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dinit.cc
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dinit.cc
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#include <iostream>
#include <fstream>
#include <list>
#include <cstring>
#include <csignal>
#include <cstddef>
#include <cstdlib>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <sys/socket.h>
#include <unistd.h>
#include <fcntl.h>
#include <pwd.h>
#include <termios.h>
#ifdef __linux__
#include <sys/prctl.h>
#include <sys/klog.h>
#include <sys/reboot.h>
#endif
#if defined(__FreeBSD__) || defined(__DragonFly__)
#include <sys/procctl.h>
#endif
#include <dasynq.h>
#include "dinit.h"
#include "service.h"
#include "control.h"
#include "dinit-log.h"
#include "dinit-socket.h"
#include "static-string.h"
#include "dinit-utmp.h"
#include "dinit-env.h"
#include "options-processing.h"
#include "mconfig.h"
/*
* When running as the system init process, Dinit processes the following signals:
*
* SIGTERM - roll back services and then fork/exec /sbin/halt
* SIGINT - roll back services and then fork/exec /sbin/reboot
* SIGQUIT - exec() /sbin/shutdown without rolling back services
*
* It's an open question about whether Dinit should roll back services *before*
* running halt/reboot, since those commands should prompt rollback of services
* anyway. But it seems safe to do so, and it means the user can at least stop
* services even if the halt/reboot commands are unavailable for some reason.
*/
using namespace cts;
using eventloop_t = dasynq::event_loop<dasynq::null_mutex>;
eventloop_t event_loop(dasynq::delayed_init {});
static void sigint_reboot_cb(eventloop_t &eloop) noexcept;
static void sigquit_cb(eventloop_t &eloop) noexcept;
static void sigterm_cb(eventloop_t &eloop) noexcept;
static bool open_control_socket(bool report_ro_failure = true) noexcept;
static void close_control_socket() noexcept;
static void control_socket_ready() noexcept;
static void confirm_restart_boot() noexcept;
static void flush_log() noexcept;
static void control_socket_cb(eventloop_t *loop, int fd) noexcept;
#ifdef SUPPORT_CGROUPS
static void find_cgroup_path() noexcept;
#endif
static void printVersion();
// Variables
static dirload_service_set *services;
static bool am_system_mgr = false; // true if we are PID 1
static bool am_system_init = false; // true if we are the system init process
static bool auto_recovery = false; // automatically run recovery service on boot failure
static bool did_log_boot = false;
static bool control_socket_open = false;
bool external_log_open = false;
int active_control_conns = 0;
int socket_ready_fd = -1;
sigset_t orig_signal_mask; // signal mask when started
// Control socket path. We maintain a string (control_socket_str) in case we need
// to allocate storage, but control_socket_path is the authoritative value.
static const char *control_socket_path = SYSCONTROLSOCKET;
static std::string control_socket_str;
static const char *env_file_path = "/etc/dinit/environment";
static const char *log_path = "/dev/log";
static bool log_is_syslog = true; // if false, log is a file
// Set to true (when console_input_watcher is active) if console input becomes available
static bool console_input_ready = false;
#ifdef SUPPORT_CGROUPS
// Path of the root cgroup according to dinit. This will be dinit's own cgroup path.
std::string cgroups_path;
bool have_cgroups_path = false;
#endif
namespace {
// Event-loop handler for a signal, which just delegates to a function (pointer).
class callback_signal_handler : public eventloop_t::signal_watcher_impl<callback_signal_handler>
{
using rearm = dasynq::rearm;
public:
typedef void (*cb_func_t)(eventloop_t &);
private:
cb_func_t cb_func;
public:
callback_signal_handler() : cb_func(nullptr) { }
callback_signal_handler(cb_func_t pcb_func) : cb_func(pcb_func) { }
void set_cb_func(cb_func_t cb_func)
{
this->cb_func = cb_func;
}
rearm received(eventloop_t &eloop, int signo, siginfo_p siginfo)
{
cb_func(eloop);
return rearm::REARM;
}
};
// Event-loop handler for when a connection is made to the control socket.
