blob: cbb98b3661f60f26c9244124ddc99506fdec711b [file] [log] [blame]
/* $OpenBSD: exec.c,v 1.18 2005/08/08 08:05:34 espie 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/param.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <errno.h>
#include <unistd.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <paths.h>
#include <stdarg.h>
#include <alloca.h>
extern char **environ;
int
execl(const char *name, const char *arg, ...)
{
va_list ap;
char **argv;
int n;
va_start(ap, arg);
n = 1;
while (va_arg(ap, char *) != NULL)
n++;
va_end(ap);
argv = alloca((n + 1) * sizeof(*argv));
if (argv == NULL) {
errno = ENOMEM;
return (-1);
}
va_start(ap, arg);
n = 1;
argv[0] = (char *)arg;
while ((argv[n] = va_arg(ap, char *)) != NULL)
n++;
va_end(ap);
return (execve(name, argv, environ));
}
int
execle(const char *name, const char *arg, ...)
{
va_list ap;
char **argv, **envp;
int n;
va_start(ap, arg);
n = 1;
while (va_arg(ap, char *) != NULL)
n++;
va_end(ap);
argv = alloca((n + 1) * sizeof(*argv));
if (argv == NULL) {
errno = ENOMEM;
return (-1);
}
va_start(ap, arg);
n = 1;
argv[0] = (char *)arg;
while ((argv[n] = va_arg(ap, char *)) != NULL)
n++;
envp = va_arg(ap, char **);
va_end(ap);
return (execve(name, argv, envp));
}
int
execlp(const char *name, const char *arg, ...)
{
va_list ap;
char **argv;
int n;
va_start(ap, arg);
n = 1;
while (va_arg(ap, char *) != NULL)
n++;
va_end(ap);
argv = alloca((n + 1) * sizeof(*argv));
if (argv == NULL) {
errno = ENOMEM;
return (-1);
}
va_start(ap, arg);
n = 1;
argv[0] = (char *)arg;
while ((argv[n] = va_arg(ap, char *)) != NULL)
n++;
va_end(ap);
return (execvp(name, argv));
}
int
execv(const char *name, char * const *argv)
{
(void)execve(name, argv, environ);
return (-1);
}
int
execvp(const char *name, char * const *argv)
{
char **memp;
int cnt, lp, ln, len;
char *p;
int eacces = 0;
char *bp, *cur, *path, buf[MAXPATHLEN];
/*
* Do not allow null name
*/
if (name == NULL || *name == '\0') {
errno = ENOENT;
return (-1);
}
/* If it's an absolute or relative path name, it's easy. */
if (strchr(name, '/')) {
bp = (char *)name;
cur = path = NULL;
goto retry;
}
bp = buf;
/* Get the path we're searching. */
if (!(path = getenv("PATH")))
path = _PATH_DEFPATH;
len = strlen(path) + 1;
cur = alloca(len);
if (cur == NULL) {
errno = ENOMEM;
return (-1);
}
strlcpy(cur, path, len);
path = cur;
while ((p = strsep(&cur, ":"))) {
/*
* It's a SHELL path -- double, leading and trailing colons
* mean the current directory.
*/
if (!*p) {
p = ".";
lp = 1;
} else
lp = strlen(p);
ln = strlen(name);
/*
* 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 > (int)sizeof(buf)) {
struct iovec iov[3];
iov[0].iov_base = "execvp: ";
iov[0].iov_len = 8;
iov[1].iov_base = p;
iov[1].iov_len = lp;
iov[2].iov_base = ": path too long\n";
iov[2].iov_len = 16;
(void)writev(STDERR_FILENO, iov, 3);
continue;
}
bcopy(p, buf, lp);
buf[lp] = '/';
bcopy(name, buf + lp + 1, ln);
buf[lp + ln + 1] = '\0';
retry: (void)execve(bp, argv, environ);
switch(errno) {
case E2BIG:
goto done;
case EISDIR:
case ELOOP:
case ENAMETOOLONG:
case ENOENT:
break;
case ENOEXEC:
for (cnt = 0; argv[cnt]; ++cnt)
;
memp = alloca((cnt + 2) * sizeof(char *));
if (memp == NULL)
goto done;
memp[0] = "sh";
memp[1] = bp;
bcopy(argv + 1, memp + 2, cnt * sizeof(char *));
(void)execve(_PATH_BSHELL, memp, environ);
goto done;
case ENOMEM:
goto done;
case ENOTDIR:
break;
case ETXTBSY:
/*
* We used to retry here, but sh(1) doesn't.
*/
goto done;
case EACCES:
eacces = 1;
break;
default:
goto done;
}
}
if (eacces)
errno = EACCES;
else if (!errno)
errno = ENOENT;
done:
return (-1);
}