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fix(userspace/engine): solve issues in describing rules/macros/lists

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Signed-off-by: Jason Dellaluce <jasondellaluce@gmail.com>
This commit is contained in:
Jason Dellaluce 2023-09-06 13:12:31 +00:00 committed by poiana
parent 8f411f3d3b
commit dc264a0577
2 changed files with 120 additions and 105 deletions
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210
userspace/engine/falco_engine.cpp
View File

@ -506,6 +506,16 @@ std::size_t falco_engine::add_source(const std::string &source,
return m_sources.insert(src, source);
}
template <typename T> inline Json::Value sequence_to_json_array(const T& seq)
{
Json::Value ret = Json::arrayValue;
for (auto it = seq.begin(); it != seq.end(); it++)
{
ret.append(*it);
}
return ret;
}
void falco_engine::describe_rule(std::string *rule, const std::vector<std::shared_ptr<sinsp_plugin>>& plugins, bool json) const
{
if(!json)
@ -535,9 +545,20 @@ void falco_engine::describe_rule(std::string *rule, const std::vector<std::share
return;
}
// use previously-loaded collector definitions to obtain a compiled
// output of rules, macros, and lists.
// note: we ignore the loading result (errors, warnings), as they should have
// already been checked when previously-loading the rules files. Thus, we
// assume that the definitions will give no compilation error.
rule_loader::configuration cfg("", m_sources, "");
cfg.output_extra = m_extra;
cfg.replace_output_container_info = m_replace_container_info;
rule_loader::compiler::compile_output compiled;
rule_loader::compiler().compile(cfg, m_rule_collector, compiled);
// use collected and compiled info to print a json output
Json::FastWriter writer;
std::string json_str;
if(!rule)
{
// In this case we build json information about
@ -573,33 +594,33 @@ void falco_engine::describe_rule(std::string *rule, const std::vector<std::share
// Store information about rules
Json::Value rules_array = Json::arrayValue;
for(const auto& r : m_rules)
for(const auto& r : compiled.rules)
{
auto ri = m_rule_collector.rules().at(r.name);
auto info = m_rule_collector.rules().at(r.name);
Json::Value rule;
get_json_details(rule, r, *ri, plugins);
// Append to rule array
get_json_details(rule, r, *info, plugins);
rules_array.append(rule);
}
output["rules"] = rules_array;
// Store information about macros
Json::Value macros_array = Json::arrayValue;
for(const auto &m : m_rule_collector.macros())
for(const auto &m : compiled.macros)
{
auto info = m_rule_collector.macros().at(m.name);
Json::Value macro;
get_json_details(macro, m);
get_json_details(macro, m, *info, plugins);
macros_array.append(macro);
}
output["macros"] = macros_array;
// Store information about lists
Json::Value lists_array = Json::arrayValue;
for(const auto &l : m_rule_collector.lists())
for(const auto &l : compiled.lists)
{
auto info = m_rule_collector.lists().at(l.name);
Json::Value list;
get_json_details(list, l);
get_json_details(list, l, *info, plugins);
lists_array.append(list);
}
output["lists"] = lists_array;
@ -626,69 +647,61 @@ void falco_engine::describe_rule(std::string *rule, const std::vector<std::share
void falco_engine::get_json_details(
Json::Value &out,
const falco_rule &r,
const rule_loader::rule_info &ri,
const rule_loader::rule_info &info,
const std::vector<std::shared_ptr<sinsp_plugin>>& plugins) const
{
Json::Value rule_info;
// Fill general rule information
rule_info["name"] = r.name;
rule_info["condition"] = ri.cond;
rule_info["condition"] = info.cond;
rule_info["priority"] = format_priority(r.priority, false);
rule_info["output"] = r.output;
rule_info["output"] = info.output;
rule_info["description"] = r.description;
rule_info["enabled"] = ri.enabled;
rule_info["enabled"] = info.enabled;
rule_info["source"] = r.source;
Json::Value tags = Json::arrayValue;
for(const auto &t : ri.tags)
{
tags.append(t);
}
rule_info["tags"] = tags;
rule_info["tags"] = sequence_to_json_array(info.tags);
out["info"] = rule_info;
// Parse rule condition and build the AST
// Assumption: no exception because rules have already been loaded.
auto ast = libsinsp::filter::parser(ri.cond).parse();
// Parse rule condition and build the non-compiled AST
// Assumption: no error because rules have already been loaded.
