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PyBitmessage
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Refactor packet header extraction and generation

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Demote payloadLength from class instance variable to processData local variable as no other function was using it
Improve processData:
 -Utilise shared.Header
 -Use a memoryview to reduce memory overhead
 -Clean up variables before a recursive call
 -Strip null bytes from command
Refactor sendData
Various functions:
 -Use shared.CreatePacket to generate packets
Fix typo in _checkIPv4Address
master
bmng-dev 9 years ago
parent ccfbe8da47
commit 0f9625aac7
1 changed files with 66 additions and 84 deletions
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150
src/class_receiveDataThread.py
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@ -47,7 +47,6 @@ class receiveDataThread(threading.Thread):
self.sock = sock
self.peer = shared.Peer(HOST, port)
self.streamNumber = streamNumber
self.payloadLength = 0 # This is the protocol payload length thus it doesn't include the 24 byte message header
self.objectsThatWeHaveYetToGetFromThisPeer = {}
self.selfInitiatedConnections = selfInitiatedConnections
self.sendDataThreadQueue = sendDataThreadQueue # used to send commands and data to the sendDataThread
@ -113,28 +112,39 @@ class receiveDataThread(threading.Thread):
# with shared.printLock:
# print 'self.data is currently ', repr(self.data)
#
if len(self.data) < 24: # if so little of the data has arrived that we can't even read the checksum then wait for more data.
if len(self.data) < shared.Header.size: # if so little of the data has arrived that we can't even read the checksum then wait for more data.
return
if self.data[0:4] != '\xe9\xbe\xb4\xd9':
#Use a memoryview so we don't copy data unnecessarily
view = memoryview(self.data)
magic,command,payloadLength,checksum = shared.Header.unpack(view[:shared.Header.size])
view = view[shared.Header.size:]
if magic != 0xE9BEB4D9:
#if shared.verbose >= 1:
# with shared.printLock:
# print 'The magic bytes were not correct. First 40 bytes of data: ' + repr(self.data[0:40])
self.data = ""
return
self.payloadLength, = unpack('>L', self.data[16:20])
if self.payloadLength > 20000000:
logger.info('The incoming message, which we have not yet download, is too large. Ignoring it. (unfortunately there is no way to tell the other node to stop sending it except to disconnect.) Message size: %s' % self.payloadLength)
self.data = self.data[self.payloadLength + 24:]
if payloadLength > 20000000:
logger.info('The incoming message, which we have not yet download, is too large. Ignoring it. (unfortunately there is no way to tell the other node to stop sending it except to disconnect.) Message size: %s' % payloadLength)
self.data = view[payloadLength:].tobytes()
del view,magic,command,payloadLength,checksum #we don't need these anymore and better to clean them now before the recursive call rather than after
self.processData()
return
if len(self.data) < self.payloadLength + 24: # check if the whole message has arrived yet.
if len(view) < payloadLength: # check if the whole message has arrived yet.
return
if self.data[20:24] != hashlib.sha512(self.data[24:self.payloadLength + 24]).digest()[0:4]: # test the checksum in the message. If it is correct...
payload = view[:payloadLength]
if checksum != hashlib.sha512(payload).digest()[0:4]: # test the checksum in the message. If it is correct...
print 'Checksum incorrect. Clearing this message.'
self.data = self.data[self.payloadLength + 24:]
self.data = view[payloadLength:].tobytes()
del view,magic,command,payloadLength,checksum,payload #again better to clean up before the recursive call
self.processData()
return
#We can now revert back to bytestrings and take this message out
payload = payload.tobytes()
self.data = view[payloadLength:].tobytes()
