struct sockaddr_in  srvaddr;
	struct sockaddr_in  cliaddr;
	struct msghdr       msg;
	union control_data  cmsg;
	struct iovec        iov[1];
	char                buf[1024];

	int sock = socket(AF_INET, SOCK_DGRAM, 0);
	if (sock == -1) DLOG_PF("socket: %1",errno);
	int sockopt = 1;
	//if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &sockopt, sizeof(sockopt)) == -1) DLOG_PF("setsockopt 1: %1", errno);
	if (setsockopt(sock, IPPROTO_IP, IP_PKTINFO, &sockopt, sizeof(sockopt)) == -1) DLOG_PF("setsockopt 3: %1", errno);

	memset(&srvaddr, 0, sizeof srvaddr);
	srvaddr.sin_family      = AF_INET;
	srvaddr.sin_addr.s_addr = htonl(INADDR_ANY);
	srvaddr.sin_port        = htons(MDK_CMD_UDP_PORT);
	if (bind(sock, (struct sockaddr *)&srvaddr, sizeof srvaddr) == -1) DLOG_PF("bind: %1", errno);

	iov[0].iov_base = buf;
	iov[0].iov_len  = sizeof buf;
	memset(&msg, 0, sizeof msg);
	msg.msg_name       = &cliaddr;
	msg.msg_namelen    = sizeof cliaddr;
	msg.msg_iov        = iov;
	msg.msg_iovlen     = 1;
	msg.msg_control    = &cmsg;
	msg.msg_controllen = sizeof cmsg;

	for (;;)
	{
		ssize_t nbytes = recvmsg(sock, &msg, 0);
		if (nbytes == -1) { DLOG_PF("recvmsg: %1", errno); }

		for(cmsghdr *cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg))
		{
			if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_PKTINFO)
			{
				in_pktinfo *pkt_info = (in_pktinfo*)CMSG_DATA(cmsg);
				DLOG_PF("recvmsg info: %1 %2 %3",
						pkt_info->ipi_addr.s_addr,
						pkt_info->ipi_spec_dst.s_addr,
						pkt_info->ipi_ifindex);
			}
		}
	}