src/machine/machine.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <stdio_ext.h>
   7
   8 #include "sd-messages.h"
   9
  10 #include "alloc-util.h"
  11 #include "bus-error.h"
  12 #include "bus-util.h"
  13 #include "escape.h"
  14 #include "extract-word.h"
  15 #include "fd-util.h"
  16 #include "fileio.h"
  17 #include "format-util.h"
  18 #include "hashmap.h"
  19 #include "machine-dbus.h"
  20 #include "machine.h"
  21 #include "mkdir.h"
  22 #include "parse-util.h"
  23 #include "process-util.h"
  24 #include "serialize.h"
  25 #include "special.h"
  26 #include "stdio-util.h"
  27 #include "string-table.h"
  28 #include "terminal-util.h"
  29 #include "unit-name.h"
  30 #include "user-util.h"
  31 #include "util.h"
  32
  33 Machine* machine_new(Manager *manager, MachineClass class, const char *name) {
  34         Machine *m;
  35
  36         assert(manager);
  37         assert(class < _MACHINE_CLASS_MAX);
  38         assert(name);
  39
  40         /* Passing class == _MACHINE_CLASS_INVALID here is fine. It
  41          * means as much as "we don't know yet", and that we'll figure
  42          * it out later when loading the state file. */
  43
  44         m = new0(Machine, 1);
  45         if (!m)
  46                 return NULL;
  47
  48         m->name = strdup(name);
  49         if (!m->name)
  50                 goto fail;
  51
  52         if (class != MACHINE_HOST) {
  53                 m->state_file = strappend("/run/systemd/machines/", m->name);
  54                 if (!m->state_file)
  55                         goto fail;
  56         }
  57
  58         m->class = class;
  59
  60         if (hashmap_put(manager->machines, m->name, m) < 0)
  61                 goto fail;
  62
  63         m->manager = manager;
  64
  65         return m;
  66
  67 fail:
  68         free(m->state_file);
  69         free(m->name);
  70         return mfree(m);
  71 }
  72
  73 void machine_free(Machine *m) {
  74         assert(m);
  75
  76         while (m->operations)
  77                 operation_free(m->operations);
  78
  79         if (m->in_gc_queue)
  80                 LIST_REMOVE(gc_queue, m->manager->machine_gc_queue, m);
  81
  82         machine_release_unit(m);
  83
  84         free(m->scope_job);
  85
  86         (void) hashmap_remove(m->manager->machines, m->name);
  87
  88         if (m->manager->host_machine == m)
  89                 m->manager->host_machine = NULL;
  90
  91         if (m->leader > 0)
  92                 (void) hashmap_remove_value(m->manager->machine_leaders, PID_TO_PTR(m->leader), m);
  93
  94         sd_bus_message_unref(m->create_message);
  95
  96         free(m->name);
  97         free(m->state_file);
  98         free(m->service);
  99         free(m->root_directory);
 100         free(m->netif);
 101         free(m);
 102 }
 103
 104 int machine_save(Machine *m) {
 105         _cleanup_free_ char *temp_path = NULL;
 106         _cleanup_fclose_ FILE *f = NULL;
 107         int r;
 108
 109         assert(m);
 110
 111         if (!m->state_file)
 112                 return 0;
 113
 114         if (!m->started)
 115                 return 0;
 116
 117         r = mkdir_safe_label("/run/systemd/machines", 0755, 0, 0, MKDIR_WARN_MODE);
 118         if (r < 0)
 119                 goto fail;
 120
 121         r = fopen_temporary(m->state_file, &f, &temp_path);
 122         if (r < 0)
 123                 goto fail;
 124
 125         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 126         (void) fchmod(fileno(f), 0644);
 127
 128         fprintf(f,
 129                 "# This is private data. Do not parse.\n"
 130                 "NAME=%s\n",
 131                 m->name);
 132
 133         if (m->unit) {
 134                 _cleanup_free_ char *escaped;
 135
 136                 escaped = cescape(m->unit);
 137                 if (!escaped) {
 138                         r = -ENOMEM;
 139                         goto fail;
 140                 }
 141
 142                 fprintf(f, "SCOPE=%s\n", escaped); /* We continue to call this "SCOPE=" because it is internal only, and we want to stay compatible with old files */
 143         }
 144
 145         if (m->scope_job)
 146                 fprintf(f, "SCOPE_JOB=%s\n", m->scope_job);
 147
 148         if (m->service) {
 149                 _cleanup_free_ char *escaped;
 150
 151                 escaped = cescape(m->service);
 152                 if (!escaped) {
 153                         r = -ENOMEM;
 154                         goto fail;
 155                 }
 156                 fprintf(f, "SERVICE=%s\n", escaped);
 157         }
 158
 159         if (m->root_directory) {
 160                 _cleanup_free_ char *escaped;
 161
 162                 escaped = cescape(m->root_directory);
