diff options
Diffstat (limited to 'src/netaddress.h')
| -rw-r--r-- | src/netaddress.h | 357 |
1 files changed, 331 insertions, 26 deletions
diff --git a/src/netaddress.h b/src/netaddress.h index 0365907d44..f35b01d202 100644 --- a/src/netaddress.h +++ b/src/netaddress.h @@ -9,14 +9,29 @@ #include <config/bitcoin-config.h> #endif +#include <attributes.h> #include <compat.h> +#include <prevector.h> #include <serialize.h> +#include <tinyformat.h> +#include <util/strencodings.h> +#include <util/string.h> +#include <array> #include <cstdint> +#include <ios> #include <string> #include <vector> /** + * A flag that is ORed into the protocol version to designate that addresses + * should be serialized in (unserialized from) v2 format (BIP155). + * Make sure that this does not collide with any of the values in `version.h` + * or with `SERIALIZE_TRANSACTION_NO_WITNESS`. + */ +static const int ADDRV2_FORMAT = 0x20000000; + +/** * A network type. * @note An address may belong to more than one network, for example `10.0.0.1` * belongs to both `NET_UNROUTABLE` and `NET_IPV4`. @@ -36,19 +51,68 @@ enum Network /// IPv6 NET_IPV6, - /// TORv2 + /// TOR (v2 or v3) NET_ONION, - /// A set of dummy addresses that map a name to an IPv6 address. These - /// addresses belong to RFC4193's fc00::/7 subnet (unique-local addresses). - /// We use them to map a string or FQDN to an IPv6 address in CAddrMan to - /// keep track of which DNS seeds were used. + /// I2P + NET_I2P, + + /// CJDNS + NET_CJDNS, + + /// A set of addresses that represent the hash of a string or FQDN. We use + /// them in CAddrMan to keep track of which DNS seeds were used. NET_INTERNAL, /// Dummy value to indicate the number of NET_* constants. NET_MAX, }; +/// Prefix of an IPv6 address when it contains an embedded IPv4 address. +/// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155). +static const std::array<uint8_t, 12> IPV4_IN_IPV6_PREFIX{ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF +}; + +/// Prefix of an IPv6 address when it contains an embedded TORv2 address. +/// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155). +/// Such dummy IPv6 addresses are guaranteed to not be publicly routable as they +/// fall under RFC4193's fc00::/7 subnet allocated to unique-local addresses. +static const std::array<uint8_t, 6> TORV2_IN_IPV6_PREFIX{ + 0xFD, 0x87, 0xD8, 0x7E, 0xEB, 0x43 +}; + +/// Prefix of an IPv6 address when it contains an embedded "internal" address. +/// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155). +/// The prefix comes from 0xFD + SHA256("bitcoin")[0:5]. +/// Such dummy IPv6 addresses are guaranteed to not be publicly routable as they +/// fall under RFC4193's fc00::/7 subnet allocated to unique-local addresses. +static const std::array<uint8_t, 6> INTERNAL_IN_IPV6_PREFIX{ + 0xFD, 0x6B, 0x88, 0xC0, 0x87, 0x24 // 0xFD + sha256("bitcoin")[0:5]. +}; + +/// Size of IPv4 address (in bytes). +static constexpr size_t ADDR_IPV4_SIZE = 4; + +/// Size of IPv6 address (in bytes). +static constexpr size_t ADDR_IPV6_SIZE = 16; + +/// Size of TORv2 address (in bytes). +static constexpr size_t ADDR_TORV2_SIZE = 10; + +/// Size of TORv3 address (in bytes). This is the length of just the address +/// as used in BIP155, without the checksum and the version byte. +static constexpr size_t ADDR_TORV3_SIZE = 32; + +/// Size of I2P address (in bytes). +static constexpr size_t ADDR_I2P_SIZE = 32; + +/// Size of CJDNS address (in