talk.tproj/ctl_transact.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 <sys/time.h>
  61 #include <netinet/in.h>
  62 #include <protocols/talkd.h>
  63 #include <errno.h>
  64 #include "talk_ctl.h"
  65
  66 #define CTL_WAIT 2      /* time to wait for a response, in seconds */
  67
  68 /*
  69  * SOCKDGRAM is unreliable, so we must repeat messages if we have
  70  * not recieved an acknowledgement within a reasonable amount
  71  * of time
  72  */
  73 ctl_transact(target, msg, type, rp)
  74         struct in_addr target;
  75         CTL_MSG msg;
  76         int type;
  77         CTL_RESPONSE *rp;
  78 {
  79         int read_mask, ctl_mask, nready, cc;
  80         struct timeval wait;
  81
  82         msg.type = type;
  83         daemon_addr.sin_addr = target;
  84         daemon_addr.sin_port = daemon_port;
  85         ctl_mask = 1 << ctl_sockt;
  86
  87         /*
  88          * Keep sending the message until a response of
  89          * the proper type is obtained.
  90          */
  91         do {
  92                 wait.tv_sec = CTL_WAIT;
  93                 wait.tv_usec = 0;
  94                 /* resend message until a response is obtained */
  95                 do {
  96                         cc = sendto(ctl_sockt, (char *)&msg, sizeof (msg), 0,
  97                             (struct sockaddr *)&daemon_addr,
  98                             sizeof (daemon_addr));
  99                         if (cc != sizeof (msg)) {
 100                                 if (errno == EINTR)
 101                                         continue;
 102                                 p_error("Error on write to talk daemon");
 103                         }
 104                         read_mask = ctl_mask;
 105                         nready = select(32, &read_mask, 0, 0, &wait);
 106                         if (nready < 0) {
 107                                 if (errno == EINTR)
 108                                         continue;
 109                                 p_error("Error waiting for daemon response");
 110                         }
 111                 } while (nready == 0);
 112                 /*
 113                  * Keep reading while there are queued messages
 114                  * (this is not necessary, it just saves extra
 115                  * request/acknowledgements being sent)
 116                  */
 117                 do {
 118                         cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
 119                         if (cc < 0) {
 120                                 if (errno == EINTR)
 121                                         continue;
 122                                 p_error("Error on read from talk daemon");
 123                         }
 124                         read_mask = ctl_mask;
 125                         /* an immediate poll */
 126                         timerclear(&wait);
 127                         nready = select(32, &read_mask, 0, 0, &wait);
 128                 } while (nready > 0 && (rp->vers != TALK_VERSION ||
 129                     rp->type != type));
 130         } while (rp->vers != TALK_VERSION || rp->type != type);
 131         rp->id_num = ntohl(rp->id_num);
 132         rp->addr.sa_family = ntohs(rp->addr.sa_family);
 133 }