xref: /netbsd-src/usr.bin/talk/ctl_transact.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: ctl_transact.c,v 1.4 1997/10/20 00:23:16 lukem 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 1.4 1997/10/20 00:23:16 lukem 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 recieved 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