src/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_is_vtconsole(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_is_vtconsole(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         session_open_fifo(s);
 301
 302 finish:
 303         free(remote);
 304         free(kill_processes);
 305         free(seat);
 306         free(vtnr);
 307         free(leader);
 308         free(audit_id);
 309
 310         return r;
 311 }
 312
 313 int session_activate(Session *s) {
 314         int r;
 315         Session *old_active;
 316
 317         assert(s);
 318
 319         if (s->vtnr < 0)
 320                 return -ENOTSUP;
 321
 322         if (!s->seat)
 323                 return -ENOTSUP;
 324
 325         if (s->seat->active == s)
 326                 return 0;
 327
 328         assert(seat_is_vtconsole(s->seat));
 329
 330         r = chvt(s->vtnr);
 331         if (r < 0)
 332                 return r;
 333
 334         old_active = s->seat->active;
 335         s->seat->active = s;
 336
 337         return seat_apply_acls(s->seat, old_active);
 338 }
 339
 340 static int session_link_x11_socket(Session *s) {
 341         char *t, *f, *c;
 342         size_t k;
 343
 344         assert(s);
 345         assert(s->user);
 346         assert(s->user->runtime_path);
 347
 348         if (s->user->display)
 349                 return 0;
 350
 351         if (!s->display || !display_is_local(s->display))
 352                 return 0;
 353
 354         k = strspn(s->display+1, "0123456789");
 355         f = new(char, sizeof("/tmp/.X11-unix/X") + k);
 356         if (!f) {
 357                 log_error("Out of memory");
 358                 return -ENOMEM;
 359         }
 360
 361         c = stpcpy(f, "/tmp/.X11-unix/X");
 362         memcpy(c, s->display+1, k);
 363         c[k] = 0;
 364
 365         if (access(f, F_OK) < 0) {
 366                 log_warning("Session %s has display %s with nonexisting socket %s.", s->id, s->display, f);
 367                 free(f);
 368                 return -ENOENT;
 369         }
 370
 371         t = strappend(s->user->runtime_path, "/display");
 372         if (!t) {
 373                 log_error("Out of memory");
 374                 free(f);
 375                 return -ENOMEM;
 376         }
 377
 378         if (link(f, t) < 0) {
 379                 if (errno == EEXIST) {
 380                         unlink(t);
 381
 382                         if (link(f, t) >= 0)
 383                                 goto done;
 384                 }
 385
 386                 if (symlink(f, t) < 0) {
 387
 388                         if (errno == EEXIST) {
 389                                 unlink(t);
 390
 391                                 if (symlink(f, t) >= 0)
 392                                         goto done;
 393                         }
 394
 395                         log_error("Failed to link %s to %s: %m", f, t);
 396                         free(f);
 397                         free(t);
 398                         return -errno;
 399                 }
 400         }
 401
 402 done:
 403         log_info("Linked %s to %s.", f, t);
 404         free(f);
 405         free(t);
 406
 407         s->user->display = s;
 408
 409         return 0;
 410 }
 411
 412 static int session_create_one_group(Session *s, const char *controller, const char *path) {
 413         int r;
 414
 415         assert(s);
 416         assert(controller);
 417         assert(path);
 418
 419         if (s->leader > 0) {
 420                 r = cg_create_and_attach(controller, path, s->leader);
 421                 if (r < 0)
 422                         r = cg_create(controller, path);
 423         } else
 424                 r = cg_create(controller, path);
 425
 426         if (r < 0)
 427                 return r;
 428
 429         r = cg_set_task_access(controller, path, 0644, s->user->uid, s->user->gid);
 430         if (r >= 0)
 431                 r = cg_set_group_access(controller, path, 0755, s->user->uid, s->user->gid);
 432
 433         return r;
 434 }
 435
 436 static int session_create_cgroup(Session *s) {
 437         char **k;
 438         char *p;
 439         int r;
 440
 441         assert(s);
