ieee802154.h

/*
 * Copyright (C) 2015-2019 Freie Universität Berlin
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

/**
 * @defgroup    net_ieee802154 IEEE802.15.4
 * @ingroup     net
 * @brief       IEEE802.15.4 header definitions and utility functions
 * @{
 *
 * @file
 * @brief       IEEE 802.15.4 header definitions
 *
 * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
 */

#ifndef NET_IEEE802154_H
#define NET_IEEE802154_H

#include <stdint.h>
#include <stdlib.h>

#include "byteorder.h"
#include "net/eui64.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief   Default start frame delimiter
 */
#define IEEE802154_SFD                      (0xa7)

/**
 * @brief IEEE 802.15.4 address lengths
 * @{
 */
#define IEEE802154_SHORT_ADDRESS_LEN        (2U)    /**< short (16-bit) address */
#define IEEE802154_LONG_ADDRESS_LEN         (8U)    /**< long address (EUI-64) */
/**
 * @}
 */

/**
 * @brief IEEE802.15.4 FCF field definitions
 * @{
 */
#define IEEE802154_MAX_HDR_LEN              (23U)
#define IEEE802154_MIN_FRAME_LEN            (IEEE802154_FCF_LEN + sizeof(uint8_t))

#define IEEE802154_FCF_LEN                  (2U)
#define IEEE802154_FCS_LEN                  (2U)

#define IEEE802154_FCF_TYPE_MASK            (0x07)
#define IEEE802154_FCF_TYPE_BEACON          (0x00)
#define IEEE802154_FCF_TYPE_DATA            (0x01)
#define IEEE802154_FCF_TYPE_ACK             (0x02)
#define IEEE802154_FCF_TYPE_MACCMD          (0x03)

#define IEEE802154_FCF_SECURITY_EN          (0x08)  /**< enable security */
#define IEEE802154_FCF_FRAME_PEND           (0x10)  /**< follow-up frame is pending */
#define IEEE802154_FCF_ACK_REQ              (0x20)  /**< acknowledgement requested from receiver */
#define IEEE802154_FCF_PAN_COMP             (0x40)  /**< compress source PAN ID */

#define IEEE802154_FCF_DST_ADDR_MASK        (0x0c)
#define IEEE802154_FCF_DST_ADDR_VOID        (0x00)  /**< no destination address */
#define IEEE802154_FCF_DST_ADDR_RESV        (0x04)  /**< reserved address mode */
#define IEEE802154_FCF_DST_ADDR_SHORT       (0x08)  /**< destination address length is 2 */
#define IEEE802154_FCF_DST_ADDR_LONG        (0x0c)  /**< destination address length is 8 */

#define IEEE802154_FCF_VERS_MASK            (0x30)
#define IEEE802154_FCF_VERS_V0              (0x00)
#define IEEE802154_FCF_VERS_V1              (0x10)

#define IEEE802154_FCF_SRC_ADDR_MASK        (0xc0)
#define IEEE802154_FCF_SRC_ADDR_VOID        (0x00)  /**< no source address */
#define IEEE802154_FCF_SRC_ADDR_RESV        (0x40)  /**< reserved address mode */
#define IEEE802154_FCF_SRC_ADDR_SHORT       (0x80)  /**< source address length is 2 */
#define IEEE802154_FCF_SRC_ADDR_LONG        (0xc0)  /**< source address length is 8 */
/** @} */

/**
 * @brief   Channel ranges
 * @{
 */
#define IEEE802154_CHANNEL_MIN_SUBGHZ   (0U)    /**< Minimum channel for sub-GHz band */
#define IEEE802154_CHANNEL_MAX_SUBGHZ   (10U)   /**< Maximum channel for sub-GHz band */
#define IEEE802154_CHANNEL_MIN          (11U)   /**< Minimum channel for 2.4 GHz band */
#define IEEE802154_CHANNEL_MAX          (26U)   /**< Maximum channel for 2.4 GHz band */
/** @} */

#define IEEE802154_FRAME_LEN_MAX        (127U)  /**< maximum frame length */

/**
 * @brief   Special address definitions
 * @{
 */
/**
 * @brief   Static initializer for broadcast address
 */
#define IEEE802154_ADDR_BCAST               { 0xff, 0xff }

/**
 * @brief   Length in byte of @ref IEEE802154_ADDR_BCAST
 */
#define IEEE802154_ADDR_BCAST_LEN           (IEEE802154_SHORT_ADDRESS_LEN)

