src/core/busname.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2013 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <sys/mman.h>
  21
  22 #include "alloc-util.h"
  23 #include "bus-internal.h"
  24 #include "bus-kernel.h"
  25 #include "bus-policy.h"
  26 #include "bus-util.h"
  27 #include "busname.h"
  28 #include "dbus-busname.h"
  29 #include "fd-util.h"
  30 #include "formats-util.h"
  31 #include "kdbus.h"
  32 #include "parse-util.h"
  33 #include "process-util.h"
  34 #include "service.h"
  35 #include "signal-util.h"
  36 #include "special.h"
  37 #include "string-table.h"
  38 #include "string-util.h"
  39
  40 static const UnitActiveState state_translation_table[_BUSNAME_STATE_MAX] = {
  41         [BUSNAME_DEAD] = UNIT_INACTIVE,
  42         [BUSNAME_MAKING] = UNIT_ACTIVATING,
  43         [BUSNAME_REGISTERED] = UNIT_ACTIVE,
  44         [BUSNAME_LISTENING] = UNIT_ACTIVE,
  45         [BUSNAME_RUNNING] = UNIT_ACTIVE,
  46         [BUSNAME_SIGTERM] = UNIT_DEACTIVATING,
  47         [BUSNAME_SIGKILL] = UNIT_DEACTIVATING,
  48         [BUSNAME_FAILED] = UNIT_FAILED
  49 };
  50
  51 static int busname_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
  52 static int busname_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
  53
  54 static void busname_init(Unit *u) {
  55         BusName *n = BUSNAME(u);
  56
  57         assert(u);
  58         assert(u->load_state == UNIT_STUB);
  59
  60         n->starter_fd = -1;
  61         n->accept_fd = true;
  62         n->activating = true;
  63
  64         n->timeout_usec = u->manager->default_timeout_start_usec;
  65 }
  66
  67 static void busname_unwatch_control_pid(BusName *n) {
  68         assert(n);
  69
  70         if (n->control_pid <= 0)
  71                 return;
  72
  73         unit_unwatch_pid(UNIT(n), n->control_pid);
  74         n->control_pid = 0;
  75 }
  76
  77 static void busname_free_policy(BusName *n) {
  78         BusNamePolicy *p;
  79
  80         assert(n);
  81
  82         while ((p = n->policy)) {
  83                 LIST_REMOVE(policy, n->policy, p);
  84
  85                 free(p->name);
  86                 free(p);
  87         }
  88 }
  89
  90 static void busname_close_fd(BusName *n) {
  91         assert(n);
  92
  93         n->starter_event_source = sd_event_source_unref(n->starter_event_source);
  94         n->starter_fd = safe_close(n->starter_fd);
  95 }
  96
  97 static void busname_done(Unit *u) {
  98         BusName *n = BUSNAME(u);
  99
 100         assert(n);
 101
 102         n->name = mfree(n->name);
 103
 104         busname_free_policy(n);
 105         busname_unwatch_control_pid(n);
 106         busname_close_fd(n);
 107
 108         unit_ref_unset(&n->service);
 109
 110         n->timer_event_source = sd_event_source_unref(n->timer_event_source);
 111 }
 112
 113 static int busname_arm_timer(BusName *n, usec_t usec) {
 114         int r;
 115
 116         assert(n);
 117
 118         if (n->timer_event_source) {
 119                 r = sd_event_source_set_time(n->timer_event_source, usec);
 120                 if (r < 0)
 121                         return r;
 122
 123                 return sd_event_source_set_enabled(n->timer_event_source, SD_EVENT_ONESHOT);
 124         }
 125
 126         if (usec == USEC_INFINITY)
 127                 return 0;
 128
 129         r = sd_event_add_time(
 130                         UNIT(n)->manager->event,
 131                         &n->timer_event_source,
 132                         CLOCK_MONOTONIC,
 133                         usec, 0,
 134                         busname_dispatch_timer, n);
 135         if (r < 0)
 136                 return r;
 137
 138         (void) sd_event_source_set_description(n->timer_event_source, "busname-timer");
 139
 140         return 0;
 141 }
 142
 143 static int busname_add_default_default_dependencies(BusName *n) {
 144         int r;
 145
 146         assert(n);
 147
 148         r = unit_add_dependency_by_name(UNIT(n), UNIT_BEFORE, SPECIAL_BUSNAMES_TARGET, NULL, true);
 149         if (r < 0)
 150                 return r;
 151
 152         if (MANAGER_IS_SYSTEM(UNIT(n)->manager)) {
 153                 r = unit_add_two_dependencies_by_name(UNIT(n), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true);
 154                 if (r < 0)
 155                         return r;
 156         }
 157
 158         return unit_add_two_dependencies_by_name(UNIT(n), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
