check_xmppng/check_xmppng
Jan Dittberner 11a16bb362 Improve human readable output
This change introduces more readable and useful output by adding the
certificate expiration to the human readable string. The response time
is now formatted too.
2015-12-29 22:17:59 +01:00

584 lines
20 KiB
Python
Executable file

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Nagios compatible check for XMPP servers.
# Copyright (C) 2015 Jan Dittberner
#
# 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 3 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/>.
#
from __future__ import absolute_import
from datetime import datetime
from select import select
from xml.sax.handler import ContentHandler, feature_namespaces
import logging
import os.path
import socket
import ssl
from defusedxml.sax import make_parser
import nagiosplugin
__author__ = "Jan Dittberner"
__version__ = "0.2.dev1"
NS_IETF_XMPP_SASL = 'urn:ietf:params:xml:ns:xmpp-sasl'
NS_IETF_XMPP_TLS = 'urn:ietf:params:xml:ns:xmpp-tls'
NS_IETF_XMPP_STREAMS = 'urn:ietf:params:xml:ns:xmpp-streams'
NS_JABBER_CAPS = 'http://jabber.org/protocol/caps'
NS_ETHERX_STREAMS = 'http://etherx.jabber.org/streams'
XMPP_STATE_NEW = 'new'
XMPP_STATE_STREAM_START = 'started'
XMPP_STATE_RECEIVED_FEATURES = 'received features'
XMPP_STATE_FINISHED = 'finished'
XMPP_STATE_ERROR = 'error'
XMPP_STATE_PROCEED_STARTTLS = 'proceed with starttls'
_LOG = logging.getLogger('nagiosplugin')
class XmppException(Exception):
"""
Custom exception class.
"""
def __init__(self, message):
self.message = message
super(XmppException, self).__init__()
class XmppStreamError(object):
"""
XMPP stream error class.
"""
condition = None
text = None
other_elements = {}
def str(self):
if self.text:
return "{condition}: {text}".format(
condition=self.condition, text=self.text)
return self.condition
class XmppResponseHandler(ContentHandler):
"""
SAX content handler for XMPP stream content.
"""
seen_elements = set()
mechanisms = []
starttls = False
tlsrequired = False
capabilities = {}
state = XMPP_STATE_NEW
streaminfo = None
inelem = []
level = 0
def __init__(self, expect_starttls):
self.expect_starttls = expect_starttls
super(XmppResponseHandler, self).__init__()
def startElementNS(self, name, qname, attrs):
self.inelem.append(name)
self.seen_elements.add(name)
if name == (NS_ETHERX_STREAMS, 'stream'):
self.state = XMPP_STATE_STREAM_START
self.streaminfo = dict([
(qname, attrs.getValueByQName(qname)) for
qname in attrs.getQNames()])
elif name == (NS_IETF_XMPP_TLS, 'starttls'):
self.starttls = True
elif (
self.inelem[-2] == (NS_IETF_XMPP_TLS, 'starttls') and
name == (NS_IETF_XMPP_TLS, 'required')
):
self.tlsrequired = True
_LOG.info("info other side requires TLS")
elif name == (NS_JABBER_CAPS, 'c'):
for qname in attrs.getQNames():
self.capabilities[qname] = attrs.getValueByQName(qname)
elif name == (NS_ETHERX_STREAMS, 'error'):
self.state = XMPP_STATE_ERROR
self.errorinstance = XmppStreamError()
elif (
self.state == XMPP_STATE_ERROR and
name != (NS_IETF_XMPP_STREAMS, 'text')
):
if name[0] == NS_IETF_XMPP_STREAMS:
self.errorinstance.condition = name[1]
else:
self.errorinstance.other_elements[name] = {'attrs': dict([
(qname, attrs.getValueByQName(qname)) for
qname in attrs.getQNames()
])}
_LOG.debug('start %s (%s)', name, attrs.getQNames())
def endElementNS(self, name, qname):
if name == (NS_ETHERX_STREAMS, 'features'):
self.state = XMPP_STATE_RECEIVED_FEATURES
elif name == (NS_ETHERX_STREAMS, 'stream'):
self.state = XMPP_STATE_FINISHED
elif name == (NS_ETHERX_STREAMS, 'error'):
raise XmppException("XMPP stream error: {error}".format(
error=self.errorinstance))
elif name == (NS_IETF_XMPP_TLS, 'proceed'):
self.state = XMPP_STATE_PROCEED_STARTTLS
elif name == (NS_IETF_XMPP_TLS, 'failure'):
raise XmppException("starttls initiation failed")
_LOG.debug('end %s', name)
del self.inelem[-1]
def characters(self, content):
elem = self.inelem[-1]
if elem == (NS_IETF_XMPP_SASL, 'mechanism'):
self.mechanisms.append(content)
elif self.state == XMPP_STATE_ERROR:
if elem == (NS_IETF_XMPP_STREAMS, 'text'):
self.errorinstance.text = content
else:
self.errorinstance.other_elements[elem]['text'] = content
else:
_LOG.warning('ignored content in %s: %s', self.inelem, content)
def is_valid_start(self):
if not self.state == XMPP_STATE_RECEIVED_FEATURES:
raise XmppException('XMPP feature list is not finished')
if self.expect_starttls is True and self.starttls is False:
raise XmppException('expected STARTTLS capable service')
if (
'version' not in self.streaminfo or
self.streaminfo['version'] != '1.0'
):
_LOG.warning(
'unknown stream version %s', self.streaminfo['version'])
return True
class Xmpp(nagiosplugin.Resource):
"""
Xmpp resource.
