unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (SunOS-4.1.3)
Page:
Section:
Apropos / Subsearch:
optional field

T_GETINFO(3N)                                                    T_GETINFO(3N)



NAME
       t_getinfo - get protocol-specific service information

SYNOPSIS
       #include <&lt;tiuser.h>&gt;

       int t_getinfo(fd, info)
       int fd;
       struct t_info *info;

DESCRIPTION
       t_getinfo()  returns  the  current  characteristics  of  the underlying
       transport protocol associated with file descriptor fd.  The info struc-
       ture  is  used  to  return the same information returned by t_open(3N).
       t_getinfo() enables a transport user to access this information  during
       any phase of communication.

       This argument points to a t_info structure which contains the following
       members:
              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 an expedited transport service data unit (ETSDU) */
              long connect;  /* max amount of data allowed on connection establishment
                                   functions */
              long discon;   /* max amount of data allowed on t_snddis and t_rcvdis functions */
              long servtype; /* service type supported by the transport provider */

FIELDS
       The values of the fields have the following meanings:

       addr          A value greater than or equal to zero indicates the maxi-
                     mum  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 maxi-
                     mum  number  of  bytes  of protocol-specific options sup-
                     ported 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 spec-
                     ifies  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  expe-
                     dited data is not supported by the transport provider.

       connect       A value greater than or equal to zero specifies the maxi-
                     mum amount of data that may be associated with connection
                     establishment  functions;  a  value  of -1 specifies that
                     there is no limit on the amount of data sent during  con-
                     nection  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 maxi-
                     mum amount of data that may be associated with the t_snd-
                     dis(3N)  and t_rcvdis(3N) functions; a value of -1 speci-
                     fies 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  field  specifies  the service type supported by the
                     transport provider, as described below.

       If a transport user is concerned with protocol independence, the  above
       sizes  may  be  accessed  to determine how large the buffers must be to
       hold each piece of information.  Alternatively, the  t_alloc(3N)  func-
       tion  may be used to allocate these buffers.  An error will result if a
       transport user exceeds the allowed data  size  on  any  function.   The
       value  of  each field may change as a result of option negotiation, and
       t_getinfo() enables a user to retrieve the current characteristics.

RETURN VALUES
       The servtype field of info 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(3N)
                           will return -2 for the etsdu, connect,  and  discon
                           fields.

RETURN VALUES
       t_getinfo() returns 0 on success and -1 on failure.

ERRORS
       TBADF          The specified file descriptor does not refer to a trans-
                      port endpoint.

       TSYSERR        The function failed due to a system error and set  errno
                      to indicate the error.

SEE ALSO
       t_open(3N)

                                21 January 1990                  T_GETINFO(3N)