[ On Mon, March 20, 1995 at 04:05:29 (-0500), Roland McGrath wrote: ]
> Subject: poor man's demand-dial
>

I've been reading these posts with interest, but I'm confused that
nobody's thought of an obvious solution.....

By using a special line discipline, control of the PPP connection can be
done via special ioctl()'s, and the messy stuff can

For example (some ugly pseudo-code):

	while (dialing) {
		if ((ppp_if = allocate_ppp_interface(dest_host)) == EOF) {
			print_no_interface_msg();
			continue;
		}
		if (interface_config(ppp_if) == EOF) {
			print_interface_config_failed_msg();
			continue;
		}
		wait_for_packet_on_ppp_if(ppp_if);
		if ((outdial_port = find_free_port(ppp_if)) == EOF) {
			print_ports_busy_msg();
			cleanup();
			continue;
		}
		if (do_dial(outdial_port) == EOF) {
			print_dial_failed_msg();
			cleanup();
			continue;
		}
		if (do_login(outdial_port) == EOF) {
			print_login_failed_msg();
			cleanup();
			continue;
		}
		old_line_discipline = LINE0;
		(void) ioctl(outdial_port.fd, TIOCGETD, &old_line_discipline);
		ppp_line_discipline = PPP0;
		if (ioctl(outdial_port.fd, TIOCSETD, &ppp_line_discipline) == EOF) {
			print_setd_failed_msg();
			cleanup();
			continue;
		}
		/* here we hand the connection over to the ppp interface */
		if (ioctl(outdial_port.fd, PPP_START_PROTO, &ppp_if) == EOF) {
			print_cant_ppp_on_if_msg();
			cleanup();
			contine;
		}
		/* now we wait for the interface to drop the connection,
		 * either through losing the line, or through a manual
		 * "ifconfig pppIF down", or by giving it up because it
		 * has been idle for too long....
		 */
		if (ioctl(outdial_port.fd, PPP_WAIT_END_OF_SESS) == EOF) {
			print_wait_eos_failed_msg();
			cleanup();
			continue;
		}
		if (ioctl(outdial_port.fd, TIOSETD, &old_line_discipline) == EOF) {
			print_setd_old_ld_failed_msg();
			cleanup();
			continue;
		}
		if (close(outdial_port.fd) == EOF) {
			print_cant_hangup_msg();
			cleanup();
			continue;
		}
		continue;
	}

-- 
							Greg A. Woods

+1 416 443-1734			VE3TCP			robohack!woods
Planix, Inc. <woods@planix.com>; Secrets Of The Weird <woods@weird.com>