BSD 4_2 release

[unix-history] / usr / src / ucb / talk / look_up.c

/* $Header: look_up.c 1.2 83/03/28 00:34:22 moore Exp $ */

#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)) {

           /* we 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";

   while (connect(sockt, &response.addr, sizeof(response.addr)) != 0) {
       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);
       } else if (errno == EINTR) {
               /* we have returned from an interupt handler */
           continue;
       } else {
           p_error("Unable to connect with initiator");
       }
   }

   return(1);
}

   /* 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);
   }
}