int init_rcv_udp_socket(int lport)
static int init_rcv_udp_socket(int lport)
int init_rcv_udp_socket(int lport){	int s;        struct sockaddr_in serv_addr;	memset(&serv_addr, 0, sizeof(serv_addr));	serv_addr.sin_family = AF_INET;	serv_addr.sin_port = htons(lport);	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);	// create socket	if((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {		fprintf(stderr, "error opening socket\n");		return -1;	}	// bind to socket	if(bind(s, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {		perror ("bind failed");		return -1;	}	return s;}