def Post_Msg(cli): os.system('clear') tweet = raw_input('\tEnter your tweet: ') send_sock.sendall(ip_checksum('Post Tweet') + 'Post Tweet') send_sock.sendall(cli + ': ' + tweet) menu(cli) return
def Offline_Msg(cli): os.system('clear') has_answered = False while not has_answered: send_sock.sendall(ip_checksum("Offline_messages_request") + 'Offline_messages_request') try: message = send_sock.recv(4096) except timeout: print '\tTimeout - Sever busy' continue else: has_answered = True ret = json.loads(message) MsgList = ret["msglist"] print '\n\t********************' print '\n\t' + cli + ' List of Messages:' print '\n\t' if MsgList == 'No Messages Received': print MsgList else: for i in range(0, len(MsgList)): print MsgList[i] print '\n' menu(cli) return
def checksum_valid(chk, seq, header, data): checksum = pack('IH' + str(len(data)) + 's', seq, header, data) if ip_checksum(checksum) == chk: return True else: return False
def read_choice(cli): print '\n\t****************************' choice = int(raw_input('\n\tPick a menu option: ')) print '\n\t****************************' if choice == 1: Offline_Msg(cli) elif choice == 2: Edit_Sub(cli) elif choice == 3: Post_Msg(cli) elif choice == 4: print '\n\t***GoodBye***\n\tLogging You Out' has_received = False while not has_received: send_sock.sendall(ip_checksum('Logging Out') + 'Logging Out') reply = send_sock.recv(4096) if reply == 'success': has_received = True send_sock.close() elif choice == 5: Hashtag_Search(cli) elif choice == 6: See_followers(cli) elif choice == 7: Send_Msgs(cli) elif choice == 8: Del_Friend_Msgs(cli) elif choice == 9: Del_All_Msgs(cli)
def checksum_valid(chk, seq, header, data): checksum = pack('IH'+str(len(data))+'s', seq, header, data) if ip_checksum(checksum) == chk: return True else: return False
def chkpckt(pckt): pckt_seq = pckt[0:1] pckt_chksum = pckt[1:3] pckt_msg = pckt[3:] if pckt_chksum == ip_checksum(pckt_msg): return (True, pckt_seq, pckt_msg) else: return (False, pckt_seq, pckt_msg)
def mkpkt(seqNum, data): global isCorrupt chksum = ip_checksum(str(data)) if isCorrupt == 1 and data == 1: isCorrupt = 0 chksum = 'corrupted' pkt = str(seqNum) + str(data) + chksum return pkt
def login_verification(): msg_count = 0 while True: connection, address = recv_sock.accept() message = connection.recv(4096) checksum = message[:2] if not ip_checksum(message[2:]) == message[:2]: continue else: s = message[2:] temp = [] temp = s.split(':') if len(temp) == 2: name, password = temp[0], temp[1] found = False for cli in cli_list: if cli == [name, password]: found = True break if not found: connection.sendall(ip_checksum('Invalid') + 'Invalid') print '\n\t' + name + ' Connection attempt failed\n' else: print '\n\t' + name + ' Successfully Logged in\n' connection.sendall(ip_checksum('Valid') + 'Valid') connections[user_id(name)].append(connection) recv_sock.listen(1) live_sock, address = recv_sock.accept() connections[user_id(name)].append(live_sock) print len(connections[user_id(name)]) print '\t' + name + ' Live socket connected' #recv_sock.listen(5) t = threading.Thread(target = user_handler, args=(name, connection,)) t.daemon = True threads.append(t) t.start() recv_sock.close()
def Del_All_Msgs(cli): os.system('clear') send_sock.sendall(ip_checksum('Del_All_Msgs') + 'Del_All_Msgs') has_succeeded = False while not has_succeeded: reply = send_sock.recv(4096) if reply == 'success': has_succeeded = True menu(cli) return
def makepkt(num, data): global iscorrupt if iscorrupt == 1 and data == 1: iscorrupt = 0 checksum = 'corrupted' else: checksum = ip_checksum(str(data)) packet = str(num) + str(data) + checksum return packet
def makepkt(num, data): global iscorrupt if iscorrupt == 1 and data == 2: iscorrupt = 0 checksum = 'corrupted' print "packet " + str(data) + "is corrupted, sending " else: checksum = ip_checksum(str(data)) packet = str(num) + str(data) + checksum return packet
def make_packet(seq_num, message): """ Creates a packet using the sequence number and data provided. Calculates checksum of data add concatenates it with data. Returns a single string containing sequence number, data, and checksum, in that order. """ tmp = str(seq_num) + message checksum = ip_checksum(tmp) final_packet = tmp + checksum return final_packet
def sendwithcheck(sock, msg, to): checksum = ip_checksum(msg) tosend = checksum+msg rand = random.randint(1, 20) if rand >= 1 and rand <= 5: print("Dropped") return rand_sleep() sock.sendto(tosend, to)
