tomFlowee
b4a3da2642
These are technically static libs, but not in any way shared libs. They are used solely only by this repo and really only by the hub. Most important, no header files are installed and basically none of the normal rules for reusable libraries are applied to these files.
123 lines
4.0 KiB
C++
123 lines
4.0 KiB
C++
/*
|
|
* This file is part of the Flowee project
|
|
* Copyright (C) 2014-2015 The Bitcoin Core developers
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "timedata.h"
|
|
|
|
#include <netbase.h>
|
|
#include <sync.h>
|
|
#include "UiInterface.h"
|
|
#include "serverutil.h"
|
|
#include <utilstrencodings.h>
|
|
|
|
static CCriticalSection cs_nTimeOffset;
|
|
static int64_t nTimeOffset = 0;
|
|
|
|
/**
|
|
* "Never go to sea with two chronometers; take one or three."
|
|
* Our three time sources are:
|
|
* - System clock
|
|
* - Median of other nodes clocks
|
|
* - The user (asking the user to fix the system clock if the first two disagree)
|
|
*/
|
|
int64_t GetTimeOffset()
|
|
{
|
|
LOCK(cs_nTimeOffset);
|
|
return nTimeOffset;
|
|
}
|
|
|
|
int64_t GetAdjustedTime()
|
|
{
|
|
return GetTime() + GetTimeOffset();
|
|
}
|
|
|
|
static int64_t abs64(int64_t n)
|
|
{
|
|
return (n >= 0 ? n : -n);
|
|
}
|
|
|
|
#define BITCOIN_TIMEDATA_MAX_SAMPLES 200
|
|
|
|
void AddTimeData(const CNetAddr& ip, int64_t nOffsetSample)
|
|
{
|
|
LOCK(cs_nTimeOffset);
|
|
// Ignore duplicates
|
|
static std::set<CNetAddr> setKnown;
|
|
if (setKnown.size() == BITCOIN_TIMEDATA_MAX_SAMPLES)
|
|
return;
|
|
if (!setKnown.insert(ip).second)
|
|
return;
|
|
|
|
// Add data
|
|
static CMedianFilter<int64_t> vTimeOffsets(BITCOIN_TIMEDATA_MAX_SAMPLES, 0);
|
|
vTimeOffsets.input(nOffsetSample);
|
|
logDebug(Log::Net) << "added time data, samples" << vTimeOffsets.size() << "offset" << nOffsetSample << "minutes:" << nOffsetSample / 60;
|
|
|
|
// There is a known issue here (see issue #4521):
|
|
//
|
|
// - The structure vTimeOffsets contains up to 200 elements, after which
|
|
// any new element added to it will not increase its size, replacing the
|
|
// oldest element.
|
|
//
|
|
// - The condition to update nTimeOffset includes checking whether the
|
|
// number of elements in vTimeOffsets is odd, which will never happen after
|
|
// there are 200 elements.
|
|
//
|
|
// But in this case the 'bug' is protective against some attacks, and may
|
|
// actually explain why we've never seen attacks which manipulate the
|
|
// clock offset.
|
|
//
|
|
// So we should hold off on fixing this and clean it up as part of
|
|
// a timing cleanup that strengthens it in a number of other ways.
|
|
//
|
|
if (vTimeOffsets.size() >= 5 && vTimeOffsets.size() % 2 == 1)
|
|
{
|
|
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)
|
|
{
|
|
nTimeOffset = nMedian;
|
|
}
|
|
else
|
|
{
|
|
nTimeOffset = 0;
|
|
|
|
static bool fDone;
|
|
if (!fDone)
|
|
{
|
|
// If nobody has a time different than ours but within 5 minutes of ours, give a warning
|
|
bool fMatch = false;
|
|
for (int64_t nOffset : vSorted)
|
|
if (nOffset != 0 && abs64(nOffset) < 5 * 60)
|
|
fMatch = true;
|
|
|
|
if (!fMatch)
|
|
{
|
|
fDone = true;
|
|
std::string strMessage = _("Please check that your computer's date and time are correct! If your clock is wrong Flowee will not work properly.");
|
|
strMiscWarning = strMessage;
|
|
uiInterface.ThreadSafeMessageBox(strMessage, "", CClientUIInterface::MSG_WARNING);
|
|
}
|
|
}
|
|
}
|
|
|
|
logDebug(Log::Net) << "TimeData:" << vSorted;
|
|
logDebug(Log::Net) << "nTimeOffset" << nTimeOffset << "minutes:" << nTimeOffset / 60;
|
|
}
|
|
}
|