netaddress.h
1 // Copyright (c) 2009-2022 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_NETADDRESS_H 6 #define BITCOIN_NETADDRESS_H 7 8 #include <compat/compat.h> 9 #include <crypto/siphash.h> 10 #include <prevector.h> 11 #include <random.h> 12 #include <serialize.h> 13 #include <tinyformat.h> 14 #include <util/strencodings.h> 15 #include <util/string.h> 16 17 #include <array> 18 #include <cstdint> 19 #include <ios> 20 #include <string> 21 #include <vector> 22 23 /** 24 * A network type. 25 * @note An address may belong to more than one network, for example `10.0.0.1` 26 * belongs to both `NET_UNROUTABLE` and `NET_IPV4`. 27 * Keep these sequential starting from 0 and `NET_MAX` as the last entry. 28 * We have loops like `for (int i = 0; i < NET_MAX; ++i)` that expect to iterate 29 * over all enum values and also `GetExtNetwork()` "extends" this enum by 30 * introducing standalone constants starting from `NET_MAX`. 31 */ 32 enum Network { 33 /// Addresses from these networks are not publicly routable on the global Internet. 34 NET_UNROUTABLE = 0, 35 36 /// IPv4 37 NET_IPV4, 38 39 /// IPv6 40 NET_IPV6, 41 42 /// TOR (v2 or v3) 43 NET_ONION, 44 45 /// I2P 46 NET_I2P, 47 48 /// CJDNS 49 NET_CJDNS, 50 51 /// A set of addresses that represent the hash of a string or FQDN. We use 52 /// them in AddrMan to keep track of which DNS seeds were used. 53 NET_INTERNAL, 54 55 /// Dummy value to indicate the number of NET_* constants. 56 NET_MAX, 57 }; 58 59 /// Prefix of an IPv6 address when it contains an embedded IPv4 address. 60 /// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155). 61 static const std::array<uint8_t, 12> IPV4_IN_IPV6_PREFIX{ 62 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF}; 63 64 /// Prefix of an IPv6 address when it contains an embedded TORv2 address. 65 /// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155). 66 /// Such dummy IPv6 addresses are guaranteed to not be publicly routable as they 67 /// fall under RFC4193's fc00::/7 subnet allocated to unique-local addresses. 68 static const std::array<uint8_t, 6> TORV2_IN_IPV6_PREFIX{ 69 0xFD, 0x87, 0xD8, 0x7E, 0xEB, 0x43}; 70 71 /// Prefix of an IPv6 address when it contains an embedded "internal" address. 72 /// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155). 73 /// The prefix comes from 0xFD + SHA256("bitcoin")[0:5]. 74 /// Such dummy IPv6 addresses are guaranteed to not be publicly routable as they 75 /// fall under RFC4193's fc00::/7 subnet allocated to unique-local addresses. 76 static const std::array<uint8_t, 6> INTERNAL_IN_IPV6_PREFIX{ 77 0xFD, 0x6B, 0x88, 0xC0, 0x87, 0x24 // 0xFD + sha256("bitcoin")[0:5]. 78 }; 79 80 /// All CJDNS addresses start with 0xFC. See 81 /// https://github.com/cjdelisle/cjdns/blob/master/doc/Whitepaper.md#pulling-it-all-together 82 static constexpr uint8_t CJDNS_PREFIX{0xFC}; 83 84 /// Size of IPv4 address (in bytes). 85 static constexpr size_t ADDR_IPV4_SIZE = 4; 86 87 /// Size of IPv6 address (in bytes). 88 static constexpr size_t ADDR_IPV6_SIZE = 16; 89 90 /// Size of TORv3 address (in bytes). This is the length of just the address 91 /// as used in BIP155, without the checksum and the version byte. 92 static constexpr size_t ADDR_TORV3_SIZE = 32; 93 94 /// Size of I2P address (in bytes). 