| 1 | # ipaddr.py -- handle IP addresses and set of IP addresses. |
| 2 | # Copyright (C) 1996-2000 Cendio Systems AB |
| 3 | # |
| 4 | # This program is free software; you can redistribute it and/or modify |
| 5 | # it under the terms of the GNU General Public License as published by |
| 6 | # the Free Software Foundation; either version 2 of the License, or |
| 7 | # (at your option) any later version. |
| 8 | # |
| 9 | # This program is distributed in the hope that it will be useful, |
| 10 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | # GNU General Public License for more details. |
| 13 | # |
| 14 | # You should have received a copy of the GNU General Public License |
| 15 | # along with this program; if not, write to the Free Software |
| 16 | # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 17 | |
| 18 | """IP address manipulation. |
| 19 | |
| 20 | This module is useful if you need to manipulate IP addresses or sets |
| 21 | of IP addresses. |
| 22 | |
| 23 | The main classes are: |
| 24 | |
| 25 | ipaddr -- a single IP address. |
| 26 | netmask -- a netmask. |
| 27 | network -- an IP address/netmask combination. It is often, but |
| 28 | not always, better to use the ip_set class instead. |
| 29 | ip_set -- a set of IP addresses, that may or may not be adjacent. |
| 30 | |
| 31 | So, what can you do with this module? As a simple example of the kind |
| 32 | of things this module can do, this code computes the set of all IP |
| 33 | addresses except 127.0.0.0/8 and prints it, expressed as a union of |
| 34 | network/netmask pairs. |
| 35 | |
| 36 | import ipaddr |
| 37 | |
| 38 | s = ipaddr.ip_set() |
| 39 | s.add_network(ipaddr.network('127.0.0.0', '255.0.0.0', |
| 40 | ipaddr.DEMAND_FILTER)) |
| 41 | for nw in s.complement().as_list_of_networks(): |
| 42 | print nw.ip_str() + '/' + nw.mask.netmask_bits_str |
| 43 | |
| 44 | Errors are reported by raising an exception from the following |
| 45 | exception hierarcy: |
| 46 | |
| 47 | Exception # The standard Python base exception class. |
| 48 | | |
| 49 | +-- BadType # Only raised if the programmer makes an error. |
| 50 | +-- IpError # Base class for errors that depend on the data. |
| 51 | | |
| 52 | +-- SetNotRepresentable |
| 53 | +-- BrokenIpAddress |
| 54 | | | |
| 55 | | +-- PartNegative |
| 56 | | +-- PartOverflow |
| 57 | | |
| 58 | +-- BrokenNetmask |
| 59 | | | |
| 60 | | +-- NeedOneBit |
| 61 | | +-- NeedMoreBits |
| 62 | | +-- NeedLessBits |
| 63 | | |
| 64 | +-- BrokenNetwork |
| 65 | | |
| 66 | +-- EmptyIpAddress |
| 67 | +-- EmptyNetmask |
| 68 | +-- BrokenNetworkAddress |
| 69 | +-- NetworkAddressClash |
| 70 | +-- BroadcastAddressClash |
| 71 | |
| 72 | BadType may be raised at any time if the programmer makes an error |
| 73 | (such as passing a dictionary to a function that expects a string). |
| 74 | SetNotRepresentable may be raised by ip_set.as_str_range(). All other |
| 75 | exceptions are raised from the constructors and helper functions only. |
| 76 | |
| 77 | The following constants are present in this module: |
| 78 | |
| 79 | DEMAND_NONE See class network. |
| 80 | DEMAND_FILTER See class network. |
| 81 | DEMAND_NETWORK See class network. |
| 82 | DEMAND_INTERFACE See class network. |
| 83 | |
| 84 | hostmask A netmask object with all 32 bits set. |
| 85 | complete_network A network object representing all IP addresses. |
| 86 | complete_set An ip_set object representing all IP addresses. |
| 87 | broadcast_network A network object representing 255.255.255.255. |
| 88 | broadcast_set An ip_set object representing 255.255.255.255. |
| 89 | |
| 90 | The as_ipaddr function can be used when you have an object that you |
| 91 | know are an ipaddr or network, and you want to get the ipaddr part. |
| 92 | |
| 93 | All the other functions in this module are internal helper functions, |
| 94 | and they should not be used. |
| 95 | |
| 96 | The internal representation used for IP addresses is currently a long |
| 97 | number. That may change in the future, so where the internal |
| 98 | representation is visible, you should do nothing with it except |
| 99 | compare it to None. |
| 100 | |
| 101 | This module was developed by Cendio Systems AB for use in the Fuego |
| 102 | Firewall. Bug reports can be sent to Per Cederqvist <ceder@cendio.se> |
| 103 | who is currently acting as maintainer for this module. |
| 104 | |
| 105 | Brief history: |
| 106 | 1997-03-11 Module created, and used internally. |
| 107 | 2000-03-09 1.0: First non-public beta release outside of Cendio Systems. |
| 108 | 2000-03-17 1.1: First public release under the GNU GPL license. |
| 109 | |
| 110 | """ |
| 111 | |
| 112 | |
| 113 | import copy |
| 114 | import string |
| 115 | import types |
| 116 | |
| 117 | # The error messages are marked with a call to this function, so that |
| 118 | # they can easily be found and translated. |
| 119 | def _(s): |
| 120 | return s |
| 121 | |
| 122 | # The exception hierarchy. |
| 123 | class IpError(Exception): |
| 124 | """Base class for errors that are cause by errors in input data. |
| 125 | """ |
| 126 | def __str__(self): |
| 127 | return self.format % self.args |
| 128 | |
| 129 | class SetNotRepresentable(IpError): |
| 130 | format = _("The set of IP addresses cannot be represented " |
| 131 | "as a single network range") |
| 132 | |
| 133 | class BrokenIpAddress(IpError): |
| 134 | format = _("Felaktigt IP-nummer") |
| 135 | |
| 136 | class PartNegative(BrokenIpAddress): |
| 137 |