src/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 General Public License as published by
  10   the Free Software Foundation; either version 2 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   General Public License for more details.
  17
  18   You should have received a copy of the GNU 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
  41 #ifdef HAVE_PAM
  42 #include <security/pam_appl.h>
  43 #endif
  44
  45 #include "execute.h"
  46 #include "strv.h"
  47 #include "macro.h"
  48 #include "util.h"
  49 #include "log.h"
  50 #include "ioprio.h"
  51 #include "securebits.h"
  52 #include "cgroup.h"
  53 #include "namespace.h"
  54 #include "tcpwrap.h"
  55 #include "exit-status.h"
  56 #include "missing.h"
  57 #include "utmp-wtmp.h"
  58
  59 /* This assumes there is a 'tty' group */
  60 #define TTY_MODE 0620
  61
  62 static int shift_fds(int fds[], unsigned n_fds) {
  63         int start, restart_from;
  64
  65         if (n_fds <= 0)
  66                 return 0;
  67
  68         /* Modifies the fds array! (sorts it) */
  69
  70         assert(fds);
  71
  72         start = 0;
  73         for (;;) {
  74                 int i;
  75
  76                 restart_from = -1;
  77
  78                 for (i = start; i < (int) n_fds; i++) {
  79                         int nfd;
  80
  81                         /* Already at right index? */
  82                         if (fds[i] == i+3)
  83                                 continue;
  84
  85                         if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)
  86                                 return -errno;
  87
  88                         close_nointr_nofail(fds[i]);
  89                         fds[i] = nfd;
  90
  91                         /* Hmm, the fd we wanted isn't free? Then
  92                          * let's remember that and try again from here*/
  93                         if (nfd != i+3 && restart_from < 0)
  94                                 restart_from = i;
  95                 }
  96
  97                 if (restart_from < 0)
  98                         break;
  99
 100                 start = restart_from;
 101         }
 102
 103         return 0;
 104 }
 105
 106 static int flags_fds(const int fds[], unsigned n_fds, bool nonblock) {
 107         unsigned i;
 108         int r;
 109
 110         if (n_fds <= 0)
 111                 return 0;
 112
 113         assert(fds);
 114
 115         /* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags */
 116
 117         for (i = 0; i < n_fds; i++) {
 118
 119                 if ((r = fd_nonblock(fds[i], nonblock)) < 0)
 120                         return r;
 121
 122                 /* We unconditionally drop FD_CLOEXEC from the fds,
 123                  * since after all we want to pass these fds to our
 124                  * children */
 125
 126                 if ((r = fd_cloexec(fds[i], false)) < 0)
 127                         return r;
 128         }
 129
 130         return 0;
 131 }
 132
 133 static const char *tty_path(const ExecContext *context) {
 134         assert(context);
 135
 136         if (context->tty_path)
 137                 return context->tty_path;
 138
 139         return "/dev/console";
 140 }
 141
 142 static int open_null_as(int flags, int nfd) {
 143         int fd, r;
 144
 145         assert(nfd >= 0);
 146
 147         if ((fd = open("/dev/null", flags|O_NOCTTY)) < 0)
 148                 return -errno;
 149
 150         if (fd != nfd) {
 151                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 152                 close_nointr_nofail(fd);
 153         } else
 154                 r = nfd;
 155
 156         return r;
 157 }
 158
 159 static int connect_logger_as(const ExecContext *context, ExecOutput output, const char *ident, int nfd) {
 160         int fd, r;
 161         union {
 162                 struct sockaddr sa;
 163                 struct sockaddr_un un;
 164         } sa;
 165
 166         assert(context);
 167         assert(output < _EXEC_OUTPUT_MAX);
 168         assert(ident);
 169         assert(nfd >= 0);
 170
 171         if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 172                 return -errno;
 173
 174         zero(sa);
 175         sa.sa.sa_family = AF_UNIX;
 176         strncpy(sa.un.sun_path+1, LOGGER_SOCKET, sizeof(sa.un.sun_path)-1);
 177
 178         if (connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + 1 + sizeof(LOGGER_SOCKET) - 1) < 0) {
 179                 close_nointr_nofail(fd);
 180                 return -errno;
 181         }
 182
 183         if (shutdown(fd, SHUT_RD) < 0) {