95 static constexpr size_t ADDR_I2P_SIZE = 32; 96 97 /// Size of CJDNS address (in bytes). 98 static constexpr size_t ADDR_CJDNS_SIZE = 16; 99 100 /// Size of "internal" (NET_INTERNAL) address (in bytes). 101 static constexpr size_t ADDR_INTERNAL_SIZE = 10; 102 103 /// SAM 3.1 and earlier do not support specifying ports and force the port to 0. 104 static constexpr uint16_t I2P_SAM31_PORT{0}; 105 106 std::string OnionToString(Span<const uint8_t> addr); 107 108 /** 109 * Network address. 110 */ 111 class CNetAddr 112 { 113 protected: 114 /** 115 * Raw representation of the network address. 116 * In network byte order (big endian) for IPv4 and IPv6. 117 */ 118 prevector<ADDR_IPV6_SIZE, uint8_t> m_addr{ADDR_IPV6_SIZE, 0x0}; 119 120 /** 121 * Network to which this address belongs. 122 */ 123 Network m_net{NET_IPV6}; 124 125 /** 126 * Scope id if scoped/link-local IPV6 address. 127 * See https://tools.ietf.org/html/rfc4007 128 */ 129 uint32_t m_scope_id{0}; 130 131 public: 132 CNetAddr(); 133 explicit CNetAddr(const struct in_addr& ipv4Addr); 134 void SetIP(const CNetAddr& ip); 135 136 /** 137 * Set from a legacy IPv6 address. 138 * Legacy IPv6 address may be a normal IPv6 address, or another address 139 * (e.g. IPv4) disguised as IPv6. This encoding is used in the legacy 140 * `addr` encoding. 141 */ 142 void SetLegacyIPv6(Span<const uint8_t> ipv6); 143 144 bool SetInternal(const std::string& name); 145 146 /** 147 * Parse a Tor or I2P address and set this object to it. 148 * @param[in] addr Address to parse, for example 149 * pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion or 150 * ukeu3k5oycgaauneqgtnvselmt4yemvoilkln7jpvamvfx7dnkdq.b32.i2p. 151 * @returns Whether the operation was successful. 152 * @see CNetAddr::IsTor(), CNetAddr::IsI2P() 153 */ 154 bool SetSpecial(const std::string& addr); 155 156 bool IsBindAny() const; // INADDR_ANY equivalent 157 [[nodiscard]] bool IsIPv4() const { return m_net == NET_IPV4; } // IPv4 mapped address (::FFFF:0:0/96, 0.0.0.0/0) 158 [[nodiscard]] bool IsIPv6() const { return m_net == NET_IPV6; } // IPv6 address (not mapped IPv4, not Tor) 159 bool IsRFC1918() const; // IPv4 private networks (10.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12) 160 bool IsRFC2544() const; // IPv4 inter-network communications (198.18.0.0/15) 161 bool IsRFC6598() const; // IPv4 ISP-level NAT (100.64.0.0/10) 162 bool IsRFC5737() const; // IPv4 documentation addresses (192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24) 163 bool IsRFC3849() const; // IPv6 documentation address (2001:0DB8::/32) 164 bool IsRFC3927() const; // IPv4 autoconfig (169.254.0.0/16) 165 bool IsRFC3964() const; // IPv6 6to4 tunnelling (2002::/16) 166 bool IsRFC4193() const; // IPv6 unique local (FC00::/7) 167 bool IsRFC4380() const; // IPv6 Teredo tunnelling (2001::/32) 168 bool IsRFC4843() const; // IPv6 ORCHID (deprecated) (2001:10::/28) 169 bool IsRFC7343() const; // IPv6 ORCHIDv2 (2001:20::/28) 170 bool IsRFC4862() const; // IPv6 autoconfig (FE80::/64) 171 bool IsRFC6052() const; // IPv6 well-known prefix for IPv4-embedded address (64:FF9B::/96) 172 bool IsRFC6145() const; // IPv6 IPv4-translated address (::FFFF:0:0:0/96) (actually defined in RFC2765) 173 bool