/ src / test / denialofservice_tests.cpp
denialofservice_tests.cpp
  1  // Copyright (c) 2011-present The Bitcoin Core developers
  2  // Distributed under the MIT software license, see the accompanying
  3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  4  
  5  // Unit tests for denial-of-service detection/prevention code
  6  
  7  #include <banman.h>
  8  #include <chainparams.h>
  9  #include <common/args.h>
 10  #include <net.h>
 11  #include <net_processing.h>
 12  #include <pubkey.h>
 13  #include <script/sign.h>
 14  #include <script/signingprovider.h>
 15  #include <serialize.h>
 16  #include <test/util/net.h>
 17  #include <test/util/random.h>
 18  #include <test/util/setup_common.h>
 19  #include <util/string.h>
 20  #include <util/time.h>
 21  #include <validation.h>
 22  
 23  #include <array>
 24  #include <cstdint>
 25  
 26  #include <boost/test/unit_test.hpp>
 27  
 28  static CService ip(uint32_t i)
 29  {
 30      struct in_addr s;
 31      s.s_addr = i;
 32      return CService(CNetAddr(s), Params().GetDefaultPort());
 33  }
 34  
 35  BOOST_FIXTURE_TEST_SUITE(denialofservice_tests, TestingSetup)
 36  
 37  // Test eviction of an outbound peer whose chain never advances
 38  // Mock a node connection, and use mocktime to simulate a peer
 39  // which never sends any headers messages.  PeerLogic should
 40  // decide to evict that outbound peer, after the appropriate timeouts.
 41  // Note that we protect 4 outbound nodes from being subject to
 42  // this logic; this test takes advantage of that protection only
 43  // being applied to nodes which send headers with sufficient
 44  // work.
 45  BOOST_AUTO_TEST_CASE(outbound_slow_chain_eviction)
 46  {
 47      LOCK(NetEventsInterface::g_msgproc_mutex);
 48  
 49      ConnmanTestMsg& connman = static_cast<ConnmanTestMsg&>(*m_node.connman);
 50      // Disable inactivity checks for this test to avoid interference
 51      connman.SetPeerConnectTimeout(99999s);
 52      PeerManager& peerman = *m_node.peerman;
 53  
 54      // Mock an outbound peer
 55      CAddress addr1(ip(0xa0b0c001), NODE_NONE);
 56      NodeId id{0};
 57      CNode dummyNode1{id++,
 58                       /*sock=*/nullptr,
 59                       addr1,
 60                       /*nKeyedNetGroupIn=*/0,
 61                       /*nLocalHostNonceIn=*/0,
 62                       CAddress(),
 63                       /*addrNameIn=*/"",
 64                       ConnectionType::OUTBOUND_FULL_RELAY,
 65                       /*inbound_onion=*/false,
 66                       /*network_key=*/0};
 67  
 68      connman.Handshake(
 69          /*node=*/dummyNode1,
 70          /*successfully_connected=*/true,
 71          /*remote_services=*/ServiceFlags(NODE_NETWORK | NODE_WITNESS),
 72          /*local_services=*/ServiceFlags(NODE_NETWORK | NODE_WITNESS),
 73          /*version=*/PROTOCOL_VERSION,
 74          /*relay_txs=*/true);
 75  
 76      // This test requires that we have a chain with non-zero work.
