This helper serves to know if two switchdev port netdevices belong to the
same HW ASIC, e.g to figure out if forwarding offload is possible between them.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit utilize the ability of ConnectX-4 to bulk read flow counters.
Few bulk counter queries could be done instead of issuing thousands of
firmware commands per second to get statistics of all flows set to HW,
such as those programmed when we offload tc filters.

Counters are stored sorted by hardware id, and queried in blocks (id +
number of counters).

Due to hardware requirement, start of block and number of counters in a
block must be four aligned.
Reviewed-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NAmir Vadai <amir@vadai.me>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to use bulk counters, we need to have counters sorted by id.
Signed-off-by: NAmir Vadai <amir@vadai.me>
Reviewed-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Identifying address family operations during rx path is not something
expensive but it's ugly to the eye to have it done multiple times,
specially when we already validated it during initial rx processing.

This patch takes advantage of the now shared sctp_input_cb and make the
pointer to the operations readily available.
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SCTP will try to access original IP headers on sctp_recvmsg in order to
copy the addresses used. There are also other places that do similar access
to IP or even SCTP headers. But after 90017acc ("sctp: Add GSO
support") they aren't always there because they are only present in the
header skb.

SCTP handles the queueing of incoming data by cloning the incoming skb
and limiting to only the relevant payload. This clone has its cb updated
to something different and it's then queued on socket rx queue. Thus we
need to fix this in two moments.

For rx path, not related to socket queue yet, this patch uses a
partially copied sctp_input_cb to such GSO frags. This restores the
ability to access the headers for this part of the code.

Regarding the socket rx queue, it removes iif member from sctp_event and
also add a chunk pointer on it.

With these changes we're always able to reach the headers again.

The biggest change here is that now the sctp_chunk struct and the
original skb are only freed after the application consumed the buffer.
Note however that the original payload was already like this due to the
skb cloning.

For iif, SCTP's IPv4 code doesn't use it, so no change is necessary.
IPv6 now can fetch it directly from original's IPv6 CB as the original
skb is still accessible.

In the future we probably can simplify sctp_v*_skb_iif() stuff, as
sctp_v4_skb_iif() was called but it's return value not used, and now
it's not even called, but such cleanup is out of scope for this change.

Fixes: 90017acc ("sctp: Add GSO support")
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The next patch needs 8 bytes in there. sctp_ulpevent has a hole due to
bad alignment; msg_flags is using 4 bytes while it actually uses only 2, so
we shrink it, and iif member (4 bytes) which can be easily fetched from
another place once the next patch is there, so we remove it and thus
creating space for 8 bytes.
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We process input path in other files too and having access to it is
nice, so move it to a header where it's shared.
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If link is disconnected due to Authentication Failure (PIN or Key
Missing status) userspace will be notified about this with proper error
code. Many LE profiles define "PIN or Key Missing" status as indication
of remote lost bond so this allows userspace to take action on this.

@ Device Connected: 88:63:DF:88:0E:83 (1) flags 0x0000
        02 01 1a 05 03 0a 18 0d 18 0b 09 48 65 61 72 74  ...........Heart
        20 52 61 74 65                                    Rate
> HCI Event: Command Status (0x0f) plen 4
      LE Read Remote Used Features (0x08|0x0016) ncmd 1
        Status: Success (0x00)
> ACL Data RX: Handle 3585 flags 0x02 dlen 11
      ATT: Read By Group Type Request (0x10) len 6
        Handle range: 0x0001-0xffff
        Attribute group type: Primary Service (0x2800)
> HCI Event: LE Meta Event (0x3e) plen 12
      LE Read Remote Used Features (0x04)
        Status: Success (0x00)
        Handle: 3585
        Features: 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00
          LE Encryption
< HCI Command: LE Start Encryption (0x08|0x0019) plen 28
        Handle: 3585
        Random number: 0x0000000000000000
        Encrypted diversifier: 0x0000
        Long term key: 26201cd479a0921b6f949f0b1fa8dc82
> HCI Event: Command Status (0x0f) plen 4
      LE Start Encryption (0x08|0x0019) ncmd 1
        Status: Success (0x00)
> HCI Event: Encryption Change (0x08) plen 4
        Status: PIN or Key Missing (0x06)
        Handle: 3585
        Encryption: Disabled (0x00)
< HCI Command: Disconnect (0x01|0x0006) plen 3
        Handle: 3585
        Reason: Authentication Failure (0x05)
> HCI Event: Command Status (0x0f) plen 4
      Disconnect (0x01|0x0006) ncmd 1
        Status: Success (0x00)
> HCI Event: Disconnect Complete (0x05) plen 4
        Status: Success (0x00)
        Handle: 3585
        Reason: Connection Terminated By Local Host (0x16)
@ Device Disconnected: 88:63:DF:88:0E:83 (1) reason 4

