# Copyright (c) 2016-2023 by Ron Frederick <ronf@timeheart.net> and others.
#
# This program and the accompanying materials are made available under
# the terms of the Eclipse Public License v2.0 which accompanies this
# distribution and is available at:
#
# http://www.eclipse.org/legal/epl-2.0/
#
# This program may also be made available under the following secondary
# licenses when the conditions for such availability set forth in the
# Eclipse Public License v2.0 are satisfied:
#
# GNU General Public License, Version 2.0, or any later versions of
# that license
#
# SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
#
# Contributors:
# Ron Frederick - initial implementation, API, and documentation
"""SSH process handlers"""
import asyncio
from asyncio.subprocess import DEVNULL, PIPE, STDOUT
import codecs
import inspect
import io
import os
from pathlib import PurePath
import socket
import stat
from types import TracebackType
from typing import Any, AnyStr, Awaitable, Callable, Dict, Generic, IO
from typing import Iterable, List, Mapping, Optional, Set, TextIO
from typing import Tuple, Type, TypeVar, Union, cast
from typing_extensions import Protocol
from .channel import SSHChannel, SSHClientChannel, SSHServerChannel
from .constants import DEFAULT_LANG, EXTENDED_DATA_STDERR
from .logging import SSHLogger
from .misc import BytesOrStr, Error, MaybeAwait
from .misc import ProtocolError, Record, open_file
from .misc import BreakReceived, SignalReceived, TerminalSizeChanged
from .session import DataType, TermModes, TermSize
from .stream import SSHReader, SSHWriter, SSHStreamSession
from .stream import SSHClientStreamSession, SSHServerStreamSession
from .stream import SFTPServerFactory
_AnyStrContra = TypeVar('_AnyStrContra', bytes, str, contravariant=True)
_File = Union[IO[bytes], '_AsyncFileProtocol[bytes]']
ProcessSource = Union[int, str, socket.socket, PurePath, SSHReader[bytes],
asyncio.StreamReader, _File]
ProcessTarget = Union[int, str, socket.socket, PurePath, SSHWriter[bytes],
asyncio.StreamWriter, _File]
SSHServerProcessFactory = Callable[['SSHServerProcess[AnyStr]'],
MaybeAwait[None]]
class _AsyncFileProtocol(Protocol[AnyStr]):
"""Protocol for an async file"""
async def read(self, n: int = -1) -> AnyStr:
"""Read from an async file"""
async def write(self, data: AnyStr) -> None:
"""Write to an async file"""
async def close(self) -> None:
"""Close an async file"""
class _ReaderProtocol(Protocol):
"""A class that can be used as a reader in SSHProcess"""
def pause_reading(self) -> None:
"""Pause reading"""
def resume_reading(self) -> None:
"""Resume reading"""
def close(self) -> None:
"""Stop forwarding data"""
class _WriterProtocol(Protocol[_AnyStrContra]):
"""A class that can be used as a writer in SSHProcess"""
def write(self, data: _AnyStrContra) -> None:
"""Write data"""
def write_exception(self, exc: Exception) -> None:
"""Write exception (break, signal, terminal size change)"""
return # pragma: no cover
def write_eof(self) -> None:
"""Close output when end of file is received"""
def close(self) -> None:
"""Stop forwarding data"""
def _is_regular_file(file: IO[bytes]) -> bool:
"""Return if argument is a regular file or file-like object"""
try:
return stat.S_ISREG(os.fstat(file.fileno()).st_mode)
except OSError:
return True
class _UnicodeReader(_ReaderProtocol, Generic[AnyStr]):
"""Handle buffering partial Unicode data"""
def __init__(self, encoding: Optional[str], errors: str,
textmode: bool = False):
super().__init__()
if encoding and not textmode:
self._decoder: Optional[codecs.IncrementalDecoder] = \
codecs.getincrementaldecoder(encoding)(errors)
else:
self._decoder = None
def decode(self, data: bytes, final: bool = False) -> AnyStr:
"""Decode Unicode bytes when reading from binary sources"""
if self._decoder:
try:
decoded_data = cast(AnyStr, self._decoder.decode(data, final))
except UnicodeDecodeError as exc:
raise ProtocolError(str(exc)) from None
else:
decoded_data = cast(AnyStr, data)
return decoded_data
def check_partial(self) -> None:
"""Check if there's partial Unicode data left at EOF"""
self.decode(b'', True)
def close(self) -> None:
"""Perform necessary cleanup on error (provided by derived classes)"""
class _UnicodeWriter(_WriterProtocol[AnyStr]):
"""Handle encoding Unicode data before writing it"""
def __init__(self, encoding: Optional[str], errors: str,
textmode: bool = False):
super().__init__()
if encoding and not textmode:
self._encoder: Optional[codecs.IncrementalEncoder] = \
codecs.getincrementalencoder(encoding)(errors)
else:
self._encoder = None
def encode(self, data: AnyStr) -> bytes:
"""Encode Unicode bytes when writing to binary targets"""
if self._encoder:
assert self._encoder is not None
encoded_data = cast(bytes, self._encoder.encode(cast(str, data)))
else:
encoded_data = cast(bytes, data)
return encoded_data
class _FileReader(_UnicodeReader[AnyStr]):
"""Forward data from a file"""
def __init__(self, process: 'SSHProcess[AnyStr]', file: IO[bytes],
bufsize: int, datatype: DataType,
encoding: Optional[str], errors: str):
super().__init__(encoding, errors, hasattr(file, 'encoding'))
self._process: 'SSHProcess[AnyStr]' = process
self._file = file
self._bufsize = bufsize
self._datatype = datatype
self._paused = False
def feed(self) -> None:
"""Feed file data"""
while not self._paused:
data = self._file.read(self._bufsize)
if data:
self._process.feed_data(self.decode(data), self._datatype)
else:
self.check_partial()
self._process.feed_eof(self._datatype)
break
