SCTP will delay the last part of a large write due to NAGLE, if that
part is smaller then MTU.  Since we are doing large writes, we might
as well send the last portion now instead of waiting untill the next
large write happens.  The small portion will be sent as is regardless,
so it's better to not delay it.

This is a result of much discussions with Wei Yongjun <yjwei@cn.fujitsu.com>
and Doug Graham <dgraham@nortel.com>.  Many thanks go out to them.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

The decision to delay due to Nagle should be based on the path mtu
and future packet size.  We currently incorrectly base it on
'frag_point' which is the SCTP DATA segment size, and also we do
not count DATA chunk header overhead in the computation.  This
actuall allows situations where a user can set low 'frag_point',
and then send small messages without delay.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

We currently set a_rwnd to 0 when faking a SACK from SHUTDOWN.
This results in an hung association if the remote only uses
SHUTDOWNs (which it's allowed to do) to acknowlege DATA when
closing.  The reason for that is that we simply honor the a_rwnd
from the sack, but since we faked it to be 0, we enter 0-window
probing.  The fix is to use the peers old rwnd and add our flight
size to it.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

SCTP has a problem that when small chunks are used, it is possible
to exhaust the receiver buffer without fully closing receive window.
This happens due to all overhead that we have account for with small
messages.  To fix this, when receive buffer is exceeded, we'll drop
the window to 0 and save the 'drop' portion.  When application starts
reading data and freeing up recevie buffer space, we'll wait until
we've reached the 'drop' window and then add back this 'drop' one
mtu at a time.  This worked well in testing and under stress produced
rather even recovery.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

If T3 timer expires, we are retransmitting data due to timeout any
any fast recovery is null and void.  We can clear the fast recovery
flag.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

SCTP RFC 4960 states that unacknowledged HEARTBEATS count as
errors agains a given transport or endpoint.  As such, we
should increment the error counts for only for unacknowledged
HB, otherwise we detect failure too soon.  This goes for both
the overall error count and the path error count.

Now, there is a difference in how the detection is done
between the two.  The path error detection is done after
the increment, so to detect it properly, we actually need
to exceed the path threshold.  The overall error detection
is done _BEFORE_ the increment.  Thus to detect the failure,
it's enough for the error count to match the threshold.
This is why all the state functions use '>=' to detect failure,
while path detection uses '>'.

Thanks goes to Chunbo Luo <chunbo.luo@windriver.com> who first
proposed patches to fix this issue and made me re-read the spec
and the code to figure out how this cruft really works.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

create_proc_entry() is deprecated (not formally, though).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

The receiver of the HEARTBEAT should respond with a HEARTBEAT ACK
that contains the Heartbeat Information field copied from the
received HEARTBEAT chunk. So the received HEARTBEAT-ACK chunk
must have a length of:
  sizeof(sctp_chunkhdr_t) + sizeof(sctp_sender_hb_info_t)

A badly formatted HB-ACK chunk, it is possible that we may access
invalid memory.  We should really make sure that the chunk format
is what we expect, before attempting to touch the data.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

If Cumulative TSN Ack field of SHUTDOWN chunk is less than the
Cumulative TSN Ack Point then drop the SHUTDOWN chunk.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

Currenlty, sctp breaks up user messages into fragments and
sends each fragment to the lower layer by itself.  This means
that for each fragment we go all the way down the stack
and back up.  This also discourages bundling of multiple
fragments when they can fit into a sigle packet (ex: due
to user setting a low fragmentation threashold).

We introduce a new command SCTP_CMD_SND_MSG and hand the
whole message down state machine.  The state machine and
the side-effect parser will cork the queue, add all chunks
from the message to the queue, and then un-cork the queue
thus causing the chunks to get transmitted.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

If the association has a SACK timer pending and now DATA queued
to be send, we'll try to bundle the SACK with the next application send.
As such, try encourage bundling by accounting for SACK in the size
of the first chunk fragment.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

We are now trying to bundle SACKs when we have outbound
DATA to send.  However, there are situations where this
outbound DATA will not be sent (due to congestion or 
available window).  In such cases it's ok to wait for the
timer to expire.  This patch refactors the sending code
so that betfore attempting to bundle the SACK we check
to see if the DATA will actually be transmitted.

