cfg80211_chan_def and ieee80211_channel recently gained a
frequency offset component. Handle this where it makes
sense (potentially required by S1G channels).

For IBSS, TDLS, CSA, and ROC we return -EOPNOTSUPP if a
channel with frequency offset is passed, since they may or
may not work. Once someone tests and verifies these
commands work on thos types of channels, we can remove
that error.

join_ocb and join_mesh look harmless because they use a
simple ieee80211_vif_use_channel(), which is using an
already verified channel, so we let those through.
Signed-off-by: NThomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20200402011810.22947-4-thomas@adapt-ip.comSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

Some bands (S1G) define channels centered on a non-integer
MHz. Give ieee80211_channel and cfg80211_chan_def a
freq_offset component where the final frequency can be
expressed as:

MHZ_TO_KHZ(chan->center_freq) + chan->freq_offset;

Also provide some helper functions to do the frequency
conversion and test for equality.

Retain the existing interface to frequency and channel
conversion helpers, and expose new ones which handle
frequencies in units of KHz.

Some internal functions (net/wireless/chan.c) pass around
a frequency value. Convert these to units of KHz.

mesh, ibss, wext, etc. are currently ignored.
Signed-off-by: NThomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20200402011810.22947-3-thomas@adapt-ip.comSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

We know this pointer isn't NULL and in fact dereferenced it before,
remove the redundant test.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.adf551928846.Iae9015573d6c350cc1b12a311d6d13d086beec6c@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

The MLME logic had a workaround that allowed to continue an
association with an AP even if the AP did not provide any basic
rates in its supported rates in the association response, assuming
that the first (non basic) legacy rate could be used as a basic rate.
However, this did not consider the case where the AP (which is
obviously buggy) did not provide any legacy rate.

Fix this by failing the association, as this can result in
an unexpected failure in the low level driver and FW, e.g., in
rate scale logic etc.
Signed-off-by: NIlan Peer <ilan.peer@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.d70a1450d83f.I6e6ce5efda351a8544c0e7bfeee260fe3360d401@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

Driver tells mac80211 to sends ADDBA with SSN (starting sequence number)
from the head of the queue, while the transmission of all the frames in the
queue may take a while, which causes the peer to time out. In order to
fix this scenario, add an option to defer ADDBA transmit until queue
is drained.
Signed-off-by: NMordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.0f27423fec75.If67daab123a27c1cbddef000d6a3f212aa6309ef@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

We move the actual arming the timer and sending ADDBA to a function
for the use in different places calling the same logic.
Signed-off-by: NMordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.58a337eb90a1.I75934e6464535fbf43969acc796bc886291e79a5@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

When parsing supported rates IE.
Signed-off-by: NIlan Peer <ilan.peer@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.ed3e66f8c197.I93aad0e5ddb7ce79f05f8153922acb9aa5076d38@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

This extends the support for drivers that rebuilds IEs in the
FW (same as with HT/VHT).
Signed-off-by: NIlan Peer <ilan.peer@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.20feaabfb484.I886252639604c8e3e84b8ef97962f1b0e4beec81@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

SAE AP may reject authentication with WLAN_STATUS_ANTI_CLOG_REQUIRED.
As the user space will immediately continue the authentication flow,
there is no need to destroy the authentication data in this case.
This saves unneeded station removal and releasing the channel.
Signed-off-by: NAndrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.7483996157a8.I8040a842874aaf6d209df3fc8a2acb97a0bf508b@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

Add a flag to the BSS conf whether the BSS and STA support protected TWT.
Signed-off-by: NShaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.1dcb2d16fa74.I74d7c007dad2601d2e39f54612fe6554dd5ab386@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

Somehow we missed this for a long time, but similar to the extended
NSS support in VHT capabilities, we need to have this in Operating
Mode notification.

Implement it by
 * parsing the 160/80+80 bit there and setting the bandwidth
   appropriately
 * having callers of ieee80211_get_vht_max_nss() pass in the current
   max NSS value as received in the operating mode notification in
   order to modify it appropriately depending on the extended NSS
   bits.

This updates all drivers that use it, i.e. only iwlwifi/mvm.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.098483728cfa.I4e8c25d3288441759c2793247197229f0696a37d@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

Convert a user space registration for processing multicast Action frames
(NL80211_CMD_REGISTER_FRAME with NL80211_ATTR_RECEIVE_MULTICAST) to a
new enum ieee80211_filter_flags bit FIF_MCAST_ACTION so that drivers can
update their RX filter parameters appropriately, if needed.
Signed-off-by: NJouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20200421144815.19175-1-jouni@codeaurora.org
[rename variables to rx_mcast_action_reg indicating action frames only]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The current NL80211_EXT_FEATURE_BEACON_PROTECTION feature flag
requires both AP and client support, add a new one called
NL80211_EXT_FEATURE_BEACON_PROTECTION_CLIENT that enables only
support in client (and P2P-client) modes.

