def rdt_send(clientAddr, data):
global TO_SEND_SEQ
global SEND_BUF
global SEND_BUF_SEQ
global TIMER
global EXPIRED
TIMER = threading.Timer(TIMER_SET, timerHandler)
TIMER.start()
print 'TIMER should start'
endSignal = 1
checkpoint = 0
while 1:
if len(SEND_BUF_SEQ) < N:
m = prepareDatagram(TO_SEND_SEQ, data)
if not m:
if endSignal == 1:
endSignal = 0
m = util.buildHeader(TO_SEND_SEQ, 'END', 2)
m += 'END'
elif len(SEND_BUF_SEQ) == 0:
break
else:
checkpoint = 1
if checkpoint == 0:
try:
THREAD_LOCK.acquire()
s.sendto(m, clientAddr)
SEND_BUF.append(m)
SEND_BUF_SEQ.append(TO_SEND_SEQ)
# print "TO_SEND_SEQ: " + str(TO_SEND_SEQ)
TO_SEND_SEQ = TO_SEND_SEQ + 1
# time.sleep(0.01)
THREAD_LOCK.release()
except socket.error, msg:
print 'Error Code : ' + str(msg[0]) + ' Message ' + msg[1]
sys.exit()
if EXPIRED == 1 and len(SEND_BUF) > 0:
# print "waiting to resend all..."
print "Time Out, sequence number = " + str(SEND_BUF_SEQ[0]*MSS)
THREAD_LOCK.acquire()
TIMER.cancel()
# TIMER.join()
THREAD_LOCK.release()
THREAD_LOCK.acquire()
# print "SEND_BUF_SEQ: " + str(SEND_BUF_SEQ)
for m in SEND_BUF:
# errno, seq_no, dataText = util.parseDatagram(m, 0)
# print "IN RESEND" + str(seq_no)
s.sendto(m, clientAddr)
# print "SEND_BUF ALL SENT!!"
THREAD_LOCK.release()
EXPIRED = 0
THREAD_LOCK.acquire()
TIMER = threading.Timer(TIMER_SET, timerHandler)
TIMER.start()
THREAD_LOCK.release()
def rdt_send(clientAddr, data):
global TO_SEND_SEQ
global SEND_BUF
global SEND_BUF_SEQ
global TIMER
global EXPIRED
TIMER = threading.Timer(TIMER_SET, timerHandler)
TIMER.start()
print "TIMER should start"
endSignal = 1
checkpoint = 0
while 1:
if len(SEND_BUF_SEQ) < N:
m = prepareDatagram(TO_SEND_SEQ, data)
if not m:
if endSignal == 1:
endSignal = 0
m = util.buildHeader(TO_SEND_SEQ, "END", 2)
m += "END"
elif len(SEND_BUF_SEQ) == 0:
break
else:
checkpoint = 1
if checkpoint == 0:
try:
THREAD_LOCK.acquire()
s.sendto(m, clientAddr)
SEND_BUF.append(m)
SEND_BUF_SEQ.append(TO_SEND_SEQ)
# print "TO_SEND_SEQ: " + str(TO_SEND_SEQ)
TO_SEND_SEQ = TO_SEND_SEQ + 1
# time.sleep(0.01)
THREAD_LOCK.release()
except socket.error, msg:
print "Error Code : " + str(msg[0]) + " Message " + msg[1]
sys.exit()
if EXPIRED == 1 and len(SEND_BUF) > 0:
# print "waiting to resend all..."
print "Time Out, sequence number = " + str(SEND_BUF_SEQ[0] * MSS)
THREAD_LOCK.acquire()
TIMER.cancel()
# TIMER.join()
THREAD_LOCK.release()
THREAD_LOCK.acquire()
# print "SEND_BUF_SEQ: " + str(SEND_BUF_SEQ)
for m in SEND_BUF:
# errno, seq_no, dataText = util.parseDatagram(m, 0)
# print "IN RESEND" + str(seq_no)
s.sendto(m, clientAddr)
