tahoe-lafs/src/allmydata/util/i2p_provider.py
meejah 1b6f477549 Pull "config" handling out of Node and hide node-derivitives
This includes:

 - refactor to create_client and _Client
 - refactor to _IntroducerNode and create_introducer
2017-11-20 12:57:20 -07:00

216 lines
9.1 KiB
Python

# -*- coding: utf-8 -*-
from __future__ import absolute_import, print_function, with_statement
import os
from twisted.internet.defer import inlineCallbacks, returnValue
from twisted.internet.endpoints import clientFromString
from twisted.internet.error import ConnectionRefusedError, ConnectError
from twisted.application import service
def _import_i2p():
# this exists to be overridden by unit tests
try:
from foolscap.connections import i2p
return i2p
except ImportError: # pragma: no cover
return None
def _import_txi2p():
try:
import txi2p
return txi2p
except ImportError: # pragma: no cover
return None
def _try_to_connect(reactor, endpoint_desc, stdout, txi2p):
# yields True or None
ep = clientFromString(reactor, endpoint_desc)
d = txi2p.testAPI(reactor, 'SAM', ep)
def _failed(f):
# depending upon what's listening at that endpoint, we might get
# various errors. If this list is too short, we might expose an
# exception to the user (causing "tahoe create-node" to fail messily)
# when we're supposed to just try the next potential port instead.
# But I don't want to catch everything, because that may hide actual
# coding errors.
f.trap(ConnectionRefusedError, # nothing listening on TCP
ConnectError, # missing unix socket, or permission denied
#ValueError,
# connecting to e.g. an HTTP server causes an
# UnhandledException (around a ValueError) when the handshake
# fails to parse, but that's not something we can catch. The
# attempt hangs, so don't do that.
RuntimeError, # authentication failure
)
if stdout:
stdout.write("Unable to reach I2P SAM API at '%s': %s\n" %
(endpoint_desc, f.value))
return None
d.addErrback(_failed)
return d
@inlineCallbacks
def _connect_to_i2p(reactor, cli_config, txi2p):
# we assume i2p is already running
ports_to_try = ["tcp:127.0.0.1:7656"]
if cli_config["i2p-sam-port"]:
ports_to_try = [cli_config["i2p-sam-port"]]
for port in ports_to_try:
accessible = yield _try_to_connect(reactor, port, cli_config.stdout,
txi2p)
if accessible:
returnValue(port) ; break # helps editor
else:
raise ValueError("unable to reach any default I2P SAM port")
@inlineCallbacks
def create_config(reactor, cli_config):
txi2p = _import_txi2p()
if not txi2p:
raise ValueError("Cannot create I2P Destination without txi2p. "
"Please 'pip install tahoe-lafs[i2p]' to fix this.")
tahoe_config_i2p = {} # written into tahoe.cfg:[i2p]
private_dir = os.path.abspath(os.path.join(cli_config["basedir"], "private"))
stdout = cli_config.stdout
if cli_config["i2p-launch"]:
raise NotImplementedError("--i2p-launch is under development.")
else:
print("connecting to I2P (to allocate .i2p address)..", file=stdout)
sam_port = yield _connect_to_i2p(reactor, cli_config, txi2p)
print("I2P connection established", file=stdout)
tahoe_config_i2p["sam.port"] = sam_port
external_port = 3457 # TODO: pick this randomly? there's no contention.
privkeyfile = os.path.join(private_dir, "i2p_dest.privkey")
sam_endpoint = clientFromString(reactor, sam_port)
print("allocating .i2p address...", file=stdout)
dest = yield txi2p.generateDestination(reactor, privkeyfile, 'SAM', sam_endpoint)
print(".i2p address allocated", file=stdout)
i2p_port = "listen:i2p" # means "see [i2p]", calls Provider.get_listener()
i2p_location = "i2p:%s:%d" % (dest.host, external_port)
# in addition to the "how to launch/connect-to i2p" keys above, we also
# record information about the I2P service into tahoe.cfg.
# * "port" is the random "public Destination port" (integer), which
# (when combined with the .i2p address) should match "i2p_location"
# (which will be added to tub.location)
# * "private_key_file" points to the on-disk copy of the private key
# material (although we always write it to the same place)
tahoe_config_i2p["dest"] = "true"
