src/login/logind-inhibit.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2012 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24
  25 #include "alloc-util.h"
  26 #include "escape.h"
  27 #include "fd-util.h"
  28 #include "fileio.h"
  29 #include "format-util.h"
  30 #include "logind-inhibit.h"
  31 #include "mkdir.h"
  32 #include "parse-util.h"
  33 #include "string-table.h"
  34 #include "string-util.h"
  35 #include "user-util.h"
  36 #include "util.h"
  37
  38 Inhibitor* inhibitor_new(Manager *m, const char* id) {
  39         Inhibitor *i;
  40
  41         assert(m);
  42
  43         i = new0(Inhibitor, 1);
  44         if (!i)
  45                 return NULL;
  46
  47         i->state_file = strappend("/run/systemd/inhibit/", id);
  48         if (!i->state_file)
  49                 return mfree(i);
  50
  51         i->id = basename(i->state_file);
  52
  53         if (hashmap_put(m->inhibitors, i->id, i) < 0) {
  54                 free(i->state_file);
  55                 return mfree(i);
  56         }
  57
  58         i->manager = m;
  59         i->fifo_fd = -1;
  60
  61         return i;
  62 }
  63
  64 void inhibitor_free(Inhibitor *i) {
  65         assert(i);
  66
  67         hashmap_remove(i->manager->inhibitors, i->id);
  68
  69         inhibitor_remove_fifo(i);
  70
  71         free(i->who);
  72         free(i->why);
  73
  74         if (i->state_file) {
  75                 unlink(i->state_file);
  76                 free(i->state_file);
  77         }
  78
  79         free(i);
  80 }
  81
  82 int inhibitor_save(Inhibitor *i) {
  83         _cleanup_free_ char *temp_path = NULL;
  84         _cleanup_fclose_ FILE *f = NULL;
  85         int r;
  86
  87         assert(i);
  88
  89         r = mkdir_safe_label("/run/systemd/inhibit", 0755, 0, 0);
  90         if (r < 0)
  91                 goto fail;
  92
  93         r = fopen_temporary(i->state_file, &f, &temp_path);
  94         if (r < 0)
  95                 goto fail;
  96
  97         fchmod(fileno(f), 0644);
  98
  99         fprintf(f,
 100                 "# This is private data. Do not parse.\n"
 101                 "WHAT=%s\n"
 102                 "MODE=%s\n"
 103                 "UID="UID_FMT"\n"
 104                 "PID="PID_FMT"\n",
 105                 inhibit_what_to_string(i->what),
 106                 inhibit_mode_to_string(i->mode),
 107                 i->uid,
 108                 i->pid);
 109
 110         if (i->who) {
 111                 _cleanup_free_ char *cc = NULL;
 112
 113                 cc = cescape(i->who);
 114                 if (!cc) {
 115                         r = -ENOMEM;
 116                         goto fail;
 117                 }
 118
 119                 fprintf(f, "WHO=%s\n", cc);
 120         }
 121
 122         if (i->why) {
 123                 _cleanup_free_ char *cc = NULL;
 124
 125                 cc = cescape(i->why);
 126                 if (!cc) {
 127                         r = -ENOMEM;
 128                         goto fail;
 129                 }
 130
 131                 fprintf(f, "WHY=%s\n", cc);
 132         }
 133
 134         if (i->fifo_path)
 135                 fprintf(f, "FIFO=%s\n", i->fifo_path);
 136
 137         r = fflush_and_check(f);
 138         if (r < 0)
 139                 goto fail;
 140
 141         if (rename(temp_path, i->state_file) < 0) {
 142                 r = -errno;
 143                 goto fail;
 144         }
 145
 146         return 0;
 147
 148 fail:
 149         (void) unlink(i->state_file);
 150
 151         if (temp_path)
 152                 (void) unlink(temp_path);
 153
 154         return log_error_errno(r, "Failed to save inhibit data %s: %m", i->state_file);
 155 }
 156
 157 int inhibitor_start(Inhibitor *i) {
 158         assert(i);
 159
 160         if (i->started)
 161                 return 0;
 162
 163         dual_timestamp_get(&i->since);
 164
 165         log_debug("Inhibitor %s (%s) pid="PID_FMT" uid="UID_FMT" mode=%s started.",
 166                   strna(i->who), strna(i->why),
 167                   i->pid, i->uid,
 168                   inhibit_mode_to_string(i->mode));
 169
 170         inhibitor_save(i);
 171
 172         i->started = true;
 173
 174         manager_send_changed(i->manager, i->mode == INHIBIT_BLOCK ? "BlockInhibited" : "DelayInhibited", NULL);
 175
 176         return 0;
 177 }
 178
 179 int inhibitor_stop(Inhibitor *i) {
 180         assert(i);
 181
 182         if (i->started)
 183                 log_debug("Inhibitor %s (%s) pid="PID_FMT" uid="UID_FMT" mode=%s stopped.",
 184                           strna(i->who), strna(i->why),
 185                           i->pid, i->uid,
 186                           inhibit_mode_to_string(i->mode));
