Home | History | Annotate | Line # | Download | only in talk
look_up.c revision 1.3 
      1 /*	$NetBSD: look_up.c,v 1.3 1994/12/09 02:14:21 jtc Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1983, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #ifndef lint
     37 #if 0
     38 static char sccsid[] = "@(#)look_up.c	8.1 (Berkeley) 6/6/93";
     39 #endif
     40 static char rcsid[] = "$NetBSD: look_up.c,v 1.3 1994/12/09 02:14:21 jtc Exp $";
     41 #endif /* not lint */
     42 
     43 #include <sys/types.h>
     44 #include <sys/socket.h>
     45 #include <netinet/in.h>
     46 #include <protocols/talkd.h>
     47 #include <errno.h>
     48 #include "talk_ctl.h"
     49 #include "talk.h"
     50 
     51 /*
     52  * See if the local daemon has an invitation for us.
     53  */
     54 check_local()
     55 {
     56 	CTL_RESPONSE response;
     57 	register CTL_RESPONSE *rp = &response;
     58 
     59 	/* the rest of msg was set up in get_names */
     60 #ifdef MSG_EOR
     61 	/* copy new style sockaddr to old, swap family (short in old) */
     62 	msg.ctl_addr = *(struct osockaddr *)&ctl_addr;
     63 	msg.ctl_addr.sa_family = htons(ctl_addr.sin_family);
     64 #else
     65 	msg.ctl_addr = *(struct sockaddr *)&ctl_addr;
     66 #endif
     67 	/* must be initiating a talk */
     68 	if (!look_for_invite(rp))
     69 		return (0);
     70 	/*
     71 	 * There was an invitation waiting for us,
     72 	 * so connect with the other (hopefully waiting) party
     73 	 */
     74 	current_state = "Waiting to connect with caller";
     75 	do {
     76 		if (rp->addr.sa_family != AF_INET)
     77 			p_error("Response uses invalid network address");
     78 		errno = 0;
     79 		if (connect(sockt,
     80 		    (struct sockaddr *)&rp->addr, sizeof (rp->addr)) != -1)
     81 			return (1);
     82 	} while (errno == EINTR);
     83 	if (errno == ECONNREFUSED) {
     84 		/*
     85 		 * The caller gave up, but his invitation somehow
     86 		 * was not cleared. Clear it and initiate an
     87 		 * invitation. (We know there are no newer invitations,
     88 		 * the talkd works LIFO.)
     89 		 */
     90 		ctl_transact(his_machine_addr, msg, DELETE, rp);
     91 		close(sockt);
     92 		open_sockt();
     93 		return (0);
     94 	}
     95 	p_error("Unable to connect with initiator");
     96 	/*NOTREACHED*/
     97 }
     98 
     99 /*
    100  * Look for an invitation on 'machine'
    101  */
    102 look_for_invite(rp)
    103 	CTL_RESPONSE *rp;
    104 {
    105 	struct in_addr machine_addr;
    106 
    107 	current_state = "Checking for invitation on caller's machine";
    108 	ctl_transact(his_machine_addr, msg, LOOK_UP, rp);
    109 	/* the switch is for later options, such as multiple invitations */
    110 	switch (rp->answer) {
    111 
    112 	case SUCCESS:
    113 		msg.id_num = htonl(rp->id_num);
    114 		return (1);
    115 
    116 	default:
    117 		/* there wasn't an invitation waiting for us */
    118 		return (0);
    119 	}
    120 }
    121