Add socket protocol+type validation

[josesimoes]

Description

• Now validates combination and throws on invalid ones.

Motivation and Context

• Found when running System.Net unit tests.
• lwIP silently ignores the protocol parameter for STREAM/DGRAM sockets, accepting invalid combinations.

How Has This Been Tested?

• Running System.Net unit tests.

Screenshots

Types of changes

• Improvement (non-breaking change that improves a feature, code or algorithm)
• Bug fix (non-breaking change which fixes an issue with code or algorithm)
• New feature (non-breaking change which adds functionality to code)
• Breaking change (fix or feature that would cause existing functionality to change)
• Config and build (change in the configuration and build system, has no impact on code or features)
• Dev Containers (changes related with Dev Containers, has no impact on code or features)
• Dependencies/declarations (update dependencies or assembly declarations and changes associated, has no impact on code or features)
• Documentation (changes or updates in the documentation, has no impact on code or features)

Checklist

• My code follows the code style of this project (only if there are changes in source code).
• My changes require an update to the documentation (there are changes that require the docs website to be updated).
• I have updated the documentation accordingly (the changes require an update on the docs in this repo).
• I have read the CONTRIBUTING document.
• I have tested everything locally and all new and existing tests passed (only if there are changes in source code).

[coderabbitai]

📝 Walkthrough

Walkthrough

LWIP_SOCKETS_Driver::Socket now validates supported socket type/protocol combinations and returns EPROTONOSUPPORT for invalid pairs before continuing socket creation.

Changes

Socket protocol validation

Layer / File(s)	Summary
Validate socket protocol combinations src/PAL/Lwip/lwIP_Sockets.cpp	SOCK_STREAM accepts TCP or IP, and SOCK_DGRAM accepts UDP or IP; unsupported combinations return EPROTONOSUPPORT before lwIP socket creation.

Estimated code review effort: 2 (Simple) | ~5 minutes

Suggested labels: Type: bug

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly summarizes the socket protocol/type validation change and meets the length and punctuation requirements.
Description check	✅ Passed	The description matches the code change and testing context, so it is clearly related to the pull request.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}