libarchive base extraction + external JNI libraries

CMakeLists.txt

@@ -0,0 +1,33 @@
+cmake_minimum_required(VERSION 3.16.3)
+project(android-luajit-launcher LANGUAGES C CXX)
+
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(LuaJIT luajit REQUIRED IMPORTED_TARGET)
+pkg_check_modules(libarchive libarchive REQUIRED IMPORTED_TARGET)
+
+set(THREADS_PREFER_PTHREAD_FLAG TRUE)
+find_package(Threads REQUIRED)
+if(NOT Threads_FOUND OR NOT CMAKE_USE_PTHREADS_INIT)
+    message(FATAL_ERROR "pthread library not found!")
+endif()
+
+add_library(7z)
+set_target_properties(7z PROPERTIES CXX_VISIBILITY_PRESET hidden)
+set_target_properties(7z PROPERTIES VISIBILITY_INLINES_HIDDEN TRUE)
+target_link_libraries(7z PRIVATE PkgConfig::libarchive android log)
+target_sources(7z PRIVATE jni/unarchive.cpp)
+
+add_library(ioctl SHARED)
+set_target_properties(ioctl PROPERTIES CXX_VISIBILITY_PRESET hidden)
+set_target_properties(ioctl PROPERTIES VISIBILITY_INLINES_HIDDEN TRUE)
+target_sources(ioctl PRIVATE jni/ioctl/ioctl.cpp)
+
+add_library(luajit-launcher SHARED)
+set_target_properties(luajit-launcher PROPERTIES C_VISIBILITY_PRESET hidden)
+target_include_directories(luajit-launcher PUBLIC jni/android_native_app_glue)
+target_link_libraries(luajit-launcher PRIVATE PkgConfig::LuaJIT Threads::Threads android log)
+target_sources(luajit-launcher PRIVATE jni/android_native_app_glue/android_native_app_glue.c jni/jni_helper.c jni/main.c)
+
+install(TARGETS 7z)
+install(TARGETS ioctl)
+install(TARGETS luajit-launcher)

app/build.gradle

@@ -19,6 +19,8 @@ android {
         buildConfigField "String", "APP_NAME", '"' + projectName + '"'
         buildConfigField "boolean", "IN_APP_UPDATES", "false"
         buildConfigField "boolean", "SUPPORTS_RUNTIME_CHANGES", "false"
+
+        buildConfigField "String", "SEVENZIP_LIB", '"' + sevenZipLib + '"'
     }
 
     sourceSets {
@@ -32,10 +34,12 @@ android {
         includeInApk = false
     }
 
-    externalNativeBuild {
-        ndkBuild {
-            path file('../jni/Android.mk')
-        }
+    if (buildJni.toBoolean()) {
+	externalNativeBuild {
+	    ndkBuild {
+		path file('../jni/Android.mk')
+	    }
+	}
     }
 
     buildFeatures {

app/src/main/java/org/koreader/launcher/Assets.kt

@@ -17,8 +17,8 @@ class Assets {
     private val tag = this::class.java.simpleName
 
     init {
-        Log.i(tag, "loading lib7z")
-        System.loadLibrary("7z")
+        Log.i(tag, "loading ${BuildConfig.SEVENZIP_LIB}")
+        System.loadLibrary(BuildConfig.SEVENZIP_LIB)
     }
 
     fun extract(activity: Activity): Boolean {

gradle.properties

@@ -16,6 +16,10 @@ ndkCustomPath=.
 assetsPath=../assets
 libsPath=../libs
 
+# JNI libraries
+buildJni=true
+sevenZipLib=z
+
 # Compilation features
 android.defaults.buildfeatures.aidl=false
 android.defaults.buildfeatures.buildconfig=true

jni/android_native_app_glue/android_native_app_glue.c

@@ -175,9 +175,6 @@ void android_app_post_exec_cmd(struct android_app* android_app, int8_t cmd) {
     }
 }
 
-void app_dummy() {
-}
-
 static void android_app_destroy(struct android_app* android_app) {
     LOGD("android_app_destroy!");
     free_saved_state(android_app);

jni/android_native_app_glue/android_native_app_glue.h

@@ -309,6 +309,8 @@ enum {
     APP_CMD_DESTROY,
 };
 