 442         assert(s->user);
 443         assert(s->user->cgroup_path);
 444
 445         if (!s->cgroup_path) {
 446                 if (asprintf(&p, "%s/%s", s->user->cgroup_path, s->id) < 0) {
 447                         log_error("Out of memory");
 448                         return -ENOMEM;
 449                 }
 450         } else
 451                 p = s->cgroup_path;
 452
 453         r = session_create_one_group(s, SYSTEMD_CGROUP_CONTROLLER, p);
 454         if (r < 0) {
 455                 log_error("Failed to create "SYSTEMD_CGROUP_CONTROLLER":%s: %s", p, strerror(-r));
 456                 free(p);
 457                 s->cgroup_path = NULL;
 458                 return r;
 459         }
 460
 461         s->cgroup_path = p;
 462
 463         STRV_FOREACH(k, s->controllers) {
 464
 465                 if (strv_contains(s->reset_controllers, *k))
 466                         continue;
 467
 468                 r = session_create_one_group(s, *k, p);
 469                 if (r < 0)
 470                         log_warning("Failed to create %s:%s: %s", *k, p, strerror(-r));
 471         }
 472
 473         STRV_FOREACH(k, s->manager->controllers) {
 474
 475                 if (strv_contains(s->reset_controllers, *k) ||
 476                     strv_contains(s->controllers, *k))
 477                         continue;
 478
 479                 r = session_create_one_group(s, *k, p);
 480                 if (r < 0)
 481                         log_warning("Failed to create %s:%s: %s", *k, p, strerror(-r));
 482         }
 483
 484         if (s->leader > 0) {
 485
 486                 STRV_FOREACH(k, s->reset_controllers) {
 487                         r = cg_attach(*k, "/", s->leader);
 488                         if (r < 0)
 489                                 log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
 490
 491                 }
 492         }
 493
 494         hashmap_put(s->manager->cgroups, s->cgroup_path, s);
 495
 496         return 0;
 497 }
 498
 499 int session_start(Session *s) {
 500         int r;
 501
 502         assert(s);
 503         assert(s->user);
 504
 505         if (s->started)
 506                 return 0;
 507
 508         r = user_start(s->user);
 509         if (r < 0)
 510                 return r;
 511
 512         log_info("New session %s of user %s.", s->id, s->user->name);
 513
 514         /* Create cgroup */
 515         r = session_create_cgroup(s);
 516         if (r < 0)
 517                 return r;
 518
 519         /* Create X11 symlink */
 520         session_link_x11_socket(s);
 521
 522         dual_timestamp_get(&s->timestamp);
 523
 524         if (s->seat)
 525                 seat_read_active_vt(s->seat);
 526
 527         s->started = true;
 528
 529         /* Save session data */
 530         session_save(s);
 531         user_save(s->user);
 532
 533         session_send_signal(s, true);
 534
 535         if (s->seat) {
 536                 seat_save(s->seat);
 537
 538                 if (s->seat->active == s)
 539                         seat_send_changed(s->seat, "Sessions\0ActiveSession\0");
 540                 else
 541                         seat_send_changed(s->seat, "Sessions\0");
 542         }
 543
 544         user_send_changed(s->user, "Sessions\0");
 545
 546         return 0;
 547 }
 548
 549 static bool session_shall_kill(Session *s) {
 550         assert(s);
 551
 552         if (!s->kill_processes)
 553                 return false;
 554
 555         if (strv_contains(s->manager->kill_exclude_users, s->user->name))
 556                 return false;
 557
 558         if (strv_isempty(s->manager->kill_only_users))
 559                 return true;
 560
 561         return strv_contains(s->manager->kill_only_users, s->user->name);
 562 }
 563
 564 static int session_kill_cgroup(Session *s) {
 565         int r;
 566         char **k;
 567
 568         assert(s);
 569
 570         if (!s->cgroup_path)
 571                 return 0;
 572
 573         cg_trim(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
 574
 575         if (session_shall_kill(s)) {
 576
 577                 r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, true);
