t_info --
TLI and XTI transport protocol structure
Syntax
#include <sys/tiuser> /* TLI only */
#include <xti.h> /* XTI only */
Description
The t_info structure contains the following members:
Member
Description
long addr;
/* max size of the transport protocol address */
long options;
/* max number of bytes of protocol-specific options */
long tsdu;
/* max size of a transport service data unit (TSDU) */
long etsdu;
/* max size of expedited transport service data */
/* unit (ETSDU) */
long connect;
/* max data allowed on connection establishment */
long discon;
/* max data allowed for t_snddis and t_rcvdis */
long servtype;
/* service type supported by the transport provider */
The values of the members have the following meanings:
addr
A value greater than or equal to zero indicates the maximum
size of a transport protocol address; a value of -1 specifies
that there is no limit on the address size; and a value of -2
specifies that the transport provider does not provide user
access to transport protocol addresses.
options
A value greater than or equal to zero indicates the maximum
number of bytes of protocol-specific options supported by the
provider; a value of -1 specifies that there is no limit on the
option size; and a value of -2 specifies that the transport provider
does not support user-settable options.
tsdu
A value greater than zero specifies the maximum size of a transport service
data unit (TSDU); a value of zero specifies that the
transport provider does not support the concept of
TSDU, although it does support the sending of a data stream with no
logical boundaries preserved across a connection;
a value of -1 specifies that there is no limit on the size of a
TSDU; and a value of -2 specifies that the transfer of
normal data is not supported by the transport provider.
etsdu
A value greater than zero specifies the maximum size of an Expedited Transport
Service Data Unit (ETSDU);
a value of zero specifies that the
transport provider does not support the concept of ETSDU,
although it does support the sending of an expedited data stream with no
logical boundaries preserved across a connection;
a value of -1 specifies that there is no limit on the size of an
ETSDU;
and a value of -2 specifies that the transfer of expedited data is
not supported by the transport provider.
connect
A value greater than or equal to zero specifies
the maximum amount of data that can be associated with
connection establishment functions;
a value of -1 specifies that there is no limit on the amount of data
sent during connection establishment;
and a value of -2 specifies that the transport provider does not
allow data to be sent with connection establishment functions.
discon
A value greater than or equal to zero specifies
the maximum amount of data that can be associated with the
t_snddis(NET)
and
t_rcvdis(NET)
functions;
a value of -1 specifies that there is no limit on the amount of data
sent with these abortive release functions;
and a value of -2 specifies that the transport provider does not
allow data to be sent with the abortive release functions.
servtype
This member specifies the service type supported by the transport provider,
as described below.
If a transport user is concerned with protocol independence, the above
sizes can be accessed to determine how large the buffers must be
to hold each piece of information. Alternatively, the
t_alloc(NET)
function can be used to allocate these buffers.
An error results if a transport user exceeds the allowed
data size on any function.
The value of each member can change as a result of option negotiation, and
t_getinfo(NET)
enables a user to retrieve the current characteristics.
The servtype member of t_info structure
may specify one of the following values on return:
T_COTS
The transport provider supports a connection-mode service but
does not support the optional orderly release facility.
T_COTS_ORD
The transport provider supports a connection-mode service with
the optional orderly release facility.
T_CLTS
The transport provider supports a connectionless-mode service.
For this service type,
t_open(NET)
returns -2 for etsdu, connect, and discon.