src/core/execute.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   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 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 <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 #include <sys/mount.h>
  38 #include <linux/fs.h>
  39 #include <linux/oom.h>
  40 #include <sys/poll.h>
  41 #include <linux/seccomp-bpf.h>
  42 #include <glob.h>
  43 #include <libgen.h>
  44
  45 #ifdef HAVE_PAM
  46 #include <security/pam_appl.h>
  47 #endif
  48
  49 #include "execute.h"
  50 #include "strv.h"
  51 #include "macro.h"
  52 #include "capability.h"
  53 #include "util.h"
  54 #include "log.h"
  55 #include "sd-messages.h"
  56 #include "ioprio.h"
  57 #include "securebits.h"
  58 #include "cgroup.h"
  59 #include "namespace.h"
  60 #include "tcpwrap.h"
  61 #include "exit-status.h"
  62 #include "missing.h"
  63 #include "utmp-wtmp.h"
  64 #include "def.h"
  65 #include "loopback-setup.h"
  66 #include "path-util.h"
  67 #include "syscall-list.h"
  68 #include "env-util.h"
  69 #include "fileio.h"
  70
  71 #define IDLE_TIMEOUT_USEC (5*USEC_PER_SEC)
  72
  73 /* This assumes there is a 'tty' group */
  74 #define TTY_MODE 0620
  75
  76 static int shift_fds(int fds[], unsigned n_fds) {
  77         int start, restart_from;
  78
  79         if (n_fds <= 0)
  80                 return 0;
  81
  82         /* Modifies the fds array! (sorts it) */
  83
  84         assert(fds);
  85
  86         start = 0;
  87         for (;;) {
  88                 int i;
  89
  90                 restart_from = -1;
  91
  92                 for (i = start; i < (int) n_fds; i++) {
  93                         int nfd;
  94
  95                         /* Already at right index? */
  96                         if (fds[i] == i+3)
  97                                 continue;
  98
  99                         if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)
 100                                 return -errno;
 101
 102                         close_nointr_nofail(fds[i]);
 103                         fds[i] = nfd;
 104
 105                         /* Hmm, the fd we wanted isn't free? Then
 106                          * let's remember that and try again from here*/
 107                         if (nfd != i+3 && restart_from < 0)
 108                                 restart_from = i;
 109                 }
 110
 111                 if (restart_from < 0)
 112                         break;
 113
 114                 start = restart_from;
 115         }
 116
 117         return 0;
 118 }
 119
 120 static int flags_fds(const int fds[], unsigned n_fds, bool nonblock) {
 121         unsigned i;
 122         int r;
 123
 124         if (n_fds <= 0)
 125                 return 0;
 126
 127         assert(fds);
 128
 129         /* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags */
 130
 131         for (i = 0; i < n_fds; i++) {
 132
 133                 if ((r = fd_nonblock(fds[i], nonblock)) < 0)
 134                         return r;
 135
 136                 /* We unconditionally drop FD_CLOEXEC from the fds,
 137                  * since after all we want to pass these fds to our
 138                  * children */
 139
 140                 if ((r = fd_cloexec(fds[i], false)) < 0)
 141                         return r;
 142         }
 143
 144         return 0;
 145 }
 146
 147 static const char *tty_path(const ExecContext *context) {
 148         assert(context);
 149
 150         if (context->tty_path)
 151                 return context->tty_path;
 152
 153         return "/dev/console";
 154 }
 155
 156 void exec_context_tty_reset(const ExecContext *context) {
 157         assert(context);
 158
 159         if (context->tty_vhangup)
 160                 terminal_vhangup(tty_path(context));
 161
 162         if (context->tty_reset)
 163                 reset_terminal(tty_path(context));
 164
 165         if (context->tty_vt_disallocate && context->tty_path)
 166                 vt_disallocate(context->tty_path);
 167 }
 168
 169 static bool is_terminal_output(ExecOutput o) {
 170         return
 171                 o == EXEC_OUTPUT_TTY ||
 172                 o == EXEC_OUTPUT_SYSLOG_AND_CONSOLE ||
 173                 o == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
 174                 o == EXEC_OUTPUT_JOURNAL_AND_CONSOLE;
 175 }
 176
 177 void exec_context_serialize(const ExecContext *context, Unit *u, FILE *f) {
 178         assert(context);
 179         assert(u);
 180         assert(f);
 181
 182         if (context->tmp_dir)
 183                 unit_serialize_item(u, f, "tmp-dir", context->tmp_dir);
 184
 185         if (context->var_tmp_dir)
 186                 unit_serialize_item(u, f, "var-tmp-dir", context->var_tmp_dir);
 187 }
 188
 189 static int open_null_as(int flags, int nfd) {
 190         int fd, r;
 191
 192         assert(nfd >= 0);
 193
 194         if ((fd = open("/dev/null", flags|O_NOCTTY)) < 0)
 195                 return -errno;
 196
 197         if (fd != nfd) {
 198                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 199                 close_nointr_nofail(fd);
 200         } else
 201                 r = nfd;
 202
 203         return r;
 204 }
 205
 206 static int connect_logger_as(const ExecContext *context, ExecOutput output, const char *ident, const char *unit_id, int nfd) {
 207         int fd, r;
 208         union sockaddr_union sa = {
 209                 .un.sun_family = AF_UNIX,
 210                 .un.sun_path = "/run/systemd/journal/stdout",
 211         };
 212
 213         assert(context);
 214         assert(output < _EXEC_OUTPUT_MAX);
 215         assert(ident);
 216         assert(nfd >= 0);
 217
 218         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 219         if (fd < 0)
 220                 return -errno;
 221
 222         r = connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path));
 223         if (r < 0) {
 224                 close_nointr_nofail(fd);
 225                 return -errno;
 226         }
 227
 228         if (shutdown(fd, SHUT_RD) < 0) {
 229                 close_nointr_nofail(fd);
 230                 return -errno;
 231         }
 232
 233         dprintf(fd,
 234                 "%s\n"
 235                 "%s\n"
 236                 "%i\n"
 237                 "%i\n"
 238                 "%i\n"
 239                 "%i\n"
 240                 "%i\n",
 241                 context->syslog_identifier ? context->syslog_identifier : ident,
 242                 unit_id,
 243                 context->syslog_priority,
 244                 !!context->syslog_level_prefix,
 245                 output == EXEC_OUTPUT_SYSLOG || output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
 246                 output == EXEC_OUTPUT_KMSG || output == EXEC_OUTPUT_KMSG_AND_CONSOLE,
 247                 is_terminal_output(output));
 248
 249         if (fd != nfd) {
 250                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 251                 close_nointr_nofail(fd);
 252         } else
 253                 r = nfd;
 254
 255         return r;
 256 }
 257 static int open_terminal_as(const char *path, mode_t mode, int nfd) {
 258         int fd, r;
 259
 260         assert(path);
 261         assert(nfd >= 0);
 262
 263         if ((fd = open_terminal(path, mode | O_NOCTTY)) < 0)
 264                 return fd;
 265
 266         if (fd != nfd) {
 267                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 268                 close_nointr_nofail(fd);
 269         } else
 270                 r = nfd;
 271
 272         return r;
 273 }
 274
 275 static bool is_terminal_input(ExecInput i) {
 276         return
 277                 i == EXEC_INPUT_TTY ||
 278                 i == EXEC_INPUT_TTY_FORCE ||
 279                 i == EXEC_INPUT_TTY_FAIL;
 280 }
 281
 282 static int fixup_input(ExecInput std_input, int socket_fd, bool apply_tty_stdin) {
 283
 284         if (is_terminal_input(std_input) && !apply_tty_stdin)
 285                 return EXEC_INPUT_NULL;
 286
 287         if (std_input == EXEC_INPUT_SOCKET && socket_fd < 0)
 288                 return EXEC_INPUT_NULL;
 289
 290         return std_input;
 291 }
 292
 293 static int fixup_output(ExecOutput std_output, int socket_fd) {
 294
 295         if (std_output == EXEC_OUTPUT_SOCKET && socket_fd < 0)
 296                 return EXEC_OUTPUT_INHERIT;
 297
 298         return std_output;
 299 }
 300
 301 static int setup_input(const ExecContext *context, int socket_fd, bool apply_tty_stdin) {
 302         ExecInput i;
 303
 304         assert(context);
 305
 306         i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);
 307
 308         switch (i) {
 309
 310         case EXEC_INPUT_NULL:
 311                 return open_null_as(O_RDONLY, STDIN_FILENO);
 312
 313         case EXEC_INPUT_TTY:
 314         case EXEC_INPUT_TTY_FORCE:
 315         case EXEC_INPUT_TTY_FAIL: {
 316                 int fd, r;
 317
 318                 if ((fd = acquire_terminal(
 319                                      tty_path(context),
 320                                      i == EXEC_INPUT_TTY_FAIL,
 321                                      i == EXEC_INPUT_TTY_FORCE,
 322                                      false,
 323                                      (usec_t) -1)) < 0)
 324                         return fd;
 325
 326                 if (fd != STDIN_FILENO) {
 327                         r = dup2(fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 328                         close_nointr_nofail(fd);
 329                 } else
 330                         r = STDIN_FILENO;
 331
 332                 return r;
 333         }
 334
 335         case EXEC_INPUT_SOCKET:
 336                 return dup2(socket_fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 337
 338         default:
 339                 assert_not_reached("Unknown input type");
 340         }
 341 }
 342
 343 static int setup_output(const ExecContext *context, int fileno, int socket_fd, const char *ident, const char *unit_id, bool apply_tty_stdin) {
 344         ExecOutput o;
 345         ExecInput i;
 346         int r;
 347
 348         assert(context);
 349         assert(ident);
 350
 351         i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);
 352         o = fixup_output(context->std_output, socket_fd);
 353
 354         if (fileno == STDERR_FILENO) {
 355                 ExecOutput e;
 356                 e = fixup_output(context->std_error, socket_fd);
 357
 358                 /* This expects the input and output are already set up */
 359
 360                 /* Don't change the stderr file descriptor if we inherit all
 361                  * the way and are not on a tty */
 362                 if (e == EXEC_OUTPUT_INHERIT &&
 363                     o == EXEC_OUTPUT_INHERIT &&
 364                     i == EXEC_INPUT_NULL &&
