From 6ed09e6b7024deae41159a8da6ee5cb4fc73af6c Mon Sep 17 00:00:00 2001
From: mgstabrani <mgstabrani19@gmail.com>
Date: Thu, 25 Nov 2021 23:06:04 +0700
Subject: [PATCH] Fix checksum and refactor
---
buffer.py | 3 ---
client.py | 60 ++++++------------------------------------------------
segment.py | 20 +++++++-----------
server.py | 53 +++++------------------------------------------
4 files changed, 18 insertions(+), 118 deletions(-)
diff --git a/buffer.py b/buffer.py
index e3911be..1802060 100644
--- a/buffer.py
+++ b/buffer.py
@@ -7,7 +7,6 @@ class FileBuffer:
pass
def read(self, filename) -> List[Segment]:
- # To-Do
# return array of segment,
# array of segment hanya berisi data, sementara header kosong
f = open(filename, "rb")
@@ -21,12 +20,10 @@ class FileBuffer:
return segments
def write(self, segments:List[Segment], filename):
- # To-Do
# write array of segment to file
with open(filename, 'wb') as f:
for seg in segments:
data = seg.get_data()
- print(data[:10])
f.write(data)
return
diff --git a/client.py b/client.py
index bd00aa2..5e56575 100644
--- a/client.py
+++ b/client.py
@@ -15,7 +15,6 @@ class Client():
try:
self.handshake()
self.recv_file()
- self.close_con()
self.save_file()
except ConnectionError:
log("!", "Connecion error.")
@@ -43,12 +42,12 @@ class Client():
log("!", "Listening for three-way handshake...")
def handshake(self):
- # To-Do
rcvd = Segment()
while 1:
byte, server_addr = self.recv()
rcvd.from_bytes(byte)
if not rcvd.test_checksum():
+ log("!", "Checksum failed.")
raise ConnectionError
if rcvd.getSYN():
break;
@@ -60,6 +59,7 @@ class Client():
seg.set_ack_no(rcvd.get_seq_no())
seg.setSYN()
seg.setACK()
+ seg.set_checksum(seg.count_checksum())
self.send(seg.to_bytes(), server_addr)
log(f"Segment SEQ={rcvd.get_seq_no()}, SYN", "Received, Ack sent")
log(f"Segment SEQ={seg.get_seq_no()}, SYN", "Sent")
@@ -73,7 +73,6 @@ class Client():
return
def recv_file(self):
- # To-Do
base = 0 # antrian ngirim data
data_ret = b''
@@ -81,7 +80,6 @@ class Client():
segments = []
while True:
data, server_addr = self.recv() # nerima data dari server
- file_received = self.FILEPATH # deklarasi buat tempat penyimpanan berkas
rcvd = Segment()
rcvd.from_bytes(data) # unwrap the data
@@ -92,12 +90,12 @@ class Client():
ack_segment.setACK()
ack_segment.set_seq_no(0)
ack_segment.set_ack_no(rcvd.get_seq_no())
+ ack_segment.set_checksum(ack_segment.count_checksum())
self.send(ack_segment.to_bytes(), server_addr)
log("!", f"Segment SEQ={rcvd.get_seq_no()}: Received {rcvd.isData()}, Sent {ack_segment.getACK()}")
data_ret += ack_segment.get_data()
- print(rcvd.bytes[12:22])
segments.append(rcvd)
else:
log("!", f"Data is empty")
@@ -109,6 +107,7 @@ class Client():
log("!", "Closing Connection ...")
