Finally moving Sequence code into protocol package

Message Encoding.go

@@ -48,8 +48,8 @@ const (
 // MessageRaw is a high-level message between peers that has not been decoded
 type MessageRaw struct {
 	protocol.PacketRaw
-	SenderPublicKey *btcec.PublicKey // Sender Public Key, ECDSA (secp256k1) 257-bit
-	SequenceInfo    *SequenceExpiry  // Sequence
+	SenderPublicKey *btcec.PublicKey         // Sender Public Key, ECDSA (secp256k1) 257-bit
+	SequenceInfo    *protocol.SequenceExpiry // Sequence
 }
 
 // MessageAnnouncement is the decoded announcement message.

Network.go

@@ -186,12 +186,14 @@ func (nets *Networks) packetWorker() {
 		case protocol.CommandResponse: // Response
 			if response, _ := msgDecodeResponse(raw); response != nil {
 				// Validate sequence number which prevents unsolicited responses.
-				if valid, rtt := nets.Sequences.ValidateSequence(raw, response.Actions&(1<<ActionSequenceLast) > 0); !valid {
+				sequenceInfo, valid, rtt := nets.Sequences.ValidateSequence(raw.SenderPublicKey, raw.Sequence, response.Actions&(1<<ActionSequenceLast) > 0, true)
+				if !valid {
 					//Filters.LogError("packetWorker", "message with invalid sequence %d command %d from %s\n", raw.Sequence, raw.Command, raw.connection.Address.String()) // Only log for debug purposes.
 					continue
 				} else if rtt > 0 {
 					connection.RoundTripTime = rtt
 				}
+				raw.SequenceInfo = sequenceInfo
 
 				// Update known internal/external port and User Agent
 				connection.PortInternal = response.PortInternal
@@ -228,12 +230,14 @@ func (nets *Networks) packetWorker() {
 
 		case protocol.CommandPong: // Ping
 			// Validate sequence number which prevents unsolicited responses.
-			if valid, rtt := nets.Sequences.ValidateSequence(raw, true); !valid {
+			sequenceInfo, valid, rtt := nets.Sequences.ValidateSequence(raw.SenderPublicKey, raw.Sequence, true, false)
+			if !valid {
 				//Filters.LogError("packetWorker", "message with invalid sequence %d command %d from %s\n", raw.Sequence, raw.Command, raw.connection.Address.String()) // Only log for debug purposes.
 				continue
 			} else if rtt > 0 {
 				connection.RoundTripTime = rtt
 			}
+			raw.SequenceInfo = sequenceInfo
 
 			Filters.MessageIn(peer, raw, nil)
 

Networks.go

@@ -6,7 +6,11 @@ Author:     Peter Kleissner
 
 package core
 
-import "sync"
+import (
+	"sync"
+
+	"github.com/PeernetOfficial/core/protocol"
+)
 
 // Networks is the collection of all connected networks
 type Networks struct {
@@ -24,7 +28,7 @@ type Networks struct {
 	rawPacketsIncoming chan networkWire
 
 	// Sequences keeps track of all message sequence number, regardless of the network connection.
-	Sequences *SequenceManager
+	Sequences *protocol.SequenceManager
 
 	// ipListen keeps a simple list of IPs listened to. This allows quickly identifying if an IP matches with a listened one.
 	ipListen *ipList
@@ -40,7 +44,7 @@ func initMessageSequence() {
 
 	networks.rawPacketsIncoming = make(chan networkWire, 1000) // buffer up to 1000 UDP packets before they get buffered by the OS network stack and eventually dropped
 
-	networks.Sequences = NewSequenceManager(ReplyTimeout)
+	networks.Sequences = protocol.NewSequenceManager(ReplyTimeout)
 
 	networks.ipListen = NewIPList()
 }

protocol/Sequence.go

@@ -1,9 +1,10 @@
 /*
-File Name:  Message Sequence.go
+File Name:  Sequence.go
 Copyright:  2021 Peernet s.r.o.
 Author:     Peter Kleissner
 
-Records and verifies message sequences. Sequence numbers are valid on a peer level, independent of which network connection was used.
+This code caches and verifies message sequences. Sequence numbers are valid on a peer level, independent of which network connection was used.
+They can be used to map incoming response messages to previous outgoing requests. The remote peer ID is used together with a consecutive sequence number as unique key.
 
