src/manager.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <assert.h>
  23 #include <errno.h>
  24 #include <string.h>
  25 #include <sys/epoll.h>
  26 #include <signal.h>
  27 #include <sys/signalfd.h>
  28 #include <sys/wait.h>
  29 #include <unistd.h>
  30 #include <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
  61 /* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
  62 #define GC_QUEUE_ENTRIES_MAX 16
  63
  64 /* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
  65 #define GC_QUEUE_USEC_MAX (10*USEC_PER_SEC)
  66
  67 /* Where clients shall send notification messages to */
  68 #define NOTIFY_SOCKET "/org/freedesktop/systemd1/notify"
  69
  70 static int manager_setup_notify(Manager *m) {
  71         union {
  72                 struct sockaddr sa;
  73                 struct sockaddr_un un;
  74         } sa;
  75         struct epoll_event ev;
  76         int one = 1;
  77
  78         assert(m);
  79
  80         m->notify_watch.type = WATCH_NOTIFY;
  81         if ((m->notify_watch.fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) {
  82                 log_error("Failed to allocate notification socket: %m");
  83                 return -errno;
  84         }
  85
  86         zero(sa);
  87         sa.sa.sa_family = AF_UNIX;
  88
  89         if (getpid() != 1)
  90                 snprintf(sa.un.sun_path+1, sizeof(sa.un.sun_path)-1, NOTIFY_SOCKET "/%llu", random_ull());
  91         else
  92                 strncpy(sa.un.sun_path+1, NOTIFY_SOCKET, sizeof(sa.un.sun_path)-1);
  93
  94         if (bind(m->notify_watch.fd, &sa.sa, sizeof(sa_family_t) + 1 + strlen(sa.un.sun_path+1)) < 0) {
  95                 log_error("bind() failed: %m");
  96                 return -errno;
  97         }
  98
  99         if (setsockopt(m->notify_watch.fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) {
 100                 log_error("SO_PASSCRED failed: %m");
 101                 return -errno;
 102         }
 103
 104         zero(ev);
 105         ev.events = EPOLLIN;
 106         ev.data.ptr = &m->notify_watch;
 107
 108         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->notify_watch.fd, &ev) < 0)
 109                 return -errno;
 110
 111         if (!(m->notify_socket = strdup(sa.un.sun_path+1)))
 112                 return -ENOMEM;
 113
 114         return 0;
 115 }
 116
 117 static int enable_special_signals(Manager *m) {
 118         char fd;
 119
 120         assert(m);
 121
 122         /* Enable that we get SIGINT on control-alt-del */
 123         if (reboot(RB_DISABLE_CAD) < 0)
 124                 log_warning("Failed to enable ctrl-alt-del handling: %m");
 125
 126         if ((fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY)) < 0)
 127                 log_warning("Failed to open /dev/tty0: %m");
 128         else {
 129                 /* Enable that we get SIGWINCH on kbrequest */
 130                 if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
 131                         log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
 132
 133                 close_nointr_nofail(fd);
 134         }
 135
 136         return 0;
 137 }
 138
 139 static int manager_setup_signals(Manager *m) {
 140         sigset_t mask;
 141         struct epoll_event ev;
 142         struct sigaction sa;
 143
 144         assert(m);
 145
 146         /* We are not interested in SIGSTOP and friends. */
 147         zero(sa);
 148         sa.sa_handler = SIG_DFL;
 149         sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
 150         assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
 151
 152         assert_se(sigemptyset(&mask) == 0);
 153
 154         sigset_add_many(&mask,
 155                         SIGCHLD,     /* Child died */
 156                         SIGTERM,     /* Reexecute daemon */
 157                         SIGHUP,      /* Reload configuration */
 158                         SIGUSR1,     /* systemd/upstart: reconnect to D-Bus */
 159                         SIGUSR2,     /* systemd: dump status */
 160                         SIGINT,      /* Kernel sends us this on control-alt-del */
 161                         SIGWINCH,    /* Kernel sends us this on kbrequest (alt-arrowup) */
 162                         SIGPWR,      /* Some kernel drivers and upsd send us this on power failure */
 163                         SIGRTMIN+0,  /* systemd: start default.target */
 164                         SIGRTMIN+1,  /* systemd: start rescue.target */
 165                         SIGRTMIN+2,  /* systemd: isolate emergency.target */
 166                         SIGRTMIN+3,  /* systemd: start halt.target */
 167                         SIGRTMIN+4,  /* systemd: start poweroff.target */
 168                         SIGRTMIN+5,  /* systemd: start reboot.target */
 169                         -1);
 170         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 171
 172         m->signal_watch.type = WATCH_SIGNAL;
 173         if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
 174                 return -errno;
 175
 176         zero(ev);
 177         ev.events = EPOLLIN;
 178         ev.data.ptr = &m->signal_watch;
 179
 180         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
 181                 return -errno;
 182
 183         if (m->running_as == MANAGER_SYSTEM)
 184                 return enable_special_signals(m);
 185
 186         return 0;
 187 }
 188
 189 int manager_new(ManagerRunningAs running_as, Manager **_m) {
 190         Manager *m;
 191         int r = -ENOMEM;
 192
 193         assert(_m);
 194         assert(running_as >= 0);
 195         assert(running_as < _MANAGER_RUNNING_AS_MAX);
 196
 197         if (!(m = new0(Manager, 1)))
 198                 return -ENOMEM;
 199
 200         dual_timestamp_get(&m->startup_timestamp);
 201
 202         m->running_as = running_as;
 203         m->name_data_slot = m->subscribed_data_slot = -1;
 204         m->exit_code = _MANAGER_EXIT_CODE_INVALID;
 205         m->pin_cgroupfs_fd = -1;
 206
 207 #ifdef HAVE_AUDIT
 208         m->audit_fd = -1;
 209 #endif
 210
 211         m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
 212         m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
 213
 214         if (!(m->environment = strv_copy(environ)))
 215                 goto fail;
 216
 217         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
 218                 goto fail;
 219
 220         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 221                 goto fail;
 222
 223         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 224                 goto fail;
 225
 226         if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
 227                 goto fail;
 228
 229         if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
 230                 goto fail;
 231
 232         if (!(m->watch_bus = hashmap_new(string_hash_func, string_compare_func)))
 233                 goto fail;
 234
 235         if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
 236                 goto fail;
 237
 238         if ((r = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
 239                 goto fail;
 240
 241         if ((r = manager_setup_signals(m)) < 0)
 242                 goto fail;
 243
 244         if ((r = manager_setup_cgroup(m)) < 0)
 245                 goto fail;
 246
 247         if ((r = manager_setup_notify(m)) < 0)
 248                 goto fail;
 249
 250         /* Try to connect to the busses, if possible. */
 251         if ((r = bus_init(m)) < 0)
 252                 goto fail;
 253
 254 #ifdef HAVE_AUDIT
 255         if ((m->audit_fd = audit_open()) < 0)
 256                 log_error("Failed to connect to audit log: %m");
 257 #endif
 258
 259         *_m = m;
 260         return 0;
 261
 262 fail:
 263         manager_free(m);
 264         return r;
 265 }
 266
 267 static unsigned manager_dispatch_cleanup_queue(Manager *m) {
 268         Meta *meta;
 269         unsigned n = 0;
 270
 271         assert(m);
 272
 273         while ((meta = m->cleanup_queue)) {
 274                 assert(meta->in_cleanup_queue);
 275
 276                 unit_free((Unit*) meta);
 277                 n++;
 278         }
 279
 280         return n;
 281 }
 282
 283 enum {
 284         GC_OFFSET_IN_PATH,  /* This one is on the path we were travelling */
 285         GC_OFFSET_UNSURE,   /* No clue */
 286         GC_OFFSET_GOOD,     /* We still need this unit */
 287         GC_OFFSET_BAD,      /* We don't need this unit anymore */
 288         _GC_OFFSET_MAX
 289 };
 290
 291 static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
 292         Iterator i;
 293         Unit *other;
 294         bool is_bad;
 295
 296         assert(u);
 297
 298         if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
 299             u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
 300             u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
 301                 return;
 302
 303         if (u->meta.in_cleanup_queue)
 304                 goto bad;
 305
 306         if (unit_check_gc(u))
 307                 goto good;
 308
 309         u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
 310
 311         is_bad = true;
 312
 313         SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
 314                 unit_gc_sweep(other, gc_marker);
 315
 316                 if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
 317                         goto good;
 318
 319                 if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
 320                         is_bad = false;
 321         }
 322
 323         if (is_bad)
 324                 goto bad;
 325
 326         /* We were unable to find anything out about this entry, so
 327          * let's investigate it later */
 328         u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
 329         unit_add_to_gc_queue(u);
 330         return;
 331
 332 bad:
 333         /* We definitely know that this one is not useful anymore, so
 334          * let's mark it for deletion */
 335         u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
 336         unit_add_to_cleanup_queue(u);
 337         return;
 338
 339 good:
 340         u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
 341 }
 342
 343 static unsigned manager_dispatch_gc_queue(Manager *m) {
 344         Meta *meta;
 345         unsigned n = 0;
 346         unsigned gc_marker;
 347
 348         assert(m);
 349
 350         if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
 351             (m->gc_queue_timestamp <= 0 ||
 352              (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
 353                 return 0;
 354
 355         log_debug("Running GC...");
 356
 357         m->gc_marker += _GC_OFFSET_MAX;
 358         if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
