xfrm_state_num needs to be increased for XFRM_STATE_ACQ states created
by xfrm_state_find() to prevent the counter from going negative when
the state is destroyed.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Missing counter bump when hashing in a new ACQ
xfrm_state.
Now that we have two spots to do the hash grow
check, break it out into a helper function.
Signed-off-by: David S. Miller <davem@davemloft.net>
This treats the security errors encountered in the case of
socket policy matching, the same as how these are treated in
the case of main/sub policies, which is to return a full lookup
failure.
Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: James Morris <jmorris@namei.org>
Currently when an IPSec policy rule doesn't specify a security
context, it is assumed to be "unlabeled" by SELinux, and so
the IPSec policy rule fails to match to a flow that it would
otherwise match to, unless one has explicitly added an SELinux
policy rule allowing the flow to "polmatch" to the "unlabeled"
IPSec policy rules. In the absence of such an explicitly added
SELinux policy rule, the IPSec policy rule fails to match and
so the packet(s) flow in clear text without the otherwise applicable
xfrm(s) applied.
The above SELinux behavior violates the SELinux security notion of
"deny by default" which should actually translate to "encrypt by
default" in the above case.
This was first reported by Evgeniy Polyakov and the way James Morris
was seeing the problem was when connecting via IPsec to a
confined service on an SELinux box (vsftpd), which did not have the
appropriate SELinux policy permissions to send packets via IPsec.
With this patch applied, SELinux "polmatching" of flows Vs. IPSec
policy rules will only come into play when there's a explicit context
specified for the IPSec policy rule (which also means there's corresponding
SELinux policy allowing appropriate domains/flows to polmatch to this context).
Secondly, when a security module is loaded (in this case, SELinux), the
security_xfrm_policy_lookup() hook can return errors other than access denied,
such as -EINVAL. We were not handling that correctly, and in fact
inverting the return logic and propagating a false "ok" back up to
xfrm_lookup(), which then allowed packets to pass as if they were not
associated with an xfrm policy.
The solution for this is to first ensure that errno values are
correctly propagated all the way back up through the various call chains
from security_xfrm_policy_lookup(), and handled correctly.
Then, flow_cache_lookup() is modified, so that if the policy resolver
fails (typically a permission denied via the security module), the flow
cache entry is killed rather than having a null policy assigned (which
indicates that the packet can pass freely). This also forces any future
lookups for the same flow to consult the security module (e.g. SELinux)
for current security policy (rather than, say, caching the error on the
flow cache entry).
This patch: Fix the selinux side of things.
This makes sure SELinux polmatching of flow contexts to IPSec policy
rules comes into play only when an explicit context is associated
with the IPSec policy rule.
Also, this no longer defaults the context of a socket policy to
the context of the socket since the "no explicit context" case
is now handled properly.
Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: James Morris <jmorris@namei.org>
When a security module is loaded (in this case, SELinux), the
security_xfrm_policy_lookup() hook can return an access denied permission
(or other error). We were not handling that correctly, and in fact
inverting the return logic and propagating a false "ok" back up to
xfrm_lookup(), which then allowed packets to pass as if they were not
associated with an xfrm policy.
The way I was seeing the problem was when connecting via IPsec to a
confined service on an SELinux box (vsftpd), which did not have the
appropriate SELinux policy permissions to send packets via IPsec.
The first SYNACK would be blocked, because of an uncached lookup via
flow_cache_lookup(), which would fail to resolve an xfrm policy because
the SELinux policy is checked at that point via the resolver.
However, retransmitted SYNACKs would then find a cached flow entry when
calling into flow_cache_lookup() with a null xfrm policy, which is
interpreted by xfrm_lookup() as the packet not having any associated
policy and similarly to the first case, allowing it to pass without
transformation.
The solution presented here is to first ensure that errno values are
correctly propagated all the way back up through the various call chains
from security_xfrm_policy_lookup(), and handled correctly.
Then, flow_cache_lookup() is modified, so that if the policy resolver
fails (typically a permission denied via the security module), the flow
cache entry is killed rather than having a null policy assigned (which
indicates that the packet can pass freely). This also forces any future
lookups for the same flow to consult the security module (e.g. SELinux)
for current security policy (rather than, say, caching the error on the
flow cache entry).
Signed-off-by: James Morris <jmorris@namei.org>
This patch introduces the BEET mode (Bound End-to-End Tunnel) with as
specified by the ietf draft at the following link:
http://www.ietf.org/internet-drafts/draft-nikander-esp-beet-mode-06.txt
The patch provides only single family support (i.e. inner family =
outer family).
