Always reply additional data to all queries

[andy31415]

Problem

MinMDNS provides additional records only for ANY queries.
For example if a PTR query is made, it would not reply with SRV/A/AAAA replies.

RFC 1035 describes the additional records as "the additional records section contains RRs which relate to the query, but are not strictly answers for the question." (i.e. match is not enforced)

We found that some legacy MDNS in android code which use 'PTR' queries instead of ANY and refuse to see chip devices without this (they see the PTR reply but without SRV and A/AAAA it cannot connect even though PTR and SRV are supposed to be optional)

https://datatracker.ietf.org/doc/html/rfc6763#section-12 describes what things SHOULD be added to additional records and PTR should also have SRV/A/AAAA (and SRV should have A/AAAA)

Change overview

Enable additional records regardless of query type (i.e. a PTR query will still receive additional data of different types if required)

Testing

Manual minmdns example running.

[andy31415]

fast track: trivial change, CI exercises this a lot (entire linux testing CI runs using mdns discovery using minmdns), validated manually

[github-actions]

PR #12413: Size comparison from 18f959b to 03c2fcc

Decreases (12 builds for esp32, linux, mbed, p6)

platform	target	config	section	18f959b	03c2fcc	change	% change
esp32	all-clusters-app	c3devkit	(read only)	837376	837370	-6	-0.0
			.flash.text	837376	837370	-6	-0.0
		m5stack	(read only)	908883	908875	-8	-0.0
			.flash.text	903499	903491	-8	-0.0
linux	all-clusters-app	debug	(read only)	1780313	1780281	-32	-0.0
			.text	1500738	1500706	-32	-0.0
	bridge-app	debug+rpc	(read only)	1352373	1352341	-32	-0.0
			.text	1138181	1138149	-32	-0.0
	chip-tool	debug	(read only)	6266389	6266357	-32	-0.0
			.text	5568293	5568261	-32	-0.0
	lighting-app	debug+rpc	(read only)	1632441	1632409	-32	-0.0
			.text	1362098	1362066	-32	-0.0
	ota-provider-app	debug	(read only)	1312817	1312785	-32	-0.0
			.text	1097186	1097154	-32	-0.0
	ota-requestor-app	debug	(read only)	1412801	1412769	-32	-0.0
			.text	1181906	1181874	-32	-0.0
	tv-app	debug	(read only)	1927025	1926993	-32	-0.0
			.text	1616914	1616882	-32	-0.0
mbed	lighting-app	CY8CPROTO_062_4343W+release	(read/write)	2281312	2281248	-64	-0.0
			.text	1243912	1243848	-64	-0.0
p6	all-clusters-app	default	(read/write)	2318288	2318272	-16	-0.0
			.text	1276552	1276536	-16	-0.0
	lock-app	default	(read/write)	2229528	2229512	-16	-0.0
			.text	1187792	1187776	-16	-0.0

Full report (38 builds for efr32, esp32, k32w, linux, mbed, nrfconnect, p6, qpg, telink)

