AF_INET6 socket addresses in an Internet domain

See z/OS Communications Server: IPv6 Network and Application Design Guide for parts of the AF_INET6 family. The structure of an Internet socket address is defined by the following sockaddr_in6 structure, which is found in header file IN.H:

struct in6_addr
{
   union
   {
     uint8_t_    S6_u8[16];
     uint32_t_   S6_u32[4];
   }
   _S6_un;
};

#define s6_addr_S6_un._S6_u8

#define SIN6_LEN

struct sockaddr_in6
{
        uint8_t          sin6_len;
        sa_family_t      sin6_family;
        in_port_t        sin6_port;
        uint32_t         sin6_flowinfo;
        struct in6_addr  sin6_addr;
        uint32_t         sin6_scope_id;
};

The sin6_family field is set to AF_INET6. The sin6_port field is a halfword binary field that is the port used by the application, in network byte order. The sin6_addr field specifies a 128-bit Internet address. The sin6_addr field is the Internet address of the network interface used by the application; it is also in network byte order. The sin6_flowinfo field is a fullword binary field specifying the traffic class and flow label. This field is currently not implemented. The sin6_scope_id field identifies a set of interfaces as appropriate for the scope of the address carried in the sin6_addr field.