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
  87 #ifdef HAVE_SECCOMP
  88 #include "seccomp-util.h"
  89 #endif
  90
  91 #define IDLE_TIMEOUT_USEC (5*USEC_PER_SEC)
  92 #define IDLE_TIMEOUT2_USEC (1*USEC_PER_SEC)
  93
  94 /* This assumes there is a 'tty' group */
  95 #define TTY_MODE 0620
  96
  97 #define SNDBUF_SIZE (8*1024*1024)
  98
  99 static int shift_fds(int fds[], unsigned n_fds) {
 100         int start, restart_from;
 101
 102         if (n_fds <= 0)
 103                 return 0;
 104
 105         /* Modifies the fds array! (sorts it) */
 106
 107         assert(fds);
 108
 109         start = 0;
 110         for (;;) {
 111                 int i;
 112
 113                 restart_from = -1;
 114
 115                 for (i = start; i < (int) n_fds; i++) {
 116                         int nfd;
 117
 118                         /* Already at right index? */
 119                         if (fds[i] == i+3)
 120                                 continue;
 121
 122                         if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)
 123                                 return -errno;
 124
 125                         safe_close(fds[i]);
 126                         fds[i] = nfd;
 127
 128                         /* Hmm, the fd we wanted isn't free? Then
 129                          * let's remember that and try again from here*/
 130                         if (nfd != i+3 && restart_from < 0)
 131                                 restart_from = i;
 132                 }
 133
 134                 if (restart_from < 0)
 135                         break;
 136
 137                 start = restart_from;
 138         }
 139
 140         return 0;
 141 }
 142
 143 static int flags_fds(const int fds[], unsigned n_fds, bool nonblock) {
 144         unsigned i;
 145         int r;
 146
 147         if (n_fds <= 0)
 148                 return 0;
 149
 150         assert(fds);
 151
 152         /* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags */
 153
 154         for (i = 0; i < n_fds; i++) {
 155
 156                 if ((r = fd_nonblock(fds[i], nonblock)) < 0)
 157                         return r;
 158
 159                 /* We unconditionally drop FD_CLOEXEC from the fds,
 160                  * since after all we want to pass these fds to our
 161                  * children */
 162
 163                 if ((r = fd_cloexec(fds[i], false)) < 0)
 164                         return r;
 165         }
 166
 167         return 0;
 168 }
 169
 170 _pure_ static const char *tty_path(const ExecContext *context) {
 171         assert(context);
 172
 173         if (context->tty_path)
 174                 return context->tty_path;
 175
 176         return "/dev/console";
 177 }
 178
 179 static void exec_context_tty_reset(const ExecContext *context) {
 180         assert(context);
 181
 182         if (context->tty_vhangup)
 183                 terminal_vhangup(tty_path(context));
 184
 185         if (context->tty_reset)
 186                 reset_terminal(tty_path(context));
 187
 188         if (context->tty_vt_disallocate && context->tty_path)
 189                 vt_disallocate(context->tty_path);
 190 }
 191
 192 static bool is_terminal_output(ExecOutput o) {
 193         return
 194                 o == EXEC_OUTPUT_TTY ||
 195                 o == EXEC_OUTPUT_SYSLOG_AND_CONSOLE ||
 196                 o == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
 197                 o == EXEC_OUTPUT_JOURNAL_AND_CONSOLE;
 198 }
 199
 200 static int open_null_as(int flags, int nfd) {
 201         int fd, r;
 202
 203         assert(nfd >= 0);
 204
 205         fd = open("/dev/null", flags|O_NOCTTY);
 206         if (fd < 0)
 207                 return -errno;
 208
 209         if (fd != nfd) {
 210                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 211                 safe_close(fd);
 212         } else
 213                 r = nfd;
 214
 215         return r;
 216 }
 217
 218 static int connect_logger_as(const ExecContext *context, ExecOutput output, const char *ident, const char *unit_id, int nfd) {
 219         int fd, r;
 220         union sockaddr_union sa = {
 221                 .un.sun_family = AF_UNIX,
 222                 .un.sun_path = "/run/systemd/journal/stdout",
 223         };
 224
 225         assert(context);
 226         assert(output < _EXEC_OUTPUT_MAX);
 227         assert(ident);
 228         assert(nfd >= 0);
 229
 230         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 231         if (fd < 0)
 232                 return -errno;
 233
 234         r = connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path));
 235         if (r < 0) {
 236                 safe_close(fd);
 237                 return -errno;
 238         }
 239
 240         if (shutdown(fd, SHUT_RD) < 0) {
 241                 safe_close(fd);
 242                 return -errno;
 243         }
 244
 245         fd_inc_sndbuf(fd, SNDBUF_SIZE);
 246
 247         dprintf(fd,
 248                 "%s\n"
 249                 "%s\n"
 250                 "%i\n"
 251                 "%i\n"
 252                 "%i\n"
 253                 "%i\n"
 254                 "%i\n",
 255                 context->syslog_identifier ? context->syslog_identifier : ident,
 256                 unit_id,
 257                 context->syslog_priority,
 258                 !!context->syslog_level_prefix,
 259                 output == EXEC_OUTPUT_SYSLOG || output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
 260                 output == EXEC_OUTPUT_KMSG || output == EXEC_OUTPUT_KMSG_AND_CONSOLE,
 261                 is_terminal_output(output));
 262
 263         if (fd != nfd) {
 264                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 265                 safe_close(fd);
 266         } else
 267                 r = nfd;
 268
 269         return r;
 270 }
 271 static int open_terminal_as(const char *path, mode_t mode, int nfd) {
 272         int fd, r;
 273
 274         assert(path);
 275         assert(nfd >= 0);
 276
 277         if ((fd = open_terminal(path, mode | O_NOCTTY)) < 0)
 278                 return fd;
 279
 280         if (fd != nfd) {
 281                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 282                 safe_close(fd);
 283         } else
 284                 r = nfd;
 285
 286         return r;
 287 }
 288
 289 static bool is_terminal_input(ExecInput i) {
 290         return
 291                 i == EXEC_INPUT_TTY ||
 292                 i == EXEC_INPUT_TTY_FORCE ||
 293                 i == EXEC_INPUT_TTY_FAIL;
 294 }
 295
 296 static int fixup_input(ExecInput std_input, int socket_fd, bool apply_tty_stdin) {
 297
 298         if (is_terminal_input(std_input) && !apply_tty_stdin)
 299                 return EXEC_INPUT_NULL;
 300
 301         if (std_input == EXEC_INPUT_SOCKET && socket_fd < 0)
 302                 return EXEC_INPUT_NULL;
 303
 304         return std_input;
 305 }
 306
 307 static int fixup_output(ExecOutput std_output, int socket_fd) {
 308
 309         if (std_output == EXEC_OUTPUT_SOCKET && socket_fd < 0)
 310                 return EXEC_OUTPUT_INHERIT;
 311
 312         return std_output;
 313 }
 314
 315 static int setup_input(const ExecContext *context, int socket_fd, bool apply_tty_stdin) {
 316         ExecInput i;
 317
 318         assert(context);
 319
 320         i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);
 321
 322         switch (i) {
 323
 324         case EXEC_INPUT_NULL:
 325                 return open_null_as(O_RDONLY, STDIN_FILENO);
 326
 327         case EXEC_INPUT_TTY:
 328         case EXEC_INPUT_TTY_FORCE:
 329         case EXEC_INPUT_TTY_FAIL: {
 330                 int fd, r;
 331
 332                 fd = acquire_terminal(tty_path(context),
 333                                       i == EXEC_INPUT_TTY_FAIL,
 334                                       i == EXEC_INPUT_TTY_FORCE,
 335                                       false,
 336                                       USEC_INFINITY);
 337                 if (fd < 0)
 338                         return fd;
 339
 340                 if (fd != STDIN_FILENO) {
 341                         r = dup2(fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 342                         safe_close(fd);
 343                 } else
 344                         r = STDIN_FILENO;
 345
 346                 return r;
 347         }
 348
 349         case EXEC_INPUT_SOCKET:
 350                 return dup2(socket_fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 351
 352         default:
 353                 assert_not_reached("Unknown input type");
 354         }
 355 }
 356
 357 static int setup_output(const ExecContext *context, int fileno, int socket_fd, const char *ident, const char *unit_id, bool apply_tty_stdin) {
 358         ExecOutput o;
 359         ExecInput i;
 360         int r;
 361
 362         assert(context);
 363         assert(ident);
 364
 365         i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);
 366         o = fixup_output(context->std_output, socket_fd);
 367
 368         if (fileno == STDERR_FILENO) {
 369                 ExecOutput e;
 370                 e = fixup_output(context->std_error, socket_fd);
 371
 372                 /* This expects the input and output are already set up */
 373
 374                 /* Don't change the stderr file descriptor if we inherit all
 375                  * the way and are not on a tty */
 376                 if (e == EXEC_OUTPUT_INHERIT &&
 377                     o == EXEC_OUTPUT_INHERIT &&
 378                     i == EXEC_INPUT_NULL &&
 379                     !is_terminal_input(context->std_input) &&
 380                     getppid () != 1)
 381                         return fileno;
 382
 383                 /* Duplicate from stdout if possible */
 384                 if (e == o || e == EXEC_OUTPUT_INHERIT)
 385                         return dup2(STDOUT_FILENO, fileno) < 0 ? -errno : fileno;
 386
 387                 o = e;
 388
 389         } else if (o == EXEC_OUTPUT_INHERIT) {
 390                 /* If input got downgraded, inherit the original value */
 391                 if (i == EXEC_INPUT_NULL && is_terminal_input(context->std_input))
 392                         return open_terminal_as(tty_path(context), O_WRONLY, fileno);
 393
 394                 /* If the input is connected to anything that's not a /dev/null, inherit that... */
 395                 if (i != EXEC_INPUT_NULL)
 396                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 397
 398                 /* If we are not started from PID 1 we just inherit STDOUT from our parent process. */
 399                 if (getppid() != 1)
 400                         return fileno;
 401
 402                 /* We need to open /dev/null here anew, to get the right access mode. */
 403                 return open_null_as(O_WRONLY, fileno);
 404         }
 405
 406         switch (o) {
 407
 408         case EXEC_OUTPUT_NULL:
 409                 return open_null_as(O_WRONLY, fileno);
 410
 411         case EXEC_OUTPUT_TTY:
 412                 if (is_terminal_input(i))
 413                         return dup2(STDIN_FILENO, fileno) < 0 ? -errno : fileno;
 414
 415                 /* We don't reset the terminal if this is just about output */
 416                 return open_terminal_as(tty_path(context), O_WRONLY, fileno);
 417
 418         case EXEC_OUTPUT_SYSLOG:
 419         case EXEC_OUTPUT_SYSLOG_AND_CONSOLE:
 420         case EXEC_OUTPUT_KMSG:
 421         case EXEC_OUTPUT_KMSG_AND_CONSOLE:
 422         case EXEC_OUTPUT_JOURNAL:
 423         case EXEC_OUTPUT_JOURNAL_AND_CONSOLE:
 424                 r = connect_logger_as(context, o, ident, unit_id, fileno);
 425                 if (r < 0) {
 426                         log_struct_unit(LOG_CRIT, unit_id,
 427                                 "MESSAGE=Failed to connect std%s of %s to the journal socket: %s",
 428                                 fileno == STDOUT_FILENO ? "out" : "err",
 429                                 unit_id, strerror(-r),
 430                                 "ERRNO=%d", -r,
 431                                 NULL);
 432                         r = open_null_as(O_WRONLY, fileno);
 433                 }
 434                 return r;
 435
 436         case EXEC_OUTPUT_SOCKET:
 437                 assert(socket_fd >= 0);
 438                 return dup2(socket_fd, fileno) < 0 ? -errno : fileno;
 439
 440         default:
 441                 assert_not_reached("Unknown error type");
 442         }
 443 }
 444
 445 static int chown_terminal(int fd, uid_t uid) {
