1 files changed, 50 insertions, 37 deletions

diff --git a/src/net.cpp b/src/net.cpp
index 391c229ebc..935cb81901 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -444,7 +444,6 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
         uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE).Write(id).Finalize();
         CAddress addr_bind = GetBindAddress(hSocket);
         CNode* pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addrConnect, CalculateKeyedNetGroup(addrConnect), nonce, addr_bind, pszDest ? pszDest : "", false);
-        pnode->nServicesExpected = ServiceFlags(addrConnect.nServices & nRelevantServices);
         pnode->AddRef();
 
         return pnode;
@@ -685,7 +684,7 @@ void CNode::copyStats(CNodeStats &stats)
         X(cleanSubVer);
     }
     X(fInbound);
-    X(fAddnode);
+    X(m_manual_connection);
     X(nStartingHeight);
     {
         LOCK(cs_vSend);
@@ -995,7 +994,7 @@ bool CConnman::AttemptToEvictConnection()
                 continue;
             NodeEvictionCandidate candidate = {node->GetId(), node->nTimeConnected, node->nMinPingUsecTime,
                                                node->nLastBlockTime, node->nLastTXTime,
-                                               (node->nServices & nRelevantServices) == nRelevantServices,
+                                               HasAllDesirableServiceFlags(node->nServices),
                                                node->fRelayTxes, node->pfilter != nullptr, node->addr, node->nKeyedNetGroup};
             vEvictionCandidates.push_back(candidate);
         }
@@ -1593,7 +1592,7 @@ void CConnman::ThreadDNSAddressSeed()
         LOCK(cs_vNodes);
         int nRelevant = 0;
         for (auto pnode : vNodes) {
-            nRelevant += pnode->fSuccessfullyConnected && ((pnode->nServices & nRelevantServices) == nRelevantServices);
+            nRelevant += pnode->fSuccessfullyConnected && !pnode->fFeeler && !pnode->fOneShot && !pnode->m_manual_connection && !pnode->fInbound;
         }
         if (nRelevant >= 2) {
             LogPrintf("P2P peers available. Skipped DNS seeding.\n");
@@ -1615,7 +1614,7 @@ void CConnman::ThreadDNSAddressSeed()
         } else {
             std::vector<CNetAddr> vIPs;
             std::vector<CAddress> vAdd;
-            ServiceFlags requiredServiceBits = nRelevantServices;
+            ServiceFlags requiredServiceBits = GetDesirableServiceFlags(NODE_NONE);
             std::string host = GetDNSHost(seed, &requiredServiceBits);
             CNetAddr resolveSource;
             if (!resolveSource.SetInternal(host)) {
@@ -1685,6 +1684,37 @@ void CConnman::ProcessOneShot()
     }
 }
 
+bool CConnman::GetTryNewOutboundPeer()
+{
+    return m_try_another_outbound_peer;
+}
+
+void CConnman::SetTryNewOutboundPeer(bool flag)
+{
+    m_try_another_outbound_peer = flag;
+    LogPrint(BCLog::NET, "net: setting try another outbound peer=%s\n", flag ? "true" : "false");
+}
+
+// Return the number of peers we have over our outbound connection limit
+// Exclude peers that are marked for disconnect, or are going to be
+// disconnected soon (eg one-shots and feelers)
+// Also exclude peers that haven't finished initial connection handshake yet
+// (so that we don't decide we're over our desired connection limit, and then
+// evict some peer that has finished the handshake)
+int CConnman::GetExtraOutboundCount()
+{
+    int nOutbound = 0;
+    {
+        LOCK(cs_vNodes);
+        for (CNode* pnode : vNodes) {
+            if (!pnode->fInbound && !pnode->m_manual_connection && !pnode->fFeeler && !pnode->fDisconnect && !pnode->fOneShot && pnode->fSuccessfullyConnected) {
+                ++nOutbound;
+            }
+        }
+    }
+    return std::max(nOutbound - nMaxOutbound, 0);
+}
+
 void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
 {
     // Connect to specific addresses
@@ -1696,7 +1726,7 @@ void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
             for (const std::string& strAddr : connect)
             {
                 CAddress addr(CService(), NODE_NONE);
-                OpenNetworkConnection(addr, false, nullptr, strAddr.c_str());
+                OpenNetworkConnection(addr, false, nullptr, strAddr.c_str(), false, false, true);
                 for (int i = 0; i < 10 && i < nLoop; i++)
                 {
                     if (!interruptNet.sleep_for(std::chrono::milliseconds(500)))
@@ -1744,17 +1774,11 @@ void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
         // Only connect out to one peer per network group (/16 for IPv4).
         // Do this here so we don't have to critsect vNodes inside mapAddresses critsect.
         int nOutbound = 0;
-        int nOutboundRelevant = 0;
         std::set<std::vector<unsigned char> > setConnected;
         {
             LOCK(cs_vNodes);
             for (CNode* pnode : vNodes) {
-                if (!pnode->fInbound && !pnode->fAddnode) {
-
-                    // Count the peers that have all relevant services
-                    if (pnode->fSuccessfullyConnected && !pnode->fFeeler && ((pnode->nServices & nRelevantServices) == nRelevantServices)) {
-                        nOutboundRelevant++;
-                    }
+                if (!pnode->fInbound && !pnode->m_manual_connection) {
                     // Netgroups for inbound and addnode peers are not excluded because our goal here
                     // is to not use multiple of our limited outbound slots on a single netgroup
                     // but inbound and addnode peers do not use our outbound slots.  Inbound peers
@@ -1779,7 +1803,8 @@ void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
         //  * Only make a feeler connection once every few minutes.
         //
         bool fFeeler = false;
-        if (nOutbound >= nMaxOutbound) {
+
+        if (nOutbound >= nMaxOutbound && !GetTryNewOutboundPeer()) {
             int64_t nTime = GetTimeMicros(); // The current time right now (in microseconds).
             if (nTime > nNextFeeler) {
                 nNextFeeler = PoissonNextSend(nTime, FEELER_INTERVAL);
@@ -1809,21 +1834,16 @@ void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
             if (IsLimited(addr))
                 continue;
 
