Init and update merkle tree root

src/block_template.cpp

@@ -28,6 +28,7 @@
 #include "side_chain.h"
 #include "pool_block.h"
 #include "params.h"
+#include "merkle.h"
 #include <zmq.hpp>
 #include <ctime>
 #include <numeric>
@@ -662,11 +663,14 @@ void BlockTemplate::update(const MinerData& data, const Mempool& mempool, const
 	m_poolBlockTemplate->m_extraNonce = 0;
 	m_poolBlockTemplate->m_sidechainId = {};
 
-	// TODO: fill in merkle tree data here
-	m_poolBlockTemplate->m_merkleTreeDataSize = 1;
-	m_poolBlockTemplate->m_merkleTreeData = 0;
+	m_poolBlockTemplate->m_merkleTreeData = PoolBlock::encode_merkle_tree_data(static_cast<uint32_t>(data.aux_chains.size() + 1), data.aux_nonce);
+	m_poolBlockTemplate->m_merkleTreeDataSize = 0;
+	writeVarint(m_poolBlockTemplate->m_merkleTreeData, [this](uint8_t) { ++m_poolBlockTemplate->m_merkleTreeDataSize; });
 	m_poolBlockTemplate->m_merkleRoot = {};
 
+	m_poolBlockTemplate->m_auxChains = data.aux_chains;
+	m_poolBlockTemplate->m_auxNonce = data.aux_nonce;
+
 	const std::vector<uint8_t> sidechain_data = m_poolBlockTemplate->serialize_sidechain_data();
 	const std::vector<uint8_t>& consensus_id = m_sidechain->consensus_id();
 
@@ -697,11 +701,7 @@ void BlockTemplate::update(const MinerData& data, const Mempool& mempool, const
 	LOGINFO(6, "blob size = " << m_fullDataBlob.size());
 
 	m_poolBlockTemplate->m_sidechainId = calc_sidechain_hash(0);
-
-	// TODO: fill in merkle tree data here
-	m_poolBlockTemplate->m_merkleTreeDataSize = 1;
-	m_poolBlockTemplate->m_merkleTreeData = 0;
-	m_poolBlockTemplate->m_merkleRoot = m_poolBlockTemplate->m_sidechainId;
+	init_merge_mining_merkle_root();
 
 	if (pool_block_debug()) {
 		const size_t sidechain_hash_offset = m_extraNonceOffsetInTemplate + m_poolBlockTemplate->m_extraNonceSize + 2 + m_poolBlockTemplate->m_merkleTreeDataSize;
@@ -1312,10 +1312,10 @@ bool BlockTemplate::submit_sidechain_block(uint32_t template_id, uint32_t nonce,
 		m_poolBlockTemplate->m_sidechainId = calc_sidechain_hash(extra_nonce);
 		m_poolBlockTemplate->m_sidechainExtraBuf[3] = extra_nonce;
 
-		// TODO: fill in merkle tree data here
-		m_poolBlockTemplate->m_merkleTreeDataSize = 1;
-		m_poolBlockTemplate->m_merkleTreeData = 0;
-		m_poolBlockTemplate->m_merkleRoot = m_poolBlockTemplate->m_sidechainId;
+		const uint32_t n_aux_chains = static_cast<uint32_t>(m_poolBlockTemplate->m_auxChains.size() + 1);
+		const uint32_t aux_slot = get_aux_slot(m_sidechain->consensus_hash(), m_poolBlockTemplate->m_auxNonce, n_aux_chains);
+
+		m_poolBlockTemplate->m_merkleRoot = get_root_from_proof(m_poolBlockTemplate->m_sidechainId, m_poolBlockTemplate->m_merkleProof, aux_slot, n_aux_chains);
 
 		if (pool_block_debug()) {
 			std::vector<uint8_t> buf = m_poolBlockTemplate->serialize_mainchain_data();
@@ -1368,4 +1368,38 @@ bool BlockTemplate::submit_sidechain_block(uint32_t template_id, uint32_t nonce,
 	return false;
 }
 
+void BlockTemplate::init_merge_mining_merkle_root()
+{
+	const uint32_t n_aux_chains = static_cast<uint32_t>(m_poolBlockTemplate->m_auxChains.size() + 1);
+
+	if (n_aux_chains == 1) {
+		m_poolBlockTemplate->m_merkleRoot = m_poolBlockTemplate->m_sidechainId;
+		return;
+	}
+
+	std::vector<hash> hashes(n_aux_chains);
+
+	for (const AuxChainData& aux_data : m_poolBlockTemplate->m_auxChains) {
+		const uint32_t aux_slot = get_aux_slot(aux_data.unique_id, m_poolBlockTemplate->m_auxNonce, n_aux_chains);
+		hashes[aux_slot] = aux_data.data;
+	}
+
+	const uint32_t aux_slot = get_aux_slot(m_sidechain->consensus_hash(), m_poolBlockTemplate->m_auxNonce, n_aux_chains);
+	hashes[aux_slot] = m_poolBlockTemplate->m_sidechainId;
+
+	std::vector<std::vector<hash>> tree;
+	merkle_hash_full_tree(hashes, tree);
+	m_poolBlockTemplate->m_merkleRoot = tree.back().front();
+
+	std::vector<std::pair<bool, hash>> proof;
+	get_merkle_proof(tree, m_poolBlockTemplate->m_sidechainId, proof);
+
+	m_poolBlockTemplate->m_merkleProof.clear();
+	m_poolBlockTemplate->m_merkleProof.reserve(proof.size());
+
+	for (const auto& p : proof) {
+		m_poolBlockTemplate->m_merkleProof.push_back(p.second);
+	}
+}
+
 } // namespace p2pool

