Blocks come down in order (well... unless a peer bugs out).

Peer hash-chains downloaded one-at-once.
KillChain works again.
Local networking option.
Don't resend blocks during sync.

alethzero/Main.ui

@@ -132,6 +132,7 @@
     </property>
     <addaction name="upnp"/>
     <addaction name="usePast"/>
+    <addaction name="localNetworking"/>
     <addaction name="net"/>
     <addaction name="connect"/>
    </widget>
@@ -1731,6 +1732,14 @@ font-size: 14pt</string>
     <string>Reserved Debug 1</string>
    </property>
   </action>
+  <action name="localNetworking">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Enable Local Addresses</string>
+   </property>
+  </action>
  </widget>
  <layoutdefault spacing="6" margin="11"/>
  <customwidgets>

alethzero/MainWin.cpp

@@ -192,7 +192,7 @@ Main::~Main()
 
 dev::p2p::NetworkPreferences Main::netPrefs() const
 {
-	return NetworkPreferences(ui->port->value(), ui->forceAddress->text().toStdString(), ui->upnp->isChecked(), false);
+	return NetworkPreferences(ui->port->value(), ui->forceAddress->text().toStdString(), ui->upnp->isChecked(), ui->localNetworking->isChecked());
 }
 
 void Main::onKeysChanged()
@@ -494,6 +494,7 @@ void Main::writeSettings()
 	s.setValue("upnp", ui->upnp->isChecked());
 	s.setValue("forceAddress", ui->forceAddress->text());
 	s.setValue("usePast", ui->usePast->isChecked());
+	s.setValue("localNetworking", ui->localNetworking->isChecked());
 	s.setValue("forceMining", ui->forceMining->isChecked());
 	s.setValue("paranoia", ui->paranoia->isChecked());
 	s.setValue("showAll", ui->showAll->isChecked());
@@ -543,6 +544,7 @@ void Main::readSettings(bool _skipGeometry)
 	ui->upnp->setChecked(s.value("upnp", true).toBool());
 	ui->forceAddress->setText(s.value("forceAddress", "").toString());
 	ui->usePast->setChecked(s.value("usePast", true).toBool());
+	ui->localNetworking->setChecked(s.value("localNetworking", true).toBool());
 	ui->forceMining->setChecked(s.value("forceMining", false).toBool());
 	on_forceMining_triggered();
 	ui->paranoia->setChecked(s.value("paranoia", false).toBool());
@@ -1419,6 +1421,7 @@ void Main::on_killBlockchain_triggered()
 	writeSettings();
 	ui->mine->setChecked(false);
 	ui->net->setChecked(false);
+	web3()->stopNetwork();
 	ethereum()->killChain();
 	m_ethereum->setClient(ethereum());
 	readSettings(true);

eth/main.cpp

@@ -112,7 +112,8 @@ void help()
         << "    -l,--listen <port>  Listen on the given port for incoming connected (default: 30303)." << endl
 		<< "    -m,--mining <on/off/number>  Enable mining, optionally for a specified number of blocks (Default: off)" << endl
 		<< "    -n,--upnp <on/off>  Use upnp for NAT (default: on)." << endl
-        << "    -o,--mode <full/peer>  Start a full node or a peer node (Default: full)." << endl
+		<< "    -L,--local-networking Use peers whose addresses are local." << endl
+		<< "    -o,--mode <full/peer>  Start a full node or a peer node (Default: full)." << endl
         << "    -p,--port <port>  Connect to remote port (default: 30303)." << endl
         << "    -r,--remote <host>  Connect to remote host (default: none)." << endl
         << "    -s,--secret <secretkeyhex>  Set the secret key for use with send command (default: auto)." << endl
@@ -188,6 +189,7 @@ int main(int argc, char** argv)
 #endif
 	string publicIP;
 	bool upnp = true;
+	bool useLocal = false;
 	bool forceMining = false;
 	string clientName;
 
@@ -233,10 +235,12 @@ int main(int argc, char** argv)
 				upnp = false;
 			else
 			{
-				cerr << "Invalid UPnP option: " << m << endl;
+				cerr << "Invalid -n/--upnp option: " << m << endl;
 				return -1;
 			}
 		}
+		else if (arg == "-L" || arg == "--local-networking")
+			useLocal = true;
 		else if ((arg == "-c" || arg == "--client-name") && i + 1 < argc)
 			clientName = argv[++i];
 		else if ((arg == "-a" || arg == "--address" || arg == "--coinbase-address") && i + 1 < argc)
@@ -256,7 +260,7 @@ int main(int argc, char** argv)
 				mining = i;
 			else
 			{
-				cerr << "Unknown mining option: " << m << endl;
+				cerr << "Unknown -m/--mining option: " << m << endl;
 				return -1;
 			}
 		}
@@ -300,7 +304,7 @@ int main(int argc, char** argv)
 
 	cout << credits();
 
