Quoting Casey Schaufler (casey@schaufler-ca.com):
quoted text
> 
> From: Casey Schaufler <casey@schaufler-ca.com>
> 
> Smack is the Simplified Mandatory Access Control Kernel.
> 
> Smack implements mandatory access control (MAC) using labels
> attached to tasks and data containers, including files, SVIPC,
> and other tasks. Smack is a kernel based scheme that requires
> an absolute minimum of application support and a very small
> amount of configuration data.
> 
> Smack is implemented as a clean LSM. It requires no external
> code changes and the patch modifies only the Kconfig and Makefile
> in the security directory. Smack uses extended attributes and
> provides a set of general mount options, borrowing technics used
> elsewhere. Smack uses netlabel for CIPSO labeling. Smack provides
> a pseudo-filesystem smackfs that is used for manipulation of
> system Smack attributes.
> 
> The patch, patches for ls and sshd, a README, a startup script,
> and x86 binaries for ls and sshd are also available on
> 
>     http:/www.schaufler-ca.com
> 
> The patch has been tested with 2.6.22, 2.6.23-rc8, and
> 2.6.23-rc8-mm2. Development has been done using Fedora Core 7
> in a virtual machine environment and on an old Sony laptop.
> 
> Smack provides mandatory access controls based on the label attached
> to a task and the label attached to the object it is attempting to
> access. Smack labels are deliberately short (1-23 characters) text
> strings. Single character labels using special characters are reserved
> for system use. The only operation applied to Smack labels is equality
> comparison. No wildcards or expressions, regular or otherwise, are
> used.
> 
> A file always gets the Smack label of the task that created it.
> 
> Smack defines and uses these labels:
> 
>     "*" - pronounced "star"
>     "_" - pronounced "floor"
>     "^" - pronounced "hat"
>     "?" - pronounced "huh"
> 
> The access rules enforced by Smack are, in order:
> 
> 1. Any access requested by a task labeled "*" is denied.
> 2. A read or execute access requested by a task labeled "^"
>    is permitted.
> 3. A read or execute access requested on an object labeled "_"
>    is permitted.
> 4. Any access requested on an object labeled "*" is permitted.
> 5. Any access requested by a task on an object with the same
>    label is permitted.
> 6. Any access requested that is explicitly defined in the loaded
>    rule set is permitted.
> 7. Any other access is denied.
> 
> Rules may be explicitly defined by writing subject,object,access
> triples to /smack/load.
> 
> Smack rule sets can be easily defined that describe Bell&LaPadula
> sensitivity, Biba integrity, and a variety of interesting
> configurations. Smack rule sets can be modified on the fly to
> accomodate changes in the operating environment or even the time
> of day.
> 
> Some practical use cases:
> 
> Hierarchical levels. The less common of the two usual uses
> for MLS systems is to define hierarchical levels, often
> unclassified, confidential, secret, and so on. To set up smack
> to support this, these rules could be defined:
> 
>    C        Unclass rx
>    S        C       rx
>    S        Unclass rx
>    TS       S       rx
>    TS       C       rx
>    TS       Unclass rx
> 
> A TS process can read S, C, and Unclass data, but cannot write it.
> An S process can read C and Unclass. Note that specifying that
> TS can read S and S can read C does not imply TS can read C, it
> has to be explicitly stated.
> 
> Non-hierarchical categories. This is the more common of the
> usual uses for an MLS system. Since the default rule is that a
> subject cannot access an object with a different label no
> access rules are required to implement compartmentalization.
> 
> A case that the Bell & LaPadula policy does not allow is demonstrated
> with this Smack access rule:
> 
> A case that Bell&LaPadula does not allow that Smack does:
> 
>     ESPN    ABC   r
>     ABC     ESPN  r
> 
> On my portable video device I have two applications, one that
> shows ABC programming and the other ESPN programming. ESPN wants
> to show me sport stories that show up as news, and ABC will
> only provide minimal information about a sports story if ESPN
> is covering it. Each side can look at the other's info, neither
> can change the other. Neither can see what FOX is up to, which
> is just as well all things considered.
> 
> Another case that I especially like:
> 
>     SatData Guard   w
>     Guard   Publish w
> 
> A program running with the Guard label opens a UDP socket and
> accepts messages sent by a program running with a SatData label.
> The Guard program inspects the message to ensure it is wholesome
> and if it is sends it to a program running with the Publish label.
> This program then puts the information passed in an appropriate
> place. Note that the Guard program cannot write to a Publish
> file system object because file system semanitic require read as
> well as write.
> 
> The four cases (categories, levels, mutual read, guardbox) here
> are all quite real, and problems I've been asked to solve over
> the years. The first two are easy to do with traditonal MLS systems
> while the last two you can't without invoking privilege, at least
> for a while.
> 
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> 
> ---
>  
> Changes since the previous version:
> 
> - Smack labels can now be up to 23 characters in length. My UI
>   expert advised that 12 was the absolute minimum, and CIPSO
>   starts to get troublesome at 30.
> 
> - Reading the SMACK64PACKET attribute from a socket used to provide
>   the label of the last packet delivered. Now it provides the label
>   of the packet returned by the most recent recv call, or ENOATTR
>   if that value is not available. It's better to get no value than
>   an incorrect value.
> 
>  Documentation/Smack.txt       |  104 +
>  security/Kconfig              |    1 
>  security/Makefile             |    2 
>  security/smack/Kconfig        |   10 
>  security/smack/Makefile       |    9 
>  security/smack/smack.h        |  207 ++
>  security/smack/smack_access.c |  345 ++++
>  security/smack/smack_lsm.c    | 2685 ++++++++++++++++++++++++++++++++
>  security/smack/smackfs.c      | 1201 ++++++++++++++
>  9 files changed, 4564 insertions(+)
> 
> diff -uprN -X linux-2.6.23-rc8-base/Documentation/dontdiff linux-2.6.23-rc8-base/Documentation/Smack.txt linux-2.6.23-rc8-smack/Documentation/Smack.txt
> --- linux-2.6.23-rc8-base/Documentation/Smack.txt	1969-12-31 16:00:00.000000000 -0800
> +++ linux-2.6.23-rc8-smack/Documentation/Smack.txt	2007-09-25 15:30:37.000000000 -0700
> @@ -0,0 +1,104 @@
> +
> +
> +    "Good for you, you've decided to clean the elevator!"
> +    - The Elevator, from Dark Star
> +
> +Smack is the the Simplified Mandatory Access Control Kernel.
> +Smack is a kernel based implementation of mandatory access
> +control that includes simplicity in its primary design goals.
> +
> +Smack does not implement Domain Type Enforcement (DTE). If
> +you want DTE Linux has an implementation called SELinux.
> +Those who really want DTE are encouraged to use SELinux.
> +Those who don't know what DTE is are encouraged to compare
> +SELinux with Smack to determine which mechanisms are best
> +suited to the problem at hand.
> +
> +Smack consists of three major components:
> +    - The kernel
> +    - A start-up script and a few modified applications
> +    - Configuration data
> +
> +The kernel component of Smack is implemented as a Linux
> +Security Modules (LSM) module. It requires netlabel and
> +works best with file systems that support extended attributes,
> +although xattr support is not strictly required. The Smack
> +patch is (currently) self contained, except for Kconfig
> +and Makefile changes in the security directory. It is safe
> +to run a Smack kernel under a "vanilla" distribution.
> +Smack kernels use the CIPSO IP option. Some network
> +configurations are intolerant of IP options and can impede
> +access to systems that use them as Smack does.
> +
> +The startup script etc-init.d-smack should be installed
> +in /etc/init.d/smack and should be invoked early in the
> +start-up process. On Fedora rc5.d/S02smack is recommended.
> +This script ensures that certain devices have the correct
> +Smack attributes and loads the Smack configuration if
> +any is defined.
> +
> +A version of "ls" that provides a "-M" option to display
> +Smack labels on long listing is available.
> +
> +A hacked version of sshd that allows network logins by users
> +with specific Smack labels is available. This version does
> +not work for scp. You must set the /etc/ssh/sshd_config
> +line:
> +   UsePrivilegeSeparation no
> +
> +The format of /etc/smack/usr is:
> +
> +   username smack
> +
> +In keeping with the intent of Smack, configuration data is
> +minimal and not strictly required. The most important
> +configuration step is mounting the smackfs pseudo filesystem.
> +
> +Add this line to /etc/fstab:
> +
> +    smackfs /smack smackfs smackfsdef=* 0 0
> +
> +and create the /smack directory for mounting.
> +
> +Smack uses extended attributes (xattrs) to store file labels.
> +The command to set a Smack label on a file is:
> +
> +    # attr -S -s SMACK64 -V "value" path
> +
> +NOTE: Smack labels are limited to 23 characters. The attr command
> +      does not enforce this restriction and can be used to set
> +      invalid Smack labels on files.
> +
> +The smackfs filesystem treats symbolic links in a special way.
> +The Smack label of the process is appended to the link value
> +during resolution. To provide a /tmp that is available to users
> +with multiple labels:
> +
> +    # mkdir /moldy
> +    # mv /tmp /moldy/_
> +    # ln -s /smack/tmp /tmp
> +
> +For each label users are going to use:
> +
> +    # mkdir /moldy/label
> +    # chmod <appropriate-value> /moldy/label
> +    # attr -S -s SMACK64 -V "label" /moldy/label
> +
> +If you don't do anything special all users will get the floor ("_")
> +label when they log in. If you do want to log in via the hacked ssh
> +at other labels use the attr command to set the smack value on the
> +home directory and it's contents.
