Merge bitcoin/bitcoin#33448: net/rpc: Report inv information for debugging

2738b63e02 test: validate behaviour of getpeerinfo last_inv_sequence and inv_to_send (Anthony Towns)
77b2ebb811 rpc/net: report per-peer last_inv_sequence (Anthony Towns)
adefb51c54 rpc/net: add per-peer inv_to_send sizes (Anthony Towns)

Pull request description:

  Adds per-peer entries to `getpeerinfo` for the size of the inv_to_send queue and the mempool sequence number as at the last INV. Can be helpful for debugging tx relay performance and privacy/fingerprinting issues.

ACKs for top commit:
  sipa:
    utACK 2738b63e02
  instagibbs:
    ACK 2738b63e02

Tree-SHA512: e3c9c52e8e38b099d405a177ffba6783c5821cc5ce1432b98218843e00906986ce2141dcd5b04a67006c328211a672e519fa3390e012688499bfc9ac99767599

src/net_processing.cpp

@@ -312,7 +312,7 @@ struct Peer {
         std::chrono::microseconds m_next_inv_send_time GUARDED_BY(m_tx_inventory_mutex){0};
         /** The mempool sequence num at which we sent the last `inv` message to this peer.
          *  Can relay txs with lower sequence numbers than this (see CTxMempool::info_for_relay). */
-        uint64_t m_last_inv_sequence GUARDED_BY(NetEventsInterface::g_msgproc_mutex){1};
+        uint64_t m_last_inv_sequence GUARDED_BY(m_tx_inventory_mutex){1};
 
         /** Minimum fee rate with which to filter transaction announcements to this node. See BIP133. */
         std::atomic<CAmount> m_fee_filter_received{0};
@@ -942,7 +942,7 @@ private:
 
     /** Determine whether or not a peer can request a transaction, and return it (or nullptr if not found or not allowed). */
     CTransactionRef FindTxForGetData(const Peer::TxRelay& tx_relay, const GenTxid& gtxid)
-        EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex, NetEventsInterface::g_msgproc_mutex);
+        EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex, !tx_relay.m_tx_inventory_mutex);
 
     void ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic<bool>& interruptMsgProc)
         EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex, peer.m_getdata_requests_mutex, NetEventsInterface::g_msgproc_mutex)
@@ -1728,9 +1728,13 @@ bool PeerManagerImpl::GetNodeStateStats(NodeId nodeid, CNodeStateStats& stats) c
     if (auto tx_relay = peer->GetTxRelay(); tx_relay != nullptr) {
         stats.m_relay_txs = WITH_LOCK(tx_relay->m_bloom_filter_mutex, return tx_relay->m_relay_txs);
         stats.m_fee_filter_received = tx_relay->m_fee_filter_received.load();
+        LOCK(tx_relay->m_tx_inventory_mutex);
+        stats.m_last_inv_seq = tx_relay->m_last_inv_sequence;
+        stats.m_inv_to_send = tx_relay->m_tx_inventory_to_send.size();
     } else {
         stats.m_relay_txs = false;
         stats.m_fee_filter_received = 0;
+        stats.m_inv_to_send = 0;
     }
 
     stats.m_ping_wait = ping_wait;
@@ -2362,8 +2366,8 @@ CTransactionRef PeerManagerImpl::FindTxForGetData(const Peer::TxRelay& tx_relay,
 {
     // If a tx was in the mempool prior to the last INV for this peer, permit the request.
     auto txinfo{std::visit(
-        [&](const auto& id) EXCLUSIVE_LOCKS_REQUIRED(NetEventsInterface::g_msgproc_mutex) {
+        [&](const auto& id) {
-            return m_mempool.info_for_relay(id, tx_relay.m_last_inv_sequence);
+            return m_mempool.info_for_relay(id, WITH_LOCK(tx_relay.m_tx_inventory_mutex, return tx_relay.m_last_inv_sequence));
         },
         gtxid)};
     if (txinfo.tx) {

