semanage – Query and Modify the Security Context of the Default Directory

semanage is a Linux command that is used to query and modify the security context of the default directory. This command is part of the policycoreutils-python package and is used for managing SELinux policies. SELinux stands for Security Enhanced Linux, and it is a security module that provides mandatory access control (MAC) to the Linux kernel.

Overview

The semanage command is used to manage the SELinux policy on a Linux system. This command can be used to query and modify the security context of the default directory. The default directory is the directory where the SELinux policy is stored. The security context of a file or directory is a set of attributes that define the security policy for that file or directory. These attributes include the file type, the file label, and the file mode.

Querying the Security Context of the Default Directory

To query the security context of the default directory, use the following command:

semanage fcontext -l

This command will display a list of all the file contexts that are defined in the SELinux policy.

Modifying the Security Context of the Default Directory

To modify the security context of the default directory, use the following command:

semanage fcontext -a -t <file_type> <directory_path>

This command will add a new file context to the SELinux policy. The <file_type> parameter specifies the type of file that the context applies to, and the <directory_path> parameter specifies the path to the directory that the context applies to.

Examples

Here are some examples of how to use the semanage command:

Example 1: Querying the Security Context of the Default Directory

semanage fcontext -l

This command will display a list of all the file contexts that are defined in the SELinux policy.

Example 2: Modifying the Security Context of the Default Directory

semanage fcontext -a -t httpd_sys_content_t /var/www/html

This command will add a new file context to the SELinux policy. The httpd_sys_content_t file type specifies that the context applies to files that are served by the Apache web server. The /var/www/html directory path specifies the directory that the context applies to.

Options

The following table lists all the available options for the semanage command:

Option	Description
-l	Lists all the file contexts that are defined in the SELinux policy.
-a	Adds a new file context to the SELinux policy.
-t	Specifies the file type that the context applies to.
-d	Deletes a file context from the SELinux policy.
-u	Updates an existing file context in the SELinux policy.
-r	Restores the default file contexts in the SELinux policy.

Troubleshooting Tips

Here are some troubleshooting tips for using the semanage command:

• If you get an error message that says “semanage: command not found”, make sure that the policycoreutils-python package is installed on your system.
• If you get an error message that says “Permission denied”, make sure that you have the necessary permissions to modify the SELinux policy.

Notes

Here are some additional notes about the semanage command:

• The semanage command should be used with caution, as modifying the SELinux policy can have unintended consequences.
• The file contexts that are defined in the SELinux policy are stored in the /etc/selinux/targeted/contexts/files/file_contexts file.