I have learned the differences between the two infamous errors in tcp:
[Errno 54] Connection reset by peer
[Errno 32] Broken pipe
Both errors are one side of the tcp connection closed for unknown reason, and the other side still communicate with it.
when the other side write something, Broken pipe is thrown
when the other side read something, Connection reset by peer is thrown
I was able to reproduce Broken pipe using Python codes below.
# tcp_server.py
def handler(client_sock, addr):
try:
print('new client from %s:%s' % addr)
finally:
client_sock.close() # close current connection directly
if __name__ == '__main__':
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(('', 5500))
sock.listen(5)
while 1:
client_sock, addr = sock.accept()
handler(client_sock, addr)
As for client,
>>> sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
>>> sock.connect(('', 5500))
>>> sock.send('a')
1
>>> sock.send('a')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
socket.error: [Errno 32] Broken pipe
When the client first send, a RST packet is sent from server to client, from this moment on, send will always throw Broken pipe.
Everything above is within my understanding. However when client read from server , it always return empty string instead of throw Connection reset by peer
>>> sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
>>> sock.connect(('', 5500))
>>> sock.recv(1024)
''
>>> sock.recv(1024)
''
>>> sock.recv(1024)
''
>>> sock.recv(1024)
I am confused at this, or generally how to reproduce the Connection reset by peer ?
You can set the socket "linger" option to 0 and close the socket to send a reset. Updating your server
import socket
import struct
import time
# tcp_server.py
def handler(client_sock, addr):
try:
print('new client from %s:%s' % addr)
time.sleep(1)
finally:
client_sock.setsockopt(socket.SOL_SOCKET, socket.SO_LINGER,
struct.pack('ii', 1, 0))
client_sock.close() # close current connection directly
if __name__ == '__main__':
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('', 5500))
sock.listen(5)
while 1:
client_sock, addr = sock.accept()
handler(client_sock, addr)
And running this client
import socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('', 5500))
print(sock.recv(1024))
I got
Traceback (most recent call last):
File "tcpclient.py", line 5, in <module>
print(sock.recv(1024))
ConnectionResetError: [Errno 104] Connection reset by peer
Related
import socket
import threading
bind_ip = '192.168.43.233'
print(f"[*] connecting to " + bind_ip)
bind_port = 443
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.listen(5)
print(f"[*] Listening on %s:%d" % (bind_ip,bind_port))
def handle_client(client_socket):
request = client_socket.recv(1024)
print(f"[*] Recieved: %s" % request)
client_socket.send("ACK!")
client_socket.close()
while True:
client,addr = server.accept()
print(f"[*] Accepted connection from: %s:%d" % (addr[0],addr[1]))
client_handler = threading.Thread(target=handle_client,args=(client,))
client_handler.start()
says this when running
Traceback (most recent call last):
File "C:/Users/Red/PycharmProjects/untitled4/TCP SERVEr.py", line 9, in <module>
server.listen(5)
OSError: [WinError 10022] An invalid argument was supplied
any help with this so much appreciated ive been dealing with this for days now and looked everywhere but found nothing
You can't call server.listen() until you bind the socket to a port.
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((bind_ip, bind_port))
server.listen(5)
You need to bind the socket before server.listen(5).
connection.bind((bind_ip, bind_port))
I am new at socket programming. I am trying to make simple client server program, so I wrote this code:
This is the server program.
import socket
HOST = ''
PORT = 50007
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr=s.accept()
print('Connected by',addr)
while True:
data=conn.recv(1024)
if not data:
break
conn.send(data)
conn.close()
This is client program:
import socket
HOST = '10.87.24.139'
PORT = 50007
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.send('Hello World')
s.close()
print('received', repr(data))
When I run this the client shows this error:
Traceback (most recent call last):
File "C:\Users\James Bond\Desktop\client.py", line 6, in <module>
s.connect((HOST, PORT))
TimeoutError: [WinError 10060] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond
Where is the problem? Why did this error occur?
This is a simple file server file using TCP sockets,
when i'm running this i'm getting the following error.
Can anyone tell me the solution to this
import socket # Import socket module
s = socket.socket() # Create a socket object
host = socket.gethostname() # Get local machine name
port = socket.getsockname() # Reserve a port for your service.
block_size = 1024 #file is divided into 1kb size
s.bind((host, port)) # Bind to the port
#f = open('paris.png','wb')
s.listen(5) # Now wait for client connection.
while True:
c, addr = s.accept() # Establish connection with client.
print('Got connection from', addr)
print("Receiving...")
l = c.recv(block_size)
while (l):
print("Receiving...")
l = c.recv(block_size)
#f.close()
print("Done Receiving")
mssg = 'Thank You For Connecting'
c.send(mssg.encode())
c.close() # Close the connection
Traceback (most recent call last):
File "C:\Users\Hp\Documents\Python codes\file_transfer_simple_server.py",line 5, in <module>
port = socket.getsockname() # Reserve a port for your service.
