RE: [PATCH v2 12/22] pdcp: add control PDU handling

[Akhil Goyal <gakhil@marvell.com>]

> Subject: [PATCH v2 12/22] pdcp: add control PDU handling
> 
> Add control PDU handling and implement status report generation. Status
> report generation works only when RX_DELIV = RX_NEXT.
> 
> Signed-off-by: Anoob Joseph <anoobj@marvell.com>
> Signed-off-by: Volodymyr Fialko <vfialko@marvell.com>
> ---
>  app/test/test_pdcp.c               |  1 +

Separate out test app changes from library changes.

>  doc/guides/prog_guide/pdcp_lib.rst | 10 +++++++
>  lib/pdcp/meson.build               |  2 ++
>  lib/pdcp/pdcp_cnt.c                | 29 ++++++++++++++++++
>  lib/pdcp/pdcp_cnt.h                | 14 +++++++++
>  lib/pdcp/pdcp_ctrl_pdu.c           | 46 +++++++++++++++++++++++++++++
>  lib/pdcp/pdcp_ctrl_pdu.h           | 15 ++++++++++
>  lib/pdcp/pdcp_entity.h             | 15 ++++++++--
>  lib/pdcp/pdcp_process.c            | 13 +++++++++
>  lib/pdcp/rte_pdcp.c                | 47 +++++++++++++++++++++++++++++-
>  lib/pdcp/rte_pdcp.h                | 31 ++++++++++++++++++++
>  lib/pdcp/version.map               |  2 ++
>  12 files changed, 222 insertions(+), 3 deletions(-)
>  create mode 100644 lib/pdcp/pdcp_cnt.c
>  create mode 100644 lib/pdcp/pdcp_cnt.h
>  create mode 100644 lib/pdcp/pdcp_ctrl_pdu.c
>  create mode 100644 lib/pdcp/pdcp_ctrl_pdu.h
> 
> diff --git a/app/test/test_pdcp.c b/app/test/test_pdcp.c
> index fc49947ba2..4ecb4d9572 100644
> --- a/app/test/test_pdcp.c
> +++ b/app/test/test_pdcp.c
> @@ -415,6 +415,7 @@ create_test_conf_from_index(const int index, struct
> pdcp_test_conf *conf)
> 
>  	conf->entity.sess_mpool = ts_params->sess_pool;
>  	conf->entity.cop_pool = ts_params->cop_pool;
> +	conf->entity.ctr_pdu_pool = ts_params->mbuf_pool;
>  	conf->entity.pdcp_xfrm.bearer = pdcp_test_bearer[index];
>  	conf->entity.pdcp_xfrm.en_ordering = 0;
>  	conf->entity.pdcp_xfrm.remove_duplicates = 0;
> diff --git a/doc/guides/prog_guide/pdcp_lib.rst
> b/doc/guides/prog_guide/pdcp_lib.rst
> index abd874f2cc..f23360dfc3 100644
> --- a/doc/guides/prog_guide/pdcp_lib.rst
> +++ b/doc/guides/prog_guide/pdcp_lib.rst
> @@ -67,6 +67,15 @@ Data PDUs are regular packets submitted by upper layers
> for transmission to
>  other end. Such packets would need to be ciphered and authenticated based on
>  the entity configuration.
> 
> +PDCP packet processing API for control PDU
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +Control PDUs are used in PDCP as a communication channel between
> transmitting
> +and receiving entities. When upper layer request for operations such
> +re-establishment, receiving PDCP entity need to prepare a status report and
> +send it to the other end. The API ``pdcp_ctrl_pdu_status_gen`` allows
> +application to request the same.

pdcp_ctrl_pdu_status_gen() - Is this a user visible API? I believe it is not exposed.
How can application request that?


