• Serge E. Hallyn's avatar
    selinux: add support for installing a dummy policy (v2) · 93c06cbb
    Serge E. Hallyn authored
    In August 2006 I posted a patch generating a minimal SELinux policy.  This
    week, David P. Quigley posted an updated version of that as a patch against
    the kernel.  It also had nice logic for auto-installing the policy.
    Following is David's original patch intro (preserved especially
    bc it has stats on the generated policies):
    se interested in the changes there were only two significant
    changes. The first is that the iteration through the list of classes
    used NULL as a sentinel value. The problem with this is that the
    class_to_string array actually has NULL entries in its table as place
    holders for the user space object classes.
    The second change was that it would seem at some point the initial sids
    table was NULL terminated. This is no longer the case so that iteration
    has to be done on array length instead of looking for NULL.
    Some statistics on the policy that it generates:
    The policy consists of 523 lines which contain no blank lines. Of those
    523 lines 453 of them are class, permission, and initial sid
    definitions. These lines are usually little to no concern to the policy
    developer since they will not be adding object classes or permissions.
    Of the remaining 70 lines there is one type, one role, and one user
    statement. The remaining lines are broken into three portions. The first
    group are TE allow rules which make up 29 of the remaining lines, the
    second is assignment of labels to the initial sids which consist of 27
    lines, and file system labeling statements which are the remaining 11.
    In addition to the policy.conf generated there is a single file_contexts
    file containing two lines which labels the entire system with base_t.
    This policy generates a policy.23 binary that is 7920 bytes.
    (then a few versions later...):
    The new policy is 587 lines (stripped of blank lines) with 476 of those
    lines being the boilerplate that I mentioned last time. The remaining
    111 lines have the 3 lines for type, user, and role, 70 lines for the
    allow rules (one for each object class including user space object
    classes), 27 lines to assign types to the initial sids, and 11 lines for
    file system labeling. The policy binary is 9194 bytes.
    	Aug 26: Added Documentation/SELinux.txt
    	Aug 26: Incorporated a set of comments by Stephen Smalley:
    		1. auto-setup SELINUXTYPE=dummy
    		2. don't auto-install if selinux is enabled with
    			non-dummy policy
    		3. don't re-compute policy version
    		4. /sbin/setfiles not /usr/sbin/setfiles
    	Aug 22: As per JMorris comments, made sure make distclean
    		cleans up the mdp directory.
    		Removed a check for file_contexts which is now
    		created in the same file as the check, making it
    Signed-off-by: default avatarSerge Hallyn <serue@us.ibm.com>
    Signed-off-by: default avatarDavid Quigley <dpquigl@tycho.nsa.gov>
    Signed-off-by: default avatarJames Morris <jmorris@namei.org>
README 91 Bytes