This patch adds support for virtual xfrm interfaces.
Packets that are routed through such an interface
are guaranteed to be IPsec transformed or dropped.
It is a generic virtual interface that ensures IPsec
transformation, no need to know what happens behind
the interface. This means that we can tunnel IPv4 and
IPv6 through the same interface and support all xfrm
modes (tunnel, transport and beet) on it.
Co-developed-by: NLorenzo Colitti <lorenzo@google.com>
Co-developed-by: NBenedict Wong <benedictwong@google.com>
Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NBenedict Wong <benedictwong@google.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Acked-by: NShannon Nelson <shannon.nelson@oracle.com>
Tested-by: NBenedict Wong <benedictwong@google.com>
Tested-by: NAntony Antony <antony@phenome.org>
Reviewed-by: NEyal Birger <eyal.birger@gmail.com>

We already support setting an output mark at the xfrm_state,
unfortunately this does not support the input direction and
masking the marks that will be applied to the skb. This change
adds support applying a masked value in both directions.

The existing XFRMA_OUTPUT_MARK number is reused for this purpose
and as it is now bi-directional, it is renamed to XFRMA_SET_MARK.

An additional XFRMA_SET_MARK_MASK attribute is added for setting the
mask. If the attribute mask not provided, it is set to 0xffffffff,
keeping the XFRMA_OUTPUT_MARK existing 'full mask' semantics.
Co-developed-by: NTobias Brunner <tobias@strongswan.org>
Co-developed-by: NEyal Birger <eyal.birger@gmail.com>
Co-developed-by: NLorenzo Colitti <lorenzo@google.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NTobias Brunner <tobias@strongswan.org>
Signed-off-by: NEyal Birger <eyal.birger@gmail.com>
Signed-off-by: NLorenzo Colitti <lorenzo@google.com>

A recent commit introduced a new struct xfrm_trans_cb
that is used with the sk_buff control buffer. Unfortunately
it placed the structure in front of the control buffer and
overlooked that the IPv4/IPv6 control buffer is still needed
for some layer 4 protocols. As a result the IPv4/IPv6 control
buffer is overwritten with this structure. Fix this by setting
a apropriate header in front of the structure.

Fixes acf568ee ("xfrm: Reinject transport-mode packets ...")
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Kmem caches aren't relocated once set up.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

We do not need locking in xfrm_trans_queue because it is designed
to use per-CPU buffers.  However, the original code incorrectly
used skb_queue_tail which takes the lock.  This patch switches
it to __skb_queue_tail instead.
Reported-and-tested-by: NArtem Savkov <asavkov@redhat.com>
Fixes: acf568ee ("xfrm: Reinject transport-mode packets...")
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

This is an old bugbear of mine:

https://www.mail-archive.com/netdev@vger.kernel.org/msg03894.html

By crafting special packets, it is possible to cause recursion
in our kernel when processing transport-mode packets at levels
that are only limited by packet size.

The easiest one is with DNAT, but an even worse one is where
UDP encapsulation is used in which case you just have to insert
an UDP encapsulation header in between each level of recursion.

This patch avoids this problem by reinjecting tranport-mode packets
through a tasklet.

Fixes: b05e1066 ("[IPV4/6]: Netfilter IPsec input hooks")
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Code path when (encap_type < 0) does not verify the state is valid
before progressing.

This will result in a crash if, for instance, x->km.state ==
XFRM_STATE_ACQ.

Fixes: 7785bba2 ("esp: Add a software GRO codepath")
Signed-off-by: NAviv Heller <avivh@mellanox.com>
Signed-off-by: NYevgeny Kliteynik <kliteyn@mellanox.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

x is already initialized to the same value, above.
Signed-off-by: NAviv Heller <avivh@mellanox.com>
Signed-off-by: NYevgeny Kliteynik <kliteyn@mellanox.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

syzbot reports:
BUG: KASAN: use-after-free in __xfrm_state_lookup+0x695/0x6b0
Read of size 4 at addr ffff8801d434e538 by task syzkaller647520/2991
[..]
__xfrm_state_lookup+0x695/0x6b0 net/xfrm/xfrm_state.c:833
xfrm_state_lookup+0x8a/0x160 net/xfrm/xfrm_state.c:1592
xfrm_input+0x8e5/0x22f0 net/xfrm/xfrm_input.c:302

