diff options
Diffstat (limited to 'src/addrman.h')
| -rw-r--r-- | src/addrman.h | 94 |
1 files changed, 66 insertions, 28 deletions
diff --git a/src/addrman.h b/src/addrman.h index b4089dc894..9ac67b7af6 100644 --- a/src/addrman.h +++ b/src/addrman.h @@ -7,6 +7,7 @@ #define BITCOIN_ADDRMAN_H #include <clientversion.h> +#include <config/bitcoin-config.h> #include <netaddress.h> #include <protocol.h> #include <random.h> @@ -176,6 +177,28 @@ protected: mutable RecursiveMutex cs; private: + //! 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); @@ -258,21 +281,23 @@ protected: //! Select several addresses at once. void GetAddr_(std::vector<CAddress> &vAddr, size_t max_addresses, size_t max_pct) EXCLUSIVE_LOCKS_REQUIRED(cs); - //! Mark an entry as currently-connected-to. - void Connected_(const CService &addr, int64_t nTime) EXCLUSIVE_LOCKS_REQUIRED(cs); + /** We have successfully connected to this peer. Calling this function + * updates the CAddress's nTime, which is used in our IsTerrible() + * decisions and gossiped to peers. Callers should be careful that updating + * this information doesn't leak topology information to network spies. + * + * net_processing calls this function when it *disconnects* from a peer to + * not leak information about currently connected peers. + * + * @param[in] addr The address of the peer we were connected to + * @param[in] nTime The time that we were last connected to this peer + */ + void Connected_(const CService& addr, int64_t nTime) EXCLUSIVE_LOCKS_REQUIRED(cs); //! Update an entry's service bits. void SetServices_(const CService &addr, ServiceFlags nServices) EXCLUSIVE_LOCKS_REQUIRED(cs); public: - //! Serialization versions. - enum class 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 - }; - // 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. @@ -295,8 +320,18 @@ public: /** * Serialized format. - * * version byte (@see `Format`) - * * 0x20 + nKey (serialized as if it were a vector, for backward compatibility) + * * format version byte (@see `Format`) + * * lowest compatible format version byte. This is used to help old software decide + * whether to parse the file. For example: + * * Bitcoin Core version N knows how to parse up to format=3. If a new format=4 is + * introduced in version N+1 that is compatible with format=3 and it is known that + * version N will be able to parse it, then version N+1 will write + * (format=4, lowest_compatible=3) in the first two bytes of the file, and so + * version N will still try to parse it. + * * Bitcoin Core version N+2 introduces a new incompatible format=5. It will write + * (format=5, lowest_compatible=5) and so any versions that do not know how to parse + * format=5 will not try to read the file. + * * nKey * * nNew * * nTried * * number of "new" buckets XOR 2**30 @@ -327,12 +362,17 @@ public: { LOCK(cs); - // Always serialize in the latest version (currently Format::V3_BIP155). + // Always serialize in the latest version (FILE_FORMAT). OverrideStream<Stream> s(&s_, s_.GetType(), s_.GetVersion() | ADDRV2_FORMAT); - s << static_cast<uint8_t>(Format::V3_BIP155); - s << ((unsigned char)32); + s << static_cast<uint8_t>(FILE_FORMAT); + + // Increment `lowest_compatible` iff a newly introduced format is incompatible with + // the previous one. + static constexpr uint8_t lowest_compatible = Format::V3_BIP155; + s << static_cast<uint8_t>(INCOMPATIBILITY_BASE + lowest_compatible); + s << nKey; s << nNew; s << nTried; @@ -392,15 +432,6 @@ public: Format format; s_ >> Using<CustomUintFormatter<1>>(format); - static constexpr Format maximum_supported_format = Format::V3_BIP155; - if (format > maximum_supported_format) { - throw std::ios_base::failure(strprintf( - "Unsupported format of addrman database: %u. Maximum supported is %u. " - "Continuing operation without using the saved list of peers.", - static_cast<uint8_t>(format), - static_cast<uint8_t>(maximum_supported_format))); - } - int stream_version = s_.GetVersion(); if (format >= Format::V3_BIP155) { // Add ADDRV2_FORMAT to the version so that the CNetAddr and CAddress @@ -410,9 +441,16 @@ public: OverrideStream<Stream> s(&s_, s_.GetType(), stream_version); - unsigned char nKeySize; - s >> nKeySize; - if (nKeySize != 32) throw std::ios_base::failure("Incorrect keysize in addrman deserialization"); + uint8_t compat; + s >> compat; + const uint8_t lowest_compatible = compat - INCOMPATIBILITY_BASE; + if (lowest_compatible > FILE_FORMAT) { + throw std::ios_base::failure(strprintf( + "Unsupported format of addrman database: %u. It is compatible with formats >=%u, " + "but the maximum supported by this version of %s is %u.", + format, lowest_compatible, PACKAGE_NAME, static_cast<uint8_t>(FILE_FORMAT))); + } + s >> nKey; s >> nNew; s >> nTried; @@ -676,7 +714,7 @@ public: return vAddr; } - //! Mark an entry as currently-connected-to. + //! Outer function for Connected_() void Connected(const CService &addr, int64_t nTime = GetAdjustedTime()) { LOCK(cs); |