Merge bitmonero@monero-project

12 files changed, 186 insertions, 81 deletions

diff --git a/src/cryptonote_core/blockchain_storage.cpp b/src/cryptonote_core/blockchain_storage.cpp
index 0e20b454b..9e9c77e85 100644
--- a/src/cryptonote_core/blockchain_storage.cpp
+++ b/src/cryptonote_core/blockchain_storage.cpp
@@ -372,7 +372,7 @@ bool blockchain_storage::rollback_blockchain_switching(std::list<block>& origina
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::iterator>& alt_chain)
+bool blockchain_storage::switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::iterator>& alt_chain, bool discard_disconnected_chain)
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   CHECK_AND_ASSERT_MES(alt_chain.size(), false, "switch_to_alternative_blockchain: empty chain passed");
@@ -414,16 +414,19 @@ bool blockchain_storage::switch_to_alternative_blockchain(std::list<blocks_ext_b
     }
   }
 
-  //pushing old chain as alternative chain
-  BOOST_FOREACH(auto& old_ch_ent, disconnected_chain)
+  if(!discard_disconnected_chain)
   {
-    block_verification_context bvc = boost::value_initialized<block_verification_context>();
-    bool r = handle_alternative_block(old_ch_ent, get_block_hash(old_ch_ent), bvc);
-    if(!r)
+    //pushing old chain as alternative chain
+    BOOST_FOREACH(auto& old_ch_ent, disconnected_chain)
     {
-      LOG_ERROR("Failed to push ex-main chain blocks to alternative chain ");
-      rollback_blockchain_switching(disconnected_chain, split_height);
-      return false;
+      block_verification_context bvc = boost::value_initialized<block_verification_context>();
+      bool r = handle_alternative_block(old_ch_ent, get_block_hash(old_ch_ent), bvc);
+      if(!r)
+      {
+        LOG_ERROR("Failed to push ex-main chain blocks to alternative chain ");
+        rollback_blockchain_switching(disconnected_chain, split_height);
+        return false;
+      }
     }
   }
 
@@ -701,6 +704,22 @@ bool blockchain_storage::handle_alternative_block(const block& b, const crypto::
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
+  uint64_t block_height = get_block_height(b);
+  if(0 == block_height)
+  {
+    LOG_ERROR("Block with id: " << string_tools::pod_to_hex(id) << " (as alternative) have wrong miner transaction");
+    bvc.m_verifivation_failed = true;
+    return false;
+  }
+  if (!m_checkpoints.is_alternative_block_allowed(get_current_blockchain_height(), block_height))
+  {
+    LOG_PRINT_RED_L0("Block with id: " << id
+      << ENDL << " can't be accepted for alternative chain, block height: " << block_height
+      << ENDL << " blockchain height: " << get_current_blockchain_height());
+    bvc.m_verifivation_failed = true;
+    return false;
+  }
+
   //block is not related with head of main chain
   //first of all - look in alternative chains container
   auto it_main_prev = m_blocks_index.find(b.prev_id);
@@ -746,31 +765,28 @@ bool blockchain_storage::handle_alternative_block(const block& b, const crypto::
     block_extended_info bei = boost::value_initialized<block_extended_info>();
     bei.bl = b;
     bei.height = alt_chain.size() ? it_prev->second.height + 1 : it_main_prev->second + 1;
+
+    bool is_a_checkpoint;
+    if(!m_checkpoints.check_block(bei.height, id, is_a_checkpoint))
+    {
+      LOG_ERROR("CHECKPOINT VALIDATION FAILED");
+      bvc.m_verifivation_failed = true;
+      return false;
+    }
+
+    // Always check PoW for alternative blocks
+    m_is_in_checkpoint_zone = false;
     difficulty_type current_diff = get_next_difficulty_for_alternative_chain(alt_chain, bei);
     CHECK_AND_ASSERT_MES(current_diff, false, "!!!!!!! DIFFICULTY OVERHEAD !!!!!!!");
     crypto::hash proof_of_work = null_hash;
-    if(!m_checkpoints.is_in_checkpoint_zone(bei.height))
+    get_block_longhash(bei.bl, proof_of_work, bei.height);
+    if(!check_hash(proof_of_work, current_diff))
     {
-      m_is_in_checkpoint_zone = false;
-      get_block_longhash(bei.bl, proof_of_work, bei.height);
-
-      if(!check_hash(proof_of_work, current_diff))
-      {
-        LOG_PRINT_RED_L0("Block with id: " << id
-          << ENDL << " for alternative chain, have not enough proof of work: " << proof_of_work
-          << ENDL << " expected difficulty: " << current_diff);
-        bvc.m_verifivation_failed = true;
-        return false;
-      }
-    }else
-    {
-      m_is_in_checkpoint_zone = true;
-      if(!m_checkpoints.check_block(bei.height, id))
-      {
-        LOG_ERROR("CHECKPOINT VALIDATION FAILED");
-        bvc.m_verifivation_failed = true;
-        return false;
-      }
+      LOG_PRINT_RED_L0("Block with id: " << id
+        << ENDL << " for alternative chain, have not enough proof of work: " << proof_of_work
+        << ENDL << " expected difficulty: " << current_diff);
+      bvc.m_verifivation_failed = true;
+      return false;
     }
 
