class EnforcementController(PolicyMixin, RestartMixin, MagmaController):
"""
EnforcementController
The enforcement controller installs flows for policy enforcement and
classification. Each flow installed matches on a rule and an IMSI and then
classifies the packet with the rule. The flow also redirects and drops
the packet as specified in the policy.
NOTE: Enforcement currently relies on the fact that policies do not
overlap. In this implementation, there is the idea of a 'default rule'
which is the catch-all. This rule is treated specially and tagged with a
specific priority.
"""
APP_NAME = "enforcement"
APP_TYPE = ControllerType.LOGICAL
DEFAULT_FLOW_COOKIE = 0xfffffffffffffffe
def __init__(self, *args, **kwargs):
super(EnforcementController, self).__init__(*args, **kwargs)
self._config = kwargs['config']
self.tbl_num = self._service_manager.get_table_num(self.APP_NAME)
self.next_main_table = self._service_manager.get_next_table_num(
EnforcementStatsController.APP_NAME)
self._enforcement_stats_tbl = self._service_manager.get_table_num(
EnforcementStatsController.APP_NAME)
self.loop = kwargs['loop']
self._msg_hub = MessageHub(self.logger)
self._redirect_scratch = \
self._service_manager.allocate_scratch_tables(self.APP_NAME, 1)[0]
self._bridge_ip_address = kwargs['config']['bridge_ip_address']
self._redirect_manager = None
self._qos_mgr = None
self._clean_restart = kwargs['config']['clean_restart']
self._redirect_manager = RedirectionManager(
self._bridge_ip_address, self.logger, self.tbl_num,
self._enforcement_stats_tbl, self.next_main_table,
self._redirect_scratch, self._session_rule_version_mapper)
def initialize_on_connect(self, datapath):
"""
Install the default flows on datapath connect event.
Args:
datapath: ryu datapath struct
"""
self._datapath = datapath
self._qos_mgr = QosManager.get_qos_manager(datapath, self.loop,
self._config)
def cleanup_on_disconnect(self, datapath):
"""
Cleanup flows on datapath disconnect event.
Args:
datapath: ryu datapath struct
"""
if self._clean_restart:
self.delete_all_flows(datapath)
def delete_all_flows(self, datapath):
flows.delete_all_flows_from_table(datapath, self.tbl_num)
flows.delete_all_flows_from_table(datapath, self._redirect_scratch)
def cleanup_state(self):
pass
@set_ev_cls(ofp_event.EventOFPBarrierReply, MAIN_DISPATCHER)
def _handle_barrier(self, ev):
self._msg_hub.handle_barrier(ev)
@set_ev_cls(ofp_event.EventOFPErrorMsg, MAIN_DISPATCHER)
def _handle_error(self, ev):
self._msg_hub.handle_error(ev)
@set_ev_cls(ofp_event.EventOFPMeterConfigStatsReply, MAIN_DISPATCHER)
def meter_config_stats_reply_handler(self, ev):
if not self._qos_mgr:
return
qos_impl = self._qos_mgr.impl
if qos_impl and isinstance(qos_impl, MeterManager):
qos_impl.handle_meter_config_stats(ev.msg.body)
@set_ev_cls(ofp_event.EventOFPMeterFeaturesStatsReply, MAIN_DISPATCHER)
def meter_features_stats_reply_handler(self, ev):
if not self._qos_mgr:
return
qos_impl = self._qos_mgr.impl
if qos_impl and isinstance(qos_impl, MeterManager):
qos_impl.handle_meter_feature_stats(ev.msg.body)
def _get_default_flow_msgs(self, datapath) -> DefaultMsgsMap:
"""
Gets the default flow msg that forward to stats table(traffic will be
dropped because stats table doesn't forward anything)
Args:
datapath: ryu datapath struct
Returns:
The list of default msgs to add
"""
match = MagmaMatch()
msg = flows.get_add_resubmit_next_service_flow_msg(
datapath,
self.tbl_num,
match, [],
priority=flows.MINIMUM_PRIORITY,
resubmit_table=self._enforcement_stats_tbl,
cookie=self.DEFAULT_FLOW_COOKIE)
return {self.tbl_num: [msg]}
def _get_rule_match_flow_msgs(self, imsi, msisdn: bytes,
uplink_tunnel: int, ip_addr, apn_ambr, rule):
"""
Get flow msgs to get stats for a particular rule. Flows will match on
IMSI, cookie (the rule num), in/out direction
Args:
imsi (string): subscriber to install rule for
msisdn (bytes): subscriber MSISDN
uplink_tunnel (int): tunnel ID of the subscriber.
