twister-core/src/softcheckpoint.cpp
2014-02-14 17:43:44 -02:00

285 lines
12 KiB
C++

// Copyright (c) 2014 Miguel Freitas
// TODO: write description for the soft checkpoint
// More info:
// https://groups.google.com/forum/#!topic/twister-dev/tH3HlVQ_wmo
#include <boost/assign/list_of.hpp> // for 'map_list_of()'
#include <boost/assign.hpp>
#include <boost/foreach.hpp>
#include "softcheckpoint.h"
#include "main.h"
#include "checkpoints.h"
#include "uint256.h"
#include "script.h"
#include "init.h"
#include "twister.h"
//#define dbgprintf OutputDebugStringF
#define dbgprintf(...) // no debug printf
namespace SoftCheckpoints
{
bool fEnabled = true;
CCriticalSection cs_softCP;
typedef std::pair<int, uint256> Checkpoint; // height, hash
typedef std::map<std::string, std::string> CPSigMap; // user, sign
typedef std::pair<std::string, std::string> CPSigPair; // user, sign
static Checkpoint lastSoftCP;
static CPSigMap lastSoftCPSigs;
static std::map<Checkpoint, CPSigMap> nextCandidates;
static std::map<Checkpoint, CPSigMap> uncheckedCandidates;
static std::set<std::string> uniqueUsersList =
boost::assign::list_of
("mf1")("mf1a")("mf2")("mf2a")("mf3")
("quietpatron")("wn41");
static std::set<std::string> upcomingUsersList =
boost::assign::list_of
("_gltest2")("fcplm_zion");
void SetSoftCPBestChain() {
// requires cs_main and cs_softCP locked (in this order)
if( !fEnabled )
return;
if( lastSoftCP.first && mapBlockIndex.count(lastSoftCP.second) &&
!mapBlockIndex[lastSoftCP.second]->IsInMainChain() ) {
dbgprintf("SoftCheckpoints::SetSoftCPBestChain: lastSoftCP %d not in main chain\n", lastSoftCP.first);
// ? use !mapOrphanBlocks.count() ?
CBlockIndex *pindex = mapBlockIndex[lastSoftCP.second];
while( pindex && !pindex->IsInMainChain() ) {
pindex = pindex->pprev;
}
if( !pindex ) {
dbgprintf("SoftCheckpoints::SetSoftCPBestChain: lastSoftCP %d currently orphaned? strange.\n", lastSoftCP.first);
return;
}
dbgprintf("SoftCheckpoints::SetSoftCPBestChain: trying SetBestChain with lastSoftCP %d\n", lastSoftCP.first);
CValidationState state;
if (!SetBestChain(state, mapBlockIndex[lastSoftCP.second])) {
dbgprintf("SoftCheckpoints::lastSoftCPUpdated: SetBestChain failed\n");
}
}
}
void LastSoftCPUpdated() {
//LOCK(cs_main); // FIXME: not needed if called from ProcessMessage. check. wrong mutex order is bad.