     if(!prevalidate_miner_transaction(b, bei.height))
@@ -792,22 +808,33 @@ bool blockchain_storage::handle_alternative_block(const block& b, const crypto::
     auto i_res = m_alternative_chains.insert(blocks_ext_by_hash::value_type(id, bei));
     CHECK_AND_ASSERT_MES(i_res.second, false, "insertion of new alternative block returned as it already exist");
     alt_chain.push_back(i_res.first);
-    //check if difficulty bigger then in main chain
-    if(m_blocks.back().cumulative_difficulty < bei.cumulative_difficulty)
+
+    if(is_a_checkpoint)
     {
       //do reorganize!
-      LOG_PRINT_GREEN("###### REORGANIZE on height: " << alt_chain.front()->second.height << " of " << m_blocks.size() -1  << " with cum_difficulty " << m_blocks.back().cumulative_difficulty
+      LOG_PRINT_GREEN("###### REORGANIZE on height: " << alt_chain.front()->second.height << " of " << m_blocks.size() - 1 <<
+        ", checkpoint is found in alternative chain on height " << bei.height, LOG_LEVEL_0);
+      bool r = switch_to_alternative_blockchain(alt_chain, true);
+      if(r) bvc.m_added_to_main_chain = true;
+      else bvc.m_verifivation_failed = true;
+      return r;
+    }else if(m_blocks.back().cumulative_difficulty < bei.cumulative_difficulty) //check if difficulty bigger then in main chain
+    {
+      //do reorganize!
+      LOG_PRINT_GREEN("###### REORGANIZE on height: " << alt_chain.front()->second.height << " of " << m_blocks.size() - 1 << " with cum_difficulty " << m_blocks.back().cumulative_difficulty
         << ENDL << " alternative blockchain size: " << alt_chain.size() << " with cum_difficulty " << bei.cumulative_difficulty, LOG_LEVEL_0);
-      bool r = switch_to_alternative_blockchain(alt_chain);
+      bool r = switch_to_alternative_blockchain(alt_chain, false);
       if(r) bvc.m_added_to_main_chain = true;
       else bvc.m_verifivation_failed = true;
       return r;
+    }else
+    {
+      LOG_PRINT_BLUE("----- BLOCK ADDED AS ALTERNATIVE ON HEIGHT " << bei.height
+        << ENDL << "id:\t" << id
+        << ENDL << "PoW:\t" << proof_of_work
+        << ENDL << "difficulty:\t" << current_diff, LOG_LEVEL_0);
+      return true;
     }
-    LOG_PRINT_BLUE("----- BLOCK ADDED AS ALTERNATIVE ON HEIGHT " << bei.height
-      << ENDL << "id:\t" << id
-      << ENDL << "PoW:\t" << proof_of_work
-      << ENDL << "difficulty:\t" << current_diff, LOG_LEVEL_0);
-    return true;
   }else
   {
     //block orphaned
@@ -815,7 +842,6 @@ bool blockchain_storage::handle_alternative_block(const block& b, const crypto::
     LOG_PRINT_RED_L0("Block recognized as orphaned and rejected, id = " << id);
   }
 
