Merge pull request #501

d887c18 hardfork: fix more major/minor issues (moneromooo-monero)
3b47ca2 hardfork: fix rescan on load (moneromooo-monero)
4cea2b1 Add IP blocking for misbehaving nodes (adapted from Boolberry) (Javier Smooth)
9c64b12 quiet down p2p logging a bit (Javier Smooth)
53c75ab blockchain: log versions as numbers, not characters (moneromooo-monero)
edade8d hardfork: fix actual/voting confusion (moneromooo-monero)

contrib/epee/include/net/abstract_tcp_server2.inl

@@ -899,9 +899,7 @@ POP_WARNINGS
         boost::bind(&boosted_tcp_server<t_protocol_handler>::handle_accept, this,
         boost::asio::placeholders::error));
 
-      bool r = conn->start(true, 1 < m_threads_count);
+      conn->start(true, 1 < m_threads_count);
-      if (!r)
-        _erro("[sock " << conn->socket().native_handle() << "] Failed to start connection, connections_count = " << m_sock_count);
       conn->save_dbg_log();
     }else
     {

src/cryptonote_config.h

@@ -105,6 +105,11 @@
 #define P2P_DEFAULT_HANDSHAKE_INVOKE_TIMEOUT            5000       //5 seconds
 #define P2P_DEFAULT_WHITELIST_CONNECTIONS_PERCENT       70
 
+#define P2P_FAILED_ADDR_FORGET_SECONDS                  (60*60)     //1 hour
+#define P2P_IP_BLOCKTIME                                (60*60*24)  //24 hour
+#define P2P_IP_FAILS_BEFORE_BLOCK                       10
+#define P2P_IDLE_CONNECTION_KILL_INTERVAL               (5*60) //5 minutes
+
 #define ALLOW_DEBUG_COMMANDS
 
 #define CRYPTONOTE_NAME                         "bitmonero"

src/cryptonote_core/blockchain.cpp

@@ -257,13 +257,13 @@ bool Blockchain::init(BlockchainDB* db, const bool testnet)
     if (testnet) {
       m_hardfork = new HardFork(*db, 1, testnet_hard_fork_version_1_till);
       for (size_t n = 0; n < sizeof(testnet_hard_forks) / sizeof(testnet_hard_forks[0]); ++n)
-        m_hardfork->add(testnet_hard_forks[n].version, testnet_hard_forks[n].height, testnet_hard_forks[n].threshold, testnet_hard_forks[n].time);
+        m_hardfork->add_fork(testnet_hard_forks[n].version, testnet_hard_forks[n].height, testnet_hard_forks[n].threshold, testnet_hard_forks[n].time);
     }
     else
     {
       m_hardfork = new HardFork(*db, 1, mainnet_hard_fork_version_1_till);
       for (size_t n = 0; n < sizeof(mainnet_hard_forks) / sizeof(mainnet_hard_forks[0]); ++n)
-        m_hardfork->add(mainnet_hard_forks[n].version, mainnet_hard_forks[n].height, mainnet_hard_forks[n].threshold, mainnet_hard_forks[n].time);
+        m_hardfork->add_fork(mainnet_hard_forks[n].version, mainnet_hard_forks[n].height, mainnet_hard_forks[n].threshold, mainnet_hard_forks[n].time);
     }
     m_hardfork->init();
 
@@ -2338,7 +2338,7 @@ bool Blockchain::handle_block_to_main_chain(const block& bl, const crypto::hash&
     // this is a cheap test
     if (!m_hardfork->check(bl))
     {
-        LOG_PRINT_L1("Block with id: " << id << std::endl << "has old version: " << bl.major_version << std::endl << "current: " << m_hardfork->get_current_version());
+        LOG_PRINT_L1("Block with id: " << id << std::endl << "has old version: " << (unsigned)bl.major_version << std::endl << "current: " << (unsigned)m_hardfork->get_current_version());
         return false;
     }
 

src/cryptonote_core/hardfork.cpp

@@ -46,6 +46,11 @@ static uint8_t get_block_vote(const cryptonote::block &b)
   return b.minor_version;
 }
 
