def load_balance(c):
# get the servers current ip
ip = helper.find_ip()
# get the list of files
list_of_files = ledger.get_files_for_owner(ip)
# send confirmation
c.send(helper.pad_string("Server is ready load balance its files").encode())
# call the clients to get all the files locally and push them back
for file in list_of_files:
# run a os call to get the file
os.system("python3 client.py pull " + file)
# run an os call to send back the file to all the network
os.system("python3 client.py push " + file)
# remove the local copy
os.system("rm directory/" + file)
# send confirmation
c.send(helper.pad_string("Server has done load balancing its files").encode())
def lock_server(c, ip):
if lock.unlocked():
lock.acquire(ip)
print("Server locked by ", ip)
c.send(helper.pad_string("Server locked").encode())
else:
send_error("Error 124: Server already locked")
def update_ledger(c, filename, ip):
if(ip == helper.find_ip()):
print("Same server as client")
c.send(helper.pad_string("Server doesnt need your ledger").encode())
if lock.locked():
lock.release()
return
if lock.locked() and not lock.check_lock(ip):
send_error(c, "Error 123: Server currently busy")
return
# start with the time
start = time.time()
# open a temporary file to store the received bytes
file = open(filename, 'wb')
byte = 0
# send confirmation
c.send(helper.pad_string("Server is ready to update its ledger").encode())
while True:
# receive 1024 bytes at a time and write them to a file
bytes = c.recv(BYTES_TO_SEND)
bytes = encryption.decrypt_using_private_key(bytes)
file.write(bytes)
byte += BYTES_TO_SEND
# break infinite loop once all bytes are transferred
if not bytes:
break
# close the file once transfer is complete
file.close()
# time and space prints
end = time.time()
print("Finished running download of file %s in %.2f seconds" % (filename, float(end - start)))
print(byte, "bytes sent")
# Release the lock if one is present
if lock.locked() and lock.check_lock(ip):
print("Server lock released by ", lock.return_lock())
lock.release()
def send_ledger(c, ip):
start = time.time()
# open the ledger if it exists
try:
f = open(ledger.LEDGER_PATH, 'rb')
except:
send_error(c, "Error 176: Ledger doesn't exist on server machine")
c.close()
return
# send confirmation in plaintext
c.send(helper.pad_string("Server is ready to send ledger").encode())
# initialize an empty bytestring for the new pubkey
encryptedClientPubkey = b''
# client pubkey is received in 2 parts
for i in range(2):
encryptedClientPubkey += c.recv(REQUEST_MAX_LENGTH)
# decrypt the client pubkey
clientPubkey = encryption.decrypt_using_private_key(encryptedClientPubkey).decode()
# read bytes and set up counter
l = f.read(encryption.MESSAGE_CHUNK_LIMIT)
byte = BYTES_TO_SEND
# a forever loop untill file gets sent
while (l):
encrypted_l = encryption.encrypt_using_public_key(l, clientPubkey)
# send the bytes
c.send(encrypted_l)
# read more bytes and incrementing counter
l = f.read(encryption.MESSAGE_CHUNK_LIMIT)
byte += BYTES_TO_SEND
# time and space prints
end = time.time()
print("Sent ledger in %.2f seconds" % float(end - start))
print(byte, "bytes sent")
# close the connection with the client
c.close()
def receive_file(c, filename, ip):
if lock.locked() and not lock.check_lock(ip):
send_error(c, "Error 123: Server currently busy")
return
if lock.unlocked():
send_error(c, "Error 125: Server needs to be locked before write")
return
start = time.time()
# open a temporary file to store the received bytes
try:
file = open("fico/" + filename, 'wb')
except:
os.system("mkdir fico")
file = open("fico/" + filename, 'wb')
byte = 0
# send confirmation
c.send(helper.pad_string("Server is ready to recieve file").encode())
while True:
# receive 1024 bytes at a time and write them to a file
bytes = c.recv(BYTES_TO_SEND)
file.write(bytes)
byte += BYTES_TO_SEND
# break infinite loop once all bytes are transferred
if not bytes:
break
# close the file once transfer is complete
file.close()
# time and space prints
end = time.time()
print("Finished running download of file %s in %.2f seconds" % (filename, float(end - start)))
print(byte, "bytes sent")
def send_file(c, filename):
start = time.time()
# opening a file if possible
try:
f = open("fico/" + filename, 'rb')
except:
send_error(c, "Error 102: File doesn't exist on server machine")
c.close()
return
# send confirmation
print("Server is ready to send file")
c.send(helper.pad_string("Server is ready to send file").encode())
# read bytes and set up counter
l = f.read(BYTES_TO_SEND)
byte = BYTES_TO_SEND
# a forever loop untill file gets sent
while (l):
# send the bytes
c.send(l)
# read more bytes and incrementing counter
l = f.read(BYTES_TO_SEND)
byte += BYTES_TO_SEND
# time and space prints
end = time.time()
print("Finished running download of file in %.2f seconds" % float(end - start))
print(byte, "bytes sent")
time.sleep(0.5)
# Close the connection with the client
c.close()
def send_error(c, errorMessage):
error = helper.pad_string(errorMessage)
c.send(error.encode())
print(error)
def receive_file(filename):
# check if the client is the owner of the file
if not ledger.check_owner(filename, helper.find_ip()):
print("File not owned by this client")
return
# create the downloaded directory if it doesnt exist, and open a file to write in
try:
file = open("directory/" + filename, 'wb')
except:
os.mkdir("directory")
file = open("directory/" + filename, 'wb')
# going through the list of ips and making the request
for index, ip in enumerate(ledger.get_ips_for_file(filename)):
# get the key of the server we want to send the file to
serverPubkey = ledger.get_pubkey(ip)
print(helper.find_ip(), ip)
# check if the current ip in the ledger is the clients
if(ip == helper.find_ip()):
# get the shard name for the file that is stored on the clients computer
shard = ledger.get_shard(filename, ip)
# open the shard to combine it with the rest of the file
tempFile = open("directory/" + shard, 'rb')
# copy the contents of the shard to the new file and decrypt the data
file.write(tempFile.read())
print("here")
# continue iterating through the loop
continue
# connect to the host you want to receive files from
s = run_client(ip)
# gets the shard filename as stored on the host computer
shard = ledger.get_shard(filename, ip)
# create a pull request for the server and encode it to bytes
cmd = helper.pad_string("pull " + shard)
# Encrypt cmd using servers public key
encryptedCmd = encryption.encrypt_using_public_key(cmd.encode(), serverPubkey)
s.send(encryptedCmd)
# recieve confirmation response from server
receivedMessage = s.recv(REQUEST_MAX_LENGTH).decode()
# check if the servor responded with an error
if(receivedMessage.split()[0] != "Error"):
print("Receiving shard from", ip)
while True:
#receive 1024 bytes at a time and decrypt the data
bytes = s.recv(1024)
bytes = encryption.decrypt_using_private_key(bytes)
#write the decrypted data to a file
file.write(bytes)
#break infinite loop once all bytes are transferred
if not bytes:
break
# Server responded with an error
else:
print("Something went wrong while receiving the file.")
# try to remove the original sharded message
try:
os.remove("directory/" + ledger.get_shard(filename, helper.find_ip()))
except:
print("Unable to remove shard from local directory")
#close the file once transfer is complete
file.close()