def sendwithcheck(sock, msg, to): checksum = ip_checksum(msg) tosend = checksum + msg rand = random.randint(1, 20) if rand >= 1 and rand <= 5: print("Dropped") return rand_sleep() sock.sendto(tosend, to)
def authenticate(): os.system('clear') print '\t***************************' cli_name = raw_input('\tUsername: '******'\tPassword: '******'\t***************************' print '\n\t****Waiting for server to authenticate your login****\n' authentication = cli_name authentication += ':' + cli_pwd ans_received = False while not ans_received: send_sock.sendall(ip_checksum(authentication) + authentication) try: message = send_sock.recv(4096) except timeout: print 'Timeout occured -- Server Busy' continue else: if not message[:2] == ip_checksum(message[2:]): continue #resend the authentication to server else: ans_received = True if message[2:] == 'Valid': os.system('clear') print '\n\tSuccessful Login!! -- Welcome ' + cli_name live_sock = socket(AF_INET, SOCK_STREAM) live_sock.connect(dest) t = threading.Thread(target = tweets_and_msgs_handler, args=(cli_name, live_sock, )) t.daemon = True t.start() menu(cli_name) elif message[2:] == 'Invalid': print '\n\tError: Name or Password entered is invalid -- Try again' authenticate() send_sock.close()
def corrupt(packet): """ Checks if packet was corrupted during transmission. Calculates checksum and compares it to the one included in the packet. Returns true if data is corrupted, false otherwise. """ data = packet[:len(packet) - 2] checksum = packet[len(packet) - 2:] calculated_check = ip_checksum(data) if checksum != calculated_check: return True return False
def tick(self): # Progress all games for game in self.db.ongoing_games: if game.ongoing : game.tick() else : self.db.ongoing_games.remove(game) #Receive data from client. readable, writable, exceptional = select.select([self.s], [], [], 0); d = None self.data = "" self.reply = "" if readable: d = self.s.recvfrom(1024) data = d[0] self.addr = d[1] self.source = str(d[1]) # print 'Handled player request' elif not self.data_q.empty(): d = self.data_q.get(False) # print 'Host packet contents : ' + d self.route_msg(d) return else: return # Take apart packet self.ack = data[4] msg = data[5:-2] chksum = data[-2:] ''' print 'OK... \n' + \ 'Source Port : ' + self.source + '\n' \ 'Ack : ' + self.ack + '\n' + \ 'Data : ' + msg + '\n'# + \ # 'Checksum : [' + chksum + ']'; ''' # print 'This checksum : [' + ip_checksum(msg) + ']' if ip_checksum(msg) == chksum: # Not corrupt # print 'Routing message to correct control code.' self.route_msg(msg) self.ack = '0' if (self.ack == '0') else '1' else: self.ack = '1' if (self.ack == '1') else '0' #print 'Denying packet for 7.5 seconds...' #time.sleep(7.5); reply = 'ACK' + self.ack + '\n' + str(self.data); # print 'Sending reply : ' + reply self.s.sendto(reply, (self.addr[0], self.addr[1]));
def Edit_Sub(cli): os.system('clear') print("""\n \t1. Add Subscription \t2. Delete Subscription """) choice = int(raw_input('\n\tEnter Your Choice: ')) if choice == 1: send_sock.sendall(ip_checksum('Subscribe') + 'Subscribe') friend = raw_input('\n\tEnter Friend to Subscribe to: ') has_succeeded = False while not has_succeeded: send_sock.sendall(cli+friend) reply = send_sock.recv(4096) if reply == 'success': has_succeeded = True elif choice == 2: send_sock.sendall(ip_checksum('Unsubscribe') + 'Unsubscribe') reply = send_sock.recv(4096) list = json.loads(reply) sublist = list["list"] if sublist == 'No followers': print '\tNo user to Unsubscribe from' else: for l in sublist: print l friend = raw_input('\n\tEnter Friend to Unsubcribe from: ') has_succeeded = False while not has_succeeded: send_sock.sendall(cli+friend) reply = send_sock.recv(4096) if reply == 'success': has_succeeded = True menu(cli) return
def Del_Friend_Msgs(cli): os.system('clear') send_sock.sendall(ip_checksum('Del_Friend_Msgs') + 'Del_Friend_Msgs') friend = raw_input("\tEnter friend whose messages to delete: ") has_succeeded = False while not has_succeeded: send_sock.sendall(cli + ':' + friend) reply = send_sock.recv(4096) if reply == 'success': has_succeeded = True menu(cli) return
def See_followers(cli): os.system('clear') send_sock.sendall(ip_checksum('See Followers') + 'See Followers') reply = send_sock.recv(4096) msg = json.loads(reply) subList = msg["subList"] print '\n\t' + cli + ' List of Followers: ' if subList == 'No Followers': print subList else: for i in range(0, len(subList)): print subList[i] print '\n' menu(cli) return
