src/pam-module.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 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 <errno.h>
  23 #include <fcntl.h>
  24 #include <sys/file.h>
  25 #include <pwd.h>
  26 #include <endian.h>
  27
  28 #include <security/pam_modules.h>
  29 #include <security/_pam_macros.h>
  30 #include <security/pam_modutil.h>
  31 #include <security/pam_ext.h>
  32 #include <security/pam_misc.h>
  33
  34 #include "util.h"
  35 #include "cgroup-util.h"
  36 #include "macro.h"
  37 #include "sd-daemon.h"
  38 #include "strv.h"
  39
  40 static int parse_argv(pam_handle_t *handle,
  41                       int argc, const char **argv,
  42                       bool *create_session,
  43                       bool *kill_session,
  44                       bool *kill_user,
  45                       char ***controllers,
  46                       char ***reset_controllers,
  47                       char ***kill_only_users,
  48                       char ***kill_exclude_users) {
  49
  50         unsigned i;
  51         bool reset_controller_set = false;
  52         bool kill_exclude_users_set = false;
  53
  54         assert(argc >= 0);
  55         assert(argc == 0 || argv);
  56
  57         for (i = 0; i < (unsigned) argc; i++) {
  58                 int k;
  59
  60                 if (startswith(argv[i], "create-session=")) {
  61                         if ((k = parse_boolean(argv[i] + 15)) < 0) {
  62                                 pam_syslog(handle, LOG_ERR, "Failed to parse create-session= argument.");
  63                                 return k;
  64                         }
  65
  66                         if (create_session)
  67                                 *create_session = k;
  68
  69                 } else if (startswith(argv[i], "kill-session=")) {
  70                         if ((k = parse_boolean(argv[i] + 13)) < 0) {
  71                                 pam_syslog(handle, LOG_ERR, "Failed to parse kill-session= argument.");
  72                                 return k;
  73                         }
  74
  75                         if (kill_session)
  76                                 *kill_session = k;
  77
  78                 } else if (startswith(argv[i], "kill-user=")) {
  79                         if ((k = parse_boolean(argv[i] + 10)) < 0) {
  80                                 pam_syslog(handle, LOG_ERR, "Failed to parse kill-user= argument.");
  81                                 return k;
  82                         }
  83
  84                         if (kill_user)
  85                                 *kill_user = k;
  86
  87                 } else if (startswith(argv[i], "controllers=")) {
  88
  89                         if (controllers) {
  90                                 char **l;
  91
  92                                 if (!(l = strv_split(argv[i] + 12, ","))) {
  93                                         pam_syslog(handle, LOG_ERR, "Out of memory.");
  94                                         return -ENOMEM;
  95                                 }
  96
  97                                 strv_free(*controllers);
  98                                 *controllers = l;
  99                         }
 100
 101                 } else if (startswith(argv[i], "reset-controllers=")) {
 102
 103                         if (reset_controllers) {
 104                                 char **l;
 105
 106                                 if (!(l = strv_split(argv[i] + 18, ","))) {
 107                                         pam_syslog(handle, LOG_ERR, "Out of memory.");
 108                                         return -ENOMEM;
 109                                 }
 110
 111                                 strv_free(*reset_controllers);
 112                                 *reset_controllers = l;
 113                         }
 114
 115                         reset_controller_set = true;
 116
 117                 } else if (startswith(argv[i], "kill-only-users=")) {
 118
 119                         if (kill_only_users) {
 120                                 char **l;
 121
