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 (!(p->flags & EXEC_NEW_KEYRING))
2534                 return 0;
2535
2536         if (context->keyring_mode == EXEC_KEYRING_INHERIT)
2537                 return 0;
2538
2539         /* Acquiring a reference to the user keyring is nasty. We briefly change identity in order to get things set up
2540          * properly by the kernel. If we don't do that then we can't create it atomically, and that sucks for parallel
2541          * execution. This mimics what pam_keyinit does, too. Setting up session keyring, to be owned by the right user
2542          * & group is just as nasty as acquiring a reference to the user keyring. */
2543
2544         saved_uid = getuid();
2545         saved_gid = getgid();
2546
2547         if (gid_is_valid(gid) && gid != saved_gid) {
2548                 if (setregid(gid, -1) < 0)
2549                         return log_unit_error_errno(u, errno, "Failed to change GID for user keyring: %m");
2550         }
2551
2552         if (uid_is_valid(uid) && uid != saved_uid) {
2553                 if (setreuid(uid, -1) < 0) {
2554                         r = log_unit_error_errno(u, errno, "Failed to change UID for user keyring: %m");
2555                         goto out;
2556                 }
2557         }
2558
2559         keyring = keyctl(KEYCTL_JOIN_SESSION_KEYRING, 0, 0, 0, 0);
2560         if (keyring == -1) {
2561                 if (errno == ENOSYS)
2562                         log_unit_debug_errno(u, errno, "Kernel keyring not supported, ignoring.");
2563                 else if (IN_SET(errno, EACCES, EPERM))
2564                         log_unit_debug_errno(u, errno, "Kernel keyring access prohibited, ignoring.");
2565                 else if (errno == EDQUOT)
2566                         log_unit_debug_errno(u, errno, "Out of kernel keyrings to allocate, ignoring.");
2567                 else
2568                         r = log_unit_error_errno(u, errno, "Setting up kernel keyring failed: %m");
2569
2570                 goto out;
2571         }
2572
2573         /* When requested link the user keyring into the session keyring. */
2574         if (context->keyring_mode == EXEC_KEYRING_SHARED) {
2575
2576                 if (keyctl(KEYCTL_LINK,
2577                            KEY_SPEC_USER_KEYRING,
2578                            KEY_SPEC_SESSION_KEYRING, 0, 0) < 0) {
2579                         r = log_unit_error_errno(u, errno, "Failed to link user keyring into session keyring: %m");
2580                         goto out;
2581                 }
2582         }
2583
2584         /* Restore uid/gid back */
2585         if (uid_is_valid(uid) && uid != saved_uid) {
2586                 if (setreuid(saved_uid, -1) < 0) {
2587                         r = log_unit_error_errno(u, errno, "Failed to change UID back for user keyring: %m");
2588                         goto out;
2589                 }
2590         }
2591
2592         if (gid_is_valid(gid) && gid != saved_gid) {
2593                 if (setregid(saved_gid, -1) < 0)
2594                         return log_unit_error_errno(u, errno, "Failed to change GID back for user keyring: %m");
2595         }
2596
2597         /* Populate they keyring with the invocation ID by default, as original saved_uid. */
2598         if (!sd_id128_is_null(u->invocation_id)) {
2599                 key_serial_t key;
2600
2601                 key = add_key("user", "invocation_id", &u->invocation_id, sizeof(u->invocation_id), KEY_SPEC_SESSION_KEYRING);
2602                 if (key == -1)
2603                         log_unit_debug_errno(u, errno, "Failed to add invocation ID to keyring, ignoring: %m");
2604                 else {
2605                         if (keyctl(KEYCTL_SETPERM, key,
2606                                    KEY_POS_VIEW|KEY_POS_READ|KEY_POS_SEARCH|
2607                                    KEY_USR_VIEW|KEY_USR_READ|KEY_USR_SEARCH, 0, 0) < 0)
2608                                 r = log_unit_error_errno(u, errno, "Failed to restrict invocation ID permission: %m");
2609                 }
2610         }
2611
2612 out:
2613         /* Revert back uid & gid for the the last time, and exit */
2614         /* no extra logging, as only the first already reported error matters */
2615         if (getuid() != saved_uid)
2616                 (void) setreuid(saved_uid, -1);
2617
2618         if (getgid() != saved_gid)
2619                 (void) setregid(saved_gid, -1);
2620
2621         return r;
2622 }
2623
2624 static void append_socket_pair(int *array, size_t *n, const int pair[2]) {
2625         assert(array);
2626         assert(n);
2627
2628         if (!pair)
2629                 return;
2630
2631         if (pair[0] >= 0)
2632                 array[(*n)++] = pair[0];
2633         if (pair[1] >= 0)
2634                 array[(*n)++] = pair[1];
2635 }
2636
2637 static int close_remaining_fds(
2638                 const ExecParameters *params,
2639                 const ExecRuntime *runtime,
2640                 const DynamicCreds *dcreds,
2641                 int user_lookup_fd,
2642                 int socket_fd,
2643                 int exec_fd,
2644                 int *fds, size_t n_fds) {
2645
2646         size_t n_dont_close = 0;
2647         int dont_close[n_fds + 12];
2648
2649         assert(params);
2650
2651         if (params->stdin_fd >= 0)
2652                 dont_close[n_dont_close++] = params->stdin_fd;
2653         if (params->stdout_fd >= 0)
2654                 dont_close[n_dont_close++] = params->stdout_fd;
2655         if (params->stderr_fd >= 0)
2656                 dont_close[n_dont_close++] = params->stderr_fd;
2657
2658         if (socket_fd >= 0)
2659                 dont_close[n_dont_close++] = socket_fd;
2660         if (exec_fd >= 0)
2661                 dont_close[n_dont_close++] = exec_fd;
2662         if (n_fds > 0) {
2663                 memcpy(dont_close + n_dont_close, fds, sizeof(int) * n_fds);
2664                 n_dont_close += n_fds;
2665         }
2666
2667         if (runtime)
2668                 append_socket_pair(dont_close, &n_dont_close, runtime->netns_storage_socket);
2669
2670         if (dcreds) {
2671                 if (dcreds->user)
2672                         append_socket_pair(dont_close, &n_dont_close, dcreds->user->storage_socket);
2673                 if (dcreds->group)
2674                         append_socket_pair(dont_close, &n_dont_close, dcreds->group->storage_socket);
2675         }
2676
2677         if (user_lookup_fd >= 0)
2678                 dont_close[n_dont_close++] = user_lookup_fd;
2679
2680         return close_all_fds(dont_close, n_dont_close);
2681 }
2682
2683 static int send_user_lookup(
2684                 Unit *unit,
2685                 int user_lookup_fd,
2686                 uid_t uid,
2687                 gid_t gid) {
2688
2689         assert(unit);
2690
2691         /* Send the resolved UID/GID to PID 1 after we learnt it. We send a single datagram, containing the UID/GID
2692          * data as well as the unit name. Note that we suppress sending this if no user/group to resolve was
2693          * specified. */
2694
2695         if (user_lookup_fd < 0)
2696                 return 0;
2697
2698         if (!uid_is_valid(uid) && !gid_is_valid(gid))
2699                 return 0;
2700
2701         if (writev(user_lookup_fd,
2702                (struct iovec[]) {
2703                            IOVEC_INIT(&uid, sizeof(uid)),
2704                            IOVEC_INIT(&gid, sizeof(gid)),
2705                            IOVEC_INIT_STRING(unit->id) }, 3) < 0)
2706                 return -errno;
2707
2708         return 0;
2709 }
2710
2711 static int acquire_home(const ExecContext *c, uid_t uid, const char** home, char **buf) {
2712         int r;
2713
2714         assert(c);
2715         assert(home);
2716         assert(buf);
2717
2718         /* If WorkingDirectory=~ is set, try to acquire a usable home directory. */
2719
2720         if (*home)
2721                 return 0;
2722
2723         if (!c->working_directory_home)
2724                 return 0;
2725
2726         if (uid == 0) {
2727                 /* Hardcode /root as home directory for UID 0 */
2728                 *home = "/root";
2729                 return 1;
2730         }
2731
2732         r = get_home_dir(buf);
2733         if (r < 0)
2734                 return r;
2735
2736         *home = *buf;
2737         return 1;
2738 }
2739
2740 static int compile_suggested_paths(const ExecContext *c, const ExecParameters *p, char ***ret) {
2741         _cleanup_strv_free_ char ** list = NULL;
2742         ExecDirectoryType t;
2743         int r;
2744
2745         assert(c);
2746         assert(p);
2747         assert(ret);
2748
2749         assert(c->dynamic_user);
2750
2751         /* Compile a list of paths that it might make sense to read the owning UID from to use as initial candidate for
2752          * dynamic UID allocation, in order to save us from doing costly recursive chown()s of the special
2753          * directories. */
2754
2755         for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
2756                 char **i;
2757
2758                 if (t == EXEC_DIRECTORY_CONFIGURATION)
2759                         continue;
2760
2761                 if (!p->prefix[t])
2762                         continue;
2763
2764                 STRV_FOREACH(i, c->directories[t].paths) {
2765                         char *e;
2766
2767                         if (t == EXEC_DIRECTORY_RUNTIME)
2768                                 e = strjoin(p->prefix[t], "/", *i);
2769                         else
2770                                 e = strjoin(p->prefix[t], "/private/", *i);
2771                         if (!e)
2772                                 return -ENOMEM;
2773
2774                         r = strv_consume(&list, e);
2775                         if (r < 0)
2776                                 return r;
2777                 }
2778         }
2779
2780         *ret = TAKE_PTR(list);
2781
2782         return 0;
2783 }
2784
2785 static char *exec_command_line(char **argv);
2786
2787 static int exec_parameters_get_cgroup_path(const ExecParameters *params, char **ret) {
2788         bool using_subcgroup;
2789         char *p;
2790
2791         assert(params);
2792         assert(ret);
2793
2794         if (!params->cgroup_path)
2795                 return -EINVAL;
2796
2797         /* If we are called for a unit where cgroup delegation is on, and the payload created its own populated
2798          * subcgroup (which we expect it to do, after all it asked for delegation), then we cannot place the control
2799          * processes started after the main unit's process in the unit's main cgroup because it is now an inner one,
2800          * and inner cgroups may not contain processes. Hence, if delegation is on, and this is a control process,
2801          * let's use ".control" as subcgroup instead. Note that we do so only for ExecStartPost=, ExecReload=,
2802          * ExecStop=, ExecStopPost=, i.e. for the commands where the main process is already forked. For ExecStartPre=
2803          * this is not necessary, the cgroup is still empty. We distinguish these cases with the EXEC_CONTROL_CGROUP
2804          * flag, which is only passed for the former statements, not for the latter. */
2805
2806         using_subcgroup = FLAGS_SET(params->flags, EXEC_CONTROL_CGROUP|EXEC_CGROUP_DELEGATE|EXEC_IS_CONTROL);
2807         if (using_subcgroup)
2808                 p = strjoin(params->cgroup_path, "/.control");
2809         else
2810                 p = strdup(params->cgroup_path);
2811         if (!p)
2812                 return -ENOMEM;
2813
2814         *ret = p;
2815         return using_subcgroup;
2816 }
2817
2818 static int exec_child(
2819                 Unit *unit,
2820                 const ExecCommand *command,
2821                 const ExecContext *context,
2822                 const ExecParameters *params,
2823                 ExecRuntime *runtime,
2824                 DynamicCreds *dcreds,
2825                 int socket_fd,
2826                 int named_iofds[3],
2827                 int *fds,
2828                 size_t n_socket_fds,
2829                 size_t n_storage_fds,
2830                 char **files_env,
2831                 int user_lookup_fd,
2832                 int *exit_status) {
2833
2834         _cleanup_strv_free_ char **our_env = NULL, **pass_env = NULL, **accum_env = NULL, **final_argv = NULL;
2835         int *fds_with_exec_fd, n_fds_with_exec_fd, r, ngids = 0, exec_fd = -1;
2836         _cleanup_free_ gid_t *supplementary_gids = NULL;
2837         const char *username = NULL, *groupname = NULL;
