linkchecker/linkcheck/network/iputil.py

295 lines
8.2 KiB
Python

# -*- coding: iso-8859-1 -*-
# Copyright (C) 2003-2014 Bastian Kleineidam
#
# 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
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
"""
Ip number related utility functions.
"""
import re
import socket
import struct
from .. import log, LOG_CHECK
# IP Adress regular expressions
# Note that each IPv4 octet can be encoded in dezimal, hexadezimal and octal.
_ipv4_num = r"\d{1,3}"
_ipv4_hex = r"0*[\da-f]{1,2}"
_ipv4_oct = r"0+[0-7]{0, 3}"
# XXX
_ipv4_num_4 = r"%s\.%s\.%s\.%s" % ((_ipv4_num,) * 4)
_ipv4_re = re.compile(r"^%s$" % _ipv4_num_4)
_ipv4_hex_4 = r"%s\.%s\.%s\.%s" % ((_ipv4_hex,) * 4)
# IPv4 encoded in octal, eg. 0x42.0x66.0x0d.0x63
_ipv4_oct = r"0*[0-7]{1,3}"
_ipv4_hex_4 = r"%s\.%s\.%s\.%s" % ((_ipv4_hex,) * 4)
# IPv6; See also rfc2373
_ipv6_num = r"[\da-f]{1,4}"
_ipv6_re = re.compile(r"^%s:%s:%s:%s:%s:%s:%s:%s$" % ((_ipv6_num,) * 8))
_ipv6_ipv4_re = re.compile(r"^%s:%s:%s:%s:%s:%s:" % ((_ipv6_num,) * 6) + \
r"%s$" % _ipv4_num_4)
_ipv6_abbr_re = re.compile(r"^((%s:){0,6}%s)?::((%s:){0,6}%s)?$" % \
((_ipv6_num,) * 4))
_ipv6_ipv4_abbr_re = re.compile(r"^((%s:){0,4}%s)?::((%s:){0,5})?" % \
((_ipv6_num,) * 3) + \
"%s$" % _ipv4_num_4)
# netmask regex
_host_netmask_re = re.compile(r"^%s/%s$" % (_ipv4_num_4, _ipv4_num_4))
_host_cidrmask_re = re.compile(r"^%s/\d{1,2}$" % _ipv4_num_4)
def expand_ipv6 (ip, num):
"""
Expand an IPv6 address with included :: to num octets.
@raise: ValueError on invalid IP addresses
"""
i = ip.find("::")
prefix = ip[:i]
suffix = ip[i + 2:]
count = prefix.count(":") + suffix.count(":")
if prefix:
count += 1
prefix = prefix + ":"
if suffix:
count += 1
suffix = ":" + suffix
if count >= num:
raise ValueError("invalid ipv6 number: %s" % ip)
fill = (num - count - 1) * "0:" + "0"
return prefix + fill + suffix
def expand_ip (ip):
"""
ipv6 addresses are expanded to full 8 octets, all other
addresses are left untouched
return a tuple (ip, num) where num==1 if ip is a numeric ip, 0
otherwise.
"""
if _ipv4_re.match(ip) or \
_ipv6_re.match(ip) or \
_ipv6_ipv4_re.match(ip):
return (ip, 1)
if _ipv6_abbr_re.match(ip):
return (expand_ipv6(ip, 8), 1)
if _ipv6_ipv4_abbr_re.match(ip):
i = ip.rfind(":") + 1
return (expand_ipv6(ip[:i], 6) + ip[i:], 1)
return (ip, 0)
def is_valid_ip (ip):
"""
Return True if given ip is a valid IPv4 or IPv6 address.
"""
return is_valid_ipv4(ip) or is_valid_ipv6(ip)
def is_valid_ipv4 (ip):
"""
Return True if given ip is a valid IPv4 address.
"""
if not _ipv4_re.match(ip):
return False
a, b, c, d = [int(i) for i in ip.split(".")]
return a <= 255 and b <= 255 and c <= 255 and d <= 255
def is_valid_ipv6 (ip):
"""
Return True if given ip is a valid IPv6 address.
"""
# XXX this is not complete: check ipv6 and ipv4 semantics too here
if not (_ipv6_re.match(ip) or _ipv6_ipv4_re.match(ip) or
_ipv6_abbr_re.match(ip) or _ipv6_ipv4_abbr_re.match(ip)):
return False
return True
def is_valid_cidrmask (mask):
"""
Check if given mask is a valid network bitmask in CIDR notation.