-	NetworkPreferences netPrefs(listenPort, publicIP, upnp, false);
+	NetworkPreferences netPrefs(listenPort, publicIP, upnp, useLocal);
 	dev::WebThreeDirect web3("Ethereum(++)/" + clientName + "v" + dev::Version + "/" DEV_QUOTED(ETH_BUILD_TYPE) "/" DEV_QUOTED(ETH_BUILD_PLATFORM), dbPath, false, mode == NodeMode::Full ? set<string>{"eth", "shh"} : set<string>{}, netPrefs);
 	web3.setIdealPeerCount(peers);
 	eth::Client& c = *web3.ethereum();

libdevcore/Common.cpp

@@ -27,7 +27,7 @@ using namespace dev;
 namespace dev
 {
 
-char const* Version = "0.6.8b";
+char const* Version = "0.6.8c";
 
 }
 

libethcore/CommonEth.cpp

@@ -34,7 +34,7 @@ namespace dev
 namespace eth
 {
 
-const unsigned c_protocolVersion = 32;
+const unsigned c_protocolVersion = 33;
 const unsigned c_databaseVersion = 1;
 
 static const vector<pair<u256, string>> g_units =

libethereum/BlockChain.cpp

@@ -108,6 +108,20 @@ bytes BlockChain::createGenesisBlock()
 }
 
 BlockChain::BlockChain(std::string _path, bool _killExisting)
+{
+	// Initialise with the genesis as the last block on the longest chain.
+	m_genesisHash = BlockChain::genesis().hash;
+	m_genesisBlock = BlockChain::createGenesisBlock();
+
+	open(_path, _killExisting);
+}
+
+BlockChain::~BlockChain()
+{
+	close();
+}
+
+void BlockChain::open(std::string _path, bool _killExisting)
 {
 	if (_path.empty())
 		_path = Defaults::get()->m_dbPath;
@@ -127,10 +141,6 @@ BlockChain::BlockChain(std::string _path, bool _killExisting)
 	if (!m_extrasDB)
 		throw DatabaseAlreadyOpen();
 
-	// Initialise with the genesis as the last block on the longest chain.
-	m_genesisHash = BlockChain::genesis().hash;
-	m_genesisBlock = BlockChain::createGenesisBlock();
-
 	if (!details(m_genesisHash))
 	{
 		// Insert details of genesis block.
@@ -150,11 +160,16 @@ BlockChain::BlockChain(std::string _path, bool _killExisting)
 	cnote << "Opened blockchain DB. Latest: " << currentHash();
 }
 
-BlockChain::~BlockChain()
+void BlockChain::close()
 {
 	cnote << "Closing blockchain DB";
 	delete m_extrasDB;
 	delete m_db;
+	m_lastBlockHash = m_genesisHash;
+	m_details.clear();
+	m_blooms.clear();
+	m_traces.clear();
+	m_cache.clear();
 }
 
 template <class T, class V>
@@ -245,21 +260,23 @@ h256s BlockChain::import(bytes const& _block, OverlayDB const& _db)
 	auto newHash = BlockInfo::headerHash(_block);
 
 	// Check block doesn't already exist first!
-	if (details(newHash))
+	if (isKnown(newHash))
 	{
 		clog(BlockChainNote) << newHash << ": Not new.";
 		throw AlreadyHaveBlock();
 	}
 
 	// Work out its number as the parent's number + 1
-	auto pd = details(bi.parentHash);
-	if (!pd)
+	if (!isKnown(bi.parentHash))
 	{
 		clog(BlockChainNote) << newHash << ": Unknown parent " << bi.parentHash;
 		// We don't know the parent (yet) - discard for now. It'll get resent to us if we find out about its ancestry later on.
 		throw UnknownParent();
 	}
 
+	auto pd = details(bi.parentHash);
+	assert(pd);
+
 	// Check it's not crazy
 	if (bi.timestamp > (u256)time(0))
 	{
@@ -432,6 +449,20 @@ h256Set BlockChain::allUnclesFrom(h256 _parent) const
 	return ret;
 }
 