def Hashtag_Search(cli): os.system('clear') send_sock.sendall(ip_checksum('Hashtag Search') + 'Hashtag Search') hashtag = raw_input('\tEnter the hashtag to search for: ') send_sock.sendall(hashtag) reply = send_sock.recv(4096) msg = json.loads(reply) hashList = msg["hashList"] print '\n\t' + cli + ' List of tweets containing ' + hashtag + ':' if hashList == 'No Tweets Found': print hashList else: for i in range(0, len(hashList)): print hashList[i] print '\n' menu(cli) return
def Send_Msgs(cli): os.system('clear') send_sock.sendall(ip_checksum('Send Message') + 'Send Message') destinator = raw_input('\n\tEnter destinator: ') msg = raw_input('\tEnter Message: ') while len(msg) > 140: print '\n\tMessage longer than 140 characters -- try again' msg = raw_input('\tEnter Message: ') has_succeeded = False while not has_succeeded: send_sock.sendall(destinator + cli + ': ' + msg) reply = send_sock.recv(4096) if reply == 'success': has_succeeded = True menu(cli) return
def checksum_cmp (received_content, received_checksum): #casting checksum to str by itself is not the same when casting it to str via tuple... #when checksum is in tuple and is cast into a string, they are the same check = ip_checksum(received_content) tuple_pkt = (0,0, check) tuple_pkt_str = str(tuple_pkt) splice_tuple_pkt = string.split(tuple_pkt_str, ',') j = 0 for i in splice_tuple_pkt: i = string.strip(i, '(') i = string.strip(i, ')') i = string.strip (i) #by default it removes whitespace i = string.strip (i, '\'') splice_tuple_pkt[j] = i j = j + 1 if splice_tuple_pkt[2] == received_checksum: return 1 else: return 0
print('Socket bind complete') expecting_seq = 0 #now keep talking with the client while 1: # receive data from client (data, addr) msg, addr = s.recvfrom(1024) #msg = msg.decode('utf-8') checksum = msg[:2] seq = msg[2] cont = msg[3:] if not msg: break if ip_checksum(cont) == checksum: sendwithcheck(s, "ACK" + seq, addr) if seq == str(expecting_seq): print('Message[' + addr[0] + ':' + str(addr[1]) + '] - ' + cont) expecting_seq = 1 - expecting_seq #reply = 'OK...' + data #s.sendto(reply.encode('utf-8') , addr) else: neg_seq = str(1 - expecting_seq) sendwithcheck(s, "ACK" + neg_seq, addr) s.close()
# use it in this way #https://www.bogotobogo.com/python/Multithread/python_multithreading_subclassing_Timer_Object.php # create dgram udp socket try: s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) except socket.error: print 'Failed to create socket' sys.exit() host = 'localhost' port = 8888 seqnum = 0 # sequence number msg = raw_input('Enter message to send : ') chks = str(ip_checksum(msg)) #convert checksum return value to string data = (str(seqnum) + chks + msg) s.sendto(data, (host, port)) while (1): msg = raw_input('Enter message to send : ') #chks = str(ip_checksum(msg)) #convert checksum return value to string #data = (str(seqnum) + chks + msg) #all 3 values are strings and merged together try: # Set the whole string # s.sendto(msg, (host, port)) # s.sendto(data, (host, port)) # receive data from client (data, addr) d = s.recvfrom(1024)
PKT = 1 #packet number N = 4 #window size TIMEOUT = 10 #timeout time try: s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) except socket.error: print 'Failed to create socket' sys.exit() while 1: msg = raw_input('Enter message to send : ') # msg = msgList[count] # old_msg = msg # count+=1 checksum = ip_checksum(msg) #get checksum of message # if msg[0:1] == 'C' and flag==0: # checksum = checksum + "c" # flag = 1 msg = str(PKT).zfill(3) + str( checksum) + msg #new message: 00PKT+CHKSM+MSG pkt_curr = pkt_struct(PKT, msg) #set current: packet with packet number and msg pkt_list.append(pkt_curr) PKT += 1 #increment packet number try: #try to send packet if (pkt_curr.num < BASE + N): pkt_curr.send_pkt(s) #s.sendto(pkt_curr.msg, (HOST, PORT)) #pkt_curr.time_sent = time.time() inputs = [s]
old_msg = '' resend = 0 count = 1 while(1) : try : while(1) : if nextseqnum >= base + windowSize : break if nextseqnum > 9 : break msg = str(msgList[nextseqnum]) s.settimeout(3) d = ip_checksum(msg) msg_d = d + msg msg_seq_d = str(nextseqnum) + msg_d # check corrupted msg # msg_d = 'll' + msg if nextseqnum < base + windowSize : print 'sending... ' + msg_seq_d s.sendto(msg_seq_d, (host, port)) nextseqnum = nextseqnum + 1 else : break # receive data from client (data, addr) try: data = s.recvfrom(1024)
