fix: ensure the payload format is valid

This commit should prevent some NPE issues encountered after the
parsing of the packet.

Related:

- #642
- #609
- #505

Backported from e8ffe9d

src/main/java/io/socket/client/Manager.java

@@ -2,6 +2,7 @@
 
 import io.socket.backo.Backoff;
 import io.socket.emitter.Emitter;
+import io.socket.parser.DecodingException;
 import io.socket.parser.IOParser;
 import io.socket.parser.Packet;
 import io.socket.parser.Parser;
@@ -370,10 +371,14 @@ private void onopen() {
             @Override
             public void call(Object... objects) {
                 Object data = objects[0];
-                if (data instanceof String) {
-                    Manager.this.ondata((String)data);
-                } else if (data instanceof byte[]) {
-                    Manager.this.ondata((byte[])data);
+                try {
+                    if (data instanceof String) {
+                        Manager.this.decoder.add((String) data);
+                    } else if (data instanceof byte[]) {
+                        Manager.this.decoder.add((byte[]) data);
+                    }
+                } catch (DecodingException e) {
+                    logger.fine("error while decoding the packet: " + e.getMessage());
                 }
             }
         }));
@@ -419,14 +424,6 @@ private void onpong() {
                 null != this.lastPing ? new Date().getTime() - this.lastPing.getTime() : 0);
     }
 
-    private void ondata(String data) {
-        this.decoder.add(data);
-    }
-
-    private void ondata(byte[] data) {
-        this.decoder.add(data);
-    }
-
     private void ondecoded(Packet packet) {
         this.emit(EVENT_PACKET, packet);
     }

src/main/java/io/socket/parser/DecodingException.java

@@ -0,0 +1,7 @@
+package io.socket.parser;
+
+public class DecodingException extends RuntimeException {
+    public DecodingException(String message) {
+        super(message);
+    }
+}

src/main/java/io/socket/parser/IOParser.java

@@ -1,7 +1,9 @@
 package io.socket.parser;
 
 import io.socket.hasbinary.HasBinary;
+import org.json.JSONArray;
 import org.json.JSONException;
+import org.json.JSONObject;
 import org.json.JSONTokener;
 
 import java.util.ArrayList;
@@ -14,10 +16,6 @@ final public class IOParser implements Parser {
 
     private static final Logger logger = Logger.getLogger(IOParser.class.getName());
 
-    private static Packet<String> error() {
-        return new Packet<String>(ERROR, "parser error");
-    }
-
     private IOParser() {}
 
     final public static class Encoder implements Parser.Encoder {
@@ -126,12 +124,16 @@ private static Packet decodeString(String str) {
             int i = 0;
             int length = str.length();
 
-            Packet<Object> p = new Packet<Object>(Character.getNumericValue(str.charAt(0)));
+            Packet<Object> p = new Packet<>(Character.getNumericValue(str.charAt(0)));
 
-            if (p.type < 0 || p.type > types.length - 1) return error();
+            if (p.type < 0 || p.type > types.length - 1) {
+                throw new DecodingException("unknown packet type " + p.type);
+            }
 
             if (BINARY_EVENT == p.type || BINARY_ACK == p.type) {
-                if (!str.contains("-") || length <= i + 1) return error();
+                if (!str.contains("-") || length <= i + 1) {
+                    throw new DecodingException("illegal attachments");
+                }
                 StringBuilder attachments = new StringBuilder();
                 while (str.charAt(++i) != '-') {
                     attachments.append(str.charAt(i));
@@ -170,7 +172,7 @@ private static Packet decodeString(String str) {
                     try {
                         p.id = Integer.parseInt(id.toString());
                     } catch (NumberFormatException e){
-                        return error();
+                        throw new DecodingException("invalid payload");
                     }
                 }
             }
@@ -181,7 +183,10 @@ private static Packet decodeString(String str) {
                     p.data = new JSONTokener(str.substring(i)).nextValue();
                 } catch (JSONException e) {
                     logger.log(Level.WARNING, "An error occured while retrieving data from JSONTokener", e);
-                    return error();
+                    throw new DecodingException("invalid payload");
+                }
+                if (!isPayloadValid(p.type, p.data)) {
+                    throw new DecodingException("invalid payload");
                 }
             }
 
@@ -191,6 +196,27 @@ private static Packet decodeString(String str) {
             return p;
         }
 
+        private static boolean isPayloadValid(int type, Object payload) {
+            switch (type) {
+                case Parser.CONNECT:
+                    return payload instanceof JSONObject;
+                case Parser.ERROR:
+                    return payload instanceof String;
+                case Parser.DISCONNECT:
+                    return payload == null;
+                case Parser.EVENT:
+                case Parser.BINARY_EVENT:
+                    return payload instanceof JSONArray
+                            && ((JSONArray) payload).length() > 0
+                            && !((JSONArray) payload).isNull(0);
+                case Parser.ACK:
+                case Parser.BINARY_ACK:
+                    return payload instanceof JSONArray;
+                default:
+                    return false;
+            }
+        }
+
         @Override
         public void destroy() {
             if (this.reconstructor != null) {

src/test/java/io/socket/parser/ByteArrayTest.java

@@ -1,15 +1,15 @@
 package io.socket.parser;
 