 359                 m->gc_marker = 1;
 360
 361         gc_marker = m->gc_marker;
 362
 363         while ((meta = m->gc_queue)) {
 364                 assert(meta->in_gc_queue);
 365
 366                 unit_gc_sweep((Unit*) meta, gc_marker);
 367
 368                 LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
 369                 meta->in_gc_queue = false;
 370
 371                 n++;
 372
 373                 if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
 374                     meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
 375                         log_debug("Collecting %s", meta->id);
 376                         meta->gc_marker = gc_marker + GC_OFFSET_BAD;
 377                         unit_add_to_cleanup_queue((Unit*) meta);
 378                 }
 379         }
 380
 381         m->n_in_gc_queue = 0;
 382         m->gc_queue_timestamp = 0;
 383
 384         return n;
 385 }
 386
 387 static void manager_clear_jobs_and_units(Manager *m) {
 388         Job *j;
 389         Unit *u;
 390
 391         assert(m);
 392
 393         while ((j = hashmap_first(m->transaction_jobs)))
 394                 job_free(j);
 395
 396         while ((u = hashmap_first(m->units)))
 397                 unit_free(u);
 398
 399         manager_dispatch_cleanup_queue(m);
 400
 401         assert(!m->load_queue);
 402         assert(!m->run_queue);
 403         assert(!m->dbus_unit_queue);
 404         assert(!m->dbus_job_queue);
 405         assert(!m->cleanup_queue);
 406         assert(!m->gc_queue);
 407
 408         assert(hashmap_isempty(m->transaction_jobs));
 409         assert(hashmap_isempty(m->jobs));
 410         assert(hashmap_isempty(m->units));
 411 }
 412
 413 void manager_free(Manager *m) {
 414         UnitType c;
 415
 416         assert(m);
 417
 418         manager_clear_jobs_and_units(m);
 419
 420         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 421                 if (unit_vtable[c]->shutdown)
 422                         unit_vtable[c]->shutdown(m);
 423
 424         /* If we reexecute ourselves, we keep the root cgroup
 425          * around */
 426         manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
 427
 428         bus_done(m);
 429
 430         hashmap_free(m->units);
 431         hashmap_free(m->jobs);
 432         hashmap_free(m->transaction_jobs);
 433         hashmap_free(m->watch_pids);
 434         hashmap_free(m->watch_bus);
 435
 436         if (m->epoll_fd >= 0)
 437                 close_nointr_nofail(m->epoll_fd);
 438         if (m->signal_watch.fd >= 0)
 439                 close_nointr_nofail(m->signal_watch.fd);
 440         if (m->notify_watch.fd >= 0)
 441                 close_nointr_nofail(m->notify_watch.fd);
 442
 443 #ifdef HAVE_AUDIT
 444         if (m->audit_fd >= 0)
 445                 audit_close(m->audit_fd);
 446 #endif
 447
 448         free(m->notify_socket);
 449
 450         lookup_paths_free(&m->lookup_paths);
 451         strv_free(m->environment);
 452
 453         hashmap_free(m->cgroup_bondings);
 454         set_free_free(m->unit_path_cache);
 455
 456         free(m);
 457 }
 458
 459 int manager_enumerate(Manager *m) {
 460         int r = 0, q;
 461         UnitType c;
 462
 463         assert(m);
 464
 465         /* Let's ask every type to load all units from disk/kernel
 466          * that it might know */
 467         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 468                 if (unit_vtable[c]->enumerate)
 469                         if ((q = unit_vtable[c]->enumerate(m)) < 0)
 470                                 r = q;
 471
 472         manager_dispatch_load_queue(m);
 473         return r;
 474 }
 475
 476 int manager_coldplug(Manager *m) {
 477         int r = 0, q;
 478         Iterator i;
 479         Unit *u;
 480         char *k;
 481
 482         assert(m);
 483
 484         /* Then, let's set up their initial state. */
 485         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 486
 487                 /* ignore aliases */
 488                 if (u->meta.id != k)
 489                         continue;
 490
 491                 if ((q = unit_coldplug(u)) < 0)
 492                         r = q;
 493         }
 494
 495         return r;
 496 }
 497
 498 static void manager_build_unit_path_cache(Manager *m) {
 499         char **i;
 500         DIR *d = NULL;
 501         int r;
 502
 503         assert(m);
 504
 505         set_free_free(m->unit_path_cache);
 506
 507         if (!(m->unit_path_cache = set_new(string_hash_func, string_compare_func))) {
 508                 log_error("Failed to allocate unit path cache.");
 509                 return;
 510         }
 511
 512         /* This simply builds a list of files we know exist, so that
 513          * we don't always have to go to disk */
 514
 515         STRV_FOREACH(i, m->lookup_paths.unit_path) {
 516                 struct dirent *de;
 517
 518                 if (!(d = opendir(*i))) {
 519                         log_error("Failed to open directory: %m");
 520                         continue;
 521                 }
 522
 523                 while ((de = readdir(d))) {
 524                         char *p;
 525
 526                         if (ignore_file(de->d_name))
 527                                 continue;
 528
 529                         if (asprintf(&p, "%s/%s", streq(*i, "/") ? "" : *i, de->d_name) < 0) {
 530                                 r = -ENOMEM;
 531                                 goto fail;
 532                         }
 533
 534                         if ((r = set_put(m->unit_path_cache, p)) < 0) {
 535                                 free(p);
 536                                 goto fail;
 537                         }
 538                 }
 539
 540                 closedir(d);
 541                 d = NULL;
 542         }
 543
 544         return;
 545
 546 fail:
 547         log_error("Failed to build unit path cache: %s", strerror(-r));
 548
 549         set_free_free(m->unit_path_cache);
 550         m->unit_path_cache = NULL;
 551
 552         if (d)
 553                 closedir(d);
 554 }
 555
 556 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 557         int r, q;
 558
 559         assert(m);
 560
 561         manager_build_unit_path_cache(m);
 562
 563         /* If we will deserialize make sure that during enumeration
 564          * this is already known, so we increase the counter here
 565          * already */
 566         if (serialization)
 567                 m->n_deserializing ++;
 568
 569         /* First, enumerate what we can from all config files */
 570         r = manager_enumerate(m);
 571
 572         /* Second, deserialize if there is something to deserialize */
 573         if (serialization)
 574                 if ((q = manager_deserialize(m, serialization, fds)) < 0)
 575                         r = q;
 576
 577         /* Third, fire things up! */
 578         if ((q = manager_coldplug(m)) < 0)
 579                 r = q;
 580
 581         if (serialization) {
 582                 assert(m->n_deserializing > 0);
 583                 m->n_deserializing --;
 584         }
 585
 586         return r;
 587 }
 588
 589 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
 590         assert(m);
 591         assert(j);
 592
 593         /* Deletes one job from the transaction */
 594
 595         manager_transaction_unlink_job(m, j, delete_dependencies);
 596
 597         if (!j->installed)
 598                 job_free(j);
 599 }
 600
 601 static void transaction_delete_unit(Manager *m, Unit *u) {
 602         Job *j;
 603
 604         /* Deletes all jobs associated with a certain unit from the
 605          * transaction */
 606
 607         while ((j = hashmap_get(m->transaction_jobs, u)))
 608                 transaction_delete_job(m, j, true);
 609 }
 610
 611 static void transaction_clean_dependencies(Manager *m) {
 612         Iterator i;
 613         Job *j;
 614
 615         assert(m);
 616
 617         /* Drops all dependencies of all installed jobs */
 618
 619         HASHMAP_FOREACH(j, m->jobs, i) {
 620                 while (j->subject_list)
 621                         job_dependency_free(j->subject_list);
 622                 while (j->object_list)
 623                         job_dependency_free(j->object_list);
 624         }
 625
 626         assert(!m->transaction_anchor);
 627 }
 628
 629 static void transaction_abort(Manager *m) {
 630         Job *j;
 631
 632         assert(m);
 633
 634         while ((j = hashmap_first(m->transaction_jobs)))
 635                 if (j->installed)
 636                         transaction_delete_job(m, j, true);
 637                 else
 638                         job_free(j);
 639
 640         assert(hashmap_isempty(m->transaction_jobs));
 641
 642         transaction_clean_dependencies(m);
 643 }
 644
 645 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 646         JobDependency *l;
 647
 648         assert(m);
 649
 650         /* A recursive sweep through the graph that marks all units
 651          * that matter to the anchor job, i.e. are directly or
 652          * indirectly a dependency of the anchor job via paths that
 653          * are fully marked as mattering. */
 654
 655         if (j)
 656                 l = j->subject_list;
 657         else
 658                 l = m->transaction_anchor;
 659
 660         LIST_FOREACH(subject, l, l) {
 661
 662                 /* This link does not matter */
 663                 if (!l->matters)
 664                         continue;
 665
 666                 /* This unit has already been marked */
 667                 if (l->object->generation == generation)
 668                         continue;
 669
 670                 l->object->matters_to_anchor = true;
 671                 l->object->generation = generation;
 672
 673                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 674         }
 675 }
 676
 677 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 678         JobDependency *l, *last;
 679
 680         assert(j);
 681         assert(other);
 682         assert(j->unit == other->unit);
 683         assert(!j->installed);
 684
 685         /* Merges 'other' into 'j' and then deletes j. */
 686
 687         j->type = t;
 688         j->state = JOB_WAITING;
 689         j->override = j->override || other->override;
 690
 691         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 692
 693         /* Patch us in as new owner of the JobDependency objects */
 694         last = NULL;
 695         LIST_FOREACH(subject, l, other->subject_list) {
 696                 assert(l->subject == other);
 697                 l->subject = j;
 698                 last = l;
 699         }
 700
 701         /* Merge both lists */
 702         if (last) {
 703                 last->subject_next = j->subject_list;