 122                                 if (!(l = strv_split(argv[i] + 16, ","))) {
 123                                         pam_syslog(handle, LOG_ERR, "Out of memory.");
 124                                         return -ENOMEM;
 125                                 }
 126
 127                                 strv_free(*kill_only_users);
 128                                 *kill_only_users = l;
 129                         }
 130
 131                 } else if (startswith(argv[i], "kill-exclude-users=")) {
 132
 133                         if (kill_exclude_users) {
 134                                 char **l;
 135
 136                                 if (!(l = strv_split(argv[i] + 19, ","))) {
 137                                         pam_syslog(handle, LOG_ERR, "Out of memory.");
 138                                         return -ENOMEM;
 139                                 }
 140
 141                                 strv_free(*kill_exclude_users);
 142                                 *kill_exclude_users = l;
 143                         }
 144
 145                         kill_exclude_users_set = true;
 146
 147                 } else {
 148                         pam_syslog(handle, LOG_ERR, "Unknown parameter '%s'.", argv[i]);
 149                         return -EINVAL;
 150                 }
 151         }
 152
 153         if (!reset_controller_set && reset_controllers) {
 154                 char **l;
 155
 156                 if (!(l = strv_new("cpu", NULL))) {
 157                         pam_syslog(handle, LOG_ERR, "Out of memory");
 158                         return -ENOMEM;
 159                 }
 160
 161                 *reset_controllers = l;
 162         }
 163
 164         if (controllers)
 165                 strv_remove(*controllers, "name=systemd");
 166
 167         if (reset_controllers)
 168                 strv_remove(*reset_controllers, "name=systemd");
 169
 170         if (kill_session && *kill_session && kill_user)
 171                 *kill_user = true;
 172
 173         if (!kill_exclude_users_set && kill_exclude_users) {
 174                 char **l;
 175
 176                 if (!(l = strv_new("root", NULL))) {
 177                         pam_syslog(handle, LOG_ERR, "Out of memory");
 178                         return -ENOMEM;
 179                 }
 180
 181                 *kill_exclude_users = l;
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int open_file_and_lock(const char *fn) {
 188         int fd;
 189
 190         assert(fn);
 191
 192         if ((fd = open(fn, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW|O_CREAT, 0600)) < 0)
 193                 return -errno;
 194
 195         /* The BSD socket semantics are a lot nicer than those of
 196          * POSIX locks. Which is why we use flock() here. BSD locking
 197          * does not work across NFS which however is not needed here
 198          * as the filesystems in question should be local, and only
 199          * locally accessible, and most likely even tmpfs. */
 200
 201         if (flock(fd, LOCK_EX) < 0) {
 202                 close_nointr_nofail(fd);
 203                 return -errno;
 204         }
 205
 206         return fd;
 207 }
 208
 209 enum {
 210         SESSION_ID_AUDIT = 'a',
 211         SESSION_ID_COUNTER = 'c',
 212         SESSION_ID_RANDOM = 'r'
 213 };
 214
 215 static uint64_t get_session_id(int *mode) {
 216         char *s;
 217         int fd;
 218
 219         assert(mode);
 220
 221         /* First attempt: let's use the session ID of the audit
 222          * system, if it is available. */
 223         if (read_one_line_file("/proc/self/sessionid", &s) >= 0) {
 224                 uint32_t u;
 225                 int r;
 226
 227                 r = safe_atou32(s, &u);
 228                 free(s);
 229
 230                 if (r >= 0 && u != (uint32_t) -1 && u > 0) {
 231                         *mode = SESSION_ID_AUDIT;
 232                         return (uint64_t) u;
 233                 }
 234         }
 235
 236         /* Second attempt, use our own counter. */
