Extract the logic from b53_adjust_link() responsible for overriding a
given port's link, speed, duplex and pause settings and make two helper
functions to set the port's configuration and the port's link settings.
We will make use of both, as separate functions while adding PHYLINK
support next.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Update the SRAB driver to manage per-port interrupts. Since we cannot
sleep during b53_io_ops, schedule a workqueue whenever we get a port
specific interrupt. We will later make use of this to call back into
PHYLINK when there is e.g: a link state change.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some switches expose individual interrupt line(s) for port specific
event(s), allow configuring these interrupts at an appropriate time
during port_enable/disable callbacks where all port specific resources
are known to be set-up and ready for use.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds a new qed firmware with fixes and support for new features.

Fixes:
- Fix a rare case of device crash with iWARP, iSCSI or FCoE offload.
- Fix GRE tunneled traffic when iWARP offload is enabled.
- Fix RoCE failure in ib_send_bw when using inline data.
- Fix latency optimization flow for inline WQEs.
- BigBear 100G fix

RDMA:
- Reduce task context size.
- Application page sizes above 2GB support.
- Performance improvements.

ETH:
- Tenant DCB support.
- Replace RSS indirection table update interface.

Misc:
- Debug Tools changes.
Signed-off-by: Denis Bolotin <denis.bolotin@cavium.com>
Signed-off-by: Ariel Elior <ariel.elior@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Christian Brauner says:

====================
rtnetlink: add IFA_TARGET_NETNSID for RTM_GETADDR

This iteration should mainly addresses the suggestion to use
IFA_TARGET_NETNSID as the property name. Additionally, an an alias for
the already existing IFLA_IF_NETNSID property is added.

Note that two additional cleanup patches (8\9 and 9\9) were added to
address concerns raised that passing more than 6 arguments to a function
will cause additional variables to be pushed onto the stack instead of
being placed into registers. The way I addressed this is by introducing
two new struct inet{6}_fill_args that are used to pass common
information down to inet{6}_fill_if*() functions shortening all those
functions to three pointer arguments.
If this is something more people than Kirill find useful they can be
kept if not they can simply be dropped in later iterations of this
series or when merging.

Here is a short overview:
1. Rename from IFA_IF_NETNSID to IFA_TARGET_NETNSID.
2. Add IFLA_TARGET_NETNSID as an alias for IFA_IFLA_NETNSID and switch
   all occurrences over to the new alias.
3. Add inet4_fill_args struct to avoid passing more than 6 arguments in
   inet_fill_if*() functions.
4. Add inet6_fill_args struct to avoid passing more than 6 arguments in
   inet_fill_if*() functions.

The only functional change is the export of rtnl_get_net_ns_capable()
which is needed in case ipv6 is built as a module.

Note, I did not change the property name to IFA_TARGET_NSID as there was
no clear agreement what would be preferred. My personal preference is to
keep the IFA_IF_NETNSID name because it aligns naturally with the
IFLA_IF_NETNSID property for RTM_*LINK requests. Jiri seems to prefer
this name too.
However, if there is agreement that another property name makes more
sense I'm happy to send a v2 that changes this.

To test this patchset I performed 1 million getifaddrs() requests
against a network namespace containing 5 interfaces (lo, eth{0-4}). The
first test used a network namespace aware getifaddrs() implementation I
wrote and the second test used the traditional setns() + getifaddrs()
method. The results show that this patchsets allows userspace to cut
retrieval time in half:
1. netns_getifaddrs():      82 microseconds
2. setns() + getifaddrs(): 162 microseconds

A while back we introduced and enabled IFLA_IF_NETNSID in
RTM_{DEL,GET,NEW}LINK requests (cf. [1], [2], [3], [4], [5]). This has led
to signficant performance increases since it allows userspace to avoid
taking the hit of a setns(netns_fd, CLONE_NEWNET), then getting the
interfaces from the netns associated with the netns_fd. Especially when a
lot of network namespaces are in use, using setns() becomes increasingly
problematic when performance matters.
Usually, RTML_GETLINK requests are followed by RTM_GETADDR requests (cf.
getifaddrs() style functions and friends). But currently, RTM_GETADDR
requests do not support a similar property like IFLA_IF_NETNSID for
RTM_*LINK requests.
This is problematic since userspace can retrieve interfaces from another
network namespace by sending a IFLA_IF_NETNSID property along but
RTM_GETLINK request but is still forced to use the legacy setns() style of
retrieving interfaces in RTM_GETADDR requests.

