1 files changed, 80 insertions, 0 deletions
diff --git a/src/cryptonote_core/blockchain_storage.cpp b/src/cryptonote_core/blockchain_storage.cpp
index e664a39c5..6f1b4121c 100644
--- a/src/cryptonote_core/blockchain_storage.cpp
+++ b/src/cryptonote_core/blockchain_storage.cpp
@@ -47,6 +47,7 @@
 #include "common/boost_serialization_helper.h"
 #include "warnings.h"
 #include "crypto/hash.h"
+#include "cryptonote_core/checkpoints_create.h"
 //#include "serialization/json_archive.h"
 
 using namespace cryptonote;
@@ -441,6 +442,13 @@ difficulty_type blockchain_storage::get_difficulty_for_next_block()
 bool blockchain_storage::rollback_blockchain_switching(std::list<block>& original_chain, size_t rollback_height)
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  // fail if rollback_height passed is too high
+  if (rollback_height > m_blocks.size())
+  {
+    return true;
+  }
+
   //remove failed subchain
   for(size_t i = m_blocks.size()-1; i >=rollback_height; i--)
   {
@@ -1773,3 +1781,75 @@ bool blockchain_storage::add_new_block(const block& bl_, block_verification_cont
 
   return handle_block_to_main_chain(bl, id, bvc);
 }
+//------------------------------------------------------------------
+void blockchain_storage::check_against_checkpoints(checkpoints& points, bool enforce)
+{
+  const auto& pts = points.get_points();
+
+  for (const auto& pt : pts)
+  {
+    // if the checkpoint is for a block we don't have yet, move on
+    if (pt.first >= m_blocks.size())
+    {
+      continue;
+    }
+
+    if (!m_checkpoints.check_block(pt.first, get_block_hash(m_blocks[pt.first].bl)))
+    {
+      // if asked to enforce checkpoints, roll back to a couple of blocks before the checkpoint
+      if (enforce)
+      {
+	LOG_ERROR("Checkpoint failed when adding new checkpoints, rolling back!");
+	std::list<block> empty;
+	rollback_blockchain_switching(empty, pt.first - 2);
+      }
+      else
+      {
+	LOG_ERROR("Checkpoint failed when adding new checkpoints, this could be very bad.");
+      }
+    }
+  }
+}
+//------------------------------------------------------------------
+// returns false if any of the checkpoints loading returns false.
+// That should happen only if a checkpoint is added that conflicts
+// with an existing checkpoint.
+bool blockchain_storage::update_checkpoints(const std::string& file_path, bool check_dns)
+{
+  if (!cryptonote::load_checkpoints_from_json(m_checkpoints, file_path))
+  {
+    return false;
+  }
+
+  // if we're checking both dns and json, load checkpoints from dns.
+  // if we're not hard-enforcing dns checkpoints, handle accordingly
+  if (m_enforce_dns_checkpoints && check_dns)
+  {
+    if (!cryptonote::load_checkpoints_from_dns(m_checkpoints))
+    {
+      return false;
+    }
+  }
+  else if (check_dns)
+  {
+    checkpoints dns_points;
+    cryptonote::load_checkpoints_from_dns(dns_points);
+    if (m_checkpoints.check_for_conflicts(dns_points))
+    {
+      check_against_checkpoints(dns_points, false);
+    }
+    else
+    {
+      LOG_PRINT_L0("One or more checkpoints fetched from DNS conflicted with existing checkpoints!");
+    }
+  }
+
+  check_against_checkpoints(m_checkpoints, true);
+
+  return true;
+}
+//------------------------------------------------------------------
+void blockchain_storage::set_enforce_dns_checkpoints(bool enforce_checkpoints)
+{
+  m_enforce_dns_checkpoints = enforce_checkpoints;
+}