1  // Copyright (c) 2009-2010 Satoshi Nakamoto
   2  // Copyright (c) 2009-present The Bitcoin Core developers
   3  // Distributed under the MIT software license, see the accompanying
   4  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5  
   6  #include <netaddress.h>
   7  
   8  #include <crypto/common.h>
   9  #include <crypto/sha3.h>
  10  #include <hash.h>
  11  #include <prevector.h>
  12  #include <tinyformat.h>
  13  #include <util/strencodings.h>
  14  #include <util/string.h>
  15  
  16  #include <algorithm>
  17  #include <array>
  18  #include <cstdint>
  19  #include <ios>
  20  #include <iterator>
  21  #include <tuple>
  22  
  23  using util::ContainsNoNUL;
  24  using util::HasPrefix;
  25  
  26  CNetAddr::BIP155Network CNetAddr::GetBIP155Network() const
  27  {
  28      switch (m_net) {
  29      case NET_IPV4:
  30          return BIP155Network::IPV4;
  31      case NET_IPV6:
  32          return BIP155Network::IPV6;
  33      case NET_ONION:
  34          return BIP155Network::TORV3;
  35      case NET_I2P:
  36          return BIP155Network::I2P;
  37      case NET_CJDNS:
  38          return BIP155Network::CJDNS;
  39      case NET_INTERNAL:   // should have been handled before calling this function
  40      case NET_UNROUTABLE: // m_net is never and should not be set to NET_UNROUTABLE
  41      case NET_MAX:        // m_net is never and should not be set to NET_MAX
  42          assert(false);
  43      } // no default case, so the compiler can warn about missing cases
  44  
  45      assert(false);
  46  }
  47  
  48  bool CNetAddr::SetNetFromBIP155Network(uint8_t possible_bip155_net, size_t address_size)
  49  {
  50      switch (possible_bip155_net) {
  51      case BIP155Network::IPV4:
  52          if (address_size == ADDR_IPV4_SIZE) {
  53              m_net = NET_IPV4;
  54              return true;
  55          }
  56          throw std::ios_base::failure(
  57              strprintf("BIP155 IPv4 address with length %u (should be %u)", address_size,
  58                        ADDR_IPV4_SIZE));
  59      case BIP155Network::IPV6:
  60          if (address_size == ADDR_IPV6_SIZE) {
  61              m_net = NET_IPV6;
  62              return true;
  63          }
  64          throw std::ios_base::failure(
  65              strprintf("BIP155 IPv6 address with length %u (should be %u)", address_size,
  66                        ADDR_IPV6_SIZE));
  67      case BIP155Network::TORV3:
  68          if (address_size == ADDR_TORV3_SIZE) {
  69              m_net = NET_ONION;
  70              return true;
  71          }
  72          throw std::ios_base::failure(
  73              strprintf("BIP155 TORv3 address with length %u (should be %u)", address_size,
  74                        ADDR_TORV3_SIZE));
  75      case BIP155Network::I2P:
  76          if (address_size == ADDR_I2P_SIZE) {
  77              m_net = NET_I2P;
  78              return true;
  79          }
  80          throw std::ios_base::failure(
  81              strprintf("BIP155 I2P address with length %u (should be %u)", address_size,
  82                        ADDR_I2P_SIZE));
  83      case BIP155Network::CJDNS:
  84          if (address_size == ADDR_CJDNS_SIZE) {
  85              m_net = NET_CJDNS;
  86              return true;
  87          }
  88          throw std::ios_base::failure(
  89              strprintf("BIP155 CJDNS address with length %u (should be %u)", address_size,
  90                        ADDR_CJDNS_SIZE));
  91      }
  92  
  93      // Don't throw on addresses with unknown network ids (maybe from the future).
  94      // Instead silently drop them and have the unserialization code consume
  95      // subsequent ones which may be known to us.
  96      return false;
  97  }
  98  
  99  /**
 100   * Construct an unspecified IPv6 network address (::/128).
 101   *
 102   * @note This address is considered invalid by CNetAddr::IsValid()
 103   */
 104  CNetAddr::CNetAddr() = default;
 105  
 106  void CNetAddr::SetIP(const CNetAddr& ipIn)
 107  {
 108      // Size check.
 109      switch (ipIn.m_net) {
 110      case NET_IPV4:
 111          assert(ipIn.m_addr.size() == ADDR_IPV4_SIZE);
 112          break;
 113      case NET_IPV6:
 114          assert(ipIn.m_addr.size() == ADDR_IPV6_SIZE);
 115          break;
 116      case NET_ONION:
 117          assert(ipIn.m_addr.size() == ADDR_TORV3_SIZE);
 118          break;
 119      case NET_I2P:
 120          assert(ipIn.m_addr.size() == ADDR_I2P_SIZE);
 121          break;
 122      case NET_CJDNS:
 123          assert(ipIn.m_addr.size() == ADDR_CJDNS_SIZE);
 124          break;
 125      case NET_INTERNAL:
 126          assert(ipIn.m_addr.size() == ADDR_INTERNAL_SIZE);
 127          break;
 128      case NET_UNROUTABLE:
 129      case NET_MAX:
 130          assert(false);
 131      } // no default case, so the compiler can warn about missing cases
 132  
 133      m_net = ipIn.m_net;
 134      m_addr = ipIn.m_addr;
 135  }
 136  
 137  void CNetAddr::SetLegacyIPv6(std::span<const uint8_t> ipv6)
 138  {
 139      assert(ipv6.size() == ADDR_IPV6_SIZE);
 140  
 141      size_t skip{0};
 142  
 143      if (HasPrefix(ipv6, IPV4_IN_IPV6_PREFIX)) {
 144          // IPv4-in-IPv6
 145          m_net = NET_IPV4;
 146          skip = sizeof(IPV4_IN_IPV6_PREFIX);
 147      } else if (HasPrefix(ipv6, TORV2_IN_IPV6_PREFIX)) {
 148          // TORv2-in-IPv6 (unsupported). Unserialize as !IsValid(), thus ignoring them.
