Fixed DNS FQDN parsing

src/zutil/io/PositionalInputStream.java

@@ -16,7 +16,7 @@ public class PositionalInputStream extends FilterInputStream {
     /**
      * @param in the underlying input stream.
      */
-    protected PositionalInputStream(InputStream in) {
+    public PositionalInputStream(InputStream in) {
         super(in);
     }
 
@@ -60,8 +60,8 @@ public class PositionalInputStream extends FilterInputStream {
     }
 
     @Override
-    public void mark(int readlimit) {
+    public void mark(int readLimit) {
-        super.mark(readlimit);
+        super.mark(readLimit);
 
         synchronized(this) {
             mark = pos;

src/zutil/net/dns/MulticastDnsClient.java

@@ -78,7 +78,6 @@ public class MulticastDnsClient extends ThreadedUDPNetwork implements ThreadedUD
         int id = 0; // Needs to be zero when doing multicast
         activeProbes.add(id);
         ByteArrayOutputStream buffer = new ByteArrayOutputStream();
-        BinaryStructOutputStream out = new BinaryStructOutputStream(buffer);
 
         DnsPacket dnsPacket = new DnsPacket();
         dnsPacket.getHeader().id = id;
@@ -87,7 +86,7 @@ public class MulticastDnsClient extends ThreadedUDPNetwork implements ThreadedUD
                 domain,
                 DnsConstants.TYPE.SRV,
                 DnsConstants.CLASS.IN));
-        dnsPacket.write(out);
+        dnsPacket.write(buffer);
 
         DatagramPacket udpPacket = new DatagramPacket(
                 buffer.toByteArray(), buffer.size(),
@@ -106,8 +105,7 @@ public class MulticastDnsClient extends ThreadedUDPNetwork implements ThreadedUD
         try {
             ByteArrayInputStream buffer = new ByteArrayInputStream(packet.getData(),
                     packet.getOffset(), packet.getLength());
-            BinaryStructInputStream in = new BinaryStructInputStream(buffer);
+            DnsPacket dnsPacket = DnsPacket.read(buffer);
-            DnsPacket dnsPacket = DnsPacket.read(in);
 
             //System.out.println("Received:\n" +ByteUtil.toFormattedString(packet.getData(), packet.getOffset(), packet.getLength()));
             MultiPrintStream.out.dump(dnsPacket,3);

src/zutil/net/dns/MulticastDnsServer.java

@@ -112,8 +112,7 @@ public class MulticastDnsServer extends ThreadedUDPNetwork implements ThreadedUD
         try {
             ByteArrayInputStream buffer = new ByteArrayInputStream(packet.getData(),
                     packet.getOffset(), packet.getLength());
-            BinaryStructInputStream in = new BinaryStructInputStream(buffer);
+            DnsPacket dnsPacket = DnsPacket.read(buffer);
-            DnsPacket dnsPacket = DnsPacket.read(in);
 
             // Just handle queries and no responses
             if (! dnsPacket.getHeader().flagQueryResponse) {
@@ -121,9 +120,8 @@ public class MulticastDnsServer extends ThreadedUDPNetwork implements ThreadedUD
 
                 if (response != null) {
                     ByteArrayOutputStream outBuffer = new ByteArrayOutputStream();
-                    BinaryStructOutputStream out = new BinaryStructOutputStream(outBuffer);
+                    response.write(outBuffer);
-                    response.write(out);
+                    outBuffer.close();
-                    out.close();
 
                     DatagramPacket outPacket = new DatagramPacket(
                             outBuffer.toByteArray(), outBuffer.size(),

src/zutil/net/dns/packet/DnsPacket.java

@@ -24,10 +24,13 @@
 
 package zutil.net.dns.packet;
 
+import zutil.io.PositionalInputStream;
 import zutil.parser.binary.BinaryStructInputStream;
 import zutil.parser.binary.BinaryStructOutputStream;
 
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -94,7 +97,9 @@ public class DnsPacket {
     }
 