The goal of this series is to make it possible to perform RTM_GETADDR
requests on different network namespaces. To this end a new IFA_IF_NETNSID
property for RTM_*ADDR requests is introduced. It can be used to send a
network namespace identifier along in RTM_*ADDR requests.  The network
namespace identifier will be used to retrieve the target network namespace
in which the request is supposed to be fulfilled.  This aligns the behavior
of RTM_*ADDR requests with the behavior of RTM_*LINK requests.

- The caller must have assigned a valid network namespace identifier for
  the target network namespace.
- The caller must have CAP_NET_ADMIN in the owning user namespace of the
  target network namespace.

[1]: commit 7973bfd8 ("rtnetlink: remove check for IFLA_IF_NETNSID")
[2]: commit 5bb8ed07 ("rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK")
[3]: commit b61ad68a ("rtnetlink: enable IFLA_IF_NETNSID for RTM_DELLINK")
[4]: commit c310bfcb ("rtnetlink: enable IFLA_IF_NETNSID for RTM_SETLINK")
[5]: commit 7c4f63ba ("rtnetlink: enable IFLA_IF_NETNSID in do_setlink()")
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

inet6_fill_if{addr,mcaddr, acaddr}() already took 6 arguments which
meant the 7th argument would need to be pushed onto the stack on x86.
Add a new struct inet6_fill_args which holds common information passed
to inet6_fill_if{addr,mcaddr, acaddr}() and shortens the functions to
three pointer arguments.
Signed-off-by: Christian Brauner <christian@brauner.io>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet_fill_ifaddr() already took 6 arguments which meant the 7th argument
would need to be pushed onto the stack on x86.
Add a new struct inet_fill_args which holds common information passed
to inet_fill_ifaddr() and shortens the function to three pointer arguments.
Signed-off-by: Christian Brauner <christian@brauner.io>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

IFLA_TARGET_NETNSID is the new alias for IFLA_IF_NETNSID. This commit
replaces all occurrences of IFLA_IF_NETNSID with the new alias to
indicate that this identifier is the preferred one.
Signed-off-by: Christian Brauner <christian@brauner.io>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Cc: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This adds IFLA_TARGET_NETNSID as an alias for IFLA_IF_NETNSID for
RTM_*LINK requests.
The new name is clearer and also aligns with the newly introduced
IFA_TARGET_NETNSID propert for RTM_*ADDR requests.
Signed-off-by: Christian Brauner <christian@brauner.io>
Suggested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Cc: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

I don't see how the type - which is one of
RTM_{GETADDR,GETROUTE,GETNETCONF} - can change. So do the message type
calculation once before entering the for loop.
Signed-off-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

- Backwards Compatibility:
  If userspace wants to determine whether ipv6 RTM_GETADDR requests
  support the new IFA_TARGET_NETNSID property it should verify that the
  reply includes the IFA_TARGET_NETNSID property. If it does not
  userspace should assume that IFA_TARGET_NETNSID is not supported for
  ipv6 RTM_GETADDR requests on this kernel.
- From what I gather from current userspace tools that make use of
  RTM_GETADDR requests some of them pass down struct ifinfomsg when they
  should actually pass down struct ifaddrmsg. To not break existing
  tools that pass down the wrong struct we will do the same as for
  RTM_GETLINK | NLM_F_DUMP requests and not error out when the
  nlmsg_parse() fails.

- Security:
  Callers must have CAP_NET_ADMIN in the owning user namespace of the
  target network namespace.
Signed-off-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

- Backwards Compatibility:
  If userspace wants to determine whether ipv4 RTM_GETADDR requests
  support the new IFA_TARGET_NETNSID property it should verify that the
  reply includes the IFA_TARGET_NETNSID property. If it does not
  userspace should assume that IFA_TARGET_NETNSID is not supported for
  ipv4 RTM_GETADDR requests on this kernel.
- From what I gather from current userspace tools that make use of
  RTM_GETADDR requests some of them pass down struct ifinfomsg when they
  should actually pass down struct ifaddrmsg. To not break existing
  tools that pass down the wrong struct we will do the same as for
  RTM_GETLINK | NLM_F_DUMP requests and not error out when the
  nlmsg_parse() fails.