> +
>  PDCP packet processing API for data PDU
>  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> @@ -228,6 +237,7 @@ Supported features
>  - Uplink & downlink traffic
>  - HFN increment
>  - IV generation as required per algorithm
> +- Control PDU generation
> 
>  Supported ciphering algorithms
>  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> diff --git a/lib/pdcp/meson.build b/lib/pdcp/meson.build
> index 08679b743a..75d476bf6d 100644
> --- a/lib/pdcp/meson.build
> +++ b/lib/pdcp/meson.build
> @@ -8,7 +8,9 @@ if is_windows
>  endif
> 
>  sources = files(
> +        'pdcp_cnt.c',

pdcp_cnt seems to be something related to count.
And it is not related to this patch probably.

>          'pdcp_crypto.c',
> +        'pdcp_ctrl_pdu.c',
>          'pdcp_process.c',
>          'rte_pdcp.c',
>          )
> diff --git a/lib/pdcp/pdcp_cnt.c b/lib/pdcp/pdcp_cnt.c
> new file mode 100644
> index 0000000000..c9b952184b
> --- /dev/null
> +++ b/lib/pdcp/pdcp_cnt.c
> @@ -0,0 +1,29 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(C) 2023 Marvell.
> + */
> +
> +#include <rte_pdcp.h>
> +
> +#include "pdcp_cnt.h"
> +#include "pdcp_entity.h"
> +
> +int
> +pdcp_cnt_ring_create(struct rte_pdcp_entity *en, const struct
> rte_pdcp_entity_conf *conf)
> +{
> +	struct entity_priv_dl_part *en_priv_dl;
> +	uint32_t window_sz;
> +
> +	if (en == NULL || conf == NULL)
> +		return -EINVAL;
> +
> +	if (conf->pdcp_xfrm.pkt_dir == RTE_SECURITY_PDCP_UPLINK)
> +		return 0;
> +
> +	en_priv_dl = entity_dl_part_get(en);
> +	window_sz = pdcp_window_size_get(conf->pdcp_xfrm.sn_size);
> +
> +	RTE_SET_USED(window_sz);
> +	RTE_SET_USED(en_priv_dl);
> +
> +	return 0;
> +}
> diff --git a/lib/pdcp/pdcp_cnt.h b/lib/pdcp/pdcp_cnt.h
> new file mode 100644
> index 0000000000..bbda478b55
> --- /dev/null
> +++ b/lib/pdcp/pdcp_cnt.h
> @@ -0,0 +1,14 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(C) 2023 Marvell.
> + */
> +
> +#ifndef PDCP_CNT_H
> +#define PDCP_CNT_H
> +
> +#include <rte_common.h>
> +
> +#include "pdcp_entity.h"
> +
> +int pdcp_cnt_ring_create(struct rte_pdcp_entity *en, const struct
> rte_pdcp_entity_conf *conf);
> +
> +#endif /* PDCP_CNT_H */
> diff --git a/lib/pdcp/pdcp_ctrl_pdu.c b/lib/pdcp/pdcp_ctrl_pdu.c
