Add unit test for outbound peer eviction

Github-Pull: bitcoin#11490
Rebased-From: e065249

Author: sdaftuar

src/test/DoS_tests.cpp

@@ -42,6 +42,51 @@ static NodeId id = 0;
 
 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.
+    BOOST_CHECK(chainActive.Tip() != nullptr);
+    BOOST_CHECK(chainActive.Tip()->nChainWork > 0);
+
+    // Test starts here
+    peerLogic->SendMessages(&dummyNode1, interruptDummy); // should result in getheaders
+    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);
+}
+
 BOOST_AUTO_TEST_CASE(DoS_banning)
 {
     std::atomic<bool> interruptDummy(false);
@@ -71,6 +116,10 @@ BOOST_AUTO_TEST_CASE(DoS_banning)
     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)
@@ -95,6 +144,9 @@ BOOST_AUTO_TEST_CASE(DoS_banscore)
     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)
@@ -121,6 +173,9 @@ BOOST_AUTO_TEST_CASE(DoS_bantime)
 
     SetMockTime(nStartTime+60*60*24+1);
     BOOST_CHECK(!connman->IsBanned(addr));
+
+    bool dummy;
+    peerLogic->FinalizeNode(dummyNode.GetId(), dummy);
 }
 
 CTransactionRef RandomOrphan()