Merge #14605: Return of the Banman

18185b57c32d0a43afeca4c125b9352c692923e9 scripted-diff: batch-recase BanMan variables (Carl Dong)
c2e04d37f3841d109c1fe60693f9622e2836cc29 banman: Add, use CBanEntry ctor that takes ban reason (Carl Dong)
1ffa4ce27d4ea6c1067d8984455df97994c7713e banman: reformulate nBanUtil calculation (Carl Dong)
daae598feb034f2f56e0b00ecfb4854d693d3641 banman: add thread annotations and mark members const where possible (Cory Fields)
84fc3fbd0304a7d6e660bf783c84bed2dd415141 scripted-diff: batch-rename BanMan members (Cory Fields)
af3503d903b1a608cd212e2d74b274103199078c net: move BanMan to its own files (Cory Fields)
d0469b2e9386a7a4b268cb9725347e7517acace6 banman: pass in default ban time as a parameter (Cory Fields)
2e56702ecedd83c4b7cb8de9de5c437c8c08e645 banman: pass the banfile path in (Cory Fields)
4c0d961eb0d7825a1e6f8389d7f5545114ee18c6 banman: create and split out banman (Cory Fields)
83c1ea2e5e66b8a83072e3d5ad6a4ced406eb1ba net: split up addresses/ban dumps in preparation for moving them (Cory Fields)
136bd7926c72659dd277a7b795ea17f72e523338 tests: remove member connman/peerLogic in TestingSetup (Cory Fields)
7cc2b9f6786f9bc33853220551eed33ca6b7b7b2 net: Break disconnecting out of Ban() (Cory Fields)

Pull request description:

  **Old English à la Beowulf**
  ```
  Banman wæs bréme    --blaéd wíde sprang--
  Connmanes eafera    Coreum in.
  aéglaéca            léodum forstandan
  Swá bealdode        bearn Connmanes
  guma gúðum cúð      gódum daédum·
  dréah æfter dóme·   nealles druncne slóg
  ```

  **Modern English Translation**
  ```
  Banman was famed              --his renown spread wide--
  Conman's hier,                in Core-land.
  against the evil creature     defend the people
  Thus he was bold,             the son of Connman
  man famed in war,             for good deeds;
  he led his life for glory,    never, having drunk, slew
  ```

  --

  With @theuni's blessing, here is Banman, rebased. Original PR: https://github.com/bitcoin/bitcoin/pull/11457

  --

  Followup PRs:
  1. Give `CNode` a `Disconnect` method ([source](https://github.com/bitcoin/bitcoin/pull/14605#discussion_r248065847))
  2. Add a comment to `std::atomic_bool fDisconnect` in `net.h` that setting this to true will cause the node to be disconnected the next time `DisconnectNodes()` runs ([source](https://github.com/bitcoin/bitcoin/pull/14605#discussion_r248384309))

Tree-SHA512: 9c207edbf577415c22c9811113e393322d936a843d4ff265186728152a67c057779ac4d4f27b895de9729f7a53e870f828b9ebc8bcdab757520c2aebe1e9be35

