src/service.cc

   1 #include <cstring>
   2 #include <cerrno>
   3 #include <iterator>
   4 #include <memory>
   5 #include <cstddef>
   6
   7 #include <sys/ioctl.h>
   8 #include <fcntl.h>
   9 #include <termios.h>
  10
  11 #include "dinit.h"
  12 #include "service.h"
  13 #include "dinit-log.h"
  14 #include "dinit-socket.h"
  15 #include "dinit-util.h"
  16 #include "baseproc-sys.h"
  17
  18 /*
  19  * service.cc - Service management.
  20  * See service.h for details.
  21  */
  22
  23 // Find the requested service by name
  24 static service_record * find_service(const std::list<service_record *> & records,
  25                                     const char *name) noexcept
  26 {
  27     using std::list;
  28     list<service_record *>::const_iterator i = records.begin();
  29     for ( ; i != records.end(); i++ ) {
  30         if (strcmp((*i)->get_name().c_str(), name) == 0) {
  31             return *i;
  32         }
  33     }
  34     return nullptr;
  35 }
  36
  37 service_record * service_set::find_service(const std::string &name) noexcept
  38 {
  39     return ::find_service(records, name.c_str());
  40 }
  41
  42 void service_set::stop_service(const std::string & name) noexcept
  43 {
  44     service_record *record = find_service(name);
  45     if (record != nullptr) {
  46         record->stop();
  47         process_queues();
  48     }
  49 }
  50
  51 // Called when a service has actually stopped; dependents have stopped already, unless this stop
  52 // is due to an unexpected process termination.
  53 void service_record::stopped() noexcept
  54 {
  55     if (onstart_flags.runs_on_console) {
  56         bp_sys::tcsetpgrp(0, bp_sys::getpgrp());
  57         discard_console_log_buffer();
  58         release_console();
  59     }
  60
  61     force_stop = false;
  62
  63     // If we are a soft dependency of another target, break the acquisition from that target now:
  64     for (auto & dependent : dependents) {
  65         if (dependent->dep_type != dependency_type::REGULAR) {
  66             if (dependent->holding_acq) {
  67                 dependent->holding_acq = false;
  68                 release();
  69             }
  70         }
  71     }
  72
  73     bool will_restart = (desired_state == service_state_t::STARTED)
  74             && services->get_auto_restart();
  75
  76     for (auto dependency : depends_on) {
  77         // we signal dependencies in case they are waiting for us to stop:
  78         dependency.get_to()->dependent_stopped();
  79     }
  80
  81     service_state = service_state_t::STOPPED;
  82
  83     if (will_restart) {
  84         // Desired state is "started".
  85         restarting = true;
  86         start(false);
  87     }
  88     else {
  89         becoming_inactive();
  90
  91         if (start_explicit) {
  92             start_explicit = false;
  93             release();
  94         }
  95         else if (required_by == 0) {
  96             services->service_inactive(this);
  97         }
  98     }
  99
 100     log_service_stopped(service_name);
 101     notify_listeners(service_event_t::STOPPED);
 102 }
 103
 104 bool service_record::do_auto_restart() noexcept
 105 {
 106     if (auto_restart) {
 107         return services->get_auto_restart();
 108     }
 109     return false;
 110 }
 111
 112 void service_record::require() noexcept
 113 {
 114     if (required_by++ == 0) {
 115         prop_require = !prop_release;
 116         prop_release = false;
 117         services->add_prop_queue(this);
 118     }
 119 }
 120
 121 void service_record::release(bool issue_stop) noexcept
 122 {
 123     if (--required_by == 0) {
 124         desired_state = service_state_t::STOPPED;
 125
 126         // Can stop, and can release dependencies now. We don't need to issue a release if
 127         // the require was pending though:
 128         prop_release = !prop_require;
 129         prop_require = false;
 130         services->add_prop_queue(this);
 131
 132         if (service_state == service_state_t::STOPPED) {
 133             services->service_inactive(this);
 134         }
 135         else if (issue_stop) {
 136             do_stop();
 137         }
 138     }
 139 }
 140
 141 void service_record::release_dependencies() noexcept
 142 {
 143     for (auto & dependency : depends_on) {
 144         service_record * dep_to = dependency.get_to();
 145         if (dependency.holding_acq) {
 146             dep_to->release();
 147             dependency.holding_acq = false;
 148         }
 149     }
 150 }
 151
 152 void service_record::start(bool activate) noexcept
 153 {
 154     if (activate && ! start_explicit) {
 155         require();
 156         start_explicit = true;
 157     }
 158
 159     if (desired_state == service_state_t::STARTED && service_state != service_state_t::STOPPED) return;
 160
 161     bool was_active = service_state != service_state_t::STOPPED || desired_state != service_state_t::STOPPED;
 162     desired_state = service_state_t::STARTED;
 163
 164     if (service_state != service_state_t::STOPPED) {
 165         // We're already starting/started, or we are stopping and need to wait for
 166         // that the complete.