+bool BlockChain::isKnown(h256 _hash) const
+{
+	if (_hash == m_genesisHash)
+		return true;
+	{
+		ReadGuard l(x_cache);
+		if (m_cache.count(_hash))
+			return true;
+	}
+	string d;
+	m_db->Get(m_readOptions, ldb::Slice((char const*)&_hash, 32), &d);
+	return d.size();
+}
+
 bytes BlockChain::block(h256 _hash) const
 {
 	if (_hash == m_genesisHash)

libethereum/BlockChain.h

@@ -70,6 +70,8 @@ public:
 	BlockChain(std::string _path, bool _killExisting = false);
 	~BlockChain();
 
+	void reopen(std::string _path, bool _killExisting = false) { close(); open(_path, _killExisting); }
+
 	/// (Potentially) renders invalid existing bytesConstRef returned by lastBlock.
 	/// To be called from main loop every 100ms or so.
 	void process();
@@ -85,6 +87,9 @@ public:
 	/// @returns the block hashes of any blocks that came into/went out of the canonical block chain.
 	h256s import(bytes const& _block, OverlayDB const& _stateDB);
 
+	/// Returns true if the given block is known (though not necessarily a part of the canon chain).
+	bool isKnown(h256 _hash) const;
+
 	/// Get the familial details concerning a block (or the most recent mined if none given). Thread-safe.
 	BlockDetails details(h256 _hash) const { return queryExtras<BlockDetails, 0>(_hash, m_details, x_details, NullBlockDetails); }
 	BlockDetails details() const { return details(currentHash()); }
@@ -143,6 +148,9 @@ public:
 	h256s treeRoute(h256 _from, h256 _to, h256* o_common = nullptr, bool _pre = true, bool _post = true) const;
 
 private:
+	void open(std::string _path, bool _killExisting = false);
+	void close();
+
 	template<class T, unsigned N> T queryExtras(h256 _h, std::map<h256, T>& _m, boost::shared_mutex& _x, T const& _n) const
 	{
 		{

libethereum/BlockQueue.cpp

@@ -74,21 +74,24 @@ bool BlockQueue::import(bytesConstRef _block, BlockChain const& _bc)
 
 	// Check it's not in the future
 	if (bi.timestamp > (u256)time(0))
+	{
 		m_future.insert(make_pair((unsigned)bi.timestamp, _block.toBytes()));
+		cblockq << "OK - queued for future.";
+	}
 	else
 	{
 		// We now know it.
-		if (!m_readySet.count(bi.parentHash) && !m_drainingSet.count(bi.parentHash) && !_bc.details(bi.parentHash))
+		if (!m_readySet.count(bi.parentHash) && !m_drainingSet.count(bi.parentHash) && !_bc.isKnown(bi.parentHash))
 		{
 			// We don't know the parent (yet) - queue it up for later. It'll get resent to us if we find out about its ancestry later on.
-//			cnote << "OK - queued for future.";
+			cblockq << "OK - queued as unknown parent:" << bi.parentHash.abridged();
 			m_unknown.insert(make_pair(bi.parentHash, make_pair(h, _block.toBytes())));
 			m_unknownSet.insert(h);
 		}
 		else
 		{
 			// If valid, append to blocks.
-//			cnote << "OK - ready for chain insertion.";
+			cblockq << "OK - ready for chain insertion.";
 			m_ready.push_back(_block.toBytes());
 			m_readySet.insert(h);
 

libethereum/BlockQueue.h

@@ -34,7 +34,7 @@ namespace eth
 
 class BlockChain;
 
-struct BlockQueueChannel: public LogChannel { static const char* name() { return "[]Q"; } static const int verbosity = 7; };
+struct BlockQueueChannel: public LogChannel { static const char* name() { return "[]Q"; } static const int verbosity = 4; };
 #define cblockq dev::LogOutputStream<dev::eth::BlockQueueChannel, true>()
 
 /**
@@ -64,6 +64,9 @@ public:
 	/// Get information on the items queued.
 	std::pair<unsigned, unsigned> items() const { ReadGuard l(m_lock); return std::make_pair(m_ready.size(), m_unknown.size()); }
 
