Merge #9672: Opt-into-RBF for RPC & bitcoin-tx

9a5a1d7 RPC/rawtransaction: createrawtransaction: Check opt_into_rbf when provided with either value (Luke Dashjr)
23b0fe3 bitcoin-tx: rbfoptin: Avoid touching nSequence if the value is already opting in (Luke Dashjr)
b005bf2 Introduce MAX_BIP125_RBF_SEQUENCE constant (Luke Dashjr)
575cde4 [bitcoin-tx] add rbfoptin command (Jonas Schnelli)
5d26244 [Tests] extend the replace-by-fee test to cover RPC rawtx features (Jonas Schnelli)
36bcab2 RPC/Wallet: Add RBF support for fundrawtransaction (Luke Dashjr)
891c5ee Wallet: Refactor FundTransaction to accept parameters via CCoinControl (Luke Dashjr)
578ec80 RPC: rawtransaction: Add RBF support for createrawtransaction (Luke Dashjr)

Tree-SHA512: 446e37c617c188cc3b3fd1e2841c98eda6f4869e71cb3249c4a9e54002607d0f1e6bef92187f7894d4e0746ab449cfee89be9f6a1a8831e25c70cf912eac1570

8 files changed, 73 insertions, 25 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index ae2eb29c94..199d60b725 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -198,6 +198,7 @@ libbitcoin_server_a_SOURCES = \
   noui.cpp \
   policy/fees.cpp \
   policy/policy.cpp \
+  policy/rbf.cpp \
   pow.cpp \
   rest.cpp \
   rpc/blockchain.cpp \
@@ -240,7 +241,6 @@ libbitcoin_wallet_a_SOURCES = \
   wallet/rpcwallet.cpp \
   wallet/wallet.cpp \
   wallet/walletdb.cpp \
-  policy/rbf.cpp \
   $(BITCOIN_CORE_H)
 
 # crypto primitives library
diff --git a/src/bitcoin-tx.cpp b/src/bitcoin-tx.cpp
index cf280f485c..367801dd78 100644
--- a/src/bitcoin-tx.cpp
+++ b/src/bitcoin-tx.cpp
@@ -13,6 +13,7 @@
 #include "core_io.h"
 #include "keystore.h"
 #include "policy/policy.h"
+#include "policy/rbf.h"
 #include "primitives/transaction.h"
 #include "script/script.h"
 #include "script/sign.h"
@@ -77,6 +78,7 @@ static int AppInitRawTx(int argc, char* argv[])
         strUsage += HelpMessageOpt("in=TXID:VOUT(:SEQUENCE_NUMBER)", _("Add input to TX"));
         strUsage += HelpMessageOpt("locktime=N", _("Set TX lock time to N"));
         strUsage += HelpMessageOpt("nversion=N", _("Set TX version to N"));
+        strUsage += HelpMessageOpt("rbfoptin(=N)", _("Set RBF opt-in sequence number for input N (if not provided, opt-in all available inputs)"));
         strUsage += HelpMessageOpt("outaddr=VALUE:ADDRESS", _("Add address-based output to TX"));
         strUsage += HelpMessageOpt("outpubkey=VALUE:PUBKEY[:FLAGS]", _("Add pay-to-pubkey output to TX") + ". " +
             _("Optionally add the \"W\" flag to produce a pay-to-witness-pubkey-hash output") + ". " +
@@ -202,6 +204,26 @@ static void MutateTxLocktime(CMutableTransaction& tx, const std::string& cmdVal)
     tx.nLockTime = (unsigned int) newLocktime;
 }
 
+static void MutateTxRBFOptIn(CMutableTransaction& tx, const std::string& strInIdx)
+{
+    // parse requested index
+    int inIdx = atoi(strInIdx);
+    if (inIdx < 0 || inIdx >= (int)tx.vin.size()) {
+        throw std::runtime_error("Invalid TX input index '" + strInIdx + "'");
+    }
+
+    // set the nSequence to MAX_INT - 2 (= RBF opt in flag)
+    int cnt = 0;
+    for (CTxIn& txin : tx.vin) {
+        if (strInIdx == "" || cnt == inIdx) {
+            if (txin.nSequence > MAX_BIP125_RBF_SEQUENCE) {
+                txin.nSequence = MAX_BIP125_RBF_SEQUENCE;
+            }
+        }
+        ++cnt;
+    }
+}
+
 static void MutateTxAddInput(CMutableTransaction& tx, const std::string& strInput)
 {
     std::vector<std::string> vStrInputParts;
@@ -649,6 +671,9 @@ static void MutateTx(CMutableTransaction& tx, const std::string& command,
         MutateTxVersion(tx, commandVal);
     else if (command == "locktime")
         MutateTxLocktime(tx, commandVal);
+    else if (command == "rbfoptin") {
+        MutateTxRBFOptIn(tx, commandVal);
+    }
 
