Since the PNs of all the tx keys are now tracked in the public
part of the key struct (with atomic counter), we no longer
need these functions.

dvm and vt665{5,6} are currently the only users of these functions,
so update them accordingly.
Signed-off-by: NEliad Peller <eliadx.peller@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Some drivers/devices might want to set the IVs by
themselves (and still let mac80211 generate MMIC).

Specifically, this is needed when the device does
offloading at certain times, and the driver has
to make sure that the IVs of new tx frames (from
the host) are synchronized with IVs that were
potentially used during the offloading.

Similarly to CCMP, move the TX IVs of TKIP keys to the
public part of the key struct, and export a function
to add the IV right into the crypto header.

The public tx_pn field is defined as atomic64, so define
TKIP_PN_TO_IV16/32 helper macros to convert it to iv16/32
when needed.

Since the iv32 used for the p1k cache is taken
directly from the frame, we can safely remove
iv16/32 from being protected by tkip.txlock.
Signed-off-by: NEliad Peller <eliadx.peller@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

PBSS (Personal Basic Service Set) is a new BSS type for DMG
networks. It is similar to infrastructure BSS, having an AP-like
entity called PCP (PBSS Control Point), but it has few differences.
PBSS support is mandatory for 11ad devices.

Add support for PBSS by introducing a new PBSS flag attribute.
The PBSS flag is used in the START_AP command to request starting
a PCP instead of an AP, and in the CONNECT command to request
connecting to a PCP instead of an AP.
Signed-off-by: NLior David <liord@codeaurora.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If any frames are dropped that are part of a BA session, the reorder
buffer will "indefinitely" (until the timeout) wait for them to come
in (or a BAR moving the window) and won't release frames after them.
This means it isn't possible to filter frames within a BA session in
firmware.

Introduce an API function that allows such filtering. Calling this
function will move the BA window forward to the new SSN, and allows
marking frames after the SSN as having been filtered, so any future
reordering activity will release frames while skipping the holes.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This will allow drivers to make more educated
decisions whether to defer transmission or not.

Relying on wake_tx_queue() call count implicitly
was not possible because it could be called
without queued frame count actually changing on
software tx aggregation start/stop code paths.

It was also not possible to know how long
byte-wise queue was without dequeueing.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Drivers/devices without their own rate control algorithm can get the
information what rates they should use from either the radiotap header of
injected frames or from the rate control algorithm. But the parsing of the
legacy rate information from the radiotap header was removed in commit
e6a9854b ("mac80211/drivers: rewrite the rate control API").

The removal of this feature heavily reduced the usefulness of frame
injection when wanting to simulate specific transmission behavior. Having
rate parsing together with MCS rates and retry support allows a fine
grained selection of the tx behavior of injected frames for these kind of
tests.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The timestamp given by iwlwifi is at the beginning of the
frame over the air, at (or during) the SYNC field. Allow
such timestamps to be given to mac80211, at least (for now)
for frames with non-HT/VHT preambles.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add a note to userspace on the effect of RFKILL_OP_CHANGE_ALL also
updating the default state for hotplugged devices.
Signed-off-by: NJoão Paulo Rechi Vita <jprvita@endlessm.com>
[reword a bit]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When suspended while polling is paused, polling will erroneously
resume at resume time. Fix this by tracking pause and suspend in
separate state variable and adding the necessary checks.

Clarify the documentation on this as well.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Make the addr parameter const in SET_IEEE80211_PERM_ADDR() to save
clients from having to cast away a const qualifier.
Signed-off-by: NBjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In VHT, the specification allows to limit the number of
MSDUs in an A-MSDU in the Extended Capabilities IE. There
is also a limitation on the byte size in the VHT IE.
In HT, the only limitation is on the byte size.
Parse the capabilities from the peer and make them
available to the driver.

