def replyDownload(s, RcvBuffer, addr):
# 服务端日志
logf = open('../log/server-log.txt', mode='w')
logf.write("Replying Download ")
print("Replying Download ")
uniSize = 1024 + 8
commandformat = '2I'
ackformat = '2I'
mss = 1024 #读取字节数
format = '2I1024s'
flowCtlrFormat = 'Ii'
flowCtlrLen = struct.calcsize(flowCtlrFormat)
receiveSize = 8
InitialSeqNum = 1
print("Replying InitialSeqNum ")
s.sendto(struct.pack(commandformat, 1, InitialSeqNum), addr)
while True:
fileInfo, addr = s.recvfrom(1024)
if len(fileInfo) != 8:
fileInfo = str(fileInfo, encoding='utf-8')
print("File Info : ", fileInfo)
break
if os.path.exists(fileInfo) == False:
s.sendto(struct.pack(commandformat, InitialSeqNum, 0), addr)
print("file requested does not exists")
return
print("ACK file exist")
s.sendto(struct.pack(commandformat, InitialSeqNum, 1), addr)
s.setblocking(0)
f = open(fileInfo, mode='rb')
# 超时重传机制
TTL = 3
Timer = 3
RcvBuffer = 0
# GBN机制
Sendbase = InitialSeqNum # 已发送但未被确认的最小序号
NextSeqNum = InitialSeqNum # 下一个要发送的字节序号
Window = [] # 缓存已发送但未确认的分组
windowSize = 10 # 窗口大小
baseIndex = 0
avaliable = 0
# 流控制机制
LastByteSent = 0
# 最后一个已经发送的字节
LastByteAcked = 0
# 最后一个被确认的字节
rwnd = RcvBuffer
FileEndFlag = 0
AllAcked = 0
# 拥塞控制机制
cwnd = 1
ssthresh = 16
State = 0 # 0：慢启动， 1：拥塞避免
dupACKcount = 0
lastACK = 0
print("Starting file transmition")
# for i in range(1000):
while FileEndFlag == 0 or AllAcked == 0:
#event : data recieved from application : bug not fixed
if (LastByteSent - LastByteAcked
) <= rwnd * mss and (NextSeqNum - Sendbase) / mss < windowSize:
data = f.read(mss)
if len(data) < mss: #补长
data = data + bytes(mss - len(data))
FileEndFlag = 1
Window.append(initPacket(NextSeqNum, data))
AllAcked = 0
s.sendto(struct.pack(format, NextSeqNum, 0, data), addr)
logf.write("sending : " + str(NextSeqNum))
for x in range(len(Window)):
logf.write(str(Window[x].seqNum))
logf.write("\n")
LastByteSent = NextSeqNum - 1
NextSeqNum = NextSeqNum + mss
elif (LastByteSent - LastByteAcked) > rwnd * mss:
logf.write('\nsending flowCtlr pkt : ' + str(NextSeqNum - mss) +
' rwnd : ' + str(rwnd) + "\n")
logf.write('LastByteSent : ' + str(LastByteSent) +
'LastByteAcked : ' + str(LastByteAcked) + "\n")
s.sendto(struct.pack(flowCtlrFormat, NextSeqNum - mss, -1), addr)
# NextSeqNum = NextSeqNum + 1
#event : ACK received, with field value of y
reply = 0
try:
reply, dstAddr = s.recvfrom(receiveSize)
ackSeq, rwnd = struct.unpack(ackformat, reply)
LastByteAcked = ackSeq + mss # 流控制中，ack seq 不变化
if lastACK != ackSeq:
if State == 0:
cwnd += 1
else:
cwnd += 1 / cwnd
dupACKcount = 0
lastACK = ackSeq
else:
duoACKcount += 1
logf.write("recieve ACK : " + str(ackSeq))
for x in range(len(Window)):
logf.write(str(Window[x].seqNum))
if Sendbase <= ackSeq: # 累计确认，之前的都是正确确认收到的
Sendbase = ackSeq + mss
logf.write("update sendbase : " + str(Sendbase) + "\n")
while len(Window) != 0:
if Window[0].seqNum < Sendbase:
del Window[0]
else:
break
if Sendbase != NextSeqNum: #如果当前还有已发送但未被确认的分组: reset timer
Timer = 0
if len(Window) == 0:
AllAcked = 1
# print(reply)
logf.write("updated Window : ")
for x in Window:
logf.write(str(x.seqNum))
except BlockingIOError:
pass
#event : timer out / duoACKcount
Timer += 1
if Timer == TTL or dupACKcount == 3:
State = 0
ssthresh = cwnd / 2
cwnd = 1
duoACKcount = 0
Timer = 0
# if Sendbase != NextSeqNum and (LastByteSent-LastByteAcked) <= rwnd*mss:
if len(
Window
) != 0: #retransmit not-ack pkt with smallest seq(Sendbase)(Window[0])?
