src/core/execute.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <glob.h>
  23 #include <grp.h>
  24 #include <poll.h>
  25 #include <signal.h>
  26 #include <string.h>
  27 #include <sys/capability.h>
  28 #include <sys/eventfd.h>
  29 #include <sys/mman.h>
  30 #include <sys/personality.h>
  31 #include <sys/prctl.h>
  32 #include <sys/socket.h>
  33 #include <sys/stat.h>
  34 #include <sys/un.h>
  35 #include <unistd.h>
  36 #include <utmpx.h>
  37
  38 #ifdef HAVE_PAM
  39 #include <security/pam_appl.h>
  40 #endif
  41
  42 #ifdef HAVE_SELINUX
  43 #include <selinux/selinux.h>
  44 #endif
  45
  46 #ifdef HAVE_SECCOMP
  47 #include <seccomp.h>
  48 #endif
  49
  50 #ifdef HAVE_APPARMOR
  51 #include <sys/apparmor.h>
  52 #endif
  53
  54 #include "sd-messages.h"
  55
  56 #include "af-list.h"
  57 #include "alloc-util.h"
  58 #ifdef HAVE_APPARMOR
  59 #include "apparmor-util.h"
  60 #endif
  61 #include "async.h"
  62 #include "barrier.h"
  63 #include "cap-list.h"
  64 #include "capability-util.h"
  65 #include "def.h"
  66 #include "env-util.h"
  67 #include "errno-list.h"
  68 #include "execute.h"
  69 #include "exit-status.h"
  70 #include "fd-util.h"
  71 #include "fileio.h"
  72 #include "formats-util.h"
  73 #include "fs-util.h"
  74 #include "glob-util.h"
  75 #include "io-util.h"
  76 #include "ioprio.h"
  77 #include "log.h"
  78 #include "macro.h"
  79 #include "missing.h"
  80 #include "mkdir.h"
  81 #include "namespace.h"
  82 #include "parse-util.h"
  83 #include "path-util.h"
  84 #include "process-util.h"
  85 #include "rlimit-util.h"
  86 #include "rm-rf.h"
  87 #ifdef HAVE_SECCOMP
  88 #include "seccomp-util.h"
  89 #endif
  90 #include "securebits.h"
  91 #include "selinux-util.h"
  92 #include "signal-util.h"
  93 #include "smack-util.h"
  94 #include "special.h"
  95 #include "string-table.h"
  96 #include "string-util.h"
  97 #include "strv.h"
  98 #include "syslog-util.h"
  99 #include "terminal-util.h"
 100 #include "unit.h"
 101 #include "user-util.h"
 102 #include "util.h"
 103 #include "utmp-wtmp.h"
 104
 105 #define IDLE_TIMEOUT_USEC (5*USEC_PER_SEC)
 106 #define IDLE_TIMEOUT2_USEC (1*USEC_PER_SEC)
 107
 108 /* This assumes there is a 'tty' group */
 109 #define TTY_MODE 0620
 110
 111 #define SNDBUF_SIZE (8*1024*1024)
 112
 113 static int shift_fds(int fds[], unsigned n_fds) {
 114         int start, restart_from;
 115
 116         if (n_fds <= 0)
 117                 return 0;
 118
 119         /* Modifies the fds array! (sorts it) */
 120
 121         assert(fds);
 122
 123         start = 0;
 124         for (;;) {
 125                 int i;
 126
 127                 restart_from = -1;
 128
 129                 for (i = start; i < (int) n_fds; i++) {
 130                         int nfd;
 131
 132                         /* Already at right index? */
 133                         if (fds[i] == i+3)
 134                                 continue;
 135
 136                         nfd = fcntl(fds[i], F_DUPFD, i + 3);
 137                         if (nfd < 0)
 138                                 return -errno;
 139
 140                         safe_close(fds[i]);
 141                         fds[i] = nfd;
 142
 143                         /* Hmm, the fd we wanted isn't free? Then
 144                          * let's remember that and try again from here */
 145                         if (nfd != i+3 && restart_from < 0)
 146                                 restart_from = i;
 147                 }
 148
 149                 if (restart_from < 0)
 150                         break;
 151
 152                 start = restart_from;
 153         }
 154
 155         return 0;
 156 }
 157
 158 static int flags_fds(const int fds[], unsigned n_fds, bool nonblock) {
 159         unsigned i;
 160         int r;
 161
 162         if (n_fds <= 0)
 163                 return 0;
 164
 165         assert(fds);
 166
 167         /* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags */
 168
 169         for (i = 0; i < n_fds; i++) {
 170
 171                 r = fd_nonblock(fds[i], nonblock);
 172                 if (r < 0)
 173                         return r;
 174
 175                 /* We unconditionally drop FD_CLOEXEC from the fds,
 176                  * since after all we want to pass these fds to our
 177                  * children */
 178
 179                 r = fd_cloexec(fds[i], false);
 180                 if (r < 0)
 181                         return r;
 182         }
 183
 184         return 0;
 185 }
 186
 187 static const char *exec_context_tty_path(const ExecContext *context) {
 188         assert(context);
 189
 190         if (context->stdio_as_fds)
 191                 return NULL;
 192
 193         if (context->tty_path)
 194                 return context->tty_path;
 195
 196         return "/dev/console";
 197 }
 198
 199 static void exec_context_tty_reset(const ExecContext *context, const ExecParameters *p) {
 200         const char *path;
 201
 202         assert(context);
 203
 204         path = exec_context_tty_path(context);
 205
 206         if (context->tty_vhangup) {
 207                 if (p && p->stdin_fd >= 0)
 208                         (void) terminal_vhangup_fd(p->stdin_fd);
 209                 else if (path)
 210                         (void) terminal_vhangup(path);
 211         }
 212
 213         if (context->tty_reset) {
 214                 if (p && p->stdin_fd >= 0)
 215                         (void) reset_terminal_fd(p->stdin_fd, true);
 216                 else if (path)
 217                         (void) reset_terminal(path);
 218         }
 219
 220         if (context->tty_vt_disallocate && path)
 221                 (void) vt_disallocate(path);
 222 }
 223
 224 static bool is_terminal_input(ExecInput i) {
 225         return IN_SET(i,
 226                       EXEC_INPUT_TTY,
 227                       EXEC_INPUT_TTY_FORCE,
 228                       EXEC_INPUT_TTY_FAIL);
 229 }
 230
 231 static bool is_terminal_output(ExecOutput o) {
 232         return IN_SET(o,
 233                       EXEC_OUTPUT_TTY,
 234                       EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
 235                       EXEC_OUTPUT_KMSG_AND_CONSOLE,
 236                       EXEC_OUTPUT_JOURNAL_AND_CONSOLE);
 237 }
 238
 239 static bool exec_context_needs_term(const ExecContext *c) {
 240         assert(c);
 241
 242         /* Return true if the execution context suggests we should set $TERM to something useful. */
 243
 244         if (is_terminal_input(c->std_input))
 245                 return true;
 246
 247         if (is_terminal_output(c->std_output))
 248                 return true;
 249
 250         if (is_terminal_output(c->std_error))
 251                 return true;
 252
 253         return !!c->tty_path;
 254 }
 255
 256 static int open_null_as(int flags, int nfd) {
 257         int fd, r;
 258
 259         assert(nfd >= 0);
 260
 261         fd = open("/dev/null", flags|O_NOCTTY);
 262         if (fd < 0)
 263                 return -errno;
 264
 265         if (fd != nfd) {
 266                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 267                 safe_close(fd);
 268         } else
 269                 r = nfd;
 270
 271         return r;
 272 }
 273
 274 static int connect_journal_socket(int fd, uid_t uid, gid_t gid) {
 275         union sockaddr_union sa = {
 276                 .un.sun_family = AF_UNIX,
 277                 .un.sun_path = "/run/systemd/journal/stdout",
 278         };
 279         uid_t olduid = UID_INVALID;
 280         gid_t oldgid = GID_INVALID;
 281         int r;
 282
 283         if (gid != GID_INVALID) {
 284                 oldgid = getgid();
 285
 286                 r = setegid(gid);
 287                 if (r < 0)
 288                         return -errno;
 289         }
 290
 291         if (uid != UID_INVALID) {
 292                 olduid = getuid();
 293
 294                 r = seteuid(uid);
 295                 if (r < 0) {
 296                         r = -errno;
 297                         goto restore_gid;
 298                 }
 299         }
 300
 301         r = connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
 302         if (r < 0)
 303                 r = -errno;
 304
 305         /* If we fail to restore the uid or gid, things will likely
 306            fail later on. This should only happen if an LSM interferes. */
 307
 308         if (uid != UID_INVALID)
 309                 (void) seteuid(olduid);
 310
 311  restore_gid:
 312         if (gid != GID_INVALID)
 313                 (void) setegid(oldgid);
 314
 315         return r;
 316 }
 317
 318 static int connect_logger_as(
 319                 Unit *unit,
 320                 const ExecContext *context,
 321                 ExecOutput output,
 322                 const char *ident,
 323                 int nfd,
 324                 uid_t uid,
 325                 gid_t gid) {
 326
 327         int fd, r;
 328
 329         assert(context);
 330         assert(output < _EXEC_OUTPUT_MAX);
 331         assert(ident);
 332         assert(nfd >= 0);
 333
 334         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 335         if (fd < 0)
 336                 return -errno;
 337
 338         r = connect_journal_socket(fd, uid, gid);
 339         if (r < 0)
 340                 return r;
 341
 342         if (shutdown(fd, SHUT_RD) < 0) {
 343                 safe_close(fd);
 344                 return -errno;
 345         }
 346
 347         (void) fd_inc_sndbuf(fd, SNDBUF_SIZE);
 348
 349         dprintf(fd,
 350                 "%s\n"
 351                 "%s\n"
 352                 "%i\n"
 353                 "%i\n"
 354                 "%i\n"
 355                 "%i\n"
 356                 "%i\n",
 357                 context->syslog_identifier ? context->syslog_identifier : ident,
 358                 unit->id,
 359                 context->syslog_priority,
 360                 !!context->syslog_level_prefix,
 361                 output == EXEC_OUTPUT_SYSLOG || output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
 362                 output == EXEC_OUTPUT_KMSG || output == EXEC_OUTPUT_KMSG_AND_CONSOLE,
 363                 is_terminal_output(output));
 364
 365         if (fd == nfd)
 366                 return nfd;
 367
 368         r = dup2(fd, nfd) < 0 ? -errno : nfd;
 369         safe_close(fd);
 370
 371         return r;
 372 }
 373 static int open_terminal_as(const char *path, mode_t mode, int nfd) {
 374         int fd, r;
 375
 376         assert(path);
 377         assert(nfd >= 0);
 378
 379         fd = open_terminal(path, mode | O_NOCTTY);
 380         if (fd < 0)
 381                 return fd;
 382
 383         if (fd != nfd) {
 384                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 385                 safe_close(fd);
 386         } else
 387                 r = nfd;
 388
 389         return r;
 390 }
 391
 392 static int fixup_input(ExecInput std_input, int socket_fd, bool apply_tty_stdin) {
 393
 394         if (is_terminal_input(std_input) && !apply_tty_stdin)
 395                 return EXEC_INPUT_NULL;
 396
 397         if (std_input == EXEC_INPUT_SOCKET && socket_fd < 0)
 398                 return EXEC_INPUT_NULL;
 399
 400         return std_input;
 401 }
 402
 403 static int fixup_output(ExecOutput std_output, int socket_fd) {
 404
 405         if (std_output == EXEC_OUTPUT_SOCKET && socket_fd < 0)
 406                 return EXEC_OUTPUT_INHERIT;
 407
 408         return std_output;
 409 }
 410
 411 static int setup_input(
 412                 const ExecContext *context,
 413                 const ExecParameters *params,
 414                 int socket_fd) {
 415
 416         ExecInput i;
 417
 418         assert(context);
 419         assert(params);
 420
 421         if (params->stdin_fd >= 0) {
 422                 if (dup2(params->stdin_fd, STDIN_FILENO) < 0)
 423                         return -errno;
 424
 425                 /* Try to make this the controlling tty, if it is a tty, and reset it */
 426                 (void) ioctl(STDIN_FILENO, TIOCSCTTY, context->std_input == EXEC_INPUT_TTY_FORCE);
 427                 (void) reset_terminal_fd(STDIN_FILENO, true);
 428
 429                 return STDIN_FILENO;
 430         }
 431
 432         i = fixup_input(context->std_input, socket_fd, params->flags & EXEC_APPLY_TTY_STDIN);
 433
 434         switch (i) {
 435
 436         case EXEC_INPUT_NULL:
 437                 return open_null_as(O_RDONLY, STDIN_FILENO);
 438
 439         case EXEC_INPUT_TTY:
 440         case EXEC_INPUT_TTY_FORCE:
 441         case EXEC_INPUT_TTY_FAIL: {
 442                 int fd, r;
 443
 444                 fd = acquire_terminal(exec_context_tty_path(context),
 445                                       i == EXEC_INPUT_TTY_FAIL,
 446                                       i == EXEC_INPUT_TTY_FORCE,
 447                                       false,
 448                                       USEC_INFINITY);
 449                 if (fd < 0)
 450                         return fd;
 451
 452                 if (fd != STDIN_FILENO) {
 453                         r = dup2(fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 454                         safe_close(fd);
 455                 } else
 456                         r = STDIN_FILENO;
 457
 458                 return r;
 459         }
 460
 461         case EXEC_INPUT_SOCKET:
 462                 return dup2(socket_fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 463
 464         default:
 465                 assert_not_reached("Unknown input type");
 466         }
 467 }
 468
 469 static int setup_output(
 470                 Unit *unit,
 471                 const ExecContext *context,
 472                 const ExecParameters *params,
 473                 int fileno,
 474                 int socket_fd,
 475                 const char *ident,
 476                 uid_t uid,
 477                 gid_t gid,
 478                 dev_t *journal_stream_dev,
 479                 ino_t *journal_stream_ino) {
 480
 481         ExecOutput o;
 482         ExecInput i;
 483         int r;
 484
 485         assert(unit);
 486         assert(context);
 487         assert(params);
 488         assert(ident);
 489         assert(journal_stream_dev);
 490         assert(journal_stream_ino);
 491
 492         if (fileno == STDOUT_FILENO && params->stdout_fd >= 0) {
 493
 494                 if (dup2(params->stdout_fd, STDOUT_FILENO) < 0)
 495                         return -errno;
 496
 497                 return STDOUT_FILENO;
 498         }
 499
 500         if (fileno == STDERR_FILENO && params->stderr_fd >= 0) {
 501                 if (dup2(params->stderr_fd, STDERR_FILENO) < 0)
 502                         return -errno;
 503
 504                 return STDERR_FILENO;
 505         }
 506
 507         i = fixup_input(context->std_input, socket_fd, params->flags & EXEC_APPLY_TTY_STDIN);
 508         o = fixup_output(context->std_output, socket_fd);
 509
 510         if (fileno == STDERR_FILENO) {
 511                 ExecOutput e;
 512                 e = fixup_output(context->std_error, socket_fd);
 513
 514                 /* This expects the input and output are already set up */
 515
 516                 /* Don't change the stderr file descriptor if we inherit all
 517                  * the way and are not on a tty */
 518                 if (e == EXEC_OUTPUT_INHERIT &&
