manager.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 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   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <assert.h>
  23 #include <errno.h>
  24 #include <string.h>
  25 #include <sys/epoll.h>
  26 #include <signal.h>
  27 #include <sys/signalfd.h>
  28 #include <sys/wait.h>
  29 #include <unistd.h>
  30 #include <utmpx.h>
  31 #include <sys/poll.h>
  32 #include <sys/reboot.h>
  33 #include <sys/ioctl.h>
  34 #include <linux/kd.h>
  35 #include <libcgroup.h>
  36
  37 #include "manager.h"
  38 #include "hashmap.h"
  39 #include "macro.h"
  40 #include "strv.h"
  41 #include "log.h"
  42 #include "util.h"
  43 #include "ratelimit.h"
  44 #include "cgroup.h"
  45 #include "mount-setup.h"
  46 #include "utmp-wtmp.h"
  47
  48 static int manager_setup_signals(Manager *m) {
  49         sigset_t mask;
  50         struct epoll_event ev;
  51
  52         assert(m);
  53
  54         assert_se(sigemptyset(&mask) == 0);
  55         assert_se(sigaddset(&mask, SIGCHLD) == 0);
  56         assert_se(sigaddset(&mask, SIGINT) == 0);   /* Kernel sends us this on control-alt-del */
  57         assert_se(sigaddset(&mask, SIGWINCH) == 0); /* Kernel sends us this on kbrequest (alt-arrowup) */
  58         assert_se(sigaddset(&mask, SIGTERM) == 0);
  59         assert_se(sigaddset(&mask, SIGHUP) == 0);
  60         assert_se(sigaddset(&mask, SIGUSR1) == 0);
  61         assert_se(sigaddset(&mask, SIGUSR2) == 0);
  62         assert_se(sigaddset(&mask, SIGPWR) == 0);
  63         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
  64
  65         m->signal_watch.type = WATCH_SIGNAL;
  66         if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
  67                 return -errno;
  68
  69         zero(ev);
  70         ev.events = EPOLLIN;
  71         ev.data.ptr = &m->signal_watch;
  72
  73         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
  74                 return -errno;
  75
  76         if (m->running_as == MANAGER_INIT) {
  77                 /* Enable that we get SIGINT on control-alt-del */
  78                 if (reboot(RB_DISABLE_CAD) < 0)
  79                         log_warning("Failed to enable ctrl-alt-del handling: %s", strerror(errno));
  80
  81                 /* Enable that we get SIGWINCH on kbrequest */
  82                 if (ioctl(0, KDSIGACCEPT, SIGWINCH) < 0)
  83                         log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
  84         }
  85
  86         return 0;
  87 }
  88
  89 static char** session_dirs(void) {
  90         const char *home, *e;
  91         char *config_home = NULL, *data_home = NULL;
  92         char **config_dirs = NULL, **data_dirs = NULL;
  93         char **r = NULL, **t;
  94
  95         /* Implement the mechanisms defined in
  96          *
  97          * http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
  98          *
  99          * We look in both the config and the data dirs because we
 100          * want to encourage that distributors ship their unit files
 101          * as data, and allow overriding as configuration.
 102          */
 103
 104         home = getenv("HOME");
 105
 106         if ((e = getenv("XDG_CONFIG_HOME"))) {
 107                 if (asprintf(&config_home, "%s/systemd/session", e) < 0)
 108                         goto fail;
 109
 110         } else if (home) {
 111                 if (asprintf(&config_home, "%s/.config/systemd/session", home) < 0)
 112                         goto fail;
 113         }
 114
 115         if ((e = getenv("XDG_CONFIG_DIRS")))
 116                 config_dirs = strv_split(e, ":");
 117         else
 118                 config_dirs = strv_new("/etc/xdg", NULL);
 119
 120         if (!config_dirs)
 121                 goto fail;
 122
 123         if ((e = getenv("XDG_DATA_HOME"))) {
 124                 if (asprintf(&data_home, "%s/systemd/session", e) < 0)
 125                         goto fail;
 126
 127         } else if (home) {
 128                 if (asprintf(&data_home, "%s/.local/share/systemd/session", home) < 0)
 129                         goto fail;
 130         }
 131
 132         if ((e = getenv("XDG_DATA_DIRS")))
 133                 data_dirs = strv_split(e, ":");
 134         else
 135                 data_dirs = strv_new("/usr/local/share", "/usr/share", NULL);
 136
 137         if (!data_dirs)
 138                 goto fail;
 139
 140         /* Now merge everything we found. */
 141         if (config_home) {
 142                 if (!(t = strv_append(r, config_home)))
 143                         goto fail;
 144                 strv_free(r);
 145                 r = t;
 146         }
 147
 148         if (!(t = strv_merge_concat(r, config_dirs, "/systemd/session")))
 149                 goto finish;
 150         strv_free(r);
 151         r = t;
 152
 153         if (!(t = strv_append(r, SESSION_CONFIG_UNIT_PATH)))
 154                 goto fail;
 155         strv_free(r);
 156         r = t;
 157
 158         if (data_home) {
 159                 if (!(t = strv_append(r, data_home)))
 160                         goto fail;
 161                 strv_free(r);
 162                 r = t;
 163         }
 164
 165         if (!(t = strv_merge_concat(r, data_dirs, "/systemd/session")))
 166                 goto fail;
 167         strv_free(r);
 168         r = t;
 169
 170         if (!(t = strv_append(r, SESSION_DATA_UNIT_PATH)))
 171                 goto fail;
 172         strv_free(r);
 173         r = t;
 174
 175         if (!strv_path_make_absolute_cwd(r))
 176             goto fail;
 177
 178 finish:
 179         free(config_home);
 180         strv_free(config_dirs);
 181         free(data_home);
 182         strv_free(data_dirs);
 183
 184         return r;
 185
 186 fail:
 187         strv_free(r);
 188         r = NULL;
 189         goto finish;
 190 }
 191
 192 static int manager_find_paths(Manager *m) {
 193         const char *e;
 194         char *t;
 195
 196         assert(m);
 197
 198         /* First priority is whatever has been passed to us via env
 199          * vars */
 200         if ((e = getenv("SYSTEMD_UNIT_PATH")))
 201                 if (!(m->unit_path = split_path_and_make_absolute(e)))
 202                         return -ENOMEM;
 203
 204         if (strv_isempty(m->unit_path)) {
 205
 206                 /* Nothing is set, so let's figure something out. */
 207                 strv_free(m->unit_path);
 208
 209                 if (m->running_as == MANAGER_SESSION) {
 210                         if (!(m->unit_path = session_dirs()))
 211                                 return -ENOMEM;
 212                 } else
 213                         if (!(m->unit_path = strv_new(
 214                                               SYSTEM_CONFIG_UNIT_PATH,  /* /etc/systemd/system/ */
 215                                               SYSTEM_DATA_UNIT_PATH,    /* /lib/systemd/system/ */
 216                                               NULL)))
 217                                 return -ENOMEM;
 218         }
 219
 220         if (m->running_as == MANAGER_INIT) {
 221                 /* /etc/init.d/ compativility does not matter to users */
 222
 223                 if ((e = getenv("SYSTEMD_SYSVINIT_PATH")))
 224                         if (!(m->sysvinit_path = split_path_and_make_absolute(e)))
 225                                 return -ENOMEM;
 226
 227                 if (strv_isempty(m->sysvinit_path)) {
 228                         strv_free(m->sysvinit_path);
 229
 230                         if (!(m->sysvinit_path = strv_new(
 231                                               SYSTEM_SYSVINIT_PATH,     /* /etc/init.d/ */
 232                                               NULL)))
 233                                 return -ENOMEM;
