tcp套接字地址

struct in_addr 
{
    in_addr_t s_addr; /* 32-bits IPV4 address network byte ordered   <netinet/in.h> */
};

struct sockaddr_in 
{
    uint8_t         sin_len;
    sa_family_t     sin_family; //uint8_t   <sys/socket.h>
    in_port_t          sin_port;   //uint16_t
    struct in_addr     sin_addr;
    char             sin_zero[8];
};

struct sockaddr
{
    uint8_t        sa_len;
    sa_family_t    sa_family;
    char         sa_data[14]
};