////  NLPacket.h//  libraries/networking/src////  Created by Clement on 7/6/15.//  Copyright 2015 High Fidelity, Inc.//  Copyright 2021 Vircadia contributors.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html// #ifndef hifi_NLPacket_h#define hifi_NLPacket_h #include <UUID.h> #include "udt/Packet.h" class HMACAuth; class NLPacket : public udt::Packet {    Q_OBJECTpublic:    //    //    NLPacket format:    //    //    |      BYTE     |      BYTE     |      BYTE     |      BYTE     |    //     0                   1                   2                   3    //     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1    //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    //    |  Packet Type  |    Version    | Local Node ID - sourced only  |    //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    //    |                                                               |    //    |                 MD5 Verification - 16 bytes                   |    //    |                 (ONLY FOR VERIFIED PACKETS)                   |    //    |                                                               |    //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    //     using LocalID = NetworkLocalID;    static const LocalID NULL_LOCAL_ID = 0;        static const int NUM_BYTES_LOCALID = sizeof(LocalID);    // this is used by the Octree classes - must be known at compile time    static const int MAX_PACKET_HEADER_SIZE =        sizeof(udt::Packet::SequenceNumberAndBitField) + sizeof(udt::Packet::MessageNumberAndBitField) +        sizeof(PacketType) + sizeof(PacketVersion) + NUM_BYTES_LOCALID + NUM_BYTES_MD5_HASH;        static std::unique_ptr<NLPacket> create(PacketType type, qint64 size = -1,                    bool isReliable = false, bool isPartOfMessage = false, PacketVersion version = 0);        static std::unique_ptr<NLPacket> fromReceivedPacket(std::unique_ptr<char[]> data, qint64 size,                                                        const SockAddr& senderSockAddr);     static std::unique_ptr<NLPacket> fromBase(std::unique_ptr<Packet> packet);        // Provided for convenience, try to limit use    static std::unique_ptr<NLPacket> createCopy(const NLPacket& other);        // Current level's header size    static int localHeaderSize(PacketType type);    // Cumulated size of all the headers    static int totalHeaderSize(PacketType type, bool isPartOfMessage = false);    // The maximum payload size this packet can use to fit in MTU    static int maxPayloadSize(PacketType type, bool isPartOfMessage = false);        static PacketType typeInHeader(const udt::Packet& packet);    static PacketVersion versionInHeader(const udt::Packet& packet);        static LocalID sourceIDInHeader(const udt::Packet& packet);    static QByteArray verificationHashInHeader(const udt::Packet& packet);    static QByteArray hashForPacketAndHMAC(const udt::Packet& packet, HMACAuth& hash);        PacketType getType() const { return _type; }    void setType(PacketType type);        PacketVersion getVersion() const { return _version; }    void setVersion(PacketVersion version);     LocalID getSourceID() const { return _sourceID; }        void writeSourceID(LocalID sourceID) const;    void writeVerificationHash(HMACAuth& hmacAuth) const; protected:        NLPacket(PacketType type, qint64 size = -1, bool forceReliable = false, bool isPartOfMessage = false, PacketVersion version = 0);    NLPacket(std::unique_ptr<char[]> data, qint64 size, const SockAddr& senderSockAddr);        NLPacket(const NLPacket& other);    NLPacket(NLPacket&& other);    NLPacket(Packet&& other);        NLPacket& operator=(const NLPacket& other);    NLPacket& operator=(NLPacket&& other);        // Header writers    void writeTypeAndVersion();     // Header readers, used to set member variables after getting a packet from the network    void readType();    void readVersion();    void readSourceID();        PacketType _type;    PacketVersion _version;    mutable LocalID _sourceID;}; #endif // hifi_NLPacket_h