src/fstab-generator/fstab-generator.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2012 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 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   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <stdio.h>
  23 #include <mntent.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27
  28 #include "log.h"
  29 #include "util.h"
  30 #include "unit-name.h"
  31 #include "path-util.h"
  32 #include "mount-setup.h"
  33 #include "special.h"
  34 #include "mkdir.h"
  35 #include "virt.h"
  36
  37 static const char *arg_dest = "/tmp";
  38 static bool arg_enabled = true;
  39
  40 static int device_name(const char *path, char **unit) {
  41         char *p;
  42
  43         assert(path);
  44
  45         if (!is_device_path(path))
  46                 return 0;
  47
  48         p = unit_name_from_path(path, ".device");
  49         if (!p)
  50                 return -ENOMEM;
  51
  52         *unit = p;
  53         return 1;
  54 }
  55
  56 static int mount_find_pri(struct mntent *me, int *ret) {
  57         char *end, *pri;
  58         unsigned long r;
  59
  60         assert(me);
  61         assert(ret);
  62
  63         pri = hasmntopt(me, "pri");
  64         if (!pri)
  65                 return 0;
  66
  67         pri += 4;
  68
  69         errno = 0;
  70         r = strtoul(pri, &end, 10);
  71         if (errno != 0)
  72                 return -errno;
  73
  74         if (end == pri || (*end != ',' && *end != 0))
  75                 return -EINVAL;
  76
  77         *ret = (int) r;
  78         return 1;
  79 }
  80
  81 static int add_swap(const char *what, struct mntent *me) {
  82         char *name = NULL, *unit = NULL, *lnk = NULL, *device = NULL;
  83         FILE *f = NULL;
  84         bool noauto, nofail;
  85         int r, pri = -1;
  86
  87         assert(what);
  88         assert(me);
  89
  90         r = mount_find_pri(me, &pri);
  91         if (r < 0) {
  92                 log_error("Failed to parse priority");
  93                 return pri;
  94         }
  95
  96         noauto = !!hasmntopt(me, "noauto");
  97         nofail = !!hasmntopt(me, "nofail");
  98
  99         name = unit_name_from_path(what, ".swap");
 100         if (!name) {
 101                 log_error("Out of memory.");
 102                 r = -ENOMEM;
 103                 goto finish;
 104         }
 105
 106         unit = strjoin(arg_dest, "/", name, NULL);
 107         if (!unit) {
 108                 log_error("Out of memory.");
 109                 r = -ENOMEM;
 110                 goto finish;
 111         }
 112
 113         f = fopen(unit, "wxe");
 114         if (!f) {
 115                 r = -errno;
 116                 log_error("Failed to create unit file: %m");
 117                 goto finish;
 118         }
 119
 120         fputs("# Automatically generated by systemd-fstab-generator\n\n"
 121               "[Unit]\n"
 122               "SourcePath=/etc/fstab\n"
 123               "DefaultDependencies=no\n"
 124               "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
 125               "Before=" SPECIAL_UMOUNT_TARGET "\n", f);
 126
 127         if (!noauto && !nofail)
 128                 fputs("Before=" SPECIAL_SWAP_TARGET "\n", f);
 129
 130         fprintf(f,
 131                 "\n"
 132                 "[Swap]\n"
 133                 "What=%s\n",
 134                 what);
 135
 136         if (pri >= 0)
 137                 fprintf(f,
 138                         "Priority=%i\n",
 139                         pri);
 140
 141         fflush(f);
 142         if (ferror(f)) {
 143                 log_error("Failed to write unit file: %m");
 144                 r = -errno;
 145                 goto finish;
 146         }
 147
 148         if (!noauto) {
 149                 lnk = strjoin(arg_dest, "/" SPECIAL_SWAP_TARGET ".wants/", name, NULL);
 150                 if (!lnk) {
 151                         log_error("Out of memory.");
 152                         r = -ENOMEM;
 153                         goto finish;
 154                 }
 155
 156                 mkdir_parents_label(lnk, 0755);
 157                 if (symlink(unit, lnk) < 0) {
 158                         log_error("Failed to create symlink: %m");
 159                         r = -errno;
 160                         goto finish;
 161                 }
 162
 163                 r = device_name(what, &device);
 164                 if (r < 0) {
 165                         log_error("Out of memory.");
 166                         r = -ENOMEM;
 167                         goto finish;
 168                 }
 169
 170                 if (r > 0) {
 171                         free(lnk);