 184                 close_nointr_nofail(fd);
 185                 return -errno;
 186         }
 187
 188         /* We speak a very simple protocol between log server
 189          * and client: one line for the log destination (kmsg
 190          * or syslog), followed by the priority field,
 191          * followed by the process name. Since we replaced
 192          * stdin/stderr we simple use stdio to write to
 193          * it. Note that we use stderr, to minimize buffer
 194          * flushing issues. */
 195
 196         dprintf(fd,
 197                 "%s\n"
 198                 "%i\n"
 199                 "%s\n"
 200                 "%i\n",
 201                 output == EXEC_OUTPUT_KMSG ?             "kmsg" :
 202                 output == EXEC_OUTPUT_KMSG_AND_CONSOLE ? "kmsg+console" :
 203                 output == EXEC_OUTPUT_SYSLOG ?           "syslog" :
 204                                                          "syslog+console",
 205                 context->syslog_priority,
 206                 context->syslog_identifier ? context->syslog_identifier : ident,
 207                 context->syslog_level_prefix);
 208
 209         if (fd != nfd) {
 210                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 211                 close_nointr_nofail(fd);
 212         } else
 213                 r = nfd;
 214
 215         return r;
 216 }
 217 static int open_terminal_as(const char *path, mode_t mode, int nfd) {
 218         int fd, r;
 219
 220         assert(path);
 221         assert(nfd >= 0);
 222
 223         if ((fd = open_terminal(path, mode | O_NOCTTY)) < 0)
 224                 return fd;
 225
 226         if (fd != nfd) {
 227                 r = dup2(fd, nfd) < 0 ? -errno : nfd;
 228                 close_nointr_nofail(fd);
 229         } else
 230                 r = nfd;
 231
 232         return r;
 233 }
 234
 235 static bool is_terminal_input(ExecInput i) {
 236         return
 237                 i == EXEC_INPUT_TTY ||
 238                 i == EXEC_INPUT_TTY_FORCE ||
 239                 i == EXEC_INPUT_TTY_FAIL;
 240 }
 241
 242 static int fixup_input(ExecInput std_input, int socket_fd, bool apply_tty_stdin) {
 243
 244         if (is_terminal_input(std_input) && !apply_tty_stdin)
 245                 return EXEC_INPUT_NULL;
 246
 247         if (std_input == EXEC_INPUT_SOCKET && socket_fd < 0)
 248                 return EXEC_INPUT_NULL;
 249
 250         return std_input;
 251 }
 252
 253 static int fixup_output(ExecOutput std_output, int socket_fd) {
 254
 255         if (std_output == EXEC_OUTPUT_SOCKET && socket_fd < 0)
 256                 return EXEC_OUTPUT_INHERIT;
 257
 258         return std_output;
 259 }
 260
 261 static int setup_input(const ExecContext *context, int socket_fd, bool apply_tty_stdin) {
 262         ExecInput i;
 263
 264         assert(context);
 265
 266         i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);
 267
 268         switch (i) {
 269
 270         case EXEC_INPUT_NULL:
 271                 return open_null_as(O_RDONLY, STDIN_FILENO);
 272
 273         case EXEC_INPUT_TTY:
 274         case EXEC_INPUT_TTY_FORCE:
 275         case EXEC_INPUT_TTY_FAIL: {
 276                 int fd, r;
 277
 278                 if ((fd = acquire_terminal(
 279                                      tty_path(context),
 280                                      i == EXEC_INPUT_TTY_FAIL,
 281                                      i == EXEC_INPUT_TTY_FORCE,
 282                                      false)) < 0)
 283                         return fd;
 284
 285                 if (fd != STDIN_FILENO) {
 286                         r = dup2(fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 287                         close_nointr_nofail(fd);
 288                 } else
 289                         r = STDIN_FILENO;
 290
 291                 return r;
 292         }
 293
 294         case EXEC_INPUT_SOCKET:
 295                 return dup2(socket_fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
 296
 297         default:
 298                 assert_not_reached("Unknown input type");
 299         }
 300 }
 301
 302 static int setup_output(const ExecContext *context, int socket_fd, const char *ident, bool apply_tty_stdin) {
 303         ExecOutput o;
 304         ExecInput i;
 305
 306         assert(context);
 307         assert(ident);
 308
 309         i = fixup_input(context->std_input, socket_fd, apply_tty_stdin);
 310         o = fixup_output(context->std_output, socket_fd);
 311
 312         /* This expects the input is already set up */
 313
 314         switch (o) {
 315
 316         case EXEC_OUTPUT_INHERIT:
 317
 318                 /* If input got downgraded, inherit the original value */
 319                 if (i == EXEC_INPUT_NULL && is_terminal_input(context->std_input))
 320                         return open_terminal_as(tty_path(context), O_WRONLY, STDOUT_FILENO);
 321
 322                 /* If the input is connected to anything that's not a /dev/null, inherit that... */
 323                 if (i != EXEC_INPUT_NULL)
 324                         return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;
 325
 326                 /* If we are not started from PID 1 we just inherit STDOUT from our parent process. */
 327                 if (getppid() != 1)
 328                         return STDOUT_FILENO;
 329
 330                 /* We need to open /dev/null here anew, to get the
 331                  * right access mode. So we fall through */
 332
 333         case EXEC_OUTPUT_NULL:
 334                 return open_null_as(O_WRONLY, STDOUT_FILENO);
 335
 336         case EXEC_OUTPUT_TTY:
 337                 if (is_terminal_input(i))
 338                         return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;
 339
 340                 /* We don't reset the terminal if this is just about output */
 341                 return open_terminal_as(tty_path(context), O_WRONLY, STDOUT_FILENO);
 342
 343         case EXEC_OUTPUT_SYSLOG:
 344         case EXEC_OUTPUT_SYSLOG_AND_CONSOLE:
 345         case EXEC_OUTPUT_KMSG:
 346         case EXEC_OUTPUT_KMSG_AND_CONSOLE:
 347                 return connect_logger_as(context, o, ident, STDOUT_FILENO);
 348
 349         case EXEC_OUTPUT_SOCKET:
 350                 assert(socket_fd >= 0);
 351                 return dup2(socket_fd, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;
 352
 353         default:
 354                 assert_not_reached("Unknown output type");
 355         }
 356 }
 357
 358 static int setup_error(const ExecContext *context, int socket_fd, const char *ident, bool apply_tty_stdin) {
 359         ExecOutput o, e;
 360         ExecInput i;
 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         e = fixup_output(context->std_error, socket_fd);
 368
 369         /* This expects the input and output are already set up */
 370
 371         /* Don't change the stderr file descriptor if we inherit all
 372          * the way and are not on a tty */
 373         if (e == EXEC_OUTPUT_INHERIT &&
 374             o == EXEC_OUTPUT_INHERIT &&
 375             i == EXEC_INPUT_NULL &&
 376             !is_terminal_input(context->std_input) &&
 377             getppid () != 1)
 378                 return STDERR_FILENO;
 379
 380         /* Duplicate from stdout if possible */
 381         if (e == o || e == EXEC_OUTPUT_INHERIT)
 382                 return dup2(STDOUT_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;
 383
 384         switch (e) {
 385
 386         case EXEC_OUTPUT_NULL:
 387                 return open_null_as(O_WRONLY, STDERR_FILENO);
 388
 389         case EXEC_OUTPUT_TTY:
 390                 if (is_terminal_input(i))
 391                         return dup2(STDIN_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;
 392
 393                 /* We don't reset the terminal if this is just about output */
 394                 return open_terminal_as(tty_path(context), O_WRONLY, STDERR_FILENO);
 395
 396         case EXEC_OUTPUT_SYSLOG:
 397         case EXEC_OUTPUT_SYSLOG_AND_CONSOLE:
 398         case EXEC_OUTPUT_KMSG:
 399         case EXEC_OUTPUT_KMSG_AND_CONSOLE:
 400                 return connect_logger_as(context, e, ident, STDERR_FILENO);
 401
 402         case EXEC_OUTPUT_SOCKET:
 403                 assert(socket_fd >= 0);
 404                 return dup2(socket_fd, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;
 405
 406         default:
 407                 assert_not_reached("Unknown error type");
 408         }
 409 }
 410
 411 static int chown_terminal(int fd, uid_t uid) {
 412         struct stat st;
 413
 414         assert(fd >= 0);
 415
 416         /* This might fail. What matters are the results. */
 417         (void) fchown(fd, uid, -1);
 418         (void) fchmod(fd, TTY_MODE);
 419
 420         if (fstat(fd, &st) < 0)
 421                 return -errno;
 422
 423         if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE)
 424                 return -EPERM;
 425
 426         return 0;
 427 }
 428
 429 static int setup_confirm_stdio(const ExecContext *context,
 430                                int *_saved_stdin,
 431                                int *_saved_stdout) {
 432         int fd = -1, saved_stdin, saved_stdout = -1, r;
