Merge pull request #410

33affd2 blockchain: on hardfork 2, require mixin 2 at least if possible (moneromooo-monero)
434e0f4 hardfork: make the voting window a week (moneromooo-monero)
0a7421b hardfork: rescan speedup (moneromooo-monero)
fec98b8 hardfork: remove use of GNU extension for initializing object (moneromooo-monero)
4bbf944 blockchain: on hardfork 2, allow miners to claim less money than allowed (moneromooo-monero)
088bc56 hardfork: change window semantics to not count the newly added block (moneromooo-monero)
198f557 blockchain: use different hard fork settings for testnet and mainnet (moneromooo-monero)

4 files changed, 151 insertions, 49 deletions

diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 65d07dcf7..3d96f6f5d 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -73,13 +73,24 @@ static const struct {
   uint8_t version;
   uint64_t height;
   time_t time;
-} hard_forks[] = {
+} mainnet_hard_forks[] = {
   // version 1 from the start of the blockchain
   { 1, 1, 1341378000 },
 
   // version 2 can start from block 1009827, setup on the 20th of september
   { 2, 1009827, 1442763710 },
 };
+static const uint64_t mainnet_hard_fork_version_1_till = 750000;
+
+static const struct {
+  uint8_t version;
+  uint64_t height;
+  time_t time;
+} testnet_hard_forks[] = {
+  // version 1 from the start of the blockchain
+  { 1, 1, 1341378000 },
+};
+static const uint64_t testnet_hard_fork_version_1_till = 540000;
 
 //------------------------------------------------------------------
 Blockchain::Blockchain(tx_memory_pool& tx_pool) :
@@ -287,9 +298,17 @@ bool Blockchain::init(BlockchainDB* db, const bool testnet)
 
     m_db = db;
 
-    m_hardfork = new HardFork(*db);
-    for (size_t n = 0; n < sizeof(hard_forks) / sizeof(hard_forks[0]); ++n)
-      m_hardfork->add(hard_forks[n].version, hard_forks[n].height, hard_forks[n].time);
+    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].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].time);
+    }
     m_hardfork->init();
 
     // if the blockchain is new, add the genesis block
@@ -947,10 +966,14 @@ bool Blockchain::validate_miner_transaction(const block& b, size_t cumulative_bl
         LOG_PRINT_L1("coinbase transaction spend too much money (" << print_money(money_in_use) << "). Block reward is " << print_money(base_reward + fee) << "(" << print_money(base_reward) << "+" << print_money(fee) << ")");
         return false;
     }
-    if(base_reward + fee != money_in_use)
+    // From hard fork 2, we allow a miner to claim less block reward than is allowed, in case a miner wants less dust
+    if (m_hardfork->get_current_version() < 2)
     {
-        LOG_PRINT_L1("coinbase transaction doesn't use full amount of block reward:  spent: " << money_in_use << ",  block reward " << base_reward + fee << "(" << base_reward << "+" << fee << ")");
-        return false;
+        if(base_reward + fee != money_in_use)
+        {
+            LOG_PRINT_L1("coinbase transaction doesn't use full amount of block reward:  spent: " << money_in_use << ",  block reward " << base_reward + fee << "(" << base_reward << "+" << fee << ")");
+            return false;
+        }
     }
     return true;
 }
@@ -1975,6 +1998,43 @@ bool Blockchain::check_tx_inputs(const transaction& tx, uint64_t* pmax_used_bloc
         return true;
     }
 
+    // from hard fork 2, we require mixin at least 2 unless one output cannot mix with 2 others
+    // if one output cannot mix with 2 others, we accept at most 1 output that can mix
+    if (m_hardfork->get_current_version() >= 2)
+    {
+        size_t n_unmixable = 0, n_mixable = 0;
+        size_t mixin = std::numeric_limits<size_t>::max();
+        for (const auto& txin : tx.vin)
+        {
+            // non txin_to_key inputs will be rejected below
+            if (txin.type() == typeid(txin_to_key))
+            {
+              const txin_to_key& in_to_key = boost::get<txin_to_key>(txin);
+              uint64_t n_outputs = m_db->get_num_outputs(in_to_key.amount);
+              // n_outputs includes the output we're considering
+              if (n_outputs <= 2)
+                ++n_unmixable;
+              else
+                ++n_mixable;
+              if (in_to_key.key_offsets.size() - 1 < mixin)
+                mixin = in_to_key.key_offsets.size() - 1;
+            }
+        }
+        if (mixin < 2)
+        {
+          if (n_unmixable == 0)
+          {
+            LOG_PRINT_L1("Tx " << get_transaction_hash(tx) << " has too low mixin (" << mixin << "), and no unmixable inputs");
+            return false;
+          }
+          if (n_mixable > 1)
+          {
+            LOG_PRINT_L1("Tx " << get_transaction_hash(tx) << " has too low mixin (" << mixin << "), and more than one mixable input with unmixable inputs");
+            return false;
+          }
+        }
+    }
+
 	auto it = m_check_txin_table.find(tx_prefix_hash);
 	if(it == m_check_txin_table.end())
 	{
diff --git a/src/cryptonote_core/hardfork.cpp b/src/cryptonote_core/hardfork.cpp
index d2e95b58e..4b40a4cf3 100644
--- a/src/cryptonote_core/hardfork.cpp
+++ b/src/cryptonote_core/hardfork.cpp
@@ -35,14 +35,19 @@
 