logf.write("TIME OUT : retransmit " + str(Window[0].seqNum) +
"\n")
retransmit = struct.pack(format, Window[0].seqNum, 0,
Window[0].data)
s.sendto(retransmit, addr)
#挥手
Timer = 3
while True:
print("Starting connection closing")
FIN = -2
if Timer == 3:
s.sendto(struct.pack(flowCtlrFormat, 0, FIN), addr)
Timer = 0
Timer += 1
try:
reply, addr = s.recvfrom(receiveSize)
seq, FIN = struct.unpack(commandformat, reply)
print("Close connection ack recieved")
while True:
try:
reply, addr = s.recvfrom(receiveSize)
print("third wave recieved")
break
except BlockingIOError:
pass
break
except BlockingIOError:
pass
f.close()
# s.close()
logf.close()
def UploadFile(fileLocal, dstAddr):
logf = open('../log/client-log.txt', mode='w')
logf.write("Commanding : upload file " + fileLocal + " to " + dstAddr)
f = open(fileLocal, mode='rb')
filePath = "D:/"
fileName, fileFormat = parseFileName(fileLocal)
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
InitialSeqNum = 1
mss = 1024 #读取字节数
format = '2I1024s'
ackformat = '2I'
commandformat = '2I'
flowCtlrFormat = 'Ii'
receiveSize = struct.calcsize(ackformat)
dstIP = dstAddr
dstPort = 9999
s.setblocking(0)
# 超时重传机制
TTL = 3
Timer = 3
RcvBuffer = 0
# set up connection：
while True:
command = 1 #上传命令
print("sending command ", command, " and initial seqNum ",
InitialSeqNum)
if Timer == TTL:
s.sendto(struct.pack(commandformat, command, InitialSeqNum),
(dstIP, dstPort))
Timer = 0
TTL *= 2
Timer += 1
try:
print(receiveSize)
reply, addr = s.recvfrom(receiveSize)
RcvBuffer, seq = struct.unpack(commandformat, reply)
print("command pkt ack recieved")
Timer = 3
while True:
if Timer == TTL:
print("sending file info")
fileInfo = bytes(filePath.encode('utf-8')) + bytes(
fileName.encode('utf-8')) + bytes(
("." + fileFormat).encode('utf-8'))
s.sendto(fileInfo, (dstIP, dstPort))
# s.sendto(bytes(filePath.encode('utf-8')), (dstIP, dstPort))
Timer += 1
try:
reply, addr = s.recvfrom(receiveSize)
print("server : fileInfo recieved ( connection setup")
break
except BlockingIOError:
pass
break
except BlockingIOError:
pass
# GBN机制
Sendbase = InitialSeqNum # 已发送但未被确认的最小序号
NextSeqNum = InitialSeqNum # 下一个要发送的字节序号
Window = [] # 缓存已发送但未确认的分组
windowSize = 10 # 窗口大小
# 流控制机制
LastByteSent = 0
# 最后一个已经发送的字节
LastByteAcked = 0
# 最后一个被确认的字节
rwnd = RcvBuffer
