merge bitcoin#17693: Add generateblock to mine a custom set of transactions

src/rpc/client.cpp

@@ -35,6 +35,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "generatetoaddress", 2, "maxtries" },
     { "generatetodescriptor", 0, "num_blocks" },
     { "generatetodescriptor", 2, "maxtries" },
+    { "generateblock", 1, "transactions" },
 #endif // ENABLE_MINER
     { "getnetworkhashps", 0, "nblocks" },
     { "getnetworkhashps", 1, "height" },

src/rpc/mining.cpp

@@ -108,6 +108,36 @@ static UniValue getnetworkhashps(const JSONRPCRequest& request)
 }
 
 #if ENABLE_MINER
+static bool GenerateBlock(CBlock& block, uint64_t& max_tries, unsigned int& extra_nonce, uint256& block_hash)
+{
+    block_hash.SetNull();
+
+    {
+        LOCK(cs_main);
+        IncrementExtraNonce(&block, ::ChainActive().Tip(), extra_nonce);
+    }
+
+    CChainParams chainparams(Params());
+
+    while (max_tries > 0 && block.nNonce < std::numeric_limits<uint32_t>::max() && !CheckProofOfWork(block.GetHash(), block.nBits, chainparams.GetConsensus()) && !ShutdownRequested()) {
+        ++block.nNonce;
+        --max_tries;
+    }
+    if (max_tries == 0 || ShutdownRequested()) {
+        return false;
+    }
+    if (block.nNonce == std::numeric_limits<uint32_t>::max()) {
+        return true;
+    }
+
+    std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(block);
+    if (!ProcessNewBlock(chainparams, shared_pblock, true, nullptr))
+        throw JSONRPCError(RPC_INTERNAL_ERROR, "ProcessNewBlock, block not accepted");
+
+    block_hash = block.GetHash();
+    return true;
+}
+
 UniValue generateBlocks(const CTxMemPool& mempool, std::shared_ptr<CReserveScript> coinbaseScript, int nGenerate, uint64_t nMaxTries, bool keepScript)
 {
     int nHeightEnd = 0;
@@ -126,29 +156,19 @@ UniValue generateBlocks(const CTxMemPool& mempool, std::shared_ptr<CReserveScrip
         if (!pblocktemplate.get())
             throw JSONRPCError(RPC_INTERNAL_ERROR, "Couldn't create new block");
         CBlock *pblock = &pblocktemplate->block;
-        {
-            LOCK(cs_main);
-            IncrementExtraNonce(pblock, ::ChainActive().Tip(), nExtraNonce);
-        }
-        while (nMaxTries > 0 && pblock->nNonce < std::numeric_limits<uint32_t>::max() && !CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus()) && !ShutdownRequested()) {
-            ++pblock->nNonce;
-            --nMaxTries;
-        }
-        if (nMaxTries == 0 || ShutdownRequested()) {
+
+        uint256 block_hash;
+        if (!GenerateBlock(*pblock, nMaxTries, nExtraNonce, block_hash)) {
             break;
         }
-        if (pblock->nNonce == std::numeric_limits<uint32_t>::max()) {
-            continue;
-        }
-        std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(*pblock);
-        if (!ProcessNewBlock(Params(), shared_pblock, true, nullptr))
-            throw JSONRPCError(RPC_INTERNAL_ERROR, "ProcessNewBlock, block not accepted");
-        ++nHeight;
-        blockHashes.push_back(pblock->GetHash().GetHex());
 
-        //mark script as important because it was used at least for one coinbase output if the script came from the wallet
-        if (keepScript)
-        {
+        if (!block_hash.IsNull()) {
+            ++nHeight;
+            blockHashes.push_back(block_hash.GetHex());
+        }
+
+        // mark script as important because it was used at least for one coinbase output if the script came from the wallet
+        if (keepScript) {
             LOCK(cs_main);
             coinbaseScript->KeepScript();
         }
@@ -156,6 +176,40 @@ UniValue generateBlocks(const CTxMemPool& mempool, std::shared_ptr<CReserveScrip
     return blockHashes;
 }
 
