The RTNL is required to check for IR-relaxation conditions that allow
more channels to beacon. Export an RTNL locked version of reg_can_beacon
and use it where possible in AP/STA interface type flows, where
IR-relaxation may be applicable.

Fixes: 06f207fc5418 ("cfg80211: change GO_CONCURRENT to IR_CONCURRENT for STA")
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Although mesh_rx_plink_frame() already checks that frames have enough
bytes for the action code plus another two bytes for capability/reason
code, it doesn't take into account that confirm frames also have an
additional two-byte aid.  As a result, a corrupt frame could cause a
subsequent subtraction to wrap around to ill effect.  Add another
check for this case.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

According to 802.11-2012 8.5.16.3.2 AID comes directly after the
capability bytes in mesh peering confirm frames.  The existing
code, however, was adding a 2 byte offset to this location,
resulting in garbage data going out over the air.  Remove the
offset to fix it.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

If the hardware is unregistered while interfaces are up, mac80211 will
unregister all interfaces, which in turns causes mac80211 to be called
again to remove them all from the driver and eventually shut down the
hardware.

During this shutdown, however, it's currently already unsafe to iterate
the list of interfaces atomically, as the list is manipulated in an
unsafe manner. This puts an undue burden on the driver - it must stop
all its activities before calling ieee80211_unregister_hw(), while in
the normal stop path it can do all cleanup in the stop method. If, for
example, it's using the iteration during RX for some reason, it would
have to stop RX before unregistering to avoid crashes.

Fix this problem by closing all interfaces before unregistering them.
This will cause the driver stop to have completed before we manipulate
the interface list, and after the driver is stopped *and* has called
ieee80211_unregister_hw() it really musn't be iterating any more as
the memory will be freed as well.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

If for any reason we're in the middle of PS-polling or awake after
TX due to dynamic powersave while going to suspend, go back to save
power. This might cause a response frame to get lost, but since we
can't really wait for it while going to suspend that's still better
than not enabling powersave which would cause higher power usage
during (and possibly even after) suspend.

Note that this really only affects the very few drivers that use
the powersave implementation in mac80211.

Signed-off-by: Chaitanya T K <chaitanya.mgit@gmail.com>
[rewrite misleading commit log]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When acting as AP and a PS-Poll frame is received
associated station is marked as one in a Service
Period. This state is kept until Tx status for
released frame is reported. While a station is in
Service Period PS-Poll frames are ignored.

However if PS-Poll was received during A-MPDU
teardown it was possible to have the to-be
released frame re-queued back to pending queue.
In such case the frame was stripped of 2 important
flags:

 (a) IEEE80211_TX_CTL_NO_PS_BUFFER
 (b) IEEE80211_TX_STATUS_EOSP

Stripping of (a) led to the frame that was to be
released to be queued back to ps_tx_buf queue. If
station remained to use only PS-Poll frames the
re-queued frame (and new ones) was never actually
transmitted because mac80211 would ignore
subsequent PS-Poll frames due to station being in
Service Period. There was nothing left to clear
the Service Period bit (no xmit -> no tx status ->
no SP end), i.e. the AP would have the station
stuck in Service Period. Beacon TIM would
repeatedly prompt station to poll for frames but
it would get none.

Once (a) is not stripped (b) becomes important
because it's the main condition to clear the
Service Period bit of the station when Tx status
for the released frame is reported back.

This problem was observed with ath9k acting as P2P
GO in some testing scenarios but isn't limited to
it. AP operation with mac80211 based Tx A-MPDU
control combined with clients using PS-Poll frames
is subject to this race.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

If we don't do this, and we then fail to recreate the debugfs
directory during a mode change, then we will fail later trying
to add stations to this now bogus directory:

BUG: unable to handle kernel NULL pointer dereference at 0000006c
IP: [<c0a92202>] mutex_lock+0x12/0x30
Call Trace:
[<c0678ab4>] start_creating+0x44/0xc0
[<c0679203>] debugfs_create_dir+0x13/0xf0
[<f8a938ae>] ieee80211_sta_debugfs_add+0x6e/0x490 [mac80211]

Cc: stable@kernel.org
Signed-off-by: Tom Hughes <tom@compton.nu>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Pull module updates from Rusty Russell:
 "Main excitement here is Peter Zijlstra's lockless rbtree optimization
  to speed module address lookup.  He found some abusers of the module
  lock doing that too.

