src/core/execute.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <glob.h>
   6 #include <grp.h>
   7 #include <poll.h>
   8 #include <signal.h>
   9 #include <string.h>
  10 #include <sys/capability.h>
  11 #include <sys/eventfd.h>
  12 #include <sys/mman.h>
  13 #include <sys/personality.h>
  14 #include <sys/prctl.h>
  15 #include <sys/shm.h>
  16 #include <sys/socket.h>
  17 #include <sys/stat.h>
  18 #include <sys/types.h>
  19 #include <sys/un.h>
  20 #include <unistd.h>
  21 #include <utmpx.h>
  22
  23 #if HAVE_PAM
  24 #include <security/pam_appl.h>
  25 #endif
  26
  27 #if HAVE_SELINUX
  28 #include <selinux/selinux.h>
  29 #endif
  30
  31 #if HAVE_SECCOMP
  32 #include <seccomp.h>
  33 #endif
  34
  35 #if HAVE_APPARMOR
  36 #include <sys/apparmor.h>
  37 #endif
  38
  39 #include "sd-messages.h"
  40
  41 #include "af-list.h"
  42 #include "alloc-util.h"
  43 #if HAVE_APPARMOR
  44 #include "apparmor-util.h"
  45 #endif
  46 #include "async.h"
  47 #include "barrier.h"
  48 #include "cap-list.h"
  49 #include "capability-util.h"
  50 #include "chown-recursive.h"
  51 #include "cpu-set-util.h"
  52 #include "def.h"
  53 #include "env-file.h"
  54 #include "env-util.h"
  55 #include "errno-list.h"
  56 #include "execute.h"
  57 #include "exit-status.h"
  58 #include "fd-util.h"
  59 #include "format-util.h"
  60 #include "fs-util.h"
  61 #include "glob-util.h"
  62 #include "io-util.h"
  63 #include "ioprio.h"
  64 #include "label.h"
  65 #include "log.h"
  66 #include "macro.h"
  67 #include "manager.h"
  68 #include "missing.h"
  69 #include "mkdir.h"
  70 #include "namespace.h"
  71 #include "parse-util.h"
  72 #include "path-util.h"
  73 #include "process-util.h"
  74 #include "rlimit-util.h"
  75 #include "rm-rf.h"
  76 #if HAVE_SECCOMP
  77 #include "seccomp-util.h"
  78 #endif
  79 #include "securebits-util.h"
  80 #include "selinux-util.h"
  81 #include "signal-util.h"
  82 #include "smack-util.h"
  83 #include "socket-util.h"
  84 #include "special.h"
  85 #include "stat-util.h"
  86 #include "string-table.h"
  87 #include "string-util.h"
  88 #include "strv.h"
  89 #include "syslog-util.h"
  90 #include "terminal-util.h"
  91 #include "umask-util.h"
  92 #include "unit.h"
  93 #include "user-util.h"
  94 #include "util.h"
  95 #include "utmp-wtmp.h"
  96
  97 #define IDLE_TIMEOUT_USEC (5*USEC_PER_SEC)
  98 #define IDLE_TIMEOUT2_USEC (1*USEC_PER_SEC)
  99
 100 /* This assumes there is a 'tty' group */
 101 #define TTY_MODE 0620
 102
 103 #define SNDBUF_SIZE (8*1024*1024)
 104
 105 static int shift_fds(int fds[], size_t n_fds) {
 106         int start, restart_from;
 107
 108         if (n_fds <= 0)
 109                 return 0;
 110
 111         /* Modifies the fds array! (sorts it) */
 112
 113         assert(fds);
 114
 115         start = 0;
 116         for (;;) {
 117                 int i;
 118
 119                 restart_from = -1;
 120
 121                 for (i = start; i < (int) n_fds; i++) {
 122                         int nfd;
 123
 124                         /* Already at right index? */
 125                         if (fds[i] == i+3)
 126                                 continue;
 127
 128                         nfd = fcntl(fds[i], F_DUPFD, i + 3);
 129                         if (nfd < 0)
 130                                 return -errno;
 131
 132                         safe_close(fds[i]);
 133                         fds[i] = nfd;
 134
 135                         /* Hmm, the fd we wanted isn't free? Then
 136                          * let's remember that and try again from here */
 137                         if (nfd != i+3 && restart_from < 0)
 138                                 restart_from = i;
 139                 }
 140
 141                 if (restart_from < 0)
 142                         break;
 143
 144                 start = restart_from;
 145         }
 146
 147         return 0;
 148 }
 149
 150 static int flags_fds(const int fds[], size_t n_socket_fds, size_t n_storage_fds, bool nonblock) {
 151         size_t i, n_fds;
 152         int r;
 153
 154         n_fds = n_socket_fds + n_storage_fds;
 155         if (n_fds <= 0)
 156                 return 0;
 157
 158         assert(fds);
 159
 160         /* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags.
 161          * O_NONBLOCK only applies to socket activation though. */
 162
 163         for (i = 0; i < n_fds; i++) {
 164
 165                 if (i < n_socket_fds) {
 166                         r = fd_nonblock(fds[i], nonblock);
 167                         if (r < 0)
 168                                 return r;
 169                 }
 170
 171                 /* We unconditionally drop FD_CLOEXEC from the fds,
 172                  * since after all we want to pass these fds to our
 173                  * children */
 174
 175                 r = fd_cloexec(fds[i], false);
 176                 if (r < 0)
 177                         return r;
 178         }
 179
 180         return 0;
 181 }
 182
 183 static const char *exec_context_tty_path(const ExecContext *context) {
 184         assert(context);
 185
 186         if (context->stdio_as_fds)
 187                 return NULL;
 188
 189         if (context->tty_path)
 190                 return context->tty_path;
 191
 192         return "/dev/console";
 193 }
 194
 195 static void exec_context_tty_reset(const ExecContext *context, const ExecParameters *p) {
 196         const char *path;
 197
 198         assert(context);
 199
 200         path = exec_context_tty_path(context);
 201
 202         if (context->tty_vhangup) {
 203                 if (p && p->stdin_fd >= 0)
 204                         (void) terminal_vhangup_fd(p->stdin_fd);
 205                 else if (path)
 206                         (void) terminal_vhangup(path);
 207         }
 208
 209         if (context->tty_reset) {
 210                 if (p && p->stdin_fd >= 0)
 211                         (void) reset_terminal_fd(p->stdin_fd, true);
 212                 else if (path)
 213                         (void) reset_terminal(path);
 214         }
 215
 216         if (context->tty_vt_disallocate && path)
 217                 (void) vt_disallocate(path);
 218 }
 219
 220 static bool is_terminal_input(ExecInput i) {
 221         return IN_SET(i,
 222                       EXEC_INPUT_TTY,
 223                       EXEC_INPUT_TTY_FORCE,
 224                       EXEC_INPUT_TTY_FAIL);
 225 }
 226
 227 static bool is_terminal_output(ExecOutput o) {
 228         return IN_SET(o,
 229                       EXEC_OUTPUT_TTY,
 230                       EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
 231                       EXEC_OUTPUT_KMSG_AND_CONSOLE,
 232                       EXEC_OUTPUT_JOURNAL_AND_CONSOLE);
 233 }
 234
 235 static bool is_syslog_output(ExecOutput o) {
 236         return IN_SET(o,
 237                       EXEC_OUTPUT_SYSLOG,
 238                       EXEC_OUTPUT_SYSLOG_AND_CONSOLE);
 239 }
 240
 241 static bool is_kmsg_output(ExecOutput o) {
 242         return IN_SET(o,
 243                       EXEC_OUTPUT_KMSG,
 244                       EXEC_OUTPUT_KMSG_AND_CONSOLE);
 245 }
 246
 247 static bool exec_context_needs_term(const ExecContext *c) {
 248         assert(c);
 249
 250         /* Return true if the execution context suggests we should set $TERM to something useful. */
 251
 252         if (is_terminal_input(c->std_input))
 253                 return true;
 254
 255         if (is_terminal_output(c->std_output))
 256                 return true;
 257
 258         if (is_terminal_output(c->std_error))
 259                 return true;
 260
 261         return !!c->tty_path;
 262 }
 263
 264 static int open_null_as(int flags, int nfd) {
 265         int fd;
 266
 267         assert(nfd >= 0);
 268
 269         fd = open("/dev/null", flags|O_NOCTTY);
 270         if (fd < 0)
 271                 return -errno;
 272
 273         return move_fd(fd, nfd, false);
 274 }
 275
 276 static int connect_journal_socket(int fd, uid_t uid, gid_t gid) {
 277         static const union sockaddr_union sa = {
 278                 .un.sun_family = AF_UNIX,
 279                 .un.sun_path = "/run/systemd/journal/stdout",
 280         };
 281         uid_t olduid = UID_INVALID;
 282         gid_t oldgid = GID_INVALID;
 283         int r;
 284
 285         if (gid_is_valid(gid)) {
 286                 oldgid = getgid();
 287
 288                 if (setegid(gid) < 0)
 289                         return -errno;
 290         }
 291
 292         if (uid_is_valid(uid)) {
 293                 olduid = getuid();
 294
 295                 if (seteuid(uid) < 0) {
 296                         r = -errno;
 297                         goto restore_gid;
 298                 }
 299         }
 300
 301         r = connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0 ? -errno : 0;
 302
 303         /* If we fail to restore the uid or gid, things will likely
 304            fail later on. This should only happen if an LSM interferes. */
 305
 306         if (uid_is_valid(uid))
 307                 (void) seteuid(olduid);
 308
 309  restore_gid:
 310         if (gid_is_valid(gid))
 311                 (void) setegid(oldgid);
 312
 313         return r;
 314 }
 315
 316 static int connect_logger_as(
 317                 const Unit *unit,
 318                 const ExecContext *context,
 319                 const ExecParameters *params,
 320                 ExecOutput output,
 321                 const char *ident,
 322                 int nfd,
 323                 uid_t uid,
 324                 gid_t gid) {
 325
 326         _cleanup_close_ int fd = -1;
 327         int r;
 328
 329         assert(context);
 330         assert(params);
 331         assert(output < _EXEC_OUTPUT_MAX);
 332         assert(ident);
 333         assert(nfd >= 0);
 334
 335         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 336         if (fd < 0)
 337                 return -errno;
 338
 339         r = connect_journal_socket(fd, uid, gid);
 340         if (r < 0)
 341                 return r;
 342
 343         if (shutdown(fd, SHUT_RD) < 0)
 344                 return -errno;
 345
 346         (void) fd_inc_sndbuf(fd, SNDBUF_SIZE);
 347
 348         if (dprintf(fd,
 349                 "%s\n"
 350                 "%s\n"
 351                 "%i\n"
 352                 "%i\n"
 353                 "%i\n"
 354                 "%i\n"
 355                 "%i\n",
 356                 context->syslog_identifier ?: ident,
 357                 params->flags & EXEC_PASS_LOG_UNIT ? unit->id : "",
 358                 context->syslog_priority,
 359                 !!context->syslog_level_prefix,
 360                 is_syslog_output(output),
 361                 is_kmsg_output(output),
 362                 is_terminal_output(output)) < 0)
 363                 return -errno;
 364
 365         return move_fd(TAKE_FD(fd), nfd, false);
 366 }
 367
 368 static int open_terminal_as(const char *path, int flags, int nfd) {
 369         int fd;
 370
 371         assert(path);
 372         assert(nfd >= 0);
 373
 374         fd = open_terminal(path, flags | O_NOCTTY);
 375         if (fd < 0)
 376                 return fd;
 377
 378         return move_fd(fd, nfd, false);
 379 }
 380
 381 static int acquire_path(const char *path, int flags, mode_t mode) {
 382         union sockaddr_union sa = {};
 383         _cleanup_close_ int fd = -1;
 384         int r, salen;
 385
 386         assert(path);
 387
 388         if (IN_SET(flags & O_ACCMODE, O_WRONLY, O_RDWR))
 389                 flags |= O_CREAT;
 390
 391         fd = open(path, flags|O_NOCTTY, mode);
 392         if (fd >= 0)
 393                 return TAKE_FD(fd);
 394
 395         if (errno != ENXIO) /* ENXIO is returned when we try to open() an AF_UNIX file system socket on Linux */
 396                 return -errno;
 397         if (strlen(path) >= sizeof(sa.un.sun_path)) /* Too long, can't be a UNIX socket */
 398                 return -ENXIO;
 399
 400         /* So, it appears the specified path could be an AF_UNIX socket. Let's see if we can connect to it. */
 401
 402         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 403         if (fd < 0)
 404                 return -errno;
 405
 406         salen = sockaddr_un_set_path(&sa.un, path);
 407         if (salen < 0)
 408                 return salen;
 409
 410         if (connect(fd, &sa.sa, salen) < 0)
 411                 return errno == EINVAL ? -ENXIO : -errno; /* Propagate initial error if we get EINVAL, i.e. we have
 412                                                            * indication that his wasn't an AF_UNIX socket after all */
 413
 414         if ((flags & O_ACCMODE) == O_RDONLY)
 415                 r = shutdown(fd, SHUT_WR);
 416         else if ((flags & O_ACCMODE) == O_WRONLY)
 417                 r = shutdown(fd, SHUT_RD);
 418         else
 419                 return TAKE_FD(fd);
 420         if (r < 0)
 421                 return -errno;
 422
 423         return TAKE_FD(fd);
 424 }
 425
 426 static int fixup_input(
 427                 const ExecContext *context,
 428                 int socket_fd,
 429                 bool apply_tty_stdin) {
 430
 431         ExecInput std_input;
 432
 433         assert(context);
 434
 435         std_input = context->std_input;
 436
 437         if (is_terminal_input(std_input) && !apply_tty_stdin)
 438                 return EXEC_INPUT_NULL;
 439
 440         if (std_input == EXEC_INPUT_SOCKET && socket_fd < 0)
 441                 return EXEC_INPUT_NULL;
 442
 443         if (std_input == EXEC_INPUT_DATA && context->stdin_data_size == 0)
 444                 return EXEC_INPUT_NULL;
 445
 446         return std_input;
 447 }
 448
 449 static int fixup_output(ExecOutput std_output, int socket_fd) {
 450
 451         if (std_output == EXEC_OUTPUT_SOCKET && socket_fd < 0)
 452                 return EXEC_OUTPUT_INHERIT;
 453
 454         return std_output;
 455 }
 456
 457 static int setup_input(
 458                 const ExecContext *context,
 459                 const ExecParameters *params,
 460                 int socket_fd,
 461                 int named_iofds[3]) {
 462
 463         ExecInput i;
 464
 465         assert(context);
 466         assert(params);
 467
 468         if (params->stdin_fd >= 0) {
 469                 if (dup2(params->stdin_fd, STDIN_FILENO) < 0)
 470                         return -errno;
 471
 472                 /* Try to make this the controlling tty, if it is a tty, and reset it */
 473                 if (isatty(STDIN_FILENO)) {
 474                         (void) ioctl(STDIN_FILENO, TIOCSCTTY, context->std_input == EXEC_INPUT_TTY_FORCE);
 475                         (void) reset_terminal_fd(STDIN_FILENO, true);
 476                 }
 477
 478                 return STDIN_FILENO;
 479         }
 480
 481         i = fixup_input(context, socket_fd, params->flags & EXEC_APPLY_TTY_STDIN);
 482
 483         switch (i) {
 484
 485         case EXEC_INPUT_NULL:
 486                 return open_null_as(O_RDONLY, STDIN_FILENO);
 487
 488         case EXEC_INPUT_TTY:
 489         case EXEC_INPUT_TTY_FORCE:
 490         case EXEC_INPUT_TTY_FAIL: {
 491                 int fd;
 492
 493                 fd = acquire_terminal(exec_context_tty_path(context),
 494                                       i == EXEC_INPUT_TTY_FAIL  ? ACQUIRE_TERMINAL_TRY :
 495                                       i == EXEC_INPUT_TTY_FORCE ? ACQUIRE_TERMINAL_FORCE :
 496                                                                   ACQUIRE_TERMINAL_WAIT,
 497                                       USEC_INFINITY);
 498                 if (fd < 0)
 499                         return fd;
 500
 501                 return move_fd(fd, STDIN_FILENO, false);
 502         }
 503
 504         case EXEC_INPUT_SOCKET:
 505                 assert(socket_fd >= 0);
 506
 507                 return dup2(socket_fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 508
 509         case EXEC_INPUT_NAMED_FD:
 510                 assert(named_iofds[STDIN_FILENO] >= 0);
 511
 512                 (void) fd_nonblock(named_iofds[STDIN_FILENO], false);
 513                 return dup2(named_iofds[STDIN_FILENO], STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 514
 515         case EXEC_INPUT_DATA: {
 516                 int fd;
 517
 518                 fd = acquire_data_fd(context->stdin_data, context->stdin_data_size, 0);
 519                 if (fd < 0)
 520                         return fd;
 521
 522                 return move_fd(fd, STDIN_FILENO, false);
 523         }
 524
 525         case EXEC_INPUT_FILE: {
 526                 bool rw;
 527                 int fd;
 528
 529                 assert(context->stdio_file[STDIN_FILENO]);
 530
 531                 rw = (context->std_output == EXEC_OUTPUT_FILE && streq_ptr(context->stdio_file[STDIN_FILENO], context->stdio_file[STDOUT_FILENO])) ||
 532                         (context->std_error == EXEC_OUTPUT_FILE && streq_ptr(context->stdio_file[STDIN_FILENO], context->stdio_file[STDERR_FILENO]));
 533
 534                 fd = acquire_path(context->stdio_file[STDIN_FILENO], rw ? O_RDWR : O_RDONLY, 0666 & ~context->umask);
 535                 if (fd < 0)
 536                         return fd;
 537
 538                 return move_fd(fd, STDIN_FILENO, false);
 539         }
 540
 541         default:
 542                 assert_not_reached("Unknown input type");
 543         }
 544 }
 545
 546 static bool can_inherit_stderr_from_stdout(
 547                 const ExecContext *context,
 548                 ExecOutput o,
 549                 ExecOutput e) {
 550
 551         assert(context);
 552
 553         /* Returns true, if given the specified STDERR and STDOUT output we can directly dup() the stdout fd to the
 554          * stderr fd */
 555
 556         if (e == EXEC_OUTPUT_INHERIT)
 557                 return true;
 558         if (e != o)
 559                 return false;
 560
 561         if (e == EXEC_OUTPUT_NAMED_FD)
 562                 return streq_ptr(context->stdio_fdname[STDOUT_FILENO], context->stdio_fdname[STDERR_FILENO]);
 563
 564         if (IN_SET(e, EXEC_OUTPUT_FILE, EXEC_OUTPUT_FILE_APPEND))
 565                 return streq_ptr(context->stdio_file[STDOUT_FILENO], context->stdio_file[STDERR_FILENO]);
 566
 567         return true;
 568 }
 569
 570 static int setup_output(
 571                 const Unit *unit,
 572                 const ExecContext *context,
 573                 const ExecParameters *params,
 574                 int fileno,
 575                 int socket_fd,
 576                 int named_iofds[3],
 577                 const char *ident,
 578                 uid_t uid,
 579                 gid_t gid,
 580                 dev_t *journal_stream_dev,
 581                 ino_t *journal_stream_ino) {
 582
 583         ExecOutput o;
 584         ExecInput i;
 585         int r;
 586
 587         assert(unit);
 588         assert(context);
 589         assert(params);
 590         assert(ident);
 591         assert(journal_stream_dev);
 592         assert(journal_stream_ino);
 593
 594         if (fileno == STDOUT_FILENO && params->stdout_fd >= 0) {
 595
 596                 if (dup2(params->stdout_fd, STDOUT_FILENO) < 0)
 597                         return -errno;
 598
 599                 return STDOUT_FILENO;
 600         }
 601
 602         if (fileno == STDERR_FILENO && params->stderr_fd >= 0) {
 603                 if (dup2(params->stderr_fd, STDERR_FILENO) < 0)
 604                         return -errno;
 605
 606                 return STDERR_FILENO;
 607         }
 608
 609         i = fixup_input(context, socket_fd, params->flags & EXEC_APPLY_TTY_STDIN);
 610         o = fixup_output(context->std_output, socket_fd);
 611
 612         if (fileno == STDERR_FILENO) {
 613                 ExecOutput e;
 614                 e = fixup_output(context->std_error, socket_fd);
 615
 616                 /* This expects the input and output are already set up */
 617
 618                 /* Don't change the stderr file descriptor if we inherit all
 619                  * the way and are not on a tty */
 620                 if (e == EXEC_OUTPUT_INHERIT &&
 621                     o == EXEC_OUTPUT_INHERIT &&
 622                     i == EXEC_INPUT_NULL &&
 623                     !is_terminal_input(context->std_input) &&
 624                     getppid () != 1)
 625                         return fileno;
 626
 627                 /* Duplicate from stdout if possible */
 628                 if (can_inherit_stderr_from_stdout(context, o, e))
 629                         return dup2(STDOUT_FILENO, fileno) < 0 ? -errno : fileno;
 630
 631                 o = e;
 632
 633         } else if (o == EXEC_OUTPUT_INHERIT) {
 634                 /* If input got downgraded, inherit the original value */
 635                 if (i == EXEC_INPUT_NULL && is_terminal_input(context->std_input))
 636                         return open_terminal_as(exec_context_tty_path(context), O_WRONLY, fileno);
 637
 638                 /* If the input is connected to anything that's not a /dev/null or a data fd, inherit that... */
 639                 if (!IN_SET(i, EXEC_INPUT_NULL, EXEC_INPUT_DATA))
 640                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 641
 642                 /* If we are not started from PID 1 we just inherit STDOUT from our parent process. */
 643                 if (getppid() != 1)
 644                         return fileno;
 645
 646                 /* We need to open /dev/null here anew, to get the right access mode. */
 647                 return open_null_as(O_WRONLY, fileno);
 648         }
 649
 650         switch (o) {
 651
 652         case EXEC_OUTPUT_NULL:
 653                 return open_null_as(O_WRONLY, fileno);
 654
 655         case EXEC_OUTPUT_TTY:
 656                 if (is_terminal_input(i))
 657                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 658
 659                 /* We don't reset the terminal if this is just about output */
 660                 return open_terminal_as(exec_context_tty_path(context), O_WRONLY, fileno);
 661
 662         case EXEC_OUTPUT_SYSLOG:
 663         case EXEC_OUTPUT_SYSLOG_AND_CONSOLE:
 664         case EXEC_OUTPUT_KMSG:
 665         case EXEC_OUTPUT_KMSG_AND_CONSOLE:
 666         case EXEC_OUTPUT_JOURNAL:
 667         case EXEC_OUTPUT_JOURNAL_AND_CONSOLE:
 668                 r = connect_logger_as(unit, context, params, o, ident, fileno, uid, gid);
 669                 if (r < 0) {
 670                         log_unit_warning_errno(unit, r, "Failed to connect %s to the journal socket, ignoring: %m", fileno == STDOUT_FILENO ? "stdout" : "stderr");
 671                         r = open_null_as(O_WRONLY, fileno);
 672                 } else {
 673                         struct stat st;
 674
 675                         /* If we connected this fd to the journal via a stream, patch the device/inode into the passed
 676                          * parameters, but only then. This is useful so that we can set $JOURNAL_STREAM that permits
 677                          * services to detect whether they are connected to the journal or not.
