fix(eye-remote): Use usb1 (ECM) instead of usb0 for Linux hosts

The USB composite gadget creates two network interfaces:
- usb0: RNDIS function (for Windows hosts)
- usb1: ECM function (for Linux/Mac hosts via cdc_ether driver)

Previously, both interfaces were configured with the same IP (10.55.0.2/30),
causing asymmetric routing issues where packets received on usb1 could be
replied via usb0.

Fix: Configure only usb1 (ECM) since that's what Linux hosts use.
Falls back to usb0 if usb1 is not present (e.g., single-function gadget).

Changes:
- secubox-otg-gadget.sh: Wait for and configure usb1 instead of usb0
- gadget-setup.sh: Same fix for eye-remote variant
- agent/main.py: Update ensure_usb_network() to prefer usb1
- agent/network_debug.py: New debug script for USB network troubleshooting

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

remote-ui/round/agent/main.py

@@ -26,6 +26,52 @@ from touch_handler import TouchHandler, create_touch_handler, Gesture
 
 log = logging.getLogger(__name__)
 
+
+def ensure_usb_network():
+    """Ensure USB network interface is configured for OTG connection.
+
+    The composite gadget creates two interfaces:
+      - usb0: RNDIS (Windows compatible)
+      - usb1: ECM (Linux/Mac compatible via cdc_ether driver)
+
+    Linux hosts use cdc_ether which maps to usb1.
+    We configure only usb1 to avoid asymmetric routing issues.
+    """
+    import subprocess
+    import time
+
+    for attempt in range(30):
+        # Prefer usb1 (ECM) for Linux hosts
+        if Path("/sys/class/net/usb1").exists():
+            try:
+                subprocess.run(["/sbin/ip", "addr", "flush", "dev", "usb1"],
+                             capture_output=True, timeout=5)
+                subprocess.run(["/sbin/ip", "addr", "add", "10.55.0.2/30", "dev", "usb1"],
+                             capture_output=True, timeout=5)
+                subprocess.run(["/sbin/ip", "link", "set", "usb1", "up"],
+                             capture_output=True, timeout=5)
+                log.info(f"usb1 (ECM) configured: 10.55.0.2/30 (attempt {attempt + 1})")
+                return True
+            except Exception as e:
+                log.warning(f"Failed to configure usb1: {e}")
+        # Fallback to usb0 (RNDIS) if usb1 not present
+        elif Path("/sys/class/net/usb0").exists():
+            try:
+                subprocess.run(["/sbin/ip", "addr", "flush", "dev", "usb0"],
+                             capture_output=True, timeout=5)
+                subprocess.run(["/sbin/ip", "addr", "add", "10.55.0.2/30", "dev", "usb0"],
+                             capture_output=True, timeout=5)
+                subprocess.run(["/sbin/ip", "link", "set", "usb0", "up"],
+                             capture_output=True, timeout=5)
+                log.info(f"usb0 (RNDIS) configured: 10.55.0.2/30 (attempt {attempt + 1})")
+                return True
+            except Exception as e:
+                log.warning(f"Failed to configure usb0: {e}")
+        time.sleep(1)
+
+    log.warning("No USB network interface found after 30 attempts")
+    return False
+
 # Default paths
 SOCKET_PATH = Path("/run/secubox-eye/metrics.sock")
 PID_FILE = Path("/run/secubox-eye/agent.pid")
@@ -359,6 +405,9 @@ async def main():
         format="%(asctime)s [%(levelname)s] %(name)s: %(message)s"
     )
 
+    # Ensure USB OTG network is configured
+    ensure_usb_network()
+
     # Parse args
     config_path = DEFAULT_CONFIG_PATH
     if len(sys.argv) > 1:

remote-ui/round/agent/network_debug.py

@@ -0,0 +1,83 @@
+#!/usr/bin/env python3
+"""Configure USB network interface for OTG connection.
+
+For Linux/Mac hosts: Only configure usb1 (ECM) to avoid routing issues.
+The composite gadget creates:
+  - usb0: RNDIS (Windows compatible)
+  - usb1: ECM (Linux/Mac compatible via cdc_ether driver)
+
+Linux hosts use the cdc_ether driver which maps to usb1.
+Configuring both interfaces with the same IP causes asymmetric routing.
+
+CyberMind - https://cybermind.fr
+Author: Gerald Kerma <gandalf@gk2.net>
+"""
+import subprocess
+import time
+from pathlib import Path
+
+LOG = "/var/log/usb_network_debug.log"
+
+
+def log(msg: str) -> None:
+    """Log message to file and stdout."""
+    with open(LOG, "a") as f:
+        f.write(f"{time.strftime('%H:%M:%S')} {msg}\n")
+    print(msg)
+
+
+def configure_interface(iface: str, ip: str) -> bool:
+    """Configure a USB network interface with IP address."""
+    if not Path(f"/sys/class/net/{iface}").exists():
+        return False
+
+    log(f"Configuring {iface} with {ip}")
+
+    # Flush existing addresses
+    r = subprocess.run(["/sbin/ip", "addr", "flush", "dev", iface],
+                       capture_output=True, text=True)
+    log(f"  flush: rc={r.returncode}")
+
+    # Add IP address
+    r = subprocess.run(["/sbin/ip", "addr", "add", ip, "dev", iface],
+                       capture_output=True, text=True)
+    log(f"  addr add: rc={r.returncode}")
+
+    # Bring interface up
+    r = subprocess.run(["/sbin/ip", "link", "set", iface, "up"],
+                       capture_output=True, text=True)
+    log(f"  link up: rc={r.returncode}")
+
+    # Show final state
+    r = subprocess.run(["ip", "addr", "show", iface], capture_output=True, text=True)
+    log(f"  state:\n{r.stdout}")
+
+    return r.returncode == 0
+
+
+def main() -> bool:
+    """Configure USB network interface."""
+    log("=== USB Network Config Started ===")
+    log("Linux/Mac hosts use ECM (usb1), Windows uses RNDIS (usb0)")
+
+    # Wait for usb1 (ECM) interface - this is what Linux hosts use
+    for attempt in range(30):
+        if Path("/sys/class/net/usb1").exists():
+            log(f"usb1 (ECM) found at attempt {attempt + 1}")
+            configure_interface("usb1", "10.55.0.2/30")
+            log("=== USB Network Config Complete ===")
+            return True
+        time.sleep(1)
+
+    # Fallback to usb0 if usb1 doesn't appear (Windows host or single-function gadget)
+    if Path("/sys/class/net/usb0").exists():
+        log("usb1 not found, falling back to usb0 (RNDIS)")
+        configure_interface("usb0", "10.55.0.2/30")
+        return True
+
+    log("ERROR: No USB interfaces found after 30 seconds")
+    return False
+
+
+if __name__ == "__main__":
+    main()

remote-ui/round/files/etc/secubox/eye-remote/gadget-setup.sh

@@ -214,17 +214,25 @@ gadget_up() {
     debug "Binding to UDC: ${udc}"
     echo "$udc" > UDC
 
-    # Wait for usb0 interface to appear
+    # Wait for usb1 (ECM) interface to appear
+    # Note: Composite gadget creates usb0 (RNDIS/Windows) and usb1 (ECM/Linux-Mac)
+    # Linux hosts use cdc_ether driver which maps to usb1
     local retry=0
-    while [[ ! -d /sys/class/net/usb0 ]] && [[ $retry -lt 10 ]]; do
+    while [[ ! -d /sys/class/net/usb1 ]] && [[ $retry -lt 10 ]]; do
         sleep 0.5
         ((retry++))
     done
 
-    if [[ -d /sys/class/net/usb0 ]]; then
-        debug "Interface usb0 created"
+    if [[ -d /sys/class/net/usb1 ]]; then
+        debug "Interface usb1 (ECM) created"
+
+        # Configure IP on usb1 only (avoids asymmetric routing with same IP on both)
+        ip addr flush dev usb1 2>/dev/null || true
+        ip addr add 10.55.0.2/30 dev usb1
+        ip link set usb1 up
+        debug "usb1 configured: 10.55.0.2/30"
     else
-        err "Interface usb0 did not appear after 5s"
+        err "Interface usb1 did not appear after 5s"
         return 1
     fi
 

remote-ui/round/secubox-otg-gadget.sh

@@ -266,24 +266,26 @@ gadget_start() {
     log "Activation sur UDC: ${udc}"
     echo "$udc" > UDC
 
-    # Attendre que l'interface usb0 apparaisse
+    # Attendre que l'interface usb1 (ECM) apparaisse
+    # Note: Le gadget composite crée usb0 (RNDIS/Windows) et usb1 (ECM/Linux-Mac)
+    # On configure usb1 car les hôtes Linux utilisent le driver cdc_ether (ECM)
     local retry=0
-    while [[ ! -d /sys/class/net/usb0 ]] && [[ $retry -lt 10 ]]; do
+    while [[ ! -d /sys/class/net/usb1 ]] && [[ $retry -lt 10 ]]; do
         sleep 0.5
         ((retry++))
     done
 
-    if [[ -d /sys/class/net/usb0 ]]; then
-        log "Interface usb0 créée"
+    if [[ -d /sys/class/net/usb1 ]]; then
+        log "Interface usb1 (ECM) créée"
 
-        # Configurer l'IP
-        ip addr flush dev usb0 2>/dev/null || true
-        ip addr add "${OTG_NETWORK_DEV}/30" dev usb0
-        ip link set usb0 up
+        # Configurer l'IP sur usb1 uniquement (évite le routage asymétrique)
+        ip addr flush dev usb1 2>/dev/null || true
+        ip addr add "${OTG_NETWORK_DEV}/30" dev usb1
+        ip link set usb1 up
 
-        log "usb0 configuré: ${OTG_NETWORK_DEV}/30"
+        log "usb1 configuré: ${OTG_NETWORK_DEV}/30"
     else
-        err "Interface usb0 non créée après 5s"
+        err "Interface usb1 non créée après 5s"
         return 1
     fi