This defaults the label of socket-specific IPSec policies to be the
same as the socket they are set on.
Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This labels the flows that could utilize IPSec xfrms at the points the
flows are defined so that IPSec policy and SAs at the right label can
be used.
The following protos are currently not handled, but they should
continue to be able to use single-labeled IPSec like they currently
do.
ipmr
ip_gre
ipip
igmp
sit
sctp
ip6_tunnel (IPv6 over IPv6 tunnel device)
decnet
Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This includes the security context of a security association created
for use by IKE in the acquire messages sent to IKE daemons using
netlink/xfrm_user. This would allow the daemons to include the
security context in the negotiation, so that the resultant association
is unique to that security context.
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This implements a seemless mechanism for xfrm policy selection and
state matching based on the flow sid. This also includes the necessary
SELinux enforcement pieces.
Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch converts IPsec to use the new HMAC template. The names of
existing simple digest algorithms may still be used to refer to their
HMAC composites.
The same structure can be used by other MACs such as AES-XCBC-MAC.
This patch also switches from the digest interface to hash.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch converts IPSec/ESP to use the new block cipher type where
applicable. Similar to the HMAC conversion, existing algorithm names
have been kept for compatibility.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds a compatibility name field for each IPsec algorithm. This
is needed when parameterised algorithms are used. For example, "md5" will
become "hmac(md5)", and "aes" will become "cbc(aes)".
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The header file linux/crypto.h is only needed by a few files so including
it in net/xfrm.h (which is included by half of the networking stack) is a
waste. This patch moves it out of net/xfrm.h and into the specific header
files that actually need it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
If dst->obsolete is -1, this is a signal from the
bundle creator that we want the XFRM dst and the
dsts that it references to be validated on every
use.
I misunderstood this intention when I changed
xfrm_dst_check() to always return NULL.
Now, when we purge a dst entry, by running dst_free()
on it. This will set the dst->obsolete to a positive
integer, and we want to return NULL in that case so
that the socket does a relookup for the route.
Thus, if dst->obsolete<0, let stale_bundle() validate
the state, else always return NULL.
In general, we need to do things more intelligently
here because we flush too much state during rule
changes. Herbert Xu has some ideas wherein the key
manager gives us some help in this area. We can also
use smarter state management algorithms inside of
the kernel as well.
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes the unused EXPORT_SYMBOL(xfrm_state_mtu).
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch encapsulates the usage of eff_cap (in netlink_skb_params) within
the security framework by extending security_netlink_recv to include a required
capability parameter and converting all direct usage of eff_caps outside
of the lsm modules to use the interface. It also updates the SELinux
implementation of the security_netlink_send and security_netlink_recv
hooks to take advantage of the sid in the netlink_skb_params struct.
This also enables SELinux to perform auditing of netlink capability checks.
Please apply, for 2.6.18 if possible.
Signed-off-by: Darrel Goeddel <dgoeddel@trustedcs.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Assignment used as truth value in xfrm_del_sa()
and xfrm_get_policy().
Wrong argument type declared for security_xfrm_state_delete()
when SELINUX is disabled.
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch contains a fix for the previous patch that adds security
contexts to IPsec policies and security associations. In the previous
patch, no authorization (besides the check for write permissions to
SAD and SPD) is required to delete IPsec policies and security
assocations with security contexts. Thus a user authorized to change
SAD and SPD can bypass the IPsec policy authorization by simply
deleteing policies with security contexts. To fix this security hole,
an additional authorization check is added for removing security
policies and security associations with security contexts.
Note that if no security context is supplied on add or present on
policy to be deleted, the SELinux module allows the change
unconditionally. The hook is called on deletion when no context is
present, which we may want to change. At present, I left it up to the
module.
LSM changes:
The patch adds two new LSM hooks: xfrm_policy_delete and
xfrm_state_delete. The new hooks are necessary to authorize deletion
of IPsec policies that have security contexts. The existing hooks
xfrm_policy_free and xfrm_state_free lack the context to do the
authorization, so I decided to split authorization of deletion and
memory management of security data, as is typical in the LSM
interface.
Use:
The new delete hooks are checked when xfrm_policy or xfrm_state are
deleted by either the xfrm_user interface (xfrm_get_policy,
xfrm_del_sa) or the pfkey interface (pfkey_spddelete, pfkey_delete).
SELinux changes:
The new policy_delete and state_delete functions are added.
