src/libsystemd/sd-login/sd-login.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 Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 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   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <unistd.h>
  23 #include <string.h>
  24 #include <errno.h>
  25 #include <sys/inotify.h>
  26 #include <poll.h>
  27
  28 #include "util.h"
  29 #include "cgroup-util.h"
  30 #include "macro.h"
  31 #include "strv.h"
  32 #include "fileio.h"
  33 #include "login-util.h"
  34 #include "formats-util.h"
  35 #include "hostname-util.h"
  36 #include "sd-login.h"
  37
  38 _public_ int sd_pid_get_session(pid_t pid, char **session) {
  39
  40         assert_return(pid >= 0, -EINVAL);
  41         assert_return(session, -EINVAL);
  42
  43         return cg_pid_get_session(pid, session);
  44 }
  45
  46 _public_ int sd_pid_get_unit(pid_t pid, char **unit) {
  47
  48         assert_return(pid >= 0, -EINVAL);
  49         assert_return(unit, -EINVAL);
  50
  51         return cg_pid_get_unit(pid, unit);
  52 }
  53
  54 _public_ int sd_pid_get_user_unit(pid_t pid, char **unit) {
  55
  56         assert_return(pid >= 0, -EINVAL);
  57         assert_return(unit, -EINVAL);
  58
  59         return cg_pid_get_user_unit(pid, unit);
  60 }
  61
  62 _public_ int sd_pid_get_machine_name(pid_t pid, char **name) {
  63
  64         assert_return(pid >= 0, -EINVAL);
  65         assert_return(name, -EINVAL);
  66
  67         return cg_pid_get_machine_name(pid, name);
  68 }
  69
  70 _public_ int sd_pid_get_slice(pid_t pid, char **slice) {
  71
  72         assert_return(pid >= 0, -EINVAL);
  73         assert_return(slice, -EINVAL);
  74
  75         return cg_pid_get_slice(pid, slice);
  76 }
  77
  78 _public_ int sd_pid_get_user_slice(pid_t pid, char **slice) {
  79
  80         assert_return(pid >= 0, -EINVAL);
  81         assert_return(slice, -EINVAL);
  82
  83         return cg_pid_get_user_slice(pid, slice);
  84 }
  85
  86 _public_ int sd_pid_get_owner_uid(pid_t pid, uid_t *uid) {
  87
  88         assert_return(pid >= 0, -EINVAL);
  89         assert_return(uid, -EINVAL);
  90
  91         return cg_pid_get_owner_uid(pid, uid);
  92 }
  93
  94 _public_ int sd_peer_get_session(int fd, char **session) {
  95         struct ucred ucred = {};
  96         int r;
  97
  98         assert_return(fd >= 0, -EBADF);
  99         assert_return(session, -EINVAL);
 100
 101         r = getpeercred(fd, &ucred);
 102         if (r < 0)
 103                 return r;
 104
 105         return cg_pid_get_session(ucred.pid, session);
 106 }
 107
 108 _public_ int sd_peer_get_owner_uid(int fd, uid_t *uid) {
 109         struct ucred ucred;
 110         int r;
 111
 112         assert_return(fd >= 0, -EBADF);
 113         assert_return(uid, -EINVAL);
 114
 115         r = getpeercred(fd, &ucred);
 116         if (r < 0)
 117                 return r;
 118
 119         return cg_pid_get_owner_uid(ucred.pid, uid);
 120 }
 121
 122 _public_ int sd_peer_get_unit(int fd, char **unit) {
 123         struct ucred ucred;
 124         int r;
 125
 126         assert_return(fd >= 0, -EBADF);
 127         assert_return(unit, -EINVAL);
 128
 129         r = getpeercred(fd, &ucred);
 130         if (r < 0)
 131                 return r;
 132
 133         return cg_pid_get_unit(ucred.pid, unit);
 134 }
 135
 136 _public_ int sd_peer_get_user_unit(int fd, char **unit) {
 137         struct ucred ucred;
 138         int r;
 139
 140         assert_return(fd >= 0, -EBADF);
 141         assert_return(unit, -EINVAL);
 142
 143         r = getpeercred(fd, &ucred);
 144         if (r < 0)
 145                 return r;
 146
 147         return cg_pid_get_user_unit(ucred.pid, unit);
 148 }
 149
 150 _public_ int sd_peer_get_machine_name(int fd, char **machine) {
 151         struct ucred ucred;
 152         int r;
 153
 154         assert_return(fd >= 0, -EBADF);
 155         assert_return(machine, -EINVAL);
 156
 157         r = getpeercred(fd, &ucred);
 158         if (r < 0)
 159                 return r;
 160
