netif.py

来自「xen虚拟机源代码安装包」· Python 代码 · 共 229 行

#============================================================================
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#============================================================================
# Copyright (C) 2004, 2005 Mike Wray <[e-mail]>
# Copyright (C) 2005 XenSource Ltd
#============================================================================


"""Support for virtual network interfaces.
"""

import os
import random
import re

from xen.xend import XendOptions
from xen.xend.server.DevController import DevController
from xen.xend.XendError import VmError
from xen.xend.XendXSPolicyAdmin import XSPolicyAdminInstance
import xen.util.xsm.xsm as security
from xen.util import xsconstants

from xen.xend.XendLogging import log

xoptions = XendOptions.instance()

def randomMAC():
    """Generate a random MAC address.

    Uses OUI (Organizationally Unique Identifier) 00-16-3E, allocated to
    Xensource, Inc. The OUI list is available at
    http://standards.ieee.org/regauth/oui/oui.txt.

    The remaining 3 fields are random, with the first bit of the first
    random field set 0.

    @return: MAC address string
    """
    mac = [ 0x00, 0x16, 0x3e,
            random.randint(0x00, 0x7f),
            random.randint(0x00, 0xff),
            random.randint(0x00, 0xff) ]
    return ':'.join(map(lambda x: "%02x" % x, mac))

rate_re = re.compile("^([0-9]+)([GMK]?)([Bb])/s(@([0-9]+)([mu]?)s)?$")

def parseRate(ratestr):
    """if parsing fails this will return default of unlimited rate"""
    bytes_per_interval = 0xffffffffL # 0xffffffff # big default
    interval_usecs     = 0L          # disabled

    m = rate_re.match(ratestr)
    if m:
        bytes_per_sec = long(m.group(1))

        if m.group(2) == 'G':
            bytes_per_sec *= 1000 * 1000 * 1000
        elif m.group(2) == 'M':
            bytes_per_sec *= 1000 * 1000
        elif m.group(2) == 'K':
            bytes_per_sec *= 1000

        if m.group(3) == 'b':
            bytes_per_sec /= 8

        if m.group(5) is None:
            interval_usecs = 50000L      # 50ms default
        else:
            interval_usecs = long(m.group(5))
            if m.group(6) == '':
                interval_usecs *= 1000 * 1000
            elif m.group(6) == 'm':
                interval_usecs *= 1000

        bytes_per_interval = (bytes_per_sec * interval_usecs) / 1000000L

        # overflow / underflow checking: default to unlimited rate
        if bytes_per_interval == 0 or bytes_per_interval > 0xffffffffL or \
           interval_usecs == 0 or interval_usecs > 0xffffffffL:
            bytes_per_interval = 0xffffffffL
            interval_usecs     = 0L

    return "%lu,%lu" % (bytes_per_interval, interval_usecs)


class NetifController(DevController):
    """Network interface controller. Handles all network devices for a domain.
    """
    
    def __init__(self, vm):
        DevController.__init__(self, vm)

    def getDeviceDetails(self, config):
        """@see DevController.getDeviceDetails"""

        script  = config.get('script', xoptions.get_vif_script())
        typ     = config.get('type')
        bridge  = config.get('bridge')
        mac     = config.get('mac')
        vifname = config.get('vifname')
        rate    = config.get('rate')
        uuid    = config.get('uuid')
        ipaddr  = config.get('ip')
        model   = config.get('model')
        accel   = config.get('accel')
        sec_lab = config.get('security_label')

        if not mac:
            raise VmError("MAC address not specified or generated.")

        devid = self.allocateDeviceID()

        back = { 'script' : script,
                 'mac'    : mac }
        if typ:
            back['type'] = typ
        if ipaddr:
            back['ip'] = ipaddr
        if bridge:
            back['bridge'] = bridge
        if vifname:
            back['vifname'] = vifname
        if rate:
            back['rate'] = rate
        if uuid:
            back['uuid'] = uuid
        if model:
            back['model'] = model
        if accel:
            back['accel'] = accel
        if sec_lab:
            back['security_label'] = sec_lab

        config_path = "device/%s/%d/" % (self.deviceClass, devid)
        for x in back:
            self.vm._writeVm(config_path + x, back[x])

        back['handle'] = "%i" % devid
        back['script'] = os.path.join(xoptions.network_script_dir, script)
        if rate:
            back['rate'] = parseRate(rate)

        front = {}
        if typ != 'ioemu':
            front = { 'handle' : "%i" % devid,
                      'mac'    : mac }

        if security.on() == xsconstants.XS_POLICY_ACM:
            self.do_access_control(config)

        return (devid, back, front)


    def do_access_control(self, config):
        """ do access control checking. Throws a VMError if access is denied """
        domain_label = self.vm.get_security_label()
        stes = XSPolicyAdminInstance().get_stes_of_vmlabel(domain_label)
        res_label = config.get('security_label')
        if len(stes) > 1 or res_label:
            if not res_label:
                raise VmError("'VIF' must be labeled")
            (label, ssidref, policy) = \
                              security.security_label_to_details(res_label)
            if domain_label:
                rc = security.res_security_check_xapi(label, ssidref,
                                                      policy,
                                                      domain_label)
                if rc == 0:
                    raise VmError("VM's access to network device denied. "
                                  "Check labeling")
            else:
                raise VmError("VM must have a security label to access "
                              "network device")


    def getDeviceConfiguration(self, devid, transaction = None):
        """@see DevController.configuration"""

        result = DevController.getDeviceConfiguration(self, devid, transaction)

        config_path = "device/%s/%d/" % (self.deviceClass, devid)
        devinfo = ()
        for x in ( 'script', 'ip', 'bridge', 'mac',
                   'type', 'vifname', 'rate', 'uuid', 'model', 'accel',
                   'security_label'):
            if transaction is None:
                y = self.vm._readVm(config_path + x)
            else:
                y = self.vm._readVmTxn(transaction, config_path + x)
            devinfo += (y,)
        (script, ip, bridge, mac, typ, vifname, rate, uuid,
         model, accel, security_label) = devinfo

        if script:
            result['script'] = script
        if ip:
            result['ip'] = ip
        if bridge:
            result['bridge'] = bridge
        if mac:
            result['mac'] = mac
        if typ:
            result['type'] = typ
        if vifname:
            result['vifname'] = vifname
        if rate:
            result['rate'] = rate
        if uuid:
            result['uuid'] = uuid
        if model:
            result['model'] = model
        if accel:
            result['accel'] = accel
        if security_label:
            result['security_label'] = security_label

        return result