Signed-off-by: Catherine Zhang <cxzhang@watson.ibm.com>
Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds the structure xfrm_mode. It is meant to represent
the operations carried out by transport/tunnel modes.
By doing this we allow additional encapsulation modes to be added
without clogging up the xfrm_input/xfrm_output paths.
Candidate modes include 4-to-6 tunnel mode, 6-to-4 tunnel mode, and
BEET modes.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The number of locks used to manage afinfo structures can easily be reduced
down to one each for policy and state respectively. This is based on the
observation that the write locks are only held by module insertion/removal
which are very rare events so there is no need to further differentiate
between the insertion of modules like ipv6 versus esp6.
The removal of the read locks in xfrm4_policy.c/xfrm6_policy.c might look
suspicious at first. However, after you realise that nobody ever takes
the corresponding write lock you'll feel better :)
As far as I can gather it's an attempt to guard against the removal of
the corresponding modules. Since neither module can be unloaded at all
we can leave it to whoever fixes up IPv6 unloading :)
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
xfrm_policy_afinfo_lock can be taken in bh context, at:
[<c013fe1a>] lockdep_acquire_read+0x54/0x6d
[<c0f6e024>] _read_lock+0x15/0x22
[<c0e8fcdb>] xfrm_policy_get_afinfo+0x1a/0x3d
[<c0e8fd10>] xfrm_decode_session+0x12/0x32
[<c0e66094>] ip_route_me_harder+0x1c9/0x25b
[<c0e770d3>] ip_nat_local_fn+0x94/0xad
[<c0e2bbc8>] nf_iterate+0x2e/0x7a
[<c0e2bc50>] nf_hook_slow+0x3c/0x9e
[<c0e3a342>] ip_push_pending_frames+0x2de/0x3a7
[<c0e53e19>] icmp_push_reply+0x136/0x141
[<c0e543fb>] icmp_reply+0x118/0x1a0
[<c0e54581>] icmp_echo+0x44/0x46
[<c0e53fad>] icmp_rcv+0x111/0x138
[<c0e36764>] ip_local_deliver+0x150/0x1f9
[<c0e36be2>] ip_rcv+0x3d5/0x413
[<c0df760f>] netif_receive_skb+0x337/0x356
[<c0df76c3>] process_backlog+0x95/0x110
[<c0df5fe2>] net_rx_action+0xa5/0x16d
[<c012d8a7>] __do_softirq+0x6f/0xe6
[<c0105ec2>] do_softirq+0x52/0xb1
this means that all write-locking of xfrm_policy_afinfo_lock must be
bh-safe. This patch fixes xfrm_policy_register_afinfo() and
xfrm_policy_unregister_afinfo().
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
xfrm_state_afinfo_lock can be read-locked from bh context, so take it
in a bh-safe manner in xfrm_state_register_afinfo() and
xfrm_state_unregister_afinfo(). Found by the lock validator.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
xfrm typemap->lock may be used in softirq context, so all write_lock()
uses must be softirq-safe.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Send aevent immediately if we have sent nothing since last timer and
this is the first packet.
Fixes a corner case when packet threshold is very high, the timer low
and a very low packet rate input which is bursty.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes the *_decap_state structures which were previously
used to share state between input/post_input. This is no longer
needed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
When xfrm_user isn't loaded xfrm_nl is NULL, which makes IPsec crash because
xfrm_aevent_is_on passes the NULL pointer to netlink_has_listeners as socket.
A second problem is that the xfrm_nl pointer is not cleared when the socket
is releases at module unload time.
Protect references of xfrm_nl from outside of xfrm_user by RCU, check
that the socket is present in xfrm_aevent_is_on and set it to NULL
when unloading xfrm_user.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
First, it warns when PAGE_SIZE >= 64K because the ctx_len
field is 16-bits.
Secondly, if there are any real length limitations it can
be verified by the security layer security_xfrm_state_alloc()
call.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is similar to the SA expire insertion patch - only it inserts
expires for SP.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows a user to insert SA expires. This is useful to
do on an HA backup for the case of byte counts but may not be very
useful for the case of time based expiry.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
This introduces a feature similar to the one described in RFC 2367:
"
... the application needing an SA sends a PF_KEY
SADB_ACQUIRE message down to the Key Engine, which then either
returns an error or sends a similar SADB_ACQUIRE message up to one or
more key management applications capable of creating such SAs.
...
...
The third is where an application-layer consumer of security
associations (e.g. an OSPFv2 or RIPv2 daemon) needs a security
association.
