Currently, when doing rate limiting using the tc-police(8) action, the
easiest way is to simply drop the packets which exceed or conform the
configured bandwidth limit.  Add a new option to tc-skbmod(8), so that
users may use the ECN [1] extension to explicitly inform the receiver
about the congestion instead of dropping packets "on the floor".

The 2 least significant bits of the Traffic Class field in IPv4 and IPv6
headers are used to represent different ECN states [2]:

	0b00: "Non ECN-Capable Transport", Non-ECT
	0b10: "ECN Capable Transport", ECT(0)
	0b01: "ECN Capable Transport", ECT(1)
	0b11: "Congestion Encountered", CE

As an example:

	$ tc filter add dev eth0 parent 1: protocol ip prio 10 \
		matchall action skbmod ecn

Doing the above marks all ECT(0) and ECT(1) packets as CE.  It does NOT
affect Non-ECT or non-IP packets.  In the tc-police scenario mentioned
above, users may pipe a tc-police action and a tc-skbmod "ecn" action
together to achieve ECN-based rate limiting.

For TCP connections, upon receiving a CE packet, the receiver will respond
with an ECE packet, asking the sender to reduce their congestion window.
However ECN also works with other L4 protocols e.g. DCCP and SCTP [2], and
our implementation does not touch or care about L4 headers.

The updated tc-skbmod SYNOPSIS looks like the following:

	tc ... action skbmod { set SETTABLE | swap SWAPPABLE | ecn } ...

Only one of "set", "swap" or "ecn" shall be used in a single tc-skbmod
command.  Trying to use more than one of them at a time is considered
undefined behavior; pipe multiple tc-skbmod commands together instead.
"set" and "swap" only affect Ethernet packets, while "ecn" only affects
IPv{4,6} packets.

It is also worth mentioning that, in theory, the same effect could be
achieved by piping a "police" action and a "bpf" action using the
bpf_skb_ecn_set_ce() helper, but this requires eBPF programming from the
user, thus impractical.

Depends on patch "net/sched: act_skbmod: Skip non-Ethernet packets".

[1] https://datatracker.ietf.org/doc/html/rfc3168
[2] https://en.wikipedia.org/wiki/Explicit_Congestion_NotificationReviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If nfp_tunnel_add_ipv6_off() fails, it should return error code
in nfp_fl_ct_add_offload().

Fixes: 5a2b9304 ("nfp: flower-ct: compile match sections of flow_payload")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Leon Romanovsky says:

====================
Remove duplicated devlink registration check

Changelog:
v1:
 * Added two new patches that remove registration field from mlx5 and ti drivers.
v0: https://lore.kernel.org/lkml/ed7bbb1e4c51dd58e6035a058e93d16f883b09ce.1627215829.git.leonro@nvidia.com

--------------------------------------------------------------------

Both registered flag and devlink pointer are set at the same time
and indicate the same thing - devlink/devlink_port are ready. Instead
of checking ->registered use devlink pointer as an indication.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Both registered flag and devlink pointer are set at the same time
and indicate the same thing - devlink/devlink_port are ready. Instead
of checking ->registered use devlink pointer as an indication.
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Devlink is an integral part of mlx5 driver and all flows ensure that
devlink_*_register() will success. That makes the ->registered check
an obsolete.
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The commit that introduced devlink support released devlink resources in
wrong order, that made an unwind flow to be asymmetrical. In addition,
the am65-cpsw-nuss used internal to devlink core field - registered.

In order to fix the unwind flow and remove such access to the
registered field, rewrite the code to call devlink_port_unregister only
on registered ports.

Fixes: 58356eb3 ("net: ti: am65-cpsw-nuss: Add devlink support")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alex Elder says:

====================
net: ipa: add clock references

This series continues preparation for implementing runtime power
management for IPA.  We need to ensure that the IPA core clock and
interconnects are operational whenever IPA hardware is accessed.
And in particular this means that any external entry point that can
lead to accessing IPA hardware must guarantee the hardware is "up"
when it is accessed.

