src/fstab-generator/fstab-generator.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <stdio.h>
   5 #include <unistd.h>
   6
   7 #include "alloc-util.h"
   8 #include "chase-symlinks.h"
   9 #include "fd-util.h"
  10 #include "fileio.h"
  11 #include "fstab-util.h"
  12 #include "generator.h"
  13 #include "in-addr-util.h"
  14 #include "log.h"
  15 #include "main-func.h"
  16 #include "mkdir.h"
  17 #include "mount-setup.h"
  18 #include "mount-util.h"
  19 #include "mountpoint-util.h"
  20 #include "parse-util.h"
  21 #include "path-util.h"
  22 #include "proc-cmdline.h"
  23 #include "special.h"
  24 #include "specifier.h"
  25 #include "stat-util.h"
  26 #include "string-util.h"
  27 #include "strv.h"
  28 #include "unit-name.h"
  29 #include "util.h"
  30 #include "virt.h"
  31 #include "volatile-util.h"
  32
  33 typedef enum MountPointFlags {
  34         MOUNT_NOAUTO    = 1 << 0,
  35         MOUNT_NOFAIL    = 1 << 1,
  36         MOUNT_AUTOMOUNT = 1 << 2,
  37         MOUNT_MAKEFS    = 1 << 3,
  38         MOUNT_GROWFS    = 1 << 4,
  39         MOUNT_RW_ONLY   = 1 << 5,
  40 } MountPointFlags;
  41
  42 static const char *arg_dest = NULL;
  43 static const char *arg_dest_late = NULL;
  44 static bool arg_fstab_enabled = true;
  45 static bool arg_swap_enabled = true;
  46 static char *arg_root_what = NULL;
  47 static char *arg_root_fstype = NULL;
  48 static char *arg_root_options = NULL;
  49 static char *arg_root_hash = NULL;
  50 static int arg_root_rw = -1;
  51 static char *arg_usr_what = NULL;
  52 static char *arg_usr_fstype = NULL;
  53 static char *arg_usr_options = NULL;
  54 static char *arg_usr_hash = NULL;
  55 static VolatileMode arg_volatile_mode = _VOLATILE_MODE_INVALID;
  56
  57 STATIC_DESTRUCTOR_REGISTER(arg_root_what, freep);
  58 STATIC_DESTRUCTOR_REGISTER(arg_root_fstype, freep);
  59 STATIC_DESTRUCTOR_REGISTER(arg_root_options, freep);
  60 STATIC_DESTRUCTOR_REGISTER(arg_root_hash, freep);
  61 STATIC_DESTRUCTOR_REGISTER(arg_usr_what, freep);
  62 STATIC_DESTRUCTOR_REGISTER(arg_usr_fstype, freep);
  63 STATIC_DESTRUCTOR_REGISTER(arg_usr_options, freep);
  64 STATIC_DESTRUCTOR_REGISTER(arg_usr_hash, freep);
  65
  66 static int write_options(FILE *f, const char *options) {
  67         _cleanup_free_ char *o = NULL;
  68
  69         if (isempty(options))
  70                 return 0;
  71
  72         if (streq(options, "defaults"))
  73                 return 0;
  74
  75         o = specifier_escape(options);
  76         if (!o)
  77                 return log_oom();
  78
  79         fprintf(f, "Options=%s\n", o);
  80         return 1;
  81 }
  82
  83 static int write_what(FILE *f, const char *what) {
  84         _cleanup_free_ char *w = NULL;
  85
  86         w = specifier_escape(what);
  87         if (!w)
  88                 return log_oom();
  89
  90         fprintf(f, "What=%s\n", w);
  91         return 1;
  92 }
  93
  94 static int add_swap(
  95                 const char *what,
  96                 struct mntent *me,
  97                 MountPointFlags flags) {
  98
  99         _cleanup_free_ char *name = NULL;
 100         _cleanup_fclose_ FILE *f = NULL;
 101         int r;
 102
 103         assert(what);
 104         assert(me);
 105
 106         if (!arg_swap_enabled) {
 107                 log_info("Swap unit generation disabled on kernel command line, ignoring fstab swap entry for %s.", what);
 108                 return 0;
 109         }
 110
 111         if (access("/proc/swaps", F_OK) < 0) {
 112                 log_info("Swap not supported, ignoring fstab swap entry for %s.", what);
 113                 return 0;
 114         }
 115
 116         if (detect_container() > 0) {
 117                 log_info("Running in a container, ignoring fstab swap entry for %s.", what);
 118                 return 0;
 119         }
 120
 121         r = unit_name_from_path(what, ".swap", &name);
 122         if (r < 0)
 123                 return log_error_errno(r, "Failed to generate unit name: %m");
 124
 125         r = generator_open_unit_file(arg_dest, fstab_path(), name, &f);
 126         if (r < 0)
 127                 return r;
 128
 129         fprintf(f,
 130                 "[Unit]\n"
 131                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n"
 132                 "SourcePath=%s\n",
 133                 fstab_path());
 134
 135         r = generator_write_blockdev_dependency(f, what);
 136         if (r < 0)
 137                 return r;
 138
 139         fprintf(f,
 140                 "\n"
 141                 "[Swap]\n");
 142
 143         r = write_what(f, what);
 144         if (r < 0)
 145                 return r;
 146
 147         r = write_options(f, me->mnt_opts);
 148         if (r < 0)
 149                 return r;
 150
 151         r = fflush_and_check(f);
 152         if (r < 0)
 153                 return log_error_errno(r, "Failed to write unit file %s: %m", name);
 154
 155         /* use what as where, to have a nicer error message */
 156         r = generator_write_timeouts(arg_dest, what, what, me->mnt_opts, NULL);
