1/*
2 * Copyright (C) 2010 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 "parser.h"
18
19#include <dirent.h>
20
21#include <android-base/chrono_utils.h>
22#include <android-base/logging.h>
23#include <android-base/stringprintf.h>
24#include <android-base/strings.h>
25
26#include "tokenizer.h"
27#include "util.h"
28
29namespace android {
30namespace init {
31
32Parser::Parser() {}
33
34void Parser::AddSectionParser(const std::string& name, std::unique_ptr<SectionParser> parser) {
35    section_parsers_[name] = std::move(parser);
36}
37
38void Parser::AddSingleLineParser(const std::string& prefix, LineCallback callback) {
39    line_callbacks_.emplace_back(prefix, callback);
40}
41
42void Parser::ParseData(const std::string& filename, const std::string& data, size_t* parse_errors) {
43    // TODO: Use a parser with const input and remove this copy
44    std::vector<char> data_copy(data.begin(), data.end());
45    data_copy.push_back('\0');
46
47    parse_state state;
48    state.line = 0;
49    state.ptr = &data_copy[0];
50    state.nexttoken = 0;
51
52    SectionParser* section_parser = nullptr;
53    int section_start_line = -1;
54    std::vector<std::string> args;
55
56    auto end_section = [&] {
57        if (section_parser == nullptr) return;
58
59        if (auto result = section_parser->EndSection(); !result) {
60            (*parse_errors)++;
61            LOG(ERROR) << filename << ": " << section_start_line << ": " << result.error();
62        }
63
64        section_parser = nullptr;
65        section_start_line = -1;
66    };
67
68    for (;;) {
69        switch (next_token(&state)) {
70            case T_EOF:
71                end_section();
72                return;
73            case T_NEWLINE:
74                state.line++;
75                if (args.empty()) break;
76                // If we have a line matching a prefix we recognize, call its callback and unset any
77                // current section parsers.  This is meant for /sys/ and /dev/ line entries for
78                // uevent.
79                for (const auto& [prefix, callback] : line_callbacks_) {
80                    if (android::base::StartsWith(args[0], prefix)) {
81                        end_section();
82
83                        if (auto result = callback(std::move(args)); !result) {
84                            (*parse_errors)++;
85                            LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
86                        }
87                        break;
88                    }
89                }
90                if (section_parsers_.count(args[0])) {
91                    end_section();
92                    section_parser = section_parsers_[args[0]].get();
93                    section_start_line = state.line;
94                    if (auto result =
95                            section_parser->ParseSection(std::move(args), filename, state.line);
96                        !result) {
97                        (*parse_errors)++;
98                        LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
99                        section_parser = nullptr;
100                    }
101                } else if (section_parser) {
102                    if (auto result = section_parser->ParseLineSection(std::move(args), state.line);
103                        !result) {
104                        (*parse_errors)++;
105                        LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
106                    }
107                }
108                args.clear();
109                break;
110            case T_TEXT:
111                args.emplace_back(state.text);
112                break;
113        }
114    }
115}
116
117bool Parser::ParseConfigFile(const std::string& path, size_t* parse_errors) {
118    LOG(INFO) << "Parsing file " << path << "...";
119    android::base::Timer t;
120    auto config_contents = ReadFile(path);
121    if (!config_contents) {
122        LOG(ERROR) << "Unable to read config file '" << path << "': " << config_contents.error();
123        return false;
124    }
125
126    config_contents->push_back('\n');  // TODO: fix parse_config.
127    ParseData(path, *config_contents, parse_errors);
128    for (const auto& [section_name, section_parser] : section_parsers_) {
129        section_parser->EndFile();
130    }
131
132    LOG(VERBOSE) << "(Parsing " << path << " took " << t << ".)";
133    return true;
134}
135
136bool Parser::ParseConfigDir(const std::string& path, size_t* parse_errors) {
137    LOG(INFO) << "Parsing directory " << path << "...";
138    std::unique_ptr<DIR, decltype(&closedir)> config_dir(opendir(path.c_str()), closedir);
139    if (!config_dir) {
140        PLOG(ERROR) << "Could not import directory '" << path << "'";
141        return false;
142    }
143    dirent* current_file;
144    std::vector<std::string> files;
145    while ((current_file = readdir(config_dir.get()))) {
146        // Ignore directories and only process regular files.
147        if (current_file->d_type == DT_REG) {
148            std::string current_path =
149                android::base::StringPrintf("%s/%s", path.c_str(), current_file->d_name);
150            files.emplace_back(current_path);
151        }
152    }
153    // Sort first so we load files in a consistent order (bug 31996208)
154    std::sort(files.begin(), files.end());
155    for (const auto& file : files) {
156        if (!ParseConfigFile(file, parse_errors)) {
157            LOG(ERROR) << "could not import file '" << file << "'";
158        }
159    }
160    return true;
161}
162
163bool Parser::ParseConfig(const std::string& path) {
164    size_t parse_errors;
165    return ParseConfig(path, &parse_errors);
166}
167
168bool Parser::ParseConfig(const std::string& path, size_t* parse_errors) {
169    *parse_errors = 0;
170    if (is_dir(path.c_str())) {
171        return ParseConfigDir(path, parse_errors);
172    }
173    return ParseConfigFile(path, parse_errors);
174}
175
176}  // namespace init
177}  // namespace android
178