+	/// Clear everything.
+	void clear() { WriteGuard l(m_lock); m_readySet.clear(); m_drainingSet.clear(); m_ready.clear(); m_unknownSet.clear(); m_unknown.clear(); m_future.clear(); }
+
 private:
 	void noteReadyWithoutWriteGuard(h256 _b);
 	void notePresentWithoutWriteGuard(bytesConstRef _block);

libethereum/Client.cpp

@@ -99,7 +99,35 @@ void Client::flushTransactions()
 
 void Client::killChain()
 {
-	// TODO
+	bool wasMining = isMining();
+	if (wasMining)
+		stopMining();
+	stopWorking();
+
+	m_tq.clear();
+	m_bq.clear();
+	m_miners.clear();
+	m_preMine = State();
+	m_postMine = State();
+
+	{
+		WriteGuard l(x_stateDB);
+		m_stateDB = OverlayDB();
+		m_stateDB = State::openDB(Defaults::dbPath(), true);
+	}
+	m_bc.reopen(Defaults::dbPath(), true);
+
+	m_preMine = State(Address(), m_stateDB);
+	m_postMine = State(Address(), m_stateDB);
+
+	if (auto h = m_host.lock())
+		h->reset();
+
+	doWork();
+
+	startWorking();
+	if (wasMining)
+		startMining();
 }
 
 void Client::clearPending()

libethereum/Client.h

@@ -271,13 +271,13 @@ private:
 	BlockChain m_bc;						///< Maintains block database.
 	TransactionQueue m_tq;					///< Maintains a list of incoming transactions not yet in a block on the blockchain.
 	BlockQueue m_bq;						///< Maintains a list of incoming blocks not yet on the blockchain (to be imported).
-	// TODO: remove in favour of copying m_stateDB as required and thread-safing/copying State. Have a good think about what state objects there should be. Probably want 4 (pre, post, mining, user-visible).
+
 	mutable boost::shared_mutex x_stateDB;	///< Lock on the state DB, effectively a lock on m_postMine.
 	OverlayDB m_stateDB;					///< Acts as the central point for the state database, so multiple States can share it.
 	State m_preMine;						///< The present state of the client.
 	State m_postMine;						///< The state of the client which we're mining (i.e. it'll have all the rewards added).
 
-	std::weak_ptr<EthereumHost> m_host;	///< Our Ethereum Host. Don't do anything if we can't lock.
+	std::weak_ptr<EthereumHost> m_host;		///< Our Ethereum Host. Don't do anything if we can't lock.
 
 	std::vector<Miner> m_miners;
 	mutable boost::shared_mutex x_miners;

libethereum/CommonNet.h

@@ -33,11 +33,17 @@ namespace dev
 namespace eth
 {
 
+#if ETH_DEBUG
+static const unsigned c_maxHashes = 4;		///< Maximum number of hashes BlockHashes will ever send.
+static const unsigned c_maxHashesAsk = 4;		///< Maximum number of hashes GetBlockHashes will ever ask for.
+static const unsigned c_maxBlocks = 2;		///< Maximum number of blocks Blocks will ever send.
+static const unsigned c_maxBlocksAsk = 2;		///< Maximum number of blocks we ask to receive in Blocks (when using GetChain).
+#else
 static const unsigned c_maxHashes = 256;		///< Maximum number of hashes BlockHashes will ever send.
 static const unsigned c_maxHashesAsk = 256;		///< Maximum number of hashes GetBlockHashes will ever ask for.
 static const unsigned c_maxBlocks = 128;		///< Maximum number of blocks Blocks will ever send.
 static const unsigned c_maxBlocksAsk = 128;		///< Maximum number of blocks we ask to receive in Blocks (when using GetChain).
-
+#endif
 class OverlayDB;
 class BlockChain;
 class TransactionQueue;
@@ -55,5 +61,13 @@ enum EthereumPacket
 	BlocksPacket,
 };
 
+enum class Grabbing
+{
+	State,
+	Hashes,
+	Chain,
+	Nothing
+};
+
 }
 }

libethereum/EthereumHost.cpp

@@ -41,7 +41,7 @@ using namespace p2p;
 
 EthereumHost::EthereumHost(BlockChain const& _ch, TransactionQueue& _tq, BlockQueue& _bq, u256 _networkId):
 	HostCapability<EthereumPeer>(),
-	Worker("ethsync"),
+	Worker		("ethsync"),
 	m_chain		(_ch),
 	m_tq		(_tq),
 	m_bq		(_bq),
@@ -72,11 +72,11 @@ h256Set EthereumHost::neededBlocks(h256Set const& _exclude)
 				m_blocksNeeded.erase(it);
 			}
 	}
-	if (!ret.size())
+	if (ret.empty())
 		for (auto i = m_blocksOnWay.begin(); ret.size() < c_maxBlocksAsk && i != m_blocksOnWay.end() && !_exclude.count(*i); ++i)
 			ret.insert(*i);
-
-	clog(NetMessageSummary) << "Asking for" << ret.size() << "blocks that we don't yet have." << m_blocksNeeded.size() << "blocks still needed," << m_blocksOnWay.size() << "blocks on way.";
+	if (ret.size())
+		clog(NetMessageSummary) << "Asking for" << ret.size() << "blocks that we don't yet have." << m_blocksNeeded.size() << "blocks still needed," << m_blocksOnWay.size() << "total blocks on way.";
 	return ret;
 }
 
