Python 编写一个Netcat

import socket
 
traget_host = "127.0.0.1"
traget_port = 9999
 
#建立socket对象
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#发起连接
client.connect((traget_host,traget_port))
#发送数据
client.send("GET / HTTP/1.1\r\nHost:127.0.0.1\r\n\r\n")
#取回数据
response = client.recv(4096)
 
print response

import socket
traget_host = "127.0.0.1"
traget_port = 9999
 
#建立socket对象
client = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
#UDP无需建立连接，直接发送数据
client.sendto("AABBCC",(traget_host,traget_port))
#接受数据
addr = client.recvfrom(4096)
 
print addr

import socket
import threading
 
ip   = "0.0.0.0"
port = 9999
 
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#绑定监听
server.bind((ip,port))
#设置连接数0-5，5为由系统分配
server.listen(5)
 
print "[*] Listen on %s:%d" % (ip,port)
 
#处理线程
def handle_client(c_socker):
    requset = c_socker.recv(1024)
    print "[*] Recv : %s" % requset
 
    c_socker.send("ACK!")
    c_socker.close()
 
while True:
    client,addr = server.accept()
    print "[*] Accept connection from: %s:%d" % (addr[0],addr[1])
 
    #挂起客户线程，处理传入数据    
    client_handler = threading.Thread(target=handle_client,args=(client,))
    client_handler.start()

#-*-coding:utf-8-*-
import sys
import socket
import getopt
import threading
import subprocess
 
#定义全局变量
listen = False
command = False
upload = ""
execute =""
target = ""
upload_destination = ""
port = 0
 
 
 
def client_sender(buffer):
    client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
 
    try:
        #连接到目标主机
        client.connect((target,port))
        if len(buffer):
            client.send(buffer)
 
        while True:
            #等待数据回传
            recv_len = 1
            response = ""
 
            while recv_len:
 
                date = client.recv(4096)
                recv_len = len(date)
                response += date
 
                if recv_len < 4096:
                    break
            print response,
 
 
            #等待更多的输入
            buffer = raw_input("")
            buffer += "\n"
 
            #发送出去
            client.send(buffer)
 
 
    except:
        print "[*] Execept error; exiting."
        client.close()
 
def server_loop():
        global target
        global port
 
        # if no target is defined we listen on all interfaces
        if not len(target):
                target = "0.0.0.0"
 
        server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        server.bind((target,port))
 
        server.listen(5)        
 
        while True:
                client_socket, addr = server.accept()
 
                # spin off a thread to handle our new client
                client_thread = threading.Thread(target=client_handler,args=(client_socket,))
                client_thread.start()
 
def run_command(command):
    #换行
    command = command.rstrip()
 
    #运行命令并输出返回
    try:
        output = subprocess.check_output(command,stderr=subprocess.STDOUT,shell=True)
    except:
        output = "Failed to execute command.\r\n"
 
    return output
 
def client_handler(client_socket):
    global upload
    global execute
    global command
 
    #检测上传文件
    if len(upload_destination):
 
        file_buffer = ""
        while True:
            data = client_socket.recv(1024)
            if not date:
                break
            else:
                file_buffer += data
        #打开文件并写出
        try:
            file_descriptr = open(upload_destination,"wb")
            file_descriptr.write(file_buffer)
            file_descriptr.close
 
            client_socket.send("Success saved file to %s\r\n" % upload_destination)
        except:
            client_socket.send("Failed to saved file to %s\r\n" % upload_destination)
 
    #如果是执行命令        
    if len(execute):
        output =run_command(execute)
        client_socket.send(output)
    #如果是SHELL，就进入另外一个循环
    if command:
        while True:
            #跳出一个窗口
            client_socket.send("<BHP:#>")
            #接受文件知道发现enter key
            cmd_buffer = ""
            while "\n" not in cmd_buffer:
                cmd_buffer += client_socket.recv(1024)
            response = run_command(cmd_buffer)
            client_socket.send(response)
 
def usage():
    print "Myfirst net tool"
    print
    print "usage:mynetcat.py -t target_host -p port"
    sys.exit(0)
 
def main():
    global listen
    global port
    global execute
    global command
    global upload_destination
    global target
 
    if not len(sys.argv[1:]):
        usage()
 
        #读取命令选项
    try:
            opts,args = getopt.getopt(sys.argv[1:],"hle:t:p:cu",["help","listen","execute",
                                    "target","port","command","upload"])
    except getopt.GetoptError as err:
            print str(err)
            usage()
 
    for o,a in opts:
        if o in ("-h","--help"):
            usage()
        elif o in ("-l","--listen"):
            listen = True
        elif o in ("-e","--execute"):
            execute = a
        elif o in ("-c","--commandshell"):
            command = True
        elif o in ("-u","--upload"):
            upload_destination = a
        elif o in ("-t","--traget"):    
            target = a
        elif o in ("-p","--port"):
            port = int(a)
        else:
            assert False,"unknow Option"
 
    #判断是在监听还是在终端输入数据        
    if not listen and len(target) and port > 0:
 
        buffer = sys.stdin.read()
        client_sender(buffer)
 
    if listen:
        server_loop()
 
main()