From f62b294fe84d124577eb604ebff60d81147a3750 Mon Sep 17 00:00:00 2001
From: Joel Wetzell <jwetzell@yahoo.com>
Date: Fri, 6 Dec 2024 21:52:27 -0600
Subject: [PATCH] add basic wrapper and ack data decoding

---
 packages/acn/src/models.ts  | 17 ++++++++++++++++-
 packages/acn/src/pdu/sdt.ts | 29 +++++++++++++++++++++++++++--
 2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/packages/acn/src/models.ts b/packages/acn/src/models.ts
index 5b1e4bf..e1c045a 100644
--- a/packages/acn/src/models.ts
+++ b/packages/acn/src/models.ts
@@ -88,8 +88,23 @@ export type SDTJoinRefuseData = {
   refuseCode: number;
 };
 
+export type SDTWrapperData = {
+  channelNumber: number;
+  totalSequenceNumber: number;
+  reliableSequenceNumber: number;
+  oldestAvailableWrapper: number;
+  firstMemberToAck: number;
+  lastMemberToAck: number;
+  makThreshold: number;
+  sdtClientBlock: Uint8Array;
+};
+
+export type SDTAckData = {
+  reliableSequenceNumber: number;
+};
+
 export type SessionDataTransportPDU = {
   vector: SessionDataTransportVectors;
   // TODO(jwetzell): cleanup these types
-  data: SDTJoinData | SDTJoinAcceptData | SDTJoinRefuseData| Uint8Array;
+  data: SDTJoinData | SDTJoinAcceptData | SDTJoinRefuseData | SDTWrapperData | SDTAckData | Uint8Array;
 };
diff --git a/packages/acn/src/pdu/sdt.ts b/packages/acn/src/pdu/sdt.ts
index 27108a8..b2224b9 100644
--- a/packages/acn/src/pdu/sdt.ts
+++ b/packages/acn/src/pdu/sdt.ts
@@ -1,4 +1,4 @@
-import { SessionDataTransportPDU, SessionDataTransportVectors, TransportLayerAddress } from '../models';
+import { SDTWrapperData, SessionDataTransportPDU, SessionDataTransportVectors, TransportLayerAddress } from '../models';
 import { toHex } from '../utils';
 
 // TODO(jwetzell): work out flag inheritance, will need previous PDU
@@ -25,7 +25,6 @@ export function decode(bytes: Uint8Array): SessionDataTransportPDU {
   const lengthL = view.getUint8(lengthOffset);
 
   let length = (lengthH << 8) + lengthL;
-  console.log('length', length);
   if (lengthFlag) {
     lengthOffset += 1;
     const lengthX = view.getUint8(lengthOffset);
@@ -107,6 +106,32 @@ export function decode(bytes: Uint8Array): SessionDataTransportPDU {
         data: joinData,
       };
     }
+    case SessionDataTransportVectors.REL_WRAP:
+    case SessionDataTransportVectors.UNREL_WRAP: {
+      const wrapperData: SDTWrapperData = {
+        channelNumber: view.getUint16(dataOffset),
+        totalSequenceNumber: view.getUint32(dataOffset + 2),
+        reliableSequenceNumber: view.getUint32(dataOffset + 6),
+        oldestAvailableWrapper: view.getUint32(dataOffset + 10),
+        firstMemberToAck: view.getUint16(dataOffset + 14),
+        lastMemberToAck: view.getUint16(dataOffset + 16),
+        makThreshold: view.getUint16(dataOffset + 18),
+        // TODO(jwetzell): actually decode client block
+        sdtClientBlock: bytes.subarray(dataOffset + 20),
+      };
+      return {
+        vector,
+        data: wrapperData,
+      };
+    }
+    case SessionDataTransportVectors.ACK: {
+      return {
+        vector,
+        data: {
+          reliableSequenceNumber: view.getUint32(dataOffset),
+        },
+      };
+    }
     default:
       console.error(`unhandled SDT vector: ${vector}`);
       break;