Follow Techotopia on Twitter

On-line Guides
All Guides
eBook Store
iOS / Android
Linux for Beginners
Office Productivity
Linux Installation
Linux Security
Linux Utilities
Linux Virtualization
Linux Kernel
System/Network Admin
Programming
Scripting Languages
Development Tools
Web Development
GUI Toolkits/Desktop
Databases
Mail Systems
openSolaris
Eclipse Documentation
Techotopia.com
Virtuatopia.com
Answertopia.com

How To Guides
Virtualization
General System Admin
Linux Security
Linux Filesystems
Web Servers
Graphics & Desktop
PC Hardware
Windows
Problem Solutions
Privacy Policy

  




 

 

The Guide to Writing SELinux Policy
Prev Home Next

10. the flask directory


The flask directory contains the following files:

access_vectors
This file defines the actions that can be performed for various classes. For the file class, you may perform actions such as read, write, link and so forth. For the socket class, you can perform actions like bind (for binding to a socket such as a TCP or UDP socket), listen (for incoming connections), connect and so on. Take a look through this file to familiarise yourself with the different actions various classes may perform.

initial_sids
This file defines the initial SIDS (Security Identifiers). In the old SE Linux, SIDS were used in the userspace interface to the kernel. PSIDs (Persistent SIDs) were used in the kernel code for mapping files to contexts for files and directories on disk. See the NSA's document "Configuring the SELinux Policy" document for more information. In the new SE Linux, the extended attributes contain the context so SIDs and PSIDs are no longer necessary. Even though the new SE Linux uses extended attributes, some initial contexts still need to be defined when a system is started. The initial_sids file contains the initial SID contstants. The file initial_sid_contexts in your policy source directory maps these initial SIDS to contexts, and some examples follow:

sid kernel      system_u:system_r:kernel_t
sid security    system_u:object_r:security_t
The first line defines the initial SID of kernel, and gets the context of system_u:system_r:kernel_t . kernel_t is the type for general kernel code. The second line gives the sid security the context of system_u:object_r:security_t where security_t is the type for the /selinux file system.

security_classes
This file defines the security object classes. These are the classes for things such as files and networking.

An in-depth discussion of the Flask architecture is way beyond the scope of this document, but more information can be found in the NSA document "Configuring the SELinux Policy", particularly the section "Architectural Concepts and Definitions", at https://www.nsa.gov/selinux/doc/policy2/x34.html

The Guide to Writing SELinux Policy
Prev Home Next

 
 
  Published with kind permission of Faye Coker Design by Interspire