@ Device Connected: C4:43:8F:A3:4D:83 (0) flags 0x0000
        08 09 4e 65 78 75 73 20 35                       ..Nexus 5
> HCI Event: Command Status (0x0f) plen 4
      Authentication Requested (0x01|0x0011) ncmd 1
        Status: Success (0x00)
> HCI Event: Link Key Request (0x17) plen 6
        Address: C4:43:8F:A3:4D:83 (LG Electronics)
< HCI Command: Link Key Request Reply (0x01|0x000b) plen 22
        Address: C4:43:8F:A3:4D:83 (LG Electronics)
        Link key: 080812e4aa97a863d11826f71f65a933
> HCI Event: Command Complete (0x0e) plen 10
      Link Key Request Reply (0x01|0x000b) ncmd 1
        Status: Success (0x00)
        Address: C4:43:8F:A3:4D:83 (LG Electronics)
> HCI Event: Auth Complete (0x06) plen 3
        Status: PIN or Key Missing (0x06)
        Handle: 75
@ Authentication Failed: C4:43:8F:A3:4D:83 (0) status 0x05
< HCI Command: Disconnect (0x01|0x0006) plen 3
        Handle: 75
        Reason: Remote User Terminated Connection (0x13)
> HCI Event: Command Status (0x0f) plen 4
      Disconnect (0x01|0x0006) ncmd 1
        Status: Success (0x00)
> HCI Event: Disconnect Complete (0x05) plen 4
        Status: Success (0x00)
        Handle: 75
        Reason: Connection Terminated By Local Host (0x16)
@ Device Disconnected: C4:43:8F:A3:4D:83 (0) reason 4
Signed-off-by: NSzymon Janc <szymon.janc@codecoup.pl>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

Define a tracepoint and allow user to trace messages going to and from
hardware associated with devlink instance.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

prsctp PRIO policy is a policy to abandon lower priority chunks when
asoc doesn't have enough snd buffer, so that the current chunk with
higher priority can be queued successfully.

Similar to TTL/RTX policy, we will set the priority of the chunk to
prsctp_param with sinfo->sinfo_timetolive in sctp_set_prsctp_policy().
So if PRIO policy is enabled, msg->expire_at won't work.

asoc->sent_cnt_removable will record how many chunks can be checked to
remove. If priority policy is enabled, when the chunk is queued into
the out_queue, we will increase sent_cnt_removable. When the chunk is
moved to abandon_queue or dequeue and free, we will decrease
sent_cnt_removable.

In sctp_sendmsg, we will check if there is enough snd buffer for current
msg and if sent_cnt_removable is not 0. Then try to abandon chunks in
sctp_prune_prsctp when sendmsg from the retransmit/transmited queue, and
free chunks from out_queue in right order until the abandon+free size >
msg_len - sctp_wfree. For the abandon size, we have to wait until it
sends FORWARD TSN, receives the sack and the chunks are really freed.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

prsctp TTL policy is a policy to abandon chunks when they expire
at the specific time in local stack. It's similar with expires_at
in struct sctp_datamsg.

This patch uses sinfo->sinfo_timetolive to set the specific time for
TTL policy. sinfo->sinfo_timetolive is also used for msg->expires_at.
So if prsctp_enable or TTL policy is not enabled, msg->expires_at
still works as before.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds SCTP_PR_ASSOC_STATUS to sctp sockopt, which is used
to dump the prsctp statistics info from the asoc. The prsctp statistics
includes abandoned_sent/unsent from the asoc. abandoned_sent is the
count of the packets we drop packets from retransmit/transmited queue,
and abandoned_unsent is the count of the packets we drop from out_queue
according to the policy.

Note: another option for prsctp statistics dump described in rfc is
SCTP_PR_STREAM_STATUS, which is used to dump the prsctp statistics
info from each stream. But by now, linux doesn't yet have per stream
statistics info, it needs rfc6525 to be implemented. As the prsctp
statistics for each stream has to be based on per stream statistics,
we will delay it until rfc6525 is done in linux.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds SCTP_DEFAULT_PRINFO to sctp sockopt. It is used
to set/get sctp Partially Reliable Policies' default params,
which includes 3 policies (ttl, rtx, prio) and their values.

Still, if we set policy params in sndinfo, we will use the params
of sndinfo against chunks, instead of the default params.

