fix(native): load config before init

- add native remap apk

common/src/main/assets/lang/en_US.json

@@ -627,6 +627,10 @@
                             "disable_bitmoji": {
                                 "name": "Disable Bitmoji",
                                 "description": "Disables Friends Profile Bitmoji"
+                            },
+                            "remap_apk": {
+                                "name": "Remap APK",
+                                "description": "Hides SnapEnhance apk path in /proc/self/maps"
                             }
                         }
                     },

common/src/main/kotlin/me/rhunk/snapenhance/common/config/impl/Experimental.kt

@@ -11,6 +11,7 @@ class Experimental : ConfigContainer() {
 
     class NativeHooks : ConfigContainer(hasGlobalState = true) {
         val disableBitmoji = boolean("disable_bitmoji")
+        val remapApk = boolean("remap_apk") { addNotices(FeatureNotice.UNSTABLE) }
     }
 
     class E2EEConfig : ConfigContainer(hasGlobalState = true) {

core/src/main/kotlin/me/rhunk/snapenhance/core/ModContext.kt

@@ -147,11 +147,16 @@ class ModContext(
         _config.loadFromCallback { file ->
             file.loadFromBridge(bridgeClient)
         }
+        reloadNativeConfig()
+    }
+
+    fun reloadNativeConfig() {
         native.loadNativeConfig(
             NativeConfig(
                 disableBitmoji = config.experimental.nativeHooks.disableBitmoji.get(),
                 disableMetrics = config.global.disableMetrics.get(),
-                hookAssetOpen = config.experimental.disableComposerModules.get().isNotEmpty()
+                hookAssetOpen = config.experimental.disableComposerModules.get().isNotEmpty(),
+                remapApk = config.experimental.nativeHooks.remapApk.get(),
             )
         )
     }

core/src/main/kotlin/me/rhunk/snapenhance/core/SnapEnhance.kt

@@ -190,13 +190,15 @@ class SnapEnhance {
             val libName = param.arg<String>(1)
             if (libName != "client") return@hook
             unhook()
-            appContext.native.initOnce()
-            appContext.native.nativeUnaryCallCallback = { request ->
+            appContext.native.initOnce {
+                nativeUnaryCallCallback = { request ->
                     appContext.event.post(NativeUnaryCallEvent(request.uri, request.buffer)) {
                         request.buffer = buffer
                         request.canceled = canceled
                     }
                 }
+                appContext.reloadNativeConfig()
+            }
         }.also { unhook = { it.unhook() } }
     }
 

native/build.gradle.kts

@@ -24,6 +24,7 @@ android {
             cmake {
                 arguments += listOf(
                     "-DOBFUSCATED_NAME=$nativeName",
+                    "-DBUILD_PACKAGE=${rootProject.ext["applicationId"]}",
                     "-DBUILD_NAMESPACE=${namespace!!.replace(".", "/")}"
                 )
             }

native/jni/CMakeLists.txt

@@ -16,6 +16,7 @@ add_library(${CMAKE_PROJECT_NAME} SHARED
     )
 
 add_compile_definitions(BUILD_NAMESPACE="${BUILD_NAMESPACE}")
+add_compile_definitions(BUILD_PACKAGE="${BUILD_PACKAGE}")
 target_link_libraries(${CMAKE_PROJECT_NAME}
         android
         log

native/jni/src/common.h

@@ -13,6 +13,7 @@ typedef struct {
     bool disable_bitmoji;
     bool disable_metrics;
     bool hook_asset_open;
+    bool remap_apk;
 } native_config_t;
 
 namespace common {

native/jni/src/library.cpp

@@ -15,7 +15,6 @@ void JNICALL init(JNIEnv *env, jobject clazz) {
     LOGD("Initializing native");
     using namespace common;
 
-    native_config = new native_config_t;
     native_lib_object = env->NewGlobalRef(clazz);
     client_module = util::get_module("libclient.so");
 
@@ -32,6 +31,10 @@ void JNICALL init(JNIEnv *env, jobject clazz) {
     SqliteMutexHook::init();
     DuplexHook::init(env);
 
