src/core/busname.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2013 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include "special.h"
  23 #include "bus-kernel.h"
  24 #include "bus-internal.h"
  25 #include "bus-util.h"
  26 #include "service.h"
  27 #include "dbus-busname.h"
  28 #include "busname.h"
  29
  30 static const UnitActiveState state_translation_table[_BUSNAME_STATE_MAX] = {
  31         [BUSNAME_DEAD] = UNIT_INACTIVE,
  32         [BUSNAME_LISTENING] = UNIT_ACTIVE,
  33         [BUSNAME_RUNNING] = UNIT_ACTIVE,
  34         [BUSNAME_FAILED] = UNIT_FAILED
  35 };
  36
  37 static int busname_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
  38
  39 static void busname_init(Unit *u) {
  40         BusName *n = BUSNAME(u);
  41
  42         assert(u);
  43         assert(u->load_state == UNIT_STUB);
  44
  45         n->starter_fd = -1;
  46         n->accept_fd = true;
  47 }
  48
  49 static void busname_done(Unit *u) {
  50         BusName *n = BUSNAME(u);
  51
  52         assert(u);
  53
  54         free(n->name);
  55         n->name = NULL;
  56
  57         unit_ref_unset(&n->service);
  58
  59         n->event_source = sd_event_source_unref(n->event_source);
  60         n->starter_fd = safe_close(n->starter_fd);
  61 }
  62
  63 static int busname_add_default_default_dependencies(BusName *n) {
  64         int r;
  65
  66         assert(n);
  67
  68         r = unit_add_dependency_by_name(UNIT(n), UNIT_BEFORE, SPECIAL_BUSNAMES_TARGET, NULL, true);
  69         if (r < 0)
  70                 return r;
  71
  72         if (UNIT(n)->manager->running_as == SYSTEMD_SYSTEM) {
  73                 r = unit_add_two_dependencies_by_name(UNIT(n), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true);
  74                 if (r < 0)
  75                         return r;
  76         }
  77
  78         return unit_add_two_dependencies_by_name(UNIT(n), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
  79 }
  80
  81 static int busname_add_extras(BusName *n) {
  82         Unit *u = UNIT(n);
  83         int r;
  84
  85         assert(n);
  86
  87         if (!n->name) {
  88                 n->name = unit_name_to_prefix(u->id);
  89                 if (!n->name)
  90                         return -ENOMEM;
  91         }
  92
  93         if (!u->description) {
  94                 r = unit_set_description(u, n->name);
  95                 if (r < 0)
  96                         return r;
  97         }
  98
  99         if (!UNIT_DEREF(n->service)) {
 100                 Unit *x;
 101
 102                 r = unit_load_related_unit(u, ".service", &x);
 103                 if (r < 0)
 104                         return r;
 105
 106                 unit_ref_set(&n->service, x);
 107         }
 108
 109         r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, UNIT_DEREF(n->service), true);
 110         if (r < 0)
 111                 return r;
 112
 113         if (u->default_dependencies) {
 114                 r = busname_add_default_default_dependencies(n);
 115                 if (r < 0)
 116                         return r;
 117         }
 118
 119         return 0;
 120 }
 121
 122 static int busname_verify(BusName *n) {
 123         char *e;
 124
 125         assert(n);
 126
 127         if (UNIT(n)->load_state != UNIT_LOADED)
 128                 return 0;
 129
 130         if (!service_name_is_valid(n->name)) {
 131                 log_error_unit(UNIT(n)->id, "%s's Name= setting is not a valid service name Refusing.", UNIT(n)->id);
 132                 return -EINVAL;
 133         }
 134
 135         e = strappenda(n->name, ".busname");
 136         if (!unit_has_name(UNIT(n), e)) {
 137                 log_error_unit(UNIT(n)->id, "%s's Name= setting doesn't match unit name. Refusing.", UNIT(n)->id);
 138                 return -EINVAL;
 139         }
 140
 141         return 0;
 142 }
 143
 144 static int busname_load(Unit *u) {