 704                 if (j->subject_list)
 705                         j->subject_list->subject_prev = last;
 706                 j->subject_list = other->subject_list;
 707         }
 708
 709         /* Patch us in as new owner of the JobDependency objects */
 710         last = NULL;
 711         LIST_FOREACH(object, l, other->object_list) {
 712                 assert(l->object == other);
 713                 l->object = j;
 714                 last = l;
 715         }
 716
 717         /* Merge both lists */
 718         if (last) {
 719                 last->object_next = j->object_list;
 720                 if (j->object_list)
 721                         j->object_list->object_prev = last;
 722                 j->object_list = other->object_list;
 723         }
 724
 725         /* Kill the other job */
 726         other->subject_list = NULL;
 727         other->object_list = NULL;
 728         transaction_delete_job(m, other, true);
 729 }
 730 static bool job_is_conflicted_by(Job *j) {
 731         JobDependency *l;
 732
 733         assert(j);
 734
 735         /* Returns true if this job is pulled in by a least one
 736          * ConflictedBy dependency. */
 737
 738         LIST_FOREACH(object, l, j->object_list)
 739                 if (l->conflicts)
 740                         return true;
 741
 742         return false;
 743 }
 744
 745 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 746         Job *k;
 747
 748         assert(j);
 749
 750         /* Tries to delete one item in the linked list
 751          * j->transaction_next->transaction_next->... that conflicts
 752          * whith another one, in an attempt to make an inconsistent
 753          * transaction work. */
 754
 755         /* We rely here on the fact that if a merged with b does not
 756          * merge with c, either a or b merge with c neither */
 757         LIST_FOREACH(transaction, j, j)
 758                 LIST_FOREACH(transaction, k, j->transaction_next) {
 759                         Job *d;
 760
 761                         /* Is this one mergeable? Then skip it */
 762                         if (job_type_is_mergeable(j->type, k->type))
 763                                 continue;
 764
 765                         /* Ok, we found two that conflict, let's see if we can
 766                          * drop one of them */
 767                         if (!j->matters_to_anchor && !k->matters_to_anchor) {
 768
 769                                 /* Both jobs don't matter, so let's
 770                                  * find the one that is smarter to
 771                                  * remove. Let's think positive and
 772                                  * rather remove stops then starts --
 773                                  * except if something is being
 774                                  * stopped because it is conflicted by
 775                                  * another unit in which case we
 776                                  * rather remove the start. */
 777
 778                                 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)));
 779                                 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)));
 780
 781                                 if (j->type == JOB_STOP) {
 782
 783                                         if (job_is_conflicted_by(j))
 784                                                 d = k;
 785                                         else
 786                                                 d = j;
 787
 788                                 } else if (k->type == JOB_STOP) {
 789
 790                                         if (job_is_conflicted_by(k))
 791                                                 d = j;
 792                                         else
 793                                                 d = k;
 794                                 } else
 795                                         d = j;
 796
 797                         } else if (!j->matters_to_anchor)
 798                                 d = j;
 799                         else if (!k->matters_to_anchor)
 800                                 d = k;
 801                         else
 802                                 return -ENOEXEC;
 803
 804                         /* Ok, we can drop one, so let's do so. */
 805                         log_debug("Fixing conflicting jobs by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
 806                         transaction_delete_job(m, d, true);
 807                         return 0;
 808                 }
 809
 810         return -EINVAL;
 811 }
 812
 813 static int transaction_merge_jobs(Manager *m, DBusError *e) {
 814         Job *j;
 815         Iterator i;
 816         int r;
 817
 818         assert(m);
 819
 820         /* First step, check whether any of the jobs for one specific
 821          * task conflict. If so, try to drop one of them. */
 822         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 823                 JobType t;
 824                 Job *k;
 825
 826                 t = j->type;
 827                 LIST_FOREACH(transaction, k, j->transaction_next) {
 828                         if (job_type_merge(&t, k->type) >= 0)
 829                                 continue;
 830
 831                         /* OK, we could not merge all jobs for this
 832                          * action. Let's see if we can get rid of one
 833                          * of them */
 834
 835                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 836                                 /* Ok, we managed to drop one, now
 837                                  * let's ask our callers to call us
 838                                  * again after garbage collecting */
 839                                 return -EAGAIN;
 840
 841                         /* We couldn't merge anything. Failure */
 842                         dbus_set_error(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING, "Transaction contains conflicting jobs '%s' and '%s' for %s. Probably contradicting requirement dependencies configured.",
 843                                        job_type_to_string(t), job_type_to_string(k->type), k->unit->meta.id);
 844                         return r;
 845                 }
 846         }
 847
 848         /* Second step, merge the jobs. */
 849         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 850                 JobType t = j->type;
 851                 Job *k;
 852
 853                 /* Merge all transactions */
 854                 LIST_FOREACH(transaction, k, j->transaction_next)
 855                         assert_se(job_type_merge(&t, k->type) == 0);
 856
 857                 /* If an active job is mergeable, merge it too */
 858                 if (j->unit->meta.job)
 859                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 860
 861                 while ((k = j->transaction_next)) {
 862                         if (j->installed) {
 863                                 transaction_merge_and_delete_job(m, k, j, t);
 864                                 j = k;
 865                         } else
 866                                 transaction_merge_and_delete_job(m, j, k, t);
 867                 }
 868
 869                 assert(!j->transaction_next);
 870                 assert(!j->transaction_prev);
 871         }
 872
 873         return 0;
 874 }
 875
 876 static void transaction_drop_redundant(Manager *m) {
 877         bool again;
 878
 879         assert(m);
 880
 881         /* Goes through the transaction and removes all jobs that are
 882          * a noop */
 883
 884         do {
 885                 Job *j;
 886                 Iterator i;
 887
 888                 again = false;
 889
 890                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 891                         bool changes_something = false;
 892                         Job *k;
 893
 894                         LIST_FOREACH(transaction, k, j) {
 895
 896                                 if (!job_is_anchor(k) &&
 897                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
 898                                         continue;
 899
 900                                 changes_something = true;
 901                                 break;
 902                         }
 903
 904                         if (changes_something)
 905                                 continue;
 906
 907                         log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
 908                         transaction_delete_job(m, j, false);
 909                         again = true;
 910                         break;
 911                 }
 912
 913         } while (again);
 914 }
 915
 916 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 917         assert(u);
 918         assert(!j->transaction_prev);
 919
 920         /* Checks whether at least one of the jobs for this unit
 921          * matters to the anchor. */
 922
 923         LIST_FOREACH(transaction, j, j)
 924                 if (j->matters_to_anchor)
 925                         return true;
 926
 927         return false;
 928 }
 929
 930 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation, DBusError *e) {
 931         Iterator i;
 932         Unit *u;
 933         int r;
 934
 935         assert(m);
 936         assert(j);
 937         assert(!j->transaction_prev);
 938
 939         /* Does a recursive sweep through the ordering graph, looking
 940          * for a cycle. If we find cycle we try to break it. */
 941
 942         /* Have we seen this before? */
 943         if (j->generation == generation) {
 944                 Job *k, *delete;
 945
 946                 /* If the marker is NULL we have been here already and
 947                  * decided the job was loop-free from here. Hence
 948                  * shortcut things and return right-away. */
 949                 if (!j->marker)
 950                         return 0;
 951
 952                 /* So, the marker is not NULL and we already have been
 953                  * here. We have a cycle. Let's try to break it. We go
 954                  * backwards in our path and try to find a suitable
 955                  * job to remove. We use the marker to find our way
 956                  * back, since smart how we are we stored our way back
 957                  * in there. */
 958                 log_warning("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 959
 960                 delete = NULL;
 961                 for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) {
 962
 963                         log_info("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 964
 965                         if (!delete &&
 966                             !k->installed &&
 967                             !unit_matters_to_anchor(k->unit, k)) {
