skb_push updates and returns skb->data, so we can just call
skb_reset_network_header after the call to skb_push.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

draft-nikander-esp-beet-mode-07.txt is not entirely clear on how the length
value of the pseudo header should be calculated, it states "The Header Length
field contains the length of the pseudo header, IPv4 options, and padding in
8 octets units.", but also states "Length in octets (Header Len + 1) * 8".
draft-nikander-esp-beet-mode-08-pre1.txt [1] clarifies this, the header length
should not include the first 8 byte.

This change affects backwards compatibility, but option encapsulation didn't
work until very recently anyway.

[1] http://users.piuha.net/jmelen/BEET/draft-nikander-esp-beet-mode-08-pre1.txtSigned-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Beet mode looks for the beet pseudo header after the outer IP header,
which is wrong since that is followed by the ESP header. Additionally
it needs to adjust the packet length after removing the pseudo header
and point the data pointer to the real data location.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Beet mode decapsulation fails to properly set up the skb pointers, which
only works by accident in combination with CONFIG_NETFILTER, since in that
case the skb is fixed up in xfrm4_input before passing it to the netfilter
hooks.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

draft-nikander-esp-beet-mode-07.txt states "The padding MUST be filled
with NOP options as defined in Internet Protocol [1] section 3.1
Internet header format.", so do that.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Beet mode calculates an incorrect value for the transport header location
when IP options are present, resulting in encapsulation errors.

The correct location is 4 or 8 bytes before the end of the original IP
header, depending on whether the pseudo header is padded.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces the BEET mode (Bound End-to-End Tunnel) with as
specified by the ietf draft at the following link:

http://www.ietf.org/internet-drafts/draft-nikander-esp-beet-mode-06.txt

The patch provides only single family support (i.e. inner family =
outer family).
Signed-off-by: NDiego Beltrami <diego.beltrami@gmail.com>
Signed-off-by: NMiika Komu     <miika@iki.fi>
Signed-off-by: NHerbert Xu     <herbert@gondor.apana.org.au>
Signed-off-by: NAbhinav Pathak <abhinav.pathak@hiit.fi>
Signed-off-by: NJeff Ahrenholz <ahrenholz@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>