Add support for proxying outgoing WebSocket connections

README.md

@@ -18,7 +18,7 @@ xmpp-proxy in reverse proxy (incoming) mode will:
 
 xmpp-proxy in outgoing mode will:
   1. listen on any number of interfaces/ports
-  2. accept any plain-text TCP connection from a local XMPP server or client
+  2. accept any plain-text TCP or WebSocket connection from a local XMPP server or client
   3. look up the required SRV records
   4. connect to a real XMPP server across the internet over STARTTLS, Direct TLS, QUIC, or WebSocket
   5. fallback to next SRV target or defaults as required to fully connect

src/in_out.rs

@@ -2,21 +2,21 @@
 
 #[cfg(feature = "websocket")]
 use crate::{from_ws, to_ws_new};
-use crate::{slicesubsequence::SliceSubsequence, trace, StanzaFilter, StanzaRead::*, StanzaReader, StanzaWrite::*};
+use crate::{slicesubsequence::SliceSubsequence, trace, AsyncReadAndWrite, StanzaFilter, StanzaRead::*, StanzaReader, StanzaWrite::*};
 use anyhow::{bail, Result};
 #[cfg(feature = "websocket")]
 use futures_util::{
     stream::{SplitSink, SplitStream},
     SinkExt, TryStreamExt,
 };
-use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt, BufReader, BufStream};
+use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt, BufReader};
 #[cfg(feature = "websocket")]
 use tokio_tungstenite::{tungstenite::Message::*, WebSocketStream};
 
 #[cfg(feature = "websocket")]
-type WsWr = SplitSink<WebSocketStream<BufStream<tokio_rustls::TlsStream<tokio::net::TcpStream>>>, tokio_tungstenite::tungstenite::Message>;
+type WsWr = SplitSink<WebSocketStream<Box<dyn AsyncReadAndWrite + Unpin + Send>>, tokio_tungstenite::tungstenite::Message>;
 #[cfg(feature = "websocket")]
-type WsRd = SplitStream<WebSocketStream<BufStream<tokio_rustls::TlsStream<tokio::net::TcpStream>>>>;
+type WsRd = SplitStream<WebSocketStream<Box<dyn AsyncReadAndWrite + Unpin + Send>>>;
 
 pub enum StanzaWrite {
     AsyncWrite(Box<dyn AsyncWrite + Unpin + Send>),

src/lib.rs

@@ -4,6 +4,7 @@ pub use stanzafilter::*;
 mod slicesubsequence;
 use slicesubsequence::*;
 
+use anyhow::bail;
 use std::net::SocketAddr;
 
 pub use log::{debug, error, info, log_enabled, trace};
@@ -21,6 +22,29 @@ pub fn c2s(is_c2s: bool) -> &'static str {
     }
 }
 
+pub async fn first_bytes_match(stream: &tokio::net::TcpStream, p: &mut [u8], matcher: fn(&[u8]) -> bool) -> anyhow::Result<bool> {
+    // sooo... I don't think peek here can be used for > 1 byte without this timer craziness... can it?
+    let len = p.len();
+    // wait up to 10 seconds until len bytes have been read
+    use std::time::{Duration, Instant};
+    let duration = Duration::from_secs(10);
+    let now = Instant::now();
+    loop {
+        let n = stream.peek(p).await?;
+        if n == len {
+            break; // success
+        }
+        if n == 0 {
+            bail!("not enough bytes");
+        }
+        if Instant::now() - now > duration {
+            bail!("less than {} bytes in 10 seconds, closed connection?", len);
+        }
+    }
+
+    Ok(matcher(p))
+}
+
 #[derive(Clone)]
 pub struct Context<'a> {
     conn_id: String,

src/outgoing.rs

@@ -5,10 +5,14 @@ async fn handle_outgoing_connection(stream: tokio::net::TcpStream, client_addr:
 
     let mut in_filter = StanzaFilter::new(config.max_stanza_size_bytes);
 
