src/login/logind-inhibit.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright 2012 Lennart Poettering
   4 ***/
   5
   6 #include <errno.h>
   7 #include <fcntl.h>
   8 #include <string.h>
   9 #include <unistd.h>
  10
  11 #include "alloc-util.h"
  12 #include "escape.h"
  13 #include "fd-util.h"
  14 #include "fileio.h"
  15 #include "format-util.h"
  16 #include "logind-inhibit.h"
  17 #include "mkdir.h"
  18 #include "parse-util.h"
  19 #include "string-table.h"
  20 #include "string-util.h"
  21 #include "user-util.h"
  22 #include "util.h"
  23
  24 Inhibitor* inhibitor_new(Manager *m, const char* id) {
  25         Inhibitor *i;
  26
  27         assert(m);
  28
  29         i = new0(Inhibitor, 1);
  30         if (!i)
  31                 return NULL;
  32
  33         i->state_file = strappend("/run/systemd/inhibit/", id);
  34         if (!i->state_file)
  35                 return mfree(i);
  36
  37         i->id = basename(i->state_file);
  38
  39         if (hashmap_put(m->inhibitors, i->id, i) < 0) {
  40                 free(i->state_file);
  41                 return mfree(i);
  42         }
  43
  44         i->manager = m;
  45         i->fifo_fd = -1;
  46
  47         return i;
  48 }
  49
  50 void inhibitor_free(Inhibitor *i) {
  51         assert(i);
  52
  53         hashmap_remove(i->manager->inhibitors, i->id);
  54
  55         inhibitor_remove_fifo(i);
  56
  57         free(i->who);
  58         free(i->why);
  59
  60         if (i->state_file) {
  61                 unlink(i->state_file);
  62                 free(i->state_file);
  63         }
  64
  65         free(i);
  66 }
  67
  68 int inhibitor_save(Inhibitor *i) {
  69         _cleanup_free_ char *temp_path = NULL;
  70         _cleanup_fclose_ FILE *f = NULL;
  71         int r;
  72
  73         assert(i);
  74
  75         r = mkdir_safe_label("/run/systemd/inhibit", 0755, 0, 0, MKDIR_WARN_MODE);
  76         if (r < 0)
  77                 goto fail;
  78
  79         r = fopen_temporary(i->state_file, &f, &temp_path);
  80         if (r < 0)
  81                 goto fail;
  82
  83         fchmod(fileno(f), 0644);
  84
  85         fprintf(f,
  86                 "# This is private data. Do not parse.\n"
  87                 "WHAT=%s\n"
  88                 "MODE=%s\n"
  89                 "UID="UID_FMT"\n"
  90                 "PID="PID_FMT"\n",
  91                 inhibit_what_to_string(i->what),
  92                 inhibit_mode_to_string(i->mode),
  93                 i->uid,
  94                 i->pid);
  95
  96         if (i->who) {
  97                 _cleanup_free_ char *cc = NULL;
  98
  99                 cc = cescape(i->who);
 100                 if (!cc) {
 101                         r = -ENOMEM;
 102                         goto fail;
 103                 }
 104
 105                 fprintf(f, "WHO=%s\n", cc);
 106         }
 107
 108         if (i->why) {
 109                 _cleanup_free_ char *cc = NULL;
 110
 111                 cc = cescape(i->why);
 112                 if (!cc) {
 113                         r = -ENOMEM;
 114                         goto fail;
 115                 }
 116
 117                 fprintf(f, "WHY=%s\n", cc);
 118         }
 119
 120         if (i->fifo_path)
 121                 fprintf(f, "FIFO=%s\n", i->fifo_path);
 122
 123         r = fflush_and_check(f);
 124         if (r < 0)
 125                 goto fail;
 126
 127         if (rename(temp_path, i->state_file) < 0) {
 128                 r = -errno;
 129                 goto fail;
 130         }
 131
 132         return 0;
 133
 134 fail:
 135         (void) unlink(i->state_file);
 136
 137         if (temp_path)
 138                 (void) unlink(temp_path);
 139
 140         return log_error_errno(r, "Failed to save inhibit data %s: %m", i->state_file);
 141 }
 142
 143 int inhibitor_start(Inhibitor *i) {
 144         assert(i);
 145
 146         if (i->started)
 147                 return 0;
 148
 149         dual_timestamp_get(&i->since);
 150
 151         log_debug("Inhibitor %s (%s) pid="PID_FMT" uid="UID_FMT" mode=%s started.",
 152                   strna(i->who), strna(i->why),
 153                   i->pid, i->uid,
 154                   inhibit_mode_to_string(i->mode));
 155
 156         inhibitor_save(i);
 157
 158         i->started = true;
 159
 160         manager_send_changed(i->manager, i->mode == INHIBIT_BLOCK ? "BlockInhibited" : "DelayInhibited", NULL);
 161
 162         return 0;
 163 }
 164
 165 int inhibitor_stop(Inhibitor *i) {
 166         assert(i);
 167
 168         if (i->started)
 169                 log_debug("Inhibitor %s (%s) pid="PID_FMT" uid="UID_FMT" mode=%s stopped.",
 170                           strna(i->who), strna(i->why),
 171                           i->pid, i->uid,
 172                           inhibit_mode_to_string(i->mode));
 173
 174         if (i->state_file)
 175                 unlink(i->state_file);
 176
 177         i->started = false;
 178
 179         manager_send_changed(i->manager, i->mode == INHIBIT_BLOCK ? "BlockInhibited" : "DelayInhibited", NULL);
