src/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 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_service(pid_t pid, char **service) {
 125         int r;
 126         char *cgroup, *p;
 127
 128         if (!service)
 129                 return -EINVAL;
 130
 131         r = pid_get_cgroup(pid, NULL, &cgroup);
 132         if (r < 0)
 133                 return r;
 134
 135         if (!startswith(cgroup, "/system/")) {
 136                 free(cgroup);
 137                 return -ENOENT;
 138         }
 139
 140         p = cgroup + 8;
 141         p = strndup(p, strcspn(p, "/"));
 142         free(cgroup);
 143
 144         if (!p)
 145                 return -ENOMEM;
 146
 147         *service = p;
 148         return 0;
 149 }
 150
 151 _public_ int sd_pid_get_owner_uid(pid_t pid, uid_t *uid) {
 152         int r;
 153         char *root, *cgroup, *p, *cc;
 154         struct stat st;
 155
 156         if (!uid)
 157                 return -EINVAL;
 158
 159         r = pid_get_cgroup(pid, &root, &cgroup);
 160         if (r < 0)
 161                 return r;
 162
 163         if (!startswith(cgroup, "/user/")) {
 164                 free(cgroup);
 165                 free(root);
 166                 return -ENOENT;
 167         }
 168
 169         p = strchr(cgroup + 6, '/');
 170         if (!p) {
 171                 free(cgroup);
 172                 return -ENOENT;
 173         }
 174
 175         p++;
 176         p += strcspn(p, "/");
 177         *p = 0;
 178
 179         r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, root, cgroup, &cc);
 180         free(root);
 181         free(cgroup);
 182
 183         if (r < 0)
 184                 return -ENOMEM;
 185
 186         r = lstat(cc, &st);
 187         free(cc);
 188
 189         if (r < 0)
 190                 return -errno;
 191
 192         if (!S_ISDIR(st.st_mode))
 193                 return -ENOTDIR;
 194
 195         *uid = st.st_uid;
 196         return 0;
 197 }
 198
 199 _public_ int sd_uid_get_state(uid_t uid, char**state) {
 200         char *p, *s = NULL;
 201         int r;
 202
 203         if (!state)
 204                 return -EINVAL;
 205
 206         if (asprintf(&p, "/run/systemd/users/%lu", (unsigned long) uid) < 0)
 207                 return -ENOMEM;
 208
 209         r = parse_env_file(p, NEWLINE, "STATE", &s, NULL);
 210         free(p);
 211
 212         if (r == -ENOENT) {
 213                 free(s);
 214                 s = strdup("offline");
 215                 if (!s)
 216                         return -ENOMEM;
 217
 218                 *state = s;
 219                 return 0;
 220         } else if (r < 0) {
 221                 free(s);
 222                 return r;
 223         } else if (!s)
 224                 return -EIO;
 225
 226         *state = s;
 227         return 0;
 228 }
 229
 230 _public_ int sd_uid_is_on_seat(uid_t uid, int require_active, const char *seat) {
 231         char *p, *w, *t, *state, *s = NULL;
 232         size_t l;
 233         int r;
 234         const char *variable;
 235
 236         if (!seat)
 237                 return -EINVAL;
 238
 239         variable = require_active ? "ACTIVE_UID" : "UIDS";
 240
 241         p = strappend("/run/systemd/seats/", seat);
 242         if (!p)
 243                 return -ENOMEM;
 244
 245         r = parse_env_file(p, NEWLINE, variable, &s, NULL);
 246         free(p);
 247
 248         if (r < 0) {
 249                 free(s);
 250                 return r;
 251         }
 252
 253         if (!s)
 254                 return -EIO;
 255
 256         if (asprintf(&t, "%lu", (unsigned long) uid) < 0) {
 257                 free(s);
 258                 return -ENOMEM;
 259         }
 260
 261         FOREACH_WORD(w, l, s, state) {
 262                 if (strncmp(t, w, l) == 0) {
 263                         free(s);
 264                         free(t);
 265
 266                         return 1;
 267                 }
 268         }
 269
 270         free(s);
 271         free(t);
 272
 273         return 0;
 274 }
 275
 276 static int uid_get_array(uid_t uid, const char *variable, char ***array) {
 277         char *p, *s = NULL;
 278         char **a;
 279         int r;
 280
 281         if (asprintf(&p, "/run/systemd/users/%lu", (unsigned long) uid) < 0)
 282                 return -ENOMEM;
 283
 284         r = parse_env_file(p, NEWLINE,