> +
> +You can add access rules in /etc/smack/accesses. They take the form:
> +
> +    subjectlabel objectlabel access
> +
> +access is a combination of the letters rwxa which specify the
> +kind of access permitted a subject with subjectlabel on an
> +object with objectlabel. If there is no rule no access is allowed.
> +
> +A process can see the smack label it is running with by
> +reading /proc/self/attr/current. A privileged process can
> +set the process smack by writing there.

Ok, so to control smack label transitions, basically you would
run with CAP_MAC_OVERRIDE (see my note later) so that you're
allowed to change your smack label by writing to
/proc/self/attr/current, then you drop CAP_MAC_OVERRIDE, then you're
no longer able to change your label?  I.e. no inherent label changing
rules through smack itself?

Just making sure I have that right.  If I do, then I think at least
defining the word 'privileged' above, given that this is mac,
would help.

quoted text
> +
> +
> diff -uprN -X linux-2.6.23-rc8-base/Documentation/dontdiff linux-2.6.23-rc8-base/security/Kconfig linux-2.6.23-rc8-smack/security/Kconfig
> --- linux-2.6.23-rc8-base/security/Kconfig	2007-07-08 16:32:17.000000000 -0700
> +++ linux-2.6.23-rc8-smack/security/Kconfig	2007-09-25 15:30:37.000000000 -0700
> @@ -94,6 +94,7 @@ config SECURITY_ROOTPLUG
>  	  If you are unsure how to answer this question, answer N.
>  
>  source security/selinux/Kconfig
> +source security/smack/Kconfig
>  
>  endmenu
>  
> diff -uprN -X linux-2.6.23-rc8-base/Documentation/dontdiff linux-2.6.23-rc8-base/security/Makefile linux-2.6.23-rc8-smack/security/Makefile
> --- linux-2.6.23-rc8-base/security/Makefile	2007-07-08 16:32:17.000000000 -0700
> +++ linux-2.6.23-rc8-smack/security/Makefile	2007-09-25 15:30:37.000000000 -0700
> @@ -4,6 +4,7 @@
>  
>  obj-$(CONFIG_KEYS)			+= keys/
>  subdir-$(CONFIG_SECURITY_SELINUX)	+= selinux
> +subdir-$(CONFIG_SECURITY_SMACK)		+= smack
>  
>  # if we don't select a security model, use the default capabilities
>  ifneq ($(CONFIG_SECURITY),y)
> @@ -14,5 +15,6 @@ endif
>  obj-$(CONFIG_SECURITY)			+= security.o dummy.o inode.o
>  # Must precede capability.o in order to stack properly.
>  obj-$(CONFIG_SECURITY_SELINUX)		+= selinux/built-in.o
> +obj-$(CONFIG_SECURITY_SMACK)		+= commoncap.o smack/built-in.o
>  obj-$(CONFIG_SECURITY_CAPABILITIES)	+= commoncap.o capability.o
>  obj-$(CONFIG_SECURITY_ROOTPLUG)		+= commoncap.o root_plug.o
> diff -uprN -X linux-2.6.23-rc8-base/Documentation/dontdiff linux-2.6.23-rc8-base/security/smack/Kconfig linux-2.6.23-rc8-smack/security/smack/Kconfig
> --- linux-2.6.23-rc8-base/security/smack/Kconfig	1969-12-31 16:00:00.000000000 -0800
> +++ linux-2.6.23-rc8-smack/security/smack/Kconfig	2007-09-25 15:30:38.000000000 -0700
> @@ -0,0 +1,10 @@
> +config SECURITY_SMACK
> +	bool "Simplified Mandatory Access Control Kernel Support"
> +	depends on NETLABEL && SECURITY_NETWORK
> +	default n
> +	help
> +	  This selects the Simplified Mandatory Access Control Kernel.
> +	  Smack is useful for sensitivity, integrity, and a variety
> +	  of other mandatory security schemes.
> +	  If you are unsure how to answer this question, answer N.

Might point out that no other modules must be compiled in along with
smack, and that smack will do posix capabilities.

quoted text
> +
> diff -uprN -X linux-2.6.23-rc8-base/Documentation/dontdiff linux-2.6.23-rc8-base/security/smack/Makefile linux-2.6.23-rc8-smack/security/smack/Makefile
> --- linux-2.6.23-rc8-base/security/smack/Makefile	1969-12-31 16:00:00.000000000 -0800
> +++ linux-2.6.23-rc8-smack/security/smack/Makefile	2007-09-25 15:30:38.000000000 -0700
> @@ -0,0 +1,9 @@
> +#
> +# Makefile for the SMACK LSM
> +#
> +
> +obj-$(CONFIG_SECURITY_SMACK) := smack.o
> +
> +smack-y := smack_lsm.o smack_access.o smackfs.o
> +
> +EXTRA_CFLAGS += -Inet/netlabel
> diff -uprN -X linux-2.6.23-rc8-base/Documentation/dontdiff linux-2.6.23-rc8-base/security/smack/smack_access.c linux-2.6.23-rc8-smack/security/smack/smack_access.c
> --- linux-2.6.23-rc8-base/security/smack/smack_access.c	1969-12-31 16:00:00.000000000 -0800
> +++ linux-2.6.23-rc8-smack/security/smack/smack_access.c	2007-09-25 15:30:38.000000000 -0700
> @@ -0,0 +1,345 @@
> +/*
> + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
> + *
> + *      This program is free software; you can redistribute it and/or modify
> + *      it under the terms of the GNU General Public License as published by
> + *      the Free Software Foundation, version 2.
> + *
> + * Author:
> + *      Casey Schaufler <casey@schaufler-ca.com>
> + *
> + */
> +
> +#include <linux/types.h>
> +#include <linux/fs.h>
> +#include <linux/sched.h>
> +#include "smack.h"
> +
> +struct smack_known smack_known_unset = {
> +	.smk_next	= NULL,
> +	.smk_known	= "UNSET",
> +	.smk_secid	= 1,
> +	.smk_cipso	= NULL,
> +};
> +
> +struct smack_known smack_known_huh = {
> +	.smk_next	= &smack_known_unset,
> +	.smk_known	= "?",
> +	.smk_secid	= 2,
> +	.smk_cipso	= NULL,
> +};
> +
> +struct smack_known smack_known_hat = {
> +	.smk_next	= &smack_known_huh,
> +	.smk_known	= "^",
> +	.smk_secid	= 3,
> +	.smk_cipso	= NULL,
> +};
> +
> +struct smack_known smack_known_star = {
> +	.smk_next	= &smack_known_hat,
> +	.smk_known	= "*",
> +	.smk_secid	= 4,
> +	.smk_cipso	= NULL,
> +};
> +
> +struct smack_known smack_known_floor = {
> +	.smk_next	= &smack_known_star,
> +	.smk_known	= "_",
> +	.smk_secid	= 5,
> +	.smk_cipso	= NULL,
> +};
> +
> +struct smack_known smack_known_invalid = {
> +	.smk_next	= &smack_known_floor,
> +	.smk_known	= "",
> +	.smk_secid	= 6,
> +	.smk_cipso	= NULL,
> +};
> +
> +struct smack_known *smack_known = &smack_known_invalid;
> +/*
> + * The initial value needs to be bigger than any of the
> + * known values above.
> + */
> +static u32 smack_next_secid = 10;
> +
> +extern struct smk_list_entry *smack_list;
> +
> +/**
> + * smk_access - determine if a subject has a specific access to an object
> + * @subject_label: a pointer to the subject's Smack label
> + * @object_label: a pointer to the object's Smack label
> + * @request: the access requested, in "MAY" format
> + *
> + * This function looks up the subject/object pair in the
> + * access rule list and returns 0 if the access is permitted,
> + * non zero otherwise.
> + *
> + * Even though Smack labels are usually shared on smack_list
> + * labels that come in off the network can't be imported
> + * and added to the list for locking reasons.
> + *
> + * Therefore, it is necessary to check the contents of the labels,
> + * not just the pointer values. Of course, in most cases the labels
> + * will be on the list, so checking the pointers may be a worthwhile
> + * optimization.
> + */
> +int smk_access(char *subject_label, char *object_label, int request)
> +{
> +	u32 may = MAY_NOT;
> +	struct smk_list_entry *sp;
> +	struct smack_rule *srp;
> +
> +	/*
> +	 * Hardcoded comparisons.
> +	 *
> +	 * A star subject can't access any object.
> +	 */
> +	if (subject_label == smack_known_star.smk_known ||
> +	    strcmp(subject_label, smack_known_star.smk_known) == 0)
> +		return -EACCES;
> +	/*
> +	 * A star object can be accessed by any subject.
> +	 */
> +	if (object_label == smack_known_star.smk_known ||
> +	    strcmp(object_label, smack_known_star.smk_known) == 0)
> +		return 0;
> +	/*
> +	 * An object can be accessed in any way by a subject
> +	 * with the same label.
> +	 */
> +	if (subject_label == object_label ||
> +	    strcmp(subject_label, object_label) == 0)
> +		return 0;
> +	/*
> +	 * A hat subject can read any object.
> +	 * A floor object can be read by any subject.
> +	 */
> +	if ((request & MAY_ANYREAD) == request) {
> +		if (object_label == smack_known_floor.smk_known ||
> +		    strcmp(object_label, smack_known_floor.smk_known) == 0)
> +			return 0;
> +		if (subject_label == smack_known_hat.smk_known ||
> +		    strcmp(subject_label, smack_known_hat.smk_known) == 0)
> +			return 0;
> +	}
> +	/*
> +	 * Beyond here an explicit relationship is required.
