src/login/logind-inhibit.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <string.h>
   6 #include <unistd.h>
   7
   8 #include "alloc-util.h"
   9 #include "escape.h"
  10 #include "fd-util.h"
  11 #include "fileio.h"
  12 #include "format-util.h"
  13 #include "logind-inhibit.h"
  14 #include "mkdir.h"
  15 #include "parse-util.h"
  16 #include "string-table.h"
  17 #include "string-util.h"
  18 #include "user-util.h"
  19 #include "util.h"
  20
  21 Inhibitor* inhibitor_new(Manager *m, const char* id) {
  22         Inhibitor *i;
  23
  24         assert(m);
  25
  26         i = new0(Inhibitor, 1);
  27         if (!i)
  28                 return NULL;
  29
  30         i->state_file = strappend("/run/systemd/inhibit/", id);
  31         if (!i->state_file)
  32                 return mfree(i);
  33
  34         i->id = basename(i->state_file);
  35
  36         if (hashmap_put(m->inhibitors, i->id, i) < 0) {
  37                 free(i->state_file);
  38                 return mfree(i);
  39         }
  40
  41         i->manager = m;
  42         i->fifo_fd = -1;
  43
  44         return i;
  45 }
  46
  47 void inhibitor_free(Inhibitor *i) {
  48         assert(i);
  49
  50         hashmap_remove(i->manager->inhibitors, i->id);
  51
  52         inhibitor_remove_fifo(i);
  53
  54         free(i->who);
  55         free(i->why);
  56
  57         if (i->state_file) {
  58                 unlink(i->state_file);
  59                 free(i->state_file);
  60         }
  61
  62         free(i);
  63 }
  64
  65 int inhibitor_save(Inhibitor *i) {
  66         _cleanup_free_ char *temp_path = NULL;
  67         _cleanup_fclose_ FILE *f = NULL;
  68         int r;
  69
  70         assert(i);
  71
  72         r = mkdir_safe_label("/run/systemd/inhibit", 0755, 0, 0, MKDIR_WARN_MODE);
  73         if (r < 0)
  74                 goto fail;
  75
  76         r = fopen_temporary(i->state_file, &f, &temp_path);
  77         if (r < 0)
  78                 goto fail;
  79
  80         fchmod(fileno(f), 0644);
  81
  82         fprintf(f,
  83                 "# This is private data. Do not parse.\n"
  84                 "WHAT=%s\n"
  85                 "MODE=%s\n"
  86                 "UID="UID_FMT"\n"
  87                 "PID="PID_FMT"\n",
  88                 inhibit_what_to_string(i->what),
  89                 inhibit_mode_to_string(i->mode),
  90                 i->uid,
  91                 i->pid);
  92
  93         if (i->who) {
  94                 _cleanup_free_ char *cc = NULL;
  95
  96                 cc = cescape(i->who);
  97                 if (!cc) {
  98                         r = -ENOMEM;
  99                         goto fail;
 100                 }
 101
 102                 fprintf(f, "WHO=%s\n", cc);
 103         }
 104
 105         if (i->why) {
 106                 _cleanup_free_ char *cc = NULL;
 107
 108                 cc = cescape(i->why);
 109                 if (!cc) {
 110                         r = -ENOMEM;
 111                         goto fail;
 112                 }
 113
 114                 fprintf(f, "WHY=%s\n", cc);
 115         }
 116
 117         if (i->fifo_path)
 118                 fprintf(f, "FIFO=%s\n", i->fifo_path);
 119
 120         r = fflush_and_check(f);
 121         if (r < 0)
 122                 goto fail;
 123
 124         if (rename(temp_path, i->state_file) < 0) {
 125                 r = -errno;
 126                 goto fail;
 127         }
 128
 129         return 0;
 130
 131 fail:
 132         (void) unlink(i->state_file);
 133
 134         if (temp_path)
 135                 (void) unlink(temp_path);
 136
 137         return log_error_errno(r, "Failed to save inhibit data %s: %m", i->state_file);
 138 }
 139
 140 int inhibitor_start(Inhibitor *i) {
 141         assert(i);
 142
 143         if (i->started)
 144                 return 0;
 145
 146         dual_timestamp_get(&i->since);
 147
 148         log_debug("Inhibitor %s (%s) pid="PID_FMT" uid="UID_FMT" mode=%s started.",
 149                   strna(i->who), strna(i->why),
 150                   i->pid, i->uid,
 151                   inhibit_mode_to_string(i->mode));
 152
 153         inhibitor_save(i);
 154
 155         i->started = true;
 156
 157         manager_send_changed(i->manager, i->mode == INHIBIT_BLOCK ? "BlockInhibited" : "DelayInhibited", NULL);
 158
 159         return 0;
 160 }
 161
 162 int inhibitor_stop(Inhibitor *i) {
 163         assert(i);
 164
 165         if (i->started)
 166                 log_debug("Inhibitor %s (%s) pid="PID_FMT" uid="UID_FMT" mode=%s stopped.",
 167                           strna(i->who), strna(i->why),
 168                           i->pid, i->uid,
 169                           inhibit_mode_to_string(i->mode));
 170
 171         if (i->state_file)
 172                 unlink(i->state_file);
 173
 174         i->started = false;
 175
 176         manager_send_changed(i->manager, i->mode == INHIBIT_BLOCK ? "BlockInhibited" : "DelayInhibited", NULL);
 177
