Remove most logging from transaction validation

Remove unnecessary direct logging in CheckTransaction,
AcceptToMemoryPool, CheckTxInputs, CScriptCheck::operator()

All status information should be returned in the CValidationState.
Relevant debug information is also added to the CValidationState using
the recently introduced debug message.

Do keep the "BUG! PLEASE REPORT THIS! ConnectInputs failed against MANDATORY but not STANDARD flags"
error as it is meant to appear as bug in the log.

src/main.cpp

@@ -696,30 +696,24 @@ bool CheckTransaction(const CTransaction& tx, CValidationState &state)
 {
     // Basic checks that don't depend on any context
     if (tx.vin.empty())
-        return state.DoS(10, error("CheckTransaction(): vin empty"),
-                         REJECT_INVALID, "bad-txns-vin-empty");
+        return state.DoS(10, false, REJECT_INVALID, "bad-txns-vin-empty");
     if (tx.vout.empty())
-        return state.DoS(10, error("CheckTransaction(): vout empty"),
-                         REJECT_INVALID, "bad-txns-vout-empty");
+        return state.DoS(10, false, REJECT_INVALID, "bad-txns-vout-empty");
     // Size limits
     if (::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE)
-        return state.DoS(100, error("CheckTransaction(): size limits failed"),
-                         REJECT_INVALID, "bad-txns-oversize");
+        return state.DoS(100, false, REJECT_INVALID, "bad-txns-oversize");
 
     // Check for negative or overflow output values
     CAmount nValueOut = 0;
     BOOST_FOREACH(const CTxOut& txout, tx.vout)
     {
         if (txout.nValue < 0)
-            return state.DoS(100, error("CheckTransaction(): txout.nValue negative"),
-                             REJECT_INVALID, "bad-txns-vout-negative");
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-vout-negative");
         if (txout.nValue > MAX_MONEY)
-            return state.DoS(100, error("CheckTransaction(): txout.nValue too high"),
-                             REJECT_INVALID, "bad-txns-vout-toolarge");
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-vout-toolarge");
         nValueOut += txout.nValue;
         if (!MoneyRange(nValueOut))
-            return state.DoS(100, error("CheckTransaction(): txout total out of range"),
-                             REJECT_INVALID, "bad-txns-txouttotal-toolarge");
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-txouttotal-toolarge");
     }
 
     // Check for duplicate inputs
@@ -727,23 +721,20 @@ bool CheckTransaction(const CTransaction& tx, CValidationState &state)
     BOOST_FOREACH(const CTxIn& txin, tx.vin)
     {
         if (vInOutPoints.count(txin.prevout))
-            return state.DoS(100, error("CheckTransaction(): duplicate inputs"),
-                             REJECT_INVALID, "bad-txns-inputs-duplicate");
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-inputs-duplicate");
         vInOutPoints.insert(txin.prevout);
     }
 
     if (tx.IsCoinBase())
     {
         if (tx.vin[0].scriptSig.size() < 2 || tx.vin[0].scriptSig.size() > 100)
-            return state.DoS(100, error("CheckTransaction(): coinbase script size"),
-                             REJECT_INVALID, "bad-cb-length");
+            return state.DoS(100, false, REJECT_INVALID, "bad-cb-length");
     }
     else
     {
         BOOST_FOREACH(const CTxIn& txin, tx.vin)
             if (txin.prevout.IsNull())
-                return state.DoS(10, error("CheckTransaction(): prevout is null"),
-                                 REJECT_INVALID, "bad-txns-prevout-null");
+                return state.DoS(10, false, REJECT_INVALID, "bad-txns-prevout-null");
     }
 
     return true;
@@ -795,26 +786,22 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
         *pfMissingInputs = false;
 
     if (!CheckTransaction(tx, state))
-        return error("AcceptToMemoryPool: CheckTransaction failed");
+        return false;
 
     // Coinbase is only valid in a block, not as a loose transaction
     if (tx.IsCoinBase())
-        return state.DoS(100, error("AcceptToMemoryPool: coinbase as individual tx"),
-                         REJECT_INVALID, "coinbase");
+        return state.DoS(100, false, REJECT_INVALID, "coinbase");
 
