tahoe-lafs/src/allmydata/introducer/server.py
Brian Warner 3e26c78ee3 introducer.client: use integer seqnums, not time-based. Closes #1767.
This stores the sequence number in BASEDIR/announcement-seqnum, and
increments it each time any service is published (every service
announcement is regenerated with the new sequence number). As everyone
knows, time is an illusion, and occasionally goes backwards, so a
counter is generally safer (and reveals less information about the
node).

Later, we'll improve the introducer client to tolerate rollbacks (where,
perhaps due to a VM being restarted from an earlier checkpoint, the
stored sequence number reverts to an earlier version).
2013-03-18 17:40:56 -07:00

356 lines
16 KiB
Python

import time, os.path
from zope.interface import implements
from twisted.application import service
from foolscap.api import Referenceable
import allmydata
from allmydata import node
from allmydata.util import log, rrefutil
from allmydata.introducer.interfaces import \
RIIntroducerPublisherAndSubscriberService_v2
from allmydata.introducer.common import convert_announcement_v1_to_v2, \
convert_announcement_v2_to_v1, unsign_from_foolscap, make_index, \
get_tubid_string_from_ann, SubscriberDescriptor, AnnouncementDescriptor
class IntroducerNode(node.Node):
PORTNUMFILE = "introducer.port"
NODETYPE = "introducer"
GENERATED_FILES = ['introducer.furl']
def __init__(self, basedir="."):
node.Node.__init__(self, basedir)
self.read_config()
self.init_introducer()
webport = self.get_config("node", "web.port", None)
if webport:
self.init_web(webport) # strports string
def init_introducer(self):
introducerservice = IntroducerService(self.basedir)
self.add_service(introducerservice)
d = self.when_tub_ready()
def _publish(res):
self.introducer_url = self.tub.registerReference(introducerservice,
"introducer")
self.log(" introducer is at %s" % self.introducer_url,
umid="qF2L9A")
self.write_config("introducer.furl", self.introducer_url + "\n")
d.addCallback(_publish)
d.addErrback(log.err, facility="tahoe.init",
level=log.BAD, umid="UaNs9A")
def init_web(self, webport):
self.log("init_web(webport=%s)", args=(webport,), umid="2bUygA")
from allmydata.webish import IntroducerWebishServer
nodeurl_path = os.path.join(self.basedir, "node.url")
staticdir = self.get_config("node", "web.static", "public_html")
staticdir = os.path.expanduser(staticdir)
ws = IntroducerWebishServer(self, webport, nodeurl_path, staticdir)
self.add_service(ws)
class WrapV1SubscriberInV2Interface: # for_v1
"""I wrap a RemoteReference that points at an old v1 subscriber, enabling
it to be treated like a v2 subscriber.
"""
def __init__(self, original):
self.original = original # also used for tests
def __eq__(self, them):
return self.original == them
def __ne__(self, them):
return self.original != them
def __hash__(self):
return hash(self.original)
def getRemoteTubID(self):
return self.original.getRemoteTubID()
def getSturdyRef(self):
return self.original.getSturdyRef()
def getPeer(self):
return self.original.getPeer()
def getLocationHints(self):
return self.original.getLocationHints()
def callRemote(self, methname, *args, **kwargs):
m = getattr(self, "wrap_" + methname)
return m(*args, **kwargs)
def wrap_announce_v2(self, announcements):
anns_v1 = [convert_announcement_v2_to_v1(ann) for ann in announcements]
return self.original.callRemote("announce", set(anns_v1))
def wrap_set_encoding_parameters(self, parameters):
# note: unused
return self.original.callRemote("set_encoding_parameters", parameters)
def notifyOnDisconnect(self, *args, **kwargs):
return self.original.notifyOnDisconnect(*args, **kwargs)
class IntroducerService(service.MultiService, Referenceable):
implements(RIIntroducerPublisherAndSubscriberService_v2)
name = "introducer"
# v1 is the original protocol, supported since 1.0 (but only advertised
# starting in 1.3). v2 is the new signed protocol, supported after 1.9
VERSION = { "http://allmydata.org/tahoe/protocols/introducer/v1": { },
"http://allmydata.org/tahoe/protocols/introducer/v2": { },
"application-version": str(allmydata.__full_version__),
}
def __init__(self, basedir="."):
service.MultiService.__init__(self)