 159 }
 160
 161 static int busname_add_extras(BusName *n) {
 162         Unit *u = UNIT(n);
 163         int r;
 164
 165         assert(n);
 166
 167         if (!n->name) {
 168                 r = unit_name_to_prefix(u->id, &n->name);
 169                 if (r < 0)
 170                         return r;
 171         }
 172
 173         if (!u->description) {
 174                 r = unit_set_description(u, n->name);
 175                 if (r < 0)
 176                         return r;
 177         }
 178
 179         if (n->activating) {
 180                 if (!UNIT_DEREF(n->service)) {
 181                         Unit *x;
 182
 183                         r = unit_load_related_unit(u, ".service", &x);
 184                         if (r < 0)
 185                                 return r;
 186
 187                         unit_ref_set(&n->service, x);
 188                 }
 189
 190                 r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, UNIT_DEREF(n->service), true);
 191                 if (r < 0)
 192                         return r;
 193         }
 194
 195         if (u->default_dependencies) {
 196                 r = busname_add_default_default_dependencies(n);
 197                 if (r < 0)
 198                         return r;
 199         }
 200
 201         return 0;
 202 }
 203
 204 static int busname_verify(BusName *n) {
 205         char *e;
 206
 207         assert(n);
 208
 209         if (UNIT(n)->load_state != UNIT_LOADED)
 210                 return 0;
 211
 212         if (!service_name_is_valid(n->name)) {
 213                 log_unit_error(UNIT(n), "Name= setting is not a valid service name Refusing.");
 214                 return -EINVAL;
 215         }
 216
 217         e = strjoina(n->name, ".busname");
 218         if (!unit_has_name(UNIT(n), e)) {
 219                 log_unit_error(UNIT(n), "Name= setting doesn't match unit name. Refusing.");
 220                 return -EINVAL;
 221         }
 222
 223         return 0;
 224 }
 225
 226 static int busname_load(Unit *u) {
 227         BusName *n = BUSNAME(u);
 228         int r;
 229
 230         assert(u);
 231         assert(u->load_state == UNIT_STUB);
 232
 233         r = unit_load_fragment_and_dropin(u);
 234         if (r < 0)
 235                 return r;
 236
 237         if (u->load_state == UNIT_LOADED) {
 238                 /* This is a new unit? Then let's add in some extras */
 239                 r = busname_add_extras(n);
 240                 if (r < 0)
 241                         return r;
 242         }
 243
 244         return busname_verify(n);
 245 }
 246
 247 static void busname_dump(Unit *u, FILE *f, const char *prefix) {
 248         BusName *n = BUSNAME(u);
 249
 250         assert(n);
 251         assert(f);
 252
 253         fprintf(f,
 254                 "%sBus Name State: %s\n"
 255                 "%sResult: %s\n"
 256                 "%sName: %s\n"
 257                 "%sActivating: %s\n"
 258                 "%sAccept FD: %s\n",
 259                 prefix, busname_state_to_string(n->state),
 260                 prefix, busname_result_to_string(n->result),
 261                 prefix, n->name,
 262                 prefix, yes_no(n->activating),
 263                 prefix, yes_no(n->accept_fd));
 264
 265         if (n->control_pid > 0)
 266                 fprintf(f,
 267                         "%sControl PID: "PID_FMT"\n",
 268                         prefix, n->control_pid);
 269 }
 270
 271 static void busname_unwatch_fd(BusName *n) {
 272         int r;
 273
 274         assert(n);
 275
 276         if (!n->starter_event_source)
 277                 return;
 278
 279         r = sd_event_source_set_enabled(n->starter_event_source, SD_EVENT_OFF);
 280         if (r < 0)
 281                 log_unit_debug_errno(UNIT(n), r, "Failed to disable event source: %m");
 282 }
 283
 284 static int busname_watch_fd(BusName *n) {
 285         int r;
 286
 287         assert(n);
 288
 289         if (n->starter_fd < 0)
 290                 return 0;
 291
 292         if (n->starter_event_source) {
 293                 r = sd_event_source_set_enabled(n->starter_event_source, SD_EVENT_ON);
 294                 if (r < 0)
 295                         goto fail;
 296         } else {
 297                 r = sd_event_add_io(UNIT(n)->manager->event, &n->starter_event_source, n->starter_fd, EPOLLIN, busname_dispatch_io, n);
 298                 if (r < 0)
 299                         goto fail;
 300
