hush/sysklogd/klogd.c
2001-03-14 01:15:06 +00:00

173 lines
4.2 KiB
C

/* 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) 1999,2000,2001 by Lineo, inc.
* Written by Erik Andersen <andersen@lineo.com>, <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 ! defined __GLIBC__ && ! defined __UCLIBC__
#include <sys/syscall.h>
#include <linux/unistd.h>
#ifndef __alpha__
# define __NR_klogctl __NR_syslog
static inline _syscall3(int, klogctl, int, type, char *, b, int, len);
#else /* __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: BusyBox v" BB_VER " (" BB_BT ")");
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];
}
}
}
static void daemon_init (char **argv, char *dz, void fn (void))
{
setsid(); /* start a new session? */
strncpy(argv[0], dz, strlen(argv[0]));
fn();
exit(0);
}
extern int klogd_main(int argc, char **argv)
{
/* no options, no getopt */
int opt, pid;
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 == TRUE) {
pid = fork();
if (pid < 0)
exit(pid);
else if (pid == 0) {
daemon_init (argv, "klogd", doKlogd);
}
} else {
doKlogd();
}
return EXIT_SUCCESS;
}
/*
Local Variables
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/