talk.tproj/ctl_transact.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1983, 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58
  59 #include <sys/types.h>
  60 #include <sys/socket.h>
  61 #include <sys/time.h>
  62 #include <netinet/in.h>
  63 #include <protocols/talkd.h>
  64 #include <errno.h>
  65 #include "talk_ctl.h"
  66
  67 #define CTL_WAIT 2      /* time to wait for a response, in seconds */
  68
  69 /*
  70  * SOCKDGRAM is unreliable, so we must repeat messages if we have
  71  * not recieved an acknowledgement within a reasonable amount
  72  * of time
  73  */
  74 ctl_transact(target, msg, type, rp)
  75         struct in_addr target;
  76         CTL_MSG msg;
  77         int type;
  78         CTL_RESPONSE *rp;
  79 {
  80         int read_mask, ctl_mask, nready, cc;
  81         struct timeval wait;
  82
  83         msg.type = type;
  84         daemon_addr.sin_addr = target;
  85         daemon_addr.sin_port = daemon_port;
  86         ctl_mask = 1 << ctl_sockt;
  87
  88         /*
  89          * Keep sending the message until a response of
  90          * the proper type is obtained.
  91          */
  92         do {
  93                 wait.tv_sec = CTL_WAIT;
  94                 wait.tv_usec = 0;
  95                 /* resend message until a response is obtained */
  96                 do {
  97                         cc = sendto(ctl_sockt, (char *)&msg, sizeof (msg), 0,
  98                             (struct sockaddr *)&daemon_addr,
  99                             sizeof (daemon_addr));
 100                         if (cc != sizeof (msg)) {
 101                                 if (errno == EINTR)
 102                                         continue;
 103                                 p_error("Error on write to talk daemon");
 104                         }
 105                         read_mask = ctl_mask;
 106                         nready = select(32, &read_mask, 0, 0, &wait);
 107                         if (nready < 0) {
 108                                 if (errno == EINTR)
 109                                         continue;
 110                                 p_error("Error waiting for daemon response");
 111                         }
 112                 } while (nready == 0);
 113                 /*
 114                  * Keep reading while there are queued messages
 115                  * (this is not necessary, it just saves extra
 116                  * request/acknowledgements being sent)
 117                  */
 118                 do {
 119                         cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
 120                         if (cc < 0) {
 121                                 if (errno == EINTR)
 122                                         continue;
 123                                 p_error("Error on read from talk daemon");
 124                         }
 125                         read_mask = ctl_mask;
 126                         /* an immediate poll */
 127                         timerclear(&wait);
 128                         nready = select(32, &read_mask, 0, 0, &wait);
 129                 } while (nready > 0 && (rp->vers != TALK_VERSION ||
 130                     rp->type != type));
 131         } while (rp->vers != TALK_VERSION || rp->type != type);
 132         rp->id_num = ntohl(rp->id_num);
 133         rp->addr.sa_family = ntohs(rp->addr.sa_family);
 134 }