src/manager.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   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 <sys/poll.h>
  31 #include <sys/reboot.h>
  32 #include <sys/ioctl.h>
  33 #include <linux/kd.h>
  34 #include <termios.h>
  35 #include <fcntl.h>
  36 #include <sys/types.h>
  37 #include <sys/stat.h>
  38 #include <dirent.h>
  39
  40 #ifdef HAVE_AUDIT
  41 #include <libaudit.h>
  42 #endif
  43
  44 #include "manager.h"
  45 #include "hashmap.h"
  46 #include "macro.h"
  47 #include "strv.h"
  48 #include "log.h"
  49 #include "util.h"
  50 #include "ratelimit.h"
  51 #include "cgroup.h"
  52 #include "mount-setup.h"
  53 #include "unit-name.h"
  54 #include "dbus-unit.h"
  55 #include "dbus-job.h"
  56 #include "missing.h"
  57 #include "path-lookup.h"
  58 #include "special.h"
  59 #include "bus-errors.h"
  60 #include "exit-status.h"
  61
  62 /* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
  63 #define GC_QUEUE_ENTRIES_MAX 16
  64
  65 /* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
  66 #define GC_QUEUE_USEC_MAX (10*USEC_PER_SEC)
  67
  68 /* Where clients shall send notification messages to */
  69 #define NOTIFY_SOCKET "/org/freedesktop/systemd1/notify"
  70
  71 static int manager_setup_notify(Manager *m) {
  72         union {
  73                 struct sockaddr sa;
  74                 struct sockaddr_un un;
  75         } sa;
  76         struct epoll_event ev;
  77         int one = 1;
  78
  79         assert(m);
  80
  81         m->notify_watch.type = WATCH_NOTIFY;
  82         if ((m->notify_watch.fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) {
  83                 log_error("Failed to allocate notification socket: %m");
  84                 return -errno;
  85         }
  86
  87         zero(sa);
  88         sa.sa.sa_family = AF_UNIX;
  89
  90         if (getpid() != 1)
  91                 snprintf(sa.un.sun_path+1, sizeof(sa.un.sun_path)-1, NOTIFY_SOCKET "/%llu", random_ull());
  92         else
  93                 strncpy(sa.un.sun_path+1, NOTIFY_SOCKET, sizeof(sa.un.sun_path)-1);
  94
  95         if (bind(m->notify_watch.fd, &sa.sa, sizeof(sa_family_t) + 1 + strlen(sa.un.sun_path+1)) < 0) {
  96                 log_error("bind() failed: %m");
  97                 return -errno;
  98         }
  99
 100         if (setsockopt(m->notify_watch.fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) {
 101                 log_error("SO_PASSCRED failed: %m");
 102                 return -errno;
 103         }
 104
 105         zero(ev);
 106         ev.events = EPOLLIN;
 107         ev.data.ptr = &m->notify_watch;
 108
 109         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->notify_watch.fd, &ev) < 0)
 110                 return -errno;
 111
 112         if (!(m->notify_socket = strdup(sa.un.sun_path+1)))
 113                 return -ENOMEM;
 114
 115         log_debug("Using notification socket %s", m->notify_socket);
 116
 117         return 0;
 118 }
 119
 120 static int enable_special_signals(Manager *m) {
 121         char fd;
 122
 123         assert(m);
 124
 125         /* Enable that we get SIGINT on control-alt-del */
 126         if (reboot(RB_DISABLE_CAD) < 0)
 127                 log_warning("Failed to enable ctrl-alt-del handling: %m");
 128
 129         if ((fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY)) < 0)
 130                 log_warning("Failed to open /dev/tty0: %m");
 131         else {
 132                 /* Enable that we get SIGWINCH on kbrequest */
 133                 if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
 134                         log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
 135
 136                 close_nointr_nofail(fd);
 137         }
 138
 139         return 0;
 140 }
 141
 142 static int manager_setup_signals(Manager *m) {
 143         sigset_t mask;
 144         struct epoll_event ev;
 145         struct sigaction sa;
 146
 147         assert(m);
 148
 149         /* We are not interested in SIGSTOP and friends. */
 150         zero(sa);
 151         sa.sa_handler = SIG_DFL;
 152         sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
 153         assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
 154
 155         assert_se(sigemptyset(&mask) == 0);
 156
 157         sigset_add_many(&mask,
 158                         SIGCHLD,     /* Child died */
 159                         SIGTERM,     /* Reexecute daemon */
 160                         SIGHUP,      /* Reload configuration */
 161                         SIGUSR1,     /* systemd/upstart: reconnect to D-Bus */
 162                         SIGUSR2,     /* systemd: dump status */
 163                         SIGINT,      /* Kernel sends us this on control-alt-del */
 164                         SIGWINCH,    /* Kernel sends us this on kbrequest (alt-arrowup) */
 165                         SIGPWR,      /* Some kernel drivers and upsd send us this on power failure */
 166                         SIGRTMIN+0,  /* systemd: start default.target */
 167                         SIGRTMIN+1,  /* systemd: start rescue.target */
 168                         SIGRTMIN+2,  /* systemd: isolate emergency.target */
 169                         SIGRTMIN+3,  /* systemd: start halt.target */
 170                         SIGRTMIN+4,  /* systemd: start poweroff.target */
 171                         SIGRTMIN+5,  /* systemd: start reboot.target */
 172                         -1);
 173         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 174
 175         m->signal_watch.type = WATCH_SIGNAL;
 176         if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
 177                 return -errno;
 178
 179         zero(ev);
 180         ev.events = EPOLLIN;
 181         ev.data.ptr = &m->signal_watch;
 182
 183         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
 184                 return -errno;
 185
 186         if (m->running_as == MANAGER_SYSTEM)
 187                 return enable_special_signals(m);
 188
 189         return 0;
 190 }
 191
 192 int manager_new(ManagerRunningAs running_as, Manager **_m) {
 193         Manager *m;
 194         int r = -ENOMEM;
 195
 196         assert(_m);
 197         assert(running_as >= 0);
 198         assert(running_as < _MANAGER_RUNNING_AS_MAX);
 199
 200         if (!(m = new0(Manager, 1)))
 201                 return -ENOMEM;
 202
 203         dual_timestamp_get(&m->startup_timestamp);
 204
 205         m->running_as = running_as;
 206         m->name_data_slot = m->subscribed_data_slot = -1;
 207         m->exit_code = _MANAGER_EXIT_CODE_INVALID;
 208         m->pin_cgroupfs_fd = -1;
 209
 210 #ifdef HAVE_AUDIT
 211         m->audit_fd = -1;
 212 #endif
 213
 214         m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
 215         m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
 216
 217         if (!(m->environment = strv_copy(environ)))
 218                 goto fail;
 219
 220         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
 221                 goto fail;
 222
 223         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 224                 goto fail;
 225
 226         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 227                 goto fail;
 228
 229         if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
 230                 goto fail;
 231
 232         if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
 233                 goto fail;
 234
 235         if (!(m->watch_bus = hashmap_new(string_hash_func, string_compare_func)))
 236                 goto fail;
 237
 238         if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
 239                 goto fail;
 240
 241         if ((r = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
 242                 goto fail;
 243
 244         if ((r = manager_setup_signals(m)) < 0)
 245                 goto fail;
 246
 247         if ((r = manager_setup_cgroup(m)) < 0)
 248                 goto fail;
 249
 250         if ((r = manager_setup_notify(m)) < 0)
 251                 goto fail;
 252
 253         /* Try to connect to the busses, if possible. */
 254         if ((r = bus_init(m)) < 0)
 255                 goto fail;
 256
 257 #ifdef HAVE_AUDIT
 258         if ((m->audit_fd = audit_open()) < 0)
 259                 log_error("Failed to connect to audit log: %m");
 260 #endif
 261
 262         *_m = m;
 263         return 0;
 264
 265 fail:
 266         manager_free(m);
 267         return r;
 268 }
 269
 270 static unsigned manager_dispatch_cleanup_queue(Manager *m) {
 271         Meta *meta;
 272         unsigned n = 0;
 273
 274         assert(m);
 275
 276         while ((meta = m->cleanup_queue)) {
 277                 assert(meta->in_cleanup_queue);
 278
 279                 unit_free((Unit*) meta);
 280                 n++;
 281         }
 282
 283         return n;
 284 }
 285
 286 enum {
 287         GC_OFFSET_IN_PATH,  /* This one is on the path we were travelling */
 288         GC_OFFSET_UNSURE,   /* No clue */
 289         GC_OFFSET_GOOD,     /* We still need this unit */
 290         GC_OFFSET_BAD,      /* We don't need this unit anymore */
 291         _GC_OFFSET_MAX
 292 };
 293
 294 static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
 295         Iterator i;
 296         Unit *other;
 297         bool is_bad;
 298
 299         assert(u);
 300
 301         if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
 302             u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
 303             u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
 304                 return;
 305
 306         if (u->meta.in_cleanup_queue)
 307                 goto bad;
 308
 309         if (unit_check_gc(u))
 310                 goto good;
 311
 312         u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
 313
 314         is_bad = true;
 315
 316         SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
 317                 unit_gc_sweep(other, gc_marker);
 318
 319                 if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
 320                         goto good;
 321
 322                 if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
 323                         is_bad = false;
 324         }
 325
 326         if (is_bad)
 327                 goto bad;
 328
 329         /* We were unable to find anything out about this entry, so
 330          * let's investigate it later */
 331         u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
 332         unit_add_to_gc_queue(u);
 333         return;
 334
 335 bad:
 336         /* We definitely know that this one is not useful anymore, so
 337          * let's mark it for deletion */
 338         u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
 339         unit_add_to_cleanup_queue(u);
 340         return;
 341
 342 good:
 343         u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
 344 }
 345
 346 static unsigned manager_dispatch_gc_queue(Manager *m) {
 347         Meta *meta;
 348         unsigned n = 0;
 349         unsigned gc_marker;
 350
