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, *at, *b;
 127         size_t k;
 128
 129         if (!unit)
 130                 return -EINVAL;
 131
 132         r = pid_get_cgroup(pid, NULL, &cgroup);
 133         if (r < 0)
 134                 return r;
 135
 136         if (!startswith(cgroup, "/system/")) {
 137                 free(cgroup);
 138                 return -ENOENT;
 139         }
 140
 141         p = cgroup + 8;
 142         k = strcspn(p, "/");
 143
 144         at = memchr(p, '@', k);
 145         if (at && at[1] == '.') {
 146                 size_t j;
 147
 148                 /* This is a templated service */
 149                 if (p[k] != '/') {
 150                         free(cgroup);
 151                         return -EIO;
 152                 }
 153
 154                 j = strcspn(p+k+1, "/");
 155
 156                 b = malloc(k + j + 1);
 157
 158                 if (b) {
 159                         memcpy(b, p, at - p + 1);
 160                         memcpy(b + (at - p) + 1, p + k + 1, j);
 161                         memcpy(b + (at - p) + 1 + j, at + 1, k - (at - p) - 1);
 162                         b[k+j] = 0;
 163                 }
 164         } else
 165                   b = strndup(p, k);
 166
 167         free(cgroup);
 168
 169         if (!b)
 170                 return -ENOMEM;
 171
 172         *unit = b;
 173         return 0;
 174 }
 175
 176 _public_ int sd_pid_get_owner_uid(pid_t pid, uid_t *uid) {
 177         int r;
 178         char *root, *cgroup, *p, *cc;
 179         struct stat st;
 180
 181         if (!uid)
 182                 return -EINVAL;
 183
 184         r = pid_get_cgroup(pid, &root, &cgroup);
 185         if (r < 0)
 186                 return r;
 187
 188         if (!startswith(cgroup, "/user/")) {
 189                 free(cgroup);
 190                 free(root);
 191                 return -ENOENT;
 192         }
 193
 194         p = strchr(cgroup + 6, '/');
 195         if (!p) {
 196                 free(cgroup);
 197                 return -ENOENT;
 198         }
 199
 200         p++;
 201         p += strcspn(p, "/");
 202         *p = 0;
 203
 204         r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, root, cgroup, &cc);
 205         free(root);
 206         free(cgroup);
 207
 208         if (r < 0)
 209                 return -ENOMEM;
 210
 211         r = lstat(cc, &st);
 212         free(cc);
 213
 214         if (r < 0)
 215                 return -errno;
 216
 217         if (!S_ISDIR(st.st_mode))
 218                 return -ENOTDIR;
 219
 220         *uid = st.st_uid;
 221         return 0;
 222 }
 223
 224 _public_ int sd_uid_get_state(uid_t uid, char**state) {
 225         char *p, *s = NULL;
 226         int r;
 227
 228         if (!state)
 229                 return -EINVAL;
 230
 231         if (asprintf(&p, "/run/systemd/users/%lu", (unsigned long) uid) < 0)
 232                 return -ENOMEM;
 233
 234         r = parse_env_file(p, NEWLINE, "STATE", &s, NULL);
 235         free(p);
 236
 237         if (r == -ENOENT) {
 238                 free(s);
 239                 s = strdup("offline");
 240                 if (!s)
 241                         return -ENOMEM;
 242
 243                 *state = s;
 244                 return 0;
 245         } else if (r < 0) {
 246                 free(s);
 247                 return r;
 248         } else if (!s)
 249                 return -EIO;
 250
 251         *state = s;
 252         return 0;
 253 }
 254
 255 _public_ int sd_uid_is_on_seat(uid_t uid, int require_active, const char *seat) {
 256         char *p, *w, *t, *state, *s = NULL;
 257         size_t l;
 258         int r;
 259         const char *variable;
 260
 261         if (!seat)
 262                 return -EINVAL;
 263
 264         variable = require_active ? "ACTIVE_UID" : "UIDS";
 265
 266         p = strappend("/run/systemd/seats/", seat);
 267         if (!p)
 268                 return -ENOMEM;
 269
 270         r = parse_env_file(p, NEWLINE, variable, &s, NULL);
 271         free(p);
 272
 273         if (r < 0) {
 274                 free(s);
 275                 return r;
 276         }
 277
 278         if (!s)
 279                 return -EIO;
 280
 281         if (asprintf(&t, "%lu", (unsigned long) uid) < 0) {
 282                 free(s);
 283                 return -ENOMEM;
 284         }
 285
 286         FOREACH_WORD(w, l, s, state) {
 287                 if (strncmp(t, w, l) == 0) {
 288                         free(s);
 289                         free(t);
 290
 291                         return 1;
 292                 }
 293         }
 294
 295         free(s);
 296         free(t);
 297
 298         return 0;
 299 }