IsHeNet() const; // IPv6 Hurricane Electric - https://he.net (2001:0470::/36) 174 [[nodiscard]] bool IsTor() const { return m_net == NET_ONION; } 175 [[nodiscard]] bool IsI2P() const { return m_net == NET_I2P; } 176 [[nodiscard]] bool IsCJDNS() const { return m_net == NET_CJDNS; } 177 [[nodiscard]] bool HasCJDNSPrefix() const { return m_addr[0] == CJDNS_PREFIX; } 178 bool IsLocal() const; 179 bool IsRoutable() const; 180 bool IsInternal() const; 181 bool IsValid() const; 182 183 /** 184 * Whether this object is a privacy network. 185 * TODO: consider adding IsCJDNS() here when more peers adopt CJDNS, see: 186 * https://github.com/bitcoin/bitcoin/pull/27411#issuecomment-1497176155 187 */ 188 [[nodiscard]] bool IsPrivacyNet() const { return IsTor() || IsI2P(); } 189 190 /** 191 * Check if the current object can be serialized in pre-ADDRv2/BIP155 format. 192 */ 193 bool IsAddrV1Compatible() const; 194 195 enum Network GetNetwork() const; 196 std::string ToStringAddr() const; 197 bool GetInAddr(struct in_addr* pipv4Addr) const; 198 Network GetNetClass() const; 199 200 //! For IPv4, mapped IPv4, SIIT translated IPv4, Teredo, 6to4 tunneled addresses, return the relevant IPv4 address as a uint32. 201 uint32_t GetLinkedIPv4() const; 202 //! Whether this address has a linked IPv4 address (see GetLinkedIPv4()). 203 bool HasLinkedIPv4() const; 204 205 std::vector<unsigned char> GetAddrBytes() const; 206 int GetReachabilityFrom(const CNetAddr& paddrPartner) const; 207 208 explicit CNetAddr(const struct in6_addr& pipv6Addr, const uint32_t scope = 0); 209 bool GetIn6Addr(struct in6_addr* pipv6Addr) const; 210 211 friend bool operator==(const CNetAddr& a, const CNetAddr& b); 212 friend bool operator!=(const CNetAddr& a, const CNetAddr& b) { return !(a == b); } 213 friend bool operator<(const CNetAddr& a, const CNetAddr& b); 214 215 /** 216 * Whether this address should be relayed to other peers even if we can't reach it ourselves. 217 */ 218 bool IsRelayable() const 219 { 220 return IsIPv4() || IsIPv6() || IsTor() || IsI2P() || IsCJDNS(); 221 } 222 223 enum class Encoding { 224 V1, 225 V2, //!< BIP155 encoding 226 }; 227 struct SerParams { 228 const Encoding enc; 229 SER_PARAMS_OPFUNC 230 }; 231 static constexpr SerParams V1{Encoding::V1}; 232 static constexpr SerParams V2{Encoding::V2}; 233 234 /** 235 * Serialize to a stream. 236 */ 237 template <typename Stream> 238 void Serialize(Stream& s) const 239 { 240 if (s.GetParams().enc == Encoding::V2) { 241 SerializeV2Stream(s); 242 } else { 243 SerializeV1Stream(s); 244 } 245 } 246 247 /** 248 * Unserialize from a stream. 249 */ 250 template <typename Stream> 251 void Unserialize(Stream& s) 252 { 253 if (s.GetParams().enc == Encoding::V2) { 254 UnserializeV2Stream(s); 255 } else { 256 UnserializeV1Stream(s); 257 } 258 } 259 260 /** 261 * BIP155 network ids recognized by this software. 262 */ 263 enum BIP155Network : uint8_t { 264 IPV4 = 1, 265 IPV6 = 2, 266 TORV2 = 3, 267 TORV3 = 4, 268 I2P = 5, 269 CJDNS = 6, 270 }; 271 272 friend class CSubNet; 273 274 private: 275 /** 276 * Parse a Tor address and set this object to it. 277 * @param[in] addr Address to parse, must be a valid C string, for example 278 * pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion. 279 * @returns Whether the operation was successful. 