ip_addr (string): subscriber session ipv4 address
rule (PolicyRule): policy rule proto
"""
rule_num = self._rule_mapper.get_or_create_rule_num(rule.id)
priority = Utils.get_of_priority(rule.priority)
flow_adds = []
for flow in rule.flow_list:
try:
version = self._session_rule_version_mapper.get_version(
imsi, ip_addr, rule.id)
flow_adds.extend(
self._get_classify_rule_flow_msgs(
imsi, msisdn, uplink_tunnel, ip_addr, apn_ambr, flow,
rule_num, priority, rule.qos, rule.hard_timeout,
rule.id, rule.app_name, rule.app_service_type,
self.next_main_table, version, self._qos_mgr,
self._enforcement_stats_tbl, rule.he.urls))
except FlowMatchError as err: # invalid match
self.logger.error(
"Failed to get flow msg '%s' for subscriber %s: %s",
rule.id, imsi, err)
raise err
return flow_adds
def _install_flow_for_rule(self, imsi, msisdn: bytes, uplink_tunnel: int,
ip_addr, apn_ambr, rule):
"""
Install a flow to get stats for a particular rule. Flows will match on
IMSI, cookie (the rule num), in/out direction
Args:
imsi (string): subscriber to install rule for
msisdn (bytes): subscriber MSISDN
uplink_tunnel (int): tunnel ID of the subscriber.
ip_addr (string): subscriber session ipv4 address
rule (PolicyRule): policy rule proto
"""
if rule.redirect.support == rule.redirect.ENABLED:
return self._install_redirect_flow(imsi, ip_addr, rule)
if not rule.flow_list:
self.logger.error(
'The flow list for imsi %s, rule.id - %s'
'is empty, this shoudn\'t happen', imsi, rule.id)
return RuleModResult.FAILURE
flow_adds = []
try:
flow_adds = self._get_rule_match_flow_msgs(imsi, msisdn,
uplink_tunnel, ip_addr,
apn_ambr, rule)
except FlowMatchError:
return RuleModResult.FAILURE
try:
chan = self._msg_hub.send(flow_adds, self._datapath)
except MagmaDPDisconnectedError:
self.logger.error(
"Datapath disconnected, failed to install rule %s"
"for imsi %s", rule, imsi)
return RuleModResult.FAILURE
return self._wait_for_rule_responses(imsi, ip_addr, rule, chan)
def _install_redirect_flow(self, imsi, ip_addr, rule):
rule_num = self._rule_mapper.get_or_create_rule_num(rule.id)
rule_version = self._session_rule_version_mapper.get_version(
imsi, ip_addr, rule.id)
priority = Utils.get_of_priority(rule.priority)
redirect_request = RedirectionManager.RedirectRequest(
imsi=imsi,
ip_addr=ip_addr.address.decode('utf-8'),
rule=rule,
rule_num=rule_num,
rule_version=rule_version,
priority=priority)
try:
self._redirect_manager.setup_lte_redirect(self._datapath,
self.loop,
redirect_request)
return RuleModResult.SUCCESS
except RedirectException as err:
self.logger.error(
'Redirect Exception for imsi %s, rule.id - %s : %s', imsi,
rule.id, err)
return RuleModResult.FAILURE
def _get_default_flow_msgs_for_subscriber(self, *_):
pass
def _install_default_flow_for_subscriber(self, *_):
pass
def _deactivate_flow_for_rule(self, imsi, ip_addr, rule_id):
"""
Deactivate a specific rule using the flow cookie for a subscriber
"""
try:
num = self._rule_mapper.get_rule_num(rule_id)
except KeyError:
self.logger.error('Could not find rule id %s', rule_id)
return
if num is None:
self.logger.error('Rule num is None for rule %s', rule_id)
return
cookie, mask = (num, flows.OVS_COOKIE_MATCH_ALL)
ip_match_in = get_ue_ip_match_args(ip_addr, Direction.IN)
match = MagmaMatch(eth_type=get_eth_type(ip_addr),
imsi=encode_imsi(imsi),
**ip_match_in)
flows.delete_flow(self._datapath,
self.tbl_num,
match,
cookie=cookie,
cookie_mask=mask)
ip_match_out = get_ue_ip_match_args(ip_addr, Direction.OUT)
match = MagmaMatch(eth_type=get_eth_type(ip_addr),
imsi=encode_imsi(imsi),
**ip_match_out)
flows.delete_flow(self._datapath,