FileEndFlag = 0
AllAcked = 0
# 拥塞控制机制
cwnd = 1
ssthresh = 16
State = 0 # 0：慢启动， 1：拥塞避免
dupACKcount = 0
lastACK = 0
print("Starting file transmition")
# for i in range(1000):
while FileEndFlag == 0 or AllAcked == 0:
#event : data recieved from application : bug not fixed
if (LastByteSent - LastByteAcked
) <= rwnd * mss and (NextSeqNum - Sendbase) / mss < windowSize:
data = f.read(mss)
if len(data) < mss: #补长
data = data + bytes(mss - len(data))
FileEndFlag = 1
Window.append(initPacket(NextSeqNum, data))
AllAcked = 0
s.sendto(struct.pack(format, NextSeqNum, 0, data),
(dstIP, dstPort))
logf.write("sending : " + str(NextSeqNum))
for x in range(len(Window)):
logf.write(str(Window[x].seqNum))
logf.write("\n")
LastByteSent = NextSeqNum - 1
NextSeqNum = NextSeqNum + mss
elif (LastByteSent - LastByteAcked) > rwnd * mss:
logf.write('\nsending flowCtlr pkt : ' + str(NextSeqNum - mss) +
' rwnd : ' + str(rwnd) + "\n")
logf.write('LastByteSent : ' + str(LastByteSent) +
'LastByteAcked : ' + str(LastByteAcked) + "\n")
s.sendto(struct.pack(flowCtlrFormat, NextSeqNum - mss, -1),
(dstIP, dstPort))
# NextSeqNum = NextSeqNum + 1
#event : ACK received, with field value of y
reply = 0
try:
reply, dstAddr = s.recvfrom(receiveSize)
ackSeq, rwnd = struct.unpack(ackformat, reply)
LastByteAcked = ackSeq + mss # 流控制中，ack seq 不变化
if lastACK != ackSeq:
if State == 0:
cwnd += 1
else:
cwnd += 1 / cwnd
dupACKcount = 0
lastACK = ackSeq
else:
duoACKcount += 1
logf.write("recieve ACK : " + str(ackSeq))
for x in range(len(Window)):
logf.write(str(Window[x].seqNum))
if Sendbase <= ackSeq: # 累计确认，之前的都是正确确认收到的
Sendbase = ackSeq + mss
logf.write("update sendbase : " + str(Sendbase) + "\n")
while len(Window) != 0:
if Window[0].seqNum < Sendbase:
del Window[0]
else:
break
if Sendbase != NextSeqNum: #如果当前还有已发送但未被确认的分组: reset timer
Timer = 0
if len(Window) == 0:
AllAcked = 1
# print(reply)
logf.write("updated Window : ")
for x in Window:
logf.write(str(x.seqNum))
except BlockingIOError:
pass
#event : timer out / duoACKcount
Timer += 1
if Timer == TTL or dupACKcount == 3:
State = 0
ssthresh = cwnd / 2
cwnd = 1
duoACKcount = 0
Timer = 0
# if Sendbase != NextSeqNum and (LastByteSent-LastByteAcked) <= rwnd*mss:
if len(
Window
) != 0: #retransmit not-ack pkt with smallest seq(Sendbase)(Window[0])?
