/
bmproto.py
573 lines (523 loc) · 25.1 KB
/
bmproto.py
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import base64
import hashlib
import random
import socket
import struct
import time
from bmconfigparser import BMConfigParser
from debug import logger
from inventory import Inventory
import knownnodes
from network.advanceddispatcher import AdvancedDispatcher
from network.dandelion import Dandelion
from network.bmobject import BMObject, BMObjectInsufficientPOWError, BMObjectInvalidDataError, \
BMObjectExpiredError, BMObjectUnwantedStreamError, BMObjectInvalidError, BMObjectAlreadyHaveError
import network.connectionpool
from network.node import Node
from network.objectracker import ObjectTracker
from network.proxy import Proxy, ProxyError, GeneralProxyError
import addresses
from queues import objectProcessorQueue, portCheckerQueue, invQueue, addrQueue
import shared
import state
import protocol
import helper_random
class BMProtoError(ProxyError):
errorCodes = ("Protocol error")
class BMProtoInsufficientDataError(BMProtoError):
errorCodes = ("Insufficient data")
class BMProtoExcessiveDataError(BMProtoError):
errorCodes = ("Too much data")
class BMProto(AdvancedDispatcher, ObjectTracker):
# ~1.6 MB which is the maximum possible size of an inv message.
maxMessageSize = 1600100
# 2**18 = 256kB is the maximum size of an object payload
maxObjectPayloadSize = 2**18
# protocol specification says max 1000 addresses in one addr command
maxAddrCount = 1000
# protocol specification says max 50000 objects in one inv command
maxObjectCount = 50000
# address is online if online less than this many seconds ago
addressAlive = 10800
# maximum time offset
maxTimeOffset = 3600
def __init__(self, address=None, sock=None):
AdvancedDispatcher.__init__(self, sock)
self.isOutbound = False
# packet/connection from a local IP
self.local = False
def bm_proto_reset(self):
self.magic = None
self.command = None
self.payloadLength = 0
self.checksum = None
self.payload = None
self.invalid = False
self.payloadOffset = 0
self.expectBytes = protocol.Header.size
self.object = None
def state_bm_header(self):
self.magic, self.command, self.payloadLength, self.checksum = protocol.Header.unpack(self.read_buf[:protocol.Header.size])
self.command = self.command.rstrip('\x00')
if self.magic != 0xE9BEB4D9:
# skip 1 byte in order to sync
self.set_state("bm_header", length=1)
self.bm_proto_reset()
logger.debug("Bad magic")
if self.socket.type == socket.SOCK_STREAM:
self.close_reason = "Bad magic"
self.set_state("close")
return False
if self.payloadLength > BMProto.maxMessageSize:
self.invalid = True
self.set_state("bm_command", length=protocol.Header.size, expectBytes=self.payloadLength)
return True
def state_bm_command(self):
self.payload = self.read_buf[:self.payloadLength]
if self.checksum != hashlib.sha512(self.payload).digest()[0:4]:
logger.debug("Bad checksum, ignoring")
self.invalid = True
retval = True
if not self.fullyEstablished and self.command not in ("error", "version", "verack"):
logger.error("Received command %s before connection was fully established, ignoring", self.command)
self.invalid = True
if not self.invalid:
try:
retval = getattr(self, "bm_command_" + str(self.command).lower())()
except AttributeError:
# unimplemented command
logger.debug("unimplemented command %s", self.command)
except BMProtoInsufficientDataError:
logger.debug("packet length too short, skipping")
except BMProtoExcessiveDataError:
logger.debug("too much data, skipping")
except BMObjectInsufficientPOWError:
logger.debug("insufficient PoW, skipping")
except BMObjectInvalidDataError:
logger.debug("object invalid data, skipping")
except BMObjectExpiredError:
logger.debug("object expired, skipping")
except BMObjectUnwantedStreamError:
logger.debug("object not in wanted stream, skipping")
except BMObjectInvalidError:
logger.debug("object invalid, skipping")
except BMObjectAlreadyHaveError:
logger.debug("%s:%i already got object, skipping", self.destination.host, self.destination.port)
except struct.error:
logger.debug("decoding error, skipping")
elif self.socket.type == socket.SOCK_DGRAM:
# broken read, ignore
pass
else:
#print "Skipping command %s due to invalid data" % (self.command)
logger.debug("Closing due to invalid command %s", self.command)
self.close_reason = "Invalid command %s" % (self.command)
self.set_state("close")
return False
if retval:
self.set_state("bm_header", length=self.payloadLength)
self.bm_proto_reset()
