xref: /titanic_50/usr/src/man/man3nsl/t_rcvvudata.3nsl (revision 3d729aecc03ea6ebb9bd5d56b8dccd24f57daa41)
te
Copyright 1994, The X/Open Company Ltd. All Rights Reserved Portions Copyright 1989 AT&T Portions Copyright (c) 1998, Sun Microsystems, Inc. All Rights Reserved
Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.
The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.
This notice shall appear on any product containing this material.
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
T_RCVVUDATA 3NSL "May 7, 1998"
NAME
t_rcvvudata - receive a data unit into one or more noncontiguous buffers
SYNOPSIS

#include <xti.h>



int t_rcvvudata(int fd, struct t_unitdata *unitdata, struct t_iovec *iov,
 unsigned int iovcount, int *flags);
DESCRIPTION

This function is used in connectionless mode to receive a data unit from another transport user. The argument fd identifies the local transport endpoint through which data will be received, unitdata holds information associated with the received data unit, iovcount contains the number of non-contiguous udata buffers which is limited to T_IOV_MAX, which is an implementation-defined value of at least 16, and flags is set on return to indicate that the complete data unit was not received. If the limit on iovcount is exceeded, the function fails with TBADDATA. The argument unitdata points to a t_unitdata structure containing the following members:

struct netbuf addr;
struct netbuf opt;
struct netbuf udata;

The maxlen field of addr and opt must be set before calling this function to indicate the maximum size of the buffer for each. The udata field of t_unitdata is not used. The iov_len and iov_base fields of "iov0" through iov [iovcount-1] must be set before calling t_rcvvudata() to define the buffer where the userdata will be placed. If the maxlen field of addr or opt is set to zero then no information is returned in the buf field for this parameter.

On return from this call, addr specifies the protocol address of the sending user, opt identifies options that were associated with this data unit, and iov[0].iov_base through iov [iovcount-1].iov_base contains the user data that was received. The return value of t_rcvvudata() is the number of bytes of user data given to the user.

Note that the limit on the total number of bytes available in all buffers passed:

iov(0).iov_len + . . + iov(iovcount-1).iov_len)

may be constrained by implementation limits. If no other constraint applies, it will be limited by INT_MAX. In practice, the availability of memory to an application is likely to impose a lower limit on the amount of data that can be sent or received using scatter/gather functions.

By default, t_rcvvudata() operates in synchronous mode and waits for a data unit to arrive if none is currently available. However, if O_NONBLOCK is set by means of t_open(3NSL) or fcntl(2), t_rcvvudata() executes in asynchronous mode and fails if no data units are available.

If the buffers defined in the iov[] array are not large enough to hold the current data unit, the buffers will be filled and T_MORE will be set in flags on return to indicate that another t_rcvvudata() should be called to retrieve the rest of the data unit. Subsequent calls to t_rcvvudata() will return zero for the length of the address and options, until the full data unit has been received.

RETURN VALUES

On successful completion, t_rcvvudata() returns the number of bytes received. Otherwise, it returns -1 on failure and t_errno is set to indicate the error.

VALID STATES

T_IDLE.

ERRORS

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

iovcount is greater than T_IOV_MAX.

TBADF

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

TBUFOVFLW

The number of bytes allocated for the incoming protocol address or options (maxlen) is greater than 0 but not sufficient to store the information. The unit data information to be returned in unitdata will be discarded.

TLOOK

An asynchronous event has occurred on this transport endpoint and requires immediate attention.

TNODATA

O_NONBLOCK was set, but no data units are currently available from the transport provider.

TNOTSUPPORT

This function is not supported by the underlying transport provider.

TOUTSTATE

The communications endpoint referenced by fd is not in one of the states in which a call to this function is valid.

TPROTO

This error indicates that a communication problem has been detected between XTI and the transport provider for which there is no other suitable XTI error (t_errno).

TSYSERR

A system error has occurred during execution of this function.

TLI COMPATIBILITY

In the TLI interface definition, no counterpart of this routine was defined.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
MT Level Safe
SEE ALSO

fcntl(2), t_alloc(3NSL), t_open(3NSL), t_rcvudata(3NSL), t_rcvuderr(3NSL), t_sndudata(3NSL), t_sndvudata(3NSL), attributes(5)