 157         if (r < 0)
 158                 return r;
 159
 160         if (flags & MOUNT_MAKEFS) {
 161                 r = generator_hook_up_mkswap(arg_dest, what);
 162                 if (r < 0)
 163                         return r;
 164         }
 165
 166         if (flags & MOUNT_GROWFS)
 167                 /* TODO: swap devices must be wiped and recreated */
 168                 log_warning("%s: growing swap devices is currently unsupported.", what);
 169
 170         if (!(flags & MOUNT_NOAUTO)) {
 171                 r = generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET,
 172                                           (flags & MOUNT_NOFAIL) ? "wants" : "requires", name);
 173                 if (r < 0)
 174                         return r;
 175         }
 176
 177         return 0;
 178 }
 179
 180 static bool mount_is_network(struct mntent *me) {
 181         assert(me);
 182
 183         return fstab_test_option(me->mnt_opts, "_netdev\0") ||
 184                fstype_is_network(me->mnt_type);
 185 }
 186
 187 static bool mount_in_initrd(struct mntent *me) {
 188         assert(me);
 189
 190         return fstab_test_option(me->mnt_opts, "x-initrd.mount\0") ||
 191                streq(me->mnt_dir, "/usr");
 192 }
 193
 194 static int write_timeout(
 195                 FILE *f,
 196                 const char *where,
 197                 const char *opts,
 198                 const char *filter,
 199                 const char *variable) {
 200
 201         _cleanup_free_ char *timeout = NULL;
 202         usec_t u;
 203         int r;
 204
 205         r = fstab_filter_options(opts, filter, NULL, &timeout, NULL, NULL);
 206         if (r < 0)
 207                 return log_warning_errno(r, "Failed to parse options: %m");
 208         if (r == 0)
 209                 return 0;
 210
 211         r = parse_sec_fix_0(timeout, &u);
 212         if (r < 0) {
 213                 log_warning("Failed to parse timeout for %s, ignoring: %s", where, timeout);
 214                 return 0;
 215         }
 216
 217         fprintf(f, "%s=%s\n", variable, FORMAT_TIMESPAN(u, 0));
 218
 219         return 0;
 220 }
 221
 222 static int write_idle_timeout(FILE *f, const char *where, const char *opts) {
 223         return write_timeout(f, where, opts,
 224                              "x-systemd.idle-timeout\0", "TimeoutIdleSec");
 225 }
 226
 227 static int write_mount_timeout(FILE *f, const char *where, const char *opts) {
 228         return write_timeout(f, where, opts,
 229                              "x-systemd.mount-timeout\0", "TimeoutSec");
 230 }
 231
 232 static int write_dependency(
 233                 FILE *f,
 234                 const char *opts,
 235                 const char *filter,
 236                 const char *format) {
 237
 238         _cleanup_strv_free_ char **names = NULL, **units = NULL;
 239         _cleanup_free_ char *res = NULL;
 240         char **s;
 241         int r;
 242
 243         assert(f);
 244         assert(opts);
 245
 246         r = fstab_filter_options(opts, filter, NULL, NULL, &names, NULL);
 247         if (r < 0)
 248                 return log_warning_errno(r, "Failed to parse options: %m");
 249         if (r == 0)
 250                 return 0;
 251
 252         STRV_FOREACH(s, names) {
 253                 char *x;
 254
 255                 r = unit_name_mangle_with_suffix(*s, "as dependency", 0, ".mount", &x);
 256                 if (r < 0)
 257                         return log_error_errno(r, "Failed to generate unit name: %m");
 258
 259                 r = strv_consume(&units, x);
 260                 if (r < 0)
 261                         return log_oom();
 262         }
 263
 264         if (units) {
 265                 res = strv_join(units, " ");
 266                 if (!res)
 267                         return log_oom();
 268
 269                 DISABLE_WARNING_FORMAT_NONLITERAL;
 270                 fprintf(f, format, res);
 271                 REENABLE_WARNING;
 272         }
 273
 274         return 0;
 275 }
 276
 277 static int write_after(FILE *f, const char *opts) {
 278         return write_dependency(f, opts,
 279                                 "x-systemd.after\0", "After=%1$s\n");
 280 }
 281
 282 static int write_requires_after(FILE *f, const char *opts) {
 283         return write_dependency(f, opts,
 284                                 "x-systemd.requires\0", "After=%1$s\nRequires=%1$s\n");
 285 }
 286
 287 static int write_before(FILE *f, const char *opts) {
 288         return write_dependency(f, opts,
 289                                 "x-systemd.before\0", "Before=%1$s\n");
 290 }
 291
 292 static int write_requires_mounts_for(FILE *f, const char *opts) {
 293         _cleanup_strv_free_ char **paths = NULL, **paths_escaped = NULL;
 294         _cleanup_free_ char *res = NULL;
 295         int r;
 296
 297         assert(f);
 298         assert(opts);
 299
 300         r = fstab_filter_options(opts, "x-systemd.requires-mounts-for\0", NULL, NULL, &paths, NULL);