 446         struct stat st;
 447
 448         assert(fd >= 0);
 449
 450         /* This might fail. What matters are the results. */
 451         (void) fchown(fd, uid, -1);
 452         (void) fchmod(fd, TTY_MODE);
 453
 454         if (fstat(fd, &st) < 0)
 455                 return -errno;
 456
 457         if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE)
 458                 return -EPERM;
 459
 460         return 0;
 461 }
 462
 463 static int setup_confirm_stdio(int *_saved_stdin,
 464                                int *_saved_stdout) {
 465         int fd = -1, saved_stdin, saved_stdout = -1, r;
 466
 467         assert(_saved_stdin);
 468         assert(_saved_stdout);
 469
 470         saved_stdin = fcntl(STDIN_FILENO, F_DUPFD, 3);
 471         if (saved_stdin < 0)
 472                 return -errno;
 473
 474         saved_stdout = fcntl(STDOUT_FILENO, F_DUPFD, 3);
 475         if (saved_stdout < 0) {
 476                 r = errno;
 477                 goto fail;
 478         }
 479
 480         fd = acquire_terminal(
 481                         "/dev/console",
 482                         false,
 483                         false,
 484                         false,
 485                         DEFAULT_CONFIRM_USEC);
 486         if (fd < 0) {
 487                 r = fd;
 488                 goto fail;
 489         }
 490
 491         r = chown_terminal(fd, getuid());
 492         if (r < 0)
 493                 goto fail;
 494
 495         if (dup2(fd, STDIN_FILENO) < 0) {
 496                 r = -errno;
 497                 goto fail;
 498         }
 499
 500         if (dup2(fd, STDOUT_FILENO) < 0) {
 501                 r = -errno;
 502                 goto fail;
 503         }
 504
 505         if (fd >= 2)
 506                 safe_close(fd);
 507
 508         *_saved_stdin = saved_stdin;
 509         *_saved_stdout = saved_stdout;
 510
 511         return 0;
 512
 513 fail:
 514         safe_close(saved_stdout);
 515         safe_close(saved_stdin);
 516         safe_close(fd);
 517
 518         return r;
 519 }
 520
 521 _printf_(1, 2) static int write_confirm_message(const char *format, ...) {
 522         _cleanup_close_ int fd = -1;
 523         va_list ap;
 524
 525         assert(format);
 526
 527         fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
 528         if (fd < 0)
 529                 return fd;
 530
 531         va_start(ap, format);
 532         vdprintf(fd, format, ap);
 533         va_end(ap);
 534
 535         return 0;
 536 }
 537
 538 static int restore_confirm_stdio(int *saved_stdin,
 539                                  int *saved_stdout) {
 540
 541         int r = 0;
 542
 543         assert(saved_stdin);
 544         assert(saved_stdout);
 545
 546         release_terminal();
 547
 548         if (*saved_stdin >= 0)
 549                 if (dup2(*saved_stdin, STDIN_FILENO) < 0)
 550                         r = -errno;
 551
 552         if (*saved_stdout >= 0)
 553                 if (dup2(*saved_stdout, STDOUT_FILENO) < 0)
 554                         r = -errno;
 555
 556         safe_close(*saved_stdin);
 557         safe_close(*saved_stdout);
 558
 559         return r;
 560 }
 561
 562 static int ask_for_confirmation(char *response, char **argv) {
 563         int saved_stdout = -1, saved_stdin = -1, r;
 564         _cleanup_free_ char *line = NULL;
 565
 566         r = setup_confirm_stdio(&saved_stdin, &saved_stdout);
 567         if (r < 0)
 568                 return r;
 569
 570         line = exec_command_line(argv);
 571         if (!line)
 572                 return -ENOMEM;
 573
 574         r = ask_char(response, "yns", "Execute %s? [Yes, No, Skip] ", line);
 575
 576         restore_confirm_stdio(&saved_stdin, &saved_stdout);
 577
 578         return r;
 579 }
 580
 581 static int enforce_groups(const ExecContext *context, const char *username, gid_t gid) {
 582         bool keep_groups = false;
 583         int r;
 584
 585         assert(context);
 586
 587         /* Lookup and set GID and supplementary group list. Here too
 588          * we avoid NSS lookups for gid=0. */
 589
 590         if (context->group || username) {
 591
 592                 if (context->group) {
 593                         const char *g = context->group;
 594
 595                         if ((r = get_group_creds(&g, &gid)) < 0)
 596                                 return r;
 597                 }
 598
 599                 /* First step, initialize groups from /etc/groups */
 600                 if (username && gid != 0) {
 601                         if (initgroups(username, gid) < 0)
 602                                 return -errno;
 603
 604                         keep_groups = true;
 605                 }
 606
 607                 /* Second step, set our gids */
 608                 if (setresgid(gid, gid, gid) < 0)
 609                         return -errno;
 610         }
 611
 612         if (context->supplementary_groups) {
 613                 int ngroups_max, k;
 614                 gid_t *gids;
 615                 char **i;
 616
 617                 /* Final step, initialize any manually set supplementary groups */
 618                 assert_se((ngroups_max = (int) sysconf(_SC_NGROUPS_MAX)) > 0);
 619
 620                 if (!(gids = new(gid_t, ngroups_max)))
 621                         return -ENOMEM;
 622
 623                 if (keep_groups) {
 624                         if ((k = getgroups(ngroups_max, gids)) < 0) {
 625                                 free(gids);
 626                                 return -errno;
 627                         }
 628                 } else
 629                         k = 0;
 630
 631                 STRV_FOREACH(i, context->supplementary_groups) {
 632                         const char *g;
 633
 634                         if (k >= ngroups_max) {
 635                                 free(gids);
 636                                 return -E2BIG;
 637                         }
 638
 639                         g = *i;
 640                         r = get_group_creds(&g, gids+k);
 641                         if (r < 0) {
 642                                 free(gids);
 643                                 return r;
 644                         }
 645
 646                         k++;
 647                 }
 648
 649                 if (setgroups(k, gids) < 0) {
 650                         free(gids);
 651                         return -errno;
 652                 }
 653
 654                 free(gids);
 655         }
 656
 657         return 0;
 658 }
 659
 660 static int enforce_user(const ExecContext *context, uid_t uid) {
 661         assert(context);
 662
 663         /* Sets (but doesn't lookup) the uid and make sure we keep the
 664          * capabilities while doing so. */
 665
 666         if (context->capabilities) {
 667                 _cleanup_cap_free_ cap_t d = NULL;
 668                 static const cap_value_t bits[] = {
 669                         CAP_SETUID,   /* Necessary so that we can run setresuid() below */
 670                         CAP_SETPCAP   /* Necessary so that we can set PR_SET_SECUREBITS later on */
 671                 };
 672
 673                 /* First step: If we need to keep capabilities but
 674                  * drop privileges we need to make sure we keep our
 675                  * caps, while we drop privileges. */
 676                 if (uid != 0) {
 677                         int sb = context->secure_bits | 1<<SECURE_KEEP_CAPS;
 678
 679                         if (prctl(PR_GET_SECUREBITS) != sb)
 680                                 if (prctl(PR_SET_SECUREBITS, sb) < 0)
 681                                         return -errno;
 682                 }
 683
 684                 /* Second step: set the capabilities. This will reduce
 685                  * the capabilities to the minimum we need. */
 686
 687                 d = cap_dup(context->capabilities);
 688                 if (!d)
 689                         return -errno;
 690
 691                 if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 ||
 692                     cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0)
 693                         return -errno;
 694
 695                 if (cap_set_proc(d) < 0)
 696                         return -errno;
 697         }
 698
 699         /* Third step: actually set the uids */
 700         if (setresuid(uid, uid, uid) < 0)
 701                 return -errno;
 702
 703         /* At this point we should have all necessary capabilities but
 704            are otherwise a normal user. However, the caps might got
 705            corrupted due to the setresuid() so we need clean them up
 706            later. This is done outside of this call. */
 707
 708         return 0;
 709 }
 710
 711 #ifdef HAVE_PAM
 712
 713 static int null_conv(
 714                 int num_msg,
 715                 const struct pam_message **msg,
 716                 struct pam_response **resp,
 717                 void *appdata_ptr) {
 718
 719         /* We don't support conversations */
 720
 721         return PAM_CONV_ERR;
 722 }
 723
 724 static int setup_pam(
 725                 const char *name,
 726                 const char *user,
 727                 uid_t uid,
 728                 const char *tty,
 729                 char ***pam_env,
 730                 int fds[], unsigned n_fds) {
 731
 732         static const struct pam_conv conv = {
 733                 .conv = null_conv,
 734                 .appdata_ptr = NULL
 735         };
 736
 737         pam_handle_t *handle = NULL;
 738         sigset_t ss, old_ss;
 739         int pam_code = PAM_SUCCESS;
 740         int err;
 741         char **e = NULL;
 742         bool close_session = false;
 743         pid_t pam_pid = 0, parent_pid;
 744         int flags = 0;
 745
 746         assert(name);
 747         assert(user);
 748         assert(pam_env);
 749
 750         /* We set up PAM in the parent process, then fork. The child
 751          * will then stay around until killed via PR_GET_PDEATHSIG or
 752          * systemd via the cgroup logic. It will then remove the PAM
 753          * session again. The parent process will exec() the actual
 754          * daemon. We do things this way to ensure that the main PID
 755          * of the daemon is the one we initially fork()ed. */
 756
 757         if (log_get_max_level() < LOG_PRI(LOG_DEBUG))
 758                 flags |= PAM_SILENT;
 759
 760         pam_code = pam_start(name, user, &conv, &handle);
 761         if (pam_code != PAM_SUCCESS) {
 762                 handle = NULL;
 763                 goto fail;
 764         }
 765
 766         if (tty) {
 767                 pam_code = pam_set_item(handle, PAM_TTY, tty);
 768                 if (pam_code != PAM_SUCCESS)
 769                         goto fail;
 770         }
 771
 772         pam_code = pam_acct_mgmt(handle, flags);
 773         if (pam_code != PAM_SUCCESS)
 774                 goto fail;
 775
 776         pam_code = pam_open_session(handle, flags);
 777         if (pam_code != PAM_SUCCESS)
 778                 goto fail;
 779
 780         close_session = true;
 781
 782         e = pam_getenvlist(handle);
 783         if (!e) {
 784                 pam_code = PAM_BUF_ERR;
 785                 goto fail;
 786         }
 787
 788         /* Block SIGTERM, so that we know that it won't get lost in
 789          * the child */
 790         if (sigemptyset(&ss) < 0 ||
 791             sigaddset(&ss, SIGTERM) < 0 ||
 792             sigprocmask(SIG_BLOCK, &ss, &old_ss) < 0)
 793                 goto fail;
 794
 795         parent_pid = getpid();
 796
 797         pam_pid = fork();
 798         if (pam_pid < 0)
 799                 goto fail;
 800
 801         if (pam_pid == 0) {
 802                 int sig;
 803                 int r = EXIT_PAM;
 804
 805                 /* The child's job is to reset the PAM session on
 806                  * termination */
 807
 808                 /* This string must fit in 10 chars (i.e. the length
 809                  * of "/sbin/init"), to look pretty in /bin/ps */
 810                 rename_process("(sd-pam)");
 811
 812                 /* Make sure we don't keep open the passed fds in this
 813                 child. We assume that otherwise only those fds are
 814                 open here that have been opened by PAM. */
 815                 close_many(fds, n_fds);
 816
 817                 /* Drop privileges - we don't need any to pam_close_session
 818                  * and this will make PR_SET_PDEATHSIG work in most cases.
