Re: [dpdk-dev] [PATCH v9 1/3] ethdev: add actions to modify TCP header fields

[Dekel Peled <dekelp@mellanox.com>]

Thanks, PSB.

> -----Original Message-----
> From: Adrien Mazarguil <adrien.mazarguil@6wind.com>
> Sent: Tuesday, July 2, 2019 1:33 PM
> To: Dekel Peled <dekelp@mellanox.com>
> Cc: Andrew Rybchenko <arybchenko@solarflare.com>;
> wenzhuo.lu@intel.com; jingjing.wu@intel.com;
> bernard.iremonger@intel.com; Yongseok Koh <yskoh@mellanox.com>;
> Shahaf Shuler <shahafs@mellanox.com>; Slava Ovsiienko
> <viacheslavo@mellanox.com>; dev@dpdk.org; Ori Kam
> <orika@mellanox.com>
> Subject: Re: [dpdk-dev] [PATCH v9 1/3] ethdev: add actions to modify TCP
> header fields
> 
> On Tue, Jul 02, 2019 at 09:52:40AM +0000, Dekel Peled wrote:
> > Thanks, PSB
> >
> > > -----Original Message-----
> > > From: Andrew Rybchenko <arybchenko@solarflare.com>
> > > Sent: Tuesday, July 2, 2019 11:14 AM
> > > To: Dekel Peled <dekelp@mellanox.com>; Adrien Mazarguil
> > > <adrien.mazarguil@6wind.com>; wenzhuo.lu@intel.com;
> > > jingjing.wu@intel.com; bernard.iremonger@intel.com; Yongseok Koh
> > > <yskoh@mellanox.com>; Shahaf Shuler <shahafs@mellanox.com>; Slava
> > > Ovsiienko <viacheslavo@mellanox.com>; arybchenko@solarflare.com
> > > Cc: dev@dpdk.org; Ori Kam <orika@mellanox.com>
> > > Subject: Re: [dpdk-dev] [PATCH v9 1/3] ethdev: add actions to modify
> > > TCP header fields
> > >
> > > On 01.07.2019 18:43, Dekel Peled wrote:
> > > > Add actions:
> > > > - INC_TCP_SEQ - Increase sequence number in the outermost TCP
> header.
> > > > - DEC_TCP_SEQ - Decrease sequence number in the outermost TCP
> > > header.
> > > > - INC_TCP_ACK - Increase acknowledgment number in the outermost
> TCP
> > > > 		header.
> > > > - DEC_TCP_ACK - Decrease acknowledgment number in the outermost
> TCP
> > > > 		header.
> > > >
> > > > Original work by Xiaoyu Min.
> > > >
> > > > This patch uses the new approach introduced by [1], using a simple
> > > > integer instead of using an action-specific structure for each of
> > > > the new actions.
> > > >
> > > > [1]
> > > >
> > > http://patch
> > > >
> > >
> es.dpdk.org%2Fpatch%2F55773%2F&amp;data=02%7C01%7Cdekelp%40mell
> > > anox.co
> > > >
> > >
> m%7Cae3a2667c3a243a9c1e508d6fec54a22%7Ca652971c7d2e4d9ba6a4d1492
> > > 56f461
> > > >
> > >
> b%7C0%7C0%7C636976520663069258&amp;sdata=1z3uDQGnnyPZH9NAUuY5
> > > 0ZSg3smyZ
> > > > nDmc3QZtuNTmyg%3D&amp;reserved=0
> > > >
> > > > Signed-off-by: Dekel Peled <dekelp@mellanox.com>
> > > > Acked-by: Andrew Rybchenko <arybchenko@solarflare.com>
> > > > ---
> > > >   doc/guides/prog_guide/rte_flow.rst | 32
> > > ++++++++++++++++++++++++++++++++
> > > >   lib/librte_ethdev/rte_flow.c       |  4 ++++
> > > >   lib/librte_ethdev/rte_flow.h       | 32
> > > ++++++++++++++++++++++++++++++++
> > > >   3 files changed, 68 insertions(+)
> > > >
> > > > diff --git a/doc/guides/prog_guide/rte_flow.rst
> > > > b/doc/guides/prog_guide/rte_flow.rst
> > > > index 67deed7..bbe32db 100644
> > > > --- a/doc/guides/prog_guide/rte_flow.rst
> > > > +++ b/doc/guides/prog_guide/rte_flow.rst
> > > > @@ -2346,6 +2346,38 @@ Otherwise,
> RTE_FLOW_ERROR_TYPE_ACTION
> > > error will be returned.
> > > >      | ``mac_addr`` | MAC address   |
> > > >      +--------------+---------------+
> > > >
> > > > +Action: ``INC_TCP_SEQ``
> > > > +^^^^^^^^^^^^^^^^^^^^^^^
> > > > +
> > > > +Increase sequence number in the outermost TCP header.
> > > > +Value to increase TCP sequence number by is a big-endian 32 bit
> integer.
> > > > +
> > > > +Using this action on non-matching traffic will result in undefined
> behavior.
> > > > +
> > > > +Action: ``DEC_TCP_SEQ``
> > > > +^^^^^^^^^^^^^^^^^^^^^^^
> > > > +
> > > > +Decrease sequence number in the outermost TCP header.
> > > > +Value to decrease TCP sequence number by is a big-endian 32 bit
> integer.
> > > > +
> > > > +Using this action on non-matching traffic will result in undefined
> behavior.
> > > > +
> > > > +Action: ``INC_TCP_ACK``
> > > > +^^^^^^^^^^^^^^^^^^^^^^^
> > > > +
> > > > +Increase acknowledgment number in the outermost TCP header.
