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Diffstat (limited to 'src/ovs/ofctl.py')
| -rw-r--r-- | src/ovs/ofctl.py | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/src/ovs/ofctl.py b/src/ovs/ofctl.py new file mode 100644 index 00000000..c6aaddc9 --- /dev/null +++ b/src/ovs/ofctl.py @@ -0,0 +1,316 @@ +# Copyright 2015 Intel Corporation. +# +# Licensed 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. + +"""Wrapper for an OVS bridge for convenient use of ``ovs-vsctl`` and +``ovs-ofctl`` on it. + +Much of this code is based on ``ovs-lib.py`` from Open Stack: + +https://github.com/openstack/neutron/blob/6eac1dc99124ca024d6a69b3abfa3bc69c735667/neutron/agent/linux/ovs_lib.py +""" + +import os +import logging +import string + +from tools import tasks +from conf import settings + +_OVS_VSCTL_BIN = os.path.join(settings.getValue('OVS_DIR'), 'utilities', + 'ovs-vsctl') +_OVS_OFCTL_BIN = os.path.join(settings.getValue('OVS_DIR'), 'utilities', + 'ovs-ofctl') + +class OFBase(object): + """Add/remove/show datapaths using ``ovs-ofctl``. + """ + def __init__(self, timeout=10): + """Initialise logger. + + :param timeout: Timeout to be used for each command + + :returns: None + """ + self.logger = logging.getLogger(__name__) + self.timeout = timeout + + # helpers + + def run_vsctl(self, args, check_error=False): + """Run ``ovs-vsctl`` with supplied arguments. + + :param args: Arguments to pass to ``ovs-vsctl`` + :param check_error: Throw exception on error + + :return: None + """ + cmd = ['sudo', _OVS_VSCTL_BIN, '--timeout', str(self.timeout)] + args + return tasks.run_task( + cmd, self.logger, 'Running ovs-vsctl...', check_error) + + # datapath management + + def add_br(self, br_name='br0'): + """Add datapath. + + :param br_name: Name of bridge + + :return: Instance of :class OFBridge: + """ + self.logger.debug('add bridge') + self.run_vsctl(['add-br', br_name]) + + return OFBridge(br_name, self.timeout) + + def del_br(self, br_name='br0'): + """Delete datapath. + + :param br_name: Name of bridge + + :return: None + """ + self.logger.debug('delete bridge') + self.run_vsctl(['del-br', br_name]) + + +class OFBridge(OFBase): + """Control a bridge instance using ``ovs-vsctl`` and ``ovs-ofctl``. + """ + def __init__(self, br_name='br0', timeout=10): + """Initialise bridge. + + :param br_name: Bridge name + :param timeout: Timeout to be used for each command + + :returns: None + """ + super(OFBridge, self).__init__(timeout) + self.br_name = br_name + self._ports = {} + + # context manager + + def __enter__(self): + """Create datapath + + :returns: self + """ + return self + + def __exit__(self, type_, value, traceback): + """Remove datapath. + """ + if not traceback: + self.destroy() + + # helpers + + def run_ofctl(self, args, check_error=False): + """Run ``ovs-ofctl`` with supplied arguments. + + :param args: Arguments to pass to ``ovs-ofctl`` + :param check_error: Throw exception on error + + :return: None + """ + cmd = ['sudo', _OVS_OFCTL_BIN, '--timeout', str(self.timeout)] + args + return tasks.run_task( + cmd, self.logger, 'Running ovs-ofctl...', check_error) + + def create(self): + """Create bridge. + """ + self.logger.debug('create bridge') + self.add_br(self.br_name) + + def destroy(self): + """Destroy bridge. + """ + self.logger.debug('destroy bridge') + self.del_br(self.br_name) + + def reset(self): + """Reset bridge. + """ + self.logger.debug('reset bridge') + self.destroy() + self.create() + + # port management + + def add_port(self, port_name, params): + """Add port to bridge. + + :param port_name: Name of port + :param params: Additional list of parameters to add-port + + :return: OpenFlow port number for the port + """ + self.logger.debug('add port') + self.run_vsctl(['add-port', self.br_name, port_name]+params) + + # This