Merge pull request #1546 from rnicoll/1.17-auxpow1.17-dev

1.17 AuxPoW support

5 files changed, 381 insertions, 10 deletions

diff --git a/src/rpc/auxpow_miner.cpp b/src/rpc/auxpow_miner.cpp
new file mode 100644
index 000000000..3d6e93bac
--- /dev/null
+++ b/src/rpc/auxpow_miner.cpp
@@ -0,0 +1,165 @@
+// Copyright (c) 2018 Daniel Kraft
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <rpc/auxpow_miner.h>
+
+#include <arith_uint256.h>
+#include <auxpow.h>
+#include <chainparams.h>
+#include <net.h>
+#include <rpc/protocol.h>
+#include <utilstrencodings.h>
+#include <utiltime.h>
+#include <validation.h>
+
+#include <cassert>
+
+namespace
+{
+
+void auxMiningCheck()
+{
+  if (!g_connman)
+    throw JSONRPCError (RPC_CLIENT_P2P_DISABLED,
+                        "Error: Peer-to-peer functionality missing or"
+                        " disabled");
+
+  if (g_connman->GetNodeCount (CConnman::CONNECTIONS_ALL) == 0
+        && !Params ().MineBlocksOnDemand ())
+    throw JSONRPCError (RPC_CLIENT_NOT_CONNECTED,
+                        "Dogecoin is not connected!");
+
+  if (IsInitialBlockDownload () && !Params ().MineBlocksOnDemand ())
+    throw JSONRPCError (RPC_CLIENT_IN_INITIAL_DOWNLOAD,
+                        "Dogecoin is downloading blocks...");
+
+  /* This should never fail, since the chain is already
+     past the point of merge-mining start.  Check nevertheless.  */
+  {
+    LOCK (cs_main);
+    const auto auxpowStart = Params ().GetConsensus ().nAuxpowStartHeight;
+    if (chainActive.Height () + 1 < auxpowStart)
+      throw std::runtime_error ("mining auxblock method is not yet available");
+  }
+}
+
+}  // anonymous namespace
+
+const CBlock*
+AuxpowMiner::getCurrentBlock (const CScript& scriptPubKey, uint256& target)
+{
+  AssertLockHeld (cs);
+
+  {
+    LOCK (cs_main);
+    if (pindexPrev != chainActive.Tip ()
+        || (mempool.GetTransactionsUpdated () != txUpdatedLast
+            && GetTime () - startTime > 60))
+      {
+        if (pindexPrev != chainActive.Tip ())
+          {
+            /* Clear old blocks since they're obsolete now.  */
+            blocks.clear ();
+            templates.clear ();
+            pblockCur = nullptr;
+          }
+
+        /* Create new block with nonce = 0 and extraNonce = 1.  */
+        std::unique_ptr<CBlockTemplate> newBlock
+            = BlockAssembler (Params ()).CreateNewBlock (scriptPubKey);
+        if (newBlock == nullptr)
+          throw JSONRPCError (RPC_OUT_OF_MEMORY, "out of memory");
+
+        /* Update state only when CreateNewBlock succeeded.  */
+        txUpdatedLast = mempool.GetTransactionsUpdated ();
+        pindexPrev = chainActive.Tip ();
+        startTime = GetTime ();
+
+        /* Finalise it by setting the version and building the merkle root.  */
+        IncrementExtraNonce (&newBlock->block, pindexPrev, extraNonce);
+        newBlock->block.SetAuxpowFlag (true);
+
+        /* Save in our map of constructed blocks.  */
+        pblockCur = &newBlock->block;
+        blocks[pblockCur->GetHash ()] = pblockCur;
+        templates.push_back (std::move (newBlock));
+      }
+  }
+
+  /* At this point, pblockCur is always initialised:  If we make it here
+     without creating a new block above, it means that, in particular,
+     pindexPrev == chainActive.Tip().  But for that to happen, we must
+     already have created a pblockCur in a previous call, as pindexPrev is
+     initialised only when pblockCur is.  */
+  assert (pblockCur);
+
+  arith_uint256 arithTarget;
+  bool fNegative, fOverflow;
+  arithTarget.SetCompact (pblockCur->nBits, &fNegative, &fOverflow);
+  if (fNegative || fOverflow || arithTarget == 0)
+    throw std::runtime_error ("invalid difficulty bits in block");
+  target = ArithToUint256 (arithTarget);
+
+  return pblockCur;
+}
+
+const CBlock*
+AuxpowMiner::lookupSavedBlock (const std::string& hashHex) const
+{
+  AssertLockHeld (cs);
+
+  uint256 hash;
+  hash.SetHex (hashHex);
+
+  const auto iter = blocks.find (hash);
+  if (iter == blocks.end ())
+    throw JSONRPCError (RPC_INVALID_PARAMETER, "block hash unknown");
+
+  return iter->second;
+}
+
+UniValue
+AuxpowMiner::createAuxBlock (const CScript& scriptPubKey)
+{
+  auxMiningCheck ();
+  LOCK (cs);
+
+  uint256 target;
+  const CBlock* pblock = getCurrentBlock (scriptPubKey, target);
+
+  UniValue result(UniValue::VOBJ);
+  result.pushKV ("hash", pblock->GetHash ().GetHex ());
+  result.pushKV ("chainid", pblock->GetChainId ());
