src/shared/cgroup-util.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   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 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 <errno.h>
  23 #include <unistd.h>
  24 #include <signal.h>
  25 #include <string.h>
  26 #include <stdlib.h>
  27 #include <dirent.h>
  28 #include <sys/stat.h>
  29 #include <sys/types.h>
  30 #include <ftw.h>
  31
  32 #include "cgroup-util.h"
  33 #include "log.h"
  34 #include "set.h"
  35 #include "macro.h"
  36 #include "util.h"
  37 #include "path-util.h"
  38 #include "strv.h"
  39 #include "unit-name.h"
  40 #include "fileio.h"
  41 #include "special.h"
  42 #include "mkdir.h"
  43
  44 int cg_enumerate_processes(const char *controller, const char *path, FILE **_f) {
  45         _cleanup_free_ char *fs = NULL;
  46         FILE *f;
  47         int r;
  48
  49         assert(_f);
  50
  51         r = cg_get_path(controller, path, "cgroup.procs", &fs);
  52         if (r < 0)
  53                 return r;
  54
  55         f = fopen(fs, "re");
  56         if (!f)
  57                 return -errno;
  58
  59         *_f = f;
  60         return 0;
  61 }
  62
  63 int cg_read_pid(FILE *f, pid_t *_pid) {
  64         unsigned long ul;
  65
  66         /* Note that the cgroup.procs might contain duplicates! See
  67          * cgroups.txt for details. */
  68
  69         assert(f);
  70         assert(_pid);
  71
  72         errno = 0;
  73         if (fscanf(f, "%lu", &ul) != 1) {
  74
  75                 if (feof(f))
  76                         return 0;
  77
  78                 return errno ? -errno : -EIO;
  79         }
  80
  81         if (ul <= 0)
  82                 return -EIO;
  83
  84         *_pid = (pid_t) ul;
  85         return 1;
  86 }
  87
  88 int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d) {
  89         _cleanup_free_ char *fs = NULL;
  90         int r;
  91         DIR *d;
  92
  93         assert(_d);
  94
  95         /* This is not recursive! */
  96
  97         r = cg_get_path(controller, path, NULL, &fs);
  98         if (r < 0)
  99                 return r;
 100
 101         d = opendir(fs);
 102         if (!d)
 103                 return -errno;
 104
 105         *_d = d;
 106         return 0;
 107 }
 108
 109 int cg_read_subgroup(DIR *d, char **fn) {
 110         struct dirent *de;
 111
 112         assert(d);
 113         assert(fn);
 114
 115         FOREACH_DIRENT(de, d, return -errno) {
 116                 char *b;
 117
 118                 if (de->d_type != DT_DIR)
 119                         continue;
 120
 121                 if (streq(de->d_name, ".") ||
 122                     streq(de->d_name, ".."))
 123                         continue;
 124
 125                 b = strdup(de->d_name);
 126                 if (!b)
 127                         return -ENOMEM;
 128
 129                 *fn = b;
 130                 return 1;
 131         }
 132
 133         return 0;
 134 }
 135
 136 int cg_rmdir(const char *controller, const char *path) {
 137         _cleanup_free_ char *p = NULL;
 138         int r;
 139
 140         r = cg_get_path(controller, path, NULL, &p);
 141         if (r < 0)
 142                 return r;
 143
 144         r = rmdir(p);
 145         if (r < 0 && errno != ENOENT)
 146                 return -errno;
 147
 148         return 0;
 149 }
 150
 151 int cg_kill(const char *controller, const char *path, int sig, bool sigcont, bool ignore_self, Set *s) {
 152         _cleanup_set_free_ Set *allocated_set = NULL;
 153         bool done = false;
 154         int r, ret = 0;
 155         pid_t my_pid;
 156
 157         assert(sig >= 0);
 158
 159         /* This goes through the tasks list and kills them all. This
 160          * is repeated until no further processes are added to the
 161          * tasks list, to properly handle forking processes */
 162
 163         if (!s) {
 164                 s = allocated_set = set_new(trivial_hash_func, trivial_compare_func);
 165                 if (!s)
 166                         return -ENOMEM;
 167         }
 168
 169         my_pid = getpid();
 170
 171         do {
 172                 _cleanup_fclose_ FILE *f = NULL;
 173                 pid_t pid = 0;
 174                 done = true;
 175
 176                 r = cg_enumerate_processes(controller, path, &f);
 177                 if (r < 0) {
 178                         if (ret >= 0 && r != -ENOENT)
 179                                 return r;
 180
 181                         return ret;
 182                 }
 183
 184                 while ((r = cg_read_pid(f, &pid)) > 0) {
 185
 186                         if (ignore_self && pid == my_pid)
 187                                 continue;
 188
 189                         if (set_get(s, LONG_TO_PTR(pid)) == LONG_TO_PTR(pid))
 190                                 continue;
 191
 192                         /* If we haven't killed this process yet, kill
 193                          * it */
 194                         if (kill(pid, sig) < 0) {
 195                                 if (ret >= 0 && errno != ESRCH)
 196                                         ret = -errno;
 197                         } else {
 198                                 if (sigcont)
 199                                         kill(pid, SIGCONT);
 200
 201                                 if (ret == 0)
 202                                         ret = 1;
 203                         }
 204
 205                         done = false;
 206
 207                         r = set_put(s, LONG_TO_PTR(pid));
 208                         if (r < 0) {
 209                                 if (ret >= 0)
 210                                         return r;
 211
 212                                 return ret;
 213                         }
 214                 }
 215
 216                 if (r < 0) {
 217                         if (ret >= 0)
 218                                 return r;
 219
 220                         return ret;
 221                 }
 222
 223                 /* To avoid racing against processes which fork
 224                  * quicker than we can kill them we repeat this until
 225                  * no new pids need to be killed. */
 226
 227         } while (!done);
 228
 229         return ret;
 230 }
 231
