TC actions are no longer freed in RCU callbacks and we should
always have RTNL lock, so this spinlock is no longer needed.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcfm_dev always points to the correct netdev and we already
hold a refcnt, so no need to use tcfm_ifindex to lookup again.

If we would support moving target netdev across netns, using
pointer would be better than ifindex.

This also fixes dumping obsolete ifindex, now after the
target device is gone we just dump 0 as ifindex.

Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No one actually uses it.

Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes the following checkpatch error:

ERROR: do not use assignment in if condition

by rearranging the if condition to execute init callback only if init
callback exists. The whole setup afterwards is called in any case,
doesn't matter if init callback is set or not. This patch has the same
behaviour as before, just without assign err variable in if condition.
It also makes the code easier to read.
Reviewed-by: NJamal Hadi Salim <jhs@mojatatu.com>
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: NAlexander Aring <aring@mojatatu.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fix checkpatch issues for upcomming patches according to the
sched api file. It changes checking on null pointer, remove unnecessary
brackets, add variable names for parameters and adjust 80 char width.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: NAlexander Aring <aring@mojatatu.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both Eric and Paolo noticed the rcu_barrier() we use in
tcf_block_put_ext() could be a performance bottleneck when
we have a lot of tc classes.

Paolo provided the following to demonstrate the issue:

tc qdisc add dev lo root htb
for I in `seq 1 1000`; do
        tc class add dev lo parent 1: classid 1:$I htb rate 100kbit
        tc qdisc add dev lo parent 1:$I handle $((I + 1)): htb
        for J in `seq 1 10`; do
                tc filter add dev lo parent $((I + 1)): u32 match ip src 1.1.1.$J
        done
done
time tc qdisc del dev root

real    0m54.764s
user    0m0.023s
sys     0m0.000s

The rcu_barrier() there is to ensure we free the block after all chains
are gone, that is, to queue tcf_block_put_final() at the tail of workqueue.
We can achieve this ordering requirement by refcnt'ing tcf block instead,
that is, the tcf block is freed only when the last chain in this block is
gone. This also simplifies the code.

Paolo reported after this patch we get:

real    0m0.017s
user    0m0.000s
sys     0m0.017s
Tested-by: NPaolo Abeni <pabeni@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move dissection of tunnel info to outside of the main flow dissection
function, __skb_flow_dissect(). The sole user of this feature, the flower
classifier, is updated to call tunnel info dissection directly, using
skb_flow_dissect_tunnel_info().

This results in a slightly less complex implementation of
__skb_flow_dissect(), in particular removing logic from that call path
which is not used by the majority of users. The expense of this is borne by
the flower classifier which now has to make an extra call for tunnel info
dissection.

This patch should not result in any behavioural change.
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to commit d7fb60b9 ("net_sched: get rid of tcfa_rcu"),
TC actions don't need to respect RCU grace period, because it
is either just detached from tc filter (standalone case) or
it is removed together with tc filter (bound case) in which case
RCU grace period is already respected at filter layer.

Fixes: 5c5670fa ("net/sched: Introduce sample tc action")
Reported-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Yotam Gigi <yotamg@mellanox.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

q->link.block is not initialized, that leads to EINVAL when one tries to
add filter there. So initialize it properly.

This can be reproduced by:
$ tc qdisc add dev eth0 root handle 1: cbq avpkt 1000 rate 1000Mbit bandwidth 1000Mbit
$ tc filter add dev eth0 parent 1: protocol ip prio 100 u32 match ip protocol 0 0x00 flowid 1:1
Reported-by: NJaroslav Aster <jaster@redhat.com>
Reported-by: NIvan Vecera <ivecera@redhat.com>
Fixes: 6529eaba ("net: sched: introduce tcf block infractructure")
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NEelco Chaudron <echaudro@redhat.com>
Reviewed-by: NIvan Vecera <ivecera@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While converting sch_sfq to use timer_setup(), the commit cdeabbb8
("net: sched: Convert timers to use timer_setup()") forgot to
initialize the 'sch' field. As a result, the timer callback tries to
dereference a NULL pointer, and the kernel does oops.