     // Rather not work on nonstandard transactions (unless -testnet/-regtest)
     string reason;
     if (fRequireStandard && !IsStandardTx(tx, reason))
-        return state.DoS(0,
-                         error("AcceptToMemoryPool: nonstandard transaction: %s", reason),
-                         REJECT_NONSTANDARD, reason);
+        return state.DoS(0, false, REJECT_NONSTANDARD, reason);
 
     // Only accept nLockTime-using transactions that can be mined in the next
     // block; we don't want our mempool filled up with transactions that can't
     // be mined yet.
     if (!CheckFinalTx(tx))
-        return state.DoS(0, error("AcceptToMemoryPool: non-final"),
-                         REJECT_NONSTANDARD, "non-final");
+        return state.DoS(0, false, REJECT_NONSTANDARD, "non-final");
 
     // is it already in the memory pool?
     uint256 hash = tx.GetHash();
@@ -862,8 +849,7 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
 
         // are the actual inputs available?
         if (!view.HaveInputs(tx))
-            return state.Invalid(error("AcceptToMemoryPool: inputs already spent"),
-                                 REJECT_DUPLICATE, "bad-txns-inputs-spent");
+            return state.Invalid(false, REJECT_DUPLICATE, "bad-txns-inputs-spent");
 
         // Bring the best block into scope
         view.GetBestBlock();
@@ -886,10 +872,8 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
         unsigned int nSigOps = GetLegacySigOpCount(tx);
         nSigOps += GetP2SHSigOpCount(tx, view);
         if (nSigOps > MAX_STANDARD_TX_SIGOPS)
-            return state.DoS(0,
-                             error("AcceptToMemoryPool: too many sigops %s, %d > %d",
-                                   hash.ToString(), nSigOps, MAX_STANDARD_TX_SIGOPS),
-                             REJECT_NONSTANDARD, "bad-txns-too-many-sigops");
+            return state.DoS(0, false, REJECT_NONSTANDARD, "bad-txns-too-many-sigops", false,
+                strprintf("%d > %d", nSigOps, MAX_STANDARD_TX_SIGOPS));
 
         CAmount nValueOut = tx.GetValueOut();
         CAmount nFees = nValueIn-nValueOut;
@@ -901,9 +885,8 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
         // Don't accept it if it can't get into a block
         CAmount txMinFee = GetMinRelayFee(tx, nSize, true);
         if (fLimitFree && nFees < txMinFee)
-            return state.DoS(0, error("AcceptToMemoryPool: not enough fees %s, %d < %d",
-                                      hash.ToString(), nFees, txMinFee),
-                             REJECT_INSUFFICIENTFEE, "insufficient fee");
+            return state.DoS(0, false, REJECT_INSUFFICIENTFEE, "insufficient fee", false,
+                strprintf("%d < %d", nFees, txMinFee));
 
         // Require that free transactions have sufficient priority to be mined in the next block.
         if (GetBoolArg("-relaypriority", true) && nFees < ::minRelayTxFee.GetFee(nSize) && !AllowFree(view.GetPriority(tx, chainActive.Height() + 1))) {
@@ -928,24 +911,20 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
             // -limitfreerelay unit is thousand-bytes-per-minute
             // At default rate it would take over a month to fill 1GB
             if (dFreeCount >= GetArg("-limitfreerelay", 15)*10*1000)
-                return state.DoS(0, error("AcceptToMemoryPool: free transaction rejected by rate limiter"),
-                                 REJECT_INSUFFICIENTFEE, "rate limited free transaction");
+                return state.DoS(0, false, REJECT_INSUFFICIENTFEE, "rate limited free transaction");
             LogPrint("mempool", "Rate limit dFreeCount: %g => %g\n", dFreeCount, dFreeCount+nSize);
             dFreeCount += nSize;
         }
 
         if (fRejectAbsurdFee && nFees > ::minRelayTxFee.GetFee(nSize) * 10000)
-            return state.Invalid(error("AcceptToMemoryPool: absurdly high fees %s, %d > %d",
-                                       hash.ToString(),
-                                       nFees, ::minRelayTxFee.GetFee(nSize) * 10000),
-                                 REJECT_HIGHFEE, "absurdly-high-fee");
+            return state.Invalid(false,
+                REJECT_HIGHFEE, "absurdly-high-fee",
+                strprintf("%d > %d", nFees, ::minRelayTxFee.GetFee(nSize) * 10000));
 
