// Copyright (c) 2009-2010 Satoshi Nakamoto // Copyright (c) 2009-2018 The Bitcoin Core developers // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. #include #include #include #include static const unsigned char pchIPv4[12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff }; static const unsigned char pchOnionCat[] = {0xFD,0x87,0xD8,0x7E,0xEB,0x43}; // 0xFD + sha256("bitcoin")[0:5] static const unsigned char g_internal_prefix[] = { 0xFD, 0x6B, 0x88, 0xC0, 0x87, 0x24 }; /** * Construct an unspecified IPv6 network address (::/128). * * @note This address is considered invalid by CNetAddr::IsValid() */ CNetAddr::CNetAddr() { memset(ip, 0, sizeof(ip)); } void CNetAddr::SetIP(const CNetAddr& ipIn) { memcpy(ip, ipIn.ip, sizeof(ip)); } void CNetAddr::SetRaw(Network network, const uint8_t *ip_in) { switch(network) { case NET_IPV4: memcpy(ip, pchIPv4, 12); memcpy(ip+12, ip_in, 4); break; case NET_IPV6: memcpy(ip, ip_in, 16); break; default: assert(!"invalid network"); } } /** * Try to make this a dummy address that maps the specified name into IPv6 like * so: (0xFD + %sha256("bitcoin")[0:5]) + %sha256(name)[0:10]. Such dummy * addresses have a prefix of fd6b:88c0:8724::/48 and are guaranteed to not be * publicly routable as it falls under RFC4193's fc00::/7 subnet allocated to * unique-local addresses. * * CAddrMan uses these fake addresses to keep track of which DNS seeds were * used. * * @returns Whether or not the operation was successful. * * @see CNetAddr::IsInternal(), CNetAddr::IsRFC4193() */ bool CNetAddr::SetInternal(const std::string &name) { if (name.empty()) { return false; } unsigned char hash[32] = {}; CSHA256().Write((const unsigned char*)name.data(), name.size()).Finalize(hash); memcpy(ip, g_internal_prefix, sizeof(g_internal_prefix)); memcpy(ip + sizeof(g_internal_prefix), hash, sizeof(ip) - sizeof(g_internal_prefix)); return true; } /** * Try to make this a dummy address that maps the specified onion address into * IPv6 using OnionCat's range and encoding. Such dummy addresses have a prefix * of fd87:d87e:eb43::/48 and are guaranteed to not be publicly routable as they * fall under RFC4193's fc00::/7 subnet allocated to unique-local addresses. * * @returns Whether or not the operation was successful. * * @see CNetAddr::IsTor(), CNetAddr::IsRFC4193() */ bool CNetAddr::SetSpecial(const std::string &strName) { if (strName.size()>6 && strName.substr(strName.size() - 6, 6) == ".onion") { std::vector vchAddr = DecodeBase32(strName.substr(0, strName.size() - 6).c_str()); if (vchAddr.size() != 16-sizeof(pchOnionCat)) return false; memcpy(ip, pchOnionCat, sizeof(pchOnionCat)); for (unsigned int i=0; i<16-sizeof(pchOnionCat); i++) ip[i + sizeof(pchOnionCat)] = vchAddr[i]; return true; } return false; } CNetAddr::CNetAddr(const struct in_addr& ipv4Addr) { SetRaw(NET_IPV4, (const uint8_t*)&ipv4Addr); } CNetAddr::CNetAddr(const struct in6_addr& ipv6Addr, const uint32_t scope) { SetRaw(NET_IPV6, (const uint8_t*)&ipv6Addr); scopeId = scope; } unsigned int CNetAddr::GetByte(int n) const { return ip[15-n]; } bool CNetAddr::IsBindAny() const { const int cmplen = IsIPv4() ? 