I'm currently trying to write process that embeds a sequence of n IPs into packets and send it off to n server. Each server remove the outermost IP and then forward it to said IP. This is exactly like tunneling I know. During the process I also want the server to do a traceroute to where it's forwarding the packet and send that back to the previous server.
My code currently will forward the packets but it's stuck on performing the traceroute and getting it. I believe it's currently stuck in the while loop in the intermediate server. I think it's having something to do with me not closing the sockets properly. Any suggestion?
Client
#!/usr/bin/env python
import socket # Import socket module
import sys
import os
s = socket.socket() # Create a socket object
host = socket.gethostname() # Get local machine name
port = 17353 # Reserve a port
FILE = raw_input("Enter filename: \n ")
NIP = raw_input("Enter Number of IPs: ")
accepted_IP = 0
IP= []
while accepted_IP < int(NIP):
IP.append(raw_input("Enter destination IP: \n"))
accepted_IP +=1
#cIP = raw_input("Enter intemediate IP: \n ")
ipv = raw_input("Enter IP version... 4/6")
try:
s.connect((host, port))
print "Connection sucessful!"
except socket.error as err:
print "Connection failed. Error: %s" %err
quit()
raw = open(FILE,"rb")
size = os.stat(FILE).st_size
ls = ""
buf = 0
for i in IP:
while len(i) < 15:
i += "$"
ls += i
header = ipv+NIP+ls+FILE
print ls
s.sendall(header + "\n")
print "Sent header"
data = raw.read(56) +ipv + NIP + ls
print "Begin sending file"
while buf <= size:
s.send(data)
print data
buf += 56
data = raw.read(56) + ipv + NIP + ls
raw.close()
print "Begin receiving traceroute"
with open("trace_log.txt","w") as tracert:
trace = s.recv(1024)
while trace:
treacert.write(trace)
if not trace: break
trace = s.recv(1024)
print "finished forwarding"
s.close()
Intermediate server
#!/usr/bin/env python
import socket
import subprocess
srvsock = socket.socket( socket.AF_INET, socket.SOCK_STREAM )
srvsock.bind( (socket.gethostname(), 17353) )
srvsock.listen( 5 ) # Begin listening with backlog of 5
# Run server
while True:
clisock, (remhost, remport) = srvsock.accept() #Accept connection
print
d = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
header = ""
while True:
b = clisock.recv(1)
if b == "\n":
break
header += b
num = 15 * int(header[1]) + 2
file_name = header[num:]
nheader = header[0]+ str(int(header[1])-1) + header[17:]
d.connect((socket.gethostname(), 12355))
d.sendall(nheader+'\n')
print "begin forwarding"
while True:
raw = clisock.recv(56 + num) # recieve data
ip = raw[-15:] # extract IP
ipv, NIP = raw[57] , str(int(raw[57])-1)
if NIP == "0":
while (raw):
print "stuck in this loop"
d.send(raw[:56])
raw=clisock.recv(56+num)
if not raw: break
else:
while (raw):
print raw[:57] + NIP + raw[59:-15]
print "\n"
d.send(raw[:57] + NIP + raw[59:-15])
raw = clisock.recv(56+num)
if not raw :break
print "Finish forwarding"
d.close()
break
print "Begin traceroute"
tracrt = subprocess.Popen(['traceroute','google.com'], stdout=subprocess.PIPE)
s.sendall(tracrt.communicate()[0])
print "Finished"
clisock.close()
s.close()
Destination server
import socket
s = socket.socket()
host = socket.gethostname()
port = 12355
s.bind((host,port))
s.listen(5)
while True:
csock, (client, cport) = s.accept()
print client
header = ""
while True:
b = csock.recv(1)
if b == "\n":
break
header += b
file_name = header[2:]
r = open("File_test_"+file_name,"wb")
print 'Opening file for writing'
while True:
print "Begin writing file" + " " + file_name
raw = csock.recv(56)
while (raw):
print raw
r.write(raw)
raw = csock.recv(56)
r.flush()
r.close()
print "finish writing"
break
print "closing connection"
csock.close()
s.close()
The intermediate server is stuck in clisock.recv() in this loop because the break condition not raw isn't met before the connection is closed by the client, and the client doesn't close the connection before receiving the traceroute from the intermediate server, so they are waiting on each other.
To remedy this, you might consider sending the file size to the intermediate server, so that it can be used to determine when the receive loop is done. Or, if your platform supports shutting down one half of the connection, you can use
s.shutdown(socket.SHUT_WR)
in the client after sending the file.