 232 int cg_kill_recursive(const char *controller, const char *path, int sig, bool sigcont, bool ignore_self, bool rem, Set *s) {
 233         _cleanup_set_free_ Set *allocated_set = NULL;
 234         _cleanup_closedir_ DIR *d = NULL;
 235         int r, ret = 0;
 236         char *fn;
 237
 238         assert(path);
 239         assert(sig >= 0);
 240
 241         if (!s) {
 242                 s = allocated_set = set_new(trivial_hash_func, trivial_compare_func);
 243                 if (!s)
 244                         return -ENOMEM;
 245         }
 246
 247         ret = cg_kill(controller, path, sig, sigcont, ignore_self, s);
 248
 249         r = cg_enumerate_subgroups(controller, path, &d);
 250         if (r < 0) {
 251                 if (ret >= 0 && r != -ENOENT)
 252                         return r;
 253
 254                 return ret;
 255         }
 256
 257         while ((r = cg_read_subgroup(d, &fn)) > 0) {
 258                 _cleanup_free_ char *p = NULL;
 259
 260                 p = strjoin(path, "/", fn, NULL);
 261                 free(fn);
 262                 if (!p)
 263                         return -ENOMEM;
 264
 265                 r = cg_kill_recursive(controller, p, sig, sigcont, ignore_self, rem, s);
 266                 if (ret >= 0 && r != 0)
 267                         ret = r;
 268         }
 269
 270         if (ret >= 0 && r < 0)
 271                 ret = r;
 272
 273         if (rem) {
 274                 r = cg_rmdir(controller, path);
 275                 if (r < 0 && ret >= 0 && r != -ENOENT && r != -EBUSY)
 276                         return r;
 277         }
 278
 279         return ret;
 280 }
 281
 282 int cg_migrate(const char *cfrom, const char *pfrom, const char *cto, const char *pto, bool ignore_self) {
 283         bool done = false;
 284         _cleanup_set_free_ Set *s = NULL;
 285         int r, ret = 0;
 286         pid_t my_pid;
 287
 288         assert(cfrom);
 289         assert(pfrom);
 290         assert(cto);
 291         assert(pto);
 292
 293         s = set_new(trivial_hash_func, trivial_compare_func);
 294         if (!s)
 295                 return -ENOMEM;
 296
 297         my_pid = getpid();
 298
 299         do {
 300                 _cleanup_fclose_ FILE *f = NULL;
 301                 pid_t pid = 0;
 302                 done = true;
 303
 304                 r = cg_enumerate_processes(cfrom, pfrom, &f);
 305                 if (r < 0) {
 306                         if (ret >= 0 && r != -ENOENT)
 307                                 return r;
 308
 309                         return ret;
 310                 }
 311
 312                 while ((r = cg_read_pid(f, &pid)) > 0) {
 313
 314                         /* This might do weird stuff if we aren't a
 315                          * single-threaded program. However, we
 316                          * luckily know we are not */
 317                         if (ignore_self && pid == my_pid)
 318                                 continue;
 319
 320                         if (set_get(s, LONG_TO_PTR(pid)) == LONG_TO_PTR(pid))
 321                                 continue;
 322
 323                         r = cg_attach(cto, pto, pid);
 324                         if (r < 0) {
 325                                 if (ret >= 0 && r != -ESRCH)
 326                                         ret = r;
 327                         } else if (ret == 0)
 328                                 ret = 1;
 329
 330                         done = false;
 331
 332                         r = set_put(s, LONG_TO_PTR(pid));
 333                         if (r < 0) {
 334                                 if (ret >= 0)
 335                                         return r;
 336
 337                                 return ret;
 338                         }
 339                 }
 340
 341                 if (r < 0) {
 342                         if (ret >= 0)
 343                                 return r;
 344
 345                         return ret;
 346                 }
 347         } while (!done);
 348
 349         return ret;
 350 }
 351
 352 int cg_migrate_recursive(
 353                 const char *cfrom,
 354                 const char *pfrom,
 355                 const char *cto,
 356                 const char *pto,
 357                 bool ignore_self,
 358                 bool rem) {
 359
 360         _cleanup_closedir_ DIR *d = NULL;
 361         int r, ret = 0;
 362         char *fn;
 363
 364         assert(cfrom);
 365         assert(pfrom);
 366         assert(cto);
 367         assert(pto);
 368
 369         ret = cg_migrate(cfrom, pfrom, cto, pto, ignore_self);
 370
 371         r = cg_enumerate_subgroups(cfrom, pfrom, &d);
 372         if (r < 0) {
 373                 if (ret >= 0 && r != -ENOENT)
 374                         return r;
 375
 376                 return ret;
 377         }
 378
 379         while ((r = cg_read_subgroup(d, &fn)) > 0) {
 380                 _cleanup_free_ char *p = NULL;
 381
 382                 p = strjoin(pfrom, "/", fn, NULL);
 383                 free(fn);
 384                 if (!p) {
 385                         if (ret >= 0)
 386                                 return -ENOMEM;
 387
 388                         return ret;
 389                 }
 390
 391                 r = cg_migrate_recursive(cfrom, p, cto, pto, ignore_self, rem);
 392                 if (r != 0 && ret >= 0)
 393                         ret = r;
 394         }
 395
 396         if (r < 0 && ret >= 0)
 397                 ret = r;
 398
 399         if (rem) {
 400                 r = cg_rmdir(cfrom, pfrom);
 401                 if (r < 0 && ret >= 0 && r != -ENOENT && r != -EBUSY)
 402                         return r;
 403         }
 404
 405         return ret;
 406 }
 407
 408 int cg_migrate_recursive_fallback(
 409                 const char *cfrom,
 410                 const char *pfrom,
 411                 const char *cto,
 412                 const char *pto,
 413                 bool ignore_self,
 414                 bool rem) {
 415
 416         int r;
 417
 418         assert(cfrom);
 419         assert(pfrom);
 420         assert(cto);
 421         assert(pto);
 422
 423         r = cg_migrate_recursive(cfrom, pfrom, cto, pto, ignore_self, rem);
 424         if (r < 0) {
 425                 char prefix[strlen(pto) + 1];
 426
 427                 /* This didn't work? Then let's try all prefixes of the destination */