 365                     !is_terminal_input(context->std_input) &&
 366                     getppid () != 1)
 367                         return fileno;
 368
 369                 /* Duplicate from stdout if possible */
 370                 if (e == o || e == EXEC_OUTPUT_INHERIT)
 371                         return dup2(STDOUT_FILENO, fileno) < 0 ? -errno : fileno;
 372
 373                 o = e;
 374
 375         } else if (o == EXEC_OUTPUT_INHERIT) {
 376                 /* If input got downgraded, inherit the original value */
 377                 if (i == EXEC_INPUT_NULL && is_terminal_input(context->std_input))
 378                         return open_terminal_as(tty_path(context), O_WRONLY, fileno);
 379
 380                 /* If the input is connected to anything that's not a /dev/null, inherit that... */
 381                 if (i != EXEC_INPUT_NULL)
 382                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 383
 384                 /* If we are not started from PID 1 we just inherit STDOUT from our parent process. */
 385                 if (getppid() != 1)
 386                         return fileno;
 387
 388                 /* We need to open /dev/null here anew, to get the right access mode. */
 389                 return open_null_as(O_WRONLY, fileno);
 390         }
 391
 392         switch (o) {
 393
 394         case EXEC_OUTPUT_NULL:
 395                 return open_null_as(O_WRONLY, fileno);
 396
 397         case EXEC_OUTPUT_TTY:
 398                 if (is_terminal_input(i))
 399                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 400
 401                 /* We don't reset the terminal if this is just about output */
 402                 return open_terminal_as(tty_path(context), O_WRONLY, fileno);
 403
 404         case EXEC_OUTPUT_SYSLOG:
 405         case EXEC_OUTPUT_SYSLOG_AND_CONSOLE:
 406         case EXEC_OUTPUT_KMSG:
 407         case EXEC_OUTPUT_KMSG_AND_CONSOLE:
 408         case EXEC_OUTPUT_JOURNAL:
 409         case EXEC_OUTPUT_JOURNAL_AND_CONSOLE:
 410                 r = connect_logger_as(context, o, ident, unit_id, fileno);
 411                 if (r < 0) {
 412                         log_struct_unit(LOG_CRIT, unit_id,
 413                                 "MESSAGE=Failed to connect std%s of %s to the journal socket: %s",
 414                                 fileno == STDOUT_FILENO ? "out" : "err",
 415                                 unit_id, strerror(-r),
 416                                 "ERRNO=%d", -r,
 417                                 NULL);
 418                         r = open_null_as(O_WRONLY, fileno);
 419                 }
 420                 return r;
 421
 422         case EXEC_OUTPUT_SOCKET:
 423                 assert(socket_fd >= 0);
 424                 return dup2(socket_fd, fileno) < 0 ? -errno : fileno;
 425
 426         default:
 427                 assert_not_reached("Unknown error type");
 428         }
 429 }
 430
 431 static int chown_terminal(int fd, uid_t uid) {
 432         struct stat st;
 433
 434         assert(fd >= 0);
 435
 436         /* This might fail. What matters are the results. */
 437         (void) fchown(fd, uid, -1);
 438         (void) fchmod(fd, TTY_MODE);
 439
 440         if (fstat(fd, &st) < 0)
 441                 return -errno;
 442
 443         if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE)
 444                 return -EPERM;
 445
 446         return 0;
 447 }
 448
 449 static int setup_confirm_stdio(int *_saved_stdin,
 450                                int *_saved_stdout) {
 451         int fd = -1, saved_stdin, saved_stdout = -1, r;
 452
 453         assert(_saved_stdin);
 454         assert(_saved_stdout);
 455
 456         saved_stdin = fcntl(STDIN_FILENO, F_DUPFD, 3);
 457         if (saved_stdin < 0)
 458                 return -errno;
 459
 460         saved_stdout = fcntl(STDOUT_FILENO, F_DUPFD, 3);
 461         if (saved_stdout < 0) {
 462                 r = errno;
 463                 goto fail;
 464         }
 465
 466         fd = acquire_terminal(
 467                         "/dev/console",
 468                         false,
 469                         false,
 470                         false,
 471                         DEFAULT_CONFIRM_USEC);
 472         if (fd < 0) {
 473                 r = fd;
 474                 goto fail;
 475         }
 476
 477         r = chown_terminal(fd, getuid());
 478         if (r < 0)
 479                 goto fail;
 480
 481         if (dup2(fd, STDIN_FILENO) < 0) {
 482                 r = -errno;
 483                 goto fail;
 484         }
 485
 486         if (dup2(fd, STDOUT_FILENO) < 0) {
 487                 r = -errno;
 488                 goto fail;
 489         }
 490
 491         if (fd >= 2)
 492                 close_nointr_nofail(fd);
 493
 494         *_saved_stdin = saved_stdin;
 495         *_saved_stdout = saved_stdout;
 496
 497         return 0;
 498
 499 fail:
 500         if (saved_stdout >= 0)
 501                 close_nointr_nofail(saved_stdout);
 502
 503         if (saved_stdin >= 0)
 504                 close_nointr_nofail(saved_stdin);
 505
 506         if (fd >= 0)
 507                 close_nointr_nofail(fd);
 508
 509         return r;
 510 }
 511
 512 static int write_confirm_message(const char *format, ...) {
 513         int fd;
 514         va_list ap;
 515
 516         assert(format);
 517
 518         fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
 519         if (fd < 0)
 520                 return fd;
 521
 522         va_start(ap, format);
 523         vdprintf(fd, format, ap);
 524         va_end(ap);
 525
 526         close_nointr_nofail(fd);
 527
 528         return 0;
 529 }
 530
 531 static int restore_confirm_stdio(int *saved_stdin,
 532                                  int *saved_stdout) {
 533
 534         int r = 0;
 535
 536         assert(saved_stdin);
 537         assert(saved_stdout);
 538
 539         release_terminal();
 540
 541         if (*saved_stdin >= 0)
 542                 if (dup2(*saved_stdin, STDIN_FILENO) < 0)
 543                         r = -errno;
 544
 545         if (*saved_stdout >= 0)
 546                 if (dup2(*saved_stdout, STDOUT_FILENO) < 0)
 547                         r = -errno;
 548
 549         if (*saved_stdin >= 0)
 550                 close_nointr_nofail(*saved_stdin);
 551
 552         if (*saved_stdout >= 0)
 553                 close_nointr_nofail(*saved_stdout);
 554
 555         return r;
 556 }
 557
 558 static int ask_for_confirmation(char *response, char **argv) {
 559         int saved_stdout = -1, saved_stdin = -1, r;
 560         char *line;
 561
 562         r = setup_confirm_stdio(&saved_stdin, &saved_stdout);
 563         if (r < 0)
 564                 return r;
 565
 566         line = exec_command_line(argv);
 567         if (!line)
 568                 return -ENOMEM;
 569
 570         r = ask(response, "yns", "Execute %s? [Yes, No, Skip] ", line);
 571         free(line);
 572
 573         restore_confirm_stdio(&saved_stdin, &saved_stdout);
 574
 575         return r;
 576 }
 577
 578 static int enforce_groups(const ExecContext *context, const char *username, gid_t gid) {
 579         bool keep_groups = false;
 580         int r;
 581
 582         assert(context);
 583
 584         /* Lookup and set GID and supplementary group list. Here too
 585          * we avoid NSS lookups for gid=0. */
 586
 587         if (context->group || username) {
 588
 589                 if (context->group) {
 590                         const char *g = context->group;
 591
 592                         if ((r = get_group_creds(&g, &gid)) < 0)
 593                                 return r;
 594                 }
 595
 596                 /* First step, initialize groups from /etc/groups */
 597                 if (username && gid != 0) {
 598                         if (initgroups(username, gid) < 0)
 599                                 return -errno;
 600
 601                         keep_groups = true;
 602                 }
 603
 604                 /* Second step, set our gids */
 605                 if (setresgid(gid, gid, gid) < 0)
 606                         return -errno;
 607         }
 608
 609         if (context->supplementary_groups) {
 610                 int ngroups_max, k;
 611                 gid_t *gids;
 612                 char **i;
 613
 614                 /* Final step, initialize any manually set supplementary groups */
 615                 assert_se((ngroups_max = (int) sysconf(_SC_NGROUPS_MAX)) > 0);
 616
 617                 if (!(gids = new(gid_t, ngroups_max)))
 618                         return -ENOMEM;
 619
 620                 if (keep_groups) {
 621                         if ((k = getgroups(ngroups_max, gids)) < 0) {
 622                                 free(gids);
 623                                 return -errno;
 624                         }
 625                 } else
 626                         k = 0;
 627
 628                 STRV_FOREACH(i, context->supplementary_groups) {
 629                         const char *g;
 630
 631                         if (k >= ngroups_max) {
 632                                 free(gids);
 633                                 return -E2BIG;
 634                         }
 635
 636                         g = *i;
 637                         r = get_group_creds(&g, gids+k);
 638                         if (r < 0) {
 639                                 free(gids);
 640                                 return r;
 641                         }
 642
 643                         k++;
 644                 }
 645
 646                 if (setgroups(k, gids) < 0) {
 647                         free(gids);
 648                         return -errno;
 649                 }
 650
 651                 free(gids);
 652         }
 653
 654         return 0;
 655 }
 656
 657 static int enforce_user(const ExecContext *context, uid_t uid) {
 658         int r;
 659         assert(context);
 660
 661         /* Sets (but doesn't lookup) the uid and make sure we keep the
 662          * capabilities while doing so. */
 663
 664         if (context->capabilities) {
 665                 cap_t d;
 666                 static const cap_value_t bits[] = {
 667                         CAP_SETUID,   /* Necessary so that we can run setresuid() below */
 668                         CAP_SETPCAP   /* Necessary so that we can set PR_SET_SECUREBITS later on */
 669                 };
 670
 671                 /* First step: If we need to keep capabilities but
 672                  * drop privileges we need to make sure we keep our
 673                  * caps, while we drop privileges. */
 674                 if (uid != 0) {
 675                         int sb = context->secure_bits | 1<<SECURE_KEEP_CAPS;
 676
 677                         if (prctl(PR_GET_SECUREBITS) != sb)
