src/machine/image-dbus.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2014 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <sys/file.h>
  21 #include <sys/mount.h>
  22
  23 #include "alloc-util.h"
  24 #include "bus-label.h"
  25 #include "bus-util.h"
  26 #include "copy.h"
  27 #include "dissect-image.h"
  28 #include "fd-util.h"
  29 #include "fileio.h"
  30 #include "fs-util.h"
  31 #include "image-dbus.h"
  32 #include "io-util.h"
  33 #include "loop-util.h"
  34 #include "machine-image.h"
  35 #include "mount-util.h"
  36 #include "process-util.h"
  37 #include "raw-clone.h"
  38 #include "strv.h"
  39 #include "user-util.h"
  40
  41 static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_type, image_type, ImageType);
  42
  43 int bus_image_method_remove(
  44                 sd_bus_message *message,
  45                 void *userdata,
  46                 sd_bus_error *error) {
  47
  48         _cleanup_close_pair_ int errno_pipe_fd[2] = { -1, -1 };
  49         Image *image = userdata;
  50         Manager *m = image->userdata;
  51         pid_t child;
  52         int r;
  53
  54         assert(message);
  55         assert(image);
  56
  57         if (m->n_operations >= OPERATIONS_MAX)
  58                 return sd_bus_error_setf(error, SD_BUS_ERROR_LIMITS_EXCEEDED, "Too many ongoing operations.");
  59
  60         r = bus_verify_polkit_async(
  61                         message,
  62                         CAP_SYS_ADMIN,
  63                         "org.freedesktop.machine1.manage-images",
  64                         NULL,
  65                         false,
  66                         UID_INVALID,
  67                         &m->polkit_registry,
  68                         error);
  69         if (r < 0)
  70                 return r;
  71         if (r == 0)
  72                 return 1; /* Will call us back */
  73
  74         if (pipe2(errno_pipe_fd, O_CLOEXEC|O_NONBLOCK) < 0)
  75                 return sd_bus_error_set_errnof(error, errno, "Failed to create pipe: %m");
  76
  77         child = fork();
  78         if (child < 0)
  79                 return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
  80         if (child == 0) {
  81                 errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]);
  82
  83                 r = image_remove(image);
  84                 if (r < 0) {
  85                         (void) write(errno_pipe_fd[1], &r, sizeof(r));
  86                         _exit(EXIT_FAILURE);
  87                 }
  88
  89                 _exit(EXIT_SUCCESS);
  90         }
  91
  92         errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]);
  93
  94         r = operation_new(m, NULL, child, message, errno_pipe_fd[0], NULL);
  95         if (r < 0) {
  96                 (void) sigkill_wait(child);
  97                 return r;
  98         }
  99
 100         errno_pipe_fd[0] = -1;
 101
 102         return 1;
 103 }
 104
 105 int bus_image_method_rename(
 106                 sd_bus_message *message,
 107                 void *userdata,
 108                 sd_bus_error *error) {
 109
 110         Image *image = userdata;
 111         Manager *m = image->userdata;
 112         const char *new_name;
 113         int r;
 114
 115         assert(message);
 116         assert(image);
 117
 118         r = sd_bus_message_read(message, "s", &new_name);
 119         if (r < 0)
 120                 return r;
 121
 122         if (!image_name_is_valid(new_name))
 123                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Image name '%s' is invalid.", new_name);
 124
 125         r = bus_verify_polkit_async(
 126                         message,
 127                         CAP_SYS_ADMIN,
 128                         "org.freedesktop.machine1.manage-images",
 129                         NULL,
 130                         false,
 131                         UID_INVALID,
 132                         &m->polkit_registry,
 133                         error);
 134         if (r < 0)
 135                 return r;
 136         if (r == 0)
 137                 return 1; /* Will call us back */
