net: sched: do not offload flows with a helper in act_ct

There is no hardware supporting ct helper offload. However, prior to this
patch, a flower filter with a helper in the ct action can be successfully
set into the HW, for example (eth1 is a bnxt NIC):

# tc qdisc add dev eth1 ingress_block 22 ingress
# tc filter add block 22 proto ip flower skip_sw ip_proto tcp \
dst_port 21 ct_state -trk action ct helper ipv4-tcp-ftp
# tc filter show dev eth1 ingress

filter block 22 protocol ip pref 49152 flower chain 0 handle 0x1
eth_type ipv4
ip_proto tcp
dst_port 21
ct_state -trk
skip_sw
in_hw in_hw_count 1 <----
action order 1: ct zone 0 helper ipv4-tcp-ftp pipe
index 2 ref 1 bind 1
used_hw_stats delayed

This might cause the flower filter not to work as expected in the HW.

This patch avoids this problem by simply returning -EOPNOTSUPP in
tcf_ct_offload_act_setup() to not allow to offload flows with a helper
in act_ct.

Fixes: a21b06e73191 ("net: sched: add helper support in act_ct")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/f8685ec7702c4a448a1371a8b34b43217b583b9d.1699898008.git.lucien.xin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

sched: act_ct: switch to per-action label counting

net->ct.labels_used was meant to convey 'number of ip/nftables rules
that need the label extension allocated'.

act_ct enables this for each net namespace, which voids all attempts
to avoid ct->ext allocation when possible.

Move this increment to the control plane to request label extension
space allocation only when its needed.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sched: add helper support in act_ct

This patch is to add helper support in act_ct for OVS actions=ct(alg=xxx)
offloading, which is corresponding to Commit cae3a2627520 ("openvswitch:
Allow attaching helpers to ct action") in OVS kernel part.

The difference is when adding TC actions family and proto cannot be got
from the filter/match, other than helper name in tb[TCA_CT_HELPER_NAME],
we also need to send the family in tb[TCA_CT_HELPER_FAMILY] and the
proto in tb[TCA_CT_HELPER_PROTO] to kernel.

Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net/sched: act_ct: Make tcf_ct_flow_table_restore_skb inline

Currently, tcf_ct_flow_table_restore_skb is exported by act_ct
module, therefore modules using it will have hard-dependency
on act_ct and will require loading it all the time.

This can lead to an unnecessary overhead on systems that do not
use hardware connection tracking action (ct_metadata action) in
the first place.

To relax the hard-dependency between the modules, we unexport this
function and make it a static inline one.

Fixes: 30b0cf90c6dd ("net/sched: act_ct: Support restoring conntrack info on skbs")
Signed-off-by: Alaa Hleihel <alaa@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched: act_ct: Enable hardware offload of flow table entires

Pass the zone's flow table instance on the flow action to the drivers.
Thus, allowing drivers to register FT add/del/stats callbacks.

Finally, enable hardware offload on the flow table instance.

Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched: act_ct: Support restoring conntrack info on skbs

Provide an API to restore the ct state pointer.

This may be used by drivers to restore the ct state if they
miss in tc chain after they already did the hardware connection
tracking action (ct_metadata action).

For example, consider the following rule on chain 0 that is in_hw,
however chain 1 is not_in_hw:

$ tc filter add dev ... chain 0 ... \
flower ... action ct pipe action goto chain 1

Packets of a flow offloaded (via nf flow table offload) by the driver
hit this rule in hardware, will be marked with the ct metadata action
(mark, label, zone) that does the equivalent of the software ct action,
and when the packet jumps to hardware chain 1, there would be a miss.

CT was already processed in hardware. Therefore, the driver's miss
handling should restore the ct state on the skb, using the provided API,
and continue the packet processing in chain 1.

Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched: act_ct: Create nf flow table per zone

Use the NF flow tables infrastructure for CT offload.

Create a nf flow table per zone.

Next patches will add FT entries to this table, and do
the software offload.

Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sched: refactor ct action helpers to require tcf_lock

In order to remove rtnl lock dependency from flow_action representation
translator, change rtnl_dereference() to rcu_dereference_protected() in ct
action helpers that provide external access to zone and action values. This
is safe to do because the functions are not called from anywhere else
outside flow_action infrastructure which was modified to obtain tcf_lock
when accessing action data in one of previous patches in the series.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched: Introduce action ct

Allow sending a packet to conntrack module for connection tracking.

The packet will be marked with conntrack connection's state, and
any metadata such as conntrack mark and label. This state metadata
can later be matched against with tc classifers, for example with the
flower classifier as below.

In addition to committing new connections the user can optionally
specific a zone to track within, set a mark/label and configure nat
with an address range and port range.

Usage is as follows:
$ tc qdisc add dev ens1f0_0 ingress
$ tc qdisc add dev ens1f0_1 ingress

$ tc filter add dev ens1f0_0 ingress \
prio 1 chain 0 proto ip \
flower ip_proto tcp ct_state -trk \
action ct zone 2 pipe \
action goto chain 2
$ tc filter add dev ens1f0_0 ingress \
prio 1 chain 2 proto ip \
flower ct_state +trk+new \
action ct zone 2 commit mark 0xbb nat src addr 5.5.5.7 pipe \
action mirred egress redirect dev ens1f0_1
$ tc filter add dev ens1f0_0 ingress \
prio 1 chain 2 proto ip \
flower ct_zone 2 ct_mark 0xbb ct_state +trk+est \
action ct nat pipe \
action mirred egress redirect dev ens1f0_1

$ tc filter add dev ens1f0_1 ingress \
prio 1 chain 0 proto ip \
flower ip_proto tcp ct_state -trk \
action ct zone 2 pipe \
action goto chain 1
$ tc filter add dev ens1f0_1 ingress \
prio 1 chain 1 proto ip \
flower ct_zone 2 ct_mark 0xbb ct_state +trk+est \
action ct nat pipe \
action mirred egress redirect dev ens1f0_0

Signed-off-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>

Changelog:
V5->V6:
Added CONFIG_NF_DEFRAG_IPV6 in handle fragments ipv6 case
V4->V5:
Reordered nf_conntrack_put() in tcf_ct_skb_nfct_cached()
V3->V4:
Added strict_start_type for act_ct policy
V2->V3:
Fixed david's comments: Removed extra newline after rcu in tcf_ct_params , and indent of break in act_ct.c
V1->V2:
Fixed parsing of ranges TCA_CT_NAT_IPV6_MAX as 'else' case overwritten ipv4 max
Refactored NAT_PORT_MIN_MAX range handling as well
Added ipv4/ipv6 defragmentation
Removed extra skb pull push of nw offset in exectute nat
Refactored tcf_ct_skb_network_trim after pull
Removed TCA_ACT_CT define

Signed-off-by: David S. Miller <davem@davemloft.net>