SetSoftCPBestChain();
}
std::string CPtoString(Checkpoint &cp) {
CScript cs = CScript() << cp.first << cp.second;
return std::string((const char *)cs.data(), cs.size());
}
void NewBlockAccepted() {
LOCK(cs_softCP);
SetSoftCPBestChain();
if( (nBestHeight % SOFT_CHECKPOINT_PERIOD) == 0 &&
nBestHeight > Checkpoints::GetHighestCheckpoint() &&
nBestHeight >= lastSoftCP.first + SOFT_CHECKPOINT_PERIOD &&
!fImporting && !fReindex) {
LOCK(pwalletMain->cs_wallet);
BOOST_FOREACH(const PAIRTYPE(CKeyID, CKeyMetadata)& item, pwalletMain->mapKeyMetadata)
{
const std::string &username = item.second.username;
if(uniqueUsersList.count(username) || upcomingUsersList.count(username)) {
int height = nBestHeight - SOFT_CHECKPOINT_PERIOD;
dbgprintf("SoftCheckpoints::NewBlockAccepted: user '%s' will vote for %d\n",
username.c_str(), height);
CBlockIndex* pblockindex = FindBlockByHeight(height);
assert( pblockindex );
Checkpoint cpPair = std::make_pair(height, *pblockindex->phashBlock);
std::string dataToSign = CPtoString(cpPair);
std::string sign = createSignature(dataToSign, username);
if( sign.size() ) {
if( CastVoteSoftCheckpoint(height, *pblockindex->phashBlock, username, sign) ) {
dbgprintf("SoftCheckpoints::NewBlockAccepted: relaying our own vote\n");
CSoftCheckpoint cp;
cp.nHeight = height;
cp.blockHash = *pblockindex->phashBlock;
cp.vchUsername = std::vector<char>(username.begin(), username.end());
cp.vchSign = std::vector<char>(sign.begin(), sign.end());
SoftCheckpoints::RelayCP(cp, NULL);
} else {
dbgprintf("SoftCheckpoints::NewBlockAccepted: CastVoteSoftCheckpoint failed for our own vote!\n");
}
} else {
dbgprintf("SoftCheckpoints::NewBlockAccepted: createSignature failed for user '%s'\n",
username.c_str());
}
break;
}
}
}
if( uncheckedCandidates.size() && nBestHeight > Checkpoints::GetHighestCheckpoint() ) {
// pending unchecked
dbgprintf("SoftCheckpoints::NewBlockAccepted process %zd pending unchecked (not implemented)\n",
uncheckedCandidates.size());
uncheckedCandidates.clear();
}
}
bool CastVerifiedVote(Checkpoint &cp, const std::string &username, const std::string &sign) {
if( cp.first == lastSoftCP.first ) {
if( lastSoftCPSigs.count(username) ) {
dbgprintf("SoftCheckpoints::CastVerifiedVote: '%s' already voted for lastSoftCP %d\n", username.c_str(), cp.first);
return false;
}
if( cp != lastSoftCP ) {
dbgprintf("SoftCheckpoints::CastVerifiedVote: '%s' voted for a different hash than lastSoftCP %d\n", username.c_str(), cp.first);
return false;
}
dbgprintf("SoftCheckpoints::CastVerifiedVote: new vote for lastSoftCP %d by '%s'\n", cp.first, username.c_str());
lastSoftCPSigs[username] = sign;
return true;
}
if( nextCandidates.count(cp) && nextCandidates[cp].count(username) ) {
dbgprintf("SoftCheckpoints::CastVerifiedVote: '%s' already voted for candidate %d\n", username.c_str(), cp.first);
return false;
}
nextCandidates[cp][username] = sign;
if( nextCandidates[cp].size() > uniqueUsersList.size() / 2) {
dbgprintf("SoftCheckpoints::CastVerifiedVote: new soft checkpoint %d wins!\n", cp.first);
lastSoftCP = cp;
lastSoftCPSigs = nextCandidates[cp];
nextCandidates.clear();
LastSoftCPUpdated();
}
return true;
}
// returns true if vote is to be restransmitted
bool CastVoteSoftCheckpoint(int height, const uint256 &hash, const std::string &username, const std::string &sign) {
LOCK(cs_softCP);
if( (height % SOFT_CHECKPOINT_PERIOD) != 0 ) {
