Socket代理转发小记

港控/mmm° 2022-06-17 12:07 206阅读 0赞

![0_1324008339dO9h.gif][]

本地转发代码forward.py

#!/usr/bin/env python
    
    import os
    import socket
    import select
    import SocketServer
    import sys
    
    import paramiko
    def verbose(s):
            print s
    class ForwardServer (SocketServer.ThreadingTCPServer):
        daemon_threads = True
        allow_reuse_address = True
    class Handler (SocketServer.BaseRequestHandler):
        def handle(self):
            try:
                chan = self.ssh_transport.open_channel('direct-tcpip',
                                                       (self.chain_host, self.chain_port),
                                                       self.request.getpeername())
            except Exception, e:
                verbose('Incoming request to %s:%d failed: %s' % (self.chain_host,
                                                                  self.chain_port,
                                                                  repr(e)))
                return
            if chan is None:
                verbose('Incoming request to %s:%d was rejected by the SSH server.' %
                        (self.chain_host, self.chain_port))
                return
            verbose('Connected!  Tunnel open %r -> %r -> %r' % (self.request.getpeername(),
                                                                chan.getpeername(), (self.chain_host, self.chain_port)))
            try:
                while True:
                    r, w, x = select.select([self.request, chan], [], [])
                    if self.request in r:
                        data = self.request.recv(1024)
                        if len(data) == 0:
                            break
                        chan.send(data)
                    if chan in r:
                        data = chan.recv(1024)
                        if len(data) == 0:
                            break
                        self.request.send(data)
            except Exception as e:
                  verbose('Forward request to %s:%d was failed.' %
                        (self.chain_host, self.chain_port))
            verbose('Tunnel closed from %r' % (self.request.getpeername(),))
            chan.close()
            self.request.close()
    
    forwardServer=None;
    def forward_tunnel(local_port, remote_host, remote_port, transport):
        class SubHander (Handler):
            chain_host = remote_host
            chain_port = remote_port
            ssh_transport = transport
        global forwardServer
        forwardServer=ForwardServer(('', local_port), SubHander);
        forwardServer.serve_forever();
    def stopForward():
        if forwardServer:
            forwardServer.shutdown();
    
    def forward(local_port,ssh_host,ssh_port,username,password,remote_host,remote_port):
        client = paramiko.SSHClient()
        client.load_system_host_keys()
        client.set_missing_host_key_policy(paramiko.WarningPolicy())
        try:
            client.connect(ssh_host, ssh_port, username,password)
        except Exception, e:
            print '*** Failed to connect to %s:%d: %r' % (ssh_host, ssh_port, e)
            sys.exit(1)
        verbose('Now forwarding port %d to %s:%d ...' % (local_port, remote_host, remote_port))
        try:
            forward_tunnel(local_port, remote_host, remote_port, client.get_transport())
        except KeyboardInterrupt:
            print 'C-c: Port forwarding stopped.'
            sys.exit(0)
    
    if __name__ == '__main__':
        forward(3306,"ssh.company.com",22,"admin","pwd","172.24.23.21",3306)

先启动转发服务。

通过代理连接数据库服务器 test.py:

conn=MySQLdb.connect(host="127.0.0.1", port=3306, user="user", passwd="pwd", db="db",
                                  connect_timeout=1000, charset="GBK")
    cur=conn.cursor()
    cur.execute("""select * from temp limit 5""");
    for c in cursor:
         print c
    cur.close();
    conn.close()

注意，这里是先向本地3306发送数据，本地转发服务接收到数据后会转发给SSHD服务，SSHD服务会帮我们将数据转发到目标服务器，得到响应后再原路返回。

[0_1324008339dO9h.gif]: /images/20220617/c587065ac4da4084bfbea16391863b63.png