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 <sys/epoll.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <unistd.h>
  28
  29 #include "util.h"
  30 #include "mkdir.h"
  31 #include "path-util.h"
  32 #include "logind-inhibit.h"
  33 #include "fileio.h"
  34
  35 Inhibitor* inhibitor_new(Manager *m, const char* id) {
  36         Inhibitor *i;
  37
  38         assert(m);
  39
  40         i = new0(Inhibitor, 1);
  41         if (!i)
  42                 return NULL;
  43
  44         i->state_file = strappend("/run/systemd/inhibit/", id);
  45         if (!i->state_file) {
  46                 free(i);
  47                 return NULL;
  48         }
  49
  50         i->id = path_get_file_name(i->state_file);
  51
  52         if (hashmap_put(m->inhibitors, i->id, i) < 0) {
  53                 free(i->state_file);
  54                 free(i);
  55                 return NULL;
  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         free(i->who);
  68         free(i->why);
  69
  70         hashmap_remove(i->manager->inhibitors, i->id);
  71         inhibitor_remove_fifo(i);
  72
  73         if (i->state_file) {
  74                 unlink(i->state_file);
  75                 free(i->state_file);
  76         }
  77
  78         free(i);
  79 }
  80
  81 int inhibitor_save(Inhibitor *i) {
  82         char *temp_path, *cc;
  83         int r;
  84         FILE *f;
  85
  86         assert(i);
  87
  88         r = mkdir_safe_label("/run/systemd/inhibit", 0755, 0, 0);
  89         if (r < 0)
  90                 goto finish;
  91
  92         r = fopen_temporary(i->state_file, &f, &temp_path);
  93         if (r < 0)
  94                 goto finish;
  95
  96         fchmod(fileno(f), 0644);
  97
  98         fprintf(f,
  99                 "# This is private data. Do not parse.\n"
 100                 "WHAT=%s\n"
 101                 "MODE=%s\n"
 102                 "UID=%lu\n"
 103                 "PID=%lu\n",
 104                 inhibit_what_to_string(i->what),
 105                 inhibit_mode_to_string(i->mode),
 106                 (unsigned long) i->uid,
 107                 (unsigned long) i->pid);
 108
 109         if (i->who) {
 110                 cc = cescape(i->who);
 111                 if (!cc)
 112                         r = -ENOMEM;
 113                 else {
 114                         fprintf(f, "WHO=%s\n", cc);
 115                         free(cc);
 116                 }
 117         }
 118
 119         if (i->why) {
 120                 cc = cescape(i->why);
 121                 if (!cc)
 122                         r = -ENOMEM;
 123                 else {
 124                         fprintf(f, "WHY=%s\n", cc);
 125                         free(cc);
 126                 }
 127         }
 128
 129         if (i->fifo_path)
 130                 fprintf(f, "FIFO=%s\n", i->fifo_path);
 131
 132         fflush(f);
 133
 134         if (ferror(f) || rename(temp_path, i->state_file) < 0) {
 135                 r = -errno;
 136                 unlink(i->state_file);
 137                 unlink(temp_path);
 138         }
 139
 140         fclose(f);
 141         free(temp_path);
 142
 143 finish:
 144         if (r < 0)
 145                 log_error("Failed to save inhibit data for %s: %s", i->id, strerror(-r));
 146
 147         return r;
 148 }
 149
 150 int inhibitor_start(Inhibitor *i) {
 151         assert(i);
 152
 153         if (i->started)
 154                 return 0;
 155
 156         dual_timestamp_get(&i->since);
 157
 158         log_debug("Inhibitor %s (%s) pid=%lu uid=%lu mode=%s started.",
 159                   strna(i->who), strna(i->why),
 160                   (unsigned long) i->pid, (unsigned long) i->uid,
 161                   inhibit_mode_to_string(i->mode));
 162
 163         inhibitor_save(i);
 164
 165         i->started = true;
 166
