Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates 2020-02-19

This series contains fixes to the ice driver.

Brett fixes an issue where if a user sets an odd [tx|rx]-usecs value
through ethtool, the request is denied because the hardware is set to
have an ITR with 2us granularity.  Also fix an issue where the VF has
not been completely removed/reset after being unbound from the host
driver, so resolve this by waiting for the VF remove/reset process to
happen before checking if the VF is disabled.

Michal fixes an issue, where when the user changes flow control via
ethtool, the OS is told the link is going down when that may not be the
case.  Before the fix, the only way to get out of this state was to take
the interface down and up again.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

As of the below commit, udp sockets bound to a specific address can
coexist with one bound to the any addr for the same port.

The commit also phased out the use of socket hashing based only on
port (hslot), in favor of always hashing on {addr, port} (hslot2).

The change broke the following behavior with disconnect (AF_UNSPEC):

    server binds to 0.0.0.0:1337
    server connects to 127.0.0.1:80
    server disconnects
    client connects to 127.0.0.1:1337
    client sends "hello"
    server reads "hello"	// times out, packet did not find sk

On connect the server acquires a specific source addr suitable for
routing to its destination. On disconnect it reverts to the any addr.

The connect call triggers a rehash to a different hslot2. On
disconnect, add the same to return to the original hslot2.

Skip this step if the socket is going to be unhashed completely.

Fixes: 4cdeeee9 ("net: udp: prefer listeners bound to an address")
Reported-by: Pavel Roskin <plroskin@gmail.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Current code doesn't check if tcp sequence number is starting from (/after)
1st record's start sequnce number. It only checks if seq number is before
1st record's end sequnce number. This problem will always be a possibility
in re-transmit case. If a record which belongs to a requested seq number is
already deleted, tls_get_record will start looking into list and as per the
check it will look if seq number is before the end seq of 1st record, which
will always be true and will return 1st record always, it should in fact
return NULL.
As part of the fix, start looking each record only if the sequence number
lies in the list else return NULL.
There is one more check added, driver look for the start marker record to
handle tcp packets which are before the tls offload start sequence number,
hence return 1st record if the record is tls start marker and seq number is
before the 1st record's starting sequence number.

Fixes: e8f69799 ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The configuration/command below is failing when the VF in the xml
file is already bound to the host iavf driver.

pci_0000_af_0_0.xml:

<interface type='hostdev' managed='yes'>
<source>
<address type='pci' domain='0x0000' bus='0xaf' slot='0x0' function='0x0'/>
</source>
<mac address='00:de:ad:00:11:01'/>
</interface>

> virsh attach-device domain_name pci_0000_af_0_0.xml
error: Failed to attach device from pci_0000_af_0_0.xml
error: Cannot set interface MAC/vlanid to 00:de:ad:00:11:01/0 for
	ifname ens1f1 vf 0: Device or resource busy

This is failing because the VF has not been completely removed/reset
after being unbound (via the virsh command above) from the host iavf
driver and ice_set_vf_mac() checks if the VF is disabled before waiting
for the reset to finish.

Fix this by waiting for the VF remove/reset process to happen before
checking if the VF is disabled. Also, since many functions for VF
administration on the PF were more or less calling the same 3 functions
(ice_wait_on_vf_reset(), ice_is_vf_disabled(), and ice_check_vf_init())
move these into the helper function ice_check_vf_ready_for_cfg(). Then
call this function in any flow that attempts to configure/query a VF
from the PF.

Lastly, increase the maximum wait time in ice_wait_on_vf_reset() to
800ms, and modify/add the #define(s) that determine the wait time.
This was done for robustness because in rare/stress cases VF removal can
take a max of ~800ms and previously the wait was a max of ~300ms.
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Remove code that tell the OS that link is going down when user
change flow control via ethtool. When link is up it isn't certain
that link goes down after 0x0605 aq command. If link doesn't go
down, OS thinks that link is down, but physical link is up. To
reset this state user have to take interface down and up.

