Develop Reference

socket is not listening for multiple request

Here is the code for server -
import socket, select,re
def getSocket( idd):
return CONNECTION_LIST[idd]
def broadcast_data (sock, message):
for socket in CONNECTION_LIST:
if socket != server_socket and socket != sock :
try :
socket.send(message)
except :
socket.close()
CONNECTION_LIST.remove(socket)
def single_client (sock , message , idd):
socket = getSocket ( idd )
if socket :
socket.send(message)
else:
print "chudap"
if __name__ == "__main__":
CONNECTION_LIST = []
RECV_BUFFER = 4096
PORT = 5000
PORTC = 2225
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind(("0.0.0.0", PORT))
server_socket.listen(10)
listen = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
listen.bind(("0.0.0.0" , PORTC))
#listen.listen(10)
CONNECTION_LIST.append(server_socket)
CONNECTION_LIST.append(listen)
print "Chat server started on port " + str(PORT)
idd = 1
while 1:
# Get the list sockets which are ready to be read through select
read_sockets,write_sockets,error_sockets = select.select(CONNECTION_LIST,[],[])
for sock in read_sockets:
if sock == server_socket:
sockfd, addr = server_socket.accept()
CONNECTION_LIST.append(sockfd)
#name = sockfd.recv(RECV_BUFFER)
print "connected from ip %s, id assigned is %d" % (addr[0] , idd)
broadcast_data(sockfd, "client with IP %s has entered with id = %d\n" % (addr[0] , idd))
idd += 1
elif sock == listen:
print "debugging"
data,addr = listen.recvfrom(RECV_BUFFER)
print "Received server probe request from [%s:%s]"%addr
listen.sendto("iam" , addr)#(addr[0] , 2624))
listen.close()
CONNECTION_LIST.remove(listen)
listen = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
listen.bind(("0.0.0.0" , PORTC))
CONNECTION_LIST.append(listen)
else:
try:
data = sock.recv(RECV_BUFFER)
if re.findall(r'.*/msg\d+' , data):
#print "got single client message request" + data
name = "private message from " + re.findall('([^:]+): /msg(\d+)([^"]+)' , data)[0][0] + ": "
#print name
eid = int(re.findall('([^:]+): /msg(\d+)([^"]+)' , data)[0][1])
#print eid
data = re.findall('([^:]+): /msg(\d+)([^"]+)' , data)[0][2]
#print data
data = name + data
#print "single client message sent with id = %d" %eid
single_client( sock , data , int(eid))
elif data:
broadcast_data(sock, data)
except:
broadcast_data(sock, "Client (%s, %s) is offline" % addr)
print "Client (%s, %s) is offline" % addr
sock.close()
CONNECTION_LIST.remove(sock)
continue
server_socket.close()
Here is the code for client -
import socket, select, string, sys
def prompt() :
sys.stdout.write('<You>: ')
sys.stdout.flush()
def exit(sock):
print "\n Thank you for using chat application\nBye"
sock.close()
sys.exit()
def printUsage():
print "1. By default your message will be sent to all clients sitting on the chat server"
print "2. You can send a private message to a person by starting your message as \"/msg{id}{Your message}\" for example /msg2Hi will send \"hi\" to client with id 2"
print "3. For quitting simply type \"/q\" or \"/quit\""
prompt()
PORTS = 2225
PORTC = 2624
if __name__ == "__main__":
broad = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
broad.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
broad.bind(( '0.0.0.0' , 2624) )
broad.sendto(b'whoisserver', 0, ("255.255.255.255", PORTS))
broad.settimeout(10)
print 15*"-" + "WELCOME TO CHATVILLE" + 15*"-" + "\nFinding the server"
try:
data , addr = broad.recvfrom(10)
except:
print "Can't find server ! Please ensure that server is up"
broad.close()
sys.exit()
broad.close()
if data <> "iam":
print "Can't find a valid server !"
sys.exit()
host = addr[0]
port = 5000
print addr
# host = sys.argv[1]
# port = int(sys.argv[2])
# print host,port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(2)
name = raw_input("Please Enter your name: ")
try :
s.connect((host, port))
s.send(name)
except :
print 'Unable to connect'
sys.exit()
print 'Connected to remote host. Enjoy...............................'
name = "<" + name + ">" + ": "
print " - type /h to see usage instructions any time :) - "
prompt()
while 1:
socket_list = [sys.stdin, s]
read_sockets, write_sockets, error_sockets = select.select(socket_list , [], [])
for sock in read_sockets:
if sock == s:
data = sock.recv(4096)
if not data :
print '\nDisconnected from chat server'
sys.exit()
else :
print ""
sys.stdout.write(data)
prompt()
else :
msg = sys.stdin.readline()
if str.startswith(msg, "/h") or str.startswith(msg,"/help"):
printUsage()
elif str.startswith(msg, "/quit") or str.startswith(msg,"/q"):
exit(s)
else:
msg = name + msg
s.send(msg)
prompt()
Main problem is that only one client is able to connect as soon as the first client connects are to server no other client is able to discover the server.
I tried by looking at the client's code by tcpdump and I can see the packet going at port number 2225, but the socket listen is not responding at all after the first connection.
PS - earlier I was not making instance of listen socket again and again but I tried this also and it didn't work out.

