From 18fec7b8b4c86155735cfc4ad14e14c674ec89b6 Mon Sep 17 00:00:00 2001
From: whs31 <40-ryazancev_dl@users.noreply.gitlab.radar076.ru>
Date: Tue, 28 May 2024 02:18:10 +0300
Subject: [PATCH] Self-viewing library handle

---
 examples/read_process_memory.cc           | 10 +++++-----
 include/winapi20/impl/libloaderapi_impl.h |  5 +----
 src/impl/libloaderapi_impl.cc             | 19 ++++++++++++++++---
 tests/test_libloaderapi.cc                |  8 ++++++++
 4 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/examples/read_process_memory.cc b/examples/read_process_memory.cc
index e7fea77..03bd3e4 100644
--- a/examples/read_process_memory.cc
+++ b/examples/read_process_memory.cc
@@ -20,11 +20,11 @@ auto main() -> int
   // get vector of all modules
   auto modules = module_snapshot.modules();
   // exclude all non-game modules (not containing "dota 2 beta" in path)
-  modules.erase(std::remove_if(
-      modules.begin(),
-      modules.end(),
-      [](auto& m) { return m.path.string().find("dota 2 beta") == std::string::npos; }), modules.end()
-  );
+//  modules.erase(std::remove_if(
+//      modules.begin(),
+//      modules.end(),
+//      [](auto& m) { return m.path.string().find("dota 2 beta") == std::string::npos; }), modules.end()
+//  );
   fmt::print("listing game modules:\n");
   fmt::print("\t{}", fmt::join(modules, "\n\t"));
 
diff --git a/include/winapi20/impl/libloaderapi_impl.h b/include/winapi20/impl/libloaderapi_impl.h
index 19c6517..dfbec2a 100644
--- a/include/winapi20/impl/libloaderapi_impl.h
+++ b/include/winapi20/impl/libloaderapi_impl.h
@@ -33,10 +33,7 @@ namespace winapi::dll
         WeakReference = 0x00000002
       };
 
-      WINAPI20_EXPORT explicit Library(
-          std::string name,
-          HandleFlags flags = HandleFlags::None
-      ) noexcept(false);
+      WINAPI20_EXPORT explicit Library(OwnershipMode mode, HandleFlags flags = HandleFlags::None) noexcept(false);
       
       WINAPI20_EXPORT explicit Library(
           OwnershipMode mode,
diff --git a/src/impl/libloaderapi_impl.cc b/src/impl/libloaderapi_impl.cc
index 54242a3..cf635dd 100644
--- a/src/impl/libloaderapi_impl.cc
+++ b/src/impl/libloaderapi_impl.cc
@@ -13,6 +13,14 @@ using std::optional;
 using std::nullopt;
 using std::string_view;
 
+namespace {
+  [[nodiscard]] auto current_module_handle() -> HMODULE {
+    auto h = HMODULE();
+    ::GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT, reinterpret_cast<LPCSTR>(current_module_handle), &h);
+    return h;
+  }
+}
+
 namespace winapi::dll
 {
   Library::~Library() {
@@ -20,10 +28,15 @@ namespace winapi::dll
       ::FreeLibrary(this->handle().as<HMODULE>());
   }
 
-  Library::Library(std::string name, Library::HandleFlags flags) noexcept(false)
+  Library::Library(OwnershipMode mode, Library::HandleFlags flags) noexcept(false)
+    : m_pid(PID::current())
+    , m_cleanup(mode == OwnershipMode::Own)
   {
-    // get this library handle
-
+    if(auto const h = ::current_module_handle(); h == nullptr)
+      throw windows_exception("failed to get current module handle");
+    else
+      this->m_handle = Handle(h, Cleanup::Manual);
+    this->m_name = this->file_path().filename().string();
   }
 
   Library::Library(std::string name, Handle&& handle, PID pid, bool cleanup)
diff --git a/tests/test_libloaderapi.cc b/tests/test_libloaderapi.cc
index 4902b90..70cc934 100644
--- a/tests/test_libloaderapi.cc
+++ b/tests/test_libloaderapi.cc
@@ -36,4 +36,12 @@ TEST(Library, View)
   auto ntdll = dll::Library(dll::Library::View, "ntdll.dll", PID::current());
   auto ntdll_fn = ntdll["NtProtectVirtualMemory"];
   EXPECT_TRUE(ntdll_fn.has_value());
+}
+
+TEST(Library, Self)
+{
+  auto lib = dll::Library(dll::Library::View);
+
+  EXPECT_EQ(lib.file_path().filename().string(), "libwinapi20.dll");
+  fmt::print("{}\n", lib.file_path().string());
 }
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