HP X.25/9000 Programmer's Guide

28 Chapter3

Establishing and Terminating a Socket Connection

Connection Establishment for the Server Process

must specify AF_CCITT.

type Identiﬁes the type of socket. For X.25 programmatic access, you must

specify SOCK_STREAM.

protocol Identiﬁes the underlying protocol to be used for the socket. For X.25

programmatic access, specify X25_PROTO_NUM (or 0 to specify that the

default, which is

X25_PROTO_NUM

, is used).

sd If the connection is successful,

contains the socket descriptor for the

newly-created socket. If the system call encountered an error, –1 is

returned in

and

errno

contains the error code.

The socket descriptor returned by socket() references the

newly-created socket. This descriptor is used for the subsequent system

calls used to establish an SVC (bind(), listen(), and accept()).

Refer to the socket(2) entry in your man pages for more information.

Binding an X.121 Address to a Socket

After your server process has created a socket and before a listen()

system call is executed, the server must call bind() to associate an

X.121 address to the socket. Until an address is bound to the server

socket X.25 cannot reach your server.

Syntax for bind()

The bind() system call and its parameters are described below.

#include <sys/types.h>

#include <sys/socket.h>

#include <x25/x25addrstr.h>

int error;

int sd, addrlen;

struct x25addrstr bind_addr;

addrlen = sizeof(struct x25addrstr);

error = bind(sd, &bind_addr, addrlen)

sd Socket (returned from a previous socket() system call) to which the

address will be bound.

bind_addr x25addrstr structure which contains addressing information. The

addressing information deﬁnes the types of CALL REQUEST packets

36960-90061.bk Page 28 Friday, November 10, 2000 3:42 PM