 163                 if (!escaped) {
 164                         r = -ENOMEM;
 165                         goto fail;
 166                 }
 167                 fprintf(f, "ROOT=%s\n", escaped);
 168         }
 169
 170         if (!sd_id128_is_null(m->id))
 171                 fprintf(f, "ID=" SD_ID128_FORMAT_STR "\n", SD_ID128_FORMAT_VAL(m->id));
 172
 173         if (m->leader != 0)
 174                 fprintf(f, "LEADER="PID_FMT"\n", m->leader);
 175
 176         if (m->class != _MACHINE_CLASS_INVALID)
 177                 fprintf(f, "CLASS=%s\n", machine_class_to_string(m->class));
 178
 179         if (dual_timestamp_is_set(&m->timestamp))
 180                 fprintf(f,
 181                         "REALTIME="USEC_FMT"\n"
 182                         "MONOTONIC="USEC_FMT"\n",
 183                         m->timestamp.realtime,
 184                         m->timestamp.monotonic);
 185
 186         if (m->n_netif > 0) {
 187                 size_t i;
 188
 189                 fputs("NETIF=", f);
 190
 191                 for (i = 0; i < m->n_netif; i++) {
 192                         if (i != 0)
 193                                 fputc(' ', f);
 194
 195                         fprintf(f, "%i", m->netif[i]);
 196                 }
 197
 198                 fputc('\n', f);
 199         }
 200
 201         r = fflush_and_check(f);
 202         if (r < 0)
 203                 goto fail;
 204
 205         if (rename(temp_path, m->state_file) < 0) {
 206                 r = -errno;
 207                 goto fail;
 208         }
 209
 210         if (m->unit) {
 211                 char *sl;
 212
 213                 /* Create a symlink from the unit name to the machine
 214                  * name, so that we can quickly find the machine for
 215                  * each given unit. Ignore error. */
 216                 sl = strjoina("/run/systemd/machines/unit:", m->unit);
 217                 (void) symlink(m->name, sl);
 218         }
 219
 220         return 0;
 221
 222 fail:
 223         (void) unlink(m->state_file);
 224
 225         if (temp_path)
 226                 (void) unlink(temp_path);
 227
 228         return log_error_errno(r, "Failed to save machine data %s: %m", m->state_file);
 229 }
 230
 231 static void machine_unlink(Machine *m) {
 232         assert(m);
 233
 234         if (m->unit) {
 235                 char *sl;
 236
 237                 sl = strjoina("/run/systemd/machines/unit:", m->unit);
 238                 (void) unlink(sl);
 239         }
 240
 241         if (m->state_file)
 242                 (void) unlink(m->state_file);
 243 }
 244
 245 int machine_load(Machine *m) {
 246         _cleanup_free_ char *realtime = NULL, *monotonic = NULL, *id = NULL, *leader = NULL, *class = NULL, *netif = NULL;
 247         int r;
 248
 249         assert(m);
 250
 251         if (!m->state_file)
 252                 return 0;
 253
 254         r = parse_env_file(NULL, m->state_file,
 255                            "SCOPE",     &m->unit,
 256                            "SCOPE_JOB", &m->scope_job,
 257                            "SERVICE",   &m->service,
 258                            "ROOT",      &m->root_directory,
 259                            "ID",        &id,
 260                            "LEADER",    &leader,
 261                            "CLASS",     &class,
 262                            "REALTIME",  &realtime,
 263                            "MONOTONIC", &monotonic,
 264                            "NETIF",     &netif);
 265         if (r < 0) {
 266                 if (r == -ENOENT)
 267                         return 0;
 268
 269                 return log_error_errno(r, "Failed to read %s: %m", m->state_file);
 270         }
 271
 272         if (id)
 273                 sd_id128_from_string(id, &m->id);
 274
 275         if (leader)
 276                 parse_pid(leader, &m->leader);
 277
 278         if (class) {
 279                 MachineClass c;
 280
 281                 c = machine_class_from_string(class);
 282                 if (c >= 0)
 283                         m->class = c;
 284         }
 285
 286         if (realtime)
 287                 (void) deserialize_usec(realtime, &m->timestamp.realtime);
 288         if (monotonic)
 289                 (void) deserialize_usec(monotonic, &m->timestamp.monotonic);
 290
 291         if (netif) {
 292                 size_t allocated = 0, nr = 0;
 293                 const char *p;
 294                 int *ni = NULL;
 295
 296                 p = netif;
 297                 for (;;) {
 298                         _cleanup_free_ char *word = NULL;
 299                         int ifi;
 300
 301                         r = extract_first_word(&p, &word, NULL, 0);
