Build bot points out that I missed initializing ret
after refactoring.
Reported-by: Nkernel test robot <lkp@intel.com>
Fixes: 1c401078 ("netdevsim: move details of vf config to dev")
Link: https://lore.kernel.org/r/20211101221845.3188490-1-kuba@kernel.orgSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Rename functions serving as driver entry points
from nsim_dev_... to nsim_drv_... this makes the
API boundary between bus and dev clearer.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

max_vfs is a strange little beast because the file
hangs off of nsim's debugfs, but it configures a field
in the bus device. Move it to dev.c, let's look at it
as if the device driver was imposing VF limit based
on FW info (like pci_sriov_set_totalvfs()).

Again, when moving refactor the function not to hold
the vfs lock pointlessly while parsing the input.
Wrap the access from the read side in READ_ONCE()
to appease concurrency checkers. Do not check if
return value from snprintf() is negative...
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since "eswitch" configuration was added bus.c contains
a lot of device details which really belong to dev.c.

Restructure the code while moving it.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When netdevsim got split into the faux bus vfconfig ended
up in the bus device (think pci_dev) which is strange because
it contains very networky not to say netdevy information.
Move it to nsim_dev, which is the driver "priv" structure
for the device.

To make sure we don't race with probe/remove take
the device lock (much like PCI).

While at it remove the NULL-checking of vfconfigs.
It appears to be pointless.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Legacy VF NDOs look at num_vfs and then based on that
index into vfconfig. If we don't rtnl_lock() num_vfs
may get set to 0 and vfconfig freed/replaced while
the NDO is running.

We don't need to protect replacing vfconfig since it's
only done when num_vfs is 0.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit d3953819 ("netdevsim: Add max_vfs to bus_dev")
added this file and saved the dentry for no apparent reason.

Link: https://lore.kernel.org/r/20211028211753.22612-1-kuba@kernel.orgSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Commit a0c76345 ("devlink: disallow reload operation during device
cleanup") added devlink_reload_{enable,disable}() APIs to prevent reload
operation from racing with device probe/dismantle.

After recent changes to move devlink_register() to the end of device
probe and devlink_unregister() to the beginning of device dismantle,
these races can no longer happen. Reload operations will be denied if
the devlink instance is unregistered and devlink_unregister() will block
until all in-flight operations are done.

Therefore, remove these devlink_reload_{enable,disable}() APIs.
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Introduce new devlink call to set feature mask to control devlink
behavior during device initialization phase after devlink_alloc()
is already called.

This allows us to set reload ops based on device property which
is not known at the beginning of driver initialization.

For the sake of simplicity, this API lacks any type of locking and
needs to be called before devlink_register() to make sure that no
parallel access to the ops is possible at this stage.
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

This change prevents from users to access device before devlink is
fully configured.
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

devlink_register() can't fail and always returns success, but all drivers
are obligated to check returned status anyway. This adds a lot of boilerplate
code to handle impossible flow.

Make devlink_register() void and simplify the drivers that use that
API call.
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Acked-by: NSimon Horman <simon.horman@corigine.com>
Acked-by: Vladimir Oltean <olteanv@gmail.com> # dsa
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Devlink core exported generously the functions calls that were used
by netdevsim tests or not used at all.

Delete such APIs with one exception - devlink_alloc_ns(). That function
should be spared from deleting because it is a special form of devlink_alloc()
needed for the netdevsim.
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Acked-by: NJakub Kicinski <kuba@kernel.org>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For testing visibility of mq/mqprio default children.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to support more coalesce parameters through netlink,
add two new parameter kernel_coal and extack for .set_coalesce
and .get_coalesce, then some extra info can return to user with
the netlink API.
Signed-off-by: NYufeng Mo <moyufeng@huawei.com>
Signed-off-by: NHuazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

All kernel devlink implementations call to devlink_alloc() during
initialization routine for specific device which is used later as
a parent device for devlink_register().

Such late device assignment causes to the situation which requires us to
call to device_register() before setting other parameters, but that call
opens devlink to the world and makes accessible for the netlink users.

Any attempt to move devlink_register() to be the last call generates the
following error due to access to the devlink->dev pointer.

[    8.758862]  devlink_nl_param_fill+0x2e8/0xe50
[    8.760305]  devlink_param_notify+0x6d/0x180
[    8.760435]  __devlink_params_register+0x2f1/0x670
[    8.760558]  devlink_params_register+0x1e/0x20

The simple change of API to set devlink device in the devlink_alloc()
instead of devlink_register() fixes all this above and ensures that
prior to call to devlink_register() everything already set.
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't progress with adding and deleting ports as long as devlink
reload is running.

Fixes: 23809a72 ("netdevsim: Forbid devlink reload when adding or deleting ports")
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to remove complexity in devlink core related to
devlink_reload_enable/disable, let's rewrite new_port/del_port
logic to rely on internal to netdevsim lcok.

We should protect only reload_down flow because it destroys nsim_dev,
which is needed for nsim_dev_port_add/nsim_dev_port_del to hold
port_list_lock.
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't populate the array res_ids on the stack but instead it
static const. Makes the object code smaller by 14 bytes.

