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1 : : // Copyright (c) 2021-2022 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 : : #include <netgroup.h>
6 : :
7 : : #include <hash.h>
8 : : #include <logging.h>
9 : : #include <util/asmap.h>
10 : :
11 : 0 : uint256 NetGroupManager::GetAsmapChecksum() const
12 : : {
13 [ # # ]: 0 : if (!m_asmap.size()) return {};
14 : :
15 : 0 : return (HashWriter{} << m_asmap).GetHash();
16 : : }
17 : :
18 : 0 : std::vector<unsigned char> NetGroupManager::GetGroup(const CNetAddr& address) const
19 : : {
20 : 0 : std::vector<unsigned char> vchRet;
21 : : // If non-empty asmap is supplied and the address is IPv4/IPv6,
22 : : // return ASN to be used for bucketing.
23 [ # # ]: 0 : uint32_t asn = GetMappedAS(address);
24 [ # # ]: 0 : if (asn != 0) { // Either asmap was empty, or address has non-asmappable net class (e.g. TOR).
25 [ # # ]: 0 : vchRet.push_back(NET_IPV6); // IPv4 and IPv6 with same ASN should be in the same bucket
26 [ # # ]: 0 : for (int i = 0; i < 4; i++) {
27 [ # # ]: 0 : vchRet.push_back((asn >> (8 * i)) & 0xFF);
28 : : }
29 : : return vchRet;
30 : : }
31 : :
32 [ # # # # ]: 0 : vchRet.push_back(address.GetNetClass());
33 : 0 : int nStartByte{0};
34 : 0 : int nBits{0};
35 : :
36 [ # # # # ]: 0 : if (address.IsLocal()) {
37 : : // all local addresses belong to the same group
38 [ # # # # ]: 0 : } else if (address.IsInternal()) {
39 : : // All internal-usage addresses get their own group.
40 : : // Skip over the INTERNAL_IN_IPV6_PREFIX returned by CAddress::GetAddrBytes().
41 : : nStartByte = INTERNAL_IN_IPV6_PREFIX.size();
42 : : nBits = ADDR_INTERNAL_SIZE * 8;
43 [ # # # # ]: 0 : } else if (!address.IsRoutable()) {
44 : : // all other unroutable addresses belong to the same group
45 [ # # # # ]: 0 : } else if (address.HasLinkedIPv4()) {
46 : : // IPv4 addresses (and mapped IPv4 addresses) use /16 groups
47 [ # # ]: 0 : uint32_t ipv4 = address.GetLinkedIPv4();
48 [ # # ]: 0 : vchRet.push_back((ipv4 >> 24) & 0xFF);
49 [ # # ]: 0 : vchRet.push_back((ipv4 >> 16) & 0xFF);
50 : : return vchRet;
51 [ # # # ]: 0 : } else if (address.IsTor() || address.IsI2P()) {
52 : : nBits = 4;
53 : : } else if (address.IsCJDNS()) {
54 : : // Treat in the same way as Tor and I2P because the address in all of
55 : : // them is "random" bytes (derived from a public key). However in CJDNS
56 : : // the first byte is a constant (see CJDNS_PREFIX), so the random bytes
57 : : // come after it. Thus skip the constant 8 bits at the start.
58 : : nBits = 12;
59 [ # # # # ]: 0 : } else if (address.IsHeNet()) {
60 : : // for he.net, use /36 groups
61 : : nBits = 36;
62 : : } else {
63 : : // for the rest of the IPv6 network, use /32 groups
64 : 0 : nBits = 32;
65 : : }
66 : :
67 : : // Push our address onto vchRet.