 234                 }
 235
 236                 if ((e = getenv("SYSTEMD_SYSVRCND_PATH")))
 237                         if (!(m->sysvrcnd_path = split_path_and_make_absolute(e)))
 238                                 return -ENOMEM;
 239
 240                 if (strv_isempty(m->sysvrcnd_path)) {
 241                         strv_free(m->sysvrcnd_path);
 242
 243                         if (!(m->sysvrcnd_path = strv_new(
 244                                               SYSTEM_SYSVRCND_PATH,     /* /etc/rcN.d/ */
 245                                               NULL)))
 246                                 return -ENOMEM;
 247                 }
 248         }
 249
 250         strv_uniq(m->unit_path);
 251         strv_uniq(m->sysvinit_path);
 252         strv_uniq(m->sysvrcnd_path);
 253
 254         assert(!strv_isempty(m->unit_path));
 255         if (!(t = strv_join(m->unit_path, "\n\t")))
 256                 return -ENOMEM;
 257         log_debug("Looking for unit files in:\n\t%s", t);
 258         free(t);
 259
 260         if (!strv_isempty(m->sysvinit_path)) {
 261
 262                 if (!(t = strv_join(m->sysvinit_path, "\n\t")))
 263                         return -ENOMEM;
 264
 265                 log_debug("Looking for SysV init scripts in:\n\t%s", t);
 266                 free(t);
 267         } else
 268                 log_debug("Ignoring SysV init scripts.");
 269
 270         if (!strv_isempty(m->sysvrcnd_path)) {
 271
 272                 if (!(t = strv_join(m->sysvrcnd_path, "\n\t")))
 273                         return -ENOMEM;
 274
 275                 log_debug("Looking for SysV rcN.d links in:\n\t%s", t);
 276                 free(t);
 277         } else
 278                 log_debug("Ignoring SysV rcN.d links.");
 279
 280         return 0;
 281 }
 282
 283 int manager_new(ManagerRunningAs running_as, Manager **_m) {
 284         Manager *m;
 285         int r = -ENOMEM;
 286
 287         assert(_m);
 288         assert(running_as >= 0);
 289         assert(running_as < _MANAGER_RUNNING_AS_MAX);
 290
 291         if (!(m = new0(Manager, 1)))
 292                 return -ENOMEM;
 293
 294         m->boot_timestamp = now(CLOCK_REALTIME);
 295
 296         m->running_as = running_as;
 297         m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = -1;
 298         m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
 299
 300         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
 301                 goto fail;
 302
 303         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 304                 goto fail;
 305
 306         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 307                 goto fail;
 308
 309         if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
 310                 goto fail;
 311
 312         if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
 313                 goto fail;
 314
 315         if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
 316                 goto fail;
 317
 318         if ((r = manager_find_paths(m)) < 0)
 319                 goto fail;
 320
 321         if ((r = manager_setup_signals(m)) < 0)
 322                 goto fail;
 323
 324         if ((r = manager_setup_cgroup(m)) < 0)
 325                 goto fail;
 326
 327         /* Try to connect to the busses, if possible. */
 328         if ((r = bus_init_system(m)) < 0 ||
 329             (r = bus_init_api(m)) < 0)
 330                 goto fail;
 331
 332         *_m = m;
 333         return 0;
 334
 335 fail:
 336         manager_free(m);
 337         return r;
 338 }
 339
 340 static unsigned manager_dispatch_cleanup_queue(Manager *m) {
 341         Meta *meta;
 342         unsigned n = 0;
 343
 344         assert(m);
 345
 346         while ((meta = m->cleanup_queue)) {
 347                 assert(meta->in_cleanup_queue);
 348
 349                 unit_free(UNIT(meta));
 350                 n++;
 351         }
 352
 353         return n;
 354 }
 355
 356 void manager_free(Manager *m) {
 357         UnitType c;
 358         Unit *u;
 359         Job *j;
 360
 361         assert(m);
 362
 363         while ((j = hashmap_first(m->transaction_jobs)))
 364                 job_free(j);
 365
 366         while ((u = hashmap_first(m->units)))
 367                 unit_free(u);
 368
 369         manager_dispatch_cleanup_queue(m);
 370
 371         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 372                 if (unit_vtable[c]->shutdown)
 373                         unit_vtable[c]->shutdown(m);
 374
 375         manager_shutdown_cgroup(m);
 376
 377         bus_done_api(m);
 378         bus_done_system(m);
 379
 380         hashmap_free(m->units);
 381         hashmap_free(m->jobs);
 382         hashmap_free(m->transaction_jobs);
 383         hashmap_free(m->watch_pids);
 384
 385         if (m->epoll_fd >= 0)
 386                 close_nointr(m->epoll_fd);
 387         if (m->signal_watch.fd >= 0)
 388                 close_nointr(m->signal_watch.fd);
 389
 390         strv_free(m->unit_path);
 391         strv_free(m->sysvinit_path);
 392         strv_free(m->sysvrcnd_path);
 393
 394         free(m->cgroup_controller);
 395         free(m->cgroup_hierarchy);
 396
 397         assert(hashmap_isempty(m->cgroup_bondings));
 398         hashmap_free(m->cgroup_bondings);
 399
 400         free(m);
 401 }
 402
 403 int manager_coldplug(Manager *m) {
 404         int r;
 405         UnitType c;
 406         Iterator i;
 407         Unit *u;
 408         char *k;
 409
 410         assert(m);
 411
 412         /* First, let's ask every type to load all units from
 413          * disk/kernel that it might know */
 414         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 415                 if (unit_vtable[c]->enumerate)
 416                         if ((r = unit_vtable[c]->enumerate(m)) < 0)
 417                                 return r;
 418
 419         manager_dispatch_load_queue(m);
 420
 421         /* Then, let's set up their initial state. */
 422         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 423
 424                 /* ignore aliases */
 425                 if (unit_id(u) != k)
 426                         continue;
 427
 428                 if (UNIT_VTABLE(u)->coldplug)
 429                         if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
 430                                 return r;
 431         }
 432
 433         /* Now that the initial devices are available, let's see if we
 434          * can write the utmp file */
 435         manager_write_utmp_reboot(m);
 436
 437         return 0;
 438 }
 439
 440 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
 441         assert(m);
 442         assert(j);
 443
 444         /* Deletes one job from the transaction */
 445
 446         manager_transaction_unlink_job(m, j, delete_dependencies);
 447
 448         if (!j->installed)
 449                 job_free(j);
 450 }
 451
 452 static void transaction_delete_unit(Manager *m, Unit *u) {
 453         Job *j;
 454
 455         /* Deletes all jobs associated with a certain unit from the
 456          * transaction */
 457
 458         while ((j = hashmap_get(m->transaction_jobs, u)))
 459                 transaction_delete_job(m, j, true);
 460 }
 461
 462 static void transaction_clean_dependencies(Manager *m) {
 463         Iterator i;
 464         Job *j;
 465
 466         assert(m);
 467
 468         /* Drops all dependencies of all installed jobs */
 469
 470         HASHMAP_FOREACH(j, m->jobs, i) {
 471                 while (j->subject_list)
 472                         job_dependency_free(j->subject_list);
 473                 while (j->object_list)
 474                         job_dependency_free(j->object_list);
 475         }
 476
 477         assert(!m->transaction_anchor);
 478 }
