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 * The top level of the daemon, the format is heavily borrowed
34 * from rwhod.c. Basically: find out who and where you are;
35 * disconnect all descriptors and ttys, and then endless
36 * loop on waiting for and processing requests
37 */
38#include <sys/types.h>
39#include <sys/socket.h>
40#include <sys/param.h>
41#include <netinet/in.h>
42#include <protocols/talkd.h>
43#include <err.h>
44#include <errno.h>
45#include <paths.h>
46#include <signal.h>
47#include <stdio.h>
48#include <stdlib.h>
49#include <string.h>
50#include <syslog.h>
51#include <time.h>
52#include <unistd.h>
53
54#include "extern.h"
55
56static CTL_MSG		request;
57static CTL_RESPONSE	response;
58
59int			debug = 0;
60static long		lastmsgtime;
61
62char			hostname[MAXHOSTNAMELEN];
63
64#define TIMEOUT 30
65#define MAXIDLE 120
66
67int
68main(int argc, char *argv[])
69{
70	register CTL_MSG *mp = &request;
71	int cc;
72	struct sockaddr ctl_addr;
73
74#ifdef NOTDEF
75	/*
76	 * removed so ntalkd can run in tty sandbox
77	 */
78	if (getuid())
79		errx(1, "getuid: not super-user");
80#endif
81	openlog("talkd", LOG_PID, LOG_DAEMON);
82	if (gethostname(hostname, sizeof(hostname) - 1) < 0) {
83		syslog(LOG_ERR, "gethostname: %m");
84		_exit(1);
85	}
86	hostname[sizeof(hostname) - 1] = '\0';
87	if (chdir(_PATH_DEV) < 0) {
88		syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
89		_exit(1);
90	}
91	if (argc > 1 && strcmp(argv[1], "-d") == 0)
92		debug = 1;
93	signal(SIGALRM, timeout);
94	alarm(TIMEOUT);
95	for (;;) {
96		cc = recv(0, (char *)mp, sizeof(*mp), 0);
97		if (cc != sizeof (*mp)) {
98			if (cc < 0 && errno != EINTR)
99				syslog(LOG_WARNING, "recv: %m");
100			continue;
101		}
102		lastmsgtime = time(0);
103		(void)memcpy(&ctl_addr.sa_data, &mp->ctl_addr.sa_data,
104		    sizeof(ctl_addr.sa_data));
105		ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
106		ctl_addr.sa_len = sizeof(ctl_addr);
107		process_request(mp, &response);
108		/* can block here, is this what I want? */
109		cc = sendto(STDIN_FILENO, (char *)&response,
110		    sizeof(response), 0, &ctl_addr, sizeof(ctl_addr));
111		if (cc != sizeof (response))
112			syslog(LOG_WARNING, "sendto: %m");
113	}
114}
115
116void
117timeout(int sig __unused)
118{
119	int save_errno = errno;
120
121	if (time(0) - lastmsgtime >= MAXIDLE)
122		_exit(0);
123	alarm(TIMEOUT);
124	errno = save_errno;
125}
126