add attach mode to script

.github/workflows/ci.yml

@@ -18,9 +18,12 @@ jobs:
       - name: Build project
         run: ./_build.sh
 
-      - name: Run project
+      - name: Run project without root
         run: ./_run.sh
 
+      - name: Run project with root
+        run: ./_run.sh -a
+
   windows-build:
     runs-on: windows-latest
 

Bootstrapper/CMakeLists.txt

@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.20)
 project(Bootstrapper)
 
-set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD 23)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 add_library(${PROJECT_NAME} SHARED src/library.cpp)

Bootstrapper/src/library.cpp

@@ -4,7 +4,7 @@
 #else
 #define EXPORT __attribute__((visibility("default")))
 #include <dlfcn.h>
-#include <cstdio>
+#include <thread>
 #endif
 
 /// This class helps to manage shared libraries
@@ -113,3 +113,32 @@ extern "C" EXPORT InitializeResult bootstrapper_load_assembly(
 
     return InitializeResult::Success;
 }
+
+#ifndef _WIN32
+std::string getEnvVar(const char *name) {
+    auto val = std::getenv(name);
+    return val == nullptr ? std::string() : std::string(val);
+}
+
+__attribute__((constructor))
+void initialize_library() {
+    auto runtime_config_path = getEnvVar("RUNTIME_CONFIG_PATH");
+    auto assembly_path = getEnvVar("ASSEMBLY_PATH");
+    auto type_name = getEnvVar("TYPE_NAME");
+    auto method_name = getEnvVar("METHOD_NAME");
+
+    if (!runtime_config_path.empty() && !assembly_path.empty() && !type_name.empty() && !method_name.empty()) {
+        std::thread thread([=] {
+            sleep(1);
+            auto ret = bootstrapper_load_assembly(
+                runtime_config_path.c_str(),
+                assembly_path.c_str(),
+                type_name.c_str(),
+                method_name.c_str()
+            );
+            printf("[+] api.inject() => %d\n", (uint32_t) ret);
+        });
+        thread.detach();
+    }
+}
+#endif

README.md

@@ -34,6 +34,11 @@ It will build
 This script should produce output like the GIF above
 
 - `_run.sh` on Linux
+
+  > [!NOTE]
+  > If you want to attach to an existing process on Linux, this requires root privileges. In this case, use
+  `_run.sh -a` (attach).
+
 - `_run.bat` on Windows
 
 ### Internal documentation

_run.bat

@@ -4,4 +4,5 @@ DemoApplication.exe ^
 Bootstrapper\build\Release\Bootstrapper.dll ^
 RuntimePatcher\dist\RuntimePatcher.runtimeconfig.json ^
 RuntimePatcher\dist\RuntimePatcher.dll ^
-"RuntimePatcher.Main, RuntimePatcher" "InitializePatches"
+"RuntimePatcher.Main, RuntimePatcher" ^
+"InitializePatches"

_run.sh

@@ -1,11 +1,35 @@
 #!/usr/bin/env bash
-set -ex
+set -e
 
-sudo sysctl kernel.yama.ptrace_scope=0
-./DemoApplication/dist/DemoApplication &
-npm start -- inject \
-DemoApplication \
-Bootstrapper/build/libBootstrapper.so \
-RuntimePatcher/dist/RuntimePatcher.runtimeconfig.json \
-RuntimePatcher/dist/RuntimePatcher.dll \
-"RuntimePatcher.Main, RuntimePatcher" "InitializePatches"
+while getopts "a" OPTION 2> /dev/null; do
+  case ${OPTION} in
+    a)
+      DO_ATTACH="yes"
+      ;;
+    \?)
+      break
+      ;;
+  esac
+done
+
+if [ "$DO_ATTACH" == "yes" ]; then
+  set -m
+  sudo sysctl kernel.yama.ptrace_scope=0
+
+  ./DemoApplication/dist/DemoApplication &
+  npm start -- inject \
+  DemoApplication \
+  Bootstrapper/build/libBootstrapper.so \
+  RuntimePatcher/dist/RuntimePatcher.runtimeconfig.json \
+  RuntimePatcher/dist/RuntimePatcher.dll \
+  "RuntimePatcher.Main, RuntimePatcher" \
+  "InitializePatches"
+  fg %1
+else
+  LD_PRELOAD=./Bootstrapper/build/libBootstrapper.so \
+  RUNTIME_CONFIG_PATH="$(pwd)/RuntimePatcher/dist/RuntimePatcher.runtimeconfig.json" \
+  ASSEMBLY_PATH="$(pwd)/RuntimePatcher/dist/RuntimePatcher.dll" \
+  TYPE_NAME="RuntimePatcher.Main, RuntimePatcher" \
+  METHOD_NAME="InitializePatches" \
+  ./DemoApplication/dist/DemoApplication
+fi