src/tmpfiles.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering, Kay Sievers
   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 <fcntl.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <sys/stat.h>
  27 #include <limits.h>
  28 #include <dirent.h>
  29 #include <grp.h>
  30 #include <pwd.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <stddef.h>
  34 #include <getopt.h>
  35 #include <stdbool.h>
  36 #include <time.h>
  37 #include <sys/types.h>
  38 #include <sys/param.h>
  39
  40 #include "log.h"
  41 #include "util.h"
  42 #include "strv.h"
  43 #include "label.h"
  44 #include "set.h"
  45
  46 /* This reads all files listed in /etc/tmpfiles.d/?*.conf and creates
  47  * them in the file system. This is intended to be used to create
  48  * properly owned directories beneath /tmp, /var/tmp, /var/run and
  49  * /var/lock which are volatile and hence need to be recreated on
  50  * bootup. */
  51
  52 enum {
  53         CREATE_FILE = 'f',
  54         TRUNCATE_FILE = 'F',
  55         CREATE_DIRECTORY = 'd',
  56         TRUNCATE_DIRECTORY = 'D',
  57         IGNORE_PATH = 'x',
  58         REMOVE_PATH = 'r',
  59         RECURSIVE_REMOVE_PATH = 'R'
  60 };
  61
  62 typedef struct Item {
  63         char type;
  64
  65         char *path;
  66         uid_t uid;
  67         gid_t gid;
  68         mode_t mode;
  69         usec_t age;
  70
  71         bool uid_set:1;
  72         bool gid_set:1;
  73         bool mode_set:1;
  74         bool age_set:1;
  75 } Item;
  76
  77 static Hashmap *items = NULL;
  78
  79 static bool arg_create = false;
  80 static bool arg_clean = false;
  81 static bool arg_remove = false;
  82
  83 #define MAX_DEPTH 256
  84
  85 static int dir_cleanup(
  86                 const char *p,
  87                 DIR *d,
  88                 const struct stat *ds,
  89                 usec_t cutoff,
  90                 dev_t rootdev,
  91                 bool mountpoint,
  92                 int maxdepth)
  93 {
  94         struct dirent *dent;
  95         struct timespec times[2];
  96         bool deleted = false;
  97         char *sub_path = NULL;
  98         int r = 0;
  99
 100         while ((dent = readdir(d))) {
 101                 struct stat s;
 102                 usec_t age;
 103
 104                 if (streq(dent->d_name, ".") ||
 105                     streq(dent->d_name, ".."))
 106                         continue;
 107
 108                 if (fstatat(dirfd(d), dent->d_name, &s, AT_SYMLINK_NOFOLLOW) < 0) {
 109
 110                         if (errno != ENOENT) {
 111                                 log_error("stat(%s/%s) failed: %m", p, dent->d_name);
 112                                 r = -errno;
 113                         }
 114
 115                         continue;
 116                 }
 117
 118                 /* Stay on the same filesystem */
 119                 if (s.st_dev != rootdev)
 120                         continue;
 121
 122                 /* Do not delete read-only files owned by root */
 123                 if (s.st_uid == 0 && !(s.st_mode & S_IWUSR))
 124                         continue;
 125
 126                 free(sub_path);
 127                 sub_path = NULL;
 128
 129                 if (asprintf(&sub_path, "%s/%s", p, dent->d_name) < 0) {
 130                         log_error("Out of memory");
 131                         r = -ENOMEM;
 132                         goto finish;
 133                 }
 134
 135                 /* Is there an item configured for this path? */
 136                 if (hashmap_get(items, sub_path))
 137                         continue;
 138
 139                 if (S_ISDIR(s.st_mode)) {
 140
 141                         if (mountpoint &&
 142                             streq(dent->d_name, "lost+found") &&
 143                             s.st_uid == 0)
 144                                 continue;
 145
 146                         if (maxdepth <= 0)
 147                                 log_warning("Reached max depth on %s.", sub_path);
 148                         else {
 149                                 DIR *sub_dir;
 150                                 int q;
 151
 152                                 sub_dir = xopendirat(dirfd(d), dent->d_name);
 153                                 if (sub_dir == NULL) {
 154                                         if (errno != ENOENT) {
