def send(content, to):
checksum = ip_checksum(content)
sv[2])
together = (addr, port)
sock = socket(AF_INET, SOCK_DGRAM)
sock.bind(together)
num=0
filename='file_received'+str(num)+'.txt'
fp=open(filename,'w')
num=1
while True:
message, address = sock.recvfrom(1024)
if message=='over':
fp.c
checksum = message[:2]
header = {}
header[0] = 0x45
import checksum
header = {}
header[0] = 0x45
header[1] = 0x00
header[2] = 0x00
header[3] = 0xe8
header[4] = 0x00
header[5] = 0x00
header[6] = 0x40
header[7] = 0x00
header[8] = 0x40
header[9] = 0x11
header[10] = 0x0
header[11] = 0x0
header[12] = 0x0a
header[13] = 0x86
header[14] = 0x33
header[15] = 0xf1
header[16] = 0x0a
header[17] = 0x86
header[18] = 0x33
header[19] = 0x76
print("Checksum is: %x" % (checksum.ip_checksum(header, len(header)),))
print("Should be BD92")
seq = 0
t0 = timeit.default_timer()
while offset < len(content):
if offset + SEGMENT_SIZE > len(content):
segment = content[offset:]
else:
segment = content[offset:offset + SEGMENT_SIZE]
offset += SEGMENT_SIZE
ack_received = False
while not ack_received:
if (count == 0):
print "first transmit package", seq
sock.settimeout(0.8)
sock.sendto(
ip_checksum(segment) + str(seq) + segment, dest)
count = count + 1
elif (count < 5):
print "retransmit package ", seq, "for", count, "times"
sock.settimeout(0.8)
sock.sendto(
ip_checksum(segment) + str(seq) + segment, dest)
count = count + 1
else:
print "I have retransmitted 5 times and I will close"
sock.close()
try:
message, address = sock.recvfrom(1024)
except timeout:
print "Timeout"
def send(content, to):
checksum = ip_checksum(content)
sock.sendto(checksum + content, to)
header = {}
header[0] = 0x45
import checksum
header = {}
header[0] = 0x45
header[1] = 0x00
header[2] = 0x00
header[3] = 0xe8
header[4] = 0x00
header[5] = 0x00
header[6] = 0x40
header[7] = 0x00
header[8] = 0x40
header[9] = 0x11
header[10] = 0x0
header[11] = 0x0
header[12] = 0x0a
header[13] = 0x86
header[14] = 0x33
header[15] = 0xf1
header[16] = 0x0a
header[17] = 0x86
header[18] = 0x33
header[19] = 0x76
print("Checksum is: %x" % (checksum.ip_checksum(header, len(header)), ))
print("Should be BD92")
packet_list.append(segment)
position = position + 1
break
else:
segment = content[offset:offset + SEGMENT_SIZE]
packet_list.append(segment)
position = position + 1
offset += SEGMENT_SIZE
sock.settimeout(1.0)
i = 0
ack_list = [0] * position
while (i < position):
sock.sendto(
ip_checksum(packet_list[i]) + str(seq) + packet_list[i],
dest)
print seq
seq = (seq + 1) % 5
i = i + 1
all_ack_received = False
while not all_ack_received:
try:
message, address = sock.recvfrom(1024)
except timeout:
print "Timeout"
all_ack_received = True
else:
checksum = message[:2]
ack_seq = message[5]
if ip_checksum(message[2:]
together = (addr, port)
filename = argv[5]
with open(filename) as f:
content = f.read()
sock = socket(AF_INET, SOCK_DGRAM)
sock.bind(together)
while True:
offset = 0
t0 = timeit.default_timer()
while offset < len(content):
if offset + SEGMENT_SIZE > len(content):
segment = content[offset:]
else:
segment = content[offset:offset + SEGMENT_SIZE]
offset += SEGMENT_SIZE
sock.sendto(ip_checksum(segment) + segment, dest)
print "total delay is ", timeit.default_timer() - t0
sock.sendto('over', dest)
x = int(
input(
"File transfer successfully finished, do you want to transfer again? Reply by 1(Yes) or 0(NO)"
))
if x == 0:
break
sock.close()
sock = socket(AF_INET, SOCK_DGRAM)
sock.bind(together)
num=0
filename='file_received'+str(num)+'.py'
fp=open(filename,'w')
num=1
while True:
message, address = sock.recvfrom(1024)
if message=='over':
fp.close()
filename='file_received'+str(num)+'.py'
num=num+1
fp=open(filename,'w')
continue
checksum = message[:2]
message=corrupt(message)
content = message[2:]
if ip_checksum(content) == checksum:
send("ACK", address)
print "successfully received"
fp.write(content)
else:
print "checksum error, discard the corrupted package"
fp.close()
num = 1
while True:
message, address = sock.recvfrom(1024)
if message == 'over':
fp.close()
filename = 'file_received' + str(num) + '.py'
num = num + 1
expected_seq = 0
fp = open(filename, 'w')
continue
checksum = message[:2]
seq = message[2]
seq1 = int(seq)
message = corrupt(message)
content = message[3:]
if (ip_checksum(content) == checksum and seq1 == expected_seq):
send("ACK" + seq, address)
fp.write(content)
expected_seq = (expected_seq + 1) % 5
elif ip_checksum(content) == checksum:
print "Out of order, discard!"
else:
print "package biterror"
# negative_seq = str(1 - expecting_seq)
#send("ACK" + negative_seq, address)
fp.close()
sock.close()