1 files changed, 197 insertions, 0 deletions

diff --git a/src/banman.cpp b/src/banman.cpp
new file mode 100644
index 0000000000..9933c829c5
--- /dev/null
+++ b/src/banman.cpp
@@ -0,0 +1,197 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2017 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <banman.h>
+
+#include <netaddress.h>
+#include <ui_interface.h>
+#include <util/system.h>
+#include <util/time.h>
+
+
+BanMan::BanMan(fs::path ban_file, CClientUIInterface* client_interface, int64_t default_ban_time)
+    : m_client_interface(client_interface), m_ban_db(std::move(ban_file)), m_default_ban_time(default_ban_time)
+{
+    if (m_client_interface) m_client_interface->InitMessage(_("Loading banlist..."));
+
+    int64_t n_start = GetTimeMillis();
+    m_is_dirty = false;
+    banmap_t banmap;
+    if (m_ban_db.Read(banmap)) {
+        SetBanned(banmap);        // thread save setter
+        SetBannedSetDirty(false); // no need to write down, just read data
+        SweepBanned();            // sweep out unused entries
+
+        LogPrint(BCLog::NET, "Loaded %d banned node ips/subnets from banlist.dat  %dms\n",
+            banmap.size(), GetTimeMillis() - n_start);
+    } else {
+        LogPrintf("Invalid or missing banlist.dat; recreating\n");
+        SetBannedSetDirty(true); // force write
+        DumpBanlist();
+    }
+}
+
+BanMan::~BanMan()
+{
+    DumpBanlist();
+}
+
+void BanMan::DumpBanlist()
+{
+    SweepBanned(); // clean unused entries (if bantime has expired)
+
+    if (!BannedSetIsDirty()) return;
+
+    int64_t n_start = GetTimeMillis();
+
+    banmap_t banmap;
+    GetBanned(banmap);
+    if (m_ban_db.Write(banmap)) {
+        SetBannedSetDirty(false);
+    }
+
+    LogPrint(BCLog::NET, "Flushed %d banned node ips/subnets to banlist.dat  %dms\n",
+        banmap.size(), GetTimeMillis() - n_start);
+}
+
+void BanMan::ClearBanned()
+{
+    {
+        LOCK(m_cs_banned);
+        m_banned.clear();
+        m_is_dirty = true;
+    }
+    DumpBanlist(); //store banlist to disk
+    if (m_client_interface) m_client_interface->BannedListChanged();
+}
+
+bool BanMan::IsBanned(CNetAddr net_addr)
+{
+    LOCK(m_cs_banned);
+    for (const auto& it : m_banned) {
+        CSubNet sub_net = it.first;
+        CBanEntry ban_entry = it.second;
+
+        if (sub_net.Match(net_addr) && GetTime() < ban_entry.nBanUntil) {
+            return true;
+        }
+    }
+    return false;
+}
+
+bool BanMan::IsBanned(CSubNet sub_net)
+{
+    LOCK(m_cs_banned);
+    banmap_t::iterator i = m_banned.find(sub_net);
+    if (i != m_banned.end()) {
+        CBanEntry ban_entry = (*i).second;
+        if (GetTime() < ban_entry.nBanUntil) {
+            return true;
+        }
+    }
+    return false;
+}
+
+void BanMan::Ban(const CNetAddr& net_addr, const BanReason& ban_reason, int64_t ban_time_offset, bool since_unix_epoch)
+{
+    CSubNet sub_net(net_addr);
+    Ban(sub_net, ban_reason, ban_time_offset, since_unix_epoch);
+}
+
+void BanMan::Ban(const CSubNet& sub_net, const BanReason& ban_reason, int64_t ban_time_offset, bool since_unix_epoch)
+{
+    CBanEntry ban_entry(GetTime(), ban_reason);
+
+    int64_t normalized_ban_time_offset = ban_time_offset;
+    bool normalized_since_unix_epoch = since_unix_epoch;
+    if (ban_time_offset <= 0) {
+        normalized_ban_time_offset = m_default_ban_time;
+        normalized_since_unix_epoch = false;
+    }
+    ban_entry.nBanUntil = (normalized_since_unix_epoch ? 0 : GetTime()) + normalized_ban_time_offset;
+
+    {
+        LOCK(m_cs_banned);
+        if (m_banned[sub_net].nBanUntil < ban_entry.nBanUntil) {
+            m_banned[sub_net] = ban_entry;
+            m_is_dirty = true;
+        } else
+            return;
+    }
+    if (m_client_interface) m_client_interface->BannedListChanged();
+
+    //store banlist to disk immediately if user requested ban
+    if (ban_reason == BanReasonManuallyAdded) DumpBanlist();
+}
+
+bool BanMan::Unban(const CNetAddr& net_addr)
+{
+    CSubNet sub_net(net_addr);
+    return Unban(sub_net);
+}
+
+bool BanMan::Unban(const CSubNet& sub_net)
+{
+    {
+        LOCK(m_cs_banned);
+        if (m_banned.erase(sub_net) == 0) return false;
+        m_is_dirty = true;
+    }
+    if (m_client_interface) m_client_interface->BannedListChanged();
+    DumpBanlist(); //store banlist to disk immediately
+    return true;
+}
+
+void BanMan::GetBanned(banmap_t& banmap)
+{
+    LOCK(m_cs_banned);
+    // Sweep the banlist so expired bans are not returned
+    SweepBanned();
+    banmap = m_banned; //create a thread safe copy
+}
+
+void BanMan::SetBanned(const banmap_t& banmap)
+{
+    LOCK(m_cs_banned);
+    m_banned = banmap;
+    m_is_dirty = true;
+}
+
+void BanMan::SweepBanned()
+{
+    int64_t now = GetTime();
+    bool notify_ui = false;
+    {
+        LOCK(m_cs_banned);
+        banmap_t::iterator it = m_banned.begin();
+        while (it != m_banned.end()) {
+            CSubNet sub_net = (*it).first;
+            CBanEntry ban_entry = (*it).second;
+            if (now > ban_entry.nBanUntil) {
+                m_banned.erase(it++);
+                m_is_dirty = true;
+                notify_ui = true;
+                LogPrint(BCLog::NET, "%s: Removed banned node ip/subnet from banlist.dat: %s\n", __func__, sub_net.ToString());
+            } else
+                ++it;
+        }
+    }
+    // update UI
+    if (notify_ui && m_client_interface) {
+        m_client_interface->BannedListChanged();
+    }
+}
+
+bool BanMan::BannedSetIsDirty()
+{
+    LOCK(m_cs_banned);
+    return m_is_dirty;
+}
+
+void BanMan::SetBannedSetDirty(bool dirty)
+{
+    LOCK(m_cs_banned); //reuse m_banned lock for the m_is_dirty flag
+    m_is_dirty = dirty;
+}