 678                          *
 679                          * If both stdout and stderr are connected to a stream then let's make sure to store the data
 680                          * about STDERR as that's usually the best way to do logging. */
 681
 682                         if (fstat(fileno, &st) >= 0 &&
 683                             (*journal_stream_ino == 0 || fileno == STDERR_FILENO)) {
 684                                 *journal_stream_dev = st.st_dev;
 685                                 *journal_stream_ino = st.st_ino;
 686                         }
 687                 }
 688                 return r;
 689
 690         case EXEC_OUTPUT_SOCKET:
 691                 assert(socket_fd >= 0);
 692
 693                 return dup2(socket_fd, fileno) < 0 ? -errno : fileno;
 694
 695         case EXEC_OUTPUT_NAMED_FD:
 696                 assert(named_iofds[fileno] >= 0);
 697
 698                 (void) fd_nonblock(named_iofds[fileno], false);
 699                 return dup2(named_iofds[fileno], fileno) < 0 ? -errno : fileno;
 700
 701         case EXEC_OUTPUT_FILE:
 702         case EXEC_OUTPUT_FILE_APPEND: {
 703                 bool rw;
 704                 int fd, flags;
 705
 706                 assert(context->stdio_file[fileno]);
 707
 708                 rw = context->std_input == EXEC_INPUT_FILE &&
 709                         streq_ptr(context->stdio_file[fileno], context->stdio_file[STDIN_FILENO]);
 710
 711                 if (rw)
 712                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 713
 714                 flags = O_WRONLY;
 715                 if (o == EXEC_OUTPUT_FILE_APPEND)
 716                         flags |= O_APPEND;
 717
 718                 fd = acquire_path(context->stdio_file[fileno], flags, 0666 & ~context->umask);
 719                 if (fd < 0)
 720                         return fd;
 721
 722                 return move_fd(fd, fileno, 0);
 723         }
 724
 725         default:
 726                 assert_not_reached("Unknown error type");
 727         }
 728 }
 729
 730 static int chown_terminal(int fd, uid_t uid) {
 731         struct stat st;
 732
 733         assert(fd >= 0);
 734
 735         /* Before we chown/chmod the TTY, let's ensure this is actually a tty */
 736         if (isatty(fd) < 1)
 737                 return 0;
 738
 739         /* This might fail. What matters are the results. */
 740         (void) fchown(fd, uid, -1);
 741         (void) fchmod(fd, TTY_MODE);
 742
 743         if (fstat(fd, &st) < 0)
 744                 return -errno;
 745
 746         if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE)
 747                 return -EPERM;
 748
 749         return 0;
 750 }
 751
 752 static int setup_confirm_stdio(const char *vc, int *_saved_stdin, int *_saved_stdout) {
 753         _cleanup_close_ int fd = -1, saved_stdin = -1, saved_stdout = -1;
 754         int r;
 755
 756         assert(_saved_stdin);
 757         assert(_saved_stdout);
 758
 759         saved_stdin = fcntl(STDIN_FILENO, F_DUPFD, 3);
 760         if (saved_stdin < 0)
 761                 return -errno;
 762
 763         saved_stdout = fcntl(STDOUT_FILENO, F_DUPFD, 3);
 764         if (saved_stdout < 0)
 765                 return -errno;
 766
 767         fd = acquire_terminal(vc, ACQUIRE_TERMINAL_WAIT, DEFAULT_CONFIRM_USEC);
 768         if (fd < 0)
 769                 return fd;
 770
 771         r = chown_terminal(fd, getuid());
 772         if (r < 0)
 773                 return r;
 774
 775         r = reset_terminal_fd(fd, true);
 776         if (r < 0)
 777                 return r;
 778
 779         r = rearrange_stdio(fd, fd, STDERR_FILENO);
 780         fd = -1;
 781         if (r < 0)
 782                 return r;
 783
 784         *_saved_stdin = saved_stdin;
 785         *_saved_stdout = saved_stdout;
 786
 787         saved_stdin = saved_stdout = -1;
 788
 789         return 0;
 790 }
 791
 792 static void write_confirm_error_fd(int err, int fd, const Unit *u) {
 793         assert(err < 0);
 794
 795         if (err == -ETIMEDOUT)
 796                 dprintf(fd, "Confirmation question timed out for %s, assuming positive response.\n", u->id);
 797         else {
 798                 errno = -err;
 799                 dprintf(fd, "Couldn't ask confirmation for %s: %m, assuming positive response.\n", u->id);
 800         }
 801 }
 802
 803 static void write_confirm_error(int err, const char *vc, const Unit *u) {
 804         _cleanup_close_ int fd = -1;
 805
 806         assert(vc);
 807
 808         fd = open_terminal(vc, O_WRONLY|O_NOCTTY|O_CLOEXEC);
 809         if (fd < 0)
 810                 return;
 811
 812         write_confirm_error_fd(err, fd, u);
 813 }
 814
 815 static int restore_confirm_stdio(int *saved_stdin, int *saved_stdout) {
 816         int r = 0;
 817
 818         assert(saved_stdin);
 819         assert(saved_stdout);
 820
 821         release_terminal();
 822
 823         if (*saved_stdin >= 0)
 824                 if (dup2(*saved_stdin, STDIN_FILENO) < 0)
 825                         r = -errno;
 826
 827         if (*saved_stdout >= 0)
 828                 if (dup2(*saved_stdout, STDOUT_FILENO) < 0)
 829                         r = -errno;
 830
 831         *saved_stdin = safe_close(*saved_stdin);
 832         *saved_stdout = safe_close(*saved_stdout);
 833
 834         return r;
 835 }
 836
 837 enum {
 838         CONFIRM_PRETEND_FAILURE = -1,
 839         CONFIRM_PRETEND_SUCCESS =  0,
 840         CONFIRM_EXECUTE = 1,
 841 };
 842
 843 static int ask_for_confirmation(const char *vc, Unit *u, const char *cmdline) {
 844         int saved_stdout = -1, saved_stdin = -1, r;
 845         _cleanup_free_ char *e = NULL;
 846         char c;
 847
 848         /* For any internal errors, assume a positive response. */
 849         r = setup_confirm_stdio(vc, &saved_stdin, &saved_stdout);
 850         if (r < 0) {
 851                 write_confirm_error(r, vc, u);
 852                 return CONFIRM_EXECUTE;
 853         }
 854
 855         /* confirm_spawn might have been disabled while we were sleeping. */
 856         if (manager_is_confirm_spawn_disabled(u->manager)) {
 857                 r = 1;
 858                 goto restore_stdio;
 859         }
 860
 861         e = ellipsize(cmdline, 60, 100);
 862         if (!e) {
 863                 log_oom();
 864                 r = CONFIRM_EXECUTE;
 865                 goto restore_stdio;
 866         }
 867
 868         for (;;) {
 869                 r = ask_char(&c, "yfshiDjcn", "Execute %s? [y, f, s – h for help] ", e);
 870                 if (r < 0) {
 871                         write_confirm_error_fd(r, STDOUT_FILENO, u);
 872                         r = CONFIRM_EXECUTE;
 873                         goto restore_stdio;
 874                 }
 875
 876                 switch (c) {
 877                 case 'c':
 878                         printf("Resuming normal execution.\n");
 879                         manager_disable_confirm_spawn();
 880                         r = 1;
 881                         break;
 882                 case 'D':
 883                         unit_dump(u, stdout, "  ");
 884                         continue; /* ask again */
 885                 case 'f':
 886                         printf("Failing execution.\n");
 887                         r = CONFIRM_PRETEND_FAILURE;
 888                         break;
 889                 case 'h':
 890                         printf("  c - continue, proceed without asking anymore\n"
 891                                "  D - dump, show the state of the unit\n"
 892                                "  f - fail, don't execute the command and pretend it failed\n"
 893                                "  h - help\n"
 894                                "  i - info, show a short summary of the unit\n"
 895                                "  j - jobs, show jobs that are in progress\n"
 896                                "  s - skip, don't execute the command and pretend it succeeded\n"
 897                                "  y - yes, execute the command\n");
 898                         continue; /* ask again */
 899                 case 'i':
 900                         printf("  Description: %s\n"
 901                                "  Unit:        %s\n"
 902                                "  Command:     %s\n",
 903                                u->id, u->description, cmdline);
 904                         continue; /* ask again */
 905                 case 'j':
 906                         manager_dump_jobs(u->manager, stdout, "  ");
 907                         continue; /* ask again */
 908                 case 'n':
 909                         /* 'n' was removed in favor of 'f'. */
 910                         printf("Didn't understand 'n', did you mean 'f'?\n");
 911                         continue; /* ask again */
 912                 case 's':
 913                         printf("Skipping execution.\n");
 914                         r = CONFIRM_PRETEND_SUCCESS;
 915                         break;
 916                 case 'y':
 917                         r = CONFIRM_EXECUTE;
 918                         break;
 919                 default:
 920                         assert_not_reached("Unhandled choice");
 921                 }
 922                 break;
 923         }
 924
 925 restore_stdio:
 926         restore_confirm_stdio(&saved_stdin, &saved_stdout);
 927         return r;
 928 }
 929
 930 static int get_fixed_user(const ExecContext *c, const char **user,
 931                           uid_t *uid, gid_t *gid,
 932                           const char **home, const char **shell) {
 933         int r;
 934         const char *name;
 935
 936         assert(c);
 937
 938         if (!c->user)
 939                 return 0;
 940
 941         /* Note that we don't set $HOME or $SHELL if they are not particularly enlightening anyway
 942          * (i.e. are "/" or "/bin/nologin"). */
 943
 944         name = c->user;
 945         r = get_user_creds(&name, uid, gid, home, shell, USER_CREDS_CLEAN);
 946         if (r < 0)
 947                 return r;
 948
 949         *user = name;
 950         return 0;
 951 }
 952
 953 static int get_fixed_group(const ExecContext *c, const char **group, gid_t *gid) {
 954         int r;
 955         const char *name;
 956
 957         assert(c);
 958
 959         if (!c->group)
 960                 return 0;
 961
 962         name = c->group;
 963         r = get_group_creds(&name, gid, 0);
 964         if (r < 0)
 965                 return r;
 966
 967         *group = name;
 968         return 0;
 969 }
 970
 971 static int get_supplementary_groups(const ExecContext *c, const char *user,
 972                                     const char *group, gid_t gid,
 973                                     gid_t **supplementary_gids, int *ngids) {
 974         char **i;
 975         int r, k = 0;
 976         int ngroups_max;
 977         bool keep_groups = false;
 978         gid_t *groups = NULL;
 979         _cleanup_free_ gid_t *l_gids = NULL;
 980
 981         assert(c);
 982
 983         /*
 984          * If user is given, then lookup GID and supplementary groups list.
 985          * We avoid NSS lookups for gid=0. Also we have to initialize groups
 986          * here and as early as possible so we keep the list of supplementary
 987          * groups of the caller.
 988          */
 989         if (user && gid_is_valid(gid) && gid != 0) {
 990                 /* First step, initialize groups from /etc/groups */
 991                 if (initgroups(user, gid) < 0)
 992                         return -errno;
 993
 994                 keep_groups = true;
 995         }
 996
 997         if (strv_isempty(c->supplementary_groups))
 998                 return 0;
 999
1000         /*
1001          * If SupplementaryGroups= was passed then NGROUPS_MAX has to
1002          * be positive, otherwise fail.
1003          */
1004         errno = 0;
1005         ngroups_max = (int) sysconf(_SC_NGROUPS_MAX);
1006         if (ngroups_max <= 0) {
1007                 if (errno > 0)
1008                         return -errno;
1009                 else
1010                         return -EOPNOTSUPP; /* For all other values */
1011         }
1012
1013         l_gids = new(gid_t, ngroups_max);
1014         if (!l_gids)
1015                 return -ENOMEM;
1016
1017         if (keep_groups) {
1018                 /*
1019                  * Lookup the list of groups that the user belongs to, we
1020                  * avoid NSS lookups here too for gid=0.
1021                  */
1022                 k = ngroups_max;
1023                 if (getgrouplist(user, gid, l_gids, &k) < 0)
1024                         return -EINVAL;
1025         } else
1026                 k = 0;
1027
1028         STRV_FOREACH(i, c->supplementary_groups) {
1029                 const char *g;
1030
1031                 if (k >= ngroups_max)
1032                         return -E2BIG;
1033
1034                 g = *i;
1035                 r = get_group_creds(&g, l_gids+k, 0);
1036                 if (r < 0)
1037                         return r;
1038
1039                 k++;
1040         }
1041
1042         /*
1043          * Sets ngids to zero to drop all supplementary groups, happens
1044          * when we are under root and SupplementaryGroups= is empty.
1045          */
1046         if (k == 0) {
1047                 *ngids = 0;
1048                 return 0;
1049         }
1050
1051         /* Otherwise get the final list of supplementary groups */
1052         groups = memdup(l_gids, sizeof(gid_t) * k);
1053         if (!groups)
1054                 return -ENOMEM;
1055
1056         *supplementary_gids = groups;
1057         *ngids = k;
1058
1059         groups = NULL;
1060
1061         return 0;
1062 }
1063
1064 static int enforce_groups(gid_t gid, const gid_t *supplementary_gids, int ngids) {
1065         int r;
1066
1067         /* Handle SupplementaryGroups= if it is not empty */
1068         if (ngids > 0) {
1069                 r = maybe_setgroups(ngids, supplementary_gids);
1070                 if (r < 0)
1071                         return r;
1072         }
1073
1074         if (gid_is_valid(gid)) {
1075                 /* Then set our gids */
1076                 if (setresgid(gid, gid, gid) < 0)
1077                         return -errno;
1078         }
1079
1080         return 0;
1081 }
1082
1083 static int enforce_user(const ExecContext *context, uid_t uid) {
1084         assert(context);
1085
1086         if (!uid_is_valid(uid))
1087                 return 0;
1088
1089         /* Sets (but doesn't look up) the uid and make sure we keep the
1090          * capabilities while doing so. */
1091
1092         if (context->capability_ambient_set != 0) {
1093
1094                 /* First step: If we need to keep capabilities but
1095                  * drop privileges we need to make sure we keep our
1096                  * caps, while we drop privileges. */
1097                 if (uid != 0) {
1098                         int sb = context->secure_bits | 1<<SECURE_KEEP_CAPS;
1099
1100                         if (prctl(PR_GET_SECUREBITS) != sb)
1101                                 if (prctl(PR_SET_SECUREBITS, sb) < 0)
1102                                         return -errno;
1103                 }
1104         }
1105
1106         /* Second step: actually set the uids */
1107         if (setresuid(uid, uid, uid) < 0)
1108                 return -errno;
1109
1110         /* At this point we should have all necessary capabilities but
1111            are otherwise a normal user. However, the caps might got
1112            corrupted due to the setresuid() so we need clean them up
1113            later. This is done outside of this call. */
1114
1115         return 0;
1116 }
1117
1118 #if HAVE_PAM
1119
1120 static int null_conv(
1121                 int num_msg,
1122                 const struct pam_message **msg,
1123                 struct pam_response **resp,
1124                 void *appdata_ptr) {
1125
1126         /* We don't support conversations */
1127
1128         return PAM_CONV_ERR;
1129 }
1130
1131 #endif
1132
1133 static int setup_pam(
1134                 const char *name,
1135                 const char *user,
1136                 uid_t uid,
1137                 gid_t gid,
1138                 const char *tty,
1139                 char ***env,
1140                 int fds[], size_t n_fds) {
1141
1142 #if HAVE_PAM
1143
1144         static const struct pam_conv conv = {
1145                 .conv = null_conv,
1146                 .appdata_ptr = NULL
1147         };
1148
1149         _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL;
1150         pam_handle_t *handle = NULL;
1151         sigset_t old_ss;
1152         int pam_code = PAM_SUCCESS, r;
1153         char **nv, **e = NULL;
1154         bool close_session = false;
1155         pid_t pam_pid = 0, parent_pid;
1156         int flags = 0;
1157
1158         assert(name);
1159         assert(user);
1160         assert(env);
1161
1162         /* We set up PAM in the parent process, then fork. The child
1163          * will then stay around until killed via PR_GET_PDEATHSIG or
1164          * systemd via the cgroup logic. It will then remove the PAM
1165          * session again. The parent process will exec() the actual
1166          * daemon. We do things this way to ensure that the main PID
1167          * of the daemon is the one we initially fork()ed. */
1168
1169         r = barrier_create(&barrier);
1170         if (r < 0)
1171                 goto fail;
1172
1173         if (log_get_max_level() < LOG_DEBUG)
1174                 flags |= PAM_SILENT;
1175
1176         pam_code = pam_start(name, user, &conv, &handle);
1177         if (pam_code != PAM_SUCCESS) {
1178                 handle = NULL;
1179                 goto fail;
1180         }
1181
1182         if (!tty) {
1183                 _cleanup_free_ char *q = NULL;
1184
1185                 /* Hmm, so no TTY was explicitly passed, but an fd passed to us directly might be a TTY. Let's figure
1186                  * out if that's the case, and read the TTY off it. */
1187
1188                 if (getttyname_malloc(STDIN_FILENO, &q) >= 0)
1189                         tty = strjoina("/dev/", q);
1190         }
1191
1192         if (tty) {
1193                 pam_code = pam_set_item(handle, PAM_TTY, tty);
1194                 if (pam_code != PAM_SUCCESS)
1195                         goto fail;
1196         }
1197
1198         STRV_FOREACH(nv, *env) {
1199                 pam_code = pam_putenv(handle, *nv);
1200                 if (pam_code != PAM_SUCCESS)
1201                         goto fail;
1202         }
1203
1204         pam_code = pam_acct_mgmt(handle, flags);
1205         if (pam_code != PAM_SUCCESS)
1206                 goto fail;
1207
1208         pam_code = pam_open_session(handle, flags);
1209         if (pam_code != PAM_SUCCESS)
1210                 goto fail;
1211
1212         close_session = true;
1213
1214         e = pam_getenvlist(handle);
1215         if (!e) {
1216                 pam_code = PAM_BUF_ERR;
1217                 goto fail;
1218         }
1219
1220         /* Block SIGTERM, so that we know that it won't get lost in
1221          * the child */
1222
1223         assert_se(sigprocmask_many(SIG_BLOCK, &old_ss, SIGTERM, -1) >= 0);
1224
1225         parent_pid = getpid_cached();
1226
1227         r = safe_fork("(sd-pam)", 0, &pam_pid);
1228         if (r < 0)
1229                 goto fail;
1230         if (r == 0) {
1231                 int sig, ret = EXIT_PAM;
1232
1233                 /* The child's job is to reset the PAM session on
1234                  * termination */
1235                 barrier_set_role(&barrier, BARRIER_CHILD);
1236
1237                 /* Make sure we don't keep open the passed fds in this child. We assume that otherwise only those fds
1238                  * are open here that have been opened by PAM. */
1239                 (void) close_many(fds, n_fds);
1240
1241                 /* Drop privileges - we don't need any to pam_close_session
1242                  * and this will make PR_SET_PDEATHSIG work in most cases.
1243                  * If this fails, ignore the error - but expect sd-pam threads
1244                  * to fail to exit normally */
1245
1246                 r = maybe_setgroups(0, NULL);
1247                 if (r < 0)
1248                         log_warning_errno(r, "Failed to setgroups() in sd-pam: %m");
1249                 if (setresgid(gid, gid, gid) < 0)
1250                         log_warning_errno(errno, "Failed to setresgid() in sd-pam: %m");
1251                 if (setresuid(uid, uid, uid) < 0)
1252                         log_warning_errno(errno, "Failed to setresuid() in sd-pam: %m");
1253
1254                 (void) ignore_signals(SIGPIPE, -1);
1255
1256                 /* Wait until our parent died. This will only work if
1257                  * the above setresuid() succeeds, otherwise the kernel
1258                  * will not allow unprivileged parents kill their privileged
1259                  * children this way. We rely on the control groups kill logic
1260                  * to do the rest for us. */
1261                 if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
1262                         goto child_finish;
1263
1264                 /* Tell the parent that our setup is done. This is especially
1265                  * important regarding dropping privileges. Otherwise, unit
1266                  * setup might race against our setresuid(2) call.