def pause_reading(self) -> None:
"""Pause reading from the file"""
self._paused = True
def resume_reading(self) -> None:
"""Resume reading from the file"""
self._paused = False
self.feed()
def close(self) -> None:
"""Stop forwarding data from the file"""
self._file.close()
class _AsyncFileReader(_UnicodeReader[AnyStr]):
"""Forward data from an aiofile"""
def __init__(self, process: 'SSHProcess[AnyStr]',
file: _AsyncFileProtocol[bytes],
bufsize: int, datatype: DataType,
encoding: Optional[str], errors: str):
super().__init__(encoding, errors, hasattr(file, 'encoding'))
self._conn = process.channel.get_connection()
self._process: 'SSHProcess[AnyStr]' = process
self._file = file
self._bufsize = bufsize
self._datatype = datatype
self._paused = False
async def _feed(self) -> None:
"""Feed file data"""
while not self._paused:
data = await self._file.read(self._bufsize)
if data:
self._process.feed_data(self.decode(data), self._datatype)
else:
self.check_partial()
self._process.feed_eof(self._datatype)
break
def feed(self) -> None:
"""Start feeding file data"""
self._conn.create_task(self._feed())
def pause_reading(self) -> None:
"""Pause reading from the file"""
self._paused = True
def resume_reading(self) -> None:
"""Resume reading from the file"""
self._paused = False
self.feed()
def close(self) -> None:
"""Stop forwarding data from the file"""
self._conn.create_task(self._file.close())
class _FileWriter(_UnicodeWriter[AnyStr]):
"""Forward data to a file"""
def __init__(self, file: IO[bytes], needs_close: bool,
encoding: Optional[str], errors: str):
super().__init__(encoding, errors, hasattr(file, 'encoding'))
self._file = file
self._needs_close = needs_close
def write(self, data: AnyStr) -> None:
"""Write data to the file"""
self._file.write(self.encode(data))
def write_eof(self) -> None:
"""Close output file when end of file is received"""
self.close()
def close(self) -> None:
"""Stop forwarding data to the file"""
if self._needs_close:
self._file.close()
class _AsyncFileWriter(_UnicodeWriter[AnyStr]):
"""Forward data to an aiofile"""
def __init__(self, process: 'SSHProcess[AnyStr]',
file: _AsyncFileProtocol[bytes], needs_close: bool,
encoding: Optional[str], errors: str):
super().__init__(encoding, errors, hasattr(file, 'encoding'))
self._process: 'SSHProcess[AnyStr]' = process
self._file = file
self._needs_close = needs_close
self._queue: asyncio.Queue[Optional[AnyStr]] = asyncio.Queue()
self._write_task: Optional[asyncio.Task[None]] = \
process.channel.get_connection().create_task(self._writer())
async def _writer(self) -> None:
"""Process writes to the file"""
while True:
data = await self._queue.get()
if data is None:
self._queue.task_done()
break
await self._file.write(self.encode(data))
self._queue.task_done()
if self._needs_close:
await self._file.close()
def write(self, data: AnyStr) -> None:
"""Write data to the file"""
self._queue.put_nowait(data)
def write_eof(self) -> None:
"""Close output file when end of file is received"""
self.close()
def close(self) -> None:
"""Stop forwarding data to the file"""
if self._write_task:
self._write_task = None
self._queue.put_nowait(None)
self._process.add_cleanup_task(self._queue.join())
class _PipeReader(_UnicodeReader[AnyStr], asyncio.BaseProtocol):
"""Forward data from a pipe"""
def __init__(self, process: 'SSHProcess[AnyStr]', datatype: DataType,
encoding: Optional[str], errors: str):
super().__init__(encoding, errors)
self._process: 'SSHProcess[AnyStr]' = process
self._datatype = datatype
self._transport: Optional[asyncio.ReadTransport] = None
def connection_made(self, transport: asyncio.BaseTransport) -> None:
"""Handle a newly opened pipe"""
self._transport = cast(asyncio.ReadTransport, transport)
def data_received(self, data: bytes) -> None:
"""Forward data from the pipe"""
self._process.feed_data(self.decode(data), self._datatype)
def eof_received(self) -> None:
"""Forward EOF from the pipe"""
self.check_partial()
self._process.feed_eof(self._datatype)
def pause_reading(self) -> None:
"""Pause reading from the pipe"""
assert self._transport is not None
self._transport.pause_reading()
def resume_reading(self) -> None:
"""Resume reading from the pipe"""
assert self._transport is not None
self._transport.resume_reading()
def close(self) -> None:
"""Stop forwarding data from the pipe"""
assert self._transport is not None
self._transport.close()
class _PipeWriter(_UnicodeWriter[AnyStr], asyncio.BaseProtocol):
"""Forward data to a pipe"""
def __init__(self, process: 'SSHProcess[AnyStr]', datatype: DataType,
needs_close: bool, encoding: Optional[str], errors: str):
super().__init__(encoding, errors)
self._process: 'SSHProcess[AnyStr]' = process
self._datatype = datatype
self._needs_close = needs_close
self._transport: Optional[asyncio.WriteTransport] = None
def connection_made(self, transport: asyncio.BaseTransport) -> None:
"""Handle a newly opened pipe"""
self._transport = cast(asyncio.WriteTransport, transport)
def pause_writing(self) -> None:
"""Pause writing to the pipe"""
self._process.pause_feeding(self._datatype)
def resume_writing(self) -> None:
"""Resume writing to the pipe"""
self._process.resume_feeding(self._datatype)
def write(self, data: AnyStr) -> None:
"""Write data to the pipe"""
assert self._transport is not None
self._transport.write(self.encode(data))
def write_eof(self) -> None:
"""Write EOF to the pipe"""
assert self._transport is not None
self._transport.write_eof()
def close(self) -> None:
"""Stop forwarding data to the pipe"""