 145         BusName *n = BUSNAME(u);
 146         int r;
 147
 148         assert(u);
 149         assert(u->load_state == UNIT_STUB);
 150
 151         r = unit_load_fragment_and_dropin(u);
 152         if (r < 0)
 153                 return r;
 154
 155         if (u->load_state == UNIT_LOADED) {
 156                 /* This is a new unit? Then let's add in some extras */
 157                 r = busname_add_extras(n);
 158                 if (r < 0)
 159                         return r;
 160         }
 161
 162         return busname_verify(n);
 163 }
 164
 165 static void busname_dump(Unit *u, FILE *f, const char *prefix) {
 166         BusName *n = BUSNAME(u);
 167
 168         assert(n);
 169         assert(f);
 170
 171         fprintf(f,
 172                 "%sBus Name State: %s\n"
 173                 "%sResult: %s\n"
 174                 "%sName: %s\n"
 175                 "%sAccept FD: %s\n",
 176                 prefix, busname_state_to_string(n->state),
 177                 prefix, busname_result_to_string(n->result),
 178                 prefix, n->name,
 179                 prefix, yes_no(n->accept_fd));
 180 }
 181
 182 static void busname_unwatch_fd(BusName *n) {
 183         int r;
 184
 185         assert(n);
 186
 187         if (n->event_source) {
 188                 r = sd_event_source_set_enabled(n->event_source, SD_EVENT_OFF);
 189                 if (r < 0)
 190                         log_debug_unit(UNIT(n)->id, "Failed to disable event source.");
 191         }
 192 }
 193
 194 static void busname_close_fd(BusName *n) {
 195         assert(n);
 196
 197         busname_unwatch_fd(n);
 198
 199         if (n->starter_fd <= 0)
 200                 return;
 201
 202         n->starter_fd = safe_close(n->starter_fd);
 203 }
 204
 205 static int busname_watch_fd(BusName *n) {
 206         int r;
 207
 208         assert(n);
 209
 210         if (n->starter_fd < 0)
 211                 return 0;
 212
 213         if (n->event_source)
 214                 r = sd_event_source_set_enabled(n->event_source, SD_EVENT_ON);
 215         else
 216                 r = sd_event_add_io(UNIT(n)->manager->event, &n->event_source, n->starter_fd, EPOLLIN, busname_dispatch_io, n);
 217         if (r < 0) {
 218                 log_warning_unit(UNIT(n)->id, "Failed to watch starter fd: %s", strerror(-r));
 219                 busname_unwatch_fd(n);
 220                 return r;
 221         }
 222
 223         return 0;
 224 }
 225
 226 static int busname_open_fd(BusName *n) {
 227         assert(n);
 228
 229         if (n->starter_fd >= 0)
 230                 return 0;
 231
 232         n->starter_fd = bus_kernel_create_starter(
 233                         UNIT(n)->manager->running_as == SYSTEMD_SYSTEM ? "system" : "user",
 234                         n->name, n->accept_fd, n->policy);
 235
 236         if (n->starter_fd < 0) {
 237                 log_warning_unit(UNIT(n)->id, "Failed to create starter fd: %s", strerror(-n->starter_fd));
 238                 return n->starter_fd;
 239         }
 240
 241         return 0;
 242 }
 243
 244 static void busname_set_state(BusName *n, BusNameState state) {
 245         BusNameState old_state;
 246         assert(n);
 247
 248         old_state = n->state;
 249         n->state = state;
 250
 251         if (state != BUSNAME_LISTENING)
 252                 busname_unwatch_fd(n);
 253
 254         if (!IN_SET(state, BUSNAME_LISTENING, BUSNAME_RUNNING))
 255                 busname_close_fd(n);
 256
 257         if (state != old_state)
 258                 log_debug_unit(UNIT(n)->id, "%s changed %s -> %s",
 259                                UNIT(n)->id, busname_state_to_string(old_state), busname_state_to_string(state));
 260
 261         unit_notify(UNIT(n), state_translation_table[old_state], state_translation_table[state], true);
 262 }
 263
 264 static int busname_coldplug(Unit *u) {
 265         BusName *n = BUSNAME(u);