> +	 * If the requested access is contained in the available
> +	 * access (e.g. read is included in readwrite) it's
> +	 * good.
> +	 */
> +	for (sp = smack_list; sp != NULL; sp = sp->smk_next) {
> +		srp = &sp->smk_rule;
> +
> +		if (srp->smk_subject == subject_label ||
> +		    strcmp(srp->smk_subject, subject_label) == 0) {
> +			if (srp->smk_object == object_label ||
> +			    strcmp(srp->smk_object, object_label) == 0) {
> +				may = srp->smk_access;
> +				break;
> +			}
> +		}
> +	}
> +	/*
> +	 * This is a bit map operation.
> +	 */
> +	if ((request & may) == request)
> +		return 0;
> +
> +	return -EACCES;
> +}
> +
> +/**
> + * smk_curacc - determine if current has a specific access to an object
> + * @object_label: a pointer to the object's Smack label
> + * @request: the access requested, in "MAY" format
> + *
> + * This function checks the current subject label/object label pair
> + * in the access rule list and returns 0 if the access is permitted,
> + * non zero otherwise. It allows that current my have the capability
> + * to override the rules.
> + */
> +int smk_curacc(char *obj_label, u32 mode)
> +{
> +	int rc;
> +
> +	rc = smk_access(current->security, obj_label, mode);
> +	if (rc == 0)
> +		return 0;
> +	
> +	if (capable(CAP_MAC_OVERRIDE))
> +		return 0;
> +
> +	return rc;
> +}
> +
> +extern struct mutex smack_known_lock;
> +
> +/**
> + * smk_import_entry - import a label, return the list entry
> + * @string: a text string that might be a Smack label
> + * @len: the maximum size, or zero if it is NULL terminated.
> + *
> + * Returns a pointer to the entry in the label list that
> + * matches the passed string, adding it if necessary.
> + */
> +struct smack_known *smk_import_entry(const char *string, int len)
> +{
> +	struct smack_known *skp;
> +	char smack[SMK_LABELLEN];
> +	int found;
> +	int i;
> +
> +	if (len <= 0 || len > SMK_MAXLEN)
> +		len = SMK_MAXLEN;
> +
> +	for (i = 0, found = 0; i < SMK_LABELLEN; i++) {
> +		if (found)
> +			smack[i] = '__PLACEHOLDER__2_';
> +		else if (i >= len || string[i] > '~' || string[i] <= ' ') {
> +			smack[i] = '__PLACEHOLDER__2_';
> +			found = 1;
> +		}
> +		else
> +			smack[i] = string[i];
> +	}
> +
> +	if (smack[0] == '__PLACEHOLDER__2_')
> +		return NULL;
> +
> +	mutex_lock(&smack_known_lock);
> +
> +	for (skp = smack_known; skp != NULL; skp = skp->smk_next)
> +		if (skp->smk_known == smack)
> +			break;
> +
> +	if (skp == NULL) {
> +		skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL);
> +		if (skp != NULL) {
> +			skp->smk_next = smack_known;
> +			strncpy(skp->smk_known, smack, SMK_MAXLEN);
> +			skp->smk_secid = smack_next_secid++;
> +			skp->smk_cipso = NULL;
> +			spin_lock_init(&skp->smk_cipsolock);
> +			smack_known = skp;
> +		}
> +	}
> +
> +	mutex_unlock(&smack_known_lock);
> +
> +	return skp;
> +}
> +
> +/**
> + * smk_import - import a smack label
> + * @string: a text string that might be a Smack label
> + * @len: the maximum size, or zero if it is NULL terminated.
> + *
> + * Returns a pointer to the label in the label list that
> + * matches the passed string, adding it if necessary.
> + */
> +char *smk_import(const char *string, int len)
> +{
> +	struct smack_known *skp;
> +
> +	skp = smk_import_entry(string, len);
> +	if (skp == NULL)
> +		return NULL;
> +	return skp->smk_known;
> +}
> +
> +/**
> + * smack_from_secid - find the Smack label associated with a secid
> + * @secid: an integer that might be associated with a Smack label
> + *
> + * Returns a pointer to the appropraite Smack label if there is one,
> + * otherwise a pointer to the invalid Smack label.
> + */
> +char *smack_from_secid(const u32 secid)
> +{
> +	struct smack_known *skp;
> +
> +	for (skp = smack_known; skp != NULL; skp = skp->smk_next)
> +		if (skp->smk_secid == secid)
> +			return skp->smk_known;
> +
> +	/*
> +	 * If we got this far someone asked for the translation
> +	 * of a secid that is not on the list.
> +	 */
> +	return smack_known_invalid.smk_known;
> +}
> +
> +u32 smack_to_secid(const char *smack)
> +{
> +	struct smack_known *skp;
> +
> +	for (skp = smack_known; skp != NULL; skp = skp->smk_next)
> +		if (skp->smk_known == smack)
> +			return skp->smk_secid;
> +	return 0;
> +}
> +
> +/**
> + * smack_from_cipso - find the Smack label associated with a CIPSO option
> + * @level: Bell & LaPadula level from the network
> + * @catset: Bell & LaPadula categories from the network
> + * @result: where to put the Smack value
> + *
> + * This is a simple lookup in the label table.
> + *
> + * This is an odd duck as far as smack handling goes in that
> + * it sends back a copy of the smack label rather than a pointer
> + * to the master list. This is done because it is possible for
> + * a foreign host to send a smack label that is new to this
> + * machine and hence not on the list. That would not be an
> + * issue except that adding an entry to the master list can't
> + * be done at that point.
> + */
> +void smack_from_cipso(u32 level, char *catset, char *result)
> +{
> +	struct smack_known *kp;
> +	char *final = NULL;
> +
> +	for (kp = smack_known; final == NULL && kp != NULL; kp = kp->smk_next) {
> +		if (kp->smk_cipso == NULL)
> +			continue;
> +
> +		spin_lock_bh(&kp->smk_cipsolock);
> +
> +		if (kp->smk_cipso->smk_level == level &&
> +		    memcmp(kp->smk_cipso->smk_catset,catset,SMK_LABELLEN) == 0)
> +			final = kp->smk_known;
> +
> +		spin_unlock_bh(&kp->smk_cipsolock);
> +	}
> +	if (final == NULL)
> +		final = smack_known_huh.smk_known;
> +	strncpy(result, final, SMK_MAXLEN);
> +	return;
> +}
> +
> +/**
> + * smack_to_cipso - find the CIPSO option to go with a Smack label
> + * @smack: a pointer to the smack label in question
> + * @cp: where to put the result
> + *
> + * Returns zero if a value is available, non-zero otherwise.
> + */
> +int smack_to_cipso(const char *smack, struct smack_cipso *cp)
> +{
> +        struct smack_known *kp;
> +
> +	for (kp = smack_known; kp != NULL; kp = kp->smk_next)
> +		if (kp->smk_known == smack ||
> +		    strcmp(kp->smk_known, smack) == 0)
> +			break;
> +
> +	if (kp == NULL || kp->smk_cipso == NULL)
> +		return -ENOENT;
> +	
> +	memcpy(cp, kp->smk_cipso, sizeof(struct smack_cipso));
> +	return 0;
> +}
> diff -uprN -X linux-2.6.23-rc8-base/Documentation/dontdiff linux-2.6.23-rc8-base/security/smack/smackfs.c linux-2.6.23-rc8-smack/security/smack/smackfs.c
> --- linux-2.6.23-rc8-base/security/smack/smackfs.c	1969-12-31 16:00:00.000000000 -0800
> +++ linux-2.6.23-rc8-smack/security/smack/smackfs.c	2007-09-25 15:30:38.000000000 -0700
> @@ -0,0 +1,1201 @@
> +/*
> + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
> + *
> + *	This program is free software; you can redistribute it and/or modify
> + *  	it under the terms of the GNU General Public License as published by
> + *	the Free Software Foundation, version 2.
> + *
> + * Author:
> + * 	Casey Schaufler <casey@schaufler-ca.com>
> + * 
> + * Special thanks to the authors of selinuxfs.
> + * 
> + *	Karl MacMillan <kmacmillan@tresys.com>
> + *	James Morris <jmorris@redhat.com>
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/vmalloc.h>
> +#include <linux/security.h>
> +#include <linux/mutex.h>
> +#include <net/netlabel.h>
> +/*
> + * This include could get changed when the internal
> + * netlabel interface for initializing a netlabel domain
> + * has been worked out.
> + */
> +#include "netlabel_domainhash.h"
> +#include <net/cipso_ipv4.h>
> +#include "smack.h"
> +
> +extern struct mutex smack_list_lock;
> +extern struct smack_known smack_known_floor;
> +extern struct smack_known smack_known_star;
> +extern struct smack_known *smack_known;
> +
> +/*
> + * smackfs pseudo filesystem.
> + */
> +
> +enum smk_inos {
> +	SMK_ROOT_INO	= 2,
> +	SMK_LOAD	= 3,	/* load policy */
> +	SMK_LINKS	= 4,	/* symlinks */
> +	SMK_CIPSO	= 5,	/* load label -> CIPSO mapping */
> +	SMK_DOI		= 6,	/* CIPSO DOI */
> +	SMK_DIRECT	= 7,	/* CIPSO level indicating direct label */
> +	SMK_AMBIENT	= 8,	/* internet ambient label */
> +	SMK_NLTYPE	= 9,	/* label scheme to use by default */
> +	SMK_TMP		= 100,	/* MUST BE LAST! /smack/tmp */
> +};
> +
> +/*
> + * This is the "ambient" label for network traffic.
