src/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 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 <unistd.h>
  23 #include <string.h>
  24 #include <errno.h>
  25 #include <sys/inotify.h>
  26
  27 #include "util.h"
  28 #include "cgroup-util.h"
  29 #include "macro.h"
  30 #include "sd-login.h"
  31 #include "strv.h"
  32
  33 static int pid_get_cgroup(pid_t pid, char **root, char **cgroup) {
  34         char *cg_process, *cg_init, *p;
  35         int r;
  36
  37         if (pid == 0)
  38                 pid = getpid();
  39
  40         if (pid <= 0)
  41                 return -EINVAL;
  42
  43         r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, pid, &cg_process);
  44         if (r < 0)
  45                 return r;
  46
  47         r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 1, &cg_init);
  48         if (r < 0) {
  49                 free(cg_process);
  50                 return r;
  51         }
  52
  53         if (endswith(cg_init, "/system"))
  54                 cg_init[strlen(cg_init)-7] = 0;
  55         else if (streq(cg_init, "/"))
  56                 cg_init[0] = 0;
  57
  58         if (startswith(cg_process, cg_init))
  59                 p = cg_process + strlen(cg_init);
  60         else
  61                 p = cg_process;
  62
  63         free(cg_init);
  64
  65         if (cgroup) {
  66                 char* c;
  67
  68                 c = strdup(p);
  69                 if (!c) {
  70                         free(cg_process);
  71                         return -ENOMEM;
  72                 }
  73
  74                 *cgroup = c;
  75         }
  76
  77         if (root) {
  78                 cg_process[p-cg_process] = 0;
  79                 *root = cg_process;
  80         } else
  81                 free(cg_process);
  82
  83         return 0;
  84 }
  85
  86 _public_ int sd_pid_get_session(pid_t pid, char **session) {
  87         int r;
  88         char *cgroup, *p;
  89
  90         if (!session)
  91                 return -EINVAL;
  92
  93         r = pid_get_cgroup(pid, NULL, &cgroup);
  94         if (r < 0)
  95                 return r;
  96
  97         if (!startswith(cgroup, "/user/")) {
  98                 free(cgroup);
  99                 return -ENOENT;
 100         }
 101
 102         p = strchr(cgroup + 6, '/');
 103         if (!p) {
 104                 free(cgroup);
 105                 return -ENOENT;
 106         }
 107
 108         p++;
 109         if (startswith(p, "shared/") || streq(p, "shared")) {
 110                 free(cgroup);
 111                 return -ENOENT;
 112         }
 113
 114         p = strndup(p, strcspn(p, "/"));
 115         free(cgroup);
 116
 117         if (!p)
 118                 return -ENOMEM;
 119
 120         *session = p;
 121         return 0;
 122 }
 123
 124 _public_ int sd_pid_get_owner_uid(pid_t pid, uid_t *uid) {
 125         int r;
 126         char *root, *cgroup, *p, *cc;
 127         struct stat st;
 128
 129         if (!uid)
 130                 return -EINVAL;
 131
 132         r = pid_get_cgroup(pid, &root, &cgroup);
 133         if (r < 0)
 134                 return r;
 135
 136         if (!startswith(cgroup, "/user/")) {
 137                 free(cgroup);
 138                 free(root);
 139                 return -ENOENT;
 140         }
 141
 142         p = strchr(cgroup + 6, '/');
 143         if (!p) {
 144                 free(cgroup);
 145                 return -ENOENT;
 146         }
 147
 148         p++;
 149         p += strcspn(p, "/");
 150         *p = 0;
 151
 152         r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, root, cgroup, &cc);
 153         free(root);
 154         free(cgroup);
 155
 156         if (r < 0)
 157                 return -ENOMEM;
 158
 159         r = lstat(cc, &st);
 160         free(cc);
 161
 162         if (r < 0)
 163                 return -errno;
 164
 165         if (!S_ISDIR(st.st_mode))
 166                 return -ENOTDIR;
 167
 168         *uid = st.st_uid;
 169         return 0;
 170 }
 171
 172 _public_ int sd_uid_get_state(uid_t uid, char**state) {
 173         char *p, *s = NULL;
 174         int r;
 175
 176         if (!state)
 177                 return -EINVAL;
 178
 179         if (asprintf(&p, "/run/systemd/users/%lu", (unsigned long) uid) < 0)
 180                 return -ENOMEM;
 181
 182         r = parse_env_file(p, NEWLINE, "STATE", &s, NULL);
 183         free(p);
 184
 185         if (r == -ENOENT) {
 186                 free(s);
 187                 s = strdup("offline");
 188                 if (!s)
 189                         return -ENOMEM;
 190
 191                 *state = s;
 192                 return 0;
 193         } else if (r < 0) {
 194                 free(s);
 195                 return r;
 196         } else if (!s)
 197                 return -EIO;
 198
 199         *state = s;
