Revise the generateFallbackDirLine.py script to use descriptors

      fallback directory mirror lines from relay fingerprints. No more typos!

      Add the lookupFallbackDirContact.py script for automatically looking up

      operator contact info from relay fingerprints.

      Implements ticket 24706.

      Implements ticket 24706, patch by teor and atagar.

# generateFallbackDirLine.py fingerprint ...

import sys

import urllib2

import stem.descriptor.remote as remote

import stem.descriptor.remote

import stem.util.tor_tools

if len(sys.argv) <= 1:

  print "Usage: {} fingerprint ...".format(sys.argv[0])

  sys.exit(-1)

# we need the full consensus, because it has IPv6 ORPorts

# and we want a fingerprint to router mapping in routers

#

# stem returns document_handler='DOCUMENT' as a list of consensuses

# with one entry

consensus = remote.get_consensus(document_handler='DOCUMENT').run()[0]

  print('Usage: %s fingerprint ...' % sys.argv[0])

  sys.exit(1)

for fingerprint in sys.argv[1:]:

  if fingerprint in consensus.routers:

    r = consensus.routers[fingerprint]

    # Tor clients don't use DirPorts, but old code requires one for fallbacks

    if r.dir_port is not None:

      # IPv4:DirPort orport=ORPort id=Fingerprint ipv6=[IPv6]:IPv6ORPort # nick

      ipv6_or_ap_list = [ apv for apv in r.or_addresses if apv[2] ]

      ipv6_str = ""

      if len(ipv6_or_ap_list) > 0:

        ipv6_or_ap = ipv6_or_ap_list[0]

        ipv6_str = " ipv6=[{}]:{}".format(ipv6_or_ap[0], ipv6_or_ap[1])

      print ("{}:{} orport={} id={}{} # {}"

             .format(r.address, r.dir_port, r.or_port, r.fingerprint,

                     ipv6_str, r.nickname))

  if not stem.util.tor_tools.is_valid_fingerprint(fingerprint):

    print("'%s' isn't a valid relay fingerprint" % fingerprint)

    sys.exit(1)

  try:

    desc = stem.descriptor.remote.get_server_descriptors(fingerprint).run()[0]

  except urllib2.HTTPError as exc:

    if exc.code == 404:

      print('# %s not found in recent descriptors' % fingerprint)

      continue

    else:

      print "# {} needs a DirPort".format(fingerprint)    

      raise

  if not desc.dir_port:

    print("# %s needs a DirPort" % fingerprint)

  else:

    print "# {} not found in current consensus".format(fingerprint)

    ipv6_addresses = [(address, port) for address, port, is_ipv6 in desc.or_addresses if is_ipv6]

    ipv6_field = ' ipv6=[%s]:%s' % ipv6_addresses[0] if ipv6_addresses else ''

    print('%s:%s orport=%s id=%s%s # %s' % (desc.address, desc.dir_port, desc.or_port, fingerprint, ipv6_field, desc.nickname))