2838         _cleanup_free_ char *home_buffer = NULL;
2839         const char *home = NULL, *shell = NULL;
2840         dev_t journal_stream_dev = 0;
2841         ino_t journal_stream_ino = 0;
2842         bool needs_sandboxing,          /* Do we need to set up full sandboxing? (i.e. all namespacing, all MAC stuff, caps, yadda yadda */
2843                 needs_setuid,           /* Do we need to do the actual setresuid()/setresgid() calls? */
2844                 needs_mount_namespace,  /* Do we need to set up a mount namespace for this kernel? */
2845                 needs_ambient_hack;     /* Do we need to apply the ambient capabilities hack? */
2846 #if HAVE_SELINUX
2847         _cleanup_free_ char *mac_selinux_context_net = NULL;
2848         bool use_selinux = false;
2849 #endif
2850 #if ENABLE_SMACK
2851         bool use_smack = false;
2852 #endif
2853 #if HAVE_APPARMOR
2854         bool use_apparmor = false;
2855 #endif
2856         uid_t uid = UID_INVALID;
2857         gid_t gid = GID_INVALID;
2858         size_t n_fds;
2859         ExecDirectoryType dt;
2860         int secure_bits;
2861
2862         assert(unit);
2863         assert(command);
2864         assert(context);
2865         assert(params);
2866         assert(exit_status);
2867
2868         rename_process_from_path(command->path);
2869
2870         /* We reset exactly these signals, since they are the
2871          * only ones we set to SIG_IGN in the main daemon. All
2872          * others we leave untouched because we set them to
2873          * SIG_DFL or a valid handler initially, both of which
2874          * will be demoted to SIG_DFL. */
2875         (void) default_signals(SIGNALS_CRASH_HANDLER,
2876                                SIGNALS_IGNORE, -1);
2877
2878         if (context->ignore_sigpipe)
2879                 (void) ignore_signals(SIGPIPE, -1);
2880
2881         r = reset_signal_mask();
2882         if (r < 0) {
2883                 *exit_status = EXIT_SIGNAL_MASK;
2884                 return log_unit_error_errno(unit, r, "Failed to set process signal mask: %m");
2885         }
2886
2887         if (params->idle_pipe)
2888                 do_idle_pipe_dance(params->idle_pipe);
2889
2890         /* Close fds we don't need very early to make sure we don't block init reexecution because it cannot bind its
2891          * sockets. Among the fds we close are the logging fds, and we want to keep them closed, so that we don't have
2892          * any fds open we don't really want open during the transition. In order to make logging work, we switch the
2893          * log subsystem into open_when_needed mode, so that it reopens the logs on every single log call. */
2894
2895         log_forget_fds();
2896         log_set_open_when_needed(true);
2897
2898         /* In case anything used libc syslog(), close this here, too */
2899         closelog();
2900
2901         n_fds = n_socket_fds + n_storage_fds;
2902         r = close_remaining_fds(params, runtime, dcreds, user_lookup_fd, socket_fd, params->exec_fd, fds, n_fds);
2903         if (r < 0) {
2904                 *exit_status = EXIT_FDS;
2905                 return log_unit_error_errno(unit, r, "Failed to close unwanted file descriptors: %m");
2906         }
2907
2908         if (!context->same_pgrp)
2909                 if (setsid() < 0) {
2910                         *exit_status = EXIT_SETSID;
2911                         return log_unit_error_errno(unit, errno, "Failed to create new process session: %m");
2912                 }
2913
2914         exec_context_tty_reset(context, params);
2915
2916         if (unit_shall_confirm_spawn(unit)) {
2917                 const char *vc = params->confirm_spawn;
2918                 _cleanup_free_ char *cmdline = NULL;
2919
2920                 cmdline = exec_command_line(command->argv);
2921                 if (!cmdline) {
2922                         *exit_status = EXIT_MEMORY;
2923                         return log_oom();
2924                 }
2925
2926                 r = ask_for_confirmation(vc, unit, cmdline);
2927                 if (r != CONFIRM_EXECUTE) {
2928                         if (r == CONFIRM_PRETEND_SUCCESS) {
2929                                 *exit_status = EXIT_SUCCESS;
2930                                 return 0;
2931                         }
2932                         *exit_status = EXIT_CONFIRM;
2933                         log_unit_error(unit, "Execution cancelled by the user");
2934                         return -ECANCELED;
2935                 }
2936         }
2937
2938         /* We are about to invoke NSS and PAM modules. Let's tell them what we are doing here, maybe they care. This is
2939          * used by nss-resolve to disable itself when we are about to start systemd-resolved, to avoid deadlocks. Note
2940          * that these env vars do not survive the execve(), which means they really only apply to the PAM and NSS
2941          * invocations themselves. Also note that while we'll only invoke NSS modules involved in user management they
2942          * might internally call into other NSS modules that are involved in hostname resolution, we never know. */
2943         if (setenv("SYSTEMD_ACTIVATION_UNIT", unit->id, true) != 0 ||
2944             setenv("SYSTEMD_ACTIVATION_SCOPE", MANAGER_IS_SYSTEM(unit->manager) ? "system" : "user", true) != 0) {
2945                 *exit_status = EXIT_MEMORY;
2946                 return log_unit_error_errno(unit, errno, "Failed to update environment: %m");
2947         }
2948
2949         if (context->dynamic_user && dcreds) {
2950                 _cleanup_strv_free_ char **suggested_paths = NULL;
2951
2952                 /* On top of that, make sure we bypass our own NSS module nss-systemd comprehensively for any NSS
2953                  * checks, if DynamicUser=1 is used, as we shouldn't create a feedback loop with ourselves here.*/
2954                 if (putenv((char*) "SYSTEMD_NSS_DYNAMIC_BYPASS=1") != 0) {
2955                         *exit_status = EXIT_USER;
2956                         return log_unit_error_errno(unit, errno, "Failed to update environment: %m");
2957                 }
2958
2959                 r = compile_suggested_paths(context, params, &suggested_paths);
2960                 if (r < 0) {
2961                         *exit_status = EXIT_MEMORY;
2962                         return log_oom();
2963                 }
2964
2965                 r = dynamic_creds_realize(dcreds, suggested_paths, &uid, &gid);
2966                 if (r < 0) {
2967                         *exit_status = EXIT_USER;
2968                         if (r == -EILSEQ) {
2969                                 log_unit_error(unit, "Failed to update dynamic user credentials: User or group with specified name already exists.");
2970                                 return -EOPNOTSUPP;
2971                         }
2972                         return log_unit_error_errno(unit, r, "Failed to update dynamic user credentials: %m");
2973                 }
2974
2975                 if (!uid_is_valid(uid)) {
2976                         *exit_status = EXIT_USER;
2977                         log_unit_error(unit, "UID validation failed for \""UID_FMT"\"", uid);
2978                         return -ESRCH;
2979                 }
2980
2981                 if (!gid_is_valid(gid)) {
2982                         *exit_status = EXIT_USER;
2983                         log_unit_error(unit, "GID validation failed for \""GID_FMT"\"", gid);
2984                         return -ESRCH;
2985                 }
2986
2987                 if (dcreds->user)
2988                         username = dcreds->user->name;
2989
2990         } else {
2991                 r = get_fixed_user(context, &username, &uid, &gid, &home, &shell);
2992                 if (r < 0) {
2993                         *exit_status = EXIT_USER;
2994                         return log_unit_error_errno(unit, r, "Failed to determine user credentials: %m");
2995                 }
2996
2997                 r = get_fixed_group(context, &groupname, &gid);
2998                 if (r < 0) {
2999                         *exit_status = EXIT_GROUP;
3000                         return log_unit_error_errno(unit, r, "Failed to determine group credentials: %m");
3001                 }
3002         }
3003
3004         /* Initialize user supplementary groups and get SupplementaryGroups= ones */
3005         r = get_supplementary_groups(context, username, groupname, gid,
3006                                      &supplementary_gids, &ngids);
3007         if (r < 0) {
3008                 *exit_status = EXIT_GROUP;
3009                 return log_unit_error_errno(unit, r, "Failed to determine supplementary groups: %m");
3010         }
3011
3012         r = send_user_lookup(unit, user_lookup_fd, uid, gid);
3013         if (r < 0) {
3014                 *exit_status = EXIT_USER;
3015                 return log_unit_error_errno(unit, r, "Failed to send user credentials to PID1: %m");
3016         }
3017
3018         user_lookup_fd = safe_close(user_lookup_fd);
3019
3020         r = acquire_home(context, uid, &home, &home_buffer);
3021         if (r < 0) {
3022                 *exit_status = EXIT_CHDIR;
3023                 return log_unit_error_errno(unit, r, "Failed to determine $HOME for user: %m");
3024         }
3025
3026         /* If a socket is connected to STDIN/STDOUT/STDERR, we
3027          * must sure to drop O_NONBLOCK */
3028         if (socket_fd >= 0)
3029                 (void) fd_nonblock(socket_fd, false);
3030
3031         r = setup_input(context, params, socket_fd, named_iofds);
3032         if (r < 0) {
3033                 *exit_status = EXIT_STDIN;
3034                 return log_unit_error_errno(unit, r, "Failed to set up standard input: %m");
3035         }
3036
3037         r = setup_output(unit, context, params, STDOUT_FILENO, socket_fd, named_iofds, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
3038         if (r < 0) {
3039                 *exit_status = EXIT_STDOUT;
3040                 return log_unit_error_errno(unit, r, "Failed to set up standard output: %m");
3041         }
3042
3043         r = setup_output(unit, context, params, STDERR_FILENO, socket_fd, named_iofds, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
3044         if (r < 0) {
3045                 *exit_status = EXIT_STDERR;
3046                 return log_unit_error_errno(unit, r, "Failed to set up standard error output: %m");
3047         }
3048
3049         if (params->cgroup_path) {
3050                 _cleanup_free_ char *p = NULL;
3051
3052                 r = exec_parameters_get_cgroup_path(params, &p);
3053                 if (r < 0) {
3054                         *exit_status = EXIT_CGROUP;
3055                         return log_unit_error_errno(unit, r, "Failed to acquire cgroup path: %m");
3056                 }
3057
3058                 r = cg_attach_everywhere(params->cgroup_supported, p, 0, NULL, NULL);
3059                 if (r < 0) {
3060                         *exit_status = EXIT_CGROUP;
3061                         return log_unit_error_errno(unit, r, "Failed to attach to cgroup %s: %m", p);
3062                 }
3063         }
3064
3065         if (context->oom_score_adjust_set) {
3066                 /* When we can't make this change due to EPERM, then let's silently skip over it. User namespaces
3067                  * prohibit write access to this file, and we shouldn't trip up over that. */
3068                 r = set_oom_score_adjust(context->oom_score_adjust);
3069                 if (IN_SET(r, -EPERM, -EACCES))
3070                         log_unit_debug_errno(unit, r, "Failed to adjust OOM setting, assuming containerized execution, ignoring: %m");
3071                 else if (r < 0) {
3072                         *exit_status = EXIT_OOM_ADJUST;
3073                         return log_unit_error_errno(unit, r, "Failed to adjust OOM setting: %m");
3074                 }
3075         }
3076
3077         if (context->nice_set)
3078                 if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
3079                         *exit_status = EXIT_NICE;
3080                         return log_unit_error_errno(unit, errno, "Failed to set up process scheduling priority (nice level): %m");
3081                 }
3082
3083         if (context->cpu_sched_set) {
3084                 struct sched_param param = {
3085                         .sched_priority = context->cpu_sched_priority,
3086                 };
3087
3088                 r = sched_setscheduler(0,
3089                                        context->cpu_sched_policy |
3090                                        (context->cpu_sched_reset_on_fork ?