bytes). +static constexpr size_t ADDR_CJDNS_SIZE = 16; + +/// Size of "internal" (NET_INTERNAL) address (in bytes). +static constexpr size_t ADDR_INTERNAL_SIZE = 10; + /** * Network address. */ @@ -56,12 +120,21 @@ class CNetAddr { protected: /** + * Raw representation of the network address. + * In network byte order (big endian) for IPv4 and IPv6. + */ + prevector<ADDR_IPV6_SIZE, uint8_t> m_addr{ADDR_IPV6_SIZE, 0x0}; + + /** * Network to which this address belongs. */ Network m_net{NET_IPV6}; - unsigned char ip[16]; // in network byte order - uint32_t scopeId{0}; // for scoped/link-local ipv6 addresses + /** + * Scope id if scoped/link-local IPV6 address. + * See https://tools.ietf.org/html/rfc4007 + */ + uint32_t m_scope_id{0}; public: CNetAddr(); @@ -74,13 +147,7 @@ class CNetAddr * (e.g. IPv4) disguised as IPv6. This encoding is used in the legacy * `addr` encoding. */ - void SetLegacyIPv6(const uint8_t ipv6[16]); - - /** - * Set raw IPv4 or IPv6 address (in network byte order) - * @note Only NET_IPV4 and NET_IPV6 are allowed for network. - */ - void SetRaw(Network network, const uint8_t *data); + void SetLegacyIPv6(Span<const uint8_t> ipv6); bool SetInternal(const std::string& name); @@ -104,17 +171,24 @@ class CNetAddr bool IsRFC6145() const; // IPv6 IPv4-translated address (::FFFF:0:0:0/96) (actually defined in RFC2765) bool IsHeNet() const; // IPv6 Hurricane Electric - https://he.net (2001:0470::/36) bool IsTor() const; + bool IsI2P() const; + bool IsCJDNS() const; bool IsLocal() const; bool IsRoutable() const; bool IsInternal() const; bool IsValid() const; + + /** + * Check if the current object can be serialized in pre-ADDRv2/BIP155 format. + */ + bool IsAddrV1Compatible() const; + enum Network GetNetwork() const; std::string ToString() const; std::string ToStringIP() const; - unsigned int GetByte(int n) const; uint64_t GetHash() const; bool GetInAddr(struct in_addr* pipv4Addr) const; - uint32_t GetNetClass() const; + Network GetNetClass() const; //! For IPv4, mapped IPv4, SIIT translated IPv4, Teredo, 6to4 tunneled addresses, return the relevant IPv4 address as a uint32. uint32_t GetLinkedIPv4() const; @@ -127,7 +201,7 @@ class CNetAddr uint32_t GetMappedAS(const std::vector<bool> &asmap) const; std::vector<unsigned char> GetGroup(const std::vector<bool> &asmap) const; - std::vector<unsigned char> GetAddrBytes() const { return {std::begin(ip), std::end(ip)}; } + std::vector<unsigned char> GetAddrBytes() const; int GetReachabilityFrom(const CNetAddr *paddrPartner = nullptr) const; explicit CNetAddr(const struct in6_addr& pipv6Addr, const uint32_t scope = 0); @@ -138,12 +212,24 @@ class CNetAddr friend bool operator<(const CNetAddr& a, const CNetAddr& b); /** + * Whether this address should be relayed to other peers even if we can't reach it ourselves. + */ + bool IsRelayable() const + { + return IsIPv4() || IsIPv6() || IsTor(); + } + + /** * Serialize to a stream. */ template <typename Stream> void Serialize(Stream& s) const { - s << ip; + if (s.GetVersion() & ADDRV2_FORMAT) { + SerializeV2Stream(s); + } else { + SerializeV1Stream(s); + } } /** @@ -152,14 +238,215 @@ class CNetAddr template <typename Stream> void Unserialize(Stream& s) { - unsigned char ip_temp[sizeof(ip)]; - s >> ip_temp; + if (s.GetVersion() & ADDRV2_FORMAT) { + UnserializeV2Stream(s); + } else { + UnserializeV1Stream(s); + } + } + + friend class CSubNet; + + private: + /** + * BIP155 network ids recognized by this