class control_socket_watcher : public eventloop_t::fd_watcher_impl<control_socket_watcher>
{
using rearm = dasynq::rearm;
public:
rearm fd_event(eventloop_t &loop, int fd, int flags) noexcept
{
control_socket_cb(&loop, fd);
return rearm::REARM;
}
};
// Watch for console input and set a flag when it is available.
class console_input_watcher : public eventloop_t::fd_watcher_impl<console_input_watcher>
{
using rearm = dasynq::rearm;
public:
rearm fd_event(eventloop_t &loop, int fd, int flags) noexcept
{
console_input_ready = true;
return rearm::DISARM;
}
};
// Simple timer used to limit the amount of time waiting for the log flush to complete (at shutdown)
class log_flush_timer_t : public eventloop_t::timer_impl<log_flush_timer_t>
{
using rearm = dasynq::rearm;
bool expired;
public:
rearm timer_expiry(eventloop_t &, int expiry_count)
{
expired = true;
return rearm::DISARM;
}
bool has_expired()
{
return expired;
}
void reset()
{
expired = false;
}
};
control_socket_watcher control_socket_io;
console_input_watcher console_input_io;
log_flush_timer_t log_flush_timer;
// These need to be at namespace scope to prevent causing stack allocations when using them:
constexpr auto shutdown_exec = literal(SBINDIR) + "/" + SHUTDOWN_PREFIX + "shutdown";
constexpr auto dinit_exec = literal(SBINDIR) + "/" + "dinit";
constexpr auto error_exec_sd = literal("Error executing ") + shutdown_exec + ": ";
constexpr auto error_exec_dinit = literal("Error executing ") + dinit_exec + ": ";
}
// Options handled in dinit_main
struct options {
const char * env_file = nullptr;
bool control_socket_path_set = false;
bool env_file_set = false;
bool log_specified = false;
bool process_sys_args = false;
service_dir_opt service_dir_opts;
// list of services to start
std::list<const char *> services_to_start;
};
// Process a command line argument (and possibly its follow-up value)
// Returns -1 for clean exit required, 0 for success, 1 for error exit required
static int process_commandline_arg(char **argv, int argc, int &i, options &opts)
{
using std::cerr;
using std::cout;
using std::endl;
using std::list;
const char * &env_file = opts.env_file;
bool &control_socket_path_set = opts.control_socket_path_set;
bool &env_file_set = opts.env_file_set;
bool &log_specified = opts.log_specified;
service_dir_opt &service_dir_opts = opts.service_dir_opts;
list<const char *> &services_to_start = opts.services_to_start;
auto arg_to_loglevel = [&](const char *option_name, loglevel_t &wanted_level) {
if (++i < argc && argv[i][0] != '\0') {
if (strcmp(argv[i], "none") == 0) {
wanted_level = loglevel_t::ZERO;
}
else if (strcmp(argv[i], "error") == 0) {
wanted_level = loglevel_t::ERROR;
}
else if (strcmp(argv[i], "warn") == 0) {
wanted_level = loglevel_t::WARN;
}
else if (strcmp(argv[i], "info") == 0) {
wanted_level = loglevel_t::NOTICE;
}
else if (strcmp(argv[i], "debug") == 0) {
wanted_level = loglevel_t::DEBUG;
}
else {
cerr << "dinit: '" << option_name << "' accepts only arguments: 'none', 'error', 'warn', 'info', 'debug'\n";
return false;
}
return true;
}
else {
cerr << "dinit: '" << option_name << "' requires an argument\n";
return false;
}
};
if (argv[i][0] == '-') {
// An option...
