Re: [PATCH v3 3/4] ethdev: add TTL change actions in flow API

[Adrien Mazarguil <adrien.mazarguil@6wind.com>]

On Mon, Apr 16, 2018 at 02:10:41PM +0800, Qi Zhang wrote:
> Add couple OpenFlow frienldy TTL change actions.

frienldy => friendly

> 
> RTE_FLOW_ACTION_MLPS_TTL_DEC - decrement MPLS TTL.
> RTE_FLOW_ACTION_IP_TTL_DEC - decrement IP TTL.
> RTE_FLOW_ACTION_TTL_COPY_OUT - copy TTL outwards.
> RTE_FLOW_ACTION_TTL_COPY_IN - copy TTL inwards.
> 
> Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>

These are OpenFlow actions whose behavior is defined by the OpenFlow
specification. They must have "OF" part of their name to make this clear,
as in "RTE_FLOW_ACTION_OF_MPLS_TTL_DEC".

More below.

> ---
>  app/test-pmd/cmdline_flow.c                 | 64 +++++++++++++++++++++++
>  doc/guides/prog_guide/rte_flow.rst          | 80 +++++++++++++++++++++++++++++
>  doc/guides/testpmd_app_ug/testpmd_funcs.rst | 12 +++++
>  lib/librte_ether/rte_flow.h                 | 77 +++++++++++++++++++++++++++
>  4 files changed, 233 insertions(+)
> 
> diff --git a/app/test-pmd/cmdline_flow.c b/app/test-pmd/cmdline_flow.c
> index 7950b1b8d..417cbecc9 100644
> --- a/app/test-pmd/cmdline_flow.c
> +++ b/app/test-pmd/cmdline_flow.c
> @@ -195,6 +195,12 @@ enum index {
>  	ACTION_VF_ID,
>  	ACTION_METER,
>  	ACTION_METER_ID,
> +	ACTION_MPLS_TTL_DEC,
> +	ACTION_MPLS_TTL_DEC_LVL,
> +	ACTION_IP_TTL_DEC,
> +	ACTION_IP_TTL_DEC_LVL,
> +	ACTION_TTL_COPY_OUT,
> +	ACTION_TTL_COPY_IN,
>  };
>  
>  /** Size of pattern[] field in struct rte_flow_item_raw. */
> @@ -668,6 +674,10 @@ static const enum index next_action[] = {
>  	ACTION_PF,
>  	ACTION_VF,
>  	ACTION_METER,
> +	ACTION_MPLS_TTL_DEC,
> +	ACTION_IP_TTL_DEC,
> +	ACTION_TTL_COPY_OUT,
> +	ACTION_TTL_COPY_IN,
>  	ZERO,
>  };
>  
> @@ -708,6 +718,16 @@ static const enum index action_meter[] = {
>  	ZERO,
>  };
>  
> +static const enum index action_mpls_ttl_dec[] = {
> +	ACTION_MPLS_TTL_DEC_LVL,
> +	ZERO,
> +};
> +
> +static const enum index action_ip_ttl_dec[] = {
> +	ACTION_IP_TTL_DEC_LVL,
> +	ZERO,
> +};
> +

The OpenFlow specification doesn't mention any parameter for these
actions. Unless I'm mistaken, it doesn't have a concept of "level", please
remove them.

>  static int parse_init(struct context *, const struct token *,
>  		      const char *, unsigned int,
>  		      void *, unsigned int);
> @@ -1857,6 +1877,50 @@ static const struct token token_list[] = {
>  		.args = ARGS(ARGS_ENTRY(struct rte_flow_action_meter, mtr_id)),
>  		.call = parse_vc_conf,
>  	},
> +	[ACTION_MPLS_TTL_DEC] = {
> +		.name = "mpls_ttl_dec",

mpls_ttl_dec => of_mpls_ttl_dec

> +		.help = "decrement MPLS TTL",
> +		.priv = PRIV_ACTION(MPLS_TTL_DEC,
> +				sizeof(struct rte_flow_action_mpls_ttl_dec)),
> +		.next = NEXT(action_mpls_ttl_dec),
> +		.call = parse_vc,
> +	},
> +	[ACTION_MPLS_TTL_DEC_LVL] = {
> +		.name = "level",
> +		.help = "level of MPLS header",
> +		.next = NEXT(action_mpls_ttl_dec, NEXT_ENTRY(UNSIGNED)),
> +		.args = ARGS(ARGS_ENTRY(struct rte_flow_action_queue, index)),
> +		.call = parse_vc,
> +	},
> +	[ACTION_IP_TTL_DEC] = {
> +		.name = "ip_ttl_dec",

ip_ttl_dec => of_ip_ttl_dec

> +		.help = "decrement IPv4 TTL or IPv6 Hop Limit",
> +		.priv = PRIV_ACTION(MPLS_TTL_DEC,
> +				sizeof(struct rte_flow_action_ip_ttl_dec)),
> +		.next = NEXT(action_ip_ttl_dec),
> +		.call = parse_vc,
> +	},
> +	[ACTION_IP_TTL_DEC_LVL] = {
> +		.name = "level",
> +		.help = "level of IPv4 or IPv6 header",
> +		.next = NEXT(action_ip_ttl_dec, NEXT_ENTRY(UNSIGNED)),
> +		.args = ARGS(ARGS_ENTRY(struct rte_flow_action_queue, index)),
> +		.call = parse_vc,
> +	},
> +	[ACTION_TTL_COPY_OUT] = {
> +		.name = "ttl_copy_out",

ttl_copy_out => of_ttl_copy_out

> +		.help = "copy TTL outwards",
> +		.priv = PRIV_ACTION(DROP, 0),

Should be "PRIV_ACTION(ACTION_TTL_COPY_OUT, 0)".

