(TLI/XTI)

t_accept(NET)

t_accept -- accept a connect request

Syntax

TLI syntax

cc . . . -lnsl

#include <sys/tiuser.h>

int t_accept (fd, resfd, call)
int fd, resfd;
struct t_call *call;

XTI syntax

cc . . . -lxti

#include <xti.h>

int t_accept (fd, resfd, call)
int fd, resfd;
struct t_call *call;

Description

The t_accept function is issued by a transport user to accept a connect request. fd identifies the local transport endpoint where the connect indication arrived, resfd specifies the local transport endpoint where the connection is to be established, and call contains information required by the transport provider to complete the connection. call points to a t_call structure containing the following members:

       struct netbuf addr;   /* caller's address             */
       struct netbuf opt;    /* options                      */ 
       struct netbuf udata;  /* user data returned by caller */
       int sequence;         /* value returned by t_listen   */

Refer to netbuf(FP) for information about the netbuf structure. In call, addr is the address of the caller, opt indicates any protocol-specific parameters associated with the connection, udata points to any user data to be returned to the caller, and sequence is the value returned by t_listen that uniquely associates the response with a previously received connect indication.

A transport user may accept a connection on either the same, or on a different, local transport endpoint than the one on which the connect indication arrived. If the same endpoint is specified (that is, resfd=fd), the connection can be accepted unless the following condition is true: the user has received other indications on that endpoint but has not responded to them (with t_accept or t_snddis). For this condition, t_accept fails and sets t_errno to TBADF.

If a different transport endpoint is specified (resfd!=fd), the endpoint must be bound to a protocol address and must be in the T_IDLE state (see t_getstate(NET)) before the t_accept is issued.

For both types of endpoints, t_accept fails and set t_errno to TLOOK if there are indications (for example, a connect or disconnect) waiting to be received on that endpoint.

The values of parameters specified by opt and the syntax of those values are protocol specific. The udata argument enables the called transport user to send user data to the caller and the amount of user data must not exceed the limits supported by the transport provider as returned by t_open or t_getinfo. If the len field of udata is zero, no data is sent to the caller.

Return values

Upon successful completion, t_accept returns a value of 0. Otherwise, it returns a value of -1 and sets t_errno to indicate the error.

Diagnostics

On failure, t_errno may be set to one of the following:

[TACCES]: The user does not have permission to accept a connection on the responding transport endpoint or use the specified options.
[TBADDATA]: The amount of user data specified was not within the bounds allowed by the transport provider.
[TBADF]: The specified file descriptor does not refer to a transport endpoint, or the user is illegally accepting a connection on the same transport endpoint on which the connect indication arrived.
[TBADOPT]: The specified options were in an incorrect format or contained illegal information.
[TBADSEQ]: An invalid sequence number was specified.
[TFLOW]: A system error occurred while sending the connect request.
[TLOOK]: An asynchronous event has occurred on the transport endpoint referenced by fd and requires immediate attention.
[TNOTSUPPORT]: This function is not supported by the underlying transport provider.
[TOUTSTATE]: The function was issued in the wrong sequence on the transport endpoint referenced by fd, or the transport endpoint referred to by resfd is not in the T_IDLE state.
[TSYSERR]: A system error occurred during execution of this function.

Standards conformance

t_accept is conformant with:

AT&T SVID Issue 3 ;
X/Open CAE Specification, Networking Services, Issue 4, 1994. ;
and Intel386 Binary Compatibility Specification, Edition 2 (iBCSe2) .