src/core/execute.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <assert.h>
  23 #include <dirent.h>
  24 #include <errno.h>
  25 #include <fcntl.h>
  26 #include <unistd.h>
  27 #include <string.h>
  28 #include <signal.h>
  29 #include <sys/socket.h>
  30 #include <sys/un.h>
  31 #include <sys/prctl.h>
  32 #include <linux/sched.h>
  33 #include <sys/types.h>
  34 #include <sys/stat.h>
  35 #include <grp.h>
  36 #include <pwd.h>
  37 #include <sys/mount.h>
  38 #include <linux/fs.h>
  39 #include <linux/oom.h>
  40 #include <sys/poll.h>
  41 #include <glob.h>
  42 #include <sys/personality.h>
  43 #include <libgen.h>
  44 #undef basename
  45
  46 #ifdef HAVE_PAM
  47 #include <security/pam_appl.h>
  48 #endif
  49
  50 #ifdef HAVE_SELINUX
  51 #include <selinux/selinux.h>
  52 #endif
  53
  54 #ifdef HAVE_SECCOMP
  55 #include <seccomp.h>
  56 #endif
  57
  58 #ifdef HAVE_APPARMOR
  59 #include <sys/apparmor.h>
  60 #endif
  61
  62 #include "execute.h"
  63 #include "strv.h"
  64 #include "macro.h"
  65 #include "capability.h"
  66 #include "util.h"
  67 #include "log.h"
  68 #include "sd-messages.h"
  69 #include "ioprio.h"
  70 #include "securebits.h"
  71 #include "namespace.h"
  72 #include "exit-status.h"
  73 #include "missing.h"
  74 #include "utmp-wtmp.h"
  75 #include "def.h"
  76 #include "path-util.h"
  77 #include "env-util.h"
  78 #include "fileio.h"
  79 #include "unit.h"
  80 #include "async.h"
  81 #include "selinux-util.h"
  82 #include "errno-list.h"
  83 #include "af-list.h"
  84 #include "mkdir.h"
  85 #include "apparmor-util.h"
  86 #include "bus-kernel.h"
  87 #include "label.h"
  88
  89 #ifdef HAVE_SECCOMP
  90 #include "seccomp-util.h"
  91 #endif
  92
  93 #define IDLE_TIMEOUT_USEC (5*USEC_PER_SEC)
  94 #define IDLE_TIMEOUT2_USEC (1*USEC_PER_SEC)
  95
  96 /* This assumes there is a 'tty' group */
  97 #define TTY_MODE 0620
  98
  99 #define SNDBUF_SIZE (8*1024*1024)
 100
 101 static int shift_fds(int fds[], unsigned n_fds) {
 102         int start, restart_from;
 103
 104         if (n_fds <= 0)
 105                 return 0;
 106
 107         /* Modifies the fds array! (sorts it) */
 108
 109         assert(fds);
 110
 111         start = 0;
 112         for (;;) {
 113                 int i;
 114
 115                 restart_from = -1;
 116
 117                 for (i = start; i < (int) n_fds; i++) {
 118                         int nfd;
 119
 120                         /* Already at right index? */
 121                         if (fds[i] == i+3)
 122                                 continue;
 123
 124                         if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)
 125                                 return -errno;
 126
 127                         safe_close(fds[i]);
 128                         fds[i] = nfd;
 129
 130                         /* Hmm, the fd we wanted isn't free? Then
 131                          * let's remember that and try again from here*/
 132                         if (nfd != i+3 && restart_from < 0)
 133                                 restart_from = i;
 134                 }
 135
 136                 if (restart_from < 0)
 137                         break;
 138
 139                 start = restart_from;
 140         }
 141
 142         return 0;
 143 }
 144
 145 static int flags_fds(const int fds[], unsigned n_fds, bool nonblock) {
 146         unsigned i;
 147         int r;
 148
 149         if (n_fds <= 0)
 150                 return 0;
 151
 152         assert(fds);
 153
 154         /* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags */
 155
 156         for (i = 0; i < n_fds; i++) {
 157
 158                 if ((r = fd_nonblock(fds[i], nonblock)) < 0)
 159                         return r;
 160
 161                 /* We unconditionally drop FD_CLOEXEC from the fds,
 162                  * since after all we want to pass these fds to our
 163                  * children */
 164
 165                 if ((r = fd_cloexec(fds[i], false)) < 0)
 166                         return r;
 167         }
 168
 169         return 0;
 170 }
 171
 172 _pure_ static const char *tty_path(const ExecContext *context) {
 173         assert(context);
 174
 175         if (context->tty_path)
 176                 return context->tty_path;
 177
 178         return "/dev/console";
 179 }
 180
 181 static void exec_context_tty_reset(const ExecContext *context) {
 182         assert(context);
 183
 184         if (context->tty_vhangup)
 185                 terminal_vhangup(tty_path(context));
 186
 187         if (context->tty_reset)
 188                 reset_terminal(tty_path(context));
 189
 190         if (context->tty_vt_disallocate && context->tty_path)
 191                 vt_disallocate(context->tty_path);
 192 }
 193
 194 static bool is_terminal_output(ExecOutput o) {
 195         return
 196                 o == EXEC_OUTPUT_TTY ||
 197                 o == EXEC_OUTPUT_SYSLOG_AND_CONSOLE ||
 198                 o == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
 199                 o == EXEC_OUTPUT_JOURNAL_AND_CONSOLE;
 200 }
 201
 202 static int open_null_as(int flags, int nfd) {
 203         int fd, r;
 204
 205         assert(nfd >= 0);
 206
 207         fd = open("/dev/null", flags|O_NOCTTY);
 208         if (fd < 0)
 209                 return -errno;
 210
 211         if (fd != nfd) {
 212                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 213                 safe_close(fd);
 214         } else
 215                 r = nfd;
 216
 217         return r;
 218 }
 219
 220 static int connect_logger_as(const ExecContext *context, ExecOutput output, const char *ident, const char *unit_id, int nfd) {
 221         int fd, r;
 222         union sockaddr_union sa = {
 223                 .un.sun_family = AF_UNIX,
 224                 .un.sun_path = "/run/systemd/journal/stdout",
 225         };
 226
 227         assert(context);
 228         assert(output < _EXEC_OUTPUT_MAX);
 229         assert(ident);
 230         assert(nfd >= 0);
 231
 232         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 233         if (fd < 0)
 234                 return -errno;
 235
 236         r = connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path));
 237         if (r < 0) {
 238                 safe_close(fd);
 239                 return -errno;
 240         }
 241
 242         if (shutdown(fd, SHUT_RD) < 0) {
 243                 safe_close(fd);
 244                 return -errno;
 245         }
 246
 247         fd_inc_sndbuf(fd, SNDBUF_SIZE);
 248
 249         dprintf(fd,
 250                 "%s\n"
 251                 "%s\n"
 252                 "%i\n"
 253                 "%i\n"
 254                 "%i\n"
 255                 "%i\n"
 256                 "%i\n",
 257                 context->syslog_identifier ? context->syslog_identifier : ident,
 258                 unit_id,
 259                 context->syslog_priority,
 260                 !!context->syslog_level_prefix,
 261                 output == EXEC_OUTPUT_SYSLOG || output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
 262                 output == EXEC_OUTPUT_KMSG || output == EXEC_OUTPUT_KMSG_AND_CONSOLE,
 263                 is_terminal_output(output));
 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 static int open_terminal_as(const char *path, mode_t mode, int nfd) {
 274         int fd, r;
 275
 276         assert(path);
 277         assert(nfd >= 0);
 278
 279         if ((fd = open_terminal(path, mode | O_NOCTTY)) < 0)
 280                 return fd;
 281
 282         if (fd != nfd) {
 283                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 284                 safe_close(fd);
 285         } else
 286                 r = nfd;
 287
 288         return r;
 289 }
 290
 291 static bool is_terminal_input(ExecInput i) {
 292         return
 293                 i == EXEC_INPUT_TTY ||
 294                 i == EXEC_INPUT_TTY_FORCE ||
 295                 i == EXEC_INPUT_TTY_FAIL;
 296 }
 297
 298 static int fixup_input(ExecInput std_input, int socket_fd, bool apply_tty_stdin) {
 299
 300         if (is_terminal_input(std_input) && !apply_tty_stdin)
 301                 return EXEC_INPUT_NULL;
 302
 303         if (std_input == EXEC_INPUT_SOCKET && socket_fd < 0)
 304                 return EXEC_INPUT_NULL;
 305
 306         return std_input;
 307 }
 308
 309 static int fixup_output(ExecOutput std_output, int socket_fd) {
 310
 311         if (std_output == EXEC_OUTPUT_SOCKET && socket_fd < 0)
 312                 return EXEC_OUTPUT_INHERIT;
 313
 314         return std_output;
 315 }
 316
 317 static int setup_input(const ExecContext *context, int socket_fd, bool apply_tty_stdin) {
 318         ExecInput i;
 319
 320         assert(context);
 321
 322         i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);
 323
 324         switch (i) {
 325
 326         case EXEC_INPUT_NULL:
 327                 return open_null_as(O_RDONLY, STDIN_FILENO);
 328
 329         case EXEC_INPUT_TTY:
 330         case EXEC_INPUT_TTY_FORCE:
 331         case EXEC_INPUT_TTY_FAIL: {
 332                 int fd, r;
 333
 334                 fd = acquire_terminal(tty_path(context),
 335                                       i == EXEC_INPUT_TTY_FAIL,
 336                                       i == EXEC_INPUT_TTY_FORCE,
 337                                       false,
 338                                       USEC_INFINITY);
 339                 if (fd < 0)
 340                         return fd;
 341
 342                 if (fd != STDIN_FILENO) {
 343                         r = dup2(fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 344                         safe_close(fd);
 345                 } else
 346                         r = STDIN_FILENO;
 347
 348                 return r;
 349         }
 350
 351         case EXEC_INPUT_SOCKET:
 352                 return dup2(socket_fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 353
 354         default:
 355                 assert_not_reached("Unknown input type");
 356         }
 357 }
 358
 359 static int setup_output(const ExecContext *context, int fileno, int socket_fd, const char *ident, const char *unit_id, bool apply_tty_stdin) {
 360         ExecOutput o;
 361         ExecInput i;
 362         int r;
 363
 364         assert(context);
 365         assert(ident);
 366
 367         i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);
 368         o = fixup_output(context->std_output, socket_fd);
 369
 370         if (fileno == STDERR_FILENO) {
 371                 ExecOutput e;
 372                 e = fixup_output(context->std_error, socket_fd);
 373
 374                 /* This expects the input and output are already set up */
 375
 376                 /* Don't change the stderr file descriptor if we inherit all
 377                  * the way and are not on a tty */
 378                 if (e == EXEC_OUTPUT_INHERIT &&
 379                     o == EXEC_OUTPUT_INHERIT &&
 380                     i == EXEC_INPUT_NULL &&
 381                     !is_terminal_input(context->std_input) &&
 382                     getppid () != 1)
 383                         return fileno;
 384
 385                 /* Duplicate from stdout if possible */
 386                 if (e == o || e == EXEC_OUTPUT_INHERIT)
 387                         return dup2(STDOUT_FILENO, fileno) < 0 ? -errno : fileno;
 388
 389                 o = e;
 390
 391         } else if (o == EXEC_OUTPUT_INHERIT) {
 392                 /* If input got downgraded, inherit the original value */
 393                 if (i == EXEC_INPUT_NULL && is_terminal_input(context->std_input))
 394                         return open_terminal_as(tty_path(context), O_WRONLY, fileno);
 395
 396                 /* If the input is connected to anything that's not a /dev/null, inherit that... */
 397                 if (i != EXEC_INPUT_NULL)
 398                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 399
 400                 /* If we are not started from PID 1 we just inherit STDOUT from our parent process. */
 401                 if (getppid() != 1)
 402                         return fileno;
 403
 404                 /* We need to open /dev/null here anew, to get the right access mode. */
 405                 return open_null_as(O_WRONLY, fileno);
 406         }
 407
 408         switch (o) {
 409
 410         case EXEC_OUTPUT_NULL:
 411                 return open_null_as(O_WRONLY, fileno);
 412
 413         case EXEC_OUTPUT_TTY:
 414                 if (is_terminal_input(i))
 415                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 416
 417                 /* We don't reset the terminal if this is just about output */
 418                 return open_terminal_as(tty_path(context), O_WRONLY, fileno);
 419
 420         case EXEC_OUTPUT_SYSLOG:
 421         case EXEC_OUTPUT_SYSLOG_AND_CONSOLE:
 422         case EXEC_OUTPUT_KMSG:
 423         case EXEC_OUTPUT_KMSG_AND_CONSOLE:
 424         case EXEC_OUTPUT_JOURNAL:
 425         case EXEC_OUTPUT_JOURNAL_AND_CONSOLE:
 426                 r = connect_logger_as(context, o, ident, unit_id, fileno);
 427                 if (r < 0) {
 428                         log_struct_unit(LOG_CRIT, unit_id,
 429                                 "MESSAGE=Failed to connect std%s of %s to the journal socket: %s",