 433
 434         assert(context);
 435         assert(_saved_stdin);
 436         assert(_saved_stdout);
 437
 438         /* This returns positive EXIT_xxx return values instead of
 439          * negative errno style values! */
 440
 441         if ((saved_stdin = fcntl(STDIN_FILENO, F_DUPFD, 3)) < 0)
 442                 return EXIT_STDIN;
 443
 444         if ((saved_stdout = fcntl(STDOUT_FILENO, F_DUPFD, 3)) < 0) {
 445                 r = EXIT_STDOUT;
 446                 goto fail;
 447         }
 448
 449         if ((fd = acquire_terminal(
 450                              tty_path(context),
 451                              context->std_input == EXEC_INPUT_TTY_FAIL,
 452                              context->std_input == EXEC_INPUT_TTY_FORCE,
 453                              false)) < 0) {
 454                 r = EXIT_STDIN;
 455                 goto fail;
 456         }
 457
 458         if (chown_terminal(fd, getuid()) < 0) {
 459                 r = EXIT_STDIN;
 460                 goto fail;
 461         }
 462
 463         if (dup2(fd, STDIN_FILENO) < 0) {
 464                 r = EXIT_STDIN;
 465                 goto fail;
 466         }
 467
 468         if (dup2(fd, STDOUT_FILENO) < 0) {
 469                 r = EXIT_STDOUT;
 470                 goto fail;
 471         }
 472
 473         if (fd >= 2)
 474                 close_nointr_nofail(fd);
 475
 476         *_saved_stdin = saved_stdin;
 477         *_saved_stdout = saved_stdout;
 478
 479         return 0;
 480
 481 fail:
 482         if (saved_stdout >= 0)
 483                 close_nointr_nofail(saved_stdout);
 484
 485         if (saved_stdin >= 0)
 486                 close_nointr_nofail(saved_stdin);
 487
 488         if (fd >= 0)
 489                 close_nointr_nofail(fd);
 490
 491         return r;
 492 }
 493
 494 static int restore_confirm_stdio(const ExecContext *context,
 495                                  int *saved_stdin,
 496                                  int *saved_stdout,
 497                                  bool *keep_stdin,
 498                                  bool *keep_stdout) {
 499
 500         assert(context);
 501         assert(saved_stdin);
 502         assert(*saved_stdin >= 0);
 503         assert(saved_stdout);
 504         assert(*saved_stdout >= 0);
 505
 506         /* This returns positive EXIT_xxx return values instead of
 507          * negative errno style values! */
 508
 509         if (is_terminal_input(context->std_input)) {
 510
 511                 /* The service wants terminal input. */
 512
 513                 *keep_stdin = true;
 514                 *keep_stdout =
 515                         context->std_output == EXEC_OUTPUT_INHERIT ||
 516                         context->std_output == EXEC_OUTPUT_TTY;
 517
 518         } else {
 519                 /* If the service doesn't want a controlling terminal,
 520                  * then we need to get rid entirely of what we have
 521                  * already. */
 522
 523                 if (release_terminal() < 0)
 524                         return EXIT_STDIN;
 525
 526                 if (dup2(*saved_stdin, STDIN_FILENO) < 0)
 527                         return EXIT_STDIN;
 528
 529                 if (dup2(*saved_stdout, STDOUT_FILENO) < 0)
 530                         return EXIT_STDOUT;
 531
 532                 *keep_stdout = *keep_stdin = false;
 533         }
 534
 535         return 0;
 536 }
 537
 538 static int get_group_creds(const char *groupname, gid_t *gid) {
 539         struct group *g;
 540         unsigned long lu;
 541
 542         assert(groupname);
 543         assert(gid);
 544
 545         /* We enforce some special rules for gid=0: in order to avoid
 546          * NSS lookups for root we hardcode its data. */
 547
 548         if (streq(groupname, "root") || streq(groupname, "0")) {
 549                 *gid = 0;
 550                 return 0;
 551         }
 552
 553         if (safe_atolu(groupname, &lu) >= 0) {
 554                 errno = 0;
 555                 g = getgrgid((gid_t) lu);
 556         } else {
 557                 errno = 0;
 558                 g = getgrnam(groupname);
 559         }
 560
 561         if (!g)
 562                 return errno != 0 ? -errno : -ESRCH;
 563
 564         *gid = g->gr_gid;
 565         return 0;
 566 }
 567
 568 static int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home) {
 569         struct passwd *p;
 570         unsigned long lu;
 571
 572         assert(username);
 573         assert(*username);
 574         assert(uid);
 575         assert(gid);
 576         assert(home);
 577