 300
 301 static int uid_get_array(uid_t uid, const char *variable, char ***array) {
 302         char *p, *s = NULL;
 303         char **a;
 304         int r;
 305
 306         if (asprintf(&p, "/run/systemd/users/%lu", (unsigned long) uid) < 0)
 307                 return -ENOMEM;
 308
 309         r = parse_env_file(p, NEWLINE,
 310                            variable, &s,
 311                            NULL);
 312         free(p);
 313
 314         if (r < 0) {
 315                 free(s);
 316
 317                 if (r == -ENOENT) {
 318                         if (array)
 319                                 *array = NULL;
 320                         return 0;
 321                 }
 322
 323                 return r;
 324         }
 325
 326         if (!s) {
 327                 if (array)
 328                         *array = NULL;
 329                 return 0;
 330         }
 331
 332         a = strv_split(s, " ");
 333         free(s);
 334
 335         if (!a)
 336                 return -ENOMEM;
 337
 338         strv_uniq(a);
 339         r = strv_length(a);
 340
 341         if (array)
 342                 *array = a;
 343         else
 344                 strv_free(a);
 345
 346         return r;
 347 }
 348
 349 _public_ int sd_uid_get_sessions(uid_t uid, int require_active, char ***sessions) {
 350         return uid_get_array(uid, require_active ? "ACTIVE_SESSIONS" : "SESSIONS", sessions);
 351 }
 352
 353 _public_ int sd_uid_get_seats(uid_t uid, int require_active, char ***seats) {
 354         return uid_get_array(uid, require_active ? "ACTIVE_SEATS" : "SEATS", seats);
 355 }
 356
 357 _public_ int sd_session_is_active(const char *session) {
 358         int r;
 359         char *p, *s = NULL;
 360
 361         if (!session)
 362                 return -EINVAL;
 363
 364         p = strappend("/run/systemd/sessions/", session);
 365         if (!p)
 366                 return -ENOMEM;
 367
 368         r = parse_env_file(p, NEWLINE, "ACTIVE", &s, NULL);
 369         free(p);
 370
 371         if (r < 0) {
 372                 free(s);
 373                 return r;
 374         }
 375
 376         if (!s)
 377                 return -EIO;
 378
 379         r = parse_boolean(s);
 380         free(s);
 381
 382         return r;
 383 }
 384
 385 _public_ int sd_session_get_uid(const char *session, uid_t *uid) {
 386         int r;
 387         char *p, *s = NULL;
 388
 389         if (!session)
 390                 return -EINVAL;
 391         if (!uid)
 392                 return -EINVAL;
 393
 394         p = strappend("/run/systemd/sessions/", session);
 395         if (!p)
 396                 return -ENOMEM;
 397
 398         r = parse_env_file(p, NEWLINE, "UID", &s, NULL);
 399         free(p);
 400
 401         if (r < 0) {
 402                 free(s);
 403                 return r;
 404         }
 405
 406         if (!s)
 407                 return -EIO;
 408
 409         r = parse_uid(s, uid);
 410         free(s);
 411
 412         return r;
 413 }
 414
 415 _public_ int sd_session_get_seat(const char *session, char **seat) {
 416         char *p, *s = NULL;
 417         int r;
 418
 419         if (!session)
 420                 return -EINVAL;
 421         if (!seat)
 422                 return -EINVAL;
 423
 424         p = strappend("/run/systemd/sessions/", session);
 425         if (!p)
 426                 return -ENOMEM;
 427
 428         r = parse_env_file(p, NEWLINE, "SEAT", &s, NULL);
 429         free(p);
 430
 431         if (r < 0) {
 432                 free(s);
 433                 return r;
 434         }
 435
 436         if (isempty(s))
 437                 return -ENOENT;
 438
 439         *seat = s;
 440         return 0;
 441 }
 442
 443 _public_ int sd_session_get_service(const char *session, char **service) {
 444         char *p, *s = NULL;
 445         int r;
 446
 447         if (!session)
 448                 return -EINVAL;
 449         if (!service)
 450                 return -EINVAL;
 451
 452         p = strappend("/run/systemd/sessions/", session);
 453         if (!p)
 454                 return -ENOMEM;
 455
 456         r = parse_env_file(p, NEWLINE, "SERVICE", &s, NULL);
 457         free(p);
 458
 459         if (r < 0) {
 460                 free(s);
 461                 return r;
 462         }
 463
 464         if (isempty(s))
 465                 return -ENOENT;
 466
 467         *service = s;
 468         return 0;
 469 }
 470
 471 _public_ int sd_seat_get_active(const char *seat, char **session, uid_t *uid) {
 472         char *p, *s = NULL, *t = NULL;
 473         int r;
 474
 475         if (!seat)
 476                 return -EINVAL;
 477         if (!session && !uid)
