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 (!array)
 255                 return -EINVAL;
 256
 257         if (asprintf(&p, "/run/systemd/users/%lu", (unsigned long) uid) < 0)
 258                 return -ENOMEM;
 259
 260         r = parse_env_file(p, NEWLINE,
 261                            variable, &s,
 262                            NULL);
 263         free(p);
 264
 265         if (r < 0) {
 266                 free(s);
 267
 268                 if (r == -ENOENT) {
 269                         *array = NULL;
 270                         return 0;
 271                 }
 272
 273                 return r;
 274         }
 275
 276         if (!s) {
 277                 *array = NULL;
 278                 return 0;
 279         }
 280
 281         a = strv_split(s, " ");
 282         free(s);
 283
 284         if (!a)
 285                 return -ENOMEM;
 286
 287         *array = a;
 288         return 0;
 289 }
 290
 291 _public_ int sd_uid_get_sessions(uid_t uid, int require_active, char ***sessions) {
 292         return uid_get_array(uid, require_active ? "ACTIVE_SESSIONS" : "SESSIONS", sessions);
 293 }
 294
 295 _public_ int sd_uid_get_seats(uid_t uid, int require_active, char ***seats) {
 296         return uid_get_array(uid, require_active ? "ACTIVE_SEATS" : "SEATS", seats);
 297 }
 298
 299 _public_ int sd_session_is_active(const char *session) {
 300         int r;
 301         char *p, *s = NULL;
 302
 303         if (!session)
 304                 return -EINVAL;
 305
 306         p = strappend("/run/systemd/sessions/", session);
 307         if (!p)
 308                 return -ENOMEM;
 309
 310         r = parse_env_file(p, NEWLINE, "ACTIVE", &s, NULL);
 311         free(p);
 312
 313         if (r < 0) {
 314                 free(s);
 315                 return r;
 316         }
 317
 318         if (!s)
 319                 return -EIO;
 320
 321         r = parse_boolean(s);
 322         free(s);
 323
 324         return r;
 325 }
 326
 327 _public_ int sd_session_get_uid(const char *session, uid_t *uid) {
 328         int r;
 329         char *p, *s = NULL;
 330
 331         if (!session)
 332                 return -EINVAL;
 333         if (!uid)
 334                 return -EINVAL;
 335
 336         p = strappend("/run/systemd/sessions/", session);
 337         if (!p)
 338                 return -ENOMEM;
 339
 340         r = parse_env_file(p, NEWLINE, "UID", &s, NULL);
 341         free(p);
 342
 343         if (r < 0) {
 344                 free(s);
 345                 return r;
 346         }
 347
 348         if (!s)
 349                 return -EIO;
 350
 351         r = parse_uid(s, uid);
 352         free(s);
 353
 354         return r;
 355 }
 356
 357 _public_ int sd_session_get_seat(const char *session, char **seat) {
 358         char *p, *s = NULL;
 359         int r;
 360
 361         if (!session)
 362                 return -EINVAL;
 363         if (!seat)
 364                 return -EINVAL;
 365
 366         p = strappend("/run/systemd/sessions/", session);
 367         if (!p)
 368                 return -ENOMEM;
 369
 370         r = parse_env_file(p, NEWLINE, "SEAT", &s, NULL);
 371         free(p);
 372
 373         if (r < 0) {
 374                 free(s);
 375                 return r;
 376         }
 377
 378         if (isempty(s))
 379                 return -ENOENT;
 380
 381         *seat = s;
 382         return 0;
 383 }
 384
 385 _public_ int sd_seat_get_active(const char *seat, char **session, uid_t *uid) {
 386         char *p, *s = NULL, *t = NULL;
 387         int r;
 388
 389         if (!seat)
 390                 return -EINVAL;
 391         if (!session && !uid)
 392                 return -EINVAL;
 393
 394         p = strappend("/run/systemd/seats/", seat);
 395         if (!p)
 396                 return -ENOMEM;
 397
 398         r = parse_env_file(p, NEWLINE,
 399                            "ACTIVE", &s,
 400                            "ACTIVE_UID", &t,
 401                            NULL);
 402         free(p);
 403
 404         if (r < 0) {
 405                 free(s);
 406                 free(t);
 407                 return r;
 408         }
 409
 410         if (session && !s)  {
 411                 free(t);