 149          // Mimic a default-constructed CNetAddr object which is !IsValid() and thus
 150          // will not be gossiped, but continue reading next addresses from the stream.
 151          m_net = NET_IPV6;
 152          m_addr.assign(ADDR_IPV6_SIZE, 0x0);
 153          return;
 154      } else if (HasPrefix(ipv6, INTERNAL_IN_IPV6_PREFIX)) {
 155          // Internal-in-IPv6
 156          m_net = NET_INTERNAL;
 157          skip = sizeof(INTERNAL_IN_IPV6_PREFIX);
 158      } else {
 159          // IPv6
 160          m_net = NET_IPV6;
 161      }
 162  
 163      m_addr.assign(ipv6.begin() + skip, ipv6.end());
 164  }
 165  
 166  /**
 167   * Create an "internal" address that represents a name or FQDN. AddrMan uses
 168   * these fake addresses to keep track of which DNS seeds were used.
 169   * @returns Whether or not the operation was successful.
 170   * @see NET_INTERNAL, INTERNAL_IN_IPV6_PREFIX, CNetAddr::IsInternal(), CNetAddr::IsRFC4193()
 171   */
 172  bool CNetAddr::SetInternal(const std::string &name)
 173  {
 174      if (name.empty()) {
 175          return false;
 176      }
 177      m_net = NET_INTERNAL;
 178      unsigned char hash[32] = {};
 179      CSHA256().Write((const unsigned char*)name.data(), name.size()).Finalize(hash);
 180      m_addr.assign(hash, hash + ADDR_INTERNAL_SIZE);
 181      return true;
 182  }
 183  
 184  namespace torv3 {
 185  // https://gitweb.torproject.org/torspec.git/tree/rend-spec-v3.txt?id=7116c9cdaba248aae07a3f1d0e15d9dd102f62c5#n2175
 186  static constexpr size_t CHECKSUM_LEN = 2;
 187  static const unsigned char VERSION[] = {3};
 188  static constexpr size_t TOTAL_LEN = ADDR_TORV3_SIZE + CHECKSUM_LEN + sizeof(VERSION);
 189  
 190  static void Checksum(std::span<const uint8_t> addr_pubkey, uint8_t (&checksum)[CHECKSUM_LEN])
 191  {
 192      // TORv3 CHECKSUM = H(".onion checksum" | PUBKEY | VERSION)[:2]
 193      static const unsigned char prefix[] = ".onion checksum";
 194      static constexpr size_t prefix_len = 15;
 195  
 196      SHA3_256 hasher;
 197  
 198      hasher.Write(std::span{prefix}.first(prefix_len));
 199      hasher.Write(addr_pubkey);
 200      hasher.Write(VERSION);
 201  
 202      uint8_t checksum_full[SHA3_256::OUTPUT_SIZE];
 203  
 204      hasher.Finalize(checksum_full);
 205  
 206      memcpy(checksum, checksum_full, sizeof(checksum));
 207  }
 208  
 209  }; // namespace torv3
 210  
 211  bool CNetAddr::SetSpecial(const std::string& addr)
 212  {
 213      if (!ContainsNoNUL(addr)) {
 214          return false;
 215      }
 216  
 217      if (SetTor(addr)) {
 218          return true;
 219      }
 220  
 221      if (SetI2P(addr)) {
 222          return true;
 223      }
 224  
 225      return false;
 226  }
 227  
 228  bool CNetAddr::SetTor(const std::string& addr)
 229  {
 230      static const char* suffix{".onion"};
 231      static constexpr size_t suffix_len{6};
 232  
 233      if (addr.size() <= suffix_len || addr.substr(addr.size() - suffix_len) != suffix) {
 234          return false;
 235      }
 236  
 237      auto input = DecodeBase32(std::string_view{addr}.substr(0, addr.size() - suffix_len));
 238  
 239      if (!input) {
 240          return false;
 241      }
 242  
 243      if (input->size() == torv3::TOTAL_LEN) {
 244          std::span<const uint8_t> input_pubkey{input->data(), ADDR_TORV3_SIZE};
 245          std::span<const uint8_t> input_checksum{input->data() + ADDR_TORV3_SIZE, torv3::CHECKSUM_LEN};
 246          std::span<const uint8_t> input_version{input->data() + ADDR_TORV3_SIZE + torv3::CHECKSUM_LEN, sizeof(torv3::VERSION)};
 247  
 248          if (!std::ranges::equal(input_version, torv3::VERSION)) {
 249              return false;
 250          }
 251  
 252          uint8_t calculated_checksum[torv3::CHECKSUM_LEN];
 253          torv3::Checksum(input_pubkey, calculated_checksum);
 254  
 255          if (!std::ranges::equal(input_checksum, calculated_checksum)) {
 256              return false;
 257          }
 258  
 259          m_net = NET_ONION;
 260          m_addr.assign(input_pubkey.begin(), input_pubkey.end());
 261          return true;
 262      }
 263  
 264      return false;
 265  }
 266  
 267  bool CNetAddr::SetI2P(const std::string& addr)
 268  {
 269      // I2P addresses that we support consist of 52 base32 characters + ".b32.i2p".