 428
 429                 PATH_FOREACH_PREFIX(prefix, pto) {
 430                         r = cg_migrate_recursive(cfrom, pfrom, cto, prefix, ignore_self, rem);
 431                         if (r >= 0)
 432                                 break;
 433                 }
 434         }
 435
 436         return 0;
 437 }
 438
 439 static const char *normalize_controller(const char *controller) {
 440
 441         assert(controller);
 442
 443         if (streq(controller, SYSTEMD_CGROUP_CONTROLLER))
 444                 return "systemd";
 445         else if (startswith(controller, "name="))
 446                 return controller + 5;
 447         else
 448                 return controller;
 449 }
 450
 451 static int join_path(const char *controller, const char *path, const char *suffix, char **fs) {
 452         char *t = NULL;
 453
 454         if (!isempty(controller)) {
 455                 if (!isempty(path) && !isempty(suffix))
 456                         t = strjoin("/sys/fs/cgroup/", controller, "/", path, "/", suffix, NULL);
 457                 else if (!isempty(path))
 458                         t = strjoin("/sys/fs/cgroup/", controller, "/", path, NULL);
 459                 else if (!isempty(suffix))
 460                         t = strjoin("/sys/fs/cgroup/", controller, "/", suffix, NULL);
 461                 else
 462                         t = strappend("/sys/fs/cgroup/", controller);
 463         } else {
 464                 if (!isempty(path) && !isempty(suffix))
 465                         t = strjoin(path, "/", suffix, NULL);
 466                 else if (!isempty(path))
 467                         t = strdup(path);
 468                 else
 469                         return -EINVAL;
 470         }
 471
 472         if (!t)
 473                 return -ENOMEM;
 474
 475         path_kill_slashes(t);
 476
 477         *fs = t;
 478         return 0;
 479 }
 480
 481 int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) {
 482         const char *p;
 483         static thread_local bool good = false;
 484
 485         assert(fs);
 486
 487         if (controller && !cg_controller_is_valid(controller, true))
 488                 return -EINVAL;
 489
 490         if (_unlikely_(!good)) {
 491                 int r;
 492
 493                 r = path_is_mount_point("/sys/fs/cgroup", false);
 494                 if (r <= 0)
 495                         return r < 0 ? r : -ENOENT;
 496
 497                 /* Cache this to save a few stat()s */
 498                 good = true;
 499         }
 500
 501         p = controller ? normalize_controller(controller) : NULL;
 502
 503         return join_path(p, path, suffix, fs);
 504 }
 505
 506 static int check_hierarchy(const char *p) {
 507         char *cc;
 508
 509         assert(p);
 510
 511         /* Check if this controller actually really exists */
 512         cc = alloca(sizeof("/sys/fs/cgroup/") + strlen(p));
 513         strcpy(stpcpy(cc, "/sys/fs/cgroup/"), p);
 514         if (access(cc, F_OK) < 0)
 515                 return -errno;
 516
 517         return 0;
 518 }
 519
 520 int cg_get_path_and_check(const char *controller, const char *path, const char *suffix, char **fs) {
 521         const char *p;
 522         int r;
 523
 524         assert(fs);
 525
 526         if (!cg_controller_is_valid(controller, true))
 527                 return -EINVAL;
 528
 529         /* Normalize the controller syntax */
 530         p = normalize_controller(controller);
 531
 532         /* Check if this controller actually really exists */
 533         r = check_hierarchy(p);
 534         if (r < 0)
 535                 return r;
 536
 537         return join_path(p, path, suffix, fs);
 538 }
 539
 540 static int trim_cb(const char *path, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
 541         assert(path);
 542         assert(sb);
 543         assert(ftwbuf);
 544
 545         if (typeflag != FTW_DP)
 546                 return 0;
 547
 548         if (ftwbuf->level < 1)
 549                 return 0;
 550
 551         rmdir(path);
 552         return 0;
 553 }
 554
 555 int cg_trim(const char *controller, const char *path, bool delete_root) {
 556         _cleanup_free_ char *fs = NULL;
 557         int r = 0;
 558
 559         assert(path);
 560
 561         r = cg_get_path(controller, path, NULL, &fs);
 562         if (r < 0)
 563                 return r;
 564
 565         errno = 0;
 566         if (nftw(fs, trim_cb, 64, FTW_DEPTH|FTW_MOUNT|FTW_PHYS) != 0)
 567                 r = errno ? -errno : -EIO;
 568
 569         if (delete_root) {
 570                 if (rmdir(fs) < 0 && errno != ENOENT)
 571                         return -errno;
 572         }
 573
 574         return r;
 575 }
 576
 577 int cg_delete(const char *controller, const char *path) {
 578         _cleanup_free_ char *parent = NULL;
 579         int r;
 580
 581         assert(path);
 582
 583         r = path_get_parent(path, &parent);
 584         if (r < 0)
 585                 return r;
 586
 587         r = cg_migrate_recursive(controller, path, controller, parent, false, true);
 588         return r == -ENOENT ? 0 : r;
 589 }
 590
 591 int cg_create(const char *controller, const char *path) {
 592         _cleanup_free_ char *fs = NULL;
 593         int r;
 594
 595         r = cg_get_path_and_check(controller, path, NULL, &fs);
 596         if (r < 0)
 597                 return r;
 598
 599         r = mkdir_parents(fs, 0755);
 600         if (r < 0)
 601                 return r;
 602
 603         if (mkdir(fs, 0755) < 0) {
 604
 605                 if (errno == EEXIST)
 606                         return 0;
 607
 608                 return -errno;
 609         }
 610
 611         return 1;
 612 }
 613
 614 int cg_create_and_attach(const char *controller, const char *path, pid_t pid) {
 615         int r, q;
 616
 617         assert(pid >= 0);
 618
 619         r = cg_create(controller, path);
 620         if (r < 0)
 621                 return r;
 622
 623         q = cg_attach(controller, path, pid);
 624         if (q < 0)
 625                 return q;
 626
 627         /* This does not remove the cgroup on failure */
 628         return r;
 629 }
 630
 631 int cg_attach(const char *controller, const char *path, pid_t pid) {
 632         _cleanup_free_ char *fs = NULL;
 633         char c[DECIMAL_STR_MAX(pid_t) + 2];
