Commit Graph

4341 Commits

Author SHA1 Message Date
Arun Sharma
60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
Linus Torvalds
d3ec4844d4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  fs: Merge split strings
  treewide: fix potentially dangerous trailing ';' in #defined values/expressions
  uwb: Fix misspelling of neighbourhood in comment
  net, netfilter: Remove redundant goto in ebt_ulog_packet
  trivial: don't touch files that are removed in the staging tree
  lib/vsprintf: replace link to Draft by final RFC number
  doc: Kconfig: `to be' -> `be'
  doc: Kconfig: Typo: square -> squared
  doc: Konfig: Documentation/power/{pm => apm-acpi}.txt
  drivers/net: static should be at beginning of declaration
  drivers/media: static should be at beginning of declaration
  drivers/i2c: static should be at beginning of declaration
  XTENSA: static should be at beginning of declaration
  SH: static should be at beginning of declaration
  MIPS: static should be at beginning of declaration
  ARM: static should be at beginning of declaration
  rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check
  Update my e-mail address
  PCIe ASPM: forcedly -> forcibly
  gma500: push through device driver tree
  ...

Fix up trivial conflicts:
 - arch/arm/mach-ep93xx/dma-m2p.c (deleted)
 - drivers/gpio/gpio-ep93xx.c (renamed and context nearby)
 - drivers/net/r8169.c (just context changes)
2011-07-25 13:56:39 -07:00
Linus Torvalds
ee05eff6f7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (145 commits)
  bnx2x: use pci_pcie_cap()
  bnx2x: fix bnx2x_stop_on_error flow in bnx2x_sp_rtnl_task
  bnx2x: enable internal target-read for 57712 and up only
  bnx2x: count statistic ramrods on EQ to prevent MC assert
  bnx2x: fix loopback for non 10G link
  bnx2x: dcb - send all unmapped priorities to same COS as L2
  iwlwifi: Fix build with CONFIG_PM disabled.
  gre: fix improper error handling
  ipv4: use RT_TOS after some rt_tos conversions
  via-velocity: remove duplicated #include
  qlge: remove duplicated #include
  igb: remove duplicated #include
  can: c_can: remove duplicated #include
  bnad: remove duplicated #include
  net: allow netif_carrier to be called safely from IRQ
  bna: Header File Consolidation
  bna: HW Error Counter Fix
  bna: Add HW Semaphore Unlock Logic
  bna: IOC Event Name Change
  bna: Mboxq Flush When IOC Disabled
  ...
2011-07-24 20:55:48 -07:00
Aneesh Kumar K.V
48e370ff93 fs/9p: add 9P2000.L unlinkat operation
unlinkat - Remove a directory entry

size[4] Tunlinkat tag[2] dirfid[4] name[s] flag[4]
size[4] Runlinkat tag[2]

older Tremove have the below request format

size[4] Tremove tag[2] fid[4]

The remove message is used to remove a directory entry either file or directory
The remove opreation is actually a directory opertation and should ideally have
dirfid, if not we cannot represent the fid on server with anything other than
name. We will have to derive the directory name from fid in the Tremove request.

NOTE: The operation doesn't clunk the unlink fid.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23 09:32:52 -05:00
Aneesh Kumar K.V
9e8fb38e7d fs/9p: add 9P2000.L renameat operation
renameat - change name of file or directory

size[4] Trenameat tag[2] olddirfid[4] oldname[s] newdirfid[4] newname[s]
size[4] Rrenameat tag[2]

older Trename have the below request format

size[4] Trename tag[2] fid[4] newdirfid[4] name[s]