 using namespace cryptonote;
 
-HardFork::HardFork(cryptonote::BlockchainDB &db, uint8_t original_version, time_t forked_time, time_t update_time, uint64_t window_size, int threshold_percent):
+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, int threshold_percent):
   db(db),
   original_version(original_version),
+  original_version_till_height(original_version_till_height),
   forked_time(forked_time),
   update_time(update_time),
   window_size(window_size),
   threshold_percent(threshold_percent)
 {
+  if (window_size == 0)
+    throw "window_size needs to be strictly positive";
+  if (threshold_percent > 100)
+    throw "threshold_percent needs to be between 0 and 100";
 }
 
 bool HardFork::add(uint8_t version, uint64_t height, time_t time)
@@ -60,13 +65,12 @@ bool HardFork::add(uint8_t version, uint64_t height, time_t time)
     if (time <= heights.back().time)
       return false;
   }
-  heights.push_back({version: version, height: height, time: time});
+  heights.push_back(Params(version, height, time));
   return true;
 }
 
-uint8_t HardFork::get_effective_version(const cryptonote::block &block) const
+uint8_t HardFork::get_effective_version(uint8_t version) const
 {
-  uint8_t version = block.major_version;
   if (!heights.empty()) {
     uint8_t max_version = heights.back().version;
     if (version > max_version)
@@ -75,25 +79,27 @@ uint8_t HardFork::get_effective_version(const cryptonote::block &block) const
   return version;
 }
 
-bool HardFork::do_check(const cryptonote::block &block) const
+bool HardFork::do_check(uint8_t version) const
 {
-  return block.major_version >= heights[current_fork_index].version;
+  return version >= heights[current_fork_index].version;
 }
 
 bool HardFork::check(const cryptonote::block &block) const
 {
   CRITICAL_REGION_LOCAL(lock);
-  return do_check(block);
+  return do_check(block.major_version);
 }
 
-bool HardFork::add(const cryptonote::block &block, uint64_t height)
+bool HardFork::add(uint8_t block_version, uint64_t height)
 {
   CRITICAL_REGION_LOCAL(lock);
 
-  if (!do_check(block))
+  if (!do_check(block_version))
     return false;
 
-  const uint8_t version = get_effective_version(block);
+  db.set_hard_fork_version(height, heights[current_fork_index].version);
+
+  const uint8_t version = get_effective_version(block_version);
 
   while (versions.size() >= window_size) {
     const uint8_t old_version = versions.front();
@@ -105,19 +111,23 @@ bool HardFork::add(const cryptonote::block &block, uint64_t height)
   last_versions[version]++;
   versions.push_back(version);
 
-  uint8_t voted = get_voted_fork_index(height);
+  uint8_t voted = get_voted_fork_index(height + 1);
   if (voted > current_fork_index) {
     for (int v = heights[current_fork_index].version + 1; v <= heights[voted].version; ++v) {
-      db.set_hard_fork_starting_height(v, height);
+      // we reached the vote threshold with this block, next one will be forked
+      db.set_hard_fork_starting_height(v, height + 1);
     }
     current_fork_index = voted;
   }
 
-  db.set_hard_fork_version(height, heights[current_fork_index].version);
-
   return true;
 }
 
+bool HardFork::add(const cryptonote::block &block, uint64_t height)
+{
+  return add(block.major_version, height);
+}
+
 void HardFork::init()
 {
   CRITICAL_REGION_LOCAL(lock);
@@ -149,17 +159,29 @@ void HardFork::init()
   LOG_PRINT_L1("reorganization done");
 }
 