 819                  * If this fails, ignore the error - but expect sd-pam threads
 820                  * to fail to exit normally */
 821                 if (setresuid(uid, uid, uid) < 0)
 822                         log_error("Error: Failed to setresuid() in sd-pam: %s", strerror(-r));
 823
 824                 /* Wait until our parent died. This will only work if
 825                  * the above setresuid() succeeds, otherwise the kernel
 826                  * will not allow unprivileged parents kill their privileged
 827                  * children this way. We rely on the control groups kill logic
 828                  * to do the rest for us. */
 829                 if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
 830                         goto child_finish;
 831
 832                 /* Check if our parent process might already have
 833                  * died? */
 834                 if (getppid() == parent_pid) {
 835                         for (;;) {
 836                                 if (sigwait(&ss, &sig) < 0) {
 837                                         if (errno == EINTR)
 838                                                 continue;
 839
 840                                         goto child_finish;
 841                                 }
 842
 843                                 assert(sig == SIGTERM);
 844                                 break;
 845                         }
 846                 }
 847
 848                 /* If our parent died we'll end the session */
 849                 if (getppid() != parent_pid) {
 850                         pam_code = pam_close_session(handle, flags);
 851                         if (pam_code != PAM_SUCCESS)
 852                                 goto child_finish;
 853                 }
 854
 855                 r = 0;
 856
 857         child_finish:
 858                 pam_end(handle, pam_code | flags);
 859                 _exit(r);
 860         }
 861
 862         /* If the child was forked off successfully it will do all the
 863          * cleanups, so forget about the handle here. */
 864         handle = NULL;
 865
 866         /* Unblock SIGTERM again in the parent */
 867         if (sigprocmask(SIG_SETMASK, &old_ss, NULL) < 0)
 868                 goto fail;
 869
 870         /* We close the log explicitly here, since the PAM modules
 871          * might have opened it, but we don't want this fd around. */
 872         closelog();
 873
 874         *pam_env = e;
 875         e = NULL;
 876
 877         return 0;
 878
 879 fail:
 880         if (pam_code != PAM_SUCCESS) {
 881                 log_error("PAM failed: %s", pam_strerror(handle, pam_code));
 882                 err = -EPERM;  /* PAM errors do not map to errno */
 883         } else {
 884                 log_error("PAM failed: %m");
 885                 err = -errno;
 886         }
 887
 888         if (handle) {
 889                 if (close_session)
 890                         pam_code = pam_close_session(handle, flags);
 891
 892                 pam_end(handle, pam_code | flags);
 893         }
 894
 895         strv_free(e);
 896
 897         closelog();
 898
 899         if (pam_pid > 1) {
 900                 kill(pam_pid, SIGTERM);
 901                 kill(pam_pid, SIGCONT);
 902         }
 903
 904         return err;
 905 }
 906 #endif
 907
 908 static void rename_process_from_path(const char *path) {
 909         char process_name[11];
 910         const char *p;
 911         size_t l;
 912
 913         /* This resulting string must fit in 10 chars (i.e. the length
 914          * of "/sbin/init") to look pretty in /bin/ps */
 915
 916         p = basename(path);
 917         if (isempty(p)) {
 918                 rename_process("(...)");
 919                 return;
 920         }
 921
 922         l = strlen(p);
 923         if (l > 8) {
 924                 /* The end of the process name is usually more
 925                  * interesting, since the first bit might just be
 926                  * "systemd-" */
 927                 p = p + l - 8;
 928                 l = 8;
 929         }
 930
 931         process_name[0] = '(';
 932         memcpy(process_name+1, p, l);
 933         process_name[1+l] = ')';
 934         process_name[1+l+1] = 0;
 935
 936         rename_process(process_name);
 937 }
 938
 939 #ifdef HAVE_SECCOMP
 940
 941 static int apply_seccomp(ExecContext *c) {
 942         uint32_t negative_action, action;
 943         scmp_filter_ctx *seccomp;
 944         Iterator i;
 945         void *id;
 946         int r;
 947
 948         assert(c);
 949
 950         negative_action = c->syscall_errno == 0 ? SCMP_ACT_KILL : SCMP_ACT_ERRNO(c->syscall_errno);
 951
 952         seccomp = seccomp_init(c->syscall_whitelist ? negative_action : SCMP_ACT_ALLOW);
 953         if (!seccomp)
 954                 return -ENOMEM;
 955
 956         if (c->syscall_archs) {
 957
 958                 SET_FOREACH(id, c->syscall_archs, i) {
 959                         r = seccomp_arch_add(seccomp, PTR_TO_UINT32(id) - 1);
 960                         if (r == -EEXIST)
 961                                 continue;
 962                         if (r < 0)
 963                                 goto finish;
 964                 }
 965
 966         } else {
 967                 r = seccomp_add_secondary_archs(seccomp);
 968                 if (r < 0)
 969                         goto finish;
 970         }
 971
 972         action = c->syscall_whitelist ? SCMP_ACT_ALLOW : negative_action;
 973         SET_FOREACH(id, c->syscall_filter, i) {
 974                 r = seccomp_rule_add(seccomp, action, PTR_TO_INT(id) - 1, 0);
 975                 if (r < 0)
 976                         goto finish;
 977         }
 978
 979         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
 980         if (r < 0)
 981                 goto finish;
 982
 983         r = seccomp_load(seccomp);
 984
 985 finish:
 986         seccomp_release(seccomp);
 987         return r;
 988 }
 989
 990 static int apply_address_families(ExecContext *c) {
 991         scmp_filter_ctx *seccomp;
 992         Iterator i;
 993         int r;
 994
 995         assert(c);
 996
 997         seccomp = seccomp_init(SCMP_ACT_ALLOW);
 998         if (!seccomp)
 999                 return -ENOMEM;
1000
1001         r = seccomp_add_secondary_archs(seccomp);
1002         if (r < 0)
1003                 goto finish;
1004
1005         if (c->address_families_whitelist) {
1006                 int af, first = 0, last = 0;
1007                 void *afp;
1008
1009                 /* If this is a whitelist, we first block the address
1010                  * families that are out of range and then everything
1011                  * that is not in the set. First, we find the lowest
1012                  * and highest address family in the set. */
1013
1014                 SET_FOREACH(afp, c->address_families, i) {
1015                         af = PTR_TO_INT(afp);
1016
1017                         if (af <= 0 || af >= af_max())
1018                                 continue;
1019
1020                         if (first == 0 || af < first)
1021                                 first = af;
1022
1023                         if (last == 0 || af > last)
1024                                 last = af;
1025                 }
1026
1027                 assert((first == 0) == (last == 0));
1028
1029                 if (first == 0) {
1030
1031                         /* No entries in the valid range, block everything */
1032                         r = seccomp_rule_add(
1033                                         seccomp,
1034                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1035                                         SCMP_SYS(socket),
1036                                         0);
1037                         if (r < 0)
1038                                 goto finish;
1039
1040                 } else {
1041
1042                         /* Block everything below the first entry */
1043                         r = seccomp_rule_add(
1044                                         seccomp,
1045                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1046                                         SCMP_SYS(socket),
1047                                         1,
1048                                         SCMP_A0(SCMP_CMP_LT, first));
1049                         if (r < 0)
1050                                 goto finish;
1051
1052                         /* Block everything above the last entry */
1053                         r = seccomp_rule_add(
1054                                         seccomp,
1055                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1056                                         SCMP_SYS(socket),
1057                                         1,
1058                                         SCMP_A0(SCMP_CMP_GT, last));
1059                         if (r < 0)
1060                                 goto finish;
1061
1062                         /* Block everything between the first and last
1063                          * entry */
1064                         for (af = 1; af < af_max(); af++) {
1065
1066                                 if (set_contains(c->address_families, INT_TO_PTR(af)))
1067                                         continue;
1068
1069                                 r = seccomp_rule_add(
1070                                                 seccomp,
1071                                                 SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1072                                                 SCMP_SYS(socket),
1073                                                 1,
1074                                                 SCMP_A0(SCMP_CMP_EQ, af));
1075                                 if (r < 0)
1076                                         goto finish;
1077                         }
1078                 }
1079
1080         } else {
1081                 void *af;
1082
1083                 /* If this is a blacklist, then generate one rule for
1084                  * each address family that are then combined in OR
1085                  * checks. */
1086
1087                 SET_FOREACH(af, c->address_families, i) {
1088
1089                         r = seccomp_rule_add(
1090                                         seccomp,
1091                                         SCMP_ACT_ERRNO(EPROTONOSUPPORT),
1092                                         SCMP_SYS(socket),
1093                                         1,
1094                                         SCMP_A0(SCMP_CMP_EQ, PTR_TO_INT(af)));
1095                         if (r < 0)
1096                                 goto finish;
1097                 }
1098         }
1099
1100         r = seccomp_attr_set(seccomp, SCMP_FLTATR_CTL_NNP, 0);
1101         if (r < 0)
1102                 goto finish;
1103
1104         r = seccomp_load(seccomp);
1105
1106 finish:
1107         seccomp_release(seccomp);
1108         return r;
1109 }
1110
1111 #endif
1112
1113 static void do_idle_pipe_dance(int idle_pipe[4]) {
1114         assert(idle_pipe);
1115
1116
1117         safe_close(idle_pipe[1]);
1118         safe_close(idle_pipe[2]);
1119
1120         if (idle_pipe[0] >= 0) {
1121                 int r;
1122
1123                 r = fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT_USEC);
1124
1125                 if (idle_pipe[3] >= 0 && r == 0 /* timeout */) {
1126                         /* Signal systemd that we are bored and want to continue. */
1127                         write(idle_pipe[3], "x", 1);
1128
1129                         /* Wait for systemd to react to the signal above. */
1130                         fd_wait_for_event(idle_pipe[0], POLLHUP, IDLE_TIMEOUT2_USEC);
1131                 }
1132
1133                 safe_close(idle_pipe[0]);
1134
1135         }
1136
1137         safe_close(idle_pipe[3]);
1138 }
1139
1140 static int build_environment(
1141                 ExecContext *c,