Before:
   text    data     bss     dec     hex filename
  50833    8314     256   59403    e80b ./drivers/net/netdevsim/fib.o

After:
   text    data     bss     dec     hex filename
  50755    8378     256   59389    e7fd ./drivers/net/netdevsim/fib.o

(gcc version 10.2.0)
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210801065328.138906-1-colin.king@canonical.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

There is no need in extra call indirection and check from impossible
flow where someone tries to set namespace without prior call
to devlink_alloc().

Instead of this extra logic and additional EXPORT_SYMBOL, use specialized
devlink allocation function that receives net namespace as an argument.

Such specialized API allows clear view when devlink initialized in wrong
net namespace and/or kernel users don't try to change devlink namespace
under the hood.
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.

With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.

Reviewed-by: Tom Rix <trix@redhat.com> (For fpga)
Reviewed-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts)
Acked-by: NMark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: NPali Rohár <pali@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media)
Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform)
Acked-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: NVinod Koul <vkoul@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com> (For xen)
Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd)
Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb)
Acked-by: NJohan Hovold <johan@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus)
Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio)
Acked-by: NMaximilian Luz <luzmaximilian@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack)
Acked-by: Geoff Levand <geoff@infradead.org> (For ps3)
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt)
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th)
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia)
Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI)
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid)
Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa)
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire)
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid)
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox)
Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss)
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC)
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: NFinn Thain <fthain@linux-m68k.org>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently netdevsim only supports a single queue per port, which is
insufficient for testing multi-queue TC schedulers e.g. sch_mq.  Extend
the current sysfs interface so that users can create ports with multiple
queues:

$ echo "[ID] [PORT_COUNT] [NUM_QUEUES]" > /sys/bus/netdevsim/new_device

As an example, echoing "2 4 8" creates 4 ports, with 8 queues per port.
Note, this is compatible with the current interface, with default number
of queues set to 1.  For example, echoing "2 4" creates 4 ports with 1
queue per port; echoing "2" simply creates 1 port with 1 queue.
Reviewed-by: NCong Wang <cong.wang@bytedance.com>
Signed-off-by: NPeilin Ye <peilin.ye@bytedance.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are two pointers in struct xfrm_state_offload, *dev, *real_dev.
These are used in callback functions of struct xfrmdev_ops.
The *dev points whether bonding interface or real interface.
If bonding ipsec offload is used, it points bonding interface If not,
it points real interface.
And real_dev always points real interface.
So, netdevsim should always use real_dev instead of dev.
Of course, real_dev always not be null.

Test commands:
    ip netns add A
    ip netns exec A bash
    modprobe netdevsim
    echo "1 1" > /sys/bus/netdevsim/new_device
    ip link add bond0 type bond mode active-backup
    ip link set eth0 master bond0
    ip link set eth0 up
    ip link set bond0 up
    ip x s add proto esp dst 14.1.1.1 src 15.1.1.1 spi 0x07 mode \
transport reqid 0x07 replay-window 32 aead 'rfc4106(gcm(aes))' \
0x44434241343332312423222114131211f4f3f2f1 128 sel src 14.0.0.52/24 \
dst 14.0.0.70/24 proto tcp offload dev bond0 dir in

Splat looks like:
BUG: spinlock bad magic on CPU#5, kworker/5:1/53
 lock: 0xffff8881068c2cc8, .magic: 11121314, .owner: <none>/-1,
.owner_cpu: -235736076
CPU: 5 PID: 53 Comm: kworker/5:1 Not tainted 5.13.0-rc3+ #1168
Workqueue: events linkwatch_event
Call Trace:
 dump_stack+0xa4/0xe5
 do_raw_spin_lock+0x20b/0x270
 ? rwlock_bug.part.1+0x90/0x90
 _raw_spin_lock_nested+0x5f/0x70
 bond_get_stats+0xe4/0x4c0 [bonding]
 ? rcu_read_lock_sched_held+0xc0/0xc0
 ? bond_neigh_init+0x2c0/0x2c0 [bonding]
 ? dev_get_alias+0xe2/0x190
 ? dev_get_port_parent_id+0x14a/0x360
 ? rtnl_unregister+0x190/0x190
 ? dev_get_phys_port_name+0xa0/0xa0
 ? memset+0x1f/0x40
 ? memcpy+0x38/0x60
 ? rtnl_phys_switch_id_fill+0x91/0x100
 dev_get_stats+0x8c/0x270
 rtnl_fill_stats+0x44/0xbe0
 ? nla_put+0xbe/0x140
 rtnl_fill_ifinfo+0x1054/0x3ad0
[ ... ]

Fixes: 272c2330 ("xfrm: bail early on slave pass over skb")
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

devlink_trap tests for the netdevsim fail due to misspelled
debugfs file name. Change this name, as well as name of callback
function, to match the naming as in the devlink itself - 'trap_drop_counter'.