 270      static constexpr size_t b32_len{52};
 271      static const char* suffix{".b32.i2p"};
 272      static constexpr size_t suffix_len{8};
 273  
 274      if (addr.size() != b32_len + suffix_len || ToLower(addr.substr(b32_len)) != suffix) {
 275          return false;
 276      }
 277  
 278      // Remove the ".b32.i2p" suffix and pad to a multiple of 8 chars, so DecodeBase32()
 279      // can decode it.
 280      const std::string b32_padded = addr.substr(0, b32_len) + "====";
 281  
 282      auto address_bytes = DecodeBase32(b32_padded);
 283  
 284      if (!address_bytes || address_bytes->size() != ADDR_I2P_SIZE) {
 285          return false;
 286      }
 287  
 288      m_net = NET_I2P;
 289      m_addr.assign(address_bytes->begin(), address_bytes->end());
 290  
 291      return true;
 292  }
 293  
 294  CNetAddr::CNetAddr(const struct in_addr& ipv4Addr)
 295  {
 296      m_net = NET_IPV4;
 297      const uint8_t* ptr = reinterpret_cast<const uint8_t*>(&ipv4Addr);
 298      m_addr.assign(ptr, ptr + ADDR_IPV4_SIZE);
 299  }
 300  
 301  CNetAddr::CNetAddr(const struct in6_addr& ipv6Addr, const uint32_t scope)
 302  {
 303      SetLegacyIPv6({reinterpret_cast<const uint8_t*>(&ipv6Addr), sizeof(ipv6Addr)});
 304      m_scope_id = scope;
 305  }
 306  
 307  bool CNetAddr::IsBindAny() const
 308  {
 309      if (!IsIPv4() && !IsIPv6()) {
 310          return false;
 311      }
 312      return std::all_of(m_addr.begin(), m_addr.end(), [](uint8_t b) { return b == 0; });
 313  }
 314  
 315  bool CNetAddr::IsRFC1918() const
 316  {
 317      return IsIPv4() && (
 318          m_addr[0] == 10 ||
 319          (m_addr[0] == 192 && m_addr[1] == 168) ||
 320          (m_addr[0] == 172 && m_addr[1] >= 16 && m_addr[1] <= 31));
 321  }
 322  
 323  bool CNetAddr::IsRFC2544() const
 324  {
 325      return IsIPv4() && m_addr[0] == 198 && (m_addr[1] == 18 || m_addr[1] == 19);
 326  }
 327  
 328  bool CNetAddr::IsRFC3927() const
 329  {
 330      return IsIPv4() && HasPrefix(m_addr, std::array<uint8_t, 2>{169, 254});
 331  }
 332  
 333  bool CNetAddr::IsRFC6598() const
 334  {
 335      return IsIPv4() && m_addr[0] == 100 && m_addr[1] >= 64 && m_addr[1] <= 127;
 336  }
 337  
 338  bool CNetAddr::IsRFC5737() const
 339  {
 340      return IsIPv4() && (HasPrefix(m_addr, std::array<uint8_t, 3>{192, 0, 2}) ||
 341                          HasPrefix(m_addr, std::array<uint8_t, 3>{198, 51, 100}) ||
 342                          HasPrefix(m_addr, std::array<uint8_t, 3>{203, 0, 113}));
 343  }
 344  
 345  bool CNetAddr::IsRFC3849() const
 346  {
 347      return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 4>{0x20, 0x01, 0x0D, 0xB8});
 348  }
 349  
 350  bool CNetAddr::IsRFC3964() const
 351  {
 352      return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 2>{0x20, 0x02});
 353  }
 354  
 355  bool CNetAddr::IsRFC6052() const
 356  {
 357      return IsIPv6() &&
 358             HasPrefix(m_addr, std::array<uint8_t, 12>{0x00, 0x64, 0xFF, 0x9B, 0x00, 0x00,
 359                                                       0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
 360  }
 361  
 362  bool CNetAddr::IsRFC4380() const
 363  {
 364      return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 4>{0x20, 0x01, 0x00, 0x00});
 365  }
 366  
 367  bool CNetAddr::IsRFC4862() const
 368  {
 369      return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 8>{0xFE, 0x80, 0x00, 0x00,
 370                                                                  0x00, 0x00, 0x00, 0x00});
 371  }
 372  
 373  bool CNetAddr::IsRFC4193() const
 374  {
 375      return IsIPv6() && (m_addr[0] & 0xFE) == 0xFC;
 376  }
 377  
 378  bool CNetAddr::IsRFC6145() const
 379  {
 380      return IsIPv6() &&
 381             HasPrefix(m_addr, std::array<uint8_t, 12>{0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 382                                                       0x00, 0x00, 0xFF, 0xFF, 0x00, 0x00});
 383  }
 384  
 385  bool CNetAddr::IsRFC4843() const
 386  {
 387      return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 3>{0x20, 0x01, 0x00}) &&
 388             (m_addr[3] & 0xF0) == 0x10;
 389  }
 390  
 391  bool CNetAddr::IsRFC7343() const
 392  {
 393      return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 3>{0x20, 0x01, 0x00}) &&
 394             (m_addr[3] & 0xF0) == 0x20;
 395  }
 396  
 397  bool CNetAddr::IsHeNet() const
 398  {
 399      return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 4>{0x20, 0x01, 0x04, 0x70});
 400  }
 401  
 402  bool CNetAddr::IsLocal() const
 403  {
 404      // IPv4 loopback (127.0.0.0/8 or 0.0.0.0/8)
 405      if (IsIPv4() && (m_addr[0] == 127 || m_addr[0] == 0)) {
 406          return true;
 407      }
 408  
 409      // IPv6 loopback (::1/128)
 410      static const unsigned char pchLocal[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
 411      if (IsIPv6() && memcmp(m_addr.data(), pchLocal, sizeof(pchLocal)) == 0) {
 412          return true;
 413      }
 414  
 415      return false;
 416  }
 417  
 418  /**
 419   * @returns Whether or not this network address is a valid address that @a could
 420   *          be used to refer to an actual host.
