Colony » Colony Scout

/*

 * Copyright (c) 2005-2006, Kohsuke Ohtani

 * 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 author nor the names of any co-contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/prex.h>

#include <ipc/exec.h>

#include <ipc/ipc.h>

#include <unistd.h>

#include <limits.h>

#include <string.h>

#include <errno.h>

#include <stdlib.h>

/*

 * Note:

 *

 * The state after exec() are as follows:

 * - Opened file descriptors remain open except FD_CLOEXEC flag is set.

 * - Opened directory streams are closed

 * - Signals set to the default action.

 * - Any asynchronous I/O operations are cancelled.

 */

int

execve(const char *path, char * const *argv, char * const *envp)

{

        object_t execobj;

        struct exec_msg msg;

        int error, i, argc, envc;

        size_t bufsz;

        char *dest, *src;

        if ((error = object_lookup("!exec", &execobj)) != 0)

                return ENOSYS;

        if (path == NULL)

                return EFAULT;

/*

    if (strlen(path) >= PATH_MAX)

        return ENAMETOOLONG;

*/

        /* Get arg/env buffer size */

        bufsz = 0;

        argc = 0;

        if (argv) {

                while (argv[argc]) {

                        bufsz += (strlen(argv[argc]) + 1);

                        argc++;

                }

        }

        envc = 0;

        if (envp) {

                while (envp[envc]) {

                        bufsz += (strlen(envp[envc]) + 1);

                        envc++;

                }

        }

        if (bufsz >= ARG_MAX)

                return E2BIG;

        dest = msg.buf;

        for (i = 0; i < argc; i++) {

                src = argv[i];

                while ((*dest++ = *src++) != 0);

        }

        for (i = 0; i < envc; i++) {

                src = envp[i];

                while ((*dest++ = *src++) != 0);

        }

        /* Request to exec server */

        msg.hdr.code = EXEC_EXECVE;

        msg.argc = argc;

        msg.envc = envc;

        msg.bufsz = bufsz;

        getcwd(msg.cwd, PATH_MAX);

        strlcpy(msg.path, path, PATH_MAX);

        do {

                error = msg_send(execobj, &msg, sizeof(msg));

        } while (error == EINTR);

        /*

         * If exec() request is done successfully, control never comes here.

         */

        errno = 0;

        if (error)

                errno = EIO;

        else if (msg.hdr.status)

                errno = msg.hdr.status;

        return -1;

}