NAME
pam_namespace - PAM module for configuring namespace for a session
SYNOPSIS
pam_namespace.so [debug] [unmnt_remnt] [unmnt_only] [require_selinux] [gen_hash] [ignore_config_error] [ignore_instance_parent_mode] [unmount_on_close] [use_current_context] [use_default_context] [mount_private]
DESCRIPTION
The pam_namespace PAM module sets up a private namespace for a session with polyinstantiated directories. A polyinstantiated directory provides a different instance of itself based on user name, or when using SELinux, user name, security context or both. If an executable script /etc/security/namespace.init exists, it is used to initialize the instance directory after it is set up and mounted on the polyinstantiated directory. The script receives the polyinstantiated directory path, the instance directory path, flag whether the instance directory was newly created (0 for no, 1 for yes), and the user name as its arguments. The script is invoked with full root privileges and accessing the instance directory in this context needs to be done with caution, as it is controlled by the unprivileged user for which it has been created.
The pam_namespace module disassociates the session namespace from the parent namespace. Any mounts/unmounts performed in the parent namespace, such as mounting of devices, are not reflected in the session namespace. To propagate selected mount/unmount events from the parent namespace into the disassociated session namespace, an administrator may use the special shared-subtree feature. For additional information on shared-subtree feature, please refer to the mount(8) man page and the shared-subtree description at http://lwn.net/Articles/159077 and http://lwn.net/Articles/159092.
OPTIONS
debug
unmnt_remnt
unmnt_only
require_selinux
gen_hash
ignore_config_error
ignore_instance_parent_mode
unmount_on_close
use_current_context
use_default_context
mount_private
Note that mounts and unmounts done in the private namespace will not affect the parent namespace if this option is used or when the shared / mount point is autodetected.
MODULE TYPES PROVIDED
Only the session module type is provided. The module must not be called from multithreaded processes.
RETURN VALUES
PAM_SUCCESS
PAM_SERVICE_ERR
PAM_SESSION_ERR
FILES
/etc/security/namespace.conf
/etc/security/namespace.d
/etc/security/namespace.init
EXAMPLES
For the <service>s you need polyinstantiation (login for example) put the following line in /etc/pam.d/<service> as the last line for session group:
session required pam_namespace.so [arguments]
To use polyinstantiation with graphical display manager gdm, please refer to gdm's documentation.
SEE ALSO
namespace.conf(5), pam.d(5), mount(8), pam(7).
AUTHORS
The namespace setup scheme was designed by Stephen Smalley, Janak Desai and Chad Sellers. The pam_namespace PAM module was developed by Janak Desai <[email protected]>, Chad Sellers <[email protected]> and Steve Grubb <[email protected]>. Additional improvements by Xavier Toth <[email protected]> and Tomas Mraz <[email protected]>.