 430                                 fileno == STDOUT_FILENO ? "out" : "err",
 431                                 unit_id, strerror(-r),
 432                                 "ERRNO=%d", -r,
 433                                 NULL);
 434                         r = open_null_as(O_WRONLY, fileno);
 435                 }
 436                 return r;
 437
 438         case EXEC_OUTPUT_SOCKET:
 439                 assert(socket_fd >= 0);
 440                 return dup2(socket_fd, fileno) < 0 ? -errno : fileno;
 441
 442         default:
 443                 assert_not_reached("Unknown error type");
 444         }
 445 }
 446
 447 static int chown_terminal(int fd, uid_t uid) {
 448         struct stat st;
 449
 450         assert(fd >= 0);
 451
 452         /* This might fail. What matters are the results. */
 453         (void) fchown(fd, uid, -1);
 454         (void) fchmod(fd, TTY_MODE);
 455
 456         if (fstat(fd, &st) < 0)
 457                 return -errno;
 458
 459         if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE)
 460                 return -EPERM;
 461
 462         return 0;
 463 }
 464
 465 static int setup_confirm_stdio(int *_saved_stdin,
 466                                int *_saved_stdout) {
 467         int fd = -1, saved_stdin, saved_stdout = -1, r;
 468
 469         assert(_saved_stdin);
 470         assert(_saved_stdout);
 471
 472         saved_stdin = fcntl(STDIN_FILENO, F_DUPFD, 3);
 473         if (saved_stdin < 0)
 474                 return -errno;
 475
 476         saved_stdout = fcntl(STDOUT_FILENO, F_DUPFD, 3);
 477         if (saved_stdout < 0) {
 478                 r = errno;
 479                 goto fail;
 480         }
 481
 482         fd = acquire_terminal(
 483                         "/dev/console",
 484                         false,
 485                         false,
 486                         false,
 487                         DEFAULT_CONFIRM_USEC);
 488         if (fd < 0) {
 489                 r = fd;
 490                 goto fail;
 491         }
 492
 493         r = chown_terminal(fd, getuid());
 494         if (r < 0)
 495                 goto fail;
 496
 497         if (dup2(fd, STDIN_FILENO) < 0) {
 498                 r = -errno;
 499                 goto fail;
 500         }
 501
 502         if (dup2(fd, STDOUT_FILENO) < 0) {
 503                 r = -errno;
 504                 goto fail;
 505         }
 506
 507         if (fd >= 2)
 508                 safe_close(fd);
 509
 510         *_saved_stdin = saved_stdin;
 511         *_saved_stdout = saved_stdout;
 512
 513         return 0;
 514
 515 fail:
 516         safe_close(saved_stdout);
 517         safe_close(saved_stdin);
 518         safe_close(fd);
 519
 520         return r;
 521 }
 522
 523 _printf_(1, 2) static int write_confirm_message(const char *format, ...) {
 524         _cleanup_close_ int fd = -1;
 525         va_list ap;
 526
 527         assert(format);
 528
 529         fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
 530         if (fd < 0)
 531                 return fd;
 532
 533         va_start(ap, format);
 534         vdprintf(fd, format, ap);
 535         va_end(ap);
 536
 537         return 0;
 538 }
 539
 540 static int restore_confirm_stdio(int *saved_stdin,
 541                                  int *saved_stdout) {
 542
 543         int r = 0;
 544
 545         assert(saved_stdin);
 546         assert(saved_stdout);
 547
 548         release_terminal();
 549
 550         if (*saved_stdin >= 0)
 551                 if (dup2(*saved_stdin, STDIN_FILENO) < 0)
 552                         r = -errno;
 553
 554         if (*saved_stdout >= 0)
 555                 if (dup2(*saved_stdout, STDOUT_FILENO) < 0)
 556                         r = -errno;
 557
 558         safe_close(*saved_stdin);
 559         safe_close(*saved_stdout);
 560
 561         return r;
 562 }
 563
 564 static int ask_for_confirmation(char *response, char **argv) {
 565         int saved_stdout = -1, saved_stdin = -1, r;
 566         _cleanup_free_ char *line = NULL;
 567
 568         r = setup_confirm_stdio(&saved_stdin, &saved_stdout);
 569         if (r < 0)
 570                 return r;
 571
 572         line = exec_command_line(argv);
 573         if (!line)
 574                 return -ENOMEM;
 575
 576         r = ask_char(response, "yns", "Execute %s? [Yes, No, Skip] ", line);
 577
 578         restore_confirm_stdio(&saved_stdin, &saved_stdout);
 579
 580         return r;
 581 }
 582
 583 static int enforce_groups(const ExecContext *context, const char *username, gid_t gid) {
 584         bool keep_groups = false;
 585         int r;
 586
 587         assert(context);
 588
 589         /* Lookup and set GID and supplementary group list. Here too
 590          * we avoid NSS lookups for gid=0. */
 591
 592         if (context->group || username) {
 593
 594                 if (context->group) {
 595                         const char *g = context->group;
 596
 597                         if ((r = get_group_creds(&g, &gid)) < 0)
 598                                 return r;
 599                 }
 600
 601                 /* First step, initialize groups from /etc/groups */
 602                 if (username && gid != 0) {
 603                         if (initgroups(username, gid) < 0)
 604                                 return -errno;
 605
 606                         keep_groups = true;
 607                 }
 608
 609                 /* Second step, set our gids */
 610                 if (setresgid(gid, gid, gid) < 0)
 611                         return -errno;
 612         }
 613
 614         if (context->supplementary_groups) {
 615                 int ngroups_max, k;
 616                 gid_t *gids;
 617                 char **i;
 618
 619                 /* Final step, initialize any manually set supplementary groups */
 620                 assert_se((ngroups_max = (int) sysconf(_SC_NGROUPS_MAX)) > 0);
 621
 622                 if (!(gids = new(gid_t, ngroups_max)))
 623                         return -ENOMEM;
 624
 625                 if (keep_groups) {
 626                         if ((k = getgroups(ngroups_max, gids)) < 0) {
 627                                 free(gids);
 628                                 return -errno;
 629                         }
 630                 } else
 631                         k = 0;
 632
 633                 STRV_FOREACH(i, context->supplementary_groups) {
 634                         const char *g;
 635
 636                         if (k >= ngroups_max) {
 637                                 free(gids);
 638                                 return -E2BIG;
 639                         }
 640
 641                         g = *i;
 642                         r = get_group_creds(&g, gids+k);
 643                         if (r < 0) {
 644                                 free(gids);
 645                                 return r;
 646                         }
 647
 648                         k++;
 649                 }
 650
 651                 if (setgroups(k, gids) < 0) {
 652                         free(gids);
 653                         return -errno;
 654                 }
 655
 656                 free(gids);
 657         }
 658
 659         return 0;
 660 }
 661
 662 static int enforce_user(const ExecContext *context, uid_t uid) {
 663         assert(context);
 664
 665         /* Sets (but doesn't lookup) the uid and make sure we keep the
 666          * capabilities while doing so. */
 667
 668         if (context->capabilities) {
 669                 _cleanup_cap_free_ cap_t d = NULL;
 670                 static const cap_value_t bits[] = {
 671                         CAP_SETUID,   /* Necessary so that we can run setresuid() below */
 672                         CAP_SETPCAP   /* Necessary so that we can set PR_SET_SECUREBITS later on */
 673                 };
 674
 675                 /* First step: If we need to keep capabilities but
 676                  * drop privileges we need to make sure we keep our
 677                  * caps, while we drop privileges. */
 678                 if (uid != 0) {
 679                         int sb = context->secure_bits | 1<<SECURE_KEEP_CAPS;
 680
 681                         if (prctl(PR_GET_SECUREBITS) != sb)
 682                                 if (prctl(PR_SET_SECUREBITS, sb) < 0)
 683                                         return -errno;
 684                 }
 685
 686                 /* Second step: set the capabilities. This will reduce
 687                  * the capabilities to the minimum we need. */
 688
 689                 d = cap_dup(context->capabilities);
 690                 if (!d)
 691                         return -errno;
 692
 693                 if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 ||
 694                     cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0)
 695                         return -errno;
 696
 697                 if (cap_set_proc(d) < 0)
 698                         return -errno;
 699         }
 700
 701         /* Third step: actually set the uids */
 702         if (setresuid(uid, uid, uid) < 0)
 703                 return -errno;
 704
 705         /* At this point we should have all necessary capabilities but
 706            are otherwise a normal user. However, the caps might got
 707            corrupted due to the setresuid() so we need clean them up
 708            later. This is done outside of this call. */
 709
 710         return 0;
 711 }
 712
 713 #ifdef HAVE_PAM
 714
 715 static int null_conv(
 716                 int num_msg,
 717                 const struct pam_message **msg,
 718                 struct pam_response **resp,
 719                 void *appdata_ptr) {
 720
 721         /* We don't support conversations */
 722
 723         return PAM_CONV_ERR;
 724 }
 725
 726 static int setup_pam(
 727                 const char *name,
 728                 const char *user,
 729                 uid_t uid,
 730                 const char *tty,
 731                 char ***pam_env,
 732                 int fds[], unsigned n_fds) {
 733
 734         static const struct pam_conv conv = {
 735                 .conv = null_conv,
 736                 .appdata_ptr = NULL
 737         };
 738
 739         pam_handle_t *handle = NULL;
 740         sigset_t ss, old_ss;
 741         int pam_code = PAM_SUCCESS;
 742         int err;
 743         char **e = NULL;
 744         bool close_session = false;
 745         pid_t pam_pid = 0, parent_pid;
 746         int flags = 0;
 747
 748         assert(name);
 749         assert(user);
 750         assert(pam_env);
 751
 752         /* We set up PAM in the parent process, then fork. The child
 753          * will then stay around until killed via PR_GET_PDEATHSIG or
 754          * systemd via the cgroup logic. It will then remove the PAM
 755          * session again. The parent process will exec() the actual
 756          * daemon. We do things this way to ensure that the main PID
 757          * of the daemon is the one we initially fork()ed. */
 758
 759         if (log_get_max_level() < LOG_PRI(LOG_DEBUG))
 760                 flags |= PAM_SILENT;
 761
 762         pam_code = pam_start(name, user, &conv, &handle);
 763         if (pam_code != PAM_SUCCESS) {
 764                 handle = NULL;
 765                 goto fail;
 766         }
 767
 768         if (tty) {
 769                 pam_code = pam_set_item(handle, PAM_TTY, tty);
 770                 if (pam_code != PAM_SUCCESS)
 771                         goto fail;
 772         }
 773
 774         pam_code = pam_acct_mgmt(handle, flags);
 775         if (pam_code != PAM_SUCCESS)
 776                 goto fail;
 777
 778         pam_code = pam_open_session(handle, flags);
 779         if (pam_code != PAM_SUCCESS)
 780                 goto fail;
 781
 782         close_session = true;
 783
 784         e = pam_getenvlist(handle);
 785         if (!e) {
 786                 pam_code = PAM_BUF_ERR;
 787                 goto fail;
 788         }
 789
 790         /* Block SIGTERM, so that we know that it won't get lost in
 791          * the child */
 792         if (sigemptyset(&ss) < 0 ||
 793             sigaddset(&ss, SIGTERM) < 0 ||
 794             sigprocmask(SIG_BLOCK, &ss, &old_ss) < 0)
 795                 goto fail;
 796
 797         parent_pid = getpid();
 798
 799         pam_pid = fork();
 800         if (pam_pid < 0)
 801                 goto fail;
 802
 803         if (pam_pid == 0) {
 804                 int sig;
 805                 int r = EXIT_PAM;
 806
 807                 /* The child's job is to reset the PAM session on
 808                  * termination */
 809
 810                 /* This string must fit in 10 chars (i.e. the length
 811                  * of "/sbin/init"), to look pretty in /bin/ps */
 812                 rename_process("(sd-pam)");
 813
 814                 /* Make sure we don't keep open the passed fds in this
 815                 child. We assume that otherwise only those fds are
 816                 open here that have been opened by PAM. */
 817                 close_many(fds, n_fds);
 818
 819                 /* Drop privileges - we don't need any to pam_close_session
 820                  * and this will make PR_SET_PDEATHSIG work in most cases.