 138
 139         r = image_rename(image, new_name);
 140         if (r < 0)
 141                 return r;
 142
 143         return sd_bus_reply_method_return(message, NULL);
 144 }
 145
 146 int bus_image_method_clone(
 147                 sd_bus_message *message,
 148                 void *userdata,
 149                 sd_bus_error *error) {
 150
 151         _cleanup_close_pair_ int errno_pipe_fd[2] = { -1, -1 };
 152         Image *image = userdata;
 153         Manager *m = image->userdata;
 154         const char *new_name;
 155         int r, read_only;
 156         pid_t child;
 157
 158         assert(message);
 159         assert(image);
 160         assert(m);
 161
 162         if (m->n_operations >= OPERATIONS_MAX)
 163                 return sd_bus_error_setf(error, SD_BUS_ERROR_LIMITS_EXCEEDED, "Too many ongoing operations.");
 164
 165         r = sd_bus_message_read(message, "sb", &new_name, &read_only);
 166         if (r < 0)
 167                 return r;
 168
 169         if (!image_name_is_valid(new_name))
 170                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Image name '%s' is invalid.", new_name);
 171
 172         r = bus_verify_polkit_async(
 173                         message,
 174                         CAP_SYS_ADMIN,
 175                         "org.freedesktop.machine1.manage-images",
 176                         NULL,
 177                         false,
 178                         UID_INVALID,
 179                         &m->polkit_registry,
 180                         error);
 181         if (r < 0)
 182                 return r;
 183         if (r == 0)
 184                 return 1; /* Will call us back */
 185
 186         if (pipe2(errno_pipe_fd, O_CLOEXEC|O_NONBLOCK) < 0)
 187                 return sd_bus_error_set_errnof(error, errno, "Failed to create pipe: %m");
 188
 189         child = fork();
 190         if (child < 0)
 191                 return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
 192         if (child == 0) {
 193                 errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]);
 194
 195                 r = image_clone(image, new_name, read_only);
 196                 if (r < 0) {
 197                         (void) write(errno_pipe_fd[1], &r, sizeof(r));
 198                         _exit(EXIT_FAILURE);
 199                 }
 200
 201                 _exit(EXIT_SUCCESS);
 202         }
 203
 204         errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]);
 205
 206         r = operation_new(m, NULL, child, message, errno_pipe_fd[0], NULL);
 207         if (r < 0) {
 208                 (void) sigkill_wait(child);
 209                 return r;
 210         }
 211
 212         errno_pipe_fd[0] = -1;
 213
 214         return 1;
 215 }
 216
 217 int bus_image_method_mark_read_only(
 218                 sd_bus_message *message,
 219                 void *userdata,
 220                 sd_bus_error *error) {
 221
 222         Image *image = userdata;
 223         Manager *m = image->userdata;
 224         int r, read_only;
 225
 226         assert(message);
 227
 228         r = sd_bus_message_read(message, "b", &read_only);
 229         if (r < 0)
 230                 return r;
 231
 232         r = bus_verify_polkit_async(
 233                         message,
 234                         CAP_SYS_ADMIN,
 235                         "org.freedesktop.machine1.manage-images",
 236                         NULL,
 237                         false,
 238                         UID_INVALID,
 239                         &m->polkit_registry,
 240                         error);
 241         if (r < 0)
 242                 return r;
 243         if (r == 0)
 244                 return 1; /* Will call us back */
 245
 246         r = image_read_only(image, read_only);
 247         if (r < 0)
 248                 return r;
 249
 250         return sd_bus_reply_method_return(message, NULL);
 251 }
 252
 253 int bus_image_method_set_limit(
 254                 sd_bus_message *message,
 255                 void *userdata,
 256                 sd_bus_error *error) {
 257
 258         Image *image = userdata;
