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- #!/usr/bin/env python3
- import random # For simulation, not cryptography!
- import math
- import network
- import dirauth
- import relay
- class CellClient(relay.CellHandler):
- """The subclass of CellHandler for clients."""
- def __init__(self, myaddr, dirauthaddrs, perfstats):
- super().__init__(myaddr, dirauthaddrs, perfstats)
- self.guardaddr = None
- if network.thenetwork.womode == network.WOMode.VANILLA:
- self.consensus_cdf = []
- def get_consensus_from_fallbackrelay(self):
- """Download a fresh consensus from a random fallbackrelay."""
- fb = random.choice(network.thenetwork.getfallbackrelays())
- self.send_msg(relay.RelayGetConsensusMsg(), fb.netaddr)
- def ensure_guard_vanilla(self):
- """Ensure that we have a channel to a guard (Vanilla Onion
- Routing version)."""
- while True:
- if self.guardaddr is None:
- # Pick a guard from the consensus
- guard = self.consensus.select_weighted_relay(self.consensus_cdf)
- self.guardaddr = guard.descdict['addr']
- # Connect to the guard
- try:
- self.get_channel_to(self.guardaddr)
- except network.NetNoServer:
- # Our guard is gone
- self.guardaddr = None
- if self.guardaddr is not None:
- break
- print('chose guard=', self.guardaddr)
- def ensure_guard(self):
- """Ensure that we have a channel to a guard."""
- if network.thenetwork.womode == network.WOMode.VANILLA:
- self.ensure_guard_vanilla()
- def new_circuit_vanilla(self):
- """Create a new circuit from this client. (Vanilla Onion Routing
- version)"""
- def new_circuit(self):
- """Create a new circuit from this client."""
- if network.thenetwork.womode == network.WOMode.VANILLA:
- self.new_circuit_vanilla()
- def received_msg(self, msg, peeraddr, peer):
- """Callback when a NetMsg not specific to a circuit is
- received."""
- print("Client %s received msg %s from %s" % (self.myaddr, msg, peeraddr))
- if isinstance(msg, relay.RelayConsensusMsg):
- self.consensus = msg.consensus
- dirauth.Consensus.verify(self.consensus, \
- network.thenetwork.dirauthkeys(), self.perfstats)
- if network.thenetwork.womode == network.WOMode.VANILLA:
- self.consensus_cdf = self.consensus.bw_cdf()
- else:
- return super().received_msg(msg, peeraddr, peer)
- def received_cell(self, circid, cell, peeraddr, peer):
- """Callback with a circuit-specific cell is received."""
- print("Client %s received cell on circ %d: %s from %s" % (self.myaddr, circid, cell, peeraddr))
- return super().received_cell(circid, cell, peeraddr, peer)
- class Client:
- """A class representing a Tor client."""
- def __init__(self, dirauthaddrs):
- # Get a network address for client-side use only (do not bind it
- # to the network)
- self.netaddr = network.NetAddr()
- self.perfstats = network.PerfStats(network.EntType.CLIENT)
- self.perfstats.name = "Client at %s" % self.netaddr
- self.perfstats.is_bootstrapping = True
- self.cellhandler = CellClient(self.netaddr, dirauthaddrs, self.perfstats)
- # Register for epoch tick notifications
- network.thenetwork.wantepochticks(self, True)
- def terminate(self):
- """Quit this client."""
- # Stop listening for epoch ticks
- network.thenetwork.wantepochticks(self, False)
- # Close relay connections
- self.cellhandler.terminate()
- def get_consensus(self):
- """Fetch a new consensus."""
- # We're going to want a new consensus from our guard. In order
- # to get that, we'll need a channel to our guard. In order to
- # get that, we'll need a guard address. In order to get that,
- # we'll need a consensus (uh, oh; in that case, fetch the
- # consensus from a fallback relay).
