blob: 53b6eeb9fb0a9173fbf90bc7b517f0f3421e5cb2 [file] [log] [blame]
// Copyright (c) 2013 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 <errno.h>
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include <string>
#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 "lorgnette/daemon.h"
using std::string;
using std::vector;
namespace switches {
// Don't daemon()ize; run in foreground.
static const char kForeground[] = "foreground";
// Flag that causes lorgnette to show the help message and exit.
static const char kHelp[] = "help";
// The help message shown if help flag is passed to the program.
static const char kHelpMessage[] = "\n"
"Available Switches: \n"
" --foreground\n"
" Don\'t daemon()ize; run in foreground.\n";
} // namespace switches
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;
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));
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.";
// 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);
// Enter a sanboxed vfs namespace.
void EnterVFSNamespace(chromeos::Minijail *minijail) {
struct minijail *jail = minijail->New();
void DropPrivileges(chromeos::Minijail *minijail) {
struct minijail *jail = minijail->New();
minijail->DropRoot(jail, lorgnette::Daemon::kScanUserName,
void OnStartup(const char *daemon_name, base::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.
int main(int argc, char **argv) {
base::CommandLine::Init(argc, argv);
base::CommandLine *cl = base::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";
lorgnette::Daemon daemon(base::Bind(&OnStartup, argv[0], cl));
return 0;