 821                  * If this fails, ignore the error - but expect sd-pam threads
 822                  * to fail to exit normally */
 823                 if (setresuid(uid, uid, uid) < 0)
 824                         log_error("Error: Failed to setresuid() in sd-pam: %s", strerror(-r));
 825
 826                 /* Wait until our parent died. This will only work if
 827                  * the above setresuid() succeeds, otherwise the kernel
 828                  * will not allow unprivileged parents kill their privileged
 829                  * children this way. We rely on the control groups kill logic
 830                  * to do the rest for us. */
 831                 if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
 832                         goto child_finish;
 833
 834                 /* Check if our parent process might already have
 835                  * died? */
 836                 if (getppid() == parent_pid) {
 837                         for (;;) {
 838                                 if (sigwait(&ss, &sig) < 0) {
 839                                         if (errno == EINTR)
 840                                                 continue;
 841
 842                                         goto child_finish;
 843                                 }
 844
 845                                 assert(sig == SIGTERM);
 846                                 break;
 847                         }
 848                 }
 849
 850                 /* If our parent died we'll end the session */
 851                 if (getppid() != parent_pid) {
 852                         pam_code = pam_close_session(handle, flags);
 853                         if (pam_code != PAM_SUCCESS)
 854                                 goto child_finish;
 855                 }
 856
 857                 r = 0;
 858
 859         child_finish:
 860                 pam_end(handle, pam_code | flags);
 861                 _exit(r);
 862         }
 863
 864         /* If the child was forked off successfully it will do all the
 865          * cleanups, so forget about the handle here. */
 866         handle = NULL;
 867
 868         /* Unblock SIGTERM again in the parent */
 869         if (sigprocmask(SIG_SETMASK, &old_ss, NULL) < 0)
 870                 goto fail;
 871
 872         /* We close the log explicitly here, since the PAM modules
 873          * might have opened it, but we don't want this fd around. */
 874         closelog();
 875
 876         *pam_env = e;
 877         e = NULL;
 878
 879         return 0;
 880
 881 fail:
 882         if (pam_code != PAM_SUCCESS) {
 883                 log_error("PAM failed: %s", pam_strerror(handle, pam_code));
 884                 err = -EPERM;  /* PAM errors do not map to errno */
 885         } else {
 886                 log_error("PAM failed: %m");
 887                 err = -errno;
 888         }
 889
 890         if (handle) {
 891                 if (close_session)
 892                         pam_code = pam_close_session(handle, flags);
 893
 894                 pam_end(handle, pam_code | flags);
 895         }
 896
 897         strv_free(e);
 898
 899         closelog();
 900
 901         if (pam_pid > 1) {
 902                 kill(pam_pid, SIGTERM);
 903                 kill(pam_pid, SIGCONT);
 904         }
 905
 906         return err;
 907 }
 908 #endif
 909
 910 static void rename_process_from_path(const char *path) {
 911         char process_name[11];
 912         const char *p;
 913         size_t l;
 914
 915         /* This resulting string must fit in 10 chars (i.e. the length
 916          * of "/sbin/init") to look pretty in /bin/ps */
 917
 918         p = basename(path);
 919         if (isempty(p)) {
 920                 rename_process("(...)");
 921                 return;
 922         }
 923
 924         l = strlen(p);
 925         if (l > 8) {
 926                 /* The end of the process name is usually more
 927                  * interesting, since the first bit might just be
 928                  * "systemd-" */
 929                 p = p + l - 8;
 930                 l = 8;
 931         }
 932
 933         process_name[0] = '(';
 934         memcpy(process_name+1, p, l);
 935         process_name[1+l] = ')';
 936         process_name[1+l+1] = 0;
 937
 938         rename_process(process_name);
 939 }
 940
 941 #ifdef HAVE_SECCOMP
 942
 943 static int apply_seccomp(const ExecContext *c) {
 944         uint32_t negative_action, action;
 945         scmp_filter_ctx *seccomp;
 946         Iterator i;
 947         void *id;
 948         int r;
 949
 950         assert(c);
 951
 952         negative_action = c->syscall_errno == 0 ? SCMP_ACT_KILL : SCMP_ACT_ERRNO(c->syscall_errno);
 953
 954         seccomp = seccomp_init(c->syscall_whitelist ? negative_action : SCMP_ACT_ALLOW);
 955         if (!seccomp)
 956                 return -ENOMEM;
 957
 958         if (c->syscall_archs) {
 959
 960                 SET_FOREACH(id, c->syscall_archs, i) {
 961                         r = seccomp_arch_add(seccomp, PTR_TO_UINT32(id) - 1);
 962                         if (r == -EEXIST)
 963                                 continue;
 964                         if (r < 0)
 965                                 goto finish;
 966                 }
 967
 968         } else {
 969                 r = seccomp_add_secondary_archs(seccomp);
 970                 if (r < 0)
 971                         goto finish;
 972         }
 973
 974         action = c->syscall_whitelist ? SCMP_ACT_ALLOW : negative_action;
 975         SET_FOREACH(id, c->syscall_filter, i) {
 976                 r = seccomp_rule_add(seccomp, action, PTR_TO_INT(id) - 1, 0);
 977                 if (r < 0)
 978                         goto finish;
 979         }
 980
 981         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
 982         if (r < 0)
 983                 goto finish;
 984
 985         r = seccomp_load(seccomp);
 986
 987 finish:
 988         seccomp_release(seccomp);
 989         return r;
 990 }
 991
 992 static int apply_address_families(const ExecContext *c) {
 993         scmp_filter_ctx *seccomp;
 994         Iterator i;
 995         int r;
 996
 997         assert(c);
 998
 999         seccomp = seccomp_init(SCMP_ACT_ALLOW);
1000         if (!seccomp)
1001                 return -ENOMEM;
1002
1003         r = seccomp_add_secondary_archs(seccomp);
1004         if (r < 0)
1005                 goto finish;
1006
1007         if (c->address_families_whitelist) {
1008                 int af, first = 0, last = 0;
1009                 void *afp;
1010
1011                 /* If this is a whitelist, we first block the address
1012                  * families that are out of range and then everything
1013                  * that is not in the set. First, we find the lowest
1014                  * and highest address family in the set. */
1015
1016                 SET_FOREACH(afp, c->address_families, i) {
1017                         af = PTR_TO_INT(afp);
1018
1019                         if (af <= 0 || af >= af_max())
1020                                 continue;
1021
1022                         if (first == 0 || af < first)
1023                                 first = af;
1024
1025                         if (last == 0 || af > last)
1026                                 last = af;
1027                 }
1028
1029                 assert((first == 0) == (last == 0));
1030
1031                 if (first == 0) {
1032
1033                         /* No entries in the valid range, block everything */
1034                         r = seccomp_rule_add(
1035                                         seccomp,
1036                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1037                                         SCMP_SYS(socket),
1038                                         0);
1039                         if (r < 0)
1040                                 goto finish;
1041
1042                 } else {
1043
1044                         /* Block everything below the first entry */
1045                         r = seccomp_rule_add(
1046                                         seccomp,
1047                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1048                                         SCMP_SYS(socket),
1049                                         1,
1050                                         SCMP_A0(SCMP_CMP_LT, first));
1051                         if (r < 0)
1052                                 goto finish;
1053
1054                         /* Block everything above the last entry */
1055                         r = seccomp_rule_add(
1056                                         seccomp,
1057                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1058                                         SCMP_SYS(socket),
1059                                         1,
1060                                         SCMP_A0(SCMP_CMP_GT, last));
1061                         if (r < 0)
1062                                 goto finish;
1063
1064                         /* Block everything between the first and last
1065                          * entry */
1066                         for (af = 1; af < af_max(); af++) {
1067
1068                                 if (set_contains(c->address_families, INT_TO_PTR(af)))
1069                                         continue;
1070
1071                                 r = seccomp_rule_add(
1072                                                 seccomp,
1073                                                 SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1074                                                 SCMP_SYS(socket),
1075                                                 1,
1076                                                 SCMP_A0(SCMP_CMP_EQ, af));
1077                                 if (r < 0)
1078                                         goto finish;
1079                         }
1080                 }
1081
1082         } else {
1083                 void *af;
1084
1085                 /* If this is a blacklist, then generate one rule for
1086                  * each address family that are then combined in OR
1087                  * checks. */
1088
1089                 SET_FOREACH(af, c->address_families, i) {
1090
1091                         r = seccomp_rule_add(
1092                                         seccomp,
1093                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1094                                         SCMP_SYS(socket),
1095                                         1,