Send an SADB_ACQUIRE message from a user process to the kernel.
<base, address(SD), (address(P),) (identity(SD),) (sensitivity,)
proposal>
The kernel returns an SADB_ACQUIRE message to registered
sockets.
<base, address(SD), (address(P),) (identity(SD),) (sensitivity,)
proposal>
The user-level consumer waits for an SADB_UPDATE or SADB_ADD
message for its particular type, and then can use that
association by using SADB_GET messages.
"
An app such as OSPF could then use ipsec KM to get keys
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch provides the core functionality needed for sync events
for ipsec. Derived work of Krisztian KOVACS <hidden@balabit.hu>
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
The only reason post_input exists at all is that it gives us the
potential to adjust the checksums incrementally in future which
we ought to do.
However, after thinking about it for a bit we can adjust the
checksums without using this post_input stuff at all. The crucial
point is that only the inner-most NAT-T SA needs to be considered
when adjusting checksums. What's more, the checksum adjustment
comes down to a single u32 due to the linearity of IP checksums.
We just happen to have a spare u32 lying around in our skb structure :)
When ip_summed is set to CHECKSUM_NONE on input, the value of skb->csum
is currently unused. All we have to do is to make that the checksum
adjustment and voila, there goes all the post_input and decap structures!
I've left in the decap data structures for now since it's intricately
woven into the sec_path stuff. We can kill them later too.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
We often just do an atomic_dec(&x->refcnt) on an xfrm_state object
because we know there is more than 1 reference remaining and thus
we can elide the heavier xfrm_state_put() call.
Do this behind an inline function called __xfrm_state_put() so that is
more obvious and also to allow us to more cleanly add refcount
debugging later.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bridge-netfilter code attaches a fake dst_entry with dst->ops == NULL
to purely bridged packets. When these packets are SNATed and a policy
lookup is done, xfrm_lookup crashes because it tries to dereference
dst->ops.
Change xfrm_lookup not to dereference dst->ops before checking for the
DST_NOXFRM flag and set this flag in the fake dst_entry.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Problem discovered and initial patch by Olaf Kirch:
there's a problem with IPsec that has been bugging some of our users
for the last couple of kernel revs. Every now and then, IPsec will
freeze the machine completely. This is with openswan user land,
and with kernels up to and including 2.6.16-rc2.
I managed to debug this a little, and what happens is that we end
up looping in xfrm_lookup, and never get out. With a bit of debug
printks added, I can this happening:
ip_route_output_flow calls xfrm_lookup
xfrm_find_bundle returns NULL (apparently we're in the
middle of negotiating a new SA or something)
We therefore call xfrm_tmpl_resolve. This returns EAGAIN
We go to sleep, waiting for a policy update.
Then we loop back to the top
Apparently, the dst_orig that was passed into xfrm_lookup
has been dropped from the routing table (obsolete=2)
This leads to the endless loop, because we now create
a new bundle, check the new bundle and find it's stale
(stale_bundle -> xfrm_bundle_ok -> dst_check() return 0)
People have been testing with the patch below, which seems to fix the
problem partially. They still see connection hangs however (things
only clear up when they start a new ping or new ssh). So the patch
is obvsiouly not sufficient, and something else seems to go wrong.
I'm grateful for any hints you may have...
I suggest that we simply bail out always. If the dst decides to die
on us later on, the packet will be dropped anyway. So there is no
great urgency to retry here. Once we have the proper resolution
queueing, we can then do the retry again.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Olaf Kirch <okir@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
A bunch of asm/bug.h includes are both not needed (since it will get
pulled anyway) and bogus (since they are done too early). Removed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This changes some simple "if (x) BUG();" statements to "BUG_ON(x);"
Signed-off-by: Kris Katterjohn <kjak@users.sourceforge.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Handle NAT of decapsulated IPsec packets by reconstructing the struct flowi
of the original packet from the conntrack information for IPsec policy
checks.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
ip_route_me_harder doesn't use the port numbers of the xfrm lookup and
uses ip_route_input for non-local addresses which doesn't do a xfrm
lookup, ip6_route_me_harder doesn't do a xfrm lookup at all.
Use xfrm_decode_session and do the lookup manually, make sure both
only do the lookup if the packet hasn't been transformed already.
