2019-03-18 03:32:14 +03:00

386 lines
13 KiB
Python

# ========================================================================== #
# #
# KVMD - The 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 struct
import asyncio
import asyncio.queues
import types
from typing import Dict
from typing import NamedTuple
from typing import Callable
from typing import Type
from typing import AsyncGenerator
from typing import Optional
from typing import Any
import pyudev
import aiofiles
import aiofiles.base
from ...logging import get_logger
from ... import aioregion
from ... import gpio
# =====
class MsdError(Exception):
pass
class MsdOperationError(MsdError):
pass
class MsdDisabledError(MsdOperationError):
def __init__(self) -> None:
super().__init__("Mass-storage device is disabled")
class MsdOfflineError(MsdOperationError):
def __init__(self) -> None:
super().__init__("Mass-storage device is not found")
class MsdAlreadyConnectedToPcError(MsdOperationError):
def __init__(self) -> None:
super().__init__("Mass-storage is already connected to Server")
class MsdAlreadyConnectedToKvmError(MsdOperationError):
def __init__(self) -> None:
super().__init__("Mass-storage is already connected to KVM")
class MsdNotConnectedToKvmError(MsdOperationError):
def __init__(self) -> None:
super().__init__("Mass-storage is not connected to KVM")
class MsdIsBusyError(MsdOperationError, aioregion.RegionIsBusyError):
pass
# =====
class _HardwareInfo(NamedTuple):
manufacturer: str
product: str
serial: str
class _ImageInfo(NamedTuple):
name: str
size: int
complete: bool
class _MassStorageDeviceInfo(NamedTuple):
path: str
real: str
size: int
hw: Optional[_HardwareInfo]
image: Optional[_ImageInfo]
_IMAGE_INFO_SIZE = 4096
_IMAGE_INFO_MAGIC_SIZE = 16
_IMAGE_INFO_IMAGE_NAME_SIZE = 256
_IMAGE_INFO_PADS_SIZE = _IMAGE_INFO_SIZE - _IMAGE_INFO_IMAGE_NAME_SIZE - 1 - 8 - _IMAGE_INFO_MAGIC_SIZE * 8
_IMAGE_INFO_FORMAT = ">%dL%dc?Q%dx%dL" % (
_IMAGE_INFO_MAGIC_SIZE,
_IMAGE_INFO_IMAGE_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_IMAGE_NAME_SIZE
)[:_IMAGE_INFO_IMAGE_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:_IMAGE_INFO_MAGIC_SIZE + _IMAGE_INFO_IMAGE_NAME_SIZE])
return _ImageInfo(
name=image_name_bytes.decode("utf-8", errors="ignore").strip("\x00").strip(),
size=parsed[_IMAGE_INFO_MAGIC_SIZE + _IMAGE_INFO_IMAGE_NAME_SIZE + 1],
complete=parsed[_IMAGE_INFO_MAGIC_SIZE + _IMAGE_INFO_IMAGE_NAME_SIZE],
)
return None
def _explore_device(device_path: str) -> Optional[_MassStorageDeviceInfo]:
# udevadm info -a -p $(udevadm info -q path -n /dev/sda)
ctx = pyudev.Context()
device = pyudev.Devices.from_device_file(ctx, device_path)
if device.subsystem != "block":
return None
try:
size = device.attributes.asint("size") * 512
except KeyError:
return None
hw_info: Optional[_HardwareInfo] = None
usb_device = device.find_parent("usb", "usb_device")
if usb_device:
hw_info = _HardwareInfo(**{
attr: usb_device.attributes.asstring(attr).strip()
for attr in ["manufacturer", "product", "serial"]
})
with open(device_path, "rb") as device_file:
device_file.seek(size - _IMAGE_INFO_SIZE)
image_info = _parse_image_info_bytes(device_file.read())
return _MassStorageDeviceInfo(
path=device_path,
real=os.path.realpath(device_path),
size=size,
image=image_info,
hw=hw_info,
)
def _msd_working(method: Callable) -> Callable:
async def wrap(self: "MassStorageDevice", *args: Any, **kwargs: Any) -> Any:
if not self._enabled: # pylint: disable=protected-access
raise MsdDisabledError()
if not self._device_path: # pylint: disable=protected-access
raise MsdOfflineError()
return (await method(self, *args, **kwargs))
return wrap
# =====
class MassStorageDevice: # pylint: disable=too-many-instance-attributes
def __init__(
self,
enabled: bool,
target_pin: int,
reset_pin: int,
device_path: str,
init_delay: float,
reset_delay: float,
write_meta: bool,
chunk_size: int,
loop: asyncio.AbstractEventLoop,
) -> None:
self._enabled = enabled
if self._enabled:
self.__target_pin = gpio.set_output(target_pin)
self.__reset_pin = gpio.set_output(reset_pin)
assert bool(device_path)
else:
self.__target_pin = -1
self.__reset_pin = -1
self._device_path = device_path
self.__init_delay = init_delay
self.__reset_delay = reset_delay
self.__write_meta = write_meta
self.chunk_size = chunk_size
self.__loop = loop
self.__device_info: Optional[_MassStorageDeviceInfo] = None
self.__saved_device_info: Optional[_MassStorageDeviceInfo] = None
self.__region = aioregion.AioExclusiveRegion(MsdIsBusyError)
self.__device_file: Optional[aiofiles.base.AiofilesContextManager] = None
