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