In HT, there is another limitation when a BA agreement
is active: the byte size can't be greater than 4095.
This is not enforced here.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Some drivers offload some frames internally (e.g.
AddBa). Reporting such frames to mac80211 would
only confuse MLME. However it would be useful to
be able to pass such frames to monitor interfaces
for sniffing purposes, e.g. when running AP +
monitor.

To do that allow drivers to tell mac80211 whether
a given frame should be:
 - processed but not delivered to any monitor vif
 - not processed but delievered to monitor vifs
   only
Signed-off-by: NGrzegorz Bajorski <grzegorz.bajorski@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Enable driver to manage the reordering logic itself.
This is needed for example for the iwlwifi driver that
will support hardware assisted reordering.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Currently mac80211 does not inform the driver of the session
block ack timeout when starting a rx aggregation session.
Drivers that manage the reorder buffer need to know this
parameter.
Seeing that there are now too many arguments for the
drv_ampdu_action() function, wrap them inside a structure.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

It's not always necessary to set the status.freq field, for example
when this would be an expensive calculation. It must be set for all
management frames (as they might be reported to userspace), but for
data frames it's not really required. Document this.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Currently mac80211 does not inform the driver of the window
size when starting an RX aggregation session.
To enable managing the reorder buffer in the driver or hardware
the window size is needed.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add an option for driver to check for packet duplication
by itself.
This is needed for example by the iwlwifi driver which
parallelizes the RX path and does the duplication check
per queue.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The Group ID Management frame is an Action frame of
category VHT. It is transmitted by the AP to assign
or change the user position of a STA for one or more
group IDs.
Process and save the group membership data. Notify
underlying driver of changes.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Obviously need to 'or in NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM.

Fixes: c8cd0989 ("net: Eliminate NETIF_F_GEN_CSUM and NETIF_F_V[46]_CSUM")
Reported-by: NJack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adding flow steering support by creating a flow-table per
priority (if rules exist in the priority). mlx5_ib uses
autogrouping and thus only creates the required destinations.

Also includes adding of these flow steering utilities

1. Parsing verbs flow attributes hardware steering specs.

2. Check if flow is multicast - this is required in order to decide
to which flow table will we add the steering rule.

3. Set outer headers in flow match criteria to zeros.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NMoni Shoua <monis@mellanox.com>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change the mlx5 firmware interface header to make it
more clear which bytes should be used by IPv4 or
IPv6 addresses.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NMoni Shoua <monis@mellanox.com>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the driver is loaded, we create flow steering namespace
for kernel bypass with nine priorities and another namespace
for leftovers(in order to catch packets that weren't matched).
Verbs applications will use these priorities.
we found nine as a number that balances the requirements from the
user and retains performance.

The bypass namespace is used by verbs applications that want to bypass
the kernel networking stack. The leftovers namespace is used by verbs
applications and the sniffer in order to catch packets that weren't
handled by any preceding rules.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NMoni Shoua <monis@mellanox.com>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce the modify flow table command. This command is used when
we want to change the next flow table of an existing flow table.
The next flow table is defined as the table we search (in order
to find a match), if we couldn't find a match in any of the flow table
entries in the current flow table.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NMoni Shoua <monis@mellanox.com>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The root Flow Table for each Flow Table Type is defined,
by default, as the Flow Table with level 0.

In order not to use an empty flow tables and introduce new hops,
but still preserve space for flow-tables that have a priority
greater(lower number) than the current flow table, we introduce this
new set root flow table command.
This command tells the HW to start matching packets from the
assigned root flow table.
This command is used when we create new flow table with level lower than the
current lowest flow table or it is the first flow table.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NMoni Shoua <monis@mellanox.com>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When user add rule to autogrouped flow table, we search
for flow group with the same match criteria, if we don't
find such group then we create new flow group with the
required match criteria and insert the rule to this group.

We divide the flow table into required_groups + 1,
in order to reserve a part of the flow table for rules
which don't match any existing group.
Signed-off-by: NMaor Gottlieb <maorg@mellanox.com>
Signed-off-by: NMoni Shoua <monis@mellanox.com>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After IPv6 support has recently been added to metadata dst and related
encaps, add support for populating/reading it from an eBPF program.