 167         if (service_state != service_state_t::STOPPING || ! can_interrupt_stop()) {
 168             return;
 169         }
 170         // We're STOPPING, and that can be interrupted. Our dependencies might be STOPPING,
 171         // but if so they are waiting (for us), so they too can be instantly returned to
 172         // STARTING state.
 173         notify_listeners(service_event_t::STOPCANCELLED);
 174     }
 175     else if (! was_active) {
 176         services->service_active(this);
 177     }
 178
 179     service_state = service_state_t::STARTING;
 180     waiting_for_deps = true;
 181
 182     if (start_check_dependencies()) {
 183         services->add_transition_queue(this);
 184     }
 185 }
 186
 187 void service_record::do_propagation() noexcept
 188 {
 189     if (prop_require) {
 190         // Need to require all our dependencies
 191         for (auto & dep : depends_on) {
 192             dep.get_to()->require();
 193             dep.holding_acq = true;
 194         }
 195         prop_require = false;
 196     }
 197
 198     if (prop_release) {
 199         release_dependencies();
 200         prop_release = false;
 201     }
 202
 203     if (prop_failure) {
 204         prop_failure = false;
 205         failed_to_start(true);
 206     }
 207
 208     if (prop_start) {
 209         prop_start = false;
 210         start(false);
 211     }
 212
 213     if (prop_stop) {
 214         prop_stop = false;
 215         do_stop();
 216     }
 217 }
 218
 219 void service_record::execute_transition() noexcept
 220 {
 221     // state is STARTED with restarting set true if we are running a smooth recovery.
 222     if (service_state == service_state_t::STARTING || (service_state == service_state_t::STARTED
 223             && restarting)) {
 224         if (check_deps_started()) {
 225             all_deps_started();
 226         }
 227     }
 228     else if (service_state == service_state_t::STOPPING) {
 229         if (stop_check_dependents()) {
 230             waiting_for_deps = false;
 231             bring_down();
 232         }
 233     }
 234 }
 235
 236 void service_record::do_start() noexcept
 237 {
 238     if (pinned_stopped) return;
 239
 240     if (service_state != service_state_t::STARTING) {
 241         return;
 242     }
 243
 244     service_state = service_state_t::STARTING;
 245
 246     waiting_for_deps = true;
 247
 248     // Ask dependencies to start, mark them as being waited on.
 249     if (check_deps_started()) {
 250         // Once all dependencies are started, we start properly:
 251         all_deps_started();
 252     }
 253 }
 254
 255 void service_record::dependency_started() noexcept
 256 {
 257     if ((service_state == service_state_t::STARTING || service_state == service_state_t::STARTED)
 258             && waiting_for_deps) {
 259         services->add_transition_queue(this);
 260     }
 261 }
 262
 263 bool service_record::start_check_dependencies() noexcept
 264 {
 265     bool all_deps_started = true;
 266
 267     for (auto & dep : depends_on) {
 268         service_record * to = dep.get_to();
 269         if (to->service_state != service_state_t::STARTED) {
 270             if (to->service_state != service_state_t::STARTING) {
 271                 to->prop_start = true;
 272                 services->add_prop_queue(to);
 273             }
 274             dep.waiting_on = true;
 275             all_deps_started = false;
 276         }
 277     }
 278
 279     return all_deps_started;
 280 }
 281
 282 bool service_record::check_deps_started() noexcept
 283 {
 284     for (auto & dep : depends_on) {
 285         if (dep.waiting_on) {
 286             return false;
 287         }
 288     }
 289
 290     return true;
 291 }
 292
 293 void service_record::all_deps_started() noexcept
 294 {
 295     if (onstart_flags.starts_on_console && ! have_console) {
 296         queue_for_console();
 297         return;
 298     }
 299
 300     waiting_for_deps = false;
 301
 302     if (! can_proceed_to_start()) {
 303         waiting_for_deps = true;
 304         return;
 305     }
 306
 307     bool start_success = bring_up();
 308     if (! start_success) {
 309         failed_to_start();
 310     }
 311 }
 312
 313 void service_record::acquired_console() noexcept
 314 {
 315     waiting_for_console = false;
 316     have_console = true;
 317
 318     if (service_state != service_state_t::STARTING) {
 319         // We got the console but no longer want it.
