/workdir/bitcoin/src/netgroup.h
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1 | | // Copyright (c) 2021 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_NETGROUP_H |
6 | | #define BITCOIN_NETGROUP_H |
7 | | |
8 | | #include <netaddress.h> |
9 | | #include <uint256.h> |
10 | | |
11 | | #include <vector> |
12 | | |
13 | | /** |
14 | | * Netgroup manager |
15 | | */ |
16 | | class NetGroupManager { |
17 | | public: |
18 | | explicit NetGroupManager(std::vector<bool> asmap) |
19 | 0 | : m_asmap{std::move(asmap)} |
20 | 0 | {} |
21 | | |
22 | | /** Get a checksum identifying the asmap being used. */ |
23 | | uint256 GetAsmapChecksum() const; |
24 | | |
25 | | /** |
26 | | * Get the canonical identifier of the network group for address. |
27 | | * |
28 | | * The groups are assigned in a way where it should be costly for an attacker to |
29 | | * obtain addresses with many different group identifiers, even if it is cheap |
30 | | * to obtain addresses with the same identifier. |
31 | | * |
32 | | * @note No two connections will be attempted to addresses with the same network |
33 | | * group. |
34 | | */ |
35 | | std::vector<unsigned char> GetGroup(const CNetAddr& address) const; |
36 | | |
37 | | /** |
38 | | * Get the autonomous system on the BGP path to address. |
39 | | * |
40 | | * The ip->AS mapping depends on how asmap is constructed. |
41 | | */ |
42 | | uint32_t GetMappedAS(const CNetAddr& address) const; |
43 | | |
44 | | /** |
45 | | * Analyze and log current health of ASMap based buckets. |
46 | | */ |
47 | | void ASMapHealthCheck(const std::vector<CNetAddr>& clearnet_addrs) const; |
48 | | |
49 | | /** |
50 | | * Indicates whether ASMap is being used for clearnet bucketing. |
51 | | */ |
52 | | bool UsingASMap() const; |
53 | | |
54 | | private: |
55 | | /** Compressed IP->ASN mapping, loaded from a file when a node starts. |
56 | | * |
57 | | * This mapping is then used for bucketing nodes in Addrman and for |
58 | | * ensuring we connect to a diverse set of peers in Connman. The map is |
59 | | * empty if no file was provided. |
60 | | * |
61 | | * If asmap is provided, nodes will be bucketed by AS they belong to, in |
62 | | * order to make impossible for a node to connect to several nodes hosted |
63 | | * in a single AS. This is done in response to Erebus attack, but also to |
64 | | * generally diversify the connections every node creates, especially |
65 | | * useful when a large fraction of nodes operate under a couple of cloud |
66 | | * providers. |
67 | | * |
68 | | * If a new asmap is provided, the existing addrman records are |
69 | | * re-bucketed. |
70 | | * |
71 | | * This is initialized in the constructor, const, and therefore is |
72 | | * thread-safe. */ |
73 | | const std::vector<bool> m_asmap; |
74 | | }; |
75 | | |
76 | | #endif // BITCOIN_NETGROUP_H |