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         mkdir_parents(t, 0755);
 387
 388         if (link(f, t) < 0) {
 389                 if (errno == EEXIST) {
 390                         unlink(t);
 391
 392                         if (link(f, t) >= 0)
 393                                 goto done;
 394                 }
 395
 396                 if (symlink(f, t) < 0) {
 397
 398                         if (errno == EEXIST) {
 399                                 unlink(t);
 400
 401                                 if (symlink(f, t) >= 0)
 402                                         goto done;
 403                         }
 404
 405                         log_error("Failed to link %s to %s: %m", f, t);
 406                         free(f);
 407                         free(t);
 408                         return -errno;
 409                 }
 410         }
 411
 412 done:
 413         log_info("Linked %s to %s.", f, t);
 414         free(f);
 415         free(t);
 416
 417         s->user->display = s;
 418
 419         return 0;
 420 }
 421
 422 static int session_create_one_group(Session *s, const char *controller, const char *path) {
 423         int r;
 424
 425         assert(s);
 426         assert(controller);
 427         assert(path);
 428
 429         if (s->leader > 0) {
 430                 r = cg_create_and_attach(controller, path, s->leader);
 431                 if (r < 0)
 432                         r = cg_create(controller, path);
 433         } else
 434                 r = cg_create(controller, path);
 435
 436         if (r < 0)
 437                 return r;
 438
 439         r = cg_set_task_access(controller, path, 0644, s->user->uid, s->user->gid);
 440         if (r >= 0)
 441                 r = cg_set_group_access(controller, path, 0755, s->user->uid, s->user->gid);
 442
 443         return r;
 444 }
 445
 446 static int session_create_cgroup(Session *s) {
 447         char **k;
 448         char *p;
 449         int r;
 450
 451         assert(s);
 452         assert(s->user);
 453         assert(s->user->cgroup_path);
 454
 455         if (!s->cgroup_path) {
 456                 if (asprintf(&p, "%s/%s", s->user->cgroup_path, s->id) < 0) {
 457                         log_error("Out of memory");
 458                         return -ENOMEM;
 459                 }
 460         } else
 461                 p = s->cgroup_path;
 462
 463         r = session_create_one_group(s, SYSTEMD_CGROUP_CONTROLLER, p);
 464         if (r < 0) {
 465                 log_error("Failed to create "SYSTEMD_CGROUP_CONTROLLER":%s: %s", p, strerror(-r));
 466                 free(p);
 467                 s->cgroup_path = NULL;
 468                 return r;
 469         }
 470
 471         s->cgroup_path = p;
 472
 473         STRV_FOREACH(k, s->controllers) {
 474
 475                 if (strv_contains(s->reset_controllers, *k))
 476                         continue;
 477
 478                 r = session_create_one_group(s, *k, p);
 479                 if (r < 0)
 480                         log_warning("Failed to create %s:%s: %s", *k, p, strerror(-r));
 481         }
 482
 483         STRV_FOREACH(k, s->manager->controllers) {
 484
 485                 if (strv_contains(s->reset_controllers, *k) ||
 486                     strv_contains(s->manager->reset_controllers, *k) ||
 487                     strv_contains(s->controllers, *k))
 488                         continue;
 489
 490                 r = session_create_one_group(s, *k, p);
 491                 if (r < 0)
 492                         log_warning("Failed to create %s:%s: %s", *k, p, strerror(-r));
 493         }
 494
 495         if (s->leader > 0) {
 496
 497                 STRV_FOREACH(k, s->reset_controllers) {
 498                         r = cg_attach(*k, "/", s->leader);
 499                         if (r < 0)
 500                                 log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
 501
 502                 }
 503
 504                 STRV_FOREACH(k, s->manager->reset_controllers) {
 505
 506                         if (strv_contains(s->reset_controllers, *k) ||
 507                             strv_contains(s->controllers, *k))
 508                                 continue;
 509
 510                         r = cg_attach(*k, "/", s->leader);