- Security:
  Callers must have CAP_NET_ADMIN in the owning user namespace of the
  target network namespace.
Signed-off-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

This adds a new IFA_TARGET_NETNSID property to be used by address
families such as PF_INET and PF_INET6.
The IFA_TARGET_NETNSID property can be used to send a network namespace
identifier as part of a request. If a IFA_TARGET_NETNSID property is
identified it will be used to retrieve the target network namespace in
which the request is to be made.
Signed-off-by: Christian Brauner <christian@brauner.io>
Cc: Jiri Benc <jbenc@redhat.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

get_target_net() will be used in follow-up patches in ipv{4,6} codepaths to
retrieve network namespaces based on network namespace identifiers. So
remove the static declaration and export in the rtnetlink header. Also,
rename it to rtnl_get_net_ns_capable() to make it obvious what this
function is doing.
Export rtnl_get_net_ns_capable() so it can be used when ipv6 is built as
a module.
Signed-off-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Stefan Wahren says:

====================
net: lan78xx: Minor improvements

This patch series contains some minor improvements for the lan78xx
driver.

Changes in V2:
- Keep Copyright comment as multi-line
- Add Raghuram's Reviewed-by
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch makes some declaration more consistent.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Raghuram Chary Jallipalli <raghuramchary.jallipalli@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is no need for this strcpy because alloc_etherdev() already
does this job.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Raghuram Chary Jallipalli <raghuramchary.jallipalli@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We need to bail out if lan78xx_get_endpoints() fails, otherwise the
result is overwritten.

Fixes: 55d7de9d ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet")
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Raghuram Chary Jallipalli <raghuramchary.jallipalli@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

VXLAN and GRE FW features have to currently be both advertised
for the driver to enable them.  Separate the handling.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jakub Kicinski says:

====================
nfp: improve the new rtsym helpers

This set fixes a bug in ABS rtsym handling I added in net-next,
it expands the error checking and reporting on the rtsym accesses.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

With the accesses to rtsyms now all going via special helpers
we can easily make sure the driver is not reading past the
end of the symbol.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Francois H. Theron <francois.theron@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For ease of debug preface all error messages with the name
of the symbol which caused them.  Use the same message format
for existing messages while at it.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Francois H. Theron <francois.theron@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Return the error and report value through the output param.

Fixes: 640917dd ("nfp: support access to absolute RTsyms")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Francois H. Theron <francois.theron@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/net_failover.c: In function 'net_failover_slave_unregister':
drivers/net/net_failover.c:598:35: warning:
 variable 'primary_dev' set but not used [-Wunused-but-set-variable]

There should check the validity of 'slave_dev'.

Fixes: cfc80d9a ("net: Introduce net_failover driver")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As Linus noted, the test for 0 is needless, groups type can follow the
usual kernel style and 8*sizeof(unsigned long) is BITS_PER_LONG:

> The code [..] isn't technically incorrect...
> But it is stupid.
> Why stupid? Because the test for 0 is pointless.
>
> Just doing
>        if (nlk->ngroups < 8*sizeof(groups))
>                groups &= (1UL << nlk->ngroups) - 1;
>
> would have been fine and more understandable, since the "mask by shift
> count" already does the right thing for a ngroups value of 0. Now that
> test for zero makes me go "what's special about zero?". It turns out
> that the answer to that is "nothing".
[..]
> The type of "groups" is kind of silly too.
>
> Yeah, "long unsigned int" isn't _technically_ wrong. But we normally
> call that type "unsigned long".

Cleanup my piece of pointlessness.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: netdev@vger.kernel.org
Fairly-blamed-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, the only way to ignore outgoing packets on a packet socket is
via the BPF filter.  With MSG_ZEROCOPY, packets that are looped into
AF_PACKET are copied in dev_queue_xmit_nit(), and this copy happens even
if the filter run from packet_rcv() would reject them.  So the presence
of a packet socket on the interface takes away the benefits of
MSG_ZEROCOPY, even if the packet socket is not interested in outgoing
packets.  (Even when MSG_ZEROCOPY is not used, the skb is unnecessarily
cloned, but the cost for that is much lower.)

