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Diffstat (limited to 'src/addrman_impl.h')
| -rw-r--r-- | src/addrman_impl.h | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/src/addrman_impl.h b/src/addrman_impl.h new file mode 100644 index 0000000000..1dc7f25f9c --- /dev/null +++ b/src/addrman_impl.h @@ -0,0 +1,271 @@ +// 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 <netaddress.h> +#include <protocol.h> +#include <serialize.h> +#include <sync.h> +#include <uint256.h> + +#include <cstdint> +#include <optional> +#include <set> +#include <unordered_map> +#include <unordered_set> +#include <utility> +#include <vector> + +/** Total number of buckets for tried addresses */ +static constexpr int32_t ADDRMAN_TRIED_BUCKET_COUNT_LOG2{8}; +static constexpr int ADDRMAN_TRIED_BUCKET_COUNT{1 << ADDRMAN_TRIED_BUCKET_COUNT_LOG2}; +/** Total number of buckets for new addresses */ +static constexpr int32_t ADDRMAN_NEW_BUCKET_COUNT_LOG2{10}; +static constexpr int ADDRMAN_NEW_BUCKET_COUNT{1 << ADDRMAN_NEW_BUCKET_COUNT_LOG2}; +/** Maximum allowed number of entries in buckets for new and tried addresses */ +static constexpr int32_t ADDRMAN_BUCKET_SIZE_LOG2{6}; +static constexpr int ADDRMAN_BUCKET_SIZE{1 << ADDRMAN_BUCKET_SIZE_LOG2}; + +/** + * Extended statistics about a CAddress + */ +class AddrInfo : public CAddress +{ +public: + //! last try whatsoever by us (memory only) + int64_t nLastTry{0}; + + //! last counted attempt (memory only) + int64_t nLastCountAttempt{0}; + + //! where knowledge about this address first came from + CNetAddr source; + + //! last successful connection by us + int64_t nLastSuccess{0}; + + //! connection attempts since last successful attempt + int nAttempts{0}; + + //! reference count in new sets (memory only) + int nRefCount{0}; + + //! in tried set? (memory only) + bool fInTried{false}; + + //! position in vRandom + mutable int nRandomPos{-1}; + + SERIALIZE_METHODS(AddrInfo, obj) + { + READWRITEAS(CAddress, obj); + READWRITE(obj.source, obj.nLastSuccess, obj.nAttempts); + } + + AddrInfo(const CAddress &addrIn, const CNetAddr &addrSource) : CAddress(addrIn), source(addrSource) + { + } + + AddrInfo() : CAddress(), source() + { + } + + //! Calculate in which "tried" bucket this entry belongs + int GetTriedBucket(const uint256 &nKey, const std::vector<bool> &asmap) const; + + //! Calculate in which "new" bucket this entry belongs, given a certain source + int GetNewBucket(const uint256 &nKey, const CNetAddr& src, const std::vector<bool> &asmap) const; + + //! Calculate in which "new" bucket this entry belongs, using its default source + int GetNewBucket(const uint256 &nKey, const std::vector<bool> &asmap) const + { + return GetNewBucket(nKey, source, asmap); + } + + //! Calculate in which position of a bucket to store this entry. + int GetBucketPosition(const uint256 &nKey, bool fNew, int nBucket) const; + + //! Determine whether the statistics about this entry are bad enough so that it can just be deleted + bool IsTerrible(int64_t nNow = GetAdjustedTime()) const; + + //! Calculate the relative chance this entry should be given when selecting nodes to connect to + double GetChance(int64_t nNow = GetAdjustedTime()) const; +}; + +class AddrManImpl +{ +public: + AddrManImpl(std::vector<bool>&& asmap, bool deterministic, 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, int64_t nTimePenalty) + EXCLUSIVE_LOCKS_REQUIRED(!cs); + + void Good(const CService& addr, int64_t nTime) + EXCLUSIVE_LOCKS_REQUIRED(!cs); + + void Attempt(const CService& addr, bool fCountFailure, int64_t nTime) + EXCLUSIVE_LOCKS_REQUIRED(!cs); + + void ResolveCollisions() EXCLUSIVE_LOCKS_REQUIRED(!cs); + + std::pair<CAddress, int64_t> SelectTriedCollision() EXCLUSIVE_LOCKS_REQUIRED(!cs); + + std::pair<CAddress, int64_t> 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, int64_t nTime) + EXCLUSIVE_LOCKS_REQUIRED(!cs); + + void SetServices(const CService& addr, ServiceFlags nServices) + EXCLUSIVE_LOCKS_REQUIRED(!cs); + + const std::vector<bool>& GetAsmap() const; + + friend class AddrManTest; + friend class AddrManDeterministic; + +private: + //! A mutex to protect the inner data structures. + mutable Mutex cs; + + //! Source of random numbers for randomization in inner loops + mutable FastRandomContext insecure_rand GUARDED_BY(cs); + + //! secret key to randomize bucket select with + uint256 nKey; + + //! Serialization versions. + enum Format : uint8_t { + V0_HISTORICAL = 0, //!