 187
 188         if (i->state_file)
 189                 unlink(i->state_file);
 190
 191         i->started = false;
 192
 193         manager_send_changed(i->manager, i->mode == INHIBIT_BLOCK ? "BlockInhibited" : "DelayInhibited", NULL);
 194
 195         return 0;
 196 }
 197
 198 int inhibitor_load(Inhibitor *i) {
 199
 200         _cleanup_free_ char
 201                 *what = NULL,
 202                 *uid = NULL,
 203                 *pid = NULL,
 204                 *who = NULL,
 205                 *why = NULL,
 206                 *mode = NULL;
 207
 208         InhibitWhat w;
 209         InhibitMode mm;
 210         char *cc;
 211         int r;
 212
 213         r = parse_env_file(i->state_file, NEWLINE,
 214                            "WHAT", &what,
 215                            "UID", &uid,
 216                            "PID", &pid,
 217                            "WHO", &who,
 218                            "WHY", &why,
 219                            "MODE", &mode,
 220                            "FIFO", &i->fifo_path,
 221                            NULL);
 222         if (r < 0)
 223                 return r;
 224
 225         w = what ? inhibit_what_from_string(what) : 0;
 226         if (w >= 0)
 227                 i->what = w;
 228
 229         mm = mode ? inhibit_mode_from_string(mode) : INHIBIT_BLOCK;
 230         if  (mm >= 0)
 231                 i->mode = mm;
 232
 233         if (uid) {
 234                 r = parse_uid(uid, &i->uid);
 235                 if (r < 0)
 236                         return r;
 237         }
 238
 239         if (pid) {
 240                 r = parse_pid(pid, &i->pid);
 241                 if (r < 0)
 242                         return r;
 243         }
 244
 245         if (who) {
 246                 r = cunescape(who, 0, &cc);
 247                 if (r < 0)
 248                         return r;
 249
 250                 free(i->who);
 251                 i->who = cc;
 252         }
 253
 254         if (why) {
 255                 r = cunescape(why, 0, &cc);
 256                 if (r < 0)
 257                         return r;
 258
 259                 free(i->why);
 260                 i->why = cc;
 261         }
 262
 263         if (i->fifo_path) {
 264                 int fd;
 265
 266                 fd = inhibitor_create_fifo(i);
 267                 safe_close(fd);
 268         }
 269
 270         return 0;
 271 }
 272
 273 static int inhibitor_dispatch_fifo(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 274         Inhibitor *i = userdata;
 275
 276         assert(s);
 277         assert(fd == i->fifo_fd);
 278         assert(i);
 279
 280         inhibitor_stop(i);
 281         inhibitor_free(i);
 282
 283         return 0;
 284 }
 285
 286 int inhibitor_create_fifo(Inhibitor *i) {
 287         int r;
 288
 289         assert(i);
 290
 291         /* Create FIFO */
 292         if (!i->fifo_path) {
 293                 r = mkdir_safe_label("/run/systemd/inhibit", 0755, 0, 0);
 294                 if (r < 0)
 295                         return r;
 296
 297                 i->fifo_path = strjoin("/run/systemd/inhibit/", i->id, ".ref");
 298                 if (!i->fifo_path)
 299                         return -ENOMEM;
 300
 301                 if (mkfifo(i->fifo_path, 0600) < 0 && errno != EEXIST)
 302                         return -errno;
 303         }
 304
 305         /* Open reading side */
 306         if (i->fifo_fd < 0) {
 307                 i->fifo_fd = open(i->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
 308                 if (i->fifo_fd < 0)
 309                         return -errno;
 310         }
 311
 312         if (!i->event_source) {
 313                 r = sd_event_add_io(i->manager->event, &i->event_source, i->fifo_fd, 0, inhibitor_dispatch_fifo, i);
 314                 if (r < 0)
 315                         return r;
 316
 317                 r = sd_event_source_set_priority(i->event_source, SD_EVENT_PRIORITY_IDLE-10);
 318                 if (r < 0)
 319                         return r;
 320         }
 321
 322         /* Open writing side */
 323         r = open(i->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
 324         if (r < 0)
 325                 return -errno;
 326
 327         return r;
 328 }
 329
 330 void inhibitor_remove_fifo(Inhibitor *i) {
 331         assert(i);
 332
 333         i->event_source = sd_event_source_unref(i->event_source);
 334         i->fifo_fd = safe_close(i->fifo_fd);
 335
 336         if (i->fifo_path) {
 337                 unlink(i->fifo_path);
 338                 i->fifo_path = mfree(i->fifo_path);
 339         }
 340 }
 341
 342 InhibitWhat manager_inhibit_what(Manager *m, InhibitMode mm) {
 343         Inhibitor *i;
 344         Iterator j;
 345         InhibitWhat what = 0;
 346
 347         assert(m);
 348
 349         HASHMAP_FOREACH(i, m->inhibitors, j)
 350                 if (i->mode == mm)
 351                         what |= i->what;
 352
 353         return what;
 354 }
 355
 356 static int pid_is_active(Manager *m, pid_t pid) {
 357         Session *s;
 358         int r;
 359
 360         r = manager_get_session_by_pid(m, pid, &s);
 361         if (r < 0)
 362                 return r;
 363
 364         /* If there's no session assigned to it, then it's globally
 365          * active on all ttys */
 366         if (r == 0)
 367                 return 1;
 368
 369         return session_is_active(s);
 370 }
 371
 372 bool manager_is_inhibited(
 373                 Manager *m,
 374                 InhibitWhat w,
 375                 InhibitMode mm,
 376                 dual_timestamp *since,
 377                 bool ignore_inactive,
 378                 bool ignore_uid,
 379                 uid_t uid,
 380                 Inhibitor **offending) {
 381
 382         Inhibitor *i;
 383         Iterator j;
 384         struct dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 385         bool inhibited = false;
 386
 387         assert(m);
 388         assert(w > 0 && w < _INHIBIT_WHAT_MAX);
 389
 390         HASHMAP_FOREACH(i, m->inhibitors, j) {
 391                 if (!(i->what & w))
 392                         continue;
 393
 394                 if (i->mode != mm)
 395                         continue;
 396
 397                 if (ignore_inactive && pid_is_active(m, i->pid) <= 0)
 398                         continue;
 399
 400                 if (ignore_uid && i->uid == uid)
 401                         continue;
 402
 403                 if (!inhibited ||
 404                     i->since.monotonic < ts.monotonic)
 405                         ts = i->since;
 406
 407                 inhibited = true;
 408
 409                 if (offending)
 410                         *offending = i;
 411         }
 412
 413         if (since)
 414                 *since = ts;
 415
 416         return inhibited;
 417 }
 418
 419 const char *inhibit_what_to_string(InhibitWhat w) {
 420         static thread_local char buffer[97];
 421         char *p;
 422
 423         if (w < 0 || w >= _INHIBIT_WHAT_MAX)
 424                 return NULL;
 425
 426         p = buffer;
 427         if (w & INHIBIT_SHUTDOWN)
 428                 p = stpcpy(p, "shutdown:");
 429         if (w & INHIBIT_SLEEP)
 430                 p = stpcpy(p, "sleep:");
 431         if (w & INHIBIT_IDLE)
 432                 p = stpcpy(p, "idle:");
 433         if (w & INHIBIT_HANDLE_POWER_KEY)
 434                 p = stpcpy(p, "handle-power-key:");
 435         if (w & INHIBIT_HANDLE_SUSPEND_KEY)
 436                 p = stpcpy(p, "handle-suspend-key:");
 437         if (w & INHIBIT_HANDLE_HIBERNATE_KEY)
 438                 p = stpcpy(p, "handle-hibernate-key:");
 439         if (w & INHIBIT_HANDLE_LID_SWITCH)
 440                 p = stpcpy(p, "handle-lid-switch:");
 441
 442         if (p > buffer)
 443                 *(p-1) = 0;
 444         else
 445                 *p = 0;
 446
 447         return buffer;
 448 }
 449
 450 InhibitWhat inhibit_what_from_string(const char *s) {
 451         InhibitWhat what = 0;
 452         const char *word, *state;
 453         size_t l;
 454
 455         FOREACH_WORD_SEPARATOR(word, l, s, ":", state) {
 456                 if (l == 8 && strneq(word, "shutdown", l))
 457                         what |= INHIBIT_SHUTDOWN;
 458                 else if (l == 5 && strneq(word, "sleep", l))
 459                         what |= INHIBIT_SLEEP;
 460                 else if (l == 4 && strneq(word, "idle", l))
 461                         what |= INHIBIT_IDLE;
 462                 else if (l == 16 && strneq(word, "handle-power-key", l))
 463                         what |= INHIBIT_HANDLE_POWER_KEY;
 464                 else if (l == 18 && strneq(word, "handle-suspend-key", l))
 465                         what |= INHIBIT_HANDLE_SUSPEND_KEY;
 466                 else if (l == 20 && strneq(word, "handle-hibernate-key", l))
 467                         what |= INHIBIT_HANDLE_HIBERNATE_KEY;
 468                 else if (l == 17 && strneq(word, "handle-lid-switch", l))
 469                         what |= INHIBIT_HANDLE_LID_SWITCH;
 470                 else
 471                         return _INHIBIT_WHAT_INVALID;
 472         }
 473
 474         return what;
 475 }
 476
 477 static const char* const inhibit_mode_table[_INHIBIT_MODE_MAX] = {
 478         [INHIBIT_BLOCK] = "block",
 479         [INHIBIT_DELAY] = "delay"
 480 };
 481
 482 DEFINE_STRING_TABLE_LOOKUP(inhibit_mode, InhibitMode);