1096                                         SCMP_A0(SCMP_CMP_EQ, PTR_TO_INT(af)));
1097                         if (r < 0)
1098                                 goto finish;
1099                 }
1100         }
1101
1102         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
1103         if (r < 0)
1104                 goto finish;
1105
1106         r = seccomp_load(seccomp);
1107
1108 finish:
1109         seccomp_release(seccomp);
1110         return r;
1111 }
1112
1113 #endif
1114
1115 static void do_idle_pipe_dance(int idle_pipe[4]) {
1116         assert(idle_pipe);
1117
1118
1119         safe_close(idle_pipe[1]);
1120         safe_close(idle_pipe[2]);
1121
1122         if (idle_pipe[0] >= 0) {
1123                 int r;
1124
1125                 r = fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT_USEC);
1126
1127                 if (idle_pipe[3] >= 0 && r == 0 /* timeout */) {
1128                         /* Signal systemd that we are bored and want to continue. */
1129                         write(idle_pipe[3], "x", 1);
1130
1131                         /* Wait for systemd to react to the signal above. */
1132                         fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT2_USEC);
1133                 }
1134
1135                 safe_close(idle_pipe[0]);
1136
1137         }
1138
1139         safe_close(idle_pipe[3]);
1140 }
1141
1142 static int build_environment(
1143                 const ExecContext *c,
1144                 unsigned n_fds,
1145                 usec_t watchdog_usec,
1146                 const char *home,
1147                 const char *username,
1148                 const char *shell,
1149                 char ***ret) {
1150
1151         _cleanup_strv_free_ char **our_env = NULL;
1152         unsigned n_env = 0;
1153         char *x;
1154
1155         assert(c);
1156         assert(ret);
1157
1158         our_env = new0(char*, 10);
1159         if (!our_env)
1160                 return -ENOMEM;
1161
1162         if (n_fds > 0) {
1163                 if (asprintf(&x, "LISTEN_PID="PID_FMT, getpid()) < 0)
1164                         return -ENOMEM;
1165                 our_env[n_env++] = x;
1166
1167                 if (asprintf(&x, "LISTEN_FDS=%u", n_fds) < 0)
1168                         return -ENOMEM;
1169                 our_env[n_env++] = x;
1170         }
1171
1172         if (watchdog_usec > 0) {
1173                 if (asprintf(&x, "WATCHDOG_PID="PID_FMT, getpid()) < 0)
1174                         return -ENOMEM;
1175                 our_env[n_env++] = x;
1176
1177                 if (asprintf(&x, "WATCHDOG_USEC="USEC_FMT, watchdog_usec) < 0)
1178                         return -ENOMEM;
1179                 our_env[n_env++] = x;
1180         }
1181
1182         if (home) {
1183                 x = strappend("HOME=", home);
1184                 if (!x)
1185                         return -ENOMEM;
1186                 our_env[n_env++] = x;
1187         }
1188
1189         if (username) {
1190                 x = strappend("LOGNAME=", username);
1191                 if (!x)
1192                         return -ENOMEM;
1193                 our_env[n_env++] = x;
1194
1195                 x = strappend("USER=", username);
1196                 if (!x)
1197                         return -ENOMEM;
1198                 our_env[n_env++] = x;
1199         }
1200
1201         if (shell) {
1202                 x = strappend("SHELL=", shell);
1203                 if (!x)
1204                         return -ENOMEM;
1205                 our_env[n_env++] = x;
1206         }
1207
1208         if (is_terminal_input(c->std_input) ||
1209             c->std_output == EXEC_OUTPUT_TTY ||
1210             c->std_error == EXEC_OUTPUT_TTY ||
1211             c->tty_path) {
1212
1213                 x = strdup(default_term_for_tty(tty_path(c)));
1214                 if (!x)
1215                         return -ENOMEM;
1216                 our_env[n_env++] = x;
1217         }
1218
1219         our_env[n_env++] = NULL;
1220         assert(n_env <= 10);
1221
1222         *ret = our_env;
1223         our_env = NULL;
1224
1225         return 0;
1226 }
1227
1228 static int exec_child(ExecCommand *command,
1229                       const ExecContext *context,
1230                       const ExecParameters *params,
1231                       ExecRuntime *runtime,
1232                       char **argv,
1233                       int socket_fd,
1234                       int *fds, unsigned n_fds,
1235                       char **files_env,
1236                       int *error) {
1237
1238         _cleanup_strv_free_ char **our_env = NULL, **pam_env = NULL, **final_env = NULL, **final_argv = NULL;
1239         const char *username = NULL, *home = NULL, *shell = NULL;
1240         unsigned n_dont_close = 0;
1241         int dont_close[n_fds + 4];
1242         uid_t uid = (uid_t) -1;
1243         gid_t gid = (gid_t) -1;
1244         int i, err;
1245
1246         assert(command);
1247         assert(context);
1248         assert(params);
1249         assert(error);
1250
1251         rename_process_from_path(command->path);
1252
1253         /* We reset exactly these signals, since they are the
1254          * only ones we set to SIG_IGN in the main daemon. All
1255          * others we leave untouched because we set them to
1256          * SIG_DFL or a valid handler initially, both of which
1257          * will be demoted to SIG_DFL. */
1258         default_signals(SIGNALS_CRASH_HANDLER,
1259                         SIGNALS_IGNORE, -1);
1260
1261         if (context->ignore_sigpipe)
1262                 ignore_signals(SIGPIPE, -1);
1263
1264         err = reset_signal_mask();
1265         if (err < 0) {
1266                 *error = EXIT_SIGNAL_MASK;
1267                 return err;
1268         }
1269
1270         if (params->idle_pipe)
1271                 do_idle_pipe_dance(params->idle_pipe);
1272
1273         /* Close sockets very early to make sure we don't
1274          * block init reexecution because it cannot bind its
1275          * sockets */
1276         log_forget_fds();
1277
1278         if (socket_fd >= 0)
1279                 dont_close[n_dont_close++] = socket_fd;
1280         if (n_fds > 0) {
1281                 memcpy(dont_close + n_dont_close, fds, sizeof(int) * n_fds);
1282                 n_dont_close += n_fds;
1283         }
1284         if (params->bus_endpoint_fd >= 0)
1285                 dont_close[n_dont_close++] = params->bus_endpoint_fd;
1286         if (runtime) {
1287                 if (runtime->netns_storage_socket[0] >= 0)
1288                         dont_close[n_dont_close++] = runtime->netns_storage_socket[0];
1289                 if (runtime->netns_storage_socket[1] >= 0)
1290                         dont_close[n_dont_close++] = runtime->netns_storage_socket[1];
1291         }
1292
1293         err = close_all_fds(dont_close, n_dont_close);
1294         if (err < 0) {
1295                 *error = EXIT_FDS;
1296                 return err;
1297         }
1298
1299         if (!context->same_pgrp)
1300                 if (setsid() < 0) {
1301                         *error = EXIT_SETSID;
1302                         return -errno;
1303                 }
1304
1305         exec_context_tty_reset(context);
1306
1307         if (params->confirm_spawn) {
1308                 char response;
1309
1310                 err = ask_for_confirmation(&response, argv);
1311                 if (err == -ETIMEDOUT)
1312                         write_confirm_message("Confirmation question timed out, assuming positive response.\n");
1313                 else if (err < 0)
1314                         write_confirm_message("Couldn't ask confirmation question, assuming positive response: %s\n", strerror(-err));
1315                 else if (response == 's') {
1316                         write_confirm_message("Skipping execution.\n");
1317                         *error = EXIT_CONFIRM;
1318                         return -ECANCELED;
1319                 } else if (response == 'n') {
1320                         write_confirm_message("Failing execution.\n");
1321                         *error = 0;
1322                         return 0;
1323                 }
1324         }
1325
1326         /* If a socket is connected to STDIN/STDOUT/STDERR, we
1327          * must sure to drop O_NONBLOCK */
1328         if (socket_fd >= 0)
1329                 fd_nonblock(socket_fd, false);
1330
1331         err = setup_input(context, socket_fd, params->apply_tty_stdin);
1332         if (err < 0) {
1333                 *error = EXIT_STDIN;
1334                 return err;
1335         }
1336
1337         err = setup_output(context, STDOUT_FILENO, socket_fd, basename(command->path), params->unit_id, params->apply_tty_stdin);
1338         if (err < 0) {
1339                 *error = EXIT_STDOUT;
1340                 return err;
1341         }
1342
1343         err = setup_output(context, STDERR_FILENO, socket_fd, basename(command->path), params->unit_id, params->apply_tty_stdin);
1344         if (err < 0) {
1345                 *error = EXIT_STDERR;
1346                 return err;
1347         }
1348
1349         if (params->cgroup_path) {
1350                 err = cg_attach_everywhere(params->cgroup_supported, params->cgroup_path, 0);
1351                 if (err < 0) {
1352                         *error = EXIT_CGROUP;
1353                         return err;
1354                 }
1355         }
1356
1357         if (context->oom_score_adjust_set) {
1358                 char t[16];
1359
1360                 snprintf(t, sizeof(t), "%i", context->oom_score_adjust);
1361                 char_array_0(t);
1362
1363                 if (write_string_file("/proc/self/oom_score_adj", t) < 0) {
1364                         *error = EXIT_OOM_ADJUST;
1365                         return -errno;
1366                 }
1367         }
1368
1369         if (context->nice_set)
1370                 if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
1371                         *error = EXIT_NICE;
1372                         return -errno;
1373                 }
1374
1375         if (context->cpu_sched_set) {
1376                 struct sched_param param = {
1377                         .sched_priority = context->cpu_sched_priority,
1378                 };
1379
1380                 err = sched_setscheduler(0,
1381                                          context->cpu_sched_policy |
1382                                          (context->cpu_sched_reset_on_fork ?
