If SHUTDOWN is received in SHUTDOWN-PENDING state, enpoint should enter
the SHUTDOWN-RECEIVED state and check the Cumulative TSN Ack field of
the SHUTDOWN chunk (RFC 4960 Section 9.2). If the SHUTDOWN chunk can
acknowledge all of the send DATA chunks, SHUTDOWN-ACK should be sent.

But now endpoint just silently discarded the SHUTDOWN chunk.

SHUTDOWN received in SHUTDOWN-PENDING state can happend when the last
SACK is lost by network, or the SHUTDOWN chunk can acknowledge all of
the received DATA chunks. The packet sequence(SACK lost) is like this:

Endpoint A                       Endpoint B       ULP
(ESTABLISHED)                    (ESTABLISHED)

               <-----------      DATA
                                             <--- shutdown
                                 Enter SHUTDOWN-PENDING state
  SACK         ----lost---->

  SHUTDOWN(*1) ------------>

               <-----------      SHUTDOWN-ACK

 (*1) silently discarded now.

This patch fix to handle SHUTDOWN in SHUTDOWN-PENDING state as the same
as ESTABLISHED state.
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC 4960: Section 9.2
The sender of the SHUTDOWN MAY also start an overall guard timer
'T5-shutdown-guard' to bound the overall time for the shutdown
sequence.  At the expiration of this timer, the sender SHOULD abort
the association by sending an ABORT chunk.  If the 'T5-shutdown-
guard' timer is used, it SHOULD be set to the recommended value of 5
times 'RTO.Max'.

The timer 'T5-shutdown-guard' is used to counter the overall time
for shutdown sequence, and it's start by the sender of the SHUTDOWN.
So timer 'T5-shutdown-guard' should be start when we send the first
SHUTDOWN chunk and enter the SHUTDOWN-SENT state, not start when we
receipt of the SHUTDOWN primitive and enter SHUTDOWN-PENDING state.

If 'T5-shutdown-guard' timer is start at SHUTDOWN-PENDING state, the
association may be ABORT while data is still transmitting.
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>

I was notified by Randy Stewart that lksctp claims to be
"the reference implementation".  First of all, "the
refrence implementation" was the original implementation
of SCTP in usersapce written ty Randy and a few others.
Second, after looking at the definiton of 'reference implementation',
we don't really meet the requirements.
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>

   C4)  Both ASCONF and ASCONF-ACK Chunks MUST NOT be sent in any SCTP
        state except ESTABLISHED, SHUTDOWN-PENDING, SHUTDOWN-RECEIVED,
        and SHUTDOWN-SENT.
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements the receive path needed to process authenticated
chunks.  Add ability to process the AUTH chunk and handle edge cases
for authenticated COOKIE-ECHO as well.
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While processing OOTB chunks as well as chunks with an invalid
length of 0, it was possible to SCTP to get wedged inside an
infinite loop because we didn't catch the condition correctly,
or didn't mark the packet for discard correctly.
This work is based on original findings and work by
Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>

Recent gcc versions emit warnings when unsigned variables are
compared < 0 or >= 0.
Signed-off-by: NBill Nottingham <notting@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Spring cleaning time...

There seems to be a lot of places in the network code that have
extra bogus semicolons after conditionals.  Most commonly is a
bogus semicolon after: switch() { }
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Consider the chunk as Out-of-the-Blue if we don't have
an endpoint.  Otherwise discard it as before.
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I noticed an insane high density of repeated characters fixable by a
simple regular expression:

  % s/{.fn = \([^,]*\),[[:space:]]\+\(\\\n[[:space:]]\+\)\?.name = "\1"}/TYPE_SCTP_FUNC(\1)/g

(NOTE: the .name for .fn = sctp_sf_do_9_2_start_shutdown didn't match)
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Discard an unexpected chunk in CLOSED state rather can calling BUG().
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
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>

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!