 172                         lnk = strjoin(arg_dest, "/", device, ".wants/", name, NULL);
 173                         if (!lnk) {
 174                                 log_error("Out of memory.");
 175                                 r = -ENOMEM;
 176                                 goto finish;
 177                         }
 178
 179                         mkdir_parents_label(lnk, 0755);
 180                         if (symlink(unit, lnk) < 0) {
 181                                 log_error("Failed to create symlink: %m");
 182                                 r = -errno;
 183                                 goto finish;
 184                         }
 185                 }
 186         }
 187
 188         r = 0;
 189 finish:
 190         if (f)
 191                 fclose(f);
 192
 193         free(unit);
 194         free(lnk);
 195         free(name);
 196         free(device);
 197
 198         return r;
 199 }
 200
 201 static bool mount_is_bind(struct mntent *me) {
 202         assert(me);
 203
 204         return
 205                 hasmntopt(me, "bind") ||
 206                 streq(me->mnt_opts, "bind");
 207 }
 208
 209 static bool mount_is_network(struct mntent *me) {
 210         assert(me);
 211
 212         return
 213                 hasmntopt(me, "_netdev") ||
 214                 fstype_is_network(me->mnt_type);
 215 }
 216
 217 static int add_mount(const char *what, const char *where, struct mntent *me) {
 218         char *name = NULL, *unit = NULL, *lnk = NULL, *device = NULL, *automount_name = NULL, *automount_unit = NULL;
 219         FILE *f = NULL;
 220         bool noauto, nofail, automount, isbind, isnetwork;
 221         int r;
 222         const char *post, *pre;
 223
 224         assert(what);
 225         assert(where);
 226         assert(me);
 227
 228         if (streq(me->mnt_type, "autofs"))
 229                 return 0;
 230
 231         if (!is_path(where)) {
 232                 log_warning("Mount point %s is not a valid path, ignoring.", where);
 233                 return 0;
 234         }
 235
 236         if (mount_point_is_api(where) ||
 237             mount_point_ignore(where))
 238                 return 0;
 239
 240         isnetwork = mount_is_network(me);
 241         isbind = mount_is_bind(me);
 242
 243         noauto = !!hasmntopt(me, "noauto");
 244         nofail = !!hasmntopt(me, "nofail");
 245         automount =
 246                 hasmntopt(me, "comment=systemd.automount") ||
 247                 hasmntopt(me, "x-systemd.automount");
 248
 249         if (isnetwork) {
 250                 post = SPECIAL_REMOTE_FS_TARGET;
 251                 pre = SPECIAL_REMOTE_FS_PRE_TARGET;
 252         } else {
 253                 post = SPECIAL_LOCAL_FS_TARGET;
 254                 pre = SPECIAL_LOCAL_FS_PRE_TARGET;
 255         }
 256
 257         name = unit_name_from_path(where, ".mount");
 258         if (!name)  {
 259                 log_error("Out of memory.");
 260                 r = -ENOMEM;
 261                 goto finish;
 262         }
 263
 264         unit = strjoin(arg_dest, "/", name, NULL);
 265         if (!unit) {
 266                 log_error("Out of memory.");
 267                 r = -ENOMEM;
 268                 goto finish;
 269         }
 270
 271         f = fopen(unit, "wxe");
 272         if (!f) {
 273                 r = -errno;
 274                 log_error("Failed to create unit file: %m");
 275                 goto finish;
 276         }
 277
 278         fputs("# Automatically generated by systemd-fstab-generator\n\n"
 279               "[Unit]\n"
 280               "SourcePath=/etc/fstab\n"
 281               "DefaultDependencies=no\n", f);
 282
 283         if (!path_equal(where, "/"))
 284                 fprintf(f,
 285                         "After=%s\n"
 286                         "Wants=%s\n"
 287                         "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
 288                         "Before=" SPECIAL_UMOUNT_TARGET "\n",
 289                         pre,
 290                         pre);
 291
 292
 293         if (!noauto && !nofail && !automount)
 294                 fprintf(f,
 295                         "Before=%s\n",
 296                         post);
 297
 298         fprintf(f,
 299                 "\n"
 300                 "[Mount]\n"
 301                 "What=%s\n"
 302                 "Where=%s\n"
 303                 "Type=%s\n"
 304                 "FsckPassNo=%i\n",
 305                 what,
 306                 where,
 307                 me->mnt_type,
 308                 me->mnt_passno);
 309
 310         if (!isempty(me->mnt_opts) &&
 311             !streq(me->mnt_opts, "defaults"))
 312                 fprintf(f,
