src/install.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <sys/stat.h>
  23 #include <stdio.h>
  24 #include <getopt.h>
  25 #include <errno.h>
  26 #include <unistd.h>
  27
  28 #include "log.h"
  29 #include "path-lookup.h"
  30 #include "util.h"
  31 #include "macro.h"
  32 #include "strv.h"
  33 #include "conf-parser.h"
  34
  35 static bool arg_force = false;
  36
  37 static enum {
  38         WHERE_SYSTEM,
  39         WHERE_SESSION,
  40         WHERE_GLOBAL,
  41 } arg_where = WHERE_SYSTEM;
  42
  43 static enum {
  44         ACTION_INVALID,
  45         ACTION_ENABLE,
  46         ACTION_DISABLE,
  47         ACTION_TEST
  48 } arg_action = ACTION_INVALID;
  49
  50 typedef struct {
  51         char *name;
  52         char *path;
  53
  54         char **aliases;
  55         char **wanted_by;
  56 } InstallInfo;
  57
  58 Hashmap *will_install = NULL, *have_installed = NULL;
  59
  60 static int help(void) {
  61
  62         printf("%s [OPTIONS...] {COMMAND} ...\n\n"
  63                "Install init system units.\n\n"
  64                "  -h --help        Show this help\n"
  65                "     --force       Override existing links\n"
  66                "     --system      Install into system\n"
  67                "     --session     Install into session\n"
  68                "     --global      Install into all sessions\n\n"
  69                "Commands:\n"
  70                "  enable [NAME...]    Enable one or more units\n"
  71                "  disable [NAME...]   Disable one or more units\n"
  72                "  test [NAME...]      Test whether any of the specified units are enabled\n",
  73                program_invocation_short_name);
  74
  75         return 0;
  76 }
  77
  78 static int parse_argv(int argc, char *argv[]) {
  79
  80         enum {
  81                 ARG_SESSION = 0x100,
  82                 ARG_SYSTEM,
  83                 ARG_GLOBAL,
  84                 ARG_FORCE
  85         };
  86
  87         static const struct option options[] = {
  88                 { "help",      no_argument,       NULL, 'h'         },
  89                 { "session",   no_argument,       NULL, ARG_SESSION },
  90                 { "system",    no_argument,       NULL, ARG_SYSTEM  },
  91                 { "global",    no_argument,       NULL, ARG_GLOBAL  },
  92                 { "force",     no_argument,       NULL, ARG_FORCE   },
  93                 { NULL,        0,                 NULL, 0           }
  94         };
  95
  96         int c;
  97
  98         assert(argc >= 1);
  99         assert(argv);
 100
 101         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
 102
 103                 switch (c) {
 104
 105                 case 'h':
 106                         help();
 107                         return 0;
 108
 109                 case ARG_SESSION:
 110                         arg_where = WHERE_SESSION;
 111                         break;
 112
 113                 case ARG_SYSTEM:
 114                         arg_where = WHERE_SYSTEM;
 115                         break;
 116
 117                 case ARG_GLOBAL:
 118                         arg_where = WHERE_GLOBAL;
 119                         break;
 120
 121                 case ARG_FORCE:
 122                         arg_force = true;
 123                         break;
 124
 125                 case '?':
 126                         return -EINVAL;
 127
 128                 default:
 129                         log_error("Unknown option code %c", c);
 130                         return -EINVAL;
 131                 }
 132         }
 133
 134         if (optind >= argc) {
 135                 log_error("Missing verb.");
 136                 return -EINVAL;
 137         }
 138
 139         if (streq(argv[optind], "enable"))
 140                 arg_action = ACTION_ENABLE;
 141         else if (streq(argv[optind], "disable"))
 142                 arg_action = ACTION_DISABLE;
 143         else if (streq(argv[optind], "test"))
 144                 arg_action = ACTION_TEST;
 145         else {
 146                 log_error("Unknown verb %s", argv[optind]);
 147                 return -EINVAL;
 148         }
 149
 150         optind++;
 151
 152         if (optind >= argc) {
 153                 log_error("Missing unit name.");
 154                 return -EINVAL;
 155         }
 156
 157         return 1;
 158 }
 159
 160 static void install_info_free(InstallInfo *i) {