The rename message is used to change the name of a file, possibly moving it
to a new directory. The rename opreation is actually a directory opertation
and should ideally have olddirfid, if not we cannot represent the fid on server
with anything other than name. We will have to derive the old directory name
from fid in the Trename request.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23 09:32:51 -05:00
Prem Karat
4d63055fa9 fs/9p: Clean-up get_protocol_version() to use strcmp
Signed-off-by: Prem Karat <prem.karat@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23 09:32:49 -05:00
Aneesh Kumar K.V
52c14ab3b5 net/9p: Remove structure not used in the code
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23 09:32:48 -05:00
Eric Van Hensbergen
e660a828f0 9p: clean up packet dump code
Switch to generic kernel hexdump library and cleanup macros to
be more consistent with the way we do normal debug prints.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23 09:32:47 -05:00
John W. Linville
41bf37117b Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem 2011-07-22 17:51:16 -04:00
Eric Dumazet
87c48fa3b4 ipv6: make fragment identifications less predictable
IPv6 fragment identification generation is way beyond what we use for
IPv4 : It uses a single generator. Its not scalable and allows DOS
attacks.

Now inetpeer is IPv6 aware, we can use it to provide a more secure and
scalable frag ident generator (per destination, instead of system wide)

This patch :
1) defines a new secure_ipv6_id() helper
2) extends inet_getid() to provide 32bit results
3) extends ipv6_select_ident() with a new dest parameter

Reported-by: Fernando Gont <fernando@gont.com.ar>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-21 21:25:58 -07:00
Johannes Berg
b2abb6e2bc mac80211: sync driver before TX
In P2P client mode, the GO (AP) to connect to might
have periods of time where it is not available due
to powersave. To allow the driver to sync with it
and send frames to the GO only when it is available
add a new callback tx_sync (and the corresponding
finish_tx_sync). These callbacks can sleep unlike
the actual TX.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-20 15:04:35 -04:00
Johannes Berg
34850ab25d cfg80211: allow userspace to control supported rates in scan
Some P2P scans are not allowed to advertise
11b rates, but that is a rather special case
so instead of having that, allow userspace
to request the rate sets (per band) that are
advertised in scan probe request frames.

Since it's needed in two places now, factor
out some common code parsing a rate array.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-19 16:49:58 -04:00
David S. Miller
d3aaeb38c4 net: Add ->neigh_lookup() operation to dst_ops
In the future dst entries will be neigh-less.  In that environment we
need to have an easy transition point for current users of
dst->neighbour outside of the packet output fast path.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-18 00:40:17 -07:00
David S. Miller
69cce1d140 net: Abstract dst->neighbour accesses behind helpers.
dst_{get,set}_neighbour()

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-17 23:11:35 -07:00
David S. Miller
9cbb7ecbcf ipv6: Get rid of rt6i_nexthop macro.
It just makes it harder to see 1) what the code is doing
and 2) grep for all users of dst{->,.}neighbour

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-17 23:11:35 -07:00
David S. Miller
8f40b161de neigh: Pass neighbour entry to output ops.
This will get us closer to being able to do "neigh stuff"
completely independent of the underlying dst_entry for
protocols (ipv4/ipv6) that wish to do so.

We will also be able to make dst entries neigh-less.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-17 23:11:17 -07:00
David S. Miller
542d4d685f neigh: Kill ndisc_ops->queue_xmit
It is always dev_queue_xmit().

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-16 18:30:59 -07:00
David S. Miller
b23b5455b6 neigh: Kill hh_cache->hh_output
It's just taking on one of two possible values, either
neigh_ops->output or dev_queue_xmit().  And this is purely depending
upon whether nud_state has NUD_CONNECTED set or not.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-16 17:45:02 -07:00
David S. Miller
47ec132a40 neigh: Kill neigh_ops->hh_output
It's always dev_queue_xmit().

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-16 17:39:57 -07:00
David S. Miller
05e3aa0949 net: Create and use new helper, neigh_output().
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-16 17:26:00 -07:00
Johannes Berg
f850e00fcd mac80211: let key iteration get keys in install order
ieee80211_iter_keys() currently returns keys in
the backward order they were installed in, which
is a bit confusing. Add them to the tail of the
key list to make sure iterations go in the same
order that keys were originally installed in.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-15 13:38:33 -04:00
Johannes Berg
8bca5d8153 mac80211: allow driver access to TKIP RX P1K
When the driver wants to pre-program the TKIP
RX phase 1 key, it needs to be able to obtain
it for the peer's TA. Add API to allow it to
generate it.