#receive data from client(data,addr) d=s.recvfrom(1024) data=d[0] addr=d[1] rc_seqnum=data[0] get_checksum=data[1:3] rc_msg=data[3:] print 'Message['+addr[0]+':'+str(addr[1])+']-'+rc_msg if ( rc_msg==''): status=0 continue reply_msg='OK...' +rc_msg if ( rc_seqnum==str(expectedseqnum) and get_checksum==ip_checksum(rc_msg) ): expectedseqnum=(expectedseqnum+1)%10 snd_seqnum=str(expectedseqnum) snd_checksum=ip_checksum(reply_msg) reply=rc_seqnum+snd_seqnum+snd_checksum+reply_msg s.sendto(reply,addr) print 'expected number is '+str(expectedseqnum) else: snd_seqnum=str(expectedseqnum) snd_checksum=ip_checksum('') if expectedseqnum==0: ACK=9 else: ACK=expectedseqnum-1 reply=str(ACK)+snd_seqnum+snd_checksum+'' s.sendto(reply,addr)
signal.signal(signal.SIGALRM, timer_for_ack) signal.setitimer(signal.ITIMER_REAL, 0.01, 0.01) winhead = 0 while not sendOver: wincur = wintail + 1 if wincur >= winSize and winhead != wincur and wincur%winSize == winhead%winSize: continue data = msg_to_send() header = int('1111111100000000', 2) cs = pack('IH' + str(len(data)) + 's', seqno, header, data) checksum = ip_checksum(cs) packet = pack('I2sH' + str(len(data)) + 's', seqno, checksum, header, data) if wincur < winSize: winPkts.append(packet) tickers.append(TIMEOUT) else: winPkts[wincur % winSize] = packet tickers[wincur % winSize] = TIMEOUT print "Sending P" + str(seqno) + ", timer started" if CORRUPT > random.random(): error_data = "01234567012345678012345678012345678" packet = pack('I2sH' + str(len(error_data)) + 's', seqno, checksum, header, error_data)
print('Socket bind complete') expecting_seq = 0 #now keep talking with the client while 1: # receive data from client (data, addr) msg, addr = s.recvfrom(1024) #msg = msg.decode('utf-8') checksum = msg[:2] seq = msg[2] cont = msg[3:] if not msg: break if ip_checksum(cont) == checksum: sendwithcheck(s, "ACK" + seq, addr) if seq == str(expecting_seq): print('Message[' + addr[0] + ':' + str(addr[1]) + '] - ' + cont) expecting_seq = 1 - expecting_seq #reply = 'OK...' + data #s.sendto(reply.encode('utf-8') , addr) else: neg_seq = str(1 - expecting_seq) sendwithcheck(s, "ACK" + neg_seq, addr) s.close()
inputs=[s] outputs=[] timeout=10 while(1): input_msg=raw_input('Enter message to send : ') try : status='a' length=2 while(len(input_msg)>0): #Set the whole string snd_msg=input_msg[0:length] print 'Send message : '+snd_msg d=ip_checksum(snd_msg) snd_status=status send_msg=snd_status+d+snd_msg s.sendto(send_msg,(host,port)) readable,writable,exceptional=select.select(inputs,outputs,inputs,timeout) for s in readable: #receive data from client (data, addr) d=s.recvfrom(1024) reply=d[0] addr=d[1] rc_status=reply[0] get_checksum=reply[1:3] reply_msg=reply[3:] print 'Server reply : '+reply_msg
def makeack(s, seq, msg): ack = seq + ip_checksum(msg) + msg return ack
s.bind(("", PORT)) except socket.error, msg : print 'Bind failed. Error Code: ' + str(msg[0]) + ' Message ' + msg[1] sys.exit() print 'Socket bind complete' while 1: d = s.recvfrom(1024) data = d[0] addr = d[1] if not data: break if data[1:3] != ip_checksum(data[3:]): continue ACK = data[0] reply = str(ACK) + data[3:] s.sendto(reply, addr) if ACK != str(PKT): print 'DUPLICATE' else: PKT = 0 if PKT else 1 print 'Message[' + addr[0] + ':' + str(addr[1]) + '] - ' + data.strip() #COUNT += 1 #if COUNT % 3 == 0: # sleep(5)
outputs=[] timeout=10 cwnd=4 base=0 nextseqnum=0 while(1): input_msg=raw_input('Enter message to send : ') try : length=2 begin=0 end=2 while(len(input_msg[0:]) <base or len(input_msg[begin:])>0 ): while(len(input_msg[begin:])>0 and nextseqnum<base+cwnd): snd_msg=input_msg[begin:end] d=ip_checksum(snd_msg) snd_seqnum=str(nextseqnum % 10) send_msg=snd_seqnum+d+snd_msg s.sendto(send_msg,(host,port)) print 'Send message : '+snd_msg+', sndseqnum :' +snd_seqnum nextseqnum=nextseqnum+1 print 'nextseqnum is '+str(nextseqnum)+', base+cwnd is '+str(base+cwnd) sleep(1) begin=nextseqnum*length if(len(input_msg[nextseqnum*length:])<length): end=begin+len(input_msg[nextseqnum*length:]) else: end=(nextseqnum+1)*length
