Pure Rust implementation to work with DNS packets
You can parse or write a DNS packet by using [Packet] or [PacketBuf] structs
Packet holds references for the original data and it is more suitable for situations where you need to manipulate the packet before generating the final bytes buffer
```rust use simpledns::*; use simpledns::rdata::*; let question = Question::new(Name::newunchecked("srv.udp.local"), QTYPE::TXT, QCLASS::IN, false); let resource = ResourceRecord::new(Name::newunchecked("srv.udp.local"), CLASS::IN, 10, RData::A(A { address: 10 }));
let mut packet = Packet::newquery(1, false); packet.questions.push(question); packet.additionalrecords.push(resource);
let bytes = packet.buildbytesvec(); assert!(bytes.is_ok());
// Same as above, but Names are compressed
let bytes = packet.buildbytesveccompressed();
assert!(bytes.isok());
``
It doesn't matter what order the resources are added, the packet will be built only whenbuildbytesvec` is called
To parse the contents of a buffer into a packet, you need call call [Packet::parse] ```rust use simple_dns::Packet;
let bytes = b"\x00\x03\x01\x00\x00\x01\x00\x00\x00\x00\x00\x00\x06\x67\x6f\x6f\x67\x6c\x65\x03\x63\x6f\x6d\x00\x00\x01\x00\x01"; let packet = Packet::parse(&bytes[..]); assert!(packet.is_ok()); ```
PacketBuf holds an internal buffer that is populated right when a resource is added.
It DOES matter the order in which the resources are added
```rust
let question = Question::new(Name::newunchecked("srv.udp.local"), QTYPE::TXT, QCLASS::IN, false); let resource = ResourceRecord::new(Name::newunchecked("srv.udp.local"), CLASS::IN, 10, RData::A(A { address: 10 }));
let mut packet = PacketBuf::new(PacketHeader::newquery(1, false), true); assert!(packet.addanswer(&resource).isok()); assert!(packet.addquestion(&question).is_err()); //This will fail, since an answer is already added ```
It is possible to create a PacketBuf from a buffer by calling [PacketBuf::from], but be aware that this will clone the contents from the buffer
The Packet structure provides parsing e building of a DNS packet, it aims to be fully compliant with the RFCs bellow: - RFC 1034 - RFC 1035 - RFC 6762 - RFC 2782 - RFC 3596
Other Resource Records defined by other RFCs that are not in this list will be implemented over time