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 "memory-util.h"
  69 #include "missing.h"
  70 #include "mkdir.h"
  71 #include "namespace.h"
  72 #include "parse-util.h"
  73 #include "path-util.h"
  74 #include "process-util.h"
  75 #include "rlimit-util.h"
  76 #include "rm-rf.h"
  77 #if HAVE_SECCOMP
  78 #include "seccomp-util.h"
  79 #endif
  80 #include "securebits-util.h"
  81 #include "selinux-util.h"
  82 #include "signal-util.h"
  83 #include "smack-util.h"
  84 #include "socket-util.h"
  85 #include "special.h"
  86 #include "stat-util.h"
  87 #include "string-table.h"
  88 #include "string-util.h"
  89 #include "strv.h"
  90 #include "syslog-util.h"
  91 #include "terminal-util.h"
  92 #include "umask-util.h"
  93 #include "unit.h"
  94 #include "user-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                 c->restrict_suid_sgid ||
1408                 exec_context_restrict_namespaces_set(c) ||
1409                 c->protect_kernel_tunables ||
1410                 c->protect_kernel_modules ||
1411                 c->private_devices ||
1412                 context_has_syscall_filters(c) ||
1413                 !set_isempty(c->syscall_archs) ||
1414                 c->lock_personality ||
1415                 c->protect_hostname;
1416 }
1417
1418 #if HAVE_SECCOMP
1419
1420 static bool skip_seccomp_unavailable(const Unit* u, const char* msg) {
1421
1422         if (is_seccomp_available())
1423                 return false;
1424
1425         log_unit_debug(u, "SECCOMP features not detected in the kernel, skipping %s", msg);
1426         return true;
1427 }
1428
1429 static int apply_syscall_filter(const Unit* u, const ExecContext *c, bool needs_ambient_hack) {
1430         uint32_t negative_action, default_action, action;
1431         int r;
1432
1433         assert(u);
1434         assert(c);
1435
1436         if (!context_has_syscall_filters(c))
1437                 return 0;
1438
1439         if (skip_seccomp_unavailable(u, "SystemCallFilter="))
1440                 return 0;
1441
1442         negative_action = c->syscall_errno == 0 ? SCMP_ACT_KILL : SCMP_ACT_ERRNO(c->syscall_errno);
1443
1444         if (c->syscall_whitelist) {
1445                 default_action = negative_action;
1446                 action = SCMP_ACT_ALLOW;
1447         } else {
1448                 default_action = SCMP_ACT_ALLOW;
1449                 action = negative_action;
1450         }
1451
1452         if (needs_ambient_hack) {
1453                 r = seccomp_filter_set_add(c->syscall_filter, c->syscall_whitelist, syscall_filter_sets + SYSCALL_FILTER_SET_SETUID);
1454                 if (r < 0)
1455                         return r;
1456         }
1457
1458         return seccomp_load_syscall_filter_set_raw(default_action, c->syscall_filter, action, false);
1459 }
1460
1461 static int apply_syscall_archs(const Unit *u, const ExecContext *c) {
1462         assert(u);
1463         assert(c);
1464
1465         if (set_isempty(c->syscall_archs))
1466                 return 0;
1467
1468         if (skip_seccomp_unavailable(u, "SystemCallArchitectures="))
1469                 return 0;
1470
1471         return seccomp_restrict_archs(c->syscall_archs);
1472 }
1473
1474 static int apply_address_families(const Unit* u, const ExecContext *c) {
1475         assert(u);
1476         assert(c);
1477
1478         if (!context_has_address_families(c))
1479                 return 0;
1480
1481         if (skip_seccomp_unavailable(u, "RestrictAddressFamilies="))
1482                 return 0;
1483
1484         return seccomp_restrict_address_families(c->address_families, c->address_families_whitelist);
1485 }
1486
1487 static int apply_memory_deny_write_execute(const Unit* u, const ExecContext *c) {
1488         assert(u);
1489         assert(c);
1490
1491         if (!c->memory_deny_write_execute)
1492                 return 0;
1493
1494         if (skip_seccomp_unavailable(u, "MemoryDenyWriteExecute="))
1495                 return 0;
1496
1497         return seccomp_memory_deny_write_execute();
1498 }
1499
1500 static int apply_restrict_realtime(const Unit* u, const ExecContext *c) {
1501         assert(u);
1502         assert(c);
1503
1504         if (!c->restrict_realtime)
1505                 return 0;
1506
1507         if (skip_seccomp_unavailable(u, "RestrictRealtime="))
1508                 return 0;
1509
1510         return seccomp_restrict_realtime();
1511 }
1512
1513 static int apply_restrict_suid_sgid(const Unit* u, const ExecContext *c) {
1514         assert(u);
1515         assert(c);
1516
1517         if (!c->restrict_suid_sgid)
1518                 return 0;
1519
1520         if (skip_seccomp_unavailable(u, "RestrictSUIDSGID="))
1521                 return 0;
1522
1523         return seccomp_restrict_suid_sgid();
1524 }
1525
1526 static int apply_protect_sysctl(const Unit *u, const ExecContext *c) {
1527         assert(u);
1528         assert(c);
1529
1530         /* Turn off the legacy sysctl() system call. Many distributions turn this off while building the kernel, but
1531          * let's protect even those systems where this is left on in the kernel. */
1532
1533         if (!c->protect_kernel_tunables)
1534                 return 0;
1535
1536         if (skip_seccomp_unavailable(u, "ProtectKernelTunables="))
1537                 return 0;
1538
1539         return seccomp_protect_sysctl();
1540 }
1541
1542 static int apply_protect_kernel_modules(const Unit *u, const ExecContext *c) {
1543         assert(u);
1544         assert(c);
1545
1546         /* Turn off module syscalls on ProtectKernelModules=yes */
1547
1548         if (!c->protect_kernel_modules)
1549                 return 0;
1550
1551         if (skip_seccomp_unavailable(u, "ProtectKernelModules="))
1552                 return 0;
1553
1554         return seccomp_load_syscall_filter_set(SCMP_ACT_ALLOW, syscall_filter_sets + SYSCALL_FILTER_SET_MODULE, SCMP_ACT_ERRNO(EPERM), false);
1555 }
1556
1557 static int apply_private_devices(const Unit *u, const ExecContext *c) {
1558         assert(u);
1559         assert(c);
1560
1561         /* If PrivateDevices= is set, also turn off iopl and all @raw-io syscalls. */
1562
1563         if (!c->private_devices)
1564                 return 0;
1565
1566         if (skip_seccomp_unavailable(u, "PrivateDevices="))
1567                 return 0;
1568
1569         return seccomp_load_syscall_filter_set(SCMP_ACT_ALLOW, syscall_filter_sets + SYSCALL_FILTER_SET_RAW_IO, SCMP_ACT_ERRNO(EPERM), false);
1570 }
1571
1572 static int apply_restrict_namespaces(const Unit *u, const ExecContext *c) {
1573         assert(u);
1574         assert(c);
1575
1576         if (!exec_context_restrict_namespaces_set(c))
1577                 return 0;
1578
1579         if (skip_seccomp_unavailable(u, "RestrictNamespaces="))
1580                 return 0;
1581
1582         return seccomp_restrict_namespaces(c->restrict_namespaces);
1583 }
1584
1585 static int apply_lock_personality(const Unit* u, const ExecContext *c) {
1586         unsigned long personality;
1587         int r;
1588
1589         assert(u);
1590         assert(c);
1591
1592         if (!c->lock_personality)
1593                 return 0;
1594
1595         if (skip_seccomp_unavailable(u, "LockPersonality="))
1596                 return 0;
1597
1598         personality = c->personality;
1599
1600         /* If personality is not specified, use either PER_LINUX or PER_LINUX32 depending on what is currently set. */
1601         if (personality == PERSONALITY_INVALID) {
1602
1603                 r = opinionated_personality(&personality);
1604                 if (r < 0)
1605                         return r;
1606         }
1607
1608         return seccomp_lock_personality(personality);
1609 }
1610
1611 #endif
1612
1613 static void do_idle_pipe_dance(int idle_pipe[static 4]) {
1614         assert(idle_pipe);
1615
1616         idle_pipe[1] = safe_close(idle_pipe[1]);
1617         idle_pipe[2] = safe_close(idle_pipe[2]);
1618
1619         if (idle_pipe[0] >= 0) {
1620                 int r;
1621
1622                 r = fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT_USEC);
1623
1624                 if (idle_pipe[3] >= 0 && r == 0 /* timeout */) {
1625                         ssize_t n;
1626
1627                         /* Signal systemd that we are bored and want to continue. */
1628                         n = write(idle_pipe[3], "x", 1);
1629                         if (n > 0)
1630                                 /* Wait for systemd to react to the signal above. */
1631                                 fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT2_USEC);
1632                 }
1633
1634                 idle_pipe[0] = safe_close(idle_pipe[0]);
1635
1636         }
1637
1638         idle_pipe[3] = safe_close(idle_pipe[3]);
1639 }
1640
1641 static const char *exec_directory_env_name_to_string(ExecDirectoryType t);
1642
1643 static int build_environment(
1644                 const Unit *u,
1645                 const ExecContext *c,
1646                 const ExecParameters *p,
1647                 size_t n_fds,
1648                 const char *home,
1649                 const char *username,
1650                 const char *shell,
1651                 dev_t journal_stream_dev,
1652                 ino_t journal_stream_ino,
1653                 char ***ret) {
1654
1655         _cleanup_strv_free_ char **our_env = NULL;
1656         ExecDirectoryType t;
1657         size_t n_env = 0;
1658         char *x;
1659
1660         assert(u);
1661         assert(c);
1662         assert(p);
1663         assert(ret);
1664
1665         our_env = new0(char*, 14 + _EXEC_DIRECTORY_TYPE_MAX);
1666         if (!our_env)
1667                 return -ENOMEM;
1668
1669         if (n_fds > 0) {
1670                 _cleanup_free_ char *joined = NULL;
1671
1672                 if (asprintf(&x, "LISTEN_PID="PID_FMT, getpid_cached()) < 0)
1673                         return -ENOMEM;
1674                 our_env[n_env++] = x;
1675
1676                 if (asprintf(&x, "LISTEN_FDS=%zu", n_fds) < 0)
1677                         return -ENOMEM;
1678                 our_env[n_env++] = x;
1679
1680                 joined = strv_join(p->fd_names, ":");
1681                 if (!joined)
1682                         return -ENOMEM;
1683
1684                 x = strjoin("LISTEN_FDNAMES=", joined);
1685                 if (!x)
1686                         return -ENOMEM;
1687                 our_env[n_env++] = x;
1688         }
1689
1690         if ((p->flags & EXEC_SET_WATCHDOG) && p->watchdog_usec > 0) {
1691                 if (asprintf(&x, "WATCHDOG_PID="PID_FMT, getpid_cached()) < 0)
1692                         return -ENOMEM;
1693                 our_env[n_env++] = x;
1694
1695                 if (asprintf(&x, "WATCHDOG_USEC="USEC_FMT, p->watchdog_usec) < 0)
1696                         return -ENOMEM;
1697                 our_env[n_env++] = x;
1698         }
1699
1700         /* If this is D-Bus, tell the nss-systemd module, since it relies on being able to use D-Bus look up dynamic
1701          * users via PID 1, possibly dead-locking the dbus daemon. This way it will not use D-Bus to resolve names, but
1702          * check the database directly. */
1703         if (p->flags & EXEC_NSS_BYPASS_BUS) {
1704                 x = strdup("SYSTEMD_NSS_BYPASS_BUS=1");
1705                 if (!x)
1706                         return -ENOMEM;
1707                 our_env[n_env++] = x;
1708         }
1709
1710         if (home) {
1711                 x = strappend("HOME=", home);
1712                 if (!x)
1713                         return -ENOMEM;
1714
1715                 path_simplify(x + 5, true);
1716                 our_env[n_env++] = x;
1717         }
1718
1719         if (username) {
1720                 x = strappend("LOGNAME=", username);
1721                 if (!x)
1722                         return -ENOMEM;
1723                 our_env[n_env++] = x;
1724
1725                 x = strappend("USER=", username);
1726                 if (!x)
1727                         return -ENOMEM;
1728                 our_env[n_env++] = x;
1729         }
1730
1731         if (shell) {
1732                 x = strappend("SHELL=", shell);
1733                 if (!x)
1734                         return -ENOMEM;
1735
1736                 path_simplify(x + 6, true);
1737                 our_env[n_env++] = x;
1738         }
1739
1740         if (!sd_id128_is_null(u->invocation_id)) {
1741                 if (asprintf(&x, "INVOCATION_ID=" SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(u->invocation_id)) < 0)
1742                         return -ENOMEM;
1743
1744                 our_env[n_env++] = x;
1745         }
1746
1747         if (exec_context_needs_term(c)) {
1748                 const char *tty_path, *term = NULL;
1749
1750                 tty_path = exec_context_tty_path(c);
1751
1752                 /* If we are forked off PID 1 and we are supposed to operate on /dev/console, then let's try to inherit
1753                  * the $TERM set for PID 1. This is useful for containers so that the $TERM the container manager
1754                  * passes to PID 1 ends up all the way in the console login shown. */
1755
1756                 if (path_equal(tty_path, "/dev/console") && getppid() == 1)
1757                         term = getenv("TERM");
1758                 if (!term)
1759                         term = default_term_for_tty(tty_path);
1760
1761                 x = strappend("TERM=", term);
1762                 if (!x)
1763                         return -ENOMEM;
1764                 our_env[n_env++] = x;
1765         }
1766
1767         if (journal_stream_dev != 0 && journal_stream_ino != 0) {
1768                 if (asprintf(&x, "JOURNAL_STREAM=" DEV_FMT ":" INO_FMT, journal_stream_dev, journal_stream_ino) < 0)
1769                         return -ENOMEM;
1770
1771                 our_env[n_env++] = x;
1772         }
1773
1774         for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
1775                 _cleanup_free_ char *pre = NULL, *joined = NULL;
1776                 const char *n;
1777
1778                 if (!p->prefix[t])
1779                         continue;
1780
1781                 if (strv_isempty(c->directories[t].paths))
1782                         continue;
1783
1784                 n = exec_directory_env_name_to_string(t);
1785                 if (!n)
1786                         continue;
1787
1788                 pre = strjoin(p->prefix[t], "/");
1789                 if (!pre)
1790                         return -ENOMEM;
1791
1792                 joined = strv_join_prefix(c->directories[t].paths, ":", pre);
1793                 if (!joined)
1794                         return -ENOMEM;
1795
1796                 x = strjoin(n, "=", joined);
1797                 if (!x)
1798                         return -ENOMEM;
1799
1800                 our_env[n_env++] = x;
1801         }
1802
1803         our_env[n_env++] = NULL;
1804         assert(n_env <= 14 + _EXEC_DIRECTORY_TYPE_MAX);
1805
1806         *ret = TAKE_PTR(our_env);
1807
1808         return 0;
1809 }
1810
1811 static int build_pass_environment(const ExecContext *c, char ***ret) {
1812         _cleanup_strv_free_ char **pass_env = NULL;
1813         size_t n_env = 0, n_bufsize = 0;
1814         char **i;
1815
1816         STRV_FOREACH(i, c->pass_environment) {
1817                 _cleanup_free_ char *x = NULL;
1818                 char *v;
1819
1820                 v = getenv(*i);
1821                 if (!v)
1822                         continue;
1823                 x = strjoin(*i, "=", v);
1824                 if (!x)
1825                         return -ENOMEM;
1826
1827                 if (!GREEDY_REALLOC(pass_env, n_bufsize, n_env + 2))
1828                         return -ENOMEM;
1829
1830                 pass_env[n_env++] = TAKE_PTR(x);
1831                 pass_env[n_env] = NULL;
1832         }
1833
1834         *ret = TAKE_PTR(pass_env);
1835
1836         return 0;
1837 }
1838
1839 static bool exec_needs_mount_namespace(
1840                 const ExecContext *context,
1841                 const ExecParameters *params,
1842                 const ExecRuntime *runtime) {
1843
1844         assert(context);
1845         assert(params);
1846
1847         if (context->root_image)
1848                 return true;
1849
1850         if (!strv_isempty(context->read_write_paths) ||
1851             !strv_isempty(context->read_only_paths) ||
1852             !strv_isempty(context->inaccessible_paths))
1853                 return true;
1854
1855         if (context->n_bind_mounts > 0)
1856                 return true;
1857
1858         if (context->n_temporary_filesystems > 0)
1859                 return true;
1860
1861         if (!IN_SET(context->mount_flags, 0, MS_SHARED))
1862                 return true;
1863
1864         if (context->private_tmp && runtime && (runtime->tmp_dir || runtime->var_tmp_dir))
1865                 return true;
1866
1867         if (context->private_devices ||
1868             context->private_mounts ||
1869             context->protect_system != PROTECT_SYSTEM_NO ||
1870             context->protect_home != PROTECT_HOME_NO ||
1871             context->protect_kernel_tunables ||
1872             context->protect_kernel_modules ||
1873             context->protect_control_groups)
1874                 return true;
1875
1876         if (context->root_directory) {
1877                 ExecDirectoryType t;
1878
1879                 if (context->mount_apivfs)
1880                         return true;
1881
1882                 for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
1883                         if (!params->prefix[t])
1884                                 continue;
1885
1886                         if (!strv_isempty(context->directories[t].paths))
1887                                 return true;
1888                 }
1889         }
1890
1891         if (context->dynamic_user &&
1892             (!strv_isempty(context->directories[EXEC_DIRECTORY_STATE].paths) ||
1893              !strv_isempty(context->directories[EXEC_DIRECTORY_CACHE].paths) ||
1894              !strv_isempty(context->directories[EXEC_DIRECTORY_LOGS].paths)))
1895                 return true;
1896
1897         return false;
1898 }
1899
1900 static int setup_private_users(uid_t uid, gid_t gid) {
1901         _cleanup_free_ char *uid_map = NULL, *gid_map = NULL;
1902         _cleanup_close_pair_ int errno_pipe[2] = { -1, -1 };
1903         _cleanup_close_ int unshare_ready_fd = -1;
1904         _cleanup_(sigkill_waitp) pid_t pid = 0;
1905         uint64_t c = 1;
1906         ssize_t n;
1907         int r;
1908
1909         /* Set up a user namespace and map root to root, the selected UID/GID to itself, and everything else to
1910          * nobody. In order to be able to write this mapping we need CAP_SETUID in the original user namespace, which
1911          * we however lack after opening the user namespace. To work around this we fork() a temporary child process,
1912          * which waits for the parent to create the new user namespace while staying in the original namespace. The
1913          * child then writes the UID mapping, under full privileges. The parent waits for the child to finish and
1914          * continues execution normally. */
1915
1916         if (uid != 0 && uid_is_valid(uid)) {
1917                 r = asprintf(&uid_map,
1918                              "0 0 1\n"                      /* Map root → root */
1919                              UID_FMT " " UID_FMT " 1\n",    /* Map $UID → $UID */
1920                              uid, uid);
1921                 if (r < 0)
1922                         return -ENOMEM;
1923         } else {
1924                 uid_map = strdup("0 0 1\n");            /* The case where the above is the same */
1925                 if (!uid_map)
1926                         return -ENOMEM;
1927         }
1928
1929         if (gid != 0 && gid_is_valid(gid)) {
1930                 r = asprintf(&gid_map,
1931                              "0 0 1\n"                      /* Map root → root */
1932                              GID_FMT " " GID_FMT " 1\n",    /* Map $GID → $GID */
1933                              gid, gid);
1934                 if (r < 0)
1935                         return -ENOMEM;
1936         } else {
1937                 gid_map = strdup("0 0 1\n");            /* The case where the above is the same */
1938                 if (!gid_map)
1939                         return -ENOMEM;
1940         }
1941
1942         /* Create a communication channel so that the parent can tell the child when it finished creating the user
1943          * namespace. */
1944         unshare_ready_fd = eventfd(0, EFD_CLOEXEC);
1945         if (unshare_ready_fd < 0)
1946                 return -errno;
1947
1948         /* Create a communication channel so that the child can tell the parent a proper error code in case it
1949          * failed. */
1950         if (pipe2(errno_pipe, O_CLOEXEC) < 0)
1951                 return -errno;
1952
1953         r = safe_fork("(sd-userns)", FORK_RESET_SIGNALS|FORK_DEATHSIG, &pid);
1954         if (r < 0)
1955                 return r;
1956         if (r == 0) {
1957                 _cleanup_close_ int fd = -1;
1958                 const char *a;
1959                 pid_t ppid;
1960
1961                 /* Child process, running in the original user namespace. Let's update the parent's UID/GID map from
1962                  * here, after the parent opened its own user namespace. */
1963
1964                 ppid = getppid();
1965                 errno_pipe[0] = safe_close(errno_pipe[0]);
1966
1967                 /* Wait until the parent unshared the user namespace */
1968                 if (read(unshare_ready_fd, &c, sizeof(c)) < 0) {
1969                         r = -errno;
1970                         goto child_fail;
1971                 }
1972
1973                 /* Disable the setgroups() system call in the child user namespace, for good. */
1974                 a = procfs_file_alloca(ppid, "setgroups");
1975                 fd = open(a, O_WRONLY|O_CLOEXEC);
1976                 if (fd < 0) {
1977                         if (errno != ENOENT) {
1978                                 r = -errno;
1979                                 goto child_fail;
