1 files changed, 42 insertions, 202 deletions

diff --git a/src/net.cpp b/src/net.cpp
index 98bd518ec..be249b446 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -9,6 +9,7 @@
 
 #include <net.h>
 
+#include <banman.h>
 #include <chainparams.h>
 #include <clientversion.h>
 #include <consensus/consensus.h>
@@ -41,8 +42,8 @@
 
 #include <math.h>
 
-// Dump addresses to peers.dat and banlist.dat every 15 minutes (900s)
-#define DUMP_ADDRESSES_INTERVAL 900
+// Dump addresses to peers.dat every 15 minutes (900s)
+static constexpr int DUMP_PEERS_INTERVAL = 15 * 60;
 
 // We add a random period time (0 to 1 seconds) to feeler connections to prevent synchronization.
 #define FEELER_SLEEP_WINDOW 1
@@ -457,26 +458,6 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
     return pnode;
 }
 
-void CConnman::DumpBanlist()
-{
-    SweepBanned(); // clean unused entries (if bantime has expired)
-
-    if (!BannedSetIsDirty())
-        return;
-
-    int64_t nStart = GetTimeMillis();
-
-    CBanDB bandb;
-    banmap_t banmap;
-    GetBanned(banmap);
-    if (bandb.Write(banmap)) {
-        SetBannedSetDirty(false);
-    }
-
-    LogPrint(BCLog::NET, "Flushed %d banned node ips/subnets to banlist.dat  %dms\n",
-        banmap.size(), GetTimeMillis() - nStart);
-}
-
 void CNode::CloseSocketDisconnect()
 {
     fDisconnect = true;
@@ -488,157 +469,6 @@ void CNode::CloseSocketDisconnect()
     }
 }
 
-void CConnman::ClearBanned()
-{
-    {
-        LOCK(cs_setBanned);
-        setBanned.clear();
-        setBannedIsDirty = true;
-    }
-    DumpBanlist(); //store banlist to disk
-    if(clientInterface)
-        clientInterface->BannedListChanged();
-}
-
-bool CConnman::IsBanned(CNetAddr ip)
-{
-    LOCK(cs_setBanned);
-    for (const auto& it : setBanned) {
-        CSubNet subNet = it.first;
-        CBanEntry banEntry = it.second;
-
-        if (subNet.Match(ip) && GetTime() < banEntry.nBanUntil) {
-            return true;
-        }
-    }
-    return false;
-}
-
-bool CConnman::IsBanned(CSubNet subnet)
-{
-    LOCK(cs_setBanned);
-    banmap_t::iterator i = setBanned.find(subnet);
-    if (i != setBanned.end())
-    {
-        CBanEntry banEntry = (*i).second;
-        if (GetTime() < banEntry.nBanUntil) {
-            return true;
-        }
-    }
-    return false;
-}
-
-void CConnman::Ban(const CNetAddr& addr, const BanReason &banReason, int64_t bantimeoffset, bool sinceUnixEpoch) {
-    CSubNet subNet(addr);
-    Ban(subNet, banReason, bantimeoffset, sinceUnixEpoch);
-}
-
-void CConnman::Ban(const CSubNet& subNet, const BanReason &banReason, int64_t bantimeoffset, bool sinceUnixEpoch) {
-    CBanEntry banEntry(GetTime());
-    banEntry.banReason = banReason;
-    if (bantimeoffset <= 0)
-    {
-        bantimeoffset = gArgs.GetArg("-bantime", DEFAULT_MISBEHAVING_BANTIME);
-        sinceUnixEpoch = false;
-    }
-    banEntry.nBanUntil = (sinceUnixEpoch ? 0 : GetTime() )+bantimeoffset;
-
-    {
-        LOCK(cs_setBanned);
-        if (setBanned[subNet].nBanUntil < banEntry.nBanUntil) {
-            setBanned[subNet] = banEntry;
-            setBannedIsDirty = true;
-        }
-        else
-            return;
-    }
-    if(clientInterface)
-        clientInterface->BannedListChanged();
-    {
-        LOCK(cs_vNodes);
-        for (CNode* pnode : vNodes) {
-            if (subNet.Match(static_cast<CNetAddr>(pnode->addr)))
-                pnode->fDisconnect = true;
-        }
-    }
-    if(banReason == BanReasonManuallyAdded)
-        DumpBanlist(); //store banlist to disk immediately if user requested ban
-}
-
-bool CConnman::Unban(const CNetAddr &addr) {
-    CSubNet subNet(addr);
-    return Unban(subNet);
-}
-
-bool CConnman::Unban(const CSubNet &subNet) {
-    {
-        LOCK(cs_setBanned);
-        if (!setBanned.erase(subNet))
-            return false;
-        setBannedIsDirty = true;
-    }
-    if(clientInterface)
-        clientInterface->BannedListChanged();
-    DumpBanlist(); //store banlist to disk immediately
-    return true;
-}
-
-void CConnman::GetBanned(banmap_t &banMap)
-{
-    LOCK(cs_setBanned);
-    // Sweep the banlist so expired bans are not returned
-    SweepBanned();
-    banMap = setBanned; //create a thread safe copy
-}
-
-void CConnman::SetBanned(const banmap_t &banMap)
-{
-    LOCK(cs_setBanned);
-    setBanned = banMap;
-    setBannedIsDirty = true;
-}
-
-void CConnman::SweepBanned()
-{
-    int64_t now = GetTime();
-    bool notifyUI = false;
-    {
-        LOCK(cs_setBanned);
-        banmap_t::iterator it = setBanned.begin();
-        while(it != setBanned.end())
-        {
-            CSubNet subNet = (*it).first;
-            CBanEntry banEntry = (*it).second;
-            if(now > banEntry.nBanUntil)
-            {
-                setBanned.erase(it++);
-                setBannedIsDirty = true;
-                notifyUI = true;
-                LogPrint(BCLog::NET, "%s: Removed banned node ip/subnet from banlist.dat: %s\n", __func__, subNet.ToString());
-            }
-            else
-                ++it;
-        }
-    }
-    // update UI
-    if(notifyUI && clientInterface) {
-        clientInterface->BannedListChanged();
-    }
-}
-
-bool CConnman::BannedSetIsDirty()
-{
-    LOCK(cs_setBanned);
-    return setBannedIsDirty;
-}
-
-void CConnman::SetBannedSetDirty(bool dirty)
-{
-    LOCK(cs_setBanned); //reuse setBanned lock for the isDirty flag
-    setBannedIsDirty = dirty;
-}
-
-
 bool CConnman::IsWhitelistedRange(const CNetAddr &addr) {
     for (const CSubNet& subnet : vWhitelistedRange) {
         if (subnet.Match(addr))
@@ -934,6 +764,7 @@ struct NodeEvictionCandidate
     bool fBloomFilter;
     CAddress addr;
     uint64_t nKeyedNetGroup;
+    bool prefer_evict;
 };
 
 static bool ReverseCompareNodeMinPingTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b)
@@ -1002,7 +833,8 @@ bool CConnman::AttemptToEvictConnection()
             NodeEvictionCandidate candidate = {node->GetId(), node->nTimeConnected, node->nMinPingUsecTime,
                                                node->nLastBlockTime, node->nLastTXTime,
                                                HasAllDesirableServiceFlags(node->nServices),
-                                               node->fRelayTxes, node->pfilter != nullptr, node->addr, node->nKeyedNetGroup};
+                                               node->fRelayTxes, node->pfilter != nullptr, node->addr, node->nKeyedNetGroup,
+                                               node->m_prefer_evict};
             vEvictionCandidates.push_back(candidate);
         }
     }
@@ -1027,6 +859,14 @@ bool CConnman::AttemptToEvictConnection()
 
     if (vEvictionCandidates.empty()) return false;
 
+    // If any remaining peers are preferred for eviction consider only them.
+    // This happens after the other preferences since if a peer is really the best by other criteria (esp relaying blocks)
+    //  then we probably don't want to evict it no matter what.
+    if (std::any_of(vEvictionCandidates.begin(),vEvictionCandidates.end(),[](NodeEvictionCandidate const &n){return n.prefer_evict;})) {
+        vEvictionCandidates.erase(std::remove_if(vEvictionCandidates.begin(),vEvictionCandidates.end(),
+                                  [](NodeEvictionCandidate const &n){return !n.prefer_evict;}),vEvictionCandidates.end());
+    }
+
     // Identify the network group with the most connections and youngest member.
     // (vEvictionCandidates is already sorted by reverse connect time)
     uint64_t naMostConnections;
@@ -1107,7 +947,11 @@ void CConnman::AcceptConnection(const ListenSocket& hListenSocket) {
     // on all platforms.  Set it again here just to be sure.
     SetSocketNoDelay(hSocket);
 