 421   *
 422   * @note A valid address may or may not be publicly routable on the global
 423   *       internet. As in, the set of valid addresses is a superset of the set of
 424   *       publicly routable addresses.
 425   *
 426   * @see CNetAddr::IsRoutable()
 427   */
 428  bool CNetAddr::IsValid() const
 429  {
 430      // unspecified IPv6 address (::/128)
 431      unsigned char ipNone6[16] = {};
 432      if (IsIPv6() && memcmp(m_addr.data(), ipNone6, sizeof(ipNone6)) == 0) {
 433          return false;
 434      }
 435  
 436      if (IsCJDNS() && !HasCJDNSPrefix()) {
 437          return false;
 438      }
 439  
 440      // documentation IPv6 address
 441      if (IsRFC3849())
 442          return false;
 443  
 444      if (IsInternal())
 445          return false;
 446  
 447      if (IsIPv4()) {
 448          const uint32_t addr = ReadBE32(m_addr.data());
 449          if (addr == INADDR_ANY || addr == INADDR_NONE) {
 450              return false;
 451          }
 452      }
 453  
 454      return true;
 455  }
 456  
 457  /**
 458   * @returns Whether or not this network address is publicly routable on the
 459   *          global internet.
 460   *
 461   * @note A routable address is always valid. As in, the set of routable addresses
 462   *       is a subset of the set of valid addresses.
 463   *
 464   * @see CNetAddr::IsValid()
 465   */
 466  bool CNetAddr::IsRoutable() const
 467  {
 468      return IsValid() && !(IsRFC1918() || IsRFC2544() || IsRFC3927() || IsRFC4862() || IsRFC6598() || IsRFC5737() || IsRFC4193() || IsRFC4843() || IsRFC7343() || IsLocal() || IsInternal());
 469  }
 470  
 471  /**
 472   * @returns Whether or not this is a dummy address that represents a name.
 473   *
 474   * @see CNetAddr::SetInternal(const std::string &)
 475   */
 476  bool CNetAddr::IsInternal() const
 477  {
 478     return m_net == NET_INTERNAL;
 479  }
 480  
 481  bool CNetAddr::IsAddrV1Compatible() const
 482  {
 483      switch (m_net) {
 484      case NET_IPV4:
 485      case NET_IPV6:
 486      case NET_INTERNAL:
 487          return true;
 488      case NET_ONION:
 489      case NET_I2P:
 490      case NET_CJDNS:
 491          return false;
 492      case NET_UNROUTABLE: // m_net is never and should not be set to NET_UNROUTABLE
 493      case NET_MAX:        // m_net is never and should not be set to NET_MAX
 494          assert(false);
 495      } // no default case, so the compiler can warn about missing cases
 496  
 497      assert(false);
 498  }
 499  
 500  enum Network CNetAddr::GetNetwork() const
 501  {
 502      if (IsInternal())
 503          return NET_INTERNAL;
 504  
 505      if (!IsRoutable())
 506          return NET_UNROUTABLE;
 507  
 508      return m_net;
 509  }
 510  
 511  static std::string IPv4ToString(std::span<const uint8_t> a)
 512  {
 513      return strprintf("%u.%u.%u.%u", a[0], a[1], a[2], a[3]);
 514  }
 515  
 516  // Return an IPv6 address text representation with zero compression as described in RFC 5952
 517  // ("A Recommendation for IPv6 Address Text Representation").
 518  static std::string IPv6ToString(std::span<const uint8_t> a, uint32_t scope_id)
 519  {
 520      assert(a.size() == ADDR_IPV6_SIZE);
 521      const std::array groups{
 522          ReadBE16(&a[0]),
 523          ReadBE16(&a[2]),
 524          ReadBE16(&a[4]),
 525          ReadBE16(&a[6]),
 526          ReadBE16(&a[8]),
 527          ReadBE16(&a[10]),
 528          ReadBE16(&a[12]),
 529          ReadBE16(&a[14]),
 530      };
 531  
 532      // The zero compression implementation is inspired by Rust's std::net::Ipv6Addr, see
 533      // https://github.com/rust-lang/rust/blob/cc4103089f40a163f6d143f06359cba7043da29b/library/std/src/net/ip.rs#L1635-L1683
 534      struct ZeroSpan {
 535          size_t start_index{0};
 536          size_t len{0};
 537      };
 538  
 539      // Find longest sequence of consecutive all-zero fields. Use first zero sequence if two or more
 540      // zero sequences of equal length are found.