 968                                 /* Ok, we can drop this one, so let's
 969                                  * do so. */
 970                                 delete = k;
 971                         }
 972
 973                         /* Check if this in fact was the beginning of
 974                          * the cycle */
 975                         if (k == j)
 976                                 break;
 977                 }
 978
 979
 980                 if (delete) {
 981                         log_warning("Breaking ordering cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 982                         transaction_delete_unit(m, delete->unit);
 983                         return -EAGAIN;
 984                 }
 985
 986                 log_error("Unable to break cycle");
 987
 988                 dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See logs for details.");
 989                 return -ENOEXEC;
 990         }
 991
 992         /* Make the marker point to where we come from, so that we can
 993          * find our way backwards if we want to break a cycle. We use
 994          * a special marker for the beginning: we point to
 995          * ourselves. */
 996         j->marker = from ? from : j;
 997         j->generation = generation;
 998
 999         /* We assume that the the dependencies are bidirectional, and
1000          * hence can ignore UNIT_AFTER */
1001         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
1002                 Job *o;
1003
1004                 /* Is there a job for this unit? */
1005                 if (!(o = hashmap_get(m->transaction_jobs, u)))
1006
1007                         /* Ok, there is no job for this in the
1008                          * transaction, but maybe there is already one
1009                          * running? */
1010                         if (!(o = u->meta.job))
1011                                 continue;
1012
1013                 if ((r = transaction_verify_order_one(m, o, j, generation, e)) < 0)
1014                         return r;
1015         }
1016
1017         /* Ok, let's backtrack, and remember that this entry is not on
1018          * our path anymore. */
1019         j->marker = NULL;
1020
1021         return 0;
1022 }
1023
1024 static int transaction_verify_order(Manager *m, unsigned *generation, DBusError *e) {
1025         Job *j;
1026         int r;
1027         Iterator i;
1028         unsigned g;
1029
1030         assert(m);
1031         assert(generation);
1032
1033         /* Check if the ordering graph is cyclic. If it is, try to fix
1034          * that up by dropping one of the jobs. */
1035
1036         g = (*generation)++;
1037
1038         HASHMAP_FOREACH(j, m->transaction_jobs, i)
1039                 if ((r = transaction_verify_order_one(m, j, NULL, g, e)) < 0)
1040                         return r;
1041
1042         return 0;
1043 }
1044
1045 static void transaction_collect_garbage(Manager *m) {
1046         bool again;
1047
1048         assert(m);
1049
1050         /* Drop jobs that are not required by any other job */
1051
1052         do {
1053                 Iterator i;
1054                 Job *j;
1055
1056                 again = false;
1057
1058                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1059                         if (j->object_list)
1060                                 continue;
1061
1062                         log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
1063                         transaction_delete_job(m, j, true);
1064                         again = true;
1065                         break;
1066                 }
1067
1068         } while (again);
1069 }
1070
1071 static int transaction_is_destructive(Manager *m, DBusError *e) {
1072         Iterator i;
1073         Job *j;
1074
1075         assert(m);
1076
1077         /* Checks whether applying this transaction means that
1078          * existing jobs would be replaced */
1079
1080         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1081
1082                 /* Assume merged */
1083                 assert(!j->transaction_prev);
1084                 assert(!j->transaction_next);
1085
1086                 if (j->unit->meta.job &&
1087                     j->unit->meta.job != j &&
1088                     !job_type_is_superset(j->type, j->unit->meta.job->type)) {
1089
1090                         dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive.");
1091                         return -EEXIST;
1092                 }
1093         }
1094
1095         return 0;
1096 }
1097
1098 static void transaction_minimize_impact(Manager *m) {
1099         bool again;
1100         assert(m);
1101
1102         /* Drops all unnecessary jobs that reverse already active jobs
1103          * or that stop a running service. */
1104
1105         do {
1106                 Job *j;
1107                 Iterator i;
1108
1109                 again = false;
1110
1111                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1112                         LIST_FOREACH(transaction, j, j) {
1113                                 bool stops_running_service, changes_existing_job;
1114
1115                                 /* If it matters, we shouldn't drop it */
1116                                 if (j->matters_to_anchor)
1117                                         continue;
1118
1119                                 /* Would this stop a running service?
1120                                  * Would this change an existing job?
1121                                  * If so, let's drop this entry */
1122
1123                                 stops_running_service =
1124                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
1125
1126                                 changes_existing_job =
1127                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->type);
1128
1129                                 if (!stops_running_service && !changes_existing_job)
1130                                         continue;
1131
1132                                 if (stops_running_service)
1133                                         log_info("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
1134
1135                                 if (changes_existing_job)
1136                                         log_info("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
1137
1138                                 /* Ok, let's get rid of this */
1139                                 log_info("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
1140
1141                                 transaction_delete_job(m, j, true);
1142                                 again = true;
1143                                 break;
1144                         }
1145
1146                         if (again)
1147                                 break;
1148                 }
1149
1150         } while (again);
1151 }
1152
1153 static int transaction_apply(Manager *m) {
1154         Iterator i;
1155         Job *j;
1156         int r;
1157
1158         /* Moves the transaction jobs to the set of active jobs */
1159
1160         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1161                 /* Assume merged */
1162                 assert(!j->transaction_prev);
1163                 assert(!j->transaction_next);
1164
1165                 if (j->installed)
1166                         continue;
1167
1168                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1169                         goto rollback;
1170         }
1171
1172         while ((j = hashmap_steal_first(m->transaction_jobs))) {
1173                 if (j->installed)
1174                         continue;
1175
1176                 if (j->unit->meta.job)
1177                         job_free(j->unit->meta.job);
1178
1179                 j->unit->meta.job = j;
1180                 j->installed = true;
1181
1182                 /* We're fully installed. Now let's free data we don't
1183                  * need anymore. */
1184
1185                 assert(!j->transaction_next);
1186                 assert(!j->transaction_prev);
1187
1188                 job_add_to_run_queue(j);
1189                 job_add_to_dbus_queue(j);
1190                 job_start_timer(j);
1191         }
1192
1193         /* As last step, kill all remaining job dependencies. */
1194         transaction_clean_dependencies(m);
1195
1196         return 0;
1197
1198 rollback:
1199
1200         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1201                 if (j->installed)
1202                         continue;
1203
1204                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1205         }
1206
1207         return r;
1208 }
1209
1210 static int transaction_activate(Manager *m, JobMode mode, DBusError *e) {
1211         int r;
1212         unsigned generation = 1;
1213
1214         assert(m);
1215
1216         /* This applies the changes recorded in transaction_jobs to
1217          * the actual list of jobs, if possible. */
1218
1219         /* First step: figure out which jobs matter */
1220         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1221
1222         /* Second step: Try not to stop any running services if
1223          * we don't have to. Don't try to reverse running
1224          * jobs if we don't have to. */
1225         transaction_minimize_impact(m);
1226
1227         /* Third step: Drop redundant jobs */
1228         transaction_drop_redundant(m);
1229
1230         for (;;) {
1231                 /* Fourth step: Let's remove unneeded jobs that might
1232                  * be lurking. */
1233                 transaction_collect_garbage(m);
1234
1235                 /* Fifth step: verify order makes sense and correct
1236                  * cycles if necessary and possible */
1237                 if ((r = transaction_verify_order(m, &generation, e)) >= 0)
1238                         break;
1239
1240                 if (r != -EAGAIN) {
1241                         log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r));
1242                         goto rollback;
1243                 }
1244
1245                 /* Let's see if the resulting transaction ordering
1246                  * graph is still cyclic... */
1247         }
1248
1249         for (;;) {
1250                 /* Sixth step: let's drop unmergeable entries if
1251                  * necessary and possible, merge entries we can
1252                  * merge */
1253                 if ((r = transaction_merge_jobs(m, e)) >= 0)
1254                         break;
1255
1256                 if (r != -EAGAIN) {
1257                         log_warning("Requested transaction contains unmergable jobs: %s", bus_error(e, r));
1258                         goto rollback;
1259                 }
1260
1261                 /* Seventh step: an entry got dropped, let's garbage
