Skip to content

Commit

Permalink
Plugins support in falco executable
Browse files Browse the repository at this point in the history 
Update the falco binary to add support for plugins.

- Keep track of an "event source", which is initially "syscall" but
  changes to the input plugin's source if an source plugin ends up being
  loaded.

- New argument --list-plugins will return info on any loaded plugins,
  using sinsp_plugin::plugin_infos.

- Create filter/formatter factories for plugins. This ensures that
  filterchecks for syscalls are not used for plugins and vice versa.

- Use sinsp_plugin::register_plugin() to load each plugin found in
  config. The first source plugin found (if any) calls
  engine->add_source withthe source plugin's event source.

- If a second source plugin is found, exit with an error.

- Extractor plugins must be compatible with the event source (usually
  the plugin event source, but could be "syscall"). If not, exit with
  an error.

- Multiple Extractor plugins are allowed, but they can not have
  overlapping compatible event sources. This is mostly to avoid
  confusion, but we might change this later.

- After loading plugins, use engine is_plugin_compatible to ensure
  that the plugin is compatible with any required_plugin_version blocks
  in falco rules.

- Normally falco would log warnings if too many SCAP_TIMEOUT results
  were received. These are more expected when using plugins, so only
  log these warnings when using syscalls.

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>
  • Loading branch information
@mstemm @leogr
@ldegio @sai-arigeli
3 people authored and sai-arigeli committed Nov 16, 2021
1 parent 2cfda0d commit 6eaf5b0
Showing 1 changed file with 143 additions and 9 deletions.
152 changes: 143 additions & 9 deletions userspace/falco/falco.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,8 @@ limitations under the License.

#include <sinsp.h>
#include <filter.h>
#include <eventformatter.h>
#include <plugin.h>

#include "logger.h"
#include "utils.h"
Expand Down Expand Up @@ -135,6 +137,7 @@ static void usage()
" -l <rule> Show the name and description of the rule with name <rule> and exit.\n"
" --list [<source>] List all defined fields. If <source> is provided, only list those fields for\n"
" the source <source>. Current values for <source> are \"syscall\", \"k8s_audit\"\n"
" --list-plugins Print info on all loaded plugins and exit.\n"
#ifndef MINIMAL_BUILD
" -m <url[,marathon_url]>, --mesos-api <url[,marathon_url]>\n"
" Enable Mesos support by connecting to the API server\n"
Expand Down Expand Up @@ -247,6 +250,7 @@ static std::string read_file(std::string filename)
uint64_t do_inspect(falco_engine *engine,
falco_outputs *outputs,
sinsp* inspector,
std::string &event_source,
falco_configuration &config,
syscall_evt_drop_mgr &sdropmgr,
uint64_t duration_to_tot_ns,
Expand Down Expand Up @@ -311,7 +315,8 @@ uint64_t do_inspect(falco_engine *engine,
if(unlikely(ev == nullptr))
{
timeouts_since_last_success_or_msg++;
if(timeouts_since_last_success_or_msg > config.m_syscall_evt_timeout_max_consecutives)
if(event_source == syscall_source &&
(timeouts_since_last_success_or_msg > config.m_syscall_evt_timeout_max_consecutives))
{
std::string rule = "Falco internal: timeouts notification";
std::string msg = rule + ". " + std::to_string(config.m_syscall_evt_timeout_max_consecutives) + " consecutive timeouts without event.";
Expand Down Expand Up @@ -375,7 +380,7 @@ uint64_t do_inspect(falco_engine *engine,
// engine, which will match the event against the set
// of rules. If a match is found, pass the event to
// the outputs.
unique_ptr<falco_engine::rule_result> res = engine->process_event(syscall_source, ev);
unique_ptr<falco_engine::rule_result> res = engine->process_event(event_source, ev);
if(res)
{
outputs->handle_event(res->evt, res->rule, res->source, res->priority_num, res->format, res->tags);
Expand Down Expand Up @@ -509,6 +514,7 @@ int falco_init(int argc, char **argv)
bool print_ignored_events = false;
bool list_flds = false;
string list_flds_source = "";
bool list_plugins = false;
bool print_support = false;
string cri_socket_path;
bool cri_async = true;
Expand Down Expand Up @@ -550,6 +556,7 @@ int falco_init(int argc, char **argv)
{"k8s-api", required_argument, 0, 'k'},
{"k8s-node", required_argument, 0},
{"list", optional_argument, 0},
{"list-plugins", no_argument, 0},
{"mesos-api", required_argument, 0, 'm'},
{"option", required_argument, 0, 'o'},
{"pidfile", required_argument, 0, 'P'},
Expand Down Expand Up @@ -742,6 +749,10 @@ int falco_init(int argc, char **argv)
list_flds_source = optarg;
}
}
else if (string(long_options[long_index].name) == "list-plugins")
{
list_plugins = true;
}
else if (string(long_options[long_index].name) == "stats-interval")
{
stats_interval = atoi(optarg);
Expand Down Expand Up @@ -816,12 +827,6 @@ int falco_init(int argc, char **argv)
engine->add_source(syscall_source, syscall_filter_factory, syscall_formatter_factory);
engine->add_source(k8s_audit_source, k8s_audit_filter_factory, k8s_audit_formatter_factory);