 351         assert(m);
 352
 353         if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
 354             (m->gc_queue_timestamp <= 0 ||
 355              (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
 356                 return 0;
 357
 358         log_debug("Running GC...");
 359
 360         m->gc_marker += _GC_OFFSET_MAX;
 361         if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
 362                 m->gc_marker = 1;
 363
 364         gc_marker = m->gc_marker;
 365
 366         while ((meta = m->gc_queue)) {
 367                 assert(meta->in_gc_queue);
 368
 369                 unit_gc_sweep((Unit*) meta, gc_marker);
 370
 371                 LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
 372                 meta->in_gc_queue = false;
 373
 374                 n++;
 375
 376                 if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
 377                     meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
 378                         log_debug("Collecting %s", meta->id);
 379                         meta->gc_marker = gc_marker + GC_OFFSET_BAD;
 380                         unit_add_to_cleanup_queue((Unit*) meta);
 381                 }
 382         }
 383
 384         m->n_in_gc_queue = 0;
 385         m->gc_queue_timestamp = 0;
 386
 387         return n;
 388 }
 389
 390 static void manager_clear_jobs_and_units(Manager *m) {
 391         Job *j;
 392         Unit *u;
 393
 394         assert(m);
 395
 396         while ((j = hashmap_first(m->transaction_jobs)))
 397                 job_free(j);
 398
 399         while ((u = hashmap_first(m->units)))
 400                 unit_free(u);
 401
 402         manager_dispatch_cleanup_queue(m);
 403
 404         assert(!m->load_queue);
 405         assert(!m->run_queue);
 406         assert(!m->dbus_unit_queue);
 407         assert(!m->dbus_job_queue);
 408         assert(!m->cleanup_queue);
 409         assert(!m->gc_queue);
 410
 411         assert(hashmap_isempty(m->transaction_jobs));
 412         assert(hashmap_isempty(m->jobs));
 413         assert(hashmap_isempty(m->units));
 414 }
 415
 416 void manager_free(Manager *m) {
 417         UnitType c;
 418
 419         assert(m);
 420
 421         manager_clear_jobs_and_units(m);
 422
 423         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 424                 if (unit_vtable[c]->shutdown)
 425                         unit_vtable[c]->shutdown(m);
 426
 427         /* If we reexecute ourselves, we keep the root cgroup
 428          * around */
 429         manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
 430
 431         bus_done(m);
 432
 433         hashmap_free(m->units);
 434         hashmap_free(m->jobs);
 435         hashmap_free(m->transaction_jobs);
 436         hashmap_free(m->watch_pids);
 437         hashmap_free(m->watch_bus);
 438
 439         if (m->epoll_fd >= 0)
 440                 close_nointr_nofail(m->epoll_fd);
 441         if (m->signal_watch.fd >= 0)
 442                 close_nointr_nofail(m->signal_watch.fd);
 443         if (m->notify_watch.fd >= 0)
 444                 close_nointr_nofail(m->notify_watch.fd);
 445
 446 #ifdef HAVE_AUDIT
 447         if (m->audit_fd >= 0)
 448                 audit_close(m->audit_fd);
 449 #endif
 450
 451         free(m->notify_socket);
 452         free(m->console);
 453
 454         lookup_paths_free(&m->lookup_paths);
 455         strv_free(m->environment);
 456
 457         hashmap_free(m->cgroup_bondings);
 458         set_free_free(m->unit_path_cache);
 459
 460         free(m);
 461 }
 462
 463 int manager_enumerate(Manager *m) {
 464         int r = 0, q;
 465         UnitType c;
 466
 467         assert(m);
 468
 469         /* Let's ask every type to load all units from disk/kernel
 470          * that it might know */
 471         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 472                 if (unit_vtable[c]->enumerate)
 473                         if ((q = unit_vtable[c]->enumerate(m)) < 0)
 474                                 r = q;
 475
 476         manager_dispatch_load_queue(m);
 477         return r;
 478 }
 479
 480 int manager_coldplug(Manager *m) {
 481         int r = 0, q;
 482         Iterator i;
 483         Unit *u;
 484         char *k;
 485
 486         assert(m);
 487
 488         /* Then, let's set up their initial state. */
 489         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 490
 491                 /* ignore aliases */
 492                 if (u->meta.id != k)
 493                         continue;
 494
 495                 if ((q = unit_coldplug(u)) < 0)
 496                         r = q;
 497         }
 498
 499         return r;
 500 }
 501
 502 static void manager_build_unit_path_cache(Manager *m) {
 503         char **i;
 504         DIR *d = NULL;
 505         int r;
 506
 507         assert(m);
 508
 509         set_free_free(m->unit_path_cache);
 510
 511         if (!(m->unit_path_cache = set_new(string_hash_func, string_compare_func))) {
 512                 log_error("Failed to allocate unit path cache.");
 513                 return;
 514         }
 515
 516         /* This simply builds a list of files we know exist, so that
 517          * we don't always have to go to disk */
 518
 519         STRV_FOREACH(i, m->lookup_paths.unit_path) {
 520                 struct dirent *de;
 521
 522                 if (!(d = opendir(*i))) {
 523                         log_error("Failed to open directory: %m");
 524                         continue;
 525                 }
 526
 527                 while ((de = readdir(d))) {
 528                         char *p;
 529
 530                         if (ignore_file(de->d_name))
 531                                 continue;
 532
 533                         if (asprintf(&p, "%s/%s", streq(*i, "/") ? "" : *i, de->d_name) < 0) {
 534                                 r = -ENOMEM;
 535                                 goto fail;
 536                         }
 537
 538                         if ((r = set_put(m->unit_path_cache, p)) < 0) {
 539                                 free(p);
 540                                 goto fail;
 541                         }
 542                 }
 543
 544                 closedir(d);
 545                 d = NULL;
 546         }
 547
 548         return;
 549
 550 fail:
 551         log_error("Failed to build unit path cache: %s", strerror(-r));
 552
 553         set_free_free(m->unit_path_cache);
 554         m->unit_path_cache = NULL;
 555
 556         if (d)
 557                 closedir(d);
 558 }
 559
 560 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 561         int r, q;
 562
 563         assert(m);
 564
 565         manager_build_unit_path_cache(m);
 566
 567         /* If we will deserialize make sure that during enumeration
 568          * this is already known, so we increase the counter here
 569          * already */
 570         if (serialization)
 571                 m->n_deserializing ++;
 572
 573         /* First, enumerate what we can from all config files */
 574         r = manager_enumerate(m);
 575
 576         /* Second, deserialize if there is something to deserialize */
 577         if (serialization)
 578                 if ((q = manager_deserialize(m, serialization, fds)) < 0)
 579                         r = q;
 580
 581         /* Third, fire things up! */
 582         if ((q = manager_coldplug(m)) < 0)
 583                 r = q;
 584
 585         if (serialization) {
 586                 assert(m->n_deserializing > 0);
 587                 m->n_deserializing --;
 588         }
 589
 590         return r;
 591 }
 592
 593 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
 594         assert(m);
 595         assert(j);
 596
 597         /* Deletes one job from the transaction */
 598
 599         manager_transaction_unlink_job(m, j, delete_dependencies);
 600
 601         if (!j->installed)
 602                 job_free(j);
 603 }
 604
 605 static void transaction_delete_unit(Manager *m, Unit *u) {
 606         Job *j;
 607
 608         /* Deletes all jobs associated with a certain unit from the
 609          * transaction */
 610
 611         while ((j = hashmap_get(m->transaction_jobs, u)))
 612                 transaction_delete_job(m, j, true);
 613 }
 614
 615 static void transaction_clean_dependencies(Manager *m) {
 616         Iterator i;
 617         Job *j;
 618
 619         assert(m);
 620
 621         /* Drops all dependencies of all installed jobs */
 622
 623         HASHMAP_FOREACH(j, m->jobs, i) {
 624                 while (j->subject_list)
 625                         job_dependency_free(j->subject_list);
 626                 while (j->object_list)
 627                         job_dependency_free(j->object_list);
 628         }
 629
 630         assert(!m->transaction_anchor);
 631 }
 632
 633 static void transaction_abort(Manager *m) {
 634         Job *j;
 635
 636         assert(m);
 637
 638         while ((j = hashmap_first(m->transaction_jobs)))
 639                 if (j->installed)
 640                         transaction_delete_job(m, j, true);
 641                 else
 642                         job_free(j);
 643
 644         assert(hashmap_isempty(m->transaction_jobs));
 645
 646         transaction_clean_dependencies(m);
 647 }
 648
 649 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 650         JobDependency *l;
 651
 652         assert(m);
 653
 654         /* A recursive sweep through the graph that marks all units
 655          * that matter to the anchor job, i.e. are directly or
 656          * indirectly a dependency of the anchor job via paths that
 657          * are fully marked as mattering. */
 658
 659         if (j)
 660                 l = j->subject_list;
 661         else
 662                 l = m->transaction_anchor;
 663
 664         LIST_FOREACH(subject, l, l) {
 665
 666                 /* This link does not matter */
 667                 if (!l->matters)
 668                         continue;
 669
 670                 /* This unit has already been marked */
 671                 if (l->object->generation == generation)
 672                         continue;
 673
 674                 l->object->matters_to_anchor = true;
 675                 l->object->generation = generation;
 676
 677                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 678         }
 679 }
 680
 681 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 682         JobDependency *l, *last;
 683
 684         assert(j);
 685         assert(other);
 686         assert(j->unit == other->unit);
 687         assert(!j->installed);
 688
 689         /* Merges 'other' into 'j' and then deletes j. */
 690
 691         j->type = t;
 692         j->state = JOB_WAITING;
 693         j->override = j->override || other->override;
 694
 695         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 696
 697         /* Patch us in as new owner of the JobDependency objects */
 698         last = NULL;
 699         LIST_FOREACH(subject, l, other->subject_list) {