 678                                 if (prctl(PR_SET_SECUREBITS, sb) < 0)
 679                                         return -errno;
 680                 }
 681
 682                 /* Second step: set the capabilities. This will reduce
 683                  * the capabilities to the minimum we need. */
 684
 685                 if (!(d = cap_dup(context->capabilities)))
 686                         return -errno;
 687
 688                 if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 ||
 689                     cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0) {
 690                         r = -errno;
 691                         cap_free(d);
 692                         return r;
 693                 }
 694
 695                 if (cap_set_proc(d) < 0) {
 696                         r = -errno;
 697                         cap_free(d);
 698                         return r;
 699                 }
 700
 701                 cap_free(d);
 702         }
 703
 704         /* Third step: actually set the uids */
 705         if (setresuid(uid, uid, uid) < 0)
 706                 return -errno;
 707
 708         /* At this point we should have all necessary capabilities but
 709            are otherwise a normal user. However, the caps might got
 710            corrupted due to the setresuid() so we need clean them up
 711            later. This is done outside of this call. */
 712
 713         return 0;
 714 }
 715
 716 #ifdef HAVE_PAM
 717
 718 static int null_conv(
 719                 int num_msg,
 720                 const struct pam_message **msg,
 721                 struct pam_response **resp,
 722                 void *appdata_ptr) {
 723
 724         /* We don't support conversations */
 725
 726         return PAM_CONV_ERR;
 727 }
 728
 729 static int setup_pam(
 730                 const char *name,
 731                 const char *user,
 732                 uid_t uid,
 733                 const char *tty,
 734                 char ***pam_env,
 735                 int fds[], unsigned n_fds) {
 736
 737         static const struct pam_conv conv = {
 738                 .conv = null_conv,
 739                 .appdata_ptr = NULL
 740         };
 741
 742         pam_handle_t *handle = NULL;
 743         sigset_t ss, old_ss;
 744         int pam_code = PAM_SUCCESS;
 745         int err;
 746         char **e = NULL;
 747         bool close_session = false;
 748         pid_t pam_pid = 0, parent_pid;
 749
 750         assert(name);
 751         assert(user);
 752         assert(pam_env);
 753
 754         /* We set up PAM in the parent process, then fork. The child
 755          * will then stay around until killed via PR_GET_PDEATHSIG or
 756          * systemd via the cgroup logic. It will then remove the PAM
 757          * session again. The parent process will exec() the actual
 758          * daemon. We do things this way to ensure that the main PID
 759          * of the daemon is the one we initially fork()ed. */
 760
 761         if ((pam_code = pam_start(name, user, &conv, &handle)) != PAM_SUCCESS) {
 762                 handle = NULL;
 763                 goto fail;
 764         }
 765
 766         if (tty)
 767                 if ((pam_code = pam_set_item(handle, PAM_TTY, tty)) != PAM_SUCCESS)
 768                         goto fail;
 769
 770         if ((pam_code = pam_acct_mgmt(handle, PAM_SILENT)) != PAM_SUCCESS)
 771                 goto fail;
 772
 773         if ((pam_code = pam_open_session(handle, PAM_SILENT)) != PAM_SUCCESS)
 774                 goto fail;
 775
 776         close_session = true;
 777
 778         if ((!(e = pam_getenvlist(handle)))) {
 779                 pam_code = PAM_BUF_ERR;
 780                 goto fail;
 781         }
 782
 783         /* Block SIGTERM, so that we know that it won't get lost in
 784          * the child */
 785         if (sigemptyset(&ss) < 0 ||
 786             sigaddset(&ss, SIGTERM) < 0 ||
 787             sigprocmask(SIG_BLOCK, &ss, &old_ss) < 0)
 788                 goto fail;
 789
 790         parent_pid = getpid();
 791
 792         if ((pam_pid = fork()) < 0)
 793                 goto fail;
 794
 795         if (pam_pid == 0) {
 796                 int sig;
 797                 int r = EXIT_PAM;
 798
 799                 /* The child's job is to reset the PAM session on
 800                  * termination */
 801
 802                 /* This string must fit in 10 chars (i.e. the length
 803                  * of "/sbin/init"), to look pretty in /bin/ps */
 804                 rename_process("(sd-pam)");
 805
 806                 /* Make sure we don't keep open the passed fds in this
 807                 child. We assume that otherwise only those fds are
 808                 open here that have been opened by PAM. */
 809                 close_many(fds, n_fds);
 810
 811                 /* Drop privileges - we don't need any to pam_close_session
 812                  * and this will make PR_SET_PDEATHSIG work in most cases.
 813                  * If this fails, ignore the error - but expect sd-pam threads
 814                  * to fail to exit normally */
 815                 if (setresuid(uid, uid, uid) < 0)
 816                         log_error("Error: Failed to setresuid() in sd-pam: %s", strerror(-r));
 817
 818                 /* Wait until our parent died. This will only work if
 819                  * the above setresuid() succeeds, otherwise the kernel
 820                  * will not allow unprivileged parents kill their privileged
 821                  * children this way. We rely on the control groups kill logic
 822                  * to do the rest for us. */
 823                 if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
 824                         goto child_finish;
 825
 826                 /* Check if our parent process might already have
 827                  * died? */
 828                 if (getppid() == parent_pid) {
 829                         for (;;) {
 830                                 if (sigwait(&ss, &sig) < 0) {
 831                                         if (errno == EINTR)
 832                                                 continue;
 833
 834                                         goto child_finish;
 835                                 }
 836
 837                                 assert(sig == SIGTERM);
 838                                 break;
 839                         }
 840                 }
 841
 842                 /* If our parent died we'll end the session */
 843                 if (getppid() != parent_pid)
 844                         if ((pam_code = pam_close_session(handle, PAM_DATA_SILENT)) != PAM_SUCCESS)
 845                                 goto child_finish;
 846
 847                 r = 0;
 848
 849         child_finish:
 850                 pam_end(handle, pam_code | PAM_DATA_SILENT);
 851                 _exit(r);
 852         }
 853
 854         /* If the child was forked off successfully it will do all the
 855          * cleanups, so forget about the handle here. */
 856         handle = NULL;
 857
 858         /* Unblock SIGTERM again in the parent */
 859         if (sigprocmask(SIG_SETMASK, &old_ss, NULL) < 0)
 860                 goto fail;
 861
 862         /* We close the log explicitly here, since the PAM modules
 863          * might have opened it, but we don't want this fd around. */
 864         closelog();
 865
 866         *pam_env = e;
 867         e = NULL;
 868
 869         return 0;
 870
 871 fail:
 872         if (pam_code != PAM_SUCCESS)
 873                 err = -EPERM;  /* PAM errors do not map to errno */
 874         else
 875                 err = -errno;
 876
 877         if (handle) {
 878                 if (close_session)
 879                         pam_code = pam_close_session(handle, PAM_DATA_SILENT);
 880
 881                 pam_end(handle, pam_code | PAM_DATA_SILENT);
 882         }
 883
 884         strv_free(e);
 885
 886         closelog();
 887
 888         if (pam_pid > 1) {
 889                 kill(pam_pid, SIGTERM);
 890                 kill(pam_pid, SIGCONT);
 891         }
 892
 893         return err;
 894 }
 895 #endif
 896
 897 static void rename_process_from_path(const char *path) {
 898         char process_name[11];
 899         const char *p;
 900         size_t l;
 901
 902         /* This resulting string must fit in 10 chars (i.e. the length
 903          * of "/sbin/init") to look pretty in /bin/ps */
 904
 905         p = path_get_file_name(path);
 906         if (isempty(p)) {
 907                 rename_process("(...)");
 908                 return;
 909         }
 910
 911         l = strlen(p);
 912         if (l > 8) {
 913                 /* The end of the process name is usually more
 914                  * interesting, since the first bit might just be
 915                  * "systemd-" */
 916                 p = p + l - 8;
 917                 l = 8;
 918         }
 919
 920         process_name[0] = '(';
 921         memcpy(process_name+1, p, l);
 922         process_name[1+l] = ')';
 923         process_name[1+l+1] = 0;
 924
 925         rename_process(process_name);
 926 }
 927
 928 static int apply_seccomp(uint32_t *syscall_filter) {
 929         static const struct sock_filter header[] = {
 930                 VALIDATE_ARCHITECTURE,
 931                 EXAMINE_SYSCALL
 932         };
 933         static const struct sock_filter footer[] = {
 934                 _KILL_PROCESS
 935         };
 936
 937         int i;
 938         unsigned n;
 939         struct sock_filter *f;
 940         struct sock_fprog prog = {};
 941
 942         assert(syscall_filter);
 943
 944         /* First: count the syscalls to check for */
 945         for (i = 0, n = 0; i < syscall_max(); i++)
 946                 if (syscall_filter[i >> 4] & (1 << (i & 31)))
 947                         n++;
 948
 949         /* Second: build the filter program from a header the syscall
 950          * matches and the footer */
 951         f = alloca(sizeof(struct sock_filter) * (ELEMENTSOF(header) + 2*n + ELEMENTSOF(footer)));
 952         memcpy(f, header, sizeof(header));
 953
 954         for (i = 0, n = 0; i < syscall_max(); i++)
 955                 if (syscall_filter[i >> 4] & (1 << (i & 31))) {
 956                         struct sock_filter item[] = {
 957                                 BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, INDEX_TO_SYSCALL(i), 0, 1),
 958                                 BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW)
 959                         };
 960
 961                         assert_cc(ELEMENTSOF(item) == 2);
 962
 963                         f[ELEMENTSOF(header) + 2*n]  = item[0];
 964                         f[ELEMENTSOF(header) + 2*n+1] = item[1];
 965
 966                         n++;
 967                 }
 968
 969         memcpy(f + (ELEMENTSOF(header) + 2*n), footer, sizeof(footer));