AttributeError: module 'socket' has no attribute 'getsockname'
As #Mark Tolonen mentioned in the comment, You were calling getsockname() on the socket module. getsockname is a method on the socket instance s
import socket
s = socket.socket()
s.bind(('localhost',12345))
host, port = s.getsockname() # unpack tuple
block_size = 1024
print(port)
# output
12345
I would like to listen on 100 different TCP port with the same server. Here's what I'm currently doing:-
import socket
import select
def main():
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
for i in range(1000,1100):
server_socket.bind(('127.0.0.1', i))
server_socket.listen(1)
read_list = [server_socket]
while True:
readable, writable, exceptional = select.select(read_list, [], read_list)
for s in readable:
if s is server_socket:
#print "client connected"
client_socket, address = server_socket.accept()
read_list.append(client_socket)
else:
# One of the tcp clients
data = s.recv(1024)
if not result:
s.close()
read_list.remove(s)
#print "client disconnected"
if __name__ == "__main__":
main()
It returns an error saying Permission Denied. Is it because some ports(1000-1100) are reserved and are not allocated to it or because of some other reason?
I tried with (8000-8100) and it says Invalid Arguments
EDITED
import socket
import select
def create_socket(TCP_PORT):
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind(('127.0.0.1', TCP_PORT))
server_socket.listen(1)
return server_socket
def main():
read_list = []
for TCP_PORT in range(8000,8100):
read_list.append(create_socket(TCP_PORT))
while True:
readable, writable, exceptional = select.select(read_list, [], read_list)
for s in readable:
if s is server_socket:
#print "client connected"
client_socket, address = server_socket.accept()
read_list.append(client_socket)
else:
# One of the tcp clients
data = s.recv(1024)
if not result:
s.close()
read_list.remove(s)
#print "client disconnected"
if __name__ == "__main__":
main()
There are 2 problems.
Ports below 1024 are reserved. (You'll need special privileges, e.g. root privileges to bind to such a port).
A socket can only listen at one port. So to listen to several port, you need to create one socket per port.
You will find a nice explaination here : Listen to multiple ports from one server. It is for C but the problem in python is the same.
So the answer will be the same :
one socket per port
one listen per socket
a single select
By the way ports below 1024 ar reserved on Unix (and Unix-like) systems : you need root privileges to use them. On Windows, there are no such restrictions.
Regarding the second problem - using ports 8000-8100 causes Invalid argument, this occurs if you try to rebind an already bound socket without first recreating the socket. There is no problem with that port range however.
>>> s=socket.socket()
>>> s.bind(('localhost', 8001))
>>> s.bind(('localhost', 8001))
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib64/python2.7/socket.py", line 224, in meth
return getattr(self._sock,name)(*args)
socket.error: [Errno 22] Invalid argument
>>> s.close()
>>> s.bind(('localhost', 8001))
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib64/python2.7/socket.py", line 224, in meth
return getattr(self._sock,name)(*args)
File "/usr/lib64/python2.7/socket.py", line 170, in _dummy
raise error(EBADF, 'Bad file descriptor')
socket.error: [Errno 9] Bad file descriptor
>>> s=socket.socket()
>>> s.bind(('localhost', 8001))
I'm trying to implement a non-blocking python tcp server which listens on multiple ports.
I found some code in this Stackover posting and modified it to listen on multiple sockets, so far, so good.
My code is as follows.
#!/usr/bin/python
import select
import socket
ports_list=[7777,7778]
def make_socket(number):
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('', number))
sock.listen(5)
return sock
read_list= map(lambda x: make_socket(x), ports_list)
print(read_list)
print "Listening on port %s" % ports_list
while True:
readable, writable, errored = select.select(read_list, [], [])
for s in readable:
if s in read_list:
client_socket, address = s.accept()
read_list.append(client_socket)
print "Connection from", address
else:
data = s.recv(1024)
if data:
s.send(data)
else:
s.close()
read_list.remove(s)
I test it by running netcat in another console
$ netcat localhost 7778
dsa
But it borks, like so:
/tcp_non_blocking_listener.py
[<socket._socketobject object at 0xb72804fc>, <socket._socketobject object at 0xb7280534>]
Listening on port [7777, 7778]
Connection from ('127.0.0.1', 41237)
Traceback (most recent call last):
File "./tcp_non_blocking_listener.py", line 27, in <module>
client_socket, address = s.accept()
File "/usr/lib/python2.7/socket.py", line 202, in accept
sock, addr = self._sock.accept()
socket.error: [Errno 22] Invalid argument
I'm just getting started on python non-blocking API, what is the idiomatic way to do something like this?
You mismatch not accepted sockets with already accepted.
your fixed code (introduced list with notAccepted sockets):
#!/usr/bin/python
import select
import socket
ports_list=[7777,7778]
def make_socket(number):
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('', number))
sock.listen(5)
return sock
read_list= map(lambda x: make_socket(x), ports_list)
print(read_list)
print "Listening on port %s" % ports_list
notAccepted = read_list[:]
while True:
readable, writable, errored = select.select(read_list, [], [])
for s in readable:
if s in notAccepted:
client_socket, address = s.accept()
read_list.append(client_socket)
print "Connection from", address, client_socket
else:
data = s.recv(1024)
if data:
s.send(data)
else:
s.close()
read_list.remove(s)
As is accept().
For UDP, you don't have "connections", so there's no accept().
Use sendto() and recvfrom() and SOCK_DATAGRAM.
Other than whatever context the application may apply and/or embed in the payload, there is no relationship in the protocol between one UDP datagram and the next from the same host. No guarantees that multiple datagrams from the same host and the same source/dest addr/port tuple are related to the same client application. It's completely connectionless and therefore any state must be managed entirely by the application and the contents of the payload.