 541      ZeroSpan longest, current;
 542      for (size_t i{0}; i < groups.size(); ++i) {
 543          if (groups[i] != 0) {
 544              current = {i + 1, 0};
 545              continue;
 546          }
 547          current.len += 1;
 548          if (current.len > longest.len) {
 549              longest = current;
 550          }
 551      }
 552  
 553      std::string r;
 554      r.reserve(39);
 555      for (size_t i{0}; i < groups.size(); ++i) {
 556          // Replace the longest sequence of consecutive all-zero fields with two colons ("::").
 557          if (longest.len >= 2 && i >= longest.start_index && i < longest.start_index + longest.len) {
 558              if (i == longest.start_index) {
 559                  r += "::";
 560              }
 561              continue;
 562          }
 563          r += strprintf("%s%x", ((!r.empty() && r.back() != ':') ? ":" : ""), groups[i]);
 564      }
 565  
 566      if (scope_id != 0) {
 567          r += strprintf("%%%u", scope_id);
 568      }
 569  
 570      return r;
 571  }
 572  
 573  std::string OnionToString(std::span<const uint8_t> addr)
 574  {
 575      uint8_t checksum[torv3::CHECKSUM_LEN];
 576      torv3::Checksum(addr, checksum);
 577      // TORv3 onion_address = base32(PUBKEY | CHECKSUM | VERSION) + ".onion"
 578      prevector<torv3::TOTAL_LEN, uint8_t> address{addr.begin(), addr.end()};
 579      address.insert(address.end(), checksum, checksum + torv3::CHECKSUM_LEN);
 580      address.insert(address.end(), torv3::VERSION, torv3::VERSION + sizeof(torv3::VERSION));
 581      return EncodeBase32(address) + ".onion";
 582  }
 583  
 584  std::string CNetAddr::ToStringAddr() const
 585  {
 586      switch (m_net) {
 587      case NET_IPV4:
 588          return IPv4ToString(m_addr);
 589      case NET_IPV6:
 590          return IPv6ToString(m_addr, m_scope_id);
 591      case NET_ONION:
 592          return OnionToString(m_addr);
 593      case NET_I2P:
 594          return EncodeBase32(m_addr, false /* don't pad with = */) + ".b32.i2p";
 595      case NET_CJDNS:
 596          return IPv6ToString(m_addr, 0);
 597      case NET_INTERNAL:
 598          return EncodeBase32(m_addr) + ".internal";
 599      case NET_UNROUTABLE: // m_net is never and should not be set to NET_UNROUTABLE
 600      case NET_MAX:        // m_net is never and should not be set to NET_MAX
 601          assert(false);
 602      } // no default case, so the compiler can warn about missing cases
 603  
 604      assert(false);
 605  }
 606  
 607  bool operator==(const CNetAddr& a, const CNetAddr& b)
 608  {
 609      return a.m_net == b.m_net && a.m_addr == b.m_addr;
 610  }
 611  
 612  bool operator<(const CNetAddr& a, const CNetAddr& b)
 613  {
 614      return std::tie(a.m_net, a.m_addr) < std::tie(b.m_net, b.m_addr);
 615  }
 616  
 617  /**
 618   * Try to get our IPv4 address.
 619   *
 620   * @param[out] pipv4Addr The in_addr struct to which to copy.
 621   *
 622   * @returns Whether or not the operation was successful, in particular, whether
 623   *          or not our address was an IPv4 address.
 624   *
 625   * @see CNetAddr::IsIPv4()
 626   */
 627  bool CNetAddr::GetInAddr(struct in_addr* pipv4Addr) const
 628  {
 629      if (!IsIPv4())
 630          return false;
 631      assert(sizeof(*pipv4Addr) == m_addr.size());
 632      memcpy(pipv4Addr, m_addr.data(), m_addr.size());
 633      return true;
 634  }
 635  
 636  /**
 637   * Try to get our IPv6 (or CJDNS) address.
 638   *
 639   * @param[out] pipv6Addr The in6_addr struct to which to copy.
 640   *
 641   * @returns Whether or not the operation was successful, in particular, whether
 642   *          or not our address was an IPv6 address.
 643   *
 644   * @see CNetAddr::IsIPv6()
 645   */
 646  bool CNetAddr::GetIn6Addr(struct in6_addr* pipv6Addr) const
 647  {
 648      if (!IsIPv6() && !IsCJDNS()) {
 649          return false;
 650      }
 651      assert(sizeof(*pipv6Addr) == m_addr.size());
 652      memcpy(pipv6Addr, m_addr.data(), m_addr.size());
 653      return true;
 654  }
 655  
 656  bool CNetAddr::HasLinkedIPv4() const
 657  {
 658      return IsRoutable() && (IsIPv4() || IsRFC6145() || IsRFC6052() || IsRFC3964() || IsRFC4380());
 659  }
 660  
 661  uint32_t CNetAddr::GetLinkedIPv4() const
 662  {
 663      if (IsIPv4()) {
 664          return ReadBE32(m_addr.data());
 665      } else if (IsRFC6052() || IsRFC6145()) {
 666          // mapped IPv4, SIIT translated IPv4: the IPv4 address is the last 4 bytes of the address
 667          return ReadBE32(std::span{m_addr}.last(ADDR_IPV4_SIZE).data());
 668      } else if (IsRFC3964()) {
 669          // 6to4 tunneled IPv4: the IPv4 address is in bytes 2-6
 670          return ReadBE32(std::span{m_addr}.subspan(2, ADDR_IPV4_SIZE).data());
 671      } else if (IsRFC4380()) {
 672          // Teredo tunneled IPv4: the IPv4 address is in the last 4 bytes of the address, but bitflipped
 673          return ~ReadBE32(std::span{m_addr}.last(ADDR_IPV4_SIZE).data());
 674      }
 675      assert(false);
 676  }
 677  
 678  Network CNetAddr::GetNetClass() const
 679  {
 680      // Make sure that if we return NET_IPV6, then IsIPv6() is true. The callers expect that.