1142                 unsigned n_fds,
1143                 usec_t watchdog_usec,
1144                 const char *home,
1145                 const char *username,
1146                 const char *shell,
1147                 char ***ret) {
1148
1149         _cleanup_strv_free_ char **our_env = NULL;
1150         unsigned n_env = 0;
1151         char *x;
1152
1153         assert(c);
1154         assert(ret);
1155
1156         our_env = new0(char*, 10);
1157         if (!our_env)
1158                 return -ENOMEM;
1159
1160         if (n_fds > 0) {
1161                 if (asprintf(&x, "LISTEN_PID="PID_FMT, getpid()) < 0)
1162                         return -ENOMEM;
1163                 our_env[n_env++] = x;
1164
1165                 if (asprintf(&x, "LISTEN_FDS=%u", n_fds) < 0)
1166                         return -ENOMEM;
1167                 our_env[n_env++] = x;
1168         }
1169
1170         if (watchdog_usec > 0) {
1171                 if (asprintf(&x, "WATCHDOG_PID="PID_FMT, getpid()) < 0)
1172                         return -ENOMEM;
1173                 our_env[n_env++] = x;
1174
1175                 if (asprintf(&x, "WATCHDOG_USEC="USEC_FMT, watchdog_usec) < 0)
1176                         return -ENOMEM;
1177                 our_env[n_env++] = x;
1178         }
1179
1180         if (home) {
1181                 x = strappend("HOME=", home);
1182                 if (!x)
1183                         return -ENOMEM;
1184                 our_env[n_env++] = x;
1185         }
1186
1187         if (username) {
1188                 x = strappend("LOGNAME=", username);
1189                 if (!x)
1190                         return -ENOMEM;
1191                 our_env[n_env++] = x;
1192
1193                 x = strappend("USER=", username);
1194                 if (!x)
1195                         return -ENOMEM;
1196                 our_env[n_env++] = x;
1197         }
1198
1199         if (shell) {
1200                 x = strappend("SHELL=", shell);
1201                 if (!x)
1202                         return -ENOMEM;
1203                 our_env[n_env++] = x;
1204         }
1205
1206         if (is_terminal_input(c->std_input) ||
1207             c->std_output == EXEC_OUTPUT_TTY ||
1208             c->std_error == EXEC_OUTPUT_TTY ||
1209             c->tty_path) {
1210
1211                 x = strdup(default_term_for_tty(tty_path(c)));
1212                 if (!x)
1213                         return -ENOMEM;
1214                 our_env[n_env++] = x;
1215         }
1216
1217         our_env[n_env++] = NULL;
1218         assert(n_env <= 10);
1219
1220         *ret = our_env;
1221         our_env = NULL;
1222
1223         return 0;
1224 }
1225
1226 int exec_spawn(ExecCommand *command,
1227                char **argv,
1228                ExecContext *context,
1229                int fds[], unsigned n_fds,
1230                char **environment,
1231                bool apply_permissions,
1232                bool apply_chroot,
1233                bool apply_tty_stdin,
1234                bool confirm_spawn,
1235                CGroupControllerMask cgroup_supported,
1236                const char *cgroup_path,
1237                const char *runtime_prefix,
1238                const char *unit_id,
1239                usec_t watchdog_usec,
1240                int idle_pipe[4],
1241                ExecRuntime *runtime,
1242                pid_t *ret) {
1243
1244         _cleanup_strv_free_ char **files_env = NULL;
1245         int socket_fd;
1246         char *line;
1247         pid_t pid;
1248         int r;
1249
1250         assert(command);
1251         assert(context);
1252         assert(ret);
1253         assert(fds || n_fds <= 0);
1254
1255         if (context->std_input == EXEC_INPUT_SOCKET ||
1256             context->std_output == EXEC_OUTPUT_SOCKET ||
1257             context->std_error == EXEC_OUTPUT_SOCKET) {
1258
1259                 if (n_fds != 1)
1260                         return -EINVAL;
1261
1262                 socket_fd = fds[0];
1263
1264                 fds = NULL;
1265                 n_fds = 0;
1266         } else
1267                 socket_fd = -1;
1268
1269         r = exec_context_load_environment(context, &files_env);
1270         if (r < 0) {
1271                 log_struct_unit(LOG_ERR,
1272                            unit_id,
1273                            "MESSAGE=Failed to load environment files: %s", strerror(-r),
1274                            "ERRNO=%d", -r,
1275                            NULL);
1276                 return r;
1277         }
1278
1279         if (!argv)
1280                 argv = command->argv;
1281
1282         line = exec_command_line(argv);
1283         if (!line)
1284                 return log_oom();
1285
1286         log_struct_unit(LOG_DEBUG,
1287                         unit_id,
1288                         "EXECUTABLE=%s", command->path,
1289                         "MESSAGE=About to execute: %s", line,
1290                         NULL);
1291         free(line);
1292
1293         pid = fork();
1294         if (pid < 0)
1295                 return -errno;
1296
1297         if (pid == 0) {
1298                 _cleanup_strv_free_ char **our_env = NULL, **pam_env = NULL, **final_env = NULL, **final_argv = NULL;
1299                 const char *username = NULL, *home = NULL, *shell = NULL;
1300                 unsigned n_dont_close = 0;
1301                 int dont_close[n_fds + 3];
1302                 uid_t uid = (uid_t) -1;
1303                 gid_t gid = (gid_t) -1;
1304                 sigset_t ss;
1305                 int i, err;
1306
1307                 /* child */
1308
1309                 rename_process_from_path(command->path);
1310
1311                 /* We reset exactly these signals, since they are the
1312                  * only ones we set to SIG_IGN in the main daemon. All
1313                  * others we leave untouched because we set them to
1314                  * SIG_DFL or a valid handler initially, both of which
1315                  * will be demoted to SIG_DFL. */
1316                 default_signals(SIGNALS_CRASH_HANDLER,
1317                                 SIGNALS_IGNORE, -1);
1318
1319                 if (context->ignore_sigpipe)
1320                         ignore_signals(SIGPIPE, -1);
1321
1322                 assert_se(sigemptyset(&ss) == 0);
1323                 if (sigprocmask(SIG_SETMASK, &ss, NULL) < 0) {
1324                         err = -errno;
1325                         r = EXIT_SIGNAL_MASK;
1326                         goto fail_child;
1327                 }
1328
1329                 if (idle_pipe)
1330                         do_idle_pipe_dance(idle_pipe);
1331
1332                 /* Close sockets very early to make sure we don't
1333                  * block init reexecution because it cannot bind its
1334                  * sockets */
1335                 log_forget_fds();
1336
1337                 if (socket_fd >= 0)
1338                         dont_close[n_dont_close++] = socket_fd;
1339                 if (n_fds > 0) {
1340                         memcpy(dont_close + n_dont_close, fds, sizeof(int) * n_fds);
1341                         n_dont_close += n_fds;
1342                 }
1343                 if (runtime) {
1344                         if (runtime->netns_storage_socket[0] >= 0)
1345                                 dont_close[n_dont_close++] = runtime->netns_storage_socket[0];
1346                         if (runtime->netns_storage_socket[1] >= 0)
1347                                 dont_close[n_dont_close++] = runtime->netns_storage_socket[1];
1348                 }
1349
1350                 err = close_all_fds(dont_close, n_dont_close);
1351                 if (err < 0) {
1352                         r = EXIT_FDS;
1353                         goto fail_child;
1354                 }
1355
1356                 if (!context->same_pgrp)
1357                         if (setsid() < 0) {
1358                                 err = -errno;
1359                                 r = EXIT_SETSID;
1360                                 goto fail_child;
1361                         }
1362
1363                 exec_context_tty_reset(context);
1364
1365                 if (confirm_spawn) {
1366                         char response;
1367
1368                         err = ask_for_confirmation(&response, argv);
1369                         if (err == -ETIMEDOUT)
1370                                 write_confirm_message("Confirmation question timed out, assuming positive response.\n");
1371                         else if (err < 0)
1372                                 write_confirm_message("Couldn't ask confirmation question, assuming positive response: %s\n", strerror(-err));
1373                         else if (response == 's') {
1374                                 write_confirm_message("Skipping execution.\n");
1375                                 err = -ECANCELED;
1376                                 r = EXIT_CONFIRM;
1377                                 goto fail_child;
1378                         } else if (response == 'n') {
1379                                 write_confirm_message("Failing execution.\n");
1380                                 err = r = 0;
1381                                 goto fail_child;
1382                         }
1383                 }
1384
1385                 /* If a socket is connected to STDIN/STDOUT/STDERR, we
1386                  * must sure to drop O_NONBLOCK */
1387                 if (socket_fd >= 0)
1388                         fd_nonblock(socket_fd, false);
1389
1390                 err = setup_input(context, socket_fd, apply_tty_stdin);
1391                 if (err < 0) {
1392                         r = EXIT_STDIN;
1393                         goto fail_child;
1394                 }
1395
1396                 err = setup_output(context, STDOUT_FILENO, socket_fd, basename(command->path), unit_id, apply_tty_stdin);
1397                 if (err < 0) {
1398                         r = EXIT_STDOUT;
1399                         goto fail_child;
1400                 }
1401
1402                 err = setup_output(context, STDERR_FILENO, socket_fd, basename(command->path), unit_id, apply_tty_stdin);
1403                 if (err < 0) {
1404                         r = EXIT_STDERR;
1405                         goto fail_child;
1406                 }
1407
1408                 if (cgroup_path) {
1409                         err = cg_attach_everywhere(cgroup_supported, cgroup_path, 0);
1410                         if (err < 0) {
1411                                 r = EXIT_CGROUP;
1412                                 goto fail_child;
1413                         }
1414                 }
1415
1416                 if (context->oom_score_adjust_set) {
1417                         char t[16];
1418
1419                         snprintf(t, sizeof(t), "%i", context->oom_score_adjust);
1420                         char_array_0(t);
1421
1422                         if (write_string_file("/proc/self/oom_score_adj", t) < 0) {
1423                                 err = -errno;
1424                                 r = EXIT_OOM_ADJUST;
1425                                 goto fail_child;
1426                         }
1427                 }
1428
1429                 if (context->nice_set)
1430                         if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
1431                                 err = -errno;
1432                                 r = EXIT_NICE;
1433                                 goto fail_child;
1434                         }
1435
1436                 if (context->cpu_sched_set) {
1437                         struct sched_param param = {
1438                                 .sched_priority = context->cpu_sched_priority,
1439                         };
1440
1441                         r = sched_setscheduler(0,
1442                                                context->cpu_sched_policy |
1443                                                (context->cpu_sched_reset_on_fork ?
