Bugfixes in BinaryStruct and some Tests for MDNS

src/zutil/ByteUtil.java

@@ -65,7 +65,6 @@ public class ByteUtil {
      * @return a new byte containing a sub byte defined by the index and length
      */
     public static byte getBits(byte data, int index, int length){
-        length--;
         byte ret = (byte) (data & getBitMask(index, length));
         return  ret;
     }
@@ -77,6 +76,7 @@ public class ByteUtil {
      * @param   length  length of mask from index, valid values 1-8
      */
     public static byte getBitMask(int index, int length) {
+        --length;
         if(0 > index || index > 7)
             throw new IllegalArgumentException("Invalid index argument, allowed value is 0-7");
         if(length < 0 && index-length < 0)

src/zutil/net/dns/DNSPacketHeader.java

@@ -30,7 +30,7 @@ import zutil.parser.binary.BinaryStruct;
  * Created by Ziver on 2016-02-09.
  * Reference: http://tools.ietf.org/html/rfc1035
  */
-public class DNSPacket implements BinaryStruct {
+public class DNSPacketHeader implements BinaryStruct {
     public static final int OPCODE_QUERY = 0;
     public static final int OPCODE_IQUERY = 1;
     public static final int OPCODE_STATUS = 2;
@@ -42,9 +42,33 @@ public class DNSPacket implements BinaryStruct {
     public static final int RCODE_NOT_IMPLEMENTED = 4;
     public static final int RCODE_REFUSED = 5;
 
+    /*
+    Header section format
+
+    The header contains the following fields:
+
+                                        1  1  1  1  1  1
+          0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                      ID                       |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                    QDCOUNT                    |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                    ANCOUNT                    |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                    NSCOUNT                    |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                    ARCOUNT                    |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+
+    where:
+     */
+
 
     @BinaryField(index=0, length=16)
-    int id;
+    public int id;
 
     //////////////// FLAGS
     //@BinaryField(index=10, length=16)
@@ -54,7 +78,7 @@ public class DNSPacket implements BinaryStruct {
      * query (0), or a response (1).
      */
     @BinaryField(index=10, length=1)
-    boolean flagQueryResponse;
+    public boolean flagQueryResponse;
     /**
      * A four bit field that specifies kind of query in this message.
      * <pre>
@@ -64,21 +88,21 @@ public class DNSPacket implements BinaryStruct {
      * </pre>
      */
     @BinaryField(index=11, length=4)
-    int flagOperationCode;
+    public int flagOperationCode;
     /**
      * This bit is valid in responses,
      * and specifies that the responding name server is an
      * authority for the domain name in question section.
      */
     @BinaryField(index=12, length=1)
-    boolean flagAuthoritativeAnswer;
+    public boolean flagAuthoritativeAnswer;
     /**
      * specifies that this message was truncated
      * due to length greater than that permitted on the
      * transmission channel.
      */
     @BinaryField(index=13, length=1)
-    boolean flagTruncation;
+    public boolean flagTruncation;
     /**
      * this bit may be set in a query and
      * is copied into the response.  If RD is set, it directs
@@ -86,20 +110,20 @@ public class DNSPacket implements BinaryStruct {
      * Recursive query support is optional.
      */
     @BinaryField(index=14, length=1)
-    boolean flagRecursionDesired;
+    public boolean flagRecursionDesired;
     /**
      * this be is set or cleared in a
      * response, and denotes whether recursive query support is
      * available in the name server.
      */
     @BinaryField(index=15, length=1)
-    boolean flagRecursionAvailable;
+    public boolean flagRecursionAvailable;
     /**
      * Reserved for future use.  Must be zero in all queries
      * and responses.
      */
     @BinaryField(index=16, length=3)
-    private int z;
+    protected int z;
     /**
      * this field is set as part of responses.
      * The values have the following interpretation:
@@ -123,7 +147,7 @@ public class DNSPacket implements BinaryStruct {
      *</pre>
      */
     @BinaryField(index=17, length=4)
-    int flagResponseCode;
+    public int flagResponseCode;
 
 
     //////////////// COUNTS
@@ -132,115 +156,57 @@ public class DNSPacket implements BinaryStruct {
      * Specifying the number of entries in the question section.
      */
     @BinaryField(index=20, length=16)
-    int countQuestion;
+    public int countQuestion;
     /**
      * Answer Record Count.
      * specifying the number of resource records in
      * the answer section.
      */
     @BinaryField(index=21, length=16)
-    int countAnswerRecord;
+    public int countAnswerRecord;
     /**
      * Name Server (Authority Record) Count.
      * Specifying the number of name server resource records
      * in the authority records section.
      */
     @BinaryField(index=22, length=16)
-    int countNameServer;
+    public int countNameServer;
     /**
      * Additional Record Count.
      * Specifying the number of resource records in the
      * additional records section
      */
     @BinaryField(index=23, length=16)
-    int countAdditionalRecord;
+    public int countAdditionalRecord;
 