 301         if (r < 0)
 302                 return log_warning_errno(r, "Failed to parse options: %m");
 303         if (r == 0)
 304                 return 0;
 305
 306         r = specifier_escape_strv(paths, &paths_escaped);
 307         if (r < 0)
 308                 return log_error_errno(r, "Failed to escape paths: %m");
 309
 310         res = strv_join(paths_escaped, " ");
 311         if (!res)
 312                 return log_oom();
 313
 314         fprintf(f, "RequiresMountsFor=%s\n", res);
 315
 316         return 0;
 317 }
 318
 319 static int write_extra_dependencies(FILE *f, const char *opts) {
 320         int r;
 321
 322         assert(f);
 323
 324         if (opts) {
 325                 r = write_after(f, opts);
 326                 if (r < 0)
 327                         return r;
 328                 r = write_requires_after(f, opts);
 329                 if (r < 0)
 330                         return r;
 331                 r = write_before(f, opts);
 332                 if (r < 0)
 333                         return r;
 334                 r = write_requires_mounts_for(f, opts);
 335                 if (r < 0)
 336                         return r;
 337         }
 338
 339         return 0;
 340 }
 341
 342 static int add_mount(
 343                 const char *dest,
 344                 const char *what,
 345                 const char *where,
 346                 const char *original_where,
 347                 const char *fstype,
 348                 const char *opts,
 349                 int passno,
 350                 MountPointFlags flags,
 351                 const char *post,
 352                 const char *source) {
 353
 354         _cleanup_free_ char
 355                 *name = NULL,
 356                 *automount_name = NULL,
 357                 *filtered = NULL,
 358                 *where_escaped = NULL;
 359         _cleanup_strv_free_ char **wanted_by = NULL, **required_by = NULL;
 360         _cleanup_fclose_ FILE *f = NULL;
 361         int r;
 362
 363         assert(what);
 364         assert(where);
 365         assert(opts);
 366         assert(post);
 367         assert(source);
 368
 369         if (streq_ptr(fstype, "autofs"))
 370                 return 0;
 371
 372         if (!is_path(where)) {
 373                 log_warning("Mount point %s is not a valid path, ignoring.", where);
 374                 return 0;
 375         }
 376
 377         if (mount_point_is_api(where) ||
 378             mount_point_ignore(where))
 379                 return 0;
 380
 381         r = fstab_filter_options(opts, "x-systemd.wanted-by\0", NULL, NULL, &wanted_by, NULL);
 382         if (r < 0)
 383                 return r;
 384
 385         r = fstab_filter_options(opts, "x-systemd.required-by\0", NULL, NULL, &required_by, NULL);
 386         if (r < 0)
 387                 return r;
 388
 389         if (path_equal(where, "/")) {
 390                 if (flags & MOUNT_NOAUTO)
 391                         log_warning("Ignoring \"noauto\" option for root device");
 392                 if (flags & MOUNT_NOFAIL)
 393                         log_warning("Ignoring \"nofail\" option for root device");
 394                 if (flags & MOUNT_AUTOMOUNT)
 395                         log_warning("Ignoring \"automount\" option for root device");
 396                 if (!strv_isempty(wanted_by))
 397                         log_warning("Ignoring \"x-systemd.wanted-by=\" option for root device");
 398                 if (!strv_isempty(required_by))
 399                         log_warning("Ignoring \"x-systemd.required-by=\" option for root device");
 400
 401                 required_by = strv_free(required_by);
 402                 wanted_by = strv_free(wanted_by);
 403                 SET_FLAG(flags, MOUNT_NOAUTO | MOUNT_NOFAIL | MOUNT_AUTOMOUNT, false);
 404         }
 405
 406         r = unit_name_from_path(where, ".mount", &name);
 407         if (r < 0)
 408                 return log_error_errno(r, "Failed to generate unit name: %m");
 409
 410         r = generator_open_unit_file(dest, fstab_path(), name, &f);
 411         if (r < 0)
 412                 return r;
 413
 414         fprintf(f,
 415                 "[Unit]\n"
 416                 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n"
 417                 "SourcePath=%s\n",
 418                 source);
 419
 420         if (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !(flags & MOUNT_AUTOMOUNT) &&
 421             fstab_test_yes_no_option(opts, "bg\0" "fg\0")) {
 422                 /* The default retry timeout that mount.nfs uses for 'bg' mounts
 423                  * is 10000 minutes, where as it uses 2 minutes for 'fg' mounts.
 424                  * As we are making  'bg' mounts look like an 'fg' mount to
 425                  * mount.nfs (so systemd can manage the job-control aspects of 'bg'),
 426                  * we need to explicitly preserve that default, and also ensure
 427                  * the systemd mount-timeout doesn't interfere.