The first four patches in this series take IPA clock references when
needed by such external entry points, dropping those references in
those same functions when they are no longer required.

The last patch is a bit different, though it too prepares for
enabling runtime power management.  It avoids suspending/resuming
endpoints if setup is not complete.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Until we complete the setup stage of initialization, GSI is not
initialized and therefore endpoints aren't usable.  So avoid
suspending endpoints during system suspend unless setup is complete.

Clear the setup_complete flag at the top of ipa_teardown() to
reflect the fact that things are no longer in setup state.

Get rid of a misplaced (and superfluous) comment.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The IPA network device can be opened at any time, and an opened
network device can be stopped any time.  Both of these callback
functions require access to the hardware, and therefore they need
the IPA clock to be operational.  Take an IPA clock reference in
both the ->open and ->stop callback functions, dropping the
reference when they are done accessing hardware.

The ->start_xmit callback requires a little different handling,
and that will be added separately.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The remoteproc SSR callback function for the modem requires hardware
access when handling a modem crash or shutdown.  Take and later
release an IPA clock reference in ipa_modem_crashed(), to ensure the
hardware is operational.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Two places call ipa_setup().  The first, ipa_probe(), holds an IPA
clock reference when calling ipa_setup() (if the AP is responsible
for IPA firmware loading).  But if the modem is loading IPA
firmware, ipa_smp2p_modem_setup_ready_isr() calls ipa_setup() after
the modem has signaled the hardware is ready.  This can happen at
any time, and there is no guarantee the hardware is active.

Have ipa_smp2p_modem_setup() take an IPA clock reference before it
calls ipa_setup(), and release it once setup is complete.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Any entry point that leads to IPA hardware access must ensure the
hardware is operational (clocked).  Currently we ensure this by
taking an extra clock reference during setup that is not released
until we receive a system suspend request.  But this extra reference
will soon go away.

When the platform driver ->probe function is called, we first need
hardware access in ipa_config().  Although ipa_config() takes an IPA
clock reference, it the special reference taken to prevent suspending
the hardware.

Have ipa_probe() take a reference before calling ipa_config(), so
that the "no-suspend" reference can eventually go away.  Drop this
reference before ipa_probe() returns.

Similarly, the driver ->remove function can be called at any time.
Take an IPA clock reference at the beginning of that function, and
drop it again after the deconfig stage has completed (at which point
hardware access is no longer needed).
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alex Elder says:

====================
net: ipa: IPA interrupt cleanup

The first patch in this series makes all IPA interrupt handling be
done in a threaded context.  The remaining ones refactor some code
to simplify that threaded handler function.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that ipa_isr_thread() is a simple wrapper that gets a clock
reference around ipa_interrupt_process_all(), get rid of the
called function and just open-code it in ipa_isr_thread().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The pending IPA interrupts are checked by ipa_isr_thread(), and
interrupts are processed only if an enabled interrupt has a
condition pending.  But ipa_interrupt_process_all() now makes the
same check, so the one in ipa_isr_thread() can just be skipped.

Also in ipa_isr_thread(), any interrupt conditions pending which are
not enabled are cleared.  Here too, ipa_interrupt_process_all() now
clears such excess interrupt conditions, so ipa_isr_thread() doesn't
have to.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

We ignore any IPA interrupt that has no handler.  If any interrupt
conditions without a handler exist when an IPA interrupt occurs,
clear those conditions.  Add a debug message to report which ones
are being cleared.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

When the IPA interrupt handler runs, the IPA core clock must already
be operational, and the interconnect providing access by the AP to
IPA config space must be enabled too.

Currently we ensure this by taking a top-level "stay awake" IPA
clock reference, but that will soon go away.  In preparation for
that, move all handling for the IPA IRQ into the thread function.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Syzbot reported warning in netlbl_cipsov4_add(). The
problem was in too big doi_def->map.std->lvl.local_size
passed to kcalloc(). Since this value comes from userpace there is
no need to warn if value is not correct.

