xref: /openbsd-src/usr.bin/talk/ctl_transact.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: ctl_transact.c,v 1.10 2004/03/02 21:04:42 tedu Exp $	*/
2 /*	$NetBSD: ctl_transact.c,v 1.3 1994/12/09 02:14:12 jtc Exp $	*/
3 
4 /*
5  * Copyright (c) 1983, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)ctl_transact.c	8.1 (Berkeley) 6/6/93";
36 #endif
37 static const char rcsid[] = "$OpenBSD: ctl_transact.c,v 1.10 2004/03/02 21:04:42 tedu Exp $";
38 #endif /* not lint */
39 
40 #include "talk.h"
41 #include <sys/time.h>
42 #include <errno.h>
43 #include <unistd.h>
44 #include <poll.h>
45 #include "talk_ctl.h"
46 
47 #define CTL_WAIT 2	/* time to wait for a response, in seconds */
48 
49 /*
50  * SOCKDGRAM is unreliable, so we must repeat messages if we have
51  * not received an acknowledgement within a reasonable amount
52  * of time
53  */
54 void
55 ctl_transact(target, msg, type, rp)
56 	struct in_addr target;
57 	CTL_MSG msg;
58 	int type;
59 	CTL_RESPONSE *rp;
60 {
61 	struct pollfd pfd[1];
62 	int nready, cc;
63 
64 	msg.type = type;
65 	daemon_addr.sin_addr = target;
66 	daemon_addr.sin_port = daemon_port;
67 	pfd[0].fd = ctl_sockt;
68 	pfd[0].events = POLLIN;
69 
70 	/*
71 	 * Keep sending the message until a response of
72 	 * the proper type is obtained.
73 	 */
74 	do {
75 		/* resend message until a response is obtained */
76 		do {
77 			cc = sendto(ctl_sockt, (char *)&msg, sizeof (msg), 0,
78 			    (struct sockaddr *)&daemon_addr,
79 			    sizeof (daemon_addr));
80 			if (cc != sizeof (msg)) {
81 				if (errno == EINTR)
82 					continue;
83 				quit("Error on write to talk daemon", 1);
84 			}
85 			nready = poll(pfd, 1, CTL_WAIT * 1000);
86 			if (nready < 0) {
87 				if (errno == EINTR)
88 					continue;
89 				quit("Error waiting for daemon response", 1);
90 			}
91 		} while (nready == 0);
92 		/*
93 		 * Keep reading while there are queued messages
94 		 * (this is not necessary, it just saves extra
95 		 * request/acknowledgements being sent)
96 		 */
97 		do {
98 			cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
99 			if (cc < 0) {
100 				if (errno == EINTR)
101 					continue;
102 				quit("Error on read from talk daemon", 1);
103 			}
104 			nready = poll(pfd, 1, 0);
105 		} while (nready > 0 && (rp->vers != TALK_VERSION ||
106 		    rp->type != type));
107 	} while (rp->vers != TALK_VERSION || rp->type != type);
108 	rp->id_num = ntohl(rp->id_num);
109 }
110