 237         if ((fd = open_file_and_lock(RUNTIME_DIR "/user/.pam-systemd-session")) >= 0) {
 238                 uint64_t counter;
 239                 ssize_t r;
 240
 241                 /* We do a bit of endianess swapping here, just to be
 242                  * sure. /var should be machine specific anyway, and
 243                  * /var/run even mounted from tmpfs, so this
 244                  * byteswapping should really not be necessary. But
 245                  * then again, you never know, so let's avoid any
 246                  * risk. */
 247
 248                 if (loop_read(fd, &counter, sizeof(counter), false) != sizeof(counter))
 249                         counter = 1;
 250                 else
 251                         counter = le64toh(counter) + 1;
 252
 253                 if (lseek(fd, 0, SEEK_SET) == 0) {
 254                         uint64_t swapped = htole64(counter);
 255
 256                         r = loop_write(fd, &swapped, sizeof(swapped), false);
 257
 258                         if (r != sizeof(swapped))
 259                                 r = -EIO;
 260                 } else
 261                         r = -errno;
 262
 263                 close_nointr_nofail(fd);
 264
 265                 if (r >= 0) {
 266                         *mode = SESSION_ID_COUNTER;
 267                         return counter;
 268                 }
 269         }
 270
 271         *mode = SESSION_ID_RANDOM;
 272
 273         /* Last attempt, pick a random value */
 274         return (uint64_t) random_ull();
 275 }
 276
 277 static int get_user_data(
 278                 pam_handle_t *handle,
 279                 const char **ret_username,
 280                 struct passwd **ret_pw) {
 281
 282         const char *username = NULL;
 283         struct passwd *pw = NULL;
 284         int r;
 285         bool have_loginuid = false;
 286         char *s;
 287
 288         assert(handle);
 289         assert(ret_username);
 290         assert(ret_pw);
 291
 292         if (read_one_line_file("/proc/self/loginuid", &s) >= 0) {
 293                 uint32_t u;
 294
 295                 r = safe_atou32(s, &u);
 296                 free(s);
 297
 298                 if (r >= 0 && u != (uint32_t) -1 && u > 0) {
 299                         have_loginuid = true;
 300                         pw = pam_modutil_getpwuid(handle, u);
 301                 }
 302         }
 303
 304         if (!have_loginuid) {
 305                 if ((r = pam_get_user(handle, &username, NULL)) != PAM_SUCCESS) {
 306                         pam_syslog(handle, LOG_ERR, "Failed to get user name.");
 307                         return r;
 308                 }
 309
 310                 if (!username || !*username) {
 311                         pam_syslog(handle, LOG_ERR, "User name not valid.");
 312                         return PAM_AUTH_ERR;
 313                 }
 314
 315                 pw = pam_modutil_getpwnam(handle, username);
 316         }
 317
 318         if (!pw) {
 319                 pam_syslog(handle, LOG_ERR, "Failed to get user data.");
 320                 return PAM_USER_UNKNOWN;
 321         }
 322
 323         *ret_pw = pw;
 324         *ret_username = username ? username : pw->pw_name;
 325
 326         return PAM_SUCCESS;
 327 }
 328
 329 static int create_user_group(
 330                 pam_handle_t *handle,
 331                 const char *controller,
 332                 const char *group,
 333                 struct passwd *pw,
 334                 bool attach,
 335                 bool remember) {
 336
 337         int r;
 338
 339         assert(handle);
 340         assert(group);
 341
 342         if (attach)
 343                 r = cg_create_and_attach(controller, group, 0);
 344         else
 345                 r = cg_create(controller, group);
 346
 347         if (r < 0) {
 348                 pam_syslog(handle, LOG_ERR, "Failed to create cgroup: %s", strerror(-r));
 349                 return PAM_SESSION_ERR;
 350         }
 351
 352         if (r > 0 && remember) {
 353                 /* Remember that it was us who created this group, and
