This change allows a weird sampling rate of 0, which completely suppresses
all notifications (previously this crashed Bro). If also fixes the sampling
threshold to work with sampling rates of 0.
The generation of weird events, by default, are now rate-limited
according to these tunable options:
- Weird::sampling_whitelist
- Weird::sampling_threshold
- Weird::sampling_rate
- Weird::sampling_duration
The new get_reporter_stats() BIF also allows one to query the
total number of weirds generated (pre-sampling) which the new
policy/misc/weird-stats.bro script uses periodically to populate
a weird_stats.log.
There's also new reporter BIFs to allow generating weirds from the
script-layer such that they go through the same, internal
rate-limiting/sampling mechanisms:
- Reporter::conn_weird
- Reporter::flow_weird
- Reporter::net_weird
Some of the code was adapted from previous work by Johanna Amann.
The hook being added is:
bool HookReporter(const std::string& prefix, const EventHandlerPtr event,
const Connection* conn, const val_list* addl, bool location,
const Location* location1, const Location* location2,
bool time, const std::string& buffer) override;
This hook gives access to basically all information that is available in
the function in Reporter.cc that performs the logging. The hook is
called each time when anything passes through the reporter in the cases
in which an event usually would be called. This includes weirds. The
hook can return false to prevent the normal reporter events from being
raised.
This change introduces error events for Table and Event readers. Users
can now specify an event that is called when an info, warning, or error
is emitted by their input reader. This can, e.g., be used to raise
notices in case errors occur when reading an important input stream.
Example:
event error_event(desc: Input::TableDescription, msg: string, level: Reporter::Level)
{
...
}
event bro_init()
{
Input::add_table([$source="a", $error_ev=error_event, ...]);
}
For the moment, this converts all errors in the Asciiformatter into
warnings (to show that they are non-fatal) - the Reader itself also has
to throw an Error to show that a fatal error occurred and processing
will be abort.
It might be nicer to change this and require readers to mark fatal
errors as such when throwing them.
Addresses BIT-1181
This issue is especially helpful in the case of the Val::CONVERTER error and having:
"fatal error in <no location>: Val::CONVERTER ..."
Nebulous error and sans location, it is extremely hard to figure out the culprit. Thus, if Bro is built DEBUG, fatal should provide a core.
This subtle change prevents having to change FatalErrors to FatalErrorWithCore everywhere.
Replaced some with InternalWarning or InternalAnalyzerError, the later
being a new method which signals the analyzer to not process further
input. Some usages I just removed if they didn't make sense or clearly
couldn't happen. Also did some minor refactors of related code while
reviewing/exploring ways to get rid of InternalError usages.
Also, for TCP content file write failures there's a new event:
"contents_file_write_failure".
Moved this functionality to be internal instead of in the script-layer
event handlers. The issue with the later is that bad things can happen
between the time a reporter event handler is dispatched and the time it
is executed, and if bro crashes in that time, the message may never be
seen/logged.
Addressed #930 (and revisits #836).
Internally, all BROv6 preprocessor switches were removed and
addr/subnet representations wrapped in the new IPAddr/IPPrefix classes.
Some script-layer changes of note:
- dns_AAAA_reply event signature changed: the string representation
of an IPv6 addr is easily derived from the addr value, it doesn't
need to be another parameter. This event also now generated directly
by the DNS analyzer instead of being "faked" into a dns_A_reply event.
- removed addr_to_count BIF. It used to return the host-order
count representation of IPv4 addresses only. To make it more
generic, we might later add a BIF to return a vector of counts
in order to support IPv6.
- changed the result of enclosing addr variables in vertical pipes
(e.g. |my_addr|) to return the bit-width of the address type which
is 128 for IPv6 and 32 for IPv4. It used to function the same
way as addr_to_count mentioned above.
- remove bro_has_ipv6 BIF
Currently, a lot of interpreter runtime errors, such as an access to
an unset optional record field, cause Bro to abort with an internal
error. This is an experimental branch that turns such errors into
non-fatal runtime errors by internally raising exceptions. These are
caught upstream and processing continues afterwards.
For now, not many errors actually raise exceptions (the example above
does though). We'll need to go through them eventually and adapt the
current Internal() calls (and potentially others). More generally, at
some point we should cleanup the interpreter error handling (unifying
errors reported at parse- and runtime; and switching to exceptions for
all Expr/Stmt/Vals). But that's a larger change and left for later.
The main question for now is if this code is already helpful enough to
go into 2.0. It will quite likely prevent a number of crashes due to
script errors.
Both related to Val lists constructed as arguments to events that were
not freed because the event function was never called (e.g. no handlers).
Addresses #574
Binpac exceptions caught in Analyzer.cc are passed to Reporter::Weird
and from there to Reporter::WeirdHelper. WeirdHelper has var args, to
support passing them on to DoLog, but there were no forced format
strings. Since the binpac exception can contain network data which can
contain %-characters, that caused segfaults.
When not reporting via events, the final contents of the message buffer
after formatting was being used as a format string to fprintf instead of
writing out the actual string.
* origin/topic/robin/reporting:
Syslog BiF now goes through the reporter as well.
Avoiding infinite loops when an error message handlers triggers errors itself.
Renaming the Logger to Reporter.
Overhauling the internal reporting of messages to the user.
Updating a bunch of tests/baselines as well.
Conflicts:
aux/broccoli
policy.old/alarm.bro
policy/all.bro
policy/bro.init
policy/frameworks/notice/weird.bro
policy/notice.bro
src/SSL-binpac.cc
src/bro.bif
src/main.cc
