"WireParseException: bad label type" when parsing Message from ByteBuffer #213
Description
Hi
I'm running into WireParseException when parsing most responses from a specific DNS server over TCP. There seems to be an issue with the way in which dnsjava parses messages from ByteBuffers. Specifically, I believe that dnsjava doesn't take into account original position of the ByteBuffer when it encounters label compression.
The following code demonstrates the issue:
byte[] arr = Base64.getDecoder().decode("EEuBgAABAAEABAAIA3d3dwZnb29nbGUDY29tAAABAAHADAABAAEAAAAaAASO+rokwBAAAgABAAFHCwAGA25zMcAQwBAAAgABAAFHCwAGA25zNMAQwBAAAgABAAFHCwAGA25zM8AQwBAAAgABAAFHCwAGA25zMsAQwDwAAQABAADObwAE2O8gCsByAAEAAQABrVEABNjvIgrAYAABAAEAAVqZAATY7yQKwE4AAQABAAK9RQAE2O8mCsA8ABwAAQAD4a0AECABSGBIAgAyAAAAAAAAAArAcgAcAAEAAtDgABAgAUhgSAIANAAAAAAAAAAKwGAAHAABAACSagAQIAFIYEgCADYAAAAAAAAACsBOABwAAQAErVoAECABSGBIAgA4AAAAAAAAAAo=");
ByteBuffer wrap = ByteBuffer.allocate(arr.length+2);
wrap.putShort((short) arr.length); //prepend length, like when reading a response from a TCP channel
wrap.put(arr);
wrap.flip();
wrap.getShort(); //read the prepended length
System.out.println(new Message(wrap)); //Exception in thread "main" org.xbill.DNS.WireParseException: bad label type
Without prepending (and reading) the length, the same message is parsed without any issues:
byte[] arr = Base64.getDecoder().decode("EEuBgAABAAEABAAIA3d3dwZnb29nbGUDY29tAAABAAHADAABAAEAAAAaAASO+rokwBAAAgABAAFHCwAGA25zMcAQwBAAAgABAAFHCwAGA25zNMAQwBAAAgABAAFHCwAGA25zM8AQwBAAAgABAAFHCwAGA25zMsAQwDwAAQABAADObwAE2O8gCsByAAEAAQABrVEABNjvIgrAYAABAAEAAVqZAATY7yQKwE4AAQABAAK9RQAE2O8mCsA8ABwAAQAD4a0AECABSGBIAgAyAAAAAAAAAArAcgAcAAEAAtDgABAgAUhgSAIANAAAAAAAAAAKwGAAHAABAACSagAQIAFIYEgCADYAAAAAAAAACsBOABwAAQAErVoAECABSGBIAgA4AAAAAAAAAAo=");
ByteBuffer wrap = ByteBuffer.allocate(arr.length);
wrap.put(arr);
wrap.flip();
System.out.println(new Message(wrap));
Output:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4171
;; flags: qr rd ra ; qd: 1 an: 1 au: 4 ad: 8
;; QUESTIONS:
;; www.google.com., type = A, class = IN
;; ANSWERS:
www.google.com. 26 IN A 142.250.186.36
;; AUTHORITY RECORDS:
google.com. 83723 IN NS ns1.google.com.
google.com. 83723 IN NS ns4.google.com.
google.com. 83723 IN NS ns3.google.com.
google.com. 83723 IN NS ns2.google.com.
;; ADDITIONAL RECORDS:
ns1.google.com. 52847 IN A 216.239.32.10
ns2.google.com. 109905 IN A 216.239.34.10
ns3.google.com. 88729 IN A 216.239.36.10
ns4.google.com. 179525 IN A 216.239.38.10
ns1.google.com. 254381 IN AAAA 2001:4860:4802:32:0:0:0:a
ns2.google.com. 184544 IN AAAA 2001:4860:4802:34:0:0:0:a
ns3.google.com. 37482 IN AAAA 2001:4860:4802:36:0:0:0:a
ns4.google.com. 306522 IN AAAA 2001:4860:4802:38:0:0:0:a
;; Message size: 296 bytes