| Standards / Extensions | C or C++ | Dependencies |
|---|---|---|
| XPG4.2 | both |
#define _XOPEN_SOURCE_EXTENDED 1
#include <xti.h>
int t_connect(int fd, struct t_call *call, struct t_call *rcvcall); struct netbuf addr;
struct netbuf opt;
struct netbuf udata;
int sequence;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. sequence has no meaning for this function.
On return, in rcvcall, addr contains the protocol address associated with the responding transport endpoint. opt represents 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. sequence has no meaning for this function.
The opt argument permits users to define the options that may be passed to the transport provider. See the discussion of supported options in t_optmgmt(). 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.
If used, sndcall->opt.buf must point to a buffer with the corresponding options. The maxlen and buf fields of the netbuf structure pointed by rcvcall->addr and rcvcall->opt must be set before the call.
Since passing of userdata over a connection request is not supported under TCP, the udata argument is always meaningless.
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 a NULL pointer, in which case no information is given to the user on return from t_connect().
By default, t_connect() executes in synchronous mode, and will wait for the destination user's response before returning control to the local user. A successful return (that is, return value of zero) indicates that the requested connection has been established. However, if O_NONBLOCK is set (using t_open() or fcntl() ), t_connect() executes in asynchronous 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 t_errno set to TNODATA to indicate that the connection 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. The t_rcvconnect() function is used in conjunction with t_connect() to determine the status of the requested connection.
When a synchronous t_connect() call is interrupted by the arrival of a signal, the state of the corresponding transport endpoint is T_OUTCON, allowing a further call to either t_rcvconnect(), t_rcvdis() or t_snddis().
Valid states: T_IDLE
If successful, t_connect() returns 0.