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
56 static CTL_MSG request;
57 static CTL_RESPONSE response;
58
59 int debug = 0;
60 static long lastmsgtime;
61
62 char hostname[MAXHOSTNAMELEN];
63
64 #define TIMEOUT 30
65 #define MAXIDLE 120
66
67 int
main(int argc,char * argv[])68 main(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
116 void
timeout(int sig __unused)117 timeout(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