 970
 971         /* Third: install the filter */
 972         prog.len = ELEMENTSOF(header) + ELEMENTSOF(footer) + 2*n;
 973         prog.filter = f;
 974         if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog) < 0)
 975                 return -errno;
 976
 977         return 0;
 978 }
 979
 980 int exec_spawn(ExecCommand *command,
 981                char **argv,
 982                ExecContext *context,
 983                int fds[], unsigned n_fds,
 984                char **environment,
 985                bool apply_permissions,
 986                bool apply_chroot,
 987                bool apply_tty_stdin,
 988                bool confirm_spawn,
 989                CGroupBonding *cgroup_bondings,
 990                CGroupAttribute *cgroup_attributes,
 991                const char *cgroup_suffix,
 992                const char *unit_id,
 993                int idle_pipe[2],
 994                pid_t *ret) {
 995
 996         pid_t pid;
 997         int r;
 998         char *line;
 999         int socket_fd;
1000         char _cleanup_strv_free_ **files_env = NULL;
1001
1002         assert(command);
1003         assert(context);
1004         assert(ret);
1005         assert(fds || n_fds <= 0);
1006
1007         if (context->std_input == EXEC_INPUT_SOCKET ||
1008             context->std_output == EXEC_OUTPUT_SOCKET ||
1009             context->std_error == EXEC_OUTPUT_SOCKET) {
1010
1011                 if (n_fds != 1)
1012                         return -EINVAL;
1013
1014                 socket_fd = fds[0];
1015
1016                 fds = NULL;
1017                 n_fds = 0;
1018         } else
1019                 socket_fd = -1;
1020
1021         r = exec_context_load_environment(context, &files_env);
1022         if (r < 0) {
1023                 log_struct_unit(LOG_ERR,
1024                            unit_id,
1025                            "MESSAGE=Failed to load environment files: %s", strerror(-r),
1026                            "ERRNO=%d", -r,
1027                            NULL);
1028                 return r;
1029         }
1030
1031         if (!argv)
1032                 argv = command->argv;
1033
1034         line = exec_command_line(argv);
1035         if (!line)
1036                 return log_oom();
1037
1038         log_struct_unit(LOG_DEBUG,
1039                    unit_id,
1040                    "MESSAGE=About to execute %s", line,
1041                    NULL);
1042         free(line);
1043
1044         r = cgroup_bonding_realize_list(cgroup_bondings);
1045         if (r < 0)
1046                 return r;
1047
1048         /* We must initialize the attributes in the parent, before we
1049         fork, because we really need them initialized before making
1050         the process a member of the group (which we do in both the
1051         child and the parent), and we cannot really apply them twice
1052         (due to 'append' style attributes) */
1053         cgroup_attribute_apply_list(cgroup_attributes, cgroup_bondings);
1054
1055         if (context->private_tmp && !context->tmp_dir && !context->var_tmp_dir) {
1056                 r = setup_tmpdirs(&context->tmp_dir, &context->var_tmp_dir);
1057                 if (r < 0)
1058                         return r;
1059         }
1060
1061         pid = fork();
1062         if (pid < 0)
1063                 return -errno;
1064
1065         if (pid == 0) {
1066                 int i, err;
1067                 sigset_t ss;
1068                 const char *username = NULL, *home = NULL;
1069                 uid_t uid = (uid_t) -1;
1070                 gid_t gid = (gid_t) -1;
1071                 char _cleanup_strv_free_ **our_env = NULL, **pam_env = NULL,
1072                         **final_env = NULL, **final_argv = NULL;
1073                 unsigned n_env = 0;
1074                 bool set_access = false;
1075
1076                 /* child */
1077
1078                 rename_process_from_path(command->path);
1079
1080                 /* We reset exactly these signals, since they are the
1081                  * only ones we set to SIG_IGN in the main daemon. All
1082                  * others we leave untouched because we set them to
1083                  * SIG_DFL or a valid handler initially, both of which
1084                  * will be demoted to SIG_DFL. */
1085                 default_signals(SIGNALS_CRASH_HANDLER,
1086                                 SIGNALS_IGNORE, -1);
1087
1088                 if (context->ignore_sigpipe)
1089                         ignore_signals(SIGPIPE, -1);
1090
1091                 assert_se(sigemptyset(&ss) == 0);
1092                 if (sigprocmask(SIG_SETMASK, &ss, NULL) < 0) {
1093                         err = -errno;
1094                         r = EXIT_SIGNAL_MASK;
1095                         goto fail_child;
1096                 }
1097
1098                 if (idle_pipe) {
1099                         if (idle_pipe[1] >= 0)
1100                                 close_nointr_nofail(idle_pipe[1]);
1101                         if (idle_pipe[0] >= 0) {
1102                                 fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT_USEC);
1103                                 close_nointr_nofail(idle_pipe[0]);
1104                         }
1105                 }
1106
1107                 /* Close sockets very early to make sure we don't
1108                  * block init reexecution because it cannot bind its
1109                  * sockets */
1110                 log_forget_fds();
1111                 err = close_all_fds(socket_fd >= 0 ? &socket_fd : fds,
1112                                            socket_fd >= 0 ? 1 : n_fds);
1113                 if (err < 0) {
1114                         r = EXIT_FDS;
1115                         goto fail_child;
1116                 }
1117
1118                 if (!context->same_pgrp)
1119                         if (setsid() < 0) {
1120                                 err = -errno;
1121                                 r = EXIT_SETSID;
1122                                 goto fail_child;
1123                         }
1124
1125                 if (context->tcpwrap_name) {
1126                         if (socket_fd >= 0)
1127                                 if (!socket_tcpwrap(socket_fd, context->tcpwrap_name)) {
1128                                         err = -EACCES;
1129                                         r = EXIT_TCPWRAP;
1130                                         goto fail_child;
1131                                 }
1132
1133                         for (i = 0; i < (int) n_fds; i++) {
1134                                 if (!socket_tcpwrap(fds[i], context->tcpwrap_name)) {
1135                                         err = -EACCES;
1136                                         r = EXIT_TCPWRAP;
1137                                         goto fail_child;
1138                                 }
1139                         }
1140                 }
1141
1142                 exec_context_tty_reset(context);
1143
1144                 if (confirm_spawn) {
1145                         char response;
1146
1147                         err = ask_for_confirmation(&response, argv);
1148                         if (err == -ETIMEDOUT)
1149                                 write_confirm_message("Confirmation question timed out, assuming positive response.\n");
1150                         else if (err < 0)
1151                                 write_confirm_message("Couldn't ask confirmation question, assuming positive response: %s\n", strerror(-err));
1152                         else if (response == 's') {
1153                                 write_confirm_message("Skipping execution.\n");
1154                                 err = -ECANCELED;
1155                                 r = EXIT_CONFIRM;
1156                                 goto fail_child;
1157                         } else if (response == 'n') {
1158                                 write_confirm_message("Failing execution.\n");
1159                                 err = r = 0;
1160                                 goto fail_child;
1161                         }
1162                 }
1163
1164                 /* If a socket is connected to STDIN/STDOUT/STDERR, we
1165                  * must sure to drop O_NONBLOCK */
1166                 if (socket_fd >= 0)
1167                         fd_nonblock(socket_fd, false);
1168
1169                 err = setup_input(context, socket_fd, apply_tty_stdin);
1170                 if (err < 0) {
1171                         r = EXIT_STDIN;
1172                         goto fail_child;
1173                 }
1174
1175                 err = setup_output(context, STDOUT_FILENO, socket_fd, path_get_file_name(command->path), unit_id, apply_tty_stdin);
1176                 if (err < 0) {
1177                         r = EXIT_STDOUT;
1178                         goto fail_child;
1179                 }
1180
1181                 err = setup_output(context, STDERR_FILENO, socket_fd, path_get_file_name(command->path), unit_id, apply_tty_stdin);
1182                 if (err < 0) {
1183                         r = EXIT_STDERR;
1184                         goto fail_child;
1185                 }
1186
1187                 if (cgroup_bondings) {
1188                         err = cgroup_bonding_install_list(cgroup_bondings, 0, cgroup_suffix);
1189                         if (err < 0) {
1190                                 r = EXIT_CGROUP;
1191                                 goto fail_child;
1192                         }
1193                 }
1194
1195                 if (context->oom_score_adjust_set) {
1196                         char t[16];
1197
1198                         snprintf(t, sizeof(t), "%i", context->oom_score_adjust);
1199                         char_array_0(t);
1200
1201                         if (write_string_file("/proc/self/oom_score_adj", t) < 0) {
1202                                 err = -errno;
1203                                 r = EXIT_OOM_ADJUST;
1204                                 goto fail_child;
1205                         }
1206                 }
1207
1208                 if (context->nice_set)
1209                         if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
1210                                 err = -errno;
1211                                 r = EXIT_NICE;
1212                                 goto fail_child;
1213                         }
1214
1215                 if (context->cpu_sched_set) {
1216                         struct sched_param param = {
1217                                 .sched_priority = context->cpu_sched_priority,
1218                         };
1219
1220                         r = sched_setscheduler(0,
1221                                                context->cpu_sched_policy |
1222                                                (context->cpu_sched_reset_on_fork ?
