sddp-discovery-protocol
Advanced tools
Implementation of Control4's Simple Device Discovery Protocol (SDDP)
A command-line tool and API for servers and clients of Control4's Simple Device Discovery Protocol (SDDP).
Simple Device Discovery Protocol (SDDP) is a simple multicast discovery protocol implemented by many "smart home" devices to allow a controlling agent to easily discover and connect to devices on a local subnet.
SDDP was created by Control4, a provider of whole-home automation systems. While it is quite similar to UPnP's standard Simple Service Discovery Protocol (SSDP--note the similar but different spelling), and it serves a virtually identical purpose, SDDP is not a standard protocol and it is not publicly documented. The protocol as implemented by this package was inferred through observation of network traffic
Controllable smart devices implement the server side of the SDDP protocol. They listen on a well-known UDP multicast address 239.255.255.250:1902, and do the following:
Periodically (typically every 20 minutes) send an SDDP NOTIFY packet to the multicast address advertising their presence. An example of such a packet is:
NOTIFY ALIVE SDDP/1.0\r\n
From: "192.168.4.237:1902"\r\n
Host: "JVC_PROJECTOR-E0DADC152802"\r\n
Max-Age: 1800\r\n
Type: "JVCKENWOOD:Projector"\r\n
Primary-Proxy: "projector"\r\n
Proxies: "projector"\r\n
Manufacturer: "JVCKENWOOD"\r\n
Model: "DLA-RS3100_NZ8"\r\n
Driver: "projector_JVCKENWOOD_DLA-RS3100_NZ8.c4i"\r\n
Note that, as with all SDDP packets, there is a statement line, followed by some header lines, each separated with "\r\n". Formatting of the headers is with the same rules as HTTP headers. All string header values are enclosed in double quotes. This package assumes that json.loads() will correctly decode all header values.
Receive SDDP NOTIFY packets sent to the multicast address from other devices. Most devices will probably discard these unless they are interested in seeing other devices come and go
Receive and respond to SDDP SEARCH packets sent to the multicast address by clients that are performing discovery. An example of such a search packet is:
SEARCH * SDDP/1.0\r\n
Host: "192.168.4.237:24378"\r\n
The device will respond to a valid SEARCH request packet with a SEARCH response packet sent from their own unicast address on port 1902 to the unicast address from which the request came. The response looks very much like the NOTIFY packet, but the statement line is different; e.g.,:
SDDP/1.0 200 OK\r\n
From: "192.168.4.237:1902"\r\n
Host: "JVC_PROJECTOR-E0DADC152802"\r\n
Max-Age: 1800\r\n
Type: "JVCKENWOOD:Projector"\r\n
Primary-Proxy: "projector"\r\n
Proxies: "projector"\r\n
Manufacturer: "JVCKENWOOD"\r\n
Model: "DLA-RS3100_NZ8"\r\n
Driver: "projector_JVCKENWOOD_DLA-RS3100_NZ8.c4i"\r\n
Apps that wish to discover devices on the local subnet implement the client side of SDDP. They send from and receive on an arbitrary dynamic UDP port on their unicast address.
To perform discovery, an SDDP client sends an SDDP SEARCH packet from its unicast address and port to to the SDDP multicast address 239.255.255.250:1902; e.g.:
SEARCH * SDDP/1.0\r\n
Host: "192.168.4.237:24378"\r\n
where the 'Host' header is set to the client's unicast address and port.
Each SDDP server device on the network will immediately respond to the SEARCH packet with a SEARCH response packet sent directly to the client's unicast address and port; e.g.,:
SDDP/1.0 200 OK\r\n
From: "192.168.4.237:1902"\r\n
Host: "JVC_PROJECTOR-E0DADC152802"\r\n
Max-Age: 1800\r\n
Type: "JVCKENWOOD:Projector"\r\n
Primary-Proxy: "projector"\r\n
Proxies: "projector"\r\n
Manufacturer: "JVCKENWOOD"\r\n
Model: "DLA-RS3100_NZ8"\r\n
Driver: "projector_JVCKENWOOD_DLA-RS3100_NZ8.c4i"\r\n
The client will then collect the responses from all server devices and use them for discovery.
The client waits for an arbitrary period of time (by default, in this package, 3 seconds) before assuming that all devices have responded.
Python package sddp-discovery-protocol provides a command-line tool as well as a runtime API for implementing the client and server sides of SDDP.
Some key features of sddp-discovery-protocol:
Python: Python 3.8+ is required. See your OS documentation for instructions.
The current released version of sddp-discovery-protocol can be installed with
pip3 install sddp-discovery-protocol
Poetry is required; it can be installed with:
curl -sSL https://install.python-poetry.org | python3 -
Clone the repository and install sddp-discovery-protocol into a private virtualenv with:
cd <parent-folder>
git clone https://github.com/sammck/sddp-discovery-protocol.git
cd sddp-discovery-protocol
poetry install
You can then launch a bash shell with the virtualenv activated using:
poetry shell
There is a single command tool sddp that is installed with the package.
$ sddp version
0.1.0
$
$ sddp search --help
usage: sddp search [-h] [--pattern PATTERN] [--wait-time WAIT_TIME] [-b BIND_ADDRESSES] [--include-error-responses]
Search for SDDP devices
options:
-h, --help show this help message and exit
--pattern PATTERN The device pattern to search for. Default: "*"
--wait-time WAIT_TIME
The amount of time to wait for responses, in seconds. Default: 3.0
-b BIND_ADDRESSES, --bind BIND_ADDRESSES
The local unicast IP address to bind to. May be repeated. Default: all local non-loopback unicast addresses.