 301                 (void) sd_event_source_set_description(n->starter_event_source, "busname-starter");
 302         }
 303
 304         return 0;
 305
 306 fail:
 307         log_unit_warning_errno(UNIT(n), r, "Failed to watch starter fd: %m");
 308         busname_unwatch_fd(n);
 309         return r;
 310 }
 311
 312 static int busname_open_fd(BusName *n) {
 313         _cleanup_free_ char *path = NULL;
 314         const char *mode;
 315
 316         assert(n);
 317
 318         if (n->starter_fd >= 0)
 319                 return 0;
 320
 321         mode = MANAGER_IS_SYSTEM(UNIT(n)->manager) ? "system" : "user";
 322         n->starter_fd = bus_kernel_open_bus_fd(mode, &path);
 323         if (n->starter_fd < 0)
 324                 return log_unit_warning_errno(UNIT(n), n->starter_fd, "Failed to open %s: %m", path ?: "kdbus");
 325
 326         return 0;
 327 }
 328
 329 static void busname_set_state(BusName *n, BusNameState state) {
 330         BusNameState old_state;
 331         assert(n);
 332
 333         old_state = n->state;
 334         n->state = state;
 335
 336         if (!IN_SET(state, BUSNAME_MAKING, BUSNAME_SIGTERM, BUSNAME_SIGKILL)) {
 337                 n->timer_event_source = sd_event_source_unref(n->timer_event_source);
 338                 busname_unwatch_control_pid(n);
 339         }
 340
 341         if (state != BUSNAME_LISTENING)
 342                 busname_unwatch_fd(n);
 343
 344         if (!IN_SET(state, BUSNAME_LISTENING, BUSNAME_MAKING, BUSNAME_REGISTERED, BUSNAME_RUNNING))
 345                 busname_close_fd(n);
 346
 347         if (state != old_state)
 348                 log_unit_debug(UNIT(n), "Changed %s -> %s", busname_state_to_string(old_state), busname_state_to_string(state));
 349
 350         unit_notify(UNIT(n), state_translation_table[old_state], state_translation_table[state], true);
 351 }
 352
 353 static int busname_coldplug(Unit *u) {
 354         BusName *n = BUSNAME(u);
 355         int r;
 356
 357         assert(n);
 358         assert(n->state == BUSNAME_DEAD);
 359
 360         if (n->deserialized_state == n->state)
 361                 return 0;
 362
 363         if (n->control_pid > 0 &&
 364             pid_is_unwaited(n->control_pid) &&
 365             IN_SET(n->deserialized_state, BUSNAME_MAKING, BUSNAME_SIGTERM, BUSNAME_SIGKILL)) {
 366
 367                 r = unit_watch_pid(UNIT(n), n->control_pid);
 368                 if (r < 0)
 369                         return r;
 370
 371                 r = busname_arm_timer(n, usec_add(u->state_change_timestamp.monotonic, n->timeout_usec));
 372                 if (r < 0)
 373                         return r;
 374         }
 375
 376         if (IN_SET(n->deserialized_state, BUSNAME_MAKING, BUSNAME_LISTENING, BUSNAME_REGISTERED, BUSNAME_RUNNING)) {
 377                 r = busname_open_fd(n);
 378                 if (r < 0)
 379                         return r;
 380         }
 381
 382         if (n->deserialized_state == BUSNAME_LISTENING) {
 383                 r = busname_watch_fd(n);
 384                 if (r < 0)
 385                         return r;
 386         }
 387
 388         busname_set_state(n, n->deserialized_state);
 389         return 0;
 390 }
 391
 392 static int busname_make_starter(BusName *n, pid_t *_pid) {
 393         pid_t pid;
 394         int r;
 395
 396         r = busname_arm_timer(n, usec_add(now(CLOCK_MONOTONIC), n->timeout_usec));
 397         if (r < 0)
 398                 goto fail;
 399
 400         /* We have to resolve the user/group names out-of-process,
 401          * hence let's fork here. It's messy, but well, what can we
 402          * do? */
 403
 404         pid = fork();
 405         if (pid < 0)
 406                 return -errno;
 407
 408         if (pid == 0) {
 409                 int ret;
 410
 411                 (void) default_signals(SIGNALS_CRASH_HANDLER, SIGNALS_IGNORE, -1);
 412                 (void) ignore_signals(SIGPIPE, -1);
 413                 log_forget_fds();
 414
 415                 r = bus_kernel_make_starter(n->starter_fd, n->name, n->activating, n->accept_fd, n->policy, n->policy_world);
 416                 if (r < 0) {
 417                         ret = EXIT_MAKE_STARTER;
 418                         goto fail_child;
 419                 }
 420
 421                 _exit(0);
 422
 423         fail_child:
 424                 log_open();
 425                 log_error_errno(r, "Failed to create starter connection at step %s: %m", exit_status_to_string(ret, EXIT_STATUS_SYSTEMD));