+static uint8_t get_block_version(const cryptonote::block &b)
+{
+  return b.major_version;
+}
+
 HardFork::HardFork(cryptonote::BlockchainDB &db, uint8_t original_version, uint64_t original_version_till_height, time_t forked_time, time_t update_time, uint64_t window_size, uint8_t default_threshold_percent):
   db(db),
   original_version(original_version),
@@ -61,7 +66,7 @@ HardFork::HardFork(cryptonote::BlockchainDB &db, uint8_t original_version, uint6
     throw "default_threshold_percent needs to be between 0 and 100";
 }
 
-bool HardFork::add(uint8_t version, uint64_t height, uint8_t threshold, time_t time)
+bool HardFork::add_fork(uint8_t version, uint64_t height, uint8_t threshold, time_t time)
 {
   CRITICAL_REGION_LOCAL(lock);
 
@@ -82,42 +87,43 @@ bool HardFork::add(uint8_t version, uint64_t height, uint8_t threshold, time_t t
   return true;
 }
 
-bool HardFork::add(uint8_t version, uint64_t height, time_t time)
+bool HardFork::add_fork(uint8_t version, uint64_t height, time_t time)
 {
-  return add(version, height, default_threshold_percent, time);
+  return add_fork(version, height, default_threshold_percent, time);
 }
 
-uint8_t HardFork::get_effective_version(uint8_t version) const
+uint8_t HardFork::get_effective_version(uint8_t voting_version) const
 {
   if (!heights.empty()) {
     uint8_t max_version = heights.back().version;
-    if (version > max_version)
+    if (voting_version > max_version)
-      version = max_version;
+      voting_version = max_version;
   }
-  return version;
+  return voting_version;
 }
 
-bool HardFork::do_check(uint8_t version) const
+bool HardFork::do_check(uint8_t block_version, uint8_t voting_version) const
 {
-  return version >= heights[current_fork_index].version;
+  return block_version >= heights[current_fork_index].version
+      && voting_version >= heights[current_fork_index].version;
 }
 
 bool HardFork::check(const cryptonote::block &block) const
 {
   CRITICAL_REGION_LOCAL(lock);
-  return do_check(get_block_vote(block));
+  return do_check(::get_block_version(block), ::get_block_vote(block));
 }
 
-bool HardFork::add(uint8_t block_version, uint64_t height)
+bool HardFork::add(uint8_t block_version, uint8_t voting_version, uint64_t height)
 {
   CRITICAL_REGION_LOCAL(lock);
 
-  if (!do_check(block_version))
+  if (!do_check(block_version, voting_version))
     return false;
 
   db.set_hard_fork_version(height, heights[current_fork_index].version);
 
-  const uint8_t version = get_effective_version(block_version);
+  voting_version = get_effective_version(voting_version);
 
   while (versions.size() >= window_size) {
     const uint8_t old_version = versions.front();
@@ -126,8 +132,8 @@ bool HardFork::add(uint8_t block_version, uint64_t height)
     versions.pop_front();
   }
 
-  last_versions[version]++;
+  last_versions[voting_version]++;
-  versions.push_back(version);
+  versions.push_back(voting_version);
 
   uint8_t voted = get_voted_fork_index(height + 1);
   if (voted > current_fork_index) {
@@ -143,7 +149,7 @@ bool HardFork::add(uint8_t block_version, uint64_t height)
 
 bool HardFork::add(const cryptonote::block &block, uint64_t height)
 {
-  return add(get_block_vote(block), height);
+  return add(::get_block_version(block), ::get_block_vote(block), height);
 }
 
 void HardFork::init()
@@ -185,7 +191,7 @@ uint8_t HardFork::get_block_version(uint64_t height) const
     return original_version;
 
   const cryptonote::block &block = db.get_block_from_height(height);
-  return get_block_vote(block);
+  return ::get_block_version(block);
 }
 
 bool HardFork::reorganize_from_block_height(uint64_t height)
@@ -225,7 +231,7 @@ bool HardFork::reorganize_from_block_height(uint64_t height)
 
   const uint64_t bc_height = db.height();
   for (uint64_t h = height + 1; h < bc_height; ++h) {
-    add(get_block_version(h), h);
+    add(db.get_block_from_height(h), h);
   }
 
   db.batch_stop();
@@ -258,7 +264,7 @@ bool HardFork::rescan_from_block_height(uint64_t height)
     versions.push_back(v);
   }
 