 
-    public static DnsPacket read(BinaryStructInputStream structIn) throws IOException {
+    public static DnsPacket read(InputStream in) throws IOException {
+        BinaryStructInputStream structIn = new BinaryStructInputStream(new PositionalInputStream(in));
+
         DnsPacket packet = new DnsPacket();
         structIn.read(packet.header);
 
@@ -116,7 +121,9 @@ public class DnsPacket {
         }
     }
 
-    public void write(BinaryStructOutputStream structOut) throws IOException {
+    public void write(OutputStream out) throws IOException {
+        BinaryStructOutputStream structOut = new BinaryStructOutputStream(out);
+
         structOut.write(header);
 
         for (DnsPacketQuestion question : questions)

src/zutil/net/dns/packet/FQDNStringSerializer.java

@@ -24,40 +24,64 @@
 
 package zutil.net.dns.packet;
 
+import zutil.io.PositionalInputStream;
 import zutil.parser.binary.BinaryFieldData;
 import zutil.parser.binary.BinaryFieldSerializer;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.HashMap;
 
 /**
  * A serializer class that can read and write a DNS FQDN in binary format.
  */
 public class FQDNStringSerializer implements BinaryFieldSerializer<String> {
+    private HashMap<Integer, String> stringCache = new HashMap<>();
+
 
     public String read(InputStream in, BinaryFieldData field) throws IOException {
-        StringBuilder str = new StringBuilder();
+        StringBuilder buffer = new StringBuilder();
+        int pos = (int) ((PositionalInputStream) in).getPosition();
         int c;
 
         while ((c=in.read()) > 0) {
-            if (str.length() > 0) // Don't add dot to first loop
+            if (buffer.length() > 0) // Don't add dot to first loop
-                str.append('.');
+                buffer.append('.');
 
             if ((c & 0b1100_0000) == 0b1100_0000) {
-                // This a offset pointer to the String data
+                // This is an offset pointer to the String data
                 int offset = (c & 0b0011_1111) << 8;
                 offset |= in.read() & 0b1111_1111;
-                str.append(offset);
+
+                if (stringCache.containsKey(offset))
+                    buffer.append(stringCache.get(offset));
+                else
+                    buffer.append('<').append(offset).append('>');
                 break; // PTR is always the last part of the FQDN
             } else {
-                // Normal String data
+                // Read normal String data
                 for (int i = 0; i < c; ++i) {
-                    str.append((char) in.read());
+                    buffer.append((char) in.read());
                 }
             }
         }
-        return str.toString();
+
+        String output = buffer.toString();
+
+        // Populate cache
+        if (in instanceof PositionalInputStream) {
+            stringCache.put(pos, output);
+            for (int index = 0; index >= 0;) {
+                index = buffer.indexOf(".", index);
+                if (index >= 0) {
+                    ++index;
+                    stringCache.put(pos + index, buffer.substring(index));
+                }
+            }
+        }
+
+        return output;
     }
 
     public void write(OutputStream out, String domain, BinaryFieldData field) throws IOException {
@@ -70,5 +94,4 @@ public class FQDNStringSerializer implements BinaryFieldSerializer<String> {
         }
         out.write(0);
     }
-
 }

src/zutil/parser/binary/BinaryFieldSerializer.java

@@ -29,15 +29,13 @@ import java.io.InputStream;
 import java.io.OutputStream;
 
 /**
- * An Interface where custom field parser and writer can be implemented.
+ * An Interface defining a custom field parser and writer.
  * <p></p>
- * One instance of the serializer and will have the scope of the methods
+ * One singleton instance of the serializer will be instantiated for the lifetime of the
- * {@link BinaryStructInputStream#read(BinaryStruct)} and {@link BinaryStructOutputStream#write(BinaryStruct)}
+ * {@link BinaryStructInputStream} and {@link BinaryStructOutputStream} objects.
- * where as it will be deallocated after the methods have returned.
  * <p></p>
  * NOTE: Partial octet serializing not supported.
  *
- * Created by Ziver on 2016-04-11.
  */
 public interface BinaryFieldSerializer<T> {
 

src/zutil/parser/binary/BinaryStructInputStream.java

@@ -35,7 +35,7 @@ import java.util.Map;
 
