1/* vi: set sw=4 ts=4: */
2/*
3 * Mini klogd implementation for busybox
4 *
5 * Copyright (C) 2001 by Gennady Feldman <gfeldman@cachier.com>.
6 * Changes: Made this a standalone busybox module which uses standalone
7 * 					syslog() client interface.
8 *
9 * Copyright (C) 1999,2000,2001 by Lineo, inc.
10 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
11 *
12 * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
13 *
14 * "circular buffer" Copyright (C) 2000 by Gennady Feldman <gfeldman@mail.com>
15 *
16 * Maintainer: Gennady Feldman <gena01@cachier.com> as of Mar 12, 2001
17 *
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation; either version 2 of the License, or
21 * (at your option) any later version.
22 *
23 * This program is distributed in the hope that it will be useful,
24 * but WITHOUT ANY WARRANTY; without even the implied warranty of
25 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
26 * General Public License for more details.
27 *
28 * You should have received a copy of the GNU General Public License
29 * along with this program; if not, write to the Free Software
30 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
31 *
32 */
33
34#include <stdio.h>
35#include <stdlib.h>
36#include <signal.h> /* for our signal() handlers */
37#include <string.h> /* strncpy() */
38#include <errno.h>  /* errno and friends */
39#include <unistd.h>
40#include <ctype.h>
41#include <sys/syslog.h>
42
43#if __GNU_LIBRARY__ < 5
44# ifdef __alpha__
45#   define klogctl syslog
46# endif
47#else
48# include <sys/klog.h>
49#endif
50
51#include "busybox.h"
52
53static void klogd_signal(int sig)
54{
55	klogctl(7, NULL, 0);
56	klogctl(0, 0, 0);
57	//logMessage(0, "Kernel log daemon exiting.");
58	syslog_msg(LOG_DAEMON, 0, "Kernel log daemon exiting.");
59	exit(TRUE);
60}
61
62static void doKlogd (void) __attribute__ ((noreturn));
63static void doKlogd (void)
64{
65	int priority = LOG_INFO;
66	char log_buffer[4096];
67	int i, n, lastc;
68	char *start;
69
70	/* Set up sig handlers */
71	signal(SIGINT, klogd_signal);
72	signal(SIGKILL, klogd_signal);
73	signal(SIGTERM, klogd_signal);
74	signal(SIGHUP, SIG_IGN);
75
76	/* "Open the log. Currently a NOP." */
77	klogctl(1, NULL, 0);
78
79	syslog_msg(LOG_DAEMON, 0, "klogd started: " BB_BANNER);
80
81	while (1) {
82		/* Use kernel syscalls */
83		memset(log_buffer, '\0', sizeof(log_buffer));
84		n = klogctl(2, log_buffer, sizeof(log_buffer));
85		if (n < 0) {
86			char message[80];
87
88			if (errno == EINTR)
89				continue;
90			snprintf(message, 79, "klogd: Error return from sys_sycall: %d - %s.\n", 
91												errno, strerror(errno));
92			syslog_msg(LOG_DAEMON, LOG_SYSLOG | LOG_ERR, message);
93			exit(1);
94		}
95
96		/* klogctl buffer parsing modelled after code in dmesg.c */
97		start=&log_buffer[0];
98		lastc='\0';
99		for (i=0; i<n; i++) {
100			if (lastc == '\0' && log_buffer[i] == '<') {
101				priority = 0;
102				i++;
103				while (isdigit(log_buffer[i])) {
104					priority = priority*10+(log_buffer[i]-'0');
105					i++;
106				}
107				if (log_buffer[i] == '>') i++;
108				start = &log_buffer[i];
109			}
110			if (log_buffer[i] == '\n') {
111				log_buffer[i] = '\0';  /* zero terminate this message */
112				syslog_msg(LOG_DAEMON, LOG_KERN | priority, start);
113				start = &log_buffer[i+1];
114				priority = LOG_INFO;
115			}
116			lastc = log_buffer[i];
117		}
118	}
119}
120
121extern int klogd_main(int argc, char **argv)
122{
123	/* no options, no getopt */
124	int opt;
125	int doFork = TRUE;
126
127	/* do normal option parsing */
128	while ((opt = getopt(argc, argv, "n")) > 0) {
129		switch (opt) {
130			case 'n':
131				doFork = FALSE;
132				break;
133			default:
134				show_usage();
135		}
136	}
137
138	if (doFork == TRUE) {
139		if (daemon(0, 1) < 0)
140			perror_msg_and_die("daemon");
141	}
142	doKlogd();
143	
144	return EXIT_SUCCESS;
145}
146
147/*
148Local Variables
149c-file-style: "linux"
150c-basic-offset: 4
151tab-width: 4
152End:
153*/
154