1223                                                 SCHED_RESET_ON_FORK : 0),
1224                                                &param);
1225                         if (r < 0) {
1226                                 err = -errno;
1227                                 r = EXIT_SETSCHEDULER;
1228                                 goto fail_child;
1229                         }
1230                 }
1231
1232                 if (context->cpuset)
1233                         if (sched_setaffinity(0, CPU_ALLOC_SIZE(context->cpuset_ncpus), context->cpuset) < 0) {
1234                                 err = -errno;
1235                                 r = EXIT_CPUAFFINITY;
1236                                 goto fail_child;
1237                         }
1238
1239                 if (context->ioprio_set)
1240                         if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {
1241                                 err = -errno;
1242                                 r = EXIT_IOPRIO;
1243                                 goto fail_child;
1244                         }
1245
1246                 if (context->timer_slack_nsec != (nsec_t) -1)
1247                         if (prctl(PR_SET_TIMERSLACK, context->timer_slack_nsec) < 0) {
1248                                 err = -errno;
1249                                 r = EXIT_TIMERSLACK;
1250                                 goto fail_child;
1251                         }
1252
1253                 if (context->utmp_id)
1254                         utmp_put_init_process(context->utmp_id, getpid(), getsid(0), context->tty_path);
1255
1256                 if (context->user) {
1257                         username = context->user;
1258                         err = get_user_creds(&username, &uid, &gid, &home, NULL);
1259                         if (err < 0) {
1260                                 r = EXIT_USER;
1261                                 goto fail_child;
1262                         }
1263
1264                         if (is_terminal_input(context->std_input)) {
1265                                 err = chown_terminal(STDIN_FILENO, uid);
1266                                 if (err < 0) {
1267                                         r = EXIT_STDIN;
1268                                         goto fail_child;
1269                                 }
1270                         }
1271
1272                         if (cgroup_bondings && context->control_group_modify) {
1273                                 err = cgroup_bonding_set_group_access_list(cgroup_bondings, 0755, uid, gid);
1274                                 if (err >= 0)
1275                                         err = cgroup_bonding_set_task_access_list(
1276                                                         cgroup_bondings,
1277                                                         0644,
1278                                                         uid,
1279                                                         gid,
1280                                                         context->control_group_persistent);
1281                                 if (err < 0) {
1282                                         r = EXIT_CGROUP;
1283                                         goto fail_child;
1284                                 }
1285
1286                                 set_access = true;
1287                         }
1288                 }
1289
1290                 if (cgroup_bondings && !set_access && context->control_group_persistent >= 0)  {
1291                         err = cgroup_bonding_set_task_access_list(
1292                                         cgroup_bondings,
1293                                         (mode_t) -1,
1294                                         (uid_t) -1,
1295                                         (uid_t) -1,
1296                                         context->control_group_persistent);
1297                         if (err < 0) {
1298                                 r = EXIT_CGROUP;
1299                                 goto fail_child;
1300                         }
1301                 }
1302
1303                 if (apply_permissions) {
1304                         err = enforce_groups(context, username, gid);
1305                         if (err < 0) {
1306                                 r = EXIT_GROUP;
1307                                 goto fail_child;
1308                         }
1309                 }
1310
1311                 umask(context->umask);
1312
1313 #ifdef HAVE_PAM
1314                 if (apply_permissions && context->pam_name && username) {
1315                         err = setup_pam(context->pam_name, username, uid, context->tty_path, &pam_env, fds, n_fds);
1316                         if (err < 0) {
1317                                 r = EXIT_PAM;
1318                                 goto fail_child;
1319                         }
1320                 }
1321 #endif
1322                 if (context->private_network) {
1323                         if (unshare(CLONE_NEWNET) < 0) {
1324                                 err = -errno;
1325                                 r = EXIT_NETWORK;
1326                                 goto fail_child;
1327                         }
1328
1329                         loopback_setup();
1330                 }
1331
1332                 if (strv_length(context->read_write_dirs) > 0 ||
1333                     strv_length(context->read_only_dirs) > 0 ||
1334                     strv_length(context->inaccessible_dirs) > 0 ||
1335                     context->mount_flags != 0 ||
1336                     context->private_tmp) {
1337                         err = setup_namespace(context->read_write_dirs,
1338                                               context->read_only_dirs,
1339                                               context->inaccessible_dirs,
1340                                               context->tmp_dir,
1341                                               context->var_tmp_dir,
1342                                               context->private_tmp,
1343                                               context->mount_flags);
1344                         if (err < 0) {
1345                                 r = EXIT_NAMESPACE;
1346                                 goto fail_child;
1347                         }
1348                 }
1349
1350                 if (apply_chroot) {
1351                         if (context->root_directory)
1352                                 if (chroot(context->root_directory) < 0) {
1353                                         err = -errno;
1354                                         r = EXIT_CHROOT;
1355                                         goto fail_child;
1356                                 }
1357
1358                         if (chdir(context->working_directory ? context->working_directory : "/") < 0) {
1359                                 err = -errno;
1360                                 r = EXIT_CHDIR;
1361                                 goto fail_child;
1362                         }
1363                 } else {
1364                         char _cleanup_free_ *d = NULL;
1365
1366                         if (asprintf(&d, "%s/%s",
1367                                      context->root_directory ? context->root_directory : "",
1368                                      context->working_directory ? context->working_directory : "") < 0) {
1369                                 err = -ENOMEM;
1370                                 r = EXIT_MEMORY;
1371                                 goto fail_child;
1372                         }
1373
1374                         if (chdir(d) < 0) {
1375                                 err = -errno;
1376                                 r = EXIT_CHDIR;
1377                                 goto fail_child;
1378                         }
1379                 }
1380
1381                 /* We repeat the fd closing here, to make sure that
1382                  * nothing is leaked from the PAM modules */
1383                 err = close_all_fds(fds, n_fds);
1384                 if (err >= 0)
1385                         err = shift_fds(fds, n_fds);
1386                 if (err >= 0)
1387                         err = flags_fds(fds, n_fds, context->non_blocking);
1388                 if (err < 0) {
1389                         r = EXIT_FDS;
1390                         goto fail_child;
1391                 }
1392
1393                 if (apply_permissions) {
1394
1395                         for (i = 0; i < RLIMIT_NLIMITS; i++) {
1396                                 if (!context->rlimit[i])
1397                                         continue;
1398
1399                                 if (setrlimit_closest(i, context->rlimit[i]) < 0) {
1400                                         err = -errno;
1401                                         r = EXIT_LIMITS;
1402                                         goto fail_child;
1403                                 }
1404                         }
1405
1406                         if (context->capability_bounding_set_drop) {
1407                                 err = capability_bounding_set_drop(context->capability_bounding_set_drop, false);
1408                                 if (err < 0) {
1409                                         r = EXIT_CAPABILITIES;
1410                                         goto fail_child;
1411                                 }
1412                         }
1413
1414                         if (context->user) {
1415                                 err = enforce_user(context, uid);
1416                                 if (err < 0) {
1417                                         r = EXIT_USER;
1418                                         goto fail_child;
1419                                 }
1420                         }
1421
1422                         /* PR_GET_SECUREBITS is not privileged, while
1423                          * PR_SET_SECUREBITS is. So to suppress
1424                          * potential EPERMs we'll try not to call