 /**
  * A stream class that parses a byte stream into binary struct objects.
- * <p><p/>
+ * <p></p>
  * Limitations:<br>
  *  - Does not support sub binary objects.<br>
  *
@@ -47,6 +47,9 @@ public class BinaryStructInputStream {
     private byte data;
     private int dataBitIndex = -1;
 
+    private Map<Class, BinaryFieldSerializer> serializerCache = new HashMap<>();
+
+
     public BinaryStructInputStream(InputStream in) {
         this.in = in;
     }
@@ -78,7 +81,6 @@ public class BinaryStructInputStream {
      */
     public int read(BinaryStruct struct) throws IOException {
         List<BinaryFieldData> structDataList = BinaryFieldData.getStructFieldList(struct.getClass());
-        Map<Class, BinaryFieldSerializer> serializerCache = new HashMap<>();
 
         int totalReadLength = 0;
         for (BinaryFieldData field : structDataList) {

src/zutil/parser/binary/BinaryStructOutputStream.java

@@ -36,7 +36,7 @@ import java.util.Map;
 
 /**
  * A stream class that generates a byte stream from a binary struct objects.
- * <p><p/>
+ * <p></p>
  * Limitations:<br>
  *  - Does not support sub binary objects.<br>
  *
@@ -48,6 +48,8 @@ public class BinaryStructOutputStream {
     private byte rest;
     private int restBitLength; // length from Most Significant Bit
 
+    private Map<Class, BinaryFieldSerializer> serializerCache = new HashMap<>();
+
 
     public BinaryStructOutputStream(OutputStream out) {
         this.out = out;
@@ -88,7 +90,6 @@ public class BinaryStructOutputStream {
      */
     public void write(BinaryStruct struct) throws IOException {
         List<BinaryFieldData> structDataList = BinaryFieldData.getStructFieldList(struct.getClass());
-        Map<Class, BinaryFieldSerializer> serializerCache = new HashMap<>();
 
         for (BinaryFieldData field : structDataList) {
             if (field.hasSerializer()) {

test/zutil/net/dns/DnsPacketTest.java

@@ -75,8 +75,7 @@ public class DnsPacketTest {
         packet.getHeader().setDefaultQueryData();
 
         ByteArrayOutputStream buffer = new ByteArrayOutputStream();
-        BinaryStructOutputStream out = new BinaryStructOutputStream(buffer);
+        packet.write(buffer);
-        packet.write(out);
         byte[] data = buffer.toByteArray();
 
         byte[] expected = {
@@ -97,8 +96,7 @@ public class DnsPacketTest {
                 "appletv.local", DnsConstants.TYPE.A, DnsConstants.CLASS.IN));
 
         ByteArrayOutputStream buffer = new ByteArrayOutputStream();
-        BinaryStructOutputStream out = new BinaryStructOutputStream(buffer);
+        packet.write(buffer);
-        packet.write(out);
         byte[] data = buffer.toByteArray();
 
         byte[] expected = {
@@ -155,8 +153,7 @@ public class DnsPacketTest {
                 0xc0, 0x0c, 0x00, 0x04, 0x40, 0x00, 0x00, 0x08 // NSEC
         };
         ByteArrayInputStream buffer = new ByteArrayInputStream(Converter.toBytes(input));
-        BinaryStructInputStream in = new BinaryStructInputStream(buffer);
+        DnsPacket packet = DnsPacket.read(buffer);
-        DnsPacket packet = DnsPacket.read(in);
 
         // Assert Header
         assertTrue("flagQueryResponse", packet.getHeader().flagQueryResponse);
@@ -217,10 +214,9 @@ Domain Name System (query)
         question.clazz = DnsConstants.CLASS.IN;
         packet.addQuestion(question);
 