if (strcmp(argv[i], "--env-file") == 0 || strcmp(argv[i], "-e") == 0) {
if (++i < argc && argv[i][0] != '\0') {
env_file_set = true;
env_file = argv[i];
}
else {
cerr << "dinit: '--env-file' (-e) requires an argument\n";
return 1;
}
}
else if (strcmp(argv[i], "--services-dir") == 0 || strcmp(argv[i], "-d") == 0) {
if (++i < argc && argv[i][0] != '\0') {
service_dir_opts.set_specified_service_dir(argv[i]);
}
else {
cerr << "dinit: '--services-dir' (-d) requires an argument\n";
return 1;
}
}
else if (strcmp(argv[i], "--system") == 0 || strcmp(argv[i], "-s") == 0) {
am_system_init = true;
}
else if (strcmp(argv[i], "--system-mgr") == 0 || strcmp(argv[i], "-m") == 0) {
am_system_mgr = true;
opts.process_sys_args = false;
}
else if (strcmp(argv[i], "--user") == 0 || strcmp(argv[i], "-u") == 0) {
am_system_init = false;
}
else if (strcmp(argv[i], "--container") == 0 || strcmp(argv[i], "-o") == 0) {
am_system_mgr = false;
opts.process_sys_args = false;
}
else if (strcmp(argv[i], "--auto-recovery") == 0 || strcmp(argv[i], "-r") == 0) {
auto_recovery = true;
}
else if (strcmp(argv[i], "--socket-path") == 0 || strcmp(argv[i], "-p") == 0) {
if (++i < argc && argv[i][0] != '\0') {
control_socket_path = argv[i];
control_socket_path_set = true;
}
else {
cerr << "dinit: '--socket-path' (-p) requires an argument\n";
return 1;
}
}
else if (strcmp(argv[i], "--ready-fd") == 0 || strcmp(argv[i], "-F") == 0) {
if (++i < argc) {
char *endp = nullptr;
auto fdn = strtoul(argv[i], &endp, 10);
if (endp == argv[i] || *endp) {
cerr << "dinit: '--ready-fd' (-F) requires a numerical argument\n";
return 1;
}
socket_ready_fd = int(fdn);
auto fl = fcntl(socket_ready_fd, F_GETFD);
// We also want to make sure stdin is not allowed
if (socket_ready_fd == 0 || fl < 0) {
cerr << "dinit: '--ready-fd' (-F) requires an open file descriptor\n";
return 1;
}
// Leave standard file descriptors alone, but make sure
// anything else is not leaked to child processes
if (socket_ready_fd > 2) {
fcntl(socket_ready_fd, F_SETFD, FD_CLOEXEC | fl);
}
}
else {
cerr << "dinit: '--ready-fd' (-F) requires an argument\n";
return 1;
}
}
else if (strcmp(argv[i], "--log-file") == 0 || strcmp(argv[i], "-l") == 0) {
if (++i < argc && argv[i][0] != '\0') {
log_path = argv[i];
log_is_syslog = false;
log_specified = true;
}
else {
cerr << "dinit: '--log-file' (-l) requires an argument\n";
return 1;
}
}
else if (strcmp(argv[i], "--quiet") == 0 || strcmp(argv[i], "-q") == 0) {
console_service_status = false;
log_level[DLOG_CONS] = loglevel_t::ZERO;
}
else if (strcmp(argv[i], "--console-level") == 0) {
loglevel_t wanted_level;
if (!arg_to_loglevel("--console-level", wanted_level)) return 1;
log_level[DLOG_CONS] = wanted_level;
}
else if (strcmp(argv[i], "--log-level") == 0) {
loglevel_t wanted_level;
if (!arg_to_loglevel("--log-level", wanted_level)) return 1;
log_level[DLOG_MAIN] = wanted_level;
}
#ifdef SUPPORT_CGROUPS
else if (strcmp(argv[i], "--cgroup-path") == 0 || strcmp(argv[i], "-b") == 0) {
if (++i < argc && argv[i][0] != '\0') {
cgroups_path = argv[i];
have_cgroups_path = true;
}
else {
cerr << "dinit: '--cgroup-path' (-b) requires an argument\n";
return 1;
}
}
#endif
else if (strcmp(argv[i], "--service") == 0 || strcmp(argv[i], "-t") == 0) {
if (++i < argc && argv[i][0] != '\0') {
services_to_start.push_back(argv[i]);
}
else {
cerr << "dinit: '--service' (-t) requires an argument\n";
return 1;
}
}
else if (strcmp(argv[i], "--version") == 0) {
printVersion();
return -1;
}
else if (strcmp(argv[i], "--help") == 0) {
cout << "dinit: init/service manager daemon\n"
" --help display (this) help\n"
" --version display version\n"
" --env-file <file>, -e <file>\n"
" environment variable initialisation file\n"
" --services-dir <dir>, -d <dir>\n"
" set base directory for service description\n"
" files, can be specified multiple times\n"
" --system, -s run as the system service manager\n"
" --system-mgr, -m run as system manager (perform shutdown etc)\n"
" --user, -u run as a user service manager\n"
" --container, -o run in container mode (do not manage system)\n"
" --auto-recovery, -r auto-run recovery service on system manager boot failure\n"
" --socket-path <path>, -p <path>\n"
" path to control socket\n"
