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 static int file_of_session(const char *session, char **_p) {
 358         char *p;
 359         int r;
 360
 361         assert(_p);
 362
 363         if (session)
 364                 p = strappend("/run/systemd/sessions/", session);
 365         else {
 366                 char *buf;
 367
 368                 r = sd_pid_get_session(0, &buf);
 369                 if (r < 0)
 370                         return r;
 371
 372                 p = strappend("/run/systemd/sessions/", buf);
 373                 free(buf);
 374         }
 375
 376         if (!p)
 377                 return -ENOMEM;
 378
 379         *_p = p;
 380         return 0;
 381 }
 382
 383 _public_ int sd_session_is_active(const char *session) {
 384         int r;
 385         char *p, *s = NULL;
 386
 387         r = file_of_session(session, &p);
 388         if (r < 0)
 389                 return r;
 390
 391         r = parse_env_file(p, NEWLINE, "ACTIVE", &s, NULL);
 392         free(p);
 393
 394         if (r < 0) {
 395                 free(s);
 396                 return r;
 397         }
 398
 399         if (!s)
 400                 return -EIO;
 401
 402         r = parse_boolean(s);
 403         free(s);
 404
 405         return r;
 406 }
 407
 408 _public_ int sd_session_get_uid(const char *session, uid_t *uid) {
 409         int r;
 410         char *p, *s = NULL;
 411
 412         if (!uid)
 413                 return -EINVAL;
 414
 415         r = file_of_session(session, &p);
 416         if (r < 0)
 417                 return r;
 418
 419         r = parse_env_file(p, NEWLINE, "UID", &s, NULL);
 420         free(p);
 421
 422         if (r < 0) {
 423                 free(s);
 424                 return r;
 425         }
 426
 427         if (!s)
 428                 return -EIO;
 429
 430         r = parse_uid(s, uid);
 431         free(s);
 432
 433         return r;
 434 }
 435
 436 static int session_get_string(const char *session, const char *field, char **value) {
 437         char *p, *s = NULL;
 438         int r;
 439
 440         if (!value)
 441                 return -EINVAL;
 442
 443         r = file_of_session(session, &p);
 444         if (r < 0)
 445                 return r;
 446
 447         r = parse_env_file(p, NEWLINE, field, &s, NULL);
 448         free(p);
 449
 450         if (r < 0) {
 451                 free(s);
 452                 return r;
 453         }
 454
 455         if (isempty(s))
 456                 return -ENOENT;
 457
 458         *value = s;
 459         return 0;
 460 }
 461
 462 _public_ int sd_session_get_seat(const char *session, char **seat) {
 463         return session_get_string(session, "SEAT", seat);
 464 }
 465
 466 _public_ int sd_session_get_service(const char *session, char **service) {
 467         return session_get_string(session, "SERVICE", service);
 468 }
 469
 470 _public_ int sd_session_get_type(const char *session, char **type) {
 471         return session_get_string(session, "TYPE", type);
 472 }
 473
 474 _public_ int sd_session_get_class(const char *session, char **class) {
 475         return session_get_string(session, "CLASS", class);
 476 }
 477
 478 static int file_of_seat(const char *seat, char **_p) {
 479         char *p;
 480         int r;
 481
 482         assert(_p);
 483
 484         if (seat)
 485                 p = strappend("/run/systemd/seats/", seat);
 486         else {
 487                 char *buf;
 488
 489                 r = sd_session_get_seat(NULL, &buf);
 490                 if (r < 0)
 491                         return r;
 492
 493                 p = strappend("/run/systemd/seats/", buf);
 494                 free(buf);
 495         }
 496
 497         if (!p)
 498                 return -ENOMEM;
 499
 500         *_p = p;
 501         return 0;
 502 }
 503
 504 _public_ int sd_seat_get_active(const char *seat, char **session, uid_t *uid) {
 505         char *p, *s = NULL, *t = NULL;
 506         int r;
 507
 508         if (!session && !uid)
 509                 return -EINVAL;
 510
 511         r = file_of_seat(seat, &p);
 512         if (r < 0)
 513                 return r;
 514
 515         r = parse_env_file(p, NEWLINE,
 516                            "ACTIVE", &s,
 517                            "ACTIVE_UID", &t,
 518                            NULL);
 519         free(p);
 520
 521         if (r < 0) {
 522                 free(s);