 167         manager_send_changed(i->manager, i->mode == INHIBIT_BLOCK ? "BlockInhibited\0" : "DelayInhibited\0");
 168
 169         return 0;
 170 }
 171
 172 int inhibitor_stop(Inhibitor *i) {
 173         assert(i);
 174
 175         if (i->started)
 176                 log_debug("Inhibitor %s (%s) pid=%lu uid=%lu mode=%s stopped.",
 177                           strna(i->who), strna(i->why),
 178                           (unsigned long) i->pid, (unsigned long) i->uid,
 179                           inhibit_mode_to_string(i->mode));
 180
 181         if (i->state_file)
 182                 unlink(i->state_file);
 183
 184         i->started = false;
 185
 186         manager_send_changed(i->manager, i->mode == INHIBIT_BLOCK ? "BlockInhibited\0" : "DelayInhibited\0");
 187
 188         return 0;
 189 }
 190
 191 int inhibitor_load(Inhibitor *i) {
 192         InhibitWhat w;
 193         InhibitMode mm;
 194         int r;
 195         char *cc,
 196                 *what = NULL,
 197                 *uid = NULL,
 198                 *pid = NULL,
 199                 *who = NULL,
 200                 *why = NULL,
 201                 *mode = NULL;
 202
 203         r = parse_env_file(i->state_file, NEWLINE,
 204                            "WHAT", &what,
 205                            "UID", &uid,
 206                            "PID", &pid,
 207                            "WHO", &who,
 208                            "WHY", &why,
 209                            "MODE", &mode,
 210                            "FIFO", &i->fifo_path,
 211                            NULL);
 212         if (r < 0)
 213                 goto finish;
 214
 215         w = what ? inhibit_what_from_string(what) : 0;
 216         if (w >= 0)
 217                 i->what = w;
 218
 219         mm = mode ? inhibit_mode_from_string(mode) : INHIBIT_BLOCK;
 220         if  (mm >= 0)
 221                 i->mode = mm;
 222
 223         if (uid) {
 224                 r = parse_uid(uid, &i->uid);
 225                 if (r < 0)
 226                         goto finish;
 227         }
 228
 229         if (pid) {
 230                 r = parse_pid(pid, &i->pid);
 231                 if (r < 0)
 232                         goto finish;
 233         }
 234
 235         if (who) {
 236                 cc = cunescape(who);
 237                 if (!cc) {
 238                         r = -ENOMEM;
 239                         goto finish;
 240                 }
 241
 242                 free(i->who);
 243                 i->who = cc;
 244         }
 245
 246         if (why) {
 247                 cc = cunescape(why);
 248                 if (!cc) {
 249                         r = -ENOMEM;
 250                         goto finish;
 251                 }
 252
 253                 free(i->why);
 254                 i->why = cc;
 255         }
 256
 257         if (i->fifo_path) {
 258                 int fd;
 259
 260                 fd = inhibitor_create_fifo(i);
 261                 if (fd >= 0)
 262                         close_nointr_nofail(fd);
 263         }
 264
 265 finish:
 266         free(what);
 267         free(uid);
 268         free(pid);
 269         free(who);
 270         free(why);
 271
 272         return r;
 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                 if (asprintf(&i->fifo_path, "/run/systemd/inhibit/%s.ref", i->id) < 0)
 287                         return -ENOMEM;
 288
 289                 if (mkfifo(i->fifo_path, 0600) < 0 && errno != EEXIST)
 290                         return -errno;
 291         }
 292
 293         /* Open reading side */
 294         if (i->fifo_fd < 0) {
 295                 struct epoll_event ev = {};
 296
 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                 r = hashmap_put(i->manager->inhibitor_fds, INT_TO_PTR(i->fifo_fd + 1), i);
 302                 if (r < 0)
 303                         return r;
