server: guard gadget cycling

scripts/daemon/lesavka-core.sh

@@ -22,6 +22,15 @@ udc_state() {
     cat "/sys/class/udc/$udc/state" 2>/dev/null || echo "unknown"
 }
 
+is_attached_state() {
+    case "$1" in
+        configured|addressed|default|suspended)
+            return 0
+            ;;
+    esac
+    return 1
+}
+
 detach_gadget() {
     local udc=""
     udc="$(find_udc)"
@@ -177,6 +186,14 @@ fi
 [[ -n $UDC ]] || { log "❌ UDC not present after manual bind"; exit 1; }
 log "✅ UDC detected: $UDC"
 
+# Guard against lockups: don't reset gadget while host is attached unless forced.
+UDC_STATE="$(udc_state "$UDC")"
+if [[ -z ${LESAVKA_ALLOW_GADGET_RESET:-} ]] && is_attached_state "$UDC_STATE"; then
+    log "🔒 UDC state is '$UDC_STATE' - refusing gadget reset while host attached."
+    log "    Set LESAVKA_ALLOW_GADGET_RESET=1 to force."
+    exit 0
+fi
+
 #──────────────────────────────────────────────────
 # 3.  (Re‑)create gadget
 #──────────────────────────────────────────────────

scripts/install/server.sh

@@ -5,6 +5,25 @@ ORIG_USER=${SUDO_USER:-$(id -un)}
 
 REF=${LESAVKA_REF:-master}        # fallback
 
+udc_state() {
+  local udc=""
+  udc=$(ls /sys/class/udc 2>/dev/null | head -n1 || true)
+  if [[ -z $udc ]]; then
+    echo "unknown"
+    return 0
+  fi
+  cat "/sys/class/udc/$udc/state" 2>/dev/null || echo "unknown"
+}
+
+is_attached_state() {
+  case "$1" in
+    configured|addressed|default|suspended|unknown)
+      return 0
+      ;;
+  esac
+  return 1
+}
+
 while [[ $# -gt 0 ]]; do
   case $1 in
     -r|--ref) REF="$2"; shift 2 ;;
@@ -192,9 +211,16 @@ UNIT
 echo "==> 6c. Systemd units - initialization"
 sudo truncate -s 0 /tmp/lesavka-server.log
 sudo systemctl daemon-reload
-sudo systemctl enable --now lesavka-core
-sudo systemctl restart lesavka-core
-echo "✅  lesavka-core installed and restarted..."
+sudo systemctl enable lesavka-core lesavka-uvc lesavka-server
+
+UDC_STATE=$(udc_state)
+if [[ -n ${LESAVKA_ALLOW_GADGET_RESET:-} ]] || ! is_attached_state "$UDC_STATE"; then
+  sudo systemctl restart lesavka-core
+  echo "✅  lesavka-core installed and restarted..."
+else
+  echo "⚠️  UDC state is '$UDC_STATE' - skipping lesavka-core restart."
+  echo "    Set LESAVKA_ALLOW_GADGET_RESET=1 to force."
+fi
 
 cat <<'UNIT' | sudo tee /etc/systemd/system/lesavka-uvc.service >/dev/null
 [Unit]
@@ -217,10 +243,12 @@ User=root
 WantedBy=multi-user.target
 UNIT
 
-sudo systemctl enable --now lesavka-uvc
-sudo systemctl restart lesavka-uvc
-echo "✅  lesavka-uvc installed and restarted..."
+if [[ -n ${LESAVKA_ALLOW_GADGET_RESET:-} ]] || ! is_attached_state "$UDC_STATE"; then
+  sudo systemctl restart lesavka-uvc
+  echo "✅  lesavka-uvc installed and restarted..."
+else
+  echo "⚠️  UDC state is '$UDC_STATE' - skipping lesavka-uvc restart."
+fi
 
-sudo systemctl enable --now lesavka-server
 sudo systemctl restart lesavka-server
 echo "✅  lesavka-server installed and restarted..."