  A little bit of parameter work here too; including Dan Streetman's
  breaking up the big param mutex so writing a parameter can load
  another module (yeah, really).  Unfortunately that broke the usual
  suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were
  appended too"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits)
  modules: only use mod->param_lock if CONFIG_MODULES
  param: fix module param locks when !CONFIG_SYSFS.
  rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE()
  module: add per-module param_lock
  module: make perm const
  params: suppress unused variable error, warn once just in case code changes.
  modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'.
  kernel/module.c: avoid ifdefs for sig_enforce declaration
  kernel/workqueue.c: remove ifdefs over wq_power_efficient
  kernel/params.c: export param_ops_bool_enable_only
  kernel/params.c: generalize bool_enable_only
  kernel/module.c: use generic module param operaters for sig_enforce
  kernel/params: constify struct kernel_param_ops uses
  sysfs: tightened sysfs permission checks
  module: Rework module_addr_{min,max}
  module: Use __module_address() for module_address_lookup()
  module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING
  module: Optimize __module_address() using a latched RB-tree
  rbtree: Implement generic latch_tree
  seqlock: Introduce raw_read_seqcount_latch()
  ...

Pull networking updates from David Miller:

 1) Add TX fast path in mac80211, from Johannes Berg.

 2) Add TSO/GRO support to ibmveth, from Thomas Falcon

 3) Move away from cached routes in ipv6, just like ipv4, from Martin
    KaFai Lau.

 4) Lots of new rhashtable tests, from Thomas Graf.

 5) Run ingress qdisc lockless, from Alexei Starovoitov.

 6) Allow servers to fetch TCP packet headers for SYN packets of new
    connections, for fingerprinting.  From Eric Dumazet.

 7) Add mode parameter to pktgen, for testing receive.  From Alexei
    Starovoitov.

 8) Cache access optimizations via simplifications of build_skb(), from
    Alexander Duyck.

 9) Move page frag allocator under mm/, also from Alexander.

10) Add xmit_more support to hv_netvsc, from KY Srinivasan.

11) Add a counter guard in case we try to perform endless reclassify
    loops in the packet scheduler.

12) Extern flow dissector to be programmable and use it in new "Flower"
    classifier.  From Jiri Pirko.

13) AF_PACKET fanout rollover fixes, performance improvements, and new
    statistics.  From Willem de Bruijn.

14) Add netdev driver for GENEVE tunnels, from John W Linville.

15) Add ingress netfilter hooks and filtering, from Pablo Neira Ayuso.

16) Fix handling of epoll edge triggers in TCP, from Eric Dumazet.

17) Add an ECN retry fallback for the initial TCP handshake, from Daniel
    Borkmann.

18) Add tail call support to BPF, from Alexei Starovoitov.

19) Add several pktgen helper scripts, from Jesper Dangaard Brouer.

20) Add zerocopy support to AF_UNIX, from Hannes Frederic Sowa.

21) Favor even port numbers for allocation to connect() requests, and
    odd port numbers for bind(0), in an effort to help avoid
    ip_local_port_range exhaustion.  From Eric Dumazet.

22) Add Cavium ThunderX driver, from Sunil Goutham.

23) Allow bpf programs to access skb_iif and dev->ifindex SKB metadata,
    from Alexei Starovoitov.

24) Add support for T6 chips in cxgb4vf driver, from Hariprasad Shenai.

25) Double TCP Small Queues default to 256K to accomodate situations
    like the XEN driver and wireless aggregation.  From Wei Liu.

26) Add more entropy inputs to flow dissector, from Tom Herbert.

27) Add CDG congestion control algorithm to TCP, from Kenneth Klette
    Jonassen.

28) Convert ipset over to RCU locking, from Jozsef Kadlecsik.

29) Track and act upon link status of ipv4 route nexthops, from Andy
    Gospodarek.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1670 commits)
  bridge: vlan: flush the dynamically learned entries on port vlan delete
  bridge: multicast: add a comment to br_port_state_selection about blocking state
  net: inet_diag: export IPV6_V6ONLY sockopt
  stmmac: troubleshoot unexpected bits in des0 & des1
  net: ipv4 sysctl option to ignore routes when nexthop link is down
  net: track link-status of ipv4 nexthops
  net: switchdev: ignore unsupported bridge flags
  net: Cavium: Fix MAC address setting in shutdown state
  drivers: net: xgene: fix for ACPI support without ACPI
  ip: report the original address of ICMP messages
  net/mlx5e: Prefetch skb data on RX
  net/mlx5e: Pop cq outside mlx5e_get_cqe
  net/mlx5e: Remove mlx5e_cq.sqrq back-pointer
  net/mlx5e: Remove extra spaces
  net/mlx5e: Avoid TX CQE generation if more xmit packets expected
  net/mlx5e: Avoid redundant dev_kfree_skb() upon NOP completion
  net/mlx5e: Remove re-assignment of wq type in mlx5e_enable_rq()
  net/mlx5e: Use skb_shinfo(skb)->gso_segs rather than counting them
  net/mlx5e: Static mapping of netdev priv resources to/from netdev TX queues
  net/mlx4_en: Use HW counters for rx/tx bytes/packets in PF device
  ...

Conflicts:
	drivers/net/ethernet/mellanox/mlx4/main.c
	net/packet/af_packet.c

Both conflicts were cases of simple overlapping changes.

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