 266         int r;
 267
 268         assert(n);
 269         assert(n->state == BUSNAME_DEAD);
 270
 271         if (n->deserialized_state == n->state)
 272                 return 0;
 273
 274         if (IN_SET(n->deserialized_state, BUSNAME_LISTENING, BUSNAME_RUNNING)) {
 275                 r = busname_open_fd(n);
 276                 if (r < 0)
 277                         return r;
 278         }
 279
 280         if (n->deserialized_state == BUSNAME_LISTENING) {
 281                 r = busname_watch_fd(n);
 282                 if (r < 0)
 283                         return r;
 284         }
 285
 286         busname_set_state(n, n->deserialized_state);
 287         return 0;
 288 }
 289
 290 static void busname_enter_dead(BusName *n, BusNameResult f) {
 291         assert(n);
 292
 293         if (f != BUSNAME_SUCCESS)
 294                 n->result = f;
 295
 296         busname_set_state(n, n->result != BUSNAME_SUCCESS ? BUSNAME_FAILED : BUSNAME_DEAD);
 297 }
 298
 299 static void busname_enter_listening(BusName *n) {
 300         int r;
 301
 302         assert(n);
 303
 304         r = busname_open_fd(n);
 305         if (r < 0) {
 306                 log_warning_unit(UNIT(n)->id, "%s failed to listen on bus names: %s", UNIT(n)->id, strerror(-r));
 307                 goto fail;
 308         }
 309
 310         r = busname_watch_fd(n);
 311         if (r < 0) {
 312                 log_warning_unit(UNIT(n)->id, "%s failed to watch names: %s", UNIT(n)->id, strerror(-r));
 313                 goto fail;
 314         }
 315
 316         busname_set_state(n, BUSNAME_LISTENING);
 317         return;
 318
 319 fail:
 320         busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
 321 }
 322
 323 static void busname_enter_running(BusName *n) {
 324         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
 325         bool pending = false;
 326         Unit *other;
 327         Iterator i;
 328         int r;
 329
 330         assert(n);
 331
 332         /* We don't take conenctions anymore if we are supposed to
 333          * shut down anyway */
 334
 335         if (unit_stop_pending(UNIT(n))) {
 336                 log_debug_unit(UNIT(n)->id, "Suppressing activation request on %s since unit stop is scheduled.", UNIT(n)->id);
 337
 338                 /* Flush all queued activation reqeuest by closing and reopening the connection */
 339                 bus_kernel_drop_one(n->starter_fd);
 340
 341                 busname_enter_listening(n);
 342                 return;
 343         }
 344
 345         /* If there's already a start pending don't bother to do
 346          * anything */
 347         SET_FOREACH(other, UNIT(n)->dependencies[UNIT_TRIGGERS], i)
 348                 if (unit_active_or_pending(other)) {
 349                         pending = true;
 350                         break;
 351                 }
 352
 353         if (!pending) {
 354                 r = manager_add_job(UNIT(n)->manager, JOB_START, UNIT_DEREF(n->service), JOB_REPLACE, true, &error, NULL);
 355                 if (r < 0)
 356                         goto fail;
 357         }
 358
 359         busname_set_state(n, BUSNAME_RUNNING);
 360         return;
 361
 362 fail:
 363         log_warning_unit(UNIT(n)->id, "%s failed to queue service startup job: %s", UNIT(n)->id, bus_error_message(&error, r));
 364         busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
 365 }
 366
 367 static int busname_start(Unit *u) {
 368         BusName *n = BUSNAME(u);
 369
 370         assert(n);
 371
 372         if (UNIT_ISSET(n->service)) {
 373                 Service *service;
 374
 375                 service = SERVICE(UNIT_DEREF(n->service));
 376
 377                 if (UNIT(service)->load_state != UNIT_LOADED) {
 378                         log_error_unit(u->id, "Bus service %s not loaded, refusing.", UNIT(service)->id);
 379                         return -ENOENT;