4 : 16; for (int i = 0; i < cmplen; ++i) { if (GetByte(i)) return false; } return true; } bool CNetAddr::IsIPv4() const { return (memcmp(ip, pchIPv4, sizeof(pchIPv4)) == 0); } bool CNetAddr::IsIPv6() const { return (!IsIPv4() && !IsTor() && !IsInternal()); } bool CNetAddr::IsRFC1918() const { return IsIPv4() && ( GetByte(3) == 10 || (GetByte(3) == 192 && GetByte(2) == 168) || (GetByte(3) == 172 && (GetByte(2) >= 16 && GetByte(2) <= 31))); } bool CNetAddr::IsRFC2544() const { return IsIPv4() && GetByte(3) == 198 && (GetByte(2) == 18 || GetByte(2) == 19); } bool CNetAddr::IsRFC3927() const { return IsIPv4() && (GetByte(3) == 169 && GetByte(2) == 254); } bool CNetAddr::IsRFC6598() const { return IsIPv4() && GetByte(3) == 100 && GetByte(2) >= 64 && GetByte(2) <= 127; } bool CNetAddr::IsRFC5737() const { return IsIPv4() && ((GetByte(3) == 192 && GetByte(2) == 0 && GetByte(1) == 2) || (GetByte(3) == 198 && GetByte(2) == 51 && GetByte(1) == 100) || (GetByte(3) == 203 && GetByte(2) == 0 && GetByte(1) == 113)); } bool CNetAddr::IsRFC3849() const { return GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x0D && GetByte(12) == 0xB8; } bool CNetAddr::IsRFC3964() const { return (GetByte(15) == 0x20 && GetByte(14) == 0x02); } bool CNetAddr::IsRFC6052() const { static const unsigned char pchRFC6052[] = {0,0x64,0xFF,0x9B,0,0,0,0,0,0,0,0}; return (memcmp(ip, pchRFC6052, sizeof(pchRFC6052)) == 0); } bool CNetAddr::IsRFC4380() const { return (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0 && GetByte(12) == 0); } bool CNetAddr::IsRFC4862() const { static const unsigned char pchRFC4862[] = {0xFE,0x80,0,0,0,0,0,0}; return (memcmp(ip, pchRFC4862, sizeof(pchRFC4862)) == 0); } bool CNetAddr::IsRFC4193() const { return ((GetByte(15) & 0xFE) == 0xFC); } bool CNetAddr::IsRFC6145() const { static const unsigned char pchRFC6145[] = {0,0,0,0,0,0,0,0,0xFF,0xFF,0,0}; return (memcmp(ip, pchRFC6145, sizeof(pchRFC6145)) == 0); } bool CNetAddr::IsRFC4843() const { return (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x00 && (GetByte(12) & 0xF0) == 0x10); } /** * @returns Whether or not this is a dummy address that maps an onion address * into IPv6. * * @see CNetAddr::SetSpecial(const std::string &) */ bool CNetAddr::IsTor() const { return (memcmp(ip, pchOnionCat, sizeof(pchOnionCat)) == 0); } bool CNetAddr::IsLocal() const { // IPv4 loopback (127.0.0.0/8 or 0.0.0.0/8) if (IsIPv4() && (GetByte(3) == 127 || GetByte(3) == 0)) return true; // IPv6 loopback (::1/128) static const unsigned char pchLocal[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1}; if (memcmp(ip, pchLocal, 16) == 0) return true; return false; } /** * @returns Whether or not this network address is a valid address that @a could * be used to refer to an actual host. * * @note A valid address may or may not be publicly routable on the global * internet. As in, the set of valid addreses is a superset of the set of * publicly routable addresses. * * @see CNetAddr::IsRoutable() */ bool CNetAddr::IsValid() const { // Cleanup 3-byte shifted addresses caused by garbage in size field // of addr messages from versions before 0.2.9 checksum. // Two consecutive addr messages look like this: // header20 vectorlen3 addr26 addr26 addr26 header20 vectorlen3 addr26 addr26 addr26... // so if the first length field is garbled, it reads the second batch // of addr misaligned by 3 bytes. if (memcmp(ip, pchIPv4+3, sizeof(pchIPv4)-3) == 0) return false; // unspecified IPv6 address (::/128) unsigned char ipNone6[16] = {}; if (memcmp(ip, ipNone6, 16) == 0) return false; // documentation IPv6 address if (IsRFC3849()) return false; if (IsInternal()) return false; if (IsIPv4()) { // INADDR_NONE uint32_t ipNone = INADDR_NONE; if (memcmp(ip+12, &ipNone, 4) == 0) return false; // 0 ipNone = 0; if (memcmp(ip+12, &ipNone, 4) == 0) return false; } return true; } /** * @returns Whether or not this network address is publicly routable on the * global internet. * * @note A routable address is always valid. As in, the set of routable addreses * is a subset of the set of valid addresses. * * @see CNetAddr::IsValid() */ bool CNetAddr::IsRoutable() const { return IsValid() && !