337 lines
13 KiB
Python
337 lines
13 KiB
Python
from __future__ import print_function
|
|
import re, json, time
|
|
from twisted.python import log
|
|
from twisted.internet import protocol
|
|
from twisted.application import strports, service, internet
|
|
from twisted.web import server, static, resource, http
|
|
|
|
SECONDS = 1.0
|
|
MINUTE = 60*SECONDS
|
|
HOUR = 60*MINUTE
|
|
MB = 1000*1000
|
|
|
|
CHANNEL_EXPIRATION_TIME = 1*HOUR
|
|
|
|
class EventsProtocol:
|
|
def __init__(self, request):
|
|
self.request = request
|
|
|
|
def sendComment(self, comment):
|
|
# this is ignored by clients, but can keep the connection open in the
|
|
# face of firewall/NAT timeouts. It also helps unit tests, since
|
|
# apparently twisted.web.client.Agent doesn't consider the connection
|
|
# to be established until it sees the first byte of the reponse body.
|
|
self.request.write(": %s\n\n" % comment)
|
|
|
|
def sendEvent(self, data, name=None, id=None, retry=None):
|
|
if name:
|
|
self.request.write("event: %s\n" % name.encode("utf-8"))
|
|
# e.g. if name=foo, then the client web page should do:
|
|
# (new EventSource(url)).addEventListener("foo", handlerfunc)
|
|
# Note that this basically defaults to "message".
|
|
if id:
|
|
self.request.write("id: %s\n" % id.encode("utf-8"))
|
|
if retry:
|
|
self.request.write("retry: %d\n" % retry) # milliseconds
|
|
for line in data.splitlines():
|
|
self.request.write("data: %s\n" % line.encode("utf-8"))
|
|
self.request.write("\n")
|
|
|
|
def stop(self):
|
|
self.request.finish()
|
|
|
|
# note: no versions of IE (including the current IE11) support EventSource
|
|
|
|
class Channel(resource.Resource):
|
|
isLeaf = True # I handle /CHANNEL-ID/*
|
|
|
|
valid_which = ["pake", "data"]
|
|
# WHICH=(pake,data)
|
|
|
|
# these return all messages for CHANNEL-ID= and WHICH= but SIDE!=
|
|
# POST /CHANNEL-ID/SIDE/WHICH/post {message: STR} -> {messages: [STR..]}
|
|
# POST /CHANNEL-ID/SIDE/WHICH/poll -> {messages: [STR..]}
|
|
# GET /CHANNEL-ID/SIDE/WHICH/poll (eventsource) -> STR, STR, ..
|
|
#
|
|
# POST /CHANNEL-ID/SIDE/deallocate -> waiting | deleted
|
|
|
|
def __init__(self, channel_id, relay):
|
|
resource.Resource.__init__(self)
|
|
self.channel_id = channel_id
|
|
self.relay = relay
|
|
self.expire_at = time.time() + CHANNEL_EXPIRATION_TIME
|
|
self.sides = set()
|
|
self.messages = [] # (side, which, str)
|
|
self.event_channels = set() # (side, which, ep)
|
|
|
|
|
|
def render_GET(self, request):
|
|
# rest of URL is: SIDE/WHICH/(post|poll)
|
|
their_side = request.postpath[0]
|
|
their_which = request.postpath[1]
|
|
if "text/event-stream" not in (request.getHeader("accept") or ""):
|
|
request.setResponseCode(http.BAD_REQUEST, "Must use EventSource")
|
|
return "Must use EventSource (Content-Type: text/event-stream)"
|
|
request.setHeader("content-type", "text/event-stream")
|
|
ep = EventsProtocol(request)
|
|
handle = (their_side, their_which, ep)
|
|
self.event_channels.add(handle)
|
|
request.notifyFinish().addErrback(self._shutdown, handle)
|
|
for (msg_side, msg_which, msg_str) in self.messages:
|
|
self.message_added(msg_side, msg_which, msg_str, channels=[handle])
|
|
return server.NOT_DONE_YET
|
|
|
|
def _shutdown(self, _, handle):
|
|
self.event_channels.discard(handle)
|
|
|
|
|
|
def message_added(self, msg_side, msg_which, msg_str, channels=None):
|
|
if channels is None:
|
|
channels = self.event_channels
|
|
for (their_side, their_which, their_ep) in channels:
|
|
if msg_side != their_side and msg_which == their_which:
|
|
data = json.dumps({ "side": msg_side, "message": msg_str })
|
|
their_ep.sendEvent(data)
|
|
|
|
|
|
def render_POST(self, request):
|
|
# rest of URL is: SIDE/WHICH/(post|poll)
|
|
side = request.postpath[0]
|
|
self.sides.add(side)
|
|
which = request.postpath[1]
|
|
|
|
if which == "deallocate":
|
|
self.sides.remove(side)
|
|
if self.sides:
|
|
return "waiting\n"
|
|
self.relay.free_child(self.channel_id)
|
|
return "deleted\n"
|
|
|
|
if which not in self.valid_which:
|
|
request.setResponseCode(http.BAD_REQUEST)
|
|
return "bad command, want 'pake' or 'data' or 'deallocate'\n"
|
