protocol.h

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2019 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef __cplusplus
#error This header can only be compiled as C++.
#endif

#ifndef BITCOIN_PROTOCOL_H
#define BITCOIN_PROTOCOL_H

#include <netaddress.h>
#include <serialize.h>
#include <uint256.h>
#include <version.h>

#include <array>
#include <cstdint>
#include <string>

class Config;

static const unsigned int MAX_PROTOCOL_MESSAGE_LENGTH = 2 * 1024 * 1024;

class CMessageHeader {
public:
    static constexpr size_t MESSAGE_START_SIZE = 4;
    static constexpr size_t COMMAND_SIZE = 12;
    static constexpr size_t MESSAGE_SIZE_SIZE = 4;
    static constexpr size_t CHECKSUM_SIZE = 4;
    static constexpr size_t MESSAGE_SIZE_OFFSET =
        MESSAGE_START_SIZE + COMMAND_SIZE;
    static constexpr size_t CHECKSUM_OFFSET =
        MESSAGE_SIZE_OFFSET + MESSAGE_SIZE_SIZE;
    static constexpr size_t HEADER_SIZE =
        MESSAGE_START_SIZE + COMMAND_SIZE + MESSAGE_SIZE_SIZE + CHECKSUM_SIZE;
    typedef std::array<uint8_t, MESSAGE_START_SIZE> MessageMagic;

    explicit CMessageHeader(const MessageMagic &pchMessageStartIn);

    CMessageHeader(const MessageMagic &pchMessageStartIn,
                   const char *pszCommand, unsigned int nMessageSizeIn);

    std::string GetCommand() const;
    bool IsValid(const Config &config) const;
    bool IsValidWithoutConfig(const MessageMagic &magic) const;
    bool IsOversized(const Config &config) const;

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream &s, Operation ser_action) {
        READWRITE(pchMessageStart);
        READWRITE(pchCommand);
        READWRITE(nMessageSize);
        READWRITE(pchChecksum);
    }

    MessageMagic pchMessageStart;
    std::array<char, COMMAND_SIZE> pchCommand;
    uint32_t nMessageSize;
    uint8_t pchChecksum[CHECKSUM_SIZE];
};

namespace NetMsgType {

extern const char *VERSION;
extern const char *VERACK;
extern const char *ADDR;
extern const char *INV;
extern const char *GETDATA;
extern const char *MERKLEBLOCK;
extern const char *GETBLOCKS;
extern const char *GETHEADERS;
extern const char *TX;
extern const char *HEADERS;
extern const char *BLOCK;
extern const char *GETADDR;
extern const char *MEMPOOL;
extern const char *PING;
extern const char *PONG;
extern const char *NOTFOUND;
extern const char *FILTERLOAD;
extern const char *FILTERADD;
extern const char *FILTERCLEAR;
extern const char *SENDHEADERS;
extern const char *FEEFILTER;
extern const char *SENDCMPCT;
extern const char *CMPCTBLOCK;
extern const char *GETBLOCKTXN;
extern const char *BLOCKTXN;
extern const char *GETCFILTERS;
extern const char *CFILTER;
extern const char *GETCFHEADERS;
extern const char *CFHEADERS;
extern const char *GETCFCHECKPT;
extern const char *CFCHECKPT;
extern const char *AVAHELLO;
extern const char *AVAPOLL;
extern const char *AVARESPONSE;

bool IsBlockLike(const std::string &strCommand);
}; // namespace NetMsgType

const std::vector<std::string> &getAllNetMessageTypes();

enum ServiceFlags : uint64_t {
    // NOTE: When adding here, be sure to update serviceFlagToStr too
    // Nothing
    NODE_NONE = 0,
    // NODE_NETWORK means that the node is capable of serving the complete block
    // chain. It is currently set by all Bitcoin ABC non pruned nodes, and is
    // unset by SPV clients or other light clients.
    NODE_NETWORK = (1 << 0),
    // NODE_GETUTXO means the node is capable of responding to the getutxo
    // protocol request. Bitcoin ABC does not support this but a patch set
    // called Bitcoin XT does. See BIP 64 for details on how this is
    // implemented.
    NODE_GETUTXO = (1 << 1),
    // NODE_BLOOM means the node is capable and willing to handle bloom-filtered
    // connections. Bitcoin ABC nodes used to support this by default, without
    // advertising this bit, but no longer do as of protocol version 70011 (=
    // NO_BLOOM_VERSION)
    NODE_BLOOM = (1 << 2),
    // Bit 4 was NODE_XTHIN, removed in v0.22.12