1980                         }
1981
1982                         /* If the file is missing the kernel is too old, let's continue anyway. */
1983                 } else {
1984                         if (write(fd, "deny\n", 5) < 0) {
1985                                 r = -errno;
1986                                 goto child_fail;
1987                         }
1988
1989                         fd = safe_close(fd);
1990                 }
1991
1992                 /* First write the GID map */
1993                 a = procfs_file_alloca(ppid, "gid_map");
1994                 fd = open(a, O_WRONLY|O_CLOEXEC);
1995                 if (fd < 0) {
1996                         r = -errno;
1997                         goto child_fail;
1998                 }
1999                 if (write(fd, gid_map, strlen(gid_map)) < 0) {
2000                         r = -errno;
2001                         goto child_fail;
2002                 }
2003                 fd = safe_close(fd);
2004
2005                 /* The write the UID map */
2006                 a = procfs_file_alloca(ppid, "uid_map");
2007                 fd = open(a, O_WRONLY|O_CLOEXEC);
2008                 if (fd < 0) {
2009                         r = -errno;
2010                         goto child_fail;
2011                 }
2012                 if (write(fd, uid_map, strlen(uid_map)) < 0) {
2013                         r = -errno;
2014                         goto child_fail;
2015                 }
2016
2017                 _exit(EXIT_SUCCESS);
2018
2019         child_fail:
2020                 (void) write(errno_pipe[1], &r, sizeof(r));
2021                 _exit(EXIT_FAILURE);
2022         }
2023
2024         errno_pipe[1] = safe_close(errno_pipe[1]);
2025
2026         if (unshare(CLONE_NEWUSER) < 0)
2027                 return -errno;
2028
2029         /* Let the child know that the namespace is ready now */
2030         if (write(unshare_ready_fd, &c, sizeof(c)) < 0)
2031                 return -errno;
2032
2033         /* Try to read an error code from the child */
2034         n = read(errno_pipe[0], &r, sizeof(r));
2035         if (n < 0)
2036                 return -errno;
2037         if (n == sizeof(r)) { /* an error code was sent to us */
2038                 if (r < 0)
2039                         return r;
2040                 return -EIO;
2041         }
2042         if (n != 0) /* on success we should have read 0 bytes */
2043                 return -EIO;
2044
2045         r = wait_for_terminate_and_check("(sd-userns)", pid, 0);
2046         pid = 0;
2047         if (r < 0)
2048                 return r;
2049         if (r != EXIT_SUCCESS) /* If something strange happened with the child, let's consider this fatal, too */
2050                 return -EIO;
2051
2052         return 0;
2053 }
2054
2055 static int setup_exec_directory(
2056                 const ExecContext *context,
2057                 const ExecParameters *params,
2058                 uid_t uid,
2059                 gid_t gid,
2060                 ExecDirectoryType type,
2061                 int *exit_status) {
2062
2063         static const int exit_status_table[_EXEC_DIRECTORY_TYPE_MAX] = {
2064                 [EXEC_DIRECTORY_RUNTIME] = EXIT_RUNTIME_DIRECTORY,
2065                 [EXEC_DIRECTORY_STATE] = EXIT_STATE_DIRECTORY,
2066                 [EXEC_DIRECTORY_CACHE] = EXIT_CACHE_DIRECTORY,
2067                 [EXEC_DIRECTORY_LOGS] = EXIT_LOGS_DIRECTORY,
2068                 [EXEC_DIRECTORY_CONFIGURATION] = EXIT_CONFIGURATION_DIRECTORY,
2069         };
2070         char **rt;
2071         int r;
2072
2073         assert(context);
2074         assert(params);
2075         assert(type >= 0 && type < _EXEC_DIRECTORY_TYPE_MAX);
2076         assert(exit_status);
2077
2078         if (!params->prefix[type])
2079                 return 0;
2080
2081         if (params->flags & EXEC_CHOWN_DIRECTORIES) {
2082                 if (!uid_is_valid(uid))
2083                         uid = 0;
2084                 if (!gid_is_valid(gid))
2085                         gid = 0;
2086         }
2087
2088         STRV_FOREACH(rt, context->directories[type].paths) {
2089                 _cleanup_free_ char *p = NULL, *pp = NULL;
2090
2091                 p = path_join(params->prefix[type], *rt);
2092                 if (!p) {
2093                         r = -ENOMEM;
2094                         goto fail;
2095                 }
2096
2097                 r = mkdir_parents_label(p, 0755);
2098                 if (r < 0)
2099                         goto fail;
2100
2101                 if (context->dynamic_user &&
2102                     (!IN_SET(type, EXEC_DIRECTORY_RUNTIME, EXEC_DIRECTORY_CONFIGURATION) ||
2103                      (type == EXEC_DIRECTORY_RUNTIME && context->runtime_directory_preserve_mode != EXEC_PRESERVE_NO))) {
2104                         _cleanup_free_ char *private_root = NULL;
2105
2106                         /* So, here's one extra complication when dealing with DynamicUser=1 units. In that case we
2107                          * want to avoid leaving a directory around fully accessible that is owned by a dynamic user
2108                          * whose UID is later on reused. To lock this down we use the same trick used by container
2109                          * managers to prohibit host users to get access to files of the same UID in containers: we
2110                          * place everything inside a directory that has an access mode of 0700 and is owned root:root,
2111                          * so that it acts as security boundary for unprivileged host code. We then use fs namespacing
2112                          * to make this directory permeable for the service itself.
2113                          *
2114                          * Specifically: for a service which wants a special directory "foo/" we first create a
2115                          * directory "private/" with access mode 0700 owned by root:root. Then we place "foo" inside of
2116                          * that directory (i.e. "private/foo/"), and make "foo" a symlink to "private/foo". This way,
2117                          * privileged host users can access "foo/" as usual, but unprivileged host users can't look
2118                          * into it. Inside of the namespaceof the container "private/" is replaced by a more liberally
2119                          * accessible tmpfs, into which the host's "private/foo/" is mounted under the same name, thus
2120                          * disabling the access boundary for the service and making sure it only gets access to the
2121                          * dirs it needs but no others. Tricky? Yes, absolutely, but it works!
2122                          *
2123                          * Note that we don't do this for EXEC_DIRECTORY_CONFIGURATION as that's assumed not to be
2124                          * owned by the service itself.
2125                          * Also, note that we don't do this for EXEC_DIRECTORY_RUNTIME as that's often used for sharing
2126                          * files or sockets with other services. */
2127
2128                         private_root = path_join(params->prefix[type], "private");
2129                         if (!private_root) {
2130                                 r = -ENOMEM;
2131                                 goto fail;
2132                         }
2133
2134                         /* First set up private root if it doesn't exist yet, with access mode 0700 and owned by root:root */
2135                         r = mkdir_safe_label(private_root, 0700, 0, 0, MKDIR_WARN_MODE);
2136                         if (r < 0)
2137                                 goto fail;
2138
2139                         pp = path_join(private_root, *rt);
2140                         if (!pp) {
2141                                 r = -ENOMEM;
2142                                 goto fail;
2143                         }
2144
2145                         /* Create all directories between the configured directory and this private root, and mark them 0755 */
2146                         r = mkdir_parents_label(pp, 0755);
2147                         if (r < 0)
2148                                 goto fail;
2149
2150                         if (is_dir(p, false) > 0 &&
2151                             (laccess(pp, F_OK) < 0 && errno == ENOENT)) {
2152
2153                                 /* Hmm, the private directory doesn't exist yet, but the normal one exists? If so, move
2154                                  * it over. Most likely the service has been upgraded from one that didn't use
2155                                  * DynamicUser=1, to one that does. */
2156
2157                                 if (rename(p, pp) < 0) {
2158                                         r = -errno;
2159                                         goto fail;
2160                                 }
2161                         } else {
2162                                 /* Otherwise, create the actual directory for the service */
2163
2164                                 r = mkdir_label(pp, context->directories[type].mode);
2165                                 if (r < 0 && r != -EEXIST)
2166                                         goto fail;
2167                         }
2168
2169                         /* And link it up from the original place */
2170                         r = symlink_idempotent(pp, p, true);
2171                         if (r < 0)
2172                                 goto fail;
2173
2174                 } else {
2175                         r = mkdir_label(p, context->directories[type].mode);
2176                         if (r < 0) {
2177                                 if (r != -EEXIST)
2178                                         goto fail;
2179
2180                                 if (type == EXEC_DIRECTORY_CONFIGURATION) {
2181                                         struct stat st;
2182
2183                                         /* Don't change the owner/access mode of the configuration directory,
2184                                          * as in the common case it is not written to by a service, and shall
2185                                          * not be writable. */
2186
2187                                         if (stat(p, &st) < 0) {
2188                                                 r = -errno;
2189                                                 goto fail;
2190                                         }
2191
2192                                         /* Still complain if the access mode doesn't match */
2193                                         if (((st.st_mode ^ context->directories[type].mode) & 07777) != 0)
2194                                                 log_warning("%s \'%s\' already exists but the mode is different. "
2195                                                             "(File system: %o %sMode: %o)",
2196                                                             exec_directory_type_to_string(type), *rt,
2197                                                             st.st_mode & 07777, exec_directory_type_to_string(type), context->directories[type].mode & 07777);
2198
2199                                         continue;
2200                                 }
2201                         }
2202                 }
2203
2204                 /* Lock down the access mode (we use chmod_and_chown() to make this idempotent. We don't
2205                  * specify UID/GID here, so that path_chown_recursive() can optimize things depending on the
2206                  * current UID/GID ownership.) */
2207                 r = chmod_and_chown(pp ?: p, context->directories[type].mode, UID_INVALID, GID_INVALID);
2208                 if (r < 0)
2209                         goto fail;
2210
2211                 /* Then, change the ownership of the whole tree, if necessary. When dynamic users are used we
2212                  * drop the suid/sgid bits, since we really don't want SUID/SGID files for dynamic UID/GID
2213                  * assignments to exist.*/
2214                 r = path_chown_recursive(pp ?: p, uid, gid, context->dynamic_user ? 01777 : 07777);
2215                 if (r < 0)
2216                         goto fail;
2217         }
2218
2219         return 0;
2220
2221 fail:
2222         *exit_status = exit_status_table[type];
2223         return r;
2224 }
2225
2226 #if ENABLE_SMACK
2227 static int setup_smack(
2228                 const ExecContext *context,
2229                 const ExecCommand *command) {
2230
2231         int r;
2232
2233         assert(context);
2234         assert(command);
2235
2236         if (context->smack_process_label) {
2237                 r = mac_smack_apply_pid(0, context->smack_process_label);
2238                 if (r < 0)
2239                         return r;
2240         }
2241 #ifdef SMACK_DEFAULT_PROCESS_LABEL
2242         else {
2243                 _cleanup_free_ char *exec_label = NULL;
2244
2245                 r = mac_smack_read(command->path, SMACK_ATTR_EXEC, &exec_label);
2246                 if (r < 0 && !IN_SET(r, -ENODATA, -EOPNOTSUPP))
2247                         return r;
2248
2249                 r = mac_smack_apply_pid(0, exec_label ? : SMACK_DEFAULT_PROCESS_LABEL);
2250                 if (r < 0)
2251                         return r;
2252         }
2253 #endif
2254
2255         return 0;
2256 }
2257 #endif
2258
2259 static int compile_bind_mounts(
2260                 const ExecContext *context,
2261                 const ExecParameters *params,
2262                 BindMount **ret_bind_mounts,
2263                 size_t *ret_n_bind_mounts,
2264                 char ***ret_empty_directories) {
2265
2266         _cleanup_strv_free_ char **empty_directories = NULL;
2267         BindMount *bind_mounts;
2268         size_t n, h = 0, i;
2269         ExecDirectoryType t;
2270         int r;
2271
2272         assert(context);
2273         assert(params);
2274         assert(ret_bind_mounts);
2275         assert(ret_n_bind_mounts);
2276         assert(ret_empty_directories);
2277
2278         n = context->n_bind_mounts;
2279         for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
2280                 if (!params->prefix[t])
2281                         continue;
2282
2283                 n += strv_length(context->directories[t].paths);
2284         }
2285
2286         if (n <= 0) {
2287                 *ret_bind_mounts = NULL;
2288                 *ret_n_bind_mounts = 0;
2289                 *ret_empty_directories = NULL;
2290                 return 0;
2291         }
2292
2293         bind_mounts = new(BindMount, n);
2294         if (!bind_mounts)
2295                 return -ENOMEM;
2296
2297         for (i = 0; i < context->n_bind_mounts; i++) {
2298                 BindMount *item = context->bind_mounts + i;
2299                 char *s, *d;
2300
2301                 s = strdup(item->source);
2302                 if (!s) {
2303                         r = -ENOMEM;
2304                         goto finish;
2305                 }
2306
2307                 d = strdup(item->destination);
2308                 if (!d) {
2309                         free(s);
2310                         r = -ENOMEM;
2311                         goto finish;
2312                 }
2313
2314                 bind_mounts[h++] = (BindMount) {
2315                         .source = s,
2316                         .destination = d,
2317                         .read_only = item->read_only,
2318                         .recursive = item->recursive,
2319                         .ignore_enoent = item->ignore_enoent,
2320                 };
2321         }
2322
2323         for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
2324                 char **suffix;
2325
2326                 if (!params->prefix[t])
2327                         continue;
2328
2329                 if (strv_isempty(context->directories[t].paths))
2330                         continue;
2331
2332                 if (context->dynamic_user &&
2333                     !IN_SET(t, EXEC_DIRECTORY_RUNTIME, EXEC_DIRECTORY_CONFIGURATION) &&
2334                     !(context->root_directory || context->root_image)) {
2335                         char *private_root;
2336
2337                         /* So this is for a dynamic user, and we need to make sure the process can access its own
2338                          * directory. For that we overmount the usually inaccessible "private" subdirectory with a
2339                          * tmpfs that makes it accessible and is empty except for the submounts we do this for. */
2340
2341                         private_root = strjoin(params->prefix[t], "/private");
2342                         if (!private_root) {
2343                                 r = -ENOMEM;
2344                                 goto finish;
2345                         }
2346
2347                         r = strv_consume(&empty_directories, private_root);
2348                         if (r < 0)
2349                                 goto finish;
2350                 }
2351
2352                 STRV_FOREACH(suffix, context->directories[t].paths) {
2353                         char *s, *d;
2354
2355                         if (context->dynamic_user &&
2356                             !IN_SET(t, EXEC_DIRECTORY_RUNTIME, EXEC_DIRECTORY_CONFIGURATION))
2357                                 s = strjoin(params->prefix[t], "/private/", *suffix);
2358                         else
2359                                 s = strjoin(params->prefix[t], "/", *suffix);
2360                         if (!s) {
2361                                 r = -ENOMEM;
2362                                 goto finish;
2363                         }
2364
2365                         if (context->dynamic_user &&
2366                             !IN_SET(t, EXEC_DIRECTORY_RUNTIME, EXEC_DIRECTORY_CONFIGURATION) &&
2367                             (context->root_directory || context->root_image))
2368                                 /* When RootDirectory= or RootImage= are set, then the symbolic link to the private
2369                                  * directory is not created on the root directory. So, let's bind-mount the directory
2370                                  * on the 'non-private' place. */
2371                                 d = strjoin(params->prefix[t], "/", *suffix);
2372                         else
2373                                 d = strdup(s);
2374                         if (!d) {
2375                                 free(s);
2376                                 r = -ENOMEM;
2377                                 goto finish;
2378                         }
2379
2380                         bind_mounts[h++] = (BindMount) {
2381                                 .source = s,
2382                                 .destination = d,
2383                                 .read_only = false,
2384                                 .nosuid = context->dynamic_user, /* don't allow suid/sgid when DynamicUser= is on */
2385                                 .recursive = true,
2386                                 .ignore_enoent = false,
2387                         };
2388                 }
2389         }
2390
2391         assert(h == n);
2392
2393         *ret_bind_mounts = bind_mounts;
2394         *ret_n_bind_mounts = n;
2395         *ret_empty_directories = TAKE_PTR(empty_directories);
2396
2397         return (int) n;
2398
2399 finish:
2400         bind_mount_free_many(bind_mounts, h);
2401         return r;
2402 }
2403
2404 static int apply_mount_namespace(
2405                 const Unit *u,
2406                 const ExecCommand *command,
2407                 const ExecContext *context,
2408                 const ExecParameters *params,
2409                 const ExecRuntime *runtime) {
2410
2411         _cleanup_strv_free_ char **empty_directories = NULL;
2412         char *tmp = NULL, *var = NULL;
2413         const char *root_dir = NULL, *root_image = NULL;
2414         NamespaceInfo ns_info;
2415         bool needs_sandboxing;
2416         BindMount *bind_mounts = NULL;
2417         size_t n_bind_mounts = 0;
2418         int r;
2419
2420         assert(context);
2421
2422         /* The runtime struct only contains the parent of the private /tmp,
2423          * which is non-accessible to world users. Inside of it there's a /tmp
2424          * that is sticky, and that's the one we want to use here. */
2425
2426         if (context->private_tmp && runtime) {
2427                 if (runtime->tmp_dir)
2428                         tmp = strjoina(runtime->tmp_dir, "/tmp");
2429                 if (runtime->var_tmp_dir)
2430                         var = strjoina(runtime->var_tmp_dir, "/tmp");
2431         }
2432
2433         if (params->flags & EXEC_APPLY_CHROOT) {
2434                 root_image = context->root_image;
2435
2436                 if (!root_image)
2437                         root_dir = context->root_directory;
2438         }
2439
2440         r = compile_bind_mounts(context, params, &bind_mounts, &n_bind_mounts, &empty_directories);
2441         if (r < 0)
2442                 return r;
2443
2444         needs_sandboxing = (params->flags & EXEC_APPLY_SANDBOXING) && !(command->flags & EXEC_COMMAND_FULLY_PRIVILEGED);
2445         if (needs_sandboxing)
2446                 ns_info = (NamespaceInfo) {
2447                         .ignore_protect_paths = false,
2448                         .private_dev = context->private_devices,
2449                         .protect_control_groups = context->protect_control_groups,
2450                         .protect_kernel_tunables = context->protect_kernel_tunables,
2451                         .protect_kernel_modules = context->protect_kernel_modules,
2452                         .protect_hostname = context->protect_hostname,
2453                         .mount_apivfs = context->mount_apivfs,
2454                         .private_mounts = context->private_mounts,
2455                 };
2456         else if (!context->dynamic_user && root_dir)
2457                 /*
2458                  * If DynamicUser=no and RootDirectory= is set then lets pass a relaxed
2459                  * sandbox info, otherwise enforce it, don't ignore protected paths and
2460                  * fail if we are enable to apply the sandbox inside the mount namespace.
