extern void forward_request(struct connection_t *c, const char *request);
extern bool receive_request(struct connection_t *c, const char *request);
extern void forward_request(struct connection_t *c, const char *request);
extern bool receive_request(struct connection_t *c, const char *request);
extern bool send_req_key(struct node_t *to);
extern bool send_ans_key(struct node_t *to);
extern bool send_tcppacket(struct connection_t *c, const struct vpn_packet_t *packet);
extern bool send_req_key(struct node_t *to);
extern bool send_ans_key(struct node_t *to);
extern bool send_tcppacket(struct connection_t *c, const struct vpn_packet_t *packet);
extern bool send_udp_info(struct node_t *from, struct node_t *to);
extern bool send_mtu_info(struct node_t *from, struct node_t *to, int mtu);
extern bool send_udp_info(struct node_t *from, struct node_t *to);
extern bool send_mtu_info(struct node_t *from, struct node_t *to, int mtu);