-import io.socket.emitter.Emitter;
 import org.json.JSONArray;
 import org.json.JSONException;
-import org.json.JSONObject;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
+import static java.util.Arrays.asList;
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
 
@@ -20,29 +20,29 @@ public class ByteArrayTest {
 
     @Test
     public void encodeByteArray() {
-        Packet<byte[]> packet = new Packet<byte[]>(Parser.BINARY_EVENT);
-        packet.data = "abc".getBytes(Charset.forName("UTF-8"));
+        Packet<JSONArray> packet = new Packet<>(Parser.BINARY_EVENT);
+        packet.data = new JSONArray(asList("abc", "abc".getBytes(StandardCharsets.UTF_8)));
         packet.id = 23;
         packet.nsp = "/cool";
         Helpers.testBin(packet);
     }
 
     @Test
     public void encodeByteArray2() {
-        Packet<byte[]> packet = new Packet<byte[]>(Parser.BINARY_EVENT);
-        packet.data = new byte[2];
+        Packet<JSONArray> packet = new Packet<>(Parser.BINARY_EVENT);
+        packet.data = new JSONArray(asList("2", new byte[] { 0, 1 }));
         packet.id = 0;
         packet.nsp = "/";
         Helpers.testBin(packet);
     }
 
     @Test
     public void encodeByteArrayDeepInJson() throws JSONException {
-        JSONObject data = new JSONObject("{a: \"hi\", b: {}, c: {a: \"bye\", b: {}}}");
-        data.getJSONObject("b").put("why", new byte[3]);
-        data.getJSONObject("c").getJSONObject("b").put("a", new byte[6]);
+        JSONArray data = new JSONArray("[{a: \"hi\", b: {}, c: {a: \"bye\", b: {}}}]");
+        data.getJSONObject(0).getJSONObject("b").put("why", new byte[3]);
+        data.getJSONObject(0).getJSONObject("c").getJSONObject("b").put("a", new byte[6]);
 
-        Packet<JSONObject> packet = new Packet<JSONObject>(Parser.BINARY_EVENT);
+        Packet<JSONArray> packet = new Packet<>(Parser.BINARY_EVENT);
         packet.data = data;
         packet.id = 999;
         packet.nsp = "/deep";
@@ -51,10 +51,10 @@ public void encodeByteArrayDeepInJson() throws JSONException {
 
     @Test
     public void encodeDeepBinaryJSONWithNullValue() throws JSONException {
-        JSONObject data = new JSONObject("{a: \"b\", c: 4, e: {g: null}, h: null}");
-        data.put("h", new byte[9]);
+        JSONArray data = new JSONArray("[{a: \"b\", c: 4, e: {g: null}, h: null}]");
+        data.getJSONObject(0).put("h", new byte[9]);
 
-        Packet<JSONObject> packet = new Packet<JSONObject>(Parser.BINARY_EVENT);
+        Packet<JSONArray> packet = new Packet<>(Parser.BINARY_EVENT);
         packet.data = data;
         packet.nsp = "/";
         packet.id = 600;

src/test/java/io/socket/parser/Helpers.java

@@ -1,6 +1,5 @@
 package io.socket.parser;
 
-import io.socket.emitter.Emitter;
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
@@ -10,6 +9,7 @@
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
+import static org.junit.Assert.fail;
 
 @RunWith(JUnit4.class)
 public class Helpers {
@@ -35,13 +35,10 @@ public void call(Packet packet) {
 
     public static void testDecodeError(final String errorMessage) {
         Parser.Decoder decoder = new IOParser.Decoder();
-        decoder.onDecoded(new IOParser.Decoder.Callback() {
-            @Override
-            public void call(Packet packet) {
-                assertPacket(errorPacket, packet);
-            }
-        });
-        decoder.add(errorMessage);
+        try {
+            decoder.add(errorMessage);
+            fail();
+        } catch (DecodingException e) {}
     }
 
     @SuppressWarnings("unchecked")

src/test/java/io/socket/parser/ParserTest.java

@@ -63,5 +63,8 @@ public void decodeInError() throws JSONException {
         Helpers.testDecodeError(Parser.EVENT + "2sd");
         // event with invalid json data
         Helpers.testDecodeError(Parser.EVENT + "2[\"a\",1,{asdf}]");
+        Helpers.testDecodeError(Parser.EVENT + "2{}");
+        Helpers.testDecodeError(Parser.EVENT + "2[]");
+        Helpers.testDecodeError(Parser.EVENT + "2[null]");
     }
 }