wallet/rpc: add maxfeerate parameter to testmempoolaccept

2 files changed, 21 insertions, 6 deletions

diff --git a/src/rpc/client.cpp b/src/rpc/client.cpp
index c19160d325..4144a17bc3 100644
--- a/src/rpc/client.cpp
+++ b/src/rpc/client.cpp
@@ -95,6 +95,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "sendrawtransaction", 1, "maxfeerate" },
     { "testmempoolaccept", 0, "rawtxs" },
     { "testmempoolaccept", 1, "allowhighfees" },
+    { "testmempoolaccept", 1, "maxfeerate" },
     { "combinerawtransaction", 0, "txs" },
     { "fundrawtransaction", 1, "options" },
     { "fundrawtransaction", 2, "iswitness" },
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index fedc30dc35..27fb53654f 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -1108,7 +1108,7 @@ static UniValue testmempoolaccept(const JSONRPCRequest& request)
                             {"rawtx", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, ""},
                         },
                         },
-                    {"allowhighfees", RPCArg::Type::BOOL, /* default */ "false", "Allow high fees"},
+                    {"maxfeerate", RPCArg::Type::AMOUNT, /* default */ FormatMoney(maxTxFee), "Reject transactions whose fee rate is higher than the specified value, expressed in " + CURRENCY_UNIT + "/kB\n"},
                 },
                 RPCResult{
             "[                   (array) The result of the mempool acceptance test for each raw transaction in the input array.\n"
@@ -1133,7 +1133,11 @@ static UniValue testmempoolaccept(const JSONRPCRequest& request)
             }.ToString());
     }
 
-    RPCTypeCheck(request.params, {UniValue::VARR, UniValue::VBOOL});
+    RPCTypeCheck(request.params, {
+        UniValue::VARR,
+        UniValueType(), // NUM or BOOL, checked later
+    });
+
     if (request.params[0].get_array().size() != 1) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Array must contain exactly one raw transaction for now");
     }
@@ -1145,9 +1149,19 @@ static UniValue testmempoolaccept(const JSONRPCRequest& request)
     CTransactionRef tx(MakeTransactionRef(std::move(mtx)));
     const uint256& tx_hash = tx->GetHash();
 
-    CAmount max_raw_tx_fee = ::maxTxFee;
-    if (!request.params[1].isNull() && request.params[1].get_bool()) {
-        max_raw_tx_fee = 0;
+    CAmount max_raw_tx_fee = maxTxFee;
+    // TODO: temporary migration code for old clients. Remove in v0.20
+    if (request.params[1].isBool()) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Second argument must be numeric (maxfeerate) and no longer supports a boolean. To allow a transaction with high fees, set maxfeerate to 0.");
+    } else if (request.params[1].isNum()) {
+        size_t weight = GetTransactionWeight(*tx);
+        CFeeRate fr(AmountFromValue(request.params[1]));
+        // the +3/4 part rounds the value up, and is the same formula used when
+        // calculating the fee for a transaction
+        // (see GetVirtualTransactionSize)
+        max_raw_tx_fee = fr.GetFee((weight+3)/4);
+    } else if (!request.params[1].isNull()) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "second argument (maxfeerate) must be numeric");
     }
 
     UniValue result(UniValue::VARR);
@@ -2068,7 +2082,7 @@ static const CRPCCommand commands[] =
     { "rawtransactions",    "combinerawtransaction",        &combinerawtransaction,     {"txs"} },
     { "hidden",             "signrawtransaction",           &signrawtransaction,        {"hexstring","prevtxs","privkeys","sighashtype"} },
     { "rawtransactions",    "signrawtransactionwithkey",    &signrawtransactionwithkey, {"hexstring","privkeys","prevtxs","sighashtype"} },
-    { "rawtransactions",    "testmempoolaccept",            &testmempoolaccept,         {"rawtxs","allowhighfees"} },
+    { "rawtransactions",    "testmempoolaccept",            &testmempoolaccept,         {"rawtxs","allowhighfees|maxfeerate"} },
     { "rawtransactions",    "decodepsbt",                   &decodepsbt,                {"psbt"} },
     { "rawtransactions",    "combinepsbt",                  &combinepsbt,               {"txs"} },
     { "rawtransactions",    "finalizepsbt",                 &finalizepsbt,              {"psbt", "extract"} },