3091                                         SCHED_RESET_ON_FORK : 0),
3092                                        &param);
3093                 if (r < 0) {
3094                         *exit_status = EXIT_SETSCHEDULER;
3095                         return log_unit_error_errno(unit, errno, "Failed to set up CPU scheduling: %m");
3096                 }
3097         }
3098
3099         if (context->cpuset)
3100                 if (sched_setaffinity(0, CPU_ALLOC_SIZE(context->cpuset_ncpus), context->cpuset) < 0) {
3101                         *exit_status = EXIT_CPUAFFINITY;
3102                         return log_unit_error_errno(unit, errno, "Failed to set up CPU affinity: %m");
3103                 }
3104
3105         if (context->ioprio_set)
3106                 if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {
3107                         *exit_status = EXIT_IOPRIO;
3108                         return log_unit_error_errno(unit, errno, "Failed to set up IO scheduling priority: %m");
3109                 }
3110
3111         if (context->timer_slack_nsec != NSEC_INFINITY)
3112                 if (prctl(PR_SET_TIMERSLACK, context->timer_slack_nsec) < 0) {
3113                         *exit_status = EXIT_TIMERSLACK;
3114                         return log_unit_error_errno(unit, errno, "Failed to set up timer slack: %m");
3115                 }
3116
3117         if (context->personality != PERSONALITY_INVALID) {
3118                 r = safe_personality(context->personality);
3119                 if (r < 0) {
3120                         *exit_status = EXIT_PERSONALITY;
3121                         return log_unit_error_errno(unit, r, "Failed to set up execution domain (personality): %m");
3122                 }
3123         }
3124
3125         if (context->utmp_id)
3126                 utmp_put_init_process(context->utmp_id, getpid_cached(), getsid(0),
3127                                       context->tty_path,
3128                                       context->utmp_mode == EXEC_UTMP_INIT  ? INIT_PROCESS :
3129                                       context->utmp_mode == EXEC_UTMP_LOGIN ? LOGIN_PROCESS :
3130                                       USER_PROCESS,
3131                                       username);
3132
3133         if (context->user) {
3134                 r = chown_terminal(STDIN_FILENO, uid);
3135                 if (r < 0) {
3136                         *exit_status = EXIT_STDIN;
3137                         return log_unit_error_errno(unit, r, "Failed to change ownership of terminal: %m");
3138                 }
3139         }
3140
3141         /* If delegation is enabled we'll pass ownership of the cgroup to the user of the new process. On cgroupsv1
3142          * this is only about systemd's own hierarchy, i.e. not the controller hierarchies, simply because that's not
3143          * safe. On cgroupsv2 there's only one hierarchy anyway, and delegation is safe there, hence in that case only
3144          * touch a single hierarchy too. */
3145         if (params->cgroup_path && context->user && (params->flags & EXEC_CGROUP_DELEGATE)) {
3146                 r = cg_set_access(SYSTEMD_CGROUP_CONTROLLER, params->cgroup_path, uid, gid);
3147                 if (r < 0) {
3148                         *exit_status = EXIT_CGROUP;
3149                         return log_unit_error_errno(unit, r, "Failed to adjust control group access: %m");
3150                 }
3151         }
3152
3153         for (dt = 0; dt < _EXEC_DIRECTORY_TYPE_MAX; dt++) {
3154                 r = setup_exec_directory(context, params, uid, gid, dt, exit_status);
3155                 if (r < 0)
3156                         return log_unit_error_errno(unit, r, "Failed to set up special execution directory in %s: %m", params->prefix[dt]);
3157         }
3158
3159         r = build_environment(
3160                         unit,
3161                         context,
3162                         params,
3163                         n_fds,
3164                         home,
3165                         username,
3166                         shell,
3167                         journal_stream_dev,
3168                         journal_stream_ino,
3169                         &our_env);
3170         if (r < 0) {
3171                 *exit_status = EXIT_MEMORY;
3172                 return log_oom();
3173         }
3174
3175         r = build_pass_environment(context, &pass_env);
3176         if (r < 0) {
3177                 *exit_status = EXIT_MEMORY;
3178                 return log_oom();
3179         }
3180
3181         accum_env = strv_env_merge(5,
3182                                    params->environment,
3183                                    our_env,
3184                                    pass_env,
3185                                    context->environment,
3186                                    files_env,
3187                                    NULL);
3188         if (!accum_env) {
3189                 *exit_status = EXIT_MEMORY;
3190                 return log_oom();
3191         }
3192         accum_env = strv_env_clean(accum_env);
3193
3194         (void) umask(context->umask);
3195
3196         r = setup_keyring(unit, context, params, uid, gid);
3197         if (r < 0) {
3198                 *exit_status = EXIT_KEYRING;
3199                 return log_unit_error_errno(unit, r, "Failed to set up kernel keyring: %m");
3200         }
3201
3202         /* We need sandboxing if the caller asked us to apply it and the command isn't explicitly excepted from it */
3203         needs_sandboxing = (params->flags & EXEC_APPLY_SANDBOXING) && !(command->flags & EXEC_COMMAND_FULLY_PRIVILEGED);
3204
3205         /* 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 */
3206         needs_ambient_hack = (params->flags & EXEC_APPLY_SANDBOXING) && (command->flags & EXEC_COMMAND_AMBIENT_MAGIC) && !ambient_capabilities_supported();
3207
3208         /* 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 */
3209         if (needs_ambient_hack)
3210                 needs_setuid = false;
3211         else
3212                 needs_setuid = (params->flags & EXEC_APPLY_SANDBOXING) && !(command->flags & (EXEC_COMMAND_FULLY_PRIVILEGED|EXEC_COMMAND_NO_SETUID));
3213
3214         if (needs_sandboxing) {
3215                 /* MAC enablement checks need to be done before a new mount ns is created, as they rely on /sys being
3216                  * present. The actual MAC context application will happen later, as late as possible, to avoid
3217                  * impacting our own code paths. */
3218
3219 #if HAVE_SELINUX
3220                 use_selinux = mac_selinux_use();
3221 #endif
3222 #if ENABLE_SMACK
3223                 use_smack = mac_smack_use();
3224 #endif
3225 #if HAVE_APPARMOR
3226                 use_apparmor = mac_apparmor_use();
3227 #endif
3228         }
3229
3230         if (needs_setuid) {
3231                 if (context->pam_name && username) {
3232                         r = setup_pam(context->pam_name, username, uid, gid, context->tty_path, &accum_env, fds, n_fds);
3233                         if (r < 0) {
3234                                 *exit_status = EXIT_PAM;
3235                                 return log_unit_error_errno(unit, r, "Failed to set up PAM session: %m");
3236                         }
3237                 }
3238         }
3239
3240         if (context->private_network && runtime && runtime->netns_storage_socket[0] >= 0) {
3241                 if (ns_type_supported(NAMESPACE_NET)) {
3242                         r = setup_netns(runtime->netns_storage_socket);
3243                         if (r < 0) {
3244                                 *exit_status = EXIT_NETWORK;
3245                                 return log_unit_error_errno(unit, r, "Failed to set up network namespacing: %m");
3246                         }
3247                 } else
3248                         log_unit_warning(unit, "PrivateNetwork=yes is configured, but the kernel does not support network namespaces, ignoring.");
3249         }
3250
3251         needs_mount_namespace = exec_needs_mount_namespace(context, params, runtime);
3252         if (needs_mount_namespace) {
3253                 r = apply_mount_namespace(unit, command, context, params, runtime);
3254                 if (r < 0) {
3255                         *exit_status = EXIT_NAMESPACE;
3256                         return log_unit_error_errno(unit, r, "Failed to set up mount namespacing: %m");
3257                 }
3258         }
3259
3260         /* Drop groups as early as possbile */
3261         if (needs_setuid) {
3262                 r = enforce_groups(gid, supplementary_gids, ngids);
3263                 if (r < 0) {
3264                         *exit_status = EXIT_GROUP;
3265                         return log_unit_error_errno(unit, r, "Changing group credentials failed: %m");
3266                 }
3267         }
3268
3269         if (needs_sandboxing) {
3270 #if HAVE_SELINUX
3271                 if (use_selinux && params->selinux_context_net && socket_fd >= 0) {
3272                         r = mac_selinux_get_child_mls_label(socket_fd, command->path, context->selinux_context, &mac_selinux_context_net);
3273                         if (r < 0) {
3274                                 *exit_status = EXIT_SELINUX_CONTEXT;
3275                                 return log_unit_error_errno(unit, r, "Failed to determine SELinux context: %m");
3276                         }
3277                 }
3278 #endif
3279
3280                 if (context->private_users) {
3281                         r = setup_private_users(uid, gid);
3282                         if (r < 0) {
3283                                 *exit_status = EXIT_USER;
3284                                 return log_unit_error_errno(unit, r, "Failed to set up user namespacing: %m");
3285                         }
3286                 }
3287         }
3288
3289         /* We repeat the fd closing here, to make sure that nothing is leaked from the PAM modules. Note that we are
3290          * more aggressive this time since socket_fd and the netns fds we don't need anymore. We do keep the exec_fd
3291          * however if we have it as we want to keep it open until the final execve(). */
3292
3293         if (params->exec_fd >= 0) {
3294                 exec_fd = params->exec_fd;
3295
3296                 if (exec_fd < 3 + (int) n_fds) {
3297                         int moved_fd;
3298
3299                         /* Let's move the exec fd far up, so that it's outside of the fd range we want to pass to the
3300                          * process we are about to execute. */
3301
3302                         moved_fd = fcntl(exec_fd, F_DUPFD_CLOEXEC, 3 + (int) n_fds);
3303                         if (moved_fd < 0) {
3304                                 *exit_status = EXIT_FDS;
3305                                 return log_unit_error_errno(unit, errno, "Couldn't move exec fd up: %m");
3306                         }
3307
3308                         safe_close(exec_fd);
3309                         exec_fd = moved_fd;
3310                 } else {
3311                         /* This fd should be FD_CLOEXEC already, but let's make sure. */
3312                         r = fd_cloexec(exec_fd, true);
3313                         if (r < 0) {
3314                                 *exit_status = EXIT_FDS;
3315                                 return log_unit_error_errno(unit, r, "Failed to make exec fd FD_CLOEXEC: %m");
3316                         }
3317                 }
3318
3319                 fds_with_exec_fd = newa(int, n_fds + 1);
3320                 memcpy_safe(fds_with_exec_fd, fds, n_fds * sizeof(int));
3321                 fds_with_exec_fd[n_fds] = exec_fd;
3322                 n_fds_with_exec_fd = n_fds + 1;
3323         } else {
3324                 fds_with_exec_fd = fds;
3325                 n_fds_with_exec_fd = n_fds;
3326         }
3327
3328         r = close_all_fds(fds_with_exec_fd, n_fds_with_exec_fd);
3329         if (r >= 0)
3330                 r = shift_fds(fds, n_fds);
3331         if (r >= 0)
3332                 r = flags_fds(fds, n_socket_fds, n_storage_fds, context->non_blocking);
3333         if (r < 0) {
3334                 *exit_status = EXIT_FDS;
3335                 return log_unit_error_errno(unit, r, "Failed to adjust passed file descriptors: %m");
3336         }
3337
3338         /* At this point, the fds we want to pass to the program are all ready and set up, with O_CLOEXEC turned off
3339          * and at the right fd numbers. The are no other fds open, with one exception: the exec_fd if it is defined,
3340          * and it has O_CLOEXEC set, after all we want it to be closed by the execve(), so that our parent knows we
3341          * came this far. */
3342
3343         secure_bits = context->secure_bits;
3344
3345         if (needs_sandboxing) {
3346                 uint64_t bset;
3347                 int which_failed;
3348
3349                 r = setrlimit_closest_all((const struct rlimit* const *) context->rlimit, &which_failed);
3350                 if (r < 0) {
3351                         *exit_status = EXIT_LIMITS;
3352                         return log_unit_error_errno(unit, r, "Failed to adjust resource limit RLIMIT_%s: %m", rlimit_to_string(which_failed));
3353                 }
3354
3355                 /* Set the RTPRIO resource limit to 0, but only if nothing else was explicitly requested. */
3356                 if (context->restrict_realtime && !context->rlimit[RLIMIT_RTPRIO]) {
3357                         if (setrlimit(RLIMIT_RTPRIO, &RLIMIT_MAKE_CONST(0)) < 0) {
3358                                 *exit_status = EXIT_LIMITS;
3359                                 return log_unit_error_errno(unit, errno, "Failed to adjust RLIMIT_RTPRIO resource limit: %m");
3360                         }
3361                 }
3362
3363 #if ENABLE_SMACK
3364                 /* LSM Smack needs the capability CAP_MAC_ADMIN to change the current execution security context of the
3365                  * process. This is the latest place before dropping capabilities. Other MAC context are set later. */
3366                 if (use_smack) {
3367                         r = setup_smack(context, command);
3368                         if (r < 0) {
3369                                 *exit_status = EXIT_SMACK_PROCESS_LABEL;
3370                                 return log_unit_error_errno(unit, r, "Failed to set SMACK process label: %m");
3371                         }
3372                 }
3373 #endif
3374
3375                 bset = context->capability_bounding_set;
3376                 /* If the ambient caps hack is enabled (which means the kernel can't do them, and the user asked for
3377                  * our magic fallback), then let's add some extra caps, so that the service can drop privs of its own,
3378                  * instead of us doing that */
3379                 if (needs_ambient_hack)
3380                         bset |= (UINT64_C(1) << CAP_SETPCAP) |
3381                                 (UINT64_C(1) << CAP_SETUID) |
3382                                 (UINT64_C(1) << CAP_SETGID);
3383
3384                 if (!cap_test_all(bset)) {
3385                         r = capability_bounding_set_drop(bset, false);
3386                         if (r < 0) {
3387                                 *exit_status = EXIT_CAPABILITIES;
3388                                 return log_unit_error_errno(unit, r, "Failed to drop capabilities: %m");
3389                         }
3390                 }
3391
3392                 /* This is done before enforce_user, but ambient set
3393                  * does not survive over setresuid() if keep_caps is not set. */
3394                 if (!needs_ambient_hack &&
3395                     context->capability_ambient_set != 0) {
