unix: Network entry API

[Rawk]

Description

Add functions and struct for the "get network entry" API, including the reentrant GNU extension.

Sources

glic/resolv/netdb.h

Checklist

• Relevant tests in libc-test/semver have been updated
• No placeholder or unstable values like *LAST or *MAX are included (see #3131)
• Tested locally (cd libc-test && cargo test --target mytarget);
  especially relevant for platforms that may not be checked in CI

@rustbot label +stable-nominated

[JohnTitor]

Also it'd be great if could prefer rebase over merge and squash commits into one.

View changes since this review

[JohnTitor]

I wonder if this had the same situation as setservent/endservent and we might need a test tweak.
cc @jclulow, @pfmooney for confirmation

libc/libc-test/build.rs

Line 1173 in a3e451c

"setservent" | "endservent" => true,

https://github.com/illumos/illumos-gate/blob/5425aa59e8fd3834b86390ed6d8a13586c918df9/usr/src/head/netdb.h#L288-L305

[JohnTitor]

@Rawk This hasn't been addressed at all.

[Rawk]

Oh, i see. I thought this was waiting on feedback from jclulow and pfmooney.

I am not sure about this. The workaround you refer to in

libc/libc-test/build.rs

Line 1173 in a3e451c

"setservent" | "endservent" => true,

is in fn test_solarish(), so i guess it is no longer relevant since i now limit this to unix/linux_like/linux?

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.

[Rawk]

The tests fails for Android because the symbol endnetent is missing. Probably others too, but i think the test stops after the first error.

How should i handle this situation? Should i move these new symbols to Linux specifically (src/unix/linux_like/linux/), or should they be disabled only for Android?

I have tried to run the docker tests locally but can't get it to run. It fails on missing libLLVM.so.22.1-rust-1.97.0-nightly.

Local log

$ ci/run-docker.sh arm-linux-androideabi
+ target=arm-linux-androideabi
++++ command -v cargo
+++ dirname /home/mawa/.cargo/bin/cargo
++ dirname /home/mawa/.cargo/bin
+ default_cargo_home=/home/mawa/.cargo
+ export CARGO_HOME=/home/mawa/.cargo
+ CARGO_HOME=/home/mawa/.cargo
+ echo /home/mawa
/home/mawa
+ pwd
/home/mawa/projects/upstream/libc-sys
+ '[' 0 '!=' 0 ']'
+ '[' -z arm-linux-androideabi ']'
+ run arm-linux-androideabi
+ run_target=arm-linux-androideabi
+ echo 'Building docker container for target arm-linux-androideabi'
Building docker container for target arm-linux-androideabi
+ build_args=("--tag=libc-$run_target" "--file=ci/docker/$run_target/Dockerfile" "ci/")
+ [[ arm-linux-androideabi = *\m\u\s\l* ]]
+ docker build --tag=libc-arm-linux-androideabi --file=ci/docker/arm-linux-androideabi/Dockerfile ci/
[+] Building 0.1s (16/16) FINISHED                                                                                                                                                                    docker:default
 => [internal] load build definition from Dockerfile                                                                                                                                                            0.0s
 => => transferring dockerfile: 1.35kB                                                                                                                                                                          0.0s
 => [internal] load metadata for docker.io/library/ubuntu:25.04                                                                                                                                                 0.0s
 => [internal] load .dockerignore                                                                                                                                                                               0.0s
 => => transferring context: 2B                                                                                                                                                                                 0.0s
 => [ 1/11] FROM docker.io/library/ubuntu:25.04                                                                                                                                                                 0.0s
 => [internal] load build context                                                                                                                                                                               0.0s
 => => transferring context: 212B                                                                                                                                                                               0.0s
 => CACHED [ 2/11] RUN dpkg --add-architecture i386                                                                                                                                                             0.0s
 => CACHED [ 3/11] RUN apt-get update && apt-get install -y --no-install-recommends     ca-certificates     expect     file     gcc     libc6-dev     libpulse0     libstdc++6:i386     openjdk-8-jre     pyth  0.0s
 => CACHED [ 4/11] WORKDIR /android/                                                                                                                                                                            0.0s
 => CACHED [ 5/11] COPY android* /android/                                                                                                                                                                      0.0s
 => CACHED [ 6/11] RUN /android/android-install-ndk.sh                                                                                                                                                          0.0s
 => CACHED [ 7/11] RUN /android/android-install-sdk.sh arm                                                                                                                                                      0.0s
 => CACHED [ 8/11] RUN mv /root/.android /tmp                                                                                                                                                                   0.0s
 => CACHED [ 9/11] RUN chmod 777 -R /tmp/.android                                                                                                                                                               0.0s
 => CACHED [10/11] RUN chmod 755 /android/sdk/cmdline-tools/tools/* /android/sdk/emulator/qemu/linux-x86_64/*                                                                                                   0.0s
 => CACHED [11/11] ADD runtest-android.rs /tmp/runtest.rs                                                                                                                                                       0.0s
 => exporting to image                                                                                                                                                                                          0.0s
 => => exporting layers                                                                                                                                                                                         0.0s
 => => writing image sha256:3874cd0d26de59382f361513c3c851b2796ddfd053c6a4c830277f4720e58ad0                                                                                                                    0.0s
 => => naming to docker.io/library/libc-arm-linux-androideabi                                                                                                                                                   0.0s
+ mkdir -p target
+ '[' -w /dev/kvm ']'
+ kvm='--volume /dev/kvm:/dev/kvm'
++ id -u
++ id -g
++ rustc --print sysroot
+ docker run --rm --user 1000:1000 --env LIBC_CI --env LIBC_CI_ZBUILD_STD --env RUSTFLAGS --env RUSTDOCFLAGS --env RUST_BACKTRACE --env RUST_LIBC_UNSTABLE_GNU_FILE_OFFSET_BITS --env RUST_LIBC_UNSTABLE_GNU_TIME_BITS --env RUST_LIBC_UNSTABLE_MUSL_V1_2_3 --env CARGO_TERM_COLOR --env CARGO_TERM_VERBOSE --env CARGO_HOME=/cargo --env CARGO_TARGET_DIR=/checkout/target --volume /home/mawa/.cargo:/cargo:Z --volume /home/mawa/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu:/rust:ro,Z --volume /home/mawa/projects/upstream/libc-sys:/checkout:ro,Z --volume /home/mawa/projects/upstream/libc-sys/target:/checkout/target --volume /dev/kvm:/dev/kvm --init --workdir /checkout libc-arm-linux-androideabi sh -c 'HOME=/tmp PATH=$PATH:/rust/bin exec ci/run.sh arm-linux-androideabi'
INFO    | Android emulator version 31.3.11.0 (build_id 9058569) (CL:N/A)
emulator: INFO: Found systemPath /android/sdk/system-images/android-24/default/armeabi-v7a/
emulator: INFO: Found systemPath /android/sdk/system-images/android-24/default/armeabi-v7a/
WARNING | Failed to process .ini file /tmp/.android/avd/arm.avd/quickbootChoice.ini for reading.
+ target=arm-linux-androideabi
+ export RUST_BACKTRACE=1
+ export RUSTFLAGS= 
+ echo RUSTFLAGS: ' '
+ uname -a
RUSTFLAGS: ' '
Linux 6e0ad38333d9 6.17.0-29-generic #29-Ubuntu SMP PREEMPT_DYNAMIC Tue May  5 19:42:34 UTC 2026 x86_64 x86_64 x86_64 GNU/Linux
+ cmd=cargo test --target arm-linux-androideabi 
+ test_flags=--skip check_style
+ cmd=cargo test --target arm-linux-androideabi  --manifest-path libc-test/Cargo.toml
+ rustc --print cfg --target arm-linux-androideabi
+ sed -n s/target_env="\(.*\)"/\1/p
+ env=
+ rustc --print cfg --target arm-linux-androideabi
+ sed -n s/target_pointer_width="\(.*\)"/\1/p
+ bits=32
+ cargo test --target arm-linux-androideabi --manifest-path libc-test/Cargo.toml --no-default-features -- --skip check_style
   Compiling libc v1.0.0-alpha.3 (/checkout)
   Compiling askama v0.14.0
error: failed to run custom build command for `libc v1.0.0-alpha.3 (/checkout)`

