deb-mbse/lib/client.c

/*****************************************************************************
 *
 * $Id$
 * Purpose ...............: MBSE Deamon Client
 *
 *****************************************************************************
 * Copyright (C) 1993-2003
 *   
 * Michiel Broek		FIDO:	2:280/2802
 * Beekmansbos 10
 * 1971 BV IJmuiden
 * the Netherlands
 *
 * This file is part of MBSE BBS.
 *
 * This BBS 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, or (at your option) any
 * later version.
 *
 * MBSE BBS 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 MB BBS; see the file COPYING.  If not, write to the Free
 * Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *****************************************************************************/

#include "../config.h"
#include "libs.h"
#include "memwatch.h"
#include "clcomm.h"

static int		sock = -1;	/* Unix Datagram socket		*/
struct sockaddr_un      clntaddr;       /* Client socket address        */
struct sockaddr_un      servaddr;       /* Server socket address        */
struct sockaddr_un      from;           /* From socket address          */
int                     fromlen;
static char		*myname='\0';	/* my program name		*/
char			spath[108];     /* Server socket path           */
char			cpath[108];     /* Client socket path           */


/************************************************************************
 *
 * Connect to Unix Datagram socket, return -1 if error or socket no. 
 */

int socket_connect(char *user, char *prg, char *city)
{
	int 		s;
	static char	buf[SS_BUFSIZE];
	char		tty[18];

	myname = prg;

	/*
	 * Create Unix Datagram socket for the client.
	 */
	s = socket(AF_UNIX, SOCK_DGRAM, 0);
	if (s == -1) {
		perror(myname);
		printf("Unable to create Unix Datagram socket\n");
		return -1;
	}

	/*
	 * Client will bind to an address so the server will get
	 * an address in its recvfrom call and use it to send
	 * data back to the client.
	 */
	memset(&clntaddr, 0, sizeof(clntaddr));
	clntaddr.sun_family = AF_UNIX;
	strcpy(clntaddr.sun_path, cpath);

	if (bind(s, (struct sockaddr *)&clntaddr, sizeof(clntaddr)) < 0) {
		close(s);
		perror(myname);
		printf("Can't bind socket %s\n", cpath);
		return -1;
	}

	/*
	 * If running seteuid as another user, chown to mbse.bbs
	 */
	if (getuid() != geteuid()) {
		chown(cpath, getuid(), getgid());
	} else {
		chmod(cpath, 0775);
	}

	/*
	 * Setup address structure for the server socket.
	 */
	memset(&servaddr, 0, sizeof(servaddr));
	servaddr.sun_family = AF_UNIX;
	strcpy(servaddr.sun_path, spath);

	/*
	 * Now that we have an connection, we gather 
	 * information to tell the server who we are.
	 */
	if (isatty(1) && (ttyname(1) != NULL)) {
		strcpy(tty, ttyname(1));
		if (strchr(tty, 'p'))
			strcpy(tty, index(tty, 'p'));
		else if (strchr(tty, 't'))
			strcpy(tty, index(tty, 't'));
		else if (strchr(tty, 'c'))
			strcpy(tty, index(tty, 'c'));
	} else {
		strcpy(tty, "-");
	}
	sock = s;

	/*
	 * Send the information to the server. 
	 */
	sprintf(buf, "AINI:5,%d,%s,%s,%s,%s;", getpid(), tty, user, prg, city);
	if (socket_send(buf) != 0) {
		sock = -1;
		return -1;
	}

	strcpy(buf, socket_receive());
	if (strncmp(buf, "100:0;", 6) != 0) {
		printf("AINI not acknowledged by the server\n");
		sock = -1;
		return -1;
	}

	return s;
}



/*
 * Send data via internet domain socket
 */
int socket_send(char *buf)
{
	if (sock == -1)
		return -1;

        if (sendto(sock, buf, strlen(buf), 0, (struct sockaddr *)&servaddr, sizeof(servaddr)) != strlen(buf)) {
		printf("Socket send failed error %d\n", errno);
		return -1;
	}
	return 0;
}



/*
 * Return an empty buffer if somthing went wrong, else the complete
 * dataline is returned.
 */
char *socket_receive(void)
{
	static char	buf[SS_BUFSIZE];
	int		rlen;

	memset((char *)&buf, 0, SS_BUFSIZE);
        fromlen = sizeof(from);
        rlen = recvfrom(sock, buf, SS_BUFSIZE, 0, (struct sockaddr *)&from, &fromlen);
        if (rlen == -1) {
                perror("recv");
                printf("Error reading socket\n");
                memset((char *)&buf, 0, SS_BUFSIZE);
                return buf;
        }
	return buf;
}



/***************************************************************************
 *
 *  Shutdown the socket, first send the server the close command so this
 *  application will be removed from the servers active clients list.
 *  There must be a parameter with the pid so that client applications
 *  where the shutdown will be done by a child process is able to give
 *  the parent pid as an identifier.
 */

int socket_shutdown(pid_t pid)
{
	static char	buf[SS_BUFSIZE];

	if (sock == -1)
		return 0;

	sprintf(buf, "ACLO:1,%d;", pid);
 	if (socket_send(buf) == 0) {
		strcpy(buf, socket_receive());
		if (strncmp(buf, "107:0;", 6) != 0) {
			printf("Shutdown not acknowledged by the server\n");
			printf("Got \"%s\"\n", buf);
		}
	}
	
	if (shutdown(sock, 1) == -1) {
		perror(myname);
		printf("Cannot shutdown socket\n");
		return -1;
	}

	sock = -1;
	return 0;
}