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ctl_transact.c revision 1.5 
      1 /*	$NetBSD: ctl_transact.c,v 1.5 2001/06/12 15:17:30 wiz Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1983, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static char sccsid[] = "@(#)ctl_transact.c	8.1 (Berkeley) 6/6/93";
     40 #endif
     41 __RCSID("$NetBSD: ctl_transact.c,v 1.5 2001/06/12 15:17:30 wiz Exp $");
     42 #endif /* not lint */
     43 
     44 #include "talk.h"
     45 #include <sys/time.h>
     46 #include <errno.h>
     47 #include <unistd.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 received an acknowledgement within a reasonable amount
     55  * of time
     56  */
     57 void
     58 ctl_transact(target, msg, type, rp)
     59 	struct in_addr target;
     60 	CTL_MSG msg;
     61 	int type;
     62 	CTL_RESPONSE *rp;
     63 {
     64 	fd_set read_mask, ctl_mask;
     65 	int nready, cc;
     66 	struct timeval wait;
     67 
     68 	nready = 0;
     69 	msg.type = type;
     70 	daemon_addr.sin_addr = target;
     71 	daemon_addr.sin_port = daemon_port;
     72 	FD_ZERO(&ctl_mask);
     73 	FD_SET(ctl_sockt, &ctl_mask);
     74 
     75 	/*
     76 	 * Keep sending the message until a response of
     77 	 * the proper type is obtained.
     78 	 */
     79 	do {
     80 		wait.tv_sec = CTL_WAIT;
     81 		wait.tv_usec = 0;
     82 		/* resend message until a response is obtained */
     83 		do {
     84 			cc = sendto(ctl_sockt, (char *)&msg, sizeof (msg), 0,
     85 			    (struct sockaddr *)&daemon_addr,
     86 			    sizeof (daemon_addr));
     87 			if (cc != sizeof (msg)) {
     88 				if (errno == EINTR)
     89 					continue;
     90 				p_error("Error on write to talk daemon");
     91 			}
     92 			read_mask = ctl_mask;
     93 			nready = select(32, &read_mask, 0, 0, &wait);
     94 			if (nready < 0) {
     95 				if (errno == EINTR)
     96 					continue;
     97 				p_error("Error waiting for daemon response");
     98 			}
     99 		} while (nready == 0);
    100 		/*
    101 		 * Keep reading while there are queued messages
    102 		 * (this is not necessary, it just saves extra
    103 		 * request/acknowledgements being sent)
    104 		 */
    105 		do {
    106 			cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
    107 			if (cc < 0) {
    108 				if (errno == EINTR)
    109 					continue;
    110 				p_error("Error on read from talk daemon");
    111 			}
    112 			read_mask = ctl_mask;
    113 			/* an immediate poll */
    114 			timerclear(&wait);
    115 			nready = select(32, &read_mask, 0, 0, &wait);
    116 		} while (nready > 0 && (rp->vers != TALK_VERSION ||
    117 		    rp->type != type));
    118 	} while (rp->vers != TALK_VERSION || rp->type != type);
    119 	rp->id_num = ntohl(rp->id_num);
    120 	rp->addr.sa_family = ntohs(rp->addr.sa_family);
    121 }
    122