Unlike the standard case, disabled anti replay detection needs some
nontrivial extra treatment on ESN. RFC 4303 states:
Note: If a receiver chooses to not enable anti-replay for an SA, then
the receiver SHOULD NOT negotiate ESN in an SA management protocol.
Use of ESN creates a need for the receiver to manage the anti-replay
window (in order to determine the correct value for the high-order
bits of the ESN, which are employed in the ICV computation), which is
generally contrary to the notion of disabling anti-replay for an SA.
So return an error if an ESN state with disabled anti replay detection
is inserted for now and add the extra treatment later if we need it.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As it is, we assign the outer modes output function to the dst entry
when we create the xfrm bundle. This leads to two problems on interfamily
scenarios. We might insert ipv4 packets into ip6_fragment when called
from xfrm6_output. The system crashes if we try to fragment an ipv4
packet with ip6_fragment. This issue was introduced with git commit
ad0081e4 (ipv6: Fragment locally generated tunnel-mode IPSec6 packets
as needed). The second issue is, that we might insert ipv4 packets in
netfilter6 and vice versa on interfamily scenarios.
With this patch we assign the inner mode output function to the dst entry
when we create the xfrm bundle. So xfrm4_output/xfrm6_output from the inner
mode is used and the right fragmentation and netfilter functions are called.
We switch then to outer mode with the output_finish functions.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPsec extended sequence numbers can be used only with the new
anti-replay window implementation. So check if the new implementation
is used if an esn state is inserted and return an error if it is not.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
On replay initialization, we compute the size of the replay
buffer to see if the replay window fits into the buffer.
This computation lacks a mutliplication by 8 because we need
the size in bit, not in byte. So we might return an error
even though the replay window would fit into the buffer.
This patch fixes this issue.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The IPsec extended sequence numbers are fully implemented just for
esp. So restrict the usage to esp until other protocols have
support too.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
In xfrm_new_ae() we may overwrite the allocated esn replay state
buffer with a wrong size. So check that the new size matches the
original allocated size and return an error if this is not the case.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we clone a xfrm state we have to assign the replay_esn
and the preplay_esn pointers to the state if we use the
new replay detection method. To this end, we add a
xfrm_replay_clone() function that allocates memory for
the replay detection and takes over the necessary values
from the original state.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
As it is, the replay check is just performed if the replay window of the
legacy implementation is nonzero. So we move the test on a nonzero replay
window inside the replay check functions to be sure we are testing for the
right implementation.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
We clone the child entry in skb_dst_pop before we call
skb_dst_drop(). Otherwise we might kill the child right
before we return it to the caller.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Crypto requests might return asynchronous. In this case we leave
the rcu protected region, so force a refcount on the skb's
destination entry before we enter the xfrm type input/output
handlers.
This fixes a crash when a route is deleted whilst sending IPsec
data that is transformed by an asynchronous algorithm.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We return a destination entry without refcount if a socket
policy is found in xfrm_lookup. This triggers a warning on
a negative refcount when freeeing this dst entry. So take
a refcount in this case to fix it.
This refcount was forgotten when xfrm changed to cache bundles
instead of policies for outgoing flows.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
This function should return 0 in case of error, 1 if OK
commit 452edd598f (xfrm: Return dst directly from xfrm_lookup())
got it wrong.
Reported-and-bisected-by: Michael Smith <msmith@cbnco.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a netlink based user interface to configure
esn and big anti-replay windows. The new netlink attribute
XFRMA_REPLAY_ESN_VAL is used to configure the new implementation.
If the XFRM_STATE_ESN flag is set, we use esn and support for big
anti-replay windows for the configured state. If this flag is not
set we use the new implementation with 32 bit sequence numbers.
A big anti-replay window can be configured in this case anyway.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds support for IPsec extended sequence numbers (esn)
as defined in RFC 4303. The bits to manage the anti-replay window
are based on a patch from Alex Badea.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
As it is, the anti-replay bitmap in struct xfrm_replay_state can
only accomodate 32 packets. Even though it is possible to configure
anti-replay window sizes up to 255 packets from userspace. So we
reject any packet with a sequence number within the configured window
but outside the bitmap. With this patch, we represent the anti-replay
window as a bitmap of variable length that can be accessed via the
new struct xfrm_replay_state_esn. Thus, we have no limit on the
window size anymore. To use the new anti-replay window implementantion,
new userspace tools are required. We leave the old implementation
untouched to stay in sync with old userspace tools.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
To support multiple versions of replay detection, we move the replay
detection functions to a separate file and make them accessible
via function pointers contained in the struct xfrm_replay.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
To support IPsec extended sequence numbers, we split the
output sequence numbers of xfrm_skb_cb in low and high order 32 bits
and we add the high order 32 bits to the input sequence numbers.
All users are updated accordingly.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now we have struct flowi4, flowi6, and flowidn for each address
family. And struct flowi is just a union of them all.
It might have been troublesome to convert flow_cache_uli_match() but
as it turns out this function is completely unused and therefore can
be simply removed.
Signed-off-by: David S. Miller <davem@davemloft.net>
Create two sets of port member accessors, one set prefixed by fl4_*
and the other prefixed by fl6_*
This will let us to create AF optimal flow instances.
It will work because every context in which we access the ports,
we have to be fully aware of which AF the flowi is anyways.
Signed-off-by: David S. Miller <davem@davemloft.net>
I intend to turn struct flowi into a union of AF specific flowi
structs. There will be a common structure that each variant includes
first, much like struct sock_common.
This is the first step to move in that direction.
Signed-off-by: David S. Miller <davem@davemloft.net>
Netlink message processing in the kernel is synchronous these days, the
session information can be collected when needed.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