" --ready-fd <fd>, -F <fd>\n"
" file descriptor to report readiness\n"
#ifdef SUPPORT_CGROUPS
" --cgroup-path <path>, -b <path>\n"
" cgroup base path (for resolving relative paths)\n"
#endif
" --log-file <file>, -l <file> log to the specified file\n"
" --quiet, -q disable output to standard output\n"
" <service-name>, --service <service-name>, -t <service-name>\n"
" start service with name <service-name>\n";
return -1;
}
else {
// unrecognized
if (!opts.process_sys_args) {
cerr << "dinit: unrecognized option: " << argv[i] << endl;
return 1;
}
}
}
else {
if (argv[i][0] == '\0') {
cerr << "dinit: error: empty command-line argument\n";
return 1;
}
#ifdef __linux__
// If we are running as init (PID=1), the Linux kernel gives us all command line arguments it was
// given but didn't recognize, and, uh, *some* that it did recognize, which means we can't assume
// that anything is a service name (for example "nopti" seems to get passed through to init).
// However, we can look for special names that we know aren't kernel parameters, such as "single".
//
// (Note this may have been fixed in recent kernels: see changelog for 5.15.46/5.18.3,
// "x86: Fix return value of __setup handlers")
//
// LILO puts "auto" on the command line for unattended boots, but we don't care about that and want
// it filtered.
//
// We don't expect to see options beginning with '-' appear on the kernel command line either, so we
// can interpret those as dinit arguments. In particular if we see -m or -o, we assume that every
// name we see from then is a service name (i.e. process_sys_args is set false when we seem them,
// see above).
//
// (Note, you can give "--" on the kernel command line to pass every option from that point to init
// directly, but init doesn't see the "--" itself, which makes it less useful, since we still can't
// tell whether a "name" was intended as a kernel parameter or init parameter).
// So, long story short: if we think we're PID 1 and we haven't seen -m or -c options yet, only
// recognise "single" as a service name and ignore everything else.
if (!opts.process_sys_args || strcmp(argv[i], "single") == 0) {
services_to_start.push_back(argv[i]);
}
#else
services_to_start.push_back(argv[i]);
#endif
}
return 0;
}
// Main entry point
int dinit_main(int argc, char **argv)
{
using namespace std;
am_system_mgr = (getpid() == 1);
am_system_init = (getuid() == 0);
struct options opts;
// if we are PID 1 and user id 0, we are *most probably* the system init. (Or on linux at least, we
// could instead be in a container; then we expect -o argument and unset this then).
opts.process_sys_args = am_system_mgr && am_system_init;
const char * &env_file = opts.env_file;
bool &control_socket_path_set = opts.control_socket_path_set;
bool &env_file_set = opts.env_file_set;
bool &log_specified = opts.log_specified;
service_dir_opt &service_dir_opts = opts.service_dir_opts;
list<const char *> &services_to_start = opts.services_to_start;
for (int i = 1; i < argc; i++) {
int p = process_commandline_arg(argv, argc, i, opts);
if (p == -1) {
// clean exit
return 0;
}
if (p == 1) {
// error exit
return 1;
}
}
if (am_system_mgr) {
// setup STDIN, STDOUT, STDERR so that we can use them
int onefd = open("/dev/console", O_RDONLY, 0);
if (onefd != -1) {
dup2(onefd, 0);
}
int twofd = open("/dev/console", O_RDWR, 0);
if (twofd != -1) {
dup2(twofd, 1);
dup2(twofd, 2);
}
if (onefd > 2) close(onefd);
if (twofd > 2) close(twofd);
if (! env_file_set) {
env_file = env_file_path;
}
// we will assume an empty cgroups root path
#if SUPPORT_CGROUPS
have_cgroups_path = true;
#endif
}
/* Set up signal handlers etc */
sigset_t sigwait_set;
if (am_system_mgr) {
// Block all signals in system manager mode - don't want to chance provoking a signal that
// will suspend or terminate the process
sigfillset(&sigwait_set);
}
else {
sigemptyset(&sigwait_set);
sigaddset(&sigwait_set, SIGCHLD);
sigaddset(&sigwait_set, SIGINT);
sigaddset(&sigwait_set, SIGTERM);
}
sigprocmask(SIG_BLOCK, &sigwait_set, &orig_signal_mask);
// Terminal access control signals - we ignore these so that dinit can't be
// suspended if it writes to the terminal after some other process has claimed
// ownership of it.