 302                         if (r == 0)
 303                                 break;
 304                         if (r == -ENOMEM)
 305                                 return log_oom();
 306                         if (r < 0) {
 307                                 log_warning_errno(r, "Failed to parse NETIF: %s", netif);
 308                                 break;
 309                         }
 310
 311                         if (parse_ifindex(word, &ifi) < 0)
 312                                 continue;
 313
 314                         if (!GREEDY_REALLOC(ni, allocated, nr+1)) {
 315                                 free(ni);
 316                                 return log_oom();
 317                         }
 318
 319                         ni[nr++] = ifi;
 320                 }
 321
 322                 free(m->netif);
 323                 m->netif = ni;
 324                 m->n_netif = nr;
 325         }
 326
 327         return r;
 328 }
 329
 330 static int machine_start_scope(Machine *m, sd_bus_message *properties, sd_bus_error *error) {
 331         assert(m);
 332         assert(m->class != MACHINE_HOST);
 333
 334         if (!m->unit) {
 335                 _cleanup_free_ char *escaped = NULL, *scope = NULL;
 336                 char *description, *job = NULL;
 337                 int r;
 338
 339                 escaped = unit_name_escape(m->name);
 340                 if (!escaped)
 341                         return log_oom();
 342
 343                 scope = strjoin("machine-", escaped, ".scope");
 344                 if (!scope)
 345                         return log_oom();
 346
 347                 description = strjoina(m->class == MACHINE_VM ? "Virtual Machine " : "Container ", m->name);
 348
 349                 r = manager_start_scope(m->manager, scope, m->leader, SPECIAL_MACHINE_SLICE, description, properties, error, &job);
 350                 if (r < 0)
 351                         return log_error_errno(r, "Failed to start machine scope: %s", bus_error_message(error, r));
 352
 353                 m->unit = TAKE_PTR(scope);
 354                 free_and_replace(m->scope_job, job);
 355         }
 356
 357         if (m->unit)
 358                 hashmap_put(m->manager->machine_units, m->unit, m);
 359
 360         return 0;
 361 }
 362
 363 int machine_start(Machine *m, sd_bus_message *properties, sd_bus_error *error) {
 364         int r;
 365
 366         assert(m);
 367
 368         if (!IN_SET(m->class, MACHINE_CONTAINER, MACHINE_VM))
 369                 return -EOPNOTSUPP;
 370
 371         if (m->started)
 372                 return 0;
 373
 374         r = hashmap_put(m->manager->machine_leaders, PID_TO_PTR(m->leader), m);
 375         if (r < 0)
 376                 return r;
 377
 378         /* Create cgroup */
 379         r = machine_start_scope(m, properties, error);
 380         if (r < 0)
 381                 return r;
 382
 383         log_struct(LOG_INFO,
 384                    "MESSAGE_ID=" SD_MESSAGE_MACHINE_START_STR,
 385                    "NAME=%s", m->name,
 386                    "LEADER="PID_FMT, m->leader,
 387                    LOG_MESSAGE("New machine %s.", m->name));
 388
 389         if (!dual_timestamp_is_set(&m->timestamp))
 390                 dual_timestamp_get(&m->timestamp);
 391
 392         m->started = true;
 393
 394         /* Save new machine data */
 395         machine_save(m);
 396
 397         machine_send_signal(m, true);
 398
 399         return 0;
 400 }
 401
 402 static int machine_stop_scope(Machine *m) {
 403         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 404         char *job = NULL;
 405         int r, q;
 406
 407         assert(m);
 408         assert(m->class != MACHINE_HOST);
 409
 410         if (!m->unit)
 411                 return 0;
 412
 413         r = manager_stop_unit(m->manager, m->unit, &error, &job);
 414         if (r < 0) {
 415                 log_error_errno(r, "Failed to stop machine scope: %s", bus_error_message(&error, r));
 416                 sd_bus_error_free(&error);
 417         } else
 418                 free_and_replace(m->scope_job, job);
 419
 420         q = manager_unref_unit(m->manager, m->unit, &error);
 421         if (q < 0)
 422                 log_warning_errno(q, "Failed to drop reference to machine scope, ignoring: %s", bus_error_message(&error, r));
 423
 424         return r;
 425 }
 426
 427 int machine_stop(Machine *m) {
 428         int r;
 429         assert(m);
 430
 431         if (!IN_SET(m->class, MACHINE_CONTAINER, MACHINE_VM))
 432                 return -EOPNOTSUPP;
 433
 434         r = machine_stop_scope(m);
 435
 436         m->stopping = true;
 437
 438         machine_save(m);
 439
 440         return r;
 441 }
 442
