DNS.rar_DNS中继服务器_DNS服务器编程_dns 服务器_dns服务器_pudn dns server

// mydnsrelay.cpp : 定义控制台应用程序的入口点。 // #include <stdio.h> #include <stdlib.h> #include <winsock2.h> #include <windows.h> #include <time.h> #include <string> #include <iostream> #include <fstream> #include <iomanip> using namespace std; #pragma comment(lib, "Ws2_32.lib") #define DEF_DNS_ADDRESS "202.106.0.20" //外部DNS服务器地址 #define LOCAL_ADDRESS "127.0.0.1" //本地DNS服务器地址 #define DNS_PORT 53 //进行DNS服务的53端口 #define BUF_SIZE 512 #define LENGTH 1024 #define AMOUNT 300 #define NOTFOUND -1 //DNS报文首部 typedef struct DNSHeader { unsigned short ID; unsigned short Flags; unsigned short QuestNum; unsigned short AnswerNum; unsigned short AuthorNum; unsigned short AdditionNum; } DNSHDR, *pDNSHDR; //DNS域名解析表结构 typedef struct translate { string IP; //IP地址 string domain; //域名 } Translate; //ID转换表结构 typedef struct IDChange { unsigned short oldID; //原有ID BOOL done; //标记是否完成解析 SOCKADDR_IN client; //请求者套接字地址 } IDTransform; Translate DNS_table[AMOUNT]; //DNS域名解析表 IDTransform IDTransTable[AMOUNT]; //ID转换表 int IDcount = 0; //转换表中的条目个数 char url[LENGTH]; //域名 SYSTEMTIME sys; //系统时间 int Day, Hour, Minute, Second, Milliseconds;//保存系统时间的变量 //函数：获取域名解析表 int GetTable(char *tablePath) { int i=0, j, pos=0; string table[AMOUNT]; ifstream infile(tablePath, ios::in); //以读入方式打开文本文件 if(! infile) { cerr << "Open" << tablePath << "error!" <<endl; exit(1); } //每次从文件中读入一行，直至读到文件结束符为止 while (getline(infile, table[i]) && i < AMOUNT) i++; if (i == AMOUNT) cout << "The DNS table memory is full. " << endl; for (j = 0; j < i-1; j++) { pos = table[j].find(' '); if (pos > table[j].size()) cout << "The record is not in a correct format. " << endl; else { DNS_table[j].IP = table[j].substr(0, pos); DNS_table[j].domain = table[j].substr(pos+1); } } infile.close(); //关闭文件 cout << "Load records succeed. " << endl; return i-1; //返回域名解析表中条目个数 } //函数：获取DNS请求中的域名 void GetUrl(char *recvbuf, int recvnum)//字符串、字符串长度 { char urlname[LENGTH]; int i = 0, j, k = 0; memset(url, 0, LENGTH); memcpy(urlname, &(recvbuf[sizeof(DNSHDR)]), recvnum-16); //获取请求报文中的域名表示 int len = strlen(urlname); //域名转换 while (i < len) { if (urlname[i] > 0 && urlname[i] <= 63) for (j = urlname[i], i++; j > 0; j--, i++, k++) url[k] = urlname[i]; if (urlname[i] != 0) { url[k] = '.'; k++; } } url[k] = '\0'; } //函数：判断是否在表中找到DNS请求中的域名，找到返回下标 int IsFind(char* url, int num) { int find = NOTFOUND; char* domain; for (int i = 0; i < num; i++) { domain = (char *)DNS_table[i].domain.c_str(); if (strcmp(domain, url) == 0) { //找到 find = i; break; } } return find; } //函数：将请求ID转换为新的ID，并将信息写入ID转换表中 unsigned short RegisterNewID (unsigned short oID, SOCKADDR_IN temp, BOOL ifdone) { if(IDcount == AMOUNT) IDcount = 0; //srand(time(NULL)); IDTransTable[IDcount].oldID = oID; IDTransTable[IDcount].client = temp; IDTransTable[IDcount].done = ifdone; IDcount++; return (unsigned short)(IDcount-1); //以表中下标作为新的ID } //函数：打印 时间 newID 功能 域名 IP void DisplayInfo(unsigned short newID, int find) { //打印时间 GetLocalTime( &sys ); if(sys.wMilliseconds >= Milliseconds) { cout << setiosflags(ios::right) << setw(7) << setfill(' ') << (((sys.wDay - Day) * 24 + sys.wHour - Hour) * 60 + sys.wMinute - Minute) * 60 + sys.wSecond - Second;//设置宽度为7，right对齐方式 cout << '.' << setiosflags(ios::right) << setw(3) << setfill('0') << sys.wMilliseconds - Milliseconds; } else { cout << setiosflags(ios::right) << setw(7) << setfill(' ') << (((sys.wDay - Day) * 24 + sys.wHour - Hour) * 60 + sys.wMinute - Minute) * 60 + sys.wSecond - Second - 1;//设置宽度为7，right对齐方式 cout << '.' << setiosflags(ios::right) << setw(3) << setfill('0') << 1000 + sys.wMilliseconds - Milliseconds; } cout << " "; //打印转换后新的ID cout.setf(ios::left); cout << setiosflags(ios::left) << setw(4) << setfill(' ') << newID; cout << " "; //在表中没有找到DNS请求中的域名 if (find == NOTFOUND) { //中继功能 cout.setf(ios::left); cout << setiosflags(ios::left) << setw(6) << setfill(' ') << "中继"; cout << " "; //打印域名 cout.setf(ios::left); cout << setiosflags(ios::left) << setw(20) << setfill(' ') << url; cout << " "; cout.setf(ios::left); cout << setiosflags(ios::left) << setw(20) << setfill(' ') << endl; } //在表中找到DNS请求中的域名 else { if(DNS_table[find].IP == "0.0.0.0") //不良网站拦截 { //屏蔽功能 cout.setf(ios::left); cout << setiosflags(ios::left) << setw(6) << setfill(' ') << "屏蔽"; cout << " "; //打印域名(加*) cout.setf(ios::left); cout << "*" << setiosflags(ios::left) << setw(19) << setfill(' ') << url; cout << " "; cout.setf(ios::left); cout << setiosflags(ios::left) << setw(20) << setfill(' ') << endl; } //检索结果为普通IP地址，则向客户返回这个地址 else { //服务器功能 cout.setf(ios::left); cout << setiosflags(ios::left) << setw(6) << setfill(' ') << "服务器"; cout << " "; //打印域名 cout.setf(ios::left); cout << "*" << setiosflags(ios::left) << setw(19) << setfill(' ') << url; cout << " "; //打印IP cout.setf(ios::left); cout << setiosflags(ios::left) << setw(20) << setfill(' ') << DNS_table[find].IP << endl; } } } int main(int argc, char** argv) { WSADATA wsaData; SOCKET socketServer, socketLocal; //本地DNS和外部DNS两个套接字 SOCKADDR_IN serverName, clientName, localName; //本地DNS、外部DNS和请求端三个网络套接字地址 char sendbuf[BUF_SIZE]; char recvbuf[BUF_SIZE]; char tablePath[100]; char outerDns[16]; int iLen_cli, iSend, iRecv; int num; fd_set fdset;//套接字集合 struct timeval t1; if (argc == 1) { strcpy(outerDns, DEF_DNS_ADDRESS); strcpy(tablePath, "D:\\document\\大学课程\\DNS\\dnsrelay.txt"); } else if (argc == 2) { strcpy(outerDns, argv[1]); strcpy(tablePath, "D:\\document\\大学课程\\DNS\\dnsrelay.txt"); } else if (argc == 3) { strcpy(outerDns, argv[1]); strcpy(tablePath, argv[2]); } num = GetTable(tablePath); //获取域名解析表 //保存系统的时间 GetLocalTime(&sys); Day = sys.wDay; Hour = sys.wHour; Minute = sys.wMinute; Second = sys.wSecond; Milliseconds = sys.wMilliseconds; for (int i=0; i < AMOUNT; i++) { //初始化ID转换表 IDTransTable[i].oldID = 0; IDTransTable[i].done = FALSE; memset(&(IDTransTable[i].client), 0, sizeof(SOCKADDR_IN)); } WSAStartup(MAKEWORD(2,2), &wsaData); //初始化ws2_32.dll动态链接库 //创建本地DNS和外部DNS套接字 socketServer = socket(AF_INET, SOCK_DGRAM, 0); socketLocal = socket(AF_INET, SOCK_DGRAM, 0); //设置本地DNS和外部DNS两个套接字 localName.sin_family = AF_INET; localName.sin_port = htons(DNS_PORT); localName.sin_addr.s_addr = inet_addr(LOCAL_ADDRESS);//(LOCAL_ADDRESS);INADDR_ANY serverName.sin_family = AF_INET; serverName.sin_port = htons(DNS_PORT); serverName.sin_addr.s_addr = inet_addr(outerDns); const char on = 1; if(setsockopt(socketLocal,SOL_SOCKET,SO_REUSEADDR,&on,sizeof(on))) cout << "setsockopt failed"; //绑定本地DNS服务器地址 if (bind(socketLocal, (SOCKADDR*)&localName, sizeof(localName))) { cout << "Binding Port 53 failed." << endl; exit(1); } else cout << "Binding Port 53 succeed." << endl; //本地DNS服务器的具体操作 while (1) {