 523                 free(t);
 524                 return r;
 525         }
 526
 527         if (session && !s)  {
 528                 free(t);
 529                 return -ENOENT;
 530         }
 531
 532         if (uid && !t) {
 533                 free(s);
 534                 return -ENOENT;
 535         }
 536
 537         if (uid && t) {
 538                 r = parse_uid(t, uid);
 539                 if (r < 0) {
 540                         free(t);
 541                         free(s);
 542                         return r;
 543                 }
 544         }
 545
 546         free(t);
 547
 548         if (session && s)
 549                 *session = s;
 550         else
 551                 free(s);
 552
 553         return 0;
 554 }
 555
 556 _public_ int sd_seat_get_sessions(const char *seat, char ***sessions, uid_t **uids, unsigned *n_uids) {
 557         char *p, *s = NULL, *t = NULL, **a = NULL;
 558         uid_t *b = NULL;
 559         unsigned n = 0;
 560         int r;
 561
 562         r = file_of_seat(seat, &p);
 563         if (r < 0)
 564                 return r;
 565
 566         r = parse_env_file(p, NEWLINE,
 567                            "SESSIONS", &s,
 568                            "ACTIVE_SESSIONS", &t,
 569                            NULL);
 570         free(p);
 571
 572         if (r < 0) {
 573                 free(s);
 574                 free(t);
 575                 return r;
 576         }
 577
 578         if (s) {
 579                 a = strv_split(s, " ");
 580                 if (!a) {
 581                         free(s);
 582                         free(t);
 583                         return -ENOMEM;
 584                 }
 585         }
 586
 587         free(s);
 588
 589         if (uids && t) {
 590                 char *w, *state;
 591                 size_t l;
 592
 593                 FOREACH_WORD(w, l, t, state)
 594                         n++;
 595
 596                 if (n == 0)
 597                         b = NULL;
 598                 else {
 599                         unsigned i = 0;
 600
 601                         b = new(uid_t, n);
 602                         if (!b) {
 603                                 strv_free(a);
 604                                 return -ENOMEM;
 605                         }
 606
 607                         FOREACH_WORD(w, l, t, state) {
 608                                 char *k;
 609
 610                                 k = strndup(w, l);
 611                                 if (!k) {
 612                                         free(t);
 613                                         free(b);
 614                                         strv_free(a);
 615                                         return -ENOMEM;
 616                                 }
 617
 618                                 r = parse_uid(k, b + i);
 619                                 free(k);
 620                                 if (r < 0)
 621                                         continue;
 622
 623                                 i++;
 624                         }
 625                 }
 626         }
 627
 628         free(t);
 629
 630         r = strv_length(a);
 631
 632         if (sessions)
 633                 *sessions = a;
 634         else
 635                 strv_free(a);
 636
 637         if (uids)
 638                 *uids = b;
 639
 640         if (n_uids)
 641                 *n_uids = n;
 642
 643         return r;
 644 }
 645
 646 _public_ int sd_seat_can_multi_session(const char *seat) {
 647         char *p, *s = NULL;
 648         int r;
 649
 650         r = file_of_seat(seat, &p);
 651         if (r < 0)
 652                 return r;
 653
 654         r = parse_env_file(p, NEWLINE,
 655                            "CAN_MULTI_SESSION", &s,
 656                            NULL);
 657         free(p);
 658
 659         if (r < 0) {
 660                 free(s);
 661                 return r;
 662         }
 663
 664         if (s) {
 665                 r = parse_boolean(s);
 666                 free(s);
 667         } else
 668                 r = 0;
 669
 670         return r;
 671 }
 672
 673 _public_ int sd_get_seats(char ***seats) {
 674         return get_files_in_directory("/run/systemd/seats/", seats);
 675 }
 676
 677 _public_ int sd_get_sessions(char ***sessions) {
 678         return get_files_in_directory("/run/systemd/sessions/", sessions);
 679 }
 680
