java实现一个socks5代理 <一>了解nio Selector的基本用法

淡淡的烟草味﹌ 2022-06-04 06:36 1057阅读 0赞

上面浏览器可以放心的将数据交给代理了，接下来做的是怎样处理这些数据，以及面对浏览器突然过来的很多连接如何处理他们，这就要用到javax.nio包下的东西了，下面做简单介绍，不会nio可以先去学习下nio selector的基本用法，再回来接着看，下面先讲思路再上代码

1.创建ServiceSocketChannel,监听在5661端口。

2.像selector注册accept事件

3.堵塞式的从selector选择，选择后就开始执行

4.允许所有的连接，对获取到的连接都发送 5 0 表示接受无密码的连接

5.接受到ip port 的信息后，ip port 解析出来，异步连接到此ip port 并注册 connection事件

6。当连接事件触发后，完成连接，像浏览器返回 连接成功的标识。

7.像selector注册两个监听，分别监听client 和 外网 的socketchannel连接 read事件

8.当监听到其中一方的数据就读取并将数据写入另一方的channel中。

9.当读到流的末尾，管理连接，注销掉channel 等。

10.socks4的握手方式和socks5不同其他都相同，所以可以共用大部分代码

package com.proxydemo;
    import java.io.IOException;
    public class Main {
    	//程序启动入口
    	public static void main(String[] args) throws IOException {
    		Reactor reactor=new Reactor();
    		reactor.run();
    	}
    }

package com.proxydemo;
    /*

容器类，selector的创建 以及做选择 并且执行的类

*/
    import java.io.IOException;
    import java.net.InetSocketAddress;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.ServerSocketChannel;
    import java.util.Iterator;
    import java.util.Set;
    
    //容器类
    public class Reactor implements Runnable {
    	private Selector selector;	//容器
    	private ServerSocketChannel ssc;	//服务端socketchannel
    	
    	public Reactor() throws IOException{
    	//初始化容器和服务器
    		selector=Selector.open();
    		ssc=ServerSocketChannel.open();
    	//绑定事件 和 端口 设置异步
    		ssc.bind(new InetSocketAddress(5661));
    		ssc.configureBlocking(false);
    		SelectionKey key = ssc.register(selector, SelectionKey.OP_ACCEPT);
    		//创建accept事件,以及创建处理的线程
    		key.attach(new AcceptAcceptor(selector,ssc));

}
    	
    	public void run() {
    		while(true){
    			try {
    				int size = selector.select();
    				if(size==0){
    					continue;
    				}
    			} catch (IOException e) {
    				e.printStackTrace();
    			}
    
    			Set<SelectionKey> keys = selector.selectedKeys();
    			Iterator<SelectionKey> iterator = keys.iterator();
    			while(iterator.hasNext()){
    				SelectionKey next = iterator.next();
    				consume(next);
    				iterator.remove();
    			}
    		}
    		
    	}
    	
    	private void consume(SelectionKey key){
    		Runnable r = (Runnable) key.attachment();
    		r.run();
    	}
    	
    
    }

package com.proxydemo;
    
    import java.io.IOException;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.ServerSocketChannel;
    import java.nio.channels.SocketChannel;
    
    
    //负责接受连接的类，接受完立即注册   读操作 读操作出发 Handler551
    public class AcceptAcceptor implements Runnable {
    	private Selector selector;
    	private ServerSocketChannel ssc;
    	
    	public AcceptAcceptor(Selector selector,ServerSocketChannel ssc){
    		this.selector=selector;
    		this.ssc=ssc;
    	}
    	
    	
    	public void run() {
    		try {
    			SocketChannel socket = ssc.accept();
    			socket.configureBlocking(false);
    			SelectionKey keyclient = socket.register(selector, SelectionKey.OP_READ);
    			keyclient.attach(new Handler551(keyclient));		
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    		
    		
    		
    		
    	}
    
    }

package com.proxydemo;
    
    import java.io.IOException;
    import java.net.InetAddress;
    import java.nio.ByteBuffer;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.SocketChannel;
    import java.util.Arrays;
    