Caused by:
  process didn't exit successfully: `/checkout/target/debug/build/libc-2510570db3fdeea6/build-script-build` (exit status: 101)
  --- stdout
  cargo:rerun-if-changed=build.rs

  --- stderr

  thread 'main' (67) panicked at build.rs:219:5:
  failed to run rustc: rustc: error while loading shared libraries: libLLVM.so.22.1-rust-1.97.0-nightly: cannot open shared object file: No such file or directory

  stack backtrace:
     0: __rustc::rust_begin_unwind
               at /rustc/b954122bbe6c4a244c511a9a168c6d5438d8f58f/library/std/src/panicking.rs:689:5
     1: core::panicking::panic_fmt
               at /rustc/b954122bbe6c4a244c511a9a168c6d5438d8f58f/library/core/src/panicking.rs:80:14
     2: build_script_build::rustc_version_cmd
               at ./build.rs:219:5
     3: build_script_build::rustc_minor_nightly
               at ./build.rs:240:22
     4: build_script_build::main
               at ./build.rs:66:42
     5: <fn() as core::ops::function::FnOnce<()>>::call_once
               at /rust/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5
  note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
warning: build failed, waiting for other jobs to finish...

[Rawk]

I got the docker test running locally now. The problem was a rust-toolchain.toml file i had laying around i the project.

I will take a closer look at what fails and what works.

[Rawk]

I think it should be ok now. The symbols getnetent, setnetent and endnetent are now cfg-disabled for Android and the Android CI tests succeeds.

The CI fails for unrelated reasons. It failed for the same reason on the daily run.

@rustbot ready

[JohnTitor]

I haven't searched all the platforms but at least the n_aliases can vary, e.g Cygwin has it as short: https://cygwin.com/git/?p=newlib-cygwin.git;a=blob_plain;f=winsup/cygwin/include/netdb.h;hb=HEAD

You could add it for platforms where you're confident to use.

View changes since the review

[Rawk]

I am only confident for Linux. So i moved the struct netent and the related functions into unix/linux_like/linux/mod.rs and checked that the definition is correct for gnu, musl and uclibc.

[JohnTitor]

@Rawk This hasn't been addressed at all.

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[Rawk]

@rustbot ready

[tgross35]

Thank you!

View changes since this review

Author moved from all Unix to only Linux