(IsRFC1918() || IsRFC2544() || IsRFC3927() || IsRFC4862() || IsRFC6598() || IsRFC5737() || (IsRFC4193() && !IsTor()) || IsRFC4843() || IsLocal() || IsInternal()); } /** * @returns Whether or not this is a dummy address that maps a name into IPv6. * * @see CNetAddr::SetInternal(const std::string &) */ bool CNetAddr::IsInternal() const { return memcmp(ip, g_internal_prefix, sizeof(g_internal_prefix)) == 0; } enum Network CNetAddr::GetNetwork() const { if (IsInternal()) return NET_INTERNAL; if (!IsRoutable()) return NET_UNROUTABLE; if (IsIPv4()) return NET_IPV4; if (IsTor()) return NET_ONION; return NET_IPV6; } std::string CNetAddr::ToStringIP() const { if (IsTor()) return EncodeBase32(&ip[6], 10) + ".onion"; if (IsInternal()) return EncodeBase32(ip + sizeof(g_internal_prefix), sizeof(ip) - sizeof(g_internal_prefix)) + ".internal"; CService serv(*this, 0); struct sockaddr_storage sockaddr; socklen_t socklen = sizeof(sockaddr); if (serv.GetSockAddr((struct sockaddr*)&sockaddr, &socklen)) { char name[1025] = ""; if (!getnameinfo((const struct sockaddr*)&sockaddr, socklen, name, sizeof(name), nullptr, 0, NI_NUMERICHOST)) return std::string(name); } if (IsIPv4()) return strprintf("%u.%u.%u.%u", GetByte(3), GetByte(2), GetByte(1), GetByte(0)); else return strprintf("%x:%x:%x:%x:%x:%x:%x:%x", GetByte(15) << 8 | GetByte(14), GetByte(13) << 8 | GetByte(12), GetByte(11) << 8 | GetByte(10), GetByte(9) << 8 | GetByte(8), GetByte(7) << 8 | GetByte(6), GetByte(5) << 8 | GetByte(4), GetByte(3) << 8 | GetByte(2), GetByte(1) << 8 | GetByte(0)); } std::string CNetAddr::ToString() const { return ToStringIP(); } bool operator==(const CNetAddr& a, const CNetAddr& b) { return (memcmp(a.ip, b.ip, 16) == 0); } bool operator<(const CNetAddr& a, const CNetAddr& b) { return (memcmp(a.ip, b.ip, 16) < 0); } /** * Try to get our IPv4 address. * * @param[out] pipv4Addr The in_addr struct to which to copy. * * @returns Whether or not the operation was successful, in particular, whether * or not our address was an IPv4 address. * * @see CNetAddr::IsIPv4() */ bool CNetAddr::GetInAddr(struct in_addr* pipv4Addr) const { if (!IsIPv4()) return false; memcpy(pipv4Addr, ip+12, 4); return true; } /** * Try to get our IPv6 address. * * @param[out] pipv6Addr The in6_addr struct to which to copy. * * @returns Whether or not the operation was successful, in particular, whether * or not our address was an IPv6 address. * * @see CNetAddr::IsIPv6() */ bool CNetAddr::GetIn6Addr(struct in6_addr* pipv6Addr) const { if (!IsIPv6()) { return false; } memcpy(pipv6Addr, ip, 16); return true; } /** * Get the canonical identifier of our network group * * The groups are assigned in a way where it should be costly for an attacker to * obtain addresses with many different group identifiers, even if it is cheap * to obtain addresses with the same identifier. * * @note No two connections will be attempted to addresses with the same network * group. */ std::vector