ZeroTierOne/node/IncomingPacket.hpp

/*
 * Copyright (c)2013-2020 ZeroTier, Inc.
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file in the project's root directory.
 *
 * Change Date: 2026-01-01
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2.0 of the Apache License.
 */
/****/

#ifndef ZT_INCOMINGPACKET_HPP
#define ZT_INCOMINGPACKET_HPP

#include "MulticastGroup.hpp"
#include "Packet.hpp"
#include "Path.hpp"
#include "Peer.hpp"
#include "Utils.hpp"

#include <stdexcept>

/*
 * The big picture:
 *
 * tryDecode gets called for a given fully-assembled packet until it returns
 * true or the packet's time to live has been exceeded, in which case it is
 * discarded as failed decode. Any exception thrown by tryDecode also causes
 * the packet to be discarded.
 *
 * Thus a return of false from tryDecode() indicates that it should be called
 * again. Logic is very simple as to when, and it's in doAnythingWaitingForPeer
 * in Switch. This might be expanded to be more fine grained in the future.
 *
 * A return value of true indicates that the packet is done. tryDecode must
 * never be called again after that.
 */

namespace ZeroTier {

class RuntimeEnvironment;
class Network;

/**
 * Subclass of packet that handles the decoding of it
 */
class IncomingPacket : public Packet {
  public:
    IncomingPacket() : Packet(), _receiveTime(0), _path(), _authenticated(false)
    {
    }

    /**
     * Create a new packet-in-decode
     *
     * @param data Packet data
     * @param len Packet length
     * @param path Path over which packet arrived
     * @param now Current time
     * @throws std::out_of_range Range error processing packet
     */
    IncomingPacket(const void* data, unsigned int len, const SharedPtr<Path>& path, int64_t now) : Packet(data, len), _receiveTime(now), _path(path), _authenticated(false)
    {
    }

    /**
     * Init packet-in-decode in place
     *
     * @param data Packet data
     * @param len Packet length
     * @param path Path over which packet arrived
     * @param now Current time
     * @throws std::out_of_range Range error processing packet
     */
    inline void init(const void* data, unsigned int len, const SharedPtr<Path>& path, int64_t now)
    {
        copyFrom(data, len);
        _receiveTime = now;
        _path = path;
        _authenticated = false;
    }

    /**
     * Attempt to decode this packet
     *
     * Note that this returns 'true' if processing is complete. This says nothing
     * about whether the packet was valid. A rejection is 'complete.'
     *
     * Once true is returned, this must not be called again. The packet's state
     * may no longer be valid.
     *
     * @param RR Runtime environment
     * @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call
     * @return True if decoding and processing is complete, false if caller should try again
     */
    bool tryDecode(const RuntimeEnvironment* RR, void* tPtr, int32_t flowId);

    /**
     * @return Time of packet receipt / start of decode
     */
    inline uint64_t receiveTime() const
    {
        return _receiveTime;
    }

  private:
    // These are called internally to handle packet contents once it has
    // been authenticated, decrypted, decompressed, and classified.
    bool _doERROR(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doHELLO(const RuntimeEnvironment* RR, void* tPtr, const bool alreadyAuthenticated);
    bool _doACK(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doQOS_MEASUREMENT(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doOK(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doWHOIS(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doRENDEZVOUS(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doFRAME(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer, int32_t flowId);
    bool _doEXT_FRAME(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer, int32_t flowId);
    bool _doECHO(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doMULTICAST_LIKE(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doNETWORK_CREDENTIALS(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doNETWORK_CONFIG_REQUEST(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doNETWORK_CONFIG(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doMULTICAST_GATHER(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doMULTICAST_FRAME(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doPUSH_DIRECT_PATHS(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doUSER_MESSAGE(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doREMOTE_TRACE(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);
    bool _doPATH_NEGOTIATION_REQUEST(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer);

    void _sendErrorNeedCredentials(const RuntimeEnvironment* RR, void* tPtr, const SharedPtr<Peer>& peer, const uint64_t nwid);

    uint64_t _receiveTime;
    SharedPtr<Path> _path;
    bool _authenticated;
};

}   // namespace ZeroTier

#endif