server/src/gadget.rs

@@ -1,6 +1,7 @@
 // server/src/gadget.rs
 use anyhow::{Context, Result};
 use std::{
+    env,
     fs::{self, OpenOptions},
     io::Write,
     path::Path,
@@ -115,6 +116,31 @@ impl UsbGadget {
         let ctrl = Self::find_controller().or_else(|_| {
             Self::probe_platform_udc()?.ok_or_else(|| anyhow::anyhow!("no UDC present"))
         })?;
+        let force_cycle = env::var("LESAVKA_GADGET_FORCE_CYCLE").is_ok();
+        match Self::state(&ctrl) {
+            Ok(state)
+                if !force_cycle
+                    && matches!(state.as_str(), "configured" | "addressed" | "default" | "suspended") =>
+            {
+                warn!(
+                    "🔒 refusing gadget cycle while host attached (state={state}); set LESAVKA_GADGET_FORCE_CYCLE=1 to override"
+                );
+                return Ok(());
+            }
+            Ok(state) if !force_cycle && state == "unknown" => {
+                warn!(
+                    "🔒 refusing gadget cycle with unknown UDC state; set LESAVKA_GADGET_FORCE_CYCLE=1 to override"
+                );
+                return Ok(());
+            }
+            Err(_) if !force_cycle => {
+                warn!(
+                    "🔒 refusing gadget cycle without UDC state; set LESAVKA_GADGET_FORCE_CYCLE=1 to override"
+                );
+                return Ok(());
+            }
+            _ => {}
+        }
 
         /* 1 - detach gadget */
         info!("🔌 detaching gadget from {ctrl}");

server/src/main.rs

@@ -1,4 +1,4 @@
-//! lesavka-server - **auto-cycle disabled**
+//! lesavka-server - gadget cycle guarded by env
 // server/src/main.rs
 #![forbid(unsafe_code)]
 
@@ -26,8 +26,6 @@ use lesavka_common::lesavka::{
 use lesavka_server::{audio, gadget::UsbGadget, handshake::HandshakeSvc, video};
 
 /*──────────────── constants ────────────────*/
-/// **false** = never reset automatically.  
-const AUTO_CYCLE: bool = false;
 const VERSION: &str = env!("CARGO_PKG_VERSION");
 const PKG_NAME: &str = env!("CARGO_PKG_NAME");
 
@@ -90,6 +88,10 @@ fn next_minute() -> SystemTime {
     UNIX_EPOCH + Duration::from_secs(next)
 }
 
+fn allow_gadget_cycle() -> bool {
+    std::env::var("LESAVKA_ALLOW_GADGET_CYCLE").is_ok()
+}
+
 async fn recover_hid_if_needed(
     err: &std::io::Error,
     gadget: UsbGadget,
@@ -109,12 +111,19 @@ async fn recover_hid_if_needed(
         return;
     }
 
+    let allow_cycle = allow_gadget_cycle();
     tokio::spawn(async move {
-        warn!("🔁 HID transport down (errno={code:?}) - cycling gadget");
-        match tokio::task::spawn_blocking(move || gadget.cycle()).await {
-            Ok(Ok(())) => info!("✅ USB gadget cycle complete (auto-recover)"),
-            Ok(Err(e)) => error!("💥 USB gadget cycle failed: {e:#}"),
-            Err(e) => error!("💥 USB gadget cycle task panicked: {e:#}"),
+        if allow_cycle {
+            warn!("🔁 HID transport down (errno={code:?}) - cycling gadget");
+            match tokio::task::spawn_blocking(move || gadget.cycle()).await {
+                Ok(Ok(())) => info!("✅ USB gadget cycle complete (auto-recover)"),
+                Ok(Err(e)) => error!("💥 USB gadget cycle failed: {e:#}"),
+                Err(e) => error!("💥 USB gadget cycle task panicked: {e:#}"),
+            }
+        } else {
+            warn!(
+                "🔒 HID transport down (errno={code:?}) - gadget cycle disabled; set LESAVKA_ALLOW_GADGET_CYCLE=1 to enable"
+            );
         }
 
         if let Err(e) = async {
@@ -258,11 +267,11 @@ struct Handler {
 
 impl Handler {
     async fn new(gadget: UsbGadget) -> anyhow::Result<Self> {
-        if AUTO_CYCLE {
+        if allow_gadget_cycle() {
             info!("🛠️  Initial USB reset…");
             let _ = gadget.cycle(); // ignore failure - may boot without host
         } else {
-            info!("🛠️  AUTO_CYCLE disabled - no initial reset");
+            info!("🔒 gadget cycle disabled at startup (set LESAVKA_ALLOW_GADGET_CYCLE=1 to enable)");
         }
 
         info!("🛠️  opening HID endpoints …");