Added feeler connections increasing good addrs in the tried table.

Tests if addresses are online or offline by briefly connecting to them. These short lived connections are referred to as feeler connections. Feeler connections are designed to increase the number of fresh online addresses in tried by selecting and connecting to addresses in new. One feeler connection is attempted on average once every two minutes.

This change was suggested as Countermeasure 4 in
Eclipse Attacks on Bitcoin’s Peer-to-Peer Network, Ethan Heilman,
Alison Kendler, Aviv Zohar, Sharon Goldberg. ePrint Archive Report
2015/263. March 2015.

1 files changed, 22 insertions, 0 deletions

diff --git a/src/test/net_tests.cpp b/src/test/net_tests.cpp
index 6511e6ffa..267d1b55e 100644
--- a/src/test/net_tests.cpp
+++ b/src/test/net_tests.cpp
@@ -150,4 +150,26 @@ BOOST_AUTO_TEST_CASE(caddrdb_read_corrupted)
     BOOST_CHECK(addrman2.size() == 0);
 }
 
+BOOST_AUTO_TEST_CASE(cnode_simple_test)
+{
+    SOCKET hSocket = INVALID_SOCKET;
+
+    in_addr ipv4Addr;
+    ipv4Addr.s_addr = 0xa0b0c001;
+    
+    CAddress addr = CAddress(CService(ipv4Addr, 7777), NODE_NETWORK);
+    std::string pszDest = "";
+    bool fInboundIn = false;
+
+    // Test that fFeeler is false by default.
+    CNode* pnode1 = new CNode(hSocket, addr, pszDest, fInboundIn);
+    BOOST_CHECK(pnode1->fInbound == false);
+    BOOST_CHECK(pnode1->fFeeler == false);
+
+    fInboundIn = true;
+    CNode* pnode2 = new CNode(hSocket, addr, pszDest, fInboundIn);
+    BOOST_CHECK(pnode2->fInbound == true);
+    BOOST_CHECK(pnode2->fFeeler == false);
+}
+
 BOOST_AUTO_TEST_SUITE_END()