refactor(client): use tokio's TcpSocket for more sockopts (#2335)

Signed-off-by: Eliza Weisman <eliza@buoyant.io>

Cargo.toml

@@ -35,7 +35,7 @@ itoa = "0.4.1"
 tracing = { version = "0.1", default-features = false, features = ["log", "std"] }
 pin-project = "1.0"
 tower-service = "0.3"
-tokio = { version = "0.3", features = ["sync", "stream"] }
+tokio = { version = "0.3.4", features = ["sync", "stream"] }
 want = "0.3"
 
 # Optional

src/client/connect/http.rs

@@ -569,10 +569,11 @@ fn connect(
     connect_timeout: Option<Duration>,
 ) -> Result<impl Future<Output = Result<TcpStream, ConnectError>>, ConnectError> {
     // TODO(eliza): if Tokio's `TcpSocket` gains support for setting the
-    // keepalive timeout and send/recv buffer size, it would be nice to use that
+    // keepalive timeout, it would be nice to use that instead of socket2,
-    // instead of socket2, and avoid the unsafe `into_raw_fd`/`from_raw_fd`
+    // and avoid the unsafe `into_raw_fd`/`from_raw_fd` dance...
-    // dance...
     use socket2::{Domain, Protocol, Socket, Type};
+    use std::convert::TryInto;
+
     let domain = match *addr {
         SocketAddr::V4(_) => Domain::ipv4(),
         SocketAddr::V6(_) => Domain::ipv6(),
@@ -580,18 +581,18 @@ fn connect(
     let socket = Socket::new(domain, Type::stream(), Some(Protocol::tcp()))
         .map_err(ConnectError::m("tcp open error"))?;
 
-    if config.reuse_address {
-        socket
-            .set_reuse_address(true)
-            .map_err(ConnectError::m("tcp set_reuse_address error"))?;
-    }
-
     // When constructing a Tokio `TcpSocket` from a raw fd/socket, the user is
     // responsible for ensuring O_NONBLOCK is set.
     socket
         .set_nonblocking(true)
         .map_err(ConnectError::m("tcp set_nonblocking error"))?;
 
+    if let Some(dur) = config.keep_alive_timeout {
+        socket
+            .set_keepalive(Some(dur))
+            .map_err(ConnectError::m("tcp set_keepalive error"))?;
+    }
+
     bind_local_address(
         &socket,
         addr,
@@ -600,24 +601,6 @@ fn connect(
     )
     .map_err(ConnectError::m("tcp bind local error"))?;
 
-    if let Some(dur) = config.keep_alive_timeout {
-        socket
-            .set_keepalive(Some(dur))
-            .map_err(ConnectError::m("tcp set_keepalive error"))?;
-    }
-
-    if let Some(size) = config.send_buffer_size {
-        socket
-            .set_send_buffer_size(size)
-            .map_err(ConnectError::m("tcp set_send_buffer_size error"))?;
-    }
-
-    if let Some(size) = config.recv_buffer_size {
-        socket
-            .set_recv_buffer_size(size)
-            .map_err(ConnectError::m("tcp set_recv_buffer_size error"))?;
-    }
-
     #[cfg(unix)]
     let socket = unsafe {
         // Safety: `from_raw_fd` is only safe to call if ownership of the raw
@@ -636,6 +619,25 @@ fn connect(
         use std::os::windows::io::{FromRawSocket, IntoRawSocket};
         TcpSocket::from_raw_socket(socket.into_raw_socket())
     };
+
+    if config.reuse_address {
+        socket
+            .set_reuseaddr(true)
+            .map_err(ConnectError::m("tcp set_reuse_address error"))?;
+    }
+
+    if let Some(size) = config.send_buffer_size {
+        socket
+            .set_send_buffer_size(size.try_into().unwrap_or(std::u32::MAX))
+            .map_err(ConnectError::m("tcp set_send_buffer_size error"))?;
+    }
+
+    if let Some(size) = config.recv_buffer_size {
+        socket
+            .set_recv_buffer_size(size.try_into().unwrap_or(std::u32::MAX))
+            .map_err(ConnectError::m("tcp set_recv_buffer_size error"))?;
+    }
+
     let connect = socket.connect(*addr);
     Ok(async move {
         match connect_timeout {