Merge #19526: log: Avoid treating remote misbehvior as local system error

fa56eda58e5ec2f2345bbe14c798e83f2abb4728 log: Avoid treating remote misbehvior as local system error (MarcoFalke)
fa492895b572a1196ca8652006b6fc2fa1d16951 refactor: Switch ValidationState mode to C++11 enum class (MarcoFalke)

Pull request description:

  When logging failures of `CheckBlockHeader` (high-hash), they are always logged as system error. This is problematic for several reasons:

  * Submitting a blockheader that fails `CheckBlockHeader` over RPC will result in a debug log line that starts with `ERROR`. Proper behaviour should be to log not anything and instead only return the failure reason to the RPC user. This pull does not fix this issue entirely, but is a good first step in the right direction.

  * A misbehaving peer that sends us an invalid block header that fails `CheckBlockHeader` will result in a debug log line that starts with `ERROR`. Proper behavior should be to log the remote peer misbehavior if logging for that category was enabled. This pull fixes this issue for `CheckBlockHeader` and other functions can be adjusted as well if needed in follow-ups. This should be a good first step in the right direction.

ACKs for top commit:
  practicalswift:
    re-ACK fa56eda58e5ec2f2345bbe14c798e83f2abb4728

Tree-SHA512: 9793191f5cb57bdff7c93926e94877e8ca2ef89dcebcf9eb155899c733961839ec7c3f9b9f001dc082ada4234fe6e75f6df431301678d6822325840771166d77

1 files changed, 4 insertions, 2 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index 4fe02ed244..a9cb99aafb 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -3641,8 +3641,10 @@ bool BlockManager::AcceptBlockHeader(const CBlockHeader& block, BlockValidationS
             return true;
         }
 
-        if (!CheckBlockHeader(block, state, chainparams.GetConsensus()))
-            return error("%s: Consensus::CheckBlockHeader: %s, %s", __func__, hash.ToString(), state.ToString());
+        if (!CheckBlockHeader(block, state, chainparams.GetConsensus())) {
+            LogPrint(BCLog::VALIDATION, "%s: Consensus::CheckBlockHeader: %s, %s\n", __func__, hash.ToString(), state.ToString());
+            return false;
+        }
 
         // Get prev block index
         CBlockIndex* pindexPrev = nullptr;