dbgprintf("SoftCheckpoints::CastVoteSoftCheckpoint: height %d not multiple of SOFT_CHECKPOINT_PERIOD\n", height);
return false;
}
int hardCheckPointHeight = Checkpoints::GetHighestCheckpoint();
if( height < hardCheckPointHeight ) {
dbgprintf("SoftCheckpoints::CastVoteSoftCheckpoint: height %d < hard checkpoint %d\n", height, hardCheckPointHeight);
return false;
}
if( height < lastSoftCP.first ) {
dbgprintf("SoftCheckpoints::CastVoteSoftCheckpoint: height %d < soft checkpoint %d\n", height, lastSoftCP.first);
return false;
}
if( !uniqueUsersList.count(username) && !upcomingUsersList.count(username) ) {
dbgprintf("SoftCheckpoints::CastVoteSoftCheckpoint: username '%s' not accepted\n", username.c_str());
return false;
}
Checkpoint cp = std::make_pair(height, hash);
if( nBestHeight < hardCheckPointHeight ) {
// still downloading blocks, we can't check signatures yet
dbgprintf("SoftCheckpoints::CastVoteSoftCheckpoint: vote for %d by '%s' added to unchecked\n", height, username.c_str());
uncheckedCandidates[cp][username] = sign;
return false;
}
if( !verifySignature( CPtoString(cp), username, sign) ) {
dbgprintf("SoftCheckpoints::CastVoteSoftCheckpoint: invalid signature by '%s'\n", username.c_str());
return false;
}
dbgprintf("SoftCheckpoints::CastVoteSoftCheckpoint: signature by '%s' verified for %d, casting vote\n",
username.c_str(), height);
return CastVerifiedVote( cp, username, sign );
}
bool CheckBlock(int nHeight, const uint256& hash) {
LOCK(cs_softCP);
if (!fEnabled)
return true;
if (!lastSoftCP.first || nHeight != lastSoftCP.first)
return true;
dbgprintf("SoftCheckpoints::CheckBlock: height %d isOk=%d\n", nHeight, hash == lastSoftCP.second);
return hash == lastSoftCP.second;
}
void RelayCP(const CSoftCheckpoint& cp, CNode* pfrom) {
LOCK(cs_vNodes);
dbgprintf("SoftCheckpoints::RelayCP: relaying softCP height %d from %s\n",
cp.nHeight, !pfrom ? "localhost" : pfrom->addr.ToString().c_str());
BOOST_FOREACH(CNode* pnode, vNodes) {
if(pnode == pfrom)
continue;
if (pnode->nVersion >= SOFT_CHECKPOINT_VERSION) {
dbgprintf("SoftCheckpoints::RelayCP: pushMessage to %s\n", pnode->addr.ToString().c_str());
pnode->PushMessage("cp", cp);
}
}
if( pfrom && lastSoftCP.first == cp.nHeight ) {
if( !mapBlockIndex.count(lastSoftCP.second) ) {
dbgprintf("SoftCheckpoints::RelayCP: requesting block height %d from node\n", cp.nHeight);
PushGetBlocks(pfrom, pindexBest, cp.blockHash);
}
}
}
void RelayLastCPToNode(CNode* pnode) {
LOCK(cs_softCP);
if (!lastSoftCP.first)
return;
if (pnode->nVersion >= SOFT_CHECKPOINT_VERSION) {
dbgprintf("SoftCheckpoints::RelayToLastCP: relaying lastSoftCP height %d (size %zd) to %s\n",
lastSoftCP.first, lastSoftCPSigs.size(), pnode->addr.ToString().c_str());
BOOST_FOREACH(const CPSigMap::value_type& i, lastSoftCPSigs) {
CSoftCheckpoint cp;
cp.nHeight = lastSoftCP.first;
cp.blockHash = lastSoftCP.second;
cp.vchUsername = std::vector<char>(i.first.begin(), i.first.end());
cp.vchSign = std::vector<char>(i.second.begin(), i.second.end());
pnode->PushMessage("cp", cp);
}
}
}
bool GetLastCPVotes(int &height, uint256 &hash, std::set<std::string> &usernames) {
LOCK(cs_softCP);
if (!lastSoftCP.first)
return false;
height = lastSoftCP.first;
hash = lastSoftCP.second;
usernames.clear();
BOOST_FOREACH(const CPSigMap::value_type& i, lastSoftCPSigs) {
usernames.insert(i.first);
}
return true;
}
}