/// <summary>
/// 响应一个没有记录
/// </summary>
/// <param name="dnsPack">原始数据</param>
/// <param name="client">客户端节点</param>
private void ResponsenNonDomain(DnsPack dnsPack, EndPoint client)
{
//标记为响应
dnsPack.QR = 1;
//标记位未找到
dnsPack.Rcode = 3;
//响应客户端
server.SendTo(dnsPack.ToBytes(), client);
}
/// <summary>
/// 响应一个没有记录
/// </summary>
/// <param name="dnsPack">原始数据</param>
/// <param name="client">客户端节点</param>
private void ResponsenNonDomain(byte[] dnsPack, EndPoint client)
{
DnsPack dnsPack_ = new DnsPack(dnsPack);
//标记为响应
dnsPack_.QR = 1;
//标记位未找到
dnsPack_.Rcode = 3;
//响应客户端
server.SendTo(dnsPack_.ToBytes(), client);
}
/// <summary>
/// 响应DNS请求
/// </summary>
/// <param name="DnsPack">响应数据</param>
/// <param name="client">客户端节点</param>
private void Response(DnsPack dnsPack, EndPoint client)
{
//响应并记录缓存
server.SendTo(dnsPack.ToBytes(), client);
//如果有解析到记录，则缓存数据
//实际应该针对每条资源的TLL缓存，这里直接缓存了整个数据包
if (dnsPack.Rcode == 0)
{
if (dnsPack.ResouceRecords.Count > 0 ||
dnsPack.GrantResouces.Count > 0 ||
dnsPack.AdditResouces.Count > 0)
{
dataBase.WriteCache(dnsPack);
}
}
//触发事件，修改统计数值
RelaySum++;
SumChanged(this, EventArgs.Empty);
}
/// <summary>
/// 域名解析过程
/// </summary>
/// <param name="data"></param>
private void Working(WorkingData data)
{
DnsPack dnsPack = new DnsPack(data.dnsPack);
EndPoint client = data.client;
//本机PTR指针
if (dnsPack.QR == 0 && dnsPack.Opcode == 0 && dnsPack.QueryRecords.Count >= 1)
{
if (dnsPack.QueryRecords[0].QueryType == QueryType.PTR)
{
string hostName = Dns.GetHostName();
IPAddress[] localhost = Dns.GetHostAddresses(hostName);
foreach (IPAddress IP in localhost)
{
if (IP.AddressFamily == AddressFamily.InterNetwork)
{
byte[] ip = IP.GetAddressBytes();
string ptrstr = string.Format("{3}.{2}.{1}.{0}.{4}", ip[0], ip[1], ip[2], ip[3], @"in-addr.arpa");
if (dnsPack.QueryRecords[0].QueryName == ptrstr ||
dnsPack.QueryRecords[0].QueryName == @"1.0.0.127.in-addr.arpa")
{
dnsPack.QR = 1; dnsPack.RA = 1; dnsPack.RD = 1;
dnsPack.ResouceRecords = new List <ResouceRecord> {
new ResouceRecord {
Point = IPAddress.HostToNetworkOrder(BitConverter.ToInt16(new byte[] { 192, 12 }, 0)),
Datas = dnsPack.getNameByts(SeaFish.Settings.Custom.ServerName),
TTL = 100,
QueryClass = 1,
QueryType = QueryType.PTR,
}
};
Response(dnsPack.ToBytes(), client);
return;
}
}
}
}
else if (dnsPack.QueryRecords[0].QueryType == QueryType.A)
{
if (dnsPack.QueryRecords[0].QueryName == SeaFish.Settings.Custom.ServerName)
{
dnsPack.QR = 1; dnsPack.RA = 1; dnsPack.RD = 1;
dnsPack.ResouceRecords = new List <ResouceRecord> {
new ResouceRecord {
Point = IPAddress.HostToNetworkOrder(BitConverter.ToInt16(new byte[] { 192, 12 }, 0)),
Datas = new byte[] { 127, 0, 0, 1 },
TTL = 100,
QueryClass = 1,
QueryType = QueryType.A,
}
};
Response(dnsPack.ToBytes(), client);
