1 // Copyright (c) 2021-present The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 5 #ifndef BITCOIN_ADDRMAN_IMPL_H
6 #define BITCOIN_ADDRMAN_IMPL_H
7 8 #include <logging/timer.h>
9 #include <netaddress.h>
10 #include <protocol.h>
11 #include <serialize.h>
12 #include <sync.h>
13 #include <uint256.h>
14 #include <util/log.h>
15 #include <util/time.h>
16 17 #include <cstdint>
18 #include <optional>
19 #include <set>
20 #include <unordered_map>
21 #include <unordered_set>
22 #include <utility>
23 #include <vector>
24 25 /** Total number of buckets for tried addresses */
26 static constexpr int32_t ADDRMAN_TRIED_BUCKET_COUNT_LOG2{8};
27 static constexpr int ADDRMAN_TRIED_BUCKET_COUNT{1 << ADDRMAN_TRIED_BUCKET_COUNT_LOG2};
28 /** Total number of buckets for new addresses */
29 static constexpr int32_t ADDRMAN_NEW_BUCKET_COUNT_LOG2{10};
30 static constexpr int ADDRMAN_NEW_BUCKET_COUNT{1 << ADDRMAN_NEW_BUCKET_COUNT_LOG2};
31 /** Maximum allowed number of entries in buckets for new and tried addresses */
32 static constexpr int32_t ADDRMAN_BUCKET_SIZE_LOG2{6};
33 static constexpr int ADDRMAN_BUCKET_SIZE{1 << ADDRMAN_BUCKET_SIZE_LOG2};
34 35 /**
36 * User-defined type for the internally used nIds
37 * This used to be int, making it feasible for attackers to cause an overflow,
38 * see https://bitcoincore.org/en/2024/07/31/disclose-addrman-int-overflow/
39 */
40 using nid_type = int64_t;
41 42 /**
43 * Extended statistics about a CAddress
44 */
45 class AddrInfo : public CAddress
46 {
47 public:
48 //! last try whatsoever by us (memory only)
49 NodeSeconds m_last_try{0s};
50 51 //! last counted attempt (memory only)
52 NodeSeconds m_last_count_attempt{0s};
53 54 //! where knowledge about this address first came from
55 CNetAddr source;
56 57 //! last successful connection by us
58 NodeSeconds m_last_success{0s};
59 60 //! connection attempts since last successful attempt
61 int nAttempts{0};
62 63 //! reference count in new sets (memory only)
64 int nRefCount{0};
65 66 //! in tried set? (memory only)
67 bool fInTried{false};
68 69 //! position in vRandom
70 mutable int nRandomPos{-1};
71 72 SERIALIZE_METHODS(AddrInfo, obj)
73 {
74 READWRITE(AsBase<CAddress>(obj), obj.source, Using<ChronoFormatter<int64_t>>(obj.m_last_success), obj.nAttempts);
75 }
76 77 AddrInfo(const CAddress &addrIn, const CNetAddr &addrSource) : CAddress(addrIn), source(addrSource)
78 {
79 }
80 81 AddrInfo() : CAddress(), source()
82 {
83 }
84 85 //! Calculate in which "tried" bucket this entry belongs
86 int GetTriedBucket(const uint256& nKey, const NetGroupManager& netgroupman) const;
87 88 //! Calculate in which "new" bucket this entry belongs, given a certain source
89 int GetNewBucket(const uint256& nKey, const CNetAddr& src, const NetGroupManager& netgroupman) const;
90 91 //! Calculate in which "new" bucket this entry belongs, using its default source
92 int GetNewBucket(const uint256& nKey, const NetGroupManager& netgroupman) const
93 {
94 return GetNewBucket(nKey, source, netgroupman);
95 }
96 97 //! Calculate in which position of a bucket to store this entry.