print 'Socket bind complete' inputs = [s] outputs = [] #ackstatus to return the package 0/1 if received currAck = 0 testCase = 0 #now keep talking with the client while 1: d = s.recvfrom(1024) data = d[0] addr = d[1] #set the checksum from from the data recieved checksum = ip_checksum(data[1:-2]) if not data: break #Wrong ACK if (data[0] != str(currAck)): print 'Duplicate Packet' continue #Corrupted checksum if (data != (str(currAck) + data[1:-2] + checksum)) and ( data != (str(not ACKstatus) + data[1:-2] + checkSum)): print 'Corrupt' continue #check the test, set a timeout if testCase == 1:
PKT = 1 #packet number N = 4 #window size TIMEOUT = 10 #timeout time try: s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) except socket.error: print 'Failed to create socket' sys.exit() while 1: msg = raw_input('Enter message to send : jk hardcoded so it doesnt matter ') msg = msgList[count] old_msg = msg count+=1 checksum = ip_checksum(msg) #get checksum of message if msg[0:1] == 'C' and flag==0: checksum = checksum + "X" flag = 1 msg = str(PKT).zfill(3) + str(checksum) + msg #new message: 00PKT+CHKSM+MSG pkt_curr = pkt_struct(PKT, msg) #set current: packet with packet number and msg pkt_list.append(pkt_curr) PKT += 1 #increment packet number try: #try to send packet if (pkt_curr.num < BASE + N): pkt_curr.send_pkt(s) #s.sendto(msg, (HOST, PORT)) #gotta send the corrupted msg (not original) #pkt_curr.time_sent = time.time() inputs = [s] outputs = []
while 1: msg = raw_input("Press anykey to send packets") try: reset() for i in range(2): if base == nextseqnum: timerStart(base, windowsize) while 1: d = s.recvfrom(1024) reply = d[0] ACK = int(reply[0]) ACKCheckSum = reply[1:] CheckSum = ip_checksum(str(ACK)) if ACKCheckSum == CheckSum: base = ACK + 1 if base == nextseqnum: timer.cancel() break else: timer.cancel() timer = threading.Timer(2, timerStart, [base, windowsize]) timer.start() except socket.error, msg: print 'Error code: ' + str(msg[0]) + 'Message ' + msg[1] sys.exit()
inputs = [s] #socket outputs = [] timeout = 0 #when timeout is 0, it basically polls readable, writeable, expectional = select.select(inputs, outputs, inputs, timeout) for temp_socket in readable: received_data = temp_socket.recvfrom(1024) received_packet = received_data[0] address = received_data[1] print 'Received packet: ', received_packet packet_sequence_number, packet_data, packet_checksum = extract_data(received_packet) #print packet_sequence_number, packet_data, packet_checksum #check if packet has sequence number 1 or 0 #if 1 then we send an ACK1 back because there was a packet loss and #the sender requires this ACK to make progress. Otherwise, the sender is 'stuck' if packet_sequence_number == '1': checksum = ip_checksum ('ACK1') packet_to_send = make_packet ('1', 'ACK1', checksum) #send packet s.sendto(str(packet_to_send), address) elif packet_sequence_number == '0' and checksum_cmp(packet_data, packet_checksum): # we have already extracted the data ''' This is were we would forward the data up the internet protocl stack to the application layer or any intermediate agent between the transport and application layer. ''' #send ACK0 to sender checksum = ip_checksum ('ACK0') packet_to_send = make_packet('0', 'ACK0', checksum) #send packet s.sendto(str(packet_to_send), address)
#initialize thread list of size 4 threadList = [None] * windowSize #initialize ack list of size 8 ackList = [error] * maxSeqNum for i in range(base, base + windowSize): timerStart(nextSeqNum, threadList, i) nextSeqNum = nextSeqNum + 1 while 1: d = s.recvfrom(1024) reply = d[0] ackNum = int(reply[0]) ackChksum = reply[1:] chksum = ip_checksum(str(ackNum)) #check if ACK is corrupt if ackChksum == chksum: ackList[ackNum] = ackNum #ACK received correctly so cancel timer index = ackNum % 4 threadList[index].cancel() print 'ACK ' + str(ackNum) + ' received' if base == maxSeqNum - 1: break #check if next packet sent is in sender window #base + windowSize is packet number
s.bind(("", PORT)) except socket.error, msg : print 'Bind failed. Error Code: ' + str(msg[0]) + ' Message ' + msg[1] sys.exit() print 'Socket bind complete' while 1: d = s.recvfrom(1024) data = d[0] addr = d[1] if not data: break if data[3:5] != ip_checksum(data[5:]): continue RCVPKT = int(data[0:3]) ACK = RCVPKT #if not the packet we are waiting for re-ack previous packet if RCVPKT != PKT: #not the right packet, send ACK of older packet ACK = PKT - 1 #resend the previous PKT print 'UNEXPECTED RCVPKT' #packet we are waiting for, send next pkt else: PKT += 1 reply = str(ACK).zfill(3) + data[3:] s.sendto(reply, addr) print 'Message[' + addr[0] + ':' + str(addr[1]) + '] - ' + data.strip()