signal(SIGTSTP, SIG_IGN);
signal(SIGTTIN, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
signal(SIGPIPE, SIG_IGN);
event_loop.init();
if (!am_system_init && !control_socket_path_set) {
const char * rundir = getenv("XDG_RUNTIME_DIR");
const char * sockname = "dinitctl";
if (rundir == nullptr) {
rundir = service_dir_opt::get_user_home();
sockname = ".dinitctl";
}
if (rundir != nullptr) {
control_socket_str = rundir;
control_socket_str.push_back('/');
control_socket_str += sockname;
control_socket_path = control_socket_str.c_str();
}
}
if (services_to_start.empty()) {
services_to_start.push_back("boot");
}
// Set up signal handlers
callback_signal_handler sigterm_watcher {sigterm_cb};
callback_signal_handler sigint_watcher;
callback_signal_handler sigquit_watcher;
if (am_system_mgr) {
sigint_watcher.set_cb_func(sigint_reboot_cb);
sigquit_watcher.set_cb_func(sigquit_cb);
}
else {
sigint_watcher.set_cb_func(sigterm_cb);
}
sigint_watcher.add_watch(event_loop, SIGINT);
sigterm_watcher.add_watch(event_loop, SIGTERM);
if (am_system_mgr) {
// PID 1: we may ask for console input; SIGQUIT exec's shutdown
console_input_io.add_watch(event_loop, STDIN_FILENO, dasynq::IN_EVENTS, false);
sigquit_watcher.add_watch(event_loop, SIGQUIT);
// (If not PID 1, we instead just let SIGQUIT perform the default action.)
}
init_log(log_is_syslog);
log_flush_timer.add_timer(event_loop, dasynq::clock_type::MONOTONIC);
#if SUPPORT_CGROUPS
if (!have_cgroups_path) {
find_cgroup_path();
// We will press on if the cgroup root path could not be identified, since services might
// not require cgroups anyway and/or might only specify absolute cgroups paths.
}
#endif
// Try to open control socket (may fail due to readonly filesystem, we ignore that if we are
// system init)
if (!open_control_socket(!am_system_init)) {
flush_log();
return EXIT_FAILURE;
}
#ifdef __linux__
if (am_system_mgr) {
// Disable non-critical kernel output to console
klogctl(6 /* SYSLOG_ACTION_CONSOLE_OFF */, nullptr, 0);
// Make ctrl+alt+del combination send SIGINT to PID 1 (this process)
reboot(RB_DISABLE_CAD);
}
// Mark ourselves as a subreaper. This means that if a process we start double-forks, the
// orphaned child will re-parent to us rather than to PID 1 (although that could be us too).
prctl(PR_SET_CHILD_SUBREAPER, 1);
#elif defined(__FreeBSD__) || defined(__DragonFly__)
// Documentation (man page) for this kind-of sucks. PROC_REAP_ACQUIRE "acquires the reaper status for
// the current process" but does that mean the first two arguments still need valid values to be
// supplied? We'll play it safe and explicitly target our own process:
procctl(P_PID, getpid(), PROC_REAP_ACQUIRE, NULL);
#endif
service_dir_opts.build_paths(am_system_init);
// Start requested services
services = new dirload_service_set(std::move(service_dir_opts.get_paths()));
setup_log_console_handoff(services);
if (am_system_init) {
log(loglevel_t::NOTICE, false, "Starting system");
}
// If a log file was specified, open it now.
