src/emuvim/api/openstack/ip_handler.py

   1 """
   2 Copyright (c) 2017 SONATA-NFV and Paderborn University
   3 ALL RIGHTS RESERVED.
   4
   5 Licensed under the Apache License, Version 2.0 (the "License");
   6 you may not use this file except in compliance with the License.
   7 You may obtain a copy of the License at
   8
   9     http://www.apache.org/licenses/LICENSE-2.0
  10
  11 Unless required by applicable law or agreed to in writing, software
  12 distributed under the License is distributed on an "AS IS" BASIS,
  13 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 See the License for the specific language governing permissions and
  15 limitations under the License.
  16
  17 Neither the name of the SONATA-NFV, Paderborn University
  18 nor the names of its contributors may be used to endorse or promote
  19 products derived from this software without specific prior written
  20 permission.
  21
  22 This work has been performed in the framework of the SONATA project,
  23 funded by the European Commission under Grant number 671517 through
  24 the Horizon 2020 and 5G-PPP programmes. The authors would like to
  25 acknowledge the contributions of their colleagues of the SONATA
  26 partner consortium (www.sonata-nfv.eu).
  27 """
  28 from resources.net import Net
  29 import threading
  30
  31 lock = threading.Lock()
  32
  33 __issued_ips = dict()
  34 __default_subnet_size = 256
  35 __default_subnet_bitmask = 24
  36 __first_ip = Net.ip_2_int('10.0.0.0')
  37 __last_ip = Net.ip_2_int('10.255.255.255')
  38 __current_ip = __first_ip
  39
  40
  41 def get_new_cidr(uuid):
  42     """
  43     Calculates a unused cidr for a subnet.
  44
  45     :param uuid: The UUID of the subnet - Thus it can store which subnet gets which CIDR
  46     :type uuid: ``str``
  47     :return: Returns None if all available CIDR are used. Otherwise returns a valid CIDR.
  48     :rtype: ``str``
  49     """
  50     global lock
  51     lock.acquire()
  52
  53     global __current_ip
  54     while __first_ip <= __current_ip < __last_ip and __current_ip in __issued_ips:
  55         __current_ip += __default_subnet_size
  56
  57     if __current_ip >= __last_ip or __current_ip < __first_ip or __current_ip in __issued_ips:
  58         return None
  59
  60     __issued_ips[__current_ip] = uuid
  61     lock.release()
  62
  63     return Net.int_2_ip(__current_ip) + '/' + str(__default_subnet_bitmask)
  64
  65
  66 def free_cidr(cidr, uuid):
  67     """
  68     Frees a issued CIDR thus it can be reused.
  69
  70     :param cidr: The currently used CIDR.
  71     :type cidr: ``str``
  72     :param uuid: The UUID of the Subnet, which uses this CIDR.
  73     :type uuid: ``str``
  74     :return: Returns False if the CIDR is None or the UUID did not correspond tho the used CIDR. Else it returns True.
  75     :rtype: ``bool``
  76     """
  77     if cidr is None:
  78         return False
  79
  80     global __current_ip
  81     int_ip = Net.cidr_2_int(cidr)
  82
  83     global lock
  84     lock.acquire()
  85
  86     if int_ip in __issued_ips and __issued_ips[int_ip] == uuid:
  87         del __issued_ips[int_ip]
  88         if int_ip < __current_ip:
  89             __current_ip = int_ip
  90         lock.release()
  91         return True
  92     lock.release()
  93     return False
  94
  95
  96 def is_cidr_issued(cidr):
  97     """
  98     Returns True if the CIDR is used.
  99
 100     :param cidr: The requested CIDR.
 101     :type cidr: ``str``
 102     :return: Returns True if the CIDR is used, else False.
 103     :rtype: ``bool``
 104     """
 105     if cidr is None:
 106         return False
 107
 108     int_ip = Net.cidr_2_int(cidr)
 109
 110     if int_ip in __issued_ips:
 111         return True
 112     return False
 113
 114
 115 def is_my_cidr(cidr, uuid):
 116     """
 117     Checks if the UUID and the used CIDR are related.
 118
 119     :param cidr: The issued CIDR.
 120     :type cidr: ``str``
 121     :param uuid: The Subnet UUID.
 122     :type uuid: ``str``
 123     :return: Returns False if the CIDR is None or if the CIDR is not issued. Else returns True.
 124     :rtype: ``bool``
 125     """
 126     if cidr is None:
 127         return False
 128
 129     int_ip = Net.cidr_2_int(cidr)
 130
 131     if not int_ip in __issued_ips:
 132         return False
 133
 134     if __issued_ips[int_ip] == uuid:
 135         return True
 136     return False
 137
 138
 139 def assign_cidr(cidr, uuid):
 140     """
 141     Allows a subnet to request a specific CIDR.
 142
 143     :param cidr: The requested CIDR.
 144     :type cidr: ``str``
 145     :param uuid: The Subnet UUID.
 146     :type uuid: ``str``
 147     :return: Returns False if the CIDR is None or if the CIDR is already issued. Returns True if the CIDR could be
 148      assigned to the UUID.
 149     """
 150     if cidr is None:
 151         return False
 152
 153     int_ip = Net.cidr_2_int(cidr)
 154
 155     if int_ip in __issued_ips:
 156         return False
 157
 158     global lock
 159     lock.acquire()
 160     __issued_ips[int_ip] = uuid
 161     lock.release()
 162     return True