 77      {
 78          LOCK(cs_main);
 79          BOOST_CHECK(m_node.chainman->ActiveChain().Tip() != nullptr);
 80          BOOST_CHECK(m_node.chainman->ActiveChain().Tip()->nChainWork > 0);
 81      }
 82  
 83      // Test starts here
 84      BOOST_CHECK(peerman.SendMessages(dummyNode1)); // should result in getheaders
 85  
 86      {
 87          LOCK(dummyNode1.cs_vSend);
 88          const auto& [to_send, _more, _msg_type] = dummyNode1.m_transport->GetBytesToSend(false);
 89          BOOST_CHECK(!to_send.empty());
 90      }
 91      connman.FlushSendBuffer(dummyNode1);
 92  
 93      int64_t nStartTime = GetTime();
 94      // Wait 21 minutes
 95      SetMockTime(nStartTime+21*60);
 96      BOOST_CHECK(peerman.SendMessages(dummyNode1)); // should result in getheaders
 97      {
 98          LOCK(dummyNode1.cs_vSend);
 99          const auto& [to_send, _more, _msg_type] = dummyNode1.m_transport->GetBytesToSend(false);
100          BOOST_CHECK(!to_send.empty());
101      }
102      // Wait 3 more minutes
103      SetMockTime(nStartTime+24*60);
104      BOOST_CHECK(peerman.SendMessages(dummyNode1)); // should result in disconnect
105      BOOST_CHECK(dummyNode1.fDisconnect == true);
106  
107      peerman.FinalizeNode(dummyNode1);
108  }
109  
110  struct OutboundTest : TestingSetup {
111  void AddRandomOutboundPeer(NodeId& id, std::vector<CNode*>& vNodes, PeerManager& peerLogic, ConnmanTestMsg& connman, ConnectionType connType, bool onion_peer = false)
112  {
113      CAddress addr;
114  
115      if (onion_peer) {
116          auto tor_addr{m_rng.randbytes(ADDR_TORV3_SIZE)};
117          BOOST_REQUIRE(addr.SetSpecial(OnionToString(tor_addr)));
118      }
119  
120      while (!addr.IsRoutable()) {
121          addr = CAddress(ip(m_rng.randbits(32)), NODE_NONE);
122      }
123  
124      vNodes.emplace_back(new CNode{id++,
125                                    /*sock=*/nullptr,
126                                    addr,
127                                    /*nKeyedNetGroupIn=*/0,
128                                    /*nLocalHostNonceIn=*/0,
129                                    CAddress(),
130                                    /*addrNameIn=*/"",
131                                    connType,
132                                    /*inbound_onion=*/false,
133                                    /*network_key=*/0});
134      CNode &node = *vNodes.back();
135      node.SetCommonVersion(PROTOCOL_VERSION);
136  
137      peerLogic.InitializeNode(node, ServiceFlags(NODE_NETWORK | NODE_WITNESS));
138      node.fSuccessfullyConnected = true;
139  
140      connman.AddTestNode(node);
141  }
142  }; // struct OutboundTest
143  
144  BOOST_FIXTURE_TEST_CASE(stale_tip_peer_management, OutboundTest)
145  {
146      NodeId id{0};
147      auto connman = std::make_unique<ConnmanTestMsg>(0x1337, 0x1337, *m_node.addrman, *m_node.netgroupman, Params());
148      auto peerLogic = PeerManager::make(*connman, *m_node.addrman, nullptr, *m_node.chainman, *m_node.mempool, *m_node.warnings, {});
149  
150      constexpr int max_outbound_full_relay = MAX_OUTBOUND_FULL_RELAY_CONNECTIONS;
151      CConnman::Options options;
152      options.m_max_automatic_connections = DEFAULT_MAX_PEER_CONNECTIONS;
153  
154      const auto time_init{GetTime<std::chrono::seconds>()};
155      SetMockTime(time_init);
156      const auto time_later{time_init + 3 * std::chrono::seconds{m_node.chainman->GetConsensus().nPowTargetSpacing} + 1s};
157      connman->Init(options);
158      std::vector<CNode *> vNodes;
159  
160      // Mock some outbound peers
161      for (int i = 0; i < max_outbound_full_relay; ++i) {
162          AddRandomOutboundPeer(id, vNodes, *peerLogic, *connman, ConnectionType::OUTBOUND_FULL_RELAY);
163      }
164  
165      peerLogic->CheckForStaleTipAndEvictPeers();
166  
167      // No nodes should be marked for disconnection while we have no extra peers
168      for (const CNode *node : vNodes) {
169          BOOST_CHECK(node->fDisconnect == false);
170      }
171  
172      SetMockTime(time_later);
173  
174      // Now tip should definitely be stale, and we should look for an extra
175      // outbound peer
176      peerLogic->CheckForStaleTipAndEvictPeers();
177      BOOST_CHECK(connman->GetTryNewOutboundPeer());
178  
179      // Still no peers should be marked for disconnection
180      for (const CNode *node : vNodes) {
181          BOOST_CHECK(node->fDisconnect == false);
182      }
183  
184      // If we add one more peer, something should get marked for eviction
185      // on the next check (since we're mocking the time to be in the future, the
186      // required time connected check should be satisfied).
187      SetMockTime(time_init);
188      AddRandomOutboundPeer(id, vNodes, *peerLogic, *connman, ConnectionType::OUTBOUND_FULL_RELAY);
189      SetMockTime(time_later);
190  
191      peerLogic->CheckForStaleTipAndEvictPeers();
192      for (int i = 0; i < max_outbound_full_relay; ++i) {
193          BOOST_CHECK(vNodes[i]->fDisconnect == false);
194      }
195      // Last added node should get marked for eviction
196      BOOST_CHECK(vNodes.back()->fDisconnect == true);
197  
198      vNodes.back()->fDisconnect = false;
199  
200      // Update the last announced block time for the last
201      // peer, and check that the next newest node gets evicted.