-  uint8_t lastv = db.get_hard_fork_version(height);
+  uint8_t lastv = db.get_hard_fork_version(db.height() - 1);
   current_fork_index = 0;
   while (current_fork_index + 1 < heights.size() && heights[current_fork_index].version != lastv)
     ++current_fork_index;

src/cryptonote_core/hardfork.h

@@ -71,7 +71,7 @@ namespace cryptonote
      * @param threshold The threshold of votes needed for this fork (0-100)
      * @param time Approximate time of the hardfork (seconds since epoch)
      */
-    bool add(uint8_t version, uint64_t height, uint8_t threshold, time_t time);
+    bool add_fork(uint8_t version, uint64_t height, uint8_t threshold, time_t time);
 
     /**
      * @brief add a new hardfork height
@@ -79,10 +79,11 @@ namespace cryptonote
      * returns true if no error, false otherwise
      *
      * @param version the major block version for the fork
+     * @param voting_version the minor block version for the fork, used for voting
      * @param height The height the hardfork takes effect
      * @param time Approximate time of the hardfork (seconds since epoch)
      */
-    bool add(uint8_t version, uint64_t height, time_t time);
+    bool add_fork(uint8_t version, uint64_t height, time_t time);
 
     /**
      * @brief initialize the object
@@ -203,10 +204,10 @@ namespace cryptonote
   private:
 
     uint8_t get_block_version(uint64_t height) const;
-    bool do_check(uint8_t version) const;
+    bool do_check(uint8_t block_version, uint8_t voting_version) const;
     int get_voted_fork_index(uint64_t height) const;
-    uint8_t get_effective_version(uint8_t version) const;
+    uint8_t get_effective_version(uint8_t voting_version) const;
-    bool add(uint8_t block_version, uint64_t height);
+    bool add(uint8_t block_version, uint8_t voting_version, uint64_t height);
 
     bool rescan_from_block_height(uint64_t height);
     bool rescan_from_chain_height(uint64_t height);

src/cryptonote_protocol/cryptonote_protocol_handler.inl

@@ -571,6 +571,7 @@ namespace cryptonote
 				{
 				  LOG_PRINT_CCONTEXT_L1("Block verification failed, dropping connection");
 				  m_p2p->drop_connection(context);
+				  m_p2p->add_ip_fail(context.m_remote_ip);
 				  m_core.cleanup_handle_incoming_blocks();
 				  return 1;
 				}
@@ -578,6 +579,7 @@ namespace cryptonote
 				{
 				  LOG_PRINT_CCONTEXT_L1("Block received at sync phase was marked as orphaned, dropping connection");
 				  m_p2p->drop_connection(context);
+				  m_p2p->add_ip_fail(context.m_remote_ip);
 				  m_core.cleanup_handle_incoming_blocks();				  
 				  return 1;
 				}
@@ -728,6 +730,7 @@ namespace cryptonote
     {
       LOG_ERROR_CCONTEXT("sent empty m_block_ids, dropping connection");
       m_p2p->drop_connection(context);
+      m_p2p->add_ip_fail(context.m_remote_ip);
       return 1;
     }
 
@@ -736,6 +739,7 @@ namespace cryptonote
       LOG_ERROR_CCONTEXT("sent m_block_ids starting from unknown id: "
                                               << epee::string_tools::pod_to_hex(arg.m_block_ids.front()) << " , dropping connection");
       m_p2p->drop_connection(context);
+      m_p2p->add_ip_fail(context.m_remote_ip);
       return 1;
     }
     

src/p2p/net_node.h

@@ -42,6 +42,7 @@
 #include <boost/program_options/variables_map.hpp>
 #include <boost/serialization/version.hpp>
 #include <boost/uuid/uuid.hpp>
+#include <boost/serialization/map.hpp>
 
 #include "cryptonote_config.h"
 #include "warnings.h"
@@ -66,7 +67,8 @@ namespace nodetool
 
