[PATCH net-next 0/3] {IPv4,xfrm} Add ESN support for AH

[Fan Du <fan.du@windriver.com>]

Hi,

This is initial Extended Sequence Number support for AH based on IPv4.
The rationale is totally by the RFC 4302, which states:

3.3.3.2.2.  Implicit Packet Padding and ESN

   If the ESN option is elected for an SA, then the high-order 32 bits
   of the ESN must be included in the ICV computation.  For purposes of
   ICV computation, these bits are appended (implicitly) immediately
   after the end of the payload, and before any implicit packet padding.

So we attach the high-order 32bits as a scatterlist right after the packet
payload to compute ICV value. 

Test:
I add a knob in iproute2/ip/xfrm_state.c to enable esn when setting SA,
which make it possible to test with-esn and without-esn scenarios, both
cases works ok with ping using packetsize(-s) from default to 32768.  

Fan Du (3):
  {IPv4,xfrm} Add Extended Sequence Number support for AH egress part
  {IPv4,xfrm} Add Extended Sequence Number support for AH ingress part
  xfrm: Don't prohibit AH from using ESN feature

 net/ipv4/ah4.c       |   49 ++++++++++++++++++++++++++++++++++++++++++-------
 net/xfrm/xfrm_user.c |    4 ----
 2 files changed, 42 insertions(+), 11 deletions(-)

-- 
1.7.9.5