[Android] Fix NetworkInterface.GetAllNetworkInterfaces

[simonrozsival]

Apparently, since Android API 30, the getifaddrs function returns only AF_INET and AF_INET6 addresses and doesn't return any AF_PACKET. The problem was that we allocated the memoryBlock in such a way that the interfaceList and the addressList overlapped and in the end both contained invalid data. We replaced the default implementation of getifaddrs with one from Xamarin (#71943) based on netlink but that turned out to be an insufficient fix and doesn't work on recent Android versions.

This PR fixes the allocation problem (see pal_interfaceaddresses.c:356-400 and removes the custom getifaddrs implementation in pal_ifaddrs.h and pal_ifaddrs.c.

Reverts #71943 and restores the previous implementation from #62780
Fixes #75809
Fixes #76493
Fixes dotnet/android#6973

Followed up by PR #76541

[ghost]

Tagging subscribers to 'arch-android': @steveisok, @akoeplinger
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Issue Details

---

Apparently, since Android API 30, the getifaddrs function returns only AP_INET and AP_INET6 addresses and doesn't return any AP_PACKET. The problem was that we allocated the memoryBlock in such a way that the interfaceList and the addressList overlapped and in the end both contained invalid data. We replaced the default implementation of getifaddrs with one from Xamarin (#71943) based on netlink but that turned out to be an insufficient fix and doesn't work on recent Android versions.

This PR fixes the allocation problem (see pal_interfaceaddresses.c:356-400 and removes the custom getifaddrs implementation in pal_ifaddrs.h and pal_ifaddrs.c.

Reverts #71943 and restores the previous implementation from #62780
Fixes #75809
Fixes dotnet/android#6973

Author:	simonrozsival
Assignees:	-
Labels:	os-android
Milestone:	-

[ghost]

Tagging subscribers to this area: @dotnet/ncl
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Apparently, since Android API 30, the getifaddrs function returns only AP_INET and AP_INET6 addresses and doesn't return any AP_PACKET. The problem was that we allocated the memoryBlock in such a way that the interfaceList and the addressList overlapped and in the end both contained invalid data. We replaced the default implementation of getifaddrs with one from Xamarin (#71943) based on netlink but that turned out to be an insufficient fix and doesn't work on recent Android versions.

This PR fixes the allocation problem (see pal_interfaceaddresses.c:356-400 and removes the custom getifaddrs implementation in pal_ifaddrs.h and pal_ifaddrs.c.

Reverts #71943 and restores the previous implementation from #62780
Fixes #75809
Fixes dotnet/android#6973

Author:	simonrozsival
Assignees:	-
Labels:	area-System.Net, os-android
Milestone:	-

[simonrozsival]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[simonrozsival]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[simonrozsival]

/azp run runtime-extra-platforms

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[simonrozsival]

Failing tests are unrelated to this PR and many of them are known issues:

• runtime:
  • System.Text.RegularExpressions.Tests.AttRegexTests test fails in CI #75808
  • System.Net.Quic.Functional.Tests - Helix timeout #75830
• runtime-extra-platforms:
  • 3 System.Diagnostics tests failing - System.FormatException : The input is not a valid Base-64 #76140
  • multiple linux-bionic tests timeouted
  • multiple tvOS tests timeouted

[steveisok]

/backport to release/6.0

[github-actions]

Started backporting to release/6.0: https://github.com/dotnet/runtime/actions/runs/3283870988

[github-actions]

@steveisok backporting to release/6.0 failed, the patch most likely resulted in conflicts:

$ git am --3way --ignore-whitespace --keep-non-patch changes.patch

Applying: Revert "[Android] Port getifaddrs implementation from Xamarin.Android (#71943)"
Using index info to reconstruct a base tree...
M	src/mono/cmake/config.h.in
A	src/native/libs/Common/pal_config.h.in
A	src/native/libs/System.Native/CMakeLists.txt
A	src/native/libs/System.Native/pal_ifaddrs.c
A	src/native/libs/System.Native/pal_ifaddrs.h
A	src/native/libs/System.Native/pal_interfaceaddresses.c
A	src/native/libs/configure.cmake
Falling back to patching base and 3-way merge...
Auto-merging src/mono/cmake/config.h.in
Auto-merging src/libraries/Native/Unix/configure.cmake
Auto-merging src/libraries/Native/Unix/System.Native/pal_interfaceaddresses.c
CONFLICT (rename/delete): src/native/libs/System.Native/pal_ifaddrs.h deleted in Revert "[Android] Port getifaddrs implementation from Xamarin.Android (#71943)" and renamed to src/libraries/Native/Unix/System.Native/pal_ifaddrs.h in HEAD. Version HEAD of src/libraries/Native/Unix/System.Native/pal_ifaddrs.h left in tree.
CONFLICT (rename/delete): src/native/libs/System.Native/pal_ifaddrs.c deleted in Revert "[Android] Port getifaddrs implementation from Xamarin.Android (#71943)" and renamed to src/libraries/Native/Unix/System.Native/pal_ifaddrs.c in HEAD. Version HEAD of src/libraries/Native/Unix/System.Native/pal_ifaddrs.c left in tree.
Auto-merging src/libraries/Native/Unix/System.Native/CMakeLists.txt
Auto-merging src/libraries/Native/Unix/Common/pal_config.h.in
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 Revert "[Android] Port getifaddrs implementation from Xamarin.Android (#71943)"
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[steveisok]

@simonrozsival When you have a moment, can you please try and backport this to release/6.0?