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_unit(pid_t pid, char **unit) {
 125         int r;
 126         char *cgroup, *p;
 127
 128         if (!unit)
 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         *unit = 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_session_get_service(const char *session, char **service) {
 419         char *p, *s = NULL;
 420         int r;
 421
 422         if (!session)
 423                 return -EINVAL;
 424         if (!service)
 425                 return -EINVAL;
 426
 427         p = strappend("/run/systemd/sessions/", session);
 428         if (!p)
 429                 return -ENOMEM;
 430
 431         r = parse_env_file(p, NEWLINE, "SERVICE", &s, NULL);
 432         free(p);
 433
 434         if (r < 0) {
 435                 free(s);
 436                 return r;
 437         }
 438
 439         if (isempty(s))
 440                 return -ENOENT;
 441
 442         *service = s;
 443         return 0;
 444 }
 445
 446 _public_ int sd_seat_get_active(const char *seat, char **session, uid_t *uid) {
 447         char *p, *s = NULL, *t = NULL;
 448         int r;
 449
 450         if (!seat)
 451                 return -EINVAL;
 452         if (!session && !uid)
 453                 return -EINVAL;
 454
 455         p = strappend("/run/systemd/seats/", seat);
 456         if (!p)
 457                 return -ENOMEM;
 458
 459         r = parse_env_file(p, NEWLINE,
 460                            "ACTIVE", &s,
 461                            "ACTIVE_UID", &t,
 462                            NULL);
 463         free(p);
 464
 465         if (r < 0) {
 466                 free(s);
 467                 free(t);
 468                 return r;
 469         }
 470
 471         if (session && !s)  {
 472                 free(t);
 473                 return -ENOENT;
 474         }
 475
 476         if (uid && !t) {
 477                 free(s);
 478                 return -ENOENT;
 479         }
 480
 481         if (uid && t) {
 482                 r = parse_uid(t, uid);
 483                 if (r < 0) {
 484                         free(t);
 485                         free(s);
 486                         return r;
 487                 }
 488         }
 489
 490         free(t);
 491
 492         if (session && s)
 493                 *session = s;
 494         else
 495                 free(s);
 496
 497         return 0;
 498 }
 499
 500 _public_ int sd_seat_get_sessions(const char *seat, char ***sessions, uid_t **uids, unsigned *n_uids) {
 501         char *p, *s = NULL, *t = NULL, **a = NULL;
 502         uid_t *b = NULL;
 503         unsigned n = 0;
 504         int r;
 505
 506         if (!seat)
 507                 return -EINVAL;
 508
 509         p = strappend("/run/systemd/seats/", seat);
 510         if (!p)
 511                 return -ENOMEM;
 512
 513         r = parse_env_file(p, NEWLINE,
 514                            "SESSIONS", &s,
 515                            "ACTIVE_SESSIONS", &t,
 516                            NULL);
 517         free(p);
 518
 519         if (r < 0) {
 520                 free(s);
 521                 free(t);
 522                 return r;
 523         }
 524
 525         if (s) {
 526                 a = strv_split(s, " ");
 527                 if (!a) {
 528                         free(s);
 529                         free(t);
 530                         return -ENOMEM;
 531                 }
 532         }
 533
 534         free(s);
 535
 536         if (uids && t) {
 537                 char *w, *state;
 538                 size_t l;
 539
 540                 FOREACH_WORD(w, l, t, state)
 541                         n++;
 542
 543                 if (n == 0)
 544                         b = NULL;
 545                 else {
 546                         unsigned i = 0;
 547
 548                         b = new(uid_t, n);
 549                         if (!b) {
 550                                 strv_free(a);
 551                                 return -ENOMEM;
 552                         }
 553
 554                         FOREACH_WORD(w, l, t, state) {
 555                                 char *k;
 556
 557                                 k = strndup(w, l);
 558                                 if (!k) {
 559                                         free(t);
 560                                         free(b);
 561                                         strv_free(a);
 562                                         return -ENOMEM;
 563                                 }
 564
 565                                 r = parse_uid(k, b + i);
 566                                 free(k);
 567                                 if (r < 0)
 568                                         continue;
 569
 570                                 i++;
 571                         }
 572                 }
 573         }
 574
 575         free(t);
 576
 577         r = strv_length(a);
 578
 579         if (sessions)
 580                 *sessions = a;
 581         else
 582                 strv_free(a);
 583
 584         if (uids)
 585                 *uids = b;
 586
 587         if (n_uids)
 588                 *n_uids = n;
 589
 590         return r;
 591 }
 592
 593 _public_ int sd_seat_can_multi_session(const char *seat) {
 594         char *p, *s = NULL;
 595         int r;
 596
 597         if (!seat)
