def __enter__(self):
if os.getuid() != 0:
if (self._uname
and self._uname != pwd.getpwnam(self._uname).pw_name
or self._gname
and self._gname != grp.getgrnam(self._gname).gr_name):
raise error.SnmpResponderError(
'Process is running under different UID/GID')
else:
return
else:
if not self._uname or not self._gname:
raise error.SnmpResponderError(
'Must drop privileges to a non-privileged user&group')
try:
runningUid = pwd.getpwnam(self._uname).pw_uid
runningGid = grp.getgrnam(self._gname).gr_gid
except Exception:
raise error.SnmpResponderError(
'getpwnam()/getgrnam() failed for %s/%s: %s' %
(self._uname, self._gname, sys.exc_info()[1]))
try:
os.setgroups([])
except Exception:
raise error.SnmpResponderError('setgroups() failed: %s' %
sys.exc_info()[1])
try:
if self._final:
os.setgid(runningGid)
os.setuid(runningUid)
else:
self._olduid = os.getuid()
self._oldgid = os.getgid()
os.setegid(runningGid)
os.seteuid(runningUid)
except Exception:
raise error.SnmpResponderError(
'%s failed for %s/%s: %s' %
(self._final and 'setgid()/setuid()'
or 'setegid()/seteuid()', runningGid, runningUid,
sys.exc_info()[1]))
os.umask(63) # 0077
def __exit__(self, *args):
if self._olduid is None or self._oldgid is None:
return
try:
os.setegid(self._oldgid)
os.seteuid(self._olduid)
except Exception:
raise error.SnmpResponderError(
'setegid()/seteuid() failed for %s/%s: %s' %
(self._oldgid, self._olduid, sys.exc_info()[1]))
def getAttrValue(self, attr, *nodes, **kwargs):
scope = nodes
while scope:
obj = self.traverse([self.objects], scope)
if obj and attr in obj:
expect = kwargs.get('expect')
if 'vector' in kwargs:
if expect:
try:
return [expect(x) for x in obj[attr]]
except Exception:
raise error.SnmpResponderError(
'%s value casting error at scope "%s" attribute "%s"'
% (self, '.'.join(nodes), attr))
else:
return obj[attr]
else:
if obj[attr]:
if expect:
try:
return expect(obj[attr][0])
except Exception:
raise error.SnmpResponderError(
'%s value casting error at scope "%s" attribute "%s"'
% (self, '.'.join(nodes), attr))
else:
return obj[attr][0]
else:
return ''
scope = scope[:-1]
if 'default' in kwargs:
return kwargs['default']
else:
raise error.SnmpResponderError(
'%s non-existing attribute "%s" at scope "%s"' %
(self, attr, '.'.join(nodes)))
def load(self, filename):
try:
self.lines = open(filename).readlines()
except OSError:
raise error.SnmpResponderError('cant open config file %s: %s' %
(filename, sys.exc_info()[1]))
self.tokens = []
while self.lines:
line = self.lines.pop(0)
if line and line[0] == '#':
continue
tokens = re.findall(r'(?:[^\s,"]|"(?:\\.|[^"])*")+', line)
for i in range(len(tokens)):
if tokens[i] and tokens[i][0] == '"' and tokens[i][-1] == '"':
tokens[i] = tokens[i][1:-1]
if not tokens or not tokens[0] or tokens[0][0] == '#':
continue
for token in tokens:
# Figure out the grammar type of the token
if token and token[-1] == SYMBOL_OPTION:
# It's an option
symbol = SYMBOL_OPTION
# Cut the trailing char from token
token = token[:-1]
elif token == '{':
symbol = SYMBOL_SECTION_BEGIN
elif token == '}':