 161         assert(i);
 162
 163         free(i->name);
 164         free(i->path);
 165         strv_free(i->aliases);
 166         strv_free(i->wanted_by);
 167         free(i);
 168 }
 169
 170 static void install_info_hashmap_free(Hashmap *m) {
 171         InstallInfo *i;
 172
 173         while ((i = hashmap_steal_first(m)))
 174                 install_info_free(i);
 175
 176         hashmap_free(m);
 177 }
 178
 179 static bool unit_name_valid(const char *name) {
 180
 181         /* This is a minimal version of unit_name_valid() from
 182          * unit-name.c */
 183
 184         if (!*name)
 185                 return false;
 186
 187         if (ignore_file(name))
 188                 return false;
 189
 190         return true;
 191 }
 192
 193 static int install_info_add(const char *name) {
 194         InstallInfo *i;
 195         int r;
 196
 197         if (!unit_name_valid(name))
 198                 return -EINVAL;
 199
 200         if (hashmap_get(have_installed, name) ||
 201             hashmap_get(will_install, name))
 202                 return 0;
 203
 204         if (!(i = new0(InstallInfo, 1))) {
 205                 r = -ENOMEM;
 206                 goto fail;
 207         }
 208
 209         if (!(i->name = strdup(name))) {
 210                 r = -ENOMEM;
 211                 goto fail;
 212         }
 213
 214         if ((r = hashmap_put(will_install, i->name, i)) < 0)
 215                 goto fail;
 216
 217         return 0;
 218
 219 fail:
 220         if (i)
 221                 install_info_free(i);
 222
 223         return r;
 224 }
 225
 226 static int config_parse_also(
 227                 const char *filename,
 228                 unsigned line,
 229                 const char *section,
 230                 const char *lvalue,
 231                 const char *rvalue,
 232                 void *data,
 233                 void *userdata) {
 234
 235         char *w;
 236         size_t l;
 237         char *state;
 238
 239         assert(filename);
 240         assert(lvalue);
 241         assert(rvalue);
 242
 243         FOREACH_WORD_QUOTED(w, l, rvalue, state) {
 244                 char *n;
 245                 int r;
 246
 247                 if (!(n = strndup(w, l)))
 248                         return -ENOMEM;
 249
 250                 r = install_info_add(n);
 251                 free(n);
 252
 253                 if (r < 0)
 254                         return r;
 255         }
 256
 257         return 0;
 258 }
 259
 260 static int create_symlink(const char *old_path, const char *new_path) {
 261         int r;
 262
 263         assert(old_path);
 264         assert(new_path);
 265
 266         if (arg_action == ACTION_ENABLE) {
 267                 char *dest;
 268
 269                 mkdir_parents(new_path, 0755);
 270
 271                 if (symlink(old_path, new_path) >= 0)
 272                         return 0;
 273
 274                 if (errno != EEXIST) {
 275                         log_error("Cannot link %s to %s: %m", old_path, new_path);
 276                         return -errno;
 277                 }
 278
 279                 if ((r = readlink_and_make_absolute(new_path, &dest)) < 0) {
 280
 281                         if (errno == EINVAL) {
 282                                 log_error("Cannot link %s to %s, file exists already and is not a symlink.", old_path, new_path);
 283                                 return -EEXIST;
 284                         }
 285
 286                         log_error("readlink() failed: %s", strerror(-r));
 287                         return r;
 288                 }
 289
 290                 if (streq(dest, old_path)) {
 291                         free(dest);
 292                         return 0;
 293                 }
 294
 295                 if (!arg_force) {
 296                         log_error("Cannot link %s to %s, symlink exists already and points to %s.", old_path, new_path, dest);
 297                         free(dest);
 298                         return -EEXIST;
 299                 }
 300
 301                 free(dest);
 302                 unlink(new_path);
 303
 304                 if (symlink(old_path, new_path) >= 0)
 305                         return 0;
 306
 307                 log_error("Cannot link %s to %s: %m", old_path, new_path);
 308                 return -errno;
 309
 310         } else if (arg_action == ACTION_DISABLE) {
