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| Current File : //usr/lib/python2.7/site-packages/firewall/functions.py |
# -*- coding: utf-8 -*-
#
# Copyright (C) 2007,2008,2011,2012 Red Hat, Inc.
#
# Authors:
# Thomas Woerner <twoerner@redhat.com>
#
# 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, see <http://www.gnu.org/licenses/>.
#
__all__ = [ "PY2", "getPortID", "getPortRange", "portStr", "getServiceName",
"checkIP", "checkIP6", "checkIPnMask", "checkIP6nMask",
"checkProtocol", "checkInterface", "checkUINT32",
"firewalld_is_active", "tempFile", "readfile", "writefile",
"enable_ip_forwarding", "get_nf_conntrack_helper_setting",
"set_nf_conntrack_helper_setting", "check_port", "check_address",
"check_single_address", "check_mac", "uniqify", "ppid_of_pid",
"max_zone_name_len", "checkUser", "checkUid", "checkCommand",
"checkContext", "joinArgs", "splitArgs",
"b2u", "u2b", "u2b_if_py2" ]
import socket
import os
import os.path
import shlex
import pipes
import string
import sys
import tempfile
from firewall.core.logger import log
from firewall.config import FIREWALLD_TEMPDIR, FIREWALLD_PIDFILE
PY2 = sys.version < '3'
def getPortID(port):
""" Check and Get port id from port string or port id using socket.getservbyname
@param port port string or port id
@return Port id if valid, -1 if port can not be found and -2 if port is too big
"""
if isinstance(port, int):
_id = port
else:
if port:
port = port.strip()
try:
_id = int(port)
except ValueError:
try:
_id = socket.getservbyname(port)
except socket.error:
return -1
if _id > 65535:
return -2
return _id
def getPortRange(ports):
""" Get port range for port range string or single port id
@param ports an integer or port string or port range string
@return Array containing start and end port id for a valid range or -1 if port can not be found and -2 if port is too big for integer input or -1 for invalid ranges or None if the range is ambiguous.
"""
# "<port-id>" case
if isinstance(ports, int) or ports.isdigit():
id1 = getPortID(ports)
if id1 >= 0:
return (id1,)
return id1
splits = ports.split("-")
# "<port-id>-<port-id>" case
if len(splits) == 2 and splits[0].isdigit() and splits[1].isdigit():
id1 = getPortID(splits[0])
id2 = getPortID(splits[1])
if id1 >= 0 and id2 >= 0:
if id1 < id2:
return (id1, id2)
elif id1 > id2:
return (id2, id1)
else: # ids are the same
return (id1,)
# everything else "<port-str>[-<port-str>]"
matched = [ ]
for i in range(len(splits), 0, -1):
id1 = getPortID("-".join(splits[:i]))
port2 = "-".join(splits[i:])
if len(port2) > 0:
id2 = getPortID(port2)
if id1 >= 0 and id2 >= 0:
if id1 < id2:
matched.append((id1, id2))
elif id1 > id2:
matched.append((id2, id1))
else:
matched.append((id1, ))
else:
if id1 >= 0:
matched.append((id1,))
if i == len(splits):
# full match, stop here
break
if len(matched) < 1:
return -1
elif len(matched) > 1:
return None
return matched[0]
def portStr(port, delimiter=":"):
""" Create port and port range string
@param port port or port range int or [int, int]
@param delimiter of the output string for port ranges, default ':'
@return Port or port range string, empty string if port isn't specified, None if port or port range is not valid
"""
if port == "":
return ""
_range = getPortRange(port)
if isinstance(_range, int) and _range < 0:
return None
elif len(_range) == 1:
return "%s" % _range
else:
return "%s%s%s" % (_range[0], delimiter, _range[1])
def portInPortRange(port, range):
_port = getPortID(port)
_range = getPortRange(range)
if len(_range) == 1:
return _port == getPortID(_range[0])
if len(_range) == 2 and \
_port >= getPortID(_range[0]) and _port <= getPortID(_range[1]):
return True
return False
def getServiceName(port, proto):
""" Check and Get service name from port and proto string combination using socket.getservbyport
@param port string or id
@param protocol string
@return Service name if port and protocol are valid, else None
"""
try:
name = socket.getservbyport(int(port), proto)
except socket.error:
return None
return name
def checkIP(ip):
""" Check IPv4 address.
