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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "action_parser.h"
#include <ctype.h>
#include <android-base/properties.h>
#include <android-base/strings.h>
#if defined(__ANDROID__)
#include "property_service.h"
#include "selinux.h"
#else
#include "host_init_stubs.h"
#endif
using android::base::GetBoolProperty;
using android::base::StartsWith;
namespace android {
namespace init {
namespace {
bool IsActionableProperty(Subcontext* subcontext, const std::string& prop_name) {
static bool enabled = GetBoolProperty("ro.actionable_compatible_property.enabled", false);
if (subcontext == nullptr || !enabled) {
return true;
}
static constexpr const char* kPartnerPrefixes[] = {
"init.svc.vendor.", "ro.vendor.", "persist.vendor.",
"vendor.", "init.svc.odm.", "ro.odm.",
"persist.odm.", "odm.", "ro.boot.",
};
for (const auto& prefix : kPartnerPrefixes) {
if (android::base::StartsWith(prop_name, prefix)) {
return true;
}
}
return CanReadProperty(subcontext->context(), prop_name);
}
Result<void> ParsePropertyTrigger(const std::string& trigger, Subcontext* subcontext,
std::map<std::string, std::string>* property_triggers) {
const static std::string prop_str("property:");
std::string prop_name(trigger.substr(prop_str.length()));
size_t equal_pos = prop_name.find('=');
if (equal_pos == std::string::npos) {
return Error() << "property trigger found without matching '='";
}
std::string prop_value(prop_name.substr(equal_pos + 1));
prop_name.erase(equal_pos);
if (!IsActionableProperty(subcontext, prop_name)) {
return Error() << "unexported property trigger found: " << prop_name;
}
if (auto [it, inserted] = property_triggers->emplace(prop_name, prop_value); !inserted) {
return Error() << "multiple property triggers found for same property";
}
return {};
}
Result<void> ValidateEventTrigger(const std::string& event_trigger) {
if (SelinuxGetVendorAndroidVersion() >= __ANDROID_API_R__) {
for (const char& c : event_trigger) {
if (c != '_' && c != '-' && !std::isalnum(c)) {
return Error() << "Illegal character '" << c << "' in '" << event_trigger << "'";
}
}
}
return {};
}
Result<void> ParseTriggers(const std::vector<std::string>& args, Subcontext* subcontext,
std::string* event_trigger,
std::map<std::string, std::string>* property_triggers) {
const static std::string prop_str("property:");
for (std::size_t i = 0; i < args.size(); ++i) {
if (args[i].empty()) {
return Error() << "empty trigger is not valid";
}
if (i % 2) {
if (args[i] != "&&") {
return Error() << "&& is the only symbol allowed to concatenate actions";
} else {
continue;
}
}
if (!args[i].compare(0, prop_str.length(), prop_str)) {
if (auto result = ParsePropertyTrigger(args[i], subcontext, property_triggers);
!result) {
return result;
}
} else {
if (!event_trigger->empty()) {
return Error() << "multiple event triggers are not allowed";
}
if (auto result = ValidateEventTrigger(args[i]); !result) {
return result;
}
*event_trigger = args[i];
}
}
return {};
}
} // namespace
Result<void> ActionParser::ParseSection(std::vector<std::string>&& args,
const std::string& filename, int line) {
std::vector<std::string> triggers(args.begin() + 1, args.end());
if (triggers.size() < 1) {
return Error() << "Actions must have a trigger";
}
Subcontext* action_subcontext = nullptr;
if (subcontext_ && subcontext_->PathMatchesSubcontext(filename)) {
action_subcontext = subcontext_;
}
std::string event_trigger;
std::map<std::string, std::string> property_triggers;
if (auto result = ParseTriggers(triggers, action_subcontext, &event_trigger, &property_triggers);
!result) {
return Error() << "ParseTriggers() failed: " << result.error();
}
auto action = std::make_unique<Action>(false, action_subcontext, filename, line, event_trigger,
property_triggers);
action_ = std::move(action);
return {};
}
Result<void> ActionParser::ParseLineSection(std::vector<std::string>&& args, int line) {
return action_ ? action_->AddCommand(std::move(args), line) : Result<void>{};
}
Result<void> ActionParser::EndSection() {
if (action_ && action_->NumCommands() > 0) {
action_manager_->AddAction(std::move(action_));
}
return {};
}
} // namespace init
} // namespace android