1 files changed, 64 insertions, 323 deletions

diff --git a/src/net.cpp b/src/net.cpp
index 86e5225839..1335804b06 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
@@ -57,17 +58,6 @@
 #define MSG_DONTWAIT 0
 #endif
 
-// Fix for ancient MinGW versions, that don't have defined these in ws2tcpip.h.
-// Todo: Can be removed when our pull-tester is upgraded to a modern MinGW version.
-#ifdef WIN32
-#ifndef PROTECTION_LEVEL_UNRESTRICTED
-#define PROTECTION_LEVEL_UNRESTRICTED 10
-#endif
-#ifndef IPV6_PROTECTION_LEVEL
-#define IPV6_PROTECTION_LEVEL 23
-#endif
-#endif
-
 /** Used to pass flags to the Bind() function */
 enum BindFlags {
     BF_NONE         = 0,
@@ -95,8 +85,6 @@ std::map<CNetAddr, LocalServiceInfo> mapLocalHost GUARDED_BY(cs_mapLocalHost);
 static bool vfLimited[NET_MAX] GUARDED_BY(cs_mapLocalHost) = {};
 std::string strSubVersion;
 
-limitedmap<uint256, int64_t> mapAlreadyAskedFor(MAX_INV_SZ);
-
 void CConnman::AddOneShot(const std::string& strDest)
 {
     LOCK(cs_vOneShots);
@@ -173,8 +161,7 @@ CAddress GetLocalAddress(const CNetAddr *paddrPeer, ServiceFlags nLocalServices)
 static int GetnScore(const CService& addr)
 {
     LOCK(cs_mapLocalHost);
-    if (mapLocalHost.count(addr) == LOCAL_NONE)
-        return 0;
+    if (mapLocalHost.count(addr) == 0) return 0;
     return mapLocalHost[addr].nScore;
 }
 
@@ -183,7 +170,7 @@ bool IsPeerAddrLocalGood(CNode *pnode)
 {
     CService addrLocal = pnode->GetAddrLocal();
     return fDiscover && pnode->addr.IsRoutable() && addrLocal.IsRoutable() &&
-           !IsLimited(addrLocal.GetNetwork());
+           IsReachable(addrLocal.GetNetwork());
 }
 
 // pushes our own address to a peer
@@ -222,7 +209,7 @@ bool AddLocal(const CService& addr, int nScore)
     if (!fDiscover && nScore < LOCAL_MANUAL)
         return false;
 
-    if (IsLimited(addr))
+    if (!IsReachable(addr))
         return false;
 
     LogPrintf("AddLocal(%s,%i)\n", addr.ToString(), nScore);
@@ -252,24 +239,23 @@ void RemoveLocal(const CService& addr)
     mapLocalHost.erase(addr);
 }
 
-/** Make a particular network entirely off-limits (no automatic connects to it) */
-void SetLimited(enum Network net, bool fLimited)
+void SetReachable(enum Network net, bool reachable)
 {
     if (net == NET_UNROUTABLE || net == NET_INTERNAL)
         return;
     LOCK(cs_mapLocalHost);
-    vfLimited[net] = fLimited;
+    vfLimited[net] = !reachable;
 }
 
-bool IsLimited(enum Network net)
+bool IsReachable(enum Network net)
 {
     LOCK(cs_mapLocalHost);
-    return vfLimited[net];
+    return !vfLimited[net];
 }
 
-bool IsLimited(const CNetAddr &addr)
+bool IsReachable(const CNetAddr &addr)
 {
-    return IsLimited(addr.GetNetwork());
+    return IsReachable(addr.GetNetwork());
 }
 
 /** vote for a local address */
@@ -292,19 +278,6 @@ bool IsLocal(const CService& addr)
     return mapLocalHost.count(addr) > 0;
 }
 
