DnsQuery_A function (windns.h)
The DnsQuery function type is the generic query interface to the DNS namespace, and provides application developers with a DNS query resolution interface. Like many DNS functions, the DnsQuery function type is implemented in multiple forms to facilitate different character encoding. Based on the character encoding involved, use one of the following functions:
- DnsQuery_A (for ANSI encoding)
- DnsQuery_W (for Unicode encoding)
- DnsQuery_UTF8 (for UTF-8 encoding)
Syntax
DNS_STATUS DnsQuery_A(
[in] PCSTR pszName,
[in] WORD wType,
[in] DWORD Options,
[in, out, optional] PVOID pExtra,
[out, optional] PDNS_RECORD *ppQueryResults,
[out, optional] PVOID *pReserved
);
Parameters
[in] pszName
A pointer to a string that represents the DNS name to query.
[in] wType
A value that represents the Resource Record (RR)DNS Record Type that is queried. wType determines the format of data pointed to by ppQueryResultsSet. For example, if the value of wType is DNS_TYPE_A, the format of data pointed to by ppQueryResultsSet is DNS_A_DATA.
[in] Options
A value that contains a bitmap of DNS Query Options to use in the DNS query. Options can be combined and all options override DNS_QUERY_STANDARD.
[in, out, optional] pExtra
This parameter is reserved for future use and must be set to NULL.
[out, optional] ppQueryResults
Optional. A pointer to a pointer that points to the list of RRs that comprise the response. For more information, see the Remarks section.
[out, optional] pReserved
This parameter is reserved for future use and must be set to NULL.
Return value
Returns success confirmation upon successful completion. Otherwise, returns the appropriate DNS-specific error code as defined in Winerror.h.
Remarks
Applications that call the DnsQuery function build a query using a fully qualified DNS name and Resource Record (RR) type, and set query options depending on the type of service desired. When the DNS_QUERY_STANDARD option is set, DNS uses the resolver cache, queries first with UDP, then retries with TCP if the response is truncated, and requests that the server to perform recursive resolution on behalf of the client to resolve the query.
Applications must free returned RR sets with the DnsRecordListFree function.
If the lpstrName parameter is set to NULL, the DnsQuery function fails with the error INVALID_PARAMETER.
Requirements
Requirement | Value |
---|---|
Minimum supported client | Windows 2000 Professional [desktop apps only] |
Minimum supported server | Windows 2000 Server [desktop apps only] |
Target Platform | Windows |
Header | windns.h |
Library | Dnsapi.lib |
DLL | Dnsapi.dll |