   template<class t_payload_net_handler>
   class node_server: public epee::levin::levin_commands_handler<p2p_connection_context_t<typename t_payload_net_handler::connection_context> >,
-                     public i_p2p_endpoint<typename t_payload_net_handler::connection_context>
+                     public i_p2p_endpoint<typename t_payload_net_handler::connection_context>,
+                     public epee::net_utils::i_connection_filter
   {
     struct by_conn_id{};
     struct by_peer_id{};
@@ -169,6 +171,10 @@ namespace nodetool
     virtual bool drop_connection(const epee::net_utils::connection_context_base& context);
     virtual void request_callback(const epee::net_utils::connection_context_base& context);
     virtual void for_each_connection(std::function<bool(typename t_payload_net_handler::connection_context&, peerid_type)> f);
+    virtual bool block_ip(uint32_t adress);
+    virtual bool add_ip_fail(uint32_t address);
+    //----------------- i_connection_filter  --------------------------------------------------------
+    virtual bool is_remote_ip_allowed(uint32_t adress);
     //-----------------------------------------------------------------------------------------------
     bool parse_peer_from_string(nodetool::net_address& pe, const std::string& node_addr);
     bool handle_command_line(
@@ -196,6 +202,8 @@ namespace nodetool
     template<class t_callback>
     bool try_ping(basic_node_data& node_data, p2p_connection_context& context, t_callback cb);
     bool make_expected_connections_count(bool white_list, size_t expected_connections);
+    void cache_connect_fail_info(const net_address& addr);
+    bool is_addr_recently_failed(const net_address& addr);
     bool is_priority_node(const net_address& na);
 
     template <class Container>
@@ -282,6 +290,15 @@ namespace nodetool
     //keep connections to initiate some interactions
     net_server m_net_server;
     boost::uuids::uuid m_network_id;
+
+    std::map<net_address, time_t> m_conn_fails_cache;
+    epee::critical_section m_conn_fails_cache_lock;
+
+    epee::critical_section m_blocked_ips_lock;
+    std::map<uint32_t, time_t> m_blocked_ips;
+
+    epee::critical_section m_ip_fails_score_lock;
+    std::map<uint32_t, uint64_t> m_ip_fails_score;
   };
 }
 

src/p2p/net_node.inl

@@ -28,6 +28,8 @@
 // 
 // Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
 
+// IP blocking adapted from Boolberry
+
 #pragma once
 
 #include <algorithm>
@@ -161,6 +163,22 @@ namespace nodetool
   }
   //-----------------------------------------------------------------------------------
   template<class t_payload_net_handler>
+  bool node_server<t_payload_net_handler>::is_remote_ip_allowed(uint32_t addr)
+  {
+    CRITICAL_REGION_LOCAL(m_blocked_ips_lock);
+    auto it = m_blocked_ips.find(addr);
+    if(it == m_blocked_ips.end())
+      return true;
+    if(time(nullptr) - it->second > P2P_IP_BLOCKTIME )
+    {
+      m_blocked_ips.erase(it);
+      LOG_PRINT_CYAN("IP " << epee::string_tools::get_ip_string_from_int32(addr) << "is unblocked.", LOG_LEVEL_0);
+      return true;
+    }
+    return false;
+  }
+  //-----------------------------------------------------------------------------------
+  template<class t_payload_net_handler>
   bool node_server<t_payload_net_handler>::make_default_config()
   {
     m_config.m_peer_id  = crypto::rand<uint64_t>();
@@ -168,6 +186,31 @@ namespace nodetool
   }
   //-----------------------------------------------------------------------------------
   template<class t_payload_net_handler>
+  bool node_server<t_payload_net_handler>::block_ip(uint32_t addr)
+  {
+    CRITICAL_REGION_LOCAL(m_blocked_ips_lock);
+    m_blocked_ips[addr] = time(nullptr);
+    LOG_PRINT_CYAN("IP " << epee::string_tools::get_ip_string_from_int32(addr) << " blocked.", LOG_LEVEL_0);
+    return true;
+  }
+  //-----------------------------------------------------------------------------------
+  template<class t_payload_net_handler>
+  bool node_server<t_payload_net_handler>::add_ip_fail(uint32_t address)
+  {
+    CRITICAL_REGION_LOCAL(m_ip_fails_score_lock);
+    uint64_t fails = ++m_ip_fails_score[address];
+    LOG_PRINT_CYAN("IP " << epee::string_tools::get_ip_string_from_int32(address) << " fail score=" << fails, LOG_LEVEL_1);
+    if(fails > P2P_IP_FAILS_BEFORE_BLOCK)
+    {
+      auto it = m_ip_fails_score.find(address);
+      CHECK_AND_ASSERT_MES(it != m_ip_fails_score.end(), false, "internal error");
+      it->second = P2P_IP_FAILS_BEFORE_BLOCK/2;
+      block_ip(address);
+    }
+    return true;
+  }
+  //-----------------------------------------------------------------------------------
+  template<class t_payload_net_handler>
   bool node_server<t_payload_net_handler>::parse_peer_from_string(nodetool::net_address& pe, const std::string& node_addr)
   {
     return epee::string_tools::parse_peer_from_string(pe.ip, pe.port, node_addr);
@@ -428,6 +471,7 @@ namespace nodetool
     m_net_server.set_threads_prefix("P2P");
     m_net_server.get_config_object().m_pcommands_handler = this;
     m_net_server.get_config_object().m_invoke_timeout = P2P_DEFAULT_INVOKE_TIMEOUT;
+    m_net_server.set_connection_filter(this);
 