 412                 return -ENOENT;
 413         }
 414
 415         if (uid && !t) {
 416                 free(s);
 417                 return -ENOENT;
 418         }
 419
 420         if (uid && t) {
 421                 r = parse_uid(t, uid);
 422                 if (r < 0) {
 423                         free(t);
 424                         free(s);
 425                         return r;
 426                 }
 427         }
 428
 429         free(t);
 430
 431         if (session && s)
 432                 *session = s;
 433         else
 434                 free(s);
 435
 436         return 0;
 437 }
 438
 439 _public_ int sd_seat_get_sessions(const char *seat, char ***sessions, uid_t **uids, unsigned *n_uids) {
 440         char *p, *s = NULL, *t = NULL, **a = NULL;
 441         uid_t *b = NULL;
 442         unsigned n = 0;
 443         int r;
 444
 445         if (!seat)
 446                 return -EINVAL;
 447
 448         if (!sessions && !uids)
 449                 return -EINVAL;
 450
 451         p = strappend("/run/systemd/seats/", seat);
 452         if (!p)
 453                 return -ENOMEM;
 454
 455         r = parse_env_file(p, NEWLINE,
 456                            "SESSIONS", &s,
 457                            "ACTIVE_SESSIONS", &t,
 458                            NULL);
 459         free(p);
 460
 461         if (r < 0) {
 462                 free(s);
 463                 free(t);
 464                 return r;
 465         }
 466
 467         if (sessions && s) {
 468                 a = strv_split(s, " ");
 469                 if (!a) {
 470                         free(s);
 471                         free(t);
 472                         return -ENOMEM;
 473                 }
 474         }
 475
 476         free(s);
 477
 478         if (uids && t) {
 479                 char *w, *state;
 480                 size_t l;
 481                 unsigned i = 0;
 482
 483                 FOREACH_WORD(w, l, t, state)
 484                         n++;
 485
 486                 b = new(uid_t, n);
 487                 if (!b) {
 488                         strv_free(a);
 489                         return -ENOMEM;
 490                 }
 491
 492                 FOREACH_WORD(w, l, t, state) {
 493                         char *k;
 494
 495                         k = strndup(w, l);
 496                         if (!k) {
 497                                 free(t);
 498                                 free(b);
 499                                 return -ENOMEM;
 500                         }
 501
 502                         r = parse_uid(k, b + i);
 503                         free(k);
 504                         if (r < 0)
 505                                 continue;
 506
 507                         i++;
 508                 }
 509         }
 510
 511         free(t);
 512
 513         if (sessions)
 514                 *sessions = a;
 515
 516         if (uids)
 517                 *uids = b;
 518
 519         if (n_uids)
 520                 *n_uids = n;
 521
 522         return 0;
 523 }
 524
 525 _public_ int sd_seat_can_multi_session(const char *seat) {
 526         char *p, *s = NULL;
 527         int r;
 528
 529         if (!seat)
 530                 return -EINVAL;
 531
 532         p = strappend("/run/systemd/seats/", seat);
 533         if (!p)
 534                 return -ENOMEM;
 535
 536         r = parse_env_file(p, NEWLINE,
 537                            "IS_VTCONSOLE", &s,
 538                            NULL);
 539         free(p);
 540
 541         if (r < 0) {
 542                 free(s);
 543                 return r;
 544         }
 545
 546         if (s) {
 547                 r = parse_boolean(s);
 548                 free(s);
 549         } else
 550                 r = 0;
 551
 552         return r;
 553 }
 554
 555 _public_ int sd_get_seats(char ***seats) {
 556
 557         if (!seats)
 558                 return -EINVAL;
 559
 560         return get_files_in_directory("/run/systemd/seats/", seats);
 561 }
 562
 563 _public_ int sd_get_sessions(char ***sessions) {
 564
 565         if (!sessions)
 566                 return -EINVAL;
 567
 568         return get_files_in_directory("/run/systemd/sessions/", sessions);