while 1: msg = raw_input('press enter to send') try: reset() thelist = [None] * 10000 acklist = [NACK] * maxseqnum for i in range(base, base + windowsize): timerStart(nextseqnum, thelist, i) nextseqnum = nextseqnum + 1 while 1: d = s.recvfrom(1024) reply = d[0] Num = int(reply[0]) check = (reply[1:]) CheckSum = ip_checksum(str(Num)) print 'received ack' + str(Num) if CheckSum == check: acklist[Num] = Num index = Num thelist[index].cancel() if base == maxseqnum - 1: break if base == Num and nextseqnum < maxseqnum: index = nextseqnum timerStart(nextseqnum, thelist, index) nextseqnum = nextseqnum + 1 base = getbase(acklist, base, windowsize) else:
old_msg = '' resend = 0 count =0 while(1) : if base == 10 : break elif nextseqnum < base + windowSize : msg = str(pktList[nextseqnum]) try : s.settimeout(3) if msg == '2' : if count == 0: d = ip_checksum(msg+'1') msg_d = d + msg msg_seq_d = str(nextseqnum) + msg_d count = count + 1 else: d = ip_checksum(msg) msg_d = d + msg msg_seq_d = str(nextseqnum) + msg_d else : d = ip_checksum(msg) msg_d = d + msg msg_seq_d = str(nextseqnum) + msg_d if nextseqnum < base + windowSize : print 'sending... PKT' + msg_seq_d[3:] s.sendto(msg_seq_d, (host, port))
def makepckt(msg): global seq_num pckt = seq_num + ip_checksum(msg) + msg return pckt
#now keep talking with the client while 1: inputs = [s] outputs = [] timeout = 5 readable,writable,exceptional = select.select(inputs,outputs,inputs,timeout) for tempSocket in readable: temp = tempSocket.recvfrom(1024) reply = temp[0] addr = temp[1] ack = reply[0:1] msg_sum = reply[1:2] msg = reply[3:len(reply)] msg_chksum = ip_checksum(msg) if msg_sum == msg_chksum: message = 'received ack ' + reply[0:1] s.sendto(message, (HOST, PORT)) else : print 'packet corrupted' #s.sendto(reply , addr) s.close()
# print "Resending msg " + str(msg0[0]) + ": " + str(msg0[1:-2]) # print "Resending msg " + str(msg1[0]) + ": " + str(msg1[1:-2]) # print "Resending msg " + str(msg2[0]) + ": " + str(msg2[1:-2]) # print "Resending msg " + str(msg3[0]) + ": " + str(msg3[1:-2]) # x = threading.Thread(target = recv_thread, args=(base,)) # x.start() # x.join(TIMEOUT) # index = index + 4 # nextseqnum = index % (N * 2 + 1) # base = base +1 msg = str(nextseqnum) + messages[index] + str( ip_checksum(messages[index])) s.sendto(msg, (host, port)) print "Sending msg " + str(msg[0]) + ": " + str(msg[1:-2]) x = threading.Thread(target=recv_thread, args=(base, )) x.start() x.join(TIMEOUT) while x.isAlive(): for r in range(base, base + 3): msg = str(r % (N * 2 + 1)) + messages[r] + str( ip_checksum(messages[r])) s.sendto(msg, (host, port)) print "Sending msg " + str(msg[0]) + ": " + str(msg[1:-2]) x = threading.Thread(target=recv_thread, args=(base, ))
def user_handler(name, connection): user = user_id(name) send_offline_tweets(name) while True: #connection, address = recv_sock.accept() message = connection.recv(4096) print '\tclient request: ' + name + ' ' + message[2:] if not message: break elif message[:2] == ip_checksum(message[2:]): if message[2:] == 'Offline_messages_request': user = user_id(name) if len(MsgList[user]) == 0: msg = json.dumps({"msglist" :'No Messages Received'}) else: msg = json.dumps({"msglist" :MsgList[user]}) connection.sendall(msg) elif message[2:] == 'Send Message': message = connection.recv(4096) hdr = message[:2] if len(connections[user_id(hdr)]) == 0: MsgList[user_id(hdr)].append(message[2:]) else: connections[user_id(hdr)][1].sendall('live_msg' + message[2:]) connection.sendall('success') elif message[2:] == 'Post Tweet': tweet = connection.recv(4096) tweetList.append(tweet) for j in range(0, len(connections)): st = 'c' + str(j) if st in subList[user_id(name)]: if len(connections[j]) == 0: off_list_tweets[j].append(tweet) else: connections[j][1].sendall('live_twt'+tweet) elif message[2:] == 'Del_Friend_Msgs': message = connection.recv(4096) temp = [] temp = message.split(':') user = temp[0] friend = temp[1] a = user_id(name) lst = MsgList[a] for l in lst: if l[:2] == friend: MsgList[a].remove(l) connection.sendall('success') elif message[2:] == 'Del_All_Msgs': a = user_id(name) lst = MsgList[a] for l in lst: MsgList[a].remove(l) connection.sendall('success') elif message[2:] == 'Subscribe': msg = connection.recv(4096) friend = msg[2:] me = msg[:2] subList[user_id(friend)].append(me) connection.sendall('success') elif message[2:] == 'Unsubscribe': unsub = [] for i in range(0, len(subList)): if name in subList[i]: unsub.append('c'+str(i)) if len(unsub) == 0: msg = json.dumps({"list" : 'No followers'}) connection.sendall(msg) else: msg = json.dumps({"list" : unsub}) connection.sendall(msg) msg = connection.recv(4096) friend = msg[2:] me = msg[:2] subList[user_id(friend)].remove(me) connection.sendall('success') elif message[2:] == 'See Followers': if len(subList[user_id(name)]) == 0: msg = json.dumps({"subList" : 'No Followers'}) else: msg = json.dumps({"subList" : subList[user_id(name)]}) connection.sendall(msg) elif message[2:] == 'Hashtag Search': msg = connection.recv(4096) hashList = [] for i in range(0, len(tweetList)): if msg in tweetList[i]: hashList.append(tweetList[i]) if len(hashList) == 0: msg = json.dumps({"hashList" : 'No Tweets Found'}) else: msg = json.dumps({"hashList" : hashList}) connection.sendall(msg) elif message[2:] == 'Logging Out': connection.sendall('success') connection.close() for c in connections[user_id(name)]: connections[user_id(name)].remove(c) return return
def udt_send(self, flag): checksum = ip_checksum(self.data) sndpkt = self.make_pkt(flag, checksum) self.s.sendto(sndpkt, (self.host, self.destport))
print('Resending timed-out packet ' + str(n) + '\n') s.sendto(msg, (host, port)) timer = threading.Timer(3.0, pkt_timer) # Create dgram udp socket # Client is sender # Packet # counter n = 0 # Set up initial packet # Scenario 1: Packets 0-2 print('\nSending 3 packets normally:\n') msg = 'packet ' + str(n) check_sum = ip_checksum(msg) msg += ';' + str(ord(check_sum[0]) + ord(check_sum[1])) s.sendto(msg, (host, port)) while(n < 9): # msg = raw_input('Enter message to send: ') # print('check_sum ' + str(ord(check_sum[0])) + '; pt 2: ' + str(ord(check_sum[1]))) try: if n == 6: timer.start() # Receive data from client (data, addr) d = s.recvfrom(1024) reply = d[0] addr = d[1]
timeout_test = True # now keep talking with the client while 1: # receive data from client (data, addr) data, addr = s.recvfrom(1024) checksum = data[:2] seq = data[2] pkt = data[3:] if not data: break # print(str(ip_checksum(pkt) == checksum)) if ip_checksum(pkt) == checksum and seq == str(expect_seq): print('recv: Good Data Sending ACK' + str(seq)) print('recv pkt: ' + str(pkt)) # Test timeout on message 4 if str(pkt) == 'Message 4': time.sleep(5) s.sendto(str(seq), addr) expect_seq = 1 - expect_seq else: # Check seq and send according ACK if seq == str(expect_seq): print('recv: Bad Checksum Not Sending') else: print('recv: Bad Seq Sending ACK' + str(1 - expect_seq)) s.sendto(str(1 - expect_seq), addr) s.close()
print "Failed to create client socket" sys.exit() host = 'localhost' port = 8888 i = 0 s.settimeout(2) while(1): flag2 = True flag = True msg = raw_input('Enter message to send: ') ackNum = 999 while flag2: try : d = ip_checksum(msg) if i % 2 == 0: ackNum = 0 if flag: tmp = str(ackNum) + "," + str(msg) + "," + "-1" else: tmp = str(ackNum) + "," + str(msg) + "," + d elif i % 2 == 1: ackNum = 1 if flag: tmp = str(ackNum) + "," + str(msg) + "," + "-1" else: tmp = str(ackNum) + "," + str(msg) + "," + d sendMessage(tmp, host, port, s)
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) print "Socket created" except socket.error: print "Failed to create client socket" sys.exit() try: s.bind((HOST, PORT)) print "Bind socket Created" except socket.error, msg: print "Failed to bind" sys.exit() #temp variable to save the last ack sent tmpAck = -1 while 1: d = s.recvfrom(1024) data = d[0] addr = d[1] x = data.split(",") if x[2] != ip_checksum(x[1]): print "Packet was lost" reply = str(tmpAck) else: if x[0] == "0" or x[0] == "1": reply = str(x[0]) tmpAck = x[0] s.sendto(reply, addr)
break # Split input into data and checksum #print('data = ' + str(data)) data = data.split(';', 1) #print('data[1] = ' + data[1]) checksum_exp = int(data[1]) data = data[0] print('Message[' + addr[0] + ':' + str(addr[1]) + '] - ' + data.strip()) #print('checksum_exp = ' + str(checksum_exp)) #print('checksum_exp type = ' + str(type(checksum_exp))) #print('data = ' + data) checksum_actual = ip_checksum(data) checksum_actual = ord(checksum_actual[0]) + ord(checksum_actual[1]) #print('checksum_actual = ' + str(checksum_actual)) #print('checksum_actual type = ' + str(type(checksum_actual))) if not corrupted_sent and data == 'packet 4': checksum_actual += 1 corrupted_sent = True if checksum_exp != checksum_actual: reply = 'CORRUPTED: ' + data print(reply) print('\tchecksum_exp = ' + str(checksum_exp)) print('\tchecksum_actual = ' + str(checksum_actual)) else:
sys.exit() # Bind socket to local host and port try: s.bind((HOST, PORT)) except socket.error, msg: print 'Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1] sys.exit() print 'Socket bind complete' # Variables ExpectedSeqNum = 0 N = 4 msg = "ACK" + str(ExpectedSeqNum) check = ip_checksum(msg) packet = str(ExpectedSeqNum) + str(len(msg)) + msg + check rcvpkts = [] base = 0 #now keep talking with the client while 1: # receive data from client (data, addr) d = s.recvfrom(1024) packet = d[0] SeqNum = int(packet[0]) datalength = int(packet[1]) data = packet[2:datalength + 2] check = packet[datalength + 2:] addr = d[1]
print 'Failed to create socket. Error Code : ' + str( msg[0]) + ' Message ' + msg[1] sys.exit() # Bind socket to local host and port try: s.bind((HOST, PORT)) except socket.error, msg: print 'Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1] sys.exit() print 'Socket bind complete' ExpectedSeqNum = 0 msg = "ACK" + str(ExpectedSeqNum) check = ip_checksum(msg) packet = str(ExpectedSeqNum) + str(len(msg)) + msg + check #now keep talking with the client while 1: # receive data from client (data, addr) d = s.recvfrom(1024) packet = d[0] SeqNum = int(packet[0]) datalength = int(packet[1]) data = packet[2:datalength + 2] check = packet[datalength + 2:] addr = d[1] if not data: break
print 'Timed Out: Retry sending Packet' + str(SeqNum) msg = 'Hello ' + str(SeqNum) check = ip_checksum(msg) packet = str(SeqNum) + str(len(msg)) + msg + check s.sendto(packet, (host, port)) Corrupt = raw_input("Do you want there to be a corrupt packet?(Y or N)") while (1): progress = raw_input("Press Enter to send more packets") for i in range(0, j): t = threading.Timer(2.0, Timeout) msg = 'Hello ' + str(SeqNum) if i == 1 and Corrupt == 'Y': check = str(1) + ip_checksum(msg) else: check = ip_checksum(msg) packet = str(SeqNum) + str(len(msg)) + msg + check try: #Send the whole string t.start() s.sendto(packet, (host, port)) d = s.recvfrom(1024) packet = d[0] AckNum = int(packet[0]) replylength = int(packet[1]) reply = packet[2:replylength + 2] check = packet[replylength + 2:] addr = d[1]
print 'Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1] sys.exit() print 'Socket bind complete' seq_num = '100' # bogus initial value while 1: d = s.recvfrom(1024) data = d[0] addr = d[1] if not data: break prev_sn = seq_num seq_num = data[0] if data[-2:] != ip_checksum(data[1:-2]): print 'Packet corrupted' else: reply = 'ACK' + str(seq_num) # Add for scenario 3: time.sleep(8) s.sendto(reply, addr) if seq_num != prev_sn: print 'Message[' + addr[0] + ':' + str( addr[1]) + '] - ' + data.strip()[1:-2] else: print 'Duplicate detected' s.close()
def Timeout(): print 'Timed Out: Retry sending Packet' + str(SeqNum) msg = 'Hello ' + str(SeqNum) check = ip_checksum(msg) packet = str(SeqNum) + str(len(msg)) + msg + check s.sendto(packet, (host, port))
print 'Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1] sys.exit() print 'Socket bind complete' #states for GBN receiver states = ['wait'] states_list = list(enumerate(states)) current_state = states_list[0] delay_ack1 = 0 #packet1_corrput = 0 expected_seq_num = 0 msg = 'ACK' + str (expected_seq_num) checksum = ip_checksum(msg) #create packet packet_to_send = make_packet(str(expected_seq_num), msg, checksum) #related variables for select inputs = [s] #socket outputs = [] timeout = 0 #when timeout is 0, it basically polls readable = [] writeable = [] expectional =[] #now keep talking with the client while 1: if current_state == states_list[0]: readable, writeable, expectional = select.select(inputs, outputs, inputs, timeout)
while(1) : seq = 0 try : while True: msg = raw_input('Enter message to send(Q for quit): ') if msg == 'Q' or msg == 'q': sys.exit() ack_received = False while not ack_received: #Set the whole string tosend = ip_checksum(msg) + str(seq) + msg rand = random.randint(1, 20) if rand >= 1 and rand <= 5: print("Corrupted") tosend = corrupt(tosend) s.sendto(tosend, (host, port)) # receive data from client (data, addr) try: reply, addr = s.recvfrom(1024) except socket.timeout: print('Timeout') else: