#!/usr/bin/env python # vim: tabstop=4 shiftwidth=4 softtabstop=4 # # Copyright 2012 Cisco Systems, Inc. # All Rights Reserved. # # 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. # # # Performs per host Linux Bridge configuration for Quantum. # Based on the structure of the OpenVSwitch agent in the # Quantum OpenVSwitch Plugin. # @author: Sumit Naiksatam, Cisco Systems, Inc. # from optparse import OptionParser from subprocess import * import ConfigParser import logging as LOG import MySQLdb import os import signal import sqlite3 import sys import time BRIDGE_NAME_PREFIX = "brq" GATEWAY_INTERFACE_PREFIX = "gw-" TAP_INTERFACE_PREFIX = "tap" BRIDGE_FS = "/sys/devices/virtual/net/" BRIDGE_NAME_PLACEHOLDER = "bridge_name" BRIDGE_INTERFACES_FS = BRIDGE_FS + BRIDGE_NAME_PLACEHOLDER + "/brif/" PORT_OPSTATUS_UPDATESQL = "UPDATE ports SET op_status = '%s' WHERE uuid = '%s'" DEVICE_NAME_PLACEHOLDER = "device_name" BRIDGE_PORT_FS_FOR_DEVICE = BRIDGE_FS + DEVICE_NAME_PLACEHOLDER + "/brport" VLAN_BINDINGS = "vlan_bindings" PORT_BINDINGS = "port_bindings" OP_STATUS_UP = "UP" OP_STATUS_DOWN = "DOWN" DB_CONNECTION = None class LinuxBridge: def __init__(self, br_name_prefix, physical_interface): self.br_name_prefix = br_name_prefix self.physical_interface = physical_interface def run_cmd(self, args): LOG.debug("Running command: " + " ".join(args)) p = Popen(args, stdout=PIPE) retval = p.communicate()[0] if p.returncode == -(signal.SIGALRM): LOG.debug("Timeout running command: " + " ".join(args)) if retval: LOG.debug("Command returned: %s" % retval) return retval def device_exists(self, device): """Check if ethernet device exists.""" retval = self.run_cmd(['ip', 'link', 'show', 'dev', device]) if retval: return True else: return False def get_bridge_name(self, network_id): if not network_id: LOG.warning("Invalid Network ID, will lead to incorrect bridge" \ "name") bridge_name = self.br_name_prefix + network_id[0:11] return bridge_name def get_subinterface_name(self, vlan_id): if not vlan_id: LOG.warning("Invalid VLAN ID, will lead to incorrect " \ "subinterface name") subinterface_name = '%s.%s' % (self.physical_interface, vlan_id) return subinterface_name def get_tap_device_name(self, interface_id): if not interface_id: LOG.warning("Invalid Interface ID, will lead to incorrect " \ "tap device name") tap_device_name = TAP_INTERFACE_PREFIX + interface_id[0:11] return tap_device_name def get_all_quantum_bridges(self): quantum_bridge_list = [] bridge_list = os.listdir(BRIDGE_FS) for bridge in bridge_list: if bridge.startswith(BRIDGE_NAME_PREFIX): quantum_bridge_list.append(bridge) return quantum_bridge_list def get_interfaces_on_bridge(self, bridge_name): if self.device_exists(bridge_name): bridge_interface_path = \ BRIDGE_INTERFACES_FS.replace(BRIDGE_NAME_PLACEHOLDER, bridge_name) return os.listdir(bridge_interface_path) def get_all_tap_devices(self): tap_devices = [] retval = self.run_cmd(['ip', 'tuntap']) rows = retval.split('\n') for row in rows: split_row = row.split(':') if split_row[0].startswith(TAP_INTERFACE_PREFIX): tap_devices.append(split_row[0]) return tap_devices def get_all_gateway_devices(self): gw_devices = [] retval = self.run_cmd(['ip', 'tuntap']) rows = retval.split('\n') for row in rows: split_row = row.split(':') if split_row[0].startswith(GATEWAY_INTERFACE_PREFIX): gw_devices.append(split_row[0]) return gw_devices def get_bridge_for_tap_device(self, tap_device_name): bridges = self.get_all_quantum_bridges() for bridge in bridges: interfaces = self.get_interfaces_on_bridge(bridge) if tap_device_name in interfaces: return bridge return None def is_device_on_bridge(self, device_name): if not device_name: return False else: bridge_port_path = \ BRIDGE_PORT_FS_FOR_DEVICE.replace(DEVICE_NAME_PLACEHOLDER, device_name) return os.path.exists(bridge_port_path) def ensure_vlan_bridge(self, network_id, vlan_id): """Create a vlan and bridge unless they already exist.""" interface = self.ensure_vlan(vlan_id) bridge_name = self.get_bridge_name(network_id) self.ensure_bridge(bridge_name, interface) return interface def ensure_vlan(self, vlan_id): """Create a vlan unless it already exists.""" interface = self.get_subinterface_name(vlan_id) if not self.device_exists(interface): LOG.debug("Creating subinterface %s for VLAN %s on interface %s" % (interface, vlan_id, self.physical_interface)) if self.run_cmd(['ip', 'link', 'add', 'link', self.physical_interface, 'name', interface, 'type', 'vlan', 'id', vlan_id]): return if self.run_cmd(['ip', 'link', 'set', interface, 'up']): return LOG.debug("Done creating subinterface %s" % interface) return interface def ensure_bridge(self, bridge_name, interface): """ Create a bridge unless it already exists. """ if not self.device_exists(bridge_name): LOG.debug("Starting bridge %s for subinterface %s" % (bridge_name, interface)) if self.run_cmd(['brctl', 'addbr', bridge_name]): return if self.run_cmd(['brctl', 'setfd', bridge_name, str(0)]): return if self.run_cmd(['brctl', 'stp', bridge_name, 'off']): return if self.run_cmd(['ip', 'link', 'set', bridge_name, 'up']): return LOG.debug("Done starting bridge %s for subinterface %s" % (bridge_name, interface)) self.run_cmd(['brctl', 'addif', bridge_name, interface]) def add_tap_interface(self, network_id, vlan_id, tap_device_name): """ If a VIF has been plugged into a network, this function will add the corresponding tap device to the relevant bridge """ if not tap_device_name: return False if not self.device_exists(tap_device_name): LOG.debug("Tap device: %s does not exist on this host, skipped" % tap_device_name) return False current_bridge_name = \ self.get_bridge_for_tap_device(tap_device_name) bridge_name = self.get_bridge_name(network_id) if bridge_name == current_bridge_name: return False LOG.debug("Adding device %s to bridge %s" % (tap_device_name, bridge_name)) if current_bridge_name: if self.run_cmd(['brctl', 'delif', current_bridge_name, tap_device_name]): return False self.ensure_vlan_bridge(network_id, vlan_id) if self.run_cmd(['brctl', 'addif', bridge_name, tap_device_name]): return False LOG.debug("Done adding device %s to bridge %s" % (tap_device_name, bridge_name)) return True def add_interface(self, network_id, vlan_id, interface_id): if not interface_id: """ Since the VIF id is null, no VIF is plugged into this port no more processing is required """ return False if interface_id.startswith(GATEWAY_INTERFACE_PREFIX): return self.add_tap_interface(network_id, vlan_id, interface_id) else: tap_device_name = self.get_tap_device_name(interface_id) return self.add_tap_interface(network_id, vlan_id, tap_device_name) def delete_vlan_bridge(self, bridge_name): if self.device_exists(bridge_name): interfaces_on_bridge = self.get_interfaces_on_bridge(bridge_name) for interface in interfaces_on_bridge: self.remove_interface(bridge_name, interface) if interface.startswith(self.physical_interface): self.delete_vlan(interface) LOG.debug("Deleting bridge %s" % bridge_name) if self.run_cmd(['ip', 'link', 'set', bridge_name, 'down']): return if self.run_cmd(['brctl', 'delbr', bridge_name]): return LOG.debug("Done deleting bridge %s" % bridge_name) else: LOG.error("Cannot delete bridge %s, does not exist" % bridge_name) def remove_interface(self, bridge_name, interface_name): if self.device_exists(bridge_name): if not self.is_device_on_bridge(interface_name): return True LOG.debug("Removing device %s from bridge %s" % \ (interface_name, bridge_name)) if self.run_cmd(['brctl', 'delif', bridge_name, interface_name]): return False LOG.debug("Done removing device %s from bridge %s" % \ (interface_name, bridge_name)) return True else: LOG.debug("Cannot remove device %s, bridge %s does not exist" % \ (interface_name, bridge_name)) return False def delete_vlan(self, interface): if self.device_exists(interface): LOG.debug("Deleting subinterface %s for vlan" % interface) if self.run_cmd(['ip', 'link', 'set', interface, 'down']): return if self.run_cmd(['ip', 'link', 'delete', interface]): return LOG.debug("Done deleting subinterface %s" % interface) class LinuxBridgeQuantumAgent: def __init__(self, br_name_prefix, physical_interface, polling_interval): self.polling_interval = int(polling_interval) self.setup_linux_bridge(br_name_prefix, physical_interface) def setup_linux_bridge(self, br_name_prefix, physical_interface): self.linux_br = LinuxBridge(br_name_prefix, physical_interface) def process_port_binding(self, port_id, network_id, interface_id, vlan_id): return self.linux_br.add_interface(network_id, vlan_id, interface_id) def process_unplugged_interfaces(self, plugged_interfaces): """ If there are any tap devices that are not corresponding to the list of attached VIFs, then those are corresponding to recently unplugged VIFs, so we need to remove those tap devices from their current bridge association """ plugged_tap_device_names = [] plugged_gateway_device_names = [] for interface in plugged_interfaces: if interface.startswith(GATEWAY_INTERFACE_PREFIX): """ The name for the gateway devices is set by the linux net driver, hence we use the name as is """ plugged_gateway_device_names.append(interface) else: tap_device_name = self.linux_br.get_tap_device_name(interface) plugged_tap_device_names.append(tap_device_name) LOG.debug("plugged tap device names %s" % plugged_tap_device_names) for tap_device in self.linux_br.get_all_tap_devices(): if tap_device not in plugged_tap_device_names: current_bridge_name = \ self.linux_br.get_bridge_for_tap_device(tap_device) if current_bridge_name: self.linux_br.remove_interface(current_bridge_name, tap_device) for gw_device in self.linux_br.get_all_gateway_devices(): if gw_device not in plugged_gateway_device_names: current_bridge_name = \ self.linux_br.get_bridge_for_tap_device(gw_device) if current_bridge_name: self.linux_br.remove_interface(current_bridge_name, gw_device) def process_deleted_networks(self, vlan_bindings): current_quantum_networks = vlan_bindings.keys() current_quantum_bridge_names = [] for network in current_quantum_networks: bridge_name = self.linux_br.get_bridge_name(network) current_quantum_bridge_names.append(bridge_name) quantum_bridges_on_this_host = self.linux_br.get_all_quantum_bridges() for bridge in quantum_bridges_on_this_host: if bridge not in current_quantum_bridge_names: self.linux_br.delete_vlan_bridge(bridge) def manage_networks_on_host(self, conn, old_vlan_bindings, old_port_bindings): if DB_CONNECTION != 'sqlite': cursor = MySQLdb.cursors.DictCursor(conn) else: cursor = conn.cursor() cursor.execute("SELECT * FROM vlan_bindings") rows = cursor.fetchall() cursor.close() vlan_bindings = {} vlans_string = "" for row in rows: vlan_bindings[row['network_id']] = row vlans_string = "%s %s" % (vlans_string, row) plugged_interfaces = [] cursor = MySQLdb.cursors.DictCursor(conn) cursor.execute("SELECT * FROM ports where state = 'ACTIVE'") port_bindings = cursor.fetchall() cursor.close() ports_string = "" for pb in port_bindings: ports_string = "%s %s" % (ports_string, pb) if pb['interface_id']: vlan_id = \ str(vlan_bindings[pb['network_id']]['vlan_id']) if self.process_port_binding(pb['uuid'], pb['network_id'], pb['interface_id'], vlan_id): cursor = MySQLdb.cursors.DictCursor(conn) sql = PORT_OPSTATUS_UPDATESQL % (pb['uuid'], OP_STATUS_UP) cursor.execute(sql) cursor.close() plugged_interfaces.append(pb['interface_id']) if old_port_bindings != port_bindings: LOG.debug("Port-bindings: %s" % ports_string) self.process_unplugged_interfaces(plugged_interfaces) if old_vlan_bindings != vlan_bindings: LOG.debug("VLAN-bindings: %s" % vlans_string) self.process_deleted_networks(vlan_bindings) conn.commit() return {VLAN_BINDINGS: vlan_bindings, PORT_BINDINGS: port_bindings} def daemon_loop(self, conn): old_vlan_bindings = {} old_port_bindings = {} while True: bindings = self.manage_networks_on_host(conn, old_vlan_bindings, old_port_bindings) old_vlan_bindings = bindings[VLAN_BINDINGS] old_port_bindings = bindings[PORT_BINDINGS] time.sleep(self.polling_interval) def main(): usagestr = "%prog [OPTIONS] " parser = OptionParser(usage=usagestr) parser.add_option("-v", "--verbose", dest="verbose", action="store_true", default=False, help="turn on verbose logging") options, args = parser.parse_args() if options.verbose: LOG.basicConfig(level=LOG.DEBUG) else: LOG.basicConfig(level=LOG.WARN) if len(args) != 1: parser.print_help() sys.exit(1) config_file = args[0] config = ConfigParser.ConfigParser() conn = None try: fh = open(config_file) fh.close() config.read(config_file) br_name_prefix = BRIDGE_NAME_PREFIX physical_interface = config.get("LINUX_BRIDGE", "physical_interface") polling_interval = config.get("AGENT", "polling_interval") 'Establish database connection and load models' global DB_CONNECTION DB_CONNECTION = config.get("DATABASE", "connection") if DB_CONNECTION == 'sqlite': LOG.info("Connecting to sqlite DB") conn = sqlite3.connect(":memory:") conn.row_factory = sqlite3.Row else: db_name = config.get("DATABASE", "name") db_user = config.get("DATABASE", "user") db_pass = config.get("DATABASE", "pass") db_host = config.get("DATABASE", "host") db_port = int(config.get("DATABASE", "port")) LOG.info("Connecting to database %s on %s" % (db_name, db_host)) conn = MySQLdb.connect(host=db_host, user=db_user, port=db_port, passwd=db_pass, db=db_name) except Exception, e: LOG.error("Unable to parse config file \"%s\": \nException%s" % (config_file, str(e))) sys.exit(1) try: plugin = LinuxBridgeQuantumAgent(br_name_prefix, physical_interface, polling_interval) LOG.info("Agent initialized successfully, now running...") plugin.daemon_loop(conn) finally: if conn: conn.close() sys.exit(0) if __name__ == "__main__": main()