src/test/DoS_tests.cpp

   1 // Copyright (c) 2011-2017 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 <chainparams.h>
   8 #include <keystore.h>
   9 #include <net.h>
  10 #include <net_processing.h>
  11 #include <pow.h>
  12 #include <script/sign.h>
  13 #include <serialize.h>
  14 #include <util.h>
  15 #include <validation.h>
  16
  17 #include <test/test_bitcoin.h>
  18
  19 #include <stdint.h>
  20
  21 #include <boost/test/unit_test.hpp>
  22
  23 // Tests these internal-to-net_processing.cpp methods:
  24 extern bool AddOrphanTx(const CTransactionRef& tx, NodeId peer);
  25 extern void EraseOrphansFor(NodeId peer);
  26 extern unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans);
  27 struct COrphanTx {
  28     CTransactionRef tx;
  29     NodeId fromPeer;
  30     int64_t nTimeExpire;
  31 };
  32 extern std::map<uint256, COrphanTx> mapOrphanTransactions;
  33
  34 CService ip(uint32_t i)
  35 {
  36     struct in_addr s;
  37     s.s_addr = i;
  38     return CService(CNetAddr(s), Params().GetDefaultPort());
  39 }
  40
  41 static NodeId id = 0;
  42
  43 void UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_seconds);
  44
  45 BOOST_FIXTURE_TEST_SUITE(DoS_tests, TestingSetup)
  46
  47 // Test eviction of an outbound peer whose chain never advances
  48 // Mock a node connection, and use mocktime to simulate a peer
  49 // which never sends any headers messages.  PeerLogic should
  50 // decide to evict that outbound peer, after the appropriate timeouts.
  51 // Note that we protect 4 outbound nodes from being subject to
  52 // this logic; this test takes advantage of that protection only
  53 // being applied to nodes which send headers with sufficient
  54 // work.
  55 BOOST_AUTO_TEST_CASE(outbound_slow_chain_eviction)
  56 {
  57     std::atomic<bool> interruptDummy(false);
  58
  59     // Mock an outbound peer
  60     CAddress addr1(ip(0xa0b0c001), NODE_NONE);
  61     CNode dummyNode1(id++, ServiceFlags(NODE_NETWORK|NODE_WITNESS), 0, INVALID_SOCKET, addr1, 0, 0, CAddress(), "", /*fInboundIn=*/ false);
  62     dummyNode1.SetSendVersion(PROTOCOL_VERSION);
  63
  64     peerLogic->InitializeNode(&dummyNode1);
  65     dummyNode1.nVersion = 1;
  66     dummyNode1.fSuccessfullyConnected = true;
  67
  68     // This test requires that we have a chain with non-zero work.
  69     LOCK(cs_main);
  70     BOOST_CHECK(chainActive.Tip() != nullptr);
  71     BOOST_CHECK(chainActive.Tip()->nChainWork > 0);
  72
  73     // Test starts here
  74     LOCK(dummyNode1.cs_sendProcessing);
  75     peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in getheaders
  76     LOCK(dummyNode1.cs_vSend);
  77     BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
  78     dummyNode1.vSendMsg.clear();
  79
  80     int64_t nStartTime = GetTime();
  81     // Wait 21 minutes
  82     SetMockTime(nStartTime+21*60);
  83     peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in getheaders
  84     BOOST_CHECK(dummyNode1.vSendMsg.size() > 0);
  85     // Wait 3 more minutes
  86     SetMockTime(nStartTime+24*60);
  87     peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in disconnect
  88     BOOST_CHECK(dummyNode1.fDisconnect == true);
  89     SetMockTime(0);
  90
  91     bool dummy;
  92     peerLogic->FinalizeNode(dummyNode1.GetId(), dummy);
  93 }
  94
  95 void AddRandomOutboundPeer(std::vector<CNode *> &vNodes, PeerLogicValidation &peerLogic)
  96 {
  97     CAddress addr(ip(GetRandInt(0xffffffff)), NODE_NONE);
  98     vNodes.emplace_back(new CNode(id++, ServiceFlags(NODE_NETWORK|NODE_WITNESS), 0, INVALID_SOCKET, addr, 0, 0, CAddress(), "", /*fInboundIn=*/ false));
  99     CNode &node = *vNodes.back();
 100     node.SetSendVersion(PROTOCOL_VERSION);
 101
 102     peerLogic.InitializeNode(&node);
 103     node.nVersion = 1;
 104     node.fSuccessfullyConnected = true;
 105
 106     CConnmanTest::AddNode(node);
 107 }
 108
 109 BOOST_AUTO_TEST_CASE(stale_tip_peer_management)
 110 {