280 * @see CNetAddr::IsTor() 281 */ 282 bool SetTor(const std::string& addr); 283 284 /** 285 * Parse an I2P address and set this object to it. 286 * @param[in] addr Address to parse, must be a valid C string, for example 287 * ukeu3k5oycgaauneqgtnvselmt4yemvoilkln7jpvamvfx7dnkdq.b32.i2p. 288 * @returns Whether the operation was successful. 289 * @see CNetAddr::IsI2P() 290 */ 291 bool SetI2P(const std::string& addr); 292 293 /** 294 * Size of CNetAddr when serialized as ADDRv1 (pre-BIP155) (in bytes). 295 */ 296 static constexpr size_t V1_SERIALIZATION_SIZE = ADDR_IPV6_SIZE; 297 298 /** 299 * Maximum size of an address as defined in BIP155 (in bytes). 300 * This is only the size of the address, not the entire CNetAddr object 301 * when serialized. 302 */ 303 static constexpr size_t MAX_ADDRV2_SIZE = 512; 304 305 /** 306 * Get the BIP155 network id of this address. 307 * Must not be called for IsInternal() objects. 308 * @returns BIP155 network id, except TORV2 which is no longer supported. 309 */ 310 BIP155Network GetBIP155Network() const; 311 312 /** 313 * Set `m_net` from the provided BIP155 network id and size after validation. 314 * @retval true the network was recognized, is valid and `m_net` was set 315 * @retval false not recognised (from future?) and should be silently ignored 316 * @throws std::ios_base::failure if the network is one of the BIP155 founding 317 * networks (id 1..6) with wrong address size. 318 */ 319 bool SetNetFromBIP155Network(uint8_t possible_bip155_net, size_t address_size); 320 321 /** 322 * Serialize in pre-ADDRv2/BIP155 format to an array. 323 */ 324 void SerializeV1Array(uint8_t (&arr)[V1_SERIALIZATION_SIZE]) const 325 { 326 size_t prefix_size; 327 328 switch (m_net) { 329 case NET_IPV6: 330 assert(m_addr.size() == sizeof(arr)); 331 memcpy(arr, m_addr.data(), m_addr.size()); 332 return; 333 case NET_IPV4: 334 prefix_size = sizeof(IPV4_IN_IPV6_PREFIX); 335 assert(prefix_size + m_addr.size() == sizeof(arr)); 336 memcpy(arr, IPV4_IN_IPV6_PREFIX.data(), prefix_size); 337 memcpy(arr + prefix_size, m_addr.data(), m_addr.size()); 338 return; 339 case NET_INTERNAL: 340 prefix_size = sizeof(INTERNAL_IN_IPV6_PREFIX); 341 assert(prefix_size + m_addr.size() == sizeof(arr)); 342 memcpy(arr, INTERNAL_IN_IPV6_PREFIX.data(), prefix_size); 343 memcpy(arr + prefix_size, m_addr.data(), m_addr.size()); 344 return; 345 case NET_ONION: 346 case NET_I2P: 347 case NET_CJDNS: 348 break; 349 case NET_UNROUTABLE: 350 case NET_MAX: 351 assert(false); 352 } // no default case, so the compiler can warn about missing cases 353 354 // Serialize ONION, I2P and CJDNS as all-zeros. 355 memset(arr, 0x0, V1_SERIALIZATION_SIZE); 356 } 357 358 /** 359 * Serialize in pre-ADDRv2/BIP155 format to a stream. 360 */ 361 template <typename Stream> 362 void SerializeV1Stream(Stream& s) const 363 { 364 uint8_t serialized[V1_SERIALIZATION_SIZE]; 365 366 SerializeV1Array(serialized); 367 368 s << serialized; 369 } 370 371 /** 372 * Serialize as ADDRv2 / BIP155. 373 */ 374 template <typename Stream> 375 void SerializeV2Stream(Stream& s) const 376 { 377 if (IsInternal()) { 378 // Serialize NET_INTERNAL as embedded in IPv6. We need to 379 // serialize such addresses from addrman. 