107 lines
3.9 KiB
Python
107 lines
3.9 KiB
Python
# -*- coding: utf-8 -*-
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"""
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proxy.py
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~~~~~~~~
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⚡⚡⚡ Fast, Lightweight, Pluggable, TLS interception capable proxy server focused on
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Network monitoring, controls & Application development, testing, debugging.
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:copyright: (c) 2013-present by Abhinav Singh and contributors.
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:license: BSD, see LICENSE for more details.
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"""
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from abc import abstractmethod
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import socket
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import selectors
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from typing import Dict, Any, Optional
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from proxy.core.acceptor import Work
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from proxy.common.types import Readables, Writables
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class BaseTcpServerHandler(Work):
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"""BaseTcpServerHandler implements Work interface.
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An instance of BaseTcpServerHandler is created for each client
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connection. BaseServerHandler lifecycle is controlled by
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Threadless core using asyncio.
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BaseServerHandler ensures that pending buffers are flushed
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before client connection is closed.
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Implementations must provide:
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a) handle_data(data: memoryview)
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c) (optionally) intialize, is_inactive and shutdown methods
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"""
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def __init__(self, *args: Any, **kwargs: Any) -> None:
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super().__init__(*args, **kwargs)
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self.must_flush_before_shutdown = False
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print('Connection accepted from {0}'.format(self.client.addr))
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@abstractmethod
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def handle_data(self, data: memoryview) -> Optional[bool]:
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"""Optionally return True to close client connection."""
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pass # pragma: no cover
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def get_events(self) -> Dict[socket.socket, int]:
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events = {}
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# We always want to read from client
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# Register for EVENT_READ events
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if self.must_flush_before_shutdown is False:
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events[self.client.connection] = selectors.EVENT_READ
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# If there is pending buffer for client
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# also register for EVENT_WRITE events
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if self.client.has_buffer():
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if self.client.connection in events:
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events[self.client.connection] |= selectors.EVENT_WRITE
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else:
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events[self.client.connection] = selectors.EVENT_WRITE
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return events
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def handle_events(
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self,
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readables: Readables,
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writables: Writables) -> bool:
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"""Return True to shutdown work."""
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do_shutdown = False
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if self.client.connection in readables:
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try:
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data = self.client.recv()
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if data is None:
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# Client closed connection, signal shutdown
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print(
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'Connection closed by client {0}'.format(
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self.client.addr))
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do_shutdown = True
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else:
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r = self.handle_data(data)
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if isinstance(r, bool) and r is True:
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print(
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'Implementation signaled shutdown for client {0}'.format(
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self.client.addr))
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if self.client.has_buffer():
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print(
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'Client {0} has pending buffer, will be flushed before shutting down'.format(
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self.client.addr))
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self.must_flush_before_shutdown = True
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else:
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do_shutdown = True
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except ConnectionResetError:
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print(
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'Connection reset by client {0}'.format(
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self.client.addr))
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do_shutdown = True
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if self.client.connection in writables:
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print('Flushing buffer to client {0}'.format(self.client.addr))
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self.client.flush()
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if self.must_flush_before_shutdown is True:
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do_shutdown = True
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self.must_flush_before_shutdown = False
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if do_shutdown:
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print(
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'Shutting down client {0} connection'.format(
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self.client.addr))
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return do_shutdown
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