202      peerLogic->UpdateLastBlockAnnounceTime(vNodes.back()->GetId(), GetTime());
203  
204      peerLogic->CheckForStaleTipAndEvictPeers();
205      for (int i = 0; i < max_outbound_full_relay - 1; ++i) {
206          BOOST_CHECK(vNodes[i]->fDisconnect == false);
207      }
208      BOOST_CHECK(vNodes[max_outbound_full_relay-1]->fDisconnect == true);
209      BOOST_CHECK(vNodes.back()->fDisconnect == false);
210  
211      vNodes[max_outbound_full_relay - 1]->fDisconnect = false;
212  
213      // Add an onion peer, that will be protected because it is the only one for
214      // its network, so another peer gets disconnected instead.
215      SetMockTime(time_init);
216      AddRandomOutboundPeer(id, vNodes, *peerLogic, *connman, ConnectionType::OUTBOUND_FULL_RELAY, /*onion_peer=*/true);
217      SetMockTime(time_later);
218      peerLogic->CheckForStaleTipAndEvictPeers();
219  
220      for (int i = 0; i < max_outbound_full_relay - 2; ++i) {
221          BOOST_CHECK(vNodes[i]->fDisconnect == false);
222      }
223      BOOST_CHECK(vNodes[max_outbound_full_relay - 2]->fDisconnect == false);
224      BOOST_CHECK(vNodes[max_outbound_full_relay - 1]->fDisconnect == true);
225      BOOST_CHECK(vNodes[max_outbound_full_relay]->fDisconnect == false);
226  
227      // Add a second onion peer which won't be protected
228      SetMockTime(time_init);
229      AddRandomOutboundPeer(id, vNodes, *peerLogic, *connman, ConnectionType::OUTBOUND_FULL_RELAY, /*onion_peer=*/true);
230      SetMockTime(time_later);
231      peerLogic->CheckForStaleTipAndEvictPeers();
232  
233      BOOST_CHECK(vNodes.back()->fDisconnect == true);
234  
235      for (const CNode *node : vNodes) {
236          peerLogic->FinalizeNode(*node);
237      }
238  
239      connman->ClearTestNodes();
240  }
241  
242  BOOST_FIXTURE_TEST_CASE(block_relay_only_eviction, OutboundTest)
243  {
244      NodeId id{0};
245      auto connman = std::make_unique<ConnmanTestMsg>(0x1337, 0x1337, *m_node.addrman, *m_node.netgroupman, Params());
246      auto peerLogic = PeerManager::make(*connman, *m_node.addrman, nullptr, *m_node.chainman, *m_node.mempool, *m_node.warnings, {});
247  
248      constexpr int max_outbound_block_relay{MAX_BLOCK_RELAY_ONLY_CONNECTIONS};
249      constexpr int64_t MINIMUM_CONNECT_TIME{30};
250      CConnman::Options options;
251      options.m_max_automatic_connections = DEFAULT_MAX_PEER_CONNECTIONS;
252  
253      connman->Init(options);
254      std::vector<CNode*> vNodes;
255  
256      // Add block-relay-only peers up to the limit
257      for (int i = 0; i < max_outbound_block_relay; ++i) {
258          AddRandomOutboundPeer(id, vNodes, *peerLogic, *connman, ConnectionType::BLOCK_RELAY);
259      }
260      peerLogic->CheckForStaleTipAndEvictPeers();
261  
262      for (int i = 0; i < max_outbound_block_relay; ++i) {
263          BOOST_CHECK(vNodes[i]->fDisconnect == false);
264      }
265  
266      // Add an extra block-relay-only peer breaking the limit (mocks logic in ThreadOpenConnections)
267      AddRandomOutboundPeer(id, vNodes, *peerLogic, *connman, ConnectionType::BLOCK_RELAY);
268      peerLogic->CheckForStaleTipAndEvictPeers();
269  
270      // The extra peer should only get marked for eviction after MINIMUM_CONNECT_TIME
271      for (int i = 0; i < max_outbound_block_relay; ++i) {
272          BOOST_CHECK(vNodes[i]->fDisconnect == false);
273      }
274      BOOST_CHECK(vNodes.back()->fDisconnect == false);
275  
276      SetMockTime(GetTime() + MINIMUM_CONNECT_TIME + 1);
277      peerLogic->CheckForStaleTipAndEvictPeers();
278      for (int i = 0; i < max_outbound_block_relay; ++i) {
279          BOOST_CHECK(vNodes[i]->fDisconnect == false);
280      }
281      BOOST_CHECK(vNodes.back()->fDisconnect == true);
282  
283      // Update the last block time for the extra peer,
284      // and check that the next youngest peer gets evicted.
