As reported by Alan Cox, and verified by Lin Ming, when a user
attempts to add a CIPSO option to a socket using the CIPSO_V4_TAG_LOCAL
tag the kernel dies a terrible death when it attempts to follow a NULL
pointer (the skb argument to cipso_v4_validate() is NULL when called via
the setsockopt() syscall).
This patch fixes this by first checking to ensure that the skb is
non-NULL before using it to find the incoming network interface. In
the unlikely case where the skb is NULL and the user attempts to add
a CIPSO option with the _TAG_LOCAL tag we return an error as this is
not something we want to allow.
A simple reproducer, kindly supplied by Lin Ming, although you must
have the CIPSO DOI #3 configure on the system first or you will be
caught early in cipso_v4_validate():
#include <sys/types.h>
#include <sys/socket.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <string.h>
struct local_tag {
char type;
char length;
char info[4];
};
struct cipso {
char type;
char length;
char doi[4];
struct local_tag local;
};
int main(int argc, char **argv)
{
int sockfd;
struct cipso cipso = {
.type = IPOPT_CIPSO,
.length = sizeof(struct cipso),
.local = {
.type = 128,
.length = sizeof(struct local_tag),
},
};
memset(cipso.doi, 0, 4);
cipso.doi[3] = 3;
sockfd = socket(AF_INET, SOCK_DGRAM, 0);
#define SOL_IP 0
setsockopt(sockfd, SOL_IP, IP_OPTIONS,
&cipso, sizeof(struct cipso));
return 0;
}
CC: Lin Ming <mlin@ss.pku.edu.cn>
Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Because opt_kfree_rcu() just calls kfree(), all call_rcu() uses of it
may be converted to kfree_rcu(). This permits opt_kfree_rcu() to
be eliminated.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: netdev@vger.kernel.org
We dereference doi_def on the line before the NULL check. It has
been this way since 2008. I checked all the callers and doi_def is
always non-NULL here.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We lack proper synchronization to manipulate inet->opt ip_options
Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.
Another thread can change inet->opt pointer and free old one under us.
Use RCU to protect inet->opt (changed to inet->inet_opt).
Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.
We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The patch below updates broken web addresses in the kernel
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Dimitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Acked-by: Ben Pfaff <blp@cs.stanford.edu>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Reviewed-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This patch removes from net/ (but not any netfilter files)
all the unnecessary return; statements that precede the
last closing brace of void functions.
It does not remove the returns that are immediately
preceded by a label as gcc doesn't like that.
Done via:
$ grep -rP --include=*.[ch] -l "return;\n}" net/ | \
xargs perl -i -e 'local $/ ; while (<>) { s/\n[ \t\n]+return;\n}/\n}/g; print; }'
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
There is no reason that cipso_v4_delopt() is not
defined as a static function.
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current NetLabel/SELinux behavior for incoming TCP connections works but
only through a series of happy coincidences that rely on the limited nature of
standard CIPSO (only able to convey MLS attributes) and the write equality
imposed by the SELinux MLS constraints. The problem is that network sockets
created as the result of an incoming TCP connection were not on-the-wire
labeled based on the security attributes of the parent socket but rather based
on the wire label of the remote peer. The issue had to do with how IP options
were managed as part of the network stack and where the LSM hooks were in
relation to the code which set the IP options on these newly created child
sockets. While NetLabel/SELinux did correctly set the socket's on-the-wire
label it was promptly cleared by the network stack and reset based on the IP
options of the remote peer.
This patch, in conjunction with a prior patch that adjusted the LSM hook
locations, works to set the correct on-the-wire label format for new incoming
connections through the security_inet_conn_request() hook. Besides the
correct behavior there are many advantages to this change, the most significant
is that all of the NetLabel socket labeling code in SELinux now lives in hooks
which can return error codes to the core stack which allows us to finally get
ride of the selinux_netlbl_inode_permission() logic which greatly simplfies
the NetLabel/SELinux glue code. In the process of developing this patch I
also ran into a small handful of AF_INET6 cleanliness issues that have been
fixed which should make the code safer and easier to extend in the future.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
The CIPSO protocol engine incorrectly stated that the FIPS-188 specification
could be found in the kernel's Documentation directory. This patch corrects
that by removing the comment and directing users to the FIPS-188 documented
hosted online. For the sake of completeness I've also included a link to the
CIPSO draft specification on the NetLabel website.
Thanks to Randy Dunlap for spotting the error and letting me know.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
Update the NetLabel kernel API to expose the new features added in kernel
releases 2.6.25 and 2.6.28: the static/fallback label functionality and network
address based selectors.
Signed-off-by: Paul Moore <paul.moore@hp.com>
call_rcu() will unconditionally rewrite RCU head anyway.