 478                 return -EINVAL;
 479
 480         p = strappend("/run/systemd/seats/", seat);
 481         if (!p)
 482                 return -ENOMEM;
 483
 484         r = parse_env_file(p, NEWLINE,
 485                            "ACTIVE", &s,
 486                            "ACTIVE_UID", &t,
 487                            NULL);
 488         free(p);
 489
 490         if (r < 0) {
 491                 free(s);
 492                 free(t);
 493                 return r;
 494         }
 495
 496         if (session && !s)  {
 497                 free(t);
 498                 return -ENOENT;
 499         }
 500
 501         if (uid && !t) {
 502                 free(s);
 503                 return -ENOENT;
 504         }
 505
 506         if (uid && t) {
 507                 r = parse_uid(t, uid);
 508                 if (r < 0) {
 509                         free(t);
 510                         free(s);
 511                         return r;
 512                 }
 513         }
 514
 515         free(t);
 516
 517         if (session && s)
 518                 *session = s;
 519         else
 520                 free(s);
 521
 522         return 0;
 523 }
 524
 525 _public_ int sd_seat_get_sessions(const char *seat, char ***sessions, uid_t **uids, unsigned *n_uids) {
 526         char *p, *s = NULL, *t = NULL, **a = NULL;
 527         uid_t *b = NULL;
 528         unsigned n = 0;
 529         int r;
 530
 531         if (!seat)
 532                 return -EINVAL;
 533
 534         p = strappend("/run/systemd/seats/", seat);
 535         if (!p)
 536                 return -ENOMEM;
 537
 538         r = parse_env_file(p, NEWLINE,
 539                            "SESSIONS", &s,
 540                            "ACTIVE_SESSIONS", &t,
 541                            NULL);
 542         free(p);
 543
 544         if (r < 0) {
 545                 free(s);
 546                 free(t);
 547                 return r;
 548         }
 549
 550         if (s) {
 551                 a = strv_split(s, " ");
 552                 if (!a) {
 553                         free(s);
 554                         free(t);
 555                         return -ENOMEM;
 556                 }
 557         }
 558
 559         free(s);
 560
 561         if (uids && t) {
 562                 char *w, *state;
 563                 size_t l;
 564
 565                 FOREACH_WORD(w, l, t, state)
 566                         n++;
 567
 568                 if (n == 0)
 569                         b = NULL;
 570                 else {
 571                         unsigned i = 0;
 572
 573                         b = new(uid_t, n);
 574                         if (!b) {
 575                                 strv_free(a);
 576                                 return -ENOMEM;
 577                         }
 578
 579                         FOREACH_WORD(w, l, t, state) {
 580                                 char *k;
 581
 582                                 k = strndup(w, l);
 583                                 if (!k) {
 584                                         free(t);
 585                                         free(b);
 586                                         strv_free(a);
 587                                         return -ENOMEM;
 588                                 }
 589
 590                                 r = parse_uid(k, b + i);
 591                                 free(k);
 592                                 if (r < 0)
 593                                         continue;
 594
 595                                 i++;
 596                         }
 597                 }
 598         }
 599
 600         free(t);
 601
 602         r = strv_length(a);
 603
 604         if (sessions)
 605                 *sessions = a;
 606         else
 607                 strv_free(a);
 608
 609         if (uids)
 610                 *uids = b;
 611
 612         if (n_uids)
 613                 *n_uids = n;
 614
 615         return r;
 616 }
 617
 618 _public_ int sd_seat_can_multi_session(const char *seat) {
 619         char *p, *s = NULL;
 620         int r;
 621
 622         if (!seat)
 623                 return -EINVAL;
 624
 625         p = strappend("/run/systemd/seats/", seat);
 626         if (!p)
 627                 return -ENOMEM;
 628
 629         r = parse_env_file(p, NEWLINE,
 630                            "CAN_MULTI_SESSION", &s,
 631                            NULL);
 632         free(p);
 633
 634         if (r < 0) {
 635                 free(s);
 636                 return r;
 637         }
 638
 639         if (s) {
 640                 r = parse_boolean(s);
 641                 free(s);
 642         } else
 643                 r = 0;
 644
 645         return r;
 646 }
 647