 161         return cg_pid_get_machine_name(ucred.pid, machine);
 162 }
 163
 164 _public_ int sd_peer_get_slice(int fd, char **slice) {
 165         struct ucred ucred;
 166         int r;
 167
 168         assert_return(fd >= 0, -EBADF);
 169         assert_return(slice, -EINVAL);
 170
 171         r = getpeercred(fd, &ucred);
 172         if (r < 0)
 173                 return r;
 174
 175         return cg_pid_get_slice(ucred.pid, slice);
 176 }
 177
 178 _public_ int sd_peer_get_user_slice(int fd, char **slice) {
 179         struct ucred ucred;
 180         int r;
 181
 182         assert_return(fd >= 0, -EBADF);
 183         assert_return(slice, -EINVAL);
 184
 185         r = getpeercred(fd, &ucred);
 186         if (r < 0)
 187                 return r;
 188
 189         return cg_pid_get_user_slice(ucred.pid, slice);
 190 }
 191
 192 static int file_of_uid(uid_t uid, char **p) {
 193         assert(p);
 194
 195         if (asprintf(p, "/run/systemd/users/" UID_FMT, uid) < 0)
 196                 return -ENOMEM;
 197
 198         return 0;
 199 }
 200
 201 _public_ int sd_uid_get_state(uid_t uid, char**state) {
 202         _cleanup_free_ char *p = NULL;
 203         char *s = NULL;
 204         int r;
 205
 206         assert_return(state, -EINVAL);
 207
 208         r = file_of_uid(uid, &p);
 209         if (r < 0)
 210                 return r;
 211
 212         r = parse_env_file(p, NEWLINE, "STATE", &s, NULL);
 213         if (r == -ENOENT) {
 214                 free(s);
 215                 s = strdup("offline");
 216                 if (!s)
 217                         return -ENOMEM;
 218
 219         } else if (r < 0) {
 220                 free(s);
 221                 return r;
 222         } else if (!s)
 223                 return -EIO;
 224
 225         *state = s;
 226         return 0;
 227 }
 228
 229 _public_ int sd_uid_get_display(uid_t uid, char **session) {
 230         _cleanup_free_ char *p = NULL, *s = NULL;
 231         int r;
 232
 233         assert_return(session, -EINVAL);
 234
 235         r = file_of_uid(uid, &p);
 236         if (r < 0)
 237                 return r;
 238
 239         r = parse_env_file(p, NEWLINE, "DISPLAY", &s, NULL);
 240         if (r < 0)
 241                 return r;
 242
 243         if (isempty(s))
 244                 return -ENOENT;
 245
 246         *session = s;
 247         s = NULL;
 248
 249         return 0;
 250 }
 251
 252 _public_ int sd_uid_is_on_seat(uid_t uid, int require_active, const char *seat) {
 253         _cleanup_free_ char *t = NULL, *s = NULL, *p = NULL;
 254         size_t l;
 255         int r;
 256         const char *word, *variable, *state;
 257
 258         assert_return(seat, -EINVAL);
 259
 260         variable = require_active ? "ACTIVE_UID" : "UIDS";
 261
 262         p = strappend("/run/systemd/seats/", seat);
 263         if (!p)
 264                 return -ENOMEM;
 265
 266         r = parse_env_file(p, NEWLINE, variable, &s, NULL);
 267
 268         if (r < 0)
 269                 return r;
 270
 271         if (!s)
 272                 return -EIO;
 273
 274         if (asprintf(&t, UID_FMT, uid) < 0)
 275                 return -ENOMEM;
 276
 277         FOREACH_WORD(word, l, s, state) {
 278                 if (strneq(t, word, l))
 279                         return 1;
 280         }
 281
 282         return 0;
 283 }
 284
 285 static int uid_get_array(uid_t uid, const char *variable, char ***array) {
 286         _cleanup_free_ char *p = NULL, *s = NULL;
 287         char **a;
 288         int r;
 289
 290         r = file_of_uid(uid, &p);
 291         if (r < 0)
 292                 return r;
 293
 294         r = parse_env_file(p, NEWLINE,
 295                            variable, &s,
 296                            NULL);
 297         if (r < 0) {
 298                 if (r == -ENOENT) {
 299                         if (array)
 300                                 *array = NULL;
 301                         return 0;
 302                 }
 303
 304                 return r;
 305         }
 306
 307         if (!s) {