 426
 427                 _exit(ret);
 428         }
 429
 430         r = unit_watch_pid(UNIT(n), pid);
 431         if (r < 0)
 432                 goto fail;
 433
 434         *_pid = pid;
 435         return 0;
 436
 437 fail:
 438         n->timer_event_source = sd_event_source_unref(n->timer_event_source);
 439         return r;
 440 }
 441
 442 static void busname_enter_dead(BusName *n, BusNameResult f) {
 443         assert(n);
 444
 445         if (f != BUSNAME_SUCCESS)
 446                 n->result = f;
 447
 448         busname_set_state(n, n->result != BUSNAME_SUCCESS ? BUSNAME_FAILED : BUSNAME_DEAD);
 449 }
 450
 451 static void busname_enter_signal(BusName *n, BusNameState state, BusNameResult f) {
 452         KillContext kill_context = {};
 453         int r;
 454
 455         assert(n);
 456
 457         if (f != BUSNAME_SUCCESS)
 458                 n->result = f;
 459
 460         kill_context_init(&kill_context);
 461
 462         r = unit_kill_context(UNIT(n),
 463                               &kill_context,
 464                               state != BUSNAME_SIGTERM ? KILL_KILL : KILL_TERMINATE,
 465                               -1,
 466                               n->control_pid,
 467                               false);
 468         if (r < 0) {
 469                 log_unit_warning_errno(UNIT(n), r, "Failed to kill control process: %m");
 470                 goto fail;
 471         }
 472
 473         if (r > 0) {
 474                 r = busname_arm_timer(n, usec_add(now(CLOCK_MONOTONIC), n->timeout_usec));
 475                 if (r < 0) {
 476                         log_unit_warning_errno(UNIT(n), r, "Failed to arm timer: %m");
 477                         goto fail;
 478                 }
 479
 480                 busname_set_state(n, state);
 481         } else if (state == BUSNAME_SIGTERM)
 482                 busname_enter_signal(n, BUSNAME_SIGKILL, BUSNAME_SUCCESS);
 483         else
 484                 busname_enter_dead(n, BUSNAME_SUCCESS);
 485
 486         return;
 487
 488 fail:
 489         busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
 490 }
 491
 492 static void busname_enter_listening(BusName *n) {
 493         int r;
 494
 495         assert(n);
 496
 497         if (n->activating) {
 498                 r = busname_watch_fd(n);
 499                 if (r < 0) {
 500                         log_unit_warning_errno(UNIT(n), r, "Failed to watch names: %m");
 501                         goto fail;
 502                 }
 503
 504                 busname_set_state(n, BUSNAME_LISTENING);
 505         } else
 506                 busname_set_state(n, BUSNAME_REGISTERED);
 507
 508         return;
 509
 510 fail:
 511         busname_enter_signal(n, BUSNAME_SIGTERM, BUSNAME_FAILURE_RESOURCES);
 512 }
 513
 514 static void busname_enter_making(BusName *n) {
 515         int r;
 516
 517         assert(n);
 518
 519         r = busname_open_fd(n);
 520         if (r < 0)
 521                 goto fail;
 522
 523         if (n->policy) {
 524                 /* If there is a policy, we need to resolve user/group
 525                  * names, which we can't do from PID1, hence let's
 526                  * fork. */
 527                 busname_unwatch_control_pid(n);
 528
 529                 r = busname_make_starter(n, &n->control_pid);
 530                 if (r < 0) {
 531                         log_unit_warning_errno(UNIT(n), r, "Failed to fork 'making' task: %m");
 532                         goto fail;
 533                 }
 534
 535                 busname_set_state(n, BUSNAME_MAKING);
 536         } else {
 537                 /* If there is no policy, we can do everything
 538                  * directly from PID 1, hence do so. */
 539
 540                 r = bus_kernel_make_starter(n->starter_fd, n->name, n->activating, n->accept_fd, NULL, n->policy_world);
 541                 if (r < 0) {
 542                         log_unit_warning_errno(UNIT(n), r, "Failed to make starter: %m");
 543                         goto fail;
 544                 }
 545
 546                 busname_enter_listening(n);
 547         }
 548
 549         return;
 550
 551 fail:
 552         busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
 553 }
 554
 555 static void busname_enter_running(BusName *n) {
 556         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 557         bool pending = false;
 558         Unit *other;
 559         Iterator i;