If link goes down after 0x0605 command, FW send information
about that and after that driver tells the OS that the link goes
down. So this code in ethtool is unnecessary.
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Currently if a user sets an odd [tx|rx]-usecs value through ethtool,
the request is denied because the hardware is set to have an ITR
granularity of 2us. This caused poor customer experience. Fix this by
aligning to a register allowed value, which results in rounding down.
Also, print a once per ring container type message to be clear about
our intentions.

Also, change the ITR_TO_REG define to be the bitwise and of the ITR
setting and the ICE_ITR_MASK. This makes the purpose of ITR_TO_REG more
obvious.
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

list_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
by default.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The PN544 driver checks the "enable" polarity during of driver's probe and
it's doing that by turning ON and OFF NFC with different polarities until
enabling succeeds. It takes some time for the hardware to power-down, and
thus, to deassert the IRQ that is raised by turning ON the hardware.
Since the delay after last power-down of the polarity-checking process is
missed in the code, the interrupt may trigger immediately after installing
the IRQ handler (right after the checking is done), which results in IRQ
handler trying to touch the disabled HW and ends with marking NFC as
'DEAD' during of the driver's probe:

  pn544_hci_i2c 1-002a: NFC: nfc_en polarity : active high
  pn544_hci_i2c 1-002a: NFC: invalid len byte
  shdlc: llc_shdlc_recv_frame: NULL Frame -> link is dead

This patch fixes the occasional NFC initialization failure on Nexus 7
device.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

node_db is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of hsr->list_lock.

Hence, add corresponding lockdep expression to silence false-positive
warnings, and harden RCU lists.
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
Mellanox, mlx5 fixes 2020-02-18

This series introduces some fixes to mlx5 driver.

Please pull and let me know if there is any problem.

For -stable v5.3
 ('net/mlx5: Fix sleep while atomic in mlx5_eswitch_get_vepa')

For -stable v5.4
 ('net/mlx5: DR, Fix matching on vport gvmi')
 ('net/mlx5e: Fix crash in recovery flow without devlink reporter')

For -stable v5.5
 ('net/mlx5e: Reset RQ doorbell counter before moving RQ state from RST to RDY')
 ('net/mlx5e: Don't clear the whole vf config when switching modes')
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

On flow table creation, send the relevant flags according to what the FW
currently supports.
When FW doesn't support reformat option over SW-steering managed table,
the driver shouldn't pass this.

Fixes: 988fd6b3 ("net/mlx5: DR, Pass table flags at creation to lower layer")
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

The pool sizes represent the pool sizes in the fw. when we request
a pool size from fw, it will return the next possible group.
We track how many pools the fw has left and start requesting groups
from the big to the small.
When we start request 4k group, which doesn't exists in fw, fw
wants to allocate the next possible size, 64k, but will fail since
its exhausted. The correct smallest pool size in fw is 128 and not 4k.

Fixes: 39ac237c ("net/mlx5: E-Switch, Refactor chains and priorities")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

There is no need to reset all vf config (except link state) between
legacy and switchdev modes changes.
Also, set link state to AUTO, when legacy enabled.

Fixes: 3b83b6c2 ("net/mlx5e: Clear VF config when switching modes")
Signed-off-by: Dmytro Linkin <dmitrolin@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Set vport gvmi in the tag, only when source gvmi is set in the bit mask.

Fixes: 26d688e3 ("net/mlx5: DR, Add Steering entry (STE) utilities")
Signed-off-by: Hamdan Igbaria <hamdani@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

When health reporters are not supported, recovery function is invoked
directly, not via devlink health reporters.

In this direct flow, the recover function input parameter was passed
incorrectly and is causing a kernel oops. This patch is fixing the input
parameter.

Following call trace is observed on rx error health reporting.