The use-after-free is the ipv4 destination address, which points
to an skb head area that has been reallocated:
  pskb_expand_head+0x36b/0x1210 net/core/skbuff.c:1494
  __pskb_pull_tail+0x14a/0x17c0 net/core/skbuff.c:1877
  pskb_may_pull include/linux/skbuff.h:2102 [inline]
  xfrm_parse_spi+0x3d3/0x4d0 net/xfrm/xfrm_input.c:170
  xfrm_input+0xce2/0x22f0 net/xfrm/xfrm_input.c:291

so the real bug is that xfrm_parse_spi() uses pskb_may_pull, but
for now do smaller workaround that makes xfrm_input fetch daddr
after spi parsing.
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Can be reproduced with LTP tests:
  # icmp-uni-vti.sh -p ah -a sha256 -m tunnel -S fffffffe -k 1 -s 10

IPv4:
  RIP: 0010:xfrm_input+0x7f9/0x870
  ...
  Call Trace:
  <IRQ>
  vti_input+0xaa/0x110 [ip_vti]
  ? skb_free_head+0x21/0x40
  vti_rcv+0x33/0x40 [ip_vti]
  xfrm4_ah_rcv+0x33/0x60
  ip_local_deliver_finish+0x94/0x1e0
  ip_local_deliver+0x6f/0xe0
  ? ip_route_input_noref+0x28/0x50
  ...

  # icmp-uni-vti.sh -6 -p ah -a sha256 -m tunnel -S fffffffe -k 1 -s 10
IPv6:
  RIP: 0010:xfrm_input+0x7f9/0x870
  ...
  Call Trace:
  <IRQ>
  xfrm6_rcv_tnl+0x3c/0x40
  vti6_rcv+0xd5/0xe0 [ip6_vti]
  xfrm6_ah_rcv+0x33/0x60
  ip6_input_finish+0xee/0x460
  ip6_input+0x3f/0xb0
  ip6_rcv_finish+0x45/0xa0
  ipv6_rcv+0x34b/0x540

xfrm_input() invokes xfrm_rcv_cb() -> vti_rcv_cb(), the last callback
might call skb_scrub_packet(), which in turn can reset secpath.

Fix it by adding a check that skb->sp is not NULL.

Fixes: 7e9e9202 ("xfrm: Clear RX SKB secpath xfrm_offload")
Signed-off-by: NAlexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

In conjunction with crypto offload [1], removing the ESP trailer by
hardware can potentially improve the performance by avoiding (1) a
cache miss incurred by reading the nexthdr field and (2) the necessity
to calculate the csum value of the trailer in order to keep skb->csum
valid.

This patch introduces the changes to the xfrm stack and merely serves
as an infrastructure. Subsequent patch to mlx5 driver will put this to
a good use.

[1] https://www.mail-archive.com/netdev@vger.kernel.org/msg175733.htmlSigned-off-by: NYossi Kuperman <yossiku@mellanox.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

If an incoming packet undergoes XFRM crypto-offload, its secpath is
filled with xfrm_offload struct denoting offload information.

If the SKB is then forwarded to a device which supports crypto-
offload, the stack wrongfully attempts to offload it (even though
the output SA may not exist on the device) due to the leftover
secpath xo.

Clear the ingress xo by zeroizing secpath->olen just before
delivering the decapsulated packet to the network stack.

Fixes: d77e38e6 ("xfrm: Add an IPsec hardware offloading API")
Signed-off-by: NIlan Tayari <ilant@mellanox.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In xfrm_input() when called from GRO, async == 0, and we end up
skipping the processing in xfrm4_transport_finish(). GRO path will
always skip the NF_HOOK, so we don't need the special-case for
!NETFILTER during GRO processing.

Fixes: 7785bba2 ("esp: Add a software GRO codepath")
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

On IPsec hardware offloading, we already get a secpath with
valid state attached when the packet enters the GRO handlers.
So check for hardware offload and skip the state lookup in this
case.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

This patch adds all the bits that are needed to do
IPsec hardware offload for IPsec states and ESP packets.
We add xfrmdev_ops to the net_device. xfrmdev_ops has
function pointers that are needed to manage the xfrm
states in the hardware and to do a per packet
offloading decision.