The generation uses a dummy on-stack context
since it doesn't know the RX queue.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-15 13:38:32 -04:00
Luciano Coelho
5a865bad44 nl80211/cfg80211: add max_sched_scan_ie_len in the hw description
Some chips may support different lengths of user-supplied IEs with a
single scheduled scan command than with a single normal scan command.

To support this, this patch creates a separate hardware description
element that describes the maximum size of user-supplied information
element data supported in scheduled scans.

Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-15 13:38:30 -04:00
Luciano Coelho
93b6aa693a nl80211/cfg80211: add max_sched_scan_ssids in the hw description
Some chips can scan more SSIDs with a single scheduled scan command
than with a single normal scan command (eg. wl12xx chips).

To support this, this patch creates a separate hardware description
element that describes the amount of SSIDs supported in scheduled
scans.

Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-15 13:38:29 -04:00
Johannes Berg
77dbbb1389 nl80211: advertise GTK rekey support, new triggers
Since we now have the necessary API in place to support
GTK rekeying, applications will need to know whether it
is supported by a device. Add a pseudo-trigger that is
used only to advertise that capability. Also, add some
new triggers that match what iwlagn devices can do.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-15 13:38:28 -04:00
John W. Linville
95a943c162 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem
Conflicts:
	net/bluetooth/l2cap_core.c
2011-07-15 10:05:24 -04:00
David S. Miller
6a7ebdf2fd Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/bluetooth/l2cap_core.c
2011-07-14 07:56:40 -07:00
David S. Miller
f6b72b6217 net: Embed hh_cache inside of struct neighbour.
Now that there is a one-to-one correspondance between neighbour
and hh_cache entries, we no longer need:

1) dynamic allocation
2) attachment to dst->hh
3) refcounting

Initialization of the hh_cache entry is indicated by hh_len
being non-zero, and such initialization is always done with
the neighbour's lock held as a writer.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-14 07:53:20 -07:00
Johannes Berg
95acac61ba mac80211: allow driver to disconnect after resume
In WoWLAN, devices may use crypto keys for TX/RX
and could also implement GTK rekeying. If the
driver isn't able to retrieve replay counters and
similar information from the device upon resume,
or if the device isn't responsive due to platform
issues, it isn't safe to keep the connection up
as GTK rekey messages from during the sleep time
could be replayed against it.

The only protection against that is disconnecting
from the AP. Modifying mac80211 to do that while
it is resuming would be very complex and invasive
in the case that the driver requires a reconfig,
so do it after it has resumed completely. In that
case, however, packets might be replayed since it
can then only happen after TX/RX are up again, so
mark keys for interfaces that need to disconnect
as "tainted" and drop all packets that are sent
or received with those keys.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-13 14:49:43 -04:00
David Miller
3769cffb1c ipv4: Inline neigh binding.
Get rid of all of the useless and costly indirection
by doing the neigh hash table lookup directly inside
of the neighbour binding.

Rename from arp_bind_neighbour to rt_bind_neighbour.

Use new helpers {__,}ipv4_neigh_lookup()

In rt_bind_neighbour() get rid of useless tests which
are never true in the context this function is called,
namely dev is never NULL and the dst->neighbour is
always NULL.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-13 01:12:28 -07:00
Johannes Berg
af71ff8504 cfg80211: fix docbook
Looks like I forgot to document the "gfp" parameter
to cfg80211_gtk_rekey_notify, add it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-11 15:02:18 -04:00
Meenakshi Venkataraman
615f7b9bb1 mac80211: add driver RSSI threshold events
mac80211 maintains a running average of the RSSI when a STA
is associated to an AP. Report threshold events to any driver
that has registered callbacks for getting RSSI measurements.

