fix: dtx parsing exception when instrument service actively push data (…

…#94)
appium · Aug 2, 2022 · 769face · 769face
1 parent e0710ef
commit 769face
Showing 1 changed file with 31 additions and 15 deletions.
diff --git a/lib/instrument/headers.js b/lib/instrument/headers.js
@@ -10,12 +10,14 @@ const DTX_MESSAGE_AUX_HEADER = 0x01F0;
 const DTX_AUXILIARY_MAGIC = 0xa;
 
 const FLAG_TYPES = Object.freeze({
+  push: 0,
   recv: 1,
   send: 2,
   reply: 3
 });
 
 const AUX_TYPES = Object.freeze({
+  Text: 1,
   NSKeyed: 2,
   UInt32LE: 3,
   BigUInt64LE: 4,
@@ -116,7 +118,7 @@ class DTXMessagePayloadHeader {
 
   /**
    * @param headerBuffer
-   * @returns {{flags: number, totalLength: bigint, auxLength: number}}
+   * @returns {DTXMessagePayloadHeaderObject}
    */
   static parse (headerBuffer) {
     return {
@@ -159,22 +161,33 @@ class DTXMessageAux {
 
   /**
    * Parses nskeyed Buffer into js array
-   * @param headerBuffer
+   * @param {Buffer} headerBuffer
+   * @param {DTXMessagePayloadHeaderObject} payloadHeader
    * @returns {Array}
    */
-  static parse (headerBuffer) {
+  static parse (headerBuffer, payloadHeader) {
     let cursor = 0;
     const data = [];
     const length = headerBuffer.readBigInt64LE(8);
     cursor += 16;
     while (cursor <= length) {
-      const m = headerBuffer.readUInt32LE(cursor);
-      if (m !== DTX_AUXILIARY_MAGIC) {
-        throw new Error(`incorrect auxiliary magic: ${m}`);
+      if (payloadHeader.flags !== FLAG_TYPES.push) {
+        const m = headerBuffer.readUInt32LE(cursor);
+        cursor += 4;
+        if (m !== DTX_AUXILIARY_MAGIC) {
+          throw new Error(`incorrect auxiliary magic: ${m}`);
+        }
       }
-      const type = headerBuffer.readUInt32LE(cursor + 4);
-      cursor += 8;
+      const type = headerBuffer.readUInt32LE(cursor);
+      cursor += 4;
       switch (type) {
+        case AUX_TYPES.Text: {
+          const strLen = headerBuffer.readUInt32LE(cursor);
+          cursor += 4;
+          data.push(headerBuffer.slice(cursor, cursor + strLen));
+          cursor += strLen;
+          break;
+        }
         case AUX_TYPES.NSKeyed: {
           const strLen = headerBuffer.readUInt32LE(cursor);
           cursor += 4;
@@ -399,17 +412,20 @@ class DTXMessage {
       return ret;
     }
     if (ret._payloadHeader.auxLength > 0) {
-      ret.auxiliaries = DTXMessageAux.parse(payloadBuf.slice(cursor, cursor + ret._payloadHeader.auxLength));
+      ret.auxiliaries = DTXMessageAux.parse(payloadBuf.slice(cursor, cursor + ret._payloadHeader.auxLength), ret._payloadHeader);
       cursor += ret._payloadHeader.auxLength;
     }
 
     const data = payloadBuf.slice(cursor, cursor + payloadBuf.length);
-    for (const fun of [unarchive, plistlib.parseBuffer]) {
-      try {
-        ret.selector = fun(data);
-        break;
-      } catch (e) {
-        ret.selector = new InstrumentRPCParseError(data);
+    ret.selector = data;
+    if (data.length > 0) {
+      for (const fun of [unarchive, plistlib.parseBuffer]) {
+        try {
+          ret.selector = fun(data);
+          break;
+        } catch (e) {
+          ret.selector = new InstrumentRPCParseError(data);
+        }
       }
     }
     return ret;