vpnhide/docs/development.md

Development setup

How to build vpnhide from source.

Prerequisites

• JDK 17 or later — what the CI image installs (openjdk-17-jdk-headless); local builds with JDK 21 also work. The lsposed/app Gradle build sets sourceCompatibility = 17 and jvmTarget = "17".
• Android SDK — install platforms;android-35, build-tools;35.0.0, platform-tools (via Android Studio or cmdline-tools). Export ANDROID_HOME.
• Android NDK r27c or later — export ANDROID_NDK_HOME (or drop it in $ANDROID_HOME/ndk/<version>/, the scripts auto-detect). The Gobley Gradle plugin used by lsposed/app reads ANDROID_NDK_ROOT, not ANDROID_NDK_HOME, so export both (or alias one to the other) when invoking Gradle directly.
• Rust (latest stable) with the Android target:

  rustup target add aarch64-linux-android
  cargo install cargo-ndk
  

• podman or docker — only for building the kernel module via DDK images. See kmod/BUILDING.md.
• zip — packaging module zips.
• adb — installing builds on a device.

Gobley (Gradle plugins dev.gobley.cargo + dev.gobley.uniffi) is what builds the Rust crate at lsposed/native/ via cargo-ndk and bundles the resulting libvpnhide_checks.so plus its UniFFI-generated Kotlin bindings (package dev.okhsunrog.vpnhide.checks) into the APK. The plugins are auto-resolved by Gradle from Maven Central — no manual install. Version is pinned in lsposed/gradle/libs.versions.toml.

Repository layout

Path	Component
zygisk/	Zygisk native module (Rust, inline libc hooks)
lsposed/	LSPosed module + target-picker Android app (Kotlin, Compose)
kmod/	Kernel module (C, kretprobes)
portshide/	Localhost port blocker (shell + iptables)
scripts/	Release & changelog tooling
update-json/	Magisk/KSU update metadata
docs/	Contributor documentation (this directory)

Each module has its own README with architecture and design notes.

Signing keystore (required for lsposed)

lsposed/app/build.gradle.kts routes both the debug and release build types through a single signing config that reads lsposed/keystore.properties. Without that file, ./gradlew assembleDebug and :app:assembleRelease fail with:

SigningConfig 'release' is missing required property 'storeFile'

Create lsposed/keystore.properties (git-ignored):

storeFile=/absolute/path/to/your.jks
keyAlias=yourAlias
password=yourPassword

Generate a keystore if you don't have one:

keytool -genkey -v -keystore ~/vpnhide.jks \
    -keyalg RSA -keysize 4096 -validity 36500 -alias vpnhide

Build each module

zygisk module

cd zygisk && ./build-zip.py
# → zygisk/target/vpnhide-zygisk.zip

The script auto-detects the NDK from $ANDROID_NDK_HOME or ~/Android/Sdk/ndk/*.

lsposed APK

cd lsposed && ./gradlew :app:assembleRelease
# → lsposed/app/build/outputs/apk/release/app-release.apk

kernel module

Per-GKI-generation builds via DDK Docker/Podman images. See kmod/BUILDING.md for the full guide (GKI identification, DDK commands, local-source builds with direnv).

Install on device

# APK
adb install -r lsposed/app/build/outputs/apk/release/app-release.apk

# zygisk / kmod: push to device, install via the Magisk or KernelSU manager app
adb push zygisk/target/vpnhide-zygisk.zip /sdcard/Download/
adb push vpnhide-kmod.zip /sdcard/Download/

After flashing kmod or zygisk, reboot the device.

CI lints (run before pushing)

CI runs the same checks. See .github/workflows/ci.yml for the authoritative list.

# Codegen drift — run after editing data/interfaces.toml; CI fails on diff
python3 scripts/codegen-interfaces.py
git diff --quiet  # must be clean

# Rust
cd zygisk && cargo fmt --check && cargo ndk -t arm64-v8a clippy -- -D warnings
cd ../lsposed/native && cargo fmt --check && cargo ndk -t arm64-v8a clippy -- -D warnings
cd ../zygisk && cargo test
cd ../lsposed/native && cargo test

# C (kernel module)
clang-format --dry-run --Werror kmod/vpnhide_kmod.c
# Host-side test of the generated VPN-iface matcher used by the kernel module
gcc -O2 -Wall -Werror -o /tmp/test_iface_lists kmod/test_iface_lists.c && /tmp/test_iface_lists

# Kotlin
ktlint "lsposed/**/*.kt"
cd lsposed && ./gradlew --no-daemon :app:lint
cd lsposed && ./gradlew --no-daemon :app:testDebugUnitTest

Build versions

Every module zip and the APK carry a version string derived from git at build time:

• on a release tag vX.Y.Z → X.Y.Z
• otherwise → X.Y.Z-N-gSHA (commits since the nearest tag + short hash, plus -dirty if the working tree has uncommitted changes)

So a locally-built dev APK shows up in Android Settings as e.g. 0.6.1-5-gabc1234-dirty, and the same string lands in module.prop inside the zip. The committed module.prop files themselves stay at the last release number — the version is stamped into a staging copy per build.

See releasing.md for details.

More docs

• releasing.md — version bump, tag, release flow
• changelog.md — how changelog entries flow from JSON → markdown
• kmod/BUILDING.md — kernel-module build deep dive