 428                  * By placing these options first, they can be overridden by
 429                  * settings in /etc/fstab. */
 430                 opts = strjoina("x-systemd.mount-timeout=infinity,retry=10000,nofail,", opts, ",fg");
 431                 SET_FLAG(flags, MOUNT_NOFAIL, true);
 432         }
 433
 434         r = write_extra_dependencies(f, opts);
 435         if (r < 0)
 436                 return r;
 437
 438         /* Order the mount unit we generate relative to the post unit, so that DefaultDependencies= on the
 439          * target unit won't affect us. */
 440         if (post && !FLAGS_SET(flags, MOUNT_NOFAIL))
 441                 fprintf(f, "Before=%s\n", post);
 442
 443         if (passno != 0) {
 444                 r = generator_write_fsck_deps(f, dest, what, where, fstype);
 445                 if (r < 0)
 446                         return r;
 447         }
 448
 449         r = generator_write_blockdev_dependency(f, what);
 450         if (r < 0)
 451                 return r;
 452
 453         fprintf(f,
 454                 "\n"
 455                 "[Mount]\n");
 456
 457         r = write_what(f, what);
 458         if (r < 0)
 459                 return r;
 460
 461         if (original_where)
 462                 fprintf(f, "# Canonicalized from %s\n", original_where);
 463
 464         where_escaped = specifier_escape(where);
 465         if (!where_escaped)
 466                 return log_oom();
 467         fprintf(f, "Where=%s\n", where_escaped);
 468
 469         if (!isempty(fstype) && !streq(fstype, "auto")) {
 470                 _cleanup_free_ char *t = NULL;
 471
 472                 t = specifier_escape(fstype);
 473                 if (!t)
 474                         return -ENOMEM;
 475
 476                 fprintf(f, "Type=%s\n", t);
 477         }
 478
 479         r = generator_write_timeouts(dest, what, where, opts, &filtered);
 480         if (r < 0)
 481                 return r;
 482
 483         r = generator_write_device_deps(dest, what, where, opts);
 484         if (r < 0)
 485                 return r;
 486
 487         r = write_mount_timeout(f, where, opts);
 488         if (r < 0)
 489                 return r;
 490
 491         r = write_options(f, filtered);
 492         if (r < 0)
 493                 return r;
 494
 495         if (flags & MOUNT_RW_ONLY)
 496                 fprintf(f, "ReadWriteOnly=yes\n");
 497
 498         r = fflush_and_check(f);
 499         if (r < 0)
 500                 return log_error_errno(r, "Failed to write unit file %s: %m", name);
 501
 502         if (flags & MOUNT_MAKEFS) {
 503                 r = generator_hook_up_mkfs(dest, what, where, fstype);
 504                 if (r < 0)
 505                         return r;
 506         }
 507
 508         if (flags & MOUNT_GROWFS) {
 509                 r = generator_hook_up_growfs(dest, where, post);
 510                 if (r < 0)
 511                         return r;
 512         }
 513
 514         if (!FLAGS_SET(flags, MOUNT_AUTOMOUNT)) {
 515                 if (!FLAGS_SET(flags, MOUNT_NOAUTO) && strv_isempty(wanted_by) && strv_isempty(required_by)) {
 516                         r = generator_add_symlink(dest, post,
 517                                                   (flags & MOUNT_NOFAIL) ? "wants" : "requires", name);
 518                         if (r < 0)
 519                                 return r;
 520                 } else {
 521                         char **s;
 522
 523                         STRV_FOREACH(s, wanted_by) {
 524                                 r = generator_add_symlink(dest, *s, "wants", name);
 525                                 if (r < 0)
 526                                         return r;
 527                         }
 528
 529                         STRV_FOREACH(s, required_by) {
 530                                 r = generator_add_symlink(dest, *s, "requires", name);
 531                                 if (r < 0)
 532                                         return r;
 533                         }
 534                 }
 535         } else {
 536                 r = unit_name_from_path(where, ".automount", &automount_name);
 537                 if (r < 0)
 538                         return log_error_errno(r, "Failed to generate unit name: %m");
 539
 540                 f = safe_fclose(f);
 541
 542                 r = generator_open_unit_file(dest, fstab_path(), automount_name, &f);
 543                 if (r < 0)
 544                         return r;
 545
 546                 fprintf(f,
 547                         "[Unit]\n"
 548                         "SourcePath=%s\n"
 549                         "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
 550                         source);
 551
 552                 fprintf(f,
 553                         "\n"
 554                         "[Automount]\n"
 555                         "Where=%s\n",
 556                         where_escaped);
 557
 558                 r = write_idle_timeout(f, where, opts);
 559                 if (r < 0)
 560                         return r;
 561
 562                 r = fflush_and_check(f);
 563                 if (r < 0)
 564                         return log_error_errno(r, "Failed to write unit file %s: %m", automount_name);
 565
 566                 r = generator_add_symlink(dest, post,
 567                                           (flags & MOUNT_NOFAIL) ? "wants" : "requires", automount_name);
 568                 if (r < 0)
 569                         return r;
 570         }
 571
 572         return 0;
 573 }
 574
 575 static int parse_fstab(bool initrd) {
 576         _cleanup_endmntent_ FILE *f = NULL;
 577         const char *fstab;
 578         struct mntent *me;
 579         int r = 0;
 580
 581         fstab = initrd ? "/sysroot/etc/fstab" : fstab_path();
 582         log_debug("Parsing %s...", fstab);
 583
 584         f = setmntent(fstab, "re");
 585         if (!f) {
 586                 if (errno == ENOENT)
 587                         return 0;
 588
 589                 return log_error_errno(errno, "Failed to open %s: %m", fstab);
 590         }
 591
 592         while ((me = getmntent(f))) {
 593                 _cleanup_free_ char *where = NULL, *what = NULL, *canonical_where = NULL;
 594                 bool makefs, growfs, noauto, nofail;
 595                 MountPointFlags flags;
 596                 int k;
 597
 598                 if (initrd && !mount_in_initrd(me))
 599                         continue;
 600
 601                 what = fstab_node_to_udev_node(me->mnt_fsname);
 602                 if (!what)
 603                         return log_oom();
 604
 605                 if (path_is_read_only_fs("/sys") > 0) {
 606                         if (streq(what, "sysfs")) {
 607                                 log_info("Running in a container, ignoring fstab entry for %s.", what);
 608                                 continue;
 609                         }
 610
 611                         if (is_device_path(what)) {
 612                                 log_info("Running in a container, ignoring fstab device entry for %s.", what);
 613                                 continue;
 614                         }
 615                 }
 616
 617                 where = strdup(me->mnt_dir);
 618                 if (!where)
 619                         return log_oom();
 620
 621                 if (is_path(where)) {
 622                         path_simplify(where);
 623
 624                         /* Follow symlinks here; see 5261ba901845c084de5a8fd06500ed09bfb0bd80 which makes sense for
 625                          * mount units, but causes problems since it historically worked to have symlinks in e.g.
