src/alert.cpp
//
// Alert system
//
#include <algorithm>
#include <boost/algorithm/string/classification.hpp>
#include <boost/algorithm/string/replace.hpp>
#include <boost/foreach.hpp>
#include <map>
#include "alert.h"
#include "chainparams.h"
#include "key.h"
#include "net.h"
#include "sync.h"
#include "ui_interface.h"
std::map<uint256, CAlert> mapAlerts;
CCriticalSection cs_mapAlerts;
void CUnsignedAlert::SetNull()
{
nVersion = 1;
nRelayUntil = 0;
nExpiration = 0;
nID = 0;
nCancel = 0;
setCancel.clear();
nMinVer = 0;
nMaxVer = 0;
setSubVer.clear();
nPriority = 0;
strComment.clear();
strStatusBar.clear();
strReserved.clear();
}
std::string CUnsignedAlert::ToString() const
{
std::string strSetCancel;
BOOST_FOREACH(int n, setCancel)
strSetCancel += strprintf("%d ", n);
std::string strSetSubVer;
BOOST_FOREACH(std::string str, setSubVer)
strSetSubVer += "\"" + str + "\" ";
return strprintf(
"CAlert(\n"
" nVersion = %d\n"
" nRelayUntil = %d\n"
" nExpiration = %d\n"
" nID = %d\n"
" nCancel = %d\n"
" setCancel = %s\n"
" nMinVer = %d\n"
" nMaxVer = %d\n"
" setSubVer = %s\n"
" nPriority = %d\n"
" strComment = \"%s\"\n"
" strStatusBar = \"%s\"\n"
")\n",
nVersion,
nRelayUntil,
nExpiration,
nID,
nCancel,
strSetCancel.c_str(),
nMinVer,
nMaxVer,
strSetSubVer.c_str(),
nPriority,
strComment.c_str(),
strStatusBar.c_str());
}
void CUnsignedAlert::print() const
{
LogPrintf("%s", ToString().c_str());
}
void CAlert::SetNull()
{
CUnsignedAlert::SetNull();
vchMsg.clear();
vchSig.clear();
}
bool CAlert::IsNull() const
{
return (nExpiration == 0);
}
uint256 CAlert::GetHash() const
{
return Hash(this->vchMsg.begin(), this->vchMsg.end());
}
bool CAlert::IsInEffect() const
{
return (GetAdjustedTime() < nExpiration);
}
bool CAlert::Cancels(const CAlert& alert) const
{
if (!IsInEffect())
return false; // this was a no-op before 31403
return (alert.nID <= nCancel || setCancel.count(alert.nID));
}
bool CAlert::AppliesTo(int nVersion, std::string strSubVerIn) const
{
// TODO: rework for client-version-embedded-in-strSubVer ?
return (IsInEffect() &&
nMinVer <= nVersion && nVersion <= nMaxVer &&
(setSubVer.empty() || setSubVer.count(strSubVerIn)));
}
bool CAlert::AppliesToMe() const
{
return AppliesTo(PROTOCOL_VERSION, FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, std::vector<std::string>()));
}
bool CAlert::RelayTo(CNode* pnode) const
{
if (!IsInEffect())
return false;
// returns true if wasn't already contained in the set
if (pnode->setKnown.insert(GetHash()).second)
{
if (AppliesTo(pnode->nVersion, pnode->strSubVer) ||
AppliesToMe() ||
GetAdjustedTime() < nRelayUntil)
{
pnode->PushMessage("alert", *this);
return true;
}
}
return false;
}
bool CAlert::CheckSignature() const
{
CPubKey key(Params().AlertKey());
if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
return error("CAlert::CheckSignature() : verify signature failed");
// Now unserialize the data
CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
sMsg >> *(CUnsignedAlert*)this;
return true;
}
CAlert CAlert::getAlertByHash(const uint256 &hash)
{
CAlert retval;
{
LOCK(cs_mapAlerts);
std::map<uint256, CAlert>::iterator mi = mapAlerts.find(hash);
if(mi != mapAlerts.end())
retval = mi->second;
}
return retval;
}
bool CAlert::ProcessAlert(bool fThread)
{
if (!CheckSignature())
return false;
if (!IsInEffect())
return false;
// alert.nID=max is reserved for if the alert key is
// compromised. It must have a pre-defined message,
// must never expire, must apply to all versions,
// and must cancel all previous
// alerts or it will be ignored (so an attacker can't
// send an "everything is OK, don't panic" version that
// cannot be overridden):
int maxInt = std::numeric_limits<int>::max();
if (nID == maxInt)
{
if (!(
nExpiration == maxInt &&
nCancel == (maxInt-1) &&
nMinVer == 0 &&
nMaxVer == maxInt &&
setSubVer.empty() &&
nPriority == maxInt &&
strStatusBar == "URGENT: Alert key compromised, upgrade required"
))
return false;
}
{
LOCK(cs_mapAlerts);
// Cancel previous alerts
for (std::map<uint256, CAlert>::iterator mi = mapAlerts.begin(); mi != mapAlerts.end();)
{
const CAlert& alert = (*mi).second;
if (Cancels(alert))
{
LogPrintf("cancelling alert %d\n", alert.nID);
uiInterface.NotifyAlertChanged((*mi).first, CT_DELETED);
mapAlerts.erase(mi++);
} else
if (!alert.IsInEffect())
{
LogPrintf("expiring alert %d\n", alert.nID);
uiInterface.NotifyAlertChanged((*mi).first, CT_DELETED);
mapAlerts.erase(mi++);
} else
{
mi++;
}
}
// Check if this alert has been cancelled
BOOST_FOREACH(PAIRTYPE(const uint256, CAlert)& item, mapAlerts)
{
const CAlert& alert = item.second;
if (alert.Cancels(*this))
{
LogPrintf("alert already cancelled by %d\n", alert.nID);
return false;
}
}
// Add to mapAlerts
mapAlerts.insert(std::make_pair(GetHash(), *this));
// Notify UI and -alertnotify if it applies to me
if(AppliesToMe())
{
uiInterface.NotifyAlertChanged(GetHash(), CT_NEW);
std::string strCmd = GetArg("-alertnotify", "");
if (!strCmd.empty())
{
// Alert text should be plain ascii coming from a trusted source, but to
// be safe we first strip anything not in safeChars, then add single quotes around
// the whole string before passing it to the shell:
std::string singleQuote("'");
// safeChars chosen to allow simple messages/URLs/email addresses, but avoid anything
// even possibly remotely dangerous like & or >
std::string safeChars("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890 .,;_/:?@");
std::string safeStatus;
for (std::string::size_type i = 0; i < strStatusBar.size(); i++)
{
if (safeChars.find(strStatusBar[i]) != std::string::npos)
safeStatus.push_back(strStatusBar[i]);
}
safeStatus = singleQuote+safeStatus+singleQuote;
boost::replace_all(strCmd, "%s", safeStatus);
if (fThread)
boost::thread t(runCommand, strCmd); // thread runs free
else
runCommand(strCmd);
}
}
}
LogPrintf("accepted alert %d, AppliesToMe()=%d\n", nID, AppliesToMe());
return true;
}