 285                            variable, &s,
 286                            NULL);
 287         free(p);
 288
 289         if (r < 0) {
 290                 free(s);
 291
 292                 if (r == -ENOENT) {
 293                         if (array)
 294                                 *array = NULL;
 295                         return 0;
 296                 }
 297
 298                 return r;
 299         }
 300
 301         if (!s) {
 302                 if (array)
 303                         *array = NULL;
 304                 return 0;
 305         }
 306
 307         a = strv_split(s, " ");
 308         free(s);
 309
 310         if (!a)
 311                 return -ENOMEM;
 312
 313         strv_uniq(a);
 314         r = strv_length(a);
 315
 316         if (array)
 317                 *array = a;
 318         else
 319                 strv_free(a);
 320
 321         return r;
 322 }
 323
 324 _public_ int sd_uid_get_sessions(uid_t uid, int require_active, char ***sessions) {
 325         return uid_get_array(uid, require_active ? "ACTIVE_SESSIONS" : "SESSIONS", sessions);
 326 }
 327
 328 _public_ int sd_uid_get_seats(uid_t uid, int require_active, char ***seats) {
 329         return uid_get_array(uid, require_active ? "ACTIVE_SEATS" : "SEATS", seats);
 330 }
 331
 332 _public_ int sd_session_is_active(const char *session) {
 333         int r;
 334         char *p, *s = NULL;
 335
 336         if (!session)
 337                 return -EINVAL;
 338
 339         p = strappend("/run/systemd/sessions/", session);
 340         if (!p)
 341                 return -ENOMEM;
 342
 343         r = parse_env_file(p, NEWLINE, "ACTIVE", &s, NULL);
 344         free(p);
 345
 346         if (r < 0) {
 347                 free(s);
 348                 return r;
 349         }
 350
 351         if (!s)
 352                 return -EIO;
 353
 354         r = parse_boolean(s);
 355         free(s);
 356
 357         return r;
 358 }
 359
 360 _public_ int sd_session_get_uid(const char *session, uid_t *uid) {
 361         int r;
 362         char *p, *s = NULL;
 363
 364         if (!session)
 365                 return -EINVAL;
 366         if (!uid)
 367                 return -EINVAL;
 368
 369         p = strappend("/run/systemd/sessions/", session);
 370         if (!p)
 371                 return -ENOMEM;
 372
 373         r = parse_env_file(p, NEWLINE, "UID", &s, NULL);
 374         free(p);
 375
 376         if (r < 0) {
 377                 free(s);
 378                 return r;
 379         }
 380
 381         if (!s)
 382                 return -EIO;
 383
 384         r = parse_uid(s, uid);
 385         free(s);
 386
 387         return r;
 388 }
 389
 390 _public_ int sd_session_get_seat(const char *session, char **seat) {
 391         char *p, *s = NULL;
 392         int r;
 393
 394         if (!session)
 395                 return -EINVAL;
 396         if (!seat)
 397                 return -EINVAL;
 398
 399         p = strappend("/run/systemd/sessions/", session);
 400         if (!p)
 401                 return -ENOMEM;
 402
 403         r = parse_env_file(p, NEWLINE, "SEAT", &s, NULL);
 404         free(p);
 405
 406         if (r < 0) {
 407                 free(s);
 408                 return r;
 409         }
 410
 411         if (isempty(s))
 412                 return -ENOENT;
 413
 414         *seat = s;
 415         return 0;
 416 }
 417
 418 _public_ int sd_seat_get_active(const char *seat, char **session, uid_t *uid) {
 419         char *p, *s = NULL, *t = NULL;
 420         int r;
 421
 422         if (!seat)
 423                 return -EINVAL;
 424         if (!session && !uid)
 425                 return -EINVAL;
 426
 427         p = strappend("/run/systemd/seats/", seat);
 428         if (!p)
 429                 return -ENOMEM;
 430
 431         r = parse_env_file(p, NEWLINE,
 432                            "ACTIVE", &s,
 433                            "ACTIVE_UID", &t,
 434                            NULL);
 435         free(p);
 436
 437         if (r < 0) {
 438                 free(s);
 439                 free(t);
 440                 return r;
 441         }
 442
 443         if (session && !s)  {
 444                 free(t);
 445                 return -ENOENT;
 446         }
 447
 448         if (uid && !t) {
 449                 free(s);
 450                 return -ENOENT;