+    if (native_config->remap_apk) {
+        util::remap_sections(BUILD_PACKAGE);
+    }
+
     LOGD("Native initialized");
 }
 
@@ -43,6 +46,7 @@ void JNICALL load_config(JNIEnv *env, jobject _, jobject config_object) {
     native_config->disable_bitmoji = GET_CONFIG_BOOL("disableBitmoji");
     native_config->disable_metrics = GET_CONFIG_BOOL("disableMetrics");
     native_config->hook_asset_open = GET_CONFIG_BOOL("hookAssetOpen");
+    native_config->remap_apk = GET_CONFIG_BOOL("remapApk");
 }
 
 void JNICALL lock_database(JNIEnv *env, jobject _, jstring database_name, jobject runnable) {

native/jni/src/util.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <unistd.h>
+#include <sys/mman.h>
 
 #define HOOK_DEF(ret, func, ...) ret (*func##_original)(__VA_ARGS__); ret func(__VA_ARGS__)
 
@@ -51,7 +52,43 @@ namespace util {
         return { start_offset, end_offset - start_offset };
     }
 
-    uintptr_t find_signature(uintptr_t module_base, uintptr_t size, const std::string &pattern, int offset = 0) {
+    static void remap_sections(const char* path) {
+        char buff[256];
+        auto maps = fopen("/proc/self/maps", "rt");
+
+        while (fgets(buff, sizeof buff, maps) != NULL) {
+            int len = strlen(buff);
+            if (len > 0 && buff[len - 1] == '\n') buff[--len] = '\0';
+            if (strstr(buff, path) == nullptr) continue;
+
+            size_t start, end, offset;
+            char flags[4];
+
+            if (sscanf(buff, "%zx-%zx %c%c%c%c %zx", &start, &end,
+                       &flags[0], &flags[1], &flags[2], &flags[3], &offset) != 7) continue;
+
+            LOGD("Remapping 0x%zx-0x%zx", start, end);
+
+            auto section_size = end - start;
+            auto section_ptr = mmap(0, section_size, PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+            if (section_ptr == MAP_FAILED) {
+                LOGE("mmap failed: %s", strerror(errno));
+                return;
+            }
+
+            memcpy(section_ptr, (void *)start, section_size);
+
+            if (mremap(section_ptr, section_size, section_size, MREMAP_MAYMOVE | MREMAP_FIXED, start) == MAP_FAILED) {
+                LOGE("mremap failed: %s", strerror(errno));
+                return;
+            }
+
+            mprotect((void *)start, section_size, (flags[0] == 'r' ? PROT_READ : 0) | (flags[1] == 'w' ? PROT_WRITE : 0) | (flags[2] == 'x' ? PROT_EXEC : 0));
+        }
+    }
+
+    static uintptr_t find_signature(uintptr_t module_base, uintptr_t size, const std::string &pattern, int offset = 0) {
         std::vector<char> bytes;
         std::vector<char> mask;
         for (size_t i = 0; i < pattern.size(); i += 3) {

native/src/main/kotlin/me/rhunk/snapenhance/nativelib/NativeConfig.kt

@@ -4,4 +4,5 @@ data class NativeConfig(
     val disableBitmoji: Boolean = false,
     val disableMetrics: Boolean = false,
     val hookAssetOpen: Boolean = false,
+    val remapApk: Boolean = false,
 )

native/src/main/kotlin/me/rhunk/snapenhance/nativelib/NativeLib.kt

@@ -11,13 +11,15 @@ class NativeLib {
             private set
     }
 
-    fun initOnce() {
+    fun initOnce(callback: NativeLib.() -> Unit) {
         if (initialized) throw IllegalStateException("NativeLib already initialized")
         runCatching {
             System.loadLibrary(BuildConfig.NATIVE_NAME)
-            init()
             initialized = true
+            callback(this)
+            init()
         }.onFailure {
+            initialized = false
             Log.e("SnapEnhance", "NativeLib init failed")
         }
     }