Joint work with:
Ilan Tayari <ilant@mellanox.com>
Guy Shapiro <guysh@mellanox.com>
Yossi Kuperman <yossiku@mellanox.com>
Signed-off-by: NGuy Shapiro <guysh@mellanox.com>
Signed-off-by: NIlan Tayari <ilant@mellanox.com>
Signed-off-by: NYossi Kuperman <yossiku@mellanox.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

This patch adds GRO ifrastructure and callbacks for ESP on
ipv4 and ipv6.

In case the GRO layer detects an ESP packet, the
esp{4,6}_gro_receive() function does a xfrm state lookup
and calls the xfrm input layer if it finds a matching state.
The packet will be decapsulated and reinjected it into layer 2.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

We need to keep per packet offloading informations across
the layers. So we extend the sec_path to carry these for
the input and output offload codepath.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

We need it in the ESP offload handlers, so export it.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Add a new helper to set the secpath to the skb.
This avoids code duplication, as this is used
in multiple places.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Nothing writes to these structures (the module owner was not used).

While at it, size xfrm_input_afinfo[] by the highest existing xfrm family
(INET6), not AF_MAX.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

This patch adds a dummy network device so that we can
use gro_cells for IPsec GRO. With this, we handle IPsec
GRO with no impact on the generic networking code.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Running LTP 'icmp-uni-basic.sh -6 -p ipcomp -m tunnel' test over
openvswitch + veth can trigger kernel panic:

  BUG: unable to handle kernel NULL pointer dereference
  at 00000000000000e0 IP: [<ffffffff8169d1d2>] xfrm_input+0x82/0x750
  ...
  [<ffffffff816d472e>] xfrm6_rcv_spi+0x1e/0x20
  [<ffffffffa082c3c2>] xfrm6_tunnel_rcv+0x42/0x50 [xfrm6_tunnel]
  [<ffffffffa082727e>] tunnel6_rcv+0x3e/0x8c [tunnel6]
  [<ffffffff8169f365>] ip6_input_finish+0xd5/0x430
  [<ffffffff8169fc53>] ip6_input+0x33/0x90
  [<ffffffff8169f1d5>] ip6_rcv_finish+0xa5/0xb0
  ...

It seems that tunnel.ip6 can have garbage values and also dereferenced
without a proper check, only tunnel.ip4 is being verified. Fix it by
adding one more if block for AF_INET6 and initialize tunnel.ip6 with NULL
inside xfrm6_rcv_spi() (which is similar to xfrm4_rcv_spi()).

Fixes: 049f8e2e ("xfrm: Override skb->mark with tunnel->parm.i_key in xfrm_input")
Signed-off-by: NAlexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

A crash is observed when a decrypted packet is processed in receive
path. get_rps_cpus() tries to dereference the skb->dev fields but it
appears that the device is freed from the poison pattern.

[<ffffffc000af58ec>] get_rps_cpu+0x94/0x2f0
[<ffffffc000af5f94>] netif_rx_internal+0x140/0x1cc
[<ffffffc000af6094>] netif_rx+0x74/0x94
[<ffffffc000bc0b6c>] xfrm_input+0x754/0x7d0
[<ffffffc000bc0bf8>] xfrm_input_resume+0x10/0x1c
[<ffffffc000ba6eb8>] esp_input_done+0x20/0x30
[<ffffffc0000b64c8>] process_one_work+0x244/0x3fc
[<ffffffc0000b7324>] worker_thread+0x2f8/0x418
[<ffffffc0000bb40c>] kthread+0xe0/0xec

-013|get_rps_cpu(
     |    dev = 0xFFFFFFC08B688000,
     |    skb = 0xFFFFFFC0C76AAC00 -> (
     |      dev = 0xFFFFFFC08B688000 -> (
     |        name =
"......................................................
     |        name_hlist = (next = 0xAAAAAAAAAAAAAAAA, pprev =
0xAAAAAAAAAAA

Following are the sequence of events observed -

- Encrypted packet in receive path from netdevice is queued
- Encrypted packet queued for decryption (asynchronous)
- Netdevice brought down and freed
- Packet is decrypted and returned through callback in esp_input_done
- Packet is queued again for process in network stack using netif_rx

Since the device appears to have been freed, the dereference of
skb->dev in get_rps_cpus() leads to an unhandled page fault
exception.