+static bool getScriptFromDescriptor(const std::string& descriptor, CScript& script, std::string& error)
+{
+    FlatSigningProvider key_provider;
+    const auto desc = Parse(descriptor, key_provider, error, /* require_checksum = */ false);
+    if (desc) {
+        if (desc->IsRange()) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Ranged descriptor not accepted. Maybe pass through deriveaddresses first?");
+        }
+
+        FlatSigningProvider provider;
+        std::vector<CScript> scripts;
+        if (!desc->Expand(0, key_provider, scripts, provider)) {
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Cannot derive script without private keys"));
+        }
+
+        // Combo desriptors can have 2 or 4 scripts, so we can't just check scripts.size() == 1
+        CHECK_NONFATAL(scripts.size() > 0 && scripts.size() <= 4);
+
+        if (scripts.size() == 1) {
+            script = scripts.at(0);
+        } else if (scripts.size() == 4) {
+            // For uncompressed keys, take the 3rd script, since it is p2wpkh
+            script = scripts.at(2);
+        } else {
+            // Else take the 2nd script, since it is p2pkh
+            script = scripts.at(1);
+        }
+
+        return true;
+    } else {
+        return false;
+    }
+}
+
 static UniValue generatetodescriptor(const JSONRPCRequest& request)
 {
     RPCHelpMan{
@@ -176,28 +230,16 @@ static UniValue generatetodescriptor(const JSONRPCRequest& request)
     const int num_blocks{request.params[0].get_int()};
     const int64_t max_tries{request.params[2].isNull() ? 1000000 : request.params[2].get_int()};
 
-    FlatSigningProvider key_provider;
+    CScript coinbase_script;
     std::string error;
-    const auto desc = Parse(request.params[1].get_str(), key_provider, error, /* require_checksum = */ false);
-    if (!desc) {
+    if (!getScriptFromDescriptor(request.params[1].get_str(), coinbase_script, error)) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, error);
     }
-    if (desc->IsRange()) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Ranged descriptor not accepted. Maybe pass through deriveaddresses first?");
-    }
-
-    FlatSigningProvider provider;
-    std::vector<CScript> coinbase_script;
-    if (!desc->Expand(0, key_provider, coinbase_script, provider)) {
-        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Cannot derive script without private keys"));
-    }
 
     const CTxMemPool& mempool = EnsureMemPool();
 
-    CHECK_NONFATAL(coinbase_script.size() == 1);
-
     std::shared_ptr<CReserveScript> coinbaseScript = std::make_shared<CReserveScript>();
-    coinbaseScript->reserveScript = coinbase_script.at(0);
+    coinbaseScript->reserveScript = coinbase_script;
 
     return generateBlocks(mempool, coinbaseScript, num_blocks, max_tries, false);
 }
@@ -242,6 +284,112 @@ static UniValue generatetoaddress(const JSONRPCRequest& request)
 
