Commit Graph

58 Commits

Author SHA1 Message Date
Miika Komu
76b3f055f3 [IPSEC]: Add encapsulation family.
Signed-off-by: Miika Komu <miika@iki.fi>
Signed-off-by: Diego Beltrami <Diego.Beltrami@hiit.fi>
Signed-off-by: Kazunori Miyazawa <miyazawa@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:31:48 -08:00
Andrew Morton
776810217a [XFRM]: uninline xfrm_selector_match()
Six callsites, huge.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:21:36 -08:00
Venkat Yekkirala
67f83cbf08 SELinux: Fix SA selection semantics
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>
2006-12-02 21:21:34 -08:00
Venkat Yekkirala
3bccfbc7a7 IPsec: fix handling of errors for socket policies
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>
2006-10-11 23:59:39 -07:00
Venkat Yekkirala
5b368e61c2 IPsec: correct semantics for SELinux policy matching
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>
2006-10-11 23:59:37 -07:00
James Morris
134b0fc544 IPsec: propagate security module errors up from flow_cache_lookup
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>
2006-10-11 23:59:34 -07:00
David S. Miller
ae8c05779a [XFRM]: Clearing xfrm_policy_count[] to zero during flush is incorrect.
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>
2006-10-04 00:31:02 -07:00
Patrick McHardy
a1e59abf82 [XFRM]: Fix wildcard as tunnel source
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>
2006-09-22 15:19:06 -07:00
James Morris
d1d9facfd1 [XFRM]: remove xerr_idxp from __xfrm_policy_check()
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>
2006-09-22 15:18:49 -07:00
Alexey Dobriyan
e5d679f339 [NET]: Use SLAB_PANIC
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22 15:18:19 -07:00
David S. Miller
acba48e1a3 [XFRM]: Respect priority in policy lookups.
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>
2006-09-22 15:18:05 -07:00
David S. Miller
44e36b42a8 [XFRM]: Extract common hashing code into xfrm_hash.[ch]
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22 15:08:49 -07:00
David S. Miller
2518c7c2b3 [XFRM]: Hash policies when non-prefixed.
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>
2006-09-22 15:08:48 -07:00
David S. Miller
1c09539975 [XFRM]: Purge dst references to deleted SAs passively.
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>
2006-09-22 15:08:46 -07:00
David S. Miller
c7f5ea3a4d [XFRM]: Do not flush all bundles on SA insert.
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>
2006-09-22 15:08:45 -07:00
David S. Miller
9d4a706d85 [XFRM]: Add generation count to xfrm_state and xfrm_dst.
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>
2006-09-22 15:08:42 -07:00
Masahide NAKAMURA
41a49cc3c0 [XFRM]: Add sorting interface for state and template.
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>
2006-09-22 15:08:34 -07:00
Masahide NAKAMURA
4e81bb8336 [XFRM] POLICY: sub policy support.
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>
2006-09-22 15:08:34 -07:00
Masahide NAKAMURA
df0ba92a99 [XFRM]: Trace which secpath state is reject factor.
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>
2006-09-22 15:08:29 -07:00
Masahide NAKAMURA
e53820de0f [XFRM] IPV6: Restrict bundle reusing
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>
2006-09-22 15:06:44 -07:00
Masahide NAKAMURA
9e51fd371a [XFRM]: Rename secpath_has_tunnel to secpath_has_nontransport.
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>
2006-09-22 15:06:40 -07:00
Masahide NAKAMURA
f3bd484021 [XFRM]: Restrict authentication algorithm only when inbound transformation protocol is IPsec.
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>
2006-09-22 15:06:38 -07:00
Masahide NAKAMURA
7e49e6de30 [XFRM]: Add XFRM_MODE_xxx for future use.
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>
2006-09-22 15:05:15 -07:00
Venkat Yekkirala
beb8d13bed [MLSXFRM]: Add flow labeling
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>
2006-09-22 14:53:27 -07:00
Venkat Yekkirala
e0d1caa7b0 [MLSXFRM]: Flow based matching of xfrm policy and state
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>
2006-09-22 14:53:24 -07:00
David S. Miller
d49c73c729 [IPSEC]: Validate properly in xfrm_dst_check()
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>
2006-08-13 18:55:53 -07:00
Panagiotis Issaris
0da974f4f3 [NET]: Conversions from kmalloc+memset to k(z|c)alloc.
Signed-off-by: Panagiotis Issaris <takis@issaris.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-21 14:51:30 -07:00
Jörn Engel
6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Herbert Xu
b59f45d0b2 [IPSEC] xfrm: Abstract out encapsulation modes
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>
2006-06-17 21:28:39 -07:00
Herbert Xu
546be2405b [IPSEC] xfrm: Undo afinfo lock proliferation
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>
2006-06-17 21:28:37 -07:00
Ingo Molnar
e959d8121f [XFRM]: fix incorrect xfrm_policy_afinfo_lock use
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>
2006-04-29 18:33:21 -07:00
Ingo Molnar
8dff7c2970 [XFRM]: fix softirq-unsafe xfrm typemap->lock use
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>
2006-04-29 18:33:18 -07:00
Herbert Xu
dbe5b4aaaf [IPSEC]: Kill unused decap state structure
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>
2006-04-01 00:54:16 -08:00
Arjan van de Ven
4a3e2f711a [NET] sem2mutex: 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>
2006-03-20 22:33:17 -08:00
David S. Miller
a70fcb0ba3 [XFRM]: Add some missing exports.
To fix the case of modular xfrm_user.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 19:18:52 -08:00
Jamal Hadi Salim
6c5c8ca7ff [IPSEC]: Sync series - policy expires
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>
2006-03-20 19:17:25 -08:00
Herbert Xu
752c1f4c78 [IPSEC]: Kill post_input hook and do NAT-T in esp_input directly
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>
2006-02-27 13:00:40 -08:00
Patrick McHardy
42cf93cd46 [NETFILTER]: Fix bridge netfilter related in xfrm_lookup
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>
2006-02-23 16:10:51 -08:00
Patrick McHardy
9951101438 [XFRM]: Fix policy double put
The policy is put once immediately and once at the error label, which results
in the following Oops:

