tfDnsUpdateSetCallback

Table of Contents >> Application Reference >> Dynamic DNS Update

#include <trsocket.h>

int tfDnsUpdateSetCallback	(
	ttDnsUpdateHandle dnsUpdateHandle,
	ttUserDnsUpdateCBFuncPtr userDnsUpdateFuncPtr,
	void * userDnsUpdateDataPtr
	);

Function Description

Set a pointer to a function that you provide for the purpose of event notification. This is only useful if you are using DNS in non-blocking mode (see tfDnsInit()). The callback function API is discussed on the ttUserDnsUpdateCBFuncPtr page.

This call is optional for non-blocking applications. By receiving notification of socket and timer events, you know exactly when you need to call tfDnsUpdateExecute().

Parameters

• dnsUpdateHandle

  A DNS update descriptor handle returned by tfDnsUpdateOpen().

• userDnsUpdateFuncPtr

  A pointer to a function that you provide of type ttUserDnsUpdateCBFuncPtr. This parameter can be NULL to remove a previously set value.

• userDnsUpdateDataPtr

  A pointer that will be passed as a parameter to userDnsUpdateFuncPtr. Treck does not use this pointer except to pass it to your callback function. Note: Pointers to local stack variables may go out of scope and become invalid by the time your callback function is called.

Returns

• TM_ENOERROR

  Success.

• TM_EINVAL

  Invalid descriptor handle.

• TM_EPERM

  Cannot change the descriptor while tfDnsUpdateSend() is in progress.

Table of Contents >> Application Reference >> Dynamic DNS Update