/*
 * test kobject_uevent
 *   bushi@mizi.com
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <asm/types.h>
#include <sys/socket.h>
#include <linux/rtnetlink.h>
#include <linux/netlink.h>

#ifndef NETLINK_KOBJECT_UEVENT
#define NETLINK_KOBJECT_UEVENT (15)
#endif

int main(int argc, char **argv)
{
	int ret = EXIT_FAILURE;
	int ns = -1;
	struct sockaddr_nl sa;
	char buf[4096] __attribute__((aligned (8))); /* for non-x86 */
	struct iovec iov = { buf, sizeof(buf) };
	struct msghdr msg = { &sa, sizeof(sa), &iov, 1, NULL, 0, 0 };
	int len;

	memset (&sa, 0, sizeof(sa));
	sa.nl_family = AF_NETLINK;
	sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR;

	ns = socket(AF_NETLINK, SOCK_RAW, NETLINK_KOBJECT_UEVENT);
	if (ns < 0) {
		perror("socket()");
		goto sock_err;
	}
	if (bind(ns, (struct sockaddr*)&sa, sizeof(sa))) {
		perror("bind()");
		goto bind_err;
	}

	while (1) {
		len = recvmsg (ns, &msg, 0);
		if (len < 0) {
			perror("recvmsg()");
			break;
		}
		
		buf[4095] = 0;
		printf("%s\n", &buf[0]);
		fflush(stdout);

#if 0
		/* ... refer to 'man 7 netlink' */
		struct nlmsghdr *h;
		for (h = (struct nlmsghdr*)buf; NLMSG_OK(h, len);) {
			printf("nlmsg_len: %d\n", h->nlmsg_len);
			h = NLMSG_NEXT(h, len);
		}
#endif
	}

 bind_err:
	close(ns);

 sock_err:
	return ret;
}