/**
 * @brief   Broadcast address
 */
extern const uint8_t ieee802154_addr_bcast[IEEE802154_ADDR_BCAST_LEN];
/** @} */

/**
 * @defgroup net_ieee802154_conf    IEEE802.15.4 compile configurations
 * @ingroup  config
 * @{
 */
/**
 * @brief IEEE802.15.4 default sub-GHZ channel
 */
#ifndef CONFIG_IEEE802154_DEFAULT_SUBGHZ_CHANNEL
#define CONFIG_IEEE802154_DEFAULT_SUBGHZ_CHANNEL   (5U)
#endif

/**
 * @brief IEEE802.15.4 default channel
 */
#ifndef CONFIG_IEEE802154_DEFAULT_CHANNEL
#define CONFIG_IEEE802154_DEFAULT_CHANNEL          (26U)
#endif

/**
 * @brief IEEE802.15.4 default sub-GHZ page
 */
#ifndef CONFIG_IEEE802154_DEFAULT_SUBGHZ_PAGE
#define CONFIG_IEEE802154_DEFAULT_SUBGHZ_PAGE      (2U)
#endif

/**
 * @brief IEEE802.15.4 default PANID
 */
#ifndef CONFIG_IEEE802154_DEFAULT_PANID
#define CONFIG_IEEE802154_DEFAULT_PANID            (0x0023U)
#endif

/**
 * @brief IEEE802.15.4 Broadcast PANID
 */
#ifndef IEEE802154_PANID_BCAST
#define IEEE802154_PANID_BCAST              { 0xff, 0xff }
#endif

/**
 * @brief IEEE802.15.4 default TX power (in dBm)
 */
#ifndef CONFIG_IEEE802154_DEFAULT_TXPOWER
#define CONFIG_IEEE802154_DEFAULT_TXPOWER          (0)
#endif
/** @} */

/**
 * @brief   Initializes an IEEE 802.15.4 MAC frame header in @p buf.
 *
 * @pre Resulting header must fit in memory allocated at @p buf.
 *
 * @see IEEE Std 802.15.4-2011, 5.2.1 General MAC frame format.
 *
 * If @p dst is NULL the IEEE802154_FCF_ACK_REQ will be unset to prevent
 * flooding the network.
 *
 * @param[out] buf      Target memory for frame header.
 * @param[in] src       Source address for frame in network byteorder.
 *                      May be NULL if @ref IEEE802154_FCF_SRC_ADDR_VOID is set
 *                      in @p flags.
 * @param[in] src_len   Length of @p src. Legal values are:
 *                      * 0 (will set @ref IEEE802154_FCF_SRC_ADDR_VOID in MHR)
 *                      * 2 (will set @ref IEEE802154_FCF_SRC_ADDR_SHORT in MHR)
 *                      * 8 (will set @ref IEEE802154_FCF_SRC_ADDR_LONG in MHR)
 * @param[in] dst       Destination address for frame in network byteorder.
 *                      May be NULL if @ref IEEE802154_FCF_SRC_ADDR_VOID is set
 *                      in @p flags.
 * @param[in] dst_len   Length of @p dst. Legal values are:
 *                      * 0 (will set @ref IEEE802154_FCF_DST_ADDR_VOID in MHR)
 *                      * 2 (will set @ref IEEE802154_FCF_DST_ADDR_SHORT in MHR)
 *                      * 8 (will set @ref IEEE802154_FCF_DST_ADDR_LONG in MHR)
 * @param[in] src_pan   Source PAN ID in little-endian. May be 0 if
 *                      @ref IEEE802154_FCF_PAN_COMP is set in @p flags.
 *                      Otherwise, it will be ignored, when
 *                      @ref IEEE802154_FCF_PAN_COMP is set.
 * @param[in] dst_pan   Destination PAN ID in little-endian.
 * @param[in] flags     Flags for the frame. These are interchangeable with the
 *                      first byte of the IEEE 802.15.4 FCF. This means that
 *                      it encompasses the type values,
 *                      @ref IEEE802154_FCF_SECURITY_EN,
 *                      @ref IEEE802154_FCF_FRAME_PEND, and
 *                      @ref IEEE802154_FCF_ACK_REQ.
 * @param[in] seq       Sequence number for frame.
 *
 * The version field in the FCF will be set implicitly to version 1.
 *
 * @return  Size of frame header on success.
 * @return  0, on error (flags set to unexpected state).
 */
size_t ieee802154_set_frame_hdr(uint8_t *buf, const uint8_t *src, size_t src_len,
                                const uint8_t *dst, size_t dst_len,
                                le_uint16_t src_pan, le_uint16_t dst_pan,
                                uint8_t flags, uint8_t seq);