del view,magic,payloadLength,checksum
# The time we've last seen this node is obviously right now since we
# just received valid data from it. So update the knownNodes list so
# that other peers can be made aware of its existance.
@ -143,37 +153,39 @@ class receiveDataThread(threading.Thread):
shared.knownNodes[self.streamNumber][self.peer] = int(time.time())
shared.knownNodesLock.release()
remoteCommand = self.data[4:16]
#Strip the nulls
command = command.rstrip('\x00')
with shared.printLock:
print 'remoteCommand', repr(remoteCommand.replace('\x00', '')), ' from', self.peer
if remoteCommand == 'version\x00\x00\x00\x00\x00' and not self.connectionIsOrWasFullyEstablished:
self.recversion(self.data[24:self.payloadLength + 24])
elif remoteCommand == 'verack\x00\x00\x00\x00\x00\x00' and not self.connectionIsOrWasFullyEstablished:
self.recverack()
elif remoteCommand == 'addr\x00\x00\x00\x00\x00\x00\x00\x00' and self.connectionIsOrWasFullyEstablished:
self.recaddr(self.data[24:self.payloadLength + 24])
elif remoteCommand == 'getpubkey\x00\x00\x00' and self.connectionIsOrWasFullyEstablished:
shared.checkAndSharegetpubkeyWithPeers(self.data[24:self.payloadLength + 24])
elif remoteCommand == 'pubkey\x00\x00\x00\x00\x00\x00' and self.connectionIsOrWasFullyEstablished:
self.recpubkey(self.data[24:self.payloadLength + 24])
elif remoteCommand == 'inv\x00\x00\x00\x00\x00\x00\x00\x00\x00' and self.connectionIsOrWasFullyEstablished:
self.recinv(self.data[24:self.payloadLength + 24])
elif remoteCommand == 'getdata\x00\x00\x00\x00\x00' and self.connectionIsOrWasFullyEstablished:
self.recgetdata(self.data[24:self.payloadLength + 24])
elif remoteCommand == 'msg\x00\x00\x00\x00\x00\x00\x00\x00\x00' and self.connectionIsOrWasFullyEstablished:
self.recmsg(self.data[24:self.payloadLength + 24])
elif remoteCommand == 'broadcast\x00\x00\x00' and self.connectionIsOrWasFullyEstablished:
self.recbroadcast(self.data[24:self.payloadLength + 24])
elif remoteCommand == 'ping\x00\x00\x00\x00\x00\x00\x00\x00' and self.connectionIsOrWasFullyEstablished:
self.sendpong()
elif remoteCommand == 'pong\x00\x00\x00\x00\x00\x00\x00\x00' and self.connectionIsOrWasFullyEstablished:
pass
elif remoteCommand == 'alert\x00\x00\x00\x00\x00\x00\x00' and self.connectionIsOrWasFullyEstablished:
pass
print 'remoteCommand', repr(command), ' from', self.peer
#TODO: Use a dispatcher here
if not self.connectionIsOrWasFullyEstablished:
if command == 'version':
self.recversion(payload)
elif command == 'verack':
self.recverack()
else:
if command == 'addr':
self.recaddr(payload)
elif command == 'getpubkey':
shared.checkAndSharegetpubkeyWithPeers(payload)
elif command == 'pubkey':
self.recpubkey(payload)
elif command == 'inv':
self.recinv(payload)
elif command == 'getdata':
self.recgetdata(payload)
elif command == 'msg':
self.recmsg(payload)
elif command == 'broadcast':
self.recbroadcast(payload)
elif command == 'ping':
self.sendpong(payload)
#elif command == 'pong':
# pass
#elif command == 'alert':
# pass
self.data = self.data[
self.payloadLength + 24:] # take this message out and then process the next message
if self.data == '':
while len(self.objectsThatWeHaveYetToGetFromThisPeer) > 0:
shared.numberOfInventoryLookupsPerformed += 1
@ -226,7 +238,7 @@ class receiveDataThread(threading.Thread):
def sendpong(self):
print 'Sending pong'
self.sendDataThreadQueue.put((0, 'sendRawData', '\xE9\xBE\xB4\xD9\x70\x6F\x6E\x67\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xcf\x83\xe1\x35'))
self.sendDataThreadQueue.put((0, 'sendRawData', shared.CreatePacket('pong')))
def recverack(self):
@ -297,7 +309,7 @@ class receiveDataThread(threading.Thread):
for hash, storedValue in bigInvList.items():
payload += hash
numberOfObjectsInInvMessage += 1
if numberOfObjectsInInvMessage >= 50000: # We can only send a max of 50000 items per inv message but we may have more objects to advertise. They must be split up into multiple inv messages.
if numberOfObjectsInInvMessage == 50000: # We can only send a max of 50000 items per inv message but we may have more objects to advertise. They must be split up into multiple inv messages.
self.sendinvMessageToJustThisOnePeer(
numberOfObjectsInInvMessage, payload)
payload = ''
@ -311,13 +323,9 @@ class receiveDataThread(threading.Thread):
# function for broadcasting invs to everyone in our stream.
def sendinvMessageToJustThisOnePeer(self, numberOfObjects, payload):
payload = encodeVarint(numberOfObjects) + payload
headerData = '\xe9\xbe\xb4\xd9' # magic bits, slighly different from Bitcoin's magic bits.