 259         Manager *m = image->userdata;
 260         uint64_t limit;
 261         int r;
 262
 263         assert(message);
 264
 265         r = sd_bus_message_read(message, "t", &limit);
 266         if (r < 0)
 267                 return r;
 268         if (!FILE_SIZE_VALID_OR_INFINITY(limit))
 269                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "New limit out of range");
 270
 271         r = bus_verify_polkit_async(
 272                         message,
 273                         CAP_SYS_ADMIN,
 274                         "org.freedesktop.machine1.manage-images",
 275                         NULL,
 276                         false,
 277                         UID_INVALID,
 278                         &m->polkit_registry,
 279                         error);
 280         if (r < 0)
 281                 return r;
 282         if (r == 0)
 283                 return 1; /* Will call us back */
 284
 285         r = image_set_limit(image, limit);
 286         if (r < 0)
 287                 return r;
 288
 289         return sd_bus_reply_method_return(message, NULL);
 290 }
 291
 292 #define EXIT_NOT_FOUND 2
 293
 294 static int directory_image_get_os_release(Image *image, char ***ret, sd_bus_error *error) {
 295
 296         _cleanup_free_ char *path = NULL;
 297         int r;
 298
 299         assert(image);
 300         assert(ret);
 301
 302         r = chase_symlinks("/etc/os-release", image->path, CHASE_PREFIX_ROOT, &path);
 303         if (r == -ENOENT)
 304                 r = chase_symlinks("/usr/lib/os-release", image->path, CHASE_PREFIX_ROOT, &path);
 305         if (r == -ENOENT)
 306                 return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Image does not contain OS release information");
 307         if (r < 0)
 308                 return sd_bus_error_set_errnof(error, r, "Failed to resolve %s: %m", image->path);
 309
 310         r = load_env_file_pairs(NULL, path, NULL, ret);
 311         if (r < 0)
 312                 return sd_bus_error_set_errnof(error, r, "Failed to open %s: %m", path);
 313
 314         return 0;
 315 }
 316
 317 static int raw_image_get_os_release(Image *image, char ***ret, sd_bus_error *error) {
 318         _cleanup_(rmdir_and_freep) char *t = NULL;
 319         _cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
 320         _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
 321         _cleanup_(sigkill_waitp) pid_t child = 0;
 322         _cleanup_close_pair_ int pair[2] = { -1, -1 };
 323         _cleanup_fclose_ FILE *f = NULL;
 324         _cleanup_strv_free_ char **v = NULL;
 325         siginfo_t si;
 326         int r;
 327
 328         assert(image);
 329         assert(ret);
 330
 331         r = mkdtemp_malloc("/tmp/machined-root-XXXXXX", &t);
 332         if (r < 0)
 333                 return sd_bus_error_set_errnof(error, r, "Failed to create temporary directory: %m");
 334
 335         r = loop_device_make_by_path(image->path, O_RDONLY, &d);
 336         if (r < 0)
 337                 return sd_bus_error_set_errnof(error, r, "Failed to set up loop block device for %s: %m", image->path);
 338
 339         r = dissect_image(d->fd, NULL, 0, DISSECT_IMAGE_REQUIRE_ROOT, &m);
 340         if (r == -ENOPKG)
 341                 return sd_bus_error_set_errnof(error, r, "Disk image %s not understood: %m", image->path);
 342         if (r < 0)
 343                 return sd_bus_error_set_errnof(error, r, "Failed to dissect image %s: %m", image->path);
 344
 345         if (pipe2(pair, O_CLOEXEC) < 0)
 346                 return sd_bus_error_set_errnof(error, errno, "Failed to create communication pipe: %m");
 347
 348         child = raw_clone(SIGCHLD|CLONE_NEWNS);
 349         if (child < 0)
 350                 return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
 351
 352         if (child == 0) {
 353                 int fd;
 354
 355                 pair[0] = safe_close(pair[0]);
 356
 357                 /* Make sure we never propagate to the host */
 358                 if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) < 0)
 359                         _exit(EXIT_FAILURE);