Applies to
struct neigh_parms
struct neigh_table
struct net
struct cipso_v4_doi
struct in_ifaddr
struct in_device
rt->u.dst
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch accomplishes three minor tasks: add a new tag type for local
labeling, rename the CIPSO_V4_MAP_STD define to CIPSO_V4_MAP_TRANS and
replace some of the CIPSO "magic numbers" with constants from the header
file. The first change allows CIPSO to support full LSM labels/contexts,
not just MLS attributes. The second change brings the mapping names inline
with what userspace is using, compatibility is preserved since we don't
actually change the value. The last change is to aid readability and help
prevent mistakes.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Previous work enabled the use of address based NetLabel selectors, which while
highly useful, brought the potential for additional per-packet overhead when
used. This patch attempts to solve that by applying NetLabel socket labels
when sockets are connect()'d. This should alleviate the per-packet NetLabel
labeling for all connected sockets (yes, it even works for connected DGRAM
sockets).
Signed-off-by: Paul Moore <paul.moore@hp.com>
Reviewed-by: James Morris <jmorris@namei.org>
This patch builds upon the new NetLabel address selector functionality by
providing the NetLabel KAPI and CIPSO engine support needed to enable the
new packet-based labeling. The only new addition to the NetLabel KAPI at
this point is shown below:
* int netlbl_skbuff_setattr(skb, family, secattr)
... and is designed to be called from a Netfilter hook after the packet's
IP header has been populated such as in the FORWARD or LOCAL_OUT hooks.
This patch also provides the necessary SELinux hooks to support this new
functionality. Smack support is not currently included due to uncertainty
regarding the permissions needed to expand the Smack network access controls.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Reviewed-by: James Morris <jmorris@namei.org>
NetLabel has always had a list of backpointers in the CIPSO DOI definition
structure which pointed to the NetLabel LSM domain mapping structures which
referenced the CIPSO DOI struct. The rationale for this was that when an
administrator removed a CIPSO DOI from the system all of the associated
NetLabel LSM domain mappings should be removed as well; a list of
backpointers made this a simple operation.
Unfortunately, while the backpointers did make the removal easier they were
a bit of a mess from an implementation point of view which was making
further development difficult. Since the removal of a CIPSO DOI is a
realtively rare event it seems to make sense to remove this backpointer
list as the optimization was hurting us more then it was helping. However,
we still need to be able to track when a CIPSO DOI definition is being used
so replace the backpointer list with a reference count. In order to
preserve the current functionality of removing the associated LSM domain
mappings when a CIPSO DOI is removed we walk the LSM domain mapping table,
removing the relevant entries.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Reviewed-by: James Morris <jmorris@namei.org>
The cipso_v4_cache is allocated to contain CIPSO_V4_CACHE_BUCKETS
buckets. The CIPSO_V4_CACHE_BUCKETS = 1 << CIPSO_V4_CACHE_BUCKETBITS,
where CIPSO_V4_CACHE_BUCKETBITS = 7.
The bucket-selection function for this hash is calculated like this:
bkt = hash & (CIPSO_V4_CACHE_BUCKETBITS - 1);
^^^
i.e. picking only 4 buckets of possible 128 :)
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ip_options->is_data is assigned only and never checked. The structure is
not a part of kernel interface to the userspace. So, it is safe to remove
this field.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new set of configuration functions to the NetLabel/LSM API so that
LSMs can perform their own configuration of the NetLabel subsystem without
relying on assistance from userspace.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds support to the NetLabel LSM secattr struct for a secid token
and a type field, paving the way for full LSM/SELinux context support and
"static" or "fallback" labels. In addition, this patch adds a fair amount
of documentation to the core NetLabel structures used as part of the
NetLabel kernel API.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
single list_head variable initialized with LIST_HEAD_INIT could almost
always can be replaced with LIST_HEAD declaration, this shrinks the code
and looks better.
Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This fixes some awkward, and perhaps even problematic, RCU lock usage in the
NetLabel code as well as some other related trivial cleanups found when
looking through the RCU locking. Most of the changes involve removing the
redundant RCU read locks wrapping spinlocks in the case of a RCU writer.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bulk of the CIPSO option parsing/processing in the cipso_v4_sock_getattr()
and cipso_v4_skb_getattr() functions are identical, the only real difference
being where the functions obtain the CIPSO option itself. This patch creates
a new function, cipso_v4_getattr(), which contains the common CIPSO option
parsing/processing code and modifies the existing functions to call this new
helper function.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv4 options are not very well aligned within the packet and the
format of a CIPSO option is even worse. The result is that the CIPSO
engine in the kernel does a few unaligned accesses when parsing and
validating incoming packets with CIPSO options attached which generate
error messages on certain alignment sensitive platforms. This patch
fixes this by marking these unaligned accesses with the
get_unaliagned() macro.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current NetLabel code has some redundant APIs which allow both
"struct socket" and "struct sock" types to be used; this may have made
sense at some point but it is wasteful now. Remove the functions that
operate on sockets and convert the callers. Not only does this make
the code smaller and more consistent but it pushes the locking burden
up to the caller which can be more intelligent about the locks. Also,
perform the same conversion (socket to sock) on the SELinux/NetLabel
glue code where it make sense.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6:
selinux: preserve boolean values across policy reloads
selinux: change numbering of boolean directory inodes in selinuxfs
selinux: remove unused enumeration constant from selinuxfs
selinux: explicitly number all selinuxfs inodes
selinux: export initial SID contexts via selinuxfs
selinux: remove userland security class and permission definitions
SELinux: move security_skb_extlbl_sid() out of the security server
MAINTAINERS: update selinux entry
SELinux: rename selinux_netlabel.h to netlabel.h
SELinux: extract the NetLabel SELinux support from the security server
NetLabel: convert a BUG_ON in the CIPSO code to a runtime check
NetLabel: cleanup and document CIPSO constants
This patch changes a BUG_ON in the CIPSO code to a runtime check. It should
also increase the readability of the code as it replaces an unexplained
constant with a well defined macro.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
This patch collects all of the CIPSO constants and puts them in one place; it
also documents each value explaining how the value is derived.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
Add whitespace around keywords.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 484b366932 added support for the CIPSO
ranged categories tag. However, it appears that I made a mistake when rebasing
then patch to the latest upstream sources for submission and dropped the part
of the patch that actually parses the tag on incoming packets. This patch
fixes this mistake by adding the required function call to the
cipso_v4_skbuff_getattr() function.
I've run this patch over the weekend and have not noticed any problems.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current CIPSO engine has a problem where it does not verify that
the given sensitivity level has a valid CIPSO mapping when the "std"
CIPSO DOI type is used. The end result is that bad packets are sent
on the wire which should have never been sent in the first place.
This patch corrects this problem by verifying the sensitivity level
mapping similar to what is done with the category mapping. This patch
also changes the returned error code in this case to -EPERM to better
match what the category mapping verification code returns.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for the ranged tag (tag type #5) to the CIPSOv4 protocol.
The ranged tag allows for seven, or eight if zero is the lowest category,
category ranges to be specified in a CIPSO option. Each range is specified by
two unsigned 16 bit fields, each with a maximum value of 65534. The two values
specify the start and end of the category range; if the start of the category
range is zero then it is omitted.
See Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt for more details.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
Add support for the enumerated tag (tag type #2) to the CIPSOv4 protocol.
The enumerated tag allows for 15 categories to be specified in a CIPSO option,
where each category is an unsigned 16 bit field with a maximum value of 65534.
See Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt for more details.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
The original NetLabel category bitmap was a straight char bitmap which worked
fine for the initial release as it only supported 240 bits due to limitations
in the CIPSO restricted bitmap tag (tag type 0x01). This patch converts that
straight char bitmap into an extensibile/sparse bitmap in order to lay the
foundation for other CIPSO tag types and protocols.
This patch also has a nice side effect in that all of the security attributes
passed by NetLabel into the LSM are now in a format which is in the host's
native byte/bit ordering which makes the LSM specific code much simpler; look
at the changes in security/selinux/ss/ebitmap.c as an example.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
The cipso_v4_doi_search() function behaves the same as cipso_v4_doi_getdef()
but is a local, static function so use it whenever possibile in the CIPSOv4
code base.
Signed-of-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
The CIPSOv4 translated tag #1 mapping does not always return the correct error
code if the desired mapping does not exist; instead of returning -EPERM it
returns -ENOSPC indicating that the buffer is not large enough to hold the
translated value. This was caused by failing to check a specific error
condition. This patch fixes this so that unknown mappings return
-EPERM which is consistent with the rest of the related CIPSOv4 code.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
While the original CIPSOv4 code had provisions for multiple tag types the
implementation was not as great as it could be, pushing a lot of non-tag
specific processing into the tag specific code blocks. This patch fixes that
issue making it easier to support multiple tag types in the future.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
Currently the CIPSOv4 engine does not do any sort of checking when a new DOI
definition is added. The tags are still verified but only as a side effect of
normal NetLabel operation (packet processing, socket labeling, etc.) which
would cause application errors due to the faulty configuration. This patch
adds tag checking when new DOI definition are added allowing us to catch these
configuration problems when they happen.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
Right now the NetLabel code always jumps into the CIPSOv4 layer to determine if
a CIPSO IP option is present. However, we can do this check directly in the
NetLabel code by making use of the CIPSO_V4_OPTEXIST() macro which should save
us a function call in the common case of not having a CIPSOv4 option present.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
The existing netlbl_lsm_secattr struct required the LSM to check all of the
fields to determine if any security attributes were present resulting in a lot
of work in the common case of no attributes. This patch adds a 'flags' field
which is used to indicate which attributes are present in the structure; this
should allow the LSM to do a quick comparison to determine if the structure
holds any security attributes.
Example:
if (netlbl_lsm_secattr->flags)
/* security attributes present */
else
/* NO security attributes present */
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
