xbps/lib/fexec.c
Juan RP fd5afa2efb xbps_file_chdir_exec: check if /bin/sh is executable rather than readable.
--HG--
extra : convert_revision : xtraeme%40gmail.com-20090825040429-7fbwxo2fao20w28n
2009-08-25 06:04:29 +02:00

169 lines
3.9 KiB
C

/*-
* Copyright (c) 2003 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matthias Scheler.
*
* 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/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <xbps_api.h>
static int vfcexec(const char *, int, const char *, va_list);
static int pfcexec(const char *, const char *, const char **);
/*
* Fork, then if /bin/sh exists change root directory to
* path; otherwise just change current working directory.
* Execute the command and arguments in the argv array.
* wait for the command to finish, then return the exit status.
*/
static int
pfcexec(const char *path, const char *file, const char **argv)
{
pid_t child;
int status;
child = vfork();
switch (child) {
case 0:
if (path != NULL) {
/*
* If root and /bin/sh exists chroot to
* destdir and exec the command. Otherwise
* just change CWD to destdir.
*/
if (getuid() == 0 && access("./bin/sh", X_OK) == 0) {
if (chroot(path) == -1)
_exit(127);
if (chdir("/") == -1)
_exit(127);
} else {
if (chdir(path) == -1)
_exit(127);
}
}
(void)execvp(file, (char ** const)__UNCONST(argv));
_exit(127);
/* NOTREACHED */
case -1:
return -1;
}
while (waitpid(child, &status, 0) < 0) {
if (errno != EINTR)
return -1;
}
if (!WIFEXITED(status))
return -1;
return WEXITSTATUS(status);
}
static int
vfcexec(const char *path, int skipempty, const char *arg, va_list ap)
{
const char **argv;
size_t argv_size, argc;
int retval;
argv_size = 16;
if ((argv = malloc(argv_size * sizeof(*argv))) == NULL) {
errno = ENOMEM;
return -1;
}
argv[0] = arg;
argc = 1;
do {
if (argc == argv_size) {
argv_size *= 2;
argv = realloc(argv, argv_size * sizeof(*argv));
if (argv == NULL) {
errno = ENOMEM;
return -1;
}
}
arg = va_arg(ap, const char *);
if (skipempty && arg && strlen(arg) == 0)
continue;
argv[argc++] = arg;
} while (arg != NULL);
retval = pfcexec(path, argv[0], argv);
free(argv);
return retval;
}
int
xbps_file_exec(const char *arg, ...)
{
va_list ap;
int result;
va_start(ap, arg);
result = vfcexec(NULL, 0, arg, ap);
va_end(ap);
return result;
}
int
xbps_file_exec_skipempty(const char *arg, ...)
{
va_list ap;
int result;
va_start(ap, arg);
result = vfcexec(NULL, 1, arg, ap);
va_end(ap);
return result;
}
int
xbps_file_chdir_exec(const char *path, const char *arg, ...)
{
va_list ap;
int result;
va_start(ap, arg);
result = vfcexec(path, 0, arg, ap);
va_end(ap);
return result;
}