1267                  *
1268                  * If the parent aborted, we'll detect this below, hence ignore
1269                  * return failure here. */
1270                 (void) barrier_place(&barrier);
1271
1272                 /* Check if our parent process might already have died? */
1273                 if (getppid() == parent_pid) {
1274                         sigset_t ss;
1275
1276                         assert_se(sigemptyset(&ss) >= 0);
1277                         assert_se(sigaddset(&ss, SIGTERM) >= 0);
1278
1279                         for (;;) {
1280                                 if (sigwait(&ss, &sig) < 0) {
1281                                         if (errno == EINTR)
1282                                                 continue;
1283
1284                                         goto child_finish;
1285                                 }
1286
1287                                 assert(sig == SIGTERM);
1288                                 break;
1289                         }
1290                 }
1291
1292                 /* If our parent died we'll end the session */
1293                 if (getppid() != parent_pid) {
1294                         pam_code = pam_close_session(handle, flags);
1295                         if (pam_code != PAM_SUCCESS)
1296                                 goto child_finish;
1297                 }
1298
1299                 ret = 0;
1300
1301         child_finish:
1302                 pam_end(handle, pam_code | flags);
1303                 _exit(ret);
1304         }
1305
1306         barrier_set_role(&barrier, BARRIER_PARENT);
1307
1308         /* If the child was forked off successfully it will do all the
1309          * cleanups, so forget about the handle here. */
1310         handle = NULL;
1311
1312         /* Unblock SIGTERM again in the parent */
1313         assert_se(sigprocmask(SIG_SETMASK, &old_ss, NULL) >= 0);
1314
1315         /* We close the log explicitly here, since the PAM modules
1316          * might have opened it, but we don't want this fd around. */
1317         closelog();
1318
1319         /* Synchronously wait for the child to initialize. We don't care for
1320          * errors as we cannot recover. However, warn loudly if it happens. */
1321         if (!barrier_place_and_sync(&barrier))
1322                 log_error("PAM initialization failed");
1323
1324         return strv_free_and_replace(*env, e);
1325
1326 fail:
1327         if (pam_code != PAM_SUCCESS) {
1328                 log_error("PAM failed: %s", pam_strerror(handle, pam_code));
1329                 r = -EPERM;  /* PAM errors do not map to errno */
1330         } else
1331                 log_error_errno(r, "PAM failed: %m");
1332
1333         if (handle) {
1334                 if (close_session)
1335                         pam_code = pam_close_session(handle, flags);
1336
1337                 pam_end(handle, pam_code | flags);
1338         }
1339
1340         strv_free(e);
1341         closelog();
1342
1343         return r;
1344 #else
1345         return 0;
1346 #endif
1347 }
1348
1349 static void rename_process_from_path(const char *path) {
1350         char process_name[11];
1351         const char *p;
1352         size_t l;
1353
1354         /* This resulting string must fit in 10 chars (i.e. the length
1355          * of "/sbin/init") to look pretty in /bin/ps */
1356
1357         p = basename(path);
1358         if (isempty(p)) {
1359                 rename_process("(...)");
1360                 return;
1361         }
1362
1363         l = strlen(p);
1364         if (l > 8) {
1365                 /* The end of the process name is usually more
1366                  * interesting, since the first bit might just be
1367                  * "systemd-" */
1368                 p = p + l - 8;
1369                 l = 8;
1370         }
1371
1372         process_name[0] = '(';
1373         memcpy(process_name+1, p, l);
1374         process_name[1+l] = ')';
1375         process_name[1+l+1] = 0;
1376
1377         rename_process(process_name);
1378 }
1379
1380 static bool context_has_address_families(const ExecContext *c) {
1381         assert(c);
1382
1383         return c->address_families_whitelist ||
1384                 !set_isempty(c->address_families);
1385 }
1386
1387 static bool context_has_syscall_filters(const ExecContext *c) {
1388         assert(c);
1389
1390         return c->syscall_whitelist ||
1391                 !hashmap_isempty(c->syscall_filter);
1392 }
1393
1394 static bool context_has_no_new_privileges(const ExecContext *c) {
1395         assert(c);
1396
1397         if (c->no_new_privileges)
1398                 return true;
1399
1400         if (have_effective_cap(CAP_SYS_ADMIN)) /* if we are privileged, we don't need NNP */
1401                 return false;
1402
1403         /* We need NNP if we have any form of seccomp and are unprivileged */
1404         return context_has_address_families(c) ||
1405                 c->memory_deny_write_execute ||
1406                 c->restrict_realtime ||
1407                 exec_context_restrict_namespaces_set(c) ||
1408                 c->protect_kernel_tunables ||
1409                 c->protect_kernel_modules ||
1410                 c->private_devices ||
1411                 context_has_syscall_filters(c) ||
1412                 !set_isempty(c->syscall_archs) ||
1413                 c->lock_personality;
1414 }
1415
1416 #if HAVE_SECCOMP
1417
1418 static bool skip_seccomp_unavailable(const Unit* u, const char* msg) {
1419
1420         if (is_seccomp_available())
1421                 return false;
1422
1423         log_unit_debug(u, "SECCOMP features not detected in the kernel, skipping %s", msg);
1424         return true;
1425 }
1426
1427 static int apply_syscall_filter(const Unit* u, const ExecContext *c, bool needs_ambient_hack) {
1428         uint32_t negative_action, default_action, action;
1429         int r;
1430
1431         assert(u);
1432         assert(c);
1433
1434         if (!context_has_syscall_filters(c))
1435                 return 0;
1436
1437         if (skip_seccomp_unavailable(u, "SystemCallFilter="))
1438                 return 0;
1439
1440         negative_action = c->syscall_errno == 0 ? SCMP_ACT_KILL : SCMP_ACT_ERRNO(c->syscall_errno);
1441
1442         if (c->syscall_whitelist) {
1443                 default_action = negative_action;
1444                 action = SCMP_ACT_ALLOW;
1445         } else {
1446                 default_action = SCMP_ACT_ALLOW;
1447                 action = negative_action;
1448         }
1449
1450         if (needs_ambient_hack) {
1451                 r = seccomp_filter_set_add(c->syscall_filter, c->syscall_whitelist, syscall_filter_sets + SYSCALL_FILTER_SET_SETUID);
1452                 if (r < 0)
1453                         return r;
1454         }
1455
1456         return seccomp_load_syscall_filter_set_raw(default_action, c->syscall_filter, action, false);
1457 }
1458
1459 static int apply_syscall_archs(const Unit *u, const ExecContext *c) {
1460         assert(u);
1461         assert(c);
1462
1463         if (set_isempty(c->syscall_archs))
1464                 return 0;
1465
1466         if (skip_seccomp_unavailable(u, "SystemCallArchitectures="))
1467                 return 0;
1468
1469         return seccomp_restrict_archs(c->syscall_archs);
1470 }
1471
1472 static int apply_address_families(const Unit* u, const ExecContext *c) {
1473         assert(u);
1474         assert(c);
1475
1476         if (!context_has_address_families(c))
1477                 return 0;
1478
1479         if (skip_seccomp_unavailable(u, "RestrictAddressFamilies="))
1480                 return 0;
1481
1482         return seccomp_restrict_address_families(c->address_families, c->address_families_whitelist);
1483 }
1484
1485 static int apply_memory_deny_write_execute(const Unit* u, const ExecContext *c) {
1486         assert(u);
1487         assert(c);
1488
1489         if (!c->memory_deny_write_execute)
1490                 return 0;
1491
1492         if (skip_seccomp_unavailable(u, "MemoryDenyWriteExecute="))
1493                 return 0;
1494
1495         return seccomp_memory_deny_write_execute();
1496 }
1497
1498 static int apply_restrict_realtime(const Unit* u, const ExecContext *c) {
1499         assert(u);
1500         assert(c);
1501
1502         if (!c->restrict_realtime)
1503                 return 0;
1504
1505         if (skip_seccomp_unavailable(u, "RestrictRealtime="))
1506                 return 0;
1507
1508         return seccomp_restrict_realtime();
1509 }
1510
1511 static int apply_protect_sysctl(const Unit *u, const ExecContext *c) {
1512         assert(u);
1513         assert(c);
1514
1515         /* Turn off the legacy sysctl() system call. Many distributions turn this off while building the kernel, but
1516          * let's protect even those systems where this is left on in the kernel. */
1517
1518         if (!c->protect_kernel_tunables)
1519                 return 0;
1520
1521         if (skip_seccomp_unavailable(u, "ProtectKernelTunables="))
1522                 return 0;
1523
1524         return seccomp_protect_sysctl();
1525 }
1526
1527 static int apply_protect_kernel_modules(const Unit *u, const ExecContext *c) {
1528         assert(u);
1529         assert(c);
1530
1531         /* Turn off module syscalls on ProtectKernelModules=yes */
1532
1533         if (!c->protect_kernel_modules)
1534                 return 0;
1535
1536         if (skip_seccomp_unavailable(u, "ProtectKernelModules="))
1537                 return 0;
1538
1539         return seccomp_load_syscall_filter_set(SCMP_ACT_ALLOW, syscall_filter_sets + SYSCALL_FILTER_SET_MODULE, SCMP_ACT_ERRNO(EPERM), false);
1540 }
1541
1542 static int apply_private_devices(const Unit *u, const ExecContext *c) {
1543         assert(u);
1544         assert(c);
1545
1546         /* If PrivateDevices= is set, also turn off iopl and all @raw-io syscalls. */
1547
1548         if (!c->private_devices)
1549                 return 0;
1550
1551         if (skip_seccomp_unavailable(u, "PrivateDevices="))
1552                 return 0;
1553
1554         return seccomp_load_syscall_filter_set(SCMP_ACT_ALLOW, syscall_filter_sets + SYSCALL_FILTER_SET_RAW_IO, SCMP_ACT_ERRNO(EPERM), false);
1555 }
1556
1557 static int apply_restrict_namespaces(const Unit *u, const ExecContext *c) {
1558         assert(u);
1559         assert(c);
1560
1561         if (!exec_context_restrict_namespaces_set(c))
1562                 return 0;
1563
1564         if (skip_seccomp_unavailable(u, "RestrictNamespaces="))
1565                 return 0;
1566
1567         return seccomp_restrict_namespaces(c->restrict_namespaces);
1568 }
1569
1570 static int apply_lock_personality(const Unit* u, const ExecContext *c) {
1571         unsigned long personality;
1572         int r;
1573
1574         assert(u);
1575         assert(c);
1576
1577         if (!c->lock_personality)
1578                 return 0;
1579
1580         if (skip_seccomp_unavailable(u, "LockPersonality="))
1581                 return 0;
1582
1583         personality = c->personality;
1584
1585         /* If personality is not specified, use either PER_LINUX or PER_LINUX32 depending on what is currently set. */
1586         if (personality == PERSONALITY_INVALID) {
1587
1588                 r = opinionated_personality(&personality);
1589                 if (r < 0)
1590                         return r;
1591         }
1592
1593         return seccomp_lock_personality(personality);
1594 }
1595
1596 #endif
1597
1598 static void do_idle_pipe_dance(int idle_pipe[4]) {
1599         assert(idle_pipe);
1600
1601         idle_pipe[1] = safe_close(idle_pipe[1]);
1602         idle_pipe[2] = safe_close(idle_pipe[2]);
1603
1604         if (idle_pipe[0] >= 0) {
1605                 int r;
1606
1607                 r = fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT_USEC);
1608
1609                 if (idle_pipe[3] >= 0 && r == 0 /* timeout */) {
1610                         ssize_t n;
1611
1612                         /* Signal systemd that we are bored and want to continue. */
1613                         n = write(idle_pipe[3], "x", 1);
1614                         if (n > 0)
1615                                 /* Wait for systemd to react to the signal above. */
1616                                 fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT2_USEC);
1617                 }
1618
1619                 idle_pipe[0] = safe_close(idle_pipe[0]);
1620
1621         }
1622
1623         idle_pipe[3] = safe_close(idle_pipe[3]);
1624 }
1625
1626 static const char *exec_directory_env_name_to_string(ExecDirectoryType t);
1627
1628 static int build_environment(
1629                 const Unit *u,
1630                 const ExecContext *c,
1631                 const ExecParameters *p,
1632                 size_t n_fds,
1633                 const char *home,
1634                 const char *username,
1635                 const char *shell,
1636                 dev_t journal_stream_dev,
1637                 ino_t journal_stream_ino,
1638                 char ***ret) {
1639
1640         _cleanup_strv_free_ char **our_env = NULL;
1641         ExecDirectoryType t;
1642         size_t n_env = 0;
1643         char *x;
1644
1645         assert(u);
1646         assert(c);
1647         assert(p);
1648         assert(ret);
1649
1650         our_env = new0(char*, 14 + _EXEC_DIRECTORY_TYPE_MAX);
1651         if (!our_env)
1652                 return -ENOMEM;
1653
1654         if (n_fds > 0) {
1655                 _cleanup_free_ char *joined = NULL;
1656
1657                 if (asprintf(&x, "LISTEN_PID="PID_FMT, getpid_cached()) < 0)
1658                         return -ENOMEM;
1659                 our_env[n_env++] = x;
1660
1661                 if (asprintf(&x, "LISTEN_FDS=%zu", n_fds) < 0)
1662                         return -ENOMEM;
1663                 our_env[n_env++] = x;
1664
1665                 joined = strv_join(p->fd_names, ":");
1666                 if (!joined)
1667                         return -ENOMEM;
1668
1669                 x = strjoin("LISTEN_FDNAMES=", joined);
1670                 if (!x)
1671                         return -ENOMEM;
1672                 our_env[n_env++] = x;
1673         }
1674
1675         if ((p->flags & EXEC_SET_WATCHDOG) && p->watchdog_usec > 0) {
1676                 if (asprintf(&x, "WATCHDOG_PID="PID_FMT, getpid_cached()) < 0)
1677                         return -ENOMEM;
1678                 our_env[n_env++] = x;
1679
1680                 if (asprintf(&x, "WATCHDOG_USEC="USEC_FMT, p->watchdog_usec) < 0)
1681                         return -ENOMEM;
1682                 our_env[n_env++] = x;
1683         }
1684
1685         /* If this is D-Bus, tell the nss-systemd module, since it relies on being able to use D-Bus look up dynamic
1686          * users via PID 1, possibly dead-locking the dbus daemon. This way it will not use D-Bus to resolve names, but
1687          * check the database directly. */
1688         if (p->flags & EXEC_NSS_BYPASS_BUS) {
1689                 x = strdup("SYSTEMD_NSS_BYPASS_BUS=1");
1690                 if (!x)
1691                         return -ENOMEM;
1692                 our_env[n_env++] = x;
1693         }
1694
1695         if (home) {
1696                 x = strappend("HOME=", home);
1697                 if (!x)
1698                         return -ENOMEM;
1699                 our_env[n_env++] = x;
1700         }
1701
1702         if (username) {
1703                 x = strappend("LOGNAME=", username);
1704                 if (!x)
1705                         return -ENOMEM;
1706                 our_env[n_env++] = x;
1707
1708                 x = strappend("USER=", username);
1709                 if (!x)
1710                         return -ENOMEM;
1711                 our_env[n_env++] = x;
1712         }
1713
1714         if (shell) {
1715                 x = strappend("SHELL=", shell);
1716                 if (!x)
1717                         return -ENOMEM;
1718                 our_env[n_env++] = x;
1719         }
1720
1721         if (!sd_id128_is_null(u->invocation_id)) {
1722                 if (asprintf(&x, "INVOCATION_ID=" SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(u->invocation_id)) < 0)
1723                         return -ENOMEM;
1724
1725                 our_env[n_env++] = x;
1726         }
1727
1728         if (exec_context_needs_term(c)) {
1729                 const char *tty_path, *term = NULL;
1730
1731                 tty_path = exec_context_tty_path(c);
1732
1733                 /* If we are forked off PID 1 and we are supposed to operate on /dev/console, then let's try to inherit
1734                  * the $TERM set for PID 1. This is useful for containers so that the $TERM the container manager
1735                  * passes to PID 1 ends up all the way in the console login shown. */
1736
1737                 if (path_equal(tty_path, "/dev/console") && getppid() == 1)
1738                         term = getenv("TERM");
1739                 if (!term)
1740                         term = default_term_for_tty(tty_path);
1741
1742                 x = strappend("TERM=", term);
1743                 if (!x)
1744                         return -ENOMEM;
1745                 our_env[n_env++] = x;
1746         }
1747
1748         if (journal_stream_dev != 0 && journal_stream_ino != 0) {
1749                 if (asprintf(&x, "JOURNAL_STREAM=" DEV_FMT ":" INO_FMT, journal_stream_dev, journal_stream_ino) < 0)
1750                         return -ENOMEM;
1751
1752                 our_env[n_env++] = x;
1753         }
1754
1755         for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
1756                 _cleanup_free_ char *pre = NULL, *joined = NULL;
1757                 const char *n;
1758
1759                 if (!p->prefix[t])
1760                         continue;
1761
1762                 if (strv_isempty(c->directories[t].paths))
1763                         continue;
1764
1765                 n = exec_directory_env_name_to_string(t);
1766                 if (!n)
1767                         continue;
1768
1769                 pre = strjoin(p->prefix[t], "/");
1770                 if (!pre)
1771                         return -ENOMEM;
1772
1773                 joined = strv_join_prefix(c->directories[t].paths, ":", pre);
1774                 if (!joined)
1775                         return -ENOMEM;
1776
1777                 x = strjoin(n, "=", joined);
1778                 if (!x)
1779                         return -ENOMEM;
1780
1781                 our_env[n_env++] = x;
1782         }
1783
1784         our_env[n_env++] = NULL;
1785         assert(n_env <= 14 + _EXEC_DIRECTORY_TYPE_MAX);
1786
1787         *ret = TAKE_PTR(our_env);
1788
1789         return 0;
1790 }
1791
1792 static int build_pass_environment(const ExecContext *c, char ***ret) {
1793         _cleanup_strv_free_ char **pass_env = NULL;
1794         size_t n_env = 0, n_bufsize = 0;
1795         char **i;
1796
1797         STRV_FOREACH(i, c->pass_environment) {
1798                 _cleanup_free_ char *x = NULL;
1799                 char *v;
1800
1801                 v = getenv(*i);
1802                 if (!v)
1803                         continue;
1804                 x = strjoin(*i, "=", v);
1805                 if (!x)
1806                         return -ENOMEM;
1807
1808                 if (!GREEDY_REALLOC(pass_env, n_bufsize, n_env + 2))
1809                         return -ENOMEM;
1810
1811                 pass_env[n_env++] = TAKE_PTR(x);
1812                 pass_env[n_env] = NULL;
1813         }
1814
1815         *ret = TAKE_PTR(pass_env);
1816
1817         return 0;
1818 }
1819
1820 static bool exec_needs_mount_namespace(
1821                 const ExecContext *context,
1822                 const ExecParameters *params,
1823                 const ExecRuntime *runtime) {
1824
1825         assert(context);
1826         assert(params);
1827
1828         if (context->root_image)
1829                 return true;
1830
1831         if (!strv_isempty(context->read_write_paths) ||
1832             !strv_isempty(context->read_only_paths) ||
1833             !strv_isempty(context->inaccessible_paths))
1834                 return true;
1835
1836         if (context->n_bind_mounts > 0)
1837                 return true;
1838
1839         if (context->n_temporary_filesystems > 0)
1840                 return true;
1841
1842         if (context->mount_flags != 0)
1843                 return true;
1844
1845         if (context->private_tmp && runtime && (runtime->tmp_dir || runtime->var_tmp_dir))
1846                 return true;
1847
1848         if (context->private_devices ||
1849             context->private_mounts ||
1850             context->protect_system != PROTECT_SYSTEM_NO ||
1851             context->protect_home != PROTECT_HOME_NO ||
1852             context->protect_kernel_tunables ||
1853             context->protect_kernel_modules ||
1854             context->protect_control_groups)
1855                 return true;
1856
1857         if (context->root_directory) {
1858                 ExecDirectoryType t;
1859
1860                 if (context->mount_apivfs)
1861                         return true;
1862
1863                 for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
1864                         if (!params->prefix[t])
1865                                 continue;
1866
1867                         if (!strv_isempty(context->directories[t].paths))
1868                                 return true;
1869                 }
1870         }
1871
1872         if (context->dynamic_user &&
1873             (!strv_isempty(context->directories[EXEC_DIRECTORY_STATE].paths) ||
1874              !strv_isempty(context->directories[EXEC_DIRECTORY_CACHE].paths) ||
1875              !strv_isempty(context->directories[EXEC_DIRECTORY_LOGS].paths)))
1876                 return true;
1877
1878         return false;
1879 }
1880
1881 static int setup_private_users(uid_t uid, gid_t gid) {
1882         _cleanup_free_ char *uid_map = NULL, *gid_map = NULL;
1883         _cleanup_close_pair_ int errno_pipe[2] = { -1, -1 };
1884         _cleanup_close_ int unshare_ready_fd = -1;
1885         _cleanup_(sigkill_waitp) pid_t pid = 0;
1886         uint64_t c = 1;
1887         ssize_t n;
1888         int r;
1889
1890         /* Set up a user namespace and map root to root, the selected UID/GID to itself, and everything else to
1891          * nobody. In order to be able to write this mapping we need CAP_SETUID in the original user namespace, which
1892          * we however lack after opening the user namespace. To work around this we fork() a temporary child process,
1893          * which waits for the parent to create the new user namespace while staying in the original namespace. The
1894          * child then writes the UID mapping, under full privileges. The parent waits for the child to finish and
1895          * continues execution normally. */
1896
1897         if (uid != 0 && uid_is_valid(uid)) {
1898                 r = asprintf(&uid_map,
1899                              "0 0 1\n"                      /* Map root → root */
1900                              UID_FMT " " UID_FMT " 1\n",    /* Map $UID → $UID */
1901                              uid, uid);
1902                 if (r < 0)
1903                         return -ENOMEM;
1904         } else {
1905                 uid_map = strdup("0 0 1\n");            /* The case where the above is the same */
1906                 if (!uid_map)
1907                         return -ENOMEM;
1908         }
1909
1910         if (gid != 0 && gid_is_valid(gid)) {
1911                 r = asprintf(&gid_map,
1912                              "0 0 1\n"                      /* Map root → root */
1913                              GID_FMT " " GID_FMT " 1\n",    /* Map $GID → $GID */
1914                              gid, gid);
1915                 if (r < 0)
1916                         return -ENOMEM;
1917         } else {
1918                 gid_map = strdup("0 0 1\n");            /* The case where the above is the same */
1919                 if (!gid_map)
1920                         return -ENOMEM;
1921         }
1922
1923         /* Create a communication channel so that the parent can tell the child when it finished creating the user
1924          * namespace. */
1925         unshare_ready_fd = eventfd(0, EFD_CLOEXEC);
1926         if (unshare_ready_fd < 0)
1927                 return -errno;
1928
1929         /* Create a communication channel so that the child can tell the parent a proper error code in case it
1930          * failed. */
1931         if (pipe2(errno_pipe, O_CLOEXEC) < 0)
1932                 return -errno;
1933
1934         r = safe_fork("(sd-userns)", FORK_RESET_SIGNALS|FORK_DEATHSIG, &pid);
1935         if (r < 0)
1936                 return r;
1937         if (r == 0) {
1938                 _cleanup_close_ int fd = -1;
1939                 const char *a;
1940                 pid_t ppid;
1941
1942                 /* Child process, running in the original user namespace. Let's update the parent's UID/GID map from
1943                  * here, after the parent opened its own user namespace. */
1944
1945                 ppid = getppid();
1946                 errno_pipe[0] = safe_close(errno_pipe[0]);
1947
1948                 /* Wait until the parent unshared the user namespace */
1949                 if (read(unshare_ready_fd, &c, sizeof(c)) < 0) {
1950                         r = -errno;
1951                         goto child_fail;
1952                 }
1953
1954                 /* Disable the setgroups() system call in the child user namespace, for good. */
1955                 a = procfs_file_alloca(ppid, "setgroups");
1956                 fd = open(a, O_WRONLY|O_CLOEXEC);
1957                 if (fd < 0) {
1958                         if (errno != ENOENT) {
1959                                 r = -errno;
1960                                 goto child_fail;
1961                         }
1962
1963                         /* If the file is missing the kernel is too old, let's continue anyway. */
1964                 } else {
1965                         if (write(fd, "deny\n", 5) < 0) {
1966                                 r = -errno;
1967                                 goto child_fail;
1968                         }
1969
1970                         fd = safe_close(fd);
1971                 }
1972
1973                 /* First write the GID map */
1974                 a = procfs_file_alloca(ppid, "gid_map");
1975                 fd = open(a, O_WRONLY|O_CLOEXEC);
1976                 if (fd < 0) {
1977                         r = -errno;
1978                         goto child_fail;
1979                 }
1980                 if (write(fd, gid_map, strlen(gid_map)) < 0) {
1981                         r = -errno;
1982                         goto child_fail;
1983                 }
1984                 fd = safe_close(fd);
1985
1986                 /* The write the UID map */
1987                 a = procfs_file_alloca(ppid, "uid_map");
1988                 fd = open(a, O_WRONLY|O_CLOEXEC);
1989                 if (fd < 0) {
1990                         r = -errno;
1991                         goto child_fail;
1992                 }
1993                 if (write(fd, uid_map, strlen(uid_map)) < 0) {
1994                         r = -errno;
1995                         goto child_fail;
1996                 }
1997
1998                 _exit(EXIT_SUCCESS);
1999
2000         child_fail:
2001                 (void) write(errno_pipe[1], &r, sizeof(r));
2002                 _exit(EXIT_FAILURE);
2003         }
2004
2005         errno_pipe[1] = safe_close(errno_pipe[1]);
2006
2007         if (unshare(CLONE_NEWUSER) < 0)
2008                 return -errno;
2009
2010         /* Let the child know that the namespace is ready now */
2011         if (write(unshare_ready_fd, &c, sizeof(c)) < 0)
2012                 return -errno;
2013
2014         /* Try to read an error code from the child */
2015         n = read(errno_pipe[0], &r, sizeof(r));
2016         if (n < 0)
2017                 return -errno;
2018         if (n == sizeof(r)) { /* an error code was sent to us */
2019                 if (r < 0)
2020                         return r;
2021                 return -EIO;
2022         }
2023         if (n != 0) /* on success we should have read 0 bytes */
2024                 return -EIO;
2025
2026         r = wait_for_terminate_and_check("(sd-userns)", pid, 0);
2027         pid = 0;
2028         if (r < 0)
2029                 return r;
2030         if (r != EXIT_SUCCESS) /* If something strange happened with the child, let's consider this fatal, too */
2031                 return -EIO;
2032
2033         return 0;
2034 }
2035
2036 static int setup_exec_directory(
2037                 const ExecContext *context,
2038                 const ExecParameters *params,
2039                 uid_t uid,
2040                 gid_t gid,
2041                 ExecDirectoryType type,
2042                 int *exit_status) {
2043
2044         static const int exit_status_table[_EXEC_DIRECTORY_TYPE_MAX] = {
2045                 [EXEC_DIRECTORY_RUNTIME] = EXIT_RUNTIME_DIRECTORY,
2046                 [EXEC_DIRECTORY_STATE] = EXIT_STATE_DIRECTORY,
2047                 [EXEC_DIRECTORY_CACHE] = EXIT_CACHE_DIRECTORY,
2048                 [EXEC_DIRECTORY_LOGS] = EXIT_LOGS_DIRECTORY,
2049                 [EXEC_DIRECTORY_CONFIGURATION] = EXIT_CONFIGURATION_DIRECTORY,
2050         };
2051         char **rt;
2052         int r;
2053
2054         assert(context);
2055         assert(params);
2056         assert(type >= 0 && type < _EXEC_DIRECTORY_TYPE_MAX);
2057         assert(exit_status);
2058
2059         if (!params->prefix[type])
2060                 return 0;
2061
2062         if (params->flags & EXEC_CHOWN_DIRECTORIES) {
2063                 if (!uid_is_valid(uid))
2064                         uid = 0;
2065                 if (!gid_is_valid(gid))
2066                         gid = 0;
2067         }
2068
2069         STRV_FOREACH(rt, context->directories[type].paths) {
2070                 _cleanup_free_ char *p = NULL, *pp = NULL;
2071
2072                 p = strjoin(params->prefix[type], "/", *rt);
2073                 if (!p) {
2074                         r = -ENOMEM;
2075                         goto fail;
2076                 }
2077
2078                 r = mkdir_parents_label(p, 0755);
2079                 if (r < 0)
2080                         goto fail;
2081
2082                 if (context->dynamic_user &&
2083                     !IN_SET(type, EXEC_DIRECTORY_RUNTIME, EXEC_DIRECTORY_CONFIGURATION)) {
2084                         _cleanup_free_ char *private_root = NULL;
2085
2086                         /* So, here's one extra complication when dealing with DynamicUser=1 units. In that case we
2087                          * want to avoid leaving a directory around fully accessible that is owned by a dynamic user
2088                          * whose UID is later on reused. To lock this down we use the same trick used by container
2089                          * managers to prohibit host users to get access to files of the same UID in containers: we
2090                          * place everything inside a directory that has an access mode of 0700 and is owned root:root,
2091                          * so that it acts as security boundary for unprivileged host code. We then use fs namespacing
2092                          * to make this directory permeable for the service itself.
2093                          *
2094                          * Specifically: for a service which wants a special directory "foo/" we first create a
2095                          * directory "private/" with access mode 0700 owned by root:root. Then we place "foo" inside of
2096                          * that directory (i.e. "private/foo/"), and make "foo" a symlink to "private/foo". This way,
2097                          * privileged host users can access "foo/" as usual, but unprivileged host users can't look
2098                          * into it. Inside of the namespaceof the container "private/" is replaced by a more liberally
2099                          * accessible tmpfs, into which the host's "private/foo/" is mounted under the same name, thus
2100                          * disabling the access boundary for the service and making sure it only gets access to the
2101                          * dirs it needs but no others. Tricky? Yes, absolutely, but it works!
2102                          *
2103                          * Note that we don't do this for EXEC_DIRECTORY_CONFIGURATION as that's assumed not to be
2104                          * owned by the service itself.