Test-results:
selftests: drivers/net/netdevsim: devlink_trap.sh
TEST: Initialization                                                [ OK ]
TEST: Trap action                                                   [ OK ]
TEST: Trap metadata                                                 [ OK ]
TEST: Non-existing trap                                             [ OK ]
TEST: Non-existing trap action                                      [ OK ]
TEST: Trap statistics                                               [ OK ]
TEST: Trap group action                                             [ OK ]
TEST: Non-existing trap group                                       [ OK ]
TEST: Trap group statistics                                         [ OK ]
TEST: Trap policer                                                  [ OK ]
TEST: Trap policer binding                                          [ OK ]
TEST: Port delete                                                   [ OK ]
TEST: Device delete                                                 [ OK ]

Fixes: a7b3527a ("drivers: net: netdevsim: add devlink trap_drop_counter_get implementation")
Signed-off-by: NOleksandr Mazur <oleksandr.mazur@plvision.eu>
Reviewed-by: NIdo Schimmel <idosch@nvidia.com>
Tested-by: NIdo Schimmel <idosch@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Whenever query statistics is issued for trap with DROP action,
devlink subsystem would also fill-in statistics 'dropped' field.
In case if device driver did't register callback for hard drop
statistics querying, 'dropped' field will be omitted and not filled.
Add trap_drop_counter_get callback implementation to the netdevsim.
Add new test cases for netdevsim, to test both the callback
functionality, as well as drop statistics alteration check.
Signed-off-by: NOleksandr Mazur <oleksandr.mazur@plvision.eu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In normal situations where the driver doesn't dereference
"nsim_node->ddir" or "nsim_node->rate_parent" itself then we are not
supposed to check the return from debugfs functions.  In the case of
debugfs_create_dir() the check was wrong as well because it doesn't
return NULL, it returns error pointers.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The comparison of len < 0 is always false because len is a size_t. Fix
this by making len a ssize_t instead.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: d3953819 ("netdevsim: Add max_vfs to bus_dev")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement new devlink ops that allow setting rate node as a parent for
devlink port (leaf) or another devlink node through devlink API.
Expose parent names to netdevsim debugfs in read only mode.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement new devlink ops that allow creation, deletion and setting of
shared/max tx rate of devlink rate nodes through devlink API.
Expose rate node and it's tx rates to netdevsim debugfs.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement new devlink ops that allow shared and max tx rate control for
devlink port rate objects (leafs) through devlink API.

Expose rate values of VF ports to netdevsim debugfs.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Register devlink rate leaf objects per VF.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement callbacks to set/get eswitch mode value. Add helpers to check
current mode.

Instantiate VFs' net devices and devlink ports on switchdev enabling and
remove them on legacy enabling. Changing number of VFs while in
switchdev mode triggers VFs creation/deletion.

Also disable NDO API callback to set VF rate, since it's legacy API.
Switchdev API to set VF rate will be implemented in one of the next
patches.
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow creation of netdevsim ports for VFs along with allocations of
corresponding net devices and devlink ports.
Add enums and helpers to distinguish PFs' ports from VFs' ports.

Ports creation/deletion debugfs API intended to be used with physical
ports only.
VFs instantiation will be done in one of the next patches.
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Define type of ports, which netdevsim driver currently operates with as
PF. Define new port type - VF, which will be implemented in following
patches. Add helper functions to distinguish them. Add helper function
to get VF index from port index.

Add port indexing logic where PFs' indexes starts from 0, VFs' - from
NSIM_DEV_VF_PORT_INDEX_BASE.
All ports uses same index pool, which means that PF port may be created
with index from VFs' indexes range.
Maximum number of VFs, which the driver can allocate, is limited by
UINT_MAX - BASE.
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move VFs disabling from device release() to nsim_dev_reload_destroy() to
make VFs disabling and ports removal simultaneous.
This is a requirement for VFs ports implemented in next patches.
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently there is no limit to the number of VFs netdevsim can enable.
In a real systems this value exist and used by the driver.
Fore example, some features might need to consider this value when
allocating memory.

Expose max_vfs variable to debugfs as configurable resource. If are VFs
configured (num_vfs != 0) then changing of max_vfs not allowed.
Co-developed-by: NYuval Avnery <yuvalav@nvidia.com>
Signed-off-by: NYuval Avnery <yuvalav@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the sampling truncation length is invalid (zero), pass the length
of the packet. Without the fix, no payload is reported to user space
when the truncation length is zero.

Fixes: a8700c3d ("netdevsim: Add dummy psample implementation")
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Acked-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Eliminate the following coccicheck warning:
 drivers/net/netdevsim/fib.c:569:2-3: Unneeded semicolon
Signed-off-by: NQiheng Lin <linqiheng@huawei.com>
Acked-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for ethtool FEC and some ethtool error injection.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use memdup_user_nul() helper instead of open-coding to
simplify the code.
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow netdevsim to report "sampled" packets to the psample module by
periodically generating packets from a work queue. The behavior can be
enabled / disabled (default) and the various meta data attributes can be
controlled via debugfs knobs.

This implementation enables both testing of the psample module with all
the optional attributes as well as development of user space
applications on top of psample such as hsflowd and a Wireshark dissector
for psample generic netlink packets.
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>