Implement callbacks in mac80211 so that driver can set thresholds.
Add callbacks in mac80211 which is invoked when an RSSI threshold
event occurs.

mac80211: add tracing to rssi_reports api and remove extraneous fn argument
mac80211: scale up rssi thresholds from driver by 16 before storing

Signed-off-by: Meenakshi Venkataraman <meenakshi.venkataraman@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-11 15:02:06 -04:00
John W. Linville
4b42c542af Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/padovan/bluetooth-next-2.6
Conflicts:
	net/bluetooth/l2cap_core.c
2011-07-11 14:58:22 -04:00
Jiri Kosina
b7e9c223be Merge branch 'master' into for-next
Sync with Linus' tree to be able to apply pending patches that
are based on newer code already present upstream.
2011-07-11 14:15:55 +02:00
David S. Miller
f610b74b14 ipv4: Use universal hash for ARP.
We need to make sure the multiplier is odd.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-11 01:37:28 -07:00
David S. Miller
cd0893369c neigh: Store hash shift instead of mask.
And mask the hash function result by simply shifting
down the "->hash_shift" most significant bits.

Currently which bits we use is arbitrary since jhash
produces entropy evenly across the whole hash function
result.

But soon we'll be using universal hashing functions,
and in those cases more entropy exists in the higher
bits than the lower bits, because they use multiplies.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-11 01:28:12 -07:00
Ilia Kolomisnky
e2fd318e3a Bluetooth: Fixes l2cap "command reject" reply according to spec
There can 3 reasons for the "command reject" reply produced
by the stack. Each such reply should be accompanied by the
relevand data ( as defined in spec. ). Currently there is one
instance of "command reject" reply with reason "invalid cid"
wich is fixed. Also, added clean-up definitions related to the
"command reject" replies.

Signed-off-by: Ilia Kolomisnky <iliak@ti.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-07-11 01:43:25 -03:00
Vinicius Costa Gomes
8f36011924 Bluetooth: Add support for returning the encryption key size
This will be useful when userspace wants to restrict some kinds of
operations based on the length of the key size used to encrypt the
link.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-07-08 18:39:31 -03:00
Vinicius Costa Gomes
726b4ffcaa Bluetooth: Add support for storing the key size
In some cases it will be useful having the key size used for
encrypting the link. For example, some profiles may restrict
some operations depending on the key length.

The key size is stored in the key that is passed to userspace
using the pin_length field in the key structure.

For now this field is only valid for LE controllers. 3.0+HS
controllers define the Read Encryption Key Size command, this
field is intended for storing the value returned by that
command.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-07-08 18:39:19 -03:00
Vinicius Costa Gomes
0eb08e3398 Bluetooth: Remove unused field in hci_conn
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-07-08 17:37:22 -03:00
Vinicius Costa Gomes
75d262c2ad Bluetooth: Add functions to manipulate the link key list for SMP
As the LTK (the new type of key being handled now) has more data
associated with it, we need to store this extra data and retrieve
the keys based on that data.

Methods for searching for a key and for adding a new LTK are
introduced here.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-07-08 17:36:31 -03:00
Vinicius Costa Gomes
34918cd71b Bluetooth: Add new structures for supporting SM key distribution
We need these changes because SMP keys may have more information
associated with them, for example, in the LTK case, it has an
encrypted diversifier (ediv) and a random number (rand).

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-07-08 17:36:25 -03:00
Michal Hocko
d8bf4ca9ca rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check
Since ca5ecddf (rcu: define __rcu address space modifier for sparse)
rcu_dereference_check use rcu_read_lock_held as a part of condition
automatically so callers do not have to do that as well.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-07-08 22:21:58 +02:00
Vinicius Costa Gomes
7034b911af Bluetooth: Add support for SMP phase 3 (key distribution)
This adds support for generating and distributing all the keys
specified in the third phase of SMP.

This will make possible to re-establish secure connections, resolve
private addresses and sign commands.

For now, the values generated are random.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-07-08 17:07:43 -03:00
Thomas Graf
cd4fcc704f sctp: ABORT if receive, reassmbly, or reodering queue is not empty while closing socket
Trigger user ABORT if application closes a socket which has data
queued on the socket receive queue or chunks waiting on the
reassembly or ordering queue as this would imply data being lost
which defeats the point of a graceful shutdown.

