addrman_impl.h

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// Copyright (c) 2021 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 BITCOIN_ADDRMAN_IMPL_H
#define BITCOIN_ADDRMAN_IMPL_H
 
#include <logging.h>
#include <logging/timer.h>
#include <netaddress.h>
#include <protocol.h>
#include <serialize.h>
#include <sync.h>
#include <timedata.h>
#include <uint256.h>
#include <util/time.h>
 
#include <cstdint>
#include <optional>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
 
static constexpr int32_t ADDRMAN_TRIED_BUCKET_COUNT_LOG2{8};
static constexpr int ADDRMAN_TRIED_BUCKET_COUNT{
    1 << ADDRMAN_TRIED_BUCKET_COUNT_LOG2};
 
static constexpr int32_t ADDRMAN_NEW_BUCKET_COUNT_LOG2{10};
static constexpr int ADDRMAN_NEW_BUCKET_COUNT{1
                                              << ADDRMAN_NEW_BUCKET_COUNT_LOG2};
 
static constexpr int32_t ADDRMAN_BUCKET_SIZE_LOG2{6};
static constexpr int ADDRMAN_BUCKET_SIZE{1 << ADDRMAN_BUCKET_SIZE_LOG2};
 
class AddrInfo : public CAddress {
public:
    NodeSeconds m_last_try{0s};
 
    NodeSeconds m_last_count_attempt{0s};
 
    CNetAddr source;
 
    NodeSeconds m_last_success{0s};
 
    int nAttempts{0};
 
    int nRefCount{0};
 
    bool fInTried{false};
 
    mutable int nRandomPos{-1};
 
    SERIALIZE_METHODS(AddrInfo, obj) {
        READWRITEAS(CAddress, obj);
        READWRITE(obj.source,
                  Using<ChronoFormatter<int64_t>>(obj.m_last_success),
                  obj.nAttempts);
    }
 
    AddrInfo(const CAddress &addrIn, const CNetAddr &addrSource)
        : CAddress(addrIn), source(addrSource) {}
 
    AddrInfo() : CAddress(), source() {}
 
    int GetTriedBucket(const uint256 &nKey,
                       const std::vector<bool> &asmap) const;
 
    int GetNewBucket(const uint256 &nKey, const CNetAddr &src,
                     const std::vector<bool> &asmap) const;
 
    int GetNewBucket(const uint256 &nKey,
                     const std::vector<bool> &asmap) const {
        return GetNewBucket(nKey, source, asmap);
    }
 
    int GetBucketPosition(const uint256 &nKey, bool fNew, int nBucket) const;
 
    bool IsTerrible(NodeSeconds now = Now<NodeSeconds>()) const;
 
    double GetChance(NodeSeconds now = Now<NodeSeconds>()) const;
};
 
class AddrManImpl {
public:
    AddrManImpl(std::vector<bool> &&asmap, int32_t consistency_check_ratio);
 
    ~AddrManImpl();
 
    template <typename Stream>
    void Serialize(Stream &s_) const EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    template <typename Stream>
    void Unserialize(Stream &s_) EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    size_t size() const EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    bool Add(const std::vector<CAddress> &vAddr, const CNetAddr &source,
             std::chrono::seconds time_penalty) EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    void Good(const CService &addr, bool test_before_evict, NodeSeconds time)
        EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    void Attempt(const CService &addr, bool fCountFailure, NodeSeconds time)
        EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    void ResolveCollisions() EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    std::pair<CAddress, NodeSeconds> SelectTriedCollision()
        EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    std::pair<CAddress, NodeSeconds> Select(bool newOnly) const
        EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    std::vector<CAddress> GetAddr(size_t max_addresses, size_t max_pct,
                                  std::optional<Network> network) const
        EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    void Connected(const CService &addr, NodeSeconds time)
        EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    void SetServices(const CService &addr, ServiceFlags nServices)
        EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    const std::vector<bool> &GetAsmap() const;
 