1383                                           SCHED_RESET_ON_FORK : 0),
1384                                          &param);
1385                 if (err < 0) {
1386                         *error = EXIT_SETSCHEDULER;
1387                         return -errno;
1388                 }
1389         }
1390
1391         if (context->cpuset)
1392                 if (sched_setaffinity(0, CPU_ALLOC_SIZE(context->cpuset_ncpus), context->cpuset) < 0) {
1393                         *error = EXIT_CPUAFFINITY;
1394                         return -errno;
1395                 }
1396
1397         if (context->ioprio_set)
1398                 if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {
1399                         *error = EXIT_IOPRIO;
1400                         return -errno;
1401                 }
1402
1403         if (context->timer_slack_nsec != NSEC_INFINITY)
1404                 if (prctl(PR_SET_TIMERSLACK, context->timer_slack_nsec) < 0) {
1405                         *error = EXIT_TIMERSLACK;
1406                         return -errno;
1407                 }
1408
1409         if (context->personality != 0xffffffffUL)
1410                 if (personality(context->personality) < 0) {
1411                         *error = EXIT_PERSONALITY;
1412                         return -errno;
1413                 }
1414
1415         if (context->utmp_id)
1416                 utmp_put_init_process(context->utmp_id, getpid(), getsid(0), context->tty_path);
1417
1418         if (context->user) {
1419                 username = context->user;
1420                 err = get_user_creds(&username, &uid, &gid, &home, &shell);
1421                 if (err < 0) {
1422                         *error = EXIT_USER;
1423                         return err;
1424                 }
1425
1426                 if (is_terminal_input(context->std_input)) {
1427                         err = chown_terminal(STDIN_FILENO, uid);
1428                         if (err < 0) {
1429                                 *error = EXIT_STDIN;
1430                                 return err;
1431                         }
1432                 }
1433         }
1434
1435 #ifdef ENABLE_KDBUS
1436         if (params->bus_endpoint_fd >= 0 && context->bus_endpoint) {
1437                 uid_t ep_uid = (uid == (uid_t) -1) ? 0 : uid;
1438
1439                 err = bus_kernel_set_endpoint_policy(params->bus_endpoint_fd, ep_uid, context->bus_endpoint);
1440                 if (err < 0) {
1441                         *error = EXIT_BUS_ENDPOINT;
1442                         return err;
1443                 }
1444         }
1445 #endif
1446
1447 #ifdef HAVE_PAM
1448         if (params->cgroup_path && context->user && context->pam_name) {
1449                 err = cg_set_task_access(SYSTEMD_CGROUP_CONTROLLER, params->cgroup_path, 0644, uid, gid);
1450                 if (err < 0) {
1451                         *error = EXIT_CGROUP;
1452                         return err;
1453                 }
1454
1455
1456                 err = cg_set_group_access(SYSTEMD_CGROUP_CONTROLLER, params->cgroup_path, 0755, uid, gid);
1457                 if (err < 0) {
1458                         *error = EXIT_CGROUP;
1459                         return err;
1460                 }
1461         }
1462 #endif
1463
1464         if (!strv_isempty(context->runtime_directory) && params->runtime_prefix) {
1465                 char **rt;
1466
1467                 STRV_FOREACH(rt, context->runtime_directory) {
1468                         _cleanup_free_ char *p;
1469
1470                         p = strjoin(params->runtime_prefix, "/", *rt, NULL);
1471                         if (!p) {
1472                                 *error = EXIT_RUNTIME_DIRECTORY;
1473                                 return -ENOMEM;
1474                         }
1475
1476                         err = mkdir_safe(p, context->runtime_directory_mode, uid, gid);
1477                         if (err < 0) {
1478                                 *error = EXIT_RUNTIME_DIRECTORY;
1479                                 return err;
1480                         }
1481                 }
1482         }
1483
1484         if (params->apply_permissions) {
1485                 err = enforce_groups(context, username, gid);
1486                 if (err < 0) {
1487                         *error = EXIT_GROUP;
1488                         return err;
1489                 }
1490         }
1491
1492         umask(context->umask);
1493
1494 #ifdef HAVE_PAM
1495         if (params->apply_permissions && context->pam_name && username) {
1496                 err = setup_pam(context->pam_name, username, uid, context->tty_path, &pam_env, fds, n_fds);
1497                 if (err < 0) {
1498                         *error = EXIT_PAM;
1499                         return err;
1500                 }
1501         }
1502 #endif
1503
1504         if (context->private_network && runtime && runtime->netns_storage_socket[0] >= 0) {
1505                 err = setup_netns(runtime->netns_storage_socket);
1506                 if (err < 0) {
1507                         *error = EXIT_NETWORK;
1508                         return err;
1509                 }
1510         }
1511
1512         if (!strv_isempty(context->read_write_dirs) ||
1513             !strv_isempty(context->read_only_dirs) ||
1514             !strv_isempty(context->inaccessible_dirs) ||
1515             context->mount_flags != 0 ||
1516             (context->private_tmp && runtime && (runtime->tmp_dir || runtime->var_tmp_dir)) ||
1517             params->bus_endpoint_path ||
1518             context->private_devices ||
1519             context->protect_system != PROTECT_SYSTEM_NO ||
1520             context->protect_home != PROTECT_HOME_NO) {
1521
1522                 char *tmp = NULL, *var = NULL;
1523
1524                 /* The runtime struct only contains the parent
1525                  * of the private /tmp, which is
1526                  * non-accessible to world users. Inside of it
1527                  * there's a /tmp that is sticky, and that's
1528                  * the one we want to use here. */
1529
1530                 if (context->private_tmp && runtime) {
1531                         if (runtime->tmp_dir)
1532                                 tmp = strappenda(runtime->tmp_dir, "/tmp");
1533                         if (runtime->var_tmp_dir)
1534                                 var = strappenda(runtime->var_tmp_dir, "/tmp");
1535                 }
1536
1537                 err = setup_namespace(
1538                                 context->read_write_dirs,
1539                                 context->read_only_dirs,
1540                                 context->inaccessible_dirs,
1541                                 tmp,
1542                                 var,
1543                                 params->bus_endpoint_path,
1544                                 context->private_devices,
1545                                 context->protect_home,
1546                                 context->protect_system,
1547                                 context->mount_flags);
1548                 if (err < 0) {
1549                         *error = EXIT_NAMESPACE;
1550                         return err;
1551                 }
1552         }
1553
1554         if (params->apply_chroot) {
1555                 if (context->root_directory)
1556                         if (chroot(context->root_directory) < 0) {
1557                                 *error = EXIT_CHROOT;
1558                                 return -errno;
1559                         }
1560
1561                 if (chdir(context->working_directory ? context->working_directory : "/") < 0) {
1562                         *error = EXIT_CHDIR;
1563                         return -errno;
1564                 }
1565         } else {
1566                 _cleanup_free_ char *d = NULL;
1567
1568                 if (asprintf(&d, "%s/%s",
1569                              context->root_directory ? context->root_directory : "",
1570                              context->working_directory ? context->working_directory : "") < 0) {
1571                         *error = EXIT_MEMORY;
1572                         return -ENOMEM;
1573                 }
1574
1575                 if (chdir(d) < 0) {
1576                         *error = EXIT_CHDIR;
1577                         return -errno;
1578                 }
1579         }
1580
1581         /* We repeat the fd closing here, to make sure that
1582          * nothing is leaked from the PAM modules. Note that
1583          * we are more aggressive this time since socket_fd
1584          * and the netns fds we don't need anymore. The custom
1585          * endpoint fd was needed to upload the policy and can
1586          * now be closed as well. */
1587         err = close_all_fds(fds, n_fds);
1588         if (err >= 0)
1589                 err = shift_fds(fds, n_fds);
1590         if (err >= 0)
1591                 err = flags_fds(fds, n_fds, context->non_blocking);
1592         if (err < 0) {
1593                 *error = EXIT_FDS;
1594                 return err;
1595         }
1596
1597         if (params->apply_permissions) {
1598
1599                 for (i = 0; i < _RLIMIT_MAX; i++) {
1600                         if (!context->rlimit[i])
1601                                 continue;
1602
1603                         if (setrlimit_closest(i, context->rlimit[i]) < 0) {
1604                                 *error = EXIT_LIMITS;
1605                                 return -errno;
1606                         }
1607                 }
1608
1609                 if (context->capability_bounding_set_drop) {
1610                         err = capability_bounding_set_drop(context->capability_bounding_set_drop, false);
1611                         if (err < 0) {
1612                                 *error = EXIT_CAPABILITIES;
1613                                 return err;
1614                         }
1615                 }
1616
1617                 if (context->user) {
1618                         err = enforce_user(context, uid);
1619                         if (err < 0) {
1620                                 *error = EXIT_USER;
1621                                 return err;
1622                         }
1623                 }
1624
1625                 /* PR_GET_SECUREBITS is not privileged, while
1626                  * PR_SET_SECUREBITS is. So to suppress
1627                  * potential EPERMs we'll try not to call
1628                  * PR_SET_SECUREBITS unless necessary. */
1629                 if (prctl(PR_GET_SECUREBITS) != context->secure_bits)
1630                         if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) {
1631                                 *error = EXIT_SECUREBITS;
1632                                 return -errno;
1633                         }
1634
1635                 if (context->capabilities)
1636                         if (cap_set_proc(context->capabilities) < 0) {
1637                                 *error = EXIT_CAPABILITIES;
1638                                 return -errno;
1639                         }
1640
1641                 if (context->no_new_privileges)
1642                         if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
1643                                 *error = EXIT_NO_NEW_PRIVILEGES;
1644                                 return -errno;
1645                         }
1646
1647 #ifdef HAVE_SECCOMP
1648                 if (context->address_families_whitelist ||
1649                     !set_isempty(context->address_families)) {
1650                         err = apply_address_families(context);
1651                         if (err < 0) {
1652                                 *error = EXIT_ADDRESS_FAMILIES;
1653                                 return err;
1654                         }
1655                 }
1656
1657                 if (context->syscall_whitelist ||
1658                     !set_isempty(context->syscall_filter) ||
1659                     !set_isempty(context->syscall_archs)) {
1660                         err = apply_seccomp(context);
1661                         if (err < 0) {
1662                                 *error = EXIT_SECCOMP;
1663                                 return err;
1664                         }
1665                 }
1666 #endif
1667
1668 #ifdef HAVE_SELINUX
1669                 if (use_selinux()) {
1670                         if (context->selinux_context) {
1671                                 err = setexeccon(context->selinux_context);
1672                                 if (err < 0 && !context->selinux_context_ignore) {
1673                                         *error = EXIT_SELINUX_CONTEXT;
1674                                         return err;
1675                                 }
1676                         }
1677
1678                         if (params->selinux_context_net && socket_fd >= 0) {
1679                                 _cleanup_free_ char *label = NULL;
1680
1681                                 err = label_get_child_mls_label(socket_fd, command->path, &label);
1682                                 if (err < 0) {