2105                          * Also, note that we don't do this for EXEC_DIRECTORY_RUNTIME as that's often used for sharing
2106                          * files or sockets with other services. */
2107
2108                         private_root = strjoin(params->prefix[type], "/private");
2109                         if (!private_root) {
2110                                 r = -ENOMEM;
2111                                 goto fail;
2112                         }
2113
2114                         /* First set up private root if it doesn't exist yet, with access mode 0700 and owned by root:root */
2115                         r = mkdir_safe_label(private_root, 0700, 0, 0, MKDIR_WARN_MODE);
2116                         if (r < 0)
2117                                 goto fail;
2118
2119                         pp = strjoin(private_root, "/", *rt);
2120                         if (!pp) {
2121                                 r = -ENOMEM;
2122                                 goto fail;
2123                         }
2124
2125                         /* Create all directories between the configured directory and this private root, and mark them 0755 */
2126                         r = mkdir_parents_label(pp, 0755);
2127                         if (r < 0)
2128                                 goto fail;
2129
2130                         if (is_dir(p, false) > 0 &&
2131                             (laccess(pp, F_OK) < 0 && errno == ENOENT)) {
2132
2133                                 /* Hmm, the private directory doesn't exist yet, but the normal one exists? If so, move
2134                                  * it over. Most likely the service has been upgraded from one that didn't use
2135                                  * DynamicUser=1, to one that does. */
2136
2137                                 if (rename(p, pp) < 0) {
2138                                         r = -errno;
2139                                         goto fail;
2140                                 }
2141                         } else {
2142                                 /* Otherwise, create the actual directory for the service */
2143
2144                                 r = mkdir_label(pp, context->directories[type].mode);
2145                                 if (r < 0 && r != -EEXIST)
2146                                         goto fail;
2147                         }
2148
2149                         /* And link it up from the original place */
2150                         r = symlink_idempotent(pp, p, true);
2151                         if (r < 0)
2152                                 goto fail;
2153
2154                         /* Lock down the access mode */
2155                         if (chmod(pp, context->directories[type].mode) < 0) {
2156                                 r = -errno;
2157                                 goto fail;
2158                         }
2159                 } else {
2160                         r = mkdir_label(p, context->directories[type].mode);
2161                         if (r < 0 && r != -EEXIST)
2162                                 goto fail;
2163                         if (r == -EEXIST && !context->dynamic_user)
2164                                 continue;
2165                 }
2166
2167                 /* Don't change the owner of the configuration directory, as in the common case it is not written to by
2168                  * a service, and shall not be writable. */
2169                 if (type == EXEC_DIRECTORY_CONFIGURATION)
2170                         continue;
2171
2172                 /* Then, change the ownership of the whole tree, if necessary */
2173                 r = path_chown_recursive(pp ?: p, uid, gid);
2174                 if (r < 0)
2175                         goto fail;
2176         }
2177
2178         return 0;
2179
2180 fail:
2181         *exit_status = exit_status_table[type];
2182         return r;
2183 }
2184
2185 #if ENABLE_SMACK
2186 static int setup_smack(
2187                 const ExecContext *context,
2188                 const ExecCommand *command) {
2189
2190         int r;
2191
2192         assert(context);
2193         assert(command);
2194
2195         if (context->smack_process_label) {
2196                 r = mac_smack_apply_pid(0, context->smack_process_label);
2197                 if (r < 0)
2198                         return r;
2199         }
2200 #ifdef SMACK_DEFAULT_PROCESS_LABEL
2201         else {
2202                 _cleanup_free_ char *exec_label = NULL;
2203
2204                 r = mac_smack_read(command->path, SMACK_ATTR_EXEC, &exec_label);
2205                 if (r < 0 && !IN_SET(r, -ENODATA, -EOPNOTSUPP))
2206                         return r;
2207
2208                 r = mac_smack_apply_pid(0, exec_label ? : SMACK_DEFAULT_PROCESS_LABEL);
2209                 if (r < 0)
2210                         return r;
2211         }
2212 #endif
2213
2214         return 0;
2215 }
2216 #endif
2217
2218 static int compile_bind_mounts(
2219                 const ExecContext *context,
2220                 const ExecParameters *params,
2221                 BindMount **ret_bind_mounts,
2222                 size_t *ret_n_bind_mounts,
2223                 char ***ret_empty_directories) {
2224
2225         _cleanup_strv_free_ char **empty_directories = NULL;
2226         BindMount *bind_mounts;
2227         size_t n, h = 0, i;
2228         ExecDirectoryType t;
2229         int r;
2230
2231         assert(context);
2232         assert(params);
2233         assert(ret_bind_mounts);
2234         assert(ret_n_bind_mounts);
2235         assert(ret_empty_directories);
2236
2237         n = context->n_bind_mounts;
2238         for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
2239                 if (!params->prefix[t])
2240                         continue;
2241
2242                 n += strv_length(context->directories[t].paths);
2243         }
2244
2245         if (n <= 0) {
2246                 *ret_bind_mounts = NULL;
2247                 *ret_n_bind_mounts = 0;
2248                 *ret_empty_directories = NULL;
2249                 return 0;
2250         }
2251
2252         bind_mounts = new(BindMount, n);
2253         if (!bind_mounts)
2254                 return -ENOMEM;
2255
2256         for (i = 0; i < context->n_bind_mounts; i++) {
2257                 BindMount *item = context->bind_mounts + i;
2258                 char *s, *d;
2259
2260                 s = strdup(item->source);
2261                 if (!s) {
2262                         r = -ENOMEM;
2263                         goto finish;
2264                 }
2265
2266                 d = strdup(item->destination);
2267                 if (!d) {
2268                         free(s);
2269                         r = -ENOMEM;
2270                         goto finish;
2271                 }
2272
2273                 bind_mounts[h++] = (BindMount) {
2274                         .source = s,
2275                         .destination = d,
2276                         .read_only = item->read_only,
2277                         .recursive = item->recursive,
2278                         .ignore_enoent = item->ignore_enoent,
2279                 };
2280         }
2281
2282         for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
2283                 char **suffix;
2284
2285                 if (!params->prefix[t])
2286                         continue;
2287
2288                 if (strv_isempty(context->directories[t].paths))
2289                         continue;
2290
2291                 if (context->dynamic_user &&
2292                     !IN_SET(t, EXEC_DIRECTORY_RUNTIME, EXEC_DIRECTORY_CONFIGURATION) &&
2293                     !(context->root_directory || context->root_image)) {
2294                         char *private_root;
2295
2296                         /* So this is for a dynamic user, and we need to make sure the process can access its own
2297                          * directory. For that we overmount the usually inaccessible "private" subdirectory with a
2298                          * tmpfs that makes it accessible and is empty except for the submounts we do this for. */
2299
2300                         private_root = strjoin(params->prefix[t], "/private");
2301                         if (!private_root) {
2302                                 r = -ENOMEM;
2303                                 goto finish;
2304                         }
2305
2306                         r = strv_consume(&empty_directories, private_root);
2307                         if (r < 0)
2308                                 goto finish;
2309                 }
2310
2311                 STRV_FOREACH(suffix, context->directories[t].paths) {
2312                         char *s, *d;
2313
2314                         if (context->dynamic_user &&
2315                             !IN_SET(t, EXEC_DIRECTORY_RUNTIME, EXEC_DIRECTORY_CONFIGURATION))
2316                                 s = strjoin(params->prefix[t], "/private/", *suffix);
2317                         else
2318                                 s = strjoin(params->prefix[t], "/", *suffix);
2319                         if (!s) {
2320                                 r = -ENOMEM;
2321                                 goto finish;
2322                         }
2323
2324                         if (context->dynamic_user &&
2325                             !IN_SET(t, EXEC_DIRECTORY_RUNTIME, EXEC_DIRECTORY_CONFIGURATION) &&
2326                             (context->root_directory || context->root_image))
2327                                 /* When RootDirectory= or RootImage= are set, then the symbolic link to the private
2328                                  * directory is not created on the root directory. So, let's bind-mount the directory
2329                                  * on the 'non-private' place. */
2330                                 d = strjoin(params->prefix[t], "/", *suffix);
2331                         else
2332                                 d = strdup(s);
2333                         if (!d) {
2334                                 free(s);
2335                                 r = -ENOMEM;
2336                                 goto finish;
2337                         }
2338
2339                         bind_mounts[h++] = (BindMount) {
2340                                 .source = s,
2341                                 .destination = d,
2342                                 .read_only = false,
2343                                 .recursive = true,
2344                                 .ignore_enoent = false,
2345                         };
2346                 }
2347         }
2348
2349         assert(h == n);
2350
2351         *ret_bind_mounts = bind_mounts;
2352         *ret_n_bind_mounts = n;
2353         *ret_empty_directories = TAKE_PTR(empty_directories);
2354
2355         return (int) n;
2356
2357 finish:
2358         bind_mount_free_many(bind_mounts, h);
2359         return r;
2360 }
2361
2362 static int apply_mount_namespace(
2363                 const Unit *u,
2364                 const ExecCommand *command,
2365                 const ExecContext *context,
2366                 const ExecParameters *params,
2367                 const ExecRuntime *runtime) {
2368
2369         _cleanup_strv_free_ char **empty_directories = NULL;
2370         char *tmp = NULL, *var = NULL;
2371         const char *root_dir = NULL, *root_image = NULL;
2372         NamespaceInfo ns_info;
2373         bool needs_sandboxing;
2374         BindMount *bind_mounts = NULL;
2375         size_t n_bind_mounts = 0;
2376         int r;
2377
2378         assert(context);
2379
2380         /* The runtime struct only contains the parent of the private /tmp,
2381          * which is non-accessible to world users. Inside of it there's a /tmp
2382          * that is sticky, and that's the one we want to use here. */
2383
2384         if (context->private_tmp && runtime) {
2385                 if (runtime->tmp_dir)
2386                         tmp = strjoina(runtime->tmp_dir, "/tmp");
2387                 if (runtime->var_tmp_dir)
2388                         var = strjoina(runtime->var_tmp_dir, "/tmp");
2389         }
2390
2391         if (params->flags & EXEC_APPLY_CHROOT) {
2392                 root_image = context->root_image;
2393
2394                 if (!root_image)
2395                         root_dir = context->root_directory;
2396         }
2397
2398         r = compile_bind_mounts(context, params, &bind_mounts, &n_bind_mounts, &empty_directories);
2399         if (r < 0)
2400                 return r;
2401
2402         needs_sandboxing = (params->flags & EXEC_APPLY_SANDBOXING) && !(command->flags & EXEC_COMMAND_FULLY_PRIVILEGED);
2403         if (needs_sandboxing)
2404                 ns_info = (NamespaceInfo) {
2405                         .ignore_protect_paths = false,
2406                         .private_dev = context->private_devices,
2407                         .protect_control_groups = context->protect_control_groups,
2408                         .protect_kernel_tunables = context->protect_kernel_tunables,
2409                         .protect_kernel_modules = context->protect_kernel_modules,
2410                         .mount_apivfs = context->mount_apivfs,
2411                         .private_mounts = context->private_mounts,
2412                 };
2413         else if (!context->dynamic_user && root_dir)
2414                 /*
2415                  * If DynamicUser=no and RootDirectory= is set then lets pass a relaxed
2416                  * sandbox info, otherwise enforce it, don't ignore protected paths and
2417                  * fail if we are enable to apply the sandbox inside the mount namespace.
2418                  */
2419                 ns_info = (NamespaceInfo) {
2420                         .ignore_protect_paths = true,
2421                 };
2422         else
2423                 ns_info = (NamespaceInfo) {};
2424
2425         r = setup_namespace(root_dir, root_image,
2426                             &ns_info, context->read_write_paths,
2427                             needs_sandboxing ? context->read_only_paths : NULL,
2428                             needs_sandboxing ? context->inaccessible_paths : NULL,
2429                             empty_directories,
2430                             bind_mounts,
2431                             n_bind_mounts,
2432                             context->temporary_filesystems,
2433                             context->n_temporary_filesystems,
2434                             tmp,
2435                             var,
2436                             needs_sandboxing ? context->protect_home : PROTECT_HOME_NO,
2437                             needs_sandboxing ? context->protect_system : PROTECT_SYSTEM_NO,
2438                             context->mount_flags,
2439                             DISSECT_IMAGE_DISCARD_ON_LOOP);
2440
2441         bind_mount_free_many(bind_mounts, n_bind_mounts);
2442
2443         /* If we couldn't set up the namespace this is probably due to a missing capability. setup_namespace() reports
2444          * that with a special, recognizable error ENOANO. In this case, silently proceeed, but only if exclusively
2445          * sandboxing options were used, i.e. nothing such as RootDirectory= or BindMount= that would result in a
2446          * completely different execution environment. */
2447         if (r == -ENOANO) {
2448                 if (n_bind_mounts == 0 &&
2449                     context->n_temporary_filesystems == 0 &&
2450                     !root_dir && !root_image &&
2451                     !context->dynamic_user) {
2452                         log_unit_debug(u, "Failed to set up namespace, assuming containerized execution and ignoring.");
2453                         return 0;
2454                 }
2455
2456                 log_unit_debug(u, "Failed to set up namespace, and refusing to continue since the selected namespacing options alter mount environment non-trivially.\n"
2457                                "Bind mounts: %zu, temporary filesystems: %zu, root directory: %s, root image: %s, dynamic user: %s",
2458                                n_bind_mounts, context->n_temporary_filesystems, yes_no(root_dir), yes_no(root_image), yes_no(context->dynamic_user));
2459
2460                 return -EOPNOTSUPP;
2461         }
2462
2463         return r;
2464 }
2465
2466 static int apply_working_directory(
2467                 const ExecContext *context,
2468                 const ExecParameters *params,
2469                 const char *home,
2470                 const bool needs_mount_ns,
2471                 int *exit_status) {
2472
2473         const char *d, *wd;
2474
2475         assert(context);
2476         assert(exit_status);
2477
2478         if (context->working_directory_home) {
2479
2480                 if (!home) {
2481                         *exit_status = EXIT_CHDIR;
2482                         return -ENXIO;
2483                 }
2484
2485                 wd = home;
2486
2487         } else if (context->working_directory)
2488                 wd = context->working_directory;
2489         else
2490                 wd = "/";
2491
2492         if (params->flags & EXEC_APPLY_CHROOT) {
2493                 if (!needs_mount_ns && context->root_directory)
2494                         if (chroot(context->root_directory) < 0) {
2495                                 *exit_status = EXIT_CHROOT;
2496                                 return -errno;
2497                         }
2498
2499                 d = wd;
2500         } else
2501                 d = prefix_roota(context->root_directory, wd);
2502
2503         if (chdir(d) < 0 && !context->working_directory_missing_ok) {
2504                 *exit_status = EXIT_CHDIR;
2505                 return -errno;
2506         }
2507
2508         return 0;
2509 }
2510
2511 static int setup_keyring(
2512                 const Unit *u,
2513                 const ExecContext *context,
2514                 const ExecParameters *p,
2515                 uid_t uid, gid_t gid) {
2516
2517         key_serial_t keyring;
2518         int r = 0;
2519         uid_t saved_uid;
2520         gid_t saved_gid;
2521
2522         assert(u);
2523         assert(context);
2524         assert(p);
2525
2526         /* Let's set up a new per-service "session" kernel keyring for each system service. This has the benefit that
2527          * each service runs with its own keyring shared among all processes of the service, but with no hook-up beyond
2528          * that scope, and in particular no link to the per-UID keyring. If we don't do this the keyring will be
2529          * automatically created on-demand and then linked to the per-UID keyring, by the kernel. The kernel's built-in
2530          * on-demand behaviour is very appropriate for login users, but probably not so much for system services, where
2531          * UIDs are not necessarily specific to a service but reused (at least in the case of UID 0). */
2532
2533         if (context->keyring_mode == EXEC_KEYRING_INHERIT)
2534                 return 0;
2535
2536         /* Acquiring a reference to the user keyring is nasty. We briefly change identity in order to get things set up
2537          * properly by the kernel. If we don't do that then we can't create it atomically, and that sucks for parallel
2538          * execution. This mimics what pam_keyinit does, too. Setting up session keyring, to be owned by the right user
2539          * & group is just as nasty as acquiring a reference to the user keyring. */
2540
2541         saved_uid = getuid();
2542         saved_gid = getgid();
2543
2544         if (gid_is_valid(gid) && gid != saved_gid) {
2545                 if (setregid(gid, -1) < 0)
2546                         return log_unit_error_errno(u, errno, "Failed to change GID for user keyring: %m");
2547         }
2548
2549         if (uid_is_valid(uid) && uid != saved_uid) {
2550                 if (setreuid(uid, -1) < 0) {
2551                         r = log_unit_error_errno(u, errno, "Failed to change UID for user keyring: %m");
2552                         goto out;
2553                 }
2554         }
2555
2556         keyring = keyctl(KEYCTL_JOIN_SESSION_KEYRING, 0, 0, 0, 0);
2557         if (keyring == -1) {
2558                 if (errno == ENOSYS)
2559                         log_unit_debug_errno(u, errno, "Kernel keyring not supported, ignoring.");
2560                 else if (IN_SET(errno, EACCES, EPERM))
2561                         log_unit_debug_errno(u, errno, "Kernel keyring access prohibited, ignoring.");
2562                 else if (errno == EDQUOT)
2563                         log_unit_debug_errno(u, errno, "Out of kernel keyrings to allocate, ignoring.");
2564                 else
2565                         r = log_unit_error_errno(u, errno, "Setting up kernel keyring failed: %m");
2566
2567                 goto out;
2568         }
2569
2570         /* When requested link the user keyring into the session keyring. */
2571         if (context->keyring_mode == EXEC_KEYRING_SHARED) {
2572
2573                 if (keyctl(KEYCTL_LINK,
2574                            KEY_SPEC_USER_KEYRING,
2575                            KEY_SPEC_SESSION_KEYRING, 0, 0) < 0) {
2576                         r = log_unit_error_errno(u, errno, "Failed to link user keyring into session keyring: %m");
2577                         goto out;
2578                 }
2579         }
2580
2581         /* Restore uid/gid back */
2582         if (uid_is_valid(uid) && uid != saved_uid) {
2583                 if (setreuid(saved_uid, -1) < 0) {
2584                         r = log_unit_error_errno(u, errno, "Failed to change UID back for user keyring: %m");
2585                         goto out;
2586                 }
2587         }
2588
2589         if (gid_is_valid(gid) && gid != saved_gid) {
2590                 if (setregid(saved_gid, -1) < 0)
2591                         return log_unit_error_errno(u, errno, "Failed to change GID back for user keyring: %m");
2592         }
2593
2594         /* Populate they keyring with the invocation ID by default, as original saved_uid. */
2595         if (!sd_id128_is_null(u->invocation_id)) {
2596                 key_serial_t key;
2597
2598                 key = add_key("user", "invocation_id", &u->invocation_id, sizeof(u->invocation_id), KEY_SPEC_SESSION_KEYRING);
2599                 if (key == -1)
2600                         log_unit_debug_errno(u, errno, "Failed to add invocation ID to keyring, ignoring: %m");
2601                 else {
2602                         if (keyctl(KEYCTL_SETPERM, key,
2603                                    KEY_POS_VIEW|KEY_POS_READ|KEY_POS_SEARCH|
2604                                    KEY_USR_VIEW|KEY_USR_READ|KEY_USR_SEARCH, 0, 0) < 0)
2605                                 r = log_unit_error_errno(u, errno, "Failed to restrict invocation ID permission: %m");
2606                 }
2607         }
2608
2609 out:
2610         /* Revert back uid & gid for the the last time, and exit */
2611         /* no extra logging, as only the first already reported error matters */
2612         if (getuid() != saved_uid)
2613                 (void) setreuid(saved_uid, -1);
2614
2615         if (getgid() != saved_gid)
2616                 (void) setregid(saved_gid, -1);
2617
2618         return r;
2619 }
2620
2621 static void append_socket_pair(int *array, size_t *n, const int pair[2]) {
2622         assert(array);
2623         assert(n);
2624
2625         if (!pair)
2626                 return;
2627
2628         if (pair[0] >= 0)
2629                 array[(*n)++] = pair[0];
2630         if (pair[1] >= 0)
2631                 array[(*n)++] = pair[1];
2632 }
2633
2634 static int close_remaining_fds(
2635                 const ExecParameters *params,
2636                 const ExecRuntime *runtime,
2637                 const DynamicCreds *dcreds,
2638                 int user_lookup_fd,
2639                 int socket_fd,
2640                 int exec_fd,
2641                 int *fds, size_t n_fds) {
2642
2643         size_t n_dont_close = 0;
2644         int dont_close[n_fds + 12];
2645
2646         assert(params);
2647
2648         if (params->stdin_fd >= 0)
2649                 dont_close[n_dont_close++] = params->stdin_fd;
2650         if (params->stdout_fd >= 0)
2651                 dont_close[n_dont_close++] = params->stdout_fd;
2652         if (params->stderr_fd >= 0)
2653                 dont_close[n_dont_close++] = params->stderr_fd;
2654
2655         if (socket_fd >= 0)
2656                 dont_close[n_dont_close++] = socket_fd;
2657         if (exec_fd >= 0)
2658                 dont_close[n_dont_close++] = exec_fd;
2659         if (n_fds > 0) {
2660                 memcpy(dont_close + n_dont_close, fds, sizeof(int) * n_fds);
2661                 n_dont_close += n_fds;
2662         }
2663
2664         if (runtime)
2665                 append_socket_pair(dont_close, &n_dont_close, runtime->netns_storage_socket);
2666
2667         if (dcreds) {
2668                 if (dcreds->user)
2669                         append_socket_pair(dont_close, &n_dont_close, dcreds->user->storage_socket);
2670                 if (dcreds->group)
2671                         append_socket_pair(dont_close, &n_dont_close, dcreds->group->storage_socket);
2672         }
2673
2674         if (user_lookup_fd >= 0)
2675                 dont_close[n_dont_close++] = user_lookup_fd;
2676
2677         return close_all_fds(dont_close, n_dont_close);
2678 }
2679
2680 static int send_user_lookup(
2681                 Unit *unit,
2682                 int user_lookup_fd,
2683                 uid_t uid,
2684                 gid_t gid) {
2685
2686         assert(unit);
2687
2688         /* Send the resolved UID/GID to PID 1 after we learnt it. We send a single datagram, containing the UID/GID
2689          * data as well as the unit name. Note that we suppress sending this if no user/group to resolve was
2690          * specified. */
2691
2692         if (user_lookup_fd < 0)
2693                 return 0;
2694
2695         if (!uid_is_valid(uid) && !gid_is_valid(gid))
2696                 return 0;
2697
2698         if (writev(user_lookup_fd,
2699                (struct iovec[]) {
2700                            IOVEC_INIT(&uid, sizeof(uid)),
2701                            IOVEC_INIT(&gid, sizeof(gid)),
2702                            IOVEC_INIT_STRING(unit->id) }, 3) < 0)
2703                 return -errno;
2704
2705         return 0;
2706 }
2707
2708 static int acquire_home(const ExecContext *c, uid_t uid, const char** home, char **buf) {
2709         int r;
2710
2711         assert(c);
2712         assert(home);
2713         assert(buf);
2714
2715         /* If WorkingDirectory=~ is set, try to acquire a usable home directory. */