 519                     o == EXEC_OUTPUT_INHERIT &&
 520                     i == EXEC_INPUT_NULL &&
 521                     !is_terminal_input(context->std_input) &&
 522                     getppid () != 1)
 523                         return fileno;
 524
 525                 /* Duplicate from stdout if possible */
 526                 if (e == o || e == EXEC_OUTPUT_INHERIT)
 527                         return dup2(STDOUT_FILENO, fileno) < 0 ? -errno : fileno;
 528
 529                 o = e;
 530
 531         } else if (o == EXEC_OUTPUT_INHERIT) {
 532                 /* If input got downgraded, inherit the original value */
 533                 if (i == EXEC_INPUT_NULL && is_terminal_input(context->std_input))
 534                         return open_terminal_as(exec_context_tty_path(context), O_WRONLY, fileno);
 535
 536                 /* If the input is connected to anything that's not a /dev/null, inherit that... */
 537                 if (i != EXEC_INPUT_NULL)
 538                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 539
 540                 /* If we are not started from PID 1 we just inherit STDOUT from our parent process. */
 541                 if (getppid() != 1)
 542                         return fileno;
 543
 544                 /* We need to open /dev/null here anew, to get the right access mode. */
 545                 return open_null_as(O_WRONLY, fileno);
 546         }
 547
 548         switch (o) {
 549
 550         case EXEC_OUTPUT_NULL:
 551                 return open_null_as(O_WRONLY, fileno);
 552
 553         case EXEC_OUTPUT_TTY:
 554                 if (is_terminal_input(i))
 555                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 556
 557                 /* We don't reset the terminal if this is just about output */
 558                 return open_terminal_as(exec_context_tty_path(context), O_WRONLY, fileno);
 559
 560         case EXEC_OUTPUT_SYSLOG:
 561         case EXEC_OUTPUT_SYSLOG_AND_CONSOLE:
 562         case EXEC_OUTPUT_KMSG:
 563         case EXEC_OUTPUT_KMSG_AND_CONSOLE:
 564         case EXEC_OUTPUT_JOURNAL:
 565         case EXEC_OUTPUT_JOURNAL_AND_CONSOLE:
 566                 r = connect_logger_as(unit, context, o, ident, fileno, uid, gid);
 567                 if (r < 0) {
 568                         log_unit_error_errno(unit, r, "Failed to connect %s to the journal socket, ignoring: %m", fileno == STDOUT_FILENO ? "stdout" : "stderr");
 569                         r = open_null_as(O_WRONLY, fileno);
 570                 } else {
 571                         struct stat st;
 572
 573                         /* If we connected this fd to the journal via a stream, patch the device/inode into the passed
 574                          * parameters, but only then. This is useful so that we can set $JOURNAL_STREAM that permits
 575                          * services to detect whether they are connected to the journal or not. */
 576
 577                         if (fstat(fileno, &st) >= 0) {
 578                                 *journal_stream_dev = st.st_dev;
 579                                 *journal_stream_ino = st.st_ino;
 580                         }
 581                 }
 582                 return r;
 583
 584         case EXEC_OUTPUT_SOCKET:
 585                 assert(socket_fd >= 0);
 586                 return dup2(socket_fd, fileno) < 0 ? -errno : fileno;
 587
 588         default:
 589                 assert_not_reached("Unknown error type");
 590         }
 591 }
 592
 593 static int chown_terminal(int fd, uid_t uid) {
 594         struct stat st;
 595
 596         assert(fd >= 0);
 597
 598         /* Before we chown/chmod the TTY, let's ensure this is actually a tty */
 599         if (isatty(fd) < 1)
 600                 return 0;
 601
 602         /* This might fail. What matters are the results. */
 603         (void) fchown(fd, uid, -1);
 604         (void) fchmod(fd, TTY_MODE);
 605
 606         if (fstat(fd, &st) < 0)
 607                 return -errno;
 608
 609         if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE)
 610                 return -EPERM;
 611
 612         return 0;
 613 }
 614
 615 static int setup_confirm_stdio(int *_saved_stdin, int *_saved_stdout) {
 616         _cleanup_close_ int fd = -1, saved_stdin = -1, saved_stdout = -1;
 617         int r;
 618
 619         assert(_saved_stdin);
 620         assert(_saved_stdout);
 621
 622         saved_stdin = fcntl(STDIN_FILENO, F_DUPFD, 3);
 623         if (saved_stdin < 0)
 624                 return -errno;
 625
 626         saved_stdout = fcntl(STDOUT_FILENO, F_DUPFD, 3);
 627         if (saved_stdout < 0)
 628                 return -errno;
 629
 630         fd = acquire_terminal(
 631                         "/dev/console",
 632                         false,
 633                         false,
 634                         false,
 635                         DEFAULT_CONFIRM_USEC);
 636         if (fd < 0)
 637                 return fd;
 638
 639         r = chown_terminal(fd, getuid());
 640         if (r < 0)
 641                 return r;
 642
 643         r = reset_terminal_fd(fd, true);
 644         if (r < 0)
 645                 return r;
 646
 647         if (dup2(fd, STDIN_FILENO) < 0)
 648                 return -errno;
 649
 650         if (dup2(fd, STDOUT_FILENO) < 0)
 651                 return -errno;
 652
 653         if (fd >= 2)
 654                 safe_close(fd);
 655         fd = -1;
 656
 657         *_saved_stdin = saved_stdin;
 658         *_saved_stdout = saved_stdout;
 659
 660         saved_stdin = saved_stdout = -1;
 661
 662         return 0;
 663 }
 664
 665 _printf_(1, 2) static int write_confirm_message(const char *format, ...) {
 666         _cleanup_close_ int fd = -1;
 667         va_list ap;
 668
 669         assert(format);
 670
 671         fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
 672         if (fd < 0)
 673                 return fd;
 674
 675         va_start(ap, format);
 676         vdprintf(fd, format, ap);
 677         va_end(ap);
 678
 679         return 0;
 680 }
 681
 682 static int restore_confirm_stdio(int *saved_stdin, int *saved_stdout) {
 683         int r = 0;
 684
 685         assert(saved_stdin);
 686         assert(saved_stdout);
 687
 688         release_terminal();
 689
 690         if (*saved_stdin >= 0)
 691                 if (dup2(*saved_stdin, STDIN_FILENO) < 0)
 692                         r = -errno;
 693
 694         if (*saved_stdout >= 0)
 695                 if (dup2(*saved_stdout, STDOUT_FILENO) < 0)
 696                         r = -errno;
 697
 698         *saved_stdin = safe_close(*saved_stdin);
 699         *saved_stdout = safe_close(*saved_stdout);
 700
 701         return r;
 702 }
 703
 704 static int ask_for_confirmation(char *response, char **argv) {
 705         int saved_stdout = -1, saved_stdin = -1, r;
 706         _cleanup_free_ char *line = NULL;
 707
 708         r = setup_confirm_stdio(&saved_stdin, &saved_stdout);
 709         if (r < 0)
 710                 return r;
 711
 712         line = exec_command_line(argv);
 713         if (!line)
 714                 return -ENOMEM;
 715
 716         r = ask_char(response, "yns", "Execute %s? [Yes, No, Skip] ", line);
 717
 718         restore_confirm_stdio(&saved_stdin, &saved_stdout);
 719
 720         return r;
 721 }
 722
 723 static int enforce_groups(const ExecContext *context, const char *username, gid_t gid) {
 724         bool keep_groups = false;
 725         int r;
 726
 727         assert(context);
 728
 729         /* Lookup and set GID and supplementary group list. Here too
 730          * we avoid NSS lookups for gid=0. */
 731
 732         if (context->group || username) {
 733                 /* First step, initialize groups from /etc/groups */
 734                 if (username && gid != 0) {
 735                         if (initgroups(username, gid) < 0)
 736                                 return -errno;
 737
 738                         keep_groups = true;
 739                 }
 740
 741                 /* Second step, set our gids */
 742                 if (setresgid(gid, gid, gid) < 0)
 743                         return -errno;
 744         }
 745
 746         if (context->supplementary_groups) {
 747                 int ngroups_max, k;
 748                 gid_t *gids;
 749                 char **i;
 750
 751                 /* Final step, initialize any manually set supplementary groups */
 752                 assert_se((ngroups_max = (int) sysconf(_SC_NGROUPS_MAX)) > 0);
 753
 754                 if (!(gids = new(gid_t, ngroups_max)))
 755                         return -ENOMEM;
 756
 757                 if (keep_groups) {
 758                         k = getgroups(ngroups_max, gids);
 759                         if (k < 0) {
 760                                 free(gids);
 761                                 return -errno;
 762                         }
 763                 } else
 764                         k = 0;
 765
 766                 STRV_FOREACH(i, context->supplementary_groups) {
 767                         const char *g;
 768
 769                         if (k >= ngroups_max) {
 770                                 free(gids);
 771                                 return -E2BIG;
 772                         }
 773
 774                         g = *i;
 775                         r = get_group_creds(&g, gids+k);
 776                         if (r < 0) {
 777                                 free(gids);
 778                                 return r;
 779                         }
 780
 781                         k++;
 782                 }
 783
 784                 if (maybe_setgroups(k, gids) < 0) {
 785                         free(gids);
 786                         return -errno;
 787                 }
 788
 789                 free(gids);
 790         }
 791
 792         return 0;
 793 }
 794
 795 static int enforce_user(const ExecContext *context, uid_t uid) {
 796         assert(context);
 797
 798         /* Sets (but doesn't look up) the uid and make sure we keep the
 799          * capabilities while doing so. */
 800
 801         if (context->capability_ambient_set != 0) {
 802
 803                 /* First step: If we need to keep capabilities but
 804                  * drop privileges we need to make sure we keep our
 805                  * caps, while we drop privileges. */
 806                 if (uid != 0) {
 807                         int sb = context->secure_bits | 1<<SECURE_KEEP_CAPS;
 808
 809                         if (prctl(PR_GET_SECUREBITS) != sb)
 810                                 if (prctl(PR_SET_SECUREBITS, sb) < 0)
 811                                         return -errno;
 812                 }
 813         }
 814
 815         /* Second step: actually set the uids */
 816         if (setresuid(uid, uid, uid) < 0)
 817                 return -errno;
 818
 819         /* At this point we should have all necessary capabilities but
 820            are otherwise a normal user. However, the caps might got
 821            corrupted due to the setresuid() so we need clean them up
 822            later. This is done outside of this call. */
 823
 824         return 0;
 825 }
 826
 827 #ifdef HAVE_PAM
 828
 829 static int null_conv(
 830                 int num_msg,
 831                 const struct pam_message **msg,
 832                 struct pam_response **resp,
 833                 void *appdata_ptr) {
 834
 835         /* We don't support conversations */
 836
 837         return PAM_CONV_ERR;
 838 }
 839
 840 #endif
 841
 842 static int setup_pam(
 843                 const char *name,
 844                 const char *user,
 845                 uid_t uid,
 846                 const char *tty,
 847                 char ***env,
 848                 int fds[], unsigned n_fds) {
 849
 850 #ifdef HAVE_PAM
 851
 852         static const struct pam_conv conv = {
 853                 .conv = null_conv,
 854                 .appdata_ptr = NULL
 855         };
 856
 857         _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL;
 858         pam_handle_t *handle = NULL;
 859         sigset_t old_ss;
 860         int pam_code = PAM_SUCCESS, r;
 861         char **nv, **e = NULL;
 862         bool close_session = false;
 863         pid_t pam_pid = 0, parent_pid;
 864         int flags = 0;
 865
 866         assert(name);
 867         assert(user);
 868         assert(env);
 869
 870         /* We set up PAM in the parent process, then fork. The child
 871          * will then stay around until killed via PR_GET_PDEATHSIG or
 872          * systemd via the cgroup logic. It will then remove the PAM
 873          * session again. The parent process will exec() the actual
 874          * daemon. We do things this way to ensure that the main PID
 875          * of the daemon is the one we initially fork()ed. */
 876
 877         r = barrier_create(&barrier);
 878         if (r < 0)
 879                 goto fail;
 880
 881         if (log_get_max_level() < LOG_DEBUG)
 882                 flags |= PAM_SILENT;
 883
 884         pam_code = pam_start(name, user, &conv, &handle);
 885         if (pam_code != PAM_SUCCESS) {
 886                 handle = NULL;
 887                 goto fail;
 888         }
 889
 890         if (tty) {
 891                 pam_code = pam_set_item(handle, PAM_TTY, tty);
 892                 if (pam_code != PAM_SUCCESS)
 893                         goto fail;
 894         }
 895
 896         STRV_FOREACH(nv, *env) {
 897                 pam_code = pam_putenv(handle, *nv);
 898                 if (pam_code != PAM_SUCCESS)
 899                         goto fail;
 900         }
 901
 902         pam_code = pam_acct_mgmt(handle, flags);
 903         if (pam_code != PAM_SUCCESS)
 904                 goto fail;
 905
 906         pam_code = pam_open_session(handle, flags);
 907         if (pam_code != PAM_SUCCESS)
 908                 goto fail;
 909
 910         close_session = true;
 911
 912         e = pam_getenvlist(handle);
 913         if (!e) {
 914                 pam_code = PAM_BUF_ERR;
 915                 goto fail;
 916         }
 917
 918         /* Block SIGTERM, so that we know that it won't get lost in
 919          * the child */
 920
 921         assert_se(sigprocmask_many(SIG_BLOCK, &old_ss, SIGTERM, -1) >= 0);
 922
 923         parent_pid = getpid();
 924
 925         pam_pid = fork();
 926         if (pam_pid < 0) {
 927                 r = -errno;
 928                 goto fail;
 929         }
 930
 931         if (pam_pid == 0) {
 932                 int sig, ret = EXIT_PAM;
 933
 934                 /* The child's job is to reset the PAM session on
 935                  * termination */
 936                 barrier_set_role(&barrier, BARRIER_CHILD);
 937
 938                 /* This string must fit in 10 chars (i.e. the length
 939                  * of "/sbin/init"), to look pretty in /bin/ps */
 940                 rename_process("(sd-pam)");
 941
 942                 /* Make sure we don't keep open the passed fds in this
 943                 child. We assume that otherwise only those fds are
 944                 open here that have been opened by PAM. */
 945                 close_many(fds, n_fds);
 946
 947                 /* Drop privileges - we don't need any to pam_close_session
 948                  * and this will make PR_SET_PDEATHSIG work in most cases.
