Files
thehub/hub/server/timedata.cpp
tomFlowee 008eb35f95 Make compile faster
The IDE include checker got to the point where it is actually useful and
this removes a lot of unneeded includes.
Naturally, especially for headers like util.h, this may mean we need to
re-add includes in consuming cpp files that bloats the diff a bit.
2026-05-14 13:27:17 +02:00

124 lines
4.1 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>
#include <utiltime.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;
}
}