@param ip address string
@return True if address is valid, else False
"""
try:
socket.inet_pton(socket.AF_INET, ip)
except socket.error:
return False
return True
def normalizeIP6(ip):
""" Normalize the IPv6 address
This is mostly about converting URL-like IPv6 address to normal ones.
e.g. [1234::4321] --> 1234:4321
"""
return ip.strip("[]")
def checkIP6(ip):
""" Check IPv6 address.
@param ip address string
@return True if address is valid, else False
"""
try:
socket.inet_pton(socket.AF_INET6, normalizeIP6(ip))
except socket.error:
return False
return True
def checkIPnMask(ip):
if "/" in ip:
addr = ip[:ip.index("/")]
mask = ip[ip.index("/")+1:]
if len(addr) < 1 or len(mask) < 1:
return False
else:
addr = ip
mask = None
if not checkIP(addr):
return False
if mask:
if "." in mask:
return checkIP(mask)
else:
try:
i = int(mask)
except ValueError:
return False
if i < 0 or i > 32:
return False
return True
def checkIP6nMask(ip):
if "/" in ip:
addr = ip[:ip.index("/")]
mask = ip[ip.index("/")+1:]
if len(addr) < 1 or len(mask) < 1:
return False
else:
addr = ip
mask = None
if not checkIP6(addr):
return False
if mask:
try:
i = int(mask)
except ValueError:
return False
if i < 0 or i > 128:
return False
return True
def checkProtocol(protocol):
try:
i = int(protocol)
except ValueError:
# string
try:
socket.getprotobyname(protocol)
except socket.error:
return False
else:
if i < 0 or i > 255:
return False
return True
def checkInterface(iface):
""" Check interface string
@param interface string
@return True if interface is valid (maximum 16 chars and does not contain ' ', '/', '!', ':', '*'), else False
"""
if not iface or len(iface) > 16:
return False
for ch in [ ' ', '/', '!', '*' ]:
# !:* are limits for iptables <= 1.4.5
if ch in iface:
return False
# disabled old iptables check
#if iface == "+":
# # limit for iptables <= 1.4.5
# return False
return True
def checkUINT32(val):
try:
x = int(val, 0)
except ValueError:
return False
else:
if x >= 0 and x <= 4294967295:
return True
return False
def firewalld_is_active():
""" Check if firewalld is active
@return True if there is a firewalld pid file and the pid is used by firewalld
"""
if not os.path.exists(FIREWALLD_PIDFILE):
return False
try:
with open(FIREWALLD_PIDFILE, "r") as fd:
pid = fd.readline()
except Exception:
return False
if not os.path.exists("/proc/%s" % pid):
return False
try:
with open("/proc/%s/cmdline" % pid, "r") as fd:
cmdline = fd.readline()
except Exception:
return False
if "firewalld" in cmdline:
return True
return False
def tempFile():
try:
if not os.path.exists(FIREWALLD_TEMPDIR):
os.mkdir(FIREWALLD_TEMPDIR, 0o750)
return tempfile.NamedTemporaryFile(mode='wt', prefix="temp.",
dir=FIREWALLD_TEMPDIR, delete=False)
except Exception as msg:
log.error("Failed to create temporary file: %s" % msg)
raise
return None
def readfile(filename):
try:
with open(filename, "r") as f:
return f.readlines()
except Exception as e:
log.error('Failed to read file "%s": %s' % (filename, e))
return None
def writefile(filename, line):
try:
with open(filename, "w") as f:
f.write(line)
except Exception as e:
log.error('Failed to write to file "%s": %s' % (filename, e))
return False
return True
def enable_ip_forwarding(ipv):
if ipv == "ipv4":
return writefile("/proc/sys/net/ipv4/ip_forward", "1\n")
elif ipv == "ipv6":
return writefile("/proc/sys/net/ipv6/conf/all/forwarding", "1\n")
return False
def get_nf_conntrack_short_name(module):
return module.replace("_","-").replace("nf-conntrack-", "")
def get_nf_conntrack_helper_setting():
try:
return int(readfile("/proc/sys/net/netfilter/nf_conntrack_helper")[0])
except Exception:
log.warning("Failed to get and parse nf_conntrack_helper setting")
