Define a falco_load_result abstract class for use in new load_rules
methods. It's abstract so the implementation details in
rule_loader/rule_reader can be hidden from someone who wants to use
the API to load rules and work with a result.
The class defines a set of error codes/warning codes and has static
methods to get a short and long description of each error/warning.
There are virtual methods to access the important parts of a result:
- successful or not
- a string representation of the result, suitable for display to
users. Takes a verbose argument. When verbose is true, the string is
multi-line and has full details, including locations, item names,
etc. When verbose is false, the string is single-line and just
returns error codes.
- a json representation of the result, suitable for automated
parsing/interpretation later.
Signed-off-by: Mark Stemm <mark.stemm@gmail.com>
The first warnings we support involve the unsafe comparisons with <NA>, which were present
in the legacy regression tests for PSPs.
Signed-off-by: Jason Dellaluce <jasondellaluce@gmail.com>
The rule_reader class is responsible of parsing the YAML ruleset text and of using the rule_loader
to store the new definition in the internal state. This is a first step towards separating the YAML
reading logic from the rule parsing one. Potentially, this will allow us to read rulesets from another
YAML library or from something different than YAML files too.
Signed-off-by: Jason Dellaluce <jasondellaluce@gmail.com>
The lua_filter_helper class is a simple Lua wrapper that can be used in the Lua rule loader to
parse/compile rule filters, and manipulate them to resolve/replace list and macro references.
Signed-off-by: Jason Dellaluce <jasondellaluce@gmail.com>
The Lua PEG parser is not longer needed, since we now use the new filter parser implemented
in libsinsp.
Signed-off-by: Jason Dellaluce <jasondellaluce@gmail.com>
Instead of having .lua files external to the program responsible for
loading rules, embed the contents of those files into the executable
and load them as strings instead of as files:
Add a cmake custom command below userspace/engine/lua that calls a
bash script lua-to-cpp.sh to generate falco_engine_lua_files.{cpp,hh}
that are compiled into the falco engine library.
The script creates a .cpp file that has const char * symbols for each
file, as well as lists of files that should be loaded when the falco
engine is loaded. There are actually two lists:
- lua_module_strings: these are loaded and also added to the lua
runtime package.preload table, so they are available when lua code
require()s them.
- lua_code_strings: these are loaded *and* evaluated, so the functions
in them are availble to be called from C++.
This simplifies some of the falco_common methods, as there's no need
to keep track of a "main" lua file to load or paths from which the lua
loader should find files for modules, and there's no need to keep
track of an "alternate" lua directory that occurs for debug builds.
Also, there's no need to include any .lua files in the installed
packages, as they're built into the falco binary.
Signed-off-by: Mark Stemm <mark.stemm@gmail.com>
It took a while, but we remembered to finish moving the token_bucket
from falco engine to libs. There were 2 copies for a while.
This brings over one change to libs--to have an optional timer
function.
Co-authored-by: Leonardo Grasso <me@leonardograsso.com>
Co-authored-by: Loris Degioanni <loris@sysdig.com>
Signed-off-by: Mark Stemm <mark.stemm@gmail.com>
Support the notion of a message for all fields in a single class, and
making sure it's wrapped as well as the other fields.
This is used to display a single message about how indexing working for
ka.* filter fields and what IDX_ALLOWED/IDX_NUMERIC/IDX_KEY means,
rather than repeating the same text over and over in every field.
The wrapping is handled by a function falco::utils::wrap_text.
Signed-off-by: Mark Stemm <mark.stemm@gmail.com>
* Add support for container metaevent to detect container spawning
Create a new macro "container_started" to check both the old and
the new check.
Also, only look for execve exit events with vpid=1.
* Use TBB_INCLUDE_DIR for consistency w sysdig,agent
Previously it was a mix of TBB_INCLUDE and TBB_INCLUDE_DIR.
* Build using matching sysdig branch, if exists
* Add new json/webserver libs, embedded webserver
Add two new external libraries:
- nlohmann-json is a better json library that has stronger use of c++
features like type deduction, better conversion from stl structures,
etc. We'll use it to hold generic json objects instead of jsoncpp.
- civetweb is an embeddable webserver that will allow us to accept
posted json data.
New files webserver.{cpp,h} start an embedded webserver that listens for
POSTS on a configurable url and passes the json data to the falco
engine.
