Commit Graph

17 Commits

Author SHA1 Message Date
Norman Maurer
48506f5b05 [#4993] Correctly handle trailing dot in DNS requests and responses for the hostname.
Motivation:

We need to handle the trailing dot in the correct manner when creating DNS questions and responses.

Modifications:

- Add a trailing dot if not given to the hostname when construct a AbstractDnsRecord (this is the same as dig does).

Result:

Correctly handle trailing dots.
2016-03-22 12:30:46 +01:00
Norman Maurer
c3c1b4a6d2 [#4937] [#4935] Correctly valid domain name length and convert to ASCII.
Motivation:

Domain name labels must be converted to ASCII and not be longer then 63 chars.

Modifications:

Correctly convert to ASCII which also will enforce the 63 chars length.

Result:

Correctly guard against invalid input.
2016-03-16 11:55:19 +01:00
Fabian Lange
58c63b7888 Add support for directly decoding/encoding DNS PTR Records
Motivation:

The current implementation will provide a DnsRawRecord, which, while
containing the host name it resolves to, would require the user to
decode the name using the decode method currently private to
DefaultDnsRecordDecoder, which in fact means copying it.

Modifications:

Introduce DnsPtrRecord, which is a specialization of DnsRecord which
provides a decoded host name.

Result:

PTR Records are much easier to work with, as the name is decoded already.
2016-03-08 14:59:46 +01:00
Yeti Sno
b9ae48589b Make codec-dns can support build a dns server, reply answer from client.
Motivation:

codec-dns has great function to solve dns packet, but only make a query, not answer query from other client.

i make a change of add two classes to fill last pieces of map, finish the server function.

Modifications:

in this change, add two classes of DatagramDnsQueryDecoder and DatagramDnsResponseEncoder to handle client query, reply answer.

Result:

nothing code change after this commit, except two new classes.
2016-01-18 16:41:44 +09:00
Trustin Lee
fdfe3149ba Provide more control over DnsNameResolver.query() / Add NameResolver.resolveAll()
Related issues:
- #3971
- #3973
- #3976
- #4035

Motivation:

1. Previously, DnsNameResolver.query() retried the request query by its
own. It prevents a user from deciding when to retry or stop. It is also
impossible to get the response object whose code is not NOERROR.

2. NameResolver does not have an operation that resolves a host name
into multiple addresses, like InetAddress.getAllByName()

Modifications:

- Changes related with DnsNameResolver.query()
  - Make query() not retry
    - Move the retry logic to DnsNameResolver.resolve() instead.
  - Make query() fail the promise only when I/O error occurred or it
    failed to get a response
  - Add DnsNameResolverException and use it when query() fails so that
    the resolver can give more information about the failure
  - query() does not cache anymore.

- Changes related with NameResolver.resolveAll()
  - Add NameResolver.resolveAll()
  - Add SimpleNameResolver.doResolveAll()

- Changes related with DnsNameResolver.resolve() and resolveAll()
  - Make DnsNameResolveContext abstract so that DnsNameResolver can
    decide to get single or multiple addresses from it
  - Re-implement cache so that the cache works for resolve() and
    resolveAll()
  - Add 'traceEnabled' property to enable/disable trace information

- Miscellaneous changes
  - Use ObjectUtil.checkNotNull() wherever possible
  - Add InternetProtocolFamily.addressType() to remove repetitive
    switch-case blocks in DnsNameResolver(Context)
  - Do not raise an exception when decoding a truncated DNS response

Result:

- Full control over query()
- A user can now retrieve all addresses via (Dns)NameResolver.resolveAll()
- DNS cache works only for resolve() and resolveAll() now.
2015-08-18 17:40:13 +09:00
Trustin Lee
5e0ee6c095 Fix missing ResourceLeak.close() in AbstractDnsMessage
Motivation:

ResourceLeak.close() must be called when a reference-counted resource is
deallocated, but AbstractDnsMessage.deallocate() forgot to call it.

Modifications:

Call ResourceLeak.close() for the tracked AbstractDnsMessage instances

Result:

Fix the false resource leak warnings
2015-05-04 12:05:59 +09:00
Trustin Lee
63a02fc04e Revamp DNS codec
Motivation:

There are various known issues in netty-codec-dns:

- Message types are not interfaces, which can make it difficult for a
  user to implement his/her own message implementation.
- Some class names and field names do not match with the terms in the
  RFC.
- The support for decoding a DNS record was limited. A user had to
  encode and decode by him/herself.
- The separation of DnsHeader from DnsMessage was unnecessary, although
  it is fine conceptually.
- Buffer leak caused by DnsMessage was difficult to analyze, because the
  leak detector tracks down the underlying ByteBuf rather than the
  DnsMessage itself.
- DnsMessage assumes DNS-over-UDP.
- To send an EDNS message, a user have to create a new DNS record class
  instance unnecessarily.

