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="UID_FMT"\n"
 102                 "PID="PID_FMT"\n",
 103                 inhibit_what_to_string(i->what),
 104                 inhibit_mode_to_string(i->mode),
 105                 i->uid,
 106                 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 %s: %s", i->state_file, 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="PID_FMT" uid="UID_FMT" mode=%s started.",
 155                   strna(i->who), strna(i->why),
 156                   i->pid, 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="PID_FMT" uid="UID_FMT" mode=%s stopped.",
 173                           strna(i->who), strna(i->why),
 174                           i->pid, 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                 safe_close(fd);
 257         }
 258
 259         return 0;
 260 }
 261
 262 static int inhibitor_dispatch_fifo(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 263         Inhibitor *i = userdata;
 264
 265         assert(s);
 266         assert(fd == i->fifo_fd);
 267         assert(i);
 268
 269         inhibitor_stop(i);
 270         inhibitor_free(i);
 271
 272         return 0;
 273 }
 274
 275 int inhibitor_create_fifo(Inhibitor *i) {
 276         int r;
 277
 278         assert(i);
 279
 280         /* Create FIFO */
 281         if (!i->fifo_path) {
 282                 r = mkdir_safe_label("/run/systemd/inhibit", 0755, 0, 0);
 283                 if (r < 0)
 284                         return r;
 285
 286                 i->fifo_path = strjoin("/run/systemd/inhibit/", i->id, ".ref", NULL);
 287                 if (!i->fifo_path)
 288                         return -ENOMEM;
 289
 290                 if (mkfifo(i->fifo_path, 0600) < 0 && errno != EEXIST)
 291                         return -errno;
 292         }
 293
 294         /* Open reading side */
 295         if (i->fifo_fd < 0) {
 296                 i->fifo_fd = open(i->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
 297                 if (i->fifo_fd < 0)
 298                         return -errno;
 299         }
 300
 301         if (!i->event_source) {
 302                 r = sd_event_add_io(i->manager->event, &i->event_source, i->fifo_fd, 0, inhibitor_dispatch_fifo, i);
 303                 if (r < 0)
 304                         return r;
 305
 306                 r = sd_event_source_set_priority(i->event_source, SD_EVENT_PRIORITY_IDLE);
 307                 if (r < 0)
 308                         return r;
 309         }
 310
 311         /* Open writing side */
 312         r = open(i->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
 313         if (r < 0)
 314                 return -errno;
 315
 316         return r;
 317 }
 318
 319 void inhibitor_remove_fifo(Inhibitor *i) {
 320         assert(i);
 321
 322         i->event_source = sd_event_source_unref(i->event_source);
 323         i->fifo_fd = safe_close(i->fifo_fd);
 324
 325         if (i->fifo_path) {
 326                 unlink(i->fifo_path);
 327                 free(i->fifo_path);
 328                 i->fifo_path = NULL;
 329         }
 330 }
 331
 332 InhibitWhat manager_inhibit_what(Manager *m, InhibitMode mm) {
 333         Inhibitor *i;
 334         Iterator j;
 335         InhibitWhat what = 0;
 336
 337         assert(m);
 338
 339         HASHMAP_FOREACH(i, m->inhibitors, j)
 340                 if (i->mode == mm)
 341                         what |= i->what;
 342
 343         return what;
 344 }
 345
 346 static int pid_is_active(Manager *m, pid_t pid) {
 347         Session *s;
 348         int r;
 349
 350         r = manager_get_session_by_pid(m, pid, &s);
 351         if (r < 0)
 352                 return r;
 353
 354         /* If there's no session assigned to it, then it's globally
 355          * active on all ttys */
 356         if (r == 0)
 357                 return 1;
 358
 359         return session_is_active(s);
 360 }
 361
 362 bool manager_is_inhibited(
