/*
 * Copyright (c) 2016 Intel Corporation.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @file
 * @brief IEEE 802.15.4 MAC frame related functions
 *
 * @details This is not to be included by the application.
 *
 * @note All references to the standard in this file cite IEEE 802.15.4-2020.
 *
 * @note All structs and attributes (e.g. PAN id, ext address and short address)
 * in this file that directly represent parts of IEEE 802.15.4 frames are in
 * LITTLE ENDIAN, see section 4, especially section 4.3.
 */

#ifndef __IEEE802154_FRAME_H__
#define __IEEE802154_FRAME_H__

#include <zephyr/kernel.h>
#include <zephyr/net/ieee802154.h>
#include <zephyr/net/net_pkt.h>
#include <zephyr/toolchain.h>

#define IEEE802154_ACK_PKT_LENGTH 3 /* Imm-Ack length, see section 7.3.3 */
#define IEEE802154_MIN_LENGTH	  IEEE802154_ACK_PKT_LENGTH

#define IEEE802154_FCF_SEQ_LENGTH     3
#define IEEE802154_PAN_ID_LENGTH      2

#define IEEE802154_BEACON_MIN_SIZE	  4
#define IEEE802154_BEACON_SF_SIZE	  2
#define IEEE802154_BEACON_GTS_SPEC_SIZE	  1
#define IEEE802154_BEACON_GTS_IF_MIN_SIZE IEEE802154_BEACON_GTS_SPEC_SIZE
#define IEEE802154_BEACON_PAS_SPEC_SIZE	  1
#define IEEE802154_BEACON_PAS_IF_MIN_SIZE IEEE802154_BEACON_PAS_SPEC_SIZE
#define IEEE802154_BEACON_GTS_DIR_SIZE	  1
#define IEEE802154_BEACON_GTS_SIZE	  3
#define IEEE802154_BEACON_GTS_RX	  1
#define IEEE802154_BEACON_GTS_TX	  0

/** see section 7.2.2.2 */
enum ieee802154_frame_type {
	IEEE802154_FRAME_TYPE_BEACON = 0x0,
	IEEE802154_FRAME_TYPE_DATA = 0x1,
	IEEE802154_FRAME_TYPE_ACK = 0x2,
	IEEE802154_FRAME_TYPE_MAC_COMMAND = 0x3,
	IEEE802154_FRAME_TYPE_RESERVED = 0x4,
	IEEE802154_FRAME_TYPE_MULTIPURPOSE = 0x5,
	IEEE802154_FRAME_TYPE_FRAK = 0x6,
	IEEE802154_FRAME_TYPE_EXTENDED = 0x7,
};

/** see section 7.2.2.9, table 7-3 */
enum ieee802154_addressing_mode {
	IEEE802154_ADDR_MODE_NONE = 0x0,
	IEEE802154_ADDR_MODE_RESERVED = 0x1,
	IEEE802154_ADDR_MODE_SHORT = 0x2,
	IEEE802154_ADDR_MODE_EXTENDED = 0x3,
};

/** see section 7.2.2.10 */
enum ieee802154_version {
	IEEE802154_VERSION_802154_2003 = 0x0,
	IEEE802154_VERSION_802154_2006 = 0x1,
	IEEE802154_VERSION_802154 = 0x2,
	IEEE802154_VERSION_RESERVED = 0x3,
};

/** Frame Control Field, see section 7.2.2 */
struct ieee802154_fcf_seq {
	struct {
#ifdef CONFIG_LITTLE_ENDIAN
		uint16_t frame_type : 3;
		uint16_t security_enabled : 1;
		uint16_t frame_pending : 1;
		uint16_t ar : 1;
		uint16_t pan_id_comp : 1;
		uint16_t reserved : 1;
		uint16_t seq_num_suppr : 1;
		uint16_t ie_list : 1;
		uint16_t dst_addr_mode : 2;
		uint16_t frame_version : 2;
		uint16_t src_addr_mode : 2;
#else
		uint16_t reserved : 1;
		uint16_t pan_id_comp : 1;
		uint16_t ar : 1;
		uint16_t frame_pending : 1;
		uint16_t security_enabled : 1;
		uint16_t frame_type : 3;
		uint16_t src_addr_mode : 2;
		uint16_t frame_version : 2;
		uint16_t dst_addr_mode : 2;
		uint16_t ie_list : 1;
		uint16_t seq_num_suppr : 1;
#endif
	} fc __packed;

	uint8_t sequence;
} __packed;

struct ieee802154_address {
	union {
		uint16_t short_addr;
		uint8_t ext_addr[0];
	};
} __packed;

struct ieee802154_address_field_comp {
	struct ieee802154_address addr;
} __packed;

struct ieee802154_address_field_plain {
	uint16_t pan_id;
	struct ieee802154_address addr;
} __packed;

struct ieee802154_address_field {
	union {
		struct ieee802154_address_field_plain plain;
		struct ieee802154_address_field_comp comp;
	};
} __packed;

