Dandelion++ implementation

- untested, some functionality may be missing, don't turn on
- also, it randomises upload of requested objects
- affects #1049

src/bitmessagemain.py

@@ -54,6 +54,7 @@ from bmconfigparser import BMConfigParser
 from inventory import Inventory
 
 from network.connectionpool import BMConnectionPool
+from network.dandelion import DandelionStems
 from network.networkthread import BMNetworkThread
 from network.receivequeuethread import ReceiveQueueThread
 from network.announcethread import AnnounceThread
@@ -248,6 +249,7 @@ class Main:
         sqlLookup.start()
 
         Inventory() # init
+        DandelionStems() # init, needs to be early because other thread may access it early
 
         # SMTP delivery thread
         if daemon and BMConfigParser().safeGet("bitmessagesettings", "smtpdeliver", '') != '':

src/bmconfigparser.py

@@ -20,6 +20,7 @@ BMConfigDefaults = {
     },
     "network": {
         "bind": '',
+        "dandelion": 0,
     },
     "inventory": {
         "storage": "sqlite",

src/class_singleCleaner.py

@@ -10,6 +10,7 @@ from helper_sql import *
 from helper_threading import *
 from inventory import Inventory
 from network.connectionpool import BMConnectionPool
+from network.dandelion import DandelionStems
 from debug import logger
 import knownnodes
 import queues
@@ -126,6 +127,10 @@ class singleCleaner(threading.Thread, StoppableThread):
             # inv/object tracking
             for connection in BMConnectionPool().inboundConnections.values() + BMConnectionPool().outboundConnections.values():
                 connection.clean()
+            # dandelion fluff trigger by expiration
+            for h, t in DandelionStems().timeouts:
+                if time.time() > t:
+                    DandelionStems().remove(h)
 
             # discovery tracking
             exp = time.time() - singleCleaner.expireDiscoveredPeers

src/network/bmobject.py

@@ -4,6 +4,7 @@ import time
 from addresses import calculateInventoryHash
 from debug import logger
 from inventory import Inventory
+from network.dandelion import DandelionStems
 import protocol
 import state
 
@@ -66,6 +67,9 @@ class BMObject(object):
             raise BMObjectUnwantedStreamError()
 
     def checkAlreadyHave(self):
+        # if it's a stem duplicate, pretend we don't have it
+        if self.inventoryHash in DandelionStems().stem:
+            return
         if self.inventoryHash in Inventory():
             raise BMObjectAlreadyHaveError()
 

src/network/bmproto.py

@@ -1,6 +1,7 @@
 import base64
 import hashlib
 import time
+import random
 import socket
 import struct
 
@@ -9,6 +10,7 @@ from debug import logger
 from inventory import Inventory
 import knownnodes
 from network.advanceddispatcher import AdvancedDispatcher
+from network.dandelion import DandelionStems, REASSIGN_INTERVAL
 from network.bmobject import BMObject, BMObjectInsufficientPOWError, BMObjectInvalidDataError, \
         BMObjectExpiredError, BMObjectUnwantedStreamError, BMObjectInvalidError, BMObjectAlreadyHaveError
 import network.connectionpool
@@ -61,6 +63,8 @@ class BMProto(AdvancedDispatcher, ObjectTracker):
         self.payloadOffset = 0
         self.expectBytes = protocol.Header.size
         self.object = None
+        self.dandelionRoutes = []
+        self.dandelionRefresh = 0
 
     def state_bm_header(self):
         self.magic, self.command, self.payloadLength, self.checksum = protocol.Header.unpack(self.read_buf[:protocol.Header.size])
@@ -266,13 +270,23 @@ class BMProto(AdvancedDispatcher, ObjectTracker):
         # skip?
         if time.time() < self.skipUntil:
             return True
-        #TODO make this more asynchronous and allow reordering
+        #TODO make this more asynchronous
+        random.shuffle(items)
         for i in items:
+            if i in DandelionStems().stem and \
+                    self not in DandelionStems().stem[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 bm_command_inv(self):
@@ -289,6 +303,34 @@ class BMProto(AdvancedDispatcher, ObjectTracker):
 