2461                  */
2462                 ns_info = (NamespaceInfo) {
2463                         .ignore_protect_paths = true,
2464                 };
2465         else
2466                 ns_info = (NamespaceInfo) {};
2467
2468         if (context->mount_flags == MS_SHARED)
2469                 log_unit_debug(u, "shared mount propagation hidden by other fs namespacing unit settings: ignoring");
2470
2471         r = setup_namespace(root_dir, root_image,
2472                             &ns_info, context->read_write_paths,
2473                             needs_sandboxing ? context->read_only_paths : NULL,
2474                             needs_sandboxing ? context->inaccessible_paths : NULL,
2475                             empty_directories,
2476                             bind_mounts,
2477                             n_bind_mounts,
2478                             context->temporary_filesystems,
2479                             context->n_temporary_filesystems,
2480                             tmp,
2481                             var,
2482                             needs_sandboxing ? context->protect_home : PROTECT_HOME_NO,
2483                             needs_sandboxing ? context->protect_system : PROTECT_SYSTEM_NO,
2484                             context->mount_flags,
2485                             DISSECT_IMAGE_DISCARD_ON_LOOP);
2486
2487         bind_mount_free_many(bind_mounts, n_bind_mounts);
2488
2489         /* If we couldn't set up the namespace this is probably due to a missing capability. setup_namespace() reports
2490          * that with a special, recognizable error ENOANO. In this case, silently proceed, but only if exclusively
2491          * sandboxing options were used, i.e. nothing such as RootDirectory= or BindMount= that would result in a
2492          * completely different execution environment. */
2493         if (r == -ENOANO) {
2494                 if (n_bind_mounts == 0 &&
2495                     context->n_temporary_filesystems == 0 &&
2496                     !root_dir && !root_image &&
2497                     !context->dynamic_user) {
2498                         log_unit_debug(u, "Failed to set up namespace, assuming containerized execution and ignoring.");
2499                         return 0;
2500                 }
2501
2502                 log_unit_debug(u, "Failed to set up namespace, and refusing to continue since the selected namespacing options alter mount environment non-trivially.\n"
2503                                "Bind mounts: %zu, temporary filesystems: %zu, root directory: %s, root image: %s, dynamic user: %s",
2504                                n_bind_mounts, context->n_temporary_filesystems, yes_no(root_dir), yes_no(root_image), yes_no(context->dynamic_user));
2505
2506                 return -EOPNOTSUPP;
2507         }
2508
2509         return r;
2510 }
2511
2512 static int apply_working_directory(
2513                 const ExecContext *context,
2514                 const ExecParameters *params,
2515                 const char *home,
2516                 const bool needs_mount_ns,
2517                 int *exit_status) {
2518
2519         const char *d, *wd;
2520
2521         assert(context);
2522         assert(exit_status);
2523
2524         if (context->working_directory_home) {
2525
2526                 if (!home) {
2527                         *exit_status = EXIT_CHDIR;
2528                         return -ENXIO;
2529                 }
2530
2531                 wd = home;
2532
2533         } else if (context->working_directory)
2534                 wd = context->working_directory;
2535         else
2536                 wd = "/";
2537
2538         if (params->flags & EXEC_APPLY_CHROOT) {
2539                 if (!needs_mount_ns && context->root_directory)
2540                         if (chroot(context->root_directory) < 0) {
2541                                 *exit_status = EXIT_CHROOT;
2542                                 return -errno;
2543                         }
2544
2545                 d = wd;
2546         } else
2547                 d = prefix_roota(context->root_directory, wd);
2548
2549         if (chdir(d) < 0 && !context->working_directory_missing_ok) {
2550                 *exit_status = EXIT_CHDIR;
2551                 return -errno;
2552         }
2553
2554         return 0;
2555 }
2556
2557 static int setup_keyring(
2558                 const Unit *u,
2559                 const ExecContext *context,
2560                 const ExecParameters *p,
2561                 uid_t uid, gid_t gid) {
2562
2563         key_serial_t keyring;
2564         int r = 0;
2565         uid_t saved_uid;
2566         gid_t saved_gid;
2567
2568         assert(u);
2569         assert(context);
2570         assert(p);
2571
2572         /* Let's set up a new per-service "session" kernel keyring for each system service. This has the benefit that
2573          * each service runs with its own keyring shared among all processes of the service, but with no hook-up beyond
2574          * that scope, and in particular no link to the per-UID keyring. If we don't do this the keyring will be
2575          * automatically created on-demand and then linked to the per-UID keyring, by the kernel. The kernel's built-in
2576          * on-demand behaviour is very appropriate for login users, but probably not so much for system services, where
2577          * UIDs are not necessarily specific to a service but reused (at least in the case of UID 0). */
2578
2579         if (context->keyring_mode == EXEC_KEYRING_INHERIT)
2580                 return 0;
2581
2582         /* Acquiring a reference to the user keyring is nasty. We briefly change identity in order to get things set up
2583          * properly by the kernel. If we don't do that then we can't create it atomically, and that sucks for parallel
2584          * execution. This mimics what pam_keyinit does, too. Setting up session keyring, to be owned by the right user
2585          * & group is just as nasty as acquiring a reference to the user keyring. */
2586
2587         saved_uid = getuid();
2588         saved_gid = getgid();
2589
2590         if (gid_is_valid(gid) && gid != saved_gid) {
2591                 if (setregid(gid, -1) < 0)
2592                         return log_unit_error_errno(u, errno, "Failed to change GID for user keyring: %m");
2593         }
2594
2595         if (uid_is_valid(uid) && uid != saved_uid) {
2596                 if (setreuid(uid, -1) < 0) {
2597                         r = log_unit_error_errno(u, errno, "Failed to change UID for user keyring: %m");
2598                         goto out;
2599                 }
2600         }
2601
2602         keyring = keyctl(KEYCTL_JOIN_SESSION_KEYRING, 0, 0, 0, 0);
2603         if (keyring == -1) {
2604                 if (errno == ENOSYS)
2605                         log_unit_debug_errno(u, errno, "Kernel keyring not supported, ignoring.");
2606                 else if (IN_SET(errno, EACCES, EPERM))
2607                         log_unit_debug_errno(u, errno, "Kernel keyring access prohibited, ignoring.");
2608                 else if (errno == EDQUOT)
2609                         log_unit_debug_errno(u, errno, "Out of kernel keyrings to allocate, ignoring.");
2610                 else
2611                         r = log_unit_error_errno(u, errno, "Setting up kernel keyring failed: %m");
2612
2613                 goto out;
2614         }
2615
2616         /* When requested link the user keyring into the session keyring. */
2617         if (context->keyring_mode == EXEC_KEYRING_SHARED) {
2618
2619                 if (keyctl(KEYCTL_LINK,
2620                            KEY_SPEC_USER_KEYRING,
2621                            KEY_SPEC_SESSION_KEYRING, 0, 0) < 0) {
2622                         r = log_unit_error_errno(u, errno, "Failed to link user keyring into session keyring: %m");
2623                         goto out;
2624                 }
2625         }
2626
2627         /* Restore uid/gid back */
2628         if (uid_is_valid(uid) && uid != saved_uid) {
2629                 if (setreuid(saved_uid, -1) < 0) {
2630                         r = log_unit_error_errno(u, errno, "Failed to change UID back for user keyring: %m");
2631                         goto out;
2632                 }
2633         }
2634
2635         if (gid_is_valid(gid) && gid != saved_gid) {
2636                 if (setregid(saved_gid, -1) < 0)
2637                         return log_unit_error_errno(u, errno, "Failed to change GID back for user keyring: %m");
2638         }
2639
2640         /* Populate they keyring with the invocation ID by default, as original saved_uid. */
2641         if (!sd_id128_is_null(u->invocation_id)) {
2642                 key_serial_t key;
2643
2644                 key = add_key("user", "invocation_id", &u->invocation_id, sizeof(u->invocation_id), KEY_SPEC_SESSION_KEYRING);
2645                 if (key == -1)
2646                         log_unit_debug_errno(u, errno, "Failed to add invocation ID to keyring, ignoring: %m");
2647                 else {
2648                         if (keyctl(KEYCTL_SETPERM, key,
2649                                    KEY_POS_VIEW|KEY_POS_READ|KEY_POS_SEARCH|
2650                                    KEY_USR_VIEW|KEY_USR_READ|KEY_USR_SEARCH, 0, 0) < 0)
2651                                 r = log_unit_error_errno(u, errno, "Failed to restrict invocation ID permission: %m");
2652                 }
2653         }
2654
2655 out:
2656         /* Revert back uid & gid for the the last time, and exit */
2657         /* no extra logging, as only the first already reported error matters */
2658         if (getuid() != saved_uid)
2659                 (void) setreuid(saved_uid, -1);
2660
2661         if (getgid() != saved_gid)
2662                 (void) setregid(saved_gid, -1);
2663
2664         return r;
2665 }
2666
2667 static void append_socket_pair(int *array, size_t *n, const int pair[static 2]) {
2668         assert(array);
2669         assert(n);
2670
2671         if (!pair)
2672                 return;
2673
2674         if (pair[0] >= 0)
2675                 array[(*n)++] = pair[0];
2676         if (pair[1] >= 0)
2677                 array[(*n)++] = pair[1];
2678 }
2679
2680 static int close_remaining_fds(
2681                 const ExecParameters *params,
2682                 const ExecRuntime *runtime,
2683                 const DynamicCreds *dcreds,
2684                 int user_lookup_fd,
2685                 int socket_fd,
2686                 int exec_fd,
2687                 int *fds, size_t n_fds) {
2688
2689         size_t n_dont_close = 0;
2690         int dont_close[n_fds + 12];
2691
2692         assert(params);
2693
2694         if (params->stdin_fd >= 0)
2695                 dont_close[n_dont_close++] = params->stdin_fd;
2696         if (params->stdout_fd >= 0)
2697                 dont_close[n_dont_close++] = params->stdout_fd;
2698         if (params->stderr_fd >= 0)
2699                 dont_close[n_dont_close++] = params->stderr_fd;
2700
2701         if (socket_fd >= 0)
2702                 dont_close[n_dont_close++] = socket_fd;
2703         if (exec_fd >= 0)
2704                 dont_close[n_dont_close++] = exec_fd;
2705         if (n_fds > 0) {
2706                 memcpy(dont_close + n_dont_close, fds, sizeof(int) * n_fds);
2707                 n_dont_close += n_fds;
2708         }
2709
2710         if (runtime)
2711                 append_socket_pair(dont_close, &n_dont_close, runtime->netns_storage_socket);
2712
2713         if (dcreds) {
2714                 if (dcreds->user)
2715                         append_socket_pair(dont_close, &n_dont_close, dcreds->user->storage_socket);
2716                 if (dcreds->group)
2717                         append_socket_pair(dont_close, &n_dont_close, dcreds->group->storage_socket);
2718         }
2719
2720         if (user_lookup_fd >= 0)
2721                 dont_close[n_dont_close++] = user_lookup_fd;
2722
2723         return close_all_fds(dont_close, n_dont_close);
2724 }
2725
2726 static int send_user_lookup(
2727                 Unit *unit,
2728                 int user_lookup_fd,
2729                 uid_t uid,
2730                 gid_t gid) {
2731
2732         assert(unit);
2733
2734         /* Send the resolved UID/GID to PID 1 after we learnt it. We send a single datagram, containing the UID/GID
2735          * data as well as the unit name. Note that we suppress sending this if no user/group to resolve was
2736          * specified. */
2737
2738         if (user_lookup_fd < 0)
2739                 return 0;
2740
2741         if (!uid_is_valid(uid) && !gid_is_valid(gid))
2742                 return 0;
2743
2744         if (writev(user_lookup_fd,
2745                (struct iovec[]) {
2746                            IOVEC_INIT(&uid, sizeof(uid)),
2747                            IOVEC_INIT(&gid, sizeof(gid)),
2748                            IOVEC_INIT_STRING(unit->id) }, 3) < 0)
2749                 return -errno;
2750
2751         return 0;
2752 }
2753
2754 static int acquire_home(const ExecContext *c, uid_t uid, const char** home, char **buf) {
2755         int r;
2756
2757         assert(c);
2758         assert(home);
2759         assert(buf);
2760
2761         /* If WorkingDirectory=~ is set, try to acquire a usable home directory. */
2762
2763         if (*home)
2764                 return 0;
2765
2766         if (!c->working_directory_home)
2767                 return 0;
2768
2769         r = get_home_dir(buf);
2770         if (r < 0)
2771                 return r;
2772
2773         *home = *buf;
2774         return 1;
2775 }
2776
2777 static int compile_suggested_paths(const ExecContext *c, const ExecParameters *p, char ***ret) {
2778         _cleanup_strv_free_ char ** list = NULL;
2779         ExecDirectoryType t;
2780         int r;
2781
2782         assert(c);
2783         assert(p);
2784         assert(ret);
2785
2786         assert(c->dynamic_user);
2787
2788         /* Compile a list of paths that it might make sense to read the owning UID from to use as initial candidate for
2789          * dynamic UID allocation, in order to save us from doing costly recursive chown()s of the special
2790          * directories. */
2791
2792         for (t = 0; t < _EXEC_DIRECTORY_TYPE_MAX; t++) {
2793                 char **i;
2794
2795                 if (t == EXEC_DIRECTORY_CONFIGURATION)
2796                         continue;
2797
2798                 if (!p->prefix[t])
2799                         continue;
2800
2801                 STRV_FOREACH(i, c->directories[t].paths) {
2802                         char *e;
2803
2804                         if (t == EXEC_DIRECTORY_RUNTIME)
2805                                 e = strjoin(p->prefix[t], "/", *i);
2806                         else
2807                                 e = strjoin(p->prefix[t], "/private/", *i);
2808                         if (!e)
2809                                 return -ENOMEM;
2810
2811                         r = strv_consume(&list, e);
2812                         if (r < 0)
2813                                 return r;
2814                 }
2815         }
2816
2817         *ret = TAKE_PTR(list);
2818
2819         return 0;
2820 }
2821
2822 static char *exec_command_line(char **argv);
2823
2824 static int exec_parameters_get_cgroup_path(const ExecParameters *params, char **ret) {
2825         bool using_subcgroup;
2826         char *p;
2827
2828         assert(params);
2829         assert(ret);
2830
2831         if (!params->cgroup_path)
2832                 return -EINVAL;
2833
2834         /* If we are called for a unit where cgroup delegation is on, and the payload created its own populated
2835          * subcgroup (which we expect it to do, after all it asked for delegation), then we cannot place the control
2836          * processes started after the main unit's process in the unit's main cgroup because it is now an inner one,
2837          * and inner cgroups may not contain processes. Hence, if delegation is on, and this is a control process,
2838          * let's use ".control" as subcgroup instead. Note that we do so only for ExecStartPost=, ExecReload=,
2839          * ExecStop=, ExecStopPost=, i.e. for the commands where the main process is already forked. For ExecStartPre=
2840          * this is not necessary, the cgroup is still empty. We distinguish these cases with the EXEC_CONTROL_CGROUP
2841          * flag, which is only passed for the former statements, not for the latter. */
2842
2843         using_subcgroup = FLAGS_SET(params->flags, EXEC_CONTROL_CGROUP|EXEC_CGROUP_DELEGATE|EXEC_IS_CONTROL);
2844         if (using_subcgroup)
2845                 p = strjoin(params->cgroup_path, "/.control");
2846         else
2847                 p = strdup(params->cgroup_path);
2848         if (!p)
2849                 return -ENOMEM;
2850
2851         *ret = p;
2852         return using_subcgroup;
2853 }
2854
2855 static int exec_child(
2856                 Unit *unit,
2857                 const ExecCommand *command,
2858                 const ExecContext *context,
2859                 const ExecParameters *params,
2860                 ExecRuntime *runtime,
2861                 DynamicCreds *dcreds,
2862                 int socket_fd,
2863                 int named_iofds[3],
2864                 int *fds,
2865                 size_t n_socket_fds,
2866                 size_t n_storage_fds,
2867                 char **files_env,
2868                 int user_lookup_fd,
2869                 int *exit_status) {
2870
2871         _cleanup_strv_free_ char **our_env = NULL, **pass_env = NULL, **accum_env = NULL, **replaced_argv = NULL;
2872         int *fds_with_exec_fd, n_fds_with_exec_fd, r, ngids = 0, exec_fd = -1;
2873         _cleanup_free_ gid_t *supplementary_gids = NULL;
2874         const char *username = NULL, *groupname = NULL;
2875         _cleanup_free_ char *home_buffer = NULL;
2876         const char *home = NULL, *shell = NULL;
2877         char **final_argv = NULL;
2878         dev_t journal_stream_dev = 0;
2879         ino_t journal_stream_ino = 0;
2880         bool needs_sandboxing,          /* Do we need to set up full sandboxing? (i.e. all namespacing, all MAC stuff, caps, yadda yadda */
2881                 needs_setuid,           /* Do we need to do the actual setresuid()/setresgid() calls? */
2882                 needs_mount_namespace,  /* Do we need to set up a mount namespace for this kernel? */
2883                 needs_ambient_hack;     /* Do we need to apply the ambient capabilities hack? */
2884 #if HAVE_SELINUX
2885         _cleanup_free_ char *mac_selinux_context_net = NULL;
2886         bool use_selinux = false;
2887 #endif
2888 #if ENABLE_SMACK
2889         bool use_smack = false;
2890 #endif
2891 #if HAVE_APPARMOR
2892         bool use_apparmor = false;
2893 #endif
2894         uid_t uid = UID_INVALID;
2895         gid_t gid = GID_INVALID;
2896         size_t n_fds;
2897         ExecDirectoryType dt;
2898         int secure_bits;
2899
2900         assert(unit);
2901         assert(command);
2902         assert(context);
2903         assert(params);
2904         assert(exit_status);
2905
2906         rename_process_from_path(command->path);
2907
2908         /* We reset exactly these signals, since they are the
2909          * only ones we set to SIG_IGN in the main daemon. All
2910          * others we leave untouched because we set them to
2911          * SIG_DFL or a valid handler initially, both of which
2912          * will be demoted to SIG_DFL. */
2913         (void) default_signals(SIGNALS_CRASH_HANDLER,
2914                                SIGNALS_IGNORE, -1);
2915
2916         if (context->ignore_sigpipe)
2917                 (void) ignore_signals(SIGPIPE, -1);
2918
2919         r = reset_signal_mask();
2920         if (r < 0) {
2921                 *exit_status = EXIT_SIGNAL_MASK;
2922                 return log_unit_error_errno(unit, r, "Failed to set process signal mask: %m");
2923         }
2924
2925         if (params->idle_pipe)
2926                 do_idle_pipe_dance(params->idle_pipe);
2927
2928         /* Close fds we don't need very early to make sure we don't block init reexecution because it cannot bind its
2929          * sockets. Among the fds we close are the logging fds, and we want to keep them closed, so that we don't have
2930          * any fds open we don't really want open during the transition. In order to make logging work, we switch the
2931          * log subsystem into open_when_needed mode, so that it reopens the logs on every single log call. */
2932
2933         log_forget_fds();
2934         log_set_open_when_needed(true);
2935
2936         /* In case anything used libc syslog(), close this here, too */