1262                  * collect its dependencies. */
1263                 transaction_collect_garbage(m);
1264
1265                 /* Let's see if the resulting transaction still has
1266                  * unmergeable entries ... */
1267         }
1268
1269         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1270         transaction_drop_redundant(m);
1271
1272         /* Ninth step: check whether we can actually apply this */
1273         if (mode == JOB_FAIL)
1274                 if ((r = transaction_is_destructive(m, e)) < 0) {
1275                         log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r));
1276                         goto rollback;
1277                 }
1278
1279         /* Tenth step: apply changes */
1280         if ((r = transaction_apply(m)) < 0) {
1281                 log_warning("Failed to apply transaction: %s", strerror(-r));
1282                 goto rollback;
1283         }
1284
1285         assert(hashmap_isempty(m->transaction_jobs));
1286         assert(!m->transaction_anchor);
1287
1288         return 0;
1289
1290 rollback:
1291         transaction_abort(m);
1292         return r;
1293 }
1294
1295 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1296         Job *j, *f;
1297
1298         assert(m);
1299         assert(unit);
1300
1301         /* Looks for an axisting prospective job and returns that. If
1302          * it doesn't exist it is created and added to the prospective
1303          * jobs list. */
1304
1305         f = hashmap_get(m->transaction_jobs, unit);
1306
1307         LIST_FOREACH(transaction, j, f) {
1308                 assert(j->unit == unit);
1309
1310                 if (j->type == type) {
1311                         if (is_new)
1312                                 *is_new = false;
1313                         return j;
1314                 }
1315         }
1316
1317         if (unit->meta.job && unit->meta.job->type == type)
1318                 j = unit->meta.job;
1319         else if (!(j = job_new(m, type, unit)))
1320                 return NULL;
1321
1322         j->generation = 0;
1323         j->marker = NULL;
1324         j->matters_to_anchor = false;
1325         j->override = override;
1326
1327         LIST_PREPEND(Job, transaction, f, j);
1328
1329         if (hashmap_replace(m->transaction_jobs, unit, f) < 0) {
1330                 job_free(j);
1331                 return NULL;
1332         }
1333
1334         if (is_new)
1335                 *is_new = true;
1336
1337         log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1338
1339         return j;
1340 }
1341
1342 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1343         assert(m);
1344         assert(j);
1345
1346         if (j->transaction_prev)
1347                 j->transaction_prev->transaction_next = j->transaction_next;
1348         else if (j->transaction_next)
1349                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1350         else
1351                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1352
1353         if (j->transaction_next)
1354                 j->transaction_next->transaction_prev = j->transaction_prev;
1355
1356         j->transaction_prev = j->transaction_next = NULL;
1357
1358         while (j->subject_list)
1359                 job_dependency_free(j->subject_list);
1360
1361         while (j->object_list) {
1362                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1363
1364                 job_dependency_free(j->object_list);
1365
1366                 if (other && delete_dependencies) {
1367                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
1368                                   other->unit->meta.id, job_type_to_string(other->type),
1369                                   j->unit->meta.id, job_type_to_string(j->type));
1370                         transaction_delete_job(m, other, delete_dependencies);
1371                 }
1372         }
1373 }
1374
1375 static int transaction_add_job_and_dependencies(
1376                 Manager *m,
1377                 JobType type,
1378                 Unit *unit,
1379                 Job *by,
1380                 bool matters,
1381                 bool override,
1382                 bool conflicts,
1383                 DBusError *e,
1384                 Job **_ret) {
1385         Job *ret;
1386         Iterator i;
1387         Unit *dep;
1388         int r;
1389         bool is_new;
1390
1391         assert(m);
1392         assert(type < _JOB_TYPE_MAX);
1393         assert(unit);
1394
1395         if (unit->meta.load_state != UNIT_LOADED && unit->meta.load_state != UNIT_FAILED) {
1396                 dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->meta.id);
1397                 return -EINVAL;
1398         }
1399
1400         if (type != JOB_STOP && unit->meta.load_state == UNIT_FAILED) {
1401                 dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s failed to load: %s. You might find more information in the logs.",
1402                                unit->meta.id,
1403                                strerror(-unit->meta.load_error));
1404                 return -EINVAL;
1405         }
1406
1407         if (!unit_job_is_applicable(unit, type)) {
1408                 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);
1409                 return -EBADR;
1410         }
1411
1412         /* First add the job. */
1413         if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
1414                 return -ENOMEM;
1415
1416         /* Then, add a link to the job. */
1417         if (!job_dependency_new(by, ret, matters, conflicts))
1418                 return -ENOMEM;
1419
1420         if (is_new) {
1421                 /* Finally, recursively add in all dependencies. */
1422                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1423                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1424                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1425                                         goto fail;
1426
1427                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
1428                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, false, e, NULL)) < 0 && r != -EBADR) {
1429                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1430                                         dbus_error_free(e);
1431                                 }
1432
1433                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1434                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, false, e, NULL)) < 0) {
1435                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1436                                         dbus_error_free(e);
1437                                 }
1438
1439                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1440                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1441                                         goto fail;
1442
1443                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1444                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, e, NULL)) < 0 && r != -EBADR) {
1445                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1446                                         dbus_error_free(e);
1447                                 }
1448
1449                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1450                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, true, e, NULL)) < 0 && r != -EBADR)
1451                                         goto fail;
1452
1453                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTED_BY], i)
1454                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1455                                         goto fail;
1456
1457                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1458
1459                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1460                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1461                                         goto fail;
1462                 }
1463
1464                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1465         }
1466
1467         if (_ret)
1468                 *_ret = ret;
1469
1470         return 0;
1471
1472 fail:
1473         return r;
1474 }
1475
1476 static int transaction_add_isolate_jobs(Manager *m) {
1477         Iterator i;
1478         Unit *u;
1479         char *k;
1480         int r;
1481
1482         assert(m);
1483
1484         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
1485
1486                 /* ignore aliases */
1487                 if (u->meta.id != k)
1488                         continue;
1489
1490                 if (UNIT_VTABLE(u)->no_isolate)
1491                         continue;
1492
1493                 /* No need to stop inactive jobs */
1494                 if (UNIT_IS_INACTIVE_OR_MAINTENANCE(unit_active_state(u)))
1495                         continue;
1496
1497                 /* Is there already something listed for this? */
1498                 if (hashmap_get(m->transaction_jobs, u))
1499                         continue;
1500
1501                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, false, NULL, NULL)) < 0)
1502                         log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
1503         }
1504
1505         return 0;
1506 }
1507
1508 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, DBusError *e, Job **_ret) {
1509         int r;
1510         Job *ret;
1511
1512         assert(m);
1513         assert(type < _JOB_TYPE_MAX);
1514         assert(unit);
1515         assert(mode < _JOB_MODE_MAX);
1516
1517         if (mode == JOB_ISOLATE && type != JOB_START) {
1518                 dbus_set_error(e, BUS_ERROR_INVALID_JOB_MODE, "Isolate is only valid for start.");
1519                 return -EINVAL;
1520         }
1521
1522         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1523
1524         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, false, e, &ret)) < 0) {
1525                 transaction_abort(m);
1526                 return r;
1527         }
1528
1529         if (mode == JOB_ISOLATE)
1530                 if ((r = transaction_add_isolate_jobs(m)) < 0) {
1531                         transaction_abort(m);
1532                         return r;
1533                 }
1534
1535         if ((r = transaction_activate(m, mode, e)) < 0)
1536                 return r;
1537
1538         log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1539
1540         if (_ret)
1541                 *_ret = ret;
1542
1543         return 0;
1544 }
1545
1546 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, DBusError *e, Job **_ret) {
1547         Unit *unit;
1548         int r;
1549
1550         assert(m);
1551         assert(type < _JOB_TYPE_MAX);
1552         assert(name);