 949                  * If this fails, ignore the error - but expect sd-pam threads
 950                  * to fail to exit normally */
 951                 if (setresuid(uid, uid, uid) < 0)
 952                         log_error_errno(r, "Error: Failed to setresuid() in sd-pam: %m");
 953
 954                 (void) ignore_signals(SIGPIPE, -1);
 955
 956                 /* Wait until our parent died. This will only work if
 957                  * the above setresuid() succeeds, otherwise the kernel
 958                  * will not allow unprivileged parents kill their privileged
 959                  * children this way. We rely on the control groups kill logic
 960                  * to do the rest for us. */
 961                 if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
 962                         goto child_finish;
 963
 964                 /* Tell the parent that our setup is done. This is especially
 965                  * important regarding dropping privileges. Otherwise, unit
 966                  * setup might race against our setresuid(2) call. */
 967                 barrier_place(&barrier);
 968
 969                 /* Check if our parent process might already have
 970                  * died? */
 971                 if (getppid() == parent_pid) {
 972                         sigset_t ss;
 973
 974                         assert_se(sigemptyset(&ss) >= 0);
 975                         assert_se(sigaddset(&ss, SIGTERM) >= 0);
 976
 977                         for (;;) {
 978                                 if (sigwait(&ss, &sig) < 0) {
 979                                         if (errno == EINTR)
 980                                                 continue;
 981
 982                                         goto child_finish;
 983                                 }
 984
 985                                 assert(sig == SIGTERM);
 986                                 break;
 987                         }
 988                 }
 989
 990                 /* If our parent died we'll end the session */
 991                 if (getppid() != parent_pid) {
 992                         pam_code = pam_close_session(handle, flags);
 993                         if (pam_code != PAM_SUCCESS)
 994                                 goto child_finish;
 995                 }
 996
 997                 ret = 0;
 998
 999         child_finish:
1000                 pam_end(handle, pam_code | flags);
1001                 _exit(ret);
1002         }
1003
1004         barrier_set_role(&barrier, BARRIER_PARENT);
1005
1006         /* If the child was forked off successfully it will do all the
1007          * cleanups, so forget about the handle here. */
1008         handle = NULL;
1009
1010         /* Unblock SIGTERM again in the parent */
1011         assert_se(sigprocmask(SIG_SETMASK, &old_ss, NULL) >= 0);
1012
1013         /* We close the log explicitly here, since the PAM modules
1014          * might have opened it, but we don't want this fd around. */
1015         closelog();
1016
1017         /* Synchronously wait for the child to initialize. We don't care for
1018          * errors as we cannot recover. However, warn loudly if it happens. */
1019         if (!barrier_place_and_sync(&barrier))
1020                 log_error("PAM initialization failed");
1021
1022         strv_free(*env);
1023         *env = e;
1024
1025         return 0;
1026
1027 fail:
1028         if (pam_code != PAM_SUCCESS) {
1029                 log_error("PAM failed: %s", pam_strerror(handle, pam_code));
1030                 r = -EPERM;  /* PAM errors do not map to errno */
1031         } else
1032                 log_error_errno(r, "PAM failed: %m");
1033
1034         if (handle) {
1035                 if (close_session)
1036                         pam_code = pam_close_session(handle, flags);
1037
1038                 pam_end(handle, pam_code | flags);
1039         }
1040
1041         strv_free(e);
1042         closelog();
1043
1044         return r;
1045 #else
1046         return 0;
1047 #endif
1048 }
1049
1050 static void rename_process_from_path(const char *path) {
1051         char process_name[11];
1052         const char *p;
1053         size_t l;
1054
1055         /* This resulting string must fit in 10 chars (i.e. the length
1056          * of "/sbin/init") to look pretty in /bin/ps */
1057
1058         p = basename(path);
1059         if (isempty(p)) {
1060                 rename_process("(...)");
1061                 return;
1062         }
1063
1064         l = strlen(p);
1065         if (l > 8) {
1066                 /* The end of the process name is usually more
1067                  * interesting, since the first bit might just be
1068                  * "systemd-" */
1069                 p = p + l - 8;
1070                 l = 8;
1071         }
1072
1073         process_name[0] = '(';
1074         memcpy(process_name+1, p, l);
1075         process_name[1+l] = ')';
1076         process_name[1+l+1] = 0;
1077
1078         rename_process(process_name);
1079 }
1080
1081 #ifdef HAVE_SECCOMP
1082
1083 static bool skip_seccomp_unavailable(const Unit* u, const char* msg) {
1084         if (!is_seccomp_available()) {
1085                 log_open();
1086                 log_unit_debug(u, "SECCOMP features not detected in the kernel, skipping %s", msg);
1087                 log_close();
1088                 return true;
1089         }
1090         return false;
1091 }
1092
1093 static int apply_seccomp(const Unit* u, const ExecContext *c) {
1094         uint32_t negative_action, action;
1095         scmp_filter_ctx *seccomp;
1096         Iterator i;
1097         void *id;
1098         int r;
1099
1100         assert(c);
1101
1102         if (skip_seccomp_unavailable(u, "syscall filtering"))
1103                 return 0;
1104
1105         negative_action = c->syscall_errno == 0 ? SCMP_ACT_KILL : SCMP_ACT_ERRNO(c->syscall_errno);
1106
1107         seccomp = seccomp_init(c->syscall_whitelist ? negative_action : SCMP_ACT_ALLOW);
1108         if (!seccomp)
1109                 return -ENOMEM;
1110
1111         if (c->syscall_archs) {
1112
1113                 SET_FOREACH(id, c->syscall_archs, i) {
1114                         r = seccomp_arch_add(seccomp, PTR_TO_UINT32(id) - 1);
1115                         if (r == -EEXIST)
1116                                 continue;
1117                         if (r < 0)
1118                                 goto finish;
1119                 }
1120
1121         } else {
1122                 r = seccomp_add_secondary_archs(seccomp);
1123                 if (r < 0)
1124                         goto finish;
1125         }
1126
1127         action = c->syscall_whitelist ? SCMP_ACT_ALLOW : negative_action;
1128         SET_FOREACH(id, c->syscall_filter, i) {
1129                 r = seccomp_rule_add(seccomp, action, PTR_TO_INT(id) - 1, 0);
1130                 if (r < 0)
1131                         goto finish;
1132         }
1133
1134         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
1135         if (r < 0)
1136                 goto finish;
1137
1138         r = seccomp_load(seccomp);
1139
1140 finish:
1141         seccomp_release(seccomp);
1142         return r;
1143 }
1144
1145 static int apply_address_families(const Unit* u, const ExecContext *c) {
1146         scmp_filter_ctx *seccomp;
1147         Iterator i;
1148         int r;
1149
1150         assert(c);
1151
1152         if (skip_seccomp_unavailable(u, "RestrictAddressFamilies="))
1153                 return 0;
1154
1155         seccomp = seccomp_init(SCMP_ACT_ALLOW);
1156         if (!seccomp)
1157                 return -ENOMEM;
1158
1159         r = seccomp_add_secondary_archs(seccomp);
1160         if (r < 0)
1161                 goto finish;
1162
1163         if (c->address_families_whitelist) {
1164                 int af, first = 0, last = 0;
1165                 void *afp;
1166
1167                 /* If this is a whitelist, we first block the address
1168                  * families that are out of range and then everything
1169                  * that is not in the set. First, we find the lowest
1170                  * and highest address family in the set. */
1171
1172                 SET_FOREACH(afp, c->address_families, i) {
1173                         af = PTR_TO_INT(afp);
1174
1175                         if (af <= 0 || af >= af_max())
1176                                 continue;
1177
1178                         if (first == 0 || af < first)
1179                                 first = af;
1180
1181                         if (last == 0 || af > last)
1182                                 last = af;
1183                 }
1184
1185                 assert((first == 0) == (last == 0));
1186
1187                 if (first == 0) {
1188
1189                         /* No entries in the valid range, block everything */
1190                         r = seccomp_rule_add(
1191                                         seccomp,
1192                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1193                                         SCMP_SYS(socket),
1194                                         0);
1195                         if (r < 0)
1196                                 goto finish;
1197
1198                 } else {
1199
1200                         /* Block everything below the first entry */
1201                         r = seccomp_rule_add(
1202                                         seccomp,
1203                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1204                                         SCMP_SYS(socket),
1205                                         1,
1206                                         SCMP_A0(SCMP_CMP_LT, first));
1207                         if (r < 0)
1208                                 goto finish;
1209
1210                         /* Block everything above the last entry */
1211                         r = seccomp_rule_add(
1212                                         seccomp,
1213                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1214                                         SCMP_SYS(socket),
1215                                         1,
1216                                         SCMP_A0(SCMP_CMP_GT, last));
1217                         if (r < 0)
1218                                 goto finish;
1219
1220                         /* Block everything between the first and last
1221                          * entry */
1222                         for (af = 1; af < af_max(); af++) {
1223
1224                                 if (set_contains(c->address_families, INT_TO_PTR(af)))
1225                                         continue;
1226
1227                                 r = seccomp_rule_add(
1228                                                 seccomp,
1229                                                 SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1230                                                 SCMP_SYS(socket),
1231                                                 1,
1232                                                 SCMP_A0(SCMP_CMP_EQ, af));
1233                                 if (r < 0)
1234                                         goto finish;
1235                         }
1236                 }
1237
1238         } else {
1239                 void *af;
1240
1241                 /* If this is a blacklist, then generate one rule for
1242                  * each address family that are then combined in OR
1243                  * checks. */
1244
1245                 SET_FOREACH(af, c->address_families, i) {
1246
1247                         r = seccomp_rule_add(
1248                                         seccomp,
1249                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1250                                         SCMP_SYS(socket),
1251                                         1,
1252                                         SCMP_A0(SCMP_CMP_EQ, PTR_TO_INT(af)));
1253                         if (r < 0)
1254                                 goto finish;
1255                 }
1256         }
1257
1258         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
1259         if (r < 0)
1260                 goto finish;
1261
1262         r = seccomp_load(seccomp);
1263
1264 finish:
1265         seccomp_release(seccomp);
1266         return r;
1267 }
1268
1269 static int apply_memory_deny_write_execute(const Unit* u, const ExecContext *c) {
1270         scmp_filter_ctx *seccomp;
1271         int r;
1272
1273         assert(c);
1274
1275         if (skip_seccomp_unavailable(u, "MemoryDenyWriteExecute="))
1276                 return 0;
1277
1278         seccomp = seccomp_init(SCMP_ACT_ALLOW);
1279         if (!seccomp)
1280                 return -ENOMEM;
1281
1282         r = seccomp_add_secondary_archs(seccomp);
1283         if (r < 0)
1284                 goto finish;
1285
1286         r = seccomp_rule_add(
1287                         seccomp,
1288                         SCMP_ACT_ERRNO(EPERM),
1289                         SCMP_SYS(mmap),
1290                         1,
1291                         SCMP_A2(SCMP_CMP_MASKED_EQ, PROT_EXEC|PROT_WRITE, PROT_EXEC|PROT_WRITE));
1292         if (r < 0)
1293                 goto finish;
1294
1295         r = seccomp_rule_add(
1296                         seccomp,
1297                         SCMP_ACT_ERRNO(EPERM),
1298                         SCMP_SYS(mprotect),
1299                         1,
1300                         SCMP_A2(SCMP_CMP_MASKED_EQ, PROT_EXEC, PROT_EXEC));
1301         if (r < 0)
1302                 goto finish;
1303
1304         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
1305         if (r < 0)
1306                 goto finish;
1307
1308         r = seccomp_load(seccomp);
1309
1310 finish:
1311         seccomp_release(seccomp);
1312         return r;
1313 }
1314
1315 static int apply_restrict_realtime(const Unit* u, const ExecContext *c) {
1316         static const int permitted_policies[] = {
1317                 SCHED_OTHER,
1318                 SCHED_BATCH,
1319                 SCHED_IDLE,
1320         };
1321
1322         scmp_filter_ctx *seccomp;
1323         unsigned i;
1324         int r, p, max_policy = 0;
1325
1326         assert(c);
1327
1328         if (skip_seccomp_unavailable(u, "RestrictRealtime="))
1329                 return 0;
1330
1331         seccomp = seccomp_init(SCMP_ACT_ALLOW);
1332         if (!seccomp)
1333                 return -ENOMEM;
1334
1335         r = seccomp_add_secondary_archs(seccomp);
1336         if (r < 0)
1337                 goto finish;
1338
1339         /* Determine the highest policy constant we want to allow */
1340         for (i = 0; i < ELEMENTSOF(permitted_policies); i++)
1341                 if (permitted_policies[i] > max_policy)
1342                         max_policy = permitted_policies[i];
1343
1344         /* Go through all policies with lower values than that, and block them -- unless they appear in the
1345          * whitelist. */
1346         for (p = 0; p < max_policy; p++) {
1347                 bool good = false;
1348
1349                 /* Check if this is in the whitelist. */
1350                 for (i = 0; i < ELEMENTSOF(permitted_policies); i++)
1351                         if (permitted_policies[i] == p) {
1352                                 good = true;
1353                                 break;
1354                         }
1355
1356                 if (good)
1357                         continue;
1358
1359                 /* Deny this policy */
1360                 r = seccomp_rule_add(
1361                                 seccomp,
1362                                 SCMP_ACT_ERRNO(EPERM),
1363                                 SCMP_SYS(sched_setscheduler),
1364                                 1,
1365                                 SCMP_A1(SCMP_CMP_EQ, p));
1366                 if (r < 0)
1367                         goto finish;
1368         }
1369
1370         /* Blacklist all other policies, i.e. the ones with higher values. Note that all comparisons are unsigned here,
1371          * hence no need no check for < 0 values. */
1372         r = seccomp_rule_add(
1373                         seccomp,
1374                         SCMP_ACT_ERRNO(EPERM),
1375                         SCMP_SYS(sched_setscheduler),
1376                         1,
1377                         SCMP_A1(SCMP_CMP_GT, max_policy));
1378         if (r < 0)
1379                 goto finish;
1380
1381         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
1382         if (r < 0)
1383                 goto finish;
1384
1385         r = seccomp_load(seccomp);
1386
1387 finish:
1388         seccomp_release(seccomp);
1389         return r;
1390 }
1391
1392 static int apply_protect_sysctl(Unit *u, const ExecContext *c) {
1393         scmp_filter_ctx *seccomp;
1394         int r;
1395
1396         assert(c);
1397
1398         /* Turn off the legacy sysctl() system call. Many distributions turn this off while building the kernel, but
1399          * let's protect even those systems where this is left on in the kernel. */
1400
1401         if (skip_seccomp_unavailable(u, "ProtectKernelTunables="))
1402                 return 0;
1403
1404         seccomp = seccomp_init(SCMP_ACT_ALLOW);
1405         if (!seccomp)
1406                 return -ENOMEM;
1407
1408         r = seccomp_add_secondary_archs(seccomp);
1409         if (r < 0)
1410                 goto finish;
1411
1412         r = seccomp_rule_add(
1413                         seccomp,
1414                         SCMP_ACT_ERRNO(EPERM),
1415                         SCMP_SYS(_sysctl),
1416                         0);
1417         if (r < 0)
1418                 goto finish;
1419
1420         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
1421         if (r < 0)
1422                 goto finish;
1423
1424         r = seccomp_load(seccomp);
1425
1426 finish:
1427         seccomp_release(seccomp);
1428         return r;
1429 }
1430
1431 static int apply_private_devices(Unit *u, const ExecContext *c) {
1432         const SystemCallFilterSet *set;
1433         scmp_filter_ctx *seccomp;
1434         const char *sys;
1435         bool syscalls_found = false;
1436         int r;
1437
1438         assert(c);
1439
1440         /* If PrivateDevices= is set, also turn off iopl and all @raw-io syscalls. */
1441