 178         return 0;
 179 }
 180
 181 int inhibitor_load(Inhibitor *i) {
 182
 183         _cleanup_free_ char
 184                 *what = NULL,
 185                 *uid = NULL,
 186                 *pid = NULL,
 187                 *who = NULL,
 188                 *why = NULL,
 189                 *mode = NULL;
 190
 191         InhibitWhat w;
 192         InhibitMode mm;
 193         char *cc;
 194         int r;
 195
 196         r = parse_env_file(NULL, i->state_file, NEWLINE,
 197                            "WHAT", &what,
 198                            "UID", &uid,
 199                            "PID", &pid,
 200                            "WHO", &who,
 201                            "WHY", &why,
 202                            "MODE", &mode,
 203                            "FIFO", &i->fifo_path,
 204                            NULL);
 205         if (r < 0)
 206                 return r;
 207
 208         w = what ? inhibit_what_from_string(what) : 0;
 209         if (w >= 0)
 210                 i->what = w;
 211
 212         mm = mode ? inhibit_mode_from_string(mode) : INHIBIT_BLOCK;
 213         if  (mm >= 0)
 214                 i->mode = mm;
 215
 216         if (uid) {
 217                 r = parse_uid(uid, &i->uid);
 218                 if (r < 0)
 219                         return r;
 220         }
 221
 222         if (pid) {
 223                 r = parse_pid(pid, &i->pid);
 224                 if (r < 0)
 225                         return r;
 226         }
 227
 228         if (who) {
 229                 r = cunescape(who, 0, &cc);
 230                 if (r < 0)
 231                         return r;
 232
 233                 free(i->who);
 234                 i->who = cc;
 235         }
 236
 237         if (why) {
 238                 r = cunescape(why, 0, &cc);
 239                 if (r < 0)
 240                         return r;
 241
 242                 free(i->why);
 243                 i->why = cc;
 244         }
 245
 246         if (i->fifo_path) {
 247                 int fd;
 248
 249                 fd = inhibitor_create_fifo(i);
 250                 safe_close(fd);
 251         }
 252
 253         return 0;
 254 }
 255
 256 static int inhibitor_dispatch_fifo(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 257         Inhibitor *i = userdata;
 258
 259         assert(s);
 260         assert(fd == i->fifo_fd);
 261         assert(i);
 262
 263         inhibitor_stop(i);
 264         inhibitor_free(i);
 265
 266         return 0;
 267 }
 268
 269 int inhibitor_create_fifo(Inhibitor *i) {
 270         int r;
 271
 272         assert(i);
 273
 274         /* Create FIFO */
 275         if (!i->fifo_path) {
 276                 r = mkdir_safe_label("/run/systemd/inhibit", 0755, 0, 0, MKDIR_WARN_MODE);
 277                 if (r < 0)
 278                         return r;
 279
 280                 i->fifo_path = strjoin("/run/systemd/inhibit/", i->id, ".ref");
 281                 if (!i->fifo_path)
 282                         return -ENOMEM;
 283
 284                 if (mkfifo(i->fifo_path, 0600) < 0 && errno != EEXIST)
 285                         return -errno;
 286         }
 287
 288         /* Open reading side */
 289         if (i->fifo_fd < 0) {
 290                 i->fifo_fd = open(i->fifo_path, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
 291                 if (i->fifo_fd < 0)
 292                         return -errno;
 293         }
 294
 295         if (!i->event_source) {
 296                 r = sd_event_add_io(i->manager->event, &i->event_source, i->fifo_fd, 0, inhibitor_dispatch_fifo, i);
 297                 if (r < 0)
 298                         return r;
 299
 300                 r = sd_event_source_set_priority(i->event_source, SD_EVENT_PRIORITY_IDLE-10);
 301                 if (r < 0)
 302                         return r;
 303         }
 304
 305         /* Open writing side */
 306         r = open(i->fifo_path, O_WRONLY|O_CLOEXEC|O_NONBLOCK);
 307         if (r < 0)
 308                 return -errno;
 309
 310         return r;
 311 }
 312
 313 void inhibitor_remove_fifo(Inhibitor *i) {
 314         assert(i);
 315
 316         i->event_source = sd_event_source_unref(i->event_source);
 317         i->fifo_fd = safe_close(i->fifo_fd);
 318
 319         if (i->fifo_path) {
 320                 unlink(i->fifo_path);
 321                 i->fifo_path = mfree(i->fifo_path);
 322         }
 323 }
 324
 325 InhibitWhat manager_inhibit_what(Manager *m, InhibitMode mm) {
 326         Inhibitor *i;
 327         Iterator j;
 328         InhibitWhat what = 0;
 329
 330         assert(m);
 331
 332         HASHMAP_FOREACH(i, m->inhibitors, j)
 333                 if (i->mode == mm && i->started)
 334                         what |= i->what;
 335
 336         return what;
 337 }
 338
 339 static int pid_is_active(Manager *m, pid_t pid) {
 340         Session *s;
 341         int r;
 342
 343         /* Get client session.  This is not what you are looking for these days.