1444                                                 SCHED_RESET_ON_FORK : 0),
1445                                                &param);
1446                         if (r < 0) {
1447                                 err = -errno;
1448                                 r = EXIT_SETSCHEDULER;
1449                                 goto fail_child;
1450                         }
1451                 }
1452
1453                 if (context->cpuset)
1454                         if (sched_setaffinity(0, CPU_ALLOC_SIZE(context->cpuset_ncpus), context->cpuset) < 0) {
1455                                 err = -errno;
1456                                 r = EXIT_CPUAFFINITY;
1457                                 goto fail_child;
1458                         }
1459
1460                 if (context->ioprio_set)
1461                         if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {
1462                                 err = -errno;
1463                                 r = EXIT_IOPRIO;
1464                                 goto fail_child;
1465                         }
1466
1467                 if (context->timer_slack_nsec != NSEC_INFINITY)
1468                         if (prctl(PR_SET_TIMERSLACK, context->timer_slack_nsec) < 0) {
1469                                 err = -errno;
1470                                 r = EXIT_TIMERSLACK;
1471                                 goto fail_child;
1472                         }
1473
1474                 if (context->personality != 0xffffffffUL)
1475                         if (personality(context->personality) < 0) {
1476                                 err = -errno;
1477                                 r = EXIT_PERSONALITY;
1478                                 goto fail_child;
1479                         }
1480
1481                 if (context->utmp_id)
1482                         utmp_put_init_process(context->utmp_id, getpid(), getsid(0), context->tty_path);
1483
1484                 if (context->user) {
1485                         username = context->user;
1486                         err = get_user_creds(&username, &uid, &gid, &home, &shell);
1487                         if (err < 0) {
1488                                 r = EXIT_USER;
1489                                 goto fail_child;
1490                         }
1491
1492                         if (is_terminal_input(context->std_input)) {
1493                                 err = chown_terminal(STDIN_FILENO, uid);
1494                                 if (err < 0) {
1495                                         r = EXIT_STDIN;
1496                                         goto fail_child;
1497                                 }
1498                         }
1499                 }
1500
1501 #ifdef HAVE_PAM
1502                 if (cgroup_path && context->user && context->pam_name) {
1503                         err = cg_set_task_access(SYSTEMD_CGROUP_CONTROLLER, cgroup_path, 0644, uid, gid);
1504                         if (err < 0) {
1505                                 r = EXIT_CGROUP;
1506                                 goto fail_child;
1507                         }
1508
1509
1510                         err = cg_set_group_access(SYSTEMD_CGROUP_CONTROLLER, cgroup_path, 0755, uid, gid);
1511                         if (err < 0) {
1512                                 r = EXIT_CGROUP;
1513                                 goto fail_child;
1514                         }
1515                 }
1516 #endif
1517
1518                 if (!strv_isempty(context->runtime_directory) && runtime_prefix) {
1519                         char **rt;
1520
1521                         STRV_FOREACH(rt, context->runtime_directory) {
1522                                 _cleanup_free_ char *p;
1523
1524                                 p = strjoin(runtime_prefix, "/", *rt, NULL);
1525                                 if (!p) {
1526                                         r = EXIT_RUNTIME_DIRECTORY;
1527                                         err = -ENOMEM;
1528                                         goto fail_child;
1529                                 }
1530
1531                                 err = mkdir_safe(p, context->runtime_directory_mode, uid, gid);
1532                                 if (err < 0) {
1533                                         r = EXIT_RUNTIME_DIRECTORY;
1534                                         goto fail_child;
1535                                 }
1536                         }
1537                 }
1538
1539                 if (apply_permissions) {
1540                         err = enforce_groups(context, username, gid);
1541                         if (err < 0) {
1542                                 r = EXIT_GROUP;
1543                                 goto fail_child;
1544                         }
1545                 }
1546
1547                 umask(context->umask);
1548
1549 #ifdef HAVE_PAM
1550                 if (apply_permissions && context->pam_name && username) {
1551                         err = setup_pam(context->pam_name, username, uid, context->tty_path, &pam_env, fds, n_fds);
1552                         if (err < 0) {
1553                                 r = EXIT_PAM;
1554                                 goto fail_child;
1555                         }
1556                 }
1557 #endif
1558                 if (context->private_network && runtime && runtime->netns_storage_socket[0] >= 0) {
1559                         err = setup_netns(runtime->netns_storage_socket);
1560                         if (err < 0) {
1561                                 r = EXIT_NETWORK;
1562                                 goto fail_child;
1563                         }
1564                 }
1565
1566                 if (!strv_isempty(context->read_write_dirs) ||
1567                     !strv_isempty(context->read_only_dirs) ||
1568                     !strv_isempty(context->inaccessible_dirs) ||
1569                     context->mount_flags != 0 ||
1570                     (context->private_tmp && runtime && (runtime->tmp_dir || runtime->var_tmp_dir)) ||
1571                     context->private_devices ||
1572                     context->protect_system != PROTECT_SYSTEM_NO ||
1573                     context->protect_home != PROTECT_HOME_NO) {
1574
1575                         char *tmp = NULL, *var = NULL;
1576
1577                         /* The runtime struct only contains the parent
1578                          * of the private /tmp, which is
1579                          * non-accessible to world users. Inside of it
1580                          * there's a /tmp that is sticky, and that's
1581                          * the one we want to use here. */
1582
1583                         if (context->private_tmp && runtime) {
1584                                 if (runtime->tmp_dir)
1585                                         tmp = strappenda(runtime->tmp_dir, "/tmp");
1586                                 if (runtime->var_tmp_dir)
1587                                         var = strappenda(runtime->var_tmp_dir, "/tmp");
1588                         }
1589
1590                         err = setup_namespace(
1591                                         context->read_write_dirs,
1592                                         context->read_only_dirs,
1593                                         context->inaccessible_dirs,
1594                                         tmp,
1595                                         var,
1596                                         context->private_devices,
1597                                         context->protect_home,
1598                                         context->protect_system,
1599                                         context->mount_flags);
1600                         if (err < 0) {
1601                                 r = EXIT_NAMESPACE;
1602                                 goto fail_child;
1603                         }
1604                 }
1605
1606                 if (apply_chroot) {
1607                         if (context->root_directory)
1608                                 if (chroot(context->root_directory) < 0) {
1609                                         err = -errno;
1610                                         r = EXIT_CHROOT;
1611                                         goto fail_child;
1612                                 }
1613
1614                         if (chdir(context->working_directory ? context->working_directory : "/") < 0) {
1615                                 err = -errno;
1616                                 r = EXIT_CHDIR;
1617                                 goto fail_child;
1618                         }
1619                 } else {
1620                         _cleanup_free_ char *d = NULL;
1621
1622                         if (asprintf(&d, "%s/%s",
1623                                      context->root_directory ? context->root_directory : "",
1624                                      context->working_directory ? context->working_directory : "") < 0) {
1625                                 err = -ENOMEM;
1626                                 r = EXIT_MEMORY;
1627                                 goto fail_child;
1628                         }
1629
1630                         if (chdir(d) < 0) {
1631                                 err = -errno;
1632                                 r = EXIT_CHDIR;
1633                                 goto fail_child;
1634                         }
1635                 }
1636
1637                 /* We repeat the fd closing here, to make sure that
1638                  * nothing is leaked from the PAM modules */
1639                 err = close_all_fds(fds, n_fds);
1640                 if (err >= 0)
1641                         err = shift_fds(fds, n_fds);
1642                 if (err >= 0)
1643                         err = flags_fds(fds, n_fds, context->non_blocking);
1644                 if (err < 0) {
1645                         r = EXIT_FDS;
1646                         goto fail_child;
1647                 }
1648
1649                 if (apply_permissions) {
1650
1651                         for (i = 0; i < _RLIMIT_MAX; i++) {
1652                                 if (!context->rlimit[i])
1653                                         continue;
1654
1655                                 if (setrlimit_closest(i, context->rlimit[i]) < 0) {
1656                                         err = -errno;
1657                                         r = EXIT_LIMITS;
1658                                         goto fail_child;
1659                                 }
1660                         }
1661
1662                         if (context->capability_bounding_set_drop) {
1663                                 err = capability_bounding_set_drop(context->capability_bounding_set_drop, false);
1664                                 if (err < 0) {
1665                                         r = EXIT_CAPABILITIES;
1666                                         goto fail_child;
1667                                 }
1668                         }
1669
1670                         if (context->user) {
1671                                 err = enforce_user(context, uid);
1672                                 if (err < 0) {
1673                                         r = EXIT_USER;
1674                                         goto fail_child;
1675                                 }
1676                         }
1677
1678                         /* PR_GET_SECUREBITS is not privileged, while
1679                          * PR_SET_SECUREBITS is. So to suppress
1680                          * potential EPERMs we'll try not to call
1681                          * PR_SET_SECUREBITS unless necessary. */
1682                         if (prctl(PR_GET_SECUREBITS) != context->secure_bits)
1683                                 if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) {
1684                                         err = -errno;
1685                                         r = EXIT_SECUREBITS;
1686                                         goto fail_child;
1687                                 }
1688
1689                         if (context->capabilities)
1690                                 if (cap_set_proc(context->capabilities) < 0) {
1691                                         err = -errno;
1692                                         r = EXIT_CAPABILITIES;
1693                                         goto fail_child;
1694                                 }
1695
1696                         if (context->no_new_privileges)
1697                                 if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
1698                                         err = -errno;
1699                                         r = EXIT_NO_NEW_PRIVILEGES;
1700                                         goto fail_child;
1701                                 }
