| #!/usr/bin/python |
| |
| """Models wired and wireless interfaces.""" |
| |
| import logging |
| import os |
| import re |
| import subprocess |
| |
| import experiment |
| |
| METRIC_5GHZ = 20 |
| METRIC_24GHZ_5GHZ = 21 |
| METRIC_24GHZ = 22 |
| |
| RFC2385_MULTICAST_ROUTE = '239.0.0.0/8' |
| |
| experiment.register('WifiSimulateWireless') |
| CWMP_PATH = '/tmp/cwmp' |
| MAX_ACS_FAILURE_S = 60 |
| |
| |
| class Interface(object): |
| """Represents an interface. |
| |
| Base class for more specific interface types. |
| """ |
| |
| CONNECTION_CHECK = 'connection_check' |
| IP_ROUTE = ['ip', 'route'] |
| IP_ADDR_SHOW = ['ip', 'addr', 'show', 'dev'] |
| |
| def __init__(self, name, base_metric): |
| self.name = name |
| self.logger = logging.getLogger(self.name) |
| |
| # Currently connected links for this interface, e.g. ethernet. |
| self.links = set() |
| |
| # Whether [ACS, internet] access is currently available via this interface. |
| self._has_acs = None |
| self._has_internet = None |
| |
| self._subnet = None |
| self._gateway_ip = None |
| self.base_metric = base_metric |
| self.metric_offset = 0 |
| |
| # Until this is set True, the routing table will not be touched. |
| self._initialized = False |
| |
| @property |
| def metric(self): |
| return str(int(self.base_metric) + self.metric_offset) |
| |
| def _connection_check(self, check_acs): |
| """Check this interface's connection status. |
| |
| Args: |
| check_acs: If true, check for ACS access rather than internet access. |
| |
| Returns: |
| Whether the connection is working. |
| """ |
| # Until initialized, we want to act as if the interface is down. |
| if not self._initialized: |
| self.logger.info('not initialized; not running connection_check%s', |
| ' (ACS)' if check_acs else '') |
| return None |
| |
| if not self.links: |
| self.logger.info('Connection check failed due to no links') |
| return False |
| |
| self.logger.debug('Gateway IP is %s', self._gateway_ip) |
| if self._gateway_ip is None: |
| self.logger.info('Connection check%s failed due to no gateway IP', |
| ' (ACS)' if check_acs else '') |
| return False |
| |
| self.add_routes() |
| if 'default' not in self.current_routes(): |
| return False |
| |
| cmd = ['timeout', '5', self.CONNECTION_CHECK, '-I', self.name] |
| if check_acs: |
| cmd.append('-a') |
| |
| with open(os.devnull, 'w') as devnull: |
| result = subprocess.call(cmd, stdout=devnull, stderr=devnull) == 0 |
| self.logger.info('Connection check%s %s', |
| ' (ACS)' if check_acs else '', |
| 'passed' if result else 'failed') |
| |
| return result |
| |
| def gateway(self): |
| return self._gateway_ip |
| |
| def acs(self): |
| if self._has_acs is None: |
| self._has_acs = self._connection_check(check_acs=True) |
| |
| return self._has_acs |
| |
| def internet(self): |
| if self._has_internet is None: |
| self._has_internet = self._connection_check(check_acs=False) |
| |
| return self._has_internet |
| |
| def add_routes(self): |
| """Update default routes for this interface. |
| |
| Remove any stale routes and add any missing desired routes. |
| """ |
| if self.metric is None: |
| self.logger.info('Cannot add route without a metric.') |
| return |
| |
| # If the current routes are the same, there is nothing to do. If either |
| # exists but is different, delete it before adding an updated one. |
| current = self.current_routes() |
| |
| to_add = [] |
| |
| subnet = current.get('subnet', {}) |
| if self._subnet: |
| if ((subnet.get('route', None), subnet.get('metric', None)) != |
| (self._subnet, str(self.metric))): |
| self.logger.debug('Adding subnet route') |
| to_add.append(('subnet', ('add', self._subnet, 'dev', self.name, |
| 'metric', str(self.metric)))) |
| subnet = self._subnet |
| else: |
| subnet = None |
| self.delete_route('default', 'subnet') |
| |
| default = current.get('default', {}) |
| if self._gateway_ip: |
| if (subnet and |
| (default.get('via', None), default.get('metric', None)) != |