     else if (command == "delin")
         MutateTxDelInput(tx, commandVal);
diff --git a/src/policy/rbf.h b/src/policy/rbf.h
index 139aec5760..22c73f3319 100644
--- a/src/policy/rbf.h
+++ b/src/policy/rbf.h
@@ -7,6 +7,8 @@
 
 #include "txmempool.h"
 
+static const uint32_t MAX_BIP125_RBF_SEQUENCE = 0xfffffffd;
+
 enum RBFTransactionState {
     RBF_TRANSACTIONSTATE_UNKNOWN,
     RBF_TRANSACTIONSTATE_REPLACEABLE_BIP125,
diff --git a/src/rpc/client.cpp b/src/rpc/client.cpp
index ed83d1da1e..8dd84e20c9 100644
--- a/src/rpc/client.cpp
+++ b/src/rpc/client.cpp
@@ -86,6 +86,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "createrawtransaction", 0, "inputs" },
     { "createrawtransaction", 1, "outputs" },
     { "createrawtransaction", 2, "locktime" },
+    { "createrawtransaction", 3, "optintorbf" },
     { "signrawtransaction", 1, "prevtxs" },
     { "signrawtransaction", 2, "privkeys" },
     { "sendrawtransaction", 1, "allowhighfees" },
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index e27c2a77c7..00ddd9d16f 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -14,6 +14,7 @@
 #include "merkleblock.h"
 #include "net.h"
 #include "policy/policy.h"
+#include "policy/rbf.h"
 #include "primitives/transaction.h"
 #include "rpc/server.h"
 #include "script/script.h"
@@ -289,9 +290,9 @@ UniValue verifytxoutproof(const JSONRPCRequest& request)
 
 UniValue createrawtransaction(const JSONRPCRequest& request)
 {
-    if (request.fHelp || request.params.size() < 2 || request.params.size() > 3)
+    if (request.fHelp || request.params.size() < 2 || request.params.size() > 4)
         throw std::runtime_error(
-            "createrawtransaction [{\"txid\":\"id\",\"vout\":n},...] {\"address\":amount,\"data\":\"hex\",...} ( locktime )\n"
+            "createrawtransaction [{\"txid\":\"id\",\"vout\":n},...] {\"address\":amount,\"data\":\"hex\",...} ( locktime ) ( optintorbf )\n"
             "\nCreate a transaction spending the given inputs and creating new outputs.\n"
             "Outputs can be addresses or data.\n"
             "Returns hex-encoded raw transaction.\n"
@@ -315,6 +316,7 @@ UniValue createrawtransaction(const JSONRPCRequest& request)
             "      ,...\n"
             "    }\n"
             "3. locktime                  (numeric, optional, default=0) Raw locktime. Non-0 value also locktime-activates inputs\n"
+            "4. optintorbf                (boolean, optional, default=false) Allow this transaction to be replaced by a transaction with higher fees. If provided, it is an error if explicit sequence numbers are incompatible.\n"
             "\nResult:\n"
             "\"transaction\"              (string) hex string of the transaction\n"
 
@@ -341,6 +343,8 @@ UniValue createrawtransaction(const JSONRPCRequest& request)
         rawTx.nLockTime = nLockTime;
     }
 
+    bool rbfOptIn = request.params.size() > 3 ? request.params[3].isTrue() : false;
+
     for (unsigned int idx = 0; idx < inputs.size(); idx++) {
         const UniValue& input = inputs[idx];
         const UniValue& o = input.get_obj();
@@ -354,16 +358,24 @@ UniValue createrawtransaction(const JSONRPCRequest& request)
         if (nOutput < 0)
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, vout must be positive");
 
-        uint32_t nSequence = (rawTx.nLockTime ? std::numeric_limits<uint32_t>::max() - 1 : std::numeric_limits<uint32_t>::max());
+        uint32_t nSequence;
+        if (rbfOptIn) {
+            nSequence = MAX_BIP125_RBF_SEQUENCE;
+        } else if (rawTx.nLockTime) {
+            nSequence = std::numeric_limits<uint32_t>::max() - 1;
+        } else {
+            nSequence = std::numeric_limits<uint32_t>::max();
+        }
 