if (log_specified) {
setup_external_log();
if (!am_system_init && !external_log_open) {
flush_log(); // flush console messages
return EXIT_FAILURE;
}
}
if (env_file != nullptr) {
read_env_file(env_file, true, main_env, false);
}
for (auto svc : services_to_start) {
try {
services->start_service(svc);
// Note in general if we fail to start a service we don't need any special error handling,
// since we either leave other services running or, if it was the only service, then no
// services will be running and we will process normally (reboot if system process,
// exit if user process).
}
catch (service_not_found &snf) {
log(loglevel_t::ERROR, snf.service_name, ": could not find service description.");
}
catch (service_description_exc &sde) {
log_service_load_failure(sde);
}
catch (service_load_exc &sle) {
log(loglevel_t::ERROR, sle.service_name, ": error loading: ", sle.exc_description);
}
catch (std::bad_alloc &badalloce) {
log(loglevel_t::ERROR, "Out of memory when trying to start service: ", svc, ".");
break;
}
}
// Notify readiness just before the event loop starts (and after services
// are scheduled to start). If the socket is not ready yet (may be in case
// of read-only file system), we will report it when it is.
control_socket_ready();
run_event_loop:
// Process events until all services have terminated.
while (services->count_active_services() != 0) {
event_loop.run();
}
shutdown_type_t shutdown_type = services->get_shutdown_type();
if (shutdown_type == shutdown_type_t::REMAIN) {
goto run_event_loop;
}
if (am_system_mgr) {
log_msg_begin(loglevel_t::NOTICE, "No more active services.");
if (shutdown_type == shutdown_type_t::REBOOT) {
log_msg_end(" Will reboot.");
}
if (shutdown_type == shutdown_type_t::SOFTREBOOT) {
log_msg_end(" Will soft-reboot.");
}
else if (shutdown_type == shutdown_type_t::HALT) {
log_msg_end(" Will halt.");
}
else if (shutdown_type == shutdown_type_t::POWEROFF) {
log_msg_end(" Will power down.");
}
else if (shutdown_type == shutdown_type_t::NONE) {
log_msg_end(" Will handle boot failure.");
}
}
flush_log();
bool need_log_flush = false;
close_control_socket();
if (am_system_mgr) {
if (shutdown_type == shutdown_type_t::SOFTREBOOT) {
sync(); // Sync to minimise data loss in case soft-boot fails
execv(dinit_exec, argv);
log(loglevel_t::ERROR, error_exec_dinit, strerror(errno));
// if we get here, soft reboot failed; reboot normally
log(loglevel_t::ERROR, "Could not soft-reboot. Will attempt reboot.");
shutdown_type = shutdown_type_t::REBOOT;
need_log_flush = true;
}
if (shutdown_type == shutdown_type_t::NONE) {
// Services all stopped but there was no shutdown issued. Inform user, wait for ack, and
// re-start boot sequence.
sync(); // Sync to minimise data loss if user elects to power off / hard reset
if (auto_recovery) {
try {
services->start_service("recovery");
}
catch (std::exception &exc) {
log(loglevel_t::ERROR, "Unable to start recovery service: ", exc.what());
// As the following prompt UI could be inaccessible flush the log again already
flush_log();
}
}
confirm_restart_boot();
if (services->count_active_services() != 0) {
// Recovery service started
goto run_event_loop;
}
shutdown_type = services->get_shutdown_type();
if (shutdown_type == shutdown_type_t::NONE) {
try {
services->start_service("boot");
goto run_event_loop; // yes, the "evil" goto
}
catch (...) {
// Couldn't start boot service, let's reboot the system
log(loglevel_t::ERROR, "Could not start 'boot' service. Will attempt reboot.");
need_log_flush = true;
shutdown_type = shutdown_type_t::REBOOT;
}
}
}
if (need_log_flush) {
// In case of error since the log was previously flushed, flush again now
flush_log();
}
const char * cmd_arg;
if (shutdown_type == shutdown_type_t::HALT) {
cmd_arg = "-h";
}
else if (shutdown_type == shutdown_type_t::REBOOT) {
cmd_arg = "-r";
}
else {
// power off.