1702
1703 #ifdef HAVE_SECCOMP
1704                         if (context->address_families_whitelist ||
1705                             !set_isempty(context->address_families)) {
1706                                 err = apply_address_families(context);
1707                                 if (err < 0) {
1708                                         r = EXIT_ADDRESS_FAMILIES;
1709                                         goto fail_child;
1710                                 }
1711                         }
1712
1713                         if (context->syscall_whitelist ||
1714                             !set_isempty(context->syscall_filter) ||
1715                             !set_isempty(context->syscall_archs)) {
1716                                 err = apply_seccomp(context);
1717                                 if (err < 0) {
1718                                         r = EXIT_SECCOMP;
1719                                         goto fail_child;
1720                                 }
1721                         }
1722 #endif
1723
1724 #ifdef HAVE_SELINUX
1725                         if (context->selinux_context && use_selinux()) {
1726                                 err = setexeccon(context->selinux_context);
1727                                 if (err < 0 && !context->selinux_context_ignore) {
1728                                         r = EXIT_SELINUX_CONTEXT;
1729                                         goto fail_child;
1730                                 }
1731                         }
1732 #endif
1733
1734 #ifdef HAVE_APPARMOR
1735                         if (context->apparmor_profile && use_apparmor()) {
1736                                 err = aa_change_onexec(context->apparmor_profile);
1737                                 if (err < 0 && !context->apparmor_profile_ignore) {
1738                                         r = EXIT_APPARMOR_PROFILE;
1739                                         goto fail_child;
1740                                 }
1741                         }
1742 #endif
1743                 }
1744
1745                 err = build_environment(context, n_fds, watchdog_usec, home, username, shell, &our_env);
1746                 if (r < 0) {
1747                         r = EXIT_MEMORY;
1748                         goto fail_child;
1749                 }
1750
1751                 final_env = strv_env_merge(5,
1752                                            environment,
1753                                            our_env,
1754                                            context->environment,
1755                                            files_env,
1756                                            pam_env,
1757                                            NULL);
1758                 if (!final_env) {
1759                         err = -ENOMEM;
1760                         r = EXIT_MEMORY;
1761                         goto fail_child;
1762                 }
1763
1764                 final_argv = replace_env_argv(argv, final_env);
1765                 if (!final_argv) {
1766                         err = -ENOMEM;
1767                         r = EXIT_MEMORY;
1768                         goto fail_child;
1769                 }
1770
1771                 final_env = strv_env_clean(final_env);
1772
1773                 if (_unlikely_(log_get_max_level() >= LOG_PRI(LOG_DEBUG))) {
1774                         line = exec_command_line(final_argv);
1775                         if (line) {
1776                                 log_open();
1777                                 log_struct_unit(LOG_DEBUG,
1778                                                 unit_id,
1779                                                 "EXECUTABLE=%s", command->path,
1780                                                 "MESSAGE=Executing: %s", line,
1781                                                 NULL);
1782                                 log_close();
1783                                 free(line);
1784                                 line = NULL;
1785                         }
1786                 }
1787                 execve(command->path, final_argv, final_env);
1788                 err = -errno;
1789                 r = EXIT_EXEC;
1790
1791         fail_child:
1792                 if (r != 0) {
1793                         log_open();
1794                         log_struct(LOG_ERR, MESSAGE_ID(SD_MESSAGE_SPAWN_FAILED),
1795                                    "EXECUTABLE=%s", command->path,
1796                                    "MESSAGE=Failed at step %s spawning %s: %s",
1797                                           exit_status_to_string(r, EXIT_STATUS_SYSTEMD),
1798                                           command->path, strerror(-err),
1799                                    "ERRNO=%d", -err,
1800                                    NULL);
1801                         log_close();
1802                 }
1803
1804                 _exit(r);
1805         }
1806
1807         log_struct_unit(LOG_DEBUG,
1808                         unit_id,
1809                         "MESSAGE=Forked %s as "PID_FMT,
1810                         command->path, pid,
1811                         NULL);
1812
1813         /* We add the new process to the cgroup both in the child (so
1814          * that we can be sure that no user code is ever executed
1815          * outside of the cgroup) and in the parent (so that we can be
1816          * sure that when we kill the cgroup the process will be
1817          * killed too). */
1818         if (cgroup_path)
1819                 cg_attach(SYSTEMD_CGROUP_CONTROLLER, cgroup_path, pid);
1820
1821         exec_status_start(&command->exec_status, pid);
1822
1823         *ret = pid;
1824         return 0;
1825 }
1826
1827 void exec_context_init(ExecContext *c) {
1828         assert(c);
1829
1830         c->umask = 0022;
1831         c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);
1832         c->cpu_sched_policy = SCHED_OTHER;
1833         c->syslog_priority = LOG_DAEMON|LOG_INFO;
1834         c->syslog_level_prefix = true;
1835         c->ignore_sigpipe = true;
1836         c->timer_slack_nsec = NSEC_INFINITY;
1837         c->personality = 0xffffffffUL;
1838         c->runtime_directory_mode = 0755;
1839 }
1840
1841 void exec_context_done(ExecContext *c) {
1842         unsigned l;
1843
1844         assert(c);
1845
1846         strv_free(c->environment);
1847         c->environment = NULL;
1848
1849         strv_free(c->environment_files);
1850         c->environment_files = NULL;
1851
1852         for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {
1853                 free(c->rlimit[l]);
1854                 c->rlimit[l] = NULL;
1855         }
1856
1857         free(c->working_directory);
1858         c->working_directory = NULL;
1859         free(c->root_directory);
1860         c->root_directory = NULL;
1861
1862         free(c->tty_path);
1863         c->tty_path = NULL;
1864
1865         free(c->syslog_identifier);
1866         c->syslog_identifier = NULL;
1867
1868         free(c->user);
1869         c->user = NULL;
1870
1871         free(c->group);
1872         c->group = NULL;
1873
1874         strv_free(c->supplementary_groups);
1875         c->supplementary_groups = NULL;
1876
1877         free(c->pam_name);
1878         c->pam_name = NULL;
1879
1880         if (c->capabilities) {
1881                 cap_free(c->capabilities);
1882                 c->capabilities = NULL;
1883         }
1884
1885         strv_free(c->read_only_dirs);
1886         c->read_only_dirs = NULL;
1887
1888         strv_free(c->read_write_dirs);
1889         c->read_write_dirs = NULL;
1890
1891         strv_free(c->inaccessible_dirs);
1892         c->inaccessible_dirs = NULL;
1893
1894         if (c->cpuset)
1895                 CPU_FREE(c->cpuset);
1896
1897         free(c->utmp_id);
1898         c->utmp_id = NULL;
1899
1900         free(c->selinux_context);
1901         c->selinux_context = NULL;
1902
1903         free(c->apparmor_profile);
1904         c->apparmor_profile = NULL;
1905
1906         set_free(c->syscall_filter);
1907         c->syscall_filter = NULL;
1908
1909         set_free(c->syscall_archs);
1910         c->syscall_archs = NULL;
1911
1912         set_free(c->address_families);
1913         c->address_families = NULL;
1914
1915         strv_free(c->runtime_directory);
1916         c->runtime_directory = NULL;
1917 }
1918
1919 int exec_context_destroy_runtime_directory(ExecContext *c, const char *runtime_prefix) {
1920         char **i;
1921
1922         assert(c);
1923
1924         if (!runtime_prefix)
1925                 return 0;
1926
1927         STRV_FOREACH(i, c->runtime_directory) {
1928                 _cleanup_free_ char *p;
1929
1930                 p = strjoin(runtime_prefix, "/", *i, NULL);
1931                 if (!p)
1932                         return -ENOMEM;
1933
1934                 /* We execute this synchronously, since we need to be
1935                  * sure this is gone when we start the service
1936                  * next. */
1937                 rm_rf_dangerous(p, false, true, false);
1938         }
1939
1940         return 0;
1941 }
1942
1943 void exec_command_done(ExecCommand *c) {
1944         assert(c);
1945
1946         free(c->path);
1947         c->path = NULL;
1948
1949         strv_free(c->argv);
1950         c->argv = NULL;
1951 }
1952
1953 void exec_command_done_array(ExecCommand *c, unsigned n) {
1954         unsigned i;
1955
1956         for (i = 0; i < n; i++)
1957                 exec_command_done(c+i);
1958 }
1959
1960 void exec_command_free_list(ExecCommand *c) {
1961         ExecCommand *i;
1962
1963         while ((i = c)) {
1964                 LIST_REMOVE(command, c, i);
1965                 exec_command_done(i);
1966                 free(i);
1967         }
1968 }
1969
1970 void exec_command_free_array(ExecCommand **c, unsigned n) {
1971         unsigned i;
1972
1973         for (i = 0; i < n; i++) {
1974                 exec_command_free_list(c[i]);
1975                 c[i] = NULL;
1976         }
1977 }
1978
1979 int exec_context_load_environment(const ExecContext *c, char ***l) {
1980         char **i, **r = NULL;
1981
1982         assert(c);
1983         assert(l);
1984
1985         STRV_FOREACH(i, c->environment_files) {
1986                 char *fn;
1987                 int k;
1988                 bool ignore = false;
1989                 char **p;
1990                 _cleanup_globfree_ glob_t pglob = {};
1991                 int count, n;
1992
1993                 fn = *i;
1994
1995                 if (fn[0] == '-') {
1996                         ignore = true;
1997                         fn ++;
1998                 }
1999
2000                 if (!path_is_absolute(fn)) {
2001                         if (ignore)
2002                                 continue;
2003
2004                         strv_free(r);
2005                         return -EINVAL;
2006                 }
2007
2008                 /* Filename supports globbing, take all matching files */
2009                 errno = 0;
2010                 if (glob(fn, 0, NULL, &pglob) != 0) {
2011                         if (ignore)
2012                                 continue;
2013
2014                         strv_free(r);
2015                         return errno ? -errno : -EINVAL;
2016                 }
2017                 count = pglob.gl_pathc;
2018                 if (count == 0) {
2019                         if (ignore)
2020                                 continue;
2021
2022                         strv_free(r);
2023                         return -EINVAL;
2024                 }
2025                 for (n = 0; n < count; n++) {
2026                         k = load_env_file(NULL, pglob.gl_pathv[n], NULL, &p);
2027                         if (k < 0) {
2028                                 if (ignore)
2029                                         continue;
2030
2031                                 strv_free(r);
2032                                 return k;
2033                         }
2034                         /* Log invalid environment variables with filename */
2035                         if (p)
2036                                 p = strv_env_clean_log(p, pglob.gl_pathv[n]);
2037
2038                         if (r == NULL)
2039                                 r = p;
2040                         else {
2041                                 char **m;
2042
2043                                 m = strv_env_merge(2, r, p);
2044                                 strv_free(r);
2045                                 strv_free(p);
2046                                 if (!m)
2047                                         return -ENOMEM;
2048
2049                                 r = m;
2050                         }
2051                 }
2052         }
2053
2054         *l = r;