-/** check whether a given network is one we can probably connect to */
-bool IsReachable(enum Network net)
-{
-    return !IsLimited(net);
-}
-
-/** check whether a given address is in a network we can probably connect to */
-bool IsReachable(const CNetAddr& addr)
-{
-    return IsReachable(addr.GetNetwork());
-}
-
-
 CNode* CConnman::FindNode(const CNetAddr& ip)
 {
     LOCK(cs_vNodes);
@@ -471,26 +444,6 @@ 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;
@@ -502,157 +455,6 @@ 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))
@@ -948,6 +750,7 @@ struct NodeEvictionCandidate
     bool fBloomFilter;
     CAddress addr;
     uint64_t nKeyedNetGroup;
+    bool prefer_evict;
 };
 
 static bool ReverseCompareNodeMinPingTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b)
@@ -1016,7 +819,8 @@ 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);
         }
     }
@@ -1041,6 +845,14 @@ 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;
@@ -1121,7 +933,11 @@ 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);
@@ -1145,6 +961,7 @@ 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());
@@ -1789,12 +1606,6 @@ void CConnman::DumpAddresses()
            addrman.size(), GetTimeMillis() - nStart);
 }
 
-void CConnman::DumpData()
-{
-    DumpAddresses();
-    DumpBanlist();
-}
-
 void CConnman::ProcessOneShot()
 {
     std::string strDest;
@@ -1954,9 +1765,15 @@ void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
                 addr = addrman.Select(fFeeler);
             }
 
-            // if we selected an invalid address, restart
-            if (!addr.IsValid() || setConnected.count(addr.GetGroup()) || IsLocal(addr))
+            // Require outbound connections, other than feelers, to be to distinct network groups
+            if (!fFeeler && setConnected.count(addr.GetGroup())) {
+                break;
+            }
+
+            // if we selected an invalid or local address, restart
+            if (!addr.IsValid() || IsLocal(addr)) {
                 break;
+            }
 
             // If we didn't find an appropriate destination after trying 100 addresses fetched from addrman,
             // stop this loop, and let the outer loop run again (which sleeps, adds seed nodes, recalculates
@@ -1965,7 +1782,7 @@ void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
             if (nTries > 100)
                 break;
 
-            if (IsLimited(addr))
+            if (!IsReachable(addr))
                 continue;
 
             // only consider very recently tried nodes after 30 failed attempts
@@ -2099,7 +1916,7 @@ 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)))
@@ -2327,7 +2144,7 @@ NodeId CConnman::GetNewNodeId()
 
 
 bool CConnman::Bind(const CService &addr, unsigned int flags) {
-    if (!(flags & BF_EXPLICIT) && IsLimited(addr))
+    if (!(flags & BF_EXPLICIT) && !IsReachable(addr))
         return false;
     std::string strError;
     if (!BindListenPort(addr, strError, (flags & BF_WHITELIST) != 0)) {
@@ -2400,24 +2217,6 @@ 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..."));
 
@@ -2471,7 +2270,7 @@ 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;
 }
@@ -2530,7 +2329,7 @@ void CConnman::Stop()
 
     if (fAddressesInitialized)
     {
-        DumpData();
+        DumpAddresses();
         fAddressesInitialized = false;
     }
 
@@ -2657,6 +2456,25 @@ 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);
@@ -2794,8 +2612,8 @@ int CConnman::GetBestHeight() const
 