In this patch, we will use 5-8bit of sp/asoc->default_flags
to store prsctp policies, and reuse asoc->default_timetolive
to store their values. It means if we enable and set prsctp
policy, prior ttl timeout in sctp will not work any more.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

According to section 4.5 of rfc7496, prsctp_enable should be per asoc.
We will add prsctp_enable to both asoc and ep, and replace the places
where it used net.sctp->prsctp_enable with asoc->prsctp_enable.

ep->prsctp_enable will be initialized with net.sctp->prsctp_enable, and
asoc->prsctp_enable will be initialized with ep->prsctp_enable. We can
also modify it's value through sockopt SCTP_PR_SUPPORTED.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

An important information for the napi_poll tracepoint is knowing
the work done (packets processed) by the napi_poll() call. Add
both the work done and budget, as they are related.

Handle trace_napi_poll() param change in dropwatch/drop_monitor
and in python perf script netdev-times.py in backward compat way,
as python fortunately supports optional parameter handling.
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As was suggested this patch adds support for the different versions of MLD
and IGMP query types. Since the user visible structure is still in net-next
we can augment it instead of adding netlink attributes.
The distinction between the different IGMP/MLD query types is done as
suggested in Section 7.1, RFC 3376 [1] and Section 8.1, RFC 3810 [2] based
on query payload size and code for IGMP. Since all IGMP packets go through
multicast_rcv() and it uses ip_mc_check_igmp/ipv6_mc_check_mld we can be
sure that at least the ip/ipv6 header can be directly used.

[1] https://tools.ietf.org/html/rfc3376#section-7
[2] https://tools.ietf.org/html/rfc3810#section-8.1Suggested-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The HCI_BREDR naming is confusing since it actually stands for Primary
Bluetooth Controller. Which is a term that has been used in the latest
standard. However from a legacy point of view there only really have
been Basic Rate (BR) and Enhanced Data Rate (EDR). Recent versions of
Bluetooth introduced Low Energy (LE) and made this terminology a little
bit confused since Dual Mode Controllers include BR/EDR and LE. To
simplify this the name HCI_PRIMARY stands for the Primary Controller
which can be a single mode or dual mode controller.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

over time there were multiple requests to access different data
structures and fields of task_struct current, so finally add
the helper to access 'current' as-is. Tracing bpf programs will do
the rest of walking the pointers via bpf_probe_read().
Note that current can be null and bpf program has to deal it with,
but even dumb passing null into bpf_probe_read() is still safe.
Suggested-by: NBrendan Gregg <brendan.d.gregg@gmail.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The routing table of every switch in a tree is currently initialized to
all zeros. This is an issue since 0 is a valid port number.

Add a DSA_RTABLE_NONE=-1 constant to initialize the signed values of the
routing table pointing to other switches.

This fixes the device mapping of the mv88e6xxx driver where the port
pointing to the switch itself and to non-existent switches was wrongly
configured to be 0. It is now set to the expected 0xf value.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch cleanups the WARN_ON which occurs when the sk buffer has
insufficient buffer space by moving the WARN_ON into if condition.
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch fixes ieee802154_get_fc_from_skb function on big endian
machines. The function get_unaligned_le16 converts the byte order to
host byte order but we want to keep the byte order like in mac header.
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The RIOT-OS stack does send intra-pan frames but don't set the intra pan
flag inside the mac header. It seems this is valid frame addressing but
inefficient. Anyway this patch adds a new function for intra pan
addressing, doesn't matter if intra pan flag or source and destination
are the same. The newly introduction function will be used to check on
intra pan addressing for 6lowpan.
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds ieee802154_skb_src_pan function to get the pointer
address of the source pan id at skb mac pointer.
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds ieee802154_skb_dst_pan function to get the pointer
address of the destination pan id at skb mac pointer.
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch adds netns support for 802.15.4 subsystem. Most parts are
copy&pasted from wireless subsystem, it has the identically userspace
API.

Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The PAD define should be above the experimental support. We don't care
about if we break userspace in experimental stuff but PAD is part of the
existing UAPI.

Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Stefan Schmidt<stefan@osg.samsung.com>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Previously, mesh power management functionality works only with kernel
MPM. Because user space MPM did not report mesh peer AID to kernel,
the kernel could not identify the bit in TIM element. So this patch
adds mesh peer AID setting API.
Signed-off-by: NMasashi Honma <masashi.honma@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add the following to support beacon report radio measurement
with the measurement mode field set to passive or active:
1. Propagate the required scan duration to the device
2. Report the scan start time (in terms of TSF)
3. Report each BSS's detection time (also in terms of TSF)

TSF times refer to the BSS that the interface that requested the
scan is connected to.
Signed-off-by: NAssaf Krauss <assaf.krauss@intel.com>
Signed-off-by: NAvraham Stern <avraham.stern@intel.com>
[changed ath9k/10k, at76c59x-usb, iwlegacy, wl1251 and wlcore to match
the new API]
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Beacon report radio measurement requires reporting observed BSSs
on the channels specified in the beacon request. If the measurement
mode is set to passive or active, it requires actually performing a
scan (passive or active, accordingly), and reporting the time that
the scan was started and the time each beacon/probe was received
(both in terms of TSF of the BSS of the requesting AP). If the
request mode is table, this information is optional.
In addition, the radio measurement request specifies the channel
dwell time for the measurement.