285      vNodes.back()->fDisconnect = false;
286      vNodes.back()->m_last_block_time = GetTime<std::chrono::seconds>();
287  
288      peerLogic->CheckForStaleTipAndEvictPeers();
289      for (int i = 0; i < max_outbound_block_relay - 1; ++i) {
290          BOOST_CHECK(vNodes[i]->fDisconnect == false);
291      }
292      BOOST_CHECK(vNodes[max_outbound_block_relay - 1]->fDisconnect == true);
293      BOOST_CHECK(vNodes.back()->fDisconnect == false);
294  
295      for (const CNode* node : vNodes) {
296          peerLogic->FinalizeNode(*node);
297      }
298      connman->ClearTestNodes();
299  }
300  
301  BOOST_AUTO_TEST_CASE(peer_discouragement)
302  {
303      LOCK(NetEventsInterface::g_msgproc_mutex);
304  
305      auto banman = std::make_unique<BanMan>(m_args.GetDataDirBase() / "banlist", nullptr, DEFAULT_MISBEHAVING_BANTIME);
306      auto connman = std::make_unique<ConnmanTestMsg>(0x1337, 0x1337, *m_node.addrman, *m_node.netgroupman, Params());
307      auto peerLogic = PeerManager::make(*connman, *m_node.addrman, banman.get(), *m_node.chainman, *m_node.mempool, *m_node.warnings, {});
308  
309      CNetAddr tor_netaddr;
310      BOOST_REQUIRE(
311          tor_netaddr.SetSpecial("pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion"));
312      const CService tor_service{tor_netaddr, Params().GetDefaultPort()};
313  
314      const std::array<CAddress, 3> addr{CAddress{ip(0xa0b0c001), NODE_NONE},
315                                         CAddress{ip(0xa0b0c002), NODE_NONE},
316                                         CAddress{tor_service, NODE_NONE}};
317  
318      const CNetAddr other_addr{ip(0xa0b0ff01)}; // Not any of addr[].
319  
320      std::array<CNode*, 3> nodes;
321  
322      banman->ClearBanned();
323      NodeId id{0};
324      nodes[0] = new CNode{id++,
325                           /*sock=*/nullptr,
326                           addr[0],
327                           /*nKeyedNetGroupIn=*/0,
328                           /*nLocalHostNonceIn=*/0,
329                           CAddress(),
330                           /*addrNameIn=*/"",
331                           ConnectionType::INBOUND,
332                           /*inbound_onion=*/false,
333                           /*network_key=*/1};
334      nodes[0]->SetCommonVersion(PROTOCOL_VERSION);
335      peerLogic->InitializeNode(*nodes[0], NODE_NETWORK);
336      nodes[0]->fSuccessfullyConnected = true;
337      connman->AddTestNode(*nodes[0]);
338      peerLogic->UnitTestMisbehaving(nodes[0]->GetId()); // Should be discouraged
339      BOOST_CHECK(peerLogic->SendMessages(*nodes[0]));
340  
341      BOOST_CHECK(banman->IsDiscouraged(addr[0]));
342      BOOST_CHECK(nodes[0]->fDisconnect);
343      BOOST_CHECK(!banman->IsDiscouraged(other_addr)); // Different address, not discouraged
344  
345      nodes[1] = new CNode{id++,
346                           /*sock=*/nullptr,
347                           addr[1],
348                           /*nKeyedNetGroupIn=*/1,
349                           /*nLocalHostNonceIn=*/1,
350                           CAddress(),
351                           /*addrNameIn=*/"",
352                           ConnectionType::INBOUND,
353                           /*inbound_onion=*/false,
354                           /*network_key=*/1};
355      nodes[1]->SetCommonVersion(PROTOCOL_VERSION);
356      peerLogic->InitializeNode(*nodes[1], NODE_NETWORK);
357      nodes[1]->fSuccessfullyConnected = true;
358      connman->AddTestNode(*nodes[1]);
359      BOOST_CHECK(peerLogic->SendMessages(*nodes[1]));
360      // [0] is still discouraged/disconnected.
