VOL-1227 Clean up, constants and exceptions handling
Change-Id: I99e60f52dac2238e1651fbfd94981e24f0dc0707
diff --git a/voltha/adapters/openolt/openolt_flow_mgr.py b/voltha/adapters/openolt/openolt_flow_mgr.py
index 692f639..c1ee458 100644
--- a/voltha/adapters/openolt/openolt_flow_mgr.py
+++ b/voltha/adapters/openolt/openolt_flow_mgr.py
@@ -32,9 +32,7 @@
DHCP_FLOW_INDEX = 1 # FIXME
DHCP_DOWNLINK_FLOW_INDEX = 6 # FIXME
EAPOL_FLOW_INDEX = 2 # FIXME
-EAPOL_DOWNLINK_FLOW_INDEX = 3 # FIXME
-EAPOL_DOWNLINK_SECONDARY_FLOW_INDEX = 4 # FIXME
-EAPOL_UPLINK_SECONDARY_FLOW_INDEX = 5 # FIXME
+EAPOL_SECONDARY_FLOW_INDEX = 5 # FIXME
LLDP_FLOW_INDEX = 7 # FIXME
EAP_ETH_TYPE = 0x888e
@@ -44,6 +42,35 @@
DEFAULT_MGMT_VLAN = 4091
+# Openolt Flow
+UPSTREAM = 'upstream'
+DOWNSTREAM = 'downstream'
+PACKET_TAG_TYPE = 'pkt_tag_type'
+UNTAGGED = 'untagged'
+SINGLE_TAG = 'single_tag'
+DOUBLE_TAG = 'double_tag'
+
+# Classifier
+ETH_TYPE = 'eth_type'
+TPID = 'tpid'
+IP_PROTO = 'ip_proto'
+IN_PORT = 'in_port'
+VLAN_VID = 'vlan_vid'
+VLAN_PCP = 'vlan_pcp'
+UDP_DST = 'udp_dst'
+UDP_SRC = 'udp_src'
+IPV4_DST = 'ipv4_dst'
+IPV4_SRC = 'ipv4_src'
+METADATA = 'metadata'
+OUTPUT = 'output'
+# Action
+POP_VLAN = 'pop_vlan'
+PUSH_VLAN = 'push_vlan'
+TRAP_TO_HOST = 'trap_to_host'
+
+
+
+
class OpenOltFlowMgr(object):
def __init__(self, log, stub, device_id, logical_device_id, resource_mgr):
@@ -65,68 +92,67 @@
for field in fd.get_ofb_fields(flow):
if field.type == fd.ETH_TYPE:
- classifier_info['eth_type'] = field.eth_type
+ classifier_info[ETH_TYPE] = field.eth_type
self.log.debug('field-type-eth-type',
- eth_type=classifier_info['eth_type'])
+ eth_type=classifier_info[ETH_TYPE])
elif field.type == fd.IP_PROTO:
- classifier_info['ip_proto'] = field.ip_proto
+ classifier_info[IP_PROTO] = field.ip_proto
self.log.debug('field-type-ip-proto',
- ip_proto=classifier_info['ip_proto'])
+ ip_proto=classifier_info[IP_PROTO])
elif field.type == fd.IN_PORT:
- classifier_info['in_port'] = field.port
+ classifier_info[IN_PORT] = field.port
self.log.debug('field-type-in-port',
- in_port=classifier_info['in_port'])
+ in_port=classifier_info[IN_PORT])
elif field.type == fd.VLAN_VID:
- classifier_info['vlan_vid'] = field.vlan_vid & 0xfff
+ classifier_info[VLAN_VID] = field.vlan_vid & 0xfff
self.log.debug('field-type-vlan-vid',
- vlan=classifier_info['vlan_vid'])
+ vlan=classifier_info[VLAN_VID])
elif field.type == fd.VLAN_PCP:
- classifier_info['vlan_pcp'] = field.vlan_pcp
+ classifier_info[VLAN_PCP] = field.vlan_pcp
self.log.debug('field-type-vlan-pcp',
- pcp=classifier_info['vlan_pcp'])
+ pcp=classifier_info[VLAN_PCP])
elif field.type == fd.UDP_DST:
- classifier_info['udp_dst'] = field.udp_dst
+ classifier_info[UDP_DST] = field.udp_dst
self.log.debug('field-type-udp-dst',
- udp_dst=classifier_info['udp_dst'])
+ udp_dst=classifier_info[UDP_DST])
elif field.type == fd.UDP_SRC:
- classifier_info['udp_src'] = field.udp_src
+ classifier_info[UDP_SRC] = field.udp_src
self.log.debug('field-type-udp-src',
