detect_dns_packet 0.1.0

mod dns_header;
mod dns_queries;
mod utils;

use dns_header::DnsHeader;
use dns_queries::DnsQueries;
use std::{error::Error, fmt};
use utils::dns_class::DnsClass;
use utils::dns_types::DnsType;

#[derive(Debug)]
pub struct DnsPacket {
    pub header: DnsHeader,
    pub queries: DnsQueries,
    pub answers: Option<Vec<Answer>>, // List of answer records
    pub authorities: Option<Vec<AuthoritativeNameServer>>, // List of authority records
    pub additionals: Option<Vec<AdditionalRecord>>, // List of additional records
}

impl TryFrom<&[u8]> for DnsPacket {
    type Error = Box<dyn Error>;

    fn try_from(bytes: &[u8]) -> Result<Self, Self::Error> {
        let header = DnsHeader::try_from(bytes)?;
        let queries = DnsQueries::from_bytes(&bytes[12..], header.counts[0])?;
        let answers = None;
        let authorities = None;
        let additionals = None;

        Ok(DnsPacket {
            header,
            queries,
            answers,
            authorities,
            additionals,
        })
    }
}

// more can be a list of this possible struct (those strcut may on may not be on the liste: "more"):
#[derive(Debug)]
pub struct Answer {
    name: String,           // Domain name
    answer_type: DnsType,   // Type of record (e.g., A, AAAA, MX, etc.)
    answer_class: DnsClass, // Class of record (typically IN for Internet)
    ttl: u32,               // Time to live
    data_length: u16,       // Length of the data
    address: Vec<u8>,       // Address or other data (variable length)
}

impl fmt::Display for Answer {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "Answer {{ name: {}, answer_type: {}, answer_class: {}, ttl: {}, data_length: {}, address: {:?} }}",
            self.name, self.answer_type, self.answer_class, self.ttl, self.data_length, self.address
        )
    }
}

#[derive(Debug)]
pub struct AuthoritativeNameServer {
    name: String,           // Domain name
    answer_type: DnsType,   // Type of record
    answer_class: DnsClass, // Class of record
    ttl: u32,               // Time to live
    data_length: u16,       // Length of the data
    address: Vec<u8>,       // Address or other data (variable length)
}

impl fmt::Display for AuthoritativeNameServer {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "AuthoritativeNameServer {{ name: {}, answer_type: {}, answer_class: {}, ttl: {}, data_length: {}, address: {:?} }}",
            self.name, self.answer_type, self.answer_class, self.ttl, self.data_length, self.address
        )
    }
}

#[derive(Debug)]
pub struct AdditionalRecord {
    name: String,           // Domain name
    answer_type: DnsType,   // Type of record
    answer_class: DnsClass, // Class of record
    ttl: u32,               // Time to live
    data_length: u16,       // Length of the data
    address: Vec<u8>,       // Address or other data (variable length)
}

impl fmt::Display for AdditionalRecord {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "AdditionalRecord {{ name: {}, answer_type: {}, answer_class: {}, ttl: {}, data_length: {}, address: {:?} }}",
            self.name, self.answer_type, self.answer_class, self.ttl, self.data_length, self.address
        )
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_dns_packet_parsing() {
        // Example DNS packet data
        let data = hex::decode("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").expect("Invalid hex string");

        match DnsPacket::try_from(data.as_slice()) {
            Ok(packet) => {
                println!("{:?}", packet);
                assert_eq!(packet.header.transaction_id, 0x002b);
                assert_eq!(packet.header.flags, 0x8180);
                assert_eq!(packet.header.counts[0], 1);
                assert_eq!(packet.header.counts[1], 15);
                assert_eq!(packet.header.counts[2], 6);
                assert_eq!(packet.header.counts[3], 2);
            }
            Err(e) => panic!("Error parsing DNS packet: {}", e),
        }
    }

    #[test]
    fn test_dns_packet_parsing_return_error() {
        // Example non-DNS packet data
        let data = hex::decode("1a030aee00001bf7000014ec51ae80b7c502034c8d0e66cbc50204ecec42ee92c50204ebcf4959e6c50204ebcf4c6e6d").expect("Invalid hex string");

        match DnsPacket::try_from(data.as_slice()) {
            Ok(_) => panic!("Expected error, but parsing succeeded"),
            Err(e) => assert!(
                e.to_string().contains("Invalid Z field, must be 0."),
                "Unexpected error: {}",
                e
            ),
        }
    }
}