 634         int r;
 635
 636         assert(path);
 637         assert(pid >= 0);
 638
 639         r = cg_get_path_and_check(controller, path, "cgroup.procs", &fs);
 640         if (r < 0)
 641                 return r;
 642
 643         if (pid == 0)
 644                 pid = getpid();
 645
 646         snprintf(c, sizeof(c), "%lu\n", (unsigned long) pid);
 647
 648         return write_string_file(fs, c);
 649 }
 650
 651 int cg_attach_fallback(const char *controller, const char *path, pid_t pid) {
 652         int r;
 653
 654         assert(controller);
 655         assert(path);
 656         assert(pid >= 0);
 657
 658         r = cg_attach(controller, path, pid);
 659         if (r < 0) {
 660                 char prefix[strlen(path) + 1];
 661
 662                 /* This didn't work? Then let's try all prefixes of
 663                  * the destination */
 664
 665                 PATH_FOREACH_PREFIX(prefix, path) {
 666                         r = cg_attach(controller, prefix, pid);
 667                         if (r >= 0)
 668                                 break;
 669                 }
 670         }
 671
 672         return 0;
 673 }
 674
 675 int cg_set_group_access(
 676                 const char *controller,
 677                 const char *path,
 678                 mode_t mode,
 679                 uid_t uid,
 680                 gid_t gid) {
 681
 682         _cleanup_free_ char *fs = NULL;
 683         int r;
 684
 685         assert(path);
 686
 687         if (mode != (mode_t) -1)
 688                 mode &= 0777;
 689
 690         r = cg_get_path(controller, path, NULL, &fs);
 691         if (r < 0)
 692                 return r;
 693
 694         return chmod_and_chown(fs, mode, uid, gid);
 695 }
 696
 697 int cg_set_task_access(
 698                 const char *controller,
 699                 const char *path,
 700                 mode_t mode,
 701                 uid_t uid,
 702                 gid_t gid) {
 703
 704         _cleanup_free_ char *fs = NULL, *procs = NULL;
 705         int r;
 706
 707         assert(path);
 708
 709         if (mode == (mode_t) -1 && uid == (uid_t) -1 && gid == (gid_t) -1)
 710                 return 0;
 711
 712         if (mode != (mode_t) -1)
 713                 mode &= 0666;
 714
 715         r = cg_get_path(controller, path, "cgroup.procs", &fs);
 716         if (r < 0)
 717                 return r;
 718
 719         r = chmod_and_chown(fs, mode, uid, gid);
 720         if (r < 0)
 721                 return r;
 722
 723         /* Compatibility, Always keep values for "tasks" in sync with
 724          * "cgroup.procs" */
 725         r = cg_get_path(controller, path, "tasks", &procs);
 726         if (r < 0)
 727                 return r;
 728
 729         return chmod_and_chown(procs, mode, uid, gid);
 730 }
 731
 732 int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
 733         _cleanup_fclose_ FILE *f = NULL;
 734         char line[LINE_MAX];
 735         const char *fs;
 736         size_t cs;
 737
 738         assert(path);
 739         assert(pid >= 0);
 740
 741         if (controller) {
 742                 if (!cg_controller_is_valid(controller, true))
 743                         return -EINVAL;
 744
 745                 controller = normalize_controller(controller);
 746         } else
 747                 controller = SYSTEMD_CGROUP_CONTROLLER;
 748
 749         fs = procfs_file_alloca(pid, "cgroup");
 750
 751         f = fopen(fs, "re");
 752         if (!f)
 753                 return errno == ENOENT ? -ESRCH : -errno;
 754
 755         cs = strlen(controller);
 756
 757         FOREACH_LINE(line, f, return -errno) {
 758                 char *l, *p, *w, *e;
 759                 size_t k;
 760                 char *state;
 761                 bool found = false;
 762
 763                 truncate_nl(line);
 764
 765                 l = strchr(line, ':');
 766                 if (!l)
 767                         continue;
 768
 769                 l++;
 770                 e = strchr(l, ':');
 771                 if (!e)
 772                         continue;
 773
 774                 *e = 0;
 775
 776                 FOREACH_WORD_SEPARATOR(w, k, l, ",", state) {
 777
 778                         if (k == cs && memcmp(w, controller, cs) == 0) {
 779                                 found = true;
 780                                 break;
 781                         }
 782
 783                         if (k == 5 + cs &&
 784                             memcmp(w, "name=", 5) == 0 &&
 785                             memcmp(w+5, controller, cs) == 0) {
 786                                 found = true;
 787                                 break;
 788                         }
 789                 }
 790
 791                 if (!found)
 792                         continue;
 793
 794                 p = strdup(e + 1);
 795                 if (!p)
 796                         return -ENOMEM;
 797
 798                 *path = p;
 799                 return 0;
 800         }
 801
 802         return -ENOENT;
 803 }
 804
 805 int cg_install_release_agent(const char *controller, const char *agent) {
 806         _cleanup_free_ char *fs = NULL, *contents = NULL;
 807         char *sc;
 808         int r;
 809
 810         assert(agent);
 811
 812         r = cg_get_path(controller, NULL, "release_agent", &fs);
 813         if (r < 0)
 814                 return r;
 815
 816         r = read_one_line_file(fs, &contents);
 817         if (r < 0)
 818                 return r;
 819
 820         sc = strstrip(contents);
 821         if (sc[0] == 0) {
 822                 r = write_string_file(fs, agent);
 823                 if (r < 0)
 824                         return r;
 825         } else if (!streq(sc, agent))
 826                 return -EEXIST;
 827
 828         free(fs);
 829         fs = NULL;
 830         r = cg_get_path(controller, NULL, "notify_on_release", &fs);
 831         if (r < 0)
 832                 return r;
 833
 834         free(contents);
 835         contents = NULL;
 836         r = read_one_line_file(fs, &contents);
 837         if (r < 0)
 838                 return r;
 839
 840         sc = strstrip(contents);
 841         if (streq(sc, "0")) {
 842                 r = write_string_file(fs, "1");
 843                 if (r < 0)
 844                         return r;
 845
