Synnefo

# Copyright 2011-2012 GRNET S.A. All rights reserved.

#

# Redistribution and use in source and binary forms, with or

# without modification, are permitted provided that the following

# conditions are met:

#

#   1. Redistributions of source code must retain the above

#      copyright notice, this list of conditions and the following

#      disclaimer.

#

#   2. Redistributions in binary form must reproduce the above

#      copyright notice, this list of conditions and the following

#      disclaimer in the documentation and/or other materials

#      provided with the distribution.

#

# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR

# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

# POSSIBILITY OF SUCH DAMAGE.

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# The views and conclusions contained in the software and

# documentation are those of the authors and should not be

# interpreted as representing official policies, either expressed

# or implied, of GRNET S.A.

import logging

from time import time, mktime

from urlparse import urlparse, urlsplit, urlunsplit

from urllib import quote, unquote, urlencode

from django.conf import settings

from django.utils import simplejson as json

from django.utils.http import urlencode

from synnefo.lib.pool.http import get_http_connection

logger = logging.getLogger(__name__)

def retry(howmany):

    def execute(func):

        def f(*args, **kwargs):

            attempts = 0

            while True:

                try:

                    return func(*args, **kwargs)

                except Exception, e:

                    is_last_attempt = attempts == howmany - 1

                    if is_last_attempt:

                        raise e

                    if e.args:

                        status = e.args[-1]

                        # In case of Unauthorized response

                        # or Not Found return directly

                        if status == 401 or status == 404:

                            raise e

                    attempts += 1

        return f

    return execute

def call(token, url, headers={}, body=None, method='GET'):

    p = urlparse(url)

    kwargs = {}

    kwargs['headers'] = headers

    kwargs['headers']['X-Auth-Token'] = token

    if body:

        kwargs['body'] = body

        kwargs['headers'].setdefault('content-type', 'application/octet-stream')

    kwargs['headers'].setdefault('content-length', len(body) if body else 0)

    conn = get_http_connection(p.netloc, p.scheme)

    try:

        conn.request(method, p.path + '?' + p.query, **kwargs)

        response = conn.getresponse()

        headers = response.getheaders()

        headers = dict((unquote(h), unquote(v)) for h,v in headers)

        length = response.getheader('content-length', None)

        data = response.read(length)

        status = int(response.status)

    finally:

        conn.close()

    if status < 200 or status >= 300:

        raise Exception(data, status)

    return json.loads(data)

def authenticate(

        token, authentication_url='http://127.0.0.1:8000/im/authenticate',

        usage=False):

    if usage:

        authentication_url += "?usage=1"

    return call(token, authentication_url)

@retry(3)

def get_displaynames(

        token,

        uuids,

        url='http://127.0.0.1:8000/user_catalogs',

        override_users={}):

    if override_users:

        return dict((u,u) for u in uuids)

    try:

        data = call(

            token, url,  headers={'content-type':'application/json'},

            body=json.dumps({'uuids':uuids}), method='POST')

    except Exception, e:

        raise e

    else:

        return data.get('uuid_catalog')

@retry(3)

def get_uuids(

        token,

        displaynames,

        url='http://127.0.0.1:8000/user_catalogs',

        override_users={}):

    if override_users:

        return dict((u,u) for u in displaynames)

    try:

        data = call(

            token, url, headers={'content-type':'application/json'},

            body=json.dumps({'displaynames':displaynames}), method='POST')

    except Exception, e:

        import traceback

        traceback.print_exc()

        raise e

    else:

        return data.get('displayname_catalog')

def get_user_uuid(

        token,

        displayname,

        url='http://127.0.0.1:8000/user_catalogs',

        override_users={}):

    if not displayname:

        return

    displayname_dict = get_uuids(token, [displayname], url, override_users)

    return displayname_dict.get(displayname)

def get_displayname(

        token,

        uuid,

        url='http://127.0.0.1:8000/user_catalogs',

        override_users={}):

    if not uuid:

        return

    uuid_dict = get_displaynames(token, [uuid], url, override_users)

    return uuid_dict.get(uuid)

def user_for_token(token, authentication_url, override_users, usage=False):

    if not token:

        return None

    if override_users:

        try:

            return {'uuid': override_users[token].decode('utf8')}

        except:

            return None

    try:

        return authenticate(token, authentication_url, usage=usage)

    except Exception, e:

        # In case of Unauthorized response return None

        if e.args and e.args[-1] == 401:

            return None

        raise e

def get_user(

        request,

        authentication_url='http://127.0.0.1:8000/im/authenticate',

        override_users={},

        fallback_token=None,

        usage=False):

    request.user = None

    request.user_uniq = None

    # Try to find token in a parameter or in a request header.

    user = user_for_token(

        request.GET.get('X-Auth-Token'), authentication_url, override_users,

        usage=usage)

    if not user:

        user = user_for_token(

            request.META.get('HTTP_X_AUTH_TOKEN'),

            authentication_url,

            override_users,

            usage=usage)

    if not user:

        user = user_for_token(

            fallback_token, authentication_url, override_users,

            usage=usage)

    if not user:

        logger.warning("Cannot retrieve user details from %s",

                       authentication_url)

        return None

    # use user uuid, instead of email, keep email/displayname reference to user_id

    request.user_uniq = user['uuid']

    request.user = user

    request.user_id = user.get('displayname')

    return user

def get_token_from_cookie(request, cookiename):

    """

    Extract token from the cookie name provided. Cookie should be in the same

    form as astakos service sets its cookie contents::

        <user_uniq>|<user_token>

    """

    try:

        cookie_content = unquote(request.COOKIES.get(cookiename, None))

        return cookie_content.split("|")[1]

    except AttributeError:

        pass

    return None