68 [ # # ]: 0 : auto addr_bytes = address.GetAddrBytes();
69 : 0 : const size_t num_bytes = nBits / 8;
70 [ # # ]: 0 : vchRet.insert(vchRet.end(), addr_bytes.begin() + nStartByte, addr_bytes.begin() + nStartByte + num_bytes);
71 : 0 : nBits %= 8;
72 : : // ...for the last byte, push nBits and for the rest of the byte push 1's
73 [ # # ]: 0 : if (nBits > 0) {
74 [ # # ]: 0 : assert(num_bytes < addr_bytes.size());
75 [ # # ]: 0 : vchRet.push_back(addr_bytes[num_bytes + nStartByte] | ((1 << (8 - nBits)) - 1));
76 : : }
77 : :
78 : 0 : return vchRet;
79 : 0 : }
80 : :
81 : 0 : uint32_t NetGroupManager::GetMappedAS(const CNetAddr& address) const
82 : : {
83 : 0 : uint32_t net_class = address.GetNetClass();
84 [ # # # # ]: 0 : if (m_asmap.size() == 0 || (net_class != NET_IPV4 && net_class != NET_IPV6)) {
85 : : return 0; // Indicates not found, safe because AS0 is reserved per RFC7607.
86 : : }
87 [ # # ]: 0 : std::vector<bool> ip_bits(128);
88 [ # # # # ]: 0 : if (address.HasLinkedIPv4()) {
89 : : // For lookup, treat as if it was just an IPv4 address (IPV4_IN_IPV6_PREFIX + IPv4 bits)
90 [ # # ]: 0 : for (int8_t byte_i = 0; byte_i < 12; ++byte_i) {
91 [ # # ]: 0 : for (uint8_t bit_i = 0; bit_i < 8; ++bit_i) {
92 : 0 : ip_bits[byte_i * 8 + bit_i] = (IPV4_IN_IPV6_PREFIX[byte_i] >> (7 - bit_i)) & 1;
93 : : }
94 : : }
95 [ # # ]: 0 : uint32_t ipv4 = address.GetLinkedIPv4();
96 [ # # ]: 0 : for (int i = 0; i < 32; ++i) {
97 : 0 : ip_bits[96 + i] = (ipv4 >> (31 - i)) & 1;
98 : : }
99 : : } else {
100 : : // Use all 128 bits of the IPv6 address otherwise
101 [ # # ]: 0 : assert(address.IsIPv6());
102 [ # # ]: 0 : auto addr_bytes = address.GetAddrBytes();
103 [ # # ]: 0 : for (int8_t byte_i = 0; byte_i < 16; ++byte_i) {
104 : 0 : uint8_t cur_byte = addr_bytes[byte_i];
105 [ # # ]: 0 : for (uint8_t bit_i = 0; bit_i < 8; ++bit_i) {
106 : 0 : ip_bits[byte_i * 8 + bit_i] = (cur_byte >> (7 - bit_i)) & 1;
107 : : }
108 : : }
109 : 0 : }
110 [ # # ]: 0 : uint32_t mapped_as = Interpret(m_asmap, ip_bits);
111 : 0 : return mapped_as;
112 : 0 : }
113 : :
114 : 0 : void NetGroupManager::ASMapHealthCheck(const std::vector<CNetAddr>& clearnet_addrs) const {
115 : 0 : std::set<uint32_t> clearnet_asns{};
116 : 0 : int unmapped_count{0};
117 : :
118 [ # # ]: 0 : for (const auto& addr : clearnet_addrs) {
119 [ # # ]: 0 : uint32_t asn = GetMappedAS(addr);
120 [ # # ]: 0 : if (asn == 0) {
121 : 0 : ++unmapped_count;
122 : 0 : continue;
123 : : }
124 [ # # ]: 0 : clearnet_asns.insert(asn);
125 : : }
126 : :
127 [ # # ]: 0 : LogPrintf("ASMap Health Check: %i clearnet peers are mapped to %i ASNs with %i peers being unmapped\n", clearnet_addrs.size(), clearnet_asns.size(), unmapped_count);
128 : 0 : }
129 : :
130 : 0 : bool NetGroupManager::UsingASMap() const {
131 : 0 : return m_asmap.size() > 0;
132 : : }
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