self.tbl_num,
match,
cookie=cookie,
cookie_mask=mask)
self._redirect_manager.deactivate_flow_for_rule(
self._datapath, imsi, num)
self._qos_mgr.remove_subscriber_qos(imsi, num)
self._remove_he_flows(ip_addr, rule_id, num)
def _deactivate_flows_for_subscriber(self, imsi, ip_addr):
""" Deactivate all rules for specified subscriber session """
ip_match_in = get_ue_ip_match_args(ip_addr, Direction.IN)
match = MagmaMatch(eth_type=get_eth_type(ip_addr),
imsi=encode_imsi(imsi),
**ip_match_in)
flows.delete_flow(self._datapath, self.tbl_num, match)
ip_match_out = get_ue_ip_match_args(ip_addr, Direction.OUT)
match = MagmaMatch(eth_type=get_eth_type(ip_addr),
imsi=encode_imsi(imsi),
**ip_match_out)
flows.delete_flow(self._datapath, self.tbl_num, match)
self._redirect_manager.deactivate_flows_for_subscriber(
self._datapath, imsi)
self._qos_mgr.remove_subscriber_qos(imsi)
self._remove_he_flows(ip_addr)
def deactivate_rules(self, imsi, ip_addr, rule_ids):
"""
Deactivate flows for a subscriber.
Only imsi -> remove all rules for imsi
imsi+ipv4 -> remove all rules for imsi session
imsi+rule_ids -> remove specific rules for imsi (for all sessions)
imsi+ipv4+rule_ids -> remove rules for specific imsi session
Args:
imsi (string): subscriber id
ip_addr (string): subscriber ip address
rule_ids (list of strings): policy rule ids
"""
if not self.init_finished:
self.logger.error('Pipelined is not initialized')
return RuleModResult.FAILURE
if self._datapath is None:
self.logger.error('Datapath not initialized')
return
if not imsi:
self.logger.error('No subscriber specified')
return
if not rule_ids:
self._deactivate_flows_for_subscriber(imsi, ip_addr)
else:
for rule_id in rule_ids:
self._deactivate_flow_for_rule(imsi, ip_addr, rule_id)
def recover_state(self, _):
pass
class GYController(PolicyMixin, MagmaController):
"""
GYController
The GY controller installs flows for enforcement of GY final actions, this
includes redirection and QoS(currently not supported)
"""
APP_NAME = "gy"
APP_TYPE = ControllerType.LOGICAL
def __init__(self, *args, **kwargs):
super(GYController, self).__init__(*args, **kwargs)
self._config = kwargs['config']
self.tbl_num = self._service_manager.get_table_num(self.APP_NAME)
self.next_main_table = self._service_manager.get_next_table_num(
self.APP_NAME)
self.next_service_table = self._service_manager.get_next_table_num(
EnforcementStatsController.APP_NAME)
self._enforcement_stats_tbl = self._service_manager.get_table_num(
EnforcementStatsController.APP_NAME)
self.loop = kwargs['loop']
self._msg_hub = MessageHub(self.logger)
self._internal_ip_allocator = kwargs['internal_ip_allocator']
self._redirect_scratch = \
self._service_manager.allocate_scratch_tables(self.APP_NAME, 2)[0]
self._mac_rewr = \
self._service_manager.INTERNAL_MAC_IP_REWRITE_TBL_NUM
self._bridge_ip_address = kwargs['config']['bridge_ip_address']
self._clean_restart = kwargs['config']['clean_restart']
self._qos_mgr = None
self._setup_type = self._config['setup_type']
self._redirect_manager = \
RedirectionManager(
self._bridge_ip_address,
self.logger,
self.tbl_num,
self._service_manager.get_table_num(EGRESS),
self._redirect_scratch,
self._session_rule_version_mapper
)
if self._setup_type == 'CWF':
self._redirect_manager.set_cwf_args(
internal_ip_allocator=kwargs['internal_ip_allocator'],
arp=kwargs['app_futures']['arpd'],
mac_rewrite=self._mac_rewr,
bridge_name=kwargs['config']['bridge_name'],
egress_table=self._service_manager.get_table_num(EGRESS)
)
def initialize_on_connect(self, datapath):
"""
Install the default flows on datapath connect event.