3396                         r = capability_ambient_set_apply(context->capability_ambient_set, true);
3397                         if (r < 0) {
3398                                 *exit_status = EXIT_CAPABILITIES;
3399                                 return log_unit_error_errno(unit, r, "Failed to apply ambient capabilities (before UID change): %m");
3400                         }
3401                 }
3402         }
3403
3404         if (needs_setuid) {
3405                 if (context->user) {
3406                         r = enforce_user(context, uid);
3407                         if (r < 0) {
3408                                 *exit_status = EXIT_USER;
3409                                 return log_unit_error_errno(unit, r, "Failed to change UID to " UID_FMT ": %m", uid);
3410                         }
3411
3412                         if (!needs_ambient_hack &&
3413                             context->capability_ambient_set != 0) {
3414
3415                                 /* Fix the ambient capabilities after user change. */
3416                                 r = capability_ambient_set_apply(context->capability_ambient_set, false);
3417                                 if (r < 0) {
3418                                         *exit_status = EXIT_CAPABILITIES;
3419                                         return log_unit_error_errno(unit, r, "Failed to apply ambient capabilities (after UID change): %m");
3420                                 }
3421
3422                                 /* If we were asked to change user and ambient capabilities
3423                                  * were requested, we had to add keep-caps to the securebits
3424                                  * so that we would maintain the inherited capability set
3425                                  * through the setresuid(). Make sure that the bit is added
3426                                  * also to the context secure_bits so that we don't try to
3427                                  * drop the bit away next. */
3428
3429                                 secure_bits |= 1<<SECURE_KEEP_CAPS;
3430                         }
3431                 }
3432         }
3433
3434         /* Apply working directory here, because the working directory might be on NFS and only the user running
3435          * this service might have the correct privilege to change to the working directory */
3436         r = apply_working_directory(context, params, home, needs_mount_namespace, exit_status);
3437         if (r < 0)
3438                 return log_unit_error_errno(unit, r, "Changing to the requested working directory failed: %m");
3439
3440         if (needs_sandboxing) {
3441                 /* Apply other MAC contexts late, but before seccomp syscall filtering, as those should really be last to
3442                  * influence our own codepaths as little as possible. Moreover, applying MAC contexts usually requires
3443                  * syscalls that are subject to seccomp filtering, hence should probably be applied before the syscalls
3444                  * are restricted. */
3445
3446 #if HAVE_SELINUX
3447                 if (use_selinux) {
3448                         char *exec_context = mac_selinux_context_net ?: context->selinux_context;
3449
3450                         if (exec_context) {
3451                                 r = setexeccon(exec_context);
3452                                 if (r < 0) {
3453                                         *exit_status = EXIT_SELINUX_CONTEXT;
3454                                         return log_unit_error_errno(unit, r, "Failed to change SELinux context to %s: %m", exec_context);
3455                                 }
3456                         }
3457                 }
3458 #endif
3459
3460 #if HAVE_APPARMOR
3461                 if (use_apparmor && context->apparmor_profile) {
3462                         r = aa_change_onexec(context->apparmor_profile);
3463                         if (r < 0 && !context->apparmor_profile_ignore) {
3464                                 *exit_status = EXIT_APPARMOR_PROFILE;
3465                                 return log_unit_error_errno(unit, errno, "Failed to prepare AppArmor profile change to %s: %m", context->apparmor_profile);
3466                         }
3467                 }
3468 #endif
3469
3470                 /* PR_GET_SECUREBITS is not privileged, while PR_SET_SECUREBITS is. So to suppress potential EPERMs
3471                  * we'll try not to call PR_SET_SECUREBITS unless necessary. */
3472                 if (prctl(PR_GET_SECUREBITS) != secure_bits)
3473                         if (prctl(PR_SET_SECUREBITS, secure_bits) < 0) {
3474                                 *exit_status = EXIT_SECUREBITS;
3475                                 return log_unit_error_errno(unit, errno, "Failed to set process secure bits: %m");
3476                         }
3477
3478                 if (context_has_no_new_privileges(context))
3479                         if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
3480                                 *exit_status = EXIT_NO_NEW_PRIVILEGES;
3481                                 return log_unit_error_errno(unit, errno, "Failed to disable new privileges: %m");
3482                         }
3483
3484 #if HAVE_SECCOMP
3485                 r = apply_address_families(unit, context);
3486                 if (r < 0) {
3487                         *exit_status = EXIT_ADDRESS_FAMILIES;
3488                         return log_unit_error_errno(unit, r, "Failed to restrict address families: %m");
3489                 }
3490
3491                 r = apply_memory_deny_write_execute(unit, context);
3492                 if (r < 0) {
3493                         *exit_status = EXIT_SECCOMP;
3494                         return log_unit_error_errno(unit, r, "Failed to disable writing to executable memory: %m");
3495                 }
3496
3497                 r = apply_restrict_realtime(unit, context);
3498                 if (r < 0) {
3499                         *exit_status = EXIT_SECCOMP;
3500                         return log_unit_error_errno(unit, r, "Failed to apply realtime restrictions: %m");
3501                 }
3502
3503                 r = apply_restrict_namespaces(unit, context);
3504                 if (r < 0) {
3505                         *exit_status = EXIT_SECCOMP;
3506                         return log_unit_error_errno(unit, r, "Failed to apply namespace restrictions: %m");
3507                 }
3508
3509                 r = apply_protect_sysctl(unit, context);
3510                 if (r < 0) {
3511                         *exit_status = EXIT_SECCOMP;
3512                         return log_unit_error_errno(unit, r, "Failed to apply sysctl restrictions: %m");
3513                 }
3514
3515                 r = apply_protect_kernel_modules(unit, context);
3516                 if (r < 0) {
3517                         *exit_status = EXIT_SECCOMP;
3518                         return log_unit_error_errno(unit, r, "Failed to apply module loading restrictions: %m");
3519                 }
3520
3521                 r = apply_private_devices(unit, context);
3522                 if (r < 0) {
3523                         *exit_status = EXIT_SECCOMP;
3524                         return log_unit_error_errno(unit, r, "Failed to set up private devices: %m");
3525                 }
3526
3527                 r = apply_syscall_archs(unit, context);
3528                 if (r < 0) {
3529                         *exit_status = EXIT_SECCOMP;
3530                         return log_unit_error_errno(unit, r, "Failed to apply syscall architecture restrictions: %m");
3531                 }
3532
3533                 r = apply_lock_personality(unit, context);
3534                 if (r < 0) {
3535                         *exit_status = EXIT_SECCOMP;
3536                         return log_unit_error_errno(unit, r, "Failed to lock personalities: %m");
3537                 }
3538
3539                 /* This really should remain the last step before the execve(), to make sure our own code is unaffected
3540                  * by the filter as little as possible. */
3541                 r = apply_syscall_filter(unit, context, needs_ambient_hack);
3542                 if (r < 0) {
3543                         *exit_status = EXIT_SECCOMP;
3544                         return log_unit_error_errno(unit, r, "Failed to apply system call filters: %m");
3545                 }
3546 #endif
3547         }
3548
3549         if (!strv_isempty(context->unset_environment)) {
3550                 char **ee = NULL;
3551
3552                 ee = strv_env_delete(accum_env, 1, context->unset_environment);
3553                 if (!ee) {
3554                         *exit_status = EXIT_MEMORY;
3555                         return log_oom();
3556                 }
3557
3558                 strv_free_and_replace(accum_env, ee);
3559         }
3560
3561         final_argv = replace_env_argv(command->argv, accum_env);
3562         if (!final_argv) {
3563                 *exit_status = EXIT_MEMORY;
3564                 return log_oom();
3565         }
3566
3567         if (DEBUG_LOGGING) {
3568                 _cleanup_free_ char *line;
3569
3570                 line = exec_command_line(final_argv);
3571                 if (line)
3572                         log_struct(LOG_DEBUG,
3573                                    "EXECUTABLE=%s", command->path,
3574                                    LOG_UNIT_MESSAGE(unit, "Executing: %s", line),
3575                                    LOG_UNIT_ID(unit),
3576                                    LOG_UNIT_INVOCATION_ID(unit));
3577         }
3578
3579         if (exec_fd >= 0) {
3580                 uint8_t hot = 1;
3581
3582                 /* We have finished with all our initializations. Let's now let the manager know that. From this point
3583                  * on, if the manager sees POLLHUP on the exec_fd, then execve() was successful. */
3584
3585                 if (write(exec_fd, &hot, sizeof(hot)) < 0) {
3586                         *exit_status = EXIT_EXEC;
3587                         return log_unit_error_errno(unit, errno, "Failed to enable exec_fd: %m");
3588                 }
3589         }
3590
3591         execve(command->path, final_argv, accum_env);
3592         r = -errno;
3593
3594         if (exec_fd >= 0) {
3595                 uint8_t hot = 0;
3596
3597                 /* The execve() failed. This means the exec_fd is still open. Which means we need to tell the manager
3598                  * that POLLHUP on it no longer means execve() succeeded. */
3599
3600                 if (write(exec_fd, &hot, sizeof(hot)) < 0) {
3601                         *exit_status = EXIT_EXEC;
3602                         return log_unit_error_errno(unit, errno, "Failed to disable exec_fd: %m");
3603                 }
3604         }
3605
3606         if (r == -ENOENT && (command->flags & EXEC_COMMAND_IGNORE_FAILURE)) {
3607                 log_struct_errno(LOG_INFO, r,
3608                                  "MESSAGE_ID=" SD_MESSAGE_SPAWN_FAILED_STR,
3609                                  LOG_UNIT_ID(unit),
3610                                  LOG_UNIT_INVOCATION_ID(unit),
3611                                  LOG_UNIT_MESSAGE(unit, "Executable %s missing, skipping: %m",
3612                                                   command->path),
3613                                  "EXECUTABLE=%s", command->path);
3614                 return 0;
3615         }
3616
3617         *exit_status = EXIT_EXEC;
3618         return log_unit_error_errno(unit, r, "Failed to execute command: %m");
3619 }
3620
3621 static int exec_context_load_environment(const Unit *unit, const ExecContext *c, char ***l);
3622 static int exec_context_named_iofds(const ExecContext *c, const ExecParameters *p, int named_iofds[3]);
3623
3624 int exec_spawn(Unit *unit,
3625                ExecCommand *command,
3626                const ExecContext *context,
3627                const ExecParameters *params,
3628                ExecRuntime *runtime,
3629                DynamicCreds *dcreds,
3630                pid_t *ret) {
3631
3632         int socket_fd, r, named_iofds[3] = { -1, -1, -1 }, *fds = NULL;
3633         _cleanup_free_ char *subcgroup_path = NULL;
3634         _cleanup_strv_free_ char **files_env = NULL;
3635         size_t n_storage_fds = 0, n_socket_fds = 0;
3636         _cleanup_free_ char *line = NULL;
3637         pid_t pid;
3638
3639         assert(unit);
3640         assert(command);
3641         assert(context);
3642         assert(ret);
3643         assert(params);
3644         assert(params->fds || (params->n_socket_fds + params->n_storage_fds <= 0));
3645
3646         if (context->std_input == EXEC_INPUT_SOCKET ||
3647             context->std_output == EXEC_OUTPUT_SOCKET ||
3648             context->std_error == EXEC_OUTPUT_SOCKET) {
3649
3650                 if (params->n_socket_fds > 1) {
3651                         log_unit_error(unit, "Got more than one socket.");
3652                         return -EINVAL;
3653                 }
3654
3655                 if (params->n_socket_fds == 0) {
3656                         log_unit_error(unit, "Got no socket.");
3657                         return -EINVAL;
3658                 }
3659
3660                 socket_fd = params->fds[0];
3661         } else {
3662                 socket_fd = -1;
3663                 fds = params->fds;
3664                 n_socket_fds = params->n_socket_fds;
3665                 n_storage_fds = params->n_storage_fds;
3666         }
3667
3668         r = exec_context_named_iofds(context, params, named_iofds);
3669         if (r < 0)
3670                 return log_unit_error_errno(unit, r, "Failed to load a named file descriptor: %m");
3671
3672         r = exec_context_load_environment(unit, context, &files_env);
3673         if (r < 0)
3674                 return log_unit_error_errno(unit, r, "Failed to load environment files: %m");
3675
3676         line = exec_command_line(command->argv);
3677         if (!line)
3678                 return log_oom();
3679
3680         log_struct(LOG_DEBUG,
3681                    LOG_UNIT_MESSAGE(unit, "About to execute: %s", line),
3682                    "EXECUTABLE=%s", command->path,
3683                    LOG_UNIT_ID(unit),
3684                    LOG_UNIT_INVOCATION_ID(unit));
3685
3686         if (params->cgroup_path) {
3687                 r = exec_parameters_get_cgroup_path(params, &subcgroup_path);
3688                 if (r < 0)
3689                         return log_unit_error_errno(unit, r, "Failed to acquire subcgroup path: %m");
3690                 if (r > 0) { /* We are using a child cgroup */
3691                         r = cg_create(SYSTEMD_CGROUP_CONTROLLER, subcgroup_path);
3692                         if (r < 0)
3693                                 return log_unit_error_errno(unit, r, "Failed to create control group '%s': %m", subcgroup_path);
3694                 }
3695         }
3696
3697         pid = fork();
3698         if (pid < 0)
3699                 return log_unit_error_errno(unit, errno, "Failed to fork: %m");
3700
3701         if (pid == 0) {
3702                 int exit_status = EXIT_SUCCESS;
3703
3704                 r = exec_child(unit,
3705                                command,
3706                                context,
3707                                params,
3708                                runtime,
3709                                dcreds,
3710                                socket_fd,
3711                                named_iofds,
3712                                fds,
3713                                n_socket_fds,
3714                                n_storage_fds,
3715                                files_env,
3716                                unit->manager->user_lookup_fds[1],