> + * If it isn't somehow marked, use this.
> + * It can be reset via smackfs/ambient
> + */
> +char *smack_net_ambient = smack_known_floor.smk_known;
> +
> +/*
> + * This is the default packet marking scheme for network traffic.
> + * It can be reset via smackfs/nltype
> + */
> +int smack_net_nltype = NETLBL_NLTYPE_CIPSOV4;
> +
> +/*
> + * This is the level in a CIPSO header that indicates a
> + * smack label is contained directly in the category set.
> + * It can be reset via smackfs/direct
> + */
> +int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT;
> +
> +static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
> +static int smack_list_count;
> +struct smk_list_entry *smack_list;
> +
> +/*
> + * 'ssssssss oooooooo mmmm\n__PLACEHOLDER__2_' 
> + */
> +#define SMACK_RULE_LINE_SIZE (2 * SMK_MAXLEN + 6)
> +
> +/**
> + * smk_read_load - read() for /smack/load
> + * @filp: file pointer, not actually used
> + * @buf: where to put the result
> + * @count: maximum to send along
> + * @ppos: where to start
> + *
> + * Returns number of bytes read or error code, as appropriate
> + */
> +static ssize_t smk_read_load(struct file *filp, char __user *buf,
> +			     size_t count, loff_t *ppos)
> +{
> +	ssize_t bytes;
> +	struct smk_list_entry *slp = smack_list;
> +	struct smack_rule *srp;
> +	char *result;
> +	char *cp;
> +	int realbytes = 0;
> +	
> +	bytes = SMACK_RULE_LINE_SIZE * smack_list_count;
> +	if (bytes == 0)
> +		return 0;
> +
> +	result = kzalloc(bytes, GFP_KERNEL);
> +	if (result == NULL)
> +		return -ENOMEM;
> +
> +	for (cp = result; slp != NULL; slp = slp->smk_next) {
> +		srp = &slp->smk_rule;
> +		sprintf(cp, "%-8s %-8s",
> +			(char *)srp->smk_subject, (char *)srp->smk_object);
> +		cp += strlen(cp);
> +		if (srp->smk_access != 0) 
> +			*cp++ = ' ';
> +		if ((srp->smk_access & MAY_READ) != 0)
> +			*cp++ = 'r';
> +		if ((srp->smk_access & MAY_WRITE) != 0)
> +			*cp++ = 'w';
> +		if ((srp->smk_access & MAY_EXEC) != 0)
> +			*cp++ = 'x';
> +		if ((srp->smk_access & MAY_APPEND) != 0)
> +			*cp++ = 'a';
> +		*cp++ = '\n';
> +	}
> +	*cp++ = '__PLACEHOLDER__2_';
> +	realbytes = strlen(result);
> +
> +	bytes = simple_read_from_buffer(buf, count, ppos, result, realbytes);
> +	
> +	kfree(result);
> +
> +	return bytes;
> +}
> +
> +/**
> + * smk_set_access - add a rule to the rule list
> + * @srp: the new rule to add
> + *
> + * Looks through the current subject/object/access list for
> + * the subject/object pair and replaces the access that was
> + * there. If the pair isn't found add it with the specified
> + * access.
> + */
> +static void smk_set_access(struct smack_rule *srp)
> +{
> +	struct smk_list_entry *sp;
> +	struct smk_list_entry *newp;
> +
> +	mutex_lock(&smack_list_lock);
> +
> +	for (sp = smack_list; sp != NULL; sp = sp->smk_next)
> +		if (sp->smk_rule.smk_subject == srp->smk_subject &&
> +		    sp->smk_rule.smk_object == srp->smk_object) {
> +			sp->smk_rule.smk_access = srp->smk_access;
> +			break;
> +		}
> +
> +	if (sp == NULL) {
> +		newp = kzalloc(sizeof(struct smk_list_entry), GFP_KERNEL);
> +		newp->smk_rule = *srp;
> +		newp->smk_next = smack_list;
> +		smack_list = newp;
> +		smack_list_count++;
> +	}
> +
> +	mutex_unlock(&smack_list_lock);
> +
> +	return;
> +}
> +
> +
> +/**
> + * smk_write_load - write() for /smack/load
> + * @filp: file pointer, not actually used
> + * @buf: where to get the data from
> + * @count: bytes sent
> + * @ppos: where to start
> + *
> + * Returns number of bytes written or error code, as appropriate
> + */
> +static ssize_t smk_write_load(struct file *file, const char __user *buf,
> +			      size_t count, loff_t *ppos)
> +{
> +	struct smack_rule rule;
> +	ssize_t rc = count;
> +	char *data = NULL;
> +	char subjectstr[SMK_LABELLEN];
> +	char objectstr[SMK_LABELLEN];
> +	char modestr[8];
> +	char *cp;
> +
> +
> +	if (!capable(CAP_MAC_OVERRIDE))
> +		return -EPERM;
> +	/*
> +	 * No partial writes.
> +	 */
> +	if (*ppos != 0)
> +		return -EINVAL;
> +
> +	/*
> +	 * 80 characters per line ought to be enough.
> +	 */
> +	if (count > SMACK_LIST_MAX * 80)
> +		return -ENOMEM;
> +
> +	data = kzalloc(count + 1, GFP_KERNEL);
> +	if (data == NULL)
> +		return -ENOMEM;
> +
> +	if (copy_from_user(data, buf, count) != 0) {
> +		kfree(data);
> +		return -EFAULT;
> +	}
> +
> +	*(data + count) = '__PLACEHOLDER__2_';
> +
> +	for (cp = data - 1; cp != NULL; cp = strchr(cp + 1, '\n')) {
> +		if (*++cp == '__PLACEHOLDER__2_')
> +			break;
> +		if (sscanf(cp, "%23s %23s %7s\n", subjectstr, objectstr,
> +			   modestr) != 3) {
> +			printk("%s:%d bad scan\n", __func__, __LINE__);
> +			break;
> +		}
> +		rule.smk_subject = smk_import(subjectstr, 0);
> +		if (rule.smk_subject == NULL)
> +			break;
> +		rule.smk_object = smk_import(objectstr, 0);
> +		if (rule.smk_object == NULL)
> +			break;
> +		rule.smk_access = 0;
> +		if (strpbrk(modestr, "rR") != NULL)
> +			rule.smk_access |= MAY_READ;
> +		if (strpbrk(modestr, "wW") != NULL)
> +			rule.smk_access |= MAY_WRITE;
> +		if (strpbrk(modestr, "xX") != NULL)
> +			rule.smk_access |= MAY_EXEC;
> +		if (strpbrk(modestr, "aA") != NULL)
> +			rule.smk_access |= MAY_APPEND;
> +		smk_set_access(&rule);
> +		printk("%s:%d rule %s %s 0x%x\n", __func__, __LINE__,
> +			(char *)rule.smk_subject, (char *)rule.smk_object,
> +			rule.smk_access);

Are you sure this isn't something you'd like to really audit?

(Sorry if that's been asked before)

quoted text
> +	}
> +
> +	kfree(data);
> +	return rc;
> +}
> +
> +static const struct file_operations smk_load_ops = {
> +	.read		= smk_read_load,
> +	.write		= smk_write_load,
> +};
> +
> +/**
> + * smk_digit - return a pointer to the next digit
> + * @cp: where to start
> + *
> + * Returns a pointer to the next digit in the string, or NULL
> + */
> +static inline char *smk_digit(const char *cp)
> +{
> +	return strpbrk(cp, "0123456789");
> +}
> +
> +static unsigned int smk_cipso_written;
> +
> +/**
> + * smk_cipso_doi - initialize the CIPSO domain
> + *
> + * This code reaches too deeply into netlabel internals
> + * for comfort, however there is no netlabel KAPI that
> + * allows for kernel based initialization of a CIPSO DOI.
> + * Until Paul and Casey can work out an appropriate
> + * interface Smack will do it this way.
