better local address discovery for active mn (#1203)

* Make local address discovery more robust in CActiveMasternode

* parameter interaction: -masternode=1 -> setting -listen=1

*  slightly postpone first run to give net thread a chance to connect to some peers

* make sure local address detected in CActiveMasternode::ManageStateInitial is valid

* Simplified address detection logic

src/activemasternode.cpp

@@ -127,10 +127,43 @@ bool CActiveMasternode::SendMasternodePing()
 void CActiveMasternode::ManageStateInitial()
 {
     LogPrint("masternode", "CActiveMasternode::ManageStateInitial -- status = %s, type = %s, pinger enabled = %d\n", GetStatus(), GetTypeString(), fPingerEnabled);
+
     // Check that our local network configuration is correct
-    if(!GetLocal(service)) {
+    if (!fListen) {
+        // listen option is probably overwritten by smth else, no good
         nState = ACTIVE_MASTERNODE_NOT_CAPABLE;
-        strNotCapableReason = "Can't detect external address. Please consider using the externalip configuration option if problem persists.";
+        strNotCapableReason = "Masternode must accept connections from outside. Make sure listen configuration option is not overwritten by some another parameter.";
+        LogPrintf("CActiveMasternode::ManageStateInitial -- %s: %s\n", GetStateString(), strNotCapableReason);
+        return;
+    }
+
+    bool fFoundLocal = false;
+    {
+        LOCK(cs_vNodes);
+
+        // First try to find whatever local address is specified by externalip option
+        fFoundLocal = GetLocal(service) && CMasternode::IsValidNetAddr(service);
+        if(!fFoundLocal) {
+            // nothing and no live connections, can't do anything for now
+            if (vNodes.empty()) {
+                nState = ACTIVE_MASTERNODE_NOT_CAPABLE;
+                strNotCapableReason = "Can't detect valid external address. Will retry when there are some connections available.";
+                LogPrintf("CActiveMasternode::ManageStateInitial -- %s: %s\n", GetStateString(), strNotCapableReason);
+                return;
+            }
+            // We have some peers, let's try to find our local address from one of them
+            BOOST_FOREACH(CNode* pnode, vNodes) {
+                if (pnode->fSuccessfullyConnected && pnode->addr.IsIPv4()) {
+                    fFoundLocal = GetLocal(service, &pnode->addr) && CMasternode::IsValidNetAddr(service);
+                    if(fFoundLocal) break;
+                }
+            }
+        }
+    }
+
+    if(!fFoundLocal) {
+        nState = ACTIVE_MASTERNODE_NOT_CAPABLE;
+        strNotCapableReason = "Can't detect valid external address. Please consider using the externalip configuration option if problem persists. Make sure to use IPv4 address only.";
         LogPrintf("CActiveMasternode::ManageStateInitial -- %s: %s\n", GetStateString(), strNotCapableReason);
         return;
     }
@@ -150,7 +183,7 @@ void CActiveMasternode::ManageStateInitial()
         return;
     }
 
-    LogPrintf("CActiveMasternode::ManageState -- Checking inbound connection to '%s'\n", service.ToString());
+    LogPrintf("CActiveMasternode::ManageStateInitial -- Checking inbound connection to '%s'\n", service.ToString());
 
     if(!ConnectNode((CAddress)service, NULL, true)) {
         nState = ACTIVE_MASTERNODE_NOT_CAPABLE;

src/darksend.cpp

@@ -2479,8 +2479,8 @@ void ThreadCheckDarkSendPool()
             nTick++;
 
             // check if we should activate or ping every few minutes,
-            // start right after sync is considered to be done
-            if(nTick % MASTERNODE_MIN_MNP_SECONDS == 1)
+            // slightly postpone first run to give net thread a chance to connect to some peers
+            if(nTick % MASTERNODE_MIN_MNP_SECONDS == 15)
                 activeMasternode.ManageState();
 
             mnodeman.Check();

src/init.cpp

@@ -797,6 +797,12 @@ void InitParameterInteraction()
             LogPrintf("%s: parameter interaction: -whitebind set -> setting -listen=1\n", __func__);
     }
 
+    if (GetBoolArg("-masternode", false)) {
+        // masternodes must accept connections from outside
+        if (SoftSetBoolArg("-listen", true))
+            LogPrintf("%s: parameter interaction: -masternode=1 -> setting -listen=1\n", __func__);
+    }
+
     if (mapArgs.count("-connect") && mapMultiArgs["-connect"].size() > 0) {
         // when only connecting to trusted nodes, do not seed via DNS, or listen by default
         if (SoftSetBoolArg("-dnsseed", false))

src/masternode.cpp

@@ -273,11 +273,16 @@ void CMasternode::Check(bool fForce)
 }
 
 bool CMasternode::IsValidNetAddr()
+{
+    return IsValidNetAddr(addr);
+}
+
+bool CMasternode::IsValidNetAddr(CService addrIn)
 {
     // TODO: regtest is fine with any addresses for now,
     // should probably be a bit smarter if one day we start to implement tests for this
     return Params().NetworkIDString() == CBaseChainParams::REGTEST ||
-            (addr.IsIPv4() && IsReachable(addr) && addr.IsRoutable());
+            (addrIn.IsIPv4() && IsReachable(addrIn) && addrIn.IsRoutable());
 }
 
 masternode_info_t CMasternode::GetInfo()

src/masternode.h

@@ -274,6 +274,7 @@ public:
     }
 
     bool IsValidNetAddr();
+    static bool IsValidNetAddr(CService addrIn);
 
     void IncreasePoSeBanScore() { if(nPoSeBanScore < MASTERNODE_POSE_BAN_MAX_SCORE) nPoSeBanScore++; }
     void DecreasePoSeBanScore() { if(nPoSeBanScore > -MASTERNODE_POSE_BAN_MAX_SCORE) nPoSeBanScore--; }