 700                 assert(l->subject == other);
 701                 l->subject = j;
 702                 last = l;
 703         }
 704
 705         /* Merge both lists */
 706         if (last) {
 707                 last->subject_next = j->subject_list;
 708                 if (j->subject_list)
 709                         j->subject_list->subject_prev = last;
 710                 j->subject_list = other->subject_list;
 711         }
 712
 713         /* Patch us in as new owner of the JobDependency objects */
 714         last = NULL;
 715         LIST_FOREACH(object, l, other->object_list) {
 716                 assert(l->object == other);
 717                 l->object = j;
 718                 last = l;
 719         }
 720
 721         /* Merge both lists */
 722         if (last) {
 723                 last->object_next = j->object_list;
 724                 if (j->object_list)
 725                         j->object_list->object_prev = last;
 726                 j->object_list = other->object_list;
 727         }
 728
 729         /* Kill the other job */
 730         other->subject_list = NULL;
 731         other->object_list = NULL;
 732         transaction_delete_job(m, other, true);
 733 }
 734 static bool job_is_conflicted_by(Job *j) {
 735         JobDependency *l;
 736
 737         assert(j);
 738
 739         /* Returns true if this job is pulled in by a least one
 740          * ConflictedBy dependency. */
 741
 742         LIST_FOREACH(object, l, j->object_list)
 743                 if (l->conflicts)
 744                         return true;
 745
 746         return false;
 747 }
 748
 749 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 750         Job *k;
 751
 752         assert(j);
 753
 754         /* Tries to delete one item in the linked list
 755          * j->transaction_next->transaction_next->... that conflicts
 756          * whith another one, in an attempt to make an inconsistent
 757          * transaction work. */
 758
 759         /* We rely here on the fact that if a merged with b does not
 760          * merge with c, either a or b merge with c neither */
 761         LIST_FOREACH(transaction, j, j)
 762                 LIST_FOREACH(transaction, k, j->transaction_next) {
 763                         Job *d;
 764
 765                         /* Is this one mergeable? Then skip it */
 766                         if (job_type_is_mergeable(j->type, k->type))
 767                                 continue;
 768
 769                         /* Ok, we found two that conflict, let's see if we can
 770                          * drop one of them */
 771                         if (!j->matters_to_anchor && !k->matters_to_anchor) {
 772
 773                                 /* Both jobs don't matter, so let's
 774                                  * find the one that is smarter to
 775                                  * remove. Let's think positive and
 776                                  * rather remove stops then starts --
 777                                  * except if something is being
 778                                  * stopped because it is conflicted by
 779                                  * another unit in which case we
 780                                  * rather remove the start. */
 781
 782                                 log_debug("Looking at job %s/%s conflicted_by=%s", j->unit->meta.id, job_type_to_string(j->type), yes_no(j->type == JOB_STOP && job_is_conflicted_by(j)));
 783                                 log_debug("Looking at job %s/%s conflicted_by=%s", k->unit->meta.id, job_type_to_string(k->type), yes_no(k->type == JOB_STOP && job_is_conflicted_by(k)));
 784
 785                                 if (j->type == JOB_STOP) {
 786
 787                                         if (job_is_conflicted_by(j))
 788                                                 d = k;
 789                                         else
 790                                                 d = j;
 791
 792                                 } else if (k->type == JOB_STOP) {
 793
 794                                         if (job_is_conflicted_by(k))
 795                                                 d = j;
 796                                         else
 797                                                 d = k;
 798                                 } else
 799                                         d = j;
 800
 801                         } else if (!j->matters_to_anchor)
 802                                 d = j;
 803                         else if (!k->matters_to_anchor)
 804                                 d = k;
 805                         else
 806                                 return -ENOEXEC;
 807
 808                         /* Ok, we can drop one, so let's do so. */
 809                         log_debug("Fixing conflicting jobs by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
 810                         transaction_delete_job(m, d, true);
 811                         return 0;
 812                 }
 813
 814         return -EINVAL;
 815 }
 816
 817 static int transaction_merge_jobs(Manager *m, DBusError *e) {
 818         Job *j;
 819         Iterator i;
 820         int r;
 821
 822         assert(m);
 823
 824         /* First step, check whether any of the jobs for one specific
 825          * task conflict. If so, try to drop one of them. */
 826         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 827                 JobType t;
 828                 Job *k;
 829
 830                 t = j->type;
 831                 LIST_FOREACH(transaction, k, j->transaction_next) {
 832                         if (job_type_merge(&t, k->type) >= 0)
 833                                 continue;
 834
 835                         /* OK, we could not merge all jobs for this
 836                          * action. Let's see if we can get rid of one
 837                          * of them */
 838
 839                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 840                                 /* Ok, we managed to drop one, now
 841                                  * let's ask our callers to call us
 842                                  * again after garbage collecting */
 843                                 return -EAGAIN;
 844
 845                         /* We couldn't merge anything. Failure */
 846                         dbus_set_error(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING, "Transaction contains conflicting jobs '%s' and '%s' for %s. Probably contradicting requirement dependencies configured.",
 847                                        job_type_to_string(t), job_type_to_string(k->type), k->unit->meta.id);
 848                         return r;
 849                 }
 850         }
 851
 852         /* Second step, merge the jobs. */
 853         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 854                 JobType t = j->type;
 855                 Job *k;
 856
 857                 /* Merge all transactions */
 858                 LIST_FOREACH(transaction, k, j->transaction_next)
 859                         assert_se(job_type_merge(&t, k->type) == 0);
 860
 861                 /* If an active job is mergeable, merge it too */
 862                 if (j->unit->meta.job)
 863                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 864
 865                 while ((k = j->transaction_next)) {
 866                         if (j->installed) {
 867                                 transaction_merge_and_delete_job(m, k, j, t);
 868                                 j = k;
 869                         } else
 870                                 transaction_merge_and_delete_job(m, j, k, t);
 871                 }
 872
 873                 assert(!j->transaction_next);
 874                 assert(!j->transaction_prev);
 875         }
 876
 877         return 0;
 878 }
 879
 880 static void transaction_drop_redundant(Manager *m) {
 881         bool again;
 882
 883         assert(m);
 884
 885         /* Goes through the transaction and removes all jobs that are
 886          * a noop */
 887
 888         do {
 889                 Job *j;
 890                 Iterator i;
 891
 892                 again = false;
 893
 894                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 895                         bool changes_something = false;
 896                         Job *k;
 897
 898                         LIST_FOREACH(transaction, k, j) {
 899
 900                                 if (!job_is_anchor(k) &&
 901                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
 902                                         continue;
 903
 904                                 changes_something = true;
 905                                 break;
 906                         }
 907
 908                         if (changes_something)
 909                                 continue;
 910
 911                         log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
 912                         transaction_delete_job(m, j, false);
 913                         again = true;
 914                         break;
 915                 }
 916
 917         } while (again);
 918 }
 919
 920 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 921         assert(u);
 922         assert(!j->transaction_prev);
 923
 924         /* Checks whether at least one of the jobs for this unit
 925          * matters to the anchor. */
 926
 927         LIST_FOREACH(transaction, j, j)
 928                 if (j->matters_to_anchor)
 929                         return true;
 930
 931         return false;
 932 }
 933
 934 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation, DBusError *e) {
 935         Iterator i;
 936         Unit *u;
 937         int r;
 938
 939         assert(m);
 940         assert(j);
 941         assert(!j->transaction_prev);
 942
 943         /* Does a recursive sweep through the ordering graph, looking
 944          * for a cycle. If we find cycle we try to break it. */
 945
 946         /* Have we seen this before? */
 947         if (j->generation == generation) {
 948                 Job *k, *delete;
 949
 950                 /* If the marker is NULL we have been here already and
 951                  * decided the job was loop-free from here. Hence
 952                  * shortcut things and return right-away. */
 953                 if (!j->marker)
 954                         return 0;
 955
 956                 /* So, the marker is not NULL and we already have been
 957                  * here. We have a cycle. Let's try to break it. We go
 958                  * backwards in our path and try to find a suitable
 959                  * job to remove. We use the marker to find our way
 960                  * back, since smart how we are we stored our way back
 961                  * in there. */
 962                 log_warning("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 963
 964                 delete = NULL;
 965                 for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) {
 966