 180
 181         return 0;
 182 }
 183
 184 int inhibitor_load(Inhibitor *i) {
 185
 186         _cleanup_free_ char
 187                 *what = NULL,
 188                 *uid = NULL,
 189                 *pid = NULL,
 190                 *who = NULL,
 191                 *why = NULL,
 192                 *mode = NULL;
 193
 194         InhibitWhat w;
 195         InhibitMode mm;
 196         char *cc;
 197         int r;
 198
 199         r = parse_env_file(NULL, i->state_file, NEWLINE,
 200                            "WHAT", &what,
 201                            "UID", &uid,
 202                            "PID", &pid,
 203                            "WHO", &who,
 204                            "WHY", &why,
 205                            "MODE", &mode,
 206                            "FIFO", &i->fifo_path,
 207                            NULL);
 208         if (r < 0)
 209                 return r;
 210
 211         w = what ? inhibit_what_from_string(what) : 0;
 212         if (w >= 0)
 213                 i->what = w;
 214
 215         mm = mode ? inhibit_mode_from_string(mode) : INHIBIT_BLOCK;
 216         if  (mm >= 0)
 217                 i->mode = mm;
 218
 219         if (uid) {
 220                 r = parse_uid(uid, &i->uid);
 221                 if (r < 0)
 222                         return r;
 223         }
 224
 225         if (pid) {
 226                 r = parse_pid(pid, &i->pid);
 227                 if (r < 0)
 228                         return r;
 229         }
 230
 231         if (who) {
 232                 r = cunescape(who, 0, &cc);
 233                 if (r < 0)
 234                         return r;
 235
 236                 free(i->who);
 237                 i->who = cc;
 238         }
 239
 240         if (why) {
 241                 r = cunescape(why, 0, &cc);
 242                 if (r < 0)
 243                         return r;
 244
 245                 free(i->why);
 246                 i->why = cc;
 247         }
 248
 249         if (i->fifo_path) {
 250                 int fd;
 251
 252                 fd = inhibitor_create_fifo(i);
 253                 safe_close(fd);
 254         }
 255
 256         return 0;
 257 }
 258
 259 static int inhibitor_dispatch_fifo(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 260         Inhibitor *i = userdata;
 261
 262         assert(s);
 263         assert(fd == i->fifo_fd);
 264         assert(i);
 265
 266         inhibitor_stop(i);
 267         inhibitor_free(i);
 268
 269         return 0;
 270 }
 271
 272 int inhibitor_create_fifo(Inhibitor *i) {
 273         int r;
 274
 275         assert(i);
 276
 277         /* Create FIFO */
 278         if (!i->fifo_path) {
 279                 r = mkdir_safe_label("/run/systemd/inhibit", 0755, 0, 0, MKDIR_WARN_MODE);
 280                 if (r < 0)
 281                         return r;
 282
 283                 i->fifo_path = strjoin("/run/systemd/inhibit/", i->id, ".ref");
 284                 if (!i->fifo_path)
 285                         return -ENOMEM;
 286
 287                 if (mkfifo(i->fifo_path, 0600) < 0 && errno != EEXIST)
 288                         return -errno;
 289         }
 290
 291         /* Open reading side */
 292         if (i->fifo_fd < 0) {
 293                 i->fifo_fd = open(i->fifo_path, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
 294                 if (i->fifo_fd < 0)
 295                         return -errno;
 296         }
 297
 298         if (!i->event_source) {
 299                 r = sd_event_add_io(i->manager->event, &i->event_source, i->fifo_fd, 0, inhibitor_dispatch_fifo, i);
 300                 if (r < 0)
 301                         return r;
 302
 303                 r = sd_event_source_set_priority(i->event_source, SD_EVENT_PRIORITY_IDLE-10);
 304                 if (r < 0)
 305                         return r;
 306         }
 307
 308         /* Open writing side */
 309         r = open(i->fifo_path, O_WRONLY|O_CLOEXEC|O_NONBLOCK);
 310         if (r < 0)
 311                 return -errno;
 312
 313         return r;
 314 }
 315
 316 void inhibitor_remove_fifo(Inhibitor *i) {
 317         assert(i);
 318
 319         i->event_source = sd_event_source_unref(i->event_source);
 320         i->fifo_fd = safe_close(i->fifo_fd);
 321
 322         if (i->fifo_path) {
 323                 unlink(i->fifo_path);
 324                 i->fifo_path = mfree(i->fifo_path);
 325         }
 326 }
 327
 328 InhibitWhat manager_inhibit_what(Manager *m, InhibitMode mm) {
 329         Inhibitor *i;
 330         Iterator j;
 331         InhibitWhat what = 0;
 332
 333         assert(m);
 334
 335         HASHMAP_FOREACH(i, m->inhibitors, j)
 336                 if (i->mode == mm && i->started)
 337                         what |= i->what;
 338
 339         return what;
 340 }
 341
 342 static int pid_is_active(Manager *m, pid_t pid) {
 343         Session *s;
 344         int r;
 345
 346         /* Get client session.  This is not what you are looking for these days.
