Merge pull request #5 from vadage/develop

Merge develop into main

Author: vadage

.github/workflows/build.yml

@@ -10,7 +10,11 @@ on:
 
 jobs:
   build:
-    runs-on: windows-latest
+    strategy:
+      matrix:
+        os: [windows-latest, ubuntu-latest, macos-latest]
+
+    runs-on: ${{ matrix.os }}
 
     steps:
       - name: Checkout code

.github/workflows/release.yml

@@ -6,7 +6,15 @@ on:
 
 jobs:
   build:
-    runs-on: windows-latest
+    strategy:
+      matrix:
+        target: [
+          { os: windows-latest, extension: dll },
+          { os: ubuntu-latest,  extension: so },
+          { os: macos-latest, extension: dylib }
+        ]
+
+    runs-on: ${{ matrix.target.os }}
 
     steps:
       - name: Checkout code
@@ -31,5 +39,5 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
-          file: "target/release/*.dll"
+          file: target/release/*.${{ matrix.target.extension }}
           update_latest_release: true

Cargo.toml

@@ -11,12 +11,12 @@ crate-type = ["cdylib"]
 
 [dependencies]
 jni = "0.21.1"
+libloading = "0.8.1"
 retour = { version = "0.3.1", features = ["static-detour"] }
-winapi = { version = "0.3.9", features = ["libloaderapi"] }
 
 [profile.release]
 panic = "abort"
 codegen-units = 1
 lto = true
 opt-level = 2
-strip = true
+strip = true

README.md

@@ -16,8 +16,11 @@ Keep this in mind as you use this feature in your projects.
 All Java versions should be supported, as `jni` is only used for the structs and no method calls or such.<br>
 Thus far only `Java 8`, `Java 20` and `Java 21` were explicitly tested.
 
-### ⚠️ Operating system
-The build targets only windows, as the library heavily relies on functionality of `winapi`.
+### ✅ Operating system
+The build targets all major architectures
+- Linux
+- Windows
+- MacOS
 
 # How to build
 1. [Install rust](https://www.rust-lang.org/tools/install)

src/class_loader.rs

@@ -1,11 +1,10 @@
-use std::ffi::CString;
 use std::mem;
+use std::os::raw::c_char;
 use std::slice::from_raw_parts_mut;
 
 use retour::static_detour;
 use jni::sys::{jbyte, jclass, JNIEnv, jobject, jsize};
-use winapi::ctypes::c_char;
-use winapi::um::libloaderapi::{GetModuleHandleA, GetProcAddress};
+use libloading::Library;
 
 use crate::jvm::DefineClassCommon;
 
@@ -25,17 +24,12 @@ impl ClassLoader {
     const JAVA_MAGIC_VALUE: [jbyte; 4] = convert_magic_number(0xCAFEBABE);
 
     pub unsafe fn setup_hook() {
-        let module = CString::new("jvm.dll").unwrap();
-        let handle = GetModuleHandleA(module.as_ptr());
-
-        let method_name = CString::new("JVM_DefineClassWithSource").unwrap();
-        let method = GetProcAddress(handle, method_name.as_ptr());
+        let handle = Library::new("jvm").expect("Could not find jvm library.");
+        let method = handle.get::<DefineClassCommon>(b"JVM_DefineClassWithSource").expect("Could not find exported function.");
         let target: DefineClassCommon = mem::transmute(method);
 
-        DefineClassCommonHook.initialize(target, ClassLoader::hooked_define_class_common)
-            .unwrap()
-            .enable()
-            .expect("Unable to hook into class loading.");
+        let hook = DefineClassCommonHook.initialize(target, ClassLoader::hooked_define_class_common).expect("Could not initialize hook for class loading.");
+        hook.enable().expect("Could not to hook into class loading.");
     }
 
     fn hooked_define_class_common(env: JNIEnv, name: *const c_char, loader: jobject, buf: *const jbyte, len: jsize, pd: jobject, source: *const c_char) -> jclass {

src/jvm.rs

@@ -1,4 +1,4 @@
+use std::os::raw::c_char;
 use jni::sys::{JNIEnv, jbyte, jsize, jobject, jclass};
-use winapi::ctypes::c_char;
 
 pub type DefineClassCommon = fn(JNIEnv, *const c_char, jobject, *const jbyte, jsize, jobject, *const c_char) -> jclass;

src/lib.rs

@@ -1,16 +1,13 @@
-use winapi::um::winnt::DLL_PROCESS_ATTACH;
-
 mod class_loader;
 mod jvm;
 
+use std::os::raw::c_void;
+use jni::JavaVM;
+use jni::sys::{jint, JNI_VERSION_1_1};
 use class_loader::ClassLoader;
 
 #[no_mangle]
-pub unsafe extern "stdcall" fn DllMain(_instance: u32, reason: u32, _reserved: *mut u8) -> bool {
-
-    if reason == DLL_PROCESS_ATTACH {
-        ClassLoader::setup_hook();
-    }
-
-    return true;
+pub unsafe extern "system" fn JNI_OnLoad(_: JavaVM, _: *mut c_void) -> jint {
+    ClassLoader::setup_hook();
+    return JNI_VERSION_1_1;
 }