return 0
def set_nf_conntrack_helper_setting(flag):
return writefile("/proc/sys/net/netfilter/nf_conntrack_helper",
"1\n" if flag else "0\n")
def check_port(port):
_range = getPortRange(port)
if _range == -2 or _range == -1 or _range is None or \
(len(_range) == 2 and _range[0] >= _range[1]):
if _range == -2:
log.debug2("'%s': port > 65535" % port)
elif _range == -1:
log.debug2("'%s': port is invalid" % port)
elif _range is None:
log.debug2("'%s': port is ambiguous" % port)
elif len(_range) == 2 and _range[0] >= _range[1]:
log.debug2("'%s': range start >= end" % port)
return False
return True
def check_address(ipv, source):
if ipv == "ipv4":
return checkIPnMask(source)
elif ipv == "ipv6":
return checkIP6nMask(source)
else:
return False
def check_single_address(ipv, source):
if ipv == "ipv4":
return checkIP(source)
elif ipv == "ipv6":
return checkIP6(source)
else:
return False
def check_mac(mac):
if len(mac) == 12+5:
# 0 1 : 3 4 : 6 7 : 9 10 : 12 13 : 15 16
for i in (2, 5, 8, 11, 14):
if mac[i] != ":":
return False
for i in (0, 1, 3, 4, 6, 7, 9, 10, 12, 13, 15, 16):
if mac[i] not in string.hexdigits:
return False
return True
return False
def uniqify(_list):
# removes duplicates from list, whilst preserving order
output = []
for x in _list:
if x not in output:
output.append(x)
return output
def ppid_of_pid(pid):
""" Get parent for pid """
try:
f = os.popen("ps -o ppid -h -p %d 2>/dev/null" % pid)
pid = int(f.readlines()[0].strip())
f.close()
except Exception:
return None
return pid
def max_zone_name_len():
"""
Netfilter limits length of chain to (currently) 28 chars.
The longest chain we create is FWDI_<zone>_allow,
which leaves 28 - 11 = 17 chars for <zone>.
"""
from firewall.core.base import SHORTCUTS
longest_shortcut = max(map(len, SHORTCUTS.values()))
return 28 - (longest_shortcut + len("__allow"))
def checkUser(user):
if len(user) < 1 or len(user) > os.sysconf('SC_LOGIN_NAME_MAX'):
return False
for c in user:
if c not in string.ascii_letters and \
c not in string.digits and \
c not in [ ".", "-", "_", "$" ]:
return False
return True
def checkUid(uid):
if isinstance(uid, str):
try:
uid = int(uid)
except ValueError:
return False
if uid >= 0 and uid <= 2**31-1:
return True
return False
def checkCommand(command):
if len(command) < 1 or len(command) > 1024:
return False
for ch in [ "|", "\n", "\0" ]:
if ch in command:
return False
if command[0] != "/":
return False
return True
def checkContext(context):
splits = context.split(":")
if len(splits) not in [4, 5]:
return False
# user ends with _u if not root
if splits[0] != "root" and splits[0][-2:] != "_u":
return False
# role ends with _r
if splits[1][-2:] != "_r":
return False
# type ends with _t
if splits[2][-2:] != "_t":
return False
# level might also contain :
if len(splits[3]) < 1:
return False
return True
def joinArgs(args):
if "quote" in dir(shlex):
return " ".join(shlex.quote(a) for a in args)
else:
return " ".join(pipes.quote(a) for a in args)
def splitArgs(_string):
if PY2 and isinstance(_string, unicode): # noqa: F821
# Python2's shlex doesn't like unicode
_string = u2b(_string)
splits = shlex.split(_string)
return map(b2u, splits)
else:
return shlex.split(_string)
def b2u(_string):
""" bytes to unicode """
if isinstance(_string, bytes):
return _string.decode('UTF-8', 'replace')
return _string
def u2b(_string):
""" unicode to bytes """
if not isinstance(_string, bytes):
return _string.encode('UTF-8', 'replace')
return _string
def u2b_if_py2(_string):
""" unicode to bytes only if Python 2"""
if PY2 and isinstance(_string, unicode): # noqa: F821
return _string.encode('UTF-8', 'replace')
return _string