# Written by Bram Cohen
# modified for multitracker operation by John Hoffman
# see LICENSE.txt for license information
from BitTornado.zurllib import urlopen
from urllib import quote
from btformats import check_peers
from BitTornado.bencode import bdecode
from threading import Thread,Lock
from cStringIO import StringIO
from traceback import print_exc
from socket import error,gethostbyname
from random import shuffle
from sha import sha
from time import time
try:
from os import getpid
except ImportError:
def getpid():
return 1
try:
True
except:
True = 1
False = 0
DEBUG = False
mapbase64 = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.-'
keys = {}
basekeydata = str(getpid()) + repr(time()) + 'tracker'
def add_key(tracker):
key = ''
for i in sha(basekeydata+tracker).digest()[-6:]:
key += mapbase64[ord(i) & 0x3F]
keys[tracker] = key
def get_key(tracker):
try:
return "&key="+keys[tracker]
except:
add_key(tracker)
return "&key="+keys[tracker]
class fakeflag:
def __init__(self, state=False):
self.state = state
def wait(self):
pass
def isSet(self):
return self.state
class Rerequester:
def __init__(self, trackerlist, interval, sched, howmany, minpeers,
connect, externalsched, amount_left, up, down,
port, ip, myid, infohash, timeout, errorfunc, excfunc,
maxpeers, doneflag, upratefunc, downratefunc,
unpauseflag = fakeflag(True)):
self.excfunc = excfunc
newtrackerlist = []
for tier in trackerlist:
if len(tier) > 1:
shuffle(tier)
newtrackerlist += [tier]
self.trackerlist = newtrackerlist
self.lastsuccessful = ''
self.rejectedmessage = 'rejected by tracker - '
self.url = ('?info_hash=%s&peer_id=%s&port=%s' %
(quote(infohash), quote(myid), str(port)))
self.ip = ip
self.interval = interval
self.last = None
self.trackerid = None
self.announce_interval = 30 * 60
self.sched = sched
self.howmany = howmany
self.minpeers = minpeers
self.connect = connect
self.externalsched = externalsched
self.amount_left = amount_left
self.up = up
self.down = down
self.timeout = timeout
self.errorfunc = errorfunc
self.maxpeers = maxpeers
self.doneflag = doneflag
self.upratefunc = upratefunc
self.downratefunc = downratefunc
self.unpauseflag = unpauseflag
self.last_failed = True
self.never_succeeded = True
self.errorcodes = {}
self.lock = SuccessLock()
self.special = None
self.stopped = False
def start(self):
self.sched(self.c, self.interval/2)
self.d(0)
def c(self):
if self.stopped:
return
if not self.unpauseflag.isSet() and self.howmany() < self.minpeers:
self.announce(3, self._c)
else:
self._c()
def _c(self):
self.sched(self.c, self.interval)
def d(self, event = 3):
if self.stopped:
return
if not self.unpauseflag.isSet():
self._d()
return
self.announce(event, self._d)
def _d(self):
if self.never_succeeded:
self.sched(self.d, 60) # retry in 60 seconds
else:
self.sched(self.d, self.announce_interval)
def announce(self, event = 3, callback = lambda: None, specialurl = None):
if specialurl is not None:
s = self.url+'&uploaded=0&downloaded=0&left=1' # don't add to statistics
if self.howmany() >= self.maxpeers:
s += '&numwant=0'
else:
s += '&no_peer_id=1&compact=1'
self.last_failed = True # force true, so will display an error
self.special = specialurl
self.rerequest(s, callback)
return
else:
s = ('%s&uploaded=%s&downloaded=%s&left=%s' %
(self.url, str(self.up()), str(self.down()),
str(self.amount_left())))
if self.last is not None:
s += '&last=' + quote(str(self.last))
if self.trackerid is not None:
s += '&trackerid=' + quote(str(self.trackerid))
if self.howmany() >= self.maxpeers:
s += '&numwant=0'
else:
s += '&no_peer_id=1&compact=1'
if event != 3:
s += '&event=' + ['started', 'completed', 'stopped'][event]
if event == 2:
self.stopped = True
self.rerequest(s, callback)
def snoop(self, peers, callback = lambda: None): # tracker call support
self.rerequest(self.url
+'&event=stopped&port=0&uploaded=0&downloaded=0&left=1&tracker=1&numwant='
+str(peers), callback)
def rerequest(self, s, callback):
if not self.lock.isfinished(): # still waiting for prior cycle to complete??
def retry(self = self, s = s, callback = callback):
self.rerequest(s, callback)
self.sched(retry, 5) # retry in 5 seconds
return
self.lock.reset()
rq = Thread(target = self._rerequest, args = [s, callback])