 479
 480 static void transaction_abort(Manager *m) {
 481         Job *j;
 482
 483         assert(m);
 484
 485         while ((j = hashmap_first(m->transaction_jobs)))
 486                 if (j->installed)
 487                         transaction_delete_job(m, j, true);
 488                 else
 489                         job_free(j);
 490
 491         assert(hashmap_isempty(m->transaction_jobs));
 492
 493         transaction_clean_dependencies(m);
 494 }
 495
 496 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 497         JobDependency *l;
 498
 499         assert(m);
 500
 501         /* A recursive sweep through the graph that marks all units
 502          * that matter to the anchor job, i.e. are directly or
 503          * indirectly a dependency of the anchor job via paths that
 504          * are fully marked as mattering. */
 505
 506         if (j)
 507                 l = j->subject_list;
 508         else
 509                 l = m->transaction_anchor;
 510
 511         LIST_FOREACH(subject, l, l) {
 512
 513                 /* This link does not matter */
 514                 if (!l->matters)
 515                         continue;
 516
 517                 /* This unit has already been marked */
 518                 if (l->object->generation == generation)
 519                         continue;
 520
 521                 l->object->matters_to_anchor = true;
 522                 l->object->generation = generation;
 523
 524                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 525         }
 526 }
 527
 528 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 529         JobDependency *l, *last;
 530
 531         assert(j);
 532         assert(other);
 533         assert(j->unit == other->unit);
 534         assert(!j->installed);
 535
 536         /* Merges 'other' into 'j' and then deletes j. */
 537
 538         j->type = t;
 539         j->state = JOB_WAITING;
 540         j->forced = j->forced || other->forced;
 541
 542         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 543
 544         /* Patch us in as new owner of the JobDependency objects */
 545         last = NULL;
 546         LIST_FOREACH(subject, l, other->subject_list) {
 547                 assert(l->subject == other);
 548                 l->subject = j;
 549                 last = l;
 550         }
 551
 552         /* Merge both lists */
 553         if (last) {
 554                 last->subject_next = j->subject_list;
 555                 if (j->subject_list)
 556                         j->subject_list->subject_prev = last;
 557                 j->subject_list = other->subject_list;
 558         }
 559
 560         /* Patch us in as new owner of the JobDependency objects */
 561         last = NULL;
 562         LIST_FOREACH(object, l, other->object_list) {
 563                 assert(l->object == other);
 564                 l->object = j;
 565                 last = l;
 566         }
 567
 568         /* Merge both lists */
 569         if (last) {
 570                 last->object_next = j->object_list;
 571                 if (j->object_list)
 572                         j->object_list->object_prev = last;
 573                 j->object_list = other->object_list;
 574         }
 575
 576         /* Kill the other job */
 577         other->subject_list = NULL;
 578         other->object_list = NULL;
 579         transaction_delete_job(m, other, true);
 580 }
 581
 582 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 583         Job *k;
 584
 585         assert(j);
 586
 587         /* Tries to delete one item in the linked list
 588          * j->transaction_next->transaction_next->... that conflicts
 589          * whith another one, in an attempt to make an inconsistent
 590          * transaction work. */
 591
 592         /* We rely here on the fact that if a merged with b does not
 593          * merge with c, either a or b merge with c neither */
 594         LIST_FOREACH(transaction, j, j)
 595                 LIST_FOREACH(transaction, k, j->transaction_next) {
 596                         Job *d;
 597
 598                         /* Is this one mergeable? Then skip it */
 599                         if (job_type_is_mergeable(j->type, k->type))
 600                                 continue;
 601
 602                         /* Ok, we found two that conflict, let's see if we can
 603                          * drop one of them */
 604                         if (!j->matters_to_anchor)
 605                                 d = j;
 606                         else if (!k->matters_to_anchor)
 607                                 d = k;
 608                         else
 609                                 return -ENOEXEC;
 610
 611                         /* Ok, we can drop one, so let's do so. */
 612                         log_debug("Trying to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
 613                         transaction_delete_job(m, d, true);
 614                         return 0;
 615                 }
 616
 617         return -EINVAL;
 618 }
 619
 620 static int transaction_merge_jobs(Manager *m) {
 621         Job *j;
 622         Iterator i;
 623         int r;
 624
 625         assert(m);
 626
 627         /* First step, check whether any of the jobs for one specific
 628          * task conflict. If so, try to drop one of them. */
 629         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 630                 JobType t;
 631                 Job *k;
 632
 633                 t = j->type;
 634                 LIST_FOREACH(transaction, k, j->transaction_next) {
 635                         if ((r = job_type_merge(&t, k->type)) >= 0)
 636                                 continue;
 637
 638                         /* OK, we could not merge all jobs for this
 639                          * action. Let's see if we can get rid of one
 640                          * of them */
 641
 642                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 643                                 /* Ok, we managed to drop one, now
 644                                  * let's ask our callers to call us
 645                                  * again after garbage collecting */
 646                                 return -EAGAIN;
 647
 648                         /* We couldn't merge anything. Failure */
 649                         return r;
 650                 }
 651         }
 652
 653         /* Second step, merge the jobs. */
 654         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 655                 JobType t = j->type;
 656                 Job *k;
 657
 658                 /* Merge all transactions */
 659                 LIST_FOREACH(transaction, k, j->transaction_next)
 660                         assert_se(job_type_merge(&t, k->type) == 0);
 661
 662                 /* If an active job is mergeable, merge it too */
 663                 if (j->unit->meta.job)
 664                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 665
 666                 while ((k = j->transaction_next)) {
 667                         if (j->installed) {
 668                                 transaction_merge_and_delete_job(m, k, j, t);
 669                                 j = k;
 670                         } else
 671                                 transaction_merge_and_delete_job(m, j, k, t);
 672                 }
 673
 674                 assert(!j->transaction_next);
 675                 assert(!j->transaction_prev);
 676         }
 677
 678         return 0;
 679 }
 680
 681 static void transaction_drop_redundant(Manager *m) {
 682         bool again;
 683
 684         assert(m);
 685
 686         /* Goes through the transaction and removes all jobs that are
 687          * a noop */
 688
 689         do {
 690                 Job *j;