 967                         log_info("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 968
 969                         if (!delete &&
 970                             !k->installed &&
 971                             !unit_matters_to_anchor(k->unit, k)) {
 972                                 /* Ok, we can drop this one, so let's
 973                                  * do so. */
 974                                 delete = k;
 975                         }
 976
 977                         /* Check if this in fact was the beginning of
 978                          * the cycle */
 979                         if (k == j)
 980                                 break;
 981                 }
 982
 983
 984                 if (delete) {
 985                         log_warning("Breaking ordering cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 986                         transaction_delete_unit(m, delete->unit);
 987                         return -EAGAIN;
 988                 }
 989
 990                 log_error("Unable to break cycle");
 991
 992                 dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See logs for details.");
 993                 return -ENOEXEC;
 994         }
 995
 996         /* Make the marker point to where we come from, so that we can
 997          * find our way backwards if we want to break a cycle. We use
 998          * a special marker for the beginning: we point to
 999          * ourselves. */
1000         j->marker = from ? from : j;
1001         j->generation = generation;
1002
1003         /* We assume that the the dependencies are bidirectional, and
1004          * hence can ignore UNIT_AFTER */
1005         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
1006                 Job *o;
1007
1008                 /* Is there a job for this unit? */
1009                 if (!(o = hashmap_get(m->transaction_jobs, u)))
1010
1011                         /* Ok, there is no job for this in the
1012                          * transaction, but maybe there is already one
1013                          * running? */
1014                         if (!(o = u->meta.job))
1015                                 continue;
1016
1017                 if ((r = transaction_verify_order_one(m, o, j, generation, e)) < 0)
1018                         return r;
1019         }
1020
1021         /* Ok, let's backtrack, and remember that this entry is not on
1022          * our path anymore. */
1023         j->marker = NULL;
1024
1025         return 0;
1026 }
1027
1028 static int transaction_verify_order(Manager *m, unsigned *generation, DBusError *e) {
1029         Job *j;
1030         int r;
1031         Iterator i;
1032         unsigned g;
1033
1034         assert(m);
1035         assert(generation);
1036
1037         /* Check if the ordering graph is cyclic. If it is, try to fix
1038          * that up by dropping one of the jobs. */
1039
1040         g = (*generation)++;
1041
1042         HASHMAP_FOREACH(j, m->transaction_jobs, i)
1043                 if ((r = transaction_verify_order_one(m, j, NULL, g, e)) < 0)
1044                         return r;
1045
1046         return 0;
1047 }
1048
1049 static void transaction_collect_garbage(Manager *m) {
1050         bool again;
1051
1052         assert(m);
1053
1054         /* Drop jobs that are not required by any other job */
1055
1056         do {
1057                 Iterator i;
1058                 Job *j;
1059
1060                 again = false;
1061
1062                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1063                         if (j->object_list)
1064                                 continue;
1065
1066                         log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
1067                         transaction_delete_job(m, j, true);
1068                         again = true;
1069                         break;
1070                 }
1071
1072         } while (again);
1073 }
1074
1075 static int transaction_is_destructive(Manager *m, DBusError *e) {
1076         Iterator i;
1077         Job *j;
1078
1079         assert(m);
1080
1081         /* Checks whether applying this transaction means that
1082          * existing jobs would be replaced */
1083
1084         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1085
1086                 /* Assume merged */
1087                 assert(!j->transaction_prev);
1088                 assert(!j->transaction_next);
1089
1090                 if (j->unit->meta.job &&
1091                     j->unit->meta.job != j &&
1092                     !job_type_is_superset(j->type, j->unit->meta.job->type)) {
1093
1094                         dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive.");
1095                         return -EEXIST;
1096                 }
1097         }
1098
1099         return 0;
1100 }
1101
1102 static void transaction_minimize_impact(Manager *m) {
1103         bool again;
1104         assert(m);
1105
1106         /* Drops all unnecessary jobs that reverse already active jobs
1107          * or that stop a running service. */
1108
1109         do {
1110                 Job *j;
1111                 Iterator i;
1112
1113                 again = false;
1114
1115                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1116                         LIST_FOREACH(transaction, j, j) {
1117                                 bool stops_running_service, changes_existing_job;
1118
1119                                 /* If it matters, we shouldn't drop it */
1120                                 if (j->matters_to_anchor)
1121                                         continue;
1122
1123                                 /* Would this stop a running service?
1124                                  * Would this change an existing job?
1125                                  * If so, let's drop this entry */
1126
1127                                 stops_running_service =
1128                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
1129
1130                                 changes_existing_job =
1131                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->type);
1132
1133                                 if (!stops_running_service && !changes_existing_job)
1134                                         continue;
1135
1136                                 if (stops_running_service)
1137                                         log_info("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
1138
1139                                 if (changes_existing_job)
1140                                         log_info("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
1141
1142                                 /* Ok, let's get rid of this */
1143                                 log_info("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
1144
1145                                 transaction_delete_job(m, j, true);
1146                                 again = true;
1147                                 break;
1148                         }
1149
1150                         if (again)
1151                                 break;
1152                 }
1153
1154         } while (again);
1155 }
1156
1157 static int transaction_apply(Manager *m) {
1158         Iterator i;
1159         Job *j;
1160         int r;
1161
1162         /* Moves the transaction jobs to the set of active jobs */
1163
1164         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1165                 /* Assume merged */
1166                 assert(!j->transaction_prev);
1167                 assert(!j->transaction_next);
1168
1169                 if (j->installed)
1170                         continue;
1171
1172                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1173                         goto rollback;
1174         }
1175
1176         while ((j = hashmap_steal_first(m->transaction_jobs))) {
1177                 if (j->installed)
1178                         continue;
1179
1180                 if (j->unit->meta.job)
1181                         job_free(j->unit->meta.job);
1182
1183                 j->unit->meta.job = j;
1184                 j->installed = true;
1185
1186                 /* We're fully installed. Now let's free data we don't
1187                  * need anymore. */
1188
1189                 assert(!j->transaction_next);
1190                 assert(!j->transaction_prev);
1191
1192                 job_add_to_run_queue(j);
1193                 job_add_to_dbus_queue(j);
1194                 job_start_timer(j);
1195         }
1196
1197         /* As last step, kill all remaining job dependencies. */
1198         transaction_clean_dependencies(m);
1199
1200         return 0;
1201
1202 rollback:
1203
1204         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1205                 if (j->installed)
1206                         continue;
1207
1208                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1209         }
1210
1211         return r;
1212 }
1213
1214 static int transaction_activate(Manager *m, JobMode mode, DBusError *e) {
1215         int r;
1216         unsigned generation = 1;
1217
1218         assert(m);
1219
1220         /* This applies the changes recorded in transaction_jobs to
1221          * the actual list of jobs, if possible. */
1222
1223         /* First step: figure out which jobs matter */
1224         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1225
1226         /* Second step: Try not to stop any running services if
1227          * we don't have to. Don't try to reverse running
1228          * jobs if we don't have to. */
1229         transaction_minimize_impact(m);
1230
1231         /* Third step: Drop redundant jobs */
1232         transaction_drop_redundant(m);
1233
1234         for (;;) {
1235                 /* Fourth step: Let's remove unneeded jobs that might
1236                  * be lurking. */
1237                 transaction_collect_garbage(m);
1238
1239                 /* Fifth step: verify order makes sense and correct
1240                  * cycles if necessary and possible */
1241                 if ((r = transaction_verify_order(m, &generation, e)) >= 0)
1242                         break;
1243
1244                 if (r != -EAGAIN) {
1245                         log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r));
1246                         goto rollback;
1247                 }
1248
1249                 /* Let's see if the resulting transaction ordering
1250                  * graph is still cyclic... */
1251         }
1252
1253         for (;;) {
1254                 /* Sixth step: let's drop unmergeable entries if
1255                  * necessary and possible, merge entries we can
1256                  * merge */
1257                 if ((r = transaction_merge_jobs(m, e)) >= 0)
1258                         break;
1259
1260                 if (r != -EAGAIN) {
1261                         log_warning("Requested transaction contains unmergable jobs: %s", bus_error(e, r));
1262                         goto rollback;
1263                 }
1264
1265                 /* Seventh step: an entry got dropped, let's garbage