Signed-off-by: Diego Beltrami <diego.beltrami@gmail.com>
Signed-off-by: Miika Komu <miika@iki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Abhinav Pathak <abhinav.pathak@hiit.fi>
Signed-off-by: Jeff Ahrenholz <ahrenholz@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we flush policies, we do a type match so we might not
actually delete all policies matching a certain direction.
So keep track of how many policies we actually kill and
subtract that number from xfrm_policy_count[dir] at the
end.
Based upon a patch by Masahide NAKAMURA.
Signed-off-by: David S. Miller <davem@davemloft.net>
Src hash is introduced for Mobile IPv6 route optimization usage.
On current kenrel code it is calculated with source address only.
It results we uses the same hash value for outbound state (when
the node has only one address for Mobile IPv6).
This patch use also destination address as peer information for
src hash to be dispersed.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
SPI=0 is used for acquired IPsec SA and MIPv6 RO state.
Such state should not be added to the SPI hash
because we do not care about it on deleting path.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
spi argument of xfrm_state_lookup() is net-endian
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Hashing SAs by source address breaks templates with wildcards as tunnel
source since the source address used for hashing/lookup is still 0/0.
Move source address lookup to xfrm_tmpl_resolve_one() so we can use the
real address in the lookup.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
It seems that during the MIPv6 respin, some code which was originally
conditionally compiled around CONFIG_XFRM_ADVANCED was accidently left
in after the config option was removed.
This patch removes an extraneous pointer (xerr_idxp) which is no
longer needed.
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Even if we find an exact match in the hash table,
we must inspect the inexact list to look for a match
with a better priority.
Noticed by Masahide NAKAMURA <nakam@linux-ipv6.org>.
Signed-off-by: David S. Miller <davem@davemloft.net>
This idea is from Alexey Kuznetsov.
It is common for policies to be non-prefixed. And for
that case we can optimize lookups, insert, etc. quite
a bit.
For each direction, we have a dynamically sized policy
hash table for non-prefixed policies. We also have a
hash table on policy->index.
For prefixed policies, we have a list per-direction which
we will consult on lookups when a non-prefix hashtable
lookup fails.
This still isn't as efficient as I would like it. There
are four immediate problems:
1) Lots of excessive refcounting, which can be fixed just
like xfrm_state was
2) We do 2 hash probes on insert, one to look for dups and
one to allocate a unique policy->index. Althought I wonder
how much this matters since xfrm_state inserts do up to
3 hash probes and that seems to perform fine.
3) xfrm_policy_insert() is very complex because of the priority
ordering and entry replacement logic.
4) Lots of counter bumping, in addition to policy refcounts,
in the form of xfrm_policy_count[]. This is merely used
to let code path(s) know that some IPSEC rules exist. So
this count is indexed per-direction, maybe that is overkill.
Signed-off-by: David S. Miller <davem@davemloft.net>
The source address is always non-prefixed so we should use
it to help give entropy to the bydst hash.
Signed-off-by: David S. Miller <davem@davemloft.net>
The refcounting done for timers and hash table insertions
are just wasted cycles. We can eliminate all of this
refcounting because:
1) The implicit refcount when the xfrm_state object is active
will always be held while the object is in the hash tables.
We never kfree() the xfrm_state until long after we've made
sure that it has been unhashed.
2) Timers are even easier. Once we mark that x->km.state as
anything other than XFRM_STATE_VALID (__xfrm_state_delete
sets it to XFRM_STATE_DEAD), any timer that fires will
do nothing and return without rearming the timer.
Therefore we can defer the del_timer calls until when the
object is about to be freed up during GC. We have to use
del_timer_sync() and defer it to GC because we can't do
a del_timer_sync() while holding x->lock which all callers
of __xfrm_state_delete hold.
This makes SA changes even more light-weight.
Signed-off-by: David S. Miller <davem@davemloft.net>
Just let GC and other normal mechanisms take care of getting
rid of DST cache references to deleted xfrm_state objects
instead of walking all the policy bundles.
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead, simply set all potentially aliasing existing xfrm_state
objects to have the current generation counter value.
This will make routes get relooked up the next time an existing
route mentioning these aliased xfrm_state objects gets used,
via xfrm_dst_check().
Signed-off-by: David S. Miller <davem@davemloft.net>
Each xfrm_state inserted gets a new generation counter
value. When a bundle is created, the xfrm_dst objects
get the current generation counter of the xfrm_state
they will attach to at dst->xfrm.
xfrm_bundle_ok() will return false if it sees an
xfrm_dst with a generation count different from the
generation count of the xfrm_state that dst points to.