+  result.pushKV ("previousblockhash", pblock->hashPrevBlock.GetHex ());
+  result.pushKV ("coinbasevalue",
+                 static_cast<int64_t> (pblock->vtx[0]->vout[0].nValue));
+  result.pushKV ("bits", strprintf ("%08x", pblock->nBits));
+  result.pushKV ("height", static_cast<int64_t> (pindexPrev->nHeight + 1));
+  result.pushKV ("target", HexStr (BEGIN (target), END (target)));
+
+  return result;
+}
+
+bool
+AuxpowMiner::submitAuxBlock (const std::string& hashHex,
+                             const std::string& auxpowHex) const
+{
+  auxMiningCheck ();
+
+  std::shared_ptr<CBlock> shared_block;
+  {
+    LOCK (cs);
+    const CBlock* pblock = lookupSavedBlock (hashHex);
+    shared_block = std::make_shared<CBlock> (*pblock);
+  }
+
+  const std::vector<unsigned char> vchAuxPow = ParseHex (auxpowHex);
+  CDataStream ss(vchAuxPow, SER_GETHASH, PROTOCOL_VERSION);
+  std::unique_ptr<CAuxPow> pow(new CAuxPow ());
+  ss >> *pow;
+  shared_block->SetAuxpow (std::move (pow));
+  assert (shared_block->GetHash ().GetHex () == hashHex);
+
+  return ProcessNewBlock (Params (), shared_block, true, nullptr);
+}
diff --git a/src/rpc/auxpow_miner.h b/src/rpc/auxpow_miner.h
new file mode 100644
index 000000000..159495730
--- /dev/null
+++ b/src/rpc/auxpow_miner.h
@@ -0,0 +1,95 @@
+// Copyright (c) 2018 Daniel Kraft
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_RPC_AUXPOW_MINER_H
+#define BITCOIN_RPC_AUXPOW_MINER_H
+
+#include <miner.h>
+#include <script/script.h>
+#include <sync.h>
+#include <uint256.h>
+#include <univalue.h>
+
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace auxpow_tests
+{
+class AuxpowMinerForTest;
+}
+
+/**
+ * This class holds "global" state used to construct blocks for the auxpow
+ * mining RPCs and the map of already constructed blocks to look them up
+ * in the submitauxblock RPC.
+ *
+ * It is used as a singleton that is initialised during startup, taking the
+ * place of the previously real global and static variables.
+ */
+class AuxpowMiner
+{
+
+private:
+
+  /** The lock used for state in this object.  */
+  mutable CCriticalSection cs;
+  /** All currently "active" block templates.  */
+  std::vector<std::unique_ptr<CBlockTemplate>> templates;
+  /** Maps block hashes to pointers in vTemplates.  Does not own the memory.  */
+  std::map<uint256, const CBlock*> blocks;
+
+  /**
+   * The block we are "currently" working on.  This does not own the memory,
+   * instead, it points into an element of templates.
+   */
+  CBlock* pblockCur = nullptr;
+  /** The current extra nonce for block creation.  */
+  unsigned extraNonce = 0;
+
+  /* Some data about when the current block (pblock) was constructed.  */
+  unsigned txUpdatedLast;
+  const CBlockIndex* pindexPrev = nullptr;
+  uint64_t startTime;
+
+  /**
+   * Constructs a new current block if necessary (checking the current state to
+   * see if "enough changed" for this), and returns a pointer to the block
+   * that should be returned to a miner for working on at the moment.  Also
+   * fills in the difficulty target value.
+   */
+  const CBlock* getCurrentBlock (const CScript& scriptPubKey, uint256& target);
+
+  /**
+   * Looks up a previously constructed block by its (hex-encoded) hash.  If the
+   * block is found, it is returned.  Otherwise, a JSONRPCError is thrown.
+   */
+  const CBlock* lookupSavedBlock (const std::string& hashHex) const;
+
+  friend class auxpow_tests::AuxpowMinerForTest;
+
+public:
+
+  AuxpowMiner () = default;
+
+  /**
+   * Performs the main work for the "createauxblock" RPC:  Construct a new block
+   * to work on with the given address for the block reward and return the
+   * necessary information for the miner to construct an auxpow for it.
+   */
+  UniValue createAuxBlock (const CScript& scriptPubKey);
+
+  /**
+   * Performs the main work for the "submitauxblock" RPC:  Look up the block
+   * previously created for the given hash, attach the given auxpow to it
+   * and try to submit it.  Returns true if all was successful and the block
+   * was accepted.
+   */
+  bool submitAuxBlock (const std::string& hashHex,
+                       const std::string& auxpowHex) const;
+
+};
+
+#endif // BITCOIN_RPC_AUXPOW_MINER_H
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 948553d9a..3309a9701 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -80,6 +80,42 @@ double GetDifficulty(const CBlockIndex* blockindex)
     return dDiff;
 }
 