2937         closelog();
2938
2939         n_fds = n_socket_fds + n_storage_fds;
2940         r = close_remaining_fds(params, runtime, dcreds, user_lookup_fd, socket_fd, params->exec_fd, fds, n_fds);
2941         if (r < 0) {
2942                 *exit_status = EXIT_FDS;
2943                 return log_unit_error_errno(unit, r, "Failed to close unwanted file descriptors: %m");
2944         }
2945
2946         if (!context->same_pgrp)
2947                 if (setsid() < 0) {
2948                         *exit_status = EXIT_SETSID;
2949                         return log_unit_error_errno(unit, errno, "Failed to create new process session: %m");
2950                 }
2951
2952         exec_context_tty_reset(context, params);
2953
2954         if (unit_shall_confirm_spawn(unit)) {
2955                 const char *vc = params->confirm_spawn;
2956                 _cleanup_free_ char *cmdline = NULL;
2957
2958                 cmdline = exec_command_line(command->argv);
2959                 if (!cmdline) {
2960                         *exit_status = EXIT_MEMORY;
2961                         return log_oom();
2962                 }
2963
2964                 r = ask_for_confirmation(vc, unit, cmdline);
2965                 if (r != CONFIRM_EXECUTE) {
2966                         if (r == CONFIRM_PRETEND_SUCCESS) {
2967                                 *exit_status = EXIT_SUCCESS;
2968                                 return 0;
2969                         }
2970                         *exit_status = EXIT_CONFIRM;
2971                         log_unit_error(unit, "Execution cancelled by the user");
2972                         return -ECANCELED;
2973                 }
2974         }
2975
2976         /* We are about to invoke NSS and PAM modules. Let's tell them what we are doing here, maybe they care. This is
2977          * used by nss-resolve to disable itself when we are about to start systemd-resolved, to avoid deadlocks. Note
2978          * that these env vars do not survive the execve(), which means they really only apply to the PAM and NSS
2979          * invocations themselves. Also note that while we'll only invoke NSS modules involved in user management they
2980          * might internally call into other NSS modules that are involved in hostname resolution, we never know. */
2981         if (setenv("SYSTEMD_ACTIVATION_UNIT", unit->id, true) != 0 ||
2982             setenv("SYSTEMD_ACTIVATION_SCOPE", MANAGER_IS_SYSTEM(unit->manager) ? "system" : "user", true) != 0) {
2983                 *exit_status = EXIT_MEMORY;
2984                 return log_unit_error_errno(unit, errno, "Failed to update environment: %m");
2985         }
2986
2987         if (context->dynamic_user && dcreds) {
2988                 _cleanup_strv_free_ char **suggested_paths = NULL;
2989
2990                 /* On top of that, make sure we bypass our own NSS module nss-systemd comprehensively for any NSS
2991                  * checks, if DynamicUser=1 is used, as we shouldn't create a feedback loop with ourselves here.*/
2992                 if (putenv((char*) "SYSTEMD_NSS_DYNAMIC_BYPASS=1") != 0) {
2993                         *exit_status = EXIT_USER;
2994                         return log_unit_error_errno(unit, errno, "Failed to update environment: %m");
2995                 }
2996
2997                 r = compile_suggested_paths(context, params, &suggested_paths);
2998                 if (r < 0) {
2999                         *exit_status = EXIT_MEMORY;
3000                         return log_oom();
3001                 }
3002
3003                 r = dynamic_creds_realize(dcreds, suggested_paths, &uid, &gid);
3004                 if (r < 0) {
3005                         *exit_status = EXIT_USER;
3006                         if (r == -EILSEQ) {
3007                                 log_unit_error(unit, "Failed to update dynamic user credentials: User or group with specified name already exists.");
3008                                 return -EOPNOTSUPP;
3009                         }
3010                         return log_unit_error_errno(unit, r, "Failed to update dynamic user credentials: %m");
3011                 }
3012
3013                 if (!uid_is_valid(uid)) {
3014                         *exit_status = EXIT_USER;
3015                         log_unit_error(unit, "UID validation failed for \""UID_FMT"\"", uid);
3016                         return -ESRCH;
3017                 }
3018
3019                 if (!gid_is_valid(gid)) {
3020                         *exit_status = EXIT_USER;
3021                         log_unit_error(unit, "GID validation failed for \""GID_FMT"\"", gid);
3022                         return -ESRCH;
3023                 }
3024
3025                 if (dcreds->user)
3026                         username = dcreds->user->name;
3027
3028         } else {
3029                 r = get_fixed_user(context, &username, &uid, &gid, &home, &shell);
3030                 if (r < 0) {
3031                         *exit_status = EXIT_USER;
3032                         return log_unit_error_errno(unit, r, "Failed to determine user credentials: %m");
3033                 }
3034
3035                 r = get_fixed_group(context, &groupname, &gid);
3036                 if (r < 0) {
3037                         *exit_status = EXIT_GROUP;
3038                         return log_unit_error_errno(unit, r, "Failed to determine group credentials: %m");
3039                 }
3040         }
3041
3042         /* Initialize user supplementary groups and get SupplementaryGroups= ones */
3043         r = get_supplementary_groups(context, username, groupname, gid,
3044                                      &supplementary_gids, &ngids);
3045         if (r < 0) {
3046                 *exit_status = EXIT_GROUP;
3047                 return log_unit_error_errno(unit, r, "Failed to determine supplementary groups: %m");
3048         }
3049
3050         r = send_user_lookup(unit, user_lookup_fd, uid, gid);
3051         if (r < 0) {
3052                 *exit_status = EXIT_USER;
3053                 return log_unit_error_errno(unit, r, "Failed to send user credentials to PID1: %m");
3054         }
3055
3056         user_lookup_fd = safe_close(user_lookup_fd);
3057
3058         r = acquire_home(context, uid, &home, &home_buffer);
3059         if (r < 0) {
3060                 *exit_status = EXIT_CHDIR;
3061                 return log_unit_error_errno(unit, r, "Failed to determine $HOME for user: %m");
3062         }
3063
3064         /* If a socket is connected to STDIN/STDOUT/STDERR, we
3065          * must sure to drop O_NONBLOCK */
3066         if (socket_fd >= 0)
3067                 (void) fd_nonblock(socket_fd, false);
3068
3069         /* Journald will try to look-up our cgroup in order to populate _SYSTEMD_CGROUP and _SYSTEMD_UNIT fields.
3070          * Hence we need to migrate to the target cgroup from init.scope before connecting to journald */
3071         if (params->cgroup_path) {
3072                 _cleanup_free_ char *p = NULL;
3073
3074                 r = exec_parameters_get_cgroup_path(params, &p);
3075                 if (r < 0) {
3076                         *exit_status = EXIT_CGROUP;
3077                         return log_unit_error_errno(unit, r, "Failed to acquire cgroup path: %m");
3078                 }
3079
3080                 r = cg_attach_everywhere(params->cgroup_supported, p, 0, NULL, NULL);
3081                 if (r < 0) {
3082                         *exit_status = EXIT_CGROUP;
3083                         return log_unit_error_errno(unit, r, "Failed to attach to cgroup %s: %m", p);
3084                 }
3085         }
3086
3087         if (context->network_namespace_path && runtime && runtime->netns_storage_socket[0] >= 0) {
3088                 r = open_netns_path(runtime->netns_storage_socket, context->network_namespace_path);
3089                 if (r < 0) {
3090                         *exit_status = EXIT_NETWORK;
3091                         return log_unit_error_errno(unit, r, "Failed to open network namespace path %s: %m", context->network_namespace_path);
3092                 }
3093         }
3094
3095         r = setup_input(context, params, socket_fd, named_iofds);
3096         if (r < 0) {
3097                 *exit_status = EXIT_STDIN;
3098                 return log_unit_error_errno(unit, r, "Failed to set up standard input: %m");
3099         }
3100
3101         r = setup_output(unit, context, params, STDOUT_FILENO, socket_fd, named_iofds, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
3102         if (r < 0) {
3103                 *exit_status = EXIT_STDOUT;
3104                 return log_unit_error_errno(unit, r, "Failed to set up standard output: %m");
3105         }
3106
3107         r = setup_output(unit, context, params, STDERR_FILENO, socket_fd, named_iofds, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
3108         if (r < 0) {
3109                 *exit_status = EXIT_STDERR;
3110                 return log_unit_error_errno(unit, r, "Failed to set up standard error output: %m");
3111         }
3112
3113         if (context->oom_score_adjust_set) {
3114                 /* When we can't make this change due to EPERM, then let's silently skip over it. User namespaces
3115                  * prohibit write access to this file, and we shouldn't trip up over that. */
3116                 r = set_oom_score_adjust(context->oom_score_adjust);
3117                 if (IN_SET(r, -EPERM, -EACCES))
3118                         log_unit_debug_errno(unit, r, "Failed to adjust OOM setting, assuming containerized execution, ignoring: %m");
3119                 else if (r < 0) {
3120                         *exit_status = EXIT_OOM_ADJUST;
3121                         return log_unit_error_errno(unit, r, "Failed to adjust OOM setting: %m");
3122                 }
3123         }
3124
3125         if (context->nice_set)
3126                 if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
3127                         *exit_status = EXIT_NICE;
3128                         return log_unit_error_errno(unit, errno, "Failed to set up process scheduling priority (nice level): %m");
3129                 }
3130
3131         if (context->cpu_sched_set) {
3132                 struct sched_param param = {
3133                         .sched_priority = context->cpu_sched_priority,
3134                 };
3135
3136                 r = sched_setscheduler(0,
3137                                        context->cpu_sched_policy |
3138                                        (context->cpu_sched_reset_on_fork ?
3139                                         SCHED_RESET_ON_FORK : 0),
3140                                        &param);
3141                 if (r < 0) {
3142                         *exit_status = EXIT_SETSCHEDULER;
3143                         return log_unit_error_errno(unit, errno, "Failed to set up CPU scheduling: %m");
3144                 }
3145         }
3146
3147         if (context->cpu_set.set)
3148                 if (sched_setaffinity(0, context->cpu_set.allocated, context->cpu_set.set) < 0) {
3149                         *exit_status = EXIT_CPUAFFINITY;
3150                         return log_unit_error_errno(unit, errno, "Failed to set up CPU affinity: %m");
3151                 }
3152
3153         if (context->ioprio_set)
3154                 if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {
3155                         *exit_status = EXIT_IOPRIO;
3156                         return log_unit_error_errno(unit, errno, "Failed to set up IO scheduling priority: %m");
3157                 }
3158
3159         if (context->timer_slack_nsec != NSEC_INFINITY)
3160                 if (prctl(PR_SET_TIMERSLACK, context->timer_slack_nsec) < 0) {
3161                         *exit_status = EXIT_TIMERSLACK;
3162                         return log_unit_error_errno(unit, errno, "Failed to set up timer slack: %m");
3163                 }
3164
3165         if (context->personality != PERSONALITY_INVALID) {
3166                 r = safe_personality(context->personality);
3167                 if (r < 0) {
3168                         *exit_status = EXIT_PERSONALITY;
3169                         return log_unit_error_errno(unit, r, "Failed to set up execution domain (personality): %m");
3170                 }
3171         }
3172
3173         if (context->utmp_id)
3174                 utmp_put_init_process(context->utmp_id, getpid_cached(), getsid(0),
3175                                       context->tty_path,
3176                                       context->utmp_mode == EXEC_UTMP_INIT  ? INIT_PROCESS :
3177                                       context->utmp_mode == EXEC_UTMP_LOGIN ? LOGIN_PROCESS :
3178                                       USER_PROCESS,
3179                                       username);
3180
3181         if (uid_is_valid(uid)) {
3182                 r = chown_terminal(STDIN_FILENO, uid);
3183                 if (r < 0) {
3184                         *exit_status = EXIT_STDIN;
3185                         return log_unit_error_errno(unit, r, "Failed to change ownership of terminal: %m");
3186                 }
3187         }
3188
3189         /* If delegation is enabled we'll pass ownership of the cgroup to the user of the new process. On cgroup v1
3190          * this is only about systemd's own hierarchy, i.e. not the controller hierarchies, simply because that's not
3191          * safe. On cgroup v2 there's only one hierarchy anyway, and delegation is safe there, hence in that case only
3192          * touch a single hierarchy too. */
3193         if (params->cgroup_path && context->user && (params->flags & EXEC_CGROUP_DELEGATE)) {
3194                 r = cg_set_access(SYSTEMD_CGROUP_CONTROLLER, params->cgroup_path, uid, gid);
3195                 if (r < 0) {
3196                         *exit_status = EXIT_CGROUP;
3197                         return log_unit_error_errno(unit, r, "Failed to adjust control group access: %m");
3198                 }
3199         }
3200
3201         for (dt = 0; dt < _EXEC_DIRECTORY_TYPE_MAX; dt++) {
3202                 r = setup_exec_directory(context, params, uid, gid, dt, exit_status);
3203                 if (r < 0)
3204                         return log_unit_error_errno(unit, r, "Failed to set up special execution directory in %s: %m", params->prefix[dt]);
3205         }
3206
3207         r = build_environment(
3208                         unit,
3209                         context,
3210                         params,
3211                         n_fds,
3212                         home,
3213                         username,
3214                         shell,
3215                         journal_stream_dev,
3216                         journal_stream_ino,
3217                         &our_env);
3218         if (r < 0) {
3219                 *exit_status = EXIT_MEMORY;
3220                 return log_oom();
3221         }
3222
3223         r = build_pass_environment(context, &pass_env);
3224         if (r < 0) {
3225                 *exit_status = EXIT_MEMORY;
3226                 return log_oom();
3227         }
3228
3229         accum_env = strv_env_merge(5,
3230                                    params->environment,
3231                                    our_env,
3232                                    pass_env,
3233                                    context->environment,
3234                                    files_env,
3235                                    NULL);
3236         if (!accum_env) {
3237                 *exit_status = EXIT_MEMORY;
3238                 return log_oom();
3239         }
3240         accum_env = strv_env_clean(accum_env);
3241
3242         (void) umask(context->umask);
3243
3244         r = setup_keyring(unit, context, params, uid, gid);
3245         if (r < 0) {
3246                 *exit_status = EXIT_KEYRING;
3247                 return log_unit_error_errno(unit, r, "Failed to set up kernel keyring: %m");
3248         }
3249
3250         /* We need sandboxing if the caller asked us to apply it and the command isn't explicitly excepted from it */
3251         needs_sandboxing = (params->flags & EXEC_APPLY_SANDBOXING) && !(command->flags & EXEC_COMMAND_FULLY_PRIVILEGED);
3252
3253         /* 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 */
3254         needs_ambient_hack = (params->flags & EXEC_APPLY_SANDBOXING) && (command->flags & EXEC_COMMAND_AMBIENT_MAGIC) && !ambient_capabilities_supported();
3255
3256         /* 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 */
3257         if (needs_ambient_hack)
3258                 needs_setuid = false;
3259         else
3260                 needs_setuid = (params->flags & EXEC_APPLY_SANDBOXING) && !(command->flags & (EXEC_COMMAND_FULLY_PRIVILEGED|EXEC_COMMAND_NO_SETUID));
3261
3262         if (needs_sandboxing) {
3263                 /* MAC enablement checks need to be done before a new mount ns is created, as they rely on /sys being
3264                  * present. The actual MAC context application will happen later, as late as possible, to avoid
3265                  * impacting our own code paths. */
3266
3267 #if HAVE_SELINUX
3268                 use_selinux = mac_selinux_use();
3269 #endif
3270 #if ENABLE_SMACK
3271                 use_smack = mac_smack_use();
3272 #endif
3273 #if HAVE_APPARMOR
3274                 use_apparmor = mac_apparmor_use();
3275 #endif
3276         }
3277
3278         if (needs_sandboxing) {
3279                 int which_failed;
3280
3281                 /* Let's set the resource limits before we call into PAM, so that pam_limits wins over what
3282                  * is set here. (See below.) */
3283
3284                 r = setrlimit_closest_all((const struct rlimit* const *) context->rlimit, &which_failed);
3285                 if (r < 0) {
3286                         *exit_status = EXIT_LIMITS;
3287                         return log_unit_error_errno(unit, r, "Failed to adjust resource limit RLIMIT_%s: %m", rlimit_to_string(which_failed));
3288                 }
3289         }
3290
3291         if (needs_setuid) {
3292
3293                 /* Let's call into PAM after we set up our own idea of resource limits to that pam_limits
3294                  * wins here. (See above.) */
3295
3296                 if (context->pam_name && username) {
3297                         r = setup_pam(context->pam_name, username, uid, gid, context->tty_path, &accum_env, fds, n_fds);
3298                         if (r < 0) {
3299                                 *exit_status = EXIT_PAM;
3300                                 return log_unit_error_errno(unit, r, "Failed to set up PAM session: %m");
3301                         }
3302                 }
3303         }
3304
3305         if ((context->private_network || context->network_namespace_path) && runtime && runtime->netns_storage_socket[0] >= 0) {
3306
3307                 if (ns_type_supported(NAMESPACE_NET)) {
3308                         r = setup_netns(runtime->netns_storage_socket);
3309                         if (r < 0) {
3310                                 *exit_status = EXIT_NETWORK;
3311                                 return log_unit_error_errno(unit, r, "Failed to set up network namespacing: %m");
3312                         }
3313                 } else if (context->network_namespace_path) {
3314                         *exit_status = EXIT_NETWORK;
3315                         return log_unit_error_errno(unit, SYNTHETIC_ERRNO(EOPNOTSUPP), "NetworkNamespacePath= is not supported, refusing.");
3316                 } else
3317                         log_unit_warning(unit, "PrivateNetwork=yes is configured, but the kernel does not support network namespaces, ignoring.");
3318         }
3319
3320         needs_mount_namespace = exec_needs_mount_namespace(context, params, runtime);
3321         if (needs_mount_namespace) {
3322                 r = apply_mount_namespace(unit, command, context, params, runtime);
3323                 if (r < 0) {
3324                         *exit_status = EXIT_NAMESPACE;
3325                         return log_unit_error_errno(unit, r, "Failed to set up mount namespacing: %m");
3326                 }
3327         }
3328
3329         if (context->protect_hostname) {
3330                 if (ns_type_supported(NAMESPACE_UTS)) {
3331                         if (unshare(CLONE_NEWUTS) < 0) {
3332                                 *exit_status = EXIT_NAMESPACE;
3333                                 return log_unit_error_errno(unit, errno, "Failed to set up UTS namespacing: %m");
3334                         }
3335                 } else