> new file mode 100644
> index 0000000000..feb05fd863
> --- /dev/null
> +++ b/lib/pdcp/pdcp_ctrl_pdu.c
> @@ -0,0 +1,46 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(C) 2023 Marvell.
> + */
> +
> +#include <rte_byteorder.h>
> +#include <rte_mbuf.h>
> +#include <rte_pdcp_hdr.h>
> +
> +#include "pdcp_ctrl_pdu.h"
> +#include "pdcp_entity.h"
> +
> +static __rte_always_inline void
> +pdcp_hdr_fill(struct rte_pdcp_up_ctrl_pdu_hdr *pdu_hdr, uint32_t rx_deliv)
> +{
> +	pdu_hdr->d_c = RTE_PDCP_PDU_TYPE_CTRL;
> +	pdu_hdr->pdu_type = RTE_PDCP_CTRL_PDU_TYPE_STATUS_REPORT;
> +	pdu_hdr->r = 0;
> +	pdu_hdr->fmc = rte_cpu_to_be_32(rx_deliv);
> +}
> +
> +int
> +pdcp_ctrl_pdu_status_gen(struct entity_priv *en_priv, struct rte_mbuf *m)
> +{
> +	struct rte_pdcp_up_ctrl_pdu_hdr *pdu_hdr;
> +	uint32_t rx_deliv;
> +	int pdu_sz;
> +
> +	if (!en_priv->flags.is_status_report_required)
> +		return -EINVAL;
> +
> +	pdu_sz = sizeof(struct rte_pdcp_up_ctrl_pdu_hdr);
> +
> +	rx_deliv = en_priv->state.rx_deliv;
> +
> +	/* Zero missing PDUs - status report contains only FMC */
> +	if (rx_deliv >= en_priv->state.rx_next) {
> +		pdu_hdr = (struct rte_pdcp_up_ctrl_pdu_hdr
> *)rte_pktmbuf_append(m, pdu_sz);
> +		if (pdu_hdr == NULL)
> +			return -ENOMEM;
> +		pdcp_hdr_fill(pdu_hdr, rx_deliv);
> +
> +		return 0;
> +	}
> +
> +	return -ENOTSUP;
> +}
> diff --git a/lib/pdcp/pdcp_ctrl_pdu.h b/lib/pdcp/pdcp_ctrl_pdu.h
> new file mode 100644
> index 0000000000..a2424fbd10
> --- /dev/null
> +++ b/lib/pdcp/pdcp_ctrl_pdu.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(C) 2023 Marvell.
> + */
> +
> +#ifndef PDCP_CTRL_PDU_H
> +#define PDCP_CTRL_PDU_H
> +
> +#include <rte_mbuf.h>
> +
> +#include "pdcp_entity.h"
> +
> +int
> +pdcp_ctrl_pdu_status_gen(struct entity_priv *en_priv, struct rte_mbuf *m);
> +
> +#endif /* PDCP_CTRL_PDU_H */
> diff --git a/lib/pdcp/pdcp_entity.h b/lib/pdcp/pdcp_entity.h
> index 3108795977..7b7e7f69dd 100644
> --- a/lib/pdcp/pdcp_entity.h
> +++ b/lib/pdcp/pdcp_entity.h
> @@ -109,6 +109,13 @@ union cipher_iv_partial {
>  	uint64_t u64[2];
>  };
> 
> +struct pdcp_cnt_bitmap {
> +	/** Number of entries that can be stored. */
> +	uint32_t size;
> +	/** Bitmap of the count values already received.*/
> +	struct rte_bitmap *bmp;
> +};