 681  
 682      // Check for "internal" first because such addresses are also !IsRoutable()
 683      // and we don't want to return NET_UNROUTABLE in that case.
 684      if (IsInternal()) {
 685          return NET_INTERNAL;
 686      }
 687      if (!IsRoutable()) {
 688          return NET_UNROUTABLE;
 689      }
 690      if (HasLinkedIPv4()) {
 691          return NET_IPV4;
 692      }
 693      return m_net;
 694  }
 695  
 696  std::vector<unsigned char> CNetAddr::GetAddrBytes() const
 697  {
 698      if (IsAddrV1Compatible()) {
 699          uint8_t serialized[V1_SERIALIZATION_SIZE];
 700          SerializeV1Array(serialized);
 701          return {std::begin(serialized), std::end(serialized)};
 702      }
 703      return std::vector<unsigned char>(m_addr.begin(), m_addr.end());
 704  }
 705  
 706  // private extensions to enum Network, only returned by GetExtNetwork,
 707  // and only used in GetReachabilityFrom
 708  static const int NET_TEREDO = NET_MAX;
 709  int static GetExtNetwork(const CNetAddr& addr)
 710  {
 711      if (addr.IsRFC4380())
 712          return NET_TEREDO;
 713      return addr.GetNetwork();
 714  }
 715  
 716  /** Calculates a metric for how reachable (*this) is from a given partner */
 717  int CNetAddr::GetReachabilityFrom(const CNetAddr& paddrPartner) const
 718  {
 719      enum Reachability {
 720          REACH_UNREACHABLE,
 721          REACH_DEFAULT,
 722          REACH_TEREDO,
 723          REACH_IPV6_WEAK,
 724          REACH_IPV4,
 725          REACH_IPV6_STRONG,
 726          REACH_PRIVATE
 727      };
 728  
 729      if (!IsRoutable() || IsInternal())
 730          return REACH_UNREACHABLE;
 731  
 732      int ourNet = GetExtNetwork(*this);
 733      int theirNet = GetExtNetwork(paddrPartner);
 734      bool fTunnel = IsRFC3964() || IsRFC6052() || IsRFC6145();
 735  
 736      switch(theirNet) {
 737      case NET_IPV4:
 738          switch(ourNet) {
 739          default:       return REACH_DEFAULT;
 740          case NET_IPV4: return REACH_IPV4;
 741          }
 742      case NET_IPV6:
 743          switch(ourNet) {
 744          default:         return REACH_DEFAULT;
 745          case NET_TEREDO: return REACH_TEREDO;
 746          case NET_IPV4:   return REACH_IPV4;
 747          case NET_IPV6:   return fTunnel ? REACH_IPV6_WEAK : REACH_IPV6_STRONG; // only prefer giving our IPv6 address if it's not tunnelled
 748          }
 749      case NET_ONION:
 750          switch(ourNet) {
 751          default:         return REACH_DEFAULT;
 752          case NET_IPV4:   return REACH_IPV4; // Tor users can connect to IPv4 as well
 753          case NET_ONION:    return REACH_PRIVATE;
 754          }
 755      case NET_I2P:
 756          switch (ourNet) {
 757          case NET_I2P: return REACH_PRIVATE;
 758          default: return REACH_DEFAULT;
 759          }
 760      case NET_CJDNS:
 761          switch (ourNet) {
 762          case NET_CJDNS: return REACH_PRIVATE;
 763          default: return REACH_DEFAULT;
 764          }
 765      case NET_TEREDO:
 766          switch(ourNet) {
 767          default:          return REACH_DEFAULT;
 768          case NET_TEREDO:  return REACH_TEREDO;
 769          case NET_IPV6:    return REACH_IPV6_WEAK;
 770          case NET_IPV4:    return REACH_IPV4;
 771          }
 772      case NET_UNROUTABLE:
 773      default:
 774          switch(ourNet) {
 775          default:          return REACH_DEFAULT;
 776          case NET_TEREDO:  return REACH_TEREDO;
 777          case NET_IPV6:    return REACH_IPV6_WEAK;
 778          case NET_IPV4:    return REACH_IPV4;
 779          case NET_ONION:     return REACH_PRIVATE; // either from Tor, or don't care about our address
 780          }
 781      }
 782  }
 783  
 784  CService::CService() : port(0)
 785  {
 786  }
 787  
 788  CService::CService(const CNetAddr& cip, uint16_t portIn) : CNetAddr(cip), port(portIn)
 789  {
 790  }
 791  
 792  CService::CService(const struct in_addr& ipv4Addr, uint16_t portIn) : CNetAddr(ipv4Addr), port(portIn)
 793  {
 794  }
 795  
 796  CService::CService(const struct in6_addr& ipv6Addr, uint16_t portIn) : CNetAddr(ipv6Addr), port(portIn)
 797  {
 798  }
 799  
 800  CService::CService(const struct sockaddr_in& addr) : CNetAddr(addr.sin_addr), port(ntohs(addr.sin_port))
 801  {
 802      assert(addr.sin_family == AF_INET);
 803  }
 804  
 805  CService::CService(const struct sockaddr_in6 &addr) : CNetAddr(addr.sin6_addr, addr.sin6_scope_id), port(ntohs(addr.sin6_port))
 806  {
 807     assert(addr.sin6_family == AF_INET6);
 808  }
 809  
