relay_core_lib/capture/
source.rs

1use std::future::Future;
2use std::net::SocketAddr;
3use std::pin::Pin;
4use tokio::io::{AsyncRead, AsyncWrite};
5
6/// Represents an incoming connection from any source (TCP Listener, eBPF, TUN, etc.)
7pub struct IncomingConnection<IO> {
8    pub stream: IO,
9    pub client_addr: SocketAddr,
10    /// Original destination address (if known via TPROXY/eBPF/NAT lookup)
11    pub target_addr: Option<SocketAddr>,
12}
13
14/// Trait for capturing traffic.
15/// This abstracts away the difference between a simple TCP Listener,
16/// a Transparent Proxy (TPROXY), or a TUN interface with a user-space stack.
17pub trait CaptureSource {
18    type IO: AsyncRead + AsyncWrite + Unpin + Send + 'static;
19
20    /// Accept the next connection from the source
21    #[allow(clippy::type_complexity)]
22    fn accept(
23        &mut self,
24    ) -> Pin<Box<dyn Future<Output = crate::error::Result<IncomingConnection<Self::IO>>> + Send + '_>>;
25
26    /// Returns the addresses this source is listening on (for loop detection)
27    fn listen_addrs(&self) -> Vec<SocketAddr> {
28        vec![]
29    }
30}
31
32// Implement CaptureSource for Tokio TcpListener (Standard Explicit Proxy)
33use tokio::net::TcpListener;
34
35pub struct TcpCaptureSource {
36    listener: TcpListener,
37}
38
39impl TcpCaptureSource {
40    pub fn new(listener: TcpListener) -> Self {
41        Self { listener }
42    }
43}
44
45impl CaptureSource for TcpCaptureSource {
46    type IO = tokio::net::TcpStream;
47
48    fn accept(
49        &mut self,
50    ) -> Pin<Box<dyn Future<Output = crate::error::Result<IncomingConnection<Self::IO>>> + Send + '_>>
51    {
52        Box::pin(async move {
53            let (stream, client_addr) = self.listener.accept().await?;
54            Ok(IncomingConnection {
55                stream,
56                client_addr,
57                target_addr: None, // Standard Proxy doesn't know target until parsing HTTP
58            })
59        })
60    }
61
62    fn listen_addrs(&self) -> Vec<SocketAddr> {
63        if let Ok(addr) = self.listener.local_addr() {
64            vec![addr]
65        } else {
66            vec![]
67        }
68    }
69}
relay_core_lib/capture/source.rs

relay_core_lib/capture/
source.rs