CNetAddr::GetGroup() const { std::vector vchRet; int nClass = NET_IPV6; int nStartByte = 0; int nBits = 16; // all local addresses belong to the same group if (IsLocal()) { nClass = 255; nBits = 0; } // all internal-usage addresses get their own group if (IsInternal()) { nClass = NET_INTERNAL; nStartByte = sizeof(g_internal_prefix); nBits = (sizeof(ip) - sizeof(g_internal_prefix)) * 8; } // all other unroutable addresses belong to the same group else if (!IsRoutable()) { nClass = NET_UNROUTABLE; nBits = 0; } // for IPv4 addresses, '1' + the 16 higher-order bits of the IP // includes mapped IPv4, SIIT translated IPv4, and the well-known prefix else if (IsIPv4() || IsRFC6145() || IsRFC6052()) { nClass = NET_IPV4; nStartByte = 12; } // for 6to4 tunnelled addresses, use the encapsulated IPv4 address else if (IsRFC3964()) { nClass = NET_IPV4; nStartByte = 2; } // for Teredo-tunnelled IPv6 addresses, use the encapsulated IPv4 address else if (IsRFC4380()) { vchRet.push_back(NET_IPV4); vchRet.push_back(GetByte(3) ^ 0xFF); vchRet.push_back(GetByte(2) ^ 0xFF); return vchRet; } else if (IsTor()) { nClass = NET_ONION; nStartByte = 6; nBits = 4; } // for he.net, use /36 groups else if (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x04 && GetByte(12) == 0x70) nBits = 36; // for the rest of the IPv6 network, use /32 groups else nBits = 32; vchRet.push_back(nClass); // push our ip onto vchRet byte by byte... while (nBits >= 8) { vchRet.push_back(GetByte(15 - nStartByte)); nStartByte++; nBits -= 8; } // ...for the last byte, push nBits and for the rest of the byte push 1's if (nBits > 0) vchRet.push_back(GetByte(15 - nStartByte) | ((1 << (8 - nBits)) - 1)); return vchRet; } uint64_t CNetAddr::GetHash() const { uint256 hash = Hash(&ip[0], &ip[16]); uint64_t nRet; memcpy(&nRet, &hash, sizeof(nRet)); return nRet; } // private extensions to enum Network, only returned by GetExtNetwork, // and only used in GetReachabilityFrom static const int NET_UNKNOWN = NET_MAX + 0; static const int NET_TEREDO = NET_MAX + 1; int static GetExtNetwork(const CNetAddr *addr) { if (addr == nullptr) return NET_UNKNOWN; if (addr->IsRFC4380()) return NET_TEREDO; return addr->GetNetwork(); } /** Calculates a metric for how reachable (*this) is from a given partner */ int CNetAddr::GetReachabilityFrom(const CNetAddr *paddrPartner) const { enum Reachability { REACH_UNREACHABLE, REACH_DEFAULT, REACH_TEREDO, REACH_IPV6_WEAK, REACH_IPV4, REACH_IPV6_STRONG, REACH_PRIVATE }; if (!IsRoutable() || IsInternal()) return REACH_UNREACHABLE; int ourNet = GetExtNetwork(this); int theirNet = GetExtNetwork(paddrPartner); bool fTunnel = IsRFC3964() || IsRFC6052() || IsRFC6145(); switch(theirNet) { case NET_IPV4: switch(ourNet) { default: return REACH_DEFAULT; case NET_IPV4: return REACH_IPV4; } case NET_IPV6: switch(ourNet) { default: return REACH_DEFAULT; case NET_TEREDO: return REACH_TEREDO; case NET_IPV4: return REACH_IPV4; case NET_IPV6: return fTunnel ? REACH_IPV6_WEAK : REACH_IPV6_STRONG; // only prefer giving our IPv6 address if it's not tunnelled } case NET_ONION: switch(ourNet) { default: return REACH_DEFAULT; case NET_IPV4: return REACH_IPV4; // Tor users can connect to IPv4 as well case NET_ONION: return REACH_PRIVATE; } case NET_TEREDO: switch(ourNet) { default: return REACH_DEFAULT; case NET_TEREDO: return REACH_TEREDO; case NET_IPV6: return REACH_IPV6_WEAK; case NET_IPV4: return REACH_IPV4; } case