1 // 2 // Copyright (C) 2012 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 <inttypes.h> 18 #include <sys/stat.h> 19 #include <sys/types.h> 20 #include <unistd.h> 21 #include <xz.h> 22 23 #include <algorithm> 24 #include <string> 25 #include <vector> 26 27 #include <base/at_exit.h> 28 #include <base/command_line.h> 29 #include <base/files/dir_reader_posix.h> 30 #include <base/files/file_util.h> 31 #include <base/logging.h> 32 #include <base/strings/string_util.h> 33 #include <base/strings/stringprintf.h> 34 #include <brillo/flag_helper.h> 35 36 #include "update_engine/common/terminator.h" 37 #include "update_engine/common/utils.h" 38 #include "update_engine/daemon.h" 39 40 using std::string; 41 42 namespace chromeos_update_engine { 43 namespace { 44 45 string GetTimeAsString(time_t utime) { 46 struct tm tm; 47 CHECK_EQ(localtime_r(&utime, &tm), &tm); 48 char str[16]; 49 CHECK_EQ(strftime(str, sizeof(str), "%Y%m%d-%H%M%S", &tm), 15u); 50 return str; 51 } 52 53 #ifdef __ANDROID__ 54 constexpr char kSystemLogsRoot[] = "/data/misc/update_engine_log"; 55 constexpr size_t kLogCount = 5; 56 57 // Keep the most recent |kLogCount| logs but remove the old ones in 58 // "/data/misc/update_engine_log/". 59 void DeleteOldLogs(const string& kLogsRoot) { 60 base::DirReaderPosix reader(kLogsRoot.c_str()); 61 if (!reader.IsValid()) { 62 LOG(ERROR) << "Failed to read " << kLogsRoot; 63 return; 64 } 65 66 std::vector<string> old_logs; 67 while (reader.Next()) { 68 if (reader.name()[0] == '.') 69 continue; 70 71 // Log files are in format "update_engine.%Y%m%d-%H%M%S", 72 // e.g. update_engine.20090103-231425 73 uint64_t date; 74 uint64_t local_time; 75 if (sscanf(reader.name(), 76 "update_engine.%" PRIu64 "-%" PRIu64 "", 77 &date, 78 &local_time) == 2) { 79 old_logs.push_back(reader.name()); 80 } else { 81 LOG(WARNING) << "Unrecognized log file " << reader.name(); 82 } 83 } 84 85 std::sort(old_logs.begin(), old_logs.end(), std::greater<string>()); 86 for (size_t i = kLogCount; i < old_logs.size(); i++) { 87 string log_path = kLogsRoot + "/" + old_logs[i]; 88 if (unlink(log_path.c_str()) == -1) { 89 PLOG(WARNING) << "Failed to unlink " << log_path; 90 } 91 } 92 } 93 94 string SetupLogFile(const string& kLogsRoot) { 95 DeleteOldLogs(kLogsRoot); 96 97 return base::StringPrintf("%s/update_engine.%s", 98 kLogsRoot.c_str(), 99 GetTimeAsString(::time(nullptr)).c_str()); 100 } 101 #else 102 constexpr char kSystemLogsRoot[] = "/var/log"; 103 104 void SetupLogSymlink(const string& symlink_path, const string& log_path) { 105 // TODO(petkov): To ensure a smooth transition between non-timestamped and 106 // timestamped logs, move an existing log to start the first timestamped 107 // one. This code can go away once all clients are switched to this version or 108 // we stop caring about the old-style logs. 109 if (utils::FileExists(symlink_path.c_str()) && 110 !utils::IsSymlink(symlink_path.c_str())) { 111 base::ReplaceFile(base::FilePath(symlink_path), 112 base::FilePath(log_path), 113 nullptr); 114 } 115 base::DeleteFile(base::FilePath(symlink_path), true); 116 if (symlink(log_path.c_str(), symlink_path.c_str()) == -1) { 117 PLOG(ERROR) << "Unable to create symlink " << symlink_path 118 << " pointing at " << log_path; 119 } 120 } 121 122 string SetupLogFile(const string& kLogsRoot) { 123 const string kLogSymlink = kLogsRoot + "/update_engine.log"; 124 const string kLogsDir = kLogsRoot + "/update_engine"; 125 const string kLogPath = 126 base::StringPrintf("%s/update_engine.