symbol = SYMBOL_SECTION_END
else:
symbol = SYMBOL_WORD
# Attach read tokens to list of tokens
self.tokens.append((token, symbol))
self.index = 0
self.length = len(self.tokens)
return self
def loadPlugin(self, pluginId, pluginModuleName, pluginOptions):
if pluginId in self.__plugins:
raise error.SnmpResponderError('duplicate plugin ID %s' % pluginId)
for pluginModulesDir in self.__path:
log.info('scanning "%s" directory for plugin modules...' %
pluginModulesDir)
if not os.path.exists(pluginModulesDir):
log.error('directory "%s" does not exist' % pluginModulesDir)
continue
modPath = os.path.join(pluginModulesDir, pluginModuleName + '.py')
if not os.path.exists(modPath):
log.error('Variation module "%s" not found' % modPath)
continue
ctx = {
'modulePath': modPath,
'moduleContext': {},
'moduleOptions': pluginOptions
}
modData = open(modPath).read()
try:
exec(compile(modData, modPath, 'exec'), ctx)
except Exception:
raise error.SnmpResponderError(
'plugin module "%s" execution failure: %s' %
(modPath, sys.exc_info()[1]))
else:
pluginModule = ctx
try:
if self.__progId not in pluginModule['hostProgs']:
log.error(
'ignoring plugin module "%s" (unmatched program ID)'
% modPath)
continue
if self.__apiVer not in pluginModule['apiVersions']:
log.error(
'ignoring plugin module "%s" (incompatible API version)'
% modPath)
continue
except KeyError:
log.error(
'ignoring plugin module "%s" (missing versioning info)'
% modPath)
continue
self.__plugins[pluginId] = pluginModule
log.info('plugin module "%s" loaded' % modPath)
break
else:
raise error.SnmpResponderError(
'plugin module "%s" not found in search path(s): %s' %
(pluginModuleName, ', '.join(self.__path)))
def daemonize(pidfile):
try:
pid = os.fork()
if pid > 0:
# exit first parent
os._exit(0)
except OSError:
raise error.SnmpResponderError('ERROR: fork #1 failed: %s' %
sys.exc_info()[1])
# decouple from parent environment
try:
os.chdir('/')
os.setsid()
except OSError:
pass
os.umask(0)
# do second fork
try:
pid = os.fork()
if pid > 0:
# exit from second parent
os._exit(0)
except OSError:
raise error.SnmpResponderError('ERROR: fork #2 failed: %s' %
sys.exc_info()[1])
def signal_cb(s, f):
raise KeyboardInterrupt
for s in signal.SIGTERM, signal.SIGINT, signal.SIGHUP, signal.SIGQUIT:
signal.signal(s, signal_cb)
# write pidfile
def atexit_cb():
try:
if pidfile:
os.remove(pidfile)
except OSError:
pass
atexit.register(atexit_cb)
try:
if pidfile:
fd, nm = tempfile.mkstemp(dir=os.path.dirname(pidfile))
os.write(fd, ('%d\n' % os.getpid()).encode('utf-8'))
os.close(fd)
os.rename(nm, pidfile)
except Exception:
raise error.SnmpResponderError('Failed to create PID file %s: %s' %
(pidfile, sys.exc_info()[1]))
# redirect standard file descriptors
sys.stdout.flush()
sys.stderr.flush()
si = open(os.devnull, 'r')
so = open(os.devnull, 'a+')
se = open(os.devnull, 'a+')
os.dup2(si.fileno(), sys.stdin.fileno())
os.dup2(so.fileno(), sys.stdout.fileno())
os.dup2(se.fileno(), sys.stderr.fileno())
def daemonize(pidfile):
raise error.SnmpResponderError(
'Windows is not inhabited with daemons!')
