t_optmgmt(3xti) t_optmgmt(3xti)
Name
t_optmgmt - manage options for a transport endpoint
Syntax
#include <xti.h>
int t_optmgmt(fd, req, ret)
int fd;
struct t_optmgmt *req;
struct t_optmgmt *ret;
Arguments
fd Identifies a bound transport endpoint.
req Points to a t_optmgmt structure. See also ret argument.
ret Points to a t_optmgmt structure containing the following members:
struct netbuf opt;
long flags;
The meanings of the fields are as follows:
opt Identifies protocol options.
flags
Specifies the action to take with these options.
The options are represented by a netbuf structure in a manner similar to the address in The req argument is used to request a specific
action of the provider and to send options to the provider. The len field specifies the number of bytes in the options. The buf field
points to the options buffer, and the maxlen field has no meaning for the req argument. The transport provider can 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. The maxlen field has no meaning for the req
argument, but must be set in the ret argument to specify the maximum number of bytes the option buffer can hold. The actual structure and
content of the options is imposed by the transport provider.
The flags field of req must 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 transport provider evaluates the requested options and negotiates the values, returns 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 has either T_SUCCESS or T_FAILURE set to indicate to the user whether
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.
Description
The function enables a transport user to receive, verify, or negotiate protocol options with the transport provider.
If issued as part of the connectionless-mode service, may block due to flow control constraints. That is, the function does not complete
until the transport provider has processed all previously sent data units.
-------------------------------------------
Parameters Before Call After Call
-------------------------------------------
fd x /
req->opt.maxlen / /
req->opt.len x /
req->opt.buf x(x) /
req->flags x /
ret->opt.maxlen x /
ret->opt.len / x
ret->opt.buf x (x)
ret->flags / x
-------------------------------------------
Return Values
Upon successful completion, a value of 0 is returned. On failure, a value of -1 is returned, and t_errno is set to indicate the error.
Diagnostics
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.
[TACCES] The user does not have permission to negotiate the specified options.
[TBADOPT] The specified protocol options were in an incorrect format or contained illegal information.
[TBADFLAG] An invalid flag was specified.
[TBUFOVFLW] The number of bytes allowed for an incoming argument is not sufficient to store the value of that argument. The infor-
mation to be returned in ret is discarded.
[TNOTSUPPORT] This function is not supported by the current implementation of XTI.
[TSYSERR] A system error has occurred during execution of this function.
See Also
t_optmgmt(3xti)