2055
2056         return 0;
2057 }
2058
2059 static bool tty_may_match_dev_console(const char *tty) {
2060         _cleanup_free_ char *active = NULL;
2061        char *console;
2062
2063         if (startswith(tty, "/dev/"))
2064                 tty += 5;
2065
2066         /* trivial identity? */
2067         if (streq(tty, "console"))
2068                 return true;
2069
2070         console = resolve_dev_console(&active);
2071         /* if we could not resolve, assume it may */
2072         if (!console)
2073                 return true;
2074
2075         /* "tty0" means the active VC, so it may be the same sometimes */
2076         return streq(console, tty) || (streq(console, "tty0") && tty_is_vc(tty));
2077 }
2078
2079 bool exec_context_may_touch_console(ExecContext *ec) {
2080         return (ec->tty_reset || ec->tty_vhangup || ec->tty_vt_disallocate ||
2081                 is_terminal_input(ec->std_input) ||
2082                 is_terminal_output(ec->std_output) ||
2083                 is_terminal_output(ec->std_error)) &&
2084                tty_may_match_dev_console(tty_path(ec));
2085 }
2086
2087 static void strv_fprintf(FILE *f, char **l) {
2088         char **g;
2089
2090         assert(f);
2091
2092         STRV_FOREACH(g, l)
2093                 fprintf(f, " %s", *g);
2094 }
2095
2096 void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
2097         char **e;
2098         unsigned i;
2099
2100         assert(c);
2101         assert(f);
2102
2103         prefix = strempty(prefix);
2104
2105         fprintf(f,
2106                 "%sUMask: %04o\n"
2107                 "%sWorkingDirectory: %s\n"
2108                 "%sRootDirectory: %s\n"
2109                 "%sNonBlocking: %s\n"
2110                 "%sPrivateTmp: %s\n"
2111                 "%sPrivateNetwork: %s\n"
2112                 "%sPrivateDevices: %s\n"
2113                 "%sProtectHome: %s\n"
2114                 "%sProtectSystem: %s\n"
2115                 "%sIgnoreSIGPIPE: %s\n",
2116                 prefix, c->umask,
2117                 prefix, c->working_directory ? c->working_directory : "/",
2118                 prefix, c->root_directory ? c->root_directory : "/",
2119                 prefix, yes_no(c->non_blocking),
2120                 prefix, yes_no(c->private_tmp),
2121                 prefix, yes_no(c->private_network),
2122                 prefix, yes_no(c->private_devices),
2123                 prefix, protect_home_to_string(c->protect_home),
2124                 prefix, protect_system_to_string(c->protect_system),
2125                 prefix, yes_no(c->ignore_sigpipe));
2126
2127         STRV_FOREACH(e, c->environment)
2128                 fprintf(f, "%sEnvironment: %s\n", prefix, *e);
2129
2130         STRV_FOREACH(e, c->environment_files)
2131                 fprintf(f, "%sEnvironmentFile: %s\n", prefix, *e);
2132
2133         if (c->nice_set)
2134                 fprintf(f,
2135                         "%sNice: %i\n",
2136                         prefix, c->nice);
2137
2138         if (c->oom_score_adjust_set)
2139                 fprintf(f,
2140                         "%sOOMScoreAdjust: %i\n",
2141                         prefix, c->oom_score_adjust);
2142
2143         for (i = 0; i < RLIM_NLIMITS; i++)
2144                 if (c->rlimit[i])
2145                         fprintf(f, "%s%s: "RLIM_FMT"\n",
2146                                 prefix, rlimit_to_string(i), c->rlimit[i]->rlim_max);
2147
2148         if (c->ioprio_set) {
2149                 _cleanup_free_ char *class_str = NULL;
2150
2151                 ioprio_class_to_string_alloc(IOPRIO_PRIO_CLASS(c->ioprio), &class_str);
2152                 fprintf(f,
2153                         "%sIOSchedulingClass: %s\n"
2154                         "%sIOPriority: %i\n",
2155                         prefix, strna(class_str),
2156                         prefix, (int) IOPRIO_PRIO_DATA(c->ioprio));
2157         }
2158
2159         if (c->cpu_sched_set) {
2160                 _cleanup_free_ char *policy_str = NULL;
2161
2162                 sched_policy_to_string_alloc(c->cpu_sched_policy, &policy_str);
2163                 fprintf(f,
2164                         "%sCPUSchedulingPolicy: %s\n"
2165                         "%sCPUSchedulingPriority: %i\n"
2166                         "%sCPUSchedulingResetOnFork: %s\n",
2167                         prefix, strna(policy_str),
2168                         prefix, c->cpu_sched_priority,
2169                         prefix, yes_no(c->cpu_sched_reset_on_fork));
2170         }
2171
2172         if (c->cpuset) {
2173                 fprintf(f, "%sCPUAffinity:", prefix);
2174                 for (i = 0; i < c->cpuset_ncpus; i++)
2175                         if (CPU_ISSET_S(i, CPU_ALLOC_SIZE(c->cpuset_ncpus), c->cpuset))
2176                                 fprintf(f, " %u", i);
2177                 fputs("\n", f);
2178         }
2179
2180         if (c->timer_slack_nsec != NSEC_INFINITY)
2181                 fprintf(f, "%sTimerSlackNSec: "NSEC_FMT "\n", prefix, c->timer_slack_nsec);
2182
2183         fprintf(f,
2184                 "%sStandardInput: %s\n"
2185                 "%sStandardOutput: %s\n"
2186                 "%sStandardError: %s\n",
2187                 prefix, exec_input_to_string(c->std_input),
2188                 prefix, exec_output_to_string(c->std_output),
2189                 prefix, exec_output_to_string(c->std_error));
2190
2191         if (c->tty_path)
2192                 fprintf(f,
2193                         "%sTTYPath: %s\n"
2194                         "%sTTYReset: %s\n"
2195                         "%sTTYVHangup: %s\n"
2196                         "%sTTYVTDisallocate: %s\n",
2197                         prefix, c->tty_path,
2198                         prefix, yes_no(c->tty_reset),
2199                         prefix, yes_no(c->tty_vhangup),
2200                         prefix, yes_no(c->tty_vt_disallocate));
2201
2202         if (c->std_output == EXEC_OUTPUT_SYSLOG ||
2203             c->std_output == EXEC_OUTPUT_KMSG ||
2204             c->std_output == EXEC_OUTPUT_JOURNAL ||
2205             c->std_output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE ||
2206             c->std_output == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
2207             c->std_output == EXEC_OUTPUT_JOURNAL_AND_CONSOLE ||
2208             c->std_error == EXEC_OUTPUT_SYSLOG ||
2209             c->std_error == EXEC_OUTPUT_KMSG ||
2210             c->std_error == EXEC_OUTPUT_JOURNAL ||
2211             c->std_error == EXEC_OUTPUT_SYSLOG_AND_CONSOLE ||
2212             c->std_error == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
2213             c->std_error == EXEC_OUTPUT_JOURNAL_AND_CONSOLE) {
2214
2215                 _cleanup_free_ char *fac_str = NULL, *lvl_str = NULL;
2216
2217                 log_facility_unshifted_to_string_alloc(c->syslog_priority >> 3, &fac_str);
2218                 log_level_to_string_alloc(LOG_PRI(c->syslog_priority), &lvl_str);
2219
2220                 fprintf(f,
2221                         "%sSyslogFacility: %s\n"
2222                         "%sSyslogLevel: %s\n",
2223                         prefix, strna(fac_str),
2224                         prefix, strna(lvl_str));
2225         }
2226
2227         if (c->capabilities) {
2228                 _cleanup_cap_free_charp_ char *t;
2229
2230                 t = cap_to_text(c->capabilities, NULL);
2231                 if (t)
2232                         fprintf(f, "%sCapabilities: %s\n", prefix, t);
2233         }
2234
2235         if (c->secure_bits)
2236                 fprintf(f, "%sSecure Bits:%s%s%s%s%s%s\n",
2237                         prefix,
2238                         (c->secure_bits & 1<<SECURE_KEEP_CAPS) ? " keep-caps" : "",
2239                         (c->secure_bits & 1<<SECURE_KEEP_CAPS_LOCKED) ? " keep-caps-locked" : "",
2240                         (c->secure_bits & 1<<SECURE_NO_SETUID_FIXUP) ? " no-setuid-fixup" : "",
2241                         (c->secure_bits & 1<<SECURE_NO_SETUID_FIXUP_LOCKED) ? " no-setuid-fixup-locked" : "",
2242                         (c->secure_bits & 1<<SECURE_NOROOT) ? " noroot" : "",
2243                         (c->secure_bits & 1<<SECURE_NOROOT_LOCKED) ? "noroot-locked" : "");
2244
2245         if (c->capability_bounding_set_drop) {
2246                 unsigned long l;
2247                 fprintf(f, "%sCapabilityBoundingSet:", prefix);
2248
2249                 for (l = 0; l <= cap_last_cap(); l++)
2250                         if (!(c->capability_bounding_set_drop & ((uint64_t) 1ULL << (uint64_t) l))) {
2251                                 _cleanup_cap_free_charp_ char *t;
2252
2253                                 t = cap_to_name(l);
2254                                 if (t)
2255                                         fprintf(f, " %s", t);
2256                         }
2257
2258                 fputs("\n", f);
2259         }
2260
2261         if (c->user)
2262                 fprintf(f, "%sUser: %s\n", prefix, c->user);
2263         if (c->group)
2264                 fprintf(f, "%sGroup: %s\n", prefix, c->group);
2265
2266         if (strv_length(c->supplementary_groups) > 0) {
2267                 fprintf(f, "%sSupplementaryGroups:", prefix);
2268                 strv_fprintf(f, c->supplementary_groups);
2269                 fputs("\n", f);
2270         }
2271
2272         if (c->pam_name)
2273                 fprintf(f, "%sPAMName: %s\n", prefix, c->pam_name);
2274
2275         if (strv_length(c->read_write_dirs) > 0) {
2276                 fprintf(f, "%sReadWriteDirs:", prefix);
2277                 strv_fprintf(f, c->read_write_dirs);
2278                 fputs("\n", f);
2279         }
2280
2281         if (strv_length(c->read_only_dirs) > 0) {
2282                 fprintf(f, "%sReadOnlyDirs:", prefix);
2283                 strv_fprintf(f, c->read_only_dirs);
2284                 fputs("\n", f);
2285         }
2286
2287         if (strv_length(c->inaccessible_dirs) > 0) {
2288                 fprintf(f, "%sInaccessibleDirs:", prefix);
2289                 strv_fprintf(f, c->inaccessible_dirs);
2290                 fputs("\n", f);
2291         }
2292
2293         if (c->utmp_id)
2294                 fprintf(f,
2295                         "%sUtmpIdentifier: %s\n",
2296                         prefix, c->utmp_id);
2297
2298         if (c->selinux_context)
2299                 fprintf(f,
2300                         "%sSELinuxContext: %s%s\n",
2301                         prefix, c->selinux_context_ignore ? "-" : "", c->selinux_context);
2302
2303         if (c->personality != 0xffffffffUL)
2304                 fprintf(f,
2305                         "%sPersonality: %s\n",
2306                         prefix, strna(personality_to_string(c->personality)));
2307
2308         if (c->syscall_filter) {
2309 #ifdef HAVE_SECCOMP
2310                 Iterator j;
2311                 void *id;
2312                 bool first = true;
2313 #endif
2314
2315                 fprintf(f,
2316                         "%sSystemCallFilter: ",
2317                         prefix);
2318
2319                 if (!c->syscall_whitelist)
2320                         fputc('~', f);
2321
2322 #ifdef HAVE_SECCOMP
2323                 SET_FOREACH(id, c->syscall_filter, j) {
2324                         _cleanup_free_ char *name = NULL;
2325
2326                         if (first)
2327                                 first = false;
2328                         else
2329                                 fputc(' ', f);
2330
2331                         name = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE, PTR_TO_INT(id) - 1);
2332                         fputs(strna(name), f);
2333                 }
2334 #endif
2335
2336                 fputc('\n', f);
2337         }
2338
2339         if (c->syscall_archs) {
2340 #ifdef HAVE_SECCOMP
2341                 Iterator j;
2342                 void *id;
2343 #endif
2344
2345                 fprintf(f,
2346                         "%sSystemCallArchitectures:",
2347                         prefix);
2348
2349 #ifdef HAVE_SECCOMP
2350                 SET_FOREACH(id, c->syscall_archs, j)
2351                         fprintf(f, " %s", strna(seccomp_arch_to_string(PTR_TO_UINT32(id) - 1)));
2352 #endif
2353                 fputc('\n', f);
2354         }
2355
2356         if (c->syscall_errno != 0)
2357                 fprintf(f,
2358                         "%sSystemCallErrorNumber: %s\n",
2359                         prefix, strna(errno_to_name(c->syscall_errno)));
2360
2361         if (c->apparmor_profile)
2362                 fprintf(f,
2363                         "%sAppArmorProfile: %s%s\n",
2364                         prefix, c->apparmor_profile_ignore ? "-" : "", c->apparmor_profile);
2365 }
2366
2367 void exec_status_start(ExecStatus *s, pid_t pid) {
2368         assert(s);
2369
