One-KVM/kvmd/plugins/msd/relay.py
2020-09-14 01:34:23 +03:00

425 lines
14 KiB
Python

# ========================================================================== #
# #
# KVMD - The main Pi-KVM daemon. #
# #
# Copyright (C) 2018 Maxim Devaev <mdevaev@gmail.com> #
# #
# This program is free software: you can redistribute it and/or modify #
# it under the terms of the GNU General Public License as published by #
# the Free Software Foundation, either version 3 of the License, or #
# (at your option) any later version. #
# #
# This program is distributed in the hope that it will be useful, #
# but WITHOUT ANY WARRANTY; without even the implied warranty of #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
# GNU General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with this program. If not, see <https://www.gnu.org/licenses/>. #
# #
# ========================================================================== #
import os
import stat
import fcntl
import struct
import asyncio
import contextlib
import dataclasses
from typing import Dict
from typing import IO
from typing import AsyncGenerator
from typing import Optional
import aiofiles
import aiofiles.base
import gpiod
from ...logging import get_logger
from ... import aiotools
from ... import aiofs
from ... import aiogp
from ...yamlconf import Option
from ...validators.basic import valid_int_f1
from ...validators.basic import valid_float_f01
from ...validators.os import valid_abs_path
from ...validators.hw import valid_gpio_pin
from . import MsdError
from . import MsdIsBusyError
from . import MsdOfflineError
from . import MsdConnectedError
from . import MsdDisconnectedError
from . import MsdMultiNotSupported
from . import MsdCdromNotSupported
from . import BaseMsd
# =====
@dataclasses.dataclass(frozen=True)
class _ImageInfo:
name: str
size: int
complete: bool
@dataclasses.dataclass(frozen=True)
class _DeviceInfo:
path: str
size: int
free: int
image: Optional[_ImageInfo]
_IMAGE_INFO_SIZE = 4096
_IMAGE_INFO_MAGIC_SIZE = 16
_IMAGE_INFO_NAME_SIZE = 256
_IMAGE_INFO_PADS_SIZE = _IMAGE_INFO_SIZE - _IMAGE_INFO_NAME_SIZE - 1 - 8 - _IMAGE_INFO_MAGIC_SIZE * 8
_IMAGE_INFO_FORMAT = ">%dL%dc?Q%dx%dL" % (
_IMAGE_INFO_MAGIC_SIZE,
_IMAGE_INFO_NAME_SIZE,
_IMAGE_INFO_PADS_SIZE,
_IMAGE_INFO_MAGIC_SIZE,
)
_IMAGE_INFO_MAGIC = [0x1ACE1ACE] * _IMAGE_INFO_MAGIC_SIZE
def _make_image_info_bytes(name: str, size: int, complete: bool) -> bytes:
return struct.pack(
_IMAGE_INFO_FORMAT,
*_IMAGE_INFO_MAGIC,
*memoryview(( # type: ignore
name.encode("utf-8")
+ b"\x00" * _IMAGE_INFO_NAME_SIZE
)[:_IMAGE_INFO_NAME_SIZE]).cast("c"),
complete,
size,
*_IMAGE_INFO_MAGIC,
)
def _parse_image_info_bytes(data: bytes) -> Optional[_ImageInfo]:
try:
parsed = list(struct.unpack(_IMAGE_INFO_FORMAT, data))
except struct.error:
pass
else:
magic_begin = parsed[:_IMAGE_INFO_MAGIC_SIZE]
magic_end = parsed[-_IMAGE_INFO_MAGIC_SIZE:]
if magic_begin == magic_end == _IMAGE_INFO_MAGIC:
image_name_bytes = b"".join(parsed[
_IMAGE_INFO_MAGIC_SIZE # noqa: E203
:
_IMAGE_INFO_MAGIC_SIZE + _IMAGE_INFO_NAME_SIZE
])
return _ImageInfo(
name=image_name_bytes.decode("utf-8", errors="ignore").strip("\x00").strip(),
size=parsed[_IMAGE_INFO_MAGIC_SIZE + _IMAGE_INFO_NAME_SIZE + 1],
complete=parsed[_IMAGE_INFO_MAGIC_SIZE + _IMAGE_INFO_NAME_SIZE],
)
return None
def _ioctl_uint32(device_file: IO, request: int) -> int:
buf = b"\0" * 4
buf = fcntl.ioctl(device_file.fileno(), request, buf) # type: ignore
result = struct.unpack("I", buf)[0]
assert result > 0, (device_file, request, buf)
return result
def _explore_device(device_path: str) -> _DeviceInfo:
if not stat.S_ISBLK(os.stat(device_path).st_mode):
