def resolve_vars(cls, vars):
"""
Resolve FM key -> value dict according to MIBs
:param cls:
:param vars:
:return:
"""
r = {}
for k in vars:
if not is_oid(k):
# Nothing to resolve
continue
v = fm_unescape(vars[k])
rk, syntax = cls.get_name_and_syntax(k)
rv = v
if syntax:
# Format value according to syntax
if syntax["base_type"] == "Enumeration":
# Expand enumerated type
try:
rv = syntax["enum_map"][str(v)]
except KeyError:
pass
elif syntax["base_type"] == "Bits":
# @todo: Fix ugly hack
if v.startswith("="):
xv = int(v[1:], 16)
else:
xv = 0
for c in v:
xv = (xv << 8) + ord(c)
# Decode
b_map = syntax.get("enum_map", {})
b = []
n = 0
while xv:
if xv & 1:
x = str(n)
if x in b_map:
b = [b_map[x]] + b
else:
b = ["%X" % (1 << n)]
n += 1
xv >>= 1
rv = "(%s)" % ",".join(b)
else:
# Render according to TC
rv = render_tc(v, syntax["base_type"],
syntax.get("display_hint", None))
try:
unicode(rv, "utf8")
except ValueError:
# Escape invalid UTF8
rv = fm_escape(rv)
else:
try:
unicode(rv, "utf8")
except ValueError:
# escape invalid UTF8
rv = fm_escape(rv)
if is_oid(v):
# Resolve OID in value
rv = MIB.get_name(v)
if rk != k or rv != v:
r[rk] = rv
return r
def classify_event(self, event, data):
"""
Perform event classification.
Classification steps are:
1. Format SNMP values accordind to MIB definitions (for SNMP events only)
2. Find matching classification rule
3. Calculate rule variables
:param event: Event to classify
:type event: NewEvent
:returns: Classification status (CR_*)
"""
metrics[E_SRC_METRICS.get(event.source, E_SRC_OTHER)] += 1
is_unknown = False
#
pre_event = data.pop("$event", None)
# Resolve MIB variables for SNMP Traps
resolved_vars = {"profile": event.managed_object.profile.name}
# Store event variables
event.raw_vars = data
if event.source == E_SRC_SNMP_TRAP:
resolved_vars.update(MIB.resolve_vars(event.raw_vars))
event.resolved_vars = resolved_vars
# Get matched event class
if pre_event:
# Event is preprocessed, get class and variables
event_class_name = pre_event.get("class")
event_class = EventClass.get_by_name(event_class_name)
if not event_class:
self.logger.error(
"[%s|%s|%s] Failed to process event: Invalid event class '%s'",
event.id, event.managed_object.name, event.managed_object,
event_class_name)
metrics[CR_FAILED] += 1
return # Drop malformed message
event.event_class = event_class
event.vars = pre_event.get("vars", {})
else:
# Prevent unclassified events flood
if self.check_unclassified_syslog_flood(event):
return
# Find matched event class
c_vars = event.raw_vars.copy()
c_vars.update(
dict(
(k, fm_unescape(resolved_vars[k])) for k in resolved_vars))
rule, vars = self.ruleset.find_rule(event, c_vars)
if rule is None:
# Something goes wrong.
# No default rule found. Exit immediately
self.logger.error("No default rule found. Exiting")
os._exit(1)
if rule.to_drop:
# Silently drop event if declared by action
self.logger.info("[%s|%s|%s] Dropped by action", event.id,
event.managed_object.name,
event.managed_object.address)
metrics[CR_DELETED] += 1
return
if rule.is_unknown_syslog:
# Append to codebook
msg = event.raw_vars.get("message", "")
cb = self.get_msg_codebook(msg)
o_id = event.managed_object.id
if o_id not in self.unclassified_codebook:
self.unclassified_codebook[o_id] = []
cbs = [cb] + self.unclassified_codebook[o_id]
cbs = cbs[:self.unclassified_codebook_depth]
self.unclassified_codebook[o_id] = cbs
self.logger.debug("[%s|%s|%s] Matching rule: %s", event.id,
event.managed_object.name,
event.managed_object.address, rule.name)
event.event_class = rule.event_class
# Calculate rule variables
event.vars = self.ruleset.eval_vars(event, event.event_class, vars)
message = "Classified as '%s' by rule '%s'" % (
event.event_class.name, rule.name)
event.log += [
EventLog(timestamp=datetime.datetime.now(),
from_status="N",
to_status="A",
message=message)
]
is_unknown = rule.is_unknown
# Event class found, process according to rules
self.logger.info("[%s|%s|%s] Event class: %s (%s)", event.id,
event.managed_object.name,
event.managed_object.address, event.event_class.name,
event.vars)
# Additionally check link events
if self.check_link_event(event):
return
# Deduplication
if self.deduplicate_event(event):
return
# Suppress repeats
if self.suppress_repeats(event):
return
# Activate event
event.expires = event.timestamp + datetime.timedelta(
seconds=event.event_class.ttl)
event.save()
# Call handlers
if self.call_event_handlers(event):
return
# Call triggers
if self.call_event_triggers(event):
return
# Finally dispose event to further processing by correlator
if event.to_dispose:
self.dispose_event(event)
if is_unknown:
metrics[CR_UNKNOWN] += 1
elif pre_event:
metrics[CR_PREPROCESSED] += 1
else:
metrics[CR_CLASSIFIED] += 1
def test_fm_unescape(value, expected):
assert fm_unescape(value) == expected