Move ::nMinimumChainWork into ChainstateManager

This changes the minimum chain work for the bitcoin-chainstate
executable. Previously it was uint256{}, now it is the chain's default
minimum chain work.

8 files changed, 53 insertions, 33 deletions

diff --git a/src/init.cpp b/src/init.cpp
index b99f16d85e..0c368d8bac 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -937,16 +937,6 @@ bool AppInitParameterInteraction(const ArgsManager& args, bool use_syscall_sandb
     fCheckBlockIndex = args.GetBoolArg("-checkblockindex", chainparams.DefaultConsistencyChecks());
     fCheckpointsEnabled = args.GetBoolArg("-checkpoints", DEFAULT_CHECKPOINTS_ENABLED);
 
-    if (args.IsArgSet("-minimumchainwork")) {
-        const std::string minChainWorkStr = args.GetArg("-minimumchainwork", "");
-        if (!IsHexNumber(minChainWorkStr)) {
-            return InitError(strprintf(Untranslated("Invalid non-hex (%s) minimum chain work value specified"), minChainWorkStr));
-        }
-        nMinimumChainWork = UintToArith256(uint256S(minChainWorkStr));
-    } else {
-        nMinimumChainWork = UintToArith256(chainparams.GetConsensus().nMinimumChainWork);
-    }
-
     // block pruning; get the amount of disk space (in MiB) to allot for block & undo files
     int64_t nPruneArg = args.GetIntArg("-prune", 0);
     if (nPruneArg < 0) {
@@ -1044,6 +1034,16 @@ bool AppInitParameterInteraction(const ArgsManager& args, bool use_syscall_sandb
     }
 #endif // USE_SYSCALL_SANDBOX
 
+    // Also report errors from parsing before daemonization
+    {
+        ChainstateManager::Options chainman_opts_dummy{
+            .chainparams = chainparams,
+        };
+        if (const auto error{ApplyArgsManOptions(args, chainman_opts_dummy)}) {
+            return InitError(*error);
+        }
+    }
+
     return true;
 }
 
@@ -1439,7 +1439,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         .chainparams = chainparams,
         .adjusted_time_callback = GetAdjustedTime,
     };
-    ApplyArgsManOptions(args, chainman_opts);
+    Assert(!ApplyArgsManOptions(args, chainman_opts)); // no error can happen, already checked in AppInitParameterInteraction
 
     // cache size calculations
     CacheSizes cache_sizes = CalculateCacheSizes(args, g_enabled_filter_types.size());
diff --git a/src/kernel/chainstatemanager_opts.h b/src/kernel/chainstatemanager_opts.h
index f698372d05..90acfab63a 100644
--- a/src/kernel/chainstatemanager_opts.h
+++ b/src/kernel/chainstatemanager_opts.h
@@ -5,6 +5,7 @@
 #ifndef BITCOIN_KERNEL_CHAINSTATEMANAGER_OPTS_H
 #define BITCOIN_KERNEL_CHAINSTATEMANAGER_OPTS_H
 
+#include <arith_uint256.h>
 #include <uint256.h>
 #include <util/time.h>
 
@@ -26,6 +27,8 @@ namespace kernel {
 struct ChainstateManagerOpts {
     const CChainParams& chainparams;
     const std::function<NodeClock::time_point()> adjusted_time_callback{nullptr};
+    //! If set, it will override the minimum work we will assume exists on some valid chain.
+    std::optional<arith_uint256> minimum_chain_work;
     //! If set, it will override the block hash whose ancestors we will assume to have valid scripts without checking them.
     std::optional<uint256> assumed_valid_block;
     //! If the tip is older than this, the node is considered to be in initial block download.
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index c87b0e7cd2..19438149e6 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1291,7 +1291,7 @@ void PeerManagerImpl::FindNextBlocksToDownload(const Peer& peer, unsigned int co
     // Make sure pindexBestKnownBlock is up to date, we'll need it.
     ProcessBlockAvailability(peer.m_id);
 
