status-go/geth-patches/0009-whisper-envelopes-tracing.patch

diff --git a/whisper/whisperv5/doc.go b/whisper/whisperv5/doc.go
index a6c9e610d..eb2b75210 100644
--- a/whisper/whisperv5/doc.go
+++ b/whisper/whisperv5/doc.go
@@ -99,3 +99,40 @@ type NotificationServer interface {
 	// Stop stops notification sending loop, releasing related resources
 	Stop() error
 }
+
+type envelopeSource int
+
+const (
+	_ = iota
+	// peerSource indicates a source as a regular peer.
+	peerSource envelopeSource = iota
+	// p2pSource indicates that envelop was received from a trusted peer.
+	p2pSource
+)
+
+// EnvelopeMeta keeps metadata of received envelopes.
+type EnvelopeMeta struct {
+	Hash   string
+	Topic  TopicType
+	Size   uint32
+	Source envelopeSource
+	IsNew  bool
+	Peer   string
+}
+
+// SourceString converts source to string.
+func (m *EnvelopeMeta) SourceString() string {
+	switch m.Source {
+	case peerSource:
+		return "peer"
+	case p2pSource:
+		return "p2p"
+	default:
+		return "unknown"
+	}
+}
+
+// EnvelopeTracer tracks received envelopes.
+type EnvelopeTracer interface {
+	Trace(*EnvelopeMeta)
+}
diff --git a/whisper/whisperv5/whisper.go b/whisper/whisperv5/whisper.go
index c39e8b3e0..631676328 100644
--- a/whisper/whisperv5/whisper.go
+++ b/whisper/whisperv5/whisper.go
@@ -79,6 +79,7 @@ type Whisper struct {
 
 	mailServer         MailServer // MailServer interface
 	notificationServer NotificationServer
+	envelopeTracer     EnvelopeTracer // Service collecting envelopes metadata
 }
 
 // New creates a Whisper client ready to communicate through the Ethereum P2P network.
@@ -162,6 +163,12 @@ func (w *Whisper) RegisterNotificationServer(server NotificationServer) {
 	w.notificationServer = server
 }
 
+// RegisterEnvelopeTracer registers an EnveloperTracer to collect information
+// about received envelopes.
+func (w *Whisper) RegisterEnvelopeTracer(tracer EnvelopeTracer) {
+	w.envelopeTracer = tracer
+}
+
 // Protocols returns the whisper sub-protocols ran by this particular client.
 func (w *Whisper) Protocols() []p2p.Protocol {
 	return []p2p.Protocol{w.protocol}
@@ -603,6 +610,7 @@ func (wh *Whisper) runMessageLoop(p *Peer, rw p2p.MsgReadWriter) error {
 				log.Warn("failed to decode envelope, peer will be disconnected", "peer", p.peer.ID(), "err", err)
 				return errors.New("invalid envelope")
 			}
+			wh.traceEnvelope(&envelope, !wh.isEnvelopeCached(envelope.Hash()), peerSource, p)
 			cached, err := wh.add(&envelope)
 			if err != nil {
 				log.Warn("bad envelope received, peer will be disconnected", "peer", p.peer.ID(), "err", err)
@@ -623,6 +631,7 @@ func (wh *Whisper) runMessageLoop(p *Peer, rw p2p.MsgReadWriter) error {
 					return errors.New("invalid direct message")
 				}
 				wh.postEvent(&envelope, true)
+				wh.traceEnvelope(&envelope, false, p2pSource, p)
 			}
 		case p2pRequestCode:
 			// Must be processed if mail server is implemented. Otherwise ignore.
@@ -718,6 +727,22 @@ func (wh *Whisper) add(envelope *Envelope) (bool, error) {
 	return true, nil
 }
 
+// traceEnvelope collects basic metadata about an envelope and sender peer.
+func (w *Whisper) traceEnvelope(envelope *Envelope, isNew bool, source envelopeSource, peer *Peer) {
+	if w.envelopeTracer == nil {
+		return
+	}
+
+	w.envelopeTracer.Trace(&EnvelopeMeta{
+		Hash:   envelope.Hash().String(),
+		Topic:  BytesToTopic(envelope.Topic[:]),
+		Size:   uint32(envelope.size()),
+		Source: source,
+		IsNew:  isNew,
+		Peer:   peer.peer.Info().ID,
+	})
+}
+
 // postEvent queues the message for further processing.
 func (w *Whisper) postEvent(envelope *Envelope, isP2P bool) {
 	// if the version of incoming message is higher than