This pdcp_cnt_bitmap is not related to control PDU. Right?
I believe the patch split is not proper here.

> +
>  /*
>   * Layout of PDCP entity: [rte_pdcp_entity] [entity_priv] [entity_dl/ul]
>   */
> @@ -136,9 +143,13 @@ struct entity_priv {
>  		uint64_t is_ul_entity : 1;
>  		/** Is NULL auth. */
>  		uint64_t is_null_auth : 1;
> +		/** Is status report required.*/
> +		uint64_t is_status_report_required : 1;
>  	} flags;
>  	/** Crypto op pool. */
>  	struct rte_mempool *cop_pool;
> +	/** Control PDU pool. */
> +	struct rte_mempool *ctr_pdu_pool;
>  	/** PDCP header size. */
>  	uint8_t hdr_sz;
>  	/** PDCP AAD size. For AES-CMAC, additional message is prepended for
> the operation. */
> @@ -148,8 +159,8 @@ struct entity_priv {
>  };
> 
>  struct entity_priv_dl_part {
> -	/* NOTE: when in-order-delivery is supported, post PDCP packets would
> need to cached. */
> -	uint8_t dummy;
> +	/** PDCP would need to track the count values that are already
> received.*/
> +	struct pdcp_cnt_bitmap bitmap;
>  };
> 
>  struct entity_priv_ul_part {
> diff --git a/lib/pdcp/pdcp_process.c b/lib/pdcp/pdcp_process.c
> index 9c1a5e0669..267b3b7723 100644
> --- a/lib/pdcp/pdcp_process.c
> +++ b/lib/pdcp/pdcp_process.c
> @@ -1157,6 +1157,19 @@ pdcp_entity_priv_populate(struct entity_priv
> *en_priv, const struct rte_pdcp_ent
>  	if (a_xfrm != NULL && a_xfrm->auth.algo ==
> RTE_CRYPTO_AUTH_NULL)
>  		en_priv->flags.is_null_auth = 1;
> 
> +	/**
> +	 * flags.is_status_report_required
> +	 *
> +	 * Indicate whether status report is required.
> +	 */
> +	if (conf->status_report_required) {
> +		/** Status report is required only for DL entities. */
> +		if (conf->pdcp_xfrm.pkt_dir !=
> RTE_SECURITY_PDCP_DOWNLINK)
> +			return -EINVAL;
> +
> +		en_priv->flags.is_status_report_required = 1;
> +	}
> +
>  	/**
>  	 * hdr_sz
>  	 *
> diff --git a/lib/pdcp/rte_pdcp.c b/lib/pdcp/rte_pdcp.c
> index 8914548dbd..5cd3f5ca31 100644
> --- a/lib/pdcp/rte_pdcp.c
> +++ b/lib/pdcp/rte_pdcp.c
> @@ -6,7 +6,9 @@
>  #include <rte_pdcp.h>
>  #include <rte_malloc.h>
> 
> +#include "pdcp_cnt.h"
>  #include "pdcp_crypto.h"
> +#include "pdcp_ctrl_pdu.h"
>  #include "pdcp_entity.h"
>  #include "pdcp_process.h"
> 
> @@ -34,7 +36,7 @@ rte_pdcp_entity_establish(const struct
> rte_pdcp_entity_conf *conf)
>  	struct entity_priv *en_priv;
>  	int ret, entity_size;
> 
> -	if (conf == NULL || conf->cop_pool == NULL) {
> +	if (conf == NULL || conf->cop_pool == NULL || conf->ctr_pdu_pool ==
> NULL) {
>  		rte_errno = -EINVAL;
>  		return NULL;
>  	}
> @@ -79,6 +81,7 @@ rte_pdcp_entity_establish(const struct
> rte_pdcp_entity_conf *conf)
>  	en_priv->state.rx_deliv = conf->count;
>  	en_priv->state.tx_next = conf->count;
>  	en_priv->cop_pool = conf->cop_pool;
> +	en_priv->ctr_pdu_pool = conf->ctr_pdu_pool;
> 
>  	/* Setup crypto session */
>  	ret = pdcp_crypto_sess_create(entity, conf);
> @@ -89,6 +92,10 @@ rte_pdcp_entity_establish(const struct
> rte_pdcp_entity_conf *conf)
>  	if (ret)
>  		goto crypto_sess_destroy;
> 
> +	ret = pdcp_cnt_ring_create(entity, conf);
> +	if (ret)
> +		goto crypto_sess_destroy;
> +
>  	return entity;
> 
>  crypto_sess_destroy:
> @@ -136,3 +143,41 @@ rte_pdcp_entity_suspend(struct rte_pdcp_entity
> *pdcp_entity,
> 
>  	return 0;
>  }
> +
> +struct rte_mbuf *
> +rte_pdcp_control_pdu_create(struct rte_pdcp_entity *pdcp_entity,
> +			    enum rte_pdcp_ctrl_pdu_type type)
> +{
> +	struct entity_priv *en_priv;
> +	struct rte_mbuf *m;
> +	int ret;
> +
> +	if (pdcp_entity == NULL) {
> +		rte_errno = -EINVAL;

rte_errno should be positive values.