This behavior is already practiced in TCP.

We do not check the input queue because that would mean to parse
all chunks on it to look for unacknowledged data which seems too
much of an effort. Control chunks or duplicated chunks may also
be in the input queue and should not be stopping a graceful
shutdown.

Signed-off-by: Thomas Graf <tgraf@infradead.org>
Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-08 09:53:08 -07:00
Johannes Berg
42d9879550 mac80211: allow driver to generate P1K for IV32
In order to support pre-populating the P1K cache in
iwlwifi hardware for WoWLAN, we need to calculate
the P1K for the current IV32. Allow drivers to get
the P1K for any given IV32 instead of for a given
packet, but keep the packet-based version around as
an inline.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-08 11:42:23 -04:00
Johannes Berg
3ea542d3c2 mac80211: allow drivers to access key sequence counter
In order to implement GTK rekeying, the device needs
to be able to encrypt frames with the right PN/IV and
check the PN/IV in RX frames. To be able to tell it
about all those counters, we need to be able to get
them from mac80211, this adds the required API.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-08 11:42:22 -04:00
Johannes Berg
523b02ea23 mac80211: fix TKIP races, make API easier to use
Our current TKIP code races against itself on TX
since we can process multiple packets at the same
time on different ACs, but they all share the TX
context for TKIP. This can lead to bad IVs etc.

Also, the crypto offload helper code just obtains
the P1K/P2K from the cache, and can update it as
well, but there's no guarantee that packets are
really processed in order.

To fix these issues, first introduce a spinlock
that will protect the IV16/IV32 values in the TX
context. This first step makes sure that we don't
assign the same IV multiple times or get confused
in other ways.

Secondly, change the way the P1K cache works. I
add a field "p1k_iv32" that stores the value of
the IV32 when the P1K was last recomputed, and
if different from the last time, then a new P1K
is recomputed. This can cause the P1K computation
to flip back and forth if packets are processed
out of order. All this also happens under the new
spinlock.

Finally, because there are argument differences,
split up the ieee80211_get_tkip_key() API into
ieee80211_get_tkip_p1k() and ieee80211_get_tkip_p2k()
and give them the correct arguments.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-07-08 11:11:19 -04:00
John W. Linville
204d1641d2 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem 2011-07-08 11:03:36 -04:00
Thomas Graf
f8d9605243 sctp: Enforce retransmission limit during shutdown
When initiating a graceful shutdown while having data chunks
on the retransmission queue with a peer which is in zero
window mode the shutdown is never completed because the
retransmission error count is reset periodically by the
following two rules:

 - Do not timeout association while doing zero window probe.
 - Reset overall error count when a heartbeat request has
   been acknowledged.

The graceful shutdown will wait for all outstanding TSN to
be acknowledged before sending the SHUTDOWN request. This
never happens due to the peer's zero window not acknowledging
the continuously retransmitted data chunks. Although the
error counter is incremented for each failed retransmission,
the receiving of the SACK announcing the zero window clears
the error count again immediately. Also heartbeat requests
continue to be sent periodically. The peer acknowledges these
requests causing the error counter to be reset as well.

This patch changes behaviour to only reset the overall error
counter for the above rules while not in shutdown. After
reaching the maximum number of retransmission attempts, the
T5 shutdown guard timer is scheduled to give the receiver
some additional time to recover. The timer is stopped as soon
as the receiver acknowledges any data.

The issue can be easily reproduced by establishing a sctp
association over the loopback device, constantly queueing
data at the sender while not reading any at the receiver.
Wait for the window to reach zero, then initiate a shutdown
by killing both processes simultaneously. The association
will never be freed and the chunks on the retransmission
queue will be retransmitted indefinitely.

Signed-off-by: Thomas Graf <tgraf@infradead.org>
Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-07 14:08:44 -07:00