 626                          * /etc/fstab. So we canonicalize here. Note that we use CHASE_NONEXISTENT to handle the case
 627                          * where a symlink refers to another mount target; this works assuming the sub-mountpoint
 628                          * target is the final directory. */
 629                         k = chase_symlinks(where, initrd ? "/sysroot" : NULL,
 630                                            CHASE_PREFIX_ROOT | CHASE_NONEXISTENT,
 631                                            &canonical_where, NULL);
 632                         if (k < 0) /* If we can't canonicalize we continue on as if it wasn't a symlink */
 633                                 log_debug_errno(k, "Failed to read symlink target for %s, ignoring: %m", where);
 634                         else if (streq(canonical_where, where)) /* If it was fully canonicalized, suppress the change */
 635                                 canonical_where = mfree(canonical_where);
 636                         else
 637                                 log_debug("Canonicalized what=%s where=%s to %s", what, where, canonical_where);
 638                 }
 639
 640                 makefs = fstab_test_option(me->mnt_opts, "x-systemd.makefs\0");
 641                 growfs = fstab_test_option(me->mnt_opts, "x-systemd.growfs\0");
 642                 noauto = fstab_test_yes_no_option(me->mnt_opts, "noauto\0" "auto\0");
 643                 nofail = fstab_test_yes_no_option(me->mnt_opts, "nofail\0" "fail\0");
 644
 645                 log_debug("Found entry what=%s where=%s type=%s makefs=%s growfs=%s noauto=%s nofail=%s",
 646                           what, where, me->mnt_type,
 647                           yes_no(makefs), yes_no(growfs),
 648                           yes_no(noauto), yes_no(nofail));
 649
 650                 flags = makefs * MOUNT_MAKEFS |
 651                         growfs * MOUNT_GROWFS |
 652                         noauto * MOUNT_NOAUTO |
 653                         nofail * MOUNT_NOFAIL;
 654
 655                 if (streq(me->mnt_type, "swap"))
 656                         k = add_swap(what, me, flags);
 657                 else {
 658                         bool rw_only, automount;
 659                         const char *post;
 660
 661                         rw_only = fstab_test_option(me->mnt_opts, "x-systemd.rw-only\0");
 662                         automount = fstab_test_option(me->mnt_opts,
 663                                                       "comment=systemd.automount\0"
 664                                                       "x-systemd.automount\0");
 665
 666                         flags |= rw_only * MOUNT_RW_ONLY |
 667                                  automount * MOUNT_AUTOMOUNT;
 668
 669                         if (initrd)
 670                                 post = SPECIAL_INITRD_FS_TARGET;
 671                         else if (mount_is_network(me))
 672                                 post = SPECIAL_REMOTE_FS_TARGET;
 673                         else
 674                                 post = SPECIAL_LOCAL_FS_TARGET;
 675
 676                         k = add_mount(arg_dest,
 677                                       what,
 678                                       canonical_where ?: where,
 679                                       canonical_where ? where: NULL,
 680                                       me->mnt_type,
 681                                       me->mnt_opts,
 682                                       me->mnt_passno,
 683                                       flags,
 684                                       post,
 685                                       fstab);
 686                 }
 687
 688                 if (r >= 0 && k < 0)
 689                         r = k;
 690         }
 691
 692         return r;
 693 }
 694
 695 static int sysroot_is_nfsroot(void) {
 696         union in_addr_union u;
 697         const char *sep, *a;
 698         int r;
 699
 700         assert(arg_root_what);
 701
 702         /* From dracut.cmdline(7).
 703          *
 704          * root=[<server-ip>:]<root-dir>[:<nfs-options>]
 705          * root=nfs:[<server-ip>:]<root-dir>[:<nfs-options>],
 706          * root=nfs4:[<server-ip>:]<root-dir>[:<nfs-options>],
 707          * root={dhcp|dhcp6}
 708          *
 709          * mount nfs share from <server-ip>:/<root-dir>, if no server-ip is given, use dhcp next_server.