-    if (IsBanned(addr) && !whitelisted)
+    int bannedlevel = m_banman ? m_banman->IsBannedLevel(addr) : 0;
+
+    // Don't accept connections from banned peers, but if our inbound slots aren't almost full, accept
+    // if the only banning reason was an automatic misbehavior ban.
+    if (!whitelisted && bannedlevel > ((nInbound + 1 < nMaxInbound) ? 1 : 0))
     {
         LogPrint(BCLog::NET, "connection from %s dropped (banned)\n", addr.ToString());
         CloseSocket(hSocket);
@@ -1131,6 +975,7 @@ void CConnman::AcceptConnection(const ListenSocket& hListenSocket) {
     CNode* pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addr, CalculateKeyedNetGroup(addr), nonce, addr_bind, "", true);
     pnode->AddRef();
     pnode->fWhitelisted = whitelisted;
+    pnode->m_prefer_evict = bannedlevel > 0;
     m_msgproc->InitializeNode(pnode);
 
     LogPrint(BCLog::NET, "connection from %s accepted\n", addr.ToString());
@@ -1775,12 +1620,6 @@ void CConnman::DumpAddresses()
            addrman.size(), GetTimeMillis() - nStart);
 }
 
-void CConnman::DumpData()
-{
-    DumpAddresses();
-    DumpBanlist();
-}
-
 void CConnman::ProcessOneShot()
 {
     std::string strDest;
@@ -2085,7 +1924,7 @@ void CConnman::OpenNetworkConnection(const CAddress& addrConnect, bool fCountFai
     }
     if (!pszDest) {
         if (IsLocal(addrConnect) ||
-            FindNode(static_cast<CNetAddr>(addrConnect)) || IsBanned(addrConnect) ||
+            FindNode(static_cast<CNetAddr>(addrConnect)) || (m_banman && m_banman->IsBanned(addrConnect)) ||
             FindNode(addrConnect.ToStringIPPort()))
             return;
     } else if (FindNode(std::string(pszDest)))
@@ -2386,24 +2225,6 @@ bool CConnman::Start(CScheduler& scheduler, const Options& connOptions)
             DumpAddresses();
         }
     }
-    if (clientInterface)
-        clientInterface->InitMessage(_("Loading banlist..."));
-    // Load addresses from banlist.dat
-    nStart = GetTimeMillis();
-    CBanDB bandb;
-    banmap_t banmap;
-    if (bandb.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() - nStart);
-    } else {
-        LogPrintf("Invalid or missing banlist.dat; recreating\n");
-        SetBannedSetDirty(true); // force write
-        DumpBanlist();
-    }
 
     uiInterface.InitMessage(_("Starting network threads..."));
 
@@ -2457,7 +2278,7 @@ bool CConnman::Start(CScheduler& scheduler, const Options& connOptions)
     threadMessageHandler = std::thread(&TraceThread<std::function<void()> >, "msghand", std::function<void()>(std::bind(&CConnman::ThreadMessageHandler, this)));
 
     // Dump network addresses
-    scheduler.scheduleEvery(std::bind(&CConnman::DumpData, this), DUMP_ADDRESSES_INTERVAL * 1000);
+    scheduler.scheduleEvery(std::bind(&CConnman::DumpAddresses, this), DUMP_PEERS_INTERVAL * 1000);
 
     return true;
 }
@@ -2516,7 +2337,7 @@ void CConnman::Stop()
 
     if (fAddressesInitialized)
     {
-        DumpData();
+        DumpAddresses();
         fAddressesInitialized = false;
     }
 
@@ -2643,6 +2464,25 @@ bool CConnman::DisconnectNode(const std::string& strNode)
     }
     return false;
 }
+
+bool CConnman::DisconnectNode(const CSubNet& subnet)
+{
+    bool disconnected = false;
+    LOCK(cs_vNodes);
+    for (CNode* pnode : vNodes) {
+        if (subnet.Match(pnode->addr)) {
+            pnode->fDisconnect = true;
+            disconnected = true;
+        }
+    }
+    return disconnected;
+}
+
+bool CConnman::DisconnectNode(const CNetAddr& addr)
+{
+    return DisconnectNode(CSubNet(addr));
+}
+
 bool CConnman::DisconnectNode(NodeId id)
 {
     LOCK(cs_vNodes);