1683                                         *error = EXIT_SELINUX_CONTEXT;
1684                                         return err;
1685                                 }
1686
1687                                 err = setexeccon(label);
1688                                 if (err < 0) {
1689                                         *error = EXIT_SELINUX_CONTEXT;
1690                                         return err;
1691                                 }
1692                         }
1693                 }
1694 #endif
1695
1696 #ifdef HAVE_APPARMOR
1697                 if (context->apparmor_profile && use_apparmor()) {
1698                         err = aa_change_onexec(context->apparmor_profile);
1699                         if (err < 0 && !context->apparmor_profile_ignore) {
1700                                 *error = EXIT_APPARMOR_PROFILE;
1701                                 return err;
1702                         }
1703                 }
1704 #endif
1705         }
1706
1707         err = build_environment(context, n_fds, params->watchdog_usec, home, username, shell, &our_env);
1708         if (err < 0) {
1709                 *error = EXIT_MEMORY;
1710                 return err;
1711         }
1712
1713         final_env = strv_env_merge(5,
1714                                    params->environment,
1715                                    our_env,
1716                                    context->environment,
1717                                    files_env,
1718                                    pam_env,
1719                                    NULL);
1720         if (!final_env) {
1721                 *error = EXIT_MEMORY;
1722                 return -ENOMEM;
1723         }
1724
1725         final_argv = replace_env_argv(argv, final_env);
1726         if (!final_argv) {
1727                 *error = EXIT_MEMORY;
1728                 return -ENOMEM;
1729         }
1730
1731         final_env = strv_env_clean(final_env);
1732
1733         if (_unlikely_(log_get_max_level() >= LOG_PRI(LOG_DEBUG))) {
1734                 _cleanup_free_ char *line;
1735
1736                 line = exec_command_line(final_argv);
1737                 if (line) {
1738                         log_open();
1739                         log_struct_unit(LOG_DEBUG,
1740                                         params->unit_id,
1741                                         "EXECUTABLE=%s", command->path,
1742                                         "MESSAGE=Executing: %s", line,
1743                                         NULL);
1744                         log_close();
1745                 }
1746         }
1747         execve(command->path, final_argv, final_env);
1748         *error = EXIT_EXEC;
1749         return -errno;
1750 }
1751
1752 int exec_spawn(ExecCommand *command,
1753                const ExecContext *context,
1754                const ExecParameters *params,
1755                ExecRuntime *runtime,
1756                pid_t *ret) {
1757
1758         _cleanup_strv_free_ char **files_env = NULL;
1759         int *fds = NULL; unsigned n_fds = 0;
1760         char *line, **argv;
1761         int socket_fd;
1762         pid_t pid;
1763         int err;
1764
1765         assert(command);
1766         assert(context);
1767         assert(ret);
1768         assert(params);
1769         assert(params->fds || params->n_fds <= 0);
1770
1771         if (context->std_input == EXEC_INPUT_SOCKET ||
1772             context->std_output == EXEC_OUTPUT_SOCKET ||
1773             context->std_error == EXEC_OUTPUT_SOCKET) {
1774
1775                 if (params->n_fds != 1)
1776                         return -EINVAL;
1777
1778                 socket_fd = params->fds[0];
1779         } else {
1780                 socket_fd = -1;
1781                 fds = params->fds;
1782                 n_fds = params->n_fds;
1783         }
1784
1785         err = exec_context_load_environment(context, &files_env);
1786         if (err < 0) {
1787                 log_struct_unit(LOG_ERR,
1788                            params->unit_id,
1789                            "MESSAGE=Failed to load environment files: %s", strerror(-err),
1790                            "ERRNO=%d", -err,
1791                            NULL);
1792                 return err;
1793         }
1794
1795         argv = params->argv ?: command->argv;
1796
1797         line = exec_command_line(argv);
1798         if (!line)
1799                 return log_oom();
1800
1801         log_struct_unit(LOG_DEBUG,
1802                         params->unit_id,
1803                         "EXECUTABLE=%s", command->path,
1804                         "MESSAGE=About to execute: %s", line,
1805                         NULL);
1806         free(line);
1807
1808         pid = fork();
1809         if (pid < 0)
1810                 return -errno;
1811
1812         if (pid == 0) {
1813                 int r;
1814
1815                 err = exec_child(command,
1816                                  context,
1817                                  params,
1818                                  runtime,
1819                                  argv,
1820                                  socket_fd,
1821                                  fds, n_fds,
1822                                  files_env,
1823                                  &r);
1824                 if (r != 0) {
1825                         log_open();
1826                         log_struct(LOG_ERR, MESSAGE_ID(SD_MESSAGE_SPAWN_FAILED),
1827                                    "EXECUTABLE=%s", command->path,
1828                                    "MESSAGE=Failed at step %s spawning %s: %s",
1829                                           exit_status_to_string(r, EXIT_STATUS_SYSTEMD),
1830                                           command->path, strerror(-err),
1831                                    "ERRNO=%d", -err,
1832                                    NULL);
1833                         log_close();
1834                 }
1835
1836                 _exit(r);
1837         }
1838
1839         log_struct_unit(LOG_DEBUG,
1840                         params->unit_id,
1841                         "MESSAGE=Forked %s as "PID_FMT,
1842                         command->path, pid,
1843                         NULL);
1844
1845         /* We add the new process to the cgroup both in the child (so
1846          * that we can be sure that no user code is ever executed
1847          * outside of the cgroup) and in the parent (so that we can be
1848          * sure that when we kill the cgroup the process will be
1849          * killed too). */
1850         if (params->cgroup_path)
1851                 cg_attach(SYSTEMD_CGROUP_CONTROLLER, params->cgroup_path, pid);
1852
1853         exec_status_start(&command->exec_status, pid);
1854
1855         *ret = pid;
1856         return 0;
1857 }
1858
1859 void exec_context_init(ExecContext *c) {
1860         assert(c);
1861
1862         c->umask = 0022;
1863         c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);
1864         c->cpu_sched_policy = SCHED_OTHER;
1865         c->syslog_priority = LOG_DAEMON|LOG_INFO;
1866         c->syslog_level_prefix = true;
1867         c->ignore_sigpipe = true;
1868         c->timer_slack_nsec = NSEC_INFINITY;
1869         c->personality = 0xffffffffUL;
1870         c->runtime_directory_mode = 0755;
1871 }
1872
1873 void exec_context_done(ExecContext *c) {
1874         unsigned l;
1875
1876         assert(c);
1877
1878         strv_free(c->environment);
1879         c->environment = NULL;
1880
1881         strv_free(c->environment_files);
1882         c->environment_files = NULL;
1883
1884         for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {
1885                 free(c->rlimit[l]);
1886                 c->rlimit[l] = NULL;
1887         }
1888
1889         free(c->working_directory);
1890         c->working_directory = NULL;
1891         free(c->root_directory);
1892         c->root_directory = NULL;
1893
1894         free(c->tty_path);
1895         c->tty_path = NULL;
1896
1897         free(c->syslog_identifier);
1898         c->syslog_identifier = NULL;
1899
1900         free(c->user);
1901         c->user = NULL;
1902
1903         free(c->group);
1904         c->group = NULL;
1905
1906         strv_free(c->supplementary_groups);
1907         c->supplementary_groups = NULL;
1908
1909         free(c->pam_name);
1910         c->pam_name = NULL;
1911
1912         if (c->capabilities) {
1913                 cap_free(c->capabilities);
1914                 c->capabilities = NULL;
1915         }
1916
1917         strv_free(c->read_only_dirs);
1918         c->read_only_dirs = NULL;
1919
1920         strv_free(c->read_write_dirs);
1921         c->read_write_dirs = NULL;
1922
1923         strv_free(c->inaccessible_dirs);
1924         c->inaccessible_dirs = NULL;
1925
1926         if (c->cpuset)
1927                 CPU_FREE(c->cpuset);
1928
1929         free(c->utmp_id);
1930         c->utmp_id = NULL;
1931
1932         free(c->selinux_context);
1933         c->selinux_context = NULL;
1934
1935         free(c->apparmor_profile);
1936         c->apparmor_profile = NULL;
1937
1938         set_free(c->syscall_filter);
1939         c->syscall_filter = NULL;
1940
1941         set_free(c->syscall_archs);
1942         c->syscall_archs = NULL;
1943
1944         set_free(c->address_families);
1945         c->address_families = NULL;
1946
1947         strv_free(c->runtime_directory);
1948         c->runtime_directory = NULL;
1949
1950         bus_endpoint_free(c->bus_endpoint);
1951         c->bus_endpoint = NULL;
1952 }
1953
1954 int exec_context_destroy_runtime_directory(ExecContext *c, const char *runtime_prefix) {
1955         char **i;
1956
1957         assert(c);
1958
1959         if (!runtime_prefix)
1960                 return 0;
1961
1962         STRV_FOREACH(i, c->runtime_directory) {
1963                 _cleanup_free_ char *p;
1964
1965                 p = strjoin(runtime_prefix, "/", *i, NULL);
1966                 if (!p)
1967                         return -ENOMEM;
1968
1969                 /* We execute this synchronously, since we need to be
1970                  * sure this is gone when we start the service
1971                  * next. */
1972                 rm_rf_dangerous(p, false, true, false);
1973         }
1974
1975         return 0;
1976 }
1977
1978 void exec_command_done(ExecCommand *c) {
1979         assert(c);
1980
1981         free(c->path);
1982         c->path = NULL;
1983
1984         strv_free(c->argv);
1985         c->argv = NULL;
1986 }
1987
1988 void exec_command_done_array(ExecCommand *c, unsigned n) {
1989         unsigned i;
1990
1991         for (i = 0; i < n; i++)
1992                 exec_command_done(c+i);
1993 }
1994
1995 void exec_command_free_list(ExecCommand *c) {
1996         ExecCommand *i;
1997
1998         while ((i = c)) {
1999                 LIST_REMOVE(command, c, i);
2000                 exec_command_done(i);
2001                 free(i);
2002         }
2003 }
2004
2005 void exec_command_free_array(ExecCommand **c, unsigned n) {
2006         unsigned i;
2007
2008         for (i = 0; i < n; i++) {
2009                 exec_command_free_list(c[i]);
2010                 c[i] = NULL;
2011         }
2012 }
2013
2014 int exec_context_load_environment(const ExecContext *c, char ***l) {
2015         char **i, **r = NULL;
2016
2017         assert(c);
2018         assert(l);
2019
2020         STRV_FOREACH(i, c->environment_files) {
2021                 char *fn;
2022                 int k;
2023                 bool ignore = false;
2024                 char **p;
2025                 _cleanup_globfree_ glob_t pglob = {};
2026                 int count, n;
2027
2028                 fn = *i;
2029
2030                 if (fn[0] == '-') {
2031                         ignore = true;
2032                         fn ++;
2033                 }
2034
2035                 if (!path_is_absolute(fn)) {
2036                         if (ignore)
2037                                 continue;
2038
2039                         strv_free(r);
2040                         return -EINVAL;
2041                 }
2042
2043                 /* Filename supports globbing, take all matching files */
2044                 errno = 0;
2045                 if (glob(fn, 0, NULL, &pglob) != 0) {
2046                         if (ignore)
2047                                 continue;
2048
2049                         strv_free(r);
2050                         return errno ? -errno : -EINVAL;
2051                 }
2052                 count = pglob.gl_pathc;
2053                 if (count == 0) {
2054                         if (ignore)
2055                                 continue;
2056
2057                         strv_free(r);
2058                         return -EINVAL;
2059                 }
2060                 for (n = 0; n < count; n++) {
2061                         k = load_env_file(NULL, pglob.gl_pathv[n], NULL, &p);
2062                         if (k < 0) {
2063                                 if (ignore)
2064                                         continue;
2065
2066                                 strv_free(r);
2067                                 return k;
