This patch adds a number of new IPsec audit events to meet the auditing
requirements of RFC4303.  This includes audit hooks for the following events:

 * Could not find a valid SA [sections 2.1, 3.4.2]
   . xfrm_audit_state_notfound()
   . xfrm_audit_state_notfound_simple()

 * Sequence number overflow [section 3.3.3]
   . xfrm_audit_state_replay_overflow()

 * Replayed packet [section 3.4.3]
   . xfrm_audit_state_replay()

 * Integrity check failure [sections 3.4.4.1, 3.4.4.2]
   . xfrm_audit_state_icvfail()

While RFC4304 deals only with ESP most of the changes in this patch apply to
IPsec in general, i.e. both AH and ESP.  The one case, integrity check
failure, where ESP specific code had to be modified the same was done to the
AH code for the sake of consistency.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes a number of small but potentially troublesome things in the
XFRM/IPsec code:

 * Use the 'audit_enabled' variable already in include/linux/audit.h
   Removed the need for extern declarations local to each XFRM audit fuction

 * Convert 'sid' to 'secid' everywhere we can
   The 'sid' name is specific to SELinux, 'secid' is the common naming
   convention used by the kernel when refering to tokenized LSM labels,
   unfortunately we have to leave 'ctx_sid' in 'struct xfrm_sec_ctx' otherwise
   we risk breaking userspace

 * Convert address display to use standard NIP* macros
   Similar to what was recently done with the SPD audit code, this also also
   includes the removal of some unnecessary memcpy() calls

 * Move common code to xfrm_audit_common_stateinfo()
   Code consolidation from the "less is more" book on software development

 * Proper spacing around commas in function arguments
   Minor style tweak since I was already touching the code
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This statistics is shown factor dropped by transformation
at /proc/net/xfrm_stat for developer.
It is a counter designed from current transformation source code
and defined as linux private MIB.

See Documentation/networking/xfrm_proc.txt for the detail.
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPv6 specific thing is wrongly removed from transformation at net-2.6.25.
This patch recovers it with current design.

o Update "path" of xfrm_dst since IPv6 transformation should
  care about routing changes. It is required by MIPv6 and
  off-link destined IPsec.
o Rename nfheader_len which is for non-fragment transformation used by
  MIPv6 to rt6i_nfheader_len as IPv6 name space.
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While merging the IPsec output path I moved the encapsulation output
operation to the top of the loop so that it sits outside of the locked
section.  Unfortunately in doing so it now sits in front of the space
check as well which could be a fatal error.

This patch rearranges the calls so that the space check happens as
the thing on the output path.

This patch also fixes an incorrect goto should the encapsulation output
fail.

Thanks to Kazunori MIYAZAWA for finding this bug.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The _find calls calculate the hash value using the
xfrm_state_hmask, without the xfrm_state_lock. But the
value of this mask can change in the _resize call under
the state_lock, so we risk to fail in finding the desired
entry in hash.

I think, that the hash value is better to calculate
under the state lock.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Further testing shows that my ICMP relookup patch can cause xfrm_lookup
to return zero on error which isn't very nice since it leads to the caller
dying on null pointer dereference.  The bug is due to not setting err
to ENOENT just before we leave xfrm_lookup in case of no policy.

This patch moves the err setting to where it should be.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC 4301 requires us to relookup ICMP traffic that does not match any
policies using the reverse of its payload.  This patch implements this
for ICMP traffic that originates from or terminates on localhost.

This is activated on outbound with the new policy flag XFRM_POLICY_ICMP,
and on inbound by the new state flag XFRM_STATE_ICMP.

On inbound the policy check is now performed by the ICMP protocol so
that it can repeat the policy check where necessary.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC 4301 requires us to relookup ICMP traffic that does not match any
policies using the reverse of its payload.  This patch adds the functions
xfrm_decode_session_reverse and xfrmX_policy_check_reverse so we can get
the reverse flow to perform such a lookup.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces an enum for bits in the flags argument of xfrm_lookup.
This is so that we can cram more information into it later.

Since all current users use just the values 0 and 1, XFRM_LOOKUP_WAIT has
been added with the value 1 << 0 to represent the current meaning of flags.