1442         if (skip_seccomp_unavailable(u, "PrivateDevices="))
1443                 return 0;
1444
1445         seccomp = seccomp_init(SCMP_ACT_ALLOW);
1446         if (!seccomp)
1447                 return -ENOMEM;
1448
1449         r = seccomp_add_secondary_archs(seccomp);
1450         if (r < 0)
1451                 goto finish;
1452
1453         for (set = syscall_filter_sets; set->set_name; set++)
1454                 if (streq(set->set_name, "@raw-io")) {
1455                         syscalls_found = true;
1456                         break;
1457                 }
1458
1459         /* We should never fail here */
1460         if (!syscalls_found) {
1461                 r = -EOPNOTSUPP;
1462                 goto finish;
1463         }
1464
1465         NULSTR_FOREACH(sys, set->value) {
1466                 int id;
1467                 bool add = true;
1468
1469 #ifndef __NR_s390_pci_mmio_read
1470                 if (streq(sys, "s390_pci_mmio_read"))
1471                         add = false;
1472 #endif
1473 #ifndef __NR_s390_pci_mmio_write
1474                 if (streq(sys, "s390_pci_mmio_write"))
1475                         add = false;
1476 #endif
1477
1478                 if (!add)
1479                         continue;
1480
1481                 id = seccomp_syscall_resolve_name(sys);
1482
1483                 r = seccomp_rule_add(
1484                                 seccomp,
1485                                 SCMP_ACT_ERRNO(EPERM),
1486                                 id, 0);
1487                 if (r < 0)
1488                         goto finish;
1489         }
1490
1491         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
1492         if (r < 0)
1493                 goto finish;
1494
1495         r = seccomp_load(seccomp);
1496
1497 finish:
1498         seccomp_release(seccomp);
1499         return r;
1500 }
1501
1502 #endif
1503
1504 static void do_idle_pipe_dance(int idle_pipe[4]) {
1505         assert(idle_pipe);
1506
1507         idle_pipe[1] = safe_close(idle_pipe[1]);
1508         idle_pipe[2] = safe_close(idle_pipe[2]);
1509
1510         if (idle_pipe[0] >= 0) {
1511                 int r;
1512
1513                 r = fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT_USEC);
1514
1515                 if (idle_pipe[3] >= 0 && r == 0 /* timeout */) {
1516                         ssize_t n;
1517
1518                         /* Signal systemd that we are bored and want to continue. */
1519                         n = write(idle_pipe[3], "x", 1);
1520                         if (n > 0)
1521                                 /* Wait for systemd to react to the signal above. */
1522                                 fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT2_USEC);
1523                 }
1524
1525                 idle_pipe[0] = safe_close(idle_pipe[0]);
1526
1527         }
1528
1529         idle_pipe[3] = safe_close(idle_pipe[3]);
1530 }
1531
1532 static int build_environment(
1533                 Unit *u,
1534                 const ExecContext *c,
1535                 const ExecParameters *p,
1536                 unsigned n_fds,
1537                 const char *home,
1538                 const char *username,
1539                 const char *shell,
1540                 dev_t journal_stream_dev,
1541                 ino_t journal_stream_ino,
1542                 char ***ret) {
1543
1544         _cleanup_strv_free_ char **our_env = NULL;
1545         unsigned n_env = 0;
1546         char *x;
1547
1548         assert(c);
1549         assert(ret);
1550
1551         our_env = new0(char*, 13);
1552         if (!our_env)
1553                 return -ENOMEM;
1554
1555         if (n_fds > 0) {
1556                 _cleanup_free_ char *joined = NULL;
1557
1558                 if (asprintf(&x, "LISTEN_PID="PID_FMT, getpid()) < 0)
1559                         return -ENOMEM;
1560                 our_env[n_env++] = x;
1561
1562                 if (asprintf(&x, "LISTEN_FDS=%u", n_fds) < 0)
1563                         return -ENOMEM;
1564                 our_env[n_env++] = x;
1565
1566                 joined = strv_join(p->fd_names, ":");
1567                 if (!joined)
1568                         return -ENOMEM;
1569
1570                 x = strjoin("LISTEN_FDNAMES=", joined, NULL);
1571                 if (!x)
1572                         return -ENOMEM;
1573                 our_env[n_env++] = x;
1574         }
1575
1576         if ((p->flags & EXEC_SET_WATCHDOG) && p->watchdog_usec > 0) {
1577                 if (asprintf(&x, "WATCHDOG_PID="PID_FMT, getpid()) < 0)
1578                         return -ENOMEM;
1579                 our_env[n_env++] = x;
1580
1581                 if (asprintf(&x, "WATCHDOG_USEC="USEC_FMT, p->watchdog_usec) < 0)
1582                         return -ENOMEM;
1583                 our_env[n_env++] = x;
1584         }
1585
1586         /* If this is D-Bus, tell the nss-systemd module, since it relies on being able to use D-Bus look up dynamic
1587          * users via PID 1, possibly dead-locking the dbus daemon. This way it will not use D-Bus to resolve names, but
1588          * check the database directly. */
1589         if (unit_has_name(u, SPECIAL_DBUS_SERVICE)) {
1590                 x = strdup("SYSTEMD_NSS_BYPASS_BUS=1");
1591                 if (!x)
1592                         return -ENOMEM;
1593                 our_env[n_env++] = x;
1594         }
1595
1596         if (home) {
1597                 x = strappend("HOME=", home);
1598                 if (!x)
1599                         return -ENOMEM;
1600                 our_env[n_env++] = x;
1601         }
1602
1603         if (username) {
1604                 x = strappend("LOGNAME=", username);
1605                 if (!x)
1606                         return -ENOMEM;
1607                 our_env[n_env++] = x;
1608
1609                 x = strappend("USER=", username);
1610                 if (!x)
1611                         return -ENOMEM;
1612                 our_env[n_env++] = x;
1613         }
1614
1615         if (shell) {
1616                 x = strappend("SHELL=", shell);
1617                 if (!x)
1618                         return -ENOMEM;
1619                 our_env[n_env++] = x;
1620         }
1621
1622         if (exec_context_needs_term(c)) {
1623                 const char *tty_path, *term = NULL;
1624
1625                 tty_path = exec_context_tty_path(c);
1626
1627                 /* If we are forked off PID 1 and we are supposed to operate on /dev/console, then let's try to inherit
1628                  * the $TERM set for PID 1. This is useful for containers so that the $TERM the container manager
1629                  * passes to PID 1 ends up all the way in the console login shown. */
1630
1631                 if (path_equal(tty_path, "/dev/console") && getppid() == 1)
1632                         term = getenv("TERM");
1633                 if (!term)
1634                         term = default_term_for_tty(tty_path);
1635
1636                 x = strappend("TERM=", term);
1637                 if (!x)
1638                         return -ENOMEM;
1639                 our_env[n_env++] = x;
1640         }
1641
1642         if (journal_stream_dev != 0 && journal_stream_ino != 0) {
1643                 if (asprintf(&x, "JOURNAL_STREAM=" DEV_FMT ":" INO_FMT, journal_stream_dev, journal_stream_ino) < 0)
1644                         return -ENOMEM;
1645
1646                 our_env[n_env++] = x;
1647         }
1648
1649         our_env[n_env++] = NULL;
1650         assert(n_env <= 12);
1651
1652         *ret = our_env;
1653         our_env = NULL;
1654
1655         return 0;
1656 }
1657
1658 static int build_pass_environment(const ExecContext *c, char ***ret) {
1659         _cleanup_strv_free_ char **pass_env = NULL;
1660         size_t n_env = 0, n_bufsize = 0;
1661         char **i;
1662
1663         STRV_FOREACH(i, c->pass_environment) {
1664                 _cleanup_free_ char *x = NULL;
1665                 char *v;
1666
1667                 v = getenv(*i);
1668                 if (!v)
1669                         continue;
1670                 x = strjoin(*i, "=", v, NULL);
1671                 if (!x)
1672                         return -ENOMEM;
1673                 if (!GREEDY_REALLOC(pass_env, n_bufsize, n_env + 2))
1674                         return -ENOMEM;
1675                 pass_env[n_env++] = x;
1676                 pass_env[n_env] = NULL;
1677                 x = NULL;
1678         }
1679
1680         *ret = pass_env;
1681         pass_env = NULL;
1682
1683         return 0;
1684 }
1685
1686 static bool exec_needs_mount_namespace(
1687                 const ExecContext *context,
1688                 const ExecParameters *params,
1689                 ExecRuntime *runtime) {
1690
1691         assert(context);
1692         assert(params);
1693
1694         if (!strv_isempty(context->read_write_paths) ||
1695             !strv_isempty(context->read_only_paths) ||
1696             !strv_isempty(context->inaccessible_paths))
1697                 return true;
1698
1699         if (context->mount_flags != 0)
1700                 return true;
1701
1702         if (context->private_tmp && runtime && (runtime->tmp_dir || runtime->var_tmp_dir))
1703                 return true;
1704
1705         if (context->private_devices ||
1706             context->protect_system != PROTECT_SYSTEM_NO ||
1707             context->protect_home != PROTECT_HOME_NO ||
1708             context->protect_kernel_tunables ||
1709             context->protect_control_groups)
1710                 return true;
1711
1712         return false;
1713 }
1714
1715 static int setup_private_users(uid_t uid, gid_t gid) {
1716         _cleanup_free_ char *uid_map = NULL, *gid_map = NULL;
1717         _cleanup_close_pair_ int errno_pipe[2] = { -1, -1 };
1718         _cleanup_close_ int unshare_ready_fd = -1;
1719         _cleanup_(sigkill_waitp) pid_t pid = 0;
1720         uint64_t c = 1;
1721         siginfo_t si;
1722         ssize_t n;
1723         int r;
1724
1725         /* Set up a user namespace and map root to root, the selected UID/GID to itself, and everything else to
1726          * nobody. In order to be able to write this mapping we need CAP_SETUID in the original user namespace, which
1727          * we however lack after opening the user namespace. To work around this we fork() a temporary child process,
1728          * which waits for the parent to create the new user namespace while staying in the original namespace. The
1729          * child then writes the UID mapping, under full privileges. The parent waits for the child to finish and
1730          * continues execution normally. */
1731
1732         if (uid != 0 && uid_is_valid(uid))
1733                 asprintf(&uid_map,
1734                          "0 0 1\n"                      /* Map root → root */
1735                          UID_FMT " " UID_FMT " 1\n",    /* Map $UID → $UID */
1736                          uid, uid);                     /* The case where the above is the same */
1737         else
1738                 uid_map = strdup("0 0 1\n");
1739         if (!uid_map)
1740                 return -ENOMEM;
1741
1742         if (gid != 0 && gid_is_valid(gid))
1743                 asprintf(&gid_map,
1744                          "0 0 1\n"                      /* Map root → root */
1745                          GID_FMT " " GID_FMT " 1\n",    /* Map $GID → $GID */
1746                          gid, gid);
1747         else
1748                 gid_map = strdup("0 0 1\n");            /* The case where the above is the same */
1749         if (!gid_map)
1750                 return -ENOMEM;
1751
1752         /* Create a communication channel so that the parent can tell the child when it finished creating the user
1753          * namespace. */
1754         unshare_ready_fd = eventfd(0, EFD_CLOEXEC);
1755         if (unshare_ready_fd < 0)
1756                 return -errno;
1757
1758         /* Create a communication channel so that the child can tell the parent a proper error code in case it
1759          * failed. */
1760         if (pipe2(errno_pipe, O_CLOEXEC) < 0)
1761                 return -errno;
1762
1763         pid = fork();
1764         if (pid < 0)
1765                 return -errno;
1766
1767         if (pid == 0) {
1768                 _cleanup_close_ int fd = -1;
1769                 const char *a;
1770                 pid_t ppid;
1771
1772                 /* Child process, running in the original user namespace. Let's update the parent's UID/GID map from
1773                  * here, after the parent opened its own user namespace. */
1774
1775                 ppid = getppid();
1776                 errno_pipe[0] = safe_close(errno_pipe[0]);
1777
1778                 /* Wait until the parent unshared the user namespace */
1779                 if (read(unshare_ready_fd, &c, sizeof(c)) < 0) {
1780                         r = -errno;
1781                         goto child_fail;
1782                 }
1783
1784                 /* Disable the setgroups() system call in the child user namespace, for good. */
1785                 a = procfs_file_alloca(ppid, "setgroups");
1786                 fd = open(a, O_WRONLY|O_CLOEXEC);
1787                 if (fd < 0) {
1788                         if (errno != ENOENT) {
1789                                 r = -errno;
1790                                 goto child_fail;
1791                         }
1792
1793                         /* If the file is missing the kernel is too old, let's continue anyway. */
1794                 } else {
1795                         if (write(fd, "deny\n", 5) < 0) {
1796                                 r = -errno;
1797                                 goto child_fail;
1798                         }
1799
1800                         fd = safe_close(fd);
1801                 }
1802
1803                 /* First write the GID map */
1804                 a = procfs_file_alloca(ppid, "gid_map");
1805                 fd = open(a, O_WRONLY|O_CLOEXEC);
1806                 if (fd < 0) {
1807                         r = -errno;
1808                         goto child_fail;
1809                 }
1810                 if (write(fd, gid_map, strlen(gid_map)) < 0) {
1811                         r = -errno;
1812                         goto child_fail;
1813                 }
1814                 fd = safe_close(fd);
1815
1816                 /* The write the UID map */
1817                 a = procfs_file_alloca(ppid, "uid_map");
1818                 fd = open(a, O_WRONLY|O_CLOEXEC);
1819                 if (fd < 0) {
1820                         r = -errno;
1821                         goto child_fail;
1822                 }
1823                 if (write(fd, uid_map, strlen(uid_map)) < 0) {
1824                         r = -errno;
1825                         goto child_fail;
1826                 }
1827
1828                 _exit(EXIT_SUCCESS);
1829
1830         child_fail:
1831                 (void) write(errno_pipe[1], &r, sizeof(r));
1832                 _exit(EXIT_FAILURE);
1833         }
1834
1835         errno_pipe[1] = safe_close(errno_pipe[1]);
1836
1837         if (unshare(CLONE_NEWUSER) < 0)
1838                 return -errno;
1839
1840         /* Let the child know that the namespace is ready now */
1841         if (write(unshare_ready_fd, &c, sizeof(c)) < 0)
1842                 return -errno;
1843
1844         /* Try to read an error code from the child */
1845         n = read(errno_pipe[0], &r, sizeof(r));
1846         if (n < 0)
1847                 return -errno;
1848         if (n == sizeof(r)) { /* an error code was sent to us */
1849                 if (r < 0)
1850                         return r;
1851                 return -EIO;
1852         }
1853         if (n != 0) /* on success we should have read 0 bytes */
1854                 return -EIO;
1855
1856         r = wait_for_terminate(pid, &si);
1857         if (r < 0)
1858                 return r;
1859         pid = 0;
1860
1861         /* If something strange happened with the child, let's consider this fatal, too */
1862         if (si.si_code != CLD_EXITED || si.si_status != 0)
1863                 return -EIO;
1864
1865         return 0;
1866 }
1867
1868 static int setup_runtime_directory(
1869                 const ExecContext *context,
1870                 const ExecParameters *params,
1871                 uid_t uid,
1872                 gid_t gid) {
1873
1874         char **rt;
1875         int r;
1876
1877         assert(context);
1878         assert(params);
1879
1880         STRV_FOREACH(rt, context->runtime_directory) {
1881                 _cleanup_free_ char *p;
1882
1883                 p = strjoin(params->runtime_prefix, "/", *rt, NULL);
1884                 if (!p)
1885                         return -ENOMEM;
1886
1887                 r = mkdir_p_label(p, context->runtime_directory_mode);
1888                 if (r < 0)
1889                         return r;
1890
1891                 r = chmod_and_chown(p, context->runtime_directory_mode, uid, gid);
1892                 if (r < 0)
1893                         return r;
1894         }
1895
1896         return 0;
1897 }
1898
1899 static int setup_smack(
1900                 const ExecContext *context,
1901                 const ExecCommand *command) {
1902
1903 #ifdef HAVE_SMACK
1904         int r;
1905
1906         assert(context);
1907         assert(command);
1908
1909         if (!mac_smack_use())
1910                 return 0;
1911
1912         if (context->smack_process_label) {
1913                 r = mac_smack_apply_pid(0, context->smack_process_label);
1914                 if (r < 0)
1915                         return r;
1916         }
1917 #ifdef SMACK_DEFAULT_PROCESS_LABEL
1918         else {
1919                 _cleanup_free_ char *exec_label = NULL;
1920
1921                 r = mac_smack_read(command->path, SMACK_ATTR_EXEC, &exec_label);
1922                 if (r < 0 && r != -ENODATA && r != -EOPNOTSUPP)
1923                         return r;
1924
1925                 r = mac_smack_apply_pid(0, exec_label ? : SMACK_DEFAULT_PROCESS_LABEL);
1926                 if (r < 0)
1927                         return r;
1928         }
1929 #endif
1930 #endif
1931
1932         return 0;
1933 }
1934
1935 static int compile_read_write_paths(
1936                 const ExecContext *context,
1937                 const ExecParameters *params,
