linux/security/selinux
Stephen Smalley c6d3aaa4e3 selinux: dynamic class/perm discovery
Modify SELinux to dynamically discover class and permission values
upon policy load, based on the dynamic object class/perm discovery
logic from libselinux.  A mapping is created between kernel-private
class and permission indices used outside the security server and the
policy values used within the security server.

The mappings are only applied upon kernel-internal computations;
similar mappings for the private indices of userspace object managers
is handled on a per-object manager basis by the userspace AVC.  The
interfaces for compute_av and transition_sid are split for kernel
vs. userspace; the userspace functions are distinguished by a _user
suffix.

The kernel-private class indices are no longer tied to the policy
values and thus do not need to skip indices for userspace classes;
thus the kernel class index values are compressed.  The flask.h
definitions were regenerated by deleting the userspace classes from
refpolicy's definitions and then regenerating the headers.  Going
forward, we can just maintain the flask.h, av_permissions.h, and
classmap.h definitions separately from policy as they are no longer
tied to the policy values.  The next patch introduces a utility to
automate generation of flask.h and av_permissions.h from the
classmap.h definitions.

The older kernel class and permission string tables are removed and
replaced by a single security class mapping table that is walked at
policy load to generate the mapping.  The old kernel class validation
logic is completely replaced by the mapping logic.

The handle unknown logic is reworked.  reject_unknown=1 is handled
when the mappings are computed at policy load time, similar to the old
handling by the class validation logic.  allow_unknown=1 is handled
when computing and mapping decisions - if the permission was not able
to be mapped (i.e. undefined, mapped to zero), then it is
automatically added to the allowed vector.  If the class was not able
to be mapped (i.e. undefined, mapped to zero), then all permissions
are allowed for it if allow_unknown=1.

avc_audit leverages the new security class mapping table to lookup the
class and permission names from the kernel-private indices.

The mdp program is updated to use the new table when generating the
class definitions and allow rules for a minimal boot policy for the
kernel.  It should be noted that this policy will not include any
userspace classes, nor will its policy index values for the kernel
classes correspond with the ones in refpolicy (they will instead match
the kernel-private indices).

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-10-07 21:56:42 +11:00
..
include selinux: dynamic class/perm discovery 2009-10-07 21:56:42 +11:00
ss selinux: dynamic class/perm discovery 2009-10-07 21:56:42 +11:00
avc.c selinux: dynamic class/perm discovery 2009-10-07 21:56:42 +11:00
exports.c Creds: creds->security can be NULL is selinux is disabled 2009-09-14 12:34:07 +10:00
hooks.c SELinux: reset the security_ops before flushing the avc cache 2009-09-30 19:17:06 +10:00
Kconfig selinux: Deprecate and schedule the removal of the the compat_net functionality 2008-12-31 12:54:11 -05:00
Makefile SELinux: Add network port SID cache 2008-04-18 20:26:16 +10:00
netif.c SELinux fixups needed for preemptable RCU from -rt 2008-04-22 15:37:23 +10:00
netlabel.c SELinux: Convert avc_audit to use lsm_audit.h 2009-08-17 08:37:18 +10:00
netlink.c SELinux: netlink.c whitespace, syntax, and static declaraction cleanups 2008-04-21 19:05:05 +10:00
netnode.c SELinux: keep the code clean formating and syntax 2008-07-14 15:01:36 +10:00
netport.c SELinux: keep the code clean formating and syntax 2008-07-14 15:01:36 +10:00
nlmsgtab.c SELinux: define audit permissions for audit tree netlink messages 2009-06-03 07:44:53 +10:00
selinuxfs.c selinux: dynamic class/perm discovery 2009-10-07 21:56:42 +11:00
xfrm.c SELinux: Convert avc_audit to use lsm_audit.h 2009-08-17 08:37:18 +10:00