flickerstrip-py/flickerstrip_py/ssdp.py

67 lines
2.2 KiB
Python

# Copyright 2014 Dan Krause, Python 3 hack 2016 Adam Baxter
#
# 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
#
# http://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.
import socket
import http.client
import io
class SSDPResponse(object):
class _FakeSocket(io.BytesIO):
def makefile(self, *args, **kw):
return self
def __init__(self, response):
r = http.client.HTTPResponse(self._FakeSocket(response))
r.begin()
self.location = r.getheader("location")
self.usn = r.getheader("usn")
self.st = r.getheader("st")
self.cache = r.getheader("cache-control").split("=")[1]
def __repr__(self):
return "<SSDPResponse({location}, {st}, {usn})>"\
.format(**self.__dict__)
def discover(service, timeout=5, retries=1, mx=3):
group = ("239.255.255.250", 1900)
message = "\r\n".join([
'M-SEARCH * HTTP/1.1',
'HOST: {0}:{1}',
'MAN: "ssdp:discover"',
'ST: {st}', 'MX: {mx}', '', ''])
socket.setdefaulttimeout(timeout)
responses = {}
for _ in range(retries):
sock = socket.socket(
socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 2)
message_bytes = message.format(
*group, st=service, mx=mx).encode('utf-8')
sock.sendto(message_bytes, group)
while True:
try:
response = SSDPResponse(sock.recv(1024))
responses[response.location] = response
except socket.timeout:
break
return list(responses.values())
# Example:
# import ssdp
# ssdp.discover("roku:ecp")