3336                         log_unit_warning(unit, "ProtectHostname=yes is configured, but the kernel does not support UTS namespaces, ignoring namespace setup.");
3337 #if HAVE_SECCOMP
3338                 r = seccomp_protect_hostname();
3339                 if (r < 0) {
3340                         *exit_status = EXIT_SECCOMP;
3341                         return log_unit_error_errno(unit, r, "Failed to apply hostname restrictions: %m");
3342                 }
3343 #endif
3344         }
3345
3346         /* Drop groups as early as possbile */
3347         if (needs_setuid) {
3348                 r = enforce_groups(gid, supplementary_gids, ngids);
3349                 if (r < 0) {
3350                         *exit_status = EXIT_GROUP;
3351                         return log_unit_error_errno(unit, r, "Changing group credentials failed: %m");
3352                 }
3353         }
3354
3355         if (needs_sandboxing) {
3356 #if HAVE_SELINUX
3357                 if (use_selinux && params->selinux_context_net && socket_fd >= 0) {
3358                         r = mac_selinux_get_child_mls_label(socket_fd, command->path, context->selinux_context, &mac_selinux_context_net);
3359                         if (r < 0) {
3360                                 *exit_status = EXIT_SELINUX_CONTEXT;
3361                                 return log_unit_error_errno(unit, r, "Failed to determine SELinux context: %m");
3362                         }
3363                 }
3364 #endif
3365
3366                 if (context->private_users) {
3367                         r = setup_private_users(uid, gid);
3368                         if (r < 0) {
3369                                 *exit_status = EXIT_USER;
3370                                 return log_unit_error_errno(unit, r, "Failed to set up user namespacing: %m");
3371                         }
3372                 }
3373         }
3374
3375         /* We repeat the fd closing here, to make sure that nothing is leaked from the PAM modules. Note that we are
3376          * more aggressive this time since socket_fd and the netns fds we don't need anymore. We do keep the exec_fd
3377          * however if we have it as we want to keep it open until the final execve(). */
3378
3379         if (params->exec_fd >= 0) {
3380                 exec_fd = params->exec_fd;
3381
3382                 if (exec_fd < 3 + (int) n_fds) {
3383                         int moved_fd;
3384
3385                         /* Let's move the exec fd far up, so that it's outside of the fd range we want to pass to the
3386                          * process we are about to execute. */
3387
3388                         moved_fd = fcntl(exec_fd, F_DUPFD_CLOEXEC, 3 + (int) n_fds);
3389                         if (moved_fd < 0) {
3390                                 *exit_status = EXIT_FDS;
3391                                 return log_unit_error_errno(unit, errno, "Couldn't move exec fd up: %m");
3392                         }
3393
3394                         safe_close(exec_fd);
3395                         exec_fd = moved_fd;
3396                 } else {
3397                         /* This fd should be FD_CLOEXEC already, but let's make sure. */
3398                         r = fd_cloexec(exec_fd, true);
3399                         if (r < 0) {
3400                                 *exit_status = EXIT_FDS;
3401                                 return log_unit_error_errno(unit, r, "Failed to make exec fd FD_CLOEXEC: %m");
3402                         }
3403                 }
3404
3405                 fds_with_exec_fd = newa(int, n_fds + 1);
3406                 memcpy_safe(fds_with_exec_fd, fds, n_fds * sizeof(int));
3407                 fds_with_exec_fd[n_fds] = exec_fd;
3408                 n_fds_with_exec_fd = n_fds + 1;
3409         } else {
3410                 fds_with_exec_fd = fds;
3411                 n_fds_with_exec_fd = n_fds;
3412         }
3413
3414         r = close_all_fds(fds_with_exec_fd, n_fds_with_exec_fd);
3415         if (r >= 0)
3416                 r = shift_fds(fds, n_fds);
3417         if (r >= 0)
3418                 r = flags_fds(fds, n_socket_fds, n_storage_fds, context->non_blocking);
3419         if (r < 0) {
3420                 *exit_status = EXIT_FDS;
3421                 return log_unit_error_errno(unit, r, "Failed to adjust passed file descriptors: %m");
3422         }
3423
3424         /* At this point, the fds we want to pass to the program are all ready and set up, with O_CLOEXEC turned off
3425          * and at the right fd numbers. The are no other fds open, with one exception: the exec_fd if it is defined,
3426          * and it has O_CLOEXEC set, after all we want it to be closed by the execve(), so that our parent knows we
3427          * came this far. */
3428
3429         secure_bits = context->secure_bits;
3430
3431         if (needs_sandboxing) {
3432                 uint64_t bset;
3433
3434                 /* Set the RTPRIO resource limit to 0, but only if nothing else was explicitly
3435                  * requested. (Note this is placed after the general resource limit initialization, see
3436                  * above, in order to take precedence.) */
3437                 if (context->restrict_realtime && !context->rlimit[RLIMIT_RTPRIO]) {
3438                         if (setrlimit(RLIMIT_RTPRIO, &RLIMIT_MAKE_CONST(0)) < 0) {
3439                                 *exit_status = EXIT_LIMITS;
3440                                 return log_unit_error_errno(unit, errno, "Failed to adjust RLIMIT_RTPRIO resource limit: %m");
3441                         }
3442                 }
3443
3444 #if ENABLE_SMACK
3445                 /* LSM Smack needs the capability CAP_MAC_ADMIN to change the current execution security context of the
3446                  * process. This is the latest place before dropping capabilities. Other MAC context are set later. */
3447                 if (use_smack) {
3448                         r = setup_smack(context, command);
3449                         if (r < 0) {
3450                                 *exit_status = EXIT_SMACK_PROCESS_LABEL;
3451                                 return log_unit_error_errno(unit, r, "Failed to set SMACK process label: %m");
3452                         }
3453                 }
3454 #endif
3455
3456                 bset = context->capability_bounding_set;
3457                 /* If the ambient caps hack is enabled (which means the kernel can't do them, and the user asked for
3458                  * our magic fallback), then let's add some extra caps, so that the service can drop privs of its own,
3459                  * instead of us doing that */
3460                 if (needs_ambient_hack)
3461                         bset |= (UINT64_C(1) << CAP_SETPCAP) |
3462                                 (UINT64_C(1) << CAP_SETUID) |
3463                                 (UINT64_C(1) << CAP_SETGID);
3464
3465                 if (!cap_test_all(bset)) {
3466                         r = capability_bounding_set_drop(bset, false);
3467                         if (r < 0) {
3468                                 *exit_status = EXIT_CAPABILITIES;
3469                                 return log_unit_error_errno(unit, r, "Failed to drop capabilities: %m");
3470                         }
3471                 }
3472
3473                 /* This is done before enforce_user, but ambient set
3474                  * does not survive over setresuid() if keep_caps is not set. */
3475                 if (!needs_ambient_hack &&
3476                     context->capability_ambient_set != 0) {
3477                         r = capability_ambient_set_apply(context->capability_ambient_set, true);
3478                         if (r < 0) {
3479                                 *exit_status = EXIT_CAPABILITIES;
3480                                 return log_unit_error_errno(unit, r, "Failed to apply ambient capabilities (before UID change): %m");
3481                         }
3482                 }
3483         }
3484
3485         if (needs_setuid) {
3486                 if (uid_is_valid(uid)) {
3487                         r = enforce_user(context, uid);
3488                         if (r < 0) {
3489                                 *exit_status = EXIT_USER;
3490                                 return log_unit_error_errno(unit, r, "Failed to change UID to " UID_FMT ": %m", uid);
3491                         }
3492
3493                         if (!needs_ambient_hack &&
3494                             context->capability_ambient_set != 0) {
3495
3496                                 /* Fix the ambient capabilities after user change. */
3497                                 r = capability_ambient_set_apply(context->capability_ambient_set, false);
3498                                 if (r < 0) {
3499                                         *exit_status = EXIT_CAPABILITIES;
3500                                         return log_unit_error_errno(unit, r, "Failed to apply ambient capabilities (after UID change): %m");
3501                                 }
3502
3503                                 /* If we were asked to change user and ambient capabilities
3504                                  * were requested, we had to add keep-caps to the securebits
3505                                  * so that we would maintain the inherited capability set
3506                                  * through the setresuid(). Make sure that the bit is added
3507                                  * also to the context secure_bits so that we don't try to
3508                                  * drop the bit away next. */
3509
3510                                 secure_bits |= 1<<SECURE_KEEP_CAPS;
3511                         }
3512                 }
3513         }
3514
3515         /* Apply working directory here, because the working directory might be on NFS and only the user running
3516          * this service might have the correct privilege to change to the working directory */
3517         r = apply_working_directory(context, params, home, needs_mount_namespace, exit_status);
3518         if (r < 0)
3519                 return log_unit_error_errno(unit, r, "Changing to the requested working directory failed: %m");
3520
3521         if (needs_sandboxing) {
3522                 /* Apply other MAC contexts late, but before seccomp syscall filtering, as those should really be last to
3523                  * influence our own codepaths as little as possible. Moreover, applying MAC contexts usually requires
3524                  * syscalls that are subject to seccomp filtering, hence should probably be applied before the syscalls
3525                  * are restricted. */
3526
3527 #if HAVE_SELINUX
3528                 if (use_selinux) {
3529                         char *exec_context = mac_selinux_context_net ?: context->selinux_context;
3530
3531                         if (exec_context) {
3532                                 r = setexeccon(exec_context);
3533                                 if (r < 0) {
3534                                         *exit_status = EXIT_SELINUX_CONTEXT;
3535                                         return log_unit_error_errno(unit, r, "Failed to change SELinux context to %s: %m", exec_context);
3536                                 }
3537                         }
3538                 }
3539 #endif
3540
3541 #if HAVE_APPARMOR
3542                 if (use_apparmor && context->apparmor_profile) {
3543                         r = aa_change_onexec(context->apparmor_profile);
3544                         if (r < 0 && !context->apparmor_profile_ignore) {
3545                                 *exit_status = EXIT_APPARMOR_PROFILE;
3546                                 return log_unit_error_errno(unit, errno, "Failed to prepare AppArmor profile change to %s: %m", context->apparmor_profile);
3547                         }
3548                 }
3549 #endif
3550
3551                 /* PR_GET_SECUREBITS is not privileged, while PR_SET_SECUREBITS is. So to suppress potential EPERMs
3552                  * we'll try not to call PR_SET_SECUREBITS unless necessary. */
3553                 if (prctl(PR_GET_SECUREBITS) != secure_bits)
3554                         if (prctl(PR_SET_SECUREBITS, secure_bits) < 0) {
3555                                 *exit_status = EXIT_SECUREBITS;
3556                                 return log_unit_error_errno(unit, errno, "Failed to set process secure bits: %m");
3557                         }
3558
3559                 if (context_has_no_new_privileges(context))
3560                         if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
3561                                 *exit_status = EXIT_NO_NEW_PRIVILEGES;
3562                                 return log_unit_error_errno(unit, errno, "Failed to disable new privileges: %m");
3563                         }
3564
3565 #if HAVE_SECCOMP
3566                 r = apply_address_families(unit, context);
3567                 if (r < 0) {
3568                         *exit_status = EXIT_ADDRESS_FAMILIES;
3569                         return log_unit_error_errno(unit, r, "Failed to restrict address families: %m");
3570                 }
3571
3572                 r = apply_memory_deny_write_execute(unit, context);
3573                 if (r < 0) {
3574                         *exit_status = EXIT_SECCOMP;
3575                         return log_unit_error_errno(unit, r, "Failed to disable writing to executable memory: %m");
3576                 }
3577
3578                 r = apply_restrict_realtime(unit, context);
3579                 if (r < 0) {
3580                         *exit_status = EXIT_SECCOMP;
3581                         return log_unit_error_errno(unit, r, "Failed to apply realtime restrictions: %m");
3582                 }
3583
3584                 r = apply_restrict_suid_sgid(unit, context);
3585                 if (r < 0) {
3586                         *exit_status = EXIT_SECCOMP;
3587                         return log_unit_error_errno(unit, r, "Failed to apply SUID/SGID restrictions: %m");
3588                 }
3589
3590                 r = apply_restrict_namespaces(unit, context);
3591                 if (r < 0) {
3592                         *exit_status = EXIT_SECCOMP;
3593                         return log_unit_error_errno(unit, r, "Failed to apply namespace restrictions: %m");
3594                 }
3595
3596                 r = apply_protect_sysctl(unit, context);
3597                 if (r < 0) {
3598                         *exit_status = EXIT_SECCOMP;
3599                         return log_unit_error_errno(unit, r, "Failed to apply sysctl restrictions: %m");
3600                 }
3601
3602                 r = apply_protect_kernel_modules(unit, context);
3603                 if (r < 0) {
3604                         *exit_status = EXIT_SECCOMP;
3605                         return log_unit_error_errno(unit, r, "Failed to apply module loading restrictions: %m");
3606                 }
3607
3608                 r = apply_private_devices(unit, context);
3609                 if (r < 0) {
3610                         *exit_status = EXIT_SECCOMP;
3611                         return log_unit_error_errno(unit, r, "Failed to set up private devices: %m");
3612                 }
3613
3614                 r = apply_syscall_archs(unit, context);
3615                 if (r < 0) {
3616                         *exit_status = EXIT_SECCOMP;
3617                         return log_unit_error_errno(unit, r, "Failed to apply syscall architecture restrictions: %m");
3618                 }
3619
3620                 r = apply_lock_personality(unit, context);
3621                 if (r < 0) {
3622                         *exit_status = EXIT_SECCOMP;
3623                         return log_unit_error_errno(unit, r, "Failed to lock personalities: %m");
3624                 }
3625
3626                 /* This really should remain the last step before the execve(), to make sure our own code is unaffected
3627                  * by the filter as little as possible. */
3628                 r = apply_syscall_filter(unit, context, needs_ambient_hack);
3629                 if (r < 0) {
3630                         *exit_status = EXIT_SECCOMP;
3631                         return log_unit_error_errno(unit, r, "Failed to apply system call filters: %m");
3632                 }
3633 #endif
3634         }
3635
3636         if (!strv_isempty(context->unset_environment)) {
3637                 char **ee = NULL;
3638
3639                 ee = strv_env_delete(accum_env, 1, context->unset_environment);
3640                 if (!ee) {
3641                         *exit_status = EXIT_MEMORY;
3642                         return log_oom();
3643                 }
3644
3645                 strv_free_and_replace(accum_env, ee);
3646         }
3647
3648         if (!FLAGS_SET(command->flags, EXEC_COMMAND_NO_ENV_EXPAND)) {
3649                 replaced_argv = replace_env_argv(command->argv, accum_env);
3650                 if (!replaced_argv) {
3651                         *exit_status = EXIT_MEMORY;
3652                         return log_oom();
3653                 }
3654                 final_argv = replaced_argv;
3655         } else
3656                 final_argv = command->argv;
3657
3658         if (DEBUG_LOGGING) {
3659                 _cleanup_free_ char *line;
3660
3661                 line = exec_command_line(final_argv);
3662                 if (line)
3663                         log_struct(LOG_DEBUG,
3664                                    "EXECUTABLE=%s", command->path,
3665                                    LOG_UNIT_MESSAGE(unit, "Executing: %s", line),
3666                                    LOG_UNIT_ID(unit),
3667                                    LOG_UNIT_INVOCATION_ID(unit));
3668         }
3669
3670         if (exec_fd >= 0) {
3671                 uint8_t hot = 1;
3672
3673                 /* We have finished with all our initializations. Let's now let the manager know that. From this point
3674                  * on, if the manager sees POLLHUP on the exec_fd, then execve() was successful. */
3675
3676                 if (write(exec_fd, &hot, sizeof(hot)) < 0) {
3677                         *exit_status = EXIT_EXEC;
3678                         return log_unit_error_errno(unit, errno, "Failed to enable exec_fd: %m");
3679                 }
3680         }
3681
3682         execve(command->path, final_argv, accum_env);
3683         r = -errno;
3684
3685         if (exec_fd >= 0) {
3686                 uint8_t hot = 0;
3687
3688                 /* The execve() failed. This means the exec_fd is still open. Which means we need to tell the manager
3689                  * that POLLHUP on it no longer means execve() succeeded. */
3690
3691                 if (write(exec_fd, &hot, sizeof(hot)) < 0) {
3692                         *exit_status = EXIT_EXEC;
3693                         return log_unit_error_errno(unit, errno, "Failed to disable exec_fd: %m");
3694                 }
3695         }
3696
3697         if (r == -ENOENT && (command->flags & EXEC_COMMAND_IGNORE_FAILURE)) {
3698                 log_struct_errno(LOG_INFO, r,
3699                                  "MESSAGE_ID=" SD_MESSAGE_SPAWN_FAILED_STR,
3700                                  LOG_UNIT_ID(unit),
3701                                  LOG_UNIT_INVOCATION_ID(unit),
3702                                  LOG_UNIT_MESSAGE(unit, "Executable %s missing, skipping: %m",
3703                                                   command->path),
3704                                  "EXECUTABLE=%s", command->path);
3705                 return 0;
3706         }
3707
3708         *exit_status = EXIT_EXEC;
3709         return log_unit_error_errno(unit, r, "Failed to execute command: %m");
3710 }
3711
3712 static int exec_context_load_environment(const Unit *unit, const ExecContext *c, char ***l);
3713 static int exec_context_named_iofds(const ExecContext *c, const ExecParameters *p, int named_iofds[3]);
3714
3715 int exec_spawn(Unit *unit,
3716                ExecCommand *command,
3717                const ExecContext *context,
3718                const ExecParameters *params,
3719                ExecRuntime *runtime,
3720                DynamicCreds *dcreds,
3721                pid_t *ret) {
3722
3723         int socket_fd, r, named_iofds[3] = { -1, -1, -1 }, *fds = NULL;
3724         _cleanup_free_ char *subcgroup_path = NULL;
3725         _cleanup_strv_free_ char **files_env = NULL;
3726         size_t n_storage_fds = 0, n_socket_fds = 0;
3727         _cleanup_free_ char *line = NULL;
3728         pid_t pid;
3729
3730         assert(unit);
3731         assert(command);
3732         assert(context);
3733         assert(ret);
3734         assert(params);
3735         assert(params->fds || (params->n_socket_fds + params->n_storage_fds <= 0));