2716
2717         if (*home)
2718                 return 0;
2719
2720         if (!c->working_directory_home)
2721                 return 0;
2722
2723         if (uid == 0) {
2724                 /* Hardcode /root as home directory for UID 0 */
2725                 *home = "/root";
2726                 return 1;
2727         }
2728
2729         r = get_home_dir(buf);
2730         if (r < 0)
2731                 return r;
2732
2733         *home = *buf;
2734         return 1;
2735 }
2736
2737 static int compile_suggested_paths(const ExecContext *c, const ExecParameters *p, char ***ret) {
2738         _cleanup_strv_free_ char ** list = NULL;
2739         ExecDirectoryType t;
2740         int r;
2741
2742         assert(c);
2743         assert(p);
2744         assert(ret);
2745
2746         assert(c->dynamic_user);
2747
2748         /* Compile a list of paths that it might make sense to read the owning UID from to use as initial candidate for
2749          * dynamic UID allocation, in order to save us from doing costly recursive chown()s of the special
2750          * directories. */
2751
2752         for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
2753                 char **i;
2754
2755                 if (t == EXEC_DIRECTORY_CONFIGURATION)
2756                         continue;
2757
2758                 if (!p->prefix[t])
2759                         continue;
2760
2761                 STRV_FOREACH(i, c->directories[t].paths) {
2762                         char *e;
2763
2764                         if (t == EXEC_DIRECTORY_RUNTIME)
2765                                 e = strjoin(p->prefix[t], "/", *i);
2766                         else
2767                                 e = strjoin(p->prefix[t], "/private/", *i);
2768                         if (!e)
2769                                 return -ENOMEM;
2770
2771                         r = strv_consume(&list, e);
2772                         if (r < 0)
2773                                 return r;
2774                 }
2775         }
2776
2777         *ret = TAKE_PTR(list);
2778
2779         return 0;
2780 }
2781
2782 static char *exec_command_line(char **argv);
2783
2784 static int exec_parameters_get_cgroup_path(const ExecParameters *params, char **ret) {
2785         bool using_subcgroup;
2786         char *p;
2787
2788         assert(params);
2789         assert(ret);
2790
2791         if (!params->cgroup_path)
2792                 return -EINVAL;
2793
2794         /* If we are called for a unit where cgroup delegation is on, and the payload created its own populated
2795          * subcgroup (which we expect it to do, after all it asked for delegation), then we cannot place the control
2796          * processes started after the main unit's process in the unit's main cgroup because it is now an inner one,
2797          * and inner cgroups may not contain processes. Hence, if delegation is on, and this is a control process,
2798          * let's use ".control" as subcgroup instead. Note that we do so only for ExecStartPost=, ExecReload=,
2799          * ExecStop=, ExecStopPost=, i.e. for the commands where the main process is already forked. For ExecStartPre=
2800          * this is not necessary, the cgroup is still empty. We distinguish these cases with the EXEC_CONTROL_CGROUP
2801          * flag, which is only passed for the former statements, not for the latter. */
2802
2803         using_subcgroup = FLAGS_SET(params->flags, EXEC_CONTROL_CGROUP|EXEC_CGROUP_DELEGATE|EXEC_IS_CONTROL);
2804         if (using_subcgroup)
2805                 p = strjoin(params->cgroup_path, "/.control");
2806         else
2807                 p = strdup(params->cgroup_path);
2808         if (!p)
2809                 return -ENOMEM;
2810
2811         *ret = p;
2812         return using_subcgroup;
2813 }
2814
2815 static int exec_child(
2816                 Unit *unit,
2817                 const ExecCommand *command,
2818                 const ExecContext *context,
2819                 const ExecParameters *params,
2820                 ExecRuntime *runtime,
2821                 DynamicCreds *dcreds,
2822                 int socket_fd,
2823                 int named_iofds[3],
2824                 int *fds,
2825                 size_t n_socket_fds,
2826                 size_t n_storage_fds,
2827                 char **files_env,
2828                 int user_lookup_fd,
2829                 int *exit_status) {
2830
2831         _cleanup_strv_free_ char **our_env = NULL, **pass_env = NULL, **accum_env = NULL, **final_argv = NULL;
2832         int *fds_with_exec_fd, n_fds_with_exec_fd, r, ngids = 0, exec_fd = -1;
2833         _cleanup_free_ gid_t *supplementary_gids = NULL;
2834         const char *username = NULL, *groupname = NULL;
2835         _cleanup_free_ char *home_buffer = NULL;
2836         const char *home = NULL, *shell = NULL;
2837         dev_t journal_stream_dev = 0;
2838         ino_t journal_stream_ino = 0;
2839         bool needs_sandboxing,          /* Do we need to set up full sandboxing? (i.e. all namespacing, all MAC stuff, caps, yadda yadda */
2840                 needs_setuid,           /* Do we need to do the actual setresuid()/setresgid() calls? */
2841                 needs_mount_namespace,  /* Do we need to set up a mount namespace for this kernel? */
2842                 needs_ambient_hack;     /* Do we need to apply the ambient capabilities hack? */
2843 #if HAVE_SELINUX
2844         _cleanup_free_ char *mac_selinux_context_net = NULL;
2845         bool use_selinux = false;
2846 #endif
2847 #if ENABLE_SMACK
2848         bool use_smack = false;
2849 #endif
2850 #if HAVE_APPARMOR
2851         bool use_apparmor = false;
2852 #endif
2853         uid_t uid = UID_INVALID;
2854         gid_t gid = GID_INVALID;
2855         size_t n_fds;
2856         ExecDirectoryType dt;
2857         int secure_bits;
2858
2859         assert(unit);
2860         assert(command);
2861         assert(context);
2862         assert(params);
2863         assert(exit_status);
2864
2865         rename_process_from_path(command->path);
2866
2867         /* We reset exactly these signals, since they are the
2868          * only ones we set to SIG_IGN in the main daemon. All
2869          * others we leave untouched because we set them to
2870          * SIG_DFL or a valid handler initially, both of which
2871          * will be demoted to SIG_DFL. */
2872         (void) default_signals(SIGNALS_CRASH_HANDLER,
2873                                SIGNALS_IGNORE, -1);
2874
2875         if (context->ignore_sigpipe)
2876                 (void) ignore_signals(SIGPIPE, -1);
2877
2878         r = reset_signal_mask();
2879         if (r < 0) {
2880                 *exit_status = EXIT_SIGNAL_MASK;
2881                 return log_unit_error_errno(unit, r, "Failed to set process signal mask: %m");
2882         }
2883
2884         if (params->idle_pipe)
2885                 do_idle_pipe_dance(params->idle_pipe);
2886
2887         /* Close fds we don't need very early to make sure we don't block init reexecution because it cannot bind its
2888          * sockets. Among the fds we close are the logging fds, and we want to keep them closed, so that we don't have
2889          * any fds open we don't really want open during the transition. In order to make logging work, we switch the
2890          * log subsystem into open_when_needed mode, so that it reopens the logs on every single log call. */
2891
2892         log_forget_fds();
2893         log_set_open_when_needed(true);
2894
2895         /* In case anything used libc syslog(), close this here, too */
2896         closelog();
2897
2898         n_fds = n_socket_fds + n_storage_fds;
2899         r = close_remaining_fds(params, runtime, dcreds, user_lookup_fd, socket_fd, params->exec_fd, fds, n_fds);
2900         if (r < 0) {
2901                 *exit_status = EXIT_FDS;
2902                 return log_unit_error_errno(unit, r, "Failed to close unwanted file descriptors: %m");
2903         }
2904
2905         if (!context->same_pgrp)
2906                 if (setsid() < 0) {
2907                         *exit_status = EXIT_SETSID;
2908                         return log_unit_error_errno(unit, errno, "Failed to create new process session: %m");
2909                 }
2910
2911         exec_context_tty_reset(context, params);
2912
2913         if (unit_shall_confirm_spawn(unit)) {
2914                 const char *vc = params->confirm_spawn;
2915                 _cleanup_free_ char *cmdline = NULL;
2916
2917                 cmdline = exec_command_line(command->argv);
2918                 if (!cmdline) {
2919                         *exit_status = EXIT_MEMORY;
2920                         return log_oom();
2921                 }
2922
2923                 r = ask_for_confirmation(vc, unit, cmdline);
2924                 if (r != CONFIRM_EXECUTE) {
2925                         if (r == CONFIRM_PRETEND_SUCCESS) {
2926                                 *exit_status = EXIT_SUCCESS;
2927                                 return 0;
2928                         }
2929                         *exit_status = EXIT_CONFIRM;
2930                         log_unit_error(unit, "Execution cancelled by the user");
2931                         return -ECANCELED;
2932                 }
2933         }
2934
2935         /* We are about to invoke NSS and PAM modules. Let's tell them what we are doing here, maybe they care. This is
2936          * used by nss-resolve to disable itself when we are about to start systemd-resolved, to avoid deadlocks. Note
2937          * that these env vars do not survive the execve(), which means they really only apply to the PAM and NSS
2938          * invocations themselves. Also note that while we'll only invoke NSS modules involved in user management they
2939          * might internally call into other NSS modules that are involved in hostname resolution, we never know. */
2940         if (setenv("SYSTEMD_ACTIVATION_UNIT", unit->id, true) != 0 ||
2941             setenv("SYSTEMD_ACTIVATION_SCOPE", MANAGER_IS_SYSTEM(unit->manager) ? "system" : "user", true) != 0) {
2942                 *exit_status = EXIT_MEMORY;
2943                 return log_unit_error_errno(unit, errno, "Failed to update environment: %m");
2944         }
2945
2946         if (context->dynamic_user && dcreds) {
2947                 _cleanup_strv_free_ char **suggested_paths = NULL;
2948
2949                 /* On top of that, make sure we bypass our own NSS module nss-systemd comprehensively for any NSS
2950                  * checks, if DynamicUser=1 is used, as we shouldn't create a feedback loop with ourselves here.*/
2951                 if (putenv((char*) "SYSTEMD_NSS_DYNAMIC_BYPASS=1") != 0) {
2952                         *exit_status = EXIT_USER;
2953                         return log_unit_error_errno(unit, errno, "Failed to update environment: %m");
2954                 }
2955
2956                 r = compile_suggested_paths(context, params, &suggested_paths);
2957                 if (r < 0) {
2958                         *exit_status = EXIT_MEMORY;
2959                         return log_oom();
2960                 }
2961
2962                 r = dynamic_creds_realize(dcreds, suggested_paths, &uid, &gid);
2963                 if (r < 0) {
2964                         *exit_status = EXIT_USER;
2965                         if (r == -EILSEQ) {
2966                                 log_unit_error(unit, "Failed to update dynamic user credentials: User or group with specified name already exists.");
2967                                 return -EOPNOTSUPP;
2968                         }
2969                         return log_unit_error_errno(unit, r, "Failed to update dynamic user credentials: %m");
2970                 }
2971
2972                 if (!uid_is_valid(uid)) {
2973                         *exit_status = EXIT_USER;
2974                         log_unit_error(unit, "UID validation failed for \""UID_FMT"\"", uid);
2975                         return -ESRCH;
2976                 }
2977
2978                 if (!gid_is_valid(gid)) {
2979                         *exit_status = EXIT_USER;
2980                         log_unit_error(unit, "GID validation failed for \""GID_FMT"\"", gid);
2981                         return -ESRCH;
2982                 }
2983
2984                 if (dcreds->user)
2985                         username = dcreds->user->name;
2986
2987         } else {
2988                 r = get_fixed_user(context, &username, &uid, &gid, &home, &shell);
2989                 if (r < 0) {
2990                         *exit_status = EXIT_USER;
2991                         return log_unit_error_errno(unit, r, "Failed to determine user credentials: %m");
2992                 }
2993
2994                 r = get_fixed_group(context, &groupname, &gid);
2995                 if (r < 0) {
2996                         *exit_status = EXIT_GROUP;
2997                         return log_unit_error_errno(unit, r, "Failed to determine group credentials: %m");
2998                 }
2999         }
3000
3001         /* Initialize user supplementary groups and get SupplementaryGroups= ones */
3002         r = get_supplementary_groups(context, username, groupname, gid,
3003                                      &supplementary_gids, &ngids);
3004         if (r < 0) {
3005                 *exit_status = EXIT_GROUP;
3006                 return log_unit_error_errno(unit, r, "Failed to determine supplementary groups: %m");
3007         }
3008
3009         r = send_user_lookup(unit, user_lookup_fd, uid, gid);
3010         if (r < 0) {
3011                 *exit_status = EXIT_USER;
3012                 return log_unit_error_errno(unit, r, "Failed to send user credentials to PID1: %m");
3013         }
3014
3015         user_lookup_fd = safe_close(user_lookup_fd);
3016
3017         r = acquire_home(context, uid, &home, &home_buffer);
3018         if (r < 0) {
3019                 *exit_status = EXIT_CHDIR;
3020                 return log_unit_error_errno(unit, r, "Failed to determine $HOME for user: %m");
3021         }
3022
3023         /* If a socket is connected to STDIN/STDOUT/STDERR, we
3024          * must sure to drop O_NONBLOCK */
3025         if (socket_fd >= 0)
3026                 (void) fd_nonblock(socket_fd, false);
3027
3028         /* Journald will try to look-up our cgroup in order to populate _SYSTEMD_CGROUP and _SYSTEMD_UNIT fields.
3029          * Hence we need to migrate to the target cgroup from init.scope before connecting to journald */
3030         if (params->cgroup_path) {
3031                 _cleanup_free_ char *p = NULL;
3032
3033                 r = exec_parameters_get_cgroup_path(params, &p);
3034                 if (r < 0) {
3035                         *exit_status = EXIT_CGROUP;
3036                         return log_unit_error_errno(unit, r, "Failed to acquire cgroup path: %m");
3037                 }
3038
3039                 r = cg_attach_everywhere(params->cgroup_supported, p, 0, NULL, NULL);
3040                 if (r < 0) {
3041                         *exit_status = EXIT_CGROUP;
3042                         return log_unit_error_errno(unit, r, "Failed to attach to cgroup %s: %m", p);
3043                 }
3044         }
3045
3046         r = setup_input(context, params, socket_fd, named_iofds);
3047         if (r < 0) {
3048                 *exit_status = EXIT_STDIN;
3049                 return log_unit_error_errno(unit, r, "Failed to set up standard input: %m");
3050         }
3051
3052         r = setup_output(unit, context, params, STDOUT_FILENO, socket_fd, named_iofds, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
3053         if (r < 0) {
3054                 *exit_status = EXIT_STDOUT;
3055                 return log_unit_error_errno(unit, r, "Failed to set up standard output: %m");
3056         }
3057
3058         r = setup_output(unit, context, params, STDERR_FILENO, socket_fd, named_iofds, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
3059         if (r < 0) {
3060                 *exit_status = EXIT_STDERR;
3061                 return log_unit_error_errno(unit, r, "Failed to set up standard error output: %m");
3062         }
3063
3064         if (context->oom_score_adjust_set) {
3065                 /* When we can't make this change due to EPERM, then let's silently skip over it. User namespaces
3066                  * prohibit write access to this file, and we shouldn't trip up over that. */
3067                 r = set_oom_score_adjust(context->oom_score_adjust);
3068                 if (IN_SET(r, -EPERM, -EACCES))
3069                         log_unit_debug_errno(unit, r, "Failed to adjust OOM setting, assuming containerized execution, ignoring: %m");
3070                 else if (r < 0) {
3071                         *exit_status = EXIT_OOM_ADJUST;
3072                         return log_unit_error_errno(unit, r, "Failed to adjust OOM setting: %m");
3073                 }
3074         }
3075
3076         if (context->nice_set)
3077                 if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
3078                         *exit_status = EXIT_NICE;
3079                         return log_unit_error_errno(unit, errno, "Failed to set up process scheduling priority (nice level): %m");
3080                 }
3081
3082         if (context->cpu_sched_set) {
3083                 struct sched_param param = {
3084                         .sched_priority = context->cpu_sched_priority,
3085                 };
3086
3087                 r = sched_setscheduler(0,
3088                                        context->cpu_sched_policy |
3089                                        (context->cpu_sched_reset_on_fork ?
3090                                         SCHED_RESET_ON_FORK : 0),
3091                                        &param);
3092                 if (r < 0) {
3093                         *exit_status = EXIT_SETSCHEDULER;
3094                         return log_unit_error_errno(unit, errno, "Failed to set up CPU scheduling: %m");
3095                 }
3096         }
3097
3098         if (context->cpuset)
3099                 if (sched_setaffinity(0, CPU_ALLOC_SIZE(context->cpuset_ncpus), context->cpuset) < 0) {
3100                         *exit_status = EXIT_CPUAFFINITY;
3101                         return log_unit_error_errno(unit, errno, "Failed to set up CPU affinity: %m");
3102                 }
3103
3104         if (context->ioprio_set)
3105                 if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {
3106                         *exit_status = EXIT_IOPRIO;
3107                         return log_unit_error_errno(unit, errno, "Failed to set up IO scheduling priority: %m");
3108                 }
3109
3110         if (context->timer_slack_nsec != NSEC_INFINITY)
3111                 if (prctl(PR_SET_TIMERSLACK, context->timer_slack_nsec) < 0) {
3112                         *exit_status = EXIT_TIMERSLACK;
3113                         return log_unit_error_errno(unit, errno, "Failed to set up timer slack: %m");
3114                 }
3115
3116         if (context->personality != PERSONALITY_INVALID) {
3117                 r = safe_personality(context->personality);
3118                 if (r < 0) {
3119                         *exit_status = EXIT_PERSONALITY;
3120                         return log_unit_error_errno(unit, r, "Failed to set up execution domain (personality): %m");
3121                 }
3122         }
3123
3124         if (context->utmp_id)
3125                 utmp_put_init_process(context->utmp_id, getpid_cached(), getsid(0),
3126                                       context->tty_path,
3127                                       context->utmp_mode == EXEC_UTMP_INIT  ? INIT_PROCESS :
3128                                       context->utmp_mode == EXEC_UTMP_LOGIN ? LOGIN_PROCESS :
3129                                       USER_PROCESS,
3130                                       username);
3131
3132         if (context->user) {
3133                 r = chown_terminal(STDIN_FILENO, uid);
3134                 if (r < 0) {
3135                         *exit_status = EXIT_STDIN;
3136                         return log_unit_error_errno(unit, r, "Failed to change ownership of terminal: %m");
3137                 }
3138         }
3139
3140         /* If delegation is enabled we'll pass ownership of the cgroup to the user of the new process. On cgroup v1
3141          * this is only about systemd's own hierarchy, i.e. not the controller hierarchies, simply because that's not
3142          * safe. On cgroup v2 there's only one hierarchy anyway, and delegation is safe there, hence in that case only
3143          * touch a single hierarchy too. */
3144         if (params->cgroup_path && context->user && (params->flags & EXEC_CGROUP_DELEGATE)) {
3145                 r = cg_set_access(SYSTEMD_CGROUP_CONTROLLER, params->cgroup_path, uid, gid);
3146                 if (r < 0) {
3147                         *exit_status = EXIT_CGROUP;
3148                         return log_unit_error_errno(unit, r, "Failed to adjust control group access: %m");
3149                 }
3150         }
3151
3152         for (dt = 0; dt < _EXEC_DIRECTORY_TYPE_MAX; dt++) {
3153                 r = setup_exec_directory(context, params, uid, gid, dt, exit_status);
3154                 if (r < 0)
3155                         return log_unit_error_errno(unit, r, "Failed to set up special execution directory in %s: %m", params->prefix[dt]);
3156         }
3157
3158         r = build_environment(
3159                         unit,
3160                         context,
3161                         params,
3162                         n_fds,
3163                         home,
3164                         username,
3165                         shell,
3166                         journal_stream_dev,
3167                         journal_stream_ino,
3168                         &our_env);
3169         if (r < 0) {
3170                 *exit_status = EXIT_MEMORY;
3171                 return log_oom();
3172         }
3173
3174         r = build_pass_environment(context, &pass_env);
3175         if (r < 0) {
3176                 *exit_status = EXIT_MEMORY;
3177                 return log_oom();
3178         }
3179
3180         accum_env = strv_env_merge(5,
3181                                    params->environment,
3182                                    our_env,
3183                                    pass_env,
3184                                    context->environment,
3185                                    files_env,
3186                                    NULL);
3187         if (!accum_env) {
3188                 *exit_status = EXIT_MEMORY;
3189                 return log_oom();
3190         }
3191         accum_env = strv_env_clean(accum_env);
3192
3193         (void) umask(context->umask);
3194
3195         r = setup_keyring(unit, context, params, uid, gid);
3196         if (r < 0) {
3197                 *exit_status = EXIT_KEYRING;
3198                 return log_unit_error_errno(unit, r, "Failed to set up kernel keyring: %m");
3199         }
3200
3201         /* We need sandboxing if the caller asked us to apply it and the command isn't explicitly excepted from it */
3202         needs_sandboxing = (params->flags & EXEC_APPLY_SANDBOXING) && !(command->flags & EXEC_COMMAND_FULLY_PRIVILEGED);
3203
3204         /* We need the ambient capability hack, if the caller asked us to apply it and the command is marked for it, and the kernel doesn't actually support ambient caps */
3205         needs_ambient_hack = (params->flags & EXEC_APPLY_SANDBOXING) && (command->flags & EXEC_COMMAND_AMBIENT_MAGIC) && !ambient_capabilities_supported();
3206
3207         /* We need setresuid() if the caller asked us to apply sandboxing and the command isn't explicitly excepted from either whole sandboxing or just setresuid() itself, and the ambient hack is not desired */
3208         if (needs_ambient_hack)
3209                 needs_setuid = false;
3210         else
3211                 needs_setuid = (params->flags & EXEC_APPLY_SANDBOXING) && !(command->flags & (EXEC_COMMAND_FULLY_PRIVILEGED|EXEC_COMMAND_NO_SETUID));
3212
3213         if (needs_sandboxing) {
3214                 /* MAC enablement checks need to be done before a new mount ns is created, as they rely on /sys being
3215                  * present. The actual MAC context application will happen later, as late as possible, to avoid
3216                  * impacting our own code paths. */
3217
3218 #if HAVE_SELINUX
3219                 use_selinux = mac_selinux_use();
3220 #endif
3221 #if ENABLE_SMACK
3222                 use_smack = mac_smack_use();
3223 #endif
3224 #if HAVE_APPARMOR
3225                 use_apparmor = mac_apparmor_use();
3226 #endif
3227         }
3228
3229         if (needs_setuid) {
3230                 if (context->pam_name && username) {
3231                         r = setup_pam(context->pam_name, username, uid, gid, context->tty_path, &accum_env, fds, n_fds);
3232                         if (r < 0) {
3233                                 *exit_status = EXIT_PAM;
3234                                 return log_unit_error_errno(unit, r, "Failed to set up PAM session: %m");
3235                         }
3236                 }
3237         }
3238
3239         if (context->private_network && runtime && runtime->netns_storage_socket[0] >= 0) {
3240                 if (ns_type_supported(NAMESPACE_NET)) {
3241                         r = setup_netns(runtime->netns_storage_socket);
3242                         if (r < 0) {
3243                                 *exit_status = EXIT_NETWORK;
3244                                 return log_unit_error_errno(unit, r, "Failed to set up network namespacing: %m");
3245                         }
3246                 } else
3247                         log_unit_warning(unit, "PrivateNetwork=yes is configured, but the kernel does not support network namespaces, ignoring.");
3248         }
3249
3250         needs_mount_namespace = exec_needs_mount_namespace(context, params, runtime);
3251         if (needs_mount_namespace) {
3252                 r = apply_mount_namespace(unit, command, context, params, runtime);
3253                 if (r < 0) {
3254                         *exit_status = EXIT_NAMESPACE;
3255                         return log_unit_error_errno(unit, r, "Failed to set up mount namespacing: %m");
3256                 }
3257         }
3258
3259         /* Drop groups as early as possbile */
3260         if (needs_setuid) {
3261                 r = enforce_groups(gid, supplementary_gids, ngids);
3262                 if (r < 0) {
3263                         *exit_status = EXIT_GROUP;
3264                         return log_unit_error_errno(unit, r, "Changing group credentials failed: %m");
