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前言
DNS 协定作为着互联网客户端 - 服务器通信模式得第一关,在当下每天都有成千上亿上网记录产生得当今社会,其重要性天然不可言喻。在国内比拟有名得 DNS 服务器有电信得 114.114.114.114、阿里云得 223.5.5.5,DNSPod 得 119.29.29.29,配置一个好的 DNS 服务器能够缩短申请响应工夫、升高 DNS 劫持概率,晋升上网体验。
下面这些都是互联网专用 DNS 服务器,本文博主教大家应用 Java Netty
自建 DNS 代理服务器,目前网上对于应用 Netty 自建 DNS 服务器得教程参差不齐,大多没有代理步骤,达不到博主想要得代理成果,因此创立此文。
一、自建 DNS 代理服务器有哪些劣势
- 域名管制:对于特定域名能够自在管制拜访权限(屏蔽对特定网站拜访)
- 域名记录:记录局域网内各个主机得域名拜访(记录员工上网记录)
- 配置内网域名:通过自建 DNS 服务器能够配置内网域名,节约老本
- DNS 负载平衡:通过自建 DNS 服务器能够轻松实现对于拜访域名得负载平衡配置
- …
二、自建 DNS 代理服务器代码
- 增加域名黑名单文件,
resources
文件夹下增加black_list.txt
文件
google.com.
facebook.com.
初始化 BLACK_LIST_DOMAIN
private static final List<String> BLACK_LIST_DOMAIN = new ArrayList<>();
static {
String s;
try (InputStream is = DnsServer.class.getClassLoader().getResourceAsStream("black_list.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(is))) {while (StrUtil.isNotBlank(s = br.readLine())) {BLACK_LIST_DOMAIN.add(s);
}
} catch (Exception e) {log.error(e.getMessage(), e);
}
}
- 应用
UDP
协定绑定本机 53 端口,并初始化ProxyUdp
DNS 申请代理对象
@Slf4j
public final class DnsServer {private static final List<String> BLACK_LIST_DOMAIN = new ArrayList<>();
static {...}
public static void main(String[] args) throws Exception {ProxyUdp proxyUdp = new ProxyUdp();
proxyUdp.init();
final int[] num = {0};
final NioEventLoopGroup group = new NioEventLoopGroup();
Bootstrap bootstrap = new Bootstrap();
bootstrap.group(group).channel(NioDatagramChannel.class)
.handler(new ChannelInitializer<NioDatagramChannel>() {
@Override
protected void initChannel(NioDatagramChannel nioDatagramChannel) {nioDatagramChannel.pipeline().addLast(...);
}
}).option(ChannelOption.SO_BROADCAST, true);
int port = 53;
ChannelFuture future = bootstrap.bind(port).addListener(future1 -> {log.info("server listening port:{}", port);
});
future.channel().closeFuture().addListener(future1 -> {if (future.isSuccess()) {log.info(future.channel().toString());
}
});
}
}
- 给
nioDatagramChannel.pipeline()
增加ChannelHandler
nioDatagramChannel.pipeline().addLast(new DatagramDnsQueryDecoder());
nioDatagramChannel.pipeline().addLast(new SimpleChannelInboundHandler<DatagramDnsQuery>() {
@Override
protected void channelRead0(ChannelHandlerContext ctx, DatagramDnsQuery msg) {
try {DefaultDnsQuestion dnsQuestion = msg.recordAt(DnsSection.QUESTION);
String name = dnsQuestion.name();
log.info(name + ++num[0]);
Channel channel = ctx.channel();
int id = msg.id();
channel.attr(AttributeKey.<DatagramDnsQuery>valueOf(String.valueOf(id))).set(msg);
if (BLACK_LIST_DOMAIN.contains(name)) {DnsQuestion question = msg.recordAt(DnsSection.QUESTION);
DatagramDnsResponse dnsResponse = getDatagramDnsResponse(msg, id, question);
channel.writeAndFlush(dnsResponse);
return;
}
proxyUdp.send(name, msg.id(), channel);
} catch (Exception e) {log.error(e.getMessage(), e);
}
}
private DatagramDnsResponse getDatagramDnsResponse(DatagramDnsQuery msg, int id, DnsQuestion question) {DatagramDnsResponse dnsResponse = new DatagramDnsResponse(msg.recipient(), msg.sender(), id);
dnsResponse.addRecord(DnsSection.QUESTION, question);
DefaultDnsRawRecord queryAnswer = new DefaultDnsRawRecord(question.name(),
DnsRecordType.A, 600, Unpooled.wrappedBuffer(new byte[]{(byte) 192, (byte) 168, 1, 1}));
dnsResponse.addRecord(DnsSection.ANSWER, queryAnswer);
return dnsResponse;
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable e) {log.error(e.getMessage(), e);
}
});
nioDatagramChannel.pipeline().addLast(new DatagramDnsResponseEncoder());
在 new SimpleChannelInboundHandler<DatagramDnsQuery>()
中 解析客户端 DNS 查问报文, 获取拜访域名信息,如果拜访域名在黑名单中,则通过 getDatagramDnsResponse()
间接返回 192.168.1.1
的 DNS 响应报文,反之则通过 proxyUdp
