ws2can 0.1.0

A websocket to socketcan convertor. It receives a json CAN frame and send it via socketcan to the device
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134

use std::net::SocketAddr;
use std::result::Result::Ok;

use futures_util::{future, pin_mut, SinkExt, StreamExt};
use log::*;
use tokio::net::{TcpListener, TcpStream};
use tokio::sync;
use tokio_socketcan::{CANFrame, CANSocket};
use tokio_tungstenite::tungstenite::Message;

use can::CanFrame;

mod can;

type Sender<T = CANFrame> = sync::mpsc::Sender<T>;
type Receiver<T = CANFrame> = sync::mpsc::Receiver<T>;

async fn handle_ws_connection(
    raw_stream: TcpStream,
    addr: SocketAddr,
    in_tx: &Sender,
    mut out_rx: Receiver,
) {
    info!("Incoming TCP connection from: {}", addr);

    let stream = tokio_tungstenite::accept_async(raw_stream)
        .await
        .expect("Error during the websocket handshake occurred");
    info!("WebSocket connection established: {}", addr);

    let (mut outgoing, incoming) = stream.split();

    let ws_receiver = incoming.for_each(|msg| async move {
        match msg {
            Ok(msg) => {
                if let Ok(msg) = msg.to_text() {
                    if let Ok(can_frame) = CanFrame::from_json(msg) {
                        info!("WS(in): {}", msg);
                        if let Err(e) = in_tx.clone().send(can_frame.to_linux_frame()).await {
                            error!(
                                "Error occurred while sending frame from WS to CAN channel: {:?}",
                                e
                            );
                        }
                    } else {
                        error!("Couldn't parse received can frame json: {}", msg);
                    }
                }
            }
            Err(e) => {
                error!("Error occurred while WS receiving a message: {:?}", e);
            }
        }
    });

    let ws_transmitter = tokio::spawn(async move {
        while let Some(f) = out_rx.recv().await {
            let j = CanFrame::from_linux_frame(f).to_json();
            info!("WS(out): {}", j);
            let msg = Message::Text(j);
            if let Err(e) = outgoing.send(msg).await {
                error!("Error occurred while sending WS message: {:?}", e);
            }
        }
    });

    pin_mut!(ws_receiver, ws_transmitter);
    future::select(ws_receiver, ws_transmitter).await;
    info!("WS disconnected!");
}

async fn start_ws(addr: &str, in_tx: &Sender, out_rx: Receiver) {
    let listener = TcpListener::bind(addr)
        .await
        .expect(&format!("Can't bind websocket address {}", addr));

    info!("Listening on: {}", addr);

    if let Ok((stream, addr)) = listener.accept().await {
        handle_ws_connection(stream, addr, &in_tx, out_rx).await;
    }
}

async fn start_can(can_addr: &str, out_tx: &Sender, mut in_rx: Receiver) {
    let can_socket = CANSocket::open(&can_addr).unwrap();
    let (mut outgoing, incoming) = can_socket.split();

    let can_receiver = incoming.for_each(|msg| async move {
        match msg {
            Ok(msg) => {
                info!("CAN(in): {:?}", msg);
                if let Err(e) = out_tx.clone().send(msg).await {
                    error!(
                        "Error occurred while sending frame from CAN to WS channel: {:?}",
                        e
                    );
                }
            }
            Err(e) => {
                error!("Error occurred while CAN receiving a message: {:?}", e);
            }
        }
    });

    let can_transmitter = tokio::spawn(async move {
        while let Some(frame) = in_rx.recv().await {
            info!("CAN(out): {:?}", frame);
            if let Err(e) = outgoing.send(frame).await {
                error!("Error occurred while sending CAN frame: {:?}", e);
            }
        }
    });

    if let (Err(e), _) = tokio::join!(can_transmitter, can_receiver) {
        error!("Error occurred in can_transmitter task: {:?}", e);
    }
}

///       (in_tx   ,   in_rx )      = sync::mpsc::channel();
///       (out_tx  ,   out_rx)      = sync::mpsc::channel();
///     -> in_tx ----> in_rx ->
///  WS                          CAN
///     <- out_tx <---- out_rx <-
pub async fn run(ws_addr: &str, can_addr: &str) -> Result<(), Box<dyn std::error::Error>> {
    let (in_tx, in_rx) = sync::mpsc::channel(100);
    let (out_tx, out_rx) = sync::mpsc::channel(100);

    let ws = start_ws(&ws_addr, &in_tx, out_rx);
    let can = start_can(&can_addr, &out_tx, in_rx);

    tokio::join!(ws, can);

    Ok(())
}