 691                 Iterator i;
 692
 693                 again = false;
 694
 695                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 696                         bool changes_something = false;
 697                         Job *k;
 698
 699                         LIST_FOREACH(transaction, k, j) {
 700
 701                                 if (!job_is_anchor(k) &&
 702                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
 703                                         continue;
 704
 705                                 changes_something = true;
 706                                 break;
 707                         }
 708
 709                         if (changes_something)
 710                                 continue;
 711
 712                         log_debug("Found redundant job %s/%s, dropping.", unit_id(j->unit), job_type_to_string(j->type));
 713                         transaction_delete_job(m, j, false);
 714                         again = true;
 715                         break;
 716                 }
 717
 718         } while (again);
 719 }
 720
 721 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 722         assert(u);
 723         assert(!j->transaction_prev);
 724
 725         /* Checks whether at least one of the jobs for this unit
 726          * matters to the anchor. */
 727
 728         LIST_FOREACH(transaction, j, j)
 729                 if (j->matters_to_anchor)
 730                         return true;
 731
 732         return false;
 733 }
 734
 735 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
 736         Iterator i;
 737         Unit *u;
 738         int r;
 739
 740         assert(m);
 741         assert(j);
 742         assert(!j->transaction_prev);
 743
 744         /* Does a recursive sweep through the ordering graph, looking
 745          * for a cycle. If we find cycle we try to break it. */
 746
 747         /* Did we find a cycle? */
 748         if (j->marker && j->generation == generation) {
 749                 Job *k;
 750
 751                 /* So, we already have been here. We have a
 752                  * cycle. Let's try to break it. We go backwards in
 753                  * our path and try to find a suitable job to
 754                  * remove. We use the marker to find our way back,
 755                  * since smart how we are we stored our way back in
 756                  * there. */
 757
 758                 log_debug("Found ordering cycle on %s/%s", unit_id(j->unit), job_type_to_string(j->type));
 759
 760                 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
 761
 762                         log_debug("Walked on cycle path to %s/%s", unit_id(k->unit), job_type_to_string(k->type));
 763
 764                         if (!k->installed &&
 765                             !unit_matters_to_anchor(k->unit, k)) {
 766                                 /* Ok, we can drop this one, so let's
 767                                  * do so. */
 768                                 log_debug("Breaking order cycle by deleting job %s/%s", unit_id(k->unit), job_type_to_string(k->type));
 769                                 transaction_delete_unit(m, k->unit);
 770                                 return -EAGAIN;
 771                         }
 772
 773                         /* Check if this in fact was the beginning of
 774                          * the cycle */
 775                         if (k == j)
 776                                 break;
 777                 }
 778
 779                 log_debug("Unable to break cycle");
 780
 781                 return -ENOEXEC;
 782         }
 783
 784         /* Make the marker point to where we come from, so that we can
 785          * find our way backwards if we want to break a cycle */
 786         j->marker = from;
 787         j->generation = generation;
 788
 789         /* We assume that the the dependencies are bidirectional, and
 790          * hence can ignore UNIT_AFTER */
 791         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
 792                 Job *o;
 793
 794                 /* Is there a job for this unit? */
 795                 if (!(o = hashmap_get(m->transaction_jobs, u)))
 796
 797                         /* Ok, there is no job for this in the
 798                          * transaction, but maybe there is already one
 799                          * running? */
 800                         if (!(o = u->meta.job))
 801                                 continue;
 802
 803                 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
 804                         return r;
 805         }
 806
 807         /* Ok, let's backtrack, and remember that this entry is not on
 808          * our path anymore. */
 809         j->marker = NULL;
 810
 811         return 0;
 812 }
 813
 814 static int transaction_verify_order(Manager *m, unsigned *generation) {
 815         Job *j;
 816         int r;
 817         Iterator i;
 818
 819         assert(m);
 820         assert(generation);
 821
 822         /* Check if the ordering graph is cyclic. If it is, try to fix
 823          * that up by dropping one of the jobs. */
 824
 825         HASHMAP_FOREACH(j, m->transaction_jobs, i)
 826                 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
 827                         return r;
 828
 829         return 0;
 830 }
 831
 832 static void transaction_collect_garbage(Manager *m) {
 833         bool again;
 834
 835         assert(m);
 836
 837         /* Drop jobs that are not required by any other job */
 838
 839         do {
 840                 Iterator i;
 841                 Job *j;
 842
 843                 again = false;
 844
 845                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 846                         if (j->object_list)
 847                                 continue;
 848
 849                         log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type));
 850                         transaction_delete_job(m, j, true);
 851                         again = true;
 852                         break;
 853                 }
 854
 855         } while (again);
 856 }
 857
 858 static int transaction_is_destructive(Manager *m, JobMode mode) {
 859         Iterator i;
 860         Job *j;
 861
 862         assert(m);
 863
 864         /* Checks whether applying this transaction means that
 865          * existing jobs would be replaced */
 866
 867         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 868
 869                 /* Assume merged */
 870                 assert(!j->transaction_prev);
 871                 assert(!j->transaction_next);
 872
 873                 if (j->unit->meta.job &&
 874                     j->unit->meta.job != j &&
 875                     !job_type_is_superset(j->type, j->unit->meta.job->type))
 876                         return -EEXIST;
 877         }
 878
 879         return 0;
 880 }
 881
 882 static void transaction_minimize_impact(Manager *m) {
 883         bool again;
 884         assert(m);
 885
 886         /* Drops all unnecessary jobs that reverse already active jobs
 887          * or that stop a running service. */
 888
 889         do {
 890                 Job *j;
 891                 Iterator i;
 892
 893                 again = false;
 894
 895                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 896                         LIST_FOREACH(transaction, j, j) {
 897                                 bool stops_running_service, changes_existing_job;
 898
 899                                 /* If it matters, we shouldn't drop it */
 900                                 if (j->matters_to_anchor)
 901                                         continue;
 902
 903                                 /* Would this stop a running service?