 648 _public_ int sd_get_seats(char ***seats) {
 649         return get_files_in_directory("/run/systemd/seats/", seats);
 650 }
 651
 652 _public_ int sd_get_sessions(char ***sessions) {
 653         return get_files_in_directory("/run/systemd/sessions/", sessions);
 654 }
 655
 656 _public_ int sd_get_uids(uid_t **users) {
 657         DIR *d;
 658         int r = 0;
 659         unsigned n = 0;
 660         uid_t *l = NULL;
 661
 662         d = opendir("/run/systemd/users/");
 663         if (!d)
 664                 return -errno;
 665
 666         for (;;) {
 667                 struct dirent buffer, *de;
 668                 int k;
 669                 uid_t uid;
 670
 671                 k = readdir_r(d, &buffer, &de);
 672                 if (k != 0) {
 673                         r = -k;
 674                         goto finish;
 675                 }
 676
 677                 if (!de)
 678                         break;
 679
 680                 dirent_ensure_type(d, de);
 681
 682                 if (!dirent_is_file(de))
 683                         continue;
 684
 685                 k = parse_uid(de->d_name, &uid);
 686                 if (k < 0)
 687                         continue;
 688
 689                 if (users) {
 690                         if ((unsigned) r >= n) {
 691                                 uid_t *t;
 692
 693                                 n = MAX(16, 2*r);
 694                                 t = realloc(l, sizeof(uid_t) * n);
 695                                 if (!t) {
 696                                         r = -ENOMEM;
 697                                         goto finish;
 698                                 }
 699
 700                                 l = t;
 701                         }
 702
 703                         assert((unsigned) r < n);
 704                         l[r++] = uid;
 705                 } else
 706                         r++;
 707         }
 708
 709 finish:
 710         if (d)
 711                 closedir(d);
 712
 713         if (r >= 0) {
 714                 if (users)
 715                         *users = l;
 716         } else
 717                 free(l);
 718
 719         return r;
 720 }
 721
 722 static inline int MONITOR_TO_FD(sd_login_monitor *m) {
 723         return (int) (unsigned long) m - 1;
 724 }
 725
 726 static inline sd_login_monitor* FD_TO_MONITOR(int fd) {
 727         return (sd_login_monitor*) (unsigned long) (fd + 1);
 728 }
 729
 730 _public_ int sd_login_monitor_new(const char *category, sd_login_monitor **m) {
 731         int fd, k;
 732         bool good = false;
 733
 734         if (!m)
 735                 return -EINVAL;
 736
 737         fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
 738         if (fd < 0)
 739                 return errno;
 740
 741         if (!category || streq(category, "seat")) {
 742                 k = inotify_add_watch(fd, "/run/systemd/seats/", IN_MOVED_TO|IN_DELETE);
 743                 if (k < 0) {
 744                         close_nointr_nofail(fd);
 745                         return -errno;
 746                 }
 747
 748                 good = true;
 749         }
 750
 751         if (!category || streq(category, "session")) {
 752                 k = inotify_add_watch(fd, "/run/systemd/sessions/", IN_MOVED_TO|IN_DELETE);
 753                 if (k < 0) {
 754                         close_nointr_nofail(fd);
 755                         return -errno;
 756                 }
 757
 758                 good = true;
 759         }
 760
 761         if (!category || streq(category, "uid")) {
 762                 k = inotify_add_watch(fd, "/run/systemd/users/", IN_MOVED_TO|IN_DELETE);
 763                 if (k < 0) {
 764                         close_nointr_nofail(fd);
 765                         return -errno;
 766                 }
 767
 768                 good = true;
 769         }
 770
 771         if (!good) {
 772                 close_nointr(fd);
 773                 return -EINVAL;
 774         }
 775
 776         *m = FD_TO_MONITOR(fd);
 777         return 0;
 778 }
 779
 780 _public_ sd_login_monitor* sd_login_monitor_unref(sd_login_monitor *m) {
 781         int fd;
 782
 783         if (!m)
 784                 return NULL;
 785
 786         fd = MONITOR_TO_FD(m);
 787         close_nointr(fd);
 788
 789         return NULL;
 790 }
 791
 792 _public_ int sd_login_monitor_flush(sd_login_monitor *m) {
 793
 794         if (!m)
 795                 return -EINVAL;
 796
 797         return flush_fd(MONITOR_TO_FD(m));
 798 }
 799
 800 _public_ int sd_login_monitor_get_fd(sd_login_monitor *m) {
 801
 802         if (!m)
 803                 return -EINVAL;
 804
 805         return MONITOR_TO_FD(m);
 806 }