assert self._transport is not None
# There's currently no public API to tell connect_write_pipe()
# to not close the pipe on when the created transport is closed,
# and not closing it triggers an "unclosed transport" warning.
# This masks that warning when we want to keep the pipe open.
#
# pylint: disable=protected-access
if self._needs_close:
self._transport.close()
else:
self._transport._pipe = None # type: ignore
class _ProcessReader(_ReaderProtocol, Generic[AnyStr]):
"""Forward data from another SSH process"""
def __init__(self, process: 'SSHProcess[AnyStr]', datatype: DataType):
super().__init__()
self._process: 'SSHProcess[AnyStr]' = process
self._datatype = datatype
def pause_reading(self) -> None:
"""Pause reading from the other channel"""
self._process.pause_feeding(self._datatype)
def resume_reading(self) -> None:
"""Resume reading from the other channel"""
self._process.resume_feeding(self._datatype)
def close(self) -> None:
"""Stop forwarding data from the other channel"""
self._process.clear_writer(self._datatype)
class _ProcessWriter(_WriterProtocol[AnyStr]):
"""Forward data to another SSH process"""
def __init__(self, process: 'SSHProcess[AnyStr]', datatype: DataType):
super().__init__()
self._process: 'SSHProcess[AnyStr]' = process
self._datatype = datatype
def write(self, data: AnyStr) -> None:
"""Write data to the other channel"""
self._process.feed_data(data, self._datatype)
def write_exception(self, exc: Exception) -> None:
"""Write an exception to the other channel"""
cast(SSHClientProcess, self._process).feed_exception(exc)
def write_eof(self) -> None:
"""Write EOF to the other channel"""
self._process.feed_eof(self._datatype)
def close(self) -> None:
"""Stop forwarding data to the other channel"""
self._process.clear_reader(self._datatype)
class _StreamReader(_UnicodeReader[AnyStr]):
"""Forward data from an asyncio stream"""
def __init__(self, process: 'SSHProcess[AnyStr]',
reader: asyncio.StreamReader,
bufsize: int, datatype: DataType,
encoding: Optional[str], errors: str):
super().__init__(encoding, errors)
self._process: 'SSHProcess[AnyStr]' = process
self._conn = process.channel.get_connection()
self._reader = reader
self._bufsize = bufsize
self._datatype = datatype
self._paused = False
async def _feed(self) -> None:
"""Feed stream data"""
while not self._paused:
data = await self._reader.read(self._bufsize)
if data:
self._process.feed_data(self.decode(data), self._datatype)
else:
self.check_partial()
self._process.feed_eof(self._datatype)
break
def feed(self) -> None:
"""Start feeding stream data"""
self._conn.create_task(self._feed())
def pause_reading(self) -> None:
"""Pause reading from the stream"""
self._paused = True
def resume_reading(self) -> None:
"""Resume reading from the stream"""
self._paused = False
self.feed()
def close(self) -> None:
"""Ignore close -- the caller must clean up the associated transport"""
class _StreamWriter(_UnicodeWriter[AnyStr]):
"""Forward data to an asyncio stream"""
def __init__(self, writer: asyncio.StreamWriter,
encoding: Optional[str], errors: str):
super().__init__(encoding, errors)
self._writer = writer
def write(self, data: AnyStr) -> None:
"""Write data to the stream"""
self._writer.write(self.encode(data))
def write_eof(self) -> None:
"""Write EOF to the stream"""
self._writer.write_eof()
def close(self) -> None:
"""Ignore close -- the caller must clean up the associated transport"""
class _DevNullWriter(_WriterProtocol[AnyStr]):
"""Discard data"""
def write(self, data: AnyStr) -> None:
"""Discard data being written"""
def write_eof(self) -> None:
"""Ignore end of file"""
def close(self) -> None:
"""Ignore close"""
class _StdoutWriter(_WriterProtocol[AnyStr]):
"""Forward data to an SSH process' stdout instead of stderr"""
def __init__(self, process: 'SSHProcess[AnyStr]'):
super().__init__()
self._process: 'SSHProcess[AnyStr]' = process
def write(self, data: AnyStr) -> None:
"""Pretend data was received on stdout"""
self._process.data_received(data, None)
def write_eof(self) -> None:
"""Ignore end of file"""
def close(self) -> None:
"""Ignore close"""
[docs]
class ProcessError(Error):
"""SSH Process error
This exception is raised when an :class:`SSHClientProcess` exits
with a non-zero exit status and error checking is enabled. In
addition to the usual error code, reason, and language, it
contains the following fields:
============ ======================================= =================
Field Description Type
============ ======================================= =================
env The environment the client requested `str` or `None`
to be set for the process
command The command the client requested the `str` or `None`
process to execute (if any)
subsystem The subsystem the client requested the `str` or `None`
process to open (if any)
exit_status The exit status returned, or -1 if an `int` or `None`
exit signal is sent
exit_signal The exit signal sent (if any) in the `tuple` or `None`
form of a tuple containing the signal
name, a `bool` for whether a core dump
occurred, a message associated with the
signal, and the language the message
was in
returncode The exit status returned, or negative `int` or `None`
of the signal number when an exit
signal is sent
stdout The output sent by the process to `str` or `bytes`
stdout (if not redirected)
stderr The output sent by the process to `str` or `bytes`
stderr (if not redirected)
============ ======================================= =================
"""
def __init__(self, env: Optional[Mapping[str, str]],
command: Optional[str], subsystem: Optional[str],
exit_status: Optional[int],
exit_signal: Optional[Tuple[str, bool, str, str]],
returncode: Optional[int], stdout: BytesOrStr,
stderr: BytesOrStr, reason: str = '',
lang: str = DEFAULT_LANG):
self.env = env
self.command = command
self.subsystem = subsystem
self.exit_status = exit_status
self.exit_signal = exit_signal
self.returncode = returncode
self.stdout = stdout
self.stderr = stderr
if exit_signal:
signal, core_dumped, msg, lang = exit_signal
reason = 'Process exited with signal %s%s%s' % \
(signal, ': ' + msg if msg else '',
' (core dumped)' if core_dumped else '')
elif exit_status:
reason = 'Process exited with non-zero exit status %s' % \
exit_status
super().__init__(exit_status or 0, reason, lang)
# pylint: disable=redefined-builtin
[docs]
class TimeoutError(ProcessError, asyncio.TimeoutError):
"""SSH Process timeout error
This exception is raised when a timeout occurs when calling the
:meth:`wait <SSHClientProcess.wait>` method on :class:`SSHClientProcess`
or the :meth:`run <SSHClientConnection.run>` method on
:class:`SSHClientConnection`. It is a subclass of :class:`ProcessError`
and contains all of the fields documented there, including any output
received on stdout and stderr prior to when the timeout occurred. It
is also a subclass of :class:`asyncio.TimeoutError`, for code that
might be expecting that.