2370         zero(*s);
2371         s->pid = pid;
2372         dual_timestamp_get(&s->start_timestamp);
2373 }
2374
2375 void exec_status_exit(ExecStatus *s, ExecContext *context, pid_t pid, int code, int status) {
2376         assert(s);
2377
2378         if (s->pid && s->pid != pid)
2379                 zero(*s);
2380
2381         s->pid = pid;
2382         dual_timestamp_get(&s->exit_timestamp);
2383
2384         s->code = code;
2385         s->status = status;
2386
2387         if (context) {
2388                 if (context->utmp_id)
2389                         utmp_put_dead_process(context->utmp_id, pid, code, status);
2390
2391                 exec_context_tty_reset(context);
2392         }
2393 }
2394
2395 void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix) {
2396         char buf[FORMAT_TIMESTAMP_MAX];
2397
2398         assert(s);
2399         assert(f);
2400
2401         if (!prefix)
2402                 prefix = "";
2403
2404         if (s->pid <= 0)
2405                 return;
2406
2407         fprintf(f,
2408                 "%sPID: "PID_FMT"\n",
2409                 prefix, s->pid);
2410
2411         if (s->start_timestamp.realtime > 0)
2412                 fprintf(f,
2413                         "%sStart Timestamp: %s\n",
2414                         prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp.realtime));
2415
2416         if (s->exit_timestamp.realtime > 0)
2417                 fprintf(f,
2418                         "%sExit Timestamp: %s\n"
2419                         "%sExit Code: %s\n"
2420                         "%sExit Status: %i\n",
2421                         prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp.realtime),
2422                         prefix, sigchld_code_to_string(s->code),
2423                         prefix, s->status);
2424 }
2425
2426 char *exec_command_line(char **argv) {
2427         size_t k;
2428         char *n, *p, **a;
2429         bool first = true;
2430
2431         assert(argv);
2432
2433         k = 1;
2434         STRV_FOREACH(a, argv)
2435                 k += strlen(*a)+3;
2436
2437         if (!(n = new(char, k)))
2438                 return NULL;
2439
2440         p = n;
2441         STRV_FOREACH(a, argv) {
2442
2443                 if (!first)
2444                         *(p++) = ' ';
2445                 else
2446                         first = false;
2447
2448                 if (strpbrk(*a, WHITESPACE)) {
2449                         *(p++) = '\'';
2450                         p = stpcpy(p, *a);
2451                         *(p++) = '\'';
2452                 } else
2453                         p = stpcpy(p, *a);
2454
2455         }
2456
2457         *p = 0;
2458
2459         /* FIXME: this doesn't really handle arguments that have
2460          * spaces and ticks in them */
2461
2462         return n;
2463 }
2464
2465 void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
2466         _cleanup_free_ char *p2 = NULL;
2467         const char *prefix2;
2468
2469         _cleanup_free_ char *cmd = NULL;
2470
2471         assert(c);
2472         assert(f);
2473
2474         if (!prefix)
2475                 prefix = "";
2476         p2 = strappend(prefix, "\t");
2477         prefix2 = p2 ? p2 : prefix;
2478
2479         cmd = exec_command_line(c->argv);
2480
2481         fprintf(f,
2482                 "%sCommand Line: %s\n",
2483                 prefix, cmd ? cmd : strerror(ENOMEM));
2484
2485         exec_status_dump(&c->exec_status, f, prefix2);
2486 }
2487
2488 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
2489         assert(f);
2490
2491         if (!prefix)
2492                 prefix = "";
2493
2494         LIST_FOREACH(command, c, c)
2495                 exec_command_dump(c, f, prefix);
2496 }
2497
2498 void exec_command_append_list(ExecCommand **l, ExecCommand *e) {
2499         ExecCommand *end;
2500
2501         assert(l);
2502         assert(e);
2503
2504         if (*l) {
2505                 /* It's kind of important, that we keep the order here */
2506                 LIST_FIND_TAIL(command, *l, end);
2507                 LIST_INSERT_AFTER(command, *l, end, e);
2508         } else
2509               *l = e;
2510 }
2511
2512 int exec_command_set(ExecCommand *c, const char *path, ...) {
2513         va_list ap;
2514         char **l, *p;
2515
2516         assert(c);
2517         assert(path);
2518
2519         va_start(ap, path);
2520         l = strv_new_ap(path, ap);
2521         va_end(ap);
2522
2523         if (!l)
2524                 return -ENOMEM;
2525
2526         p = strdup(path);
2527         if (!p) {
2528                 strv_free(l);
2529                 return -ENOMEM;
2530         }
2531
2532         free(c->path);
2533         c->path = p;
2534
2535         strv_free(c->argv);
2536         c->argv = l;
2537
2538         return 0;
2539 }
2540
2541 static int exec_runtime_allocate(ExecRuntime **rt) {
2542
2543         if (*rt)
2544                 return 0;
2545
2546         *rt = new0(ExecRuntime, 1);
2547         if (!*rt)
2548                 return -ENOMEM;
2549
2550         (*rt)->n_ref = 1;
2551         (*rt)->netns_storage_socket[0] = (*rt)->netns_storage_socket[1] = -1;
2552
2553         return 0;
2554 }
2555
2556 int exec_runtime_make(ExecRuntime **rt, ExecContext *c, const char *id) {
2557         int r;
2558
2559         assert(rt);
2560         assert(c);
2561         assert(id);
2562
2563         if (*rt)
2564                 return 1;
2565
2566         if (!c->private_network && !c->private_tmp)
2567                 return 0;
2568
2569         r = exec_runtime_allocate(rt);
2570         if (r < 0)
2571                 return r;
2572
2573         if (c->private_network && (*rt)->netns_storage_socket[0] < 0) {
2574                 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, (*rt)->netns_storage_socket) < 0)
2575                         return -errno;
2576         }
2577
2578         if (c->private_tmp && !(*rt)->tmp_dir) {
2579                 r = setup_tmp_dirs(id, &(*rt)->tmp_dir, &(*rt)->var_tmp_dir);
2580                 if (r < 0)
2581                         return r;
2582         }
2583
2584         return 1;
2585 }
2586
2587 ExecRuntime *exec_runtime_ref(ExecRuntime *r) {
2588         assert(r);
2589         assert(r->n_ref > 0);
2590
2591         r->n_ref++;
2592         return r;
2593 }
2594
2595 ExecRuntime *exec_runtime_unref(ExecRuntime *r) {
2596
2597         if (!r)
2598                 return NULL;
2599
2600         assert(r->n_ref > 0);
2601
2602         r->n_ref--;
2603         if (r->n_ref <= 0) {
2604                 free(r->tmp_dir);
2605                 free(r->var_tmp_dir);
2606                 safe_close_pair(r->netns_storage_socket);
2607                 free(r);
2608         }
2609
2610         return NULL;
2611 }
2612
2613 int exec_runtime_serialize(ExecRuntime *rt, Unit *u, FILE *f, FDSet *fds) {
2614         assert(u);
2615         assert(f);
2616         assert(fds);
2617
2618         if (!rt)
2619                 return 0;
2620
2621         if (rt->tmp_dir)
2622                 unit_serialize_item(u, f, "tmp-dir", rt->tmp_dir);
2623
2624         if (rt->var_tmp_dir)
2625                 unit_serialize_item(u, f, "var-tmp-dir", rt->var_tmp_dir);
2626
2627         if (rt->netns_storage_socket[0] >= 0) {
2628                 int copy;
2629
2630                 copy = fdset_put_dup(fds, rt->netns_storage_socket[0]);
2631                 if (copy < 0)
2632                         return copy;
2633
2634                 unit_serialize_item_format(u, f, "netns-socket-0", "%i", copy);
2635         }
2636
2637         if (rt->netns_storage_socket[1] >= 0) {
2638                 int copy;
2639
2640                 copy = fdset_put_dup(fds, rt->netns_storage_socket[1]);
2641                 if (copy < 0)
2642                         return copy;
2643
2644                 unit_serialize_item_format(u, f, "netns-socket-1", "%i", copy);
2645         }
2646
2647         return 0;
2648 }
2649
2650 int exec_runtime_deserialize_item(ExecRuntime **rt, Unit *u, const char *key, const char *value, FDSet *fds) {
2651         int r;
2652
2653         assert(rt);
2654         assert(key);
2655         assert(value);
2656
2657         if (streq(key, "tmp-dir")) {
2658                 char *copy;
2659
2660                 r = exec_runtime_allocate(rt);
2661                 if (r < 0)
2662                         return r;
2663
2664                 copy = strdup(value);
2665                 if (!copy)
2666                         return log_oom();
2667
2668                 free((*rt)->tmp_dir);
2669                 (*rt)->tmp_dir = copy;
2670
2671         } else if (streq(key, "var-tmp-dir")) {
2672                 char *copy;
2673
2674                 r = exec_runtime_allocate(rt);
2675                 if (r < 0)
2676                         return r;
2677
2678                 copy = strdup(value);
2679                 if (!copy)
2680                         return log_oom();
2681
2682                 free((*rt)->var_tmp_dir);
2683                 (*rt)->var_tmp_dir = copy;
2684
2685         } else if (streq(key, "netns-socket-0")) {
2686                 int fd;
2687
2688                 r = exec_runtime_allocate(rt);
2689                 if (r < 0)
2690                         return r;
2691
2692                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd))
2693                         log_debug_unit(u->id, "Failed to parse netns socket value %s", value);
2694                 else {
2695                         safe_close((*rt)->netns_storage_socket[0]);
2696                         (*rt)->netns_storage_socket[0] = fdset_remove(fds, fd);
2697                 }
2698         } else if (streq(key, "netns-socket-1")) {
2699                 int fd;
2700
2701                 r = exec_runtime_allocate(rt);
2702                 if (r < 0)
2703                         return r;
2704
2705                 if (safe_atoi(value, &fd) < 0 || !fdset_contains(fds, fd))
2706                         log_debug_unit(u->id, "Failed to parse netns socket value %s", value);
2707                 else {
2708                         safe_close((*rt)->netns_storage_socket[1]);
2709                         (*rt)->netns_storage_socket[1] = fdset_remove(fds, fd);
2710                 }
2711         } else
2712                 return 0;
2713
2714         return 1;
2715 }
2716
2717 static void *remove_tmpdir_thread(void *p) {
2718         _cleanup_free_ char *path = p;
2719
2720         rm_rf_dangerous(path, false, true, false);
2721         return NULL;
2722 }
2723
2724 void exec_runtime_destroy(ExecRuntime *rt) {
2725         int r;
2726
2727         if (!rt)
2728                 return;
2729
2730         /* If there are multiple users of this, let's leave the stuff around */
2731         if (rt->n_ref > 1)
2732                 return;
2733
2734         if (rt->tmp_dir) {
2735                 log_debug("Spawning thread to nuke %s", rt->tmp_dir);
2736
2737                 r = asynchronous_job(remove_tmpdir_thread, rt->tmp_dir);
2738                 if (r < 0) {
2739                         log_warning("Failed to nuke %s: %s", rt->tmp_dir, strerror(-r));
2740                         free(rt->tmp_dir);
2741                 }
2742
2743                 rt->tmp_dir = NULL;
2744         }
2745
2746         if (rt->var_tmp_dir) {
2747                 log_debug("Spawning thread to nuke %s", rt->var_tmp_dir);
2748
2749                 r = asynchronous_job(remove_tmpdir_thread, rt->var_tmp_dir);
2750                 if (r < 0) {
2751                         log_warning("Failed to nuke %s: %s", rt->var_tmp_dir, strerror(-r));
2752                         free(rt->var_tmp_dir);
2753                 }
2754
2755                 rt->var_tmp_dir = NULL;
2756         }
2757
2758         safe_close_pair(rt->netns_storage_socket);
2759 }
2760
2761 static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
2762         [EXEC_INPUT_NULL] = "null",
2763         [EXEC_INPUT_TTY] = "tty",
2764         [EXEC_INPUT_TTY_FORCE] = "tty-force",
2765         [EXEC_INPUT_TTY_FAIL] = "tty-fail",
2766         [EXEC_INPUT_SOCKET] = "socket"
2767 };
2768
2769 DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);
2770
2771 static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
2772         [EXEC_OUTPUT_INHERIT] = "inherit",
2773         [EXEC_OUTPUT_NULL] = "null",
2774         [EXEC_OUTPUT_TTY] = "tty",
2775         [EXEC_OUTPUT_SYSLOG] = "syslog",
2776         [EXEC_OUTPUT_SYSLOG_AND_CONSOLE] = "syslog+console",
2777         [EXEC_OUTPUT_KMSG] = "kmsg",
2778         [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
2779         [EXEC_OUTPUT_JOURNAL] = "journal",
2780         [EXEC_OUTPUT_JOURNAL_AND_CONSOLE] = "journal+console",
2781         [EXEC_OUTPUT_SOCKET] = "socket"
2782 };
2783
2784 DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);