software. + */ + enum BIP155Network : uint8_t { + IPV4 = 1, + IPV6 = 2, + TORV2 = 3, + TORV3 = 4, + I2P = 5, + CJDNS = 6, + }; + + /** + * Size of CNetAddr when serialized as ADDRv1 (pre-BIP155) (in bytes). + */ + static constexpr size_t V1_SERIALIZATION_SIZE = ADDR_IPV6_SIZE; + + /** + * Maximum size of an address as defined in BIP155 (in bytes). + * This is only the size of the address, not the entire CNetAddr object + * when serialized. + */ + static constexpr size_t MAX_ADDRV2_SIZE = 512; + + /** + * Get the BIP155 network id of this address. + * Must not be called for IsInternal() objects. + * @returns BIP155 network id + */ + BIP155Network GetBIP155Network() const; + + /** + * Set `m_net` from the provided BIP155 network id and size after validation. + * @retval true the network was recognized, is valid and `m_net` was set + * @retval false not recognised (from future?) and should be silently ignored + * @throws std::ios_base::failure if the network is one of the BIP155 founding + * networks (id 1..6) with wrong address size. + */ + bool SetNetFromBIP155Network(uint8_t possible_bip155_net, size_t address_size); + + /** + * Serialize in pre-ADDRv2/BIP155 format to an array. + */ + void SerializeV1Array(uint8_t (&arr)[V1_SERIALIZATION_SIZE]) const + { + size_t prefix_size; + + switch (m_net) { + case NET_IPV6: + assert(m_addr.size() == sizeof(arr)); + memcpy(arr, m_addr.data(), m_addr.size()); + return; + case NET_IPV4: + prefix_size = sizeof(IPV4_IN_IPV6_PREFIX); + assert(prefix_size + m_addr.size() == sizeof(arr)); + memcpy(arr, IPV4_IN_IPV6_PREFIX.data(), prefix_size); + memcpy(arr + prefix_size, m_addr.data(), m_addr.size()); + return; + case NET_ONION: + if (m_addr.size() == ADDR_TORV3_SIZE) { + break; + } + prefix_size = sizeof(TORV2_IN_IPV6_PREFIX); + assert(prefix_size + m_addr.size() == sizeof(arr)); + memcpy(arr, TORV2_IN_IPV6_PREFIX.data(), prefix_size); + memcpy(arr + prefix_size, m_addr.data(), m_addr.size()); + return; + case NET_INTERNAL: + prefix_size = sizeof(INTERNAL_IN_IPV6_PREFIX); + assert(prefix_size + m_addr.size() == sizeof(arr)); + memcpy(arr, INTERNAL_IN_IPV6_PREFIX.data(), prefix_size); + memcpy(arr + prefix_size, m_addr.data(), m_addr.size()); + return; + case NET_I2P: + break; + case NET_CJDNS: + break; + case NET_UNROUTABLE: + case NET_MAX: + assert(false); + } // no default case, so the compiler can warn about missing cases + + // Serialize TORv3, I2P and CJDNS as all-zeros. + memset(arr, 0x0, V1_SERIALIZATION_SIZE); + } + + /** + * Serialize in pre-ADDRv2/BIP155 format to a stream. + */ + template <typename Stream> + void SerializeV1Stream(Stream& s) const + { + uint8_t serialized[V1_SERIALIZATION_SIZE]; + + SerializeV1Array(serialized); + + s << serialized; + } + + /** + * Serialize as ADDRv2 / BIP155. + */ + template <typename Stream> + void SerializeV2Stream(Stream& s) const + { + if (IsInternal()) { + // Serialize NET_INTERNAL as embedded in IPv6. We need to + // serialize such addresses from addrman. + s << static_cast<uint8_t>(BIP155Network::IPV6); + s << COMPACTSIZE(ADDR_IPV6_SIZE); + SerializeV1Stream(s); + return; + } + + s << static_cast<uint8_t>(GetBIP155Network()); + s << m_addr; + } + + /** + * Unserialize from a pre-ADDRv2/BIP155 format from an array. + */ + void UnserializeV1Array(uint8_t (&arr)[V1_SERIALIZATION_SIZE]) + { // Use SetLegacyIPv6() so that m_net is set correctly. For example // ::FFFF:0102:0304 should be set as m_net=NET_IPV4 (1.2.3.4). - SetLegacyIPv6(ip_temp); + SetLegacyIPv6(arr); } - friend class CSubNet; + /** + * Unserialize from a pre-ADDRv2/BIP155 format from a stream. + */ + template <typename Stream> + void UnserializeV1Stream(Stream& s) + { + uint8_t serialized[V1_SERIALIZATION_SIZE]; + + s >> serialized; + + UnserializeV1Array(serialized); + } + + /** + * Unserialize from a ADDRv2 / BIP155 format. + */ + template <typename Stream> + void UnserializeV2Stream(Stream& s) + { + uint8_t bip155_net; + s >> bip155_net; + + size_t address_size; + s >> COMPACTSIZE(address_size); + + if (address_size > MAX_ADDRV2_SIZE) { + throw std::ios_base::failure(strprintf( + "Address too long: %u > %u", address_size, MAX_ADDRV2_SIZE)); + } + + m_scope_id = 0; + + if (SetNetFromBIP155Network(bip155_net, address_size)) { + m_addr.resize(address_size); + s >> MakeSpan(m_addr); + + if (m_net != NET_IPV6) { + return; + } + + // Do some special checks on IPv6 addresses. + + // Recognize NET_INTERNAL embedded in IPv6, such addresses are not + // gossiped but could be coming from addrman, when unserializing from + // disk. + if (HasPrefix(m_addr, INTERNAL_IN_IPV6_PREFIX)) { + m_net = NET_INTERNAL; + memmove(m_addr.data(), m_addr.data() + INTERNAL_IN_IPV6_PREFIX.size(), + ADDR_INTERNAL_SIZE); + m_addr.resize(ADDR_INTERNAL_SIZE); + return; + } + + if (!HasPrefix(m_addr, IPV4_IN_IPV6_PREFIX) && + !HasPrefix(m_addr, TORV2_IN_IPV6_PREFIX)) { + return; + } + + // IPv4 and TORv2 are not supposed to be embedded in IPv6 (like in V1 + // encoding). Unserialize as !IsValid(), thus ignoring them. + } else { + // If we receive an unknown BIP155 network id (from the future?) then + // ignore the address - unserialize as !IsValid(). + s.ignore(address_size); + } + + // Mimic a default-constructed CNetAddr object which is !IsValid() and thus + // will not be gossiped, but continue reading next addresses from the stream. + m_net = NET_IPV6; + m_addr.assign(ADDR_IPV6_SIZE, 0x0); + } }; class CSubNet @@ -172,13 +459,15 @@ class CSubNet /// Is this value valid? (only used to signal parse errors) bool valid; + bool SanityCheck() const; + public: CSubNet(); - CSubNet(const CNetAddr &addr, int32_t mask); - CSubNet(const CNetAddr &addr, const CNetAddr &mask); + CSubNet(const CNetAddr& addr, uint8_t mask); + CSubNet(const CNetAddr& addr, const CNetAddr& mask); //constructor for single ip subnet (<ipv4>/32 or <ipv6>/128) - explicit CSubNet(const CNetAddr &addr); + explicit CSubNet(const CNetAddr& addr); bool Match(const CNetAddr &addr) const; @@ -189,7 +478,23 @@ class CSubNet friend bool operator!=(const CSubNet& a, const CSubNet& b) { return !(a == b); } friend bool operator<(const CSubNet& a, const CSubNet& b); - SERIALIZE_METHODS(CSubNet, obj) { READWRITE(obj.network, obj.netmask, obj.valid); } + SERIALIZE_METHODS(CSubNet, obj) + { + READWRITE(obj.network); + if (obj.network.IsIPv4()) { + // Before commit 102867c587f5f7954232fb8ed8e85cda78bb4d32, CSubNet used the last 4 bytes of netmask + // to store the relevant bytes for an IPv4 mask. For compatiblity reasons, keep doing so in + // serialized form. + unsigned char dummy[12] = {0}; + READWRITE(dummy); + READWRITE(MakeSpan(obj.netmask).first(4)); + } else { + READWRITE(obj.netmask); + } + READWRITE(obj.valid); + // Mark invalid if the result doesn't pass sanity checking. + SER_READ(obj, if (obj.valid) obj.valid = obj.SanityCheck()); + } }; /** A combination of a network address (CNetAddr) and a (TCP) port */ |