     //try to bind
     LOG_PRINT_L0("Binding on " << m_bind_ip << ":" << m_port);
@@ -624,6 +668,7 @@ namespace nodetool
       if(!handle_remote_peerlist(rsp.local_peerlist, rsp.node_data.local_time, context))
       {
         LOG_ERROR_CCONTEXT("COMMAND_HANDSHAKE: failed to handle_remote_peerlist(...), closing connection.");
+        add_ip_fail(context.m_remote_ip);
         return;
       }
       hsh_result = true;
@@ -685,6 +730,7 @@ namespace nodetool
       {
         LOG_ERROR_CCONTEXT("COMMAND_TIMED_SYNC: failed to handle_remote_peerlist(...), closing connection.");
         m_net_server.get_config_object().close(context.m_connection_id );
+        add_ip_fail(context.m_remote_ip);
       }
       if(!context.m_is_income)
         m_peerlist.set_peer_just_seen(context.peer_id, context.m_remote_ip, context.m_remote_port);
@@ -829,6 +875,20 @@ namespace nodetool
 
 #undef LOG_PRINT_CC_PRIORITY_NODE
 
+  //-----------------------------------------------------------------------------------
+  template<class t_payload_net_handler>
+  bool node_server<t_payload_net_handler>::is_addr_recently_failed(const net_address& addr)
+  {
+    CRITICAL_REGION_LOCAL(m_conn_fails_cache_lock);
+    auto it = m_conn_fails_cache.find(addr);
+    if(it == m_conn_fails_cache.end())
+      return false;
+
+    if(time(NULL) - it->second > P2P_FAILED_ADDR_FORGET_SECONDS)
+      return false;
+    else
+      return true;
+  }
   //-----------------------------------------------------------------------------------
   template<class t_payload_net_handler>
   bool node_server<t_payload_net_handler>::make_new_connection_from_peerlist(bool use_white_list)
@@ -866,7 +926,13 @@ namespace nodetool
         continue;
 			}
 
-      LOG_PRINT_L1("Selected peer: " << pe.id << " " << epee::string_tools::get_ip_string_from_int32(pe.adr.ip)
+      if(!is_remote_ip_allowed(pe.adr.ip))
+        continue;
+
+      if(is_addr_recently_failed(pe.adr))
+        continue;
+
+      LOG_PRINT_L2("Selected peer: " << pe.id << " " << epee::string_tools::get_ip_string_from_int32(pe.adr.ip)
                     << ":" << boost::lexical_cast<std::string>(pe.adr.port)
                     << "[white=" << use_white_list
                     << "] last_seen: " << (pe.last_seen ? epee::misc_utils::get_time_interval_string(time(NULL) - pe.last_seen) : "never"));
@@ -1270,6 +1336,7 @@ namespace nodetool
 
       LOG_PRINT_CCONTEXT_L1("WRONG NETWORK AGENT CONNECTED! id=" << epee::string_tools::get_str_from_guid_a(arg.node_data.network_id));
       drop_connection(context);
+      add_ip_fail(context.m_remote_ip);
       return 1;
     }
 
@@ -1277,6 +1344,7 @@ namespace nodetool
     {
       LOG_ERROR_CCONTEXT("COMMAND_HANDSHAKE came not from incoming connection");
       drop_connection(context);
+      add_ip_fail(context.m_remote_ip);
       return 1;
     }
 

src/p2p/net_node_common.h

@@ -50,6 +50,8 @@ namespace nodetool
     virtual void request_callback(const epee::net_utils::connection_context_base& context)=0;
     virtual uint64_t get_connections_count()=0;
     virtual void for_each_connection(std::function<bool(t_connection_context&, peerid_type)> f)=0;
+    virtual bool block_ip(uint32_t adress)=0;
+    virtual bool add_ip_fail(uint32_t adress)=0;
   };
 
   template<class t_connection_context>
@@ -84,5 +86,13 @@ namespace nodetool
     {
       return false;
     }
+    virtual bool block_ip(uint32_t adress)
+    {
+      return true;
+    }
+    virtual bool add_ip_fail(uint32_t adress)
+    {
+      return true;
+    }
   };
 }

src/p2p/net_peerlist.h

@@ -53,6 +53,7 @@
 #include "net_peerlist_boost_serialization.h"
 
