remote_connection.py

# Licensed to the Software Freedom Conservancy (SFC) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The SFC licenses this file
# to you 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.

import logging
import socket
import string
import base64

try:
    import http.client as httplib
    from urllib import request as url_request
    from urllib import parse
except ImportError:  # above is available in py3+, below is py2.7
    import httplib as httplib
    import urllib2 as url_request
    import urlparse as parse

from selenium.webdriver.common import utils as common_utils
from .command import Command
from .errorhandler import ErrorCode
from . import utils

LOGGER = logging.getLogger(__name__)


class Request(url_request.Request):
    """
    Extends the url_request.Request to support all HTTP request types.
    """

    def __init__(self, url, data=None, method=None):
        """
        Initialise a new HTTP request.

        :Args:
            - url - String for the URL to send the request to.
            - data - Data to send with the request.
        """
        if method is None:
            method = data is not None and 'POST' or 'GET'
        elif method != 'POST' and method != 'PUT':
            data = None
        self._method = method
        url_request.Request.__init__(self, url, data=data)

    def get_method(self):
        """
        Returns the HTTP method used by this request.
        """
        return self._method


class Response(object):
    """
    Represents an HTTP response.
    """

    def __init__(self, fp, code, headers, url):
        """
        Initialise a new Response.

        :Args:
            - fp - The response body file object.
            - code - The HTTP status code returned by the server.
            - headers - A dictionary of headers returned by the server.
            - url - URL of the retrieved resource represented by this Response.
        """
        self.fp = fp
        self.read = fp.read
        self.code = code
        self.headers = headers
        self.url = url

    def close(self):
        """
        Close the response body file object.
        """
        self.read = None
        self.fp = None

    def info(self):
        """
        Returns the response headers.
        """
        return self.headers

    def geturl(self):
        """
        Returns the URL for the resource returned in this response.
        """
        return self.url


class HttpErrorHandler(url_request.HTTPDefaultErrorHandler):
    """
    A custom HTTP error handler.

    Used to return Response objects instead of raising an HTTPError exception.
    """

    def http_error_default(self, req, fp, code, msg, headers):
        """
        Default HTTP error handler.

        :Args:
            - req - The original Request object.
            - fp - The response body file object.
            - code - The HTTP status code returned by the server.
            - msg - The HTTP status message returned by the server.
            - headers - The response headers.

        :Returns:
            A new Response object.
        """
        return Response(fp, code, headers, req.get_full_url())


class RemoteConnection(object):
    """A connection with the Remote WebDriver server.

    Communicates with the server using the WebDriver wire protocol:
    https://github.com/SeleniumHQ/selenium/wiki/JsonWireProtocol"""

    _timeout = socket._GLOBAL_DEFAULT_TIMEOUT

    @classmethod
    def get_timeout(cls):
        """
        :Returns:
            Timeout value in seconds for all http requests made to the Remote Connection
        """
        return None if cls._timeout == socket._GLOBAL_DEFAULT_TIMEOUT else cls._timeout

    @classmethod
    def set_timeout(cls, timeout):
        """
        Override the default timeout

        :Args:
            - timeout - timeout value for http requests in seconds
        """
        cls._timeout = timeout

    @classmethod
    def reset_timeout(cls):
        """
        Reset the http request timeout to socket._GLOBAL_DEFAULT_TIMEOUT
        """
        cls._timeout = socket._GLOBAL_DEFAULT_TIMEOUT

    @classmethod
    def get_remote_connection_headers(cls, parsed_url, keep_alive=False):
        """
        Get headers for remote request.

        :Args:
         - parsed_url - The parsed url
         - keep_alive (Boolean) - Is this a keep-alive connection (default: False)
        """

        headers = {
            'Accept': 'application/json',
            'Content-Type': 'application/json;charset=UTF-8',
            'User-Agent': 'Python http auth'
        }

        if parsed_url.username:
            base64string = base64.b64encode('{0.username}:{0.password}'.format(parsed_url).encode())
            headers.update({
                'Authorization': 'Basic {}'.format(base64string.decode())
            })

        if keep_alive:
            headers.update({
                'Connection': 'keep-alive'
            })