 155                                                 log_error("opendir(%s/%s) failed: %m", p, dent->d_name);
 156                                                 r = -errno;
 157                                         }
 158
 159                                         continue;
 160                                 }
 161
 162                                 q = dir_cleanup(sub_path, sub_dir, &s, cutoff, rootdev, false, maxdepth-1);
 163                                 closedir(sub_dir);
 164
 165                                 if (q < 0)
 166                                         r = q;
 167                         }
 168
 169                         /* Ignore ctime, we change it when deleting */
 170                         age = MAX(timespec_load(&s.st_mtim),
 171                                   timespec_load(&s.st_atim));
 172                         if (age >= cutoff)
 173                                 continue;
 174
 175                         log_debug("rmdir '%s'\n", sub_path);
 176
 177                         if (unlinkat(dirfd(d), dent->d_name, AT_REMOVEDIR) < 0) {
 178                                 if (errno != ENOENT && errno != ENOTEMPTY) {
 179                                         log_error("rmdir(%s): %m", sub_path);
 180                                         r = -errno;
 181                                 }
 182                         }
 183
 184                 } else {
 185                         /* Skip files for which the sticky bit is
 186                          * set. These are semantics we define, and are
 187                          * unknown elsewhere. See XDG_RUNTIME_DIR
 188                          * specification for details. */
 189                         if (s.st_mode & S_ISVTX)
 190                                 continue;
 191
 192                         if (mountpoint) {
 193                                 if (streq(dent->d_name, ".journal") &&
 194                                     s.st_uid == 0)
 195                                         continue;
 196
 197                                 if (streq(dent->d_name, "aquota.user") ||
 198                                     streq(dent->d_name, "aquota.group"))
 199                                         continue;
 200                         }
 201
 202                         age = MAX3(timespec_load(&s.st_mtim),
 203                                    timespec_load(&s.st_atim),
 204                                    timespec_load(&s.st_ctim));
 205
 206                         if (age >= cutoff)
 207                                 continue;
 208
 209                         log_debug("unlink '%s'\n", sub_path);
 210
 211                         if (unlinkat(dirfd(d), dent->d_name, 0) < 0) {
 212                                 if (errno != ENOENT) {
 213                                         log_error("unlink(%s): %m", sub_path);
 214                                         r = -errno;
 215                                 }
 216                         }
 217
 218                         deleted = true;
 219                 }
 220         }
 221
 222 finish:
 223         if (deleted) {
 224                 /* Restore original directory timestamps */
 225                 times[0] = ds->st_atim;
 226                 times[1] = ds->st_mtim;
 227
 228                 if (futimens(dirfd(d), times) < 0)
 229                         log_error("utimensat(%s): %m", p);
 230         }
 231
 232         free(sub_path);
 233
 234         return r;
 235 }
 236
 237 static int clean_item(Item *i) {
 238         DIR *d;
 239         struct stat s, ps;
 240         bool mountpoint;
 241         int r;
 242         usec_t cutoff, n;
 243
 244         assert(i);
 245
 246         if (i->type != CREATE_DIRECTORY &&
 247             i->type != TRUNCATE_DIRECTORY &&
 248             i->type != IGNORE_PATH)
 249                 return 0;
 250
 251         if (!i->age_set || i->age <= 0)
 252                 return 0;
 253
 254         n = now(CLOCK_REALTIME);
 255         if (n < i->age)
 256                 return 0;
 257
 258         cutoff = n - i->age;
 259
 260         d = opendir(i->path);
 261         if (!d) {
 262                 if (errno == ENOENT)
 263                         return 0;
 264
 265                 log_error("Failed to open directory %s: %m", i->path);
 266                 return -errno;
 267         }
 268