3717                                &exit_status);
3718
3719                 if (r < 0)
3720                         log_struct_errno(LOG_ERR, r,
3721                                          "MESSAGE_ID=" SD_MESSAGE_SPAWN_FAILED_STR,
3722                                          LOG_UNIT_ID(unit),
3723                                          LOG_UNIT_INVOCATION_ID(unit),
3724                                          LOG_UNIT_MESSAGE(unit, "Failed at step %s spawning %s: %m",
3725                                                           exit_status_to_string(exit_status, EXIT_STATUS_SYSTEMD),
3726                                                           command->path),
3727                                          "EXECUTABLE=%s", command->path);
3728
3729                 _exit(exit_status);
3730         }
3731
3732         log_unit_debug(unit, "Forked %s as "PID_FMT, command->path, pid);
3733
3734         /* We add the new process to the cgroup both in the child (so that we can be sure that no user code is ever
3735          * executed outside of the cgroup) and in the parent (so that we can be sure that when we kill the cgroup the
3736          * process will be killed too). */
3737         if (subcgroup_path)
3738                 (void) cg_attach(SYSTEMD_CGROUP_CONTROLLER, subcgroup_path, pid);
3739
3740         exec_status_start(&command->exec_status, pid);
3741
3742         *ret = pid;
3743         return 0;
3744 }
3745
3746 void exec_context_init(ExecContext *c) {
3747         ExecDirectoryType i;
3748
3749         assert(c);
3750
3751         c->umask = 0022;
3752         c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);
3753         c->cpu_sched_policy = SCHED_OTHER;
3754         c->syslog_priority = LOG_DAEMON|LOG_INFO;
3755         c->syslog_level_prefix = true;
3756         c->ignore_sigpipe = true;
3757         c->timer_slack_nsec = NSEC_INFINITY;
3758         c->personality = PERSONALITY_INVALID;
3759         for (i = 0; i < _EXEC_DIRECTORY_TYPE_MAX; i++)
3760                 c->directories[i].mode = 0755;
3761         c->capability_bounding_set = CAP_ALL;
3762         assert_cc(NAMESPACE_FLAGS_INITIAL != NAMESPACE_FLAGS_ALL);
3763         c->restrict_namespaces = NAMESPACE_FLAGS_INITIAL;
3764         c->log_level_max = -1;
3765 }
3766
3767 void exec_context_done(ExecContext *c) {
3768         ExecDirectoryType i;
3769         size_t l;
3770
3771         assert(c);
3772
3773         c->environment = strv_free(c->environment);
3774         c->environment_files = strv_free(c->environment_files);
3775         c->pass_environment = strv_free(c->pass_environment);
3776         c->unset_environment = strv_free(c->unset_environment);
3777
3778         rlimit_free_all(c->rlimit);
3779
3780         for (l = 0; l < 3; l++) {
3781                 c->stdio_fdname[l] = mfree(c->stdio_fdname[l]);
3782                 c->stdio_file[l] = mfree(c->stdio_file[l]);
3783         }
3784
3785         c->working_directory = mfree(c->working_directory);
3786         c->root_directory = mfree(c->root_directory);
3787         c->root_image = mfree(c->root_image);
3788         c->tty_path = mfree(c->tty_path);
3789         c->syslog_identifier = mfree(c->syslog_identifier);
3790         c->user = mfree(c->user);
3791         c->group = mfree(c->group);
3792
3793         c->supplementary_groups = strv_free(c->supplementary_groups);
3794
3795         c->pam_name = mfree(c->pam_name);
3796
3797         c->read_only_paths = strv_free(c->read_only_paths);
3798         c->read_write_paths = strv_free(c->read_write_paths);
3799         c->inaccessible_paths = strv_free(c->inaccessible_paths);
3800
3801         bind_mount_free_many(c->bind_mounts, c->n_bind_mounts);
3802         c->bind_mounts = NULL;
3803         c->n_bind_mounts = 0;
3804         temporary_filesystem_free_many(c->temporary_filesystems, c->n_temporary_filesystems);
3805         c->temporary_filesystems = NULL;
3806         c->n_temporary_filesystems = 0;
3807
3808         c->cpuset = cpu_set_mfree(c->cpuset);
3809
3810         c->utmp_id = mfree(c->utmp_id);
3811         c->selinux_context = mfree(c->selinux_context);
3812         c->apparmor_profile = mfree(c->apparmor_profile);
3813         c->smack_process_label = mfree(c->smack_process_label);
3814
3815         c->syscall_filter = hashmap_free(c->syscall_filter);
3816         c->syscall_archs = set_free(c->syscall_archs);
3817         c->address_families = set_free(c->address_families);
3818
3819         for (i = 0; i < _EXEC_DIRECTORY_TYPE_MAX; i++)
3820                 c->directories[i].paths = strv_free(c->directories[i].paths);
3821
3822         c->log_level_max = -1;
3823
3824         exec_context_free_log_extra_fields(c);
3825
3826         c->log_rate_limit_interval_usec = 0;
3827         c->log_rate_limit_burst = 0;
3828
3829         c->stdin_data = mfree(c->stdin_data);
3830         c->stdin_data_size = 0;
3831 }
3832
3833 int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_prefix) {
3834         char **i;
3835
3836         assert(c);
3837
3838         if (!runtime_prefix)
3839                 return 0;
3840
3841         STRV_FOREACH(i, c->directories[EXEC_DIRECTORY_RUNTIME].paths) {
3842                 _cleanup_free_ char *p;
3843
3844                 p = strjoin(runtime_prefix, "/", *i);
3845                 if (!p)
3846                         return -ENOMEM;
3847
3848                 /* We execute this synchronously, since we need to be sure this is gone when we start the service
3849                  * next. */
3850                 (void) rm_rf(p, REMOVE_ROOT);
3851         }
3852
3853         return 0;
3854 }
3855
3856 static void exec_command_done(ExecCommand *c) {
3857         assert(c);
3858
3859         c->path = mfree(c->path);
3860         c->argv = strv_free(c->argv);
3861 }
3862
3863 void exec_command_done_array(ExecCommand *c, size_t n) {
3864         size_t i;
3865
3866         for (i = 0; i < n; i++)
3867                 exec_command_done(c+i);
3868 }
3869
3870 ExecCommand* exec_command_free_list(ExecCommand *c) {
3871         ExecCommand *i;
3872
3873         while ((i = c)) {
3874                 LIST_REMOVE(command, c, i);
3875                 exec_command_done(i);
3876                 free(i);
3877         }
3878
3879         return NULL;
3880 }
3881
3882 void exec_command_free_array(ExecCommand **c, size_t n) {
3883         size_t i;
3884
3885         for (i = 0; i < n; i++)
3886                 c[i] = exec_command_free_list(c[i]);
3887 }
3888
3889 void exec_command_reset_status_array(ExecCommand *c, size_t n) {
3890         size_t i;
3891
3892         for (i = 0; i < n; i++)
3893                 exec_status_reset(&c[i].exec_status);
3894 }
3895
3896 void exec_command_reset_status_list_array(ExecCommand **c, size_t n) {
3897         size_t i;
3898
3899         for (i = 0; i < n; i++) {
3900                 ExecCommand *z;
3901
3902                 LIST_FOREACH(command, z, c[i])
3903                         exec_status_reset(&z->exec_status);
3904         }
3905 }
3906
3907 typedef struct InvalidEnvInfo {
3908         const Unit *unit;
3909         const char *path;
3910 } InvalidEnvInfo;
3911
3912 static void invalid_env(const char *p, void *userdata) {
3913         InvalidEnvInfo *info = userdata;
3914
3915         log_unit_error(info->unit, "Ignoring invalid environment assignment '%s': %s", p, info->path);
3916 }
3917
3918 const char* exec_context_fdname(const ExecContext *c, int fd_index) {
3919         assert(c);
3920
3921         switch (fd_index) {
3922
3923         case STDIN_FILENO:
3924                 if (c->std_input != EXEC_INPUT_NAMED_FD)
3925                         return NULL;
3926
3927                 return c->stdio_fdname[STDIN_FILENO] ?: "stdin";
3928
3929         case STDOUT_FILENO:
3930                 if (c->std_output != EXEC_OUTPUT_NAMED_FD)
3931                         return NULL;
3932
3933                 return c->stdio_fdname[STDOUT_FILENO] ?: "stdout";
3934
3935         case STDERR_FILENO:
3936                 if (c->std_error != EXEC_OUTPUT_NAMED_FD)
3937                         return NULL;
3938
3939                 return c->stdio_fdname[STDERR_FILENO] ?: "stderr";
3940
3941         default:
3942                 return NULL;
3943         }
3944 }
3945
3946 static int exec_context_named_iofds(const ExecContext *c, const ExecParameters *p, int named_iofds[3]) {
3947         size_t i, targets;
3948         const char* stdio_fdname[3];
3949         size_t n_fds;
3950
3951         assert(c);
3952         assert(p);
3953
3954         targets = (c->std_input == EXEC_INPUT_NAMED_FD) +
3955                   (c->std_output == EXEC_OUTPUT_NAMED_FD) +
3956                   (c->std_error == EXEC_OUTPUT_NAMED_FD);
3957
3958         for (i = 0; i < 3; i++)
3959                 stdio_fdname[i] = exec_context_fdname(c, i);
3960
3961         n_fds = p->n_storage_fds + p->n_socket_fds;
3962
3963         for (i = 0; i < n_fds  && targets > 0; i++)
3964                 if (named_iofds[STDIN_FILENO] < 0 &&
3965                     c->std_input == EXEC_INPUT_NAMED_FD &&
3966                     stdio_fdname[STDIN_FILENO] &&
3967                     streq(p->fd_names[i], stdio_fdname[STDIN_FILENO])) {
3968
3969                         named_iofds[STDIN_FILENO] = p->fds[i];
3970                         targets--;
3971
3972                 } else if (named_iofds[STDOUT_FILENO] < 0 &&
3973                            c->std_output == EXEC_OUTPUT_NAMED_FD &&
3974                            stdio_fdname[STDOUT_FILENO] &&
3975                            streq(p->fd_names[i], stdio_fdname[STDOUT_FILENO])) {
3976
3977                         named_iofds[STDOUT_FILENO] = p->fds[i];
3978                         targets--;
3979
3980                 } else if (named_iofds[STDERR_FILENO] < 0 &&
3981                            c->std_error == EXEC_OUTPUT_NAMED_FD &&
3982                            stdio_fdname[STDERR_FILENO] &&
3983                            streq(p->fd_names[i], stdio_fdname[STDERR_FILENO])) {
3984
3985                         named_iofds[STDERR_FILENO] = p->fds[i];
3986                         targets--;
3987                 }
3988
3989         return targets == 0 ? 0 : -ENOENT;
3990 }
3991
3992 static int exec_context_load_environment(const Unit *unit, const ExecContext *c, char ***l) {
3993         char **i, **r = NULL;
3994
3995         assert(c);
3996         assert(l);
3997
3998         STRV_FOREACH(i, c->environment_files) {
3999                 char *fn;
4000                 int k;
4001                 unsigned n;
4002                 bool ignore = false;
4003                 char **p;
4004                 _cleanup_globfree_ glob_t pglob = {};
4005
4006                 fn = *i;
4007
4008                 if (fn[0] == '-') {
4009                         ignore = true;
4010                         fn++;
4011                 }
4012
4013                 if (!path_is_absolute(fn)) {
4014                         if (ignore)
4015                                 continue;
4016
4017                         strv_free(r);
4018                         return -EINVAL;
4019                 }
4020
4021                 /* Filename supports globbing, take all matching files */
4022                 k = safe_glob(fn, 0, &pglob);
4023                 if (k < 0) {
4024                         if (ignore)
4025                                 continue;
4026
4027                         strv_free(r);
4028                         return k;
4029                 }
4030
4031                 /* When we don't match anything, -ENOENT should be returned */
4032                 assert(pglob.gl_pathc > 0);
4033
4034                 for (n = 0; n < pglob.gl_pathc; n++) {
4035                         k = load_env_file(NULL, pglob.gl_pathv[n], &p);
4036                         if (k < 0) {
4037                                 if (ignore)
4038                                         continue;
4039
4040                                 strv_free(r);
4041                                 return k;
4042                         }
4043                         /* Log invalid environment variables with filename */
4044                         if (p) {
4045                                 InvalidEnvInfo info = {
4046                                         .unit = unit,
4047                                         .path = pglob.gl_pathv[n]
4048                                 };
4049
4050                                 p = strv_env_clean_with_callback(p, invalid_env, &info);
4051                         }
4052
4053                         if (!r)
4054                                 r = p;
4055                         else {
4056                                 char **m;
4057
4058                                 m = strv_env_merge(2, r, p);
4059                                 strv_free(r);
4060                                 strv_free(p);
4061                                 if (!m)
4062                                         return -ENOMEM;
4063
4064                                 r = m;
4065                         }
4066                 }
4067         }
4068
4069         *l = r;
4070
4071         return 0;
4072 }
4073
4074 static bool tty_may_match_dev_console(const char *tty) {
4075         _cleanup_free_ char *resolved = NULL;
4076
4077         if (!tty)
4078                 return true;
4079
4080         tty = skip_dev_prefix(tty);
4081
4082         /* trivial identity? */
4083         if (streq(tty, "console"))
4084                 return true;
4085
4086         if (resolve_dev_console(&resolved) < 0)
4087                 return true; /* if we could not resolve, assume it may */
4088
4089         /* "tty0" means the active VC, so it may be the same sometimes */
4090         return streq(resolved, tty) || (streq(resolved, "tty0") && tty_is_vc(tty));
4091 }
4092
4093 bool exec_context_may_touch_console(const ExecContext *ec) {
4094
4095         return (ec->tty_reset ||
4096                 ec->tty_vhangup ||
4097                 ec->tty_vt_disallocate ||
4098                 is_terminal_input(ec->std_input) ||
4099                 is_terminal_output(ec->std_output) ||
4100                 is_terminal_output(ec->std_error)) &&
4101                tty_may_match_dev_console(exec_context_tty_path(ec));
4102 }
4103
4104 static void strv_fprintf(FILE *f, char **l) {
4105         char **g;
4106
4107         assert(f);
4108
4109         STRV_FOREACH(g, l)
4110                 fprintf(f, " %s", *g);
4111 }
4112
4113 void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix) {
4114         ExecDirectoryType dt;
4115         char **e, **d;
4116         unsigned i;
4117         int r;
4118
4119         assert(c);
4120         assert(f);
4121
4122         prefix = strempty(prefix);
4123
4124         fprintf(f,
4125                 "%sUMask: %04o\n"
4126                 "%sWorkingDirectory: %s\n"
4127                 "%sRootDirectory: %s\n"
4128                 "%sNonBlocking: %s\n"
4129                 "%sPrivateTmp: %s\n"
4130                 "%sPrivateDevices: %s\n"
4131                 "%sProtectKernelTunables: %s\n"
4132                 "%sProtectKernelModules: %s\n"
4133                 "%sProtectControlGroups: %s\n"
4134                 "%sPrivateNetwork: %s\n"
4135                 "%sPrivateUsers: %s\n"
4136                 "%sProtectHome: %s\n"
4137                 "%sProtectSystem: %s\n"
4138                 "%sMountAPIVFS: %s\n"
4139                 "%sIgnoreSIGPIPE: %s\n"
4140                 "%sMemoryDenyWriteExecute: %s\n"
4141                 "%sRestrictRealtime: %s\n"
4142                 "%sKeyringMode: %s\n",
4143                 prefix, c->umask,
4144                 prefix, c->working_directory ? c->working_directory : "/",
4145                 prefix, c->root_directory ? c->root_directory : "/",
4146                 prefix, yes_no(c->non_blocking),
4147                 prefix, yes_no(c->private_tmp),