1938                 char ***ret) {
1939
1940         _cleanup_strv_free_ char **l = NULL;
1941         char **rt;
1942
1943         /* Compile the list of writable paths. This is the combination of the explicitly configured paths, plus all
1944          * runtime directories. */
1945
1946         if (strv_isempty(context->read_write_paths) &&
1947             strv_isempty(context->runtime_directory)) {
1948                 *ret = NULL; /* NOP if neither is set */
1949                 return 0;
1950         }
1951
1952         l = strv_copy(context->read_write_paths);
1953         if (!l)
1954                 return -ENOMEM;
1955
1956         STRV_FOREACH(rt, context->runtime_directory) {
1957                 char *s;
1958
1959                 s = strjoin(params->runtime_prefix, "/", *rt, NULL);
1960                 if (!s)
1961                         return -ENOMEM;
1962
1963                 if (strv_consume(&l, s) < 0)
1964                         return -ENOMEM;
1965         }
1966
1967         *ret = l;
1968         l = NULL;
1969
1970         return 0;
1971 }
1972
1973 static void append_socket_pair(int *array, unsigned *n, int pair[2]) {
1974         assert(array);
1975         assert(n);
1976
1977         if (!pair)
1978                 return;
1979
1980         if (pair[0] >= 0)
1981                 array[(*n)++] = pair[0];
1982         if (pair[1] >= 0)
1983                 array[(*n)++] = pair[1];
1984 }
1985
1986 static int close_remaining_fds(
1987                 const ExecParameters *params,
1988                 ExecRuntime *runtime,
1989                 DynamicCreds *dcreds,
1990                 int user_lookup_fd,
1991                 int socket_fd,
1992                 int *fds, unsigned n_fds) {
1993
1994         unsigned n_dont_close = 0;
1995         int dont_close[n_fds + 12];
1996
1997         assert(params);
1998
1999         if (params->stdin_fd >= 0)
2000                 dont_close[n_dont_close++] = params->stdin_fd;
2001         if (params->stdout_fd >= 0)
2002                 dont_close[n_dont_close++] = params->stdout_fd;
2003         if (params->stderr_fd >= 0)
2004                 dont_close[n_dont_close++] = params->stderr_fd;
2005
2006         if (socket_fd >= 0)
2007                 dont_close[n_dont_close++] = socket_fd;
2008         if (n_fds > 0) {
2009                 memcpy(dont_close + n_dont_close, fds, sizeof(int) * n_fds);
2010                 n_dont_close += n_fds;
2011         }
2012
2013         if (runtime)
2014                 append_socket_pair(dont_close, &n_dont_close, runtime->netns_storage_socket);
2015
2016         if (dcreds) {
2017                 if (dcreds->user)
2018                         append_socket_pair(dont_close, &n_dont_close, dcreds->user->storage_socket);
2019                 if (dcreds->group)
2020                         append_socket_pair(dont_close, &n_dont_close, dcreds->group->storage_socket);
2021         }
2022
2023         if (user_lookup_fd >= 0)
2024                 dont_close[n_dont_close++] = user_lookup_fd;
2025
2026         return close_all_fds(dont_close, n_dont_close);
2027 }
2028
2029 static bool context_has_address_families(const ExecContext *c) {
2030         assert(c);
2031
2032         return c->address_families_whitelist ||
2033                 !set_isempty(c->address_families);
2034 }
2035
2036 static bool context_has_syscall_filters(const ExecContext *c) {
2037         assert(c);
2038
2039         return c->syscall_whitelist ||
2040                 !set_isempty(c->syscall_filter) ||
2041                 !set_isempty(c->syscall_archs);
2042 }
2043
2044 static bool context_has_no_new_privileges(const ExecContext *c) {
2045         assert(c);
2046
2047         if (c->no_new_privileges)
2048                 return true;
2049
2050         if (have_effective_cap(CAP_SYS_ADMIN)) /* if we are privileged, we don't need NNP */
2051                 return false;
2052
2053         return context_has_address_families(c) || /* we need NNP if we have any form of seccomp and are unprivileged */
2054                 c->memory_deny_write_execute ||
2055                 c->restrict_realtime ||
2056                 c->protect_kernel_tunables ||
2057                 context_has_syscall_filters(c);
2058 }
2059
2060 static int send_user_lookup(
2061                 Unit *unit,
2062                 int user_lookup_fd,
2063                 uid_t uid,
2064                 gid_t gid) {
2065
2066         assert(unit);
2067
2068         /* Send the resolved UID/GID to PID 1 after we learnt it. We send a single datagram, containing the UID/GID
2069          * data as well as the unit name. Note that we suppress sending this if no user/group to resolve was
2070          * specified. */
2071
2072         if (user_lookup_fd < 0)
2073                 return 0;
2074
2075         if (!uid_is_valid(uid) && !gid_is_valid(gid))
2076                 return 0;
2077
2078         if (writev(user_lookup_fd,
2079                (struct iovec[]) {
2080                            { .iov_base = &uid, .iov_len = sizeof(uid) },
2081                            { .iov_base = &gid, .iov_len = sizeof(gid) },
2082                            { .iov_base = unit->id, .iov_len = strlen(unit->id) }}, 3) < 0)
2083                 return -errno;
2084
2085         return 0;
2086 }
2087
2088 static int exec_child(
2089                 Unit *unit,
2090                 ExecCommand *command,
2091                 const ExecContext *context,
2092                 const ExecParameters *params,
2093                 ExecRuntime *runtime,
2094                 DynamicCreds *dcreds,
2095                 char **argv,
2096                 int socket_fd,
2097                 int *fds, unsigned n_fds,
2098                 char **files_env,
2099                 int user_lookup_fd,
2100                 int *exit_status) {
2101
2102         _cleanup_strv_free_ char **our_env = NULL, **pass_env = NULL, **accum_env = NULL, **final_argv = NULL;
2103         _cleanup_free_ char *mac_selinux_context_net = NULL;
2104         const char *username = NULL, *home = NULL, *shell = NULL, *wd;
2105         dev_t journal_stream_dev = 0;
2106         ino_t journal_stream_ino = 0;
2107         bool needs_mount_namespace;
2108         uid_t uid = UID_INVALID;
2109         gid_t gid = GID_INVALID;
2110         int i, r;
2111
2112         assert(unit);
2113         assert(command);
2114         assert(context);
2115         assert(params);
2116         assert(exit_status);
2117
2118         rename_process_from_path(command->path);
2119
2120         /* We reset exactly these signals, since they are the
2121          * only ones we set to SIG_IGN in the main daemon. All
2122          * others we leave untouched because we set them to
2123          * SIG_DFL or a valid handler initially, both of which
2124          * will be demoted to SIG_DFL. */
2125         (void) default_signals(SIGNALS_CRASH_HANDLER,
2126                                SIGNALS_IGNORE, -1);
2127
2128         if (context->ignore_sigpipe)
2129                 (void) ignore_signals(SIGPIPE, -1);
2130
2131         r = reset_signal_mask();
2132         if (r < 0) {
2133                 *exit_status = EXIT_SIGNAL_MASK;
2134                 return r;
2135         }
2136
2137         if (params->idle_pipe)
2138                 do_idle_pipe_dance(params->idle_pipe);
2139
2140         /* Close sockets very early to make sure we don't
2141          * block init reexecution because it cannot bind its
2142          * sockets */
2143
2144         log_forget_fds();
2145
2146         r = close_remaining_fds(params, runtime, dcreds, user_lookup_fd, socket_fd, fds, n_fds);
2147         if (r < 0) {
2148                 *exit_status = EXIT_FDS;
2149                 return r;
2150         }
2151
2152         if (!context->same_pgrp)
2153                 if (setsid() < 0) {
2154                         *exit_status = EXIT_SETSID;
2155                         return -errno;
2156                 }
2157
2158         exec_context_tty_reset(context, params);
2159
2160         if (params->flags & EXEC_CONFIRM_SPAWN) {
2161                 char response;
2162
2163                 r = ask_for_confirmation(&response, argv);
2164                 if (r == -ETIMEDOUT)
2165                         write_confirm_message("Confirmation question timed out, assuming positive response.\n");
2166                 else if (r < 0)
2167                         write_confirm_message("Couldn't ask confirmation question, assuming positive response: %s\n", strerror(-r));
2168                 else if (response == 's') {
2169                         write_confirm_message("Skipping execution.\n");
2170                         *exit_status = EXIT_CONFIRM;
2171                         return -ECANCELED;
2172                 } else if (response == 'n') {
2173                         write_confirm_message("Failing execution.\n");
2174                         *exit_status = 0;
2175                         return 0;
2176                 }
2177         }
2178
2179         if (context->dynamic_user && dcreds) {
2180
2181                 /* Make sure we bypass our own NSS module for any NSS checks */
2182                 if (putenv((char*) "SYSTEMD_NSS_DYNAMIC_BYPASS=1") != 0) {
2183                         *exit_status = EXIT_USER;
2184                         return -errno;
2185                 }
2186
2187                 r = dynamic_creds_realize(dcreds, &uid, &gid);
2188                 if (r < 0) {
2189                         *exit_status = EXIT_USER;
2190                         return r;
2191                 }
2192
2193                 if (!uid_is_valid(uid) || !gid_is_valid(gid)) {
2194                         *exit_status = EXIT_USER;
2195                         return -ESRCH;
2196                 }
2197
2198                 if (dcreds->user)
2199                         username = dcreds->user->name;
2200
2201         } else {
2202                 if (context->user) {
2203                         username = context->user;
2204                         r = get_user_creds_clean(&username, &uid, &gid, &home, &shell);
2205                         if (r < 0) {
2206                                 *exit_status = EXIT_USER;
2207                                 return r;
2208                         }
2209
2210                         /* Note that we don't set $HOME or $SHELL if they are not particularly enlightening anyway
2211                          * (i.e. are "/" or "/bin/nologin"). */
2212                 }
2213
2214                 if (context->group) {
2215                         const char *g = context->group;
2216
2217                         r = get_group_creds(&g, &gid);
2218                         if (r < 0) {
2219                                 *exit_status = EXIT_GROUP;
2220                                 return r;
2221                         }
2222                 }
2223         }
2224
2225         r = send_user_lookup(unit, user_lookup_fd, uid, gid);
2226         if (r < 0) {
2227                 *exit_status = EXIT_USER;
2228                 return r;
2229         }
2230
2231         user_lookup_fd = safe_close(user_lookup_fd);
2232
2233         /* If a socket is connected to STDIN/STDOUT/STDERR, we
2234          * must sure to drop O_NONBLOCK */
2235         if (socket_fd >= 0)
2236                 (void) fd_nonblock(socket_fd, false);
2237
2238         r = setup_input(context, params, socket_fd);
2239         if (r < 0) {
2240                 *exit_status = EXIT_STDIN;
2241                 return r;
2242         }
2243
2244         r = setup_output(unit, context, params, STDOUT_FILENO, socket_fd, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
2245         if (r < 0) {
2246                 *exit_status = EXIT_STDOUT;
2247                 return r;
2248         }
2249
2250         r = setup_output(unit, context, params, STDERR_FILENO, socket_fd, basename(command->path), uid, gid, &journal_stream_dev, &journal_stream_ino);
2251         if (r < 0) {
2252                 *exit_status = EXIT_STDERR;
2253                 return r;
2254         }
2255
2256         if (params->cgroup_path) {
2257                 r = cg_attach_everywhere(params->cgroup_supported, params->cgroup_path, 0, NULL, NULL);
2258                 if (r < 0) {
2259                         *exit_status = EXIT_CGROUP;
2260                         return r;
2261                 }
2262         }
2263
2264         if (context->oom_score_adjust_set) {
2265                 char t[DECIMAL_STR_MAX(context->oom_score_adjust)];
2266
2267                 /* When we can't make this change due to EPERM, then
2268                  * let's silently skip over it. User namespaces
2269                  * prohibit write access to this file, and we
2270                  * shouldn't trip up over that. */
2271
2272                 sprintf(t, "%i", context->oom_score_adjust);
2273                 r = write_string_file("/proc/self/oom_score_adj", t, 0);
2274                 if (r == -EPERM || r == -EACCES) {
2275                         log_open();
2276                         log_unit_debug_errno(unit, r, "Failed to adjust OOM setting, assuming containerized execution, ignoring: %m");
2277                         log_close();
2278                 } else if (r < 0) {
2279                         *exit_status = EXIT_OOM_ADJUST;
2280                         return -errno;
2281                 }
2282         }
2283
2284         if (context->nice_set)
2285                 if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
2286                         *exit_status = EXIT_NICE;
2287                         return -errno;
2288                 }
2289
2290         if (context->cpu_sched_set) {
2291                 struct sched_param param = {
2292                         .sched_priority = context->cpu_sched_priority,
2293                 };
2294
2295                 r = sched_setscheduler(0,
2296                                        context->cpu_sched_policy |
2297                                        (context->cpu_sched_reset_on_fork ?
2298                                         SCHED_RESET_ON_FORK : 0),
2299                                        &param);
2300                 if (r < 0) {
2301                         *exit_status = EXIT_SETSCHEDULER;
2302                         return -errno;
2303                 }
2304         }
2305
2306         if (context->cpuset)
2307                 if (sched_setaffinity(0, CPU_ALLOC_SIZE(context->cpuset_ncpus), context->cpuset) < 0) {
2308                         *exit_status = EXIT_CPUAFFINITY;
2309                         return -errno;
2310                 }
2311
2312         if (context->ioprio_set)
2313                 if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {
2314                         *exit_status = EXIT_IOPRIO;
2315                         return -errno;
2316                 }
2317
2318         if (context->timer_slack_nsec != NSEC_INFINITY)
2319                 if (prctl(PR_SET_TIMERSLACK, context->timer_slack_nsec) < 0) {
2320                         *exit_status = EXIT_TIMERSLACK;
2321                         return -errno;
2322                 }
2323
2324         if (context->personality != PERSONALITY_INVALID)
2325                 if (personality(context->personality) < 0) {
2326                         *exit_status = EXIT_PERSONALITY;
2327                         return -errno;
2328                 }
2329
2330         if (context->utmp_id)
2331                 utmp_put_init_process(context->utmp_id, getpid(), getsid(0), context->tty_path,
2332                                       context->utmp_mode == EXEC_UTMP_INIT  ? INIT_PROCESS :
2333                                       context->utmp_mode == EXEC_UTMP_LOGIN ? LOGIN_PROCESS :
2334                                       USER_PROCESS,
2335                                       username ? "root" : context->user);
2336
2337         if (context->user && is_terminal_input(context->std_input)) {
2338                 r = chown_terminal(STDIN_FILENO, uid);
2339                 if (r < 0) {
2340                         *exit_status = EXIT_STDIN;
2341                         return r;
2342                 }
2343         }
2344
2345         /* If delegation is enabled we'll pass ownership of the cgroup
2346          * (but only in systemd's own controller hierarchy!) to the
2347          * user of the new process. */
2348         if (params->cgroup_path && context->user && params->cgroup_delegate) {
2349                 r = cg_set_task_access(SYSTEMD_CGROUP_CONTROLLER, params->cgroup_path, 0644, uid, gid);
2350                 if (r < 0) {
2351                         *exit_status = EXIT_CGROUP;
2352                         return r;
2353                 }
2354
2355
2356                 r = cg_set_group_access(SYSTEMD_CGROUP_CONTROLLER, params->cgroup_path, 0755, uid, gid);
2357                 if (r < 0) {
2358                         *exit_status = EXIT_CGROUP;
2359                         return r;
2360                 }
2361         }
2362
2363         if (!strv_isempty(context->runtime_directory) && params->runtime_prefix) {
2364                 r = setup_runtime_directory(context, params, uid, gid);
2365                 if (r < 0) {
2366                         *exit_status = EXIT_RUNTIME_DIRECTORY;
2367                         return r;
2368                 }
2369         }
2370
2371         r = build_environment(
2372                         unit,
2373                         context,
2374                         params,
2375                         n_fds,
2376                         home,
2377                         username,
2378                         shell,
2379                         journal_stream_dev,
2380                         journal_stream_ino,
2381                         &our_env);
2382         if (r < 0) {
2383                 *exit_status = EXIT_MEMORY;
2384                 return r;
2385         }
2386
2387         r = build_pass_environment(context, &pass_env);
2388         if (r < 0) {
2389                 *exit_status = EXIT_MEMORY;
2390                 return r;
2391         }
2392
2393         accum_env = strv_env_merge(5,
2394                                    params->environment,
2395                                    our_env,
2396                                    pass_env,
2397                                    context->environment,