 308                 if (array)
 309                         *array = NULL;
 310                 return 0;
 311         }
 312
 313         a = strv_split(s, " ");
 314
 315         if (!a)
 316                 return -ENOMEM;
 317
 318         strv_uniq(a);
 319         r = strv_length(a);
 320
 321         if (array)
 322                 *array = a;
 323         else
 324                 strv_free(a);
 325
 326         return r;
 327 }
 328
 329 _public_ int sd_uid_get_sessions(uid_t uid, int require_active, char ***sessions) {
 330         return uid_get_array(
 331                         uid,
 332                         require_active == 0 ? "ONLINE_SESSIONS" :
 333                         require_active > 0  ? "ACTIVE_SESSIONS" :
 334                                               "SESSIONS",
 335                         sessions);
 336 }
 337
 338 _public_ int sd_uid_get_seats(uid_t uid, int require_active, char ***seats) {
 339         return uid_get_array(
 340                         uid,
 341                         require_active == 0 ? "ONLINE_SEATS" :
 342                         require_active > 0  ? "ACTIVE_SEATS" :
 343                                               "SEATS",
 344                         seats);
 345 }
 346
 347 static int file_of_session(const char *session, char **_p) {
 348         char *p;
 349         int r;
 350
 351         assert(_p);
 352
 353         if (session) {
 354                 if (!session_id_valid(session))
 355                         return -EINVAL;
 356
 357                 p = strappend("/run/systemd/sessions/", session);
 358         } else {
 359                 _cleanup_free_ char *buf = NULL;
 360
 361                 r = sd_pid_get_session(0, &buf);
 362                 if (r < 0)
 363                         return r;
 364
 365                 p = strappend("/run/systemd/sessions/", buf);
 366         }
 367
 368         if (!p)
 369                 return -ENOMEM;
 370
 371         *_p = p;
 372         return 0;
 373 }
 374
 375 _public_ int sd_session_is_active(const char *session) {
 376         int r;
 377         _cleanup_free_ char *p = NULL, *s = NULL;
 378
 379         r = file_of_session(session, &p);
 380         if (r < 0)
 381                 return r;
 382
 383         r = parse_env_file(p, NEWLINE, "ACTIVE", &s, NULL);
 384         if (r < 0)
 385                 return r;
 386
 387         if (!s)
 388                 return -EIO;
 389
 390         return parse_boolean(s);
 391 }
 392
 393 _public_ int sd_session_is_remote(const char *session) {
 394         int r;
 395         _cleanup_free_ char *p = NULL, *s = NULL;
 396
 397         r = file_of_session(session, &p);
 398         if (r < 0)
 399                 return r;
 400
 401         r = parse_env_file(p, NEWLINE, "REMOTE", &s, NULL);
 402         if (r < 0)
 403                 return r;
 404
 405         if (!s)
 406                 return -EIO;
 407
 408         return parse_boolean(s);
 409 }
 410
 411 _public_ int sd_session_get_state(const char *session, char **state) {
 412         _cleanup_free_ char *p = NULL, *s = NULL;
 413         int r;
 414
 415         assert_return(state, -EINVAL);
 416
 417         r = file_of_session(session, &p);
 418         if (r < 0)
 419                 return r;
 420
 421         r = parse_env_file(p, NEWLINE, "STATE", &s, NULL);
 422         if (r < 0)
 423                 return r;
 424         else if (!s)
 425                 return -EIO;
 426
 427         *state = s;
 428         s = NULL;
 429
 430         return 0;
 431 }
 432
 433 _public_ int sd_session_get_uid(const char *session, uid_t *uid) {
 434         int r;
 435         _cleanup_free_ char *p = NULL, *s = NULL;
 436
 437         assert_return(uid, -EINVAL);
 438
 439         r = file_of_session(session, &p);
 440         if (r < 0)
 441                 return r;
 442
 443         r = parse_env_file(p, NEWLINE, "UID", &s, NULL);
 444         if (r < 0)
 445                 return r;
 446
 447         if (!s)
 448                 return -EIO;
 449
 450         return parse_uid(s, uid);
