Initial Vexta Core v0.1.0 release

src/banman.h

@@ -0,0 +1,98 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2020 The DigiByte Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#ifndef DIGIBYTE_BANMAN_H
+#define DIGIBYTE_BANMAN_H
+
+#include <addrdb.h>
+#include <bloom.h>
+#include <fs.h>
+#include <net_types.h> // For banmap_t
+#include <sync.h>
+
+#include <chrono>
+#include <cstdint>
+#include <memory>
+
+// NOTE: When adjusting this, update rpcnet:setban's help ("24h")
+static constexpr unsigned int DEFAULT_MISBEHAVING_BANTIME = 60 * 60 * 24; // Default 24-hour ban
+
+/// How often to dump banned addresses/subnets to disk.
+static constexpr std::chrono::minutes DUMP_BANS_INTERVAL{15};
+
+class CClientUIInterface;
+class CNetAddr;
+class CSubNet;
+
+// Banman manages two related but distinct concepts:
+//
+// 1. Banning. This is configured manually by the user, through the setban RPC.
+// If an address or subnet is banned, we never accept incoming connections from
+// it and never create outgoing connections to it. We won't gossip its address
+// to other peers in addr messages. Banned addresses and subnets are stored to
+// disk on shutdown and reloaded on startup. Banning can be used to
+// prevent connections with spy nodes or other griefers.
+//
+// 2. Discouragement. If a peer misbehaves enough (see Misbehaving() in
+// net_processing.cpp), we'll mark that address as discouraged. We still allow
+// incoming connections from them, but they're preferred for eviction when
+// we receive new incoming connections. We never make outgoing connections to
+// them, and do not gossip their address to other peers. This is implemented as
+// a bloom filter. We can (probabilistically) test for membership, but can't
+// list all discouraged addresses or unmark them as discouraged. Discouragement
+// can prevent our limited connection slots being used up by incompatible
+// or broken peers.
+//
+// Neither banning nor discouragement are protections against denial-of-service
+// attacks, since if an attacker has a way to waste our resources and we
+// disconnect from them and ban that address, it's trivial for them to
+// reconnect from another IP address.
+//
+// Attempting to automatically disconnect or ban any class of peer carries the
+// risk of splitting the network. For example, if we banned/disconnected for a
+// transaction that fails a policy check and a future version changes the
+// policy check so the transaction is accepted, then that transaction could
+// cause the network to split between old nodes and new nodes.
+
+class BanMan
+{
+public:
+    ~BanMan();
+    BanMan(fs::path ban_file, CClientUIInterface* client_interface, int64_t default_ban_time);
+    void Ban(const CNetAddr& net_addr, int64_t ban_time_offset = 0, bool since_unix_epoch = false);
+    void Ban(const CSubNet& sub_net, int64_t ban_time_offset = 0, bool since_unix_epoch = false);
+    void Discourage(const CNetAddr& net_addr);
+    void ClearBanned();
+
+    //! Return whether net_addr is banned
+    bool IsBanned(const CNetAddr& net_addr);
+
+    //! Return whether sub_net is exactly banned
+    bool IsBanned(const CSubNet& sub_net);
+
+    //! Return whether net_addr is discouraged.
+    bool IsDiscouraged(const CNetAddr& net_addr);
+
+    bool Unban(const CNetAddr& net_addr);
+    bool Unban(const CSubNet& sub_net);
+    void GetBanned(banmap_t& banmap);
+    void DumpBanlist();
+
+private:
+    bool BannedSetIsDirty();
+    //!set the "dirty" flag for the banlist
+    void SetBannedSetDirty(bool dirty = true);
+    //!clean unused entries (if bantime has expired)
+    void SweepBanned();
+
+    RecursiveMutex m_cs_banned;
+    banmap_t m_banned GUARDED_BY(m_cs_banned);
+    bool m_is_dirty GUARDED_BY(m_cs_banned);
+    CClientUIInterface* m_client_interface = nullptr;
+    CBanDB m_ban_db;
+    const int64_t m_default_ban_time;
+    CRollingBloomFilter m_discouraged GUARDED_BY(m_cs_banned) {50000, 0.000001};
+};
+
+#endif