 313                         "Options=%s\n",
 314                         me->mnt_opts);
 315
 316         fflush(f);
 317         if (ferror(f)) {
 318                 log_error("Failed to write unit file: %m");
 319                 r = -errno;
 320                 goto finish;
 321         }
 322
 323         if (!noauto) {
 324                 lnk = strjoin(arg_dest, "/", post, nofail || automount ? ".wants/" : ".requires/", name, NULL);
 325                 if (!lnk) {
 326                         log_error("Out of memory.");
 327                         r = -ENOMEM;
 328                         goto finish;
 329                 }
 330
 331                 mkdir_parents_label(lnk, 0755);
 332                 if (symlink(unit, lnk) < 0) {
 333                         log_error("Failed to create symlink: %m");
 334                         r = -errno;
 335                         goto finish;
 336                 }
 337
 338                 if (!isbind &&
 339                     !path_equal(where, "/")) {
 340
 341                         r = device_name(what, &device);
 342                         if (r < 0) {
 343                                 log_error("Out of memory.");
 344                                 r = -ENOMEM;
 345                                 goto finish;
 346                         }
 347
 348                         if (r > 0) {
 349                                 free(lnk);
 350                                 lnk = strjoin(arg_dest, "/", device, ".wants/", name, NULL);
 351                                 if (!lnk) {
 352                                         log_error("Out of memory.");
 353                                         r = -ENOMEM;
 354                                         goto finish;
 355                                 }
 356
 357                                 mkdir_parents_label(lnk, 0755);
 358                                 if (symlink(unit, lnk) < 0) {
 359                                         log_error("Failed to creat symlink: %m");
 360                                         r = -errno;
 361                                         goto finish;
 362                                 }
 363                         }
 364                 }
 365         }
 366
 367         if (automount && !path_equal(where, "/")) {
 368                 automount_name = unit_name_from_path(where, ".automount");
 369                 if (!name) {
 370                         log_error("Out of memory.");
 371                         r = -ENOMEM;
 372                         goto finish;
 373                 }
 374
 375                 automount_unit = strjoin(arg_dest, "/", automount_name, NULL);
 376                 if (!automount_unit) {
 377                         log_error("Out of memory.");
 378                         r = -ENOMEM;
 379                         goto finish;
 380                 }
 381
 382                 fclose(f);
 383                 f = fopen(automount_unit, "wxe");
 384                 if (!f) {
 385                         r = -errno;
 386                         log_error("Failed to create unit file: %m");
 387                         goto finish;
 388                 }
 389
 390                 fprintf(f,
 391                         "# Automatically generated by systemd-fstab-generator\n\n"
 392                         "[Unit]\n"
 393                         "SourcePath=/etc/fstab\n"
 394                         "DefaultDependencies=no\n"
 395                         "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
 396                         "Before=" SPECIAL_UMOUNT_TARGET " %s\n"
 397                         "\n"
 398                         "[Automount]\n"
 399                         "Where=%s\n",
 400                         post,
 401                         where);
 402
 403                 fflush(f);
 404                 if (ferror(f)) {
 405                         log_error("Failed to write unit file: %m");
 406                         r = -errno;
 407                         goto finish;
 408                 }
 409
 410                 free(lnk);
 411                 lnk = strjoin(arg_dest, "/", post, nofail ? ".wants/" : ".requires/", automount_name, NULL);
 412                 if (!lnk) {
 413                         log_error("Out of memory.");
 414                         r = -ENOMEM;
 415                         goto finish;
 416                 }
 417
 418                 mkdir_parents_label(lnk, 0755);
 419                 if (symlink(automount_unit, lnk) < 0) {
 420                         log_error("Failed to create symlink: %m");
 421                         r = -errno;
 422                         goto finish;
 423                 }
 424         }
 425