 200         return 0;
 201 }
 202
 203 _public_ int sd_uid_is_on_seat(uid_t uid, int require_active, const char *seat) {
 204         char *p, *w, *t, *state, *s = NULL;
 205         size_t l;
 206         int r;
 207         const char *variable;
 208
 209         if (!seat)
 210                 return -EINVAL;
 211
 212         variable = require_active ? "ACTIVE_UID" : "UIDS";
 213
 214         p = strappend("/run/systemd/seats/", seat);
 215         if (!p)
 216                 return -ENOMEM;
 217
 218         r = parse_env_file(p, NEWLINE, variable, &s, NULL);
 219         free(p);
 220
 221         if (r < 0) {
 222                 free(s);
 223                 return r;
 224         }
 225
 226         if (!s)
 227                 return -EIO;
 228
 229         if (asprintf(&t, "%lu", (unsigned long) uid) < 0) {
 230                 free(s);
 231                 return -ENOMEM;
 232         }
 233
 234         FOREACH_WORD(w, l, s, state) {
 235                 if (strncmp(t, w, l) == 0) {
 236                         free(s);
 237                         free(t);
 238
 239                         return 1;
 240                 }
 241         }
 242
 243         free(s);
 244         free(t);
 245
 246         return 0;
 247 }
 248
 249 static int uid_get_array(uid_t uid, const char *variable, char ***array) {
 250         char *p, *s = NULL;
 251         char **a;
 252         int r;
 253
 254         if (asprintf(&p, "/run/systemd/users/%lu", (unsigned long) uid) < 0)
 255                 return -ENOMEM;
 256
 257         r = parse_env_file(p, NEWLINE,
 258                            variable, &s,
 259                            NULL);
 260         free(p);
 261
 262         if (r < 0) {
 263                 free(s);
 264
 265                 if (r == -ENOENT) {
 266                         if (array)
 267                                 *array = NULL;
 268                         return 0;
 269                 }
 270
 271                 return r;
 272         }
 273
 274         if (!s) {
 275                 if (array)
 276                         *array = NULL;
 277                 return 0;
 278         }
 279
 280         a = strv_split(s, " ");
 281         free(s);
 282
 283         if (!a)
 284                 return -ENOMEM;
 285
 286         strv_uniq(a);
 287         r = strv_length(a);
 288
 289         if (array)
 290                 *array = a;
 291         else
 292                 strv_free(a);
 293
 294         return r;
 295 }
 296
 297 _public_ int sd_uid_get_sessions(uid_t uid, int require_active, char ***sessions) {
 298         return uid_get_array(uid, require_active ? "ACTIVE_SESSIONS" : "SESSIONS", sessions);
 299 }
 300
 301 _public_ int sd_uid_get_seats(uid_t uid, int require_active, char ***seats) {
 302         return uid_get_array(uid, require_active ? "ACTIVE_SEATS" : "SEATS", seats);
 303 }
 304
 305 _public_ int sd_session_is_active(const char *session) {
 306         int r;
 307         char *p, *s = NULL;
 308
 309         if (!session)
 310                 return -EINVAL;
 311
 312         p = strappend("/run/systemd/sessions/", session);
 313         if (!p)
 314                 return -ENOMEM;
 315
 316         r = parse_env_file(p, NEWLINE, "ACTIVE", &s, NULL);
 317         free(p);
 318
 319         if (r < 0) {
 320                 free(s);
 321                 return r;
 322         }
 323
 324         if (!s)
 325                 return -EIO;
 326
 327         r = parse_boolean(s);
 328         free(s);
 329
 330         return r;
 331 }
 332
 333 _public_ int sd_session_get_uid(const char *session, uid_t *uid) {
 334         int r;
 335         char *p, *s = NULL;
 336
 337         if (!session)
 338                 return -EINVAL;
 339         if (!uid)
 340                 return -EINVAL;
 341
 342         p = strappend("/run/systemd/sessions/", session);
 343         if (!p)
 344                 return -ENOMEM;
 345
 346         r = parse_env_file(p, NEWLINE, "UID", &s, NULL);
 347         free(p);
 348
 349         if (r < 0) {
 350                 free(s);
 351                 return r;
 352         }
 353
 354         if (!s)
 355                 return -EIO;
 356
 357         r = parse_uid(s, uid);
 358         free(s);
 359
 360         return r;
 361 }
 362
 363 _public_ int sd_session_get_seat(const char *session, char **seat) {
 364         char *p, *s = NULL;
 365         int r;
 366
 367         if (!session)
 368                 return -EINVAL;
 369         if (!seat)
 370                 return -EINVAL;
 371
 372         p = strappend("/run/systemd/sessions/", session);
 373         if (!p)
 374                 return -ENOMEM;
 375
 376         r = parse_env_file(p, NEWLINE, "SEAT", &s, NULL);
 377         free(p);
 378
 379         if (r < 0) {
 380                 free(s);
 381                 return r;
 382         }
 383
 384         if (isempty(s))
