text: // Copyright (c) 2011-2017 The Bitcash Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  // Unit tests for denial-of-service detection/prevention code
  
  #include <chainparams.h>
  #include <keystore.h>
  #include <net.h>
  #include <net_processing.h>
  #include <pow.h>
  #include <script/sign.h>
  #include <serialize.h>
  #include <util.h>
  #include <validation.h>
  
  #include <test/test_bitcash.h>
  
  #include <stdint.h>
  
  #include <boost/test/unit_test.hpp>
  
  // Tests these internal-to-net_processing.cpp methods:
  extern bool AddOrphanTx(const CTransactionRef& tx, NodeId peer);
  extern void EraseOrphansFor(NodeId peer);
  extern unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans);
  struct COrphanTx {
      CTransactionRef tx;
      NodeId fromPeer;
      int64_t nTimeExpire;
  };
  extern std::map<uint256, COrphanTx> mapOrphanTransactions;
  
  static CService ip(uint32_t i)
  {
      struct in_addr s;
      s.s_addr = i;
      return CService(CNetAddr(s), Params().GetDefaultPort());
  }
  
  static NodeId id = 0;
  
  void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds);
  
  BOOST_FIXTURE_TEST_SUITE(DoS_tests, TestingSetup)
  
  // Test eviction of an outbound peer whose chain never advances
  // Mock a node connection, and use mocktime to simulate a peer
  // which never sends any headers messages.  PeerLogic should
  // decide to evict that outbound peer, after the appropriate timeouts.
  // Note that we protect 4 outbound nodes from being subject to
  // this logic; this test takes advantage of that protection only
  // being applied to nodes which send headers with sufficient
  // work.
  BOOST_AUTO_TEST_CASE(outbound_slow_chain_eviction)
  {
      std::atomic<bool> interruptDummy(false);
  
      // Mock an outbound peer
      CAddress addr1(ip(0xa0b0c001), NODE_NONE);
      CNode dummyNode1(id++, ServiceFlags(NODE_NETWORK|NODE_WITNESS), 0, INVALID_SOCKET, addr1, 0, 0, CAddress(), "", /*fInboundIn=*/ false);
      dummyNode1.SetSendVersion(PROTOCOL_VERSION);
  
      peerLogic->InitializeNode(&dummyNode1);
      dummyNode1.nVersion = 1;
      dummyNode1.fSuccessfullyConnected = true;
  
      // This test requires that we have a chain with non-zero work.
      LOCK(cs_main);
      BOOST_CHECK(chainActive.Tip() != nullptr);
      BOOST_CHECK(chainActive.Tip()->nChainWork > 0);
  
      // Test starts here
      LOCK(dummyNode1.cs_sendProcessing);
      peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in getheaders
      LOCK(dummyNode1.cs_vSend);
      BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
      dummyNode1.vSendMsg.clear();
  
      int64_t nStartTime = GetTime();
      // Wait 21 minutes
      SetMockTime(nStartTime+21*60);
      peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in getheaders
      BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
      // Wait 3 more minutes
      SetMockTime(nStartTime+24*60);
      peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in disconnect
      BOOST_CHECK(dummyNode1.fDisconnect == true);
      SetMockTime(0);
  
      bool dummy;
      peerLogic->FinalizeNode(dummyNode1.GetId(), dummy);
  }
  
  static void AddRandomOutboundPeer(std::vector<CNode *> &vNodes, PeerLogicValidation &peerLogic)
  {
      CAddress addr(ip(GetRandInt(0xffffffff)), NODE_NONE);
      vNodes.emplace_back(new CNode(id++, ServiceFlags(NODE_NETWORK|NODE_WITNESS), 0, INVALID_SOCKET, addr, 0, 0, CAddress(), "", /*fInboundIn=*/ false));
      CNode &node = *vNodes.back();
      node.SetSendVersion(PROTOCOL_VERSION);
  
      peerLogic.InitializeNode(&node);
      node.nVersion = 1;
      node.fSuccessfullyConnected = true;
  
      CConnmanTest::AddNode(node);
  }
  
  BOOST_AUTO_TEST_CASE(stale_tip_peer_management)
  {
      const Consensus::Params& consensusParams = Params().GetConsensus();
      constexpr int nMaxOutbound = 8;
      CConnman::Options options;
      options.nMaxConnections = 125;
      options.nMaxOutbound = nMaxOutbound;
      options.nMaxFeeler = 1;
  
      connman->Init(options);
      std::vector<CNode *> vNodes;
  
      // Mock some outbound peers
      for (int i=0; i<nMaxOutbound; ++i) {
          AddRandomOutboundPeer(vNodes, *peerLogic);
      }
  
      peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
  
      // No nodes should be marked for disconnection while we have no extra peers
      for (const CNode *node : vNodes) {
          BOOST_CHECK(node->fDisconnect == false);
      }
  
      SetMockTime(GetTime() + 3*consensusParams.nPowTargetSpacing + 1);
  
      // Now tip should definitely be stale, and we should look for an extra
      // outbound peer
      peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
      BOOST_CHECK(connman->GetTryNewOutboundPeer());
  