- udp_src=classifier_info['udp_src'])
+ udp_src=classifier_info[UDP_SRC])
elif field.type == fd.IPV4_DST:
- classifier_info['ipv4_dst'] = field.ipv4_dst
+ classifier_info[IPV4_DST] = field.ipv4_dst
self.log.debug('field-type-ipv4-dst',
- ipv4_dst=classifier_info['ipv4_dst'])
+ ipv4_dst=classifier_info[IPV4_DST])
elif field.type == fd.IPV4_SRC:
- classifier_info['ipv4_src'] = field.ipv4_src
+ classifier_info[IPV4_SRC] = field.ipv4_src
self.log.debug('field-type-ipv4-src',
- ipv4_dst=classifier_info['ipv4_src'])
+ ipv4_dst=classifier_info[IPV4_SRC])
elif field.type == fd.METADATA:
- classifier_info['metadata'] = field.table_metadata
+ classifier_info[METADATA] = field.table_metadata
self.log.debug('field-type-metadata',
- metadata=classifier_info['metadata'])
+ metadata=classifier_info[METADATA])
else:
raise NotImplementedError('field.type={}'.format(
field.type))
for action in fd.get_actions(flow):
if action.type == fd.OUTPUT:
- action_info['output'] = action.output.port
+ action_info[OUTPUT] = action.output.port
self.log.debug('action-type-output',
- output=action_info['output'],
- in_port=classifier_info['in_port'])
+ output=action_info[OUTPUT],
+ in_port=classifier_info[IN_PORT])
elif action.type == fd.POP_VLAN:
if fd.get_goto_table_id(flow) is None:
self.log.debug('being taken care of by ONU', flow=flow)
return
- action_info['pop_vlan'] = True
+ action_info[POP_VLAN] = True
self.log.debug('action-type-pop-vlan',
- in_port=classifier_info['in_port'])
+ in_port=classifier_info[IN_PORT])
elif action.type == fd.PUSH_VLAN:
- action_info['push_vlan'] = True
- action_info['tpid'] = action.push.ethertype
+ action_info[PUSH_VLAN] = True
+ action_info[TPID] = action.push.ethertype
self.log.debug('action-type-push-vlan',
- push_tpid=action_info['tpid'],
- in_port=classifier_info['in_port'])
+ push_tpid=action_info[TPID], in_port=classifier_info[IN_PORT])
if action.push.ethertype != 0x8100:
self.log.error('unhandled-tpid',
ethertype=action.push.ethertype)
@@ -135,37 +161,38 @@
_field = action.set_field.field.ofb_field
assert (action.set_field.field.oxm_class ==
OFPXMC_OPENFLOW_BASIC)
- self.log.debug('action-type-set-field', field=_field,
- in_port=classifier_info['in_port'])
+ self.log.debug('action-type-set-field',
+ field=_field, in_port=classifier_info[IN_PORT])
if _field.type == fd.VLAN_VID:
self.log.debug('set-field-type-vlan-vid',
vlan_vid=_field.vlan_vid & 0xfff)
- action_info['vlan_vid'] = (_field.vlan_vid & 0xfff)
+ action_info[VLAN_VID] = (_field.vlan_vid & 0xfff)
else:
self.log.error('unsupported-action-set-field-type',
field_type=_field.type)
else:
self.log.error('unsupported-action-type',
- action_type=action.type,
- in_port=classifier_info['in_port'])
+ action_type=action.type, in_port=classifier_info[IN_PORT])
- if fd.get_goto_table_id(flow) is not None and not 'pop_vlan' in \
+ if fd.get_goto_table_id(flow) is not None and not POP_VLAN in \
action_info:
self.log.debug('being taken care of by ONU', flow=flow)
return
- if not 'output' in action_info and 'metadata' in classifier_info:
- # find flow in the next table
+ if not OUTPUT in action_info and METADATA in classifier_info:
+ #find flow in the next table
next_flow = self.find_next_flow(flow)
if next_flow is None:
return
- action_info['output'] = fd.get_out_port(next_flow)
+ action_info[OUTPUT] = fd.get_out_port(next_flow)
for field in fd.get_ofb_fields(next_flow):
if field.type == fd.VLAN_VID:
- classifier_info['metadata'] = field.vlan_vid & 0xfff
+ classifier_info[METADATA] = field.vlan_vid & 0xfff
+
(intf_id, onu_id) = platform.extract_access_from_flow(
- classifier_info['in_port'], action_info['output'])
+ classifier_info[IN_PORT], action_info[OUTPUT])
+
self.divide_and_add_flow(intf_id, onu_id, classifier_info,
action_info, flow)
@@ -219,37 +246,38 @@
self.log.debug('sorting flow', intf_id=intf_id, onu_id=onu_id,
classifier=classifier, action=action)
- if 'ip_proto' in classifier:
- if classifier['ip_proto'] == 17:
+ if IP_PROTO in classifier:
+ if classifier[IP_PROTO] == 17:
self.log.debug('dhcp flow add')
yield self.add_dhcp_trap(intf_id, onu_id, classifier,
action, flow)
- elif classifier['ip_proto'] == 2:
+ elif classifier[IP_PROTO] == 2:
self.log.warn('igmp flow add ignored, not implemented yet')
else:
self.log.warn("Invalid-Classifier-to-handle",
- classifier=classifier,
- action=action)
- elif 'eth_type' in classifier:
- if classifier['eth_type'] == EAP_ETH_TYPE:
+ classifier=classifier,
+ action=action)
+ elif ETH_TYPE in classifier:
+ if classifier[ETH_TYPE] == EAP_ETH_TYPE:
self.log.debug('eapol flow add')
yield self.add_eapol_flow(intf_id, onu_id, flow)
vlan_id = self.get_subscriber_vlan(fd.get_in_port(flow))
if vlan_id is not None:
yield self.add_eapol_flow(
intf_id, onu_id, flow,
- uplink_eapol_id=EAPOL_UPLINK_SECONDARY_FLOW_INDEX,
- downlink_eapol_id=EAPOL_DOWNLINK_SECONDARY_FLOW_INDEX,
+ eapol_id=EAPOL_SECONDARY_FLOW_INDEX,
vlan_id=vlan_id)
- if classifier['eth_type'] == LLDP_ETH_TYPE:
+ if classifier[ETH_TYPE] == LLDP_ETH_TYPE:
self.log.debug('lldp flow add')
yield self.add_lldp_flow(intf_id, onu_id, flow, classifier,
action)
- elif 'push_vlan' in action:
- yield self.add_upstream_data_flow(intf_id, onu_id, classifier, action,
+
+ elif PUSH_VLAN in action:
+ yield self.add_upstream_data_flow(intf_id, onu_id, classifier,
+ action,
flow)
- elif 'pop_vlan' in action:
+ elif POP_VLAN in action:
yield self.add_downstream_data_flow(intf_id, onu_id, classifier,
action, flow)
else:
@@ -261,30 +289,33 @@
def add_upstream_data_flow(self, intf_id, onu_id, uplink_classifier,
uplink_action, logical_flow):
- uplink_classifier['pkt_tag_type'] = 'single_tag'
+
+ uplink_classifier[PACKET_TAG_TYPE] = SINGLE_TAG
+
yield self.add_hsia_flow(intf_id, onu_id, uplink_classifier,
- uplink_action, 'upstream', HSIA_FLOW_INDEX,
+ uplink_action, UPSTREAM, HSIA_FLOW_INDEX,
logical_flow)
# Secondary EAP on the subscriber vlan
(eap_active, eap_logical_flow) = self.is_eap_enabled(intf_id, onu_id)
if eap_active:
+
yield self.add_eapol_flow(intf_id, onu_id, eap_logical_flow,