auto ast = libsinsp::filter::parser(info.cond).parse();
// get details related to the condition's filter
filter_details details;
filter_details compiled_details;
Json::Value json_details;
for(const auto &m : m_rule_collector.macros())
{
details.known_macros.insert(m.name);
compiled_details.known_macros.insert(m.name);
}
for(const auto &l : m_rule_collector.lists())
{
details.known_lists.insert(l.name);
compiled_details.known_lists.insert(l.name);
}
filter_details_resolver().run(ast.get(), details);
get_json_filter_details(json_details, details);
out["details"] = json_details;
filter_details_resolver().run(r.condition.get(), compiled_details);
out["details"]["macros"] = sequence_to_json_array(details.macros);
out["details"]["lists"] = sequence_to_json_array(details.lists);
out["details"]["operators"] = sequence_to_json_array(compiled_details.operators);
out["details"]["condition_fields"] = sequence_to_json_array(compiled_details.fields);
// Get fields from output string
auto fmt = create_formatter(r.source, r.output);
std::vector<std::string> out_fields;
fmt->get_field_names(out_fields);
Json::Value outputFields = Json::arrayValue;
for(const auto &of : out_fields)
{
outputFields.append(of);
}
out["details"]["output_fields"] = outputFields;
out["details"]["output_fields"] = sequence_to_json_array(out_fields);
// Get fields from exceptions
Json::Value exception_fields = Json::arrayValue;
for(const auto &f : r.exception_fields)
{
exception_fields.append(f);
}
out["details"]["exception_fields"] = exception_fields;
out["details"]["exception_fields"] = sequence_to_json_array(r.exception_fields);
// Get names and operators from exceptions
Json::Value exception_names = Json::arrayValue;
Json::Value exception_operators = Json::arrayValue;
for(const auto &e : ri.exceptions)
for(const auto &e : info.exceptions)
{
exception_names.append(e.name);
if(e.comps.is_list)
@ -719,9 +732,13 @@ void falco_engine::get_json_details(
// Store event types
Json::Value events;
get_json_evt_types(events, ri.source, details);
get_json_evt_types(events, info.source, r.condition.get());
out["details"]["events"] = events;
// Store compiled condition and output
out["details"]["condition_compiled"] = libsinsp::filter::ast::as_string(r.condition.get());
out["details"]["output_compiled"] = r.output;
// Compute the plugins that are actually used by this rule. This is involves:
// - The rule's event source, that can be implemented by a plugin
// - The fields used in the rule's condition, output, and exceptions
@ -729,59 +746,86 @@ void falco_engine::get_json_details(
// match plugin-provided async events
Json::Value used_plugins;
// note: making a union of conditions's and output's fields
// note: the condition's AST should include all resolved refs and exceptions
details.fields.insert(out_fields.begin(), out_fields.end());
get_json_used_plugins(used_plugins, ri.source, details.evtnames, details.fields, plugins);
// note: the condition's AST accounts for all the resolved refs and exceptions
compiled_details.fields.insert(out_fields.begin(), out_fields.end());
get_json_used_plugins(used_plugins, info.source, compiled_details.evtnames, compiled_details.fields, plugins);
out["details"]["plugins"] = used_plugins;
}
void falco_engine::get_json_details(
Json::Value& out,
const rule_loader::macro_info& m) const
const falco_macro& m,
const rule_loader::macro_info& info,
const std::vector<std::shared_ptr<sinsp_plugin>>& plugins) const
{
Json::Value macro_info;
macro_info["name"] = m.name;
macro_info["condition"] = m.cond;
macro_info["condition"] = info.cond;
out["info"] = macro_info;
// Parse rule condition and build the AST
// Parse the macro condition and build the non-compiled AST
// Assumption: no exception because rules have already been loaded.
auto ast = libsinsp::filter::parser(m.cond).parse();
auto ast = libsinsp::filter::parser(info.cond).parse();
// get details related to the condition's filter
filter_details details;
filter_details compiled_details;
Json::Value json_details;
for(const auto &m : m_rule_collector.macros())
{
details.known_macros.insert(m.name);
compiled_details.known_macros.insert(m.name);
}
for(const auto &l : m_rule_collector.lists())
{
details.known_lists.insert(l.name);
compiled_details.known_lists.insert(l.name);
}
filter_details_resolver().run(ast.get(), details);
get_json_filter_details(json_details, details);
out["details"] = json_details;
filter_details_resolver().run(m.condition.get(), compiled_details);
out["details"]["used"] = m.used;
out["details"]["macros"] = sequence_to_json_array(details.macros);
out["details"]["lists"] = sequence_to_json_array(details.lists);
out["details"]["operators"] = sequence_to_json_array(compiled_details.operators);
out["details"]["condition_fields"] = sequence_to_json_array(compiled_details.fields);
// Store event types
Json::Value events;
get_json_evt_types(events, "", details);
get_json_evt_types(events, "", m.condition.get());
out["details"]["events"] = events;
// Store compiled condition
out["details"]["condition_compiled"] = libsinsp::filter::ast::as_string(m.condition.get());
// Compute the plugins that are actually used by this macro.
