feat: add support for setting sACN interface by onerandomusername · Pull Request #107 · Breina/ha-artnet-led

onerandomusername · 2026-01-09T20:23:56Z

Partially closes #84.

Not fully tested since my sACN network is partially broken in a different and unique way.

I'm also bikeshedding the configuration name. Not sure if bind_ip makes more sense. Intentionally adding bind since I want to be able to support interface names too. For my usecase, I have a static IP and sometimes that static IP moves interfaces.

Some further testing is required as I think I've discovered a bug with the receiving server. https://stackoverflow.com/questions/46066244/what-is-the-purpose-and-result-of-using-inaddr-any. It binds to all but only registers itself with one interface.

Copilot

Pull request overview

This pull request adds support for configuring which network interface the sACN server should bind to for sending and receiving data. This is useful for Home Assistant installations with multiple network interfaces where DMX/sACN traffic should be isolated to a specific network.

Key Changes

Added interface_ip configuration option to specify the network interface by IP address
Updated socket binding logic to use the specified interface for both sending and receiving multicast traffic
Added documentation explaining when and how to use the new configuration option

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
tests/test_sacn_server.py	Added test assertions for the new `interface_ip` configuration field
docs/sacn-communication.md	Added documentation section explaining the `interface_ip` setting and when to use it
custom_components/dmx/setup/config_processor.py	Added `CONF_INTERFACE_IP` constant and validation schema for the new configuration option
custom_components/dmx/server/sacn_server.py	Implemented interface binding logic in both `SacnServer` and `SacnReceiver` classes
custom_components/dmx/protocols/sacn/protocol.py	Integrated `interface_ip` configuration into the sACN protocol setup
custom_components/dmx/protocols/base.py	Refactored to use constants instead of string literals (unrelated cleanup)

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docs/sacn-communication.md

custom_components/dmx/server/sacn_server.py

docs/sacn-communication.md

Copilot · 2026-01-09T20:28:24Z

custom_components/dmx/server/sacn_server.py

+                self.socket.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF, packed_interface)
+                self.running = True
+                log.info(f"sACN server started on {self.config.interface_ip}:{SACN_PORT}")
+            else:
+                self.running = True


The logic flow here is redundant. The self.running = True assignment is duplicated in both branches of the conditional. Consider moving it outside the conditional block to avoid duplication and improve maintainability. Additionally, the multicast interface configuration should be set regardless of whether an interface_ip is provided, as the socket binding already handles the interface selection.

Suggested change

self.socket.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF, packed_interface)

self.running = True

log.info(f"sACN server started on {self.config.interface_ip}:{SACN_PORT}")

else:

self.running = True

else:

# Use INADDR_ANY to allow the OS to choose the default multicast interface

packed_interface = struct.pack("=I", socket.INADDR_ANY)

self.socket.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF, packed_interface)

self.running = True

if self.config.interface_ip:

log.info(f"sACN server started on {self.config.interface_ip}:{SACN_PORT}")

else:

Hmm. This may be a bug that previously existed. 🤔

Do we want to bind and automatically default to registering the multicast groups on all interfaces, or only on the one interface? Right now the listener binds to all interfaces but only registers with IGMP on one the chosen by os interface. This is what happens in the refactor tree, even before this pull request.

custom_components/dmx/setup/config_processor.py

docs/sacn-communication.md

Copilot · 2026-01-09T20:28:25Z

custom_components/dmx/server/sacn_server.py

+                log.info(f"sACN server started on {self.config.interface_ip}:{SACN_PORT}")
+            else:
+                self.running = True
+                log.info(f"sACN server started on {SACN_PORT}")


The log message is misleading. The server binds to a random port (port 0 means the OS assigns a random available port), but the log message displays SACN_PORT (5568). The socket sends TO port 5568 on multicast addresses, but listens on a random port. The log message should either show the actual bound port by reading it from the socket, or clarify that it's sending to port 5568 rather than listening on it. Consider using self.socket.getsockname()[1] to get the actual bound port.

