Staking weight incorporation (#1264)

libs/ledger/include/ledger/chain/block.hpp

@@ -68,9 +68,11 @@ class Block
   Proof    proof;     ///< The consensus proof
   /// @}
 
+  // TODO(HUT): This should be part of body since it's no longer going to be metadata
+  uint64_t weight = 1;
+
   /// @name Metadata for block management
   /// @{
-  uint64_t weight       = 1;
   uint64_t total_weight = 1;
   bool     is_loose     = false;
   /// @}

libs/ledger/include/ledger/consensus/stake_manager.hpp

@@ -29,7 +29,7 @@ namespace ledger {
 class StakeSnapshot;
 class EntropyGeneratorInterface;
 
-class StakeManager : public StakeManagerInterface
+class StakeManager final : public StakeManagerInterface
 {
 public:
   using Committee    = std::vector<Address>;
@@ -46,6 +46,7 @@ class StakeManager : public StakeManagerInterface
   void        UpdateCurrentBlock(Block const &current) override;
   std::size_t GetBlockGenerationWeight(Block const &previous, Address const &address) override;
   bool        ShouldGenerateBlock(Block const &previous, Address const &address) override;
+  bool        ValidMinerForBlock(Block const &previous, Address const &address) override;
   /// @}
 
   // Accessors

libs/ledger/include/ledger/consensus/stake_manager_interface.hpp

@@ -39,6 +39,7 @@ class StakeManagerInterface
   virtual void        UpdateCurrentBlock(Block const &current)                                = 0;
   virtual std::size_t GetBlockGenerationWeight(Block const &previous, Address const &address) = 0;
   virtual bool        ShouldGenerateBlock(Block const &previous, Address const &address)      = 0;
+  virtual bool        ValidMinerForBlock(Block const &previous, Address const &address)       = 0;
   /// @}
 
 private:

libs/ledger/src/chain/block_coordinator.cpp

@@ -417,6 +417,11 @@ BlockCoordinator::State BlockCoordinator::OnSynchronised(State current, State pr
     next_block_->body.block_number  = current_block_->body.block_number + 1;
     next_block_->body.miner         = mining_address_;
 
+    if (stake_)
+    {
+      next_block_->weight = stake_->GetBlockGenerationWeight(*current_block_, mining_address_);
+    }
+
     // Attach current DAG state
     if (dag_)
     {
@@ -469,6 +474,21 @@ BlockCoordinator::State BlockCoordinator::OnPreExecBlockValidation()
       return fail("No previous block in chain");
     }
 
+    // Check that the weight as given by the proof is correct
+    if (stake_)
+    {
+      if (!stake_->ValidMinerForBlock(*previous, current_block_->body.miner))
+      {
+        return fail("Block signed by miner deemed invalid by the staking mechanism");
+      }
+
+      if (current_block_->weight !=
+          stake_->GetBlockGenerationWeight(*previous, current_block_->body.miner))
+      {
+        return fail("Incorrect stake weight found for block");
+      }
+    }
+
     // Check: Ensure the block number is continuous
     uint64_t const expected_block_number = previous->body.block_number + 1u;
     if (expected_block_number != current_block_->body.block_number)

libs/ledger/src/chain/main_chain.cpp

@@ -106,13 +106,8 @@ BlockStatus MainChain::AddBlock(Block const &blk)
   // create a copy of the block
   auto block = std::make_shared<Block>(blk);
 
-  // update the weight based on the proof and the number of transactions
-  block->weight       = 1;
+  // At this point we assume that the weight has been correctly set by the miner
   block->total_weight = 1;
-  for (auto const &slice : block->body.slices)
-  {
-    block->weight += slice.size();
-  }
 
   // pass the block to the
   auto const status = InsertBlock(block);

libs/ledger/src/consensus/stake_manager.cpp

@@ -176,5 +176,18 @@ void StakeManager::ResetInternal(StakeSnapshotPtr &&snapshot, std::size_t commit
   current_block_index_ = 0;
 }
 
+bool StakeManager::ValidMinerForBlock(Block const &previous, Address const &address)
+{
+  auto const committee = GetCommittee(previous);
+
+  if (!committee || committee->empty())
+  {
+    FETCH_LOG_WARN(LOGGING_NAME, "Unable to determine committee for block validation");
+    return false;
+  }
+
+  return std::find((*committee).begin(), (*committee).end(), address) != (*committee).end();
+}
+
 }  // namespace ledger
 }  // namespace fetch