 320         release_console();
 321     }
 322     else if (check_deps_started()) {
 323         all_deps_started();
 324     }
 325     else {
 326         // We got the console but can't use it yet.
 327         release_console();
 328     }
 329 }
 330
 331 void service_record::started() noexcept
 332 {
 333     // If we start on console but don't keep it, release it now:
 334     if (have_console && ! onstart_flags.runs_on_console) {
 335         bp_sys::tcsetpgrp(0, bp_sys::getpgrp());
 336         release_console();
 337     }
 338
 339     log_service_started(get_name());
 340     service_state = service_state_t::STARTED;
 341     notify_listeners(service_event_t::STARTED);
 342
 343     if (onstart_flags.rw_ready) {
 344         open_control_socket();
 345     }
 346     if (onstart_flags.log_ready) {
 347         setup_external_log();
 348     }
 349
 350     if (force_stop || desired_state == service_state_t::STOPPED) {
 351         // We must now stop.
 352         do_stop();
 353         return;
 354     }
 355
 356     // Notify any dependents whose desired state is STARTED:
 357     for (auto dept : dependents) {
 358         dept->get_from()->dependency_started();
 359         dept->waiting_on = false;
 360     }
 361 }
 362
 363 void service_record::failed_to_start(bool depfailed) noexcept
 364 {
 365     if (have_console) {
 366         bp_sys::tcsetpgrp(0, bp_sys::getpgrp());
 367         release_console();
 368     }
 369     if (waiting_for_console) {
 370         services->unqueue_console(this);
 371         waiting_for_console = false;
 372     }
 373
 374     log_service_failed(get_name());
 375     service_state = service_state_t::STOPPED;
 376     if (start_explicit) {
 377         start_explicit = false;
 378         release(false);
 379     }
 380     notify_listeners(service_event_t::FAILEDSTART);
 381
 382     // Cancel start of dependents:
 383     for (auto & dept : dependents) {
 384         switch (dept->dep_type) {
 385         case dependency_type::REGULAR:
 386         case dependency_type::MILESTONE:
 387             if (dept->get_from()->service_state == service_state_t::STARTING) {
 388                 dept->get_from()->prop_failure = true;
 389                 services->add_prop_queue(dept->get_from());
 390             }
 391             break;
 392         case dependency_type::WAITS_FOR:
 393         case dependency_type::SOFT:
 394             if (dept->waiting_on) {
 395                 dept->waiting_on = false;
 396                 dept->get_from()->dependency_started();
 397             }
 398             if (dept->holding_acq) {
 399                 dept->holding_acq = false;
 400                 release();
 401             }
 402         }
 403     }
 404 }
 405
 406 bool service_record::bring_up() noexcept
 407 {
 408     // default implementation: there is no process, so we are started.
 409     started();
 410     return true;
 411 }
 412
 413 // Mark this and all dependent services as force-stopped.
 414 void service_record::forced_stop() noexcept
 415 {
 416     if (service_state != service_state_t::STOPPED) {
 417         force_stop = true;
 418         if (! pinned_started) {
 419             prop_stop = true;
 420             services->add_transition_queue(this);
 421         }
 422     }
 423 }
 424
 425 void service_record::dependent_stopped() noexcept
 426 {
 427     if (service_state == service_state_t::STOPPING && waiting_for_deps) {
 428         services->add_transition_queue(this);
 429     }
 430 }
 431
 432 void service_record::stop(bool bring_down) noexcept
 433 {
 434     if (start_explicit) {
 435         start_explicit = false;
 436         release();
 437     }
 438
 439     if (bring_down) {
 440         do_stop();
 441     }
 442 }
 443
 444 void service_record::do_stop() noexcept
 445 {
 446     if (pinned_started) return;
 447
 448     if (start_explicit && ! do_auto_restart()) {
 449         start_explicit = false;
 450         release(false);
 451     }
 452
 453     bool all_deps_stopped = stop_dependents();
 454
 455     if (service_state != service_state_t::STARTED) {
 456         if (service_state == service_state_t::STARTING) {
 457             // If waiting for a dependency, or waiting for the console, we can interrupt start. Otherwise,
 458             // we need to delegate to can_interrupt_start() (which can be overridden).