- uplink_eapol_id=EAPOL_UPLINK_SECONDARY_FLOW_INDEX,
- downlink_eapol_id=EAPOL_DOWNLINK_SECONDARY_FLOW_INDEX,
- vlan_id=uplink_classifier['vlan_vid'])
+ eapol_id=EAPOL_SECONDARY_FLOW_INDEX,
+ vlan_id=uplink_classifier[VLAN_VID])
+
@inlineCallbacks
def add_downstream_data_flow(self, intf_id, onu_id, downlink_classifier,
downlink_action, flow):
- downlink_classifier['pkt_tag_type'] = 'double_tag'
+ downlink_classifier[PACKET_TAG_TYPE] = DOUBLE_TAG
# Needed ???? It should be already there
- downlink_action['pop_vlan'] = True
- downlink_action['vlan_vid'] = downlink_classifier['vlan_vid']
+ downlink_action[POP_VLAN] = True
+ downlink_action[VLAN_VID] = downlink_classifier[VLAN_VID]
yield self.add_hsia_flow(intf_id, onu_id, downlink_classifier,
- downlink_action, 'downstream', HSIA_FLOW_INDEX,
+ downlink_action, DOWNSTREAM, HSIA_FLOW_INDEX,
flow)
# To-Do right now only one GEM port is supported, so below method
@@ -322,9 +353,9 @@
action=action)
action.clear()
- action['trap_to_host'] = True
- classifier['pkt_tag_type'] = 'single_tag'
- classifier.pop('vlan_vid', None)
+ action[TRAP_TO_HOST] = True
+ classifier[PACKET_TAG_TYPE] = SINGLE_TAG
+ classifier.pop(VLAN_VID, None)
pon_intf_onu_id = (intf_id, onu_id)
gemport_id = yield self.resource_mgr.get_gemport_id(
@@ -336,7 +367,7 @@
flow_id = platform.mk_flow_id(intf_id, onu_id, DHCP_FLOW_INDEX)
upstream_flow = openolt_pb2.Flow(
- onu_id=onu_id, flow_id=flow_id, flow_type="upstream",
+ onu_id=onu_id, flow_id=flow_id, flow_type=UPSTREAM,
access_intf_id=intf_id, gemport_id=gemport_id,
alloc_id=alloc_id,
priority=logical_flow.priority,
@@ -354,16 +385,16 @@
oxm_field.ofb_field.port = \
platform.intf_id_to_port_no(0, Port.ETHERNET_NNI)
- classifier['udp_src'] = 67
- classifier['udp_dst'] = 68
- classifier['pkt_tag_type'] = 'double_tag'
- action.pop('push_vlan', None)
+ classifier[UDP_SRC] = 67
+ classifier[UDP_DST] = 68
+ classifier[PACKET_TAG_TYPE] = DOUBLE_TAG
+ action.pop(PUSH_VLAN, None)
flow_id = platform.mk_flow_id(intf_id, onu_id,
DHCP_DOWNLINK_FLOW_INDEX)
downstream_flow = openolt_pb2.Flow(
- onu_id=onu_id, flow_id=flow_id, flow_type="downstream",
+ onu_id=onu_id, flow_id=flow_id, flow_type=DOWNSTREAM,
access_intf_id=intf_id, network_intf_id=0, gemport_id=gemport_id,
priority=logical_flow.priority, classifier=self.mk_classifier(
classifier),
@@ -373,19 +404,18 @@
@inlineCallbacks
def add_eapol_flow(self, intf_id, onu_id, logical_flow,
- uplink_eapol_id=EAPOL_FLOW_INDEX,
- downlink_eapol_id=EAPOL_DOWNLINK_FLOW_INDEX,
+ eapol_id=EAPOL_FLOW_INDEX,
vlan_id=DEFAULT_MGMT_VLAN):
uplink_classifier = {}
- uplink_classifier['eth_type'] = EAP_ETH_TYPE
- uplink_classifier['pkt_tag_type'] = 'single_tag'
- uplink_classifier['vlan_vid'] = vlan_id
+ uplink_classifier[ETH_TYPE] = EAP_ETH_TYPE
+ uplink_classifier[PACKET_TAG_TYPE] = SINGLE_TAG
+ uplink_classifier[VLAN_VID] = vlan_id
uplink_action = {}
- uplink_action['trap_to_host'] = True
+ uplink_action[TRAP_TO_HOST] = True
pon_intf_onu_id = (intf_id, onu_id)
