t_bind - bind an address to a transport endpoint
int t_bind(fd, req, ret)
struct t_bind *req;
struct t_bind *ret;
t_bind() associates a protocol address with the transport endpoint
specified by fd and activates that transport endpoint. In connection
mode, the transport provider may begin accepting or requesting connec-
tions on the transport endpoint. In connectionless mode, the transport
user may send or receive data units through the transport endpoint.
The req and ret arguments point to a t_bind() structure containing the
struct netbuf addr;
The maxlen, len, and buf members of the netbuf structure are described
in t_accept(3N). The addr field of the t_bind() structure specifies a
protocol address and the qlen field is used to indicate the maximum
number of outstanding connect indications.
req is used to request that an address, represented by the netbuf
structure, be bound to the given transport endpoint. len specifies the
number of bytes in the address and buf points to the address buffer.
maxlen has no meaning for the req argument. On return, ret contains
the address that the transport provider actually bound to the transport
endpoint; this may be different from the address specified by the user
in req. In ret, the user specifies maxlen which is the maximum size of
the address buffer and buf which points to the buffer where the address
is to be placed. On return, len specifies the number of bytes in the
bound address and buf points to the bound address. If maxlen is not
large enough to hold the returned address, an error will result.
If the requested address is not available, or if no address is speci-
fied in req (the len field of addr in req is 0) the transport provider
will assign an appropriate address to be bound, and will return that
address in the addr field of ret. The user can compare the addresses
in req and ret to determine whether the transport provider bound the
transport endpoint to a different address than that requested.
req may be NULL if the user does not wish to specify an address to be
bound. Here, the value of qlen is assumed to be 0, and the transport
provider must assign an address to the transport endpoint. Similarly,
ret may be NULL if the user does not care what address was bound by the
transport provider and is not interested in the negotiated value of
qlen. It is valid to set req and ret to NULL for the same call, in
which case the transport provider chooses the address to bind to the
transport endpoint and does not return that information to the user.
The qlen field has meaning only when initializing a connection-mode
service. It specifies the number of outstanding connect indications
the transport provider should support for the given transport endpoint.
An outstanding connect indication is one that has been passed to the
transport user by the transport provider. A value of qlen greater than
0 is only meaningful when issued by a passive transport user that
expects other users to call it. The value of qlen will be negotiated
by the transport provider and may be changed if the transport provider
cannot support the specified number of outstanding connect indications.
On return, the qlen field in ret will contain the negotiated value.
t_bind() allows more than one transport endpoint to be bound to the
same protocol address (however, the transport provider must support
this capability also), but binding more than one protocol address to
the same transport endpoint is not allowed. If a user binds more than
one transport endpoint to the same protocol address, only one endpoint
can be used to listen for connect indications associated with that pro-
tocol address. In other words, only one t_bind() for a given protocol
address may specify a value of qlen greater than 0. In this way, the
transport provider can identify which transport endpoint should be
notified of an incoming connect indication. If a user attempts to bind
a protocol address to a second transport endpoint with a value of qlen
greater than 0, the transport provider will assign another address to
be bound to that endpoint. If a user accepts a connection on the
transport endpoint that is being used as the listening endpoint, the
bound protocol address will be found to be busy for the duration of
that connection. No other transport endpoints may be bound for listen-
ing while that initial listening endpoint is in the data transfer
phase. This will prevent more than one transport endpoint bound to the
same protocol address from accepting connect indications.
0 on success.
-1 on failure and sets t_errno to indicate the error.
TACCES The user does not have permission to use the speci-
TBADADDR The specified protocol address was in an incorrect
format or contained illegal information.
TBADF The specified file descriptor does not refer to a
TBUFOVFLW The number of bytes allowed for an incoming argu-
ment is not sufficient to store the value of that
argument. The transport provider's state will
change to T_IDLE and the information to be returned
in ret will be discarded.
TNOADDR The transport provider could not allocate an
TOUTSTATE The function was issued in the wrong sequence.
TSYSERR The function failed due to a system error and set
errno to indicate the error.
intro(3), t_open(3N), t_optmgmt(3N), t_unbind(3N)
21 January 1990 T_BIND(3N)