/**
 * @brief   Get length of MAC header.
 *
 * @todo include security header implications
 *
 * @param[in] mhr   MAC header.
 *
 * @return  Length of MAC header on success.
 * @return  0, on error (source mode or destination mode set to reserved).
 */
size_t ieee802154_get_frame_hdr_len(const uint8_t *mhr);

/**
 * @brief   Gets source address from MAC header.
 *
 * @pre (@p src != NULL) && (@p src_pan != NULL)
 *
 * @param[in] mhr       MAC header.
 * @param[out] src      Source address in network byte order in MAC header.
 * @param[out] src_pan  Source PAN little-endian byte order in MAC header.
 *
 * @return   Length of source address.
 * @return  -EINVAL, if @p mhr contains unexpected flags.
 */
int ieee802154_get_src(const uint8_t *mhr, uint8_t *src, le_uint16_t *src_pan);

/**
 * @brief   Gets destination address from MAC header.
 *
 * @pre (@p dst != NULL) && (@p dst_pan != NULL)
 *
 * @param[in] mhr       MAC header.
 * @param[out] dst      Destination address in network byte order in MAC header.
 * @param[out] dst_pan  Destination PAN in little-endian byte order in MAC header.
 *
 * @return   Length of destination address.
 * @return  -EINVAL, if @p mhr contains unexpected flags.
 */
int ieee802154_get_dst(const uint8_t *mhr, uint8_t *dst, le_uint16_t *dst_pan);

/**
 * @brief   Gets sequence number from MAC header.
 *
 * @pre length of allocated space at @p mhr > 3
 *
 * @param[in] mhr   MAC header.
 *
 * @return  The sequence number in @p mhr.
 */
static inline uint8_t ieee802154_get_seq(const uint8_t *mhr)
{
    return mhr[2];
}

/**
 * @brief   Generates an IPv6 interface identifier from an IEEE 802.15.4 address.
 *
 * @pre (@p eui64 != NULL) && (@p addr != NULL)
 * @see <a href="https://tools.ietf.org/html/rfc4944#section-6">
 *          RFC 4944, section 6
 *      </a>
 * @see <a href="https://tools.ietf.org/html/rfc6282#section-3.2.2">
 *          RFC 6282, section 3.2.2
 *      </a>
 *
 * @param[out] eui64    The resulting EUI-64.
 * @param[in] addr      An IEEE 802.15.4 address.
 * @param[in] addr_len  The length of @p addr. Must be 2 (short address),
 *                      4 (PAN ID + short address), or 8 (long address).
 *
 * @return Copy of @p eui64 on success.
 * @return NULL, if @p addr_len was of illegal length.
 */
static inline eui64_t *ieee802154_get_iid(eui64_t *eui64, const uint8_t *addr,
                                          size_t addr_len)
{
    int i = 0;

    eui64->uint8[0] = eui64->uint8[1] = 0;

    switch (addr_len) {
        case 8:
            eui64->uint8[0] = addr[i++] ^ 0x02;
            eui64->uint8[1] = addr[i++];
            eui64->uint8[2] = addr[i++];
            eui64->uint8[3] = addr[i++];
            eui64->uint8[4] = addr[i++];
            eui64->uint8[5] = addr[i++];
            eui64->uint8[6] = addr[i++];
            eui64->uint8[7] = addr[i++];
            break;

        case 4:
            eui64->uint8[0] = addr[i++] ^ 0x02;
            eui64->uint8[1] = addr[i++];

            /* Falls through. */
        case 2:
            eui64->uint8[2] = 0;
            eui64->uint8[3] = 0xff;
            eui64->uint8[4] = 0xfe;
            eui64->uint8[5] = 0;
            eui64->uint8[6] = addr[i++];
            eui64->uint8[7] = addr[i++];
            break;

        default:
            return NULL;
    }

    return eui64;
}

#ifdef __cplusplus
}
#endif

#endif /* NET_IEEE802154_H */
/** @} */