summaryrefslogtreecommitdiffhomepage
path: root/sysklogd/klogd.c
blob: 4686a3429866e41664191e6ad4f473be6e5a0be9 (plain)
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
/* vi: set sw=4 ts=4: */
/*
 * Mini klogd implementation for busybox
 *
 * Copyright (C) 2001 by Gennady Feldman <gfeldman@cachier.com>.
 * Changes: Made this a standalone busybox module which uses standalone
 * 					syslog() client interface.
 *
 * Copyright (C) 1999,2000 by Lineo, inc. and Erik Andersen
 * Copyright (C) 1999,2000,2001 by Erik Andersen <andersee@debian.org>
 *
 * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
 *
 * "circular buffer" Copyright (C) 2000 by Gennady Feldman <gfeldman@mail.com>
 *
 * Maintainer: Gennady Feldman <gena01@cachier.com> as of Mar 12, 2001
 *
 * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>		/* for our signal() handlers */
#include <string.h>		/* strncpy() */
#include <errno.h>		/* errno and friends */
#include <unistd.h>
#include <ctype.h>
#include <sys/syslog.h>

#if __GNU_LIBRARY__ < 5
# ifdef __alpha__
#   define klogctl syslog
# endif
#else
# include <sys/klog.h>
#endif

#include "busybox.h"

static void klogd_signal(int sig)
{
	klogctl(7, NULL, 0);
	klogctl(0, 0, 0);
	/* logMessage(0, "Kernel log daemon exiting."); */
	syslog_msg(LOG_DAEMON, 0, "Kernel log daemon exiting.");
	exit(TRUE);
}

static void doKlogd(void) __attribute__ ((noreturn));
static void doKlogd(void)
{
	int priority = LOG_INFO;
	char log_buffer[4096];
	int i, n, lastc;
	char *start;

	/* Set up sig handlers */
	signal(SIGINT, klogd_signal);
	signal(SIGKILL, klogd_signal);
	signal(SIGTERM, klogd_signal);
	signal(SIGHUP, SIG_IGN);

	/* "Open the log. Currently a NOP." */
	klogctl(1, NULL, 0);

	syslog_msg(LOG_DAEMON, 0, "klogd started: " BB_BANNER);

	while (1) {
		/* Use kernel syscalls */
		memset(log_buffer, '\0', sizeof(log_buffer));
		n = klogctl(2, log_buffer, sizeof(log_buffer));
		if (n < 0) {
			char message[80];

			if (errno == EINTR)
				continue;
			snprintf(message, 79,
					 "klogd: Error return from sys_sycall: %d - %s.\n", errno,
					 strerror(errno));
			syslog_msg(LOG_DAEMON, LOG_SYSLOG | LOG_ERR, message);
			exit(1);
		}

		/* klogctl buffer parsing modelled after code in dmesg.c */
		start = &log_buffer[0];
		lastc = '\0';
		for (i = 0; i < n; i++) {
			if (lastc == '\0' && log_buffer[i] == '<') {
				priority = 0;
				i++;
				while (isdigit(log_buffer[i])) {
					priority = priority * 10 + (log_buffer[i] - '0');
					i++;
				}
				if (log_buffer[i] == '>')
					i++;
				start = &log_buffer[i];
			}
			if (log_buffer[i] == '\n') {
				log_buffer[i] = '\0';	/* zero terminate this message */
				syslog_msg(LOG_DAEMON, LOG_KERN | priority, start);
				start = &log_buffer[i + 1];
				priority = LOG_INFO;
			}
			lastc = log_buffer[i];
		}
	}
}

extern int klogd_main(int argc, char **argv)
{
	/* no options, no getopt */
	int opt;
	int doFork = TRUE;

	/* do normal option parsing */
	while ((opt = getopt(argc, argv, "n")) > 0) {
		switch (opt) {
		case 'n':
			doFork = FALSE;
			break;
		default:
			show_usage();
		}
	}

	if (doFork) {
#if !defined(__UCLIBC__) || defined(__UCLIBC_HAS_MMU__)
		if (daemon(0, 1) < 0)
			perror_msg_and_die("daemon");
#else
		error_msg_and_die("daemon not supported");
#endif
	}
	doKlogd();

	return EXIT_SUCCESS;
}

/*
Local Variables
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/