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 <sys/syslog.h>
22#include <sys/klog.h>
23
24static void klogd_signal(int sig ATTRIBUTE_UNUSED)
25{
26	klogctl(7, NULL, 0);
27	klogctl(0, 0, 0);
28	syslog(LOG_NOTICE, "Kernel log daemon exiting");
29	exit(EXIT_SUCCESS);
30}
31
32#define OPT_LEVEL        1
33#define OPT_FOREGROUND   2
34
35#define KLOGD_LOGBUF_SIZE BUFSIZ
36#define log_buffer bb_common_bufsiz1
37
38int klogd_main(int argc, char **argv);
39int klogd_main(int argc, char **argv)
40{
41	int i = i; /* silence gcc */
42	char *start;
43
44	/* do normal option parsing */
45	getopt32(argv, "c:n", &start);
46
47	if (option_mask32 & OPT_LEVEL) {
48		/* Valid levels are between 1 and 8 */
49		i = xatoul_range(start, 1, 8);
50	}
51
52	if (!(option_mask32 & OPT_FOREGROUND)) {
53		bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
54	}
55
56	openlog("kernel", 0, LOG_KERN);
57
58	/* Set up sig handlers */
59	signal(SIGINT, klogd_signal);
60	signal(SIGKILL, klogd_signal);
61	signal(SIGTERM, klogd_signal);
62	signal(SIGHUP, SIG_IGN);
63
64	/* "Open the log. Currently a NOP." */
65	klogctl(1, NULL, 0);
66
67	/* Set level of kernel console messaging. */
68	if (option_mask32 & OPT_LEVEL)
69		klogctl(8, NULL, i);
70
71	syslog(LOG_NOTICE, "klogd started: %s", bb_banner);
72
73	/* Note: this code does not detect incomplete messages
74	 * (messages not ending with '\n' or just when kernel
75	 * generates too many messages for us to keep up)
76	 * and will split them in two separate lines */
77	while (1) {
78		int n;
79		int priority;
80
81		n = klogctl(2, log_buffer, KLOGD_LOGBUF_SIZE - 1);
82		if (n < 0) {
83			if (errno == EINTR)
84				continue;
85			syslog(LOG_ERR, "klogd: error from klogctl(2): %d - %m",
86					errno);
87			break;
88		}
89		log_buffer[n] = '\n';
90		i = 0;
91		while (i < n) {
92			priority = LOG_INFO;
93			start = &log_buffer[i];
94			if (log_buffer[i] == '<') {
95				i++;
96				// kernel never ganerates multi-digit prios
97				//priority = 0;
98				//while (log_buffer[i] >= '0' && log_buffer[i] <= '9') {
99				//	priority = priority * 10 + (log_buffer[i] - '0');
100				//	i++;
101				//}
102				if (isdigit(log_buffer[i])) {
103					priority = (log_buffer[i] - '0');
104					i++;
105				}
106				if (log_buffer[i] == '>')
107					i++;
108				start = &log_buffer[i];
109			}
110			while (log_buffer[i] != '\n')
111				i++;
112			log_buffer[i] = '\0';
113			syslog(priority, "%s", start);
114			i++;
115		}
116	}
117
118	return EXIT_FAILURE;
119}
120