| (self._gateway_ip, str(self.metric))): |
| self.logger.debug('Adding default route') |
| to_add.append(('default', |
| ('add', 'default', 'via', self._gateway_ip, |
| 'dev', self.name, 'metric', str(self.metric)))) |
| else: |
| self.delete_route('default') |
| |
| # RFC2365 multicast route. |
| if current.get('multicast', {}).get('metric', None) != str(self.metric): |
| self.logger.debug('Adding multicast route') |
| to_add.append(('multicast', ('add', RFC2385_MULTICAST_ROUTE, |
| 'dev', self.name, |
| 'metric', str(self.metric)))) |
| |
| for route_type, _ in to_add[::-1]: |
| self.delete_route(route_type) |
| |
| for _, cmd in to_add: |
| self._ip_route(*cmd) |
| |
| def delete_route(self, *args): |
| """Delete default and/or subnet routes for this interface. |
| |
| Args: |
| *args: Which routes to delete. Must be at least one of 'default', |
| 'subnet', 'multicast'. |
| |
| Raises: |
| ValueError: If neither default nor subnet is True. |
| """ |
| args = set(args) |
| args &= set(('default', 'subnet', 'multicast')) |
| if not args: |
| raise ValueError( |
| 'Must specify at least one of default, subnet, multicast to delete.') |
| |
| # Use a sorted list to ensure that default comes before subnet. |
| for route_type in sorted(list(args)): |
| while route_type in self.current_routes(): |
| self.logger.debug('Deleting %s route', route_type) |
| self._ip_route('del', self.current_routes()[route_type]['route'], |
| 'dev', self.name) |
| |
| def current_routes(self): |
| """Read the current routes for this interface. |
| |
| Returns: |
| A dict mapping 'default' and/or 'subnet' to a dict containing the gateway |
| [and metric] of the route. Only contains keys for routes that are |
| present. |
| """ |
| result = {} |
| for line in self._ip_route().splitlines(): |
| if 'dev %s' % self.name in line: |
| if line.startswith('default'): |
| route_type = 'default' |
| elif re.search(r'/\d{1,2}$', line.split()[0]): |
| route_type = 'subnet' |
| else: |
| continue |
| route = {} |
| key = 'route' |
| for token in line.split(): |
| if token in ['via', 'metric']: |
| key = token |
| elif key: |
| if key == 'route' and token == RFC2385_MULTICAST_ROUTE: |
| route_type = 'multicast' |
| route[key] = token |
| key = None |
| if route: |
| result[route_type] = route |
| |
| return result |
| |
| def _ip_route(self, *args): |
| if not self._initialized: |
| self.logger.info('Not initialized, not running %s %s', |
| ' '.join(self.IP_ROUTE), ' '.join(args)) |
| return '' |
| |
| try: |
| self.logger.debug('calling ip route %s', ' '.join(args)) |
| return subprocess.check_output(self.IP_ROUTE + list(args)) |
| except subprocess.CalledProcessError as e: |
| self.logger.error('Failed to call "ip route" with args %r: %s', args, |
| e.message) |
| return '' |
| |
| def _ip_addr_show(self): |
| try: |
| return subprocess.check_output(self.IP_ADDR_SHOW + [self.name]) |
| except subprocess.CalledProcessError as e: |
| self.logger.error('Could not get IP address: %s', e.message) |
| return None |
| |
| def get_ip_address(self): |
| match = re.search(r'^\s*inet (?P<IP>\d+\.\d+\.\d+\.\d+)', |
| self._ip_addr_show(), re.MULTILINE) |
| return match and match.group('IP') or None |
| |
| def set_gateway_ip(self, gateway_ip): |
| self.logger.info('New gateway IP %s', gateway_ip) |
| self._gateway_ip = gateway_ip |
| self.update_routes(expire_cache=True) |
| |
| def set_subnet(self, subnet): |
| self.logger.info('New subnet %s', subnet) |
| self._subnet = subnet |
| self.update_routes(expire_cache=True) |
| |
| def _set_link_status(self, link, is_up): |
| """Set whether a link is up or not.""" |
| if is_up == (link in self.links): |
| return |
| |
| had_links = bool(self.links) |
| |
| if is_up: |
| self.logger.info('gained link %s', link) |
| self.links.add(link) |
| else: |
| self.logger.info('lost link %s', link) |
| self.links.remove(link) |
| |
| # If a link goes away, we may have lost access to something but not gained |
