[net processing] Add m_our_services and m_their_services to Peer

Track services offered by us and the peer in the Peer object.

1 files changed, 31 insertions, 8 deletions

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index c33dd29923..7c403d73db 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -207,6 +207,27 @@ struct Peer {
     /** Same id as the CNode object for this peer */
     const NodeId m_id{0};
 
+    /** Services we offered to this peer.
+     *
+     *  This is supplied by CConnman during peer initialization. It's const
+     *  because there is no protocol defined for renegotiating services
+     *  initially offered to a peer. The set of local services we offer should
+     *  not change after initialization.
+     *
+     *  An interesting example of this is NODE_NETWORK and initial block
+     *  download: a node which starts up from scratch doesn't have any blocks
+     *  to serve, but still advertises NODE_NETWORK because it will eventually
+     *  fulfill this role after IBD completes. P2P code is written in such a
+     *  way that it can gracefully handle peers who don't make good on their
+     *  service advertisements.
+     *
+     *  TODO: remove redundant CNode::nLocalServices*/
+    const ServiceFlags m_our_services;
+    /** Services this peer offered to us.
+     *
+     * TODO: remove redundant CNode::nServices */
+    std::atomic<ServiceFlags> m_their_services{NODE_NONE};
+
     /** Protects misbehavior data members */
     Mutex m_misbehavior_mutex;
     /** Accumulated misbehavior score for this peer */
@@ -360,8 +381,9 @@ struct Peer {
     /** Time of the last getheaders message to this peer */
     std::atomic<NodeClock::time_point> m_last_getheaders_timestamp{NodeSeconds{}};
 
-    Peer(NodeId id)
+    explicit Peer(NodeId id, ServiceFlags our_services)
         : m_id{id}
+        , m_our_services{our_services}
     {}
 
 private:
@@ -482,7 +504,7 @@ public:
         EXCLUSIVE_LOCKS_REQUIRED(!m_most_recent_block_mutex);
 
     /** Implement NetEventsInterface */
-    void InitializeNode(CNode* pnode) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
+    void InitializeNode(CNode& node, ServiceFlags our_services) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
     void FinalizeNode(const CNode& node) override EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex);
     bool ProcessMessages(CNode* pfrom, std::atomic<bool>& interrupt) override
         EXCLUSIVE_LOCKS_REQUIRED(!m_peer_mutex, !m_recent_confirmed_transactions_mutex, !m_most_recent_block_mutex);
@@ -1299,21 +1321,21 @@ void PeerManagerImpl::UpdateLastBlockAnnounceTime(NodeId node, int64_t time_in_s
     if (state) state->m_last_block_announcement = time_in_seconds;
 }
 
-void PeerManagerImpl::InitializeNode(CNode *pnode)
+void PeerManagerImpl::InitializeNode(CNode& node, ServiceFlags our_services)
 {
-    NodeId nodeid = pnode->GetId();
+    NodeId nodeid = node.GetId();
     {
         LOCK(cs_main);
-        m_node_states.emplace_hint(m_node_states.end(), std::piecewise_construct, std::forward_as_tuple(nodeid), std::forward_as_tuple(pnode->IsInboundConn()));
+        m_node_states.emplace_hint(m_node_states.end(), std::piecewise_construct, std::forward_as_tuple(nodeid), std::forward_as_tuple(node.IsInboundConn()));
         assert(m_txrequest.Count(nodeid) == 0);
     }
-    PeerRef peer = std::make_shared<Peer>(nodeid);
+    PeerRef peer = std::make_shared<Peer>(nodeid, our_services);
     {
         LOCK(m_peer_mutex);
         m_peer_map.emplace_hint(m_peer_map.end(), nodeid, peer);
     }
-    if (!pnode->IsInboundConn()) {
-        PushNodeVersion(*pnode, *peer);
+    if (!node.IsInboundConn()) {
+        PushNodeVersion(node, *peer);
     }
 }
 
@@ -2843,6 +2865,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
         m_connman.PushMessage(&pfrom, msg_maker.Make(NetMsgType::VERACK));
 
         pfrom.nServices = nServices;
+        peer->m_their_services = nServices;
         pfrom.SetAddrLocal(addrMe);
         {
             LOCK(pfrom.m_subver_mutex);