1 |
|
|
/* $OpenBSD: talkd.c,v 1.25 2016/02/05 10:13:51 mestre Exp $ */ |
2 |
|
|
|
3 |
|
|
/* |
4 |
|
|
* Copyright (c) 1983 Regents of the University of California. |
5 |
|
|
* 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/socket.h> |
39 |
|
|
#include <protocols/talkd.h> |
40 |
|
|
|
41 |
|
|
#include <errno.h> |
42 |
|
|
#include <limits.h> |
43 |
|
|
#include <paths.h> |
44 |
|
|
#include <signal.h> |
45 |
|
|
#include <stdio.h> |
46 |
|
|
#include <stdlib.h> |
47 |
|
|
#include <string.h> |
48 |
|
|
#include <syslog.h> |
49 |
|
|
#include <unistd.h> |
50 |
|
|
|
51 |
|
|
#include "talkd.h" |
52 |
|
|
|
53 |
|
|
int debug = 0; |
54 |
|
|
void timeout(int); |
55 |
|
|
long lastmsgtime; |
56 |
|
|
|
57 |
|
|
char hostname[HOST_NAME_MAX+1]; |
58 |
|
|
|
59 |
|
|
#define TIMEOUT 30 |
60 |
|
|
#define MAXIDLE 120 |
61 |
|
|
|
62 |
|
|
int |
63 |
|
|
main(int argc, char *argv[]) |
64 |
|
|
{ |
65 |
|
|
if (getuid() != 0) { |
66 |
|
|
fprintf(stderr, "%s: getuid: not super-user\n", argv[0]); |
67 |
|
|
exit(1); |
68 |
|
|
} |
69 |
|
|
openlog("talkd", LOG_PID, LOG_DAEMON); |
70 |
|
|
if (gethostname(hostname, sizeof(hostname)) < 0) { |
71 |
|
|
syslog(LOG_ERR, "gethostname: %m"); |
72 |
|
|
_exit(1); |
73 |
|
|
} |
74 |
|
|
if (chdir(_PATH_DEV) < 0) { |
75 |
|
|
syslog(LOG_ERR, "chdir: %s: %m", _PATH_DEV); |
76 |
|
|
_exit(1); |
77 |
|
|
} |
78 |
|
|
if (argc > 1 && strcmp(argv[1], "-d") == 0) |
79 |
|
|
debug = 1; |
80 |
|
|
init_table(); |
81 |
|
|
signal(SIGALRM, timeout); |
82 |
|
|
alarm(TIMEOUT); |
83 |
|
|
|
84 |
|
|
if (pledge("stdio rpath wpath cpath inet dns flock", NULL) == -1) { |
85 |
|
|
syslog(LOG_ERR, "pledge: %m"); |
86 |
|
|
_exit(1); |
87 |
|
|
} |
88 |
|
|
|
89 |
|
|
for (;;) { |
90 |
|
|
CTL_RESPONSE response; |
91 |
|
|
socklen_t len = sizeof(response.addr); |
92 |
|
|
CTL_MSG request; |
93 |
|
|
int cc; |
94 |
|
|
struct sockaddr ctl_addr; |
95 |
|
|
|
96 |
|
|
memset(&response, 0, sizeof(response)); |
97 |
|
|
cc = recvfrom(STDIN_FILENO, (char *)&request, |
98 |
|
|
sizeof(request), 0, (struct sockaddr *)&response.addr, |
99 |
|
|
&len); |
100 |
|
|
if (cc != sizeof(request)) { |
101 |
|
|
if (cc < 0 && errno != EINTR) |
102 |
|
|
syslog(LOG_WARNING, "recvfrom: %m"); |
103 |
|
|
continue; |
104 |
|
|
} |
105 |
|
|
|
106 |
|
|
/* Force NUL termination */ |
107 |
|
|
request.l_name[sizeof(request.l_name) - 1] = '\0'; |
108 |
|
|
request.r_name[sizeof(request.r_name) - 1] = '\0'; |
109 |
|
|
request.r_tty[sizeof(request.r_tty) - 1] = '\0'; |
110 |
|
|
|
111 |
|
|
memcpy(&ctl_addr, &request.ctl_addr, sizeof(ctl_addr)); |
112 |
|
|
ctl_addr.sa_family = ntohs(request.ctl_addr.sa_family); |
113 |
|
|
ctl_addr.sa_len = sizeof(ctl_addr); |
114 |
|
|
if (ctl_addr.sa_family != AF_INET) |
115 |
|
|
continue; |
116 |
|
|
|
117 |
|
|
lastmsgtime = time(0); |
118 |
|
|
process_request(&request, &response); |
119 |
|
|
/* can block here, is this what I want? */ |
120 |
|
|
cc = sendto(STDOUT_FILENO, (char *)&response, |
121 |
|
|
sizeof(response), 0, &ctl_addr, sizeof(ctl_addr)); |
122 |
|
|
if (cc != sizeof(response)) |
123 |
|
|
syslog(LOG_WARNING, "sendto: %m"); |
124 |
|
|
} |
125 |
|
|
} |
126 |
|
|
|
127 |
|
|
void |
128 |
|
|
timeout(int signo) |
129 |
|
|
{ |
130 |
|
|
int save_errno = errno; |
131 |
|
|
|
132 |
|
|
if (time(0) - lastmsgtime >= MAXIDLE) |
133 |
|
|
_exit(0); |
134 |
|
|
alarm(TIMEOUT); |
135 |
|
|
errno = save_errno; |
136 |
|
|
} |