The test in __xfrm_lookup has been changed accordingly.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the xfrm_input_state helper function which returns the
current xfrm state being processed on the input path given an sk_buff.
This is currently only used by xfrm_input but will be used by ESP upon
asynchronous resumption.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

single list_head variable initialized with LIST_HEAD_INIT could almost
always can be replaced with LIST_HEAD declaration, this shrinks the code
and looks better.
Signed-off-by: NDenis Cheng <crquan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move dst entries to a namespace loopback to catch refcounting leaks.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When merging the input paths of IPsec I accidentally left a hard-coded
AF_INET for the state lookup call.  This broke IPv6 obviously.  This
patch fixes by getting the input callers to specify the family through
skb->cb.

Credit goes to Kazunori Miyazawa for diagnosing this and providing an
initial patch.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently the netmask/prefix-length of an IPsec SPD entry is not included in
any of the SPD related audit messages.  This can cause a problem when the
audit log is examined as the netmask/prefix-length is vital in determining
what network traffic is affected by a particular SPD entry.  This patch fixes
this problem by adding two additional fields, "src_prefixlen" and
"dst_prefixlen", to the SPD audit messages to indicate the source and
destination netmasks.  These new fields are only included in the audit message
when the netmask/prefix-length is less than the address length, i.e. the SPD
entry applies to a network address and not a host address.

Example audit message:

 type=UNKNOWN[1415] msg=audit(1196105849.752:25): auid=0 \
   subj=root:system_r:unconfined_t:s0-s0:c0.c1023 op=SPD-add res=1 \
   src=192.168.0.0 src_prefixlen=24 dst=192.168.1.0 dst_prefixlen=24

In addition, this patch also fixes a few other things in the
xfrm_audit_common_policyinfo() function.  The IPv4 string formatting was
converted to use the standard NIPQUAD_FMT constant, the memcpy() was removed
from the IPv6 code path and replaced with a typecast (the memcpy() was acting
as a slow, implicit typecast anyway), and two local variables were created to
make referencing the XFRM security context and selector information cleaner.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

2007/11/26, Patrick McHardy <kaber@trash.net>:
> How about also switching vmalloc/get_free_pages to GFP_ZERO
> and getting rid of the memset entirely while you're at it?
>

xfrm_hash: kmalloc + memset conversion to kzalloc
fix to avoid memset entirely.
Signed-off-by: NJoonwoo Park <joonwpark81@gmail.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After changeset:

	[NETFILTER]: Introduce NF_INET_ hook values

It always evaluates to NF_INET_POST_ROUTING.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for async resumptions on input.  To do so, the
transform would return -EINPROGRESS and subsequently invoke the
function xfrm_input_resume to resume processing.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The nhoff field isn't actually necessary in xfrm_input.  For tunnel
mode transforms we now throw away the output IP header so it makes no
sense to fill in the nexthdr field.  For transport mode we can now let
the function transport_finish do the setting and it knows where the
nexthdr field is.

The only other thing that needs the nexthdr field to be set is the
header extraction code.  However, we can simply move the protocol
extraction out of the generic header extraction.

We want to minimise the amount of info we have to carry around between
transforms as this simplifies the resumption process for async crypto.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently x->lastused is u64 which means that it cannot be
read/written atomically on all architectures.  David Miller observed
that the value stored in it is only an unsigned long which is always
atomic.

So based on his suggestion this patch changes the internal
representation from u64 to unsigned long while the user-interface
still refers to it as u64.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch releases the lock on the state before calling
x->type->input.  It also adds the lock to the spots where they're
currently needed.

Most of those places (all except mip6) are expected to disappear with
async crypto.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to the moving out of the replay processing on the output, this
patch moves the integrity stat collectin from x->type->input into
xfrm_input.

This would eventually allow transforms such as AH/ESP to be lockless.

The error value EBADMSG (currently unused in the crypto layer) is used
to indicate a failed integrity check.  In future this error can be
directly returned by the crypto layer once we switch to aead
algorithms.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As it is xfrm_input first collects a list of xfrm states on the stack
before storing them in the packet's security path just before it
returns.  For async crypto, this construction presents an obstacle
since we may need to leave the loop after each transform.

In fact, it's much easier to just skip the stack completely and always
store to the security path.  This is proven by the fact that this
patch actually shrinks the code.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As part of the work on asynchronous cryptographic operations, we need
to be able to resume from the spot where they occur.  As such, it
helps if we isolate them to one spot.

