Commit Graph

22 Commits

Author SHA1 Message Date
秦世成
18e4121952 Pre-decompressed DNS record RData that may contain compression pointers (#9311)
Motivation:

When decoding DnsRecord, if the record contains compression pointers, and not all compression pointers are decompressed, but part of the pointers are decompressed. Then when encoding the record, the compressed pointer will point to the wrong location, resulting in bad label problem.

Modification:

Pre-decompressed record RData that may contain compression pointers.

Result:

Fixes #8962
2019-07-02 19:38:50 +02:00
Thomas Devanneaux
32746c53c1 EDNS Client Subnet is not encoded correctly when source prefix length is not a multiple of 8.
Motivation:
When the ECS source prefix length is not a mutiple of 8, the last byte the address inside the
ECS OPT record is not padded properly.

Modifications:
DefaultDnsRecordEncoder.padWithZeros(...) was modified to add padding from the least
significant bits.

Result:
ECS encoding bug fixed.
2017-12-01 08:14:13 +01:00
Nikolay Fedorovskikh
0692bf1b6a fix the typos 2017-04-20 04:56:09 +02:00
Norman Maurer
fbf0e5f4dd Prefer JDK ThreadLocalRandom implementation over ours.
Motivation:

We have our own ThreadLocalRandom implementation to support older JDKs . That said we should prefer the JDK provided when running on JDK >= 7

Modification:

Using ThreadLocalRandom implementation of the JDK when possible.

Result:

Make use of JDK implementations when possible.
2017-02-16 15:44:00 -08:00
Tim Brooks
3344cd21ac Wrap operations requiring SocketPermission with doPrivileged blocks
Motivation:

Currently Netty does not wrap socket connect, bind, or accept
operations in doPrivileged blocks. Nor does it wrap cases where a dns
lookup might happen.

This prevents an application utilizing the SecurityManager from
isolating SocketPermissions to Netty.

Modifications:

I have introduced a class (SocketUtils) that wraps operations
requiring SocketPermissions in doPrivileged blocks.

Result:

A user of Netty can grant SocketPermissions explicitly to the Netty
jar, without granting it to the rest of their application.
2017-01-19 21:12:52 +01:00
Scott Mitchell
cfa5b85075 DefaultDnsRecordDecoder compression and index decode bug
Motivation:
8cf90f0512 switch a duplicate opreration to a slice operation. Typically this would be fine but DNS supports a compression (https://www.ietf.org/rfc/rfc1035 4.1.4. Message compression) where the payload contains absolute indexes which refer back to previously referenced content. Using a slice will break the ability for the indexes in the payload to correctly self reference to the index of the originial payload, and thus decoding may fail.

Modifications:
- Use duplicate instead of slice so DNS message compression and index references are preserved.

Result:
Fixes DefaultDnsRecordDecoder regression
2016-10-20 09:00:55 -07:00
Norman Maurer
dfa3bbbf00 Add support for Client Subnet in DNS Queries (RFC7871)
Motivation:

RFC7871 defines an extension which allows to request responses for a given subset.

Modifications:

- Add DnsOptPseudoRrRecord which can act as base class for extensions based on EDNS(0) as defined in RFC6891
- Add DnsOptEcsRecord to support the Client Subnet in DNS Queries extension
- Add tests

Result:

Client Subnet in DNS Queries extension is now supported.
2016-09-06 07:16:57 +02:00
Norman Maurer
8cf90f0512 [#5760] Do not change writerIndex when decode DnsPtrRecord
Motivation:

We need to not change the original writerIndex when decode a DnsPtrRecord as otherwise we will not be able to decode other records that follow it.

Modifications:

Slice the data out and so not increase the writerIndex.

Result:

No more problems when decoding.
2016-09-01 08:26:52 +02:00
Trustin Lee
4b38b72a0d Fix incorrect name encoding/decoding in DNS records
Motivation:

- The decoded name should always end with a dot (.), but we currently
  strip it, which is incorrect.
  - (O) 0 -> "."
  - (X) 0 -> ""
  - (O) 5 netty 2 io 0 -> "netty.io."
  - (X) 5 netty 2 io 0 -> "netty.io"
- The encoded name should end with a null-label, which is a label whose
  length is 0, but we currently append an extra NUL, causing FORMERR(1)
  on a strict DNS server:
  - (O) . -> 0
  - (X) . -> 0 0
  - (O) netty.io. -> 5 netty 2 io 0
  - (X) netty.io. -> 5 netty 2 io 0 0

Modifications:

- Make sure to append '.' when decoding a name.
- Improve index checks so that the decoder can raise
  CorruptFrameException instead of IIOBE
- Do not encode extra NUL
- Add more tests

Result:

Robustness and correctness
2016-04-01 22:18:33 +02:00
Norman Maurer
6bf7e24389 [#5014] Correctly encode / decode zero-length names when encoding DnsRecords.
Motivation:

Zero-length names needs to be "prefixed" by the length as well when encoded into a ByteBuf. Also some servers not correctly prefix these so we should ensure we can workaround this and even decode in such case.

Modifications:

- Always encode the length of the name into the ByteBuf even if its zero-length.
- If there are no readable bytes for the name just asume its an empty name to workaround dns servers that not fully respect the RFC.

Result:

Correctly encode zero-length names and be able to decode empty names even when the rfc is not strictly followed.
2016-03-24 13:51:04 +01:00
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
Scott Mitchell
cf171ff525 maxBytesPerRead channel configuration
Motiviation:
The current read loops don't fascilitate reading a maximum amount of bytes. This capability is useful to have more fine grain control over how much data is injested.

Modifications:
- Add a setMaxBytesPerRead(int) and getMaxBytesPerRead() to ChannelConfig
- Add a setMaxBytesPerIndividualRead(int) and getMaxBytesPerIndividualRead to ChannelConfig
- Add methods to RecvByteBufAllocator so that a pluggable scheme can be used to control the behavior of the read loop.
- Modify read loop for all transport types to respect the new RecvByteBufAllocator API

Result:
The ability to control how many bytes are read for each read operation/loop, and a more extensible read loop.
2015-08-05 23:59:54 -07:00
Trustin Lee
9d70cf33c2 Fix a test failure in DnsQueryTest 2015-05-01 12:03:44 +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
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
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
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