# else assume the command requires a different state to follow
return True
def decode_payload_string(self, length):
value = self.payload[self.payloadOffset:self.payloadOffset+length]
self.payloadOffset += length
return value
def decode_payload_varint(self):
value, offset = addresses.decodeVarint(self.payload[self.payloadOffset:])
self.payloadOffset += offset
return value
def decode_payload_node(self):
services, host, port = self.decode_payload_content("Q16sH")
if host[0:12] == '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xFF\xFF':
host = socket.inet_ntop(socket.AF_INET, str(host[12:16]))
elif host[0:6] == '\xfd\x87\xd8\x7e\xeb\x43':
# Onion, based on BMD/bitcoind
host = base64.b32encode(host[6:]).lower() + ".onion"
else:
host = socket.inet_ntop(socket.AF_INET6, str(host))
if host == "":
# This can happen on Windows systems which are not 64-bit compatible
# so let us drop the IPv6 address.
host = socket.inet_ntop(socket.AF_INET, str(host[12:16]))
return Node(services, host, port)
def decode_payload_content(self, pattern = "v"):
# L = varint indicating the length of the next array
# l = varint indicating the length of the next item
# v = varint (or array)
# H = uint16
# I = uint32
# Q = uint64
# i = net_addr (without time and stream number)
# s = string
# 0-9 = length of the next item
# , = end of array
def decode_simple(self, char="v"):
if char == "v":
return self.decode_payload_varint()
if char == "i":
return self.decode_payload_node()
if char == "H":
self.payloadOffset += 2
return struct.unpack(">H", self.payload[self.payloadOffset-2:self.payloadOffset])[0]
if char == "I":
self.payloadOffset += 4
return struct.unpack(">I", self.payload[self.payloadOffset-4:self.payloadOffset])[0]
if char == "Q":
self.payloadOffset += 8
return struct.unpack(">Q", self.payload[self.payloadOffset-8:self.payloadOffset])[0]
size = None
isArray = False
# size
# iterator starting from size counting to 0
# isArray?
# subpattern
# position of parser in subpattern
# retval (array)
parserStack = [[1, 1, False, pattern, 0, []]]
#try:
# sys._getframe(200)
# logger.error("Stack depth warning, pattern: %s", pattern)
# return
#except ValueError:
# pass
while True:
i = parserStack[-1][3][parserStack[-1][4]]
if i in "0123456789" and (size is None or parserStack[-1][3][parserStack[-1][4]-1] not in "lL"):
try:
size = size * 10 + int(i)
except TypeError:
size = int(i)
isArray = False
elif i in "Ll" and size is None:
size = self.decode_payload_varint()
if i == "L":
isArray = True
else:
isArray = False
elif size is not None:
if isArray:
parserStack.append([size, size, isArray, parserStack[-1][3][parserStack[-1][4]:], 0, []])
parserStack[-2][4] = len(parserStack[-2][3])
else:
for j in range(parserStack[-1][4], len(parserStack[-1][3])):
if parserStack[-1][3][j] not in "lL0123456789":
break
parserStack.append([size, size, isArray, parserStack[-1][3][parserStack[-1][4]:j+1], 0, []])
parserStack[-2][4] += len(parserStack[-1][3]) - 1
size = None
continue
elif i == "s":
#if parserStack[-2][2]:
# parserStack[-1][5].append(self.payload[self.payloadOffset:self.payloadOffset + parserStack[-1][0]])
#else:
parserStack[-1][5] = self.payload[self.payloadOffset:self.payloadOffset + parserStack[-1][0]]
self.payloadOffset += parserStack[-1][0]
parserStack[-1][1] = 0
parserStack[-1][2] = True
#del parserStack[-1]
size = None
elif i in "viHIQ":
parserStack[-1][5].append(decode_simple(self, parserStack[-1][3][parserStack[-1][4]]))
size = None
else:
size = None
for depth in range(len(parserStack) - 1, -1, -1):
parserStack[depth][4] += 1
if parserStack[depth][4] >= len(parserStack[depth][3]):
parserStack[depth][1] -= 1
parserStack[depth][4] = 0
if depth > 0:
if parserStack[depth][2]:
parserStack[depth - 1][5].append(parserStack[depth][5])
else:
parserStack[depth - 1][5].extend(parserStack[depth][5])
parserStack[depth][5] = []
if parserStack[depth][1] <= 0:
if depth == 0:
# we're done, at depth 0 counter is at 0 and pattern is done parsing
return parserStack[depth][5]
del parserStack[-1]
continue
break
break
if self.payloadOffset > self.payloadLength:
logger.debug("Insufficient data %i/%i", self.payloadOffset, self.payloadLength)
raise BMProtoInsufficientDataError()
def bm_command_error(self):
fatalStatus, banTime, inventoryVector, errorText = self.decode_payload_content("vvlsls")
logger.error("%s:%i error: %i, %s", self.destination.host, self.destination.port, fatalStatus, errorText)
return True
def bm_command_getdata(self):
items = self.decode_payload_content("l32s")
