Merge #19776: net, rpc: expose high bandwidth mode state via getpeerinfo

343dc4760fd2407895fc8b3417a504b194429156 test: add test for high-bandwidth mode states in getpeerinfo (Sebastian Falbesoner)
dab6583307ceb7dd94affcc3482ddcc1a5747147 doc: release note for new getpeerinfo fields "bip152_hb_{from,to}" (Sebastian Falbesoner)
a7ed00f8bbc07dfc09f9e0a5bae10a1afe7612bb rpc: expose high-bandwidth mode states via getpeerinfo (Sebastian Falbesoner)
30bc8fab6833e0447ceadd3fff1566a680e33a98 net: save high-bandwidth mode states in CNodeStats (Sebastian Falbesoner)

Pull request description:

  Fixes #19676, "_For every peer expose through getpeerinfo RPC whether or not we selected them as HB peers, and whether or not they selected us as HB peers._" See [BIP152](https://github.com/bitcoin/bips/blob/master/bip-0152.mediawiki), in particular the [protocol flow diagram](https://github.com/bitcoin/bips/raw/master/bip-0152/protocol-flow.png).  The newly introduced states are changed on the following places in the code:
  * on reception of a `SENDCMPCT` message with valid version, the field `m_highbandwidth_from` is changed depending on the first integer parameter in the message (1=high bandwidth, 0=low bandwidth), i.e. it just mirrors the field `CNodeState.fPreferHeaderAndIDs`.
  * after adding a `SENDCMPCT` message to the send queue, the field `m_highbandwidth_to` is changed depending on how the first integer parameter is set (same as above)

  Note that after receiving `VERACK`, the node also sends `SENDCMPCT`, but that is only to announce the preferred version and never selects high-bandwidth mode, hence there is no need to change the state variables there, which are initialized to `false` anyways.

ACKs for top commit:
  naumenkogs:
    reACK 343dc4760fd2407895fc8b3417a504b194429156
  jonatack:
    re-ACK 343dc4760fd2407895fc8b3417a504b194429156 per `git range-diff 7ea6499 4df1d12 343dc47`

Tree-SHA512: f4999e6a935266812c2259a9b5dc459710037d3c9e938006d282557cc225e56128f72965faffb207fc60c6531fab1206db976dd8729a69e8ca29d4835317b99f

1 files changed, 9 insertions, 1 deletions

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 5dfca4186c..cdddde8540 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -557,11 +557,15 @@ static void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid, CConnman& connma
                 // blocks using compact encodings.
                 connman.ForNode(lNodesAnnouncingHeaderAndIDs.front(), [&connman, nCMPCTBLOCKVersion](CNode* pnodeStop){
                     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();
             }
             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;
         });
@@ -2603,8 +2607,12 @@ void PeerManager::ProcessMessage(CNode& pfrom, const std::string& msg_type, CDat
                 State(pfrom.GetId())->fProvidesHeaderAndIDs = true;
                 State(pfrom.GetId())->fWantsCmpctWitness = nCMPCTBLOCKVersion == 2;
             }
-            if (State(pfrom.GetId())->fWantsCmpctWitness == (nCMPCTBLOCKVersion == 2)) // ignore later version announces
+            if (State(pfrom.GetId())->fWantsCmpctWitness == (nCMPCTBLOCKVersion == 2)) { // ignore later version announces
                 State(pfrom.GetId())->fPreferHeaderAndIDs = fAnnounceUsingCMPCTBLOCK;
+                // 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;
+            }
             if (!State(pfrom.GetId())->fSupportsDesiredCmpctVersion) {
                 if (pfrom.GetLocalServices() & NODE_WITNESS)
                     State(pfrom.GetId())->fSupportsDesiredCmpctVersion = (nCMPCTBLOCKVersion == 2);