Introduce -maxuploadtarget

* -maxuploadtarget can be set in MiB
* if <limit> - ( time-left-in-24h-cycle / 600 * MAX_BLOCK_SIZE ) has reach, stop serve blocks older than one week and filtered blocks
* no action if limit has reached, no guarantee that the target will not be  surpassed
* add outbound limit informations to rpc getnettotals

Zcash: Also includes a cleanup from bitcoin/bitcoin#5697

src/init.cpp

@@ -396,6 +396,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-whitebind=<addr>", _("Bind to given address and whitelist peers connecting to it. Use [host]:port notation for IPv6"));
     strUsage += HelpMessageOpt("-whitelist=<netmask>", _("Whitelist peers connecting from the given netmask or IP address. Can be specified multiple times.") +
         " " + _("Whitelisted peers cannot be DoS banned and their transactions are always relayed, even if they are already in the mempool, useful e.g. for a gateway"));
+    strUsage += HelpMessageOpt("-maxuploadtarget=<n>", strprintf(_("Tries to keep outbound traffic under the given target (in MiB per 24h), 0 = no limit (default: %d)"), 0));
 
 #ifdef ENABLE_WALLET
     strUsage += CWallet::GetWalletHelpString(showDebug);
@@ -1374,6 +1375,9 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
         RegisterValidationInterface(pzmqNotificationInterface);
     }
 #endif
+    if (mapArgs.count("-maxuploadtarget")) {
+        CNode::SetMaxOutboundTarget(GetArg("-maxuploadtarget", 0)*1024*1024);
+    }
 
     // ********************************************************* Step 7: load block chain
 

src/main.cpp

@@ -5547,6 +5547,16 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam
                         }
                     }
                 }
+                // disconnect node in case we have reached the outbound limit for serving historical blocks
+                static const int nOneWeek = 7 * 24 * 60 * 60; // assume > 1 week = historical
+                if (send && CNode::OutboundTargetReached(true) && ( ((pindexBestHeader != NULL) && (pindexBestHeader->GetBlockTime() - mi->second->GetBlockTime() > nOneWeek)) || inv.type == MSG_FILTERED_BLOCK) )
+                {
+                    LogPrint("net", "historical block serving limit reached, disconnect peer=%d\n", pfrom->GetId());
+
+                    //disconnect node
+                    pfrom->fDisconnect = true;
+                    send = false;
+                }
                 // Pruned nodes may have deleted the block, so check whether
                 // it's available before trying to send.
                 if (send && (mi->second->nStatus & BLOCK_HAVE_DATA))

src/net.cpp

@@ -322,6 +322,11 @@ uint64_t CNode::nTotalBytesSent = 0;
 CCriticalSection CNode::cs_totalBytesRecv;
 CCriticalSection CNode::cs_totalBytesSent;
 
+uint64_t CNode::nMaxOutboundLimit = 0;
+uint64_t CNode::nMaxOutboundTotalBytesSentInCycle = 0;
+uint64_t CNode::nMaxOutboundTimeframe = 60*60*24; //1 day
+uint64_t CNode::nMaxOutboundCycleStartTime = 0;
+
 CNode* FindNode(const CNetAddr& ip)
 {
     LOCK(cs_vNodes);
@@ -2002,6 +2007,94 @@ void CNode::RecordBytesSent(uint64_t bytes)
 {
     LOCK(cs_totalBytesSent);
     nTotalBytesSent += bytes;
+
+    uint64_t now = GetTime();
+    if (nMaxOutboundCycleStartTime + nMaxOutboundTimeframe < now)
+    {
+        // timeframe expired, reset cycle
+        nMaxOutboundCycleStartTime = now;
+        nMaxOutboundTotalBytesSentInCycle = 0;
+    }
+
+    // TODO, exclude whitebind peers
+    nMaxOutboundTotalBytesSentInCycle += bytes;
+}
+
+void CNode::SetMaxOutboundTarget(uint64_t limit)
+{
+    LOCK(cs_totalBytesSent);
+    uint64_t recommendedMinimum = (nMaxOutboundTimeframe / 600) * MAX_BLOCK_SIZE;
+    nMaxOutboundLimit = limit;
+
+    if (limit < recommendedMinimum)
+        LogPrintf("Max outbound target is very small (%s) and will be overshot. Recommended minimum is %s\n.", nMaxOutboundLimit, recommendedMinimum);
+}
+
+uint64_t CNode::GetMaxOutboundTarget()
+{
+    LOCK(cs_totalBytesSent);
+    return nMaxOutboundLimit;
+}
+
+uint64_t CNode::GetMaxOutboundTimeframe()
+{
+    LOCK(cs_totalBytesSent);
+    return nMaxOutboundTimeframe;
+}
+
+uint64_t CNode::GetMaxOutboundTimeLeftInCycle()
+{
+    LOCK(cs_totalBytesSent);
+    if (nMaxOutboundLimit == 0)
+        return 0;
+
+    if (nMaxOutboundCycleStartTime == 0)
+        return nMaxOutboundTimeframe;
+
+    uint64_t cycleEndTime = nMaxOutboundCycleStartTime + nMaxOutboundTimeframe;
+    uint64_t now = GetTime();
+    return (cycleEndTime < now) ? 0 : cycleEndTime - GetTime();
+}
+
+void CNode::SetMaxOutboundTimeframe(uint64_t timeframe)
+{
+    LOCK(cs_totalBytesSent);
+    if (nMaxOutboundTimeframe != timeframe)
+    {
+        // reset measure-cycle in case of changing
+        // the timeframe
+        nMaxOutboundCycleStartTime = GetTime();
+    }
+    nMaxOutboundTimeframe = timeframe;
+}
+
+bool CNode::OutboundTargetReached(bool historicalBlockServingLimit)
+{
+    LOCK(cs_totalBytesSent);
+    if (nMaxOutboundLimit == 0)
+        return false;
+
+    if (historicalBlockServingLimit)
+    {
+        // keep a large enought buffer to at least relay each block once
+        uint64_t timeLeftInCycle = GetMaxOutboundTimeLeftInCycle();
+        uint64_t buffer = timeLeftInCycle / 600 * MAX_BLOCK_SIZE;
+        if (buffer >= nMaxOutboundLimit || nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit - buffer)
+            return true;
+    }
+    else if (nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit)
+        return true;
+
+    return false;
+}
+
+uint64_t CNode::GetOutboundTargetBytesLeft()
+{
+    LOCK(cs_totalBytesSent);
+    if (nMaxOutboundLimit == 0)
+        return 0;
+
+    return (nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit) ? 0 : nMaxOutboundLimit - nMaxOutboundTotalBytesSentInCycle;
 }
 