In the sever broadcast_data() does not exclude the UDP socket (listen) from the sockets to write to, and so it calls send() on that socket. This fails with exception
socket.error: [Errno 89] Destination address required
because no address is supplied (and can't be with socket.send()). The exception handler then closes the UDP socket and no further messages from new clients can be received. That's why additional clients can not connect to the server.
This is a perfect example of why it is not a good idea to use a bare except, i.e. an except statement that handles all exceptions. In this case the handler closes the UDP socket without even logging the fact. There are other instances of bare except statements in your code. I suggest that you handle specific exceptions to avoid this sort of bug. You can fix it by adding the UDP socket to the list of sockets to ignore:
def broadcast_data(sock, message):
for socket in CONNECTION_LIST:
if socket not in (server_socket, sock, listen):
try :
socket.send(message)
except socket.error as exc:
print '!!! An error occurred while writing to client. !!!'
print exc
socket.close()
CONNECTION_LIST.remove(socket)
Now no attempt will be made to send messages to the UDP listen socket, and the socket won't be closed due to error.
P.S. the code in your main loop that closes and reopens the listen socket is not necessary.

Add username input to python chat program

So I found this chat program on http://www.bogotobogo.com/python/python_network_programming_tcp_server_client_chat_server_chat_client_select.php
And I want to use this at my school for me and my friends, put I don't want to chat to be ex: [192.168.1.3] "Message". I want to be able to add another argument so it shows there name they input instead of Ip. It would be a little hard to have everyone using ips. Any suggestions?
Server Code:
# chat_server.py
import sys
import socket
import select
HOST = ''
SOCKET_LIST = []
RECV_BUFFER = 4096
PORT = 9009
def chat_server():
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((HOST, PORT))
server_socket.listen(10)
# add server socket object to the list of readable connections
SOCKET_LIST.append(server_socket)
print "Chat server started on port " + str(PORT)
while 1:
# get the list sockets which are ready to be read through select
# 4th arg, time_out = 0 : poll and never block
ready_to_read,ready_to_write,in_error = select.select(SOCKET_LIST,[],[],0)
for sock in ready_to_read:
# a new connection request recieved
if sock == server_socket:
sockfd, addr = server_socket.accept()
SOCKET_LIST.append(sockfd)
print "Client (%s, %s) connected" % addr
broadcast(server_socket, sockfd, "[%s:%s] entered our chatting room\n" % addr)
# a message from a client, not a new connection
else:
# process data recieved from client,
try:
# receiving data from the socket.
data = sock.recv(RECV_BUFFER)
if data:
# there is something in the socket
broadcast(server_socket, sock, "\r" + '[' + str(sock.getpeername()) + '] ' + data)
else:
# remove the socket that's broken
if sock in SOCKET_LIST:
SOCKET_LIST.remove(sock)
# at this stage, no data means probably the connection has been broken
broadcast(server_socket, sock, "Client (%s, %s) is offline\n" % addr)
# exception
except:
broadcast(server_socket, sock, "Client (%s, %s) is offline\n" % addr)
continue
server_socket.close()
# broadcast chat messages to all connected clients
def broadcast (server_socket, sock, message):
for socket in SOCKET_LIST:
# send the message only to peer
if socket != server_socket and socket != sock :
try :
socket.send(message)
except :
# broken socket connection
socket.close()
# broken socket, remove it
if socket in SOCKET_LIST:
SOCKET_LIST.remove(socket)
if __name__ == "__main__":
sys.exit(chat_server())
Client Code:
# chat_client.py
import sys
import socket
import select
def chat_client():
if(len(sys.argv) < 3) :
print 'Usage : python chat_client.py hostname port'
sys.exit()
host = sys.argv[1]
port = int(sys.argv[2])
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(2)
# connect to remote host
try :
s.connect((host, port))
except :
print 'Unable to connect'
sys.exit()
print 'Connected to remote host. You can start sending messages'
sys.stdout.write('[Me] '); sys.stdout.flush()
while 1:
socket_list = [sys.stdin, s]
# Get the list sockets which are readable
ready_to_read,ready_to_write,in_error = select.select(socket_list , [], [])
for sock in ready_to_read:
if sock == s:
# incoming message from remote server, s
data = sock.recv(4096)
if not data :
print '\nDisconnected from chat server'
sys.exit()
else :
#print data
sys.stdout.write(data)
sys.stdout.write('[Me] '); sys.stdout.flush()
else :
# user entered a message
msg = sys.stdin.readline()
s.send(msg)
sys.stdout.write('[Me] '); sys.stdout.flush()
if __name__ == "__main__":
sys.exit(chat_client())

Python Socket Connection

I want to connect computers what is not in my lan. I want to connect real ip.
My server Code
import json
import os
import select
import socket
import sys
import urllib
import urllib.request
from optparse import OptionParser
ip = json.loads(urllib.request.urlopen('http://httpbin.org/ip').read().decode("utf-8"))['origin']
print(ip)
def isAlive(ip):
ret = os.system("ping -o -c 3 -W 3000 " + ip)
if ret != 0:
return True
return False
HOST = socket.gethostname()
SOCKET_LIST = []
RECV_BUFFER = 1024
PORT = 1993
def chat_server():
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.bind((HOST, PORT))
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.listen(10)
# add server socket object to the list of readable connections
SOCKET_LIST.append(server_socket)
print("Chat server started on port " + str(PORT), "on Host " + str(HOST))
print(SOCKET_LIST)
while True:
ready_to_read, ready_to_write, in_error = select.select(SOCKET_LIST, [], [], 0)
for sock in ready_to_read:
if sock == server_socket:
sockfd, addr = server_socket.accept()
SOCKET_LIST.append(sockfd)
print("Client (%s, %s) connected" % addr)
broadcast(server_socket, sockfd, "[%s:%s] entered our chatting room\n" % addr)
else:
try:
data = sock.recv(RECV_BUFFER)
recvString = data.decode("utf-8")
print(recvString)
if data:
broadcast(server_socket, sock, "\r" + '[' + str(sock.getpeername()) + '] ' + data)
else:
if sock in SOCKET_LIST:
SOCKET_LIST.remove(sock)
broadcast(server_socket, sock, "Client (%s, %s) is offline\n" % addr)
except:
broadcast(server_socket, sock, "Client (%s, %s) is offline\n" % addr)
continue
server_socket.close()
def broadcast(server_socket, sock, message):
for socket in SOCKET_LIST:
if socket != server_socket and socket != sock:
try:
socket.send(message)
except:
socket.close()
if socket in SOCKET_LIST:
SOCKET_LIST.remove(socket)
if __name__ == "__main__":
sys.exit(chat_server())
Connection Code
import socket
print(socket.getaddrinfo("localhost", 80, 0, 0, socket.SOL_TCP))
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print("Socket successfully created")
print(socket.gethostbyname(socket.gethostname()))
except socket.error as err:
print("socket creation failed with error %s" % (err))
port = 1993
host_ip = '193.140.109.2'
s.connect((host_ip, port))
while True:
getGet = input("Send Data: ")
s.sendall(bytearray(getGet, 'utf8'))
if getGet == '-':
s.close()
I wrote this code but I cannot connect my pc. I have some questions.
1- Is sockets only for lan connection ?
2- How can i connect diffrent computer ?