kernel BUG at net/xfrm/xfrm_policy.c:250!
invalid opcode: 0000 [#2]
PREEMPT
[...]
CPU:    0
EIP:    0060:[<c028caf7>]    Not tainted VLI
EFLAGS: 00210246   (2.6.16-rc3 #39)
EIP is at __xfrm_policy_destroy+0xf/0x46
eax: d49f2000   ebx: d49f2000   ecx: f74bd880   edx: f74bd280
esi: d49f2000   edi: 00000001   ebp: cd506dcc   esp: cd506dc8
ds: 007b   es: 007b   ss: 0068
Process ssh (pid: 31970, threadinfo=cd506000 task=cfb04a70)
Stack: <0>cd506000 cd506e34 c028e92b ebde7280 cd506e58 cd506ec0 f74bd280 00000000
       00000214 0000000a 0000000a 00000000 00000002 f7ae6000 00000000 cd506e58
       cd506e14 c0299e36 f74bd280 e873fe00 c02943fd cd506ec0 ebde7280 f271f440
Call Trace:
 [<c0103a44>] show_stack_log_lvl+0xaa/0xb5
 [<c0103b75>] show_registers+0x126/0x18c
 [<c0103e68>] die+0x14e/0x1db
 [<c02b6809>] do_trap+0x7c/0x96
 [<c0104237>] do_invalid_op+0x89/0x93
 [<c01035af>] error_code+0x4f/0x54
 [<c028e92b>] xfrm_lookup+0x349/0x3c2
 [<c02b0b0d>] ip6_datagram_connect+0x317/0x452
 [<c0281749>] inet_dgram_connect+0x49/0x54
 [<c02404d2>] sys_connect+0x51/0x68
 [<c0240928>] sys_socketcall+0x6f/0x166
 [<c0102aa1>] syscall_call+0x7/0xb

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-19 22:11:50 -08:00
Herbert Xu
00de651d14 [IPSEC]: Fix strange IPsec freeze.
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>
2006-02-13 16:01:27 -08:00
Al Viro
1b8623545b [PATCH] remove bogus asm/bug.h includes.
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>
2006-02-07 20:56:35 -05:00
Kris Katterjohn
09a626600b [NET]: Change some "if (x) BUG();" to "BUG_ON(x);"
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>
2006-01-09 14:16:18 -08:00
Patrick McHardy
eb9c7ebe69 [NETFILTER]: Handle NAT in IPsec policy checks
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>
2006-01-07 12:57:37 -08:00
Patrick McHardy
3e3850e989 [NETFILTER]: Fix xfrm lookup in ip_route_me_harder/ip6_route_me_harder
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>
2006-01-07 12:57:33 -08:00
Trent Jaeger
df71837d50 [LSM-IPSec]: Security association restriction.
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>
2006-01-03 13:10:24 -08:00
David S. Miller
9b78a82c1c [IPSEC]: Fix policy updates missed by sockets
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>
2005-12-22 07:39:48 -08:00
David S. Miller
399c180ac5 [IPSEC]: Perform SA switchover immediately.
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>
2005-12-19 14:23:23 -08:00
Herbert Xu
80b30c1023 [IPSEC]: Kill obsolete get_mss function
Now that we've switched over to storing MTUs in the xfrm_dst entries,
we no longer need the dst's get_mss methods.  This patch gets rid of
them.

It also documents the fact that our MTU calculation is not optimal
for ESP.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-10-26 00:48:45 -02:00
Al Viro
dd0fc66fb3 [PATCH] gfp flags annotations - part 1
- added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-08 15:00:57 -07:00
Herbert Xu
77d8d7a684 [IPSEC]: Document that policy direction is derived from the index.
Here is a patch that adds a helper called xfrm_policy_id2dir to
document the fact that the policy direction can be and is derived
from the index.

This is based on a patch by YOSHIFUJI Hideaki and 210313105@suda.edu.cn.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-05 12:15:12 -07:00