1/*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "action_parser.h"
18
19#include <android-base/strings.h>
20
21#include "stable_properties.h"
22
23#if defined(__ANDROID__)
24#include <android-base/properties.h>
25#else
26#include "host_init_stubs.h"
27#endif
28
29using android::base::GetBoolProperty;
30using android::base::StartsWith;
31
32namespace android {
33namespace init {
34
35namespace {
36
37bool IsActionableProperty(Subcontext* subcontext, const std::string& prop_name) {
38    static bool enabled = GetBoolProperty("ro.actionable_compatible_property.enabled", false);
39
40    if (subcontext == nullptr || !enabled) {
41        return true;
42    }
43
44    if (kExportedActionableProperties.count(prop_name) == 1) {
45        return true;
46    }
47    for (const auto& prefix : kPartnerPrefixes) {
48        if (android::base::StartsWith(prop_name, prefix)) {
49            return true;
50        }
51    }
52    return false;
53}
54
55Result<Success> ParsePropertyTrigger(const std::string& trigger, Subcontext* subcontext,
56                                     std::map<std::string, std::string>* property_triggers) {
57    const static std::string prop_str("property:");
58    std::string prop_name(trigger.substr(prop_str.length()));
59    size_t equal_pos = prop_name.find('=');
60    if (equal_pos == std::string::npos) {
61        return Error() << "property trigger found without matching '='";
62    }
63
64    std::string prop_value(prop_name.substr(equal_pos + 1));
65    prop_name.erase(equal_pos);
66
67    if (!IsActionableProperty(subcontext, prop_name)) {
68        return Error() << "unexported property tigger found: " << prop_name;
69    }
70
71    if (auto [it, inserted] = property_triggers->emplace(prop_name, prop_value); !inserted) {
72        return Error() << "multiple property triggers found for same property";
73    }
74    return Success();
75}
76
77Result<Success> ParseTriggers(const std::vector<std::string>& args, Subcontext* subcontext,
78                              std::string* event_trigger,
79                              std::map<std::string, std::string>* property_triggers) {
80    const static std::string prop_str("property:");
81    for (std::size_t i = 0; i < args.size(); ++i) {
82        if (args[i].empty()) {
83            return Error() << "empty trigger is not valid";
84        }
85
86        if (i % 2) {
87            if (args[i] != "&&") {
88                return Error() << "&& is the only symbol allowed to concatenate actions";
89            } else {
90                continue;
91            }
92        }
93
94        if (!args[i].compare(0, prop_str.length(), prop_str)) {
95            if (auto result = ParsePropertyTrigger(args[i], subcontext, property_triggers);
96                !result) {
97                return result;
98            }
99        } else {
100            if (!event_trigger->empty()) {
101                return Error() << "multiple event triggers are not allowed";
102            }
103
104            *event_trigger = args[i];
105        }
106    }
107
108    return Success();
109}
110
111}  // namespace
112
113Result<Success> ActionParser::ParseSection(std::vector<std::string>&& args,
114                                           const std::string& filename, int line) {
115    std::vector<std::string> triggers(args.begin() + 1, args.end());
116    if (triggers.size() < 1) {
117        return Error() << "Actions must have a trigger";
118    }
119
120    Subcontext* action_subcontext = nullptr;
121    if (subcontexts_) {
122        for (auto& subcontext : *subcontexts_) {
123            if (StartsWith(filename, subcontext.path_prefix())) {
124                action_subcontext = &subcontext;
125                break;
126            }
127        }
128    }
129
130    std::string event_trigger;
131    std::map<std::string, std::string> property_triggers;
132
133    if (auto result = ParseTriggers(triggers, action_subcontext, &event_trigger, &property_triggers);
134        !result) {
135        return Error() << "ParseTriggers() failed: " << result.error();
136    }
137
138    auto action = std::make_unique<Action>(false, action_subcontext, filename, line, event_trigger,
139                                           property_triggers);
140
141    action_ = std::move(action);
142    return Success();
143}
144
145Result<Success> ActionParser::ParseLineSection(std::vector<std::string>&& args, int line) {
146    return action_ ? action_->AddCommand(std::move(args), line) : Success();
147}
148
149Result<Success> ActionParser::EndSection() {
150    if (action_ && action_->NumCommands() > 0) {
151        action_manager_->AddAction(std::move(action_));
152    }
153
154    return Success();
155}
156
157}  // namespace init
158}  // namespace android
159