 
 
-    /*
-    Question section format
-                                        1  1  1  1  1  1
-          0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-        |                                               |
-        /                     QNAME                     /
-        /                                               /
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-        |                     QTYPE                     |
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-        |                     QCLASS                    |
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
 
-    where:
 
-    QNAME           a domain name represented as a sequence of labels, where
-                    each label consists of a length octet followed by that
-                    number of octets.  The domain name terminates with the
-                    zero length octet for the null label of the root.  Note
-                    that this field may be an odd number of octets; no
-                    padding is used.
 
-    QTYPE           a two octet code which specifies the type of the query.
+    public void setDefaultQueryData() {
-                    The values for this field include all codes valid for a
+        // Set all flags to zero
-                    TYPE field, together with some more general codes which
+        flagQueryResponse = false;
-                    can match more than one type of RR.
+        flagOperationCode = 0;
+        flagAuthoritativeAnswer = false;
+        flagTruncation = false;
+        flagRecursionDesired = false;
+        flagRecursionAvailable = false;
+        z = 0;
+        flagResponseCode = 0;
+    }
 
-    QCLASS          a two octet code that specifies the class of the query.
+    public void setDefaultResponseData() {
-                    For example, the QCLASS field is IN for the Internet.
+        flagQueryResponse = true;
-    */
+        flagAuthoritativeAnswer = true;
 
-    /*
+        // Set the rest to zero
-    Resource record format
+        // TODO: all flags should not be zeroed
-
+        flagOperationCode = 0;
-    The answer, authority, and additional sections all share the same
+        flagTruncation = false;
-    format: a variable number of resource records, where the number of
+        flagRecursionDesired = false;
-    records is specified in the corresponding count field in the header.
+        flagRecursionAvailable = false;
-    Each resource record has the following format:
+        z = 0;
-                                        1  1  1  1  1  1
+        flagResponseCode = 0;
-          0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+    }
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-        |                                               |
-        /                                               /
-        /                      NAME                     /
-        |                                               |
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-        |                      TYPE                     |
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-        |                     CLASS                     |
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-        |                      TTL                      |
-        |                                               |
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-        |                   RDLENGTH                    |
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--|
-        /                     RDATA                     /
-        /                                               /
-        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-
-    where:
-
-    NAME            a domain name to which this resource record pertains.
-
-    TYPE            two octets containing one of the RR type codes.  This
-                    field specifies the meaning of the data in the RDATA
-                    field.
-
-    CLASS           two octets which specify the class of the data in the
-                    RDATA field.
-
-    TTL             a 32 bit unsigned integer that specifies the time
-                    interval (in seconds) that the resource record may be
-                    cached before it should be discarded.  Zero values are
-                    interpreted to mean that the RR can only be used for the
-                    transaction in progress, and should not be cached.
-
-    RDLENGTH        an unsigned 16 bit integer that specifies the length in
-                    octets of the RDATA field.
-
-    RDATA           a variable length string of octets that describes the
-                    resource.  The format of this information varies
-                    according to the TYPE and CLASS of the resource record.
-                    For example, the if the TYPE is A and the CLASS is IN,
-                    the RDATA field is a 4 octet ARPA Internet address.
-     */
 }

src/zutil/net/dns/DNSPacketQuestion.java

@@ -0,0 +1,69 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 Ziver Koc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package zutil.net.dns;
+
+import zutil.parser.binary.BinaryStruct;
+
+/**
+ * Created by Ziver on 2016-02-09.
+ * Reference: http://tools.ietf.org/html/rfc1035
+ */
+public class DNSPacketQuestion implements BinaryStruct {
+
+    /*
+    Question section format
+                                        1  1  1  1  1  1
+          0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                                               |
+        /                     QNAME                     /
+        /                                               /
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                     QTYPE                     |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                     QCLASS                    |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+
+    where:
+
+    QNAME           a domain name represented as a sequence of labels, where
+                    each label consists of a length octet followed by that
+                    number of octets.  The domain name terminates with the
+                    zero length octet for the null label of the root.  Note
+                    that this field may be an odd number of octets; no
+                    padding is used.
+
+    QTYPE           a two octet code which specifies the type of the query.
+                    The values for this field include all codes valid for a
+                    TYPE field, together with some more general codes which
+                    can match more than one type of RR.
+
+    QCLASS          a two octet code that specifies the class of the query.
+                    For example, the QCLASS field is IN for the Internet.
+    */
+
+
+
+}