/** see section 9.4.2.2, table 9-6 */
enum ieee802154_security_level {
	IEEE802154_SECURITY_LEVEL_NONE = 0x0,
	IEEE802154_SECURITY_LEVEL_MIC_32 = 0x1,
	IEEE802154_SECURITY_LEVEL_MIC_64 = 0x2,
	IEEE802154_SECURITY_LEVEL_MIC_128 = 0x3,
	IEEE802154_SECURITY_LEVEL_RESERVED = 0x4,
	IEEE802154_SECURITY_LEVEL_ENC_MIC_32 = 0x5,
	IEEE802154_SECURITY_LEVEL_ENC_MIC_64 = 0x6,
	IEEE802154_SECURITY_LEVEL_ENC_MIC_128 = 0x7,
};

/** Levels above this level will be encrypted. */
#define IEEE802154_SECURITY_LEVEL_ENC IEEE802154_SECURITY_LEVEL_RESERVED

/** This will match above *_MIC_<32/64/128> */
#define IEEE802154_AUTH_TAG_LENGTH_32  4
#define IEEE802154_AUTH_TAG_LENGTH_64  8
#define IEEE802154_AUTH_TAG_LENGTH_128 16

/** see section 9.4.2.3, table 9-7 */
enum ieee802154_key_id_mode {
	IEEE802154_KEY_ID_MODE_IMPLICIT = 0x0,
	IEEE802154_KEY_ID_MODE_INDEX = 0x1,
	IEEE802154_KEY_ID_MODE_SRC_4_INDEX = 0x2,
	IEEE802154_KEY_ID_MODE_SRC_8_INDEX = 0x3,
};

#define IEEE802154_KEY_ID_FIELD_INDEX_LENGTH	   1
#define IEEE802154_KEY_ID_FIELD_SRC_4_INDEX_LENGTH 5
#define IEEE802154_KEY_ID_FIELD_SRC_8_INDEX_LENGTH 9

#define IEEE802154_KEY_MAX_LEN 16

/** see section 9.4.2 */
struct ieee802154_security_control_field {
#ifdef CONFIG_LITTLE_ENDIAN
	uint8_t security_level : 3;
	uint8_t key_id_mode : 2;
	uint8_t reserved : 3;
#else
	uint8_t reserved : 3;
	uint8_t key_id_mode : 2;
	uint8_t security_level : 3;
#endif
} __packed;

#define IEEE802154_SECURITY_CF_LENGTH 1

/**
 * @brief see section 9.4.4
 *
 * @note Currently only mode 0 is supported, so this structure holds no info,
 * yet.
 */
struct ieee802154_key_identifier_field {
	union {
		struct {
			uint8_t key_index;
		} mode_1;

		struct {
			uint8_t key_src[4];
			uint8_t key_index;
		} mode_2;

		struct {
			uint8_t key_src[8];
			uint8_t key_index;
		} mode_3;
	};
} __packed;

/** Auxiliary Security Header, see section 9.4 */
struct ieee802154_aux_security_hdr {
	struct ieee802154_security_control_field control;
	uint32_t frame_counter;
	struct ieee802154_key_identifier_field kif;
} __packed;

#define IEEE802154_SECURITY_FRAME_COUNTER_LENGTH 4

/** MAC header and footer, see section 7.2.1 */
struct ieee802154_mhr {
	struct ieee802154_fcf_seq *fs;
	struct ieee802154_address_field *dst_addr;
	struct ieee802154_address_field *src_addr;
#ifdef CONFIG_NET_L2_IEEE802154_SECURITY
	struct ieee802154_aux_security_hdr *aux_sec;
#endif
};

/** see section 7.3.1.5, figure 7-10 */
struct ieee802154_gts_dir {
#ifdef CONFIG_LITTLE_ENDIAN
	uint8_t mask : 7;
	uint8_t reserved : 1;
#else
	uint8_t reserved : 1;
	uint8_t mask : 7;
#endif
} __packed;

/** see section 7.3.1.5, figure 7-11 */
struct ieee802154_gts {
	uint16_t short_address;
#ifdef CONFIG_LITTLE_ENDIAN
	uint8_t starting_slot : 4;
	uint8_t length : 4;
#else
	uint8_t length : 4;
	uint8_t starting_slot : 4;
#endif
} __packed;

/** see section 7.3.1.5, figure 7-9 */
struct ieee802154_gts_spec {
#ifdef CONFIG_LITTLE_ENDIAN
	/* Descriptor Count */
	uint8_t desc_count : 3;
	uint8_t reserved : 4;
	/* GTS Permit */
	uint8_t permit : 1;
#else
	/* GTS Permit */
	uint8_t permit : 1;
	uint8_t reserved : 4;
	/* Descriptor Count */
	uint8_t desc_count : 3;
#endif
} __packed;