        return headers

    def __init__(self, remote_server_addr, keep_alive=False, resolve_ip=True):
        # Attempt to resolve the hostname and get an IP address.
        self.keep_alive = keep_alive
        parsed_url = parse.urlparse(remote_server_addr)
        addr = parsed_url.hostname
        if parsed_url.hostname and resolve_ip:
            port = parsed_url.port or None
            if parsed_url.scheme == "https":
                ip = parsed_url.hostname
            elif port and not common_utils.is_connectable(port, parsed_url.hostname):
                ip = None
                LOGGER.info('Could not connect to port {} on host '
                            '{}'.format(port, parsed_url.hostname))
            else:
                ip = common_utils.find_connectable_ip(parsed_url.hostname,
                                                      port=port)
            if ip:
                netloc = ip
                addr = netloc
                if parsed_url.port:
                    netloc = common_utils.join_host_port(netloc,
                                                         parsed_url.port)
                if parsed_url.username:
                    auth = parsed_url.username
                    if parsed_url.password:
                        auth += ':%s' % parsed_url.password
                    netloc = '%s@%s' % (auth, netloc)
                remote_server_addr = parse.urlunparse(
                    (parsed_url.scheme, netloc, parsed_url.path,
                     parsed_url.params, parsed_url.query, parsed_url.fragment))
            else:
                LOGGER.info('Could not get IP address for host: %s' %
                            parsed_url.hostname)

        self._url = remote_server_addr
        if keep_alive:
            self._conn = httplib.HTTPConnection(
                str(addr), str(parsed_url.port), timeout=self._timeout)

