t_optmgmt(3N) manual page
Table of Contents
t_optmgmt - manage options for a transport endpoint
cc [ flag
... ] file ... -lnsl [ library ... ]
#include <tiuser.h>
int t_optmgmt(int fildes,
const struct t_optmgmt *req, struct t_optmgmt *ret);
MT-Safe
The t_optmgmt() function enables a transport user to retrieve, verify,
or negotiate protocol options with the transport provider. fildes identifies
a bound transport endpoint.
The req and ret arguments point to a t_optmgmt
structure containing the following members:
struct netbuf opt;
long flags;
The opt field identifies protocol options and the flags field is used to
specify the action to take with those options.
The options are represented
by a netbuf (see t_connect(3N)
; also for len, buf, and maxlen) structure
in a manner similar to the address in t_bind(3N)
. req is used to request
a specific action of the provider and to send options to the provider. len
specifies the number of bytes in the options, buf points to the options
buffer, and maxlen has no meaning for the req argument. The transport provider
may return options and flag values to the user through ret. For ret, maxlen
specifies the maximum size of the options buffer and buf points to the
buffer where the options are to be placed. On return, len specifies the
number of bytes of options returned. maxlen has no meaning for the req argument,
but must be set in the ret argument to specify the maximum number of bytes
the options buffer can hold. The actual structure and content of the options
is imposed by the transport provider.
The flags field of req can specify
one of the following actions:
- T_NEGOTIATE
- This action enables the user
to negotiate the values of the options specified in req with the transport
provider. The provider will evaluate the requested options and negotiate
the values, returning the negotiated values through ret.
- T_CHECK
- This action
enables the user to verify whether the options specified in req are supported
by the transport provider. On return, the flags field of ret will have either
T_SUCCESS
or T_FAILURE
set to indicate to the user whether the options
are supported. These flags are only meaningful for the T_CHECK request.
- T_DEFAULT
- This action enables a user to retrieve the default options supported by
the transport provider into the opt field of ret. In req, the len field
of opt must be zero and the buf field may be NULL
.
If issued as part of
the connectionless-mode service, t_optmgmt() may block due to flow control
constraints. The function will not complete until the transport provider
has processed all previously sent data units.
t_optmgmt() returns
0 on success. On failure t_optmgmt() returns -1, t_errno is set to indicate
the error, and possibly errno is set.
On failure, t_errno will be
set to one of the following:
- TBADF
- The specified file descriptor does
not refer to a transport endpoint.
- TACCES
- The user does not have permission
to negotiate the specified options.
- TBADFLAG
- An invalid flag was specified.
- TBADOPT
- The specified protocol options were in an incorrect format or
contained illegal information.
- TBUFOVFLW
- The number of bytes allowed for
an incoming argument is not sufficient to store the value of that argument.
The information to be returned in ret will be discarded.
- TOUTSTATE
- The
function was issued in the wrong sequence.
- TSYSERR
- A system error has occurred
during execution of this function, errno will be set to the specific error.
t_bind(3N)
, t_connect(3N)
, t_getinfo(3N)
, t_open(3N)
This
interface is safe in multithreaded applications.
Table of Contents
![[Go to CFHT Home Page]](/images/cfht-icon.gif){kind=icon}
Man Pages 
Back to Software Index 
Manpage Top Level