    void Clear() EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    void MakeDeterministic() EXCLUSIVE_LOCKS_REQUIRED(!cs);
 
    friend class AddrManTest;
    friend class AddrManCorrupted;
 
private:
    mutable Mutex cs;
 
    mutable FastRandomContext insecure_rand;
 
    uint256 nKey;
 
    enum Format : uint8_t {
        V0_HISTORICAL = 0,
        V1_DETERMINISTIC = 1,
        V2_ASMAP = 2,
        V3_BIP155 = 3,
        V4_MULTIPORT = 4,
    };
 
    static constexpr Format FILE_FORMAT = Format::V4_MULTIPORT;
 
    static constexpr uint8_t INCOMPATIBILITY_BASE = 32;
 
    int nIdCount GUARDED_BY(cs);
 
    std::unordered_map<int, AddrInfo> mapInfo GUARDED_BY(cs);
 
    std::unordered_map<CService, int, CServiceHash> mapAddr GUARDED_BY(cs);
 
    mutable std::vector<int> vRandom GUARDED_BY(cs);
 
    // number of "tried" entries
    int nTried GUARDED_BY(cs);
 
    int vvTried[ADDRMAN_TRIED_BUCKET_COUNT][ADDRMAN_BUCKET_SIZE] GUARDED_BY(cs);
 
    int nNew GUARDED_BY(cs);
 
    int vvNew[ADDRMAN_NEW_BUCKET_COUNT][ADDRMAN_BUCKET_SIZE] GUARDED_BY(cs);
 
    NodeSeconds m_last_good GUARDED_BY(cs);
 
    std::set<int> m_tried_collisions;
 
    const int32_t m_consistency_check_ratio;
 
    // Compressed IP->ASN mapping, loaded from a file when a node starts.
    // Should be always empty if no file was provided.
    // This mapping is then used for bucketing nodes in Addrman.
    //
    // If asmap is provided, nodes will be bucketed by
    // AS they belong to, in order to make impossible for a node
    // to connect to several nodes hosted in a single AS.
    // This is done in response to Erebus attack, but also to generally
    // diversify the connections every node creates,
    // especially useful when a large fraction of nodes
    // operate under a couple of cloud providers.
    //
    // If a new asmap was provided, the existing records
    // would be re-bucketed accordingly.
    const std::vector<bool> m_asmap;
 
    bool deterministic = false;
 
    AddrInfo *Find(const CService &addr, int *pnId = nullptr)
        EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    AddrInfo *Create(const CAddress &addr, const CNetAddr &addrSource,
                     int *pnId = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    void SwapRandom(unsigned int nRandomPos1, unsigned int nRandomPos2) const
        EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    void Delete(int nId) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    void ClearNew(int nUBucket, int nUBucketPos) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    void MakeTried(AddrInfo &info, int nId) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    bool AddSingle(const CAddress &addr, const CNetAddr &source,
                   std::chrono::seconds time_penalty)
        EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    void Good_(const CService &addr, bool test_before_evict, NodeSeconds time)
        EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    bool Add_(const std::vector<CAddress> &vAddr, const CNetAddr &source,
              std::chrono::seconds time_penalty) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    void Attempt_(const CService &addr, bool fCountFailure, NodeSeconds time)
        EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    std::pair<CAddress, NodeSeconds> Select_(bool newOnly) const
        EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    std::vector<CAddress> GetAddr_(size_t max_addresses, size_t max_pct,
                                   std::optional<Network> network) const
        EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    void Connected_(const CService &addr, NodeSeconds time)
        EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    void SetServices_(const CService &addr, ServiceFlags nServices)
        EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    void ResolveCollisions_() EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    std::pair<CAddress, NodeSeconds> SelectTriedCollision_()
        EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    void Check() const EXCLUSIVE_LOCKS_REQUIRED(cs);
 
    int CheckAddrman() const EXCLUSIVE_LOCKS_REQUIRED(cs);
};
 
#endif // BITCOIN_ADDRMAN_IMPL_H