Add localplatform stuff to its own package

4 files changed, 436 insertions, 0 deletions

diff --git a/backend/src/localplatform/localplatform.py b/backend/src/localplatform/localplatform.py
new file mode 100644
index 00000000..028eff8f
--- /dev/null
+++ b/backend/src/localplatform/localplatform.py
@@ -0,0 +1,52 @@
+import platform, os
+
+ON_WINDOWS = platform.system() == "Windows"
+ON_LINUX = not ON_WINDOWS
+
+if ON_WINDOWS:
+    from .localplatformwin import *
+    from . import localplatformwin as localplatform
+else:
+    from .localplatformlinux import *
+    from . import localplatformlinux as localplatform
+
+def get_privileged_path() -> str:
+    '''Get path accessible by elevated user. Holds plugins, decky loader and decky loader configs'''
+    return localplatform.get_privileged_path()
+
+def get_unprivileged_path() -> str:
+    '''Get path accessible by non-elevated user. Holds plugin configuration, plugin data and plugin logs. Externally referred to as the 'Homebrew' directory'''
+    return localplatform.get_unprivileged_path()
+
+def get_unprivileged_user() -> str:
+    '''Get user that should own files made in unprivileged path'''
+    return localplatform.get_unprivileged_user()
+
+def get_chown_plugin_path() -> bool:
+    return os.getenv("CHOWN_PLUGIN_PATH", "1") == "1"
+
+def get_server_host() -> str:
+    return os.getenv("SERVER_HOST", "127.0.0.1")
+
+def get_server_port() -> int:
+    return int(os.getenv("SERVER_PORT", "1337"))
+
+def get_live_reload() -> bool:
+    return os.getenv("LIVE_RELOAD", "1") == "1"
+
+def get_keep_systemd_service() -> bool:
+    return os.getenv("KEEP_SYSTEMD_SERVICE", "0") == "1"
+
+def get_log_level() -> int:
+    return {"CRITICAL": 50, "ERROR": 40, "WARNING": 30, "INFO": 20, "DEBUG": 10}[
+        os.getenv("LOG_LEVEL", "INFO")
+    ]
+
+def get_selinux() -> bool:
+    if ON_LINUX:
+        from subprocess import check_output
+        try:
+          if (check_output("getenforce").decode("ascii").strip("\n") == "Enforcing"): return True
+        except FileNotFoundError:
+          pass
+    return False
diff --git a/backend/src/localplatform/localplatformlinux.py b/backend/src/localplatform/localplatformlinux.py
new file mode 100644
index 00000000..1ec3fc1a
--- /dev/null
+++ b/backend/src/localplatform/localplatformlinux.py
@@ -0,0 +1,192 @@
+import os, pwd, grp, sys, logging
+from subprocess import call, run, DEVNULL, PIPE, STDOUT
+from ..customtypes import UserType
+
+logger = logging.getLogger("localplatform")
+
+# Get the user id hosting the plugin loader
+def _get_user_id() -> int:
+    return pwd.getpwnam(_get_user()).pw_uid
+
+# Get the user hosting the plugin loader
+def _get_user() -> str:
+    return get_unprivileged_user()
+
+# Get the effective user id of the running process
+def _get_effective_user_id() -> int:
+    return os.geteuid()
+
+# Get the effective user of the running process
+def _get_effective_user() -> str:
+    return pwd.getpwuid(_get_effective_user_id()).pw_name
+
+# Get the effective user group id of the running process
+def _get_effective_user_group_id() -> int:
+    return os.getegid()
+
+# Get the effective user group of the running process
+def _get_effective_user_group() -> str:
+    return grp.getgrgid(_get_effective_user_group_id()).gr_name
+
+# Get the user owner of the given file path.
