The existing connection tracking subsystem in netfilter can only
handle ipv4.  There were basically two choices present to add
connection tracking support for ipv6.  We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.

In fact nf_conntrack is capable of working with any layer 3
protocol.

The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here.  For example, these issues include:

1) ICMPv6 handling, which is used for neighbour discovery in
   ipv6 thus some messages such as these should not participate
   in connection tracking since effectively they are like ARP
   messages

2) fragmentation must be handled differently in ipv6, because
   the simplistic "defrag, connection track and NAT, refrag"
   (which the existing ipv4 connection tracking does) approach simply
   isn't feasible in ipv6

3) ipv6 extension header parsing must occur at the correct spots
   before and after connection tracking decisions, and there were
   no provisions for this in the existing connection tracking
   design

4) ipv6 has no need for stateful NAT

The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete.  Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.
Signed-off-by: NYasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>

Fix unchecked __get_user that could be tricked into generating a
memory read on an arbitrary address.  The result of the read is not
returned directly but you may be able to divine some information about
it, or use the read to cause a crash on some architectures by reading
hardware state.  CAN-2004-2492.

Fix from Al Viro, ack from Dave Miller.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based on patch from David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: NDavid L Stevens <dlstevens@us.ibm.com>
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Support several new socket options / ancillary data:
  IPV6_RECVPKTINFO, IPV6_PKTINFO,
  IPV6_RECVHOPOPTS, IPV6_HOPOPTS,
  IPV6_RECVDSTOPTS, IPV6_DSTOPTS, IPV6_RTHDRDSTOPTS,
  IPV6_RECVRTHDR, IPV6_RTHDR,
  IPV6_RECVHOPOPTS, IPV6_HOPOPTS

Old semantics are preserved as IPV6_2292xxxx so that
we can maintain backward compatibility.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Due to changes to enforce checking interface bindings,
sockets did not see loopback packets bound for our local address
on our interface.

e.g.)
  When we ping6 fe80::1%eth0, skb->dev points loopback_dev while
  IP6CB(skb)->iif indicates eth0.

This patch fixes the issue by using appropriate incoming interface,
in the sense of scoping architecture.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Lots of places just needs the states, not even linux/tcp.h, where this
enum was, needs it.

This speeds up development of the refactorings as less sources are
rebuilt when things get moved from net/tcp.h.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

[IPV4/6]: Check if packet was actually delivered to a raw socket to decide whether to send an ICMP unreachable
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Take account of whether a socket is bound to a particular device when
selecting an IPv6 raw socket to receive a packet. Also perform this
check when receiving IPv6 packets with router alert options.
Signed-off-by: NAndrew McDonald <andrew@mcdonald.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When packets hit raw sockets the csum update isn't done yet, do it manually.
Packets can also reach rawv6_rcv on the output path through
ip6_call_ra_chain, in this case skb->ip_summed is CHECKSUM_NONE and this
codepath isn't executed.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When packets hit raw sockets the csum update isn't done yet, do it manually.
Packets can also reach rawv6_rcv on the output path through
ip6_call_ra_chain, in this case skb->ip_summed is CHECKSUM_NONE and this
codepath isn't executed.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In light of my recent patch to net/ipv4/udp.c that replaced the
spin_lock_irq calls on the receive queue lock with spin_lock_bh,
here is a similar patch for all other occurences of spin_lock_irq
on receive/error queue locks in IPv4 and IPv6.

In these stacks, we know that they can only be entered from user
or softirq context.  Therefore it's safe to disable BH only.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I made a mistake in my last patch to the raw socket checksum code.
I used the value of inet->cork.length as the length of the payload.
While this works with normal packets, it breaks down when IPsec is
present since the cork length includes the extension header length.

So here is a patch to fix the length calculations.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While looking at this problem I noticed that IPv6 was sometimes
looking at inet->recverr which is bogus.  Here is a patch to
correct that and use np->recverr.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Acked-by: NHideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

So here is a patch that introduces skb_store_bits -- the opposite of
skb_copy_bits, and uses them to read/write the csum field in rawv6.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!