//DNS?Query?Program
//Author?:?Prasshhant?Pugalia?（prasshhant.p@gmail.com）
//Dated??:?26/2/2007

//Header?Files
#include?“winsock2.h“
#include?“windows.h“
#include?“stdio.h“
#include?“conio.h“

#pragma?comment（lib“ws2_32.lib“）???//Winsock?Library

//List?of?DNS?Servers?registered?on?the?system
char?dns_servers[10][100];

//Type?field?of?Query?and?Answer
#define?T_A		????1		/*?host?address?*/
#define?T_NS		2		/*?authoritative?server?*/
#define?T_CNAME		5		/*?canonical?name?*/
#define?T_SOA		6		/*?start?of?authority?zone?*/
#define?T_PTR		12		/*?domain?name?pointer?*/
#define?T_MX		15		/*?mail?routing?information?*/

//Function?Prototypes
void???????????ngethostbyname????????????????（unsigned?char*）;
void???????????ChangetoDnsNameFormat?????????（unsigned?char*unsigned?char*）;
unsigned?char*?ReadName??????????????????????（unsigned?char*unsigned?char*int*）;
void???????????RetrieveDnsServersFromRegistry（void）;
unsigned?char*?PrepareDnsQueryPacket?????????（unsigned?char*）;

//DNS?header?structure
struct?DNS_HEADER
{
	unsigned	short?id;		????//?identification?number
	
	unsigned	char?rd?????:1;		//?recursion?desired
	unsigned	char?tc?????:1;		//?truncated?message
	unsigned	char?aa?????:1;		//?authoritive?answer
	unsigned	char?opcode?:4;	????//?purpose?of?message
	unsigned	char?qr?????:1;		//?query/response?flag
	
	unsigned	char?rcode??:4;	????//?response?code
	unsigned	char?cd?????:1;	????//?checking?disabled
	unsigned	char?ad?????:1;	????//?authenticated?data
	unsigned	char?z??????:1;		//?its?z!?reserved
	unsigned	char?ra?????:1;		//?recursion?available
	
	unsigned????short?q_count;	????//?number?of?question?entries
	unsigned	short?ans_count;	//?number?of?answer?entries
	unsigned	short?auth_count;	//?number?of?authority?entries
	unsigned	short?add_count;	//?number?of?resource?entries
};


//Constant?sized?fields?of?query?structure
struct?QUESTION
{
	unsigned?short?qtype;
	unsigned?short?qclass;
};


//Constant?sized?fields?of?the?resource?record?structure
#pragma?pack（push?1）
struct??R_DATA
{
	unsigned?short?type;
	unsigned?short?_class;
	unsigned?int???ttl;
	unsigned?short?data_len;
};
#pragma?pack（pop）


//Pointers?to?resource?record?contents
struct?RES_RECORD
{
	unsigned?char??*name;
	struct?R_DATA??*resource;
	unsigned?char??*rdata;
};

//Structure?of?a?Query
typedef?struct
{
	unsigned?char?*name;
	struct?QUESTION??????*ques;
}?QUERY;


int?main（）??//do?you?know?what?is?int?main（）??
{
	unsigned?char?hostname[100];
	
	WSADATA?firstsock;
	
	RetrieveDnsServersFromRegistry（）;

	printf（“\nInitialising?Winsock...“）;
	if?（WSAStartup（MAKEWORD（22）&firstsock）?!=?0）
	{
		printf（“Failed.?Error?Code?:?%d“WSAGetLastError（））;
		return?1;
	}?
	printf（“Initialised.“）;
????
	printf（“\nEnter?Hostname?to?Lookup?:?“）;
	gets（（char*）hostname）;
????ngethostbyname（hostname）;
	
	_getch（）;
	return?0;
}

void?ngethostbyname（unsigned?char?*host）
{
	unsigne

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件???????11388??2007-07-24?12:21??main.c
?????文件????????4286??2007-02-26?20:50??dns.dsp
?????文件?????????531??2007-02-26?19:54??dns.dsw