src/login/logind-session.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2011 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 <errno.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <sys/epoll.h>
  26 #include <fcntl.h>
  27
  28 #include "logind-session.h"
  29 #include "strv.h"
  30 #include "util.h"
  31 #include "cgroup-util.h"
  32
  33 #define IDLE_THRESHOLD_USEC (5*USEC_PER_MINUTE)
  34
  35 Session* session_new(Manager *m, User *u, const char *id) {
  36         Session *s;
  37
  38         assert(m);
  39         assert(id);
  40
  41         s = new0(Session, 1);
  42         if (!s)
  43                 return NULL;
  44
  45         s->state_file = strappend("/run/systemd/sessions/", id);
  46         if (!s->state_file) {
  47                 free(s);
  48                 return NULL;
  49         }
  50
  51         s->id = file_name_from_path(s->state_file);
  52
  53         if (hashmap_put(m->sessions, s->id, s) < 0) {
  54                 free(s->id);
  55                 free(s);
  56                 return NULL;
  57         }
  58
  59         s->manager = m;
  60         s->fifo_fd = -1;
  61         s->user = u;
  62
  63         LIST_PREPEND(Session, sessions_by_user, u->sessions, s);
  64
  65         return s;
  66 }
  67
  68 void session_free(Session *s) {
  69         assert(s);
  70
  71         if (s->in_gc_queue)
  72                 LIST_REMOVE(Session, gc_queue, s->manager->session_gc_queue, s);
  73
  74         if (s->user) {
  75                 LIST_REMOVE(Session, sessions_by_user, s->user->sessions, s);
  76
  77                 if (s->user->display == s)
  78                         s->user->display = NULL;
  79         }
  80
  81         if (s->seat) {
  82                 if (s->seat->active == s)
  83                         s->seat->active = NULL;
  84
  85                 LIST_REMOVE(Session, sessions_by_seat, s->seat->sessions, s);
  86         }
  87
  88         if (s->cgroup_path)
  89                 hashmap_remove(s->manager->cgroups, s->cgroup_path);
  90
  91         free(s->cgroup_path);
  92         strv_free(s->controllers);
  93
  94         free(s->tty);
  95         free(s->display);
  96         free(s->remote_host);
  97         free(s->remote_user);
  98         free(s->service);
  99
 100         hashmap_remove(s->manager->sessions, s->id);
 101
 102         session_remove_fifo(s);
 103
 104         free(s->state_file);
 105         free(s);
 106 }
 107
 108 int session_save(Session *s) {
 109         FILE *f;
 110         int r = 0;
 111         char *temp_path;
 112
 113         assert(s);
 114
 115         if (!s->started)
 116                 return 0;
 117
 118         r = safe_mkdir("/run/systemd/sessions", 0755, 0, 0);
 119         if (r < 0)
 120                 goto finish;
 121
 122         r = fopen_temporary(s->state_file, &f, &temp_path);
 123         if (r < 0)
 124                 goto finish;
 125
 126         assert(s->user);
 127
 128         fchmod(fileno(f), 0644);
 129
 130         fprintf(f,
 131                 "# This is private data. Do not parse.\n"
 132                 "UID=%lu\n"
 133                 "USER=%s\n"
 134                 "ACTIVE=%i\n"
 135                 "REMOTE=%i\n"
 136                 "KILL_PROCESSES=%i\n",
 137                 (unsigned long) s->user->uid,
 138                 s->user->name,
 139                 session_is_active(s),
 140                 s->remote,
 141                 s->kill_processes);
 142
 143         if (s->type >= 0)
 144                 fprintf(f,
 145                         "TYPE=%s\n",
 146                         session_type_to_string(s->type));
 147
 148         if (s->cgroup_path)
 149                 fprintf(f,
 150                         "CGROUP=%s\n",
 151                         s->cgroup_path);
 152
 153         if (s->fifo_path)
 154                 fprintf(f,
 155                         "FIFO=%s\n",
 156                         s->fifo_path);
 157
 158         if (s->seat)
 159                 fprintf(f,
 160                         "SEAT=%s\n",
 161                         s->seat->id);
 162
 163         if (s->tty)
 164                 fprintf(f,
 165                         "TTY=%s\n",
 166                         s->tty);
 167
 168         if (s->display)
 169                 fprintf(f,
 170                         "DISPLAY=%s\n",
 171                         s->display);
 172
 173         if (s->remote_host)
 174                 fprintf(f,
 175                         "REMOTE_HOST=%s\n",
 176                         s->remote_host);
 177
 178         if (s->remote_user)
 179                 fprintf(f,
 180                         "REMOTE_USER=%s\n",
