1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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
33
34 #include <arpa/inet.h>
35
36 #include <errno.h>
37 #include <poll.h>
38
39 #include "talk.h"
40 #include "talk_ctl.h"
41
42 #define CTL_WAIT 2 /* time to wait for a response, in seconds */
43
44 /*
45 * SOCKDGRAM is unreliable, so we must repeat messages if we have
46 * not received an acknowledgement within a reasonable amount
47 * of time
48 */
49 void
ctl_transact(struct in_addr target,CTL_MSG lmsg,int type,CTL_RESPONSE * rp)50 ctl_transact(struct in_addr target, CTL_MSG lmsg, int type, CTL_RESPONSE *rp)
51 {
52 struct pollfd pfd[1];
53 int nready = 0, cc;
54
55 lmsg.type = type;
56 daemon_addr.sin_addr = target;
57 daemon_addr.sin_port = daemon_port;
58 pfd[0].fd = ctl_sockt;
59 pfd[0].events = POLLIN;
60
61 /*
62 * Keep sending the message until a response of
63 * the proper type is obtained.
64 */
65 do {
66 /* resend message until a response is obtained */
67 do {
68 cc = sendto(ctl_sockt, (char *)&lmsg, sizeof (lmsg), 0,
69 (struct sockaddr *)&daemon_addr,
70 sizeof (daemon_addr));
71 if (cc != sizeof (lmsg)) {
72 if (errno == EINTR)
73 continue;
74 p_error("Error on write to talk daemon");
75 }
76 nready = poll(pfd, 1, CTL_WAIT * 1000);
77 if (nready < 0) {
78 if (errno == EINTR)
79 continue;
80 p_error("Error waiting for daemon response");
81 }
82 } while (nready == 0);
83 /*
84 * Keep reading while there are queued messages
85 * (this is not necessary, it just saves extra
86 * request/acknowledgements being sent)
87 */
88 do {
89 cc = recv(ctl_sockt, (char *)rp, sizeof (*rp), 0);
90 if (cc < 0) {
91 if (errno == EINTR)
92 continue;
93 p_error("Error on read from talk daemon");
94 }
95 nready = poll(pfd, 1, 0);
96 } while (nready > 0 && (rp->vers != TALK_VERSION ||
97 rp->type != type));
98 } while (rp->vers != TALK_VERSION || rp->type != type);
99 rp->id_num = ntohl(rp->id_num);
100 rp->addr.sa_family = ntohs(rp->addr.sa_family);
101 }
102