Internal error: Oops: 96000007 [#1] PREEMPT SMP
Process kworker/u16:4 (pid: 4584, stack limit = 0x00000000c9e45703)
Call trace:
mlx5e_rx_reporter_err_rq_cqe_recover+0x30/0x164 [mlx5_core]
mlx5e_health_report+0x60/0x6c [mlx5_core]
mlx5e_reporter_rq_cqe_err+0x6c/0x90 [mlx5_core]
mlx5e_rq_err_cqe_work+0x20/0x2c [mlx5_core]
process_one_work+0x168/0x3d0
worker_thread+0x58/0x3d0
kthread+0x108/0x134

Fixes: c50de4af ("net/mlx5e: Generalize tx reporter's functionality")
Signed-off-by: Aya Levin <ayal@mellanox.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Initialize RQ doorbell counters to zero prior to moving an RQ from RST
to RDY state. Per HW spec, when RQ is back to RDY state, the descriptor
ID on the completion is reset. The doorbell record must comply.

Fixes: 8276ea13 ("net/mlx5e: Report and recover from CQE with error on RQ")
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reported-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

rtnl_bridge_getlink is protected by rcu lock, so mlx5_eswitch_get_vepa
cannot take mutex lock. Two possible issues can happen:
1. User at the same time change vepa mode via RTM_SETLINK command.
2. User at the same time change the switchdev mode via devlink netlink
interface.

Case 1 cannot happen because rtnl executes one message in order.
Case 2 can happen but we do not expect user to change the switchdev mode
when changing vepa. Even if a user does it, so he will read a value
which is no longer valid.

Fixes: 8da202b2 ("net/mlx5: E-Switch, Add support for VEPA in legacy mode.")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

This batch contains Netfilter fixes for net:

1) Restrict hashlimit size to 1048576, from Cong Wang.

2) Check for offload flags from nf_flow_table_offload_setup(),
   this fixes a crash in case the hardware offload is disabled.
   From Florian Westphal.

3) Three preparation patches to extend the conntrack clash resolution,
   from Florian.

4) Extend clash resolution to deal with DNS packets from the same flow
   racing to set up the NAT configuration.

5) Small documentation fix in pipapo, from Stefano Brivio.

6) Remove misleading unlikely() from pipapo_refill(), also from Stefano.

7) Reduce hashlimit mutex scope, from Cong Wang. This patch is actually
   triggering another problem, still under discussion, another patch to
   fix this will follow up.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

I originally used unlikely() in the if (match_only) clause, which
we hit on the mapping table for the last field in a set, to ensure
we avoid branching to the rest of for loop body, which is executed
more frequently.

However, Pablo reports, this is confusing as it gives the impression
that this is not a common case, and it's actually not the intended
usage of unlikely().

I couldn't observe any statistical difference in matching rates on
x864_64 and aarch64 without it, so just drop it.
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fixes: 3c4287f6 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

In both insertion and lookup examples, the two element pointers
of rule mapping tables were swapped. Fix that.
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fixes: 3c4287f6 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

hlist_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
by default.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hlist_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
by default.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hlist_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
by default.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hlist_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
by default.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

list_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
by default.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

list_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
by default.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit ba27b4cd

Ahmed reported ouf-of-order issues bisected to commit ba27b4cd
("net: dev: introduce support for sch BYPASS for lockless qdisc").
I can't find any working solution other than a plain revert.

This will introduce some minor performance regressions for
pfifo_fast qdisc. I plan to address them in net-next with more
indirect call wrapper boilerplate for qdiscs.
Reported-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Fixes: ba27b4cd ("net: dev: introduce support for sch BYPASS for lockless qdisc")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Dan Carpenter reports static checker warnings due to bogus BIT() usage:

net/mptcp/subflow.c:571 subflow_write_space() warn: test_bit() takes a bit number
net/mptcp/subflow.c:694 subflow_state_change() warn: test_bit() takes a bit number
net/mptcp/protocol.c:261 ssk_check_wmem() warn: test_bit() takes a bit number
[..]

This is harmless (we use bits 1 & 2 instead of 0 and 1), but would
break eventually when adding BIT(5) (or 6, depends on size of 'long').

Just use 0 and 1, the values are only passed to test/set/clear_bit
functions.