# skip?
if time.time() < self.skipUntil:
return True
#TODO make this more asynchronous
helper_random.randomshuffle(items)
for i in map(str, items):
if Dandelion().hasHash(i) and \
self != Dandelion().objectChildStem(i):
self.antiIntersectionDelay()
logger.info('%s asked for a stem object we didn\'t offer to it.', self.destination)
break
else:
try:
self.append_write_buf(protocol.CreatePacket('object', Inventory()[i].payload))
except KeyError:
self.antiIntersectionDelay()
logger.info('%s asked for an object we don\'t have.', self.destination)
break
# I think that aborting after the first missing/stem object is more secure
# when using random reordering, as the recipient won't know exactly which objects we refuse to deliver
return True
def _command_inv(self, dandelion=False):
items = self.decode_payload_content("l32s")
if len(items) >= BMProto.maxObjectCount:
logger.error("Too many items in %sinv message!", "d" if dandelion else "")
raise BMProtoExcessiveDataError()
else:
pass
# ignore dinv if dandelion turned off
if dandelion and not state.dandelion:
return True
for i in map(str, items):
if i in Inventory() and not Dandelion().hasHash(i):
continue
if dandelion and not Dandelion().hasHash(i):
Dandelion().addHash(i, self)
self.handleReceivedInventory(i)
return True
def bm_command_inv(self):
return self._command_inv(False)
def bm_command_dinv(self):
"""
Dandelion stem announce
"""
return self._command_inv(True)
def bm_command_object(self):
objectOffset = self.payloadOffset
nonce, expiresTime, objectType, version, streamNumber = self.decode_payload_content("QQIvv")
self.object = BMObject(nonce, expiresTime, objectType, version, streamNumber, self.payload, self.payloadOffset)
if len(self.payload) - self.payloadOffset > BMProto.maxObjectPayloadSize:
logger.info('The payload length of this object is too large (%s bytes). Ignoring it.' % len(self.payload) - self.payloadOffset)
raise BMProtoExcessiveDataError()
try:
self.object.checkProofOfWorkSufficient()
self.object.checkEOLSanity()
self.object.checkAlreadyHave()
except (BMObjectExpiredError, BMObjectAlreadyHaveError, BMObjectInsufficientPOWError) as e:
BMProto.stopDownloadingObject(self.object.inventoryHash)
raise e
try:
self.object.checkStream()
except (BMObjectUnwantedStreamError,) as e:
BMProto.stopDownloadingObject(self.object.inventoryHash, BMConfigParser().get("inventory", "acceptmismatch"))
if not BMConfigParser().get("inventory", "acceptmismatch"):
raise e
try:
self.object.checkObjectByType()
objectProcessorQueue.put((self.object.objectType, buffer(self.object.data)))
except BMObjectInvalidError as e:
BMProto.stopDownloadingObject(self.object.inventoryHash, True)
else:
try:
del state.missingObjects[self.object.inventoryHash]
except KeyError:
pass
if self.object.inventoryHash in Inventory() and Dandelion().hasHash(self.object.inventoryHash):
Dandelion().removeHash(self.object.inventoryHash, "cycle detection")
Inventory()[self.object.inventoryHash] = (
self.object.objectType, self.object.streamNumber, buffer(self.payload[objectOffset:]), self.object.expiresTime, buffer(self.object.tag))
self.handleReceivedObject(self.object.streamNumber, self.object.inventoryHash)
invQueue.put((self.object.streamNumber, self.object.inventoryHash, self.destination))
return True
def _decode_addr(self):
return self.decode_payload_content("LQIQ16sH")
def bm_command_addr(self):
addresses = self._decode_addr()
