freebsd-dev/lib/libc/gen/exec.c
Ed Schouten b3608ae18f Replace index() and rindex() calls with strchr() and strrchr().
The index() and rindex() functions were marked LEGACY in the 2001
revision of POSIX and were subsequently removed from the 2008 revision.
The strchr() and strrchr() functions are part of the C standard.

This makes the source code a lot more consistent, as most of these C
files also call into other str*() routines. In fact, about a dozen
already perform strchr() calls.
2012-01-03 18:51:58 +00:00

285 lines
6.4 KiB
C

/*-
* 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.
* 4. 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)exec.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <paths.h>
#include <stdarg.h>
#include "un-namespace.h"
#include "libc_private.h"
extern char **environ;
int
execl(const char *name, const char *arg, ...)
{
va_list ap;
const 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] = arg;
while ((argv[n] = va_arg(ap, char *)) != NULL)
n++;
va_end(ap);
return (_execve(name, __DECONST(char **, argv), environ));
}
int
execle(const char *name, const char *arg, ...)
{
va_list ap;
const char **argv;
char **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] = arg;
while ((argv[n] = va_arg(ap, char *)) != NULL)
n++;
envp = va_arg(ap, char **);
va_end(ap);
return (_execve(name, __DECONST(char **, argv), envp));
}
int
execlp(const char *name, const char *arg, ...)
{
va_list ap;
const 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] = arg;
while ((argv[n] = va_arg(ap, char *)) != NULL)
n++;
va_end(ap);
return (execvp(name, __DECONST(char **, argv)));
}
int
execv(name, argv)
const char *name;
char * const *argv;
{
(void)_execve(name, argv, environ);
return (-1);
}
int
execvp(const char *name, char * const *argv)
{
return (_execvpe(name, argv, environ));
}
static int
execvPe(const char *name, const char *path, char * const *argv,
char * const *envp)
{
const char **memp;
size_t cnt, lp, ln;
int eacces, save_errno;
char *cur, buf[MAXPATHLEN];
const char *p, *bp;
struct stat sb;
eacces = 0;
/* If it's an absolute or relative path name, it's easy. */
if (strchr(name, '/')) {
bp = name;
cur = NULL;
goto retry;
}
bp = buf;
/* If it's an empty path name, fail in the usual POSIX way. */
if (*name == '\0') {
errno = ENOENT;
return (-1);
}
cur = alloca(strlen(path) + 1);
if (cur == NULL) {
errno = ENOMEM;
return (-1);
}
strcpy(cur, path);
while ((p = strsep(&cur, ":")) != NULL) {
/*
* It's a SHELL path -- double, leading and trailing colons
* mean the current directory.
*/
if (*p == '\0') {
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 > sizeof(buf)) {
(void)_write(STDERR_FILENO, "execvP: ", 8);
(void)_write(STDERR_FILENO, p, lp);
(void)_write(STDERR_FILENO, ": path too long\n",
16);
continue;
}
bcopy(p, buf, lp);
buf[lp] = '/';
bcopy(name, buf + lp + 1, ln);
buf[lp + ln + 1] = '\0';
retry: (void)_execve(bp, argv, envp);
switch (errno) {
case E2BIG:
goto done;
case ELOOP:
case ENAMETOOLONG:
case ENOENT:
break;
case ENOEXEC:
for (cnt = 0; argv[cnt]; ++cnt)
;
memp = alloca((cnt + 2) * sizeof(char *));
if (memp == NULL) {
/* errno = ENOMEM; XXX override ENOEXEC? */
goto done;
}
memp[0] = "sh";
memp[1] = bp;
bcopy(argv + 1, memp + 2, cnt * sizeof(char *));
(void)_execve(_PATH_BSHELL,
__DECONST(char **, memp), envp);
goto done;
case ENOMEM:
goto done;
case ENOTDIR:
break;
case ETXTBSY:
/*
* We used to retry here, but sh(1) doesn't.
*/
goto done;
default:
/*
* EACCES may be for an inaccessible directory or
* a non-executable file. Call stat() to decide
* which. This also handles ambiguities for EFAULT
* and EIO, and undocumented errors like ESTALE.
* We hope that the race for a stat() is unimportant.
*/
save_errno = errno;
if (stat(bp, &sb) != 0)
break;
if (save_errno == EACCES) {
eacces = 1;
continue;
}
errno = save_errno;
goto done;
}
}
if (eacces)
errno = EACCES;
else
errno = ENOENT;
done:
return (-1);
}
int
execvP(const char *name, const char *path, char * const argv[])
{
return execvPe(name, path, argv, environ);
}
int
_execvpe(const char *name, char * const argv[], char * const envp[])
{
const char *path;
/* Get the path we're searching. */
if ((path = getenv("PATH")) == NULL)
path = _PATH_DEFPATH;
return (execvPe(name, path, argv, envp));
}