Fix it initializing such field at qdisc creation time.

Fixes: cdeabbb8 ("net: sched: Convert timers to use timer_setup()")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When cls_bpf offload was added it seemed like a good idea to
call cls_bpf_delete_prog() instead of extending the error
handling path, since the software state is fully initialized
at that point.  This handling of errors without jumping to
the end of the function is error prone, as proven by later
commit missing that extra call to __cls_bpf_delete_prog().

__cls_bpf_delete_prog() is now expected to be invoked with
a reference on exts->net or the field zeroed out.  The call
on the offload's error patch does not fullfil this requirement,
leading to each error stealing a reference on net namespace.

Create a function undoing what cls_bpf_set_parms() did and
use it from __cls_bpf_delete_prog() and the error path.

Fixes: aae2c35e ("cls_bpf: use tcf_exts_get_net() before call_rcu()")
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcf_block_put_ext has assumed that all filters (and thus their goto
actions) are destroyed in RCU callback and thus can not race with our
list iteration. However, that is not true during netns cleanup (see
tcf_exts_get_net comment).

Prevent the user after free by holding all chains (except 0, that one is
already held). foreach_safe is not enough in this case.

To reproduce, run the following in a netns and then delete the ns:
    ip link add dtest type dummy
    tc qdisc add dev dtest ingress
    tc filter add dev dtest chain 1 parent ffff: handle 1 prio 1 flower action goto chain 2

Fixes: 822e86d9 ("net_sched: remove tcf_block_put_deferred()")
Signed-off-by: NRoman Kapl <code@rkapl.cz>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Tuntap and similar devices can inject GSO packets. Accept type
VIRTIO_NET_HDR_GSO_UDP, even though not generating UFO natively.

Processes are expected to use feature negotiation such as TUNSETOFFLOAD
to detect supported offload types and refrain from injecting other
packets. This process breaks down with live migration: guest kernels
do not renegotiate flags, so destination hosts need to expose all
features that the source host does.

Partially revert the UFO removal from 182e0b6b~1..d9d30adf.
This patch introduces nearly(*) no new code to simplify verification.
It brings back verbatim tuntap UFO negotiation, VIRTIO_NET_HDR_GSO_UDP
insertion and software UFO segmentation.

It does not reinstate protocol stack support, hardware offload
(NETIF_F_UFO), SKB_GSO_UDP tunneling in SKB_GSO_SOFTWARE or reception
of VIRTIO_NET_HDR_GSO_UDP packets in tuntap.

To support SKB_GSO_UDP reappearing in the stack, also reinstate
logic in act_csum and openvswitch. Achieve equivalence with v4.13 HEAD
by squashing in commit 93991221 ("net: skb_needs_check() removes
CHECKSUM_UNNECESSARY check for tx.") and reverting commit 8d63bee6
("net: avoid skb_warn_bad_offload false positives on UFO").

(*) To avoid having to bring back skb_shinfo(skb)->ip6_frag_id,
ipv6_proxy_select_ident is changed to return a __be32 and this is
assigned directly to the frag_hdr. Also, SKB_GSO_UDP is inserted
at the end of the enum to minimize code churn.

Tested
  Booted a v4.13 guest kernel with QEMU. On a host kernel before this
  patch `ethtool -k eth0` shows UFO disabled. After the patch, it is
  enabled, same as on a v4.13 host kernel.