 181                         s->remote_user);
 182
 183         if (s->service)
 184                 fprintf(f,
 185                         "SERVICE=%s\n",
 186                         s->service);
 187
 188         if (s->seat && seat_can_multi_session(s->seat))
 189                 fprintf(f,
 190                         "VTNR=%i\n",
 191                         s->vtnr);
 192
 193         if (s->leader > 0)
 194                 fprintf(f,
 195                         "LEADER=%lu\n",
 196                         (unsigned long) s->leader);
 197
 198         if (s->audit_id > 0)
 199                 fprintf(f,
 200                         "AUDIT=%llu\n",
 201                         (unsigned long long) s->audit_id);
 202
 203         fflush(f);
 204
 205         if (ferror(f) || rename(temp_path, s->state_file) < 0) {
 206                 r = -errno;
 207                 unlink(s->state_file);
 208                 unlink(temp_path);
 209         }
 210
 211         fclose(f);
 212         free(temp_path);
 213
 214 finish:
 215         if (r < 0)
 216                 log_error("Failed to save session data for %s: %s", s->id, strerror(-r));
 217
 218         return r;
 219 }
 220
 221 int session_load(Session *s) {
 222         char *remote = NULL,
 223                 *kill_processes = NULL,
 224                 *seat = NULL,
 225                 *vtnr = NULL,
 226                 *leader = NULL,
 227                 *audit_id = NULL,
 228                 *type = NULL;
 229
 230         int k, r;
 231
 232         assert(s);
 233
 234         r = parse_env_file(s->state_file, NEWLINE,
 235                            "REMOTE",         &remote,
 236                            "KILL_PROCESSES", &kill_processes,
 237                            "CGROUP",         &s->cgroup_path,
 238                            "FIFO",           &s->fifo_path,
 239                            "SEAT",           &seat,
 240                            "TTY",            &s->tty,
 241                            "DISPLAY",        &s->display,
 242                            "REMOTE_HOST",    &s->remote_host,
 243                            "REMOTE_USER",    &s->remote_user,
 244                            "SERVICE",        &s->service,
 245                            "VTNR",           &vtnr,
 246                            "LEADER",         &leader,
 247                            "TYPE",           &type,
 248                            NULL);
 249
 250         if (r < 0)
 251                 goto finish;
 252
 253         if (remote) {
 254                 k = parse_boolean(remote);
 255                 if (k >= 0)
 256                         s->remote = k;
 257         }
 258
 259         if (kill_processes) {
 260                 k = parse_boolean(kill_processes);
 261                 if (k >= 0)
 262                         s->kill_processes = k;
 263         }
 264
 265         if (seat && !s->seat) {
 266                 Seat *o;
 267
 268                 o = hashmap_get(s->manager->seats, seat);
 269                 if (o)
 270                         seat_attach_session(o, s);
 271         }
 272
 273         if (vtnr && s->seat && seat_can_multi_session(s->seat)) {
 274                 int v;
 275
 276                 k = safe_atoi(vtnr, &v);
 277                 if (k >= 0 && v >= 1)
 278                         s->vtnr = v;
 279         }
 280
 281         if (leader) {
 282                 pid_t pid;
 283
 284                 k = parse_pid(leader, &pid);
 285                 if (k >= 0 && pid >= 1) {
 286                         s->leader = pid;
 287
 288                         audit_session_from_pid(pid, &s->audit_id);
 289                 }
 290         }
 291
 292         if (type) {
 293                 SessionType t;
 294
 295                 t = session_type_from_string(type);
 296                 if (t >= 0)
 297                         s->type = t;
 298         }
 299
 300         if (s->fifo_path) {
 301                 int fd;
 302
 303                 /* If we open an unopened pipe for reading we will not
 304                    get an EOF. to trigger an EOF we hence open it for
 305                    reading, but close it right-away which then will
 306                    trigger the EOF. */
 307
 308                 fd = session_create_fifo(s);
 309                 if (fd >= 0)
 310                         close_nointr_nofail(fd);
 311         }
 312
 313
 314 finish:
 315         free(remote);
 316         free(kill_processes);
 317         free(seat);
 318         free(vtnr);
 319         free(leader);
 320         free(audit_id);
 321
 322         return r;
 323 }
 324
 325 int session_activate(Session *s) {
 326         int r;
 327