> +		return NULL;
> +	}
> +
> +	en_priv = entity_priv_get(pdcp_entity);
> +
> +	m = rte_pktmbuf_alloc(en_priv->ctr_pdu_pool);
> +	if (m == NULL) {
> +		rte_errno = -ENOMEM;
> +		return NULL;
> +	}
> +
> +	switch (type) {
> +	case RTE_PDCP_CTRL_PDU_TYPE_STATUS_REPORT:
> +		ret = pdcp_ctrl_pdu_status_gen(en_priv, m);
> +		break;
> +	default:
> +		ret = -ENOTSUP;
> +	}
> +
> +	if (ret) {
> +		rte_pktmbuf_free(m);
> +		rte_errno = ret;
> +		return NULL;
> +	}
> +
> +	return m;
> +}
> diff --git a/lib/pdcp/rte_pdcp.h b/lib/pdcp/rte_pdcp.h
> index 54f88e3fd3..d2db25d7d9 100644
> --- a/lib/pdcp/rte_pdcp.h
> +++ b/lib/pdcp/rte_pdcp.h
> @@ -16,6 +16,7 @@
>  #include <rte_compat.h>
>  #include <rte_common.h>
>  #include <rte_mempool.h>
> +#include <rte_pdcp_hdr.h>
>  #include <rte_security.h>
> 
>  #ifdef __cplusplus
> @@ -78,6 +79,8 @@ struct rte_pdcp_entity_conf {
>  	struct rte_mempool *sess_mpool;
>  	/** Crypto op pool.*/
>  	struct rte_mempool *cop_pool;
> +	/** Mbuf pool to be used for allocating control PDUs.*/
> +	struct rte_mempool *ctr_pdu_pool;

Please use same prefix for all control pdu stuff.
I see cnt, ctr, ctrl, control is being used.
I think "control" for top level API and "ctrl" for parameters should be fine.

>  	/**
>  	 * 32 bit count value (HFN + SN) to be used for the first packet.
>  	 * pdcp_xfrm.hfn would be ignored as the HFN would be derived from
> this value.
> @@ -91,6 +94,15 @@ struct rte_pdcp_entity_conf {
>  	uint8_t dev_id;
>  	/** Reverse direction during IV generation. Can be used to simulate UE
> crypto processing.*/
>  	bool reverse_iv_direction;
> +	/**
> +	 * Status report required (specified in TS 38.331).
> +	 *
> +	 * If PDCP entity is configured to send a PDCP status report, the upper
> layer application
> +	 * may request a receiving PDCP entity to generate a PDCP status report
> using
> +	 * ``rte_pdcp_ctrl_pdu_create``. In addition, PDCP status reports may be
> generated during
> +	 * operations such as entity re-establishment.
> +	 */
> +	bool status_report_required;

rte_pdcp_ctrl_pdu_create -> rte_pdcp_control_pdu_create

Please specify that a PDU will be generated for status report.
Otherwise, it seems some structure would be returned for status report
But there is no mention of that. This will avoid confusion.


>  };
>  /* >8 End of structure rte_pdcp_entity_conf. */
> 
> @@ -169,6 +181,25 @@ int
>  rte_pdcp_entity_suspend(struct rte_pdcp_entity *pdcp_entity,
>  			struct rte_mbuf *out_mb[]);
> 
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice
> + *
> + * Create control PDU packet of the `type` specified.
> + *
> + * @param pdcp_entity
> + *   Pointer to the PDCP entity for which the control PDU need to be generated.
> + * @param type
> + *   Type of control PDU to be generated.
> + * @return
> + *   - Control PDU generated, in case of success.
> + *   - NULL in case of failure. rte_errno will be set to error code.
> + */
> +__rte_experimental
> +struct rte_mbuf *
> +rte_pdcp_control_pdu_create(struct rte_pdcp_entity *pdcp_entity,
> +			    enum rte_pdcp_ctrl_pdu_type type);
> +
>  /**
>   * @warning
>   * @b EXPERIMENTAL: this API may change without prior notice
> diff --git a/lib/pdcp/version.map b/lib/pdcp/version.map
> index f9ff30600a..d0cf338e1f 100644
> --- a/lib/pdcp/version.map
> +++ b/lib/pdcp/version.map
> @@ -6,6 +6,8 @@ EXPERIMENTAL {
>  	rte_pdcp_entity_release;
>  	rte_pdcp_entity_suspend;
> 
> +	rte_pdcp_control_pdu_create;
> +
>  	rte_pdcp_pkt_post_process;
>  	rte_pdcp_pkt_pre_process;
> 
> --
> 2.25.1