 810  bool CService::SetSockAddr(const struct sockaddr *paddr, socklen_t addrlen)
 811  {
 812      switch (paddr->sa_family) {
 813      case AF_INET:
 814          if (addrlen != sizeof(struct sockaddr_in)) return false;
 815          *this = CService(*(const struct sockaddr_in*)paddr);
 816          return true;
 817      case AF_INET6:
 818          if (addrlen != sizeof(struct sockaddr_in6)) return false;
 819          *this = CService(*(const struct sockaddr_in6*)paddr);
 820          return true;
 821      default:
 822          return false;
 823      }
 824  }
 825  
 826  sa_family_t CService::GetSAFamily() const
 827  {
 828      switch (m_net) {
 829      case NET_IPV4:
 830          return AF_INET;
 831      case NET_IPV6:
 832      case NET_CJDNS:
 833          return AF_INET6;
 834      default:
 835          return AF_UNSPEC;
 836      }
 837  }
 838  
 839  uint16_t CService::GetPort() const
 840  {
 841      return port;
 842  }
 843  
 844  bool operator==(const CService& a, const CService& b)
 845  {
 846      return static_cast<CNetAddr>(a) == static_cast<CNetAddr>(b) && a.port == b.port;
 847  }
 848  
 849  bool operator<(const CService& a, const CService& b)
 850  {
 851      return static_cast<CNetAddr>(a) < static_cast<CNetAddr>(b) || (static_cast<CNetAddr>(a) == static_cast<CNetAddr>(b) && a.port < b.port);
 852  }
 853  
 854  /**
 855   * Obtain the IPv4/6 socket address this represents.
 856   *
 857   * @param[out] paddr The obtained socket address.
 858   * @param[in,out] addrlen The size, in bytes, of the address structure pointed
 859   *                        to by paddr. The value that's pointed to by this
 860   *                        parameter might change after calling this function if
 861   *                        the size of the corresponding address structure
 862   *                        changed.
 863   *
 864   * @returns Whether or not the operation was successful.
 865   */
 866  bool CService::GetSockAddr(struct sockaddr* paddr, socklen_t *addrlen) const
 867  {
 868      if (IsIPv4()) {
 869          if (*addrlen < (socklen_t)sizeof(struct sockaddr_in))
 870              return false;
 871          *addrlen = sizeof(struct sockaddr_in);
 872          struct sockaddr_in *paddrin = (struct sockaddr_in*)paddr;
 873          memset(paddrin, 0, *addrlen);
 874          if (!GetInAddr(&paddrin->sin_addr))
 875              return false;
 876          paddrin->sin_family = AF_INET;
 877          paddrin->sin_port = htons(port);
 878          return true;
 879      }
 880      if (IsIPv6() || IsCJDNS()) {
 881          if (*addrlen < (socklen_t)sizeof(struct sockaddr_in6))
 882              return false;
 883          *addrlen = sizeof(struct sockaddr_in6);
 884          struct sockaddr_in6 *paddrin6 = (struct sockaddr_in6*)paddr;
 885          memset(paddrin6, 0, *addrlen);
 886          if (!GetIn6Addr(&paddrin6->sin6_addr))
 887              return false;
 888          paddrin6->sin6_scope_id = m_scope_id;
 889          paddrin6->sin6_family = AF_INET6;
 890          paddrin6->sin6_port = htons(port);
 891          return true;
 892      }
 893      return false;
 894  }
 895  
 896  /**
 897   * @returns An identifier unique to this service's address and port number.
 898   */
 899  std::vector<unsigned char> CService::GetKey() const
 900  {
 901      auto key = GetAddrBytes();
 902      key.push_back(port / 0x100); // most significant byte of our port
 903      key.push_back(port & 0x0FF); // least significant byte of our port
 904      return key;
 905  }
 906  
 907  std::string CService::ToStringAddrPort() const
 908  {
 909      const auto port_str = strprintf("%u", port);
 910  
 911      if (IsIPv4() || IsTor() || IsI2P() || IsInternal()) {
 912          return ToStringAddr() + ":" + port_str;
 913      } else {
 914          return "[" + ToStringAddr() + "]:" + port_str;
 915      }
 916  }
 917  
 918  CSubNet::CSubNet():
 919      valid(false)
 920  {
 921      memset(netmask, 0, sizeof(netmask));
 922  }
 923  
 924  CSubNet::CSubNet(const CNetAddr& addr, uint8_t mask) : CSubNet()
 925  {
 926      valid = (addr.IsIPv4() && mask <= ADDR_IPV4_SIZE * 8) ||
 927              (addr.IsIPv6() && mask <= ADDR_IPV6_SIZE * 8);
 928      if (!valid) {
 929          return;
 930      }
 931  
 932      assert(mask <= sizeof(netmask) * 8);
 933  
 934      network = addr;
 935  
 936      uint8_t n = mask;
 937      for (size_t i = 0; i < network.m_addr.size(); ++i) {
 938          const uint8_t bits = n < 8 ? n : 8;
 939          netmask[i] = (uint8_t)((uint8_t)0xFF << (8 - bits)); // Set first bits.