对象转发 DNS 查问。
ProxyUdp
作为 DNS 查问代理类会通过send(String domain, int id, Channel serverChannel)
办法传入 DnsServer 类收到的拜访域名、DNS 事务 ID、serverChannel。随后包装拜访域名申请 DNS 服务器114.114.114.114
,最初通过new SimpleChannelInboundHandler<DatagramDnsResponse>()
将收到的 DNS 响应报文通过上一步传入得serverChannel
输入到客户端。
@Slf4j
class ProxyUdp {
private Channel serverChannel;
private Channel proxyChannel;
public void init() throws InterruptedException {EventLoopGroup proxyGroup = new NioEventLoopGroup();
Bootstrap b = new Bootstrap();
b.group(proxyGroup)
.channel(NioDatagramChannel.class)
.handler(new ChannelInitializer<DatagramChannel>() {
@Override
protected void initChannel(DatagramChannel ch) {ChannelPipeline p = ch.pipeline();
p.addLast(new DatagramDnsQueryEncoder())
.addLast(new DatagramDnsResponseDecoder())
.addLast(new SimpleChannelInboundHandler<DatagramDnsResponse>() {
@Override
public void channelActive(ChannelHandlerContext ctx) {log.info(ctx.channel().toString());
}
@Override
protected void channelRead0(ChannelHandlerContext ctx, DatagramDnsResponse msg) {DatagramDnsQuery dnsQuery = localChannel.attr(AttributeKey.<DatagramDnsQuery>valueOf(String.valueOf(msg.id()))).get();
DnsQuestion question = msg.recordAt(DnsSection.QUESTION);
DatagramDnsResponse dnsResponse = new DatagramDnsResponse(dnsQuery.recipient(), dnsQuery.sender(), msg.id());
dnsResponse.addRecord(DnsSection.QUESTION, question);
for (int i = 0, count = msg.count(DnsSection.ANSWER); i < count; i++) {DnsRecord record = msg.recordAt(DnsSection.ANSWER, i);
if (record.type() == DnsRecordType.A) {
// just print the IP after query
DnsRawRecord raw = (DnsRawRecord) record;
DefaultDnsRawRecord queryAnswer = new DefaultDnsRawRecord(question.name(),
DnsRecordType.A, 600, Unpooled.wrappedBuffer(ByteBufUtil.getBytes(raw.content())));
dnsResponse.addRecord(DnsSection.ANSWER, queryAnswer);
}
}
serverChannel.writeAndFlush(dnsResponse);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable e) {log.error(e.getMessage(), e);
}
});
}
});
proxyChannel = b.bind(0).sync().addListener(future1 -> {log.info("绑定胜利");
}).channel();}
public void send(String domain, int id, Channel serverChannel) {
this.serverChannel = serverChannel;
DnsQuery query = new DatagramDnsQuery(null, new InetSocketAddress("114.114.114.114", 53), id).setRecord(
DnsSection.QUESTION,
new DefaultDnsQuestion(domain, DnsRecordType.A));
this.proxyChannel.writeAndFlush(query);
}
}
- 自建 DNS 服务器全副代码
@Slf4j
public final class DnsServer {private static final List<String> BLACK_LIST_DOMAIN = new ArrayList<>();
static {
String s;
try (InputStream is = DnsServer.class.getClassLoader().getResourceAsStream("black_list.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(is))) {while (StrUtil.isNotBlank(s = br.readLine())) {BLACK_LIST_DOMAIN.add(s);
}
} catch (Exception e) {log.error(e.getMessage(), e);
}
}
public static void main(String[] args) throws Exception {ProxyUdp proxyUdp = new ProxyUdp();
proxyUdp.init();
final int[] num = {0};
final NioEventLoopGroup group = new NioEventLoopGroup();
Bootstrap bootstrap = new Bootstrap();
bootstrap.group(group).channel(NioDatagramChannel.class)
.handler(new ChannelInitializer<NioDatagramChannel>() {
@Override
protected void initChannel(NioDatagramChannel nioDatagramChannel) {nioDatagramChannel.pipeline().addLast(new DatagramDnsQueryDecoder());
nioDatagramChannel.pipeline().addLast(new SimpleChannelInboundHandler<DatagramDnsQuery>() {
@Override
protected void channelRead0(ChannelHandlerContext ctx, DatagramDnsQuery msg) {
try {DefaultDnsQuestion dnsQuestion = msg.recordAt(DnsSection.QUESTION);
String name = dnsQuestion.name();
log.info(name + ++num[0]);
Channel channel = ctx.channel();
int id = msg.id();
