source: MondoRescue/branches/2.2.5/mindi-busybox/sysklogd/klogd.c@ 2142

/* 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 <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 BUFSIZ
#define log_buffer bb_common_bufsiz1

int klogd_main(int argc, char **argv);
int klogd_main(int argc, char **argv)
{
    int i = i; /* silence gcc */
    char *start;

    /* do normal option parsing */
    getopt32(argv, "c:n", &start);

    if (option_mask32 & OPT_LEVEL) {
        /* Valid levels are between 1 and 8 */
        i = xatoul_range(start, 1, 8);
    }

    if (!(option_mask32 & OPT_FOREGROUND)) {
        bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
    }

    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 (option_mask32 & OPT_LEVEL)
        klogctl(8, NULL, i);

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

    /* Note: this code does not detect incomplete messages
     * (messages not ending with '\n' or just when kernel
     * generates too many messages for us to keep up)
     * and will split them in two separate lines */
    while (1) {
        int n;
        int priority;

        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;
        }
        log_buffer[n] = '\n';
        i = 0;
        while (i < n) {
            priority = LOG_INFO;
            start = &log_buffer[i];
            if (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];
            }
            while (log_buffer[i] != '\n')
                i++;
            log_buffer[i] = '\0';
            syslog(priority, "%s", start);
            i++;
        }
    }

    return EXIT_FAILURE;
}