    
    /*出发了读操作触发此事件 目的读取 5 1 0 /或者4 1 0 
     * 出发写操作的事件，目的写入 5 0
     * 根据事件的不同做出不同行为

根据是socks4 /socks5做不同处理
     * */
    public class Handler551 implements Runnable {
    	
    	private Selector selector;
    	private SocketChannel sc;
    	private SelectionKey keyclient;
    	private ByteBuffer bytebuffer=ByteBuffer.allocate(10);
    	static byte bb510[]={5,0};
    	static byte bb410[]={0,90,0,0,0,0,0,0};
    	 //返回愿意连接
    	public Handler551(SelectionKey keyclient){
    			this.selector=keyclient.selector();
    			this.keyclient=keyclient;
    			sc=(SocketChannel) keyclient.channel();
    	}
    	
    	
    	public void run() {
    		bytebuffer.clear();
    			try {
    				int read = sc.read(bytebuffer);
    				if(read==-1){
    					keyclient.cancel();
    					return;
    				}
    				System.out.println("得到的结果"+Arrays.toString(bytebuffer.array()));
    				int b = bytebuffer.get(0);
    				if(b==5){ //协议5
    					sc.write(ByteBuffer.wrap(bb510));
    					keyclient.attach(new Handler501002( keyclient));
    				}else if(b==4){	//协议4
    					int portflag=bytebuffer.get(2);
    					int port=bytebuffer.get(3);
    					if(port>0){
    						port=256*portflag+port;
    					}else{
    						port=256*portflag+(256+port);
    					}
    					StringBuilder sb=new StringBuilder();
    					int A=bytebuffer.get(4);
    					int B=bytebuffer.get(5);
    					int C=bytebuffer.get(6);
    					int D=bytebuffer.get(7);
    					System.out.println("原来的"+A+"."+B+"."+C+"."+D);
    					if(A<0) A=256+A;
    					if(B<0) B=256+B;
    					if(C<0) C=256+C;
    					if(D<0) D=256+D;
    					sb.append(A);sb.append(".");sb.append(B);sb.append(".");
    					sb.append(C);sb.append(".");sb.append(D);
    					
    					String host=sb.toString();
    					sc.write(ByteBuffer.wrap(bb410));
    					keyclient.attach(new Sockts4Handler( keyclient,host,port));
    					
    				}
    
    			} catch (IOException e) {
    				keyclient.cancel();
    				selector.wakeup();
    				e.printStackTrace();
    			}
    		
    	}
    }

package com.proxydemo;
    
    import java.io.IOException;
    import java.net.InetSocketAddress;
    import java.nio.ByteBuffer;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.SocketChannel;
    
    /*
     * 第一步初步握手完成后 第二步 进行验证握手
     如果是socks5 则执行这一步 进行接受ip和端口信息 * */
    
    public class Handler501002 implements Runnable {
    	private Selector selector;
    	private SocketChannel sc;
    	private SelectionKey keyclient;
    	static byte bb501002[]={5,0,0,1,0,0,0,0,1,1};
    	ByteBuffer bytebuffer=ByteBuffer.allocate(100);
    	public Handler501002(SelectionKey keyclient){
    			this.selector=keyclient.selector();
    			this.keyclient=keyclient;
    			this.sc=(SocketChannel) keyclient.channel();
    	}
    	
    	/*	1.读取数据
    	 * 	2.解析数据，建立连接，绑定下一个handler
    	 * 
    	 * */
    	public void run() {
    				int read=-1;
    				try {
    					read = sc.read(bytebuffer);
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    				if(read==-1){
    					keyclient.cancel();
    					return;
    				}
    				
    				//sc.write(ok50001);
    				//2.解析数据
    				String host=getHost(bytebuffer.asReadOnlyBuffer(), read);
    				int port=getPort(bytebuffer.asReadOnlyBuffer(), read);
    				try{
    				//4.不处理host为空的数据
    				if(host==null||"".equals(host)){
    					for(int i=0;i<read;i++){						//***********************
    						System.out.print(bytebuffer.get(i));
    						System.out.println("host null");
    					}
    					sc.close();
    					keyclient.cancel();
    					selector.wakeup();
    					return;
    				}
    				//3.创建channel
    				SocketChannel scClient=SocketChannel.open();
    				//5 不处理查找不到ip地址的域名
    				InetSocketAddress isa=new InetSocketAddress(host, port);
    				if(isa.isUnresolved() || isa.getAddress().equals("") ||isa.getAddress().equals("127.0.0.1")){
    					sc.close();
    					keyclient.cancel();
    					return;
    				}
    				//5.设置异步
    				scClient.configureBlocking(false);
    				//6.异步连接
    				scClient.connect(isa);
    				//7.注册
    				SelectionKey register = scClient.register(selector, SelectionKey.OP_CONNECT);
    				//7 还没有连接上时 暂时不监测client、的是否有东西可读
    				keyclient.interestOps(keyclient.interestOps() &~SelectionKey.OP_READ );
    				//8添加连接事件
    				/* 分别是与优酷之间的连接 || 与client之间的连接  */
    				register.attach(new LinkFinish( register,keyclient)); //传进去代理和优酷之间的连接
    			