Add a socket option to allow AF_PACKET sockets to ignore outgoing
packets to solve this.  Note that the *BSDs already have something
similar: BIOCSSEESENT/BIOCSDIRECTION and BIOCSDIRFILT.

The first intended user is lldpd.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes the following sparse warning:

drivers/net/ethernet/microchip/lan743x_ptp.c:980:6: warning:
 symbol 'lan743x_ptp_set_sync_ts_insert' was not declared. Should it be static?
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes the following sparse warning:

drivers/net/ethernet/mellanox/mlx5/core/ipoib/ipoib.c:119:6: warning:
 symbol 'mlx5i_grp_sw_update_stats' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'mac80211-next-for-davem-2018-09-05' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next

Johannes Berg says:

====================
This time, we have some pretty impactful work. Among
the changes:
 * changes to make PTK rekeying work better, or actually
   better/safely if drivers get updated
 * VHT extended NSS support - some APs had capabilities
   that didn't fit into the VHT (11ac) spec, so the spec
   was updated and we follow that now
 * some TXQ and A-MSDU building work - will allow iwlwifi
   to use this soon
 * more HE work, including aligning to 802.11ax Draft 3.0
 * L-SIG and 0-length-PSDU support in radiotap
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add validation check for wmm rule when copy rules from fwdb and print
error when rule is invalid.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Both old and new cannot be NULL at the same time, hence checking
new when old is not NULL is unnecessary.

Also, notice that new is being dereferenced before it is checked:

	idx = new->conf.keyidx;

The above triggers a static code analysis warning.

Address this by removing the NULL check on new and adding a code
comment based on the following piece of code:

387        /* caller must provide at least one old/new */
388        if (WARN_ON(!new && !old))
389                return 0;

Addresses-Coverity-ID: 1473176 ("Dereference before null check")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Some hardwares have limitations on the packets' type in AMSDU.
Add an optional driver callback to determine if two skbs can
be used in the same AMSDU or not.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Some drivers may have AMSDU size limitation per TID, due to
HW constrains. Add an option to set this limit.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

We have a TXQ abstraction for non-data packets that need
powersave buffering. Since the AP cannot sleep, in case
of station we can use this TXQ for all management frames,
regardless if they are bufferable. Add HW flag to allow
that.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Align to new 11ax draft D3.0.  Change/add new MAC and PHY capabilities
and update drivers' 11ax capabilities and mac80211's debugfs
accordingly.
Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

After masking the he_oper_params, to get the requested values as
integers one must rshift and not lshift.  Fix that by using the
le32_get_bits() macro.

Fixes: 41cbb0f5 ("mac80211: add support for HE")
Signed-off-by: Naftali Goldstein <naftali.goldstein@intel.com>
[converted to use le32_get_bits()]
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

For certain sounding frames, it may be useful to report them
to userspace even though they don't have a PSDU in order to
determine the PHY parameters (e.g. VHT rate/stream config.)
Add support for this to mac80211.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Rekeying PTK keys without "Extended Key ID for Individually Addressed
Frames" did use a procedure not suitable to replace in-use keys and
could caused the following issues:

 1) Freeze caused by incoming frames:
    If the local STA installed the key prior to the remote STA we still
    had the old key active in the hardware when mac80211 switched over
    to the new key.
    Therefore there was a window where the card could hand over frames
    decoded with the old key to mac80211 and bump the new PN (IV) value
    to an incorrect high number. When it happened the local replay
    detection silently started to drop all frames sent with the new key.

 2) Freeze caused by outgoing frames:
    If mac80211 was providing the PN (IV) and handed over a clear text
    frame for encryption to the hardware prior to a key change the
    driver/card could have processed the queued frame after switching
    to the new key. This bumped the PN value on the remote STA to an
    incorrect high number, tricking the remote STA to discard all frames
    we sent later.