 710          * If server-ip is an IPv6 address it has to be put in brackets, e.g. [2001:DB8::1]. NFS options
 711          * can be appended with the prefix ":" or "," and are separated by ",". */
 712
 713         if (path_equal(arg_root_what, "/dev/nfs") ||
 714             STR_IN_SET(arg_root_what, "dhcp", "dhcp6") ||
 715             STARTSWITH_SET(arg_root_what, "nfs:", "nfs4:"))
 716                 return true;
 717
 718         /* IPv6 address */
 719         if (arg_root_what[0] == '[') {
 720                 sep = strchr(arg_root_what + 1, ']');
 721                 if (!sep)
 722                         return -EINVAL;
 723
 724                 a = strndupa(arg_root_what + 1, sep - arg_root_what - 1);
 725
 726                 r = in_addr_from_string(AF_INET6, a, &u);
 727                 if (r < 0)
 728                         return r;
 729
 730                 return true;
 731         }
 732
 733         /* IPv4 address */
 734         sep = strchr(arg_root_what, ':');
 735         if (sep) {
 736                 a = strndupa(arg_root_what, sep - arg_root_what);
 737
 738                 if (in_addr_from_string(AF_INET, a, &u) >= 0)
 739                         return true;
 740         }
 741
 742         /* root directory without address */
 743         return path_is_absolute(arg_root_what) && !path_startswith(arg_root_what, "/dev");
 744 }
 745
 746 static int add_sysroot_mount(void) {
 747         _cleanup_free_ char *what = NULL;
 748         const char *opts, *fstype;
 749         bool default_rw;
 750         int r;
 751
 752         if (isempty(arg_root_what)) {
 753                 log_debug("Could not find a root= entry on the kernel command line.");
 754                 return 0;
 755         }
 756
 757         if (streq(arg_root_what, "gpt-auto")) {
 758                 /* This is handled by the gpt-auto generator */
 759                 log_debug("Skipping root directory handling, as gpt-auto was requested.");
 760                 return 0;
 761         }
 762
 763         r = sysroot_is_nfsroot();
 764         if (r < 0)
 765                 log_debug_errno(r, "Failed to determine if the root directory is on NFS, assuming not: %m");
 766         else if (r > 0) {
 767                 /* This is handled by the kernel or the initrd */
 768                 log_debug("Skipping root directory handling, as root on NFS was requested.");
 769                 return 0;
 770         }
 771
 772         if (startswith(arg_root_what, "cifs://")) {
 773                 log_debug("Skipping root directory handling, as root on CIFS was requested.");
 774                 return 0;
 775         }
 776
 777         if (startswith(arg_root_what, "iscsi:")) {
 778                 log_debug("Skipping root directory handling, as root on iSCSI was requested.");
 779                 return 0;
 780         }
 781
 782         if (startswith(arg_root_what, "live:")) {
 783                 log_debug("Skipping root directory handling, as root on live image was requested.");
 784                 return 0;
 785         }
 786
 787         if (streq(arg_root_what, "tmpfs")) {
 788                 /* If root=tmpfs is specified, then take this as shortcut for a writable tmpfs mount as root */
 789
 790                 what = strdup("rootfs"); /* just a pretty name, to show up in /proc/self/mountinfo */
 791                 if (!what)
 792                         return log_oom();
 793
 794                 fstype = arg_root_fstype ?: "tmpfs"; /* tmpfs, unless overridden */
 795
 796                 default_rw = true; /* writable, unless overridden */;
 797         } else {
 798
 799                 what = fstab_node_to_udev_node(arg_root_what);
 800                 if (!what)
 801                         return log_oom();
 802
 803                 fstype = arg_root_fstype; /* if not specified explicitly, don't default to anything here */
 804
 805                 default_rw = false; /* read-only, unless overridden */
 806         }
 807
 808         if (!arg_root_options)
 809                 opts = arg_root_rw > 0 || (arg_root_rw < 0 && default_rw) ? "rw" : "ro";
 810         else if (arg_root_rw >= 0 ||
 811                  !fstab_test_option(arg_root_options, "ro\0" "rw\0"))
 812                 opts = strjoina(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 813         else
 814                 opts = arg_root_options;
 815
 816         log_debug("Found entry what=%s where=/sysroot type=%s opts=%s", what, strna(arg_root_fstype), strempty(opts));
 817
 818         if (is_device_path(what)) {
 819                 r = generator_write_initrd_root_device_deps(arg_dest, what);
 820                 if (r < 0)
 821                         return r;
 822         }
 823
 824         return add_mount(arg_dest,
 825                          what,
 826                          "/sysroot",
 827                          NULL,
 828                          fstype,
 829                          opts,
 830                          is_device_path(what) ? 1 : 0, /* passno */
 831                          0,                            /* makefs off, growfs off, noauto off, nofail off, automount off */
 832                          SPECIAL_INITRD_ROOT_FS_TARGET,
 833                          "/proc/cmdline");
 834 }
 835
 836 static int add_sysroot_usr_mount(void) {
 837         _cleanup_free_ char *what = NULL;
 838         const char *opts;
 839         int r;
 840
 841         /* Returns 0 if we didn't do anything, > 0 if we either generated a unit for the /usr/ mount, or we
 842          * know for sure something else did */
 843
 844         if (!arg_usr_what && !arg_usr_fstype && !arg_usr_options)
 845                 return 0;
 846
 847         if (arg_root_what && !arg_usr_what) {
 848                 /* Copy over the root device, in case the /usr mount just differs in a mount option (consider btrfs subvolumes) */
 849                 arg_usr_what = strdup(arg_root_what);