2398                                    files_env,
2399                                    NULL);
2400         if (!accum_env) {
2401                 *exit_status = EXIT_MEMORY;
2402                 return -ENOMEM;
2403         }
2404         accum_env = strv_env_clean(accum_env);
2405
2406         (void) umask(context->umask);
2407
2408         if ((params->flags & EXEC_APPLY_PERMISSIONS) && !command->privileged) {
2409                 r = setup_smack(context, command);
2410                 if (r < 0) {
2411                         *exit_status = EXIT_SMACK_PROCESS_LABEL;
2412                         return r;
2413                 }
2414
2415                 if (context->pam_name && username) {
2416                         r = setup_pam(context->pam_name, username, uid, context->tty_path, &accum_env, fds, n_fds);
2417                         if (r < 0) {
2418                                 *exit_status = EXIT_PAM;
2419                                 return r;
2420                         }
2421                 }
2422         }
2423
2424         if (context->private_network && runtime && runtime->netns_storage_socket[0] >= 0) {
2425                 r = setup_netns(runtime->netns_storage_socket);
2426                 if (r < 0) {
2427                         *exit_status = EXIT_NETWORK;
2428                         return r;
2429                 }
2430         }
2431
2432         needs_mount_namespace = exec_needs_mount_namespace(context, params, runtime);
2433         if (needs_mount_namespace) {
2434                 _cleanup_free_ char **rw = NULL;
2435                 char *tmp = NULL, *var = NULL;
2436
2437                 /* The runtime struct only contains the parent
2438                  * of the private /tmp, which is
2439                  * non-accessible to world users. Inside of it
2440                  * there's a /tmp that is sticky, and that's
2441                  * the one we want to use here. */
2442
2443                 if (context->private_tmp && runtime) {
2444                         if (runtime->tmp_dir)
2445                                 tmp = strjoina(runtime->tmp_dir, "/tmp");
2446                         if (runtime->var_tmp_dir)
2447                                 var = strjoina(runtime->var_tmp_dir, "/tmp");
2448                 }
2449
2450                 r = compile_read_write_paths(context, params, &rw);
2451                 if (r < 0) {
2452                         *exit_status = EXIT_NAMESPACE;
2453                         return r;
2454                 }
2455
2456                 r = setup_namespace(
2457                                 (params->flags & EXEC_APPLY_CHROOT) ? context->root_directory : NULL,
2458                                 rw,
2459                                 context->read_only_paths,
2460                                 context->inaccessible_paths,
2461                                 tmp,
2462                                 var,
2463                                 context->private_devices,
2464                                 context->protect_kernel_tunables,
2465                                 context->protect_control_groups,
2466                                 context->protect_home,
2467                                 context->protect_system,
2468                                 context->mount_flags);
2469
2470                 /* If we couldn't set up the namespace this is
2471                  * probably due to a missing capability. In this case,
2472                  * silently proceeed. */
2473                 if (r == -EPERM || r == -EACCES) {
2474                         log_open();
2475                         log_unit_debug_errno(unit, r, "Failed to set up namespace, assuming containerized execution, ignoring: %m");
2476                         log_close();
2477                 } else if (r < 0) {
2478                         *exit_status = EXIT_NAMESPACE;
2479                         return r;
2480                 }
2481         }
2482
2483         if ((params->flags & EXEC_APPLY_PERMISSIONS) && !command->privileged) {
2484                 r = enforce_groups(context, username, gid);
2485                 if (r < 0) {
2486                         *exit_status = EXIT_GROUP;
2487                         return r;
2488                 }
2489         }
2490
2491         if (context->working_directory_home)
2492                 wd = home;
2493         else if (context->working_directory)
2494                 wd = context->working_directory;
2495         else
2496                 wd = "/";
2497
2498         if (params->flags & EXEC_APPLY_CHROOT) {
2499                 if (!needs_mount_namespace && context->root_directory)
2500                         if (chroot(context->root_directory) < 0) {
2501                                 *exit_status = EXIT_CHROOT;
2502                                 return -errno;
2503                         }
2504
2505                 if (chdir(wd) < 0 &&
2506                     !context->working_directory_missing_ok) {
2507                         *exit_status = EXIT_CHDIR;
2508                         return -errno;
2509                 }
2510         } else {
2511                 const char *d;
2512
2513                 d = strjoina(strempty(context->root_directory), "/", strempty(wd));
2514                 if (chdir(d) < 0 &&
2515                     !context->working_directory_missing_ok) {
2516                         *exit_status = EXIT_CHDIR;
2517                         return -errno;
2518                 }
2519         }
2520
2521 #ifdef HAVE_SELINUX
2522         if ((params->flags & EXEC_APPLY_PERMISSIONS) &&
2523             mac_selinux_use() &&
2524             params->selinux_context_net &&
2525             socket_fd >= 0 &&
2526             !command->privileged) {
2527
2528                 r = mac_selinux_get_child_mls_label(socket_fd, command->path, context->selinux_context, &mac_selinux_context_net);
2529                 if (r < 0) {
2530                         *exit_status = EXIT_SELINUX_CONTEXT;
2531                         return r;
2532                 }
2533         }
2534 #endif
2535
2536         if ((params->flags & EXEC_APPLY_PERMISSIONS) && context->private_users) {
2537                 r = setup_private_users(uid, gid);
2538                 if (r < 0) {
2539                         *exit_status = EXIT_USER;
2540                         return r;
2541                 }
2542         }
2543
2544         /* We repeat the fd closing here, to make sure that
2545          * nothing is leaked from the PAM modules. Note that
2546          * we are more aggressive this time since socket_fd
2547          * and the netns fds we don't need anymore. The custom
2548          * endpoint fd was needed to upload the policy and can
2549          * now be closed as well. */
2550         r = close_all_fds(fds, n_fds);
2551         if (r >= 0)
2552                 r = shift_fds(fds, n_fds);
2553         if (r >= 0)
2554                 r = flags_fds(fds, n_fds, context->non_blocking);
2555         if (r < 0) {
2556                 *exit_status = EXIT_FDS;
2557                 return r;
2558         }
2559
2560         if ((params->flags & EXEC_APPLY_PERMISSIONS) && !command->privileged) {
2561
2562                 int secure_bits = context->secure_bits;
2563
2564                 for (i = 0; i < _RLIMIT_MAX; i++) {
2565
2566                         if (!context->rlimit[i])
2567                                 continue;
2568
2569                         r = setrlimit_closest(i, context->rlimit[i]);
2570                         if (r < 0) {
2571                                 *exit_status = EXIT_LIMITS;
2572                                 return r;
2573                         }
2574                 }
2575
2576                 /* Set the RTPRIO resource limit to 0, but only if nothing else was explicitly requested. */
2577                 if (context->restrict_realtime && !context->rlimit[RLIMIT_RTPRIO]) {
2578                         if (setrlimit(RLIMIT_RTPRIO, &RLIMIT_MAKE_CONST(0)) < 0) {
2579                                 *exit_status = EXIT_LIMITS;
2580                                 return -errno;
2581                         }
2582                 }
2583
2584                 if (!cap_test_all(context->capability_bounding_set)) {
2585                         r = capability_bounding_set_drop(context->capability_bounding_set, false);
2586                         if (r < 0) {
2587                                 *exit_status = EXIT_CAPABILITIES;
2588                                 return r;
2589                         }
2590                 }
2591
2592                 /* This is done before enforce_user, but ambient set
2593                  * does not survive over setresuid() if keep_caps is not set. */
2594                 if (context->capability_ambient_set != 0) {
2595                         r = capability_ambient_set_apply(context->capability_ambient_set, true);
2596                         if (r < 0) {
2597                                 *exit_status = EXIT_CAPABILITIES;
2598                                 return r;
2599                         }
2600                 }
2601
2602                 if (context->user) {
2603                         r = enforce_user(context, uid);
2604                         if (r < 0) {
2605                                 *exit_status = EXIT_USER;
2606                                 return r;
2607                         }
2608                         if (context->capability_ambient_set != 0) {
2609
2610                                 /* Fix the ambient capabilities after user change. */
2611                                 r = capability_ambient_set_apply(context->capability_ambient_set, false);
2612                                 if (r < 0) {
2613                                         *exit_status = EXIT_CAPABILITIES;
2614                                         return r;
2615                                 }
2616
2617                                 /* If we were asked to change user and ambient capabilities
2618                                  * were requested, we had to add keep-caps to the securebits
2619                                  * so that we would maintain the inherited capability set
2620                                  * through the setresuid(). Make sure that the bit is added
2621                                  * also to the context secure_bits so that we don't try to
2622                                  * drop the bit away next. */
2623
2624                                 secure_bits |= 1<<SECURE_KEEP_CAPS;
2625                         }
2626                 }
2627
2628                 /* PR_GET_SECUREBITS is not privileged, while
2629                  * PR_SET_SECUREBITS is. So to suppress
2630                  * potential EPERMs we'll try not to call
2631                  * PR_SET_SECUREBITS unless necessary. */
2632                 if (prctl(PR_GET_SECUREBITS) != secure_bits)
2633                         if (prctl(PR_SET_SECUREBITS, secure_bits) < 0) {
2634                                 *exit_status = EXIT_SECUREBITS;
2635                                 return -errno;
2636                         }
2637
2638                 if (context_has_no_new_privileges(context))
2639                         if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
2640                                 *exit_status = EXIT_NO_NEW_PRIVILEGES;
2641                                 return -errno;
2642                         }
2643
2644 #ifdef HAVE_SECCOMP
2645                 if (context_has_address_families(context)) {
2646                         r = apply_address_families(unit, context);
2647                         if (r < 0) {
2648                                 *exit_status = EXIT_ADDRESS_FAMILIES;
2649                                 return r;
2650                         }
2651                 }
2652
2653                 if (context->memory_deny_write_execute) {
2654                         r = apply_memory_deny_write_execute(unit, context);
2655                         if (r < 0) {
2656                                 *exit_status = EXIT_SECCOMP;
2657                                 return r;
2658                         }
2659                 }
2660
2661                 if (context->restrict_realtime) {
2662                         r = apply_restrict_realtime(unit, context);
2663                         if (r < 0) {
2664                                 *exit_status = EXIT_SECCOMP;
2665                                 return r;
2666                         }
2667                 }
2668
2669                 if (context->protect_kernel_tunables) {
2670                         r = apply_protect_sysctl(unit, context);
2671                         if (r < 0) {
2672                                 *exit_status = EXIT_SECCOMP;
2673                                 return r;
2674                         }
2675                 }
2676
2677                 if (context->private_devices) {
2678                         r = apply_private_devices(unit, context);
2679                         if (r < 0) {
2680                                 *exit_status = EXIT_SECCOMP;
2681                                 return r;
2682                         }
2683                 }
2684
2685                 if (context_has_syscall_filters(context)) {
2686                         r = apply_seccomp(unit, context);
2687                         if (r < 0) {
2688                                 *exit_status = EXIT_SECCOMP;
2689                                 return r;
2690                         }
2691                 }
2692 #endif
2693
2694 #ifdef HAVE_SELINUX
2695                 if (mac_selinux_use()) {
2696                         char *exec_context = mac_selinux_context_net ?: context->selinux_context;
2697
2698                         if (exec_context) {
2699                                 r = setexeccon(exec_context);
2700                                 if (r < 0) {
2701                                         *exit_status = EXIT_SELINUX_CONTEXT;
2702                                         return r;
2703                                 }
2704                         }
2705                 }
2706 #endif
2707
2708 #ifdef HAVE_APPARMOR
2709                 if (context->apparmor_profile && mac_apparmor_use()) {
2710                         r = aa_change_onexec(context->apparmor_profile);
2711                         if (r < 0 && !context->apparmor_profile_ignore) {
2712                                 *exit_status = EXIT_APPARMOR_PROFILE;
2713                                 return -errno;
2714                         }
2715                 }
2716 #endif
2717         }
2718
2719         final_argv = replace_env_argv(argv, accum_env);
2720         if (!final_argv) {
2721                 *exit_status = EXIT_MEMORY;
2722                 return -ENOMEM;
2723         }
2724
2725         if (_unlikely_(log_get_max_level() >= LOG_DEBUG)) {
2726                 _cleanup_free_ char *line;
2727
2728                 line = exec_command_line(final_argv);
2729                 if (line) {
2730                         log_open();
2731                         log_struct(LOG_DEBUG,
2732                                    LOG_UNIT_ID(unit),
2733                                    "EXECUTABLE=%s", command->path,
2734                                    LOG_UNIT_MESSAGE(unit, "Executing: %s", line),
2735                                    NULL);
2736                         log_close();
2737                 }
2738         }
2739
2740         execve(command->path, final_argv, accum_env);
2741         *exit_status = EXIT_EXEC;
2742         return -errno;
2743 }
2744
2745 int exec_spawn(Unit *unit,
2746                ExecCommand *command,
2747                const ExecContext *context,
2748                const ExecParameters *params,
2749                ExecRuntime *runtime,
2750                DynamicCreds *dcreds,
2751                pid_t *ret) {
2752
2753         _cleanup_strv_free_ char **files_env = NULL;
2754         int *fds = NULL; unsigned n_fds = 0;
2755         _cleanup_free_ char *line = NULL;
2756         int socket_fd, r;
2757         char **argv;
2758         pid_t pid;
2759
2760         assert(unit);
2761         assert(command);
2762         assert(context);
2763         assert(ret);
2764         assert(params);
2765         assert(params->fds || params->n_fds <= 0);
2766
2767         if (context->std_input == EXEC_INPUT_SOCKET ||
2768             context->std_output == EXEC_OUTPUT_SOCKET ||
2769             context->std_error == EXEC_OUTPUT_SOCKET) {
2770
2771                 if (params->n_fds != 1) {
2772                         log_unit_error(unit, "Got more than one socket.");
2773                         return -EINVAL;
2774                 }
2775
2776                 socket_fd = params->fds[0];
2777         } else {
2778                 socket_fd = -1;
2779                 fds = params->fds;
2780                 n_fds = params->n_fds;
2781         }
2782
2783         r = exec_context_load_environment(unit, context, &files_env);
2784         if (r < 0)
2785                 return log_unit_error_errno(unit, r, "Failed to load environment files: %m");
2786
2787         argv = params->argv ?: command->argv;
2788         line = exec_command_line(argv);
2789         if (!line)
2790                 return log_oom();
2791
2792         log_struct(LOG_DEBUG,
2793                    LOG_UNIT_ID(unit),
2794                    LOG_UNIT_MESSAGE(unit, "About to execute: %s", line),
2795                    "EXECUTABLE=%s", command->path,
2796                    NULL);
2797         pid = fork();
2798         if (pid < 0)
2799                 return log_unit_error_errno(unit, errno, "Failed to fork: %m");
2800
2801         if (pid == 0) {
2802                 int exit_status;
2803
2804                 r = exec_child(unit,
2805                                command,
2806                                context,
2807                                params,
2808                                runtime,
2809                                dcreds,
2810                                argv,
2811                                socket_fd,
2812                                fds, n_fds,
2813                                files_env,
2814                                unit->manager->user_lookup_fds[1],
2815                                &exit_status);
2816                 if (r < 0) {