+uint8_t HardFork::get_block_version(uint64_t height) const
+{
+  if (height <= original_version_till_height)
+    return original_version;
+
+  const cryptonote::block &block = db.get_block_from_height(height);
+  return block.major_version;
+}
+
 bool HardFork::reorganize_from_block_height(uint64_t height)
 {
   CRITICAL_REGION_LOCAL(lock);
   if (height >= db.height())
     return false;
 
+  //db.set_batch_transactions(true);
+  //db.batch_start();
+
   versions.clear();
 
   for (size_t n = 0; n < 256; ++n)
     last_versions[n] = 0;
-  const uint64_t rescan_height = height >= (window_size - 1) ? height - (window_size - 1) : 0;
+  const uint64_t rescan_height = height >= (window_size - 1) ? height - (window_size  -1) : 0;
   const uint8_t start_version = height == 0 ? original_version : db.get_hard_fork_version(height);
   while (heights[current_fork_index].version > start_version) {
     db.set_hard_fork_starting_height(heights[current_fork_index].version, std::numeric_limits<uint64_t>::max());
@@ -167,15 +189,27 @@ bool HardFork::reorganize_from_block_height(uint64_t height)
   }
   for (uint64_t h = rescan_height; h <= height; ++h) {
     cryptonote::block b = db.get_block_from_height(h);
-    const uint8_t v = get_effective_version(b);
+    const uint8_t v = get_effective_version(b.major_version);
     last_versions[v]++;
     versions.push_back(v);
   }
+
+  uint8_t voted = get_voted_fork_index(height + 1);
+  if (voted > current_fork_index) {
+    for (int v = heights[current_fork_index].version + 1; v <= heights[voted].version; ++v) {
+      // we reached the vote threshold with this block, next one will be forked
+      db.set_hard_fork_starting_height(v, height + 1);
+    }
+    current_fork_index = voted;
+  }
+
   const uint64_t bc_height = db.height();
   for (uint64_t h = height + 1; h < bc_height; ++h) {
-    add(db.get_block_from_height(h), h);
+    add(get_block_version(h), h);
   }
 
+  //db.batch_stop();
+
   return true;
 }
 
@@ -224,7 +258,7 @@ HardFork::State HardFork::get_state() const
 uint8_t HardFork::get(uint64_t height) const
 {
   CRITICAL_REGION_LOCAL(lock);
-  if (height > db.height()) {
+  if (height >= db.height()) {
     assert(false);
     return 255;
   }
diff --git a/src/cryptonote_core/hardfork.h b/src/cryptonote_core/hardfork.h
index bdac87f2c..6b98b9fa1 100644
--- a/src/cryptonote_core/hardfork.h
+++ b/src/cryptonote_core/hardfork.h
@@ -44,9 +44,10 @@ namespace cryptonote
       Ready,
     } State;
 
+    static const uint64_t DEFAULT_ORIGINAL_VERSION_TILL_HEIGHT = 0; // <= actual height
     static const time_t DEFAULT_FORKED_TIME = 31557600; // a year in seconds
     static const time_t DEFAULT_UPDATE_TIME = 31557600 / 2;
-    static const uint64_t DEFAULT_WINDOW_SIZE = 50; // supermajority window check length
+    static const uint64_t DEFAULT_WINDOW_SIZE = 10080; // supermajority window check length - a week
     static const int DEFAULT_THRESHOLD_PERCENT = 80;
 
     /**
@@ -58,7 +59,7 @@ namespace cryptonote
      * @param window_size the size of the window in blocks to consider for version voting
      * @param threshold_percent the size of the majority in percents
      */
-    HardFork(cryptonote::BlockchainDB &db, uint8_t original_version = 1, time_t forked_time = DEFAULT_FORKED_TIME, time_t update_time = DEFAULT_UPDATE_TIME, uint64_t window_size = DEFAULT_WINDOW_SIZE, int threshold_percent = DEFAULT_THRESHOLD_PERCENT);
+    HardFork(cryptonote::BlockchainDB &db, uint8_t original_version = 1, uint64_t original_version_till_height = DEFAULT_ORIGINAL_VERSION_TILL_HEIGHT, time_t forked_time = DEFAULT_FORKED_TIME, time_t update_time = DEFAULT_UPDATE_TIME, uint64_t window_size = DEFAULT_WINDOW_SIZE, int threshold_percent = DEFAULT_THRESHOLD_PERCENT);
 
     /**
      * @brief add a new hardfork height
@@ -182,9 +183,11 @@ namespace cryptonote
 
   private:
 
