xref: /freebsd/usr.bin/talk/ctl_transact.c (revision 1670a1c2a47d10ecccd001970b859caf93cd3b6e)
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 
46 #include "talk.h"
47 #include "talk_ctl.h"
48 
49 #define CTL_WAIT 2	/* time to wait for a response, in seconds */
50 
51 /*
52  * SOCKDGRAM is unreliable, so we must repeat messages if we have
53  * not recieved an acknowledgement within a reasonable amount
54  * of time
55  */
56 void
57 ctl_transact(struct in_addr target, CTL_MSG lmsg, int type, CTL_RESPONSE *rp)
58 {
59 	fd_set read_mask, ctl_mask;
60 	int nready = 0, cc;
61 	struct timeval wait;
62 
63 	lmsg.type = type;
64 	daemon_addr.sin_addr = target;
65 	daemon_addr.sin_port = daemon_port;
66 	FD_ZERO(&ctl_mask);
67 	FD_SET(ctl_sockt, &ctl_mask);
68 
69 	/*
70 	 * Keep sending the message until a response of
71 	 * the proper type is obtained.
72 	 */
73 	do {
74 		wait.tv_sec = CTL_WAIT;
75 		wait.tv_usec = 0;
76 		/* resend message until a response is obtained */
77 		do {
78 			cc = sendto(ctl_sockt, (char *)&lmsg, sizeof (lmsg), 0,
79 			    (struct sockaddr *)&daemon_addr,
80 			    sizeof (daemon_addr));
81 			if (cc != sizeof (lmsg)) {
82 				if (errno == EINTR)
83 					continue;
84 				p_error("Error on write to talk daemon");
85 			}
86 			read_mask = ctl_mask;
87 			nready = select(32, &read_mask, 0, 0, &wait);
88 			if (nready < 0) {
89 				if (errno == EINTR)
90 					continue;
91 				p_error("Error waiting for daemon response");
92 			}
93 		} while (nready == 0);
94 		/*
95 		 * Keep reading while there are queued messages
96 		 * (this is not necessary, it just saves extra
97 		 * request/acknowledgements being sent)
98 		 */
99 		do {
100 			cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
101 			if (cc < 0) {
102 				if (errno == EINTR)
103 					continue;
104 				p_error("Error on read from talk daemon");
105 			}
106 			read_mask = ctl_mask;
107 			/* an immediate poll */
108 			timerclear(&wait);
109 			nready = select(32, &read_mask, 0, 0, &wait);
110 		} while (nready > 0 && (rp->vers != TALK_VERSION ||
111 		    rp->type != type));
112 	} while (rp->vers != TALK_VERSION || rp->type != type);
113 	rp->id_num = ntohl(rp->id_num);
114 	rp->addr.sa_family = ntohs(rp->addr.sa_family);
115 }
116