[core] Refine native api [breaking change] (#522)

* [core] Refine native api [breaking change]

* abi

* mprotect

core/src/main/cpp/main/include/base/object.h

@@ -110,12 +110,12 @@ namespace lspd {
     };
 
     [[gnu::always_inline]]
-    static void *Dlsym(void *handle, const char *name) {
+    inline void *Dlsym(void *handle, const char *name) {
         return dlsym(handle, name);
     }
 
     template<class T, class ... Args>
-    static void *Dlsym(void *handle, T first, Args... last) {
+    inline void *Dlsym(void *handle, T first, Args... last) {
         auto ret = Dlsym(handle, first);
         if (ret) {
             return ret;
@@ -123,9 +123,27 @@ namespace lspd {
         return Dlsym(handle, last...);
     }
 
-    static void HookFunction(void *original, void *replace, void **backup) {
+    inline int HookFunction(void *original, void *replace, void **backup) {
         _make_rwx(original, _page_size);
-        hook_func(original, replace, backup);
+        if constexpr (isDebug) {
+            Dl_info info;
+            dladdr(original, &info);
+            LOGD("Hooking %s (%p) from %s (%p)",
+                 info.dli_sname ? info.dli_sname : "(unknown symbol)", info.dli_saddr,
+                 info.dli_fname ? info.dli_fname : "(unknown file)", info.dli_fbase);
+        }
+        return DobbyHook(original, replace, backup);
+    }
+
+    inline int UnhookFunction(void *original) {
+        if constexpr (isDebug) {
+            Dl_info info;
+            dladdr(original, &info);
+            LOGD("Unhooking %s (%p) from %s (%p)",
+                 info.dli_sname ? info.dli_sname : "(unknown symbol)", info.dli_saddr,
+                 info.dli_fname ? info.dli_fname : "(unknown file)", info.dli_fbase);
+        }
+        return DobbyDestroy(original);
     }
 
     template<class, template<class, class...> class>

core/src/main/cpp/main/src/native_api.cpp

@@ -44,18 +44,22 @@
  */
 
 namespace lspd {
-    std::vector<LsposedNativeOnModuleLoaded> moduleLoadedCallbacks;
+    std::vector<NativeOnModuleLoaded> moduleLoadedCallbacks;
     std::vector<std::string> moduleNativeLibs;
+    std::unique_ptr<void, std::function<void(void *)>> protected_page(
+            mmap(nullptr, _page_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0),
+            [](void *ptr) { munmap(ptr, _page_size); });
 
-    LsposedNativeAPIEntriesV1 init(LsposedNativeOnModuleLoaded onModuleLoaded) {
-        if (onModuleLoaded != nullptr) moduleLoadedCallbacks.push_back(onModuleLoaded);
-
-        LsposedNativeAPIEntriesV1 ret{
-                .version = 1,
-                .inlineHookFunc = HookFunction
+    const auto[entries] = []() {
+        auto *entries = new(protected_page.get()) NativeAPIEntries{
+                .version = 2,
+                .hookFunc = HookFunction,
+                .unhookFunc = UnhookFunction
         };
-        return ret;
-    }
+
+        mprotect(protected_page.get(), _page_size, PROT_READ);
+        return std::make_tuple(entries);
+    }();
 
     void RegisterNativeLib(const std::string &library_name) {
         static bool initialized = []() {
@@ -102,12 +106,17 @@ namespace lspd {
                             break;
                         }
                         auto native_init = reinterpret_cast<NativeInit>(native_init_sym);
-                        native_init(reinterpret_cast<void *>(init));
+                        auto *callback = native_init(entries);
+                        if (callback) {
+                            moduleLoadedCallbacks.push_back(callback);
+                            // return directly to avoid module interaction
+                            return handle;
+                        }
                     }
                 }
 
                 // Callbacks
-                for (LsposedNativeOnModuleLoaded callback: moduleLoadedCallbacks) {
+                for (auto &callback: moduleLoadedCallbacks) {
                     callback(name, handle);
                 }
                 return handle;

core/src/main/cpp/main/src/native_api.h

@@ -29,17 +29,24 @@
 #include <string>
 #include <base/object.h>
 
-// typedef int (*HookFunType)(void *, void *, void **);  // For portability
-typedef void (*LsposedNativeOnModuleLoaded) (const char* name, void* handle);
-typedef void (*NativeInit)(void * init_func);
-struct LsposedNativeAPIEntriesV1 {
+typedef int (*HookFunType)(void *func, void *replace, void **backup);
+
+typedef int (*UnhookFunType)(void *func);
+
+typedef void (*NativeOnModuleLoaded)(const char *name, void *handle);
+
+typedef struct {
     uint32_t version;
-    lspd::HookFunType inlineHookFunc;
-};
+    HookFunType hookFunc;
+    UnhookFunType unhookFunc;
+} NativeAPIEntries;
+
+typedef NativeOnModuleLoaded (*NativeInit)(const NativeAPIEntries *entries);
 
 namespace lspd {
     void InstallNativeAPI();
-    void RegisterNativeLib(const std::string& library_name);
+
+    void RegisterNativeLib(const std::string &library_name);
 }
 
 #endif //LSPOSED_NATIVE_API_H

core/src/main/cpp/main/src/native_hook.cpp

@@ -42,7 +42,6 @@
 #include "art/runtime/gc/scoped_gc_critical_section.h"
 
 namespace lspd {
-
     static volatile bool installed = false;
     static volatile bool art_hooks_installed = false;
 

core/src/main/cpp/main/src/native_hook.h

@@ -19,11 +19,10 @@
  */
 
 #pragma once
+
 #include <dobby.h>
 
 namespace lspd {
-    typedef void (*HookFunType)(void *, void *, void **);
-    static HookFunType hook_func =  reinterpret_cast<HookFunType>(DobbyHook);
     void InstallInlineHooks();
 
 }