platform	target	config	section	18f959b	03c2fcc	change	% change
efr32	lighting-app	BRD4161A	(read only)	763688	763688	0	0.0
			(read/write)	119972	119972	0	0.0
			.bss	118164	118164	0	0.0
			.data	1808	1808	0	0.0
			.text	763680	763680	0	0.0
		BRD4161A+rpc	(read only)	792184	792184	0	0.0
			(read/write)	138276	138276	0	0.0
			.bss	136364	136364	0	0.0
			.data	1908	1908	0	0.0
			.text	792176	792176	0	0.0
	lock-app	BRD4161A	(read only)	737552	737552	0	0.0
			(read/write)	117684	117684	0	0.0
			.bss	115916	115916	0	0.0
			.data	1764	1764	0	0.0
			.text	737544	737544	0	0.0
	window-app	BRD4161A	(read only)	740656	740656	0	0.0
			(read/write)	118116	118116	0	0.0
			.bss	116340	116340	0	0.0
			.data	1772	1772	0	0.0
			.text	740648	740648	0	0.0
esp32	all-clusters-app	c3devkit	(read only)	837376	837370	-6	-0.0
			(read/write)	1224330	1224330	0	0.0
			.dram0.bss	58528	58528	0	0.0
			.dram0.data	14028	14028	0	0.0
			.flash.rodata	166528	166528	0	0.0
			.flash.text	837376	837370	-6	-0.0
			.iram0.text	61394	61394	0	0.0
		m5stack	(read only)	908883	908875	-8	-0.0
			(read/write)	423572	423572	0	0.0
			.dram0.bss	63928	63928	0	0.0
			.dram0.data	34000	34000	0	0.0
			.flash.rodata	194364	194364	0	0.0
			.flash.text	903499	903491	-8	-0.0
			.iram0.text	122943	122943	0	0.0
k32w	lighting-app	k32w061+se05x+release	(read/write)	724508	724508	0	0.0
			.bss	78772	78772	0	0.0
			.data	1840	1840	0	0.0
			.text	638096	638096	0	0.0
	lock-app	k32w061+debug	(read/write)	613492	613492	0	0.0
			.bss	69212	69212	0	0.0
			.data	1804	1804	0	0.0
			.text	536676	536676	0	0.0
	shell	k32w061+debug	(read/write)	679288	679288	0	0.0
			.bss	80796	80796	0	0.0
			.data	1776	1776	0	0.0
			.text	590916	590916	0	0.0
linux	all-clusters-app	debug	(read only)	1780313	1780281	-32	-0.0
			(read/write)	125160	125160	0	0.0
			.bss	53072	53072	0	0.0
			.data	1104	1104	0	0.0
			.data.rel.ro	65696	65696	0	0.0
			.dynamic	592	592	0	0.0
			.got	4112	4112	0	0.0
			.init	27	27	0	0.0
			.init_array	560	560	0	0.0
			.rodata	139957	139957	0	0.0
			.text	1500738	1500706	-32	-0.0
	bridge-app	debug+rpc	(read only)	1352373	1352341	-32	-0.0
			(read/write)	71312	71312	0	0.0
			.bss	35120	35120	0	0.0
			.data	1680	1680	0	0.0
			.data.rel.ro	29488	29488	0	0.0
			.dynamic	592	592	0	0.0
			.got	3984	3984	0	0.0
			.init	27	27	0	0.0
			.init_array	408	408	0	0.0
			.rodata	113980	113980	0	0.0
			.text	1138181	1138149	-32	-0.0
	chip-tool	debug	(read only)	6266389	6266357	-32	-0.0
			(read/write)	197648	197648	0	0.0
			.bss	33448	33448	0	0.0
			.data	1008	1008	0	0.0
			.data.rel.ro	157608	157608	0	0.0
			.dynamic	592	592	0	0.0
			.got	4472	4472	0	0.0
			.init	27	27	0	0.0
			.init_array	480	480	0	0.0
			.rodata	295752	295752	0	0.0
			.text	5568293	5568261	-32	-0.0
	lighting-app	debug+rpc	(read only)	1632441	1632409	-32	-0.0
			(read/write)	104400	104400	0	0.0
			.bss	40784	40784	0	0.0
			.data	1232	1232	0	0.0
			.data.rel.ro	57072	57072	0	0.0
			.dynamic	608	608	0	0.0
			.got	4136	4136	0	0.0
			.init	27	27	0	0.0
			.init_array	536	536	0	0.0
			.rodata	132433	132433	0	0.0
			.text	1362098	1362066	-32	-0.0
	ota-provider-app	debug	(read only)	1312817	1312785	-32	-0.0
			(read/write)	69768	69768	0	0.0
			.bss	37696	37696	0	0.0
			.data	912	912	0	0.0
			.data.rel.ro	26024	26024	0	0.0
			.dynamic	592	592	0	0.0
			.got	4048	4048	0	0.0
			.init	27	27	0	0.0
			.init_array	448	448	0	0.0
			.rodata	115184	115184	0	0.0
			.text	1097186	1097154	-32	-0.0
	ota-requestor-app	debug	(read only)	1412801	1412769	-32	-0.0
			(read/write)	73664	73664	0	0.0
			.bss	39808	39808	0	0.0
			.data	976	976	0	0.0
			.data.rel.ro	27736	27736	0	0.0
			.dynamic	592	592	0	0.0
			.got	4032	4032	0	0.0
			.init	27	27	0	0.0
			.init_array	472	472	0	0.0
			.rodata	127008	127008	0	0.0
			.text	1181906	1181874	-32	-0.0
	shell	debug	(read only)	805881	805881	0	0.0
			(read/write)	59848	59848	0	0.0
			.bss	16808	16808	0	0.0
			.data	240	240	0	0.0
			.data.rel.ro	38320	38320	0	0.0
			.dynamic	592	592	0	0.0
