t_bind(3)

NAME

t_bind() — bind an address to a transport endpoint

SYNOPSIS

#include <xti.h>            /* for X/OPEN Transport Interface - XTI */
/* or */
#include <tiuser.h>         /* for Transport Layer Interface - TLI  */

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

DESCRIPTION

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 enqueuing incoming connect indications or servicing a connection request 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;

The type netbuf structure is defined in the <xti.h> or <tiuser.h> header file. This structure, which is used to define buffer parameters, has the following members:

unsigned int maxlen: maximum byte length of the data buffer
unsigned int len: actual byte length of data written to buffer
char *buf: points to buffer location

The addr field of the t_bind structure specifies a protocol address. The qlen field is used to indicate the maximum number of outstanding connect indications.

The parameter req is used to request that an address, represented by the netbuf structure, be bound to the given transport endpoint. The parameter len specifies the number of bytes in the address, and buf points to the address buffer. The parameter maxlen has no meaning for the req argument. On return, ret contains the address of that the transport provider actually bound to the transport endpoint. This is the same as the address specified 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 will result.

If the request address is not available, t_bind() will return -1 with t_errno set as appropriate. If no address is specified in req (the len field of addr in req is zero or req is NULL), the transport provider will assign an appropriate address to be bound, and will return that address in the addr field of ret. If the transport provider could not allocate an address, t_bind() will fail with t_errno set to [TNOADDR]. HP OSI does not support the automatic generation of an address.

The parameter req may be a null pointer 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 will assign an address to the transport endpoint. Similarly, ret may be a null pointer 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 the null pointer 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 that 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 but which has not been accepted or rejected. A value of qlen greater than zero is only meaningful when issued by a passive transport user that expects others to call it. The value of qlen will be negotiated by the transport provider and may be changed if the transport provider cannot support the specified number of outstanding connect indications. However, this value of qlen will never be negotiated from a requested value greater than zero to zero. This is a requirement on transport providers; see Caveats below. On return, the qlen field in ret will contain the negotiated value.

If fd refers to a connection-mode service, this function allows more than one transport endpoint to be bound to the same protocol address (however, the transport provider must also support this capability), but it is not possible 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 the 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, t_bind() will return -1 and set t_errno to [TADDRBUSY] (XTI) or [TBADADDR] (TLI). When a user accepts a connection on the transport endpoint that is being used as the listening endpoint, the bound protocol address will be found to be busy for the duration of the connection, until a t_unbind() or t_close() call has been issued. No other transport endpoints may be bound for listening on the same protocol address while that initial listening endpoint is active (in the data transfer phase or in the T_IDLE state). This will prevent more than one transport endpoint bound to the same protocol address from accepting connect indications.

If fd refers to a connectionless-mode service, only one endpoint may be associated with a protocol address. If a user attempts to bind a second transport endpoint to an already bound address, t_bind() will return -1 and set t_errno to [TADDRBUSY].

Valid States

T_UNBND

Note

HP XTI does not support automatic generation of addresses. Therefore a valid local transport address must be specified in req.

Caveats

The requirement that the value of qlen never be negotiated from a requested value greater than zero to zero implies that transport providers, rather than the XTI implementation itself, accept this restriction.

A transport provider may not allow an explicit binding of more than one transport endpoint to the same protocol address although it allows more than one connection to be accepted for the same protocol address. To ensure portability, it is, therefore, recommended not to bind transport endpoints that are used as responding endpoints (resfd) in a call to t_accept() if the responding address is to be the same as the called address.

Fork Safety

t_bind is not fork-safe.

RETURN VALUE

Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and t_errno is set to indicate the error.

ERRORS

On failure, t_errno is set to one of the following:

[TBADF]: The specified file descriptor does not refer to a transport endpoint.
[TOUTSTATE]: The function was issued in the wrong sequence.
[TBADADDR]: The specified protocol address was in an incorrect format or contained illegal information.
[TNOADDR]: The transport provider could not allocate an address.
[TACCES]: The user does not have permission to use the specified address.
[TBUFOVFLW]: The number of bytes allowed for an incoming argument is not sufficient to store the value of that argument. The provider's state will change to T_IDLE and the information to be returned in ret will be discarded.
[TSYSERR]: A system error has occurred during execution of this function.
[TADDRBUSY]: The address requested is in use and the transport provider could not allocate a new address.
[TPROTO]: (XTI only) This error indicates that a communication problem has been detected between XTI and the transport provider for which there is no suitable XTI (t_errno).

FILES

/usr/include/xti.h: XTI data structures
/usr/include/xti_iso.h: XTI data structures
/usr/include/tiuser.h: TLI data structures

STANDARDS CONFORMANCE

t_bind(): SVID2, XPG3, XPG4