Based on eirlier works for Doug Graham <dgraham@nortel.com> and
Wei Youngjun <yjwei@cn.fujitsu.com>.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

Since an application may specify the maximum SCTP fragment size
that all data should be fragmented to, we need to fix how
we do segmentation.   Right now, if a user specifies a small
fragment size, the segment size can go negative in the presence
of AUTH or COOKIE_ECHO bundling.

What we need to do is track the largest possbile DATA chunk that
can fit into the mtu.  Then if the fragment size specified is
bigger then this maximum length, we'll shrink it down.  Otherwise,
we just use the smaller segment size without changing it further.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

If a socket has a lot of association that are in the process of
of being closed/aborted, it is possible for a remote to establish
new associations during the time period that the old ones are shutting
down.  If this was a result of a close() call, there will be no socket
and will cause a memory leak.  We'll prevent this by setting the
socket state to CLOSING and disallow new associations when in this state.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

This patch corrects the conditions under which a SACK will be piggybacked
on a DATA packet.  The previous condition was incorrect due to a
misinterpretation of RFC 4960 and/or RFC 2960.  Specifically, the
following paragraph from section 6.2 had not been implemented correctly:

   Before an endpoint transmits a DATA chunk, if any received DATA
   chunks have not been acknowledged (e.g., due to delayed ack), the
   sender should create a SACK and bundle it with the outbound DATA
   chunk, as long as the size of the final SCTP packet does not exceed
   the current MTU.  See Section 6.2.

When about to send a DATA chunk, the code now checks to see if the SACK
timer is running.  If it is, we know we have a SACK to send to the
peer, so we append the SACK (assuming available space in the packet)
and turn off the timer.  For a simple request-response scenario, this
will result in the SACK being bundled with the response, meaning the
the SACK is received quickly by the client, and also meaning that no
separate SACK packet needs to be sent by the server to acknowledge the
request.  Prior to this patch, a separate SACK packet would have been
sent by the server SCTP only after its delayed-ACK timer had expired
(usually 200ms).  This is wasteful of bandwidth, and can also have a
major negative impact on performance due the interaction of delayed ACKs
with the Nagle algorithm.
Signed-off-by: Doug Graham <dgraham@nortel.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

This patch removes an unused union definition (sctp_cmsg_data_t)
from include/net/sctp/user.h.
Signed-off-by: Rami Rosen <rosenrami@gmail.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

When the sctp transport is marked down, we can release the
cached route and force a new lookup when attempting to use
this transport for anything.  This way, if a better route
or source address is available, we'll try to use it.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

Update the route and saddr entries for the non-active transports as some
of the added addresses can be used as better source addresses, or may
be there is a better route.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

This patch fix to check the unrecognized ASCONF parameter before
access it.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

The return value of sctp_process_asconf_ack() may be
overwritten while process parameters with no error.
This patch fixed the problem.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

Signed-off-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds support for legacy SJA1000 CAN controllers on the ISA
or PC-104 bus. The I/O port or memory address and the IRQ number must
be specified via module parameters:

  insmod sja1000_isa.ko port=0x310,0x380 irq=7,11

for ISA devices using I/O ports or:

  insmod sja1000_isa.ko mem=0xd1000,0xd1000 irq=7,11

for memory mapped ISA devices.

Indirect access via address and data port is supported as well:

  insmod sja1000_isa.ko port=0x310,0x380 indirect=1 irq=7,11

Here is a full list of the supported module parameters:

  port:I/O port number (array of ulong)
  mem:I/O memory address (array of ulong)
  indirect:Indirect access via address and data port (array of byte)
  irq:IRQ number (array of int)
  clk:External oscillator clock frequency (default=16000000 [16 MHz])
      (array of int)
  cdr:Clock divider register (default=0x48 [CDR_CBP | CDR_CLK_OFF])
      (array of byte)
  ocr:Output clock register (default=0x18 [OCR_TX0_PUSHPULL])
      (array of byte)

