execute.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 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   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <assert.h>
  23 #include <dirent.h>
  24 #include <errno.h>
  25 #include <fcntl.h>
  26 #include <unistd.h>
  27 #include <string.h>
  28 #include <signal.h>
  29 #include <sys/socket.h>
  30 #include <sys/un.h>
  31 #include <sys/prctl.h>
  32 #include <linux/sched.h>
  33 #include <sys/types.h>
  34 #include <sys/stat.h>
  35 #include <grp.h>
  36 #include <pwd.h>
  37
  38 #include "execute.h"
  39 #include "strv.h"
  40 #include "macro.h"
  41 #include "util.h"
  42 #include "log.h"
  43 #include "ioprio.h"
  44 #include "securebits.h"
  45 #include "cgroup.h"
  46
  47 /* This assumes there is a 'tty' group */
  48 #define TTY_MODE 0620
  49
  50 static int shift_fds(int fds[], unsigned n_fds) {
  51         int start, restart_from;
  52
  53         if (n_fds <= 0)
  54                 return 0;
  55
  56         /* Modifies the fds array! (sorts it) */
  57
  58         assert(fds);
  59
  60         start = 0;
  61         for (;;) {
  62                 int i;
  63
  64                 restart_from = -1;
  65
  66                 for (i = start; i < (int) n_fds; i++) {
  67                         int nfd;
  68
  69                         /* Already at right index? */
  70                         if (fds[i] == i+3)
  71                                 continue;
  72
  73                         if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)
  74                                 return -errno;
  75
  76                         close_nointr_nofail(fds[i]);
  77                         fds[i] = nfd;
  78
  79                         /* Hmm, the fd we wanted isn't free? Then
  80                          * let's remember that and try again from here*/
  81                         if (nfd != i+3 && restart_from < 0)
  82                                 restart_from = i;
  83                 }
  84
  85                 if (restart_from < 0)
  86                         break;
  87
  88                 start = restart_from;
  89         }
  90
  91         return 0;
  92 }
  93
  94 static int flags_fds(const int fds[], unsigned n_fds, bool nonblock) {
  95         unsigned i;
  96         int r;
  97
  98         if (n_fds <= 0)
  99                 return 0;
 100
 101         assert(fds);
 102
 103         /* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags */
 104
 105         for (i = 0; i < n_fds; i++) {
 106
 107                 if ((r = fd_nonblock(fds[i], nonblock)) < 0)
 108                         return r;
 109
 110                 /* We unconditionally drop FD_CLOEXEC from the fds,
 111                  * since after all we want to pass these fds to our
 112                  * children */
 113
 114                 if ((r = fd_cloexec(fds[i], false)) < 0)
 115                         return r;
 116         }
 117
 118         return 0;
 119 }
 120
 121 static const char *tty_path(const ExecContext *context) {
 122         assert(context);
 123
 124         if (context->tty_path)
 125                 return context->tty_path;
 126
 127         return "/dev/console";
 128 }
 129
 130 static int open_null_as(int flags, int nfd) {
 131         int fd, r;
 132
 133         assert(nfd >= 0);
 134
 135         if ((fd = open("/dev/null", flags|O_NOCTTY)) < 0)
 136                 return -errno;
 137
 138         if (fd != nfd) {
 139                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 140                 close_nointr_nofail(fd);
 141         } else
 142                 r = nfd;
 143
 144         return r;
 145 }
 146
 147 static int connect_logger_as(const ExecContext *context, ExecOutput output, const char *ident, int nfd) {
 148         int fd, r;
 149         union {
 150                 struct sockaddr sa;
 151                 struct sockaddr_un un;
 152         } sa;
 153
 154         assert(context);
 155         assert(output < _EXEC_OUTPUT_MAX);
 156         assert(ident);
 157         assert(nfd >= 0);
 158
 159         if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 160                 return -errno;
 161
 162         zero(sa);
 163         sa.sa.sa_family = AF_UNIX;
 164         strncpy(sa.un.sun_path+1, LOGGER_SOCKET, sizeof(sa.un.sun_path)-1);
 165
 166         if (connect(fd, &sa.sa, sizeof(sa)) < 0) {
 167                 close_nointr_nofail(fd);
 168                 return -errno;
 169         }
 170
 171         if (shutdown(fd, SHUT_RD) < 0) {
 172                 close_nointr_nofail(fd);
 173                 return -errno;
 174         }
 175
 176         /* We speak a very simple protocol between log server
 177          * and client: one line for the log destination (kmsg
 178          * or syslog), followed by the priority field,
 179          * followed by the process name. Since we replaced
 180          * stdin/stderr we simple use stdio to write to
 181          * it. Note that we use stderr, to minimize buffer
 182          * flushing issues. */
 183
 184         dprintf(fd,
 185                 "%s\n"
 186                 "%i\n"
 187                 "%s\n",
 188                 output == EXEC_OUTPUT_KERNEL ? "kmsg" : "syslog",
 189                 context->syslog_priority,
 190                 context->syslog_identifier ? context->syslog_identifier : ident);
 191
 192         if (fd != nfd) {
 193                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 194                 close_nointr_nofail(fd);
 195         } else
 196                 r = nfd;
 197
 198         return r;
 199 }
 200 static int open_terminal_as(const char *path, mode_t mode, int nfd) {
 201         int fd, r;
 202
 203         assert(path);
 204         assert(nfd >= 0);
 205
 206         if ((fd = open_terminal(path, mode | O_NOCTTY)) < 0)
 207                 return fd;
 208
 209         if (fd != nfd) {
 210                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 211                 close_nointr_nofail(fd);
 212         } else
 213                 r = nfd;
 214
 215         return r;
 216 }
 217
 218 static bool is_terminal_input(ExecInput i) {
 219         return
 220                 i == EXEC_INPUT_TTY ||
 221                 i == EXEC_INPUT_TTY_FORCE ||
 222                 i == EXEC_INPUT_TTY_FAIL;
 223 }
 224
 225 static int setup_input(const ExecContext *context) {
 226         assert(context);
 227
 228         switch (context->std_input) {
 229
 230         case EXEC_INPUT_NULL:
 231                 return open_null_as(O_RDONLY, STDIN_FILENO);