src/zutil/net/dns/DNSPacketResource.java

@@ -0,0 +1,88 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 Ziver Koc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package zutil.net.dns;
+
+import zutil.parser.binary.BinaryStruct;
+
+/**
+ * Created by Ziver on 2016-02-09.
+ * Reference: http://tools.ietf.org/html/rfc1035
+ */
+public class DNSPacketResource implements BinaryStruct {
+
+    /*
+    The answer, authority, and additional sections all share the same
+    format: a variable number of resource records, where the number of
+    records is specified in the corresponding count field in the header.
+    Each resource record has the following format:
+                                        1  1  1  1  1  1
+          0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                                               |
+        /                                               /
+        /                      NAME                     /
+        |                                               |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                      TYPE                     |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                     CLASS                     |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                      TTL                      |
+        |                                               |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                   RDLENGTH                    |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--|
+        /                     RDATA                     /
+        /                                               /
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+
+    where:
+
+    NAME            a domain name to which this resource record pertains.
+
+    TYPE            two octets containing one of the RR type codes.  This
+                    field specifies the meaning of the data in the RDATA
+                    field.
+
+    CLASS           two octets which specify the class of the data in the
+                    RDATA field.
+
+    TTL             a 32 bit unsigned integer that specifies the time
+                    interval (in seconds) that the resource record may be
+                    cached before it should be discarded.  Zero values are
+                    interpreted to mean that the RR can only be used for the
+                    transaction in progress, and should not be cached.
+
+    RDLENGTH        an unsigned 16 bit integer that specifies the length in
+                    octets of the RDATA field.
+
+    RDATA           a variable length string of octets that describes the
+                    resource.  The format of this information varies
+                    according to the TYPE and CLASS of the resource record.
+                    For example, the if the TYPE is A and the CLASS is IN,
+                    the RDATA field is a 4 octet ARPA Internet address.
+     */
+
+}

src/zutil/net/dns/MulticastDNSClient.java

@@ -33,7 +33,6 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.net.DatagramPacket;
 import java.net.InetAddress;
-import java.net.UnknownHostException;
 
 /**
  * Created by Ziver
@@ -49,29 +48,25 @@ public class MulticastDNSClient extends ThreadedUDPNetwork implements ThreadedUD
     }
 
 
-    public void sendProbe() {
+    public void sendProbe() throws IOException {
-        try {
+        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
-            ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+        BinaryStructOutputStream out = new BinaryStructOutputStream(buffer);
-            BinaryStructOutputStream out = new BinaryStructOutputStream(buffer);
 
-            DNSPacket header = new DNSPacket();
+        DNSPacketHeader header = new DNSPacketHeader();
-            out.write(header);
+        out.write(header);
 
-            DatagramPacket packet = null;
+        DatagramPacket packet = null;
 
-            packet = new DatagramPacket(
+        packet = new DatagramPacket(
-                    buffer.toByteArray(), buffer.size(),
+                buffer.toByteArray(), buffer.size(),
-                    InetAddress.getByName( MDNS_MULTICAST_ADDR ),
+                InetAddress.getByName( MDNS_MULTICAST_ADDR ),
-                    MDNS_MULTICAST_PORT );
+                MDNS_MULTICAST_PORT );
-            send(packet);
+        send(packet);
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
     }
 
     @Override
     public void receivedPacket(DatagramPacket packet, ThreadedUDPNetwork network) {
-        DNSPacket header = new DNSPacket();
+        DNSPacketHeader header = new DNSPacketHeader();
         BinaryStructInputStream.read(header, packet.getData());
     }
 }

src/zutil/parser/binary/BinaryFieldData.java

@@ -1,12 +1,15 @@
 package zutil.parser.binary;
 
 
+import java.io.InvalidClassException;
+import java.io.InvalidObjectException;
 import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 
+import zutil.ByteUtil;
 import zutil.converter.Converter;
 import zutil.parser.binary.BinaryStruct.BinaryField;
 