Note: for clk, cdr, ocr, the first argument re-defines the default
for all other devices, e.g.:

 insmod sja1000_isa.ko mem=0xd1000,0xd1000 irq=7,11 clk=24000000

is equivalent to

 insmod sja1000_isa.ko mem=0xd1000,0xd1000 irq=7,11 \
                       clk=24000000,24000000
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Tested-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

The member "tx_bytes" of "struct net_device_stats" should be
incremented when the interrupt is done and an "arbitration
lost error" is a TX error and the statistics should be updated
accordingly.
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds the function can_free_echo_skb to the CAN
device interface to allow upcoming drivers to release echo
skb's in case of error.
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Noticed by Stephen Rothwell:

	Today's linux-next build (x86_64 allmodconfig gcc-4.4.0)
	produced this warning:

	drivers/net/wan/dscc4.c: In function 'dscc4_rx_skb':
	drivers/net/wan/dscc4.c:670: warning: suggest parentheses around comparison in operand of '|'

	which actually points out a bug, I think.  It is doing
		(x & (y | z)) != y | z
	when it probably means
		(x & (y | z)) != (y | z)

	Introduced by commit 5de3fcab
	("WAN: bit and/or confusion").
Signed-off-by: David S. Miller <davem@davemloft.net>

Here is a patch which fixes an issue observed when using TCP over IPv6
and AH from IPsec.

When a connection gets closed the 4-way method and the last ACK from
the server gets dropped, the subsequent FINs from the client do not
get ACKed because tcp_v6_send_response does not set the transport
header pointer. This causes ah6_output to try to allocate a lot of
memory, which typically fails, so the ACKs never make it out of the
stack.

I have reproduced the problem on kernel 2.6.7, but after looking at
the latest kernel it seems the problem is still there.
Signed-off-by: Cosmin Ratiu <cratiu@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

To unclutter probe() a little bit, put all device initialization code
in one spot and device deinit code in another spot.  Also remove unused
rq->buf_index variable/func.
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Nic firmware can return zero for port MTU, so check for non-zero value
before checking for change in port MTU.
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Deprecate some old APIa; change arguments to stats dump all API; add new
interrupt assert API
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bug fix: enable VLAN filtering
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Provision for multiple Rx/Tx queues.  Max of 8 WQs and 8 RQs.  Max for
completion queue is 8+8=16 and max for interrupt resources is 8+8+2.

Add driver/firmware interface for setting up RSS secret key and indirection
table.
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bug fix: included MAC drops in rx_dropped netstat.  Also track Rx trunctations
stat at the MAC
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some driver -> nic firmware calls weren't guarded with a spinlock, exposing
the call i/f to a race between two threads
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use netdev_alloc_skb rather than dev_alloc_skb
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

enic WQ desc supports a maximum 16K buf size, so split any send fragments
larger than 16K into several descs.
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A0 revision ASIC has an erratum on the RQ desc cache on chip where the
cache can become corrupted causing pkt buf writes to wrong locations.  The s/w
workaround is to post a dummy RQ desc in the ring every 32 descs, causing a
flush of the cache.  A0 parts are not production, but there are enough of
these parts in the wild in test setups to warrant including workaround.  A1
revision ASIC parts fix erratum.
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Nic firmware can place resources (queues, intrs, etc) on multiple BARs, so
allow driver to discover/map resources beyond BAR0.
Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Its hard to tell if vlans are dropping frames, since
every frame given to vlan_???_start_xmit() functions
is accounted as fully transmitted by lower device.

We can test dev_queue_xmit() return values to
properly account for dropped frames.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan devices are currently not multi-queue capable.

We can do that defining rtnl_link_ops method,
get_tx_queues(), called from rtnl_create_link()

This new method gets num_tx_queues/real_num_tx_queues
from lower device.

macvlan_get_tx_queues() is a copy of vlan_get_tx_queues().

Because macvlan_start_xmit() has to update netdev_queue
stats only (and not dev->stats), I chose to change
tx_errors/tx_aborted_errors accounting to tx_dropped,
since netdev_queue structure doesnt define tx_errors /
tx_aborted_errors.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A few drivers still access the arguments to MDIO ioctls as an array of
u16.  Convert them to use struct mii_ioctl_data.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>