 uint64_t CNode::GetTotalBytesRecv()

src/net.h

@@ -358,6 +358,12 @@ private:
     static uint64_t nTotalBytesRecv;
     static uint64_t nTotalBytesSent;
 
+    // outbound limit & stats
+    static uint64_t nMaxOutboundTotalBytesSentInCycle;
+    static uint64_t nMaxOutboundCycleStartTime;
+    static uint64_t nMaxOutboundLimit;
+    static uint64_t nMaxOutboundTimeframe;
+
     CNode(const CNode&);
     void operator=(const CNode&);
 
@@ -665,6 +671,27 @@ public:
 
     static uint64_t GetTotalBytesRecv();
     static uint64_t GetTotalBytesSent();
+
+    //!set the max outbound target in bytes
+    static void SetMaxOutboundTarget(uint64_t limit);
+    static uint64_t GetMaxOutboundTarget();
+
+    //!set the timeframe for the max outbound target
+    static void SetMaxOutboundTimeframe(uint64_t timeframe);
+    static uint64_t GetMaxOutboundTimeframe();
+
+    //!check if the outbound target is reached
+    // if param historicalBlockServingLimit is set true, the function will
+    // response true if the limit for serving historical blocks has been reached
+    static bool OutboundTargetReached(bool historicalBlockServingLimit);
+
+    //!response the bytes left in the current max outbound cycle
+    // in case of no limit, it will always response 0
+    static uint64_t GetOutboundTargetBytesLeft();
+
+    //!response the time in second left in the current max outbound cycle
+    // in case of no limit, it will always response 0
+    static uint64_t GetMaxOutboundTimeLeftInCycle();
 };
 
 

src/rpc/net.cpp

@@ -374,6 +374,15 @@ UniValue getnettotals(const UniValue& params, bool fHelp)
     obj.pushKV("totalbytesrecv", CNode::GetTotalBytesRecv());
     obj.pushKV("totalbytessent", CNode::GetTotalBytesSent());
     obj.pushKV("timemillis", GetTimeMillis());
+
+    UniValue outboundLimit(UniValue::VOBJ);
+    outboundLimit.pushKV("timeframe", CNode::GetMaxOutboundTimeframe());
+    outboundLimit.pushKV("target", CNode::GetMaxOutboundTarget());
+    outboundLimit.pushKV("target_reached", CNode::OutboundTargetReached(false));
+    outboundLimit.pushKV("serve_historical_blocks", !CNode::OutboundTargetReached(true));
+    outboundLimit.pushKV("bytes_left_in_cycle", CNode::GetOutboundTargetBytesLeft());
+    outboundLimit.pushKV("time_left_in_cycle", CNode::GetMaxOutboundTimeLeftInCycle());
+    obj.pushKV("uploadtarget", outboundLimit);
     return obj;
 }