NAME

inet − Internet protocol family

SYNOPSIS

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

DESCRIPTION

The Internet protocol family is a collection of protocols layered atop the Internet Protocol (IP) transport layer, and utilizing 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 four byte quantities, stored in network standard format (on the VAX these are word and byte reversed).  The include file <netinet/in.h> defines this address as a discriminated union. 

Sockets bound to the Internet protocol family utilize 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 is comprised of 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 is available by creating an Internet socket of type SOCK_RAW.  The ICMP message protocol is not directly accessible. 

SEE ALSO

tcp(4P), udp(4P), ip(4P)

CAVEAT

The Internet protocol support is subject to change as the Internet protocols develop.  Users should not depend on details of the current implementation, but rather the services exported. 

CX/UX Networking