nova/nova/console/websocketproxy.py

342 lines
14 KiB
Python

# Copyright (c) 2012 OpenStack Foundation
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
'''
Websocket proxy that is compatible with OpenStack Nova.
Leverages websockify.py by Joel Martin
'''
import copy
import socket
import sys
from oslo_log import log as logging
from oslo_utils import encodeutils
import six
from six.moves import http_cookies as Cookie
import six.moves.urllib.parse as urlparse
import websockify
from nova.compute import rpcapi as compute_rpcapi
import nova.conf
from nova.consoleauth import rpcapi as consoleauth_rpcapi
from nova import context
from nova import exception
from nova.i18n import _
from nova import objects
LOG = logging.getLogger(__name__)
CONF = nova.conf.CONF
class TenantSock(object):
"""A socket wrapper for communicating with the tenant.
This class provides a socket-like interface to the internal
websockify send/receive queue for the client connection to
the tenant user. It is used with the security proxy classes.
"""
def __init__(self, reqhandler):
self.reqhandler = reqhandler
self.queue = []
def recv(self, cnt):
# NB(sross): it's ok to block here because we know
# exactly the sequence of data arriving
while len(self.queue) < cnt:
# new_frames looks like ['abc', 'def']
new_frames, closed = self.reqhandler.recv_frames()
# flatten frames onto queue
for frame in new_frames:
# The socket returns (byte) strings in Python 2...
if six.PY2:
self.queue.extend(frame)
# ...and integers in Python 3. For the Python 3 case, we need
# to convert these to characters using 'chr' and then, as this
# returns unicode, convert the result to byte strings.
else:
self.queue.extend(
[six.binary_type(chr(c), 'ascii') for c in frame])
if closed:
break
popped = self.queue[0:cnt]
del self.queue[0:cnt]
return b''.join(popped)
def sendall(self, data):
self.reqhandler.send_frames([encodeutils.safe_encode(data)])
def finish_up(self):
self.reqhandler.send_frames([b''.join(self.queue)])
def close(self):
self.finish_up()
self.reqhandler.send_close()
class NovaProxyRequestHandlerBase(object):
def address_string(self):
# NOTE(rpodolyaka): override the superclass implementation here and
# explicitly disable the reverse DNS lookup, which might fail on some
# deployments due to DNS configuration and break VNC access completely
return str(self.client_address[0])
def verify_origin_proto(self, connection_info, origin_proto):
access_url = connection_info.get('access_url')
if not access_url:
detail = _("No access_url in connection_info. "
"Cannot validate protocol")
raise exception.ValidationError(detail=detail)
expected_protos = [urlparse.urlparse(access_url).scheme]
# NOTE: For serial consoles the expected protocol could be ws or
# wss which correspond to http and https respectively in terms of
# security.
if 'ws' in expected_protos:
expected_protos.append('http')
if 'wss' in expected_protos:
expected_protos.append('https')
return origin_proto in expected_protos
def _check_console_port(self, ctxt, instance_uuid, port, console_type):
try:
instance = objects.Instance.get_by_uuid(ctxt, instance_uuid)
except exception.InstanceNotFound:
return
# NOTE(melwitt): The port is expected to be a str for validation.
return self.compute_rpcapi.validate_console_port(ctxt, instance,
str(port),
console_type)
def _get_connect_info_consoleauth(self, ctxt, token):
# NOTE(PaulMurray) consoleauth check_token() validates the token
# and does an rpc to compute manager to check the console port
# is correct.
rpcapi = consoleauth_rpcapi.ConsoleAuthAPI()
return rpcapi.check_token(ctxt, token=token)
def _get_connect_info_database(self, ctxt, token):
# NOTE(PaulMurray) ConsoleAuthToken.validate validates the token.
# We call the compute manager directly to check the console port
# is correct.
connect_info = objects.ConsoleAuthToken.validate(ctxt, token).to_dict()
valid_port = self._check_console_port(
ctxt, connect_info['instance_uuid'], connect_info['port'],
connect_info['console_type'])
if not valid_port:
raise exception.InvalidToken(token='***')
return connect_info
def _get_connect_info(self, ctxt, token):
"""Validate the token and get the connect info."""
connect_info = None
# NOTE(PaulMurray) if we are using cells v1, we use the old consoleauth
# way of doing things. The database backend is not supported for cells
# v1.
if CONF.cells.enable:
connect_info = self._get_connect_info_consoleauth(ctxt, token)
if not connect_info:
raise exception.InvalidToken(token='***')
else:
# NOTE(melwitt): If consoleauth is enabled to aid in transitioning
# to the database backend, check it first before falling back to
# the database. Tokens that existed pre-database-backend will
# reside in the consoleauth service storage.
if CONF.workarounds.enable_consoleauth:
connect_info = self._get_connect_info_consoleauth(ctxt, token)
# If consoleauth is enabled to aid in transitioning to the database
# backend and we didn't find a token in the consoleauth service
# storage, check the database for a token because it's probably a
# post-database-backend token, which are stored in the database.
if not connect_info:
connect_info = self._get_connect_info_database(ctxt, token)
return connect_info
def new_websocket_client(self):
"""Called after a new WebSocket connection has been established."""
# Reopen the eventlet hub to make sure we don't share an epoll
# fd with parent and/or siblings, which would be bad
from eventlet import hubs
hubs.use_hub()
# The nova expected behavior is to have token
# passed to the method GET of the request
parse = urlparse.urlparse(self.path)
if parse.scheme not in ('http', 'https'):
# From a bug in urlparse in Python < 2.7.4 we cannot support
# special schemes (cf: http://bugs.python.org/issue9374)
if sys.version_info < (2, 7, 4):
raise exception.NovaException(
_("We do not support scheme '%s' under Python < 2.7.4, "
"please use http or https") % parse.scheme)
query = parse.query
token = urlparse.parse_qs(query).get("token", [""]).pop()
if not token:
# NoVNC uses it's own convention that forward token
# from the request to a cookie header, we should check
# also for this behavior
hcookie = self.headers.get('cookie')
if hcookie:
cookie = Cookie.SimpleCookie()
for hcookie_part in hcookie.split(';'):
hcookie_part = hcookie_part.lstrip()
try:
cookie.load(hcookie_part)
except Cookie.CookieError:
# NOTE(stgleb): Do not print out cookie content
# for security reasons.
LOG.warning('Found malformed cookie')
else:
if 'token' in cookie:
token = cookie['token'].value
ctxt = context.get_admin_context()
connect_info = self._get_connect_info(ctxt, token)
# Verify Origin
expected_origin_hostname = self.headers.get('Host')
if ':' in expected_origin_hostname:
e = expected_origin_hostname
if '[' in e and ']' in e:
expected_origin_hostname = e.split(']')[0][1:]
else:
expected_origin_hostname = e.split(':')[0]
expected_origin_hostnames = CONF.console.allowed_origins
expected_origin_hostnames.append(expected_origin_hostname)
origin_url = self.headers.get('Origin')
# missing origin header indicates non-browser client which is OK
if origin_url is not None:
origin = urlparse.urlparse(origin_url)
origin_hostname = origin.hostname
origin_scheme = origin.scheme
# If the console connection was forwarded by a proxy (example:
# haproxy), the original protocol could be contained in the
# X-Forwarded-Proto header instead of the Origin header. Prefer the
# forwarded protocol if it is present.
forwarded_proto = self.headers.get('X-Forwarded-Proto')
if forwarded_proto is not None:
origin_scheme = forwarded_proto
if origin_hostname == '' or origin_scheme == '':
detail = _("Origin header not valid.")
raise exception.ValidationError(detail=detail)
if origin_hostname not in expected_origin_hostnames:
detail = _("Origin header does not match this host.")
raise exception.ValidationError(detail=detail)
if not self.verify_origin_proto(connect_info, origin_scheme):
detail = _("Origin header protocol does not match this host.")
raise exception.ValidationError(detail=detail)
sanitized_info = copy.copy(connect_info)
sanitized_info['token'] = '***'
self.msg(_('connect info: %s'), sanitized_info)
host = connect_info['host']
port = int(connect_info['port'])
# Connect to the target
self.msg(_("connecting to: %(host)s:%(port)s") % {'host': host,
'port': port})
tsock = self.socket(host, port, connect=True)
# Handshake as necessary
if connect_info.get('internal_access_path'):
tsock.send(encodeutils.safe_encode(
"CONNECT %s HTTP/1.1\r\n\r\n" %
connect_info['internal_access_path']))
end_token = "\r\n\r\n"
while True:
data = tsock.recv(4096, socket.MSG_PEEK)
token_loc = data.find(end_token)
if token_loc != -1:
if data.split("\r\n")[0].find("200") == -1:
raise exception.InvalidConnectionInfo()
# remove the response from recv buffer
tsock.recv(token_loc + len(end_token))
break
if self.server.security_proxy is not None:
tenant_sock = TenantSock(self)
try:
tsock = self.server.security_proxy.connect(tenant_sock, tsock)
except exception.SecurityProxyNegotiationFailed:
LOG.exception("Unable to perform security proxying, shutting "
"down connection")
tenant_sock.close()
tsock.shutdown(socket.SHUT_RDWR)
tsock.close()
raise
tenant_sock.finish_up()
# Start proxying
try:
self.do_proxy(tsock)
except Exception:
if tsock:
tsock.shutdown(socket.SHUT_RDWR)
tsock.close()
self.vmsg(_("%(host)s:%(port)s: "
"Websocket client or target closed") %
{'host': host, 'port': port})
raise
class NovaProxyRequestHandler(NovaProxyRequestHandlerBase,
websockify.ProxyRequestHandler):
def __init__(self, *args, **kwargs):
self._compute_rpcapi = None
websockify.ProxyRequestHandler.__init__(self, *args, **kwargs)
@property
def compute_rpcapi(self):
# Lazy load the rpcapi/ComputeAPI upon first use for this connection.
# This way, if we receive a TCP RST, we will not create a ComputeAPI
# object we won't use.
if not self._compute_rpcapi:
self._compute_rpcapi = compute_rpcapi.ComputeAPI()
return self._compute_rpcapi
def socket(self, *args, **kwargs):
return websockify.WebSocketServer.socket(*args, **kwargs)
class NovaWebSocketProxy(websockify.WebSocketProxy):
def __init__(self, *args, **kwargs):
""":param security_proxy: instance of
nova.console.securityproxy.base.SecurityProxy
Create a new web socket proxy, optionally using the
@security_proxy instance to negotiate security layer
with the compute node.
"""
self.security_proxy = kwargs.pop('security_proxy', None)
super(NovaWebSocketProxy, self).__init__(*args, **kwargs)
@staticmethod
def get_logger():
return LOG