Modifications:

- Make all message types interfaces and add default implementations
- Rename some classes, properties, and constants to match the RFCs
  - DnsResource -> DnsRecord
  - DnsType -> DnsRecordType
  - and many more
- Remove DnsClass and use an integer to support EDNS better
- Add DnsRecordEncoder/DnsRecordDecoder and their default
  implementations
  - DnsRecord does not require RDATA to be ByteBuf anymore.
  - Add DnsRawRecord as the catch-all record type
- Merge DnsHeader into DnsMessage
- Make ResourceLeakDetector track AbstractDnsMessage
- Remove DnsMessage.sender/recipient properties
  - Wrap DnsMessage with AddressedEnvelope
  - Add DatagramDnsQuest and DatagramDnsResponse for ease of use
  - Rename DnsQueryEncoder to DatagramDnsQueryEncoder
  - Rename DnsResponseDecoder to DatagramDnsResponseDecoder
- Miscellaneous changes
  - Add StringUtil.TAB

Result:

- Cleaner APi
- Can support DNS-over-TCP more easily in the future
- Reduced memory footprint in the default DnsQuery/Response
  implementations
- Better leak tracking for DnsMessages
- Possibility to introduce new DnsRecord types in the future and provide
  full record encoder/decoder implementation.
- No unnecessary instantiation for an EDNS pseudo resource record
2015-05-01 11:33:16 +09:00
Trustin Lee
ab2e80fbb1 Add EDNS support to DnsQueryEncoder
Motivation:

DnsQueryEncoder does not encode the 'additional resources' section at all, which contains the pseudo-RR as defined in RFC 2671.

Modifications:

- Modify DnsQueryEncoder to encode the additional resources
- Fix a bug in DnsQueryEncoder where an empty name is encoded incorrectly

Result:

A user can send an EDNS query.
2014-10-16 17:05:08 +09:00
Norman Maurer
74dd295e59 Fix buffer leaks in DnsResponseDecoder and DnsResponseDecoderTest
Motivation:

There were two buffer leaks in the codec-dns.

Modifications:

- Fix buffer leak in DnsResponseTest.readResponseTest()
- Correctly release DnsResources on Exception

Result:

No more buffer leaks in the codec-dns module.
2014-08-04 14:06:45 +02:00
Norman Maurer
e09d2f32fb [#2708] DnsResource.duplicate() should return DnsResource and not ByteBufHolder
Motivation:

DnsResource.duplicate() should return DnsResource and not ByteBufHolder

Modifications:

Change return type from ByteBufHolder to DnsResource

Result:

No need to cast to the correct type when using duplicate()
2014-07-28 04:26:09 -07:00
Trustin Lee
4bde044957 Overall cleanup of codec-dns
Related issue: #2688

- DnsClass and DnsType
  - Make DnsClass and DnsType implement Comparable
  - Optimize the message generation of IllegalArgumentException,
    by pre-populating the list of the expected parameters
  - Move the static methods up
  - Relax the validation rule of DnsClass so that a user can define a
    CLASS which is not listed in the RFC 1035
  - valueOf(int) does not throw IllegalArgumentException anymore as long
    as the specified value is an unsigned short.
  - Rename create() and forName() to valueOf() so that they look like a
    real enum
  - Rename type() and clazz() to intValue() so that they conform to our
    naming convention
- Add missing null checks in DnsEntry
2014-07-23 14:40:52 -07:00
Tim Boudreau
9734170b7d Use value types for class and type in DNS entries to make them immune to parameter order bugs
Motivation:

DNS class and type were represented as integers rather than an enum or a
similar dedicated value type.  This can be a potential source of a
parameter order bug which might be difficult to track down.

Modifications:

Add DnsClass and DnsType to replace integer parameters

Result:

Type safety and less error-proneness
2014-07-23 14:40:52 -07:00
Trustin Lee
923a0e71ac Raise a meaningful exception instead of NPE
Motivation:

When decoding the NAME field in a DNS Resource Record, DnsResponseDecoder
can raise a NullPointerException if the NAME field contains a loop.

Modification:

Instead of raising an NPE, raise CorruptedFrameException so that the
exception itself has meaning.

Result:

Less confusing when a malformed DNS RR is received
2014-07-21 16:51:38 -07:00
Trustin Lee
ae9963a40c Fix NPE while decoding authority section of a DNS response
Motivation:

NullPointerException is raised when a DNS response conrains a resource
record whose NAME is empty, which is the case for the authority section.

Modification:

Allow an empty name for DnsEntry. Only disallow an empty name for
DnsQuestion.

Result:

Fixes #2686
2014-07-21 16:40:26 -07:00
Adam
702ebbc19b Don't spin from malformed dns packets containing loops
Motivation:

DNS packets that contain pointers in a loop will cause
DnsResponseDecoder.readName() to infinite loop.

Modifications:

Fixed DnsResponseDecoder.readName() to detect when packets have loops
and return null instead.

Result:

It is no longer possible to cause Netty to infinite loop by sending it malformed
DNS packets with a loop.
2014-07-20 14:09:16 +02:00
Trustin Lee
d0912f2709 Fix most inspector warnings
Motivation:

It's good to minimize potentially broken windows.

Modifications:

Fix most inspector warnings from our profile
Update IntObjectHashMap

Result:

Cleaner code
2014-07-02 19:55:07 +09:00
Norman Maurer
e3c76ec106 DNS codec for Netty which is based on the work of [#1622].
Motivation:
As part of GSOC 2013 we had @mbakkar working on a DNS codec but did not integrate it yet as it needs some cleanup. This commit is based on @mbakkar's work and provide the codec for DNS.

Modifications:
Add DNS codec

Result:
Reusable DNS codec will be included in netty.

This PR also includes a AsynchronousDnsResolver which allows to resolve DNS entries in a non blocking way by make use
of the dns codec and netty transport itself.
2014-06-10 09:57:06 +02:00