-
   return true;
 }
 //------------------------------------------------------------------
@@ -1480,19 +1506,27 @@ bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypt
   TIME_MEASURE_FINISH(target_calculating_time);
   TIME_MEASURE_START(longhash_calculating_time);
   crypto::hash proof_of_work = null_hash;
-  if(!m_checkpoints.is_in_checkpoint_zone(get_current_blockchain_height()))
+
+  // Formerly the code below contained an if loop with the following condition
+  // !m_checkpoints.is_in_checkpoint_zone(get_current_blockchain_height())
+  // however, this caused the daemon to not bother checking PoW for blocks
+  // before checkpoints, which is very dangerous behaviour. We moved the PoW
+  // validation out of the next chunk of code to make sure that we correctly
+  // check PoW now.
+  proof_of_work = get_block_longhash(bl, m_blocks.size());
+
+  if(!check_hash(proof_of_work, current_diffic))
   {
-    proof_of_work = get_block_longhash(bl, m_blocks.size());
+    LOG_PRINT_L0("Block with id: " << id << ENDL
+      << "have not enough proof of work: " << proof_of_work << ENDL
+      << "nexpected difficulty: " << current_diffic );
+    bvc.m_verifivation_failed = true;
+    return false;
+  }
 
-    if(!check_hash(proof_of_work, current_diffic))
-    {
-      LOG_PRINT_L0("Block with id: " << id << ENDL
-        << "have not enough proof of work: " << proof_of_work << ENDL
-        << "nexpected difficulty: " << current_diffic );
-      bvc.m_verifivation_failed = true;
-      return false;
-    }
-  }else
+  // If we're at a checkpoint, ensure that our hardcoded checkpoint hash
+  // is correct.
+  if(m_checkpoints.is_in_checkpoint_zone(get_current_blockchain_height()))
   {
     if(!m_checkpoints.check_block(get_current_blockchain_height(), id))
     {
@@ -1501,6 +1535,7 @@ bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypt
       return false;
     }
   }
+
   TIME_MEASURE_FINISH(longhash_calculating_time);
 
   if(!prevalidate_miner_transaction(bl, m_blocks.size()))
@@ -1648,4 +1683,4 @@ bool blockchain_storage::add_new_block(const block& bl_, block_verification_cont
   }
 
   return handle_block_to_main_chain(bl, id, bvc);
-}
\ No newline at end of file
+}
diff --git a/src/cryptonote_core/blockchain_storage.h b/src/cryptonote_core/blockchain_storage.h
index 1ea5e29ea..b1fb5df41 100644
--- a/src/cryptonote_core/blockchain_storage.h
+++ b/src/cryptonote_core/blockchain_storage.h
@@ -13,6 +13,8 @@
 #include <boost/foreach.hpp>
 #include <atomic>
 
+#include "syncobj.h"
+#include "string_tools.h"
 #include "tx_pool.h"
 #include "cryptonote_basic.h"
 #include "common/util.h"
@@ -50,7 +52,7 @@ namespace cryptonote
       uint64_t already_generated_coins;
     };
 