+_Pragma("GCC visibility push(default)")
+
 /**
  * Call when ALooper_pollAll() returns LOOPER_ID_MAIN, reading the next
  * app command message.
@@ -329,21 +331,13 @@ void android_app_pre_exec_cmd(struct android_app* android_app, int8_t cmd);
  */
 void android_app_post_exec_cmd(struct android_app* android_app, int8_t cmd);
 
-/**
- * Dummy function that used to be used to prevent the linker from stripping app
- * glue code. No longer necessary, since __attribute__((visibility("default")))
- * does this for us.
- */
-__attribute__((
-    deprecated("Calls to app_dummy are no longer necessary. See "
-               "https://github.com/android-ndk/ndk/issues/381."))) void
-app_dummy();
-
 /**
  * This is the function that application code must implement, representing
  * the main entry to the app.
  */
-extern void android_main(struct android_app* app);
+void android_main(struct android_app* app);
+
+_Pragma("GCC visibility pop")
 
 #ifdef __cplusplus
 }

jni/unarchive.cpp

@@ -0,0 +1,96 @@
+extern "C" {
+
+#include <limits.h>
+#include <stdlib.h>
+
+#include <android/asset_manager_jni.h>
+#include <android/log.h>
+#include <jni.h>
+
+#include <archive.h>
+#include <archive_entry.h>
+
+#define LOGE(...) ((void)__android_log_print(ANDROID_LOG_ERROR, "unarchive", __VA_ARGS__))
+
+
+static int extract_asset(struct AAssetManager *mgr, const char *name, const char *destination)
+{
+    struct archive *in = NULL, *out = NULL;
+    int r = ARCHIVE_FAILED;
+    AAsset *asset = NULL;
+    char path[PATH_MAX];
+
+    asset = AAssetManager_open(mgr, name, AASSET_MODE_UNKNOWN);
+    if (!asset)
+        goto end;
+
+    in = archive_read_new();
+    archive_read_support_format_all(in);
+    archive_read_support_filter_all(in);
+
+    out = archive_write_disk_new();
+    archive_write_disk_set_options(out, ARCHIVE_EXTRACT_SECURE_NODOTDOT);
+
+    if ((r = archive_read_open_memory(in, AAsset_getBuffer(asset), AAsset_getLength64(asset)))) {
+        LOGE("%s", archive_error_string(in));
+        goto end;
+    }
+
+    for (struct archive_entry *entry; ; ) {
+        r = archive_read_next_header(in, &entry);
+        if (r == ARCHIVE_EOF)
+            goto end;
+        if (r < ARCHIVE_OK)
+            LOGE("%s", archive_error_string(in));
+        if (r < ARCHIVE_WARN)
+            goto end;
+        if (snprintf(path, sizeof (path), "%s/%s", destination, archive_entry_pathname(entry)) >= sizeof (path)) {
+            LOGE("path to long %s", archive_entry_pathname(entry));
+            r = ARCHIVE_FAILED;
+            goto end;
+        }
+        archive_entry_set_pathname(entry, path);
+        r = archive_read_extract2(in, entry, out);
+        if (r < ARCHIVE_OK)
+            LOGE("%s", archive_error_string(out));
+        if (r < ARCHIVE_WARN)
+            goto end;
+    }
+
+end:
+    if (in) {
+        archive_read_close(in);
+        archive_read_free(in);
+    }
+
+    if (out) {
+        archive_write_close(out);
+        archive_write_free(out);
+    }
+
+    if (asset) {
+        AAsset_close(asset);
+    }
+
+    return r;
+}
+
+JNIEXPORT jint JNICALL
+Java_org_koreader_launcher_Assets_extract(JNIEnv *env,
+                                          __unused jobject obj,
+                                          jobject assetsManager,
+                                          jstring payload,
+                                          jstring output)
+{
+    const char *name = env->GetStringUTFChars(payload, nullptr);
+    const char *destination = env->GetStringUTFChars(output, nullptr);
+
+    int r = extract_asset(AAssetManager_fromJava(env, assetsManager), name, destination);
+
+    env->ReleaseStringUTFChars(payload, name);
+    env->ReleaseStringUTFChars(output, destination);
+
+    return r != ARCHIVE_OK && r != ARCHIVE_EOF;
+}
+
+}