Real-Time Network Functions

This section summarizes the Real Time Network (RTN) function set. RTN functions are those functions provided by the RT-TCP/IP Protocol Stack and are available for use by an RT-TCP/IP NIC driver, an RT-TCP/IP filter, or an application. The RTN functions are exported by the stack and may be used by doing the following:

For RT-TCP/IP drivers or filters, link the driver with the RtTcpip.lib import library and include the rtnapi.h file in your driver source files.

NOTE: Linking the driver to the appropriate files satisfies the linking requirements for both drivers and filters. There is no need to explicitly link the filter.

For applications, include the RtTcpip.lib import library and the rtnapi.h file in the application source.

NOTE: These functions require the RT-TCP/IP Stack to run. When an application process calls one of these functions, we recommend using RtnIsStackOnline to ensure that the Stack is running. If these functions are called while the Stack is not started, an exception may occur.

NOTE: Real-Time Network functions cannot be called from a Windows executable file (.exe).

For detailed information about a function, click its link in the table below.

Real-Time Network Function	Description
RtnAddMultiRoute	First validates if it has received a proper multicast IPv4 address. Then it adds multicast IPv4 address to the routing table on the selected device. After allocating a new entry in the IGMP table, it then sends the IGMP report of the new entry.
RtnAttachProcessExitHandler	Registers an application's networking exit handler to allow an RTSS application to perform custom socket code cleanup when an application
RtnDecodePacket	Accesses various fields in the stack defined packet structure.
RtnDeleteCriticalLock	Frees any associated memory from a CriticalLock.
RtnDeleteMultiRoute	First validates if it has received a proper multicast IPv4 address. It then deletes the multicast IPv4 address from the routing table on the selected device.
RtnDisplayNbrCacheTable	Displays the neighbor cache entry, the neighboring node's IPv6 address, the corresponding link-layer address, and the state of the neighbor cache entry for the network device identifier.
RtnDisplayRoutingTable	Displays all static IPv4 and IPv6 routes from RT-TCP/IP stack’s forwarding database.
RtnEnterCriticalLock	Waits on the associated CriticalLock until no other thread is inside a RtnEnterCritcalLock RtnLeaveCriticalLock pairing.
RtnEnumPciCards	Calls the fnCheckPciCard function for every PCI card found within the system (or until fnCheckPciCard returns TRUE), and is used to locate a PCI NIC.
RtnGetDataLong	Retrieves the value placed at offset index of the network device pointed to by ndp.
RtnGetDeviceFromIpAddress	Converts a binary IP address in network byte order into the network device pointer for the particular device.
RtnGetDeviceName	Returns a pointer to the ASCII character name associated with this driver instance.
RtnGetDevicePtr	Gets the network device pointer associated with ASCII network device name.
RtnGetIpAddress	Returns the IP address associated with this device instance.
RtnGetMcastCount	Normally used in RtndIoctl to determine the multicast address count.
RtnGetMsPerTick	Returns the tick interval, in milliseconds per tick, that the stack timer is configured to use.
RtnGetPacket	Returns a pointer to an RT-TCP/IP Stack packet structure.
RtnIndicateStatus	Reports the status for an instance of the driver for the RTX64-converted NIC card.
RtnInitializeCriticalLock	Initializes a CriticalLock data structure.
RtnInstallStaticRoute	Installs a static IPv4 or IPv6 route in RT-TCP/IP stack’s forwarding database.
RtnIsDeviceOnline	Used to get the online status of a network device for link status monitoring.
RtnIsStackOnline	Used to get the online status of the RT-TCP/IP stack for link status monitoring.
RtnIOCTLDriver	Called when the filter requires that the driver configure certain NIC modes or characteristics.
RtnLeaveCriticalLock	Exits a CriticalLock section.
RtnNotifyRecv	Used to notify the stack that data has been received.
RtnReleaseProcessExitHandler	Removes an application's networking exit handler registered by the function RtnAttachProcessExitHandler.
RtnRemoveStaticRoute	Removes a static IPv4 or IPv6 route from RtTcpIP stack’s forwarding database.
RtnRequest	Forwards a request to the underlying driver to query the requested capabilities and/or statistics of the RTX64 converted NIC card.
RtnSetDataLong	Sets the value at offset index of the network device pointed to by ndp.
RtnSetDefaultGateway	Sets the gateway address (in the stack) for an instance of the driver.
RtnSetLinkAddress	Sets the hardware address (in the stack) for an instance of the driver.
RtnTransmitDone	Notifies the RT-TCP/IP Stack that the most recent packet handed to RtndTransmit should be returned to the stack buffer pool for reuse.