 354                  * that hence we need to remove it too. This is a
 355                  * protection against removing the cgroup when run
 356                  * recursively. */
 357                 if ((r = pam_set_data(handle, "systemd.created", INT_TO_PTR(1), NULL)) != PAM_SUCCESS) {
 358                         pam_syslog(handle, LOG_ERR, "Failed to install created variable.");
 359                         return r;
 360                 }
 361         }
 362
 363         if ((r = cg_set_task_access(controller, group, 0644, pw->pw_uid, pw->pw_gid)) < 0 ||
 364             (r = cg_set_group_access(controller, group, 0755, pw->pw_uid, pw->pw_gid)) < 0) {
 365                 pam_syslog(handle, LOG_ERR, "Failed to change access modes: %s", strerror(-r));
 366                 return PAM_SESSION_ERR;
 367         }
 368
 369         return PAM_SUCCESS;
 370 }
 371
 372 static int reset_group(
 373                 pam_handle_t *handle,
 374                 const char *controller) {
 375
 376         int r;
 377
 378         assert(handle);
 379
 380         if ((r = cg_attach(controller, "/", 0)) < 0) {
 381                 pam_syslog(handle, LOG_ERR, "Failed to reset cgroup for controller %s: %s", controller, strerror(-r));
 382                 return PAM_SESSION_ERR;
 383         }
 384
 385         return PAM_SUCCESS;
 386 }
 387
 388 _public_ PAM_EXTERN int pam_sm_open_session(
 389                 pam_handle_t *handle,
 390                 int flags,
 391                 int argc, const char **argv) {
 392
 393         const char *username = NULL;
 394         struct passwd *pw;
 395         int r;
 396         char *buf = NULL;
 397         int lock_fd = -1;
 398         bool create_session = true;
 399         char **controllers = NULL, **reset_controllers = NULL, **c;
 400         char *cgroup_user_tree = NULL;
 401
 402         assert(handle);
 403
 404         /* pam_syslog(handle, LOG_DEBUG, "pam-systemd initializing"); */
 405
 406         /* Make this a NOP on non-systemd systems */
 407         if (sd_booted() <= 0)
 408                 return PAM_SUCCESS;
 409
 410         if (parse_argv(handle,
 411                        argc, argv,
 412                        &create_session, NULL, NULL,
 413                        &controllers, &reset_controllers,
 414                        NULL, NULL) < 0)
 415                 return PAM_SESSION_ERR;
 416
 417         if ((r = get_user_data(handle, &username, &pw)) != PAM_SUCCESS)
 418                 goto finish;
 419
 420         if ((r = cg_get_user_path(&cgroup_user_tree)) < 0) {
 421                 pam_syslog(handle, LOG_ERR, "Failed to determine user cgroup tree: %s", strerror(-r));
 422                 r = PAM_SYSTEM_ERR;
 423                 goto finish;
 424         }
 425
 426         if (safe_mkdir(RUNTIME_DIR "/user", 0755, 0, 0) < 0) {
 427                 pam_syslog(handle, LOG_ERR, "Failed to create runtime directory: %m");
 428                 r = PAM_SYSTEM_ERR;
 429                 goto finish;
 430         }
 431
 432         if ((lock_fd = open_file_and_lock(RUNTIME_DIR "/user/.pam-systemd-lock")) < 0) {
 433                 pam_syslog(handle, LOG_ERR, "Failed to lock runtime directory: %m");
 434                 r = PAM_SYSTEM_ERR;
 435                 goto finish;
 436         }
 437
 438         /* Create /var/run/$USER */
 439         free(buf);
 440         if (asprintf(&buf, RUNTIME_DIR "/user/%s", username) < 0) {
 441                 r = PAM_BUF_ERR;
 442                 goto finish;
 443         }
 444
 445         if (safe_mkdir(buf, 0700, pw->pw_uid, pw->pw_gid) < 0) {
 446                 pam_syslog(handle, LOG_WARNING, "Failed to create runtime directory: %m");
 447                 r = PAM_SYSTEM_ERR;
 448                 goto finish;
 449         } else if ((r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", buf, 0)) != PAM_SUCCESS) {
 450                 pam_syslog(handle, LOG_ERR, "Failed to set runtime dir.");
 451                 goto finish;
 452         }
 453
 454         free(buf);
 455         buf = NULL;
 456
 457         if (create_session) {