 511                         if (r < 0)
 512                                 log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
 513
 514                 }
 515         }
 516
 517         hashmap_put(s->manager->cgroups, s->cgroup_path, s);
 518
 519         return 0;
 520 }
 521
 522 int session_start(Session *s) {
 523         int r;
 524
 525         assert(s);
 526         assert(s->user);
 527
 528         if (s->started)
 529                 return 0;
 530
 531         r = user_start(s->user);
 532         if (r < 0)
 533                 return r;
 534
 535         log_full(s->type == SESSION_TTY || s->type == SESSION_X11 ? LOG_INFO : LOG_DEBUG,
 536                  "New session %s of user %s.", s->id, s->user->name);
 537
 538         /* Create cgroup */
 539         r = session_create_cgroup(s);
 540         if (r < 0)
 541                 return r;
 542
 543         /* Create X11 symlink */
 544         session_link_x11_socket(s);
 545
 546         dual_timestamp_get(&s->timestamp);
 547
 548         if (s->seat)
 549                 seat_read_active_vt(s->seat);
 550
 551         s->started = true;
 552
 553         /* Save session data */
 554         session_save(s);
 555         user_save(s->user);
 556
 557         session_send_signal(s, true);
 558
 559         if (s->seat) {
 560                 seat_save(s->seat);
 561
 562                 if (s->seat->active == s)
 563                         seat_send_changed(s->seat, "Sessions\0ActiveSession\0");
 564                 else
 565                         seat_send_changed(s->seat, "Sessions\0");
 566         }
 567
 568         user_send_changed(s->user, "Sessions\0");
 569
 570         return 0;
 571 }
 572
 573 static bool session_shall_kill(Session *s) {
 574         assert(s);
 575
 576         if (!s->kill_processes)
 577                 return false;
 578
 579         if (strv_contains(s->manager->kill_exclude_users, s->user->name))
 580                 return false;
 581
 582         if (strv_isempty(s->manager->kill_only_users))
 583                 return true;
 584
 585         return strv_contains(s->manager->kill_only_users, s->user->name);
 586 }
 587
 588 static int session_terminate_cgroup(Session *s) {
 589         int r;
 590         char **k;
 591
 592         assert(s);
 593
 594         if (!s->cgroup_path)
 595                 return 0;
 596
 597         cg_trim(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
 598
 599         if (session_shall_kill(s)) {
 600
 601                 r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, true);
 602                 if (r < 0)
 603                         log_error("Failed to kill session cgroup: %s", strerror(-r));
 604
 605         } else {
 606                 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, true);
 607                 if (r < 0)
 608                         log_error("Failed to check session cgroup: %s", strerror(-r));
 609                 else if (r > 0) {
 610                         r = cg_delete(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path);
 611                         if (r < 0)
 612                                 log_error("Failed to delete session cgroup: %s", strerror(-r));
 613                 } else
 614                         r = -EBUSY;
 615         }
 616
 617         STRV_FOREACH(k, s->user->manager->controllers)
 618                 cg_trim(*k, s->cgroup_path, true);
 619
 620         hashmap_remove(s->manager->cgroups, s->cgroup_path);
 621
 622         free(s->cgroup_path);
 623         s->cgroup_path = NULL;
 624
 625         return r;
 626 }
 627
 628 static int session_unlink_x11_socket(Session *s) {
 629         char *t;
 630         int r;
 631
 632         assert(s);
 633         assert(s->user);
 634
 635         if (s->user->display != s)
 636                 return 0;
 637
 638         s->user->display = NULL;
 639
 640         t = strappend(s->user->runtime_path, "/X11/display");
 641         if (!t) {
 642                 log_error("Out of memory");
 643                 return -ENOMEM;
 644         }
 645
 646         r = unlink(t);
 647         free(t);
 648
 649         return r < 0 ? -errno : 0;
 650 }
 651
 652 int session_stop(Session *s) {
 653         int r = 0, k;
 654
 655         assert(s);
 656
