merge bitcoin#19776: expose high bandwidth mode state via getpeerinfo

doc/release-notes-19776.md

@@ -0,0 +1,9 @@
+Updated RPCs
+------------
+
+- The `getpeerinfo` RPC returns two new boolean fields, `bip152_hb_to` and
+  `bip152_hb_from`, that respectively indicate whether we selected a peer to be
+  in compact blocks high-bandwidth mode or whether a peer selected us as a
+  compact blocks high-bandwidth peer. High-bandwidth peers send new block
+  announcements via a `cmpctblock` message rather than the usual inv/headers
+  announcements. See BIP 152 for more details.

src/net.cpp

@@ -706,6 +706,8 @@ void CNode::CopyStats(CNodeStats& stats)
     }
     stats.fInbound = IsInboundConn();
     stats.m_manual_connection = IsManualConn();
+    X(m_bip152_highbandwidth_to);
+    X(m_bip152_highbandwidth_from);
     {
         LOCK(cs_vSend);
         X(mapSendBytesPerMsgCmd);

src/net.h

@@ -284,6 +284,8 @@ public:
     std::string cleanSubVer;
     bool fInbound;
     bool m_manual_connection;
+    bool m_bip152_highbandwidth_to;
+    bool m_bip152_highbandwidth_from;
     int m_starting_height;
     uint64_t nSendBytes;
     mapMsgCmdSize mapSendBytesPerMsgCmd;
@@ -582,6 +584,11 @@ public:
     }
 
 public:
+    // We selected peer as (compact blocks) high-bandwidth peer (BIP152)
+    std::atomic<bool> m_bip152_highbandwidth_to{false};
+    // Peer selected us as (compact blocks) high-bandwidth peer (BIP152)
+    std::atomic<bool> m_bip152_highbandwidth_from{false};
+
     /** Whether we should relay transactions to this peer (their version
      *  message did not include fRelay=false and this is not a block-relay-only
      *  connection). This only changes from false to true. It will never change

src/net_processing.cpp

@@ -1073,11 +1073,15 @@ void PeerManagerImpl::MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid)
                 // blocks using compact encodings.
                 m_connman.ForNode(lNodesAnnouncingHeaderAndIDs.front(), [this, nCMPCTBLOCKVersion](CNode* pnodeStop){
                     m_connman.PushMessage(pnodeStop, CNetMsgMaker(pnodeStop->GetCommonVersion()).Make(NetMsgType::SENDCMPCT, /*fAnnounceUsingCMPCTBLOCK=*/false, nCMPCTBLOCKVersion));
+                    // save BIP152 bandwidth state: we select peer to be low-bandwidth
+                    pnodeStop->m_bip152_highbandwidth_to = false;
                     return true;
                 });
                 lNodesAnnouncingHeaderAndIDs.pop_front();
             }
             m_connman.PushMessage(pfrom, CNetMsgMaker(pfrom->GetCommonVersion()).Make(NetMsgType::SENDCMPCT, /*fAnnounceUsingCMPCTBLOCK=*/true, nCMPCTBLOCKVersion));
+            // save BIP152 bandwidth state: we select peer to be high-bandwidth
+            pfrom->m_bip152_highbandwidth_to = true;
             lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId());
             return true;
         });
@@ -3687,6 +3691,9 @@ void PeerManagerImpl::ProcessMessage(
             State(pfrom.GetId())->fProvidesHeaderAndIDs = true;
             State(pfrom.GetId())->fPreferHeaderAndIDs = fAnnounceUsingCMPCTBLOCK;
             State(pfrom.GetId())->fSupportsDesiredCmpctVersion = true;
+            // save whether peer selects us as BIP152 high-bandwidth peer
+            // (receiving sendcmpct(1) signals high-bandwidth, sendcmpct(0) low-bandwidth)
+            pfrom.m_bip152_highbandwidth_from = fAnnounceUsingCMPCTBLOCK;
         }
         return;
     }