-    let (in_rd, in_wr) = tokio::io::split(stream);
+    let is_ws = first_bytes_match(&stream, &mut in_filter.buf[0..3], |p| p == b"GET").await?;
 
-    let mut in_rd = StanzaRead::new(in_rd);
-    let mut in_wr = StanzaWrite::new(in_wr);
+    let (mut in_rd, mut in_wr) = if is_ws {
+        incoming_websocket_connection(Box::new(stream), config.max_stanza_size_bytes).await?
+    } else {
+        let (in_rd, in_wr) = tokio::io::split(stream);
+        (StanzaRead::new(in_rd), StanzaWrite::new(in_wr))
+    };
 
     // now read to figure out client vs server
     let (stream_open, is_c2s) = stream_preamble(&mut in_rd, &mut in_wr, client_addr.log_to(), &mut in_filter).await?;

src/tls.rs

@@ -83,35 +83,13 @@ async fn handle_tls_connection(mut stream: tokio::net::TcpStream, client_addr: &
 
     let mut in_filter = StanzaFilter::new(config.max_stanza_size_bytes);
 
-    let direct_tls = {
-        // sooo... I don't think peek here can be used for > 1 byte without this timer
-        // craziness... can it? this could be switched to only peek 1 byte and assume
-        // a leading 0x16 is TLS, it would *probably* be ok ?
-        //let mut p = [0u8; 3];
-        let p = &mut in_filter.buf[0..3];
-        // wait up to 10 seconds until 3 bytes have been read
-        use std::time::{Duration, Instant};
-        let duration = Duration::from_secs(10);
-        let now = Instant::now();
-        loop {
-            let n = stream.peek(p).await?;
-            if n == 3 {
-                break; // success
-            }
-            if n == 0 {
-                bail!("not enough bytes");
-            }
-            if Instant::now() - now > duration {
-                bail!("less than 3 bytes in 10 seconds, closed connection?");
-            }
-        }
-
     /* TLS packet starts with a record "Hello" (0x16), followed by version
      * (0x03 0x00-0x03) (RFC6101 A.1)
      * This means we reject SSLv2 and lower, which is actually a good thing (RFC6176)
+     *
+     * could just check the leading 0x16 is TLS, it would *probably* be ok ?
      */
-        p[0] == 0x16 && p[1] == 0x03 && p[2] <= 0x03
-    };
+    let direct_tls = first_bytes_match(&stream, &mut in_filter.buf[0..3], |p| p[0] == 0x16 && p[1] == 0x03 && p[2] <= 0x03).await?;
 
     client_addr.set_proto(if direct_tls { "directtls-in" } else { "starttls-in" });
     info!("{} direct_tls sniffed", client_addr.log_from());
@@ -218,7 +196,7 @@ async fn handle_tls_connection(mut stream: tokio::net::TcpStream, client_addr: &
         };
 
         if websocket {
-            handle_websocket_connection(stream, config, server_certs, local_addr, client_addr, in_filter).await
+            handle_websocket_connection(Box::new(stream), config, server_certs, local_addr, client_addr, in_filter).await
         } else {
             let (in_rd, in_wr) = tokio::io::split(stream);
             shuffle_rd_wr_filter(StanzaRead::already_buffered(in_rd), StanzaWrite::new(in_wr), config, server_certs, local_addr, client_addr, in_filter).await

src/websocket.rs

@@ -15,8 +15,22 @@ fn ws_cfg(max_stanza_size_bytes: usize) -> Option<WebSocketConfig> {
     })
 }
 
