[PATCH v6 12/21] pdcp: add control PDU handling for status report

[Anoob Joseph <anoobj@marvell.com>]

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>
---
 doc/guides/prog_guide/pdcp_lib.rst |  9 ++++++
 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                | 33 +++++++++++++++++++++
 lib/pdcp/version.map               |  2 ++
 11 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/doc/guides/prog_guide/pdcp_lib.rst b/doc/guides/prog_guide/pdcp_lib.rst
index 2eefabf45c..a925aa7f14 100644
--- a/doc/guides/prog_guide/pdcp_lib.rst
+++ b/doc/guides/prog_guide/pdcp_lib.rst
@@ -76,6 +76,15 @@ 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 as
+re-establishment, receiving PDCP entity need to prepare a status report and
+send it to the other end. The API ``rte_pdcp_control_pdu_create()`` allows
+application to request the same.
+
 PDCP packet processing API for data PDU
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
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_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 10a72faae1..28691a504b 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;
+};
+
 /*
  * 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 *ctrl_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 28ac4102da..ed1413db6d 100644
--- a/lib/pdcp/pdcp_process.c
+++ b/lib/pdcp/pdcp_process.c
@@ -1092,6 +1092,19 @@ 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 91dab91f73..96ad397667 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"
 
@@ -58,7 +60,7 @@ rte_pdcp_entity_establish(const struct rte_pdcp_entity_conf *conf)
 	if (pdcp_dynfield_register() < 0)
 		return NULL;
 
-	if (conf == NULL || conf->cop_pool == NULL) {
+	if (conf == NULL || conf->cop_pool == NULL || conf->ctrl_pdu_pool == NULL) {
 		rte_errno = EINVAL;
 		return NULL;
 	}
@@ -105,6 +107,7 @@ rte_pdcp_entity_establish(const struct rte_pdcp_entity_conf *conf)
 	en_priv->state.rx_deliv = count;
 	en_priv->state.tx_next = count;
 	en_priv->cop_pool = conf->cop_pool;
+	en_priv->ctrl_pdu_pool = conf->ctrl_pdu_pool;
 
 	/* Setup crypto session */
 	ret = pdcp_crypto_sess_create(entity, conf);
@@ -115,6 +118,10 @@ 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:
@@ -162,3 +169,41 @@ 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;
+		return NULL;
+	}
+
+	en_priv = entity_priv_get(pdcp_entity);
+
+	m = rte_pktmbuf_alloc(en_priv->ctrl_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 e63946aa08..d7c2080358 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
@@ -80,6 +81,8 @@ 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 *ctrl_pdu_pool;
 	/**
 	 * Sequence number value to be used.
 	 * 32 bit count value to be used for the first packet
@@ -97,6 +100,16 @@ struct rte_pdcp_entity_conf {
 	 * 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_control_pdu_create``.
+	 * In addition, PDCP status reports may be generated during operations
+	 * such as entity re-establishment.
+	 */
+	bool status_report_required;
 };
 /* >8 End of structure rte_pdcp_entity_conf. */
 
@@ -178,6 +191,26 @@ 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. The control PDU packet
+ * would be allocated from *rte_pdcp_entity_conf.ctrl_pdu_pool* by lib PDCP.
+ *
+ * @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 d564f155e0..97171f902e 100644
--- a/lib/pdcp/version.map
+++ b/lib/pdcp/version.map
@@ -2,6 +2,8 @@ EXPERIMENTAL {
 	global:
 
 	# added in 23.07
+	rte_pdcp_control_pdu_create;
+
 	rte_pdcp_en_from_cop;
 
 	rte_pdcp_entity_establish;
-- 
2.25.1