--include-error-responses
Include error responses in the output. Default: False
$ sddp search
[
{
"headers": {
"Driver": "repeater_ip_lutron_radiora2.c4i",
"From": "192.168.4.201:1902",
"Host": "lutron-032e345c",
"Manufacturer": "Lutron",
"Max-Age": 1800,
"Model": "RadioRA2 Main Repeater",
"Primary-Proxy": "repeater_ip_lutron_radiora2",
"Proxies": "repeater_ip_lutron_radiora2",
"Type": "lutron:repeater_ip_lutron_radiora2"
},
"local_addr": "192.168.4.238:59060",
"monotonic_time": 200338.359314361,
"sddp_version": "1.0",
"src_addr": "192.168.4.64:54838",
"status": "OK",
"status_code": 200,
"utc_time": "2023-07-24T00:13:30.734784"
},
{
"headers": {
"Driver": "sonos.c4z",
"From": "192.168.4.183:1902",
"Host": "Sonos-347E5CD9C83A",
"Manufacturer": "Sonos",
"Max-Age": 1800,
"Model": "Zoneplayer",
"Primary-Proxy": "media_service",
"Proxies": "media_service,amplifier",
"Type": "sonos:Zoneplayer"
},
"local_addr": "192.168.4.238:59060",
"monotonic_time": 200338.474668528,
"sddp_version": "1.0",
"src_addr": "192.168.4.183:55292",
"status": "OK",
"status_code": 200,
"utc_time": "2023-07-24T00:13:30.850138"
}
]
If you know the expected value of one or more response headers and are looking for a specific response, you can speed up the search in the successful case by applying a header filter and limiting the responses to 1; in this case the search will terminate as soon as the relevant response is received:
$ sddp search --max-responses 1 -F Type=JVCKENWOOD:Projector
{
"headers": {
"Driver": "projector_JVCKENWOOD_DLA-RS3100_NZ8.c4i",
"From": "192.168.4.237:1902",
"Host": "JVC_PROJECTOR-E0DADC152802",
"Manufacturer": "JVCKENWOOD",
"Max-Age": 1800,
"Model": "DLA-RS3100_NZ8",
"Primary-Proxy": "projector",
"Proxies": "projector",
"Type": "JVCKENWOOD:Projector"
},
"local_addr": "192.168.4.198:58941",
"monotonic_time": 0.093766125,
"sddp_version": "1.0",
"src_addr": "192.168.4.237:1902",
"status": "OK",
"status_code": 200,
"utc_time": "2023-07-24T22:23:54.175783"
}
$ sddp server --help
usage: sddp server [-h] [--advertise-interval ADVERTISE_INTERVAL] [-H HEADERS] [-b BIND_ADDRESSES]
Run an SDDP server
options:
-h, --help show this help message and exit
--advertise-interval ADVERTISE_INTERVAL
The interval at which to send device advertisements,
in seconds. Default: 2/3 of Max-Age header, or
1200 seconds (20 minutes)
-H HEADERS, --header HEADERS
A <name>=<value> header to include in the device
advertisement. May be repeated.
-b BIND_ADDRESSES, --bind BIND_ADDRESSES
The local unicast IP address to bind to.
May be repeated. Default: all local non-loopback
unicast addresses.
$ sddp --log-level=debug server
...
import logging
import asyncio
import sddp_discovery_protocol as sddp
#logging.basicConfig(level=logging.DEBUG)
async def amain():
# all parameters to SddpClient are optional; they allow you to set the IP addresses to bind to, etc.
async with sddp.SddpClient() as client:
# Entering the client.search() context manager sends the search multicast request and reliably collects responses.
# Parameters are optional; they allow you to set search filters, max wait time, max returned responses, etc.
async with client.search() as search_request:
# search_request.iter_responses() is an async generator that yields SddpResponseInfo objects
# as they come in until the max wait time has elapsed or the max number of responses has been received.
async for response_info in search_request.iter_responses():
print(response_info.datagram)
# It is possible to exit the loop early here if you found what you're looking for
loop = asyncio.new_event_loop()
try:
asyncio.set_event_loop(loop)
loop.run_until_complete(amain())
finally:
loop.close()
import logging
import asyncio
import sddp_discovery_protocol as sddp
logging.basicConfig(level=logging.DEBUG)
device_headers = {
"Type": "Acme:TestDevice",
"Primary-Proxy": "test-device",
"Proxies": "test-device",
"Manufacturer": "Acme",
"Model": "TestDevPlus",
"Driver": "test-device_Acme_TestDevPlus.c4i",
}
async def amain():
# The SddpServerContext manager starts the server listening on the multicast port, sending out advertisements,
# and responding to search requests. When the context manager exits, the server will be stopped.
async with sddp.SddpServer(device_headers=device_headers) as server:
# This will wait forever unless another task stops the server
await server.wait_for_done()
loop = asyncio.new_event_loop()
try:
asyncio.set_event_loop(loop)
loop.run_until_complete(amain())
finally:
loop.close()
Please report any problems/issues here.
Pull requests welcome.
sddp-discovery-protocol is distributed under the terms of the MIT License. The license applies to this file and other files in the GitHub repository hosting this file.
The author of sddp-discovery-protocol is Sam McKelvie.
FAQs
Implementation of Control4's Simple Device Discovery Protocol (SDDP)
We found that sddp-discovery-protocol demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Research
Security News
Socket’s threat research team has detected six malicious npm packages typosquatting popular libraries to insert SSH backdoors.
Security News
MITRE's 2024 CWE Top 25 highlights critical software vulnerabilities like XSS, SQL Injection, and CSRF, reflecting shifts due to a refined ranking methodology.
Security News
In this segment of the Risky Business podcast, Feross Aboukhadijeh and Patrick Gray discuss the challenges of tracking malware discovered in open source softare.