 328         assert(s);
 329
 330         if (s->vtnr < 0)
 331                 return -ENOTSUP;
 332
 333         if (!s->seat)
 334                 return -ENOTSUP;
 335
 336         if (s->seat->active == s)
 337                 return 0;
 338
 339         assert(seat_is_vtconsole(s->seat));
 340
 341         r = chvt(s->vtnr);
 342         if (r < 0)
 343                 return r;
 344
 345         return seat_set_active(s->seat, s);
 346 }
 347
 348 static int session_link_x11_socket(Session *s) {
 349         char *t, *f, *c;
 350         size_t k;
 351
 352         assert(s);
 353         assert(s->user);
 354         assert(s->user->runtime_path);
 355
 356         if (s->user->display)
 357                 return 0;
 358
 359         if (!s->display || !display_is_local(s->display))
 360                 return 0;
 361
 362         k = strspn(s->display+1, "0123456789");
 363         f = new(char, sizeof("/tmp/.X11-unix/X") + k);
 364         if (!f) {
 365                 log_error("Out of memory");
 366                 return -ENOMEM;
 367         }
 368
 369         c = stpcpy(f, "/tmp/.X11-unix/X");
 370         memcpy(c, s->display+1, k);
 371         c[k] = 0;
 372
 373         if (access(f, F_OK) < 0) {
 374                 log_warning("Session %s has display %s with nonexisting socket %s.", s->id, s->display, f);
 375                 free(f);
 376                 return -ENOENT;
 377         }
 378
 379         t = strappend(s->user->runtime_path, "/X11-display");
 380         if (!t) {
 381                 log_error("Out of memory");
 382                 free(f);
 383                 return -ENOMEM;
 384         }
 385
 386         if (link(f, t) < 0) {
 387                 if (errno == EEXIST) {
 388                         unlink(t);
 389
 390                         if (link(f, t) >= 0)
 391                                 goto done;
 392                 }
 393
 394                 if (symlink(f, t) < 0) {
 395
 396                         if (errno == EEXIST) {
 397                                 unlink(t);
 398
 399                                 if (symlink(f, t) >= 0)
 400                                         goto done;
 401                         }
 402
 403                         log_error("Failed to link %s to %s: %m", f, t);
 404                         free(f);
 405                         free(t);
 406                         return -errno;
 407                 }
 408         }
 409
 410 done:
 411         log_info("Linked %s to %s.", f, t);
 412         free(f);
 413         free(t);
 414
 415         s->user->display = s;
 416
 417         return 0;
 418 }
 419
 420 static int session_create_one_group(Session *s, const char *controller, const char *path) {
 421         int r;
 422
 423         assert(s);
 424         assert(controller);
 425         assert(path);
 426
 427         if (s->leader > 0) {
 428                 r = cg_create_and_attach(controller, path, s->leader);
 429                 if (r < 0)
 430                         r = cg_create(controller, path);
 431         } else
 432                 r = cg_create(controller, path);
 433
 434         if (r < 0)
 435                 return r;
 436
 437         r = cg_set_task_access(controller, path, 0644, s->user->uid, s->user->gid);
 438         if (r >= 0)
 439                 r = cg_set_group_access(controller, path, 0755, s->user->uid, s->user->gid);
 440
 441         return r;
 442 }
 443
 444 static int session_create_cgroup(Session *s) {
 445         char **k;
 446         char *p;
 447         int r;
 448
 449         assert(s);
 450         assert(s->user);
 451         assert(s->user->cgroup_path);
 452
 453         if (!s->cgroup_path) {
 454                 if (asprintf(&p, "%s/%s", s->user->cgroup_path, s->id) < 0) {
 455                         log_error("Out of memory");
 456                         return -ENOMEM;
 457                 }
 458         } else
 459                 p = s->cgroup_path;
 460
 461         r = session_create_one_group(s, SYSTEMD_CGROUP_CONTROLLER, p);
 462         if (r < 0) {
 463                 log_error("Failed to create "SYSTEMD_CGROUP_CONTROLLER":%s: %s", p, strerror(-r));
 464                 free(p);
 465                 s->cgroup_path = NULL;
 466                 return r;
 467         }
 468
 469         s->cgroup_path = p;
 470
 471         STRV_FOREACH(k, s->controllers) {
 472
 473                 if (strv_contains(s->reset_controllers, *k))
 474                         continue;
 475
 476                 r = session_create_one_group(s, *k, p);
 477                 if (r < 0)
 478                         log_warning("Failed to create %s:%s: %s", *k, p, strerror(-r));
 479         }
