Next: Host Addresses, Up: Internet Namespace
In the Internet namespace, for both IPv4 (AF_INET) and IPv6
(AF_INET6), a socket address consists of a host address
and a port on that host. In addition, the protocol you choose serves
effectively as a part of the address because local port numbers are
meaningful only within a particular protocol.
The data types for representing socket addresses in the Internet namespace are defined in the header file netinet/in.h.
This is the data type used to represent socket addresses in the Internet namespace. It has the following members:
sa_family_t sin_family- This identifies the address family or format of the socket address. You should store the value
AF_INETin this member. See Socket Addresses.struct in_addr sin_addr- This is the Internet address of the host machine. See Host Addresses, and Host Names, for how to get a value to store here.
unsigned short int sin_port- This is the port number. See Ports.
When you call bind or getsockname, you should specify
sizeof (struct sockaddr_in) as the length parameter if
you are using an IPv4 Internet namespace socket address.
This is the data type used to represent socket addresses in the IPv6 namespace. It has the following members:
sa_family_t sin6_family- This identifies the address family or format of the socket address. You should store the value of
AF_INET6in this member. See Socket Addresses.struct in6_addr sin6_addr- This is the IPv6 address of the host machine. See Host Addresses, and Host Names, for how to get a value to store here.
uint32_t sin6_flowinfo- This is a currently unimplemented field.
uint16_t sin6_port- This is the port number. See Ports.