| # it, and vice versa. |
| if is_up != self._has_acs: |
| self._has_acs = None |
| |
| if is_up != self._has_internet: |
| self._has_internet = None |
| |
| if had_links != bool(self.links): |
| self.update_routes(expire_cache=False) |
| |
| def expire_connection_status_cache(self): |
| self.logger.debug('Expiring connection status cache') |
| self._has_internet = self._has_acs = None |
| |
| def update_routes(self, expire_cache=True): |
| """Update this interface's routes. |
| |
| If the interface has ACS or internet access, prioritize its routes. If it |
| doesn't but has a link, deprioritize the routes. If it has no links, delete |
| the routes. |
| |
| Args: |
| expire_cache: If true, force a recheck of connection status before |
| deciding how to prioritize routes. |
| """ |
| self.logger.debug('Updating routes') |
| if expire_cache: |
| self.expire_connection_status_cache() |
| |
| if self.acs() or self.internet(): |
| self.prioritize_routes() |
| else: |
| # If we still have a link, just deprioritize the routes, in case we're |
| # wrong about the connection check. If there's no actual link, then |
| # really delete the routes. |
| if self.links: |
| self.deprioritize_routes() |
| else: |
| self.delete_route('default', 'subnet', 'multicast') |
| |
| def prioritize_routes(self): |
| """When connection check succeeds, route priority (metric) should be normal. |
| |
| This is the inverse of deprioritize_routes. |
| """ |
| if not self._initialized: |
| return |
| self.logger.info('routes have normal priority') |
| self.metric_offset = 0 |
| self.add_routes() |
| |
| def deprioritize_routes(self): |
| """When connection check fails, deprioritize routes by increasing metric. |
| |
| This is conservative alternative to deleting routes, in case we are mistaken |
| about route not providing a useful connection. |
| """ |
| if not self._initialized: |
| return |
| self.logger.info('routes have low priority') |
| self.metric_offset = 50 |
| self.add_routes() |
| |
| def initialize(self): |
| """Tell the interface it has its initial state. |
| |
| Until this is called, the interface won't run connection checks or touch the |
| routing table. |
| """ |
| self._initialized = True |
| self.update_routes() |
| |
| |
| class Bridge(Interface): |
| """Represents the wired bridge.""" |
| |
| def __init__(self, *args, **kwargs): |
| self._acs_autoprovisioning_filepath = kwargs.pop( |
| 'acs_autoprovisioning_filepath') |
| super(Bridge, self).__init__(*args, **kwargs) |
| self._moca_stations = set() |
| |
| @property |
| def moca(self): |
| return bool(self._moca_stations) |
| |
| @moca.setter |
| def moca(self, is_up): |
| self._set_link_status('moca', is_up) |
| |
| @property |
| def ethernet(self): |
| return 'ethernet' in self.links |
| |
| @ethernet.setter |
| def ethernet(self, is_up): |
| self._set_link_status('ethernet', is_up) |
| |
| def add_moca_station(self, node_id): |
| if node_id not in self._moca_stations: |
| self._moca_stations.add(node_id) |
| self.moca = True |
| |
| def remove_moca_station(self, node_id): |
| if node_id in self._moca_stations: |
| self._moca_stations.remove(node_id) |
| self.moca = bool(self._moca_stations) |
| |
| def prioritize_routes(self): |
| """We only want ACS autoprovisioning when we're using a wired route.""" |
| super(Bridge, self).prioritize_routes() |
| open(self._acs_autoprovisioning_filepath, 'w') |
| |
| def deprioritize_routes(self, *args, **kwargs): |
| """We only want ACS autoprovisioning when we're using a wired route.""" |
| if os.path.exists(self._acs_autoprovisioning_filepath): |
| os.unlink(self._acs_autoprovisioning_filepath) |
| super(Bridge, self).deprioritize_routes(*args, **kwargs) |
| |
| def delete_route(self, *args, **kwargs): |
| """We only want ACS autoprovisioning when we're using a wired route.""" |
| if os.path.exists(self._acs_autoprovisioning_filepath): |
| os.unlink(self._acs_autoprovisioning_filepath) |