2817                         log_open();
2818                         log_struct_errno(LOG_ERR, r,
2819                                          LOG_MESSAGE_ID(SD_MESSAGE_SPAWN_FAILED),
2820                                          LOG_UNIT_ID(unit),
2821                                          LOG_UNIT_MESSAGE(unit, "Failed at step %s spawning %s: %m",
2822                                                           exit_status_to_string(exit_status, EXIT_STATUS_SYSTEMD),
2823                                                           command->path),
2824                                          "EXECUTABLE=%s", command->path,
2825                                          NULL);
2826                 }
2827
2828                 _exit(exit_status);
2829         }
2830
2831         log_unit_debug(unit, "Forked %s as "PID_FMT, command->path, pid);
2832
2833         /* We add the new process to the cgroup both in the child (so
2834          * that we can be sure that no user code is ever executed
2835          * outside of the cgroup) and in the parent (so that we can be
2836          * sure that when we kill the cgroup the process will be
2837          * killed too). */
2838         if (params->cgroup_path)
2839                 (void) cg_attach(SYSTEMD_CGROUP_CONTROLLER, params->cgroup_path, pid);
2840
2841         exec_status_start(&command->exec_status, pid);
2842
2843         *ret = pid;
2844         return 0;
2845 }
2846
2847 void exec_context_init(ExecContext *c) {
2848         assert(c);
2849
2850         c->umask = 0022;
2851         c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);
2852         c->cpu_sched_policy = SCHED_OTHER;
2853         c->syslog_priority = LOG_DAEMON|LOG_INFO;
2854         c->syslog_level_prefix = true;
2855         c->ignore_sigpipe = true;
2856         c->timer_slack_nsec = NSEC_INFINITY;
2857         c->personality = PERSONALITY_INVALID;
2858         c->runtime_directory_mode = 0755;
2859         c->capability_bounding_set = CAP_ALL;
2860 }
2861
2862 void exec_context_done(ExecContext *c) {
2863         unsigned l;
2864
2865         assert(c);
2866
2867         c->environment = strv_free(c->environment);
2868         c->environment_files = strv_free(c->environment_files);
2869         c->pass_environment = strv_free(c->pass_environment);
2870
2871         for (l = 0; l < ELEMENTSOF(c->rlimit); l++)
2872                 c->rlimit[l] = mfree(c->rlimit[l]);
2873
2874         c->working_directory = mfree(c->working_directory);
2875         c->root_directory = mfree(c->root_directory);
2876         c->tty_path = mfree(c->tty_path);
2877         c->syslog_identifier = mfree(c->syslog_identifier);
2878         c->user = mfree(c->user);
2879         c->group = mfree(c->group);
2880
2881         c->supplementary_groups = strv_free(c->supplementary_groups);
2882
2883         c->pam_name = mfree(c->pam_name);
2884
2885         c->read_only_paths = strv_free(c->read_only_paths);
2886         c->read_write_paths = strv_free(c->read_write_paths);
2887         c->inaccessible_paths = strv_free(c->inaccessible_paths);
2888
2889         if (c->cpuset)
2890                 CPU_FREE(c->cpuset);
2891
2892         c->utmp_id = mfree(c->utmp_id);
2893         c->selinux_context = mfree(c->selinux_context);
2894         c->apparmor_profile = mfree(c->apparmor_profile);
2895
2896         c->syscall_filter = set_free(c->syscall_filter);
2897         c->syscall_archs = set_free(c->syscall_archs);
2898         c->address_families = set_free(c->address_families);
2899
2900         c->runtime_directory = strv_free(c->runtime_directory);
2901 }
2902
2903 int exec_context_destroy_runtime_directory(ExecContext *c, const char *runtime_prefix) {
2904         char **i;
2905
2906         assert(c);
2907
2908         if (!runtime_prefix)
2909                 return 0;
2910
2911         STRV_FOREACH(i, c->runtime_directory) {
2912                 _cleanup_free_ char *p;
2913
2914                 p = strjoin(runtime_prefix, "/", *i, NULL);
2915                 if (!p)
2916                         return -ENOMEM;
2917
2918                 /* We execute this synchronously, since we need to be
2919                  * sure this is gone when we start the service
2920                  * next. */
2921                 (void) rm_rf(p, REMOVE_ROOT);
2922         }
2923
2924         return 0;
2925 }
2926
2927 void exec_command_done(ExecCommand *c) {
2928         assert(c);
2929
2930         c->path = mfree(c->path);
2931
2932         c->argv = strv_free(c->argv);
2933 }
2934
2935 void exec_command_done_array(ExecCommand *c, unsigned n) {
2936         unsigned i;
2937
2938         for (i = 0; i < n; i++)
2939                 exec_command_done(c+i);
2940 }
2941
2942 ExecCommand* exec_command_free_list(ExecCommand *c) {
2943         ExecCommand *i;
2944
2945         while ((i = c)) {
2946                 LIST_REMOVE(command, c, i);
2947                 exec_command_done(i);
2948                 free(i);
2949         }
2950
2951         return NULL;
2952 }
2953
2954 void exec_command_free_array(ExecCommand **c, unsigned n) {
2955         unsigned i;
2956
2957         for (i = 0; i < n; i++)
2958                 c[i] = exec_command_free_list(c[i]);
2959 }
2960
2961 typedef struct InvalidEnvInfo {
2962         Unit *unit;
2963         const char *path;
2964 } InvalidEnvInfo;
2965
2966 static void invalid_env(const char *p, void *userdata) {
2967         InvalidEnvInfo *info = userdata;
2968
2969         log_unit_error(info->unit, "Ignoring invalid environment assignment '%s': %s", p, info->path);
2970 }
2971
2972 int exec_context_load_environment(Unit *unit, const ExecContext *c, char ***l) {
2973         char **i, **r = NULL;
2974
2975         assert(c);
2976         assert(l);
2977
2978         STRV_FOREACH(i, c->environment_files) {
2979                 char *fn;
2980                 int k;
2981                 bool ignore = false;
2982                 char **p;
2983                 _cleanup_globfree_ glob_t pglob = {};
2984                 int count, n;
2985
2986                 fn = *i;
2987
2988                 if (fn[0] == '-') {
2989                         ignore = true;
2990                         fn++;
2991                 }
2992
2993                 if (!path_is_absolute(fn)) {
2994                         if (ignore)
2995                                 continue;
2996
2997                         strv_free(r);
2998                         return -EINVAL;
2999                 }
3000
3001                 /* Filename supports globbing, take all matching files */
3002                 errno = 0;
3003                 if (glob(fn, 0, NULL, &pglob) != 0) {
3004                         if (ignore)
3005                                 continue;
3006
3007                         strv_free(r);
3008                         return errno > 0 ? -errno : -EINVAL;
3009                 }
3010                 count = pglob.gl_pathc;
3011                 if (count == 0) {
3012                         if (ignore)
3013                                 continue;
3014
3015                         strv_free(r);
3016                         return -EINVAL;
3017                 }
3018                 for (n = 0; n < count; n++) {
3019                         k = load_env_file(NULL, pglob.gl_pathv[n], NULL, &p);
3020                         if (k < 0) {
3021                                 if (ignore)
3022                                         continue;
3023
3024                                 strv_free(r);
3025                                 return k;
3026                         }
3027                         /* Log invalid environment variables with filename */
3028                         if (p) {
3029                                 InvalidEnvInfo info = {
3030                                         .unit = unit,
3031                                         .path = pglob.gl_pathv[n]
3032                                 };
3033
3034                                 p = strv_env_clean_with_callback(p, invalid_env, &info);
3035                         }
3036
3037                         if (r == NULL)
3038                                 r = p;
3039                         else {
3040                                 char **m;
3041
3042                                 m = strv_env_merge(2, r, p);
3043                                 strv_free(r);
3044                                 strv_free(p);
3045                                 if (!m)
3046                                         return -ENOMEM;
3047
3048                                 r = m;
3049                         }
3050                 }
3051         }
3052
3053         *l = r;
3054
3055         return 0;
3056 }
3057
3058 static bool tty_may_match_dev_console(const char *tty) {
3059         _cleanup_free_ char *active = NULL;
3060         char *console;
3061
3062         if (!tty)
3063                 return true;
3064
3065         if (startswith(tty, "/dev/"))
3066                 tty += 5;
3067
3068         /* trivial identity? */
3069         if (streq(tty, "console"))
3070                 return true;
3071
3072         console = resolve_dev_console(&active);
3073         /* if we could not resolve, assume it may */
3074         if (!console)
3075                 return true;
3076
3077         /* "tty0" means the active VC, so it may be the same sometimes */
3078         return streq(console, tty) || (streq(console, "tty0") && tty_is_vc(tty));
3079 }
3080
3081 bool exec_context_may_touch_console(ExecContext *ec) {
3082
3083         return (ec->tty_reset ||
3084                 ec->tty_vhangup ||
3085                 ec->tty_vt_disallocate ||
3086                 is_terminal_input(ec->std_input) ||
3087                 is_terminal_output(ec->std_output) ||
3088                 is_terminal_output(ec->std_error)) &&
3089                tty_may_match_dev_console(exec_context_tty_path(ec));
3090 }
3091
3092 static void strv_fprintf(FILE *f, char **l) {
3093         char **g;
3094
3095         assert(f);
3096
3097         STRV_FOREACH(g, l)
3098                 fprintf(f, " %s", *g);
3099 }
3100
3101 void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
3102         char **e, **d;
3103         unsigned i;
3104
3105         assert(c);
3106         assert(f);
3107
3108         prefix = strempty(prefix);
3109
3110         fprintf(f,
3111                 "%sUMask: %04o\n"
3112                 "%sWorkingDirectory: %s\n"
3113                 "%sRootDirectory: %s\n"
3114                 "%sNonBlocking: %s\n"
3115                 "%sPrivateTmp: %s\n"
3116                 "%sPrivateDevices: %s\n"
3117                 "%sProtectKernelTunables: %s\n"
3118                 "%sProtectControlGroups: %s\n"
3119                 "%sPrivateNetwork: %s\n"
3120                 "%sPrivateUsers: %s\n"
3121                 "%sProtectHome: %s\n"
3122                 "%sProtectSystem: %s\n"
3123                 "%sIgnoreSIGPIPE: %s\n"
3124                 "%sMemoryDenyWriteExecute: %s\n"
3125                 "%sRestrictRealtime: %s\n",
3126                 prefix, c->umask,
3127                 prefix, c->working_directory ? c->working_directory : "/",
3128                 prefix, c->root_directory ? c->root_directory : "/",
3129                 prefix, yes_no(c->non_blocking),
3130                 prefix, yes_no(c->private_tmp),
3131                 prefix, yes_no(c->private_devices),
3132                 prefix, yes_no(c->protect_kernel_tunables),
3133                 prefix, yes_no(c->protect_control_groups),
3134                 prefix, yes_no(c->private_network),
3135                 prefix, yes_no(c->private_users),
3136                 prefix, protect_home_to_string(c->protect_home),
3137                 prefix, protect_system_to_string(c->protect_system),
3138                 prefix, yes_no(c->ignore_sigpipe),
3139                 prefix, yes_no(c->memory_deny_write_execute),
3140                 prefix, yes_no(c->restrict_realtime));
3141
3142         STRV_FOREACH(e, c->environment)
3143                 fprintf(f, "%sEnvironment: %s\n", prefix, *e);
3144
3145         STRV_FOREACH(e, c->environment_files)
3146                 fprintf(f, "%sEnvironmentFile: %s\n", prefix, *e);
3147
3148         STRV_FOREACH(e, c->pass_environment)
3149                 fprintf(f, "%sPassEnvironment: %s\n", prefix, *e);
3150
3151         fprintf(f, "%sRuntimeDirectoryMode: %04o\n", prefix, c->runtime_directory_mode);
3152
3153         STRV_FOREACH(d, c->runtime_directory)
3154                 fprintf(f, "%sRuntimeDirectory: %s\n", prefix, *d);
3155
3156         if (c->nice_set)
3157                 fprintf(f,
3158                         "%sNice: %i\n",
3159                         prefix, c->nice);
3160
3161         if (c->oom_score_adjust_set)
3162                 fprintf(f,
3163                         "%sOOMScoreAdjust: %i\n",
3164                         prefix, c->oom_score_adjust);
3165
3166         for (i = 0; i < RLIM_NLIMITS; i++)
3167                 if (c->rlimit[i]) {
3168                         fprintf(f, "%s%s: " RLIM_FMT "\n",
3169                                 prefix, rlimit_to_string(i), c->rlimit[i]->rlim_max);
3170                         fprintf(f, "%s%sSoft: " RLIM_FMT "\n",
3171                                 prefix, rlimit_to_string(i), c->rlimit[i]->rlim_cur);
3172                 }
3173
3174         if (c->ioprio_set) {
3175                 _cleanup_free_ char *class_str = NULL;
3176
3177                 ioprio_class_to_string_alloc(IOPRIO_PRIO_CLASS(c->ioprio), &class_str);
3178                 fprintf(f,
3179                         "%sIOSchedulingClass: %s\n"
3180                         "%sIOPriority: %i\n",
3181                         prefix, strna(class_str),
3182                         prefix, (int) IOPRIO_PRIO_DATA(c->ioprio));
3183         }
3184
3185         if (c->cpu_sched_set) {
3186                 _cleanup_free_ char *policy_str = NULL;
3187
3188                 sched_policy_to_string_alloc(c->cpu_sched_policy, &policy_str);
3189                 fprintf(f,
3190                         "%sCPUSchedulingPolicy: %s\n"
3191                         "%sCPUSchedulingPriority: %i\n"
3192                         "%sCPUSchedulingResetOnFork: %s\n",
3193                         prefix, strna(policy_str),
3194                         prefix, c->cpu_sched_priority,
3195                         prefix, yes_no(c->cpu_sched_reset_on_fork));
3196         }
3197
3198         if (c->cpuset) {
3199                 fprintf(f, "%sCPUAffinity:", prefix);
3200                 for (i = 0; i < c->cpuset_ncpus; i++)
3201                         if (CPU_ISSET_S(i, CPU_ALLOC_SIZE(c->cpuset_ncpus), c->cpuset))
3202                                 fprintf(f, " %u", i);
3203                 fputs("\n", f);
3204         }
3205
3206         if (c->timer_slack_nsec != NSEC_INFINITY)
3207                 fprintf(f, "%sTimerSlackNSec: "NSEC_FMT "\n", prefix, c->timer_slack_nsec);
3208
3209         fprintf(f,
3210                 "%sStandardInput: %s\n"
3211                 "%sStandardOutput: %s\n"
3212                 "%sStandardError: %s\n",
3213                 prefix, exec_input_to_string(c->std_input),
3214                 prefix, exec_output_to_string(c->std_output),
3215                 prefix, exec_output_to_string(c->std_error));
3216
3217         if (c->tty_path)
3218                 fprintf(f,
3219                         "%sTTYPath: %s\n"
3220                         "%sTTYReset: %s\n"
3221                         "%sTTYVHangup: %s\n"
3222                         "%sTTYVTDisallocate: %s\n",
3223                         prefix, c->tty_path,
3224                         prefix, yes_no(c->tty_reset),
3225                         prefix, yes_no(c->tty_vhangup),
3226                         prefix, yes_no(c->tty_vt_disallocate));
3227
3228         if (c->std_output == EXEC_OUTPUT_SYSLOG ||
3229             c->std_output == EXEC_OUTPUT_KMSG ||
3230             c->std_output == EXEC_OUTPUT_JOURNAL ||
3231             c->std_output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE ||
3232             c->std_output == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
3233             c->std_output == EXEC_OUTPUT_JOURNAL_AND_CONSOLE ||
3234             c->std_error == EXEC_OUTPUT_SYSLOG ||
3235             c->std_error == EXEC_OUTPUT_KMSG ||
3236             c->std_error == EXEC_OUTPUT_JOURNAL ||
3237             c->std_error == EXEC_OUTPUT_SYSLOG_AND_CONSOLE ||
3238             c->std_error == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
3239             c->std_error == EXEC_OUTPUT_JOURNAL_AND_CONSOLE) {
3240
3241                 _cleanup_free_ char *fac_str = NULL, *lvl_str = NULL;
3242
3243                 log_facility_unshifted_to_string_alloc(c->syslog_priority >> 3, &fac_str);
3244                 log_level_to_string_alloc(LOG_PRI(c->syslog_priority), &lvl_str);
3245
3246                 fprintf(f,
3247                         "%sSyslogFacility: %s\n"
3248                         "%sSyslogLevel: %s\n",
3249                         prefix, strna(fac_str),
3250                         prefix, strna(lvl_str));
3251         }
3252
3253         if (c->secure_bits)
3254                 fprintf(f, "%sSecure Bits:%s%s%s%s%s%s\n",
3255                         prefix,
3256                         (c->secure_bits & 1<<SECURE_KEEP_CAPS) ? " keep-caps" : "",
3257                         (c->secure_bits & 1<<SECURE_KEEP_CAPS_LOCKED) ? " keep-caps-locked" : "",
3258                         (c->secure_bits & 1<<SECURE_NO_SETUID_FIXUP) ? " no-setuid-fixup" : "",
3259                         (c->secure_bits & 1<<SECURE_NO_SETUID_FIXUP_LOCKED) ? " no-setuid-fixup-locked" : "",
3260                         (c->secure_bits & 1<<SECURE_NOROOT) ? " noroot" : "",
3261                         (c->secure_bits & 1<<SECURE_NOROOT_LOCKED) ? "noroot-locked" : "");
3262
3263         if (c->capability_bounding_set != CAP_ALL) {
3264                 unsigned long l;
3265                 fprintf(f, "%sCapabilityBoundingSet:", prefix);
3266
3267                 for (l = 0; l <= cap_last_cap(); l++)
3268                         if (c->capability_bounding_set & (UINT64_C(1) << l))
3269                                 fprintf(f, " %s", strna(capability_to_name(l)));
3270
3271                 fputs("\n", f);
3272         }
3273
3274         if (c->capability_ambient_set != 0) {
3275                 unsigned long l;
