usr/src/usr.bin/talk/look_up.c

#ifndef lint
static char sccsid[] = "@(#)look_up.c   1.2 (Berkeley) %G%";
#endif

#include "talk_ctl.h"

/*
 * See if the local daemon has a invitation for us
 */
check_local()
{
        CTL_RESPONSE response;

        /* the rest of msg was set up in get_names */
        msg.ctl_addr = ctl_addr;
        if (!look_for_invite(&response))        /* must be initiating a talk */
                return (0);
        /*
         * There was an invitation waiting for us,
         * so connect with the other (hopefully waiting) party
         */
        current_state = "Waiting to connect with caller";
again:
        if (connect(sockt, &response.addr, sizeof(response.addr)) != -1)
                return (1);
        if (errno == EINTR)
                goto again;
        if (errno == ECONNREFUSED) {
                /*
                 * The caller gave up, but his invitation somehow
                 * was not cleared. Clear it and initiate an
                 * invitation. (We know there are no newer invitations,
                 * the talkd works LIFO.)
                 */
                ctl_transact(his_machine_addr, msg, DELETE, &response);
                close(sockt);
                open_sockt();
                return (0);
        }
        p_error("Unable to connect with initiator");
        /*NOTREACHED*/
}

/*
 * Look for an invitation on 'machine'
 */
look_for_invite(response)
        CTL_RESPONSE *response;
{
        struct in_addr machine_addr;

        current_state = "Checking for invitation on caller's machine";
        ctl_transact(his_machine_addr, msg, LOOK_UP, response);
        /* the switch is for later options, such as multiple invitations */
        switch (response->answer) {

        case SUCCESS:
                msg.id_num = response->id_num;
                return (1);

        default :
                /* there wasn't an invitation waiting for us */
                return (0);
        }
}