 unsigned int CConnman::GetReceiveFloodSize() const { return nReceiveFloodSize; }
 
-CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress& addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const CAddress &addrBindIn, const std::string& addrNameIn, bool fInboundIn) :
-    nTimeConnected(GetSystemTimeInSeconds()),
+CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress& addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const CAddress& addrBindIn, const std::string& addrNameIn, bool fInboundIn)
+    : nTimeConnected(GetSystemTimeInSeconds()),
     addr(addrIn),
     addrBind(addrBindIn),
     fInbound(fInboundIn),
@@ -2805,56 +2623,13 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
     id(idIn),
     nLocalHostNonce(nLocalHostNonceIn),
     nLocalServices(nLocalServicesIn),
-    nMyStartingHeight(nMyStartingHeightIn),
-    nSendVersion(0)
+    nMyStartingHeight(nMyStartingHeightIn)
 {
-    nServices = NODE_NONE;
     hSocket = hSocketIn;
-    nRecvVersion = INIT_PROTO_VERSION;
-    nLastSend = 0;
-    nLastRecv = 0;
-    nSendBytes = 0;
-    nRecvBytes = 0;
-    nTimeOffset = 0;
     addrName = addrNameIn == "" ? addr.ToStringIPPort() : addrNameIn;
-    nVersion = 0;
-    strSubVer = "";
-    fWhitelisted = false;
-    fOneShot = false;
-    m_manual_connection = false;
-    fClient = false; // set by version message
-    m_limited_node = false; // set by version message
-    fFeeler = false;
-    fSuccessfullyConnected = false;
-    fDisconnect = false;
-    nRefCount = 0;
-    nSendSize = 0;
-    nSendOffset = 0;
     hashContinue = uint256();
-    nStartingHeight = -1;
     filterInventoryKnown.reset();
-    fSendMempool = false;
-    fGetAddr = false;
-    nNextLocalAddrSend = 0;
-    nNextAddrSend = 0;
-    nNextInvSend = 0;
-    fRelayTxes = false;
-    fSentAddr = false;
     pfilter = MakeUnique<CBloomFilter>();
-    timeLastMempoolReq = 0;
-    nLastBlockTime = 0;
-    nLastTXTime = 0;
-    nPingNonceSent = 0;
-    nPingUsecStart = 0;
-    nPingUsecTime = 0;
-    fPingQueued = false;
-    nMinPingUsecTime = std::numeric_limits<int64_t>::max();
-    minFeeFilter = 0;
-    lastSentFeeFilter = 0;
-    nextSendTimeFeeFilter = 0;
-    fPauseRecv = false;
-    fPauseSend = false;
-    nProcessQueueSize = 0;
 
     for (const std::string &msg : getAllNetMessageTypes())
         mapRecvBytesPerMsgCmd[msg] = 0;
@@ -2872,40 +2647,6 @@ CNode::~CNode()
     CloseSocket(hSocket);
 }
 
-void CNode::AskFor(const CInv& inv)
-{
-    if (mapAskFor.size() > MAPASKFOR_MAX_SZ || setAskFor.size() > SETASKFOR_MAX_SZ)
-        return;
-    // a peer may not have multiple non-responded queue positions for a single inv item
-    if (!setAskFor.insert(inv.hash).second)
-        return;
-
-    // We're using mapAskFor as a priority queue,
-    // the key is the earliest time the request can be sent
-    int64_t nRequestTime;
-    limitedmap<uint256, int64_t>::const_iterator it = mapAlreadyAskedFor.find(inv.hash);
-    if (it != mapAlreadyAskedFor.end())
-        nRequestTime = it->second;
-    else
-        nRequestTime = 0;
-    LogPrint(BCLog::NET, "askfor %s  %d (%s) peer=%d\n", inv.ToString(), nRequestTime, FormatISO8601Time(nRequestTime/1000000), id);
-
-    // Make sure not to reuse time indexes to keep things in the same order
-    int64_t nNow = GetTimeMicros() - 1000000;
-    static int64_t nLastTime;
-    ++nLastTime;
-    nNow = std::max(nNow, nLastTime);
-    nLastTime = nNow;
-
-    // Each retry is 2 minutes after the last
-    nRequestTime = std::max(nRequestTime + 2 * 60 * 1000000, nNow);
-    if (it != mapAlreadyAskedFor.end())
-        mapAlreadyAskedFor.update(it, nRequestTime);
-    else
-        mapAlreadyAskedFor.insert(std::make_pair(inv.hash, nRequestTime));
-    mapAskFor.insert(std::make_pair(nRequestTime, inv));
-}
-
 bool CConnman::NodeFullyConnected(const CNode* pnode)
 {
     return pnode && pnode->fSuccessfullyConnected && !pnode->fDisconnect;