1266                  * collect its dependencies. */
1267                 transaction_collect_garbage(m);
1268
1269                 /* Let's see if the resulting transaction still has
1270                  * unmergeable entries ... */
1271         }
1272
1273         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1274         transaction_drop_redundant(m);
1275
1276         /* Ninth step: check whether we can actually apply this */
1277         if (mode == JOB_FAIL)
1278                 if ((r = transaction_is_destructive(m, e)) < 0) {
1279                         log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r));
1280                         goto rollback;
1281                 }
1282
1283         /* Tenth step: apply changes */
1284         if ((r = transaction_apply(m)) < 0) {
1285                 log_warning("Failed to apply transaction: %s", strerror(-r));
1286                 goto rollback;
1287         }
1288
1289         assert(hashmap_isempty(m->transaction_jobs));
1290         assert(!m->transaction_anchor);
1291
1292         return 0;
1293
1294 rollback:
1295         transaction_abort(m);
1296         return r;
1297 }
1298
1299 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1300         Job *j, *f;
1301
1302         assert(m);
1303         assert(unit);
1304
1305         /* Looks for an axisting prospective job and returns that. If
1306          * it doesn't exist it is created and added to the prospective
1307          * jobs list. */
1308
1309         f = hashmap_get(m->transaction_jobs, unit);
1310
1311         LIST_FOREACH(transaction, j, f) {
1312                 assert(j->unit == unit);
1313
1314                 if (j->type == type) {
1315                         if (is_new)
1316                                 *is_new = false;
1317                         return j;
1318                 }
1319         }
1320
1321         if (unit->meta.job && unit->meta.job->type == type)
1322                 j = unit->meta.job;
1323         else if (!(j = job_new(m, type, unit)))
1324                 return NULL;
1325
1326         j->generation = 0;
1327         j->marker = NULL;
1328         j->matters_to_anchor = false;
1329         j->override = override;
1330
1331         LIST_PREPEND(Job, transaction, f, j);
1332
1333         if (hashmap_replace(m->transaction_jobs, unit, f) < 0) {
1334                 job_free(j);
1335                 return NULL;
1336         }
1337
1338         if (is_new)
1339                 *is_new = true;
1340
1341         log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1342
1343         return j;
1344 }
1345
1346 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1347         assert(m);
1348         assert(j);
1349
1350         if (j->transaction_prev)
1351                 j->transaction_prev->transaction_next = j->transaction_next;
1352         else if (j->transaction_next)
1353                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1354         else
1355                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1356
1357         if (j->transaction_next)
1358                 j->transaction_next->transaction_prev = j->transaction_prev;
1359
1360         j->transaction_prev = j->transaction_next = NULL;
1361
1362         while (j->subject_list)
1363                 job_dependency_free(j->subject_list);
1364
1365         while (j->object_list) {
1366                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1367
1368                 job_dependency_free(j->object_list);
1369
1370                 if (other && delete_dependencies) {
1371                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
1372                                   other->unit->meta.id, job_type_to_string(other->type),
1373                                   j->unit->meta.id, job_type_to_string(j->type));
1374                         transaction_delete_job(m, other, delete_dependencies);
1375                 }
1376         }
1377 }
1378
1379 static int transaction_add_job_and_dependencies(
1380                 Manager *m,
1381                 JobType type,
1382                 Unit *unit,
1383                 Job *by,
1384                 bool matters,
1385                 bool override,
1386                 bool conflicts,
1387                 DBusError *e,
1388                 Job **_ret) {
1389         Job *ret;
1390         Iterator i;
1391         Unit *dep;
1392         int r;
1393         bool is_new;
1394
1395         assert(m);
1396         assert(type < _JOB_TYPE_MAX);
1397         assert(unit);
1398
1399         if (unit->meta.load_state != UNIT_LOADED && unit->meta.load_state != UNIT_FAILED) {
1400                 dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->meta.id);
1401                 return -EINVAL;
1402         }
1403
1404         if (type != JOB_STOP && unit->meta.load_state == UNIT_FAILED) {
1405                 dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s failed to load: %s. You might find more information in the logs.",
1406                                unit->meta.id,
1407                                strerror(-unit->meta.load_error));
1408                 return -EINVAL;
1409         }
1410
1411         if (!unit_job_is_applicable(unit, type)) {
1412                 dbus_set_error(e, BUS_ERROR_JOB_TYPE_NOT_APPLICABLE, "Job type %s is not applicable for unit %s.", job_type_to_string(type), unit->meta.id);
1413                 return -EBADR;
1414         }
1415
1416         /* First add the job. */
1417         if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
1418                 return -ENOMEM;
1419
1420         /* Then, add a link to the job. */
1421         if (!job_dependency_new(by, ret, matters, conflicts))
1422                 return -ENOMEM;
1423
1424         if (is_new) {
1425                 /* Finally, recursively add in all dependencies. */
1426                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1427                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1428                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1429                                         goto fail;
1430
1431                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
1432                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, false, e, NULL)) < 0 && r != -EBADR) {
1433                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1434                                         dbus_error_free(e);
1435                                 }
1436
1437                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1438                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, false, e, NULL)) < 0) {
1439                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1440                                         dbus_error_free(e);
1441                                 }
1442
1443                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1444                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1445                                         goto fail;
1446
1447                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1448                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, e, NULL)) < 0 && r != -EBADR) {
1449                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1450                                         dbus_error_free(e);
1451                                 }
1452
1453                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1454                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, true, e, NULL)) < 0 && r != -EBADR)
1455                                         goto fail;
1456
1457                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTED_BY], i)
1458                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1459                                         goto fail;
1460
1461                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1462
1463                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1464                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1465                                         goto fail;
1466                 }
1467
1468                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1469         }
1470
1471         if (_ret)
1472                 *_ret = ret;
1473
1474         return 0;
1475
1476 fail:
1477         return r;
1478 }
1479
1480 static int transaction_add_isolate_jobs(Manager *m) {
1481         Iterator i;
1482         Unit *u;
1483         char *k;
1484         int r;
1485
1486         assert(m);
1487
1488         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
1489
1490                 /* ignore aliases */
1491                 if (u->meta.id != k)
1492                         continue;
1493
1494                 if (UNIT_VTABLE(u)->no_isolate)
1495                         continue;
1496
1497                 /* No need to stop inactive jobs */
1498                 if (UNIT_IS_INACTIVE_OR_MAINTENANCE(unit_active_state(u)))
1499                         continue;
1500
1501                 /* Is there already something listed for this? */
1502                 if (hashmap_get(m->transaction_jobs, u))
1503                         continue;
1504
1505                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, false, NULL, NULL)) < 0)
1506                         log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
1507         }
1508
1509         return 0;
1510 }
1511
1512 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, DBusError *e, Job **_ret) {
1513         int r;
1514         Job *ret;
1515
1516         assert(m);
1517         assert(type < _JOB_TYPE_MAX);
1518         assert(unit);
1519         assert(mode < _JOB_MODE_MAX);
1520
1521         if (mode == JOB_ISOLATE && type != JOB_START) {
1522                 dbus_set_error(e, BUS_ERROR_INVALID_JOB_MODE, "Isolate is only valid for start.");
1523                 return -EINVAL;
1524         }
1525
1526         if (mode == JOB_ISOLATE && !unit->meta.allow_isolate) {
1527                 dbus_set_error(e, BUS_ERROR_NO_ISOLATION, "Operation refused, unit may not be isolated.");
1528                 return -EPERM;
1529         }
1530
1531         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1532
1533         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, false, e, &ret)) < 0) {
1534                 transaction_abort(m);
1535                 return r;
1536         }
1537
1538         if (mode == JOB_ISOLATE)
1539                 if ((r = transaction_add_isolate_jobs(m)) < 0) {
1540                         transaction_abort(m);
1541                         return r;
1542                 }
1543
1544         if ((r = transaction_activate(m, mode, e)) < 0)
1545                 return r;
1546
1547         log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1548
1549         if (_ret)
1550                 *_ret = ret;
1551
1552         return 0;
1553 }
1554
1555 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, DBusError *e, Job **_ret) {