src/block_template.h

@@ -132,6 +132,8 @@ private:
 
 	std::vector<uint32_t> m_knapsack;
 #endif
+
+	void init_merge_mining_merkle_root();
 };
 
 } // namespace p2pool

src/common.h

@@ -383,6 +383,13 @@ struct TxMempoolData
 	uint64_t time_received;
 };
 
+struct AuxChainData
+{
+	hash unique_id;
+	hash data;
+	difficulty_type difficulty;
+};
+
 struct MinerData
 {
 	FORCEINLINE MinerData()
@@ -394,6 +401,7 @@ struct MinerData
 		, median_weight(0)
 		, already_generated_coins(0)
 		, median_timestamp(0)
+		, aux_nonce(0)
 	{}
 
 	uint8_t major_version;
@@ -406,6 +414,9 @@ struct MinerData
 	uint64_t median_timestamp;
 	std::vector<TxMempoolData> tx_backlog;
 
+	std::vector<AuxChainData> aux_chains;
+	uint32_t aux_nonce;
+
 	std::chrono::high_resolution_clock::time_point time_received;
 };
 

src/merkle.cpp

@@ -194,10 +194,10 @@ bool verify_merkle_proof(hash h, const std::vector<std::pair<bool, hash>>& proof
 	return (h == root);
 }
 
-bool verify_merkle_proof(hash h, const std::vector<hash>& proof, size_t index, size_t count, const hash& root)
+hash get_root_from_proof(hash h, const std::vector<hash>& proof, size_t index, size_t count)
 {
 	if (index >= count) {
-		return false;
+		return hash();
 	}
 
 	hash tmp[2];
@@ -206,7 +206,7 @@ bool verify_merkle_proof(hash h, const std::vector<hash>& proof, size_t index, s
 	}
 	else if (count == 2) {
 		if (proof.empty()) {
-			return false;
+			return hash();
 		}
 
 		if (index & 1) {
@@ -233,7 +233,7 @@ bool verify_merkle_proof(hash h, const std::vector<hash>& proof, size_t index, s
 			index -= k;
 
 			if (proof.empty()) {
-				return false;
+				return hash();
 			}
 
 			if (index & 1) {
@@ -253,7 +253,7 @@ bool verify_merkle_proof(hash h, const std::vector<hash>& proof, size_t index, s
 
 		for (; cnt >= 2; ++proof_index, index >>= 1, cnt >>= 1) {
 			if (proof_index >= proof.size()) {
-				return false;
+				return hash();
 			}
 
 			if (index & 1) {
@@ -269,7 +269,12 @@ bool verify_merkle_proof(hash h, const std::vector<hash>& proof, size_t index, s
 		}
 	}
 
-	return (h == root);
+	return h;
+}
+
+bool verify_merkle_proof(hash h, const std::vector<hash>& proof, size_t index, size_t count, const hash& root)
+{
+	return get_root_from_proof(h, proof, index, count) == root;
 }
 
 uint32_t get_aux_slot(const hash &id, uint32_t nonce, uint32_t n_aux_chains)
@@ -292,4 +297,38 @@ uint32_t get_aux_slot(const hash &id, uint32_t nonce, uint32_t n_aux_chains)
 	return *reinterpret_cast<uint32_t*>(res.h) % n_aux_chains;
 }
 
+bool find_aux_nonce(const std::vector<hash>& aux_id, uint32_t& nonce, uint32_t max_nonce)
+{
+	const uint32_t n_aux_chains = static_cast<uint32_t>(aux_id.size());
+
+	if (n_aux_chains <= 1) {
+		nonce = 0;
+		return true;
+	}
+
+	std::vector<bool> slots;
+
+	for (uint32_t i = 0;; ++i) {
+		slots.assign(n_aux_chains, false);
+
+		uint32_t j;
+		for (j = 0; j < n_aux_chains; ++j) {
+			const uint32_t k = get_aux_slot(aux_id[j], i, n_aux_chains);
+			if (slots[k]) {
+				break;
+			}
+			slots[k] = true;
+		}
+
+		if (j >= n_aux_chains) {
+			nonce = i;
+			return true;
+		}
+
+		if (i == max_nonce) {
+			return false;
+		}
+	}
+}
+
 } // namespace p2pool