is how port number allocation works currently + # This possibly will not work correctly if there are port deletions + # in between + of_port = len(self._ports) + 1 + self._ports[port_name] = (of_port, params) + return of_port + + def del_port(self, port_name): + """Remove port from bridge. + + :param port_name: Name of port + + :return: None + """ + self.logger.debug('delete port') + self.run_vsctl(['del-port', self.br_name, port_name]) + self._ports.pop(port_name) + + def set_db_attribute(self, table_name, record, column, value): + """Set database attribute. + + :param table_name: Name of table + :param record: Name of record + :param column: Name of column + :param value: Value to set + + :return: None + """ + self.logger.debug('set attribute') + self.run_vsctl(['set', table_name, record, '%s=%s' % (column, value)]) + + def get_ports(self): + """Get the ports of this bridge + + Structure of the returned ports dictionary is + 'portname': (openflow_port_number, extra_parameters) + + Example: + ports = { + 'dpdkport0': + (1, ['--', 'set', 'Interface', 'dpdkport0', 'type=dpdk']), + 'dpdkvhostport0': + (2, ['--', 'set', 'Interface', 'dpdkvhostport0', + 'type=dpdkvhost']) + } + + :return: Dictionary of ports + """ + return self._ports + + def clear_db_attribute(self, table_name, record, column): + """Clear database attribute. + + :param table_name: Name of table + :param record: Name of record + :param column: Name of column + + :return: None + """ + self.logger.debug('clear attribute') + self.run_vsctl(['clear', table_name, record, column]) + + # flow mangement + + def add_flow(self, flow): + """Add flow to bridge. + + :param flow: Flow description as a dictionary + For flow dictionary structure, see function flow_key + + :return: None + """ + if not flow.get('actions'): + self.logger.error('add flow requires actions') + return + + self.logger.debug('add flow') + _flow_key = flow_key(flow) + self.logger.debug('key : %s', _flow_key) + self.run_ofctl(['add-flow', self.br_name, _flow_key]) + + def del_flow(self, flow): + """Delete flow from bridge. + + :param flow: Flow description as a dictionary + For flow dictionary structure, see function flow_key + flow=None will delete all flows + + :return: None + """ + self.logger.debug('delete flow') + _flow_key = flow_key(flow) + self.logger.debug('key : %s', _flow_key) + self.run_ofctl(['del-flows', self.br_name, _flow_key]) + + def del_flows(self): + """Delete all flows from bridge. + """ + self.logger.debug('delete flows') + self.run_ofctl(['del-flows', self.br_name]) + + def dump_flows(self): + """Dump all flows from bridge. + """ + self.logger.debug('dump flows') + self.run_ofctl(['dump-flows', self.br_name]) + +# +# helper functions +# + +def flow_key(flow): + """Model a flow key string for ``ovs-ofctl``. + + Syntax taken from ``ovs-ofctl`` manpages: + http://openvswitch.org/cgi-bin/ovsman.cgi?page=utilities%2Fovs-ofctl.8 + + Example flow dictionary: + flow = { + 'in_port': '1', + 'idle_timeout': '0', + 'actions': ['output:3'] + } + + :param flow: Flow description as a dictionary + + :return: String + :rtype: str + """ + _flow_add_key = string.Template('${fields},action=${actions}') + _flow_del_key = string.Template('${fields}') + + field_params = [] + + user_params = (x for x in list(flow.items()) if x[0] != 'actions') + for (key, default) in user_params: + field_params.append('%(field)s=%(value)s' % + {'field': key, 'value': default}) + + field_params = ','.join(field_params) + + _flow_key_param = { + 'fields': field_params, + } + + # no actions == delete key + if 'actions' in flow: + _flow_key_param['actions'] = ','.join(flow['actions']) + + flow_str = _flow_add_key.substitute(_flow_key_param) + else: + flow_str = _flow_del_key.substitute(_flow_key_param) + + return flow_str |