 363                 Manager *m,
 364                 InhibitWhat w,
 365                 InhibitMode mm,
 366                 dual_timestamp *since,
 367                 bool ignore_inactive,
 368                 bool ignore_uid,
 369                 uid_t uid,
 370                 Inhibitor **offending) {
 371
 372         Inhibitor *i;
 373         Iterator j;
 374         struct dual_timestamp ts = { 0, 0 };
 375         bool inhibited = false;
 376
 377         assert(m);
 378         assert(w > 0 && w < _INHIBIT_WHAT_MAX);
 379
 380         HASHMAP_FOREACH(i, m->inhibitors, j) {
 381                 if (!(i->what & w))
 382                         continue;
 383
 384                 if (i->mode != mm)
 385                         continue;
 386
 387                 if (ignore_inactive && pid_is_active(m, i->pid) <= 0)
 388                         continue;
 389
 390                 if (ignore_uid && i->uid == uid)
 391                         continue;
 392
 393                 if (!inhibited ||
 394                     i->since.monotonic < ts.monotonic)
 395                         ts = i->since;
 396
 397                 inhibited = true;
 398
 399                 if (offending)
 400                         *offending = i;
 401         }
 402
 403         if (since)
 404                 *since = ts;
 405
 406         return inhibited;
 407 }
 408
 409 const char *inhibit_what_to_string(InhibitWhat w) {
 410         static thread_local char buffer[97];
 411         char *p;
 412
 413         if (w < 0 || w >= _INHIBIT_WHAT_MAX)
 414                 return NULL;
 415
 416         p = buffer;
 417         if (w & INHIBIT_SHUTDOWN)
 418                 p = stpcpy(p, "shutdown:");
 419         if (w & INHIBIT_SLEEP)
 420                 p = stpcpy(p, "sleep:");
 421         if (w & INHIBIT_IDLE)
 422                 p = stpcpy(p, "idle:");
 423         if (w & INHIBIT_HANDLE_POWER_KEY)
 424                 p = stpcpy(p, "handle-power-key:");
 425         if (w & INHIBIT_HANDLE_SUSPEND_KEY)
 426                 p = stpcpy(p, "handle-suspend-key:");
 427         if (w & INHIBIT_HANDLE_HIBERNATE_KEY)
 428                 p = stpcpy(p, "handle-hibernate-key:");
 429         if (w & INHIBIT_HANDLE_LID_SWITCH)
 430                 p = stpcpy(p, "handle-lid-switch:");
 431
 432         if (p > buffer)
 433                 *(p-1) = 0;
 434         else
 435                 *p = 0;
 436
 437         return buffer;
 438 }
 439
 440 InhibitWhat inhibit_what_from_string(const char *s) {
 441         InhibitWhat what = 0;
 442         const char *word, *state;
 443         size_t l;
 444
 445         FOREACH_WORD_SEPARATOR(word, l, s, ":", state) {
 446                 if (l == 8 && strneq(word, "shutdown", l))
 447                         what |= INHIBIT_SHUTDOWN;
 448                 else if (l == 5 && strneq(word, "sleep", l))
 449                         what |= INHIBIT_SLEEP;
 450                 else if (l == 4 && strneq(word, "idle", l))
 451                         what |= INHIBIT_IDLE;
 452                 else if (l == 16 && strneq(word, "handle-power-key", l))
 453                         what |= INHIBIT_HANDLE_POWER_KEY;
 454                 else if (l == 18 && strneq(word, "handle-suspend-key", l))
 455                         what |= INHIBIT_HANDLE_SUSPEND_KEY;
 456                 else if (l == 20 && strneq(word, "handle-hibernate-key", l))
 457                         what |= INHIBIT_HANDLE_HIBERNATE_KEY;
 458                 else if (l == 17 && strneq(word, "handle-lid-switch", l))
 459                         what |= INHIBIT_HANDLE_LID_SWITCH;
 460                 else
 461                         return _INHIBIT_WHAT_INVALID;
 462         }
 463
 464         return what;
 465 }
 466
 467 static const char* const inhibit_mode_table[_INHIBIT_MODE_MAX] = {
 468         [INHIBIT_BLOCK] = "block",
 469         [INHIBIT_DELAY] = "delay"
 470 };
 471
 472 DEFINE_STRING_TABLE_LOOKUP(inhibit_mode, InhibitMode);