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: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

[NET]: Add common helper functions to convert IPv6/IPv4 address string to network address structure.

These helpers can be used in netfilter, cifs etc.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Based on patch by Jean Lorchat <lorchat@sfc.wide.ad.jp>.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

- Remove redundant code.  Pointed out by Brian Haley <brian.haley@hp.com>.
- Unify code paths with/without CONFIG_IPV6_MIP.
- Use NIP6_FMT for IPv6 address textual presentation.
- Fold long line.  Pointed out by David Miller <davem@davemloft.net>.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

First of all, if the xfrm_state only gets used for input
packets this entropy is a complete waste.

Secondly, it is often the case that a configuration loads
many rules (perhaps even dynamically) and they don't all
necessarily ever get used.

This get_random_bytes() call was showing up in the profiles
for xfrm_state inserts which is how I noticed this.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid 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: NDavid 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: NDavid 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: NDavid 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: NDavid 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: NDavid S. Miller <davem@davemloft.net>

It can use __xfrm{4,6}_addr_hash().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Besides the daddr, key the hash on family and reqid too.
Signed-off-by: NDavid 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: NDavid 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: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Support Mobile IPv6 extension headers sorting for two transformation policies.
Mobile IPv6 extension headers should be placed after IPsec
transport mode, but before transport AH when outbound.
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add sort functions to combine templates/states for IPsec.
Think of outbound transformation order we should be careful with transport AH
which must be the last of all transport ones.
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid 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: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid 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: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid 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: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Add Kconfig to support sub policy.
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ignore to report user-space for known mobility headers rejected by
destination options header transformation.
Mobile IPv6 specification (RFC3775) says that mobility header
is used with destination options header carrying home address option
only for binding update message. Other type message cannot be used
and node must drop it silently (and must not send binding error) if
receving such packet.
To achieve it, (1) application should use transformation policy and
wild-card states to catch binding update message prior other packets
(2) kernel doesn't report the reject to user-space not to send
binding error message by application.
This patch is for (2).
Based on MIPL2 kernel patch.

This patch was also written by: Ville Nuorvala <vnuorval@tcs.hut.fi>
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Report to user-space when home address option is rejected.
In receiving this message user-space application will send Mobile IPv6 binding
error. It is rate-limited by kernel.
Based on MIPL2 kernel patch.

This patch was also written by: Ville Nuorvala <vnuorval@tcs.hut.fi>
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid 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: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid 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: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Transformation support mobility header.
Based on MIPL2 kernel patch.
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Mobility header is built by user-space and sent through raw socket.
Kernel just extracts its type to flow.
Based on MIPL2 kernel patch.
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Like ICMPv6, mobility header is handled through raw socket.
In inbound case, check only whether ICMPv6 error should be sent as a reply
or not by kernel.
Based on MIPL2 kernel patch.

This patch was also written by: Ville Nuorvala <vnuorval@tcs.hut.fi>
This patch was also written by: Antti Tuominen <anttit@tcs.hut.fi>
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add Mobility header definition for Mobile IPv6.
Based on MIPL2 kernel patch.

This patch was also written by: Antti Tuominen <anttit@tcs.hut.fi>
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid 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: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add destination options header transformation for Mobile IPv6.
Based on MIPL2 kernel patch.

This patch was also written by: Ville Nuorvala <vnuorval@tcs.hut.fi>
Signed-off-by: NNoriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add routing header type 2 transformation for Mobile IPv6.
Based on MIPL2 kernel patch.
Signed-off-by: NNoriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: NMasahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>