Add parsing of char. Fix infinite loop when parsing messages.

ifrunistuttgart · Feb 26, 2021 · b2eb3e0 · b2eb3e0
1 parent 768143b
commit b2eb3e0
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Showing 4 changed files with 21 additions and 6 deletions.
diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@gardsteinsvik/node-mavlink",
-  "version": "0.1.6",
+  "version": "0.1.7",
   "description": "A library for parsing and packing MAVLink 2 messages",
   "main": "lib/index.js",
   "types": "lib/index.d.ts",

diff --git a/src/mavlink-parser-base.ts b/src/mavlink-parser-base.ts
@@ -42,7 +42,7 @@ export abstract class MAVLinkParserBase {
 
         this.buffer = Buffer.concat([this.buffer, bytes]);
 
-        while (this.state == ParserState.WaitingForMagicByte && this.buffer.indexOf(this.start_marker) > -1) { // allow parsing multiple messages from a single call
+        while ((this.state == ParserState.WaitingForMagicByte && this.buffer.indexOf(this.start_marker) > -1) || this.state != ParserState.WaitingForMagicByte) { // allow parsing multiple messages from a single call
             if (this.state == ParserState.WaitingForMagicByte) {
                 // look for the defined magic byte
                 let message_start = this.buffer.indexOf(this.start_marker);
@@ -73,10 +73,10 @@ export abstract class MAVLinkParserBase {
                         const message = this.parseMessage(this.buffer.slice(0, this.expected_packet_length));
                         if (message) {
                             messages.push(message);
-                            this.buffer = this.buffer.slice(this.expected_packet_length);
                         }
+                        this.buffer = this.buffer.slice(this.expected_packet_length);
                     } catch (e) {
-                        //this.buffer = this.buffer.slice(1);
+                        this.buffer = this.buffer.slice(1);
                         throw e;
                     } finally {
                         // something was complete. Regardless of a complete message, drop the magic byte and restart.
@@ -85,6 +85,11 @@ export abstract class MAVLinkParserBase {
                     }
                 }
             }
+
+            // Checking if nothing more can be done
+            if (this.state == ParserState.WaitingForHeaderComplete || this.state == ParserState.WaitingForMessageComplete) {
+                break;
+            }
         }
 
         if (this.state == ParserState.WaitingForMagicByte) {

diff --git a/src/mavlink-v1/mavlink-parser-v1.ts b/src/mavlink-v1/mavlink-parser-v1.ts
@@ -108,7 +108,12 @@ export class MAVLinkParserV1 extends MAVLinkParserBase {
             case "double":
                 return bytes.readDoubleLE(start);
             case "char":
-                return bytes.toString('ascii', start, 1);
+                let nullTerminator = bytes.indexOf(0x00, start)
+                if (nullTerminator == -1) {
+                    return bytes.toString('ascii', start);
+                } else {
+                    return bytes.toString('ascii', start, nullTerminator);
+                }
         }
     }
 }
diff --git a/src/mavlink-v2/mavlink-parser-v2.ts b/src/mavlink-v2/mavlink-parser-v2.ts
@@ -117,7 +117,12 @@ export class MAVLinkParserV2 extends MAVLinkParserBase {
             case "double":
                 return bytes.readDoubleLE(start);
             case "char":
-                return bytes.toString('ascii', start, 1);
+                let nullTerminator = bytes.indexOf(0x00, start)
+                if (nullTerminator == -1) {
+                    return bytes.toString('ascii', start);
+                } else {
+                    return bytes.toString('ascii', start, nullTerminator);
+                }
         }
     }
 }