1553         assert(mode < _JOB_MODE_MAX);
1554
1555         if ((r = manager_load_unit(m, name, NULL, NULL, &unit)) < 0)
1556                 return r;
1557
1558         return manager_add_job(m, type, unit, mode, override, e, _ret);
1559 }
1560
1561 Job *manager_get_job(Manager *m, uint32_t id) {
1562         assert(m);
1563
1564         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1565 }
1566
1567 Unit *manager_get_unit(Manager *m, const char *name) {
1568         assert(m);
1569         assert(name);
1570
1571         return hashmap_get(m->units, name);
1572 }
1573
1574 unsigned manager_dispatch_load_queue(Manager *m) {
1575         Meta *meta;
1576         unsigned n = 0;
1577
1578         assert(m);
1579
1580         /* Make sure we are not run recursively */
1581         if (m->dispatching_load_queue)
1582                 return 0;
1583
1584         m->dispatching_load_queue = true;
1585
1586         /* Dispatches the load queue. Takes a unit from the queue and
1587          * tries to load its data until the queue is empty */
1588
1589         while ((meta = m->load_queue)) {
1590                 assert(meta->in_load_queue);
1591
1592                 unit_load((Unit*) meta);
1593                 n++;
1594         }
1595
1596         m->dispatching_load_queue = false;
1597         return n;
1598 }
1599
1600 int manager_load_unit_prepare(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1601         Unit *ret;
1602         int r;
1603
1604         assert(m);
1605         assert(name || path);
1606
1607         /* This will prepare the unit for loading, but not actually
1608          * load anything from disk. */
1609
1610         if (path && !is_path(path)) {
1611                 dbus_set_error(e, BUS_ERROR_INVALID_PATH, "Path %s is not absolute.", path);
1612                 return -EINVAL;
1613         }
1614
1615         if (!name)
1616                 name = file_name_from_path(path);
1617
1618         if (!unit_name_is_valid(name)) {
1619                 dbus_set_error(e, BUS_ERROR_INVALID_NAME, "Unit name %s is not valid.", name);
1620                 return -EINVAL;
1621         }
1622
1623         if ((ret = manager_get_unit(m, name))) {
1624                 *_ret = ret;
1625                 return 1;
1626         }
1627
1628         if (!(ret = unit_new(m)))
1629                 return -ENOMEM;
1630
1631         if (path)
1632                 if (!(ret->meta.fragment_path = strdup(path))) {
1633                         unit_free(ret);
1634                         return -ENOMEM;
1635                 }
1636
1637         if ((r = unit_add_name(ret, name)) < 0) {
1638                 unit_free(ret);
1639                 return r;
1640         }
1641
1642         unit_add_to_load_queue(ret);
1643         unit_add_to_dbus_queue(ret);
1644         unit_add_to_gc_queue(ret);
1645
1646         if (_ret)
1647                 *_ret = ret;
1648
1649         return 0;
1650 }
1651
1652 int manager_load_unit(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1653         int r;
1654
1655         assert(m);
1656
1657         /* This will load the service information files, but not actually
1658          * start any services or anything. */
1659
1660         if ((r = manager_load_unit_prepare(m, name, path, e, _ret)) != 0)
1661                 return r;
1662
1663         manager_dispatch_load_queue(m);
1664
1665         if (_ret)
1666                 *_ret = unit_follow_merge(*_ret);
1667
1668         return 0;
1669 }
1670
1671 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1672         Iterator i;
1673         Job *j;
1674
1675         assert(s);
1676         assert(f);
1677
1678         HASHMAP_FOREACH(j, s->jobs, i)
1679                 job_dump(j, f, prefix);
1680 }
1681
1682 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1683         Iterator i;
1684         Unit *u;
1685         const char *t;
1686
1687         assert(s);
1688         assert(f);
1689
1690         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1691                 if (u->meta.id == t)
1692                         unit_dump(u, f, prefix);
1693 }
1694
1695 void manager_clear_jobs(Manager *m) {
1696         Job *j;
1697
1698         assert(m);
1699
1700         transaction_abort(m);
1701
1702         while ((j = hashmap_first(m->jobs)))
1703                 job_free(j);
1704 }
1705
1706 unsigned manager_dispatch_run_queue(Manager *m) {
1707         Job *j;
1708         unsigned n = 0;
1709
1710         if (m->dispatching_run_queue)
1711                 return 0;
1712
1713         m->dispatching_run_queue = true;
1714
1715         while ((j = m->run_queue)) {
1716                 assert(j->installed);
1717                 assert(j->in_run_queue);
1718
1719                 job_run_and_invalidate(j);
1720                 n++;
1721         }
1722
1723         m->dispatching_run_queue = false;
1724         return n;
1725 }
1726
1727 unsigned manager_dispatch_dbus_queue(Manager *m) {
1728         Job *j;
1729         Meta *meta;
1730         unsigned n = 0;
1731
1732         assert(m);
1733
1734         if (m->dispatching_dbus_queue)
1735                 return 0;
1736
1737         m->dispatching_dbus_queue = true;
1738
1739         while ((meta = m->dbus_unit_queue)) {
1740                 assert(meta->in_dbus_queue);
1741
1742                 bus_unit_send_change_signal((Unit*) meta);
1743                 n++;
1744         }
1745
1746         while ((j = m->dbus_job_queue)) {
1747                 assert(j->in_dbus_queue);
1748
1749                 bus_job_send_change_signal(j);
1750                 n++;
1751         }
1752
1753         m->dispatching_dbus_queue = false;
1754         return n;
1755 }
1756
1757 static int manager_process_notify_fd(Manager *m) {
1758         ssize_t n;
1759
1760         assert(m);
1761
1762         for (;;) {
1763                 char buf[4096];
1764                 struct msghdr msghdr;
1765                 struct iovec iovec;
1766                 struct ucred *ucred;
1767                 union {
1768                         struct cmsghdr cmsghdr;
1769                         uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
1770                 } control;
1771                 Unit *u;
1772                 char **tags;
1773
1774                 zero(iovec);
1775                 iovec.iov_base = buf;
1776                 iovec.iov_len = sizeof(buf)-1;
1777
1778                 zero(control);
1779                 zero(msghdr);
1780                 msghdr.msg_iov = &iovec;
1781                 msghdr.msg_iovlen = 1;
1782                 msghdr.msg_control = &control;
1783                 msghdr.msg_controllen = sizeof(control);
1784
1785                 if ((n = recvmsg(m->notify_watch.fd, &msghdr, MSG_DONTWAIT)) <= 0) {
1786                         if (n >= 0)
1787                                 return -EIO;
1788
1789                         if (errno == EAGAIN)
1790                                 break;
1791
1792                         return -errno;
1793                 }
1794
1795                 if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
1796                     control.cmsghdr.cmsg_level != SOL_SOCKET ||
1797                     control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
1798                     control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
1799                         log_warning("Received notify message without credentials. Ignoring.");
1800                         continue;
1801                 }
1802
1803                 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
1804
1805                 if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(ucred->pid))))
1806                         if (!(u = cgroup_unit_by_pid(m, ucred->pid))) {
1807                                 log_warning("Cannot find unit for notify message of PID %lu.", (unsigned long) ucred->pid);
1808                                 continue;
1809                         }
1810
1811                 assert((size_t) n < sizeof(buf));
1812                 buf[n] = 0;
1813                 if (!(tags = strv_split(buf, "\n\r")))
1814                         return -ENOMEM;
1815
1816                 log_debug("Got notification message for unit %s", u->meta.id);
1817
1818                 if (UNIT_VTABLE(u)->notify_message)
1819                         UNIT_VTABLE(u)->notify_message(u, ucred->pid, tags);
1820
1821                 strv_free(tags);
1822         }
1823
1824         return 0;
1825 }
1826
1827 static int manager_dispatch_sigchld(Manager *m) {
1828         assert(m);
1829
1830         for (;;) {
1831                 siginfo_t si;
1832                 Unit *u;
1833                 int r;
1834
1835                 zero(si);
1836
1837                 /* First we call waitd() for a PID and do not reap the
1838                  * zombie. That way we can still access /proc/$PID for
1839                  * it while it is a zombie. */
1840                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1841
1842                         if (errno == ECHILD)
1843                                 break;
1844
1845                         if (errno == EINTR)
1846                                 continue;
1847
1848                         return -errno;
1849                 }
1850
1851                 if (si.si_pid <= 0)
1852                         break;
1853
1854                 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1855                         char *name = NULL;
1856
1857                         get_process_name(si.si_pid, &name);
1858                         log_debug("Got SIGCHLD for process %lu (%s)", (unsigned long) si.si_pid, strna(name));
1859                         free(name);
1860                 }
1861
1862                 /* Let's flush any message the dying child might still
1863                  * have queued for us. This ensures that the process
1864                  * still exists in /proc so that we can figure out
1865                  * which cgroup and hence unit it belongs to. */
1866                 if ((r = manager_process_notify_fd(m)) < 0)
1867                         return r;
1868
1869                 /* And now figure out the unit this belongs to */
1870                 if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(si.si_pid))))
1871                         u = cgroup_unit_by_pid(m, si.si_pid);
1872
1873                 /* And now, we actually reap the zombie. */
1874                 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1875                         if (errno == EINTR)
1876                                 continue;
1877
1878                         return -errno;
1879                 }
1880
1881                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1882                         continue;
1883
1884                 log_debug("Child %lu died (code=%s, status=%i/%s)",