Commit d3aa45ce ("bpf: add helpers to access tunnel metadata") started
with initial IPv4-only support back then (due to IPv6 metadata support
not being available yet).

To stay compatible with older programs, we need to test for the passed
structure size. Also TOS and TTL support from the ip_tunnel_info key has
been added. Tested with vxlan devs in collect meta data mode with IPv4,
IPv6 and in compat mode over different network namespaces.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Export flags used by eBPF helper functions through UAPI, so they can be
used by programs (instead of them redefining all flags each time or just
using the hard-coded values). It also gives a better overview what flags
are used where and we can further get rid of the extra macros defined in
filter.c. Moreover, reject invalid flags.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is possible for a process to allocate and accumulate far more FDs than
the process' limit by sending them over a unix socket then closing them
to keep the process' fd count low.

This change addresses this problem by keeping track of the number of FDs
in flight per user and preventing non-privileged processes from having
more FDs in flight than their configured FD limit.

Reported-by: socketpair@gmail.com
Reported-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Mitigates: CVE-2013-4312 (Linux 2.0+)
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NWilly Tarreau <w@1wt.eu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This work adds a generalization of the ingress qdisc as a qdisc holding
only classifiers. The clsact qdisc works on ingress, but also on egress.
In both cases, it's execution happens without taking the qdisc lock, and
the main difference for the egress part compared to prior version of [1]
is that this can be applied with _any_ underlying real egress qdisc (also
classless ones).

Besides solving the use-case of [1], that is, allowing for more programmability
on assigning skb->priority for the mqprio case that is supported by most
popular 10G+ NICs, it also opens up a lot more flexibility for other tc
applications. The main work on classification can already be done at clsact
egress time if the use-case allows and state stored for later retrieval
f.e. again in skb->priority with major/minors (which is checked by most
classful qdiscs before consulting tc_classify()) and/or in other skb fields
like skb->tc_index for some light-weight post-processing to get to the
eventual classid in case of a classful qdisc. Another use case is that
the clsact egress part allows to have a central egress counterpart to
the ingress classifiers, so that classifiers can easily share state (e.g.
in cls_bpf via eBPF maps) for ingress and egress.

Currently, default setups like mq + pfifo_fast would require for this to
use, for example, prio qdisc instead (to get a tc_classify() run) and to
duplicate the egress classifier for each queue. With clsact, it allows
for leaving the setup as is, it can additionally assign skb->priority to
put the skb in one of pfifo_fast's bands and it can share state with maps.
Moreover, we can access the skb's dst entry (f.e. to retrieve tclassid)
w/o the need to perform a skb_dst_force() to hold on to it any longer. In
lwt case, we can also use this facility to setup dst metadata via cls_bpf
(bpf_skb_set_tunnel_key()) without needing a real egress qdisc just for
that (case of IFF_NO_QUEUE devices, for example).

The realization can be done without any changes to the scheduler core
framework. All it takes is that we have two a-priori defined minors/child
classes, where we can mux between ingress and egress classifier list
(dev->ingress_cl_list and dev->egress_cl_list, latter stored close to
dev->_tx to avoid extra cacheline miss for moderate loads). The egress
part is a bit similar modelled to handle_ing() and patched to a noop in
case the functionality is not used. Both handlers are now called
sch_handle_ingress() and sch_handle_egress(), code sharing among the two
doesn't seem practical as there are various minor differences in both
paths, so that making them conditional in a single handler would rather
slow things down.

Full compatibility to ingress qdisc is provided as well. Since both
piggyback on TC_H_CLSACT, only one of them (ingress/clsact) can exist
per netdevice, and thus ingress qdisc specific behaviour can be retained
for user space. This means, either a user does 'tc qdisc add dev foo ingress'
and configures ingress qdisc as usual, or the 'tc qdisc add dev foo clsact'
alternative, where both, ingress and egress classifier can be configured
as in the below example. ingress qdisc supports attaching classifier to any
minor number whereas clsact has two fixed minors for muxing between the
lists, therefore to not break user space setups, they are better done as
two separate qdiscs.

