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#!/usr/bin/python
from __future__ import division
import SocketServer
import socket
import select
from optparse import OptionParser
import datetime
import errno
import gnutls.crypto
import gnutls.connection
import gnutls.errors
import ConfigParser
import sys
import re
import os
import signal
from sets import Set
import subprocess
class Client(object):
def __init__(self, name=None, options=None, dn=None,
password=None, passfile=None, fqdn=None,
timeout=None, interval=-1):
self.name = name
self.dn = dn
if password:
self.password = password
elif passfile:
self.password = open(passfile).readall()
else:
print "No Password or Passfile in client config file"
# raise RuntimeError XXX
self.password = "gazonk"
self.fqdn = fqdn # string
self.created = datetime.datetime.now()
self.last_seen = None # datetime.datetime()
if timeout is None:
timeout = options.timeout
self.timeout = timeout # datetime.timedelta()
if interval == -1:
interval = options.interval
else:
interval = string_to_delta(interval)
self.interval = interval # datetime.timedelta()
self.next_check = datetime.datetime.now() # datetime.datetime()
# Note: next_check may be in the past if checker is not None
self.checker = None # or a subprocess.Popen()
def check_action(self):
"""The checker said something and might have completed.
Check if is has, and take appropriate actions."""
if self.checker.poll() is None:
# False alarm, no result yet
#self.checker.read()
#print "Checker for %(name)s said nothing?" % vars(self)
return
now = datetime.datetime.now()
if self.checker.returncode == 0:
print "Checker for %(name)s succeeded" % vars(self)
self.last_seen = now
else:
print "Checker for %(name)s failed" % vars(self)
while self.next_check <= now:
self.next_check += self.interval
self.checker = None
handle_request = check_action
def start_checker(self):
self.stop_checker()
try:
self.checker = subprocess.Popen("sleep 10; fping -q -- %s"
% re.escape(self.fqdn),
stdout=subprocess.PIPE,
close_fds=True,
shell=True, cwd="/")
except subprocess.OSError, e:
print "Failed to start subprocess:", e
def stop_checker(self):
if self.checker is None:
return
os.kill(self.checker.pid, signal.SIGTERM)
if self.checker.poll() is None:
os.kill(self.checker.pid, signal.SIGKILL)
self.checker = None
__del__ = stop_checker
def fileno(self):
if self.checker is None:
return None
return self.checker.stdout.fileno()
def next_stop(self):
"""The time when something must be done about this client
May be in the past."""
if self.last_seen is None:
# This client has never been seen
next_timeout = self.created + self.timeout
else:
next_timeout = self.last_seen + self.timeout
if self.checker is None:
return min(next_timeout, self.next_check)
else:
return next_timeout
def still_valid(self, now=None):
"""Has this client's timeout not passed?"""
if now is None:
now = datetime.datetime.now()
if self.last_seen is None:
return now < (self.created + self.timeout)
else:
return now < (self.last_seen + self.timeout)
def it_is_time_to_check(self, now=None):
if now is None:
now = datetime.datetime.now()
return self.next_check <= now
class server_metaclass(type):
"Common behavior for the UDP and TCP server classes"
def __new__(cls, name, bases, attrs):
attrs["address_family"] = socket.AF_INET6
attrs["allow_reuse_address"] = True
def server_bind(self):
if self.options.interface:
if not hasattr(socket, "SO_BINDTODEVICE"):
# From /usr/include/asm-i486/socket.h
socket.SO_BINDTODEVICE = 25
try:
self.socket.setsockopt(socket.SOL_SOCKET,
socket.SO_BINDTODEVICE,
self.options.interface)
except socket.error, error:
if error[0] == errno.EPERM:
print "Warning: No permission to bind to interface", \
self.options.interface
else:
raise error
return super(type(self), self).server_bind()
attrs["server_bind"] = server_bind
def init(self, *args, **kwargs):
if "options" in kwargs:
self.options = kwargs["options"]
del kwargs["options"]
if "clients" in kwargs:
self.clients = kwargs["clients"]
del kwargs["clients"]
if "credentials" in kwargs:
self.credentials = kwargs["credentials"]
del kwargs["credentials"]
return super(type(self), self).__init__(*args, **kwargs)
attrs["__init__"] = init
return type.__new__(cls, name, bases, attrs)
class udp_handler(SocketServer.DatagramRequestHandler, object):
def handle(self):
self.wfile.write("Polo")
print "UDP request answered"
class IPv6_UDPServer(SocketServer.UDPServer, object):
__metaclass__ = server_metaclass
def verify_request(self, request, client_address):
print "UDP request came"
return request[0] == "Marco"
class tcp_handler(SocketServer.BaseRequestHandler, object):
def handle(self):
print "TCP request came"
print "Request:", self.request
print "Client Address:", self.client_address
print "Server:", self.server
session = gnutls.connection.ServerSession(self.request,
self.server.credentials)
