path: root/src/ivyd.c

/*
 *	IvyDaemon, an Ivy gateway for short-lived agents
 * 
 *	Copyright (C) 1999
 *	Centre d'Études de la Navigation Aérienne
 *
 *	Main file for the server
 *
 *	Author(s): Stephane Chatty <chatty@cenatoulouse.dgac.fr>
 *		from code by Patrick Amar <pa@lri.fr>
 *
 *	$Id$
 *
 *	Please refer to file version.h for the
 *	copyright notice regarding this software
 *
 */

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>

#include <fcntl.h>
#include <memory.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <signal.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

#include "ivy.h"
#include "ivyd.h"

const char* const servicename = "ivyd";
const char* const port_env_variable = "INIVYD_PORT";
const int default_port = DEFAULT_INIVYD_PORT;

int debug = 0;

static void
Usage (const char* progname)
{
	fprintf (stderr, "Usage: %s [-b bus][-d]\n", progname);
	fprintf (stderr, " -d: does not fork so as to facilitate debugging\n");
	fprintf (stderr, " -b bus: selects Ivy bus on which to relay messages\n");
	exit (1);
}


/* 
 * Procedure to register with the super-daemon
 */
int
SendPort (int key, int port)
{
	struct servent *serv;
	u_short serv_port;
	struct sockaddr_in sin;
	struct connmsg msg;
	int sock;
	int res;

	serv = getservbyname (servicename, 0);
	if (! serv) {
		char *pp = getenv (port_env_variable);
		serv_port = htons (pp ? atoi (pp) : default_port);
		if (serv_port <= 0)
			exit (0);
	} else
		serv_port = serv -> s_port;

	sock = socket (AF_INET, SOCK_DGRAM, 0);
	if (sock == -1)
		return 0;

	memset (&sin, 0, sizeof sin);
	sin.sin_family = AF_INET;
	sin.sin_port = serv_port;
	sin.sin_addr.s_addr = LOCALHOST;

#if 0
	msg.msg_key = getuid ();
#else
	msg.msg_key = key;
#endif
	msg.msg_port = port;
	msg.msg_type = MSG_SERVER;


	res = sendto (sock, (char *)&msg, sizeof msg, 0, (struct sockaddr *)&sin, sizeof sin);

	/* We only detect local errors, but we have no guarantee that there is someone
	   at the other end. We should fix that someday (by going connected?) */

	if (res == -1)
		goto failed;

	(void) close (sock);
	return 1;

failed:
	(void) close (sock);
	return 0;
}


int
InitSocket (int key)
{
	int s, i;
	struct sockaddr_in addr;

	s = socket (AF_INET, SOCK_STREAM, 0);
	if (s < 0) {
		perror ("socket");
		return 0;
	}

	memset (&addr, 0, sizeof addr);
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = INADDR_ANY;

	if (bind (s, &addr, sizeof (addr)) == -1) {
		perror ("bind");
		return 0;
	}

	i = sizeof addr;
	if (getsockname (s, &addr, &i) == -1) {
		perror ("bind");
		return 0;
	}


	if (debug)
		printf ("Ivyd listens on port %d\n", ntohs (addr.sin_port));

	if (! SendPort (key, addr.sin_port)) {
		fprintf (stderr, "No Ivyd port server. Continuing with port = %d\n",
				ntohs (addr.sin_port));
	}

	/* je me debarrasse du terminal de controle */

/*	freopen ("/dev/tty", "r+", stderr); */
	for (i = 0; i < 32; i++)
		if (i != fileno (stderr) && i != s)
			close (i);

#ifndef SYSV
	i = open ("/dev/tty", 0);
	if (i != -1) {
		(void) ioctl (i, TIOCNOTTY, 0);
		close (i);
	}
#endif SYSV
	open ("/dev/null", 2); dup (0);


	if (listen (s, 5) == -1) {
		perror ("listen");
		return 0;
	}
	return s;
}


void
HandleRequests (void* ch, int fd, void* data)
{
	request req;
	char* p = (char*) &req;
	int n = sizeof (request);
	struct sockaddr_in addr;
	int len = sizeof (addr);

	if (debug)
		fprintf (stderr, "REQUEST on %d\n", fd);

	/* retrieve request */
	while (n > 0) {
#if 1
		int l = read (fd, p, n);
#else
		int l = recvfrom (fd, p, n, 0, (struct sockaddr*) &addr, &len);
#endif
		if (l < 0) {
			perror ("Error retrieving request from client");
			exit (0);
			return;
		} else if (l == 0) {
			if (debug)
				fprintf (stderr, "closing connection for %d\n", fd);
			IvyChannelClose (ch);
			close (fd);
			return;
		}
		n -= l;
		p += l;
	}

#if 0
	answer ans;
	ans.ok = 1;
	write (
#endif
	if (debug)
		fprintf (stderr, "REQUEST [%s]\n", req.buffer);
	IvySendMsg (req.buffer);
}

void
HandleConnections (void* ch, int fd, void* data)
{
	static struct sockaddr sa;
	static int acc;
	int newfd = accept (fd, &sa, &acc);
	if (debug)
		fprintf (stderr, "CONNECTION %d\n", newfd);
	IvyChannelSetUp (newfd, 0, 0, HandleRequests);
}

int
ExtractPort (const char* bus)
{
	int res = DEFAULT_BUS;
	const char* p;
	if (bus && (p = index (bus, ':'))) {
		res = atoi (p+1);
	}
	return res;
}

void
main (int argc, char **argv)
{
	int sock;
	char busbuf [128];
	int busport;
	const char* bus = 0;
	int c;

	/* handle args */
	while ((c = getopt (argc, argv, "b:d")) != EOF) {
		switch (c) {
		case 'b':
			strcpy (busbuf, optarg) ;
			bus = busbuf;
			break;
		case 'd':
			debug = 1;
			break;
		default:
			Usage (argv[0]);
		}
	}

	/* detach from tty */
	if (! debug)
		if (fork ())
			exit (0);

	/* determine port in bus address */
	busport = ExtractPort (bus);

	/* create server port */	
	sock = InitSocket (busport);

	/* this allows users to stop us cleanly */
	signal (SIGTERM, exit);

	
	/* Ivy initialization and main loop */
	IvyInit ("IVYD", 0, 0, 0, 0, 0);
	IvyChannelSetUp (sock, 0, 0, HandleConnections);
	IvyStart (bus);
	IvyMainLoop (0);
}