 269         if (fstat(dirfd(d), &s) < 0) {
 270                 log_error("stat(%s) failed: %m", i->path);
 271                 r = -errno;
 272                 goto finish;
 273         }
 274
 275         if (!S_ISDIR(s.st_mode)) {
 276                 log_error("%s is not a directory.", i->path);
 277                 r = -ENOTDIR;
 278                 goto finish;
 279         }
 280
 281         if (fstatat(dirfd(d), "..", &ps, AT_SYMLINK_NOFOLLOW) != 0) {
 282                 log_error("stat(%s/..) failed: %m", i->path);
 283                 r = -errno;
 284                 goto finish;
 285         }
 286
 287         mountpoint = s.st_dev != ps.st_dev ||
 288                      (s.st_dev == ps.st_dev && s.st_ino == ps.st_ino);
 289
 290         r = dir_cleanup(i->path, d, &s, cutoff, s.st_dev, mountpoint, MAX_DEPTH);
 291
 292 finish:
 293         if (d)
 294                 closedir(d);
 295
 296         return r;
 297 }
 298
 299 static int create_item(Item *i) {
 300         int fd = -1, r;
 301         mode_t u;
 302         struct stat st;
 303
 304         assert(i);
 305
 306         switch (i->type) {
 307
 308         case IGNORE_PATH:
 309         case REMOVE_PATH:
 310         case RECURSIVE_REMOVE_PATH:
 311                 return 0;
 312
 313         case CREATE_FILE:
 314         case TRUNCATE_FILE:
 315
 316                 u = umask(0);
 317                 fd = open(i->path, O_CREAT|O_NDELAY|O_CLOEXEC|O_WRONLY|O_NOCTTY|O_NOFOLLOW|
 318                           (i->type == TRUNCATE_FILE ? O_TRUNC : 0), i->mode);
 319                 umask(u);
 320
 321                 if (fd < 0) {
 322                         log_error("Failed to create file %s: %m", i->path);
 323                         r = -errno;
 324                         goto finish;
 325                 }
 326
 327                 if (fstat(fd, &st) < 0) {
 328                         log_error("stat(%s) failed: %m", i->path);
 329                         r = -errno;
 330                         goto finish;
 331                 }
 332
 333                 if (!S_ISREG(st.st_mode)) {
 334                         log_error("%s is not a file.", i->path);
 335                         r = -EEXIST;
 336                         goto finish;
 337                 }
 338
 339                 if (i->mode_set)
 340                         if (fchmod(fd, i->mode) < 0) {
 341                                 log_error("chmod(%s) failed: %m", i->path);
 342                                 r = -errno;
 343                                 goto finish;
 344                         }
 345
 346                 if (i->uid_set || i->gid_set)
 347                         if (fchown(fd,
 348                                    i->uid_set ? i->uid : (uid_t) -1,
 349                                    i->gid_set ? i->gid : (gid_t) -1) < 0) {
 350                                 log_error("chown(%s) failed: %m", i->path);
 351                                 r = -errno;
 352                                 goto finish;
 353                         }
 354
 355                 break;
 356
 357         case TRUNCATE_DIRECTORY:
 358         case CREATE_DIRECTORY:
 359
 360                 u = umask(0);
 361                 r = mkdir(i->path, i->mode);
 362                 umask(u);
 363
 364                 if (r < 0 && errno != EEXIST) {
 365                         log_error("Failed to create directory %s: %m", i->path);
 366                         r = -errno;
 367                         goto finish;
 368                 }
 369
 370                 if (stat(i->path, &st) < 0) {
 371                         log_error("stat(%s) failed: %m", i->path);
 372                         r = -errno;
 373                         goto finish;
 374                 }
 375
 376                 if (!S_ISDIR(st.st_mode)) {
 377                         log_error("%s is not a directory.", i->path);
 378                         r = -EEXIST;
 379                         goto finish;
 380                 }
 381
 382                 if (i->mode_set)
 383                         if (chmod(i->path, i->mode) < 0) {
 384                                 log_error("chmod(%s) failed: %m", i->path);
 385                                 r = -errno;
 386                                 goto finish;
 387                         }
 388
 389                 if (i->uid_set || i->gid_set)
 390                         if (chown(i->path,