channel.attr(AttributeKey.<DatagramDnsQuery>valueOf(String.valueOf(id))).set(msg);
if (BLACK_LIST_DOMAIN.contains(name)) {DnsQuestion question = msg.recordAt(DnsSection.QUESTION);
DatagramDnsResponse dnsResponse = getDatagramDnsResponse(msg, id, question);
channel.writeAndFlush(dnsResponse);
return;
}
proxyUdp.send(name, msg.id(), channel);
} catch (Exception e) {log.error(e.getMessage(), e);
}
}
private DatagramDnsResponse getDatagramDnsResponse(DatagramDnsQuery msg, int id, DnsQuestion question) {DatagramDnsResponse dnsResponse = new DatagramDnsResponse(msg.recipient(), msg.sender(), id);
dnsResponse.addRecord(DnsSection.QUESTION, question);
// just print the IP after query
DefaultDnsRawRecord queryAnswer = new DefaultDnsRawRecord(question.name(),
DnsRecordType.A, 600, Unpooled.wrappedBuffer(new byte[]{(byte) 192, (byte) 168, 1, 1}));
dnsResponse.addRecord(DnsSection.ANSWER, queryAnswer);
return dnsResponse;
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable e) {log.error(e.getMessage(), e);
}
});
nioDatagramChannel.pipeline().addLast(new DatagramDnsResponseEncoder());
}
}).option(ChannelOption.SO_BROADCAST, true);
int port = 553;
ChannelFuture future = bootstrap.bind(port).addListener(future1 -> {log.info("server listening port:{}", port);
});
future.channel().closeFuture().addListener(future1 -> {if (future.isSuccess()) {log.info(future.channel().toString());
}
});
}
}
@Slf4j
class ProxyUdp {
private Channel localChannel;
private Channel proxyChannel;
public void init() throws InterruptedException {EventLoopGroup proxyGroup = new NioEventLoopGroup();
Bootstrap b = new Bootstrap();
b.group(proxyGroup)
.channel(NioDatagramChannel.class)
.handler(new ChannelInitializer<DatagramChannel>() {
@Override
protected void initChannel(DatagramChannel ch) {ChannelPipeline p = ch.pipeline();
p.addLast(new DatagramDnsQueryEncoder())
.addLast(new DatagramDnsResponseDecoder())
.addLast(new SimpleChannelInboundHandler<DatagramDnsResponse>() {
@Override
public void channelActive(ChannelHandlerContext ctx) {log.info(ctx.channel().toString());
}
@Override
protected void channelRead0(ChannelHandlerContext ctx, DatagramDnsResponse msg) {DatagramDnsQuery dnsQuery = localChannel.attr(AttributeKey.<DatagramDnsQuery>valueOf(String.valueOf(msg.id()))).get();
DnsQuestion question = msg.recordAt(DnsSection.QUESTION);
DatagramDnsResponse dnsResponse = new DatagramDnsResponse(dnsQuery.recipient(), dnsQuery.sender(), msg.id());
dnsResponse.addRecord(DnsSection.QUESTION, question);
for (int i = 0, count = msg.count(DnsSection.ANSWER); i < count; i++) {DnsRecord record = msg.recordAt(DnsSection.ANSWER, i);
if (record.type() == DnsRecordType.A) {
// just print the IP after query
DnsRawRecord raw = (DnsRawRecord) record;
DefaultDnsRawRecord queryAnswer = new DefaultDnsRawRecord(question.name(),
DnsRecordType.A, 600, Unpooled.wrappedBuffer(ByteBufUtil.getBytes(raw.content())));
dnsResponse.addRecord(DnsSection.ANSWER, queryAnswer);
}
}
localChannel.writeAndFlush(dnsResponse);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable e) {log.error(e.getMessage(), e);
}
});
}
});
proxyChannel = b.bind(0).sync().addListener(future1 -> {log.info("绑定胜利");
}).channel();}
public void send(String domain, int id, Channel localChannel) {
this.localChannel = localChannel;
DnsQuery query = new DatagramDnsQuery(null, new InetSocketAddress("114.114.114.114", 53), id).setRecord(
DnsSection.QUESTION,
new DefaultDnsQuestion(domain, DnsRecordType.A));
this.proxyChannel.writeAndFlush(query);
}
}
三、本地测试
- 批改本机 DNS 设置 (win11),批改首选、备选 DNS 地址为 127.0.0.1
- 关上命令行工具,执行 DNS 缓存革除命令
ipconfig/flushdns
自此就能够关上浏览器拜访罕用网站,看是否能失常拜访,来验证自建的 DNS 服务器成果了
正文完