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 "formats-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                 free(i);
  50                 return NULL;
  51         }
  52
  53         i->id = basename(i->state_file);
  54
  55         if (hashmap_put(m->inhibitors, i->id, i) < 0) {
  56                 free(i->state_file);
  57                 free(i);
  58                 return NULL;
  59         }
  60
  61         i->manager = m;
  62         i->fifo_fd = -1;
  63
  64         return i;
  65 }
  66
  67 void inhibitor_free(Inhibitor *i) {
  68         assert(i);
  69
  70         hashmap_remove(i->manager->inhibitors, i->id);
  71
  72         inhibitor_remove_fifo(i);
  73
  74         free(i->who);
  75         free(i->why);
  76
  77         if (i->state_file) {
  78                 unlink(i->state_file);
  79                 free(i->state_file);
  80         }
  81
  82         free(i);
  83 }
  84
  85 int inhibitor_save(Inhibitor *i) {
  86         _cleanup_free_ char *temp_path = NULL;
  87         _cleanup_fclose_ FILE *f = NULL;
  88         int r;
  89
  90         assert(i);
  91
  92         r = mkdir_safe_label("/run/systemd/inhibit", 0755, 0, 0);
  93         if (r < 0)
  94                 goto fail;
  95
  96         r = fopen_temporary(i->state_file, &f, &temp_path);
  97         if (r < 0)
  98                 goto fail;
  99
 100         fchmod(fileno(f), 0644);
 101
 102         fprintf(f,
 103                 "# This is private data. Do not parse.\n"
 104                 "WHAT=%s\n"
 105                 "MODE=%s\n"
 106                 "UID="UID_FMT"\n"
 107                 "PID="PID_FMT"\n",
 108                 inhibit_what_to_string(i->what),
 109                 inhibit_mode_to_string(i->mode),
 110                 i->uid,
 111                 i->pid);
 112
 113         if (i->who) {
 114                 _cleanup_free_ char *cc = NULL;
 115
 116                 cc = cescape(i->who);
 117                 if (!cc) {
 118                         r = -ENOMEM;
 119                         goto fail;
 120                 }
 121
 122                 fprintf(f, "WHO=%s\n", cc);
 123         }
 124
 125         if (i->why) {
 126                 _cleanup_free_ char *cc = NULL;
 127
 128                 cc = cescape(i->why);
 129                 if (!cc) {
 130                         r = -ENOMEM;
 131                         goto fail;
 132                 }
 133
 134                 fprintf(f, "WHY=%s\n", cc);
 135         }
 136
 137         if (i->fifo_path)
 138                 fprintf(f, "FIFO=%s\n", i->fifo_path);
 139
 140         r = fflush_and_check(f);
 141         if (r < 0)
 142                 goto fail;
 143
 144         if (rename(temp_path, i->state_file) < 0) {
 145                 r = -errno;
 146                 goto fail;
 147         }
 148
 149         return 0;
 150
 151 fail:
 152         (void) unlink(i->state_file);
 153
 154         if (temp_path)
 155                 (void) unlink(temp_path);
 156
 157         return log_error_errno(r, "Failed to save inhibit data %s: %m", i->state_file);
 158 }
 159
 160 int inhibitor_start(Inhibitor *i) {
 161         assert(i);
 162
 163         if (i->started)
 164                 return 0;
 165
 166         dual_timestamp_get(&i->since);
 167
 168         log_debug("Inhibitor %s (%s) pid="PID_FMT" uid="UID_FMT" mode=%s started.",
 169                   strna(i->who), strna(i->why),
 170                   i->pid, i->uid,
 171                   inhibit_mode_to_string(i->mode));
 172
 173         inhibitor_save(i);
 174
 175         i->started = true;
 176
 177         manager_send_changed(i->manager, i->mode == INHIBIT_BLOCK ? "BlockInhibited" : "DelayInhibited", NULL);
 178
 179         return 0;
 180 }
 181
 182 int inhibitor_stop(Inhibitor *i) {
 183         assert(i);
 184
 185         if (i->started)
 186                 log_debug("Inhibitor %s (%s) pid="PID_FMT" uid="UID_FMT" mode=%s stopped.",
 187                           strna(i->who), strna(i->why),
 188                           i->pid, i->uid,
 189                           inhibit_mode_to_string(i->mode));
 190
 191         if (i->state_file)
 192                 unlink(i->state_file);
 193
 194         i->started = false;
 195
 196         manager_send_changed(i->manager, i->mode == INHIBIT_BLOCK ? "BlockInhibited" : "DelayInhibited", NULL);
 197
 198         return 0;
 199 }
 200
 201 int inhibitor_load(Inhibitor *i) {
 202
 203         _cleanup_free_ char
 204                 *what = NULL,
 205                 *uid = NULL,
 206                 *pid = NULL,
 207                 *who = NULL,
 208                 *why = NULL,
 209                 *mode = NULL;
 210
 211         InhibitWhat w;
 212         InhibitMode mm;
 213         char *cc;
 214         int r;
 215
 216         r = parse_env_file(i->state_file, NEWLINE,
 217                            "WHAT", &what,
 218                            "UID", &uid,
 219                            "PID", &pid,
 220                            "WHO", &who,
 221                            "WHY", &why,
 222                            "MODE", &mode,
 223                            "FIFO", &i->fifo_path,
 224                            NULL);
 225         if (r < 0)
 226                 return r;
 227
 228         w = what ? inhibit_what_from_string(what) : 0;
 229         if (w >= 0)
 230                 i->what = w;
 231
 232         mm = mode ? inhibit_mode_from_string(mode) : INHIBIT_BLOCK;
 233         if  (mm >= 0)
 234                 i->mode = mm;
 235
 236         if (uid) {
 237                 r = parse_uid(uid, &i->uid);
 238                 if (r < 0)
 239                         return r;
 240         }
 241
 242         if (pid) {
 243                 r = parse_pid(pid, &i->pid);
 244                 if (r < 0)
 245                         return r;
 246         }
 247
 248         if (who) {
 249                 r = cunescape(who, 0, &cc);
 250                 if (r < 0)
 251                         return r;
 252
 253                 free(i->who);
 254                 i->who = cc;
 255         }
 256
 257         if (why) {
 258                 r = cunescape(why, 0, &cc);
 259                 if (r < 0)
 260                         return r;
 261
 262                 free(i->why);
 263                 i->why = cc;
 264         }
 265
 266         if (i->fifo_path) {
 267                 int fd;
 268
 269                 fd = inhibitor_create_fifo(i);
 270                 safe_close(fd);
 271         }
 272
 273         return 0;
 274 }
 275
 276 static int inhibitor_dispatch_fifo(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 277         Inhibitor *i = userdata;
 278
 279         assert(s);
 280         assert(fd == i->fifo_fd);
 281         assert(i);
 282
 283         inhibitor_stop(i);
 284         inhibitor_free(i);
 285
 286         return 0;
 287 }
 288
 289 int inhibitor_create_fifo(Inhibitor *i) {
 290         int r;
 291
 292         assert(i);
 293
 294         /* Create FIFO */
 295         if (!i->fifo_path) {
 296                 r = mkdir_safe_label("/run/systemd/inhibit", 0755, 0, 0);
 297                 if (r < 0)
 298                         return r;
 299
 300                 i->fifo_path = strjoin("/run/systemd/inhibit/", i->id, ".ref", NULL);
 301                 if (!i->fifo_path)
 302                         return -ENOMEM;
 303
 304                 if (mkfifo(i->fifo_path, 0600) < 0 && errno != EEXIST)
 305                         return -errno;
 306         }
 307
 308         /* Open reading side */
 309         if (i->fifo_fd < 0) {
 310                 i->fifo_fd = open(i->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
 311                 if (i->fifo_fd < 0)
 312                         return -errno;
 313         }
 314
 315         if (!i->event_source) {
 316                 r = sd_event_add_io(i->manager->event, &i->event_source, i->fifo_fd, 0, inhibitor_dispatch_fifo, i);
 317                 if (r < 0)
 318                         return r;
 319
 320                 r = sd_event_source_set_priority(i->event_source, SD_EVENT_PRIORITY_IDLE);
 321                 if (r < 0)
 322                         return r;
 323         }
 324
 325         /* Open writing side */
 326         r = open(i->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
 327         if (r < 0)
 328                 return -errno;
 329
 330         return r;
 331 }
 332
 333 void inhibitor_remove_fifo(Inhibitor *i) {
 334         assert(i);
 335
 336         i->event_source = sd_event_source_unref(i->event_source);
 337         i->fifo_fd = safe_close(i->fifo_fd);
 338
 339         if (i->fifo_path) {
 340                 unlink(i->fifo_path);
 341                 i->fifo_path = mfree(i->fifo_path);
 342         }
 343 }
 344
 345 InhibitWhat manager_inhibit_what(Manager *m, InhibitMode mm) {
 346         Inhibitor *i;
 347         Iterator j;
 348         InhibitWhat what = 0;
 349
 350         assert(m);
 351
 352         HASHMAP_FOREACH(i, m->inhibitors, j)
 353                 if (i->mode == mm)
 354                         what |= i->what;
 355
 356         return what;
 357 }
 358
 359 static int pid_is_active(Manager *m, pid_t pid) {
 360         Session *s;
 361         int r;
 362
 363         r = manager_get_session_by_pid(m, pid, &s);
 364         if (r < 0)
 365                 return r;
 366
 367         /* If there's no session assigned to it, then it's globally
 368          * active on all ttys */
 369         if (r == 0)
 370                 return 1;
 371
 372         return session_is_active(s);
 373 }
 374
 375 bool manager_is_inhibited(
 376                 Manager *m,
 377                 InhibitWhat w,
 378                 InhibitMode mm,
 379                 dual_timestamp *since,
 380                 bool ignore_inactive,
 381                 bool ignore_uid,
 382                 uid_t uid,
 383                 Inhibitor **offending) {
 384
 385         Inhibitor *i;
 386         Iterator j;
 387         struct dual_timestamp ts = DUAL_TIMESTAMP_NULL;
 388         bool inhibited = false;
 389
 390         assert(m);
 391         assert(w > 0 && w < _INHIBIT_WHAT_MAX);
 392
 393         HASHMAP_FOREACH(i, m->inhibitors, j) {
 394                 if (!(i->what & w))
 395                         continue;
 396
 397                 if (i->mode != mm)
 398                         continue;
 399
 400                 if (ignore_inactive && pid_is_active(m, i->pid) <= 0)
 401                         continue;
 402
 403                 if (ignore_uid && i->uid == uid)
 404                         continue;
 405
 406                 if (!inhibited ||
 407                     i->since.monotonic < ts.monotonic)
 408                         ts = i->since;
 409
 410                 inhibited = true;
 411
 412                 if (offending)
 413                         *offending = i;
 414         }
 415
 416         if (since)
 417                 *since = ts;
 418
 419         return inhibited;
 420 }
 421
 422 const char *inhibit_what_to_string(InhibitWhat w) {
 423         static thread_local char buffer[97];
 424         char *p;
 425
 426         if (w < 0 || w >= _INHIBIT_WHAT_MAX)
 427                 return NULL;
 428
 429         p = buffer;
 430         if (w & INHIBIT_SHUTDOWN)
 431                 p = stpcpy(p, "shutdown:");
 432         if (w & INHIBIT_SLEEP)
 433                 p = stpcpy(p, "sleep:");
 434         if (w & INHIBIT_IDLE)
 435                 p = stpcpy(p, "idle:");
 436         if (w & INHIBIT_HANDLE_POWER_KEY)
 437                 p = stpcpy(p, "handle-power-key:");
 438         if (w & INHIBIT_HANDLE_SUSPEND_KEY)
 439                 p = stpcpy(p, "handle-suspend-key:");
 440         if (w & INHIBIT_HANDLE_HIBERNATE_KEY)
 441                 p = stpcpy(p, "handle-hibernate-key:");
 442         if (w & INHIBIT_HANDLE_LID_SWITCH)
 443                 p = stpcpy(p, "handle-lid-switch:");
 444
 445         if (p > buffer)
 446                 *(p-1) = 0;
 447         else
 448                 *p = 0;
 449
 450         return buffer;
 451 }
 452
 453 InhibitWhat inhibit_what_from_string(const char *s) {
 454         InhibitWhat what = 0;
 455         const char *word, *state;
 456         size_t l;
 457
 458         FOREACH_WORD_SEPARATOR(word, l, s, ":", state) {
 459                 if (l == 8 && strneq(word, "shutdown", l))
 460                         what |= INHIBIT_SHUTDOWN;
 461                 else if (l == 5 && strneq(word, "sleep", l))
 462                         what |= INHIBIT_SLEEP;
 463                 else if (l == 4 && strneq(word, "idle", l))
 464                         what |= INHIBIT_IDLE;
 465                 else if (l == 16 && strneq(word, "handle-power-key", l))
 466                         what |= INHIBIT_HANDLE_POWER_KEY;
 467                 else if (l == 18 && strneq(word, "handle-suspend-key", l))
 468                         what |= INHIBIT_HANDLE_SUSPEND_KEY;
 469                 else if (l == 20 && strneq(word, "handle-hibernate-key", l))
 470                         what |= INHIBIT_HANDLE_HIBERNATE_KEY;
 471                 else if (l == 17 && strneq(word, "handle-lid-switch", l))
 472                         what |= INHIBIT_HANDLE_LID_SWITCH;
 473                 else
 474                         return _INHIBIT_WHAT_INVALID;
 475         }
 476
 477         return what;
 478 }
 479
 480 static const char* const inhibit_mode_table[_INHIBIT_MODE_MAX] = {
 481         [INHIBIT_BLOCK] = "block",
 482         [INHIBIT_DELAY] = "delay"
 483 };
 484
 485 DEFINE_STRING_TABLE_LOOKUP(inhibit_mode, InhibitMode);