> > > > +Value to increase TCP acknowledgment number by is a big-endian 32
> > > > +bit
> > > integer.
> > > > +
> > > > +Using this action on non-matching traffic will result in undefined
> behavior.
> > > > +
> > > > +Action: ``DEC_TCP_ACK``
> > > > +^^^^^^^^^^^^^^^^^^^^^^^
> > > > +
> > > > +Decrease acknowledgment number in the outermost TCP header.
> > > > +Value to decrease TCP acknowledgment number by is a big-endian 32
> > > > +bit
> > > integer.
> > > > +
> > > > +Using this action on non-matching traffic will result in undefined
> behavior.
> > > > +
> > > >   Negative types
> > > >   ~~~~~~~~~~~~~~
> > > >
> > > > diff --git a/lib/librte_ethdev/rte_flow.c
> > > > b/lib/librte_ethdev/rte_flow.c index 3277be1..0c9f6c6 100644
> > > > --- a/lib/librte_ethdev/rte_flow.c
> > > > +++ b/lib/librte_ethdev/rte_flow.c
> > > > @@ -143,6 +143,10 @@ struct rte_flow_desc_data {
> > > >   	MK_FLOW_ACTION(SET_TTL, sizeof(struct rte_flow_action_set_ttl)),
> > > >   	MK_FLOW_ACTION(SET_MAC_SRC, sizeof(struct
> > > rte_flow_action_set_mac)),
> > > >   	MK_FLOW_ACTION(SET_MAC_DST, sizeof(struct
> > > > rte_flow_action_set_mac)),
> > > > +	MK_FLOW_ACTION(INC_TCP_SEQ, sizeof(rte_be32_t)),
> > > > +	MK_FLOW_ACTION(DEC_TCP_SEQ, sizeof(rte_be32_t)),
> > > > +	MK_FLOW_ACTION(INC_TCP_ACK, sizeof(rte_be32_t)),
> > > > +	MK_FLOW_ACTION(DEC_TCP_ACK, sizeof(rte_be32_t)),
> > > >   };
> > > >
> > > >   static int
> > > > diff --git a/lib/librte_ethdev/rte_flow.h
> > > > b/lib/librte_ethdev/rte_flow.h index 2232856..28445f4 100644
> > > > --- a/lib/librte_ethdev/rte_flow.h
> > > > +++ b/lib/librte_ethdev/rte_flow.h
> > > > @@ -1651,6 +1651,38 @@ enum rte_flow_action_type {
> > > >   	 * See struct rte_flow_action_set_mac.
> > > >   	 */
> > > >   	RTE_FLOW_ACTION_TYPE_SET_MAC_DST,
> > > > +
> > > > +	/**
> > > > +	 * Increase sequence number in the outermost TCP header.
> > > > +	 *
> > > > +	 * Using this action on non-matching traffic will result in
> > > > +	 * undefined behavior.
> > > > +	 */
> > > > +	RTE_FLOW_ACTION_TYPE_INC_TCP_SEQ,
> > > > +
> > > > +	/**
> > > > +	 * Decrease sequence number in the outermost TCP header.
> > > > +	 *
> > > > +	 * Using this action on non-matching traffic will result in
> > > > +	 * undefined behavior.
> > > > +	 */
> > > > +	RTE_FLOW_ACTION_TYPE_DEC_TCP_SEQ,
> > > > +
> > > > +	/**
> > > > +	 * Increase acknowledgment number in the outermost TCP header.
> > > > +	 *
> > > > +	 * Using this action on non-matching traffic will result in
> > > > +	 * undefined behavior.
> > > > +	 */
> > > > +	RTE_FLOW_ACTION_TYPE_INC_TCP_ACK,
> > > > +
> > > > +	/**
> > > > +	 * Decrease acknowledgment number in the outermost TCP header.
> > > > +	 *
> > > > +	 * Using this action on non-matching traffic will result in
> > > > +	 * undefined behavior.
> > > > +	 */
> > > > +	RTE_FLOW_ACTION_TYPE_DEC_TCP_ACK,
> > > >   };
> > > >
> > > >   /**
> > >
> > > Other actions have type of configuration data description in a
> > > comment just before the action enum element. I'm not sure why it is
> skipped here.
> > > It is really vital information.
> > >
> >
> > I had the relevant struct name here, and removed it when I changed it to
> integer.
> > In the documentation doc/guides/prog_guide/rte_flow.rst  I added
> description, please see above.
> 
> Yes, still Andrew is right, header documentation must be exhaustive.
> Developers might use rte_flow.rst as reference and to understand the
> underlying design but will definitely rely on rte_flow.h (and Doxygen) when
> writing code.
> 
> I suggest something which describes types and how they are used a bit like
> enum rte_flow_conv_op, e.g. for RTE_FLOW_ACTION_TYPE_DEC_TCP_ACK:
> 
>  [...]
>  *
>  * Action configuration specifies the value to decrease TCP acknowledgment
>  * number as a big-endian 32 bit integer.
>  *
>  * @p conf type:
>  * @code const rte_be32_t * @endcode
>  */
> 
> I know other actions do not have the same format but we'll update them
> eventually.

Agree, I'll add this documentation.

> 
> --
> Adrien Mazarguil
> 6WIND