 578                 if (r < 0)
 579                         log_error("Failed to kill session cgroup: %s", strerror(-r));
 580
 581         } else {
 582                 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, true);
 583                 if (r < 0)
 584                         log_error("Failed to check session cgroup: %s", strerror(-r));
 585                 else if (r > 0) {
 586                         r = cg_delete(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path);
 587                         if (r < 0)
 588                                 log_error("Failed to delete session cgroup: %s", strerror(-r));
 589                 } else
 590                         r = -EBUSY;
 591         }
 592
 593         STRV_FOREACH(k, s->user->manager->controllers)
 594                 cg_trim(*k, s->cgroup_path, true);
 595
 596         hashmap_remove(s->manager->cgroups, s->cgroup_path);
 597
 598         free(s->cgroup_path);
 599         s->cgroup_path = NULL;
 600
 601         return r;
 602 }
 603
 604 static int session_unlink_x11_socket(Session *s) {
 605         char *t;
 606         int r;
 607
 608         assert(s);
 609         assert(s->user);
 610
 611         if (s->user->display != s)
 612                 return 0;
 613
 614         s->user->display = NULL;
 615
 616         t = strappend(s->user->runtime_path, "/display");
 617         if (!t) {
 618                 log_error("Out of memory");
 619                 return -ENOMEM;
 620         }
 621
 622         r = unlink(t);
 623         free(t);
 624
 625         return r < 0 ? -errno : 0;
 626 }
 627
 628 int session_stop(Session *s) {
 629         int r = 0, k;
 630
 631         assert(s);
 632
 633         if (s->started)
 634                 log_info("Removed session %s.", s->id);
 635
 636         /* Kill cgroup */
 637         k = session_kill_cgroup(s);
 638         if (k < 0)
 639                 r = k;
 640
 641         /* Remove X11 symlink */
 642         session_unlink_x11_socket(s);
 643
 644         unlink(s->state_file);
 645         session_add_to_gc_queue(s);
 646         user_add_to_gc_queue(s->user);
 647
 648         if (s->started)
 649                 session_send_signal(s, false);
 650
 651         if (s->seat) {
 652                 if (s->seat->active == s)
 653                         seat_set_active(s->seat, NULL);
 654
 655                 seat_send_changed(s->seat, "Sessions\0");
 656         }
 657
 658         user_send_changed(s->user, "Sessions\0");
 659
 660         s->started = false;
 661
 662         return r;
 663 }
 664
 665 bool session_is_active(Session *s) {
 666         assert(s);
 667
 668         if (!s->seat)
 669                 return true;
 670
 671         return s->seat->active == s;
 672 }
 673
 674 int session_get_idle_hint(Session *s, dual_timestamp *t) {
 675         char *p;
 676         struct stat st;
 677         usec_t u, n;
 678         bool b;
 679         int k;
 680
 681         assert(s);
 682
 683         if (s->idle_hint) {
 684                 if (t)
 685                         *t = s->idle_hint_timestamp;
 686
 687                 return s->idle_hint;
 688         }
 689
 690         if (isempty(s->tty))
 691                 goto dont_know;
 692
 693         if (s->tty[0] != '/') {
 694                 p = strappend("/dev/", s->tty);
 695                 if (!p)
 696                         return -ENOMEM;
 697         } else
 698                 p = NULL;
 699
 700         if (!startswith(p ? p : s->tty, "/dev/")) {
 701                 free(p);
 702                 goto dont_know;
 703         }
 704
 705         k = lstat(p ? p : s->tty, &st);
 706         free(p);
 707
 708         if (k < 0)
 709                 goto dont_know;
 710
 711         u = timespec_load(&st.st_atim);
 712         n = now(CLOCK_REALTIME);
 713         b = u + IDLE_THRESHOLD_USEC < n;
 714
 715         if (t)
 716                 dual_timestamp_from_realtime(t, u + b ? IDLE_THRESHOLD_USEC : 0);
 717
 718         return b;
 719
 720 dont_know:
 721         if (t)
 722                 *t = s->idle_hint_timestamp;
 723
 724         return 0;
 725 }
 726
 727 void session_set_idle_hint(Session *s, bool b) {
 728         assert(s);
 729
