Re: [dpdk-dev] [PATCH v3 3/3] doc: update for conntrack

[Bing Zhao <bingz@nvidia.com>]

Hi Ajit,

> -----Original Message-----
> From: Ajit Khaparde <ajit.khaparde@broadcom.com>
> Sent: Saturday, April 17, 2021 2:30 AM
> To: Bing Zhao <bingz@nvidia.com>
> Cc: Ori Kam <orika@nvidia.com>; NBU-Contact-Thomas Monjalon
> <thomas@monjalon.net>; Ferruh Yigit <ferruh.yigit@intel.com>; Andrew
> Rybchenko <andrew.rybchenko@oktetlabs.ru>; dpdk-dev <dev@dpdk.org>;
> Xiaoyun Li <xiaoyun.li@intel.com>
> Subject: Re: [PATCH v3 3/3] doc: update for conntrack
> 
> On Fri, Apr 16, 2021 at 10:54 AM Bing Zhao <bingz@nvidia.com> wrote:
> >
> > The updated documentations include:
> >   1. Release notes
> >   2. rte_flow.rst
> >   3. testpmd user guide
> >
> > Signed-off-by: Bing Zhao <bingz@nvidia.com>
> > ---
> >  doc/guides/prog_guide/rte_flow.rst          | 113
> ++++++++++++++++++++
> >  doc/guides/rel_notes/release_21_05.rst      |   4 +
> >  doc/guides/testpmd_app_ug/testpmd_funcs.rst |  35 ++++++
> >  3 files changed, 152 insertions(+)
> >
> > diff --git a/doc/guides/prog_guide/rte_flow.rst
> b/doc/guides/prog_guide/rte_flow.rst
> > index 2ecc48cfff..a1333819fc 100644
> > --- a/doc/guides/prog_guide/rte_flow.rst
> > +++ b/doc/guides/prog_guide/rte_flow.rst
> > @@ -1398,6 +1398,14 @@ Matches a eCPRI header.
> >  - ``hdr``: eCPRI header definition (``rte_ecpri.h``).
> >  - Default ``mask`` matches nothing, for all eCPRI messages.
> >
> > +Item: ``CONNTRACK``
> > +^^^^^^^^^^^^^^^^^^^
> > +
> > +Matches a conntrack state after conntrack action.
> > +
> > +- ``flags``: conntrack packet state flags.
> > +- Default ``mask`` matches all state bits.
> > +
> >  Actions
> >  ~~~~~~~
> >
> > @@ -2842,6 +2850,111 @@ for ``RTE_FLOW_FIELD_VALUE`` and
> ``RTE_FLOW_FIELD_POINTER`` respectively.
> >     | ``value``     | immediate value or a pointer to this value
> |
> >     +---------------+---------------------------------------------
> -------------+
> >
> > +Action: ``CONNTRACK``
> > +^^^^^^^^^^^^^^^^^^^^^
> > +
> > +Create a conntrack (connection tracking) context with the
> provided information.
> > +
> > +In stateful session like TCP, the conntrack action provides the
> ability to
> > +examine every packet of this connection and associate the state
> to every
> > +packet. It will help to realize the stateful offloading with
> little software
> s/stateful offloading/stateful offload of connections
> 
> > +participation. For example, only the control packets like SYN /
> FIN or packets
> > +with invalid state should be handled by the software.
> s/invalid state should be handled by the software/invalid state may
> be
> handled by the software while the rest of the control frames may be
> handled in hardware.
> 

I updated this part, please take a review.
In general, the control packets could be handled by HW and SW could get
a state change state of the packet. The SW could also handle the control
packet if there is a flow rule for the state change.

