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# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: t -*-
# vi: set ft=python sts=4 ts=4 sw=4 noet :
# This file is part of Fail2Ban.
#
# Fail2Ban 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.
#
# Fail2Ban 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 Fail2Ban; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
__author__ = "Cyril Jaquier, Arturo 'Buanzo' Busleiman, Yaroslav Halchenko"
__license__ = "GPL"
import gc
import locale
import logging
import os
import re
import sys
import traceback
from threading import Lock
from .server.mytime import MyTime
import imp
try:
import ctypes
_libcap = ctypes.CDLL('libcap.so.2')
except:
_libcap = None
PREFER_ENC = locale.getpreferredencoding()
# correct preferred encoding if lang not set in environment:
if PREFER_ENC.startswith('ANSI_'): # pragma: no cover
if sys.stdout and sys.stdout.encoding is not None and not sys.stdout.encoding.startswith('ANSI_'):
PREFER_ENC = sys.stdout.encoding
elif all((os.getenv(v) in (None, "") for v in ('LANGUAGE', 'LC_ALL', 'LC_CTYPE', 'LANG'))):
PREFER_ENC = 'UTF-8';
# py-2.x: try to minimize influence of sporadic conversion errors on python 2.x,
# caused by implicit converting of string/unicode (e. g. `str(u"\uFFFD")` produces an error
# if default encoding is 'ascii');
if sys.version_info < (3,): # pragma: 3.x no cover
# correct default (global system) encoding (mostly UTF-8):
def __resetDefaultEncoding(encoding):
global PREFER_ENC
ode = sys.getdefaultencoding().upper()
if ode == 'ASCII' and ode != PREFER_ENC.upper():
# setdefaultencoding is normally deleted after site initialized, so hack-in using load of sys-module:
_sys = sys
if not hasattr(_sys, "setdefaultencoding"):
try:
from imp import load_dynamic as __ldm
_sys = __ldm('_sys', 'sys')
except ImportError: # pragma: no cover - only if load_dynamic fails
imp.reload(sys)
_sys = sys
if hasattr(_sys, "setdefaultencoding"):
_sys.setdefaultencoding(encoding)
# override to PREFER_ENC:
__resetDefaultEncoding(PREFER_ENC)
del __resetDefaultEncoding
# todo: rewrite explicit (and implicit) str-conversions via encode/decode with IO-encoding (sys.stdout.encoding),
# e. g. inside tags-replacement by command-actions, etc.
#
# Following "uni_decode", "uni_string" functions unified python independent any
# to string converting.
#
# Typical example resp. work-case for understanding the coding/decoding issues:
#
# [isinstance('', str), isinstance(b'', str), isinstance(u'', str)]
# [True, True, False]; # -- python2
# [True, False, True]; # -- python3
#
if sys.version_info >= (3,): # pragma: 2.x no cover
def uni_decode(x, enc=PREFER_ENC, errors='strict'):
try:
if isinstance(x, bytes):
return x.decode(enc, errors)
return x
except (UnicodeDecodeError, UnicodeEncodeError): # pragma: no cover - unsure if reachable
if errors != 'strict':
raise
return x.decode(enc, 'replace')
def uni_string(x):
if not isinstance(x, bytes):
return str(x)
return x.decode(PREFER_ENC, 'replace')
else: # pragma: 3.x no cover
def uni_decode(x, enc=PREFER_ENC, errors='strict'):
try:
if isinstance(x, str):
return x.encode(enc, errors)
return x
except (UnicodeDecodeError, UnicodeEncodeError): # pragma: no cover - unsure if reachable
if errors != 'strict':
raise
return x.encode(enc, 'replace')
if sys.getdefaultencoding().upper() != 'UTF-8': # pragma: no cover - utf-8 is default encoding now
def uni_string(x):
if not isinstance(x, str):
return str(x)
return x.encode(PREFER_ENC, 'replace')
else:
uni_string = str
def _as_bool(val):
return bool(val) if not isinstance(val, str) \
else val.lower() in ('1', 'on', 'true', 'yes')
def formatExceptionInfo():
""" Consistently format exception information """
cla, exc = sys.exc_info()[:2]
return (cla.__name__, uni_string(exc))
#
# Following "traceback" functions are adopted from PyMVPA distributed
# under MIT/Expat and copyright by PyMVPA developers (i.e. me and
# Michael). Hereby I re-license derivative work on these pieces under GPL
# to stay in line with the main Fail2Ban license
#
def mbasename(s):
"""Custom function to include directory name if filename is too common
Also strip .py at the end
"""
base = os.path.basename(s)
if base.endswith('.py'):
base = base[:-3]
if base in set(['base', '__init__']):
base = os.path.basename(os.path.dirname(s)) + '.' + base
return base
class TraceBack(object):
"""Customized traceback to be included in debug messages
"""
def __init__(self, compress=False):
"""Initialize TrackBack metric
Parameters
----------
compress : bool
if True then prefix common with previous invocation gets
replaced with ...