"""
# pylint: enable=redefined-builtin
[docs]
class SSHCompletedProcess(Record):
"""Results from running an SSH process
This object is returned by the :meth:`run <SSHClientConnection.run>`
method on :class:`SSHClientConnection` when the requested command
has finished running. It contains the following fields:
============ ======================================= =================
Field Description Type
============ ======================================= =================
env The environment the client requested `dict` or `None`
to be set for the process
command The command the client requested the `str` or `None`
process to execute (if any)
subsystem The subsystem the client requested the `str` or `None`
process to open (if any)
exit_status The exit status returned, or -1 if an `int`
exit signal is sent
exit_signal The exit signal sent (if any) in the `tuple` or `None`
form of a tuple containing the signal
name, a `bool` for whether a core dump
occurred, a message associated with the
signal, and the language the message
was in
returncode The exit status returned, or negative `int`
of the signal number when an exit
signal is sent
stdout The output sent by the process to `str` or `bytes`
stdout (if not redirected)
stderr The output sent by the process to `str` or `bytes`
stderr (if not redirected)
============ ======================================= =================
"""
env: Optional[Mapping[str, str]]
command: Optional[str]
subsystem: Optional[str]
exit_status: Optional[int]
exit_signal: Optional[Tuple[str, bool, str, str]]
returncode: Optional[int]
stdout: Optional[BytesOrStr]
stderr: Optional[BytesOrStr]
class SSHProcess(SSHStreamSession, Generic[AnyStr]):
"""SSH process handler"""
def __init__(self, *args) -> None:
super().__init__(*args)
self._cleanup_tasks: List[Awaitable[None]] = []
self._readers: Dict[Optional[int], _ReaderProtocol] = {}
self._send_eof: Dict[Optional[int], bool] = {}
self._writers: Dict[Optional[int], _WriterProtocol[AnyStr]] = {}
self._recv_eof: Dict[Optional[int], bool] = {}
self._paused_write_streams: Set[Optional[int]] = set()
async def __aenter__(self) -> 'SSHProcess[AnyStr]':
"""Allow SSHProcess to be used as an async context manager"""
return self
async def __aexit__(self, _exc_type: Optional[Type[BaseException]],
_exc_value: Optional[BaseException],
_traceback: Optional[TracebackType]) -> bool:
"""Wait for a full channel close when exiting the async context"""
self.close()
await self.wait_closed()
return False
@property
def channel(self) -> SSHChannel[AnyStr]:
"""The channel associated with the process"""
assert self._chan is not None
return self._chan
@property
def logger(self) -> SSHLogger:
"""The logger associated with the process"""
assert self._chan is not None
return self._chan.logger
@property
def command(self) -> Optional[str]:
"""The command the client requested to execute, if any
If the client did not request that a command be executed,
this property will be set to `None`.
"""
assert self._chan is not None
return self._chan.get_command()
@property
def subsystem(self) -> Optional[str]:
"""The subsystem the client requested to open, if any
If the client did not request that a subsystem be opened,
this property will be set to `None`.
"""
assert self._chan is not None
return self._chan.get_subsystem()
@property
def env(self) -> Mapping[str, str]:
"""A mapping containing the environment set by the client"""
assert self._chan is not None
return self._chan.get_environment()
def get_extra_info(self, name: str, default: Any = None) -> Any:
"""Return additional information about this process
This method returns extra information about the channel
associated with this process. See :meth:`get_extra_info()
<SSHClientChannel.get_extra_info>` on :class:`SSHClientChannel`
for additional information.
"""
assert self._chan is not None
return self._chan.get_extra_info(name, default)
async def _create_reader(self, source: ProcessSource, bufsize: int,
send_eof: bool, recv_eof: bool,
datatype: DataType = None) -> None:
"""Create a reader to forward data to the SSH channel"""
def pipe_factory() -> _PipeReader:
"""Return a pipe read handler"""
return _PipeReader(self, datatype, self._encoding, self._errors)
if source == PIPE:
reader: Optional[_ReaderProtocol] = None
elif source == DEVNULL:
assert self._chan is not None
self._chan.write_eof()
reader = None
elif isinstance(source, SSHReader):
reader_stream, reader_datatype = source.get_redirect_info()
reader_process = cast('SSHProcess[AnyStr]', reader_stream)
writer = _ProcessWriter[AnyStr](self, datatype)
reader_process.set_writer(writer, recv_eof, reader_datatype)
reader = _ProcessReader(reader_process, reader_datatype)
elif isinstance(source, asyncio.StreamReader):
reader = _StreamReader(self, source, bufsize, datatype,
self._encoding, self._errors)
else:
file: _File
if isinstance(source, str):
file = open_file(source, 'rb', buffering=bufsize)
elif isinstance(source, PurePath):
file = open_file(str(source), 'rb', buffering=bufsize)
elif isinstance(source, int):
file = os.fdopen(source, 'rb', buffering=bufsize)
elif isinstance(source, socket.socket):
file = os.fdopen(source.detach(), 'rb', buffering=bufsize)
else:
file = source
if hasattr(file, 'read') and \
(asyncio.iscoroutinefunction(file.read) or
inspect.isgeneratorfunction(file.read)):
reader = _AsyncFileReader(self, cast(_AsyncFileProtocol, file),
bufsize, datatype, self._encoding,
self._errors)
elif _is_regular_file(cast(IO[bytes], file)):
reader = _FileReader(self, cast(IO[bytes], file), bufsize,
datatype, self._encoding, self._errors)
else:
if hasattr(source, 'buffer'):
# If file was opened in text mode, remove that wrapper
file = cast(TextIO, source).buffer
assert self._loop is not None
_, protocol = \
await self._loop.connect_read_pipe(pipe_factory, file)
reader = cast(_PipeReader, protocol)
self.set_reader(reader, send_eof, datatype)
if isinstance(reader, (_FileReader, _AsyncFileReader, _StreamReader)):
reader.feed()
elif isinstance(reader, _ProcessReader):
reader_process.feed_recv_buf(reader_datatype, writer)
async def _create_writer(self, target: ProcessTarget, bufsize: int,
send_eof: bool, recv_eof: bool,
datatype: DataType = None) -> None:
"""Create a writer to forward data from the SSH channel"""
def pipe_factory() -> _PipeWriter:
"""Return a pipe write handler"""
return _PipeWriter(self, datatype, recv_eof,
self._encoding, self._errors)
if target == PIPE:
writer: Optional[_WriterProtocol[AnyStr]] = None
elif target == DEVNULL:
writer = _DevNullWriter()
elif target == STDOUT:
writer = _StdoutWriter(self)
elif isinstance(target, SSHWriter):
writer_stream, writer_datatype = target.get_redirect_info()
writer_process = cast('SSHProcess[AnyStr]', writer_stream)
reader = _ProcessReader(self, datatype)
writer_process.set_reader(reader, send_eof, writer_datatype)
writer = _ProcessWriter[AnyStr](writer_process, writer_datatype)
elif isinstance(target, asyncio.StreamWriter):
writer = _StreamWriter(target, self._encoding, self._errors)
else:
file: _File
needs_close = True
if isinstance(target, str):
file = open_file(target, 'wb', buffering=bufsize)
elif isinstance(target, PurePath):
file = open_file(str(target), 'wb', buffering=bufsize)
elif isinstance(target, int):
file = os.fdopen(target, 'wb',
buffering=bufsize, closefd=recv_eof)
elif isinstance(target, socket.socket):
fd = target.detach() if recv_eof else target.fileno()
file = os.fdopen(fd, 'wb', buffering=bufsize, closefd=recv_eof)
else:
file = target
needs_close = recv_eof
if hasattr(file, 'write') and \
(asyncio.iscoroutinefunction(file.write) or
inspect.isgeneratorfunction(file.write)):
writer = _AsyncFileWriter(
self, cast(_AsyncFileProtocol, file), needs_close,
self._encoding, self._errors)
elif _is_regular_file(cast(IO[bytes], file)):
writer = _FileWriter(cast(IO[bytes], file), needs_close,
self._encoding, self._errors)
else:
if hasattr(target, 'buffer'):
# If file was opened in text mode, remove that wrapper
file = cast(TextIO, target).buffer
assert self._loop is not None
_, protocol = \
await self._loop.connect_write_pipe(pipe_factory, file)
writer = cast(_PipeWriter, protocol)
self.set_writer(writer, recv_eof, datatype)
if writer:
self.feed_recv_buf(datatype, writer)
def _should_block_drain(self, datatype: DataType) -> bool:
"""Return whether output is still being written to the channel"""
return (datatype in self._readers or
super()._should_block_drain(datatype))
def _should_pause_reading(self) -> bool:
"""Return whether to pause reading from the channel"""
return bool(self._paused_write_streams) or \
super()._should_pause_reading()
def add_cleanup_task(self, task: Awaitable[None]) -> None:
"""Add a task to run when the process exits"""
self._cleanup_tasks.append(task)
def connection_lost(self, exc: Optional[Exception]) -> None:
"""Handle a close of the SSH channel"""
super().connection_lost(exc) # type: ignore
for reader in list(self._readers.values()):
reader.close()
for writer in list(self._writers.values()):
writer.close()
self._readers = {}
self._writers = {}
def data_received(self, data: AnyStr, datatype: DataType) -> None:
"""Handle incoming data from the SSH channel"""
writer = self._writers.get(datatype)
if writer:
writer.write(data)
else:
super().data_received(data, datatype)
def eof_received(self) -> bool:
"""Handle an incoming end of file from the SSH channel"""
for datatype, writer in list(self._writers.items()):
if self._recv_eof[datatype]:
writer.write_eof()
return super().eof_received()
def pause_writing(self) -> None:
"""Pause forwarding data to the channel"""
super().pause_writing()
for reader in list(self._readers.values()):
reader.pause_reading()
def resume_writing(self) -> None:
"""Resume forwarding data to the channel"""
super().resume_writing()
for reader in list(self._readers.values()):
reader.resume_reading()
def feed_data(self, data: AnyStr, datatype: DataType) -> None:
"""Feed data to the channel"""
assert self._chan is not None
self._chan.write(data, datatype)
def feed_eof(self, datatype: DataType) -> None:
"""Feed EOF to the channel"""
if self._send_eof[datatype]:
assert self._chan is not None
self._chan.write_eof()
self._readers[datatype].close()
self.clear_reader(datatype)
def feed_recv_buf(self, datatype: DataType,
writer: _WriterProtocol[AnyStr]) -> None:
"""Feed current receive buffer to a newly set writer"""
for buf in self._recv_buf[datatype]:
if isinstance(buf, Exception):
writer.write_exception(buf)
else:
writer.write(buf)
self._recv_buf_len -= len(buf)
self._recv_buf[datatype].clear()
if self._eof_received:
writer.write_eof()
self._maybe_resume_reading()
def pause_feeding(self, datatype: DataType) -> None:
"""Pause feeding data from the channel"""
self._paused_write_streams.add(datatype)
self._maybe_pause_reading()
def resume_feeding(self, datatype: DataType) -> None:
"""Resume feeding data from the channel"""
self._paused_write_streams.remove(datatype)
self._maybe_resume_reading()
def set_reader(self, reader: Optional[_ReaderProtocol],
send_eof: bool, datatype: DataType) -> None:
"""Set a reader used to forward data to the channel"""
old_reader = self._readers.get(datatype)
if old_reader:
old_reader.close()
if reader:
self._readers[datatype] = reader
self._send_eof[datatype] = send_eof
if self._write_paused:
reader.pause_reading()
elif old_reader:
self.clear_reader(datatype)
def clear_reader(self, datatype: DataType) -> None:
"""Clear a reader forwarding data to the channel"""
del self._readers[datatype]
del self._send_eof[datatype]
self._unblock_drain(datatype)
def set_writer(self, writer: Optional[_WriterProtocol[AnyStr]],
recv_eof: bool, datatype: DataType) -> None:
"""Set a writer used to forward data from the channel"""
old_writer = self._writers.get(datatype)
if old_writer:
old_writer.close()
self.clear_writer(datatype)
if writer:
self._writers[datatype] = writer
self._recv_eof[datatype] = recv_eof
def clear_writer(self, datatype: DataType) -> None:
"""Clear a writer forwarding data from the channel"""
if datatype in self._paused_write_streams:
self.resume_feeding(datatype)
del self._writers[datatype]
def close(self) -> None:
"""Shut down the process"""
assert self._chan is not None
self._chan.close()
def is_closing(self) -> bool:
"""Return if the channel is closing or is closed"""
assert self._chan is not None
return self._chan.is_closing()
async def wait_closed(self) -> None:
"""Wait for the process to finish shutting down"""