 480
 481         STRV_FOREACH(k, s->manager->controllers) {
 482
 483                 if (strv_contains(s->reset_controllers, *k) ||
 484                     strv_contains(s->manager->reset_controllers, *k) ||
 485                     strv_contains(s->controllers, *k))
 486                         continue;
 487
 488                 r = session_create_one_group(s, *k, p);
 489                 if (r < 0)
 490                         log_warning("Failed to create %s:%s: %s", *k, p, strerror(-r));
 491         }
 492
 493         if (s->leader > 0) {
 494
 495                 STRV_FOREACH(k, s->reset_controllers) {
 496                         r = cg_attach(*k, "/", s->leader);
 497                         if (r < 0)
 498                                 log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
 499
 500                 }
 501
 502                 STRV_FOREACH(k, s->manager->reset_controllers) {
 503
 504                         if (strv_contains(s->reset_controllers, *k) ||
 505                             strv_contains(s->controllers, *k))
 506                                 continue;
 507
 508                         r = cg_attach(*k, "/", s->leader);
 509                         if (r < 0)
 510                                 log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
 511
 512                 }
 513         }
 514
 515         hashmap_put(s->manager->cgroups, s->cgroup_path, s);
 516
 517         return 0;
 518 }
 519
 520 int session_start(Session *s) {
 521         int r;
 522
 523         assert(s);
 524         assert(s->user);
 525
 526         if (s->started)
 527                 return 0;
 528
 529         r = user_start(s->user);
 530         if (r < 0)
 531                 return r;
 532
 533         log_full(s->type == SESSION_TTY || s->type == SESSION_X11 ? LOG_INFO : LOG_DEBUG,
 534                  "New session %s of user %s.", s->id, s->user->name);
 535
 536         /* Create cgroup */
 537         r = session_create_cgroup(s);
 538         if (r < 0)
 539                 return r;
 540
 541         /* Create X11 symlink */
 542         session_link_x11_socket(s);
 543
 544         dual_timestamp_get(&s->timestamp);
 545
 546         if (s->seat)
 547                 seat_read_active_vt(s->seat);
 548
 549         s->started = true;
 550
 551         /* Save session data */
 552         session_save(s);
 553         user_save(s->user);
 554
 555         session_send_signal(s, true);
 556
 557         if (s->seat) {
 558                 seat_save(s->seat);
 559
 560                 if (s->seat->active == s)
 561                         seat_send_changed(s->seat, "Sessions\0ActiveSession\0");
 562                 else
 563                         seat_send_changed(s->seat, "Sessions\0");
 564         }
 565
 566         user_send_changed(s->user, "Sessions\0");
 567
 568         return 0;
 569 }
 570
 571 static bool session_shall_kill(Session *s) {
 572         assert(s);
 573
 574         if (!s->kill_processes)
 575                 return false;
 576
 577         if (strv_contains(s->manager->kill_exclude_users, s->user->name))
 578                 return false;
 579
 580         if (strv_isempty(s->manager->kill_only_users))
 581                 return true;
 582
 583         return strv_contains(s->manager->kill_only_users, s->user->name);
 584 }
 585
 586 static int session_terminate_cgroup(Session *s) {
 587         int r;
 588         char **k;
 589
 590         assert(s);
 591
 592         if (!s->cgroup_path)
 593                 return 0;
 594
 595         cg_trim(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
 596
 597         if (session_shall_kill(s)) {
 598
 599                 r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, true);
 600                 if (r < 0)
 601                         log_error("Failed to kill session cgroup: %s", strerror(-r));
 602
 603         } else {
 604                 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, true);
 605                 if (r < 0)
 606                         log_error("Failed to check session cgroup: %s", strerror(-r));
 607                 else if (r > 0) {
 608                         r = cg_delete(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path);
 609                         if (r < 0)
 610                                 log_error("Failed to delete session cgroup: %s", strerror(-r));
 611                 } else
 612                         r = -EBUSY;
 613         }
 614
 615         STRV_FOREACH(k, s->user->manager->controllers)
 616                 cg_trim(*k, s->cgroup_path, true);
 617
 618         hashmap_remove(s->manager->cgroups, s->cgroup_path);
 619
