4.3BSD - /usr/src/ucb/talk/ctl_transact.c

   1: /*
   2:  * Copyright (c) 1983 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifndef lint
   8: static char sccsid[] = "@(#)ctl_transact.c	5.2 (Berkeley) 3/13/86";
   9: #endif not lint
  10: 
  11: #include "talk_ctl.h"
  12: #include <sys/time.h>
  13: 
  14: #define CTL_WAIT 2  /* time to wait for a response, in seconds */
  15: 
  16: /*
  17:  * SOCKDGRAM is unreliable, so we must repeat messages if we have
  18:  * not recieved an acknowledgement within a reasonable amount
  19:  * of time
  20:  */
  21: ctl_transact(target, msg, type, rp)
  22:     struct in_addr target;
  23:     CTL_MSG msg;
  24:     int type;
  25:     CTL_RESPONSE *rp;
  26: {
  27:     int read_mask, ctl_mask, nready, cc;
  28:     struct timeval wait;
  29: 
  30:     msg.type = type;
  31:     daemon_addr.sin_addr = target;
  32:     daemon_addr.sin_port = daemon_port;
  33:     ctl_mask = 1 << ctl_sockt;
  34: 
  35:     /*
  36: 	 * Keep sending the message until a response of
  37: 	 * the proper type is obtained.
  38: 	 */
  39:     do {
  40:         wait.tv_sec = CTL_WAIT;
  41:         wait.tv_usec = 0;
  42:         /* resend message until a response is obtained */
  43:         do {
  44:             cc = sendto(ctl_sockt, (char *)&msg, sizeof (msg), 0,
  45:                 &daemon_addr, sizeof (daemon_addr));
  46:             if (cc != sizeof (msg)) {
  47:                 if (errno == EINTR)
  48:                     continue;
  49:                 p_error("Error on write to talk daemon");
  50:             }
  51:             read_mask = ctl_mask;
  52:             nready = select(32, &read_mask, 0, 0, &wait);
  53:             if (nready < 0) {
  54:                 if (errno == EINTR)
  55:                     continue;
  56:                 p_error("Error waiting for daemon response");
  57:             }
  58:         } while (nready == 0);
  59:         /*
  60: 		 * Keep reading while there are queued messages
  61: 		 * (this is not necessary, it just saves extra
  62: 		 * request/acknowledgements being sent)
  63: 		 */
  64:         do {
  65:             cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
  66:             if (cc < 0) {
  67:                 if (errno == EINTR)
  68:                     continue;
  69:                 p_error("Error on read from talk daemon");
  70:             }
  71:             read_mask = ctl_mask;
  72:             /* an immediate poll */
  73:             timerclear(&wait);
  74:             nready = select(32, &read_mask, 0, 0, &wait);
  75:         } while (nready > 0 && (rp->vers != TALK_VERSION ||
  76:             rp->type != type));
  77:     } while (rp->vers != TALK_VERSION || rp->type != type);
  78:     rp->id_num = ntohl(rp->id_num);
  79:     rp->addr.sa_family = ntohs(rp->addr.sa_family);
  80: }

Defined functions

Defined variables

Defined macros