t_connect(3N) t_connect(3N)
NAME
tconnect - establish a connection with another transport user
SYNOPSIS
#include <sys/tiuser.h>
int tconnect(int fd, struct tcall *sndcall,
struct tcall *rcvcall);
DESCRIPTION
This function enables a transport user to request a connection to the
specified destination transport user. fd identifies the local trans-
port endpoint where communication will be established, while sndcall
and rcvcall point to a tcall structure that contains the following
members:
struct netbuf addr;
struct netbuf opt;
struct netbuf udata;
int sequence;
sndcall specifies information needed by the transport provider to
establish a connection and rcvcall specifies information that is asso-
ciated with the newly established connection.
In sndcall, addr specifies the protocol address of the destination
transport user, opt presents any protocol-specific information that
might be needed by the transport provider, udata points to optional
user data that may be passed to the destination transport user during
connection establishment, and sequence has no meaning for this func-
tion.
On return in rcvcall, addr returns the protocol address associated
with the responding transport endpoint, opt presents any protocol-
specific information associated with the connection, udata points to
optional user data that may be returned by the destination transport
user during connection establishment, and sequence has no meaning for
this function.
The opt argument implies no structure on the options that may be
passed to the transport provider. The transport provider is free to
specify the structure of any options passed to it. These options are
specific to the underlying protocol of the transport provider. The
user may choose not to negotiate protocol options by setting the len
field of opt to zero. In this case, the provider may use default
options.
The udata argument enables the caller to pass user data to the desti-
nation transport user and receive user data from the destination user
during connection establishment. However, 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 topen(3N) or
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t_connect(3N) t_connect(3N)
tgetinfo(3N). If the len field of udata is zero in sndcall, no data
will be sent to the destination transport user.
On return, the addr, opt, and udata fields of rcvcall will be updated
to reflect values associated with the connection. Thus, the maxlen
field of each argument must be set before issuing this function to
indicate the maximum size of the buffer for each. However, rcvcall may
be NULL, in which case no information is given to the user on return
from tconnect.
By default, tconnect executes in synchronous mode, and will wait for
the destination user's response before returning control to the local
user. A successful return (i.e., return value of zero) indicates that
the requested connection has been established. However, if ONDELAY or
ONONBLOCK is set (via topen or fcntl), tconnect executes in asyn-
chronous mode. In this case, the call will not wait for the remote
user's response, but will return control immediately to the local user
and return -1 with terrno set to TNODATA to indicate that the connec-
tion has not yet been established. In this way, the function simply
initiates the connection establishment procedure by sending a connect
request to the destination transport user.
On failure, terrno may be 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.
TNODATA ONDELAY or ONONBLOCK was set, so the function suc-
cessfully initiated the connection establishment pro-
cedure, but did not wait for a response from the
remote user.
TBADADDR The specified protocol address was in an incorrect
format or contained illegal information.
TBADOPT The specified protocol 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.
TACCES The user does not have permission to use the specified
address or options.
TBUFOVFLW The number of bytes allocated for an incoming argument
is not sufficient to store the value of that argument.
If executed in synchronous mode, the provider's state,
as seen by the user, changes to TDATAXFER, and the
connect indication information to be returned in
rcvcall is discarded.
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t_connect(3N) t_connect(3N)
TLOOK An asynchronous event has occurred on this transport
endpoint 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.
DIAGNOSTICS
tconnect returns 0 on success and -1 on failure and terrno is set to
indicate the error.
SEE ALSO
taccept(3N), tgetinfo(3N), tlisten(3N), topen(3N), toptmgmt(3N),
trcvconnect(3N).
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