> +		.next = NEXT(NEXT_ENTRY(ACTION_NEXT)),
> +		.call = parse_vc,
> +	},
> +	[ACTION_TTL_COPY_IN] = {
> +		.name = "ttl_copy_in",

ttl_copy_in => of_ttl_copy_in

> +		.help = "copy TTL inwards",
> +		.priv = PRIV_ACTION(DROP, 0),

Should be "PRIV_ACTION(ACTION_TTL_COPY_IN, 0)".

> +		.next = NEXT(NEXT_ENTRY(ACTION_NEXT)),
> +		.call = parse_vc,
> +	},
>  };
>  
>  /** Remove and return last entry from argument stack. */
> diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
> index 68deb9812..65f2d4a16 100644
> --- a/doc/guides/prog_guide/rte_flow.rst
> +++ b/doc/guides/prog_guide/rte_flow.rst
> @@ -1604,6 +1604,86 @@ contain respective protocol layer.
>     |  ``mask``     | Bit-mask applied to new_val                                       |
>     +---------------+-------------------------------------------------------------------+
>  
> +Action: ``MPLS_TTL_DEC``
> +^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +Decrement MPLS TTL, only applies to packets that contain specific MPLS
> +headers.
> +
> +.. _table_rte_flow_action_mpls_ttl_dec:
> +
> +.. table:: MPLS_TTL_DEC
> +
> +   +---------------+---------------------------------------------+
> +   | Field         | Value                                       |
> +   +===============+=============================================+
> +   | ``dir_level`` | Specify the level of MPLS header.           |
> +   |               | direction (1b)                              |
> +   |               | 0: match start from outermost.              |
> +   |               | 1: match start from innermost.              |
> +   |               | level: (31b)                                |
> +   |               | 0: outermost or innermost MPLS header       |
> +   |               | 1: next to outmost or innermost MPLS header |
> +   |               | 2: and so on ...                            |
> +   +---------------+---------------------------------------------+

No need to document dir and level for the above reasons.

You must describe how it's an OpenFlow action and provide a link to the
relevant OF specification.

> +
> +Action: ``IP_TTL_DEC``
> +^^^^^^^^^^^^^^^^^^^^^^
> +
> +Decrement IPv4 TTL or IPv6 hop limit field and update the IP checksum,
> +only applies to packets that contain specific MPLS headers.
> +
> +.. _table_rte_flow_action_ip_ttl_dec:
> +
> +.. table:: IP_TTL_DEC
> +
> +   +---------------+----------------------------------------------------------+
> +   | Field         | Value                                                    |
> +   +===============+==========================================================+
> +   | ``dir_level`` | Specify the level of IPv4 or IPv6 header.                |
> +   |               | direction (1b)                                           |
> +   |               | 0: match start from outermost.                           |
> +   |               | 1: match start from innermost.                           |
> +   |               | level: (31b)                                             |
> +   |               | 0: outermost or innermost Ipv4 or IPv6 header            |
> +   |               | 1: next to outmost or innermost MPLS IPv4 or IPv6 header |
> +   |               | 2: and so on ...                                         |
> +   +---------------+----------------------------------------------------------+

Ditto.

> +
> +Action: ``TTL_COPY_OUT``
> +^^^^^^^^^^^^^^^^^^^^^^^^
> +
> +Copy the TTL from next-to-outermost to outermost header with TTL, copy can
> +be IP to IP, MPLS to MPLS or IP to MPLS, only applies packets that contain
> +required MPLS or IP headers.
> +
> +.. _table_rte_flow_action_ttl_copy_out:
> +
> +.. table:: TTL_COPY_OUT
> +
> +   +---------------+
> +   | Field         |
> +   +===============+
> +   | no properties |
> +   +---------------+

Same comment as above re linking to OpenFlow.

> +
> +Action: ``TTL_COPY_IN``
> +^^^^^^^^^^^^^^^^^^^^^^^
> +
> +Copy the TTL from outermost to next-to-outermost header with TTL, copy can
> +be IP to IP, MPLS to MPLS or MPLS to IP, only applies packets that contain
> +required MPLS or IP headers.
> +
> +.. _table_rte_flow_action_ttl_copy_in:
> +
> +.. table:: TTL_COPY_IN
> +
> +   +---------------+
> +   | Field         |
> +   +===============+
> +   | no properties |
> +   +---------------+

Ditto.

