140 lines
2.6 KiB
Rust
140 lines
2.6 KiB
Rust
use std::{
|
|
io::Cursor,
|
|
};
|
|
|
|
use crate::tlv;
|
|
|
|
use thiserror::Error;
|
|
|
|
const MAGIC_NUMBER: [u8; 4] = [0x9a, 0x4a, 0x43, 0x81];
|
|
pub const PACKET_SIZE: usize = 1024;
|
|
|
|
#[derive (Debug)]
|
|
pub enum Message {
|
|
Request {
|
|
idem_id: [u8; 8],
|
|
mac: Option <[u8; 6]>
|
|
},
|
|
Response (Option <[u8; 6]>),
|
|
}
|
|
|
|
#[derive (Debug, Error)]
|
|
pub enum MessageError {
|
|
#[error (transparent)]
|
|
Io (#[from] std::io::Error),
|
|
#[error (transparent)]
|
|
Tlv (#[from] tlv::TlvError),
|
|
#[error ("Unknown type")]
|
|
UnknownType,
|
|
}
|
|
|
|
impl Message {
|
|
pub fn write <W: std::io::Write> (&self, w: &mut W) -> Result <(), std::io::Error>
|
|
{
|
|
w.write_all (&MAGIC_NUMBER)?;
|
|
|
|
match self {
|
|
Self::Request {
|
|
idem_id,
|
|
mac,
|
|
}=> {
|
|
w.write_all (&[1])?;
|
|
w.write_all (&idem_id[..])?;
|
|
Self::write_mac_opt (w, *mac)?;
|
|
},
|
|
Self::Response (mac) => {
|
|
w.write_all (&[2])?;
|
|
Self::write_mac_opt (w, *mac)?;
|
|
},
|
|
}
|
|
|
|
Ok (())
|
|
}
|
|
|
|
fn write_mac_opt <W: std::io::Write> (w: &mut W, mac: Option <[u8; 6]>) -> Result <(), std::io::Error>
|
|
{
|
|
match mac {
|
|
Some (mac) => {
|
|
w.write_all (&[1])?;
|
|
w.write_all (&mac[..])?;
|
|
},
|
|
None => w.write_all (&[0])?,
|
|
}
|
|
Ok (())
|
|
}
|
|
|
|
pub fn to_vec (&self) -> Result <Vec <u8>, tlv::TlvError> {
|
|
let mut cursor = Cursor::new (Vec::with_capacity (PACKET_SIZE));
|
|
self.write (&mut cursor)?;
|
|
Ok (cursor.into_inner ())
|
|
}
|
|
|
|
pub fn read <R: std::io::Read> (r: &mut R) -> Result <Self, MessageError> {
|
|
tlv::Reader::expect (r, &MAGIC_NUMBER)?;
|
|
let t = tlv::Reader::u8 (r)?;
|
|
|
|
Ok (match t {
|
|
1 => {
|
|
let mut idem_id = [0u8; 8];
|
|
r.read_exact (&mut idem_id)?;
|
|
|
|
let mac = Self::read_mac_opt (r)?;
|
|
Self::Request {
|
|
idem_id,
|
|
mac,
|
|
}
|
|
},
|
|
2 => {
|
|
let mac = Self::read_mac_opt (r)?;
|
|
Self::Response (mac)
|
|
},
|
|
_ => return Err (MessageError::UnknownType),
|
|
})
|
|
}
|
|
|
|
fn read_mac_opt <R: std::io::Read> (r: &mut R)
|
|
-> Result <Option <[u8; 6]>, std::io::Error>
|
|
{
|
|
Ok (if tlv::Reader::u8 (r)? == 1 {
|
|
let mut mac = [0u8; 6];
|
|
r.read_exact (&mut mac)?;
|
|
Some (mac)
|
|
}
|
|
else {
|
|
None
|
|
})
|
|
}
|
|
|
|
pub fn from_slice (buf: &[u8]) -> Result <Self, MessageError> {
|
|
let mut cursor = Cursor::new (buf);
|
|
Self::read (&mut cursor)
|
|
}
|
|
}
|
|
|
|
#[cfg (test)]
|
|
mod test {
|
|
use super::*;
|
|
|
|
#[test]
|
|
fn test_1 () {
|
|
for (input, expected) in [
|
|
(
|
|
Message::Response (Some ([0x11, 0x22, 0x33, 0x44, 0x55, 0x66])),
|
|
vec! [
|
|
// Magic number for LookAround packets
|
|
154, 74, 67, 129,
|
|
// Response tag
|
|
2,
|
|
// MAC is Some
|
|
1,
|
|
// MAC
|
|
17, 34, 51, 68, 85, 102,
|
|
],
|
|
),
|
|
].into_iter () {
|
|
let actual = input.to_vec ().unwrap ();
|
|
assert_eq! (actual, expected, "{:?}", input);
|
|
}
|
|
}
|
|
}
|