1885                           (long unsigned) si.si_pid,
1886                           sigchld_code_to_string(si.si_code),
1887                           si.si_status,
1888                           strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : signal_to_string(si.si_status)));
1889
1890                 if (!u)
1891                         continue;
1892
1893                 log_debug("Child %lu belongs to %s", (long unsigned) si.si_pid, u->meta.id);
1894
1895                 hashmap_remove(m->watch_pids, LONG_TO_PTR(si.si_pid));
1896                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1897         }
1898
1899         return 0;
1900 }
1901
1902 static int manager_start_target(Manager *m, const char *name, JobMode mode) {
1903         int r;
1904         DBusError error;
1905
1906         dbus_error_init(&error);
1907
1908         log_info("Activating special unit %s", name);
1909
1910         if ((r = manager_add_job_by_name(m, JOB_START, name, mode, true, &error, NULL)) < 0)
1911                 log_error("Failed to enqueue %s job: %s", name, bus_error(&error, r));
1912
1913         dbus_error_free(&error);
1914
1915         return r;
1916 }
1917
1918 static int manager_process_signal_fd(Manager *m) {
1919         ssize_t n;
1920         struct signalfd_siginfo sfsi;
1921         bool sigchld = false;
1922
1923         assert(m);
1924
1925         for (;;) {
1926                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1927
1928                         if (n >= 0)
1929                                 return -EIO;
1930
1931                         if (errno == EAGAIN)
1932                                 break;
1933
1934                         return -errno;
1935                 }
1936
1937                 log_debug("Received SIG%s", strna(signal_to_string(sfsi.ssi_signo)));
1938
1939                 switch (sfsi.ssi_signo) {
1940
1941                 case SIGCHLD:
1942                         sigchld = true;
1943                         break;
1944
1945                 case SIGTERM:
1946                         if (m->running_as == MANAGER_SYSTEM) {
1947                                 /* This is for compatibility with the
1948                                  * original sysvinit */
1949                                 m->exit_code = MANAGER_REEXECUTE;
1950                                 break;
1951                         }
1952
1953                         /* Fall through */
1954
1955                 case SIGINT:
1956                         if (m->running_as == MANAGER_SYSTEM) {
1957                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET, JOB_REPLACE);
1958                                 break;
1959                         }
1960
1961                         /* Run the exit target if there is one, if not, just exit. */
1962                         if (manager_start_target(m, SPECIAL_EXIT_SERVICE, JOB_REPLACE) < 0) {
1963                                 m->exit_code = MANAGER_EXIT;
1964                                 return 0;
1965                         }
1966
1967                         break;
1968
1969                 case SIGWINCH:
1970                         if (m->running_as == MANAGER_SYSTEM)
1971                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET, JOB_REPLACE);
1972
1973                         /* This is a nop on non-init */
1974                         break;
1975
1976                 case SIGPWR:
1977                         if (m->running_as == MANAGER_SYSTEM)
1978                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET, JOB_REPLACE);
1979
1980                         /* This is a nop on non-init */
1981                         break;
1982
1983                 case SIGUSR1: {
1984                         Unit *u;
1985
1986                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1987
1988                         if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
1989                                 log_info("Trying to reconnect to bus...");
1990                                 bus_init(m);
1991                         }
1992
1993                         if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
1994                                 log_info("Loading D-Bus service...");
1995                                 manager_start_target(m, SPECIAL_DBUS_SERVICE, JOB_REPLACE);
1996                         }
1997
1998                         break;
1999                 }
2000
2001                 case SIGUSR2: {
2002                         FILE *f;
2003                         char *dump = NULL;
2004                         size_t size;
2005
2006                         if (!(f = open_memstream(&dump, &size))) {
2007                                 log_warning("Failed to allocate memory stream.");
2008                                 break;
2009                         }
2010
2011                         manager_dump_units(m, f, "\t");
2012                         manager_dump_jobs(m, f, "\t");
2013
2014                         if (ferror(f)) {
2015                                 fclose(f);
2016                                 free(dump);
2017                                 log_warning("Failed to write status stream");
2018                                 break;
2019                         }
2020
2021                         fclose(f);
2022                         log_dump(LOG_INFO, dump);
2023                         free(dump);
2024
2025                         break;
2026                 }
2027
2028                 case SIGHUP:
2029                         m->exit_code = MANAGER_RELOAD;
2030                         break;
2031
2032                 default: {
2033                         static const char * const table[] = {
2034                                 [0] = SPECIAL_DEFAULT_TARGET,
2035                                 [1] = SPECIAL_RESCUE_TARGET,
2036                                 [2] = SPECIAL_EMERGENCY_TARGET,
2037                                 [3] = SPECIAL_HALT_TARGET,
2038                                 [4] = SPECIAL_POWEROFF_TARGET,
2039                                 [5] = SPECIAL_REBOOT_TARGET
2040                         };
2041
2042                         if ((int) sfsi.ssi_signo >= SIGRTMIN+0 &&
2043                             (int) sfsi.ssi_signo < SIGRTMIN+(int) ELEMENTSOF(table)) {
2044                                 manager_start_target(m, table[sfsi.ssi_signo - SIGRTMIN],
2045                                                      (sfsi.ssi_signo == 1 || sfsi.ssi_signo == 2) ? JOB_ISOLATE : JOB_REPLACE);
2046                                 break;
2047                         }
2048
2049                         log_warning("Got unhandled signal <%s>.", strna(signal_to_string(sfsi.ssi_signo)));
2050                 }
2051                 }
2052         }
2053
2054         if (sigchld)
2055                 return manager_dispatch_sigchld(m);
2056
2057         return 0;
2058 }
2059
2060 static int process_event(Manager *m, struct epoll_event *ev) {
2061         int r;
2062         Watch *w;
2063
2064         assert(m);
2065         assert(ev);
2066
2067         assert(w = ev->data.ptr);
2068
2069         switch (w->type) {
2070
2071         case WATCH_SIGNAL:
2072
2073                 /* An incoming signal? */
2074                 if (ev->events != EPOLLIN)
2075                         return -EINVAL;
2076
2077                 if ((r = manager_process_signal_fd(m)) < 0)
2078                         return r;
2079
2080                 break;
2081
2082         case WATCH_NOTIFY:
2083
2084                 /* An incoming daemon notification event? */
2085                 if (ev->events != EPOLLIN)
2086                         return -EINVAL;
2087
2088                 if ((r = manager_process_notify_fd(m)) < 0)
2089                         return r;
2090
2091                 break;
2092
2093         case WATCH_FD:
2094
2095                 /* Some fd event, to be dispatched to the units */
2096                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
2097                 break;
2098
2099         case WATCH_UNIT_TIMER:
2100         case WATCH_JOB_TIMER: {
2101                 uint64_t v;
2102                 ssize_t k;
2103
2104                 /* Some timer event, to be dispatched to the units */
2105                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
2106
2107                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
2108                                 break;
2109
2110                         return k < 0 ? -errno : -EIO;
2111                 }
2112
2113                 if (w->type == WATCH_UNIT_TIMER)
2114                         UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
2115                 else
2116                         job_timer_event(w->data.job, v, w);
2117                 break;
2118         }
2119
2120         case WATCH_MOUNT:
2121                 /* Some mount table change, intended for the mount subsystem */
2122                 mount_fd_event(m, ev->events);
2123                 break;
2124
2125         case WATCH_UDEV:
2126                 /* Some notification from udev, intended for the device subsystem */
2127                 device_fd_event(m, ev->events);
2128                 break;
2129
2130         case WATCH_DBUS_WATCH:
2131                 bus_watch_event(m, w, ev->events);
2132                 break;
2133
2134         case WATCH_DBUS_TIMEOUT:
2135                 bus_timeout_event(m, w, ev->events);
2136                 break;
2137
2138         default:
2139                 assert_not_reached("Unknown epoll event type.");
2140         }
2141
2142         return 0;
2143 }
2144
2145 int manager_loop(Manager *m) {
2146         int r;
2147
2148         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
2149
2150         assert(m);
2151         m->exit_code = MANAGER_RUNNING;
2152
2153         /* Release the path cache */
2154         set_free_free(m->unit_path_cache);
2155         m->unit_path_cache = NULL;
2156
2157         /* There might still be some zombies hanging around from
2158          * before we were exec()'ed. Leat's reap them */
2159         if ((r = manager_dispatch_sigchld(m)) < 0)
2160                 return r;
2161
2162         while (m->exit_code == MANAGER_RUNNING) {
2163                 struct epoll_event event;
2164                 int n;
2165
2166                 if (!ratelimit_test(&rl)) {
2167                         /* Yay, something is going seriously wrong, pause a little */
2168                         log_warning("Looping too fast. Throttling execution a little.");
2169                         sleep(1);
2170                 }
2171
2172                 if (manager_dispatch_load_queue(m) > 0)
2173                         continue;
2174
2175                 if (manager_dispatch_run_queue(m) > 0)
2176                         continue;
2177
2178                 if (bus_dispatch(m) > 0)