 459             if (! waiting_for_deps && ! waiting_for_console) {
 460                 if (! can_interrupt_start()) {
 461                     // Well this is awkward: we're going to have to continue starting. We can stop once we've
 462                     // reached the started state.
 463                     return;
 464                 }
 465
 466                 if (! interrupt_start()) {
 467                     // Now wait for service startup to actually end; we don't need to handle it here.
 468                     return;
 469                 }
 470             }
 471             else if (waiting_for_console) {
 472                 services->unqueue_console(this);
 473                 waiting_for_console = false;
 474             }
 475
 476             // We must have had desired_state == STARTED.
 477             notify_listeners(service_event_t::STARTCANCELLED);
 478
 479             // Reaching this point, we are starting interruptibly - so we
 480             // stop now (by falling through to below).
 481         }
 482         else {
 483             // If we're starting we need to wait for that to complete.
 484             // If we're already stopping/stopped there's nothing to do.
 485             return;
 486         }
 487     }
 488
 489     service_state = service_state_t::STOPPING;
 490     waiting_for_deps = true;
 491     if (all_deps_stopped) {
 492         services->add_transition_queue(this);
 493     }
 494 }
 495
 496 bool service_record::stop_check_dependents() noexcept
 497 {
 498     bool all_deps_stopped = true;
 499     for (auto dept : dependents) {
 500         if (dept->dep_type == dependency_type::REGULAR && ! dept->get_from()->is_stopped()) {
 501             all_deps_stopped = false;
 502             break;
 503         }
 504     }
 505
 506     return all_deps_stopped;
 507 }
 508
 509 bool service_record::stop_dependents() noexcept
 510 {
 511     bool all_deps_stopped = true;
 512     for (auto dept : dependents) {
 513         if (dept->dep_type == dependency_type::REGULAR) {
 514             if (! dept->get_from()->is_stopped()) {
 515                 // Note we check *first* since if the dependent service is not stopped,
 516                 // 1. We will issue a stop to it shortly and
 517                 // 2. It will notify us when stopped, at which point the stop_check_dependents()
 518                 //    check is run anyway.
 519                 all_deps_stopped = false;
 520             }
 521
 522             if (force_stop) {
 523                 // If this service is to be forcefully stopped, dependents must also be.
 524                 dept->get_from()->forced_stop();
 525             }
 526
 527             dept->get_from()->prop_stop = true;
 528             services->add_prop_queue(dept->get_from());
 529         }
 530     }
 531
 532     return all_deps_stopped;
 533 }
 534
 535 // All dependents have stopped; we can stop now, too. Only called when STOPPING.
 536 void service_record::bring_down() noexcept
 537 {
 538     waiting_for_deps = false;
 539     stopped();
 540 }
 541
 542 void service_record::unpin() noexcept
 543 {
 544     if (pinned_started) {
 545         pinned_started = false;
 546         if (desired_state == service_state_t::STOPPED || force_stop) {
 547             do_stop();
 548             services->process_queues();
 549         }
 550     }
 551     if (pinned_stopped) {
 552         pinned_stopped = false;
 553         if (desired_state == service_state_t::STARTED) {
 554             do_start();
 555             services->process_queues();
 556         }
 557     }
 558 }
 559
 560 void service_record::queue_for_console() noexcept
 561 {
 562     waiting_for_console = true;
 563     services->append_console_queue(this);
 564 }
 565
 566 void service_record::release_console() noexcept
 567 {
 568     have_console = false;
 569     services->pull_console_queue();
 570 }
 571
 572 bool service_record::interrupt_start() noexcept
 573 {
 574     if (onstart_flags.starts_on_console) {
 575         services->unqueue_console(this);
 576     }
 577     return true;
 578 }
 579
 580 void service_set::service_active(service_record *sr) noexcept
 581 {
 582     active_services++;
 583 }
 584
 585 void service_set::service_inactive(service_record *sr) noexcept
 586 {
 587     active_services--;
 588 }