3736
3737         if (context->std_input == EXEC_INPUT_SOCKET ||
3738             context->std_output == EXEC_OUTPUT_SOCKET ||
3739             context->std_error == EXEC_OUTPUT_SOCKET) {
3740
3741                 if (params->n_socket_fds > 1) {
3742                         log_unit_error(unit, "Got more than one socket.");
3743                         return -EINVAL;
3744                 }
3745
3746                 if (params->n_socket_fds == 0) {
3747                         log_unit_error(unit, "Got no socket.");
3748                         return -EINVAL;
3749                 }
3750
3751                 socket_fd = params->fds[0];
3752         } else {
3753                 socket_fd = -1;
3754                 fds = params->fds;
3755                 n_socket_fds = params->n_socket_fds;
3756                 n_storage_fds = params->n_storage_fds;
3757         }
3758
3759         r = exec_context_named_iofds(context, params, named_iofds);
3760         if (r < 0)
3761                 return log_unit_error_errno(unit, r, "Failed to load a named file descriptor: %m");
3762
3763         r = exec_context_load_environment(unit, context, &files_env);
3764         if (r < 0)
3765                 return log_unit_error_errno(unit, r, "Failed to load environment files: %m");
3766
3767         line = exec_command_line(command->argv);
3768         if (!line)
3769                 return log_oom();
3770
3771         log_struct(LOG_DEBUG,
3772                    LOG_UNIT_MESSAGE(unit, "About to execute: %s", line),
3773                    "EXECUTABLE=%s", command->path,
3774                    LOG_UNIT_ID(unit),
3775                    LOG_UNIT_INVOCATION_ID(unit));
3776
3777         if (params->cgroup_path) {
3778                 r = exec_parameters_get_cgroup_path(params, &subcgroup_path);
3779                 if (r < 0)
3780                         return log_unit_error_errno(unit, r, "Failed to acquire subcgroup path: %m");
3781                 if (r > 0) { /* We are using a child cgroup */
3782                         r = cg_create(SYSTEMD_CGROUP_CONTROLLER, subcgroup_path);
3783                         if (r < 0)
3784                                 return log_unit_error_errno(unit, r, "Failed to create control group '%s': %m", subcgroup_path);
3785                 }
3786         }
3787
3788         pid = fork();
3789         if (pid < 0)
3790                 return log_unit_error_errno(unit, errno, "Failed to fork: %m");
3791
3792         if (pid == 0) {
3793                 int exit_status = EXIT_SUCCESS;
3794
3795                 r = exec_child(unit,
3796                                command,
3797                                context,
3798                                params,
3799                                runtime,
3800                                dcreds,
3801                                socket_fd,
3802                                named_iofds,
3803                                fds,
3804                                n_socket_fds,
3805                                n_storage_fds,
3806                                files_env,
3807                                unit->manager->user_lookup_fds[1],
3808                                &exit_status);
3809
3810                 if (r < 0)
3811                         log_struct_errno(LOG_ERR, r,
3812                                          "MESSAGE_ID=" SD_MESSAGE_SPAWN_FAILED_STR,
3813                                          LOG_UNIT_ID(unit),
3814                                          LOG_UNIT_INVOCATION_ID(unit),
3815                                          LOG_UNIT_MESSAGE(unit, "Failed at step %s spawning %s: %m",
3816                                                           exit_status_to_string(exit_status, EXIT_STATUS_SYSTEMD),
3817                                                           command->path),
3818                                          "EXECUTABLE=%s", command->path);
3819
3820                 _exit(exit_status);
3821         }
3822
3823         log_unit_debug(unit, "Forked %s as "PID_FMT, command->path, pid);
3824
3825         /* We add the new process to the cgroup both in the child (so that we can be sure that no user code is ever
3826          * executed outside of the cgroup) and in the parent (so that we can be sure that when we kill the cgroup the
3827          * process will be killed too). */
3828         if (subcgroup_path)
3829                 (void) cg_attach(SYSTEMD_CGROUP_CONTROLLER, subcgroup_path, pid);
3830
3831         exec_status_start(&command->exec_status, pid);
3832
3833         *ret = pid;
3834         return 0;
3835 }
3836
3837 void exec_context_init(ExecContext *c) {
3838         ExecDirectoryType i;
3839
3840         assert(c);
3841
3842         c->umask = 0022;
3843         c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);
3844         c->cpu_sched_policy = SCHED_OTHER;
3845         c->syslog_priority = LOG_DAEMON|LOG_INFO;
3846         c->syslog_level_prefix = true;
3847         c->ignore_sigpipe = true;
3848         c->timer_slack_nsec = NSEC_INFINITY;
3849         c->personality = PERSONALITY_INVALID;
3850         for (i = 0; i < _EXEC_DIRECTORY_TYPE_MAX; i++)
3851                 c->directories[i].mode = 0755;
3852         c->capability_bounding_set = CAP_ALL;
3853         assert_cc(NAMESPACE_FLAGS_INITIAL != NAMESPACE_FLAGS_ALL);
3854         c->restrict_namespaces = NAMESPACE_FLAGS_INITIAL;
3855         c->log_level_max = -1;
3856 }
3857
3858 void exec_context_done(ExecContext *c) {
3859         ExecDirectoryType i;
3860         size_t l;
3861
3862         assert(c);
3863
3864         c->environment = strv_free(c->environment);
3865         c->environment_files = strv_free(c->environment_files);
3866         c->pass_environment = strv_free(c->pass_environment);
3867         c->unset_environment = strv_free(c->unset_environment);
3868
3869         rlimit_free_all(c->rlimit);
3870
3871         for (l = 0; l < 3; l++) {
3872                 c->stdio_fdname[l] = mfree(c->stdio_fdname[l]);
3873                 c->stdio_file[l] = mfree(c->stdio_file[l]);
3874         }
3875
3876         c->working_directory = mfree(c->working_directory);
3877         c->root_directory = mfree(c->root_directory);
3878         c->root_image = mfree(c->root_image);
3879         c->tty_path = mfree(c->tty_path);
3880         c->syslog_identifier = mfree(c->syslog_identifier);
3881         c->user = mfree(c->user);
3882         c->group = mfree(c->group);
3883
3884         c->supplementary_groups = strv_free(c->supplementary_groups);
3885
3886         c->pam_name = mfree(c->pam_name);
3887
3888         c->read_only_paths = strv_free(c->read_only_paths);
3889         c->read_write_paths = strv_free(c->read_write_paths);
3890         c->inaccessible_paths = strv_free(c->inaccessible_paths);
3891
3892         bind_mount_free_many(c->bind_mounts, c->n_bind_mounts);
3893         c->bind_mounts = NULL;
3894         c->n_bind_mounts = 0;
3895         temporary_filesystem_free_many(c->temporary_filesystems, c->n_temporary_filesystems);
3896         c->temporary_filesystems = NULL;
3897         c->n_temporary_filesystems = 0;
3898
3899         cpu_set_reset(&c->cpu_set);
3900
3901         c->utmp_id = mfree(c->utmp_id);
3902         c->selinux_context = mfree(c->selinux_context);
3903         c->apparmor_profile = mfree(c->apparmor_profile);
3904         c->smack_process_label = mfree(c->smack_process_label);
3905
3906         c->syscall_filter = hashmap_free(c->syscall_filter);
3907         c->syscall_archs = set_free(c->syscall_archs);
3908         c->address_families = set_free(c->address_families);
3909
3910         for (i = 0; i < _EXEC_DIRECTORY_TYPE_MAX; i++)
3911                 c->directories[i].paths = strv_free(c->directories[i].paths);
3912
3913         c->log_level_max = -1;
3914
3915         exec_context_free_log_extra_fields(c);
3916
3917         c->log_rate_limit_interval_usec = 0;
3918         c->log_rate_limit_burst = 0;
3919
3920         c->stdin_data = mfree(c->stdin_data);
3921         c->stdin_data_size = 0;
3922
3923         c->network_namespace_path = mfree(c->network_namespace_path);
3924 }
3925
3926 int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_prefix) {
3927         char **i;
3928
3929         assert(c);
3930
3931         if (!runtime_prefix)
3932                 return 0;
3933
3934         STRV_FOREACH(i, c->directories[EXEC_DIRECTORY_RUNTIME].paths) {
3935                 _cleanup_free_ char *p;
3936
3937                 p = path_join(runtime_prefix, *i);
3938                 if (!p)
3939                         return -ENOMEM;
3940
3941                 /* We execute this synchronously, since we need to be sure this is gone when we start the
3942                  * service next. */
3943                 (void) rm_rf(p, REMOVE_ROOT);
3944         }
3945
3946         return 0;
3947 }
3948
3949 static void exec_command_done(ExecCommand *c) {
3950         assert(c);
3951
3952         c->path = mfree(c->path);
3953         c->argv = strv_free(c->argv);
3954 }
3955
3956 void exec_command_done_array(ExecCommand *c, size_t n) {
3957         size_t i;
3958
3959         for (i = 0; i < n; i++)
3960                 exec_command_done(c+i);
3961 }
3962
3963 ExecCommand* exec_command_free_list(ExecCommand *c) {
3964         ExecCommand *i;
3965
3966         while ((i = c)) {
3967                 LIST_REMOVE(command, c, i);
3968                 exec_command_done(i);
3969                 free(i);
3970         }
3971
3972         return NULL;
3973 }
3974
3975 void exec_command_free_array(ExecCommand **c, size_t n) {
3976         size_t i;
3977
3978         for (i = 0; i < n; i++)
3979                 c[i] = exec_command_free_list(c[i]);
3980 }
3981
3982 void exec_command_reset_status_array(ExecCommand *c, size_t n) {
3983         size_t i;
3984
3985         for (i = 0; i < n; i++)
3986                 exec_status_reset(&c[i].exec_status);
3987 }
3988
3989 void exec_command_reset_status_list_array(ExecCommand **c, size_t n) {
3990         size_t i;
3991
3992         for (i = 0; i < n; i++) {
3993                 ExecCommand *z;
3994
3995                 LIST_FOREACH(command, z, c[i])
3996                         exec_status_reset(&z->exec_status);
3997         }
3998 }
3999
4000 typedef struct InvalidEnvInfo {
4001         const Unit *unit;
4002         const char *path;
4003 } InvalidEnvInfo;
4004
4005 static void invalid_env(const char *p, void *userdata) {
4006         InvalidEnvInfo *info = userdata;
4007
4008         log_unit_error(info->unit, "Ignoring invalid environment assignment '%s': %s", p, info->path);
4009 }
4010
4011 const char* exec_context_fdname(const ExecContext *c, int fd_index) {
4012         assert(c);
4013
4014         switch (fd_index) {
4015
4016         case STDIN_FILENO:
4017                 if (c->std_input != EXEC_INPUT_NAMED_FD)
4018                         return NULL;
4019
4020                 return c->stdio_fdname[STDIN_FILENO] ?: "stdin";
4021
4022         case STDOUT_FILENO:
4023                 if (c->std_output != EXEC_OUTPUT_NAMED_FD)
4024                         return NULL;
4025
4026                 return c->stdio_fdname[STDOUT_FILENO] ?: "stdout";
4027
4028         case STDERR_FILENO:
4029                 if (c->std_error != EXEC_OUTPUT_NAMED_FD)
4030                         return NULL;
4031
4032                 return c->stdio_fdname[STDERR_FILENO] ?: "stderr";
4033
4034         default:
4035                 return NULL;
4036         }
4037 }
4038
4039 static int exec_context_named_iofds(const ExecContext *c, const ExecParameters *p, int named_iofds[static 3]) {
4040         size_t i, targets;
4041         const char* stdio_fdname[3];
4042         size_t n_fds;
4043
4044         assert(c);
4045         assert(p);
4046
4047         targets = (c->std_input == EXEC_INPUT_NAMED_FD) +
4048                   (c->std_output == EXEC_OUTPUT_NAMED_FD) +
4049                   (c->std_error == EXEC_OUTPUT_NAMED_FD);
4050
4051         for (i = 0; i < 3; i++)
4052                 stdio_fdname[i] = exec_context_fdname(c, i);
4053
4054         n_fds = p->n_storage_fds + p->n_socket_fds;
4055
4056         for (i = 0; i < n_fds  && targets > 0; i++)
4057                 if (named_iofds[STDIN_FILENO] < 0 &&
4058                     c->std_input == EXEC_INPUT_NAMED_FD &&
4059                     stdio_fdname[STDIN_FILENO] &&
4060                     streq(p->fd_names[i], stdio_fdname[STDIN_FILENO])) {
4061
4062                         named_iofds[STDIN_FILENO] = p->fds[i];
4063                         targets--;
4064
4065                 } else if (named_iofds[STDOUT_FILENO] < 0 &&
4066                            c->std_output == EXEC_OUTPUT_NAMED_FD &&
4067                            stdio_fdname[STDOUT_FILENO] &&
4068                            streq(p->fd_names[i], stdio_fdname[STDOUT_FILENO])) {
4069
4070                         named_iofds[STDOUT_FILENO] = p->fds[i];
4071                         targets--;
4072
4073                 } else if (named_iofds[STDERR_FILENO] < 0 &&
4074                            c->std_error == EXEC_OUTPUT_NAMED_FD &&
4075                            stdio_fdname[STDERR_FILENO] &&
4076                            streq(p->fd_names[i], stdio_fdname[STDERR_FILENO])) {
4077
4078                         named_iofds[STDERR_FILENO] = p->fds[i];
4079                         targets--;
4080                 }
4081
4082         return targets == 0 ? 0 : -ENOENT;
4083 }
4084
4085 static int exec_context_load_environment(const Unit *unit, const ExecContext *c, char ***l) {
4086         char **i, **r = NULL;
4087
4088         assert(c);
4089         assert(l);
4090
4091         STRV_FOREACH(i, c->environment_files) {
4092                 char *fn;
4093                 int k;
4094                 unsigned n;
4095                 bool ignore = false;
4096                 char **p;
4097                 _cleanup_globfree_ glob_t pglob = {};
4098
4099                 fn = *i;
4100
4101                 if (fn[0] == '-') {
4102                         ignore = true;
4103                         fn++;
4104                 }
4105
4106                 if (!path_is_absolute(fn)) {
4107                         if (ignore)
4108                                 continue;
4109
4110                         strv_free(r);
4111                         return -EINVAL;
4112                 }
4113
4114                 /* Filename supports globbing, take all matching files */
4115                 k = safe_glob(fn, 0, &pglob);
4116                 if (k < 0) {
4117                         if (ignore)
4118                                 continue;
4119
4120                         strv_free(r);
4121                         return k;
4122                 }
4123
4124                 /* When we don't match anything, -ENOENT should be returned */
4125                 assert(pglob.gl_pathc > 0);
4126
4127                 for (n = 0; n < pglob.gl_pathc; n++) {
4128                         k = load_env_file(NULL, pglob.gl_pathv[n], &p);
4129                         if (k < 0) {
4130                                 if (ignore)
4131                                         continue;
4132
4133                                 strv_free(r);
4134                                 return k;
4135                         }
4136                         /* Log invalid environment variables with filename */
4137                         if (p) {
4138                                 InvalidEnvInfo info = {
4139                                         .unit = unit,
4140                                         .path = pglob.gl_pathv[n]
4141                                 };
4142
4143                                 p = strv_env_clean_with_callback(p, invalid_env, &info);
4144                         }
4145
4146                         if (!r)
4147                                 r = p;
4148                         else {
4149                                 char **m;
4150
4151                                 m = strv_env_merge(2, r, p);
4152                                 strv_free(r);
4153                                 strv_free(p);
4154                                 if (!m)
4155                                         return -ENOMEM;
4156
4157                                 r = m;
4158                         }
4159                 }
4160         }
4161
4162         *l = r;
4163
4164         return 0;
4165 }
4166
4167 static bool tty_may_match_dev_console(const char *tty) {
4168         _cleanup_free_ char *resolved = NULL;
4169
4170         if (!tty)
4171                 return true;
4172
4173         tty = skip_dev_prefix(tty);
4174
4175         /* trivial identity? */
4176         if (streq(tty, "console"))
4177                 return true;
4178
4179         if (resolve_dev_console(&resolved) < 0)
4180                 return true; /* if we could not resolve, assume it may */
4181
4182         /* "tty0" means the active VC, so it may be the same sometimes */
4183         return path_equal(resolved, tty) || (streq(resolved, "tty0") && tty_is_vc(tty));
4184 }
4185
4186 static bool exec_context_may_touch_tty(const ExecContext *ec) {
4187         assert(ec);
4188
4189         return ec->tty_reset ||
4190                 ec->tty_vhangup ||
4191                 ec->tty_vt_disallocate ||
4192                 is_terminal_input(ec->std_input) ||
4193                 is_terminal_output(ec->std_output) ||
4194                 is_terminal_output(ec->std_error);
4195 }
4196
4197 bool exec_context_may_touch_console(const ExecContext *ec) {
4198
4199         return exec_context_may_touch_tty(ec) &&
4200                tty_may_match_dev_console(exec_context_tty_path(ec));
4201 }
4202
4203 static void strv_fprintf(FILE *f, char **l) {
4204         char **g;
4205
4206         assert(f);
4207
4208         STRV_FOREACH(g, l)
4209                 fprintf(f, " %s", *g);
4210 }
4211
4212 void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix) {
4213         ExecDirectoryType dt;
4214         char **e, **d;
4215         unsigned i;
4216         int r;
4217
4218         assert(c);
4219         assert(f);
4220
4221         prefix = strempty(prefix);
4222
4223         fprintf(f,
4224                 "%sUMask: %04o\n"
4225                 "%sWorkingDirectory: %s\n"
4226                 "%sRootDirectory: %s\n"
4227                 "%sNonBlocking: %s\n"
4228                 "%sPrivateTmp: %s\n"
4229                 "%sPrivateDevices: %s\n"
4230                 "%sProtectKernelTunables: %s\n"
4231                 "%sProtectKernelModules: %s\n"
4232                 "%sProtectControlGroups: %s\n"
4233                 "%sPrivateNetwork: %s\n"
4234                 "%sPrivateUsers: %s\n"
4235                 "%sProtectHome: %s\n"
4236                 "%sProtectSystem: %s\n"
4237                 "%sMountAPIVFS: %s\n"
4238                 "%sIgnoreSIGPIPE: %s\n"
4239                 "%sMemoryDenyWriteExecute: %s\n"
4240                 "%sRestrictRealtime: %s\n"
4241                 "%sRestrictSUIDSGID: %s\n"
4242                 "%sKeyringMode: %s\n"
4243                 "%sProtectHostname: %s\n",
4244                 prefix, c->umask,
4245                 prefix, c->working_directory ? c->working_directory : "/",
4246                 prefix, c->root_directory ? c->root_directory : "/",
4247                 prefix, yes_no(c->non_blocking),
4248                 prefix, yes_no(c->private_tmp),
4249                 prefix, yes_no(c->private_devices),
4250                 prefix, yes_no(c->protect_kernel_tunables),
4251                 prefix, yes_no(c->protect_kernel_modules),
4252                 prefix, yes_no(c->protect_control_groups),
4253                 prefix, yes_no(c->private_network),
4254                 prefix, yes_no(c->private_users),
4255                 prefix, protect_home_to_string(c->protect_home),
4256                 prefix, protect_system_to_string(c->protect_system),
4257                 prefix, yes_no(c->mount_apivfs),
4258                 prefix, yes_no(c->ignore_sigpipe),
4259                 prefix, yes_no(c->memory_deny_write_execute),
4260                 prefix, yes_no(c->restrict_realtime),
4261                 prefix, yes_no(c->restrict_suid_sgid),
4262                 prefix, exec_keyring_mode_to_string(c->keyring_mode),
4263                 prefix, yes_no(c->protect_hostname));
4264
4265         if (c->root_image)
4266                 fprintf(f, "%sRootImage: %s\n", prefix, c->root_image);
4267
4268         STRV_FOREACH(e, c->environment)
4269                 fprintf(f, "%sEnvironment: %s\n", prefix, *e);
4270
4271         STRV_FOREACH(e, c->environment_files)
4272                 fprintf(f, "%sEnvironmentFile: %s\n", prefix, *e);
4273
4274         STRV_FOREACH(e, c->pass_environment)