 560         int r;
 561
 562         assert(n);
 563
 564         if (!n->activating)
 565                 return;
 566
 567         /* We don't take connections anymore if we are supposed to
 568          * shut down anyway */
 569
 570         if (unit_stop_pending(UNIT(n))) {
 571                 log_unit_debug(UNIT(n), "Suppressing activation request since unit stop is scheduled.");
 572
 573                 /* Flush all queued activation reqeuest by closing and reopening the connection */
 574                 bus_kernel_drop_one(n->starter_fd);
 575
 576                 busname_enter_listening(n);
 577                 return;
 578         }
 579
 580         /* If there's already a start pending don't bother to do
 581          * anything */
 582         SET_FOREACH(other, UNIT(n)->dependencies[UNIT_TRIGGERS], i)
 583                 if (unit_active_or_pending(other)) {
 584                         pending = true;
 585                         break;
 586                 }
 587
 588         if (!pending) {
 589                 if (!UNIT_ISSET(n->service)) {
 590                         log_unit_error(UNIT(n), "Service to activate vanished, refusing activation.");
 591                         r = -ENOENT;
 592                         goto fail;
 593                 }
 594
 595                 r = manager_add_job(UNIT(n)->manager, JOB_START, UNIT_DEREF(n->service), JOB_REPLACE, &error, NULL);
 596                 if (r < 0)
 597                         goto fail;
 598         }
 599
 600         busname_set_state(n, BUSNAME_RUNNING);
 601         return;
 602
 603 fail:
 604         log_unit_warning(UNIT(n), "Failed to queue service startup job: %s", bus_error_message(&error, r));
 605         busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
 606 }
 607
 608 static int busname_start(Unit *u) {
 609         BusName *n = BUSNAME(u);
 610         int r;
 611
 612         assert(n);
 613
 614         /* We cannot fulfill this request right now, try again later
 615          * please! */
 616         if (IN_SET(n->state, BUSNAME_SIGTERM, BUSNAME_SIGKILL))
 617                 return -EAGAIN;
 618
 619         /* Already on it! */
 620         if (n->state == BUSNAME_MAKING)
 621                 return 0;
 622
 623         if (n->activating && UNIT_ISSET(n->service)) {
 624                 Service *service;
 625
 626                 service = SERVICE(UNIT_DEREF(n->service));
 627
 628                 if (UNIT(service)->load_state != UNIT_LOADED) {
 629                         log_unit_error(u, "Bus service %s not loaded, refusing.", UNIT(service)->id);
 630                         return -ENOENT;
 631                 }
 632         }
 633
 634         assert(IN_SET(n->state, BUSNAME_DEAD, BUSNAME_FAILED));
 635
 636         r = unit_start_limit_test(u);
 637         if (r < 0) {
 638                 busname_enter_dead(n, BUSNAME_FAILURE_START_LIMIT_HIT);
 639                 return r;
 640         }
 641
 642         n->result = BUSNAME_SUCCESS;
 643         busname_enter_making(n);
 644
 645         return 1;
 646 }
 647
 648 static int busname_stop(Unit *u) {
 649         BusName *n = BUSNAME(u);
 650
 651         assert(n);
 652
 653         /* Already on it */
 654         if (IN_SET(n->state, BUSNAME_SIGTERM, BUSNAME_SIGKILL))
 655                 return 0;
 656
 657         /* If there's already something running, we go directly into
 658          * kill mode. */
 659
 660         if (n->state == BUSNAME_MAKING) {
 661                 busname_enter_signal(n, BUSNAME_SIGTERM, BUSNAME_SUCCESS);
 662                 return -EAGAIN;
 663         }
 664
 665         assert(IN_SET(n->state, BUSNAME_REGISTERED, BUSNAME_LISTENING, BUSNAME_RUNNING));
 666
 667         busname_enter_dead(n, BUSNAME_SUCCESS);
 668         return 1;
 669 }
 670
 671 static int busname_serialize(Unit *u, FILE *f, FDSet *fds) {
 672         BusName *n = BUSNAME(u);
 673         int r;
 674
 675         assert(n);
 676         assert(f);
 677         assert(fds);
 678
 679         unit_serialize_item(u, f, "state", busname_state_to_string(n->state));
 680         unit_serialize_item(u, f, "result", busname_result_to_string(n->result));
 681
 682         if (n->control_pid > 0)
 683                 unit_serialize_item_format(u, f, "control-pid", PID_FMT, n->control_pid);
 684
 685         r = unit_serialize_item_fd(u, f, fds, "starter-fd", n->starter_fd);
 686         if (r < 0)
 687                 return r;
 688
 689         return 0;
 690 }
 691
