First DNS compile. Took DNS code from https://github.com/EmilHernvall/hermes.

src/dns/netutil.rs

@@ -0,0 +1,19 @@
+use std::io::{Read, Result, Write};
+use std::net::TcpStream;
+
+pub fn read_packet_length(stream: &mut TcpStream) -> Result<u16> {
+    let mut len_buffer = [0; 2];
+    stream.read(&mut len_buffer)?;
+
+    Ok(((len_buffer[0] as u16) << 8) | (len_buffer[1] as u16))
+}
+
+pub fn write_packet_length(stream: &mut TcpStream, len: usize) -> Result<()> {
+    let mut len_buffer = [0; 2];
+    len_buffer[0] = (len >> 8) as u8;
+    len_buffer[1] = (len & 0xFF) as u8;
+
+    stream.write(&len_buffer)?;
+
+    Ok(())
+}