    				System.out.println(host+":"+port);
    				}catch(IOException e){
    					e.printStackTrace();
    				}
    	}
    	
    	
    	//解析地址
    			public String getHost(ByteBuffer a,int len){
    				if(len<8){
    					return null;
    				}
    				StringBuffer sb=new StringBuffer();
    				if(a.get(3)==3){
    					//说明是网址地址
    					int size=a.get(4); //网址长度
    					for(int i=5;i<(5+size);i++){
    						sb.append((char)a.get(i));
    					}
    					
    				}else if(a.get(3)==1){
    					//说明是ip地址
    					for(int i=4;i<=7;i++){
    						int A=a.get(i);
    						if(A<0) A=256+A;
    						sb.append(A);
    						sb.append(".");
    					}
    					sb.deleteCharAt(sb.length()-1);
    				}
    				return sb.toString();
    			}
    			
    			//解析端口
    			public int getPort(ByteBuffer a,int len){
    				if(len<4){
    					return 0;
    				}
    				int port = a.get(len-1);
    				int thod=a.get(len-2);
    				if(port>0){
    					return 256*thod+port;
    				}else{
    					return 256*thod +(256+port);
    				}
    			}
    }

package com.proxydemo;
    
    import java.io.IOException;
    import java.nio.ByteBuffer;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.SocketChannel;
    import java.util.concurrent.TimeoutException;
    
    /*
     * 异步连接如果触发，则完成连接，注册读取事件
     上一步获取了真正的ip和port并进行异步连接，这一步完成真正的连接* */
    
    
    public class LinkFinish implements Runnable {
    	static byte bb501002[]={5,0,0,1,0,0,0,0,1,1};
    		private Selector selector;
    		private SocketChannel sc; //代理和实际网站的连接
    		private SocketChannel cd; //client和代理之间
    		private SelectionKey key551,keyWeb;
    		
    		public LinkFinish(SelectionKey keyWeb,SelectionKey key551){
    				this.selector=key551.selector();
    				this.key551=key551;
    				this.keyWeb=keyWeb;
    				sc=(SocketChannel) keyWeb.channel();
    				cd=(SocketChannel) key551.channel();
    				
    		}
    	public void run() {
    		//1.完成连接
    			boolean finishConnect =false;
    			try {
    				finishConnect = sc.finishConnect();
    				//1  向客户端通知他连接成功了，可以发送数据了
    				ByteBuffer ok50001 = ByteBuffer.wrap(bb501002);//返回愿意连接
    					cd.write(ok50001);
    					
    			if(finishConnect){
    			//2.转换成read
    				//keyFor.interestOps(SelectionKey.OP_READ &~SelectionKey.OP_CONNECT);
    				keyWeb.interestOps(keyWeb.interestOps() & 0 |SelectionKey.OP_READ);
    				key551.interestOps(SelectionKey.OP_READ );
    			//3.切换handler
    				keyWeb.attach(new ReadHandler(keyWeb,key551));	//设置Handler   代理to优酷      电脑to代理
    				key551.attach(new ReadHandler2( keyWeb,key551));		//代理to优酷      电脑to代理
    				System.out.println("实际连接");
    		//	selector.wakeup();
    			}
    	
    			
    			} catch (IOException e1) {
    				try {
    					sc.close();
    					cd.close();
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    				keyWeb.cancel();
    				key551.cancel();
    				System.out.println("超时一个"+sc.socket().getInetAddress());
    			//selector.wakeup();
    				return;
    			}
    		
    		
    		
    	}
    
    }

package com.proxydemo;
    
    import java.io.IOException;
    import java.nio.ByteBuffer;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.SocketChannel;
    import java.util.Arrays;
    
    /*
     * 代理将数据打向浏览器
     * */
    public class ReadHandler implements Runnable {
    
    	private Selector selector;
    	private SocketChannel sc; //代理和优酷网站之间的通道
    	private SocketChannel cd;//浏览器和代理之间的通道
    	private SelectionKey key551,keyWeb;
    	