 311                 char *dest;
 312
 313                 if ((r = readlink_and_make_absolute(new_path, &dest)) < 0) {
 314                         if (errno == ENOENT)
 315                                 return 0;
 316
 317                         if (errno == EINVAL) {
 318                                 log_warning("File %s not a symlink, ignoring.", old_path);
 319                                 return 0;
 320                         }
 321
 322                         log_error("readlink() failed: %s", strerror(-r));
 323                         return r;
 324                 }
 325
 326                 if (!streq(dest, old_path)) {
 327                         log_warning("File %s not a symlink to %s but points to %s, ignoring.", new_path, old_path, dest);
 328                         free(dest);
 329                         return 0;
 330                 }
 331
 332                 free(dest);
 333                 if (unlink(new_path) >= 0)
 334                         return 0;
 335
 336                 log_error("Cannot unlink %s: %m", new_path);
 337                 return -errno;
 338
 339         } else if (arg_action == ACTION_TEST) {
 340                 char *dest;
 341
 342                 if ((r = readlink_and_make_absolute(new_path, &dest)) < 0) {
 343
 344                         if (errno == ENOENT || errno == EINVAL)
 345                                 return 0;
 346
 347                         log_error("readlink() failed: %s", strerror(-r));
 348                         return r;
 349                 }
 350
 351                 if (streq(dest, old_path)) {
 352                         free(dest);
 353                         return 1;
 354                 }
 355
 356                 return 0;
 357         }
 358
 359         assert_not_reached("Unknown action.");
 360 }
 361
 362 static int install_info_symlink_alias(InstallInfo *i, const char *config_path) {
 363         char **s;
 364         char *alias_path = NULL;
 365         int r;
 366
 367         assert(i);
 368
 369         STRV_FOREACH(s, i->aliases) {
 370
 371                 if (!unit_name_valid(*s)) {
 372                         log_error("Invalid name %s.", *s);
 373                         r = -EINVAL;
 374                         goto finish;
 375                 }
 376
 377                 free(alias_path);
 378                 if (!(alias_path = path_make_absolute(*s, config_path))) {
 379                         log_error("Out of memory");
 380                         r = -ENOMEM;
 381                         goto finish;
 382                 }
 383
 384                 if ((r = create_symlink(i->path, alias_path)) != 0)
 385                         goto finish;
 386
 387                 if (arg_action == ACTION_DISABLE)
 388                         rmdir_parents(alias_path, config_path);
 389         }
 390
 391         r = 0;
 392
 393 finish:
 394         free(alias_path);
 395
 396         return r;
 397 }
 398
 399 static int install_info_symlink_wants(InstallInfo *i, const char *config_path) {
 400         char **s;
 401         char *alias_path = NULL;
 402         int r;
 403
 404         assert(i);
 405
 406         STRV_FOREACH(s, i->wanted_by) {
 407                 if (!unit_name_valid(*s)) {
 408                         log_error("Invalid name %s.", *s);
 409                         r = -EINVAL;
 410                         goto finish;
 411                 }
 412
 413                 free(alias_path);
 414                 alias_path = NULL;
 415
 416                 if (asprintf(&alias_path, "%s/%s.wants/%s", config_path, *s, i->name) < 0) {
 417                         log_error("Out of memory");
 418                         r = -ENOMEM;
 419                         goto finish;
 420                 }
 421
 422                 if ((r = create_symlink(i->path, alias_path)) != 0)
 423                         goto finish;
 424
 425                 if (arg_action == ACTION_DISABLE)
 426                         rmdir_parents(alias_path, config_path);
 427         }
 428
 429         r = 0;
 430
 431 finish:
 432         free(alias_path);
 433
 434         return r;
 435 }
 436
 437 static int install_info_apply(LookupPaths *paths, InstallInfo *i, const char *config_path) {
 438
 439         const ConfigItem items[] = {
 440                 { "Alias",    config_parse_strv, &i->aliases,   "Install" },
 441                 { "WantedBy", config_parse_strv, &i->wanted_by, "Install" },
