feat(loader): check for wsc service before starting

defendnot-loader/util/scm.hpp

@@ -0,0 +1,113 @@
+#pragma once
+#include <array>
+#include <memory>
+#include <optional>
+#include <string_view>
+#include <Windows.h>
+
+namespace scm {
+    using SCHandleRaw = SC_HANDLE;
+    using SCHandle = std::unique_ptr<std::remove_pointer_t<SCHandleRaw>, decltype(&CloseServiceHandle)>;
+
+    inline SCHandle make_sc_handle(SCHandleRaw handle) {
+        return SCHandle(handle, CloseServiceHandle);
+    }
+
+    enum class ServiceState : std::uint8_t {
+        UNKNOWN = 0,
+        STOPPED,
+        STOP_PENDING,
+        START_PENDIND,
+        RUNNING,
+        PAUSED,
+        PAUSE_PENDING,
+        CONTINUE_PENDING,
+    };
+    /// \note @es3n1n: we should use magic_enum once we have more than one enum where we need to get value name
+    constexpr auto kServiceStateNames =
+        std::to_array<std::string_view>({"UNKNOWN", "STOPPED", "STOP_PENDING", "START_PENDING", "RUNNING", "PAUSED", "PAUSE_PENDING", "CONTINUE_PENDING"});
+
+    class Service {
+    public:
+        Service(SCHandleRaw handle): handle_(make_sc_handle(handle)) { };
+        ~Service() = default;
+
+    public:
+        bool query_status() noexcept {
+            if (status_process_.has_value()) {
+                return true;
+            }
+
+            SERVICE_STATUS_PROCESS status;
+            DWORD needed = 0;
+            if (!QueryServiceStatusEx(handle_.get(), SC_STATUS_PROCESS_INFO, reinterpret_cast<PBYTE>(&status), sizeof(status), &needed)) {
+                return false;
+            }
+
+            status_process_ = status;
+            return true;
+        }
+
+        [[nodiscard]] ServiceState state() noexcept {
+            if (!query_status() || !status_process_.has_value()) {
+                return ServiceState::UNKNOWN;
+            }
+
+            switch (status_process_->dwCurrentState) {
+            case SERVICE_STOPPED:
+                return ServiceState::STOPPED;
+            case SERVICE_STOP_PENDING:
+                return ServiceState::STOP_PENDING;
+            case SERVICE_START_PENDING:
+                return ServiceState::START_PENDIND;
+            case SERVICE_RUNNING:
+                return ServiceState::RUNNING;
+            case SERVICE_PAUSED:
+                return ServiceState::PAUSED;
+            case SERVICE_PAUSE_PENDING:
+                return ServiceState::PAUSE_PENDING;
+            case SERVICE_CONTINUE_PENDING:
+                return ServiceState::CONTINUE_PENDING;
+            default:
+                return ServiceState::UNKNOWN;
+            }
+        }
+
+        [[nodiscard]] bool valid() const noexcept {
+            return handle_.get() != nullptr;
+        }
+
+        [[nodiscard]] explicit operator bool() const noexcept {
+            return valid();
+        }
+
+    private:
+        std::optional<SERVICE_STATUS_PROCESS> status_process_ = std::nullopt;
+        SCHandle handle_;
+    };
+
+    class Manager {
+        constexpr static auto kDesiredPermissions = GENERIC_READ;
+
+    public:
+        Manager(): handle_(make_sc_handle(OpenSCManagerW(nullptr, nullptr, kDesiredPermissions))) { };
+        ~Manager() = default;
+
+    public:
+        [[nodiscard]] Service get_service(const std::wstring_view service_name) noexcept {
+            return Service(OpenServiceW(handle_.get(), service_name.data(), kDesiredPermissions));
+        }
+
+    public:
+        [[nodiscard]] bool valid() const noexcept {
+            return handle_.get() != nullptr;
+        }
+
+        [[nodiscard]] explicit operator bool() const noexcept {
+            return valid();
+        }
+
+    private:
+        SCHandle handle_;
+    };
+} // namespace scm