-    blockchain_storage(tx_memory_pool& tx_pool):m_tx_pool(tx_pool), m_current_block_cumul_sz_limit(0), m_is_in_checkpoint_zone(false)
+    blockchain_storage(tx_memory_pool& tx_pool):m_tx_pool(tx_pool), m_current_block_cumul_sz_limit(0), m_is_in_checkpoint_zone(false), m_is_blockchain_storing(false)
     {};
 
     bool init() { return init(tools::get_default_data_dir()); }
@@ -119,7 +121,7 @@ namespace cryptonote
           missed_bs.push_back(bl_id);
         else
         {
-          CHECK_AND_ASSERT_MES(it->second < m_blocks.size(), false, "Internal error: bl_id=" << string_tools::pod_to_hex(bl_id)
+          CHECK_AND_ASSERT_MES(it->second < m_blocks.size(), false, "Internal error: bl_id=" << epee::string_tools::pod_to_hex(bl_id)
             << " have index record with offset="<<it->second<< ", bigger then m_blocks.size()=" << m_blocks.size());
             blocks.push_back(m_blocks[it->second].bl);
         }
@@ -163,7 +165,7 @@ namespace cryptonote
     typedef std::map<uint64_t, std::vector<std::pair<crypto::hash, size_t>>> outputs_container; //crypto::hash - tx hash, size_t - index of out in transaction
 
     tx_memory_pool& m_tx_pool;
-    critical_section m_blockchain_lock; // TODO: add here reader/writer lock
+    epee::critical_section m_blockchain_lock; // TODO: add here reader/writer lock
 
     // main chain
     blocks_container m_blocks;               // height  -> block_extended_info
@@ -186,7 +188,7 @@ namespace cryptonote
     std::atomic<bool> m_is_in_checkpoint_zone;
     std::atomic<bool> m_is_blockchain_storing;
 
-    bool switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::iterator>& alt_chain);
+    bool switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::iterator>& alt_chain, bool discard_disconnected_chain);
     bool pop_block_from_blockchain();
     bool purge_block_data_from_blockchain(const block& b, size_t processed_tx_count);
     bool purge_transaction_from_blockchain(const crypto::hash& tx_id);
@@ -301,7 +303,7 @@ namespace cryptonote
         return false;
       }
       transactions_container::iterator tx_it = m_transactions.find(amount_outs_vec[i].first);
-      CHECK_AND_ASSERT_MES(tx_it != m_transactions.end(), false, "Wrong transaction id in output indexes: " <<string_tools::pod_to_hex(amount_outs_vec[i].first));
+      CHECK_AND_ASSERT_MES(tx_it != m_transactions.end(), false, "Wrong transaction id in output indexes: " << epee::string_tools::pod_to_hex(amount_outs_vec[i].first));
       CHECK_AND_ASSERT_MES(amount_outs_vec[i].second < tx_it->second.tx.vout.size(), false,
         "Wrong index in transaction outputs: " << amount_outs_vec[i].second << ", expected less then " << tx_it->second.tx.vout.size());
       if(!vis.handle_output(tx_it->second.tx, tx_it->second.tx.vout[amount_outs_vec[i].second]))
diff --git a/src/cryptonote_core/checkpoints.cpp b/src/cryptonote_core/checkpoints.cpp
index 54c2f3a6d..33a2d2986 100644
--- a/src/cryptonote_core/checkpoints.cpp
+++ b/src/cryptonote_core/checkpoints.cpp
@@ -29,10 +29,11 @@ namespace cryptonote
     return !m_points.empty() && (height <= (--m_points.end())->first);
   }
   //---------------------------------------------------------------------------
-  bool checkpoints::check_block(uint64_t height, const crypto::hash& h) const
+  bool checkpoints::check_block(uint64_t height, const crypto::hash& h, bool& is_a_checkpoint) const
   {
     auto it = m_points.find(height);
-    if(it == m_points.end())
+    is_a_checkpoint = it != m_points.end();
+    if(!is_a_checkpoint)
       return true;
 
