Bitcoin Core  22.99.0
P2P Digital Currency
banman.h
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1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2020 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 #ifndef BITCOIN_BANMAN_H
6 #define BITCOIN_BANMAN_H
7 
8 #include <addrdb.h>
9 #include <bloom.h>
10 #include <fs.h>
11 #include <net_types.h> // For banmap_t
12 #include <sync.h>
13 
14 #include <chrono>
15 #include <cstdint>
16 #include <memory>
17 
18 // NOTE: When adjusting this, update rpcnet:setban's help ("24h")
19 static constexpr unsigned int DEFAULT_MISBEHAVING_BANTIME = 60 * 60 * 24; // Default 24-hour ban
20 
22 static constexpr std::chrono::minutes DUMP_BANS_INTERVAL{15};
23 
24 class CClientUIInterface;
25 class CNetAddr;
26 class CSubNet;
27 
28 // Banman manages two related but distinct concepts:
29 //
30 // 1. Banning. This is configured manually by the user, through the setban RPC.
31 // If an address or subnet is banned, we never accept incoming connections from
32 // it and never create outgoing connections to it. We won't gossip its address
33 // to other peers in addr messages. Banned addresses and subnets are stored to
34 // disk on shutdown and reloaded on startup. Banning can be used to
35 // prevent connections with spy nodes or other griefers.
36 //
37 // 2. Discouragement. If a peer misbehaves enough (see Misbehaving() in
38 // net_processing.cpp), we'll mark that address as discouraged. We still allow
39 // incoming connections from them, but they're preferred for eviction when
40 // we receive new incoming connections. We never make outgoing connections to
41 // them, and do not gossip their address to other peers. This is implemented as
42 // a bloom filter. We can (probabilistically) test for membership, but can't
43 // list all discouraged addresses or unmark them as discouraged. Discouragement
44 // can prevent our limited connection slots being used up by incompatible
45 // or broken peers.
46 //
47 // Neither banning nor discouragement are protections against denial-of-service
48 // attacks, since if an attacker has a way to waste our resources and we
49 // disconnect from them and ban that address, it's trivial for them to
50 // reconnect from another IP address.
51 //
52 // Attempting to automatically disconnect or ban any class of peer carries the
53 // risk of splitting the network. For example, if we banned/disconnected for a
54 // transaction that fails a policy check and a future version changes the
55 // policy check so the transaction is accepted, then that transaction could
56 // cause the network to split between old nodes and new nodes.
57 
58 class BanMan
59 {
60 public:
61  ~BanMan();
62  BanMan(fs::path ban_file, CClientUIInterface* client_interface, int64_t default_ban_time);
63  void Ban(const CNetAddr& net_addr, int64_t ban_time_offset = 0, bool since_unix_epoch = false);
64  void Ban(const CSubNet& sub_net, int64_t ban_time_offset = 0, bool since_unix_epoch = false);
65  void Discourage(const CNetAddr& net_addr);
66  void ClearBanned();
67 
69  bool IsBanned(const CNetAddr& net_addr);
70 
72  bool IsBanned(const CSubNet& sub_net);
73 
75  bool IsDiscouraged(const CNetAddr& net_addr);
76 
77  bool Unban(const CNetAddr& net_addr);
78  bool Unban(const CSubNet& sub_net);
79  void GetBanned(banmap_t& banmap);
80  void DumpBanlist();
81 
82 private:
83  bool BannedSetIsDirty();
85  void SetBannedSetDirty(bool dirty = true);
87  void SweepBanned();
88 
91  bool m_is_dirty GUARDED_BY(m_cs_banned){false};
94  const int64_t m_default_ban_time;
95  CRollingBloomFilter m_discouraged GUARDED_BY(m_cs_banned) {50000, 0.000001};
96 };
97 
98 #endif
BanMan::IsBanned
bool IsBanned(const CNetAddr &net_addr)
Return whether net_addr is banned.
Definition: banman.cpp:75
BanMan::ClearBanned
void ClearBanned()
Definition: banman.cpp:58
BanMan::IsDiscouraged
bool IsDiscouraged(const CNetAddr &net_addr)
Return whether net_addr is discouraged.
Definition: banman.cpp:69
CClientUIInterface
Signals for UI communication.
Definition: ui_interface.h:24
fs.h
sync.h
BanMan::Unban
bool Unban(const CNetAddr &net_addr)
Definition: banman.cpp:142
CNetAddr
Network address.
Definition: netaddress.h:118
BanMan::m_ban_db
CBanDB m_ban_db
Definition: banman.h:93
AnnotatedMixin< std::recursive_mutex >
BanMan::m_client_interface
CClientUIInterface * m_client_interface
Definition: banman.h:92
BanMan::DumpBanlist
void DumpBanlist()
Definition: banman.cpp:40
bloom.h
addrdb.h
net_types.h
fs::path
Path class wrapper to prepare application code for transition from boost::filesystem library to std::...
Definition: fs.h:33
BanMan::BanMan
BanMan(fs::path ban_file, CClientUIInterface *client_interface, int64_t default_ban_time)
Definition: banman.cpp:15
CSubNet
Definition: netaddress.h:486
BanMan::GetBanned
void GetBanned(banmap_t &banmap)
Definition: banman.cpp:160
DUMP_BANS_INTERVAL
static constexpr std::chrono::minutes DUMP_BANS_INTERVAL
How often to dump banned addresses/subnets to disk.
Definition: banman.h:22
BanMan::m_cs_banned
RecursiveMutex m_cs_banned
Definition: banman.h:89
BanMan::SweepBanned
void SweepBanned()
clean unused entries (if bantime has expired)
Definition: banman.cpp:168
CBanDB
Access to the banlist database (banlist.json)
Definition: addrdb.h:27
BanMan::SetBannedSetDirty
void SetBannedSetDirty(bool dirty=true)
set the "dirty" flag for the banlist
Definition: banman.cpp:199
BanMan::m_default_ban_time
const int64_t m_default_ban_time
Definition: banman.h:94
BanMan
Definition: banman.h:58
BanMan::Ban
void Ban(const CNetAddr &net_addr, int64_t ban_time_offset=0, bool since_unix_epoch=false)
Definition: banman.cpp:104
DEFAULT_MISBEHAVING_BANTIME
static constexpr unsigned int DEFAULT_MISBEHAVING_BANTIME
Definition: banman.h:19
BanMan::~BanMan
~BanMan()
Definition: banman.cpp:35
BanMan::GUARDED_BY
bool m_is_dirty GUARDED_BY(m_cs_banned)
Definition: banman.h:91
banmap_t
std::map< CSubNet, CBanEntry > banmap_t
Definition: net_types.h:41
BanMan::GUARDED_BY
banmap_t m_banned GUARDED_BY(m_cs_banned)
BanMan::Discourage
void Discourage(const CNetAddr &net_addr)
Definition: banman.cpp:110
CRollingBloomFilter
RollingBloomFilter is a probabilistic "keep track of most recently inserted" set.
Definition: bloom.h:108
BanMan::GUARDED_BY
CRollingBloomFilter m_discouraged GUARDED_BY(m_cs_banned)
Definition: banman.h:95
BanMan::BannedSetIsDirty
bool BannedSetIsDirty()
Definition: banman.cpp:193