The same problem may occur with other kcalloc() calls in
this function, so, I've added __GFP_NOWARN flag to all
kcalloc() calls there.

Reported-and-tested-by: syzbot+cdd51ee2e6b0b2e18c0d@syzkaller.appspotmail.com
Fixes: 96cb8e33 ("[NetLabel]: CIPSOv4 and Unlabeled packet integration")
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Shannon Nelson says:

====================
ionic: driver updates 27-July-2021

This is a collection of small driver updates for adding a couple of
small features and for a bit of code cleaning.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Prefix the log output with the function string as in other
debug messages.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

If there's only one queue, there is no need to enable
the rxhashing.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

There are a few things that we can't safely do when the fw is
resetting, as the driver may be in the middle of rebuilding
queue structures.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

We don't use these fields, so remove them from
the definition.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add the new VF to our internal count before we start configuring it.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Based on Alex's review notes on [1], we don't need to write
to the buf_info elements as often, and can tighten up how they
are used.  Also, use prefetchw() to warm up the page struct
for a later get_page().

[1] https://lore.kernel.org/netdev/CAKgT0UfyjoAN7LTnq0NMZfXRv4v7iTCPyAb9pVr3qWMhop_BVw@mail.gmail.com/Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Initialize err to 0 instead of ENOMEM, and specifically set
err to ENOMEM in the devm_kcalloc() failure cases.

Also, add an error message to the end of reconfig.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Print the version of the DSC firmware seen when we do a fresh
ident check.  Because the FW can be updated by the external
orchestration system, this helps us track that FW has been
updated on the DSC.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

The top 4 bits of the fw_status in dev_info_regs is reserved
for the status generation.  This generation number is an
arbitrary value defined when firmware starts up.  If the FW
is killed/crashed/stopped and then restarted, it will create
a different generation number.  With this mechanism, the host
driver can detect that the FW has crashed and restarted, and
the driver can then take steps to re-initialize its connection.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

When running in a small kdump kernel, we can play nice and
minimize our resource use to help make sure that kdump is
successful in its mission.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Arnd Bergmann says:

====================
ndo_ioctl rework

This series is a follow-up to the series for removing
compat_alloc_user_space() and copy_in_user() that has now
been merged.

I wanted to be sure I address all the ways that 'struct ifreq' is used
in device drivers through .ndo_do_ioctl, originally to prove that
my approach of changing the struct definition was correct, but then
I discarded that approach and went on anyway.

Roughly, the contents here are:

 - split out all the users of SIOCDEVPRIVATE ioctls into a
   separate ndo_siocdevprivate callback, to better see what
   gets used where

 - fix compat handling for those drivers that pass data
   directly inside of 'ifreq' rather than using an indirect
   ifr_data pointer

 - remove unreachable code in ndo_ioctl handlers that relies
   on command codes we never pass into that, in particular
   for wireless drivers

 - split out the ethernet specific ioctls into yet another
   ndo_eth_ioctl callback, as these are by far the most
   common use of ndo_do_ioctl today. I considered splitting
   them further into MII and timestamp controls, but
   went with the simpler change for now.

 - split out bonding and wandev ioctls into separate helpers

 - rework the bridge handling with a separate callback

At this point, only a few oddball things remain in ndo_do_ioctl:
appletalk and ieee802154 pass down SIOCSIFADDR/SIOCGIFADDR and
some wireless drivers have completely dead code.

I have thoroughly compile tested this on randconfig builds,
but not done any notable runtime testing, so please review.
All of it is also available as part of a larger branch at

https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git \
	compat-alloc-user-space-12

Changes since v2:
- rebase to net-next
- fix qeth regression
- Cc driver maintainers for each patch and in cover letter

Changes since v1:

- rebase to linux-5.14-rc2
- add conversion for ndo_siowandev, bridge and bonding drivers
- leave broken wifi drivers untouched for now

Link: https://lore.kernel.org/netdev/20201106221743.3271965-14-arnd@kernel.org/
====================

All other user triggered operations are gone from ndo_ioctl, so move
the SIOCBOND family into a custom operation as well.