-    if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->nChainWork < m_chainman.ActiveChain().Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < nMinimumChainWork) {
+    if (state->pindexBestKnownBlock == nullptr || state->pindexBestKnownBlock->nChainWork < m_chainman.ActiveChain().Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < m_chainman.MinimumChainWork()) {
         // This peer has nothing interesting.
         return;
     }
@@ -2392,7 +2392,7 @@ arith_uint256 PeerManagerImpl::GetAntiDoSWorkThreshold()
         // near our tip.
         near_chaintip_work = tip->nChainWork - std::min<arith_uint256>(144*GetBlockProof(*tip), tip->nChainWork);
     }
-    return std::max(near_chaintip_work, arith_uint256(nMinimumChainWork));
+    return std::max(near_chaintip_work, m_chainman.MinimumChainWork());
 }
 
 /**
@@ -2702,14 +2702,14 @@ void PeerManagerImpl::UpdatePeerStateForReceivedHeaders(CNode& pfrom,
     if (m_chainman.ActiveChainstate().IsInitialBlockDownload() && !may_have_more_headers) {
         // If the peer has no more headers to give us, then we know we have
         // their tip.
-        if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < nMinimumChainWork) {
+        if (nodestate->pindexBestKnownBlock && nodestate->pindexBestKnownBlock->nChainWork < m_chainman.MinimumChainWork()) {
             // This peer has too little work on their headers chain to help
             // us sync -- disconnect if it is an outbound disconnection
             // candidate.
-            // Note: We compare their tip to nMinimumChainWork (rather than
+            // Note: We compare their tip to the minumum chain work (rather than
             // m_chainman.ActiveChain().Tip()) because we won't start block download
             // until we have a headers chain that has at least
-            // nMinimumChainWork, even if a peer has a chain past our tip,
+            // the minimum chain work, even if a peer has a chain past our tip,
             // as an anti-DoS measure.
             if (pfrom.IsOutboundOrBlockRelayConn()) {
                 LogPrintf("Disconnecting outbound peer %d -- headers chain has insufficient work\n", pfrom.GetId());
@@ -3893,12 +3893,12 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         // Note that if we were to be on a chain that forks from the checkpointed
         // chain, then serving those headers to a peer that has seen the
         // checkpointed chain would cause that peer to disconnect us. Requiring
-        // that our chainwork exceed nMinimumChainWork is a protection against
+        // that our chainwork exceed the mimimum chain work is a protection against
         // being fed a bogus chain when we started up for the first time and
         // getting partitioned off the honest network for serving that chain to
         // others.
         if (m_chainman.ActiveTip() == nullptr ||
-                (m_chainman.ActiveTip()->nChainWork < nMinimumChainWork && !pfrom.HasPermission(NetPermissionFlags::Download))) {
+                (m_chainman.ActiveTip()->nChainWork < m_chainman.MinimumChainWork() && !pfrom.HasPermission(NetPermissionFlags::Download))) {
             LogPrint(BCLog::NET, "Ignoring getheaders from peer=%d because active chain has too little work; sending empty response\n", pfrom.GetId());
             // Just respond with an empty headers message, to tell the peer to
             // go away but not treat us as unresponsive.
@@ -4362,7 +4362,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
             // (eg disk space). Because we only try to reconstruct blocks when
             // we're close to caught up (via the CanDirectFetch() requirement
             // above, combined with the behavior of not requesting blocks until
-            // we have a chain with at least nMinimumChainWork), and we ignore
+            // we have a chain with at least the minimum chain work), and we ignore
             // compact blocks with less work than our tip, it is safe to treat
             // reconstructed compact blocks as having been requested.
             ProcessBlock(pfrom, pblock, /*force_processing=*/true, /*min_pow_checked=*/true);
@@ -5228,7 +5228,7 @@ void PeerManagerImpl::MaybeSendSendHeaders(CNode& node, Peer& peer)
         LOCK(cs_main);
         CNodeState &state = *State(node.GetId());
         if (state.pindexBestKnownBlock != nullptr &&
-                state.pindexBestKnownBlock->nChainWork > nMinimumChainWork) {
+                state.pindexBestKnownBlock->nChainWork > m_chainman.MinimumChainWork()) {
             // Tell our peer we prefer to receive headers rather than inv's
             // We send this to non-NODE NETWORK peers as well, because even
             // non-NODE NETWORK peers can announce blocks (such as pruning
diff --git a/src/node/chainstate.cpp b/src/node/chainstate.cpp
index d9df4b48b5..57d0083d89 100644
--- a/src/node/chainstate.cpp
+++ b/src/node/chainstate.cpp
@@ -37,8 +37,8 @@ ChainstateLoadResult LoadChainstate(ChainstateManager& chainman, const CacheSize
     } else {
         LogPrintf("Validating signatures for all blocks.\n");
     }
-    LogPrintf("Setting nMinimumChainWork=%s\n", nMinimumChainWork.GetHex());
-    if (nMinimumChainWork < UintToArith256(chainman.GetConsensus().nMinimumChainWork)) {
+    LogPrintf("Setting nMinimumChainWork=%s\n", chainman.MinimumChainWork().GetHex());
+    if (chainman.MinimumChainWork() < UintToArith256(chainman.GetConsensus().nMinimumChainWork)) {
         LogPrintf("Warning: nMinimumChainWork set below default value of %s\n", chainman.GetConsensus().nMinimumChainWork.GetHex());
     }
     if (nPruneTarget == std::numeric_limits<uint64_t>::max()) {
diff --git a/src/node/chainstatemanager_args.cpp b/src/node/chainstatemanager_args.cpp
index 811d812e9f..4716be46b5 100644
--- a/src/node/chainstatemanager_args.cpp
+++ b/src/node/chainstatemanager_args.cpp
@@ -4,16 +4,32 @@
 