Args:
datapath: ryu datapath struct
"""
self._datapath = datapath
self._qos_mgr = QosManager(datapath, self.loop, self._config)
self._qos_mgr.setup()
self._delete_all_flows(datapath)
self._install_default_flows(datapath)
def deactivate_rules(self, imsi, ip_addr, rule_ids):
"""
Deactivate flows for a subscriber. If only imsi is present, delete all
rule flows for a subscriber (i.e. end its session). If rule_ids are
present, delete the rule flows for that subscriber.
Args:
imsi (string): subscriber id
rule_ids (list of strings): policy rule ids
"""
if not self.init_finished:
self.logger.error('Pipelined is not initialized')
return RuleModResult.FAILURE
if self._datapath is None:
self.logger.error('Datapath not initialized')
return
if not imsi:
self.logger.error('No subscriber specified')
return
if not rule_ids:
self._deactivate_flows_for_subscriber(imsi, ip_addr)
else:
for rule_id in rule_ids:
self._deactivate_flow_for_rule(imsi, ip_addr, rule_id)
def cleanup_state(self):
pass
def _deactivate_flows_for_subscriber(self, imsi, ip_addr):
"""
Deactivate all rules for a subscriber, ending any enforcement
Args:
imsi (string): subscriber id
ip_addr(IPAddress): session IP address
"""
match = MagmaMatch(imsi=encode_imsi(imsi))
flows.delete_flow(self._datapath, self.tbl_num, match)
self._redirect_manager.deactivate_flows_for_subscriber(self._datapath,
imsi)
self._qos_mgr.remove_subscriber_qos(imsi)
self._remove_he_flows(ip_addr, None)
def _deactivate_flow_for_rule(self, imsi, ip_addr, rule_id):
"""
Deactivate a specific rule using the flow cookie for a subscriber
Args:
imsi (string): subscriber id
rule_id (string): policy rule id
"""
try:
num = self._rule_mapper.get_rule_num(rule_id)
except KeyError:
self.logger.error('Could not find rule id %s', rule_id)
return
cookie, mask = (num, flows.OVS_COOKIE_MATCH_ALL)
match = MagmaMatch(imsi=encode_imsi(imsi))
flows.delete_flow(self._datapath, self.tbl_num, match,
cookie=cookie, cookie_mask=mask)
self._redirect_manager.deactivate_flow_for_rule(self._datapath, imsi,
num)
self._qos_mgr.remove_subscriber_qos(imsi, num)
self._remove_he_flows(ip_addr, rule_id)
def _install_flow_for_rule(self, imsi, msisdn:bytes, uplink_tunnel: int, ip_addr, apn_ambr, rule):
"""
Install a flow to get stats for a particular rule. Flows will match on
IMSI, cookie (the rule num), in/out direction
Args:
imsi (string): subscriber to install rule for
ip_addr (string): subscriber session ipv4 address
apn_ambr (integer): maximum bandwidth for non-GBR EPS bearers
rule (PolicyRule): policy rule proto
"""
if rule.redirect.support == rule.redirect.ENABLED:
self._install_redirect_flow(imsi, ip_addr, rule)
return RuleModResult.SUCCESS
if not rule.flow_list:
self.logger.error('The flow list for imsi %s, rule.id - %s'
'is empty, this shoudn\'t happen', imsi, rule.id)
return RuleModResult.FAILURE
flow_adds = []
try:
flow_adds = self._get_rule_match_flow_msgs(imsi, msisdn, uplink_tunnel, ip_addr, apn_ambr, rule)
except FlowMatchError:
return RuleModResult.FAILURE
chan = self._msg_hub.send(flow_adds, self._datapath)
return self._wait_for_rule_responses(imsi, ip_addr, rule, chan)
def _get_default_flow_msgs_for_subscriber(self, *_):
return None
def _install_default_flow_for_subscriber(self, *_):
pass
def _delete_all_flows(self, datapath):
flows.delete_all_flows_from_table(datapath, self.tbl_num)
flows.delete_all_flows_from_table(datapath, self._redirect_scratch)
flows.delete_all_flows_from_table(datapath, self._mac_rewr)
def _install_default_flows(self, datapath):
"""
For each direction set the default flows to just forward to next app.