         // Check against previous transactions
         // This is done last to help prevent CPU exhaustion denial-of-service attacks.
         if (!CheckInputs(tx, state, view, true, STANDARD_SCRIPT_VERIFY_FLAGS, true))
-        {
-            return error("AcceptToMemoryPool: ConnectInputs failed %s", hash.ToString());
-        }
+            return false;
 
         // Check again against just the consensus-critical mandatory script
         // verification flags, in case of bugs in the standard flags that cause
@@ -958,7 +937,8 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
         // can be exploited as a DoS attack.
         if (!CheckInputs(tx, state, view, true, MANDATORY_SCRIPT_VERIFY_FLAGS, true))
         {
-            return error("AcceptToMemoryPool: BUG! PLEASE REPORT THIS! ConnectInputs failed against MANDATORY but not STANDARD flags %s", hash.ToString());
+            return error("%s: BUG! PLEASE REPORT THIS! ConnectInputs failed against MANDATORY but not STANDARD flags %s, %s",
+                __func__, hash.ToString(), FormatStateMessage(state));
         }
 
         // Store transaction in memory
@@ -1298,7 +1278,7 @@ void UpdateCoins(const CTransaction& tx, CValidationState &state, CCoinsViewCach
 bool CScriptCheck::operator()() {
     const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
     if (!VerifyScript(scriptSig, scriptPubKey, nFlags, CachingTransactionSignatureChecker(ptxTo, nIn, cacheStore), &error)) {
-        return ::error("CScriptCheck(): %s:%d VerifySignature failed: %s", ptxTo->GetHash().ToString(), nIn, ScriptErrorString(error));
+        return false;
     }
     return true;
 }
@@ -1316,7 +1296,7 @@ bool CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoins
         // This doesn't trigger the DoS code on purpose; if it did, it would make it easier
         // for an attacker to attempt to split the network.
         if (!inputs.HaveInputs(tx))
-            return state.Invalid(error("CheckInputs(): %s inputs unavailable", tx.GetHash().ToString()));
+            return state.Invalid(false, 0, "", "Inputs unavailable");
 
         CAmount nValueIn = 0;
         CAmount nFees = 0;
@@ -1329,33 +1309,29 @@ bool CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoins
             // If prev is coinbase, check that it's matured
             if (coins->IsCoinBase()) {
                 if (nSpendHeight - coins->nHeight < COINBASE_MATURITY)
-                    return state.Invalid(
-                        error("CheckInputs(): tried to spend coinbase at depth %d", nSpendHeight - coins->nHeight),
-                        REJECT_INVALID, "bad-txns-premature-spend-of-coinbase");
+                    return state.Invalid(false,
+                        REJECT_INVALID, "bad-txns-premature-spend-of-coinbase",
+                        strprintf("tried to spend coinbase at depth %d", nSpendHeight - coins->nHeight));
             }
 
             // Check for negative or overflow input values
             nValueIn += coins->vout[prevout.n].nValue;
             if (!MoneyRange(coins->vout[prevout.n].nValue) || !MoneyRange(nValueIn))
-                return state.DoS(100, error("CheckInputs(): txin values out of range"),
-                                 REJECT_INVALID, "bad-txns-inputvalues-outofrange");
+                return state.DoS(100, false, REJECT_INVALID, "bad-txns-inputvalues-outofrange");
 
         }
 
         if (nValueIn < tx.GetValueOut())
-            return state.DoS(100, error("CheckInputs(): %s value in (%s) < value out (%s)",
-                                        tx.GetHash().ToString(), FormatMoney(nValueIn), FormatMoney(tx.GetValueOut())),
-                             REJECT_INVALID, "bad-txns-in-belowout");
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-in-belowout", false,
+                strprintf("value in (%s) < value out (%s)", FormatMoney(nValueIn), FormatMoney(tx.GetValueOut())));
 
         // Tally transaction fees
         CAmount nTxFee = nValueIn - tx.GetValueOut();
         if (nTxFee < 0)
-            return state.DoS(100, error("CheckInputs(): %s nTxFee < 0", tx.GetHash().ToString()),
-                             REJECT_INVALID, "bad-txns-fee-negative");
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-fee-negative");
         nFees += nTxFee;
         if (!MoneyRange(nFees))
-            return state.DoS(100, error("CheckInputs(): nFees out of range"),
-                             REJECT_INVALID, "bad-txns-fee-outofrange");
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-fee-outofrange");
     return true;
 }
 }// namespace Consensus