 
+#define CURRENT_PEERLIST_STORAGE_ARCHIVE_VER    4
 
 namespace nodetool
 {
@@ -394,4 +395,4 @@ namespace nodetool
   //--------------------------------------------------------------------------------------------------
 }
 
-BOOST_CLASS_VERSION(nodetool::peerlist_manager, 4)
+BOOST_CLASS_VERSION(nodetool::peerlist_manager, CURRENT_PEERLIST_STORAGE_ARCHIVE_VER)

tests/unit_tests/hardfork.cpp

@@ -135,6 +135,7 @@ private:
 static cryptonote::block mkblock(uint8_t version)
 {
   cryptonote::block b;
+  b.major_version = version;
   b.minor_version = version;
   return b;
 }
@@ -144,7 +145,7 @@ TEST(empty_hardforks, Success)
   TestDB db;
   HardFork hf(db);
 
-  ASSERT_TRUE(hf.add(1, 0, 0));
+  ASSERT_TRUE(hf.add_fork(1, 0, 0));
   hf.init();
   ASSERT_TRUE(hf.get_state(time(NULL)) == HardFork::Ready);
   ASSERT_TRUE(hf.get_state(time(NULL) + 3600*24*400) == HardFork::Ready);
@@ -163,13 +164,13 @@ TEST(ordering, Success)
   TestDB db;
   HardFork hf(db);
 
-  ASSERT_TRUE(hf.add(2, 2, 1));
+  ASSERT_TRUE(hf.add_fork(2, 2, 1));
-  ASSERT_FALSE(hf.add(3, 3, 1));
+  ASSERT_FALSE(hf.add_fork(3, 3, 1));
-  ASSERT_FALSE(hf.add(3, 2, 2));
+  ASSERT_FALSE(hf.add_fork(3, 2, 2));
-  ASSERT_FALSE(hf.add(2, 3, 2));
+  ASSERT_FALSE(hf.add_fork(2, 3, 2));
-  ASSERT_TRUE(hf.add(3, 10, 2));
+  ASSERT_TRUE(hf.add_fork(3, 10, 2));
-  ASSERT_TRUE(hf.add(4, 20, 3));
+  ASSERT_TRUE(hf.add_fork(4, 20, 3));
-  ASSERT_FALSE(hf.add(5, 5, 4));
+  ASSERT_FALSE(hf.add_fork(5, 5, 4));
 }
 
 TEST(states, Success)
@@ -177,8 +178,8 @@ TEST(states, Success)
   TestDB db;
   HardFork hf(db);
 
-  ASSERT_TRUE(hf.add(1, 0, 0));
+  ASSERT_TRUE(hf.add_fork(1, 0, 0));
-  ASSERT_TRUE(hf.add(2, BLOCKS_PER_YEAR, SECONDS_PER_YEAR));
+  ASSERT_TRUE(hf.add_fork(2, BLOCKS_PER_YEAR, SECONDS_PER_YEAR));
 
   ASSERT_TRUE(hf.get_state(0) == HardFork::Ready);
   ASSERT_TRUE(hf.get_state(SECONDS_PER_YEAR / 2) == HardFork::Ready);
@@ -186,7 +187,7 @@ TEST(states, Success)
   ASSERT_TRUE(hf.get_state(SECONDS_PER_YEAR + (HardFork::DEFAULT_UPDATE_TIME + HardFork::DEFAULT_FORKED_TIME) / 2) == HardFork::UpdateNeeded);
   ASSERT_TRUE(hf.get_state(SECONDS_PER_YEAR + HardFork::DEFAULT_FORKED_TIME * 2) == HardFork::LikelyForked);
 
-  ASSERT_TRUE(hf.add(3, BLOCKS_PER_YEAR * 5, SECONDS_PER_YEAR * 5));
+  ASSERT_TRUE(hf.add_fork(3, BLOCKS_PER_YEAR * 5, SECONDS_PER_YEAR * 5));
 