        self._commands = {
            Command.STATUS: ('GET', '/status'),
            Command.NEW_SESSION: ('POST', '/session'),
            Command.GET_ALL_SESSIONS: ('GET', '/sessions'),
            Command.QUIT: ('DELETE', '/session/$sessionId'),
            Command.GET_CURRENT_WINDOW_HANDLE:
                ('GET', '/session/$sessionId/window_handle'),
            Command.W3C_GET_CURRENT_WINDOW_HANDLE:
                ('GET', '/session/$sessionId/window'),
            Command.GET_WINDOW_HANDLES:
                ('GET', '/session/$sessionId/window_handles'),
            Command.W3C_GET_WINDOW_HANDLES:
                ('GET', '/session/$sessionId/window/handles'),
            Command.GET: ('POST', '/session/$sessionId/url'),
            Command.GO_FORWARD: ('POST', '/session/$sessionId/forward'),
            Command.GO_BACK: ('POST', '/session/$sessionId/back'),
            Command.REFRESH: ('POST', '/session/$sessionId/refresh'),
            Command.EXECUTE_SCRIPT: ('POST', '/session/$sessionId/execute'),
            Command.W3C_EXECUTE_SCRIPT:
                ('POST', '/session/$sessionId/execute/sync'),
            Command.W3C_EXECUTE_SCRIPT_ASYNC:
                ('POST', '/session/$sessionId/execute/async'),
            Command.GET_CURRENT_URL: ('GET', '/session/$sessionId/url'),
            Command.GET_TITLE: ('GET', '/session/$sessionId/title'),
            Command.GET_PAGE_SOURCE: ('GET', '/session/$sessionId/source'),
            Command.SCREENSHOT: ('GET', '/session/$sessionId/screenshot'),
            Command.ELEMENT_SCREENSHOT: ('GET', '/session/$sessionId/element/$id/screenshot'),
            Command.FIND_ELEMENT: ('POST', '/session/$sessionId/element'),
            Command.FIND_ELEMENTS: ('POST', '/session/$sessionId/elements'),
            Command.W3C_GET_ACTIVE_ELEMENT: ('GET', '/session/$sessionId/element/active'),
            Command.GET_ACTIVE_ELEMENT:
                ('POST', '/session/$sessionId/element/active'),
            Command.FIND_CHILD_ELEMENT:
                ('POST', '/session/$sessionId/element/$id/element'),
            Command.FIND_CHILD_ELEMENTS:
                ('POST', '/session/$sessionId/element/$id/elements'),
            Command.CLICK_ELEMENT: ('POST', '/session/$sessionId/element/$id/click'),
            Command.CLEAR_ELEMENT: ('POST', '/session/$sessionId/element/$id/clear'),
            Command.SUBMIT_ELEMENT: ('POST', '/session/$sessionId/element/$id/submit'),
            Command.GET_ELEMENT_TEXT: ('GET', '/session/$sessionId/element/$id/text'),
            Command.SEND_KEYS_TO_ELEMENT:
                ('POST', '/session/$sessionId/element/$id/value'),
            Command.SEND_KEYS_TO_ACTIVE_ELEMENT:
                ('POST', '/session/$sessionId/keys'),
            Command.UPLOAD_FILE: ('POST', "/session/$sessionId/file"),
            Command.GET_ELEMENT_VALUE:
                ('GET', '/session/$sessionId/element/$id/value'),
            Command.GET_ELEMENT_TAG_NAME:
                ('GET', '/session/$sessionId/element/$id/name'),
            Command.IS_ELEMENT_SELECTED:
                ('GET', '/session/$sessionId/element/$id/selected'),
            Command.SET_ELEMENT_SELECTED:
                ('POST', '/session/$sessionId/element/$id/selected'),
            Command.IS_ELEMENT_ENABLED:
                ('GET', '/session/$sessionId/element/$id/enabled'),
            Command.IS_ELEMENT_DISPLAYED:
                ('GET', '/session/$sessionId/element/$id/displayed'),
            Command.GET_ELEMENT_LOCATION:
                ('GET', '/session/$sessionId/element/$id/location'),
            Command.GET_ELEMENT_LOCATION_ONCE_SCROLLED_INTO_VIEW:
                ('GET', '/session/$sessionId/element/$id/location_in_view'),
            Command.GET_ELEMENT_SIZE:
                ('GET', '/session/$sessionId/element/$id/size'),
            Command.GET_ELEMENT_RECT:
                ('GET', '/session/$sessionId/element/$id/rect'),
            Command.GET_ELEMENT_ATTRIBUTE:
                ('GET', '/session/$sessionId/element/$id/attribute/$name'),
            Command.GET_ELEMENT_PROPERTY:
                ('GET', '/session/$sessionId/element/$id/property/$name'),
            Command.ELEMENT_EQUALS:
                ('GET', '/session/$sessionId/element/$id/equals/$other'),
            Command.GET_ALL_COOKIES: ('GET', '/session/$sessionId/cookie'),
            Command.ADD_COOKIE: ('POST', '/session/$sessionId/cookie'),
            Command.DELETE_ALL_COOKIES:
                ('DELETE', '/session/$sessionId/cookie'),
            Command.DELETE_COOKIE:
                ('DELETE', '/session/$sessionId/cookie/$name'),
            Command.SWITCH_TO_FRAME: ('POST', '/session/$sessionId/frame'),
            Command.SWITCH_TO_PARENT_FRAME: ('POST', '/session/$sessionId/frame/parent'),
            Command.SWITCH_TO_WINDOW: ('POST', '/session/$sessionId/window'),
            Command.CLOSE: ('DELETE', '/session/$sessionId/window'),
            Command.GET_ELEMENT_VALUE_OF_CSS_PROPERTY:
                ('GET', '/session/$sessionId/element/$id/css/$propertyName'),
            Command.IMPLICIT_WAIT:
                ('POST', '/session/$sessionId/timeouts/implicit_wait'),
            Command.EXECUTE_ASYNC_SCRIPT: ('POST', '/session/$sessionId/execute_async'),
            Command.SET_SCRIPT_TIMEOUT:
                ('POST', '/session/$sessionId/timeouts/async_script'),
            Command.SET_TIMEOUTS:
                ('POST', '/session/$sessionId/timeouts'),
            Command.DISMISS_ALERT:
                ('POST', '/session/$sessionId/dismiss_alert'),
            Command.W3C_DISMISS_ALERT:
                ('POST', '/session/$sessionId/alert/dismiss'),
            Command.ACCEPT_ALERT:
                ('POST', '/session/$sessionId/accept_alert'),
            Command.W3C_ACCEPT_ALERT:
                ('POST', '/session/$sessionId/alert/accept'),