raise RuntimeError(f"Not a block device: {device_path}")
with open(device_path, "rb") as device_file:
# size = BLKGETSIZE * BLKSSZGET
size = _ioctl_uint32(device_file, 0x1260) * _ioctl_uint32(device_file, 0x1268)
device_file.seek(size - _IMAGE_INFO_SIZE)
image_info = _parse_image_info_bytes(device_file.read())
return _DeviceInfo(
path=device_path,
size=size,
free=(size - image_info.size if image_info else size),
image=image_info,
)
class _Gpio:
def __init__(
self,
target_pin: int,
reset_pin: int,
reset_delay: float,
) -> None:
self.__target_pin = target_pin
self.__reset_pin = reset_pin
self.__reset_delay = reset_delay
self.__chip: Optional[gpiod.Chip] = None
self.__target_line: Optional[gpiod.Line] = None
self.__reset_line: Optional[gpiod.Line] = None
def open(self) -> None:
assert self.__chip is None
assert self.__target_line is None
assert self.__reset_line is None
self.__chip = gpiod.Chip(aiogp.DEVICE_PATH)
self.__target_line = self.__chip.get_line(self.__target_pin)
self.__target_line.request("kvmd/msd-relay/target", gpiod.LINE_REQ_DIR_OUT, default_val=0)
self.__reset_line = self.__chip.get_line(self.__reset_pin)
self.__reset_line.request("kvmd/msd-relay/reset", gpiod.LINE_REQ_DIR_OUT, default_val=0)
def close(self) -> None:
if self.__chip:
try:
self.__chip.close()
except Exception:
pass
def switch_to_local(self) -> None:
assert self.__target_line
self.__target_line.set_value(0)
def switch_to_server(self) -> None:
assert self.__target_line
self.__target_line.set_value(1)
async def reset(self) -> None:
assert self.__reset_line
await aiogp.pulse(self.__reset_line, self.__reset_delay, 0)
# =====
class Plugin(BaseMsd): # pylint: disable=too-many-instance-attributes
def __init__( # pylint: disable=super-init-not-called
self,
target_pin: int,
reset_pin: int,
device_path: str,
init_delay: float,
init_retries: int,
reset_delay: float,
) -> None:
self.__device_path = device_path
self.__init_delay = init_delay
self.__init_retries = init_retries
self.__gpio = _Gpio(target_pin, reset_pin, reset_delay)
self.__device_info: Optional[_DeviceInfo] = None
self.__connected = False
self.__device_file: Optional[aiofiles.base.AiofilesContextManager] = None
self.__written = 0
self.__notifier = aiotools.AioNotifier()
self.__region = aiotools.AioExclusiveRegion(MsdIsBusyError, self.__notifier)
logger = get_logger(0)
logger.info("Using %r as MSD", self.__device_path)
try:
aiotools.run_sync(self.__load_device_info())
except Exception as err:
log = (logger.error if isinstance(err, MsdError) else logger.exception)
log("MSD is offline: %s", err)
@classmethod
def get_plugin_options(cls) -> Dict:
return {
"target_pin": Option(-1, type=valid_gpio_pin),
"reset_pin": Option(-1, type=valid_gpio_pin),
"device": Option("", type=valid_abs_path, unpack_as="device_path"),
"init_delay": Option(1.0, type=valid_float_f01),
"init_retries": Option(5, type=valid_int_f1),
"reset_delay": Option(1.0, type=valid_float_f01),
}
def sysprep(self) -> None:
self.__gpio.open()
async def get_state(self) -> Dict:
storage: Optional[Dict] = None
drive: Optional[Dict] = None
if self.__device_info:
storage = {
"size": self.__device_info.size,
"free": self.__device_info.free,
"uploading": bool(self.__device_file)
}
drive = {
"image": (self.__device_info.image and dataclasses.asdict(self.__device_info.image)),
"connected": self.__connected,
}
return {
"enabled": True,
"online": bool(self.__device_info),
"busy": self.__region.is_busy(),
"storage": storage,
"drive": drive,
"features": {
"multi": False,
"cdrom": False,
},
}
async def poll_state(self) -> AsyncGenerator[Dict, None]:
prev_state: Dict = {}
while True:
state = await self.get_state()