%s", 127 kLogsDir.c_str(), 128 GetTimeAsString(::time(nullptr)).c_str()); 129 mkdir(kLogsDir.c_str(), 0755); 130 SetupLogSymlink(kLogSymlink, kLogPath); 131 return kLogSymlink; 132 } 133 #endif // __ANDROID__ 134 135 void SetupLogging(bool log_to_system, bool log_to_file) { 136 logging::LoggingSettings log_settings; 137 log_settings.lock_log = logging::DONT_LOCK_LOG_FILE; 138 log_settings.logging_dest = static_cast<logging::LoggingDestination>( 139 (log_to_system ? logging::LOG_TO_SYSTEM_DEBUG_LOG : 0) | 140 (log_to_file ? logging::LOG_TO_FILE : 0)); 141 log_settings.log_file = nullptr; 142 143 string log_file; 144 if (log_to_file) { 145 log_file = SetupLogFile(kSystemLogsRoot); 146 log_settings.delete_old = logging::APPEND_TO_OLD_LOG_FILE; 147 log_settings.log_file = log_file.c_str(); 148 } 149 logging::InitLogging(log_settings); 150 151 #ifdef __ANDROID__ 152 // The log file will have AID_LOG as group ID; this GID is inherited from the 153 // parent directory "/data/misc/update_engine_log" which sets the SGID bit. 154 chmod(log_file.c_str(), 0640); 155 #endif 156 } 157 158 } // namespace 159 } // namespace chromeos_update_engine 160 161 int main(int argc, char** argv) { 162 DEFINE_bool(logtofile, false, "Write logs to a file in log_dir."); 163 DEFINE_bool(logtostderr, false, 164 "Write logs to stderr instead of to a file in log_dir."); 165 DEFINE_bool(foreground, false, 166 "Don't daemon()ize; run in foreground."); 167 168 chromeos_update_engine::Terminator::Init(); 169 brillo::FlagHelper::Init(argc, argv, "Chromium OS Update Engine"); 170 171 // We have two logging flags "--logtostderr" and "--logtofile"; and the logic 172 // to choose the logging destination is: 173 // 1. --logtostderr --logtofile -> logs to both 174 // 2. --logtostderr -> logs to system debug 175 // 3. --logtofile or no flags -> logs to file 176 bool log_to_system = FLAGS_logtostderr; 177 bool log_to_file = FLAGS_logtofile || !FLAGS_logtostderr; 178 chromeos_update_engine::SetupLogging(log_to_system, log_to_file); 179 if (!FLAGS_foreground) 180 PLOG_IF(FATAL, daemon(0, 0) == 1) << "daemon() failed"; 181 182 LOG(INFO) << "Chrome OS Update Engine starting"; 183 184 // xz-embedded requires to initialize its CRC-32 table once on startup. 185 xz_crc32_init(); 186 187 // Ensure that all written files have safe permissions. 188 // This is a mask, so we _block_ all permissions for the group owner and other 189 // users but allow all permissions for the user owner. We allow execution 190 // for the owner so we can create directories. 191 // Done _after_ log file creation. 192 umask(S_IRWXG | S_IRWXO); 193 194 chromeos_update_engine::UpdateEngineDaemon update_engine_daemon; 195 int exit_code = update_engine_daemon.Run(); 196 197 LOG(INFO) << "Chrome OS Update Engine terminating with exit code " 198 << exit_code; 199 return exit_code; 200 } 201