 111     const Consensus::Params& consensusParams = Params().GetConsensus();
 112     constexpr int nMaxOutbound = 8;
 113     CConnman::Options options;
 114     options.nMaxConnections = 125;
 115     options.nMaxOutbound = nMaxOutbound;
 116     options.nMaxFeeler = 1;
 117
 118     connman->Init(options);
 119     std::vector<CNode *> vNodes;
 120
 121     // Mock some outbound peers
 122     for (int i=0; i<nMaxOutbound; ++i) {
 123         AddRandomOutboundPeer(vNodes, *peerLogic);
 124     }
 125
 126     peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
 127
 128     // No nodes should be marked for disconnection while we have no extra peers
 129     for (const CNode *node : vNodes) {
 130         BOOST_CHECK(node->fDisconnect == false);
 131     }
 132
 133     SetMockTime(GetTime() + 3*consensusParams.nPowTargetSpacing + 1);
 134
 135     // Now tip should definitely be stale, and we should look for an extra
 136     // outbound peer
 137     peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
 138     BOOST_CHECK(connman->GetTryNewOutboundPeer());
 139
 140     // Still no peers should be marked for disconnection
 141     for (const CNode *node : vNodes) {
 142         BOOST_CHECK(node->fDisconnect == false);
 143     }
 144
 145     // If we add one more peer, something should get marked for eviction
 146     // on the next check (since we're mocking the time to be in the future, the
 147     // required time connected check should be satisfied).
 148     AddRandomOutboundPeer(vNodes, *peerLogic);
 149
 150     peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
 151     for (int i=0; i<nMaxOutbound; ++i) {
 152         BOOST_CHECK(vNodes[i]->fDisconnect == false);
 153     }
 154     // Last added node should get marked for eviction
 155     BOOST_CHECK(vNodes.back()->fDisconnect == true);
 156
 157     vNodes.back()->fDisconnect = false;
 158
 159     // Update the last announced block time for the last
 160     // peer, and check that the next newest node gets evicted.
 161     UpdateLastBlockAnnounceTime(vNodes.back()->GetId(), GetTime());
 162
 163     peerLogic->CheckForStaleTipAndEvictPeers(consensusParams);
 164     for (int i=0; i<nMaxOutbound-1; ++i) {
 165         BOOST_CHECK(vNodes[i]->fDisconnect == false);
 166     }
 167     BOOST_CHECK(vNodes[nMaxOutbound-1]->fDisconnect == true);
 168     BOOST_CHECK(vNodes.back()->fDisconnect == false);
 169
 170     bool dummy;
 171     for (const CNode *node : vNodes) {
 172         peerLogic->FinalizeNode(node->GetId(), dummy);
 173     }
 174
 175     CConnmanTest::ClearNodes();
 176 }
 177
 178 BOOST_AUTO_TEST_CASE(DoS_banning)
 179 {
 180     std::atomic<bool> interruptDummy(false);
 181
 182     connman->ClearBanned();
 183     CAddress addr1(ip(0xa0b0c001), NODE_NONE);
 184     CNode dummyNode1(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr1, 0, 0, CAddress(), "", true);
 185     dummyNode1.SetSendVersion(PROTOCOL_VERSION);
 186     peerLogic->InitializeNode(&dummyNode1);
 187     dummyNode1.nVersion = 1;
 188     dummyNode1.fSuccessfullyConnected = true;
 189     {
 190         LOCK(cs_main);
 191         Misbehaving(dummyNode1.GetId(), 100); // Should get banned
 192     }
 193     LOCK(dummyNode1.cs_sendProcessing);
 194     peerLogic->SendMessages(&dummyNode1, interruptDummy);
 195     BOOST_CHECK(connman->IsBanned(addr1));
 196     BOOST_CHECK(!connman->IsBanned(ip(0xa0b0c001|0x0000ff00))); // Different IP, not banned
 197
 198     CAddress addr2(ip(0xa0b0c002), NODE_NONE);
 199     CNode dummyNode2(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr2, 1, 1, CAddress(), "", true);
 200     dummyNode2.SetSendVersion(PROTOCOL_VERSION);
 201     peerLogic->InitializeNode(&dummyNode2);
 202     dummyNode2.nVersion = 1;
 203     dummyNode2.fSuccessfullyConnected = true;
 204     {
 205         LOCK(cs_main);
 206         Misbehaving(dummyNode2.GetId(), 50);
 207     }
 208     LOCK(dummyNode2.cs_sendProcessing);
 209     peerLogic->SendMessages(&dummyNode2, interruptDummy);