 458                 const char *id;
 459
 460                 /* Reuse or create XDG session ID */
 461                 if (!(id = pam_getenv(handle, "XDG_SESSION_ID"))) {
 462                         int mode;
 463
 464                         if (asprintf(&buf, "%llux", (unsigned long long) get_session_id(&mode)) < 0) {
 465                                 r = PAM_BUF_ERR;
 466                                 goto finish;
 467                         }
 468
 469                         /* To avoid id clashes we add the session id
 470                          * source to our session ids. Note that the
 471                          * session id source might change during
 472                          * runtime, because a filesystem became
 473                          * writable or the system reconfigured. */
 474                         buf[strlen(buf)-1] =
 475                                 mode != SESSION_ID_AUDIT ? (char) mode : 0;
 476
 477                         if ((r = pam_misc_setenv(handle, "XDG_SESSION_ID", buf, 0)) != PAM_SUCCESS) {
 478                                 pam_syslog(handle, LOG_ERR, "Failed to set session id.");
 479                                 goto finish;
 480                         }
 481
 482                         if (!(id = pam_getenv(handle, "XDG_SESSION_ID"))) {
 483                                 pam_syslog(handle, LOG_ERR, "Failed to get session id.");
 484                                 r = PAM_SESSION_ERR;
 485                                 goto finish;
 486                         }
 487                 }
 488
 489                 r = asprintf(&buf, "%s/%s/%s", cgroup_user_tree, username, id);
 490         } else
 491                 r = asprintf(&buf, "%s/%s/master", cgroup_user_tree, username);
 492
 493         if (r < 0) {
 494                 r = PAM_BUF_ERR;
 495                 goto finish;
 496         }
 497
 498         pam_syslog(handle, LOG_INFO, "Moving new user session for %s into control group %s.", username, buf);
 499
 500         if ((r = create_user_group(handle, SYSTEMD_CGROUP_CONTROLLER, buf, pw, true, true)) != PAM_SUCCESS)
 501                 goto finish;
 502
 503         /* The additional controllers don't really matter, so we
 504          * ignore the return value */
 505         STRV_FOREACH(c, controllers)
 506                 create_user_group(handle, *c, buf, pw, true, false);
 507
 508         STRV_FOREACH(c, reset_controllers)
 509                 reset_group(handle, *c);
 510
 511         r = PAM_SUCCESS;
 512
 513 finish:
 514         free(buf);
 515
 516         if (lock_fd >= 0)
 517                 close_nointr_nofail(lock_fd);
 518
 519         strv_free(controllers);
 520         strv_free(reset_controllers);
 521
 522         free(cgroup_user_tree);
 523
 524         return r;
 525 }
 526
 527 static int session_remains(pam_handle_t *handle, const char *user_path) {
 528         int r;
 529         bool remains = false;
 530         DIR *d;
 531         char *subgroup;
 532
 533         if ((r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, user_path, &d)) < 0)
 534                 return r;
 535
 536         while ((r = cg_read_subgroup(d, &subgroup)) > 0) {
 537
 538                 remains = !streq(subgroup, "master");
 539                 free(subgroup);
 540
 541                 if (remains)
 542                         break;
 543         }
 544
 545         closedir(d);
 546
 547         if (r < 0)
 548                 return r;
 549
 550         return !!remains;
 551 }
 552
 553 static bool check_user_lists(
 554                 pam_handle_t *handle,
 555                 uid_t uid,
 556                 char **kill_only_users,
 557                 char **kill_exclude_users) {
 558
 559         const char *name = NULL;
 560         char **l;
 561
 562         assert(handle);
 563
 564         if (uid == 0)
 565                 name = "root"; /* Avoid obvious NSS requests, to suppress network traffic */
 566         else {
 567                 struct passwd *pw;
 568
 569                 if ((pw = pam_modutil_getpwuid(handle, uid)))