def load_section(self):
obj = {'_name': '', '_children': []}
state = 'FSM_START'
while 1:
# Initial state
if state == 'FSM_START':
try:
token, symbol = self.scanner.get_token()
except error.EofError:
state = 'FSM_STOP'
continue
self.scanner.unget_token()
# See if it's object closure sign
if symbol == SYMBOL_SECTION_END:
state = 'FSM_SECTION_END'
# See if it's symbol sign
elif symbol == SYMBOL_OPTION:
state = 'FSM_OPTION_NAME'
# Default is to start from parsing up new section
else:
state = 'FSM_SECTION_NAME'
# If object name expected
elif state == 'FSM_SECTION_NAME':
self.scanner.get_token()
self.scanner.unget_token()
# Move to next FSM state
state = 'FSM_SECTION_BEGIN'
# If object body delimiter expected
elif state == 'FSM_SECTION_BEGIN':
self.scanner.get_token()
# Get section begin
token, symbol = self.scanner.get_token()
# Now unget these tokens to be used at the
# next FSM state
self.scanner.unget_token()
self.scanner.unget_token()
# Make sure it's object's body start sign
if symbol != SYMBOL_SECTION_BEGIN:
raise error.SnmpResponderError(
'%s missing object beginning sign: %s' % (self, token))
state = 'FSM_CHILD_BEGIN'
# If inclusive object expected
elif state == 'FSM_CHILD_BEGIN':
name, symbol = self.scanner.get_token()
self.scanner.get_token()
child_object = self.load_section()
child_object['_name'] = name
# Attach child object to the list of enclosed objects
obj['_children'].append(child_object)
state = 'FSM_CHILD_END'
# If object body closure delimiter expected
elif state == 'FSM_CHILD_END':
# Get next token
token, symbol = self.scanner.get_token()
# Make sure it's object's body end sign
if symbol != SYMBOL_SECTION_END:
raise error.SnmpResponderError(
'%s missing object closure sign: %s' % (self, token))
# Move to the beginning of FSM
state = 'FSM_START'
# If object body closure delimiter expected
elif state == 'FSM_SECTION_END':
# Get next token
token, symbol = self.scanner.get_token()
# Now unget token to be used at upper level FSM instance
self.scanner.unget_token()
# Make sure it's object's body end sign
if symbol != SYMBOL_SECTION_END:
raise error.SnmpResponderError(
'%s missing object closure sign: %s' % (self, token))
# Move to next FSM state
state = 'FSM_STOP'
# If attribute name expected
elif state == 'FSM_OPTION_NAME':
# Get next token
token, symbol = self.scanner.get_token()
# See if this attribute does not yet exist
if token in obj:
raise error.SnmpResponderError(
'%s multiple option occurrence: %s' % (self, token))
# Accept token as attribute name
obj[token] = []
# Now unget token to be used at the next FSM state
self.scanner.unget_token()
# Move to next FSM state
state = 'FSM_OPTION_VALUE'
# If option value expected
elif state == 'FSM_OPTION_VALUE':
option, symbol = self.scanner.get_token()
# Read up one or more option values
while 1:
try:
token, symbol = self.scanner.get_token()
except error.EofError:
state = 'FSM_STOP'
break
# If it's not a plain word
if symbol != SYMBOL_WORD:
self.scanner.unget_token()
# See if it's object begin symbol
if symbol == SYMBOL_SECTION_BEGIN:
# Unget section begin sign
self.scanner.unget_token()
# Remove previously added last value of
# the list as it turned to be section name
del obj[option][-1]
# Move to the beginning of FSM
state = 'FSM_START'
break
# Accept token as attribute value
if token.lower()[:2] == '0x':
token = str(OctetString(hexValue=token[2:]))
obj[option].append(token)
# If FSM is gonna stop
elif state == 'FSM_STOP':
# Return object loaded
return obj
# If this FSM state is not known
else:
raise error.SnmpResponderError('%s unknown FSM state: %s' %
(self, state))
def unget_token(self):
if not self.index:
raise error.SnmpResponderError('%s nothing to unget' % self)
self.index -= 1
def parse(self):
try:
return self.load_section()
except error.EofError:
raise error.SnmpResponderError(
'%s premature EOF while reading config file' % self)