      // Still no peers should be marked for disconnection
      for (const CNode *node : vNodes) {
          BOOST_CHECK(node->fDisconnect == false);
      }
  
      // If we add one more peer, something should get marked for eviction
      // on the next check (since we're mocking the time to be in the future, the
      // required time connected check should be satisfied).
      AddRandomOutboundPeer(vNodes, *peerLogic);
  
      peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
      for (int i=0; i<nMaxOutbound; ++i) {
          BOOST_CHECK(vNodes[i]->fDisconnect == false);
      }
      // Last added node should get marked for eviction
      BOOST_CHECK(vNodes.back()->fDisconnect == true);
  
      vNodes.back()->fDisconnect = false;
  
      // Update the last announced block time for the last
      // peer, and check that the next newest node gets evicted.
      UpdateLastBlockAnnounceTime(vNodes.back()->GetId(), GetTime());
  
      peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
      for (int i=0; i<nMaxOutbound-1; ++i) {
          BOOST_CHECK(vNodes[i]->fDisconnect == false);
      }
      BOOST_CHECK(vNodes[nMaxOutbound-1]->fDisconnect == true);
      BOOST_CHECK(vNodes.back()->fDisconnect == false);
  
      bool dummy;
      for (const CNode *node : vNodes) {
          peerLogic->FinalizeNode(node->GetId(), dummy);
      }
  
      CConnmanTest::ClearNodes();
  }
  
  BOOST_AUTO_TEST_CASE(DoS_banning)
  {
      std::atomic<bool> interruptDummy(false);
  
      connman->ClearBanned();
      CAddress addr1(ip(0xa0b0c001), NODE_NONE);
      CNode dummyNode1(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr1, 0, 0, CAddress(), "", true);
      dummyNode1.SetSendVersion(PROTOCOL_VERSION);
      peerLogic->InitializeNode(&dummyNode1);
      dummyNode1.nVersion = 1;
      dummyNode1.fSuccessfullyConnected = true;
      {
          LOCK(cs_main);
          Misbehaving(dummyNode1.GetId(), 100); // Should get banned
      }
      LOCK(dummyNode1.cs_sendProcessing);
      peerLogic->SendMessages(&dummyNode1, interruptDummy);
      BOOST_CHECK(connman->IsBanned(addr1));
      BOOST_CHECK(!connman->IsBanned(ip(0xa0b0c001|0x0000ff00))); // Different IP, not banned
  
      CAddress addr2(ip(0xa0b0c002), NODE_NONE);
      CNode dummyNode2(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr2, 1, 1, CAddress(), "", true);
      dummyNode2.SetSendVersion(PROTOCOL_VERSION);
      peerLogic->InitializeNode(&dummyNode2);
      dummyNode2.nVersion = 1;
      dummyNode2.fSuccessfullyConnected = true;
      {
          LOCK(cs_main);
          Misbehaving(dummyNode2.GetId(), 50);
      }
      LOCK(dummyNode2.cs_sendProcessing);
      peerLogic->SendMessages(&dummyNode2, interruptDummy);
      BOOST_CHECK(!connman->IsBanned(addr2)); // 2 not banned yet...
      BOOST_CHECK(connman->IsBanned(addr1));  // ... but 1 still should be
      {
          LOCK(cs_main);
          Misbehaving(dummyNode2.GetId(), 50);
      }
      peerLogic->SendMessages(&dummyNode2, interruptDummy);
      BOOST_CHECK(connman->IsBanned(addr2));
  
      bool dummy;
      peerLogic->FinalizeNode(dummyNode1.GetId(), dummy);
      peerLogic->FinalizeNode(dummyNode2.GetId(), dummy);
  }
  
  BOOST_AUTO_TEST_CASE(DoS_banscore)
  {
      std::atomic<bool> interruptDummy(false);
  
      connman->ClearBanned();
      gArgs.ForceSetArg("-banscore", "111"); // because 11 is my favorite number
      CAddress addr1(ip(0xa0b0c001), NODE_NONE);
      CNode dummyNode1(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr1, 3, 1, CAddress(), "", true);
      dummyNode1.SetSendVersion(PROTOCOL_VERSION);
      peerLogic->InitializeNode(&dummyNode1);
      dummyNode1.nVersion = 1;
      dummyNode1.fSuccessfullyConnected = true;
      {
          LOCK(cs_main);
          Misbehaving(dummyNode1.GetId(), 100);
      }
      LOCK(dummyNode1.cs_sendProcessing);
      peerLogic->SendMessages(&dummyNode1, interruptDummy);
      BOOST_CHECK(!connman->IsBanned(addr1));
      {
          LOCK(cs_main);
          Misbehaving(dummyNode1.GetId(), 10);
      }
      peerLogic->SendMessages(&dummyNode1, interruptDummy);
      BOOST_CHECK(!connman->IsBanned(addr1));
      {
          LOCK(cs_main);
          Misbehaving(dummyNode1.GetId(), 1);
      }
      peerLogic->SendMessages(&dummyNode1, interruptDummy);
      BOOST_CHECK(connman->IsBanned(addr1));
      gArgs.ForceSetArg("-banscore", std::to_string(DEFAULT_BANSCORE_THRESHOLD));
  
      bool dummy;
      peerLogic->FinalizeNode(dummyNode1.GetId(), dummy);
  }
  
  BOOST_AUTO_TEST_CASE(DoS_bantime)
  {
      std::atomic<bool> interruptDummy(false);
  
      connman->ClearBanned();
      int64_t nStartTime = GetTime();
      SetMockTime(nStartTime); // Overrides future calls to GetTime()
  