            Command.SET_ALERT_VALUE:
                ('POST', '/session/$sessionId/alert_text'),
            Command.W3C_SET_ALERT_VALUE:
                ('POST', '/session/$sessionId/alert/text'),
            Command.GET_ALERT_TEXT:
                ('GET', '/session/$sessionId/alert_text'),
            Command.W3C_GET_ALERT_TEXT:
                ('GET', '/session/$sessionId/alert/text'),
            Command.SET_ALERT_CREDENTIALS:
                ('POST', '/session/$sessionId/alert/credentials'),
            Command.CLICK:
                ('POST', '/session/$sessionId/click'),
            Command.W3C_ACTIONS:
                ('POST', '/session/$sessionId/actions'),
            Command.W3C_CLEAR_ACTIONS:
                ('DELETE', '/session/$sessionId/actions'),
            Command.DOUBLE_CLICK:
                ('POST', '/session/$sessionId/doubleclick'),
            Command.MOUSE_DOWN:
                ('POST', '/session/$sessionId/buttondown'),
            Command.MOUSE_UP:
                ('POST', '/session/$sessionId/buttonup'),
            Command.MOVE_TO:
                ('POST', '/session/$sessionId/moveto'),
            Command.GET_WINDOW_SIZE:
                ('GET', '/session/$sessionId/window/$windowHandle/size'),
            Command.SET_WINDOW_SIZE:
                ('POST', '/session/$sessionId/window/$windowHandle/size'),
            Command.GET_WINDOW_POSITION:
                ('GET', '/session/$sessionId/window/$windowHandle/position'),
            Command.SET_WINDOW_POSITION:
                ('POST', '/session/$sessionId/window/$windowHandle/position'),
            Command.SET_WINDOW_RECT:
                ('POST', '/session/$sessionId/window/rect'),
            Command.GET_WINDOW_RECT:
                ('GET', '/session/$sessionId/window/rect'),
            Command.MAXIMIZE_WINDOW:
                ('POST', '/session/$sessionId/window/$windowHandle/maximize'),
            Command.W3C_MAXIMIZE_WINDOW:
                ('POST', '/session/$sessionId/window/maximize'),
            Command.SET_SCREEN_ORIENTATION:
                ('POST', '/session/$sessionId/orientation'),
            Command.GET_SCREEN_ORIENTATION:
                ('GET', '/session/$sessionId/orientation'),
            Command.SINGLE_TAP:
                ('POST', '/session/$sessionId/touch/click'),
            Command.TOUCH_DOWN:
                ('POST', '/session/$sessionId/touch/down'),
            Command.TOUCH_UP:
                ('POST', '/session/$sessionId/touch/up'),
            Command.TOUCH_MOVE:
                ('POST', '/session/$sessionId/touch/move'),
            Command.TOUCH_SCROLL:
                ('POST', '/session/$sessionId/touch/scroll'),
            Command.DOUBLE_TAP:
                ('POST', '/session/$sessionId/touch/doubleclick'),
            Command.LONG_PRESS:
                ('POST', '/session/$sessionId/touch/longclick'),
            Command.FLICK:
                ('POST', '/session/$sessionId/touch/flick'),
            Command.EXECUTE_SQL:
                ('POST', '/session/$sessionId/execute_sql'),
            Command.GET_LOCATION:
                ('GET', '/session/$sessionId/location'),
            Command.SET_LOCATION:
                ('POST', '/session/$sessionId/location'),
            Command.GET_APP_CACHE:
                ('GET', '/session/$sessionId/application_cache'),
            Command.GET_APP_CACHE_STATUS:
                ('GET', '/session/$sessionId/application_cache/status'),
            Command.CLEAR_APP_CACHE:
                ('DELETE', '/session/$sessionId/application_cache/clear'),
            Command.GET_NETWORK_CONNECTION:
                ('GET', '/session/$sessionId/network_connection'),
            Command.SET_NETWORK_CONNECTION:
                ('POST', '/session/$sessionId/network_connection'),
            Command.GET_LOCAL_STORAGE_ITEM:
                ('GET', '/session/$sessionId/local_storage/key/$key'),
            Command.REMOVE_LOCAL_STORAGE_ITEM:
                ('DELETE', '/session/$sessionId/local_storage/key/$key'),
            Command.GET_LOCAL_STORAGE_KEYS:
                ('GET', '/session/$sessionId/local_storage'),
            Command.SET_LOCAL_STORAGE_ITEM:
                ('POST', '/session/$sessionId/local_storage'),
            Command.CLEAR_LOCAL_STORAGE:
                ('DELETE', '/session/$sessionId/local_storage'),
            Command.GET_LOCAL_STORAGE_SIZE:
                ('GET', '/session/$sessionId/local_storage/size'),
            Command.GET_SESSION_STORAGE_ITEM:
                ('GET', '/session/$sessionId/session_storage/key/$key'),
            Command.REMOVE_SESSION_STORAGE_ITEM:
                ('DELETE', '/session/$sessionId/session_storage/key/$key'),
            Command.GET_SESSION_STORAGE_KEYS:
                ('GET', '/session/$sessionId/session_storage'),
            Command.SET_SESSION_STORAGE_ITEM:
                ('POST', '/session/$sessionId/session_storage'),
            Command.CLEAR_SESSION_STORAGE:
                ('DELETE', '/session/$sessionId/session_storage'),
            Command.GET_SESSION_STORAGE_SIZE:
                ('GET', '/session/$sessionId/session_storage/size'),
            Command.GET_LOG:
                ('POST', '/session/$sessionId/log'),
            Command.GET_AVAILABLE_LOG_TYPES:
                ('GET', '/session/$sessionId/log/types'),
            Command.CURRENT_CONTEXT_HANDLE:
                ('GET', '/session/$sessionId/context'),
            Command.CONTEXT_HANDLES:
                ('GET', '/session/$sessionId/contexts'),
            Command.SWITCH_TO_CONTEXT:
                ('POST', '/session/$sessionId/context'),
            Command.FULLSCREEN_WINDOW:
                ('POST', '/session/$sessionId/window/fullscreen'),
            Command.MINIMIZE_WINDOW:
                ('POST', '/session/$sessionId/window/minimize')
        }

