Reapply: Reject transactions with excessive numbers of sigops

Reverting was based on a misunderstanding, it appears.

Github-Pull: #4150

1 files changed, 12 insertions, 3 deletions

diff --git a/src/main.cpp b/src/main.cpp
index 55206600e2..e135e93adb 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -956,9 +956,18 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
         if (Params().RequireStandard() && !AreInputsStandard(tx, view))
             return error("AcceptToMemoryPool: : nonstandard transaction input");
 
-        // Note: if you modify this code to accept non-standard transactions, then
-        // you should add code here to check that the transaction does a
-        // reasonable number of ECDSA signature verifications.
+        // Check that the transaction doesn't have an excessive number of
+        // sigops, making it impossible to mine. Since the coinbase transaction
+        // itself can contain sigops MAX_TX_SIGOPS is less than
+        // MAX_BLOCK_SIGOPS; we still consider this an invalid rather than
+        // merely non-standard transaction.
+        unsigned int nSigOps = GetLegacySigOpCount(tx);
+        nSigOps += GetP2SHSigOpCount(tx, view);
+        if (nSigOps > MAX_TX_SIGOPS)
+            return state.DoS(0,
+                             error("AcceptToMemoryPool : too many sigops %s, %d > %d",
+                                   hash.ToString(), nSigOps, MAX_TX_SIGOPS),
+                             REJECT_NONSTANDARD, "bad-txns-too-many-sigops");
 
         int64_t nValueOut = tx.GetValueOut();
         int64_t nFees = nValueIn-nValueOut;