98 int GetBucketPosition(const uint256 &nKey, bool fNew, int bucket) const;
99 100 //! Determine whether the statistics about this entry are bad enough so that it can just be deleted
101 bool IsTerrible(NodeSeconds now = Now<NodeSeconds>()) const;
102 103 //! Calculate the relative chance this entry should be given when selecting nodes to connect to
104 double GetChance(NodeSeconds now = Now<NodeSeconds>()) const;
105 };
106 107 class AddrManImpl
108 {
109 public:
110 AddrManImpl(const NetGroupManager& netgroupman, bool deterministic, int32_t consistency_check_ratio);
111 112 ~AddrManImpl();
113 114 template <typename Stream>
115 void Serialize(Stream& s_) const EXCLUSIVE_LOCKS_REQUIRED(!cs);
116 117 template <typename Stream>
118 void Unserialize(Stream& s_) EXCLUSIVE_LOCKS_REQUIRED(!cs);
119 120 size_t Size(std::optional<Network> net, std::optional<bool> in_new) const EXCLUSIVE_LOCKS_REQUIRED(!cs);
121 122 bool Add(const std::vector<CAddress>& vAddr, const CNetAddr& source, std::chrono::seconds time_penalty)
123 EXCLUSIVE_LOCKS_REQUIRED(!cs);
124 125 bool Good(const CService& addr, NodeSeconds time)
126 EXCLUSIVE_LOCKS_REQUIRED(!cs);
127 128 void Attempt(const CService& addr, bool fCountFailure, NodeSeconds time)
129 EXCLUSIVE_LOCKS_REQUIRED(!cs);
130 131 void ResolveCollisions() EXCLUSIVE_LOCKS_REQUIRED(!cs);
132 133 std::pair<CAddress, NodeSeconds> SelectTriedCollision() EXCLUSIVE_LOCKS_REQUIRED(!cs);
134 135 std::pair<CAddress, NodeSeconds> Select(bool new_only, const std::unordered_set<Network>& networks) const
136 EXCLUSIVE_LOCKS_REQUIRED(!cs);
137 138 std::vector<CAddress> GetAddr(size_t max_addresses, size_t max_pct, std::optional<Network> network, bool filtered = true) const
139 EXCLUSIVE_LOCKS_REQUIRED(!cs);
140 141 std::vector<std::pair<AddrInfo, AddressPosition>> GetEntries(bool from_tried) const
142 EXCLUSIVE_LOCKS_REQUIRED(!cs);
143 144 void Connected(const CService& addr, NodeSeconds time)
145 EXCLUSIVE_LOCKS_REQUIRED(!cs);
146 147 void SetServices(const CService& addr, ServiceFlags nServices)
148 EXCLUSIVE_LOCKS_REQUIRED(!cs);
149 150 std::optional<AddressPosition> FindAddressEntry(const CAddress& addr)
151 EXCLUSIVE_LOCKS_REQUIRED(!cs);
152 153 friend class AddrManDeterministic;
154 155 private:
156 //! A mutex to protect the inner data structures.
157 mutable Mutex cs;
158 159 //! Source of random numbers for randomization in inner loops
160 mutable FastRandomContext insecure_rand GUARDED_BY(cs);
161 162 //! secret key to randomize bucket select with
163 uint256 nKey;
164 165 //! Serialization versions.
166 enum Format : uint8_t {
167 V0_HISTORICAL = 0, //!< historic format, before commit e6b343d88
168 V1_DETERMINISTIC = 1, //!< for pre-asmap files
169 V2_ASMAP = 2, //!< for files including asmap version
170 V3_BIP155 = 3, //!< same as V2_ASMAP plus addresses are in BIP155 format
171 V4_MULTIPORT = 4, //!< adds support for multiple ports per IP
172 };
173 174 //! The maximum format this software knows it can unserialize. Also, we always serialize
175 //! in this format.
176 //! The format (first byte in the serialized stream) can be higher than this and
177 //! still this software may be able to unserialize the file - if the second byte
178 //! (see `lowest_compatible` in `Unserialize()`) is less or equal to this.
179 static constexpr Format FILE_FORMAT = Format::V4_MULTIPORT;
180 181 //! The initial value of a field that is incremented every time an incompatible format
182 //! change is made (such that old software versions would not be able to parse and
183 //! understand the new file format). This is 32 because we overtook the "key size"
184 //! field which was 32 historically.
185 //! @note Don't increment this. Increment `lowest_compatible` in `Serialize()` instead.
186 static constexpr uint8_t INCOMPATIBILITY_BASE = 32;
187 188 //! last used nId
189 nid_type nIdCount GUARDED_BY(cs){0};
190 191 //! table with information about all nIds
192 std::unordered_map<nid_type, AddrInfo> mapInfo GUARDED_BY(cs);
193 194 //! find an nId based on its network address and port.
195 std::unordered_map<CService, nid_type, CServiceHash> mapAddr GUARDED_BY(cs);
196 197 //! randomly-ordered vector of all nIds
198 //! This is mutable because it is unobservable outside the class, so any
199 //! changes to it (even in const methods) are also unobservable.
200 mutable std::vector<nid_type> vRandom GUARDED_BY(cs);
201 202 // number of "tried" entries
203 int nTried GUARDED_BY(cs){0};
204 205 //! list of "tried" buckets
206 nid_type vvTried[ADDRMAN_TRIED_BUCKET_COUNT][ADDRMAN_BUCKET_SIZE] GUARDED_BY(cs);
207 208 //! number of (unique) "new" entries
209 int nNew GUARDED_BY(cs){0};
210 211 //! list of "new" buckets
212 nid_type vvNew[ADDRMAN_NEW_BUCKET_COUNT][ADDRMAN_BUCKET_SIZE] GUARDED_BY(cs);
213 214 //! last time Good was called (memory only). Initially set to 1 so that "never" is strictly worse.
215 NodeSeconds m_last_good GUARDED_BY(cs){1s};
216 217 //! Holds addrs inserted into tried table that collide with existing entries. Test-before-evict discipline used to resolve these collisions.
