meillo@0: /* child.c, Copyright (C) 2000 by Oliver Kurth,
meillo@0:  *
meillo@0:  * This program is free software; you can redistribute it and/or modify
meillo@0:  * it under the terms of the GNU General Public License as published by
meillo@0:  * the Free Software Foundation; either version 2 of the License, or
meillo@0:  * (at your option) any later version.
meillo@10:  *
meillo@0:  * This program is distributed in the hope that it will be useful,
meillo@0:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
meillo@0:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
meillo@0:  * GNU General Public License for more details.
meillo@0:  *
meillo@0:  * You should have received a copy of the GNU General Public License
meillo@0:  * along with this program; if not, write to the Free Software
meillo@0:  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
meillo@0:  */
meillo@0: 
meillo@0: #include <errno.h>
meillo@0: #include <stdio.h>
meillo@0: #include <stdlib.h>
meillo@0: #include <unistd.h>
meillo@0: #include <signal.h>
meillo@0: #include <sys/types.h>
meillo@0: #include <sys/socket.h>
meillo@0: #include <syslog.h>
meillo@0: #include <string.h>
meillo@0: 
meillo@0: #include "masqmail.h"
meillo@0: 
meillo@0: int volatile sigchild_seen = 0;
meillo@0: 
meillo@10: static void
meillo@10: sigchild_handler(int sig)
meillo@0: {
meillo@10: 	sigchild_seen = 1;
meillo@10: 	signal(SIGHUP, sigchild_handler);
meillo@0: }
meillo@0: 
meillo@10: int
meillo@10: child(const char *command)
meillo@0: {
meillo@10: 	int pipe[2];
meillo@0: 
meillo@10: 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, pipe) == 0) {
meillo@10: 		pid_t pid;
meillo@0: 
meillo@10: 		/*
meillo@10: 		   sigchild_seen = 0;
meillo@10: 		   signal(SIGCHLD, sigchild_handler);
meillo@10: 		 */
meillo@0: 
meillo@10: 		pid = fork();
meillo@10: 		if (pid == 0) {
meillo@10: 			int i, max_fd = sysconf(_SC_OPEN_MAX);
meillo@10: 			/* child */
meillo@10: 			dup2(pipe[0], 0);
meillo@10: 			dup2(pipe[0], 1);
meillo@10: 			dup2(pipe[0], 2);
meillo@0: 
meillo@10: 			if (max_fd <= 0)
meillo@10: 				max_fd = 64;
meillo@10: 			for (i = 3; i < max_fd; i++)
meillo@10: 				close(i);
meillo@10: 
meillo@10: 			{
meillo@10: 				char *argv[] = { "/bin/sh", "-c", (char *) command, NULL };
meillo@10: 				execve(*argv, argv, NULL);
meillo@10: 			}
meillo@10: 			logwrite(LOG_ALERT, "execve failed: %s\n", strerror(errno));
meillo@10: 			_exit(EXIT_FAILURE);
meillo@10: 		} else if (pid == -1) {
meillo@10: 			return -1;
meillo@10: 		} else {
meillo@10: 			close(pipe[0]);
meillo@10: 			return pipe[1];
meillo@10: 		}
meillo@10: 	}
meillo@10: 	return -2;
meillo@0: }