typedef struct {
	dhtid sender;
	dhtid dest;
	char *protocol
	int len;
	char *body;
} message;

typedef void (*message_handler) (message *m);

void dhtd_bind(char *protocol, message_handler *handler);
void dhtd_send_to(ipaddr_t address, short port, message *msg);
void dhtd_send(message *msg, int num);