   ASSERT_TRUE(hf.get_state(0) == HardFork::Ready);
   ASSERT_TRUE(hf.get_state(SECONDS_PER_YEAR / 2) == HardFork::Ready);
@@ -201,10 +202,10 @@ TEST(steps_asap, Success)
   HardFork hf(db, 1,0,1,1,1);
 
   //                 v  h  t
-  ASSERT_TRUE(hf.add(1, 0, 0));
+  ASSERT_TRUE(hf.add_fork(1, 0, 0));
-  ASSERT_TRUE(hf.add(4, 2, 1));
+  ASSERT_TRUE(hf.add_fork(4, 2, 1));
-  ASSERT_TRUE(hf.add(7, 4, 2));
+  ASSERT_TRUE(hf.add_fork(7, 4, 2));
-  ASSERT_TRUE(hf.add(9, 6, 3));
+  ASSERT_TRUE(hf.add_fork(9, 6, 3));
   hf.init();
 
   for (uint64_t h = 0; h < 10; ++h) {
@@ -229,9 +230,9 @@ TEST(steps_1, Success)
   TestDB db;
   HardFork hf(db, 1,0,1,1,1);
 
-  ASSERT_TRUE(hf.add(1, 0, 0));
+  ASSERT_TRUE(hf.add_fork(1, 0, 0));
   for (int n = 1 ; n < 10; ++n)
-    ASSERT_TRUE(hf.add(n+1, n, n));
+    ASSERT_TRUE(hf.add_fork(n+1, n, n));
   hf.init();
 
   for (uint64_t h = 0 ; h < 10; ++h) {
@@ -251,10 +252,10 @@ TEST(reorganize, Same)
     HardFork hf(db, 1, 0, 1, 1, history, 100);
 
     //                 v  h  t
-    ASSERT_TRUE(hf.add(1, 0, 0));
+    ASSERT_TRUE(hf.add_fork(1, 0, 0));
-    ASSERT_TRUE(hf.add(4, 2, 1));
+    ASSERT_TRUE(hf.add_fork(4, 2, 1));
-    ASSERT_TRUE(hf.add(7, 4, 2));
+    ASSERT_TRUE(hf.add_fork(7, 4, 2));
-    ASSERT_TRUE(hf.add(9, 6, 3));
+    ASSERT_TRUE(hf.add_fork(9, 6, 3));
     hf.init();
 
     //                                 index  0  1  2  3  4  5  6  7  8  9
@@ -270,6 +271,10 @@ TEST(reorganize, Same)
         uint8_t version = hh >= history ? block_versions[hh - history] : 1;
         ASSERT_EQ(hf.get(hh), version);
       }
+      ASSERT_EQ(hf.get_start_height(1), 0);
+      ASSERT_EQ(hf.get_start_height(4), 2 + history);
+      ASSERT_EQ(hf.get_start_height(7), 4 + history);
+      ASSERT_EQ(hf.get_start_height(9), 6 + history);
     }
   }
 }
@@ -281,10 +286,10 @@ TEST(reorganize, Changed)
   HardFork hf(db, 1, 0, 1, 1, 4, 100);
 
   //                 v  h  t
-  ASSERT_TRUE(hf.add(1, 0, 0));
+  ASSERT_TRUE(hf.add_fork(1, 0, 0));
-  ASSERT_TRUE(hf.add(4, 2, 1));
+  ASSERT_TRUE(hf.add_fork(4, 2, 1));
-  ASSERT_TRUE(hf.add(7, 4, 2));
+  ASSERT_TRUE(hf.add_fork(7, 4, 2));
-  ASSERT_TRUE(hf.add(9, 6, 3));
+  ASSERT_TRUE(hf.add_fork(9, 6, 3));
   hf.init();
 
   //                                    fork         4     7     9
@@ -301,6 +306,10 @@ TEST(reorganize, Changed)
     for (int hh = 0; hh < 16; ++hh) {
       ASSERT_EQ(hf.get(hh), expected_versions[hh]);
     }
+    ASSERT_EQ(hf.get_start_height(1), 0);
+    ASSERT_EQ(hf.get_start_height(4), 6);
+    ASSERT_EQ(hf.get_start_height(7), 8);
+    ASSERT_EQ(hf.get_start_height(9), 10);
   }
 
