import socket
from http.client import HTTPResponse
from io import BytesIO, StringIO
import click
PARADROP_URN = "urn:schemas-upnp-org:service:Paradrop:1"
class SsdpResponse(HTTPResponse):
def __init__(self, response_text, source):
self.fp = StringIO(response_text)
self.debuglevel = 0
self.strict = 0
self.msg = None
self._method = None
self.source = source
self.begin()
def perform_ssdp_discovery(service, timeout=5, retries=5, mx=3):
# Standard multicast IP address and port for SSDP.
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}"
]).format(*group, st=service, mx=mx)
socket.setdefaulttimeout(timeout)
sources = set()
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)
sock.sendto(message.encode('utf-8'), group)
while True:
try:
data, addr = sock.recvfrom(1024)
response = SsdpResponse(data, addr)
if addr[0] not in sources:
# We only want to return each node once.
sources.add(addr[0])
yield response
except socket.timeout:
break
@click.command('discover')
@click.pass_context
def root(ctx):
"""
Discover Paradrop nodes on the network.
"""
click.echo("Discovering...")
for response in perform_ssdp_discovery(PARADROP_URN):
click.echo("Response from {:16s}".format(response.source[0]))
server = response.getheader("SERVER")
if server is not None:
click.echo(" {}".format(server))
