26 19:28:03 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <unistd.h>
#include <paths.h>
#include "reentrant.h"
#ifdef __weak_alias
__weak_alias(execvp,_execvp)
__weak_alias(execvpe,_execvpe)
#endif
int
execvpe(const char *name, char * const *argv, char * const * envp)
{
const char **memp;
int cnt;
size_t lp, ln;
int eacces = 0;
unsigned int etxtbsy = 0;
char buf[PATH_MAX];
const char *bp, *path, *p;
_DIAGASSERT(name != NULL);
/* "" is not a valid filename; check this before traversing PATH. */
if (name[0] == '\0') {
errno = ENOENT;
goto done;
}
ln = strlen(name);
/* If it's an absolute or relative path name, it's easy. */
if (strchr(name, '/')) {
bp = name;
path = "";
goto retry;
}
bp = buf;
/* Get the path we're searching. */
if (!(path = getenv("PATH")))
path = _PATH_DEFPATH;
do {
/* Find the end of this path element. */
for (p = path; *path != 0 && *path != ':'; path++)
continue;
/*
* It's a SHELL path -- double, leading and trailing colons
* mean the current directory.
*/
if (p == path) {
p = ".";
lp = 1;
} else
lp = path - p;
/*
* If the path is too long complain. This is a possible
* security issue; given a way to make the path too long
* the user may execute the wrong program.
*/
if (lp + ln + 2 > sizeof(buf)) {
(void)write(STDERR_FILENO, "execvp: ", 8);
(void)write(STDERR_FILENO, p, lp);
(void)write(STDERR_FILENO, ": path too long\n", 16);
continue;
}
memcpy(buf, p, lp);
buf[lp] = '/';
memcpy(buf + lp + 1, name, ln);
buf[lp + ln + 1] = '\0';
retry: (void)execve(bp, argv, envp);
switch (errno) {
case EACCES:
eacces = 1;
break;
case ENOTDIR:
case ENOENT:
break;
case ENOEXEC:
for (cnt = 0; argv[cnt] != NULL; ++cnt)
continue;
/*
* we can't use malloc here because, if we are doing
* vfork+exec, it leaks memory in the parent.
*/
if ((memp = alloca((cnt + 2) * sizeof(*memp))) == NULL)
goto done;
memp[0] = _PATH_BSHELL;
memp[1] = bp;
(void)memcpy(&memp[2], &argv[1], cnt * sizeof(*memp));
(void)execve(_PATH_BSHELL, __UNCONST(memp), envp);
goto done;
case ETXTBSY:
if (etxtbsy < 3)
(void)sleep(++etxtbsy);
goto retry;
default:
goto done;
}
} while (*path++ == ':'); /* Otherwise, *path was NUL */
if (eacces)
errno = EACCES;
else if (!errno)
errno = ENOENT;
done:
return (-1);
}
extern char **environ;
int
execvp(const char *name, char * const *argv)
{
return execvpe(name, argv, environ);
}
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