The .ndo_ioctl() helper is no longer called by the dev_ioctl.c code now,
but there are still a few definitions in obsolete wireless drivers as well
as the appletalk and ieee802154 layers to call SIOCSIFADDR/SIOCGIFADDR
helpers from inside the kernel.

Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Working towards obsoleting the .ndo_do_ioctl operation entirely,
stop passing the SIOCBRADDIF/SIOCBRDELIF device ioctl commands
into this callback.

My first attempt was to add another ndo_siocbr() callback, but
as there is only a single driver that takes these commands and
there is already a hook mechanism to call directly into this
driver, extend this hook instead, and use it for both the
deviceless and the device specific ioctl commands.

Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: Nikolay Aleksandrov <nikolay@nvidia.com>
Cc: bridge@lists.linux-foundation.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some drivers that use SIOCDEVPRIVATE ioctl commands modify
the ifreq structure and expect it to be passed back to user
space, which has never really happened for compat mode
because the calling these drivers through ndo_do_ioctl
requires overwriting the ifr_data pointer.

Now that all drivers are converted to ndo_siocdevprivate,
change it to handle this correctly in both compat and
native mode.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

In order to further reduce the scope of ndo_do_ioctl(), move
out the SIOCWANDEV handling into a new network device operation
function.

Adjust the prototype to only pass the if_settings sub-structure
in place of the ifreq, and remove the redundant 'cmd' argument
in the process.

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Cc: Kevin Curtis <kevin.curtis@farsite.co.uk>
Cc: Zhao Qiang <qiang.zhao@nxp.com>
Cc: Martin Schiller <ms@dev.tdt.de>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: linux-x25@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Most users of ndo_do_ioctl are ethernet drivers that implement
the MII commands SIOCGMIIPHY/SIOCGMIIREG/SIOCSMIIREG, or hardware
timestamping with SIOCSHWTSTAMP/SIOCGHWTSTAMP.

Separate these from the few drivers that use ndo_do_ioctl to
implement SIOCBOND, SIOCBR and SIOCWANDEV commands.

This is a purely cosmetic change intended to help readers find
their way through the implementation.

Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Vivien Didelot <vivien.didelot@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Vladimir Oltean <olteanv@gmail.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The compat handlers for SIOCDEVPRIVATE are incorrect for any driver that
passes data as part of struct ifreq rather than as an ifr_data pointer, or
that passes data back this way, since the compat_ifr_data_ioctl() helper
overwrites the ifr_data pointer and does not copy anything back out.

Since all drivers using devprivate commands are now converted to the
new .ndo_siocdevprivate callback, fix this by adding the missing piece
and passing the pointer separately the whole way.

This further unifies the native and compat logic for socket ioctls,
as the new code now passes the correct pointer as well as the correct
data for both native and compat ioctls.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The ndo_do_ioctl callback is never called with the COSAIO* commands,
so this is never used. Call the hdlc_ioctl function directly instead.

Any user space code that relied on this function working as intended
has never worked in a mainline kernel since before linux-1.0.

Cc: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The wan drivers each support some custom SIOCDEVPRIVATE
ioctls, plus the common SIOCWANDEV command.

Split these so the ioctl callback only deals with SIOCWANDEV
and the rest is handled by ndo_siocdevprivate.

It might make sense to also split out SIOCWANDEV into a
separate callback in order to eventually remove ndo_do_ioctl
entirely.

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Kevin Curtis <kevin.curtis@farsite.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

ppp has a custom statistics interface using SIOCDEVPRIVATE
ioctl commands that works correctly in compat mode.

Convert it to use ndo_siocdevprivate as a cleanup.

Cc: Paul Mackerras <paulus@samba.org>
Cc: linux-ppp@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The private sb1000 ioctl commands all work correctly in
compat mode. Change the to ndo_siocdevprivate as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>