Link: https://lore.kernel.org/r/20200420140559.6ba704053a5a.Ifeb869fb0b48e52fe0cb9c15572b93ac8a924f8d@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

For DPP, there's a need to receive multicast action frames,
but many drivers need a special filter configuration for this.

Support announcing from userspace in the management registration
that multicast RX is required, with an extended feature flag if
the driver handles this.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Reviewed-by: NSergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Link: https://lore.kernel.org/r/20200417124013.c46238801048.Ib041d437ce0bff28a0c6d5dc915f68f1d8591002@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

Almost all drivers below cfg80211 get the API wrong (except for
cfg80211) and are unable to cope with multiple registrations for
the same frame type, which is valid due to the match filter.
This seems to indicate the API is wrong, and we should maintain
the full information in cfg80211 instead of the drivers.

Change the API to no longer inform the driver about individual
registrations and unregistrations, but rather every time about
the entire state of the entire wiphy and single wdev, whenever
it may have changed. This also simplifies the code in cfg80211
as it no longer has to track exactly what was unregistered and
can free things immediately.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Acked-by: NArend van Spriel <arend.vanspriel@broadcom.com>
Reviewed-by: NSergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Link: https://lore.kernel.org/r/20200417124300.f47f3828afc8.I7f81ef59c2c5a340d7075fb3c6d0e08e8aeffe07@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

Report received Beacon frames that do not have a valid MME MIC when
beacon protection is enabled. This covers both the cases of no MME in
the received frame and invalid MIC in the MME.
Signed-off-by: NJouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20200401142548.6990-2-jouni@codeaurora.orgSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

Extend cfg80211_rx_unprot_mlme_mgmt() to cover indication of unprotected
Beacon frames in addition to the previously used Deauthentication and
Disassociation frames. The Beacon frame case is quite similar, but has
couple of exceptions: this is used both with fully unprotected and also
incorrectly protected frames and there is a rate limit on the events to
avoid unnecessary flooding netlink events in case something goes wrong.
Signed-off-by: NJouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20200401142548.6990-1-jouni@codeaurora.org
[add missing kernel-doc]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There are two bugs with this, first, it shouldn't be called
on an interface that's down, and secondly, it should then be
called when the interface comes up.

Note that the currently only user (iwlwifi) doesn't seem to
care about either of these scenarios.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20200417111830.401d82c7a0bf.I5dc7d718816460c2d8d89c7af6c215f9e2b3078f@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

Maintain the connection AID only in sdata->vif.bss_conf.aid, not
also in sdata->u.mgd.aid.

Keep setting that where we set ifmgd->aid before, which has the
side effect of exposing the AID to the driver before the station
entry (AP) is marked associated, in case it needs it then.
Requested-by: NFelix Fietkau <nbd@nbd.name>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Tested-by: NLorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/20200417123802.085d4a322b0c.I2e7a2ceceea8c6880219f9e9ee4d4ac985fd295a@changeidSigned-off-by: NJohannes Berg <johannes.berg@intel.com>

When setting the meter rate to 4+Gbps, there is an
overflow, the meters don't work as expected.

Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Andy Zhou <azhou@ovn.org>
Signed-off-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Andy Zhou <azhou@ovn.org>
Signed-off-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Before invoking the ovs_meter_cmd_reply_stats, "meter"
was checked, so don't check it agin in that function.

Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Andy Zhou <azhou@ovn.org>
Signed-off-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't allow user to create meter unlimitedly, which may cause
to consume a large amount of kernel memory. The max number
supported is decided by physical memory and 20K meters as default.

Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Andy Zhou <azhou@ovn.org>
Signed-off-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In kernel datapath of Open vSwitch, there are only 1024
buckets of meter in one datapath. If installing more than
1024 (e.g. 8192) meters, it may lead to the performance drop.
But in some case, for example, Open vSwitch used as edge
gateway, there should be 20K at least, where meters used for
IP address bandwidth limitation.

[Open vSwitch userspace datapath has this issue too.]

For more scalable meter, this patch use meter array instead of
hash tables, and expand/shrink the array when necessary. So we
can install more meters than before in the datapath.
Introducing the struct *dp_meter_instance, it's easy to
expand meter though changing the *ti point in the struct
*dp_meter_table.

Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Andy Zhou <azhou@ovn.org>
Signed-off-by: NTonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove unnecassary casts in the argument to kfree.
Signed-off-by: NXu Wang <vulab@iscas.ac.cn>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

gro_flush_timeout and napi_defer_hard_irqs can be read
from napi_complete_done() while other cpus write the value,
whithout explicit synchronization.

Use READ_ONCE()/WRITE_ONCE() to annotate the races.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Back in commit 3b47d303 ("net: gro: add a per device gro flush timer")
we added the ability to arm one high resolution timer, that we used
to keep not-complete packets in GRO engine a bit longer, hoping that further
frames might be added to them.

Since then, we added the napi_complete_done() interface, and commit
364b6055 ("net: busy-poll: return busypolling status to drivers")
allowed drivers to avoid re-arming NIC interrupts if we made a promise
that their NAPI poll() handler would be called in the near future.

This infrastructure can be leveraged, thanks to a new device parameter,
which allows to arm the napi hrtimer, instead of re-arming the device
hard IRQ.

We have noticed that on some servers with 32 RX queues or more, the chit-chat
between the NIC and the host caused by IRQ delivery and re-arming could hurt
throughput by ~20% on 100Gbit NIC.

In contrast, hrtimers are using local (percpu) resources and might have lower
cost.

The new tunable, named napi_defer_hard_irqs, is placed in the same hierarchy
than gro_flush_timeout (/sys/class/net/ethX/)

By default, both gro_flush_timeout and napi_defer_hard_irqs are zero.

This patch does not change the prior behavior of gro_flush_timeout
if used alone : NIC hard irqs should be rearmed as before.

One concrete usage can be :

echo 20000 >/sys/class/net/eth1/gro_flush_timeout
echo 10 >/sys/class/net/eth1/napi_defer_hard_irqs

If at least one packet is retired, then we will reset napi counter
to 10 (napi_defer_hard_irqs), ensuring at least 10 periodic scans
of the queue.

On busy queues, this should avoid NIC hard IRQ, while before this patch IRQ
avoidance was only possible if napi->poll() was exhausting its budget
and not call napi_complete_done().

This feature also can be used to work around some non-optimal NIC irq
coalescing strategies.

Having the ability to insert XX usec delays between each napi->poll()
can increase cache efficiency, since we increase batch sizes.

It also keeps serving cpus not idle too long, reducing tail latencies.
Co-developed-by: NLuigi Rizzo <lrizzo@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

gro_cells lib is used by different encapsulating netdevices, such as
geneve, macsec, vxlan etc. to speed up decapsulated traffic processing.
CPU tag is a sort of "encapsulation", and we can use the same mechs to
greatly improve overall DSA performance.
skbs are passed to the GRO layer after removing CPU tags, so we don't
need any new packet offload types as it was firstly proposed by me in
the first GRO-over-DSA variant [1].

The size of struct gro_cells is sizeof(void *), so hot struct
dsa_slave_priv becomes only 4/8 bytes bigger, and all critical fields
remain in one 32-byte cacheline.
The other positive side effect is that drivers for network devices
that can be shipped as CPU ports of DSA-driven switches can now use
napi_gro_frags() to pass skbs to kernel. Packets built that way are
completely non-linear and are likely being dropped without GRO.

This was tested on to-be-mainlined-soon Ethernet driver that uses
napi_gro_frags(), and the overall performance was on par with the
variant from [1], sometimes even better due to minimal overhead.
net.core.gro_normal_batch tuning may help to push it to the limit
on particular setups and platforms.

iperf3 IPoE VLAN NAT TCP forwarding (port1.218 -> port0) setup
on 1.2 GHz MIPS board:

5.7-rc2 baseline:

[ID]  Interval         Transfer     Bitrate        Retr
[ 5]  0.00-120.01 sec  9.00 GBytes  644 Mbits/sec  413  sender
[ 5]  0.00-120.00 sec  8.99 GBytes  644 Mbits/sec       receiver

Iface      RX packets  TX packets
eth0       7097731     7097702
port0      426050      6671829
port1      6671681     425862
port1.218  6671677     425851

With this patch:

[ID]  Interval         Transfer     Bitrate        Retr
[ 5]  0.00-120.01 sec  12.2 GBytes  870 Mbits/sec  122  sender
[ 5]  0.00-120.00 sec  12.2 GBytes  870 Mbits/sec       receiver

Iface      RX packets  TX packets
eth0       9474792     9474777
port0      455200      353288
port1      9019592     455035
port1.218  353144      455024

v2:
 - Add some performance examples in the commit message;
 - No functional changes.

