Merge bitcoin/bitcoin#23218: p2p: Use mocktime for ping timeout

fadf1186c8 p2p: Use mocktime for ping timeout (MarcoFalke)

Pull request description:

  It is slightly confusing to use mocktime for some times, but not others.

  Start fixing that by making the ping timeout use mocktime.

  The only downside would be that tests that use mocktime disconnect peers after this patch. However, I don't think this is an issue, as the inactivity check is already disabled for all functional tests after commit 6d76b57ca0. Only one unit test needed the inactivity check disabled as part of this patch.

  A nice side effect of this patch is that the `p2p_ping` functional test now runs 4 seconds faster.

ACKs for top commit:
  laanwj:
    Code review ACK fadf1186c8

Tree-SHA512: e9e7b21040a89d9d574b3038f85a67e6336de6cd6e41aa286769cd03cada6e75a94ec01700e052e56d822ef85d7813cc06bf7e67b81543eff8917a16cdccf942

src/net.cpp

@@ -1295,9 +1295,8 @@ void CConnman::NotifyNumConnectionsChanged()
     }
 }
 
-bool CConnman::ShouldRunInactivityChecks(const CNode& node, std::optional<int64_t> now_in) const
+bool CConnman::ShouldRunInactivityChecks(const CNode& node, int64_t now) const
 {
-    const int64_t now = now_in ? now_in.value() : GetTimeSeconds();
     return node.nTimeConnected + m_peer_connect_timeout < now;
 }
 

src/net.h

@@ -942,7 +942,7 @@ public:
     std::chrono::microseconds PoissonNextSendInbound(std::chrono::microseconds now, std::chrono::seconds average_interval);
 
     /** Return true if we should disconnect the peer for failing an inactivity check. */
-    bool ShouldRunInactivityChecks(const CNode& node, std::optional<int64_t> now=std::nullopt) const;
+    bool ShouldRunInactivityChecks(const CNode& node, int64_t secs_now) const;
 
 private:
     struct ListenSocket {

src/net_processing.cpp

@@ -4312,8 +4312,11 @@ void PeerManagerImpl::CheckForStaleTipAndEvictPeers()
 
 void PeerManagerImpl::MaybeSendPing(CNode& node_to, Peer& peer, std::chrono::microseconds now)
 {
-    if (m_connman.ShouldRunInactivityChecks(node_to) && peer.m_ping_nonce_sent &&
+    if (m_connman.ShouldRunInactivityChecks(node_to, std::chrono::duration_cast<std::chrono::seconds>(now).count()) &&
+        peer.m_ping_nonce_sent &&
         now > peer.m_ping_start.load() + std::chrono::seconds{TIMEOUT_INTERVAL}) {
+        // The ping timeout is using mocktime. To disable the check during
+        // testing, increase -peertimeout.
         LogPrint(BCLog::NET, "ping timeout: %fs peer=%d\n", 0.000001 * count_microseconds(now - peer.m_ping_start.load()), peer.m_id);
         node_to.fDisconnect = true;
         return;

src/test/denialofservice_tests.cpp

@@ -52,6 +52,8 @@ BOOST_AUTO_TEST_CASE(outbound_slow_chain_eviction)
 {
     const CChainParams& chainparams = Params();
     auto connman = std::make_unique<CConnman>(0x1337, 0x1337, *m_node.addrman);
+    // Disable inactivity checks for this test to avoid interference
+    static_cast<ConnmanTestMsg*>(connman.get())->SetPeerConnectTimeout(99999);
     auto peerLogic = PeerManager::make(chainparams, *connman, *m_node.addrman, nullptr,
                                        *m_node.chainman, *m_node.mempool, false);
 

src/test/util/net.h

@@ -17,6 +17,12 @@
 
 struct ConnmanTestMsg : public CConnman {
     using CConnman::CConnman;
+
+    void SetPeerConnectTimeout(int64_t timeout)
+    {
+        m_peer_connect_timeout = timeout;
+    }
+
     void AddTestNode(CNode& node)
     {
         LOCK(cs_vNodes);

test/functional/p2p_ping.py

@@ -30,11 +30,16 @@ class NodeNoPong(P2PInterface):
         pass
 
 
+TIMEOUT_INTERVAL = 20 * 60
+
+
 class PingPongTest(BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 1
-        self.extra_args = [['-peertimeout=3']]
+        # Set the peer connection timeout low. It does not matter for this
+        # test, as long as it is less than TIMEOUT_INTERVAL.
+        self.extra_args = [['-peertimeout=1']]
 
     def check_peer_info(self, *, pingtime, minping, pingwait):
         stats = self.nodes[0].getpeerinfo()[0]
@@ -110,8 +115,11 @@ class PingPongTest(BitcoinTestFramework):
         self.nodes[0].ping()
         no_pong_node.wait_until(lambda: 'ping' in no_pong_node.last_message)
         with self.nodes[0].assert_debug_log(['ping timeout: 1201.000000s']):
-            self.mock_forward(20 * 60 + 1)
-            time.sleep(4)  # peertimeout + 1
+            self.mock_forward(TIMEOUT_INTERVAL // 2)
+            # Check that sending a ping does not prevent the disconnect
+            no_pong_node.sync_with_ping()
+            self.mock_forward(TIMEOUT_INTERVAL // 2 + 1)
+            no_pong_node.wait_for_disconnect()
 
 
 if __name__ == '__main__':