src/merkle.h

@@ -24,8 +24,11 @@ void merkle_hash_full_tree(const std::vector<hash>& hashes, std::vector<std::vec
 
 bool get_merkle_proof(const std::vector<std::vector<hash>>& tree, const hash& h, std::vector<std::pair<bool, hash>>& proof);
 bool verify_merkle_proof(hash h, const std::vector<std::pair<bool, hash>>& proof, const hash& root);
+
+hash get_root_from_proof(hash h, const std::vector<hash>& proof, size_t index, size_t count);
 bool verify_merkle_proof(hash h, const std::vector<hash>& proof, size_t index, size_t count, const hash& root);
 
 uint32_t get_aux_slot(const hash &id, uint32_t nonce, uint32_t n_aux_chains);
+bool find_aux_nonce(const std::vector<hash>& aux_id, uint32_t& nonce, uint32_t max_nonce = 0xFFFF);
 
 } // namespace p2pool

src/pool_block.cpp

@@ -58,6 +58,7 @@ PoolBlock::PoolBlock()
 	, m_precalculated(false)
 	, m_localTimestamp(seconds_since_epoch())
 	, m_receivedTimestamp(0)
+	, m_auxNonce(0)
 {
 }
 
@@ -113,6 +114,9 @@ PoolBlock& PoolBlock::operator=(const PoolBlock& b)
 	m_localTimestamp = seconds_since_epoch();
 	m_receivedTimestamp = b.m_receivedTimestamp;
 
+	m_auxChains = b.m_auxChains;
+	m_auxNonce = b.m_auxNonce;
+
 	return *this;
 }
 
@@ -286,6 +290,11 @@ void PoolBlock::reset_offchain_data()
 
 	m_localTimestamp = seconds_since_epoch();
 	m_receivedTimestamp = 0;
+
+	m_auxChains.clear();
+	m_auxChains.shrink_to_fit();
+
+	m_auxNonce = 0;
 }
 
 bool PoolBlock::get_pow_hash(RandomX_Hasher_Base* hasher, uint64_t height, const hash& seed_hash, hash& pow_hash, bool force_light_mode)

src/pool_block.h

@@ -148,6 +148,9 @@ struct PoolBlock
 	uint64_t m_localTimestamp;
 	uint64_t m_receivedTimestamp;
 
+	std::vector<AuxChainData> m_auxChains;
+	uint32_t m_auxNonce;
+
 	std::vector<uint8_t> serialize_mainchain_data(size_t* header_size = nullptr, size_t* miner_tx_size = nullptr, int* outputs_offset = nullptr, int* outputs_blob_size = nullptr, const uint32_t* nonce = nullptr, const uint32_t* extra_nonce = nullptr) const;
 	std::vector<uint8_t> serialize_sidechain_data() const;
 
@@ -176,6 +179,15 @@ struct PoolBlock
 
 	hash calculate_tx_key_seed() const;
 
+	static FORCEINLINE uint64_t encode_merkle_tree_data(uint32_t n_aux_chains, uint32_t nonce)
+	{
+		uint32_t n_bits = 1U;
+		while (((1U << n_bits) < n_aux_chains) && (n_bits < 8)) {
+			++n_bits;
+		}
+		return (n_bits - 1U) | ((n_aux_chains - 1U) << 3U) | (static_cast<uint64_t>(nonce) << (3U + n_bits));
+	}
+
 	FORCEINLINE void decode_merkle_tree_data(uint32_t& mm_n_aux_chains, uint32_t& mm_nonce) const
 	{
 		const uint32_t k = static_cast<uint32_t>(m_merkleTreeData);

tests/src/merkle_tests.cpp

@@ -243,4 +243,34 @@ TEST(merkle, aux_slot)
 	ASSERT_EQ(get_aux_slot(id, 1, std::numeric_limits<uint32_t>::max()), 1080669337U);
 }
 
+TEST(merkle, aux_nonce)
+{
+	std::vector<hash> aux_id;
+	uint32_t nonce;
+
+	ASSERT_TRUE(find_aux_nonce(aux_id, nonce));
+	ASSERT_EQ(nonce, 0);
+
+	uint8_t data[] = "aux0";
+
+	const uint32_t nonces[] = { 0, 0, 0, 7, 16, 56, 1, 287, 1423, 1074 };
+	hash h;
+
+	for (size_t i = 0; i < 10; ++i, ++data[sizeof(data) - 2]) {
+		keccak(data, sizeof(data) - 1, h.h);
+		aux_id.push_back(h);
+
+		ASSERT_TRUE(find_aux_nonce(aux_id, nonce));
+		ASSERT_EQ(nonce, nonces[i]);
+	}
+
+	h = aux_id.front();
+
+	aux_id.clear();
+	aux_id.push_back(h);
+	aux_id.push_back(h);
+
+	ASSERT_FALSE(find_aux_nonce(aux_id, nonce));
+}
+
 }