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    Length: 3759 (0xeaf)
    Types: TextFile
    Names: »invite.c«

└─⟦b20c6495f⟧ Bits:30007238 EUUGD18: Wien-båndet, efterår 1987
    └─⟦this⟧ »EUUGD18/General/Bridge/invite.c« 

TextFile

#ifndef lint
static	char sccsid[] = "@(#)invite.c 1.1 86/02/05 SMI"; /* from UCB 1.7 83/07/06 */
#endif

#include "talk_ctl.h"
#include <sys/time.h>
#include <signal.h>
#include <setjmp.h>
    
    /*
     * there wasn't an invitation waiting, so send a request containing
     * our sockt address to the remote talk daemon so it can invite
     * him 
     */

int local_id, remote_id;	/* the msg.id's for the invitations
				   on the local and remote machines.
				   These are used to delete the 
				   invitations. */
void re_invite();
jmp_buf	invitebuf;

invite_remote()
{
    int nfd, read_mask, template, new_sockt;
    struct itimerval itimer;
    CTL_RESPONSE response;

    itimer.it_value.tv_sec = RING_WAIT;
    itimer.it_value.tv_usec = 0;
    itimer.it_interval = itimer.it_value;

    if (listen(sockt, 5) != 0) {
	p_error("Error on attempt to listen for caller");
    }

    msg.addr = my_addr;
    msg.id_num = -1;		/* an impossible id_num */

    invitation_waiting = 1;

    announce_invite();

	/*
	 * shut off the automatic messages for a while,
	 * so we can use the interupt timer to resend the invitation
	 */

    setitimer(ITIMER_REAL, &itimer, (struct itimerval *)0);
    message("Waiting for your party to respond");
    signal(SIGALRM, re_invite);
    (void) setjmp(invitebuf);

    while ((new_sockt = accept(sockt, 0, 0)) < 0) {
	if (errno != EINTR) {
	    p_error("Unable to connect with your party");
	} else {
	    /* we just returned from a interupt, keep trying */
	    continue;
	}
    }

    close(sockt);
    sockt = new_sockt;

	/* have the daemons delete the invitations now that we
	   have connected.
	 */

    current_state = "Waiting for your party to respond";

    msg.id_num = local_id;
    ctl_transact(my_machine_addr, msg, DELETE, &response);
    msg.id_num = remote_id;
    ctl_transact(his_machine_addr, msg, DELETE, &response);
    invitation_waiting = 0;
}

    /* routine called on interupt to re-invite the callee */

void re_invite()
{
    message("Ringing your party again");
    current_line++;
	/* force a re-announce */
    msg.id_num = remote_id + 1;
    announce_invite();
    longjmp(invitebuf, 1);
}

    /* transmit the invitation and process the response */

announce_invite()
{
    CTL_RESPONSE response;

    current_state = "Trying to connect to your party's talk daemon";

    ctl_transact(his_machine_addr, msg, ANNOUNCE, &response);
    remote_id = response.id_num;

    if (response.answer != SUCCESS) {

	switch (response.answer) {
	    
	    case NOT_HERE :
		message("Your party is not logged on");
		break;

	    case MACHINE_UNKNOWN :
		message("Target machine does not recognize us");
		break;

	    case UNKNOWN_REQUEST :
		message("Target machine can not handle remote talk");
		break;

	    case FAILED :
		message("Target machine is too confused to talk to us");
		break;

	    case PERMISSION_DENIED :
		message("Your party is refusing messages");
		break;
	}

	quit();
    }

	/* leave the actual invitation on my talk daemon */

    ctl_transact(my_machine_addr, msg, LEAVE_INVITE, &response);
    local_id = response.id_num;
}
    
send_delete()
{
	/* tell the daemon to remove your invitation */

    msg.type = DELETE;

	/* this is just a extra clean up, so just send it
	   and don't wait for an answer */

    msg.id_num = remote_id;
    daemon_addr.sin_addr = his_machine_addr;
    if (sendto(ctl_sockt, &msg, sizeof(CTL_MSG), 0, &daemon_addr,
		    sizeof(daemon_addr)) != sizeof(CTL_MSG)) {
	    perror("send_delete remote");
    }

    msg.id_num = local_id;
    daemon_addr.sin_addr = my_machine_addr;
    if (sendto(ctl_sockt, &msg, sizeof(CTL_MSG), 0, &daemon_addr,
		    sizeof(daemon_addr)) != sizeof(CTL_MSG)) {
	    perror("send_delete local");
    }
}