 232
 233         case EXEC_INPUT_TTY:
 234         case EXEC_INPUT_TTY_FORCE:
 235         case EXEC_INPUT_TTY_FAIL: {
 236                 int fd, r;
 237
 238                 if ((fd = acquire_terminal(
 239                                      tty_path(context),
 240                                      context->std_input == EXEC_INPUT_TTY_FAIL,
 241                                      context->std_input == EXEC_INPUT_TTY_FORCE)) < 0)
 242                         return fd;
 243
 244                 if (fd != STDIN_FILENO) {
 245                         r = dup2(fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 246                         close_nointr_nofail(fd);
 247                 } else
 248                         r = STDIN_FILENO;
 249
 250                 return r;
 251         }
 252
 253         default:
 254                 assert_not_reached("Unknown input type");
 255         }
 256 }
 257
 258 static int setup_output(const ExecContext *context, const char *ident) {
 259         assert(context);
 260         assert(ident);
 261
 262         /* This expects the input is already set up */
 263
 264         switch (context->std_output) {
 265
 266         case EXEC_OUTPUT_INHERIT:
 267
 268                 /* If the input is connected to a terminal, inherit that... */
 269                 if (is_terminal_input(context->std_input))
 270                         return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;
 271
 272                 return 0;
 273
 274         case EXEC_OUTPUT_NULL:
 275                 return open_null_as(O_WRONLY, STDOUT_FILENO);
 276
 277         case EXEC_OUTPUT_TTY: {
 278                 if (is_terminal_input(context->std_input))
 279                         return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;
 280
 281                 /* We don't reset the terminal if this is just about output */
 282                 return open_terminal_as(tty_path(context), O_WRONLY, STDOUT_FILENO);
 283         }
 284
 285         case EXEC_OUTPUT_SYSLOG:
 286         case EXEC_OUTPUT_KERNEL:
 287                 return connect_logger_as(context, context->std_output, ident, STDOUT_FILENO);
 288
 289         default:
 290                 assert_not_reached("Unknown output type");
 291         }
 292 }
 293
 294 static int setup_error(const ExecContext *context, const char *ident) {
 295         assert(context);
 296         assert(ident);
 297
 298         /* This expects the input and output are already set up */
 299
 300         /* Don't change the stderr file descriptor if we inherit all
 301          * the way and are not on a tty */
 302         if (context->std_error == EXEC_OUTPUT_INHERIT &&
 303             context->std_output == EXEC_OUTPUT_INHERIT &&
 304             !is_terminal_input(context->std_input))
 305                 return STDERR_FILENO;
 306
 307         /* Duplicate form stdout if possible */
 308         if (context->std_error == context->std_output ||
 309             context->std_error == EXEC_OUTPUT_INHERIT)
 310                 return dup2(STDOUT_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;
 311
 312         switch (context->std_error) {
 313
 314         case EXEC_OUTPUT_NULL:
 315                 return open_null_as(O_WRONLY, STDERR_FILENO);
 316
 317         case EXEC_OUTPUT_TTY:
 318                 if (is_terminal_input(context->std_input))
 319                         return dup2(STDIN_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;
 320
 321                 /* We don't reset the terminal if this is just about output */
 322                 return open_terminal_as(tty_path(context), O_WRONLY, STDERR_FILENO);
 323
 324         case EXEC_OUTPUT_SYSLOG:
 325         case EXEC_OUTPUT_KERNEL:
 326                 return connect_logger_as(context, context->std_error, ident, STDERR_FILENO);
 327
 328         default:
 329                 assert_not_reached("Unknown error type");
 330         }
 331 }
 332
 333 static int chown_terminal(int fd, uid_t uid) {
 334         struct stat st;
 335
 336         assert(fd >= 0);
 337
 338         /* This might fail. What matters are the results. */
 339         fchown(fd, uid, -1);
 340         fchmod(fd, TTY_MODE);
 341
 342         if (fstat(fd, &st) < 0)
 343                 return -errno;
 344
 345         if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE)
 346                 return -EPERM;
 347
 348         return 0;
 349 }
 350
 351 static int setup_confirm_stdio(const ExecContext *context,
 352                                int *_saved_stdin,
 353                                int *_saved_stdout) {
 354         int fd = -1, saved_stdin, saved_stdout = -1, r;
 355
 356         assert(context);
 357         assert(_saved_stdin);
 358         assert(_saved_stdout);
 359
 360         /* This returns positive EXIT_xxx return values instead of
 361          * negative errno style values! */
 362
 363         if ((saved_stdin = fcntl(STDIN_FILENO, F_DUPFD, 3)) < 0)
 364                 return EXIT_STDIN;
 365
 366         if ((saved_stdout = fcntl(STDOUT_FILENO, F_DUPFD, 3)) < 0) {
 367                 r = EXIT_STDOUT;
 368                 goto fail;
 369         }
 370
 371         if ((fd = acquire_terminal(
 372                              tty_path(context),
 373                              context->std_input == EXEC_INPUT_TTY_FAIL,
 374                              context->std_input == EXEC_INPUT_TTY_FORCE)) < 0) {
 375                 r = EXIT_STDIN;
 376                 goto fail;
 377         }
 378
 379         if (chown_terminal(fd, getuid()) < 0) {
 380                 r = EXIT_STDIN;
 381                 goto fail;
 382         }
 383
 384         if (dup2(fd, STDIN_FILENO) < 0) {
 385                 r = EXIT_STDIN;
 386                 goto fail;
 387         }
 388
 389         if (dup2(fd, STDOUT_FILENO) < 0) {
 390                 r = EXIT_STDOUT;
 391                 goto fail;
 392         }
 393
 394         if (fd >= 2)
 395                 close_nointr_nofail(fd);
 396
 397         *_saved_stdin = saved_stdin;
 398         *_saved_stdout = saved_stdout;
 399
 400         return 0;
 401
 402 fail:
 403         if (saved_stdout >= 0)
 404                 close_nointr_nofail(saved_stdout);
 405
 406         if (saved_stdin >= 0)
 407                 close_nointr_nofail(saved_stdin);
 408
 409         if (fd >= 0)
 410                 close_nointr_nofail(fd);
 411
 412         return r;
 413 }
 414
 415 static int restore_conform_stdio(const ExecContext *context,
 416                                  int *saved_stdin,