@@ -95,6 +95,83 @@ bool EthereumHost::ensureInitialised(TransactionQueue& _tq)
 	return false;
 }
 
+void EthereumHost::noteHavePeerState(EthereumPeer* _who)
+{
+	clog(NetAllDetail) << "Have peer state.";
+
+	// if already downloading hash-chain, ignore.
+	if (m_grabbing != Grabbing::Nothing)
+	{
+		clog(NetAllDetail) << "Already downloading chain. Just set to help out.";
+		_who->restartGettingChain();
+		return;
+	}
+
+	// otherwise check to see if we should be downloading...
+	_who->tryGrabbingHashChain();
+}
+
+void EthereumHost::updateGrabbing(Grabbing _g)
+{
+	m_grabbing = _g;
+	if (_g == Grabbing::Nothing)
+		readyForSync();
+	else if (_g == Grabbing::Chain)
+		for (auto j: peers())
+			j->cap<EthereumPeer>()->restartGettingChain();
+}
+
+void EthereumHost::noteHaveChain(EthereumPeer* _from)
+{
+	auto td = _from->m_totalDifficulty;
+
+	if (_from->m_neededBlocks.empty())
+	{
+		_from->m_grabbing = Grabbing::Nothing;
+		updateGrabbing(Grabbing::Nothing);
+		return;
+	}
+
+	clog(NetNote) << "Hash-chain COMPLETE:" << _from->m_totalDifficulty << "vs" << m_chain.details().totalDifficulty << "," << m_totalDifficultyOfNeeded << ";" << _from->m_neededBlocks.size() << " blocks, ends" << _from->m_neededBlocks.back().abridged();
+
+	if ((m_totalDifficultyOfNeeded && (td < m_totalDifficultyOfNeeded || (td == m_totalDifficultyOfNeeded && m_latestBlockSent == _from->m_latestHash))) || td < m_chain.details().totalDifficulty || (td == m_chain.details().totalDifficulty && m_chain.currentHash() == _from->m_latestHash))
+	{
+		clog(NetNote) << "Difficulty of hashchain not HIGHER. Ignoring.";
+		_from->m_grabbing = Grabbing::Nothing;
+		updateGrabbing(Grabbing::Nothing);
+		return;
+	}
+
+	clog(NetNote) << "Difficulty of hashchain HIGHER. Replacing fetch queue [latest now" << _from->m_latestHash.abridged() << ", was" << m_latestBlockSent.abridged() << "]";
+
+	// Looks like it's the best yet for total difficulty. Set to download.
+	{
+		Guard l(x_blocksNeeded);
+		m_blocksNeeded = _from->m_neededBlocks;
+		m_blocksOnWay.clear();
+		m_totalDifficultyOfNeeded = td;
+		m_latestBlockSent = _from->m_latestHash;
+	}
+
+	_from->m_grabbing = Grabbing::Chain;
+	updateGrabbing(Grabbing::Chain);
+}
+
+void EthereumHost::readyForSync()
+{
+	// start grabbing next hash chain if there is one.
+	for (auto j: peers())
+	{
+		j->cap<EthereumPeer>()->tryGrabbingHashChain();
+		if (j->cap<EthereumPeer>()->m_grabbing == Grabbing::Hashes)
+		{
+			m_grabbing = Grabbing::Hashes;
+			return;
+		}
+	}
+	clog(NetNote) << "No more peers to sync with.";
+}
+
 void EthereumHost::noteDoneBlocks()
 {
 	if (m_blocksOnWay.empty())
@@ -104,7 +181,7 @@ void EthereumHost::noteDoneBlocks()
 			clog(NetNote) << "No more blocks coming. Missing" << m_blocksNeeded.size() << "blocks.";
 		else
 			clog(NetNote) << "No more blocks to get.";
-		m_latestBlockSent = m_chain.currentHash();
+		updateGrabbing(Grabbing::Nothing);
 	}
 }
 