 904                                  * Would this change an existing job?
 905                                  * If so, let's drop this entry */
 906
 907                                 stops_running_service =
 908                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
 909
 910                                 changes_existing_job =
 911                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
 912
 913                                 if (!stops_running_service && !changes_existing_job)
 914                                         continue;
 915
 916                                 if (stops_running_service)
 917                                         log_debug("%s/%s would stop a running service.", unit_id(j->unit), job_type_to_string(j->type));
 918
 919                                 if (changes_existing_job)
 920                                         log_debug("%s/%s would change existing job.", unit_id(j->unit), job_type_to_string(j->type));
 921
 922                                 /* Ok, let's get rid of this */
 923                                 log_debug("Deleting %s/%s to minimize impact.", unit_id(j->unit), job_type_to_string(j->type));
 924
 925                                 transaction_delete_job(m, j, true);
 926                                 again = true;
 927                                 break;
 928                         }
 929
 930                         if (again)
 931                                 break;
 932                 }
 933
 934         } while (again);
 935 }
 936
 937 static int transaction_apply(Manager *m, JobMode mode) {
 938         Iterator i;
 939         Job *j;
 940         int r;
 941
 942         /* Moves the transaction jobs to the set of active jobs */
 943
 944         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 945                 /* Assume merged */
 946                 assert(!j->transaction_prev);
 947                 assert(!j->transaction_next);
 948
 949                 if (j->installed)
 950                         continue;
 951
 952                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
 953                         goto rollback;
 954         }
 955
 956         while ((j = hashmap_steal_first(m->transaction_jobs))) {
 957                 if (j->installed)
 958                         continue;
 959
 960                 if (j->unit->meta.job)
 961                         job_free(j->unit->meta.job);
 962
 963                 j->unit->meta.job = j;
 964                 j->installed = true;
 965
 966                 /* We're fully installed. Now let's free data we don't
 967                  * need anymore. */
 968
 969                 assert(!j->transaction_next);
 970                 assert(!j->transaction_prev);
 971
 972                 job_add_to_run_queue(j);
 973                 job_add_to_dbus_queue(j);
 974         }
 975
 976         /* As last step, kill all remaining job dependencies. */
 977         transaction_clean_dependencies(m);
 978
 979         return 0;
 980
 981 rollback:
 982
 983         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 984                 if (j->installed)
 985                         continue;
 986
 987                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
 988         }
 989
 990         return r;
 991 }
 992
 993 static int transaction_activate(Manager *m, JobMode mode) {
 994         int r;
 995         unsigned generation = 1;
 996
 997         assert(m);
 998
 999         /* This applies the changes recorded in transaction_jobs to
1000          * the actual list of jobs, if possible. */
1001
1002         /* First step: figure out which jobs matter */
1003         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1004
1005         /* Second step: Try not to stop any running services if
1006          * we don't have to. Don't try to reverse running
1007          * jobs if we don't have to. */
1008         transaction_minimize_impact(m);
1009
1010         /* Third step: Drop redundant jobs */
1011         transaction_drop_redundant(m);
1012
1013         for (;;) {
1014                 /* Fourth step: Let's remove unneeded jobs that might
1015                  * be lurking. */
1016                 transaction_collect_garbage(m);
1017
1018                 /* Fifth step: verify order makes sense and correct
1019                  * cycles if necessary and possible */
1020                 if ((r = transaction_verify_order(m, &generation)) >= 0)
1021                         break;
1022
1023                 if (r != -EAGAIN) {
1024                         log_debug("Requested transaction contains an unfixable cyclic ordering dependency: %s", strerror(-r));
1025                         goto rollback;
1026                 }
1027
1028                 /* Let's see if the resulting transaction ordering
1029                  * graph is still cyclic... */
1030         }
1031
1032         for (;;) {
1033                 /* Sixth step: let's drop unmergeable entries if
1034                  * necessary and possible, merge entries we can
1035                  * merge */
1036                 if ((r = transaction_merge_jobs(m)) >= 0)
1037                         break;
1038
1039                 if (r != -EAGAIN) {
1040                         log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r));
1041                         goto rollback;
1042                 }
1043
1044                 /* Seventh step: an entry got dropped, let's garbage
1045                  * collect its dependencies. */
1046                 transaction_collect_garbage(m);
1047
1048                 /* Let's see if the resulting transaction still has
1049                  * unmergeable entries ... */
1050         }
1051
1052         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1053         transaction_drop_redundant(m);
1054
1055         /* Ninth step: check whether we can actually apply this */
1056         if (mode == JOB_FAIL)
1057                 if ((r = transaction_is_destructive(m, mode)) < 0) {
1058                         log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
1059                         goto rollback;
1060                 }
1061
1062         /* Tenth step: apply changes */
1063         if ((r = transaction_apply(m, mode)) < 0) {
1064                 log_debug("Failed to apply transaction: %s", strerror(-r));
1065                 goto rollback;
1066         }
1067
1068         assert(hashmap_isempty(m->transaction_jobs));
1069         assert(!m->transaction_anchor);
1070
1071         return 0;
1072
1073 rollback:
1074         transaction_abort(m);
1075         return r;
1076 }
1077
1078 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) {
1079         Job *j, *f;
1080         int r;
1081
1082         assert(m);
1083         assert(unit);
1084
1085         /* Looks for an axisting prospective job and returns that. If
1086          * it doesn't exist it is created and added to the prospective
1087          * jobs list. */
1088
1089         f = hashmap_get(m->transaction_jobs, unit);
1090
1091         LIST_FOREACH(transaction, j, f) {
1092                 assert(j->unit == unit);
1093
1094                 if (j->type == type) {
1095                         if (is_new)
