/* nanoklogd - forward kernel messages to /dev/log.  */

/* Written by Christian Neukirchen <chneukirchen@gmail.com>
   To the extent possible under law, the creator of this work has waived
   all copyright and related or neighboring rights to this work.  */

/* This uses /dev/log directly because glibc syslog(3) does
   forward LOG_KERN as LOG_USER.  */

#include <sys/klog.h>
#include <sys/socket.h>
#include <errno.h>
#include <unistd.h>

static const struct {
        short sun_family;
        char sun_path[9];
} log_addr = {
        AF_UNIX,
        "/dev/log"
};

int
main(int argc, char *argv[]) {
	char buf[16384];
	int f, l;

	f = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
	if (f < 0)
		return 111;

	if (connect(f, (void *)&log_addr, sizeof log_addr) < 0)
		return 112;

	while (1) {
		l = klogctl(2, buf, sizeof buf);
		if (l < 0)
			return 113;

		while (send(f, buf, l, 0) != l)
			switch (errno) {
			case ECONNREFUSED:
			case ECONNRESET:
			case ENOTCONN:
				/* syslogd went down, retry until up.  */
				close(f);
				sleep(1);
				f = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
				if (f < 0)
					return 111;
				connect(f, (void *)&log_addr, sizeof log_addr);
				break;
			default:
				return 114;
			}
	}
	return 0;
}