// Note: macros have no specidic source, we need to set an empty list of used
// plugins because we can't be certain about their actual usage. For example,
// if a macro uses a plugin's field, we can't be sure which plugin actually
// is used until we resolve the macro ref in a rule providing a source for
// disambiguation.
out["details"]["plugins"] = Json::arrayValue;
}
void falco_engine::get_json_details(
Json::Value& out,
const rule_loader::list_info& l) const
const falco_list& l,
const rule_loader::list_info& info,
const std::vector<std::shared_ptr<sinsp_plugin>>& plugins) const
{
Json::Value list_info;
list_info["name"] = l.name;
// note: the syntactic definitions still has the list refs unresolved
Json::Value items = Json::arrayValue;
Json::Value lists = Json::arrayValue;
for(const auto &i : l.items)
for(const auto &i : info.items)
{
if(m_rule_collector.lists().at(i) != nullptr)
// if an item is present in the syntactic def of a list, but not
// on the compiled_items of the same list, then we can assume it
// being a resolved list ref
if(std::find(l.items.begin(), l.items.end(), i) == l.items.end())
{
lists.append(i);
continue;
@ -791,62 +835,32 @@ void falco_engine::get_json_details(
list_info["items"] = items;
out["info"] = list_info;
out["details"]["used"] = l.used;
out["details"]["lists"] = lists;
}
void falco_engine::get_json_filter_details(
Json::Value& out,
const filter_details& details) const
{
Json::Value macros = Json::arrayValue;
for(const auto &m : details.macros)
{
macros.append(m);
}
out["macros"] = macros;
Json::Value operators = Json::arrayValue;
for(const auto &o : details.operators)
{
operators.append(o);
}
out["operators"] = operators;
Json::Value condition_fields = Json::arrayValue;
for(const auto &f : details.fields)
{
condition_fields.append(f);
}
out["condition_fields"] = condition_fields;
Json::Value lists = Json::arrayValue;
for(const auto &l : details.lists)
{
lists.append(l);
}
out["lists"] = lists;
out["details"]["items_compiled"] = sequence_to_json_array(l.items);
out["details"]["plugins"] = Json::arrayValue; // always empty
}
void falco_engine::get_json_evt_types(
Json::Value& out,
const std::string& source,
const filter_details& details) const
libsinsp::filter::ast::expr* ast) const
{
out = Json::arrayValue;
for (const auto& n : details.evtnames)
// note: this duplicates part of the logic of evttype_index_ruleset,
// not good but it's our best option for now
if (source.empty() || source == falco_common::syscall_source)
{
out.append(n);
auto evtcodes = libsinsp::filter::ast::ppm_event_codes(ast);
evtcodes.insert(ppm_event_code::PPME_ASYNCEVENT_E);
auto syscodes = libsinsp::filter::ast::ppm_sc_codes(ast);
auto syscodes_to_evt_names = libsinsp::events::sc_set_to_event_names(syscodes);
auto evtcodes_to_evt_names = libsinsp::events::event_set_to_names(evtcodes, false);
out = sequence_to_json_array(unordered_set_union(syscodes_to_evt_names, evtcodes_to_evt_names));
}
// plugin-implemented sources always match pluginevent.
// note: macros have no source and can potentially be referenced in a rule
// used for a plugin-implemented source.
if(source.empty() || source != falco_common::syscall_source)
else
{
for (const auto& n : libsinsp::events::event_set_to_names({PPME_PLUGINEVENT_E}, false))
{
out.append(n);
}
out = sequence_to_json_array(libsinsp::events::event_set_to_names(
{ppm_event_code::PPME_PLUGINEVENT_E, ppm_event_code::PPME_ASYNCEVENT_E}));
}
}

15
userspace/engine/falco_engine.h
View File

@ -306,21 +306,22 @@ private:
void get_json_details(
Json::Value& out,
const falco_rule& r,
const rule_loader::rule_info& ri,
const rule_loader::rule_info& info,
const std::vector<std::shared_ptr<sinsp_plugin>>& plugins) const;
void get_json_details(
Json::Value& out,
const rule_loader::macro_info& m) const;
const falco_macro& m,
const rule_loader::macro_info& info,
const std::vector<std::shared_ptr<sinsp_plugin>>& plugins) const;
void get_json_details(
Json::Value& out,
const rule_loader::list_info& l) const;
void get_json_filter_details(
Json::Value& out,
const filter_details& details) const;
const falco_list& l,
const rule_loader::list_info& info,
const std::vector<std::shared_ptr<sinsp_plugin>>& plugins) const;
void get_json_evt_types(
Json::Value& out,
const std::string& source,
const filter_details& details) const;
libsinsp::filter::ast::expr* ast) const;
void get_json_used_plugins(
Json::Value& out,
const std::string& source,