 347          * FIXME #6852 */
 348         r = manager_get_session_by_pid(m, pid, &s);
 349         if (r < 0)
 350                 return r;
 351
 352         /* If there's no session assigned to it, then it's globally
 353          * active on all ttys */
 354         if (r == 0)
 355                 return 1;
 356
 357         return session_is_active(s);
 358 }
 359
 360 bool manager_is_inhibited(
 361                 Manager *m,
 362                 InhibitWhat w,
 363                 InhibitMode mm,
 364                 dual_timestamp *since,
 365                 bool ignore_inactive,
 366                 bool ignore_uid,
 367                 uid_t uid,
 368                 Inhibitor **offending) {
 369
 370         Inhibitor *i;
 371         Iterator j;
 372         struct dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 373         bool inhibited = false;
 374
 375         assert(m);
 376         assert(w > 0 && w < _INHIBIT_WHAT_MAX);
 377
 378         HASHMAP_FOREACH(i, m->inhibitors, j) {
 379                 if (!i->started)
 380                         continue;
 381
 382                 if (!(i->what & w))
 383                         continue;
 384
 385                 if (i->mode != mm)
 386                         continue;
 387
 388                 if (ignore_inactive && pid_is_active(m, i->pid) <= 0)
 389                         continue;
 390
 391                 if (ignore_uid && i->uid == uid)
 392                         continue;
 393
 394                 if (!inhibited ||
 395                     i->since.monotonic < ts.monotonic)
 396                         ts = i->since;
 397
 398                 inhibited = true;
 399
 400                 if (offending)
 401                         *offending = i;
 402         }
 403
 404         if (since)
 405                 *since = ts;
 406
 407         return inhibited;
 408 }
 409
 410 const char *inhibit_what_to_string(InhibitWhat w) {
 411         static thread_local char buffer[97];
 412         char *p;
 413
 414         if (w < 0 || w >= _INHIBIT_WHAT_MAX)
 415                 return NULL;
 416
 417         p = buffer;
 418         if (w & INHIBIT_SHUTDOWN)
 419                 p = stpcpy(p, "shutdown:");
 420         if (w & INHIBIT_SLEEP)
 421                 p = stpcpy(p, "sleep:");
 422         if (w & INHIBIT_IDLE)
 423                 p = stpcpy(p, "idle:");
 424         if (w & INHIBIT_HANDLE_POWER_KEY)
 425                 p = stpcpy(p, "handle-power-key:");
 426         if (w & INHIBIT_HANDLE_SUSPEND_KEY)
 427                 p = stpcpy(p, "handle-suspend-key:");
 428         if (w & INHIBIT_HANDLE_HIBERNATE_KEY)
 429                 p = stpcpy(p, "handle-hibernate-key:");
 430         if (w & INHIBIT_HANDLE_LID_SWITCH)
 431                 p = stpcpy(p, "handle-lid-switch:");
 432
 433         if (p > buffer)
 434                 *(p-1) = 0;
 435         else
 436                 *p = 0;
 437
 438         return buffer;
 439 }
 440
 441 InhibitWhat inhibit_what_from_string(const char *s) {
 442         InhibitWhat what = 0;
 443         const char *word, *state;
 444         size_t l;
 445
 446         FOREACH_WORD_SEPARATOR(word, l, s, ":", state) {
 447                 if (l == 8 && strneq(word, "shutdown", l))
 448                         what |= INHIBIT_SHUTDOWN;
 449                 else if (l == 5 && strneq(word, "sleep", l))
 450                         what |= INHIBIT_SLEEP;
 451                 else if (l == 4 && strneq(word, "idle", l))
 452                         what |= INHIBIT_IDLE;
 453                 else if (l == 16 && strneq(word, "handle-power-key", l))
 454                         what |= INHIBIT_HANDLE_POWER_KEY;
 455                 else if (l == 18 && strneq(word, "handle-suspend-key", l))
 456                         what |= INHIBIT_HANDLE_SUSPEND_KEY;
 457                 else if (l == 20 && strneq(word, "handle-hibernate-key", l))
 458                         what |= INHIBIT_HANDLE_HIBERNATE_KEY;
 459                 else if (l == 17 && strneq(word, "handle-lid-switch", l))
 460                         what |= INHIBIT_HANDLE_LID_SWITCH;
 461                 else
 462                         return _INHIBIT_WHAT_INVALID;
 463         }
 464
 465         return what;
 466 }
 467
 468 static const char* const inhibit_mode_table[_INHIBIT_MODE_MAX] = {
 469         [INHIBIT_BLOCK] = "block",
 470         [INHIBIT_DELAY] = "delay"
 471 };
 472
 473 DEFINE_STRING_TABLE_LOOKUP(inhibit_mode, InhibitMode);