 380                 }
 381         }
 382
 383         assert(IN_SET(n->state, BUSNAME_DEAD, BUSNAME_FAILED));
 384
 385         n->result = BUSNAME_SUCCESS;
 386         busname_enter_listening(n);
 387
 388         return 0;
 389 }
 390
 391 static int busname_stop(Unit *u) {
 392         BusName *n = BUSNAME(u);
 393
 394         assert(n);
 395         assert(n->state == BUSNAME_LISTENING || n->state == BUSNAME_RUNNING);
 396
 397         busname_enter_dead(n, BUSNAME_SUCCESS);
 398         return 0;
 399 }
 400
 401 static int busname_serialize(Unit *u, FILE *f, FDSet *fds) {
 402         BusName *n = BUSNAME(u);
 403
 404         assert(n);
 405         assert(f);
 406         assert(fds);
 407
 408         unit_serialize_item(u, f, "state", busname_state_to_string(n->state));
 409         unit_serialize_item(u, f, "result", busname_result_to_string(n->result));
 410
 411         if (n->starter_fd >= 0) {
 412                 int copy;
 413
 414                 copy = fdset_put_dup(fds, n->starter_fd);
 415                 if (copy < 0)
 416                         return copy;
 417
 418                 unit_serialize_item_format(u, f, "starter-fd", "%i", copy);
 419         }
 420
 421         return 0;
 422 }
 423
 424 static int busname_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 425         BusName *n = BUSNAME(u);
 426
 427         assert(n);
 428         assert(key);
 429         assert(value);
 430
 431         if (streq(key, "state")) {
 432                 BusNameState state;
 433
 434                 state = busname_state_from_string(value);
 435                 if (state < 0)
 436                         log_debug_unit(u->id, "Failed to parse state value %s", value);
 437                 else
 438                         n->deserialized_state = state;
 439
 440         } else if (streq(key, "result")) {
 441                 BusNameResult f;
 442
 443                 f = busname_result_from_string(value);
 444                 if (f < 0)
 445                         log_debug_unit(u->id, "Failed to parse result value %s", value);
 446                 else if (f != BUSNAME_SUCCESS)
 447                         n->result = f;
 448
 449         } else if (streq(key, "starter-fd")) {
 450                 int fd;
 451
 452                 if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
 453                         log_debug_unit(u->id, "Failed to parse starter fd value %s", value);
 454                 else {
 455                         safe_close(n->starter_fd);
 456                         n->starter_fd = fdset_remove(fds, fd);
 457                 }
 458         } else
 459                 log_debug_unit(u->id, "Unknown serialization key '%s'", key);
 460
 461         return 0;
 462 }
 463
 464 _pure_ static UnitActiveState busname_active_state(Unit *u) {
 465         assert(u);
 466
 467         return state_translation_table[BUSNAME(u)->state];
 468 }
 469
 470 _pure_ static const char *busname_sub_state_to_string(Unit *u) {
 471         assert(u);
 472
 473         return busname_state_to_string(BUSNAME(u)->state);
 474 }
 475
 476 static int busname_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
 477         BusName *n = userdata;
 478
 479         assert(n);
 480         assert(fd >= 0);
 481
 482         if (n->state != BUSNAME_LISTENING)
 483                 return 0;
 484
 485         log_debug_unit(UNIT(n)->id, "Activation request on %s", UNIT(n)->id);
 486
 487         if (revents != EPOLLIN) {
 488                 log_error_unit(UNIT(n)->id, "%s: Got unexpected poll event (0x%x) on starter fd.",
 489                                UNIT(n)->id, revents);
 490                 goto fail;
 491         }
 492
 493         busname_enter_running(n);
 494         return 0;
 495 fail:
 496
 497         busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
 498         return 0;
 499 }
 500
 501 static void busname_reset_failed(Unit *u) {
