net: add setTypeOfService and getTypeOfService to Socket

[amyssnippet]

this PR implements socket.setTOS(tos) and socket.getTOS() in net.Socket. it needed this to support DSCP tagging (QoS) for traffic prioritization, which wasn't previously exposed in the JS API. for the implementation:

• I added the logic in tcp_wrap.cc to attempt IP_TOS first, and fallback to IPV6_TCLASS if that fails. This handles both IPv4 and IPv6 sockets automatically without needing a separate flag.
• Windows returns UV_ENOSYS for now since the headers/implementation differ there.
• Added a new test file (test-net-socket-tos.js) to verify input validation and ensure the values are actually set on supported platforms.

Fixes: #61489

[nodejs-github-bot]

Review requested:

• @nodejs/net

[mcollina]

Good work. Can you add the documentation?

[amyssnippet]

Thanks @mcollina , is this ready to be merged? Please let me know if there is anything else you need me to adjust.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/71012/

[ronag]

@mcollina I'm confused by the CI failures. Any ideas? Or just flaky?

[mcollina]

lgtm but there are still a few comments to solve

[amyssnippet]

@mcollina likely the renaming ones right??

i have pushed the changes regarding the renaming ones, have a look at it, i was just waiting to see that all ci checks are running properly or not for all platforms.

[amyssnippet]

i have changed the names of files, can you please rerun the ci checks, so i can know if any issue is still there or not??

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/71113/

[amyssnippet]

i agree that 1 ci failure is caused due to me but it has a valid reason, semantic versioning. i dont know what version to add in the net.md documentation, i am totally unaware of that, kindly guide me that which version should i add here

same for ADDME too

below ci failures are flaky

no space left on device

not related to my changes

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/71121/

[amyssnippet]

i checked the failing console logs of the ci failures, and thats totally flaky, kindly consider running the ci tests of github actions, and lets moove forward merging. Thank You!

[juanarbol]

i checked the failing console logs of the ci failures, and thats totally flaky, kindly consider running the ci tests of github actions, and lets moove forward merging. Thank You!

We can't, let me re-trigger the CI

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/71122/

[amyssnippet]

We can't, let me re-trigger the CI

but its all flaky, totally unrelated to my changes

[juanarbol]

totally unrelated to my changes

I know, but we can't land when CI is not happy. No worries, your changes will land soon-ish :)

[amyssnippet]

@juanarbol i guess its due to overhead use of the jenkins ci system. you can check each and every logs i have cited them here. its not my code fault its systems fault.

Failures:

1. [Finished Build : #21908 of Job : node-test-commit-arm-debug with status : FAILURE at 11:44:37](https://ci.nodejs.org/job/node-test-commit-arm-debug/21908/nodes=ubuntu2404_debug-arm64/console) - reason No space left on device

2. [Finished Build : #61939 of Job : node-test-commit-arm with status : FAILURE at 12:01:39](https://ci.nodejs.org/job/node-test-commit-arm/61939/nodes=ubuntu2404-arm64/console) - same reason no space left on device

even unstable build failures are due to the system cant run programs like git

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/71124/