[FIX] blacklist for longer in case of header validation failure

Author: KonradStaniec

src/main/resources/application.conf

@@ -328,6 +328,9 @@ mantis {
     # are controlled by a single party, eg. private networks)
     blacklist-duration = 200.seconds
 
+    # Duration for high offense blacklisting of a peer. Blacklisting reason include: header validation failure.
+    critical-blacklist-duration = 240.minutes
+
     # Retry interval when not having enough peers to start fast-sync
     start-retry-interval = 5.seconds
 

src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala

@@ -408,8 +408,8 @@ class FastSync(
       blockchain.getChainWeightByHash(header.parentHash).toRight(ParentChainWeightNotFound(header))
     }
 
-    private def handleRewind(header: BlockHeader, peer: Peer, N: Int): Unit = {
-      blacklist(peer.id, blacklistDuration, "block header validation failed")
+    private def handleRewind(header: BlockHeader, peer: Peer, N: Int, duration: FiniteDuration): Unit = {
+      blacklist(peer.id, duration, "block header validation failed")
       if (header.number <= syncState.safeDownloadTarget) {
         discardLastBlocks(header.number, N)
         syncState = syncState.updateDiscardedBlocks(header, N)
@@ -431,14 +431,20 @@ class FastSync(
             // we blacklist peer just in case we got malicious peer which would send us bad blocks, forcing us to rollback
             // to genesis
             log.warning("Parent chain weight not found for block {}, not processing rest of headers", header.idTag)
-            handleRewind(header, peer, syncConfig.fastSyncBlockValidationN)
+            handleRewind(header, peer, syncConfig.fastSyncBlockValidationN, syncConfig.blacklistDuration)
           case HeadersProcessingFinished =>
             processSyncing()
           case ImportedPivotBlock =>
             updatePivotBlock(ImportedLastBlock)
           case ValidationFailed(header, peerToBlackList) =>
-            log.warning(s"validation fo header ${header.idTag} failed")
-            handleRewind(header, peerToBlackList, syncConfig.fastSyncBlockValidationN)
+            log.warning(s"validation of header ${header.idTag} failed")
+            // pow validation failure indicate that either peer is malicious or it is on wrong fork
+            handleRewind(
+              header,
+              peerToBlackList,
+              syncConfig.fastSyncBlockValidationN,
+              syncConfig.criticalBlacklistDuration
+            )
         }
       } else {
         blacklist(peer.id, blacklistDuration, "error in block headers response")

src/main/scala/io/iohk/ethereum/utils/Config.scala

@@ -95,6 +95,7 @@ object Config {
       doFastSync: Boolean,
       peersScanInterval: FiniteDuration,
       blacklistDuration: FiniteDuration,
+      criticalBlacklistDuration: FiniteDuration,
       startRetryInterval: FiniteDuration,
       syncRetryInterval: FiniteDuration,
       peerResponseTimeout: FiniteDuration,
@@ -137,6 +138,7 @@ object Config {
         doFastSync = syncConfig.getBoolean("do-fast-sync"),
         peersScanInterval = syncConfig.getDuration("peers-scan-interval").toMillis.millis,
         blacklistDuration = syncConfig.getDuration("blacklist-duration").toMillis.millis,
+        criticalBlacklistDuration = syncConfig.getDuration("critical-blacklist-duration").toMillis.millis,
         startRetryInterval = syncConfig.getDuration("start-retry-interval").toMillis.millis,
         syncRetryInterval = syncConfig.getDuration("sync-retry-interval").toMillis.millis,
         peerResponseTimeout = syncConfig.getDuration("peer-response-timeout").toMillis.millis,

src/test/scala/io/iohk/ethereum/blockchain/sync/TestSyncConfig.scala

@@ -12,6 +12,7 @@ trait TestSyncConfig extends SyncConfigBuilder {
     pivotBlockOffset = 500,
     branchResolutionRequestSize = 2,
     blacklistDuration = 5.seconds,
+    criticalBlacklistDuration = 10.seconds,
     syncRetryInterval = 1.second,
     checkForNewBlockInterval = 1.milli,
     startRetryInterval = 500.milliseconds,