1096                                 *is_new = false;
1097                         return j;
1098                 }
1099         }
1100
1101         if (unit->meta.job && unit->meta.job->type == type)
1102                 j = unit->meta.job;
1103         else if (!(j = job_new(m, type, unit)))
1104                 return NULL;
1105
1106         j->generation = 0;
1107         j->marker = NULL;
1108         j->matters_to_anchor = false;
1109         j->forced = force;
1110
1111         LIST_PREPEND(Job, transaction, f, j);
1112
1113         if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
1114                 job_free(j);
1115                 return NULL;
1116         }
1117
1118         if (is_new)
1119                 *is_new = true;
1120
1121         log_debug("Added job %s/%s to transaction.", unit_id(unit), job_type_to_string(type));
1122
1123         return j;
1124 }
1125
1126 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1127         assert(m);
1128         assert(j);
1129
1130         if (j->transaction_prev)
1131                 j->transaction_prev->transaction_next = j->transaction_next;
1132         else if (j->transaction_next)
1133                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1134         else
1135                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1136
1137         if (j->transaction_next)
1138                 j->transaction_next->transaction_prev = j->transaction_prev;
1139
1140         j->transaction_prev = j->transaction_next = NULL;
1141
1142         while (j->subject_list)
1143                 job_dependency_free(j->subject_list);
1144
1145         while (j->object_list) {
1146                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1147
1148                 job_dependency_free(j->object_list);
1149
1150                 if (other && delete_dependencies) {
1151                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
1152                                   unit_id(other->unit), job_type_to_string(other->type),
1153                                   unit_id(j->unit), job_type_to_string(j->type));
1154                         transaction_delete_job(m, other, delete_dependencies);
1155                 }
1156         }
1157 }
1158
1159 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *unit, Job *by, bool matters, bool force, Job **_ret) {
1160         Job *ret;
1161         Iterator i;
1162         Unit *dep;
1163         int r;
1164         bool is_new;
1165
1166         assert(m);
1167         assert(type < _JOB_TYPE_MAX);
1168         assert(unit);
1169
1170         if (unit->meta.load_state != UNIT_LOADED)
1171                 return -EINVAL;
1172
1173         if (!unit_job_is_applicable(unit, type))
1174                 return -EBADR;
1175
1176         /* First add the job. */
1177         if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new)))
1178                 return -ENOMEM;
1179
1180         /* Then, add a link to the job. */
1181         if (!job_dependency_new(by, ret, matters))
1182                 return -ENOMEM;
1183
1184         if (is_new) {
1185                 /* Finally, recursively add in all dependencies. */
1186                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1187                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1188                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
1189                                         goto fail;
1190                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i)
1191                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
1192                                         goto fail;
1193                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1194                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0)
1195                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", unit_id(dep), strerror(-r));
1196                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1197                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
1198                                         goto fail;
1199                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i)
1200                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
1201                                         goto fail;
1202                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1203                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
1204                                         goto fail;
1205
1206                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1207
1208                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1209                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
1210                                         goto fail;
1211                 }
1212
1213                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1214         }
1215
1216         if (_ret)
1217                 *_ret = ret;
1218
1219         return 0;
1220
1221 fail:
1222         return r;
1223 }
1224
1225 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) {
1226         int r;
1227         Job *ret;
1228
1229         assert(m);
1230         assert(type < _JOB_TYPE_MAX);
1231         assert(unit);
1232         assert(mode < _JOB_MODE_MAX);
1233
1234         log_debug("Trying to enqueue job %s/%s", unit_id(unit), job_type_to_string(type));
1235
1236         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret)) < 0) {
1237                 transaction_abort(m);
1238                 return r;
1239         }
1240
1241         if ((r = transaction_activate(m, mode)) < 0)
1242                 return r;
1243
1244         log_debug("Enqueued job %s/%s as %u", unit_id(unit), job_type_to_string(type), (unsigned) ret->id);
1245
1246         if (_ret)
1247                 *_ret = ret;
1248
1249         return 0;
1250 }
1251
1252 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool force, Job **_ret) {
1253         Unit *unit;
1254         int r;
1255
1256         assert(m);
1257         assert(type < _JOB_TYPE_MAX);
1258         assert(name);
1259         assert(mode < _JOB_MODE_MAX);
1260
1261         if ((r = manager_load_unit(m, name, &unit)) < 0)
1262                 return r;
1263
1264         return manager_add_job(m, type, unit, mode, force, _ret);
1265 }
1266
1267 Job *manager_get_job(Manager *m, uint32_t id) {
1268         assert(m);
1269
1270         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1271 }
1272
1273 Unit *manager_get_unit(Manager *m, const char *name) {
1274         assert(m);
1275         assert(name);
1276
1277         return hashmap_get(m->units, name);
1278 }
1279
1280 unsigned manager_dispatch_load_queue(Manager *m) {
1281         Meta *meta;
1282         unsigned n = 0;
1283
1284         assert(m);
1285
1286         /* Make sure we are not run recursively */
1287         if (m->dispatching_load_queue)
1288                 return 0;
1289
1290         m->dispatching_load_queue = true;
1291
1292         /* Dispatches the load queue. Takes a unit from the queue and
1293          * tries to load its data until the queue is empty */
1294
1295         while ((meta = m->load_queue)) {
1296                 assert(meta->in_load_queue);
1297
1298                 unit_load(UNIT(meta));