This provides a facility by which to passively and
cheaply invalidate cached IPSEC routes during SA
database changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
The grow algorithm is simple, we grow if:
1) we see a hash chain collision at insert, and
2) we haven't hit the hash size limit (currently 1*1024*1024 slots), and
3) the number of xfrm_state objects is > the current hash mask
All of this needs some tweaking.
Remove __initdata from "hashdist" so we can use it safely at run time.
Signed-off-by: David S. Miller <davem@davemloft.net>
Sub policy can be used through netlink socket.
PF_KEY uses main only and it is TODO to support sub.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Under two transformation policies it is required to merge them.
This is a platform to sort state for outbound and templates
for inbound respectively.
It will be used when Mobile IPv6 and IPsec are used at the same time.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sub policy is introduced. Main and sub policy are applied the same flow.
(Policy that current kernel uses is named as main.)
It is required another transformation policy management to keep IPsec
and Mobile IPv6 lives separate.
Policy which lives shorter time in kernel should be a sub i.e. normally
main is for IPsec and sub is for Mobile IPv6.
(Such usage as two IPsec policies on different database can be used, too.)
Limitation or TODOs:
- Sub policy is not supported for per socket one (it is always inserted as main).
- Current kernel makes cached outbound with flowi to skip searching database.
However this patch makes it disabled only when "two policies are used and
the first matched one is bypass case" because neither flowi nor bundle
information knows about transformation template size.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Add Kconfig to support sub policy.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
XFRM_MSG_REPORT is a message as notification of state protocol and
selector from kernel to user-space.
Mobile IPv6 will use it when inbound reject is occurred at route
optimization to make user-space know a binding error requirement.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
For Mobile IPv6 usage, it is required to trace which secpath state is
reject factor in order to notify it to user space (to know the address
which cannot be used route optimized communication).
Based on MIPL2 kernel patch.
This patch was also written by: Henrik Petander <petander@tcs.hut.fi>
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add Mobile IPv6 route optimization protocols to netlink interface.
Route optimization states carry care-of address.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Transformation user interface is not only for IPsec.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
For outbound transformation, bundle is checked whether it is
suitable for current flow to be reused or not. In such IPv6 case
as below, transformation may apply incorrect bundle for the flow instead
of creating another bundle:
- The policy selector has destination prefix length < 128
(Two or more addresses can be matched it)
- Its bundle holds dst entry of default route whose prefix length < 128
(Previous traffic was used such route as next hop)
- The policy and the bundle were used a transport mode state and
this time flow address is not matched the bundled state.
This issue is found by Mobile IPv6 usage to protect mobility signaling
by IPsec, but it is not a Mobile IPv6 specific.
This patch adds strict check to xfrm_bundle_ok() for each
state mode and address when prefix length is less than 128.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
With this patch transformation state is updated last used time
for each sending. Xtime is used for it like other state lifetime
expiration.
Mobile IPv6 enabled nodes will want to know traffic status of each
binding (e.g. judgement to request binding refresh by correspondent node,
or to keep home/care-of nonce alive by mobile node).
The last used timestamp is an important hint about it.
Based on MIPL2 kernel patch.
This patch was also written by: Henrik Petander <petander@tcs.hut.fi>
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Care-of address is carried by state as a transformation option like
IPsec encryption/authentication algorithm.
Based on MIPL2 kernel patch.
Signed-off-by: Noriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
On current kernel inbound transformation state is allowed transport and
disallowed tunnel mode when mismatch is occurred between tempates and states.
As the result of adding two more modes by Mobile IPv6, this function name
is misleading. Inbound transformation can allow only transport mode
when mismatch is occurred between template and secpath.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
XFRM_STATE_WILDRECV flag is introduced; the last resort state is set
it and receives packet which is not route optimized but uses such
extension headers i.e. Mobile IPv6 signaling (binding update and
acknowledgement). A node enabled Mobile IPv6 adds the state.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
For Mobile IPv6 usage, routing header or destination options header is
used and it doesn't require this comparison. It is checked only for
IPsec template.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a support to search transformation states by its addresses
by using source address list for Mobile IPv6 usage.
To use it from user-space, it is also added a message type for
source address as a xfrm state option.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Support source address based searching.
Mobile IPv6 will use it.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It will be added two more transformation protocols (routing header
and destination options header) for Mobile IPv6.
xfrm_id_proto_match() can be handle zero as all, IPSEC_PROTO_ANY as
all IPsec and otherwise as exact one.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Put the helper to header for future use.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Transformation mode is used as either IPsec transport or tunnel.
It is required to add two more items, route optimization and inbound trigger
for Mobile IPv6.
Based on MIPL2 kernel patch.
This patch was also written by: Ville Nuorvala <vnuorval@tcs.hut.fi>
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