 360
 361                 r = dissected_image_mount(m, t, DISSECT_IMAGE_READ_ONLY);
 362                 if (r < 0)
 363                         _exit(EXIT_FAILURE);
 364
 365                 r = mount_move_root(t);
 366                 if (r < 0)
 367                         _exit(EXIT_FAILURE);
 368
 369                 fd = open("/etc/os-release", O_RDONLY|O_CLOEXEC|O_NOCTTY);
 370                 if (fd < 0 && errno == ENOENT) {
 371                         fd = open("/usr/lib/os-release", O_RDONLY|O_CLOEXEC|O_NOCTTY);
 372                         if (fd < 0 && errno == ENOENT)
 373                                 _exit(EXIT_NOT_FOUND);
 374                 }
 375                 if (fd < 0)
 376                         _exit(EXIT_FAILURE);
 377
 378                 r = copy_bytes(fd, pair[1], (uint64_t) -1, 0);
 379                 if (r < 0)
 380                         _exit(EXIT_FAILURE);
 381
 382                 _exit(EXIT_SUCCESS);
 383         }
 384
 385         pair[1] = safe_close(pair[1]);
 386
 387         f = fdopen(pair[0], "re");
 388         if (!f)
 389                 return -errno;
 390
 391         pair[0] = -1;
 392
 393         r = load_env_file_pairs(f, "os-release", NULL, &v);
 394         if (r < 0)
 395                 return r;
 396
 397         r = wait_for_terminate(child, &si);
 398         if (r < 0)
 399                 return sd_bus_error_set_errnof(error, r, "Failed to wait for child: %m");
 400         child = 0;
 401         if (si.si_code == CLD_EXITED && si.si_status == EXIT_NOT_FOUND)
 402                 return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Image does not contain OS release information");
 403         if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
 404                 return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Child died abnormally.");
 405
 406         *ret = v;
 407         v = NULL;
 408
 409         return 0;
 410 }
 411
 412 int bus_image_method_get_os_release(
 413                 sd_bus_message *message,
 414                 void *userdata,
 415                 sd_bus_error *error) {
 416
 417         _cleanup_release_lock_file_ LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT;
 418         _cleanup_strv_free_ char **v = NULL;
 419         Image *image = userdata;
 420         int r;
 421
 422         r = image_path_lock(image->path, LOCK_SH|LOCK_NB, &tree_global_lock, &tree_local_lock);
 423         if (r < 0)
 424                 return sd_bus_error_set_errnof(error, r, "Failed to lock image: %m");
 425
 426         switch (image->type) {
 427
 428         case IMAGE_DIRECTORY:
 429         case IMAGE_SUBVOLUME:
 430                 r = directory_image_get_os_release(image, &v, error);
 431                 break;
 432
 433         case IMAGE_RAW:
 434         case IMAGE_BLOCK:
 435                 r = raw_image_get_os_release(image, &v, error);
 436                 break;
 437
 438         default:
 439                 assert_not_reached("Unknown image type");
 440         }
 441         if (r < 0)
 442                 return r;
 443
 444         return bus_reply_pair_array(message, v);
 445 }
 446
 447 const sd_bus_vtable image_vtable[] = {
 448         SD_BUS_VTABLE_START(0),
 449         SD_BUS_PROPERTY("Name", "s", NULL, offsetof(Image, name), 0),
 450         SD_BUS_PROPERTY("Path", "s", NULL, offsetof(Image, path), 0),
 451         SD_BUS_PROPERTY("Type", "s", property_get_type,  offsetof(Image, type), 0),
 452         SD_BUS_PROPERTY("ReadOnly", "b", bus_property_get_bool, offsetof(Image, read_only), 0),
 453         SD_BUS_PROPERTY("CreationTimestamp", "t", NULL, offsetof(Image, crtime), 0),
 454         SD_BUS_PROPERTY("ModificationTimestamp", "t", NULL, offsetof(Image, mtime), 0),
 455         SD_BUS_PROPERTY("Usage", "t", NULL, offsetof(Image, usage), 0),
 456         SD_BUS_PROPERTY("Limit", "t", NULL, offsetof(Image, limit), 0),
 457         SD_BUS_PROPERTY("UsageExclusive", "t", NULL, offsetof(Image, usage_exclusive), 0),
 458         SD_BUS_PROPERTY("LimitExclusive", "t", NULL, offsetof(Image, limit_exclusive), 0),
