xref: /freebsd/usr.bin/talk/ctl_transact.c (revision 9336e0699bda8a301cd2bfa37106b6ec5e32012e)
1 /*
2  * Copyright (c) 1983, 1993
3  *	The Regents of the University of California.  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 #include <sys/cdefs.h>
35 
36 __FBSDID("$FreeBSD$");
37 
38 #ifndef lint
39 static const char sccsid[] = "@(#)ctl_transact.c	8.1 (Berkeley) 6/6/93";
40 #endif
41 
42 #include <arpa/inet.h>
43 
44 #include <errno.h>
45 #include <string.h>
46 
47 #include "talk.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, lmsg, type, rp)
59 	struct in_addr target;
60 	CTL_MSG lmsg;
61 	int type;
62 	CTL_RESPONSE *rp;
63 {
64 	fd_set read_mask, ctl_mask;
65 	int nready = 0, cc;
66 	struct timeval wait;
67 
68 	lmsg.type = type;
69 	daemon_addr.sin_addr = target;
70 	daemon_addr.sin_port = daemon_port;
71 	FD_ZERO(&ctl_mask);
72 	FD_SET(ctl_sockt, &ctl_mask);
73 
74 	/*
75 	 * Keep sending the message until a response of
76 	 * the proper type is obtained.
77 	 */
78 	do {
79 		wait.tv_sec = CTL_WAIT;
80 		wait.tv_usec = 0;
81 		/* resend message until a response is obtained */
82 		do {
83 			cc = sendto(ctl_sockt, (char *)&lmsg, sizeof (lmsg), 0,
84 			    (struct sockaddr *)&daemon_addr,
85 			    sizeof (daemon_addr));
86 			if (cc != sizeof (lmsg)) {
87 				if (errno == EINTR)
88 					continue;
89 				p_error("Error on write to talk daemon");
90 			}
91 			read_mask = ctl_mask;
92 			nready = select(32, &read_mask, 0, 0, &wait);
93 			if (nready < 0) {
94 				if (errno == EINTR)
95 					continue;
96 				p_error("Error waiting for daemon response");
97 			}
98 		} while (nready == 0);
99 		/*
100 		 * Keep reading while there are queued messages
101 		 * (this is not necessary, it just saves extra
102 		 * request/acknowledgements being sent)
103 		 */
104 		do {
105 			cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
106 			if (cc < 0) {
107 				if (errno == EINTR)
108 					continue;
109 				p_error("Error on read from talk daemon");
110 			}
111 			read_mask = ctl_mask;
112 			/* an immediate poll */
113 			timerclear(&wait);
114 			nready = select(32, &read_mask, 0, 0, &wait);
115 		} while (nready > 0 && (rp->vers != TALK_VERSION ||
116 		    rp->type != type));
117 	} while (rp->vers != TALK_VERSION || rp->type != type);
118 	rp->id_num = ntohl(rp->id_num);
119 	rp->addr.sa_family = ntohs(rp->addr.sa_family);
120 }
121