assert self._chan is not None
await self._chan.wait_closed()
for task in self._cleanup_tasks:
await task
[docs]
class SSHClientProcess(SSHProcess[AnyStr], SSHClientStreamSession[AnyStr]):
"""SSH client process handler"""
_chan: SSHClientChannel[AnyStr]
channel: SSHClientChannel[AnyStr]
def __init__(self) -> None:
super().__init__()
self._stdin: Optional[SSHWriter[AnyStr]] = None
self._stdout: Optional[SSHReader[AnyStr]] = None
self._stderr: Optional[SSHReader[AnyStr]] = None
def _collect_output(self, datatype: DataType = None) -> AnyStr:
"""Return output from the process"""
recv_buf = self._recv_buf[datatype]
if recv_buf and isinstance(recv_buf[-1], Exception):
recv_buf, self._recv_buf[datatype] = recv_buf[:-1], recv_buf[-1:]
else:
self._recv_buf[datatype] = []
buf = cast(AnyStr, '' if self._encoding else b'')
return buf.join(cast(Iterable[AnyStr], recv_buf))
def session_started(self) -> None:
"""Start a process for this newly opened client channel"""
self._stdin = SSHWriter[AnyStr](self, self._chan)
self._stdout = SSHReader[AnyStr](self, self._chan)
self._stderr = SSHReader[AnyStr](self, self._chan, EXTENDED_DATA_STDERR)
@property
def exit_status(self) -> Optional[int]:
"""The exit status of the process"""
return self._chan.get_exit_status()
@property
def exit_signal(self) -> Optional[Tuple[str, bool, str, str]]:
"""Exit signal information for the process"""
return self._chan.get_exit_signal()
@property
def returncode(self) -> Optional[int]:
"""The exit status or negative exit signal number for the process"""
return self._chan.get_returncode()
@property
def stdin(self) -> SSHWriter[AnyStr]:
"""The :class:`SSHWriter` to use to write to stdin of the process"""
assert self._stdin is not None
return self._stdin
@property
def stdout(self) -> SSHReader[AnyStr]:
"""The :class:`SSHReader` to use to read from stdout of the process"""
assert self._stdout is not None
return self._stdout
@property
def stderr(self) -> SSHReader[AnyStr]:
"""The :class:`SSHReader` to use to read from stderr of the process"""
assert self._stderr is not None
return self._stderr
def feed_exception(self, exc: Exception) -> None:
"""Feed exception to the channel"""
if isinstance(exc, TerminalSizeChanged):
self._chan.change_terminal_size(exc.width, exc.height,
exc.pixwidth, exc.pixheight)
elif isinstance(exc, BreakReceived):
self._chan.send_break(exc.msec)
elif isinstance(exc, SignalReceived): # pragma: no branch
self._chan.send_signal(exc.signal)
[docs]
async def redirect(self, stdin: Optional[ProcessSource] = None,
stdout: Optional[ProcessTarget] = None,
stderr: Optional[ProcessTarget] = None,
bufsize: int =io.DEFAULT_BUFFER_SIZE,
send_eof: bool = True, recv_eof: bool = True) -> None:
"""Perform I/O redirection for the process
This method redirects data going to or from any or all of
standard input, standard output, and standard error for
the process.
The `stdin` argument can be any of the following:
* An :class:`SSHReader` object
* An :class:`asyncio.StreamReader` object
* A file object open for read
* An `int` file descriptor open for read
* A connected socket object
* A string or :class:`PurePath <pathlib.PurePath>` containing
the name of a file or device to open
* `DEVNULL` to provide no input to standard input
* `PIPE` to interactively write standard input
The `stdout` and `stderr` arguments can be any of the following:
* An :class:`SSHWriter` object
* An :class:`asyncio.StreamWriter` object
* A file object open for write
* An `int` file descriptor open for write
* A connected socket object
* A string or :class:`PurePath <pathlib.PurePath>` containing
the name of a file or device to open
* `DEVNULL` to discard standard error output
* `PIPE` to interactively read standard error output
The `stderr` argument also accepts the value `STDOUT` to
request that standard error output be delivered to stdout.
File objects passed in can be associated with plain files, pipes,
sockets, or ttys.
The default value of `None` means to not change redirection
for that stream.
.. note:: When passing in asyncio streams, it is the responsibility
of the caller to close the associated transport when it
is no longer needed.
:param stdin:
Source of data to feed to standard input
:param stdout:
Target to feed data from standard output to
:param stderr:
Target to feed data from standard error to
:param bufsize:
Buffer size to use when forwarding data from a file
:param send_eof:
Whether or not to send EOF to the channel when EOF is
received from stdin, defaulting to `True`. If set to `False`,
the channel will remain open after EOF is received on stdin,
and multiple sources can be redirected to the channel.
:param recv_eof:
Whether or not to send EOF to stdout and stderr when EOF is
received from the channel, defaulting to `True`. If set to
`False`, the redirect targets of stdout and stderr will remain
open after EOF is received on the channel and can be used for
multiple redirects.
:type bufsize: `int`
:type send_eof: `bool`
:type recv_eof: `bool`
"""
if stdin:
await self._create_reader(stdin, bufsize, send_eof, recv_eof)
if stdout:
await self._create_writer(stdout, bufsize, send_eof, recv_eof)
if stderr:
await self._create_writer(stderr, bufsize, send_eof, recv_eof,
EXTENDED_DATA_STDERR)
async def redirect_stdin(self, source: ProcessSource,
bufsize: int = io.DEFAULT_BUFFER_SIZE,
send_eof: bool = True) -> None:
"""Redirect standard input of the process"""
await self.redirect(source, None, None, bufsize, send_eof, True)
async def redirect_stdout(self, target: ProcessTarget,
bufsize: int = io.DEFAULT_BUFFER_SIZE,
recv_eof: bool = True) -> None:
"""Redirect standard output of the process"""
await self.redirect(None, target, None, bufsize, True, recv_eof)
async def redirect_stderr(self, target: ProcessTarget,
bufsize: int = io.DEFAULT_BUFFER_SIZE,
recv_eof: bool = True) -> None:
"""Redirect standard error of the process"""
await self.redirect(None, None, target, bufsize, True, recv_eof)
[docs]
def collect_output(self) -> Tuple[AnyStr, AnyStr]:
"""Collect output from the process without blocking
This method returns a tuple of the output that the process
has written to stdout and stderr which has not yet been read.