 459         SD_BUS_METHOD("Remove", NULL, NULL, bus_image_method_remove, SD_BUS_VTABLE_UNPRIVILEGED),
 460         SD_BUS_METHOD("Rename", "s", NULL, bus_image_method_rename, SD_BUS_VTABLE_UNPRIVILEGED),
 461         SD_BUS_METHOD("Clone", "sb", NULL, bus_image_method_clone, SD_BUS_VTABLE_UNPRIVILEGED),
 462         SD_BUS_METHOD("MarkReadOnly", "b", NULL, bus_image_method_mark_read_only, SD_BUS_VTABLE_UNPRIVILEGED),
 463         SD_BUS_METHOD("SetLimit", "t", NULL, bus_image_method_set_limit, SD_BUS_VTABLE_UNPRIVILEGED),
 464         SD_BUS_METHOD("GetOSRelease", NULL, "a{ss}", bus_image_method_get_os_release, SD_BUS_VTABLE_UNPRIVILEGED),
 465         SD_BUS_VTABLE_END
 466 };
 467
 468 static int image_flush_cache(sd_event_source *s, void *userdata) {
 469         Manager *m = userdata;
 470         Image *i;
 471
 472         assert(s);
 473         assert(m);
 474
 475         while ((i = hashmap_steal_first(m->image_cache)))
 476                 image_unref(i);
 477
 478         return 0;
 479 }
 480
 481 int image_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
 482         _cleanup_free_ char *e = NULL;
 483         Manager *m = userdata;
 484         Image *image = NULL;
 485         const char *p;
 486         int r;
 487
 488         assert(bus);
 489         assert(path);
 490         assert(interface);
 491         assert(found);
 492
 493         p = startswith(path, "/org/freedesktop/machine1/image/");
 494         if (!p)
 495                 return 0;
 496
 497         e = bus_label_unescape(p);
 498         if (!e)
 499                 return -ENOMEM;
 500
 501         image = hashmap_get(m->image_cache, e);
 502         if (image) {
 503                 *found = image;
 504                 return 1;
 505         }
 506
 507         r = hashmap_ensure_allocated(&m->image_cache, &string_hash_ops);
 508         if (r < 0)
 509                 return r;
 510
 511         if (!m->image_cache_defer_event) {
 512                 r = sd_event_add_defer(m->event, &m->image_cache_defer_event, image_flush_cache, m);
 513                 if (r < 0)
 514                         return r;
 515
 516                 r = sd_event_source_set_priority(m->image_cache_defer_event, SD_EVENT_PRIORITY_IDLE);
 517                 if (r < 0)
 518                         return r;
 519         }
 520
 521         r = sd_event_source_set_enabled(m->image_cache_defer_event, SD_EVENT_ONESHOT);
 522         if (r < 0)
 523                 return r;
 524
 525         r = image_find(e, &image);
 526         if (r <= 0)
 527                 return r;
 528
 529         image->userdata = m;
 530
 531         r = hashmap_put(m->image_cache, image->name, image);
 532         if (r < 0) {
 533                 image_unref(image);
 534                 return r;
 535         }
 536
 537         *found = image;
 538         return 1;
 539 }
 540
 541 char *image_bus_path(const char *name) {
 542         _cleanup_free_ char *e = NULL;
 543
 544         assert(name);
 545
 546         e = bus_label_escape(name);
 547         if (!e)
 548                 return NULL;
 549
 550         return strappend("/org/freedesktop/machine1/image/", e);
 551 }
 552
 553 int image_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
 554         _cleanup_(image_hashmap_freep) Hashmap *images = NULL;
 555         _cleanup_strv_free_ char **l = NULL;
 556         Image *image;
 557         Iterator i;
 558         int r;
 559
 560         assert(bus);
 561         assert(path);
 562         assert(nodes);
 563
 564         images = hashmap_new(&string_hash_ops);
 565         if (!images)
 566                 return -ENOMEM;
 567
 568         r = image_discover(images);
 569         if (r < 0)
 570                 return r;
 571
 572         HASHMAP_FOREACH(image, images, i) {
 573                 char *p;
 574
 575                 p = image_bus_path(image->name);
 576                 if (!p)
 577                         return -ENOMEM;
 578
 579                 r = strv_consume(&l, p);
 580                 if (r < 0)
 581                         return r;
 582         }
 583
 584         *nodes = l;
 585         l = NULL;
 586
 587         return 1;
 588 }