 3) Freeze caused by RX aggregation reorder buffer:
    An aggregation session started with the old key and ending after the
    switch to the new key also bumped the PN to an incorrect high number,
    freezing the connection quite similar to 1).

 4) Freeze caused by repeating lost frames in an aggregation session:
    A driver could repeat a lost frame and encrypt it with the new key
    while in a TX aggregation session without updating the PN for the
    new key. This also could freeze connections similar to 2).

 5) Clear text leak:
    Removing encryption offload from the card cleared the encryption
    offload flag only after the card had deleted the key and we did not
    stop TX during the rekey. The driver/card could therefore get
    unencrypted frames from mac80211 while no longer be instructed to
    encrypt them.

To prevent those issues the key install logic has been changed:
 - Mac80211 divers known to be able to rekey PTK0 keys have to set
   @NL80211_EXT_FEATURE_CAN_REPLACE_PTK0,
 - mac80211 stops queuing frames depending on the key during the replace
 - the key is first replaced in the hardware and after that in mac80211
 - and mac80211 stops/blocks new aggregation sessions during the rekey.

For drivers not setting
@NL80211_EXT_FEATURE_CAN_REPLACE_PTK0 the user space must avoid PTK
rekeys if "Extended Key ID for Individually Addressed Frames" is not
being used. Rekeys for mac80211 drivers without this flag will generate a
warning and use an extra call to ieee80211_flush_queues() to both
highlight and try to prevent the issues with not updated drivers.

The core of the fix changes the key install procedure from:
 - atomic switch over to the new key in mac80211
 - remove the old key in the hardware (stops encryption offloading, fall
   back to software encryption with a potential clear text packet leak
   in between)
 - delete the inactive old key in mac80211
 - enable hardware encryption offloading for the new key
to:
 - if it's a PTK mark the old key as tainted to drop TX frames with the
   outgoing key
 - replace the key in hardware with the new one
 - atomic switch over to the new (not marked as tainted) key in
   mac80211 (which also resumes TX)
 - delete the inactive old key in mac80211

With the new sequence the hardware will be unable to decrypt frames
encrypted with the old key prior to switching to the new key in mac80211
and thus prevent PNs from packets decrypted with the old key to be
accounted against the new key.

For that to work the drivers have to provide a clear boundary.
Mac80211 drivers setting @NL80211_EXT_FEATURE_CAN_REPLACE_PTK0 confirm
to provide it and mac80211 will then be able to correctly rekey in-use
PTK keys with those drivers.

The mac80211 requirements for drivers to set the flag have been added to
the "Hardware crypto acceleration" documentation section. It drills down
to:
The drivers must not hand over frames decrypted with the old key to
mac80211 once the call to set_key() with %DISABLE_KEY has been
completed. It's allowed to either drop or continue to use the old key
for any outgoing frames which are already in the queues, but it must not
send out any of them unencrypted or encrypted with the new key.

Even with the new boundary in place aggregation sessions with the
reorder buffer are problematic:
RX aggregation session started prior and completed after the rekey could
still dump frames received with the old key at mac80211 after it
switched over to the new key. This is side stepped by stopping all (RX
and TX) aggregation sessions when replacing a PTK key and hardware key
offloading.
Stopping TX aggregation sessions avoids the need to get
the PNs (IVs) updated in frames prepared for the old key and
(re)transmitted after the switch to the new key. As a bonus it improves
the compatibility when the remote STA is not handling rekeys as it
should.

When using software crypto aggregation sessions are not stopped.
Mac80211 won't be able to decode the dangerous frames and discard them
without special handling.
Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
[trim overly long rekey warning]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Drivers able to correctly replace a in-use key should set
@NL80211_EXT_FEATURE_CAN_REPLACE_PTK0 to allow the user space (e.g.
hostapd or wpa_supplicant) to rekey PTK keys.

The user space must detect a PTK rekey attempt and only go ahead with it
when the driver has set this flag. If the driver is not supporting the
feature the user space either must not replace the PTK key or perform a
full re-association instead.

Ignoring this flag and continuing to rekey the connection can still work
but has to be considered insecure and broken. Depending on the driver it
can leak clear text packets or freeze the connection and is only
supported to allow the user space to be updated.
Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
Reviewed-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>