Merge pull request #2 from GreenPenguino/redirect

Redirect connections
This commit is contained in:
Erik van Bennekum 2023-03-20 15:46:49 +01:00 committed by GitHub
commit d4c9a80ebe
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2 changed files with 143 additions and 32 deletions

76
examples/listen_server.rs Normal file
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@ -0,0 +1,76 @@
//! A "hello world" echo server with Tokio
//!
//! This server will create a TCP listener, accept connections in a loop, and
//! write back everything that's read off of each TCP connection.
//!
//! Because the Tokio runtime uses a thread pool, each TCP connection is
//! processed concurrently with all other TCP connections across multiple
//! threads.
//!
//! To see this server in action, you can run this in one terminal:
//!
//! cargo run --example echo
//!
//! and in another terminal you can run:
//!
//! cargo run --example connect 127.0.0.1:8080
//!
//! Each line you type in to the `connect` terminal should be echo'd back to
//! you! If you open up multiple terminals running the `connect` example you
//! should be able to see them all make progress simultaneously.
#![warn(rust_2018_idioms)]
use tokio::io::{AsyncReadExt};
use tokio::net::TcpListener;
use std::env;
use std::error::Error;
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
// Allow passing an address to listen on as the first argument of this
// program, but otherwise we'll just set up our TCP listener on
// 127.0.0.1:8080 for connections.
let addr = env::args()
.nth(1)
.unwrap_or_else(|| "127.0.0.1:8080".to_string());
// Next up we create a TCP listener which will listen for incoming
// connections. This TCP listener is bound to the address we determined
// above and must be associated with an event loop.
let listener = TcpListener::bind(&addr).await?;
println!("Listening on: {addr}");
loop {
// Asynchronously wait for an inbound socket.
let (mut socket, _) = listener.accept().await?;
// And this is where much of the magic of this server happens. We
// crucially want all clients to make progress concurrently, rather than
// blocking one on completion of another. To achieve this we use the
// `tokio::spawn` function to execute the work in the background.
//
// Essentially here we're executing a new task to run concurrently,
// which will allow all of our clients to be processed concurrently.
tokio::spawn(async move {
let mut buf = vec![0; 1024];
// In a loop, read data from the socket and write the data back.
loop {
let n = socket
.read(&mut buf)
.await
.expect("failed to read data from socket");
if n == 0 {
return;
}
use std::str;
println!("{}", str::from_utf8(&buf[0..n]).unwrap());
}
});
}
}