Fixes: 648ef4b8 ("mptcp: Implement MPTCP receive path")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

If an event is added while the rdma workqueue is being destroyed
it could lead to several races, list corruption, null pointer
dereference during queue_work or init_queue.
This fixes the race between the two flows which can occur during
shutdown.

A kref object and a completion object are added to the rdma_dev
structure, these are initialized before the workqueue is created.
The refcnt is used to indicate work is being added to the
workqueue and ensures the cleanup flow won't start while we're in
the middle of adding the event.
Once the work is added, the refcnt is decreased and the cleanup flow
is safe to run.

Fixes: cee9fbd8 ("qede: Add qedr framework")
Signed-off-by: Ariel Elior <ariel.elior@marvell.com>
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

0x11 and 0x12 set the ECN bits based on RFC2474, it would be better to avoid
that. 0x14 and 0x18 would be better and works as well.
Reported-by: Petr Machata <petrm@mellanox.com>
Fixes: 4e867c9a ("selftests: forwarding: vxlan_bridge_1d: fix tos value")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The reserved member should be named reserved3.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When T2 timer is to be stopped, the asoc should also be deleted,
otherwise, there will be no chance to call sctp_association_free
and the asoc could last in memory forever.

However, in sctp_sf_shutdown_sent_abort(), after adding the cmd
SCTP_CMD_TIMER_STOP for T2 timer, it may return error due to the
format error from __sctp_sf_do_9_1_abort() and miss adding
SCTP_CMD_ASSOC_FAILED where the asoc will be deleted.

This patch is to fix it by moving the format error check out of
__sctp_sf_do_9_1_abort(), and do it before adding the cmd
SCTP_CMD_TIMER_STOP for T2 timer.

Thanks Hangbin for reporting this issue by the fuzz testing.

v1->v2:
  - improve the comment in the code as Marcelo's suggestion.

Fixes: 96ca468b ("sctp: check invalid value of length parameter in error cause")
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tc flower rules that are based on src or dst port blocking are sometimes
ineffective due to uninitialized stack data. __skb_flow_dissect() extracts
ports from the skb for tc flower to match against. However, the port
dissection is not done when when the FLOW_DIS_IS_FRAGMENT bit is set in
key_control->flags. All callers of __skb_flow_dissect(), zero-out the
key_control field except for fl_classify() as used by the flower
classifier. Thus, the FLOW_DIS_IS_FRAGMENT may be set on entry to
__skb_flow_dissect(), since key_control is allocated on the stack
and may not be initialized.

Since key_basic and key_control are present for all flow keys, let's
make sure they are initialized.

Fixes: 62230715 ("flow_dissector: do not dissect l4 ports for fragments")
Co-developed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Each extracted frame on Ocelot has an IFH. The frame and IFH are extracted
by reading chuncks of 4 bytes from a register.

In case the IFH and frames were read corretly it would try to read the next
frame. In case there are no more frames in the queue, it checks if there
were any previous errors and in that case clear the queue. But this check
will always succeed also when there are no errors. Because when extracting
the IFH the error is checked against 4(number of bytes read) and then the
error is set only if the extraction of the frame failed. So in a happy case
where there are no errors the err variable is still 4. So it could be
a case where after the check that there are no more frames in the queue, a
frame will arrive in the queue but because the error is not reseted, it
would try to flush the queue. So the frame will be lost.

The fix consist in resetting the error after reading the IFH.
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch further relaxes the need to drop an skb due to a clash with
an existing conntrack entry.

Current clash resolution handles the case where the clash occurs between
two identical entries (distinct nf_conn objects with same tuples), i.e.:

                    Original                        Reply
existing: 10.2.3.4:42 -> 10.8.8.8:53      10.2.3.4:42 <- 10.0.0.6:5353
clashing: 10.2.3.4:42 -> 10.8.8.8:53      10.2.3.4:42 <- 10.0.0.6:5353

... existing handling will discard the unconfirmed clashing entry and
makes skb->_nfct point to the existing one.  The skb can then be
processed normally just as if the clash would not have existed in the
first place.