> + */
> +void smk_cipso_doi(void)
> +{
> +	int rc;
> +	struct cipso_v4_doi *doip;
> +	struct netlbl_dom_map *ndmp;
> +	struct netlbl_audit audit_info;
> +
> +	doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL);
> +	if (doip == NULL)
> +		panic("smack:  Failed to initialize cipso DOI.\n");
> +	doip->map.std = NULL;
> +
> +	ndmp = kmalloc(sizeof(struct netlbl_dom_map), GFP_KERNEL);
> +	if (ndmp == NULL)
> +		panic("smack:  Failed to initialize cipso ndmp.\n");
> +
> +	doip->doi = smk_cipso_doi_value;
> +	doip->type = CIPSO_V4_MAP_PASS;
> +	doip->tags[0] = CIPSO_V4_TAG_RBITMAP;
> +	for (rc = 1; rc < CIPSO_V4_TAG_MAXCNT; rc++)
> +		doip->tags[rc] = CIPSO_V4_TAG_INVALID;
> +
> +	rc = cipso_v4_doi_add(doip);
> +	if (rc != 0)
> +		printk("%s:%d add doi rc = %d\n", __func__, __LINE__, rc);
> +
> +	ndmp->domain = NULL;
> +	ndmp->type = NETLBL_NLTYPE_CIPSOV4;
> +	ndmp->type_def.cipsov4 = doip;
> +
> +	rc = netlbl_domhsh_remove_default(&audit_info);
> +	if (rc != 0)
> +		printk("%s:%d remove rc = %d\n", __func__, __LINE__, rc);
> +
> +	rc = netlbl_domhsh_add_default(ndmp, &audit_info);
> +	if (rc != 0)
> +		printk("%s:%d add rc = %d\n", __func__, __LINE__, rc);
> +}
> +
> +/**
> + * smk_read_cipso - read() for /smack/cipso
> + * @filp: file pointer, not actually used
> + * @buf: where to put the result
> + * @count: maximum to send along
> + * @ppos: where to start
> + *
> + * Returns number of bytes read or error code, as appropriate
> + *
> + * label level[/cat[,cat]]
> + */
> +static ssize_t smk_read_cipso(struct file *filp, char __user *buf,
> +			      size_t count, loff_t *ppos)
> +{
> +	struct smack_known *skp;
> +	struct smack_cipso *scp;
> +	ssize_t bytes;
> +	char sep;
> +	char *result;
> +	char *cp;
> +	char *cbp;
> +	int realbytes = 0;
> +	int cat = -1;
> +	int i;
> +	unsigned char m;
> +
> +	if (smk_cipso_written == 0)
> +		return 0;
> +
> +	result = kzalloc(smk_cipso_written, GFP_KERNEL);
> +	if (result == NULL)
> +		return -ENOMEM;
> +	cp = result;
> +
> +	for (skp = smack_known; skp != NULL; skp = skp->smk_next) {
> +		if (skp->smk_cipso == NULL)
> +			continue;
> +		scp = skp->smk_cipso;
> +		cp += sprintf(cp, "%-8s %3d",
> +			(char *)&skp->smk_known, scp->smk_level);
> +		cat = 1;
> +		sep = '/';
> +		cbp = scp->smk_catset;
> +		for (i = 0; i < SMK_LABELLEN; i++) {
> +			for (m = 0x80; m != 0; m >>= 1) {
> +				if ((m & cbp[i]) != 0) {
> +					cp += sprintf(cp, "%c%d", sep, cat);
> +					sep = ',';
> +				}
> +				cat++;
> +			}
> +		}
> +		*cp++ = '\n';
> +	}
> +	*cp++ = '__PLACEHOLDER__3_';
> +	realbytes = strlen(result);
> +
> +	bytes = simple_read_from_buffer(buf, count, ppos, result, realbytes);
> +	
> +	kfree(result);
> +
> +	return bytes;
> +}
> +
> +/**
> + * smk_write_cipso - write() for /smack/cipso
> + * @filp: file pointer, not actually used
> + * @buf: where to get the data from
> + * @count: bytes sent
> + * @ppos: where to start
> + *
> + * Returns number of bytes written or error code, as appropriate
> + */
> +static ssize_t smk_write_cipso(struct file *file, const char __user *buf,
> +			       size_t count, loff_t *ppos)
> +{
> +	struct smack_known *skp;
> +	struct smack_cipso *scp;
> +	char *mapsmack;
> +	char mapcatset[SMK_LABELLEN];
> +	int maplevel;
> +	ssize_t rc = count;
> +	char *data = NULL;
> +	char *cp;
> +	char *eolp;
> +	char *linep;
> +	int cat;
> +	int i;
> +
> +	if (!capable(CAP_MAC_OVERRIDE))
> +		return -EPERM;
> +	/*
> +	 * No partial writes.
> +	 */
> +	if (*ppos != 0)
> +		return -EINVAL;
> +	/*
> +	 * 80 characters per line ought to be enough.
> +	 */
> +	if (count > SMACK_LIST_MAX * 80)
> +		return -ENOMEM;
> +
> +	data = kzalloc(count + 1, GFP_KERNEL);
> +	if (data == NULL)
> +		return -ENOMEM;
> +
> +	if (copy_from_user(data, buf, count) != 0) {
> +		kfree(data);
> +		return -EFAULT;
> +	}
> +
> +	*(data + count) = '__PLACEHOLDER__3_';
> +	smk_cipso_written += count;
> +
> +	for (eolp = strchr(data, '\n'), linep = data;
> +		eolp != NULL && rc >= 0;
> +		linep = eolp + 1, eolp = strchr(linep, '\n')) {
> +
> +		if (eolp == linep)
> +			continue;
> +		*eolp = '__PLACEHOLDER__3_';
> +		memset(mapcatset, '__PLACEHOLDER__3_', SMK_LABELLEN);
> +
> +		skp = smk_import_entry(linep, 0);
> +		if (skp == NULL)
> +			continue;
> +		mapsmack = skp->smk_known;
> +
> +		cp = smk_digit(linep + strlen((char *)mapsmack));
> +		if (cp == NULL)
> +			continue;
> +
> +		i = sscanf(cp, "%d", &maplevel);
> +		if (i != 1)
> +			continue;
> +
> +		cp = strchr(cp, '/');
> +		if (cp != NULL) {
> +			cp = smk_digit(cp);
> +			if (cp == NULL)
> +				continue;
> +
> +			do {
> +				i = sscanf(cp, "%d", &cat);
> +				if (i != 1)
> +					break;
> +				if (cat > SMACK_CIPSO_MAXCAT) {
> +					i = 0;
> +					break;
> +				}
> +				smack_catset_bit(cat, mapcatset);
> +
> +				cp = strchr(cp, ',');
> +				if (cp != NULL)
> +					cp = smk_digit(cp);
> +			} while (cp != NULL);
> +		}
> +
> +		if (i != 1)
> +			continue;
> +
> +
> +		if (skp->smk_cipso == NULL) {
> +			scp = kzalloc(sizeof(struct smack_cipso), GFP_KERNEL);
> +			if (scp == NULL) {
> +				rc = -ENOMEM;
> +				break;
> +			}
> +		} else
> +			scp = NULL;
> +
> +		spin_lock_bh(&skp->smk_cipsolock);
> +		if (skp->smk_cipso == NULL) {
> +			skp->smk_cipso = scp;
> +			scp = NULL;
> +		}
> +		skp->smk_cipso->smk_level = maplevel;
> +		memcpy(skp->smk_cipso->smk_catset, mapcatset, SMK_MAXLEN);
> +		spin_unlock_bh(&skp->smk_cipsolock);
> +
> +		/*
> +		 * The only way this could be true is for there
> +		 * to have been two attempts to update the cipso
> +		 * list at the same time. One of the two will have
> +		 * won cleanly, but there remains cleanup to do.
> +		 */
> +		if (scp != NULL) {
> +			printk(KERN_WARNING "%s: CIPSO collision for \"%s\"\n",
> +				__func__, skp->smk_known);
> +			kfree(scp);
> +		}
> +		/*
> +		 * Add this to ensure that there are
> +		 * enough bytes for the regurgitation
> +		 */
> +		smk_cipso_written += SMK_LABELLEN;
> +	}
> +
> +	kfree(data);
> +	return rc;
> +}
> +
> +static const struct file_operations smk_cipso_ops = {
> +	.read		= smk_read_cipso,
> +	.write		= smk_write_cipso,
> +};
> +
> +/**
> + * smk_read_doi - read() for /smack/doi
> + * @filp: file pointer, not actually used
> + * @buf: where to put the result
> + * @count: maximum to send along
> + * @ppos: where to start
> + *
> + * Returns number of bytes read or error code, as appropriate
> + */
> +static ssize_t smk_read_doi(struct file *filp, char __user *buf,
> +			        size_t count, loff_t *ppos)
> +{
> +	char temp[80];
> +	ssize_t rc;
> +
> +	if (*ppos != 0)
> +		return 0;
> +
> +	sprintf(temp, "%d", smk_cipso_doi_value);
> +	rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
> +
> +	return rc;
> +}
> +
> +/**
> + * smk_write_doi - write() for /smack/doi
> + * @filp: file pointer, not actually used
> + * @buf: where to get the data from
> + * @count: bytes sent
> + * @ppos: where to start
> + *
> + * Returns number of bytes written or error code, as appropriate
> + */
> +static ssize_t smk_write_doi(struct file *file, const char __user *buf,
> +			         size_t count, loff_t *ppos)
> +{
> +	char temp[80];
> +	int i;
> +
> +	if (!capable(CAP_MAC_OVERRIDE))
> +		return -EPERM;
> +
> +	if (count > sizeof(temp))
> +		return -EINVAL;
> +
> +	if (copy_from_user(temp, buf, count) != 0)
> +		return -EFAULT;
> +
> +	if (sscanf(temp, "%d", &i) != 1)
> +		return -EINVAL;
> +
> +	smk_cipso_doi_value = i;
> +
> +	return count;
> +}
> +
> +static const struct file_operations smk_doi_ops = {
> +	.read		= smk_read_doi,
> +	.write		= smk_write_doi,
> +};
> +
> +/**
> + * smk_read_direct - read() for /smack/direct
> + * @filp: file pointer, not actually used
> + * @buf: where to put the result
> + * @count: maximum to send along
> + * @ppos: where to start
> + *
> + * Returns number of bytes read or error code, as appropriate
> + */
> +static ssize_t smk_read_direct(struct file *filp, char __user *buf,
> +			        size_t count, loff_t *ppos)
> +{
> +	char temp[80];
> +	ssize_t rc;
> +
> +	if (*ppos != 0)
> +		return 0;
> +
> +	sprintf(temp, "%d", smack_cipso_direct);
> +	rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp));
> +
> +	return rc;
> +}
> +
> +/**
> + * smk_write_direct - write() for /smack/direct
> + * @filp: file pointer, not actually used
> + * @buf: where to get the data from
> + * @count: bytes sent
> + * @ppos: where to start
> + *
> + * Returns number of bytes written or error code, as appropriate
> + */
> +static ssize_t smk_write_direct(struct file *file, const char __user *buf,
> +			         size_t count, loff_t *ppos)
> +{
> +	char temp[80];
> +	int i;
> +
> +	if (!capable(CAP_MAC_OVERRIDE))
> +		return -EPERM;
> +
> +	if (count > sizeof(temp))
> +		return -EINVAL;
> +
> +	if (copy_from_user(temp, buf, count) != 0)
> +		return -EFAULT;
> +
> +	if (sscanf(temp, "%d", &i) != 1)
> +		return -EINVAL;
> +
> +	smack_cipso_direct = i;
> +
> +	return count;
> +}
> +
> +static const struct file_operations smk_direct_ops = {
> +	.read		= smk_read_direct,
> +	.write		= smk_write_direct,
> +};
> +
> +/**
> + * smk_read_ambient - read() for /smack/ambient
> + * @filp: file pointer, not actually used
> + * @buf: where to put the result
> + * @count: maximum to send along
> + * @ppos: where to start
> + *
> + * Returns number of bytes read or error code, as appropriate
> + */
> +static ssize_t smk_read_ambient(struct file *filp, char __user *buf,
> +			        size_t count, loff_t *ppos)
> +{
> +	ssize_t rc;
> +	int asize = strlen(smack_net_ambient) + 1;
> +
> +	if (count < asize)
> +		return -EINVAL;
> +
> +	if (*ppos != 0)
> +		return 0;
> +
> +	rc = simple_read_from_buffer(buf,count,ppos,smack_net_ambient,asize);
> +
> +	return rc;
> +}
> +
> +/**
> + * smk_write_ambient - write() for /smack/ambient
> + * @filp: file pointer, not actually used
> + * @buf: where to get the data from
> + * @count: bytes sent
> + * @ppos: where to start
> + *
> + * Returns number of bytes written or error code, as appropriate
> + */
> +static ssize_t smk_write_ambient(struct file *file, const char __user *buf,
> +			         size_t count, loff_t *ppos)
> +{
> +	char in[SMK_LABELLEN];
> +	char *smack;
> +
> +	if (!capable(CAP_MAC_OVERRIDE))
> +		return -EPERM;
> +
> +	if (count >= SMK_LABELLEN)
> +		return -EINVAL;
> +
> +	if (copy_from_user(in, buf, count) != 0)
> +		return -EFAULT;
> +
> +	smack = smk_import(in, count);
> +	if (smack == NULL)
> +		return -EINVAL;
> +	/*
> +	 * Better check to be sure this is OK.