The enforcement flows for each subscriber would be added when the
IP session is created, by reaching out to the controller/PCRF.
Args:
datapath: ryu datapath struct
"""
match = MagmaMatch()
flows.add_resubmit_next_service_flow(
datapath, self.tbl_num, match, [],
priority=flows.MINIMUM_PRIORITY,
resubmit_table=self.next_main_table)
def _install_redirect_flow(self, imsi, ip_addr, rule):
rule_num = self._rule_mapper.get_or_create_rule_num(rule.id)
rule_version = self._session_rule_version_mapper.get_version(imsi,
ip_addr,
rule.id)
priority = rule.priority
# TODO currently if redirection is enabled we ignore other flows
# from rule.flow_list, confirm that this is the expected behaviour
redirect_request = RedirectionManager.RedirectRequest(
imsi=imsi,
ip_addr=ip_addr.address.decode('utf-8'),
rule=rule,
rule_num=rule_num,
rule_version=rule_version,
priority=priority)
try:
if self._setup_type == 'CWF':
self._redirect_manager.setup_cwf_redirect(
self._datapath, self.loop, redirect_request)
else:
self._redirect_manager.setup_lte_redirect(
self._datapath, self.loop, redirect_request)
return RuleModResult.SUCCESS
except RedirectException as err:
self.logger.error(
'Redirect Exception for imsi %s, rule.id - %s : %s',
imsi, rule.id, err
)
return RuleModResult.FAILURE
def _install_default_flows_if_not_installed(self, datapath,
existing_flows: List[OFPFlowStats]) -> List[OFPFlowStats]:
"""
For each direction set the default flows to just forward to next app.
The enforcement flows for each subscriber would be added when the
IP session is created, by reaching out to the controller/PCRF.
If default flows are already installed, do nothing.
Args:
datapath: ryu datapath struct
Returns:
The list of flows that remain after inserting default flows
"""
match = MagmaMatch()
msg = flows.get_add_resubmit_next_service_flow_msg(
datapath, self.tbl_num, match, [],
priority=flows.MINIMUM_PRIORITY,
resubmit_table=self.next_main_table)
msgs, remaining_flows = self._msg_hub \
.filter_msgs_if_not_in_flow_list([msg], existing_flows)
if msgs:
chan = self._msg_hub.send(msgs, datapath)
self._wait_for_responses(chan, len(msgs))
return remaining_flows
def _get_rule_match_flow_msgs(self, imsi, msisdn: bytes, uplink_tunnel: int, ip_addr, apn_ambr, rule):
"""
Get flow msgs to get stats for a particular rule. Flows will match on
IMSI, cookie (the rule num), in/out direction
Args:
imsi (string): subscriber to install rule for
msisdn (bytes): subscriber ISDN
ip_addr (string): subscriber session ipv4 address
apn_ambr (integer): maximum bandwidth for non-GBR EPS bearers
rule (PolicyRule): policy rule proto
"""
rule_num = self._rule_mapper.get_or_create_rule_num(rule.id)
priority = Utils.get_of_priority(rule.priority)
flow_adds = []
for flow in rule.flow_list:
try:
version = self._session_rule_version_mapper.get_version(imsi, ip_addr,
rule.id)
flow_adds.extend(self._get_classify_rule_flow_msgs(
imsi, msisdn, uplink_tunnel, ip_addr, apn_ambr, flow, rule_num, priority,
rule.qos, rule.hard_timeout, rule.id, rule.app_name,
rule.app_service_type, self.next_service_table,
version, self._qos_mgr, self._enforcement_stats_tbl))
except FlowMatchError as err: # invalid match
self.logger.error(
"Failed to get flow msg '%s' for subscriber %s: %s",
rule.id, imsi, err)
raise err
return flow_adds
@set_ev_cls(ofp_event.EventOFPMeterConfigStatsReply, MAIN_DISPATCHER)
def meter_config_stats_reply_handler(self, ev):
if not self._qos_mgr:
return
qos_impl = self._qos_mgr.impl
if qos_impl and isinstance(qos_impl, MeterManager):
qos_impl.handle_meter_config_stats(ev.msg.body)
@set_ev_cls(ofp_event.EventOFPMeterFeaturesStatsReply, MAIN_DISPATCHER)
def meter_features_stats_reply_handler(self, ev):
if not self._qos_mgr:
return
qos_impl = self._qos_mgr.impl
if qos_impl and isinstance(qos_impl, MeterManager):
qos_impl.handle_meter_feature_stats(ev.msg.body)
@set_ev_cls(ofp_event.EventOFPBarrierReply, MAIN_DISPATCHER)
def _handle_barrier(self, ev):
self._msg_hub.handle_barrier(ev)
@set_ev_cls(ofp_event.EventOFPErrorMsg, MAIN_DISPATCHER)
def _handle_error(self, ev):
self._msg_hub.handle_error(ev)
class EnforcementController(PolicyMixin, MagmaController):
"""
EnforcementController
The enforcement controller installs flows for policy enforcement and
classification. Each flow installed matches on a rule and an IMSI and then
classifies the packet with the rule. The flow also redirects and drops
the packet as specified in the policy.