 385                 return -ENOENT;
 386
 387         *seat = s;
 388         return 0;
 389 }
 390
 391 _public_ int sd_seat_get_active(const char *seat, char **session, uid_t *uid) {
 392         char *p, *s = NULL, *t = NULL;
 393         int r;
 394
 395         if (!seat)
 396                 return -EINVAL;
 397         if (!session && !uid)
 398                 return -EINVAL;
 399
 400         p = strappend("/run/systemd/seats/", seat);
 401         if (!p)
 402                 return -ENOMEM;
 403
 404         r = parse_env_file(p, NEWLINE,
 405                            "ACTIVE", &s,
 406                            "ACTIVE_UID", &t,
 407                            NULL);
 408         free(p);
 409
 410         if (r < 0) {
 411                 free(s);
 412                 free(t);
 413                 return r;
 414         }
 415
 416         if (session && !s)  {
 417                 free(t);
 418                 return -ENOENT;
 419         }
 420
 421         if (uid && !t) {
 422                 free(s);
 423                 return -ENOENT;
 424         }
 425
 426         if (uid && t) {
 427                 r = parse_uid(t, uid);
 428                 if (r < 0) {
 429                         free(t);
 430                         free(s);
 431                         return r;
 432                 }
 433         }
 434
 435         free(t);
 436
 437         if (session && s)
 438                 *session = s;
 439         else
 440                 free(s);
 441
 442         return 0;
 443 }
 444
 445 _public_ int sd_seat_get_sessions(const char *seat, char ***sessions, uid_t **uids, unsigned *n_uids) {
 446         char *p, *s = NULL, *t = NULL, **a = NULL;
 447         uid_t *b = NULL;
 448         unsigned n = 0;
 449         int r;
 450
 451         if (!seat)
 452                 return -EINVAL;
 453
 454         p = strappend("/run/systemd/seats/", seat);
 455         if (!p)
 456                 return -ENOMEM;
 457
 458         r = parse_env_file(p, NEWLINE,
 459                            "SESSIONS", &s,
 460                            "ACTIVE_SESSIONS", &t,
 461                            NULL);
 462         free(p);
 463
 464         if (r < 0) {
 465                 free(s);
 466                 free(t);
 467                 return r;
 468         }
 469
 470         if (s) {
 471                 a = strv_split(s, " ");
 472                 if (!a) {
 473                         free(s);
 474                         free(t);
 475                         return -ENOMEM;
 476                 }
 477         }
 478
 479         free(s);
 480
 481         if (uids && t) {
 482                 char *w, *state;
 483                 size_t l;
 484
 485                 FOREACH_WORD(w, l, t, state)
 486                         n++;
 487
 488                 if (n == 0)
 489                         b = NULL;
 490                 else {
 491                         unsigned i = 0;
 492
 493                         b = new(uid_t, n);
 494                         if (!b) {
 495                                 strv_free(a);
 496                                 return -ENOMEM;
 497                         }
 498
 499                         FOREACH_WORD(w, l, t, state) {
 500                                 char *k;
 501
 502                                 k = strndup(w, l);
 503                                 if (!k) {
 504                                         free(t);
 505                                         free(b);
 506                                         strv_free(a);
 507                                         return -ENOMEM;
 508                                 }
 509
 510                                 r = parse_uid(k, b + i);
 511                                 free(k);
 512                                 if (r < 0)
 513                                         continue;
 514
 515                                 i++;
 516                         }
 517                 }
 518         }
 519
 520         free(t);
 521
 522         r = strv_length(a);
 523
 524         if (sessions)
 525                 *sessions = a;
 526         else
 527                 strv_free(a);
 528
 529         if (uids)
 530                 *uids = b;
 531
 532         if (n_uids)
 533                 *n_uids = n;
 534
 535         return r;
 536 }
 537
 538 _public_ int sd_seat_can_multi_session(const char *seat) {
 539         char *p, *s = NULL;
 540         int r;
 541
 542         if (!seat)
 543                 return -EINVAL;
 544
 545         p = strappend("/run/systemd/seats/", seat);
 546         if (!p)
 547                 return -ENOMEM;
 548
 549         r = parse_env_file(p, NEWLINE,
 550                            "IS_VTCONSOLE", &s,
 551                            NULL);
 552         free(p);
 553
 554         if (r < 0) {
 555                 free(s);
 556                 return r;
 557         }
 558
 559         if (s) {