 Advantages:
 * This secures against replay and poisoning attacks.
@@ -12,7 +13,7 @@ Advantages:
 * (future) It can be used to detect missed and lost replies.
 */
 
-package core
+package protocol
 
 import (
 	"math/rand"
@@ -21,7 +22,6 @@ import (
 	"sync/atomic"
 	"time"
 
-	"github.com/PeernetOfficial/core/protocol"
 	"github.com/btcsuite/btcd/btcec"
 )
 
@@ -111,13 +111,8 @@ func (manager *SequenceManager) ArbitrarySequence(publicKey *btcec.PublicKey, da
 }
 
 // ValidateSequence validates the sequence number of an incoming message. It will set raw.sequence if valid.
-func (manager *SequenceManager) ValidateSequence(raw *MessageRaw, invalidate bool) (valid bool, rtt time.Duration) {
-	// Only Response and Pong
-	if raw.Command != protocol.CommandResponse && raw.Command != protocol.CommandPong {
-		return true, rtt
-	}
-
-	key := string(raw.SenderPublicKey.SerializeCompressed()) + strconv.FormatUint(uint64(raw.Sequence), 10)
+func (manager *SequenceManager) ValidateSequence(publicKey *btcec.PublicKey, sequenceNumber uint32, invalidate, extendValidity bool) (sequenceInfo *SequenceExpiry, valid bool, rtt time.Duration) {
+	key := string(publicKey.SerializeCompressed()) + strconv.FormatUint(uint64(sequenceNumber), 10)
 
 	manager.Lock()
 	defer manager.Unlock()
@@ -125,7 +120,7 @@ func (manager *SequenceManager) ValidateSequence(raw *MessageRaw, invalidate boo
 	// lookup the sequence
 	sequence, ok := manager.sequences[key]
 	if !ok {
-		return false, rtt
+		return nil, false, rtt
 	}
 
 	// Initial reply: Store latest roundtrip time. That value might be distorted on Response vs Pong since Response messages might send data
@@ -139,24 +134,17 @@ func (manager *SequenceManager) ValidateSequence(raw *MessageRaw, invalidate boo
 	// invalidate the sequence immediately?
 	if invalidate {
 		delete(manager.sequences, key)
-	} else if raw.Command == protocol.CommandResponse {
-		// Special case CommandResponse: Extend validity in case there are follow-up responses by half of the round-trip time since they will be sent one-way.
+	} else if extendValidity {
+		// Special case CommandResponse: Extend validity in case there are follow-up responses, by half of the round-trip time since they will be sent one-way.
 		sequence.expires = time.Now().Add(time.Duration(manager.ReplyTimeout) * time.Second / 2)
 	}
 
-	raw.SequenceInfo = sequence
-
-	return sequence.expires.After(time.Now()), rtt
+	return sequence, sequence.expires.After(time.Now()), rtt
 }
 
 // InvalidateSequence invalidates the sequence number.
-func (manager *SequenceManager) InvalidateSequence(raw *MessageRaw) {
-	// Only Response
-	if raw.Command != protocol.CommandResponse {
-		return
-	}
-
-	key := string(raw.SenderPublicKey.SerializeCompressed()) + strconv.FormatUint(uint64(raw.Sequence), 10)
+func (manager *SequenceManager) InvalidateSequence(publicKey *btcec.PublicKey, sequenceNumber uint32) {
+	key := string(publicKey.SerializeCompressed()) + strconv.FormatUint(uint64(sequenceNumber), 10)
 
 	manager.Lock()
 	delete(manager.sequences, key)