1299                 n++;
1300         }
1301
1302         m->dispatching_load_queue = false;
1303         return n;
1304 }
1305
1306 int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
1307         Unit *ret;
1308         int r;
1309         const char *name;
1310
1311         assert(m);
1312         assert(path);
1313         assert(_ret);
1314
1315         /* This will load the service information files, but not actually
1316          * start any services or anything. */
1317
1318         name = file_name_from_path(path);
1319
1320         if ((ret = manager_get_unit(m, name))) {
1321                 *_ret = ret;
1322                 return 0;
1323         }
1324
1325         if (!(ret = unit_new(m)))
1326                 return -ENOMEM;
1327
1328         if (is_path(path)) {
1329                 if (!(ret->meta.fragment_path = strdup(path))) {
1330                         unit_free(ret);
1331                         return -ENOMEM;
1332                 }
1333         }
1334
1335         if ((r = unit_add_name(ret, name)) < 0) {
1336                 unit_free(ret);
1337                 return r;
1338         }
1339
1340         unit_add_to_load_queue(ret);
1341         unit_add_to_dbus_queue(ret);
1342
1343         manager_dispatch_load_queue(m);
1344
1345         *_ret = unit_follow_merge(ret);
1346         return 0;
1347 }
1348
1349 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1350         Iterator i;
1351         Job *j;
1352
1353         assert(s);
1354         assert(f);
1355
1356         HASHMAP_FOREACH(j, s->jobs, i)
1357                 job_dump(j, f, prefix);
1358 }
1359
1360 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1361         Iterator i;
1362         Unit *u;
1363         const char *t;
1364
1365         assert(s);
1366         assert(f);
1367
1368         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1369                 if (unit_id(u) == t)
1370                         unit_dump(u, f, prefix);
1371 }
1372
1373 void manager_clear_jobs(Manager *m) {
1374         Job *j;
1375
1376         assert(m);
1377
1378         transaction_abort(m);
1379
1380         while ((j = hashmap_first(m->jobs)))
1381                 job_free(j);
1382 }
1383
1384 unsigned manager_dispatch_run_queue(Manager *m) {
1385         Job *j;
1386         unsigned n = 0;
1387
1388         if (m->dispatching_run_queue)
1389                 return 0;
1390
1391         m->dispatching_run_queue = true;
1392
1393         while ((j = m->run_queue)) {
1394                 assert(j->installed);
1395                 assert(j->in_run_queue);
1396
1397                 job_run_and_invalidate(j);
1398                 n++;
1399         }
1400
1401         m->dispatching_run_queue = false;
1402         return n;
1403 }
1404
1405 unsigned manager_dispatch_dbus_queue(Manager *m) {
1406         Job *j;
1407         Meta *meta;
1408         unsigned n = 0;
1409
1410         assert(m);
1411
1412         if (m->dispatching_dbus_queue)
1413                 return 0;
1414
1415         m->dispatching_dbus_queue = true;
1416
1417         while ((meta = m->dbus_unit_queue)) {
1418                 assert(meta->in_dbus_queue);
1419
1420                 bus_unit_send_change_signal(UNIT(meta));
1421                 n++;
1422         }
1423
1424         while ((j = m->dbus_job_queue)) {
1425                 assert(j->in_dbus_queue);
1426
1427                 bus_job_send_change_signal(j);
1428                 n++;
1429         }
1430
1431         m->dispatching_dbus_queue = false;
1432         return n;
1433 }
1434
1435 static int manager_dispatch_sigchld(Manager *m) {
1436         assert(m);
1437
1438         for (;;) {
1439                 siginfo_t si;
1440                 Unit *u;
1441
1442                 zero(si);
1443                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) {
1444
1445                         if (errno == ECHILD)
1446                                 break;
1447
1448                         return -errno;
1449                 }
1450
1451                 if (si.si_pid == 0)
1452                         break;
1453
1454                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1455                         continue;
1456
1457                 log_debug("child %llu died (code=%s, status=%i)", (long long unsigned) si.si_pid, sigchld_code_to_string(si.si_code), si.si_status);
1458
1459                 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
1460                         continue;
1461
1462                 log_debug("child %llu belongs to %s", (long long unsigned) si.si_pid, unit_id(u));
1463
1464                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1465         }
1466
1467         return 0;
1468 }
1469
1470 static void manager_start_target(Manager *m, const char *name) {
1471         int r;
1472
1473         if ((r = manager_add_job_by_name(m, JOB_START, name, JOB_REPLACE, true, NULL)) < 0)
1474                 log_error("Failed to enqueue %s job: %s", name, strerror(-r));
1475 }
1476
1477 static int manager_process_signal_fd(Manager *m, bool *quit) {
1478         ssize_t n;
1479         struct signalfd_siginfo sfsi;
1480         bool sigchld = false;
1481
1482         assert(m);
1483
1484         for (;;) {
1485                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1486
1487                         if (n >= 0)
1488                                 return -EIO;
1489
1490                         if (errno == EAGAIN)
1491                                 break;
1492
1493                         return -errno;
1494                 }
1495
1496                 switch (sfsi.ssi_signo) {
1497
1498                 case SIGCHLD: {
1499                         char *name = NULL;
1500
1501                         get_process_name(sfsi.ssi_pid, &name);
1502                         log_debug("Got SIGCHLD for process %llu (%s)", (unsigned long long) sfsi.ssi_pid, strna(name));
1503                         free(name);
1504
1505                         sigchld = true;
1506                         break;
1507                 }
1508
1509                 case SIGINT:
1510                 case SIGTERM:
1511
1512                         if (m->running_as == MANAGER_INIT) {
1513                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET);
1514                                 break;
1515                         }
1516
1517                         *quit = true;
1518                         return 0;
1519
1520                 case SIGWINCH:
1521
1522                         if (m->running_as == MANAGER_INIT)
1523                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET);
1524
1525                         /* This is a nop on non-init */
1526                         break;
1527
1528                 case SIGPWR:
1529                         if (m->running_as == MANAGER_INIT)
1530                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET);
1531
1532                         /* This is a nop on non-init */
1533                         break;
1534
1535                 case SIGUSR1:
1536
1537                         printf("→ By units:\n");
1538                         manager_dump_units(m, stdout, "\t");
1539
1540                         printf("→ By jobs:\n");
