#
#
-# Copyright (C) 2011 Google Inc.
+# Copyright (C) 2011, 2012 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# 02110-1301, USA.
-"""Ip address pool management functions.
+"""IP address pool management functions.
"""
from ganeti import errors
+def _ComputeIpv4NumHosts(network_size):
+ """Derives the number of hosts in an IPv4 network from the size.
+
+ """
+ return 2 ** (32 - network_size)
+
+
+IPV4_NETWORK_MIN_SIZE = 30
+# FIXME: This limit is for performance reasons. Remove when refactoring
+# for performance tuning was successful.
+IPV4_NETWORK_MAX_SIZE = 16
+IPV4_NETWORK_MIN_NUM_HOSTS = _ComputeIpv4NumHosts(IPV4_NETWORK_MIN_SIZE)
+IPV4_NETWORK_MAX_NUM_HOSTS = _ComputeIpv4NumHosts(IPV4_NETWORK_MAX_SIZE)
+
+
class AddressPool(object):
- """Address pool class, wrapping an objects.Network object
+ """Address pool class, wrapping an C{objects.Network} object.
This class provides methods to manipulate address pools, backed by
L{objects.Network} objects.
"""
+ FREE = bitarray("0")
+ RESERVED = bitarray("1")
+
def __init__(self, network):
- """Initialize a new IPv4 address pool from an objects.Network object
+ """Initialize a new IPv4 address pool from an L{objects.Network} object.
@type network: L{objects.Network}
@param network: the network object from which the pool will be generated
self.net = network
self.network = ipaddr.IPNetwork(self.net.network)
+ if self.network.numhosts > IPV4_NETWORK_MAX_NUM_HOSTS:
+ raise errors.AddressPoolError("A big network with %s host(s) is currently"
+ " not supported. please specify at most a"
+ " /%s network" %
+ (str(self.network.numhosts),
+ IPV4_NETWORK_MAX_SIZE))
+
+ if self.network.numhosts < IPV4_NETWORK_MIN_NUM_HOSTS:
+ raise errors.AddressPoolError("A network with only %s host(s) is too"
+ " small, please specify at least a /%s"
+ " network" %
+ (str(self.network.numhosts),
+ IPV4_NETWORK_MIN_SIZE))
if self.net.gateway:
self.gateway = ipaddr.IPAddress(self.net.gateway)
return int(addr) - int(self.network.network)
def Update(self):
- """Write address pools back to the network object"""
+ """Write address pools back to the network object.
+
+ """
# pylint: disable=E1103
self.net.ext_reservations = self.ext_reservations.to01()
self.net.reservations = self.reservations.to01()
@property
def all_reservations(self):
- """Return a combined map of internal + external reservations."""
+ """Return a combined map of internal and external reservations.
+
+ """
return (self.reservations | self.ext_reservations)
def Validate(self):
- assert self.net.family == 4
assert len(self.reservations) == self._GetSize()
assert len(self.ext_reservations) == self._GetSize()
- all_res = self.reservations & self.ext_reservations
- assert not all_res.any()
if self.gateway is not None:
- assert self.net.family == self.gateway.version
assert self.gateway in self.network
if self.network6 and self.gateway6:
- assert self.gateway6 in self.network6
+ assert self.gateway6 in self.network6 or self.gateway6.is_link_local
return True
def IsFull(self):
- """Check whether the network is full"""
+ """Check whether the network is full.
+
+ """
return self.all_reservations.all()
def GetReservedCount(self):
- """Get the count of reserved addresses"""
+ """Get the count of reserved addresses.
+
+ """
return self.all_reservations.count(True)
def GetFreeCount(self):
- """Get the count of unused addresses"""
+ """Get the count of unused addresses.
+
+ """
return self.all_reservations.count(False)
def GetMap(self):
- """Return a textual representation of the network's occupation status."""
+ """Return a textual representation of the network's occupation status.
+
+ """
return self.all_reservations.to01().replace("1", "X").replace("0", ".")
- def IsReserved(self, address):
- """Checks if the given IP is reserved"""
+ def IsReserved(self, address, external=False):
+ """Checks if the given IP is reserved.
+
+ """
idx = self._GetAddrIndex(address)
- return self.all_reservations[idx]
+ if external:
+ return self.ext_reservations[idx]
+ else:
+ return self.reservations[idx]
def Reserve(self, address, external=False):
- """Mark an address as used."""
- if self.IsReserved(address):
- raise errors.AddressPoolError("%s is already reserved" % address)
+ """Mark an address as used.
+
+ """
+ if self.IsReserved(address, external):
+ if external:
+ msg = "IP %s is already externally reserved" % address
+ else:
+ msg = "IP %s is already used by an instance" % address
+ raise errors.AddressPoolError(msg)
+
self._Mark(address, external=external)
def Release(self, address, external=False):
- """Release a given address reservation."""
+ """Release a given address reservation.
+
+ """
+ if not self.IsReserved(address, external):
+ if external:
+ msg = "IP %s is not externally reserved" % address
+ else:
+ msg = "IP %s is not used by an instance" % address
+ raise errors.AddressPoolError(msg)
+
self._Mark(address, value=False, external=external)
def GetFreeAddress(self):
- """Returns the first available address."""
+ """Returns the first available address.
+
+ """
if self.IsFull():
raise errors.AddressPoolError("%s is full" % self.network)
return address
def GenerateFree(self):
- """A generator for free addresses."""
- def _iter_free():
- for idx in self.all_reservations.search("0", 64):
- yield str(self.network[idx])
- # pylint: disable=E1101
- return _iter_free().next
+ """Returns the first free address of the network.
+
+ @raise errors.AddressPoolError: Pool is full
+
+ """
+ idx = self.all_reservations.search(self.FREE, 1)
+ if idx:
+ return str(self.network[idx[0]])
+ else:
+ raise errors.AddressPoolError("%s is full" % self.network)
def GetExternalReservations(self):
- """Returns a list of all externally reserved addresses"""
- idxs = self.ext_reservations.search("1")
+ """Returns a list of all externally reserved addresses.
+
+ """
+ # pylint: disable=E1103
+ idxs = self.ext_reservations.search(self.RESERVED)
return [str(self.network[idx]) for idx in idxs]
@classmethod
def InitializeNetwork(cls, net):
- """Initialize an L{objects.Network} object
+ """Initialize an L{objects.Network} object.
- Reserve the network, broadcast and gateway IPs
+ Reserve the network, broadcast and gateway IP addresses.
"""
obj = cls(net)
projects / ganeti-local / blobdiff