4148                 prefix, yes_no(c->private_devices),
4149                 prefix, yes_no(c->protect_kernel_tunables),
4150                 prefix, yes_no(c->protect_kernel_modules),
4151                 prefix, yes_no(c->protect_control_groups),
4152                 prefix, yes_no(c->private_network),
4153                 prefix, yes_no(c->private_users),
4154                 prefix, protect_home_to_string(c->protect_home),
4155                 prefix, protect_system_to_string(c->protect_system),
4156                 prefix, yes_no(c->mount_apivfs),
4157                 prefix, yes_no(c->ignore_sigpipe),
4158                 prefix, yes_no(c->memory_deny_write_execute),
4159                 prefix, yes_no(c->restrict_realtime),
4160                 prefix, exec_keyring_mode_to_string(c->keyring_mode));
4161
4162         if (c->root_image)
4163                 fprintf(f, "%sRootImage: %s\n", prefix, c->root_image);
4164
4165         STRV_FOREACH(e, c->environment)
4166                 fprintf(f, "%sEnvironment: %s\n", prefix, *e);
4167
4168         STRV_FOREACH(e, c->environment_files)
4169                 fprintf(f, "%sEnvironmentFile: %s\n", prefix, *e);
4170
4171         STRV_FOREACH(e, c->pass_environment)
4172                 fprintf(f, "%sPassEnvironment: %s\n", prefix, *e);
4173
4174         STRV_FOREACH(e, c->unset_environment)
4175                 fprintf(f, "%sUnsetEnvironment: %s\n", prefix, *e);
4176
4177         fprintf(f, "%sRuntimeDirectoryPreserve: %s\n", prefix, exec_preserve_mode_to_string(c->runtime_directory_preserve_mode));
4178
4179         for (dt = 0; dt < _EXEC_DIRECTORY_TYPE_MAX; dt++) {
4180                 fprintf(f, "%s%sMode: %04o\n", prefix, exec_directory_type_to_string(dt), c->directories[dt].mode);
4181
4182                 STRV_FOREACH(d, c->directories[dt].paths)
4183                         fprintf(f, "%s%s: %s\n", prefix, exec_directory_type_to_string(dt), *d);
4184         }
4185
4186         if (c->nice_set)
4187                 fprintf(f,
4188                         "%sNice: %i\n",
4189                         prefix, c->nice);
4190
4191         if (c->oom_score_adjust_set)
4192                 fprintf(f,
4193                         "%sOOMScoreAdjust: %i\n",
4194                         prefix, c->oom_score_adjust);
4195
4196         for (i = 0; i < RLIM_NLIMITS; i++)
4197                 if (c->rlimit[i]) {
4198                         fprintf(f, "%sLimit%s: " RLIM_FMT "\n",
4199                                 prefix, rlimit_to_string(i), c->rlimit[i]->rlim_max);
4200                         fprintf(f, "%sLimit%sSoft: " RLIM_FMT "\n",
4201                                 prefix, rlimit_to_string(i), c->rlimit[i]->rlim_cur);
4202                 }
4203
4204         if (c->ioprio_set) {
4205                 _cleanup_free_ char *class_str = NULL;
4206
4207                 r = ioprio_class_to_string_alloc(IOPRIO_PRIO_CLASS(c->ioprio), &class_str);
4208                 if (r >= 0)
4209                         fprintf(f, "%sIOSchedulingClass: %s\n", prefix, class_str);
4210
4211                 fprintf(f, "%sIOPriority: %lu\n", prefix, IOPRIO_PRIO_DATA(c->ioprio));
4212         }
4213
4214         if (c->cpu_sched_set) {
4215                 _cleanup_free_ char *policy_str = NULL;
4216
4217                 r = sched_policy_to_string_alloc(c->cpu_sched_policy, &policy_str);
4218                 if (r >= 0)
4219                         fprintf(f, "%sCPUSchedulingPolicy: %s\n", prefix, policy_str);
4220
4221                 fprintf(f,
4222                         "%sCPUSchedulingPriority: %i\n"
4223                         "%sCPUSchedulingResetOnFork: %s\n",
4224                         prefix, c->cpu_sched_priority,
4225                         prefix, yes_no(c->cpu_sched_reset_on_fork));
4226         }
4227
4228         if (c->cpuset) {
4229                 fprintf(f, "%sCPUAffinity:", prefix);
4230                 for (i = 0; i < c->cpuset_ncpus; i++)
4231                         if (CPU_ISSET_S(i, CPU_ALLOC_SIZE(c->cpuset_ncpus), c->cpuset))
4232                                 fprintf(f, " %u", i);
4233                 fputs("\n", f);
4234         }
4235
4236         if (c->timer_slack_nsec != NSEC_INFINITY)
4237                 fprintf(f, "%sTimerSlackNSec: "NSEC_FMT "\n", prefix, c->timer_slack_nsec);
4238
4239         fprintf(f,
4240                 "%sStandardInput: %s\n"
4241                 "%sStandardOutput: %s\n"
4242                 "%sStandardError: %s\n",
4243                 prefix, exec_input_to_string(c->std_input),
4244                 prefix, exec_output_to_string(c->std_output),
4245                 prefix, exec_output_to_string(c->std_error));
4246
4247         if (c->std_input == EXEC_INPUT_NAMED_FD)
4248                 fprintf(f, "%sStandardInputFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDIN_FILENO]);
4249         if (c->std_output == EXEC_OUTPUT_NAMED_FD)
4250                 fprintf(f, "%sStandardOutputFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDOUT_FILENO]);
4251         if (c->std_error == EXEC_OUTPUT_NAMED_FD)
4252                 fprintf(f, "%sStandardErrorFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDERR_FILENO]);
4253
4254         if (c->std_input == EXEC_INPUT_FILE)
4255                 fprintf(f, "%sStandardInputFile: %s\n", prefix, c->stdio_file[STDIN_FILENO]);
4256         if (c->std_output == EXEC_OUTPUT_FILE)
4257                 fprintf(f, "%sStandardOutputFile: %s\n", prefix, c->stdio_file[STDOUT_FILENO]);
4258         if (c->std_output == EXEC_OUTPUT_FILE_APPEND)
4259                 fprintf(f, "%sStandardOutputFileToAppend: %s\n", prefix, c->stdio_file[STDOUT_FILENO]);
4260         if (c->std_error == EXEC_OUTPUT_FILE)
4261                 fprintf(f, "%sStandardErrorFile: %s\n", prefix, c->stdio_file[STDERR_FILENO]);
4262         if (c->std_error == EXEC_OUTPUT_FILE_APPEND)
4263                 fprintf(f, "%sStandardErrorFileToAppend: %s\n", prefix, c->stdio_file[STDERR_FILENO]);
4264
4265         if (c->tty_path)
4266                 fprintf(f,
4267                         "%sTTYPath: %s\n"
4268                         "%sTTYReset: %s\n"
4269                         "%sTTYVHangup: %s\n"
4270                         "%sTTYVTDisallocate: %s\n",
4271                         prefix, c->tty_path,
4272                         prefix, yes_no(c->tty_reset),
4273                         prefix, yes_no(c->tty_vhangup),
4274                         prefix, yes_no(c->tty_vt_disallocate));
4275
4276         if (IN_SET(c->std_output,
4277                    EXEC_OUTPUT_SYSLOG,
4278                    EXEC_OUTPUT_KMSG,
4279                    EXEC_OUTPUT_JOURNAL,
4280                    EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
4281                    EXEC_OUTPUT_KMSG_AND_CONSOLE,
4282                    EXEC_OUTPUT_JOURNAL_AND_CONSOLE) ||
4283             IN_SET(c->std_error,
4284                    EXEC_OUTPUT_SYSLOG,
4285                    EXEC_OUTPUT_KMSG,
4286                    EXEC_OUTPUT_JOURNAL,
4287                    EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
4288                    EXEC_OUTPUT_KMSG_AND_CONSOLE,
4289                    EXEC_OUTPUT_JOURNAL_AND_CONSOLE)) {
4290
4291                 _cleanup_free_ char *fac_str = NULL, *lvl_str = NULL;
4292
4293                 r = log_facility_unshifted_to_string_alloc(c->syslog_priority >> 3, &fac_str);
4294                 if (r >= 0)
4295                         fprintf(f, "%sSyslogFacility: %s\n", prefix, fac_str);
4296
4297                 r = log_level_to_string_alloc(LOG_PRI(c->syslog_priority), &lvl_str);
4298                 if (r >= 0)
4299                         fprintf(f, "%sSyslogLevel: %s\n", prefix, lvl_str);
4300         }
4301
4302         if (c->log_level_max >= 0) {
4303                 _cleanup_free_ char *t = NULL;
4304
4305                 (void) log_level_to_string_alloc(c->log_level_max, &t);
4306
4307                 fprintf(f, "%sLogLevelMax: %s\n", prefix, strna(t));
4308         }
4309
4310         if (c->log_rate_limit_interval_usec > 0) {
4311                 char buf_timespan[FORMAT_TIMESPAN_MAX];
4312
4313                 fprintf(f,
4314                         "%sLogRateLimitIntervalSec: %s\n",
4315                         prefix, format_timespan(buf_timespan, sizeof(buf_timespan), c->log_rate_limit_interval_usec, USEC_PER_SEC));
4316         }
4317
4318         if (c->log_rate_limit_burst > 0)
4319                 fprintf(f, "%sLogRateLimitBurst: %u\n", prefix, c->log_rate_limit_burst);
4320
4321         if (c->n_log_extra_fields > 0) {
4322                 size_t j;
4323
4324                 for (j = 0; j < c->n_log_extra_fields; j++) {
4325                         fprintf(f, "%sLogExtraFields: ", prefix);
4326                         fwrite(c->log_extra_fields[j].iov_base,
4327                                1, c->log_extra_fields[j].iov_len,
4328                                f);
4329                         fputc('\n', f);
4330                 }
4331         }
4332
4333         if (c->secure_bits) {
4334                 _cleanup_free_ char *str = NULL;
4335
4336                 r = secure_bits_to_string_alloc(c->secure_bits, &str);
4337                 if (r >= 0)
4338                         fprintf(f, "%sSecure Bits: %s\n", prefix, str);
4339         }
4340
4341         if (c->capability_bounding_set != CAP_ALL) {
4342                 _cleanup_free_ char *str = NULL;
4343
4344                 r = capability_set_to_string_alloc(c->capability_bounding_set, &str);
4345                 if (r >= 0)
4346                         fprintf(f, "%sCapabilityBoundingSet: %s\n", prefix, str);
4347         }
4348
4349         if (c->capability_ambient_set != 0) {
4350                 _cleanup_free_ char *str = NULL;
4351
4352                 r = capability_set_to_string_alloc(c->capability_ambient_set, &str);
4353                 if (r >= 0)
4354                         fprintf(f, "%sAmbientCapabilities: %s\n", prefix, str);
4355         }
4356
4357         if (c->user)
4358                 fprintf(f, "%sUser: %s\n", prefix, c->user);
4359         if (c->group)
4360                 fprintf(f, "%sGroup: %s\n", prefix, c->group);
4361
4362         fprintf(f, "%sDynamicUser: %s\n", prefix, yes_no(c->dynamic_user));
4363
4364         if (!strv_isempty(c->supplementary_groups)) {
4365                 fprintf(f, "%sSupplementaryGroups:", prefix);
4366                 strv_fprintf(f, c->supplementary_groups);
4367                 fputs("\n", f);
4368         }
4369
4370         if (c->pam_name)
4371                 fprintf(f, "%sPAMName: %s\n", prefix, c->pam_name);
4372
4373         if (!strv_isempty(c->read_write_paths)) {
4374                 fprintf(f, "%sReadWritePaths:", prefix);
4375                 strv_fprintf(f, c->read_write_paths);
4376                 fputs("\n", f);
4377         }
4378
4379         if (!strv_isempty(c->read_only_paths)) {
4380                 fprintf(f, "%sReadOnlyPaths:", prefix);
4381                 strv_fprintf(f, c->read_only_paths);
4382                 fputs("\n", f);
4383         }
4384
4385         if (!strv_isempty(c->inaccessible_paths)) {
4386                 fprintf(f, "%sInaccessiblePaths:", prefix);
4387                 strv_fprintf(f, c->inaccessible_paths);
4388                 fputs("\n", f);
4389         }
4390
4391         if (c->n_bind_mounts > 0)
4392                 for (i = 0; i < c->n_bind_mounts; i++)
4393                         fprintf(f, "%s%s: %s%s:%s:%s\n", prefix,
4394                                 c->bind_mounts[i].read_only ? "BindReadOnlyPaths" : "BindPaths",
4395                                 c->bind_mounts[i].ignore_enoent ? "-": "",
4396                                 c->bind_mounts[i].source,
4397                                 c->bind_mounts[i].destination,
4398                                 c->bind_mounts[i].recursive ? "rbind" : "norbind");
4399
4400         if (c->n_temporary_filesystems > 0)
4401                 for (i = 0; i < c->n_temporary_filesystems; i++) {
4402                         TemporaryFileSystem *t = c->temporary_filesystems + i;
4403
4404                         fprintf(f, "%sTemporaryFileSystem: %s%s%s\n", prefix,
4405                                 t->path,
4406                                 isempty(t->options) ? "" : ":",
4407                                 strempty(t->options));
4408                 }
4409
4410         if (c->utmp_id)
4411                 fprintf(f,
4412                         "%sUtmpIdentifier: %s\n",
4413                         prefix, c->utmp_id);
4414
4415         if (c->selinux_context)
4416                 fprintf(f,
4417                         "%sSELinuxContext: %s%s\n",
4418                         prefix, c->selinux_context_ignore ? "-" : "", c->selinux_context);
4419
4420         if (c->apparmor_profile)
4421                 fprintf(f,
4422                         "%sAppArmorProfile: %s%s\n",
4423                         prefix, c->apparmor_profile_ignore ? "-" : "", c->apparmor_profile);
4424
4425         if (c->smack_process_label)
4426                 fprintf(f,
4427                         "%sSmackProcessLabel: %s%s\n",
4428                         prefix, c->smack_process_label_ignore ? "-" : "", c->smack_process_label);
4429
4430         if (c->personality != PERSONALITY_INVALID)
4431                 fprintf(f,
4432                         "%sPersonality: %s\n",
4433                         prefix, strna(personality_to_string(c->personality)));
4434
4435         fprintf(f,
4436                 "%sLockPersonality: %s\n",
4437                 prefix, yes_no(c->lock_personality));
4438
4439         if (c->syscall_filter) {
4440 #if HAVE_SECCOMP
4441                 Iterator j;
4442                 void *id, *val;
4443                 bool first = true;
4444 #endif
4445
4446                 fprintf(f,
4447                         "%sSystemCallFilter: ",
4448                         prefix);
4449
4450                 if (!c->syscall_whitelist)
4451                         fputc('~', f);
4452
4453 #if HAVE_SECCOMP
4454                 HASHMAP_FOREACH_KEY(val, id, c->syscall_filter, j) {
4455                         _cleanup_free_ char *name = NULL;
4456                         const char *errno_name = NULL;
4457                         int num = PTR_TO_INT(val);
4458
4459                         if (first)
4460                                 first = false;
4461                         else
4462                                 fputc(' ', f);
4463
4464                         name = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE, PTR_TO_INT(id) - 1);
4465                         fputs(strna(name), f);
4466
4467                         if (num >= 0) {
4468                                 errno_name = errno_to_name(num);
4469                                 if (errno_name)
4470                                         fprintf(f, ":%s", errno_name);
4471                                 else
4472                                         fprintf(f, ":%d", num);
4473                         }
4474                 }
4475 #endif
4476
4477                 fputc('\n', f);
4478         }
4479
4480         if (c->syscall_archs) {
4481 #if HAVE_SECCOMP
4482                 Iterator j;
4483                 void *id;
4484 #endif
4485
4486                 fprintf(f,
4487                         "%sSystemCallArchitectures:",
4488                         prefix);
4489
4490 #if HAVE_SECCOMP
4491                 SET_FOREACH(id, c->syscall_archs, j)
4492                         fprintf(f, " %s", strna(seccomp_arch_to_string(PTR_TO_UINT32(id) - 1)));
4493 #endif
4494                 fputc('\n', f);
4495         }
4496
4497         if (exec_context_restrict_namespaces_set(c)) {
4498                 _cleanup_free_ char *s = NULL;
4499
4500                 r = namespace_flags_to_string(c->restrict_namespaces, &s);