s = socket.socket(socket.AF_INET6, socket.SOCK_STREAM, 0)
port = 1993
host_ip = 'fe80::d862:a887:2f4c:53d0%12'
Solved my problem.

trying to bind to specific external ip:: [Errno 10049] The requested address is not valid in its context could not open socket-(python 2.7)

I have a Moxa device that create Tcp-ip message from serial data and send them to me by LAN.
i need to listen to hes specific external-ip(172.16.0.77) with python server.
ill try to do this:
BUFFER_SIZE = 10000 # Normally 1024, but we want fast response
HOST = self.TCP_IP #(172.16.0.77)
PORT = self.TCP_PORT # Arbitrary non-privileged port
s = None
for res in socket.getaddrinfo(HOST, PORT, socket.AF_UNSPEC,
socket.SOCK_STREAM, 0, socket.AI_PASSIVE):
af, socktype, proto, canonname, sa = res
try:
s = socket.socket(af, socktype, proto)
except socket.error as msg:
print msg
s = None
continue
try:
s.bind(sa)
s.listen(1)
except socket.error as msg:
print msg
s.close()
s = None
continue
break
if s is None:
print 'could not open socket'
while s:
print s.getsockname()
conn, addr = s.accept()
print 'Connection address:', addr
data = conn.recv(BUFFER_SIZE)
if data:
self.emit(QtCore.SIGNAL("SamplesRecive"),data)
conn.close()
and i get : [Errno 10049] The requested address is not valid in its context could not open socket
I need to divide the serves to many Moxa devices so i cant use socket.INADDR_ANY
Any ideas?

socket.INADDR_ANY equal to socket.bind('0.0.0.0')
if bind to "0.0.0.0" can listen all interfaces(which avaible)
Example of Moxa TCP :
import socket,time
import thread
#Example client
class _client :
def __init__(self):
self.status = False
def run(self,clientsock,addr):
while 1 :
try:
data = clientsock.recv(BUFF)
if data :
#do something with data
time.sleep(.1)
if self.status == False:
clientsock.close()
break
clientsock.send(next_query)
except Exception,e :
print e
break
client = _client()
ADDR = ("0.0.0.0", 45500) #so you need port how to decode raw socket data ?
serversock = socket(AF_INET, SOCK_STREAM)
serversock.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
serversock.setsockopt(IPPROTO_TCP, TCP_NODELAY, 1)#gain 50ms tcp delay
serversock.bind(ADDR)
serversock.listen(10)
While True :
clientsock, addr = serversock.accept()
if addr[0] == device_1_IP:
client.status = True
#start device1 thread(moxa is TCP client mode)
thread.start_new_thread(client.run, (clientsock, addr))
#if client.status = False you will be close connection.
But my offer is "use moxa with TCP server mode"
i am used 4x5450i 3x5250 over 120 device without any error.