 570                         name = pw->pw_name;
 571         }
 572
 573         STRV_FOREACH(l, kill_exclude_users) {
 574                 uint32_t id;
 575
 576                 if (safe_atou32(*l, &id) >= 0)
 577                         if ((uid_t) id == uid)
 578                                 return false;
 579
 580                 if (name && streq(name, *l))
 581                         return false;
 582         }
 583
 584         if (strv_isempty(kill_only_users))
 585                 return true;
 586
 587         STRV_FOREACH(l, kill_only_users) {
 588                 uint32_t id;
 589
 590                 if (safe_atou32(*l, &id) >= 0)
 591                         if ((uid_t) id == uid)
 592                                 return true;
 593
 594                 if (name && streq(name, *l))
 595                         return true;
 596         }
 597
 598         return false;
 599 }
 600
 601 _public_ PAM_EXTERN int pam_sm_close_session(
 602                 pam_handle_t *handle,
 603                 int flags,
 604                 int argc, const char **argv) {
 605
 606         const char *username = NULL;
 607         bool kill_session = false;
 608         bool kill_user = false;
 609         int lock_fd = -1, r;
 610         char *session_path = NULL, *nosession_path = NULL, *user_path = NULL;
 611         const char *id;
 612         struct passwd *pw;
 613         const void *created = NULL;
 614         char **controllers = NULL, **c, **kill_only_users = NULL, **kill_exclude_users = NULL;
 615         char *cgroup_user_tree = NULL;
 616
 617         assert(handle);
 618
 619         /* Make this a NOP on non-systemd systems */
 620         if (sd_booted() <= 0)
 621                 return PAM_SUCCESS;
 622
 623         if (parse_argv(handle,
 624                        argc, argv,
 625                        NULL, &kill_session, &kill_user,
 626                        &controllers, NULL,
 627                        &kill_only_users, &kill_exclude_users) < 0)
 628                 return PAM_SESSION_ERR;
 629
 630         if ((r = get_user_data(handle, &username, &pw)) != PAM_SUCCESS)
 631                 goto finish;
 632
 633         if ((r = cg_get_user_path(&cgroup_user_tree)) < 0) {
 634                 pam_syslog(handle, LOG_ERR, "Failed to determine user cgroup tree: %s", strerror(-r));
 635                 r = PAM_SYSTEM_ERR;
 636                 goto finish;
 637         }
 638
 639         if ((lock_fd = open_file_and_lock(RUNTIME_DIR "/user/.pam-systemd-lock")) < 0) {
 640                 pam_syslog(handle, LOG_ERR, "Failed to lock runtime directory: %m");
 641                 r = PAM_SYSTEM_ERR;
 642                 goto finish;
 643         }
 644
 645         /* We are probably still in some session/user dir. Move ourselves out of the way as first step */
 646         if ((r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, cgroup_user_tree, 0)) < 0)
 647                 pam_syslog(handle, LOG_ERR, "Failed to move us away: %s", strerror(-r));
 648
 649         STRV_FOREACH(c, controllers)
 650                 if ((r = cg_attach(*c, cgroup_user_tree, 0)) < 0)
 651                         pam_syslog(handle, LOG_ERR, "Failed to move us away in %s hierarchy: %s", *c, strerror(-r));
 652
 653         if (asprintf(&user_path, "%s/%s", cgroup_user_tree, username) < 0) {
 654                 r = PAM_BUF_ERR;
 655                 goto finish;
 656         }
 657
 658         pam_get_data(handle, "systemd.created", &created);
 659
 660         if ((id = pam_getenv(handle, "XDG_SESSION_ID")) && created) {
 661
 662                 if (asprintf(&session_path, "%s/%s/%s", cgroup_user_tree, username, id) < 0 ||
 663                     asprintf(&nosession_path, "%s/%s/master", cgroup_user_tree, username) < 0) {
 664                         r = PAM_BUF_ERR;
 665                         goto finish;
 666                 }
 667
 668                 if (kill_session && check_user_lists(handle, pw->pw_uid, kill_only_users, kill_exclude_users))  {
 669                         pam_syslog(handle, LOG_INFO, "Killing remaining processes of user session %s of %s.", id, username);