1425                          * PR_SET_SECUREBITS unless necessary. */
1426                         if (prctl(PR_GET_SECUREBITS) != context->secure_bits)
1427                                 if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) {
1428                                         err = -errno;
1429                                         r = EXIT_SECUREBITS;
1430                                         goto fail_child;
1431                                 }
1432
1433                         if (context->capabilities)
1434                                 if (cap_set_proc(context->capabilities) < 0) {
1435                                         err = -errno;
1436                                         r = EXIT_CAPABILITIES;
1437                                         goto fail_child;
1438                                 }
1439
1440                         if (context->no_new_privileges)
1441                                 if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
1442                                         err = -errno;
1443                                         r = EXIT_NO_NEW_PRIVILEGES;
1444                                         goto fail_child;
1445                                 }
1446
1447                         if (context->syscall_filter) {
1448                                 err = apply_seccomp(context->syscall_filter);
1449                                 if (err < 0) {
1450                                         r = EXIT_SECCOMP;
1451                                         goto fail_child;
1452                                 }
1453                         }
1454                 }
1455
1456                 our_env = new0(char*, 7);
1457                 if (!our_env) {
1458                         err = -ENOMEM;
1459                         r = EXIT_MEMORY;
1460                         goto fail_child;
1461                 }
1462
1463                 if (n_fds > 0)
1464                         if (asprintf(our_env + n_env++, "LISTEN_PID=%lu", (unsigned long) getpid()) < 0 ||
1465                             asprintf(our_env + n_env++, "LISTEN_FDS=%u", n_fds) < 0) {
1466                                 err = -ENOMEM;
1467                                 r = EXIT_MEMORY;
1468                                 goto fail_child;
1469                         }
1470
1471                 if (home)
1472                         if (asprintf(our_env + n_env++, "HOME=%s", home) < 0) {
1473                                 err = -ENOMEM;
1474                                 r = EXIT_MEMORY;
1475                                 goto fail_child;
1476                         }
1477
1478                 if (username)
1479                         if (asprintf(our_env + n_env++, "LOGNAME=%s", username) < 0 ||
1480                             asprintf(our_env + n_env++, "USER=%s", username) < 0) {
1481                                 err = -ENOMEM;
1482                                 r = EXIT_MEMORY;
1483                                 goto fail_child;
1484                         }
1485
1486                 if (is_terminal_input(context->std_input) ||
1487                     context->std_output == EXEC_OUTPUT_TTY ||
1488                     context->std_error == EXEC_OUTPUT_TTY)
1489                         if (!(our_env[n_env++] = strdup(default_term_for_tty(tty_path(context))))) {
1490                                 err = -ENOMEM;
1491                                 r = EXIT_MEMORY;
1492                                 goto fail_child;
1493                         }
1494
1495                 assert(n_env <= 7);
1496
1497                 final_env = strv_env_merge(5,
1498                                            environment,
1499                                            our_env,
1500                                            context->environment,
1501                                            files_env,
1502                                            pam_env,
1503                                            NULL);
1504                 if (!final_env) {
1505                         err = -ENOMEM;
1506                         r = EXIT_MEMORY;
1507                         goto fail_child;
1508                 }
1509
1510                 final_argv = replace_env_argv(argv, final_env);
1511                 if (!final_argv) {
1512                         err = -ENOMEM;
1513                         r = EXIT_MEMORY;
1514                         goto fail_child;
1515                 }
1516
1517                 final_env = strv_env_clean(final_env);
1518
1519                 execve(command->path, final_argv, final_env);
1520                 err = -errno;
1521                 r = EXIT_EXEC;
1522
1523         fail_child:
1524                 if (r != 0) {
1525                         log_open();
1526                         log_struct(LOG_ERR, MESSAGE_ID(SD_MESSAGE_SPAWN_FAILED),
1527                                    "EXECUTABLE=%s", command->path,
1528                                    "MESSAGE=Failed at step %s spawning %s: %s",
1529                                           exit_status_to_string(r, EXIT_STATUS_SYSTEMD),
1530                                           command->path, strerror(-err),
1531                                    "ERRNO=%d", -err,
1532                                    NULL);
1533                         log_close();
1534                 }
1535
1536                 _exit(r);
1537         }
1538
1539         log_struct_unit(LOG_DEBUG,
1540                         unit_id,
1541                         "MESSAGE=Forked %s as %lu",
1542                         command->path, (unsigned long) pid,
1543                         NULL);
1544
1545         /* We add the new process to the cgroup both in the child (so
1546          * that we can be sure that no user code is ever executed
1547          * outside of the cgroup) and in the parent (so that we can be
1548          * sure that when we kill the cgroup the process will be
1549          * killed too). */
1550         cgroup_bonding_install_list(cgroup_bondings, pid, cgroup_suffix);
1551
1552         exec_status_start(&command->exec_status, pid);
1553
1554         *ret = pid;
1555         return 0;
1556 }
1557
1558 void exec_context_init(ExecContext *c) {
1559         assert(c);
1560
1561         c->umask = 0022;
1562         c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);
1563         c->cpu_sched_policy = SCHED_OTHER;
1564         c->syslog_priority = LOG_DAEMON|LOG_INFO;
1565         c->syslog_level_prefix = true;
1566         c->control_group_persistent = -1;
1567         c->ignore_sigpipe = true;
1568         c->timer_slack_nsec = (nsec_t) -1;
1569 }
1570
1571 void exec_context_tmp_dirs_done(ExecContext *c) {
1572         char* dirs[] = {c->tmp_dir ? c->tmp_dir : c->var_tmp_dir,
1573                         c->tmp_dir ? c->var_tmp_dir : NULL,
1574                         NULL};
1575         char **dirp;
1576
1577         for(dirp = dirs; *dirp; dirp++) {
1578                 char *dir;
1579                 int r;
1580
1581                 r = rm_rf_dangerous(*dirp, false, true, false);
1582                 dir = dirname(*dirp);
1583                 if (r < 0)
1584                         log_warning("Failed to remove content of temporary directory %s: %s",
1585                                     dir, strerror(-r));
1586                 else {
1587                         r = rmdir(dir);
1588                         if (r < 0)
1589                                 log_warning("Failed to remove  temporary directory %s: %s",
1590                                             dir, strerror(-r));
1591                 }
1592
1593                 free(*dirp);
1594         }
1595
1596         c->tmp_dir = c->var_tmp_dir = NULL;
1597 }
1598
1599 void exec_context_done(ExecContext *c, bool reloading_or_reexecuting) {
1600         unsigned l;
1601
1602         assert(c);
1603
1604         strv_free(c->environment);
1605         c->environment = NULL;
1606
1607         strv_free(c->environment_files);
1608         c->environment_files = NULL;
1609
1610         for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {
1611                 free(c->rlimit[l]);
1612                 c->rlimit[l] = NULL;
1613         }
1614
1615         free(c->working_directory);
1616         c->working_directory = NULL;
1617         free(c->root_directory);
1618         c->root_directory = NULL;
1619
1620         free(c->tty_path);
1621         c->tty_path = NULL;
1622
1623         free(c->tcpwrap_name);
1624         c->tcpwrap_name = NULL;
1625
1626         free(c->syslog_identifier);
1627         c->syslog_identifier = NULL;
1628
1629         free(c->user);
1630         c->user = NULL;
1631
1632         free(c->group);
1633         c->group = NULL;
1634
1635         strv_free(c->supplementary_groups);
1636         c->supplementary_groups = NULL;
1637
1638         free(c->pam_name);
1639         c->pam_name = NULL;
1640
1641         if (c->capabilities) {
1642                 cap_free(c->capabilities);
1643                 c->capabilities = NULL;
1644         }
1645
1646         strv_free(c->read_only_dirs);
1647         c->read_only_dirs = NULL;
1648
1649         strv_free(c->read_write_dirs);
1650         c->read_write_dirs = NULL;
1651
1652         strv_free(c->inaccessible_dirs);
1653         c->inaccessible_dirs = NULL;
1654
1655         if (c->cpuset)
1656                 CPU_FREE(c->cpuset);
1657
1658         free(c->utmp_id);
1659         c->utmp_id = NULL;
1660
1661         free(c->syscall_filter);
1662         c->syscall_filter = NULL;
1663
1664         if (!reloading_or_reexecuting)
1665                 exec_context_tmp_dirs_done(c);
1666 }
1667
1668 void exec_command_done(ExecCommand *c) {
1669         assert(c);
1670
1671         free(c->path);
1672         c->path = NULL;
1673
1674         strv_free(c->argv);
1675         c->argv = NULL;
1676 }
1677
1678 void exec_command_done_array(ExecCommand *c, unsigned n) {
1679         unsigned i;
1680