"""
self.__prev = ""
self.__compress = compress
def __call__(self):
ftb = traceback.extract_stack(limit=100)[:-2]
entries = [
[mbasename(x[0]), os.path.dirname(x[0]), str(x[1])] for x in ftb]
entries = [ [e[0], e[2]] for e in entries
if not (e[0] in ['unittest', 'logging.__init__']
or e[1].endswith('/unittest'))]
# lets make it more concise
entries_out = [entries[0]]
for entry in entries[1:]:
if entry[0] == entries_out[-1][0]:
entries_out[-1][1] += ',%s' % entry[1]
else:
entries_out.append(entry)
sftb = '>'.join(['%s:%s' % (mbasename(x[0]),
x[1]) for x in entries_out])
if self.__compress:
# lets remove part which is common with previous invocation
prev_next = sftb
common_prefix = os.path.commonprefix((self.__prev, sftb))
common_prefix2 = re.sub('>[^>]*$', '', common_prefix)
if common_prefix2 != "":
sftb = '...' + sftb[len(common_prefix2):]
self.__prev = prev_next
return sftb
class FormatterWithTraceBack(logging.Formatter):
"""Custom formatter which expands %(tb) and %(tbc) with tracebacks
TODO: might need locking in case of compressed tracebacks
"""
def __init__(self, fmt, *args, **kwargs):
logging.Formatter.__init__(self, fmt=fmt, *args, **kwargs)
compress = '%(tbc)s' in fmt
self._tb = TraceBack(compress=compress)
def format(self, record):
record.tbc = record.tb = self._tb()
return logging.Formatter.format(self, record)
logging.exitOnIOError = False
def __stopOnIOError(logSys=None, logHndlr=None): # pragma: no cover
if logSys and len(logSys.handlers):
logSys.removeHandler(logSys.handlers[0])
if logHndlr:
logHndlr.close = lambda: None
logging.StreamHandler.flush = lambda self: None
#sys.excepthook = lambda *args: None
if logging.exitOnIOError:
try:
sys.stderr.close()
except:
pass
sys.exit(0)
try:
BrokenPipeError = BrokenPipeError
except NameError: # pragma: 3.x no cover
BrokenPipeError = IOError
__origLog = logging.Logger._log
def __safeLog(self, level, msg, args, **kwargs):
"""Safe log inject to avoid possible errors by unsafe log-handlers,
concat, str. conversion, representation fails, etc.
Used to intrude exception-safe _log-method instead of _log-method
of Logger class to be always safe by logging and to get more-info about.
See testSafeLogging test-case for more information. At least the errors
covered in phase 3 seems to affected in all known pypy/python versions
until now.
"""
try:
# if isEnabledFor(level) already called...
__origLog(self, level, msg, args, **kwargs)
except (BrokenPipeError, IOError) as e: # pragma: no cover
if e.errno == 32: # closed / broken pipe
__stopOnIOError(self)
raise
except Exception as e: # pragma: no cover - unreachable if log-handler safe in this python-version
try:
for args in (
("logging failed: %r on %s", (e, uni_string(msg))),
(" args: %r", ([uni_string(a) for a in args],))
):
try:
__origLog(self, level, *args)
except: # pragma: no cover
pass
except: # pragma: no cover
pass
logging.Logger._log = __safeLog
__origLogFlush = logging.StreamHandler.flush
def __safeLogFlush(self):
"""Safe flush inject stopping endless logging on closed streams (redirected pipe).