< historic format, before commit e6b343d88 + V1_DETERMINISTIC = 1, //!< for pre-asmap files + V2_ASMAP = 2, //!< for files including asmap version + V3_BIP155 = 3, //!< same as V2_ASMAP plus addresses are in BIP155 format + }; + + //! The maximum format this software knows it can unserialize. Also, we always serialize + //! in this format. + //! The format (first byte in the serialized stream) can be higher than this and + //! still this software may be able to unserialize the file - if the second byte + //! (see `lowest_compatible` in `Unserialize()`) is less or equal to this. + static constexpr Format FILE_FORMAT = Format::V3_BIP155; + + //! The initial value of a field that is incremented every time an incompatible format + //! change is made (such that old software versions would not be able to parse and + //! understand the new file format). This is 32 because we overtook the "key size" + //! field which was 32 historically. + //! @note Don't increment this. Increment `lowest_compatible` in `Serialize()` instead. + static constexpr uint8_t INCOMPATIBILITY_BASE = 32; + + //! last used nId + int nIdCount GUARDED_BY(cs){0}; + + //! table with information about all nIds + std::unordered_map<int, AddrInfo> mapInfo GUARDED_BY(cs); + + //! find an nId based on its network address + std::unordered_map<CNetAddr, int, CNetAddrHash> mapAddr GUARDED_BY(cs); + + //! randomly-ordered vector of all nIds + //! This is mutable because it is unobservable outside the class, so any + //! changes to it (even in const methods) are also unobservable. + mutable std::vector<int> vRandom GUARDED_BY(cs); + + // number of "tried" entries + int nTried GUARDED_BY(cs){0}; + + //! list of "tried" buckets + int vvTried[ADDRMAN_TRIED_BUCKET_COUNT][ADDRMAN_BUCKET_SIZE] GUARDED_BY(cs); + + //! number of (unique) "new" entries + int nNew GUARDED_BY(cs){0}; + + //! list of "new" buckets + int vvNew[ADDRMAN_NEW_BUCKET_COUNT][ADDRMAN_BUCKET_SIZE] GUARDED_BY(cs); + + //! last time Good was called (memory only). Initially set to 1 so that "never" is strictly worse. + int64_t nLastGood GUARDED_BY(cs){1}; + + //! Holds addrs inserted into tried table that collide with existing entries. Test-before-evict discipline used to resolve these collisions. + std::set<int> m_tried_collisions; + + /** Perform consistency checks every m_consistency_check_ratio operations (if non-zero). */ + 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; + + //! Find an entry. + AddrInfo* Find(const CNetAddr& addr, int* pnId = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs); + + //! Create a new entry and add it to the internal data structures mapInfo, mapAddr and vRandom. + AddrInfo* Create(const CAddress& addr, const CNetAddr& addrSource, int* pnId = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs); + + //! Swap two elements in vRandom. + void SwapRandom(unsigned int nRandomPos1, unsigned int nRandomPos2) const EXCLUSIVE_LOCKS_REQUIRED(cs); + + //! Delete an entry. It must not be in tried, and have refcount 0. + void Delete(int nId) EXCLUSIVE_LOCKS_REQUIRED(cs); + + //! Clear a position in a "new" table. This is the only place where entries are actually deleted. + void ClearNew(int nUBucket, int nUBucketPos) EXCLUSIVE_LOCKS_REQUIRED(cs); + + //! Move an entry from the "new" table(s) to the "tried" table + void MakeTried(AddrInfo& info, int nId) EXCLUSIVE_LOCKS_REQUIRED(cs); + + void Good_(const CService& addr, bool test_before_evict, int64_t time) EXCLUSIVE_LOCKS_REQUIRED(cs); + + bool Add_(const CAddress& addr, const CNetAddr& source, int64_t nTimePenalty) EXCLUSIVE_LOCKS_REQUIRED(cs); + + void Attempt_(const CService& addr, bool fCountFailure, int64_t nTime) EXCLUSIVE_LOCKS_REQUIRED(cs); + + std::pair<CAddress, int64_t> 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, int64_t nTime) EXCLUSIVE_LOCKS_REQUIRED(cs); + + void SetServices_(const CService& addr, ServiceFlags nServices) EXCLUSIVE_LOCKS_REQUIRED(cs); + + void ResolveCollisions_() EXCLUSIVE_LOCKS_REQUIRED(cs); + + std::pair<CAddress, int64_t> SelectTriedCollision_() EXCLUSIVE_LOCKS_REQUIRED(cs); + + //! Consistency check, taking into account m_consistency_check_ratio. Will std::abort if an inconsistency is detected. + void Check() const EXCLUSIVE_LOCKS_REQUIRED(cs); + + //! Perform consistency check, regardless of m_consistency_check_ratio. + //! @returns an error code or zero. + int ForceCheckAddrman() const EXCLUSIVE_LOCKS_REQUIRED(cs); +}; + +#endif // BITCOIN_ADDRMAN_IMPL_H |