-        ByteArrayOutputStream buff = new ByteArrayOutputStream();
+        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
-        BinaryStructOutputStream out = new BinaryStructOutputStream(buff);
+        packet.write(buffer);
-        packet.write(out);
+        byte[] data = buffer.toByteArray();
-        byte[] data = buff.toByteArray();
         assertEquals((
                 "241a 01 00 00 01 00 00 00 00 00 00 " +
                 "03 77  77 77 06 67 6f 6f 67 6c 65 03 63 6f 6d 00  0001  0001"
@@ -297,8 +293,7 @@ Domain Name System (response)
                     "c02c  0001  0001  000000e3  0004  42 f9 59 68"   // Answer3
                 ).replace(" ", ""));
         ByteArrayInputStream buffer = new ByteArrayInputStream(input);
-        BinaryStructInputStream in = new BinaryStructInputStream(buffer);
+        DnsPacket packet = DnsPacket.read(buffer);
-        DnsPacket packet = DnsPacket.read(in);
 
         assertEquals("id", 0x241a, packet.getHeader().id);
         assertTrue("flagQueryResponse", packet.getHeader().flagQueryResponse);
@@ -315,19 +310,20 @@ Domain Name System (response)
 
         // Answer
         DnsPacketResource answer = packet.getAnswerRecords().get(0);
-        assertEquals("NAME", "12", answer.name);
+        assertEquals("NAME", "www.google.com", answer.name);
+        //assertEquals("NAME", "<12>", answer.name);
         assertEquals("TYPE", DnsConstants.TYPE.CNAME, answer.type);
         assertEquals("CLASS", DnsConstants.CLASS.IN, answer.clazz);
         assertEquals("TTL", 337977, answer.ttl);
 
         answer = packet.getAnswerRecords().get(1);
-        assertEquals("NAME", "44", answer.name);
+        assertEquals("NAME", "<44>", answer.name);
         assertEquals("TYPE", DnsConstants.TYPE.A, answer.type);
         assertEquals("CLASS", DnsConstants.CLASS.IN, answer.clazz);
         assertEquals("TTL", 227, answer.ttl);
 
         answer = packet.getAnswerRecords().get(2);
-        assertEquals("NAME", "44", answer.name);
+        assertEquals("NAME", "<44>", answer.name);
         assertEquals("TYPE", DnsConstants.TYPE.A, answer.type);
         assertEquals("CLASS", DnsConstants.CLASS.IN, answer.clazz);
         assertEquals("TTL", 227, answer.ttl);
@@ -415,17 +411,16 @@ Multicast Domain Name System (query)
 
         byte[] input = Converter.hexToByte((
                 "00 00 00 00 00 06 00 00 00 00 00 01" + // Header
-                "0f 5f 63 6f 6d 70 61 6e 69 6f 6e 2d 6c 69 6e 6b 04 5f 74 63 70 05 6c 6f 63 61 6c 00 00 0c 00 01" + // Query PTR: _companion-link._tcp.local
+                "0f 5f 63 6f 6d 70 61 6e 69 6f 6e 2d 6c 69 6e 6b 04 5f 74 63 70 05 6c 6f 63 61 6c 00 00 0c 00 01" + // (offset 12) Query PTR: _companion-link._tcp.local
-                "08 5f 68 6f 6d 65 6b 69 74 c0 1c 00 0c 00 01" + // Query PTR: _homekit._tcp.local
+                "08 5f 68 6f 6d 65 6b 69 74 c0 1c 00 0c 00 01" + // (offset 44) Query PTR: _homekit._tcp.local
-                "03 68 61 6c c0 21 00 41 00 01" + // Query Unknown: hal.local
+                "03 68 61 6c c0 21 00 41 00 01" + // (offset 59) Query Unknown: hal.local
-                "c0 3b 00 1c 00 01" + // Query IPv6: hal.local
+                "c0 3b 00 1c 00 01" + // (offset 69) Query IPv6: hal.local
-                "c0 3b 00 01 00 01" + // Query IPv4: hal.local
+                "c0 3b 00 01 00 01" + // (offset 75) Query IPv4: hal.local
                 "0c 5f 73 6c 65 65 70 2d 70 72 6f 78 79 04 5f 75 64 70 c0 21 00 0c 00 01" + // Query PTR: _sleep-proxy._udp.local
                 "00 00 29 05 a0 00 00 11 94 00 12 00 04 00 0e 00 65 7a e6 ba 29 34 00 d6 07 3a f2 2e e7" // Additional records
         ).replace(" ", ""));
         ByteArrayInputStream buffer = new ByteArrayInputStream(input);
-        BinaryStructInputStream in = new BinaryStructInputStream(buffer);
+        DnsPacket packet = DnsPacket.read(buffer);
-        DnsPacket packet = DnsPacket.read(in);
 