 391                                   i->uid_set ? i->uid : (uid_t) -1,
 392                                   i->gid_set ? i->gid : (gid_t) -1) < 0) {
 393
 394                                 log_error("chown(%s) failed: %m", i->path);
 395                                 r = -errno;
 396                                 goto finish;
 397                         }
 398
 399                 break;
 400         }
 401
 402         if ((r = label_fix(i->path)) < 0)
 403                 goto finish;
 404
 405         log_debug("%s created successfully.", i->path);
 406
 407 finish:
 408         if (fd >= 0)
 409                 close_nointr_nofail(fd);
 410
 411         return r;
 412 }
 413
 414 static int remove_item(Item *i) {
 415         int r;
 416
 417         assert(i);
 418
 419         switch (i->type) {
 420
 421         case CREATE_FILE:
 422         case TRUNCATE_FILE:
 423         case CREATE_DIRECTORY:
 424         case IGNORE_PATH:
 425                 break;
 426
 427         case REMOVE_PATH:
 428                 if (remove(i->path) < 0 && errno != ENOENT) {
 429                         log_error("remove(%s): %m", i->path);
 430                         return -errno;
 431                 }
 432
 433                 break;
 434
 435         case TRUNCATE_DIRECTORY:
 436         case RECURSIVE_REMOVE_PATH:
 437                 if ((r = rm_rf(i->path, false, i->type == RECURSIVE_REMOVE_PATH)) < 0 &&
 438                     r != -ENOENT) {
 439                         log_error("rm_rf(%s): %s", i->path, strerror(-r));
 440                         return r;
 441                 }
 442
 443                 break;
 444         }
 445
 446         return 0;
 447 }
 448
 449 static int process_item(Item *i) {
 450         int r, q, p;
 451
 452         assert(i);
 453
 454         r = arg_create ? create_item(i) : 0;
 455         q = arg_remove ? remove_item(i) : 0;
 456         p = arg_clean ? clean_item(i) : 0;
 457
 458         if (r < 0)
 459                 return r;
 460
 461         if (q < 0)
 462                 return q;
 463
 464         return p;
 465 }
 466
 467 static void item_free(Item *i) {
 468         assert(i);
 469
 470         free(i->path);
 471         free(i);
 472 }
 473
 474 static int parse_line(const char *fname, unsigned line, const char *buffer, const char *prefix) {
 475         Item *i;
 476         char *mode = NULL, *user = NULL, *group = NULL, *age = NULL;
 477         int r, n;
 478
 479         assert(fname);
 480         assert(line >= 1);
 481         assert(buffer);
 482
 483         if (!(i = new0(Item, 1))) {
 484                 log_error("Out of memory");
 485                 return -ENOMEM;
 486         }
 487
 488         if ((n = sscanf(buffer,
 489                         "%c "
 490                         "%ms "
 491                         "%ms "
 492                         "%ms "
 493                         "%ms "
 494                         "%ms",
 495                         &i->type,
 496                         &i->path,
 497                         &mode,
 498                         &user,
 499                         &group,
 500                         &age)) < 2) {
 501                 log_error("[%s:%u] Syntax error.", fname, line);
 502                 r = -EIO;
 503                 goto finish;
 504         }
 505
 506         if (i->type != CREATE_FILE &&
 507             i->type != TRUNCATE_FILE &&
 508             i->type != CREATE_DIRECTORY &&
 509             i->type != TRUNCATE_DIRECTORY &&
 510             i->type != IGNORE_PATH &&
 511             i->type != REMOVE_PATH &&
 512             i->type != RECURSIVE_REMOVE_PATH) {
 513                 log_error("[%s:%u] Unknown file type '%c'.", fname, line, i->type);
 514                 r = -EBADMSG;
 515                 goto finish;
 516         }
 517
 518         if (!path_is_absolute(i->path)) {
 519                 log_error("[%s:%u] Path '%s' not absolute.", fname, line, i->path);
 520                 r = -EBADMSG;
 521                 goto finish;
 522         }
 523
 524         path_kill_slashes(i->path);
 525
 526         if (prefix && !path_startswith(i->path, prefix)) {
 527                 r = 0;
 528                 goto finish;
 529         }
 530
 531         if (user && !streq(user, "-")) {
 532                 unsigned long lu;
 533                 struct passwd *p;
 534