 846                 return 1;
 847         }
 848
 849         if (!streq(sc, "1"))
 850                 return -EIO;
 851
 852         return 0;
 853 }
 854
 855 int cg_uninstall_release_agent(const char *controller) {
 856         _cleanup_free_ char *fs = NULL;
 857         int r;
 858
 859         r = cg_get_path(controller, NULL, "notify_on_release", &fs);
 860         if (r < 0)
 861                 return r;
 862
 863         r = write_string_file(fs, "0");
 864         if (r < 0)
 865                 return r;
 866
 867         free(fs);
 868         fs = NULL;
 869
 870         r = cg_get_path(controller, NULL, "release_agent", &fs);
 871         if (r < 0)
 872                 return r;
 873
 874         r = write_string_file(fs, "");
 875         if (r < 0)
 876                 return r;
 877
 878         return 0;
 879 }
 880
 881 int cg_is_empty(const char *controller, const char *path, bool ignore_self) {
 882         _cleanup_fclose_ FILE *f = NULL;
 883         pid_t pid = 0, self_pid;
 884         bool found = false;
 885         int r;
 886
 887         assert(path);
 888
 889         r = cg_enumerate_processes(controller, path, &f);
 890         if (r < 0)
 891                 return r == -ENOENT ? 1 : r;
 892
 893         self_pid = getpid();
 894
 895         while ((r = cg_read_pid(f, &pid)) > 0) {
 896
 897                 if (ignore_self && pid == self_pid)
 898                         continue;
 899
 900                 found = true;
 901                 break;
 902         }
 903
 904         if (r < 0)
 905                 return r;
 906
 907         return !found;
 908 }
 909
 910 int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_self) {
 911         _cleanup_closedir_ DIR *d = NULL;
 912         char *fn;
 913         int r;
 914
 915         assert(path);
 916
 917         r = cg_is_empty(controller, path, ignore_self);
 918         if (r <= 0)
 919                 return r;
 920
 921         r = cg_enumerate_subgroups(controller, path, &d);
 922         if (r < 0)
 923                 return r == -ENOENT ? 1 : r;
 924
 925         while ((r = cg_read_subgroup(d, &fn)) > 0) {
 926                 _cleanup_free_ char *p = NULL;
 927
 928                 p = strjoin(path, "/", fn, NULL);
 929                 free(fn);
 930                 if (!p)
 931                         return -ENOMEM;
 932
 933                 r = cg_is_empty_recursive(controller, p, ignore_self);
 934                 if (r <= 0)
 935                         return r;
 936         }
 937
 938         if (r < 0)
 939                 return r;
 940
 941         return 1;
 942 }
 943
 944 int cg_split_spec(const char *spec, char **controller, char **path) {
 945         const char *e;
 946         char *t = NULL, *u = NULL;
 947         _cleanup_free_ char *v = NULL;
 948
 949         assert(spec);
 950
 951         if (*spec == '/') {
 952                 if (!path_is_safe(spec))
 953                         return -EINVAL;
 954
 955                 if (path) {
 956                         t = strdup(spec);
 957                         if (!t)
 958                                 return -ENOMEM;
 959
 960                         path_kill_slashes(t);
 961                         *path = t;
 962                 }
 963
 964                 if (controller)
 965                         *controller = NULL;
 966
 967                 return 0;
 968         }
 969
 970         e = strchr(spec, ':');
 971         if (!e) {
 972                 if (!cg_controller_is_valid(spec, true))
 973                         return -EINVAL;
 974
 975                 if (controller) {
 976                         t = strdup(normalize_controller(spec));
 977                         if (!t)
 978                                 return -ENOMEM;
 979
 980                         *controller = t;
 981                 }
 982
 983                 if (path)
 984                         *path = NULL;
 985
 986                 return 0;
 987         }
 988
 989         v = strndup(spec, e-spec);
 990         if (!v)
 991                 return -ENOMEM;
 992         t = strdup(normalize_controller(v));
 993         if (!t)
 994                 return -ENOMEM;
 995         if (!cg_controller_is_valid(t, true)) {
 996                 free(t);
 997                 return -EINVAL;
 998         }
 999
1000         if (streq(e+1, "")) {
1001                 u = strdup("/");
1002                 if (!u) {
1003                         free(t);
1004                         return -ENOMEM;
1005                 }
1006         } else {
1007                 u = strdup(e+1);
1008                 if (!u) {
1009                         free(t);
1010                         return -ENOMEM;
1011                 }
1012
1013                 if (!path_is_safe(u) ||
1014                     !path_is_absolute(u)) {
1015                         free(t);
1016                         free(u);
1017                         return -EINVAL;
1018                 }
1019
1020                 path_kill_slashes(u);
1021         }
1022
1023         if (controller)
1024                 *controller = t;
1025         else
1026                 free(t);
1027
1028         if (path)
1029                 *path = u;
1030         else
1031                 free(u);
1032
1033         return 0;
1034 }
1035
1036 int cg_mangle_path(const char *path, char **result) {
1037         _cleanup_free_ char *c = NULL, *p = NULL;
1038         char *t;
1039         int r;
1040
1041         assert(path);
1042         assert(result);
1043
1044         /* First check if it already is a filesystem path */
1045         if (path_startswith(path, "/sys/fs/cgroup")) {
1046
1047                 t = strdup(path);
1048                 if (!t)
1049                         return -ENOMEM;
1050
1051                 path_kill_slashes(t);
1052                 *result = t;
1053                 return 0;
1054         }
1055
1056         /* Otherwise treat it as cg spec */
1057         r = cg_split_spec(path, &c, &p);
1058         if (r < 0)
1059                 return r;
1060
1061         return cg_get_path(c ? c : SYSTEMD_CGROUP_CONTROLLER, p ? p : "/", NULL, result);
1062 }
1063
1064 int cg_get_root_path(char **path) {
1065         char *p, *e;
1066         int r;
1067
1068         assert(path);
1069
1070         r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 1, &p);
1071         if (r < 0)