+def _get_user_owner(file_path: str) -> str:
+    return pwd.getpwuid(os.stat(file_path).st_uid).pw_name
+
+# Get the user group of the given file path, or the user group hosting the plugin loader
+def _get_user_group(file_path: str | None = None) -> str:
+    return grp.getgrgid(os.stat(file_path).st_gid if file_path is not None else _get_user_group_id()).gr_name
+
+# Get the group id of the user hosting the plugin loader
+def _get_user_group_id() -> int:
+    return pwd.getpwuid(_get_user_id()).pw_gid
+
+def chown(path : str,  user : UserType = UserType.HOST_USER, recursive : bool = True) -> bool:
+    user_str = ""
+
+    if user == UserType.HOST_USER:
+        user_str = _get_user()+":"+_get_user_group()
+    elif user == UserType.EFFECTIVE_USER:
+        user_str = _get_effective_user()+":"+_get_effective_user_group()
+    elif user == UserType.ROOT:
+        user_str = "root:root"
+    else:
+        raise Exception("Unknown User Type")
+
+    result = call(["chown", "-R", user_str, path] if recursive else ["chown", user_str, path])
+    return result == 0
+
+def chmod(path : str, permissions : int, recursive : bool = True) -> bool:
+    if _get_effective_user_id() != 0:
+        return True
+    result = call(["chmod", "-R", str(permissions), path] if recursive else ["chmod", str(permissions), path])
+    return result == 0
+
+def folder_owner(path : str) -> UserType|None:
+    user_owner = _get_user_owner(path)
+
+    if (user_owner == _get_user()):
+        return UserType.HOST_USER
+
+    elif (user_owner == _get_effective_user()):
+        return UserType.EFFECTIVE_USER
+
+    else:
+        return None 
+
+def get_home_path(user : UserType = UserType.HOST_USER) -> str:
+    user_name = "root"
+
+    if user == UserType.HOST_USER:
+        user_name = _get_user()
+    elif user == UserType.EFFECTIVE_USER:
+        user_name = _get_effective_user()
+    elif user == UserType.ROOT:
+        pass
+    else:
+        raise Exception("Unknown User Type")
+
+    return pwd.getpwnam(user_name).pw_dir
+
+def get_username() -> str:
+    return _get_user()
+
+def setgid(user : UserType = UserType.HOST_USER):
+    user_id = 0
+
+    if user == UserType.HOST_USER:
+        user_id = _get_user_group_id()
+    elif user == UserType.ROOT:
+        pass
+    else:
+        raise Exception("Unknown user type")
+    
+    os.setgid(user_id)
+
+def setuid(user : UserType = UserType.HOST_USER):
+    user_id = 0
+
+    if user == UserType.HOST_USER:
+        user_id = _get_user_id()
+    elif user == UserType.ROOT:
+        pass
+    else:
+        raise Exception("Unknown user type")
+    
+    os.setuid(user_id)
+
+async def service_active(service_name : str) -> bool:
+    res = run(["systemctl", "is-active", service_name], stdout=DEVNULL, stderr=DEVNULL)
+    return res.returncode == 0
+
+async def service_restart(service_name : str) -> bool:
+    call(["systemctl", "daemon-reload"])
+    cmd = ["systemctl", "restart", service_name]
+    res = run(cmd, stdout=PIPE, stderr=STDOUT)
+    return res.returncode == 0
+
+async def service_stop(service_name : str) -> bool:
+    cmd = ["systemctl", "stop", service_name]
+    res = run(cmd, stdout=PIPE, stderr=STDOUT)
+    return res.returncode == 0
+
+async def service_start(service_name : str) -> bool:
+    cmd = ["systemctl", "start", service_name]
+    res = run(cmd, stdout=PIPE, stderr=STDOUT)
+    return res.returncode == 0
+
+def get_privileged_path() -> str:
+    path = os.getenv("PRIVILEGED_PATH")
+
+    if path == None:
+        path = get_unprivileged_path()
+
+    return path
+
+def _parent_dir(path : str | None) -> str | None:
+    if path == None:
+        return None
+
+    if path.endswith('/'):
+        path = path[:-1]
+    
+    return os.path.dirname(path)
+
+def get_unprivileged_path() -> str:
+    path = os.getenv("UNPRIVILEGED_PATH")
+    
+    if path == None:
+        path = _parent_dir(os.getenv("PLUGIN_PATH"))
+    
+    if path == None:
+        logger.debug("Unprivileged path is not properly configured. Making something up!")