 620         free(s->cgroup_path);
 621         s->cgroup_path = NULL;
 622
 623         return r;
 624 }
 625
 626 static int session_unlink_x11_socket(Session *s) {
 627         char *t;
 628         int r;
 629
 630         assert(s);
 631         assert(s->user);
 632
 633         if (s->user->display != s)
 634                 return 0;
 635
 636         s->user->display = NULL;
 637
 638         t = strappend(s->user->runtime_path, "/X11-display");
 639         if (!t) {
 640                 log_error("Out of memory");
 641                 return -ENOMEM;
 642         }
 643
 644         r = unlink(t);
 645         free(t);
 646
 647         return r < 0 ? -errno : 0;
 648 }
 649
 650 int session_stop(Session *s) {
 651         int r = 0, k;
 652
 653         assert(s);
 654
 655         if (s->started)
 656                 log_full(s->type == SESSION_TTY || s->type == SESSION_X11 ? LOG_INFO : LOG_DEBUG,
 657                          "Removed session %s.", s->id);
 658
 659         /* Kill cgroup */
 660         k = session_terminate_cgroup(s);
 661         if (k < 0)
 662                 r = k;
 663
 664         /* Remove X11 symlink */
 665         session_unlink_x11_socket(s);
 666
 667         unlink(s->state_file);
 668         session_add_to_gc_queue(s);
 669         user_add_to_gc_queue(s->user);
 670
 671         if (s->started)
 672                 session_send_signal(s, false);
 673
 674         if (s->seat) {
 675                 if (s->seat->active == s)
 676                         seat_set_active(s->seat, NULL);
 677
 678                 seat_send_changed(s->seat, "Sessions\0");
 679         }
 680
 681         user_send_changed(s->user, "Sessions\0");
 682
 683         s->started = false;
 684
 685         return r;
 686 }
 687
 688 bool session_is_active(Session *s) {
 689         assert(s);
 690
 691         if (!s->seat)
 692                 return true;
 693
 694         return s->seat->active == s;
 695 }
 696
 697 int session_get_idle_hint(Session *s, dual_timestamp *t) {
 698         char *p;
 699         struct stat st;
 700         usec_t u, n;
 701         bool b;
 702         int k;
 703
 704         assert(s);
 705
 706         if (s->idle_hint) {
 707                 if (t)
 708                         *t = s->idle_hint_timestamp;
 709
 710                 return s->idle_hint;
 711         }
 712
 713         if (isempty(s->tty))
 714                 goto dont_know;
 715
 716         if (s->tty[0] != '/') {
 717                 p = strappend("/dev/", s->tty);
 718                 if (!p)
 719                         return -ENOMEM;
 720         } else
 721                 p = NULL;
 722
 723         if (!startswith(p ? p : s->tty, "/dev/")) {
 724                 free(p);
 725                 goto dont_know;
 726         }
 727
 728         k = lstat(p ? p : s->tty, &st);
 729         free(p);
 730
 731         if (k < 0)
 732                 goto dont_know;
 733
 734         u = timespec_load(&st.st_atim);
 735         n = now(CLOCK_REALTIME);
 736         b = u + IDLE_THRESHOLD_USEC < n;
 737
 738         if (t)
 739                 dual_timestamp_from_realtime(t, u + b ? IDLE_THRESHOLD_USEC : 0);
 740
 741         return b;
 742
 743 dont_know:
 744         if (t)
 745                 *t = s->idle_hint_timestamp;
 746
 747         return 0;
 748 }
 749
 750 void session_set_idle_hint(Session *s, bool b) {
 751         assert(s);
 752
 753         if (s->idle_hint == b)
 754                 return;
 755
 756         s->idle_hint = b;
 757         dual_timestamp_get(&s->idle_hint_timestamp);
 758
 759         session_send_changed(s,
 760                              "IdleHint\0"
 761                              "IdleSinceHint\0"
 762                              "IdleSinceHintMonotonic\0");
 763
 764         if (s->seat)
 765                 seat_send_changed(s->seat,
 766                                   "IdleHint\0"
 767                                   "IdleSinceHint\0"
 768                                   "IdleSinceHintMonotonic\0");
 769
 770         user_send_changed(s->user,
 771                           "IdleHint\0"
 772                           "IdleSinceHint\0"
 773                           "IdleSinceHintMonotonic\0");
 774
 775         manager_send_changed(s->manager,
 776                              "IdleHint\0"
 777                              "IdleSinceHint\0"
 778                              "IdleSinceHintMonotonic\0");
 779 }
 780
 781 int session_create_fifo(Session *s) {
 782         int r;
 783
 784         assert(s);
 785
 786         /* Create FIFO */
 787         if (!s->fifo_path) {
 788                 r = safe_mkdir("/run/systemd/sessions", 0755, 0, 0);
 789                 if (r < 0)