1072                 return r;
1073
1074         e = endswith(p, "/" SPECIAL_SYSTEM_SLICE);
1075         if (e)
1076                 *e = 0;
1077
1078         *path = p;
1079         return 0;
1080 }
1081
1082 int cg_shift_path(const char *cgroup, const char *root, const char **shifted) {
1083         _cleanup_free_ char *rt = NULL;
1084         char *p;
1085         int r;
1086
1087         assert(cgroup);
1088         assert(shifted);
1089
1090         if (!root) {
1091                 /* If the root was specified let's use that, otherwise
1092                  * let's determine it from PID 1 */
1093
1094                 r = cg_get_root_path(&rt);
1095                 if (r < 0)
1096                         return r;
1097
1098                 root = rt;
1099         }
1100
1101         p = path_startswith(cgroup, root);
1102         if (p)
1103                 *shifted = p - 1;
1104         else
1105                 *shifted = cgroup;
1106
1107         return 0;
1108 }
1109
1110 int cg_pid_get_path_shifted(pid_t pid, const char *root, char **cgroup) {
1111         _cleanup_free_ char *raw = NULL;
1112         const char *c;
1113         int r;
1114
1115         assert(pid >= 0);
1116         assert(cgroup);
1117
1118         r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &raw);
1119         if (r < 0)
1120                 return r;
1121
1122         r = cg_shift_path(raw, root, &c);
1123         if (r < 0)
1124                 return r;
1125
1126         if (c == raw) {
1127                 *cgroup = raw;
1128                 raw = NULL;
1129         } else {
1130                 char *n;
1131
1132                 n = strdup(c);
1133                 if (!n)
1134                         return -ENOMEM;
1135
1136                 *cgroup = n;
1137         }
1138
1139         return 0;
1140 }
1141
1142 int cg_path_decode_unit(const char *cgroup, char **unit){
1143         char *e, *c, *s;
1144
1145         assert(cgroup);
1146         assert(unit);
1147
1148         e = strchrnul(cgroup, '/');
1149         c = strndupa(cgroup, e - cgroup);
1150         c = cg_unescape(c);
1151
1152         if (!unit_name_is_valid(c, TEMPLATE_INVALID))
1153                 return -EINVAL;
1154
1155         s = strdup(c);
1156         if (!s)
1157                 return -ENOMEM;
1158
1159         *unit = s;
1160         return 0;
1161 }
1162
1163 static const char *skip_slices(const char *p) {
1164         /* Skips over all slice assignments */
1165
1166         for (;;) {
1167                 size_t n;
1168
1169                 p += strspn(p, "/");
1170
1171                 n = strcspn(p, "/");
1172                 if (n <= 6 || memcmp(p + n - 6, ".slice", 6) != 0)
1173                         return p;
1174
1175                 p += n;
1176         }
1177 }
1178
1179 int cg_path_get_unit(const char *path, char **unit) {
1180         const char *e;
1181
1182         assert(path);
1183         assert(unit);
1184
1185         e = skip_slices(path);
1186
1187         return cg_path_decode_unit(e, unit);
1188 }
1189
1190 int cg_pid_get_unit(pid_t pid, char **unit) {
1191         _cleanup_free_ char *cgroup = NULL;
1192         int r;
1193
1194         assert(unit);
1195
1196         r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
1197         if (r < 0)
1198                 return r;
1199
1200         return cg_path_get_unit(cgroup, unit);
1201 }
1202
1203 /**
1204  * Skip session-*.scope, but require it to be there.
1205  */
1206 static const char *skip_session(const char *p) {
1207         size_t n;
1208
1209         assert(p);
1210
1211         p += strspn(p, "/");
1212
1213         n = strcspn(p, "/");
1214         if (n < strlen("session-x.scope") || memcmp(p, "session-", 8) != 0 || memcmp(p + n - 6, ".scope", 6) != 0)
1215                 return NULL;
1216
1217         p += n;
1218         p += strspn(p, "/");
1219
1220         return p;
1221 }
1222
1223 /**
1224  * Skip user@*.service, but require it to be there.
1225  */
1226 static const char *skip_user_manager(const char *p) {
1227         size_t n;
1228
1229         assert(p);
1230
1231         p += strspn(p, "/");
1232
1233         n = strcspn(p, "/");
1234         if (n < strlen("user@x.service") || memcmp(p, "user@", 5) != 0 || memcmp(p + n - 8, ".service", 8) != 0)
1235                 return NULL;
1236
1237         p += n;
1238         p += strspn(p, "/");
1239
1240         return p;
1241 }
1242
1243 int cg_path_get_user_unit(const char *path, char **unit) {
1244         const char *e, *t;
1245
1246         assert(path);
1247         assert(unit);
1248
1249         /* We always have to parse the path from the beginning as unit
1250          * cgroups might have arbitrary child cgroups and we shouldn't get
1251          * confused by those */
1252
1253         /* Skip slices, if there are any */
1254         e = skip_slices(path);
1255
1256         /* Skip the session scope... */
1257         t = skip_session(e);
1258         if (t)
1259                 /* ... and skip more slices if there's one */
1260                 e = skip_slices(t);
1261         else {
1262                 /* ... or require a user manager unit to be there */
1263                 e = skip_user_manager(e);
1264                 if (!e)
1265                         return -ENOENT;
1266         }
1267
1268         return cg_path_decode_unit(e, unit);
1269 }
1270
1271 int cg_pid_get_user_unit(pid_t pid, char **unit) {
1272         _cleanup_free_ char *cgroup = NULL;
1273         int r;
1274
1275         assert(unit);
1276
1277         r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
1278         if (r < 0)
1279                 return r;
1280
1281         return cg_path_get_user_unit(cgroup, unit);
1282 }
1283
1284 int cg_path_get_machine_name(const char *path, char **machine) {
1285         const char *e, *n, *x;
1286         char *s, *r;
1287         size_t l;
1288
1289         assert(path);
1290         assert(machine);
1291
1292         /* Skip slices, if there are any */
1293         e = skip_slices(path);
1294
1295         n = strchrnul(e, '/');
1296         if (e == n)
1297                 return -ENOENT;
1298
1299         s = strndupa(e, n - e);
1300         s = cg_unescape(s);
1301
1302         x = startswith(s, "machine-");
1303         if (!x)
1304                 return -ENOENT;
1305         if (!endswith(x, ".scope"))
1306                 return -ENOENT;