 670
 671                         /* Kill processes in session cgroup, and delete it */
 672                         if ((r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, session_path, true)) < 0)
 673                                 pam_syslog(handle, LOG_ERR, "Failed to kill session cgroup: %s", strerror(-r));
 674                 } else {
 675                         pam_syslog(handle, LOG_INFO, "Moving remaining processes of user session %s of %s into control group %s.", id, username, nosession_path);
 676
 677                         /* Migrate processes from session to user
 678                          * cgroup. First, try to create the user group
 679                          * in case it doesn't exist yet. Also, delete
 680                          * the session group. */
 681                         create_user_group(handle, SYSTEMD_CGROUP_CONTROLLER, nosession_path, pw, false, false);
 682
 683                         if ((r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, session_path, nosession_path, false, true)) < 0)
 684                                 pam_syslog(handle, LOG_ERR, "Failed to migrate session cgroup: %s", strerror(-r));
 685                 }
 686
 687                 STRV_FOREACH(c, controllers) {
 688                         create_user_group(handle, *c, nosession_path, pw, false, false);
 689
 690                         if ((r = cg_migrate_recursive(*c, session_path, nosession_path, false, true)) < 0)
 691                                 pam_syslog(handle, LOG_ERR, "Failed to migrate session cgroup in hierarchy %s: %s", *c, strerror(-r));
 692                 }
 693         }
 694
 695         /* GC user tree */
 696         cg_trim(SYSTEMD_CGROUP_CONTROLLER, user_path, false);
 697
 698         if ((r = session_remains(handle, user_path)) < 0)
 699                 pam_syslog(handle, LOG_ERR, "Failed to determine whether a session remains: %s", strerror(-r));
 700
 701         /* Kill user processes not attached to any session */
 702         if (kill_user && r == 0 && check_user_lists(handle, pw->pw_uid, kill_only_users, kill_exclude_users)) {
 703
 704                 /* Kill user cgroup */
 705                 if ((r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, user_path, true)) < 0)
 706                         pam_syslog(handle, LOG_ERR, "Failed to kill user cgroup: %s", strerror(-r));
 707         } else {
 708
 709                 if ((r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, user_path, true)) < 0)
 710                         pam_syslog(handle, LOG_ERR, "Failed to check user cgroup: %s", strerror(-r));
 711
 712                 /* Remove user cgroup */
 713                 if (r > 0) {
 714                         if ((r = cg_delete(SYSTEMD_CGROUP_CONTROLLER, user_path)) < 0)
 715                                 pam_syslog(handle, LOG_ERR, "Failed to delete user cgroup: %s", strerror(-r));
 716
 717                 /* If we managed to find somebody, don't cleanup the cgroup. */
 718                 } else if (r == 0)
 719                         r = -EBUSY;
 720         }
 721
 722         STRV_FOREACH(c, controllers)
 723                 cg_trim(*c, user_path, true);
 724
 725         if (r >= 0) {
 726                 const char *runtime_dir;
 727
 728                 if ((runtime_dir = pam_getenv(handle, "XDG_RUNTIME_DIR")))
 729                         if ((r = rm_rf(runtime_dir, false, true)) < 0)
 730                                 pam_syslog(handle, LOG_ERR, "Failed to remove runtime directory: %s", strerror(-r));
 731         }
 732
 733         /* pam_syslog(handle, LOG_DEBUG, "pam-systemd done"); */
 734
 735         r = PAM_SUCCESS;
 736
 737 finish:
 738         if (lock_fd >= 0)
 739                 close_nointr_nofail(lock_fd);
 740
 741         free(session_path);
 742         free(nosession_path);
 743         free(user_path);
 744
 745         strv_free(controllers);
 746         strv_free(kill_exclude_users);
 747         strv_free(kill_only_users);
 748
 749         free(cgroup_user_tree);
 750
 751         return r;
 752 }