4501                 if (r >= 0)
4502                         fprintf(f, "%sRestrictNamespaces: %s\n",
4503                                 prefix, s);
4504         }
4505
4506         if (c->syscall_errno > 0) {
4507                 const char *errno_name;
4508
4509                 fprintf(f, "%sSystemCallErrorNumber: ", prefix);
4510
4511                 errno_name = errno_to_name(c->syscall_errno);
4512                 if (errno_name)
4513                         fprintf(f, "%s\n", errno_name);
4514                 else
4515                         fprintf(f, "%d\n", c->syscall_errno);
4516         }
4517
4518         if (c->apparmor_profile)
4519                 fprintf(f,
4520                         "%sAppArmorProfile: %s%s\n",
4521                         prefix, c->apparmor_profile_ignore ? "-" : "", c->apparmor_profile);
4522 }
4523
4524 bool exec_context_maintains_privileges(const ExecContext *c) {
4525         assert(c);
4526
4527         /* Returns true if the process forked off would run under
4528          * an unchanged UID or as root. */
4529
4530         if (!c->user)
4531                 return true;
4532
4533         if (streq(c->user, "root") || streq(c->user, "0"))
4534                 return true;
4535
4536         return false;
4537 }
4538
4539 int exec_context_get_effective_ioprio(const ExecContext *c) {
4540         int p;
4541
4542         assert(c);
4543
4544         if (c->ioprio_set)
4545                 return c->ioprio;
4546
4547         p = ioprio_get(IOPRIO_WHO_PROCESS, 0);
4548         if (p < 0)
4549                 return IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 4);
4550
4551         return p;
4552 }
4553
4554 void exec_context_free_log_extra_fields(ExecContext *c) {
4555         size_t l;
4556
4557         assert(c);
4558
4559         for (l = 0; l < c->n_log_extra_fields; l++)
4560                 free(c->log_extra_fields[l].iov_base);
4561         c->log_extra_fields = mfree(c->log_extra_fields);
4562         c->n_log_extra_fields = 0;
4563 }
4564
4565 void exec_status_start(ExecStatus *s, pid_t pid) {
4566         assert(s);
4567
4568         *s = (ExecStatus) {
4569                 .pid = pid,
4570         };
4571
4572         dual_timestamp_get(&s->start_timestamp);
4573 }
4574
4575 void exec_status_exit(ExecStatus *s, const ExecContext *context, pid_t pid, int code, int status) {
4576         assert(s);
4577
4578         if (s->pid != pid) {
4579                 *s = (ExecStatus) {
4580                         .pid = pid,
4581                 };
4582         }
4583
4584         dual_timestamp_get(&s->exit_timestamp);
4585
4586         s->code = code;
4587         s->status = status;
4588
4589         if (context) {
4590                 if (context->utmp_id)
4591                         (void) utmp_put_dead_process(context->utmp_id, pid, code, status);
4592
4593                 exec_context_tty_reset(context, NULL);
4594         }
4595 }
4596
4597 void exec_status_reset(ExecStatus *s) {
4598         assert(s);
4599
4600         *s = (ExecStatus) {};
4601 }
4602
4603 void exec_status_dump(const ExecStatus *s, FILE *f, const char *prefix) {
4604         char buf[FORMAT_TIMESTAMP_MAX];
4605
4606         assert(s);
4607         assert(f);
4608
4609         if (s->pid <= 0)
4610                 return;
4611
4612         prefix = strempty(prefix);
4613
4614         fprintf(f,
4615                 "%sPID: "PID_FMT"\n",
4616                 prefix, s->pid);
4617
4618         if (dual_timestamp_is_set(&s->start_timestamp))
4619                 fprintf(f,
4620                         "%sStart Timestamp: %s\n",
4621                         prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp.realtime));
4622
4623         if (dual_timestamp_is_set(&s->exit_timestamp))
4624                 fprintf(f,
4625                         "%sExit Timestamp: %s\n"
4626                         "%sExit Code: %s\n"
4627                         "%sExit Status: %i\n",
4628                         prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp.realtime),
4629                         prefix, sigchld_code_to_string(s->code),
4630                         prefix, s->status);
4631 }
4632
4633 static char *exec_command_line(char **argv) {
4634         size_t k;
4635         char *n, *p, **a;
4636         bool first = true;
4637
4638         assert(argv);
4639
4640         k = 1;
4641         STRV_FOREACH(a, argv)
4642                 k += strlen(*a)+3;
4643
4644         n = new(char, k);
4645         if (!n)
4646                 return NULL;
4647
4648         p = n;
4649         STRV_FOREACH(a, argv) {
4650
4651                 if (!first)
4652                         *(p++) = ' ';
4653                 else
4654                         first = false;
4655
4656                 if (strpbrk(*a, WHITESPACE)) {
4657                         *(p++) = '\'';
4658                         p = stpcpy(p, *a);
4659                         *(p++) = '\'';
4660                 } else
4661                         p = stpcpy(p, *a);
4662
4663         }
4664
4665         *p = 0;
4666
4667         /* FIXME: this doesn't really handle arguments that have
4668          * spaces and ticks in them */
4669
4670         return n;
4671 }
4672
4673 static void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
4674         _cleanup_free_ char *cmd = NULL;
4675         const char *prefix2;
4676
4677         assert(c);
4678         assert(f);
4679
4680         prefix = strempty(prefix);
4681         prefix2 = strjoina(prefix, "\t");
4682
4683         cmd = exec_command_line(c->argv);
4684         fprintf(f,
4685                 "%sCommand Line: %s\n",
4686                 prefix, cmd ? cmd : strerror(ENOMEM));
4687
4688         exec_status_dump(&c->exec_status, f, prefix2);
4689 }
4690
4691 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
4692         assert(f);
4693
4694         prefix = strempty(prefix);
4695
4696         LIST_FOREACH(command, c, c)
4697                 exec_command_dump(c, f, prefix);
4698 }
4699
4700 void exec_command_append_list(ExecCommand **l, ExecCommand *e) {
4701         ExecCommand *end;
4702
4703         assert(l);
4704         assert(e);
4705
4706         if (*l) {
4707                 /* It's kind of important, that we keep the order here */
4708                 LIST_FIND_TAIL(command, *l, end);
4709                 LIST_INSERT_AFTER(command, *l, end, e);
4710         } else
4711               *l = e;
4712 }
4713
4714 int exec_command_set(ExecCommand *c, const char *path, ...) {
4715         va_list ap;
4716         char **l, *p;
4717
4718         assert(c);
4719         assert(path);
4720
4721         va_start(ap, path);
4722         l = strv_new_ap(path, ap);
4723         va_end(ap);
4724
4725         if (!l)
4726                 return -ENOMEM;
4727
4728         p = strdup(path);
4729         if (!p) {
4730                 strv_free(l);
4731                 return -ENOMEM;
4732         }
4733
4734         free_and_replace(c->path, p);
4735
4736         return strv_free_and_replace(c->argv, l);
4737 }
4738
4739 int exec_command_append(ExecCommand *c, const char *path, ...) {
4740         _cleanup_strv_free_ char **l = NULL;
4741         va_list ap;
4742         int r;
4743
4744         assert(c);
4745         assert(path);
4746
4747         va_start(ap, path);
4748         l = strv_new_ap(path, ap);
4749         va_end(ap);
4750
4751         if (!l)
4752                 return -ENOMEM;
4753
4754         r = strv_extend_strv(&c->argv, l, false);
4755         if (r < 0)
4756                 return r;
4757
4758         return 0;
4759 }
4760
4761 static void *remove_tmpdir_thread(void *p) {
4762         _cleanup_free_ char *path = p;
4763
4764         (void) rm_rf(path, REMOVE_ROOT|REMOVE_PHYSICAL);
4765         return NULL;
4766 }
4767
4768 static ExecRuntime* exec_runtime_free(ExecRuntime *rt, bool destroy) {
4769         int r;
4770
4771         if (!rt)
4772                 return NULL;
4773
4774         if (rt->manager)
4775                 (void) hashmap_remove(rt->manager->exec_runtime_by_id, rt->id);
4776
4777         /* When destroy is true, then rm_rf tmp_dir and var_tmp_dir. */
4778         if (destroy && rt->tmp_dir) {
4779                 log_debug("Spawning thread to nuke %s", rt->tmp_dir);
4780
4781                 r = asynchronous_job(remove_tmpdir_thread, rt->tmp_dir);
4782                 if (r < 0) {
4783                         log_warning_errno(r, "Failed to nuke %s: %m", rt->tmp_dir);
4784                         free(rt->tmp_dir);
4785                 }
4786
4787                 rt->tmp_dir = NULL;
4788         }
4789
4790         if (destroy && rt->var_tmp_dir) {
4791                 log_debug("Spawning thread to nuke %s", rt->var_tmp_dir);
4792
4793                 r = asynchronous_job(remove_tmpdir_thread, rt->var_tmp_dir);
4794                 if (r < 0) {
4795                         log_warning_errno(r, "Failed to nuke %s: %m", rt->var_tmp_dir);
4796                         free(rt->var_tmp_dir);
4797                 }
4798
4799                 rt->var_tmp_dir = NULL;
4800         }
4801
4802         rt->id = mfree(rt->id);
4803         rt->tmp_dir = mfree(rt->tmp_dir);
4804         rt->var_tmp_dir = mfree(rt->var_tmp_dir);
4805         safe_close_pair(rt->netns_storage_socket);
4806         return mfree(rt);
4807 }
4808
4809 static void exec_runtime_freep(ExecRuntime **rt) {
4810         if (*rt)
4811                 (void) exec_runtime_free(*rt, false);
4812 }
4813
4814 static int exec_runtime_allocate(ExecRuntime **rt) {
4815         assert(rt);
4816
4817         *rt = new0(ExecRuntime, 1);
4818         if (!*rt)
4819                 return -ENOMEM;
4820
4821         (*rt)->netns_storage_socket[0] = (*rt)->netns_storage_socket[1] = -1;
4822         return 0;
4823 }
4824
4825 static int exec_runtime_add(
4826                 Manager *m,
4827                 const char *id,
4828                 const char *tmp_dir,
4829                 const char *var_tmp_dir,
4830                 const int netns_storage_socket[2],
4831                 ExecRuntime **ret) {
4832
4833         _cleanup_(exec_runtime_freep) ExecRuntime *rt = NULL;
4834         int r;
4835
4836         assert(m);
4837         assert(id);
4838
4839         r = hashmap_ensure_allocated(&m->exec_runtime_by_id, &string_hash_ops);
4840         if (r < 0)
4841                 return r;
4842
4843         r = exec_runtime_allocate(&rt);
4844         if (r < 0)
4845                 return r;
4846
4847         rt->id = strdup(id);
4848         if (!rt->id)
4849                 return -ENOMEM;
4850
4851         if (tmp_dir) {
4852                 rt->tmp_dir = strdup(tmp_dir);
4853                 if (!rt->tmp_dir)
4854                         return -ENOMEM;
4855
4856                 /* When tmp_dir is set, then we require var_tmp_dir is also set. */
4857                 assert(var_tmp_dir);
4858                 rt->var_tmp_dir = strdup(var_tmp_dir);
4859                 if (!rt->var_tmp_dir)
4860                         return -ENOMEM;
4861         }
4862
4863         if (netns_storage_socket) {
4864                 rt->netns_storage_socket[0] = netns_storage_socket[0];
4865                 rt->netns_storage_socket[1] = netns_storage_socket[1];
4866         }
4867
4868         r = hashmap_put(m->exec_runtime_by_id, rt->id, rt);
4869         if (r < 0)
4870                 return r;
4871
4872         rt->manager = m;
4873
4874         if (ret)
4875                 *ret = rt;
4876
4877         /* do not remove created ExecRuntime object when the operation succeeds. */
4878         rt = NULL;
4879         return 0;
4880 }
4881
4882 static int exec_runtime_make(Manager *m, const ExecContext *c, const char *id, ExecRuntime **ret) {
4883         _cleanup_free_ char *tmp_dir = NULL, *var_tmp_dir = NULL;
4884         _cleanup_close_pair_ int netns_storage_socket[2] = {-1, -1};
4885         int r;
4886
4887         assert(m);
4888         assert(c);
4889         assert(id);
4890
4891         /* It is not necessary to create ExecRuntime object. */
4892         if (!c->private_network && !c->private_tmp)
4893                 return 0;
4894
4895         if (c->private_tmp) {
4896                 r = setup_tmp_dirs(id, &tmp_dir, &var_tmp_dir);
4897                 if (r < 0)
4898                         return r;
4899         }
4900
4901         if (c->private_network) {
4902                 if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, netns_storage_socket) < 0)
4903                         return -errno;
4904         }
4905
4906         r = exec_runtime_add(m, id, tmp_dir, var_tmp_dir, netns_storage_socket, ret);
4907         if (r < 0)
4908                 return r;
4909
4910         /* Avoid cleanup */
4911         netns_storage_socket[0] = -1;
4912         netns_storage_socket[1] = -1;
4913         return 1;
4914 }
4915
4916 int exec_runtime_acquire(Manager *m, const ExecContext *c, const char *id, bool create, ExecRuntime **ret) {
4917         ExecRuntime *rt;
4918         int r;
4919
4920         assert(m);
4921         assert(id);
4922         assert(ret);
4923
4924         rt = hashmap_get(m->exec_runtime_by_id, id);
4925         if (rt)
4926                 /* We already have a ExecRuntime object, let's increase the ref count and reuse it */
4927                 goto ref;
4928
4929         if (!create)
4930                 return 0;
4931
4932         /* If not found, then create a new object. */
4933         r = exec_runtime_make(m, c, id, &rt);
4934         if (r <= 0)
4935                 /* When r == 0, it is not necessary to create ExecRuntime object. */
4936                 return r;
4937
4938 ref:
4939         /* increment reference counter. */
4940         rt->n_ref++;
4941         *ret = rt;
4942         return 1;
4943 }
4944
4945 ExecRuntime *exec_runtime_unref(ExecRuntime *rt, bool destroy) {
4946         if (!rt)
4947                 return NULL;
4948
4949         assert(rt->n_ref > 0);
4950
4951         rt->n_ref--;
4952         if (rt->n_ref > 0)
4953                 return NULL;
4954
4955         return exec_runtime_free(rt, destroy);
4956 }
4957
4958 int exec_runtime_serialize(const Manager *m, FILE *f, FDSet *fds) {
4959         ExecRuntime *rt;
4960         Iterator i;
4961
4962         assert(m);
4963         assert(f);
4964         assert(fds);
4965
4966         HASHMAP_FOREACH(rt, m->exec_runtime_by_id, i) {
4967                 fprintf(f, "exec-runtime=%s", rt->id);
4968
4969                 if (rt->tmp_dir)
4970                         fprintf(f, " tmp-dir=%s", rt->tmp_dir);
4971
4972                 if (rt->var_tmp_dir)
4973                         fprintf(f, " var-tmp-dir=%s", rt->var_tmp_dir);
4974
4975                 if (rt->netns_storage_socket[0] >= 0) {
4976                         int copy;
4977
4978                         copy = fdset_put_dup(fds, rt->netns_storage_socket[0]);
4979                         if (copy < 0)
4980                                 return copy;
4981
4982                         fprintf(f, " netns-socket-0=%i", copy);
4983                 }
4984
4985                 if (rt->netns_storage_socket[1] >= 0) {
4986                         int copy;
4987
4988                         copy = fdset_put_dup(fds, rt->netns_storage_socket[1]);
4989                         if (copy < 0)
4990                                 return copy;
4991
4992                         fprintf(f, " netns-socket-1=%i", copy);
4993                 }
4994
4995                 fputc('\n', f);
4996         }
4997
4998         return 0;
4999 }
5000
5001 int exec_runtime_deserialize_compat(Unit *u, const char *key, const char *value, FDSet *fds) {
5002         _cleanup_(exec_runtime_freep) ExecRuntime *rt_create = NULL;
5003         ExecRuntime *rt;
5004         int r;
5005
5006         /* This is for the migration from old (v237 or earlier) deserialization text.
