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# By Peter V. Saveliev https://pypi.python.org/pypi/pyroute2. Dual licensed under the Apache 2 and GPLv2+ see https://github.com/svinota/pyroute2 for License details.
import logging
import threading
from socket import AF_UNSPEC
from pyroute2.common import basestring
from pyroute2.netlink import nlmsg
from pyroute2.netlink.rtnl.rtmsg import rtmsg
from pyroute2.netlink.rtnl.req import IPRouteRequest
from pyroute2.ipdb.transactional import Transactional
class Metrics(Transactional):
def __init__(self, *argv, **kwarg):
Transactional.__init__(self, *argv, **kwarg)
self._fields = [rtmsg.metrics.nla2name(i[0]) for i
in rtmsg.metrics.nla_map]
class RouteKey(dict):
'''
Construct from a netlink message a key that can be used
to locate the route in the table
'''
def __init__(self, msg):
# calculate dst
if msg.get_attr('RTA_DST', None) is not None:
dst = '%s/%s' % (msg.get_attr('RTA_DST'),
msg['dst_len'])
else:
dst = 'default'
self['dst'] = dst
# use output | input interfaces as key also
for key in ('oif', 'iif'):
value = msg.get_attr(msg.name2nla(key))
if value:
self[key] = value
class Route(Transactional):
'''
Persistent transactional route object
'''
def __init__(self, ipdb, mode=None, parent=None, uid=None):
Transactional.__init__(self, ipdb, mode, parent, uid)
self._exists = False
self._load_event = threading.Event()
self._fields = [rtmsg.nla2name(i[0]) for i in rtmsg.nla_map]
self._fields.append('flags')
self._fields.append('src_len')
self._fields.append('dst_len')
self._fields.append('table')
self._fields.append('removal')
self.cleanup = ('attrs',
'header',
'event')
with self._direct_state:
self['metrics'] = Metrics(parent=self)
def load_netlink(self, msg):
with self._direct_state:
self._exists = True
self.update(msg)
# re-init metrics
metrics = self.get('metrics', Metrics(parent=self))
with metrics._direct_state:
for metric in tuple(metrics.keys()):
del metrics[metric]
self['metrics'] = metrics
# merge key
for (name, value) in msg['attrs']:
norm = rtmsg.nla2name(name)
# normalize RTAX
if norm == 'metrics':
with self['metrics']._direct_state:
for (rtax, rtax_value) in value['attrs']:
rtax_norm = rtmsg.metrics.nla2name(rtax)
self['metrics'][rtax_norm] = rtax_value
else:
self[norm] = value
if msg.get_attr('RTA_DST', None) is not None:
dst = '%s/%s' % (msg.get_attr('RTA_DST'),
msg['dst_len'])
else:
dst = 'default'
self['dst'] = dst
# finally, cleanup all not needed
for item in self.cleanup:
if item in self:
del self[item]
self.sync()
def sync(self):
self._load_event.set()
def reload(self):
# do NOT call get_routes() here, it can cause race condition
self._load_event.wait()
return self
def commit(self, tid=None, transaction=None, rollback=False):
self._load_event.clear()
error = None
if tid:
transaction = self._transactions[tid]
else:
transaction = transaction or self.last()
# create a new route
if not self._exists:
try:
self.nl.route('add', **IPRouteRequest(self))
except Exception:
self.nl = None
self.ipdb.routes.remove(self)
raise
# work on existing route
snapshot = self.pick()
try:
# route set
request = IPRouteRequest(transaction - snapshot)
if any([request[x] not in (None, {'attrs': []}) for x in request]):
self.nl.route('set', **IPRouteRequest(transaction))
if transaction.get('removal'):
self.nl.route('delete', **IPRouteRequest(snapshot))
except Exception as e:
if not rollback:
ret = self.commit(transaction=snapshot, rollback=True)
if isinstance(ret, Exception):
error = ret
else:
error = e
else:
self.drop()
x = RuntimeError()
x.cause = e
raise x
if not rollback:
self.drop()
if error is not None:
error.transaction = transaction
raise error
if not rollback:
self.reload()
return self
def remove(self):
self['removal'] = True
return self
class RoutingTable(object):
def __init__(self, ipdb, prime=None):
self.ipdb = ipdb
self.records = prime or []
def __repr__(self):
return repr(self.records)
def __len__(self):
return len(self.records)
def __iter__(self):
for record in tuple(self.records):