> +
>  Negative types
>  ~~~~~~~~~~~~~~
>  
> diff --git a/doc/guides/testpmd_app_ug/testpmd_funcs.rst b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> index 12d78f10b..d2fe6637b 100644
> --- a/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> +++ b/doc/guides/testpmd_app_ug/testpmd_funcs.rst
> @@ -3449,6 +3449,18 @@ This section lists supported actions and their attributes, if any.
>    - ``original {boolean}``: use original VF ID if possible.
>    - ``id {unsigned}``: VF ID to redirect packets to.
>  
> +- ``mpls_ttl_dec``: decrement MPLS TTL.
> +
> +  - ``level``: level of MPLS header.
> +
> +- ``ip_ttl_dec``: decrement IPv4 TTL or IPv6 Hot Limit.
> +
> +  - ``level``: level of IPv4 or IPv6 header.
> +
> +- ``ttl_copy_out``: copy TTL outwards.
> +
> +- ``ttl_copy_in``: copy TTL inwards.

"level" must be removed from here also.

> +
>  Destroying flow rules
>  ~~~~~~~~~~~~~~~~~~~~~
>  
> diff --git a/lib/librte_ether/rte_flow.h b/lib/librte_ether/rte_flow.h
> index 2dc95b6b8..ab181cd83 100644
> --- a/lib/librte_ether/rte_flow.h
> +++ b/lib/librte_ether/rte_flow.h
> @@ -1254,6 +1254,37 @@ enum rte_flow_action_type {
>  	 * See struct rte_flow_action_field_set.
>  	 */
>  	RTE_FLOW_ACTION_TYPE_FIELD_SET,
> +
> +	/**
> +	 * Decrement MPLS TTL, only applies to packets that contain specific
> +	 * MPLS header.
> +	 *
> +	 * See struct rte_flow_action_mpls_ttl_dec.
> +	 */
> +	RTE_FLOW_ACTION_TYPE_MPLS_TTL_DEC,
> +
> +	/**
> +	 * Decrement IPv4 TTL or IPv6 Hop limit field and update the IP
> +	 * checksum, only applies to packets that contain specific IPv4
> +	 * or IPv6 header.
> +	 *
> +	 * See struct rte_flow_action_ip_ttl_dec.
> +	 */
> +	RTE_FLOW_ACTION_TYPE_IP_TTL_DEC,
> +
> +	/**
> +	 * Copy the TTL from next-to-outermost to outermost header with TTL,
> +	 * copy can be IP to IP, MPLS to MPLS or IP to MPLS, only applies
> +	 * packets that contain required protocol headers.

As for other actions, please add:

 No associated configuration structure.

> +	 */
> +	RTE_FLOW_ACTION_TYPE_TTL_COPY_OUT,
> +
> +	/**
> +	 * Copy the TTL from outermost to next-to-outermost header with TTL,
> +	 * copy can be IP to IP, MPLS to MPLS or MPLS to IP, only applies
> +	 * packets that contain required protocol headers.

Ditto.

> +	 */
> +	RTE_FLOW_ACTION_TYPE_TTL_COPY_IN,
>  };
>  
>  /**
> @@ -1424,6 +1455,52 @@ struct rte_flow_action_field_set {
>  };
>  
>  /**
> + * RTE_FLOW_ACTION_TYPE_MPLS_TTL_DEC
> + *
> + * Decrement MPLS TTL, only applies to packets that contain specific
> + * MPLS header.
> + */
> +struct rte_flow_action_mpls_ttl_dec {
> +	/**
> +	 * Specify the level of MPLS header.
> +	 *
> +	 * direction (1b)
> +	 * 0: match start from outermost.
> +	 * 1: match start from innermost.
> +	 *
> +	 * level (31b)
> +	 * 0: outermost|innermost MPLS header.
> +	 * 1: next to outermost|innermost MPLS header.
> +	 * 2: and so on ...
> +	 */
> +	uint32_t dir_level;
> +
> +};

As described above, this structure must be removed.

> +
> +/**
> + * RTE_FLOW_ACTION_TYPE_IP_TTL_DEC
> + *
> + * Decrement IPv4 TTL or IPv6 hop limit field and update the IP
> + * checksum, only applies to packets that contain specific IPv4
> + * or IPv6 header.
> + */
> +struct rte_flow_action_ip_ttl_dec {
> +	/**
> +	 * Specify the level of IPv4 or IPv6 header.
> +	 *
> +	 * direction (1b)
> +	 * 0: match start from outermost.
> +	 * 1: match start from innermost.
> +	 *
> +	 * level (31b)
> +	 * 0: outermost|innermost IPv4 or IPv6 header.
> +	 * 1: next to outermost|innermost IPv4 or IPv6 header.
> +	 * 2: and so on ...
> +	 */
> +	uint32_t dir_level;
> +};

Ditto.

> +
> +/**
>   * Definition of a single action.
>   *
>   * A list of actions is terminated by a END action.
> -- 
> 2.13.6
> 

-- 
Adrien Mazarguil
6WIND