 210     BOOST_CHECK(!connman->IsBanned(addr2)); // 2 not banned yet...
 211     BOOST_CHECK(connman->IsBanned(addr1));  // ... but 1 still should be
 212     {
 213         LOCK(cs_main);
 214         Misbehaving(dummyNode2.GetId(), 50);
 215     }
 216     peerLogic->SendMessages(&dummyNode2, interruptDummy);
 217     BOOST_CHECK(connman->IsBanned(addr2));
 218
 219     bool dummy;
 220     peerLogic->FinalizeNode(dummyNode1.GetId(), dummy);
 221     peerLogic->FinalizeNode(dummyNode2.GetId(), dummy);
 222 }
 223
 224 BOOST_AUTO_TEST_CASE(DoS_banscore)
 225 {
 226     std::atomic<bool> interruptDummy(false);
 227
 228     connman->ClearBanned();
 229     gArgs.ForceSetArg("-banscore", "111"); // because 11 is my favorite number
 230     CAddress addr1(ip(0xa0b0c001), NODE_NONE);
 231     CNode dummyNode1(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr1, 3, 1, CAddress(), "", true);
 232     dummyNode1.SetSendVersion(PROTOCOL_VERSION);
 233     peerLogic->InitializeNode(&dummyNode1);
 234     dummyNode1.nVersion = 1;
 235     dummyNode1.fSuccessfullyConnected = true;
 236     {
 237         LOCK(cs_main);
 238         Misbehaving(dummyNode1.GetId(), 100);
 239     }
 240     LOCK(dummyNode1.cs_sendProcessing);
 241     peerLogic->SendMessages(&dummyNode1, interruptDummy);
 242     BOOST_CHECK(!connman->IsBanned(addr1));
 243     {
 244         LOCK(cs_main);
 245         Misbehaving(dummyNode1.GetId(), 10);
 246     }
 247     peerLogic->SendMessages(&dummyNode1, interruptDummy);
 248     BOOST_CHECK(!connman->IsBanned(addr1));
 249     {
 250         LOCK(cs_main);
 251         Misbehaving(dummyNode1.GetId(), 1);
 252     }
 253     peerLogic->SendMessages(&dummyNode1, interruptDummy);
 254     BOOST_CHECK(connman->IsBanned(addr1));
 255     gArgs.ForceSetArg("-banscore", std::to_string(DEFAULT_BANSCORE_THRESHOLD));
 256
 257     bool dummy;
 258     peerLogic->FinalizeNode(dummyNode1.GetId(), dummy);
 259 }
 260
 261 BOOST_AUTO_TEST_CASE(DoS_bantime)
 262 {
 263     std::atomic<bool> interruptDummy(false);
 264
 265     connman->ClearBanned();
 266     int64_t nStartTime = GetTime();
 267     SetMockTime(nStartTime); // Overrides future calls to GetTime()
 268
 269     CAddress addr(ip(0xa0b0c001), NODE_NONE);
 270     CNode dummyNode(id++, NODE_NETWORK, 0, INVALID_SOCKET, addr, 4, 4, CAddress(), "", true);
 271     dummyNode.SetSendVersion(PROTOCOL_VERSION);
 272     peerLogic->InitializeNode(&dummyNode);
 273     dummyNode.nVersion = 1;
 274     dummyNode.fSuccessfullyConnected = true;
 275
 276     {
 277         LOCK(cs_main);
 278         Misbehaving(dummyNode.GetId(), 100);
 279     }
 280     LOCK(dummyNode.cs_sendProcessing);
 281     peerLogic->SendMessages(&dummyNode, interruptDummy);
 282     BOOST_CHECK(connman->IsBanned(addr));
 283
 284     SetMockTime(nStartTime+60*60);
 285     BOOST_CHECK(connman->IsBanned(addr));
 286
 287     SetMockTime(nStartTime+60*60*24+1);
 288     BOOST_CHECK(!connman->IsBanned(addr));
 289
 290     bool dummy;
 291     peerLogic->FinalizeNode(dummyNode.GetId(), dummy);
 292 }
 293
 294 CTransactionRef RandomOrphan()
 295 {
 296     std::map<uint256, COrphanTx>::iterator it;