 417                                  int *saved_stdout,
 418                                  bool *keep_stdin,
 419                                  bool *keep_stdout) {
 420
 421         assert(context);
 422         assert(saved_stdin);
 423         assert(*saved_stdin >= 0);
 424         assert(saved_stdout);
 425         assert(*saved_stdout >= 0);
 426
 427         /* This returns positive EXIT_xxx return values instead of
 428          * negative errno style values! */
 429
 430         if (is_terminal_input(context->std_input)) {
 431
 432                 /* The service wants terminal input. */
 433
 434                 *keep_stdin = true;
 435                 *keep_stdout =
 436                         context->std_output == EXEC_OUTPUT_INHERIT ||
 437                         context->std_output == EXEC_OUTPUT_TTY;
 438
 439         } else {
 440                 /* If the service doesn't want a controlling terminal,
 441                  * then we need to get rid entirely of what we have
 442                  * already. */
 443
 444                 if (release_terminal() < 0)
 445                         return EXIT_STDIN;
 446
 447                 if (dup2(*saved_stdin, STDIN_FILENO) < 0)
 448                         return EXIT_STDIN;
 449
 450                 if (dup2(*saved_stdout, STDOUT_FILENO) < 0)
 451                         return EXIT_STDOUT;
 452
 453                 *keep_stdout = *keep_stdin = false;
 454         }
 455
 456         return 0;
 457 }
 458
 459 static int get_group_creds(const char *groupname, gid_t *gid) {
 460         struct group *g;
 461         unsigned long lu;
 462
 463         assert(groupname);
 464         assert(gid);
 465
 466         /* We enforce some special rules for gid=0: in order to avoid
 467          * NSS lookups for root we hardcode its data. */
 468
 469         if (streq(groupname, "root") || streq(groupname, "0")) {
 470                 *gid = 0;
 471                 return 0;
 472         }
 473
 474         if (safe_atolu(groupname, &lu) >= 0) {
 475                 errno = 0;
 476                 g = getgrgid((gid_t) lu);
 477         } else {
 478                 errno = 0;
 479                 g = getgrnam(groupname);
 480         }
 481
 482         if (!g)
 483                 return errno != 0 ? -errno : -ESRCH;
 484
 485         *gid = g->gr_gid;
 486         return 0;
 487 }
 488
 489 static int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home) {
 490         struct passwd *p;
 491         unsigned long lu;
 492
 493         assert(username);
 494         assert(*username);
 495         assert(uid);
 496         assert(gid);
 497         assert(home);
 498
 499         /* We enforce some special rules for uid=0: in order to avoid
 500          * NSS lookups for root we hardcode its data. */
 501
 502         if (streq(*username, "root") || streq(*username, "0")) {
 503                 *username = "root";
 504                 *uid = 0;
 505                 *gid = 0;
 506                 *home = "/root";
 507                 return 0;
 508         }
 509
 510         if (safe_atolu(*username, &lu) >= 0) {
 511                 errno = 0;
 512                 p = getpwuid((uid_t) lu);
 513
 514                 /* If there are multiple users with the same id, make
 515                  * sure to leave $USER to the configured value instead
 516                  * of the first occurence in the database. However if
 517                  * the uid was configured by a numeric uid, then let's
 518                  * pick the real username from /etc/passwd. */
 519                 if (*username && p)
 520                         *username = p->pw_name;
 521         } else {
 522                 errno = 0;
 523                 p = getpwnam(*username);
 524         }
 525
 526         if (!p)
 527                 return errno != 0 ? -errno : -ESRCH;
 528
 529         *uid = p->pw_uid;
 530         *gid = p->pw_gid;
 531         *home = p->pw_dir;
 532         return 0;
 533 }
 534
 535 static int enforce_groups(const ExecContext *context, const char *username, gid_t gid) {
 536         bool keep_groups = false;
 537         int r;
 538
 539         assert(context);
 540
 541         /* Lookup and ser GID and supplementary group list. Here too
 542          * we avoid NSS lookups for gid=0. */
 543
 544         if (context->group || username) {
 545
 546                 if (context->group)
 547                         if ((r = get_group_creds(context->group, &gid)) < 0)
 548                                 return r;
 549
 550                 /* First step, initialize groups from /etc/groups */
 551                 if (username && gid != 0) {
 552                         if (initgroups(username, gid) < 0)
 553                                 return -errno;
 554
 555                         keep_groups = true;
 556                 }
 557
 558                 /* Second step, set our gids */
 559                 if (setresgid(gid, gid, gid) < 0)
 560                         return -errno;
 561         }
 562
 563         if (context->supplementary_groups) {
 564                 int ngroups_max, k;
 565                 gid_t *gids;
 566                 char **i;
 567
 568                 /* Final step, initialize any manually set supplementary groups */
 569                 ngroups_max = (int) sysconf(_SC_NGROUPS_MAX);
 570
 571                 if (!(gids = new(gid_t, ngroups_max)))
 572                         return -ENOMEM;
 573
 574                 if (keep_groups) {
 575                         if ((k = getgroups(ngroups_max, gids)) < 0) {
 576                                 free(gids);
 577                                 return -errno;
 578                         }
 579                 } else
 580                         k = 0;
 581
 582                 STRV_FOREACH(i, context->supplementary_groups) {
 583
 584                         if (k >= ngroups_max) {
 585                                 free(gids);
 586                                 return -E2BIG;
 587                         }
 588
 589                         if ((r = get_group_creds(*i, gids+k)) < 0) {
 590                                 free(gids);
 591                                 return r;
 592                         }
 593
 594                         k++;
 595                 }
 596
 597                 if (setgroups(k, gids) < 0) {
 598                         free(gids);
 599                         return -errno;
 600                 }
 601
 602                 free(gids);
 603         }
 604
 605         return 0;
 606 }
 607