I decided to extend the sch_ingress module with clsact functionality so
that commonly used code can be reused, the module is being aliased with
sch_clsact so that it can be auto-loaded properly. Alternative would have been
to add a flag when initializing ingress to alter its behaviour plus aliasing
to a different name (as it's more than just ingress). However, the first would
end up, based on the flag, choosing the new/old behaviour by calling different
function implementations to handle each anyway, the latter would require to
register ingress qdisc once again under different alias. So, this really begs
to provide a minimal, cleaner approach to have Qdisc_ops and Qdisc_class_ops
by its own that share callbacks used by both.

Example, adding qdisc:

   # tc qdisc add dev foo clsact
   # tc qdisc show dev foo
   qdisc mq 0: root
   qdisc pfifo_fast 0: parent :1 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
   qdisc pfifo_fast 0: parent :2 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
   qdisc pfifo_fast 0: parent :3 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
   qdisc pfifo_fast 0: parent :4 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
   qdisc clsact ffff: parent ffff:fff1

Adding filters (deleting, etc works analogous by specifying ingress/egress):

   # tc filter add dev foo ingress bpf da obj bar.o sec ingress
   # tc filter add dev foo egress  bpf da obj bar.o sec egress
   # tc filter show dev foo ingress
   filter protocol all pref 49152 bpf
   filter protocol all pref 49152 bpf handle 0x1 bar.o:[ingress] direct-action
   # tc filter show dev foo egress
   filter protocol all pref 49152 bpf
   filter protocol all pref 49152 bpf handle 0x1 bar.o:[egress] direct-action

A 'tc filter show dev foo' or 'tc filter show dev foo parent ffff:' will
show an empty list for clsact. Either using the parent names (ingress/egress)
or specifying the full major/minor will then show the related filter lists.

Prior work on a mqprio prequeue() facility [1] was done mainly by John Fastabend.

  [1] http://patchwork.ozlabs.org/patch/512949/Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a small helper skb_postpush_rcsum() and fix up redirect locations
that need CHECKSUM_COMPLETE fixups on ingress. dev_forward_skb() expects
a proper csum that covers also Ethernet header, f.e. since 2c26d34b
("net/core: Handle csum for CHECKSUM_COMPLETE VXLAN forwarding"), we
also do skb_postpull_rcsum() after pulling Ethernet header off via
eth_type_trans().

When using eBPF in a netns setup f.e. with vxlan in collect metadata mode,
I can trigger the following csum issue with an IPv6 setup:

  [  505.144065] dummy1: hw csum failure
  [...]
  [  505.144108] Call Trace:
  [  505.144112]  <IRQ>  [<ffffffff81372f08>] dump_stack+0x44/0x5c
  [  505.144134]  [<ffffffff81607cea>] netdev_rx_csum_fault+0x3a/0x40
  [  505.144142]  [<ffffffff815fee3f>] __skb_checksum_complete+0xcf/0xe0
  [  505.144149]  [<ffffffff816f0902>] nf_ip6_checksum+0xb2/0x120
  [  505.144161]  [<ffffffffa08c0e0e>] icmpv6_error+0x17e/0x328 [nf_conntrack_ipv6]
  [  505.144170]  [<ffffffffa0898eca>] ? ip6t_do_table+0x2fa/0x645 [ip6_tables]
  [  505.144177]  [<ffffffffa08c0725>] ? ipv6_get_l4proto+0x65/0xd0 [nf_conntrack_ipv6]
  [  505.144189]  [<ffffffffa06c9a12>] nf_conntrack_in+0xc2/0x5a0 [nf_conntrack]
  [  505.144196]  [<ffffffffa08c039c>] ipv6_conntrack_in+0x1c/0x20 [nf_conntrack_ipv6]
  [  505.144204]  [<ffffffff8164385d>] nf_iterate+0x5d/0x70
  [  505.144210]  [<ffffffff816438d6>] nf_hook_slow+0x66/0xc0
  [  505.144218]  [<ffffffff816bd302>] ipv6_rcv+0x3f2/0x4f0
  [  505.144225]  [<ffffffff816bca40>] ? ip6_make_skb+0x1b0/0x1b0
  [  505.144232]  [<ffffffff8160b77b>] __netif_receive_skb_core+0x36b/0x9a0
  [  505.144239]  [<ffffffff8160bdc8>] ? __netif_receive_skb+0x18/0x60
  [  505.144245]  [<ffffffff8160bdc8>] __netif_receive_skb+0x18/0x60
  [  505.144252]  [<ffffffff8160ccff>] process_backlog+0x9f/0x140
  [  505.144259]  [<ffffffff8160c4a5>] net_rx_action+0x145/0x320
  [...]