 850                 if (!arg_usr_what)
 851                         return log_oom();
 852         }
 853
 854         if (arg_root_fstype && !arg_usr_fstype) {
 855                 arg_usr_fstype = strdup(arg_root_fstype);
 856                 if (!arg_usr_fstype)
 857                         return log_oom();
 858         }
 859
 860         if (arg_root_options && !arg_usr_options) {
 861                 arg_usr_options = strdup(arg_root_options);
 862                 if (!arg_usr_options)
 863                         return log_oom();
 864         }
 865
 866         if (isempty(arg_usr_what)) {
 867                 log_debug("Could not find a usr= entry on the kernel command line.");
 868                 return 0;
 869         }
 870
 871         if (streq(arg_usr_what, "gpt-auto")) {
 872                 /* This is handled by the gpt-auto generator */
 873                 log_debug("Skipping /usr/ directory handling, as gpt-auto was requested.");
 874                 return 1; /* systemd-gpt-auto-generator will generate a unit for this, hence report that a
 875                            * unit file is being created for the host /usr/ mount. */
 876         }
 877
 878         if (path_equal(arg_usr_what, "/dev/nfs")) {
 879                 /* This is handled by the initrd (if at all supported, that is) */
 880                 log_debug("Skipping /usr/ directory handling, as /dev/nfs was requested.");
 881                 return 1; /* As above, report that NFS code will create the unit */
 882         }
 883
 884         what = fstab_node_to_udev_node(arg_usr_what);
 885         if (!what)
 886                 return log_oom();
 887
 888         if (!arg_usr_options)
 889                 opts = arg_root_rw > 0 ? "rw" : "ro";
 890         else if (!fstab_test_option(arg_usr_options, "ro\0" "rw\0"))
 891                 opts = strjoina(arg_usr_options, ",", arg_root_rw > 0 ? "rw" : "ro");
 892         else
 893                 opts = arg_usr_options;
 894
 895         /* When mounting /usr from the initrd, we add an extra level of indirection: we first mount the /usr/
 896          * partition to /sysusr/usr/, and then afterwards bind mount that to /sysroot/usr/. We do this so
 897          * that we can cover for systems that initially only have a /usr/ around and where the root fs needs
 898          * to be synthesized, based on configuration included in /usr/, e.g. systemd-repart. Software like
 899          * this should order itself after initrd-usr-fs.target and before initrd-fs.target; and it should
 900          * look into both /sysusr/ and /sysroot/ for the configuration data to apply. */
 901
 902         log_debug("Found entry what=%s where=/sysusr/usr type=%s opts=%s", what, strna(arg_usr_fstype), strempty(opts));
 903
 904         r = add_mount(arg_dest,
 905                       what,
 906                       "/sysusr/usr",
 907                       NULL,
 908                       arg_usr_fstype,
 909                       opts,
 910                       is_device_path(what) ? 1 : 0, /* passno */
 911                       0,
 912                       SPECIAL_INITRD_USR_FS_TARGET,
 913                       "/proc/cmdline");
 914         if (r < 0)
 915                 return r;
 916
 917         log_debug("Synthesizing entry what=/sysusr/usr where=/sysrootr/usr opts=bind");
 918
 919         r = add_mount(arg_dest,
 920                       "/sysusr/usr",
 921                       "/sysroot/usr",
 922                       NULL,
 923                       NULL,
 924                       "bind",
 925                       0,
 926                       0,
 927                       SPECIAL_INITRD_FS_TARGET,
 928                       "/proc/cmdline");
 929         if (r < 0)
 930                 return r;
 931
 932         return 1;
 933 }
 934
 935 static int add_sysroot_usr_mount_or_fallback(void) {
 936         int r;
 937
 938         r = add_sysroot_usr_mount();
 939         if (r != 0)
 940                 return r;
 941
 942         /* OK, so we didn't write anything out for /sysusr/usr/ nor /sysroot/usr/. In this case, let's make
 943          * sure that initrd-usr-fs.target is at least ordered after sysroot.mount so that services that order
 944          * themselves get the guarantee that /usr/ is definitely mounted somewhere. */
 945
 946         return generator_add_symlink(
 947                         arg_dest,
 948                         SPECIAL_INITRD_USR_FS_TARGET,
 949                         "requires",
 950                         "sysroot.mount");
 951 }
 952
 953 static int add_volatile_root(void) {
 954
 955         /* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
 956          * requested (or as an overlayfs), leaving only /usr from the root mount inside. */
 957
 958         if (!IN_SET(arg_volatile_mode, VOLATILE_YES, VOLATILE_OVERLAY))
 959                 return 0;
 960
 961         return generator_add_symlink(arg_dest, SPECIAL_INITRD_ROOT_FS_TARGET, "requires",
 962                                      SYSTEM_DATA_UNIT_DIR "/" SPECIAL_VOLATILE_ROOT_SERVICE);
 963 }
 964
 965 static int add_volatile_var(void) {
 966
 967         if (arg_volatile_mode != VOLATILE_STATE)
 968                 return 0;
 969
 970         /* If requested, mount /var as tmpfs, but do so only if there's nothing else defined for this. */
 971
 972         return add_mount(arg_dest_late,
 973                          "tmpfs",
 974                          "/var",
 975                          NULL,
 976                          "tmpfs",
 977                          "mode=0755" TMPFS_LIMITS_VAR,
 978                          0,
 979                          0,
 980                          SPECIAL_LOCAL_FS_TARGET,
 981                          "/proc/cmdline");
 982 }
 983
 984 static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
 985         int r;
 986
 987         /* root=, usr=, usrfstype= and roofstype= may occur more than once, the last