"""
try:
__origLogFlush(self)
except (BrokenPipeError, IOError) as e: # pragma: no cover
if e.errno == 32: # closed / broken pipe
__stopOnIOError(None, self)
raise
logging.StreamHandler.flush = __safeLogFlush
def getLogger(name):
"""Get logging.Logger instance with Fail2Ban logger name convention
"""
if "." in name:
name = "fail2ban.%s" % name.rpartition(".")[-1]
return logging.getLogger(name)
def str2LogLevel(value):
try:
if isinstance(value, int) or value.isdigit():
ll = int(value)
else:
ll = getattr(logging, value.upper())
except AttributeError:
raise ValueError("Invalid log level %r" % value)
return ll
def getVerbosityFormat(verbosity, fmt=' %(message)s', addtime=True, padding=True):
"""Custom log format for the verbose runs
"""
if verbosity > 1: # pragma: no cover
if verbosity > 3:
fmt = ' | %(module)15.15s-%(levelno)-2d: %(funcName)-20.20s |' + fmt
if verbosity > 2:
fmt = ' +%(relativeCreated)5d %(thread)X %(name)-25.25s %(levelname)-5.5s' + fmt
else:
fmt = ' %(thread)X %(levelname)-5.5s' + fmt
if addtime:
fmt = ' %(asctime)-15s' + fmt
else: # default (not verbose):
fmt = "%(name)-24s[%(process)d]: %(levelname)-7s" + fmt
if addtime:
fmt = "%(asctime)s " + fmt
# remove padding if not needed:
if not padding:
fmt = re.sub(r'(?<=\))-?\d+(?:\.\d+)?s', lambda m: 's', fmt)
return fmt
def excepthook(exctype, value, traceback):
"""Except hook used to log unhandled exceptions to Fail2Ban log
"""
getLogger("fail2ban").critical(
"Unhandled exception in Fail2Ban:", exc_info=True)
return sys.__excepthook__(exctype, value, traceback)
def splitwords(s):
"""Helper to split words on any comma, space, or a new line
Returns empty list if input is empty (or None) and filters
out empty entries
"""
if not s:
return []
return list(filter(bool, [v.strip() for v in re.split('[ ,\n]+', s)]))
if sys.version_info >= (3,5):
eval(compile(r'''if 1:
def _merge_dicts(x, y):
"""Helper to merge dicts.
"""
if y:
return {**x, **y}
return x
def _merge_copy_dicts(x, y):
"""Helper to merge dicts to guarantee a copy result (r is never x).
"""
return {**x, **y}
''', __file__, 'exec'))
else:
def _merge_dicts(x, y):
"""Helper to merge dicts.
"""
r = x
if y:
r = x.copy()
r.update(y)
return r
def _merge_copy_dicts(x, y):
"""Helper to merge dicts to guarantee a copy result (r is never x).
"""
r = x.copy()
if y:
r.update(y)
return r
#
# Following function used for parse options from parameter (e.g. `name[p1=0, p2="..."][p3='...']`).
#
# regex, to extract list of options:
OPTION_CRE = re.compile(r"^([^\[]+)(?:\[(.*)\])?\s*$", re.DOTALL)
# regex, to iterate over single option in option list, syntax:
# `action = act[p1="...", p2='...', p3=...]`, where the p3=... not contains `,` or ']'
# since v0.10 separator extended with `]\s*[` for support of multiple option groups, syntax
# `action = act[p1=...][p2=...]`
OPTION_EXTRACT_CRE = re.compile(
r'\s*([\w\-_\.]+)=(?:"([^"]*)"|\'([^\']*)\'|([^,\]]*))(?:,|\]\s*\[|$|(?P<wrngA>.+))|,?\s*$|(?P<wrngB>.+)', re.DOTALL)
# split by new-line considering possible new-lines within options [...]:
OPTION_SPLIT_CRE = re.compile(
r'(?:[^\[\s]+(?:\s*\[\s*(?:[\w\-_\.]+=(?:"[^"]*"|\'[^\']*\'|[^,\]]*)\s*(?:,|\]\s*\[)?\s*)*\])?\s*|\S+)(?=\n\s*|\s+|$)', re.DOTALL)
def extractOptions(option):
match = OPTION_CRE.match(option)
if not match:
raise ValueError("unexpected option syntax")
option_name, optstr = match.groups()
option_opts = dict()
if optstr:
for optmatch in OPTION_EXTRACT_CRE.finditer(optstr):
if optmatch.group("wrngA"):
raise ValueError("unexpected syntax at %d after option %r: %s" % (
optmatch.start("wrngA"), optmatch.group(1), optmatch.group("wrngA")[0:25]))
if optmatch.group("wrngB"):
raise ValueError("expected option, wrong syntax at %d: %s" % (
optmatch.start("wrngB"), optmatch.group("wrngB")[0:25]))
opt = optmatch.group(1)
if not opt: continue
value = [
val for val in optmatch.group(2,3,4) if val is not None][0]
option_opts[opt.strip()] = value.strip()
return option_name, option_opts
def splitWithOptions(option):
return OPTION_SPLIT_CRE.findall(option)
#
# Following facilities used for safe recursive interpolation of
# tags (<tag>) in tagged options.
#
# max tag replacement count (considering tag X in tag Y repeat):
MAX_TAG_REPLACE_COUNT = 25
# compiled RE for tag name (replacement name)
TAG_CRE = re.compile(r'<([^ <>]+)>')
def substituteRecursiveTags(inptags, conditional='',
ignore=(), addrepl=None
):
"""Sort out tag definitions within other tags.
Since v.0.9.2 supports embedded interpolation (see test cases for examples).
so: becomes:
a = 3 a = 3
b = <a>_3 b = 3_3
Parameters
----------
inptags : dict
Dictionary of tags(keys) and their values.