 451 }
 452
 453 static int session_get_string(const char *session, const char *field, char **value) {
 454         _cleanup_free_ char *p = NULL, *s = NULL;
 455         int r;
 456
 457         assert_return(value, -EINVAL);
 458
 459         r = file_of_session(session, &p);
 460         if (r < 0)
 461                 return r;
 462
 463         r = parse_env_file(p, NEWLINE, field, &s, NULL);
 464         if (r < 0)
 465                 return r;
 466
 467         if (isempty(s))
 468                 return -ENOENT;
 469
 470         *value = s;
 471         s = NULL;
 472         return 0;
 473 }
 474
 475 _public_ int sd_session_get_seat(const char *session, char **seat) {
 476         return session_get_string(session, "SEAT", seat);
 477 }
 478
 479 _public_ int sd_session_get_tty(const char *session, char **tty) {
 480         return session_get_string(session, "TTY", tty);
 481 }
 482
 483 _public_ int sd_session_get_vt(const char *session, unsigned *vtnr) {
 484         _cleanup_free_ char *vtnr_string = NULL;
 485         unsigned u;
 486         int r;
 487
 488         r = session_get_string(session, "VTNR", &vtnr_string);
 489         if (r < 0)
 490                 return r;
 491
 492         r = safe_atou(vtnr_string, &u);
 493         if (r < 0)
 494                 return r;
 495
 496         *vtnr = u;
 497         return 0;
 498 }
 499
 500 _public_ int sd_session_get_service(const char *session, char **service) {
 501         return session_get_string(session, "SERVICE", service);
 502 }
 503
 504 _public_ int sd_session_get_type(const char *session, char **type) {
 505         return session_get_string(session, "TYPE", type);
 506 }
 507
 508 _public_ int sd_session_get_class(const char *session, char **class) {
 509         return session_get_string(session, "CLASS", class);
 510 }
 511
 512 _public_ int sd_session_get_desktop(const char *session, char **desktop) {
 513         _cleanup_free_ char *escaped = NULL;
 514         char *t;
 515         int r;
 516
 517         assert_return(desktop, -EINVAL);
 518
 519         r = session_get_string(session, "DESKTOP", &escaped);
 520         if (r < 0)
 521                 return r;
 522
 523         r = cunescape(escaped, 0, &t);
 524         if (r < 0)
 525                 return r;
 526
 527         *desktop = t;
 528         return 0;
 529 }
 530
 531 _public_ int sd_session_get_display(const char *session, char **display) {
 532         return session_get_string(session, "DISPLAY", display);
 533 }
 534
 535 _public_ int sd_session_get_remote_user(const char *session, char **remote_user) {
 536         return session_get_string(session, "REMOTE_USER", remote_user);
 537 }
 538
 539 _public_ int sd_session_get_remote_host(const char *session, char **remote_host) {
 540         return session_get_string(session, "REMOTE_HOST", remote_host);
 541 }
 542
 543 static int file_of_seat(const char *seat, char **_p) {
 544         char *p;
 545         int r;
 546
 547         assert(_p);
 548
 549         if (seat)
 550                 p = strappend("/run/systemd/seats/", seat);
 551         else {
 552                 _cleanup_free_ char *buf = NULL;
 553
 554                 r = sd_session_get_seat(NULL, &buf);
 555                 if (r < 0)
 556                         return r;
 557
 558                 p = strappend("/run/systemd/seats/", buf);
 559         }
 560
 561         if (!p)
 562                 return -ENOMEM;
 563
 564         *_p = p;
 565         p = NULL;
 566         return 0;
 567 }
 568
 569 _public_ int sd_seat_get_active(const char *seat, char **session, uid_t *uid) {
 570         _cleanup_free_ char *p = NULL, *s = NULL, *t = NULL;
 571         int r;
 572
 573         assert_return(session || uid, -EINVAL);
 574
 575         r = file_of_seat(seat, &p);
 576         if (r < 0)
 577                 return r;
 578
 579         r = parse_env_file(p, NEWLINE,
 580                            "ACTIVE", &s,
 581                            "ACTIVE_UID", &t,
 582                            NULL);
 583         if (r < 0)
