LibCore: Implement System::set_close_on_exec

Author: https://github.com/stasoid
Commit: https://github.com/LadybirdBrowser/ladybird/commit/2abc7929387
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3002
Reviewed-by: https://github.com/ADKaster ✅
Reviewed-by: https://github.com/AtkinsSJ

Libraries/LibCore/Socket.cpp

@@ -193,15 +193,7 @@ ErrorOr<void> PosixSocketHelper::set_blocking(bool enabled)
 
 ErrorOr<void> PosixSocketHelper::set_close_on_exec(bool enabled)
 {
-    int flags = TRY(System::fcntl(m_fd, F_GETFD));
-
-    if (enabled)
-        flags |= FD_CLOEXEC;
-    else
-        flags &= ~FD_CLOEXEC;
-
-    TRY(System::fcntl(m_fd, F_SETFD, flags));
-    return {};
+    return System::set_close_on_exec(m_fd, enabled);
 }
 
 ErrorOr<void> PosixSocketHelper::set_receive_timeout(AK::Duration timeout)

Libraries/LibCore/SocketWindows.cpp

@@ -106,9 +106,7 @@ ErrorOr<void> PosixSocketHelper::set_blocking(bool)
 
 ErrorOr<void> PosixSocketHelper::set_close_on_exec(bool enabled)
 {
-    if (!SetHandleInformation(to_handle(m_fd), HANDLE_FLAG_INHERIT, enabled ? 0 : HANDLE_FLAG_INHERIT))
-        return Error::from_windows_error();
-    return {};
+    return System::set_close_on_exec(m_fd, enabled);
 }
 
 ErrorOr<size_t> PosixSocketHelper::pending_bytes() const

Libraries/LibCore/System.cpp

@@ -1017,4 +1017,17 @@ ErrorOr<void> sleep_ms(u32 milliseconds)
     return {};
 }
 
+ErrorOr<void> set_close_on_exec(int fd, bool enabled)
+{
+    int flags = TRY(fcntl(fd, F_GETFD));
+
+    if (enabled)
+        flags |= FD_CLOEXEC;
+    else
+        flags &= ~FD_CLOEXEC;
+
+    TRY(fcntl(fd, F_SETFD, flags));
+    return {};
+}
+
 }

Libraries/LibCore/System.h

@@ -184,5 +184,6 @@ ErrorOr<void> set_resource_limits(int resource, rlim_t limit);
 int getpid();
 bool is_socket(int fd);
 ErrorOr<void> sleep_ms(u32 milliseconds);
+ErrorOr<void> set_close_on_exec(int fd, bool enabled);
 
 }

Libraries/LibCore/SystemWindows.cpp

@@ -269,4 +269,11 @@ ErrorOr<ByteString> current_executable_path()
     return TRY(Process::get_name()).to_byte_string();
 }
 
+ErrorOr<void> set_close_on_exec(int handle, bool enabled)
+{
+    if (!SetHandleInformation(to_handle(handle), HANDLE_FLAG_INHERIT, enabled ? 0 : HANDLE_FLAG_INHERIT))
+        return Error::from_windows_error();
+    return {};
+}
+
 }

Libraries/LibIPC/File.cpp

@@ -11,25 +11,11 @@
 
 namespace IPC {
 
-// FIXME: IPC::Files transferred over the wire are always set O_CLOEXEC during decoding.
-//        Perhaps we should add an option to IPC::File to allow the receiver to decide whether to
-//        make it O_CLOEXEC or not. Or an attribute in the .ipc file?
-ErrorOr<void> File::clear_close_on_exec()
-{
-    auto fd_flags = TRY(Core::System::fcntl(m_fd, F_GETFD));
-    fd_flags &= ~FD_CLOEXEC;
-    TRY(Core::System::fcntl(m_fd, F_SETFD, fd_flags));
-    return {};
-}
-
 template<>
 ErrorOr<File> decode(Decoder& decoder)
 {
     auto file = TRY(decoder.files().try_dequeue());
-    auto fd = file.fd();
-
-    auto fd_flags = TRY(Core::System::fcntl(fd, F_GETFD));
-    TRY(Core::System::fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC));
+    TRY(Core::System::set_close_on_exec(file.fd(), true));
     return file;
 }
 

Libraries/LibIPC/File.h

@@ -63,7 +63,13 @@ public:
         return exchange(m_fd, -1);
     }
 
-    ErrorOr<void> clear_close_on_exec();
+    // FIXME: IPC::Files transferred over the wire are always set O_CLOEXEC during decoding.
+    //        Perhaps we should add an option to IPC::File to allow the receiver to decide whether to
+    //        make it O_CLOEXEC or not. Or an attribute in the .ipc file?
+    ErrorOr<void> clear_close_on_exec()
+    {
+        return Core::System::set_close_on_exec(m_fd, false);
+    }
 
 private:
     explicit File(int fd)

Libraries/LibIPC/FileWindows.cpp

@@ -12,13 +12,6 @@
 
 namespace IPC {
 
-ErrorOr<void> File::clear_close_on_exec()
-{
-    if (!SetHandleInformation(to_handle(m_fd), HANDLE_FLAG_INHERIT, HANDLE_FLAG_INHERIT))
-        return Error::from_windows_error();
-    return {};
-}
-
 template<>
 ErrorOr<File> decode(Decoder& decoder)
 {