busybox/sysklogd/klogd.c

/* vi: set sw=4 ts=4: */
/*
 * Mini klogd implementation for busybox
 *
 * Copyright (C) 2001 by Gennady Feldman <gfeldman@gena01.com>.
 * Changes: Made this a standalone busybox module which uses standalone
 *					syslog() client interface.
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
 *
 * "circular buffer" Copyright (C) 2000 by Gennady Feldman <gfeldman@gena01.com>
 *
 * Maintainer: Gennady Feldman <gfeldman@gena01.com> as of Mar 12, 2001
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include "libbb.h"
#include <syslog.h>
#include <sys/klog.h>

static void klogd_signal(int sig)
{
	/* FYI: cmd 7 is equivalent to setting console_loglevel to 7
	 * via klogctl(8, NULL, 7). */
	klogctl(7, NULL, 0); /* "7 -- Enable printk's to console" */
	klogctl(0, NULL, 0); /* "0 -- Close the log. Currently a NOP" */
	syslog(LOG_NOTICE, "klogd: exiting");
	kill_myself_with_sig(sig);
}

#define log_buffer bb_common_bufsiz1
enum {
	KLOGD_LOGBUF_SIZE = sizeof(log_buffer),
	OPT_LEVEL      = (1 << 0),
	OPT_FOREGROUND = (1 << 1),
};

int klogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int klogd_main(int argc UNUSED_PARAM, char **argv)
{
	int i = 0;
	char *start;
	int opt;
	int used = 0;

	opt = getopt32(argv, "c:n", &start);
	if (opt & OPT_LEVEL) {
		/* Valid levels are between 1 and 8 */
		i = xatou_range(start, 1, 8);
	}
	if (!(opt & OPT_FOREGROUND)) {
		bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
	}

	openlog("kernel", 0, LOG_KERN);

	bb_signals(0
		+ (1 << SIGINT)
		+ (1 << SIGTERM)
		, klogd_signal);
	signal(SIGHUP, SIG_IGN);

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

	/* "printk() prints a message on the console only if it has a loglevel
	 * less than console_loglevel". Here we set console_loglevel = i. */
	if (i)
		klogctl(8, NULL, i);

	syslog(LOG_NOTICE, "klogd started: %s", bb_banner);

	while (1) {
		int n;
		int priority;

		/* "2 -- Read from the log." */
		n = klogctl(2, log_buffer + used, KLOGD_LOGBUF_SIZE-1 - used);
		if (n < 0) {
			if (errno == EINTR)
				continue;
			syslog(LOG_ERR, "klogd: error %d in klogctl(2): %m",
					errno);
			break;
		}
		log_buffer[used + n] = '\0';

		/* klogctl buffer parsing modelled after code in dmesg.c */
		start = &log_buffer[0];

		/* Process each newline-terminated line in the buffer */
		while (1) {
			char *newline = strchr(start, '\n');

			if (!newline) {
				/* This line is incomplete... */
				if (start != log_buffer) {
					/* move it to the front of the buffer */
					overlapping_strcpy(log_buffer, start);
					/* don't log it yet */
					used = strlen(log_buffer);
					break;
				}
				/* ...but buffer is full, so log it anyway */
				used = 0;
			} else {
				*newline++ = '\0';
			}

			/* Extract the priority */
			priority = LOG_INFO;
			if (*start == '<') {
				start++;
				if (*start) {
					/* kernel never generates multi-digit prios */
					priority = (*start - '0');
					start++;
				}
				if (*start == '>') {
					start++;
				}
			}
			if (*start)
				syslog(priority, "%s", start);
			if (!newline)
				break;
			start = newline;
		}
	}