218 std::set<nid_type> m_tried_collisions;
219 220 /** Perform consistency checks every m_consistency_check_ratio operations (if non-zero). */
221 const int32_t m_consistency_check_ratio;
222 223 /** Reference to the netgroup manager. netgroupman must be constructed before addrman and destructed after. */
224 const NetGroupManager& m_netgroupman;
225 226 struct NewTriedCount {
227 size_t n_new;
228 size_t n_tried;
229 };
230 231 /** Number of entries in addrman per network and new/tried table. */
232 std::unordered_map<Network, NewTriedCount> m_network_counts GUARDED_BY(cs);
233 234 //! Find an entry.
235 AddrInfo* Find(const CService& addr, nid_type* pnId = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs);
236 237 //! Create a new entry and add it to the internal data structures mapInfo, mapAddr and vRandom.
238 AddrInfo* Create(const CAddress& addr, const CNetAddr& addrSource, nid_type* pnId = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs);
239 240 //! Swap two elements in vRandom.
241 void SwapRandom(unsigned int nRandomPos1, unsigned int nRandomPos2) const EXCLUSIVE_LOCKS_REQUIRED(cs);
242 243 //! Delete an entry. It must not be in tried, and have refcount 0.
244 void Delete(nid_type nId) EXCLUSIVE_LOCKS_REQUIRED(cs);
245 246 //! Clear a position in a "new" table. This is the only place where entries are actually deleted.
247 void ClearNew(int nUBucket, int nUBucketPos) EXCLUSIVE_LOCKS_REQUIRED(cs);
248 249 //! Move an entry from the "new" table(s) to the "tried" table
250 void MakeTried(AddrInfo& info, nid_type nId) EXCLUSIVE_LOCKS_REQUIRED(cs);
251 252 /** Attempt to add a single address to addrman's new table.
253 * @see AddrMan::Add() for parameters. */
254 bool AddSingle(const CAddress& addr, const CNetAddr& source, std::chrono::seconds time_penalty) EXCLUSIVE_LOCKS_REQUIRED(cs);
255 256 bool Good_(const CService& addr, bool test_before_evict, NodeSeconds time) EXCLUSIVE_LOCKS_REQUIRED(cs);
257 258 bool Add_(const std::vector<CAddress>& vAddr, const CNetAddr& source, std::chrono::seconds time_penalty) EXCLUSIVE_LOCKS_REQUIRED(cs);
259 260 void Attempt_(const CService& addr, bool fCountFailure, NodeSeconds time) EXCLUSIVE_LOCKS_REQUIRED(cs);
261 262 std::pair<CAddress, NodeSeconds> Select_(bool new_only, const std::unordered_set<Network>& networks) const EXCLUSIVE_LOCKS_REQUIRED(cs);
263 264 /** Helper to generalize looking up an addrman entry from either table.
265 *
266 * @return nid_type The nid of the entry. If the addrman position is empty or not found, returns -1.
267 * */
268 nid_type GetEntry(bool use_tried, size_t bucket, size_t position) const EXCLUSIVE_LOCKS_REQUIRED(cs);
269 270 std::vector<CAddress> GetAddr_(size_t max_addresses, size_t max_pct, std::optional<Network> network, bool filtered = true) const EXCLUSIVE_LOCKS_REQUIRED(cs);
271 272 std::vector<std::pair<AddrInfo, AddressPosition>> GetEntries_(bool from_tried) const EXCLUSIVE_LOCKS_REQUIRED(cs);
273 274 void Connected_(const CService& addr, NodeSeconds time) EXCLUSIVE_LOCKS_REQUIRED(cs);
275 276 void SetServices_(const CService& addr, ServiceFlags nServices) EXCLUSIVE_LOCKS_REQUIRED(cs);
277 278 void ResolveCollisions_() EXCLUSIVE_LOCKS_REQUIRED(cs);
279 280 std::pair<CAddress, NodeSeconds> SelectTriedCollision_() EXCLUSIVE_LOCKS_REQUIRED(cs);
281 282 std::optional<AddressPosition> FindAddressEntry_(const CAddress& addr) EXCLUSIVE_LOCKS_REQUIRED(cs);
283 284 size_t Size_(std::optional<Network> net, std::optional<bool> in_new) const EXCLUSIVE_LOCKS_REQUIRED(cs);
285 286 //! Consistency check, taking into account m_consistency_check_ratio.
287 //! Will std::abort if an inconsistency is detected.
288 void Check() const EXCLUSIVE_LOCKS_REQUIRED(cs);
289 290 //! Perform consistency check, regardless of m_consistency_check_ratio.
291 //! @returns an error code or zero.
292 int CheckAddrman() const EXCLUSIVE_LOCKS_REQUIRED(cs);
293 };
294 295 #endif // BITCOIN_ADDRMAN_IMPL_H
296