return;
}
}
}
byte[] cache;
if (dataBase.ReadHost(dnsPack, out cache))
{
//如果存在host
Response(cache, client);
}
else if (dataBase.ReadCache(dnsPack, out cache))
{
//如果存在缓存数据
DnsPack dnsCache = new DnsPack(cache)
{
//这里需要修改识别标识
Sign = dnsPack.Sign,
};
Response(dnsCache.ToBytes(), client);
}
else
{
//无缓存则直接转发
RelayDNS(data.dnsPack, client);
}
}
/// <summary>
/// 转发DNS包
/// </summary>
/// <param name="buff">包内容字节数组</param>
/// <param name="read">包大小</param>
private void RelayDNS(byte[] buff, EndPoint client)
{
List <Task> taskList = new List <Task>();
bool isResponse = false;
DnsPack[] dnsPacks;
IPEndPoint[] server = new IPEndPoint[4];
server[0] = new IPEndPoint(SeaFish.Settings.Custom.Server1, 53); //公共DNS服务器IP
server[1] = new IPEndPoint(SeaFish.Settings.Custom.Server2, 53); //公共DNS服务器IP
server[2] = new IPEndPoint(SeaFish.Settings.Custom.Server3, 53); //公共DNS服务器IP
server[3] = new IPEndPoint(SeaFish.Settings.Custom.Server4, 53); //公共DNS服务器IP
int Relay = SeaFish.Settings.Custom.Relay;
switch (Relay)
{
case 0: //国内优先
//首先用境内DNS解析，如果解析到境外IP，则使用境外DNS再次解析
ResponsenNonDomain(buff, client);
break;
case 1: //国际优先
//首先用境外DNS解析，如果解析到境内IP，则使用境内DNS再次解析
ResponsenNonDomain(buff, client);
break;
case 2: //仅国内
RelayDns(false);
break;
case 3: //仅国际
RelayDns(true);
break;
default:
ResponsenNonDomain(buff, client);
return;
}
void RelayDns(bool inter)
{
//同时转发给两台服务器
int index = (inter) ? 2 : 0;
int Count = 0;
dnsPacks = new DnsPack[2];
for (int i = 0; i <= 1; i++)
{
TaskFactory taskfactory = new TaskFactory();
taskList.Add(taskfactory.StartNew(new Action <object>(t => {
int index_ = int.Parse(t.ToString());
dnsPacks[index_] = new DnsPack(SendUDP(server[index + index_], buff));
dnsPacks[index_].Tag = index_;
}), i).ContinueWith(m => {
Count++;
if (!isResponse)
{
foreach (DnsPack dns in dnsPacks)
{
if (!dns.Success)
{
continue;
}
if (dns.Rcode != 0)
{
continue;
}
if (dns.ResouceRecords.Count >= 1 ||
dns.GrantResouces.Count >= 1 ||
dns.AdditResouces.Count >= 1)
{
foreach (ResouceRecord dnsr in dns.ResouceRecords)
{
if (dnsr.QueryClass == 1 && dnsr.QueryType == QueryType.A)
{
Debug.WriteLine("数据来源：{0}\t中国地址：{1}\t解析值：{3}\t问题：{2}",
server[index + dns.Tag], IPinChina(dnsr.Datas), dns.QueryRecords[0].QueryName, new IPAddress(dnsr.Datas).ToString());
}
}
Response(dns, client);
isResponse = true;
return;
}
}
}
if (Count >= 2)
{
//所有服务器响应，但没有结果
ResponsenNonDomain(buff, client);
}
}));
}
}
bool IPinChina(byte[] IPadd)
{
try {
String IPAddres = new IPAddress(IPadd).ToString();
string nettexts = SeaFish.Extend.ReadFile(basePaht).Replace("\r\n", "\n");
string[] networks = nettexts.Split((char)10);
foreach (string net in networks)
{
if (SeaFish.Extend.IP_IN_Nework(IPAddres, net))
{
return(true);
}
}
} catch {}
return(false);
}
}
