Inside Macintosh: Networking With Open Transport / Part 2 - Open Transport Reference

Chapter 29 - TCP/IP Services Reference / Constants and Data Types

DNS Query Information Structure

The DNS query information structure is used by the TCP/IP service provider to return answers to DNS queries made using the OTInetQuery function. The DNS query information structure is defined by the DNSQueryInfo data type. For additional information about the constant values for the DNSQueryInfo fields, see the DNS Requests for Comments (RFCs), available over the World Wide Web.

struct DNSQueryInfo {
   UInt16          qType;
   UInt16          qClass;
   UInt32          ttl;
   InetDomainName  name;
   UInt16          responseType;
   UInt16          resourceLen;
   char            resourceData[4];
};
typedef struct DNSQueryInfo DNSQueryInfo;

Field Description

qType

The numerical value of the DNS resource record type, such as MX and PTR, for which you wish to query.

qClass

The numerical value of the DNS record class, such as Inet and Hesio, for which you wish to query.

ttl

An integer indicating the DNS resource record's time to live (in seconds).

name

The fully qualified domain name or address for which you made the query.

responseType

The type of response.

resourceLen

The actual length of the resource data returned.

resourceData

The resource data that is returned. This is at least 4 bytes long, and is usually longer.

See the Internet Standard for a definitive list of values for the qType, qClass, and respnoseType fields, and for a definition of the format of the resource data.