 #include <node/chainstatemanager_args.h>
 
+#include <arith_uint256.h>
+#include <tinyformat.h>
+#include <uint256.h>
+#include <util/strencodings.h>
 #include <util/system.h>
+#include <util/translation.h>
+#include <validation.h>
 
 #include <chrono>
 #include <optional>
+#include <string>
 
 namespace node {
-void ApplyArgsManOptions(const ArgsManager& args, ChainstateManager::Options& opts)
+std::optional<bilingual_str> ApplyArgsManOptions(const ArgsManager& args, ChainstateManager::Options& opts)
 {
+    if (auto value{args.GetArg("-minimumchainwork")}) {
+        if (!IsHexNumber(*value)) {
+            return strprintf(Untranslated("Invalid non-hex (%s) minimum chain work value specified"), *value);
+        }
+        opts.minimum_chain_work = UintToArith256(uint256S(*value));
+    }
+
     if (auto value{args.GetArg("-assumevalid")}) opts.assumed_valid_block = uint256S(*value);
 
     if (auto value{args.GetIntArg("-maxtipage")}) opts.max_tip_age = std::chrono::seconds{*value};
+
+    return std::nullopt;
 }
 } // namespace node
diff --git a/src/node/chainstatemanager_args.h b/src/node/chainstatemanager_args.h
index 847ddefb8c..6c46b998f2 100644
--- a/src/node/chainstatemanager_args.h
+++ b/src/node/chainstatemanager_args.h
@@ -7,10 +7,13 @@
 
 #include <validation.h>
 
+#include <optional>
+
 class ArgsManager;
+struct bilingual_str;
 
 namespace node {
-void ApplyArgsManOptions(const ArgsManager& args, ChainstateManager::Options& opts);
+std::optional<bilingual_str> ApplyArgsManOptions(const ArgsManager& args, ChainstateManager::Options& opts);
 } // namespace node
 
 #endif // BITCOIN_NODE_CHAINSTATEMANAGER_ARGS_H
diff --git a/src/validation.cpp b/src/validation.cpp
index a6f71aba9f..3df4bfb0d0 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -124,8 +124,6 @@ bool g_parallel_script_checks{false};
 bool fCheckBlockIndex = false;
 bool fCheckpointsEnabled = DEFAULT_CHECKPOINTS_ENABLED;
 