     if(it->second == h)
@@ -45,4 +46,25 @@ namespace cryptonote
       return false;
     }
   }
+  //---------------------------------------------------------------------------
+  bool checkpoints::check_block(uint64_t height, const crypto::hash& h) const
+  {
+    bool ignored;
+    return check_block(height, h, ignored);
+  }
+  //---------------------------------------------------------------------------
+  bool checkpoints::is_alternative_block_allowed(uint64_t blockchain_height, uint64_t block_height) const
+  {
+    if (0 == block_height)
+      return false;
+
+    auto it = m_points.upper_bound(blockchain_height);
+    // Is blockchain_height before the first checkpoint?
+    if (it == m_points.begin())
+      return true;
+
+    --it;
+    uint64_t checkpoint_height = it->first;
+    return checkpoint_height < block_height;
+  }
 }
diff --git a/src/cryptonote_core/checkpoints.h b/src/cryptonote_core/checkpoints.h
index 20014b1c8..1bc055d91 100644
--- a/src/cryptonote_core/checkpoints.h
+++ b/src/cryptonote_core/checkpoints.h
@@ -16,6 +16,9 @@ namespace cryptonote
     bool add_checkpoint(uint64_t height, const std::string& hash_str);
     bool is_in_checkpoint_zone(uint64_t height) const;
     bool check_block(uint64_t height, const crypto::hash& h) const;
+    bool check_block(uint64_t height, const crypto::hash& h, bool& is_a_checkpoint) const;
+    bool is_alternative_block_allowed(uint64_t blockchain_height, uint64_t block_height) const;
+
   private:
     std::map<uint64_t, crypto::hash> m_points;
   };
diff --git a/src/cryptonote_core/checkpoints_create.h b/src/cryptonote_core/checkpoints_create.h
index 32d15831f..3ecbbf0b6 100644
--- a/src/cryptonote_core/checkpoints_create.h
+++ b/src/cryptonote_core/checkpoints_create.h
@@ -12,12 +12,9 @@
 namespace cryptonote {
   inline bool create_checkpoints(cryptonote::checkpoints& checkpoints)
   {      
-    // Checkpointing disabled until we can make the client not fast-sync
-    // without checking PoW at some point. Otherwise we may be exposed
-    // to blockchain corruption attacks. Need to investigate this further.
-    // 8-5-14
-    // ADD_CHECKPOINT(22231, "7cb10e29d67e1c069e6e11b17d30b809724255fee2f6868dc14cfc6ed44dfb25");
-    // ADD_CHECKPOINT(29556, "53c484a8ed91e4da621bb2fa88106dbde426fe90d7ef07b9c1e5127fb6f3a7f6");
+    ADD_CHECKPOINT(22231, "7cb10e29d67e1c069e6e11b17d30b809724255fee2f6868dc14cfc6ed44dfb25");
+    ADD_CHECKPOINT(29556, "53c484a8ed91e4da621bb2fa88106dbde426fe90d7ef07b9c1e5127fb6f3a7f6");
+    ADD_CHECKPOINT(50000, "0fe8758ab06a8b9cb35b7328fd4f757af530a5d37759f9d3e421023231f7b31c");
     return true;
   }
 }
diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index a09f25d31..b6bfa09c8 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -502,7 +502,7 @@ namespace cryptonote
       LOG_PRINT_L0(ENDL << "**********************************************************************" << ENDL 
         << "The daemon will start synchronizing with the network. It may take up to several hours." << ENDL 
         << ENDL
-        << "You can set the level of process detailization by using command \"set_log <level>\", where <level> is either 0 (no details), 1 (current block height synchronized), or 2 (all details)." << ENDL
+        << "You can set the level of process detailization* through \"set_log <level>\" command*, where <level> is between 0 (no details) and 4 (very verbose)." << ENDL
         << ENDL
         << "Use \"help\" command to see the list of available commands." << ENDL
         << ENDL
diff --git a/src/cryptonote_core/cryptonote_core.h b/src/cryptonote_core/cryptonote_core.h
index c298451e8..cde52d5a2 100644
--- a/src/cryptonote_core/cryptonote_core.h
+++ b/src/cryptonote_core/cryptonote_core.h
@@ -115,13 +115,13 @@ namespace cryptonote
      tx_memory_pool m_mempool;
      blockchain_storage m_blockchain_storage;
      i_cryptonote_protocol* m_pprotocol;
-     critical_section m_incoming_tx_lock;
+     epee::critical_section m_incoming_tx_lock;
      //m_miner and m_miner_addres are probably temporary here
      miner m_miner;
      account_public_address m_miner_address;
      std::string m_config_folder;
      cryptonote_protocol_stub m_protocol_stub;
-     math_helper::once_a_time_seconds<60*60*12, false> m_store_blockchain_interval;
+     epee::math_helper::once_a_time_seconds<60*60*12, false> m_store_blockchain_interval;
      friend class tx_validate_inputs;
      std::atomic<bool> m_starter_message_showed;
    };
diff --git a/src/cryptonote_core/cryptonote_format_utils.cpp b/src/cryptonote_core/cryptonote_format_utils.cpp
index 2b38d001f..7b7f18844 100644
--- a/src/cryptonote_core/cryptonote_format_utils.cpp
+++ b/src/cryptonote_core/cryptonote_format_utils.cpp
@@ -239,8 +239,7 @@ namespace cryptonote
   crypto::public_key get_tx_pub_key_from_extra(const std::vector<uint8_t>& tx_extra)
   {
     std::vector<tx_extra_field> tx_extra_fields;
-    if (!parse_tx_extra(tx_extra, tx_extra_fields))
-      return null_pkey;
+    parse_tx_extra(tx_extra, tx_extra_fields);
 