 940          network.m_addr[i] &= netmask[i]; // Normalize network according to netmask.
 941          n -= bits;
 942      }
 943  }
 944  
 945  /**
 946   * @returns The number of 1-bits in the prefix of the specified subnet mask. If
 947   *          the specified subnet mask is not a valid one, -1.
 948   */
 949  static inline int NetmaskBits(uint8_t x)
 950  {
 951      switch(x) {
 952      case 0x00: return 0;
 953      case 0x80: return 1;
 954      case 0xc0: return 2;
 955      case 0xe0: return 3;
 956      case 0xf0: return 4;
 957      case 0xf8: return 5;
 958      case 0xfc: return 6;
 959      case 0xfe: return 7;
 960      case 0xff: return 8;
 961      default: return -1;
 962      }
 963  }
 964  
 965  CSubNet::CSubNet(const CNetAddr& addr, const CNetAddr& mask) : CSubNet()
 966  {
 967      valid = (addr.IsIPv4() || addr.IsIPv6()) && addr.m_net == mask.m_net;
 968      if (!valid) {
 969          return;
 970      }
 971      // Check if `mask` contains 1-bits after 0-bits (which is an invalid netmask).
 972      bool zeros_found = false;
 973      for (auto b : mask.m_addr) {
 974          const int num_bits = NetmaskBits(b);
 975          if (num_bits == -1 || (zeros_found && num_bits != 0)) {
 976              valid = false;
 977              return;
 978          }
 979          if (num_bits < 8) {
 980              zeros_found = true;
 981          }
 982      }
 983  
 984      assert(mask.m_addr.size() <= sizeof(netmask));
 985  
 986      memcpy(netmask, mask.m_addr.data(), mask.m_addr.size());
 987  
 988      network = addr;
 989  
 990      // Normalize network according to netmask
 991      for (size_t x = 0; x < network.m_addr.size(); ++x) {
 992          network.m_addr[x] &= netmask[x];
 993      }
 994  }
 995  
 996  CSubNet::CSubNet(const CNetAddr& addr) : CSubNet()
 997  {
 998      switch (addr.m_net) {
 999      case NET_IPV4:
1000      case NET_IPV6:
1001          valid = true;
1002          assert(addr.m_addr.size() <= sizeof(netmask));
1003          memset(netmask, 0xFF, addr.m_addr.size());
1004          break;
1005      case NET_ONION:
1006      case NET_I2P:
1007      case NET_CJDNS:
1008          valid = true;
1009          break;
1010      case NET_INTERNAL:
1011      case NET_UNROUTABLE:
1012      case NET_MAX:
1013          return;
1014      }
1015  
1016      network = addr;
1017  }
1018  
1019  /**
1020   * @returns True if this subnet is valid, the specified address is valid, and
1021   *          the specified address belongs in this subnet.
1022   */
1023  bool CSubNet::Match(const CNetAddr &addr) const
1024  {
1025      if (!valid || !addr.IsValid() || network.m_net != addr.m_net)
1026          return false;
1027  
1028      switch (network.m_net) {
1029      case NET_IPV4:
1030      case NET_IPV6:
1031          break;
1032      case NET_ONION:
1033      case NET_I2P:
1034      case NET_CJDNS:
1035      case NET_INTERNAL:
1036          return addr == network;
1037      case NET_UNROUTABLE:
1038      case NET_MAX:
1039          return false;
1040      }
1041  
1042      assert(network.m_addr.size() == addr.m_addr.size());
1043      for (size_t x = 0; x < addr.m_addr.size(); ++x) {
1044          if ((addr.m_addr[x] & netmask[x]) != network.m_addr[x]) {
1045              return false;
1046          }
1047      }
1048      return true;
1049  }
1050  
1051  std::string CSubNet::ToString() const
1052  {
1053      std::string suffix;
1054  
1055      switch (network.m_net) {
1056      case NET_IPV4:
1057      case NET_IPV6: {
1058          assert(network.m_addr.size() <= sizeof(netmask));
1059  
1060          uint8_t cidr = 0;
1061  
1062          for (size_t i = 0; i < network.m_addr.size(); ++i) {
1063              if (netmask[i] == 0x00) {
1064                  break;
1065              }
1066              cidr += NetmaskBits(netmask[i]);
1067          }
1068  
1069          suffix = strprintf("/%u", cidr);
1070          break;
1071      }
1072      case NET_ONION:
1073      case NET_I2P:
1074      case NET_CJDNS:
1075      case NET_INTERNAL:
1076      case NET_UNROUTABLE:
1077      case NET_MAX:
1078          break;
1079      }
1080  
1081      return network.ToStringAddr() + suffix;
1082  }
1083  
1084  bool CSubNet::IsValid() const
1085  {
1086      return valid;
1087  }
1088  
1089  bool operator==(const CSubNet& a, const CSubNet& b)
1090  {
1091      return a.valid == b.valid && a.network == b.network && !memcmp(a.netmask, b.netmask, 16);
1092  }
1093  
1094  bool operator<(const CSubNet& a, const CSubNet& b)
1095  {
1096      return (a.network < b.network || (a.network == b.network && memcmp(a.netmask, b.netmask, 16) < 0));
1097  }