  A UFO packet sent from the guest appears on the tap device:
    host:
      nc -l -p -u 8000 &
      tcpdump -n -i tap0

    guest:
      dd if=/dev/zero of=payload.txt bs=1 count=2000
      nc -u 192.16.1.1 8000 < payload.txt

  Direct tap to tap transmission of VIRTIO_NET_HDR_GSO_UDP succeeds,
  packets arriving fragmented:

    ./with_tap_pair.sh ./tap_send_ufo tap0 tap1
    (from https://github.com/wdebruij/kerneltools/tree/master/tests)

Changes
  v1 -> v2
    - simplified set_offload change (review comment)
    - documented test procedure

Link: http://lkml.kernel.org/r/<CAF=yD-LuUeDuL9YWPJD9ykOZ0QCjNeznPDr6whqZ9NGMNF12Mw@mail.gmail.com>
Fixes: fb652fdf ("macvlan/macvtap: Remove NETIF_F_UFO advertisement.")
Reported-by: NMichal Kubecek <mkubecek@suse.cz>
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If you flush (delete) a filter chain other than chain 0 (such as when
deleting the device), the kernel may run into a use-after-free. The
chain refcount must not be decremented unless we are sure we are done
with the chain.

To reproduce the bug, run:
    ip link add dtest type dummy
    tc qdisc add dev dtest ingress
    tc filter add dev dtest chain 1  parent ffff: flower
    ip link del dtest

Introduced in: commit f93e1cdc ("net/sched: fix filter flushing"),
but unless you have KAsan or luck, you won't notice it until
commit 0dadc117 ("cls_flower: use tcf_exts_get_net() before call_rcu()")

Fixes: f93e1cdc ("net/sched: fix filter flushing")
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NRoman Kapl <code@rkapl.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With TC shared block changes we can't depend on correct netdev
pointer being available in cls_bpf.  Move the device validation
to the driver.  Core will only make sure that offloaded programs
are always attached in the driver (or in HW by the driver).  We
trust that drivers which implement offload callbacks will perform
necessary checks.

Moving the checks to the driver is generally a useful thing,
in practice the check should be against a switchdev instance,
not a netdev, given that most ASICs will probably allow using
the same program on many ports.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Fix compilation on 32 bit platforms (where doing modulus operation
with 64 bit requires extra glibc functions) by truncation.
The jitter for table distribution is limited to a 32 bit value
because random numbers are scaled as 32 bit value.

Also fix some whitespace.

Fixes: 99803171 ("netem: add uapi to express delay and jitter in nanoseconds")
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since times are now expressed in nanosecond, need to now do
true 64 bit divide. Old code would truncate rate at 32 bits.
Rename function to better express current usage.
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

gcc-4.4.4 (at lest) has issues with initializers and anonymous unions:

net/sched/sch_red.c: In function 'red_dump_offload':
net/sched/sch_red.c:282: error: unknown field 'stats' specified in initializer
net/sched/sch_red.c:282: warning: initialization makes integer from pointer without a cast
net/sched/sch_red.c:283: error: unknown field 'stats' specified in initializer
net/sched/sch_red.c:283: warning: initialization makes integer from pointer without a cast
net/sched/sch_red.c: In function 'red_dump_stats':
net/sched/sch_red.c:352: error: unknown field 'xstats' specified in initializer
net/sched/sch_red.c:352: warning: initialization makes integer from pointer without a cast

Work around this.

Fixes: 602f3baf ("net_sch: red: Add offload ability to RED qdisc")
Cc: Nogah Frankel <nogahf@mellanox.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Simon Horman <simon.horman@netronome.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Slotting is a crude approximation of the behaviors of shared media such
as cable, wifi, and LTE, which gather up a bunch of packets within a
varying delay window and deliver them, relative to that, nearly all at
once.

It works within the existing loss, duplication, jitter and delay
parameters of netem. Some amount of inherent latency must be specified,
regardless.

The new "slot" parameter specifies a minimum and maximum delay between
transmission attempts.

The "bytes" and "packets" parameters can be used to limit the amount of
information transferred per slot.

