A DNS protocol parser. Given bytes and a [sawp::parser::Direction], it will attempt to parse the bytes and return a [Message]. The parser will inform the caller about what went wrong if no message is returned (see [sawp::parser::Parse] for details on possible return types).

The following protocol references were used to create this module:

RFC1035 RFC1123 RFC2065 RFC2505 RFC2535 RFC2845 RFC2930 RFC3655 RFC4255 RFC4408 RFC4635 RFC5001 RFC6742 RFC6891 RFC6975 RFC7314 RFC7828 RFC7830 RFC7871 RFC7873 RFC7901 RFC8145 RFC8764 RFC8914 Cisco - Identifying DNS Traffic Draft DNSOP Zone Digest Draft DNSOP SVCB Draft EDNS Tags Eastlake Kitchen Sink NIMROD DNS Wijngaard's DNS Parameters

Example

use sawp::parser::{Direction, Parse};
use sawp::error::Error;
use sawp::error::ErrorKind;
use sawp_dns::{Dns, Message};

fn parse_bytes(input: &[u8]) -> std::result::Result<&[u8], Error> {
let dns = Dns {};
let mut bytes = input;
while bytes.len() > 0 {
// If we know that this is a request or response, change the Direction
// for a more accurate parsing
match dns.parse(bytes, Direction::Unknown) {
// The parser succeeded and returned the remaining bytes and the parsed DNS message
Ok((rest, Some(message))) => {
println!("Dns message: {:?}", message);
bytes = rest;
}
// The parser recognized that this might be DNS and made some progress,
// but more bytes are needed
Ok((rest, None)) => return Ok(rest),
// The parser was unable to determine whether this was DNS or not and more
// bytes are needed
Err(Error { kind: ErrorKind::Incomplete(_) }) => return Ok(bytes),
// The parser determined that this was not DNS
Err(e) => return Err(e)
}
}

Ok(bytes)
}