 451         }
 452
 453         if (uid && t) {
 454                 r = parse_uid(t, uid);
 455                 if (r < 0) {
 456                         free(t);
 457                         free(s);
 458                         return r;
 459                 }
 460         }
 461
 462         free(t);
 463
 464         if (session && s)
 465                 *session = s;
 466         else
 467                 free(s);
 468
 469         return 0;
 470 }
 471
 472 _public_ int sd_seat_get_sessions(const char *seat, char ***sessions, uid_t **uids, unsigned *n_uids) {
 473         char *p, *s = NULL, *t = NULL, **a = NULL;
 474         uid_t *b = NULL;
 475         unsigned n = 0;
 476         int r;
 477
 478         if (!seat)
 479                 return -EINVAL;
 480
 481         p = strappend("/run/systemd/seats/", seat);
 482         if (!p)
 483                 return -ENOMEM;
 484
 485         r = parse_env_file(p, NEWLINE,
 486                            "SESSIONS", &s,
 487                            "ACTIVE_SESSIONS", &t,
 488                            NULL);
 489         free(p);
 490
 491         if (r < 0) {
 492                 free(s);
 493                 free(t);
 494                 return r;
 495         }
 496
 497         if (s) {
 498                 a = strv_split(s, " ");
 499                 if (!a) {
 500                         free(s);
 501                         free(t);
 502                         return -ENOMEM;
 503                 }
 504         }
 505
 506         free(s);
 507
 508         if (uids && t) {
 509                 char *w, *state;
 510                 size_t l;
 511
 512                 FOREACH_WORD(w, l, t, state)
 513                         n++;
 514
 515                 if (n == 0)
 516                         b = NULL;
 517                 else {
 518                         unsigned i = 0;
 519
 520                         b = new(uid_t, n);
 521                         if (!b) {
 522                                 strv_free(a);
 523                                 return -ENOMEM;
 524                         }
 525
 526                         FOREACH_WORD(w, l, t, state) {
 527                                 char *k;
 528
 529                                 k = strndup(w, l);
 530                                 if (!k) {
 531                                         free(t);
 532                                         free(b);
 533                                         strv_free(a);
 534                                         return -ENOMEM;
 535                                 }
 536
 537                                 r = parse_uid(k, b + i);
 538                                 free(k);
 539                                 if (r < 0)
 540                                         continue;
 541
 542                                 i++;
 543                         }
 544                 }
 545         }
 546
 547         free(t);
 548
 549         r = strv_length(a);
 550
 551         if (sessions)
 552                 *sessions = a;
 553         else
 554                 strv_free(a);
 555
 556         if (uids)
 557                 *uids = b;
 558
 559         if (n_uids)
 560                 *n_uids = n;
 561
 562         return r;
 563 }
 564
 565 _public_ int sd_seat_can_multi_session(const char *seat) {
 566         char *p, *s = NULL;
 567         int r;
 568
 569         if (!seat)
 570                 return -EINVAL;
 571
 572         p = strappend("/run/systemd/seats/", seat);
 573         if (!p)
 574                 return -ENOMEM;
 575
 576         r = parse_env_file(p, NEWLINE,
 577                            "CAN_MULTI_SESSION", &s,
 578                            NULL);
 579         free(p);
 580
 581         if (r < 0) {
 582                 free(s);
 583                 return r;
 584         }
 585
 586         if (s) {
 587                 r = parse_boolean(s);
 588                 free(s);
 589         } else
 590                 r = 0;
 591
 592         return r;
 593 }
 594
 595 _public_ int sd_get_seats(char ***seats) {
 596         return get_files_in_directory("/run/systemd/seats/", seats);
 597 }
 598
 599 _public_ int sd_get_sessions(char ***sessions) {
 600         return get_files_in_directory("/run/systemd/sessions/", sessions);
 601 }
 602
 603 _public_ int sd_get_uids(uid_t **users) {
 604         DIR *d;