 584                 return r;
 585
 586         if (session && !s)
 587                 return -ENOENT;
 588
 589         if (uid && !t)
 590                 return -ENOENT;
 591
 592         if (uid && t) {
 593                 r = parse_uid(t, uid);
 594                 if (r < 0)
 595                         return r;
 596         }
 597
 598         if (session && s) {
 599                 *session = s;
 600                 s = NULL;
 601         }
 602
 603         return 0;
 604 }
 605
 606 _public_ int sd_seat_get_sessions(const char *seat, char ***sessions, uid_t **uids, unsigned *n_uids) {
 607         _cleanup_free_ char *p = NULL, *s = NULL, *t = NULL;
 608         _cleanup_strv_free_ char **a = NULL;
 609         _cleanup_free_ uid_t *b = NULL;
 610         unsigned n = 0;
 611         int r;
 612
 613         r = file_of_seat(seat, &p);
 614         if (r < 0)
 615                 return r;
 616
 617         r = parse_env_file(p, NEWLINE,
 618                            "SESSIONS", &s,
 619                            "ACTIVE_SESSIONS", &t,
 620                            NULL);
 621
 622         if (r < 0)
 623                 return r;
 624
 625         if (s) {
 626                 a = strv_split(s, " ");
 627                 if (!a)
 628                         return -ENOMEM;
 629         }
 630
 631         if (uids && t) {
 632                 const char *word, *state;
 633                 size_t l;
 634
 635                 FOREACH_WORD(word, l, t, state)
 636                         n++;
 637
 638                 if (n > 0) {
 639                         unsigned i = 0;
 640
 641                         b = new(uid_t, n);
 642                         if (!b)
 643                                 return -ENOMEM;
 644
 645                         FOREACH_WORD(word, l, t, state) {
 646                                 _cleanup_free_ char *k = NULL;
 647
 648                                 k = strndup(word, l);
 649                                 if (!k)
 650                                         return -ENOMEM;
 651
 652                                 r = parse_uid(k, b + i);
 653
 654                                 if (r < 0)
 655                                         continue;
 656
 657                                 i++;
 658                         }
 659                 }
 660         }
 661
 662         r = strv_length(a);
 663
 664         if (sessions) {
 665                 *sessions = a;
 666                 a = NULL;
 667         }
 668
 669         if (uids) {
 670                 *uids = b;
 671                 b = NULL;
 672         }
 673
 674         if (n_uids)
 675                 *n_uids = n;
 676
 677         return r;
 678 }
 679
 680 static int seat_get_can(const char *seat, const char *variable) {
 681         _cleanup_free_ char *p = NULL, *s = NULL;
 682         int r;
 683
 684         assert_return(variable, -EINVAL);
 685
 686         r = file_of_seat(seat, &p);
 687         if (r < 0)
 688                 return r;
 689
 690         r = parse_env_file(p, NEWLINE,
 691                            variable, &s,
 692                            NULL);
 693         if (r < 0)
 694                 return r;
 695         if (!s)
 696                 return 0;
 697
 698         return parse_boolean(s);
 699 }
 700
 701 _public_ int sd_seat_can_multi_session(const char *seat) {
 702         return seat_get_can(seat, "CAN_MULTI_SESSION");
 703 }
 704
 705 _public_ int sd_seat_can_tty(const char *seat) {
 706         return seat_get_can(seat, "CAN_TTY");
 707 }
 708
 709 _public_ int sd_seat_can_graphical(const char *seat) {
 710         return seat_get_can(seat, "CAN_GRAPHICAL");
 711 }
 712
 713 _public_ int sd_get_seats(char ***seats) {
 714         return get_files_in_directory("/run/systemd/seats/", seats);
 715 }
 716
 717 _public_ int sd_get_sessions(char ***sessions) {
 718         return get_files_in_directory("/run/systemd/sessions/", sessions);
 719 }
 720
 721 _public_ int sd_get_uids(uid_t **users) {
 722         _cleanup_closedir_ DIR *d;
 723         int r = 0;