Returns
-------
dict
Dictionary of tags(keys) and their values, with tags
within the values recursively replaced.
"""
#logSys = getLogger("fail2ban")
tre_search = TAG_CRE.search
tags = inptags
# init:
ignore = set(ignore)
done = set()
noRecRepl = hasattr(tags, "getRawItem")
# repeat substitution while embedded-recursive (repFlag is True)
repCounts = {}
while True:
repFlag = False
# substitute each value:
for tag in tags.keys():
# ignore escaped or already done (or in ignore list):
if tag in ignore or tag in done: continue
# ignore replacing callable items from calling map - should be converted on demand only (by get):
if noRecRepl and callable(tags.getRawItem(tag)): continue
value = orgval = uni_string(tags[tag])
# search and replace all tags within value, that can be interpolated using other tags:
m = tre_search(value)
rplc = repCounts.get(tag, {})
#logSys.log(5, 'TAG: %s, value: %s' % (tag, value))
while m:
# found replacement tag:
rtag = m.group(1)
# don't replace tags that should be currently ignored (pre-replacement):
if rtag in ignore:
m = tre_search(value, m.end())
continue
#logSys.log(5, 'found: %s' % rtag)
if rtag == tag or rplc.get(rtag, 1) > MAX_TAG_REPLACE_COUNT:
# recursive definitions are bad
#logSys.log(5, 'recursion fail tag: %s value: %s' % (tag, value) )
raise ValueError(
"properties contain self referencing definitions "
"and cannot be resolved, fail tag: %s, found: %s in %s, value: %s" %
(tag, rtag, rplc, value))
repl = None
if conditional:
repl = tags.get(rtag + '?' + conditional)
if repl is None:
repl = tags.get(rtag)
# try to find tag using additional replacement (callable):
if repl is None and addrepl is not None:
repl = addrepl(rtag)
if repl is None:
# Missing tags - just continue on searching after end of match
# Missing tags are ok - cInfo can contain aInfo elements like <HOST> and valid shell
# constructs like <STDIN>.
m = tre_search(value, m.end())
continue
# if calling map - be sure we've string:
if not isinstance(repl, str): repl = uni_string(repl)
value = value.replace('<%s>' % rtag, repl)
#logSys.log(5, 'value now: %s' % value)
# increment reference count:
rplc[rtag] = rplc.get(rtag, 0) + 1
# the next match for replace:
m = tre_search(value, m.start())
#logSys.log(5, 'TAG: %s, newvalue: %s' % (tag, value))
# was substituted?
if orgval != value:
# check still contains any tag - should be repeated (possible embedded-recursive substitution):
if tre_search(value):
repCounts[tag] = rplc
repFlag = True
# copy return tags dict to prevent modifying of inptags:
if id(tags) == id(inptags):
tags = inptags.copy()
tags[tag] = value
# no more sub tags (and no possible composite), add this tag to done set (just to be faster):
if '<' not in value: done.add(tag)
# stop interpolation, if no replacements anymore:
if not repFlag:
break
return tags
if _libcap:
def prctl_set_th_name(name):
"""Helper to set real thread name (used for identification and diagnostic purposes).
Side effect: name can be silently truncated to 15 bytes (16 bytes with NTS zero)
"""
try:
if sys.version_info >= (3,): # pragma: 2.x no cover
name = name.encode()
else: # pragma: 3.x no cover
name = bytes(name)
_libcap.prctl(15, name) # PR_SET_NAME = 15
except: # pragma: no cover
pass
else: # pragma: no cover
def prctl_set_th_name(name):
pass
class BgService(object):
"""Background servicing
Prevents memory leak on some platforms/python versions,
using forced GC in periodical intervals.
"""
_mutex = Lock()
_instance = None
def __new__(cls):
if not cls._instance:
cls._instance = \
super(BgService, cls).__new__(cls)
return cls._instance
def __init__(self):
self.__serviceTime = -0x7fffffff
self.__periodTime = 30
self.__threshold = 100;
self.__count = self.__threshold;
if hasattr(gc, 'set_threshold'):
gc.set_threshold(0)
# don't disable auto garbage, because of non-reference-counting python's (like pypy),
# otherwise it may leak there on objects like unix-socket, etc.
#gc.disable()
def service(self, force=False, wait=False):
self.__count -= 1
# avoid locking if next service time don't reached
if not force and (self.__count > 0 or MyTime.time() < self.__serviceTime):
return False
# return immediately if mutex already locked (other thread in servicing):
if not BgService._mutex.acquire(wait):
return False
try:
# check again in lock:
if MyTime.time() < self.__serviceTime:
return False
gc.collect()
self.__serviceTime = MyTime.time() + self.__periodTime
self.__count = self.__threshold
return True
finally:
BgService._mutex.release()
return False
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