From f9b95b6e137019ce6c2610d63809cbc29c779151 Mon Sep 17 00:00:00 2001
From: stasoid <stasoid@yahoo.com>
Date: Fri, 29 Nov 2024 23:03:56 +0500
Subject: [PATCH] LibIPC: Port MessageBuffer to Windows

---
 Libraries/LibIPC/CMakeLists.txt     |  9 +++--
 Libraries/LibIPC/Connection.h       |  2 +-
 Libraries/LibIPC/Message.h          |  9 +++--
 Libraries/LibIPC/MessageWindows.cpp | 51 +++++++++++++++++++++++++++++
 4 files changed, 64 insertions(+), 7 deletions(-)
 create mode 100644 Libraries/LibIPC/MessageWindows.cpp

diff --git a/Libraries/LibIPC/CMakeLists.txt b/Libraries/LibIPC/CMakeLists.txt
index f2089fd82e0de..cd8e259a71de4 100644
--- a/Libraries/LibIPC/CMakeLists.txt
+++ b/Libraries/LibIPC/CMakeLists.txt
@@ -3,13 +3,16 @@ set(SOURCES
     Decoder.cpp
     Encoder.cpp
     File.cpp
-    Message.cpp
 )
 
 if (UNIX)
-    list(APPEND SOURCES TransportSocket.cpp)
+    list(APPEND SOURCES
+        Message.cpp
+        TransportSocket.cpp)
 else()
-    list(APPEND SOURCES TransportSocketWindows.cpp)
+    list(APPEND SOURCES
+        MessageWindows.cpp
+        TransportSocketWindows.cpp)
 endif()
 
 serenity_lib(LibIPC ipc)
diff --git a/Libraries/LibIPC/Connection.h b/Libraries/LibIPC/Connection.h
index 229227c7c1421..9bbf65b0c3074 100644
--- a/Libraries/LibIPC/Connection.h
+++ b/Libraries/LibIPC/Connection.h
@@ -57,7 +57,7 @@ class ConnectionBase : public Core::EventReceiver {
     RefPtr<Core::Timer> m_responsiveness_timer;
 
     Vector<NonnullOwnPtr<Message>> m_unprocessed_messages;
-    Queue<IPC::File> m_unprocessed_fds;
+    Queue<IPC::File> m_unprocessed_fds; // unused on Windows
     ByteBuffer m_unprocessed_bytes;
 
     u32 m_local_endpoint_magic { 0 };
diff --git a/Libraries/LibIPC/Message.h b/Libraries/LibIPC/Message.h
index 413cb03dde988..c0b9b39291706 100644
--- a/Libraries/LibIPC/Message.h
+++ b/Libraries/LibIPC/Message.h
@@ -12,8 +12,8 @@
 #include <AK/RefPtr.h>
 #include <AK/Vector.h>
 #include <LibCore/Forward.h>
+#include <LibCore/System.h>
 #include <LibIPC/Transport.h>
-#include <unistd.h>
 
 namespace IPC {
 
@@ -27,7 +27,7 @@ class AutoCloseFileDescriptor : public RefCounted<AutoCloseFileDescriptor> {
     ~AutoCloseFileDescriptor()
     {
         if (m_fd != -1)
-            close(m_fd);
+            (void)Core::System::close(m_fd);
     }
 
     int value() const { return m_fd; }
@@ -45,11 +45,14 @@ class MessageBuffer {
 
     ErrorOr<void> append_file_descriptor(int fd);
 
-    ErrorOr<void> transfer_message(Transport& socket);
+    ErrorOr<void> transfer_message(Transport& transport);
 
 private:
     Vector<u8, 1024> m_data;
     Vector<NonnullRefPtr<AutoCloseFileDescriptor>, 1> m_fds;
+#ifdef AK_OS_WINDOWS
+    Vector<size_t> m_handle_offsets;
+#endif
 };
 
 enum class ErrorCode : u32 {
diff --git a/Libraries/LibIPC/MessageWindows.cpp b/Libraries/LibIPC/MessageWindows.cpp
new file mode 100644
index 0000000000000..4a3ee6a73beec
--- /dev/null
+++ b/Libraries/LibIPC/MessageWindows.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2024, Tim Flynn <trflynn89@serenityos.org>
+ * Copyright (c) 2024, stasoid <stasoid@yahoo.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibIPC/Message.h>
+#include <io.h>
+
+namespace IPC {
+
+using MessageSizeType = u32;
+
+MessageBuffer::MessageBuffer()
+{
+    m_data.resize(sizeof(MessageSizeType));
+}
+
+ErrorOr<void> MessageBuffer::extend_data_capacity(size_t capacity)
+{
+    TRY(m_data.try_ensure_capacity(m_data.size() + capacity));
+    return {};
+}
+
+ErrorOr<void> MessageBuffer::append_data(u8 const* values, size_t count)
+{
+    TRY(m_data.try_append(values, count));
+    return {};
+}
+
+ErrorOr<void> MessageBuffer::append_file_descriptor(int fd)
+{
+    m_fds.append(adopt_ref(*new AutoCloseFileDescriptor(fd)));
+    m_handle_offsets.append(m_data.size());
+    intptr_t handle = _get_osfhandle(fd);
+    m_data.append((u8*)&handle, sizeof(handle));
+    return {};
+}
+
+ErrorOr<void> MessageBuffer::transfer_message(Transport& transport)
+{
+    VERIFY(m_data.size() >= sizeof(MessageSizeType) && m_data.size() < NumericLimits<MessageSizeType>::max());
+    size_t message_size = m_data.size() - sizeof(MessageSizeType);
+    *(MessageSizeType*)m_data.data() = message_size;
+
+    TRY(transport.transfer(m_data.span(), m_handle_offsets));
+    return {};
+}
+
+}