 988          * instance should take precedence.  In the case of multiple rootflags=
 989          * or usrflags= the arguments should be concatenated */
 990
 991         if (STR_IN_SET(key, "fstab", "rd.fstab")) {
 992
 993                 r = value ? parse_boolean(value) : 1;
 994                 if (r < 0)
 995                         log_warning("Failed to parse fstab switch %s. Ignoring.", value);
 996                 else
 997                         arg_fstab_enabled = r;
 998
 999         } else if (streq(key, "root")) {
1000
1001                 if (proc_cmdline_value_missing(key, value))
1002                         return 0;
1003
1004                 return free_and_strdup_warn(&arg_root_what, value);
1005
1006         } else if (streq(key, "rootfstype")) {
1007
1008                 if (proc_cmdline_value_missing(key, value))
1009                         return 0;
1010
1011                 return free_and_strdup_warn(&arg_root_fstype, value);
1012
1013         } else if (streq(key, "rootflags")) {
1014
1015                 if (proc_cmdline_value_missing(key, value))
1016                         return 0;
1017
1018                 if (!strextend_with_separator(&arg_root_options, ",", value))
1019                         return log_oom();
1020
1021         } else if (streq(key, "roothash")) {
1022
1023                 if (proc_cmdline_value_missing(key, value))
1024                         return 0;
1025
1026                 return free_and_strdup_warn(&arg_root_hash, value);
1027
1028         } else if (streq(key, "mount.usr")) {
1029
1030                 if (proc_cmdline_value_missing(key, value))
1031                         return 0;
1032
1033                 return free_and_strdup_warn(&arg_usr_what, value);
1034
1035         } else if (streq(key, "mount.usrfstype")) {
1036
1037                 if (proc_cmdline_value_missing(key, value))
1038                         return 0;
1039
1040                 return free_and_strdup_warn(&arg_usr_fstype, value);
1041
1042         } else if (streq(key, "mount.usrflags")) {
1043
1044                 if (proc_cmdline_value_missing(key, value))
1045                         return 0;
1046
1047                 if (!strextend_with_separator(&arg_usr_options, ",", value))
1048                         return log_oom();
1049
1050         } else if (streq(key, "usrhash")) {
1051
1052                 if (proc_cmdline_value_missing(key, value))
1053                         return 0;
1054
1055                 return free_and_strdup_warn(&arg_usr_hash, value);
1056
1057         } else if (streq(key, "rw") && !value)
1058                 arg_root_rw = true;
1059         else if (streq(key, "ro") && !value)
1060                 arg_root_rw = false;
1061         else if (streq(key, "systemd.volatile")) {
1062                 VolatileMode m;
1063
1064                 if (value) {
1065                         m = volatile_mode_from_string(value);
1066                         if (m < 0)
1067                                 log_warning_errno(m, "Failed to parse systemd.volatile= argument: %s", value);
1068                         else
1069                                 arg_volatile_mode = m;
1070                 } else
1071                         arg_volatile_mode = VOLATILE_YES;
1072
1073         } else if (streq(key, "systemd.swap")) {
1074
1075                 r = value ? parse_boolean(value) : 1;
1076                 if (r < 0)
1077                         log_warning("Failed to parse systemd.swap switch %s. Ignoring.", value);
1078                 else
1079                         arg_swap_enabled = r;
1080         }
1081
1082         return 0;
1083 }
1084
1085 static int determine_device(char **what, const char *hash, const char *name) {
1086
1087         assert(what);
1088         assert(name);
1089
1090         /* If we have a hash but no device then Verity is used, and we use the DM device. */
1091         if (*what)
1092                 return 0;
1093
1094         if (!hash)
1095                 return 0;
1096
1097         *what = path_join("/dev/mapper/", name);
1098         if (!*what)
1099                 return log_oom();
1100
1101         log_info("Using verity %s device %s.", name, *what);
1102
1103         return 1;
1104 }
1105
1106 static int determine_root(void) {
1107         return determine_device(&arg_root_what, arg_root_hash, "root");
1108 }
1109
1110 static int determine_usr(void) {
1111         return determine_device(&arg_usr_what, arg_usr_hash, "usr");
1112 }
1113
1114 static int run(const char *dest, const char *dest_early, const char *dest_late) {
1115         int r, r2 = 0, r3 = 0;
1116
1117         assert_se(arg_dest = dest);
1118         assert_se(arg_dest_late = dest_late);
1119
1120         r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
1121         if (r < 0)
1122                 log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
1123
1124         (void) determine_root();
1125         (void) determine_usr();
1126
1127         /* Always honour root= and usr= in the kernel command line if we are in an initrd */
1128         if (in_initrd()) {
1129                 r = add_sysroot_mount();
1130
1131                 r2 = add_sysroot_usr_mount_or_fallback();
1132
1133                 r3 = add_volatile_root();
1134         } else
1135                 r = add_volatile_var();
1136
1137         /* Honour /etc/fstab only when that's enabled */
1138         if (arg_fstab_enabled) {
1139                 /* Parse the local /etc/fstab, possibly from the initrd */
1140                 r2 = parse_fstab(false);
1141
1142                 /* If running in the initrd also parse the /etc/fstab from the host */
1143                 if (in_initrd())
1144                         r3 = parse_fstab(true);
1145                 else
1146                         r3 = generator_enable_remount_fs_service(arg_dest);
1147         }
1148
1149         return r < 0 ? r : r2 < 0 ? r2 : r3;
1150 }
1151
1152 DEFINE_MAIN_GENERATOR_FUNCTION(run);