380 s << static_cast<uint8_t>(BIP155Network::IPV6); 381 s << COMPACTSIZE(ADDR_IPV6_SIZE); 382 SerializeV1Stream(s); 383 return; 384 } 385 386 s << static_cast<uint8_t>(GetBIP155Network()); 387 s << m_addr; 388 } 389 390 /** 391 * Unserialize from a pre-ADDRv2/BIP155 format from an array. 392 * 393 * This function is only called from UnserializeV1Stream() and is a wrapper 394 * for SetLegacyIPv6(); however, we keep it for symmetry with 395 * SerializeV1Array() to have pairs of ser/unser functions and to make clear 396 * that if one is altered, a corresponding reverse modification should be 397 * applied to the other. 398 */ 399 void UnserializeV1Array(uint8_t (&arr)[V1_SERIALIZATION_SIZE]) 400 { 401 // Use SetLegacyIPv6() so that m_net is set correctly. For example 402 // ::FFFF:0102:0304 should be set as m_net=NET_IPV4 (1.2.3.4). 403 SetLegacyIPv6(arr); 404 } 405 406 /** 407 * Unserialize from a pre-ADDRv2/BIP155 format from a stream. 408 */ 409 template <typename Stream> 410 void UnserializeV1Stream(Stream& s) 411 { 412 uint8_t serialized[V1_SERIALIZATION_SIZE]; 413 414 s >> serialized; 415 416 UnserializeV1Array(serialized); 417 } 418 419 /** 420 * Unserialize from a ADDRv2 / BIP155 format. 421 */ 422 template <typename Stream> 423 void UnserializeV2Stream(Stream& s) 424 { 425 uint8_t bip155_net; 426 s >> bip155_net; 427 428 size_t address_size; 429 s >> COMPACTSIZE(address_size); 430 431 if (address_size > MAX_ADDRV2_SIZE) { 432 throw std::ios_base::failure(strprintf( 433 "Address too long: %u > %u", address_size, MAX_ADDRV2_SIZE)); 434 } 435 436 m_scope_id = 0; 437 438 if (SetNetFromBIP155Network(bip155_net, address_size)) { 439 m_addr.resize(address_size); 440 s >> Span{m_addr}; 441 442 if (m_net != NET_IPV6) { 443 return; 444 } 445 446 // Do some special checks on IPv6 addresses. 447 448 // Recognize NET_INTERNAL embedded in IPv6, such addresses are not 449 // gossiped but could be coming from addrman, when unserializing from 450 // disk. 451 if (HasPrefix(m_addr, INTERNAL_IN_IPV6_PREFIX)) { 452 m_net = NET_INTERNAL; 453 memmove(m_addr.data(), m_addr.data() + INTERNAL_IN_IPV6_PREFIX.size(), 454 ADDR_INTERNAL_SIZE); 455 m_addr.resize(ADDR_INTERNAL_SIZE); 456 return; 457 } 458 459 if (!HasPrefix(m_addr, IPV4_IN_IPV6_PREFIX) && 460 !HasPrefix(m_addr, TORV2_IN_IPV6_PREFIX)) { 461 return; 462 } 463 464 // IPv4 and TORv2 are not supposed to be embedded in IPv6 (like in V1 465 // encoding). Unserialize as !IsValid(), thus ignoring them. 466 } else { 467 // If we receive an unknown BIP155 network id (from the future?) then 468 // ignore the address - unserialize as !IsValid(). 469 s.ignore(address_size); 470 } 471 472 // Mimic a default-constructed CNetAddr object which is !IsValid() and thus 473 // will not be gossiped, but continue reading next addresses from the stream. 474 m_net = NET_IPV6; 475 m_addr.assign(ADDR_IPV6_SIZE, 0x0); 476 } 477 }; 478 479 class CSubNet 480 { 481 protected: 482 /// Network (base) address 483 CNetAddr network; 484 /// Netmask, in network byte order 485 uint8_t netmask[16]; 486 /// Is this value valid? (only used to signal parse errors) 487 bool valid; 488 489 public: 490 /** 491 * Construct an invalid subnet (empty, `Match()` always returns false). 