feat: mudfish client and connect/disconnect controller

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

py_modules/mudfish_decky/system.py

@@ -0,0 +1,73 @@
+"""Steam Deck side effects: locating Mudfish, running its daemon, reading routes and the public IP."""
+import json
+import os
+import subprocess
+import time
+import urllib.request
+from typing import Callable, Optional, Tuple
+
+from .routes import delete_routes  # noqa: F401  (re-exported for the controller)
+
+MUDFISH_ROOT = "/opt/mudfish"
+DAEMON_UNIT = "mudfish-decky"
+DEFAULT_API = "http://127.0.0.1:8282"
+
+
+def _version_key(name: str):
+    try:
+        return tuple(int(p) for p in name.split("."))
+    except ValueError:
+        return None
+
+
+def find_mudfish(root: str = MUDFISH_ROOT) -> Optional[Tuple[str, str]]:
+    """(daemon binary, var dir) of the highest installed Mudfish version."""
+    if not os.path.isdir(root):
+        return None
+    versions = []
+    for name in os.listdir(root):
+        key = _version_key(name)
+        binary = os.path.join(root, name, "bin", "mudrun-headless")
+        if key is not None and os.path.isfile(binary):
+            versions.append((key, name))
+    if not versions:
+        return None
+    name = max(versions)[1]
+    return os.path.join(root, name, "bin", "mudrun-headless"), os.path.join(root, name, "var")
+
+
+def api_base(var_dir: str) -> str:
+    try:
+        with open(os.path.join(var_dir, ".ipport")) as f:
+            ipport = f.read().strip()
+    except OSError:
+        return DEFAULT_API
+    return f"http://{ipport}" if ipport else DEFAULT_API
+
+
+def ensure_daemon(bin_path: str, is_up: Callable[[], bool], run=subprocess.run, sleep=time.sleep) -> None:
+    """Start the launcher as a transient systemd unit so it outlives desktop/game mode switches."""
+    if is_up():
+        return
+    run(["systemd-run", f"--unit={DAEMON_UNIT}", "--collect", bin_path, "-B"], capture_output=True, timeout=10)
+    for _ in range(20):
+        sleep(0.5)
+        if is_up():
+            return
+
+
+def tap_up() -> bool:
+    return os.path.exists("/sys/class/net/tap0")
+
+
+def route_text(run=subprocess.run) -> str:
+    return run(["ip", "-4", "route"], capture_output=True, text=True, timeout=5).stdout
+
+
+def public_ip() -> Optional[dict]:
+    try:
+        with urllib.request.urlopen("https://ipinfo.io/json", timeout=8) as resp:
+            data = json.load(resp)
+        return {"ip": data.get("ip"), "country": data.get("country")}
+    except Exception:
+        return None