Might be worth updating the log. But I'm unsure if sockname works cross-platform (HA in docker, in a VM, bare-metal, ..).

onerandomusername · 2026-01-11T17:06:26Z

I have a commit to fix most of this copilot review (which I've also disabled for future pushes, I think) but haven't pushed it yet and am currently away from my PC. Can push later, I think.

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Breina · 2026-01-11T17:11:39Z

Alright thanks a lot! I'll test this as soon as I can, and then investigate #108 with it as we go.

Note that I've renamed ha-artnet-led to dmx in the manifest, since that name is no longer accurate since we support sACN as well.

Copilot

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 5 comments.

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Copilot · 2026-01-11T18:50:01Z

custom_components/dmx/server/sacn_server.py

-            self.running = True
-            log.info(f"sACN server started on port {SACN_PORT}")
+            if self.config.interface_ip:
+                packed_interface = socket.inet_aton(self.config.interface_ip)


The socket.inet_aton() call can raise OSError if the IP address is invalid. While there is a general exception handler, this specific error should be caught with a more descriptive error message to help users identify configuration issues, especially since the validation may not catch all edge cases.

Suggested change

packed_interface = socket.inet_aton(self.config.interface_ip)

try:

packed_interface = socket.inet_aton(self.config.interface_ip)

except OSError as exc:

log.error(

"Invalid interface_ip '%s' configured for sACN server. "

"Please check the DMX integration configuration.",

self.config.interface_ip,

)

raise ValueError(

f"Invalid interface_ip configured for sACN server: {self.config.interface_ip}"

) from exc

Copilot · 2026-01-11T18:50:01Z

custom_components/dmx/server/sacn_server.py

+            self.socket.bind((self.config.interface_ip or "", 0))

-            self.running = True
-            log.info(f"sACN server started on port {SACN_PORT}")
+            if self.config.interface_ip:
+                packed_interface = socket.inet_aton(self.config.interface_ip)
+                self.socket.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF, packed_interface)
+                self.running = True
+                log.info(f"sACN server started on {self.config.interface_ip}:{SACN_PORT}")
+            else:
+                self.running = True
+                log.info(f"sACN server started on {SACN_PORT}")


The actual behavior of binding to a specific interface IP and setting IP_MULTICAST_IF socket option lacks test coverage. While configuration tests exist, there should be tests verifying that the socket is correctly configured with the interface IP when specified.

Copilot · 2026-01-11T18:50:01Z

custom_components/dmx/server/sacn_server.py

+                if self.interface_ip:
+                    mreq = struct.pack("4s4s", socket.inet_aton(multicast_addr), socket.inet_aton(self.interface_ip))
+                else:
+                    mreq = struct.pack("4sl", socket.inet_aton(multicast_addr), socket.INADDR_ANY)


Similar to the sender, the socket.inet_aton() call in the receiver can raise OSError if the IP address is invalid. This should have more specific error handling to provide clear feedback to users about invalid interface IP configuration.

Suggested change

if self.interface_ip:

mreq = struct.pack("4s4s", socket.inet_aton(multicast_addr), socket.inet_aton(self.interface_ip))

else:

mreq = struct.pack("4sl", socket.inet_aton(multicast_addr), socket.INADDR_ANY)

try:

multicast_packed = socket.inet_aton(multicast_addr)

except OSError as err:

log.error(

"Invalid multicast address '%s' while trying to %s multicast group for universe %d: %s",

multicast_addr,

action.lower(),

universe_id,

err,

)

return

if self.interface_ip:

try:

interface_packed = socket.inet_aton(self.interface_ip)

except OSError as err:

log.error(

"Invalid interface IP '%s' while trying to %s multicast group %s for universe %d: %s",

self.interface_ip,

action.lower(),

multicast_addr,

universe_id,

err,

)

return

mreq = struct.pack("4s4s", multicast_packed, interface_packed)

else:

mreq = struct.pack("4sl", multicast_packed, socket.INADDR_ANY)