logf.write("TIME OUT : retransmit " + str(Window[0].seqNum) +
"\n")
retransmit = struct.pack(format, Window[0].seqNum, 0,
Window[0].data)
s.sendto(retransmit, (dstIP, dstPort))
#挥手
Timer = 3
while True:
print("Starting connection closing")
FIN = -2
if Timer == 3:
s.sendto(struct.pack(flowCtlrFormat, 0, FIN), (dstIP, dstPort))
Timer = 0
Timer += 1
try:
reply, addr = s.recvfrom(receiveSize)
seq, FIN = struct.unpack(commandformat, reply)
print("Close connection ack recieved")
while True:
try:
reply, addr = s.recvfrom(receiveSize)
print("third wave recieved")
break
except BlockingIOError:
pass
break
except BlockingIOError:
pass
f.close()
s.close()
logf.close()
else:
logf.write("flow control pkt recieved : " + str(seq) + "\n")
s.sendto(struct.pack(flowCtlrFormat, seq, rwnd), addr)
continue
seq, ack, w = struct.unpack(format, data)
logf.write("Recieved seq: " + str(seq) + "\n")
if seq < expSeqNum: # 丢弃冗余分组
logf.write("redundant pkt：" + str(seq) + "\n")
continue
elif seq > expSeqNum: # 若缓存仍有空间，缓存乱序到达的pkt
if not ReceiveBuffer.full() and seq not in bufferedSeq:
logf.write("put buffer : " + str(seq) + "\n")
ReceiveBuffer.put(initPacket(seq, w))
bufferedSeq.append(seq)
rwnd -= 1
else: #seq == expSeqNum:
ackSeq = seq
f.write(w)
expSeqNum += len(w)
#检查buffer中有无 顺序可写的数据包
if not ReceiveBuffer.empty(): # buffer不为空
tmp = ReceiveBuffer.get() # 取队头元素
bufferedSeq.remove(tmp.seqNum)
while tmp.seqNum <= expSeqNum:
if tmp.seqNum < expSeqNum: # 若队列中有小于expNum的缓存（冗余），丢弃
if ReceiveBuffer.empty():
def DownloadFile(filePath, dstAddr):
logf = open('../log/client-log.txt', mode='w')
logf.write("Commanding : download file " + filePath + " from " + dstAddr)
uniSize = 1024 + 8
format = '2I1024s'
commandformat = '2I'
ackformat = '2I'
flowCtlrFormat = 'Ii'
flowCtlrLen = struct.calcsize(flowCtlrFormat)
receiveSize = 8
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
# s.sendto(struct.pack(commandformat, ), )
dstIP = dstAddr
dstPort = 9999
InitialSeqNum = 1
RcvBufferSize = 20
s.setblocking(0)
# set up connection： bug not fixed
TTL = 3
Timer = 1
while True:
command = 0 #下载命令
print("sending command ", command, " and initial seqNum ",
InitialSeqNum)
if Timer == TTL:
s.sendto(struct.pack(commandformat, command, RcvBufferSize),
(dstIP, dstPort))
Timer = 0
TTL *= 2
Timer += 1
try:
# print(s.recvfrom(receiveSize))
reply, addr = s.recvfrom(receiveSize)
seq, InitialSeqNum = struct.unpack(commandformat, reply)
print("command pkt ack recieved")
Timer = 3
while True:
if Timer == TTL:
print("sending file info")
fileInfo = bytes(filePath.encode('utf-8'))
s.sendto(fileInfo, (dstIP, dstPort))
Timer += 1
try:
reply, addr = s.recvfrom(receiveSize)
break
except BlockingIOError:
pass
break
except BlockingIOError:
pass
except OSError as e:
print(e)
seq, fileExist = struct.unpack(commandformat, reply)
if fileExist == 0:
print("Server : file requested does not exist")
s.close()
logf.write("Server : file requested does not exist")
logf.close()