For other clashes, the skb needs to be dropped.
This frequently happens with DNS resolvers that send A and AAAA queries
back-to-back when NAT rules are present that cause packets to get
different DNAT transformations applied, for example:

-m statistics --mode random ... -j DNAT --dnat-to 10.0.0.6:5353
-m statistics --mode random ... -j DNAT --dnat-to 10.0.0.7:5353

In this case the A or AAAA query is dropped which incurs a costly
delay during name resolution.

This patch also allows this collision type:
                       Original                   Reply
existing: 10.2.3.4:42 -> 10.8.8.8:53      10.2.3.4:42 <- 10.0.0.6:5353
clashing: 10.2.3.4:42 -> 10.8.8.8:53      10.2.3.4:42 <- 10.0.0.7:5353

In this case, clash is in original direction -- the reply direction
is still unique.

The change makes it so that when the 2nd colliding packet is received,
the clashing conntrack is tagged with new IPS_NAT_CLASH_BIT, gets a fixed
1 second timeout and is inserted in the reply direction only.

The entry is hidden from 'conntrack -L', it will time out quickly
and it can be early dropped because it will never progress to the
ASSURED state.

To avoid special-casing the delete code path to special case
the ORIGINAL hlist_nulls node, a new helper, "hlist_nulls_add_fake", is
added so hlist_nulls_del() will work.

Example:

      CPU A:                               CPU B:
1.  10.2.3.4:42 -> 10.8.8.8:53 (A)
2.                                         10.2.3.4:42 -> 10.8.8.8:53 (AAAA)
3.  Apply DNAT, reply changed to 10.0.0.6
4.                                         10.2.3.4:42 -> 10.8.8.8:53 (AAAA)
5.                                         Apply DNAT, reply changed to 10.0.0.7
6. confirm/commit to conntrack table, no collisions
7.                                         commit clashing entry

Reply comes in:

10.2.3.4:42 <- 10.0.0.6:5353 (A)
 -> Finds a conntrack, DNAT is reversed & packet forwarded to 10.2.3.4:42
10.2.3.4:42 <- 10.0.0.7:5353 (AAAA)
 -> Finds a conntrack, DNAT is reversed & packet forwarded to 10.2.3.4:42
    The conntrack entry is deleted from table, as it has the NAT_CLASH
    bit set.

In case of a retransmit from ORIGINAL dir, all further packets will get
the DNAT transformation to 10.0.0.6.

I tried to come up with other solutions but they all have worse
problems.

Alternatives considered were:
1.  Confirm ct entries at allocation time, not in postrouting.
 a. will cause uneccesarry work when the skb that creates the
    conntrack is dropped by ruleset.
 b. in case nat is applied, ct entry would need to be moved in
    the table, which requires another spinlock pair to be taken.
 c. breaks the 'unconfirmed entry is private to cpu' assumption:
    we would need to guard all nfct->ext allocation requests with
    ct->lock spinlock.

2. Make the unconfirmed list a hash table instead of a pcpu list.
   Shares drawback c) of the first alternative.

3. Document this is expected and force users to rearrange their
   ruleset (e.g. by using "-m cluster" instead of "-m statistics").
   nft has the 'jhash' expression which can be used instead of 'numgen'.

   Major drawback: doesn't fix what I consider a bug, not very realistic
   and I believe its reasonable to have the existing rulesets to 'just
   work'.

4. Document this is expected and force users to steer problematic
   packets to the same CPU -- this would serialize the "allocate new
   conntrack entry/nat table evaluation/perform nat/confirm entry", so
   no race can occur.  Similar drawback to 3.

Another advantage of this patch compared to 1) and 2) is that there are
no changes to the hot path; things are handled in the udp tracker and
the clash resolution path.

Cc: rcu@vger.kernel.org
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The call to of_get_mac_address() can return -EPROBE_DEFER, for instance
when the MAC address is read from a NVMEM driver that did not probe yet.