cmd_arg = "-p";
}
// Fork and execute dinit-reboot.
execl(shutdown_exec.c_str(), shutdown_exec.c_str(), "--system", cmd_arg, nullptr);
log(loglevel_t::ERROR, error_exec_sd, strerror(errno));
// PID 1 must not actually exit, although we should never reach this point:
while (true) {
event_loop.run();
}
}
else if (shutdown_type == shutdown_type_t::REBOOT) {
// Non-system-process. If we got SIGINT, let's die due to it:
sigset_t sigwait_set_int;
sigemptyset(&sigwait_set_int);
sigaddset(&sigwait_set_int, SIGINT);
raise(SIGINT);
sigprocmask(SIG_UNBLOCK, &sigwait_set_int, NULL);
}
return EXIT_SUCCESS;
}
// Get user confirmation before proceeding with restarting boot sequence.
// Returns after confirmation, possibly with shutdown type altered.
static void confirm_restart_boot() noexcept
{
// Bypass log; we want to make certain the message is seen:
std::cout << "All services have stopped with no shutdown issued; boot failure?\n";
// Drain input, set non-canonical input mode (receive characters as they are typed)
struct termios term_attr;
if (tcgetattr(STDIN_FILENO, &term_attr) != 0) {
// Not a terminal?
std::cout << "Halting." << std::endl;
services->stop_all_services(shutdown_type_t::HALT);
return;
}
term_attr.c_lflag &= ~ICANON;
tcsetattr(STDIN_FILENO, TCSAFLUSH, &term_attr);
// Set non-blocking mode
int origFlags = fcntl(STDIN_FILENO, F_GETFL);
fcntl(STDIN_FILENO, F_SETFL, origFlags | O_NONBLOCK);
do_prompt:
std::cout << "Choose: (r)eboot, r(e)covery, re(s)tart boot sequence, (p)ower off? " << std::flush;
console_input_io.set_enabled(event_loop, true);
do {
event_loop.run();
} while (! console_input_ready && services->get_shutdown_type() == shutdown_type_t::NONE);
console_input_io.set_enabled(event_loop, false);
// We either have input, or shutdown type has been set, or both.
if (console_input_ready) {
console_input_ready = false;
char buf[1];
int r = read(STDIN_FILENO, buf, 1); // read a single character, to make sure we wait for input
if (r == 1) {
std::cout << "\n"; // force new line after input
if (buf[0] == 'r' || buf[0] == 'R') {
services->stop_all_services(shutdown_type_t::REBOOT);
}
else if (buf[0] == 'e' || buf[0] == 'E') {
try {
services->start_service("recovery");
}
catch (...) {
std::cout << "Unable to start recovery service.\n";
goto do_prompt;
}
}
else if (buf[0] == 's' || buf[0] == 'S') {
// nothing - leave no shutdown type
}
else if (buf[0] == 'p' || buf[0] == 'P') {
services->stop_all_services(shutdown_type_t::POWEROFF);
}
else {
goto do_prompt;
}
}
tcflush(STDIN_FILENO, TCIFLUSH); // discard the rest of input
}
term_attr.c_lflag |= ICANON;
tcsetattr(STDIN_FILENO, TCSANOW, &term_attr);
fcntl(STDIN_FILENO, F_SETFL, origFlags);
}
// Callback for control socket
static void control_socket_cb(eventloop_t *loop, int sockfd) noexcept
{
// Considered keeping a limit the number of active connections, however, there doesn't
// seem much to be gained from that. Only root can create connections and not being
// able to establish a control connection is as much a denial-of-service as is not being
// able to start a service due to lack of fd's.