return
# text, addr = s.recvfrom(struct.calcsize(commandformat))
# command, expSeqNum = struct.unpack(commandformat, text)
# print("Received command from ", addr, " command : ", command, " expSeq : ", expSeqNum)
# RcvBufferSize = 20 # 分配buffer数量
# s.sendto(struct.pack(commandformat, RcvBufferSize, expSeqNum), addr)
# 接收文件信息
# fileInfo, addr = s.recvfrom(1024)
# f = open(str(fileInfo, encoding = 'utf-8'), mode='wb')
# print("file info : ", fileInfo)
# s.sendto(struct.pack(commandformat, RcvBufferSize, expSeqNum), addr)
# 开始下载文件
s.setblocking(1)
fname, fformat = parseFileName(filePath)
f = open(("D:/testDownload/" + fname + "." + fformat), mode='wb')
ReceiveBuffer = PriorityQueue(RcvBufferSize) # 按缓存的seqNum从小到大排列
bufferedSeq = []
rwnd = RcvBufferSize # 缓存可用空间
expSeqNum = InitialSeqNum
# for i in range(1000):
while True:
data, addr = s.recvfrom(uniSize)
if len(data) == flowCtlrLen: # flow control or close connection
seq, testSeg = struct.unpack(flowCtlrFormat, data)
if seq == 0 and testSeg == -2:
print("Close connection pkt recieved")
break
else:
logf.write("flow control pkt recieved : " + str(seq) + "\n")
s.sendto(struct.pack(flowCtlrFormat, seq, rwnd), addr)
continue
seq, ack, w = struct.unpack(format, data)
logf.write("Recieved seq: " + str(seq) + "\n")
if seq < expSeqNum: # 丢弃冗余分组
logf.write("redundant pkt：" + str(seq) + "\n")
continue
elif seq > expSeqNum: # 若缓存仍有空间，缓存乱序到达的pkt
if not ReceiveBuffer.full() and seq not in bufferedSeq:
logf.write("put buffer : " + str(seq) + "\n")
ReceiveBuffer.put(initPacket(seq, w))
bufferedSeq.append(seq)
rwnd -= 1
else: #seq == expSeqNum:
ackSeq = seq
f.write(w)
expSeqNum += len(w)
#检查buffer中有无 顺序可写的数据包
if not ReceiveBuffer.empty(): # buffer不为空
tmp = ReceiveBuffer.get() # 取队头元素
bufferedSeq.remove(tmp.seqNum)
while tmp.seqNum <= expSeqNum:
if tmp.seqNum < expSeqNum: # 若队列中有小于expNum的缓存（冗余），丢弃
if ReceiveBuffer.empty():
break
tmp = ReceiveBuffer.get()
bufferedSeq.remove(tmp.seqNum)
elif expSeqNum == tmp.seqNum: # 确认并写入磁盘
ackSeq = tmp.seqNum
f.write(w)
expSeqNum += len(tmp.data)
if ReceiveBuffer.empty():
break
tmp = ReceiveBuffer.get()
bufferedSeq.remove(tmp.seqNum)
if expSeqNum < tmp.seqNum:
ReceiveBuffer.put(tmp)
bufferedSeq.append(tmp.seqNum)
rwnd = RcvBufferSize - ReceiveBuffer.qsize()
logf.write("get excepted : " + str(seq) + "update expNum to : " +
str(expSeqNum) + "\n")
# 发送ack
ackPkt = struct.pack(ackformat, ackSeq, rwnd)
s.sendto(ackPkt, addr)
#close connection
s.sendto(struct.pack(commandformat, seq + 1, 1), addr)
s.sendto(struct.pack(commandformat, seq + 1, 2), addr)
s.close()
f.close()
logf.close()
dupACKcount = 0
lastACK = 0
print("Starting file transmition")
# for i in range(1000):
while FileEndFlag == 0 or AllAcked == 0:
#event : data recieved from application : bug not fixed
if (LastByteSent - LastByteAcked
) <= rwnd * mss and (NextSeqNum - Sendbase) / mss < windowSize:
data = f.read(mss)
if len(data) < mss: #补长
data = data + bytes(mss - len(data))
