talk.tproj/look_up.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.0 (the 'License').  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License."
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1983, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgement:
  38  *      This product includes software developed by the University of
  39  *      California, Berkeley and its contributors.
  40  * 4. Neither the name of the University nor the names of its contributors
  41  *    may be used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  54  * SUCH DAMAGE.
  55  */
  56
  57
  58 #include <sys/types.h>
  59 #include <sys/socket.h>
  60 #include <netinet/in.h>
  61 #include <protocols/talkd.h>
  62 #include <errno.h>
  63 #include "talk_ctl.h"
  64 #include "talk.h"
  65
  66 /*
  67  * See if the local daemon has an invitation for us.
  68  */
  69 check_local()
  70 {
  71         CTL_RESPONSE response;
  72         register CTL_RESPONSE *rp = &response;
  73
  74         /* the rest of msg was set up in get_names */
  75 #ifdef MSG_EOR
  76         /* copy new style sockaddr to old, swap family (short in old) */
  77         msg.ctl_addr = *(struct osockaddr *)&ctl_addr;
  78         msg.ctl_addr.sa_family = htons(ctl_addr.sin_family);
  79 #else
  80         msg.ctl_addr = *(struct sockaddr *)&ctl_addr;
  81 #endif
  82         /* must be initiating a talk */
  83         if (!look_for_invite(rp))
  84                 return (0);
  85         /*
  86          * There was an invitation waiting for us,
  87          * so connect with the other (hopefully waiting) party
  88          */
  89         current_state = "Waiting to connect with caller";
  90         do {
  91                 if (rp->addr.sa_family != AF_INET)
  92                         p_error("Response uses invalid network address");
  93                 errno = 0;
  94                 if (connect(sockt,
  95                     (struct sockaddr *)&rp->addr, sizeof (rp->addr)) != -1)
  96                         return (1);
  97         } while (errno == EINTR);
  98         if (errno == ECONNREFUSED) {
  99                 /*
 100                  * The caller gave up, but his invitation somehow
 101                  * was not cleared. Clear it and initiate an
 102                  * invitation. (We know there are no newer invitations,
 103                  * the talkd works LIFO.)
 104                  */
 105                 ctl_transact(his_machine_addr, msg, DELETE, rp);
 106                 close(sockt);
 107                 open_sockt();
 108                 return (0);
 109         }
 110         p_error("Unable to connect with initiator");
 111         /*NOTREACHED*/
 112 }
 113
 114 /*
 115  * Look for an invitation on 'machine'
 116  */
 117 look_for_invite(rp)
 118         CTL_RESPONSE *rp;
 119 {
 120         struct in_addr machine_addr;
 121
 122         current_state = "Checking for invitation on caller's machine";
 123         ctl_transact(his_machine_addr, msg, LOOK_UP, rp);
 124         /* the switch is for later options, such as multiple invitations */
 125         switch (rp->answer) {
 126
 127         case SUCCESS:
 128                 msg.id_num = htonl(rp->id_num);
 129                 return (1);
 130
 131         default:
 132                 /* there wasn't an invitation waiting for us */
 133                 return (0);
 134         }
 135 }