apmanager: initial skeleton files.
BUG=chromium:423407
TEST=FEATURES=test emerge-$BOARD apmanager
USE='clang asan' FEATURES=test emerge-$BOARD apmanager
CQ-DEPEND=CL:223258, CL:223302
Change-Id: Ib42bd1eef4a9d6b0f30e085a64e9454c5b618d28
Reviewed-on: https://chromium-review.googlesource.com/223322
Reviewed-by: Peter Qiu <zqiu@chromium.org>
Commit-Queue: Peter Qiu <zqiu@chromium.org>
Tested-by: Peter Qiu <zqiu@chromium.org>
diff --git a/main.cc b/main.cc
new file mode 100644
index 0000000..41473a8
--- /dev/null
+++ b/main.cc
@@ -0,0 +1,122 @@
+// Copyright 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <vector>
+
+#include <base/bind.h>
+#include <base/command_line.h>
+#include <base/logging.h>
+#include <chromeos/minijail/minijail.h>
+#include <chromeos/syslog_logging.h>
+
+#include "apmanager/daemon.h"
+
+using std::vector;
+
+namespace {
+
+namespace switches {
+
+// Don't daemon()ize; run in foreground.
+const char kForeground[] = "foreground";
+// Flag that causes apmanager to show the help message and exit.
+const char kHelp[] = "help";
+
+// The help message shown if help flag is passed to the program.
+const char kHelpMessage[] = "\n"
+ "Available Switches: \n"
+ " --foreground\n"
+ " Don\'t daemon()ize; run in foreground.\n";
+} // namespace switches
+
+} // namespace
+
+namespace {
+
+const char kLoggerCommand[] = "/usr/bin/logger";
+const char kLoggerUser[] = "syslog";
+
+} // namespace
+
+// Always logs to the syslog and logs to stderr if
+// we are running in the foreground.
+void SetupLogging(chromeos::Minijail* minijail,
+ bool foreground,
+ const char* daemon_name) {
+ int log_flags = 0;
+ log_flags |= chromeos::kLogToSyslog;
+ log_flags |= chromeos::kLogHeader;
+ if (foreground) {
+ log_flags |= chromeos::kLogToStderr;
+ }
+ chromeos::InitLog(log_flags);
+
+ if (!foreground) {
+ vector<char*> logger_command_line;
+ int logger_stdin_fd;
+ logger_command_line.push_back(const_cast<char*>(kLoggerCommand));
+ logger_command_line.push_back(const_cast<char*>("--priority"));
+ logger_command_line.push_back(const_cast<char*>("daemon.err"));
+ logger_command_line.push_back(const_cast<char*>("--tag"));
+ logger_command_line.push_back(const_cast<char*>(daemon_name));
+ logger_command_line.push_back(nullptr);
+
+ struct minijail* jail = minijail->New();
+ minijail->DropRoot(jail, kLoggerUser, kLoggerUser);
+
+ if (!minijail->RunPipeAndDestroy(jail, logger_command_line,
+ nullptr, &logger_stdin_fd)) {
+ LOG(ERROR) << "Unable to spawn logger. "
+ << "Writes to stderr will be discarded.";
+ return;
+ }
+
+ // Note that we don't set O_CLOEXEC here. This means that stderr
+ // from any child processes will, by default, be logged to syslog.
+ if (dup2(logger_stdin_fd, fileno(stderr)) != fileno(stderr)) {
+ LOG(ERROR) << "Failed to redirect stderr to syslog: "
+ << strerror(errno);
+ }
+ close(logger_stdin_fd);
+ }
+}
+
+void DropPrivileges(chromeos::Minijail* minijail) {
+ struct minijail* jail = minijail->New();
+ minijail->DropRoot(jail, apmanager::Daemon::kAPManagerUserName,
+ apmanager::Daemon::kAPManagerGroupName);
+ minijail_enter(jail);
+ minijail->Destroy(jail);
+}
+
+void OnStartup(const char* daemon_name, CommandLine* cl) {
+ chromeos::Minijail* minijail = chromeos::Minijail::GetInstance();
+ SetupLogging(minijail, cl->HasSwitch(switches::kForeground), daemon_name);
+
+ LOG(INFO) << __func__ << ": Dropping privileges";
+
+ // Now that the daemon has all the resources it needs to run, we can drop
+ // privileges further.
+ DropPrivileges(minijail);
+}
+
+int main(int argc, char* argv[]) {
+ CommandLine::Init(argc, argv);
+ CommandLine* cl = CommandLine::ForCurrentProcess();
+
+ if (cl->HasSwitch(switches::kHelp)) {
+ LOG(INFO) << switches::kHelpMessage;
+ return 0;
+ }
+
+ const int nochdir = 0, noclose = 0;
+ if (!cl->HasSwitch(switches::kForeground))
+ PLOG_IF(FATAL, daemon(nochdir, noclose) == -1) << "Failed to daemonize";
+
+ apmanager::Daemon daemon(base::Bind(&OnStartup, argv[0], cl));
+
+ daemon.Run();
+
+ return 0;
+}