3265                 }
3266         }
3267
3268         if (needs_sandboxing) {
3269 #if HAVE_SELINUX
3270                 if (use_selinux && params->selinux_context_net && socket_fd >= 0) {
3271                         r = mac_selinux_get_child_mls_label(socket_fd, command->path, context->selinux_context, &mac_selinux_context_net);
3272                         if (r < 0) {
3273                                 *exit_status = EXIT_SELINUX_CONTEXT;
3274                                 return log_unit_error_errno(unit, r, "Failed to determine SELinux context: %m");
3275                         }
3276                 }
3277 #endif
3278
3279                 if (context->private_users) {
3280                         r = setup_private_users(uid, gid);
3281                         if (r < 0) {
3282                                 *exit_status = EXIT_USER;
3283                                 return log_unit_error_errno(unit, r, "Failed to set up user namespacing: %m");
3284                         }
3285                 }
3286         }
3287
3288         /* We repeat the fd closing here, to make sure that nothing is leaked from the PAM modules. Note that we are
3289          * more aggressive this time since socket_fd and the netns fds we don't need anymore. We do keep the exec_fd
3290          * however if we have it as we want to keep it open until the final execve(). */
3291
3292         if (params->exec_fd >= 0) {
3293                 exec_fd = params->exec_fd;
3294
3295                 if (exec_fd < 3 + (int) n_fds) {
3296                         int moved_fd;
3297
3298                         /* Let's move the exec fd far up, so that it's outside of the fd range we want to pass to the
3299                          * process we are about to execute. */
3300
3301                         moved_fd = fcntl(exec_fd, F_DUPFD_CLOEXEC, 3 + (int) n_fds);
3302                         if (moved_fd < 0) {
3303                                 *exit_status = EXIT_FDS;
3304                                 return log_unit_error_errno(unit, errno, "Couldn't move exec fd up: %m");
3305                         }
3306
3307                         safe_close(exec_fd);
3308                         exec_fd = moved_fd;
3309                 } else {
3310                         /* This fd should be FD_CLOEXEC already, but let's make sure. */
3311                         r = fd_cloexec(exec_fd, true);
3312                         if (r < 0) {
3313                                 *exit_status = EXIT_FDS;
3314                                 return log_unit_error_errno(unit, r, "Failed to make exec fd FD_CLOEXEC: %m");
3315                         }
3316                 }
3317
3318                 fds_with_exec_fd = newa(int, n_fds + 1);
3319                 memcpy_safe(fds_with_exec_fd, fds, n_fds * sizeof(int));
3320                 fds_with_exec_fd[n_fds] = exec_fd;
3321                 n_fds_with_exec_fd = n_fds + 1;
3322         } else {
3323                 fds_with_exec_fd = fds;
3324                 n_fds_with_exec_fd = n_fds;
3325         }
3326
3327         r = close_all_fds(fds_with_exec_fd, n_fds_with_exec_fd);
3328         if (r >= 0)
3329                 r = shift_fds(fds, n_fds);
3330         if (r >= 0)
3331                 r = flags_fds(fds, n_socket_fds, n_storage_fds, context->non_blocking);
3332         if (r < 0) {
3333                 *exit_status = EXIT_FDS;
3334                 return log_unit_error_errno(unit, r, "Failed to adjust passed file descriptors: %m");
3335         }
3336
3337         /* At this point, the fds we want to pass to the program are all ready and set up, with O_CLOEXEC turned off
3338          * and at the right fd numbers. The are no other fds open, with one exception: the exec_fd if it is defined,
3339          * and it has O_CLOEXEC set, after all we want it to be closed by the execve(), so that our parent knows we
3340          * came this far. */
3341
3342         secure_bits = context->secure_bits;
3343
3344         if (needs_sandboxing) {
3345                 uint64_t bset;
3346                 int which_failed;
3347
3348                 r = setrlimit_closest_all((const struct rlimit* const *) context->rlimit, &which_failed);
3349                 if (r < 0) {
3350                         *exit_status = EXIT_LIMITS;
3351                         return log_unit_error_errno(unit, r, "Failed to adjust resource limit RLIMIT_%s: %m", rlimit_to_string(which_failed));
3352                 }
3353
3354                 /* Set the RTPRIO resource limit to 0, but only if nothing else was explicitly requested. */
3355                 if (context->restrict_realtime && !context->rlimit[RLIMIT_RTPRIO]) {
3356                         if (setrlimit(RLIMIT_RTPRIO, &RLIMIT_MAKE_CONST(0)) < 0) {
3357                                 *exit_status = EXIT_LIMITS;
3358                                 return log_unit_error_errno(unit, errno, "Failed to adjust RLIMIT_RTPRIO resource limit: %m");
3359                         }
3360                 }
3361
3362 #if ENABLE_SMACK
3363                 /* LSM Smack needs the capability CAP_MAC_ADMIN to change the current execution security context of the
3364                  * process. This is the latest place before dropping capabilities. Other MAC context are set later. */
3365                 if (use_smack) {
3366                         r = setup_smack(context, command);
3367                         if (r < 0) {
3368                                 *exit_status = EXIT_SMACK_PROCESS_LABEL;
3369                                 return log_unit_error_errno(unit, r, "Failed to set SMACK process label: %m");
3370                         }
3371                 }
3372 #endif
3373
3374                 bset = context->capability_bounding_set;
3375                 /* If the ambient caps hack is enabled (which means the kernel can't do them, and the user asked for
3376                  * our magic fallback), then let's add some extra caps, so that the service can drop privs of its own,
3377                  * instead of us doing that */
3378                 if (needs_ambient_hack)
3379                         bset |= (UINT64_C(1) << CAP_SETPCAP) |
3380                                 (UINT64_C(1) << CAP_SETUID) |
3381                                 (UINT64_C(1) << CAP_SETGID);
3382
3383                 if (!cap_test_all(bset)) {
3384                         r = capability_bounding_set_drop(bset, false);
3385                         if (r < 0) {
3386                                 *exit_status = EXIT_CAPABILITIES;
3387                                 return log_unit_error_errno(unit, r, "Failed to drop capabilities: %m");
3388                         }
3389                 }
3390
3391                 /* This is done before enforce_user, but ambient set
3392                  * does not survive over setresuid() if keep_caps is not set. */
3393                 if (!needs_ambient_hack &&
3394                     context->capability_ambient_set != 0) {
3395                         r = capability_ambient_set_apply(context->capability_ambient_set, true);
3396                         if (r < 0) {
3397                                 *exit_status = EXIT_CAPABILITIES;
3398                                 return log_unit_error_errno(unit, r, "Failed to apply ambient capabilities (before UID change): %m");
3399                         }
3400                 }
3401         }
3402
3403         if (needs_setuid) {
3404                 if (context->user) {
3405                         r = enforce_user(context, uid);
3406                         if (r < 0) {
3407                                 *exit_status = EXIT_USER;
3408                                 return log_unit_error_errno(unit, r, "Failed to change UID to " UID_FMT ": %m", uid);
3409                         }
3410
3411                         if (!needs_ambient_hack &&
3412                             context->capability_ambient_set != 0) {
3413
3414                                 /* Fix the ambient capabilities after user change. */
3415                                 r = capability_ambient_set_apply(context->capability_ambient_set, false);
3416                                 if (r < 0) {
3417                                         *exit_status = EXIT_CAPABILITIES;
3418                                         return log_unit_error_errno(unit, r, "Failed to apply ambient capabilities (after UID change): %m");
3419                                 }
3420
3421                                 /* If we were asked to change user and ambient capabilities
3422                                  * were requested, we had to add keep-caps to the securebits
3423                                  * so that we would maintain the inherited capability set
3424                                  * through the setresuid(). Make sure that the bit is added
3425                                  * also to the context secure_bits so that we don't try to
3426                                  * drop the bit away next. */
3427
3428                                 secure_bits |= 1<<SECURE_KEEP_CAPS;
3429                         }
3430                 }
3431         }
3432
3433         /* Apply working directory here, because the working directory might be on NFS and only the user running
3434          * this service might have the correct privilege to change to the working directory */
3435         r = apply_working_directory(context, params, home, needs_mount_namespace, exit_status);
3436         if (r < 0)
3437                 return log_unit_error_errno(unit, r, "Changing to the requested working directory failed: %m");
3438
3439         if (needs_sandboxing) {
3440                 /* Apply other MAC contexts late, but before seccomp syscall filtering, as those should really be last to
3441                  * influence our own codepaths as little as possible. Moreover, applying MAC contexts usually requires
3442                  * syscalls that are subject to seccomp filtering, hence should probably be applied before the syscalls
3443                  * are restricted. */
3444
3445 #if HAVE_SELINUX
3446                 if (use_selinux) {
3447                         char *exec_context = mac_selinux_context_net ?: context->selinux_context;
3448
3449                         if (exec_context) {
3450                                 r = setexeccon(exec_context);
3451                                 if (r < 0) {
3452                                         *exit_status = EXIT_SELINUX_CONTEXT;
3453                                         return log_unit_error_errno(unit, r, "Failed to change SELinux context to %s: %m", exec_context);
3454                                 }
3455                         }
3456                 }
3457 #endif
3458
3459 #if HAVE_APPARMOR
3460                 if (use_apparmor && context->apparmor_profile) {
3461                         r = aa_change_onexec(context->apparmor_profile);
3462                         if (r < 0 && !context->apparmor_profile_ignore) {
3463                                 *exit_status = EXIT_APPARMOR_PROFILE;
3464                                 return log_unit_error_errno(unit, errno, "Failed to prepare AppArmor profile change to %s: %m", context->apparmor_profile);
3465                         }
3466                 }
3467 #endif
3468
3469                 /* PR_GET_SECUREBITS is not privileged, while PR_SET_SECUREBITS is. So to suppress potential EPERMs
3470                  * we'll try not to call PR_SET_SECUREBITS unless necessary. */
3471                 if (prctl(PR_GET_SECUREBITS) != secure_bits)
3472                         if (prctl(PR_SET_SECUREBITS, secure_bits) < 0) {
3473                                 *exit_status = EXIT_SECUREBITS;
3474                                 return log_unit_error_errno(unit, errno, "Failed to set process secure bits: %m");
3475                         }
3476
3477                 if (context_has_no_new_privileges(context))
3478                         if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
3479                                 *exit_status = EXIT_NO_NEW_PRIVILEGES;
3480                                 return log_unit_error_errno(unit, errno, "Failed to disable new privileges: %m");
3481                         }
3482
3483 #if HAVE_SECCOMP
3484                 r = apply_address_families(unit, context);
3485                 if (r < 0) {
3486                         *exit_status = EXIT_ADDRESS_FAMILIES;
3487                         return log_unit_error_errno(unit, r, "Failed to restrict address families: %m");
3488                 }
3489
3490                 r = apply_memory_deny_write_execute(unit, context);
3491                 if (r < 0) {
3492                         *exit_status = EXIT_SECCOMP;
3493                         return log_unit_error_errno(unit, r, "Failed to disable writing to executable memory: %m");
3494                 }
3495
3496                 r = apply_restrict_realtime(unit, context);
3497                 if (r < 0) {
3498                         *exit_status = EXIT_SECCOMP;
3499                         return log_unit_error_errno(unit, r, "Failed to apply realtime restrictions: %m");
3500                 }
3501
3502                 r = apply_restrict_namespaces(unit, context);
3503                 if (r < 0) {
3504                         *exit_status = EXIT_SECCOMP;
3505                         return log_unit_error_errno(unit, r, "Failed to apply namespace restrictions: %m");
3506                 }
3507
3508                 r = apply_protect_sysctl(unit, context);
3509                 if (r < 0) {
3510                         *exit_status = EXIT_SECCOMP;
3511                         return log_unit_error_errno(unit, r, "Failed to apply sysctl restrictions: %m");
3512                 }
3513
3514                 r = apply_protect_kernel_modules(unit, context);
3515                 if (r < 0) {
3516                         *exit_status = EXIT_SECCOMP;
3517                         return log_unit_error_errno(unit, r, "Failed to apply module loading restrictions: %m");
3518                 }
3519
3520                 r = apply_private_devices(unit, context);
3521                 if (r < 0) {
3522                         *exit_status = EXIT_SECCOMP;
3523                         return log_unit_error_errno(unit, r, "Failed to set up private devices: %m");
3524                 }
3525
3526                 r = apply_syscall_archs(unit, context);
3527                 if (r < 0) {
3528                         *exit_status = EXIT_SECCOMP;
3529                         return log_unit_error_errno(unit, r, "Failed to apply syscall architecture restrictions: %m");
3530                 }
3531
3532                 r = apply_lock_personality(unit, context);
3533                 if (r < 0) {
3534                         *exit_status = EXIT_SECCOMP;
3535                         return log_unit_error_errno(unit, r, "Failed to lock personalities: %m");
3536                 }
3537
3538                 /* This really should remain the last step before the execve(), to make sure our own code is unaffected
3539                  * by the filter as little as possible. */
3540                 r = apply_syscall_filter(unit, context, needs_ambient_hack);
3541                 if (r < 0) {
3542                         *exit_status = EXIT_SECCOMP;
3543                         return log_unit_error_errno(unit, r, "Failed to apply system call filters: %m");
3544                 }
3545 #endif
3546         }
3547
3548         if (!strv_isempty(context->unset_environment)) {
3549                 char **ee = NULL;
3550
3551                 ee = strv_env_delete(accum_env, 1, context->unset_environment);
3552                 if (!ee) {
3553                         *exit_status = EXIT_MEMORY;
3554                         return log_oom();
3555                 }
3556
3557                 strv_free_and_replace(accum_env, ee);
3558         }
3559
3560         final_argv = replace_env_argv(command->argv, accum_env);
3561         if (!final_argv) {
3562                 *exit_status = EXIT_MEMORY;
3563                 return log_oom();
3564         }
3565
3566         if (DEBUG_LOGGING) {
3567                 _cleanup_free_ char *line;
3568
3569                 line = exec_command_line(final_argv);
3570                 if (line)
3571                         log_struct(LOG_DEBUG,
3572                                    "EXECUTABLE=%s", command->path,
3573                                    LOG_UNIT_MESSAGE(unit, "Executing: %s", line),
3574                                    LOG_UNIT_ID(unit),
3575                                    LOG_UNIT_INVOCATION_ID(unit));
3576         }
3577
3578         if (exec_fd >= 0) {
3579                 uint8_t hot = 1;
3580
3581                 /* We have finished with all our initializations. Let's now let the manager know that. From this point
3582                  * on, if the manager sees POLLHUP on the exec_fd, then execve() was successful. */
3583
3584                 if (write(exec_fd, &hot, sizeof(hot)) < 0) {
3585                         *exit_status = EXIT_EXEC;
3586                         return log_unit_error_errno(unit, errno, "Failed to enable exec_fd: %m");
3587                 }
3588         }
3589
3590         execve(command->path, final_argv, accum_env);
3591         r = -errno;
3592
3593         if (exec_fd >= 0) {
3594                 uint8_t hot = 0;
3595
3596                 /* The execve() failed. This means the exec_fd is still open. Which means we need to tell the manager
3597                  * that POLLHUP on it no longer means execve() succeeded. */
3598
3599                 if (write(exec_fd, &hot, sizeof(hot)) < 0) {
3600                         *exit_status = EXIT_EXEC;
3601                         return log_unit_error_errno(unit, errno, "Failed to disable exec_fd: %m");
3602                 }
3603         }
3604
3605         if (r == -ENOENT && (command->flags & EXEC_COMMAND_IGNORE_FAILURE)) {
3606                 log_struct_errno(LOG_INFO, r,
3607                                  "MESSAGE_ID=" SD_MESSAGE_SPAWN_FAILED_STR,
3608                                  LOG_UNIT_ID(unit),
3609                                  LOG_UNIT_INVOCATION_ID(unit),
3610                                  LOG_UNIT_MESSAGE(unit, "Executable %s missing, skipping: %m",
3611                                                   command->path),
3612                                  "EXECUTABLE=%s", command->path);
3613                 return 0;
3614         }
3615
3616         *exit_status = EXIT_EXEC;
3617         return log_unit_error_errno(unit, r, "Failed to execute command: %m");
3618 }
3619
3620 static int exec_context_load_environment(const Unit *unit, const ExecContext *c, char ***l);
3621 static int exec_context_named_iofds(const ExecContext *c, const ExecParameters *p, int named_iofds[3]);
3622
3623 int exec_spawn(Unit *unit,
3624                ExecCommand *command,
3625                const ExecContext *context,
3626                const ExecParameters *params,
3627                ExecRuntime *runtime,
3628                DynamicCreds *dcreds,
3629                pid_t *ret) {
3630
3631         int socket_fd, r, named_iofds[3] = { -1, -1, -1 }, *fds = NULL;
3632         _cleanup_free_ char *subcgroup_path = NULL;
3633         _cleanup_strv_free_ char **files_env = NULL;
3634         size_t n_storage_fds = 0, n_socket_fds = 0;
3635         _cleanup_free_ char *line = NULL;
3636         pid_t pid;
3637
3638         assert(unit);
3639         assert(command);
3640         assert(context);
3641         assert(ret);
3642         assert(params);
3643         assert(params->fds || (params->n_socket_fds + params->n_storage_fds <= 0));
3644
3645         if (context->std_input == EXEC_INPUT_SOCKET ||
3646             context->std_output == EXEC_OUTPUT_SOCKET ||
3647             context->std_error == EXEC_OUTPUT_SOCKET) {
3648
3649                 if (params->n_socket_fds > 1) {
3650                         log_unit_error(unit, "Got more than one socket.");
3651                         return -EINVAL;
3652                 }
3653
3654                 if (params->n_socket_fds == 0) {
3655                         log_unit_error(unit, "Got no socket.");
3656                         return -EINVAL;
3657                 }
3658
3659                 socket_fd = params->fds[0];
3660         } else {
3661                 socket_fd = -1;
3662                 fds = params->fds;
3663                 n_socket_fds = params->n_socket_fds;
3664                 n_storage_fds = params->n_storage_fds;
3665         }
3666
3667         r = exec_context_named_iofds(context, params, named_iofds);
3668         if (r < 0)
3669                 return log_unit_error_errno(unit, r, "Failed to load a named file descriptor: %m");
3670
3671         r = exec_context_load_environment(unit, context, &files_env);
3672         if (r < 0)
3673                 return log_unit_error_errno(unit, r, "Failed to load environment files: %m");
3674
3675         line = exec_command_line(command->argv);
3676         if (!line)
3677                 return log_oom();
3678
3679         log_struct(LOG_DEBUG,
3680                    LOG_UNIT_MESSAGE(unit, "About to execute: %s", line),
3681                    "EXECUTABLE=%s", command->path,
3682                    LOG_UNIT_ID(unit),
3683                    LOG_UNIT_INVOCATION_ID(unit));
3684
3685         if (params->cgroup_path) {
3686                 r = exec_parameters_get_cgroup_path(params, &subcgroup_path);
3687                 if (r < 0)
3688                         return log_unit_error_errno(unit, r, "Failed to acquire subcgroup path: %m");
3689                 if (r > 0) { /* We are using a child cgroup */
3690                         r = cg_create(SYSTEMD_CGROUP_CONTROLLER, subcgroup_path);
3691                         if (r < 0)
3692                                 return log_unit_error_errno(unit, r, "Failed to create control group '%s': %m", subcgroup_path);
3693                 }
3694         }
3695
3696         pid = fork();
3697         if (pid < 0)
3698                 return log_unit_error_errno(unit, errno, "Failed to fork: %m");
3699
3700         if (pid == 0) {
3701                 int exit_status = EXIT_SUCCESS;
3702
3703                 r = exec_child(unit,
3704                                command,
3705                                context,
3706                                params,
3707                                runtime,
3708                                dcreds,
3709                                socket_fd,
3710                                named_iofds,
3711                                fds,
3712                                n_socket_fds,
3713                                n_storage_fds,
3714                                files_env,
3715                                unit->manager->user_lookup_fds[1],
3716                                &exit_status);
3717
3718                 if (r < 0)
3719                         log_struct_errno(LOG_ERR, r,
3720                                          "MESSAGE_ID=" SD_MESSAGE_SPAWN_FAILED_STR,
3721                                          LOG_UNIT_ID(unit),
3722                                          LOG_UNIT_INVOCATION_ID(unit),
3723                                          LOG_UNIT_MESSAGE(unit, "Failed at step %s spawning %s: %m",
3724                                                           exit_status_to_string(exit_status, EXIT_STATUS_SYSTEMD),
3725                                                           command->path),
3726                                          "EXECUTABLE=%s", command->path);
3727
3728                 _exit(exit_status);
3729         }
3730
3731         log_unit_debug(unit, "Forked %s as "PID_FMT, command->path, pid);
3732
3733         /* We add the new process to the cgroup both in the child (so that we can be sure that no user code is ever
3734          * executed outside of the cgroup) and in the parent (so that we can be sure that when we kill the cgroup the
3735          * process will be killed too). */
3736         if (subcgroup_path)
3737                 (void) cg_attach(SYSTEMD_CGROUP_CONTROLLER, subcgroup_path, pid);
3738
3739         exec_status_start(&command->exec_status, pid);
3740
3741         *ret = pid;
3742         return 0;
3743 }
3744
3745 void exec_context_init(ExecContext *c) {
3746         ExecDirectoryType i;
3747
3748         assert(c);
3749
3750         c->umask = 0022;
3751         c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);
3752         c->cpu_sched_policy = SCHED_OTHER;
3753         c->syslog_priority = LOG_DAEMON|LOG_INFO;
3754         c->syslog_level_prefix = true;
3755         c->ignore_sigpipe = true;
3756         c->timer_slack_nsec = NSEC_INFINITY;
3757         c->personality = PERSONALITY_INVALID;
3758         for (i = 0; i < _EXEC_DIRECTORY_TYPE_MAX; i++)
3759                 c->directories[i].mode = 0755;
3760         c->capability_bounding_set = CAP_ALL;
3761         assert_cc(NAMESPACE_FLAGS_INITIAL != NAMESPACE_FLAGS_ALL);
3762         c->restrict_namespaces = NAMESPACE_FLAGS_INITIAL;
3763         c->log_level_max = -1;
3764 }
3765
3766 void exec_context_done(ExecContext *c) {
3767         ExecDirectoryType i;
3768         size_t l;
3769
3770         assert(c);
3771
3772         c->environment = strv_free(c->environment);
3773         c->environment_files = strv_free(c->environment_files);
3774         c->pass_environment = strv_free(c->pass_environment);
3775         c->unset_environment = strv_free(c->unset_environment);
3776
3777         rlimit_free_all(c->rlimit);
3778
3779         for (l = 0; l < 3; l++) {
3780                 c->stdio_fdname[l] = mfree(c->stdio_fdname[l]);
3781                 c->stdio_file[l] = mfree(c->stdio_file[l]);
3782         }
3783
3784         c->working_directory = mfree(c->working_directory);
3785         c->root_directory = mfree(c->root_directory);
3786         c->root_image = mfree(c->root_image);
3787         c->tty_path = mfree(c->tty_path);
3788         c->syslog_identifier = mfree(c->syslog_identifier);
3789         c->user = mfree(c->user);
3790         c->group = mfree(c->group);
3791
3792         c->supplementary_groups = strv_free(c->supplementary_groups);
3793
3794         c->pam_name = mfree(c->pam_name);
3795
3796         c->read_only_paths = strv_free(c->read_only_paths);
3797         c->read_write_paths = strv_free(c->read_write_paths);
3798         c->inaccessible_paths = strv_free(c->inaccessible_paths);
3799
3800         bind_mount_free_many(c->bind_mounts, c->n_bind_mounts);
3801         c->bind_mounts = NULL;
3802         c->n_bind_mounts = 0;
3803         temporary_filesystem_free_many(c->temporary_filesystems, c->n_temporary_filesystems);
3804         c->temporary_filesystems = NULL;