 535                 if (streq(user, "root") || streq(user, "0"))
 536                         i->uid = 0;
 537                 else if (safe_atolu(user, &lu) >= 0)
 538                         i->uid = (uid_t) lu;
 539                 else if ((p = getpwnam(user)))
 540                         i->uid = p->pw_uid;
 541                 else {
 542                         log_error("[%s:%u] Unknown user '%s'.", fname, line, user);
 543                         r = -ENOENT;
 544                         goto finish;
 545                 }
 546
 547                 i->uid_set = true;
 548         }
 549
 550         if (group && !streq(group, "-")) {
 551                 unsigned long lu;
 552                 struct group *g;
 553
 554                 if (streq(group, "root") || streq(group, "0"))
 555                         i->gid = 0;
 556                 else if (safe_atolu(group, &lu) >= 0)
 557                         i->gid = (gid_t) lu;
 558                 else if ((g = getgrnam(group)))
 559                         i->gid = g->gr_gid;
 560                 else {
 561                         log_error("[%s:%u] Unknown group '%s'.", fname, line, group);
 562                         r = -ENOENT;
 563                         goto finish;
 564                 }
 565
 566                 i->gid_set = true;
 567         }
 568
 569         if (mode && !streq(mode, "-")) {
 570                 unsigned m;
 571
 572                 if (sscanf(mode, "%o", &m) != 1) {
 573                         log_error("[%s:%u] Invalid mode '%s'.", fname, line, mode);
 574                         r = -ENOENT;
 575                         goto finish;
 576                 }
 577
 578                 i->mode = m;
 579                 i->mode_set = true;
 580         } else
 581                 i->mode = i->type == CREATE_DIRECTORY ? 0755 : 0644;
 582
 583         if (age && !streq(age, "-")) {
 584                 if (parse_usec(age, &i->age) < 0) {
 585                         log_error("[%s:%u] Invalid age '%s'.", fname, line, age);
 586                         r = -EBADMSG;
 587                         goto finish;
 588                 }
 589
 590                 i->age_set = true;
 591         }
 592
 593         if ((r = hashmap_put(items, i->path, i)) < 0) {
 594                 log_error("Failed to insert item %s: %s", i->path, strerror(-r));
 595                 goto finish;
 596         }
 597
 598         i = NULL;
 599         r = 0;
 600
 601 finish:
 602         free(user);
 603         free(group);
 604         free(mode);
 605         free(age);
 606
 607         if (i)
 608                 item_free(i);
 609
 610         return r;
 611 }
 612
 613 static int scandir_filter(const struct dirent *d) {
 614         assert(d);
 615
 616         if (ignore_file(d->d_name))
 617                 return 0;
 618
 619         if (d->d_type != DT_REG &&
 620             d->d_type != DT_LNK)
 621                 return 0;
 622
 623         return endswith(d->d_name, ".conf");
 624 }
 625
 626 static int help(void) {
 627
 628         printf("%s [OPTIONS...]\n\n"
 629                "Create and clean up temporary directories.\n\n"
 630                "  -h --help             Show this help\n"
 631                "     --create           Create marked files/directories\n"
 632                "     --clean            Clean up marked directories\n"
 633                "     --remove           Remove marked files/directories\n",
 634                program_invocation_short_name);
 635
 636         return 0;
 637 }
 638
 639 static int parse_argv(int argc, char *argv[]) {
 640
 641         enum {
 642                 ARG_CREATE,
 643                 ARG_CLEAN,
 644                 ARG_REMOVE
 645         };
 646
 647         static const struct option options[] = {
 648                 { "help",      no_argument,       NULL, 'h'           },
 649                 { "create",    no_argument,       NULL, ARG_CREATE    },
 650                 { "clean",     no_argument,       NULL, ARG_CLEAN     },
 651                 { "remove",    no_argument,       NULL, ARG_REMOVE    },
 652                 { NULL,        0,                 NULL, 0             }
 653         };
 654
 655         int c;
 656
 657         assert(argc >= 0);
 658         assert(argv);
 659
 660         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
 661
 662                 switch (c) {