"""
state = nagiosplugin.Unknown
cause = None
socket = None
daysleft = None
def __init__(
self, host_address, port, ipv6, is_server, starttls,
servername, checkcerts, caroots
):
self.address = host_address
self.port = port
self.ipv6 = ipv6
self.is_server = is_server
self.starttls = starttls
self.servername = servername
self.checkcerts = checkcerts
self.caroots = caroots
self.make_parser()
self.set_content_handler()
def make_parser(self):
"""
Create and configure a SAX parser instance.
"""
self.parser = make_parser()
self.parser.setFeature(feature_namespaces, True)
def set_content_handler(self):
"""
Set the XMPP SAX content handler.
"""
self.contenthandler = XmppResponseHandler(
expect_starttls=self.starttls)
self.parser.setContentHandler(self.contenthandler)
def get_addrinfo(self):
"""
Perform the DNS lookup and return a list of potential socket address
tuples as returned by :py:method:`socket.getaddrinfo`.
"""
if self.ipv6 is None:
addrfamily = 0
elif self.ipv6 is True:
addrfamily = socket.AF_INET6
else:
addrfamily = socket.AF_INET
return socket.getaddrinfo(
self.address, self.port, addrfamily, socket.SOCK_STREAM,
socket.IPPROTO_TCP)
self.result = nagiosplugin.Critical
def open_socket(self, addrinfo):
"""
Open a client socket based on information in the addrinfo list of
tuples.
"""
for res in addrinfo:
af, socktype, proto, canonname, sa = res
try:
s = socket.socket(af, socktype, proto)
except socket.error:
s = None
continue
try:
s.connect(sa)
except socket.error:
s.close()
s = None
continue
break
if s is None:
raise XmppException("could not open socket")
return s
def handle_xmpp_stanza(
self, message_str, timeout=0.1, expected_state=None
):
"""
Handle a single XMPP message.
This method sends the message specified as ``message_str`` and receives
input from the remote XMPP server. The response message is passed to
the SAX parser.
The method can optionally check for a specific state of the SAX content
handler that can be specified as ``expected_state`` which needs to be
one of the ``XMPP_STATE_*`` constants specified in the head of this
file.
"""
self.socket.sendall(message_str.encode('utf-8'))
_LOG.debug("wrote %s", message_str)
chunks = []
while True:
rready, wready, xready = select([self.socket], [], [], timeout)
if self.socket in rready:
data = self.socket.recv(4096)
if not data:
break
chunks.append(data)
else:
break
xmltext = b''.join(chunks).decode('utf-8')
_LOG.debug("read %s", xmltext)
self.parser.feed(xmltext)
if (
expected_state is not None and
self.contenthandler.state != expected_state
):
raise XmppException(
"unexpected state %s" % self.contenthandler.state)
def start_stream(self):
"""
Start a XMPP conversation with the server.
"""
if self.is_server:
self.handle_xmpp_stanza((
"<?xml version='1.0' ?><stream:stream to='{servername}' "
"xmlns='jabber:server' "
"xmlns:stream='http://etherx.jabber.org/streams' "
"version='1.0'>"
).format(servername=self.servername),
expected_state=XMPP_STATE_RECEIVED_FEATURES)
else:
self.handle_xmpp_stanza((
"<?xml version='1.0' ?><stream:stream to='{servername}' "
"xmlns='jabber:client' "
"xmlns:stream='http://etherx.jabber.org/streams' "
"version='1.0'>"
).format(servername=self.servername),
expected_state=XMPP_STATE_RECEIVED_FEATURES)
def setup_ssl_context(self):
"""
Setup the SSL/TLS context.
