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|
use std::net::IpAddr;
use self::{
buffer::PacketBuffer, header::DnsHeader, query::QueryType, question::DnsQuestion,
record::DnsRecord,
};
use crate::Result;
pub mod buffer;
pub mod header;
pub mod query;
pub mod question;
pub mod record;
pub mod result;
#[derive(Clone, Debug)]
pub struct Packet {
pub header: DnsHeader,
pub questions: Vec<DnsQuestion>,
pub answers: Vec<DnsRecord>,
pub authorities: Vec<DnsRecord>,
pub resources: Vec<DnsRecord>,
}
impl Packet {
pub fn new() -> Self {
Self {
header: DnsHeader::new(),
questions: Vec::new(),
answers: Vec::new(),
authorities: Vec::new(),
resources: Vec::new(),
}
}
pub fn from_buffer(buffer: &mut PacketBuffer) -> Result<Self> {
let mut result = Self::new();
result.header.read(buffer)?;
for _ in 0..result.header.questions {
let mut question = DnsQuestion::new("".to_string(), QueryType::UNKNOWN(0));
question.read(buffer)?;
result.questions.push(question);
}
for _ in 0..result.header.answers {
let rec = DnsRecord::read(buffer)?;
result.answers.push(rec);
}
for _ in 0..result.header.authoritative_entries {
let rec = DnsRecord::read(buffer)?;
result.authorities.push(rec);
}
for _ in 0..result.header.resource_entries {
let rec = DnsRecord::read(buffer)?;
result.resources.push(rec);
}
Ok(result)
}
pub fn write(&mut self, buffer: &mut PacketBuffer) -> Result<()> {
self.header.questions = self.questions.len() as u16;
self.header.answers = self.answers.len() as u16;
self.header.authoritative_entries = self.authorities.len() as u16;
self.header.resource_entries = self.resources.len() as u16;
self.header.write(buffer)?;
for question in &self.questions {
question.write(buffer)?;
}
for rec in &self.answers {
rec.write(buffer)?;
}
for rec in &self.authorities {
rec.write(buffer)?;
}
for rec in &self.resources {
rec.write(buffer)?;
}
Ok(())
}
pub fn get_random_a(&self) -> Option<IpAddr> {
self.answers
.iter()
.filter_map(|record| match record {
DnsRecord::A { addr, .. } => Some(IpAddr::V4(*addr)),
DnsRecord::AAAA { addr, .. } => Some(IpAddr::V6(*addr)),
_ => None,
})
.next()
}
fn get_ns<'a>(&'a self, qname: &'a str) -> impl Iterator<Item = (&'a str, &'a str)> {
self.authorities
.iter()
.filter_map(|record| match record {
DnsRecord::NS { domain, host, .. } => Some((domain.as_str(), host.as_str())),
_ => None,
})
.filter(move |(domain, _)| qname.ends_with(*domain))
}
pub fn get_resolved_ns(&self, qname: &str) -> Option<IpAddr> {
self.get_ns(qname)
.flat_map(|(_, host)| {
self.resources
.iter()
.filter_map(move |record| match record {
DnsRecord::A { domain, addr, .. } if domain == host => {
Some(IpAddr::V4(*addr))
}
DnsRecord::AAAA { domain, addr, .. } if domain == host => {
Some(IpAddr::V6(*addr))
}
_ => None,
})
})
.next()
}
pub fn get_unresolved_ns<'a>(&'a self, qname: &'a str) -> Option<&'a str> {
self.get_ns(qname).map(|(_, host)| host).next()
}
}
|