 790                         return r;
 791
 792                 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
 793                         return -ENOMEM;
 794
 795                 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
 796                         return -errno;
 797         }
 798
 799         /* Open reading side */
 800         if (s->fifo_fd < 0) {
 801                 struct epoll_event ev;
 802
 803                 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
 804                 if (s->fifo_fd < 0)
 805                         return -errno;
 806
 807                 r = hashmap_put(s->manager->fifo_fds, INT_TO_PTR(s->fifo_fd + 1), s);
 808                 if (r < 0)
 809                         return r;
 810
 811                 zero(ev);
 812                 ev.events = 0;
 813                 ev.data.u32 = FD_FIFO_BASE + s->fifo_fd;
 814
 815                 if (epoll_ctl(s->manager->epoll_fd, EPOLL_CTL_ADD, s->fifo_fd, &ev) < 0)
 816                         return -errno;
 817         }
 818
 819         /* Open writing side */
 820         r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
 821         if (r < 0)
 822                 return -errno;
 823
 824         return r;
 825 }
 826
 827 void session_remove_fifo(Session *s) {
 828         assert(s);
 829
 830         if (s->fifo_fd >= 0) {
 831                 assert_se(hashmap_remove(s->manager->fifo_fds, INT_TO_PTR(s->fifo_fd + 1)) == s);
 832                 assert_se(epoll_ctl(s->manager->epoll_fd, EPOLL_CTL_DEL, s->fifo_fd, NULL) == 0);
 833                 close_nointr_nofail(s->fifo_fd);
 834                 s->fifo_fd = -1;
 835         }
 836
 837         if (s->fifo_path) {
 838                 unlink(s->fifo_path);
 839                 free(s->fifo_path);
 840                 s->fifo_path = NULL;
 841         }
 842 }
 843
 844 int session_check_gc(Session *s, bool drop_not_started) {
 845         int r;
 846
 847         assert(s);
 848
 849         if (drop_not_started && !s->started)
 850                 return 0;
 851
 852         if (s->fifo_fd >= 0) {
 853
 854                 r = pipe_eof(s->fifo_fd);
 855                 if (r < 0)
 856                         return r;
 857
 858                 if (r == 0)
 859                         return 1;
 860         }
 861
 862         if (s->cgroup_path) {
 863
 864                 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
 865                 if (r < 0)
 866                         return r;
 867
 868                 if (r <= 0)
 869                         return 1;
 870         }
 871
 872         return 0;
 873 }
 874
 875 void session_add_to_gc_queue(Session *s) {
 876         assert(s);
 877
 878         if (s->in_gc_queue)
 879                 return;
 880
 881         LIST_PREPEND(Session, gc_queue, s->manager->session_gc_queue, s);
 882         s->in_gc_queue = true;
 883 }
 884
 885 int session_kill(Session *s, KillWho who, int signo) {
 886         int r = 0;
 887         Set *pid_set = NULL;
 888
 889         assert(s);
 890
 891         if (!s->cgroup_path)
 892                 return -ESRCH;
 893
 894         if (s->leader <= 0 && who == KILL_LEADER)
 895                 return -ESRCH;
 896
 897         if (s->leader > 0)
 898                 if (kill(s->leader, signo) < 0)
 899                         r = -errno;
 900
 901         if (who == KILL_ALL) {
 902                 int q;
 903
 904                 pid_set = set_new(trivial_hash_func, trivial_compare_func);
 905                 if (!pid_set)
 906                         return -ENOMEM;
 907
 908                 if (s->leader > 0) {
 909                         q = set_put(pid_set, LONG_TO_PTR(s->leader));
 910                         if (q < 0)
 911                                 r = q;
 912                 }
 913
 914                 q = cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, signo, false, true, false, pid_set);
 915                 if (q < 0)
 916                         if (q != -EAGAIN && q != -ESRCH && q != -ENOENT)
 917                                 r = q;
 918         }
 919
 920         if (pid_set)
 921                 set_free(pid_set);
 922
 923         return r;
 924 }
 925
 926 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
 927         [SESSION_TTY] = "tty",
 928         [SESSION_X11] = "x11",
 929         [SESSION_UNSPECIFIED] = "unspecified"
 930 };
 931
 932 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
 933
 934 static const char* const kill_who_table[_KILL_WHO_MAX] = {
 935         [KILL_LEADER] = "leader",
 936         [KILL_ALL] = "all"
 937 };
 938
 939 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);