anonymous-functions, their closures, can now be sent over broker.
In order to send an anonymous function the receiver must have parsed
a definition of the functon, but it need not to have been evaluated.
See testing/btest/language/closure-sending.zeek for an example of how
this can be done.
This also sends their closures as well as the closures of regular
functions.
This allows anonymous functions in Zeek to capture their closures.
they do so by creating a copy of their enclosing frame and joining
that with their own frame.
There is no way to specify what specific items to capture from the
closure like C++, nor is there a nonlocal keyword like Python.
Attemptying to declare a local variable that has already been caught
by the closure will error nicely. At the worst this is an inconvenience
for people who are using lambdas which use the same variable names
as their closures.
As a result of functions copying their enclosing frames there is no
way for a function with a closure to reach back up and modify the
state of the frame that it was created in. This lets functions that
generate functions work as expected. The function can reach back and
modify its copy of the frame that it is captured in though.
Implementation wise this is done by creating two new subclasses in
Zeek. The first is a LambdaExpression which can be thought of as a
function generator. It gathers all of the ingredients for a function
at parse time, and then when evaluated creats a new version of that
function with the frame it is being evaluated in as a closure. The
second subclass is a ClosureFrame. This acts for most intents and
purposes like a regular Frame, but it routes lookups of values to its
closure as needed.
* origin/topic/robin/gh-239:
Undo a change to btest.cfg from a recent commit
Updating submodule.
Fix zeek-wrapper
Update for renaming BroControl to ZeekControl.
Updating submodule.
GH-239: Rename bro to zeek, bro-config to zeek-config, and bro-path-dev to zeek-path-dev.
Note - this compiles, but you cannot run Bro anymore - it crashes
immediately with a 0-pointer access. The reason behind it is that the
required clone functionality does not work anymore.
This also installs symlinks from "zeek" and "bro-config" to a wrapper
script that prints a deprecation warning.
The btests pass, but this is still WIP. broctl renaming is still
missing.
#239
Scripting errors/mistakes now consistently generate a runtime error
which have the behavior of unwinding the call stack all the way out of
the current event handler.
Before, such errors were not treated consistently and either aborted
the process entirely or emitted a message while continuing to execute
subsequent statements without well-defined behavior (possibly causing
a cascade of errors).
The previous behavior also would only unwind out of the current
function (if within a function body), not out the current event
handler, which is especially problematic for functions that return
a value: the caller is essentially left a mess with no way to deal
with it.
This also changes the behavior of the startup/initialization process
to abort if there's errors during bro_init() rather than continue one
to the main run loop. The `allow_init_errors` option may change this
new, default behavior.
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 configuration framework consists of three mostly distinct parts:
* option variables
* the config reader
* the script level framework
I will describe the three elements in the following.
Internally, this commit also performs a range of changes to the Input
manager; it marks a lot of functions as const and introduces a new
ValueToVal method (which could in theory replace the already existing
one - it is a bit more powerful).
This also changes SerialTypes to have a subtype for Values, just as
Fields already have it; I think it was mostly an oversight that this was
not introduced from the beginning. This should not necessitate any code
changes for people already using SerialTypes.
option variable
===============
The option keyword allows variables to be specified as run-tine options.
Such variables cannot be changed using normal assignments. Instead, they
can be changed using Option::set. It is possible to "subscribe" to
options and be notified when an option value changes.
Change handlers can also change values before they are applied; this
gives them the opportunity to reject changes. Priorities can be
specified if there are several handlers for one option.
Example script:
option testbool: bool = T;
function option_changed(ID: string, new_value: bool): bool
{
print fmt("Value of %s changed from %s to %s", ID, testbool, new_value);
return new_value;
}
event bro_init()
{
print "Old value", testbool;
Option::set_change_handler("testbool", option_changed);
Option::set("testbool", F);
print "New value", testbool;
}
config reader
=============
The config reader provides a way to read configuration files back into
Bro. Most importantly it automatically converts values to the correct
types. This is important because it is at least inconvenient (and
sometimes near impossible) to perform the necessary type conversions in
Bro scripts themselves. This is especially true for sets/vectors.
Configuration generally look like this:
[option name][tab/spaces][new variable value]
so, for example:
testaddr 2607:f8b0:4005:801::200e
testinterval 60
testtime 1507321987
test_set a b c d erdbeerschnitzel
The reader uses the option name to look up the type that variable has in
the Bro core and automatically converts the value to the correct type.
Example script use:
type Idx: record {
option_name: string;
};
type Val: record {
option_val: string;
};
global currconfig: table[string] of string = table();
event InputConfig::new_value(name: string, source: string, id: string, value: any)
{
print id, value;
}
event bro_init()
{
Input::add_table([$reader=Input::READER_CONFIG, $source="../configfile", $name="configuration", $idx=Idx, $val=Val, $destination=currconfig, $want_record=F]);
}
Script-level config framework
=============================
The script-level framework ties these two features together and makes
them a bit more convenient to use. Configuration files can simply be
specified by placing them into Config::config_files. The framework also
creates a config.log that shows all value changes that took place.
Usage example:
redef Config::config_files += {configfile};
export {
option testbool : bool = F;
}
The file is now monitored for changes; when a change occurs the
respective option values are automatically updated and the value change
is written to config.log.
handlers.
It's well known that changes to mutable event arguments, like tables,
become visible to all places where those values are used, including
subsequent handlers of the same event. However, there's a related case
that's more suprising: simply assigning *a new value* to an event
argument passes through, too. This commit fixes that behaviour. (We
even had a btest with a baseline reflecting the problen).
Broke out the stats collection into a bunch of new Bifs
in stats.bif. Scripts that use stats collection functions
have also been updated. More work to do.
* origin/topic/gilbert/plugin-api-tweak:
Updating plugin.hooks baseline so that test succeeds
Revert spacing change that shouldn't have been included with the previous changeset ... should fix all of the plugin tests save hooks, which needs to be updated.
More small fixes
Small fixes
Incremental
Re-updating plugin.hooks test to include new argument output (after merge).
Fixing logic errors in HandlePluginResult
Updating tests and tweaking HookArgument to include Frame support.
Incremental commit: implementing a wrapper for the Val class.
Reverting change to const status of network_time. Also, see FIXME: in Func.cc / HandlePluginResult ...
Tweaks to result handling to make things a little more sane.
Plugin API: minor change (adding parent frame) to support calling methods from hook. Also declare network time update argument to be const because good practice.
BIT-1270 #merged
Conflicts:
testing/btest/Baseline/plugins.hooks/output
with a MIME type.
Whenever that MIME is detected, Bro will now automatically activate
the analyzer. The interface mimics how well-known ports are defined
for protocol analyzers.
This isn't actually used by any existing file analyzer (because we
don't have any yet that target a specific file format), but there's a
test making sure it works.
