src/login/logind-inhibit.c

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