 560                 r = parse_boolean(s);
 561                 free(s);
 562         } else
 563                 r = 0;
 564
 565         return r;
 566 }
 567
 568 _public_ int sd_get_seats(char ***seats) {
 569         return get_files_in_directory("/run/systemd/seats/", seats);
 570 }
 571
 572 _public_ int sd_get_sessions(char ***sessions) {
 573         return get_files_in_directory("/run/systemd/sessions/", sessions);
 574 }
 575
 576 _public_ int sd_get_uids(uid_t **users) {
 577         DIR *d;
 578         int r = 0;
 579         unsigned n = 0;
 580         uid_t *l = NULL;
 581
 582         d = opendir("/run/systemd/users/");
 583         if (!d)
 584                 return -errno;
 585
 586         for (;;) {
 587                 struct dirent buffer, *de;
 588                 int k;
 589                 uid_t uid;
 590
 591                 k = readdir_r(d, &buffer, &de);
 592                 if (k != 0) {
 593                         r = -k;
 594                         goto finish;
 595                 }
 596
 597                 if (!de)
 598                         break;
 599
 600                 dirent_ensure_type(d, de);
 601
 602                 if (!dirent_is_file(de))
 603                         continue;
 604
 605                 k = parse_uid(de->d_name, &uid);
 606                 if (k < 0)
 607                         continue;
 608
 609                 if (users) {
 610                         if ((unsigned) r >= n) {
 611                                 uid_t *t;
 612
 613                                 n = MAX(16, 2*r);
 614                                 t = realloc(l, sizeof(uid_t) * n);
 615                                 if (!t) {
 616                                         r = -ENOMEM;
 617                                         goto finish;
 618                                 }
 619
 620                                 l = t;
 621                         }
 622
 623                         assert((unsigned) r < n);
 624                         l[r++] = uid;
 625                 } else
 626                         r++;
 627         }
 628
 629 finish:
 630         if (d)
 631                 closedir(d);
 632
 633         if (r >= 0) {
 634                 if (users)
 635                         *users = l;
 636         } else
 637                 free(l);
 638
 639         return r;
 640 }
 641
 642 static inline int MONITOR_TO_FD(sd_login_monitor *m) {
 643         return (int) (unsigned long) m - 1;
 644 }
 645
 646 static inline sd_login_monitor* FD_TO_MONITOR(int fd) {
 647         return (sd_login_monitor*) (unsigned long) (fd + 1);
 648 }
 649
 650 _public_ int sd_login_monitor_new(const char *category, sd_login_monitor **m) {
 651         int fd, k;
 652         bool good = false;
 653
 654         if (!m)
 655                 return -EINVAL;
 656
 657         fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
 658         if (fd < 0)
 659                 return errno;
 660
 661         if (!category || streq(category, "seat")) {
 662                 k = inotify_add_watch(fd, "/run/systemd/seats/", IN_MOVED_TO|IN_DELETE);
 663                 if (k < 0) {
 664                         close_nointr_nofail(fd);
 665                         return -errno;
 666                 }
 667
 668                 good = true;
 669         }
 670
 671         if (!category || streq(category, "session")) {
 672                 k = inotify_add_watch(fd, "/run/systemd/sessions/", IN_MOVED_TO|IN_DELETE);
 673                 if (k < 0) {
 674                         close_nointr_nofail(fd);
 675                         return -errno;
 676                 }
 677
 678                 good = true;
 679         }
 680
 681         if (!category || streq(category, "uid")) {
 682                 k = inotify_add_watch(fd, "/run/systemd/users/", IN_MOVED_TO|IN_DELETE);
 683                 if (k < 0) {
 684                         close_nointr_nofail(fd);
 685                         return -errno;
 686                 }
 687
 688                 good = true;
 689         }
 690
 691         if (!good) {
 692                 close_nointr(fd);
 693                 return -EINVAL;
 694         }
 695
 696         *m = FD_TO_MONITOR(fd);
 697         return 0;
 698 }
 699
 700 _public_ sd_login_monitor* sd_login_monitor_unref(sd_login_monitor *m) {
 701         int fd;
 702
 703         if (!m)
 704                 return NULL;
 705
 706         fd = MONITOR_TO_FD(m);
 707         close_nointr(fd);
 708
 709         return NULL;
 710 }
 711
 712 _public_ int sd_login_monitor_flush(sd_login_monitor *m) {
 713
 714         if (!m)
 715                 return -EINVAL;
 716
 717         return flush_fd(MONITOR_TO_FD(m));
 718 }
 719
 720 _public_ int sd_login_monitor_get_fd(sd_login_monitor *m) {
 721
 722         if (!m)
 723                 return -EINVAL;
 724
 725         return MONITOR_TO_FD(m);
 726 }