for i in addresses:
seenTime, stream, services, ip, port = i
decodedIP = protocol.checkIPAddress(str(ip))
if stream not in state.streamsInWhichIAmParticipating:
continue
if decodedIP is not False and seenTime > time.time() - BMProto.addressAlive:
peer = state.Peer(decodedIP, port)
try:
if knownnodes.knownNodes[stream][peer]["lastseen"] > seenTime:
continue
except KeyError:
pass
if len(knownnodes.knownNodes[stream]) < int(BMConfigParser().get("knownnodes", "maxnodes")):
with knownnodes.knownNodesLock:
try:
knownnodes.knownNodes[stream][peer]["lastseen"] = seenTime
except (TypeError, KeyError):
knownnodes.knownNodes[stream][peer] = {
"lastseen": seenTime,
"rating": 0,
"self": False,
}
addrQueue.put((stream, peer, self.destination))
return True
def bm_command_portcheck(self):
portCheckerQueue.put(state.Peer(self.destination, self.peerNode.port))
return True
def bm_command_ping(self):
self.append_write_buf(protocol.CreatePacket('pong'))
return True
def bm_command_pong(self):
# nothing really
return True
def bm_command_verack(self):
self.verackReceived = True
if self.verackSent:
if self.isSSL:
self.set_state("tls_init", length=self.payloadLength, expectBytes=0)
return False
self.set_state("connection_fully_established", length=self.payloadLength, expectBytes=0)
return False
return True
def bm_command_version(self):
self.remoteProtocolVersion, self.services, self.timestamp, self.sockNode, self.peerNode, self.nonce, \
self.userAgent, self.streams = self.decode_payload_content("IQQiiQlsLv")
self.nonce = struct.pack('>Q', self.nonce)
self.timeOffset = self.timestamp - int(time.time())
logger.debug("remoteProtocolVersion: %i", self.remoteProtocolVersion)
logger.debug("services: 0x%08X", self.services)
logger.debug("time offset: %i", self.timestamp - int(time.time()))
logger.debug("my external IP: %s", self.sockNode.host)
logger.debug("remote node incoming address: %s:%i", self.destination.host, self.peerNode.port)
logger.debug("user agent: %s", self.userAgent)
logger.debug("streams: [%s]", ",".join(map(str,self.streams)))
if not self.peerValidityChecks():
# TODO ABORT
return True
#shared.connectedHostsList[self.destination] = self.streams[0]
self.append_write_buf(protocol.CreatePacket('verack'))
self.verackSent = True
if not self.isOutbound:
self.append_write_buf(protocol.assembleVersionMessage(self.destination.host, self.destination.port, \
network.connectionpool.BMConnectionPool().streams, True, nodeid=self.nodeid))
#print "%s:%i: Sending version" % (self.destination.host, self.destination.port)
if ((self.services & protocol.NODE_SSL == protocol.NODE_SSL) and
protocol.haveSSL(not self.isOutbound)):
self.isSSL = True
if self.verackReceived:
if self.isSSL:
self.set_state("tls_init", length=self.payloadLength, expectBytes=0)
return False
self.set_state("connection_fully_established", length=self.payloadLength, expectBytes=0)
return False
return True
def peerValidityChecks(self):
if self.remoteProtocolVersion < 3:
self.append_write_buf(protocol.assembleErrorMessage(fatal=2,
errorText="Your is using an old protocol. Closing connection."))
logger.debug ('Closing connection to old protocol version %s, node: %s',
str(self.remoteProtocolVersion), str(self.destination))
return False
if self.timeOffset > BMProto.maxTimeOffset:
self.append_write_buf(protocol.assembleErrorMessage(fatal=2,
errorText="Your time is too far in the future compared to mine. Closing connection."))