"""
context = ssl.create_default_context()
context.options = ssl.OP_NO_SSLv2 | ssl.OP_NO_SSLv3
if not self.checkcerts:
context.check_hostname = False
context.verify_mode = ssl.CERT_NONE
else:
context.verify_mode = ssl.CERT_REQUIRED
if self.caroots:
if os.path.isfile(self.caroots):
kwargs = {'cafile': self.caroots}
else:
kwargs = {'capath': self.caroots}
context.load_verify_locations(**kwargs)
else:
context.load_default_certs()
stats = context.cert_store_stats()
if stats['x509_ca'] == 0:
_LOG.info(
"tried to load CA certificates from default locations, but"
" could not find any CA certificates.")
raise XmppException('no CA certificates found')
else:
_LOG.debug('certificate store statistics: %s', stats)
return context
def initiate_tls(self):
"""
Switch the client socket to TLS by performing a TLS handshake. If
certificate checks are requested the method checks the certificate
validity.
"""
_LOG.debug("start initiate_tls()")
self.handle_xmpp_stanza(
"<starttls xmlns='{xmlns}'/>".format(xmlns=NS_IETF_XMPP_TLS),
expected_state=XMPP_STATE_PROCEED_STARTTLS)
sslcontext = self.setup_ssl_context()
try:
self.socket = sslcontext.wrap_socket(
self.socket, server_hostname=self.servername)
_LOG.info("TLS socket setup successful")
except ssl.SSLError as ssle:
raise XmppException("SSL error %s" % ssle.strerror)
except ssl.CertificateError as certerr:
raise XmppException("Certificate error %s" % certerr)
self.starttls = False
# reset infos retrieved previously as written in RFC 3920 sec. 5.
self.parser.reset()
if self.checkcerts:
certinfo = self.socket.getpeercert()
_LOG.debug("got the following certificate info: %s", certinfo)
_LOG.info(
"certificate is valid from %s until %s",
certinfo['notBefore'], certinfo['notAfter'])
enddate = ssl.cert_time_to_seconds(certinfo['notAfter'])
remaining = datetime.fromtimestamp(enddate) - datetime.now()
self.daysleft = remaining.days
# start new parsing
self.make_parser()
self.set_content_handler()
self.start_stream()
if not self.contenthandler.is_valid_start():
raise XmppException("no valid response to XMPP client request")
_LOG.debug("end initiate_tls()")
def handle_xmpp(self):
"""
Perform the XMPP conversation.
"""
_LOG.debug("start handle_xmpp()")
self.start_stream()
if not self.contenthandler.is_valid_start():
raise XmppException("no valid response to XMPP client request")
if self.starttls is True or self.contenthandler.tlsrequired:
self.initiate_tls()
self.handle_xmpp_stanza("</stream:stream>")
_LOG.debug("end handle_xmpp()")
def probe(self):
"""
Entry point for the nagiosplugin.Resource APIs. Wraps the call to
:py:method:`Xmpp.handle_xmpp` and handles errors appropriately.
"""
start = datetime.now()
_LOG.debug("start probe() at %s", start)
try:
addrinfo = self.get_addrinfo()
self.socket = self.open_socket(addrinfo)
try:
self.handle_xmpp()
finally:
self.socket.close()
self.parser.close()
except socket.gaierror as e:
self.state = nagiosplugin.Critical
self.cause = str(e)
_LOG.debug("got an gaierror %s", e)
return nagiosplugin.Metric("time", "unknown")
except XmppException as e:
self.state = nagiosplugin.Critical
self.cause = e.message
_LOG.debug("got an XmppException %s", e)
yield nagiosplugin.Metric('time', 'unknown')
return nagiosplugin.Metric('daysleft', 'unknown')
end = datetime.now()
_LOG.debug("end probe() at %s", end)
yield nagiosplugin.Metric(
'time', (end - start).total_seconds(), 's', min=0)
yield nagiosplugin.Metric('daysleft', self.daysleft, 'd')
class XmppContext(nagiosplugin.ScalarContext):
"""
Context for checking the connection time and potential errors that occurred
during the XMPP check.
