netlink_proto/
handle.rs

1// SPDX-License-Identifier: MIT
2
3use futures::{
4    channel::mpsc::{unbounded, UnboundedSender},
5    Stream,
6};
7use netlink_packet_core::NetlinkMessage;
8use std::fmt::Debug;
9
10use crate::{errors::Error, sys::SocketAddr, Request};
11
12/// A handle to pass requests to a [`Connection`](struct.Connection.html).
13#[derive(Clone, Debug)]
14pub struct ConnectionHandle<T>
15where
16    T: Debug,
17{
18    requests_tx: UnboundedSender<Request<T>>,
19}
20
21impl<T> ConnectionHandle<T>
22where
23    T: Debug,
24{
25    pub(crate) fn new(requests_tx: UnboundedSender<Request<T>>) -> Self {
26        ConnectionHandle { requests_tx }
27    }
28
29    /// Send a new request and get the response as a stream of messages. Note
30    /// that some messages are not part of the response stream:
31    ///
32    /// - **acknowledgements**: when an acknowledgement is received, the stream
33    ///   is closed
34    /// - **end of dump messages**: similarly, upon receiving an "end of dump"
35    ///   message, the stream is closed
36    pub fn request(
37        &self,
38        message: NetlinkMessage<T>,
39        destination: SocketAddr,
40    ) -> Result<impl Stream<Item = NetlinkMessage<T>>, Error<T>> {
41        let (tx, rx) = unbounded::<NetlinkMessage<T>>();
42        let request = Request::from((message, destination, tx));
43        trace!("handle: forwarding new request to connection");
44        UnboundedSender::unbounded_send(&self.requests_tx, request).map_err(
45            |e| {
46                // the channel is unbounded, so it can't be full. If this
47                // failed, it means the Connection shut down.
48                if e.is_full() {
49                    panic!("internal error: unbounded channel full?!");
50                } else if e.is_disconnected() {
51                    Error::ConnectionClosed
52                } else {
53                    panic!("unknown error: {:?}", e);
54                }
55            },
56        )?;
57        Ok(rx)
58    }
59
60    pub fn notify(
61        &self,
62        message: NetlinkMessage<T>,
63        destination: SocketAddr,
64    ) -> Result<(), Error<T>> {
65        let (tx, _rx) = unbounded::<NetlinkMessage<T>>();
66        let request = Request::from((message, destination, tx));
67        trace!("handle: forwarding new request to connection");
68        UnboundedSender::unbounded_send(&self.requests_tx, request)
69            .map_err(|_| Error::ConnectionClosed)
70    }
71}