1681         for (i = 0; i < n; i++)
1682                 exec_command_done(c+i);
1683 }
1684
1685 void exec_command_free_list(ExecCommand *c) {
1686         ExecCommand *i;
1687
1688         while ((i = c)) {
1689                 LIST_REMOVE(ExecCommand, command, c, i);
1690                 exec_command_done(i);
1691                 free(i);
1692         }
1693 }
1694
1695 void exec_command_free_array(ExecCommand **c, unsigned n) {
1696         unsigned i;
1697
1698         for (i = 0; i < n; i++) {
1699                 exec_command_free_list(c[i]);
1700                 c[i] = NULL;
1701         }
1702 }
1703
1704 int exec_context_load_environment(const ExecContext *c, char ***l) {
1705         char **i, **r = NULL;
1706
1707         assert(c);
1708         assert(l);
1709
1710         STRV_FOREACH(i, c->environment_files) {
1711                 char *fn;
1712                 int k;
1713                 bool ignore = false;
1714                 char **p;
1715                 glob_t _cleanup_globfree_ pglob = {};
1716                 int count, n;
1717
1718                 fn = *i;
1719
1720                 if (fn[0] == '-') {
1721                         ignore = true;
1722                         fn ++;
1723                 }
1724
1725                 if (!path_is_absolute(fn)) {
1726                         if (ignore)
1727                                 continue;
1728
1729                         strv_free(r);
1730                         return -EINVAL;
1731                 }
1732
1733                 /* Filename supports globbing, take all matching files */
1734                 errno = 0;
1735                 if (glob(fn, 0, NULL, &pglob) != 0) {
1736                         if (ignore)
1737                                 continue;
1738
1739                         strv_free(r);
1740                         return errno ? -errno : -EINVAL;
1741                 }
1742                 count = pglob.gl_pathc;
1743                 if (count == 0) {
1744                         if (ignore)
1745                                 continue;
1746
1747                         strv_free(r);
1748                         return -EINVAL;
1749                 }
1750                 for (n = 0; n < count; n++) {
1751                         k = load_env_file(pglob.gl_pathv[n], NULL, &p);
1752                         if (k < 0) {
1753                                 if (ignore)
1754                                         continue;
1755
1756                                 strv_free(r);
1757                                 return k;
1758                          }
1759
1760                         if (r == NULL)
1761                                 r = p;
1762                         else {
1763                                 char **m;
1764
1765                                 m = strv_env_merge(2, r, p);
1766                                 strv_free(r);
1767                                 strv_free(p);
1768                                 if (!m)
1769                                         return -ENOMEM;
1770
1771                                 r = m;
1772                         }
1773                 }
1774         }
1775
1776         *l = r;
1777
1778         return 0;
1779 }
1780
1781 static bool tty_may_match_dev_console(const char *tty) {
1782         char *active = NULL, *console;
1783         bool b;
1784
1785         if (startswith(tty, "/dev/"))
1786                 tty += 5;
1787
1788         /* trivial identity? */
1789         if (streq(tty, "console"))
1790                 return true;
1791
1792         console = resolve_dev_console(&active);
1793         /* if we could not resolve, assume it may */
1794         if (!console)
1795                 return true;
1796
1797         /* "tty0" means the active VC, so it may be the same sometimes */
1798         b = streq(console, tty) || (streq(console, "tty0") && tty_is_vc(tty));
1799         free(active);
1800
1801         return b;
1802 }
1803
1804 bool exec_context_may_touch_console(ExecContext *ec) {
1805         return (ec->tty_reset || ec->tty_vhangup || ec->tty_vt_disallocate ||
1806                 is_terminal_input(ec->std_input) ||
1807                 is_terminal_output(ec->std_output) ||
1808                 is_terminal_output(ec->std_error)) &&
1809                tty_may_match_dev_console(tty_path(ec));
1810 }
1811
1812 static void strv_fprintf(FILE *f, char **l) {
1813         char **g;
1814
1815         assert(f);
1816
1817         STRV_FOREACH(g, l)
1818                 fprintf(f, " %s", *g);
1819 }
1820
1821 void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
1822         char ** e;
1823         unsigned i;
1824
1825         assert(c);
1826         assert(f);
1827
1828         if (!prefix)
1829                 prefix = "";
1830
1831         fprintf(f,
1832                 "%sUMask: %04o\n"
1833                 "%sWorkingDirectory: %s\n"
1834                 "%sRootDirectory: %s\n"
1835                 "%sNonBlocking: %s\n"
1836                 "%sPrivateTmp: %s\n"
1837                 "%sControlGroupModify: %s\n"
1838                 "%sControlGroupPersistent: %s\n"
1839                 "%sPrivateNetwork: %s\n"
1840                 "%sIgnoreSIGPIPE: %s\n",
1841                 prefix, c->umask,
1842                 prefix, c->working_directory ? c->working_directory : "/",
1843                 prefix, c->root_directory ? c->root_directory : "/",
1844                 prefix, yes_no(c->non_blocking),
1845                 prefix, yes_no(c->private_tmp),
1846                 prefix, yes_no(c->control_group_modify),
1847                 prefix, yes_no(c->control_group_persistent),
1848                 prefix, yes_no(c->private_network),
1849                 prefix, yes_no(c->ignore_sigpipe));
1850
1851         STRV_FOREACH(e, c->environment)
1852                 fprintf(f, "%sEnvironment: %s\n", prefix, *e);
1853
1854         STRV_FOREACH(e, c->environment_files)
1855                 fprintf(f, "%sEnvironmentFile: %s\n", prefix, *e);
1856
1857         if (c->tcpwrap_name)
1858                 fprintf(f,
1859                         "%sTCPWrapName: %s\n",
1860                         prefix, c->tcpwrap_name);
1861
1862         if (c->nice_set)
1863                 fprintf(f,
1864                         "%sNice: %i\n",
1865                         prefix, c->nice);
1866
1867         if (c->oom_score_adjust_set)
1868                 fprintf(f,
1869                         "%sOOMScoreAdjust: %i\n",
1870                         prefix, c->oom_score_adjust);
1871
1872         for (i = 0; i < RLIM_NLIMITS; i++)
1873                 if (c->rlimit[i])
1874                         fprintf(f, "%s%s: %llu\n", prefix, rlimit_to_string(i), (unsigned long long) c->rlimit[i]->rlim_max);
1875
1876         if (c->ioprio_set) {
1877                 char *class_str;
1878                 int r;
1879
1880                 r = ioprio_class_to_string_alloc(IOPRIO_PRIO_CLASS(c->ioprio), &class_str);
1881                 if (r < 0)
1882                         class_str = NULL;
1883                 fprintf(f,
1884                         "%sIOSchedulingClass: %s\n"
1885                         "%sIOPriority: %i\n",
1886                         prefix, strna(class_str),
1887                         prefix, (int) IOPRIO_PRIO_DATA(c->ioprio));
1888                 free(class_str);
1889         }
1890
1891         if (c->cpu_sched_set) {
1892                 char *policy_str;
1893                 int r;
1894
1895                 r = sched_policy_to_string_alloc(c->cpu_sched_policy, &policy_str);
1896                 if (r < 0)
1897                         policy_str = NULL;
1898                 fprintf(f,
1899                         "%sCPUSchedulingPolicy: %s\n"
1900                         "%sCPUSchedulingPriority: %i\n"
1901                         "%sCPUSchedulingResetOnFork: %s\n",
1902                         prefix, strna(policy_str),
1903                         prefix, c->cpu_sched_priority,
1904                         prefix, yes_no(c->cpu_sched_reset_on_fork));
1905                 free(policy_str);
1906         }
1907
1908         if (c->cpuset) {
1909                 fprintf(f, "%sCPUAffinity:", prefix);
1910                 for (i = 0; i < c->cpuset_ncpus; i++)
1911                         if (CPU_ISSET_S(i, CPU_ALLOC_SIZE(c->cpuset_ncpus), c->cpuset))
1912                                 fprintf(f, " %i", i);
1913                 fputs("\n", f);
1914         }
1915
1916         if (c->timer_slack_nsec != (nsec_t) -1)
1917                 fprintf(f, "%sTimerSlackNSec: %lu\n", prefix, (unsigned long)c->timer_slack_nsec);
1918
1919         fprintf(f,
1920                 "%sStandardInput: %s\n"
1921                 "%sStandardOutput: %s\n"
1922                 "%sStandardError: %s\n",
1923                 prefix, exec_input_to_string(c->std_input),
1924                 prefix, exec_output_to_string(c->std_output),
1925                 prefix, exec_output_to_string(c->std_error));
1926
1927         if (c->tty_path)
1928                 fprintf(f,
1929                         "%sTTYPath: %s\n"
1930                         "%sTTYReset: %s\n"
1931                         "%sTTYVHangup: %s\n"
1932                         "%sTTYVTDisallocate: %s\n",
1933                         prefix, c->tty_path,
1934                         prefix, yes_no(c->tty_reset),
1935                         prefix, yes_no(c->tty_vhangup),
1936                         prefix, yes_no(c->tty_vt_disallocate));
1937
1938         if (c->std_output == EXEC_OUTPUT_SYSLOG || c->std_output == EXEC_OUTPUT_KMSG || c->std_output == EXEC_OUTPUT_JOURNAL ||
1939             c->std_output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE || c->std_output == EXEC_OUTPUT_KMSG_AND_CONSOLE || c->std_output == EXEC_OUTPUT_JOURNAL_AND_CONSOLE ||
1940             c->std_error == EXEC_OUTPUT_SYSLOG || c->std_error == EXEC_OUTPUT_KMSG || c->std_error == EXEC_OUTPUT_JOURNAL ||
