#

#include	"util.h"
#include	"pkts.h"
#include	<ioctl.h>

#define	NFIL	20
#define	TERM	15
#define SIGAIO	17

#define	NINTRUP	01
int	netf;
int	net;

char	devnet[] = {"/dev/net"};
char	server[] = {"/etc/stelnet"};
char	dir[] =	{"/etc"};
char	tmp[] =	{"/etc/locks/lsntmp"};
char   	lock[] = {"/etc/locks/listen"};


/* Listen is a stub process which waits for a packet to TCP
socket 23 and then forks a server telnet -
it forks twice to prevent the accumulation of "defunct"
processes.  Defunct processes come about when
the process which forks it 1) does not wait (i.e. wait())
for its child to finish or 2) does not exit before 
its child finishes. For case 2) the child becomes a
child of process 1 which is always waiting for its
children.
*/

main()
{
	char		netfds[20];
	int		status;
	short		mode, term();
	register int	nserver, i;

	chdir(dir);
	for (i = 0; i < NFIL; i++)
		close(i);

	open("/dev/null", 0);		/* Make next file channel 1 */
	creat(tmp, 0444);
	printf("%d\n", getpid());
	fflush(stdout);
	close(1);
	open("/dev/cty", 1);
	if (link(tmp, lock) == -1) {
		unlink(tmp);
		printf("update: another daemon exists\n");
		exit(0);
		}		
	signal(TERM, &term);
	unlink(tmp);

	nserver = 0;

	netf = 0;
	signal(SIGAIO, &netint);

	if (!tel_listen(&netfds)) exit();

	while(1) {
		mode = NINTRUP;
		ioctl(net, NIOCSETL, &mode);
		while (netf == 0)
			pause();

		nserver++;
		netf = 0;
		mode = 0;
		ioctl(net, NIOCSETL, &mode);

		if (fork() != 0) {
			wait(&status);
			continue;
			}
		else {
			if (fork() != 0)
				exit();
			execl(server, server, netfds, 0);
			}
		}
}

netint()
{
	netf++;
}

tel_listen(nfds)
char	*nfds;
{
	struct netdf {
		short	n_prot1;
		short	n_prot2;
		long	n_fhost;
		short	n_fskt;
		short	n_lskt;
		} netdf;

	register struct netdf	*ndp;

	ndp = &netdf;

	ndp->n_prot1 = INETPROT;
	ndp->n_prot2 = TCPPROT;
	ndp->n_fhost = 0;
	ndp->n_fskt = 0;
	ndp->n_lskt = TELNETICP;

	if ((net = netopen(devnet, ndp)) == ERR) {
		printf("tel_listen  cannot open to net error %d\n", errno);
		return(FALSE);
		}

	sprintf(nfds, "%d", net);
	return(TRUE);
}

term()

{	unlink(lock);
	exit(0);
}