1556         Unit *unit;
1557         int r;
1558
1559         assert(m);
1560         assert(type < _JOB_TYPE_MAX);
1561         assert(name);
1562         assert(mode < _JOB_MODE_MAX);
1563
1564         if ((r = manager_load_unit(m, name, NULL, NULL, &unit)) < 0)
1565                 return r;
1566
1567         return manager_add_job(m, type, unit, mode, override, e, _ret);
1568 }
1569
1570 Job *manager_get_job(Manager *m, uint32_t id) {
1571         assert(m);
1572
1573         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1574 }
1575
1576 Unit *manager_get_unit(Manager *m, const char *name) {
1577         assert(m);
1578         assert(name);
1579
1580         return hashmap_get(m->units, name);
1581 }
1582
1583 unsigned manager_dispatch_load_queue(Manager *m) {
1584         Meta *meta;
1585         unsigned n = 0;
1586
1587         assert(m);
1588
1589         /* Make sure we are not run recursively */
1590         if (m->dispatching_load_queue)
1591                 return 0;
1592
1593         m->dispatching_load_queue = true;
1594
1595         /* Dispatches the load queue. Takes a unit from the queue and
1596          * tries to load its data until the queue is empty */
1597
1598         while ((meta = m->load_queue)) {
1599                 assert(meta->in_load_queue);
1600
1601                 unit_load((Unit*) meta);
1602                 n++;
1603         }
1604
1605         m->dispatching_load_queue = false;
1606         return n;
1607 }
1608
1609 int manager_load_unit_prepare(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1610         Unit *ret;
1611         int r;
1612
1613         assert(m);
1614         assert(name || path);
1615
1616         /* This will prepare the unit for loading, but not actually
1617          * load anything from disk. */
1618
1619         if (path && !is_path(path)) {
1620                 dbus_set_error(e, BUS_ERROR_INVALID_PATH, "Path %s is not absolute.", path);
1621                 return -EINVAL;
1622         }
1623
1624         if (!name)
1625                 name = file_name_from_path(path);
1626
1627         if (!unit_name_is_valid(name)) {
1628                 dbus_set_error(e, BUS_ERROR_INVALID_NAME, "Unit name %s is not valid.", name);
1629                 return -EINVAL;
1630         }
1631
1632         if ((ret = manager_get_unit(m, name))) {
1633                 *_ret = ret;
1634                 return 1;
1635         }
1636
1637         if (!(ret = unit_new(m)))
1638                 return -ENOMEM;
1639
1640         if (path)
1641                 if (!(ret->meta.fragment_path = strdup(path))) {
1642                         unit_free(ret);
1643                         return -ENOMEM;
1644                 }
1645
1646         if ((r = unit_add_name(ret, name)) < 0) {
1647                 unit_free(ret);
1648                 return r;
1649         }
1650
1651         unit_add_to_load_queue(ret);
1652         unit_add_to_dbus_queue(ret);
1653         unit_add_to_gc_queue(ret);
1654
1655         if (_ret)
1656                 *_ret = ret;
1657
1658         return 0;
1659 }
1660
1661 int manager_load_unit(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1662         int r;
1663
1664         assert(m);
1665
1666         /* This will load the service information files, but not actually
1667          * start any services or anything. */
1668
1669         if ((r = manager_load_unit_prepare(m, name, path, e, _ret)) != 0)
1670                 return r;
1671
1672         manager_dispatch_load_queue(m);
1673
1674         if (_ret)
1675                 *_ret = unit_follow_merge(*_ret);
1676
1677         return 0;
1678 }
1679
1680 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1681         Iterator i;
1682         Job *j;
1683
1684         assert(s);
1685         assert(f);
1686
1687         HASHMAP_FOREACH(j, s->jobs, i)
1688                 job_dump(j, f, prefix);
1689 }
1690
1691 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1692         Iterator i;
1693         Unit *u;
1694         const char *t;
1695
1696         assert(s);
1697         assert(f);
1698
1699         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1700                 if (u->meta.id == t)
1701                         unit_dump(u, f, prefix);
1702 }
1703
1704 void manager_clear_jobs(Manager *m) {
1705         Job *j;
1706
1707         assert(m);
1708
1709         transaction_abort(m);
1710
1711         while ((j = hashmap_first(m->jobs)))
1712                 job_free(j);
1713 }
1714
1715 unsigned manager_dispatch_run_queue(Manager *m) {
1716         Job *j;
1717         unsigned n = 0;
1718
1719         if (m->dispatching_run_queue)
1720                 return 0;
1721
1722         m->dispatching_run_queue = true;
1723
1724         while ((j = m->run_queue)) {
1725                 assert(j->installed);
1726                 assert(j->in_run_queue);
1727
1728                 job_run_and_invalidate(j);
1729                 n++;
1730         }
1731
1732         m->dispatching_run_queue = false;
1733         return n;
1734 }
1735
1736 unsigned manager_dispatch_dbus_queue(Manager *m) {
1737         Job *j;
1738         Meta *meta;
1739         unsigned n = 0;
1740
1741         assert(m);
1742
1743         if (m->dispatching_dbus_queue)
1744                 return 0;
1745
1746         m->dispatching_dbus_queue = true;
1747
1748         while ((meta = m->dbus_unit_queue)) {
1749                 assert(meta->in_dbus_queue);
1750
1751                 bus_unit_send_change_signal((Unit*) meta);
1752                 n++;
1753         }
1754
1755         while ((j = m->dbus_job_queue)) {
1756                 assert(j->in_dbus_queue);
1757
1758                 bus_job_send_change_signal(j);
1759                 n++;
1760         }
1761
1762         m->dispatching_dbus_queue = false;
1763         return n;
1764 }
1765
1766 static int manager_process_notify_fd(Manager *m) {
1767         ssize_t n;
1768
1769         assert(m);
1770
1771         for (;;) {
1772                 char buf[4096];
1773                 struct msghdr msghdr;
1774                 struct iovec iovec;
1775                 struct ucred *ucred;
1776                 union {
1777                         struct cmsghdr cmsghdr;
1778                         uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
1779                 } control;
1780                 Unit *u;
1781                 char **tags;
1782
1783                 zero(iovec);
1784                 iovec.iov_base = buf;
1785                 iovec.iov_len = sizeof(buf)-1;
1786
1787                 zero(control);
1788                 zero(msghdr);
1789                 msghdr.msg_iov = &iovec;
1790                 msghdr.msg_iovlen = 1;
1791                 msghdr.msg_control = &control;
1792                 msghdr.msg_controllen = sizeof(control);
1793
1794                 if ((n = recvmsg(m->notify_watch.fd, &msghdr, MSG_DONTWAIT)) <= 0) {
1795                         if (n >= 0)
1796                                 return -EIO;
1797
1798                         if (errno == EAGAIN || errno == EINTR)
1799                                 break;
1800
1801                         return -errno;
1802                 }
1803
1804                 if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
1805                     control.cmsghdr.cmsg_level != SOL_SOCKET ||
1806                     control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
1807                     control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
1808                         log_warning("Received notify message without credentials. Ignoring.");
1809                         continue;
1810                 }
1811
1812                 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
1813
1814                 if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(ucred->pid))))
1815                         if (!(u = cgroup_unit_by_pid(m, ucred->pid))) {
1816                                 log_warning("Cannot find unit for notify message of PID %lu.", (unsigned long) ucred->pid);
1817                                 continue;
1818                         }
1819
1820                 assert((size_t) n < sizeof(buf));
1821                 buf[n] = 0;
1822                 if (!(tags = strv_split(buf, "\n\r")))
1823                         return -ENOMEM;
1824
1825                 log_debug("Got notification message for unit %s", u->meta.id);
1826
1827                 if (UNIT_VTABLE(u)->notify_message)
1828                         UNIT_VTABLE(u)->notify_message(u, ucred->pid, tags);
1829
1830                 strv_free(tags);
1831         }
1832
1833         return 0;
1834 }
1835
1836 static int manager_dispatch_sigchld(Manager *m) {
1837         assert(m);
1838
1839         for (;;) {
1840                 siginfo_t si;
1841                 Unit *u;
1842                 int r;
1843
1844                 zero(si);
1845
1846                 /* First we call waitd() for a PID and do not reap the
1847                  * zombie. That way we can still access /proc/$PID for
1848                  * it while it is a zombie. */
1849                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1850
1851                         if (errno == ECHILD)
1852                                 break;
1853
1854                         if (errno == EINTR)
1855                                 continue;
1856
1857                         return -errno;
1858                 }
1859
1860                 if (si.si_pid <= 0)
1861                         break;
1862
1863                 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1864                         char *name = NULL;
1865
1866                         get_process_name(si.si_pid, &name);
1867                         log_debug("Got SIGCHLD for process %lu (%s)", (unsigned long) si.si_pid, strna(name));
1868                         free(name);
1869                 }
1870
1871                 /* Let's flush any message the dying child might still
1872                  * have queued for us. This ensures that the process
1873                  * still exists in /proc so that we can figure out
1874                  * which cgroup and hence unit it belongs to. */
1875                 if ((r = manager_process_notify_fd(m)) < 0)
1876                         return r;
1877
1878                 /* And now figure out the unit this belongs to */
1879                 if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(si.si_pid))))
1880                         u = cgroup_unit_by_pid(m, si.si_pid);
1881
1882                 /* And now, we actually reap the zombie. */
1883                 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1884                         if (errno == EINTR)
1885                                 continue;
1886
1887                         return -errno;
1888                 }
1889
1890                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1891                         continue;
1892
1893                 log_debug("Child %lu died (code=%s, status=%i/%s)",
1894                           (long unsigned) si.si_pid,