 297     LOCK(cs_main);
 298     it = mapOrphanTransactions.lower_bound(InsecureRand256());
 299     if (it == mapOrphanTransactions.end())
 300         it = mapOrphanTransactions.begin();
 301     return it->second.tx;
 302 }
 303
 304 BOOST_AUTO_TEST_CASE(DoS_mapOrphans)
 305 {
 306     CKey key;
 307     key.MakeNewKey(true);
 308     CBasicKeyStore keystore;
 309     keystore.AddKey(key);
 310
 311     // 50 orphan transactions:
 312     for (int i = 0; i < 50; i++)
 313     {
 314         CMutableTransaction tx;
 315         tx.vin.resize(1);
 316         tx.vin[0].prevout.n = 0;
 317         tx.vin[0].prevout.hash = InsecureRand256();
 318         tx.vin[0].scriptSig << OP_1;
 319         tx.vout.resize(1);
 320         tx.vout[0].nValue = 1*CENT;
 321         tx.vout[0].scriptPubKey = GetScriptForDestination(key.GetPubKey().GetID());
 322
 323         AddOrphanTx(MakeTransactionRef(tx), i);
 324     }
 325
 326     // ... and 50 that depend on other orphans:
 327     for (int i = 0; i < 50; i++)
 328     {
 329         CTransactionRef txPrev = RandomOrphan();
 330
 331         CMutableTransaction tx;
 332         tx.vin.resize(1);
 333         tx.vin[0].prevout.n = 0;
 334         tx.vin[0].prevout.hash = txPrev->GetHash();
 335         tx.vout.resize(1);
 336         tx.vout[0].nValue = 1*CENT;
 337         tx.vout[0].scriptPubKey = GetScriptForDestination(key.GetPubKey().GetID());
 338         SignSignature(keystore, *txPrev, tx, 0, SIGHASH_ALL);
 339
 340         AddOrphanTx(MakeTransactionRef(tx), i);
 341     }
 342
 343     // This really-big orphan should be ignored:
 344     for (int i = 0; i < 10; i++)
 345     {
 346         CTransactionRef txPrev = RandomOrphan();
 347
 348         CMutableTransaction tx;
 349         tx.vout.resize(1);
 350         tx.vout[0].nValue = 1*CENT;
 351         tx.vout[0].scriptPubKey = GetScriptForDestination(key.GetPubKey().GetID());
 352         tx.vin.resize(2777);
 353         for (unsigned int j = 0; j < tx.vin.size(); j++)
 354         {
 355             tx.vin[j].prevout.n = j;
 356             tx.vin[j].prevout.hash = txPrev->GetHash();
 357         }
 358         SignSignature(keystore, *txPrev, tx, 0, SIGHASH_ALL);
 359         // Re-use same signature for other inputs
 360         // (they don't have to be valid for this test)
 361         for (unsigned int j = 1; j < tx.vin.size(); j++)
 362             tx.vin[j].scriptSig = tx.vin[0].scriptSig;
 363
 364         BOOST_CHECK(!AddOrphanTx(MakeTransactionRef(tx), i));
 365     }
 366
 367     LOCK(cs_main);
 368     // Test EraseOrphansFor:
 369     for (NodeId i = 0; i < 3; i++)
 370     {
 371         size_t sizeBefore = mapOrphanTransactions.size();
 372         EraseOrphansFor(i);
 373         BOOST_CHECK(mapOrphanTransactions.size() < sizeBefore);
 374     }
 375
 376     // Test LimitOrphanTxSize() function:
 377     LimitOrphanTxSize(40);
 378     BOOST_CHECK(mapOrphanTransactions.size() <= 40);
 379     LimitOrphanTxSize(10);
 380     BOOST_CHECK(mapOrphanTransactions.size() <= 10);
 381     LimitOrphanTxSize(0);
 382     BOOST_CHECK(mapOrphanTransactions.empty());
 383 }
 384
 385 BOOST_AUTO_TEST_SUITE_END()