net: add handling for abstract socket name (#6772)

Author: mox692

tokio/src/net/unix/listener.rs

@@ -3,8 +3,14 @@ use crate::net::unix::{SocketAddr, UnixStream};
 
 use std::fmt;
 use std::io;
+#[cfg(target_os = "android")]
+use std::os::android::net::SocketAddrExt;
+#[cfg(target_os = "linux")]
+use std::os::linux::net::SocketAddrExt;
+#[cfg(any(target_os = "linux", target_os = "android"))]
+use std::os::unix::ffi::OsStrExt;
 use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, RawFd};
-use std::os::unix::net;
+use std::os::unix::net::{self, SocketAddr as StdSocketAddr};
 use std::path::Path;
 use std::task::{Context, Poll};
 
@@ -70,7 +76,20 @@ impl UnixListener {
     where
         P: AsRef<Path>,
     {
-        let listener = mio::net::UnixListener::bind(path)?;
+        // For now, we handle abstract socket paths on linux here.
+        #[cfg(any(target_os = "linux", target_os = "android"))]
+        let addr = {
+            let os_str_bytes = path.as_ref().as_os_str().as_bytes();
+            if os_str_bytes.starts_with(b"\0") {
+                StdSocketAddr::from_abstract_name(os_str_bytes)?
+            } else {
+                StdSocketAddr::from_pathname(path)?
+            }
+        };
+        #[cfg(not(any(target_os = "linux", target_os = "android")))]
+        let addr = StdSocketAddr::from_pathname(path)?;
+
+        let listener = mio::net::UnixListener::bind_addr(&addr)?;
         let io = PollEvented::new(listener)?;
         Ok(UnixListener { io })
     }

tokio/src/net/unix/stream.rs

@@ -8,8 +8,14 @@ use crate::net::unix::SocketAddr;
 use std::fmt;
 use std::io::{self, Read, Write};
 use std::net::Shutdown;
+#[cfg(target_os = "android")]
+use std::os::android::net::SocketAddrExt;
+#[cfg(target_os = "linux")]
+use std::os::linux::net::SocketAddrExt;
+#[cfg(any(target_os = "linux", target_os = "android"))]
+use std::os::unix::ffi::OsStrExt;
 use std::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, RawFd};
-use std::os::unix::net;
+use std::os::unix::net::{self, SocketAddr as StdSocketAddr};
 use std::path::Path;
 use std::pin::Pin;
 use std::task::{Context, Poll};
@@ -66,7 +72,20 @@ impl UnixStream {
     where
         P: AsRef<Path>,
     {
-        let stream = mio::net::UnixStream::connect(path)?;
+        // On linux, abstract socket paths need to be considered.
+        #[cfg(any(target_os = "linux", target_os = "android"))]
+        let addr = {
+            let os_str_bytes = path.as_ref().as_os_str().as_bytes();
+            if os_str_bytes.starts_with(b"\0") {
+                StdSocketAddr::from_abstract_name(os_str_bytes)?
+            } else {
+                StdSocketAddr::from_pathname(path)?
+            }
+        };
+        #[cfg(not(any(target_os = "linux", target_os = "android")))]
+        let addr = StdSocketAddr::from_pathname(path)?;
+
+        let stream = mio::net::UnixStream::connect_addr(&addr)?;
         let stream = UnixStream::new(stream)?;
 
         poll_fn(|cx| stream.io.registration().poll_write_ready(cx)).await?;

tokio/tests/uds_stream.rs

@@ -409,3 +409,16 @@ async fn epollhup() -> io::Result<()> {
     assert_eq!(err.kind(), io::ErrorKind::ConnectionReset);
     Ok(())
 }
+
+// test for https://github.com/tokio-rs/tokio/issues/6767
+#[tokio::test]
+#[cfg(any(target_os = "linux", target_os = "android"))]
+async fn abstract_socket_name() {
+    let socket_path = "\0aaa";
+    let listener = UnixListener::bind(socket_path).unwrap();
+
+    let accept = listener.accept();
+    let connect = UnixStream::connect(&socket_path);
+
+    try_join(accept, connect).await.unwrap();
+}