t_accept(3) Library Functions Manual t_accept(3)
NAME
t_accept() - accept a connect request
SYNOPSIS
DESCRIPTION
The function is issued by a transport user to accept a connect request. fd identifies the local transport endpoint where the connect indi-
cation arrived. resfd specifies the local transport endpoint where the connection is to be established. call contains information
required by the transport provider to complete the connection. The parameter call points to a structure which contains the following mem-
bers:
The structure is defined in the or header file. This structure, which is used to define buffer parameters, has the following members:
maximum byte length of the data buffer
actual byte length of data written to buffer
points to buffer location
In call, the addr, opt, udata, and sequence parameters are explained here. addr is the protocol address of the calling transport user.
opt indicates any options associated with the connection. For XTI over the OSI transport provider, this should point to a struct of type
udata points to any user data to be returned to the caller. sequence is the value returned by that uniquely associates the response with a
previously received connect indication. The address of the caller, addr, may be null (length zero). When addr is not null, then it may
optionally be checked by XTI.
A transport user may accept a connection on either the same, or on a different, local transport endpoint than the one on which the connect
indication arrived. Before the connection can be accepted on the same endpoint (resfd==fd), the user must have responded to any previous
connect indications received on that transport endpoint (via or Otherwise, will fail and set to [TINDOUT].
If a different transport endpoint is specified (resfd!=fd), then the user may or may not choose to bind the endpoint before is issued. If
the endpoint is not bound prior to the then the transport provider will automatically bind it to the same protocol address fd is bound to.
If the transport user chooses to bind the endpoint, it must be bound to a protocol address with a qlen of zero and must be in the state
before the is issued.
The call to will fail with set to [TLOOK] if there are indications for example, connect or disconnect waiting to be received on the end-
point fd.
The udata argument enables the called transport user to send user data to the caller. The amount of user data must not exceed the limits
supported by the transport provider as returned in the connect field of the info argument of or If the len field of udata is zero, no data
will be sent to the caller. All the maxlen fields are meaningless.
When the user does not indicate any option (call->opt.len = 0), it is assumed that the connection is to be accepted unconditionally. The
transport provider may choose options other than the defaults to ensure that the connection is accepted successfully.
Valid States
fd:
resfd (fd != resfd):
Caveats
There may be transport provider-specific restrictions on address binding.
Some transport providers do not differentiate between a connect indication and the connection itself. If the connection has already been
established after a successful return of will assign the existing connection to the transport endpoint specified by resfd.
Fork Safety
is not fork-safe.
RETURN VALUE
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned, and is set to indicate the error.
ERRORS
On failure, is set to one of the following:
[TBADF] The file descriptor, fd or resfd, does not refer to a transport endpoint, or the user is illegally accepting a connec-
tion of the same transport endpoint on which the connect indication arrived.
[TOUTSTATE] The function was issued in the wrong sequence on the transport endpoint referenced by fd, or the transport endpoint
referred to by resfd is not in the appropriate state.
[TACCES] The user does not have permission to accept a connection on the responding transport endpoint or use the specified
options.
[TBADOPT] The specified options were in an incorrect format or contained illegal information.
[TBADDATA] The amount of user data specified was not within the bounds allowed by the transport provider.
[TBADADDR] The specified protocol address was in an incorrect format or contained illegal information.
[TBADSEQ] An invalid sequence number was specified.
[TLOOK] An asynchronous event has occurred on the transport endpoint referenced by fd and requires immediate attention.
[TNOTSUPPORT] This function is not supported by the underlying transport provider.
[TSYSERR] A system error has occurred during execution of this function.
[TINDOUT] The function was called with fd==resfd but there are outstanding connection indications on the endpoint. Those other
connection indications must be handled either by rejecting them via or accepting them on a different endpoint via
[TPROVMISTMATCH] (XTI only) The file descriptors fd and resfd do not refer to the same transport provider.
[TRESQLEN] The endpoint referenced by resfd (where resfd != fd) was bound to a protocol address with a qlen that is greater than
zero.
[TPROTO] (XTI only) This error indicates that a communication problem has been detected between XTI and the transport provider
for which there is no other suitable XTI (
[TRESADDR] This transport provider requires both fd and resfd to be bound to the same address. This error results if they are
not.
FILES
XTI data structures
XTI data structures
TLI data structures
SEE ALSO
t_connect(3), t_getstate(3), t_listen(3), t_open(3), t_rcvconnect(3), thread_safety(5).
STANDARDS CONFORMANCE
t_accept(3)