 681 _public_ int sd_get_uids(uid_t **users) {
 682         DIR *d;
 683         int r = 0;
 684         unsigned n = 0;
 685         uid_t *l = NULL;
 686
 687         d = opendir("/run/systemd/users/");
 688         if (!d)
 689                 return -errno;
 690
 691         for (;;) {
 692                 struct dirent buffer, *de;
 693                 int k;
 694                 uid_t uid;
 695
 696                 k = readdir_r(d, &buffer, &de);
 697                 if (k != 0) {
 698                         r = -k;
 699                         goto finish;
 700                 }
 701
 702                 if (!de)
 703                         break;
 704
 705                 dirent_ensure_type(d, de);
 706
 707                 if (!dirent_is_file(de))
 708                         continue;
 709
 710                 k = parse_uid(de->d_name, &uid);
 711                 if (k < 0)
 712                         continue;
 713
 714                 if (users) {
 715                         if ((unsigned) r >= n) {
 716                                 uid_t *t;
 717
 718                                 n = MAX(16, 2*r);
 719                                 t = realloc(l, sizeof(uid_t) * n);
 720                                 if (!t) {
 721                                         r = -ENOMEM;
 722                                         goto finish;
 723                                 }
 724
 725                                 l = t;
 726                         }
 727
 728                         assert((unsigned) r < n);
 729                         l[r++] = uid;
 730                 } else
 731                         r++;
 732         }
 733
 734 finish:
 735         if (d)
 736                 closedir(d);
 737
 738         if (r >= 0) {
 739                 if (users)
 740                         *users = l;
 741         } else
 742                 free(l);
 743
 744         return r;
 745 }
 746
 747 static inline int MONITOR_TO_FD(sd_login_monitor *m) {
 748         return (int) (unsigned long) m - 1;
 749 }
 750
 751 static inline sd_login_monitor* FD_TO_MONITOR(int fd) {
 752         return (sd_login_monitor*) (unsigned long) (fd + 1);
 753 }
 754
 755 _public_ int sd_login_monitor_new(const char *category, sd_login_monitor **m) {
 756         int fd, k;
 757         bool good = false;
 758
 759         if (!m)
 760                 return -EINVAL;
 761
 762         fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
 763         if (fd < 0)
 764                 return errno;
 765
 766         if (!category || streq(category, "seat")) {
 767                 k = inotify_add_watch(fd, "/run/systemd/seats/", IN_MOVED_TO|IN_DELETE);
 768                 if (k < 0) {
 769                         close_nointr_nofail(fd);
 770                         return -errno;
 771                 }
 772
 773                 good = true;
 774         }
 775
 776         if (!category || streq(category, "session")) {
 777                 k = inotify_add_watch(fd, "/run/systemd/sessions/", IN_MOVED_TO|IN_DELETE);
 778                 if (k < 0) {
 779                         close_nointr_nofail(fd);
 780                         return -errno;
 781                 }
 782
 783                 good = true;
 784         }
 785
 786         if (!category || streq(category, "uid")) {
 787                 k = inotify_add_watch(fd, "/run/systemd/users/", IN_MOVED_TO|IN_DELETE);
 788                 if (k < 0) {
 789                         close_nointr_nofail(fd);
 790                         return -errno;
 791                 }
 792
 793                 good = true;
 794         }
 795
 796         if (!good) {
 797                 close_nointr(fd);
 798                 return -EINVAL;
 799         }
 800
 801         *m = FD_TO_MONITOR(fd);
 802         return 0;
 803 }
 804
 805 _public_ sd_login_monitor* sd_login_monitor_unref(sd_login_monitor *m) {
 806         int fd;
 807
 808         if (!m)
 809                 return NULL;
 810
 811         fd = MONITOR_TO_FD(m);
 812         close_nointr(fd);
 813
 814         return NULL;
 815 }
 816
 817 _public_ int sd_login_monitor_flush(sd_login_monitor *m) {
 818
 819         if (!m)
 820                 return -EINVAL;
 821
 822         return flush_fd(MONITOR_TO_FD(m));
 823 }
 824
 825 _public_ int sd_login_monitor_get_fd(sd_login_monitor *m) {
 826
 827         if (!m)
 828                 return -EINVAL;
 829
 830         return MONITOR_TO_FD(m);
 831 }