transports/tcp/: Call take_error on TCP socket

CHANGELOG.md

@@ -46,6 +46,7 @@
 
 - Update individual crates.
   - `libp2p-relay`
+  - `libp2p-tcp`
 
 ## Version 0.42.0 [2022-01-27]
 

Cargo.toml

@@ -106,7 +106,7 @@ smallvec = "1.6.1"
 libp2p-deflate = { version = "0.31.0", path = "transports/deflate", optional = true }
 libp2p-dns = { version = "0.31.0", path = "transports/dns", optional = true, default-features = false }
 libp2p-mdns = { version = "0.34.0", path = "protocols/mdns", optional = true }
-libp2p-tcp = { version = "0.31.0", path = "transports/tcp", default-features = false, optional = true }
+libp2p-tcp = { version = "0.31.1", path = "transports/tcp", default-features = false, optional = true }
 libp2p-websocket = { version = "0.33.0", path = "transports/websocket", optional = true }
 
 [dev-dependencies]

transports/tcp/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 0.31.1 [unreleased]
+
+- Call `TcpSocket::take_error` to report connection establishment errors early.
+
 # 0.31.0 [2022-01-27]
 
 - Update dependencies.

transports/tcp/Cargo.toml

@@ -3,7 +3,7 @@ name = "libp2p-tcp"
 edition = "2021"
 rust-version = "1.56.1"
 description = "TCP/IP transport protocol for libp2p"
-version = "0.31.0"
+version = "0.31.1"
 authors = ["Parity Technologies <admin@parity.io>"]
 license = "MIT"
 repository = "https://github.com/libp2p/rust-libp2p"

transports/tcp/src/lib.rs

@@ -852,6 +852,8 @@ mod tests {
                             panic!("No TCP port in address: {}", a)
                         }
                         ready_tx.send(a).await.ok();
+                    }
+                    ListenerEvent::Upgrade { .. } => {
                         return;
                     }
                     _ => {}

transports/tcp/src/provider/async_io.rs

@@ -44,9 +44,18 @@ impl Provider for Tcp {
 
     fn new_stream(s: net::TcpStream) -> BoxFuture<'static, io::Result<Self::Stream>> {
         async move {
+            // Taken from [`Async::connect`].
+
             let stream = Async::new(s)?;
+
+            // The stream becomes writable when connected.
             stream.writable().await?;
-            Ok(stream)
+
+            // Check if there was an error while connecting.
+            match stream.get_ref().take_error()? {
+                None => Ok(stream),
+                Some(err) => Err(err),
+            }
         }
         .boxed()
     }