 608 static int enforce_user(const ExecContext *context, uid_t uid) {
 609         int r;
 610         assert(context);
 611
 612         /* Sets (but doesn't lookup) the uid and make sure we keep the
 613          * capabilities while doing so. */
 614
 615         if (context->capabilities) {
 616                 cap_t d;
 617                 static const cap_value_t bits[] = {
 618                         CAP_SETUID,   /* Necessary so that we can run setresuid() below */
 619                         CAP_SETPCAP   /* Necessary so that we can set PR_SET_SECUREBITS later on */
 620                 };
 621
 622                 /* First step: If we need to keep capabilities but
 623                  * drop privileges we need to make sure we keep our
 624                  * caps, whiel we drop priviliges. */
 625                 if (uid != 0) {
 626                         int sb = context->secure_bits|SECURE_KEEP_CAPS;
 627
 628                         if (prctl(PR_GET_SECUREBITS) != sb)
 629                                 if (prctl(PR_SET_SECUREBITS, sb) < 0)
 630                                         return -errno;
 631                 }
 632
 633                 /* Second step: set the capabilites. This will reduce
 634                  * the capabilities to the minimum we need. */
 635
 636                 if (!(d = cap_dup(context->capabilities)))
 637                         return -errno;
 638
 639                 if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 ||
 640                     cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0) {
 641                         r = -errno;
 642                         cap_free(d);
 643                         return r;
 644                 }
 645
 646                 if (cap_set_proc(d) < 0) {
 647                         r = -errno;
 648                         cap_free(d);
 649                         return r;
 650                 }
 651
 652                 cap_free(d);
 653         }
 654
 655         /* Third step: actually set the uids */
 656         if (setresuid(uid, uid, uid) < 0)
 657                 return -errno;
 658
 659         /* At this point we should have all necessary capabilities but
 660            are otherwise a normal user. However, the caps might got
 661            corrupted due to the setresuid() so we need clean them up
 662            later. This is done outside of this call. */
 663
 664         return 0;
 665 }
 666
 667 int exec_spawn(ExecCommand *command,
 668                char **argv,
 669                const ExecContext *context,
 670                int fds[], unsigned n_fds,
 671                bool apply_permissions,
 672                bool apply_chroot,
 673                bool confirm_spawn,
 674                CGroupBonding *cgroup_bondings,
 675                pid_t *ret) {
 676
 677         pid_t pid;
 678         int r;
 679         char *line;
 680
 681         assert(command);
 682         assert(context);
 683         assert(ret);
 684         assert(fds || n_fds <= 0);
 685
 686         if (!argv)
 687                 argv = command->argv;
 688
 689         if (!(line = exec_command_line(argv)))
 690                 return -ENOMEM;
 691
 692         log_debug("About to execute: %s", line);
 693         free(line);
 694
 695         if (cgroup_bondings)
 696                 if ((r = cgroup_bonding_realize_list(cgroup_bondings)))
 697                         return r;
 698
 699         if ((pid = fork()) < 0)
 700                 return -errno;
 701
 702         if (pid == 0) {
 703                 int i;
 704                 sigset_t ss;
 705                 const char *username = NULL, *home = NULL;
 706                 uid_t uid = (uid_t) -1;
 707                 gid_t gid = (gid_t) -1;
 708                 char **our_env = NULL, **final_env = NULL;
 709                 unsigned n_env = 0;
 710                 int saved_stdout = -1, saved_stdin = -1;
 711                 bool keep_stdout = false, keep_stdin = false;
 712
 713                 /* child */
 714
 715                 reset_all_signal_handlers();
 716
 717                 if (sigemptyset(&ss) < 0 ||
 718                     sigprocmask(SIG_SETMASK, &ss, NULL) < 0) {
 719                         r = EXIT_SIGNAL_MASK;
 720                         goto fail;
 721                 }
 722
 723                 if (setsid() < 0) {
 724                         r = EXIT_SETSID;
 725                         goto fail;
 726                 }
 727
 728                 umask(context->umask);
 729
 730                 if (confirm_spawn) {
 731                         char response;
 732
 733                         /* Set up terminal for the question */
 734                         if ((r = setup_confirm_stdio(context,
 735                                                      &saved_stdin, &saved_stdout)))
 736                                 goto fail;
 737
 738                         /* Now ask the question. */
 739                         if (!(line = exec_command_line(argv))) {
 740                                 r = EXIT_MEMORY;
 741                                 goto fail;
 742                         }
 743
 744                         r = ask(&response, "yns", "Execute %s? [Yes, No, Skip] ", line);
 745                         free(line);
 746
 747                         if (r < 0 || response == 'n') {
 748                                 r = EXIT_CONFIRM;
 749                                 goto fail;
 750                         } else if (response == 's') {
 751                                 r = 0;
 752                                 goto fail;
 753                         }
 754
 755                         /* Release terminal for the question */
 756                         if ((r = restore_conform_stdio(context,
 757                                                        &saved_stdin, &saved_stdout,
 758                                                        &keep_stdin, &keep_stdout)))
 759                                 goto fail;
 760                 }
 761
 762                 if (!keep_stdin)
 763                         if (setup_input(context) < 0) {
 764                                 r = EXIT_STDIN;
 765                                 goto fail;
 766                         }
 767
 768                 if (!keep_stdout)
 769                         if (setup_output(context, file_name_from_path(command->path)) < 0) {
 770                                 r = EXIT_STDOUT;
 771                                 goto fail;
 772                         }
 773
 774                 if (setup_error(context, file_name_from_path(command->path)) < 0) {