	return EXIT_FAILURE;
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Mini klogd implementation for busybox
4	*
5	* Copyright (C) 2001 by Gennady Feldman <gfeldman@gena01.com>.
6	* Changes: Made this a standalone busybox module which uses standalone
7	* syslog() client interface.
8	*
9	* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
10	*
11	* Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
12	*
13	* "circular buffer" Copyright (C) 2000 by Gennady Feldman <gfeldman@gena01.com>
14	*
15	* Maintainer: Gennady Feldman <gfeldman@gena01.com> as of Mar 12, 2001
16	*
17	* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
18	*/
19
20	#include "libbb.h"
21	#include <syslog.h>
22	#include <sys/klog.h>
23
24	static void klogd_signal(int sig)
25	{
26	/* FYI: cmd 7 is equivalent to setting console_loglevel to 7
27	* via klogctl(8, NULL, 7). */
28	klogctl(7, NULL, 0); /* "7 -- Enable printk's to console" */
29	klogctl(0, NULL, 0); /* "0 -- Close the log. Currently a NOP" */
30	syslog(LOG_NOTICE, "klogd: exiting");
31	kill_myself_with_sig(sig);
32	}
33
34	#define log_buffer bb_common_bufsiz1
35	enum {
36	KLOGD_LOGBUF_SIZE = sizeof(log_buffer),
37	OPT_LEVEL = (1 << 0),
38	OPT_FOREGROUND = (1 << 1),
39	};
40
41	int klogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
42	int klogd_main(int argc UNUSED_PARAM, char **argv)
43	{
44	int i = 0;
45	char *start;
46	int opt;
47	int used = 0;
48
49	opt = getopt32(argv, "c:n", &start);
50	if (opt & OPT_LEVEL) {
51	/* Valid levels are between 1 and 8 */
52	i = xatou_range(start, 1, 8);
53	}
54	if (!(opt & OPT_FOREGROUND)) {
55	bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
56	}
57
58	openlog("kernel", 0, LOG_KERN);
59
60	bb_signals(0
61	+ (1 << SIGINT)
62	+ (1 << SIGTERM)
63	, klogd_signal);
64	signal(SIGHUP, SIG_IGN);
65
66	/* "Open the log. Currently a NOP" */
67	klogctl(1, NULL, 0);
68
69	/* "printk() prints a message on the console only if it has a loglevel
70	* less than console_loglevel". Here we set console_loglevel = i. */
71	if (i)
72	klogctl(8, NULL, i);
73
74	syslog(LOG_NOTICE, "klogd started: %s", bb_banner);
75
76	while (1) {
77	int n;
78	int priority;
79
80	/* "2 -- Read from the log." */
81	n = klogctl(2, log_buffer + used, KLOGD_LOGBUF_SIZE-1 - used);
82	if (n < 0) {
83	if (errno == EINTR)
84	continue;
85	syslog(LOG_ERR, "klogd: error %d in klogctl(2): %m",
86	errno);
87	break;
88	}
89	log_buffer[used + n] = '\0';
90
91	/* klogctl buffer parsing modelled after code in dmesg.c */
92	start = &log_buffer[0];
93
94	/* Process each newline-terminated line in the buffer */
95	while (1) {
96	char *newline = strchr(start, '\n');
97
98	if (!newline) {
99	/* This line is incomplete... */
100	if (start != log_buffer) {
101	/* move it to the front of the buffer */
102	overlapping_strcpy(log_buffer, start);
103	/* don't log it yet */
104	used = strlen(log_buffer);
105	break;
106	}
107	/* ...but buffer is full, so log it anyway */
108	used = 0;
109	} else {
110	*newline++ = '\0';
111	}
112
113	/* Extract the priority */
114	priority = LOG_INFO;
115	if (*start == '<') {
116	start++;
117	if (*start) {
118	/* kernel never generates multi-digit prios */
119	priority = (*start - '0');
120	start++;
121	}
122	if (*start == '>') {
123	start++;
124	}
125	}
126	if (*start)
127	syslog(priority, "%s", start);
128	if (!newline)
129	break;
130	start = newline;
131	}
132	}
133
134	return EXIT_FAILURE;
135	}