Device discovery requires a fixed timeout

[zehnm]

Issue: no overall discovery timeout like 30sec, but a socket read timeout while receiving SSDP records. With many devices this can easily take over a minute and the UI times out!

This happens to me now, with just 2 Sonos, 1 LG TV, 1 Hue Bridge and an AVR. Not really a big setup, but the discovery almost always times out. Even if the integration discovered the AVR, I can't finish the setup process.

The socket read timeout cannot be used for a discovery timeout. You might get 100 devices, and the first ones start sending messages again, while still processing the remaining records.

Another issue which increases the discovery timeout is #4:

• Lots of devices are discovered which match the search query, like Sonos, LG, Hue, ...
• Each device (IP address to be precise) is used to try creating denonavr.DenonAVR(ipaddress).
• The denonavr library then tries to fetch all required information. In my environment this takes around 2-3 seconds for the Hue bridge alone. And the Hue bridge sends a record every few seconds! This is the time between these two log messages:

DEBUG:avr:Trying to get device info for 172.16.16.5
ERROR:avr:Failed to get device info. Maybe not a Denon device.

--> the number of attempts to create a DenonAVR object for every found SSDP record has to be decreased! Suggestion: create a list of well known header keys of 3rd party devices, that can be immediatly filtered out.

Known headers so far:

• hue-bridgeid: Philips Hue bridge
• X-RINCON-HOUSEHOLD: Sonos speakers
• DLNADeviceName.lge.com: LG TV

TODO study SSDP protocol and HA implementation.
It would be great if Denon receivers could be clearly identifiable either by:

• USN: The unique service name to identify the device.
  --> is that just the generic upnp service?
• SERVER: The server system information value providing information in the following format: [OS-Name] UPnP/[Version] [Product-Name]/[Product-Version].
  --> is OS-Nameusable?
  Probably the XML file has to be loaded from LOCATION and parsed for the required information...

Home Assistant has a central SSDP discovery:

• An integration driver can specifiy in it's manifest file, which responses it wants to receive (or which ones will be associated to that integration).
• https://github.com/home-assistant/core/blob/2023.10.3/homeassistant/components/denonavr/manifest.json#L10-L59
• https://developers.home-assistant.io/docs/network_discovery/#ssdp
• HA Denon integration SSDP filtering: https://github.com/home-assistant/core/blob/2023.10.3/homeassistant/components/denonavr/config_flow.py#L233-L261
  • the manufacturer field is loaded from the LOCATION source: https://github.com/home-assistant/core/blob/2023.10.3/homeassistant/components/ssdp/__init__.py#L559-L570
  • https://github.com/StevenLooman/async_upnp_client/blob/30f9588608e1bec4267de34b11304cd5235dab21/async_upnp_client/description_cache.py#L84
  • https://github.com/StevenLooman/async_upnp_client/blob/30f9588608e1bec4267de34b11304cd5235dab21/async_upnp_client/description_cache.py#L103

[zehnm]

The denonavr library already comes with its own SSDP discovery function async_identify_denonavr_receivers: https://github.com/ol-iver/denonavr/blob/0.11.4/denonavr/ssdp.py#L81

Why not use this one?