host_can/adapter/socketcan/
mod.rs

1//! SocketCAN adapter
2use crate::adapter::{Adapter, AdapterBaud, AdapterError};
3use crate::frame::{CanFrame, Frame};
4
5use core::cell::RefCell;
6use std::os::fd::AsRawFd;
7use std::os::unix::io::BorrowedFd;
8use std::result::Result;
9use std::time::Duration;
10
11use nix::poll::{PollFd, PollFlags, PollTimeout, poll};
12use socketcan::{
13    BlockingCan, CanFrame as SocketCanFrame, CanInterface, CanSocket, Socket,
14    SocketOptions,
15};
16
17pub struct SocketCanAdapter {
18    rx: RefCell<CanSocket>,
19    tx: RefCell<CanSocket>,
20}
21
22impl SocketCanAdapter {
23    pub fn new(
24        ifname: &str,
25        baud: AdapterBaud,
26    ) -> Result<Self, Box<dyn std::error::Error>> {
27        let iface = CanInterface::open(ifname)?;
28        if let Some(bit_rate) = iface.bit_rate()?
29            && bit_rate as AdapterBaud != baud
30        {
31            return Err(Box::new(AdapterError::UnsupportedBaud));
32        }
33
34        let rx = CanSocket::open(ifname)?;
35        rx.set_loopback(false)?;
36        let tx = CanSocket::open(ifname)?;
37        tx.set_loopback(false)?;
38        Ok(Self {
39            rx: RefCell::new(rx),
40            tx: RefCell::new(tx),
41        })
42    }
43}
44
45impl Adapter for SocketCanAdapter {
46    fn send(&self, frame: &CanFrame) -> Result<(), Box<AdapterError>> {
47        let frame = SocketCanFrame::new(frame.id(), frame.data())
48            .ok_or(AdapterError::WriteFailed)?;
49
50        self.tx
51            .borrow_mut()
52            .transmit(&frame)
53            .or(Err(AdapterError::WriteFailed))?;
54
55        Ok(())
56    }
57
58    fn recv(
59        &self,
60        timeout: Option<Duration>,
61    ) -> Result<CanFrame, Box<AdapterError>> {
62        if let Some(timeout) = timeout {
63            let fd = unsafe {
64                let socket = self.rx.borrow();
65                BorrowedFd::borrow_raw(socket.as_raw_fd())
66            };
67            let pollfd = PollFd::new(fd, PollFlags::POLLIN);
68
69            let poll_timeout = timeout.try_into().unwrap_or(PollTimeout::MAX);
70
71            match poll(&mut [pollfd], poll_timeout) {
72                Ok(1) => {}
73                Ok(0) => {
74                    return Err(Box::new(AdapterError::ReadTimeout));
75                }
76                _ => return Err(Box::new(AdapterError::ReadFailed)),
77            }
78        }
79
80        match self.rx.borrow_mut().receive() {
81            Ok(frame) => {
82                let frame = CanFrame::new(frame.id(), frame.data())
83                    .ok_or(Box::new(AdapterError::ReadFailed))?;
84                Ok(frame)
85            }
86            _ => Err(Box::new(AdapterError::ReadFailed)),
87        }
88    }
89}
host_can/adapter/socketcan/mod.rs

host_can/adapter/socketcan/
mod.rs
