xref: /386bsd/usr/src/usr.bin/talk/ctl_transact.c (revision a2142627)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * 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 #ifndef lint
35 static char sccsid[] = "@(#)ctl_transact.c	5.8 (Berkeley) 3/1/91";
36 #endif /* not lint */
37 
38 #include <sys/types.h>
39 #include <sys/socket.h>
40 #include <sys/time.h>
41 #include <netinet/in.h>
42 #include <protocols/talkd.h>
43 #include <errno.h>
44 #include "talk_ctl.h"
45 
46 #define CTL_WAIT 2	/* time to wait for a response, in seconds */
47 
48 /*
49  * SOCKDGRAM is unreliable, so we must repeat messages if we have
50  * not recieved an acknowledgement within a reasonable amount
51  * of time
52  */
53 ctl_transact(target, msg, type, rp)
54 	struct in_addr target;
55 	CTL_MSG msg;
56 	int type;
57 	CTL_RESPONSE *rp;
58 {
59 	int read_mask, ctl_mask, nready, cc;
60 	struct timeval wait;
61 
62 	msg.type = type;
63 	daemon_addr.sin_addr = target;
64 	daemon_addr.sin_port = daemon_port;
65 	ctl_mask = 1 << ctl_sockt;
66 
67 	/*
68 	 * Keep sending the message until a response of
69 	 * the proper type is obtained.
70 	 */
71 	do {
72 		wait.tv_sec = CTL_WAIT;
73 		wait.tv_usec = 0;
74 		/* resend message until a response is obtained */
75 		do {
76 			cc = sendto(ctl_sockt, (char *)&msg, sizeof (msg), 0,
77 			    (struct sockaddr *)&daemon_addr,
78 			    sizeof (daemon_addr));
79 			if (cc != sizeof (msg)) {
80 				if (errno == EINTR)
81 					continue;
82 				p_error("Error on write to talk daemon");
83 			}
84 			read_mask = ctl_mask;
85 			nready = select(32, &read_mask, 0, 0, &wait);
86 			if (nready < 0) {
87 				if (errno == EINTR)
88 					continue;
89 				p_error("Error waiting for daemon response");
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 				p_error("Error on read from talk daemon");
103 			}
104 			read_mask = ctl_mask;
105 			/* an immediate poll */
106 			timerclear(&wait);
107 			nready = select(32, &read_mask, 0, 0, &wait);
108 		} while (nready > 0 && (rp->vers != TALK_VERSION ||
109 		    rp->type != type));
110 	} while (rp->vers != TALK_VERSION || rp->type != type);
111 	rp->id_num = ntohl(rp->id_num);
112 	rp->addr.sa_family = ntohs(rp->addr.sa_family);
113 }
114