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litecoin/src/addrman_impl.h

283 lines
11 KiB

// 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 <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);
bool 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);
std::optional<AddressPosition> FindAddressEntry(const CAddress& addr)
EXCLUSIVE_LOCKS_REQUIRED(!cs);
const std::vector<bool>& GetAsmap() const;
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
V4_MULTIPORT = 4, //!< adds support for multiple ports per IP
};
//! 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::V4_MULTIPORT;
//! 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 and port.
std::unordered_map<CService, int, CServiceHash> 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 CService& 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);
/** Attempt to add a single address to addrman's new table.
* @see AddrMan::Add() for parameters. */
bool AddSingle(const CAddress& addr, const CNetAddr& source, int64_t nTimePenalty) EXCLUSIVE_LOCKS_REQUIRED(cs);
bool Good_(const CService& addr, bool test_before_evict, int64_t time) EXCLUSIVE_LOCKS_REQUIRED(cs);
bool Add_(const std::vector<CAddress> &vAddr, 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);
std::optional<AddressPosition> FindAddressEntry_(const CAddress& addr) 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 CheckAddrman() const EXCLUSIVE_LOCKS_REQUIRED(cs);
};
#endif // BITCOIN_ADDRMAN_IMPL_H