t_connect - Establish a connection with another transport
user
#include <xti.h>
int t_connect(
int fd,
struct t_call *sndcall,
struct t_call *rcvcall );
XTI Library (libxti.a)
Interfaces documented on this reference page conform to
industry standards as follows:
t_connect(): XNS4.0, XNS5.0
Refer to the standards(5) reference page for more information
about industry standards and associated tags.
The following table summarizes the relevance of input and
output parameters before and after t_connect() is called.
-------------------------------------------------
Parameters Before Call After Call
-------------------------------------------------
fd y n
sndcall->addr.maxlen n n
sndcall->addr.len y n
sndcall->addr.buf y(y) n
sndcall->opt.maxlen n n
sndcall->opt.len y n
sndcall->opt.buf y(y) n
sndcall->udata.maxlen n n
sndcall->udata.len y n
sndcall->udata.buf o(o) n
sndcall->sequence n n
rcvcall->addr.maxlen y n
rcvcall->addr.len n y
rcvcall->addr.buf o (o)
rcvcall->opt.maxlen y n
rcvcall->opt.len n y
rcvcall->opt.buf o (o)
rcvcall->udata.maxlen y n
rcvcall->udata.len n y
rcvcall->udata.buf o (o)
rcvcall->sequence n n
-------------------------------------------------
Notes to table: This is a meaningful parameter. This is
not a meaningful parameter. This is an optional parameter.
The content of the object pointed to by o is
optional. Specifies a file descriptor returned by the
t_open() function that identifies the local transport endpoint
where the connection will be established. Points to
a type t_call structure. The t_call structure pointed to
by the sndcall parameter provides information required by
the transport provider to establish a connection at the
transport endpoint specified by the fd parameter. The
t_call structure has the following four members: Specifies
protocol address parameters of the destination transport
user needed by the transport provider. The type netbuf
structure referenced by this member is defined in the
xti.h include file. This structure, which is used to
define buffer parameters explicitly, has the following
members: Specifies the maximum byte length of the data
buffer. Specifies the actual byte length of the data
written to the buffer. Points to the buffer location.
Specifies protocol-specific information needed by the
transport provider. Specifies user-data parameters passed
to the destination transport user. This parameter is not
meaningful.
The sndcall->addr.maxlen, sndcall->opt.maxlen, and
sndcall->udata.maxlen parameters have no meaning
when the t_connect() function is called.
When options are used, the sndcall->opt.buf parameter
must specify the established options structure
(such as isoco_options, isocl_options or
tcp_options). A transport user may choose not to
negotiate protocol options by setting the sndcall->opt.len
parameter to 0 (zero). When options
are not specified by the transport user, the transport
provider has the option of returning default
option values.
The amount of transport user data passed to the
destination transport user must not exceed the limits
specified by the transport provider as returned
to the info->connect parameter of the t_open() or
t_getinfo() function.
The sndcall->opt.len and sndcall->udata.len parameters
must be set before the t_connect() function is
called. Points to a type t_call structure. The
t_call structure pointed to by the rcvcall parameter
reserves storage for information associated
with the connection established at the transport
endpoint specified by the fd parameter. When rcvcall
is a null pointer, no data is returned to the
caller. The structure pointed to by rcvcall has the
following members: Specifies protocol address
parameters associated with the responding transport
endpoint. Specifies protocol-specific information
associated with the transport provider. Specifies
parameters for user data that may be optionally
returned to the caller from the destination transport
user. This parameter is not meaningful.
The rcvcall->addr.maxlen, rcvcall->opt.maxlen, and
rcvcall->udata.maxlen parameters must be set before
the t_connect() function is called.
When it is provided, the rcvcall()->udata.len
parameter specifies the actual destination user
user-data byte length and the data buffer pointed
to by rcvcall()->udata.buf contains destination
transport user data.
The t_connect() XTI function is a connection-oriented service
function issued by a transport user to request connection
to the specified destination transport user. By
default, this function executes in the synchronous operating
mode. In this mode, the t_connect() function waits
for the destination user to respond and the connection to
be set up before returning control to the transport user
who called this function.
When the transport endpoint, specified by the file
descriptor, has been previously opened with the O_NONBLOCK
option set in the t_open() or fcntl() function, the t_connect()
function executes in asynchronous mode and does not
wait for the transport user at the specified endpoint to
respond before returning control to the caller, but
returns a [TNODATA] error, which indicates that the connection
has not yet been established. In asynchronous
mode, use the t_rcvconnect() function to determine the
status of a connect request.
The t_connect() function uses type t_call and netbuf
structures, which are defined in the xti.h include file.
If the t_connect() function fails, t_errno may be set to
one of the following values: File descriptor fd does not
refer to a valid transport endpoint. The t_connect()
function was issued in the wrong sequence. Asynchronous
mode is indicated because O_NONBLOCK was set, but no data
is currently available from the transport provider. The
specified protocol address was in an incorrect format or
contained illegal information. The specified protocol
options were in an incorrect format or contained illegal
information The amount of user data specified was not
within the bounds allowed by the transport provider. The
user does not have permission to use the specified protocol
address or options. The number of bytes allocated for
incoming data is not sufficient for storage of that data.
In asynchronous mode only, the connect information normally
returned to the rcvcall was discarded. The transport
provider state was changed to T_DATAXFER. An asynchronous
event that requires immediate attention has occurred on
the transport endpoint specified by the fd parameter. A
system error occurred during execution of this function.
This function is not supported by the underlying transport
provider. This transport provider does not provide multiple
connections with the same local and remote addresses.
This error indicates that a connection already exists.
This error indicates that a communication problem has been
detected between XTI and the transport provider for which
there is no other suitable XTI(t_errno).
The t_connect() function can only be called in the T_IDLE
transport provider state.
Upon successful completion, a value of 0 (zero) is
returned. Otherwise, a value of -1 is returned and t_errno
is set to indicate an error.
Functions: fcntl(2), t_accept(3), t_alloc(3), t_getinfo(3), t_listen(3), t_open(3), t_optmgmt(3), t_rcvconnect(3)
Standards: standards(5).
Network Programmer's Guide
t_connect(3)
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