 657         if (s->started)
 658                 log_full(s->type == SESSION_TTY || s->type == SESSION_X11 ? LOG_INFO : LOG_DEBUG,
 659                          "Removed session %s.", s->id);
 660
 661         /* Kill cgroup */
 662         k = session_terminate_cgroup(s);
 663         if (k < 0)
 664                 r = k;
 665
 666         /* Remove X11 symlink */
 667         session_unlink_x11_socket(s);
 668
 669         unlink(s->state_file);
 670         session_add_to_gc_queue(s);
 671         user_add_to_gc_queue(s->user);
 672
 673         if (s->started)
 674                 session_send_signal(s, false);
 675
 676         if (s->seat) {
 677                 if (s->seat->active == s)
 678                         seat_set_active(s->seat, NULL);
 679
 680                 seat_send_changed(s->seat, "Sessions\0");
 681         }
 682
 683         user_send_changed(s->user, "Sessions\0");
 684
 685         s->started = false;
 686
 687         return r;
 688 }
 689
 690 bool session_is_active(Session *s) {
 691         assert(s);
 692
 693         if (!s->seat)
 694                 return true;
 695
 696         return s->seat->active == s;
 697 }
 698
 699 int session_get_idle_hint(Session *s, dual_timestamp *t) {
 700         char *p;
 701         struct stat st;
 702         usec_t u, n;
 703         bool b;
 704         int k;
 705
 706         assert(s);
 707
 708         if (s->idle_hint) {
 709                 if (t)
 710                         *t = s->idle_hint_timestamp;
 711
 712                 return s->idle_hint;
 713         }
 714
 715         if (isempty(s->tty))
 716                 goto dont_know;
 717
 718         if (s->tty[0] != '/') {
 719                 p = strappend("/dev/", s->tty);
 720                 if (!p)
 721                         return -ENOMEM;
 722         } else
 723                 p = NULL;
 724
 725         if (!startswith(p ? p : s->tty, "/dev/")) {
 726                 free(p);
 727                 goto dont_know;
 728         }
 729
 730         k = lstat(p ? p : s->tty, &st);
 731         free(p);
 732
 733         if (k < 0)
 734                 goto dont_know;
 735
 736         u = timespec_load(&st.st_atim);
 737         n = now(CLOCK_REALTIME);
 738         b = u + IDLE_THRESHOLD_USEC < n;
 739
 740         if (t)
 741                 dual_timestamp_from_realtime(t, u + b ? IDLE_THRESHOLD_USEC : 0);
 742
 743         return b;
 744
 745 dont_know:
 746         if (t)
 747                 *t = s->idle_hint_timestamp;
 748
 749         return 0;
 750 }
 751
 752 void session_set_idle_hint(Session *s, bool b) {
 753         assert(s);
 754
 755         if (s->idle_hint == b)
 756                 return;
 757
 758         s->idle_hint = b;
 759         dual_timestamp_get(&s->idle_hint_timestamp);
 760
 761         session_send_changed(s,
 762                              "IdleHint\0"
 763                              "IdleSinceHint\0"
 764                              "IdleSinceHintMonotonic\0");
 765
 766         if (s->seat)
 767                 seat_send_changed(s->seat,
 768                                   "IdleHint\0"
 769                                   "IdleSinceHint\0"
 770                                   "IdleSinceHintMonotonic\0");
 771
 772         user_send_changed(s->user,
 773                           "IdleHint\0"
 774                           "IdleSinceHint\0"
 775                           "IdleSinceHintMonotonic\0");
 776
 777         manager_send_changed(s->manager,
 778                              "IdleHint\0"
 779                              "IdleSinceHint\0"
 780                              "IdleSinceHintMonotonic\0");
 781 }
 782
 783 int session_create_fifo(Session *s) {
 784         int r;
 785
 786         assert(s);
 787
 788         /* Create FIFO */
 789         if (!s->fifo_path) {
 790                 r = safe_mkdir("/run/systemd/sessions", 0755, 0, 0);
 791                 if (r < 0)
 792                         return r;
 793
 794                 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
 795                         return -ENOMEM;
 796
 797                 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
 798                         return -errno;
 799         }
 800
 801         /* Open reading side */
 802         if (s->fifo_fd < 0) {
