Every time SCTP creates a temporary association, the stack hashes it,
puts it on a list of endpoint associations and increments the backlog.
However, the lifetime of a temporary association is the processing time
of a current packet and it's destroyed after that. In fact, we don't
really want anyone else finding this association. There is no reason to
do this extra work.
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>

Make SCTP 1-1 style and peeled-off associations behave like TCP when
setting IP id. In both cases, we set the inet_sk(sk)->daddr and initialize
inet_sk(sk)->id to a random value.
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 was looking at a RHEL5 bug report involving Xen and SCTP
(https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=212550).
It turns out that SCTP wasn't written to handle skb fragments at
all.  The absence of any calls to skb_may_pull is testament to
that.

It just so happens that Xen creates fragmented packets more often
than other scenarios (header & data split when going from domU to
dom0).  That's what caused this bug to show up.

Until someone has the time sits down and audits the entire net/sctp
directory, here is a conservative and safe solution that simply
linearises all packets on input.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As ip6_route_output() never returns NULL, error checking must be done by
looking at dst->error in stead of comparing dst against NULL.
Signed-off-by: NVille Nuorvala <vnuorval@tcs.hut.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NVille Nuorvala <vnuorval@tcs.hut.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Show the true receive buffer usage.
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>

When doing receiver buffer accounting, we always used skb->truesize.
This is problematic when processing bundled DATA chunks because for
every DATA chunk that could be small part of one large skb, we would
charge the size of the entire skb.  The new approach is to store the
size of the DATA chunk we are accounting for in the sctp_ulpevent
structure and use that stored value for accounting.
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>

We only need the timestamp on COOKIE-ECHO chunks, so instead of always
timestamping every SCTP packet, let common code timestamp if the socket
option is set.  For COOKIE-ECHO, simply get the time of day if we don't
have a timestamp.  This introduces a small possibility that the cookie
may be considered expired, but it will be renegotiated.
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>

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>

Currently if the sender is sending small messages, it can cause a receiver
to run out of receive buffer space even when the advertised receive window
is still open and results in packet drops and retransmissions. Including
a overhead while updating the sender's view of peer receive window will
reduce the chances of receive buffer space overshooting the receive window.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This allows more aggressive bundling of chunks when sending small
messages.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
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>

This patch contains the following cleanups:
- make the following needlessly global function static:
  - socket.c: sctp_apply_peer_addr_params()
- add proper prototypes for the several global functions in
  include/net/sctp/sctp.h

Note that this fixes wrong prototypes for the following functions:
- sctp_snmp_proc_exit()
- sctp_eps_proc_exit()
- sctp_assocs_proc_exit()

The latter was spotted by the GNU C compiler and reported
by David Woodhouse.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change sctp globals to __read_mostly.
Signed-off-by: NBrian Haley <brian.haley@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Function sk_filter() is called from tcp_v{4,6}_rcv() functions with arg
needlock = 0, while socket is not locked at that moment. In order to avoid
this and similar issues in the future, use rcu for sk->sk_filter field read
protection.
Signed-off-by: NDmitry Mishin <dim@openvz.org>
Signed-off-by: NAlexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: NKirill Korotaev <dev@openvz.org>

The SCTP sysctl entries are displayed in milliseconds, but stored
internally in jiffies. This results in multiple levels of msecs to
jiffies conversion and as a result produces a truncation error. This
patch makes things consistent in that we store and display defaults
in milliseconds and only convert once for use by association.
This patch also adds some sane min/max values so that we don't go off
the deep end.
Signed-off-by: NVladislav Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No need to do multiple dereferences - sk->sk_socket->file->f_flags
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During accept/peeloff we try to copy the list of bound addresses from
the original endpoint to the new one. However, we forgot to set the flag
to say that IPv6 is allowed on the new endpoint.
Signed-off-by: NVladislav Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch cleans up the "nomem" conditions that may occur during the
processing by the state machine functions. In most cases we delay adding
side-effect commands until all memory allocations are done.
Signed-off-by: NVladislav Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds more statistics info under /proc/net/sctp/snmp
that should be useful for debugging. The additional events that
are counted now include timer expirations, retransmits, packet
and data chunk discards.

The Data chunk discards include all the cases where a data chunk
is discarded including high tsn, bad stream, dup tsn and the most
useful one(out of receive buffer/rwnd).

Also moved the SCTP MIB data structures from the generic include
directories to include/sctp/sctp.h.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch converts SCTP to use the new HMAC template and hash interface.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the recent fix, the callers of sctp_primitive_ABORT()
need to create an ABORT chunk and pass it as an argument rather
than msghdr that was passed earlier.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sctp_make_abort_user() now takes the msg_len along with the msg
so that we don't have to recalculate the bytes in iovec.
It also uses memcpy_fromiovec() so that we don't go beyond the
length allocated.

It is good to have this fix even if verify_iovec() is fixed to
return error on overflow.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This implements Rules D1 and D4 of Sec 4.3 in the ADDIP draft.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently there is a code path in sctp_eat_data() where it is possible
to set this flag even when we are dropping this chunk.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements Path Initialization procedure as described in
Sec 2.36 of RFC4460.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This prevents a race between the close of a socket and receive of an
incoming packet.
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>

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

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

sizeof(pointer) != sizeof(array)...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the event that our entire receive buffer is full with a series of
chunks that represent a single gap-ack, and then we accept a chunk
(or chunks) that fill in the gap between the ctsn and the first gap,
we renege chunks from the end of the buffer, which effectively does
nothing but move our gap to the end of our received tsn stream. This
does little but move our missing tsns down stream a little, and, if the
sender is sending sufficiently large retransmit frames, the result is a
perpetual slowdown which can never be recovered from, since the only
chunk that can be accepted to allow progress in the tsn stream necessitates
that a new gap be created to make room for it. This leads to a constant
need for retransmits, and subsequent receiver stalls. The fix I've come up
with is to deliver the frame without reneging if we have a full receive
buffer and the receiving sockets sk_receive_queue is empty(indicating that
the receive buffer is being blocked by a missing tsn).
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>

Right now, every time we increase our rwnd by more then MTU bytes, we
trigger a SACK.  When processing large messages, this will generate a
SACK for almost every other SCTP fragment. However since we are freeing
the entire message at the same time, we might as well collapse the SACK
generation to 1.
Signed-off-by: NTsutomu Fujii <t-fujii@nb.jp.nec.com>
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>

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

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>

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>

When using ASSOCINFO socket option, we need to limit the number of
maximum association retransmissions to be no greater than the sum
of all the path retransmissions. This is specified in Section 7.1.2
of the SCTP socket API draft.
However, we only do this if the association has multiple paths. If
there is only one path, the protocol stack will use the
assoc_max_retrans setting when trying to retransmit packets.
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>

Enable SO_LINGER functionality for 1-N style sockets. The socket API
draft will be clarfied to allow for this functionality. The linger
settings will apply to all associations on a given socket.
Signed-off-by: NVladislav Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>

If SCTP receives a badly formatted HB-ACK chunk, it is possible
that we may access invalid memory and potentially have a buffer
overflow.  We should really make sure that the chunk format is
what we expect, before attempting to touch the data.
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>

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>