-arith_uint256 nMinimumChainWork;
-
 const CBlockIndex* Chainstate::FindForkInGlobalIndex(const CBlockLocator& locator) const
 {
     AssertLockHeld(cs_main);
@@ -1544,8 +1542,9 @@ bool Chainstate::IsInitialBlockDownload() const
         return true;
     if (m_chain.Tip() == nullptr)
         return true;
-    if (m_chain.Tip()->nChainWork < nMinimumChainWork)
+    if (m_chain.Tip()->nChainWork < m_chainman.MinimumChainWork()) {
         return true;
+    }
     if (m_chain.Tip()->Time() < NodeClock::now() - m_chainman.m_options.max_tip_age) {
         return true;
     }
@@ -2045,7 +2044,7 @@ bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state,
         if (it != m_blockman.m_block_index.end()) {
             if (it->second.GetAncestor(pindex->nHeight) == pindex &&
                 m_chainman.m_best_header->GetAncestor(pindex->nHeight) == pindex &&
-                m_chainman.m_best_header->nChainWork >= nMinimumChainWork) {
+                m_chainman.m_best_header->nChainWork >= m_chainman.MinimumChainWork()) {
                 // This block is a member of the assumed verified chain and an ancestor of the best header.
                 // Script verification is skipped when connecting blocks under the
                 // assumevalid block. Assuming the assumevalid block is valid this
@@ -2058,7 +2057,7 @@ bool Chainstate::ConnectBlock(const CBlock& block, BlockValidationState& state,
                 //  it hard to hide the implication of the demand.  This also avoids having release candidates
                 //  that are hardly doing any signature verification at all in testing without having to
                 //  artificially set the default assumed verified block further back.
-                // The test against nMinimumChainWork prevents the skipping when denied access to any chain at
+                // The test against the minimum chain work prevents the skipping when denied access to any chain at
                 //  least as good as the expected chain.
                 fScriptChecks = (GetBlockProofEquivalentTime(*m_chainman.m_best_header, *pindex, *m_chainman.m_best_header, m_params.GetConsensus()) <= 60 * 60 * 24 * 7 * 2);
             }
@@ -3843,7 +3842,7 @@ bool Chainstate::AcceptBlock(const std::shared_ptr<const CBlock>& pblock, BlockV
         // If our tip is behind, a peer could try to send us
         // low-work blocks on a fake chain that we would never
         // request; don't process these.
-        if (pindex->nChainWork < nMinimumChainWork) return true;
+        if (pindex->nChainWork < m_chainman.MinimumChainWork()) return true;
     }
 
     if (!CheckBlock(block, state, m_params.GetConsensus()) ||
@@ -5250,6 +5249,7 @@ void ChainstateManager::ResetChainstates()
  */
 static ChainstateManager::Options&& Flatten(ChainstateManager::Options&& opts)
 {
+    if (!opts.minimum_chain_work.has_value()) opts.minimum_chain_work = UintToArith256(opts.chainparams.GetConsensus().nMinimumChainWork);
     if (!opts.assumed_valid_block.has_value()) opts.assumed_valid_block = opts.chainparams.GetConsensus().defaultAssumeValid;
     Assert(opts.adjusted_time_callback);
     return std::move(opts);
diff --git a/src/validation.h b/src/validation.h
index 0483edaff3..495618549a 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -99,9 +99,6 @@ extern bool g_parallel_script_checks;
 extern bool fCheckBlockIndex;
 extern bool fCheckpointsEnabled;
 
-/** Minimum work we will assume exists on some valid chain. */
-extern arith_uint256 nMinimumChainWork;
-
 /** Documentation for argument 'checklevel'. */
 extern const std::vector<std::string> CHECKLEVEL_DOC;
 
@@ -865,6 +862,7 @@ public:
 
     const CChainParams& GetParams() const { return m_options.chainparams; }
     const Consensus::Params& GetConsensus() const { return m_options.chainparams.GetConsensus(); }
+    const arith_uint256& MinimumChainWork() const { return *Assert(m_options.minimum_chain_work); }
     const uint256& AssumedValidBlock() const { return *Assert(m_options.assumed_valid_block); }
 
     /**