@@ -129,6 +206,7 @@ void EthereumHost::doWork()
 	maintainBlocks(m_bq, h);
 //	return netChange;
 	// TODO: Figure out what to do with netChange.
+	(void)netChange;
 }
 
 void EthereumHost::maintainTransactions(TransactionQueue& _tq, h256 _currentHash)
@@ -175,6 +253,21 @@ void EthereumHost::maintainTransactions(TransactionQueue& _tq, h256 _currentHash
 	}
 }
 
+void EthereumHost::reset()
+{
+	m_grabbing = Grabbing::Nothing;
+
+	m_incomingTransactions.clear();
+	m_incomingBlocks.clear();
+
+	m_totalDifficultyOfNeeded = 0;
+	m_blocksNeeded.clear();
+	m_blocksOnWay.clear();
+
+	m_latestBlockSent = h256();
+	m_transactionsSent.clear();
+}
+
 void EthereumHost::maintainBlocks(BlockQueue& _bq, h256 _currentHash)
 {
 	// Import new blocks
@@ -187,14 +280,8 @@ void EthereumHost::maintainBlocks(BlockQueue& _bq, h256 _currentHash)
 		m_incomingBlocks.clear();
 	}
 
-	// If we've finished our initial sync...
-	{
-		Guard l(x_blocksNeeded);
-		if (m_blocksOnWay.size())
-			return;
-	}
-	// ...send any new blocks.
-	if (m_latestBlockSent != _currentHash)
+	// If we've finished our initial sync send any new blocks.
+	if (m_grabbing == Grabbing::Nothing && m_chain.details(m_latestBlockSent) && m_chain.details(m_latestBlockSent).totalDifficulty < m_chain.details(_currentHash).totalDifficulty)
 	{
 		RLPStream ts;
 		EthereumPeer::prep(ts);
@@ -222,32 +309,3 @@ void EthereumHost::maintainBlocks(BlockQueue& _bq, h256 _currentHash)
 		m_latestBlockSent = _currentHash;
 	}
 }
-
-void EthereumHost::noteHaveChain(EthereumPeer* _from)
-{
-	auto td = _from->m_totalDifficulty;
-
-	if (_from->m_neededBlocks.empty())
-		return;
-
-	clog(NetNote) << "Hash-chain COMPLETE:" << _from->m_totalDifficulty << "vs" << m_chain.details().totalDifficulty << "," << m_totalDifficultyOfNeeded << ";" << _from->m_neededBlocks.size() << " blocks, ends" << _from->m_neededBlocks.back().abridged();
-
-	if ((m_totalDifficultyOfNeeded && td < m_totalDifficultyOfNeeded) || td < m_chain.details().totalDifficulty)
-	{
-		clog(NetNote) << "Difficulty of hashchain LOWER. Ignoring.";
-		return;
-	}
-
-	clog(NetNote) << "Difficulty of hashchain HIGHER. Replacing fetch queue.";
-
-	// Looks like it's the best yet for total difficulty. Set to download.
-	{
-		Guard l(x_blocksNeeded);
-		m_blocksNeeded = _from->m_neededBlocks;
-		m_blocksOnWay.clear();
-		m_totalDifficultyOfNeeded = td;
-	}
-
-	for (auto j: peers())
-		j->cap<EthereumPeer>()->restartGettingChain();
-}

libethereum/EthereumHost.h

@@ -185,7 +185,10 @@ public:
 	u256 networkId() const { return m_networkId; }
 	void setNetworkId(u256 _n) { m_networkId = _n; }
 
+	void reset();
+
 private:
+	void noteHavePeerState(EthereumPeer* _who);
 	/// Session wants to pass us a block that we might not have.
 	/// @returns true if we didn't have it.
 	bool noteBlock(h256 _hash, bytesConstRef _data);
@@ -217,12 +220,17 @@ private:
 	virtual void onStarting() { startWorking(); }
 	virtual void onStopping() { stopWorking(); }
 
+	void readyForSync();
+	void updateGrabbing(Grabbing _g);
+
 	BlockChain const& m_chain;
 	TransactionQueue& m_tq;					///< Maintains a list of incoming transactions not yet in a block on the blockchain.
 	BlockQueue& m_bq;						///< Maintains a list of incoming blocks not yet on the blockchain (to be imported).
 
 	u256 m_networkId;
 
+	Grabbing m_grabbing = Grabbing::Nothing;
+
 	mutable std::recursive_mutex m_incomingLock;
 	std::vector<bytes> m_incomingTransactions;
 	std::vector<bytes> m_incomingBlocks;
@@ -233,7 +241,7 @@ private:
 	h256Set m_blocksOnWay;
 
 	h256 m_latestBlockSent;
-	std::set<h256> m_transactionsSent;
+	h256Set m_transactionsSent;
 };
 
