File system endpoints

Support

Support for KasperskyOS

KasperskyOS Community Edition

Developing security policies

Methods of KasperskyOS core endpoints

File system endpoints

August 2, 2023

ID kernel_methods_fs

Get as PDF

These endpoints are intended for working with the ROMFS file system used by the KasperskyOS kernel.

Information about methods of endpoints is provided in the tables below.

Methods of the fs.FS endpoint (kl.core.FS interface)

Method	Method purpose and parameters	Potential danger of the method
`Open`	Purpose Opens a file. Parameters [in] `name` – name of the file. [out] `handle` – value whose binary representation consists of multiple fields, including a handle field and a handle permissions mask field. The handle identifies the opened file. [out] `rc` – return code.	Allows the kernel memory to be used up by creating a multitude of objects within it.
`Close`	Purpose Closes a file. Parameters [in] `handle` – value whose binary representation consists of multiple fields, including a handle field and a handle permissions mask field. The handle identifies the opened file. [out] `rc` – return code.	N/A
`Read`	Purpose Reads data from a file. Parameters [in] `handle` – value whose binary representation consists of multiple fields, including a handle field and a handle permissions mask field. The handle identifies the opened file. [in] `sectorNumber` – data block number. Enumeration starts with zero. [out] `read` – size of the read data in bytes. [out] `data` – sequence containing the read data. [out] `rc` – return code.	N/A
`GetSize`	Purpose Lets you get the size of a file. Parameters [in] `handle` – value whose binary representation consists of multiple fields, including a handle field and a handle permissions mask field. The handle identifies the opened file. [out] `size` – file size in bytes. [out] `rc` – return code.	N/A
`GetId`	Purpose Lets you get the unique ID of a file. Parameters [in] `handle` – value whose binary representation consists of multiple fields, including a handle field and a handle permissions mask field. The handle identifies the opened file. [out] `id` – unique ID of the file. [out] `rc` – return code.	N/A
`Count`	Purpose Lets you get the number of files in the file system. Parameters [out] `count` – number of files in the file system. [out] `rc` – return code.	N/A
`GetInfo`	Purpose Lets you get the name and unique ID of a file based on the file index. Parameters [in] `index` – file index. Enumeration starts with zero. [in] `nameLenMax` – buffer size for saving the file name. [out] `name` – name of the file. [out] `id` – unique ID of the file. [out] `rc` – return code.	N/A
`GetFsSize`	Purpose Lets you get the size of the file system. Parameters [out] `fsSize` – size of the file system in bytes. [out] `rc` – return code.	N/A

Methods of the fs.FSUnsafe endpoint (kl.core.FSUnsafe interface)

Method	Method purpose and parameters	Potential danger of the method
`Change`	Purpose Changes the file system image. A different ROMFS image loaded into process memory will be used instead of the ROMFS image that was created during the solution build. Parameters [in] `base` – pointer to the file system image. [in] `size` – size of the file system image in bytes. [out] `rc` – return code.	Allows the following: Use an ROMFS image containing arbitrary programs and data. Gain read-access to some kernel objects.

Method

Method purpose and parameters

Potential danger of the method

Change

Purpose

Changes the file system image.

A different ROMFS image loaded into process memory will be used instead of the ROMFS image that was created during the solution build.

Parameters

[in] base – pointer to the file system image.
[in] size – size of the file system image in bytes.
[out] rc – return code.

Allows the following:

Use an ROMFS image containing arbitrary programs and data.
Gain read-access to some kernel objects.

Did you find this article helpful?

What can we do better?

Thank you for your feedback! You're helping us improve.