feat(windows): support remote attach to unix hosts (#2329)

* feat(windows): support remote attach to unix hosts

* fix(remote): preserve unix bridge behavior

1 files changed, 69 insertions, 0 deletions

diff --git a/src/remote/host_unix.rs b/src/remote/host_unix.rs
new file mode 100644
index 00000000..e04b0e00
--- /dev/null
+++ b/src/remote/host_unix.rs
@@ -0,0 +1,69 @@
+//! Unix remote-host side of the SSH stdio bridge.
+
+use std::io;
+use std::os::unix::net::UnixStream;
+use std::thread;
+use std::time::Duration;
+
+pub(crate) fn run_remote_client_bridge() -> io::Result<()> {
+    ensure_remote_server_running()?;
+
+    let socket_path = crate::server::socket_paths::client_socket_path();
+    let stream = UnixStream::connect(&socket_path).map_err(|err| {
+        io::Error::new(
+            err.kind(),
+            format!(
+                "failed to connect to remote Herdr client socket {}: {err}",
+                socket_path.display()
+            ),
+        )
+    })?;
+
+    let mut stdout = io::stdout().lock();
+    let mut socket_to_stdout = stream.try_clone()?;
+    let mut stdin_to_socket = stream;
+
+    let _upload = thread::spawn(move || {
+        let mut stdin = io::stdin();
+        let _ = copy_flush(&mut stdin, &mut stdin_to_socket);
+        let _ = stdin_to_socket.shutdown(std::net::Shutdown::Write);
+    });
+
+    copy_flush(&mut socket_to_stdout, &mut stdout).map(|_| ())
+}
+
+fn copy_flush<R: io::Read, W: io::Write>(reader: &mut R, writer: &mut W) -> io::Result<u64> {
+    let mut buffer = [0_u8; 16 * 1024];
+    let mut total = 0;
+    loop {
+        let read = match reader.read(&mut buffer) {
+            Ok(0) => return Ok(total),
+            Ok(read) => read,
+            Err(err) if err.kind() == io::ErrorKind::Interrupted => continue,
+            Err(err) => return Err(err),
+        };
+        writer.write_all(&buffer[..read])?;
+        writer.flush()?;
+        total += read as u64;
+    }
+}
+
+fn ensure_remote_server_running() -> io::Result<()> {
+    let socket_path = crate::server::socket_paths::client_socket_path();
+    if crate::server::autodetect::is_server_listening() {
+        let status = crate::api::read_runtime_status_at(
+            &crate::api::socket_path(),
+            Duration::from_millis(500),
+        )?
+        .ok_or_else(|| io::Error::other("remote server status API is unavailable"))?;
+        if status.protocol == Some(crate::protocol::PROTOCOL_VERSION) {
+            return Ok(());
+        }
+        return Err(io::Error::other(
+            "remote herdr server must restart before this bridge can attach; rerun `herdr --remote` from an interactive terminal to approve stopping it",
+        ));
+    }
+
+    crate::server::autodetect::spawn_server_daemon()?;
+    crate::server::autodetect::wait_for_server_socket(&socket_path, Duration::from_secs(5))
+}