-            // only connect to full nodes
-            if ((addr.nServices & REQUIRED_SERVICES) != REQUIRED_SERVICES)
-                continue;
-
             // only consider very recently tried nodes after 30 failed attempts
             if (nANow - addr.nLastTry < 600 && nTries < 30)
                 continue;
 
-            // only consider nodes missing relevant services after 40 failed attempts and only if less than half the outbound are up.
-            ServiceFlags nRequiredServices = nRelevantServices;
-            if (nTries >= 40 && nOutbound < (nMaxOutbound >> 1)) {
-                nRequiredServices = REQUIRED_SERVICES;
-            }
-
-            if ((addr.nServices & nRequiredServices) != nRequiredServices) {
+            // for non-feelers, require all the services we'll want,
+            // for feelers, only require they be a full node (only because most
+            // SPV clients don't have a good address DB available)
+            if (!fFeeler && !HasAllDesirableServiceFlags(addr.nServices)) {
+                continue;
+            } else if (fFeeler && !MayHaveUsefulAddressDB(addr.nServices)) {
                 continue;
             }
 
@@ -1832,13 +1852,6 @@ void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
                 continue;
 
             addrConnect = addr;
-
-            // regardless of the services assumed to be available, only require the minimum if half or more outbound have relevant services
-            if (nOutboundRelevant >= (nMaxOutbound >> 1)) {
-                addrConnect.nServices = REQUIRED_SERVICES;
-            } else {
-                addrConnect.nServices = nRequiredServices;
-            }
             break;
         }
 
@@ -1937,7 +1950,7 @@ void CConnman::ThreadOpenAddedConnections()
 }
 
 // if successful, this moves the passed grant to the constructed node
-bool CConnman::OpenNetworkConnection(const CAddress& addrConnect, bool fCountFailure, CSemaphoreGrant *grantOutbound, const char *pszDest, bool fOneShot, bool fFeeler, bool fAddnode)
+bool CConnman::OpenNetworkConnection(const CAddress& addrConnect, bool fCountFailure, CSemaphoreGrant *grantOutbound, const char *pszDest, bool fOneShot, bool fFeeler, bool manual_connection)
 {
     //
     // Initiate outbound network connection
@@ -1966,8 +1979,8 @@ bool CConnman::OpenNetworkConnection(const CAddress& addrConnect, bool fCountFai
         pnode->fOneShot = true;
     if (fFeeler)
         pnode->fFeeler = true;
-    if (fAddnode)
-        pnode->fAddnode = true;
+    if (manual_connection)
+        pnode->m_manual_connection = true;
 
     m_msgproc->InitializeNode(pnode);
     {
@@ -2214,6 +2227,7 @@ CConnman::CConnman(uint64_t nSeed0In, uint64_t nSeed1In) : nSeed0(nSeed0In), nSe
     semOutbound = nullptr;
     semAddnode = nullptr;
     flagInterruptMsgProc = false;
+    SetTryNewOutboundPeer(false);
 
     Options connOptions;
     Init(connOptions);
@@ -2703,7 +2717,6 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
     nSendVersion(0)
 {
     nServices = NODE_NONE;
-    nServicesExpected = NODE_NONE;
     hSocket = hSocketIn;
     nRecvVersion = INIT_PROTO_VERSION;
     nLastSend = 0;
@@ -2716,7 +2729,7 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
     strSubVer = "";
     fWhitelisted = false;
     fOneShot = false;
-    fAddnode = false;
+    m_manual_connection = false;
     fClient = false; // set by version message
     fFeeler = false;
     fSuccessfullyConnected = false;