self.introducer_url = None
# 'index' is (service_name, key_s, tubid), where key_s or tubid is
# None
self._announcements = {} # dict of index ->
# (ann_t, canary, ann, timestamp)
# ann (the announcement dictionary) is cleaned up: nickname is always
# unicode, servicename is always ascii, etc, even though
# simplejson.loads sometimes returns either
# self._subscribers is a dict mapping servicename to subscriptions
# 'subscriptions' is a dict mapping rref to a subscription
# 'subscription' is a tuple of (subscriber_info, timestamp)
# 'subscriber_info' is a dict, provided directly for v2 clients, or
# synthesized for v1 clients. The expected keys are:
# version, nickname, app-versions, my-version, oldest-supported
self._subscribers = {}
# self._stub_client_announcements contains the information provided
# by v1 clients. We stash this so we can match it up with their
# subscriptions.
self._stub_client_announcements = {} # maps tubid to sinfo # for_v1
self._debug_counts = {"inbound_message": 0,
"inbound_duplicate": 0,
"inbound_no_seqnum": 0,
"inbound_old_replay": 0,
"inbound_update": 0,
"outbound_message": 0,
"outbound_announcements": 0,
"inbound_subscribe": 0}
self._debug_outstanding = 0 # also covers WrapV1SubscriberInV2Interface
def _debug_retired(self, res):
self._debug_outstanding -= 1
return res
def log(self, *args, **kwargs):
if "facility" not in kwargs:
kwargs["facility"] = "tahoe.introducer.server"
return log.msg(*args, **kwargs)
def get_announcements(self, include_stub_clients=True):
"""Return a list of AnnouncementDescriptor for all announcements"""
announcements = []
for (index, (_, canary, ann, when)) in self._announcements.items():
if ann["service-name"] == "stub_client":
if not include_stub_clients:
continue
ad = AnnouncementDescriptor(when, index, canary, ann)
announcements.append(ad)
return announcements
def get_subscribers(self):
"""Return a list of SubscriberDescriptor objects for all subscribers"""
s = []
for service_name, subscriptions in self._subscribers.items():
for rref,(subscriber_info,when) in subscriptions.items():
# note that if the subscriber didn't do Tub.setLocation,
# tubid will be None. Also, subscribers do not tell us which
# pubkey they use; only publishers do that.
tubid = rref.getRemoteTubID() or "?"
advertised_addresses = rrefutil.hosts_for_rref(rref)
remote_address = rrefutil.stringify_remote_address(rref)
# these three assume subscriber_info["version"]==0, but
# should tolerate other versions
if not subscriber_info:
# V1 clients that haven't yet sent their stub_info data
subscriber_info = {}
nickname = subscriber_info.get("nickname", u"?")
version = subscriber_info.get("my-version", u"?")
app_versions = subscriber_info.get("app-versions", {})
# 'when' is the time they subscribed
sd = SubscriberDescriptor(service_name, when,
nickname, version, app_versions,
advertised_addresses, remote_address,
tubid)
s.append(sd)
return s
def remote_get_version(self):
return self.VERSION
def remote_publish(self, ann_t): # for_v1
lp = self.log("introducer: old (v1) announcement published: %s"
% (ann_t,), umid="6zGOIw")
ann_v2 = convert_announcement_v1_to_v2(ann_t)
return self.publish(ann_v2, None, lp)
def remote_publish_v2(self, ann_t, canary):
lp = self.log("introducer: announcement (v2) published", umid="L2QXkQ")
return self.publish(ann_t, canary, lp)
def publish(self, ann_t, canary, lp):
try:
self._publish(ann_t, canary, lp)
except:
log.err(format="Introducer.remote_publish failed on %(ann)s",
ann=ann_t,
level=log.UNUSUAL, parent=lp, umid="620rWA")
raise
def _publish(self, ann_t, canary, lp):
self._debug_counts["inbound_message"] += 1
self.log("introducer: announcement published: %s" % (ann_t,),
umid="wKHgCw")
ann, key = unsign_from_foolscap(ann_t) # might raise BadSignatureError
index = make_index(ann, key)
service_name = str(ann["service-name"])
if service_name == "stub_client": # for_v1
self._attach_stub_client(ann, lp)
return
old = self._announcements.get(index)
if old:
(old_ann_t, canary, old_ann, timestamp) = old
if old_ann == ann:
self.log("but we already knew it, ignoring", level=log.NOISY,
umid="myxzLw")
self._debug_counts["inbound_duplicate"] += 1
return
else:
if "seqnum" in old_ann:
# must beat previous sequence number to replace
if ("seqnum" not in ann
or not isinstance(ann["seqnum"], (int,long))):
self.log("not replacing old ann, no valid seqnum",
level=log.NOISY, umid="ySbaVw")
self._debug_counts["inbound_no_seqnum"] += 1
return
if ann["seqnum"] <= old_ann["seqnum"]:
self.log("not replacing old ann, new seqnum is too old"
" (%s <= %s) (replay attack?)"