/** see section 7.3.1.6, figure 7-13 */
struct ieee802154_pas_spec {
#ifdef CONFIG_LITTLE_ENDIAN
	/* Number of Short Addresses Pending */
	uint8_t nb_sap : 3;
	uint8_t reserved_1 : 1;
	/* Number of Extended Addresses Pending */
	uint8_t nb_eap : 3;
	uint8_t reserved_2 : 1;
#else
	uint8_t reserved_1 : 1;
	/* Number of Extended Addresses Pending */
	uint8_t nb_eap : 3;
	uint8_t reserved_2 : 1;
	/* Number of Short Addresses Pending */
	uint8_t nb_sap : 3;
#endif
} __packed;

/** see section 7.3.1.4, figure 7-7 */
struct ieee802154_beacon_sf {
#ifdef CONFIG_LITTLE_ENDIAN
	/* Beacon Order*/
	uint16_t bc_order : 4;
	/* Superframe Order*/
	uint16_t sf_order : 4;
	/* Final CAP Slot */
	uint16_t cap_slot : 4;
	/* Battery Life Extension */
	uint16_t ble : 1;
	uint16_t reserved : 1;
	/* PAN Coordinator */
	uint16_t coordinator : 1;
	/* Association Permit */
	uint16_t association : 1;
#else
	/* Superframe Order*/
	uint16_t sf_order : 4;
	/* Beacon Order*/
	uint16_t bc_order : 4;
	/* Association Permit */
	uint16_t association : 1;
	/* PAN Coordinator */
	uint16_t coordinator : 1;
	uint16_t reserved : 1;
	/* Battery Life Extension */
	uint16_t ble : 1;
	/* Final CAP Slot */
	uint16_t cap_slot : 4;
#endif
} __packed;

/** see section 7.3.1.1, figure 7-5 */
struct ieee802154_beacon {
	struct ieee802154_beacon_sf sf;

	/* GTS Fields - Spec is always there */
	struct ieee802154_gts_spec gts;
} __packed;

/** See section 7.5.2 */
struct ieee802154_cmd_assoc_req {
	struct {
#ifdef CONFIG_LITTLE_ENDIAN
		uint8_t reserved_1 : 1;
		uint8_t dev_type : 1;
		uint8_t power_src : 1;
		uint8_t rx_on : 1;
		uint8_t association_type : 1;
		uint8_t reserved_2 : 1;
		uint8_t sec_capability : 1;
		uint8_t alloc_addr : 1;
#else
		uint8_t alloc_addr : 1;
		uint8_t sec_capability : 1;
		uint8_t reserved_2 : 1;
		uint8_t association_type : 1;
		uint8_t rx_on : 1;
		uint8_t power_src : 1;
		uint8_t dev_type : 1;
		uint8_t reserved_1 : 1;
#endif
	} ci;
} __packed;

#define IEEE802154_CMD_ASSOC_REQ_LENGTH 1

/** see section 7.5.3 */
enum ieee802154_association_status_field {
	IEEE802154_ASF_SUCCESSFUL = 0x00,
	IEEE802154_ASF_PAN_AT_CAPACITY = 0x01,
	IEEE802154_ASF_PAN_ACCESS_DENIED = 0x02,
	IEEE802154_ASF_RESERVED = 0x03,
	IEEE802154_ASF_RESERVED_PRIMITIVES = 0x80,
};

struct ieee802154_cmd_assoc_res {
	uint16_t short_addr;
	uint8_t status;
} __packed;

#define IEEE802154_CMD_ASSOC_RES_LENGTH 3

/** see section 7.5.4 */
enum ieee802154_disassociation_reason_field {
	IEEE802154_DRF_RESERVED_1 = 0x00,
	IEEE802154_DRF_COORDINATOR_WISH = 0x01,
	IEEE802154_DRF_DEVICE_WISH = 0x02,
	IEEE802154_DRF_RESERVED_2 = 0x03,
	IEEE802154_DRF_RESERVED_PRIMITIVES = 0x80,
};

struct ieee802154_cmd_disassoc_note {
	uint8_t reason;
} __packed;

#define IEEE802154_CMD_DISASSOC_NOTE_LENGTH 1

/** Coordinator realignment, see section 7.5.10 */
struct ieee802154_cmd_coord_realign {
	uint16_t pan_id;
	uint16_t coordinator_short_addr;
	uint8_t channel;
	uint16_t short_addr;
	uint8_t channel_page; /* optional */
} __packed;

