eth, p2p: use truncated names (#21698)

* peer: return localAddr instead of name to prevent spam

We currently use the name (which can be freely set by the peer) in several log messages.
This enables malicious actors to write spam into your geth log.
This commit returns the localAddr instead of the freely settable name.

* p2p: reduce usage of peer.Name in warn messages

* eth, p2p: use truncated names

* Update peer.go

Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Felix Lange <fjl@twurst.com>

p2p/peer.go

@@ -138,8 +138,17 @@ func (p *Peer) Node() *enode.Node {
 	return p.rw.node
 }
 
-// Name returns the node name that the remote node advertised.
+// Name returns an abbreviated form of the name
 func (p *Peer) Name() string {
+	s := p.rw.name
+	if len(s) > 20 {
+		return s[:20] + "..."
+	}
+	return s
+}
+
+// Fullname returns the node name that the remote node advertised.
+func (p *Peer) Fullname() string {
 	return p.rw.name
 }
 
@@ -463,7 +472,7 @@ func (p *Peer) Info() *PeerInfo {
 	info := &PeerInfo{
 		Enode:     p.Node().URLv4(),
 		ID:        p.ID().String(),
-		Name:      p.Name(),
+		Name:      p.Fullname(),
 		Caps:      caps,
 		Protocols: make(map[string]interface{}),
 	}

p2p/server.go

@@ -757,7 +757,7 @@ running:
 				// The handshakes are done and it passed all checks.
 				p := srv.launchPeer(c)
 				peers[c.node.ID()] = p
-				srv.log.Debug("Adding p2p peer", "peercount", len(peers), "id", p.ID(), "conn", c.flags, "addr", p.RemoteAddr(), "name", truncateName(c.name))
+				srv.log.Debug("Adding p2p peer", "peercount", len(peers), "id", p.ID(), "conn", c.flags, "addr", p.RemoteAddr(), "name", p.Name())
 				srv.dialsched.peerAdded(c)
 				if p.Inbound() {
 					inboundCount++
@@ -996,13 +996,6 @@ func nodeFromConn(pubkey *ecdsa.PublicKey, conn net.Conn) *enode.Node {
 	return enode.NewV4(pubkey, ip, port, port)
 }
 
-func truncateName(s string) string {
-	if len(s) > 20 {
-		return s[:20] + "..."
-	}
-	return s
-}
-
 // checkpoint sends the conn to run, which performs the
 // post-handshake checks for the stage (posthandshake, addpeer).
 func (srv *Server) checkpoint(c *conn, stage chan<- *conn) error {