NET_UNKNOWN: case NET_UNROUTABLE: default: switch(ourNet) { default: return REACH_DEFAULT; case NET_TEREDO: return REACH_TEREDO; case NET_IPV6: return REACH_IPV6_WEAK; case NET_IPV4: return REACH_IPV4; case NET_ONION: return REACH_PRIVATE; // either from Tor, or don't care about our address } } } CService::CService() : port(0) { } CService::CService(const CNetAddr& cip, unsigned short portIn) : CNetAddr(cip), port(portIn) { } CService::CService(const struct in_addr& ipv4Addr, unsigned short portIn) : CNetAddr(ipv4Addr), port(portIn) { } CService::CService(const struct in6_addr& ipv6Addr, unsigned short portIn) : CNetAddr(ipv6Addr), port(portIn) { } CService::CService(const struct sockaddr_in& addr) : CNetAddr(addr.sin_addr), port(ntohs(addr.sin_port)) { assert(addr.sin_family == AF_INET); } CService::CService(const struct sockaddr_in6 &addr) : CNetAddr(addr.sin6_addr, addr.sin6_scope_id), port(ntohs(addr.sin6_port)) { assert(addr.sin6_family == AF_INET6); } bool CService::SetSockAddr(const struct sockaddr *paddr) { switch (paddr->sa_family) { case AF_INET: *this = CService(*(const struct sockaddr_in*)paddr); return true; case AF_INET6: *this = CService(*(const struct sockaddr_in6*)paddr); return true; default: return false; } } unsigned short CService::GetPort() const { return port; } bool operator==(const CService& a, const CService& b) { return static_cast(a) == static_cast(b) && a.port == b.port; } bool operator<(const CService& a, const CService& b) { return static_cast(a) < static_cast(b) || (static_cast(a) == static_cast(b) && a.port < b.port); } /** * Obtain the IPv4/6 socket address this represents. * * @param[out] paddr The obtained socket address. * @param[in,out] addrlen The size, in bytes, of the address structure pointed * to by paddr. The value that's pointed to by this * parameter might change after calling this function if * the size of the corresponding address structure * changed. * * @returns Whether or not the operation was successful. */ bool CService::GetSockAddr(struct sockaddr* paddr, socklen_t *addrlen) const { if (IsIPv4()) { if (*addrlen < (socklen_t)sizeof(struct sockaddr_in)) return false; *addrlen = sizeof(struct sockaddr_in); struct sockaddr_in *paddrin = (struct sockaddr_in*)paddr; memset(paddrin, 0, *addrlen); if (!GetInAddr(&paddrin->sin_addr)) return false; paddrin->sin_family = AF_INET; paddrin->sin_port = htons(port); return true; } if (IsIPv6()) { if (*addrlen < (socklen_t)sizeof(struct sockaddr_in6)) return false; *addrlen = sizeof(struct sockaddr_in6); struct sockaddr_in6 *paddrin6 = (struct sockaddr_in6*)paddr; memset(paddrin6, 0, *addrlen); if (!GetIn6Addr(&paddrin6->sin6_addr)) return false; paddrin6->sin6_scope_id = scopeId; paddrin6->sin6_family = AF_INET6; paddrin6->sin6_port = htons(port); return true; } return false; } /** * @returns An identifier unique to this service's address and port number. */ std::vector CService::GetKey() const { std::vector vKey; vKey.resize(18); memcpy(vKey.data(), ip, 16); vKey[16] = port / 0x100; // most significant byte of our port vKey[17] = port & 0x0FF; // least significant byte of our port return vKey; } std::string CService::ToStringPort() const { return strprintf("%u", port); } std::string CService::ToStringIPPort() const { if (IsIPv4() || IsTor() || IsInternal()) { return ToStringIP() + ":" + ToStringPort(); } else { return "[" + ToStringIP() + "]:" + ToStringPort(); } } std::string CService::ToString() const { return ToStringIPPort(); } CSubNet::CSubNet(): valid(false) { memset(netmask, 0, sizeof(netmask)); } CSubNet::CSubNet(const CNetAddr &addr, int32_t mask) { valid = true; network = addr; // Default to /32 (IPv4) or /128 (IPv6), i.e. match single address memset(netmask, 255, sizeof(netmask)); // IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n const int astartofs = network.IsIPv4() ? 