32位数值转化为8位IP地址

#define u8 unsigned char
#define u32 unsigned int
#define SWAP32(ipValue) ((u32)(((ipValue) & 0xff) << 24) | \
                        (((ipValue) & 0xff00) << 8) | \
                        (((ipValue) >> 8)  & 0xff00) | \
                        (((ipValue) >> 24) & 0xff) ); \

int main()
{
    u8 ip_addr[4] = {0};
    unsigned long src = 0x93d4860a;
    src = SWAP32(src)
    ip_addr[0] = (u8) ((src >> 24) & 0xff);
    ip_addr[1] = (u8 ) ((src >> 16) & 0xff);
    ip_addr[2] = (u8 ) ((src >> 8) & 0xff);
    ip_addr[3] = (u8 ) (src & 0xff);
    printf("src = %d.%d.%d.%d \n",ip_addr[0],ip_addr[1],ip_addr[2],ip_addr[3]);
    unsigned long dst = 0x3ba41d73;
    dst = SWAP32(dst)
    ip_addr[0] = (u8 ) ((dst >> 24) & 0xff);
    ip_addr[1] = (u8 ) ((dst >> 16) & 0xff);
    ip_addr[2] = (u8 ) ((dst >> 8) & 0xff);
    ip_addr[3] = (u8 ) (dst & 0xff);
    printf("dst = %d.%d.%d.%d \n",ip_addr[0],ip_addr[1],ip_addr[2],ip_addr[3]);
}