2068                         }
2069                         /* Log invalid environment variables with filename */
2070                         if (p)
2071                                 p = strv_env_clean_log(p, pglob.gl_pathv[n]);
2072
2073                         if (r == NULL)
2074                                 r = p;
2075                         else {
2076                                 char **m;
2077
2078                                 m = strv_env_merge(2, r, p);
2079                                 strv_free(r);
2080                                 strv_free(p);
2081                                 if (!m)
2082                                         return -ENOMEM;
2083
2084                                 r = m;
2085                         }
2086                 }
2087         }
2088
2089         *l = r;
2090
2091         return 0;
2092 }
2093
2094 static bool tty_may_match_dev_console(const char *tty) {
2095         _cleanup_free_ char *active = NULL;
2096        char *console;
2097
2098         if (startswith(tty, "/dev/"))
2099                 tty += 5;
2100
2101         /* trivial identity? */
2102         if (streq(tty, "console"))
2103                 return true;
2104
2105         console = resolve_dev_console(&active);
2106         /* if we could not resolve, assume it may */
2107         if (!console)
2108                 return true;
2109
2110         /* "tty0" means the active VC, so it may be the same sometimes */
2111         return streq(console, tty) || (streq(console, "tty0") && tty_is_vc(tty));
2112 }
2113
2114 bool exec_context_may_touch_console(ExecContext *ec) {
2115         return (ec->tty_reset || ec->tty_vhangup || ec->tty_vt_disallocate ||
2116                 is_terminal_input(ec->std_input) ||
2117                 is_terminal_output(ec->std_output) ||
2118                 is_terminal_output(ec->std_error)) &&
2119                tty_may_match_dev_console(tty_path(ec));
2120 }
2121
2122 static void strv_fprintf(FILE *f, char **l) {
2123         char **g;
2124
2125         assert(f);
2126
2127         STRV_FOREACH(g, l)
2128                 fprintf(f, " %s", *g);
2129 }
2130
2131 void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
2132         char **e;
2133         unsigned i;
2134
2135         assert(c);
2136         assert(f);
2137
2138         prefix = strempty(prefix);
2139
2140         fprintf(f,
2141                 "%sUMask: %04o\n"
2142                 "%sWorkingDirectory: %s\n"
2143                 "%sRootDirectory: %s\n"
2144                 "%sNonBlocking: %s\n"
2145                 "%sPrivateTmp: %s\n"
2146                 "%sPrivateNetwork: %s\n"
2147                 "%sPrivateDevices: %s\n"
2148                 "%sProtectHome: %s\n"
2149                 "%sProtectSystem: %s\n"
2150                 "%sIgnoreSIGPIPE: %s\n",
2151                 prefix, c->umask,
2152                 prefix, c->working_directory ? c->working_directory : "/",
2153                 prefix, c->root_directory ? c->root_directory : "/",
2154                 prefix, yes_no(c->non_blocking),
2155                 prefix, yes_no(c->private_tmp),
2156                 prefix, yes_no(c->private_network),
2157                 prefix, yes_no(c->private_devices),
2158                 prefix, protect_home_to_string(c->protect_home),
2159                 prefix, protect_system_to_string(c->protect_system),
2160                 prefix, yes_no(c->ignore_sigpipe));
2161
2162         STRV_FOREACH(e, c->environment)
2163                 fprintf(f, "%sEnvironment: %s\n", prefix, *e);
2164
2165         STRV_FOREACH(e, c->environment_files)
2166                 fprintf(f, "%sEnvironmentFile: %s\n", prefix, *e);
2167
2168         if (c->nice_set)
2169                 fprintf(f,
2170                         "%sNice: %i\n",
2171                         prefix, c->nice);
2172
2173         if (c->oom_score_adjust_set)
2174                 fprintf(f,
2175                         "%sOOMScoreAdjust: %i\n",
2176                         prefix, c->oom_score_adjust);
2177
2178         for (i = 0; i < RLIM_NLIMITS; i++)
2179                 if (c->rlimit[i])
2180                         fprintf(f, "%s%s: "RLIM_FMT"\n",
2181                                 prefix, rlimit_to_string(i), c->rlimit[i]->rlim_max);
2182
2183         if (c->ioprio_set) {
2184                 _cleanup_free_ char *class_str = NULL;
2185
2186                 ioprio_class_to_string_alloc(IOPRIO_PRIO_CLASS(c->ioprio), &class_str);
2187                 fprintf(f,
2188                         "%sIOSchedulingClass: %s\n"
2189                         "%sIOPriority: %i\n",
2190                         prefix, strna(class_str),
2191                         prefix, (int) IOPRIO_PRIO_DATA(c->ioprio));
2192         }
2193
2194         if (c->cpu_sched_set) {
2195                 _cleanup_free_ char *policy_str = NULL;
2196
2197                 sched_policy_to_string_alloc(c->cpu_sched_policy, &policy_str);
2198                 fprintf(f,
2199                         "%sCPUSchedulingPolicy: %s\n"
2200                         "%sCPUSchedulingPriority: %i\n"
2201                         "%sCPUSchedulingResetOnFork: %s\n",
2202                         prefix, strna(policy_str),
2203                         prefix, c->cpu_sched_priority,
2204                         prefix, yes_no(c->cpu_sched_reset_on_fork));
2205         }
2206
2207         if (c->cpuset) {
2208                 fprintf(f, "%sCPUAffinity:", prefix);
2209                 for (i = 0; i < c->cpuset_ncpus; i++)
2210                         if (CPU_ISSET_S(i, CPU_ALLOC_SIZE(c->cpuset_ncpus), c->cpuset))
2211                                 fprintf(f, " %u", i);
2212                 fputs("\n", f);
2213         }
2214
2215         if (c->timer_slack_nsec != NSEC_INFINITY)
2216                 fprintf(f, "%sTimerSlackNSec: "NSEC_FMT "\n", prefix, c->timer_slack_nsec);
2217
2218         fprintf(f,
2219                 "%sStandardInput: %s\n"
2220                 "%sStandardOutput: %s\n"
2221                 "%sStandardError: %s\n",
2222                 prefix, exec_input_to_string(c->std_input),
2223                 prefix, exec_output_to_string(c->std_output),
2224                 prefix, exec_output_to_string(c->std_error));
2225
2226         if (c->tty_path)
2227                 fprintf(f,
2228                         "%sTTYPath: %s\n"
2229                         "%sTTYReset: %s\n"
2230                         "%sTTYVHangup: %s\n"
2231                         "%sTTYVTDisallocate: %s\n",
2232                         prefix, c->tty_path,
2233                         prefix, yes_no(c->tty_reset),
2234                         prefix, yes_no(c->tty_vhangup),
2235                         prefix, yes_no(c->tty_vt_disallocate));
2236
2237         if (c->std_output == EXEC_OUTPUT_SYSLOG ||
2238             c->std_output == EXEC_OUTPUT_KMSG ||
2239             c->std_output == EXEC_OUTPUT_JOURNAL ||
2240             c->std_output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE ||
2241             c->std_output == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
2242             c->std_output == EXEC_OUTPUT_JOURNAL_AND_CONSOLE ||
2243             c->std_error == EXEC_OUTPUT_SYSLOG ||
2244             c->std_error == EXEC_OUTPUT_KMSG ||
2245             c->std_error == EXEC_OUTPUT_JOURNAL ||
2246             c->std_error == EXEC_OUTPUT_SYSLOG_AND_CONSOLE ||
2247             c->std_error == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
2248             c->std_error == EXEC_OUTPUT_JOURNAL_AND_CONSOLE) {
2249
2250                 _cleanup_free_ char *fac_str = NULL, *lvl_str = NULL;
2251
2252                 log_facility_unshifted_to_string_alloc(c->syslog_priority >> 3, &fac_str);
2253                 log_level_to_string_alloc(LOG_PRI(c->syslog_priority), &lvl_str);
2254
2255                 fprintf(f,
2256                         "%sSyslogFacility: %s\n"
2257                         "%sSyslogLevel: %s\n",
2258                         prefix, strna(fac_str),
2259                         prefix, strna(lvl_str));
2260         }
2261
2262         if (c->capabilities) {
2263                 _cleanup_cap_free_charp_ char *t;
2264
2265                 t = cap_to_text(c->capabilities, NULL);
2266                 if (t)
2267                         fprintf(f, "%sCapabilities: %s\n", prefix, t);
2268         }
2269
2270         if (c->secure_bits)
2271                 fprintf(f, "%sSecure Bits:%s%s%s%s%s%s\n",
2272                         prefix,
2273                         (c->secure_bits & 1<<SECURE_KEEP_CAPS) ? " keep-caps" : "",
2274                         (c->secure_bits & 1<<SECURE_KEEP_CAPS_LOCKED) ? " keep-caps-locked" : "",
2275                         (c->secure_bits & 1<<SECURE_NO_SETUID_FIXUP) ? " no-setuid-fixup" : "",
2276                         (c->secure_bits & 1<<SECURE_NO_SETUID_FIXUP_LOCKED) ? " no-setuid-fixup-locked" : "",
2277                         (c->secure_bits & 1<<SECURE_NOROOT) ? " noroot" : "",
2278                         (c->secure_bits & 1<<SECURE_NOROOT_LOCKED) ? "noroot-locked" : "");
2279
2280         if (c->capability_bounding_set_drop) {
2281                 unsigned long l;
2282                 fprintf(f, "%sCapabilityBoundingSet:", prefix);
2283
2284                 for (l = 0; l <= cap_last_cap(); l++)
2285                         if (!(c->capability_bounding_set_drop & ((uint64_t) 1ULL << (uint64_t) l))) {
2286                                 _cleanup_cap_free_charp_ char *t;
2287
2288                                 t = cap_to_name(l);
2289                                 if (t)
2290                                         fprintf(f, " %s", t);
2291                         }
2292
2293                 fputs("\n", f);
2294         }
2295
2296         if (c->user)
2297                 fprintf(f, "%sUser: %s\n", prefix, c->user);
2298         if (c->group)
2299                 fprintf(f, "%sGroup: %s\n", prefix, c->group);
2300
2301         if (strv_length(c->supplementary_groups) > 0) {
2302                 fprintf(f, "%sSupplementaryGroups:", prefix);
2303                 strv_fprintf(f, c->supplementary_groups);
2304                 fputs("\n", f);
2305         }
2306
2307         if (c->pam_name)
2308                 fprintf(f, "%sPAMName: %s\n", prefix, c->pam_name);
2309
2310         if (strv_length(c->read_write_dirs) > 0) {
2311                 fprintf(f, "%sReadWriteDirs:", prefix);
2312                 strv_fprintf(f, c->read_write_dirs);
2313                 fputs("\n", f);
2314         }
2315
2316         if (strv_length(c->read_only_dirs) > 0) {
2317                 fprintf(f, "%sReadOnlyDirs:", prefix);
2318                 strv_fprintf(f, c->read_only_dirs);
2319                 fputs("\n", f);
2320         }
2321
2322         if (strv_length(c->inaccessible_dirs) > 0) {
2323                 fprintf(f, "%sInaccessibleDirs:", prefix);
2324                 strv_fprintf(f, c->inaccessible_dirs);
2325                 fputs("\n", f);
2326         }
2327
2328         if (c->utmp_id)
2329                 fprintf(f,
2330                         "%sUtmpIdentifier: %s\n",
2331                         prefix, c->utmp_id);
2332
2333         if (c->selinux_context)
2334                 fprintf(f,
2335                         "%sSELinuxContext: %s%s\n",
2336                         prefix, c->selinux_context_ignore ? "-" : "", c->selinux_context);
2337
2338         if (c->personality != 0xffffffffUL)
2339                 fprintf(f,
2340                         "%sPersonality: %s\n",
2341                         prefix, strna(personality_to_string(c->personality)));
2342
2343         if (c->syscall_filter) {
2344 #ifdef HAVE_SECCOMP
2345                 Iterator j;
2346                 void *id;
2347                 bool first = true;
2348 #endif
2349
2350                 fprintf(f,
2351                         "%sSystemCallFilter: ",
2352                         prefix);
2353
2354                 if (!c->syscall_whitelist)
2355                         fputc('~', f);
2356
2357 #ifdef HAVE_SECCOMP
2358                 SET_FOREACH(id, c->syscall_filter, j) {
2359                         _cleanup_free_ char *name = NULL;
2360
2361                         if (first)
2362                                 first = false;
2363                         else
2364                                 fputc(' ', f);
2365
2366                         name = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE, PTR_TO_INT(id) - 1);
2367                         fputs(strna(name), f);
2368                 }
2369 #endif
2370
2371                 fputc('\n', f);
2372         }
2373
2374         if (c->syscall_archs) {
2375 #ifdef HAVE_SECCOMP
2376                 Iterator j;
2377                 void *id;
2378 #endif
2379
2380                 fprintf(f,
2381                         "%sSystemCallArchitectures:",
2382                         prefix);
2383
2384 #ifdef HAVE_SECCOMP
2385                 SET_FOREACH(id, c->syscall_archs, j)
2386                         fprintf(f, " %s", strna(seccomp_arch_to_string(PTR_TO_UINT32(id) - 1)));
2387 #endif
2388                 fputc('\n', f);
2389         }
2390
2391         if (c->syscall_errno != 0)