if(list_flds)
{
list_source_fields(engine, names_only, list_flds_source);
return EXIT_SUCCESS;
}

if(disable_sources.size() > 0)
{
auto it = disable_sources.begin();
Expand Down Expand Up @@ -916,10 +921,127 @@ int falco_init(int argc, char **argv)
throw std::runtime_error("Could not find configuration file at " + conf_filename);
}

// The event source is syscall by default. If an input
// plugin was found, the source is the source of that
// plugin.
std::string event_source = syscall_source;

// All filterchecks created by plugins go in this
// list. If we ever support multiple event sources at
// the same time, this (and the below factories) will
// have to be a map from event source to filtercheck
// list.
filter_check_list plugin_filter_checks;

// Factories that can create filters/formatters for
// the (single) source supported by the (single) input plugin.
std::shared_ptr<gen_event_filter_factory> plugin_filter_factory(new sinsp_filter_factory(inspector, plugin_filter_checks));
std::shared_ptr<gen_event_formatter_factory> plugin_formatter_factory(new sinsp_evt_formatter_factory(inspector, plugin_filter_checks));

std::shared_ptr<sinsp_plugin> input_plugin;
std::list<std::shared_ptr<sinsp_plugin>> extractor_plugins;
for(auto &p : config.m_plugins)
{
falco_logger::log(LOG_INFO, "Loading plugin (" + p.m_name + ") from file " + p.m_library_path + "\n");

std::shared_ptr<sinsp_plugin> plugin = sinsp_plugin::register_plugin(inspector,
p.m_library_path,
(p.m_init_config.empty() ? NULL : (char *)p.m_init_config.c_str()),
plugin_filter_checks);

if(plugin->type() == TYPE_SOURCE_PLUGIN)
{
sinsp_source_plugin *splugin = static_cast<sinsp_source_plugin *>(plugin.get());

if(input_plugin)
{
throw std::invalid_argument(string("Can not load multiple source plugins. ") + input_plugin->name() + " already loaded");
}

input_plugin = plugin;
event_source = splugin->event_source();

inspector->set_input_plugin(p.m_name);
if(!p.m_open_params.empty())
{
inspector->set_input_plugin_open_params(p.m_open_params.c_str());
}

engine->add_source(event_source, plugin_filter_factory, plugin_formatter_factory);