         // set the sequence number if passed in the parameters object
         const UniValue& sequenceObj = find_value(o, "sequence");
         if (sequenceObj.isNum()) {
             int64_t seqNr64 = sequenceObj.get_int64();
-            if (seqNr64 < 0 || seqNr64 > std::numeric_limits<uint32_t>::max())
+            if (seqNr64 < 0 || seqNr64 > std::numeric_limits<uint32_t>::max()) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, sequence number is out of range");
-            else
+            } else {
                 nSequence = (uint32_t)seqNr64;
+            }
         }
 
         CTxIn in(COutPoint(txid, nOutput), CScript(), nSequence);
@@ -397,6 +409,10 @@ UniValue createrawtransaction(const JSONRPCRequest& request)
         }
     }
 
+    if (request.params.size() > 3 && rbfOptIn != SignalsOptInRBF(rawTx)) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter combination: Sequence number(s) contradict optintorbf option");
+    }
+
     return EncodeHexTx(rawTx);
 }
 
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 3b6dfd42ca..0841c23b86 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -21,6 +21,7 @@
 #include "timedata.h"
 #include "util.h"
 #include "utilmoneystr.h"
+#include "wallet/coincontrol.h"
 #include "wallet/feebumper.h"
 #include "wallet/wallet.h"
 #include "wallet/walletdb.h"
@@ -2628,7 +2629,7 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
         return NullUniValue;
     }
 
-    if (request.fHelp || request.params.size() < 1 || request.params.size() > 2)
+    if (request.fHelp || request.params.size() < 1 || request.params.size() > 3)
         throw std::runtime_error(
                             "fundrawtransaction \"hexstring\" ( options )\n"
                             "\nAdd inputs to a transaction until it has enough in value to meet its out value.\n"
@@ -2657,6 +2658,7 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
                             "                              Those recipients will receive less bitcoins than you enter in their corresponding amount field.\n"
                             "                              If no outputs are specified here, the sender pays the fee.\n"
                             "                                  [vout_index,...]\n"
+                            "     \"optIntoRbf\"             (boolean, optional) Allow this transaction to be replaced by a transaction with higher fees\n"
                             "   }\n"
                             "                         for backward compatibility: passing in a true instead of an object will result in {\"includeWatching\":true}\n"
                             "\nResult:\n"
@@ -2678,20 +2680,21 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
 
     RPCTypeCheck(request.params, boost::assign::list_of(UniValue::VSTR));
 
-    CTxDestination changeAddress = CNoDestination();
+    CCoinControl coinControl;
+    coinControl.destChange = CNoDestination();
     int changePosition = -1;
-    bool includeWatching = false;
+    coinControl.fAllowWatchOnly = false;  // include watching
     bool lockUnspents = false;
     bool reserveChangeKey = true;
-    CFeeRate feeRate = CFeeRate(0);
-    bool overrideEstimatedFeerate = false;
+    coinControl.nFeeRate = CFeeRate(0);
+    coinControl.fOverrideFeeRate = false;
     UniValue subtractFeeFromOutputs;
     std::set<int> setSubtractFeeFromOutputs;
 
     if (request.params.size() > 1) {
       if (request.params[1].type() == UniValue::VBOOL) {
         // backward compatibility bool only fallback
-        includeWatching = request.params[1].get_bool();
+        coinControl.fAllowWatchOnly = request.params[1].get_bool();
       }
       else {
         RPCTypeCheck(request.params, boost::assign::list_of(UniValue::VSTR)(UniValue::VOBJ));
@@ -2707,6 +2710,7 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
                 {"reserveChangeKey", UniValueType(UniValue::VBOOL)},
                 {"feeRate", UniValueType()}, // will be checked below
                 {"subtractFeeFromOutputs", UniValueType(UniValue::VARR)},
+                {"optIntoRbf", UniValueType(UniValue::VBOOL)},
             },
             true, true);
 
@@ -2716,14 +2720,14 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
             if (!address.IsValid())
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "changeAddress must be a valid bitcoin address");
 