#define IEEE802154_CMD_COORD_REALIGN_LENGTH 3

/** GTS request, see section 7.5.11 */
struct ieee802154_gts_request {
	struct {
#ifdef CONFIG_LITTLE_ENDIAN
		uint8_t length : 4;
		uint8_t direction : 1;
		uint8_t type : 1;
		uint8_t reserved : 2;
#else
		uint8_t reserved : 2;
		uint8_t type : 1;
		uint8_t direction : 1;
		uint8_t length : 4;
#endif
	} gts;
} __packed;

#define IEEE802154_GTS_REQUEST_LENGTH 1

/** Command Frame Identifiers (CFI), see section 7.5.1 */
enum ieee802154_cfi {
	IEEE802154_CFI_UNKNOWN = 0x00,
	IEEE802154_CFI_ASSOCIATION_REQUEST = 0x01,
	IEEE802154_CFI_ASSOCIATION_RESPONSE = 0x02,
	IEEE802154_CFI_DISASSOCIATION_NOTIFICATION = 0x03,
	IEEE802154_CFI_DATA_REQUEST = 0x04,
	IEEE802154_CFI_PAN_ID_CONFLICT_NOTIFICATION = 0x05,
	IEEE802154_CFI_ORPHAN_NOTIFICATION = 0x06,
	IEEE802154_CFI_BEACON_REQUEST = 0x07,
	IEEE802154_CFI_COORDINATOR_REALIGNEMENT = 0x08,
	IEEE802154_CFI_GTS_REQUEST = 0x09,
	IEEE802154_CFI_RESERVED = 0x0a,
};

struct ieee802154_command {
	uint8_t cfi;
	union {
		struct ieee802154_cmd_assoc_req assoc_req;
		struct ieee802154_cmd_assoc_res assoc_res;
		struct ieee802154_cmd_disassoc_note disassoc_note;
		struct ieee802154_cmd_coord_realign coord_realign;
		struct ieee802154_gts_request gts_request;
		/* Data request, PAN ID conflict, orphan notification
		 * or beacon request just provide the CFI.
		 */
	};
} __packed;

#define IEEE802154_CMD_CFI_LENGTH 1

/** Frame */
struct ieee802154_mpdu {
	struct ieee802154_mhr mhr;
	union {
		void *payload;
		struct ieee802154_beacon *beacon;
		struct ieee802154_command *command;
	};
	uint16_t payload_length;
};

/** Frame build parameters */
struct ieee802154_frame_params {
	struct {
		union {
			uint8_t ext_addr[IEEE802154_EXT_ADDR_LENGTH]; /* in big endian */
			uint16_t short_addr; /* in CPU byte order */
		};

		uint16_t len;
		uint16_t pan_id; /* in CPU byte order */
	} dst;

	uint16_t short_addr; /* in CPU byte order */
	uint16_t pan_id; /* in CPU byte order */
} __packed;

#ifdef CONFIG_NET_L2_IEEE802154_SECURITY
struct ieee802154_aux_security_hdr *
ieee802154_validate_aux_security_hdr(uint8_t *buf, uint8_t **p_buf, uint8_t *length);
#endif

struct ieee802154_fcf_seq *ieee802154_validate_fc_seq(uint8_t *buf, uint8_t **p_buf,
						      uint8_t *length);

bool ieee802154_validate_frame(uint8_t *buf, uint8_t length, struct ieee802154_mpdu *mpdu);

void ieee802154_compute_header_and_authtag_len(struct net_if *iface, struct net_linkaddr *dst,
					       struct net_linkaddr *src, uint8_t *ll_hdr_len,
					       uint8_t *authtag_len);

bool ieee802154_create_data_frame(struct ieee802154_context *ctx, struct net_linkaddr *dst,
				  struct net_linkaddr *src, struct net_buf *buf,
				  uint8_t ll_hdr_len);

struct net_pkt *ieee802154_create_mac_cmd_frame(struct net_if *iface, enum ieee802154_cfi type,
						struct ieee802154_frame_params *params);

void ieee802154_mac_cmd_finalize(struct net_pkt *pkt, enum ieee802154_cfi type);

static inline struct ieee802154_command *ieee802154_get_mac_command(struct net_pkt *pkt)
{
	return (struct ieee802154_command *)(pkt->frags->data + pkt->frags->len);
}

bool ieee802154_create_ack_frame(struct net_if *iface, struct net_pkt *pkt, uint8_t seq);

#ifdef CONFIG_NET_L2_IEEE802154_SECURITY
bool ieee802154_decipher_data_frame(struct net_if *iface, struct net_pkt *pkt,
				    struct ieee802154_mpdu *mpdu);
#else
#define ieee802154_decipher_data_frame(...) true
#endif /* CONFIG_NET_L2_IEEE802154_SECURITY */

#endif /* __IEEE802154_FRAME_H__ */