feat: add receipt management for packet handling, including registration, unregistration, and proof validation

pkg/transport/transport.go

@@ -114,6 +114,8 @@ type Transport struct {
 	pathfinder       *pathfinder.PathFinder
 	announceHandlers []announce.Handler
 	paths            map[string]*common.Path
+	receipts         []*packet.PacketReceipt
+	receiptsMutex    sync.RWMutex
 }
 
 type Path struct {
@@ -133,6 +135,8 @@ func NewTransport(cfg *common.ReticulumConfig) *Transport {
 		links:         make(map[string]*Link),
 		destinations:  make(map[string]interface{}),
 		pathfinder:    pathfinder.NewPathFinder(),
+		receipts:      make([]*packet.PacketReceipt, 0),
+		receiptsMutex: sync.RWMutex{},
 	}
 	return t
 }
@@ -676,9 +680,15 @@ func (t *Transport) HandlePacket(data []byte, iface common.NetworkInterface) {
 	case PACKET_TYPE_LINK:
 		debug.Log(debug.DEBUG_VERBOSE, "Processing link packet")
 		t.handleLinkPacket(data[1:], iface)
-	case 0x03:
-		debug.Log(debug.DEBUG_VERBOSE, "Processing path response")
-		t.handlePathResponse(data[1:], iface)
+	case packet.PacketTypeProof:
+		debug.Log(debug.DEBUG_VERBOSE, "Processing proof packet")
+		fullData := append([]byte{packet.PacketTypeProof}, data[1:]...)
+		pkt := &packet.Packet{Raw: fullData}
+		if err := pkt.Unpack(); err != nil {
+			debug.Log(debug.DEBUG_INFO, "Failed to unpack proof packet", "error", err)
+			return
+		}
+		t.handleProofPacket(pkt, iface)
 	case 0x00:
 		debug.Log(debug.DEBUG_VERBOSE, "Processing transport packet")
 		t.handleTransportPacket(data[1:], iface)
@@ -1084,6 +1094,15 @@ func (t *Transport) SendPacket(p *packet.Packet) error {
 		return fmt.Errorf("failed to send packet: %w", err)
 	}
 
+	p.Sent = true
+	p.SentAt = time.Now()
+
+	if p.CreateReceipt {
+		receipt := packet.NewPacketReceipt(p)
+		t.RegisterReceipt(receipt)
+		debug.Log(debug.DEBUG_PACKETS, "Created packet receipt")
+	}
+
 	debug.Log(debug.DEBUG_ALL, "Packet sent successfully")
 	return nil
 }
@@ -1356,3 +1375,61 @@ func (t *Transport) GetInterfaces() map[string]common.NetworkInterface {
 func (t *Transport) GetConfig() *common.ReticulumConfig {
 	return t.config
 }
+
+func (t *Transport) RegisterReceipt(receipt *packet.PacketReceipt) {
+	t.receiptsMutex.Lock()
+	defer t.receiptsMutex.Unlock()
+	t.receipts = append(t.receipts, receipt)
+	debug.Log(debug.DEBUG_PACKETS, "Registered packet receipt", "hash", fmt.Sprintf("%x", receipt.GetHash()[:8]))
+}
+
+func (t *Transport) UnregisterReceipt(receipt *packet.PacketReceipt) {
+	t.receiptsMutex.Lock()
+	defer t.receiptsMutex.Unlock()
+	
+	for i, r := range t.receipts {
+		if r == receipt {
+			t.receipts = append(t.receipts[:i], t.receipts[i+1:]...)
+			debug.Log(debug.DEBUG_PACKETS, "Unregistered packet receipt")
+			return
+		}
+	}
+}
+
+func (t *Transport) handleProofPacket(pkt *packet.Packet, iface common.NetworkInterface) {
+	debug.Log(debug.DEBUG_PACKETS, "Processing proof packet", "size", len(pkt.Data))
+	
+	var proofHash []byte
+	if len(pkt.Data) == packet.EXPL_LENGTH {
+		proofHash = pkt.Data[:identity.HASHLENGTH/8]
+		debug.Log(debug.DEBUG_PACKETS, "Explicit proof", "hash", fmt.Sprintf("%x", proofHash[:8]))
+	} else {
+		debug.Log(debug.DEBUG_PACKETS, "Implicit proof")
+	}
+	
+	t.receiptsMutex.RLock()
+	receipts := make([]*packet.PacketReceipt, len(t.receipts))
+	copy(receipts, t.receipts)
+	t.receiptsMutex.RUnlock()
+	
+	for _, receipt := range receipts {
+		receiptValidated := false
+		
+		if proofHash != nil {
+			receiptHash := receipt.GetHash()
+			if string(receiptHash) == string(proofHash) {
+				receiptValidated = receipt.ValidateProofPacket(pkt)
+			}
+		} else {
+			receiptValidated = receipt.ValidateProofPacket(pkt)
+		}
+		
+		if receiptValidated {
+			debug.Log(debug.DEBUG_PACKETS, "Proof validated for receipt")
+			t.UnregisterReceipt(receipt)
+			return
+		}
+	}
+	
+	debug.Log(debug.DEBUG_PACKETS, "No matching receipt for proof")
+}