It is intended to be called instead of read() by callers
that want to collect received data without blocking.
:returns: A tuple of output to stdout and stderr
"""
return (self._collect_output(),
self._collect_output(EXTENDED_DATA_STDERR))
# pylint: disable=redefined-builtin
[docs]
async def communicate(self, input: Optional[AnyStr] = None) -> \
Tuple[AnyStr, AnyStr]:
"""Send input to and/or collect output from the process
This method is a coroutine which optionally provides input
to the process and then waits for the process to exit,
returning a tuple of the data written to stdout and stderr.
:param input:
Input data to feed to standard input of the process. Data
should be a `str` if encoding is set, or `bytes` if not.
:type input: `str` or `bytes`
:returns: A tuple of output to stdout and stderr
"""
self._limit = 0
self._maybe_resume_reading()
if input:
self._chan.write(input)
self._chan.write_eof()
await self.wait_closed()
return self.collect_output()
# pylint: enable=redefined-builtin
[docs]
def change_terminal_size(self, width: int, height: int,
pixwidth: int = 0, pixheight: int = 0) -> None:
"""Change the terminal window size for this process
This method changes the width and height of the terminal
associated with this process.
:param width:
The width of the terminal in characters
:param height:
The height of the terminal in characters
:param pixwidth: (optional)
The width of the terminal in pixels
:param pixheight: (optional)
The height of the terminal in pixels
:type width: `int`
:type height: `int`
:type pixwidth: `int`
:type pixheight: `int`
:raises: :exc:`OSError` if the SSH channel is not open
"""
self._chan.change_terminal_size(width, height, pixwidth, pixheight)
[docs]
def send_break(self, msec: int) -> None:
"""Send a break to the process
:param msec:
The duration of the break in milliseconds
:type msec: `int`
:raises: :exc:`OSError` if the SSH channel is not open
"""
self._chan.send_break(msec)
[docs]
def send_signal(self, signal: str) -> None:
"""Send a signal to the process
:param signal:
The signal to deliver
:type signal: `str`
:raises: :exc:`OSError` if the SSH channel is not open
"""
self._chan.send_signal(signal)
[docs]
def terminate(self) -> None:
"""Terminate the process
:raises: :exc:`OSError` if the SSH channel is not open
"""
self._chan.terminate()
[docs]
def kill(self) -> None:
"""Forcibly kill the process
:raises: :exc:`OSError` if the SSH channel is not open
"""
self._chan.kill()
[docs]
async def wait(self, check: bool = False,
timeout: Optional[float] = None) -> SSHCompletedProcess:
"""Wait for process to exit
This method is a coroutine which waits for the process to
exit. It returns an :class:`SSHCompletedProcess` object with
the exit status or signal information and the output sent
to stdout and stderr if those are redirected to pipes.
If the check argument is set to `True`, a non-zero exit
status from the process with trigger the :exc:`ProcessError`
exception to be raised.
If a timeout is specified and it expires before the process
exits, the :exc:`TimeoutError` exception will be raised. By
default, no timeout is set and this call will wait indefinitely.
:param check:
Whether or not to raise an error on non-zero exit status
:param timeout:
Amount of time in seconds to wait for process to exit, or
`None` to wait indefinitely
:type check: `bool`
:type timeout: `int`, `float`, or `None`
:returns: :class:`SSHCompletedProcess`
:raises: | :exc:`ProcessError` if check is set to `True`
and the process returns a non-zero exit status
| :exc:`TimeoutError` if the timeout expires
before the process exits
"""
try:
stdout_data, stderr_data = \
await asyncio.wait_for(self.communicate(), timeout)
except asyncio.TimeoutError:
stdout_data, stderr_data = self.collect_output()
raise TimeoutError(self.env, self.command, self.subsystem,
self.exit_status, self.exit_signal,
self.returncode, stdout_data,
stderr_data) from None
if check and self.exit_status:
raise ProcessError(self.env, self.command, self.subsystem,
self.exit_status, self.exit_signal,
self.returncode, stdout_data, stderr_data)
else:
return SSHCompletedProcess(self.env, self.command, self.subsystem,
self.exit_status, self.exit_signal,
self.returncode, stdout_data,
stderr_data)
[docs]
class SSHServerProcess(SSHProcess[AnyStr], SSHServerStreamSession[AnyStr]):
"""SSH server process handler"""
_chan: SSHServerChannel[AnyStr]
channel: SSHServerChannel[AnyStr]
def __init__(self, process_factory: SSHServerProcessFactory,
sftp_factory: Optional[SFTPServerFactory],
sftp_version: int, allow_scp: bool):
super().__init__(self._start_process, sftp_factory,
sftp_version, allow_scp)
self._process_factory = process_factory
self._stdin: Optional[SSHReader[AnyStr]] = None
self._stdout: Optional[SSHWriter[AnyStr]] = None
self._stderr: Optional[SSHWriter[AnyStr]] = None
def _start_process(self, stdin: SSHReader[AnyStr],
stdout: SSHWriter[AnyStr],
stderr: SSHWriter[AnyStr]) -> MaybeAwait[None]:
"""Start a new server process"""
self._stdin = stdin
self._stdout = stdout
self._stderr = stderr
return self._process_factory(self)
@property
def term_type(self) -> Optional[str]:
"""The terminal type set by the client
If the client didn't request a pseudo-terminal, this
property will be set to `None`.
"""
return self._chan.get_terminal_type()
@property
def term_size(self) -> TermSize:
"""The terminal size set by the client
This property contains a tuple of four `int` values
representing the width and height of the terminal in
characters followed by the width and height of the
terminal in pixels. If the client hasn't set terminal
size information, the values will be set to zero.
"""
return self._chan.get_terminal_size()
@property
def term_modes(self) -> TermModes:
"""A mapping containing the TTY modes set by the client
If the client didn't request a pseudo-terminal, this
property will be set to an empty mapping.