   // delay a bit for 9, and go back to 1 to check it stays at 9
@@ -321,6 +330,10 @@ TEST(reorganize, Changed)
   for (int hh = 0; hh < 15; ++hh) {
     ASSERT_EQ(hf.get(hh), expected_versions_new[hh]);
   }
+  ASSERT_EQ(hf.get_start_height(1), 0);
+  ASSERT_EQ(hf.get_start_height(4), 6);
+  ASSERT_EQ(hf.get_start_height(7), 11);
+  ASSERT_EQ(hf.get_start_height(9), 14);
 }
 
 TEST(voting, threshold)
@@ -330,8 +343,8 @@ TEST(voting, threshold)
     HardFork hf(db, 1, 0, 1, 1, 8, threshold);
 
     //                 v  h  t
-    ASSERT_TRUE(hf.add(1, 0, 0));
+    ASSERT_TRUE(hf.add_fork(1, 0, 0));
-    ASSERT_TRUE(hf.add(2, 2, 1));
+    ASSERT_TRUE(hf.add_fork(2, 2, 1));
     hf.init();
 
     for (uint64_t h = 0; h <= 8; ++h) {
@@ -359,10 +372,10 @@ TEST(voting, different_thresholds)
     HardFork hf(db, 1, 0, 1, 1, 4, 50); // window size 4
 
     //                 v  h  t
-    ASSERT_TRUE(hf.add(1, 0, 0));
+    ASSERT_TRUE(hf.add_fork(1, 0, 0));
-    ASSERT_TRUE(hf.add(2, 5, 0, 1)); // asap
+    ASSERT_TRUE(hf.add_fork(2, 5, 0, 1)); // asap
-    ASSERT_TRUE(hf.add(3, 10, 100, 2)); // all votes
+    ASSERT_TRUE(hf.add_fork(3, 10, 100, 2)); // all votes
-    ASSERT_TRUE(hf.add(4, 15, 3)); // default 50% votes
+    ASSERT_TRUE(hf.add_fork(4, 15, 3)); // default 50% votes
     hf.init();
 
     //                                           0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5  6  7  8  9
@@ -386,8 +399,8 @@ TEST(new_blocks, denied)
     HardFork hf(db, 1, 0, 1, 1, 4, 50);
 
     //                 v  h  t
-    ASSERT_TRUE(hf.add(1, 0, 0));
+    ASSERT_TRUE(hf.add_fork(1, 0, 0));
-    ASSERT_TRUE(hf.add(2, 2, 1));
+    ASSERT_TRUE(hf.add_fork(2, 2, 1));
     hf.init();
 
     ASSERT_TRUE(hf.add(mkblock(1), 0));
@@ -411,8 +424,8 @@ TEST(new_version, early)
     HardFork hf(db, 1, 0, 1, 1, 4, 50);
 
     //                 v  h  t
-    ASSERT_TRUE(hf.add(1, 0, 0));
+    ASSERT_TRUE(hf.add_fork(1, 0, 0));
-    ASSERT_TRUE(hf.add(2, 4, 1));
+    ASSERT_TRUE(hf.add_fork(2, 4, 1));
     hf.init();
 
     ASSERT_TRUE(hf.add(mkblock(2), 0));
@@ -433,9 +446,9 @@ TEST(reorganize, changed)
     HardFork hf(db, 1, 0, 1, 1, 4, 50);
 
     //                 v  h  t
-    ASSERT_TRUE(hf.add(1, 0, 0));
+    ASSERT_TRUE(hf.add_fork(1, 0, 0));
-    ASSERT_TRUE(hf.add(2, 2, 1));
+    ASSERT_TRUE(hf.add_fork(2, 2, 1));
-    ASSERT_TRUE(hf.add(3, 5, 2));
+    ASSERT_TRUE(hf.add_fork(3, 5, 2));
     hf.init();
 
 #define ADD(v, h, a) \
@@ -487,9 +500,9 @@ TEST(get, higher)
     HardFork hf(db, 1, 0, 1, 1, 4, 50);
 
     //                 v  h  t
-    ASSERT_TRUE(hf.add(1, 0, 0));
+    ASSERT_TRUE(hf.add_fork(1, 0, 0));
-    ASSERT_TRUE(hf.add(2, 2, 1));
+    ASSERT_TRUE(hf.add_fork(2, 2, 1));
-    ASSERT_TRUE(hf.add(3, 5, 2));
+    ASSERT_TRUE(hf.add_fork(3, 5, 2));
     hf.init();
 
     ASSERT_EQ(hf.get_ideal_version(0), 1);