# Arno: make this a daemon thread so the client closes sooner.
rq.setDaemon(True)
rq.start()
def _rerequest(self, s, callback):
try:
def fail(self = self, callback = callback):
self._fail(callback)
if self.ip:
try:
s += '&ip=' + gethostbyname(self.ip)
except:
self.errorcodes['troublecode'] = 'unable to resolve: '+self.ip
self.externalsched(fail)
self.errorcodes = {}
if self.special is None:
for t in range(len(self.trackerlist)):
for tr in range(len(self.trackerlist[t])):
tracker = self.trackerlist[t][tr]
# Arno: no udp support yet
if tracker.startswith( 'udp:' ):
if DEBUG:
print "Rerequest tracker: ignoring",tracker
continue
if self.rerequest_single(tracker, s, callback):
if not self.last_failed and tr != 0:
del self.trackerlist[t][tr]
self.trackerlist[t] = [tracker] + self.trackerlist[t]
return
else:
tracker = self.special
self.special = None
if self.rerequest_single(tracker, s, callback):
return
# no success from any tracker
self.externalsched(fail)
except:
self.exception(callback)
def _fail(self, callback):
if ( (self.upratefunc() < 100 and self.downratefunc() < 100)
or not self.amount_left() ):
for f in ['rejected', 'bad_data', 'troublecode']:
if self.errorcodes.has_key(f):
r = self.errorcodes[f]
break
else:
r = 'Problem connecting to tracker - unspecified error'
self.errorfunc(r)
self.last_failed = True
self.lock.give_up()
self.externalsched(callback)
def rerequest_single(self, t, s, callback):
l = self.lock.set()
rq = Thread(target = self._rerequest_single, args = [t, s+get_key(t), l, callback])
# Arno: make this a daemon thread so the client closes sooner.
rq.setDaemon(True)
rq.start()
self.lock.wait()
if self.lock.success:
self.lastsuccessful = t
self.last_failed = False
self.never_succeeded = False
return True
if not self.last_failed and self.lastsuccessful == t:
# if the last tracker hit was successful, and you've just tried the tracker
# you'd contacted before, don't go any further, just fail silently.
self.last_failed = True
self.externalsched(callback)
self.lock.give_up()
return True
return False # returns true if it wants rerequest() to exit
def _rerequest_single(self, t, s, l, callback):
try:
closer = [None]
def timedout(self = self, l = l, closer = closer):
if self.lock.trip(l):
self.errorcodes['troublecode'] = 'Problem connecting to tracker - timeout exceeded'
self.lock.unwait(l)
try:
closer[0]()
except:
pass
self.externalsched(timedout, self.timeout)
err = None
try:
if DEBUG:
print "Rerequest tracker:"
print t+s
h = urlopen(t+s)
closer[0] = h.close
data = h.read()
except (IOError, error), e:
err = 'Problem connecting to tracker - ' + str(e)
except:
err = 'Problem connecting to tracker'
try:
h.close()
except:
pass
if err:
if self.lock.trip(l):
self.errorcodes['troublecode'] = err
self.lock.unwait(l)
return
if not data:
if self.lock.trip(l):
self.errorcodes['troublecode'] = 'no data from tracker'
self.lock.unwait(l)
return
try:
r = bdecode(data, sloppy=1)
check_peers(r)
if DEBUG:
print "Tracker returns:", r
except ValueError, e:
if self.lock.trip(l):
self.errorcodes['bad_data'] = 'bad data from tracker - ' + str(e)
self.lock.unwait(l)
return
if r.has_key('failure reason'):
if self.lock.trip(l):
self.errorcodes['rejected'] = self.rejectedmessage + r['failure reason']
self.lock.unwait(l)
return
if self.lock.trip(l, True): # success!
self.lock.unwait(l)
else:
callback = lambda: None # attempt timed out, don't do a callback
# even if the attempt timed out, go ahead and process data
def add(self = self, r = r, callback = callback):
self.postrequest(r, callback)
self.externalsched(add)
except:
self.exception(callback)
def postrequest(self, r, callback):
if r.has_key('warning message'):
self.errorfunc('warning from tracker - ' + r['warning message'])
self.announce_interval = r.get('interval', self.announce_interval)
self.interval = r.get('min interval', self.interval)
self.trackerid = r.get('tracker id', self.trackerid)
self.last = r.get('last')
# ps = len(r['peers']) + self.howmany()
p = r['peers']
peers = []
if type(p) == type(''):
for x in xrange(0, len(p), 6):
ip = '.'.join([str(ord(i)) for i in p[x:x+4]])
port = (ord(p[x+4]) << 8) | ord(p[x+5])
peers.append(((ip, port), 0))
else:
for x in p:
peers.append(((x['ip'].strip(), x['port']), x.get('peer id', 0)))
ps = len(peers) + self.howmany()
if ps < self.maxpeers:
if self.doneflag.isSet():
if r.get('num peers', 1000) - r.get('done peers', 0) > ps * 1.2:
self.last = None
else:
if r.get('num peers', 1000) > ps * 1.2:
self.last = None
if peers:
shuffle(peers)
self.connect(peers) # Encoder.start_connections(peers)
callback()
def exception(self, callback):
data = StringIO()
print_exc(file = data)
def r(s = data.getvalue(), callback = callback):
if self.excfunc:
self.excfunc(s)
else:
print s
callback()
self.externalsched(r)
class SuccessLock:
def __init__(self):
self.lock = Lock()
self.pause = Lock()
self.code = 0L
self.success = False
self.finished = True
def reset(self):
self.success = False
self.finished = False
def set(self):
self.lock.acquire()
if not self.pause.locked():
self.pause.acquire()
self.first = True
self.code += 1L
self.lock.release()
return self.code
def trip(self, code, s = False):
self.lock.acquire()
try:
if code == self.code and not self.finished:
r = self.first
self.first = False
if s:
self.finished = True
self.success = True
return r
finally:
self.lock.release()
def give_up(self):
self.lock.acquire()
self.success = False
self.finished = True
self.lock.release()
def wait(self):
self.pause.acquire()
def unwait(self, code):
if code == self.code and self.pause.locked():
self.pause.release()
def isfinished(self):
self.lock.acquire()
x = self.finished
self.lock.release()
return x
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