Makeing sure the lookup only happens once needs a new field in the
IP6CB, which exceeds the size of skb->cb. The size of skb->cb is
increased to 48b. Apparently the IPv6 mobile extensions need some
more room anyway.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch contains two corrections to the LSM-IPsec Nethooks patches
previously applied.
(1) free a security context on a failed insert via xfrm_user
interface in xfrm_add_policy. Memory leak.
(2) change the authorization of the allocation of a security context
in a xfrm_policy or xfrm_state from both relabelfrom and relabelto
to setcontext.
Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch series implements per packet access control via the
extension of the Linux Security Modules (LSM) interface by hooks in
the XFRM and pfkey subsystems that leverage IPSec security
associations to label packets. Extensions to the SELinux LSM are
included that leverage the patch for this purpose.
This patch implements the changes necessary to the XFRM subsystem,
pfkey interface, ipv4/ipv6, and xfrm_user interface to restrict a
socket to use only authorized security associations (or no security
association) to send/receive network packets.
Patch purpose:
The patch is designed to enable access control per packets based on
the strongly authenticated IPSec security association. Such access
controls augment the existing ones based on network interface and IP
address. The former are very coarse-grained, and the latter can be
spoofed. By using IPSec, the system can control access to remote
hosts based on cryptographic keys generated using the IPSec mechanism.
This enables access control on a per-machine basis or per-application
if the remote machine is running the same mechanism and trusted to
enforce the access control policy.
Patch design approach:
The overall approach is that policy (xfrm_policy) entries set by
user-level programs (e.g., setkey for ipsec-tools) are extended with a
security context that is used at policy selection time in the XFRM
subsystem to restrict the sockets that can send/receive packets via
security associations (xfrm_states) that are built from those
policies.
A presentation available at
www.selinux-symposium.org/2005/presentations/session2/2-3-jaeger.pdf
from the SELinux symposium describes the overall approach.
Patch implementation details:
On output, the policy retrieved (via xfrm_policy_lookup or
xfrm_sk_policy_lookup) must be authorized for the security context of
the socket and the same security context is required for resultant
security association (retrieved or negotiated via racoon in
ipsec-tools). This is enforced in xfrm_state_find.
On input, the policy retrieved must also be authorized for the socket
(at __xfrm_policy_check), and the security context of the policy must
also match the security association being used.
The patch has virtually no impact on packets that do not use IPSec.
The existing Netfilter (outgoing) and LSM rcv_skb hooks are used as
before.
Also, if IPSec is used without security contexts, the impact is
minimal. The LSM must allow such policies to be selected for the
combination of socket and remote machine, but subsequent IPSec
processing proceeds as in the original case.
Testing:
The pfkey interface is tested using the ipsec-tools. ipsec-tools have
been modified (a separate ipsec-tools patch is available for version
0.5) that supports assignment of xfrm_policy entries and security
associations with security contexts via setkey and the negotiation
using the security contexts via racoon.
The xfrm_user interface is tested via ad hoc programs that set
security contexts. These programs are also available from me, and
contain programs for setting, getting, and deleting policy for testing
this interface. Testing of sa functions was done by tracing kernel
behavior.
Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The problem is that when new policies are inserted, sockets do not see
the update (but all new route lookups do).
This bug is related to the SA insertion stale route issue solved
recently, and this policy visibility problem can be fixed in a similar
way.
The fix is to flush out the bundles of all policies deeper than the
policy being inserted. Consider beginning state of "outgoing"
direction policy list:
policy A --> policy B --> policy C --> policy D
First, realize that inserting a policy into a list only potentially
changes IPSEC routes for that direction. Therefore we need not bother
considering the policies for other directions. We need only consider
the existing policies in the list we are doing the inserting.
Consider new policy "B'", inserted after B.
policy A --> policy B --> policy B' --> policy C --> policy D
Two rules:
1) If policy A or policy B matched before the insertion, they
appear before B' and thus would still match after inserting
B'
2) Policy C and D, now "shadowed" and after policy B', potentially
contain stale routes because policy B' might be selected
instead of them.
Therefore we only need flush routes assosciated with policies
appearing after a newly inserted policy, if any.
Signed-off-by: David S. Miller <davem@davemloft.net>
When we insert a new xfrm_state which potentially
subsumes an existing one, make sure all cached
bundles are flushed so that the new SA is used
immediately.
Signed-off-by: David S. Miller <davem@davemloft.net>
Most netlink families make no use of the done() callback, making
it optional gets rid of all unnecessary dummy implementations.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Venkat Yekkirala