 692 static int busname_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 693         BusName *n = BUSNAME(u);
 694
 695         assert(n);
 696         assert(key);
 697         assert(value);
 698
 699         if (streq(key, "state")) {
 700                 BusNameState state;
 701
 702                 state = busname_state_from_string(value);
 703                 if (state < 0)
 704                         log_unit_debug(u, "Failed to parse state value: %s", value);
 705                 else
 706                         n->deserialized_state = state;
 707
 708         } else if (streq(key, "result")) {
 709                 BusNameResult f;
 710
 711                 f = busname_result_from_string(value);
 712                 if (f < 0)
 713                         log_unit_debug(u, "Failed to parse result value: %s", value);
 714                 else if (f != BUSNAME_SUCCESS)
 715                         n->result = f;
 716
 717         } else if (streq(key, "control-pid")) {
 718                 pid_t pid;
 719
 720                 if (parse_pid(value, &pid) < 0)
 721                         log_unit_debug(u, "Failed to parse control-pid value: %s", value);
 722                 else
 723                         n->control_pid = pid;
 724         } else if (streq(key, "starter-fd")) {
 725                 int fd;
 726
 727                 if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
 728                         log_unit_debug(u, "Failed to parse starter fd value: %s", value);
 729                 else {
 730                         safe_close(n->starter_fd);
 731                         n->starter_fd = fdset_remove(fds, fd);
 732                 }
 733         } else
 734                 log_unit_debug(u, "Unknown serialization key: %s", key);
 735
 736         return 0;
 737 }
 738
 739 _pure_ static UnitActiveState busname_active_state(Unit *u) {
 740         assert(u);
 741
 742         return state_translation_table[BUSNAME(u)->state];
 743 }
 744
 745 _pure_ static const char *busname_sub_state_to_string(Unit *u) {
 746         assert(u);
 747
 748         return busname_state_to_string(BUSNAME(u)->state);
 749 }
 750
 751 static int busname_peek_message(BusName *n) {
 752         struct kdbus_cmd_recv cmd_recv = {
 753                 .size = sizeof(cmd_recv),
 754                 .flags = KDBUS_RECV_PEEK,
 755         };
 756         struct kdbus_cmd_free cmd_free = {
 757                 .size = sizeof(cmd_free),
 758         };
 759         const char *comm = NULL;
 760         struct kdbus_item *d;
 761         struct kdbus_msg *k;
 762         size_t start, ps, sz, delta;
 763         void *p = NULL;
 764         pid_t pid = 0;
 765         int r;
 766
 767         /* Generate a friendly debug log message about which process
 768          * caused triggering of this bus name. This simply peeks the
 769          * metadata of the first queued message and logs it. */
 770
 771         assert(n);
 772
 773         /* Let's shortcut things a bit, if debug logging is turned off
 774          * anyway. */
 775
 776         if (log_get_max_level() < LOG_DEBUG)
 777                 return 0;
 778
 779         r = ioctl(n->starter_fd, KDBUS_CMD_RECV, &cmd_recv);
 780         if (r < 0) {
 781                 if (errno == EINTR || errno == EAGAIN)
 782                         return 0;
 783
 784                 return log_unit_error_errno(UNIT(n), errno, "Failed to query activation message: %m");
 785         }
 786
 787         /* We map as late as possible, and unmap imemdiately after
 788          * use. On 32bit address space is scarce and we want to be
 789          * able to handle a lot of activator connections at the same
 790          * time, and hence shouldn't keep the mmap()s around for
 791          * longer than necessary. */
 792
 793         ps = page_size();
 794         start = (cmd_recv.msg.offset / ps) * ps;
 795         delta = cmd_recv.msg.offset - start;
 796         sz = PAGE_ALIGN(delta + cmd_recv.msg.msg_size);
 797
 798         p = mmap(NULL, sz, PROT_READ, MAP_SHARED, n->starter_fd, start);
 799         if (p == MAP_FAILED) {
 800                 r = log_unit_error_errno(UNIT(n), errno, "Failed to map activation message: %m");
 801                 goto finish;
 802         }
 803
 804         k = (struct kdbus_msg *) ((uint8_t *) p + delta);
 805         KDBUS_ITEM_FOREACH(d, k, items) {
 806                 switch (d->type) {
 807
 808                 case KDBUS_ITEM_PIDS:
 809                         pid = d->pids.pid;
 810                         break;
 811
 812                 case KDBUS_ITEM_PID_COMM:
 813                         comm = d->str;
 814                         break;
 815                 }
 816         }
 817
 818         if (pid > 0)
 819                 log_unit_debug(UNIT(n), "Activation triggered by process " PID_FMT " (%s)", pid, strna(comm));
 820
 821         r = 0;
 822
 823 finish:
 824         if (p)
 825                 (void) munmap(p, sz);
 826
 827         cmd_free.offset = cmd_recv.msg.offset;
 828         if (ioctl(n->starter_fd, KDBUS_CMD_FREE, &cmd_free) < 0)
 829                 log_unit_warning(UNIT(n), "Failed to free peeked message, ignoring: %m");
 830
 831         return r;
 832 }
 833
 834 static int busname_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
 835         BusName *n = userdata;
 836
 837         assert(n);
 838         assert(fd >= 0);
 839
 840         if (n->state != BUSNAME_LISTENING)
 841                 return 0;
 842
 843         log_unit_debug(UNIT(n), "Activation request");
 844
 845         if (revents != EPOLLIN) {
 846                 log_unit_error(UNIT(n), "Got unexpected poll event (0x%x) on starter fd.", revents);
 847                 goto fail;
 848         }
 849
 850         busname_peek_message(n);
 851         busname_enter_running(n);
 852         return 0;
 853 fail:
 854
 855         busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
 856         return 0;
 857 }
 858
 859 static void busname_sigchld_event(Unit *u, pid_t pid, int code, int status) {
 860         BusName *n = BUSNAME(u);
 861         BusNameResult f;
 862
 863         assert(n);
 864         assert(pid >= 0);
 865
 866         if (pid != n->control_pid)
 867                 return;
 868
 869         n->control_pid = 0;
 870
 871         if (is_clean_exit(code, status, NULL))
 872                 f = BUSNAME_SUCCESS;
 873         else if (code == CLD_EXITED)
 874                 f = BUSNAME_FAILURE_EXIT_CODE;
 875         else if (code == CLD_KILLED)
 876                 f = BUSNAME_FAILURE_SIGNAL;
 877         else if (code == CLD_DUMPED)
 878                 f = BUSNAME_FAILURE_CORE_DUMP;
 879         else
 880                 assert_not_reached("Unknown sigchld code");
 881
 882         log_unit_full(u, f == BUSNAME_SUCCESS ? LOG_DEBUG : LOG_NOTICE, 0,
 883                       "Control process exited, code=%s status=%i", sigchld_code_to_string(code), status);
 884
 885         if (f != BUSNAME_SUCCESS)
 886                 n->result = f;
 887
 888         switch (n->state) {
 889
 890         case BUSNAME_MAKING:
 891                 if (f == BUSNAME_SUCCESS)
 892                         busname_enter_listening(n);
 893                 else
 894                         busname_enter_signal(n, BUSNAME_SIGTERM, f);
 895                 break;
 896
 897         case BUSNAME_SIGTERM:
 898         case BUSNAME_SIGKILL:
 899                 busname_enter_dead(n, f);
 900                 break;
 901
 902         default:
 903                 assert_not_reached("Uh, control process died at wrong time.");
 904         }
 905
 906         /* Notify clients about changed exit status */
 907         unit_add_to_dbus_queue(u);
 908 }
 909
 910 static int busname_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
 911         BusName *n = BUSNAME(userdata);
 912
 913         assert(n);
 914         assert(n->timer_event_source == source);
 915
 916         switch (n->state) {
 917
 918         case BUSNAME_MAKING:
 919                 log_unit_warning(UNIT(n), "Making timed out. Terminating.");
 920                 busname_enter_signal(n, BUSNAME_SIGTERM, BUSNAME_FAILURE_TIMEOUT);
 921                 break;
 922
 923         case BUSNAME_SIGTERM:
 924                 log_unit_warning(UNIT(n), "Stopping timed out. Killing.");
 925                 busname_enter_signal(n, BUSNAME_SIGKILL, BUSNAME_FAILURE_TIMEOUT);
 926                 break;
 927
 928         case BUSNAME_SIGKILL:
 929                 log_unit_warning(UNIT(n), "Processes still around after SIGKILL. Ignoring.");
 930                 busname_enter_dead(n, BUSNAME_FAILURE_TIMEOUT);
 931                 break;
 932
 933         default:
 934                 assert_not_reached("Timeout at wrong time.");
 935         }
 936
 937         return 0;
 938 }
 939
 940 static void busname_reset_failed(Unit *u) {
 941         BusName *n = BUSNAME(u);
 942
 943         assert(n);
 944
 945         if (n->state == BUSNAME_FAILED)
