usr.bin/talk/ctl_transact.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/cdefs.h>
  35
  36 __FBSDID("$FreeBSD$");
  37
  38 #ifndef lint
  39 static const char sccsid[] = "@(#)ctl_transact.c        8.1 (Berkeley) 6/6/93";
  40 #endif
  41
  42 #include <arpa/inet.h>
  43
  44 #include <errno.h>
  45 #include <string.h>
  46
  47 #include "talk.h"
  48 #include "talk_ctl.h"
  49
  50 #define CTL_WAIT 2      /* time to wait for a response, in seconds */
  51
  52 /*
  53  * SOCKDGRAM is unreliable, so we must repeat messages if we have
  54  * not recieved an acknowledgement within a reasonable amount
  55  * of time
  56  */
  57 void
  58 ctl_transact(struct in_addr target, CTL_MSG lmsg, int type, CTL_RESPONSE *rp)
  59 {
  60         fd_set read_mask, ctl_mask;
  61         int nready = 0, cc;
  62         struct timeval wait;
  63
  64         lmsg.type = type;
  65         daemon_addr.sin_addr = target;
  66         daemon_addr.sin_port = daemon_port;
  67         FD_ZERO(&ctl_mask);
  68         FD_SET(ctl_sockt, &ctl_mask);
  69
  70         /*
  71          * Keep sending the message until a response of
  72          * the proper type is obtained.
  73          */
  74         do {
  75                 wait.tv_sec = CTL_WAIT;
  76                 wait.tv_usec = 0;
  77                 /* resend message until a response is obtained */
  78                 do {
  79                         cc = sendto(ctl_sockt, (char *)&lmsg, sizeof (lmsg), 0,
  80                             (struct sockaddr *)&daemon_addr,
  81                             sizeof (daemon_addr));
  82                         if (cc != sizeof (lmsg)) {
  83                                 if (errno == EINTR)
  84                                         continue;
  85                                 p_error("Error on write to talk daemon");
  86                         }
  87                         read_mask = ctl_mask;
  88                         nready = select(32, &read_mask, 0, 0, &wait);
  89                         if (nready < 0) {
  90                                 if (errno == EINTR)
  91                                         continue;
  92                                 p_error("Error waiting for daemon response");
  93                         }
  94                 } while (nready == 0);
  95                 /*
  96                  * Keep reading while there are queued messages
  97                  * (this is not necessary, it just saves extra
  98                  * request/acknowledgements being sent)
  99                  */
 100                 do {
 101                         cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
 102                         if (cc < 0) {
 103                                 if (errno == EINTR)
 104                                         continue;
 105                                 p_error("Error on read from talk daemon");
 106                         }
 107                         read_mask = ctl_mask;
 108                         /* an immediate poll */
 109                         timerclear(&wait);
 110                         nready = select(32, &read_mask, 0, 0, &wait);
 111                 } while (nready > 0 && (rp->vers != TALK_VERSION ||
 112                     rp->type != type));
 113         } while (rp->vers != TALK_VERSION || rp->type != type);
 114         rp->id_num = ntohl(rp->id_num);
 115         rp->addr.sa_family = ntohs(rp->addr.sa_family);
 116 }