hdr.h

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/*
 * SPDX-FileCopyrightText: 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
 * SPDX-License-Identifier: LGPL-2.1-only
 */
 
#pragma once

 
#include <stdint.h>
 
#include "byteorder.h"
#include "net/inet_csum.h"
#include "net/ipv6/addr.h"
 
#ifdef __cplusplus
extern "C" {
#endif

typedef struct __attribute__((packed)) {
    network_uint32_t v_tc_fl;
    network_uint16_t len;   
    uint8_t nh;             
    uint8_t hl;             
    ipv6_addr_t src;     
    ipv6_addr_t dst;     
} ipv6_hdr_t;

static inline void ipv6_hdr_set_version(ipv6_hdr_t *hdr)
{
    hdr->v_tc_fl.u8[0] &= 0x0f;
    hdr->v_tc_fl.u8[0] |= 0x60;
}

static inline uint8_t ipv6_hdr_get_version(const ipv6_hdr_t *hdr)
{
    return ((hdr->v_tc_fl.u8[0]) >> 4);
}

static inline bool ipv6_hdr_is(const ipv6_hdr_t *hdr)
{
    return (((hdr->v_tc_fl.u8[0]) & 0xf0) == 0x60);
}

static inline void ipv6_hdr_set_tc(ipv6_hdr_t *hdr, uint8_t tc)
{
    hdr->v_tc_fl.u8[0] &= 0xf0;
    hdr->v_tc_fl.u8[0] |= (0x0f & (tc >> 4));
    hdr->v_tc_fl.u8[1] &= 0x0f;
    hdr->v_tc_fl.u8[1] |= (0xf0 & (tc << 4));
}

static inline void ipv6_hdr_set_tc_ecn(ipv6_hdr_t *hdr, uint8_t ecn)
{
    hdr->v_tc_fl.u8[0] &= 0xf3;
    hdr->v_tc_fl.u8[0] |= (0x0c & (ecn << 2));
}

static inline void ipv6_hdr_set_tc_dscp(ipv6_hdr_t *hdr, uint8_t dscp)
{
    hdr->v_tc_fl.u8[0] &= 0xfc;
    hdr->v_tc_fl.u8[0] |= (0x03 & (dscp >> 4));
    hdr->v_tc_fl.u8[1] &= 0x0f;
    hdr->v_tc_fl.u8[1] |= (0xf0 & (dscp << 4));
}

static inline uint8_t ipv6_hdr_get_tc(const ipv6_hdr_t *hdr)
{
    return ((((hdr->v_tc_fl.u8[0]) & 0x0f) << 4) |
            ((hdr->v_tc_fl.u8[1] & 0xf0) >> 4));
}

static inline uint8_t ipv6_hdr_get_tc_ecn(const ipv6_hdr_t *hdr)
{
    return (((hdr->v_tc_fl.u8[0]) & 0x0c) >> 2);
}

static inline uint8_t ipv6_hdr_get_tc_dscp(const ipv6_hdr_t *hdr)
{
    return ((((hdr->v_tc_fl.u8[0]) & 0x03) << 4) |
            ((hdr->v_tc_fl.u8[1] & 0xf0) >> 4));
}

static inline void ipv6_hdr_set_fl(ipv6_hdr_t *hdr, uint32_t fl)
{
    hdr->v_tc_fl.u8[1] &= 0xf0;
    hdr->v_tc_fl.u8[1] |= (0x0f & (byteorder_htonl(fl).u8[1]));
    hdr->v_tc_fl.u16[1] = byteorder_htonl(fl).u16[1];
}

static inline uint32_t ipv6_hdr_get_fl(const ipv6_hdr_t *hdr)
{
    return byteorder_ntohl(hdr->v_tc_fl) & 0x000fffff;
}

static inline uint16_t ipv6_hdr_inet_csum(uint16_t sum, ipv6_hdr_t *hdr,
                                          uint8_t prot_num, uint16_t len)
{
    if (((uint32_t)sum + len + prot_num) > 0xffff) {
        /* increment by one for overflow to keep it as 1's complement sum */
        sum++;
    }
 
    return inet_csum(sum + len + prot_num, hdr->src.u8,
                     (2 * sizeof(ipv6_addr_t)));
}

void ipv6_hdr_print(ipv6_hdr_t *hdr);
 
#ifdef __cplusplus
}
#endif