 663
 664                 case 'h':
 665                         help();
 666                         return 0;
 667
 668                 case ARG_CREATE:
 669                         arg_create = true;
 670                         break;
 671
 672                 case ARG_CLEAN:
 673                         arg_clean = true;
 674                         break;
 675
 676                 case ARG_REMOVE:
 677                         arg_remove = true;
 678                         break;
 679
 680                 case '?':
 681                         return -EINVAL;
 682
 683                 default:
 684                         log_error("Unknown option code %c", c);
 685                         return -EINVAL;
 686                 }
 687         }
 688
 689         if (!arg_clean && !arg_create && !arg_remove) {
 690                 help();
 691                 return -EINVAL;
 692         }
 693
 694         return 1;
 695 }
 696
 697 int main(int argc, char *argv[]) {
 698         struct dirent **de = NULL;
 699         int r, n, j;
 700         const char *prefix = NULL;
 701         Item *i;
 702         Iterator iterator;
 703
 704         if ((r = parse_argv(argc, argv)) <= 0)
 705                 return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 706
 707         if (optind < argc)
 708                 prefix = argv[optind];
 709         else
 710                 prefix = "/";
 711
 712         log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
 713         log_parse_environment();
 714         log_open();
 715
 716         label_init();
 717
 718         if (!(items = hashmap_new(string_hash_func, string_compare_func))) {
 719                 log_error("Out of memory");
 720                 r = EXIT_FAILURE;
 721                 goto finish;
 722         }
 723
 724         if ((n = scandir("/etc/tmpfiles.d/", &de, scandir_filter, alphasort)) < 0) {
 725
 726                 if (errno == ENOENT)
 727                         r = EXIT_SUCCESS;
 728                 else {
 729                         log_error("Failed to enumerate /etc/tmpfiles.d/ files: %m");
 730                         r = EXIT_FAILURE;
 731                 }
 732
 733                 goto finish;
 734         }
 735
 736         r = EXIT_SUCCESS;
 737
 738         for (j = 0; j < n; j++) {
 739                 int k;
 740                 char *fn;
 741                 FILE *f;
 742                 unsigned v;
 743
 744                 k = asprintf(&fn, "/etc/tmpfiles.d/%s", de[j]->d_name);
 745                 free(de[j]);
 746
 747                 if (k < 0) {
 748                         log_error("Failed to allocate file name.");
 749                         r = EXIT_FAILURE;
 750                         continue;
 751                 }
 752
 753                 if (!(f = fopen(fn, "re"))) {
 754
 755                         if (errno != ENOENT) {
 756                                 log_error("Failed to open %s: %m", fn);
 757                                 r = EXIT_FAILURE;
 758                         }
 759
 760                         free(fn);
 761                         continue;
 762                 }
 763
 764                 v = 0;
 765                 for (;;) {
 766                         char line[LINE_MAX], *l;
 767
 768                         if (!(fgets(line, sizeof(line), f)))
 769                                 break;
 770
 771                         v++;
 772
 773                         l = strstrip(line);
 774                         if (*l == '#' || *l == 0)
 775                                 continue;
 776
 777                         if (parse_line(fn, v, l, prefix) < 0)
 778                                 r = EXIT_FAILURE;
 779                 }
 780
 781                 if (ferror(f)) {
 782                         r = EXIT_FAILURE;
 783                         log_error("Failed to read from file %s: %m", fn);
 784                 }
 785
 786                 free(fn);
 787
 788                 fclose(f);
 789         }
 790
 791         free(de);
 792
 793         HASHMAP_FOREACH(i, items, iterator)
 794                 if (process_item(i) < 0)
 795                         r = EXIT_FAILURE;
 796
 797 finish:
 798         while ((i = hashmap_steal_first(items)))
 799                 item_free(i);
 800
 801         hashmap_free(items);
 802
 803         label_finish();
 804
 805         return r;
 806 }