talk.tproj/look_up.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1983, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  *
  27  * Redistribution and use in source and binary forms, with or without
  28  * modification, are permitted provided that the following conditions
  29  * are met:
  30  * 1. Redistributions of source code must retain the above copyright
  31  *    notice, this list of conditions and the following disclaimer.
  32  * 2. Redistributions in binary form must reproduce the above copyright
  33  *    notice, this list of conditions and the following disclaimer in the
  34  *    documentation and/or other materials provided with the distribution.
  35  * 3. All advertising materials mentioning features or use of this software
  36  *    must display the following acknowledgement:
  37  *      This product includes software developed by the University of
  38  *      California, Berkeley and its contributors.
  39  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  */
  55
  56
  57 #include <sys/types.h>
  58 #include <sys/socket.h>
  59 #include <netinet/in.h>
  60 #include <protocols/talkd.h>
  61 #include <errno.h>
  62 #include "talk_ctl.h"
  63 #include "talk.h"
  64
  65 /*
  66  * See if the local daemon has an invitation for us.
  67  */
  68 check_local()
  69 {
  70         CTL_RESPONSE response;
  71         register CTL_RESPONSE *rp = &response;
  72
  73         /* the rest of msg was set up in get_names */
  74 #ifdef MSG_EOR
  75         /* copy new style sockaddr to old, swap family (short in old) */
  76         msg.ctl_addr = *(struct osockaddr *)&ctl_addr;
  77         msg.ctl_addr.sa_family = htons(ctl_addr.sin_family);
  78 #else
  79         msg.ctl_addr = *(struct sockaddr *)&ctl_addr;
  80 #endif
  81         /* must be initiating a talk */
  82         if (!look_for_invite(rp))
  83                 return (0);
  84         /*
  85          * There was an invitation waiting for us,
  86          * so connect with the other (hopefully waiting) party
  87          */
  88         current_state = "Waiting to connect with caller";
  89         do {
  90                 if (rp->addr.sa_family != AF_INET)
  91                         p_error("Response uses invalid network address");
  92                 errno = 0;
  93                 if (connect(sockt,
  94                     (struct sockaddr *)&rp->addr, sizeof (rp->addr)) != -1)
  95                         return (1);
  96         } while (errno == EINTR);
  97         if (errno == ECONNREFUSED) {
  98                 /*
  99                  * The caller gave up, but his invitation somehow
 100                  * was not cleared. Clear it and initiate an
 101                  * invitation. (We know there are no newer invitations,
 102                  * the talkd works LIFO.)
 103                  */
 104                 ctl_transact(his_machine_addr, msg, DELETE, rp);
 105                 close(sockt);
 106                 open_sockt();
 107                 return (0);
 108         }
 109         p_error("Unable to connect with initiator");
 110         /*NOTREACHED*/
 111 }
 112
 113 /*
 114  * Look for an invitation on 'machine'
 115  */
 116 look_for_invite(rp)
 117         CTL_RESPONSE *rp;
 118 {
 119         struct in_addr machine_addr;
 120
 121         current_state = "Checking for invitation on caller's machine";
 122         ctl_transact(his_machine_addr, msg, LOOK_UP, rp);
 123         /* the switch is for later options, such as multiple invitations */
 124         switch (rp->answer) {
 125
 126         case SUCCESS:
 127                 msg.id_num = htonl(rp->id_num);
 128                 return (1);
 129
 130         default:
 131                 /* there wasn't an invitation waiting for us */
 132                 return (0);
 133         }
 134 }