FileEndFlag = 1
Window.append(initPacket(NextSeqNum, data))
AllAcked = 0
s.sendto(struct.pack(format, NextSeqNum, 0, data), (dstIP, dstPort))
logf.write("sending : " + str(NextSeqNum))
for x in range(len(Window)):
logf.write(str(Window[x].seqNum))
logf.write("\n")
LastByteSent = NextSeqNum - 1
NextSeqNum = NextSeqNum + mss
elif (LastByteSent - LastByteAcked) > rwnd * mss:
logf.write('\nsending flowCtlr pkt : ' + str(NextSeqNum - mss) +
' rwnd : ' + str(rwnd) + "\n")
def replyUpload(s, expSeqNum, addr):
# 服务端日志
logf = open('../log/server-log.txt', mode='w')
logf.write("Replying Upload ")
uniSize = 1024 + 8
commandformat = '2I'
ackformat = '2I'
mss = 1024 #读取字节数
format = '2I1024s'
flowCtlrFormat = 'Ii'
flowCtlrLen = struct.calcsize(flowCtlrFormat)
RcvBufferSize = 20 # 分配buffer数量
s.sendto(struct.pack(commandformat, RcvBufferSize, expSeqNum), addr)
# 接收文件信息
fileInfo, addr = s.recvfrom(1024)
f = open(str(fileInfo, encoding='utf-8'), mode='wb')
print("file info : ", fileInfo)
s.sendto(struct.pack(commandformat, RcvBufferSize, expSeqNum), addr)
ReceiveBuffer = PriorityQueue(RcvBufferSize) # 按缓存的seqNum从小到大排列
bufferedSeq = []
rwnd = RcvBufferSize # 缓存可用空间
while True:
data, addr = s.recvfrom(uniSize)
if len(data) == flowCtlrLen: # flow control or close connection
seq, testSeg = struct.unpack(flowCtlrFormat, data)
if seq == 0 and testSeg == -2:
print("Close connection pkt recieved")
break
else:
logf.write("flow control pkt recieved : " + str(seq) + "\n")
s.sendto(struct.pack(flowCtlrFormat, seq, rwnd), addr)
continue
seq, ack, w = struct.unpack(format, data)
logf.write("Recieved seq: " + str(seq) + "\n")
if seq < expSeqNum: # 丢弃冗余分组
logf.write("redundant pkt：" + str(seq) + "\n")
continue
elif seq > expSeqNum: # 若缓存仍有空间，缓存乱序到达的pkt
if not ReceiveBuffer.full() and seq not in bufferedSeq:
logf.write("put buffer : " + str(seq) + "\n")
ReceiveBuffer.put(initPacket(seq, w))
bufferedSeq.append(seq)
rwnd -= 1
else: #seq == expSeqNum:
ackSeq = seq
f.write(w)
expSeqNum += len(w)
#检查buffer中有无 顺序可写的数据包
if not ReceiveBuffer.empty(): # buffer不为空
tmp = ReceiveBuffer.get() # 取队头元素
bufferedSeq.remove(tmp.seqNum)
while tmp.seqNum <= expSeqNum:
if tmp.seqNum < expSeqNum: # 若队列中有小于expNum的缓存（冗余），丢弃
if ReceiveBuffer.empty():
break
tmp = ReceiveBuffer.get()
bufferedSeq.remove(tmp.seqNum)
elif expSeqNum == tmp.seqNum: # 确认并写入磁盘
ackSeq = tmp.seqNum
f.write(w)
expSeqNum += len(tmp.data)
if ReceiveBuffer.empty():
break
tmp = ReceiveBuffer.get()
bufferedSeq.remove(tmp.seqNum)
if expSeqNum < tmp.seqNum:
ReceiveBuffer.put(tmp)
bufferedSeq.append(tmp.seqNum)
rwnd = RcvBufferSize - ReceiveBuffer.qsize()
logf.write("get excepted : " + str(seq) + "update expNum to : " +
str(expSeqNum) + "\n")
# 发送ack
ackPkt = struct.pack(ackformat, ackSeq, rwnd)
s.sendto(ackPkt, addr)
#close connection
s.sendto(struct.pack(commandformat, seq + 1, 1), addr)
s.sendto(struct.pack(commandformat, seq + 1, 2), addr)
# s.close()
f.close()
logf.close()