-    bool do_check(const cryptonote::block &block) const;
+    uint8_t get_block_version(uint64_t height) const;
+    bool do_check(uint8_t version) const;
     int get_voted_fork_index(uint64_t height) const;
-    uint8_t get_effective_version(const cryptonote::block &block) const;
+    uint8_t get_effective_version(uint8_t version) const;
+    bool add(uint8_t block_version, uint64_t height);
 
   private:
 
@@ -196,12 +199,14 @@ namespace cryptonote
     int threshold_percent;
 
     uint8_t original_version;
+    uint64_t original_version_till_height;
 
-    typedef struct {
+    struct Params {
       uint8_t version;
       uint64_t height;
       time_t time;
-    } Params;
+      Params(uint8_t version, uint64_t height, time_t time): version(version), height(height), time(time) {}
+    };
     std::vector<Params> heights;
 
     std::deque<uint8_t> versions; /* rolling window of the last N blocks' versions */
diff --git a/tests/unit_tests/hardfork.cpp b/tests/unit_tests/hardfork.cpp
index ad00ed60f..25d03b703 100644
--- a/tests/unit_tests/hardfork.cpp
+++ b/tests/unit_tests/hardfork.cpp
@@ -196,7 +196,7 @@ TEST(states, Success)
 TEST(steps_asap, Success)
 {
   TestDB db;
-  HardFork hf(db, 1,1,1,1);
+  HardFork hf(db, 1,0,1,1,1);
 
   //                 v  h  t
   ASSERT_TRUE(hf.add(1, 0, 0));
@@ -225,7 +225,7 @@ TEST(steps_asap, Success)
 TEST(steps_1, Success)
 {
   TestDB db;
-  HardFork hf(db, 1,1,1,1);
+  HardFork hf(db, 1,0,1,1,1);
 
   ASSERT_TRUE(hf.add(1, 0, 0));
   for (int n = 1 ; n < 10; ++n)
@@ -238,7 +238,7 @@ TEST(steps_1, Success)
   }
 
   for (uint64_t h = 0; h < 10; ++h) {
-    ASSERT_EQ(hf.get(h), h+1);
+    ASSERT_EQ(hf.get(h), std::max(1,(int)h));
   }
 }
 
@@ -246,7 +246,7 @@ TEST(reorganize, Same)
 {
   for (int history = 1; history <= 12; ++history) {
     TestDB db;
-    HardFork hf(db, 1, 1, 1, history, 100);
+    HardFork hf(db, 1, 0, 1, 1, history, 100);
 
     //                 v  h  t
     ASSERT_TRUE(hf.add(1, 0, 0));
@@ -265,7 +265,7 @@ TEST(reorganize, Same)
     for (uint64_t rh = 0; rh < 20; ++rh) {
       hf.reorganize_from_block_height(rh);
       for (int hh = 0; hh < 20; ++hh) {
-        uint8_t version = hh >= (history-1) ? block_versions[hh - (history-1)] : 1;
+        uint8_t version = hh >= history ? block_versions[hh - history] : 1;
         ASSERT_EQ(hf.get(hh), version);
       }
     }
@@ -276,7 +276,7 @@ TEST(reorganize, Changed)
 {
   int history = 4;
   TestDB db;
-  HardFork hf(db, 1, 1, 1, 4, 100);
+  HardFork hf(db, 1, 0, 1, 1, 4, 100);
 
   //                 v  h  t
   ASSERT_TRUE(hf.add(1, 0, 0));
@@ -285,8 +285,10 @@ TEST(reorganize, Changed)
   ASSERT_TRUE(hf.add(9, 6, 3));
   hf.init();
 
+  //                                 fork         4     7     9
   //                                 index  0  1  2  3  4  5  6  7  8  9
   static const uint8_t block_versions[] = { 1, 1, 4, 4, 7, 7, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9 };
+  static const uint8_t expected_versions[] = { 1, 1, 1, 1, 1, 1, 4, 4, 7, 7, 9, 9, 9, 9, 9, 9 };
   for (uint64_t h = 0; h < 16; ++h) {
     db.add_block(mkblock(block_versions[h]), 0, 0, 0, crypto::hash());
     ASSERT_TRUE (hf.add(db.get_block_from_height(h), h));
@@ -295,14 +297,13 @@ TEST(reorganize, Changed)
   for (uint64_t rh = 0; rh < 16; ++rh) {
     hf.reorganize_from_block_height(rh);
     for (int hh = 0; hh < 16; ++hh) {
-      uint8_t version = hh >= (history-1) ? block_versions[hh - (history-1)] : 1;
-      ASSERT_EQ(hf.get(hh), version);
+      ASSERT_EQ(hf.get(hh), expected_versions[hh]);
     }
   }
 