@@ -24,7 +27,7 @@ public class BinaryFieldData implements Comparable<BinaryFieldData> {
     protected static List<BinaryFieldData> getStructFieldList(Class<? extends BinaryStruct> clazz){
         if (!cache.containsKey(clazz)) {
             ArrayList<BinaryFieldData> list = new ArrayList<>();
-            for (Field field : clazz.getFields()) {
+            for (Field field : clazz.getDeclaredFields()) {
                 if (field.isAnnotationPresent(BinaryField.class))
                     list.add(new BinaryFieldData(field));
             }
@@ -56,15 +59,17 @@ public class BinaryFieldData implements Comparable<BinaryFieldData> {
         }
     }
 
-    // TODO: variable length support
     protected byte[] getValue(Object obj){
         try {
+            field.setAccessible(true);
             if (field.getType() == Boolean.class || field.getType() == boolean.class)
                 return new byte[]{ (byte)(field.getBoolean(obj) ? 0x01 : 0x00) };
             else if (field.getType() == Integer.class || field.getType() == int.class)
                 return Converter.toBytes(field.getInt(obj));
             else if (field.getType() == String.class)
                 return ((String)(field.get(obj))).getBytes();
+            else
+                throw new UnsupportedOperationException("Unsupported BinaryStruct field class: "+ field.getClass());
         } catch (IllegalAccessException e){
             e.printStackTrace();
         }

src/zutil/parser/binary/BinaryStructOutputStream.java

@@ -76,7 +76,7 @@ public class BinaryStructOutputStream {
             byte[] data = field.getValue(struct);
 
             int fieldBitLength = field.getBitLength();
-            for (int i=data.length-1; fieldBitLength>0; fieldBitLength-=8, --i) {
+            for (int i=(int)Math.ceil(fieldBitLength/8.0)-1; fieldBitLength>0; fieldBitLength-=8, --i) {
                 byte b = data[i];
                 if (restBitLength == 0 && fieldBitLength >= 8)
                     out.write(0xFF & b);

test/zutil/net/dns/DNSPacketTest.java

@@ -0,0 +1,66 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2015 Ziver Koc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package zutil.net.dns;
+
+import org.junit.Test;
+import zutil.parser.binary.BinaryStructOutputStream;
+
+import java.io.IOException;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Created by Ziver
+ */
+public class DNSPacketTest {
+
+    @Test
+    public void headerQueryTest() throws IOException {
+        DNSPacketHeader header = new DNSPacketHeader();
+        header.setDefaultQueryData();
+        header.countQuestion = 1;
+
+        byte[] data = BinaryStructOutputStream.serialize(header);
+        assertEquals("header length", 12, data.length);
+        assertEquals("Flag byte1", 0x00, data[2]);
+        assertEquals("Flag byte2", 0x00, data[3]);
+        assertEquals("Question count byte1", 0x00, data[4]);
+        assertEquals("Question count byte2", 0x01, data[5]);
+    }
+
+    @Test
+    public void headerResponseTest() throws IOException {
+        DNSPacketHeader header = new DNSPacketHeader();
+        header.setDefaultResponseData();
+        header.countAnswerRecord = 1;
+
+        byte[] data = BinaryStructOutputStream.serialize(header);
+        assertEquals("header length", 12, data.length);
+        assertEquals("Flag byte1", (byte)0x84, data[2]);
+        assertEquals("Flag byte2", (byte)0x00, data[3]);
+        assertEquals("Answer count byte1", 0x00, data[6]);
+        assertEquals("Answer count byte2", 0x01, data[7]);
+    }
+}

test/zutil/parser/binary/BinaryStructOutputStreamTest.java

@@ -42,7 +42,7 @@ public class BinaryStructOutputStreamTest {
     public void basicIntTest() throws IOException {
         BinaryStruct struct = new BinaryStruct() {
             @BinaryField(index=1, length=32)
-            public int i1 = 1;
+            int i1 = 1;
             @BinaryField(index=2, length=32)
             public int i2 = 2;
         };
@@ -51,6 +51,20 @@ public class BinaryStructOutputStreamTest {
         assertArrayEquals(new byte[]{0,0,0,1, 0,0,0,2}, data);
     }
 
+    @Test
+    public void shortIntTest() throws IOException {
+        BinaryStruct struct = new BinaryStruct() {
+            @BinaryField(index=1, length=16)
+            int i1 = 1;
+            @BinaryField(index=2, length=16)
+            int i2 = 2;
+        };
+
+        byte[] data = BinaryStructOutputStream.serialize(struct);
+        assertArrayEquals(new byte[]{0,1, 0,2}, data);
+    }
+
+
     @Test
     public void basicBooleanTest() throws IOException {
         BinaryStruct struct = new BinaryStruct() {