 443 int machine_finalize(Machine *m) {
 444         assert(m);
 445
 446         if (m->started)
 447                 log_struct(LOG_INFO,
 448                            "MESSAGE_ID=" SD_MESSAGE_MACHINE_STOP_STR,
 449                            "NAME=%s", m->name,
 450                            "LEADER="PID_FMT, m->leader,
 451                            LOG_MESSAGE("Machine %s terminated.", m->name));
 452
 453         machine_unlink(m);
 454         machine_add_to_gc_queue(m);
 455
 456         if (m->started) {
 457                 machine_send_signal(m, false);
 458                 m->started = false;
 459         }
 460
 461         return 0;
 462 }
 463
 464 bool machine_may_gc(Machine *m, bool drop_not_started) {
 465         assert(m);
 466
 467         if (m->class == MACHINE_HOST)
 468                 return false;
 469
 470         if (drop_not_started && !m->started)
 471                 return true;
 472
 473         if (m->scope_job && manager_job_is_active(m->manager, m->scope_job))
 474                 return false;
 475
 476         if (m->unit && manager_unit_is_active(m->manager, m->unit))
 477                 return false;
 478
 479         return true;
 480 }
 481
 482 void machine_add_to_gc_queue(Machine *m) {
 483         assert(m);
 484
 485         if (m->in_gc_queue)
 486                 return;
 487
 488         LIST_PREPEND(gc_queue, m->manager->machine_gc_queue, m);
 489         m->in_gc_queue = true;
 490 }
 491
 492 MachineState machine_get_state(Machine *s) {
 493         assert(s);
 494
 495         if (s->class == MACHINE_HOST)
 496                 return MACHINE_RUNNING;
 497
 498         if (s->stopping)
 499                 return MACHINE_CLOSING;
 500
 501         if (s->scope_job)
 502                 return MACHINE_OPENING;
 503
 504         return MACHINE_RUNNING;
 505 }
 506
 507 int machine_kill(Machine *m, KillWho who, int signo) {
 508         assert(m);
 509
 510         if (!IN_SET(m->class, MACHINE_VM, MACHINE_CONTAINER))
 511                 return -EOPNOTSUPP;
 512
 513         if (!m->unit)
 514                 return -ESRCH;
 515
 516         if (who == KILL_LEADER) {
 517                 /* If we shall simply kill the leader, do so directly */
 518
 519                 if (kill(m->leader, signo) < 0)
 520                         return -errno;
 521
 522                 return 0;
 523         }
 524
 525         /* Otherwise, make PID 1 do it for us, for the entire cgroup */
 526         return manager_kill_unit(m->manager, m->unit, signo, NULL);
 527 }
 528
 529 int machine_openpt(Machine *m, int flags) {
 530         assert(m);
 531
 532         switch (m->class) {
 533
 534         case MACHINE_HOST: {
 535                 int fd;
 536
 537                 fd = posix_openpt(flags);
 538                 if (fd < 0)
 539                         return -errno;
 540
 541                 if (unlockpt(fd) < 0)
 542                         return -errno;
 543
 544                 return fd;
 545         }
 546
 547         case MACHINE_CONTAINER:
 548                 if (m->leader <= 0)
 549                         return -EINVAL;
 550
 551                 return openpt_in_namespace(m->leader, flags);
 552
 553         default:
 554                 return -EOPNOTSUPP;
 555         }
 556 }
 557
 558 int machine_open_terminal(Machine *m, const char *path, int mode) {
 559         assert(m);
 560
 561         switch (m->class) {
 562
 563         case MACHINE_HOST:
 564                 return open_terminal(path, mode);
 565
 566         case MACHINE_CONTAINER:
 567                 if (m->leader <= 0)
 568                         return -EINVAL;
 569
 570                 return open_terminal_in_namespace(m->leader, path, mode);
 571
 572         default:
 573                 return -EOPNOTSUPP;
 574         }
 575 }
 576
 577 void machine_release_unit(Machine *m) {
 578         assert(m);
 579
 580         if (!m->unit)
 581                 return;
 582
 583         (void) hashmap_remove(m->manager->machine_units, m->unit);
 584         m->unit = mfree(m->unit);
 585 }
 586
 587 int machine_get_uid_shift(Machine *m, uid_t *ret) {
 588         char p[STRLEN("/proc//uid_map") + DECIMAL_STR_MAX(pid_t) + 1];
 589         uid_t uid_base, uid_shift, uid_range;
 590         gid_t gid_base, gid_shift, gid_range;
 591         _cleanup_fclose_ FILE *f = NULL;
 592         int k;
 593
 594         assert(m);
 595         assert(ret);
 596
 597         /* Return the base UID/GID of the specified machine. Note that this only works for containers with simple
 598          * mappings. In most cases setups should be simple like this, and administrators should only care about the
 599          * basic offset a container has relative to the host. This is what this function exposes.
