Initial filters for new peers and new connections. More filters to be added. #4

Connection.go

@@ -175,6 +175,10 @@ func (peer *PeerInfo) registerConnection(incoming *Connection) (result *Connecti
 	peer.connectionActive = append(peer.connectionActive, incoming)
 	peer.setConnectionLatest(incoming)
 
+	if Filters.NewPeerConnection != nil {
+		Filters.NewPeerConnection(peer, incoming)
+	}
+
 	return incoming
 }
 

Filter.go

@@ -0,0 +1,21 @@
+/*
+File Name:  Filter.go
+Copyright:  2021 Peernet s.r.o.
+Author:     Peter Kleissner
+
+Filters allow the caller to intercept events to log, modify, or prevent.
+*/
+
+package core
+
+// Filters contains all functions to install the hook. Use nil for unused.
+// The functions are called sequentially and block execution; if the filter takes a long time it should start a Go routine.
+var Filters struct {
+	// NewPeer is called every time a new peer, that is one that is not currently in the peer list.
+	// Note that peers might be removed from peer lists and reappear quickly, i.e. this function may be called multiple times for the same peers.
+	// The filter must maintain its own map of unique peer IDs if actual uniqueness of new peers is desired.
+	NewPeer func(peer *PeerInfo, connection *Connection)
+
+	// NewPeerConnection is called for each new established connection to a peer. Note that connections might be dropped and reconnected at anytime.
+	NewPeerConnection func(peer *PeerInfo, connection *Connection)
+}

Peer ID.go

@@ -145,6 +145,13 @@ func PeerlistAdd(PublicKey *btcec.PublicKey, connections ...*Connection) (peer *
 		}
 	}
 
+	if Filters.NewPeer != nil {
+		Filters.NewPeer(peer, connections[0])
+	}
+	if Filters.NewPeerConnection != nil {
+		Filters.NewPeerConnection(peer, connections[0])
+	}
+
 	return peer, true
 }