"""
return self._chan.get_terminal_modes()
@property
def stdin(self) -> SSHReader[AnyStr]:
"""The :class:`SSHReader` to use to read from stdin of the process"""
assert self._stdin is not None
return self._stdin
@property
def stdout(self) -> SSHWriter[AnyStr]:
"""The :class:`SSHWriter` to use to write to stdout of the process"""
assert self._stdout is not None
return self._stdout
@property
def stderr(self) -> SSHWriter[AnyStr]:
"""The :class:`SSHWriter` to use to write to stderr of the process"""
assert self._stderr is not None
return self._stderr
def exception_received(self, exc: Exception) -> None:
"""Handle an incoming exception on the channel"""
writer = self._writers.get(None)
if writer:
writer.write_exception(exc)
else:
super().exception_received(exc)
[docs]
async def redirect(self, stdin: Optional[ProcessTarget] = None,
stdout: Optional[ProcessSource] = None,
stderr: Optional[ProcessSource] = None,
bufsize: int = io.DEFAULT_BUFFER_SIZE,
send_eof: bool = True, recv_eof: bool = True) -> None:
"""Perform I/O redirection for the process
This method redirects data going to or from any or all of
standard input, standard output, and standard error for
the process.
The `stdin` argument can be any of the following:
* An :class:`SSHWriter` object
* An :class:`asyncio.StreamWriter` object
* A file object open for write
* An `int` file descriptor open for write
* A connected socket object
* A string or :class:`PurePath <pathlib.PurePath>` containing
the name of a file or device to open
* `DEVNULL` to discard standard error output
* `PIPE` to interactively read standard error output
The `stdout` and `stderr` arguments can be any of the following:
* An :class:`SSHReader` object
* An :class:`asyncio.StreamReader` object
* A file object open for read
* An `int` file descriptor open for read
* A connected socket object
* A string or :class:`PurePath <pathlib.PurePath>` containing
the name of a file or device to open
* `DEVNULL` to provide no input to standard input
* `PIPE` to interactively write standard input
File objects passed in can be associated with plain files, pipes,
sockets, or ttys.
The default value of `None` means to not change redirection
for that stream.
.. note:: When passing in asyncio streams, it is the responsibility
of the caller to close the associated transport when it
is no longer needed.
:param stdin:
Target to feed data from standard input to
:param stdout:
Source of data to feed to standard output
:param stderr:
Source of data to feed to standard error
:param bufsize:
Buffer size to use when forwarding data from a file
:param send_eof:
Whether or not to send EOF to the channel when EOF is
received from stdout or stderr, defaulting to `True`. If
set to `False`, the channel will remain open after EOF is
received on stdout or stderr, and multiple sources can be
redirected to the channel.
:param recv_eof:
Whether or not to send EOF to stdin when EOF is received
on the channel, defaulting to `True`. If set to `False`,
the redirect target of stdin will remain open after EOF
is received on the channel and can be used for multiple
redirects.
:type bufsize: `int`
:type send_eof: `bool`
:type recv_eof: `bool`
"""
if stdin:
await self._create_writer(stdin, bufsize, send_eof, recv_eof)
if stdout:
await self._create_reader(stdout, bufsize, send_eof, recv_eof)
if stderr:
await self._create_reader(stderr, bufsize, send_eof, recv_eof,
EXTENDED_DATA_STDERR)
async def redirect_stdin(self, target: ProcessTarget,
bufsize: int = io.DEFAULT_BUFFER_SIZE,
recv_eof: bool = True) -> None:
"""Redirect standard input of the process"""
await self.redirect(target, None, None, bufsize, True, recv_eof)
async def redirect_stdout(self, source: ProcessSource,
bufsize: int = io.DEFAULT_BUFFER_SIZE,
send_eof: bool = True) -> None:
"""Redirect standard output of the process"""
await self.redirect(None, source, None, bufsize, send_eof, True)
async def redirect_stderr(self, source: ProcessSource,
bufsize: int = io.DEFAULT_BUFFER_SIZE,
send_eof: bool = True) -> None:
"""Redirect standard error of the process"""
await self.redirect(None, None, source, bufsize, send_eof, True)
def get_terminal_type(self) -> Optional[str]:
"""Return the terminal type set by the client for the process
This method returns the terminal type set by the client
when the process was started. If the client didn't request
a pseudo-terminal, this method will return `None`.
:returns: A `str` containing the terminal type or `None` if
no pseudo-terminal was requested
"""
return self.term_type
def get_terminal_size(self) -> Tuple[int, int, int, int]:
"""Return the terminal size set by the client for the process
This method returns the latest terminal size information set
by the client. If the client didn't set any terminal size
information, all values returned will be zero.
:returns: A tuple of four `int` values containing the width and
height of the terminal in characters and the width
and height of the terminal in pixels
"""
return self.term_size
def get_terminal_mode(self, mode: int) -> Optional[int]:
"""Return the requested TTY mode for this session
This method looks up the value of a POSIX terminal mode
set by the client when the process was started. If the client
didn't request a pseudo-terminal or didn't set the requested
TTY mode opcode, this method will return `None`.
:param mode:
POSIX terminal mode taken from :ref:`POSIX terminal modes
<PTYModes>` to look up
:type mode: `int`
:returns: An `int` containing the value of the requested
POSIX terminal mode or `None` if the requested
mode was not set
"""
return self.term_modes.get(mode)
[docs]
def exit(self, status: int) -> None:
"""Send exit status and close the channel
This method can be called to report an exit status for the
process back to the client and close the channel.
:param status:
The exit status to report to the client
:type status: `int`
"""
self._chan.exit(status)
[docs]
def exit_with_signal(self, signal: str, core_dumped: bool = False,
msg: str = '', lang: str = DEFAULT_LANG) -> None:
"""Send exit signal and close the channel
This method can be called to report that the process
terminated abnormslly with a signal. A more detailed
error message may also provided, along with an indication
of whether or not the process dumped core. After
reporting the signal, the channel is closed.
:param signal:
The signal which caused the process to exit
:param core_dumped: (optional)
Whether or not the process dumped core
:param msg: (optional)
Details about what error occurred
:param lang: (optional)
The language the error message is in
:type signal: `str`
:type core_dumped: `bool`
:type msg: `str`
:type lang: `str`
"""
return self._chan.exit_with_signal(signal, core_dumped, msg, lang)