seg = Segment(300, rcvd.get_seq_no())
seg.setACK()
+ seg.set_checksum(seg.count_checksum())
self.send(seg.to_bytes(), self.DST_ADDR)
log(f"Segment SEQ={rcvd.get_seq_no()}, FIN", "Received, Ack sent")
@@ -116,6 +115,7 @@ class Client():
seg = Segment(seg.get_seq_no())
seg.setFIN()
+ seg.set_checksum(seg.count_checksum())
self.send(seg.to_bytes(), self.DST_ADDR)
log(f"Segment SEQ={seg.get_seq_no()}, FIN", "Sent")
@@ -125,55 +125,14 @@ class Client():
or (rcvd.get_ack_no() != seg.get_seq_no()):
raise ConnectionError
log(f"Segment SEQ={seg.get_seq_no()}, FIN", "Acked")
- # self.socket.close()
self.segments = segments
break
elif not rcvd.test_checksum() or rcvd.get_seq_no() > base:
- # refuse_segment = Segment()
- # refuse_segment.set_seq_no(0)
- # refuse_segment.set_ack_no(base)
- # refuse_segment.setSYN()
- # self.send(refuse_segment.to_bytes(), server_addr)
-
log("!", f"WARNING!!! Segment refused")
elif rcvd.get_seq_no() < base:
- # ack_segment = Segment()
- # ack_segment.set_seq_no(0)
- # ack_segment.set_ack_no(base)
- # ack_segment.getACK()
- # self.send(ack_segment.to_bytes(), server_addr)
-
log("!", f"WARNING!!! Segment already received")
-
- # ini mau void apa mau return data_ret yakk wkwkkwkwkwkwk
- return
-
- def close_con(self):
- # To-Do
-
- # byte, _ = self.recv()
- # rcvd = Segment().from_bytes(byte)
- # if (not rcvd.test_checksum()) or (not rcvd.getFIN()):
- # raise ConnectionError
- # seg = Segment(300, rcvd.get_seq_no())
- # seg.setACK()
- # self.send(seg.to_bytes(), self.DST_ADDR)
- # log(f"Segment SEQ={rcvd.get_seq_no()}, FIN", "Received, Ack sent")
-
- # seg = Segment(seg.get_seq_no())
- # seg.setFIN()
- # self.send(seg.to_bytes(), self.DST_ADDR)
- # log(f"Segment SEQ={seg.get_seq_no()}, FIN", "Sent")
-
- # byte, _ = self.recv()
- # rcvd = Segment().from_bytes(byte)
- # if (not rcvd.test_checksum()) or (not rcvd.getACK()) \
- # or (rcvd.get_ack_no() != seg.get_seq_no()):
- # raise ConnectionError
- # log(f"Segment SEQ={seg.get_seq_no()}, FIN", "Acked")
- # # self.socket.close()
return
def save_file(self):
@@ -181,15 +140,8 @@ class Client():
fb.write(self.segments, self.FILEPATH)
if __name__=="__main__":
- # try:
- # port=int(sys.argv[1])
- # Client(port=port)
- # except KeyboardInterrupt:
- # pass
- # except :
- # Client()
if len(sys.argv) > 2:
- Client(port=int(sys.argv[1]))
+ Client(port=int(sys.argv[1]), filepath=sys.argv[2])
elif len(sys.argv) > 1:
Client(port=int(sys.argv[1]))
else :
diff --git a/segment.py b/segment.py
index 2f45e1a..7f5f180 100644
--- a/segment.py
+++ b/segment.py
@@ -82,15 +82,15 @@ class Segment():
return not self.bytes[8]
def get_checksum(self):
- return self.bytes[10] << 8 + self.bytes[11]
+ return (self.bytes[10] << 8) + self.bytes[11]
def set_checksum(self, val):
self.bytes[10] = val >> 8 & 0xff
self.bytes[11] = val & 0xff
def count_checksum(self):
- # To-Do
- # ...