|
|
|
verb = request.postpath[2]
|
|
if verb not in ("post", "poll"):
|
|
request.setResponseCode(http.BAD_REQUEST)
|
|
return "bad verb, want 'post' or 'poll'\n"
|
|
|
|
other_messages = []
|
|
for (msg_side, msg_which, msg_str) in self.messages:
|
|
if msg_side != side and msg_which == which:
|
|
other_messages.append(msg_str)
|
|
|
|
if verb == "post":
|
|
data = json.load(request.content)
|
|
self.messages.append( (side, which, data["message"]) )
|
|
self.message_added(side, which, data["message"])
|
|
|
|
request.setHeader("content-type", "application/json; charset=utf-8")
|
|
return json.dumps({"messages": other_messages})+"\n"
|
|
|
|
class Allocated(resource.Resource):
|
|
def __init__(self, channel_id):
|
|
resource.Resource.__init__(self)
|
|
self.channel_id = channel_id
|
|
def render_POST(self, request):
|
|
request.setHeader("content-type", "application/json; charset=utf-8")
|
|
return json.dumps({"channel-id": self.channel_id})+"\n"
|
|
|
|
class ChannelList(resource.Resource):
|
|
def __init__(self, channel_ids):
|
|
resource.Resource.__init__(self)
|
|
self.channel_ids = channel_ids
|
|
def render_GET(self, request):
|
|
request.setHeader("content-type", "application/json; charset=utf-8")
|
|
return json.dumps({"channel-ids": self.channel_ids})+"\n"
|
|
|
|
class Relay(resource.Resource):
|
|
def __init__(self):
|
|
resource.Resource.__init__(self)
|
|
self.channels = {}
|
|
self.next_channel = 1
|
|
|
|
def prune_old_channels(self):
|
|
now = time.time()
|
|
for channel_id in list(self.channels):
|
|
c = self.channels[channel_id]
|
|
if c.expire_at < now:
|
|
log.msg("expiring %d" % channel_id)
|
|
self.free_child(channel_id)
|
|
|
|
def getChild(self, path, request):
|
|
if path == "allocate":
|
|
# be more clever later. Rotate through 1-99 unless they're all
|
|
# full, then rotate through 1-999, etc.
|
|
channel_id = self.next_channel
|
|
self.next_channel += 1
|
|
self.channels[channel_id] = Channel(channel_id, self)
|
|
log.msg("allocated %d, now have %d channels" %
|
|
(channel_id, len(self.channels)))
|
|
return Allocated(channel_id)
|
|
if path == "list":
|
|
channel_ids = sorted(self.channels.keys())
|
|
return ChannelList(channel_ids)
|
|
if not re.search(r'^\d+$', path):
|
|
return resource.ErrorPage(http.BAD_REQUEST,
|
|
"invalid channel id",
|
|
"invalid channel id")
|
|
channel_id = int(path)
|
|
if not channel_id in self.channels:
|
|
return resource.ErrorPage(http.NOT_FOUND,
|
|
"invalid channel id",
|
|
"invalid channel id")
|
|
return self.channels[channel_id]
|
|
|
|
def free_child(self, channel_id):
|
|
self.channels.pop(channel_id)
|
|
log.msg("freed %d, now have %d channels" %
|
|
(channel_id, len(self.channels)))
|
|
if not self.channels:
|
|
self.next_channel = 1
|
|
|
|
class TransitConnection(protocol.Protocol):
|
|
def __init__(self):
|
|
self.got_token = False
|
|
self.token_buffer = b""
|
|
self.sent_ok = False
|
|
self.buddy = None
|
|
self.total_sent = 0
|
|
|
|
def dataReceived(self, data):
|
|
if self.sent_ok:
|
|
# TODO: connect as producer/consumer
|
|
self.total_sent += len(data)
|
|
self.buddy.transport.write(data)
|
|
return
|
|
if self.got_token: # but not yet sent_ok
|
|
self.transport.write("impatient\n")
|
|
print("transit impatience failure")
|
|
return self.disconnect() # impatience yields failure
|
|
# else this should be (part of) the token
|
|
self.token_buffer += data
|
|
buf = self.token_buffer
|
|
wanted = len("please relay \n")+32*2
|
|
if len(buf) < wanted-1 and "\n" in buf:
|
|
self.transport.write("bad handshake\n")
|
|
print("transit handshake early failure")
|
|
return self.disconnect()
|
|
if len(buf) < wanted:
|
|
return
|
|
if len(buf) > wanted:
|
|
self.transport.write("impatient\n")
|
|
print("transit impatience failure")
|
|
return self.disconnect() # impatience yields failure
|
|
mo = re.search(r"^please relay (\w{64})\n", buf, re.M)
|
|
if not mo:
|
|
self.transport.write("bad handshake\n")
|
|
print("transit handshake failure")
|
|
return self.disconnect() # incorrectness yields failure
|
|
token = mo.group(1)
|
|
|
|
self.got_token = True
|
|
self.factory.connection_got_token(token, self)
