Сломанная труба и соединение отказались от ошибок

Question

Я пытаюсь создать разумный netcat самостоятельно (все еще довольно новый), добавив дополнительный импорт, флаги и т. д. с помощью модулей netcat и python, мне удалось отладить несколько ошибок, но изменение одной строки кода дает мне 2 разных ошибки. Гугл, ища их обоих, я понял, что может быть много вариантов, почему я получаю это... я надеялся, что кто-то здесь может помочь мне найти точно, какой это вариант.

Мой код:

#import the modules you need
import sys
import os
import threading
import socket
import getopt
import time
import subprocess

#set global variables
lis  = False
com  = False
up   = False
tar  = ""
exe  = ""
up_d = ""
pt   = 0

#runs a command and returns output
def run_com(com):
    #trims the newline
    com = com.rstip()

    #get the output after running the command
    try:
        output = subprocess.check_output(com,stderr=subprocess.STDOUT, shell=True)
    except:
        output = "Failed to execute.\r\n"

    #send output back to client
    return output

def netcat(tar,pt,content):

    #if no target is defined listen on all interfaces
    if not len(tar):
        tar = "0.0.0.0"

    #initialize the connection
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((tar,pt))

    sock.listen(5)
    sock.sendall(content)

    while True:
        client_socket, addr = sock.accept()

        #spin off a thread to handle the new client
        client_thread = threading.Thread(target=client_handler,args=(client_socket,))
        client_thread.start()

    res = ""

    while True:
        data = sock.recv(1024)

        if (not data):
            break
        res += data.decode()

    print(res)

    print("Connection closed.")
    sock.close()

content = "GET / HTTP/1.1\nHost: google.com\n\n"
netcat(tar,pt,content.encode())

#create a raw socket and bind it to the public interface
def sniffer():
    if os.name == "nt":
        socket_protocol = socket.IPPROTO_IP 
    else:
        socket_protocol = socket.IPPROTO_ICMP

    sniffer = socket.socket(socket.AF_INET,socket.SOCK_RAW,socket_protocol)
    sniffer.bind((hn,p))

    #include the IP headers in the capture
    sniffer.setsockopt(socket.IPPROTO_IP,socket.IP_HDRINCL,1)

    #if using windows, send an IOCTL to set up promiscuous mode
    if os.name == "nt":
        sniffer.icotl(socket.SIO_RCVALL,socket.RCVALL_ON)

    #read a single packet
    print (sniffer.recvfrom(65565))

    #turn off promiscious mode if still using windows
    if os.name == "nt":
        sniffer.ioctl(socket.SIO_RCVALL,socket.RCVALL_OFF)

def sleeper():
    while True:
        #get user input
        num = input('How long to wait: ')

        #try to convert it to a float
        try:
            num = float(num)
        except ValueError:
            print('Please enter in a number.\n')
            continue

        #run time.sleep() and show the before/after time
        print('Before: %s' % time.ctime())
        time.sleep(num)
        print('After: %s\n' % time.ctime())

try:
    sleeper()
except KeyBoardInterrupt:
    print('\n\nKeyboard exception received. Exiting.')
    exit()

def client_handler(client_socket):
    global up
    global exe
    global com

    #checking for upload
    if len(up_d):
        #read in all the bytes and write to the destination
        file_buff = ""

        #keep reading until none left
        while True:
            data = client_socket.recv(1024)

            if (not data):
                break
            else:
                file_buff += data.decode()

        #now take the bytes and try to write them out
        try:
            file_desc = open(up_d,"wb")
            file_desc.write(file_buff)
            file_desc.close()

            #acknowledge it's been written
            client_socket.send("Success! file saved to %s\r\n" % up_d)
        except:
            client_socket.send("Failed! file wasn't saved to %s\r\n" % up_d)

    #check for command execution
    if len(exe):
        #run command
        output = run_com(exe)
        client_socket.send(output)

    #if shell was requested go into another loop
    if com:

        while True:
            #show a prompt
            client_socket.send("<action:#>")

            #now receieve until a linefeed is seen
            cmd_buff = ""

            while ("\n" not in cmd_buff):
                cmd_buff += client_socket.recv(1024)

                #execute the command and send back results
                res = run_com(cmd_buff)

                #send back response
                client_socket.send(res)

#type netcat -h in the terminal to see the commandline options and change them to your liking
def usage():
    print ("netcat python3")
    print 
    print ("Usage: netcat3.py -t target_host -p port")
    print ("-l --listen              - listen on [host]:[port] for incoming connections")
    print ("-e --execute             - program to execute after connection")
    print ("-c --shell command       - initalize a command shell")
    print ("-u --upload=destination  - upon receving connection upload a file and write to[destination]")
    print 
    print ("Examples: ")
    print ("netcat3.py -t 127.0.0.1 -p 8080 -l -c")
    print ("netcat3.py -t 127.0.0.1 -p 8080 -l -u=c:\\target.exe")
    print ("netcat3.py -t 127.0.0.1 -p 8080 -l -e=\"cat /etc/passwrd\"")
    print ("echo 'HELLO' | python3 netcat3.py -t 45.56.155.187 -p 135")
    sys.exit(0)

def main():
    global lis
    global pt
    global exe
    global com
    global up_d
    global tar

    if not len(sys.argv[1:]):
        usage()

    #read the commandline options
    try:
        opts, args = getopt.getopt(sys.argv[1:],"hle:t:p:cu:",["help","lis","exe","tar","p","com","up"])
    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"):
            lis = True
        elif o in ("-e","--execute"):
            exe = a
        elif o in ("-c","--commandshell"):
            com = True
        elif o in ("-u","--upload"):
            up_d = a
        elif o in ("-t","--target"):
            tar = a
        elif o in ("-p","--port"):
            pt = int(a)
        else:
            assert False, "Unhandled Option"

    #listen or just send data from stdin?
    if not lis and len(tar) and pt > 0:
        #read the buffer from the commandline, send CTRL-D if not sending input to stdin
        buff = sys.stdin.read()

        #send off data
        client_sender(buffer)

    #depending on the commands in the options above might listen and potentially upload things
    #execute commands and drop a shell back
    if lis:
        serv_loop()

main()

Первая ошибка при наличии "sock.connect((tar,pt))":

 anon@kali:~/Desktop/python scripts$ python3 netcat3.py -l -p 9999 -c
Traceback (most recent call last):
  File "netcat3.py", line 68, in <module>
    netcat(tar,pt,content.encode())
  File "netcat3.py", line 41, in netcat
    sock.connect((tar,pt))
ConnectionRefusedError: [Errno 111] Connection refused

если я изменю строку, указанную выше, на "socket.bind((tar,pt))", ошибка будет такой:

    anon@kali:~/Desktop/python scripts$ python3 netcat3.py -l -p 9999 -c
Traceback (most recent call last):
  File "netcat3.py", line 68, in <module>
    netcat(tar,pt,content.encode())
  File "netcat3.py", line 44, in netcat
    sock.sendall(content)
BrokenPipeError: [Errno 32] Broken pipe

я знаю, что это может быть что-то простое, или я переусердствовал в своем коде, но что бы это ни было, я застрял в поиске главной проблемы, как пройти эту стену. Заранее спасибо за любую помощь, я действительно ценю это.