+UniValue AuxpowToJSON(const CAuxPow& auxpow)
+{
+    UniValue result(UniValue::VOBJ);
+
+    {
+        UniValue tx(UniValue::VOBJ);
+        tx.pushKV("hex", EncodeHexTx(*auxpow.coinbaseTx.tx));
+        TxToUniv(*auxpow.coinbaseTx.tx, auxpow.parentBlock.GetHash(), tx);
+        result.pushKV("tx", tx);
+    }
+
+    result.pushKV("index", auxpow.coinbaseTx.nIndex);
+    result.pushKV("chainindex", auxpow.nChainIndex);
+
+    {
+        UniValue branch(UniValue::VARR);
+        for (const auto& node : auxpow.coinbaseTx.vMerkleBranch)
+            branch.push_back(node.GetHex());
+        result.pushKV("merklebranch", branch);
+    }
+
+    {
+        UniValue branch(UniValue::VARR);
+        for (const auto& node : auxpow.vChainMerkleBranch)
+            branch.push_back(node.GetHex());
+        result.pushKV("chainmerklebranch", branch);
+    }
+
+    CDataStream ssParent(SER_NETWORK, PROTOCOL_VERSION);
+    ssParent << auxpow.parentBlock;
+    const std::string strHex = HexStr(ssParent.begin(), ssParent.end());
+    result.pushKV("parentblock", strHex);
+
+    return result;
+}
+
 UniValue blockheaderToJSON(const CBlockIndex* blockindex)
 {
     AssertLockHeld(cs_main);
@@ -148,6 +184,9 @@ UniValue blockToJSON(const CBlock& block, const CBlockIndex* blockindex, bool tx
     result.pushKV("chainwork", blockindex->nChainWork.GetHex());
     result.pushKV("nTx", (uint64_t)blockindex->nTx);
 
