banman: save the banlist in a JSON format on disk

Save the banlist in `banlist.json` instead of `banlist.dat`.

This makes it possible to store Tor v3 entries in the banlist on disk
(and any other addresses that cannot be serialized in addrv1 format).

Only read `banlist.dat` if it exists and `banlist.json` does not
exist (first start after an upgrade).

Supersedes https://github.com/bitcoin/bitcoin/pull/20904
Resolves https://github.com/bitcoin/bitcoin/issues/19748

1 files changed, 12 insertions, 21 deletions

diff --git a/src/banman.cpp b/src/banman.cpp
index bb97fc4809..d2437e6733 100644
--- a/src/banman.cpp
+++ b/src/banman.cpp
@@ -18,20 +18,18 @@ BanMan::BanMan(fs::path ban_file, CClientUIInterface* client_interface, int64_t
     if (m_client_interface) m_client_interface->InitMessage(_("Loading banlist…").translated);
 
     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
+    if (m_ban_db.Read(m_banned, m_is_dirty)) {
+        SweepBanned(); // sweep out unused entries
 
-        LogPrint(BCLog::NET, "Loaded %d banned node ips/subnets from banlist.dat  %dms\n",
-            m_banned.size(), GetTimeMillis() - n_start);
+        LogPrint(BCLog::NET, "Loaded %d banned node addresses/subnets  %dms\n", m_banned.size(),
+                 GetTimeMillis() - n_start);
     } else {
-        LogPrintf("Recreating banlist.dat\n");
-        SetBannedSetDirty(true); // force write
-        DumpBanlist();
+        LogPrintf("Recreating the banlist database\n");
+        m_banned = {};
+        m_is_dirty = true;
     }
+
+    DumpBanlist();
 }
 
 BanMan::~BanMan()
@@ -53,8 +51,8 @@ void BanMan::DumpBanlist()
         SetBannedSetDirty(false);
     }
 
-    LogPrint(BCLog::NET, "Flushed %d banned node ips/subnets to banlist.dat  %dms\n",
-        banmap.size(), GetTimeMillis() - n_start);
+    LogPrint(BCLog::NET, "Flushed %d banned node addresses/subnets to disk  %dms\n", banmap.size(),
+             GetTimeMillis() - n_start);
 }
 
 void BanMan::ClearBanned()
@@ -167,13 +165,6 @@ void BanMan::GetBanned(banmap_t& banmap)
     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();
@@ -188,7 +179,7 @@ void BanMan::SweepBanned()
                 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());
+                LogPrint(BCLog::NET, "Removed banned node address/subnet: %s\n", sub_net.ToString());
             } else
                 ++it;
         }