commit 2c8951856ccabb730186064caa90aa662ba0a128 Author: Matt Traudt sirmatt@ksu.edu Date: Tue Jun 12 21:22:17 2018 -0400

Refactor in order to remove bulky function

Use the new can_exit_to member func of the Relay class in order to remove the exits_can_exit_to member func of RelayList, which I never really liked.

Relay.can_exit_to has the same DNS-based limitations as its older brother. --- sbws/lib/destination.py | 4 ++-- sbws/lib/relaylist.py | 56 +++++++------------------------------------------ 2 files changed, 9 insertions(+), 51 deletions(-)

diff --git a/sbws/lib/destination.py b/sbws/lib/destination.py index 4d0c1f3..84dc580 100644 --- a/sbws/lib/destination.py +++ b/sbws/lib/destination.py @@ -179,8 +179,8 @@ class DestinationList: session = requests_utils.make_session(cont, timeout) usable_dests = [] for dest in self._all_dests: - possible_exits = self._rl.exits_can_exit_to( - dest.hostname, dest.port) + possible_exits = [e for e in self._rl.exits + if e.can_exit_to(dest.hostname, dest.port)] # Keep the fastest 10% of exits, or 3, whichever is larger num_keep = int(max(3, len(possible_exits) * 0.1)) possible_exits = sorted( diff --git a/sbws/lib/relaylist.py b/sbws/lib/relaylist.py index 2cc5fef..f1899ca 100644 --- a/sbws/lib/relaylist.py +++ b/sbws/lib/relaylist.py @@ -2,7 +2,6 @@ from stem.descriptor.router_status_entry import RouterStatusEntryV3 from stem.descriptor.server_descriptor import ServerDescriptor import sbws.util.stem as stem_utils from stem import Flag -from stem import DescriptorUnavailable from stem.util.connection import is_valid_ipv4_address from stem.util.connection import is_valid_ipv6_address import random @@ -89,6 +88,13 @@ class Relay: return self._from_desc('ed25519_master_key').rstrip('=')

def can_exit_to(self, host, port): + ''' + Returns if this relay can MOST LIKELY exit to the given host:port. + **host** can be a hostname, but be warned that we will resolve it + locally and use the first (arbitrary/unknown order) result when + checking exit policies, which is different than what other parts of the + code may do (leaving it up to the exit to resolve the name). + ''' if not self.exit_policy: return False assert isinstance(host, str) @@ -143,54 +149,6 @@ class RelayList: def authorities(self): return self._relays_with_flag(Flag.AUTHORITY)

- def exits_can_exit_to(self, host, port): - ''' - Return exits that can MOST LIKELY exit to the given host:port. **host** - can be a hostname, but be warned that we will resolve it locally and - use the first (arbitrary/unknown order) result when checking exit - policies, which is different than what other parts of the code may do - (leaving it up to the exit to resolve the name). - - An exit can only MOST LIKELY not just because of the above DNS - disconnect, but also because fundamentally our Tor client is most - likely using microdescriptors which do not have full information about - exit policies. - ''' - c = self._controller - if not is_valid_ipv4_address(host) and not is_valid_ipv6_address(host): - # It certainly isn't perfect trying to guess if an exit can connect - # to an ipv4/6 address based on the DNS result we got locally. But - # it's the best we can do. - # - # Also, only use the first ipv4/6 we get even if there is more than - # one. - host = resolve(host)[0] - assert is_valid_ipv4_address(host) or is_valid_ipv6_address(host) - exits = [] - for exit in self.exits: - # If we have the exit policy already, easy - if exit.exit_policy: - policy = exit.exit_policy - else: - # Otherwise ask Tor for the microdescriptor and assume the exit - # won't work if the desc isn't available - try: - fp = exit.fingerprint - policy = c.get_microdescriptor(fp).exit_policy - except DescriptorUnavailable as e: - log.debug(e) - continue - # There's a weird KeyError we sometimes hit when checking - # policy.can_exit_to()... so catch that and log about it. Maybe - # someday it can be fixed? - try: - if policy is not None and policy.can_exit_to(port=port): - exits.append(exit) - except KeyError as e: - log.exception('Got that KeyError in stem again...: %s', e) - continue - return exits - def random_relay(self): relays = self.relays return self.rng.choice(relays)