 730         if (s->idle_hint == b)
 731                 return;
 732
 733         s->idle_hint = b;
 734         dual_timestamp_get(&s->idle_hint_timestamp);
 735
 736         session_send_changed(s,
 737                              "IdleHint\0"
 738                              "IdleSinceHint\0"
 739                              "IdleSinceHintMonotonic\0");
 740
 741         if (s->seat)
 742                 seat_send_changed(s->seat,
 743                                   "IdleHint\0"
 744                                   "IdleSinceHint\0"
 745                                   "IdleSinceHintMonotonic\0");
 746
 747         user_send_changed(s->user,
 748                           "IdleHint\0"
 749                           "IdleSinceHint\0"
 750                           "IdleSinceHintMonotonic\0");
 751
 752         manager_send_changed(s->manager,
 753                              "IdleHint\0"
 754                              "IdleSinceHint\0"
 755                              "IdleSinceHintMonotonic\0");
 756 }
 757
 758 int session_open_fifo(Session *s) {
 759         struct epoll_event ev;
 760         int r;
 761
 762         assert(s);
 763
 764         if (s->fifo_fd >= 0)
 765                 return 0;
 766
 767         if (!s->fifo_path)
 768                 return -EINVAL;
 769
 770         s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
 771         if (s->fifo_fd < 0)
 772                 return -errno;
 773
 774         r = hashmap_put(s->manager->fifo_fds, INT_TO_PTR(s->fifo_fd + 1), s);
 775         if (r < 0)
 776                 return r;
 777
 778         zero(ev);
 779         ev.events = 0;
 780         ev.data.u32 = FD_FIFO_BASE + s->fifo_fd;
 781
 782         if (epoll_ctl(s->manager->epoll_fd, EPOLL_CTL_ADD, s->fifo_fd, &ev) < 0)
 783                 return -errno;
 784
 785         return 0;
 786 }
 787
 788 int session_create_fifo(Session *s) {
 789         int r;
 790
 791         assert(s);
 792
 793         if (!s->fifo_path) {
 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         r = session_open_fifo(s);
 803         if (r < 0)
 804                 return r;
 805
 806         /* Open writing side */
 807         r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
 808         if (r < 0)
 809                 return -errno;
 810
 811         return r;
 812 }
 813
 814 void session_remove_fifo(Session *s) {
 815         assert(s);
 816
 817         if (s->fifo_fd >= 0) {
 818                 assert_se(hashmap_remove(s->manager->fifo_fds, INT_TO_PTR(s->fifo_fd + 1)) == s);
 819                 assert_se(epoll_ctl(s->manager->epoll_fd, EPOLL_CTL_DEL, s->fifo_fd, NULL) == 0);
 820                 close_nointr_nofail(s->fifo_fd);
 821                 s->fifo_fd = -1;
 822         }
 823
 824         if (s->fifo_path) {
 825                 unlink(s->fifo_path);
 826                 free(s->fifo_path);
 827                 s->fifo_path = NULL;
 828         }
 829 }
 830
 831 int session_check_gc(Session *s) {
 832         int r;
 833
 834         assert(s);
 835
 836         if (!s->started)
 837                 return 0;
 838
 839         if (s->fifo_fd >= 0) {
 840
 841                 r = pipe_eof(s->fifo_fd);
 842                 if (r < 0)
 843                         return r;
 844
 845                 if (r == 0)
 846                         return 1;
 847         }
 848
 849         if (s->cgroup_path) {
 850
 851                 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
 852                 if (r < 0)
 853                         return r;
 854
 855                 if (r <= 0)
 856                         return 1;
 857         }
 858
 859         return 0;
 860 }
 861
 862 void session_add_to_gc_queue(Session *s) {
 863         assert(s);
 864
 865         if (s->in_gc_queue)
 866                 return;
 867
 868         LIST_PREPEND(Session, gc_queue, s->manager->session_gc_queue, s);
 869         s->in_gc_queue = true;
 870 }
 871
 872 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
 873         [SESSION_TTY] = "tty",
 874         [SESSION_X11] = "x11",
 875         [SESSION_UNSPECIFIED] = "unspecified"
 876 };
 877
 878 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);