 605         int r = 0;
 606         unsigned n = 0;
 607         uid_t *l = NULL;
 608
 609         d = opendir("/run/systemd/users/");
 610         if (!d)
 611                 return -errno;
 612
 613         for (;;) {
 614                 struct dirent buffer, *de;
 615                 int k;
 616                 uid_t uid;
 617
 618                 k = readdir_r(d, &buffer, &de);
 619                 if (k != 0) {
 620                         r = -k;
 621                         goto finish;
 622                 }
 623
 624                 if (!de)
 625                         break;
 626
 627                 dirent_ensure_type(d, de);
 628
 629                 if (!dirent_is_file(de))
 630                         continue;
 631
 632                 k = parse_uid(de->d_name, &uid);
 633                 if (k < 0)
 634                         continue;
 635
 636                 if (users) {
 637                         if ((unsigned) r >= n) {
 638                                 uid_t *t;
 639
 640                                 n = MAX(16, 2*r);
 641                                 t = realloc(l, sizeof(uid_t) * n);
 642                                 if (!t) {
 643                                         r = -ENOMEM;
 644                                         goto finish;
 645                                 }
 646
 647                                 l = t;
 648                         }
 649
 650                         assert((unsigned) r < n);
 651                         l[r++] = uid;
 652                 } else
 653                         r++;
 654         }
 655
 656 finish:
 657         if (d)
 658                 closedir(d);
 659
 660         if (r >= 0) {
 661                 if (users)
 662                         *users = l;
 663         } else
 664                 free(l);
 665
 666         return r;
 667 }
 668
 669 static inline int MONITOR_TO_FD(sd_login_monitor *m) {
 670         return (int) (unsigned long) m - 1;
 671 }
 672
 673 static inline sd_login_monitor* FD_TO_MONITOR(int fd) {
 674         return (sd_login_monitor*) (unsigned long) (fd + 1);
 675 }
 676
 677 _public_ int sd_login_monitor_new(const char *category, sd_login_monitor **m) {
 678         int fd, k;
 679         bool good = false;
 680
 681         if (!m)
 682                 return -EINVAL;
 683
 684         fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
 685         if (fd < 0)
 686                 return errno;
 687
 688         if (!category || streq(category, "seat")) {
 689                 k = inotify_add_watch(fd, "/run/systemd/seats/", IN_MOVED_TO|IN_DELETE);
 690                 if (k < 0) {
 691                         close_nointr_nofail(fd);
 692                         return -errno;
 693                 }
 694
 695                 good = true;
 696         }
 697
 698         if (!category || streq(category, "session")) {
 699                 k = inotify_add_watch(fd, "/run/systemd/sessions/", IN_MOVED_TO|IN_DELETE);
 700                 if (k < 0) {
 701                         close_nointr_nofail(fd);
 702                         return -errno;
 703                 }
 704
 705                 good = true;
 706         }
 707
 708         if (!category || streq(category, "uid")) {
 709                 k = inotify_add_watch(fd, "/run/systemd/users/", IN_MOVED_TO|IN_DELETE);
 710                 if (k < 0) {
 711                         close_nointr_nofail(fd);
 712                         return -errno;
 713                 }
 714
 715                 good = true;
 716         }
 717
 718         if (!good) {
 719                 close_nointr(fd);
 720                 return -EINVAL;
 721         }
 722
 723         *m = FD_TO_MONITOR(fd);
 724         return 0;
 725 }
 726
 727 _public_ sd_login_monitor* sd_login_monitor_unref(sd_login_monitor *m) {
 728         int fd;
 729
 730         if (!m)
 731                 return NULL;
 732
 733         fd = MONITOR_TO_FD(m);
 734         close_nointr(fd);
 735
 736         return NULL;
 737 }
 738
 739 _public_ int sd_login_monitor_flush(sd_login_monitor *m) {
 740
 741         if (!m)
 742                 return -EINVAL;
 743
 744         return flush_fd(MONITOR_TO_FD(m));
 745 }
 746
 747 _public_ int sd_login_monitor_get_fd(sd_login_monitor *m) {
 748
 749         if (!m)
 750                 return -EINVAL;
 751
 752         return MONITOR_TO_FD(m);
 753 }