headerData += 'inv\x00\x00\x00\x00\x00\x00\x00\x00\x00'
headerData += pack('>L', len(payload))
headerData += hashlib.sha512(payload).digest()[:4]
with shared.printLock:
print 'Sending huge inv message with', numberOfObjects, 'objects to just this one peer'
self.sendDataThreadQueue.put((0, 'sendRawData', headerData + payload))
self.sendDataThreadQueue.put((0, 'sendRawData', shared.CreatePacket('inv', payload)))
def _sleepForTimingAttackMitigation(self, sleepTime):
# We don't need to do the timing attack mitigation if we are
@ -457,12 +465,7 @@ class receiveDataThread(threading.Thread):
print 'sending getdata to retrieve object with hash:', hash.encode('hex')
payload = '\x01' + hash
headerData = '\xe9\xbe\xb4\xd9' # magic bits, slighly different from Bitcoin's magic bits.
headerData += 'getdata\x00\x00\x00\x00\x00'
headerData += pack('>L', len(
payload)) # payload length. Note that we add an extra 8 for the nonce.
headerData += hashlib.sha512(payload).digest()[:4]
self.sendDataThreadQueue.put((0, 'sendRawData', headerData + payload))
self.sendDataThreadQueue.put((0, 'sendRawData', shared.CreatePacket('getdata', payload)))
# We have received a getdata request from our peer
@ -499,34 +502,17 @@ class receiveDataThread(threading.Thread):
# Our peer has requested (in a getdata message) that we send an object.
def sendData(self, objectType, payload):
headerData = '\xe9\xbe\xb4\xd9' # magic bits, slighly different from Bitcoin's magic bits.
if objectType == 'pubkey':
with shared.printLock:
print 'sending pubkey'
headerData += 'pubkey\x00\x00\x00\x00\x00\x00'
elif objectType == 'getpubkey' or objectType == 'pubkeyrequest':
with shared.printLock:
print 'sending getpubkey'
headerData += 'getpubkey\x00\x00\x00'
elif objectType == 'msg':
with shared.printLock:
print 'sending msg'
headerData += 'msg\x00\x00\x00\x00\x00\x00\x00\x00\x00'
elif objectType == 'broadcast':
with shared.printLock:
print 'sending broadcast'
headerData += 'broadcast\x00\x00\x00'
else:
# pubkeyrequest??
if objectType == 'pubkeyrequest':
objectType = 'getpubkey'
elif objectType != 'pubkey' and objectType != 'getpubkey' and
objectType != 'msg' and objectType != 'broadcast':
sys.stderr.write(
'Error: sendData has been asked to send a strange objectType: %s\n' % str(objectType))
return
headerData += pack('>L', len(payload)) # payload length.
headerData += hashlib.sha512(payload).digest()[:4]
self.sendDataThreadQueue.put((0, 'sendRawData', headerData + payload))
with shared.printLock:
print 'sending', objectType
self.sendDataThreadQueue.put((0, 'sendRawData', shared.CreatePacket(objectType, payload)))
# Advertise this object to all of our peers
@ -545,7 +531,7 @@ class receiveDataThread(threading.Thread):
if host[0] == '\x0A':
print 'Ignoring IP address in private range:', hostFromAddrMessage
return False
if host[0:2] == '\xC0A8':
if host[0:2] == '\xC0\xA8':
print 'Ignoring IP address in private range:', hostFromAddrMessage
return False
return True
@ -745,11 +731,7 @@ class receiveDataThread(threading.Thread):
payload += pack('>H', PORT) # remote port
payload = encodeVarint(numberOfAddressesInAddrMessage) + payload
datatosend = '\xE9\xBE\xB4\xD9addr\x00\x00\x00\x00\x00\x00\x00\x00'
datatosend = datatosend + pack('>L', len(payload)) # payload length
datatosend = datatosend + hashlib.sha512(payload).digest()[0:4]
datatosend = datatosend + payload
self.sendDataThreadQueue.put((0, 'sendRawData', datatosend))
self.sendDataThreadQueue.put((0, 'sendRawData', shared.CreatePacket('addr', payload)))
# We have received a version message
@ -832,7 +814,7 @@ class receiveDataThread(threading.Thread):
def sendverack(self):
with shared.printLock:
print 'Sending verack'
self.sendDataThreadQueue.put((0, 'sendRawData', '\xE9\xBE\xB4\xD9\x76\x65\x72\x61\x63\x6B\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xcf\x83\xe1\x35'))
self.sendDataThreadQueue.put((0, 'sendRawData', shared.CreatePacket('verack')))
self.verackSent = True
if self.verackReceived:
self.connectionFullyEstablished()

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