Cc: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix all kernel-doc warnings in <linux/skbuff.h>.
Fixes these warnings:

../include/linux/skbuff.h:890: warning: Function parameter or member 'list' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'dev_scratch' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'ip_defrag_offset' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'skb_mstamp_ns' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member '__cloned_offset' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'head_frag' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member '__pkt_type_offset' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'encapsulation' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'encap_hdr_csum' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'csum_valid' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member '__pkt_vlan_present_offset' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'vlan_present' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'csum_complete_sw' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'csum_level' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'inner_protocol_type' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'remcsum_offload' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'sender_cpu' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'reserved_tailroom' not described in 'sk_buff'
../include/linux/skbuff.h:890: warning: Function parameter or member 'inner_ipproto' not described in 'sk_buff'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove stale comments since this flag is no longer a bit mask
but is a bit field.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix all kernel-doc warnings for <net/sock.h>.
Fixes these warnings:

../include/net/sock.h:232: warning: Function parameter or member 'skc_addrpair' not described in 'sock_common'
../include/net/sock.h:232: warning: Function parameter or member 'skc_portpair' not described in 'sock_common'
../include/net/sock.h:232: warning: Function parameter or member 'skc_ipv6only' not described in 'sock_common'
../include/net/sock.h:232: warning: Function parameter or member 'skc_net_refcnt' not described in 'sock_common'
../include/net/sock.h:232: warning: Function parameter or member 'skc_v6_daddr' not described in 'sock_common'
../include/net/sock.h:232: warning: Function parameter or member 'skc_v6_rcv_saddr' not described in 'sock_common'
../include/net/sock.h:232: warning: Function parameter or member 'skc_cookie' not described in 'sock_common'
../include/net/sock.h:232: warning: Function parameter or member 'skc_listener' not described in 'sock_common'
../include/net/sock.h:232: warning: Function parameter or member 'skc_tw_dr' not described in 'sock_common'
../include/net/sock.h:232: warning: Function parameter or member 'skc_rcv_wnd' not described in 'sock_common'
../include/net/sock.h:232: warning: Function parameter or member 'skc_tw_rcv_nxt' not described in 'sock_common'

../include/net/sock.h:498: warning: Function parameter or member 'sk_rx_skb_cache' not described in 'sock'
../include/net/sock.h:498: warning: Function parameter or member 'sk_wq_raw' not described in 'sock'
../include/net/sock.h:498: warning: Function parameter or member 'tcp_rtx_queue' not described in 'sock'
../include/net/sock.h:498: warning: Function parameter or member 'sk_tx_skb_cache' not described in 'sock'
../include/net/sock.h:498: warning: Function parameter or member 'sk_route_forced_caps' not described in 'sock'
../include/net/sock.h:498: warning: Function parameter or member 'sk_txtime_report_errors' not described in 'sock'
../include/net/sock.h:498: warning: Function parameter or member 'sk_validate_xmit_skb' not described in 'sock'
../include/net/sock.h:498: warning: Function parameter or member 'sk_bpf_storage' not described in 'sock'

../include/net/sock.h:2024: warning: No description found for return value of 'sk_wmem_alloc_get'
../include/net/sock.h:2035: warning: No description found for return value of 'sk_rmem_alloc_get'
../include/net/sock.h:2046: warning: No description found for return value of 'sk_has_allocations'
../include/net/sock.h:2082: warning: No description found for return value of 'skwq_has_sleeper'
../include/net/sock.h:2244: warning: No description found for return value of 'sk_page_frag'
../include/net/sock.h:2444: warning: Function parameter or member 'tcp_rx_skb_cache_key' not described in 'DECLARE_STATIC_KEY_FALSE'
../include/net/sock.h:2444: warning: Excess function parameter 'sk' description in 'DECLARE_STATIC_KEY_FALSE'
../include/net/sock.h:2444: warning: Excess function parameter 'skb' description in 'DECLARE_STATIC_KEY_FALSE'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>