+    if (block.auxpow)
+        result.pushKV("auxpow", AuxpowToJSON(*block.auxpow));
+
     if (blockindex->pprev)
         result.pushKV("previousblockhash", blockindex->pprev->GetBlockHash().GetHex());
     CBlockIndex *pnext = chainActive.Next(blockindex);
@@ -729,7 +768,7 @@ static UniValue getblockheader(const JSONRPCRequest& request)
     if (!fVerbose)
     {
         CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION);
-        ssBlock << pblockindex->GetBlockHeader();
+        ssBlock << pblockindex->GetBlockHeader(Params().GetConsensus());
         std::string strHex = HexStr(ssBlock.begin(), ssBlock.end());
         return strHex;
     }
@@ -1270,7 +1309,7 @@ UniValue getblockchaininfo(const JSONRPCRequest& request)
     softforks.push_back(SoftForkDesc("bip34", 2, tip, consensusParams));
     softforks.push_back(SoftForkDesc("bip66", 3, tip, consensusParams));
     softforks.push_back(SoftForkDesc("bip65", 4, tip, consensusParams));
-    for (int pos = Consensus::DEPLOYMENT_CSV; pos != Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++pos) {
+    for (int pos = Consensus::DEPLOYMENT_TESTDUMMY + 1; pos != Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++pos) {
         BIP9SoftForkDescPushBack(bip9_softforks, consensusParams, static_cast<Consensus::DeploymentPos>(pos));
     }
     obj.pushKV("softforks",             softforks);
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 0622e3b72..75c71a323 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -16,6 +16,7 @@
 #include <net.h>
 #include <policy/fees.h>
 #include <pow.h>
+#include <rpc/auxpow_miner.h>
 #include <rpc/blockchain.h>
 #include <rpc/mining.h>
 #include <rpc/server.h>
@@ -26,8 +27,9 @@
 #include <validationinterface.h>
 #include <warnings.h>
 
-#include <memory>
 #include <stdint.h>
+#include <string>
+#include <utility>
 
 unsigned int ParseConfirmTarget(const UniValue& value)
 {
@@ -126,14 +128,15 @@ UniValue generateBlocks(std::shared_ptr<CReserveScript> coinbaseScript, int nGen
             LOCK(cs_main);
             IncrementExtraNonce(pblock, chainActive.Tip(), nExtraNonce);
         }
-        while (nMaxTries > 0 && pblock->nNonce < nInnerLoopCount && !CheckProofOfWork(pblock->GetPoWHash(), pblock->nBits, Params().GetConsensus())) {
-            ++pblock->nNonce;
+        auto& miningHeader = CAuxPow::initAuxPow(*pblock);
+        while (nMaxTries > 0 && miningHeader.nNonce < nInnerLoopCount && !CheckProofOfWork(miningHeader.GetHash(), pblock->nBits, Params().GetConsensus())) {
+            ++miningHeader.nNonce;
             --nMaxTries;
         }
         if (nMaxTries == 0) {
             break;
         }
-        if (pblock->nNonce == nInnerLoopCount) {
+        if (miningHeader.nNonce == nInnerLoopCount) {
             continue;
         }
         std::shared_ptr<const CBlock> shared_pblock = std::make_shared<const CBlock>(*pblock);
@@ -489,11 +492,10 @@ static UniValue getblocktemplate(const JSONRPCRequest& request)
         // TODO: Maybe recheck connections/IBD and (if something wrong) send an expires-immediately template to stop miners?
     }
 
-    const struct VBDeploymentInfo& segwit_info = VersionBitsDeploymentInfo[Consensus::DEPLOYMENT_SEGWIT];
     // If the caller is indicating segwit support, then allow CreateNewBlock()
     // to select witness transactions, after segwit activates (otherwise
     // don't).
-    bool fSupportsSegwit = setClientRules.find(segwit_info.name) != setClientRules.end();
+    bool fSupportsSegwit = setClientRules.find("segwit") != setClientRules.end();
 
     // Update block
     static CBlockIndex* pindexPrev;
@@ -533,7 +535,7 @@ static UniValue getblocktemplate(const JSONRPCRequest& request)
     pblock->nNonce = 0;
 
     // NOTE: If at some point we support pre-segwit miners post-segwit-activation, this needs to take segwit support into consideration
-    const bool fPreSegWit = (ThresholdState::ACTIVE != VersionBitsState(pindexPrev, consensusParams, Consensus::DEPLOYMENT_SEGWIT, versionbitscache));
+    const bool fPreSegWit = !IsWitnessEnabled(pindexPrev, consensusParams);
 
     UniValue aCaps(UniValue::VARR); aCaps.push_back("proposal");
 
@@ -932,6 +934,68 @@ static UniValue estimaterawfee(const JSONRPCRequest& request)
     return result;
 }
 