 775                         r = EXIT_STDERR;
 776                         goto fail;
 777                 }
 778
 779                 if (cgroup_bondings)
 780                         if ((r = cgroup_bonding_install_list(cgroup_bondings, 0)) < 0) {
 781                                 r = EXIT_CGROUP;
 782                                 goto fail;
 783                         }
 784
 785                 if (context->oom_adjust_set) {
 786                         char t[16];
 787
 788                         snprintf(t, sizeof(t), "%i", context->oom_adjust);
 789                         char_array_0(t);
 790
 791                         if (write_one_line_file("/proc/self/oom_adj", t) < 0) {
 792                                 r = EXIT_OOM_ADJUST;
 793                                 goto fail;
 794                         }
 795                 }
 796
 797                 if (context->nice_set)
 798                         if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
 799                                 r = EXIT_NICE;
 800                                 goto fail;
 801                         }
 802
 803                 if (context->cpu_sched_set) {
 804                         struct sched_param param;
 805
 806                         zero(param);
 807                         param.sched_priority = context->cpu_sched_priority;
 808
 809                         if (sched_setscheduler(0, context->cpu_sched_policy |
 810                                                (context->cpu_sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0), &param) < 0) {
 811                                 r = EXIT_SETSCHEDULER;
 812                                 goto fail;
 813                         }
 814                 }
 815
 816                 if (context->cpu_affinity_set)
 817                         if (sched_setaffinity(0, sizeof(context->cpu_affinity), &context->cpu_affinity) < 0) {
 818                                 r = EXIT_CPUAFFINITY;
 819                                 goto fail;
 820                         }
 821
 822                 if (context->ioprio_set)
 823                         if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {
 824                                 r = EXIT_IOPRIO;
 825                                 goto fail;
 826                         }
 827
 828                 if (context->timer_slack_ns_set)
 829                         if (prctl(PR_SET_TIMERSLACK, context->timer_slack_ns_set) < 0) {
 830                                 r = EXIT_TIMERSLACK;
 831                                 goto fail;
 832                         }
 833
 834                 if (context->user) {
 835                         username = context->user;
 836                         if (get_user_creds(&username, &uid, &gid, &home) < 0) {
 837                                 r = EXIT_USER;
 838                                 goto fail;
 839                         }
 840
 841                         if (is_terminal_input(context->std_input))
 842                                 if (chown_terminal(STDIN_FILENO, uid) < 0) {
 843                                         r = EXIT_STDIN;
 844                                         goto fail;
 845                                 }
 846                 }
 847
 848                 if (apply_permissions)
 849                         if (enforce_groups(context, username, uid) < 0) {
 850                                 r = EXIT_GROUP;
 851                                 goto fail;
 852                         }
 853
 854                 if (apply_chroot) {
 855                         if (context->root_directory)
 856                                 if (chroot(context->root_directory) < 0) {
 857                                         r = EXIT_CHROOT;
 858                                         goto fail;
 859                                 }
 860
 861                         if (chdir(context->working_directory ? context->working_directory : "/") < 0) {
 862                                 r = EXIT_CHDIR;
 863                                 goto fail;
 864                         }
 865                 } else {
 866
 867                         char *d;
 868
 869                         if (asprintf(&d, "%s/%s",
 870                                      context->root_directory ? context->root_directory : "",
 871                                      context->working_directory ? context->working_directory : "") < 0) {
 872                                 r = EXIT_MEMORY;
 873                                 goto fail;
 874                         }
 875
 876                         if (chdir(d) < 0) {
 877                                 free(d);
 878                                 r = EXIT_CHDIR;
 879                                 goto fail;
 880                         }
 881
 882                         free(d);
 883                 }
 884
 885                 if (close_all_fds(fds, n_fds) < 0 ||
 886                     shift_fds(fds, n_fds) < 0 ||
 887                     flags_fds(fds, n_fds, context->non_blocking) < 0) {
 888                         r = EXIT_FDS;
 889                         goto fail;
 890                 }
 891
 892                 if (apply_permissions) {
 893
 894                         for (i = 0; i < RLIMIT_NLIMITS; i++) {
 895                                 if (!context->rlimit[i])
 896                                         continue;
 897
 898                                 if (setrlimit(i, context->rlimit[i]) < 0) {
 899                                         r = EXIT_LIMITS;
 900                                         goto fail;
 901                                 }
 902                         }
 903
 904                         if (context->user)
 905                                 if (enforce_user(context, uid) < 0) {
 906                                         r = EXIT_USER;
 907                                         goto fail;
 908                                 }
 909
 910                         /* PR_GET_SECUREBITS is not priviliged, while
 911                          * PR_SET_SECUREBITS is. So to suppress
 912                          * potential EPERMs we'll try not to call
 913                          * PR_SET_SECUREBITS unless necessary. */
 914                         if (prctl(PR_GET_SECUREBITS) != context->secure_bits)
 915                                 if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) {
 916                                         r = EXIT_SECUREBITS;
 917                                         goto fail;