 946                 busname_set_state(n, BUSNAME_DEAD);
 947
 948         n->result = BUSNAME_SUCCESS;
 949 }
 950
 951 static void busname_trigger_notify(Unit *u, Unit *other) {
 952         BusName *n = BUSNAME(u);
 953
 954         assert(n);
 955         assert(other);
 956
 957         if (!IN_SET(n->state, BUSNAME_RUNNING, BUSNAME_LISTENING))
 958                 return;
 959
 960         if (other->start_limit_hit) {
 961                 busname_enter_dead(n, BUSNAME_FAILURE_SERVICE_START_LIMIT_HIT);
 962                 return;
 963         }
 964
 965         if (other->load_state != UNIT_LOADED || other->type != UNIT_SERVICE)
 966                 return;
 967
 968         if (IN_SET(SERVICE(other)->state,
 969                    SERVICE_DEAD, SERVICE_FAILED,
 970                    SERVICE_FINAL_SIGTERM, SERVICE_FINAL_SIGKILL,
 971                    SERVICE_AUTO_RESTART))
 972                 busname_enter_listening(n);
 973
 974         if (SERVICE(other)->state == SERVICE_RUNNING)
 975                 busname_set_state(n, BUSNAME_RUNNING);
 976 }
 977
 978 static int busname_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
 979         return unit_kill_common(u, who, signo, -1, BUSNAME(u)->control_pid, error);
 980 }
 981
 982 static int busname_get_timeout(Unit *u, usec_t *timeout) {
 983         BusName *n = BUSNAME(u);
 984         usec_t t;
 985         int r;
 986
 987         if (!n->timer_event_source)
 988                 return 0;
 989
 990         r = sd_event_source_get_time(n->timer_event_source, &t);
 991         if (r < 0)
 992                 return r;
 993         if (t == USEC_INFINITY)
 994                 return 0;
 995
 996         *timeout = t;
 997         return 1;
 998 }
 999
1000 static bool busname_supported(void) {
1001         static int supported = -1;
1002
1003         if (supported < 0)
1004                 supported = is_kdbus_available();
1005
1006         return supported;
1007 }
1008
1009 static int busname_control_pid(Unit *u) {
1010         BusName *n = BUSNAME(u);
1011
1012         assert(n);
1013
1014         return n->control_pid;
1015 }
1016
1017 static const char* const busname_result_table[_BUSNAME_RESULT_MAX] = {
1018         [BUSNAME_SUCCESS] = "success",
1019         [BUSNAME_FAILURE_RESOURCES] = "resources",
1020         [BUSNAME_FAILURE_TIMEOUT] = "timeout",
1021         [BUSNAME_FAILURE_EXIT_CODE] = "exit-code",
1022         [BUSNAME_FAILURE_SIGNAL] = "signal",
1023         [BUSNAME_FAILURE_CORE_DUMP] = "core-dump",
1024         [BUSNAME_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
1025         [BUSNAME_FAILURE_SERVICE_START_LIMIT_HIT] = "service-start-limit-hit",
1026 };
1027
1028 DEFINE_STRING_TABLE_LOOKUP(busname_result, BusNameResult);
1029
1030 const UnitVTable busname_vtable = {
1031         .object_size = sizeof(BusName),
1032
1033         .sections =
1034                 "Unit\0"
1035                 "BusName\0"
1036                 "Install\0",
1037         .private_section = "BusName",
1038
1039         .no_alias = true,
1040         .no_instances = true,
1041
1042         .init = busname_init,
1043         .done = busname_done,
1044         .load = busname_load,
1045
1046         .coldplug = busname_coldplug,
1047
1048         .dump = busname_dump,
1049
1050         .start = busname_start,
1051         .stop = busname_stop,
1052
1053         .kill = busname_kill,
1054
1055         .get_timeout = busname_get_timeout,
1056
1057         .serialize = busname_serialize,
1058         .deserialize_item = busname_deserialize_item,
1059
1060         .active_state = busname_active_state,
1061         .sub_state_to_string = busname_sub_state_to_string,
1062
1063         .sigchld_event = busname_sigchld_event,
1064
1065         .trigger_notify = busname_trigger_notify,
1066
1067         .reset_failed = busname_reset_failed,
1068
1069         .supported = busname_supported,
1070
1071         .control_pid = busname_control_pid,
1072
1073         .bus_vtable = bus_busname_vtable,
1074
1075         .status_message_formats = {
1076                 .finished_start_job = {
1077                         [JOB_DONE]       = "Listening on %s.",
1078                         [JOB_FAILED]     = "Failed to listen on %s.",
1079                 },
1080                 .finished_stop_job = {
1081                         [JOB_DONE]       = "Closed %s.",
1082                         [JOB_FAILED]     = "Failed stopping %s.",
1083                 },
1084         },
1085 };