    	
    	ByteBuffer buffer=ByteBuffer.allocate(6144);
    	public ReadHandler(SelectionKey keyWeb,SelectionKey key551){
    			this.selector=key551.selector();
    			this.keyWeb=keyWeb;
    			this.key551=key551;
    			sc=(SocketChannel) keyWeb.channel();
    			cd=(SocketChannel) key551.channel();
    	}
    	/*负责交换数据，都的话放进缓冲区，写的话，从缓冲区中国写
    	 * */
    	
    	public void run() {
    	//	ByteBuffer buffer=ByteBuffer.allocate(4096);
    	 //浏览器打向代理
    			//1.清空缓冲区
    			buffer.clear();
    			//2.读取数据
    		
    				int read=-1;
    				try {
    					read = sc.read(buffer);
    				} catch (IOException e1) {
    					/*异常则证明连接已经断开了，直接断开就可以*/
    					e1.printStackTrace();
    				}
    				//检查是否是-1 是的话说明没有数据读 或者已经关闭了
    				if(read==-1){
    					//没关闭就将他关闭
    					if(sc.isOpen()){
    						try {
    							sc.close();
    						} catch (IOException e) {
    							e.printStackTrace();
    						}
    					}
    					keyWeb.cancel();
    					return;
    					//selector.wakeup();
    				}
    				
    				int write=-1;
    					if(read>0){
    					buffer.flip();
    					if(cd.isOpen()){
    					try {
    						 write = cd.write(buffer);
    					} catch (IOException e) {
    						e.printStackTrace();
    						}
    					}
    					
    					}
    				if(write==-1){
    					if(cd.isOpen()){
    						try {
    							cd.close();
    						} catch (IOException e) {
    							e.printStackTrace();
    						}
    						key551.cancel();
    						
    					}
    					
    				}
    				
    					buffer.clear();
    				
    					if(read==0){
    						//	keyFor2.interestOps(SelectionKey.OP_WRITE);
    						//selector.wakeup();
    					}
    					
    				System.out.println(read+"接收");	
    			
    		
    		
    		
    		
    	}
    
    }

package com.proxydemo;
    
    import java.io.IOException;
    import java.nio.ByteBuffer;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.SocketChannel;
    
    //浏览器将数据打向代理
    //
    public class ReadHandler2 implements Runnable {
    
    	private Selector selector;
    	private SocketChannel sc; //代理和优酷网站之间的通道
    	private SocketChannel cd;//浏览器和代理之间的通道
    	private SelectionKey key551,keyWeb;
    	ByteBuffer buffer=ByteBuffer.allocate(6144);
    	public ReadHandler2(SelectionKey keyWeb,SelectionKey key551){
    			this.selector=key551.selector();
    			this.keyWeb=keyWeb;
    			this.key551=key551;
    			this.sc=(SocketChannel) keyWeb.channel();
    			this.cd=(SocketChannel) key551.channel();
    	}
    	/*负责交换数据，都的话放进缓冲区，写的话，从缓冲区中国写
    	 * */
    	public void run() {
    	//	ByteBuffer buffer=ByteBuffer.allocate(10240);
    			//1.清空缓冲区
    			buffer.clear();
    			//2.读取数据
    				int read=-1;
    				if(cd.isOpen()){
    				try {
    					read = cd.read(buffer);
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    				}
    				
    				if(read==-1){
    					if(cd.isOpen()){
    					try {
    						cd.close();
    					} catch (IOException e) {
    						e.printStackTrace();
    					}
    					}
    					key551.cancel();
    					return;
    				}
    				
    				int write=-1;
    					if(read>0){
    						buffer.flip();
    						if(cd.isOpen()){
    						try {
    							write = sc.write(buffer);
    						} catch (IOException e) {
    							e.printStackTrace();
    						}
    						}
    					}
    					
    					if(write==-1){
    						if(cd.isOpen()){
    							try {
    								cd.close();
    							} catch (IOException e) {
    								e.printStackTrace();
    							}
    						}
    						keyWeb.cancel();
    					}
    					
    					buffer.clear();
    				
    					
    					if(read==0){
    						//keyFor.interestOps(SelectionKey.OP_WRITE);
    						//selector.wakeup();
    					}
    					System.out.println("发送"+read);
    			
    		
    		
    	}
    
    }

package com.proxydemo;
    
    import java.io.IOException;
    import java.net.InetSocketAddress;
    import java.nio.ByteBuffer;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.SocketChannel;
    //如果是sockets4 则执行这个
    public class Sockts4Handler implements Runnable {
    
    	private Selector selector;
    	private SocketChannel sc;
    	private SelectionKey keyclient;
    	String host;
    	int port;
    	public Sockts4Handler(SelectionKey keyclient,String host,int port){
    			this.selector=keyclient.selector();
    			this.keyclient=keyclient;
    			this.sc=(SocketChannel) keyclient.channel();
    			this.host=host;
    			this.port=port;
    	}
    	
