[net processing] Only advertise support for version 2 compact blocks

Subsequent commits will remove support.

Author: jnewbery

src/net_processing.cpp

@@ -175,6 +175,8 @@ static constexpr double MAX_ADDR_RATE_PER_SECOND{0.1};
  *  based increments won't go above this, but the MAX_ADDR_TO_SEND increment following GETADDR
  *  is exempt from this limit). */
 static constexpr size_t MAX_ADDR_PROCESSING_TOKEN_BUCKET{MAX_ADDR_TO_SEND};
+/** The compactblocks version we support. See BIP 152. */
+static constexpr uint64_t CMPCTBLOCKS_VERSION{2};
 
 // Internal stuff
 namespace {
@@ -1003,19 +1005,18 @@ void PeerManagerImpl::MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid)
         }
         m_connman.ForNode(nodeid, [this](CNode* pfrom) EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
             AssertLockHeld(::cs_main);
-            uint64_t nCMPCTBLOCKVersion = 2;
             if (lNodesAnnouncingHeaderAndIDs.size() >= 3) {
                 // As per BIP152, we only get 3 of our peers to announce
                 // 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));
+                m_connman.ForNode(lNodesAnnouncingHeaderAndIDs.front(), [this](CNode* pnodeStop){
+                    m_connman.PushMessage(pnodeStop, CNetMsgMaker(pnodeStop->GetCommonVersion()).Make(NetMsgType::SENDCMPCT, /*high_bandwidth=*/false, /*version=*/CMPCTBLOCKS_VERSION));
                     // 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));
+            m_connman.PushMessage(pfrom, CNetMsgMaker(pfrom->GetCommonVersion()).Make(NetMsgType::SENDCMPCT, /*high_bandwidth=*/true, /*version=*/CMPCTBLOCKS_VERSION));
             // save BIP152 bandwidth state: we select peer to be high-bandwidth
             pfrom->m_bip152_highbandwidth_to = true;
             lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId());
@@ -2861,16 +2862,12 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
             m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::SENDHEADERS));
         }
         if (pfrom.GetCommonVersion() >= SHORT_IDS_BLOCKS_VERSION) {
-            // Tell our peer we are willing to provide version 1 or 2 cmpctblocks
+            // Tell our peer we are willing to provide version 2 cmpctblocks.
             // However, we do not request new block announcements using
             // cmpctblock messages.
             // We send this to non-NODE NETWORK peers as well, because
             // they may wish to request compact blocks from us
-            bool fAnnounceUsingCMPCTBLOCK = false;
-            uint64_t nCMPCTBLOCKVersion = 2;
-            m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion));
-            nCMPCTBLOCKVersion = 1;
-            m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion));
+            m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, /*high_bandwidth=*/false, /*version=*/CMPCTBLOCKS_VERSION));
         }
         pfrom.fSuccessfullyConnected = true;
         return;

test/functional/p2p_compactblocks.py

@@ -192,10 +192,8 @@ def received_sendcmpct():
             return (len(test_node.last_sendcmpct) > 0)
         test_node.wait_until(received_sendcmpct, timeout=30)
         with p2p_lock:
-            # Check that the first version received is version 2
+            # Check that version 2 is received.
             assert_equal(test_node.last_sendcmpct[0].version, 2)
-            # And that we receive versions down to 1.
-            assert_equal(test_node.last_sendcmpct[-1].version, 1)
             test_node.last_sendcmpct = []
 
         tip = int(node.getbestblockhash(), 16)

test/functional/p2p_compactblocks_blocksonly.py

@@ -48,7 +48,7 @@ def run_test(self):
         p2p_conn_high_bw = self.nodes[1].add_p2p_connection(P2PInterface())
         p2p_conn_low_bw = self.nodes[3].add_p2p_connection(P2PInterface())
         for conn in [p2p_conn_blocksonly, p2p_conn_high_bw, p2p_conn_low_bw]:
-            assert_equal(conn.message_count['sendcmpct'], 2)
+            assert_equal(conn.message_count['sendcmpct'], 1)
             conn.send_and_ping(msg_sendcmpct(announce=False, version=2))
 
         # Nodes:
@@ -74,14 +74,14 @@ def run_test(self):
         # receiving a new valid block at the tip.
         p2p_conn_blocksonly.send_and_ping(msg_block(block0))
         assert_equal(int(self.nodes[0].getbestblockhash(), 16), block0.sha256)
-        assert_equal(p2p_conn_blocksonly.message_count['sendcmpct'], 2)
+        assert_equal(p2p_conn_blocksonly.message_count['sendcmpct'], 1)
         assert_equal(p2p_conn_blocksonly.last_message['sendcmpct'].announce, False)
 
         # A normal node participating in transaction relay should request BIP152
         # high bandwidth mode upon receiving a new valid block at the tip.
         p2p_conn_high_bw.send_and_ping(msg_block(block0))
         assert_equal(int(self.nodes[1].getbestblockhash(), 16), block0.sha256)
-        p2p_conn_high_bw.wait_until(lambda: p2p_conn_high_bw.message_count['sendcmpct'] == 3)
+        p2p_conn_high_bw.wait_until(lambda: p2p_conn_high_bw.message_count['sendcmpct'] == 2)
         assert_equal(p2p_conn_high_bw.last_message['sendcmpct'].announce, True)
 
         # Don't send a block from the p2p_conn_low_bw so the low bandwidth node