|
|
|
|
def buddy_connected(self, them):
|
|
self.buddy = them
|
|
self.transport.write(b"ok\n")
|
|
self.sent_ok = True
|
|
# TODO: connect as producer/consumer
|
|
|
|
def buddy_disconnected(self):
|
|
print("buddy_disconnected %r" % self)
|
|
self.buddy = None
|
|
self.transport.loseConnection()
|
|
|
|
def connectionLost(self, reason):
|
|
print("connectionLost %r %s" % (self, reason))
|
|
if self.buddy:
|
|
self.buddy.buddy_disconnected()
|
|
self.factory.transitFinished(self, self.total_sent)
|
|
|
|
def disconnect(self):
|
|
self.transport.loseConnection()
|
|
self.factory.transitFailed(self)
|
|
|
|
class Transit(protocol.ServerFactory, service.MultiService):
|
|
# I manage pairs of simultaneous connections to a secondary TCP port,
|
|
# both forwarded to the other. Clients must begin each connection with
|
|
# "please relay TOKEN\n". I will send "ok\n" when the matching connection
|
|
# is established, or disconnect if no matching connection is made within
|
|
# MAX_WAIT_TIME seconds. I will disconnect if you send data before the
|
|
# "ok\n". All data you get after the "ok\n" will be from the other side.
|
|
# You will not receive "ok\n" until the other side has also connected and
|
|
# submitted a matching token. The token is the same for each side.
|
|
|
|
# In addition, the connections will be dropped after MAXLENGTH bytes have
|
|
# been sent by either side, or MAXTIME seconds have elapsed after the
|
|
# matching connections were established. A future API will reveal these
|
|
# limits to clients instead of causing mysterious spontaneous failures.
|
|
|
|
# These relay connections are not half-closeable (unlike full TCP
|
|
# connections, applications will not receive any data after half-closing
|
|
# their outgoing side). Applications must negotiate shutdown with their
|
|
# peer and not close the connection until all data has finished
|
|
# transferring in both directions. Applications which only need to send
|
|
# data in one direction can use close() as usual.
|
|
|
|
MAX_WAIT_TIME = 30*SECONDS
|
|
MAXLENGTH = 10*MB
|
|
MAXTIME = 60*SECONDS
|
|
protocol = TransitConnection
|
|
|
|
def __init__(self):
|
|
service.MultiService.__init__(self)
|
|
self.pending_requests = {} # token -> TransitConnection
|
|
self.active_connections = set() # TransitConnection
|
|
|
|
def connection_got_token(self, token, p):
|
|
if token in self.pending_requests:
|
|
print("transit relay 2: %r" % token)
|
|
buddy = self.pending_requests.pop(token)
|
|
self.active_connections.add(p)
|
|
self.active_connections.add(buddy)
|
|
p.buddy_connected(buddy)
|
|
buddy.buddy_connected(p)
|
|
else:
|
|
self.pending_requests[token] = p
|
|
print("transit relay 1: %r" % token)
|
|
# TODO: timer
|
|
def transitFinished(self, p, total_sent):
|
|
print("transitFinished (%dB) %r" % (total_sent, p))
|
|
for token,tc in self.pending_requests.items():
|
|
if tc is p:
|
|
del self.pending_requests[token]
|
|
break
|
|
self.active_connections.discard(p)
|
|
|
|
def transitFailed(self, p):
|
|
print("transitFailed %r" % p)
|
|
pass
|
|
|
|
|
|
class Root(resource.Resource):
|
|
# child_FOO is a nevow thing, not a twisted.web.resource thing
|
|
def __init__(self):
|
|
resource.Resource.__init__(self)
|
|
self.putChild("", static.Data("Wormhole Relay\n", "text/plain"))
|
|
|
|
class RelayServer(service.MultiService):
|
|
def __init__(self, relayport, transitport):
|
|
service.MultiService.__init__(self)
|
|
self.root = Root()
|
|
site = server.Site(self.root)
|
|
self.relayport_service = strports.service(relayport, site)
|
|
self.relayport_service.setServiceParent(self)
|
|
self.relay = Relay() # accessible from tests
|
|
self.root.putChild("relay", self.relay)
|
|
t = internet.TimerService(5*MINUTE, self.relay.prune_old_channels)
|
|
t.setServiceParent(self)
|
|
self.transit = Transit()
|
|
self.transit.setServiceParent(self) # for the timer
|
|
self.transport_service = strports.service(transitport, self.transit)
|
|
self.transport_service.setServiceParent(self)
|
|
|
|
application = service.Application("foo")
|
|
RelayServer("tcp:8009", "tcp:8010").setServiceParent(application)
|