+        # Expected path of loader binary is /home/deck/homebrew/service/PluginLoader
+        path = _parent_dir(_parent_dir(os.path.realpath(sys.argv[0])))
+
+        if path != None and not os.path.exists(path):
+            path = None
+
+    if path == None:
+        logger.warn("Unprivileged path is not properly configured. Defaulting to /home/deck/homebrew")
+        path = "/home/deck/homebrew" # We give up
+    
+    return path
+
+
+def get_unprivileged_user() -> str:
+    user = os.getenv("UNPRIVILEGED_USER")
+
+    if user == None:
+        # Lets hope we can extract it from the unprivileged dir
+        dir = os.path.realpath(get_unprivileged_path())
+
+        pws = sorted(pwd.getpwall(), reverse=True, key=lambda pw: len(pw.pw_dir))
+        for pw in pws:
+            if dir.startswith(os.path.realpath(pw.pw_dir)):
+                user = pw.pw_name
+                break
+    
+    if user == None:
+        logger.warn("Unprivileged user is not properly configured. Defaulting to 'deck'")
+        user = 'deck'
+
+    return user
diff --git a/backend/src/localplatform/localplatformwin.py b/backend/src/localplatform/localplatformwin.py
new file mode 100644
index 00000000..4c4e9439
--- /dev/null
+++ b/backend/src/localplatform/localplatformwin.py
@@ -0,0 +1,53 @@
+from .customtypes import UserType
+import os, sys
+
+def chown(path : str,  user : UserType = UserType.HOST_USER, recursive : bool = True) -> bool:
+    return True # Stubbed
+
+def chmod(path : str, permissions : int, recursive : bool = True) -> bool:
+    return True # Stubbed
+
+def folder_owner(path : str) -> UserType|None:
+    return UserType.HOST_USER # Stubbed
+
+def get_home_path(user : UserType = UserType.HOST_USER) -> str:
+    return os.path.expanduser("~") # Mostly stubbed
+
+def setgid(user : UserType = UserType.HOST_USER):
+    pass # Stubbed
+
+def setuid(user : UserType = UserType.HOST_USER):
+    pass # Stubbed
+
+async def service_active(service_name : str) -> bool:
+    return True # Stubbed
+
+async def service_stop(service_name : str) -> bool:
+    return True # Stubbed
+
+async def service_start(service_name : str) -> bool:
+    return True # Stubbed
+
+async def service_restart(service_name : str) -> bool:
+    if service_name == "plugin_loader":
+        sys.exit(42)
+
+    return True # Stubbed
+
+def get_username() -> str:
+    return os.getlogin()
+
+def get_privileged_path() -> str:
+    '''On windows, privileged_path is equal to unprivileged_path'''
+    return get_unprivileged_path()
+
+def get_unprivileged_path() -> str:
+    path = os.getenv("UNPRIVILEGED_PATH")
+
+    if path == None:
+        path = os.getenv("PRIVILEGED_PATH", os.path.join(os.path.expanduser("~"), "homebrew"))
+
+    return path
+
+def get_unprivileged_user() -> str:
+    return os.getenv("UNPRIVILEGED_USER", os.getlogin())
diff --git a/backend/src/localplatform/localsocket.py b/backend/src/localplatform/localsocket.py
new file mode 100644
index 00000000..f38fe5e7
--- /dev/null
+++ b/backend/src/localplatform/localsocket.py
@@ -0,0 +1,139 @@
+import asyncio, time
+from typing import Awaitable, Callable
+import random
+
+from .localplatform import ON_WINDOWS
+
+BUFFER_LIMIT = 2 ** 20  # 1 MiB
+
+class UnixSocket:
+    def __init__(self, on_new_message: Callable[[str], Awaitable[str|None]]):
+        '''
+        on_new_message takes 1 string argument.
