std_embedded_nal/
udp.rs

1use crate::conversion::to_nb;
2use crate::SocketState;
3use embedded_nal::nb;
4use embedded_nal::{UdpClientStack, UdpFullStack};
5use std::io::{self, Error};
6use std::net::{self, IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
7
8pub struct UdpSocket {
9    state: SocketState<net::UdpSocket, net::UdpSocket>,
10}
11
12impl UdpSocket {
13    fn new() -> Self {
14        Self {
15            state: SocketState::new(),
16        }
17    }
18
19    /// Return the raw file descriptor underlying the current socket.
20    ///
21    /// This is primarily intended for use with `select` style mechanisms: Any of the `nb` methods
22    /// of the socket's traits, once returning [`nb::Error::WouldBlock`], will only make progress
23    /// if data or buffer is available on that file descriptor.
24    ///
25    /// If this returns `None`, then the socket is still in a state where it doesn't even have an
26    /// underlying operating system socket, and needs further operations ([UdpFullStack::bind] or
27    /// [UdpClientStack::connect]) to be performed before it can be waited on. (Then again, a
28    /// socket that doesn't return a raw file descriptor should never return `WouldBlock`). Being
29    /// fallible, this is a method and not a trait implemntation of [std::os::fd::AsRawFd].
30    #[cfg(any(unix, target_os = "hermit", target_os = "wasi"))]
31    pub fn as_raw_fd(&self) -> Option<std::os::fd::RawFd> {
32        use std::os::fd::AsRawFd;
33
34        Some(self.state.get_any().ok()?.as_raw_fd())
35    }
36}
37
38impl UdpClientStack for crate::Stack {
39    type UdpSocket = UdpSocket;
40    type Error = Error;
41
42    fn socket(&mut self) -> Result<Self::UdpSocket, Self::Error> {
43        Ok(UdpSocket::new())
44    }
45
46    fn connect(&mut self, socket: &mut Self::UdpSocket, remote: SocketAddr) -> std::io::Result<()> {
47        let any = match remote {
48            SocketAddr::V4(_) => SocketAddr::new(IpAddr::V4(Ipv4Addr::UNSPECIFIED), 0),
49            SocketAddr::V6(_) => SocketAddr::new(IpAddr::V6(Ipv6Addr::UNSPECIFIED), 0),
50        };
51
52        let sock = net::UdpSocket::bind(any)?;
53
54        sock.set_nonblocking(true)?;
55
56        sock.connect(remote)?;
57        socket.state = SocketState::Connected(sock);
58        Ok(())
59    }
60
61    fn send(&mut self, socket: &mut Self::UdpSocket, buffer: &[u8]) -> nb::Result<(), Self::Error> {
62        let sock = socket.state.get_running()?;
63        sock.send(buffer).map(drop).map_err(to_nb)
64    }
65
66    fn receive(
67        &mut self,
68        socket: &mut Self::UdpSocket,
69        buffer: &mut [u8],
70    ) -> nb::Result<(usize, SocketAddr), Self::Error> {
71        let sock = socket.state.get_any_mut()?;
72        sock.recv_from(buffer).map_err(to_nb)
73    }
74
75    fn close(&mut self, _: Self::UdpSocket) -> io::Result<()> {
76        // No-op: Socket gets closed when it is freed
77        //
78        // Could wrap it in an Option, but really that'll only make things messier; users will
79        // probably drop the socket anyway after closing, and can't expect it to be usable with
80        // this API.
81        Ok(())
82    }
83}
84
85impl UdpFullStack for crate::Stack {
86    fn bind(&mut self, socket: &mut UdpSocket, port: u16) -> Result<(), Error> {
87        let anyaddressthisport = SocketAddr::new(IpAddr::V6(Ipv6Addr::UNSPECIFIED), port);
88
89        let sock = net::UdpSocket::bind(anyaddressthisport)?;
90
91        sock.set_nonblocking(true)?;
92
93        socket.state = SocketState::Bound(sock);
94        Ok(())
95    }
96    fn send_to(
97        &mut self,
98        socket: &mut UdpSocket,
99        remote: SocketAddr,
100        buffer: &[u8],
101    ) -> Result<(), nb::Error<Error>> {
102        let sock = socket.state.get_bound()?;
103        sock.send_to(buffer, remote).map(drop).map_err(to_nb)
104    }
105}
std_embedded_nal/udp.rs

std_embedded_nal/
udp.rs