3276                 fprintf(f, "%sAmbientCapabilities:", prefix);
3277
3278                 for (l = 0; l <= cap_last_cap(); l++)
3279                         if (c->capability_ambient_set & (UINT64_C(1) << l))
3280                                 fprintf(f, " %s", strna(capability_to_name(l)));
3281
3282                 fputs("\n", f);
3283         }
3284
3285         if (c->user)
3286                 fprintf(f, "%sUser: %s\n", prefix, c->user);
3287         if (c->group)
3288                 fprintf(f, "%sGroup: %s\n", prefix, c->group);
3289
3290         fprintf(f, "%sDynamicUser: %s\n", prefix, yes_no(c->dynamic_user));
3291
3292         if (strv_length(c->supplementary_groups) > 0) {
3293                 fprintf(f, "%sSupplementaryGroups:", prefix);
3294                 strv_fprintf(f, c->supplementary_groups);
3295                 fputs("\n", f);
3296         }
3297
3298         if (c->pam_name)
3299                 fprintf(f, "%sPAMName: %s\n", prefix, c->pam_name);
3300
3301         if (strv_length(c->read_write_paths) > 0) {
3302                 fprintf(f, "%sReadWritePaths:", prefix);
3303                 strv_fprintf(f, c->read_write_paths);
3304                 fputs("\n", f);
3305         }
3306
3307         if (strv_length(c->read_only_paths) > 0) {
3308                 fprintf(f, "%sReadOnlyPaths:", prefix);
3309                 strv_fprintf(f, c->read_only_paths);
3310                 fputs("\n", f);
3311         }
3312
3313         if (strv_length(c->inaccessible_paths) > 0) {
3314                 fprintf(f, "%sInaccessiblePaths:", prefix);
3315                 strv_fprintf(f, c->inaccessible_paths);
3316                 fputs("\n", f);
3317         }
3318
3319         if (c->utmp_id)
3320                 fprintf(f,
3321                         "%sUtmpIdentifier: %s\n",
3322                         prefix, c->utmp_id);
3323
3324         if (c->selinux_context)
3325                 fprintf(f,
3326                         "%sSELinuxContext: %s%s\n",
3327                         prefix, c->selinux_context_ignore ? "-" : "", c->selinux_context);
3328
3329         if (c->personality != PERSONALITY_INVALID)
3330                 fprintf(f,
3331                         "%sPersonality: %s\n",
3332                         prefix, strna(personality_to_string(c->personality)));
3333
3334         if (c->syscall_filter) {
3335 #ifdef HAVE_SECCOMP
3336                 Iterator j;
3337                 void *id;
3338                 bool first = true;
3339 #endif
3340
3341                 fprintf(f,
3342                         "%sSystemCallFilter: ",
3343                         prefix);
3344
3345                 if (!c->syscall_whitelist)
3346                         fputc('~', f);
3347
3348 #ifdef HAVE_SECCOMP
3349                 SET_FOREACH(id, c->syscall_filter, j) {
3350                         _cleanup_free_ char *name = NULL;
3351
3352                         if (first)
3353                                 first = false;
3354                         else
3355                                 fputc(' ', f);
3356
3357                         name = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE, PTR_TO_INT(id) - 1);
3358                         fputs(strna(name), f);
3359                 }
3360 #endif
3361
3362                 fputc('\n', f);
3363         }
3364
3365         if (c->syscall_archs) {
3366 #ifdef HAVE_SECCOMP
3367                 Iterator j;
3368                 void *id;
3369 #endif
3370
3371                 fprintf(f,
3372                         "%sSystemCallArchitectures:",
3373                         prefix);
3374
3375 #ifdef HAVE_SECCOMP
3376                 SET_FOREACH(id, c->syscall_archs, j)
3377                         fprintf(f, " %s", strna(seccomp_arch_to_string(PTR_TO_UINT32(id) - 1)));
3378 #endif
3379                 fputc('\n', f);
3380         }
3381
3382         if (c->syscall_errno > 0)
3383                 fprintf(f,
3384                         "%sSystemCallErrorNumber: %s\n",
3385                         prefix, strna(errno_to_name(c->syscall_errno)));
3386
3387         if (c->apparmor_profile)
3388                 fprintf(f,
3389                         "%sAppArmorProfile: %s%s\n",
3390                         prefix, c->apparmor_profile_ignore ? "-" : "", c->apparmor_profile);
3391 }
3392
3393 bool exec_context_maintains_privileges(ExecContext *c) {
3394         assert(c);
3395
3396         /* Returns true if the process forked off would run under
3397          * an unchanged UID or as root. */
3398
3399         if (!c->user)
3400                 return true;
3401
3402         if (streq(c->user, "root") || streq(c->user, "0"))
3403                 return true;
3404
3405         return false;
3406 }
3407
3408 void exec_status_start(ExecStatus *s, pid_t pid) {
3409         assert(s);
3410
3411         zero(*s);
3412         s->pid = pid;
3413         dual_timestamp_get(&s->start_timestamp);
3414 }
3415
3416 void exec_status_exit(ExecStatus *s, ExecContext *context, pid_t pid, int code, int status) {
3417         assert(s);
3418
3419         if (s->pid && s->pid != pid)
3420                 zero(*s);
3421
3422         s->pid = pid;
3423         dual_timestamp_get(&s->exit_timestamp);
3424
3425         s->code = code;
3426         s->status = status;
3427
3428         if (context) {
3429                 if (context->utmp_id)
3430                         utmp_put_dead_process(context->utmp_id, pid, code, status);
3431
3432                 exec_context_tty_reset(context, NULL);
3433         }
3434 }
3435
3436 void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix) {
3437         char buf[FORMAT_TIMESTAMP_MAX];
3438
3439         assert(s);
3440         assert(f);
3441
3442         if (s->pid <= 0)
3443                 return;
3444
3445         prefix = strempty(prefix);
3446
3447         fprintf(f,
3448                 "%sPID: "PID_FMT"\n",
3449                 prefix, s->pid);
3450
3451         if (dual_timestamp_is_set(&s->start_timestamp))
3452                 fprintf(f,
3453                         "%sStart Timestamp: %s\n",
3454                         prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp.realtime));
3455
3456         if (dual_timestamp_is_set(&s->exit_timestamp))
3457                 fprintf(f,
3458                         "%sExit Timestamp: %s\n"
3459                         "%sExit Code: %s\n"
3460                         "%sExit Status: %i\n",
3461                         prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp.realtime),
3462                         prefix, sigchld_code_to_string(s->code),
3463                         prefix, s->status);
3464 }
3465
3466 char *exec_command_line(char **argv) {
3467         size_t k;
3468         char *n, *p, **a;
3469         bool first = true;
3470
3471         assert(argv);
3472
3473         k = 1;
3474         STRV_FOREACH(a, argv)
3475                 k += strlen(*a)+3;
3476
3477         if (!(n = new(char, k)))
3478                 return NULL;
3479
3480         p = n;
3481         STRV_FOREACH(a, argv) {
3482
3483                 if (!first)
3484                         *(p++) = ' ';
3485                 else
3486                         first = false;
3487
3488                 if (strpbrk(*a, WHITESPACE)) {
3489                         *(p++) = '\'';
3490                         p = stpcpy(p, *a);
3491                         *(p++) = '\'';
3492                 } else
3493                         p = stpcpy(p, *a);
3494
3495         }
3496
3497         *p = 0;
3498
3499         /* FIXME: this doesn't really handle arguments that have
3500          * spaces and ticks in them */
3501
3502         return n;
3503 }
3504
3505 void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
3506         _cleanup_free_ char *cmd = NULL;
3507         const char *prefix2;
3508
3509         assert(c);
3510         assert(f);
3511
3512         prefix = strempty(prefix);
3513         prefix2 = strjoina(prefix, "\t");
3514
3515         cmd = exec_command_line(c->argv);
3516         fprintf(f,
3517                 "%sCommand Line: %s\n",
3518                 prefix, cmd ? cmd : strerror(ENOMEM));
3519
3520         exec_status_dump(&c->exec_status, f, prefix2);
3521 }
3522
3523 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
3524         assert(f);
3525
3526         prefix = strempty(prefix);
3527
3528         LIST_FOREACH(command, c, c)
3529                 exec_command_dump(c, f, prefix);
3530 }
3531
3532 void exec_command_append_list(ExecCommand **l, ExecCommand *e) {
3533         ExecCommand *end;
3534
3535         assert(l);
3536         assert(e);
3537
3538         if (*l) {
3539                 /* It's kind of important, that we keep the order here */
3540                 LIST_FIND_TAIL(command, *l, end);
3541                 LIST_INSERT_AFTER(command, *l, end, e);
3542         } else
3543               *l = e;
3544 }
3545
3546 int exec_command_set(ExecCommand *c, const char *path, ...) {
3547         va_list ap;
3548         char **l, *p;
3549
3550         assert(c);
3551         assert(path);
3552
3553         va_start(ap, path);
3554         l = strv_new_ap(path, ap);
3555         va_end(ap);
3556
3557         if (!l)
3558                 return -ENOMEM;
3559
3560         p = strdup(path);
3561         if (!p) {
3562                 strv_free(l);
3563                 return -ENOMEM;
3564         }
3565
3566         free(c->path);
3567         c->path = p;
3568
3569         strv_free(c->argv);
3570         c->argv = l;
3571
3572         return 0;
3573 }
3574
3575 int exec_command_append(ExecCommand *c, const char *path, ...) {
3576         _cleanup_strv_free_ char **l = NULL;
3577         va_list ap;
3578         int r;
3579
3580         assert(c);
3581         assert(path);
3582
3583         va_start(ap, path);
3584         l = strv_new_ap(path, ap);
3585         va_end(ap);
3586
3587         if (!l)
3588                 return -ENOMEM;
3589
3590         r = strv_extend_strv(&c->argv, l, false);
3591         if (r < 0)
3592                 return r;
3593
3594         return 0;
3595 }
3596
3597
3598 static int exec_runtime_allocate(ExecRuntime **rt) {
3599
3600         if (*rt)
3601                 return 0;
3602
3603         *rt = new0(ExecRuntime, 1);
3604         if (!*rt)
3605                 return -ENOMEM;
3606
3607         (*rt)->n_ref = 1;
3608         (*rt)->netns_storage_socket[0] = (*rt)->netns_storage_socket[1] = -1;
3609
3610         return 0;
3611 }
3612
3613 int exec_runtime_make(ExecRuntime **rt, ExecContext *c, const char *id) {
3614         int r;
3615
3616         assert(rt);
3617         assert(c);
3618         assert(id);
3619
3620         if (*rt)
3621                 return 1;
3622
3623         if (!c->private_network && !c->private_tmp)
3624                 return 0;
3625
3626         r = exec_runtime_allocate(rt);
3627         if (r < 0)
3628                 return r;
3629
3630         if (c->private_network && (*rt)->netns_storage_socket[0] < 0) {
3631                 if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, (*rt)->netns_storage_socket) < 0)
3632                         return -errno;
3633         }
3634
3635         if (c->private_tmp && !(*rt)->tmp_dir) {
3636                 r = setup_tmp_dirs(id, &(*rt)->tmp_dir, &(*rt)->var_tmp_dir);
3637                 if (r < 0)
3638                         return r;
3639         }
3640
3641         return 1;
3642 }
3643
3644 ExecRuntime *exec_runtime_ref(ExecRuntime *r) {
3645         assert(r);
3646         assert(r->n_ref > 0);
3647
3648         r->n_ref++;
3649         return r;
3650 }
3651
3652 ExecRuntime *exec_runtime_unref(ExecRuntime *r) {
3653
3654         if (!r)
3655                 return NULL;
3656
3657         assert(r->n_ref > 0);
3658
3659         r->n_ref--;
3660         if (r->n_ref > 0)
3661                 return NULL;
3662
3663         free(r->tmp_dir);
3664         free(r->var_tmp_dir);
3665         safe_close_pair(r->netns_storage_socket);
3666         free(r);
3667
3668         return NULL;
3669 }
3670
3671 int exec_runtime_serialize(Unit *u, ExecRuntime *rt, FILE *f, FDSet *fds) {
3672         assert(u);
3673         assert(f);
3674         assert(fds);
3675
3676         if (!rt)
3677                 return 0;
3678
3679         if (rt->tmp_dir)
3680                 unit_serialize_item(u, f, "tmp-dir", rt->tmp_dir);
3681
3682         if (rt->var_tmp_dir)
3683                 unit_serialize_item(u, f, "var-tmp-dir", rt->var_tmp_dir);
3684
3685         if (rt->netns_storage_socket[0] >= 0) {
3686                 int copy;
3687
3688                 copy = fdset_put_dup(fds, rt->netns_storage_socket[0]);
3689                 if (copy < 0)
3690                         return copy;
3691
3692                 unit_serialize_item_format(u, f, "netns-socket-0", "%i", copy);
3693         }
3694
3695         if (rt->netns_storage_socket[1] >= 0) {
3696                 int copy;
3697
3698                 copy = fdset_put_dup(fds, rt->netns_storage_socket[1]);
3699                 if (copy < 0)
3700                         return copy;
3701
3702                 unit_serialize_item_format(u, f, "netns-socket-1", "%i", copy);
3703         }
3704
3705         return 0;
3706 }
3707
3708 int exec_runtime_deserialize_item(Unit *u, ExecRuntime **rt, const char *key, const char *value, FDSet *fds) {
3709         int r;
3710
3711         assert(rt);
3712         assert(key);
3713         assert(value);
3714
3715         if (streq(key, "tmp-dir")) {
3716                 char *copy;
3717
3718                 r = exec_runtime_allocate(rt);
3719                 if (r < 0)
3720                         return log_oom();
3721
3722                 copy = strdup(value);
3723                 if (!copy)
3724                         return log_oom();
3725
3726                 free((*rt)->tmp_dir);
3727                 (*rt)->tmp_dir = copy;
3728
3729         } else if (streq(key, "var-tmp-dir")) {
3730                 char *copy;
3731
3732                 r = exec_runtime_allocate(rt);
3733                 if (r < 0)
3734                         return log_oom();
3735
3736                 copy = strdup(value);
3737                 if (!copy)
3738                         return log_oom();
3739
3740                 free((*rt)->var_tmp_dir);
3741                 (*rt)->var_tmp_dir = copy;
3742
3743         } else if (streq(key, "netns-socket-0")) {
3744                 int fd;
3745
3746                 r = exec_runtime_allocate(rt);
3747                 if (r < 0)
3748                         return log_oom();
3749
3750                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd))
3751                         log_unit_debug(u, "Failed to parse netns socket value: %s", value);
3752                 else {
3753                         safe_close((*rt)->netns_storage_socket[0]);
3754                         (*rt)->netns_storage_socket[0] = fdset_remove(fds, fd);
3755                 }
3756         } else if (streq(key, "netns-socket-1")) {
3757                 int fd;
3758
3759                 r = exec_runtime_allocate(rt);
3760                 if (r < 0)
3761                         return log_oom();
3762
3763                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd))
3764                         log_unit_debug(u, "Failed to parse netns socket value: %s", value);
3765                 else {
3766                         safe_close((*rt)->netns_storage_socket[1]);
3767                         (*rt)->netns_storage_socket[1] = fdset_remove(fds, fd);
3768                 }
3769         } else
3770                 return 0;
3771
3772         return 1;
3773 }
3774
3775 static void *remove_tmpdir_thread(void *p) {
3776         _cleanup_free_ char *path = p;
3777
3778         (void) rm_rf(path, REMOVE_ROOT|REMOVE_PHYSICAL);
3779         return NULL;
3780 }
3781
3782 void exec_runtime_destroy(ExecRuntime *rt) {
3783         int r;
3784
3785         if (!rt)
3786                 return;
3787
3788         /* If there are multiple users of this, let's leave the stuff around */
3789         if (rt->n_ref > 1)
3790                 return;
3791
3792         if (rt->tmp_dir) {
3793                 log_debug("Spawning thread to nuke %s", rt->tmp_dir);
3794
3795                 r = asynchronous_job(remove_tmpdir_thread, rt->tmp_dir);
3796                 if (r < 0) {
3797                         log_warning_errno(r, "Failed to nuke %s: %m", rt->tmp_dir);
3798                         free(rt->tmp_dir);
3799                 }
3800
3801                 rt->tmp_dir = NULL;
3802         }
3803
3804         if (rt->var_tmp_dir) {
3805                 log_debug("Spawning thread to nuke %s", rt->var_tmp_dir);
3806
3807                 r = asynchronous_job(remove_tmpdir_thread, rt->var_tmp_dir);
3808                 if (r < 0) {
3809                         log_warning_errno(r, "Failed to nuke %s: %m", rt->var_tmp_dir);
3810                         free(rt->var_tmp_dir);
3811                 }
3812
3813                 rt->var_tmp_dir = NULL;
3814         }
3815
3816         safe_close_pair(rt->netns_storage_socket);
3817 }
3818
3819 static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
3820         [EXEC_INPUT_NULL] = "null",
3821         [EXEC_INPUT_TTY] = "tty",
3822         [EXEC_INPUT_TTY_FORCE] = "tty-force",
3823         [EXEC_INPUT_TTY_FAIL] = "tty-fail",
3824         [EXEC_INPUT_SOCKET] = "socket"
3825 };
3826
3827 DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);
3828
3829 static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
3830         [EXEC_OUTPUT_INHERIT] = "inherit",
3831         [EXEC_OUTPUT_NULL] = "null",
3832         [EXEC_OUTPUT_TTY] = "tty",
3833         [EXEC_OUTPUT_SYSLOG] = "syslog",
3834         [EXEC_OUTPUT_SYSLOG_AND_CONSOLE] = "syslog+console",
3835         [EXEC_OUTPUT_KMSG] = "kmsg",
3836         [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
3837         [EXEC_OUTPUT_JOURNAL] = "journal",
3838         [EXEC_OUTPUT_JOURNAL_AND_CONSOLE] = "journal+console",
3839         [EXEC_OUTPUT_SOCKET] = "socket"
3840 };
3841
3842 DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);
3843
3844 static const char* const exec_utmp_mode_table[_EXEC_UTMP_MODE_MAX] = {
3845         [EXEC_UTMP_INIT] = "init",
3846         [EXEC_UTMP_LOGIN] = "login",
3847         [EXEC_UTMP_USER] = "user",
3848 };
3849
3850 DEFINE_STRING_TABLE_LOOKUP(exec_utmp_mode, ExecUtmpMode);