In order to use scan for beacon report when the mode is active or
passive, add a parameter to scan request that specifies the
channel dwell time, and add scan start time and beacon received time
to scan results information.

Supporting beacon report is required for Multi Band Operation (MBO).
Signed-off-by: NAssaf Krauss <assaf.krauss@intel.com>
Signed-off-by: NDavid Spinadel <david.spinadel@intel.com>
Signed-off-by: NAvraham Stern <avraham.stern@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

add API to support VHT MU-MIMO air sniffer.
in MU-MIMO there are parallel frames on the air while the HW
has only one RX.
add the capability to sniff one of the MU-MIMO parallel frames by
giving the sniffer additional information so it'll know which
of the parallel frames it shall follow.

Add attribute - NL80211_ATTR_MU_MIMO_GROUP_DATA - for getting
a MU-MIMO groupID in order to monitor packets from that group
using VHT MU-MIMO.
And add attribute -NL80211_ATTR_MU_MIMO_FOLLOW_ADDR - for passing
MAC address to monitor mode.
that option will be used by VHT MU-MIMO air sniffer to follow a
station according to it's MAC address using VHT MU-MIMO.
Signed-off-by: NAviya Erenfeld <aviya.erenfeld@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Data structures that are used both with and without RCU protection
are difficult to write in a sparse-clean manner.  If you mark the
relevant pointers with __rcu, sparse will complain about all non-RCU
uses, but if you don't mark those pointers, sparse will complain about
all RCU uses.

This commit therefore suppresses sparse warnings for rcu_dereference_raw(),
allowing mixed-protection data structures to avoid these warnings.
Reported-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Implement an RCU-safe variant of rb_replace_node() and rearrange
rb_replace_node() to do things in the same order.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>

When the data plane is offloaded the traffic doesn't go through the
networking stack. Therefore, after first resolving a neighbour the NUD
state machine will transition it from REACHABLE to STALE until it's
finally deleted by the garbage collector.

To prevent such situations the offloading driver should notify the NUD
state machine on any neighbours that were recently used. The driver's
polling interval should be set so that the NUD state machine can
function as if the traffic wasn't offloaded.

Currently, there are no in-tree drivers that can report confirmation for
a neighbour, but only 'used' indication. Therefore, the polling interval
should be set according to DELAY_FIRST_PROBE_TIME, as a neighbour will
transition from REACHABLE state to DELAY (instead of STALE) if "a packet
was sent within the last DELAY_FIRST_PROBE_TIME seconds" (RFC 4861).

Send a netevent whenever the DELAY_FIRST_PROBE_TIME changes - either via
netlink or sysctl - so that offloading drivers can correctly set their
polling interval.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

L2 upper device needs to propagate neigh_construct/destroy calls down to
lower devices. Do this by defining default ndo functions and use them in
team, bond, bridge and vlan.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As the following patch will allow upper devices to follow the call down
lower devices, we need to add dev here and not rely on n->dev.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement etrhtool set_rxnfc callback to support ethtool flow spec
direct steering. This patch adds only the support of ether flow type
spec. L3/L4 flow specs support will be added in downstream patches.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of having all steering private name spaces and
steering module fields flat in mlx5_core_priv, we wrap
them in mlx5_flow_steering for better modularity and
API exposure.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reduce the set of arguments passed to mlx5_add_flow_rule
by introducing flow_spec structure.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add functions that iterate over lower devices and find port device.
As a dependency add netdev_for_each_all_lower_dev and
netdev_for_each_all_lower_dev_rcu macro with
netdev_all_lower_get_next and netdev_all_lower_get_next_rcu shelpers.

Also, add functions to return mlxsw struct according to lower device
found and mlxsw_port struct with a reference to lower device.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If skb_clear_hash() was invoked due to mangling of relevant headers and
BPF program needs skb->hash later on, we can add a helper to trigger hash
recalculation via bpf_get_hash_recalc().

The helper will return the newly retrieved hash directly, but later access
can also be done via skb context again through skb->hash directly (inline)
without needing to call the helper once more.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>