sshd: reduce tokio usage

src/cmd/init/sshd.rs

@@ -1,6 +1,8 @@
 use log::{info, warn};
-use std::{fs, io::Write, os::unix::fs::PermissionsExt, process::Stdio};
-use tokio::{net, process::Command};
+use std::{
+    fs, io::Write, os::unix::fs::PermissionsExt, process::Command, process::Stdio, sync::Arc,
+    thread,
+};
 
 use super::retry_or_ignore;
 use dkl::bootstrap::{Config, SSHServer};
@@ -29,22 +31,24 @@ pub async fn start(cfg: &Config) {
     })
     .await;
 
-    let cfg = cfg.ssh.clone();
+    let cfg = Arc::new(cfg.ssh.clone());
     retry_or_ignore(async move || {
         // don't pre-start sshd as it should rarely be useful at this stage, use inetd-style.
         let listen_addr = cfg.listen.clone();
         info!("ssh: starting listener on {listen_addr}");
 
-        let listener = net::TcpListener::bind(listen_addr).await?;
+        let listener = tokio::net::TcpListener::bind(listen_addr).await?;
 
-        tokio::spawn(handle_ssh_connections(listener, cfg.clone()));
+        let cfg = cfg.clone();
+        let listener = listener.into_std().unwrap();
+        thread::spawn(move || handle_ssh_connections(listener, &cfg));
 
         Ok(())
     })
     .await;
 }
 
-async fn handle_ssh_connections(listener: net::TcpListener, cfg: SSHServer) {
+fn handle_ssh_connections(listener: std::net::TcpListener, cfg: &SSHServer) {
     let mut sshd_args = Vec::new();
 
     sshd_args.extend(["-i", "-E", "/var/log/sshd.log"]);
@@ -62,7 +66,7 @@ async fn handle_ssh_connections(listener: net::TcpListener, cfg: SSHServer) {
     let mut keygen_done = false;
 
     loop {
-        let (stream, remote) = match listener.accept().await {
+        let (stream, remote) = match listener.accept() {
             Ok(v) => v,
             Err(e) => {
                 warn!("ssh: listener stopped: {e}");
@@ -72,7 +76,7 @@ async fn handle_ssh_connections(listener: net::TcpListener, cfg: SSHServer) {
 
         if !keygen_done {
             // make sure we have ssh host keys even if not provided
-            if (Command::new("ssh-keygen").arg("-A").status().await)
+            if (Command::new("ssh-keygen").arg("-A").status())
                 .inspect_err(|e| warn!("ssh-keygen failed: {e}"))
                 .is_ok_and(|s| s.success())
             {
@@ -96,11 +100,11 @@ async fn handle_ssh_connections(listener: net::TcpListener, cfg: SSHServer) {
             continue;
         };
 
-        let pid = child.id().unwrap();
+        let pid = child.id();
         info!("ssh: new connection from {remote}, sshd PID {pid}");
 
         tokio::spawn(async move {
-            let _ = child.wait().await;
+            let _ = child.wait();
         });
     }
 }