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 <sys/stat.h>
18 #include <sys/types.h>
19 #include <unistd.h>
20 #include <xz.h>
21
22 #include <string>
23
24 #include <base/at_exit.h>
25 #include <base/command_line.h>
26 #include <base/files/file_util.h>
27 #include <base/logging.h>
28 #include <base/strings/string_util.h>
29 #include <base/strings/stringprintf.h>
30 #include <brillo/flag_helper.h>
31
32 #include "update_engine/common/terminator.h"
33 #include "update_engine/common/utils.h"
34 #include "update_engine/daemon.h"
35
36 using std::string;
37
38 namespace chromeos_update_engine {
39 namespace {
40
SetupLogSymlink(const string & symlink_path,const string & log_path)41 void SetupLogSymlink(const string& symlink_path, const string& log_path) {
42 // TODO(petkov): To ensure a smooth transition between non-timestamped and
43 // timestamped logs, move an existing log to start the first timestamped
44 // one. This code can go away once all clients are switched to this version or
45 // we stop caring about the old-style logs.
46 if (utils::FileExists(symlink_path.c_str()) &&
47 !utils::IsSymlink(symlink_path.c_str())) {
48 base::ReplaceFile(base::FilePath(symlink_path),
49 base::FilePath(log_path),
50 nullptr);
51 }
52 base::DeleteFile(base::FilePath(symlink_path), true);
53 if (symlink(log_path.c_str(), symlink_path.c_str()) == -1) {
54 PLOG(ERROR) << "Unable to create symlink " << symlink_path
55 << " pointing at " << log_path;
56 }
57 }
58
GetTimeAsString(time_t utime)59 string GetTimeAsString(time_t utime) {
60 struct tm tm;
61 CHECK_EQ(localtime_r(&utime, &tm), &tm);
62 char str[16];
63 CHECK_EQ(strftime(str, sizeof(str), "%Y%m%d-%H%M%S", &tm), 15u);
64 return str;
65 }
66
SetupLogFile(const string & kLogsRoot)67 string SetupLogFile(const string& kLogsRoot) {
68 const string kLogSymlink = kLogsRoot + "/update_engine.log";
69 const string kLogsDir = kLogsRoot + "/update_engine";
70 const string kLogPath =
71 base::StringPrintf("%s/update_engine.%s",
72 kLogsDir.c_str(),
73 GetTimeAsString(::time(nullptr)).c_str());
74 mkdir(kLogsDir.c_str(), 0755);
75 SetupLogSymlink(kLogSymlink, kLogPath);
76 return kLogSymlink;
77 }
78
SetupLogging(bool log_to_std_err)79 void SetupLogging(bool log_to_std_err) {
80 string log_file;
81 logging::LoggingSettings log_settings;
82 log_settings.lock_log = logging::DONT_LOCK_LOG_FILE;
83 log_settings.delete_old = logging::APPEND_TO_OLD_LOG_FILE;
84
85 if (log_to_std_err) {
86 // Log to stderr initially.
87 log_settings.log_file = nullptr;
88 log_settings.logging_dest = logging::LOG_TO_SYSTEM_DEBUG_LOG;
89 } else {
90 log_file = SetupLogFile("/var/log");
91 log_settings.log_file = log_file.c_str();
92 log_settings.logging_dest = logging::LOG_TO_FILE;
93 }
94
95 logging::InitLogging(log_settings);
96 }
97
98 } // namespace
99 } // namespace chromeos_update_engine
100
main(int argc,char ** argv)101 int main(int argc, char** argv) {
102 DEFINE_bool(logtostderr, false,
103 "Write logs to stderr instead of to a file in log_dir.");
104 DEFINE_bool(foreground, false,
105 "Don't daemon()ize; run in foreground.");
106
107 chromeos_update_engine::Terminator::Init();
108 brillo::FlagHelper::Init(argc, argv, "Chromium OS Update Engine");
109 chromeos_update_engine::SetupLogging(FLAGS_logtostderr);
110 if (!FLAGS_foreground)
111 PLOG_IF(FATAL, daemon(0, 0) == 1) << "daemon() failed";
112
113 LOG(INFO) << "Chrome OS Update Engine starting";
114
115 // xz-embedded requires to initialize its CRC-32 table once on startup.
116 xz_crc32_init();
117
118 // Ensure that all written files have safe permissions.
119 // This is a mask, so we _block_ all permissions for the group owner and other
120 // users but allow all permissions for the user owner. We allow execution
121 // for the owner so we can create directories.
122 // Done _after_ log file creation.
123 umask(S_IRWXG | S_IRWXO);
124
125 chromeos_update_engine::UpdateEngineDaemon update_engine_daemon;
126 int exit_code = update_engine_daemon.Run();
127
128 LOG(INFO) << "Chrome OS Update Engine terminating with exit code "
129 << exit_code;
130 return exit_code;
131 }
132