% (ann["seqnum"], old_ann["seqnum"]),
level=log.UNUSUAL, umid="sX7yqQ")
self._debug_counts["inbound_old_replay"] += 1
return
# ok, seqnum is newer, allow replacement
self.log("old announcement being updated", level=log.NOISY,
umid="304r9g")
self._debug_counts["inbound_update"] += 1
self._announcements[index] = (ann_t, canary, ann, time.time())
#if canary:
# canary.notifyOnDisconnect ...
# use a CanaryWatcher? with cw.is_connected()?
# actually we just want foolscap to give rref.is_connected(), since
# this is only for the status display
for s in self._subscribers.get(service_name, []):
self._debug_counts["outbound_message"] += 1
self._debug_counts["outbound_announcements"] += 1
self._debug_outstanding += 1
d = s.callRemote("announce_v2", set([ann_t]))
d.addBoth(self._debug_retired)
d.addErrback(log.err,
format="subscriber errored on announcement %(ann)s",
ann=ann_t, facility="tahoe.introducer",
level=log.UNUSUAL, umid="jfGMXQ")
def _attach_stub_client(self, ann, lp):
# There might be a v1 subscriber for whom this is a stub_client.
# We might have received the subscription before the stub_client
# announcement, in which case we now need to fix up the record in
# self._subscriptions .
# record it for later, in case the stub_client arrived before the
# subscription
subscriber_info = self._get_subscriber_info_from_ann(ann)
ann_tubid = get_tubid_string_from_ann(ann)
self._stub_client_announcements[ann_tubid] = subscriber_info
lp2 = self.log("stub_client announcement, "
"looking for matching subscriber",
parent=lp, level=log.NOISY, umid="BTywDg")
for sn in self._subscribers:
s = self._subscribers[sn]
for (subscriber, info) in s.items():
# we correlate these by looking for a subscriber whose tubid
# matches this announcement
sub_tubid = subscriber.getRemoteTubID()
if sub_tubid == ann_tubid:
self.log(format="found a match, nodeid=%(nodeid)s",
nodeid=sub_tubid,
level=log.NOISY, parent=lp2, umid="xsWs1A")
# found a match. Does it need info?
if not info[0]:
self.log(format="replacing info",
level=log.NOISY, parent=lp2, umid="m5kxwA")
# yup
s[subscriber] = (subscriber_info, info[1])
# and we don't remember or announce stub_clients beyond what we
# need to get the subscriber_info set up
def _get_subscriber_info_from_ann(self, ann): # for_v1
sinfo = { "version": ann["version"],
"nickname": ann["nickname"],
"app-versions": ann["app-versions"],
"my-version": ann["my-version"],
"oldest-supported": ann["oldest-supported"],
}
return sinfo
def remote_subscribe(self, subscriber, service_name): # for_v1
self.log("introducer: old (v1) subscription[%s] request at %s"
% (service_name, subscriber), umid="hJlGUg")
return self.add_subscriber(WrapV1SubscriberInV2Interface(subscriber),
service_name, None)
def remote_subscribe_v2(self, subscriber, service_name, subscriber_info):
self.log("introducer: subscription[%s] request at %s"
% (service_name, subscriber), umid="U3uzLg")
return self.add_subscriber(subscriber, service_name, subscriber_info)
def add_subscriber(self, subscriber, service_name, subscriber_info):
self._debug_counts["inbound_subscribe"] += 1
if service_name not in self._subscribers:
self._subscribers[service_name] = {}
subscribers = self._subscribers[service_name]
if subscriber in subscribers:
self.log("but they're already subscribed, ignoring",
level=log.UNUSUAL, umid="Sy9EfA")
return
if not subscriber_info: # for_v1
# v1 clients don't provide subscriber_info, but they should
# publish a 'stub client' record which contains the same
# information. If we've already received this, it will be in
# self._stub_client_announcements
tubid = subscriber.getRemoteTubID()
if tubid in self._stub_client_announcements:
subscriber_info = self._stub_client_announcements[tubid]
subscribers[subscriber] = (subscriber_info, time.time())
def _remove():
self.log("introducer: unsubscribing[%s] %s" % (service_name,
subscriber),
umid="vYGcJg")
subscribers.pop(subscriber, None)
subscriber.notifyOnDisconnect(_remove)
# now tell them about any announcements they're interested in
announcements = set( [ ann_t
for idx,(ann_t,canary,ann,when)
in self._announcements.items()
if idx[0] == service_name] )
if announcements:
self._debug_counts["outbound_message"] += 1
self._debug_counts["outbound_announcements"] += len(announcements)
self._debug_outstanding += 1
d = subscriber.callRemote("announce_v2", announcements)
d.addBoth(self._debug_retired)
d.addErrback(log.err,
format="subscriber errored during subscribe %(anns)s",
anns=announcements, facility="tahoe.introducer",
level=log.UNUSUAL, umid="mtZepQ")
return d