/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
/*
 *  IPv6 IOAM implementation
 *
 *  Author:
 *  Justin Iurman <[email protected]>
 */

#ifndef _LINUX_IOAM6_H
#define _LINUX_IOAM6_H

#include <asm/byteorder.h>
#include <linux/types.h>

#define IOAM6_U16_UNAVAILABLE U16_MAX
#define IOAM6_U32_UNAVAILABLE U32_MAX
#define IOAM6_U64_UNAVAILABLE U64_MAX

#define IOAM6_DEFAULT_ID (IOAM6_U32_UNAVAILABLE >> 8)
#define IOAM6_DEFAULT_ID_WIDE (IOAM6_U64_UNAVAILABLE >> 8)
#define IOAM6_DEFAULT_IF_ID IOAM6_U16_UNAVAILABLE
#define IOAM6_DEFAULT_IF_ID_WIDE IOAM6_U32_UNAVAILABLE

/*
 * IPv6 IOAM Option Header
 */
struct ioam6_hdr {
    __u8 opt_type;
    __u8 opt_len;
    __u8 :8;                /* reserved */
#define IOAM6_TYPE_PREALLOC 0
    __u8 type;
} __attribute__((packed));

/*
 * IOAM Trace Header
 */
struct ioam6_trace_hdr {
    __be16    namespace_id;

#if defined(__LITTLE_ENDIAN_BITFIELD)

    __u8    :1,                /* unused */
        :1,                /* unused */
        overflow:1,
        nodelen:5;

    __u8    remlen:7,
        :1;                /* unused */

    union {
        __be32 type_be32;

        struct {
            __u32    bit7:1,
                bit6:1,
                bit5:1,
                bit4:1,
                bit3:1,
                bit2:1,
                bit1:1,
                bit0:1,
                bit15:1,    /* unused */
                bit14:1,    /* unused */
                bit13:1,    /* unused */
                bit12:1,    /* unused */
                bit11:1,
                bit10:1,
                bit9:1,
                bit8:1,
                bit23:1,    /* reserved */
                bit22:1,
                bit21:1,    /* unused */
                bit20:1,    /* unused */
                bit19:1,    /* unused */
                bit18:1,    /* unused */
                bit17:1,    /* unused */
                bit16:1,    /* unused */
                :8;        /* reserved */
        } type;
    };

#elif defined(__BIG_ENDIAN_BITFIELD)

    __u8    nodelen:5,
        overflow:1,
        :1,                /* unused */
        :1;                /* unused */

    __u8    :1,                /* unused */
        remlen:7;

    union {
        __be32 type_be32;

        struct {
            __u32    bit0:1,
                bit1:1,
                bit2:1,
                bit3:1,
                bit4:1,
                bit5:1,
                bit6:1,
                bit7:1,
                bit8:1,
                bit9:1,
                bit10:1,
                bit11:1,
                bit12:1,    /* unused */
                bit13:1,    /* unused */
                bit14:1,    /* unused */
                bit15:1,    /* unused */
                bit16:1,    /* unused */
                bit17:1,    /* unused */
                bit18:1,    /* unused */
                bit19:1,    /* unused */
                bit20:1,    /* unused */
                bit21:1,    /* unused */
                bit22:1,
                bit23:1,    /* reserved */
                :8;        /* reserved */
        } type;
    };

#else
#error "Please fix <asm/byteorder.h>"
#endif

#define IOAM6_TRACE_DATA_SIZE_MAX 244
    __u8    data[];
} __attribute__((packed));

#endif /* _LINUX_IOAM6_H */