linux/net/xfrm
Lorenzo Colitti 077fbac405 net: xfrm: support setting an output mark.
On systems that use mark-based routing it may be necessary for
routing lookups to use marks in order for packets to be routed
correctly. An example of such a system is Android, which uses
socket marks to route packets via different networks.

Currently, routing lookups in tunnel mode always use a mark of
zero, making routing incorrect on such systems.

This patch adds a new output_mark element to the xfrm state and
a corresponding XFRMA_OUTPUT_MARK netlink attribute. The output
mark differs from the existing xfrm mark in two ways:

1. The xfrm mark is used to match xfrm policies and states, while
   the xfrm output mark is used to set the mark (and influence
   the routing) of the packets emitted by those states.
2. The existing mark is constrained to be a subset of the bits of
   the originating socket or transformed packet, but the output
   mark is arbitrary and depends only on the state.

The use of a separate mark provides additional flexibility. For
example:

- A packet subject to two transforms (e.g., transport mode inside
  tunnel mode) can have two different output marks applied to it,
  one for the transport mode SA and one for the tunnel mode SA.
- On a system where socket marks determine routing, the packets
  emitted by an IPsec tunnel can be routed based on a mark that
  is determined by the tunnel, not by the marks of the
  unencrypted packets.
- Support for setting the output marks can be introduced without
  breaking any existing setups that employ both mark-based
  routing and xfrm tunnel mode. Simply changing the code to use
  the xfrm mark for routing output packets could xfrm mark could
  change behaviour in a way that breaks these setups.

If the output mark is unspecified or set to zero, the mark is not
set or changed.

Tested: make allyesconfig; make -j64
Tested: https://android-review.googlesource.com/452776
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2017-08-11 07:03:00 +02:00
..
Kconfig Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2017-02-16 21:25:49 -05:00
Makefile xfrm: fix xfrm_dev_event() missing when compile without CONFIG_XFRM_OFFLOAD 2017-06-07 08:16:27 +02:00
xfrm_algo.c xfrm: use IS_ENABLED() instead of checking for built-in or module 2016-09-10 21:19:11 -07:00
xfrm_device.c net: xfrm: support setting an output mark. 2017-08-11 07:03:00 +02:00
xfrm_hash.c net: allow GFP_HIGHMEM in __vmalloc() 2010-11-21 10:04:04 -08:00
xfrm_hash.h xfrm: use "unsigned int" in __xfrm6_pref_hash() 2017-03-24 07:03:12 +01:00
xfrm_input.c xfrm: Clear RX SKB secpath xfrm_offload 2017-08-02 11:00:15 +02:00
xfrm_ipcomp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-04 13:48:30 -05:00
xfrm_output.c net: xfrm: support setting an output mark. 2017-08-11 07:03:00 +02:00
xfrm_policy.c net: xfrm: support setting an output mark. 2017-08-11 07:03:00 +02:00
xfrm_proc.c proc: Reduce cache miss in xfrm_statistics_seq_show 2016-09-30 01:50:45 -04:00
xfrm_replay.c xfrm: Add xfrm_replay_overflow functions for offloading 2017-04-14 10:07:01 +02:00
xfrm_state.c xfrm: Auto-load xfrm offload modules 2017-08-02 11:00:15 +02:00
xfrm_sysctl.c net: xfrm: Change u32 sysctl entries to use proc_douintvec 2016-09-07 23:17:53 -07:00
xfrm_user.c net: xfrm: support setting an output mark. 2017-08-11 07:03:00 +02:00