busybox/sysklogd/klogd.c
Denis Vlasenko e428e9d43b klogd: small optimizations
(btw, I looked into syslogd... that's frightening!)
2007-01-04 03:07:57 +00:00

125 lines
3.0 KiB
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 "busybox.h"
#include <sys/syslog.h>
#include <sys/klog.h>
static void klogd_signal(int sig ATTRIBUTE_UNUSED)
{
klogctl(7, NULL, 0);
klogctl(0, 0, 0);
syslog(LOG_NOTICE, "Kernel log daemon exiting");
exit(EXIT_SUCCESS);
}
#define OPT_LEVEL 1
#define OPT_FOREGROUND 2
#define KLOGD_LOGBUF_SIZE 4096
int klogd_main(int argc, char **argv)
{
RESERVE_CONFIG_BUFFER(log_buffer, KLOGD_LOGBUF_SIZE);
int console_log_level = console_log_level; /* for gcc */
int priority = LOG_INFO;
int i, n, lastc;
char *start;
/* do normal option parsing */
n = getopt32(argc, argv, "c:n", &start);
if (n & OPT_LEVEL) {
/* Valid levels are between 1 and 8 */
console_log_level = xatoul_range(start, 1, 8);
}
if (!(n & OPT_FOREGROUND)) {
#ifdef BB_NOMMU
vfork_daemon_rexec(0, 1, argc, argv, "-n");
#else
xdaemon(0, 1);
#endif
}
openlog("kernel", 0, LOG_KERN);
/* 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);
/* Set level of kernel console messaging.. */
if (n & OPT_LEVEL)
klogctl(8, NULL, console_log_level);
syslog(LOG_NOTICE, "klogd started: %s", BB_BANNER);
while (1) {
/* Use kernel syscalls */
memset(log_buffer, '\0', KLOGD_LOGBUF_SIZE);
/* It will be null-terminted */
n = klogctl(2, log_buffer, KLOGD_LOGBUF_SIZE - 1);
if (n < 0) {
if (errno == EINTR)
continue;
syslog(LOG_ERR, "klogd: error from klogctl(2): %d - %m",
errno);
break;
}
/* 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] == '<') {
i++;
// kernel never ganerates multi-digit prios
//priority = 0;
//while (log_buffer[i] >= '0' && log_buffer[i] <= '9') {
// priority = priority * 10 + (log_buffer[i] - '0');
// i++;
//}
if (isdigit(log_buffer[i])) {
priority = (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(priority, "%s", start);
start = &log_buffer[i + 1];
priority = LOG_INFO;
}
lastc = log_buffer[i];
}
}
if (ENABLE_FEATURE_CLEAN_UP)
RELEASE_CONFIG_BUFFER(log_buffer);
return EXIT_FAILURE;
}