     tx_extra_pub_key pub_key_field;
     if(!find_tx_extra_field_by_type(tx_extra_fields, pub_key_field))
diff --git a/src/cryptonote_core/miner.h b/src/cryptonote_core/miner.h
index f1e4e5dce..d9ac5a501 100644
--- a/src/cryptonote_core/miner.h
+++ b/src/cryptonote_core/miner.h
@@ -4,7 +4,6 @@
 
 #pragma once 
 
-#include <boost/atomic.hpp>
 #include <boost/program_options.hpp>
 #include <atomic>
 #include "cryptonote_basic.h"
@@ -66,7 +65,7 @@ namespace cryptonote
 
 
     volatile uint32_t m_stop;
-    ::critical_section m_template_lock;
+    epee::critical_section m_template_lock;
     block m_template;
     std::atomic<uint32_t> m_template_no;
     std::atomic<uint32_t> m_starter_nonce;
@@ -75,21 +74,21 @@ namespace cryptonote
     volatile uint32_t m_thread_index; 
     volatile uint32_t m_threads_total;
     std::atomic<int32_t> m_pausers_count;
-    ::critical_section m_miners_count_lock;
+    epee::critical_section m_miners_count_lock;
 
     std::list<boost::thread> m_threads;
-    ::critical_section m_threads_lock;
+    epee::critical_section m_threads_lock;
     i_miner_handler* m_phandler;
     account_public_address m_mine_address;
-    math_helper::once_a_time_seconds<5> m_update_block_template_interval;
-    math_helper::once_a_time_seconds<2> m_update_merge_hr_interval;
+    epee::math_helper::once_a_time_seconds<5> m_update_block_template_interval;
+    epee::math_helper::once_a_time_seconds<2> m_update_merge_hr_interval;
     std::vector<blobdata> m_extra_messages;
     miner_config m_config;
     std::string m_config_folder_path;    
     std::atomic<uint64_t> m_last_hr_merge_time;
     std::atomic<uint64_t> m_hashes;
     std::atomic<uint64_t> m_current_hash_rate;
-    critical_section m_last_hash_rates_lock;
+    epee::critical_section m_last_hash_rates_lock;
     std::list<uint64_t> m_last_hash_rates;
     bool m_do_print_hashrate;
     bool m_do_mining;
diff --git a/src/cryptonote_core/tx_extra.h b/src/cryptonote_core/tx_extra.h
index 254a6a2ff..37a04a41e 100644
--- a/src/cryptonote_core/tx_extra.h
+++ b/src/cryptonote_core/tx_extra.h
@@ -135,7 +135,6 @@ namespace cryptonote
   //   varint tag;
   //   varint size;
   //   varint data[];
-  //typedef boost::variant<tx_extra_padding, tx_extra_pub_key, tx_extra_nonce> tx_extra_field;
   typedef boost::variant<tx_extra_padding, tx_extra_pub_key, tx_extra_nonce, tx_extra_merge_mining_tag> tx_extra_field;
 }
 