NOTE: Enforcement currently relies on the fact that policies do not
overlap. In this implementation, there is the idea of a 'default rule'
which is the catch-all. This rule is treated specially and tagged with a
specific priority.
"""
APP_NAME = "enforcement"
APP_TYPE = ControllerType.LOGICAL
def __init__(self, *args, **kwargs):
super(EnforcementController, self).__init__(*args, **kwargs)
self._config = kwargs['config']
self.tbl_num = self._service_manager.get_table_num(self.APP_NAME)
self.next_main_table = self._service_manager.get_next_table_num(
self.APP_NAME)
self._enforcement_stats_tbl = self._service_manager.get_table_num(
EnforcementStatsController.APP_NAME)
self.loop = kwargs['loop']
self._msg_hub = MessageHub(self.logger)
self._redirect_scratch = \
self._service_manager.allocate_scratch_tables(self.APP_NAME, 1)[0]
self._bridge_ip_address = kwargs['config']['bridge_ip_address']
self._redirect_manager = None
self._qos_mgr = None
self._clean_restart = kwargs['config']['clean_restart']
self._redirect_manager = RedirectionManager(
self._bridge_ip_address,
self.logger,
self.tbl_num,
self._enforcement_stats_tbl,
self._redirect_scratch,
self._session_rule_version_mapper)
def initialize_on_connect(self, datapath):
"""
Install the default flows on datapath connect event.
Args:
datapath: ryu datapath struct
"""
self._datapath = datapath
self._qos_mgr = QosManager(datapath, self.loop, self._config)
self._qos_mgr.setup()
def cleanup_on_disconnect(self, datapath):
"""
Cleanup flows on datapath disconnect event.
Args:
datapath: ryu datapath struct
"""
if self._clean_restart:
self.delete_all_flows(datapath)
def delete_all_flows(self, datapath):
flows.delete_all_flows_from_table(datapath, self.tbl_num)
flows.delete_all_flows_from_table(datapath, self._redirect_scratch)
def cleanup_state(self):
pass
@set_ev_cls(ofp_event.EventOFPBarrierReply, MAIN_DISPATCHER)
def _handle_barrier(self, ev):
self._msg_hub.handle_barrier(ev)
@set_ev_cls(ofp_event.EventOFPErrorMsg, MAIN_DISPATCHER)
def _handle_error(self, ev):
self._msg_hub.handle_error(ev)
@set_ev_cls(ofp_event.EventOFPMeterConfigStatsReply, MAIN_DISPATCHER)
def meter_config_stats_reply_handler(self, ev):
if not self._qos_mgr:
return
qos_impl = self._qos_mgr.impl
if qos_impl and isinstance(qos_impl, MeterManager):
qos_impl.handle_meter_config_stats(ev.msg.body)
@set_ev_cls(ofp_event.EventOFPMeterFeaturesStatsReply, MAIN_DISPATCHER)
def meter_features_stats_reply_handler(self, ev):
if not self._qos_mgr:
return
qos_impl = self._qos_mgr.impl
if qos_impl and isinstance(qos_impl, MeterManager):
qos_impl.handle_meter_feature_stats(ev.msg.body)
def _install_default_flows_if_not_installed(self, datapath,
existing_flows: List[OFPFlowStats]) -> List[OFPFlowStats]:
"""
For each direction set the default flows to just forward to next app.