1307
1308         l = strlen(x);
1309         if (l <= 6)
1310                 return -ENOENT;
1311
1312         r = strndup(x, l - 6);
1313         if (!r)
1314                 return -ENOMEM;
1315
1316         *machine = r;
1317         return 0;
1318 }
1319
1320 int cg_pid_get_machine_name(pid_t pid, char **machine) {
1321         _cleanup_free_ char *cgroup = NULL;
1322         int r;
1323
1324         assert(machine);
1325
1326         r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
1327         if (r < 0)
1328                 return r;
1329
1330         return cg_path_get_machine_name(cgroup, machine);
1331 }
1332
1333 int cg_path_get_session(const char *path, char **session) {
1334         const char *e, *n, *x;
1335         char *s;
1336         size_t l;
1337
1338         assert(path);
1339
1340         /* Skip slices, if there are any */
1341         e = skip_slices(path);
1342
1343         n = strchrnul(e, '/');
1344         if (e == n)
1345                 return -ENOENT;
1346
1347         s = strndupa(e, n - e);
1348         s = cg_unescape(s);
1349
1350         x = startswith(s, "session-");
1351         if (!x)
1352                 return -ENOENT;
1353         if (!endswith(x, ".scope"))
1354                 return -ENOENT;
1355
1356         l = strlen(x);
1357         if (l <= 6)
1358                 return -ENOENT;
1359
1360         if (session) {
1361                 char *r;
1362
1363                 r = strndup(x, l - 6);
1364                 if (!r)
1365                         return -ENOMEM;
1366
1367                 *session = r;
1368         }
1369
1370         return 0;
1371 }
1372
1373 int cg_pid_get_session(pid_t pid, char **session) {
1374         _cleanup_free_ char *cgroup = NULL;
1375         int r;
1376
1377         r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
1378         if (r < 0)
1379                 return r;
1380
1381         return cg_path_get_session(cgroup, session);
1382 }
1383
1384 int cg_path_get_owner_uid(const char *path, uid_t *uid) {
1385         _cleanup_free_ char *slice = NULL;
1386         const char *start, *end;
1387         char *s;
1388         uid_t u;
1389         int r;
1390
1391         assert(path);
1392
1393         r = cg_path_get_slice(path, &slice);
1394         if (r < 0)
1395                 return r;
1396
1397         start = startswith(slice, "user-");
1398         if (!start)
1399                 return -ENOENT;
1400         end = endswith(slice, ".slice");
1401         if (!end)
1402                 return -ENOENT;
1403
1404         s = strndupa(start, end - start);
1405         if (!s)
1406                 return -ENOENT;
1407
1408         if (parse_uid(s, &u) < 0)
1409                 return -EIO;
1410
1411         if (uid)
1412                 *uid = u;
1413
1414         return 0;
1415 }
1416
1417 int cg_pid_get_owner_uid(pid_t pid, uid_t *uid) {
1418         _cleanup_free_ char *cgroup = NULL;
1419         int r;
1420
1421         r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
1422         if (r < 0)
1423                 return r;
1424
1425         return cg_path_get_owner_uid(cgroup, uid);
1426 }
1427
1428 int cg_path_get_slice(const char *p, char **slice) {
1429         const char *e = NULL;
1430         size_t m = 0;
1431
1432         assert(p);
1433         assert(slice);
1434
1435         for (;;) {
1436                 size_t n;
1437
1438                 p += strspn(p, "/");
1439
1440                 n = strcspn(p, "/");
1441                 if (n <= 6 || memcmp(p + n - 6, ".slice", 6) != 0) {
1442                         char *s;
1443
1444                         if (!e)
1445                                 return -ENOENT;
1446
1447                         s = strndup(e, m);
1448                         if (!s)
1449                                 return -ENOMEM;
1450
1451                         *slice = s;
1452                         return 0;
1453                 }
1454
1455                 e = p;
1456                 m = n;
1457
1458                 p += n;
1459         }
1460 }
1461
1462 int cg_pid_get_slice(pid_t pid, char **slice) {
1463         _cleanup_free_ char *cgroup = NULL;
1464         int r;
1465
1466         assert(slice);
1467
1468         r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
1469         if (r < 0)
1470                 return r;
1471
1472         return cg_path_get_slice(cgroup, slice);
1473 }
1474
1475 char *cg_escape(const char *p) {
1476         bool need_prefix = false;
1477
1478         /* This implements very minimal escaping for names to be used
1479          * as file names in the cgroup tree: any name which might
1480          * conflict with a kernel name or is prefixed with '_' is
1481          * prefixed with a '_'. That way, when reading cgroup names it
1482          * is sufficient to remove a single prefixing underscore if
1483          * there is one. */
1484
1485         /* The return value of this function (unlike cg_unescape())
1486          * needs free()! */
1487
1488         if (p[0] == 0 ||
1489             p[0] == '_' ||
1490             p[0] == '.' ||
1491             streq(p, "notify_on_release") ||
1492             streq(p, "release_agent") ||
1493             streq(p, "tasks"))
1494                 need_prefix = true;
1495         else {
1496                 const char *dot;
1497
1498                 dot = strrchr(p, '.');
1499                 if (dot) {
1500
1501                         if (dot - p == 6 && memcmp(p, "cgroup", 6) == 0)
1502                                 need_prefix = true;
1503                         else {
1504                                 char *n;
1505
1506                                 n = strndupa(p, dot - p);
1507
1508                                 if (check_hierarchy(n) >= 0)
1509                                         need_prefix = true;
1510                         }
1511                 }
1512         }
1513
1514         if (need_prefix)
1515                 return strappend("_", p);
1516         else
1517                 return strdup(p);
1518 }
1519
1520 char *cg_unescape(const char *p) {
1521         assert(p);
1522
1523         /* The return value of this function (unlike cg_escape())
1524          * doesn't need free()! */
1525
1526         if (p[0] == '_')
1527                 return (char*) p+1;
1528
1529         return (char*) p;
1530 }
1531
1532 #define CONTROLLER_VALID                        \