gemport_id = yield self.resource_mgr.get_gemport_id(
@@ -397,10 +427,10 @@
# Add Upstream EAPOL Flow.
- uplink_flow_id = platform.mk_flow_id(intf_id, onu_id, uplink_eapol_id)
+ uplink_flow_id = platform.mk_flow_id(intf_id, onu_id, eapol_id)
upstream_flow = openolt_pb2.Flow(
- onu_id=onu_id, flow_id=uplink_flow_id, flow_type="upstream",
+ onu_id=onu_id, flow_id=uplink_flow_id, flow_type=UPSTREAM,
access_intf_id=intf_id, gemport_id=gemport_id,
alloc_id=alloc_id,
priority=logical_flow.priority,
@@ -416,23 +446,24 @@
if vlan_id == DEFAULT_MGMT_VLAN:
- # Add Downstream EAPOL Flow, Only for first EAP flow
+ # Add Downstream EAPOL Flow, Only for first EAP flow (BAL
+ # requirement)
+ special_vlan_downstream_flow = 4000 - onu_id
downlink_classifier = {}
- downlink_classifier['pkt_tag_type'] = 'single_tag'
- downlink_classifier['vlan_vid'] = 4000 - onu_id
-
+ downlink_classifier[PACKET_TAG_TYPE] = SINGLE_TAG
+ downlink_classifier[VLAN_VID] = special_vlan_downstream_flow
downlink_action = {}
- downlink_action['push_vlan'] = True
- downlink_action['vlan_vid'] = vlan_id
+ downlink_action[PUSH_VLAN] = True
+ downlink_action[VLAN_VID] = vlan_id
downlink_flow_id = platform.mk_flow_id(intf_id, onu_id,
- downlink_eapol_id)
+ eapol_id)
downstream_flow = openolt_pb2.Flow(
- onu_id=onu_id, flow_id=downlink_flow_id, flow_type="downstream",
+ onu_id=onu_id, flow_id=downlink_flow_id, flow_type=DOWNSTREAM,
access_intf_id=intf_id, gemport_id=gemport_id,
priority=logical_flow.priority,
classifier=self.mk_classifier(downlink_classifier),
@@ -444,7 +475,7 @@
downstream_logical_flow.match.oxm_fields.extend(fd.mk_oxm_fields([
fd.in_port(fd.get_out_port(logical_flow)),
- fd.vlan_vid((4000 - onu_id) | 0x1000)]))
+ fd.vlan_vid((special_vlan_downstream_flow) | 0x1000)]))
downstream_logical_flow.match.type = OFPMT_OXM
downstream_logical_flow.instructions.extend(
@@ -476,8 +507,8 @@
action=action)
action.clear()
- action['trap_to_host'] = True
- classifier['pkt_tag_type'] = 'untagged'
+ action[TRAP_TO_HOST] = True
+ classifier[PACKET_TAG_TYPE] = UNTAGGED
pon_intf_onu_id = (intf_id, onu_id)
gemport_id = yield self.resource_mgr.get_gemport_id(
@@ -490,7 +521,7 @@
flow_id = platform.mk_flow_id(intf_id, onu_id, LLDP_FLOW_INDEX)
downstream_flow = openolt_pb2.Flow(
- onu_id=onu_id, flow_id=flow_id, flow_type="downstream",
+ onu_id=onu_id, flow_id=flow_id, flow_type=DOWNSTREAM,
access_intf_id=3, network_intf_id=0, gemport_id=gemport_id,
alloc_id=alloc_id,
priority=logical_flow.priority,
@@ -505,31 +536,31 @@
classifier = openolt_pb2.Classifier()
- if 'eth_type' in classifier_info:
- classifier.eth_type = classifier_info['eth_type']
- if 'ip_proto' in classifier_info:
- classifier.ip_proto = classifier_info['ip_proto']
- if 'vlan_vid' in classifier_info:
- classifier.o_vid = classifier_info['vlan_vid']
- if 'metadata' in classifier_info:
- classifier.i_vid = classifier_info['metadata']
- if 'vlan_pcp' in classifier_info:
- classifier.o_pbits = classifier_info['vlan_pcp']
- if 'udp_src' in classifier_info:
- classifier.src_port = classifier_info['udp_src']
- if 'udp_dst' in classifier_info:
- classifier.dst_port = classifier_info['udp_dst']
- if 'ipv4_dst' in classifier_info:
- classifier.dst_ip = classifier_info['ipv4_dst']
- if 'ipv4_src' in classifier_info:
- classifier.src_ip = classifier_info['ipv4_src']