5007          * Due to the bug #7790, this may not work with the units that use JoinsNamespaceOf=.
5008          * Even if the ExecRuntime object originally created by the other unit, we cannot judge
5009          * so or not from the serialized text, then we always creates a new object owned by this. */
5010
5011         assert(u);
5012         assert(key);
5013         assert(value);
5014
5015         /* Manager manages ExecRuntime objects by the unit id.
5016          * So, we omit the serialized text when the unit does not have id (yet?)... */
5017         if (isempty(u->id)) {
5018                 log_unit_debug(u, "Invocation ID not found. Dropping runtime parameter.");
5019                 return 0;
5020         }
5021
5022         r = hashmap_ensure_allocated(&u->manager->exec_runtime_by_id, &string_hash_ops);
5023         if (r < 0) {
5024                 log_unit_debug_errno(u, r, "Failed to allocate storage for runtime parameter: %m");
5025                 return 0;
5026         }
5027
5028         rt = hashmap_get(u->manager->exec_runtime_by_id, u->id);
5029         if (!rt) {
5030                 r = exec_runtime_allocate(&rt_create);
5031                 if (r < 0)
5032                         return log_oom();
5033
5034                 rt_create->id = strdup(u->id);
5035                 if (!rt_create->id)
5036                         return log_oom();
5037
5038                 rt = rt_create;
5039         }
5040
5041         if (streq(key, "tmp-dir")) {
5042                 char *copy;
5043
5044                 copy = strdup(value);
5045                 if (!copy)
5046                         return log_oom();
5047
5048                 free_and_replace(rt->tmp_dir, copy);
5049
5050         } else if (streq(key, "var-tmp-dir")) {
5051                 char *copy;
5052
5053                 copy = strdup(value);
5054                 if (!copy)
5055                         return log_oom();
5056
5057                 free_and_replace(rt->var_tmp_dir, copy);
5058
5059         } else if (streq(key, "netns-socket-0")) {
5060                 int fd;
5061
5062                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd)) {
5063                         log_unit_debug(u, "Failed to parse netns socket value: %s", value);
5064                         return 0;
5065                 }
5066
5067                 safe_close(rt->netns_storage_socket[0]);
5068                 rt->netns_storage_socket[0] = fdset_remove(fds, fd);
5069
5070         } else if (streq(key, "netns-socket-1")) {
5071                 int fd;
5072
5073                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd)) {
5074                         log_unit_debug(u, "Failed to parse netns socket value: %s", value);
5075                         return 0;
5076                 }
5077
5078                 safe_close(rt->netns_storage_socket[1]);
5079                 rt->netns_storage_socket[1] = fdset_remove(fds, fd);
5080         } else
5081                 return 0;
5082
5083         /* If the object is newly created, then put it to the hashmap which manages ExecRuntime objects. */
5084         if (rt_create) {
5085                 r = hashmap_put(u->manager->exec_runtime_by_id, rt_create->id, rt_create);
5086                 if (r < 0) {
5087                         log_unit_debug_errno(u, r, "Failed to put runtime parameter to manager's storage: %m");
5088                         return 0;
5089                 }
5090
5091                 rt_create->manager = u->manager;
5092
5093                 /* Avoid cleanup */
5094                 rt_create = NULL;
5095         }
5096
5097         return 1;
5098 }
5099
5100 void exec_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds) {
5101         char *id = NULL, *tmp_dir = NULL, *var_tmp_dir = NULL;
5102         int r, fd0 = -1, fd1 = -1;
5103         const char *p, *v = value;
5104         size_t n;
5105
5106         assert(m);
5107         assert(value);
5108         assert(fds);
5109
5110         n = strcspn(v, " ");
5111         id = strndupa(v, n);
5112         if (v[n] != ' ')
5113                 goto finalize;
5114         p = v + n + 1;
5115
5116         v = startswith(p, "tmp-dir=");
5117         if (v) {
5118                 n = strcspn(v, " ");
5119                 tmp_dir = strndupa(v, n);
5120                 if (v[n] != ' ')
5121                         goto finalize;
5122                 p = v + n + 1;
5123         }
5124
5125         v = startswith(p, "var-tmp-dir=");
5126         if (v) {
5127                 n = strcspn(v, " ");
5128                 var_tmp_dir = strndupa(v, n);
5129                 if (v[n] != ' ')
5130                         goto finalize;
5131                 p = v + n + 1;
5132         }
5133
5134         v = startswith(p, "netns-socket-0=");
5135         if (v) {
5136                 char *buf;
5137
5138                 n = strcspn(v, " ");
5139                 buf = strndupa(v, n);
5140                 if (safe_atoi(buf, &fd0) < 0 || !fdset_contains(fds, fd0)) {
5141                         log_debug("Unable to process exec-runtime netns fd specification.");
5142                         return;
5143                 }
5144                 fd0 = fdset_remove(fds, fd0);
5145                 if (v[n] != ' ')
5146                         goto finalize;
5147                 p = v + n + 1;
5148         }
5149
5150         v = startswith(p, "netns-socket-1=");
5151         if (v) {
5152                 char *buf;
5153
5154                 n = strcspn(v, " ");
5155                 buf = strndupa(v, n);
5156                 if (safe_atoi(buf, &fd1) < 0 || !fdset_contains(fds, fd1)) {
5157                         log_debug("Unable to process exec-runtime netns fd specification.");
5158                         return;
5159                 }
5160                 fd1 = fdset_remove(fds, fd1);
5161         }
5162
5163 finalize:
5164
5165         r = exec_runtime_add(m, id, tmp_dir, var_tmp_dir, (int[]) { fd0, fd1 }, NULL);
5166         if (r < 0)
5167                 log_debug_errno(r, "Failed to add exec-runtime: %m");
5168 }
5169
5170 void exec_runtime_vacuum(Manager *m) {
5171         ExecRuntime *rt;
5172         Iterator i;
5173
5174         assert(m);
5175
5176         /* Free unreferenced ExecRuntime objects. This is used after manager deserialization process. */
5177
5178         HASHMAP_FOREACH(rt, m->exec_runtime_by_id, i) {
5179                 if (rt->n_ref > 0)
5180                         continue;
5181
5182                 (void) exec_runtime_free(rt, false);
5183         }
5184 }
5185
5186 void exec_params_clear(ExecParameters *p) {
5187         if (!p)
5188                 return;
5189
5190         strv_free(p->environment);
5191 }
5192
5193 static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
5194         [EXEC_INPUT_NULL] = "null",
5195         [EXEC_INPUT_TTY] = "tty",
5196         [EXEC_INPUT_TTY_FORCE] = "tty-force",
5197         [EXEC_INPUT_TTY_FAIL] = "tty-fail",
5198         [EXEC_INPUT_SOCKET] = "socket",
5199         [EXEC_INPUT_NAMED_FD] = "fd",
5200         [EXEC_INPUT_DATA] = "data",
5201         [EXEC_INPUT_FILE] = "file",
5202 };
5203
5204 DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);
5205
5206 static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
5207         [EXEC_OUTPUT_INHERIT] = "inherit",
5208         [EXEC_OUTPUT_NULL] = "null",
5209         [EXEC_OUTPUT_TTY] = "tty",
5210         [EXEC_OUTPUT_SYSLOG] = "syslog",
5211         [EXEC_OUTPUT_SYSLOG_AND_CONSOLE] = "syslog+console",
5212         [EXEC_OUTPUT_KMSG] = "kmsg",
5213         [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
5214         [EXEC_OUTPUT_JOURNAL] = "journal",
5215         [EXEC_OUTPUT_JOURNAL_AND_CONSOLE] = "journal+console",
5216         [EXEC_OUTPUT_SOCKET] = "socket",
5217         [EXEC_OUTPUT_NAMED_FD] = "fd",
5218         [EXEC_OUTPUT_FILE] = "file",
5219         [EXEC_OUTPUT_FILE_APPEND] = "append",
5220 };
5221
5222 DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);
5223
5224 static const char* const exec_utmp_mode_table[_EXEC_UTMP_MODE_MAX] = {
5225         [EXEC_UTMP_INIT] = "init",
5226         [EXEC_UTMP_LOGIN] = "login",
5227         [EXEC_UTMP_USER] = "user",
5228 };
5229
5230 DEFINE_STRING_TABLE_LOOKUP(exec_utmp_mode, ExecUtmpMode);
5231
5232 static const char* const exec_preserve_mode_table[_EXEC_PRESERVE_MODE_MAX] = {
5233         [EXEC_PRESERVE_NO] = "no",
5234         [EXEC_PRESERVE_YES] = "yes",
5235         [EXEC_PRESERVE_RESTART] = "restart",
5236 };
5237
5238 DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(exec_preserve_mode, ExecPreserveMode, EXEC_PRESERVE_YES);
5239
5240 static const char* const exec_directory_type_table[_EXEC_DIRECTORY_TYPE_MAX] = {
5241         [EXEC_DIRECTORY_RUNTIME] = "RuntimeDirectory",
5242         [EXEC_DIRECTORY_STATE] = "StateDirectory",
5243         [EXEC_DIRECTORY_CACHE] = "CacheDirectory",
5244         [EXEC_DIRECTORY_LOGS] = "LogsDirectory",
5245         [EXEC_DIRECTORY_CONFIGURATION] = "ConfigurationDirectory",
5246 };
5247
5248 DEFINE_STRING_TABLE_LOOKUP(exec_directory_type, ExecDirectoryType);
5249
5250 static const char* const exec_directory_env_name_table[_EXEC_DIRECTORY_TYPE_MAX] = {
5251         [EXEC_DIRECTORY_RUNTIME] = "RUNTIME_DIRECTORY",
5252         [EXEC_DIRECTORY_STATE] = "STATE_DIRECTORY",
5253         [EXEC_DIRECTORY_CACHE] = "CACHE_DIRECTORY",
5254         [EXEC_DIRECTORY_LOGS] = "LOGS_DIRECTORY",
5255         [EXEC_DIRECTORY_CONFIGURATION] = "CONFIGURATION_DIRECTORY",
5256 };
5257
5258 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(exec_directory_env_name, ExecDirectoryType);
5259
5260 static const char* const exec_keyring_mode_table[_EXEC_KEYRING_MODE_MAX] = {
5261         [EXEC_KEYRING_INHERIT] = "inherit",
5262         [EXEC_KEYRING_PRIVATE] = "private",
5263         [EXEC_KEYRING_SHARED] = "shared",
5264 };
5265
5266 DEFINE_STRING_TABLE_LOOKUP(exec_keyring_mode, ExecKeyringMode);