         return True
 
+    def bm_command_dinv(self):
+        """
+        Dandelion stem announce
+        """
+        items = self.decode_payload_content("l32s")
+
+        if len(items) >= BMProto.maxObjectCount:
+            logger.error("Too many items in dinv message!")
+            raise BMProtoExcessiveDataError()
+        else:
+            pass
+
+        # ignore command if dandelion turned off
+        if BMConfigParser().safeGetBoolean("network", "dandelion") == 0:
+            return True
+
+        if self.dandelionRefresh < time.time():
+            self.dandelionRoutes = network.connectionpool.dandelionRouteSelector(self)
+            self.dandelionRefresh = time.time() + REASSIGN_INTERVAL
+
+        for i in items:
+            # Fluff trigger by RNG, per item
+            if random.randint(1, 100) < BMConfigParser().safeGetBoolean("network", "dandelion"):
+                DandelionStem().add(i, self.dandelionRoutes)
+            self.handleReceivedInventory(i)
+
+        return True
+
     def bm_command_object(self):
         objectOffset = self.payloadOffset
         nonce, expiresTime, objectType, version, streamNumber = self.decode_payload_content("QQIvv")

src/network/connectionpool.py

@@ -51,6 +51,22 @@ class BMConnectionPool(object):
                 except KeyError:
                     pass
 
+    def dandelionRouteSelector(node):
+        # Choose 2 peers randomly
+        # TODO: handle streams
+        peers = []
+        connections = BMConnectionPool().inboundConnections.values() + \
+                BMConnectionPool().outboundConnections.values()
+        random.shuffle(connections)
+        for i in connections:
+            if i == node:
+                continue
+            if i.services | protocol.NODE_DANDELION:
+                peers.append(i)
+                if len(peers) == 2:
+                    break
+        return peers
+
     def connectToStream(self, streamNumber):
         self.streams.append(streamNumber)
 

src/network/dandelion.py

@@ -0,0 +1,29 @@
+import random
+from threading import RLock
+
+import protocol
+from singleton import Singleton
+
+# randomise routes after 600 seconds
+REASSIGN_INTERVAL = 600
+FLUFF_TRIGGER_TIMEOUT = 300
+
+@Singleton
+class DandelionStems():
+    def __init__(self):
+        self.stem = {}
+        self.timeouts = {}
+        self.lock = RLock()
+
+    def add(self, hashId, stems):
+        with self.lock:
+            self.stem[hashId] = stems
+            self.timeouts[hashId] = time.time()
+
+    def remove(self, hashId):
+        with self.lock:
+            try:
+                del self.stem[hashId]
+                del self.timeouts[hashId]
+            except KeyError:
+                pass

src/network/invthread.py

@@ -4,6 +4,7 @@ import threading
 import addresses
 from helper_threading import StoppableThread
 from network.connectionpool import BMConnectionPool
+from network.dandelion import DandelionStems
 from queues import invQueue
 import protocol
 import state
@@ -39,6 +40,8 @@ class InvThread(threading.Thread, StoppableThread):
                     for inv in chunk:
                         if inv[0] not in connection.streams:
                             continue
+                        if inv in DandelionStems().stem and connection not in DandelionStems().stem[inv]:
+                            continue
                         try:
                             with connection.objectsNewToThemLock:
                                 del connection.objectsNewToThem[inv[1]]

src/network/objectracker.py

@@ -4,6 +4,7 @@ from threading import RLock
 
 from debug import logger
 from inventory import Inventory
+from network.dandelion import DandelionStems
 