What happens is that on ingress, we push Ethernet header back in, either
from cls_bpf or right before skb_do_redirect(), but without updating csum.
The "hw csum failure" can be fixed by using the new skb_postpush_rcsum()
helper for the dev_forward_skb() case to correct the csum diff again.

Thanks to Hannes Frederic Sowa for the csum_partial() idea!

Fixes: 3896d655 ("bpf: introduce bpf_clone_redirect() helper")
Fixes: 27b29f63 ("bpf: add bpf_redirect() helper")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a skb_at_tc_ingress() as this will be needed elsewhere as well and
can hide the ugly ifdef.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is the final part required to namespaceify the tcp
keep alive mechanism.
Signed-off-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is required to have full tcp keepalive mechanism namespace
support.
Signed-off-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Different net namespaces might have different requirements as to
the keepalive time of tcp sockets. This might be required in cases
where different firewall rules are in place which require tcp
timeout sockets to be increased/decreased independently of the host.
Signed-off-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

udp tunnel offloads tend to aggregate datagrams based on inner
headers. gro engine gets notified by tunnel implementations about
possible offloads. The match is solely based on the port number.

Imagine a tunnel bound to port 53, the offloading will look into all
DNS packets and tries to aggregate them based on the inner data found
within. This could lead to data corruption and malformed DNS packets.

While this patch minimizes the problem and helps an administrator to find
the issue by querying ip tunnel/fou, a better way would be to match on
the specific destination ip address so if a user space socket is bound
to the same address it will conflict.

Cc: Tom Herbert <tom@herbertland.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Define HW multicast entry: MAC and VID.
Using a MAC address simplifies support for both IPV4 and IPv6.
Signed-off-by: NElad Raz <eladr@mellanox.com>
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>

We need information about exports when crossing mountpoints during
lookup or NFSv4 readdir.  If we don't already have that information
cached, we may have to ask (and wait for) rpc.mountd.

In both cases we currently hold the i_mutex on the parent of the
directory we're asking rpc.mountd about.  We've seen situations where
rpc.mountd performs some operation on that directory that tries to take
the i_mutex again, resulting in deadlock.

With some care, we may be able to avoid that in rpc.mountd.  But it
seems better just to avoid holding a mutex while waiting on userspace.

It appears that lookup_one_len is pretty much the only operation that
needs the i_mutex.  So we could just drop the i_mutex elsewhere and do
something like

	mutex_lock()
	lookup_one_len()
	mutex_unlock()

In many cases though the lookup would have been cached and not required
the i_mutex, so it's more efficient to create a lookup_one_len() variant
that only takes the i_mutex when necessary.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Move the details behind the cb[] access into a small helper to decouple
and make them generic for bpf_prog_run_save_cb()/bpf_prog_run_clear_cb()
that was introduced via commit ff936a04 ("bpf: fix cb access in socket
filter programs"). Also add a comment to better clarify what is done in
bpf_skb_cb().
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib_multipath_hash() computes a hash using __be32 values, force
cast these to u32 to pacify sparse.
Signed-off-by: NLance Richardson <lrichard@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>