This patch moves most of the remaining family-specific processing into
the common input code.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for async resumptions on output.  To do so,
the transform would return -EINPROGRESS and subsequently invoke the
function xfrm_output_resume to resume processing.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As part of the work on asynchrnous cryptographic operations, we need
to be able to resume from the spot where they occur.  As such, it
helps if we isolate them to one spot.

This patch moves most of the remaining family-specific processing into
the common output code.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With inter-family transforms the inner mode differs from the outer
mode.  Attempting to handle both sides from the same function means
that it needs to handle both IPv4 and IPv6 which creates duplication
and confusion.

This patch separates the two parts on the input path so that each
function deals with one family only.

In particular, the functions xfrm4_extract_inut/xfrm6_extract_inut
moves the pertinent fields from the IPv4/IPv6 IP headers into a
neutral format stored in skb->cb.  This is then used by the inner mode
input functions to modify the inner IP header.  In this way the input
function no longer has to know about the outer address family.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RO mode is the only one that requires a locked output function.  So
it's easier to move the lock into that function rather than requiring
everyone else to run under the lock.

In particular, this allows us to move the size check into the output
function without causing a potential dead-lock should the ICMP error
somehow hit the same SA on transmission.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Half of the code in xfrm4_bundle_create and xfrm6_bundle_create are
common.  This patch extracts that logic and puts it into
xfrm_bundle_create.  The rest of it are then accessed through afinfo.

As a result this fixes the problem with inter-family transforms where
we treat every xfrm dst in the bundle as if it belongs to the top
family.

This patch also fixes a long-standing error-path bug where we may free
the xfrm states twice.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch moves the flow construction from the callers of
xfrm_dst_lookup into that function.  It also changes xfrm_dst_lookup
so that it takes an xfrm state as its argument instead of explicit
addresses.

This removes any address-specific logic from the callers of
xfrm_dst_lookup which is needed to correctly support inter-family
transforms.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we use x->props.header_len when resizing on output.
However, if we're resizing at all we might as well go the whole hog
and do it for the whole dst.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Many-many code in the kernel initialized the timer->function
and  timer->data together with calling init_timer(timer). There
is already a helper for this. Use it for networking code.

The patch is HUGE, but makes the code 130 lines shorter
(98 insertions(+), 228 deletions(-)).
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

alg_key_len is the length in bits of the key, not in bytes.

Best way to fix this is to move alg_len() function from net/xfrm/xfrm_user.c 
to include/net/xfrm.h, and to use it in xfrm_algo_clone()

alg_len() is renamed to xfrm_alg_len() because of its global exposition.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In include/net/xfrm.h we find :

#ifdef CONFIG_XFRM_MIGRATE
extern int km_migrate(struct xfrm_selector *sel, u8 dir, u8 type,
                      struct xfrm_migrate *m, int num_bundles);
...
#endif

We can also guard the function body itself in net/xfrm/xfrm_state.c
with same condition.

(Problem spoted by sparse checker)
make C=2 net/xfrm/xfrm_state.o
...
net/xfrm/xfrm_state.c:1765:5: warning: symbol 'km_migrate' was not declared. Should it be static?
...
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In several places the arguments to the xfrm_audit_start() function are
in the wrong order resulting in incorrect user information being
reported.  This patch corrects this by pacing the arguments in the
correct order.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently the IPsec protocol SPI values are written to the audit log in
network byte order which is different from almost all other values which
are recorded in host byte order.  This patch corrects this inconsistency
by writing the SPI values to the audit record in host byte order.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we get an error during the actual policy lookup we don't free the
original dst while the caller expects us to always free the original
dst in case of error.

This patch fixes that.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Andrew Morton reported that __xfrm_lookup generates this warning:

net/xfrm/xfrm_policy.c: In function '__xfrm_lookup':
net/xfrm/xfrm_policy.c:1449: warning: 'dst' may be used uninitialized in this function

This is because if policy->action is of an unexpected value then dst will
not be initialised.  Of course, in practice this should never happen since
the input layer xfrm_user/af_key will filter out all illegal values.  But
the compiler doesn't know that of course.

So this patch fixes this by taking the conservative approach and treat all
unknown actions the same as a blocking action.

Thanks to Andrew for finding this and providing an initial fix.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>