Examples of use:

tc qdisc add dev eth0 root netem delay 200us \
         slot 800us 10ms bytes 64k packets 42

A more correct example, using stacked netem instances and a packet limit
to emulate a tail drop wifi queue with slots and variable packet
delivery, with a 200Mbit isochronous underlying rate, and 20ms path
delay:

tc qdisc add dev eth0 root handle 1: netem delay 20ms rate 200mbit \
         limit 10000
tc qdisc add dev eth0 parent 1:1 handle 10:1 netem delay 200us \
         slot 800us 10ms bytes 64k packets 42 limit 512
Signed-off-by: NDave Taht <dave.taht@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

netem userspace has long relied on a horrible /proc/net/psched hack
to translate the current notion of "ticks" to nanoseconds.

Expressing latency and jitter instead, in well defined nanoseconds,
increases the dynamic range of emulated delays and jitter in netem.

It will also ease a transition where reducing a tick to nsec
equivalence would constrain the max delay in prior versions of
netem to only 4.3 seconds.
Signed-off-by: NDave Taht <dave.taht@gmail.com>
Suggested-by: NEric Dumazet <edumazet@google.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Upgrade the internal netem scheduler to use nanoseconds rather than
ticks throughout.

Convert to and from the std "ticks" userspace api automatically,
while allowing for finer grained scheduling to take place.
Signed-off-by: NDave Taht <dave.taht@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using a spinlock in the VLAN action causes performance issues when the VLAN
action is used on multiple cores. Rewrote the VLAN action to use RCU read
locking for reads and updates instead.
All functions now use an RCU dereferenced pointer to access the VLAN action
context. Modified helper functions used by other modules, to use the RCU as
opposed to directly accessing the structure.
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NManish Kurup <manish.kurup@verizon.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The VLAN action maintains one set of stats across all cores, and uses a
spinlock to synchronize updates to it from the same. Changed this to use a
per-CPU stats context instead.
This change will result in better performance.
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NManish Kurup <manish.kurup@verizon.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of holding netns refcnt in tc actions, we can minimize
the holding time by saving it in struct tcf_exts instead. This
means we can just hold netns refcnt right before call_rcu() and
release it after tcf_exts_destroy() is done.

However, because on netns cleanup path we call tcf_proto_destroy()
too, obviously we can not hold netns for a zero refcnt, in this
case we have to do cleanup synchronously. It is fine for RCU too,
the caller cleanup_net() already waits for a grace period.

For other cases, refcnt is non-zero and we can safely grab it as
normal and release it after we are done.

This patch provides two new API for each filter to use:
tcf_exts_get_net() and tcf_exts_put_net(). And all filters now can
use the following pattern:

void __destroy_filter() {
  tcf_exts_destroy();
  tcf_exts_put_net();  // <== release netns refcnt
  kfree();
}
void some_work() {
  rtnl_lock();
  __destroy_filter();
  rtnl_unlock();
}
void some_rcu_callback() {
  tcf_queue_work(some_work);
}

if (tcf_exts_get_net())  // <== hold netns refcnt
  call_rcu(some_rcu_callback);
else
  __destroy_filter();

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit ceffcc5e.
If we hold that refcnt, the netns can never be destroyed until
all actions are destroyed by user, this breaks our netns design
which we expect all actions are destroyed when we destroy the
whole netns.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change TC_SETUP_CBS to TC_SETUP_QDISC_CBS to match the new convention..
Signed-off-by: NNogah Frankel <nogahf@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Acked-by: NVinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change TC_SETUP_MQPRIO to TC_SETUP_QDISC_MQPRIO to match the new
convention.
Signed-off-by: NNogah Frankel <nogahf@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the ability to offload RED qdisc by using ndo_setup_tc.
There are four commands for RED offloading:
* TC_RED_SET: handles set and change.
* TC_RED_DESTROY: handle qdisc destroy.
* TC_RED_STATS: update the qdiscs counters (given as reference)
* TC_RED_XSTAT: returns red xstats.

Whether RED is being offloaded is being determined every time dump action
is being called because parent change of this qdisc could change its
offload state but doesn't require any RED function to be called.
Signed-off-by: NNogah Frankel <nogahf@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If TC program is loaded with skip_sw flag, we should allow
the device-specific programs to be accepted.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>