3805         c->n_temporary_filesystems = 0;
3806
3807         c->cpuset = cpu_set_mfree(c->cpuset);
3808
3809         c->utmp_id = mfree(c->utmp_id);
3810         c->selinux_context = mfree(c->selinux_context);
3811         c->apparmor_profile = mfree(c->apparmor_profile);
3812         c->smack_process_label = mfree(c->smack_process_label);
3813
3814         c->syscall_filter = hashmap_free(c->syscall_filter);
3815         c->syscall_archs = set_free(c->syscall_archs);
3816         c->address_families = set_free(c->address_families);
3817
3818         for (i = 0; i < _EXEC_DIRECTORY_TYPE_MAX; i++)
3819                 c->directories[i].paths = strv_free(c->directories[i].paths);
3820
3821         c->log_level_max = -1;
3822
3823         exec_context_free_log_extra_fields(c);
3824
3825         c->log_rate_limit_interval_usec = 0;
3826         c->log_rate_limit_burst = 0;
3827
3828         c->stdin_data = mfree(c->stdin_data);
3829         c->stdin_data_size = 0;
3830 }
3831
3832 int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_prefix) {
3833         char **i;
3834
3835         assert(c);
3836
3837         if (!runtime_prefix)
3838                 return 0;
3839
3840         STRV_FOREACH(i, c->directories[EXEC_DIRECTORY_RUNTIME].paths) {
3841                 _cleanup_free_ char *p;
3842
3843                 p = strjoin(runtime_prefix, "/", *i);
3844                 if (!p)
3845                         return -ENOMEM;
3846
3847                 /* We execute this synchronously, since we need to be sure this is gone when we start the service
3848                  * next. */
3849                 (void) rm_rf(p, REMOVE_ROOT);
3850         }
3851
3852         return 0;
3853 }
3854
3855 static void exec_command_done(ExecCommand *c) {
3856         assert(c);
3857
3858         c->path = mfree(c->path);
3859         c->argv = strv_free(c->argv);
3860 }
3861
3862 void exec_command_done_array(ExecCommand *c, size_t n) {
3863         size_t i;
3864
3865         for (i = 0; i < n; i++)
3866                 exec_command_done(c+i);
3867 }
3868
3869 ExecCommand* exec_command_free_list(ExecCommand *c) {
3870         ExecCommand *i;
3871
3872         while ((i = c)) {
3873                 LIST_REMOVE(command, c, i);
3874                 exec_command_done(i);
3875                 free(i);
3876         }
3877
3878         return NULL;
3879 }
3880
3881 void exec_command_free_array(ExecCommand **c, size_t n) {
3882         size_t i;
3883
3884         for (i = 0; i < n; i++)
3885                 c[i] = exec_command_free_list(c[i]);
3886 }
3887
3888 void exec_command_reset_status_array(ExecCommand *c, size_t n) {
3889         size_t i;
3890
3891         for (i = 0; i < n; i++)
3892                 exec_status_reset(&c[i].exec_status);
3893 }
3894
3895 void exec_command_reset_status_list_array(ExecCommand **c, size_t n) {
3896         size_t i;
3897
3898         for (i = 0; i < n; i++) {
3899                 ExecCommand *z;
3900
3901                 LIST_FOREACH(command, z, c[i])
3902                         exec_status_reset(&z->exec_status);
3903         }
3904 }
3905
3906 typedef struct InvalidEnvInfo {
3907         const Unit *unit;
3908         const char *path;
3909 } InvalidEnvInfo;
3910
3911 static void invalid_env(const char *p, void *userdata) {
3912         InvalidEnvInfo *info = userdata;
3913
3914         log_unit_error(info->unit, "Ignoring invalid environment assignment '%s': %s", p, info->path);
3915 }
3916
3917 const char* exec_context_fdname(const ExecContext *c, int fd_index) {
3918         assert(c);
3919
3920         switch (fd_index) {
3921
3922         case STDIN_FILENO:
3923                 if (c->std_input != EXEC_INPUT_NAMED_FD)
3924                         return NULL;
3925
3926                 return c->stdio_fdname[STDIN_FILENO] ?: "stdin";
3927
3928         case STDOUT_FILENO:
3929                 if (c->std_output != EXEC_OUTPUT_NAMED_FD)
3930                         return NULL;
3931
3932                 return c->stdio_fdname[STDOUT_FILENO] ?: "stdout";
3933
3934         case STDERR_FILENO:
3935                 if (c->std_error != EXEC_OUTPUT_NAMED_FD)
3936                         return NULL;
3937
3938                 return c->stdio_fdname[STDERR_FILENO] ?: "stderr";
3939
3940         default:
3941                 return NULL;
3942         }
3943 }
3944
3945 static int exec_context_named_iofds(const ExecContext *c, const ExecParameters *p, int named_iofds[3]) {
3946         size_t i, targets;
3947         const char* stdio_fdname[3];
3948         size_t n_fds;
3949
3950         assert(c);
3951         assert(p);
3952
3953         targets = (c->std_input == EXEC_INPUT_NAMED_FD) +
3954                   (c->std_output == EXEC_OUTPUT_NAMED_FD) +
3955                   (c->std_error == EXEC_OUTPUT_NAMED_FD);
3956
3957         for (i = 0; i < 3; i++)
3958                 stdio_fdname[i] = exec_context_fdname(c, i);
3959
3960         n_fds = p->n_storage_fds + p->n_socket_fds;
3961
3962         for (i = 0; i < n_fds  && targets > 0; i++)
3963                 if (named_iofds[STDIN_FILENO] < 0 &&
3964                     c->std_input == EXEC_INPUT_NAMED_FD &&
3965                     stdio_fdname[STDIN_FILENO] &&
3966                     streq(p->fd_names[i], stdio_fdname[STDIN_FILENO])) {
3967
3968                         named_iofds[STDIN_FILENO] = p->fds[i];
3969                         targets--;
3970
3971                 } else if (named_iofds[STDOUT_FILENO] < 0 &&
3972                            c->std_output == EXEC_OUTPUT_NAMED_FD &&
3973                            stdio_fdname[STDOUT_FILENO] &&
3974                            streq(p->fd_names[i], stdio_fdname[STDOUT_FILENO])) {
3975
3976                         named_iofds[STDOUT_FILENO] = p->fds[i];
3977                         targets--;
3978
3979                 } else if (named_iofds[STDERR_FILENO] < 0 &&
3980                            c->std_error == EXEC_OUTPUT_NAMED_FD &&
3981                            stdio_fdname[STDERR_FILENO] &&
3982                            streq(p->fd_names[i], stdio_fdname[STDERR_FILENO])) {
3983
3984                         named_iofds[STDERR_FILENO] = p->fds[i];
3985                         targets--;
3986                 }
3987
3988         return targets == 0 ? 0 : -ENOENT;
3989 }
3990
3991 static int exec_context_load_environment(const Unit *unit, const ExecContext *c, char ***l) {
3992         char **i, **r = NULL;
3993
3994         assert(c);
3995         assert(l);
3996
3997         STRV_FOREACH(i, c->environment_files) {
3998                 char *fn;
3999                 int k;
4000                 unsigned n;
4001                 bool ignore = false;
4002                 char **p;
4003                 _cleanup_globfree_ glob_t pglob = {};
4004
4005                 fn = *i;
4006
4007                 if (fn[0] == '-') {
4008                         ignore = true;
4009                         fn++;
4010                 }
4011
4012                 if (!path_is_absolute(fn)) {
4013                         if (ignore)
4014                                 continue;
4015
4016                         strv_free(r);
4017                         return -EINVAL;
4018                 }
4019
4020                 /* Filename supports globbing, take all matching files */
4021                 k = safe_glob(fn, 0, &pglob);
4022                 if (k < 0) {
4023                         if (ignore)
4024                                 continue;
4025
4026                         strv_free(r);
4027                         return k;
4028                 }
4029
4030                 /* When we don't match anything, -ENOENT should be returned */
4031                 assert(pglob.gl_pathc > 0);
4032
4033                 for (n = 0; n < pglob.gl_pathc; n++) {
4034                         k = load_env_file(NULL, pglob.gl_pathv[n], &p);
4035                         if (k < 0) {
4036                                 if (ignore)
4037                                         continue;
4038
4039                                 strv_free(r);
4040                                 return k;
4041                         }
4042                         /* Log invalid environment variables with filename */
4043                         if (p) {
4044                                 InvalidEnvInfo info = {
4045                                         .unit = unit,
4046                                         .path = pglob.gl_pathv[n]
4047                                 };
4048
4049                                 p = strv_env_clean_with_callback(p, invalid_env, &info);
4050                         }
4051
4052                         if (!r)
4053                                 r = p;
4054                         else {
4055                                 char **m;
4056
4057                                 m = strv_env_merge(2, r, p);
4058                                 strv_free(r);
4059                                 strv_free(p);
4060                                 if (!m)
4061                                         return -ENOMEM;
4062
4063                                 r = m;
4064                         }
4065                 }
4066         }
4067
4068         *l = r;
4069
4070         return 0;
4071 }
4072
4073 static bool tty_may_match_dev_console(const char *tty) {
4074         _cleanup_free_ char *resolved = NULL;
4075
4076         if (!tty)
4077                 return true;
4078
4079         tty = skip_dev_prefix(tty);
4080
4081         /* trivial identity? */
4082         if (streq(tty, "console"))
4083                 return true;
4084
4085         if (resolve_dev_console(&resolved) < 0)
4086                 return true; /* if we could not resolve, assume it may */
4087
4088         /* "tty0" means the active VC, so it may be the same sometimes */
4089         return streq(resolved, tty) || (streq(resolved, "tty0") && tty_is_vc(tty));
4090 }
4091
4092 bool exec_context_may_touch_console(const ExecContext *ec) {
4093
4094         return (ec->tty_reset ||
4095                 ec->tty_vhangup ||
4096                 ec->tty_vt_disallocate ||
4097                 is_terminal_input(ec->std_input) ||
4098                 is_terminal_output(ec->std_output) ||
4099                 is_terminal_output(ec->std_error)) &&
4100                tty_may_match_dev_console(exec_context_tty_path(ec));
4101 }
4102
4103 static void strv_fprintf(FILE *f, char **l) {
4104         char **g;
4105
4106         assert(f);
4107
4108         STRV_FOREACH(g, l)
4109                 fprintf(f, " %s", *g);
4110 }
4111
4112 void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix) {
4113         ExecDirectoryType dt;
4114         char **e, **d;
4115         unsigned i;
4116         int r;
4117
4118         assert(c);
4119         assert(f);
4120
4121         prefix = strempty(prefix);
4122
4123         fprintf(f,
4124                 "%sUMask: %04o\n"
4125                 "%sWorkingDirectory: %s\n"
4126                 "%sRootDirectory: %s\n"
4127                 "%sNonBlocking: %s\n"
4128                 "%sPrivateTmp: %s\n"
4129                 "%sPrivateDevices: %s\n"
4130                 "%sProtectKernelTunables: %s\n"
4131                 "%sProtectKernelModules: %s\n"
4132                 "%sProtectControlGroups: %s\n"
4133                 "%sPrivateNetwork: %s\n"
4134                 "%sPrivateUsers: %s\n"
4135                 "%sProtectHome: %s\n"
4136                 "%sProtectSystem: %s\n"
4137                 "%sMountAPIVFS: %s\n"
4138                 "%sIgnoreSIGPIPE: %s\n"
4139                 "%sMemoryDenyWriteExecute: %s\n"
4140                 "%sRestrictRealtime: %s\n"
4141                 "%sKeyringMode: %s\n",
4142                 prefix, c->umask,
4143                 prefix, c->working_directory ? c->working_directory : "/",
4144                 prefix, c->root_directory ? c->root_directory : "/",
4145                 prefix, yes_no(c->non_blocking),
4146                 prefix, yes_no(c->private_tmp),
4147                 prefix, yes_no(c->private_devices),
4148                 prefix, yes_no(c->protect_kernel_tunables),
4149                 prefix, yes_no(c->protect_kernel_modules),
4150                 prefix, yes_no(c->protect_control_groups),
4151                 prefix, yes_no(c->private_network),
4152                 prefix, yes_no(c->private_users),
4153                 prefix, protect_home_to_string(c->protect_home),
4154                 prefix, protect_system_to_string(c->protect_system),
4155                 prefix, yes_no(c->mount_apivfs),
4156                 prefix, yes_no(c->ignore_sigpipe),
4157                 prefix, yes_no(c->memory_deny_write_execute),
4158                 prefix, yes_no(c->restrict_realtime),
4159                 prefix, exec_keyring_mode_to_string(c->keyring_mode));
4160
4161         if (c->root_image)
4162                 fprintf(f, "%sRootImage: %s\n", prefix, c->root_image);
4163
4164         STRV_FOREACH(e, c->environment)
4165                 fprintf(f, "%sEnvironment: %s\n", prefix, *e);
4166
4167         STRV_FOREACH(e, c->environment_files)
4168                 fprintf(f, "%sEnvironmentFile: %s\n", prefix, *e);
4169
4170         STRV_FOREACH(e, c->pass_environment)
4171                 fprintf(f, "%sPassEnvironment: %s\n", prefix, *e);
4172
4173         STRV_FOREACH(e, c->unset_environment)
4174                 fprintf(f, "%sUnsetEnvironment: %s\n", prefix, *e);
4175
4176         fprintf(f, "%sRuntimeDirectoryPreserve: %s\n", prefix, exec_preserve_mode_to_string(c->runtime_directory_preserve_mode));
4177
4178         for (dt = 0; dt < _EXEC_DIRECTORY_TYPE_MAX; dt++) {
4179                 fprintf(f, "%s%sMode: %04o\n", prefix, exec_directory_type_to_string(dt), c->directories[dt].mode);
4180
4181                 STRV_FOREACH(d, c->directories[dt].paths)
4182                         fprintf(f, "%s%s: %s\n", prefix, exec_directory_type_to_string(dt), *d);
4183         }
4184
4185         if (c->nice_set)
4186                 fprintf(f,
4187                         "%sNice: %i\n",
4188                         prefix, c->nice);
4189
4190         if (c->oom_score_adjust_set)
4191                 fprintf(f,
4192                         "%sOOMScoreAdjust: %i\n",
4193                         prefix, c->oom_score_adjust);
4194
4195         for (i = 0; i < RLIM_NLIMITS; i++)
4196                 if (c->rlimit[i]) {
4197                         fprintf(f, "%sLimit%s: " RLIM_FMT "\n",
4198                                 prefix, rlimit_to_string(i), c->rlimit[i]->rlim_max);
4199                         fprintf(f, "%sLimit%sSoft: " RLIM_FMT "\n",
4200                                 prefix, rlimit_to_string(i), c->rlimit[i]->rlim_cur);
4201                 }
4202
4203         if (c->ioprio_set) {
4204                 _cleanup_free_ char *class_str = NULL;
4205
4206                 r = ioprio_class_to_string_alloc(IOPRIO_PRIO_CLASS(c->ioprio), &class_str);
4207                 if (r >= 0)
4208                         fprintf(f, "%sIOSchedulingClass: %s\n", prefix, class_str);
4209
4210                 fprintf(f, "%sIOPriority: %lu\n", prefix, IOPRIO_PRIO_DATA(c->ioprio));
4211         }
4212
4213         if (c->cpu_sched_set) {
4214                 _cleanup_free_ char *policy_str = NULL;
4215
4216                 r = sched_policy_to_string_alloc(c->cpu_sched_policy, &policy_str);
4217                 if (r >= 0)
4218                         fprintf(f, "%sCPUSchedulingPolicy: %s\n", prefix, policy_str);
4219
4220                 fprintf(f,
4221                         "%sCPUSchedulingPriority: %i\n"
4222                         "%sCPUSchedulingResetOnFork: %s\n",
4223                         prefix, c->cpu_sched_priority,
4224                         prefix, yes_no(c->cpu_sched_reset_on_fork));
4225         }
4226
4227         if (c->cpuset) {
4228                 fprintf(f, "%sCPUAffinity:", prefix);
4229                 for (i = 0; i < c->cpuset_ncpus; i++)
4230                         if (CPU_ISSET_S(i, CPU_ALLOC_SIZE(c->cpuset_ncpus), c->cpuset))
4231                                 fprintf(f, " %u", i);
4232                 fputs("\n", f);
4233         }
4234
4235         if (c->timer_slack_nsec != NSEC_INFINITY)
4236                 fprintf(f, "%sTimerSlackNSec: "NSEC_FMT "\n", prefix, c->timer_slack_nsec);
4237
4238         fprintf(f,
4239                 "%sStandardInput: %s\n"
4240                 "%sStandardOutput: %s\n"
4241                 "%sStandardError: %s\n",
4242                 prefix, exec_input_to_string(c->std_input),
4243                 prefix, exec_output_to_string(c->std_output),
4244                 prefix, exec_output_to_string(c->std_error));
4245
4246         if (c->std_input == EXEC_INPUT_NAMED_FD)
4247                 fprintf(f, "%sStandardInputFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDIN_FILENO]);
4248         if (c->std_output == EXEC_OUTPUT_NAMED_FD)
4249                 fprintf(f, "%sStandardOutputFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDOUT_FILENO]);
4250         if (c->std_error == EXEC_OUTPUT_NAMED_FD)
4251                 fprintf(f, "%sStandardErrorFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDERR_FILENO]);
4252
4253         if (c->std_input == EXEC_INPUT_FILE)
4254                 fprintf(f, "%sStandardInputFile: %s\n", prefix, c->stdio_file[STDIN_FILENO]);
4255         if (c->std_output == EXEC_OUTPUT_FILE)
4256                 fprintf(f, "%sStandardOutputFile: %s\n", prefix, c->stdio_file[STDOUT_FILENO]);
4257         if (c->std_output == EXEC_OUTPUT_FILE_APPEND)
4258                 fprintf(f, "%sStandardOutputFileToAppend: %s\n", prefix, c->stdio_file[STDOUT_FILENO]);
4259         if (c->std_error == EXEC_OUTPUT_FILE)
4260                 fprintf(f, "%sStandardErrorFile: %s\n", prefix, c->stdio_file[STDERR_FILENO]);
4261         if (c->std_error == EXEC_OUTPUT_FILE_APPEND)
4262                 fprintf(f, "%sStandardErrorFileToAppend: %s\n", prefix, c->stdio_file[STDERR_FILENO]);
4263
4264         if (c->tty_path)
4265                 fprintf(f,
4266                         "%sTTYPath: %s\n"
4267                         "%sTTYReset: %s\n"
4268                         "%sTTYVHangup: %s\n"
4269                         "%sTTYVTDisallocate: %s\n",
4270                         prefix, c->tty_path,
4271                         prefix, yes_no(c->tty_reset),
4272                         prefix, yes_no(c->tty_vhangup),
4273                         prefix, yes_no(c->tty_vt_disallocate));
4274
4275         if (IN_SET(c->std_output,
4276                    EXEC_OUTPUT_SYSLOG,
4277                    EXEC_OUTPUT_KMSG,
4278                    EXEC_OUTPUT_JOURNAL,
4279                    EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
4280                    EXEC_OUTPUT_KMSG_AND_CONSOLE,
4281                    EXEC_OUTPUT_JOURNAL_AND_CONSOLE) ||
4282             IN_SET(c->std_error,
4283                    EXEC_OUTPUT_SYSLOG,
4284                    EXEC_OUTPUT_KMSG,
4285                    EXEC_OUTPUT_JOURNAL,
4286                    EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
4287                    EXEC_OUTPUT_KMSG_AND_CONSOLE,
4288                    EXEC_OUTPUT_JOURNAL_AND_CONSOLE)) {
4289
4290                 _cleanup_free_ char *fac_str = NULL, *lvl_str = NULL;
4291
4292                 r = log_facility_unshifted_to_string_alloc(c->syslog_priority >> 3, &fac_str);
4293                 if (r >= 0)
4294                         fprintf(f, "%sSyslogFacility: %s\n", prefix, fac_str);
4295
4296                 r = log_level_to_string_alloc(LOG_PRI(c->syslog_priority), &lvl_str);
4297                 if (r >= 0)
4298                         fprintf(f, "%sSyslogLevel: %s\n", prefix, lvl_str);
4299         }
4300
4301         if (c->log_level_max >= 0) {
4302                 _cleanup_free_ char *t = NULL;
4303
4304                 (void) log_level_to_string_alloc(c->log_level_max, &t);
4305
4306                 fprintf(f, "%sLogLevelMax: %s\n", prefix, strna(t));
4307         }
4308
4309         if (c->log_rate_limit_interval_usec > 0) {
4310                 char buf_timespan[FORMAT_TIMESPAN_MAX];
4311
4312                 fprintf(f,
4313                         "%sLogRateLimitIntervalSec: %s\n",
4314                         prefix, format_timespan(buf_timespan, sizeof(buf_timespan), c->log_rate_limit_interval_usec, USEC_PER_SEC));
4315         }
4316
4317         if (c->log_rate_limit_burst > 0)
4318                 fprintf(f, "%sLogRateLimitBurst: %u\n", prefix, c->log_rate_limit_burst);
4319
4320         if (c->n_log_extra_fields > 0) {
4321                 size_t j;
4322
4323                 for (j = 0; j < c->n_log_extra_fields; j++) {
4324                         fprintf(f, "%sLogExtraFields: ", prefix);
4325                         fwrite(c->log_extra_fields[j].iov_base,
4326                                1, c->log_extra_fields[j].iov_len,
4327                                f);
4328                         fputc('\n', f);
4329                 }
4330         }
4331
4332         if (c->secure_bits) {
4333                 _cleanup_free_ char *str = NULL;
4334
4335                 r = secure_bits_to_string_alloc(c->secure_bits, &str);
4336                 if (r >= 0)
4337                         fprintf(f, "%sSecure Bits: %s\n", prefix, str);
4338         }
4339
4340         if (c->capability_bounding_set != CAP_ALL) {
4341                 _cleanup_free_ char *str = NULL;
4342
4343                 r = capability_set_to_string_alloc(c->capability_bounding_set, &str);
4344                 if (r >= 0)
4345                         fprintf(f, "%sCapabilityBoundingSet: %s\n", prefix, str);
4346         }
4347
4348         if (c->capability_ambient_set != 0) {
4349                 _cleanup_free_ char *str = NULL;
4350
4351                 r = capability_set_to_string_alloc(c->capability_ambient_set, &str);
4352                 if (r >= 0)
4353                         fprintf(f, "%sAmbientCapabilities: %s\n", prefix, str);
4354         }
4355
4356         if (c->user)
4357                 fprintf(f, "%sUser: %s\n", prefix, c->user);
4358         if (c->group)
4359                 fprintf(f, "%sGroup: %s\n", prefix, c->group);
4360
4361         fprintf(f, "%sDynamicUser: %s\n", prefix, yes_no(c->dynamic_user));
4362
4363         if (!strv_isempty(c->supplementary_groups)) {
4364                 fprintf(f, "%sSupplementaryGroups:", prefix);
4365                 strv_fprintf(f, c->supplementary_groups);
4366                 fputs("\n", f);
4367         }
4368
4369         if (c->pam_name)
4370                 fprintf(f, "%sPAMName: %s\n", prefix, c->pam_name);
4371
4372         if (!strv_isempty(c->read_write_paths)) {
4373                 fprintf(f, "%sReadWritePaths:", prefix);
4374                 strv_fprintf(f, c->read_write_paths);
4375                 fputs("\n", f);
4376         }
4377
4378         if (!strv_isempty(c->read_only_paths)) {
4379                 fprintf(f, "%sReadOnlyPaths:", prefix);
4380                 strv_fprintf(f, c->read_only_paths);
4381                 fputs("\n", f);
4382         }
4383
4384         if (!strv_isempty(c->inaccessible_paths)) {
4385                 fprintf(f, "%sInaccessiblePaths:", prefix);
4386                 strv_fprintf(f, c->inaccessible_paths);
4387                 fputs("\n", f);
4388         }
4389
4390         if (c->n_bind_mounts > 0)
4391                 for (i = 0; i < c->n_bind_mounts; i++)
4392                         fprintf(f, "%s%s: %s%s:%s:%s\n", prefix,
4393                                 c->bind_mounts[i].read_only ? "BindReadOnlyPaths" : "BindPaths",
4394                                 c->bind_mounts[i].ignore_enoent ? "-": "",
4395                                 c->bind_mounts[i].source,
4396                                 c->bind_mounts[i].destination,
4397                                 c->bind_mounts[i].recursive ? "rbind" : "norbind");
4398
4399         if (c->n_temporary_filesystems > 0)
4400                 for (i = 0; i < c->n_temporary_filesystems; i++) {
4401                         TemporaryFileSystem *t = c->temporary_filesystems + i;
4402
4403                         fprintf(f, "%sTemporaryFileSystem: %s%s%s\n", prefix,
4404                                 t->path,
4405                                 isempty(t->options) ? "" : ":",
4406                                 strempty(t->options));
4407                 }
4408
4409         if (c->utmp_id)
4410                 fprintf(f,
4411                         "%sUtmpIdentifier: %s\n",
4412                         prefix, c->utmp_id);
4413
4414         if (c->selinux_context)
4415                 fprintf(f,
4416                         "%sSELinuxContext: %s%s\n",
4417                         prefix, c->selinux_context_ignore ? "-" : "", c->selinux_context);
4418
4419         if (c->apparmor_profile)
4420                 fprintf(f,
4421                         "%sAppArmorProfile: %s%s\n",
4422                         prefix, c->apparmor_profile_ignore ? "-" : "", c->apparmor_profile);
4423
4424         if (c->smack_process_label)
4425                 fprintf(f,
4426                         "%sSmackProcessLabel: %s%s\n",
4427                         prefix, c->smack_process_label_ignore ? "-" : "", c->smack_process_label);
4428
4429         if (c->personality != PERSONALITY_INVALID)
4430                 fprintf(f,
4431                         "%sPersonality: %s\n",
4432                         prefix, strna(personality_to_string(c->personality)));
4433
4434         fprintf(f,
4435                 "%sLockPersonality: %s\n",
4436                 prefix, yes_no(c->lock_personality));
4437
4438         if (c->syscall_filter) {
4439 #if HAVE_SECCOMP
4440                 Iterator j;
4441                 void *id, *val;
4442                 bool first = true;
4443 #endif
4444
4445                 fprintf(f,
4446                         "%sSystemCallFilter: ",
4447                         prefix);
4448
4449                 if (!c->syscall_whitelist)
4450                         fputc('~', f);
4451
4452 #if HAVE_SECCOMP
4453                 HASHMAP_FOREACH_KEY(val, id, c->syscall_filter, j) {
4454                         _cleanup_free_ char *name = NULL;
4455                         const char *errno_name = NULL;
4456                         int num = PTR_TO_INT(val);
4457
4458                         if (first)
4459                                 first = false;
4460                         else
4461                                 fputc(' ', f);
4462
4463                         name = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE, PTR_TO_INT(id) - 1);
4464                         fputs(strna(name), f);
4465
4466                         if (num >= 0) {
4467                                 errno_name = errno_to_name(num);
4468                                 if (errno_name)