New falco config items are under webserver:
- enabled: true|false. Whether to start the embedded webserver or not.
- listen_port. Port that webserver listens on
- k8s_audit_endpoint: uri on which to accept POSTed k8s audit events.
(This commit doesn't compile entirely on its own, but we're grouping
these related changes into one commit for clarity).
* Don't use relative paths to find lua code
You can look directly below PROJECT_SOURCE_DIR.
* Reorganize compiler lua code
The lua compiler code is generic enough to work on more than just
sinsp-based rules, so move the parts of the compiler related to event
types and filterchecks out into a standalone lua file
sinsp_rule_utils.lua.
The checks for event types/filterchecks are now done from rule_loader,
and are dependent on a "source" attribute of the rule being
"sinsp". We'll be adding additional types of events next that come from
sources other than system calls.
* Manage separate syscall/k8s audit rulesets
Add the ability to manage separate sets of rules (syscall and
k8s_audit). Stop using the sinsp_evttype_filter object from the sysdig
repo, replacing it with falco_ruleset/falco_sinsp_ruleset from
ruleset.{cpp,h}. It has the same methods to add rules, associate them
with rulesets, and (for syscall) quickly find the relevant rules for a
given syscall/event type.
At the falco engine level, there are new parallel interfaces for both
types of rules (syscall and k8s_audit) to:
- add a rule: add_k8s_audit_filter/add_sinsp_filter
- match an event against rules, possibly returning a result:
process_sinsp_event/process_k8s_audit_event
At the rule loading level, the mechanics of creating filterchecks
objects is handled two factories (sinsp_filter_factory and
json_event_filter_factory), both of which are held by the engine.
* Handle multiple rule types when parsing rules
Modify the steps of parsing a rule's filter expression to handle
multiple types of rules. Notable changes:
- In the rule loader/ast traversal, pass a filter api object down,
which is passed back up in the lua parser api calls like nest(),
bool_op(), rel_expr(), etc.
- The filter api object is either the sinsp factory or k8s audit
factory, depending on the rule type.
- When the rule is complete, the complete filter is passed to the
engine using either add_sinsp_filter()/add_k8s_audit_filter().
* Add multiple output formatting types
Add support for multiple output formatters. Notable changes:
- The falco engine is passed along to falco_formats to gain access to
the engine's factories.
- When creating a formatter, the source of the rule is passed along
with the format string, which controls which kind of output formatter
is created.
Also clean up exception handling a bit so all lua callbacks catch all
exceptions and convert them into lua errors.
* Add support for json, k8s audit filter fields
With some corresponding changes in sysdig, you can now create general
purpose filter fields and events, which can be tied together with
nesting, expressions, and relational operators. The classes here
represent an instance of these fields devoted to generic json objects as
well as k8s audit events. Notable changes:
- json_event: holds a json object, used by all of the below
- json_event_filter_check: Has the ability to extract values out of a
json_event object and has the ability to define macros that associate
a field like "group.field" with a json pointer expression that
extracts a single property's value out of the json object. The basic
field definition also allows creating an index
e.g. group.field[index], where a std::function is responsible for
performing the indexing. This class has virtual void methods so it
must be overridden.
- jevt_filter_check: subclass of json_event_filter_check and defines
the following fields:
- jevt.time/jevt.rawtime: extracts the time from the underlying json object.
- jevt.value[<json pointer>]: general purpose way to extract any
json value out of the underlying object. <json pointer> is a json
pointer expression
- jevt.obj: Return the entire object, stringified.
- k8s_audit_filter_check: implements fields that extract values from
k8s audit events. Most of the implementation is in the form of macros
like ka.user.name, ka.uri, ka.target.name, etc. that just use json
pointers to extact the appropriate value from a k8s audit event. More
advanced fields like ka.uri.param, ka.req.container.image use
indexing to extract individual values out of maps or arrays.
- json_event_filter_factory: used by things like the lua parser api,
output formatter, etc to create the necessary objects and return
them.
- json_event_formatter: given a format string, create the necessary
fields that will be used to create a resolved string when given a
json_event object.
* Add ability to list fields
Similar to sysdig's -l option, add --list (<source>) to list the fields
supported by falco. With no source specified, will print all
fields. Source can be "syscall" for inspector fields e.g. what is
supported by sysdig, or "k8s_audit" to list fields supported only by the
k8s audit support in falco.
