Overview

INtime Connector Device (or XCNT) is a virtual device driver for INtime Network7 TCP/IP stack. Another application can connect to the device to send and receive Ethernet frames to and from the INtime network stack.

The most common use of XCNT is to share a single NIC device with Network7 stack and HPE application (figure below), but XCNT can be used for other applications.

The Connector Device in the INtime Network

The connector device will appear as “xcntn” in the INtime Network where n is the instance number. For example, the first connector device will be “xcnt0”.

Connector API Calls

The following calls are implemented in the XCNT API, which is called from the user application to send and receive packets from the network stack.

xcntOpenConnector	Establish a connection to the Connector Device
xcntCloseConnector	Close a connection to the device
xcntSendToConnector	Send an Ethernet frame to the device
xcntReceiveFromConnector	Receive an Ethernet frame from the device
xcntSetMediaStatus	Change the media status of the Connector Device

xcntOpenConnector

Establish a connection to the Connector Device

#include <xcnt_api.h>

typedef void* XCNTHANDLE;

int xcntOpenConnector(
    const char *cntName, 
    const BYTE *macAddr, 
    DWORD phyParams, 
    DWORD reserved,
    DWORD timeoutMs, 
    XCNTHANDLE *pHandle
);

Parameters:

cntName

The name of the connector device in the INtime Network. For example, the first connector device name will be “xcnt0”.

macAddr

Specifies the MAC address for the device. Usually, this is the MAC address of the corresponding HPE device.

phyParams

Specifies the link speed and link duplex mode. If XCNT_SPEED_NONE is specified, then the link status of the XCNT device is set to “down”, and XCNT will not forward packets sent from istack (xcntReceiveFromConnector will not get new packets). Once the device is open, then xcntSetMediaStatus can be used to change the media status later. The phyParams parameter (other than XCNT_SPEED_NONE) doesn’t affect the behavior of the connector device, but it changes the appearance of the device, i.e. the ifconfig command will display the speed and duplex mode specified by phyParams for the connector device.

reserved

Must be 0.

timeoutMs

Timeout value in milliseconds.

pHandle

A pointer to a handle.

Return Values

E_OK

success

E_PARAM

parameter error

E_MEM

out of physical memory

E_VMEM

out of virtual memory

E_TIME

timed out waiting for connector

xcntCloseConnector

Close a connection.

#include <xcnt_api.h>

int xcntCloseConnector( XCNTHANDLE *pHandle );

Parameters:

pHandle

A pointer to a handle previously returned from a call to xcntOpenConnector.

Return Values

E_OK

success

E_PARAM

parameter error

xcntSendToConnector

Send an Ethernet frame to the device.

#include <xcnt_api.h>

int xcntSendToConnector(
    XCNTHANDLE handle, 
    const BYTE *pBuffer, 
    DWORD bufferLength
);

Parameters:

handle

A handle previously returned from a call to xcntOpenConnector.

pBuffer

A pointer to an Ethernet frame data buffer.

bufferLength

Length of the frame including the Ethernet header (destination address, source address and ether-type) but excluding FCS (checksum).

Return Values

E_OK

success

E_PARAM

parameter error

E_STATE

out of synch with the stack

EH_GENERAL_PROTECTION

a fault occurred

xcntReceiveFromConnector

Receive an Ethernet frame from the device.

#include <xcnt_api.h>

int xcntReceiveFromConnector(
    XCNTHANDLE handle, 
    BYTE *pBuffer, 
    DWORD *pBufferLength, 
    DWORD timeoutMs
);

Parameters:

handle

A handle previously returned from a call to xcntOpenConnector.

pBuffer

A pointer to an Ethernet frame data buffer. The buffer must be at least 1514 bytes long.

pBufferLength

A pointer to a variable where the length of the returned frame will be stored. The length includes the Ethernet header (destination address, source address and ether-type) but excludes the FCS (checksum).

timeoutMs

A timeout value in milliseconds. The caller will be blocked until it receives a frame or the timeout expires.

Return Values

E_OK

success

E_PARAM

parameter error

E_TIME

timed out waiting for data

E_CANCELED

device closed

E_EMPTY_ENTRY

packet expected but none in ring buffer

EH_GENERAL_PROTECTION

a fault occurred

xcntSetMediaStatus

Change the Media Status for the connector device.

#include <xcnt_api.h>

int xcntSetMediaStatus(
    XCNTHANDLE handle, 
    DWORD phyParams
);

Parameters:

handle

A handle previously returned from a call to xcntOpenConnector.

phyParams

Specifies the link speed and link duplex mode. If XCNT_SPEED_NONE is specified, then the list status is changed to “down”.

Return Values

E_OK

success

E_PARAM

parameter error

Requirements