本文实例讲述了python实现端口转发器的方法。分享给大家供大家参考。具体如下：

下面的python代码实现端口转发器，支持udp端口转发

由于工作需要用到一个端口转发器，并且要求支持TCP和UDP协议。在网上找了蛮久，但没有中意的。于是就自己写了一个。这个转发器是基于python cookbook的一个示例改写的，原先的这个示例只支持TCP协议，我这里增加了UDP协议的支持，程序写的不怎么好，不过它确实能用！

portmap.py代码如下：

复制代码 代码如下:

- -coding: UTF-8 - -

'''
Created on 2012-5-8
@author: qh
'''
import time,socket,threading
def log(strLog):
strs=time.strftime("%Y-%m-%d %H:%M:%S")
print strs+"->"+strLog
class pipethread(threading.Thread):
'''
classdocs
'''
def init(self,source,sink):
'''
Constructor
'''
threading.Thread.init(self)
self.source=source
self.sink=sink
log("New Pipe create:%s->%s" % (self.source.getpeername(),self.sink.getpeername()))
def run(self):
while True:
try:
data=self.source.recv(1024)
if not data: break
self.sink.send(data)
except Exception ,ex:
log("redirect error:"+str(ex))
break
self.source.close()
self.sink.close()
class portmap(threading.Thread):
def init(self,port,newhost,newport,local_ip=''):
threading.Thread.init(self)
self.newhost=newhost
self.newport=newport
self.port=port
self.local_ip=local_ip
self.sock=None
self.sock=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
self.sock.bind((self.local_ip,port))
self.sock.listen(5)
log("start listen protocol:%s,port:%d " % ('tcp',port))
def run(self):
while True:
fwd=None
newsock=None
newsock,address=self.sock.accept()
log("new connection->protocol:%s,local port:%d,remote address:%s" % ('tcp',self.port,address[0]))
fwd=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
try:
fwd.connect((self.newhost,self.newport))
except Exception ,ex:
log("connet newhost error:"+str(ex))
break
p1=pipethread(newsock,fwd,self.protocol)
p1.start()
p2=pipethread(fwd,newsock,self.protocol)
p2.start()
class pipethreadUDP(threading.Thread):
def init(self,connection,connectionTable,table_lock):
threading.Thread.init(self)
self.connection=connection
self.connectionTable=connectionTable
self.table_lock=table_lock
log('new thread for new connction')
def run(self):
while True:
try:
data,addr=self.connection['socket'].recvfrom(4096)

log('recv from addr"%s' % str(addr))

        except Exception ,ex:  
            log("recvfrom error:"+str(ex))  
            break  
        try:  
            self.connection['lock'].acquire()  
            self.connection['Serversocket'].sendto(data,self.connection['address'])  
            #log('sendto address:%s' % str(self.connection['address']))  
        except Exception ,ex:  
            log("sendto error:"+str(ex))  
            break  
        finally:self.connection['lock'].release()  
        self.connection['time']=time.time()  
    self.connection['socket'].close()  
    log("thread exit for: %s" % str(self.connection['address']))  
    self.table_lock.acquire()  
    self.connectionTable.pop(self.connection['address'])  
    self.table_lock.release()  
    log('Release udp connection for timeout:%s' % str(self.connection['address']))  

class portmapUDP(threading.Thread):
def init(self,port,newhost,newport,local_ip=''):
threading.Thread.init(self)
self.newhost=newhost
self.newport=newport
self.port=port
self.local_ip=local_ip
self.sock=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
self.sock.bind((self.local_ip,port))
self.connetcTable={}
self.port_lock=threading.Lock()
self.table_lock=threading.Lock()
self.timeout=300

ScanUDP(self.connetcTable,self.table_lock).start()

    log('udp port redirect run->local_ip:%s,local_port:%d,remote_ip:%s,remote_port:%d' % (local_ip,port,newhost,newport))  
def run(self):  
    while True:  
        data,addr=self.sock.recvfrom(4096)  
        connection=None  
        newsock=None  
        self.table_lock.acquire()  
        connection=self.connetcTable.get(addr)  
        newconn=False  
        if connection is None:  
            connection={}  
            connection['address']=addr  
            newsock=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)  
            newsock.settimeout(self.timeout)  
            connection['socket']=newsock  
            connection['lock']=self.port_lock  
            connection['Serversocket']=self.sock  
            connection['time']=time.time()  
            newconn=True  
            log('new connection:%s' % str(addr))  
        self.table_lock.release()  
        try:  
            connection['socket'].sendto(data,(self.newhost,self.newport))  
        except Exception ,ex:  
            log("sendto error:"+str(ex))  
            #break  
        if newconn:  
            self.connetcTable[addr]=connection  
            t1=pipethreadUDP(connection,self.connetcTable,self.table_lock)  
            t1.start()  
    log('main thread exit')  
    for key in self.connetcTable.keys():  
        self.connetcTable[key]['socket'].close()  

if name=='main':
myp=portmapUDP(10061,'10.0.1.29',161)
myp.start()

myp.__stop()

希望本文所述对大家的Python程序设计有所帮助。