1541                         manager_dump_jobs(m, stdout, "\t");
1542
1543                         break;
1544
1545                 default:
1546                         log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1547                 }
1548         }
1549
1550         if (sigchld)
1551                 return manager_dispatch_sigchld(m);
1552
1553         return 0;
1554 }
1555
1556 static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
1557         int r;
1558         Watch *w;
1559
1560         assert(m);
1561         assert(ev);
1562
1563         assert(w = ev->data.ptr);
1564
1565         switch (w->type) {
1566
1567         case WATCH_SIGNAL:
1568
1569                 /* An incoming signal? */
1570                 if (ev->events != EPOLLIN)
1571                         return -EINVAL;
1572
1573                 if ((r = manager_process_signal_fd(m, quit)) < 0)
1574                         return r;
1575
1576                 break;
1577
1578         case WATCH_FD:
1579
1580                 /* Some fd event, to be dispatched to the units */
1581                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
1582                 break;
1583
1584         case WATCH_TIMER: {
1585                 uint64_t v;
1586                 ssize_t k;
1587
1588                 /* Some timer event, to be dispatched to the units */
1589                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
1590
1591                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
1592                                 break;
1593
1594                         return k < 0 ? -errno : -EIO;
1595                 }
1596
1597                 UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
1598                 break;
1599         }
1600
1601         case WATCH_MOUNT:
1602                 /* Some mount table change, intended for the mount subsystem */
1603                 mount_fd_event(m, ev->events);
1604                 break;
1605
1606         case WATCH_UDEV:
1607                 /* Some notification from udev, intended for the device subsystem */
1608                 device_fd_event(m, ev->events);
1609                 break;
1610
1611         case WATCH_DBUS_WATCH:
1612                 bus_watch_event(m, w, ev->events);
1613                 break;
1614
1615         case WATCH_DBUS_TIMEOUT:
1616                 bus_timeout_event(m, w, ev->events);
1617                 break;
1618
1619         default:
1620                 assert_not_reached("Unknown epoll event type.");
1621         }
1622
1623         return 0;
1624 }
1625
1626 int manager_loop(Manager *m) {
1627         int r;
1628         bool quit = false;
1629
1630         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
1631
1632         assert(m);
1633
1634         do {
1635                 struct epoll_event event;
1636                 int n;
1637
1638                 if (!ratelimit_test(&rl)) {
1639                         /* Yay, something is going seriously wrong, pause a little */
1640                         log_warning("Looping too fast. Throttling execution a little.");
1641                         sleep(1);
1642                 }
1643
1644                 if (manager_dispatch_cleanup_queue(m) > 0)
1645                         continue;
1646
1647                 if (manager_dispatch_load_queue(m) > 0)
1648                         continue;
1649
1650                 if (manager_dispatch_run_queue(m) > 0)
1651                         continue;
1652
1653                 if (bus_dispatch(m) > 0)
1654                         continue;
1655
1656                 if (manager_dispatch_dbus_queue(m) > 0)
1657                         continue;
1658
1659                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
1660
1661                         if (errno == -EINTR)
1662                                 continue;
1663
1664                         return -errno;
1665                 }
1666
1667                 assert(n == 1);
1668
1669                 if ((r = process_event(m, &event, &quit)) < 0)
1670                         return r;
1671         } while (!quit);
1672
1673         return 0;
1674 }
1675
1676 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
1677         char *n;
1678         Unit *u;
1679
1680         assert(m);
1681         assert(s);
1682         assert(_u);
1683
1684         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
1685                 return -EINVAL;
1686
1687         if (!(n = bus_path_unescape(s+31)))
1688                 return -ENOMEM;
1689
1690         u = manager_get_unit(m, n);
1691         free(n);
1692
1693         if (!u)
1694                 return -ENOENT;
1695
1696         *_u = u;
1697
1698         return 0;
1699 }
1700
1701 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
1702         Job *j;
1703         unsigned id;
1704         int r;
1705
1706         assert(m);
1707         assert(s);
1708         assert(_j);
1709
1710         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
1711                 return -EINVAL;
1712
1713         if ((r = safe_atou(s + 30, &id)) < 0)
1714                 return r;
1715
1716         if (!(j = manager_get_job(m, id)))
1717                 return -ENOENT;
1718
1719         *_j = j;
1720
1721         return 0;
1722 }
1723
1724 static bool manager_utmp_good(Manager *m) {
1725         int r;
1726
1727         assert(m);
1728
1729         if ((r = mount_path_is_mounted(m, _PATH_UTMPX)) <= 0) {
1730
1731                 if (r < 0)
1732                         log_warning("Failed to determine whether " _PATH_UTMPX " is mounted: %s", strerror(-r));
1733
1734                 return false;
1735         }
1736
1737         return true;
1738 }
1739
1740 void manager_write_utmp_reboot(Manager *m) {
1741         int r;
1742
1743         assert(m);
1744
1745         if (m->utmp_reboot_written)
1746                 return;
1747
1748         if (m->running_as != MANAGER_INIT)
1749                 return;
1750
1751         if (!manager_utmp_good(m))
1752                 return;
1753
1754         if ((r = utmp_put_reboot(m->boot_timestamp)) < 0) {
1755
1756                 if (r != -ENOENT && r != -EROFS)
1757                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
1758
1759                 return;
1760         }
1761
1762         m->utmp_reboot_written = true;
1763 }
1764
1765 void manager_write_utmp_runlevel(Manager *m, Unit *u) {
1766         int runlevel, r;
1767
1768         assert(m);
1769         assert(u);
1770
1771         if (u->meta.type != UNIT_TARGET)
1772                 return;
1773
1774         if (m->running_as != MANAGER_INIT)
1775                 return;
1776
1777         if (!manager_utmp_good(m))
1778                 return;
1779
1780         if ((runlevel = target_get_runlevel(TARGET(u))) <= 0)
1781                 return;
1782
1783         if ((r = utmp_put_runlevel(0, runlevel, 0)) < 0) {
1784
1785                 if (r != -ENOENT && r != -EROFS)
1786                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
1787         }
1788 }
1789
1790 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
1791         [MANAGER_INIT] = "init",
1792         [MANAGER_SYSTEM] = "system",
1793         [MANAGER_SESSION] = "session"
1794 };
1795
1796 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);