default_contexts - Linux

Overview

default_contexts is a powerful command used to manage the SELinux (Security-Enhanced Linux) security contexts of files and directories on Linux systems. It allows administrators to set default security contexts for newly created files and directories, ensuring that they inherit the appropriate security labels.

Syntax

default_contexts [-c, --contexts] [-C, --copycontexts] [-h, --help] [-m, --modify] [-P, --preserve] [-r, --restore] [-s, --setexeccontext] [-t, --type] [-u, --usercontexts] [-v, --version]

Options/Flags

-c, –contexts
Print the current default file contexts.

-C, –copycontexts
Copy the file contexts from a source path to a destination path.

-h, –help
Display help information.

-m, –modify
Modify the default file contexts for specified paths.

-P, –preserve
Preserve the current file contexts when modifying or restoring.

-r, –restore
Restore the default file contexts from a backup file.

-s, –setexeccontext
Set the default security context for executable files.

-t, –type
Specify the type of the context to modify (e.g., file, dir).

-u, –usercontexts
Print the current default user contexts.

-v, –version
Display version information.

Examples

Setting the default file context for a directory:

$ default_contexts -t dir -m /home/user

Restoring the default file contexts from a backup:

$ default_contexts -r /tmp/default_contexts.bak

Copying the file contexts from one directory to another:

$ default_contexts -C /source-dir /destination-dir

Common Issues

  • Permission denied: Ensure that you have root privileges to modify the default file contexts.
  • SELinux is disabled: Make sure that SELinux is enabled on your system.
  • Invalid context: Verify that the specified security context is valid.

Integration

default_contexts can be used in conjunction with the following commands:

  • restorecon: Restores the security contexts of files and directories.
  • semanage: Manages SELinux security policies.

Related Commands

  • chcon: Change the security context of a file or directory.
  • lscon: List the security context of a file or directory.
  • semanage fcontext: Manage file security contexts.