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@ -2,7 +2,7 @@ use axum::extract::State;
use axum::{http::StatusCode, Json}; use axum::{http::StatusCode, Json};
use serde::{Deserialize, Serialize}; use serde::{Deserialize, Serialize};
use std::collections::HashMap; use std::collections::HashMap;
use std::net::{Ipv4Addr, SocketAddrV4}; use std::net::{IpAddr, SocketAddr};
use std::sync::{Arc, Mutex}; use std::sync::{Arc, Mutex};
use tokio::io::{self, AsyncWriteExt}; use tokio::io::{self, AsyncWriteExt};
use tokio::net::{TcpListener, TcpStream}; use tokio::net::{TcpListener, TcpStream};
@ -20,12 +20,12 @@ enum Command {
New { New {
incoming_port: u16, incoming_port: u16,
destination_port: u16, destination_port: u16,
destination_ip: Ipv4Addr, destination_ip: IpAddr,
id: Uuid, id: Uuid,
}, },
Modify { Modify {
destination_port: u16, destination_port: u16,
destination_ip: Ipv4Addr, destination_ip: IpAddr,
id: Uuid, id: Uuid,
}, },
Delete { Delete {
@ -53,7 +53,7 @@ impl GlobalState {
#[derive(Debug)] #[derive(Debug)]
struct ProxyState { struct ProxyState {
destination: SocketAddrV4, destination: SocketAddr,
control: Sender<ProxyControlMessage>, control: Sender<ProxyControlMessage>,
} }
@ -65,7 +65,7 @@ pub async fn process_command(
State(state): State<Arc<GlobalState>>, State(state): State<Arc<GlobalState>>,
Json(payload): Json<ProxyCommand>, Json(payload): Json<ProxyCommand>,
) -> (StatusCode, Json<ProxyResponse>) { ) -> (StatusCode, Json<ProxyResponse>) {
tracing::error!("Received payload: {:?}", payload); tracing::info!("Received payload: {:?}", payload);
// TODO: verify signature // TODO: verify signature
match payload.command { match payload.command {
Command::New { Command::New {
@ -74,7 +74,7 @@ pub async fn process_command(
destination_ip, destination_ip,
id, id,
} => { } => {
let addr = SocketAddrV4::new(destination_ip, destination_port); let addr = SocketAddr::new(destination_ip, destination_port);
let (tx, rx) = watch::channel(ProxyControlMessage::Open { destination: addr }); let (tx, rx) = watch::channel(ProxyControlMessage::Open { destination: addr });
state.proxies.lock().unwrap().insert( state.proxies.lock().unwrap().insert(
id, id,
@ -117,7 +117,7 @@ pub async fn process_command(
#[derive(Debug)] #[derive(Debug)]
enum ProxyControlMessage { enum ProxyControlMessage {
Open { destination: SocketAddrV4 }, // Reroute { new: SocketAddr }, Open { destination: SocketAddr },
Close, Close,
} }
@ -131,17 +131,11 @@ async fn add_proxy(in_port: u16, control: Receiver<ProxyControlMessage>) -> anyh
} }
async fn proxy(listener: TcpListener, mut control: Receiver<ProxyControlMessage>) { async fn proxy(listener: TcpListener, mut control: Receiver<ProxyControlMessage>) {
let mut current_destination =
if let ProxyControlMessage::Open { destination } = *control.borrow() {
Some(destination)
} else {
None
};
loop { loop {
tokio::select! { tokio::select! {
l = listener.accept()=> { l = listener.accept()=> {
if let Ok((inbound, _)) = l { if let Ok((inbound, _)) = l {
let transfer = transfer(inbound, current_destination.unwrap()); let transfer = transfer(inbound, control.clone());
tokio::spawn(transfer); tokio::spawn(transfer);
} }
@ -150,7 +144,6 @@ async fn proxy(listener: TcpListener, mut control: Receiver<ProxyControlMessage>
match *control.borrow() { match *control.borrow() {
ProxyControlMessage::Open { destination } => { ProxyControlMessage::Open { destination } => {
tracing::info!("destination for proxy port {} changed to {}", listener.local_addr().unwrap(), destination); tracing::info!("destination for proxy port {} changed to {}", listener.local_addr().unwrap(), destination);
current_destination=Some(destination);
}, },
ProxyControlMessage::Close => { ProxyControlMessage::Close => {
tracing::info!("destination for proxy port {} closed", listener.local_addr().unwrap()); tracing::info!("destination for proxy port {} closed", listener.local_addr().unwrap());
@ -162,8 +155,18 @@ async fn proxy(listener: TcpListener, mut control: Receiver<ProxyControlMessage>
} }
} }
async fn transfer(mut inbound: TcpStream, destination: SocketAddrV4) -> anyhow::Result<()> { async fn transfer(
let mut outbound = TcpStream::connect(destination).await?; mut inbound: TcpStream,
mut control: Receiver<ProxyControlMessage>,
) -> anyhow::Result<()> {
loop {
let current_destination =
if let ProxyControlMessage::Open { destination } = *control.borrow() {
Some(destination)
} else {
break Ok(());
};
let mut outbound = TcpStream::connect(current_destination.unwrap()).await?;
let (mut ri, mut wi) = inbound.split(); let (mut ri, mut wi) = inbound.split();
let (mut ro, mut wo) = outbound.split(); let (mut ro, mut wo) = outbound.split();
@ -178,17 +181,49 @@ async fn transfer(mut inbound: TcpStream, destination: SocketAddrV4) -> anyhow::
wi.shutdown().await wi.shutdown().await
}; };
tokio::try_join!(client_to_server, server_to_client)?; // Select between the copy tasks and watch channel
tokio::select! {
// Join the two copy streams and wait for the connection to clone
result = async move { tokio::join!(client_to_server, server_to_client) } => {
match result {
(Ok(_), Ok(_)) => {
break Ok(());
}
(r1, r2) => {
if r1.is_err() {
tracing::error!("error closing client->server of {:?}: {:?}", inbound, &r1);
}
if r2.is_err() {
tracing::error!("error closing server->client of {:?}: {:?}", inbound, &r2);
}
r1?;
r2?;
},
}
}
_ = control.changed() => {
match *control.borrow() {
ProxyControlMessage::Open { destination } => {
eprintln!("Switching to new destination: {destination}");
// Disconnect the current outbound connection and restart the loop
drop(outbound);
continue;
},
ProxyControlMessage::Close => {
break Ok(());
},
}
Ok(()) }
}
}
} }
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
use std::net::Ipv4Addr; use std::net::{IpAddr, Ipv4Addr};
use crate::{Command, ProxyCommand}; use crate::{Command, ProxyCommand};
use serde::{Deserialize, Serialize};
use uuid::uuid; use uuid::uuid;
#[test] #[test]
@ -197,7 +232,7 @@ mod tests {
command: Command::New { command: Command::New {
incoming_port: 5555, incoming_port: 5555,
destination_port: 6666, destination_port: 6666,
destination_ip: Ipv4Addr::new(127, 0, 0, 1), destination_ip: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
id: uuid!("67e55044-10b1-426f-9247-bb680e5fe0c8"), id: uuid!("67e55044-10b1-426f-9247-bb680e5fe0c8"),
}, },
signature: [0u8; 32], signature: [0u8; 32],