 }

libethereum/EthereumPeer.cpp

@@ -73,16 +73,35 @@ void EthereumPeer::startInitialSync()
 		sealAndSend(s);
 	}
 
+	host()->noteHavePeerState(this);
+}
+
+void EthereumPeer::tryGrabbingHashChain()
+{
+	// if already done this, then ignore.
+	if (m_grabbing != Grabbing::State)
+	{
+		clogS(NetAllDetail) << "Already synced with this peer.";
+		return;
+	}
+
 	h256 c = host()->m_chain.currentHash();
 	unsigned n = host()->m_chain.number();
 	u256 td = max(host()->m_chain.details().totalDifficulty, host()->m_totalDifficultyOfNeeded);
 
-	clogS(NetAllDetail) << "Initial sync. Latest:" << c.abridged() << ", number:" << n << ", TD: max(" << host()->m_chain.details().totalDifficulty << "," << host()->m_totalDifficultyOfNeeded << ") versus " << m_totalDifficulty;
+	clogS(NetAllDetail) << "Attempt chain-grab? Latest:" << c.abridged() << ", number:" << n << ", TD: max(" << host()->m_chain.details().totalDifficulty << "," << host()->m_totalDifficultyOfNeeded << ") versus " << m_totalDifficulty;
 	if (td > m_totalDifficulty)
+	{
+		clogS(NetAllDetail) << "No. Our chain is better.";
+		m_grabbing = Grabbing::Nothing;
 		return;	// All good - we have the better chain.
+	}
 
 	// Our chain isn't better - grab theirs.
 	{
+		clogS(NetAllDetail) << "Yes. Their chain is better.";
+
+		m_grabbing = Grabbing::Hashes;
 		RLPStream s;
 		prep(s).appendList(3);
 		s << GetBlockHashesPacket << m_latestHash << c_maxHashesAsk;
@@ -94,6 +113,16 @@ void EthereumPeer::startInitialSync()
 void EthereumPeer::giveUpOnFetch()
 {
 	clogS(NetNote) << "GIVE UP FETCH; can't get" << toString(m_askedBlocks);
+
+	// a bit overkill given that the other nodes may yet have the needed blocks, but better to be safe than sorry.
+	if (m_grabbing == Grabbing::Chain)
+	{
+		m_grabbing = Grabbing::Nothing;
+		host()->updateGrabbing(Grabbing::Nothing);
+	}
+
+	// NOTE: need to notify of giving up on chain-hashes, too, altering state as necessary.
+
 	if (m_askedBlocks.size())
 	{
 		Guard l (host()->x_blocksNeeded);
@@ -157,7 +186,7 @@ bool EthereumPeer::interpret(RLP const& _r)
 		unsigned limit = _r[2].toInt<unsigned>();
 		clogS(NetMessageSummary) << "GetBlockHashes (" << limit << "entries," << later.abridged() << ")";
 
-		unsigned c = min<unsigned>(host()->m_chain.number(later), limit);
+		unsigned c = min<unsigned>(max<unsigned>(1, host()->m_chain.number(later)) - 1, limit);
 
 		RLPStream s;
 		prep(s).appendList(1 + c).append(BlockHashesPacket);
@@ -169,7 +198,13 @@ bool EthereumPeer::interpret(RLP const& _r)
 	}
 	case BlockHashesPacket:
 	{
-		clogS(NetMessageSummary) << "BlockHashes (" << dec << (_r.itemCount() - 1) << "entries)";
+		clogS(NetMessageSummary) << "BlockHashes (" << dec << (_r.itemCount() - 1) << "entries)" << (_r.itemCount() - 1 ? "" : ": NoMoreHashes");
+
+		if (m_grabbing != Grabbing::Hashes)
+		{
+			cwarn << "Peer giving us hashes when we didn't ask for them.";
+			break;
+		}
 		if (_r.itemCount() == 1)
 		{
 			host()->noteHaveChain(this);
@@ -196,7 +231,7 @@ bool EthereumPeer::interpret(RLP const& _r)
 	case GetBlocksPacket:
 	{
 		clogS(NetMessageSummary) << "GetBlocks (" << dec << (_r.itemCount() - 1) << "entries)";
-		// TODO: return the requested blocks.
+		// return the requested blocks.
 		bytes rlp;
 		unsigned n = 0;
 		for (unsigned i = 1; i < _r.itemCount() && i <= c_maxBlocks; ++i)
@@ -214,7 +249,7 @@ bool EthereumPeer::interpret(RLP const& _r)
 	}
 	case BlocksPacket:
 	{
-		clogS(NetMessageSummary) << "Blocks (" << dec << (_r.itemCount() - 1) << "entries)";
+		clogS(NetMessageSummary) << "Blocks (" << dec << (_r.itemCount() - 1) << "entries)" << (_r.itemCount() - 1 ? "" : ": NoMoreBlocks");
 
