[raw] reject insanely high fees by default in sendrawtransaction

There have been several incidents where mainnet experimentation with
 raw transactions  resulted in insane fees.  This is hard to prevent
 in the raw transaction api because the inputs may not be known.
 Since sending doesn't work if the inputs aren't known, we can catch
 it there.

This rejects fees > than 10000 * nMinRelayTxFee or 1 BTC with the
 defaults and can be overridden with a bool at the rpc.

4 files changed, 15 insertions, 5 deletions

diff --git a/src/bitcoinrpc.cpp b/src/bitcoinrpc.cpp
index d22809ce69..95c0680345 100644
--- a/src/bitcoinrpc.cpp
+++ b/src/bitcoinrpc.cpp
@@ -1193,6 +1193,7 @@ Array RPCConvertValues(const std::string &strMethod, const std::vector<std::stri
     if (strMethod == "createrawtransaction"   && n > 1) ConvertTo<Object>(params[1]);
     if (strMethod == "signrawtransaction"     && n > 1) ConvertTo<Array>(params[1], true);
     if (strMethod == "signrawtransaction"     && n > 2) ConvertTo<Array>(params[2], true);
+    if (strMethod == "sendrawtransaction"     && n > 1) ConvertTo<bool>(params[1], true);
     if (strMethod == "gettxout"               && n > 1) ConvertTo<boost::int64_t>(params[1]);
     if (strMethod == "gettxout"               && n > 2) ConvertTo<bool>(params[2]);
     if (strMethod == "lockunspent"            && n > 0) ConvertTo<bool>(params[0]);
diff --git a/src/main.cpp b/src/main.cpp
index 24fd1fadbc..b21e98413d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -787,7 +787,7 @@ void CTxMemPool::pruneSpent(const uint256 &hashTx, CCoins &coins)
 }
 
 bool CTxMemPool::accept(CValidationState &state, const CTransaction &tx, bool fLimitFree,
-                        bool* pfMissingInputs)
+                        bool* pfMissingInputs, bool fRejectInsaneFee)
 {
     if (pfMissingInputs)
         *pfMissingInputs = false;
@@ -921,6 +921,11 @@ bool CTxMemPool::accept(CValidationState &state, const CTransaction &tx, bool fL
             dFreeCount += nSize;
         }
 
+        if (fRejectInsaneFee && nFees > CTransaction::nMinRelayTxFee * 10000)
+            return error("CTxMemPool::accept() : insane fees %s, %"PRI64d" > %"PRI64d,
+                         hash.ToString().c_str(),
+                         nFees, CTransaction::nMinRelayTxFee * 10000);
+
         // Check against previous transactions
         // This is done last to help prevent CPU exhaustion denial-of-service attacks.
         if (!CheckInputs(tx, state, view, true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_STRICTENC))
diff --git a/src/main.h b/src/main.h
index a690a2bc9c..09e4700fbb 100644
--- a/src/main.h
+++ b/src/main.h
@@ -1082,7 +1082,7 @@ public:
     std::map<uint256, CTransaction> mapTx;
     std::map<COutPoint, CInPoint> mapNextTx;
 
-    bool accept(CValidationState &state, const CTransaction &tx, bool fLimitFree, bool* pfMissingInputs);
+    bool accept(CValidationState &state, const CTransaction &tx, bool fLimitFree, bool* pfMissingInputs, bool fRejectInsaneFee = false);
     bool addUnchecked(const uint256& hash, const CTransaction &tx);
     bool remove(const CTransaction &tx, bool fRecursive = false);
     bool removeConflicts(const CTransaction &tx);
diff --git a/src/rpcrawtransaction.cpp b/src/rpcrawtransaction.cpp
index 580120f2a2..3359e94cce 100644
--- a/src/rpcrawtransaction.cpp
+++ b/src/rpcrawtransaction.cpp
@@ -527,9 +527,9 @@ Value signrawtransaction(const Array& params, bool fHelp)
 
 Value sendrawtransaction(const Array& params, bool fHelp)
 {
-    if (fHelp || params.size() < 1 || params.size() > 1)
+    if (fHelp || params.size() < 1 || params.size() > 2)
         throw runtime_error(
-            "sendrawtransaction <hex string>\n"
+            "sendrawtransaction <hex string> [allowhighfees=false]\n"
             "Submits raw transaction (serialized, hex-encoded) to local node and network.");
 
     // parse hex string from parameter
@@ -537,6 +537,10 @@ Value sendrawtransaction(const Array& params, bool fHelp)
     CDataStream ssData(txData, SER_NETWORK, PROTOCOL_VERSION);
     CTransaction tx;
 
+    bool fOverrideFees = false;
+    if (params.size() > 1)
+        fOverrideFees = params[1].get_bool();
+
     // deserialize binary data stream
     try {
         ssData >> tx;
@@ -554,7 +558,7 @@ Value sendrawtransaction(const Array& params, bool fHelp)
         if (!fHave) {
             // push to local node
             CValidationState state;
-            if (!mempool.accept(state, tx, false, NULL))
+            if (!mempool.accept(state, tx, false, NULL, !fOverrideFees))
                 throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX rejected"); // TODO: report validation state
         }
     }