 600          *
 601          * If we encounter any more complex mappings we politely refuse this with ENXIO. */
 602
 603         if (m->class == MACHINE_HOST) {
 604                 *ret = 0;
 605                 return 0;
 606         }
 607
 608         if (m->class != MACHINE_CONTAINER)
 609                 return -EOPNOTSUPP;
 610
 611         xsprintf(p, "/proc/" PID_FMT "/uid_map", m->leader);
 612         f = fopen(p, "re");
 613         if (!f) {
 614                 if (errno == ENOENT) {
 615                         /* If the file doesn't exist, user namespacing is off in the kernel, return a zero mapping hence. */
 616                         *ret = 0;
 617                         return 0;
 618                 }
 619
 620                 return -errno;
 621         }
 622
 623         /* Read the first line. There's at least one. */
 624         errno = 0;
 625         k = fscanf(f, UID_FMT " " UID_FMT " " UID_FMT "\n", &uid_base, &uid_shift, &uid_range);
 626         if (k != 3) {
 627                 if (ferror(f))
 628                         return -errno;
 629
 630                 return -EBADMSG;
 631         }
 632
 633         /* Not a mapping starting at 0? Then it's a complex mapping we can't expose here. */
 634         if (uid_base != 0)
 635                 return -ENXIO;
 636         /* Insist that at least the nobody user is mapped, everything else is weird, and hence complex, and we don't support it */
 637         if (uid_range < UID_NOBODY)
 638                 return -ENXIO;
 639
 640         /* If there's more than one line, then we don't support this mapping. */
 641         if (fgetc(f) != EOF)
 642                 return -ENXIO;
 643
 644         fclose(f);
 645
 646         xsprintf(p, "/proc/" PID_FMT "/gid_map", m->leader);
 647         f = fopen(p, "re");
 648         if (!f)
 649                 return -errno;
 650
 651         /* Read the first line. There's at least one. */
 652         errno = 0;
 653         k = fscanf(f, GID_FMT " " GID_FMT " " GID_FMT "\n", &gid_base, &gid_shift, &gid_range);
 654         if (k != 3) {
 655                 if (ferror(f))
 656                         return -errno;
 657
 658                 return -EBADMSG;
 659         }
 660
 661         /* If there's more than one line, then we don't support this file. */
 662         if (fgetc(f) != EOF)
 663                 return -ENXIO;
 664
 665         /* If the UID and GID mapping doesn't match, we don't support this mapping. */
 666         if (uid_base != (uid_t) gid_base)
 667                 return -ENXIO;
 668         if (uid_shift != (uid_t) gid_shift)
 669                 return -ENXIO;
 670         if (uid_range != (uid_t) gid_range)
 671                 return -ENXIO;
 672
 673         *ret = uid_shift;
 674         return 0;
 675 }
 676
 677 static const char* const machine_class_table[_MACHINE_CLASS_MAX] = {
 678         [MACHINE_CONTAINER] = "container",
 679         [MACHINE_VM] = "vm",
 680         [MACHINE_HOST] = "host",
 681 };
 682
 683 DEFINE_STRING_TABLE_LOOKUP(machine_class, MachineClass);
 684
 685 static const char* const machine_state_table[_MACHINE_STATE_MAX] = {
 686         [MACHINE_OPENING] = "opening",
 687         [MACHINE_RUNNING] = "running",
 688         [MACHINE_CLOSING] = "closing"
 689 };
 690
 691 DEFINE_STRING_TABLE_LOOKUP(machine_state, MachineState);
 692
 693 static const char* const kill_who_table[_KILL_WHO_MAX] = {
 694         [KILL_LEADER] = "leader",
 695         [KILL_ALL] = "all"
 696 };
 697
 698 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);