Copilot · 2026-01-11T18:50:02Z

custom_components/dmx/setup/config_processor.py

                vol.Optional(CONF_PRIORITY, default=CONF_PRIORITY_DEFAULT): vol.All(
                    vol.Coerce(int), vol.Range(min=0, max=200)
                ),
+                vol.Optional(CONF_INTERFACE_IP): cv.string,


The interface_ip configuration should use cv.ipv4 instead of cv.string to properly validate that the provided value is a valid IPv4 address. This prevents configuration errors from invalid IP addresses.

Suggested change

vol.Optional(CONF_INTERFACE_IP): cv.string,

vol.Optional(CONF_INTERFACE_IP): cv.ipv4,

Well, if true, that's more useful. Should probably unionize it with ipv6 and that should be sufficient.

This doesn't actually exist, as far as I can tell.

custom_components/dmx/server/sacn_server.py

Breina · 2026-01-25T16:53:15Z

Tested and looks OK! Thank you very much!

feat: add support for setting the sACN interface

be75a3e

Copilot AI review requested due to automatic review settings January 9, 2026 20:23

Copilot started reviewing on behalf of onerandomusername January 9, 2026 20:24 View session

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onerandomusername mentioned this pull request Jan 10, 2026

sACN data is spamming home assistant #108

Open

Breina and others added 2 commits January 11, 2026 18:08

Update docs/sacn-communication.md

0365c7b

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Update docs/sacn-communication.md

6dd31b2

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

doc updates

b0f2c35

onerandomusername requested a review from Copilot January 11, 2026 18:46

Copilot started reviewing on behalf of onerandomusername January 11, 2026 18:47 View session

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chore: dedupe self.running

60042fb

Breina merged commit 74bd928 into Breina:platform-refactor2 Jan 25, 2026
2 of 3 checks passed

onerandomusername deleted the sacn-interface branch February 4, 2026 14:53

-                packed_interface = socket.inet_aton(self.config.interface_ip)
+                try:
+                    packed_interface = socket.inet_aton(self.config.interface_ip)
+                except OSError as exc:
+                    log.error(
+                        "Invalid interface_ip '%s' configured for sACN server. "
+                        "Please check the DMX integration configuration.",
+                        self.config.interface_ip,
+                    )
+                    raise ValueError(
+                        f"Invalid interface_ip configured for sACN server: {self.config.interface_ip}"
+                    ) from exc

-                if self.interface_ip:
-                    mreq = struct.pack("4s4s", socket.inet_aton(multicast_addr), socket.inet_aton(self.interface_ip))
-                else:
-                    mreq = struct.pack("4sl", socket.inet_aton(multicast_addr), socket.INADDR_ANY)
+                try:
+                    multicast_packed = socket.inet_aton(multicast_addr)
+                except OSError as err:
+                    log.error(
+                        "Invalid multicast address '%s' while trying to %s multicast group for universe %d: %s",
+                        multicast_addr,
+                        action.lower(),
+                        universe_id,
+                        err,
+                    )
+                    return
+                if self.interface_ip:
+                    try:
+                        interface_packed = socket.inet_aton(self.interface_ip)
+                    except OSError as err:
+                        log.error(
+                            "Invalid interface IP '%s' while trying to %s multicast group %s for universe %d: %s",
+                            self.interface_ip,
+                            action.lower(),
+                            multicast_addr,
+                            universe_id,
+                            err,
+                        )
+                        return
+                    mreq = struct.pack("4s4s", multicast_packed, interface_packed)
+                else:
+                    mreq = struct.pack("4sl", multicast_packed, socket.INADDR_ANY)

	vol.Optional(CONF_INTERFACE_IP): cv.string,
	vol.Optional(CONF_INTERFACE_IP): cv.ipv4,

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Pull request overview

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