From 1c844177804cd96ad5c2be08ecc5919450570eb6 Mon Sep 17 00:00:00 2001
From: "Wladimir J. van der Laan" <laanwj@gmail.com>
Date: Wed, 30 Mar 2016 09:31:32 +0200
Subject: [PATCH] Merge #7573: P2P: add maxtimeadjustment command line option

e1523ce P2P: add maxtimeadjustment command line option (mruddy)
---
 src/init.cpp     | 2 ++
 src/timedata.cpp | 2 +-
 src/timedata.h   | 2 ++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/init.cpp b/src/init.cpp
index 7d3d9368b8..9ba00521f7 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -32,6 +32,7 @@
 #include "script/standard.h"
 #include "script/sigcache.h"
 #include "scheduler.h"
+#include "timedata.h"
 #include "txdb.h"
 #include "txmempool.h"
 #include "torcontrol.h"
@@ -446,6 +447,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-maxconnections=<n>", strprintf(_("Maintain at most <n> connections to peers (temporary service connections excluded) (default: %u)"), DEFAULT_MAX_PEER_CONNECTIONS));
     strUsage += HelpMessageOpt("-maxreceivebuffer=<n>", strprintf(_("Maximum per-connection receive buffer, <n>*1000 bytes (default: %u)"), DEFAULT_MAXRECEIVEBUFFER));
     strUsage += HelpMessageOpt("-maxsendbuffer=<n>", strprintf(_("Maximum per-connection send buffer, <n>*1000 bytes (default: %u)"), DEFAULT_MAXSENDBUFFER));
+    strUsage += HelpMessageOpt("-maxtimeadjustment", strprintf(_("Maximum allowed median peer time offset adjustment. Local perspective of time may be influenced by peers forward or backward by this amount. (default: %u seconds)"), DEFAULT_MAX_TIME_ADJUSTMENT));
     strUsage += HelpMessageOpt("-onion=<ip:port>", strprintf(_("Use separate SOCKS5 proxy to reach peers via Tor hidden services (default: %s)"), "-proxy"));
     strUsage += HelpMessageOpt("-onlynet=<net>", _("Only connect to nodes in network <net> (ipv4, ipv6 or onion)"));
     strUsage += HelpMessageOpt("-permitbaremultisig", strprintf(_("Relay non-P2SH multisig (default: %u)"), DEFAULT_PERMIT_BAREMULTISIG));
diff --git a/src/timedata.cpp b/src/timedata.cpp
index 172c940e5b..774eff51a8 100644
--- a/src/timedata.cpp
+++ b/src/timedata.cpp
@@ -83,7 +83,7 @@ void AddTimeData(const CNetAddr& ip, int64_t nOffsetSample)
         int64_t nMedian = vTimeOffsets.median();
         std::vector<int64_t> vSorted = vTimeOffsets.sorted();
         // Only let other nodes change our time by so much
-        if (abs64(nMedian) < 70 * 60)
+        if (abs64(nMedian) <= std::max<int64_t>(0, GetArg("-maxtimeadjustment", DEFAULT_MAX_TIME_ADJUSTMENT)))
         {
             nTimeOffset = nMedian;
         }
diff --git a/src/timedata.h b/src/timedata.h
index 2296baf11b..9f2499c85c 100644
--- a/src/timedata.h
+++ b/src/timedata.h
@@ -10,6 +10,8 @@
 #include <stdint.h>
 #include <vector>
 
+static const int64_t DEFAULT_MAX_TIME_ADJUSTMENT = 70 * 60;
+
 class CNetAddr;
 
 /**