 344          * FIXME #6852 */
 345         r = manager_get_session_by_pid(m, pid, &s);
 346         if (r < 0)
 347                 return r;
 348
 349         /* If there's no session assigned to it, then it's globally
 350          * active on all ttys */
 351         if (r == 0)
 352                 return 1;
 353
 354         return session_is_active(s);
 355 }
 356
 357 bool manager_is_inhibited(
 358                 Manager *m,
 359                 InhibitWhat w,
 360                 InhibitMode mm,
 361                 dual_timestamp *since,
 362                 bool ignore_inactive,
 363                 bool ignore_uid,
 364                 uid_t uid,
 365                 Inhibitor **offending) {
 366
 367         Inhibitor *i;
 368         Iterator j;
 369         struct dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 370         bool inhibited = false;
 371
 372         assert(m);
 373         assert(w > 0 && w < _INHIBIT_WHAT_MAX);
 374
 375         HASHMAP_FOREACH(i, m->inhibitors, j) {
 376                 if (!i->started)
 377                         continue;
 378
 379                 if (!(i->what & w))
 380                         continue;
 381
 382                 if (i->mode != mm)
 383                         continue;
 384
 385                 if (ignore_inactive && pid_is_active(m, i->pid) <= 0)
 386                         continue;
 387
 388                 if (ignore_uid && i->uid == uid)
 389                         continue;
 390
 391                 if (!inhibited ||
 392                     i->since.monotonic < ts.monotonic)
 393                         ts = i->since;
 394
 395                 inhibited = true;
 396
 397                 if (offending)
 398                         *offending = i;
 399         }
 400
 401         if (since)
 402                 *since = ts;
 403
 404         return inhibited;
 405 }
 406
 407 const char *inhibit_what_to_string(InhibitWhat w) {
 408         static thread_local char buffer[97];
 409         char *p;
 410
 411         if (w < 0 || w >= _INHIBIT_WHAT_MAX)
 412                 return NULL;
 413
 414         p = buffer;
 415         if (w & INHIBIT_SHUTDOWN)
 416                 p = stpcpy(p, "shutdown:");
 417         if (w & INHIBIT_SLEEP)
 418                 p = stpcpy(p, "sleep:");
 419         if (w & INHIBIT_IDLE)
 420                 p = stpcpy(p, "idle:");
 421         if (w & INHIBIT_HANDLE_POWER_KEY)
 422                 p = stpcpy(p, "handle-power-key:");
 423         if (w & INHIBIT_HANDLE_SUSPEND_KEY)
 424                 p = stpcpy(p, "handle-suspend-key:");
 425         if (w & INHIBIT_HANDLE_HIBERNATE_KEY)
 426                 p = stpcpy(p, "handle-hibernate-key:");
 427         if (w & INHIBIT_HANDLE_LID_SWITCH)
 428                 p = stpcpy(p, "handle-lid-switch:");
 429
 430         if (p > buffer)
 431                 *(p-1) = 0;
 432         else
 433                 *p = 0;
 434
 435         return buffer;
 436 }
 437
 438 InhibitWhat inhibit_what_from_string(const char *s) {
 439         InhibitWhat what = 0;
 440         const char *word, *state;
 441         size_t l;
 442
 443         FOREACH_WORD_SEPARATOR(word, l, s, ":", state) {
 444                 if (l == 8 && strneq(word, "shutdown", l))
 445                         what |= INHIBIT_SHUTDOWN;
 446                 else if (l == 5 && strneq(word, "sleep", l))
 447                         what |= INHIBIT_SLEEP;
 448                 else if (l == 4 && strneq(word, "idle", l))
 449                         what |= INHIBIT_IDLE;
 450                 else if (l == 16 && strneq(word, "handle-power-key", l))
 451                         what |= INHIBIT_HANDLE_POWER_KEY;
 452                 else if (l == 18 && strneq(word, "handle-suspend-key", l))
 453                         what |= INHIBIT_HANDLE_SUSPEND_KEY;
 454                 else if (l == 20 && strneq(word, "handle-hibernate-key", l))
 455                         what |= INHIBIT_HANDLE_HIBERNATE_KEY;
 456                 else if (l == 17 && strneq(word, "handle-lid-switch", l))
 457                         what |= INHIBIT_HANDLE_LID_SWITCH;
 458                 else
 459                         return _INHIBIT_WHAT_INVALID;
 460         }
 461
 462         return what;
 463 }
 464
 465 static const char* const inhibit_mode_table[_INHIBIT_MODE_MAX] = {
 466         [INHIBIT_BLOCK] = "block",
 467         [INHIBIT_DELAY] = "delay"
 468 };
 469
 470 DEFINE_STRING_TABLE_LOOKUP(inhibit_mode, InhibitMode);