 918                                 }
 919
 920                         if (context->capabilities)
 921                                 if (cap_set_proc(context->capabilities) < 0) {
 922                                         r = EXIT_CAPABILITIES;
 923                                         goto fail;
 924                                 }
 925                 }
 926
 927                 if (!(our_env = new0(char*, 6))) {
 928                         r = EXIT_MEMORY;
 929                         goto fail;
 930                 }
 931
 932                 if (n_fds > 0)
 933                         if (asprintf(our_env + n_env++, "LISTEN_PID=%llu", (unsigned long long) getpid()) < 0 ||
 934                             asprintf(our_env + n_env++, "LISTEN_FDS=%u", n_fds) < 0) {
 935                                 r = EXIT_MEMORY;
 936                                 goto fail;
 937                         }
 938
 939                 if (home)
 940                         if (asprintf(our_env + n_env++, "HOME=%s", home) < 0) {
 941                                 r = EXIT_MEMORY;
 942                                 goto fail;
 943                         }
 944
 945                 if (username)
 946                         if (asprintf(our_env + n_env++, "LOGNAME=%s", username) < 0 ||
 947                             asprintf(our_env + n_env++, "USER=%s", username) < 0) {
 948                                 r = EXIT_MEMORY;
 949                                 goto fail;
 950                         }
 951
 952                 if (!(final_env = strv_env_merge(environ, our_env, context->environment, NULL))) {
 953                         r = EXIT_MEMORY;
 954                         goto fail;
 955                 }
 956
 957                 execve(command->path, argv, final_env);
 958                 r = EXIT_EXEC;
 959
 960         fail:
 961                 strv_free(our_env);
 962                 strv_free(final_env);
 963
 964                 if (saved_stdin >= 0)
 965                         close_nointr_nofail(saved_stdin);
 966
 967                 if (saved_stdout >= 0)
 968                         close_nointr_nofail(saved_stdout);
 969
 970                 _exit(r);
 971         }
 972
 973         /* We add the new process to the cgroup both in the child (so
 974          * that we can be sure that no user code is ever executed
 975          * outside of the cgroup) and in the parent (so that we can be
 976          * sure that when we kill the cgroup the process will be
 977          * killed too). */
 978         if (cgroup_bondings)
 979                 if ((r = cgroup_bonding_install_list(cgroup_bondings, pid)) < 0) {
 980                         r = EXIT_CGROUP;
 981                         goto fail;
 982                 }
 983
 984         log_debug("Forked %s as %llu", command->path, (unsigned long long) pid);
 985
 986         command->exec_status.pid = pid;
 987         command->exec_status.start_timestamp = now(CLOCK_REALTIME);
 988
 989         *ret = pid;
 990         return 0;
 991 }
 992
 993 void exec_context_init(ExecContext *c) {
 994         assert(c);
 995
 996         c->umask = 0002;
 997         c->oom_adjust = 0;
 998         c->oom_adjust_set = false;
 999         c->nice = 0;
1000         c->nice_set = false;
1001         c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);
1002         c->ioprio_set = false;
1003         c->cpu_sched_policy = SCHED_OTHER;
1004         c->cpu_sched_priority = 0;
1005         c->cpu_sched_set = false;
1006         CPU_ZERO(&c->cpu_affinity);
1007         c->cpu_affinity_set = false;
1008         c->timer_slack_ns = 0;
1009         c->timer_slack_ns_set = false;
1010
1011         c->cpu_sched_reset_on_fork = false;
1012         c->non_blocking = false;
1013
1014         c->std_input = 0;
1015         c->std_output = 0;
1016         c->std_error = 0;
1017         c->syslog_priority = LOG_DAEMON|LOG_INFO;
1018
1019         c->secure_bits = 0;
1020         c->capability_bounding_set_drop = 0;
1021 }
1022
1023 void exec_context_done(ExecContext *c) {
1024         unsigned l;
1025
1026         assert(c);
1027
1028         strv_free(c->environment);
1029         c->environment = NULL;
1030
1031         for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {
1032                 free(c->rlimit[l]);
1033                 c->rlimit[l] = NULL;
1034         }
1035
1036         free(c->working_directory);
1037         c->working_directory = NULL;
1038         free(c->root_directory);
1039         c->root_directory = NULL;
1040
1041         free(c->tty_path);
1042         c->tty_path = NULL;
1043
1044         free(c->syslog_identifier);
1045         c->syslog_identifier = NULL;
1046
1047         free(c->user);
1048         c->user = NULL;
1049
1050         free(c->group);
1051         c->group = NULL;
1052
1053         strv_free(c->supplementary_groups);
1054         c->supplementary_groups = NULL;
1055
1056         if (c->capabilities) {
1057                 cap_free(c->capabilities);
1058                 c->capabilities = NULL;
1059         }
1060 }
1061
1062 void exec_command_done(ExecCommand *c) {
1063         assert(c);
1064
1065         free(c->path);
1066         c->path = NULL;
1067
1068         strv_free(c->argv);
1069         c->argv = NULL;
1070 }
1071
1072 void exec_command_done_array(ExecCommand *c, unsigned n) {
1073         unsigned i;
1074
1075         for (i = 0; i < n; i++)
1076                 exec_command_done(c+i);
1077 }
1078
1079 void exec_command_free_list(ExecCommand *c) {
1080         ExecCommand *i;
1081
1082         while ((i = c)) {
1083                 LIST_REMOVE(ExecCommand, command, c, i);
1084                 exec_command_done(i);
1085                 free(i);
1086         }
1087 }
1088
1089 void exec_command_free_array(ExecCommand **c, unsigned n) {
1090         unsigned i;
1091
1092         for (i = 0; i < n; i++) {
1093                 exec_command_free_list(c[i]);
1094                 c[i] = NULL;
1095         }
1096 }
1097
1098 void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
1099         char ** e;
1100         unsigned i;
1101
1102         assert(c);
1103         assert(f);
1104
1105         if (!prefix)
1106                 prefix = "";
1107
1108         fprintf(f,
1109                 "%sUMask: %04o\n"
1110                 "%sWorkingDirectory: %s\n"
1111                 "%sRootDirectory: %s\n"
1112                 "%sNonBlocking: %s\n",
1113                 prefix, c->umask,
1114                 prefix, c->working_directory ? c->working_directory : "/",