4275                 fprintf(f, "%sPassEnvironment: %s\n", prefix, *e);
4276
4277         STRV_FOREACH(e, c->unset_environment)
4278                 fprintf(f, "%sUnsetEnvironment: %s\n", prefix, *e);
4279
4280         fprintf(f, "%sRuntimeDirectoryPreserve: %s\n", prefix, exec_preserve_mode_to_string(c->runtime_directory_preserve_mode));
4281
4282         for (dt = 0; dt < _EXEC_DIRECTORY_TYPE_MAX; dt++) {
4283                 fprintf(f, "%s%sMode: %04o\n", prefix, exec_directory_type_to_string(dt), c->directories[dt].mode);
4284
4285                 STRV_FOREACH(d, c->directories[dt].paths)
4286                         fprintf(f, "%s%s: %s\n", prefix, exec_directory_type_to_string(dt), *d);
4287         }
4288
4289         if (c->nice_set)
4290                 fprintf(f,
4291                         "%sNice: %i\n",
4292                         prefix, c->nice);
4293
4294         if (c->oom_score_adjust_set)
4295                 fprintf(f,
4296                         "%sOOMScoreAdjust: %i\n",
4297                         prefix, c->oom_score_adjust);
4298
4299         for (i = 0; i < RLIM_NLIMITS; i++)
4300                 if (c->rlimit[i]) {
4301                         fprintf(f, "%sLimit%s: " RLIM_FMT "\n",
4302                                 prefix, rlimit_to_string(i), c->rlimit[i]->rlim_max);
4303                         fprintf(f, "%sLimit%sSoft: " RLIM_FMT "\n",
4304                                 prefix, rlimit_to_string(i), c->rlimit[i]->rlim_cur);
4305                 }
4306
4307         if (c->ioprio_set) {
4308                 _cleanup_free_ char *class_str = NULL;
4309
4310                 r = ioprio_class_to_string_alloc(IOPRIO_PRIO_CLASS(c->ioprio), &class_str);
4311                 if (r >= 0)
4312                         fprintf(f, "%sIOSchedulingClass: %s\n", prefix, class_str);
4313
4314                 fprintf(f, "%sIOPriority: %lu\n", prefix, IOPRIO_PRIO_DATA(c->ioprio));
4315         }
4316
4317         if (c->cpu_sched_set) {
4318                 _cleanup_free_ char *policy_str = NULL;
4319
4320                 r = sched_policy_to_string_alloc(c->cpu_sched_policy, &policy_str);
4321                 if (r >= 0)
4322                         fprintf(f, "%sCPUSchedulingPolicy: %s\n", prefix, policy_str);
4323
4324                 fprintf(f,
4325                         "%sCPUSchedulingPriority: %i\n"
4326                         "%sCPUSchedulingResetOnFork: %s\n",
4327                         prefix, c->cpu_sched_priority,
4328                         prefix, yes_no(c->cpu_sched_reset_on_fork));
4329         }
4330
4331         if (c->cpu_set.set) {
4332                 fprintf(f, "%sCPUAffinity:", prefix);
4333                 for (i = 0; i < c->cpu_set.allocated * 8; i++)
4334                         if (CPU_ISSET_S(i, c->cpu_set.allocated, c->cpu_set.set))
4335                                 fprintf(f, " %u", i);
4336                 fputs("\n", f);
4337         }
4338
4339         if (c->timer_slack_nsec != NSEC_INFINITY)
4340                 fprintf(f, "%sTimerSlackNSec: "NSEC_FMT "\n", prefix, c->timer_slack_nsec);
4341
4342         fprintf(f,
4343                 "%sStandardInput: %s\n"
4344                 "%sStandardOutput: %s\n"
4345                 "%sStandardError: %s\n",
4346                 prefix, exec_input_to_string(c->std_input),
4347                 prefix, exec_output_to_string(c->std_output),
4348                 prefix, exec_output_to_string(c->std_error));
4349
4350         if (c->std_input == EXEC_INPUT_NAMED_FD)
4351                 fprintf(f, "%sStandardInputFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDIN_FILENO]);
4352         if (c->std_output == EXEC_OUTPUT_NAMED_FD)
4353                 fprintf(f, "%sStandardOutputFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDOUT_FILENO]);
4354         if (c->std_error == EXEC_OUTPUT_NAMED_FD)
4355                 fprintf(f, "%sStandardErrorFileDescriptorName: %s\n", prefix, c->stdio_fdname[STDERR_FILENO]);
4356
4357         if (c->std_input == EXEC_INPUT_FILE)
4358                 fprintf(f, "%sStandardInputFile: %s\n", prefix, c->stdio_file[STDIN_FILENO]);
4359         if (c->std_output == EXEC_OUTPUT_FILE)
4360                 fprintf(f, "%sStandardOutputFile: %s\n", prefix, c->stdio_file[STDOUT_FILENO]);
4361         if (c->std_output == EXEC_OUTPUT_FILE_APPEND)
4362                 fprintf(f, "%sStandardOutputFileToAppend: %s\n", prefix, c->stdio_file[STDOUT_FILENO]);
4363         if (c->std_error == EXEC_OUTPUT_FILE)
4364                 fprintf(f, "%sStandardErrorFile: %s\n", prefix, c->stdio_file[STDERR_FILENO]);
4365         if (c->std_error == EXEC_OUTPUT_FILE_APPEND)
4366                 fprintf(f, "%sStandardErrorFileToAppend: %s\n", prefix, c->stdio_file[STDERR_FILENO]);
4367
4368         if (c->tty_path)
4369                 fprintf(f,
4370                         "%sTTYPath: %s\n"
4371                         "%sTTYReset: %s\n"
4372                         "%sTTYVHangup: %s\n"
4373                         "%sTTYVTDisallocate: %s\n",
4374                         prefix, c->tty_path,
4375                         prefix, yes_no(c->tty_reset),
4376                         prefix, yes_no(c->tty_vhangup),
4377                         prefix, yes_no(c->tty_vt_disallocate));
4378
4379         if (IN_SET(c->std_output,
4380                    EXEC_OUTPUT_SYSLOG,
4381                    EXEC_OUTPUT_KMSG,
4382                    EXEC_OUTPUT_JOURNAL,
4383                    EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
4384                    EXEC_OUTPUT_KMSG_AND_CONSOLE,
4385                    EXEC_OUTPUT_JOURNAL_AND_CONSOLE) ||
4386             IN_SET(c->std_error,
4387                    EXEC_OUTPUT_SYSLOG,
4388                    EXEC_OUTPUT_KMSG,
4389                    EXEC_OUTPUT_JOURNAL,
4390                    EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
4391                    EXEC_OUTPUT_KMSG_AND_CONSOLE,
4392                    EXEC_OUTPUT_JOURNAL_AND_CONSOLE)) {
4393
4394                 _cleanup_free_ char *fac_str = NULL, *lvl_str = NULL;
4395
4396                 r = log_facility_unshifted_to_string_alloc(c->syslog_priority >> 3, &fac_str);
4397                 if (r >= 0)
4398                         fprintf(f, "%sSyslogFacility: %s\n", prefix, fac_str);
4399
4400                 r = log_level_to_string_alloc(LOG_PRI(c->syslog_priority), &lvl_str);
4401                 if (r >= 0)
4402                         fprintf(f, "%sSyslogLevel: %s\n", prefix, lvl_str);
4403         }
4404
4405         if (c->log_level_max >= 0) {
4406                 _cleanup_free_ char *t = NULL;
4407
4408                 (void) log_level_to_string_alloc(c->log_level_max, &t);
4409
4410                 fprintf(f, "%sLogLevelMax: %s\n", prefix, strna(t));
4411         }
4412
4413         if (c->log_rate_limit_interval_usec > 0) {
4414                 char buf_timespan[FORMAT_TIMESPAN_MAX];
4415
4416                 fprintf(f,
4417                         "%sLogRateLimitIntervalSec: %s\n",
4418                         prefix, format_timespan(buf_timespan, sizeof(buf_timespan), c->log_rate_limit_interval_usec, USEC_PER_SEC));
4419         }
4420
4421         if (c->log_rate_limit_burst > 0)
4422                 fprintf(f, "%sLogRateLimitBurst: %u\n", prefix, c->log_rate_limit_burst);
4423
4424         if (c->n_log_extra_fields > 0) {
4425                 size_t j;
4426
4427                 for (j = 0; j < c->n_log_extra_fields; j++) {
4428                         fprintf(f, "%sLogExtraFields: ", prefix);
4429                         fwrite(c->log_extra_fields[j].iov_base,
4430                                1, c->log_extra_fields[j].iov_len,
4431                                f);
4432                         fputc('\n', f);
4433                 }
4434         }
4435
4436         if (c->secure_bits) {
4437                 _cleanup_free_ char *str = NULL;
4438
4439                 r = secure_bits_to_string_alloc(c->secure_bits, &str);
4440                 if (r >= 0)
4441                         fprintf(f, "%sSecure Bits: %s\n", prefix, str);
4442         }
4443
4444         if (c->capability_bounding_set != CAP_ALL) {
4445                 _cleanup_free_ char *str = NULL;
4446
4447                 r = capability_set_to_string_alloc(c->capability_bounding_set, &str);
4448                 if (r >= 0)
4449                         fprintf(f, "%sCapabilityBoundingSet: %s\n", prefix, str);
4450         }
4451
4452         if (c->capability_ambient_set != 0) {
4453                 _cleanup_free_ char *str = NULL;
4454
4455                 r = capability_set_to_string_alloc(c->capability_ambient_set, &str);
4456                 if (r >= 0)
4457                         fprintf(f, "%sAmbientCapabilities: %s\n", prefix, str);
4458         }
4459
4460         if (c->user)
4461                 fprintf(f, "%sUser: %s\n", prefix, c->user);
4462         if (c->group)
4463                 fprintf(f, "%sGroup: %s\n", prefix, c->group);
4464
4465         fprintf(f, "%sDynamicUser: %s\n", prefix, yes_no(c->dynamic_user));
4466
4467         if (!strv_isempty(c->supplementary_groups)) {
4468                 fprintf(f, "%sSupplementaryGroups:", prefix);
4469                 strv_fprintf(f, c->supplementary_groups);
4470                 fputs("\n", f);
4471         }
4472
4473         if (c->pam_name)
4474                 fprintf(f, "%sPAMName: %s\n", prefix, c->pam_name);
4475
4476         if (!strv_isempty(c->read_write_paths)) {
4477                 fprintf(f, "%sReadWritePaths:", prefix);
4478                 strv_fprintf(f, c->read_write_paths);
4479                 fputs("\n", f);
4480         }
4481
4482         if (!strv_isempty(c->read_only_paths)) {
4483                 fprintf(f, "%sReadOnlyPaths:", prefix);
4484                 strv_fprintf(f, c->read_only_paths);
4485                 fputs("\n", f);
4486         }
4487
4488         if (!strv_isempty(c->inaccessible_paths)) {
4489                 fprintf(f, "%sInaccessiblePaths:", prefix);
4490                 strv_fprintf(f, c->inaccessible_paths);
4491                 fputs("\n", f);
4492         }
4493
4494         if (c->n_bind_mounts > 0)
4495                 for (i = 0; i < c->n_bind_mounts; i++)
4496                         fprintf(f, "%s%s: %s%s:%s:%s\n", prefix,
4497                                 c->bind_mounts[i].read_only ? "BindReadOnlyPaths" : "BindPaths",
4498                                 c->bind_mounts[i].ignore_enoent ? "-": "",
4499                                 c->bind_mounts[i].source,
4500                                 c->bind_mounts[i].destination,
4501                                 c->bind_mounts[i].recursive ? "rbind" : "norbind");
4502
4503         if (c->n_temporary_filesystems > 0)
4504                 for (i = 0; i < c->n_temporary_filesystems; i++) {
4505                         TemporaryFileSystem *t = c->temporary_filesystems + i;
4506
4507                         fprintf(f, "%sTemporaryFileSystem: %s%s%s\n", prefix,
4508                                 t->path,
4509                                 isempty(t->options) ? "" : ":",
4510                                 strempty(t->options));
4511                 }
4512
4513         if (c->utmp_id)
4514                 fprintf(f,
4515                         "%sUtmpIdentifier: %s\n",
4516                         prefix, c->utmp_id);
4517
4518         if (c->selinux_context)
4519                 fprintf(f,
4520                         "%sSELinuxContext: %s%s\n",
4521                         prefix, c->selinux_context_ignore ? "-" : "", c->selinux_context);
4522
4523         if (c->apparmor_profile)
4524                 fprintf(f,
4525                         "%sAppArmorProfile: %s%s\n",
4526                         prefix, c->apparmor_profile_ignore ? "-" : "", c->apparmor_profile);
4527
4528         if (c->smack_process_label)
4529                 fprintf(f,
4530                         "%sSmackProcessLabel: %s%s\n",
4531                         prefix, c->smack_process_label_ignore ? "-" : "", c->smack_process_label);
4532
4533         if (c->personality != PERSONALITY_INVALID)
4534                 fprintf(f,
4535                         "%sPersonality: %s\n",
4536                         prefix, strna(personality_to_string(c->personality)));
4537
4538         fprintf(f,
4539                 "%sLockPersonality: %s\n",
4540                 prefix, yes_no(c->lock_personality));
4541
4542         if (c->syscall_filter) {
4543 #if HAVE_SECCOMP
4544                 Iterator j;
4545                 void *id, *val;
4546                 bool first = true;
4547 #endif
4548
4549                 fprintf(f,
4550                         "%sSystemCallFilter: ",
4551                         prefix);
4552
4553                 if (!c->syscall_whitelist)
4554                         fputc('~', f);
4555
4556 #if HAVE_SECCOMP
4557                 HASHMAP_FOREACH_KEY(val, id, c->syscall_filter, j) {
4558                         _cleanup_free_ char *name = NULL;
4559                         const char *errno_name = NULL;
4560                         int num = PTR_TO_INT(val);
4561
4562                         if (first)
4563                                 first = false;
4564                         else
4565                                 fputc(' ', f);
4566
4567                         name = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE, PTR_TO_INT(id) - 1);
4568                         fputs(strna(name), f);
4569
4570                         if (num >= 0) {
4571                                 errno_name = errno_to_name(num);
4572                                 if (errno_name)
4573                                         fprintf(f, ":%s", errno_name);
4574                                 else
4575                                         fprintf(f, ":%d", num);
4576                         }
4577                 }
4578 #endif
4579
4580                 fputc('\n', f);
4581         }
4582
4583         if (c->syscall_archs) {
4584 #if HAVE_SECCOMP
4585                 Iterator j;
4586                 void *id;
4587 #endif
4588
4589                 fprintf(f,
4590                         "%sSystemCallArchitectures:",
4591                         prefix);
4592
4593 #if HAVE_SECCOMP
4594                 SET_FOREACH(id, c->syscall_archs, j)
4595                         fprintf(f, " %s", strna(seccomp_arch_to_string(PTR_TO_UINT32(id) - 1)));
4596 #endif
4597                 fputc('\n', f);
4598         }
4599
4600         if (exec_context_restrict_namespaces_set(c)) {
4601                 _cleanup_free_ char *s = NULL;
4602
4603                 r = namespace_flags_to_string(c->restrict_namespaces, &s);
4604                 if (r >= 0)
4605                         fprintf(f, "%sRestrictNamespaces: %s\n",
4606                                 prefix, s);
4607         }
4608
4609         if (c->network_namespace_path)
4610                 fprintf(f,
4611                         "%sNetworkNamespacePath: %s\n",
4612                         prefix, c->network_namespace_path);
4613
4614         if (c->syscall_errno > 0) {
4615                 const char *errno_name;
4616
4617                 fprintf(f, "%sSystemCallErrorNumber: ", prefix);
4618
4619                 errno_name = errno_to_name(c->syscall_errno);
4620                 if (errno_name)
4621                         fprintf(f, "%s\n", errno_name);
4622                 else
4623                         fprintf(f, "%d\n", c->syscall_errno);
4624         }
4625 }
4626
4627 bool exec_context_maintains_privileges(const ExecContext *c) {
4628         assert(c);
4629
4630         /* Returns true if the process forked off would run under
4631          * an unchanged UID or as root. */
4632
4633         if (!c->user)
4634                 return true;
4635
4636         if (streq(c->user, "root") || streq(c->user, "0"))
4637                 return true;
4638
4639         return false;
4640 }
4641
4642 int exec_context_get_effective_ioprio(const ExecContext *c) {
4643         int p;
4644
4645         assert(c);
4646
4647         if (c->ioprio_set)
4648                 return c->ioprio;
4649
4650         p = ioprio_get(IOPRIO_WHO_PROCESS, 0);
4651         if (p < 0)
4652                 return IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 4);
4653
4654         return p;
4655 }
4656
4657 void exec_context_free_log_extra_fields(ExecContext *c) {
4658         size_t l;
4659
4660         assert(c);
4661
4662         for (l = 0; l < c->n_log_extra_fields; l++)
4663                 free(c->log_extra_fields[l].iov_base);
4664         c->log_extra_fields = mfree(c->log_extra_fields);
4665         c->n_log_extra_fields = 0;
4666 }
4667
4668 void exec_context_revert_tty(ExecContext *c) {
4669         int r;
4670
4671         assert(c);
4672
4673         /* First, reset the TTY (possibly kicking everybody else from the TTY) */
4674         exec_context_tty_reset(c, NULL);
4675
4676         /* And then undo what chown_terminal() did earlier. Note that we only do this if we have a path
4677          * configured. If the TTY was passed to us as file descriptor we assume the TTY is opened and managed
4678          * by whoever passed it to us and thus knows better when and how to chmod()/chown() it back. */
4679
4680         if (exec_context_may_touch_tty(c)) {
4681                 const char *path;
4682
4683                 path = exec_context_tty_path(c);
4684                 if (path) {
4685                         r = chmod_and_chown(path, TTY_MODE, 0, TTY_GID);
4686                         if (r < 0 && r != -ENOENT)
4687                                 log_warning_errno(r, "Failed to reset TTY ownership/access mode of %s, ignoring: %m", path);
4688                 }
4689         }
4690 }
4691
4692 void exec_status_start(ExecStatus *s, pid_t pid) {
4693         assert(s);
4694
4695         *s = (ExecStatus) {
4696                 .pid = pid,
4697         };
4698
4699         dual_timestamp_get(&s->start_timestamp);
4700 }
4701
4702 void exec_status_exit(ExecStatus *s, const ExecContext *context, pid_t pid, int code, int status) {
4703         assert(s);
4704
4705         if (s->pid != pid) {
4706                 *s = (ExecStatus) {
4707                         .pid = pid,
4708                 };
4709         }
4710
4711         dual_timestamp_get(&s->exit_timestamp);
4712
4713         s->code = code;
4714         s->status = status;
4715
4716         if (context && context->utmp_id)
4717                 (void) utmp_put_dead_process(context->utmp_id, pid, code, status);
4718 }
4719
4720 void exec_status_reset(ExecStatus *s) {
4721         assert(s);
4722
4723         *s = (ExecStatus) {};
4724 }
4725
4726 void exec_status_dump(const ExecStatus *s, FILE *f, const char *prefix) {
4727         char buf[FORMAT_TIMESTAMP_MAX];
4728
4729         assert(s);
4730         assert(f);
4731
4732         if (s->pid <= 0)
4733                 return;
4734
4735         prefix = strempty(prefix);
4736
4737         fprintf(f,
4738                 "%sPID: "PID_FMT"\n",
4739                 prefix, s->pid);
4740
4741         if (dual_timestamp_is_set(&s->start_timestamp))
4742                 fprintf(f,
4743                         "%sStart Timestamp: %s\n",
4744                         prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp.realtime));
4745
4746         if (dual_timestamp_is_set(&s->exit_timestamp))
4747                 fprintf(f,
4748                         "%sExit Timestamp: %s\n"
4749                         "%sExit Code: %s\n"
4750                         "%sExit Status: %i\n",
4751                         prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp.realtime),
4752                         prefix, sigchld_code_to_string(s->code),
4753                         prefix, s->status);
4754 }
4755
4756 static char *exec_command_line(char **argv) {
4757         size_t k;
4758         char *n, *p, **a;
4759         bool first = true;
4760
4761         assert(argv);
4762
4763         k = 1;
4764         STRV_FOREACH(a, argv)
4765                 k += strlen(*a)+3;
4766
4767         n = new(char, k);
4768         if (!n)
4769                 return NULL;
4770
4771         p = n;
4772         STRV_FOREACH(a, argv) {
4773
4774                 if (!first)
4775                         *(p++) = ' ';
4776                 else
4777                         first = false;
4778
4779                 if (strpbrk(*a, WHITESPACE)) {
4780                         *(p++) = '\'';
4781                         p = stpcpy(p, *a);
4782                         *(p++) = '\'';
4783                 } else
4784                         p = stpcpy(p, *a);
4785
4786         }
4787
4788         *p = 0;
4789
4790         /* FIXME: this doesn't really handle arguments that have