+/* ************************************************************************** */
+/* Merge mining.  */
+
+std::unique_ptr<AuxpowMiner> g_auxpow_miner;
+
+UniValue createauxblock(const JSONRPCRequest& request)
+{
+    if (request.fHelp || request.params.size() != 1)
+        throw std::runtime_error(
+            "createauxblock <address>\n"
+            "\ncreate a new block and return information required to merge-mine it.\n"
+            "\nArguments:\n"
+            "1. address      (string, required) specify coinbase transaction payout address\n"
+            "\nResult:\n"
+            "{\n"
+            "  \"hash\"               (string) hash of the created block\n"
+            "  \"chainid\"            (numeric) chain ID for this block\n"
+            "  \"previousblockhash\"  (string) hash of the previous block\n"
+            "  \"coinbasevalue\"      (numeric) value of the block's coinbase\n"
+            "  \"bits\"               (string) compressed target of the block\n"
+            "  \"height\"             (numeric) height of the block\n"
+            "  \"target\"             (string) target in reversed byte order\n"
+            "}\n"
+            "\nExamples:\n"
+            + HelpExampleCli("createauxblock", "\"address\"")
+            + HelpExampleRpc("createauxblock", "\"address\"")
+            );
+
+    // Check coinbase payout address
+    const CTxDestination coinbaseScript
+      = DecodeDestination(request.params[0].get_str());
+    if (!IsValidDestination(coinbaseScript)) {
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
+                           "Error: Invalid coinbase payout address");
+    }
+    const CScript scriptPubKey = GetScriptForDestination(coinbaseScript);
+
+    return g_auxpow_miner->createAuxBlock(scriptPubKey);
+}
+
+UniValue submitauxblock(const JSONRPCRequest& request)
+{
+    if (request.fHelp || request.params.size() != 2)
+        throw std::runtime_error(
+            "submitauxblock <hash> <auxpow>\n"
+            "\nsubmit a solved auxpow for a previously block created by 'createauxblock'.\n"
+            "\nArguments:\n"
+            "1. hash      (string, required) hash of the block to submit\n"
+            "2. auxpow    (string, required) serialised auxpow found\n"
+            "\nResult:\n"
+            "xxxxx        (boolean) whether the submitted block was correct\n"
+            "\nExamples:\n"
+            + HelpExampleCli("submitauxblock", "\"hash\" \"serialised auxpow\"")
+            + HelpExampleRpc("submitauxblock", "\"hash\" \"serialised auxpow\"")
+            );
+
+    return g_auxpow_miner->submitAuxBlock(request.params[0].get_str(),
+                                          request.params[1].get_str());
+}
+
+/* ************************************************************************** */
+
 static const CRPCCommand commands[] =
 { //  category              name                      actor (function)         argNames
   //  --------------------- ------------------------  -----------------------  ----------
@@ -940,7 +1004,8 @@ static const CRPCCommand commands[] =
     { "mining",             "prioritisetransaction",  &prioritisetransaction,  {"txid","dummy","fee_delta"} },
     { "mining",             "getblocktemplate",       &getblocktemplate,       {"template_request"} },
     { "mining",             "submitblock",            &submitblock,            {"hexdata","dummy"} },
-
+    { "mining",             "createauxblock",         &createauxblock,         {"address"} },
+    { "mining",             "submitauxblock",         &submitauxblock,         {"hash", "auxpow"} },
 
     { "generating",         "generatetoaddress",      &generatetoaddress,      {"nblocks","address","maxtries"} },
 
diff --git a/src/rpc/mining.h b/src/rpc/mining.h
index 8d4627315..759d35e64 100644
--- a/src/rpc/mining.h
+++ b/src/rpc/mining.h
@@ -9,10 +9,17 @@
 
 #include <univalue.h>
 
+#include <memory>
+
+class AuxpowMiner;
+
 /** Generate blocks (mine) */
 UniValue generateBlocks(std::shared_ptr<CReserveScript> coinbaseScript, int nGenerate, uint64_t nMaxTries, bool keepScript);
 
 /** Check bounds on a command line confirm target */
 unsigned int ParseConfirmTarget(const UniValue& value);
 
+/** Singleton instance of the AuxpowMiner, created during startup.  */
+extern std::unique_ptr<AuxpowMiner> g_auxpow_miner;
+
 #endif