- if 'pkt_tag_type' in classifier_info:
- if classifier_info['pkt_tag_type'] == 'single_tag':
- classifier.pkt_tag_type = 'single_tag'
- elif classifier_info['pkt_tag_type'] == 'double_tag':
- classifier.pkt_tag_type = 'double_tag'
- elif classifier_info['pkt_tag_type'] == 'untagged':
- classifier.pkt_tag_type = 'untagged'
+ if ETH_TYPE in classifier_info:
+ classifier.eth_type = classifier_info[ETH_TYPE]
+ if IP_PROTO in classifier_info:
+ classifier.ip_proto = classifier_info[IP_PROTO]
+ if VLAN_VID in classifier_info:
+ classifier.o_vid = classifier_info[VLAN_VID]
+ if METADATA in classifier_info:
+ classifier.i_vid = classifier_info[METADATA]
+ if VLAN_PCP in classifier_info:
+ classifier.o_pbits = classifier_info[VLAN_PCP]
+ if UDP_SRC in classifier_info:
+ classifier.src_port = classifier_info[UDP_SRC]
+ if UDP_DST in classifier_info:
+ classifier.dst_port = classifier_info[UDP_DST]
+ if IPV4_DST in classifier_info:
+ classifier.dst_ip = classifier_info[IPV4_DST]
+ if IPV4_SRC in classifier_info:
+ classifier.src_ip = classifier_info[IPV4_SRC]
+ if PACKET_TAG_TYPE in classifier_info:
+ if classifier_info[PACKET_TAG_TYPE] == SINGLE_TAG:
+ classifier.pkt_tag_type = SINGLE_TAG
+ elif classifier_info[PACKET_TAG_TYPE] == DOUBLE_TAG:
+ classifier.pkt_tag_type = DOUBLE_TAG
+ elif classifier_info[PACKET_TAG_TYPE] == UNTAGGED:
+ classifier.pkt_tag_type = UNTAGGED
else:
classifier.pkt_tag_type = 'none'
@@ -538,13 +569,13 @@
def mk_action(self, action_info):
action = openolt_pb2.Action()
- if 'pop_vlan' in action_info:
- action.o_vid = action_info['vlan_vid']
+ if POP_VLAN in action_info:
+ action.o_vid = action_info[VLAN_VID]
action.cmd.remove_outer_tag = True
- elif 'push_vlan' in action_info:
- action.o_vid = action_info['vlan_vid']
+ elif PUSH_VLAN in action_info:
+ action.o_vid = action_info[VLAN_VID]
action.cmd.add_outer_tag = True
- elif 'trap_to_host' in action_info:
+ elif TRAP_TO_HOST in action_info:
action.cmd.trap_to_host = True
else:
self.log.info('Invalid-action-field', action_info=action_info)
@@ -598,8 +629,17 @@
def add_flow_to_device(self, flow, logical_flow):
self.log.debug('pushing flow to device', flow=flow)
- self.stub.FlowAdd(flow)
- self.register_flow(logical_flow, flow)
+ try:
+ self.stub.FlowAdd(flow)
+ except grpc.RpcError as grpc_e:
+ if grpc_e.code() == grpc.StatusCode.ALREADY_EXISTS:
+ self.log.warn('flow already exists', e=grpc_e, flow=flow)
+ else:
+ self.log.error('failed to add flow',
+ logical_flow=logical_flow, flow=flow,
+ grpc_error=grpc_e)
+ else:
+ self.register_flow(logical_flow, flow)
def register_flow(self, logical_flow, device_flow):
self.log.debug('registering flow in device',
@@ -653,10 +693,10 @@
device_id), FlowGroups(items=groups.values()))
def generate_stored_id(self, flow_id, direction):
- if direction == 'upstream':
+ if direction == UPSTREAM:
self.log.debug('upstream flow, shifting id')
return 0x1 << 15 | flow_id
- elif direction == 'downstream':
+ elif direction == DOWNSTREAM:
self.log.debug('downstream flow, not shifting id')
return flow_id
else:
@@ -665,6 +705,6 @@
def decode_stored_id(self, id):
if id >> 15 == 0x1:
- return (id & 0x7fff, 'upstream')
+ return (id & 0x7fff, UPSTREAM)
else:
- return (id, 'downstream')
+ return (id, DOWNSTREAM)
\ No newline at end of file