// Accept a connection
int newfd = dinit_accept4(sockfd, nullptr, nullptr, SOCK_NONBLOCK | SOCK_CLOEXEC);
if (newfd != -1) {
try {
new control_conn_t(*loop, services, newfd); // will delete itself when it's finished
}
catch (std::exception &exc) {
log(loglevel_t::ERROR, "Error accepting control connection: ", exc.what());
close(newfd);
}
}
}
static void control_socket_ready() noexcept
{
if (!control_socket_open || socket_ready_fd < 0) {
return;
}
write(socket_ready_fd, control_socket_path, strlen(control_socket_path) + 1);
// Once done with, close it (but leave stdout/stderr alone)
if (socket_ready_fd > 2) {
close(socket_ready_fd);
}
// Ensure that we don't try to issue readiness again:
socket_ready_fd = -1;
}
// Callback when the root filesystem is read/write:
void rootfs_is_rw() noexcept
{
open_control_socket(true);
control_socket_ready();
if (!log_is_syslog && !external_log_open) {
// Try (again) to open log file if we couldn't do so earlier.
setup_external_log();
}
if (!did_log_boot) {
did_log_boot = log_boot();
}
}
// Open/create the control socket, normally /run/dinitctl, used to allow client programs to connect
// and issue service orders and shutdown commands etc. This can safely be called multiple times;
// once the socket has been successfully opened, further calls will check the socket file is still
// present and re-create it if not.
static bool open_control_socket(bool report_ro_failure) noexcept
{
if (control_socket_open) {
struct stat stat_buf;
if (stat(control_socket_path, &stat_buf) != 0 && errno == ENOENT) {
// Looks like our control socket has disappeared from the filesystem. Close our control
// socket and re-create it:
control_socket_io.deregister(event_loop);
close(control_socket_io.get_watched_fd());
control_socket_open = false; // now re-open below
}
}
if (!control_socket_open) {
const char * saddrname = control_socket_path;
size_t saddrname_len = strlen(saddrname);
uint sockaddr_size = offsetof(struct sockaddr_un, sun_path) + saddrname_len + 1;
struct sockaddr_un * name = static_cast<sockaddr_un *>(malloc(sockaddr_size));
if (name == nullptr) {
log(loglevel_t::ERROR, "Opening control socket: out of memory");
return false;
}
name->sun_family = AF_UNIX;
memcpy(name->sun_path, saddrname, saddrname_len + 1);
int sockfd = dinit_socket(AF_UNIX, SOCK_STREAM, 0, SOCK_NONBLOCK | SOCK_CLOEXEC);
if (sockfd == -1) {
log(loglevel_t::ERROR, "Error creating control socket: ", strerror(errno));
free(name);
return false;
}
// Check if there is already an active control socket (from another instance).
// Unfortunately, there's no way to check atomically if a socket file is stale. Still, we
// will try to check, since the consequences of running a system dinit instance twice are
// potentially severe.
int connr = connect(sockfd, (struct sockaddr *) name, sockaddr_size);
if (connr != -1 || errno == EAGAIN) {
log(loglevel_t::ERROR, "Control socket is already active"
" (another instance already running?)");
close(connr);
close(sockfd);
free(name);
return false;
}
// Unlink any stale control socket file.
//
// In the worst case, this potentially removes a socket which was not active at the time
// we checked (just above) but has since become active; there's just no good API to avoid
// this (we'd have to use a file lock, on yet another file). Since that's unlikely to
// occur in practice, and because a stale socket will prevent communication with dinit (or
// prevent it starting), then we'll take the chance on unlinking here.
unlink(saddrname);
if (bind(sockfd, (struct sockaddr *) name, sockaddr_size) == -1) {
bool have_error = (errno != EROFS || report_ro_failure);
if (have_error) {
log(loglevel_t::ERROR, "Error binding control socket: ", strerror(errno));
}
close(sockfd);
free(name);
return !have_error;
}
free(name);
// No connections can be made until we listen, so it is fine to change the permissions now
// (and anyway there is no way to atomically create the socket and set permissions):
if (chmod(saddrname, S_IRUSR | S_IWUSR) == -1) {
log(loglevel_t::ERROR, "Error setting control socket permissions: ", strerror(errno));
close(sockfd);
return false;
}
if (listen(sockfd, 10) == -1) {
log(loglevel_t::ERROR, "Error listening on control socket: ", strerror(errno));
close(sockfd);