mavlink.h

/*
  mavlink class for UDPProxy
 */
#pragma once

#include "mavlink_msgs.h"
#include "keydb.h"
#include "websocket.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

typedef ssize_t (*send_fn_t)(int, const void *, size_t , int);

/*
  abstraction for MAVLink on UDP
 */
class MAVLink {
public:
    void init(int fd, mavlink_channel_t chan, bool signing_required, bool allow_websocket, bool is_tcp, int key_id=-1);
    bool receive_message(uint8_t *&buf, ssize_t &len, mavlink_message_t &msg);
    bool send_message(const mavlink_message_t &msg);
    void set_ws(WebSocket *_ws) {
	ws = _ws;
    }
    void set_sendto(const struct sockaddr_in &_send_addr, socklen_t _send_len) {
	use_sendto = true;
	send_addr = _send_addr;
	send_len = _send_len;
    }

private:
    struct KeyEntry key;
    int fd;
    mavlink_channel_t chan;
    int key_id;
    bool is_tcp;
    bool key_loaded = false;
    bool got_signed_packet = false;
    static bool got_bad_signature[MAVLINK_COMM_NUM_BUFFERS];
    bool allow_websocket;
    bool use_sendto;
    struct sockaddr_in send_addr;
    socklen_t send_len;

    mavlink_signing_streams_t signing_streams {};
    mavlink_signing_t signing {};

    // last time we saved the timestamp
    double last_signing_save_s = 0;

    // last time we warned the support engineer to fix signing
    double last_signing_warning_s = 0;

    // last source sysid and compid from a HEARTBEAT from user
    uint8_t last_sysid, last_compid;

    // count of signature errors for triggering message
    uint32_t bad_sig_count = 0;

    void load_signing_key(void);
    void update_signing_timestamp(void);
    void save_signing_timestamp(void);
    bool load_key(TDB_CONTEXT *db);
    bool save_key(TDB_CONTEXT *db);

    bool periodic_warning(void);
    void mav_printf(uint8_t severity, const char *fmt, ...);
    static bool accept_unsigned_callback(const mavlink_status_t *status, uint32_t msgId);
    void handle_setup_signing(const mavlink_message_t &msg);

    ssize_t send_data(const void *buf, ssize_t len);

    WebSocket *ws;
};