     return generateBlocks(mempool, coinbaseScript, nGenerate, nMaxTries, false);
 }
+
+static UniValue generateblock(const JSONRPCRequest& request)
+{
+    RPCHelpMan{"generateblock",
+        "\nMine a block with a set of ordered transactions immediately to a specified address or descriptor (before the RPC call returns)\n",
+        {
+            {"address/descriptor", RPCArg::Type::STR, RPCArg::Optional::NO, "The address or descriptor to send the newly generated bitcoin to."},
+            {"transactions", RPCArg::Type::ARR, RPCArg::Optional::NO, "An array of hex strings which are either txids or raw transactions.\n"
+                "Txids must reference transactions currently in the mempool.\n"
+                "All transactions must be valid and in valid order, otherwise the block will be rejected.",
+                {
+                    {"rawtx/txid", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, ""},
+                },
+            }
+        },
+        RPCResult{
+            RPCResult::Type::OBJ, "", "",
+            {
+                {RPCResult::Type::STR_HEX, "hash", "hash of generated block"}
+            }
+        },
+        RPCExamples{
+            "\nGenerate a block to myaddress, with txs rawtx and mempool_txid\n"
+            + HelpExampleCli("generateblock", R"("myaddress" '["rawtx", "mempool_txid"]')")
+        },
+    }.Check(request);
+
+    const auto address_or_descriptor = request.params[0].get_str();
+    CScript coinbase_script;
+    std::string error;
+
+    if (!getScriptFromDescriptor(address_or_descriptor, coinbase_script, error)) {
+        const auto destination = DecodeDestination(address_or_descriptor);
+        if (!IsValidDestination(destination)) {
+            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Error: Invalid address or descriptor");
+        }
+
+        coinbase_script = GetScriptForDestination(destination);
+    }
+
+    const CTxMemPool& mempool = EnsureMemPool();
+
+    std::vector<CTransactionRef> txs;
+    const auto raw_txs_or_txids = request.params[1].get_array();
+    for (size_t i = 0; i < raw_txs_or_txids.size(); i++) {
+        const auto str(raw_txs_or_txids[i].get_str());
+
+        uint256 hash;
+        CMutableTransaction mtx;
+        if (ParseHashStr(str, hash)) {
+
+            const auto tx = mempool.get(hash);
+            if (!tx) {
+                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Transaction %s not in mempool.", str));
+            }
+
+            txs.emplace_back(tx);
+
+        } else if (DecodeHexTx(mtx, str)) {
+            txs.push_back(MakeTransactionRef(std::move(mtx)));
+
+        } else {
+            throw JSONRPCError(RPC_DESERIALIZATION_ERROR, strprintf("Transaction decode failed for %s", str));
+        }
+    }
+
+    CChainParams chainparams(Params());
+    CBlock block;
+
+    {
+        LOCK(cs_main);
+
+        CTxMemPool empty_mempool;
+        std::unique_ptr<CBlockTemplate> blocktemplate(BlockAssembler(empty_mempool, chainparams).CreateNewBlock(coinbase_script));
+        if (!blocktemplate) {
+            throw JSONRPCError(RPC_INTERNAL_ERROR, "Couldn't create new block");
+        }
+        block = blocktemplate->block;
+    }
+
+    CHECK_NONFATAL(block.vtx.size() == 1);
+
+    // Add transactions
+    block.vtx.insert(block.vtx.end(), txs.begin(), txs.end());
+
+    {
+        LOCK(cs_main);
+
+        CValidationState state;
+        if (!TestBlockValidity(state, chainparams, block, LookupBlockIndex(block.hashPrevBlock), false, false)) {
+            throw JSONRPCError(RPC_VERIFY_ERROR, strprintf("TestBlockValidity failed: %s", state.GetRejectReason()));
+        }
+    }
+
+    uint256 block_hash;
+    uint64_t max_tries{1000000};
+    unsigned int extra_nonce{0};
+
+    if (!GenerateBlock(block, max_tries, extra_nonce, block_hash) || block_hash.IsNull()) {
+        throw JSONRPCError(RPC_MISC_ERROR, "Failed to make block.");
+    }
+
+    UniValue obj(UniValue::VOBJ);
+    obj.pushKV("hash", block_hash.GetHex());
+    return obj;
+}
 #else
 static UniValue generatetoaddress(const JSONRPCRequest& request)
 {
@@ -251,6 +399,10 @@ static UniValue generatetodescriptor(const JSONRPCRequest& request)
 {
     throw JSONRPCError(RPC_METHOD_NOT_FOUND, "This call is not available because RPC miner isn't compiled");
 }
+static UniValue generateblock(const JSONRPCRequest& request)
+{
+    throw JSONRPCError(RPC_METHOD_NOT_FOUND, "This call is not available because RPC miner isn't compiled");
+}
 #endif // ENABLE_MINER
 
 static UniValue getmininginfo(const JSONRPCRequest& request)
@@ -1066,9 +1218,11 @@ static const CRPCCommand commands[] =
 #if ENABLE_MINER
     { "generating",         "generatetoaddress",      &generatetoaddress,      {"nblocks","address","maxtries"} },
     { "generating",         "generatetodescriptor",   &generatetodescriptor,   {"num_blocks","descriptor","maxtries"} },
+    { "generating",         "generateblock",          &generateblock,          {"address","transactions"} },
 #else
     { "hidden",             "generatetoaddress",      &generatetoaddress,      {"nblocks","address","maxtries"} }, // Hidden as it isn't functional, just an error to let people know if miner isn't compiled
     { "hidden",             "generatetodescriptor",   &generatetodescriptor,   {"num_blocks","descriptor","maxtries"} },
+    { "hidden",             "generateblock",          &generateblock,          {"address","transactions"} },
 #endif // ENABLE_MINER
 
     { "util",               "estimatesmartfee",       &estimatesmartfee,       {"conf_target", "estimate_mode"} },