> +	 */
> +	smack_net_ambient = smack;
> +
> +	return count;
> +}
> +
> +static const struct file_operations smk_ambient_ops = {
> +	.read		= smk_read_ambient,
> +	.write		= smk_write_ambient,
> +};
> +
> +struct option_names {
> +	int	o_number;
> +	char	*o_name;
> +	char	*o_alias;
> +};
> +
> +static struct option_names netlbl_choices[] = {
> +	{ NETLBL_NLTYPE_RIPSO,
> +		NETLBL_NLTYPE_RIPSO_NAME,	"ripso" },
> +	{ NETLBL_NLTYPE_CIPSOV4,
> +		NETLBL_NLTYPE_CIPSOV4_NAME,	"cipsov4" },
> +	{ NETLBL_NLTYPE_CIPSOV4,
> +		NETLBL_NLTYPE_CIPSOV4_NAME,	"cipso" },
> +	{ NETLBL_NLTYPE_CIPSOV6,
> +		NETLBL_NLTYPE_CIPSOV6_NAME,	"cipsov6" },
> +	{ NETLBL_NLTYPE_UNLABELED,
> +		NETLBL_NLTYPE_UNLABELED_NAME,	"unlabeled" },
> +};
> +
> +/**
> + * smk_read_nltype - read() for /smack/nltype
> + * @filp: file pointer, not actually used
> + * @buf: where to put the result
> + * @count: maximum to send along
> + * @ppos: where to start
> + *
> + * Returns number of bytes read or error code, as appropriate
> + */
> +static ssize_t smk_read_nltype(struct file *filp, char __user *buf,
> +			       size_t count, loff_t *ppos)
> +{
> +	char bound[40];
> +	ssize_t rc;
> +	int i;
> +
> +	if (count < SMK_LABELLEN)
> +		return -EINVAL;
> +
> +	if (*ppos != 0)
> +		return 0;
> +
> +	sprintf(bound, "unknown");
> +
> +	for (i = 0; i < ARRAY_SIZE(netlbl_choices); i++)
> +		if (smack_net_nltype == netlbl_choices[i].o_number) {
> +			sprintf(bound, "%s", netlbl_choices[i].o_name);
> +			break;
> +		}
> +
> +	rc = simple_read_from_buffer(buf, count, ppos, bound, strlen(bound));
> +
> +	return rc;
> +}
> +
> +/**
> + * smk_write_nltype - write() for /smack/nltype
> + * @filp: file pointer, not actually used
> + * @buf: where to get the data from
> + * @count: bytes sent
> + * @ppos: where to start
> + *
> + * Returns number of bytes written or error code, as appropriate
> + */
> +static ssize_t smk_write_nltype(struct file *file, const char __user *buf,
> +			        size_t count, loff_t *ppos)
> +{
> +	char bound[40];
> +	char *cp;
> +	int i;
> +
> +	if (!capable(CAP_MAC_OVERRIDE))
> +		return -EPERM;
> +
> +	if (count >= 40)
> +		return -EINVAL;
> +
> +	if (copy_from_user(bound, buf, count) != 0)
> +		return -EFAULT;
> +
> +	bound[count] = '__PLACEHOLDER__3_';
> +	cp = strchr(bound, ' ');
> +	if (cp != NULL)
> +		*cp = '__PLACEHOLDER__3_';
> +	cp = strchr(bound, '\n');
> +	if (cp != NULL)
> +		*cp = '__PLACEHOLDER__3_';
> +
> +	for (i = 0; i < ARRAY_SIZE(netlbl_choices); i++)
> +		if (strcmp(bound, netlbl_choices[i].o_name) == 0 ||
> +		    strcmp(bound, netlbl_choices[i].o_alias) == 0) {
> +			smack_net_nltype = netlbl_choices[i].o_number;
> +			return count;
> +		}
> +	/*
> +	 * Not a valid choice.
> +	 */
> +	return -EINVAL;
> +}
> +
> +static const struct file_operations smk_nltype_ops = {
> +	.read		= smk_read_nltype,
> +	.write		= smk_write_nltype,
> +};
> +
> +/*
> + * mapping for symlinks
> + */
> +#define SMK_TMPPATH_SIZE        1024
> +#define SMK_TMPPATH_ROOT        "/moldy/"
> +
> +struct smk_link {
> +	struct smk_link	*sl_next;
> +	int		sl_inum;
> +	char		sl_name[SMK_TMPPATH_SIZE];
> +	char		sl_target[SMK_TMPPATH_SIZE];
> +};
> +
> +static struct super_block *smk_sb = NULL;
> +static struct smk_link *smk_links = NULL;
> +static int smk_links_count = 0;
> +
> +/**
> + * smackfs_follow_link - follow a smackfs symlink
> + * @dentry: name cache entry
> + * @nd: name entry
> + *
> + * A symlink on smackfs has unusual semantics.
> + *
> + * The Smack value of the task is appended to the link string.
> + * Thus, if a task labeled "Gentoo" does chdir("/smack/tmp")
> + * it will use "/moldy/Gentoo".
> + *
> + * The expected usage is the /tmp is a symlink to /smack/tmp
> + * which is itself a symlink to /moldy. /moldy should have a
> + * directory for each label in use to accomodate the value
> + * appended on the redirection.
> + *
> + * An interesting addition would be a file system that automatically
> + * creates directories as needed, at the appropriate label.
> + */
> +static void *smackfs_follow_link(struct dentry *dentry, struct nameidata *nd)
> +{
> +	char *sp = current->security;
> +	char *cp;
> +	int inum = dentry->d_inode->i_ino;
> +	struct smk_link *slp;
> +
> +	for (slp = smk_links; slp != NULL; slp = slp->sl_next)
> +		if (slp->sl_inum == inum)
> +			break;
> +
> +	if (slp == NULL) {
> +		printk("%s:%d failed\n", __func__, __LINE__);
> +		return NULL;
> +	}
> +	cp = kzalloc(SMK_TMPPATH_SIZE, GFP_KERNEL);
> +	if (cp == NULL)
> +		return NULL;
> +
> +	strcpy(cp, slp->sl_target);
> +	strcat(cp, sp);
> +	nd_set_link(nd, cp);
> +	/*
> +	 * Unlike the readlink below, hang on to the memory allocated
> +	 * because nd_set_link passes it along.
> +	 */
> +	return NULL;
> +}
> +
> +/**
> + * smackfs_readlink - read a smackfs symlink
> + * @dentry: name cache entry
> + * @buffer: where the result goes
> + * @buflen: buffer size
> + *
> + * Returns 0 on success, an error code otherwise
> + *
> + * Supports the same semantics as the follow code.