1895                           sigchld_code_to_string(si.si_code),
1896                           si.si_status,
1897                           strna(si.si_code == CLD_EXITED
1898                                 ? exit_status_to_string(si.si_status, EXIT_STATUS_FULL)
1899                                 : signal_to_string(si.si_status)));
1900
1901                 if (!u)
1902                         continue;
1903
1904                 log_debug("Child %lu belongs to %s", (long unsigned) si.si_pid, u->meta.id);
1905
1906                 hashmap_remove(m->watch_pids, LONG_TO_PTR(si.si_pid));
1907                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1908         }
1909
1910         return 0;
1911 }
1912
1913 static int manager_start_target(Manager *m, const char *name, JobMode mode) {
1914         int r;
1915         DBusError error;
1916
1917         dbus_error_init(&error);
1918
1919         log_info("Activating special unit %s", name);
1920
1921         if ((r = manager_add_job_by_name(m, JOB_START, name, mode, true, &error, NULL)) < 0)
1922                 log_error("Failed to enqueue %s job: %s", name, bus_error(&error, r));
1923
1924         dbus_error_free(&error);
1925
1926         return r;
1927 }
1928
1929 static int manager_process_signal_fd(Manager *m) {
1930         ssize_t n;
1931         struct signalfd_siginfo sfsi;
1932         bool sigchld = false;
1933
1934         assert(m);
1935
1936         for (;;) {
1937                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1938
1939                         if (n >= 0)
1940                                 return -EIO;
1941
1942                         if (errno == EINTR || errno == EAGAIN)
1943                                 break;
1944
1945                         return -errno;
1946                 }
1947
1948                 log_debug("Received SIG%s", strna(signal_to_string(sfsi.ssi_signo)));
1949
1950                 switch (sfsi.ssi_signo) {
1951
1952                 case SIGCHLD:
1953                         sigchld = true;
1954                         break;
1955
1956                 case SIGTERM:
1957                         if (m->running_as == MANAGER_SYSTEM) {
1958                                 /* This is for compatibility with the
1959                                  * original sysvinit */
1960                                 m->exit_code = MANAGER_REEXECUTE;
1961                                 break;
1962                         }
1963
1964                         /* Fall through */
1965
1966                 case SIGINT:
1967                         if (m->running_as == MANAGER_SYSTEM) {
1968                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET, JOB_REPLACE);
1969                                 break;
1970                         }
1971
1972                         /* Run the exit target if there is one, if not, just exit. */
1973                         if (manager_start_target(m, SPECIAL_EXIT_SERVICE, JOB_REPLACE) < 0) {
1974                                 m->exit_code = MANAGER_EXIT;
1975                                 return 0;
1976                         }
1977
1978                         break;
1979
1980                 case SIGWINCH:
1981                         if (m->running_as == MANAGER_SYSTEM)
1982                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET, JOB_REPLACE);
1983
1984                         /* This is a nop on non-init */
1985                         break;
1986
1987                 case SIGPWR:
1988                         if (m->running_as == MANAGER_SYSTEM)
1989                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET, JOB_REPLACE);
1990
1991                         /* This is a nop on non-init */
1992                         break;
1993
1994                 case SIGUSR1: {
1995                         Unit *u;
1996
1997                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1998
1999                         if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
2000                                 log_info("Trying to reconnect to bus...");
2001                                 bus_init(m);
2002                         }
2003
2004                         if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
2005                                 log_info("Loading D-Bus service...");
2006                                 manager_start_target(m, SPECIAL_DBUS_SERVICE, JOB_REPLACE);
2007                         }
2008
2009                         break;
2010                 }
2011
2012                 case SIGUSR2: {
2013                         FILE *f;
2014                         char *dump = NULL;
2015                         size_t size;
2016
2017                         if (!(f = open_memstream(&dump, &size))) {
2018                                 log_warning("Failed to allocate memory stream.");
2019                                 break;
2020                         }
2021
2022                         manager_dump_units(m, f, "\t");
2023                         manager_dump_jobs(m, f, "\t");
2024
2025                         if (ferror(f)) {
2026                                 fclose(f);
2027                                 free(dump);
2028                                 log_warning("Failed to write status stream");
2029                                 break;
2030                         }
2031
2032                         fclose(f);
2033                         log_dump(LOG_INFO, dump);
2034                         free(dump);
2035
2036                         break;
2037                 }
2038
2039                 case SIGHUP:
2040                         m->exit_code = MANAGER_RELOAD;
2041                         break;
2042
2043                 default: {
2044                         static const char * const table[] = {
2045                                 [0] = SPECIAL_DEFAULT_TARGET,
2046                                 [1] = SPECIAL_RESCUE_TARGET,
2047                                 [2] = SPECIAL_EMERGENCY_TARGET,
2048                                 [3] = SPECIAL_HALT_TARGET,
2049                                 [4] = SPECIAL_POWEROFF_TARGET,
2050                                 [5] = SPECIAL_REBOOT_TARGET
2051                         };
2052
2053                         if ((int) sfsi.ssi_signo >= SIGRTMIN+0 &&
2054                             (int) sfsi.ssi_signo < SIGRTMIN+(int) ELEMENTSOF(table)) {
2055                                 manager_start_target(m, table[sfsi.ssi_signo - SIGRTMIN],
2056                                                      (sfsi.ssi_signo == 1 || sfsi.ssi_signo == 2) ? JOB_ISOLATE : JOB_REPLACE);
2057                                 break;
2058                         }
2059
2060                         log_warning("Got unhandled signal <%s>.", strna(signal_to_string(sfsi.ssi_signo)));
2061                 }
2062                 }
2063         }
2064
2065         if (sigchld)
2066                 return manager_dispatch_sigchld(m);
2067
2068         return 0;
2069 }
2070
2071 static int process_event(Manager *m, struct epoll_event *ev) {
2072         int r;
2073         Watch *w;
2074
2075         assert(m);
2076         assert(ev);
2077
2078         assert(w = ev->data.ptr);
2079
2080         switch (w->type) {
2081
2082         case WATCH_SIGNAL:
2083
2084                 /* An incoming signal? */
2085                 if (ev->events != EPOLLIN)
2086                         return -EINVAL;
2087
2088                 if ((r = manager_process_signal_fd(m)) < 0)
2089                         return r;
2090
2091                 break;
2092
2093         case WATCH_NOTIFY:
2094
2095                 /* An incoming daemon notification event? */
2096                 if (ev->events != EPOLLIN)
2097                         return -EINVAL;
2098
2099                 if ((r = manager_process_notify_fd(m)) < 0)
2100                         return r;
2101
2102                 break;
2103
2104         case WATCH_FD:
2105
2106                 /* Some fd event, to be dispatched to the units */
2107                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
2108                 break;
2109
2110         case WATCH_UNIT_TIMER:
2111         case WATCH_JOB_TIMER: {
2112                 uint64_t v;
2113                 ssize_t k;
2114
2115                 /* Some timer event, to be dispatched to the units */
2116                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
2117
2118                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
2119                                 break;
2120
2121                         return k < 0 ? -errno : -EIO;
2122                 }
2123
2124                 if (w->type == WATCH_UNIT_TIMER)
2125                         UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
2126                 else
2127                         job_timer_event(w->data.job, v, w);
2128                 break;
2129         }
2130
2131         case WATCH_MOUNT:
2132                 /* Some mount table change, intended for the mount subsystem */
2133                 mount_fd_event(m, ev->events);
2134                 break;
2135
2136         case WATCH_UDEV:
2137                 /* Some notification from udev, intended for the device subsystem */
2138                 device_fd_event(m, ev->events);
2139                 break;
2140
2141         case WATCH_DBUS_WATCH:
2142                 bus_watch_event(m, w, ev->events);
2143                 break;
2144
2145         case WATCH_DBUS_TIMEOUT:
2146                 bus_timeout_event(m, w, ev->events);
2147                 break;
2148
2149         default:
2150                 assert_not_reached("Unknown epoll event type.");
2151         }
2152
2153         return 0;
2154 }
2155
2156 int manager_loop(Manager *m) {
2157         int r;
2158
2159         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
2160
2161         assert(m);
2162         m->exit_code = MANAGER_RUNNING;
2163
2164         /* Release the path cache */
2165         set_free_free(m->unit_path_cache);
2166         m->unit_path_cache = NULL;
2167
2168         /* There might still be some zombies hanging around from
2169          * before we were exec()'ed. Leat's reap them */
2170         if ((r = manager_dispatch_sigchld(m)) < 0)
2171                 return r;
2172
2173         while (m->exit_code == MANAGER_RUNNING) {
2174                 struct epoll_event event;
2175                 int n;
2176
2177                 if (!ratelimit_test(&rl)) {
2178                         /* Yay, something is going seriously wrong, pause a little */
2179                         log_warning("Looping too fast. Throttling execution a little.");
2180                         sleep(1);
2181                 }
2182
2183                 if (manager_dispatch_load_queue(m) > 0)
2184                         continue;
2185
2186                 if (manager_dispatch_run_queue(m) > 0)
2187                         continue;
2188
2189                 if (bus_dispatch(m) > 0)
2190                         continue;
2191
2192                 if (manager_dispatch_cleanup_queue(m) > 0)
2193                         continue;