test/functional/rpc_generateblock.py

@@ -0,0 +1,97 @@
+#!/usr/bin/env python3
+# Copyright (c) 2020 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+'''Test generateblock rpc.
+'''
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import (
+    assert_equal,
+    assert_raises_rpc_error,
+)
+
+class GenerateBlockTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 1
+
+    def skip_test_if_missing_module(self):
+        self.skip_if_no_wallet()
+
+    def run_test(self):
+        node = self.nodes[0]
+
+        self.log.info('Generate an empty block to address')
+        address = node.getnewaddress()
+        hash = node.generateblock(address, [])['hash']
+        block = node.getblock(hash, 2)
+        assert_equal(len(block['tx']), 1)
+        assert_equal(block['tx'][0]['vout'][0]['scriptPubKey']['addresses'][0], address)
+
+        self.log.info('Generate an empty block to a descriptor')
+        hash = node.generateblock('addr(' + address + ')', [])['hash']
+        block = node.getblock(hash, 2)
+        assert_equal(len(block['tx']), 1)
+        assert_equal(block['tx'][0]['vout'][0]['scriptPubKey']['addresses'][0], address)
+
+        self.log.info('Generate an empty block to a combo descriptor with compressed pubkey')
+        combo_key = '0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798'
+        combo_address = 'yWziQMcwmKjRdzi7eWjwiQX8EjWcd6dSg6'
+        hash = node.generateblock('combo(' + combo_key + ')', [])['hash']
+        block = node.getblock(hash, 2)
+        assert_equal(len(block['tx']), 1)
+        assert_equal(block['tx'][0]['vout'][0]['scriptPubKey']['addresses'][0], combo_address)
+
+        # Generate 110 blocks to spend
+        node.generatetoaddress(110, address)
+
+        # Generate some extra mempool transactions to verify they don't get mined
+        for i in range(10):
+            node.sendtoaddress(address, 0.001)
+
+        self.log.info('Generate block with txid')
+        txid = node.sendtoaddress(address, 1)
+        hash = node.generateblock(address, [txid])['hash']
+        block = node.getblock(hash, 1)
+        assert_equal(len(block['tx']), 2)
+        assert_equal(block['tx'][1], txid)
+
+        self.log.info('Generate block with raw tx')
+        utxos = node.listunspent(addresses=[address])
+        raw = node.createrawtransaction([{'txid':utxos[0]['txid'], 'vout':utxos[0]['vout']}],[{address:1}])
+        signed_raw = node.signrawtransactionwithwallet(raw)['hex']
+        hash = node.generateblock(address, [signed_raw])['hash']
+        block = node.getblock(hash, 1)
+        assert_equal(len(block['tx']), 2)
+        txid = block['tx'][1]
+        assert_equal(node.gettransaction(txid)['hex'], signed_raw)
+
+        self.log.info('Fail to generate block with out of order txs')
+        raw1 = node.createrawtransaction([{'txid':txid, 'vout':0}],[{address:0.9999}])
+        signed_raw1 = node.signrawtransactionwithwallet(raw1)['hex']
+        txid1 = node.sendrawtransaction(signed_raw1)
+        raw2 = node.createrawtransaction([{'txid':txid1, 'vout':0}],[{address:0.999}])
+        signed_raw2 = node.signrawtransactionwithwallet(raw2)['hex']
+        assert_raises_rpc_error(-25, 'TestBlockValidity failed: bad-txns-inputs-missingorspent', node.generateblock, address, [signed_raw2, txid1])
+
+        self.log.info('Fail to generate block with txid not in mempool')
+        missing_txid = '0000000000000000000000000000000000000000000000000000000000000000'
+        assert_raises_rpc_error(-5, 'Transaction ' + missing_txid + ' not in mempool.', node.generateblock, address, [missing_txid])
+
+        self.log.info('Fail to generate block with invalid raw tx')
+        invalid_raw_tx = '0000'
+        assert_raises_rpc_error(-22, 'Transaction decode failed for ' + invalid_raw_tx, node.generateblock, address, [invalid_raw_tx])
+
+        self.log.info('Fail to generate block with invalid address/descriptor')
+        assert_raises_rpc_error(-5, 'Invalid address or descriptor', node.generateblock, '1234', [])
+
+        self.log.info('Fail to generate block with a ranged descriptor')
+        ranged_descriptor = 'pkh(tpubD6NzVbkrYhZ4XgiXtGrdW5XDAPFCL9h7we1vwNCpn8tGbBcgfVYjXyhWo4E1xkh56hjod1RhGjxbaTLV3X4FyWuejifB9jusQ46QzG87VKp/0/*)'
+        assert_raises_rpc_error(-8, 'Ranged descriptor not accepted. Maybe pass through deriveaddresses first?', node.generateblock, ranged_descriptor, [])
+
+        self.log.info('Fail to generate block with a descriptor missing a private key')
+        child_descriptor = 'pkh(tpubD6NzVbkrYhZ4XgiXtGrdW5XDAPFCL9h7we1vwNCpn8tGbBcgfVYjXyhWo4E1xkh56hjod1RhGjxbaTLV3X4FyWuejifB9jusQ46QzG87VKp/0\'/0)'
+        assert_raises_rpc_error(-5, 'Cannot derive script without private keys', node.generateblock, child_descriptor, [])
+
+if __name__ == '__main__':
+    GenerateBlockTest().main()

test/functional/test_runner.py

@@ -183,6 +183,7 @@ BASE_SCRIPTS = [
     'wallet_importprunedfunds.py',
     'p2p_leak_tx.py',
     'rpc_signmessage.py',
+    'rpc_generateblock.py',
     'wallet_balance.py',
     'feature_nulldummy.py',
     'mempool_accept.py',