diff options
author | Pieter Wuille <pieter.wuille@gmail.com> | 2020-01-29 15:02:26 -0800 |
---|---|---|
committer | Pieter Wuille <pieter.wuille@gmail.com> | 2020-01-31 14:51:37 -0800 |
commit | 38c2395d7a905c87dc4630031849fd8e403e61bf (patch) | |
tree | f180aea5ac3ce5a4bdf6722a0e5e94878de5f84d | |
parent | 6f8c93731203c111f86c39eaf2102f9a825d1706 (diff) |
Use ASNs for mapped IPv4 addresses correctly
-rw-r--r-- | src/netaddress.cpp | 97 | ||||
-rw-r--r-- | src/netaddress.h | 5 |
2 files changed, 61 insertions, 41 deletions
diff --git a/src/netaddress.cpp b/src/netaddress.cpp index ce3e17197e..1cac57a817 100644 --- a/src/netaddress.cpp +++ b/src/netaddress.cpp @@ -401,6 +401,26 @@ bool CNetAddr::GetIn6Addr(struct in6_addr* pipv6Addr) const return true; } +bool CNetAddr::HasLinkedIPv4() const +{ + return IsRoutable() && (IsIPv4() || IsRFC6145() || IsRFC6052() || IsRFC3964() || IsRFC4380()); +} + +uint32_t CNetAddr::GetLinkedIPv4() const +{ + if (IsIPv4() || IsRFC6145() || IsRFC6052()) { + // IPv4, mapped IPv4, SIIT translated IPv4: the IPv4 address is the last 4 bytes of the address + return ReadBE32(ip + 12); + } else if (IsRFC3964()) { + // 6to4 tunneled IPv4: the IPv4 address is in bytes 2-6 + return ReadBE32(ip + 2); + } else if (IsRFC4380()) { + // Teredo tunneled IPv4: the IPv4 address is in the last 4 bytes of the address, but bitflipped + return ~ReadBE32(ip + 12); + } + assert(false); +} + uint32_t CNetAddr::GetNetClass() const { uint32_t net_class = NET_IPV6; if (IsLocal()) { @@ -410,7 +430,7 @@ uint32_t CNetAddr::GetNetClass() const { net_class = NET_INTERNAL; } else if (!IsRoutable()) { net_class = NET_UNROUTABLE; - } else if (IsIPv4() || IsRFC6145() || IsRFC6052() || IsRFC3964() || IsRFC4380()) { + } else if (HasLinkedIPv4()) { net_class = NET_IPV4; } else if (IsTor()) { net_class = NET_ONION; @@ -424,10 +444,24 @@ uint32_t CNetAddr::GetMappedAS(const std::vector<bool> &asmap) const { return 0; // Indicates not found, safe because AS0 is reserved per RFC7607. } std::vector<bool> ip_bits(128); - for (int8_t byte_i = 0; byte_i < 16; ++byte_i) { - uint8_t cur_byte = GetByte(15 - byte_i); - for (uint8_t bit_i = 0; bit_i < 8; ++bit_i) { - ip_bits[byte_i * 8 + bit_i] = (cur_byte >> (7 - bit_i)) & 1; + if (HasLinkedIPv4()) { + // For lookup, treat as if it was just an IPv4 address (pchIPv4 prefix + IPv4 bits) + for (int8_t byte_i = 0; byte_i < 12; ++byte_i) { + for (uint8_t bit_i = 0; bit_i < 8; ++bit_i) { + ip_bits[byte_i * 8 + bit_i] = (pchIPv4[byte_i] >> (7 - bit_i)) & 1; + } + } + uint32_t ipv4 = GetLinkedIPv4(); + for (int i = 0; i < 32; ++i) { + ip_bits[96 + i] = (ipv4 >> (31 - i)) & 1; + } + } else { + // Use all 128 bits of the IPv6 address otherwise + for (int8_t byte_i = 0; byte_i < 16; ++byte_i) { + uint8_t cur_byte = GetByte(15 - byte_i); + for (uint8_t bit_i = 0; bit_i < 8; ++bit_i) { + ip_bits[byte_i * 8 + bit_i] = (cur_byte >> (7 - bit_i)) & 1; + } } } uint32_t mapped_as = Interpret(asmap, ip_bits); @@ -463,51 +497,32 @@ std::vector<unsigned char> CNetAddr::GetGroup(const std::vector<bool> &asmap) co int nStartByte = 0; int nBits = 16; - // all local addresses belong to the same group - if (IsLocal()) - { + if (IsLocal()) { + // all local addresses belong to the same group nBits = 0; - } - // all internal-usage addresses get their own group - if (IsInternal()) - { + } else if (IsInternal()) { + // all internal-usage addresses get their own group 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()) - { + } else if (!IsRoutable()) { + // all other unroutable addresses belong to the same group 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()) - { - nStartByte = 12; - } - // for 6to4 tunnelled addresses, use the encapsulated IPv4 address - else if (IsRFC3964()) - { - nStartByte = 2; - } - // for Teredo-tunnelled IPv6 addresses, use the encapsulated IPv4 address - else if (IsRFC4380()) - { - vchRet.push_back(GetByte(3) ^ 0xFF); - vchRet.push_back(GetByte(2) ^ 0xFF); + } else if (HasLinkedIPv4()) { + // IPv4 addresses (and mapped IPv4 addresses) use /16 groups + uint32_t ipv4 = GetLinkedIPv4(); + vchRet.push_back((ipv4 >> 24) & 0xFF); + vchRet.push_back((ipv4 >> 16) & 0xFF); return vchRet; - } - else if (IsTor()) - { + } else if (IsTor()) { nStartByte = 6; nBits = 4; - } - // for he.net, use /36 groups - else if (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x04 && GetByte(12) == 0x70) + } else if (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x04 && GetByte(12) == 0x70) { + // for he.net, use /36 groups nBits = 36; - // for the rest of the IPv6 network, use /32 groups - else + } else { + // for the rest of the IPv6 network, use /32 groups nBits = 32; + } // push our ip onto vchRet byte by byte... while (nBits >= 8) diff --git a/src/netaddress.h b/src/netaddress.h index 078234595c..1270e71606 100644 --- a/src/netaddress.h +++ b/src/netaddress.h @@ -80,6 +80,11 @@ class CNetAddr bool GetInAddr(struct in_addr* pipv4Addr) const; uint32_t 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; + //! Whether this address has a linked IPv4 address (see GetLinkedIPv4()). + bool HasLinkedIPv4() const; + // The AS on the BGP path to the node we use to diversify // peers in AddrMan bucketing based on the AS infrastructure. // The ip->AS mapping depends on how asmap is constructed. |