tahoe_config_i2p["dest.port"] = str(external_port)
tahoe_config_i2p["dest.private_key_file"] = os.path.join("private",
"i2p_dest.privkey")
# tahoe_config_i2p: this is a dictionary of keys/values to add to the
# "[i2p]" section of tahoe.cfg, which tells the new node how to launch
# I2P in the right way.
# i2p_port: a server endpoint string, it will be added to tub.port=
# i2p_location: a foolscap connection hint, "i2p:B32_ADDR:PORT"
# We assume/require that the Node gives us the same data_directory=
# at both create-node and startup time. The data directory is not
# recorded in tahoe.cfg
returnValue((tahoe_config_i2p, i2p_port, i2p_location))
# we can always create a Provider. If foolscap.connections.i2p or txi2p
# are not installed, then get_i2p_handler() will return None. If tahoe.cfg
# wants to start an I2P Destination too, then check_dest_config() will throw
# a nice error, and startService will throw an ugly error.
class Provider(service.MultiService):
def __init__(self, basedir, config, reactor):
service.MultiService.__init__(self)
self._basedir = basedir
self._config = config
self._i2p = _import_i2p()
self._txi2p = _import_txi2p()
self._reactor = reactor
def _get_i2p_config(self, *args, **kwargs):
return self._config.get_config("i2p", *args, **kwargs)
def get_listener(self):
# this is relative to BASEDIR, and our cwd should be BASEDIR
privkeyfile = self._get_i2p_config("dest.private_key_file")
external_port = self._get_i2p_config("dest.port")
sam_port = self._get_i2p_config("sam.port")
escaped_sam_port = sam_port.replace(':', '\:')
# for now, this returns a string, which then gets passed to
# endpoints.serverFromString . But it can also return an Endpoint
# directly, which means we don't need to encode all these options
# into a string
i2p_port = "i2p:%s:%s:api=SAM:apiEndpoint=%s" % \
(privkeyfile, external_port, escaped_sam_port)
return i2p_port
def get_i2p_handler(self):
enabled = self._get_i2p_config("enabled", True, boolean=True)
if not enabled:
return None
if not self._i2p:
return None
sam_port = self._get_i2p_config("sam.port", None)
launch = self._get_i2p_config("launch", False, boolean=True)
configdir = self._get_i2p_config("i2p.configdir", None)
keyfile = self._get_i2p_config("dest.private_key_file", None)
if sam_port:
if launch:
raise ValueError("tahoe.cfg [i2p] must not set both "
"sam.port and launch")
ep = clientFromString(self._reactor, sam_port)
return self._i2p.sam_endpoint(ep, keyfile=keyfile)
if launch:
executable = self._get_i2p_config("i2p.executable", None)
return self._i2p.launch(i2p_configdir=configdir, i2p_binary=executable)
if configdir:
return self._i2p.local_i2p(configdir)
return self._i2p.default(self._reactor, keyfile=keyfile)
def check_dest_config(self):
if self._get_i2p_config("dest", False, boolean=True):
if not self._txi2p:
raise ValueError("Cannot create I2P Destination without txi2p. "
"Please 'pip install tahoe-lafs[i2p]' to fix.")
# to start an I2P server, we either need an I2P SAM port, or
# we need to launch I2P
sam_port = self._get_i2p_config("sam.port", None)
launch = self._get_i2p_config("launch", False, boolean=True)
configdir = self._get_i2p_config("i2p.configdir", None)
if not sam_port and not launch and not configdir:
raise ValueError("[i2p] dest = true, but we have neither "
"sam.port= nor launch=true nor configdir=")
if sam_port and launch:
raise ValueError("tahoe.cfg [i2p] must not set both "
"sam.port and launch")
if launch:
raise NotImplementedError("[i2p] launch is under development.")
# check that all the expected Destination-specific keys are present
def require(name):
if not self._get_i2p_config("dest.%s" % name, None):
raise ValueError("[i2p] dest = true,"
" but dest.%s= is missing" % name)
require("port")
require("private_key_file")
def startService(self):
service.MultiService.startService(self)
# if we need to start I2P, now is the time
# TODO: implement i2p launching
@inlineCallbacks
def stopService(self):
# TODO: can we also stop i2p?
yield service.MultiService.stopService(self)