logger.info("%s's time is too far in the future (%s seconds). Closing connection to it.",
self.destination, self.timeOffset)
shared.timeOffsetWrongCount += 1
return False
elif self.timeOffset < -BMProto.maxTimeOffset:
self.append_write_buf(protocol.assembleErrorMessage(fatal=2,
errorText="Your time is too far in the past compared to mine. Closing connection."))
logger.info("%s's time is too far in the past (timeOffset %s seconds). Closing connection to it.",
self.destination, self.timeOffset)
shared.timeOffsetWrongCount += 1
return False
else:
shared.timeOffsetWrongCount = 0
if not self.streams:
self.append_write_buf(protocol.assembleErrorMessage(fatal=2,
errorText="We don't have shared stream interests. Closing connection."))
logger.debug ('Closed connection to %s because there is no overlapping interest in streams.',
str(self.destination))
return False
if self.destination in network.connectionpool.BMConnectionPool().inboundConnections:
try:
if not protocol.checkSocksIP(self.destination.host):
self.append_write_buf(protocol.assembleErrorMessage(fatal=2,
errorText="Too many connections from your IP. Closing connection."))
logger.debug ('Closed connection to %s because we are already connected to that IP.',
str(self.destination))
return False
except:
pass
if not self.isOutbound:
# incoming from a peer we're connected to as outbound, or server full
# report the same error to counter deanonymisation
if state.Peer(self.destination.host, self.peerNode.port) in \
network.connectionpool.BMConnectionPool().inboundConnections or \
len(network.connectionpool.BMConnectionPool().inboundConnections) + \
len(network.connectionpool.BMConnectionPool().outboundConnections) > \
BMConfigParser().safeGetInt("bitmessagesettings", "maxtotalconnections") + \
BMConfigParser().safeGetInt("bitmessagesettings", "maxbootstrapconnections"):
self.append_write_buf(protocol.assembleErrorMessage(fatal=2,
errorText="Server full, please try again later."))
logger.debug ("Closed connection to %s due to server full or duplicate inbound/outbound.",
str(self.destination))
return False
if network.connectionpool.BMConnectionPool().isAlreadyConnected(self.nonce):
self.append_write_buf(protocol.assembleErrorMessage(fatal=2,
errorText="I'm connected to myself. Closing connection."))
logger.debug ("Closed connection to %s because I'm connected to myself.",
str(self.destination))
return False
return True
@staticmethod
def assembleAddr(peerList):
if isinstance(peerList, state.Peer):
peerList = (peerList)
if not peerList:
return b''
retval = b''
for i in range(0, len(peerList), BMProto.maxAddrCount):
payload = addresses.encodeVarint(len(peerList[i:i + BMProto.maxAddrCount]))
for address in peerList[i:i + BMProto.maxAddrCount]:
stream, peer, timestamp = address
payload += struct.pack(
'>Q', timestamp) # 64-bit time
payload += struct.pack('>I', stream)
payload += struct.pack(
'>q', 1) # service bit flags offered by this node
payload += protocol.encodeHost(peer.host)
payload += struct.pack('>H', peer.port) # remote port
retval += protocol.CreatePacket('addr', payload)
return retval
@staticmethod
def stopDownloadingObject(hashId, forwardAnyway=False):
for connection in network.connectionpool.BMConnectionPool().inboundConnections.values() + \
network.connectionpool.BMConnectionPool().outboundConnections.values():
try:
del connection.objectsNewToMe[hashId]
except KeyError:
pass
if not forwardAnyway:
try:
with connection.objectsNewToThemLock:
del connection.objectsNewToThem[hashId]
except KeyError:
pass
try:
del state.missingObjects[hashId]
except KeyError:
pass
def handle_close(self):
self.set_state("close")
if not (self.accepting or self.connecting or self.connected):
# already disconnected
return
try:
logger.debug("%s:%i: closing, %s", self.destination.host, self.destination.port, self.close_reason)
except AttributeError:
try:
logger.debug("%s:%i: closing", self.destination.host, self.destination.port)
except AttributeError:
logger.debug("Disconnected socket closing")
AdvancedDispatcher.handle_close(self)