 598                 return -EINVAL;
 599
 600         p = strappend("/run/systemd/seats/", seat);
 601         if (!p)
 602                 return -ENOMEM;
 603
 604         r = parse_env_file(p, NEWLINE,
 605                            "CAN_MULTI_SESSION", &s,
 606                            NULL);
 607         free(p);
 608
 609         if (r < 0) {
 610                 free(s);
 611                 return r;
 612         }
 613
 614         if (s) {
 615                 r = parse_boolean(s);
 616                 free(s);
 617         } else
 618                 r = 0;
 619
 620         return r;
 621 }
 622
 623 _public_ int sd_get_seats(char ***seats) {
 624         return get_files_in_directory("/run/systemd/seats/", seats);
 625 }
 626
 627 _public_ int sd_get_sessions(char ***sessions) {
 628         return get_files_in_directory("/run/systemd/sessions/", sessions);
 629 }
 630
 631 _public_ int sd_get_uids(uid_t **users) {
 632         DIR *d;
 633         int r = 0;
 634         unsigned n = 0;
 635         uid_t *l = NULL;
 636
 637         d = opendir("/run/systemd/users/");
 638         if (!d)
 639                 return -errno;
 640
 641         for (;;) {
 642                 struct dirent buffer, *de;
 643                 int k;
 644                 uid_t uid;
 645
 646                 k = readdir_r(d, &buffer, &de);
 647                 if (k != 0) {
 648                         r = -k;
 649                         goto finish;
 650                 }
 651
 652                 if (!de)
 653                         break;
 654
 655                 dirent_ensure_type(d, de);
 656
 657                 if (!dirent_is_file(de))
 658                         continue;
 659
 660                 k = parse_uid(de->d_name, &uid);
 661                 if (k < 0)
 662                         continue;
 663
 664                 if (users) {
 665                         if ((unsigned) r >= n) {
 666                                 uid_t *t;
 667
 668                                 n = MAX(16, 2*r);
 669                                 t = realloc(l, sizeof(uid_t) * n);
 670                                 if (!t) {
 671                                         r = -ENOMEM;
 672                                         goto finish;
 673                                 }
 674
 675                                 l = t;
 676                         }
 677
 678                         assert((unsigned) r < n);
 679                         l[r++] = uid;
 680                 } else
 681                         r++;
 682         }
 683
 684 finish:
 685         if (d)
 686                 closedir(d);
 687
 688         if (r >= 0) {
 689                 if (users)
 690                         *users = l;
 691         } else
 692                 free(l);
 693
 694         return r;
 695 }
 696
 697 static inline int MONITOR_TO_FD(sd_login_monitor *m) {
 698         return (int) (unsigned long) m - 1;
 699 }
 700
 701 static inline sd_login_monitor* FD_TO_MONITOR(int fd) {
 702         return (sd_login_monitor*) (unsigned long) (fd + 1);
 703 }
 704
 705 _public_ int sd_login_monitor_new(const char *category, sd_login_monitor **m) {
 706         int fd, k;
 707         bool good = false;
 708
 709         if (!m)
 710                 return -EINVAL;
 711
 712         fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
 713         if (fd < 0)
 714                 return errno;
 715
 716         if (!category || streq(category, "seat")) {
 717                 k = inotify_add_watch(fd, "/run/systemd/seats/", IN_MOVED_TO|IN_DELETE);
 718                 if (k < 0) {
 719                         close_nointr_nofail(fd);
 720                         return -errno;
 721                 }
 722
 723                 good = true;
 724         }
 725
 726         if (!category || streq(category, "session")) {
 727                 k = inotify_add_watch(fd, "/run/systemd/sessions/", IN_MOVED_TO|IN_DELETE);
 728                 if (k < 0) {
 729                         close_nointr_nofail(fd);
 730                         return -errno;
 731                 }
 732
 733                 good = true;
 734         }
 735
 736         if (!category || streq(category, "uid")) {
 737                 k = inotify_add_watch(fd, "/run/systemd/users/", IN_MOVED_TO|IN_DELETE);
 738                 if (k < 0) {
 739                         close_nointr_nofail(fd);
 740                         return -errno;
 741                 }
 742
 743                 good = true;
 744         }
 745
 746         if (!good) {
 747                 close_nointr(fd);
 748                 return -EINVAL;
 749         }
 750
 751         *m = FD_TO_MONITOR(fd);
 752         return 0;
 753 }
 754
 755 _public_ sd_login_monitor* sd_login_monitor_unref(sd_login_monitor *m) {
 756         int fd;
 757
 758         if (!m)
 759                 return NULL;
 760
 761         fd = MONITOR_TO_FD(m);
 762         close_nointr(fd);
 763
 764         return NULL;
 765 }
 766
 767 _public_ int sd_login_monitor_flush(sd_login_monitor *m) {
 768
 769         if (!m)
 770                 return -EINVAL;
 771
 772         return flush_fd(MONITOR_TO_FD(m));
 773 }
 774
 775 _public_ int sd_login_monitor_get_fd(sd_login_monitor *m) {
 776
 777         if (!m)
 778                 return -EINVAL;
 779
 780         return MONITOR_TO_FD(m);
 781 }