Related
I have two ubuntu machines, a server and a client. I am trying to get my client to send information to the server, have the server handle the info and respond with a message. My code is below. Right now, the "Message received" will print on the server side, but the "Message accepted" will not, which makes me think that the "conn, addr s.accept()" is the problematic line. Any help on discovering why the code isn't working would be helpful.
server.py
import socket
serverprivateIP = '172.31.89.96'
port = 54352
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind(("",port))
s.listen()
print("Message received")
conn, addr = s.accept()
print("Message accepted")
with conn:
while True:
data = conn.recv(8192)
if not data:
break
text = data.decode()
lines = 0
words = 0
characters = 0
for line in text:
line = line.strip("\n")
word = line.split()
lines += 1
words += len(word)
characters += len(line)
text.close()
toReturn = lines + " " + words + " " + characters + " "
conn.send(toReturn)
client.py
import socket
import os
serverIP = "3.89.222.117"
port = 54352
MAXBUFFER = 8192
file = "file.txt"
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.connect((serverIP,port))
with open(file,"rb") as filereader:
content = filereader.read(MAXBUFFER)
s.send(content)
results = s.recv(1024)
print(results.decode())
socket.close()
Server Side (server prints the first line of information sent from the client then it JUST STAYS open and doesn't seem to continue listening it just stays open. Is there a way to get the server to listen to the client more and print?)
import time
import socket
import signal
from datetime import datetime
serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversocket.bind(('localhost', 8089))
serversocket.listen(1024) # become a server socket, maximum 5 connectionn
def clientsocketentry():
while True:
connection, addr = serversocket.accept()
buf = connection.recv(64)
if not buf:
break
elif buf == 'killsrv':
connection.close()
sys.exit()
else:
print (buf)
buf = buf.decode("utf-8")
buf = buf.split(',')
serverLong = buf[0]
print('Longitude:' + '' + serverLong)
serverLat = buf[1]
print('Lattitude:' + '' + serverLat)
serverAlt = buf[2]
print('Altitude:' + '' + serverAlt)
serverTime = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
print('Time of Entry:' + ' ' + serverTime)
connection.close()
clientsocketentry()
Client Side (I am only able to send one of the strings of information then the server stays open ut does not take more information from the client)
import socket
import time
clientsocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
clientsocket.connect(('localhost', 8089))
a = '39.163100,-76.899428,0'
clientsocket.send(a.encode('utf-8'))
time.sleep(5)
a = '4.2,2.2415,0'
clientsocket.send(a.encode('utf-8'))
time.sleep(5)
a = '43454,354354,35435'
clientsocket.send(a.encode('utf-8'))
time.sleep(5)
a = '435742.,35.452,52434'
clientsocket.send(a.encode('utf-8'))
time.sleep(5)
clientsocket.close()
If you accept one single connection at a time (no need for a 1024 backlog then...) you can simply nest 2 loops: the outer one waiting for new connections the inner one processing input from the only one established connection. If you need to process more than one connection, you will have to use select or threads.
Here is an example for one single connection:
def clientsocketentry():
serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversocket.bind(('localhost', 8089))
serversocket.listen(5) # become a server socket, maximum 5 connectionn
cont = True
while cont:
connection, addr = serversocket.accept()
while True:
buf = connection.recv(64)
if len(buf) == 0: # end of connection
connection.close()
break
elif buf == b'killsrv': # request for closing server (beware of the byte string)
connection.close()
serversocket.close()
cont = False
break
else:
print (buf)
buf = buf.decode("utf-8")
buf = buf.split(',')
serverLong = buf[0]
print('Longitude:' + '' + serverLong)
serverLat = buf[1]
print('Lattitude:' + '' + serverLat)
serverAlt = buf[2]
print('Altitude:' + '' + serverAlt)
serverTime = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
print('Time of Entry:' + ' ' + serverTime)
# connection.close() # wait for client to close
You are closing the socket at the end of your print logic in the ClientSocketEntry function.
serverTime = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
print('Time of Entry:' + ' ' + serverTime)
connection.close()
Instead of closing the connection there only close it when the user sends killsrv
Because every time you close the connection on the socket it is saying that you are expecting another client to connect to the server. So maybe before going into the while statement accept the connection and then pass it into the while statement, because the way you have it structured at the moment is expecting multiple connections from different clients.
I want to send strings from a text file to my local port but i have to open connection and close it for each string. Therefore, data flow is very slow.(Almost in two seconds 1 string). How can i make it faster?
while 1:
conn, addr = s.accept()
line_number = random.randint(1,2261074)
liste.append(line_number)
line = linecache.getline(filename,line_number)
sendit = line.split(" ")[1]
print type(sendit)
print "sending: " + sendit
conn.send(sendit)
conn.close()
print('End Of Stream.')
The answer suggests sending 10 messages to Spark on each connection, separating each message by 1 second, then closing the connection.