+ byte10 = self.bytes[10]
+ byte11 = self.bytes[11]
self.bytes[10] = 0 # dangerous
self.bytes[11] = 0 # dangerous
data = self.to_bytes()
@@ -106,11 +106,13 @@ class Segment():
checksum += w
checksum = (checksum >> 16) + (checksum & 0xFFFF)
+ self.bytes[10] = byte10 # dangerous
+ self.bytes[11] = byte11 # dangerous
+
return checksum
def test_checksum(self):
- # return self.count_checksum == self.get_checksum
- return True
+ return self.count_checksum() == self.get_checksum()
def to_bytes(self):
return bytes(self.bytes)
@@ -133,14 +135,6 @@ class Segment():
print(self.bytes[:50])
if __name__=="__main__":
- # seg = Segment()
- # seg.setFIN()
- # seg.set_seq_no()
- # seg.set_ack_no()
- # checksum = seg.count_checksum()
- # seg.set_checksum(checksum)
- # seg = Segment(seqno, ackno, flag, data)
-
seg = Segment(200, 199)
seg.from_file("halo.txt")
seg.set_checksum(seg.count_checksum())
diff --git a/server.py b/server.py
index eb4b6c2..1ec8d4f 100644
--- a/server.py
+++ b/server.py
@@ -58,11 +58,11 @@ class Server():
break
def handshake(self, client_addr):
- # To-DO
log("!", "Commencing three-way handshake... ")
segment = Segment()
segment.set_seq_no(100)
segment.setSYN()
+ segment.set_checksum(segment.count_checksum())
self.send(segment.to_bytes(), client_addr)
log(f"Segment SEQ={segment.get_seq_no()}, SYN", "Sent")
@@ -70,10 +70,6 @@ class Server():
recved = Segment().from_bytes(byte)
if (not recved.test_checksum()) or (not recved.getACK()) \
or (recved.get_ack_no() != segment.get_seq_no()):
- # print(recved.getACK())
- # print(recved.get_ack_no())
- # print(segment.get_seq_no())
- # print(recved.bytes[:12])
raise ConnectionError
log(f"Segment SEQ={segment.get_seq_no()}, SYN", "Acked")
@@ -81,31 +77,25 @@ class Server():
segment.set_seq_no(recved.get_ack_no()+1)
segment.set_ack_no(recved.get_seq_no())
segment.setACK()
+ segment.set_checksum(segment.count_checksum())
self.send(segment.to_bytes(), client_addr)
log(f"Segment SEQ={recved.get_seq_no()}, SYN", "Received, Ack sent")
return True
def send_file(self, client_addr):
- # To-Do
- print("====")
- print(self.FILE_PATH)
- print("===")
list_of_segments = FileBuffer().read(self.FILE_PATH)
count = len(list_of_segments)
log("!", f"File segmented into {count} segments")
- acked = [False for _ in range(count)]
-
base = 0
timeout = 0
while True:
for i in range(self.N):
if (base+i) < count:
- print("======")
- print(base+i)
seg = list_of_segments[base+i]
seg.set_seq_no(base+i)
+ seg.set_checksum(seg.count_checksum())
self.send(seg.to_bytes(), client_addr)
log(f"Segment SEQ={seg.get_seq_no()}", "Sent")
try:
@@ -117,7 +107,6 @@ class Server():
byte, _ = self.recv()
rcvd = Segment().from_bytes(byte)
if rcvd.test_checksum() and rcvd.get_ack_no() == base:
- print(list_of_segments[base].bytes[12:22])
log(f"Segment SEQ={rcvd.get_ack_no()}", "Acked")
base += 1
if base >= count:
@@ -128,41 +117,13 @@ class Server():
timeout += 1
if timeout == 3:
raise ConnectionError
-# '''
-# | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
-# ^ ^
-# function sender is
-# Sb := 0
-# Sm := N + 1
-# while True:
-# if you receive an ack number where Rn > Sb then
-# Sm := (Sm − Sb) + Rn
-# Sb := Rn
-# if no packet is in transmission then
-# Transmit packets where Sb ≤ Sn ≤ Sm.
-# Packets are transmitted in order
-
-
-# function receiver is
-# Rn := 0
-# Do the following forever:
-# if Sn = Rn and the packet is error free then
-# Accept the packet and send it to a higher layer
-# Rn := Rn + 1
-# else
-# Refuse packet
-# Send acknowledgement for last received packet
-# '''
-
def close_con(self, client_addr):
- # To-Do
- # self.socket.close()
- # log("!", "Connection is closed")
log("!", "Closing Connection ...")
seg = Segment(100)
seg.setFIN()
+ seg.set_checksum(seg.count_checksum())
self.send(seg.to_bytes(), client_addr)
log(f"Segment SEQ={seg.get_seq_no()}, FIN", "Sent")
@@ -179,16 +140,12 @@ class Server():
raise ConnectionError
seg = Segment(seg.get_seq_no()+1, rcvd.get_seq_no())
seg.setACK()
+ seg.set_checksum(seg.count_checksum())
self.send(seg.to_bytes(), client_addr)
log(f"Segment SEQ={rcvd.get_seq_no()}, FIN", "Received, Ack sent.")
return True
if __name__=="__main__":
- # try:
- # Server(port=int(sys.argv[1]), filepath=sys.argv[2]);
- # except:
- # log("!", "Using another port")
- # Server(filepath=sys.argv[2]);
if len(sys.argv) > 2:
Server(port=int(sys.argv[1]), filepath=sys.argv[2]);
elif len(sys.argv) > 1:
--
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