The enforcement flows for each subscriber would be added when the
IP session is created, by reaching out to the controller/PCRF.
If default flows are already installed, do nothing.
Args:
datapath: ryu datapath struct
Returns:
The list of flows that remain after inserting default flows
"""
inbound_match = MagmaMatch(eth_type=ether_types.ETH_TYPE_IP,
direction=Direction.IN)
outbound_match = MagmaMatch(eth_type=ether_types.ETH_TYPE_IP,
direction=Direction.OUT)
inbound_msg = flows.get_add_resubmit_next_service_flow_msg(
datapath, self.tbl_num, inbound_match, [],
priority=flows.MINIMUM_PRIORITY,
resubmit_table=self.next_main_table)
outbound_msg = flows.get_add_resubmit_next_service_flow_msg(
datapath, self.tbl_num, outbound_match, [],
priority=flows.MINIMUM_PRIORITY,
resubmit_table=self.next_main_table)
msgs, remaining_flows = self._msg_hub \
.filter_msgs_if_not_in_flow_list([inbound_msg, outbound_msg],
existing_flows)
if msgs:
chan = self._msg_hub.send(msgs, datapath)
self._wait_for_responses(chan, len(msgs))
return remaining_flows
def _get_rule_match_flow_msgs(self, imsi, ip_addr, apn_ambr, rule):
"""
Get flow msgs to get stats for a particular rule. Flows will match on
IMSI, cookie (the rule num), in/out direction
Args:
imsi (string): subscriber to install rule for
ip_addr (string): subscriber session ipv4 address
rule (PolicyRule): policy rule proto
"""
rule_num = self._rule_mapper.get_or_create_rule_num(rule.id)
priority = Utils.get_of_priority(rule.priority)
flow_adds = []
for flow in rule.flow_list:
try:
version = self._session_rule_version_mapper.get_version(imsi, ip_addr,
rule.id)
flow_adds.extend(self._get_classify_rule_flow_msgs(
imsi, ip_addr, apn_ambr, flow, rule_num, priority,
rule.qos, rule.hard_timeout, rule.id, rule.app_name,
rule.app_service_type, self._enforcement_stats_tbl,
version, self._qos_mgr))
except FlowMatchError as err: # invalid match
self.logger.error(
"Failed to get flow msg '%s' for subscriber %s: %s",
rule.id, imsi, err)
raise err
return flow_adds
def _install_flow_for_rule(self, imsi, ip_addr, apn_ambr, rule):
"""
Install a flow to get stats for a particular rule. Flows will match on
IMSI, cookie (the rule num), in/out direction
Args:
imsi (string): subscriber to install rule for
ip_addr (string): subscriber session ipv4 address
rule (PolicyRule): policy rule proto
"""
if rule.redirect.support == rule.redirect.ENABLED:
return self._install_redirect_flow(imsi, ip_addr, rule)
if not rule.flow_list:
self.logger.error('The flow list for imsi %s, rule.id - %s'
'is empty, this shoudn\'t happen', imsi, rule.id)
return RuleModResult.FAILURE
flow_adds = []
try:
flow_adds = self._get_rule_match_flow_msgs(imsi, ip_addr, apn_ambr, rule)
except FlowMatchError:
return RuleModResult.FAILURE
chan = self._msg_hub.send(flow_adds, self._datapath)
return self._wait_for_rule_responses(imsi, rule, chan)
def _install_redirect_flow(self, imsi, ip_addr, rule):
rule_num = self._rule_mapper.get_or_create_rule_num(rule.id)
rule_version = self._session_rule_version_mapper.get_version(imsi,
ip_addr,
rule.id)
priority = Utils.get_of_priority(rule.priority)
redirect_request = RedirectionManager.RedirectRequest(
imsi=imsi,
ip_addr=ip_addr.address.decode('utf-8'),
rule=rule,
rule_num=rule_num,
rule_version=rule_version,
priority=priority)
try:
self._redirect_manager.setup_lte_redirect(
self._datapath, self.loop, redirect_request)
return RuleModResult.SUCCESS
except RedirectException as err:
self.logger.error(
'Redirect Exception for imsi %s, rule.id - %s : %s',
imsi, rule.id, err
)
return RuleModResult.FAILURE
def _get_default_flow_msgs_for_subscriber(self, imsi, ip_addr):
ip_match_in = get_ue_ip_match_args(ip_addr, Direction.IN)
match_in = MagmaMatch(eth_type=get_eth_type(ip_addr),
imsi=encode_imsi(imsi), **ip_match_in)
ip_match_out = get_ue_ip_match_args(ip_addr, Direction.OUT)
match_out = MagmaMatch(eth_type=get_eth_type(ip_addr),
imsi=encode_imsi(imsi), **ip_match_out)
actions = []
return [
flows.get_add_drop_flow_msg(
self._datapath, self.tbl_num, match_in, actions,
priority=Utils.DROP_PRIORITY),
flows.get_add_drop_flow_msg(
self._datapath, self.tbl_num, match_out, actions,
priority=Utils.DROP_PRIORITY)]
def _install_default_flow_for_subscriber(self, imsi, ip_addr):
"""
Add a low priority flow to drop a subscriber's traffic in the event
that all rules have been deactivated.