It might be better to keep the connection open and use a non-blocking socket at the server end.
The server code below keeps the connection open, sending messages in batches on a non-blocking socket, with an idle delay between each batch.
This can be used to test how fast Spark can receive messages. I've set it to send in batches of 50 messages, then wait 1 second before sending the next 50.
Spark receives all messages OK on my machine, even if I set the idle delay to zero.
You can experiment and adjust as needed for your application.
Server code:
import socket
import time
import select
def do_send(sock, msg, timeout):
readers = []
writers = [sock]
excepts = [sock]
rxs, txs, exs = select.select(readers, writers, excepts, timeout)
if sock in exs:
return False
elif sock in txs:
sock.send(msg)
return True
else:
return False
host = 'localhost'
port = 9999
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((host, port))
s.listen(1)
print "waiting for client"
conn, addr = s.accept()
print "client connected"
conn.setblocking(0)
batchSize = 50
idle = 1.
count = 0
running = 1
while running:
try:
sc = 0
while (sc < batchSize):
if do_send (conn, 'Hello World ' + repr(count) + '\n', 1.0):
sc += 1
count += 1
print "sent " + repr(batchSize) + ", waiting " + repr(idle) + " seconds"
time.sleep(idle)
except socket.error:
conn.close()
running = 0
print "done"
Simple Spark code:
from pyspark import SparkContext
from pyspark.streaming import StreamingContext
sc = SparkContext("local[2]","test")
ssc = StreamingContext(sc, 1)
ststr = ssc.socketTextStream("localhost", 9999)
lines = ststr.flatMap(lambda line: line.split('\n'))
lines.pprint()
ssc.start()
ssc.awaitTermination()
Hope this may be useful.
I am currently doing a project for university, I have to create a multiple chat client and server in python 3.4.
For some reason it will connect to one client but when a second client tries to connect it does nothing. However when the first client disconnects the other client will connect to it. Does anyone have any ideas, I have been trying to work this out for over 3 hours.
The Client Server
import socket
def Main():
print("Send 'q' to exit\n")
address = str(input("ip:port -> "))
nick = input("nick: ")
try:
if address.index(":") != 0:
host = address[:address.index(":")]
port = int(address[address.index(":")+1:])
except ValueError:
host = address
port = 5000
s = socket.socket()
s.connect((host, port))
message = input("-> ")
while message != "q":
send_message = message + "pPp" + nick
send_message2 = send_message.encode("UTF-8")
s.send(bytes(send_message2))
data = s.recv(1024)
data_decoded = data.decode("UTF-8")
data2 = data_decoded
print(data_decoded)
messageServer = str(data_decoded[:data_decoded.index("pPp")])
nickServer = str(data_decoded[data_decoded.index("pPp")+3:])
if not data_decoded == data2:
print(nickServer + ": " + messageServer)
message = input("-> ")
s.close()
if __name__ == "__main__":
Main()
The server side:
import socket
import time
import os
from threading import Thread
folderPath = "Chat Logs"
filePath = folderPath + "/" + str(time.strftime("%H-%M-%S_%d-%m-%Y")) + ".txt"
def clientHandler(c):
while True:
data = c.recv(1024)
if not data:
break
data_decoded = data.decode("UTF-8")
message = str(data_decoded[:data_decoded.index("pPp")])
nick = str(data_decoded[data_decoded.index("pPp")+3:])
print(nick + "$" + message)
saveChat(nick, message)
print(" Sending: " + data_decoded)
c.send(bytes(data_decoded.encode("UTF-8")))
c.close()
def saveChat(nick, message):
if not os.path.exists(folderPath):
os.makedirs(folderPath)
if not os.path.exists(filePath):
f = open(filePath, "a")
f.close()
f = open(filePath, "a")
f.write(nick + ": " + message + "\n")
f.close()
def Main():
host = str(socket.gethostbyname(socket.gethostname()))
port = 5000
print(host + ":" + str(port) + "\n")
Clients = int(input("Clients: "))
s = socket.socket()
s.bind((host, port))
s.listen(Clients)
while True:
c, addr = s.accept()
print("Connection from: " + str(addr))
Thread(target=clientHandler(c)).start()
s.close()
if __name__ == "__main__":
Main()
You are initializing the Thread object correctly. Try one of these:
Thread(target=clientHandler, args=(c,)).start()
or
Thread(target=lambda c=c: clientHandler(c)).start()
Thread takes a callable as the target argument. Instead of passing in a callable, your code invokes the clientHandler, and passes its return value to Thread.__init__.
the changed code for server.py works for me.
what if we accept the connections in the thread handler and pass the socket object as an argument when we call the handler.