* Initial set of k8s audit rules
Add an initial set of k8s audit rules. They're broken into 3 classes of
rules:
- Suspicious activity: this includes things like:
- A disallowed k8s user performing an operation
- A disallowed container being used in a pod.
- A pod created with a privileged pod.
- A pod created with a sensitive mount.
- A pod using host networking
- Creating a NodePort Service
- A configmap containing private credentials
- A request being made by an unauthenticated user.
- Attach/exec to a pod. (We eventually want to also do privileged
pods, but that will require some state management that we don't
currently have).
- Creating a new namespace outside of an allowed set
- Creating a pod in either of the kube-system/kube-public namespaces
- Creating a serviceaccount in either of the kube-system/kube-public
namespaces
- Modifying any role starting with "system:"
- Creating a clusterrolebinding to the cluster-admin role
- Creating a role that wildcards verbs or resources
- Creating a role with writable permissions/pod exec permissions.
- Resource tracking. This includes noting when a deployment, service,
- configmap, cluster role, service account, etc are created or destroyed.
- Audit tracking: This tracks all audit events.
To support these rules, add macros/new indexing functions as needed to
support the required fields and ways to index the results.
* Add ability to read trace files of k8s audit evts
Expand the use of the -e flag to cover both .scap files containing
system calls as well as jsonl files containing k8s audit events:
If a trace file is specified, first try to read it using the
inspector. If that throws an exception, try to read the first line as
json. If both fail, return an error.
Based on the results of the open, the main loop either calls
do_inspect(), looping over system events, or
read_k8s_audit_trace_file(), reading each line as json and passing it to
the engine and outputs.
* Example showing how to enable k8s audit logs.
An example of how to enable k8s audit logging for minikube.
* Add unit tests for k8s audit support
Initial unit test support for k8s audit events. A new multiplex file
falco_k8s_audit_tests.yaml defines the tests. Traces (jsonl files) are
in trace_files/k8s_audit and new rules files are in
test/rules/k8s_audit.
Current test cases include:
- User outside allowed set
- Creating disallowed pod.
- Creating a pod explicitly on the allowed list
- Creating a pod w/ a privileged container (or second container), or a
pod with no privileged container.
- Creating a pod w/ a sensitive mount container (or second container), or a
pod with no sensitive mount.
- Cases for a trace w/o the relevant property + the container being
trusted, and hostnetwork tests.
- Tests that create a Service w/ and w/o a NodePort type.
- Tests for configmaps: tries each disallowed string, ensuring each is
detected, and the other has a configmap with no disallowed string,
ensuring it is not detected.
- The anonymous user creating a namespace.
- Tests for all kactivity rules e.g. those that create/delete
resources as compared to suspicious activity.
- Exec/Attach to Pod
- Creating a namespace outside of an allowed set
- Creating a pod/serviceaccount in kube-system/kube-public namespaces
- Deleting/modifying a system cluster role
- Creating a binding to the cluster-admin role
- Creating a cluster role binding that wildcards verbs or resources
- Creating a cluster role with write/pod exec privileges
* Don't manually install gcc 4.8
gcc 4.8 should already be installed by default on the vm we use for
travis.
* Use correct copyright years.
Also include the start year.
* Improve copyright notices.
Use the proper start year instead of just 2018.
Add the right owner Draios dba Sysdig.
Add copyright notices to some files that were missing them.
The rules CMakeLists.txt, which controls the installation of the falco
rules files, was in the engine CMakeLists.txt, which meant that programs
that included the engine would also include rules files.
This may not always be desired, so move the rules CMakeLists.txt to the
main falco CMakeLists.txt instead.
Add token-bucket based rate limiting for falco notifications.
The token bucket is implemented in token_bucket.cpp (actually in the
engine directory, just to make it easier to include in other
programs). It maintains a current count of tokens (i.e. right to send a
notification). Its main method is claim(), which attemps to claim a
token and returns true if one was claimed successfully. It has a
configurable configurable max burst size and rate. The token bucket
gains "rate" tokens per second, up to a maximum of max_burst tokens.
These parameters are configurable in falco.yaml via the config
options (defaults shown):
outputs:
rate: 1
max_burst: 1000
In falco_outputs::handle_event(), try to claim a token, and if
unsuccessful log a debug message and return immediately.