   // delay a bit for 9, and go back to 1 to check it stays at 9
   static const uint8_t block_versions_new[] =    { 1, 1, 4, 4, 7, 7, 4, 7, 7, 7, 9, 9, 9, 9, 9, 1 };
-  static const uint8_t expected_versions_new[] = { 1, 1, 1, 1, 1, 4, 4, 4, 4, 4, 7, 7, 7, 9, 9, 9 };
+  static const uint8_t expected_versions_new[] = { 1, 1, 1, 1, 1, 1, 4, 4, 4, 4, 4, 7, 7, 7, 9, 9 };
   for (uint64_t h = 3; h < 16; ++h) {
     db.remove_block();
   }
@@ -324,7 +325,7 @@ TEST(voting, threshold)
 {
   for (int threshold = 87; threshold <= 88; ++threshold) {
     TestDB db;
-    HardFork hf(db, 1, 1, 1, 8, threshold);
+    HardFork hf(db, 1, 0, 1, 1, 8, threshold);
 
     //                 v  h  t
     ASSERT_TRUE(hf.add(1, 0, 0));
@@ -336,11 +337,13 @@ TEST(voting, threshold)
       db.add_block(mkblock(v), 0, 0, 0, crypto::hash());
       bool ret = hf.add(db.get_block_from_height(h), h);
       if (h >= 8 && threshold == 87) {
+        // for threshold 87, we reach the treshold at height 7, so from height 8, hard fork to version 2, but 8 tries to add 1
         ASSERT_FALSE(ret);
       }
       else {
+        // for threshold 88, we never reach the threshold
         ASSERT_TRUE(ret);
-        uint8_t expected = threshold == 88 ? 1 : h < 7 ? 1 : 2;
+        uint8_t expected = threshold == 88 ? 1 : h < 8 ? 1 : 2;
         ASSERT_EQ(hf.get(h), expected);
       }
     }
@@ -350,7 +353,7 @@ TEST(voting, threshold)
 TEST(new_blocks, denied)
 {
     TestDB db;
-    HardFork hf(db, 1, 1, 1, 4, 50);
+    HardFork hf(db, 1, 0, 1, 1, 4, 50);
 
     //                 v  h  t
     ASSERT_TRUE(hf.add(1, 0, 0));
@@ -370,13 +373,13 @@ TEST(new_blocks, denied)
     ASSERT_FALSE(hf.add(mkblock(1), 9)); // so this one can't get added
     ASSERT_TRUE(hf.add(mkblock(2), 10));
 
-    ASSERT_EQ(hf.get_start_height(2), 8);
+    ASSERT_EQ(hf.get_start_height(2), 9);
 }
 
 TEST(new_version, early)
 {
     TestDB db;
-    HardFork hf(db, 1, 1, 1, 4, 50);
+    HardFork hf(db, 1, 0, 1, 1, 4, 50);
 
     //                 v  h  t
     ASSERT_TRUE(hf.add(1, 0, 0));
@@ -399,7 +402,7 @@ TEST(new_version, early)
 TEST(reorganize, changed)
 {
     TestDB db;
-    HardFork hf(db, 1, 1, 1, 4, 50);
+    HardFork hf(db, 1, 0, 1, 1, 4, 50);
 
     //                 v  h  t
     ASSERT_TRUE(hf.add(1, 0, 0));
@@ -428,8 +431,8 @@ TEST(reorganize, changed)
     ADD_TRUE(3, 7);
     ADD_TRUE(4, 8);
     ADD_TRUE(4, 9);
-    ASSERT_EQ(hf.get_start_height(2), 3);
-    ASSERT_EQ(hf.get_start_height(3), 8);
+    ASSERT_EQ(hf.get_start_height(2), 4); // reaches threshold 2 at height 3, so height 4 forks
+    ASSERT_EQ(hf.get_start_height(3), 9);
     ASSERT_EQ(hf.get_current_version(), 3);
 
     // pop a few blocks and check current version goes back down
@@ -446,7 +449,7 @@ TEST(reorganize, changed)
     ADD_TRUE(2, 7);
     ADD_TRUE(2, 8);
     ADD_TRUE(2, 9);
-    ASSERT_EQ(hf.get_start_height(2), 3); // unchanged
+    ASSERT_EQ(hf.get_start_height(2), 4); // unchanged
     ASSERT_EQ(hf.get_current_version(), 2); // we did not bump to 3 this time
     ASSERT_EQ(hf.get_start_height(3), std::numeric_limits<uint64_t>::max()); // not yet
 }