1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
/* $OpenBSD: talkd.c,v 1.21 2004/08/08 19:32:45 deraadt Exp $ */
/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1983 Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
#ifndef lint
/*static char sccsid[] = "from: @(#)talkd.c 5.8 (Berkeley) 2/26/91";*/
static char rcsid[] = "$Id: talkd.c,v 1.21 2004/08/08 19:32:45 deraadt Exp $";
#endif /* not lint */
/*
* The top level of the daemon, the format is heavily borrowed
* from rwhod.c. Basically: find out who and where you are;
* disconnect all descriptors and ttys, and then endless
* loop on waiting for and processing requests
*/
#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <protocols/talkd.h>
#include <signal.h>
#include <syslog.h>
#include <time.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <paths.h>
#include "talkd.h"
int debug = 0;
void timeout(int);
long lastmsgtime;
char hostname[MAXHOSTNAMELEN];
#define TIMEOUT 30
#define MAXIDLE 120
int
main(int argc, char *argv[])
{
if (getuid() != 0) {
fprintf(stderr, "%s: getuid: not super-user\n", argv[0]);
exit(1);
}
openlog("talkd", LOG_PID, LOG_DAEMON);
if (gethostname(hostname, sizeof(hostname)) < 0) {
syslog(LOG_ERR, "gethostname: %m");
_exit(1);
}
if (chdir(_PATH_DEV) < 0) {
syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV);
_exit(1);
}
if (argc > 1 && strcmp(argv[1], "-d") == 0)
debug = 1;
init_table();
signal(SIGALRM, timeout);
alarm(TIMEOUT);
for (;;) {
CTL_RESPONSE response;
socklen_t len = sizeof(response.addr);
CTL_MSG request;
int cc;
struct sockaddr ctl_addr;
memset(&response, 0, sizeof(response));
cc = recvfrom(STDIN_FILENO, (char *)&request,
sizeof(request), 0, (struct sockaddr *)&response.addr,
&len);
if (cc != sizeof(request)) {
if (cc < 0 && errno != EINTR)
syslog(LOG_WARNING, "recvfrom: %m");
continue;
}
/* Force NUL termination */
request.l_name[sizeof(request.l_name) - 1] = '\0';
request.r_name[sizeof(request.r_name) - 1] = '\0';
request.r_tty[sizeof(request.r_tty) - 1] = '\0';
memcpy(&ctl_addr, &request.ctl_addr, sizeof(ctl_addr));
ctl_addr.sa_family = ntohs(request.ctl_addr.sa_family);
ctl_addr.sa_len = sizeof(ctl_addr);
if (ctl_addr.sa_family != AF_INET)
continue;
lastmsgtime = time(0);
process_request(&request, &response);
/* can block here, is this what I want? */
cc = sendto(STDOUT_FILENO, (char *)&response,
sizeof(response), 0, &ctl_addr, sizeof(ctl_addr));
if (cc != sizeof(response))
syslog(LOG_WARNING, "sendto: %m");
}
}
void
timeout(int signo)
{
int save_errno = errno;
if (time(0) - lastmsgtime >= MAXIDLE)
_exit(0);
alarm(TIMEOUT);
errno = save_errno;
}
|
