Files
bore/src/shared.rs
Eric Zhang d3d5d434ad Update dependencies, including clap v4
Also fix Clippy lints for rustc 1.65 along the way.
2022-11-11 01:08:50 -05:00

117 lines
3.9 KiB
Rust

//! Shared data structures, utilities, and protocol definitions.
use std::time::Duration;
use anyhow::{Context, Result};
use futures_util::{SinkExt, StreamExt};
use serde::de::DeserializeOwned;
use serde::{Deserialize, Serialize};
use tokio::io::{self, AsyncRead, AsyncWrite};
use tokio::time::timeout;
use tokio_util::codec::{AnyDelimiterCodec, Framed, FramedParts};
use tracing::trace;
use uuid::Uuid;
/// TCP port used for control connections with the server.
pub const CONTROL_PORT: u16 = 7835;
/// Maxmium byte length for a JSON frame in the stream.
pub const MAX_FRAME_LENGTH: usize = 256;
/// Timeout for network connections and initial protocol messages.
pub const NETWORK_TIMEOUT: Duration = Duration::from_secs(3);
/// A message from the client on the control connection.
#[derive(Debug, Serialize, Deserialize)]
pub enum ClientMessage {
/// Response to an authentication challenge from the server.
Authenticate(String),
/// Initial client message specifying a port to forward.
Hello(u16),
/// Accepts an incoming TCP connection, using this stream as a proxy.
Accept(Uuid),
}
/// A message from the server on the control connection.
#[derive(Debug, Serialize, Deserialize)]
pub enum ServerMessage {
/// Authentication challenge, sent as the first message, if enabled.
Challenge(Uuid),
/// Response to a client's initial message, with actual public port.
Hello(u16),
/// No-op used to test if the client is still reachable.
Heartbeat,
/// Asks the client to accept a forwarded TCP connection.
Connection(Uuid),
/// Indicates a server error that terminates the connection.
Error(String),
}
/// Transport stream with JSON frames delimited by null characters.
pub struct Delimited<U>(Framed<U, AnyDelimiterCodec>);
impl<U: AsyncRead + AsyncWrite + Unpin> Delimited<U> {
/// Construct a new delimited stream.
pub fn new(stream: U) -> Self {
let codec = AnyDelimiterCodec::new_with_max_length(vec![0], vec![0], MAX_FRAME_LENGTH);
Self(Framed::new(stream, codec))
}
/// Read the next null-delimited JSON instruction from a stream.
pub async fn recv<T: DeserializeOwned>(&mut self) -> Result<Option<T>> {
trace!("waiting to receive json message");
if let Some(next_message) = self.0.next().await {
let byte_message = next_message.context("frame error, invalid byte length")?;
let serialized_obj =
serde_json::from_slice(&byte_message).context("unable to parse message")?;
Ok(serialized_obj)
} else {
Ok(None)
}
}
/// Read the next null-delimited JSON instruction, with a default timeout.
///
/// This is useful for parsing the initial message of a stream for handshake or
/// other protocol purposes, where we do not want to wait indefinitely.
pub async fn recv_timeout<T: DeserializeOwned>(&mut self) -> Result<Option<T>> {
timeout(NETWORK_TIMEOUT, self.recv())
.await
.context("timed out waiting for initial message")?
}
/// Send a null-terminated JSON instruction on a stream.
pub async fn send<T: Serialize>(&mut self, msg: T) -> Result<()> {
trace!("sending json message");
self.0.send(serde_json::to_string(&msg)?).await?;
Ok(())
}
/// Consume this object, returning current buffers and the inner transport.
pub fn into_parts(self) -> FramedParts<U, AnyDelimiterCodec> {
self.0.into_parts()
}
}
/// Copy data mutually between two read/write streams.
pub async fn proxy<S1, S2>(stream1: S1, stream2: S2) -> io::Result<()>
where
S1: AsyncRead + AsyncWrite + Unpin,
S2: AsyncRead + AsyncWrite + Unpin,
{
let (mut s1_read, mut s1_write) = io::split(stream1);
let (mut s2_read, mut s2_write) = io::split(stream2);
tokio::select! {
res = io::copy(&mut s1_read, &mut s2_write) => res,
res = io::copy(&mut s2_read, &mut s1_write) => res,
}?;
Ok(())
}