sctp_rcv().

The goal is to hold the ref on the association/endpoint throughout the
state-machine process.  We accomplish like this:

  /* ref on the assoc/ep is taken during lookup */

  if owned_by_user(sk)
 	sctp_add_backlog(skb, sk);
  else
 	inqueue_push(skb, sk);

  /* drop the ref on the assoc/ep */

However, in sctp_add_backlog() we take the ref on assoc/ep and hold it
while the skb is on the backlog queue.  This allows us to get rid of the
sock_hold/sock_put in the lookup routines.

Now sctp_backlog_rcv() needs to account for potential association move.
In the unlikely event that association moved, we need to retest if the
new socket is locked by user.  If we don't this, we may have two packets
racing up the stack toward the same socket and we can't deal with it.
If the new socket is still locked, we'll just add the skb to its backlog
continuing to hold the ref on the association.  This get's rid of the
need to move packets from one backlog to another and it also safe in
case new packets arrive on the same backlog queue.

The last step, is to lock the new socket when we are moving the
association to it.  This is needed in case any new packets arrive on
the association when it moved.  We want these to go to the backlog since
we would like to avoid the race between this new packet and a packet
that may be sitting on the backlog queue of the old socket toward the
same association.
Signed-off-by: NVladislav Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>

Also fix some other cases where sk_err is not set for 1-1 style sockets.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>

I was working on the ipip/xfrm problem and as usual I get side-tracked by
other problems.

As part of an attempt to change the IPv4 protocol handler calling
convention I found that SCTP violated the existing convention.

It's returning non-zero values after freeing the skb.  This is doubly bad
as 1) the skb gets resubmitted; 2) the return value is interpreted as a
protocol number.

This patch changes those return values to zero.

IPv6 doesn't suffer from this problem because it uses a positive return
value as an indication for resubmission.  So the only effect of this patch
there is to increment the IPSTATS_MIB_INDELIVERS counter which IMHO is
the right thing to do.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NTsutomu Fujii <t-fujii@nb.jp.nec.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>

Validate and update the sk in sctp_rcv() to avoid the race where an
assoc/ep could move to a different socket after we get the sk, but before
the skb is added to the backlog.

Also migrate the skb's in backlog queue to new sk when doing a peeloff.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>

Do not release the reference to association/endpoint if an incoming skb is
added to backlog. Instead release it after the chunk is processed in
sctp_backlog_rcv().
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>

Keep the conntrack reference until policy checks have been performed for
IPsec NAT support. The reference needs to be dropped before a packet is
queued to avoid having the conntrack module unloadable.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support to set/get heartbeat interval, maximum number of
retransmissions, pathmtu, sackdelay time for a particular transport/
association/socket as per the latest SCTP sockets api draft11.
Signed-off-by: NFrank Filz <ffilz@us.ibm.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Also introduces a sysctl option to configure the receive buffer
accounting policy to be either at socket or association level.
Default is all the associations on the same socket share the
receive buffer.
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reduces skb size by 8 bytes on 64-bit.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implements sctp_connectx() as defined in the SCTP sockets API draft by
tunneling the request through a setsockopt().
Signed-off-by: NFrank Filz <ffilzlnx@us.ibm.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNeil Horman <nhorman@redhat.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com
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!