[dns-sd] Add support for service subtypes on Thread devices

[Damian-Nordic]

Problem

Our OpenThread-based DNS-SD Advertiser implementation does not support service subtypes while it is necessary to enable commissionable node advertising for Thread devices.

Change overview

• Extend the existing ThreadStackManager::AddSrpService method to support additional service subtypes.
• Fix subtype-related constants in Advertiser.h
• Clean up the existing code a bit by adding begin()/end() methods to Span.

Testing

Tested using nRF Connect Lock example with manually enabled commissionable node advertising:

• Verified using ot srp client service shell command that a proper service is registered
• Verified E2E with a modified OpenThread Border Router (I made another PR to otbr-posix).

Note:
@jmartinez-silabs @doru91 @tima-q you will need to update OpenThread soon to make use of this addition on your platforms.

[todo]

use fixed buffer allocator to reduce the memory footprint from N*M to sum(M_i)

connectedhomeip/src/platform/OpenThread/GenericThreadStackManagerImpl_OpenThread.h

Lines 138 to 144 in 228b170

	// TODO: use fixed buffer allocator to reduce the memory footprint from N*M to sum(M_i)
	char mSubTypeBuffers[chip::Mdns::kSubTypeMaxNumber][chip::Mdns::kSubTypeMaxLength + 1];
	const char * mSubTypes[chip::Mdns::kSubTypeMaxNumber + 1]; // extra entry for nullptr at the end
	#endif
	otDnsTxtEntry mTxtEntries[kMaxTxtEntriesNumber];
	uint8_t mTxtValueBuffers[kMaxTxtEntriesNumber][kMaxTxtValueSize];
	char mTxtKeyBuffers[kMaxTxtEntriesNumber][kMaxTxtKeySize];

---

This comment was generated by todo based on a TODO comment in 228b170 in #8252. cc @Damian-Nordic.

[tima-q]

@Damian-Nordic Happy to accomodate this new feature, but can you advise to which OpenThread commit you bumped for this ? At your side this get's updated through Zephyr I assume.
btw I see another check for API_VERSION >= 126 in OpenThreadUtils.cpp - is the feature expected to work with anything in between ?

[Damian-Nordic]

We bumped OpenThread in Zephyr to 48b129 (API_VERSION == 134). The check for API_VERSION >= 126 was added because with that API version OpenThread switched from otMasterXXX to otNetworkXXX function naming.

[tima-q]

@Damian-Nordic Thanks - we will align to that commit to avoid OpenThread inconsistencies

[bzbarsky-apple]

/rebase

[github-actions]

Size increase report for "gn_qpg-example-build" from 13888a6

File	Section	File	VM
chip-qpg6100-lighting-example.out	.text	16	16

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-qpg6100-lighting-example.out and ./pull_artifact/chip-qpg6100-lighting-example.out:

sections,vmsize,filesize
.debug_info,0,16296
.debug_str,0,1221
.debug_loc,0,161
.debug_abbrev,0,75
.debug_line,0,51
.strtab,0,25
.text,16,16
.shstrtab,0,-1
[Unmapped],0,-16
.debug_ranges,0,-32

Comparing ./master_artifact/chip-qpg6100-lighting-example.out.map and ./pull_artifact/chip-qpg6100-lighting-example.out.map:

BLOAT EXECUTION FAILED WITH CODE 1:
bloaty: unknown file type for file './pull_artifact/chip-qpg6100-lighting-example.out.map'

[github-actions]

Size increase report for "esp32-example-build" from 13888a6

File	Section	File	VM
chip-temperature-measurement-app.elf	.flash.text	-56	-56

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-all-clusters-app.elf and ./pull_artifact/chip-all-clusters-app.elf:

sections,vmsize,filesize
.debug_info,0,15948
.debug_str,0,234
.debug_abbrev,0,55
.debug_loc,0,13
.debug_line,0,6

Comparing ./master_artifact/chip-shell.elf and ./pull_artifact/chip-shell.elf:

sections,vmsize,filesize
.debug_info,0,2640
.debug_str,0,139
.debug_line,0,1

Comparing ./master_artifact/chip-pigweed-app.elf and ./pull_artifact/chip-pigweed-app.elf:

sections,vmsize,filesize

Comparing ./master_artifact/chip-temperature-measurement-app.elf and ./pull_artifact/chip-temperature-measurement-app.elf:

sections,vmsize,filesize
.debug_info,0,12314
.debug_str,0,238
[Unmapped],0,56
.debug_abbrev,0,55
.debug_loc,0,7
.debug_line,0,6
.flash.text,-56,-56

Comparing ./master_artifact/chip-lock-app.elf and ./pull_artifact/chip-lock-app.elf:

sections,vmsize,filesize
.debug_info,0,13553
.debug_str,0,234
.debug_abbrev,0,56
.debug_line,0,6
.debug_loc,0,-1

Comparing ./master_artifact/chip-persistent-storage.elf and ./pull_artifact/chip-persistent-storage.elf:

sections,vmsize,filesize

[github-actions]

Size increase report for "nrfconnect-example-build" from 13888a6

File	Section	File	VM
chip-shell.elf	bss	0	243
chip-shell.elf	text	128	128
chip-shell.elf	[LOAD #3 [RW]]	0	-19
chip-lock.elf	bss	0	224
chip-lock.elf	text	128	128

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-shell.elf and ./pull_artifact/chip-shell.elf:

sections,vmsize,filesize
.debug_info,0,7819
.debug_str,0,1156
.debug_loc,0,944
bss,243,0
.debug_line,0,232
text,128,128
.strtab,0,25
.debug_ranges,0,16
.shstrtab,0,3
.debug_abbrev,0,1
[LOAD #3 [RW]],-19,0

Comparing ./master_artifact/chip-lock.elf and ./pull_artifact/chip-lock.elf:

sections,vmsize,filesize
.debug_info,0,18714
.debug_str,0,1254
.debug_loc,0,962
.debug_line,0,234
bss,224,0
text,128,128
.strtab,0,25
.debug_abbrev,0,20
.debug_ranges,0,16
.shstrtab,0,-1

[LuDuda]

LGTM 👍