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
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
/*
* Simple update daemon for Linux.
* Copyright (c) 1996, 1997, 1999 Torsten Poulin.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdio.h>
#include <unistd.h>
#include <limits.h>
#include <stdlib.h>
#include <signal.h>
#include <getopt.h>
#include <syslog.h>
#if defined(__GLIBC__) && __GLIBC__ >= 2
# include <sys/kdaemon.h>
#else
# include <asm/unistd.h> /* FIXME! */
_syscall2(int, bdflush, int, func, int, data);
#endif
#ifndef RESTRICT_TO_ROOT
# define RESTRICT_TO_ROOT 1
#endif
#define VERSTR "update 2.11\n"
#define HELPSTR \
"Usage: %s [OPTION]\n\n"\
" -S, --use-sync force use of sync(2) instead of flushing\n"\
" -s, --sync-interval SECS call sync this often (default 30)\n"\
" -f, --flush-interval SECS flush some buffers this often (default 5)\n"\
" --help display this text and exit\n"\
" --version output version information and exit\n\n"\
"--sync-interval implies --use-sync.\n"
/* OPEN_MAX is POSIX.1 */
#ifndef OPEN_MAX
# define OPEN_MAX 256 /* anybody's guess */
#endif
#ifndef lint
static const char vcid[] = "$Id: update.c,v 1.10 1999/05/23 22:59:16 tp Exp $";
#endif /* lint */
static unsigned int sync_duration = 30;
static unsigned int flush_duration = 5;
static int use_sync = 0;
static void usage(char *name)
{
fprintf(stderr, "Try `%s --help\' for more information.\n", name);
exit(2);
}
/*
* The update() function never returns.
*
* In Linux 2.2.8, user space update is unnecessary and bdflush(1, 0)
* always returns an error. If this happens, we just log it and exit.
*
* This new behavior in 2.2.8 was actually backed out in 2.2.9, but is
* expected to go in again later.
*/
static void update(void)
{
for (;;) {
if (use_sync) {
sleep(sync_duration);
sync();
} else {
sleep(flush_duration);
if (bdflush(1, 0) < 0) {
openlog("update", LOG_CONS, LOG_DAEMON);
syslog(LOG_INFO,
"This kernel does not need update(8). Exiting.");
closelog();
exit(0);
}
}
}
}
int main(int argc, char **argv)
{
int f;
for (;;) {
int option_index = 0;
int c;
static struct option long_options[] = {
{ "use-sync", 0, 0, 'S' },
{ "sync-interval", 1, 0, 's' },
{ "flush-interval", 1, 0, 'f' },
{ "help", 0, 0, 'h' },
{ "version", 0, 0, 'V' },
{ 0, 0, 0, 0 }
};
c = getopt_long(argc, argv, "Ss:f:", long_options, &option_index);
if (c == -1)
break;
/* Long option? */
if (c == 0)
c = long_options[option_index].val;
switch (c) {
case 'S':
use_sync = 1;
break;
case 's':
if ((sync_duration = atoi(optarg)) <= 0) {
fprintf(stderr, "%s: argument must be positive integer\n",
argv[0]);
exit(2);
}
use_sync = 1;
break;
case 'f':
if ((flush_duration = atoi(optarg)) <= 0) {
fprintf(stderr, "%s: argument must be a positive integer\n",
argv[0]);
exit(2);
}
break;
case 'h':
printf(HELPSTR, *argv);
exit(0);
case 'V':
printf(VERSTR);
exit(0);
case '?':
usage(argv[0]);
default:
abort();
}
}
if (optind < argc)
usage(argv[0]);
#if RESTRICT_TO_ROOT
/* Keep people from launching more update daemons.
Might as well call sync(). */
if (geteuid() != 0) {
sync();
fprintf(stderr, "%s: should only be run by root.\n", argv[0]);
exit(1);
}
#endif
/* Ignore a few signals for good measure. */
signal(SIGTERM, SIG_IGN);
signal(SIGINT, SIG_IGN);
if (fork() > 0)
exit(0);
/* Become session leader (get rid of controlling terminal). */
setsid();
/* Make sure we are on a file system that stays mounted. */
chdir("/");
for (f = 0; f < OPEN_MAX; f++)
close(f);
update();
return 0;
}
|