 		if (_r.itemCount() == 1 && !m_askedBlocksChanged)
 		{
@@ -302,7 +337,7 @@ void EthereumPeer::continueGettingChain()
 	else
 	{
 		if (m_failedBlocks.size())
-		clogS(NetMessageSummary) << "No blocks left to get. Peer doesn't seem to have" << m_failedBlocks.size() << "of our needed blocks.";
+			clogS(NetMessageSummary) << "No blocks left to get. Peer doesn't seem to have" << m_failedBlocks.size() << "of our needed blocks.";
 		host()->noteDoneBlocks();
 	}
 }

libethereum/EthereumPeer.h

@@ -59,6 +59,8 @@ private:
 	void sendStatus();
 	void startInitialSync();
 
+	void tryGrabbingHashChain();
+
 	/// Ensure that we are waiting for a bunch of blocks from our peer.
 	void ensureGettingChain();
 	/// Ensure that we are waiting for a bunch of blocks from our peer.
@@ -73,6 +75,8 @@ private:
 	unsigned m_protocolVersion;
 	u256 m_networkId;
 
+	Grabbing m_grabbing = Grabbing::State;
+
 	h256 m_latestHash;						///< Peer's latest block's hash.
 	u256 m_totalDifficulty;					///< Peer's latest block's total difficulty.
 	h256s m_neededBlocks;					///< The blocks that we should download from this peer.

libethereum/State.cpp

@@ -152,10 +152,15 @@ State& State::operator=(State const& _s)
 	m_currentBlock = _s.m_currentBlock;
 	m_ourAddress = _s.m_ourAddress;
 	m_blockReward = _s.m_blockReward;
+	m_lastTx = _s.m_lastTx;
 	paranoia("after state cloning (assignment op)", true);
 	return *this;
 }
 
+State::~State()
+{
+}
+
 struct CachedAddressState
 {
 	CachedAddressState(std::string const& _rlp, AddressState const* _s, OverlayDB const* _o): rS(_rlp), r(rS), s(_s), o(_o) {}

libethereum/State.h

@@ -90,6 +90,8 @@ public:
 	/// Copy state object.
 	State& operator=(State const& _s);
 
+	~State();
+
 	/// Set the coinbase address for any transactions we do.
 	/// This causes a complete reset of current block.
 	void setAddress(Address _coinbaseAddress) { m_ourAddress = _coinbaseAddress; resetCurrent(); }

libethereum/TransactionQueue.h

@@ -52,6 +52,8 @@ public:
 	void setFuture(std::pair<h256, bytes> const& _t);
 	void noteGood(std::pair<h256, bytes> const& _t);
 
+	void clear() { WriteGuard l(m_lock); m_known.clear(); m_current.clear(); m_unknown.clear(); }
+
 private:
 	mutable boost::shared_mutex m_lock;							///< General lock.
 	std::set<h256> m_known;										///< Hashes of transactions in both sets.

libwebthree/WebThree.h

@@ -106,7 +106,7 @@ public:
 
 	bool haveNetwork() const { return m_net.isStarted(); }
 
-	void setNetworkPreferences(p2p::NetworkPreferences const& _n) { auto had = haveNetwork(); if (had) stopNetwork(); m_netPrefs = _n; if (had) startNetwork(); }
+	void setNetworkPreferences(p2p::NetworkPreferences const& _n) { auto had = haveNetwork(); if (had) stopNetwork(); m_net.setNetworkPreferences(_n); if (had) startNetwork(); }
 
 	/// Start the network subsystem.
 	void startNetwork() { m_net.start(); }
@@ -121,7 +121,6 @@ private:
 	std::unique_ptr<shh::WhisperHost> m_whisper;	///< Main interface for Whisper ("shh") protocol.
 
 	p2p::Host m_net;								///< Should run in background and send us events when blocks found and allow us to send blocks as required.
-	p2p::NetworkPreferences m_netPrefs;
 };