> > +
> > +A conntrack context should be created via
> ``rte_flow_action_handle_create()``
> > +before using. Then the handle with ``INDIRECT`` type is used for
> a flow rule
> > +creation. If a flow rule with an opposite direction needs to be
> created, the
> > +``rte_flow_action_handle_update()`` should be used to modify the
> direction.
> > +
> > +Not all the fields of the ``struct rte_flow_action_conntrack``
> will be used
> > +for a conntrack context creating, depending on the HW.
> s/context creating/context creation.
> s/depending on the HW./This capability will depend on the underlying
> hardware
> 
> > +The ``struct rte_flow_modify_conntrack`` should be used for an
> updating.
> > +
> > +The current conntrack context information could be queried via
> the
> > +``rte_flow_action_handle_query()`` interface.
> > +
> > +.. _table_rte_flow_action_conntrack:
> > +
> > +.. table:: CONNTRACK
> > +
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | Field                    | Value
> |
> > +
> +==========================+========================================
> =====================+
> > +   | ``peer_port``            | peer port number
> |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``is_original_dir``      | direction of this connection for
> flow rule creating         |
> s/for flow rule creating/for creating flow rule
> 
> 
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``enable``               | enable the conntrack context
> |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``live_connection``      | one ack was seen for this
> connection                        |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``selective_ack``        | SACK enabled
> |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``challenge_ack_passed`` | a challenge ack has passed
> |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``last_direction``       | direction of the last passed
> packet                         |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``liberal_mode``         | only report state change
> |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``state``                | current state
> |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``max_ack_window``       | maximal window scaling factor
> |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``retransmission_limit`` | maximal retransmission times
> |
> s/times/limit
> 
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``original_dir``         | TCP parameters of the original
> direction                    |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``reply_dir``            | TCP parameters of the reply
> direction                       |
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``last_window``          | window value of the last passed
> packet                      |
> s/value/size

Done

> 
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``last_seq``             | sequence value of the last passed
> packet                    |
> s/value/number

Agree, thanks

> 
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``last_ack``             | acknowledgement value the last
> passed packet                |
> s/value/number

Thanks

> 
> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +   | ``last_end``             | sum acknowledgement and length
> value the last passed packet |
> sum of ack number and length of the last passed packet
> or
> sum of acknowledgement number and length of the last passed packet
> 

Updated, thanks. Also update the typo

> > +   +--------------------------+----------------------------------
> ---------------------------+
> > +
> > +.. _table_rte_flow_tcp_dir_param:
> > +
> > +.. table:: configuration parameters for each direction
> > +
> > +   +---------------------+---------------------------------------
> ------------------+
> > +   | Field               | Value
> |
> > +
> +=====================+=============================================
> ============+
> > +   | ``scale``           | TCP window scaling factor
> |
> > +   +---------------------+---------------------------------------
> ------------------+
> > +   | ``close_initiated`` | FIN sent from this direction
> |
> > +   +---------------------+---------------------------------------
> ------------------+
> > +   | ``last_ack_seen``   | an ACK packet received
> |
> > +   +---------------------+---------------------------------------
> ------------------+
> > +   | ``data_unacked``    | unacknowledged data for packets from
> this direction     |
> > +   +---------------------+---------------------------------------
> ------------------+
> > +   | ``sent_end``        | max{seq + len} seen in sent packets
> |
> > +   +---------------------+---------------------------------------
> ------------------+
> > +   | ``reply_end``       | max{sack + max{win, 1}} seen in reply
> packets           |
> > +   +---------------------+---------------------------------------
> ------------------+
> > +   | ``max_win``         | max{max{win, 1}} + {sack - ack} seen
> in sent packets    |
> > +   +---------------------+---------------------------------------
> ------------------+
> > +   | ``max_ack``         | max{ack} + seen in sent packets
> |
> > +   +---------------------+---------------------------------------
> ------------------+
> > +
> > +.. _table_rte_flow_modify_conntrack:
> > +
> > +.. table:: update a conntrack context
> > +
> > +   +----------------+---------------------------------------+
> > +   | Field          | Value                                 |
> > +   +================+=======================================+
> > +   | ``new_ct``     | new conntrack information             |
> > +   +----------------+---------------------------------------+
> > +   | ``direction``  | direction will be updated             |
> > +   +----------------+---------------------------------------+
> > +   | ``state``      | other fields except will be updated   |
> except what?
> direction??