diff --git a/src/cryptonote_core/tx_pool.cpp b/src/cryptonote_core/tx_pool.cpp
index 24e5752ad..4c4c6aea1 100644
--- a/src/cryptonote_core/tx_pool.cpp
+++ b/src/cryptonote_core/tx_pool.cpp
@@ -350,18 +350,69 @@ namespace cryptonote
   //---------------------------------------------------------------------------------
   bool tx_memory_pool::fill_block_template(block &bl, size_t median_size, uint64_t already_generated_coins, size_t &total_size, uint64_t &fee)
   {
+    // Warning: This function takes already_generated_
+    // coins as an argument and appears to do nothing
+    // with it.
+
     CRITICAL_REGION_LOCAL(m_transactions_lock);
 
     total_size = 0;
     fee = 0;
 
-    size_t max_total_size = 2 * median_size - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE;
+    size_t max_total_size = 2 * median_size - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE; // Max block size
     std::unordered_set<crypto::key_image> k_images;
+
+    // Tx size limit as in wallet2.h
+    // tx_pool.cpp uses size_t for tx sizes, whereas
+    // wallet2.h uses uint64_t; just use size_t here 
+    // for now
+    size_t upper_transaction_size_limit = ((CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE * 125) / 100) - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE;
+
+    // Calculate size limit based on median too; useful
+    // for when we actually fix wallet2.h's maximum
+    // allowable tx size
+    //
+    // Can be removed when wallet2.h calculates max
+    // tx size based on the median too; just use
+    // upper_transaction_size_limit_median in all cases
+    size_t upper_transaction_size_limit_median = ((median_size * 125) / 100) - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE;
+    if (upper_transaction_size_limit_median > upper_transaction_size_limit)
+      upper_transaction_size_limit = upper_transaction_size_limit_median;
+
     BOOST_FOREACH(transactions_container::value_type& tx, m_transactions)
     {
+      // Can not exceed maximum block size
       if (max_total_size < total_size + tx.second.blob_size)
         continue;
 
+      // Check to see if the minimum fee is included;
+      // exclude tx missing minimum fee
+      if (tx.second.fee < DEFAULT_FEE)
+        continue;
+
+      // Skip transactions that are too large
+      // TODO: Correct upper_transactions_size_limit
+      // such that it is based on median block size;
+      // We need to make a similar patch for
+      // wallet2.h
+      if (tx.second.blob_size > upper_transaction_size_limit)
+        continue;
+
+      // If adding this tx will make the block size
+      // greater than 130% of the median, reject the
+      // tx; this will keep down largely punitive tx
+      // from being included
+      if ( (total_size + tx.second.blob_size) > ((130 * median_size) / 100) )
+        continue;
+
+      // If we've exceeded the penalty free size,
+      // stop including more tx
+      if (total_size > median_size)
+        break;      
+
+      // Skip transactions that are not ready to be
+      // included into the blockchain or that are
+      // missing key images
       if (!is_transaction_ready_to_go(tx.second) || have_key_images(k_images, tx.second.tx))
         continue;
 
diff --git a/src/cryptonote_core/tx_pool.h b/src/cryptonote_core/tx_pool.h
index 3978dfb96..26d273aa7 100644
--- a/src/cryptonote_core/tx_pool.h
+++ b/src/cryptonote_core/tx_pool.h
@@ -4,8 +4,6 @@
 
 #pragma once
 #include "include_base_utils.h"
-using namespace epee;
-
 
 #include <set>
 #include <unordered_map>