> + */
> +static int smackfs_readlink(struct dentry *dentry, char __user *buffer,
> +			    int buflen)
> +{
> +	char *csp = current->security;
> +	char *cp;
> +	int len;
> +	int inum = dentry->d_inode->i_ino;
> +	struct smk_link *slp;
> +
> +	for (slp = smk_links; slp != NULL; slp = slp->sl_next)
> +		if (slp->sl_inum == inum)
> +			break;
> +
> +	if (slp == NULL) {
> +		printk("%s:%d failed\n", __func__, __LINE__);
> +		return -EACCES;
> +	}
> +
> +	cp = kzalloc(SMK_TMPPATH_SIZE, GFP_KERNEL);
> +	if (cp == NULL)
> +		return -ENOMEM;
> +
> +	strcpy(cp, slp->sl_target);
> +	strcat(cp, csp);
> +	len = strlen(cp);
> +	len = (len > buflen) ? buflen : len;
> +
> +	if (copy_to_user(buffer, cp, len) != 0)
> +		len = -EFAULT;
> +
> +	kfree(cp);
> +	return len;
> +}
> +
> +/**
> + * smackfs_put_link - free a followed component
> + * @dentry: unused
> + * @nd: name entry
> + * @ptr: unused
> + *
> + * free the buffer used in following the link.
> + */
> +static void smackfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
> +{
> +	kfree(nd_get_link(nd));
> +}
> +
> +static struct inode_operations smackfs_symlink_inode_operations = {
> +	.readlink	= smackfs_readlink,
> +	.follow_link	= smackfs_follow_link,
> +	.put_link	= smackfs_put_link,
> +};
> +
> +/**
> + * smk_add_symlink - follow a smackfs symlink
> + * @name: the name of the synlink
> + * @target: where it points to
> + *
> + * Add a smackfs symlink
> + */
> +static void smk_add_symlink(char *name, char *target)
> +{
> +	static int inum = SMK_TMP;
> +	struct inode *inode;
> +	struct dentry *dentry;
> +	struct smk_link *slp;
> +
> +	for (slp = smk_links; slp != NULL; slp = slp->sl_next) {
> +		if (strcmp(slp->sl_name, name) != 0)
> +			continue;
> +		strcpy(slp->sl_target, target);
> +		return;
> +	}
> +
> +	slp = kzalloc(sizeof(struct smk_link), GFP_KERNEL);
> +	if (slp == NULL)
> +		return;
> +
> +	dentry = d_alloc_name(smk_sb->s_root, name);
> +	if (dentry == NULL) {
> +		printk("%s:%d link dentry failed\n", __func__, __LINE__);
> +		return;
> +	}
> +
> +	inode = new_inode(smk_sb);
> +	if (inode == NULL) {
> +		printk("%s:%d link inode failed\n", __func__, __LINE__);
> +		return;
> +	}
> +
> +	inode->i_mode = S_IFLNK | S_IRWXUGO;
> +	inode->i_uid = 0;
> +	inode->i_gid = 0;
> +	inode->i_blocks = 0;
> +	inode->i_atime = CURRENT_TIME;
> +	inode->i_mtime = inode->i_atime;
> +	inode->i_ctime = inode->i_atime;
> +	inode->i_ino = inum++;
> +	inode->i_op = &smackfs_symlink_inode_operations;
> +	d_add(dentry, inode);
> +
> +	strcpy(slp->sl_name, name);
> +	strcpy(slp->sl_target, target);
> +	slp->sl_inum = inode->i_ino;
> +	slp->sl_next = smk_links;
> +	smk_links = slp;
> +	smk_links_count++;
> +
> +	return;
> +}
> +
> +/**
> + * smk_read_links - read() for /smack/links
> + * @filp: file pointer, not actually used
> + * @buf: where to put the result
> + * @count: maximum to send along
> + * @ppos: where to start
> + *
> + * Returns number of bytes read or error code, as appropriate
> + */
> +static ssize_t smk_read_links(struct file *filp, char __user *buf,
> +			     size_t count, loff_t *ppos)
> +{
> +	ssize_t bytes = sizeof(struct smk_link) * smk_links_count;
> +	struct smk_link *slp;
> +	char *result;
> +	char *cp;
> +	
> +
> +	result = kzalloc(bytes, GFP_KERNEL);
> +	if (result == NULL)
> +		return -ENOMEM;
> +	*result = '__PLACEHOLDER__3_';
> +
> +	for (slp = smk_links, cp = result; slp != NULL; slp = slp->sl_next)
> +		cp += sprintf(cp, "%s %s\n", slp->sl_name, slp->sl_target);
> +
> +	bytes = simple_read_from_buffer(buf,count,ppos,result,strlen(result));
> +	
> +	kfree(result);
> +
> +	return bytes;
> +}
> +
> +/**
> + * smk_write_links - write() for /smack/links
> + * @filp: file pointer, not actually used
> + * @buf: where to get the data from
> + * @count: bytes sent
> + * @ppos: where to start
> + *
> + * Returns number of bytes written or error code, as appropriate
> + *
> + * This might be better done using "real" symlink creation.
> + */
> +static ssize_t smk_write_links(struct file *file, const char __user *buf,
> +			      size_t count, loff_t *ppos)
> +{
> +	ssize_t rc = count;
> +	char *data;
> +	char *cp;
> +	char name[SMK_TMPPATH_SIZE];
> +	char target[SMK_TMPPATH_SIZE];
> +
> +	/*
> +	 * No partial writes.
> +	 */
> +	if (*ppos != 0)
> +		return -EINVAL;
> +	/*
> +	 * 80 characters per line ought to be enough.
> +	 */
> +	if (count > SMACK_LIST_MAX * 80)
> +		return -ENOMEM;
> +
> +	data = kzalloc(count + 1, GFP_KERNEL);
> +	if (data == NULL)
> +		return -ENOMEM;
> +
> +	if (copy_from_user(data, buf, count) != 0) {
> +		kfree(data);
> +		return -EFAULT;
> +	}
> +
> +	data[count] = '__PLACEHOLDER__3_';
> +
> +	for (cp = data - 1; cp != NULL; cp = strchr(cp + 1, '\n')) {
> +		if (*++cp == '__PLACEHOLDER__3_')
> +			break;
> +		if (sscanf(cp, "%14s %30s\n", name, target) != 2) {
> +			printk("%s:%d bad scan\n",
> +				__func__, __LINE__);
> +			break;
> +		}
> +		smk_add_symlink(name, target);
> +		printk("%s:%d add %s -> %s\n",
> +			__func__, __LINE__, name, target);
> +	}
> +
> +	kfree(data);
> +	return rc;
> +}
> +
> +static const struct file_operations smk_links_ops = {
> +	.read		= smk_read_links,
> +	.write		= smk_write_links,
> +};
> +
> +/**
> + * smk_fill_super - fill the /smackfs superblock
> + * @sb: the empty superblock
> + * @data: unused
> + * @silent: unused
> + *
> + * Fill in the well known entries for /smack and set up for
> + * symlinks
> + *
> + * Returns 0 on success, an error code on failure
> + */
> +static int smk_fill_super(struct super_block *sb, void * data, int silent)
> +{
> +	int rc;
> +	struct inode *root_inode;
> +
> +	static struct tree_descr smack_files[] = {
> +		[SMK_LOAD]	= {"load", &smk_load_ops, S_IRUGO|S_IWUSR},
> +		[SMK_LINKS]	= {"links", &smk_links_ops, S_IRUGO|S_IWUSR},
> +		[SMK_CIPSO]	= {"cipso", &smk_cipso_ops, S_IRUGO|S_IWUSR},
> +		[SMK_DOI]	= {"doi", &smk_doi_ops, S_IRUGO|S_IWUSR},
> +		[SMK_DIRECT]	= {"direct", &smk_direct_ops, S_IRUGO|S_IWUSR},
> +		[SMK_AMBIENT]	= {"ambient", &smk_ambient_ops,S_IRUGO|S_IWUSR},
> +		[SMK_NLTYPE]	= {"nltype", &smk_nltype_ops, S_IRUGO|S_IWUSR},
> +		/* last one */ {""}
> +	};
> +
> +	/*
> +	 * There will be only one smackfs. Casey says so.
> +	 */
> +	smk_sb = sb;
> +
> +	rc = simple_fill_super(sb, SMACK_MAGIC, smack_files);
> +	if (rc != 0) {
> +		printk(KERN_ERR "%s failed %d while creating inodes\n",
> +			__func__, rc);
> +		return rc;
> +	}
> +
> +	root_inode = sb->s_root->d_inode;
> +	root_inode->i_security = new_inode_smack(smack_known_floor.smk_known);
> +
> +	/*
> +	 * Create a directory for /smack/tmp
> +	 */
> +	smk_add_symlink("tmp", SMK_TMPPATH_ROOT);
> +
> +	return 0;
> +}
> +
> +/**
> + * smk_get_sb - get the smackfs superblock
> + * @fs_type: passed along without comment
> + * @flags: passed along without comment
> + * @dev_name: passed along without comment
> + * @data: passed along without comment
> + * @mnt: passed along without comment
> + *
> + * Just passes everything along.
> + *
> + * Returns what the lower level code does.
> + */
> +static int smk_get_sb(struct file_system_type *fs_type,
> +		      int flags, const char *dev_name, void *data,
> +		      struct vfsmount *mnt)
> +{
> +	return get_sb_single(fs_type, flags, data, smk_fill_super, mnt);
> +}
> +
> +static struct file_system_type smk_fs_type = {
> +	.name		= "smackfs",
> +	.get_sb		= smk_get_sb,
> +	.kill_sb	= kill_litter_super,
> +};
> +
> +static struct vfsmount *smackfs_mount;
> +
> +/**
> + * init_smk_fs - get the smackfs superblock
> + *
> + * register the smackfs
> + *
> + * Returns 0 unless the registration fails.
