sitara_depot/components/free_rtos/ethernet_ip/eth_checksum.c

/*
 * eth_checksum.c
 *
 *  Created on: 13 мар. 2023 г.
 *      Author: sychev
 */
#include "free_rtos/ethernet_ip/eth_checksum.h"
#include "free_rtos/base/swap.h"

#include <arm_acle.h>

uint16_t eth_calcChksum(uint32_t sum, uint8_t * const data, uint16_t len)
{
    uint16_t i;
    uint16_t size = len - 1;

    if ( !len )
      return 0;

    for ( i = 0; i < size; i+=2 )
      sum += ((uint16_t)data[i] << 8) + data[i+1];

    if (len & 0x01)
      sum += (uint16_t)data[i] << 8;

    while ( sum >> 16 )
      sum = (sum & 0xFFFF) + (sum >> 16);

    return ~sum;
}

uint16_t eth_calcChksum2(uint32_t sum, uint8_t * const hdata, uint16_t hlen, uint8_t * const data, uint16_t len)
{
    uint16_t i;
    uint16_t hsize = hlen - 1;
    uint16_t size = len - 1;

    if ( (hlen == 0) || (len == 0) )
      return 0;

    for ( i = 0; i < hsize; i+=2 )
      sum += ((uint16_t)hdata[i] << 8) + hdata[i+1];

    if (hlen & 0x01)
      sum += (uint16_t)hdata[i] << 8;

    for ( i = 0; i < size; i+=2 )
      sum += ((uint16_t)data[i] << 8) + data[i+1];

    if (len & 0x01)
      sum += (uint16_t)data[i] << 8;

    while ( sum >> 16 )
      sum = (sum & 0xFFFF) + (sum >> 16);

    return ~sum;
}

union PointerConverter
{
    void * unknown;
    uint64_t * octet;
    uint32_t * quartet;
    uint16_t * duet;
    uint8_t * solo;
};

struct Array {
    uint16_t duet0;
    uint16_t duet1;
    uint16_t duet2;
    uint16_t duet3;
};

union ValueConverter
{
    uint64_t octet;
    uint32_t quartet;
    uint16_t duet;
    uint8_t solo;
    struct Array array;
};

uint32_t calcSum(void * const buffer, uint32_t sum, void * const data, uint16_t len)
{
    union PointerConverter buffer_start;
    union PointerConverter data_start;
    union ValueConverter value;

    buffer_start.unknown = buffer;
    data_start.unknown = data;

    while(len >= sizeof(uint32_t)) {
        len -= sizeof(uint32_t);

        value.quartet = *data_start.quartet++;
        *buffer_start.quartet++ = value.quartet;

        value.quartet = __rev16(value.quartet);
        sum += value.array.duet0 + value.array.duet1;
    }

    if(len >= sizeof(uint16_t)) {
        len -= sizeof(uint16_t);

        value.duet = *data_start.duet++;
        *buffer_start.duet++ = value.duet;

        value.quartet = __rev16(value.quartet);
        sum += value.duet;
    }

    if(len >= sizeof(uint8_t)) {
        len -= sizeof(uint8_t);

        value.solo = *data_start.solo++;
        *buffer_start.solo++ = value.solo;

        value.quartet = __rev16(value.quartet);
        sum += value.solo;
    }

    return sum;
}

uint16_t eth_calcChksum3(void * const buffer, uint32_t sum, void * const hdata, uint16_t hlen, void * const data, uint16_t len)
{
    if(hdata != 0) {
        sum = calcSum(buffer, sum, hdata, hlen);

    }

    if(data != 0) {
        sum = calcSum((uint8_t*)buffer + hlen, sum, data, len);
    }

    while (sum >> 16) {
      sum = (sum & 0xFFFF) + (sum >> 16);
    }

    return ~sum;
}