4791          * spaces and ticks in them */
4792
4793         return n;
4794 }
4795
4796 static void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
4797         _cleanup_free_ char *cmd = NULL;
4798         const char *prefix2;
4799
4800         assert(c);
4801         assert(f);
4802
4803         prefix = strempty(prefix);
4804         prefix2 = strjoina(prefix, "\t");
4805
4806         cmd = exec_command_line(c->argv);
4807         fprintf(f,
4808                 "%sCommand Line: %s\n",
4809                 prefix, cmd ? cmd : strerror(ENOMEM));
4810
4811         exec_status_dump(&c->exec_status, f, prefix2);
4812 }
4813
4814 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
4815         assert(f);
4816
4817         prefix = strempty(prefix);
4818
4819         LIST_FOREACH(command, c, c)
4820                 exec_command_dump(c, f, prefix);
4821 }
4822
4823 void exec_command_append_list(ExecCommand **l, ExecCommand *e) {
4824         ExecCommand *end;
4825
4826         assert(l);
4827         assert(e);
4828
4829         if (*l) {
4830                 /* It's kind of important, that we keep the order here */
4831                 LIST_FIND_TAIL(command, *l, end);
4832                 LIST_INSERT_AFTER(command, *l, end, e);
4833         } else
4834               *l = e;
4835 }
4836
4837 int exec_command_set(ExecCommand *c, const char *path, ...) {
4838         va_list ap;
4839         char **l, *p;
4840
4841         assert(c);
4842         assert(path);
4843
4844         va_start(ap, path);
4845         l = strv_new_ap(path, ap);
4846         va_end(ap);
4847
4848         if (!l)
4849                 return -ENOMEM;
4850
4851         p = strdup(path);
4852         if (!p) {
4853                 strv_free(l);
4854                 return -ENOMEM;
4855         }
4856
4857         free_and_replace(c->path, p);
4858
4859         return strv_free_and_replace(c->argv, l);
4860 }
4861
4862 int exec_command_append(ExecCommand *c, const char *path, ...) {
4863         _cleanup_strv_free_ char **l = NULL;
4864         va_list ap;
4865         int r;
4866
4867         assert(c);
4868         assert(path);
4869
4870         va_start(ap, path);
4871         l = strv_new_ap(path, ap);
4872         va_end(ap);
4873
4874         if (!l)
4875                 return -ENOMEM;
4876
4877         r = strv_extend_strv(&c->argv, l, false);
4878         if (r < 0)
4879                 return r;
4880
4881         return 0;
4882 }
4883
4884 static void *remove_tmpdir_thread(void *p) {
4885         _cleanup_free_ char *path = p;
4886
4887         (void) rm_rf(path, REMOVE_ROOT|REMOVE_PHYSICAL);
4888         return NULL;
4889 }
4890
4891 static ExecRuntime* exec_runtime_free(ExecRuntime *rt, bool destroy) {
4892         int r;
4893
4894         if (!rt)
4895                 return NULL;
4896
4897         if (rt->manager)
4898                 (void) hashmap_remove(rt->manager->exec_runtime_by_id, rt->id);
4899
4900         /* When destroy is true, then rm_rf tmp_dir and var_tmp_dir. */
4901         if (destroy && rt->tmp_dir) {
4902                 log_debug("Spawning thread to nuke %s", rt->tmp_dir);
4903
4904                 r = asynchronous_job(remove_tmpdir_thread, rt->tmp_dir);
4905                 if (r < 0) {
4906                         log_warning_errno(r, "Failed to nuke %s: %m", rt->tmp_dir);
4907                         free(rt->tmp_dir);
4908                 }
4909
4910                 rt->tmp_dir = NULL;
4911         }
4912
4913         if (destroy && rt->var_tmp_dir) {
4914                 log_debug("Spawning thread to nuke %s", rt->var_tmp_dir);
4915
4916                 r = asynchronous_job(remove_tmpdir_thread, rt->var_tmp_dir);
4917                 if (r < 0) {
4918                         log_warning_errno(r, "Failed to nuke %s: %m", rt->var_tmp_dir);
4919                         free(rt->var_tmp_dir);
4920                 }
4921
4922                 rt->var_tmp_dir = NULL;
4923         }
4924
4925         rt->id = mfree(rt->id);
4926         rt->tmp_dir = mfree(rt->tmp_dir);
4927         rt->var_tmp_dir = mfree(rt->var_tmp_dir);
4928         safe_close_pair(rt->netns_storage_socket);
4929         return mfree(rt);
4930 }
4931
4932 static void exec_runtime_freep(ExecRuntime **rt) {
4933         (void) exec_runtime_free(*rt, false);
4934 }
4935
4936 static int exec_runtime_allocate(ExecRuntime **ret) {
4937         ExecRuntime *n;
4938
4939         assert(ret);
4940
4941         n = new(ExecRuntime, 1);
4942         if (!n)
4943                 return -ENOMEM;
4944
4945         *n = (ExecRuntime) {
4946                 .netns_storage_socket = { -1, -1 },
4947         };
4948
4949         *ret = n;
4950         return 0;
4951 }
4952
4953 static int exec_runtime_add(
4954                 Manager *m,
4955                 const char *id,
4956                 const char *tmp_dir,
4957                 const char *var_tmp_dir,
4958                 const int netns_storage_socket[2],
4959                 ExecRuntime **ret) {
4960
4961         _cleanup_(exec_runtime_freep) ExecRuntime *rt = NULL;
4962         int r;
4963
4964         assert(m);
4965         assert(id);
4966
4967         r = hashmap_ensure_allocated(&m->exec_runtime_by_id, &string_hash_ops);
4968         if (r < 0)
4969                 return r;
4970
4971         r = exec_runtime_allocate(&rt);
4972         if (r < 0)
4973                 return r;
4974
4975         rt->id = strdup(id);
4976         if (!rt->id)
4977                 return -ENOMEM;
4978
4979         if (tmp_dir) {
4980                 rt->tmp_dir = strdup(tmp_dir);
4981                 if (!rt->tmp_dir)
4982                         return -ENOMEM;
4983
4984                 /* When tmp_dir is set, then we require var_tmp_dir is also set. */
4985                 assert(var_tmp_dir);
4986                 rt->var_tmp_dir = strdup(var_tmp_dir);
4987                 if (!rt->var_tmp_dir)
4988                         return -ENOMEM;
4989         }
4990
4991         if (netns_storage_socket) {
4992                 rt->netns_storage_socket[0] = netns_storage_socket[0];
4993                 rt->netns_storage_socket[1] = netns_storage_socket[1];
4994         }
4995
4996         r = hashmap_put(m->exec_runtime_by_id, rt->id, rt);
4997         if (r < 0)
4998                 return r;
4999
5000         rt->manager = m;
5001
5002         if (ret)
5003                 *ret = rt;
5004
5005         /* do not remove created ExecRuntime object when the operation succeeds. */
5006         rt = NULL;
5007         return 0;
5008 }
5009
5010 static int exec_runtime_make(Manager *m, const ExecContext *c, const char *id, ExecRuntime **ret) {
5011         _cleanup_free_ char *tmp_dir = NULL, *var_tmp_dir = NULL;
5012         _cleanup_close_pair_ int netns_storage_socket[2] = { -1, -1 };
5013         int r;
5014
5015         assert(m);
5016         assert(c);
5017         assert(id);
5018
5019         /* It is not necessary to create ExecRuntime object. */
5020         if (!c->private_network && !c->private_tmp && !c->network_namespace_path)
5021                 return 0;
5022
5023         if (c->private_tmp) {
5024                 r = setup_tmp_dirs(id, &tmp_dir, &var_tmp_dir);
5025                 if (r < 0)
5026                         return r;
5027         }
5028
5029         if (c->private_network || c->network_namespace_path) {
5030                 if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, netns_storage_socket) < 0)
5031                         return -errno;
5032         }
5033
5034         r = exec_runtime_add(m, id, tmp_dir, var_tmp_dir, netns_storage_socket, ret);
5035         if (r < 0)
5036                 return r;
5037
5038         /* Avoid cleanup */
5039         netns_storage_socket[0] = netns_storage_socket[1] = -1;
5040         return 1;
5041 }
5042
5043 int exec_runtime_acquire(Manager *m, const ExecContext *c, const char *id, bool create, ExecRuntime **ret) {
5044         ExecRuntime *rt;
5045         int r;
5046
5047         assert(m);
5048         assert(id);
5049         assert(ret);
5050
5051         rt = hashmap_get(m->exec_runtime_by_id, id);
5052         if (rt)
5053                 /* We already have a ExecRuntime object, let's increase the ref count and reuse it */
5054                 goto ref;
5055
5056         if (!create)
5057                 return 0;
5058
5059         /* If not found, then create a new object. */
5060         r = exec_runtime_make(m, c, id, &rt);
5061         if (r <= 0)
5062                 /* When r == 0, it is not necessary to create ExecRuntime object. */
5063                 return r;
5064
5065 ref:
5066         /* increment reference counter. */
5067         rt->n_ref++;
5068         *ret = rt;
5069         return 1;
5070 }
5071
5072 ExecRuntime *exec_runtime_unref(ExecRuntime *rt, bool destroy) {
5073         if (!rt)
5074                 return NULL;
5075
5076         assert(rt->n_ref > 0);
5077
5078         rt->n_ref--;
5079         if (rt->n_ref > 0)
5080                 return NULL;
5081
5082         return exec_runtime_free(rt, destroy);
5083 }
5084
5085 int exec_runtime_serialize(const Manager *m, FILE *f, FDSet *fds) {
5086         ExecRuntime *rt;
5087         Iterator i;
5088
5089         assert(m);
5090         assert(f);
5091         assert(fds);
5092
5093         HASHMAP_FOREACH(rt, m->exec_runtime_by_id, i) {
5094                 fprintf(f, "exec-runtime=%s", rt->id);
5095
5096                 if (rt->tmp_dir)
5097                         fprintf(f, " tmp-dir=%s", rt->tmp_dir);
5098
5099                 if (rt->var_tmp_dir)
5100                         fprintf(f, " var-tmp-dir=%s", rt->var_tmp_dir);
5101
5102                 if (rt->netns_storage_socket[0] >= 0) {
5103                         int copy;
5104
5105                         copy = fdset_put_dup(fds, rt->netns_storage_socket[0]);
5106                         if (copy < 0)
5107                                 return copy;
5108
5109                         fprintf(f, " netns-socket-0=%i", copy);
5110                 }
5111
5112                 if (rt->netns_storage_socket[1] >= 0) {
5113                         int copy;
5114
5115                         copy = fdset_put_dup(fds, rt->netns_storage_socket[1]);
5116                         if (copy < 0)
5117                                 return copy;
5118
5119                         fprintf(f, " netns-socket-1=%i", copy);
5120                 }
5121
5122                 fputc('\n', f);
5123         }
5124
5125         return 0;
5126 }
5127
5128 int exec_runtime_deserialize_compat(Unit *u, const char *key, const char *value, FDSet *fds) {
5129         _cleanup_(exec_runtime_freep) ExecRuntime *rt_create = NULL;
5130         ExecRuntime *rt;
5131         int r;
5132
5133         /* This is for the migration from old (v237 or earlier) deserialization text.
5134          * Due to the bug #7790, this may not work with the units that use JoinsNamespaceOf=.
5135          * Even if the ExecRuntime object originally created by the other unit, we cannot judge
5136          * so or not from the serialized text, then we always creates a new object owned by this. */
5137
5138         assert(u);
5139         assert(key);
5140         assert(value);
5141
5142         /* Manager manages ExecRuntime objects by the unit id.
5143          * So, we omit the serialized text when the unit does not have id (yet?)... */
5144         if (isempty(u->id)) {
5145                 log_unit_debug(u, "Invocation ID not found. Dropping runtime parameter.");
5146                 return 0;
5147         }
5148
5149         r = hashmap_ensure_allocated(&u->manager->exec_runtime_by_id, &string_hash_ops);
5150         if (r < 0) {
5151                 log_unit_debug_errno(u, r, "Failed to allocate storage for runtime parameter: %m");
5152                 return 0;
5153         }
5154
5155         rt = hashmap_get(u->manager->exec_runtime_by_id, u->id);
5156         if (!rt) {
5157                 r = exec_runtime_allocate(&rt_create);
5158                 if (r < 0)
5159                         return log_oom();
5160
5161                 rt_create->id = strdup(u->id);
5162                 if (!rt_create->id)
5163                         return log_oom();
5164
5165                 rt = rt_create;
5166         }
5167
5168         if (streq(key, "tmp-dir")) {
5169                 char *copy;
5170
5171                 copy = strdup(value);
5172                 if (!copy)
5173                         return log_oom();
5174
5175                 free_and_replace(rt->tmp_dir, copy);
5176
5177         } else if (streq(key, "var-tmp-dir")) {
5178                 char *copy;
5179
5180                 copy = strdup(value);
5181                 if (!copy)
5182                         return log_oom();
5183
5184                 free_and_replace(rt->var_tmp_dir, copy);
5185
5186         } else if (streq(key, "netns-socket-0")) {
5187                 int fd;
5188
5189                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd)) {
5190                         log_unit_debug(u, "Failed to parse netns socket value: %s", value);
5191                         return 0;
5192                 }
5193
5194                 safe_close(rt->netns_storage_socket[0]);
5195                 rt->netns_storage_socket[0] = fdset_remove(fds, fd);
5196
5197         } else if (streq(key, "netns-socket-1")) {
5198                 int fd;
5199
5200                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd)) {
5201                         log_unit_debug(u, "Failed to parse netns socket value: %s", value);
5202                         return 0;
5203                 }
5204
5205                 safe_close(rt->netns_storage_socket[1]);
5206                 rt->netns_storage_socket[1] = fdset_remove(fds, fd);
5207         } else
5208                 return 0;
5209
5210         /* If the object is newly created, then put it to the hashmap which manages ExecRuntime objects. */
5211         if (rt_create) {
5212                 r = hashmap_put(u->manager->exec_runtime_by_id, rt_create->id, rt_create);
5213                 if (r < 0) {
5214                         log_unit_debug_errno(u, r, "Failed to put runtime parameter to manager's storage: %m");
5215                         return 0;
5216                 }
5217
5218                 rt_create->manager = u->manager;
5219
5220                 /* Avoid cleanup */
5221                 rt_create = NULL;
5222         }
5223
5224         return 1;
5225 }
5226
5227 void exec_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds) {
5228         char *id = NULL, *tmp_dir = NULL, *var_tmp_dir = NULL;
5229         int r, fd0 = -1, fd1 = -1;
5230         const char *p, *v = value;
5231         size_t n;
5232
5233         assert(m);
5234         assert(value);
5235         assert(fds);
5236
5237         n = strcspn(v, " ");
5238         id = strndupa(v, n);
5239         if (v[n] != ' ')
5240                 goto finalize;
5241         p = v + n + 1;
5242
5243         v = startswith(p, "tmp-dir=");
5244         if (v) {
5245                 n = strcspn(v, " ");
5246                 tmp_dir = strndupa(v, n);
5247                 if (v[n] != ' ')
5248                         goto finalize;
5249                 p = v + n + 1;
5250         }
5251
5252         v = startswith(p, "var-tmp-dir=");
5253         if (v) {
5254                 n = strcspn(v, " ");
5255                 var_tmp_dir = strndupa(v, n);
5256                 if (v[n] != ' ')
5257                         goto finalize;
5258                 p = v + n + 1;
5259         }
5260
5261         v = startswith(p, "netns-socket-0=");
5262         if (v) {
5263                 char *buf;
5264
5265                 n = strcspn(v, " ");
5266                 buf = strndupa(v, n);
5267                 if (safe_atoi(buf, &fd0) < 0 || !fdset_contains(fds, fd0)) {
5268                         log_debug("Unable to process exec-runtime netns fd specification.");
5269                         return;
5270                 }
5271                 fd0 = fdset_remove(fds, fd0);
5272                 if (v[n] != ' ')
5273                         goto finalize;
5274                 p = v + n + 1;
5275         }
5276
5277         v = startswith(p, "netns-socket-1=");
5278         if (v) {
5279                 char *buf;
5280
5281                 n = strcspn(v, " ");
5282                 buf = strndupa(v, n);
5283                 if (safe_atoi(buf, &fd1) < 0 || !fdset_contains(fds, fd1)) {
5284                         log_debug("Unable to process exec-runtime netns fd specification.");
5285                         return;
5286                 }
5287                 fd1 = fdset_remove(fds, fd1);
5288         }
5289
5290 finalize:
5291
5292         r = exec_runtime_add(m, id, tmp_dir, var_tmp_dir, (int[]) { fd0, fd1 }, NULL);
5293         if (r < 0)
5294                 log_debug_errno(r, "Failed to add exec-runtime: %m");
5295 }
5296
5297 void exec_runtime_vacuum(Manager *m) {
5298         ExecRuntime *rt;
5299         Iterator i;
5300
5301         assert(m);
5302
5303         /* Free unreferenced ExecRuntime objects. This is used after manager deserialization process. */
5304
5305         HASHMAP_FOREACH(rt, m->exec_runtime_by_id, i) {
5306                 if (rt->n_ref > 0)
5307                         continue;
5308
5309                 (void) exec_runtime_free(rt, false);
5310         }
5311 }
5312
5313 void exec_params_clear(ExecParameters *p) {
5314         if (!p)
5315                 return;
5316
5317         strv_free(p->environment);
5318 }
5319
5320 static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
5321         [EXEC_INPUT_NULL] = "null",
5322         [EXEC_INPUT_TTY] = "tty",
5323         [EXEC_INPUT_TTY_FORCE] = "tty-force",
5324         [EXEC_INPUT_TTY_FAIL] = "tty-fail",
5325         [EXEC_INPUT_SOCKET] = "socket",
5326         [EXEC_INPUT_NAMED_FD] = "fd",
5327         [EXEC_INPUT_DATA] = "data",
5328         [EXEC_INPUT_FILE] = "file",
5329 };
5330
5331 DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);
5332
5333 static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
5334         [EXEC_OUTPUT_INHERIT] = "inherit",
5335         [EXEC_OUTPUT_NULL] = "null",
5336         [EXEC_OUTPUT_TTY] = "tty",
5337         [EXEC_OUTPUT_SYSLOG] = "syslog",
5338         [EXEC_OUTPUT_SYSLOG_AND_CONSOLE] = "syslog+console",
5339         [EXEC_OUTPUT_KMSG] = "kmsg",
5340         [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
5341         [EXEC_OUTPUT_JOURNAL] = "journal",
5342         [EXEC_OUTPUT_JOURNAL_AND_CONSOLE] = "journal+console",
5343         [EXEC_OUTPUT_SOCKET] = "socket",
5344         [EXEC_OUTPUT_NAMED_FD] = "fd",
5345         [EXEC_OUTPUT_FILE] = "file",
5346         [EXEC_OUTPUT_FILE_APPEND] = "append",
5347 };
5348
5349 DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);
5350
5351 static const char* const exec_utmp_mode_table[_EXEC_UTMP_MODE_MAX] = {
5352         [EXEC_UTMP_INIT] = "init",
5353         [EXEC_UTMP_LOGIN] = "login",
5354         [EXEC_UTMP_USER] = "user",
5355 };
5356
5357 DEFINE_STRING_TABLE_LOOKUP(exec_utmp_mode, ExecUtmpMode);
5358
5359 static const char* const exec_preserve_mode_table[_EXEC_PRESERVE_MODE_MAX] = {
5360         [EXEC_PRESERVE_NO] = "no",
5361         [EXEC_PRESERVE_YES] = "yes",
5362         [EXEC_PRESERVE_RESTART] = "restart",
5363 };
5364
5365 DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(exec_preserve_mode, ExecPreserveMode, EXEC_PRESERVE_YES);
5366
5367 static const char* const exec_directory_type_table[_EXEC_DIRECTORY_TYPE_MAX] = {
5368         [EXEC_DIRECTORY_RUNTIME] = "RuntimeDirectory",
5369         [EXEC_DIRECTORY_STATE] = "StateDirectory",
5370         [EXEC_DIRECTORY_CACHE] = "CacheDirectory",
5371         [EXEC_DIRECTORY_LOGS] = "LogsDirectory",
5372         [EXEC_DIRECTORY_CONFIGURATION] = "ConfigurationDirectory",
5373 };
5374
5375 DEFINE_STRING_TABLE_LOOKUP(exec_directory_type, ExecDirectoryType);
5376
5377 static const char* const exec_directory_env_name_table[_EXEC_DIRECTORY_TYPE_MAX] = {
5378         [EXEC_DIRECTORY_RUNTIME] = "RUNTIME_DIRECTORY",
5379         [EXEC_DIRECTORY_STATE] = "STATE_DIRECTORY",
5380         [EXEC_DIRECTORY_CACHE] = "CACHE_DIRECTORY",
5381         [EXEC_DIRECTORY_LOGS] = "LOGS_DIRECTORY",
5382         [EXEC_DIRECTORY_CONFIGURATION] = "CONFIGURATION_DIRECTORY",
5383 };
5384
5385 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(exec_directory_env_name, ExecDirectoryType);
5386
5387 static const char* const exec_keyring_mode_table[_EXEC_KEYRING_MODE_MAX] = {
5388         [EXEC_KEYRING_INHERIT] = "inherit",
5389         [EXEC_KEYRING_PRIVATE] = "private",
5390         [EXEC_KEYRING_SHARED] = "shared",
5391 };
5392
5393 DEFINE_STRING_TABLE_LOOKUP(exec_keyring_mode, ExecKeyringMode);