 569 }
 570
 571 _public_ int sd_get_uids(uid_t **users) {
 572         DIR *d;
 573         int r = 0;
 574         unsigned n = 0;
 575         uid_t *l = NULL;
 576
 577         if (!users)
 578                 return -EINVAL;
 579
 580         d = opendir("/run/systemd/users/");
 581         for (;;) {
 582                 struct dirent buffer, *de;
 583                 int k;
 584                 uid_t uid;
 585
 586                 k = readdir_r(d, &buffer, &de);
 587                 if (k != 0) {
 588                         r = -k;
 589                         goto finish;
 590                 }
 591
 592                 if (!de)
 593                         break;
 594
 595                 dirent_ensure_type(d, de);
 596
 597                 if (!dirent_is_file(de))
 598                         continue;
 599
 600                 k = parse_uid(de->d_name, &uid);
 601                 if (k < 0)
 602                         continue;
 603
 604                 if ((unsigned) r >= n) {
 605                         uid_t *t;
 606
 607                         n = MAX(16, 2*r);
 608                         t = realloc(l, sizeof(uid_t) * n);
 609                         if (!t) {
 610                                 r = -ENOMEM;
 611                                 goto finish;
 612                         }
 613
 614                         l = t;
 615                 }
 616
 617                 assert((unsigned) r < n);
 618                 l[r++] = uid;
 619         }
 620
 621 finish:
 622         if (d)
 623                 closedir(d);
 624
 625         if (r >= 0)
 626                 *users = l;
 627         else
 628                 free(l);
 629
 630         return r;
 631 }
 632
 633 static inline int MONITOR_TO_FD(sd_login_monitor *m) {
 634         return (int) (unsigned long) m - 1;
 635 }
 636
 637 static inline sd_login_monitor* FD_TO_MONITOR(int fd) {
 638         return (sd_login_monitor*) (unsigned long) (fd + 1);
 639 }
 640
 641 _public_ int sd_login_monitor_new(const char *category, sd_login_monitor **m) {
 642         int fd, k;
 643         bool good = false;
 644
 645         if (!m)
 646                 return -EINVAL;
 647
 648         fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
 649         if (fd < 0)
 650                 return errno;
 651
 652         if (!category || streq(category, "seat")) {
 653                 k = inotify_add_watch(fd, "/run/systemd/seats/", IN_MOVED_TO|IN_DELETE);
 654                 if (k < 0) {
 655                         close_nointr_nofail(fd);
 656                         return -errno;
 657                 }
 658
 659                 good = true;
 660         }
 661
 662         if (!category || streq(category, "session")) {
 663                 k = inotify_add_watch(fd, "/run/systemd/sessions/", IN_MOVED_TO|IN_DELETE);
 664                 if (k < 0) {
 665                         close_nointr_nofail(fd);
 666                         return -errno;
 667                 }
 668
 669                 good = true;
 670         }
 671
 672         if (!category || streq(category, "uid")) {
 673                 k = inotify_add_watch(fd, "/run/systemd/users/", IN_MOVED_TO|IN_DELETE);
 674                 if (k < 0) {
 675                         close_nointr_nofail(fd);
 676                         return -errno;
 677                 }
 678
 679                 good = true;
 680         }
 681
 682         if (!good) {
 683                 close_nointr(fd);
 684                 return -EINVAL;
 685         }
 686
 687         *m = FD_TO_MONITOR(fd);
 688         return 0;
 689 }
 690
 691 _public_ sd_login_monitor* sd_login_monitor_unref(sd_login_monitor *m) {
 692         int fd;
 693
 694         if (!m)
 695                 return NULL;
 696
 697         fd = MONITOR_TO_FD(m);
 698         close_nointr(fd);
 699
 700         return NULL;
 701 }
 702
 703 _public_ int sd_login_monitor_flush(sd_login_monitor *m) {
 704
 705         if (!m)
 706                 return -EINVAL;
 707
 708         return flush_fd(MONITOR_TO_FD(m));
 709 }
 710
 711 _public_ int sd_login_monitor_get_fd(sd_login_monitor *m) {
 712
 713         if (!m)
 714                 return -EINVAL;
 715
 716         return MONITOR_TO_FD(m);
 717 }