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 <xz.h>
20
21 #include <base/at_exit.h>
22 #include <base/command_line.h>
23 #include <base/logging.h>
24 #include <gflags/gflags.h>
25
26 #include "update_engine/common/daemon_base.h"
27 #include "update_engine/common/logging.h"
28 #include "update_engine/common/subprocess.h"
29 #include "update_engine/common/terminator.h"
30
31 using std::string;
32 DEFINE_bool(logtofile, false, "Write logs to a file in log_dir.");
33 DEFINE_bool(logtostderr,
34 false,
35 "Write logs to stderr instead of to a file in log_dir.");
36 DEFINE_bool(foreground, false, "Don't daemon()ize; run in foreground.");
37
main(int argc,char ** argv)38 int main(int argc, char** argv) {
39 chromeos_update_engine::Terminator::Init();
40 gflags::SetUsageMessage("A/B Update Engine");
41 gflags::ParseCommandLineFlags(&argc, &argv, true);
42
43 // We have two logging flags "--logtostderr" and "--logtofile"; and the logic
44 // to choose the logging destination is:
45 // 1. --logtostderr --logtofile -> logs to both
46 // 2. --logtostderr -> logs to system debug
47 // 3. --logtofile or no flags -> logs to file
48 bool log_to_system = FLAGS_logtostderr;
49 bool log_to_file = FLAGS_logtofile || !FLAGS_logtostderr;
50 chromeos_update_engine::SetupLogging(log_to_system, log_to_file);
51 if (!FLAGS_foreground)
52 PLOG_IF(FATAL, daemon(0, 0) == 1) << "daemon() failed";
53
54 LOG(INFO) << "A/B Update Engine starting";
55
56 // xz-embedded requires to initialize its CRC-32 table once on startup.
57 xz_crc32_init();
58
59 // Ensure that all written files have safe permissions.
60 // This is a mask, so we _block_ all permissions for the group owner and other
61 // users but allow all permissions for the user owner. We allow execution
62 // for the owner so we can create directories.
63 // Done _after_ log file creation.
64 umask(S_IRWXG | S_IRWXO);
65
66 auto daemon = chromeos_update_engine::DaemonBase::CreateInstance();
67 int exit_code = daemon->Run();
68
69 chromeos_update_engine::Subprocess::Get().FlushBufferedLogsAtExit();
70
71 LOG(INFO) << "A/B Update Engine terminating with exit code " << exit_code;
72 return exit_code;
73 }
74