 502         BusName *n = BUSNAME(u);
 503
 504         assert(n);
 505
 506         if (n->state == BUSNAME_FAILED)
 507                 busname_set_state(n, BUSNAME_DEAD);
 508
 509         n->result = BUSNAME_SUCCESS;
 510 }
 511
 512 static void busname_trigger_notify(Unit *u, Unit *other) {
 513         BusName *n = BUSNAME(u);
 514         Service *s;
 515
 516         assert(n);
 517         assert(other);
 518
 519         if (!IN_SET(n->state, BUSNAME_RUNNING, BUSNAME_LISTENING))
 520                 return;
 521
 522         if (other->load_state != UNIT_LOADED || other->type != UNIT_SERVICE)
 523                 return;
 524
 525         s = SERVICE(other);
 526
 527         if (s->state == SERVICE_FAILED && s->result == SERVICE_FAILURE_START_LIMIT)
 528                 busname_enter_dead(n, BUSNAME_FAILURE_SERVICE_FAILED_PERMANENT);
 529         else if (IN_SET(s->state,
 530                         SERVICE_DEAD, SERVICE_FAILED,
 531                         SERVICE_STOP, SERVICE_STOP_SIGTERM, SERVICE_STOP_SIGKILL,
 532                         SERVICE_STOP_POST, SERVICE_FINAL_SIGTERM, SERVICE_FINAL_SIGKILL,
 533                         SERVICE_AUTO_RESTART))
 534                 busname_enter_listening(n);
 535 }
 536
 537 static const char* const busname_state_table[_BUSNAME_STATE_MAX] = {
 538         [BUSNAME_DEAD] = "dead",
 539         [BUSNAME_LISTENING] = "listening",
 540         [BUSNAME_RUNNING] = "running",
 541         [BUSNAME_FAILED] = "failed"
 542 };
 543
 544 DEFINE_STRING_TABLE_LOOKUP(busname_state, BusNameState);
 545
 546 static const char* const busname_result_table[_BUSNAME_RESULT_MAX] = {
 547         [BUSNAME_SUCCESS] = "success",
 548         [BUSNAME_FAILURE_RESOURCES] = "resources",
 549         [BUSNAME_FAILURE_SERVICE_FAILED_PERMANENT] = "service-failed-permanent",
 550 };
 551
 552 DEFINE_STRING_TABLE_LOOKUP(busname_result, BusNameResult);
 553
 554 static const char* const busname_policy_access_table[_BUSNAME_POLICY_ACCESS_MAX] = {
 555         [BUSNAME_POLICY_ACCESS_SEE] = "see",
 556         [BUSNAME_POLICY_ACCESS_TALK] = "talk",
 557         [BUSNAME_POLICY_ACCESS_OWN] = "own",
 558 };
 559
 560 DEFINE_STRING_TABLE_LOOKUP(busname_policy_access, BusNamePolicyAccess);
 561
 562 const UnitVTable busname_vtable = {
 563         .object_size = sizeof(BusName),
 564
 565         .sections =
 566                 "Unit\0"
 567                 "BusName\0"
 568                 "Install\0",
 569         .private_section = "BusName",
 570
 571         .init = busname_init,
 572         .done = busname_done,
 573         .load = busname_load,
 574
 575         .coldplug = busname_coldplug,
 576
 577         .dump = busname_dump,
 578
 579         .start = busname_start,
 580         .stop = busname_stop,
 581
 582         .serialize = busname_serialize,
 583         .deserialize_item = busname_deserialize_item,
 584
 585         .active_state = busname_active_state,
 586         .sub_state_to_string = busname_sub_state_to_string,
 587
 588         .trigger_notify = busname_trigger_notify,
 589
 590         .reset_failed = busname_reset_failed,
 591
 592         .bus_interface = "org.freedesktop.systemd1.BusName",
 593         .bus_vtable = bus_busname_vtable,
 594
 595         .status_message_formats = {
 596                 .finished_start_job = {
 597                         [JOB_DONE]       = "Listening on %s.",
 598                         [JOB_FAILED]     = "Failed to listen on %s.",
 599                         [JOB_DEPENDENCY] = "Dependency failed for %s.",
 600                         [JOB_TIMEOUT]    = "Timed out starting %s.",
 601                 },
 602                 .finished_stop_job = {
 603                         [JOB_DONE]       = "Closed %s.",
 604                         [JOB_FAILED]     = "Failed stopping %s.",
 605                         [JOB_TIMEOUT]    = "Timed out stopping %s.",
 606                 },
 607         },
 608 };