参考 http://www.faqs.org/rfcs/rfc1071.html，我尝试推导出用于计算 ICMPv6 校验和的 c 代码。但是通过wireshark检查校验和解析，我发现从我的代码中得到的答案是错误的......

由wireshark解析的校验和是0x8e73。

以下是我的代码，与 RFC 中提到的完全相同。注意：数组数据是从 ICMPv6 获得的原始数据

unsigned short checksum(unsigned short *addr, unsigned short count)
{
    unsigned long sum;

    sum = 0;
    while (count > 1) {
            sum += *(unsigned short*)addr++;
            count -= 2;
            printf("sum is %x\n", sum);
    }

    /*  Add left-over byte, if any */
    if (count){
            sum += *(unsigned char *)addr;
            printf("in side left-over byte\n");
    }
    /*  Fold 32-bit sum to 16 bits */
    while (sum >> 16) {
            sum  = (sum & 0xffff) + (sum >> 16);
            printf("IN while:sum is %x\n", sum);
    }
    printf("sum is %x\n", sum);
    return (unsigned short)(~sum);
}

int main() {
    unsigned short count = 32;
    //data is the raw data for ICMPv6 got from wireshark, and I put the checksum field as 0x0000
    unsigned short data[] = {0x8800, 0x0000, 0x6000, 0x0000, 0xfe80, 0x0000, 0x0000, 0x0000, 0xb96b, 0x982f, 0x447a, 0x6a80, 0x0201, 0x6057, 0x187d, 0x7fad};


    printf("check sum is %x\n", checksum(data, 32));
    return 0;
}