2179                         continue;
2180
2181                 if (manager_dispatch_cleanup_queue(m) > 0)
2182                         continue;
2183
2184                 if (manager_dispatch_gc_queue(m) > 0)
2185                         continue;
2186
2187                 if (manager_dispatch_dbus_queue(m) > 0)
2188                         continue;
2189
2190                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
2191
2192                         if (errno == EINTR)
2193                                 continue;
2194
2195                         return -errno;
2196                 }
2197
2198                 assert(n == 1);
2199
2200                 if ((r = process_event(m, &event)) < 0)
2201                         return r;
2202         }
2203
2204         return m->exit_code;
2205 }
2206
2207 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
2208         char *n;
2209         Unit *u;
2210
2211         assert(m);
2212         assert(s);
2213         assert(_u);
2214
2215         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
2216                 return -EINVAL;
2217
2218         if (!(n = bus_path_unescape(s+31)))
2219                 return -ENOMEM;
2220
2221         u = manager_get_unit(m, n);
2222         free(n);
2223
2224         if (!u)
2225                 return -ENOENT;
2226
2227         *_u = u;
2228
2229         return 0;
2230 }
2231
2232 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
2233         Job *j;
2234         unsigned id;
2235         int r;
2236
2237         assert(m);
2238         assert(s);
2239         assert(_j);
2240
2241         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
2242                 return -EINVAL;
2243
2244         if ((r = safe_atou(s + 30, &id)) < 0)
2245                 return r;
2246
2247         if (!(j = manager_get_job(m, id)))
2248                 return -ENOENT;
2249
2250         *_j = j;
2251
2252         return 0;
2253 }
2254
2255 void manager_send_unit_audit(Manager *m, Unit *u, int type, bool success) {
2256
2257 #ifdef HAVE_AUDIT
2258         char *p;
2259
2260         if (m->audit_fd < 0)
2261                 return;
2262
2263         /* Don't generate audit events if the service was already
2264          * started and we're just deserializing */
2265         if (m->n_deserializing > 0)
2266                 return;
2267
2268         if (!(p = unit_name_to_prefix_and_instance(u->meta.id))) {
2269                 log_error("Failed to allocate unit name for audit message: %s", strerror(ENOMEM));
2270                 return;
2271         }
2272
2273         if (audit_log_user_comm_message(m->audit_fd, type, "", p, NULL, NULL, NULL, success) < 0)
2274                 log_error("Failed to send audit message: %m");
2275
2276         free(p);
2277 #endif
2278
2279 }
2280
2281 void manager_dispatch_bus_name_owner_changed(
2282                 Manager *m,
2283                 const char *name,
2284                 const char* old_owner,
2285                 const char *new_owner) {
2286
2287         Unit *u;
2288
2289         assert(m);
2290         assert(name);
2291
2292         if (!(u = hashmap_get(m->watch_bus, name)))
2293                 return;
2294
2295         UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
2296 }
2297
2298 void manager_dispatch_bus_query_pid_done(
2299                 Manager *m,
2300                 const char *name,
2301                 pid_t pid) {
2302
2303         Unit *u;
2304
2305         assert(m);
2306         assert(name);
2307         assert(pid >= 1);
2308
2309         if (!(u = hashmap_get(m->watch_bus, name)))
2310                 return;
2311
2312         UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
2313 }
2314
2315 int manager_open_serialization(Manager *m, FILE **_f) {
2316         char *path;
2317         mode_t saved_umask;
2318         int fd;
2319         FILE *f;
2320
2321         assert(_f);
2322
2323         if (m->running_as == MANAGER_SYSTEM) {
2324                 mkdir_p("/dev/.systemd", 0755);
2325
2326                 if (asprintf(&path, "/dev/.systemd/dump-%lu-XXXXXX", (unsigned long) getpid()) < 0)
2327                         return -ENOMEM;
2328         } else {
2329                 if (asprintf(&path, "/tmp/systemd-dump-%lu-XXXXXX", (unsigned long) getpid()) < 0)
2330                         return -ENOMEM;
2331         }
2332
2333         saved_umask = umask(0077);
2334         fd = mkostemp(path, O_RDWR|O_CLOEXEC);
2335         umask(saved_umask);
2336
2337         if (fd < 0) {
2338                 free(path);
2339                 return -errno;
2340         }
2341
2342         unlink(path);
2343
2344         log_debug("Serializing state to %s", path);
2345         free(path);
2346
2347         if (!(f = fdopen(fd, "w+")) < 0)
2348                 return -errno;
2349
2350         *_f = f;
2351
2352         return 0;
2353 }
2354
2355 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
2356         Iterator i;
2357         Unit *u;
2358         const char *t;
2359         int r;
2360
2361         assert(m);
2362         assert(f);
2363         assert(fds);
2364
2365         fprintf(f, "startup-timestamp=%llu %llu\n\n",
2366                 (unsigned long long) m->startup_timestamp.realtime,
2367                 (unsigned long long) m->startup_timestamp.monotonic);
2368
2369         HASHMAP_FOREACH_KEY(u, t, m->units, i) {
2370                 if (u->meta.id != t)
2371                         continue;
2372
2373                 if (!unit_can_serialize(u))
2374                         continue;
2375
2376                 /* Start marker */
2377                 fputs(u->meta.id, f);
2378                 fputc('\n', f);
2379
2380                 if ((r = unit_serialize(u, f, fds)) < 0)
2381                         return r;
2382         }
2383
2384         if (ferror(f))
2385                 return -EIO;
2386
2387         return 0;
2388 }
2389
2390 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2391         int r = 0;
2392
2393         assert(m);
2394         assert(f);
2395
2396         log_debug("Deserializing state...");
2397
2398         m->n_deserializing ++;
2399
2400         for (;;) {
2401                 char line[1024], *l;
2402
2403                 if (!fgets(line, sizeof(line), f)) {
2404                         if (feof(f))
2405                                 r = 0;
2406                         else
2407                                 r = -errno;
2408
2409                         goto finish;
2410                 }
2411
2412                 char_array_0(line);
2413                 l = strstrip(line);
2414
2415                 if (l[0] == 0)
2416                         break;
2417
2418                 if (startswith(l, "startup-timestamp=")) {
2419                         unsigned long long a, b;
2420
2421                         if (sscanf(l+18, "%lli %llu", &a, &b) != 2)
2422                                 log_debug("Failed to parse startup timestamp value %s", l+18);
2423                         else {
2424                                 m->startup_timestamp.realtime = a;
2425                                 m->startup_timestamp.monotonic = b;
2426                         }
2427                 } else
2428                         log_debug("Unknown serialization item '%s'", l);
2429         }
2430
2431         for (;;) {
2432                 Unit *u;
2433                 char name[UNIT_NAME_MAX+2];
2434
2435                 /* Start marker */
2436                 if (!fgets(name, sizeof(name), f)) {
2437                         if (feof(f))
2438                                 r = 0;
2439                         else
2440                                 r = -errno;
2441
2442                         goto finish;
2443                 }
2444
2445                 char_array_0(name);
2446
2447                 if ((r = manager_load_unit(m, strstrip(name), NULL, NULL, &u)) < 0)
2448                         goto finish;
2449
2450                 if ((r = unit_deserialize(u, f, fds)) < 0)
2451                         goto finish;
2452         }
2453
2454 finish:
2455         if (ferror(f)) {
2456                 r = -EIO;
2457                 goto finish;
2458         }
2459
2460         assert(m->n_deserializing > 0);
2461         m->n_deserializing --;
2462
2463         return r;
2464 }
2465
2466 int manager_reload(Manager *m) {
2467         int r, q;
2468         FILE *f;
2469         FDSet *fds;
2470
2471         assert(m);
2472
2473         if ((r = manager_open_serialization(m, &f)) < 0)
2474                 return r;
2475
2476         if (!(fds = fdset_new())) {
2477                 r = -ENOMEM;
2478                 goto finish;
2479         }
2480
2481         if ((r = manager_serialize(m, f, fds)) < 0)
2482                 goto finish;
2483
2484         if (fseeko(f, 0, SEEK_SET) < 0) {
2485                 r = -errno;
2486                 goto finish;
2487         }
2488
2489         /* From here on there is no way back. */
2490         manager_clear_jobs_and_units(m);
2491
2492         /* Find new unit paths */
2493         lookup_paths_free(&m->lookup_paths);
2494         if ((q = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
2495                 r = q;
2496
2497         m->n_deserializing ++;
2498
2499         /* First, enumerate what we can from all config files */
2500         if ((q = manager_enumerate(m)) < 0)
2501                 r = q;
2502
2503         /* Second, deserialize our stored data */
2504         if ((q = manager_deserialize(m, f, fds)) < 0)
2505                 r = q;
2506
2507         fclose(f);
2508         f = NULL;
2509
2510         /* Third, fire things up! */
2511         if ((q = manager_coldplug(m)) < 0)
2512                 r = q;
2513
2514         assert(m->n_deserializing > 0);
2515         m->n_deserializing ++;
2516
2517 finish:
2518         if (f)
2519                 fclose(f);
2520
2521         if (fds)
2522                 fdset_free(fds);
2523
2524         return r;
2525 }
2526
2527 bool manager_is_booting_or_shutting_down(Manager *m) {
2528         Unit *u;
2529
2530         assert(m);
2531
2532         /* Is the initial job still around? */
2533         if (manager_get_job(m, 1))
2534                 return true;
2535
2536         /* Is there a job for the shutdown target? */
2537         if (((u = manager_get_unit(m, SPECIAL_SHUTDOWN_TARGET))))
2538                 return !!u->meta.job;
2539
2540         return false;
2541 }
2542
2543 void manager_reset_maintenance(Manager *m) {
2544         Unit *u;
2545         Iterator i;
2546
2547         assert(m);
2548
2549         HASHMAP_FOREACH(u, m->units, i)
2550                 unit_reset_maintenance(u);
2551 }
2552
2553 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2554         [MANAGER_SYSTEM] = "system",
2555         [MANAGER_SESSION] = "session"
2556 };
2557
2558 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);