 426         r = 0;
 427 finish:
 428         if (f)
 429                 fclose(f);
 430
 431         free(unit);
 432         free(lnk);
 433         free(name);
 434         free(device);
 435         free(automount_name);
 436         free(automount_unit);
 437
 438         return r;
 439 }
 440
 441 static int parse_fstab(void) {
 442         FILE *f;
 443         int r = 0;
 444         struct mntent *me;
 445
 446         errno = 0;
 447         f = setmntent("/etc/fstab", "r");
 448         if (!f) {
 449                 if (errno == ENOENT)
 450                         return 0;
 451
 452                 log_error("Failed to open /etc/fstab: %m");
 453                 return -errno;
 454         }
 455
 456         while ((me = getmntent(f))) {
 457                 char *where, *what;
 458                 int k;
 459
 460                 what = fstab_node_to_udev_node(me->mnt_fsname);
 461                 if (!what) {
 462                         log_error("Out of memory.");
 463                         r = -ENOMEM;
 464                         goto finish;
 465                 }
 466
 467                 where = strdup(me->mnt_dir);
 468                 if (!where) {
 469                         log_error("Out of memory.");
 470                         free(what);
 471                         r = -ENOMEM;
 472                         goto finish;
 473                 }
 474
 475                 if (is_path(where))
 476                         path_kill_slashes(where);
 477
 478                 log_debug("Found entry what=%s where=%s type=%s", what, where, me->mnt_type);
 479
 480                 if (streq(me->mnt_type, "swap"))
 481                         k = add_swap(what, me);
 482                 else
 483                         k = add_mount(what, where, me);
 484
 485                 free(what);
 486                 free(where);
 487
 488                 if (k < 0)
 489                         r = k;
 490         }
 491
 492 finish:
 493         endmntent(f);
 494         return r;
 495 }
 496
 497 static int parse_proc_cmdline(void) {
 498         char *line, *w, *state;
 499         int r;
 500         size_t l;
 501
 502         if (detect_container(NULL) > 0)
 503                 return 0;
 504
 505         r = read_one_line_file("/proc/cmdline", &line);
 506         if (r < 0) {
 507                 log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
 508                 return 0;
 509         }
 510
 511         FOREACH_WORD_QUOTED(w, l, line, state) {
 512                 char *word;
 513
 514                 word = strndup(w, l);
 515                 if (!word) {
 516                         r = -ENOMEM;
 517                         goto finish;
 518                 }
 519
 520                 if (startswith(word, "fstab=")) {
 521                         r = parse_boolean(word + 6);
 522                         if (r < 0)
 523                                 log_warning("Failed to parse fstab switch %s. Ignoring.", word + 6);
 524                         else
 525                                 arg_enabled = r;
 526
 527                 } else if (startswith(word, "rd.fstab=")) {
 528
 529                         if (in_initrd()) {
 530                                 r = parse_boolean(word + 6);
 531                                 if (r < 0)
 532                                         log_warning("Failed to parse fstab switch %s. Ignoring.", word + 6);
 533                                 else
 534                                         arg_enabled = r;
 535                         }
 536
 537                 } else if (startswith(word, "fstab.") ||
 538                            (in_initrd() && startswith(word, "rd.fstab."))) {
 539
 540                         log_warning("Unknown kernel switch %s. Ignoring.", word);
 541                 }
 542
 543                 free(word);
 544         }
 545
 546         r = 0;
 547
 548 finish:
 549         free(line);
 550         return r;
 551 }
 552
 553 int main(int argc, char *argv[]) {
 554         int r;
 555
 556         if (argc > 1 && argc != 4) {
 557                 log_error("This program takes three or no arguments.");
 558                 return EXIT_FAILURE;
 559         }
 560
 561         if (argc > 1)
 562                 arg_dest = argv[1];
 563
 564         log_set_target(LOG_TARGET_SAFE);
 565         log_parse_environment();
 566         log_open();
 567
 568         umask(0022);
 569
 570         if (parse_proc_cmdline() < 0)
 571                 return EXIT_FAILURE;
 572
 573         if (!arg_enabled)
 574                 return EXIT_SUCCESS;
 575
 576         r = parse_fstab();
 577
 578         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 579 }