view src/child.c @ 281:ea5f86e0a81c

modes are now enforced exclusive Other MTAs (exim, postfix) are more relaxing, but as combinations of exclusive modes are senseless we behave more obvious if we fail early. This makes understanding the behavior easier too.
author markus schnalke <meillo@marmaro.de>
date Tue, 07 Dec 2010 14:04:56 -0300
parents fc1c6425c024
children b27f66555ba8
line wrap: on
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/* child.c, Copyright (C) 2000 by Oliver Kurth,
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <syslog.h>
#include <string.h>

#include "masqmail.h"


int
child(const char *command)
{
	int pipe[2];

	if (socketpair(AF_UNIX, SOCK_STREAM, 0, pipe) == 0) {
		pid_t pid;

		pid = fork();
		if (pid == 0) {
			int i, max_fd = sysconf(_SC_OPEN_MAX);
			/* child */
			dup2(pipe[0], 0);
			dup2(pipe[0], 1);
			dup2(pipe[0], 2);

			if (max_fd <= 0)
				max_fd = 64;
			for (i = 3; i < max_fd; i++)
				close(i);

			{
				char *argv[] = { "/bin/sh", "-c", (char *) command, NULL };
				execve(*argv, argv, NULL);
			}
			logwrite(LOG_ALERT, "execve failed: %s\n", strerror(errno));
			_exit(1);
		} else if (pid == -1) {
			return -1;
		} else {
			close(pipe[0]);
			return pipe[1];
		}
	}
	return -2;
}