1115                 prefix, c->root_directory ? c->root_directory : "/",
1116                 prefix, yes_no(c->non_blocking));
1117
1118         if (c->environment)
1119                 for (e = c->environment; *e; e++)
1120                         fprintf(f, "%sEnvironment: %s\n", prefix, *e);
1121
1122         if (c->nice_set)
1123                 fprintf(f,
1124                         "%sNice: %i\n",
1125                         prefix, c->nice);
1126
1127         if (c->oom_adjust_set)
1128                 fprintf(f,
1129                         "%sOOMAdjust: %i\n",
1130                         prefix, c->oom_adjust);
1131
1132         for (i = 0; i < RLIM_NLIMITS; i++)
1133                 if (c->rlimit[i])
1134                         fprintf(f, "%s%s: %llu\n", prefix, rlimit_to_string(i), (unsigned long long) c->rlimit[i]->rlim_max);
1135
1136         if (c->ioprio_set)
1137                 fprintf(f,
1138                         "%sIOSchedulingClass: %s\n"
1139                         "%sIOPriority: %i\n",
1140                         prefix, ioprio_class_to_string(IOPRIO_PRIO_CLASS(c->ioprio)),
1141                         prefix, (int) IOPRIO_PRIO_DATA(c->ioprio));
1142
1143         if (c->cpu_sched_set)
1144                 fprintf(f,
1145                         "%sCPUSchedulingPolicy: %s\n"
1146                         "%sCPUSchedulingPriority: %i\n"
1147                         "%sCPUSchedulingResetOnFork: %s\n",
1148                         prefix, sched_policy_to_string(c->cpu_sched_policy),
1149                         prefix, c->cpu_sched_priority,
1150                         prefix, yes_no(c->cpu_sched_reset_on_fork));
1151
1152         if (c->cpu_affinity_set) {
1153                 fprintf(f, "%sCPUAffinity:", prefix);
1154                 for (i = 0; i < CPU_SETSIZE; i++)
1155                         if (CPU_ISSET(i, &c->cpu_affinity))
1156                                 fprintf(f, " %i", i);
1157                 fputs("\n", f);
1158         }
1159
1160         if (c->timer_slack_ns_set)
1161                 fprintf(f, "%sTimerSlackNS: %lu\n", prefix, c->timer_slack_ns);
1162
1163         fprintf(f,
1164                 "%sStandardInput: %s\n"
1165                 "%sStandardOutput: %s\n"
1166                 "%sStandardError: %s\n",
1167                 prefix, exec_input_to_string(c->std_input),
1168                 prefix, exec_output_to_string(c->std_output),
1169                 prefix, exec_output_to_string(c->std_error));
1170
1171         if (c->tty_path)
1172                 fprintf(f,
1173                         "%sTTYPath: %s\n",
1174                         prefix, c->tty_path);
1175
1176         if (c->std_output == EXEC_OUTPUT_SYSLOG || c->std_output == EXEC_OUTPUT_KERNEL ||
1177             c->std_error == EXEC_OUTPUT_SYSLOG || c->std_error == EXEC_OUTPUT_KERNEL)
1178                 fprintf(f,
1179                         "%sSyslogFacility: %s\n"
1180                         "%sSyslogLevel: %s\n",
1181                         prefix, log_facility_to_string(LOG_FAC(c->syslog_priority)),
1182                         prefix, log_level_to_string(LOG_PRI(c->syslog_priority)));
1183
1184         if (c->capabilities) {
1185                 char *t;
1186                 if ((t = cap_to_text(c->capabilities, NULL))) {
1187                         fprintf(f, "%sCapabilities: %s\n",
1188                                 prefix, t);
1189                         cap_free(t);
1190                 }
1191         }
1192
1193         if (c->secure_bits)
1194                 fprintf(f, "%sSecure Bits:%s%s%s%s%s%s\n",
1195                         prefix,
1196                         (c->secure_bits & SECURE_KEEP_CAPS) ? " keep-caps" : "",
1197                         (c->secure_bits & SECURE_KEEP_CAPS_LOCKED) ? " keep-caps-locked" : "",
1198                         (c->secure_bits & SECURE_NO_SETUID_FIXUP) ? " no-setuid-fixup" : "",
1199                         (c->secure_bits & SECURE_NO_SETUID_FIXUP_LOCKED) ? " no-setuid-fixup-locked" : "",
1200                         (c->secure_bits & SECURE_NOROOT) ? " noroot" : "",
1201                         (c->secure_bits & SECURE_NOROOT_LOCKED) ? "noroot-locked" : "");
1202
1203         if (c->capability_bounding_set_drop) {
1204                 fprintf(f, "%sCapabilityBoundingSetDrop:", prefix);
1205
1206                 for (i = 0; i <= CAP_LAST_CAP; i++)
1207                         if (c->capability_bounding_set_drop & (1 << i)) {
1208                                 char *t;
1209
1210                                 if ((t = cap_to_name(i))) {
1211                                         fprintf(f, " %s", t);
1212                                         free(t);
1213                                 }
1214                         }
1215
1216                 fputs("\n", f);
1217         }
1218
1219         if (c->user)
1220                 fprintf(f, "%sUser: %s", prefix, c->user);
1221         if (c->group)
1222                 fprintf(f, "%sGroup: %s", prefix, c->group);
1223
1224         if (c->supplementary_groups) {
1225                 char **g;
1226
1227                 fprintf(f, "%sSupplementaryGroups:", prefix);
1228
1229                 STRV_FOREACH(g, c->supplementary_groups)
1230                         fprintf(f, " %s", *g);
1231
1232                 fputs("\n", f);
1233         }
1234 }
1235
1236 void exec_status_fill(ExecStatus *s, pid_t pid, int code, int status) {
1237         assert(s);
1238
1239         s->pid = pid;
1240         s->exit_timestamp = now(CLOCK_REALTIME);
1241
1242         s->code = code;
1243         s->status = status;
1244 }
1245
1246 void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix) {
1247         char buf[FORMAT_TIMESTAMP_MAX];
1248
1249         assert(s);
1250         assert(f);
1251
1252         if (!prefix)
1253                 prefix = "";
1254
1255         if (s->pid <= 0)
1256                 return;
1257
1258         fprintf(f,
1259                 "%sPID: %llu\n",
1260                 prefix, (unsigned long long) s->pid);
1261
1262         if (s->start_timestamp > 0)
1263                 fprintf(f,
1264                         "%sStart Timestamp: %s\n",
1265                         prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp));
1266
1267         if (s->exit_timestamp > 0)
1268                 fprintf(f,
1269                         "%sExit Timestamp: %s\n"
1270                         "%sExit Code: %s\n"
1271                         "%sExit Status: %i\n",
1272                         prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp),
