Socket代理转发小记

http://www.linuxso.com/architecture/13498.html

本地转发代码forward.py

#!/usr/bin/env pythonimport osimport socketimport selectimport SocketServerimport sysimport paramikodef verbose(s):        print sclass ForwardServer (SocketServer.ThreadingTCPServer):    daemon_threads = True    allow_reuse_address = Trueclass 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 ccur.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。