 442                 { "Also",     config_parse_also, NULL,          "Install" },
 443
 444                 { NULL, NULL, NULL, NULL }
 445         };
 446
 447         char **p;
 448         char *filename = NULL;
 449         FILE *f = NULL;
 450         int r;
 451
 452         assert(paths);
 453         assert(i);
 454
 455         STRV_FOREACH(p, paths->unit_path) {
 456
 457                 if (!(filename = path_make_absolute(i->name, *p))) {
 458                         log_error("Out of memory");
 459                         return -ENOMEM;
 460                 }
 461
 462                 if ((f = fopen(filename, "re")))
 463                         break;
 464
 465                 free(filename);
 466                 filename = NULL;
 467
 468                 if (errno != ENOENT) {
 469                         log_error("Failed to open %s: %m", filename);
 470                         return -errno;
 471                 }
 472         }
 473
 474         if (!f) {
 475                 log_error("Couldn't find %s.", i->name);
 476                 return -ENOENT;
 477         }
 478
 479         i->path = filename;
 480
 481         if ((r = config_parse(filename, f, NULL, items, true, i)) < 0) {
 482                 fclose(f);
 483                 return r;
 484         }
 485
 486         fclose(f);
 487
 488         if ((r = install_info_symlink_alias(i, config_path)) != 0)
 489                 return r;
 490
 491         if ((r = install_info_symlink_wants(i, config_path)) != 0)
 492                 return r;
 493
 494         return 0;
 495 }
 496
 497 static char *get_config_path(void) {
 498
 499         switch (arg_where) {
 500
 501         case WHERE_SYSTEM:
 502                 return strdup(SYSTEM_CONFIG_UNIT_PATH);
 503
 504         case WHERE_GLOBAL:
 505                 return strdup(SESSION_CONFIG_UNIT_PATH);
 506
 507         case WHERE_SESSION: {
 508                 char *p;
 509
 510                 if (session_config_home(&p) < 0)
 511                         return NULL;
 512
 513                 return p;
 514         }
 515
 516         default:
 517                 assert_not_reached("Unknown config path.");
 518         }
 519 }
 520
 521 int main(int argc, char *argv[]) {
 522         int r, retval = 1, j;
 523         LookupPaths paths;
 524         InstallInfo *i;
 525         char *config_path = NULL;
 526
 527         zero(paths);
 528
 529         log_parse_environment();
 530
 531         if ((r = parse_argv(argc, argv)) < 0)
 532                 goto finish;
 533         else if (r == 0) {
 534                 retval = 0;
 535                 goto finish;
 536         }
 537
 538         if ((r = lookup_paths_init(&paths, arg_where == WHERE_SYSTEM ? MANAGER_SYSTEM : MANAGER_SESSION)) < 0) {
 539                 log_error("Failed to determine lookup paths: %s", strerror(-r));
 540                 goto finish;
 541         }
 542
 543         if (!(config_path = get_config_path())) {
 544                 log_error("Failed to determine config path");
 545                 goto finish;
 546         }
 547
 548         will_install = hashmap_new(string_hash_func, string_compare_func);
 549         have_installed = hashmap_new(string_hash_func, string_compare_func);
 550
 551         if (!will_install || !have_installed) {
 552                 log_error("Failed to allocate unit sets.");
 553                 goto finish;
 554         }
 555
 556         for (j = optind; j < argc; j++)
 557                 if ((r = install_info_add(argv[j])) < 0)
 558                         goto finish;
 559
 560         while ((i = hashmap_first(will_install))) {
 561                 assert_se(hashmap_move_one(have_installed, will_install, i->name) == 0);
 562
 563                 if ((r = install_info_apply(&paths, i, config_path)) != 0) {
 564
 565                         if (r < 0)
 566                                 goto finish;
 567
 568                         /* In test mode and found something */
 569                         retval = 0;
 570                         goto finish;
 571                 }
 572         }
 573
 574         retval = arg_action == ACTION_TEST ? 1 : 0;
 575
 576 finish:
 577         install_info_hashmap_free(will_install);
 578         install_info_hashmap_free(have_installed);
 579
 580         lookup_paths_free(&paths);
 581
 582         free(config_path);
 583
 584         return retval;
 585 }