12 : 0; int32_t n = mask; if(n >= 0 && n <= (128 - astartofs*8)) // Only valid if in range of bits of address { n += astartofs*8; // Clear bits [n..127] for (; n < 128; ++n) netmask[n>>3] &= ~(1<<(7-(n&7))); } else valid = false; // Normalize network according to netmask for(int x=0; x<16; ++x) network.ip[x] &= netmask[x]; } CSubNet::CSubNet(const CNetAddr &addr, const CNetAddr &mask) { valid = true; network = addr; // Default to /32 (IPv4) or /128 (IPv6), i.e. match single address memset(netmask, 255, sizeof(netmask)); // IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n const int astartofs = network.IsIPv4() ? 12 : 0; for(int x=astartofs; x<16; ++x) netmask[x] = mask.ip[x]; // Normalize network according to netmask for(int x=0; x<16; ++x) network.ip[x] &= netmask[x]; } CSubNet::CSubNet(const CNetAddr &addr): valid(addr.IsValid()) { memset(netmask, 255, sizeof(netmask)); network = addr; } /** * @returns True if this subnet is valid, the specified address is valid, and * the specified address belongs in this subnet. */ bool CSubNet::Match(const CNetAddr &addr) const { if (!valid || !addr.IsValid()) return false; for(int x=0; x<16; ++x) if ((addr.ip[x] & netmask[x]) != network.ip[x]) return false; return true; } /** * @returns The number of 1-bits in the prefix of the specified subnet mask. If * the specified subnet mask is not a valid one, -1. */ static inline int NetmaskBits(uint8_t x) { switch(x) { case 0x00: return 0; case 0x80: return 1; case 0xc0: return 2; case 0xe0: return 3; case 0xf0: return 4; case 0xf8: return 5; case 0xfc: return 6; case 0xfe: return 7; case 0xff: return 8; default: return -1; } } std::string CSubNet::ToString() const { /* Parse binary 1{n}0{N-n} to see if mask can be represented as /n */ int cidr = 0; bool valid_cidr = true; int n = network.IsIPv4() ? 12 : 0; for (; n < 16 && netmask[n] == 0xff; ++n) cidr += 8; if (n < 16) { int bits = NetmaskBits(netmask[n]); if (bits < 0) valid_cidr = false; else cidr += bits; ++n; } for (; n < 16 && valid_cidr; ++n) if (netmask[n] != 0x00) valid_cidr = false; /* Format output */ std::string strNetmask; if (valid_cidr) { strNetmask = strprintf("%u", cidr); } else { if (network.IsIPv4()) strNetmask = strprintf("%u.%u.%u.%u", netmask[12], netmask[13], netmask[14], netmask[15]); else strNetmask = strprintf("%x:%x:%x:%x:%x:%x:%x:%x", netmask[0] << 8 | netmask[1], netmask[2] << 8 | netmask[3], netmask[4] << 8 | netmask[5], netmask[6] << 8 | netmask[7], netmask[8] << 8 | netmask[9], netmask[10] << 8 | netmask[11], netmask[12] << 8 | netmask[13], netmask[14] << 8 | netmask[15]); } return network.ToString() + "/" + strNetmask; } bool CSubNet::IsValid() const { return valid; } bool operator==(const CSubNet& a, const CSubNet& b) { return a.valid == b.valid && a.network == b.network && !memcmp(a.netmask, b.netmask, 16); } bool operator<(const CSubNet& a, const CSubNet& b) { return (a.network < b.network || (a.network == b.network && memcmp(a.netmask, b.netmask, 16) < 0)); }