[1] https://lore.kernel.org/netdev/20191230143028.27313-1-alobakin@dlink.ru/Signed-off-by: NAlexander Lobakin <bloodyreaper@yandex.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC4862 5.5.3 e) prevents received Router Advertisements from reducing
the Valid Lifetime of configured addresses to less than two hours, thus
preventing hosts from reacting to the information provided by a router
that has positive knowledge that a prefix has become invalid.

This patch makes hosts honor all Valid Lifetime values, as per
draft-gont-6man-slaac-renum-06, Section 4.2. This is meant to help
mitigate the problem discussed in draft-ietf-v6ops-slaac-renum.

Note: Attacks aiming at disabling an advertised prefix via a Valid
Lifetime of 0 are not really more harmful than other attacks
that can be performed via forged RA messages, such as those
aiming at completely disabling a next-hop router via an RA that
advertises a Router Lifetime of 0, or performing a Denial of
Service (DoS) attack by advertising illegitimate prefixes via
forged PIOs.  In scenarios where RA-based attacks are of concern,
proper mitigations such as RA-Guard [RFC6105] [RFC7113] should
be implemented.
Signed-off-by: NFernando Gont <fgont@si6networks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix the following coccicheck warning:

net/caif/caif_dev.c:410:2-13: WARNING: Assignment of 0/1 to bool
variable
net/caif/caif_dev.c:445:2-13: WARNING: Assignment of 0/1 to bool
variable
net/caif/caif_dev.c:145:1-12: WARNING: Assignment of 0/1 to bool
variable
net/caif/caif_dev.c:223:1-12: WARNING: Assignment of 0/1 to bool
variable
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add tracepoint support for QRTR with NS as the first candidate. Later on
this can be extended to core QRTR and transport drivers.

The trace_printk() used in NS has been replaced by tracepoints.
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/ila/ila_xlat.c:604:0: warning: macro "ILA_HASH_TABLE_SIZE" is not used [-Wunused-macros]
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the act_ct SW offload in flowtable, The counter of the conntrack
entry will never update. So update the nf_conn_acct conuter in act_ct
flowtable software offload.
Signed-off-by: Nwenxu <wenxu@ucloud.cn>
Reviewed-by: NRoi Dayan <roid@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Get rid of linux/vermagic.h includes, so that MODULE_ARCH_VERMAGIC from
the arch header arch/x86/include/asm/module.h won't be redefined.

  In file included from ./include/linux/module.h:30,
                   from drivers/net/ethernet/3com/3c515.c:56:
  ./arch/x86/include/asm/module.h:73: warning: "MODULE_ARCH_VERMAGIC"
redefined
     73 | # define MODULE_ARCH_VERMAGIC MODULE_PROC_FAMILY
        |
  In file included from drivers/net/ethernet/3com/3c515.c:25:
  ./include/linux/vermagic.h:28: note: this is the location of the
previous definition
     28 | #define MODULE_ARCH_VERMAGIC ""
        |

Fixes: 6bba2e89 ("net/3com: Delete driver and module versions from 3com drivers")
Co-developed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: Shannon Nelson <snelson@pensando.io> # ionic
Acked-by: Sebastian Reichel <sre@kernel.org> # power
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The variable rc is being assigned with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an interface is executing a self test, put the interface into
operative status testing.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to speed, duplex and dorment, report the testing status
in sysfs.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC 2863 defines the operational state testing. Add support for this
state, both as a IF_LINK_MODE_ and __LINK_STATE_.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The Enhanced Connection Complete event is use in conjunction with LL
Privacy and not Extended Advertising.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

In commit 16ad3f40 ("tipc: introduce variable window congestion
control"), we allow link window to change with the congestion avoidance
algorithm. However, there is a bug that during the slow-start if packet
retransmission occurs, the link will enter the fast-recovery phase, set
its window to the 'ssthresh' which is never less than 300, so the link
window suddenly increases to that limit instead of decreasing.

Consequently, two issues have been observed:

- For broadcast-link: it can leave a gap between the link queues that a
new packet will be inserted and sent before the previous ones, i.e. not
in-order.

- For unicast: the algorithm does not work as expected, the link window
jumps to the slow-start threshold whereas packet retransmission occurs.

This commit fixes the issues by avoiding such the link window increase,
but still decreasing if the 'ssthresh' is lowered.

Fixes: 16ad3f40 ("tipc: introduce variable window congestion control")
Acked-by: NJon Maloy <jmaloy@redhat.com>
Signed-off-by: NTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>