src/rpc/net.cpp

@@ -145,6 +145,8 @@ static RPCHelpMan getpeerinfo()
                     {RPCResult::Type::NUM, "version", "The peer version, such as 70001"},
                     {RPCResult::Type::STR, "subver", "The string version"},
                     {RPCResult::Type::BOOL, "inbound", "Inbound (true) or Outbound (false)"},
+                    {RPCResult::Type::BOOL, "bip152_hb_to", "Whether we selected peer as (compact blocks) high-bandwidth peer"},
+                    {RPCResult::Type::BOOL, "bip152_hb_from", "Whether peer selected us as (compact blocks) high-bandwidth peer"},
                     {RPCResult::Type::BOOL, "addnode", "Whether connection was due to addnode/-connect or if it was an automatic/inbound connection\n"
                                                        "(DEPRECATED, returned only if the config option -deprecatedrpc=getpeerinfo_addnode is passed)"},
                     {RPCResult::Type::BOOL, "masternode", "Whether connection was due to masternode connection attempt"},
@@ -244,6 +246,8 @@ static RPCHelpMan getpeerinfo()
         // their ver message.
         obj.pushKV("subver", stats.cleanSubVer);
         obj.pushKV("inbound", stats.fInbound);
+        obj.pushKV("bip152_hb_to", stats.m_bip152_highbandwidth_to);
+        obj.pushKV("bip152_hb_from", stats.m_bip152_highbandwidth_from);
         if (IsDeprecatedRPCEnabled("getpeerinfo_addnode")) {
             // addnode is deprecated in v21 for removal in v22
             obj.pushKV("addnode", stats.m_manual_connection);

test/functional/p2p_compactblocks.py

@@ -767,6 +767,34 @@ class CompactBlocksTest(BitcoinTestFramework):
         stalling_peer.send_and_ping(msg)
         assert_equal(int(node.getbestblockhash(), 16), block.sha256)
 
+    def test_highbandwidth_mode_states_via_getpeerinfo(self):
+        # create new p2p connection for a fresh state w/o any prior sendcmpct messages sent
+        hb_test_node = self.nodes[0].add_p2p_connection(TestP2PConn(cmpct_version=1))
+
+        # assert the RPC getpeerinfo boolean fields `bip152_hb_{to, from}`
+        # match the given parameters for the last peer of a given node
+        def assert_highbandwidth_states(node, hb_to, hb_from):
+            peerinfo = node.getpeerinfo()[-1]
+            assert_equal(peerinfo['bip152_hb_to'], hb_to)
+            assert_equal(peerinfo['bip152_hb_from'], hb_from)
+
+        # initially, neither node has selected the other peer as high-bandwidth yet
+        assert_highbandwidth_states(self.nodes[0], hb_to=False, hb_from=False)
+
+        # peer requests high-bandwidth mode by sending sendcmpct(1)
+        hb_test_node.send_and_ping(msg_sendcmpct(announce=True, version=1))
+        assert_highbandwidth_states(self.nodes[0], hb_to=False, hb_from=True)
+
+        # peer generates a block and sends it to node, which should
+        # select the peer as high-bandwidth (up to 3 peers according to BIP 152)
+        block = self.build_block_on_tip(self.nodes[0])
+        hb_test_node.send_and_ping(msg_block(block))
+        assert_highbandwidth_states(self.nodes[0], hb_to=True, hb_from=True)
+
+        # peer requests low-bandwidth mode by sending sendcmpct(0)
+        hb_test_node.send_and_ping(msg_sendcmpct(announce=False, version=1))
+        assert_highbandwidth_states(self.nodes[0], hb_to=True, hb_from=False)
+
     def run_test(self):
         # Get the nodes out of IBD
         self.nodes[0].generate(1)
@@ -817,5 +845,8 @@ class CompactBlocksTest(BitcoinTestFramework):
         self.log.info("Testing invalid index in cmpctblock message...")
         self.test_invalid_cmpctblock_message()
 
+        self.log.info("Testing high-bandwidth mode states via getpeerinfo...")
+        self.test_highbandwidth_mode_states_via_getpeerinfo()
+
 if __name__ == '__main__':
     CompactBlocksTest().main()