self.__written = 0
self.__state_queue: asyncio.queues.Queue = asyncio.Queue()
logger = get_logger(0)
if self._enabled:
logger.info("Using %r as mass-storage device", self._device_path)
try:
logger.info("Enabled image metadata writing")
loop.run_until_complete(self.connect_to_kvm(no_delay=True))
except Exception as err:
if isinstance(err, MsdError):
log = logger.error
else:
log = logger.exception
log("Mass-storage device is offline: %s", err)
self._device_path = ""
else:
logger.info("Mass-storage device is disabled")
def get_state(self) -> Dict:
info = (self.__saved_device_info._asdict() if self.__saved_device_info else None)
if info:
info["hw"] = (info["hw"]._asdict() if info["hw"] else None)
info["image"] = (info["image"]._asdict() if info["image"] else None)
connected_to: Optional[str] = None
if self._enabled and self._device_path:
connected_to = ("kvm" if self.__device_info else "server")
return {
"enabled": self._enabled,
"online": (self._enabled and bool(self._device_path)),
"connected_to": connected_to,
"busy": bool(self.__device_file),
"written": self.__written,
"info": info,
}
async def poll_state(self) -> AsyncGenerator[Dict, None]:
while True:
if self._enabled:
yield (await self.__state_queue.get())
else:
await asyncio.sleep(60)
async def cleanup(self) -> None:
if self._enabled:
await self.__close_device_file()
gpio.write(self.__target_pin, False)
gpio.write(self.__reset_pin, False)
@_msd_working
async def connect_to_kvm(self, no_delay: bool=False) -> Dict:
with self.__region:
if self.__device_info:
raise MsdAlreadyConnectedToKvmError()
gpio.write(self.__target_pin, False)
if not no_delay:
await asyncio.sleep(self.__init_delay)
await self.__load_device_info()
state = self.get_state()
await self.__state_queue.put(state)
get_logger().info("Mass-storage device switched to KVM: %s", self.__device_info)
return state
@_msd_working
async def connect_to_pc(self) -> Dict:
with self.__region:
if not self.__device_info:
raise MsdAlreadyConnectedToPcError()
gpio.write(self.__target_pin, True)
self.__device_info = None
state = self.get_state()
await self.__state_queue.put(state)
get_logger().info("Mass-storage device switched to Server")
return state
@_msd_working
async def reset(self) -> None:
with self.__region:
get_logger().info("Mass-storage device reset")
gpio.write(self.__reset_pin, True)
await asyncio.sleep(self.__reset_delay)
gpio.write(self.__reset_pin, False)
await self.__state_queue.put(self.get_state())
@_msd_working
async def __aenter__(self) -> "MassStorageDevice":
self.__region.enter()
try:
if not self.__device_info:
raise MsdNotConnectedToKvmError()
self.__device_file = await aiofiles.open(self.__device_info.path, mode="w+b", buffering=0)
self.__written = 0
return self
finally:
await self.__state_queue.put(self.get_state())
self.__region.exit()
async def write_image_info(self, name: str, complete: bool) -> None:
assert self.__device_file
assert self.__device_info
if self.__write_meta:
if self.__device_info.size - self.__written > _IMAGE_INFO_SIZE:
await self.__device_file.seek(self.__device_info.size - _IMAGE_INFO_SIZE)
await self.__write_to_device_file(_make_image_info_bytes(name, self.__written, complete))
await self.__device_file.seek(0)
await self.__load_device_info()
else:
get_logger().error("Can't write image info because device is full")
async def write_image_chunk(self, chunk: bytes) -> int:
await self.__write_to_device_file(chunk)
self.__written += len(chunk)
return self.__written
async def __aexit__(
self,
_exc_type: Type[BaseException],
_exc: BaseException,
_tb: types.TracebackType,
) -> None:
try:
await self.__close_device_file()
finally:
await self.__state_queue.put(self.get_state())
self.__region.exit()
async def __write_to_device_file(self, data: bytes) -> None:
assert self.__device_file
await self.__device_file.write(data)
await self.__device_file.flush()
await self.__loop.run_in_executor(None, os.fsync, self.__device_file.fileno())
async def __load_device_info(self) -> None:
device_info = await self.__loop.run_in_executor(None, _explore_device, self._device_path)
if not device_info:
raise MsdError("Can't explore device %r" % (self._device_path))
self.__device_info = self.__saved_device_info = device_info
async def __close_device_file(self) -> None:
try:
if self.__device_file:
get_logger().info("Closing mass-storage device file ...")
await self.__device_file.close()
except Exception:
get_logger().exception("Can't close mass-storage device file")
await self.reset()
self.__device_file = None
self.__written = 0