    	/*	1.读取数据
    	 * 	2.解析数据，建立连接，绑定下一个handler
    	 * 
    	 * */
    	public void run() {	
    				try{
    				//4.不处理host为空的数据
    				if(host==null||"".equals(host)){
    					sc.close();
    					keyclient.cancel();
    					selector.wakeup();
    					return;
    				}
    				//3.创建channel
    				SocketChannel scClient=SocketChannel.open();
    				//5 不处理查找不到ip地址的域名
    				InetSocketAddress isa=new InetSocketAddress(host, port);
    				if(isa.isUnresolved() || isa.getAddress().equals("") ||isa.getAddress().equals("127.0.0.1")){
    					sc.close();
    					keyclient.cancel();
    					return;
    				}
    				//5.设置异步
    				scClient.configureBlocking(false);
    				//6.异步连接
    				scClient.connect(isa);
    				//7.注册
    				SelectionKey register = scClient.register(selector, SelectionKey.OP_CONNECT);
    				//7 还没有连接上时 暂时不监测client、的是否有东西可读
    				keyclient.interestOps(keyclient.interestOps() &~SelectionKey.OP_READ );
    				//8添加连接事件
    				/* 分别是与优酷之间的连接 || 与client之间的连接  */
    				register.attach(new Sockets4LinkFinish( register,keyclient)); //传进去代理和优酷之间的连接
    				System.out.println(host+":"+port);
    				}catch(IOException e){
    					e.printStackTrace();
    				}
    	}
    	
    	
    
    	
    }

package com.proxydemo;
    
    import java.io.IOException;
    import java.nio.ByteBuffer;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.SocketChannel;
    import java.util.concurrent.TimeoutException;
    
    /*
     * 异步连接如果触发，则完成连接，注册读取事件
     sockets4 执行这个* */
    
    
    public class Sockets4LinkFinish implements Runnable {
    	static byte bb501002[]={5,0,0,1,0,0,0,0,1,1};
    	static byte bb401002[]={0,90,0,0,0,0,0,0};
    		private Selector selector;
    		private SocketChannel sc; //代理和实际网站的连接
    		private SocketChannel cd; //client和代理之间
    		private SelectionKey key551,keyWeb;
    		
    		public Sockets4LinkFinish(SelectionKey keyWeb,SelectionKey key551){
    				this.selector=key551.selector();
    				this.key551=key551;
    				this.keyWeb=keyWeb;
    				sc=(SocketChannel) keyWeb.channel();
    				cd=(SocketChannel) key551.channel();
    				
    		}
    	public void run() {
    		//1.完成连接
    			boolean finishConnect =false;
    			try {
    				finishConnect = sc.finishConnect();
    				//1  向客户端通知他连接成功了，可以发送数据了
    				ByteBuffer ok50001 = ByteBuffer.wrap(bb401002);//返回愿意连接
    					//cd.write(ok50001);
    					
    			if(finishConnect){
    			//2.转换成read
    				//keyFor.interestOps(SelectionKey.OP_READ &~SelectionKey.OP_CONNECT);
    				keyWeb.interestOps(keyWeb.interestOps() & 0 |SelectionKey.OP_READ);
    				key551.interestOps(SelectionKey.OP_READ );
    			//3.切换handler
    				keyWeb.attach(new ReadHandler(keyWeb,key551));	//设置Handler   代理to优酷      电脑to代理
    				key551.attach(new ReadHandler2( keyWeb,key551));		//代理to优酷      电脑to代理
    				System.out.println("实际连接");
    		//	selector.wakeup();
    			}
    	
    			
    			} catch (IOException e1) {
    				try {
    					sc.close();
    					cd.close();
    				} catch (IOException e) {
    					e.printStackTrace();
    				}
    				keyWeb.cancel();
    				key551.cancel();
    				System.out.println("超时一个"+sc.socket().getInetAddress());
    			//selector.wakeup();
    				return;
    			}
    		
    		
    		
    	}
    
    }

这个demo主要是练习下nio的使用，兼容socks4 后，可以将internate选项中设置套接字，那个直接就是socks4的代理，这样能看到很多数据包在代理中流动，本地使用对浏览器打开网页的速度影响非常小，几乎看不出来

这里的源码下载可以导入eclipse 直接执行看结果了  [源码][Link 1]地址

[Link 1]: https://github.com/switchYello/javaSocket5Proxy