      CAddress addr(ip(0xa0b0c001), NODE_NONE);
      CNode dummyNode(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr, 4, 4, CAddress(), "", true);
      dummyNode.SetSendVersion(PROTOCOL_VERSION);
      peerLogic->InitializeNode(&dummyNode);
      dummyNode.nVersion = 1;
      dummyNode.fSuccessfullyConnected = true;
  
      {
          LOCK(cs_main);
          Misbehaving(dummyNode.GetId(), 100);
      }
      LOCK(dummyNode.cs_sendProcessing);
      peerLogic->SendMessages(&dummyNode, interruptDummy);
      BOOST_CHECK(connman->IsBanned(addr));
  
      SetMockTime(nStartTime+60*60);
      BOOST_CHECK(connman->IsBanned(addr));
  
      SetMockTime(nStartTime+60*60*24+1);
      BOOST_CHECK(!connman->IsBanned(addr));
  
      bool dummy;
      peerLogic->FinalizeNode(dummyNode.GetId(), dummy);
  }
  
  static CTransactionRef RandomOrphan()
  {
      std::map<uint256, COrphanTx>::iterator it;
      LOCK(cs_main);
      it = mapOrphanTransactions.lower_bound(InsecureRand256());
      if (it == mapOrphanTransactions.end())
          it = mapOrphanTransactions.begin();
      return it->second.tx;
  }
  
  BOOST_AUTO_TEST_CASE(DoS_mapOrphans)
  {
      CKey key;
      key.MakeNewKey(true);
      CBasicKeyStore keystore;
      keystore.AddKey(key);
  
      // 50 orphan transactions:
      for (int i = 0; i < 50; i++)
      {
          CMutableTransaction tx;
          tx.vin.resize(1);
          tx.vin[0].prevout.n = 0;
          tx.vin[0].prevout.hash = InsecureRand256();
          tx.vin[0].scriptSig << OP_1;
          tx.vout.resize(1);
          tx.vout[0].nValue = 1*CENT;
          tx.vout[0].scriptPubKey = GetScriptForDestination(key.GetPubKey().GetID());
  
          AddOrphanTx(MakeTransactionRef(tx), i);
      }
  
      // ... and 50 that depend on other orphans:
      for (int i = 0; i < 50; i++)
      {
          CTransactionRef txPrev = RandomOrphan();
  
          CMutableTransaction tx;
          tx.vin.resize(1);
          tx.vin[0].prevout.n = 0;
          tx.vin[0].prevout.hash = txPrev->GetHash();
          tx.vout.resize(1);
          tx.vout[0].nValue = 1*CENT;
          tx.vout[0].scriptPubKey = GetScriptForDestination(key.GetPubKey().GetID());
          SignSignature(keystore, *txPrev, tx, 0, SIGHASH_ALL);
  
          AddOrphanTx(MakeTransactionRef(tx), i);
      }
  
      // This really-big orphan should be ignored:
      for (int i = 0; i < 10; i++)
      {
          CTransactionRef txPrev = RandomOrphan();
  
          CMutableTransaction tx;
          tx.vout.resize(1);
          tx.vout[0].nValue = 1*CENT;
          tx.vout[0].scriptPubKey = GetScriptForDestination(key.GetPubKey().GetID());
          tx.vin.resize(2777);
          for (unsigned int j = 0; j < tx.vin.size(); j++)
          {
              tx.vin[j].prevout.n = j;
              tx.vin[j].prevout.hash = txPrev->GetHash();
          }
          SignSignature(keystore, *txPrev, tx, 0, SIGHASH_ALL);
          // Re-use same signature for other inputs
          // (they don't have to be valid for this test)
          for (unsigned int j = 1; j < tx.vin.size(); j++)
              tx.vin[j].scriptSig = tx.vin[0].scriptSig;
  
          BOOST_CHECK(!AddOrphanTx(MakeTransactionRef(tx), i));
      }
  
      LOCK(cs_main);
      // Test EraseOrphansFor:
      for (NodeId i = 0; i < 3; i++)
      {
          size_t sizeBefore = mapOrphanTransactions.size();
          EraseOrphansFor(i);
          BOOST_CHECK(mapOrphanTransactions.size() < sizeBefore);
      }
  
      // Test LimitOrphanTxSize() function:
      LimitOrphanTxSize(40);
      BOOST_CHECK(mapOrphanTransactions.size() <= 40);
      LimitOrphanTxSize(10);
      BOOST_CHECK(mapOrphanTransactions.size() <= 10);
      LimitOrphanTxSize(0);
      BOOST_CHECK(mapOrphanTransactions.empty());
  }
  
  BOOST_AUTO_TEST_SUITE_END()
  