def clientHandler(s):
while True:
c, addr = s.accept()
print("Connection from: " + str(addr))
data = c.recv(1024)
if not data:
break
data_decoded = data.decode("UTF-8")
message = str(data_decoded[:data_decoded.index("pPp")])
nick = str(data_decoded[data_decoded.index("pPp")+3:])
print(nick + "$" + message)
#saveChat(nick, message)
print(" Sending: " + data_decoded)
c.send(bytes(data_decoded.encode("UTF-8")))
c.close()
In main function, I changed the following lines.
while True:
#c, addr = s.accept()
#print("Connection from: " + str(addr))
Thread(target=clientHandler(s)).start()
Here is the connection result:
>>>
10.212.245.81:5000
Clients: 3
Connection from: ('10.212.245.81', 60945)
c1$hi
Sending: hipPpc1
Connection from: ('10.212.245.81', 60976)
c2$hi
Sending: hipPpc2
Connection from: ('10.212.245.81', 61096)
c3$hi
Sending: hipPpc3
P.S I didn't try to check the code by exceeding the number of client connect requests.
Any help on how I can get this to accept more than one client, and why it isn't at the moment? Thanks!
Also, is there anything I'm doing wrong with this code? I've been following mostly Python 2 tutorials because I can't find any for Python 3.4
Here is my Server code:
import socket
import time
import os
from threading import Thread
folderPath = "Chat Logs"
filePath = folderPath + "/" + str(time.strftime("%H-%M-%S_%d-%m-%Y")) + ".txt"
def clientHandler(c):
while True:
data = c.recv(1024)
if not data:
break
data = data.decode("UTF-8")
message = str(data[:data.index("§")])
nick = str(data[data.index("§")+1:])
print(nick + ": " + message)
saveChat(nick, message)
print(" Sending: " + data)
c.send(bytes(data, "UTF-8"))
c.close()
def saveChat(nick, message):
if not os.path.exists(folderPath):
os.makedirs(folderPath)
if not os.path.exists(filePath):
f = open(filePath, "a")
f.close()
f = open(filePath, "a")
f.write(nick + ": " + message + "\n")
f.close()
def Main():
host = str(socket.gethostbyname(socket.gethostname()))
port = 5000
print(host + ":" + str(port) + "\n")
Clients = int(input("Clients: "))
s = socket.socket()
s.bind((host, port))
s.listen(Clients)
for i in range(Clients):
c, addr = s.accept()
print("Connection from: " + str(addr))
Thread(target=clientHandler(c)).start()
s.close()
if __name__ == "__main__":
Main()
And here is my Client code:
import socket
def Main():
print("Send 'q' to exit\n")
address = str(input("ip:port -> "))
nick = input("nick: ")
try:
if address.index(":") != 0:
host = address[:address.index(":")]
port = int(address[address.index(":")+1:])
except ValueError:
host = address
port = 5000
s = socket.socket()
s.connect((host, port))
message = input("-> ")
while message != "q":
s.send(bytes(message + "ยง" + nick, "UTF-8"))
data = s.recv(1024)
data = data.decode("UTF-8")
data2 = data
messageServer = str(data[:data.index("ยง")])
nickServer = str(data[data.index("ยง")+1:])
if not data == data2:
print(nickServer + ": " + messageServer)
message = input("-> ")
s.close()
if __name__ == "__main__":
Main()
First of all, I found these tutorials very helpful: BinaryTides
Here is an example of a simple tcp server that accepts multiple clients. All this one does receive data from the client and return "OK .. " + the_data. However, you could easily modify it to have a function that broadcasts the data(chat msg) to all clients connected. This example uses threading. You should google for the select module. With regards to your threads, are you sure you are a) using the right module/method for the job and b) that you are calling it in the right way?
import socket
import sys
from thread import start_new_thread
HOST = '' # all availabe interfaces
PORT = 9999 # arbitrary non privileged port
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
except socket.error, msg:
print("Could not create socket. Error Code: ", str(msg[0]), "Error: ", msg[1])
sys.exit(0)
print("[-] Socket Created")
# bind socket
try:
s.bind((HOST, PORT))
print("[-] Socket Bound to port " + str(PORT))
except socket.error, msg:
print("Bind Failed. Error Code: {} Error: {}".format(str(msg[0]), msg[1]))
sys.exit()
s.listen(10)
print("Listening...")
# The code below is what you're looking for ############
def client_thread(conn):
conn.send("Welcome to the Server. Type messages and press enter to send.\n")
while True:
data = conn.recv(1024)
if not data:
break
reply = "OK . . " + data
conn.sendall(reply)
conn.close()
while True:
# blocking call, waits to accept a connection
conn, addr = s.accept()
print("[-] Connected to " + addr[0] + ":" + str(addr[1]))
start_new_thread(client_thread, (conn,))
s.close()