 haveBloom = False
 
@@ -83,6 +84,11 @@ class ObjectTracker(object):
         if hashId not in Inventory():
             with self.objectsNewToMeLock:
                 self.objectsNewToMe[hashId] = True
+        elif hashId in DandelionStems().stem:
+            # Fluff trigger by cycle detection
+            DandelionStems().remove(hashId)
+            with self.objectsNewToMeLock:
+                self.objectsNewToMe[hashId] = True
 
     def hasAddr(self, addr):
         if haveBloom:

src/network/tcp.py

@@ -18,6 +18,7 @@ from network.advanceddispatcher import AdvancedDispatcher
 from network.bmproto import BMProtoError, BMProtoInsufficientDataError, BMProtoExcessiveDataError, BMProto
 from network.bmobject import BMObject, BMObjectInsufficientPOWError, BMObjectInvalidDataError, BMObjectExpiredError, BMObjectUnwantedStreamError, BMObjectInvalidError, BMObjectAlreadyHaveError
 import network.connectionpool
+from network.dandelion import DandelionStems
 from network.node import Node
 import network.asyncore_pollchoose as asyncore
 from network.proxy import Proxy, ProxyError, GeneralProxyError
@@ -88,7 +89,7 @@ class TCPConnection(BMProto, TLSDispatcher):
                 if self.skipUntil > time.time():
                     logger.debug("Initial skipping processing getdata for %.2fs", self.skipUntil - time.time())
             else:
-                logger.debug("Skipping processing getdata due to missing object for %.2fs", self.skipUntil - time.time())
+                logger.debug("Skipping processing getdata due to missing object for %.2fs", delay)
                 self.skipUntil = time.time() + delay
 
     def state_connection_fully_established(self):
@@ -165,6 +166,9 @@ class TCPConnection(BMProto, TLSDispatcher):
             # may lock for a long time, but I think it's better than thousands of small locks
             with self.objectsNewToThemLock:
                 for objHash in Inventory().unexpired_hashes_by_stream(stream):
+                    # don't advertise stem objects on bigInv
+                    if objHash in DandelionStems().stem:
+                        continue
                     bigInvList[objHash] = 0
                     self.objectsNewToThem[objHash] = time.time()
         objectCount = 0

src/protocol.py

@@ -23,6 +23,7 @@ from version import softwareVersion
 #Service flags
 NODE_NETWORK = 1
 NODE_SSL = 2
+NODE_DANDELION = 8
 
 #Bitfield flags
 BITFIELD_DOESACK = 1
@@ -191,7 +192,12 @@ def CreatePacket(command, payload=''):
 def assembleVersionMessage(remoteHost, remotePort, participatingStreams, server = False, nodeid = None):
     payload = ''
     payload += pack('>L', 3)  # protocol version.
-    payload += pack('>q', NODE_NETWORK|(NODE_SSL if haveSSL(server) else 0))  # bitflags of the services I offer.
+    # bitflags of the services I offer.
+    payload += pack('>q', 
+            NODE_NETWORK |
+            (NODE_SSL if haveSSL(server) else 0) |
+            (NODE_DANDELION if BMConfigParser().safeGetInt('network', 'dandelion') > 0 else 0)
+            )
     payload += pack('>q', int(time.time()))
 
     payload += pack(
@@ -203,7 +209,12 @@ def assembleVersionMessage(remoteHost, remotePort, participatingStreams, server
         payload += encodeHost(remoteHost)
         payload += pack('>H', remotePort)  # remote IPv6 and port
 
-    payload += pack('>q', NODE_NETWORK|(NODE_SSL if haveSSL(server) else 0))  # bitflags of the services I offer.
+    # bitflags of the services I offer.
+    payload += pack('>q',
+            NODE_NETWORK |
+            (NODE_SSL if haveSSL(server) else 0) |
+            (NODE_DANDELION if BMConfigParser().safeGetInt('network', 'dandelion') > 0 else 0)
+            )
     payload += '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xFF\xFF' + pack(
         '>L', 2130706433)  # = 127.0.0.1. This will be ignored by the remote host. The actual remote connected IP will be used.
     # we have a separate extPort and