Python Non-blocking peer to peer chat socket.error: [Errno 32] Broken pipe

Hi i write simple chat program for peer to peer chat between server and client.
This code is working for Client side and client can send message and server recives that messages. but for server side when i want to send a message i have error in line 40
File "server.py", line 40, in <module>
newSocket.send('\r<Server>: ' + msg)
socket.error: [Errno 32] Broken pipe
and server crashes.
Server :
import socket
import os
import select
import sys
def prompt():
sys.stdout.write('Server : ')
sys.stdout.flush()
try:
newSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
newSocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
except:
print 'socket Error'
sys.exit(1)
newSocket.bind(('127.0.0.1', 8000))
newSocket.listen(5)
input_list = [newSocket, sys.stdin]
print 'Chat Program'
prompt()
while True:
inputready, outputready, exceptready = select.select(input_list,[],[])
for sock in inputready:
if sock == newSocket:
(client, (ip, port)) = newSocket.accept()
input_list.append(client)
data = client.recv(2048)
if data:
sys.stdout.write(data)
elif sock == sys.stdin:
msg = sys.stdin.readline()
newSocket.send('\r<Server>: ' + msg)
prompt()
else:
data = sock.recv(2048)
if data:
sys.stdout.write(data)
newSocket.close()
client :
import socket
import os
import select
import sys
def prompt():
sys.stdout.write('Client ')
sys.stdout.flush()
try:
newSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
newSocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
except:
print 'socket Error'
sys.exit(1)
newSocket.connect(('127.0.0.1', 8000))
print 'Connected to remote host. Start sending messages'
prompt()
while 1:
socket_list = [sys.stdin, newSocket]
read_sockets, write_sockets, error_sockets = select.select(socket_list, [], [])
for sock in read_sockets:
if sock == newSocket:
data = sock.recv(4096)
if not data:
print '\nDisconnected from chat server'
sys.exit()
else:
sys.stdout.write(data)
prompt()
else:
msg = sys.stdin.readline()
newSocket.send('\r<Client>: ' + msg)
prompt()

You should use accept(). It seems newSocket is not ready to output when you try to .send() with it.

I change Server code to this and problem has been solved:
import socket
import select
import sys
CONNECTION_LIST = []
RECV_BUFFER = 4096
PORT = 1245
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind(('0.0.0.0', PORT))
server_socket.listen(5)
CONNECTION_LIST.append(server_socket)
CONNECTION_LIST.append(sys.stdin)
print 'Chat server Started on port ' + str(PORT)
def broadcast_data(sock, message):
for socket in CONNECTION_LIST:
if socket != server_socket and socket != sock and socket != sys.stdin:
try:
socket.send(message)
except:
socket.close()
CONNECTION_LIST.remove(socket)
def prompt() :
sys.stdout.write('<You> ')
sys.stdout.flush()
prompt()
while True:
read_sockets, write_sockets, error_sockets = select.select(CONNECTION_LIST, [], []) # NON_blocking I/O with 0
for sock in read_sockets:
if sock == server_socket:
# new Connection
sockfd, addr = server_socket.accept()
CONNECTION_LIST.append(sockfd)
print 'Clinet (%s, %s) connected ' % addr
broadcast_data(sockfd, "[%s:%s] entered room" % addr)
elif sock == sys.stdin:
msg = sys.stdin.readline()
broadcast_data(sock, 'Server > ' + msg)
prompt()
else:
try:
#In Windows, sometimes when a TCP program closes abruptly,
# a "Connection reset by peer" exception will be thrown
data = sock.recv(RECV_BUFFER)
if data:
print "\r" + '<' + str(sock.getpeername()) + '>' + data
broadcast_data(sock, "\r" + '<' + str(sock.getpeername()) + '>' + data)
except:
broadcast_data(sock, "Client (%s, %s) is offline" % addr)
print "Client (%s, %s) is offline" % addr
sock.close()
CONNECTION_LIST.remove(sock)
continue