 803                 struct epoll_event ev;
 804
 805                 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
 806                 if (s->fifo_fd < 0)
 807                         return -errno;
 808
 809                 r = hashmap_put(s->manager->fifo_fds, INT_TO_PTR(s->fifo_fd + 1), s);
 810                 if (r < 0)
 811                         return r;
 812
 813                 zero(ev);
 814                 ev.events = 0;
 815                 ev.data.u32 = FD_FIFO_BASE + s->fifo_fd;
 816
 817                 if (epoll_ctl(s->manager->epoll_fd, EPOLL_CTL_ADD, s->fifo_fd, &ev) < 0)
 818                         return -errno;
 819         }
 820
 821         /* Open writing side */
 822         r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
 823         if (r < 0)
 824                 return -errno;
 825
 826         return r;
 827 }
 828
 829 void session_remove_fifo(Session *s) {
 830         assert(s);
 831
 832         if (s->fifo_fd >= 0) {
 833                 assert_se(hashmap_remove(s->manager->fifo_fds, INT_TO_PTR(s->fifo_fd + 1)) == s);
 834                 assert_se(epoll_ctl(s->manager->epoll_fd, EPOLL_CTL_DEL, s->fifo_fd, NULL) == 0);
 835                 close_nointr_nofail(s->fifo_fd);
 836                 s->fifo_fd = -1;
 837         }
 838
 839         if (s->fifo_path) {
 840                 unlink(s->fifo_path);
 841                 free(s->fifo_path);
 842                 s->fifo_path = NULL;
 843         }
 844 }
 845
 846 int session_check_gc(Session *s, bool drop_not_started) {
 847         int r;
 848
 849         assert(s);
 850
 851         if (drop_not_started && !s->started)
 852                 return 0;
 853
 854         if (s->fifo_fd >= 0) {
 855
 856                 r = pipe_eof(s->fifo_fd);
 857                 if (r < 0)
 858                         return r;
 859
 860                 if (r == 0)
 861                         return 1;
 862         }
 863
 864         if (s->cgroup_path) {
 865
 866                 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
 867                 if (r < 0)
 868                         return r;
 869
 870                 if (r <= 0)
 871                         return 1;
 872         }
 873
 874         return 0;
 875 }
 876
 877 void session_add_to_gc_queue(Session *s) {
 878         assert(s);
 879
 880         if (s->in_gc_queue)
 881                 return;
 882
 883         LIST_PREPEND(Session, gc_queue, s->manager->session_gc_queue, s);
 884         s->in_gc_queue = true;
 885 }
 886
 887 int session_kill(Session *s, KillWho who, int signo) {
 888         int r = 0;
 889         Set *pid_set = NULL;
 890
 891         assert(s);
 892
 893         if (!s->cgroup_path)
 894                 return -ESRCH;
 895
 896         if (s->leader <= 0 && who == KILL_LEADER)
 897                 return -ESRCH;
 898
 899         if (s->leader > 0)
 900                 if (kill(s->leader, signo) < 0)
 901                         r = -errno;
 902
 903         if (who == KILL_ALL) {
 904                 int q;
 905
 906                 pid_set = set_new(trivial_hash_func, trivial_compare_func);
 907                 if (!pid_set)
 908                         return -ENOMEM;
 909
 910                 if (s->leader > 0) {
 911                         q = set_put(pid_set, LONG_TO_PTR(s->leader));
 912                         if (q < 0)
 913                                 r = q;
 914                 }
 915
 916                 q = cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, signo, false, true, false, pid_set);
 917                 if (q < 0)
 918                         if (q != -EAGAIN && q != -ESRCH && q != -ENOENT)
 919                                 r = q;
 920         }
 921
 922         if (pid_set)
 923                 set_free(pid_set);
 924
 925         return r;
 926 }
 927
 928 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
 929         [SESSION_TTY] = "tty",
 930         [SESSION_X11] = "x11",
 931         [SESSION_UNSPECIFIED] = "unspecified"
 932 };
 933
 934 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
 935
 936 static const char* const kill_who_table[_KILL_WHO_MAX] = {
 937         [KILL_LEADER] = "leader",
 938         [KILL_ALL] = "all"
 939 };
 940
 941 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);