1941             c->std_error == EXEC_OUTPUT_SYSLOG_AND_CONSOLE || c->std_error == EXEC_OUTPUT_KMSG_AND_CONSOLE || c->std_error == EXEC_OUTPUT_JOURNAL_AND_CONSOLE) {
1942                 char *fac_str, *lvl_str;
1943                 int r;
1944
1945                 r = log_facility_unshifted_to_string_alloc(c->syslog_priority >> 3, &fac_str);
1946                 if (r < 0)
1947                         fac_str = NULL;
1948
1949                 r = log_level_to_string_alloc(LOG_PRI(c->syslog_priority), &lvl_str);
1950                 if (r < 0)
1951                         lvl_str = NULL;
1952
1953                 fprintf(f,
1954                         "%sSyslogFacility: %s\n"
1955                         "%sSyslogLevel: %s\n",
1956                         prefix, strna(fac_str),
1957                         prefix, strna(lvl_str));
1958                 free(lvl_str);
1959                 free(fac_str);
1960         }
1961
1962         if (c->capabilities) {
1963                 char *t;
1964                 if ((t = cap_to_text(c->capabilities, NULL))) {
1965                         fprintf(f, "%sCapabilities: %s\n",
1966                                 prefix, t);
1967                         cap_free(t);
1968                 }
1969         }
1970
1971         if (c->secure_bits)
1972                 fprintf(f, "%sSecure Bits:%s%s%s%s%s%s\n",
1973                         prefix,
1974                         (c->secure_bits & 1<<SECURE_KEEP_CAPS) ? " keep-caps" : "",
1975                         (c->secure_bits & 1<<SECURE_KEEP_CAPS_LOCKED) ? " keep-caps-locked" : "",
1976                         (c->secure_bits & 1<<SECURE_NO_SETUID_FIXUP) ? " no-setuid-fixup" : "",
1977                         (c->secure_bits & 1<<SECURE_NO_SETUID_FIXUP_LOCKED) ? " no-setuid-fixup-locked" : "",
1978                         (c->secure_bits & 1<<SECURE_NOROOT) ? " noroot" : "",
1979                         (c->secure_bits & 1<<SECURE_NOROOT_LOCKED) ? "noroot-locked" : "");
1980
1981         if (c->capability_bounding_set_drop) {
1982                 unsigned long l;
1983                 fprintf(f, "%sCapabilityBoundingSet:", prefix);
1984
1985                 for (l = 0; l <= cap_last_cap(); l++)
1986                         if (!(c->capability_bounding_set_drop & ((uint64_t) 1ULL << (uint64_t) l))) {
1987                                 char *t;
1988
1989                                 if ((t = cap_to_name(l))) {
1990                                         fprintf(f, " %s", t);
1991                                         cap_free(t);
1992                                 }
1993                         }
1994
1995                 fputs("\n", f);
1996         }
1997
1998         if (c->user)
1999                 fprintf(f, "%sUser: %s\n", prefix, c->user);
2000         if (c->group)
2001                 fprintf(f, "%sGroup: %s\n", prefix, c->group);
2002
2003         if (strv_length(c->supplementary_groups) > 0) {
2004                 fprintf(f, "%sSupplementaryGroups:", prefix);
2005                 strv_fprintf(f, c->supplementary_groups);
2006                 fputs("\n", f);
2007         }
2008
2009         if (c->pam_name)
2010                 fprintf(f, "%sPAMName: %s\n", prefix, c->pam_name);
2011
2012         if (strv_length(c->read_write_dirs) > 0) {
2013                 fprintf(f, "%sReadWriteDirs:", prefix);
2014                 strv_fprintf(f, c->read_write_dirs);
2015                 fputs("\n", f);
2016         }
2017
2018         if (strv_length(c->read_only_dirs) > 0) {
2019                 fprintf(f, "%sReadOnlyDirs:", prefix);
2020                 strv_fprintf(f, c->read_only_dirs);
2021                 fputs("\n", f);
2022         }
2023
2024         if (strv_length(c->inaccessible_dirs) > 0) {
2025                 fprintf(f, "%sInaccessibleDirs:", prefix);
2026                 strv_fprintf(f, c->inaccessible_dirs);
2027                 fputs("\n", f);
2028         }
2029
2030         if (c->utmp_id)
2031                 fprintf(f,
2032                         "%sUtmpIdentifier: %s\n",
2033                         prefix, c->utmp_id);
2034 }
2035
2036 void exec_status_start(ExecStatus *s, pid_t pid) {
2037         assert(s);
2038
2039         zero(*s);
2040         s->pid = pid;
2041         dual_timestamp_get(&s->start_timestamp);
2042 }
2043
2044 void exec_status_exit(ExecStatus *s, ExecContext *context, pid_t pid, int code, int status) {
2045         assert(s);
2046
2047         if (s->pid && s->pid != pid)
2048                 zero(*s);
2049
2050         s->pid = pid;
2051         dual_timestamp_get(&s->exit_timestamp);
2052
2053         s->code = code;
2054         s->status = status;
2055
2056         if (context) {
2057                 if (context->utmp_id)
2058                         utmp_put_dead_process(context->utmp_id, pid, code, status);
2059
2060                 exec_context_tty_reset(context);
2061         }
2062 }
2063
2064 void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix) {
2065         char buf[FORMAT_TIMESTAMP_MAX];
2066
2067         assert(s);
2068         assert(f);
2069
2070         if (!prefix)
2071                 prefix = "";
2072
2073         if (s->pid <= 0)
2074                 return;
2075
2076         fprintf(f,
2077                 "%sPID: %lu\n",
2078                 prefix, (unsigned long) s->pid);
2079
2080         if (s->start_timestamp.realtime > 0)
2081                 fprintf(f,
2082                         "%sStart Timestamp: %s\n",
2083                         prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp.realtime));
2084
2085         if (s->exit_timestamp.realtime > 0)
2086                 fprintf(f,
2087                         "%sExit Timestamp: %s\n"
2088                         "%sExit Code: %s\n"
2089                         "%sExit Status: %i\n",
2090                         prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp.realtime),
2091                         prefix, sigchld_code_to_string(s->code),
2092                         prefix, s->status);
2093 }
2094
2095 char *exec_command_line(char **argv) {
2096         size_t k;
2097         char *n, *p, **a;
2098         bool first = true;
2099
2100         assert(argv);
2101
2102         k = 1;
2103         STRV_FOREACH(a, argv)
2104                 k += strlen(*a)+3;
2105
2106         if (!(n = new(char, k)))
2107                 return NULL;
2108
2109         p = n;
2110         STRV_FOREACH(a, argv) {
2111
2112                 if (!first)
2113                         *(p++) = ' ';
2114                 else
2115                         first = false;
2116
2117                 if (strpbrk(*a, WHITESPACE)) {
2118                         *(p++) = '\'';
2119                         p = stpcpy(p, *a);
2120                         *(p++) = '\'';
2121                 } else
2122                         p = stpcpy(p, *a);
2123
2124         }
2125
2126         *p = 0;
2127
2128         /* FIXME: this doesn't really handle arguments that have
2129          * spaces and ticks in them */
2130
2131         return n;
2132 }
2133
2134 void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
2135         char *p2;
2136         const char *prefix2;
2137
2138         char *cmd;
2139
2140         assert(c);
2141         assert(f);
2142
2143         if (!prefix)
2144                 prefix = "";
2145         p2 = strappend(prefix, "\t");
2146         prefix2 = p2 ? p2 : prefix;
2147
2148         cmd = exec_command_line(c->argv);
2149
2150         fprintf(f,
2151                 "%sCommand Line: %s\n",
2152                 prefix, cmd ? cmd : strerror(ENOMEM));
2153
2154         free(cmd);
2155
2156         exec_status_dump(&c->exec_status, f, prefix2);
2157
2158         free(p2);
2159 }
2160
2161 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
2162         assert(f);
2163
2164         if (!prefix)
2165                 prefix = "";
2166
2167         LIST_FOREACH(command, c, c)
2168                 exec_command_dump(c, f, prefix);
2169 }
2170
2171 void exec_command_append_list(ExecCommand **l, ExecCommand *e) {
2172         ExecCommand *end;
2173
2174         assert(l);
2175         assert(e);
2176
2177         if (*l) {
2178                 /* It's kind of important, that we keep the order here */
2179                 LIST_FIND_TAIL(ExecCommand, command, *l, end);
2180                 LIST_INSERT_AFTER(ExecCommand, command, *l, end, e);
2181         } else
2182               *l = e;
2183 }
2184
2185 int exec_command_set(ExecCommand *c, const char *path, ...) {
2186         va_list ap;
2187         char **l, *p;
2188
2189         assert(c);
2190         assert(path);
2191
2192         va_start(ap, path);
2193         l = strv_new_ap(path, ap);
2194         va_end(ap);
2195
2196         if (!l)
2197                 return -ENOMEM;
2198
2199         if (!(p = strdup(path))) {
2200                 strv_free(l);
2201                 return -ENOMEM;
2202         }
2203
2204         free(c->path);
2205         c->path = p;
2206
2207         strv_free(c->argv);
2208         c->argv = l;
2209
2210         return 0;
2211 }
2212
2213 static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
2214         [EXEC_INPUT_NULL] = "null",
2215         [EXEC_INPUT_TTY] = "tty",
2216         [EXEC_INPUT_TTY_FORCE] = "tty-force",
2217         [EXEC_INPUT_TTY_FAIL] = "tty-fail",
2218         [EXEC_INPUT_SOCKET] = "socket"
2219 };
2220
2221 DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);
2222
2223 static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
2224         [EXEC_OUTPUT_INHERIT] = "inherit",
2225         [EXEC_OUTPUT_NULL] = "null",
2226         [EXEC_OUTPUT_TTY] = "tty",
2227         [EXEC_OUTPUT_SYSLOG] = "syslog",
2228         [EXEC_OUTPUT_SYSLOG_AND_CONSOLE] = "syslog+console",
2229         [EXEC_OUTPUT_KMSG] = "kmsg",
2230         [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
2231         [EXEC_OUTPUT_JOURNAL] = "journal",
2232         [EXEC_OUTPUT_JOURNAL_AND_CONSOLE] = "journal+console",
2233         [EXEC_OUTPUT_SOCKET] = "socket"
2234 };
2235
2236 DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);