| # Copyright 2021-2022 Google LLC |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # https://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| # ----------------------------------------------------------------------------- |
| # Imports |
| # ----------------------------------------------------------------------------- |
| import asyncio |
| import logging |
| |
| from .common import Transport, ParserSource |
| |
| # ----------------------------------------------------------------------------- |
| # Logging |
| # ----------------------------------------------------------------------------- |
| logger = logging.getLogger(__name__) |
| |
| |
| # ----------------------------------------------------------------------------- |
| async def open_udp_transport(spec): |
| ''' |
| Open a UDP transport. |
| The parameter string has this syntax: |
| <local-host>:<local-port>,<remote-host>:<remote-port> |
| |
| Example: 0.0.0.0:9000,127.0.0.1:9001 |
| ''' |
| |
| class UdpPacketSource(asyncio.DatagramProtocol, ParserSource): |
| def datagram_received(self, data, addr): |
| self.parser.feed_data(data) |
| |
| class UdpPacketSink: |
| def __init__(self, transport): |
| self.transport = transport |
| |
| def on_packet(self, packet): |
| self.transport.sendto(packet) |
| |
| def close(self): |
| self.transport.close() |
| |
| local, remote = spec.split(',') |
| local_host, local_port = local.split(':') |
| remote_host, remote_port = remote.split(':') |
| ( |
| udp_transport, |
| packet_source, |
| ) = await asyncio.get_running_loop().create_datagram_endpoint( |
| UdpPacketSource, |
| local_addr=(local_host, int(local_port)), |
| remote_addr=(remote_host, int(remote_port)), |
| ) |
| packet_sink = UdpPacketSink(udp_transport) |
| |
| return Transport(packet_source, packet_sink) |