Fix the selection of an SA for an outgoing packet to be at the same
context as the originating socket/flow. This eliminates the SELinux
policy's ability to use/sendto SAs with contexts other than the socket's.
With this patch applied, the SELinux policy will require one or more of the
following for a socket to be able to communicate with/without SAs:
1. To enable a socket to communicate without using labeled-IPSec SAs:
allow socket_t unlabeled_t:association { sendto recvfrom }
2. To enable a socket to communicate with labeled-IPSec SAs:
allow socket_t self:association { sendto };
allow socket_t peer_sa_t:association { recvfrom };
Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: James Morris <jmorris@namei.org>
When application uses XFRM_MSG_GETSA to get state entry through
netlink socket and kernel has no matching one, the application expects
reply message with error status by kernel.
Kernel doesn't send the message back in the case of Mobile IPv6 route
optimization protocols (i.e. routing header or destination options
header). This is caused by incorrect return code "0" from
net/xfrm/xfrm_user.c(xfrm_user_state_lookup) and it makes kernel skip
to acknowledge at net/netlink/af_netlink.c(netlink_rcv_skb).
This patch fix to reply ESRCH to application.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: TAKAMIYA Noriaki <takamiya@po.ntts.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
I actually dont have a test case for these; i just found them by
inspection. Refer to patch "[XFRM]: Sub-policies broke policy events"
for more info
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Acked-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
XFRM policy events are broken when sub-policy feature is turned on.
A simple test to verify this:
run ip xfrm mon on one window and add then delete a policy on another
window ..
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Acked-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use memcpy() to move xfrm_address_t objects in and out
of netlink messages. The vast majority of xfrm_user was
doing this properly, except for copy_from_user_state()
and copy_to_user_state().
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
Andrew Morton