if state != prev_state:
yield state
prev_state = state
await self.__notifier.wait()
@aiotools.atomic
async def reset(self) -> None:
await aiotools.run_region_task(
"Can't reset MSD or operation was not completed",
self.__region, self.__inner_reset,
)
@aiotools.atomic
async def __inner_reset(self) -> None:
await self.__gpio.reset()
self.__gpio.switch_to_local()
self.__connected = False
await self.__load_device_info()
get_logger(0).info("MSD reset has been successful")
@aiotools.atomic
async def cleanup(self) -> None:
try:
await self.__close_device_file()
finally:
self.__gpio.close()
# =====
@aiotools.atomic
async def set_params(self, name: Optional[str]=None, cdrom: Optional[bool]=None) -> None:
async with self.__working():
if name is not None:
raise MsdMultiNotSupported()
if cdrom is not None:
raise MsdCdromNotSupported()
@aiotools.atomic
async def connect(self) -> None:
async with self.__working():
async with self.__region:
if self.__connected:
raise MsdConnectedError()
self.__gpio.switch_to_server()
self.__connected = True
get_logger(0).info("MSD switched to Server")
@aiotools.atomic
async def disconnect(self) -> None:
async with self.__working():
async with self.__region:
if not self.__connected:
raise MsdDisconnectedError()
self.__gpio.switch_to_local()
try:
await self.__load_device_info()
except Exception:
if self.__connected:
self.__gpio.switch_to_server()
raise
self.__connected = False
get_logger(0).info("MSD switched to KVM: %s", self.__device_info)
@contextlib.asynccontextmanager
async def write_image(self, name: str) -> AsyncGenerator[None, None]:
async with self.__working():
async with self.__region:
try:
assert self.__device_info
if self.__connected:
raise MsdConnectedError()
self.__device_file = await aiofiles.open(self.__device_info.path, mode="w+b", buffering=0)
self.__written = 0
await self.__write_image_info(name, complete=False)
await self.__notifier.notify()
yield
await self.__write_image_info(name, complete=True)
finally:
await self.__close_device_file()
await self.__load_device_info()
async def write_image_chunk(self, chunk: bytes) -> int:
assert self.__device_file
await aiofs.afile_write_now(self.__device_file, chunk)
self.__written += len(chunk)
return self.__written
@aiotools.atomic
async def remove(self, name: str) -> None:
async with self.__working():
raise MsdMultiNotSupported()
# =====
@contextlib.asynccontextmanager
async def __working(self) -> AsyncGenerator[None, None]:
if not self.__device_info:
raise MsdOfflineError()
yield
# =====
async def __write_image_info(self, name: str, complete: bool) -> None:
assert self.__device_file
assert self.__device_info
if self.__device_info.size - self.__written > _IMAGE_INFO_SIZE:
await self.__device_file.seek(self.__device_info.size - _IMAGE_INFO_SIZE)
await aiofs.afile_write_now(self.__device_file, _make_image_info_bytes(name, self.__written, complete))
await self.__device_file.seek(0)
else:
get_logger().error("Can't write image info because device is full")
async def __close_device_file(self) -> None:
try:
if self.__device_file:
get_logger().info("Closing device file ...")
await self.__device_file.close()
except Exception:
get_logger().exception("Can't close device file")
finally:
self.__device_file = None
self.__written = 0
async def __load_device_info(self) -> None:
retries = self.__init_retries
while True:
await asyncio.sleep(self.__init_delay)
try:
self.__device_info = await aiotools.run_async(_explore_device, self.__device_path)
break
except Exception:
if retries == 0:
self.__device_info = None
raise MsdError("Can't load device info")
get_logger().exception("Can't load device info; retries=%d", retries)
retries -= 1