+        It's return value gets used, if not None, to write data to the socket.
+        Method should be async
+        '''
+        self.socket_addr = f"/tmp/plugin_socket_{time.time()}"
+        self.on_new_message = on_new_message
+        self.socket = None
+        self.reader = None
+        self.writer = None
+
+    async def setup_server(self):
+        self.socket = await asyncio.start_unix_server(self._listen_for_method_call, path=self.socket_addr, limit=BUFFER_LIMIT)
+    
+    async def _open_socket_if_not_exists(self):
+        if not self.reader:
+            retries = 0
+            while retries < 10:
+                try:
+                    self.reader, self.writer = await asyncio.open_unix_connection(self.socket_addr, limit=BUFFER_LIMIT)
+                    return True
+                except:
+                    await asyncio.sleep(2)
+                    retries += 1
+            return False
+        else:
+            return True
+
+    async def get_socket_connection(self):
+        if not await self._open_socket_if_not_exists():
+            return None, None
+        
+        return self.reader, self.writer
+    
+    async def close_socket_connection(self):
+        if self.writer != None:
+            self.writer.close()
+
+        self.reader = None
+
+    async def read_single_line(self) -> str|None:
+        reader, _ = await self.get_socket_connection()
+
+        try:
+            assert reader
+        except AssertionError:
+            return
+
+        return await self._read_single_line(reader)
+
+    async def write_single_line(self, message : str):
+        _, writer = await self.get_socket_connection()
+
+        try:
+            assert writer
+        except AssertionError:
+            return
+
+        await self._write_single_line(writer, message)
+
+    async def _read_single_line(self, reader: asyncio.StreamReader) -> str:
+        line = bytearray()
+        while True:
+            try:
+                line.extend(await reader.readuntil())
+            except asyncio.LimitOverrunError:
+                line.extend(await reader.read(reader._limit)) # type: ignore
+                continue
+            except asyncio.IncompleteReadError as err:
+                line.extend(err.partial)
+                break
+            else:
+                break
+
+        return line.decode("utf-8")
+    
+    async def _write_single_line(self, writer: asyncio.StreamWriter, message : str):
+        if not message.endswith("\n"):
+            message += "\n"
+
+        writer.write(message.encode("utf-8"))
+        await writer.drain()
+
+    async def _listen_for_method_call(self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter):
+        while True:
+            line = await self._read_single_line(reader)
+
+            try:
+                res = await self.on_new_message(line)
+            except Exception:
+                return
+
+            if res != None:
+                await self._write_single_line(writer, res)
+            
+class PortSocket (UnixSocket):
+    def __init__(self, on_new_message: Callable[[str], Awaitable[str|None]]):
+        '''
+        on_new_message takes 1 string argument.
+        It's return value gets used, if not None, to write data to the socket.
+        Method should be async
+        '''
+        super().__init__(on_new_message)
+        self.host = "127.0.0.1"
+        self.port = random.sample(range(40000, 60000), 1)[0]
+    
+    async def setup_server(self):
+        self.socket = await asyncio.start_server(self._listen_for_method_call, host=self.host, port=self.port, limit=BUFFER_LIMIT)
+    
+    async def _open_socket_if_not_exists(self):
+        if not self.reader:
+            retries = 0
+            while retries < 10:
+                try:
+                    self.reader, self.writer = await asyncio.open_connection(host=self.host, port=self.port, limit=BUFFER_LIMIT)
+                    return True
+                except:
+                    await asyncio.sleep(2)
+                    retries += 1
+            return False
+        else:
+            return True
+
+if ON_WINDOWS:
+    class LocalSocket (PortSocket):  # type: ignore
+        pass
+else:
+    class LocalSocket (UnixSocket):
+        pass
\ No newline at end of file