DNS/TLS deps are now optional, component now also uses ServerConnector

tokio-xmpp/src/connect.rs

@@ -0,0 +1,35 @@
+//! `ServerConnector` provides streams for XMPP clients
+
+use sasl::common::ChannelBinding;
+use tokio::io::{AsyncRead, AsyncWrite};
+use xmpp_parsers::Jid;
+
+use crate::xmpp_stream::XMPPStream;
+
+/// trait returned wrapped in XMPPStream by ServerConnector
+pub trait AsyncReadAndWrite: AsyncRead + AsyncWrite + Unpin + Send {}
+impl<T: AsyncRead + AsyncWrite + Unpin + Send> AsyncReadAndWrite for T {}
+
+/// Trait that must be extended by the implementation of ServerConnector
+pub trait ServerConnectorError: std::error::Error + Send {}
+
+/// Trait called to connect to an XMPP server, perhaps called multiple times
+pub trait ServerConnector: Clone + core::fmt::Debug + Send + Unpin + 'static {
+    /// The type of Stream this ServerConnector produces
+    type Stream: AsyncReadAndWrite;
+    /// Error type to return
+    type Error: ServerConnectorError;
+    /// This must return the connection ready to login, ie if starttls is involved, after TLS has been started, and then after the <stream headers are exchanged
+    fn connect(
+        &self,
+        jid: &Jid,
+        ns: &str,
+    ) -> impl std::future::Future<Output = Result<XMPPStream<Self::Stream>, Self::Error>> + Send;
+
+    /// Return channel binding data if available
+    /// do not fail if channel binding is simply unavailable, just return Ok(None)
+    /// this should only be called after the TLS handshake is finished
+    fn channel_binding(_stream: &Self::Stream) -> Result<ChannelBinding, Self::Error> {
+        Ok(ChannelBinding::None)
+    }
+}