Add checksum default defines for mobility header(MH) which
goes through raw socket. As the result kernel's behavior is
to handle MH checksum as default.

This patch also removes verifying inbound MH checksum at
mip6_mh_filter() since it did not consider user specified
checksum offset and was redundant check with raw socket code.
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>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

kbuild explicitly includes this at build time.
Signed-off-by: NDave Jones <davej@redhat.com>

- 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>

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>

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 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>