Args:
imsi (string): subscriber id
"""
msgs = self._get_default_flow_msgs_for_subscriber(imsi, ip_addr)
if msgs:
chan = self._msg_hub.send(msgs, self._datapath)
self._wait_for_responses(chan, len(msgs))
def _deactivate_flow_for_rule(self, imsi, ip_addr, rule_id):
"""
Deactivate a specific rule using the flow cookie for a subscriber
"""
try:
num = self._rule_mapper.get_rule_num(rule_id)
except KeyError:
self.logger.error('Could not find rule id %s', rule_id)
return
cookie, mask = (num, flows.OVS_COOKIE_MATCH_ALL)
ip_match_in = get_ue_ip_match_args(ip_addr, Direction.IN)
match = MagmaMatch(eth_type=get_eth_type(ip_addr),
imsi=encode_imsi(imsi), **ip_match_in)
flows.delete_flow(self._datapath, self.tbl_num, match,
cookie=cookie, cookie_mask=mask)
ip_match_out = get_ue_ip_match_args(ip_addr, Direction.OUT)
match = MagmaMatch(eth_type=get_eth_type(ip_addr),
imsi=encode_imsi(imsi), **ip_match_out)
flows.delete_flow(self._datapath, self.tbl_num, match,
cookie=cookie, cookie_mask=mask)
self._redirect_manager.deactivate_flow_for_rule(self._datapath, imsi,
num)
self._qos_mgr.remove_subscriber_qos(imsi, num)
def _deactivate_flows_for_subscriber(self, imsi, ip_addr):
""" Deactivate all rules for specified subscriber session """
ip_match_in = get_ue_ip_match_args(ip_addr, Direction.IN)
match = MagmaMatch(eth_type=get_eth_type(ip_addr),
imsi=encode_imsi(imsi), **ip_match_in)
flows.delete_flow(self._datapath, self.tbl_num, match)
ip_match_out = get_ue_ip_match_args(ip_addr, Direction.OUT)
match = MagmaMatch(eth_type=get_eth_type(ip_addr),
imsi=encode_imsi(imsi), **ip_match_out)
flows.delete_flow(self._datapath, self.tbl_num, match)
self._redirect_manager.deactivate_flows_for_subscriber(self._datapath,
imsi)
self._qos_mgr.remove_subscriber_qos(imsi)
def deactivate_rules(self, imsi, ip_addr, rule_ids):
"""
Deactivate flows for a subscriber.
Only imsi -> remove all rules for imsi
imsi+ipv4 -> remove all rules for imsi session
imsi+rule_ids -> remove specific rules for imsi (for all sessions)
imsi+ipv4+rule_ids -> remove rules for specific imsi session
Args:
imsi (string): subscriber id
ip_addr (string): subscriber ip address
rule_ids (list of strings): policy rule ids
"""
if not self.init_finished:
self.logger.error('Pipelined is not initialized')
return RuleModResult.FAILURE
if self._datapath is None:
self.logger.error('Datapath not initialized')
return
if not imsi:
self.logger.error('No subscriber specified')
return
if not rule_ids:
self._deactivate_flows_for_subscriber(imsi, ip_addr)
else:
for rule_id in rule_ids:
self._deactivate_flow_for_rule(imsi, ip_addr, rule_id)