#ssdp-fake
Spoof SSDP announcements for devices off-lan
This is a quick hack to send out SSDP announcements for devices which are not on the LAN. Currently it is very hacky, and it only works for Media Servers.
This allows access to media servers which are not on the same LAN, as long as they are accessible by both UDP and TCP.
It works by sending a unicast request to the server (you have to know the IP address of the server), picking the URL from the response, and then sending out local multicast announcements for the server. It is very simple: it sends all the multicast announcements periodically, and it sends all the responses whenever it sees a search.
Note: all this handles is the discovery. The client then uses the URL to contact the server directly.
There are two files: a Python version (ssdp-fake.py) and a Perl version
(ssdp-fake). At the moment, they are at roughly the same functional level but
the perl version is the most recent and is in daily use. But check
the dates to see if that is still true when you read this!
ssdp-fake --listen-only [--interface <ifname-or-ip-address>]... [--ignore <ip-address>]...
ssdp-fake [--interface <ifname-or-ip-address>]... [--timer N] servername-or-address
ssdp-fake [--interface <ifname-or-ip-address>]... [--timer N] server-url server-UUID
Specifying the server name or address is preferred. In this case, the URL and UUID will be fetched from the server, and the announcements will only be made if the server is responding.
The last command line maually configures the server information to send. In this case, the server is not contacted at all and the announcements are made without any checks on whether the server is actually available.
Not specifying an interface should send announcements on all interfaces (although it is not clear this works on all systems). Or one or more interfaces can be specified to confine the announcements to those interfaces.
ssdp-fake.py --help
ssdp-fake.py --listen-only
ssdp-fake.py --all [--interval=N] server.ip.address
--all is recommended. Leaving it out is supposed to confine the announcements to the loopback
interface so only clients on the same host will see the server, but it doesn't work properly.
It would be nice to be able to list multiple servers and have them all announced. At the moment, the code only handles a single server but it is possible to run multiple copies on the same system to announce for multiple servers.
At the moment the announcements bear little relationship to what the server is actually offering: they always offer a Media Server. It would be nice to actually parse the response from the server and set the correct announcements.
The real solution to this problem, would be a real SSDP proxy, which would collect announcements from one LAN, forward them to a program on another LAN which would manage the announcements on that LAN. Apparently this is harder than it seems, because I am aware that this has been looked into but I don't know of any solutions.
This solution also has the advantage that it doesn't require anything running on the remote LAN, as long as the remote device address is known.
Python multicast code taken from Stack Overflow (https://stackoverflow.com/questions/603852/multicast-in-python/1794373#1794373) by tolomea (https://stackoverflow.com/users/10471/tolomea)
Other example code taken from Stack Overflow by Toddeman, however it does not seem to be available any longer
Copyright (c) 2014-2020 Graham R. Cobb. This software is distributed under the GPL (see the copyright notices and the LICENSE file).
ssdp-fake is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
ssdp-fake is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.