"""
def evaluate(self, metric, resource):
"""
Evaluate the time contained in the ``metric`` or the resource state in
case of an exception that has been handled during the check.
"""
if resource.cause:
return nagiosplugin.Result(resource.state, resource.cause, metric)
return super(XmppContext, self).evaluate(metric, resource)
class DaysValidContext(nagiosplugin.Context):
"""
Context for checking the certificate expiry date.
"""
fmt_hint = "less than {value} days"
def __init__(
self, name, warndays=0, critdays=0,
fmt_metric='certificate valid for {value} days'
):
super(DaysValidContext, self).__init__(name, fmt_metric=fmt_metric)
self.warning = nagiosplugin.Range('@%d:' % warndays)
self.critical = nagiosplugin.Range('@%d:' % critdays)
self.warndays = warndays
self.critdays = critdays
def evaluate(self, metric, resource):
if resource.checkcerts and metric.value is not None:
if self.critical.match(metric.value):
return nagiosplugin.Result(
nagiosplugin.Critical,
hint=self.fmt_hint.format(value=self.critdays),
metric=metric)
if self.warning.match(metric.value):
return nagiosplugin.Result(
nagiosplugin.Warn,
hint=self.fmt_hint.format(value=self.warndays),
metric=metric)
return nagiosplugin.Result(
nagiosplugin.Ok, "", metric)
return nagiosplugin.Result(nagiosplugin.Ok)
def performance(self, metric, resource):
if resource.checkcerts and metric.value is not None:
return nagiosplugin.Performance('daysvalid', metric.value, 'd')
return None
class XmppSummary(nagiosplugin.Summary):
"""
Summary instance that outputs all metrics if the check results are ok.
"""
def ok(self, results):
return ", ".join([str(res) for res in results])
@nagiosplugin.guarded
def main():
"""
Handle command line parameters and initiate the check.
"""
import argparse
parser = argparse.ArgumentParser(description="Check XMPP services")
parser.add_argument(
"-H", "--host-address", help="host address", required=True)
parser.add_argument(
"-p", "--port", help="port", type=int)
is_server = parser.add_mutually_exclusive_group()
is_server.add_argument(
"--s2s", dest="is_server", action='store_true',
help="server to server (s2s)")
is_server.add_argument(
"--c2s", dest="is_server", action='store_false',
help="client to server (c2s)")
ipv6 = parser.add_mutually_exclusive_group()
ipv6.add_argument(
"-4", "--ipv4", dest="ipv6", action='store_false',
help="enforce IPv4")
ipv6.add_argument(
"-6", "--ipv6", dest="ipv6", action='store_true',
help="enforce IPv6")
parser.add_argument(
"--servername", help="server name to be used")
parser.add_argument(
"--starttls",
action='store_true', help="check whether the service allows starttls")
parser.add_argument(
"-w", "--warning", metavar="SECONDS", default='',
help="return warning if connection setup takes longer than SECONDS")
parser.add_argument(
"-c", "--critical", metavar="SECONDS", default='',
help="return critical if connection setup takes longer than SECONDS")
parser.add_argument(
"--no-check-certificates", dest='checkcerts', action='store_false',
help="do not check whether the XMPP server's certificate is valid")
parser.add_argument(
"-r", "--ca-roots", dest="caroots",
help="path to a file or directory where CA certifcates can be found")
parser.add_argument(
"--warn-days", dest="warndays", type=int, default=0,
help=(
"set state to WARN if the certificate is valid for not more than "
"the given number of days"))
parser.add_argument(
"--crit-days", dest="critdays", type=int, default=0,
help=(
"set state to CRITICAL if the certificate is valid for not more "
"than the given number of days"))
parser.add_argument(
'-v', '--verbose', action='count', default=0)
parser.set_defaults(is_server=False, ipv6=None, checkcerts=True)
args = parser.parse_args()
if args.port is None:
if args.is_server:
args.port = 5269
else:
args.port = 5222
if args.servername is None:
args.servername = args.host_address
kwargs = vars(args)
warning, critical, warndays, critdays, verbose = [
kwargs.pop(arg) for arg in
('warning', 'critical', 'warndays', 'critdays', 'verbose')
]
check = nagiosplugin.Check(
Xmpp(**kwargs),
XmppContext(
'time', warning, critical, fmt_metric="request took {value}{uom}"),
DaysValidContext('daysleft', warndays, critdays),
XmppSummary(),
)
check.main(verbose=verbose, timeout=0)
if __name__ == "__main__":
main()