Merge branch 'uasfsegwit+rewind' of https://github.com/luke-jr/bitcoin …

…into luke-jr-uasfsegwit+rewind
UASF · Jul 2, 2017 · 3512f41 · 3512f41
2 parents 5c1fdcb + 6048d3e
commit 3512f41
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Showing 2 changed files with 29 additions and 11 deletions.
diff --git a/src/validation.cpp b/src/validation.cpp
@@ -1853,17 +1853,8 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
 
     if (GetBoolArg("-bip148", DEFAULT_BIP148)) {
         // BIP148 mandatory segwit signalling.
-        int64_t nMedianTimePast = pindex->GetMedianTimePast();
-        if ( (nMedianTimePast >= 1501545600) &&  // Tue 01 Aug 2017 00:00:00 UTC
-             (nMedianTimePast <= 1510704000) &&  // Wed 15 Nov 2017 00:00:00 UTC
-             (!IsWitnessLockedIn(pindex->pprev, chainparams.GetConsensus()) &&  // Segwit is not locked in
-              !IsWitnessEnabled(pindex->pprev, chainparams.GetConsensus())) )   // and is not active.
-        {
-            bool fVersionBits = (pindex->nVersion & VERSIONBITS_TOP_MASK) == VERSIONBITS_TOP_BITS;
-            bool fSegbit = (pindex->nVersion & VersionBitsMask(chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT)) != 0;
-            if (!(fVersionBits && fSegbit)) {
-                return state.DoS(0, error("ConnectBlock(): relayed block must signal for segwit, please upgrade"), REJECT_INVALID, "bad-no-segwit");
-            }
+        if (!CheckBIP148(pindex, chainparams.GetConsensus())) {
+            return state.DoS(0, error("ConnectBlock(): relayed block must signal for segwit, please upgrade"), REJECT_INVALID, "bad-no-segwit");
         }
     }
 
@@ -2940,6 +2931,23 @@ bool IsWitnessLockedIn(const CBlockIndex* pindexPrev, const Consensus::Params& p
     return (VersionBitsState(pindexPrev, params, Consensus::DEPLOYMENT_SEGWIT, versionbitscache) == THRESHOLD_LOCKED_IN);
 }
 
+bool CheckBIP148(const CBlockIndex* pindex, const Consensus::Params& params)
+{
+    int64_t nMedianTimePast = pindex->GetMedianTimePast();
+    if ( (nMedianTimePast >= 1501545600) &&  // Tue 01 Aug 2017 00:00:00 UTC
+         (nMedianTimePast <= 1510704000) &&  // Wed 15 Nov 2017 00:00:00 UTC
+         (!IsWitnessLockedIn(pindex->pprev, params) &&  // Segwit is not locked in
+          !IsWitnessEnabled(pindex->pprev, params)) )   // and is not active.
+    {
+        bool fVersionBits = (pindex->nVersion & VERSIONBITS_TOP_MASK) == VERSIONBITS_TOP_BITS;
+        bool fSegbit = (pindex->nVersion & VersionBitsMask(params, Consensus::DEPLOYMENT_SEGWIT)) != 0;
+        if (!(fVersionBits && fSegbit)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 // Compute at which vout of the block's coinbase transaction the witness
 // commitment occurs, or -1 if not found.
 static int GetWitnessCommitmentIndex(const CBlock& block)
@@ -3728,10 +3736,17 @@ bool RewindBlockIndex(const CChainParams& params)
     LOCK(cs_main);
 
     int nHeight = 1;
+    bool fCheckBIP148 = GetBoolArg("-bip148", DEFAULT_BIP148);
     while (nHeight <= chainActive.Height()) {
         if (IsWitnessEnabled(chainActive[nHeight - 1], params.GetConsensus()) && !(chainActive[nHeight]->nStatus & BLOCK_OPT_WITNESS)) {
             break;
         }
+        if (fCheckBIP148 && !CheckBIP148(chainActive[nHeight], params.GetConsensus())) {
+            if (!(chainActive[nHeight]->nStatus & BLOCK_HAVE_DATA)) {
+                return error("RewindBlockIndex: invalid block found violating BIP148 at height %i has already been pruned", nHeight);
+            }
+            break;
+        }
         nHeight++;
     }
 

diff --git a/src/validation.h b/src/validation.h
@@ -508,6 +508,9 @@ bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& pa
 /** Check if Segregated Witness is Locked In */
 bool IsWitnessLockedIn(const CBlockIndex* pindexPrev, const Consensus::Params& params);
 
+/** Check if block complies with BIP148 rule; note this accepts pindex for the block, not pindexPrev! */
+bool CheckBIP148(const CBlockIndex* pindex, const Consensus::Params&);
+
 /** When there are blocks in the active chain with missing data, rewind the chainstate and remove them from the block index */
 bool RewindBlockIndex(const CChainParams& params);