2392                 fprintf(f,
2393                         "%sSystemCallErrorNumber: %s\n",
2394                         prefix, strna(errno_to_name(c->syscall_errno)));
2395
2396         if (c->apparmor_profile)
2397                 fprintf(f,
2398                         "%sAppArmorProfile: %s%s\n",
2399                         prefix, c->apparmor_profile_ignore ? "-" : "", c->apparmor_profile);
2400 }
2401
2402 void exec_status_start(ExecStatus *s, pid_t pid) {
2403         assert(s);
2404
2405         zero(*s);
2406         s->pid = pid;
2407         dual_timestamp_get(&s->start_timestamp);
2408 }
2409
2410 void exec_status_exit(ExecStatus *s, ExecContext *context, pid_t pid, int code, int status) {
2411         assert(s);
2412
2413         if (s->pid && s->pid != pid)
2414                 zero(*s);
2415
2416         s->pid = pid;
2417         dual_timestamp_get(&s->exit_timestamp);
2418
2419         s->code = code;
2420         s->status = status;
2421
2422         if (context) {
2423                 if (context->utmp_id)
2424                         utmp_put_dead_process(context->utmp_id, pid, code, status);
2425
2426                 exec_context_tty_reset(context);
2427         }
2428 }
2429
2430 void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix) {
2431         char buf[FORMAT_TIMESTAMP_MAX];
2432
2433         assert(s);
2434         assert(f);
2435
2436         if (s->pid <= 0)
2437                 return;
2438
2439         prefix = strempty(prefix);
2440
2441         fprintf(f,
2442                 "%sPID: "PID_FMT"\n",
2443                 prefix, s->pid);
2444
2445         if (s->start_timestamp.realtime > 0)
2446                 fprintf(f,
2447                         "%sStart Timestamp: %s\n",
2448                         prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp.realtime));
2449
2450         if (s->exit_timestamp.realtime > 0)
2451                 fprintf(f,
2452                         "%sExit Timestamp: %s\n"
2453                         "%sExit Code: %s\n"
2454                         "%sExit Status: %i\n",
2455                         prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp.realtime),
2456                         prefix, sigchld_code_to_string(s->code),
2457                         prefix, s->status);
2458 }
2459
2460 char *exec_command_line(char **argv) {
2461         size_t k;
2462         char *n, *p, **a;
2463         bool first = true;
2464
2465         assert(argv);
2466
2467         k = 1;
2468         STRV_FOREACH(a, argv)
2469                 k += strlen(*a)+3;
2470
2471         if (!(n = new(char, k)))
2472                 return NULL;
2473
2474         p = n;
2475         STRV_FOREACH(a, argv) {
2476
2477                 if (!first)
2478                         *(p++) = ' ';
2479                 else
2480                         first = false;
2481
2482                 if (strpbrk(*a, WHITESPACE)) {
2483                         *(p++) = '\'';
2484                         p = stpcpy(p, *a);
2485                         *(p++) = '\'';
2486                 } else
2487                         p = stpcpy(p, *a);
2488
2489         }
2490
2491         *p = 0;
2492
2493         /* FIXME: this doesn't really handle arguments that have
2494          * spaces and ticks in them */
2495
2496         return n;
2497 }
2498
2499 void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
2500         _cleanup_free_ char *cmd = NULL;
2501         const char *prefix2;
2502
2503         assert(c);
2504         assert(f);
2505
2506         prefix = strempty(prefix);
2507         prefix2 = strappenda(prefix, "\t");
2508
2509         cmd = exec_command_line(c->argv);
2510         fprintf(f,
2511                 "%sCommand Line: %s\n",
2512                 prefix, cmd ? cmd : strerror(ENOMEM));
2513
2514         exec_status_dump(&c->exec_status, f, prefix2);
2515 }
2516
2517 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
2518         assert(f);
2519
2520         prefix = strempty(prefix);
2521
2522         LIST_FOREACH(command, c, c)
2523                 exec_command_dump(c, f, prefix);
2524 }
2525
2526 void exec_command_append_list(ExecCommand **l, ExecCommand *e) {
2527         ExecCommand *end;
2528
2529         assert(l);
2530         assert(e);
2531
2532         if (*l) {
2533                 /* It's kind of important, that we keep the order here */
2534                 LIST_FIND_TAIL(command, *l, end);
2535                 LIST_INSERT_AFTER(command, *l, end, e);
2536         } else
2537               *l = e;
2538 }
2539
2540 int exec_command_set(ExecCommand *c, const char *path, ...) {
2541         va_list ap;
2542         char **l, *p;
2543
2544         assert(c);
2545         assert(path);
2546
2547         va_start(ap, path);
2548         l = strv_new_ap(path, ap);
2549         va_end(ap);
2550
2551         if (!l)
2552                 return -ENOMEM;
2553
2554         p = strdup(path);
2555         if (!p) {
2556                 strv_free(l);
2557                 return -ENOMEM;
2558         }
2559
2560         free(c->path);
2561         c->path = p;
2562
2563         strv_free(c->argv);
2564         c->argv = l;
2565
2566         return 0;
2567 }
2568
2569 static int exec_runtime_allocate(ExecRuntime **rt) {
2570
2571         if (*rt)
2572                 return 0;
2573
2574         *rt = new0(ExecRuntime, 1);
2575         if (!*rt)
2576                 return -ENOMEM;
2577
2578         (*rt)->n_ref = 1;
2579         (*rt)->netns_storage_socket[0] = (*rt)->netns_storage_socket[1] = -1;
2580
2581         return 0;
2582 }
2583
2584 int exec_runtime_make(ExecRuntime **rt, ExecContext *c, const char *id) {
2585         int r;
2586
2587         assert(rt);
2588         assert(c);
2589         assert(id);
2590
2591         if (*rt)
2592                 return 1;
2593
2594         if (!c->private_network && !c->private_tmp)
2595                 return 0;
2596
2597         r = exec_runtime_allocate(rt);
2598         if (r < 0)
2599                 return r;
2600
2601         if (c->private_network && (*rt)->netns_storage_socket[0] < 0) {
2602                 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, (*rt)->netns_storage_socket) < 0)
2603                         return -errno;
2604         }
2605
2606         if (c->private_tmp && !(*rt)->tmp_dir) {
2607                 r = setup_tmp_dirs(id, &(*rt)->tmp_dir, &(*rt)->var_tmp_dir);
2608                 if (r < 0)
2609                         return r;
2610         }
2611
2612         return 1;
2613 }
2614
2615 ExecRuntime *exec_runtime_ref(ExecRuntime *r) {
2616         assert(r);
2617         assert(r->n_ref > 0);
2618
2619         r->n_ref++;
2620         return r;
2621 }
2622
2623 ExecRuntime *exec_runtime_unref(ExecRuntime *r) {
2624
2625         if (!r)
2626                 return NULL;
2627
2628         assert(r->n_ref > 0);
2629
2630         r->n_ref--;
2631         if (r->n_ref <= 0) {
2632                 free(r->tmp_dir);
2633                 free(r->var_tmp_dir);
2634                 safe_close_pair(r->netns_storage_socket);
2635                 free(r);
2636         }
2637
2638         return NULL;
2639 }
2640
2641 int exec_runtime_serialize(ExecRuntime *rt, Unit *u, FILE *f, FDSet *fds) {
2642         assert(u);
2643         assert(f);
2644         assert(fds);
2645
2646         if (!rt)
2647                 return 0;
2648
2649         if (rt->tmp_dir)
2650                 unit_serialize_item(u, f, "tmp-dir", rt->tmp_dir);
2651
2652         if (rt->var_tmp_dir)
2653                 unit_serialize_item(u, f, "var-tmp-dir", rt->var_tmp_dir);
2654
2655         if (rt->netns_storage_socket[0] >= 0) {
2656                 int copy;
2657
2658                 copy = fdset_put_dup(fds, rt->netns_storage_socket[0]);
2659                 if (copy < 0)
2660                         return copy;
2661
2662                 unit_serialize_item_format(u, f, "netns-socket-0", "%i", copy);
2663         }
2664
2665         if (rt->netns_storage_socket[1] >= 0) {
2666                 int copy;
2667
2668                 copy = fdset_put_dup(fds, rt->netns_storage_socket[1]);
2669                 if (copy < 0)
2670                         return copy;
2671
2672                 unit_serialize_item_format(u, f, "netns-socket-1", "%i", copy);
2673         }
2674
2675         return 0;
2676 }
2677
2678 int exec_runtime_deserialize_item(ExecRuntime **rt, Unit *u, const char *key, const char *value, FDSet *fds) {
2679         int r;
2680
2681         assert(rt);
2682         assert(key);
2683         assert(value);
2684
2685         if (streq(key, "tmp-dir")) {
2686                 char *copy;
2687
2688                 r = exec_runtime_allocate(rt);
2689                 if (r < 0)
2690                         return r;
2691
2692                 copy = strdup(value);
2693                 if (!copy)
2694                         return log_oom();
2695
2696                 free((*rt)->tmp_dir);
2697                 (*rt)->tmp_dir = copy;
2698
2699         } else if (streq(key, "var-tmp-dir")) {
2700                 char *copy;
2701
2702                 r = exec_runtime_allocate(rt);
2703                 if (r < 0)
2704                         return r;
2705
2706                 copy = strdup(value);
2707                 if (!copy)
2708                         return log_oom();
2709
2710                 free((*rt)->var_tmp_dir);
2711                 (*rt)->var_tmp_dir = copy;
2712
2713         } else if (streq(key, "netns-socket-0")) {
2714                 int fd;
2715
2716                 r = exec_runtime_allocate(rt);
2717                 if (r < 0)
2718                         return r;
2719
2720                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd))
2721                         log_debug_unit(u->id, "Failed to parse netns socket value %s", value);
2722                 else {
2723                         safe_close((*rt)->netns_storage_socket[0]);
2724                         (*rt)->netns_storage_socket[0] = fdset_remove(fds, fd);
2725                 }
2726         } else if (streq(key, "netns-socket-1")) {
2727                 int fd;
2728
2729                 r = exec_runtime_allocate(rt);
2730                 if (r < 0)
2731                         return r;
2732
2733                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd))
2734                         log_debug_unit(u->id, "Failed to parse netns socket value %s", value);
2735                 else {
2736                         safe_close((*rt)->netns_storage_socket[1]);
2737                         (*rt)->netns_storage_socket[1] = fdset_remove(fds, fd);
2738                 }
2739         } else
2740                 return 0;
2741
2742         return 1;
2743 }
2744
2745 static void *remove_tmpdir_thread(void *p) {
2746         _cleanup_free_ char *path = p;
2747
2748         rm_rf_dangerous(path, false, true, false);
2749         return NULL;
2750 }
2751
2752 void exec_runtime_destroy(ExecRuntime *rt) {
2753         int r;
2754
2755         if (!rt)
2756                 return;
2757
2758         /* If there are multiple users of this, let's leave the stuff around */
2759         if (rt->n_ref > 1)
2760                 return;
2761
2762         if (rt->tmp_dir) {
2763                 log_debug("Spawning thread to nuke %s", rt->tmp_dir);
2764
2765                 r = asynchronous_job(remove_tmpdir_thread, rt->tmp_dir);
2766                 if (r < 0) {
2767                         log_warning("Failed to nuke %s: %s", rt->tmp_dir, strerror(-r));
2768                         free(rt->tmp_dir);
2769                 }
2770
2771                 rt->tmp_dir = NULL;
2772         }
2773
2774         if (rt->var_tmp_dir) {
2775                 log_debug("Spawning thread to nuke %s", rt->var_tmp_dir);
2776
2777                 r = asynchronous_job(remove_tmpdir_thread, rt->var_tmp_dir);
2778                 if (r < 0) {
2779                         log_warning("Failed to nuke %s: %s", rt->var_tmp_dir, strerror(-r));
2780                         free(rt->var_tmp_dir);
2781                 }
2782
2783                 rt->var_tmp_dir = NULL;
2784         }
2785
2786         safe_close_pair(rt->netns_storage_socket);
2787 }
2788
2789 static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
2790         [EXEC_INPUT_NULL] = "null",
2791         [EXEC_INPUT_TTY] = "tty",
2792         [EXEC_INPUT_TTY_FORCE] = "tty-force",
2793         [EXEC_INPUT_TTY_FAIL] = "tty-fail",
2794         [EXEC_INPUT_SOCKET] = "socket"
2795 };
2796
2797 DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);
2798
2799 static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
2800         [EXEC_OUTPUT_INHERIT] = "inherit",
2801         [EXEC_OUTPUT_NULL] = "null",
2802         [EXEC_OUTPUT_TTY] = "tty",
2803         [EXEC_OUTPUT_SYSLOG] = "syslog",
2804         [EXEC_OUTPUT_SYSLOG_AND_CONSOLE] = "syslog+console",
2805         [EXEC_OUTPUT_KMSG] = "kmsg",
2806         [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
2807         [EXEC_OUTPUT_JOURNAL] = "journal",
2808         [EXEC_OUTPUT_JOURNAL_AND_CONSOLE] = "journal+console",
2809         [EXEC_OUTPUT_SOCKET] = "socket"
2810 };
2811
2812 DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);