2194
2195                 if (manager_dispatch_gc_queue(m) > 0)
2196                         continue;
2197
2198                 if (manager_dispatch_dbus_queue(m) > 0)
2199                         continue;
2200
2201                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
2202
2203                         if (errno == EINTR)
2204                                 continue;
2205
2206                         return -errno;
2207                 }
2208
2209                 assert(n == 1);
2210
2211                 if ((r = process_event(m, &event)) < 0)
2212                         return r;
2213         }
2214
2215         return m->exit_code;
2216 }
2217
2218 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
2219         char *n;
2220         Unit *u;
2221
2222         assert(m);
2223         assert(s);
2224         assert(_u);
2225
2226         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
2227                 return -EINVAL;
2228
2229         if (!(n = bus_path_unescape(s+31)))
2230                 return -ENOMEM;
2231
2232         u = manager_get_unit(m, n);
2233         free(n);
2234
2235         if (!u)
2236                 return -ENOENT;
2237
2238         *_u = u;
2239
2240         return 0;
2241 }
2242
2243 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
2244         Job *j;
2245         unsigned id;
2246         int r;
2247
2248         assert(m);
2249         assert(s);
2250         assert(_j);
2251
2252         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
2253                 return -EINVAL;
2254
2255         if ((r = safe_atou(s + 30, &id)) < 0)
2256                 return r;
2257
2258         if (!(j = manager_get_job(m, id)))
2259                 return -ENOENT;
2260
2261         *_j = j;
2262
2263         return 0;
2264 }
2265
2266 void manager_send_unit_audit(Manager *m, Unit *u, int type, bool success) {
2267
2268 #ifdef HAVE_AUDIT
2269         char *p;
2270
2271         if (m->audit_fd < 0)
2272                 return;
2273
2274         /* Don't generate audit events if the service was already
2275          * started and we're just deserializing */
2276         if (m->n_deserializing > 0)
2277                 return;
2278
2279         if (!(p = unit_name_to_prefix_and_instance(u->meta.id))) {
2280                 log_error("Failed to allocate unit name for audit message: %s", strerror(ENOMEM));
2281                 return;
2282         }
2283
2284         if (audit_log_user_comm_message(m->audit_fd, type, "", p, NULL, NULL, NULL, success) < 0)
2285                 log_error("Failed to send audit message: %m");
2286
2287         free(p);
2288 #endif
2289
2290 }
2291
2292 void manager_dispatch_bus_name_owner_changed(
2293                 Manager *m,
2294                 const char *name,
2295                 const char* old_owner,
2296                 const char *new_owner) {
2297
2298         Unit *u;
2299
2300         assert(m);
2301         assert(name);
2302
2303         if (!(u = hashmap_get(m->watch_bus, name)))
2304                 return;
2305
2306         UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
2307 }
2308
2309 void manager_dispatch_bus_query_pid_done(
2310                 Manager *m,
2311                 const char *name,
2312                 pid_t pid) {
2313
2314         Unit *u;
2315
2316         assert(m);
2317         assert(name);
2318         assert(pid >= 1);
2319
2320         if (!(u = hashmap_get(m->watch_bus, name)))
2321                 return;
2322
2323         UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
2324 }
2325
2326 int manager_open_serialization(Manager *m, FILE **_f) {
2327         char *path;
2328         mode_t saved_umask;
2329         int fd;
2330         FILE *f;
2331
2332         assert(_f);
2333
2334         if (m->running_as == MANAGER_SYSTEM) {
2335                 mkdir_p("/dev/.systemd", 0755);
2336
2337                 if (asprintf(&path, "/dev/.systemd/dump-%lu-XXXXXX", (unsigned long) getpid()) < 0)
2338                         return -ENOMEM;
2339         } else {
2340                 if (asprintf(&path, "/tmp/systemd-dump-%lu-XXXXXX", (unsigned long) getpid()) < 0)
2341                         return -ENOMEM;
2342         }
2343
2344         saved_umask = umask(0077);
2345         fd = mkostemp(path, O_RDWR|O_CLOEXEC);
2346         umask(saved_umask);
2347
2348         if (fd < 0) {
2349                 free(path);
2350                 return -errno;
2351         }
2352
2353         unlink(path);
2354
2355         log_debug("Serializing state to %s", path);
2356         free(path);
2357
2358         if (!(f = fdopen(fd, "w+")) < 0)
2359                 return -errno;
2360
2361         *_f = f;
2362
2363         return 0;
2364 }
2365
2366 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
2367         Iterator i;
2368         Unit *u;
2369         const char *t;
2370         int r;
2371
2372         assert(m);
2373         assert(f);
2374         assert(fds);
2375
2376         fprintf(f, "startup-timestamp=%llu %llu\n\n",
2377                 (unsigned long long) m->startup_timestamp.realtime,
2378                 (unsigned long long) m->startup_timestamp.monotonic);
2379
2380         HASHMAP_FOREACH_KEY(u, t, m->units, i) {
2381                 if (u->meta.id != t)
2382                         continue;
2383
2384                 if (!unit_can_serialize(u))
2385                         continue;
2386
2387                 /* Start marker */
2388                 fputs(u->meta.id, f);
2389                 fputc('\n', f);
2390
2391                 if ((r = unit_serialize(u, f, fds)) < 0)
2392                         return r;
2393         }
2394
2395         if (ferror(f))
2396                 return -EIO;
2397
2398         return 0;
2399 }
2400
2401 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2402         int r = 0;
2403
2404         assert(m);
2405         assert(f);
2406
2407         log_debug("Deserializing state...");
2408
2409         m->n_deserializing ++;
2410
2411         for (;;) {
2412                 char line[1024], *l;
2413
2414                 if (!fgets(line, sizeof(line), f)) {
2415                         if (feof(f))
2416                                 r = 0;
2417                         else
2418                                 r = -errno;
2419
2420                         goto finish;
2421                 }
2422
2423                 char_array_0(line);
2424                 l = strstrip(line);
2425
2426                 if (l[0] == 0)
2427                         break;
2428
2429                 if (startswith(l, "startup-timestamp=")) {
2430                         unsigned long long a, b;
2431
2432                         if (sscanf(l+18, "%lli %llu", &a, &b) != 2)
2433                                 log_debug("Failed to parse startup timestamp value %s", l+18);
2434                         else {
2435                                 m->startup_timestamp.realtime = a;
2436                                 m->startup_timestamp.monotonic = b;
2437                         }
2438                 } else
2439                         log_debug("Unknown serialization item '%s'", l);
2440         }
2441
2442         for (;;) {
2443                 Unit *u;
2444                 char name[UNIT_NAME_MAX+2];
2445
2446                 /* Start marker */
2447                 if (!fgets(name, sizeof(name), f)) {
2448                         if (feof(f))
2449                                 r = 0;
2450                         else
2451                                 r = -errno;
2452
2453                         goto finish;
2454                 }
2455
2456                 char_array_0(name);
2457
2458                 if ((r = manager_load_unit(m, strstrip(name), NULL, NULL, &u)) < 0)
2459                         goto finish;
2460
2461                 if ((r = unit_deserialize(u, f, fds)) < 0)
2462                         goto finish;
2463         }
2464
2465 finish:
2466         if (ferror(f)) {
2467                 r = -EIO;
2468                 goto finish;
2469         }
2470
2471         assert(m->n_deserializing > 0);
2472         m->n_deserializing --;
2473
2474         return r;
2475 }
2476
2477 int manager_reload(Manager *m) {
2478         int r, q;
2479         FILE *f;
2480         FDSet *fds;
2481
2482         assert(m);
2483
2484         if ((r = manager_open_serialization(m, &f)) < 0)
2485                 return r;
2486
2487         if (!(fds = fdset_new())) {
2488                 r = -ENOMEM;
2489                 goto finish;
2490         }
2491
2492         if ((r = manager_serialize(m, f, fds)) < 0)
2493                 goto finish;
2494
2495         if (fseeko(f, 0, SEEK_SET) < 0) {
2496                 r = -errno;
2497                 goto finish;
2498         }
2499
2500         /* From here on there is no way back. */
2501         manager_clear_jobs_and_units(m);
2502
2503         /* Find new unit paths */
2504         lookup_paths_free(&m->lookup_paths);
2505         if ((q = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
2506                 r = q;
2507
2508         m->n_deserializing ++;
2509
2510         /* First, enumerate what we can from all config files */
2511         if ((q = manager_enumerate(m)) < 0)
2512                 r = q;
2513
2514         /* Second, deserialize our stored data */
2515         if ((q = manager_deserialize(m, f, fds)) < 0)
2516                 r = q;
2517
2518         fclose(f);
2519         f = NULL;
2520
2521         /* Third, fire things up! */
2522         if ((q = manager_coldplug(m)) < 0)
2523                 r = q;
2524
2525         assert(m->n_deserializing > 0);
2526         m->n_deserializing ++;
2527
2528 finish:
2529         if (f)
2530                 fclose(f);
2531
2532         if (fds)
2533                 fdset_free(fds);
2534
2535         return r;
2536 }
2537
2538 bool manager_is_booting_or_shutting_down(Manager *m) {
2539         Unit *u;
2540
2541         assert(m);
2542
2543         /* Is the initial job still around? */
2544         if (manager_get_job(m, 1))
2545                 return true;
2546
2547         /* Is there a job for the shutdown target? */
2548         if (((u = manager_get_unit(m, SPECIAL_SHUTDOWN_TARGET))))
2549                 return !!u->meta.job;
2550
2551         return false;
2552 }
2553
2554 void manager_reset_maintenance(Manager *m) {
2555         Unit *u;
2556         Iterator i;
2557
2558         assert(m);
2559
2560         HASHMAP_FOREACH(u, m->units, i)
2561                 unit_reset_maintenance(u);
2562 }
2563
2564 int manager_set_console(Manager *m, const char *console) {
2565         char *c;
2566
2567         assert(m);
2568
2569         if (!(c = strdup(console)))
2570                 return -ENOMEM;
2571
2572         free(m->console);
2573         m->console = c;
2574
2575         log_debug("Using kernel console %s", c);
2576
2577         return 0;
2578 }
2579
2580 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2581         [MANAGER_SYSTEM] = "system",
2582         [MANAGER_SESSION] = "session"
2583 };
2584
2585 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);