"""
return 0 <= mask <= 32
def dq2num (ip):
"""
Convert decimal dotted quad string to long integer.
"""
return struct.unpack('!L', socket.inet_aton(ip))[0]
def num2dq (n):
"""
Convert long int to dotted quad string.
"""
return socket.inet_ntoa(struct.pack('!L', n))
def cidr2mask (n):
"""
Return a mask where the n left-most of 32 bits are set.
"""
return ((1L << n) - 1) << (32 - n)
def netmask2mask (ip):
"""
Return a mask of bits as a long integer.
"""
return dq2num(ip)
def mask2netmask (mask):
"""
Return dotted quad string as netmask.
"""
return num2dq(mask)
def dq2net (ip, mask):
"""
Return a tuple (network ip, network mask) for given ip and mask.
"""
return dq2num(ip) & mask
def dq_in_net (n, mask):
"""
Return True iff numerical ip n is in given network.
"""
return (n & mask) == mask
def host_in_set (ip, hosts, nets):
"""
Return True if given ip is in host or network list.
"""
if ip in hosts:
return True
if is_valid_ipv4(ip):
n = dq2num(ip)
for net in nets:
if dq_in_net(n, net):
return True
return False
def strhosts2map (strhosts):
"""
Convert a string representation of hosts and networks to
a tuple (hosts, networks).
"""
return hosts2map([s.strip() for s in strhosts.split(",") if s])
def hosts2map (hosts):
"""
Return a set of named hosts, and a list of subnets (host/netmask
adresses).
Only IPv4 host/netmasks are supported.
"""
hostset = set()
nets = []
for host in hosts:
if _host_cidrmask_re.match(host):
host, mask = host.split("/")
mask = int(mask)
if not is_valid_cidrmask(mask):
log.error(LOG_CHECK,
"CIDR mask %d is not a valid network mask", mask)
continue
if not is_valid_ipv4(host):
log.error(LOG_CHECK, "host %r is not a valid ip address", host)
continue
nets.append(dq2net(host, cidr2mask(mask)))
elif _host_netmask_re.match(host):
host, mask = host.split("/")
if not is_valid_ipv4(host):
log.error(LOG_CHECK, "host %r is not a valid ip address", host)
continue
if not is_valid_ipv4(mask):
log.error(LOG_CHECK,
"mask %r is not a valid ip network mask", mask)
continue
nets.append(dq2net(host, netmask2mask(mask)))
elif is_valid_ip(host):
hostset.add(expand_ip(host)[0])
else:
hostset |= set(resolve_host(host))
return (hostset, nets)
def map2hosts (hostmap):
"""
Convert a tuple (hosts, networks) into a host/network list
suitable for storing in a config file.
"""
ret = hostmap[0].copy()
for net, mask in hostmap[1]:
ret.add("%s/%d" % (num2dq(net), mask2netmask(mask)))
return ret
def lookup_ips (ips):
"""
Return set of host names that resolve to given ips.
"""
hosts = set()
for ip in ips:
try:
hosts.add(socket.gethostbyaddr(ip)[0])
except socket.error:
hosts.add(ip)
return hosts
def resolve_host (host):
"""
@host: hostname or IP address
Return list of ip numbers for given host.
"""
ips = []
try:
for res in socket.getaddrinfo(host, None, 0, socket.SOCK_STREAM):
# res is a tuple (address family, socket type, protocol,
# canonical name, socket address)
# add first ip of socket address
ips.append(res[4][0])
except socket.error:
log.info(LOG_CHECK, "Ignored invalid host %r", host)
return ips
def obfuscate_ip(ip):
"""Obfuscate given host in IP form.
@ip: IPv4 address string
@return: hexadecimal IP string ('0x1ab...')
@raise: ValueError on invalid IP addresses
"""
if is_valid_ipv4(ip):
res = "0x%s" % "".join(hex(int(x))[2:] for x in ip.split("."))
else:
raise ValueError('Invalid IP value %r' % ip)
assert is_obfuscated_ip(res), '%r obfuscation error' % res
return res
is_obfuscated_ip = re.compile(r"^(0x[a-f0-9]+|[0-9]+)$").match