t_bind -- bind an address to a transport endpoint


TLI syntax

cc . . . -lnsl

#include <sys/tiuser.h>

int t_bind (fd, req, ret) int fd; struct t_bind *req; struct t_bind *ret;

XTI syntax

cc . . . -lxti

#include <xti.h>

int t_bind (fd, req, ret) int fd; struct t_bind *req; struct t_bind *ret;


The t_bind function associates a protocol address with the transport endpoint specified by fd and activates that transport endpoint. In connection mode, the transport provider may begin accepting or requesting connections on the transport endpoint. In connectionless mode, the transport user may send or receive data units through the transport endpoint.

The req and ret arguments point to a t_bind structure containing the following members:

   struct netbuf addr;

unsigned qlen;
netbuf is described in netbuf(FP). The addr field of the t_bind structure specifies a protocol address and the qlen field is used to indicate the maximum number of outstanding connect indications.

req is used to request that an address, represented by the netbuf structure, be bound to the given transport endpoint. len (see netbuf in netbuf(FP); also for buf and maxlen) specifies the number of bytes in the address and buf points to the address buffer. maxlen has no meaning for the req argument. On return, ret contains the address that the transport provider actually bound to the transport endpoint; this may be different from the address specified by the user in req. In ret, the user specifies maxlen which is the maximum size of the address buffer and buf which points to the buffer where the address is to be placed. On return, len specifies the number of bytes in the bound address and buf points to the bound address. If maxlen is not large enough to hold the returned address, an error results.

If the requested address is not available, or if no address is specified in req (the len field of addr in req is zero) the transport provider assigns an appropriate address to be bound, and returns that address in the addr field of ret. The user can compare the addresses in req and ret to determine whether the transport provider bound the transport endpoint to a different address than that requested.

req may be NULL if the user does not wish to specify an address to be bound. Here, the value of qlen is assumed to be zero, and the transport provider must assign an address to the transport endpoint. Similarly, ret may be NULL if the user does not care what address was bound by the provider and is not interested in the negotiated value of qlen. It is valid to set req and ret to NULL for the same call, in which case the provider chooses the address to bind to the transport endpoint and does not return that information to the user.

The qlen field has meaning only when initializing a connection-mode service. It specifies the number of outstanding connect indications the transport provider should support for the given transport endpoint. An outstanding connect indication is one that has been passed to the transport user by the transport provider. A value of qlen greater than zero is only meaningful when issued by a passive transport user that expects other users to call it. The value of qlen is negotiated by the transport provider and may be changed if the transport provider cannot support the specified number of outstanding connect indications. On return, the qlen field in ret contains the negotiated value.

This function allows more than one transport endpoint to be bound to the same protocol address (however, the transport provider must support this capability also), but it is not allowable to bind more than one protocol address to the same transport endpoint. If a user binds more than one transport endpoint to the same protocol address, only one endpoint can be used to listen for connect indications associated with that protocol address. In other words, only one t_bind for a given protocol address may specify a value of qlen greater than zero. In this way, the transport provider can identify which transport endpoint should be notified of an incoming connect indication. If a user attempts to bind a protocol address to a second transport endpoint with a value of qlen greater than zero, the transport provider assigns another address to be bound to that endpoint. If a user accepts a connection on the transport endpoint that is being used as the listening endpoint, the bound protocol address is found to be busy for the duration of that connection. No other transport endpoints may be bound for listening while that initial listening endpoint is in the data transfer phase. This prevents more than one transport endpoint bound to the same protocol address from accepting connect indications.

Return values

t_bind returns 0 on success and -1 on failure, and t_errno is set to indicate the error.


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

The user does not have permission to use the specified address.

The specified protocol address was in an incorrect format or contained illegal information.

The specified file descriptor does not refer to a transport endpoint.

The number of bytes allowed for an incoming argument is not sufficient to store the value of that argument. The provider's state changes to T_IDLE and the information to be returned in ret is discarded.

The transport provider could not allocate an address.

The function was issued in the wrong sequence.

A system error has occurred during execution of this function.

The address requested is in use and the transport provider could not allocate a new address.

See also

Intro(NET), netbuf(FP), t_open(NET), t_optmgmt(NET), t_unbind(NET)

Standards conformance

t_bind 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) .

© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003