> + */
> +static int __init init_smk_fs(void)
> +{
> +	int err;
> +
> +	err = register_filesystem(&smk_fs_type);
> +	if (!err) {
> +		smackfs_mount = kern_mount(&smk_fs_type);
> +		if (IS_ERR(smackfs_mount)) {
> +			printk(KERN_ERR "smackfs:  could not mount!\n");
> +			err = PTR_ERR(smackfs_mount);
> +			smackfs_mount = NULL;
> +		}
> +	}
> +
> +	return err;
> +}
> +
> +__initcall(init_smk_fs);
> diff -uprN -X linux-2.6.23-rc8-base/Documentation/dontdiff linux-2.6.23-rc8-base/security/smack/smack.h linux-2.6.23-rc8-smack/security/smack/smack.h
> --- linux-2.6.23-rc8-base/security/smack/smack.h	1969-12-31 16:00:00.000000000 -0800
> +++ linux-2.6.23-rc8-smack/security/smack/smack.h	2007-09-25 15:30:38.000000000 -0700
> @@ -0,0 +1,207 @@
> +/*
> + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
> + *
> + *      This program is free software; you can redistribute it and/or modify
> + *      it under the terms of the GNU General Public License as published by
> + *      the Free Software Foundation, version 2.
> + *
> + * Author:
> + *      Casey Schaufler <casey@schaufler-ca.com>
> + *
> + */
> +
> +#ifndef _SECURITY_SMACK_H
> +#define _SECURITY_SMACK_H
> +
> +#include <linux/capability.h>
> +#include <linux/spinlock.h>
> +#include <net/netlabel.h>
> +
> +/*
> + * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is
> + * bigger than can be used, and 24 is the next lower multiple
> + * of 8, and there are too many issues if there isn't space set
> + * aside for the terminating null byte.
> + */
> +#define SMK_MAXLEN	23
> +#define SMK_LABELLEN	(SMK_MAXLEN+1)
> +
> +struct superblock_smack {
> +	char	*smk_root;
> +	char	*smk_floor;
> +	char	*smk_hat;
> +	char	*smk_default;
> +	int	smk_initialized;
> +};
> +
> +struct socket_smack {
> +	char	*smk_out;	/* outbound label */
> +	char	*smk_in;	/* inbound label */
> +	char	smk_packet[SMK_LABELLEN];
> +	int	smk_depth;
> +};
> +
> +/*
> + * Inode smack data
> + */
> +struct inode_smack {
> +	char		*smk_inode;	/* label of the fso */
> +	struct mutex	smk_lock;	/* initialization lock */
> +	int		smk_flags;	/* smack inode flags */
> +};
> +
> +#define	SMK_INODE_INSTANT	0x01	/* inode is instantiated */
> +
> +/*
> + * A label access rule.
> + */
> +struct smack_rule {
> +	char	*smk_subject;
> +	char	*smk_object;
> +	int	smk_access;
> +};
> +
> +/*
> + * An entry in the table of permitted label accesses.
> + */
> +struct smk_list_entry {
> +	struct smk_list_entry	*smk_next;
> +	struct smack_rule	smk_rule;
> +};
> +
> +/*
> + * An entry in the table mapping smack values to
> + * CIPSO level/category-set values.
> + */
> +struct smack_cipso {
> +	int	smk_level;
> +	char	smk_catset[SMK_LABELLEN];
> +};
> +
> +/*
> + * This is the repository for labels seen so that it is
> + * not necessary to keep allocating tiny chuncks of memory
> + * and so that they can be shared.
> + *
> + * Labels are never modified in place. Anytime a label
> + * is imported (e.g. xattrset on a file) the list is checked
> + * for it and it is added if it doesn't exist. The address
> + * is passed out in either case. Entries are added, but
> + * never deleted.
> + *
> + * Since labels are hanging around anyway it doesn't
> + * hurt to maintain a secid for those awkward situations
> + * where kernel components that ought to use LSM independent
> + * interfaces don't. The secid should go away when all of
> + * these components have been repaired.
> + *
> + * If there is a cipso value associated with the label it
> + * gets stored here, too. This will most likely be rare as
> + * the cipso direct mapping in used internally.
> + */
> +struct smack_known {
> +	struct smack_known	*smk_next;
> +	char			smk_known[SMK_LABELLEN];
> +	u32			smk_secid;
> +	struct smack_cipso	*smk_cipso;
> +	spinlock_t		smk_cipsolock;
> +};
> +
> +/*
> + * Mount options
> + */
> +#define SMK_FSDEFAULT	"smackfsdef="
> +#define SMK_FSFLOOR	"smackfsfloor="
> +#define SMK_FSHAT	"smackfshat="
> +#define SMK_FSROOT	"smackfsroot="
> +
> +/*
> + * xattr names
> + */
> +#define XATTR_SMACK_SUFFIX	"SMACK64"
> +#define XATTR_SMACK_IPIN	"SMACK64IPIN"
> +#define XATTR_SMACK_IPOUT	"SMACK64IPOUT"
> +#define XATTR_SMACK_PACKET	"SMACK64PACKET"
> +#define XATTR_NAME_SMACK	XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX
> +
> +/*
> + * smackfs macic number
> + */
> +#define SMACK_MAGIC	0x43415d53 /* "SMAC" */
> +
> +/*
> + * A limit on the number of entries in the lists
> + * makes some of the list administration easier.
> + */
> +#define SMACK_LIST_MAX	10000
> +
> +/*
> + * CIPSO defaults.
> + */
> +#define SMACK_CIPSO_DOI_DEFAULT		3	/* Historical */
> +#define SMACK_CIPSO_DIRECT_DEFAULT	250	/* Arbitrary */
> +#define SMACK_CIPSO_MAXCAT		63	/* Bigger gets harder */
> +
> +/*
> + * Just to make the common cases easier to deal with
> + */
> +#define MAY_ANY		(MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
> +#define MAY_ANYREAD	(MAY_READ | MAY_EXEC)
> +#define MAY_ANYWRITE	(MAY_WRITE | MAY_APPEND)
> +#define MAY_READWRITE	(MAY_READ | MAY_WRITE)
> +#define MAY_NOT		0
> +
> +/*
> + * There are not enough CAP bits available to make this
> + * real, so Casey borrowed the capability that looks to
> + * him like it has the best balance of similarity amd
> + * low use.
> + */
> +#define CAP_MAC_OVERRIDE CAP_LINUX_IMMUTABLE

We're basically inevitably going to be switching to 64-bit caps
"any day now".  Should we just go ahead and do it here?  Now
maybe we should use a less contraversial name than 'mac override'
like 'CAP_MAC_POLICY_ADMIN' :), but I guess CAP_MAC_OVERRIDE
is honest.

(I had started a 64-bit caps patch, but then got stuck trying to
decide whether something needed to be done about
task_capability_lock...)

Well, I guess you wouldn't want to bog down your patch to
that, but would you take your own bit once it was available,
or are you happy just using CAP_LINUX_IMMUTABLE?

quoted text
> +
> +/*
> + * These functions are in smackfs.c
> + */
> +void smk_cipso_doi(void);
> +
> +/*
> + * These functions are in smack_lsm.c
> + */
> +struct inode_smack *new_inode_smack(char *);
> +
> +/*
> + * These functions are in smack_access.c
> + */
> +int smk_access(char *, char *, int);
> +int smk_curacc(char *, u32);
> +int smack_to_cipso(const char *, struct smack_cipso *);
> +void smack_from_cipso(u32, char *, char *);
> +char *smack_from_secid(const u32);
> +char *smk_import(const char *, int);
> +struct smack_known *smk_import_entry(const char *, int);
> +u32 smack_to_secid(const char *);
> +
> +/*
> + * Stricly for CIPSO level manipulation.
> + * Set the category bit number in a smack label sized buffer.
> + */
> +static inline void smack_catset_bit(int cat, char *catsetp)
> +{
> +        char *cp = (char *)catsetp;
> +
> +        if (cat > SMK_LABELLEN * 8)
> +                return;
> +
> +        cp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8);
> +}
> +
> +/*
> + * Present a pointer to the smack label in an inode blob.
> + */
> +static inline char *smk_of_inode(const struct inode *isp)
> +{
> +	struct inode_smack *sip = isp->i_security;
> +	return sip->smk_inode;
> +}
> +
> +#endif  /* _SECURITY_SMACK_H */
> diff -uprN -X linux-2.6.23-rc8-base/Documentation/dontdiff linux-2.6.23-rc8-base/security/smack/smack_lsm.c linux-2.6.23-rc8-smack/security/smack/smack_lsm.c
> --- linux-2.6.23-rc8-base/security/smack/smack_lsm.c	1969-12-31 16:00:00.000000000 -0800
> +++ linux-2.6.23-rc8-smack/security/smack/smack_lsm.c	2007-09-25 15:30:38.000000000 -0700
> @@ -0,0 +1,2685 @@
> +/*
> + *  Simplified MAC Kernel (smack) security module
> + *
> + *  This file contains the smack hook function implementations.
> + *
> + *  Author:
> + *	Casey Schaufler <casey@schaufler-ca.com>
> + *
> + *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
> + *
> + *	This program is free software; you can redistribute it and/or modify
> + *	it under the terms of the GNU General Public License version 2,
> + *      as published by the Free Softwa