Name

inet − Internet protocol family

Syntax

#include <sys/types.h>
#include <netinet/in.h>

Description

The Internet protocol family is a collection of protocols that is layered on the Internet Protocol (IP) transport layer and that uses the Internet address format.  The Internet family provides protocol support for the SOCK_STREAM, SOCK_DGRAM, and SOCK_RAW socket types.  The SOCK_RAW interface provides access to the IP protocol. 

Addressing

Internet addresses are 4-byte quantities, stored in network standard format.  The include file <netinet/in.h> defines this address as a discriminated union.

Sockets bound to the Internet protocol family use the following addressing structure:

struct sockaddr_in {
shortsin_family;
u_shortsin_port;
structin_addr sin_addr;
charsin_zero[8];
};

Sockets may be created with the address INADDR_ANY to effect “wildcard” matching on incoming messages.

Protocols

The Internet protocol family comprises the IP transport protocol, Internet Control Message Protocol (ICMP), Transmission Control Protocol (TCP), and User Datagram Protocol (UDP).  TCP is used to support the SOCK_STREAM abstraction, while UDP is used to support the SOCK_DGRAM abstraction.  A raw interface to IP and ICMP is available by creating an Internet socket of type SOCK_RAW. 

See Also

tcp(4p), udp(4p), ip(4p)