4469                                         fprintf(f, ":%s", errno_name);
4470                                 else
4471                                         fprintf(f, ":%d", num);
4472                         }
4473                 }
4474 #endif
4475
4476                 fputc('\n', f);
4477         }
4478
4479         if (c->syscall_archs) {
4480 #if HAVE_SECCOMP
4481                 Iterator j;
4482                 void *id;
4483 #endif
4484
4485                 fprintf(f,
4486                         "%sSystemCallArchitectures:",
4487                         prefix);
4488
4489 #if HAVE_SECCOMP
4490                 SET_FOREACH(id, c->syscall_archs, j)
4491                         fprintf(f, " %s", strna(seccomp_arch_to_string(PTR_TO_UINT32(id) - 1)));
4492 #endif
4493                 fputc('\n', f);
4494         }
4495
4496         if (exec_context_restrict_namespaces_set(c)) {
4497                 _cleanup_free_ char *s = NULL;
4498
4499                 r = namespace_flags_to_string(c->restrict_namespaces, &s);
4500                 if (r >= 0)
4501                         fprintf(f, "%sRestrictNamespaces: %s\n",
4502                                 prefix, s);
4503         }
4504
4505         if (c->syscall_errno > 0) {
4506                 const char *errno_name;
4507
4508                 fprintf(f, "%sSystemCallErrorNumber: ", prefix);
4509
4510                 errno_name = errno_to_name(c->syscall_errno);
4511                 if (errno_name)
4512                         fprintf(f, "%s\n", errno_name);
4513                 else
4514                         fprintf(f, "%d\n", c->syscall_errno);
4515         }
4516
4517         if (c->apparmor_profile)
4518                 fprintf(f,
4519                         "%sAppArmorProfile: %s%s\n",
4520                         prefix, c->apparmor_profile_ignore ? "-" : "", c->apparmor_profile);
4521 }
4522
4523 bool exec_context_maintains_privileges(const ExecContext *c) {
4524         assert(c);
4525
4526         /* Returns true if the process forked off would run under
4527          * an unchanged UID or as root. */
4528
4529         if (!c->user)
4530                 return true;
4531
4532         if (streq(c->user, "root") || streq(c->user, "0"))
4533                 return true;
4534
4535         return false;
4536 }
4537
4538 int exec_context_get_effective_ioprio(const ExecContext *c) {
4539         int p;
4540
4541         assert(c);
4542
4543         if (c->ioprio_set)
4544                 return c->ioprio;
4545
4546         p = ioprio_get(IOPRIO_WHO_PROCESS, 0);
4547         if (p < 0)
4548                 return IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 4);
4549
4550         return p;
4551 }
4552
4553 void exec_context_free_log_extra_fields(ExecContext *c) {
4554         size_t l;
4555
4556         assert(c);
4557
4558         for (l = 0; l < c->n_log_extra_fields; l++)
4559                 free(c->log_extra_fields[l].iov_base);
4560         c->log_extra_fields = mfree(c->log_extra_fields);
4561         c->n_log_extra_fields = 0;
4562 }
4563
4564 void exec_status_start(ExecStatus *s, pid_t pid) {
4565         assert(s);
4566
4567         *s = (ExecStatus) {
4568                 .pid = pid,
4569         };
4570
4571         dual_timestamp_get(&s->start_timestamp);
4572 }
4573
4574 void exec_status_exit(ExecStatus *s, const ExecContext *context, pid_t pid, int code, int status) {
4575         assert(s);
4576
4577         if (s->pid != pid) {
4578                 *s = (ExecStatus) {
4579                         .pid = pid,
4580                 };
4581         }
4582
4583         dual_timestamp_get(&s->exit_timestamp);
4584
4585         s->code = code;
4586         s->status = status;
4587
4588         if (context) {
4589                 if (context->utmp_id)
4590                         (void) utmp_put_dead_process(context->utmp_id, pid, code, status);
4591
4592                 exec_context_tty_reset(context, NULL);
4593         }
4594 }
4595
4596 void exec_status_reset(ExecStatus *s) {
4597         assert(s);
4598
4599         *s = (ExecStatus) {};
4600 }
4601
4602 void exec_status_dump(const ExecStatus *s, FILE *f, const char *prefix) {
4603         char buf[FORMAT_TIMESTAMP_MAX];
4604
4605         assert(s);
4606         assert(f);
4607
4608         if (s->pid <= 0)
4609                 return;
4610
4611         prefix = strempty(prefix);
4612
4613         fprintf(f,
4614                 "%sPID: "PID_FMT"\n",
4615                 prefix, s->pid);
4616
4617         if (dual_timestamp_is_set(&s->start_timestamp))
4618                 fprintf(f,
4619                         "%sStart Timestamp: %s\n",
4620                         prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp.realtime));
4621
4622         if (dual_timestamp_is_set(&s->exit_timestamp))
4623                 fprintf(f,
4624                         "%sExit Timestamp: %s\n"
4625                         "%sExit Code: %s\n"
4626                         "%sExit Status: %i\n",
4627                         prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp.realtime),
4628                         prefix, sigchld_code_to_string(s->code),
4629                         prefix, s->status);
4630 }
4631
4632 static char *exec_command_line(char **argv) {
4633         size_t k;
4634         char *n, *p, **a;
4635         bool first = true;
4636
4637         assert(argv);
4638
4639         k = 1;
4640         STRV_FOREACH(a, argv)
4641                 k += strlen(*a)+3;
4642
4643         n = new(char, k);
4644         if (!n)
4645                 return NULL;
4646
4647         p = n;
4648         STRV_FOREACH(a, argv) {
4649
4650                 if (!first)
4651                         *(p++) = ' ';
4652                 else
4653                         first = false;
4654
4655                 if (strpbrk(*a, WHITESPACE)) {
4656                         *(p++) = '\'';
4657                         p = stpcpy(p, *a);
4658                         *(p++) = '\'';
4659                 } else
4660                         p = stpcpy(p, *a);
4661
4662         }
4663
4664         *p = 0;
4665
4666         /* FIXME: this doesn't really handle arguments that have
4667          * spaces and ticks in them */
4668
4669         return n;
4670 }
4671
4672 static void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
4673         _cleanup_free_ char *cmd = NULL;
4674         const char *prefix2;
4675
4676         assert(c);
4677         assert(f);
4678
4679         prefix = strempty(prefix);
4680         prefix2 = strjoina(prefix, "\t");
4681
4682         cmd = exec_command_line(c->argv);
4683         fprintf(f,
4684                 "%sCommand Line: %s\n",
4685                 prefix, cmd ? cmd : strerror(ENOMEM));
4686
4687         exec_status_dump(&c->exec_status, f, prefix2);
4688 }
4689
4690 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
4691         assert(f);
4692
4693         prefix = strempty(prefix);
4694
4695         LIST_FOREACH(command, c, c)
4696                 exec_command_dump(c, f, prefix);
4697 }
4698
4699 void exec_command_append_list(ExecCommand **l, ExecCommand *e) {
4700         ExecCommand *end;
4701
4702         assert(l);
4703         assert(e);
4704
4705         if (*l) {
4706                 /* It's kind of important, that we keep the order here */
4707                 LIST_FIND_TAIL(command, *l, end);
4708                 LIST_INSERT_AFTER(command, *l, end, e);
4709         } else
4710               *l = e;
4711 }
4712
4713 int exec_command_set(ExecCommand *c, const char *path, ...) {
4714         va_list ap;
4715         char **l, *p;
4716
4717         assert(c);
4718         assert(path);
4719
4720         va_start(ap, path);
4721         l = strv_new_ap(path, ap);
4722         va_end(ap);
4723
4724         if (!l)
4725                 return -ENOMEM;
4726
4727         p = strdup(path);
4728         if (!p) {
4729                 strv_free(l);
4730                 return -ENOMEM;
4731         }
4732
4733         free_and_replace(c->path, p);
4734
4735         return strv_free_and_replace(c->argv, l);
4736 }
4737
4738 int exec_command_append(ExecCommand *c, const char *path, ...) {
4739         _cleanup_strv_free_ char **l = NULL;
4740         va_list ap;
4741         int r;
4742
4743         assert(c);
4744         assert(path);
4745
4746         va_start(ap, path);
4747         l = strv_new_ap(path, ap);
4748         va_end(ap);
4749
4750         if (!l)
4751                 return -ENOMEM;
4752
4753         r = strv_extend_strv(&c->argv, l, false);
4754         if (r < 0)
4755                 return r;
4756
4757         return 0;
4758 }
4759
4760 static void *remove_tmpdir_thread(void *p) {
4761         _cleanup_free_ char *path = p;
4762
4763         (void) rm_rf(path, REMOVE_ROOT|REMOVE_PHYSICAL);
4764         return NULL;
4765 }
4766
4767 static ExecRuntime* exec_runtime_free(ExecRuntime *rt, bool destroy) {
4768         int r;
4769
4770         if (!rt)
4771                 return NULL;
4772
4773         if (rt->manager)
4774                 (void) hashmap_remove(rt->manager->exec_runtime_by_id, rt->id);
4775
4776         /* When destroy is true, then rm_rf tmp_dir and var_tmp_dir. */
4777         if (destroy && rt->tmp_dir) {
4778                 log_debug("Spawning thread to nuke %s", rt->tmp_dir);
4779
4780                 r = asynchronous_job(remove_tmpdir_thread, rt->tmp_dir);
4781                 if (r < 0) {
4782                         log_warning_errno(r, "Failed to nuke %s: %m", rt->tmp_dir);
4783                         free(rt->tmp_dir);
4784                 }
4785
4786                 rt->tmp_dir = NULL;
4787         }
4788
4789         if (destroy && rt->var_tmp_dir) {
4790                 log_debug("Spawning thread to nuke %s", rt->var_tmp_dir);
4791
4792                 r = asynchronous_job(remove_tmpdir_thread, rt->var_tmp_dir);
4793                 if (r < 0) {
4794                         log_warning_errno(r, "Failed to nuke %s: %m", rt->var_tmp_dir);
4795                         free(rt->var_tmp_dir);
4796                 }
4797
4798                 rt->var_tmp_dir = NULL;
4799         }
4800
4801         rt->id = mfree(rt->id);
4802         rt->tmp_dir = mfree(rt->tmp_dir);
4803         rt->var_tmp_dir = mfree(rt->var_tmp_dir);
4804         safe_close_pair(rt->netns_storage_socket);
4805         return mfree(rt);
4806 }
4807
4808 static void exec_runtime_freep(ExecRuntime **rt) {
4809         if (*rt)
4810                 (void) exec_runtime_free(*rt, false);
4811 }
4812
4813 static int exec_runtime_allocate(ExecRuntime **rt) {
4814         assert(rt);
4815
4816         *rt = new0(ExecRuntime, 1);
4817         if (!*rt)
4818                 return -ENOMEM;
4819
4820         (*rt)->netns_storage_socket[0] = (*rt)->netns_storage_socket[1] = -1;
4821         return 0;
4822 }
4823
4824 static int exec_runtime_add(
4825                 Manager *m,
4826                 const char *id,
4827                 const char *tmp_dir,
4828                 const char *var_tmp_dir,
4829                 const int netns_storage_socket[2],
4830                 ExecRuntime **ret) {
4831
4832         _cleanup_(exec_runtime_freep) ExecRuntime *rt = NULL;
4833         int r;
4834
4835         assert(m);
4836         assert(id);
4837
4838         r = hashmap_ensure_allocated(&m->exec_runtime_by_id, &string_hash_ops);
4839         if (r < 0)
4840                 return r;
4841
4842         r = exec_runtime_allocate(&rt);
4843         if (r < 0)
4844                 return r;
4845
4846         rt->id = strdup(id);
4847         if (!rt->id)
4848                 return -ENOMEM;
4849
4850         if (tmp_dir) {
4851                 rt->tmp_dir = strdup(tmp_dir);
4852                 if (!rt->tmp_dir)
4853                         return -ENOMEM;
4854
4855                 /* When tmp_dir is set, then we require var_tmp_dir is also set. */
4856                 assert(var_tmp_dir);
4857                 rt->var_tmp_dir = strdup(var_tmp_dir);
4858                 if (!rt->var_tmp_dir)
4859                         return -ENOMEM;
4860         }
4861
4862         if (netns_storage_socket) {
4863                 rt->netns_storage_socket[0] = netns_storage_socket[0];
4864                 rt->netns_storage_socket[1] = netns_storage_socket[1];
4865         }
4866
4867         r = hashmap_put(m->exec_runtime_by_id, rt->id, rt);
4868         if (r < 0)
4869                 return r;
4870
4871         rt->manager = m;
4872
4873         if (ret)
4874                 *ret = rt;
4875
4876         /* do not remove created ExecRuntime object when the operation succeeds. */
4877         rt = NULL;
4878         return 0;
4879 }
4880
4881 static int exec_runtime_make(Manager *m, const ExecContext *c, const char *id, ExecRuntime **ret) {
4882         _cleanup_free_ char *tmp_dir = NULL, *var_tmp_dir = NULL;
4883         _cleanup_close_pair_ int netns_storage_socket[2] = {-1, -1};
4884         int r;
4885
4886         assert(m);
4887         assert(c);
4888         assert(id);
4889
4890         /* It is not necessary to create ExecRuntime object. */
4891         if (!c->private_network && !c->private_tmp)
4892                 return 0;
4893
4894         if (c->private_tmp) {
4895                 r = setup_tmp_dirs(id, &tmp_dir, &var_tmp_dir);
4896                 if (r < 0)
4897                         return r;
4898         }
4899
4900         if (c->private_network) {
4901                 if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, netns_storage_socket) < 0)
4902                         return -errno;
4903         }
4904
4905         r = exec_runtime_add(m, id, tmp_dir, var_tmp_dir, netns_storage_socket, ret);
4906         if (r < 0)
4907                 return r;
4908
4909         /* Avoid cleanup */
4910         netns_storage_socket[0] = -1;
4911         netns_storage_socket[1] = -1;
4912         return 1;
4913 }
4914
4915 int exec_runtime_acquire(Manager *m, const ExecContext *c, const char *id, bool create, ExecRuntime **ret) {
4916         ExecRuntime *rt;
4917         int r;
4918
4919         assert(m);
4920         assert(id);
4921         assert(ret);
4922
4923         rt = hashmap_get(m->exec_runtime_by_id, id);
4924         if (rt)
4925                 /* We already have a ExecRuntime object, let's increase the ref count and reuse it */
4926                 goto ref;
4927
4928         if (!create)
4929                 return 0;
4930
4931         /* If not found, then create a new object. */
4932         r = exec_runtime_make(m, c, id, &rt);
4933         if (r <= 0)
4934                 /* When r == 0, it is not necessary to create ExecRuntime object. */
4935                 return r;
4936
4937 ref:
4938         /* increment reference counter. */
4939         rt->n_ref++;
4940         *ret = rt;
4941         return 1;
4942 }
4943
4944 ExecRuntime *exec_runtime_unref(ExecRuntime *rt, bool destroy) {
4945         if (!rt)
4946                 return NULL;
4947
4948         assert(rt->n_ref > 0);
4949
4950         rt->n_ref--;
4951         if (rt->n_ref > 0)
4952                 return NULL;
4953
4954         return exec_runtime_free(rt, destroy);
4955 }
4956
4957 int exec_runtime_serialize(const Manager *m, FILE *f, FDSet *fds) {
4958         ExecRuntime *rt;
4959         Iterator i;
4960
4961         assert(m);
4962         assert(f);
4963         assert(fds);
4964
4965         HASHMAP_FOREACH(rt, m->exec_runtime_by_id, i) {
4966                 fprintf(f, "exec-runtime=%s", rt->id);
4967
4968                 if (rt->tmp_dir)
4969                         fprintf(f, " tmp-dir=%s", rt->tmp_dir);
4970
4971                 if (rt->var_tmp_dir)
4972                         fprintf(f, " var-tmp-dir=%s", rt->var_tmp_dir);
4973
4974                 if (rt->netns_storage_socket[0] >= 0) {
4975                         int copy;
4976
4977                         copy = fdset_put_dup(fds, rt->netns_storage_socket[0]);
4978                         if (copy < 0)
4979                                 return copy;
4980
4981                         fprintf(f, " netns-socket-0=%i", copy);
4982                 }
4983
4984                 if (rt->netns_storage_socket[1] >= 0) {
4985                         int copy;
4986
4987                         copy = fdset_put_dup(fds, rt->netns_storage_socket[1]);
4988                         if (copy < 0)
4989                                 return copy;
4990
4991                         fprintf(f, " netns-socket-1=%i", copy);
4992                 }
4993
4994                 fputc('\n', f);
4995         }
4996
4997         return 0;
4998 }
4999
5000 int exec_runtime_deserialize_compat(Unit *u, const char *key, const char *value, FDSet *fds) {
5001         _cleanup_(exec_runtime_freep) ExecRuntime *rt_create = NULL;
5002         ExecRuntime *rt;
5003         int r;
5004
5005         /* This is for the migration from old (v237 or earlier) deserialization text.
5006          * Due to the bug #7790, this may not work with the units that use JoinsNamespaceOf=.
5007          * Even if the ExecRuntime object originally created by the other unit, we cannot judge
5008          * so or not from the serialized text, then we always creates a new object owned by this. */
5009
5010         assert(u);
5011         assert(key);
5012         assert(value);
5013
5014         /* Manager manages ExecRuntime objects by the unit id.
5015          * So, we omit the serialized text when the unit does not have id (yet?)... */
5016         if (isempty(u->id)) {
5017                 log_unit_debug(u, "Invocation ID not found. Dropping runtime parameter.");
5018                 return 0;
5019         }
5020
5021         r = hashmap_ensure_allocated(&u->manager->exec_runtime_by_id, &string_hash_ops);
5022         if (r < 0) {
5023                 log_unit_debug_errno(u, r, "Failed to allocate storage for runtime parameter: %m");
5024                 return 0;
5025         }
5026
5027         rt = hashmap_get(u->manager->exec_runtime_by_id, u->id);
5028         if (!rt) {
5029                 r = exec_runtime_allocate(&rt_create);
5030                 if (r < 0)
5031                         return log_oom();
5032
5033                 rt_create->id = strdup(u->id);
5034                 if (!rt_create->id)
5035                         return log_oom();
5036
5037                 rt = rt_create;
5038         }
5039
5040         if (streq(key, "tmp-dir")) {
5041                 char *copy;
5042
5043                 copy = strdup(value);
5044                 if (!copy)
5045                         return log_oom();
5046
5047                 free_and_replace(rt->tmp_dir, copy);
5048
5049         } else if (streq(key, "var-tmp-dir")) {
5050                 char *copy;
5051
5052                 copy = strdup(value);
5053                 if (!copy)
5054                         return log_oom();
5055
5056                 free_and_replace(rt->var_tmp_dir, copy);
5057
5058         } else if (streq(key, "netns-socket-0")) {
5059                 int fd;
5060
5061                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd)) {
5062                         log_unit_debug(u, "Failed to parse netns socket value: %s", value);
5063                         return 0;
5064                 }
5065
5066                 safe_close(rt->netns_storage_socket[0]);
5067                 rt->netns_storage_socket[0] = fdset_remove(fds, fd);
5068
5069         } else if (streq(key, "netns-socket-1")) {
5070                 int fd;
5071
5072                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd)) {
5073                         log_unit_debug(u, "Failed to parse netns socket value: %s", value);
5074                         return 0;
5075                 }
5076
5077                 safe_close(rt->netns_storage_socket[1]);
5078                 rt->netns_storage_socket[1] = fdset_remove(fds, fd);
5079         } else
5080                 return 0;
5081
5082         /* If the object is newly created, then put it to the hashmap which manages ExecRuntime objects. */
5083         if (rt_create) {
5084                 r = hashmap_put(u->manager->exec_runtime_by_id, rt_create->id, rt_create);
5085                 if (r < 0) {
5086                         log_unit_debug_errno(u, r, "Failed to put runtime parameter to manager's storage: %m");
5087                         return 0;
5088                 }
5089
5090                 rt_create->manager = u->manager;
5091
5092                 /* Avoid cleanup */
5093                 rt_create = NULL;
5094         }
5095
5096         return 1;
5097 }
5098
5099 void exec_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds) {
5100         char *id = NULL, *tmp_dir = NULL, *var_tmp_dir = NULL;
5101         int r, fd0 = -1, fd1 = -1;
5102         const char *p, *v = value;
5103         size_t n;
5104
5105         assert(m);
5106         assert(value);
5107         assert(fds);
5108
5109         n = strcspn(v, " ");
5110         id = strndupa(v, n);
5111         if (v[n] != ' ')
5112                 goto finalize;
5113         p = v + n + 1;
5114
5115         v = startswith(p, "tmp-dir=");
5116         if (v) {
5117                 n = strcspn(v, " ");
5118                 tmp_dir = strndupa(v, n);
5119                 if (v[n] != ' ')
5120                         goto finalize;
5121                 p = v + n + 1;
5122         }
5123
5124         v = startswith(p, "var-tmp-dir=");
5125         if (v) {
5126                 n = strcspn(v, " ");
5127                 var_tmp_dir = strndupa(v, n);
5128                 if (v[n] != ' ')
5129                         goto finalize;
5130                 p = v + n + 1;
5131         }
5132
5133         v = startswith(p, "netns-socket-0=");
5134         if (v) {
5135                 char *buf;
5136
5137                 n = strcspn(v, " ");
5138                 buf = strndupa(v, n);
5139                 if (safe_atoi(buf, &fd0) < 0 || !fdset_contains(fds, fd0)) {
5140                         log_debug("Unable to process exec-runtime netns fd specification.");
5141                         return;
5142                 }
5143                 fd0 = fdset_remove(fds, fd0);
5144                 if (v[n] != ' ')
5145                         goto finalize;
5146                 p = v + n + 1;
5147         }
5148
5149         v = startswith(p, "netns-socket-1=");
5150         if (v) {
5151                 char *buf;
5152
5153                 n = strcspn(v, " ");
5154                 buf = strndupa(v, n);
5155                 if (safe_atoi(buf, &fd1) < 0 || !fdset_contains(fds, fd1)) {
5156                         log_debug("Unable to process exec-runtime netns fd specification.");
5157                         return;
5158                 }
5159                 fd1 = fdset_remove(fds, fd1);
5160         }
5161
5162 finalize:
5163
5164         r = exec_runtime_add(m, id, tmp_dir, var_tmp_dir, (int[]) { fd0, fd1 }, NULL);
5165         if (r < 0)
5166                 log_debug_errno(r, "Failed to add exec-runtime: %m");
5167 }
5168
5169 void exec_runtime_vacuum(Manager *m) {
5170         ExecRuntime *rt;
5171         Iterator i;
5172
5173         assert(m);
5174
5175         /* Free unreferenced ExecRuntime objects. This is used after manager deserialization process. */
5176
5177         HASHMAP_FOREACH(rt, m->exec_runtime_by_id, i) {
5178                 if (rt->n_ref > 0)
5179                         continue;
5180
5181                 (void) exec_runtime_free(rt, false);
5182         }
5183 }
5184
5185 void exec_params_clear(ExecParameters *p) {
5186         if (!p)
5187                 return;
5188
5189         strv_free(p->environment);
5190 }
5191
5192 static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
5193         [EXEC_INPUT_NULL] = "null",
5194         [EXEC_INPUT_TTY] = "tty",
5195         [EXEC_INPUT_TTY_FORCE] = "tty-force",
5196         [EXEC_INPUT_TTY_FAIL] = "tty-fail",
5197         [EXEC_INPUT_SOCKET] = "socket",
5198         [EXEC_INPUT_NAMED_FD] = "fd",
5199         [EXEC_INPUT_DATA] = "data",
5200         [EXEC_INPUT_FILE] = "file",
5201 };
5202
5203 DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);
5204
5205 static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
5206         [EXEC_OUTPUT_INHERIT] = "inherit",
5207         [EXEC_OUTPUT_NULL] = "null",
5208         [EXEC_OUTPUT_TTY] = "tty",
5209         [EXEC_OUTPUT_SYSLOG] = "syslog",
5210         [EXEC_OUTPUT_SYSLOG_AND_CONSOLE] = "syslog+console",
5211         [EXEC_OUTPUT_KMSG] = "kmsg",
5212         [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
5213         [EXEC_OUTPUT_JOURNAL] = "journal",
5214         [EXEC_OUTPUT_JOURNAL_AND_CONSOLE] = "journal+console",
5215         [EXEC_OUTPUT_SOCKET] = "socket",
5216         [EXEC_OUTPUT_NAMED_FD] = "fd",
5217         [EXEC_OUTPUT_FILE] = "file",
5218         [EXEC_OUTPUT_FILE_APPEND] = "append",
5219 };
5220
5221 DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);
5222
5223 static const char* const exec_utmp_mode_table[_EXEC_UTMP_MODE_MAX] = {
5224         [EXEC_UTMP_INIT] = "init",
5225         [EXEC_UTMP_LOGIN] = "login",
5226         [EXEC_UTMP_USER] = "user",
5227 };
5228
5229 DEFINE_STRING_TABLE_LOOKUP(exec_utmp_mode, ExecUtmpMode);
5230
5231 static const char* const exec_preserve_mode_table[_EXEC_PRESERVE_MODE_MAX] = {
5232         [EXEC_PRESERVE_NO] = "no",
5233         [EXEC_PRESERVE_YES] = "yes",
5234         [EXEC_PRESERVE_RESTART] = "restart",
5235 };
5236
5237 DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(exec_preserve_mode, ExecPreserveMode, EXEC_PRESERVE_YES);
5238
5239 static const char* const exec_directory_type_table[_EXEC_DIRECTORY_TYPE_MAX] = {
5240         [EXEC_DIRECTORY_RUNTIME] = "RuntimeDirectory",
5241         [EXEC_DIRECTORY_STATE] = "StateDirectory",
5242         [EXEC_DIRECTORY_CACHE] = "CacheDirectory",
5243         [EXEC_DIRECTORY_LOGS] = "LogsDirectory",
5244         [EXEC_DIRECTORY_CONFIGURATION] = "ConfigurationDirectory",
5245 };
5246
5247 DEFINE_STRING_TABLE_LOOKUP(exec_directory_type, ExecDirectoryType);
5248
5249 static const char* const exec_directory_env_name_table[_EXEC_DIRECTORY_TYPE_MAX] = {
5250         [EXEC_DIRECTORY_RUNTIME] = "RUNTIME_DIRECTORY",
5251         [EXEC_DIRECTORY_STATE] = "STATE_DIRECTORY",
5252         [EXEC_DIRECTORY_CACHE] = "CACHE_DIRECTORY",
5253         [EXEC_DIRECTORY_LOGS] = "LOGS_DIRECTORY",
5254         [EXEC_DIRECTORY_CONFIGURATION] = "CONFIGURATION_DIRECTORY",
5255 };
5256
5257 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(exec_directory_env_name, ExecDirectoryType);
5258
5259 static const char* const exec_keyring_mode_table[_EXEC_KEYRING_MODE_MAX] = {
5260         [EXEC_KEYRING_INHERIT] = "inherit",
5261         [EXEC_KEYRING_PRIVATE] = "private",
5262         [EXEC_KEYRING_SHARED] = "shared",
5263 };
5264
5265 DEFINE_STRING_TABLE_LOOKUP(exec_keyring_mode, ExecKeyringMode);