# print "SEND_BUF ALL SENT!!"
THREAD_LOCK.release()
EXPIRED = 0
THREAD_LOCK.acquire()
TIMER = threading.Timer(TIMER_SET, timerHandler)
TIMER.start()
THREAD_LOCK.release()
def prepareDatagram(seq_no, data): startIndex = seq_no * MSS content = data[startIndex:startIndex+MSS] if not content: return None # print "seq_no: " + str(seq_no) hdr = util.buildHeader(seq_no, content, 0) return hdr + content
def prepareDatagram(seq_no, data):
startIndex = seq_no * MSS
content = data[startIndex : startIndex + MSS]
if not content:
return None
# print "seq_no: " + str(seq_no)
hdr = util.buildHeader(seq_no, content, 0)
return hdr + content
def FTPReceiver(s, p=0.05):
global P # Probability of packet loss
P = p
# Initialize the Sequence number
lastSEQNO = -1
max_seq_no = -1
firstTime = True
MSS = 0
oldSEQNO = -1
buffer=""
while 1:
packet = s.recvfrom(1100)
data = packet[0]
serverAddr = packet[1]
if not data:
continue
if firstTime:
MSS = len(data) - 64
firstTime = False
# Simulate a random drop process
randomNum = random.random()
# print randomNum
if randomNum <= P:
if oldSEQNO != lastSEQNO:
oldSEQNO = lastSEQNO
print "Packet loss, sequence num = " + str((lastSEQNO + 1) * MSS)
continue
errno, seq_no, dataText = util.parseDatagram(data, 0)
# print "SEQ_NO:" + str(seq_no)
# print "LAST_ACK:" + str(lastSEQNO)
if seq_no > max_seq_no:
max_seq_no = seq_no
if errno == 0:
if seq_no == lastSEQNO + 1:
lastSEQNO = seq_no
buffer+=dataText
reply = util.buildHeader(lastSEQNO+1, '', 1)
s.sendto(reply, serverAddr)
elif errno == 1:
print "Unmatched checksum, datagram is corrupted"
break
elif errno == 2:
print "Unmatched indicator, datagram is corrupted"
break
else:
if seq_no == lastSEQNO + 1:
lastSEQNO = seq_no
reply = util.buildHeader(lastSEQNO+1, '', 3)
s.sendto(reply, serverAddr)
if max_seq_no == lastSEQNO:
print "Transfer finished!"
print "SEQ_NO "+str((lastSEQNO+1)*MSS)+ " is sent!"
break
s.close()
return buffer
def FTPReceiver(s, p=0.05):
global P # Probability of packet loss
P = p
# Initialize the Sequence number
lastSEQNO = -1
max_seq_no = -1
firstTime = True
MSS = 0
oldSEQNO = -1
buffer = ""
while 1:
packet = s.recvfrom(1100)
data = packet[0]
serverAddr = packet[1]
if not data:
continue
if firstTime:
MSS = len(data) - 64
firstTime = False
# Simulate a random drop process
randomNum = random.random()
# print randomNum
if randomNum <= P:
if oldSEQNO != lastSEQNO:
oldSEQNO = lastSEQNO
print "Packet loss, sequence num = " + str(
(lastSEQNO + 1) * MSS)
continue
errno, seq_no, dataText = util.parseDatagram(data, 0)
# print "SEQ_NO:" + str(seq_no)
# print "LAST_ACK:" + str(lastSEQNO)
if seq_no > max_seq_no:
max_seq_no = seq_no
if errno == 0:
if seq_no == lastSEQNO + 1:
lastSEQNO = seq_no
buffer += dataText
reply = util.buildHeader(lastSEQNO + 1, '', 1)
s.sendto(reply, serverAddr)
elif errno == 1:
print "Unmatched checksum, datagram is corrupted"
break
elif errno == 2:
print "Unmatched indicator, datagram is corrupted"
break
else:
if seq_no == lastSEQNO + 1:
lastSEQNO = seq_no
reply = util.buildHeader(lastSEQNO + 1, '', 3)
s.sendto(reply, serverAddr)
if max_seq_no == lastSEQNO:
print "Transfer finished!"
print "SEQ_NO " + str((lastSEQNO + 1) * MSS) + " is sent!"
break
s.close()
return buffer