1273                         prefix, sigchld_code_to_string(s->code),
1274                         prefix, s->status);
1275 }
1276
1277 char *exec_command_line(char **argv) {
1278         size_t k;
1279         char *n, *p, **a;
1280         bool first = true;
1281
1282         assert(argv);
1283
1284         k = 1;
1285         STRV_FOREACH(a, argv)
1286                 k += strlen(*a)+3;
1287
1288         if (!(n = new(char, k)))
1289                 return NULL;
1290
1291         p = n;
1292         STRV_FOREACH(a, argv) {
1293
1294                 if (!first)
1295                         *(p++) = ' ';
1296                 else
1297                         first = false;
1298
1299                 if (strpbrk(*a, WHITESPACE)) {
1300                         *(p++) = '\'';
1301                         p = stpcpy(p, *a);
1302                         *(p++) = '\'';
1303                 } else
1304                         p = stpcpy(p, *a);
1305
1306         }
1307
1308         *p = 0;
1309
1310         /* FIXME: this doesn't really handle arguments that have
1311          * spaces and ticks in them */
1312
1313         return n;
1314 }
1315
1316 void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
1317         char *p2;
1318         const char *prefix2;
1319
1320         char *cmd;
1321
1322         assert(c);
1323         assert(f);
1324
1325         if (!prefix)
1326                 prefix = "";
1327         p2 = strappend(prefix, "\t");
1328         prefix2 = p2 ? p2 : prefix;
1329
1330         cmd = exec_command_line(c->argv);
1331
1332         fprintf(f,
1333                 "%sCommand Line: %s\n",
1334                 prefix, cmd ? cmd : strerror(ENOMEM));
1335
1336         free(cmd);
1337
1338         exec_status_dump(&c->exec_status, f, prefix2);
1339
1340         free(p2);
1341 }
1342
1343 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
1344         assert(f);
1345
1346         if (!prefix)
1347                 prefix = "";
1348
1349         LIST_FOREACH(command, c, c)
1350                 exec_command_dump(c, f, prefix);
1351 }
1352
1353 void exec_command_append_list(ExecCommand **l, ExecCommand *e) {
1354         ExecCommand *end;
1355
1356         assert(l);
1357         assert(e);
1358
1359         if (*l) {
1360                 /* It's kinda important that we keep the order here */
1361                 LIST_FIND_TAIL(ExecCommand, command, *l, end);
1362                 LIST_INSERT_AFTER(ExecCommand, command, *l, end, e);
1363         } else
1364               *l = e;
1365 }
1366
1367 int exec_command_set(ExecCommand *c, const char *path, ...) {
1368         va_list ap;
1369         char **l, *p;
1370
1371         assert(c);
1372         assert(path);
1373
1374         va_start(ap, path);
1375         l = strv_new_ap(path, ap);
1376         va_end(ap);
1377
1378         if (!l)
1379                 return -ENOMEM;
1380
1381         if (!(p = strdup(path))) {
1382                 strv_free(l);
1383                 return -ENOMEM;
1384         }
1385
1386         free(c->path);
1387         c->path = p;
1388
1389         strv_free(c->argv);
1390         c->argv = l;
1391
1392         return 0;
1393 }
1394
1395 const char* exit_status_to_string(ExitStatus status) {
1396
1397         /* We cast to int here, so that -Wenum doesn't complain that
1398          * EXIT_SUCCESS/EXIT_FAILURE aren't in the enum */
1399
1400         switch ((int) status) {
1401
1402         case EXIT_SUCCESS:
1403                 return "SUCCESS";
1404
1405         case EXIT_FAILURE:
1406                 return "FAILURE";
1407
1408         case EXIT_INVALIDARGUMENT:
1409                 return "INVALIDARGUMENT";
1410
1411         case EXIT_NOTIMPLEMENTED:
1412                 return "NOTIMPLEMENTED";
1413
1414         case EXIT_NOPERMISSION:
1415                 return "NOPERMISSION";
1416
1417         case EXIT_NOTINSTALLED:
1418                 return "NOTINSSTALLED";
1419
1420         case EXIT_NOTCONFIGURED:
1421                 return "NOTCONFIGURED";
1422
1423         case EXIT_NOTRUNNING:
1424                 return "NOTRUNNING";
1425
1426         case EXIT_CHDIR:
1427                 return "CHDIR";
1428
1429         case EXIT_NICE:
1430                 return "NICE";
1431
1432         case EXIT_FDS:
1433                 return "FDS";
1434
1435         case EXIT_EXEC:
1436                 return "EXEC";
1437
1438         case EXIT_MEMORY:
1439                 return "MEMORY";
1440
1441         case EXIT_LIMITS:
1442                 return "LIMITS";
1443
1444         case EXIT_OOM_ADJUST:
1445                 return "OOM_ADJUST";
1446
1447         case EXIT_SIGNAL_MASK:
1448                 return "SIGNAL_MASK";
1449
1450         case EXIT_STDIN:
1451                 return "STDIN";
1452
1453         case EXIT_STDOUT:
1454                 return "STDOUT";
1455
1456         case EXIT_CHROOT:
1457                 return "CHROOT";
1458
1459         case EXIT_IOPRIO:
1460                 return "IOPRIO";
1461
1462         case EXIT_TIMERSLACK:
1463                 return "TIMERSLACK";
1464
1465         case EXIT_SECUREBITS:
1466                 return "SECUREBITS";
1467
1468         case EXIT_SETSCHEDULER:
1469                 return "SETSCHEDULER";
1470
1471         case EXIT_CPUAFFINITY:
1472                 return "CPUAFFINITY";
1473
1474         case EXIT_GROUP:
1475                 return "GROUP";
1476
1477         case EXIT_USER:
1478                 return "USER";
1479
1480         case EXIT_CAPABILITIES:
1481                 return "CAPABILITIES";
1482
1483         case EXIT_CGROUP:
1484                 return "CGROUP";
1485
1486         case EXIT_SETSID:
1487                 return "SETSID";
1488
1489         case EXIT_CONFIRM:
1490                 return "CONFIRM";
1491
1492         case EXIT_STDERR:
1493                 return "STDERR";
1494
1495         default:
1496                 return NULL;
1497         }
1498 }
1499
1500 static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
1501         [EXEC_INPUT_NULL] = "null",
1502         [EXEC_INPUT_TTY] = "tty",
1503         [EXEC_INPUT_TTY_FORCE] = "tty-force",
1504         [EXEC_INPUT_TTY_FAIL] = "tty-fail"
1505 };
1506
1507 static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
1508         [EXEC_OUTPUT_INHERIT] = "inherit",
1509         [EXEC_OUTPUT_NULL] = "null",
1510         [EXEC_OUTPUT_TTY] = "tty",
1511         [EXEC_OUTPUT_SYSLOG] = "syslog",
1512         [EXEC_OUTPUT_KERNEL] = "kernel"
1513 };
1514
1515 DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);
1516
1517 DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);