1533         DIGITS LETTERS                          \
1534         "_"
1535
1536 bool cg_controller_is_valid(const char *p, bool allow_named) {
1537         const char *t, *s;
1538
1539         if (!p)
1540                 return false;
1541
1542         if (allow_named) {
1543                 s = startswith(p, "name=");
1544                 if (s)
1545                         p = s;
1546         }
1547
1548         if (*p == 0 || *p == '_')
1549                 return false;
1550
1551         for (t = p; *t; t++)
1552                 if (!strchr(CONTROLLER_VALID, *t))
1553                         return false;
1554
1555         if (t - p > FILENAME_MAX)
1556                 return false;
1557
1558         return true;
1559 }
1560
1561 int cg_slice_to_path(const char *unit, char **ret) {
1562         _cleanup_free_ char *p = NULL, *s = NULL, *e = NULL;
1563         const char *dash;
1564
1565         assert(unit);
1566         assert(ret);
1567
1568         if (!unit_name_is_valid(unit, TEMPLATE_INVALID))
1569                 return -EINVAL;
1570
1571         if (!endswith(unit, ".slice"))
1572                 return -EINVAL;
1573
1574         p = unit_name_to_prefix(unit);
1575         if (!p)
1576                 return -ENOMEM;
1577
1578         dash = strchr(p, '-');
1579         while (dash) {
1580                 _cleanup_free_ char *escaped = NULL;
1581                 char n[dash - p + sizeof(".slice")];
1582
1583                 strcpy(stpncpy(n, p, dash - p), ".slice");
1584
1585                 if (!unit_name_is_valid(n, TEMPLATE_INVALID))
1586                         return -EINVAL;
1587
1588                 escaped = cg_escape(n);
1589                 if (!escaped)
1590                         return -ENOMEM;
1591
1592                 if (!strextend(&s, escaped, "/", NULL))
1593                         return -ENOMEM;
1594
1595                 dash = strchr(dash+1, '-');
1596         }
1597
1598         e = cg_escape(unit);
1599         if (!e)
1600                 return -ENOMEM;
1601
1602         if (!strextend(&s, e, NULL))
1603                 return -ENOMEM;
1604
1605         *ret = s;
1606         s = NULL;
1607
1608         return 0;
1609 }
1610
1611 int cg_set_attribute(const char *controller, const char *path, const char *attribute, const char *value) {
1612         _cleanup_free_ char *p = NULL;
1613         int r;
1614
1615         r = cg_get_path(controller, path, attribute, &p);
1616         if (r < 0)
1617                 return r;
1618
1619         return write_string_file(p, value);
1620 }
1621
1622 static const char mask_names[] =
1623         "cpu\0"
1624         "cpuacct\0"
1625         "blkio\0"
1626         "memory\0"
1627         "devices\0";
1628
1629 int cg_create_everywhere(CGroupControllerMask supported, CGroupControllerMask mask, const char *path) {
1630         CGroupControllerMask bit = 1;
1631         const char *n;
1632         int r;
1633
1634         /* This one will create a cgroup in our private tree, but also
1635          * duplicate it in the trees specified in mask, and remove it
1636          * in all others */
1637
1638         /* First create the cgroup in our own hierarchy. */
1639         r = cg_create(SYSTEMD_CGROUP_CONTROLLER, path);
1640         if (r < 0)
1641                 return r;
1642
1643         /* Then, do the same in the other hierarchies */
1644         NULSTR_FOREACH(n, mask_names) {
1645                 if (mask & bit)
1646                         cg_create(n, path);
1647                 else if (supported & bit)
1648                         cg_trim(n, path, true);
1649
1650                 bit <<= 1;
1651         }
1652
1653         return 0;
1654 }
1655
1656 int cg_attach_everywhere(CGroupControllerMask supported, const char *path, pid_t pid) {
1657         CGroupControllerMask bit = 1;
1658         const char *n;
1659         int r;
1660
1661         r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, path, pid);
1662         if (r < 0)
1663                 return r;
1664
1665         NULSTR_FOREACH(n, mask_names) {
1666                 if (supported & bit)
1667                         cg_attach_fallback(n, path, pid);
1668
1669                 bit <<= 1;
1670         }
1671
1672         return 0;
1673 }
1674
1675 int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path, Set* pids) {
1676         Iterator i;
1677         void *pidp;
1678         int r = 0;
1679
1680         SET_FOREACH(pidp, pids, i) {
1681                 pid_t pid = PTR_TO_LONG(pidp);
1682                 int q;
1683
1684                 q = cg_attach_everywhere(supported, path, pid);
1685                 if (q < 0)
1686                         r = q;
1687         }
1688
1689         return r;
1690 }
1691
1692 int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to) {
1693         CGroupControllerMask bit = 1;
1694         const char *n;
1695         int r;
1696
1697         if (!path_equal(from, to))  {
1698                 r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, from, SYSTEMD_CGROUP_CONTROLLER, to, false, true);
1699                 if (r < 0)
1700                         return r;
1701         }
1702
1703         NULSTR_FOREACH(n, mask_names) {
1704                 if (supported & bit)
1705                         cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, n, to, false, false);
1706
1707                 bit <<= 1;
1708         }
1709
1710         return 0;
1711 }
1712
1713 int cg_trim_everywhere(CGroupControllerMask supported, const char *path, bool delete_root) {
1714         CGroupControllerMask bit = 1;
1715         const char *n;
1716         int r;
1717
1718         r = cg_trim(SYSTEMD_CGROUP_CONTROLLER, path, delete_root);
1719         if (r < 0)
1720                 return r;
1721
1722         NULSTR_FOREACH(n, mask_names) {
1723                 if (supported & bit)
1724                         cg_trim(n, path, delete_root);
1725
1726                 bit <<= 1;
1727         }
1728
1729         return 0;
1730 }
1731
1732 CGroupControllerMask cg_mask_supported(void) {
1733         CGroupControllerMask bit = 1, mask = 0;
1734         const char *n;
1735
1736         NULSTR_FOREACH(n, mask_names) {
1737                 if (check_hierarchy(n) >= 0)
1738                         mask |= bit;
1739
1740                 bit <<= 1;
1741         }
1742
1743         return mask;
1744 }