    // Bit 5 was NODE_BITCOIN_CASH, removed in v0.22.8

    // NODE_COMPACT_FILTERS means the node will service basic block filter
    // requests.
    // See BIP157 and BIP158 for details on how this is implemented.
    NODE_COMPACT_FILTERS = (1 << 6),

    // NODE_NETWORK_LIMITED means the same as NODE_NETWORK with the limitation
    // of only serving the last 288 (2 day) blocks
    // See BIP159 for details on how this is implemented.
    NODE_NETWORK_LIMITED = (1 << 10),

    // The last non experimental service bit, helper for looping over the flags
    NODE_LAST_NON_EXPERIMENTAL_SERVICE_BIT = (1 << 23),

    // Bits 24-31 are reserved for temporary experiments. Just pick a bit that
    // isn't getting used, or one not being used much, and notify the
    // bitcoin-development mailing list. Remember that service bits are just
    // unauthenticated advertisements, so your code must be robust against
    // collisions and other cases where nodes may be advertising a service they
    // do not actually support. Other service bits should be allocated via the
    // BIP process.

    // NODE_AVALANCHE means the node supports Bitcoin Cash's avalanche
    // preconsensus mechanism.
    NODE_AVALANCHE = (1 << 24),
};

std::vector<std::string> serviceFlagsToStr(const uint64_t flags);

ServiceFlags GetDesirableServiceFlags(ServiceFlags services);

void SetServiceFlagsIBDCache(bool status);

static inline bool HasAllDesirableServiceFlags(ServiceFlags services) {
    return !(GetDesirableServiceFlags(services) & (~services));
}

static inline bool MayHaveUsefulAddressDB(ServiceFlags services) {
    return (services & NODE_NETWORK) || (services & NODE_NETWORK_LIMITED);
}

class CAddress : public CService {
public:
    CAddress();
    explicit CAddress(CService ipIn, ServiceFlags nServicesIn);

    void Init();

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream &s, Operation ser_action) {
        if (ser_action.ForRead()) {
            Init();
        }
        int nVersion = s.GetVersion();
        if (s.GetType() & SER_DISK) {
            READWRITE(nVersion);
        }
        if ((s.GetType() & SER_DISK) ||
            (nVersion != INIT_PROTO_VERSION && !(s.GetType() & SER_GETHASH))) {
            // The only time we serialize a CAddress object without nTime is in
            // the initial VERSION messages which contain two CAddress records.
            // At that point, the serialization version is INIT_PROTO_VERSION.
            // After the version handshake, serialization version is >=
            // MIN_PEER_PROTO_VERSION and all ADDR messages are serialized with
            // nTime.
            READWRITE(nTime);
        }
        uint64_t nServicesInt = nServices;
        READWRITE(nServicesInt);
        nServices = static_cast<ServiceFlags>(nServicesInt);
        READWRITEAS(CService, *this);
    }

    // TODO: make private (improves encapsulation)
public:
    ServiceFlags nServices;

    // disk and network only
    unsigned int nTime;
};

const uint32_t MSG_TYPE_MASK = 0xffffffff >> 3;

enum GetDataMsg {
    UNDEFINED = 0,
    MSG_TX = 1,
    MSG_BLOCK = 2,
    // The following can only occur in getdata. Invs always use TX or BLOCK.
    MSG_FILTERED_BLOCK = 3,
    MSG_CMPCT_BLOCK = 4,
};

class CInv {
public:
    // TODO: make private (improves encapsulation)
    uint32_t type;
    uint256 hash;

public:
    CInv() : type(0), hash() {}
    CInv(uint32_t typeIn, const uint256 &hashIn) : type(typeIn), hash(hashIn) {}

    ADD_SERIALIZE_METHODS;

    template <typename Stream, typename Operation>
    inline void SerializationOp(Stream &s, Operation ser_action) {
        READWRITE(type);
        READWRITE(hash);
    }

    friend bool operator<(const CInv &a, const CInv &b) {
        return a.type < b.type || (a.type == b.type && a.hash < b.hash);
    }

    std::string GetCommand() const;
    std::string ToString() const;

    uint32_t GetKind() const { return type & MSG_TYPE_MASK; }

    bool IsTx() const {
        auto k = GetKind();
        return k == MSG_TX;
    }

    bool IsSomeBlock() const {
        auto k = GetKind();
        return k == MSG_BLOCK || k == MSG_FILTERED_BLOCK ||
               k == MSG_CMPCT_BLOCK;
    }
};

#endif // BITCOIN_PROTOCOL_H