 304
 305                 ev.events = 0;
 306                 ev.data.u32 = FD_OTHER_BASE + i->fifo_fd;
 307
 308                 if (epoll_ctl(i->manager->epoll_fd, EPOLL_CTL_ADD, i->fifo_fd, &ev) < 0)
 309                         return -errno;
 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->fifo_fd >= 0) {
 324                 assert_se(hashmap_remove(i->manager->inhibitor_fds, INT_TO_PTR(i->fifo_fd + 1)) == i);
 325                 assert_se(epoll_ctl(i->manager->epoll_fd, EPOLL_CTL_DEL, i->fifo_fd, NULL) == 0);
 326                 close_nointr_nofail(i->fifo_fd);
 327                 i->fifo_fd = -1;
 328         }
 329
 330         if (i->fifo_path) {
 331                 unlink(i->fifo_path);
 332                 free(i->fifo_path);
 333                 i->fifo_path = NULL;
 334         }
 335 }
 336
 337 InhibitWhat manager_inhibit_what(Manager *m, InhibitMode mm) {
 338         Inhibitor *i;
 339         Iterator j;
 340         InhibitWhat what = 0;
 341
 342         assert(m);
 343
 344         HASHMAP_FOREACH(i, m->inhibitor_fds, j)
 345                 if (i->mode == mm)
 346                         what |= i->what;
 347
 348         return what;
 349 }
 350
 351 static int pid_is_active(Manager *m, pid_t pid) {
 352         Session *s;
 353         int r;
 354
 355         r = manager_get_session_by_pid(m, pid, &s);
 356         if (r < 0)
 357                 return r;
 358
 359         /* If there's no session assigned to it, then it's globally
 360          * active on all ttys */
 361         if (r == 0)
 362                 return 1;
 363
 364         return session_is_active(s);
 365 }
 366
 367 bool manager_is_inhibited(
 368                 Manager *m,
 369                 InhibitWhat w,
 370                 InhibitMode mm,
 371                 dual_timestamp *since,
 372                 bool ignore_inactive,
 373                 bool ignore_uid,
 374                 uid_t uid) {
 375
 376         Inhibitor *i;
 377         Iterator j;
 378         struct dual_timestamp ts = { 0, 0 };
 379         bool inhibited = false;
 380
 381         assert(m);
 382         assert(w > 0 && w < _INHIBIT_WHAT_MAX);
 383
 384         HASHMAP_FOREACH(i, m->inhibitor_fds, j) {
 385                 if (!(i->what & w))
 386                         continue;
 387
 388                 if (i->mode != mm)
 389                         continue;
 390
 391                 if (ignore_inactive && pid_is_active(m, i->pid) <= 0)
 392                         continue;
 393
 394                 if (ignore_uid && i->uid == uid)
 395                         continue;
 396
 397                 if (!inhibited ||
 398                     i->since.monotonic < ts.monotonic)
 399                         ts = i->since;
 400
 401                 inhibited = true;
 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 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         char *w, *state;
 444         size_t l;
 445
 446         FOREACH_WORD_SEPARATOR(w, l, s, ":", state) {
 447                 if (l == 8 && strneq(w, "shutdown", l))
 448                         what |= INHIBIT_SHUTDOWN;
 449                 else if (l == 5 && strneq(w, "sleep", l))
 450                         what |= INHIBIT_SLEEP;
 451                 else if (l == 4 && strneq(w, "idle", l))
 452                         what |= INHIBIT_IDLE;
 453                 else if (l == 16 && strneq(w, "handle-power-key", l))
 454                         what |= INHIBIT_HANDLE_POWER_KEY;
 455                 else if (l == 18 && strneq(w, "handle-suspend-key", l))
 456                         what |= INHIBIT_HANDLE_SUSPEND_KEY;
 457                 else if (l == 20 && strneq(w, "handle-hibernate-key", l))
 458                         what |= INHIBIT_HANDLE_HIBERNATE_KEY;
 459                 else if (l == 17 && strneq(w, "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);