1 /* $NetBSD: ctl_transact.c,v 1.11 2011/09/06 18:32:03 joerg 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. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)ctl_transact.c 8.1 (Berkeley) 6/6/93";
36 #endif
37 __RCSID("$NetBSD: ctl_transact.c,v 1.11 2011/09/06 18:32:03 joerg 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
ctl_transact(struct in_addr target,CTL_MSG tmsg,int type,CTL_RESPONSE * rp)55 ctl_transact(struct in_addr target, CTL_MSG tmsg, int type, CTL_RESPONSE *rp)
56 {
57 struct pollfd set[1];
58 int nready, cc;
59
60 nready = 0;
61 tmsg.type = type;
62 daemon_addr.sin_addr = target;
63 daemon_addr.sin_port = daemon_port;
64 set[0].fd = ctl_sockt;
65 set[0].events = POLLIN;
66
67 /*
68 * Keep sending the message until a response of
69 * the proper type is obtained.
70 */
71 do {
72 /* resend message until a response is obtained */
73 do {
74 cc = sendto(ctl_sockt, (char *)&tmsg, sizeof (tmsg), 0,
75 (struct sockaddr *)&daemon_addr,
76 sizeof (daemon_addr));
77 if (cc != sizeof (tmsg)) {
78 if (errno == EINTR)
79 continue;
80 p_error("Error on write to talk daemon");
81 }
82 nready = poll(set, 1, CTL_WAIT * 1000);
83 if (nready < 0) {
84 if (errno == EINTR)
85 continue;
86 p_error("Error waiting for daemon response");
87 }
88 } while (nready == 0);
89 /*
90 * Keep reading while there are queued messages
91 * (this is not necessary, it just saves extra
92 * request/acknowledgements being sent)
93 */
94 do {
95 cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
96 if (cc < 0) {
97 if (errno == EINTR)
98 continue;
99 p_error("Error on read from talk daemon");
100 }
101 /* an immediate poll */
102 nready = poll(set, 1, 0);
103 } while (nready > 0 && (rp->vers != TALK_VERSION ||
104 rp->type != type));
105 } while (rp->vers != TALK_VERSION || rp->type != type);
106 rp->id_num = ntohl(rp->id_num);
107 rp->addr.sa_family = ntohs(rp->addr.sa_family);
108 }
109