+pub trait AsyncReadAndWrite: tokio::io::AsyncRead + tokio::io::AsyncWrite {}
+
+impl<T: tokio::io::AsyncRead + tokio::io::AsyncWrite> AsyncReadAndWrite for T {}
+
+pub async fn incoming_websocket_connection(stream: Box<dyn AsyncReadAndWrite + Unpin + Send>, max_stanza_size_bytes: usize) -> Result<(StanzaRead, StanzaWrite)> {
+    // accept the websocket
+    // todo: check SEC_WEBSOCKET_PROTOCOL or ORIGIN ?
+    let stream = tokio_tungstenite::accept_async_with_config(stream, ws_cfg(max_stanza_size_bytes)).await?;
+
+    let (in_wr, in_rd) = stream.split();
+
+    Ok((StanzaRead::WebSocketRead(in_rd), StanzaWrite::WebSocketClientWrite(in_wr)))
+}
+
 pub async fn handle_websocket_connection(
-    stream: BufStream<tokio_rustls::TlsStream<tokio::net::TcpStream>>,
+    stream: Box<dyn AsyncReadAndWrite + Unpin + Send>,
     config: CloneableConfig,
     server_certs: ServerCerts,
     local_addr: SocketAddr,
@@ -26,22 +40,9 @@ pub async fn handle_websocket_connection(
     client_addr.set_proto("websocket-in");
     info!("{} connected", client_addr.log_from());
 
-    // accept the websocket
-    // todo: check SEC_WEBSOCKET_PROTOCOL or ORIGIN ?
-    let stream = tokio_tungstenite::accept_async_with_config(stream, ws_cfg(config.max_stanza_size_bytes)).await?;
+    let (in_rd, in_wr) = incoming_websocket_connection(stream, config.max_stanza_size_bytes).await?;
 
-    let (in_wr, in_rd) = stream.split();
-
-    shuffle_rd_wr_filter(
-        StanzaRead::WebSocketRead(in_rd),
-        StanzaWrite::WebSocketClientWrite(in_wr),
-        config,
-        server_certs,
-        local_addr,
-        client_addr,
-        in_filter,
-    )
-    .await
+    shuffle_rd_wr_filter(in_rd, in_wr, config, server_certs, local_addr, client_addr, in_filter).await
 }
 
 pub fn from_ws(stanza: String) -> String {
@@ -97,7 +98,6 @@ pub fn to_ws_new(buf: &[u8], mut end_of_first_tag: usize, is_c2s: bool) -> Resul
 
 use rustls::ServerName;
 use std::convert::TryFrom;
-use tokio::io::BufStream;
 
 use tokio_tungstenite::tungstenite::client::IntoClientRequest;
 use tokio_tungstenite::tungstenite::http::header::{ORIGIN, SEC_WEBSOCKET_PROTOCOL};
@@ -113,9 +113,10 @@ pub async fn websocket_connect(target: SocketAddr, server_name: &str, url: &Uri,
     let stream = tokio::net::TcpStream::connect(target).await?;
     let stream = config.connector.connect(dnsname, stream).await?;
 
-    let stream: tokio_rustls::TlsStream<tokio::net::TcpStream> = stream.into();
+    //let stream: tokio_rustls::TlsStream<tokio::net::TcpStream> = stream.into();
     // todo: tokio_tungstenite seems to have a bug, if the write buffer is non-zero, it'll hang forever, even though we always flush, investigate
-    let stream = BufStream::with_capacity(crate::IN_BUFFER_SIZE, 0, stream);
+    //let stream = BufStream::with_capacity(crate::IN_BUFFER_SIZE, 0, stream);
+    let stream: Box<dyn AsyncReadAndWrite + Unpin + Send> = Box::new(stream);
 
     let (stream, _) = tokio_tungstenite::client_async_with_config(request, stream, ws_cfg(config.max_stanza_size_bytes)).await?;
 

xmpp-proxy.toml

@@ -3,7 +3,7 @@
 incoming_listen = [ "0.0.0.0:5222", "0.0.0.0:5269", "0.0.0.0:443" ]
 # interfaces to listen for reverse proxy QUIC XMPP connections on, should be open to the internet
 quic_listen = [ "0.0.0.0:443" ]
-# interfaces to listen for outgoing proxy TCP XMPP connections on, should be localhost
+# interfaces to listen for outgoing proxy TCP or WebSocket XMPP connections on, should be localhost
 outgoing_listen = [ "127.0.0.1:15270" ]
 
 # these ports shouldn't do any TLS, but should assume any connection from xmpp-proxy is secure