} else {
extractor_plugins.push_back(plugin);
}
}

// Ensure that extractor plugins are compatible with the event source.
// Also, ensure that extractor plugins don't have overlapping compatible event sources.
std::set<std::string> compat_sources_seen;
for(auto plugin : extractor_plugins)
{
// If the extractor plugin names compatible sources,
// ensure that the input plugin's source is in the list
// of compatible sources.
sinsp_extractor_plugin *eplugin = static_cast<sinsp_extractor_plugin *>(plugin.get());
const std::set<std::string> &compat_sources = eplugin->extract_event_sources();
if(input_plugin &&
!compat_sources.empty())
{
if (compat_sources.find(event_source) == compat_sources.end())
{
throw std::invalid_argument(string("Extractor plugin not compatible with event source ") + event_source);
}

for(const auto &compat_source : compat_sources)
{
if(compat_sources_seen.find(compat_source) != compat_sources_seen.end())
{
throw std::invalid_argument(string("Extractor plugins have overlapping compatible event source ") + compat_source);
}
compat_sources_seen.insert(compat_source);
}
}
}

if(config.m_json_output)
{
syscall_formatter_factory->set_output_format(gen_event_formatter::OF_JSON);
k8s_audit_formatter_factory->set_output_format(gen_event_formatter::OF_JSON);
plugin_formatter_factory->set_output_format(gen_event_formatter::OF_JSON);
}

std::list<sinsp_plugin::info> infos = sinsp_plugin::plugin_infos(inspector);

if(list_plugins)
{
std::ostringstream os;

for(auto &info : infos)
{
os << "Name: " << info.name << std::endl;
os << "Description: " << info.description << std::endl;
os << "Contact: " << info.contact << std::endl;
os << "Version: " << info.plugin_version.as_string() << std::endl;

if(info.type == TYPE_SOURCE_PLUGIN)
{
os << "Type: source plugin" << std::endl;
os << "ID: " << info.id << std::endl;
}
else
{
os << "Type: extractor plugin" << std::endl;
}
}

printf("%lu Plugins Loaded:\n\n%s\n", infos.size(), os.str().c_str());
return EXIT_SUCCESS;
}

if(list_flds)
{
list_source_fields(engine, names_only, list_flds_source);
return EXIT_SUCCESS;
}

if (rules_filenames.size())
Expand Down Expand Up @@ -962,6 +1084,17 @@ int falco_init(int argc, char **argv)
required_engine_versions[filename] = required_engine_version;
}

// Ensure that all plugins are compatible with the loaded set of rules
for(auto &info : infos)
{
std::string required_version;

if(!engine->is_plugin_compatible(info.name, info.plugin_version.as_string(), required_version))
{
throw std::invalid_argument(std::string("Plugin ") + info.name + " version " + info.plugin_version.as_string() + " not compatible with required plugin version " + required_version);
}
}

// You can't both disable and enable rules
if((disabled_rule_substrings.size() + disabled_rule_tags.size() > 0) &&
enabled_rule_tags.size() > 0) {
Expand Down Expand Up @@ -1362,7 +1495,7 @@ int falco_init(int argc, char **argv)
falco_logger::log(LOG_DEBUG, "Setting metadata download chunk wait time to " + to_string(config.m_metadata_download_chunk_wait_us) + " μs\n");
falco_logger::log(LOG_DEBUG, "Setting metadata download watch frequency to " + to_string(config.m_metadata_download_watch_freq_sec) + " seconds\n");
inspector->set_metadata_download_params(config.m_metadata_download_max_mb * 1024 * 1024, config.m_metadata_download_chunk_wait_us, config.m_metadata_download_watch_freq_sec);

if(trace_filename.empty() && config.m_webserver_enabled && !disable_k8s_audit)
{
std::string ssl_option = (config.m_webserver_ssl_enabled ? " (SSL)" : "");
Expand Down Expand Up @@ -1406,6 +1539,7 @@ int falco_init(int argc, char **argv)
num_evts = do_inspect(engine,
outputs,
inspector,
event_source,
config,
sdropmgr,
uint64_t(duration_to_tot*ONE_SECOND_IN_NS),
Expand Down

0 comments on commit 6eaf5b0

Please sign in to comment.