 724         unsigned n = 0;
 725         _cleanup_free_ uid_t *l = NULL;
 726
 727         d = opendir("/run/systemd/users/");
 728         if (!d)
 729                 return -errno;
 730
 731         for (;;) {
 732                 struct dirent *de;
 733                 int k;
 734                 uid_t uid;
 735
 736                 errno = 0;
 737                 de = readdir(d);
 738                 if (!de && errno != 0)
 739                         return -errno;
 740
 741                 if (!de)
 742                         break;
 743
 744                 dirent_ensure_type(d, de);
 745
 746                 if (!dirent_is_file(de))
 747                         continue;
 748
 749                 k = parse_uid(de->d_name, &uid);
 750                 if (k < 0)
 751                         continue;
 752
 753                 if (users) {
 754                         if ((unsigned) r >= n) {
 755                                 uid_t *t;
 756
 757                                 n = MAX(16, 2*r);
 758                                 t = realloc(l, sizeof(uid_t) * n);
 759                                 if (!t)
 760                                         return -ENOMEM;
 761
 762                                 l = t;
 763                         }
 764
 765                         assert((unsigned) r < n);
 766                         l[r++] = uid;
 767                 } else
 768                         r++;
 769         }
 770
 771         if (users) {
 772                 *users = l;
 773                 l = NULL;
 774         }
 775
 776         return r;
 777 }
 778
 779 _public_ int sd_get_machine_names(char ***machines) {
 780         char **l = NULL, **a, **b;
 781         int r;
 782
 783         assert_return(machines, -EINVAL);
 784
 785         r = get_files_in_directory("/run/systemd/machines/", &l);
 786         if (r < 0)
 787                 return r;
 788
 789         if (l) {
 790                 r = 0;
 791
 792                 /* Filter out the unit: symlinks */
 793                 for (a = l, b = l; *a; a++) {
 794                         if (startswith(*a, "unit:"))
 795                                 free(*a);
 796                         else {
 797                                 *b = *a;
 798                                 b++;
 799                                 r++;
 800                         }
 801                 }
 802
 803                 *b = NULL;
 804         }
 805
 806         *machines = l;
 807         return r;
 808 }
 809
 810 _public_ int sd_machine_get_class(const char *machine, char **class) {
 811         _cleanup_free_ char *c = NULL;
 812         const char *p;
 813         int r;
 814
 815         assert_return(machine_name_is_valid(machine), -EINVAL);
 816         assert_return(class, -EINVAL);
 817
 818         p = strjoina("/run/systemd/machines/", machine);
 819         r = parse_env_file(p, NEWLINE, "CLASS", &c, NULL);
 820         if (r < 0)
 821                 return r;
 822         if (!c)
 823                 return -EIO;
 824
 825         *class = c;
 826         c = NULL;
 827
 828         return 0;
 829 }
 830
 831 _public_ int sd_machine_get_ifindices(const char *machine, int **ifindices) {
 832         _cleanup_free_ char *netif = NULL;
 833         size_t l, allocated = 0, nr = 0;
 834         int *ni = NULL;
 835         const char *p, *word, *state;
 836         int r;
 837
 838         assert_return(machine_name_is_valid(machine), -EINVAL);
 839         assert_return(ifindices, -EINVAL);
 840
 841         p = strjoina("/run/systemd/machines/", machine);
 842         r = parse_env_file(p, NEWLINE, "NETIF", &netif, NULL);
 843         if (r < 0)
 844                 return r;
 845         if (!netif) {
 846                 *ifindices = NULL;
 847                 return 0;
 848         }
 849
 850         FOREACH_WORD(word, l, netif, state) {
 851                 char buf[l+1];
 852                 int ifi;
 853
 854                 *(char*) (mempcpy(buf, word, l)) = 0;
 855
 856                 if (safe_atoi(buf, &ifi) < 0)