-            changeAddress = address.Get();
+            coinControl.destChange = address.Get();
         }
 
         if (options.exists("changePosition"))
             changePosition = options["changePosition"].get_int();
 
         if (options.exists("includeWatching"))
-            includeWatching = options["includeWatching"].get_bool();
+            coinControl.fAllowWatchOnly = options["includeWatching"].get_bool();
 
         if (options.exists("lockUnspents"))
             lockUnspents = options["lockUnspents"].get_bool();
@@ -2733,12 +2737,16 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
 
         if (options.exists("feeRate"))
         {
-            feeRate = CFeeRate(AmountFromValue(options["feeRate"]));
-            overrideEstimatedFeerate = true;
+            coinControl.nFeeRate = CFeeRate(AmountFromValue(options["feeRate"]));
+            coinControl.fOverrideFeeRate = true;
         }
 
         if (options.exists("subtractFeeFromOutputs"))
             subtractFeeFromOutputs = options["subtractFeeFromOutputs"].get_array();
+
+        if (options.exists("optIntoRbf")) {
+            coinControl.signalRbf = options["optIntoRbf"].get_bool();
+        }
       }
     }
 
@@ -2767,7 +2775,7 @@ UniValue fundrawtransaction(const JSONRPCRequest& request)
     CAmount nFeeOut;
     std::string strFailReason;
 
-    if (!pwallet->FundTransaction(tx, nFeeOut, overrideEstimatedFeerate, feeRate, changePosition, strFailReason, includeWatching, lockUnspents, setSubtractFeeFromOutputs, reserveChangeKey, changeAddress)) {
+    if (!pwallet->FundTransaction(tx, nFeeOut, changePosition, strFailReason, lockUnspents, setSubtractFeeFromOutputs, coinControl, reserveChangeKey)) {
         throw JSONRPCError(RPC_WALLET_ERROR, strFailReason);
     }
 
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 3e000d2a9d..b2706d09f6 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2414,7 +2414,7 @@ bool CWallet::SignTransaction(CMutableTransaction &tx)
     return true;
 }
 
-bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, bool overrideEstimatedFeeRate, const CFeeRate& specificFeeRate, int& nChangePosInOut, std::string& strFailReason, bool includeWatching, bool lockUnspents, const std::set<int>& setSubtractFeeFromOutputs, bool keepReserveKey, const CTxDestination& destChange)
+bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nChangePosInOut, std::string& strFailReason, bool lockUnspents, const std::set<int>& setSubtractFeeFromOutputs, CCoinControl coinControl, bool keepReserveKey)
 {
     std::vector<CRecipient> vecSend;
 
@@ -2426,12 +2426,7 @@ bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, bool ov
         vecSend.push_back(recipient);
     }
 
-    CCoinControl coinControl;
-    coinControl.destChange = destChange;
     coinControl.fAllowOtherInputs = true;
-    coinControl.fAllowWatchOnly = includeWatching;
-    coinControl.fOverrideFeeRate = overrideEstimatedFeeRate;
-    coinControl.nFeeRate = specificFeeRate;
 
     BOOST_FOREACH(const CTxIn& txin, tx.vin)
         coinControl.Select(txin.prevout);
@@ -2690,9 +2685,10 @@ bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletT
                 // and in the spirit of "smallest possible change from prior
                 // behavior."
                 bool rbf = coinControl ? coinControl->signalRbf : fWalletRbf;
+                const uint32_t nSequence = rbf ? MAX_BIP125_RBF_SEQUENCE : (std::numeric_limits<unsigned int>::max() - 1);
                 for (const auto& coin : setCoins)
                     txNew.vin.push_back(CTxIn(coin.outpoint,CScript(),
-                                              std::numeric_limits<unsigned int>::max() - (rbf ? 2 : 1)));
+                                              nSequence));
 
                 // Fill in dummy signatures for fee calculation.
                 if (!DummySignTx(txNew, setCoins)) {
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 8276b29a55..a9c50aee4d 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -932,7 +932,7 @@ public:
      * Insert additional inputs into the transaction by
      * calling CreateTransaction();
      */
-    bool FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, bool overrideEstimatedFeeRate, const CFeeRate& specificFeeRate, int& nChangePosInOut, std::string& strFailReason, bool includeWatching, bool lockUnspents, const std::set<int>& setSubtractFeeFromOutputs, bool keepReserveKey = true, const CTxDestination& destChange = CNoDestination());
+    bool FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nChangePosInOut, std::string& strFailReason, bool lockUnspents, const std::set<int>& setSubtractFeeFromOutputs, CCoinControl, bool keepReserveKey = true);
     bool SignTransaction(CMutableTransaction& tx);
 
     /**