    def execute(self, command, params):
        """
        Send a command to the remote server.

        Any path subtitutions required for the URL mapped to the command should be
        included in the command parameters.

        :Args:
         - command - A string specifying the command to execute.
         - params - A dictionary of named parameters to send with the command as
           its JSON payload.
        """
        command_info = self._commands[command]
        assert command_info is not None, 'Unrecognised command %s' % command
        path = string.Template(command_info[1]).substitute(params)
        if hasattr(self, 'w3c') and self.w3c and isinstance(params, dict) and 'sessionId' in params:
            del params['sessionId']
        data = utils.dump_json(params)
        url = '%s%s' % (self._url, path)
        return self._request(command_info[0], url, body=data)

    def _request(self, method, url, body=None):
        """
        Send an HTTP request to the remote server.

        :Args:
         - method - A string for the HTTP method to send the request with.
         - url - A string for the URL to send the request to.
         - body - A string for request body. Ignored unless method is POST or PUT.

        :Returns:
          A dictionary with the server's parsed JSON response.
        """
        LOGGER.debug('%s %s %s' % (method, url, body))

        parsed_url = parse.urlparse(url)
        headers = self.get_remote_connection_headers(parsed_url, self.keep_alive)

        if self.keep_alive:
            if body and method != 'POST' and method != 'PUT':
                body = None
            try:
                self._conn.request(method, parsed_url.path, body, headers)
                resp = self._conn.getresponse()
            except (httplib.HTTPException, socket.error):
                self._conn.close()
                raise

            statuscode = resp.status
        else:
            password_manager = None
            if parsed_url.username:
                netloc = parsed_url.hostname
                if parsed_url.port:
                    netloc += ":%s" % parsed_url.port
                cleaned_url = parse.urlunparse((
                    parsed_url.scheme,
                    netloc,
                    parsed_url.path,
                    parsed_url.params,
                    parsed_url.query,
                    parsed_url.fragment))
                password_manager = url_request.HTTPPasswordMgrWithDefaultRealm()
                password_manager.add_password(None,
                                              "%s://%s" % (parsed_url.scheme, netloc),
                                              parsed_url.username,
                                              parsed_url.password)
                request = Request(cleaned_url, data=body.encode('utf-8'), method=method)
            else:
                request = Request(url, data=body.encode('utf-8'), method=method)

            for key, val in headers.items():
                request.add_header(key, val)

            if password_manager:
                opener = url_request.build_opener(url_request.HTTPRedirectHandler(),
                                                  HttpErrorHandler(),
                                                  url_request.HTTPBasicAuthHandler(password_manager))
            else:
                opener = url_request.build_opener(url_request.HTTPRedirectHandler(),
                                                  HttpErrorHandler())
            resp = opener.open(request, timeout=self._timeout)
            statuscode = resp.code
            if not hasattr(resp, 'getheader'):
                if hasattr(resp.headers, 'getheader'):
                    resp.getheader = lambda x: resp.headers.getheader(x)
                elif hasattr(resp.headers, 'get'):
                    resp.getheader = lambda x: resp.headers.get(x)

        data = resp.read()
        try:
            if 300 <= statuscode < 304:
                return self._request('GET', resp.getheader('location'))
            body = data.decode('utf-8').replace('\x00', '').strip()
            if 399 < statuscode <= 500:
                return {'status': statuscode, 'value': body}
            content_type = []
            if resp.getheader('Content-Type') is not None:
                content_type = resp.getheader('Content-Type').split(';')
            if not any([x.startswith('image/png') for x in content_type]):
                try:
                    data = utils.load_json(body.strip())
                except ValueError:
                    if 199 < statuscode < 300:
                        status = ErrorCode.SUCCESS
                    else:
                        status = ErrorCode.UNKNOWN_ERROR
                    return {'status': status, 'value': body.strip()}

                assert type(data) is dict, (
                    'Invalid server response body: %s' % body)
                # Some of the drivers incorrectly return a response
                # with no 'value' field when they should return null.
                if 'value' not in data:
                    data['value'] = None
                return data
            else:
                data = {'status': 0, 'value': body.strip()}
                return data
        finally:
            LOGGER.debug("Finished Request")
            resp.close()