session.handshake()
if session.peer_certificate:
print "DN:", session.peer_certificate.subject
try:
session.verify_peer()
except gnutls.errors.CertificateError, error:
print "Verify failed", error
session.bye()
return
try:
session.send([client.password
for client in self.server.clients
if (client.dn ==
session.peer_certificate.subject)][0])
except IndexError:
session.send("gazonk")
# Log maybe? XXX
session.bye()
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
__metaclass__ = server_metaclass
def string_to_delta(interval):
"""Parse a string and return a datetime.timedelta
>>> string_to_delta('7d')
datetime.timedelta(7)
>>> string_to_delta('60s')
datetime.timedelta(0, 60)
>>> string_to_delta('60m')
datetime.timedelta(0, 3600)
>>> string_to_delta('24h')
datetime.timedelta(1)
>>> string_to_delta(u'1w')
datetime.timedelta(7)
"""
try:
suffix=unicode(interval[-1])
value=int(interval[:-1])
if suffix == u"d":
delta = datetime.timedelta(value)
elif suffix == u"s":
delta = datetime.timedelta(0, value)
elif suffix == u"m":
delta = datetime.timedelta(0, 0, 0, 0, value)
elif suffix == u"h":
delta = datetime.timedelta(0, 0, 0, 0, 0, value)
elif suffix == u"w":
delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
else:
raise ValueError
except (ValueError, IndexError):
raise ValueError
return delta
def main():
parser = OptionParser()
parser.add_option("-i", "--interface", type="string",
default="eth0", metavar="IF",
help="Interface to bind to")
parser.add_option("--cert", type="string", default="cert.pem",
metavar="FILE",
help="Public key certificate to use")
parser.add_option("--key", type="string", default="key.pem",
metavar="FILE",
help="Private key to use")
parser.add_option("--ca", type="string", default="ca.pem",
metavar="FILE",
help="Certificate Authority certificate to use")
parser.add_option("--crl", type="string", default="crl.pem",
metavar="FILE",
help="Certificate Revokation List to use")
parser.add_option("-p", "--port", type="int", default=49001,
help="Port number to receive requests on")
parser.add_option("--dh", type="int", metavar="BITS",
help="DH group to use")
parser.add_option("-t", "--timeout", type="string", # Parsed later
default="15m",
help="Amount of downtime allowed for clients")
parser.add_option("--interval", type="string", # Parsed later
default="5m",
help="How often to check that a client is up")
parser.add_option("--check", action="store_true", default=False,
help="Run self-test")
(options, args) = parser.parse_args()
if options.check:
import doctest
doctest.testmod()
sys.exit()
# Parse the time arguments
try:
options.timeout = string_to_delta(options.timeout)
except ValueError:
parser.error("option --timeout: Unparseable time")
try:
options.interval = string_to_delta(options.interval)
except ValueError:
parser.error("option --interval: Unparseable time")
cert = gnutls.crypto.X509Certificate(open(options.cert).read())
key = gnutls.crypto.X509PrivateKey(open(options.key).read())
ca = gnutls.crypto.X509Certificate(open(options.ca).read())
crl = gnutls.crypto.X509CRL(open(options.crl).read())
cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
# Parse config file
defaults = {}
client_config_object = ConfigParser.SafeConfigParser(defaults)
client_config_object.read("mandos-clients.conf")
clients = Set(Client(name=section, options=options,
**(dict(client_config_object\
.items(section))))
for section in client_config_object.sections())
in6addr_any = "::"
udp_server = IPv6_UDPServer((in6addr_any, options.port),
udp_handler,
options=options)
tcp_server = IPv6_TCPServer((in6addr_any, options.port),
tcp_handler,
options=options,
clients=clients,
credentials=cred)
while True:
if not clients:
break
try:
next_stop = min(client.next_stop() for client in clients)
now = datetime.datetime.now()
if next_stop > now:
delay = next_stop - now
delay_seconds = (delay.days * 24 * 60 * 60
+ delay.seconds
+ delay.microseconds / 1000000)
clients_with_checkers = tuple(client for client in
clients
if client.checker
is not None)
input_checks = (udp_server, tcp_server) \
+ clients_with_checkers
print "Waiting for network",
if clients_with_checkers:
print "and checkers for:",
for client in clients_with_checkers:
print client.name,
print
input, out, err = select.select(input_checks, (), (),
delay_seconds)
for obj in input:
obj.handle_request()
# start new checkers
for client in clients:
if client.it_is_time_to_check(now=now) and \
client.checker is None:
print "Starting checker for client %(name)s" \
% vars(client)
client.start_checker()
# delete timed-out clients
for client in clients.copy():
if not client.still_valid(now=now):
# log xxx
print "Removing client %(name)s" % vars(client)
clients.remove(client)
except KeyboardInterrupt:
break
# Cleanup here
for client in clients:
client.stop_checker()
if __name__ == "__main__":
main()
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