Introduce -maxoutconnections= to set the maximum number of outbound connections

3 files changed, 8 insertions, 5 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 8223e3282..1737bb069 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -230,6 +230,7 @@ std::string HelpMessage(HelpMessageMode hmm)
     strUsage += "  -externalip=<ip>       " + _("Specify your own public address") + "\n";
     strUsage += "  -listen                " + _("Accept connections from outside (default: 1 if no -proxy or -connect)") + "\n";
     strUsage += "  -maxconnections=<n>    " + _("Maintain at most <n> connections to peers (default: 125)") + "\n";
+    strUsage += "  -maxoutconnections=<n> " + _("Maintain at most <n> outbound connections to peers (default: 8)") + "\n";
     strUsage += "  -maxreceivebuffer=<n>  " + _("Maximum per-connection receive buffer, <n>*1000 bytes (default: 5000)") + "\n";
     strUsage += "  -maxsendbuffer=<n>     " + _("Maximum per-connection send buffer, <n>*1000 bytes (default: 1000)") + "\n";
     strUsage += "  -onion=<ip:port>       " + _("Use separate SOCKS5 proxy to reach peers via Tor hidden services (default: -proxy)") + "\n";
@@ -535,6 +536,8 @@ bool AppInit2(boost::thread_group& threadGroup)
     if (nFD - MIN_CORE_FILEDESCRIPTORS < nMaxConnections)
         nMaxConnections = nFD - MIN_CORE_FILEDESCRIPTORS;
 
+    nMaxOutboundConnections = GetArg("-maxoutconnections", 8);
+    nMaxOutboundConnections = std::min(std::max(nMaxOutboundConnections, 2), nMaxConnections);
     // ********************************************************* Step 3: parameter-to-internal-flags
 
     fDebug = !mapMultiArgs["-debug"].empty();
diff --git a/src/net.cpp b/src/net.cpp
index 425989b3b..f337447ff 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -39,8 +39,6 @@
 using namespace std;
 using namespace boost;
 
-static const int MAX_OUTBOUND_CONNECTIONS = 8;
-
 bool OpenNetworkConnection(const CAddress& addrConnect, CSemaphoreGrant *grantOutbound = NULL, const char *strDest = NULL, bool fOneShot = false);
 
 
@@ -59,6 +57,7 @@ uint64_t nLocalHostNonce = 0;
 static std::vector<SOCKET> vhListenSocket;
 CAddrMan addrman;
 int nMaxConnections = 125;
+int nMaxOutboundConnections = 8;
 
 vector<CNode*> vNodes;
 CCriticalSection cs_vNodes;
@@ -916,7 +915,7 @@ void ThreadSocketHandler()
                 if (nErr != WSAEWOULDBLOCK)
                     LogPrintf("socket error accept failed: %s\n", NetworkErrorString(nErr));
             }
-            else if (nInbound >= nMaxConnections - MAX_OUTBOUND_CONNECTIONS)
+            else if (nInbound >= nMaxConnections - nMaxOutboundConnections)
             {
                 closesocket(hSocket);
             }
@@ -1709,7 +1708,7 @@ void StartNode(boost::thread_group& threadGroup)
 {
     if (semOutbound == NULL) {
         // initialize semaphore
-        int nMaxOutbound = min(MAX_OUTBOUND_CONNECTIONS, nMaxConnections);
+        int nMaxOutbound = min(nMaxOutboundConnections, nMaxConnections);
         semOutbound = new CSemaphore(nMaxOutbound);
     }
 
@@ -1753,7 +1752,7 @@ bool StopNode()
     LogPrintf("StopNode()\n");
     MapPort(false);
     if (semOutbound)
-        for (int i=0; i<MAX_OUTBOUND_CONNECTIONS; i++)
+        for (int i=0; i<nMaxOutboundConnections; i++)
             semOutbound->post();
     MilliSleep(50);
     DumpAddresses();
diff --git a/src/net.h b/src/net.h
index cb07156bd..5862129fa 100644
--- a/src/net.h
+++ b/src/net.h
@@ -104,6 +104,7 @@ extern uint64_t nLocalServices;
 extern uint64_t nLocalHostNonce;
 extern CAddrMan addrman;
 extern int nMaxConnections;
+extern int nMaxOutboundConnections;
 
 extern std::vector<CNode*> vNodes;
 extern CCriticalSection cs_vNodes;