start work towards DMP protocol decoding

README.md

@@ -1,7 +1,7 @@
 # acn-js
 not sure how far I will take this but messing around with E1.17 ACN protocol
 
-## areas
+## packet decoding
 - rlp
 - sdt
   - vectors    
@@ -23,4 +23,16 @@ not sure how far I will take this but messing around with E1.17 ACN protocol
     - [x] DISCONNECT
     - [x] DISCONNECTING
 - dmp
+  - vectors    
+    - [ ] GET_PROPERTY
+    - [ ] SET_PROPERTY
+    - [ ] GET_PROPERTY_REPLY
+    - [ ] EVENT
+    - [ ] SUBSCRIBE
+    - [ ] UNSUBSCRIBE
+    - [ ] GET_PROPERTY_FAIL
+    - [ ] SET_PROPERTY_FAIL
+    - [ ] SUBSCRIBE_ACCEPT
+    - [ ] SUBSCRIBE_REJECT
+    - [ ] SYNC_EVENT
 - ddl

packages/acn/src/enums.ts

@@ -1,5 +1,6 @@
 export enum Protocol {
   SDT = 1,
+  DMP,
 }
 
 export enum SDTVector {
@@ -22,6 +23,26 @@ export enum SDTVector {
   SESSIONS,
 }
 
+export enum DMPVector {
+  GET_PROPERTY = 1,
+  SET_PROPERTY,
+  GET_PROPERTY_REPLY,
+  EVENT,
+  RESERVED_1,
+  RESERVED_2,
+  SUBSCRIBE,
+  UNSUBSCRIBE,
+  GET_PROPERTY_FAIL,
+  SET_PROPERTY_FAIL,
+  RESERVED_3,
+  SUBSCRIBE_ACCEPT,
+  SUBSCRIBE_REJECT,
+  RESERVED_4,
+  RESERVED_5,
+  RESERVED_6,
+  SYNC_EVENT,
+}
+
 export enum TransportLayerAddressType {
   SDT_ADDR_NULL = 0,
   SDT_ADDR_IPV4,

packages/acn/src/pdu/dmp.ts

@@ -0,0 +1,77 @@
+import { DMPVector } from '../enums';
+import { DeviceManagementProtocolPDU, DMPAddressDataType, DMPGetPropertyData } from '../types';
+
+export function decode(bytes: Uint8Array): DeviceManagementProtocolPDU {
+  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
+  const flags = view.getUint8(0) >> 4;
+  const lengthFlag = ((flags >> 3) & 0x1) === 1;
+  const vectorFlag = ((flags >> 2) & 0x1) === 1;
+  const headerFlag = ((flags >> 1) & 0x1) === 1;
+
+  if (!vectorFlag) {
+    throw new Error('SDT PDU must have a vector');
+  }
+
+  const dataFlag = (flags & 0x1) === 1;
+
+  if (!dataFlag) {
+    // TODO(jwetzell): idk if this is true
+    throw new Error('SDT PDU must have data');
+  }
+
+  const lengthH = view.getUint8(0) & 0x0f;
+  let lengthOffset = 1;
+  const lengthL = view.getUint8(lengthOffset);
+
+  let length = (lengthH << 8) + lengthL;
+  if (lengthFlag) {
+    lengthOffset += 1;
+    const lengthX = view.getUint8(lengthOffset);
+    length = (lengthH << 16) + (lengthL << 8) + lengthX;
+  }
+  let vectorOffset = lengthOffset + 1;
+
+  if (lengthFlag) {
+    vectorOffset += 1;
+  }
+
+  const vector = view.getUint8(vectorOffset);
+
+  let headerOffset = (vectorOffset += 1);
+
+  const addressAndDataTypes = view.getUint8(headerOffset);
+  const addressType = (addressAndDataTypes >> 6) & 0x1;
+  const dataType = (addressAndDataTypes >> 4) & 0x3;
+  const elementSize = addressAndDataTypes & 0x11;
+
+  const addressAndDataType = {
+    addressType,
+    dataType,
+    elementSize
+  }
+ 
+  const dataOffset = headerOffset + 1;
+  // NOTE(jwetzell): flags/lengthH + lengthL + lengthX + vector + header
+  const dataLength = length - (1 + 1 + (lengthFlag ? 1 : 0) + 1 + 1);
+  const data = decodeData(vector, bytes.subarray(dataOffset, dataOffset + dataLength), addressAndDataType);
+  console.log('decoded Data', data)
+  return {
+    vector,
+    data
+  };
+}
+
+function decodeData(vector: number, bytes: Uint8Array, addressAndDataType: DMPAddressDataType): DMPGetPropertyData | Uint8Array {
+  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
+  console.log('pdu bytes', bytes)
+  console.log('pdu address data type', addressAndDataType)
+  switch (vector) {
+    default:
+      console.error(`unhandled DMP vector: ${vector}`);
+      return bytes;
+  }
+}
+
+export default {
+  decode,
+};

packages/acn/src/pdu/index.ts

@@ -1,6 +1,8 @@
 import rlp from './rlp';
 import sdt from './sdt';
+import dmp from './dmp';
 export default {
   rlp,
   sdt,
+  dmp,
 };

packages/acn/src/pdu/sdt.ts

@@ -1,5 +1,7 @@
+import pdu from '.';
 import { Protocol, SDTVector } from '../enums';
 import {
+  DeviceManagementProtocolPDU,
   SDTAckData,
   SDTConnectAcceptData,
   SDTConnectData,
@@ -113,10 +115,12 @@ function decodeClientBlock(bytes: Uint8Array) {
   const dataOffset = headerOffset + 6;
   // NOTE(jwetzell): flags/lengthH + lengthL + lengthX + vector + header
   const dataLength = length - (1 + 1 + (lengthFlag ? 1 : 0) + 2 + 6);
-  let data: SessionDataTransportPDU | Uint8Array = bytes.subarray(dataOffset, dataOffset + dataLength);
+  let data: SessionDataTransportPDU | DeviceManagementProtocolPDU | Uint8Array = bytes.subarray(dataOffset, dataOffset + dataLength);
 
   if (clientProtocol === Protocol.SDT) {
     data = decode(data);
+  } else if (clientProtocol === Protocol.DMP) {
+    data = pdu.dmp.decode(data)
   } else {
     console.error(`SDT client block contains unknown protocol: ${clientProtocol}`);
   }

packages/acn/src/types.ts

@@ -1,4 +1,4 @@
-import { TransportLayerAddressType, SDTVector, SDTReasonCode } from './enums';
+import { TransportLayerAddressType, SDTVector, SDTReasonCode, DMPVector } from './enums';
 
 export type UDPPreamble = {
   preambleSize: number;
@@ -133,9 +133,26 @@ export type SessionDataTransportPDU = {
     | Uint8Array;
 };
 
+export type DMPAddressDataType = {
+  addressType: number;
+  dataType: number;
+  elementSize: number;
+};
+
+export type DMPGetPropertyData = {
+  address: number
+}
+
+export type DMPSubscribePropertyData = DMPGetPropertyData
+
+export type DeviceManagementProtocolPDU = {
+  vector: DMPVector;
+  data: DMPGetPropertyData | DMPSubscribePropertyData | Uint8Array;
+};
+
 export type SDTClientBlock = {
   memberID: number;
   clientProtocol: number;
   association: number;
-  data: SessionDataTransportPDU | Uint8Array;
+  data: SessionDataTransportPDU | DeviceManagementProtocolPDU | Uint8Array;
 };