492 */ 493 CSubNet(); 494 495 /** 496 * Construct from a given network start and number of bits (CIDR mask). 497 * @param[in] addr Network start. Must be IPv4 or IPv6, otherwise an invalid subnet is 498 * created. 499 * @param[in] mask CIDR mask, must be in [0, 32] for IPv4 addresses and in [0, 128] for 500 * IPv6 addresses. Otherwise an invalid subnet is created. 501 */ 502 CSubNet(const CNetAddr& addr, uint8_t mask); 503 504 /** 505 * Construct from a given network start and mask. 506 * @param[in] addr Network start. Must be IPv4 or IPv6, otherwise an invalid subnet is 507 * created. 508 * @param[in] mask Network mask, must be of the same type as `addr` and not contain 0-bits 509 * followed by 1-bits. Otherwise an invalid subnet is created. 510 */ 511 CSubNet(const CNetAddr& addr, const CNetAddr& mask); 512 513 /** 514 * Construct a single-host subnet. 515 * @param[in] addr The sole address to be contained in the subnet, can also be non-IPv[46]. 516 */ 517 explicit CSubNet(const CNetAddr& addr); 518 519 bool Match(const CNetAddr& addr) const; 520 521 std::string ToString() const; 522 bool IsValid() const; 523 524 friend bool operator==(const CSubNet& a, const CSubNet& b); 525 friend bool operator!=(const CSubNet& a, const CSubNet& b) { return !(a == b); } 526 friend bool operator<(const CSubNet& a, const CSubNet& b); 527 }; 528 529 /** A combination of a network address (CNetAddr) and a (TCP) port */ 530 class CService : public CNetAddr 531 { 532 protected: 533 uint16_t port; // host order 534 535 public: 536 CService(); 537 CService(const CNetAddr& ip, uint16_t port); 538 CService(const struct in_addr& ipv4Addr, uint16_t port); 539 explicit CService(const struct sockaddr_in& addr); 540 uint16_t GetPort() const; 541 bool GetSockAddr(struct sockaddr* paddr, socklen_t* addrlen) const; 542 bool SetSockAddr(const struct sockaddr* paddr); 543 /** 544 * Get the address family 545 * @returns AF_UNSPEC if unspecified 546 */ 547 [[nodiscard]] sa_family_t GetSAFamily() const; 548 friend bool operator==(const CService& a, const CService& b); 549 friend bool operator!=(const CService& a, const CService& b) { return !(a == b); } 550 friend bool operator<(const CService& a, const CService& b); 551 std::vector<unsigned char> GetKey() const; 552 std::string ToStringAddrPort() const; 553 554 CService(const struct in6_addr& ipv6Addr, uint16_t port); 555 explicit CService(const struct sockaddr_in6& addr); 556 557 SERIALIZE_METHODS(CService, obj) 558 { 559 READWRITE(AsBase<CNetAddr>(obj), Using<BigEndianFormatter<2>>(obj.port)); 560 } 561 562 friend class CServiceHash; 563 friend CService MaybeFlipIPv6toCJDNS(const CService& service); 564 }; 565 566 class CServiceHash 567 { 568 public: 569 CServiceHash() 570 : m_salt_k0{GetRand<uint64_t>()}, 571 m_salt_k1{GetRand<uint64_t>()} 572 { 573 } 574 575 CServiceHash(uint64_t salt_k0, uint64_t salt_k1) : m_salt_k0{salt_k0}, m_salt_k1{salt_k1} {} 576 577 size_t operator()(const CService& a) const noexcept 578 { 579 CSipHasher hasher(m_salt_k0, m_salt_k1); 580 hasher.Write(a.m_net); 581 hasher.Write(a.port); 582 hasher.Write(a.m_addr); 583 return static_cast<size_t>(hasher.Finalize()); 584 } 585 586 private: 587 const uint64_t m_salt_k0; 588 const uint64_t m_salt_k1; 589 }; 590 591 #endif // BITCOIN_NETADDRESS_H