361      BOOST_CHECK(banman->IsDiscouraged(addr[0]));
362      BOOST_CHECK(nodes[0]->fDisconnect);
363      // [1] is not discouraged/disconnected yet.
364      BOOST_CHECK(!banman->IsDiscouraged(addr[1]));
365      BOOST_CHECK(!nodes[1]->fDisconnect);
366      peerLogic->UnitTestMisbehaving(nodes[1]->GetId());
367      BOOST_CHECK(peerLogic->SendMessages(*nodes[1]));
368      // Expect both [0] and [1] to be discouraged/disconnected now.
369      BOOST_CHECK(banman->IsDiscouraged(addr[0]));
370      BOOST_CHECK(nodes[0]->fDisconnect);
371      BOOST_CHECK(banman->IsDiscouraged(addr[1]));
372      BOOST_CHECK(nodes[1]->fDisconnect);
373  
374      // Make sure non-IP peers are discouraged and disconnected properly.
375  
376      nodes[2] = new CNode{id++,
377                           /*sock=*/nullptr,
378                           addr[2],
379                           /*nKeyedNetGroupIn=*/1,
380                           /*nLocalHostNonceIn=*/1,
381                           CAddress(),
382                           /*addrNameIn=*/"",
383                           ConnectionType::OUTBOUND_FULL_RELAY,
384                           /*inbound_onion=*/false,
385                           /*network_key=*/2};
386      nodes[2]->SetCommonVersion(PROTOCOL_VERSION);
387      peerLogic->InitializeNode(*nodes[2], NODE_NETWORK);
388      nodes[2]->fSuccessfullyConnected = true;
389      connman->AddTestNode(*nodes[2]);
390      peerLogic->UnitTestMisbehaving(nodes[2]->GetId());
391      BOOST_CHECK(peerLogic->SendMessages(*nodes[2]));
392      BOOST_CHECK(banman->IsDiscouraged(addr[0]));
393      BOOST_CHECK(banman->IsDiscouraged(addr[1]));
394      BOOST_CHECK(banman->IsDiscouraged(addr[2]));
395      BOOST_CHECK(nodes[0]->fDisconnect);
396      BOOST_CHECK(nodes[1]->fDisconnect);
397      BOOST_CHECK(nodes[2]->fDisconnect);
398  
399      for (CNode* node : nodes) {
400          peerLogic->FinalizeNode(*node);
401      }
402      connman->ClearTestNodes();
403  }
404  
405  BOOST_AUTO_TEST_CASE(DoS_bantime)
406  {
407      LOCK(NetEventsInterface::g_msgproc_mutex);
408  
409      auto banman = std::make_unique<BanMan>(m_args.GetDataDirBase() / "banlist", nullptr, DEFAULT_MISBEHAVING_BANTIME);
410      auto connman = std::make_unique<CConnman>(0x1337, 0x1337, *m_node.addrman, *m_node.netgroupman, Params());
411      auto peerLogic = PeerManager::make(*connman, *m_node.addrman, banman.get(), *m_node.chainman, *m_node.mempool, *m_node.warnings, {});
412  
413      banman->ClearBanned();
414      int64_t nStartTime = GetTime();
415      SetMockTime(nStartTime); // Overrides future calls to GetTime()
416  
417      CAddress addr(ip(0xa0b0c001), NODE_NONE);
418      NodeId id{0};
419      CNode dummyNode{id++,
420                      /*sock=*/nullptr,
421                      addr,
422                      /*nKeyedNetGroupIn=*/4,
423                      /*nLocalHostNonceIn=*/4,
424                      CAddress(),
425                      /*addrNameIn=*/"",
426                      ConnectionType::INBOUND,
427                      /*inbound_onion=*/false,
428                      /*network_key=*/1};
429      dummyNode.SetCommonVersion(PROTOCOL_VERSION);
430      peerLogic->InitializeNode(dummyNode, NODE_NETWORK);
431      dummyNode.fSuccessfullyConnected = true;
432  
433      peerLogic->UnitTestMisbehaving(dummyNode.GetId());
434      BOOST_CHECK(peerLogic->SendMessages(dummyNode));
435      BOOST_CHECK(banman->IsDiscouraged(addr));
436  
437      peerLogic->FinalizeNode(dummyNode);
438  }
439  
440  BOOST_AUTO_TEST_SUITE_END()