         assertEquals("id", 0x00, packet.getHeader().id);
         assertFalse("flagQueryResponse", packet.getHeader().flagQueryResponse);
@@ -441,31 +436,31 @@ Multicast Domain Name System (query)
         assertEquals("clazz", DnsConstants.CLASS.IN, question1.clazz);
 
         DnsPacketQuestion question2 = packet.getQuestions().get(1);
-        //assertEquals("qNAME", "_homekit._tcp.local", question2.name);
+        assertEquals("qNAME", "_homekit._tcp.local", question2.name);
-        assertEquals("qNAME", "_homekit.28", question2.name); // TODO: Fix support for string pointers
+        //assertEquals("qNAME", "_homekit.<28>", question2.name); // TODO: Fix support for string pointers
         assertEquals("type", DnsConstants.TYPE.PTR, question2.type);
         assertEquals("clazz", DnsConstants.CLASS.IN, question2.clazz);
 
         DnsPacketQuestion question3 = packet.getQuestions().get(2);
-        //assertEquals("qNAME", "hal.local", question3.name);
+        assertEquals("qNAME", "hal.local", question3.name);
-        assertEquals("qNAME", "hal.33", question3.name);
+        //assertEquals("qNAME", "hal.<33>", question3.name);
         assertEquals("clazz", DnsConstants.CLASS.IN, question3.clazz);
 
         DnsPacketQuestion question4 = packet.getQuestions().get(3);
-        //assertEquals("qNAME", "hal.local", question4.name);
+        assertEquals("qNAME", "hal.local", question4.name);
-        assertEquals("qNAME", "59", question4.name);
+        //assertEquals("qNAME", "<59>", question4.name);
         assertEquals("type", DnsConstants.TYPE.AAAA, question4.type);
         assertEquals("clazz", DnsConstants.CLASS.IN, question4.clazz);
 
         DnsPacketQuestion question5 = packet.getQuestions().get(4);
-        //assertEquals("qNAME", "hal.local", question5.name);
+        assertEquals("qNAME", "hal.local", question5.name);
-        assertEquals("qNAME", "59", question5.name);
+        //assertEquals("qNAME", "<59>", question5.name);
         assertEquals("type", DnsConstants.TYPE.A, question5.type);
         assertEquals("clazz", DnsConstants.CLASS.IN, question5.clazz);
 
         DnsPacketQuestion question6 = packet.getQuestions().get(5);
-        //assertEquals("qNAME", "_sleep-proxy._udp.local", question6.name);
+        assertEquals("qNAME", "_sleep-proxy._udp.local", question6.name);
-        assertEquals("qNAME", "_sleep-proxy._udp.33", question6.name);
+        //assertEquals("qNAME", "_sleep-proxy._udp.<33>", question6.name);
         assertEquals("type", DnsConstants.TYPE.PTR, question6.type);
         assertEquals("clazz", DnsConstants.CLASS.IN, question6.clazz);
     }