Yes, missed this word, updated.

> 
> > +   +----------------+---------------------------------------+
> > +   | ``reserved``   | reserved bits                         |
> > +   +----------------+---------------------------------------+
> > +
> >  Negative types
> >  ~~~~~~~~~~~~~~
> >
> > diff --git a/doc/guides/rel_notes/release_21_05.rst
> b/doc/guides/rel_notes/release_21_05.rst
> > index e6f99350af..824eb72981 100644
> > --- a/doc/guides/rel_notes/release_21_05.rst
> > +++ b/doc/guides/rel_notes/release_21_05.rst
> > @@ -183,6 +183,10 @@ New Features
> >      the events across multiple stages.
> >    * This also reduced the scheduling overhead on a event device.
> >
> > +* **Added conntrack support for rte_flow.**
> > +
> > +  * Added conntrack action and item for stateful offloading.
> > +
> >  * **Updated testpmd.**
> >
> >    * Added a command line option to configure forced speed for
> Ethernet port.
> > diff --git a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> > index 1fa6e2000e..4c029776aa 100644
> > --- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> > +++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> > @@ -3791,6 +3791,8 @@ This section lists supported pattern items
> and their attributes, if any.
> >    - ``s_field {unsigned}``: S field.
> >    - ``seid {unsigned}``: session endpoint identifier.
> >
> > +- ``conntrack``: match conntrack state.
> > +
> >  Actions list
> >  ^^^^^^^^^^^^
> >
> > @@ -4925,6 +4927,39 @@ NVGRE encapsulation header and sent to port
> id 0.
> >   testpmd> flow create 0 ingress transfer pattern eth / end
> actions
> >          sample ratio 1 index 0  / port_id id 2 / end
> >
> > +Sample conntrack rules
> > +~~~~~~~~~~~~~~~~~~~~~~
> > +
> > +Conntrack rules can be set by the following commands
> > +
> > +Need to construct the connection context with provided
> information.
> > +In the first table, create a flow rule by using conntrack action
> and jump to
> > +the next table. In the next table, create a rule to check the
> state.
> > +
> > +::
> > +
> > + testpmd> set conntrack com peer 1 is_orig 1 enable 1 live 1 sack
> 1 cack 0
> > +        last_dir 0 liberal 0 state 1 max_ack_win 7 r_lim 5
> last_win 510
> > +        last_seq 2632987379 last_ack 2532480967 last_end
> 2632987379
> > +        last_index 0x8
> > + testpmd> set conntrack orig scale 7 fin 0 acked 1 unack_data 0
> > +        sent_end 2632987379 reply_end 2633016339 max_win 28960
> > +        max_ack 2632987379
> > + testpmd> set conntrack rply scale 7 fin 0 acked 1 unack_data 0
> > +        sent_end 2532480967 reply_end 2532546247 max_win 65280
> > +        max_ack 2532480967
> > + testpmd> flow indirect_action 0 create ingress action conntrack
> / end
> > + testpmd> flow create 0 group 3 ingress pattern eth / ipv4 / tcp
> / end actions indirect 0 / jump group 5 / end
> > + testpmd> flow create 0 group 5 ingress pattern eth / ipv4 / tcp
> / conntrack is 1 / end actions queue index 5 / end
> > +
> > +Construct the conntrack again with only "is_orig" set to 0 (other
> fields are
> > +ignored), then use "update" interface to update the direction.
> Create flow
> s/use/use the
> 
> > +rules like above for the peer port.
> By peer, do you mean peer system? Or remote/dst port of the TCP
> connection?

The peer port of the conntrack. One conntrack context should only be used for
a bi-dir traffic from to same ethdev port or between a pair of ethdev ports.

> 
> > +
> > +::
> > +
> > + testpmd> flow indirect_action 0 update 0 action conntrack_update
> dir / end
> > +
> >  BPF Functions
> >  --------------
> >
> > --
> > 2.19.0.windows.1
> >