src/net_processing.h

@@ -54,6 +54,8 @@ struct CNodeStateStats {
     std::chrono::microseconds m_ping_wait;
     std::vector<int> vHeightInFlight;
     bool m_relay_txs;
+    int m_inv_to_send = 0;
+    uint64_t m_last_inv_seq{0};
     CAmount m_fee_filter_received;
     uint64_t m_addr_processed = 0;
     uint64_t m_addr_rate_limited = 0;

src/rpc/net.cpp

@@ -142,6 +142,8 @@ static RPCHelpMan getpeerinfo()
                         {RPCResult::Type::STR, "SERVICE_NAME", "the service name if it is recognised"}
                     }},
                     {RPCResult::Type::BOOL, "relaytxes", "Whether we relay transactions to this peer"},
+                    {RPCResult::Type::NUM, "last_inv_sequence", "Mempool sequence number of this peer's last INV"},
+                    {RPCResult::Type::NUM, "inv_to_send", "How many txs we have queued to announce to this peer"},
                     {RPCResult::Type::NUM_TIME, "lastsend", "The " + UNIX_EPOCH_TIME + " of the last send"},
                     {RPCResult::Type::NUM_TIME, "lastrecv", "The " + UNIX_EPOCH_TIME + " of the last receive"},
                     {RPCResult::Type::NUM_TIME, "last_transaction", "The " + UNIX_EPOCH_TIME + " of the last valid transaction received from this peer"},
@@ -238,6 +240,8 @@ static RPCHelpMan getpeerinfo()
         obj.pushKV("services", strprintf("%016x", services));
         obj.pushKV("servicesnames", GetServicesNames(services));
         obj.pushKV("relaytxes", statestats.m_relay_txs);
+        obj.pushKV("last_inv_sequence", statestats.m_last_inv_seq);
+        obj.pushKV("inv_to_send", statestats.m_inv_to_send);
         obj.pushKV("lastsend", count_seconds(stats.m_last_send));
         obj.pushKV("lastrecv", count_seconds(stats.m_last_recv));
         obj.pushKV("last_transaction", count_seconds(stats.m_last_tx_time));

test/functional/p2p_leak_tx.py

@@ -12,6 +12,7 @@ from test_framework.util import (
 )
 from test_framework.wallet import MiniWallet
 
+import time
 
 class P2PNode(P2PDataStore):
     def on_inv(self, msg):
@@ -36,8 +37,24 @@ class P2PLeakTxTest(BitcoinTestFramework):
 
         self.log.debug("Generate transaction and block")
         inbound_peer.last_message.pop("inv", None)
+
+        self.gen_node.setmocktime(int(time.time())) # pause time based activities
         wtxid = self.miniwallet.send_self_transfer(from_node=self.gen_node)["wtxid"]
+        rawmp = self.gen_node.getrawmempool(False, True)
+        pi = self.gen_node.getpeerinfo()[0]
+        assert_equal(rawmp["mempool_sequence"], 2) # our tx cause mempool activity
+        assert_equal(pi["last_inv_sequence"], 1) # that is after the last inv
+        assert_equal(pi["inv_to_send"], 1) # and our tx has been queued
+        self.gen_node.setmocktime(0)
+
         inbound_peer.wait_until(lambda: "inv" in inbound_peer.last_message and inbound_peer.last_message.get("inv").inv[0].hash == int(wtxid, 16))
+
+        rawmp = self.gen_node.getrawmempool(False, True)
+        pi = self.gen_node.getpeerinfo()[0]
+        assert_equal(rawmp["mempool_sequence"], 2) # no mempool update
+        assert_equal(pi["last_inv_sequence"], 2) # announced the current mempool
+        assert_equal(pi["inv_to_send"], 0) # nothing left in the queue
+
         want_tx = msg_getdata(inv=inbound_peer.last_message.get("inv").inv)
         self.generate(self.gen_node, 1)
 

test/functional/rpc_net.py

@@ -166,6 +166,8 @@ class NetTest(BitcoinTestFramework):
                 "permissions": [],
                 "presynced_headers": -1,
                 "relaytxes": False,
+                "inv_to_send": 0,
+                "last_inv_sequence": 0,
                 "services": "0000000000000000",
                 "servicesnames": [],
                 "session_id": "" if not self.options.v2transport else no_version_peer.v2_state.peer['session_id'].hex(),