Fix this by holding on to device reference when queueing packets
asynchronously and releasing the reference on call back return.

v2: Make the change generic to xfrm as mentioned by Steffen and
update the title to xfrm
Suggested-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NJerome Stanislaus <jeromes@codeaurora.org>
Signed-off-by: NSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Increment the LINUX_MIB_XFRMINSTATEMODEERROR statistic counter
to notify about dropped packets if we fail to fetch a inner mode.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

This change makes it so that if a tunnel is defined we just use the mark
from the tunnel instead of the mark from the skb header.  By doing this we
can avoid the need to set skb->mark inside of the tunnel receive functions.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

Check x->km.state with XFRM_STATE_ACQ only when state is not
XFRM_STAT_VALID, not everytime
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

If xfrm_*_register_afinfo failed since xfrm_*_afinfo[afinfo->family] had the
value, return the -EEXIST, not -ENOBUFS
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

https://bugzilla.kernel.org/show_bug.cgi?id=95211

Commit 70be6c91
("xfrm: Add xfrm_tunnel_skb_cb to the skb common buffer") added check
which dereferences ->outer_mode too early but larval SAs don't have
this pointer set (yet). So check for tunnel stuff later.

Mike Noordermeer reported this bug and patiently applied all the debugging.

Technically this is remote-oops-in-interrupt-context type of thing.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000034
IP: [<ffffffff8150dca2>] xfrm_input+0x3c2/0x5a0
	...
[<ffffffff81500fc6>] ? xfrm4_esp_rcv+0x36/0x70
[<ffffffff814acc9a>] ? ip_local_deliver_finish+0x9a/0x200
[<ffffffff81471b83>] ? __netif_receive_skb_core+0x6f3/0x8f0
	...

RIP  [<ffffffff8150dca2>] xfrm_input+0x3c2/0x5a0
Kernel panic - not syncing: Fatal exception in interrupt
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

IPv6 can be build as a module, so we need mechanism to access
the address family dependent callback functions properly.
Therefore we introduce xfrm_input_afinfo, similar to that
what we have for the address family dependent part of
policies and states.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

IPsec vti_rcv needs to remind the tunnel pointer to
check it later at the vti_rcv_cb callback. So add
this pointer to the IPsec common buffer, initialize
it and check it to avoid transport state matching of
a tunneled packet.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

This patch add an IPsec protocol multiplexer. With this
it is possible to add alternative protocol handlers as
needed for IPsec virtual tunnel interfaces.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

This patch clean up some checkpatch errors like this:
ERROR: "foo * bar" should be "foo *bar"
ERROR: "(foo*)" should be "(foo *)"
Signed-off-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

When host ping its peer, ICMP echo request packet triggers IPsec
policy, then host negotiates SA secret with its peer. After IKE
installed SA for OUT direction, but before SA for IN direction
installed, host get ICMP echo reply from its peer. At the time
being, the SA state for IN direction could be XFRM_STATE_ACQ,
then the received packet will be dropped after adding
LINUX_MIB_XFRMINSTATEINVALID statistic.

Adding a LINUX_MIB_XFRMACQUIREERROR statistic counter for such
scenario when SA in larval state is much clearer for user than
LINUX_MIB_XFRMINSTATEINVALID which indicates the SA is totally
bad.
Signed-off-by: NFan Du <fan.du@windriver.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

ESN for esp is defined in RFC 4303. This RFC assumes that the
sequence number counters are always up to date. However,
this is not true if an async crypto algorithm is employed.

If the sequence number counters are not up to date on sequence
number check, we may incorrectly update the upper 32 bit of
the sequence number. This leads to a DOS.

We workaround this by comparing the upper sequence number,
(used for authentication) with the upper sequence number
computed after the async processing. We drop the packet
if these numbers are different.

To do this, we introduce a recheck function that does this
check in the ESN case.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When asyncronous crypto algorithms are used, there might be many
packets that passed the xfrm replay check, but the replay advance
function is not called yet for these packets. So the replay check
function would accept a replay of all of these packets. Also the
system might crash if there are more packets in async processing
than the size of the anti replay window, because the replay advance
function would try to update the replay window beyond the bounds.

This pach adds a second replay check after resuming from the async
processing to fix these issues.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid 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: NSteffen Klassert <steffen.klassert@secunet.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid 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: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid 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: NSteffen Klassert <steffen.klassert@secunet.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>