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#![cfg_attr(not(feature = "tls"), allow(unused))]
use std::net::TcpStream;
use std::io::Write;
use log::*;
use dns::{Request, Response};
use super::{Transport, Error, TcpTransport};
use super::tls_stream::TlsStream;
/// The **TLS transport**, which sends DNS wire data using TCP through an
/// encrypted TLS connection.
pub struct TlsTransport {
addr: String,
}
impl TlsTransport {
/// Creates a new TLS transport that connects to the given host.
pub fn new(addr: String) -> Self {
Self { addr }
}
}
impl Transport for TlsTransport {
#[cfg(feature = "with_tls")]
fn send(&self, request: &Request) -> Result<Response, Error> {
info!("Opening TLS socket");
let domain = self.sni_domain();
info!("Connecting using domain {:?}", domain);
let mut stream =
if self.addr.contains(':') {
let mut parts = self.addr.split(":");
let domain = parts.nth(0).unwrap();
let port = parts.last().unwrap().parse::<u16>().expect("Invalid port number");
Self::stream(domain, port)?
}
else {
Self::stream(&*self.addr, 853)?
};
debug!("Connected");
// The message is prepended with the length when sent over TCP,
// so the server knows how long it is (RFC 1035 §4.2.2)
let mut bytes_to_send = request.to_bytes().expect("failed to serialise request");
TcpTransport::prefix_with_length(&mut bytes_to_send);
info!("Sending {} bytes of data to {} over TLS", bytes_to_send.len(), self.addr);
stream.write_all(&bytes_to_send)?;
debug!("Wrote all bytes");
let read_bytes = TcpTransport::length_prefixed_read(&mut stream)?;
let response = Response::from_bytes(&read_bytes)?;
Ok(response)
}
#[cfg(not(feature = "with_tls"))]
fn send(&self, request: &Request) -> Result<Response, Error> {
unreachable!("TLS feature disabled")
}
}
impl TlsTransport {
fn sni_domain(&self) -> &str {
if let Some(colon_index) = self.addr.find(':') {
&self.addr[.. colon_index]
}
else {
&self.addr[..]
}
}
}
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