yield record
def keys(self, key='dst'):
return [x[key] for x in self.records]
def describe(self, target, forward=True):
if isinstance(target, int):
return {'route': self.records[target],
'index': target}
if isinstance(target, basestring):
target = {'dst': target}
if not isinstance(target, dict):
raise TypeError('unsupported key type')
for record in self.records:
for key in target:
# skip non-existing keys
#
# it's a hack, but newly-created routes
# don't contain all the fields that are
# in the netlink message
if record.get(key) is None:
continue
# if any key doesn't match
if target[key] != record[key]:
break
else:
# if all keys match
return {'route': record,
'index': self.records.index(record)}
if not forward:
raise KeyError('route not found')
# split masks
if target.get('dst', '').find('/') >= 0:
dst = target['dst'].split('/')
target['dst'] = dst[0]
target['dst_len'] = int(dst[1])
if target.get('src', '').find('/') >= 0:
src = target['src'].split('/')
target['src'] = src[0]
target['src_len'] = int(src[1])
# load and return the route, if exists
route = Route(self.ipdb)
route.load_netlink(self.ipdb.nl.get_routes(**target)[0])
return {'route': route,
'index': None}
def __delitem__(self, key):
self.records.pop(self.describe(key, forward=False)['index'])
def __setitem__(self, key, value):
try:
record = self.describe(key, forward=False)
except KeyError:
record = {'route': Route(self.ipdb),
'index': None}
if isinstance(value, nlmsg):
record['route'].load_netlink(value)
elif isinstance(value, Route):
record['route'] = value
elif isinstance(value, dict):
with record['route']._direct_state:
record['route'].update(value)
if record['index'] is None:
self.records.append(record['route'])
else:
self.records[record['index']] = record['route']
def __getitem__(self, key):
return self.describe(key, forward=True)['route']
def __contains__(self, key):
try:
self.describe(key, forward=False)
return True
except KeyError:
return False
class RoutingTableSet(object):
def __init__(self, ipdb):
self.ipdb = ipdb
self.tables = {254: RoutingTable(self.ipdb)}
def add(self, spec=None, **kwarg):
'''
Create a route from a dictionary
'''
spec = spec or kwarg
table = spec.get('table', 254)
assert 'dst' in spec
if table not in self.tables:
self.tables[table] = RoutingTable(self.ipdb)
route = Route(self.ipdb)
metrics = spec.pop('metrics', {})
route.update(spec)
route.metrics.update(metrics)
self.tables[table][route['dst']] = route
route.begin()
return route
def load_netlink(self, msg):
'''
Loads an existing route from a rtmsg
'''
table = msg.get('table', 254)
# construct a key
# FIXME: temporary solution
# FIXME: can `Route()` be used as a key?
key = RouteKey(msg)
# RTM_DELROUTE
if msg['event'] == 'RTM_DELROUTE':
try:
# locate the record
record = self.tables[table][key]
# delete the record
del self.tables[table][key]
# sync ???
record.sync()
except Exception as e:
logging.debug(e)
logging.debug(msg)
return
# RTM_NEWROUTE
if table not in self.tables:
self.tables[table] = RoutingTable(self.ipdb)
self.tables[table][key] = msg
return self.tables[table][key]
def remove(self, route, table=None):
if isinstance(route, Route):
table = route.get('table', 254)
route = route.get('dst', 'default')
else:
table = table or 254
del self.tables[table][route]
def describe(self, spec, table=254):
return self.tables[table].describe(spec)
def get(self, dst, table=None):
table = table or 254
return self.tables[table][dst]
def keys(self, table=254, family=AF_UNSPEC):
return [x['dst'] for x in self.tables[table]
if (x['family'] == family)
or (family == AF_UNSPEC)]
def has_key(self, key, table=254):
return key in self.tables[table]
def __contains__(self, key):
return key in self.tables[254]
def __getitem__(self, key):
return self.get(key)
def __setitem__(self, key, value):
assert key == value['dst']
return self.add(value)
def __delitem__(self, key):
return self.remove(key)
def __repr__(self):
return repr(self.tables[254])
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