			.got	3504	3504	0	0.0
			.init	27	27	0	0.0
			.init_array	344	344	0	0.0
			.rodata	79954	79954	0	0.0
			.text	620610	620610	0	0.0
	tv-app	debug	(read only)	1927025	1926993	-32	-0.0
			(read/write)	314032	314032	0	0.0
			.bss	245176	245176	0	0.0
			.data	1504	1504	0	0.0
			.data.rel.ro	61696	61696	0	0.0
			.dynamic	592	592	0	0.0
			.got	4424	4424	0	0.0
			.init	27	27	0	0.0
			.init_array	624	624	0	0.0
			.rodata	161576	161576	0	0.0
			.text	1616914	1616882	-32	-0.0
mbed	all-clusters-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2296552	2296552	0	0.0
			.bss	181612	181612	0	0.0
			.data	5168	5168	0	0.0
			.heap	849664	849664	0	0.0
			.text	1259152	1259152	0	0.0
	lighting-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2281312	2281248	-64	-0.0
			.bss	172636	172636	0	0.0
			.data	5480	5480	0	0.0
			.heap	858328	858328	0	0.0
			.text	1243912	1243848	-64	-0.0
	lock-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2254344	2254344	0	0.0
			.bss	171452	171452	0	0.0
			.data	5464	5464	0	0.0
			.heap	859528	859528	0	0.0
			.text	1216944	1216944	0	0.0
	pigweed-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	1139744	1139744	0	0.0
			.bss	11752	11752	0	0.0
			.data	4368	4368	0	0.0
			.heap	1020328	1020328	0	0.0
			.text	103128	103128	0	0.0
	shell	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2046096	2046096	0	0.0
			.bss	156592	156592	0	0.0
			.data	4864	4864	0	0.0
			.heap	874992	874992	0	0.0
			.text	1008696	1008696	0	0.0
nrfconnect	lighting-app	nrf52840dk_nrf52840	(read/write)	876791	876791	0	0.0
			bss	113136	113136	0	0.0
			rodata	97368	97368	0	0.0
			text	590740	590740	0	0.0
		nrf52840dk_nrf52840+rpc	(read/write)	839239	839239	0	0.0
			bss	109488	109488	0	0.0
			rodata	88632	88632	0	0.0
			text	564908	564908	0	0.0
		nrf5340dk_nrf5340_cpuapp	(read/write)	801810	801810	0	0.0
			bss	114512	114512	0	0.0
			rodata	92628	92628	0	0.0
			text	520196	520196	0	0.0
	lock-app	nrf52840dk_nrf52840	(read/write)	847603	847603	0	0.0
			bss	110176	110176	0	0.0
			rodata	93108	93108	0	0.0
			text	568988	568988	0	0.0
		nrf5340dk_nrf5340_cpuapp	(read/write)	772874	772874	0	0.0
			bss	111584	111584	0	0.0
			rodata	88396	88396	0	0.0
			text	498536	498536	0	0.0
	pigweed-app	nrf52840dk_nrf52840	(read/write)	497327	497327	0	0.0
			bss	51824	51824	0	0.0
			rodata	45780	45780	0	0.0
			text	339436	339436	0	0.0
	pump-app	nrf52840dk_nrf52840	(read/write)	853647	853647	0	0.0
			bss	110312	110312	0	0.0
			rodata	94840	94840	0	0.0
			text	573052	573052	0	0.0
	pump-controller-app	nrf52840dk_nrf52840	(read/write)	846711	846711	0	0.0
			bss	110188	110188	0	0.0
			rodata	92976	92976	0	0.0
			text	568112	568112	0	0.0
	shell	nrf52840dk_nrf52840	(read/write)	779163	779163	0	0.0
			bss	109616	109616	0	0.0
			rodata	73216	73216	0	0.0
			text	521832	521832	0	0.0
		nrf5340dk_nrf5340_cpuapp	(read/write)	694210	694210	0	0.0
			bss	110600	110600	0	0.0
			rodata	67860	67860	0	0.0
			text	442444	442444	0	0.0
p6	all-clusters-app	default	(read/write)	2318288	2318272	-16	-0.0
			.bss	109688	109688	0	0.0
			.data	2456	2456	0	0.0
			.heap	921200	921200	0	0.0
			.text	1276552	1276536	-16	-0.0
	lock-app	default	(read/write)	2229528	2229512	-16	-0.0
			.bss	96408	96408	0	0.0
			.data	2280	2280	0	0.0
			.heap	934656	934656	0	0.0
			.text	1187792	1187776	-16	-0.0
qpg	lighting-app	qpg6100+debug	(read only)	496860	496860	0	0.0
			(read/write)	114140	114140	0	0.0
			.bss	79656	79656	0	0.0
			.data	940	940	0	0.0
			.text	491540	491540	0	0.0
	lock-app	qpg6100+debug	(read only)	469448	469448	0	0.0
			(read/write)	114140	114140	0	0.0
			.bss	78568	78568	0	0.0
			.data	892	892	0	0.0
			.text	464128	464128	0	0.0
	persistent-storage-app	qpg6100+debug	(read only)	108020	108020	0	0.0
			(read/write)	114140	114140	0	0.0
			.bss	36688	36688	0	0.0
			.data	292	292	0	0.0
			.text	102700	102700	0	0.0
telink	lighting-app	tlsr9518adk80d	(read/write)	778614	778614	0	0.0
			bss	79716	79716	0	0.0
			noinit	37160	37160	0	0.0
			text	541394	541394	0	0.0