 857                         continue;
 858                 if (ifi <= 0)
 859                         continue;
 860
 861                 if (!GREEDY_REALLOC(ni, allocated, nr+1)) {
 862                         free(ni);
 863                         return -ENOMEM;
 864                 }
 865
 866                 ni[nr++] = ifi;
 867         }
 868
 869         *ifindices = ni;
 870         return nr;
 871 }
 872
 873 static inline int MONITOR_TO_FD(sd_login_monitor *m) {
 874         return (int) (unsigned long) m - 1;
 875 }
 876
 877 static inline sd_login_monitor* FD_TO_MONITOR(int fd) {
 878         return (sd_login_monitor*) (unsigned long) (fd + 1);
 879 }
 880
 881 _public_ int sd_login_monitor_new(const char *category, sd_login_monitor **m) {
 882         int fd, k;
 883         bool good = false;
 884
 885         assert_return(m, -EINVAL);
 886
 887         fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
 888         if (fd < 0)
 889                 return -errno;
 890
 891         if (!category || streq(category, "seat")) {
 892                 k = inotify_add_watch(fd, "/run/systemd/seats/", IN_MOVED_TO|IN_DELETE);
 893                 if (k < 0) {
 894                         safe_close(fd);
 895                         return -errno;
 896                 }
 897
 898                 good = true;
 899         }
 900
 901         if (!category || streq(category, "session")) {
 902                 k = inotify_add_watch(fd, "/run/systemd/sessions/", IN_MOVED_TO|IN_DELETE);
 903                 if (k < 0) {
 904                         safe_close(fd);
 905                         return -errno;
 906                 }
 907
 908                 good = true;
 909         }
 910
 911         if (!category || streq(category, "uid")) {
 912                 k = inotify_add_watch(fd, "/run/systemd/users/", IN_MOVED_TO|IN_DELETE);
 913                 if (k < 0) {
 914                         safe_close(fd);
 915                         return -errno;
 916                 }
 917
 918                 good = true;
 919         }
 920
 921         if (!category || streq(category, "machine")) {
 922                 k = inotify_add_watch(fd, "/run/systemd/machines/", IN_MOVED_TO|IN_DELETE);
 923                 if (k < 0) {
 924                         safe_close(fd);
 925                         return -errno;
 926                 }
 927
 928                 good = true;
 929         }
 930
 931         if (!good) {
 932                 close_nointr(fd);
 933                 return -EINVAL;
 934         }
 935
 936         *m = FD_TO_MONITOR(fd);
 937         return 0;
 938 }
 939
 940 _public_ sd_login_monitor* sd_login_monitor_unref(sd_login_monitor *m) {
 941         int fd;
 942
 943         assert_return(m, NULL);
 944
 945         fd = MONITOR_TO_FD(m);
 946         close_nointr(fd);
 947
 948         return NULL;
 949 }
 950
 951 _public_ int sd_login_monitor_flush(sd_login_monitor *m) {
 952
 953         assert_return(m, -EINVAL);
 954
 955         return flush_fd(MONITOR_TO_FD(m));
 956 }
 957
 958 _public_ int sd_login_monitor_get_fd(sd_login_monitor *m) {
 959
 960         assert_return(m, -EINVAL);
 961
 962         return MONITOR_TO_FD(m);
 963 }
 964
 965 _public_ int sd_login_monitor_get_events(sd_login_monitor *m) {
 966
 967         assert_return(m, -EINVAL);
 968
 969         /* For now we will only return POLLIN here, since we don't
 970          * need anything else ever for inotify.  However, let's have
 971          * this API to keep our options open should we later on need
 972          * it. */
 973         return POLLIN;
 974 }
 975
 976 _public_ int sd_login_monitor_get_timeout(sd_login_monitor *m, uint64_t *timeout_usec) {
 977
 978         assert_return(m, -EINVAL);
 979         assert_return(timeout_usec, -EINVAL);
 980
 981         /* For now we will only return (uint64_t) -1, since we don't
 982          * need any timeout. However, let's have this API to keep our
 983          * options open should we later on need it. */
 984         *timeout_usec = (uint64_t) -1;
 985         return 0;
 986 }