| super(Bridge, self).delete_route(*args, **kwargs) |
| |
| def _connection_check(self, check_acs): |
| """Support for WifiSimulateWireless.""" |
| failure_s = self._acs_session_failure_s() |
| if (experiment.enabled('WifiSimulateWireless') |
| and failure_s < MAX_ACS_FAILURE_S): |
| self.logger.info('WifiSimulateWireless: failing bridge connection check%s' |
| ' (no ACS contact for %d seconds, max %d seconds)', |
| ' (ACS)' if check_acs else '', failure_s, |
| MAX_ACS_FAILURE_S) |
| return False |
| |
| return super(Bridge, self)._connection_check(check_acs) |
| |
| def _acs_session_failure_s(self): |
| """How long have we been failing to connect to the ACS? |
| |
| Returns: |
| The number of seconds between the last attempted ACS session and the last |
| successful ACS session. |
| """ |
| contact = os.path.join(CWMP_PATH, 'acscontact') |
| connected = os.path.join(CWMP_PATH, 'acsconnected') |
| |
| if not os.path.exists(contact) or not os.path.exists(connected): |
| return 0 |
| |
| return os.stat(contact).st_mtime - os.stat(connected).st_mtime |
| |
| |
| class Wifi(Interface): |
| """Represents a wireless interface.""" |
| |
| def __init__(self, *args, **kwargs): |
| self.bands = kwargs.pop('bands', []) |
| super(Wifi, self).__init__(*args, **kwargs) |
| |
| @property |
| def wpa_supplicant(self): |
| self.update() |
| return 'wpa_supplicant' in self.links |
| |
| @wpa_supplicant.setter |
| def wpa_supplicant(self, is_up): |
| self._set_link_status('wpa_supplicant', is_up) |
| |
| def wpa_status(self): |
| """Parse the STATUS response from the wpa_supplicant control interface. |
| |
| Returns: |
| A dict containing the parsed results, where key and value are separated by |
| '=' on each line. |
| """ |
| status = {} |
| |
| try: |
| lines = subprocess.check_output(['wpa_cli', '-i', self.name, |
| 'status']).splitlines() |
| except subprocess.CalledProcessError: |
| self.logger.error('wpa_cli status request failed') |
| return {} |
| |
| for line in lines: |
| if '=' not in line: |
| continue |
| k, v = line.strip().split('=', 1) |
| status[k] = v |
| |
| return status |
| |
| def update(self): |
| self.wpa_supplicant = self.wpa_status().get('wpa_state', '') == 'COMPLETED' |
| |
| def connected_to_open(self): |
| status = self.wpa_status() |
| return (status.get('wpa_state', None) == 'COMPLETED' and |
| status.get('key_mgmt', None) == 'NONE') |
| |
| def current_secure_ssid(self): |
| """Returns SSID if connected to a secure network, False otherwise.""" |
| status = self.wpa_status() |
| return (status.get('wpa_state', None) == 'COMPLETED' and |
| # NONE indicates we're on a provisioning network; anything else |
| # suggests we're already on the WLAN. |
| status.get('key_mgmt', None) != 'NONE' and |
| status.get('ssid')) |
| |
| |
| class FrenzyWifi(Wifi): |
| """A WPACtrl for Frenzy devices. |
| |
| Implements the same functions used on the normal WPACtrl, using a combination |
| of the QCSAPI and wifi_files. Keeps state in order to generate events by |
| diffing saved state with current system state. |
| """ |
| |
| def _qcsapi(self, *command): |
| try: |
| return subprocess.check_output(['qcsapi'] + list(command)).strip() |
| except subprocess.CalledProcessError as e: |
| self.logger.error('QCSAPI call failed: %s: %s', e, e.output) |
| raise |
| |
| def wpa_status(self): |
| """Generate and cache events, update state.""" |
| try: |
| client_mode = self._qcsapi('get_mode', 'wifi0') == 'Station' |
| ssid = self._qcsapi('get_ssid', 'wifi0') |
| security = (self._qcsapi('ssid_get_authentication_mode', 'wifi0', ssid) |
| if ssid else None) |
| except subprocess.CalledProcessError: |
| # If QCSAPI failed, don't crash. |
| return {} |
| |
| up = bool(client_mode and ssid) |
| self.wpa_supplicant = up |
| |
| if up: |
| return { |
| 'wpa_state': 'COMPLETED', |
| 'ssid': ssid, |
| 'key_mgmt': security or 'NONE', |
| } |
| else: |
| return { |
| 'wpa_state': 'SCANNING', |
| } |