- self.cellhandler.get_consensus_from_fallbackrelay()
- print('client consensus=', self.cellhandler.consensus)
- def newepoch(self, epoch):
- """Callback that fires at the start of each epoch"""
- # We'll need a new consensus
- self.get_consensus()
- # If we don't have a guard, pick one and make a channel to it
- self.cellhandler.ensure_guard()
- if __name__ == '__main__':
- perfstats = network.PerfStats(network.EntType.NONE)
- totsent = 0
- totrecv = 0
- dirasent = 0
- dirarecv = 0
- relaysent = 0
- relayrecv = 0
- clisent = 0
- clirecv = 0
- # Start some dirauths
- numdirauths = 9
- dirauthaddrs = []
- dirauths = []
- for i in range(numdirauths):
- dira = dirauth.DirAuth(i, numdirauths)
- dirauths.append(dira)
- dirauthaddrs.append(dira.netaddr)
- # Start some relays
- numrelays = 10
- relays = []
- for i in range(numrelays):
- # Relay bandwidths (at least the ones fast enough to get used)
- # in the live Tor network (as of Dec 2019) are well approximated
- # by (200000-(200000-25000)/3*log10(x)) where x is a
- # uniform integer in [1,2500]
- x = random.randint(1,2500)
- bw = int(200000-(200000-25000)/3*math.log10(x))
- relays.append(relay.Relay(dirauthaddrs, bw, 0))
- # The fallback relays are a hardcoded list of about 5% of the
- # relays, used by clients for bootstrapping
- numfallbackrelays = int(numrelays * 0.05) + 1
- fallbackrelays = random.sample(relays, numfallbackrelays)
- for r in fallbackrelays:
- r.set_is_fallbackrelay()
- network.thenetwork.setfallbackrelays(fallbackrelays)
- # Tick the epoch
- network.thenetwork.nextepoch()
- dirauth.Consensus.verify(dirauth.DirAuth.consensus, network.thenetwork.dirauthkeys(), perfstats)
- print('ticked; epoch=', network.thenetwork.getepoch())
- relays[3].cellhandler.send_msg(relay.RelayRandomHopMsg(30), relays[5].netaddr)
- # See what channels exist and do a consistency check
- for r in relays:
- print("%s: %s" % (r.netaddr, [ str(k) for k in r.cellhandler.channels.keys()]))
- raddr = r.netaddr
- for ad, ch in r.cellhandler.channels.items():
- if ch.peer.cellhandler.myaddr != ad:
- print('address mismatch:', raddr, ad, ch.peer.cellhandler.myaddr)
- if ch.peer.cellhandler.channels[raddr].peer is not ch:
- print('asymmetry:', raddr, ad, ch, ch.peer.cellhandler.channels[raddr].peer)
- # Start some clients
- numclients = 1
- clients = []
- for i in range(numclients):
- clients.append(Client(dirauthaddrs))
- # Tick the epoch
- network.thenetwork.nextepoch()
- # See what channels exist and do a consistency check
- for c in clients:
- print("%s: %s" % (c.netaddr, [ str(k) for k in c.cellhandler.channels.keys()]))
- caddr = c.netaddr
- for ad, ch in c.cellhandler.channels.items():
- if ch.peer.cellhandler.myaddr != ad:
- print('address mismatch:', caddr, ad, ch.peer.cellhandler.myaddr)
- if ch.peer.cellhandler.channels[caddr].peer is not ch:
- print('asymmetry:', caddr, ad, ch, ch.peer.cellhandler.channels[caddr].peer)
- # Pick a bunch of bw-weighted random relays and look at the
- # distribution
- for i in range(100):
- r = clients[0].cellhandler.consensus.select_weighted_relay(clients[0].cellhandler.consensus_cdf)
- print("relay",r.descdict["addr"])
- relays[3].terminate()
- relaysent += relays[3].perfstats.bytes_sent
- relayrecv += relays[3].perfstats.bytes_received
- del relays[3]
- # Tick the epoch
- network.thenetwork.nextepoch()
- # See what channels exist and do a consistency check
- for c in clients:
- print("%s: %s" % (c.netaddr, [ str(k) for k in c.cellhandler.channels.keys()]))
- caddr = c.netaddr
- for ad, ch in c.cellhandler.channels.items():
- if ch.peer.cellhandler.myaddr != ad:
- print('address mismatch:', caddr, ad, ch.peer.cellhandler.myaddr)
- if ch.peer.cellhandler.channels[caddr].peer is not ch:
- print('asymmetry:', caddr, ad, ch, ch.peer.cellhandler.channels[caddr].peer)
- clients[0].cellhandler.new_circuit()
- for d in dirauths:
- print(d.perfstats)
- dirasent += d.perfstats.bytes_sent
- dirarecv += d.perfstats.bytes_received
- print("DirAuths sent=%d recv=%d" % (dirasent, dirarecv))
- totsent += dirasent
- totrecv += dirarecv
- for r in relays:
- print(r.perfstats)
- relaysent += r.perfstats.bytes_sent
- relayrecv += r.perfstats.bytes_received
- print("Relays sent=%d recv=%d" % (relaysent, relayrecv))
- totsent += relaysent
- totrecv += relayrecv
- for c in clients:
- print(c.perfstats)
- clisent += c.perfstats.bytes_sent
- clirecv += c.perfstats.bytes_received
- print("Client sent=%d recv=%d" % (clisent, clirecv))
- totsent += clisent
- totrecv += clirecv
- print("Total sent=%d recv=%d" % (totsent, totrecv))
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