 578         /* We enforce some special rules for uid=0: in order to avoid
 579          * NSS lookups for root we hardcode its data. */
 580
 581         if (streq(*username, "root") || streq(*username, "0")) {
 582                 *username = "root";
 583                 *uid = 0;
 584                 *gid = 0;
 585                 *home = "/root";
 586                 return 0;
 587         }
 588
 589         if (safe_atolu(*username, &lu) >= 0) {
 590                 errno = 0;
 591                 p = getpwuid((uid_t) lu);
 592
 593                 /* If there are multiple users with the same id, make
 594                  * sure to leave $USER to the configured value instead
 595                  * of the first occurrence in the database. However if
 596                  * the uid was configured by a numeric uid, then let's
 597                  * pick the real username from /etc/passwd. */
 598                 if (*username && p)
 599                         *username = p->pw_name;
 600         } else {
 601                 errno = 0;
 602                 p = getpwnam(*username);
 603         }
 604
 605         if (!p)
 606                 return errno != 0 ? -errno : -ESRCH;
 607
 608         *uid = p->pw_uid;
 609         *gid = p->pw_gid;
 610         *home = p->pw_dir;
 611         return 0;
 612 }
 613
 614 static int enforce_groups(const ExecContext *context, const char *username, gid_t gid) {
 615         bool keep_groups = false;
 616         int r;
 617
 618         assert(context);
 619
 620         /* Lookup and set GID and supplementary group list. Here too
 621          * we avoid NSS lookups for gid=0. */
 622
 623         if (context->group || username) {
 624
 625                 if (context->group)
 626                         if ((r = get_group_creds(context->group, &gid)) < 0)
 627                                 return r;
 628
 629                 /* First step, initialize groups from /etc/groups */
 630                 if (username && gid != 0) {
 631                         if (initgroups(username, gid) < 0)
 632                                 return -errno;
 633
 634                         keep_groups = true;
 635                 }
 636
 637                 /* Second step, set our gids */
 638                 if (setresgid(gid, gid, gid) < 0)
 639                         return -errno;
 640         }
 641
 642         if (context->supplementary_groups) {
 643                 int ngroups_max, k;
 644                 gid_t *gids;
 645                 char **i;
 646
 647                 /* Final step, initialize any manually set supplementary groups */
 648                 ngroups_max = (int) sysconf(_SC_NGROUPS_MAX);
 649
 650                 if (!(gids = new(gid_t, ngroups_max)))
 651                         return -ENOMEM;
 652
 653                 if (keep_groups) {
 654                         if ((k = getgroups(ngroups_max, gids)) < 0) {
 655                                 free(gids);
 656                                 return -errno;
 657                         }
 658                 } else
 659                         k = 0;
 660
 661                 STRV_FOREACH(i, context->supplementary_groups) {
 662
 663                         if (k >= ngroups_max) {
 664                                 free(gids);
 665                                 return -E2BIG;
 666                         }
 667
 668                         if ((r = get_group_creds(*i, gids+k)) < 0) {
 669                                 free(gids);
 670                                 return r;
 671                         }
 672
 673                         k++;
 674                 }
 675
 676                 if (setgroups(k, gids) < 0) {
 677                         free(gids);
 678                         return -errno;
 679                 }
 680
 681                 free(gids);
 682         }
 683
 684         return 0;
 685 }
 686
 687 static int enforce_user(const ExecContext *context, uid_t uid) {
 688         int r;
 689         assert(context);
 690
 691         /* Sets (but doesn't lookup) the uid and make sure we keep the
 692          * capabilities while doing so. */
 693
 694         if (context->capabilities) {
 695                 cap_t d;
 696                 static const cap_value_t bits[] = {
 697                         CAP_SETUID,   /* Necessary so that we can run setresuid() below */
 698                         CAP_SETPCAP   /* Necessary so that we can set PR_SET_SECUREBITS later on */
 699                 };
 700
 701                 /* First step: If we need to keep capabilities but
 702                  * drop privileges we need to make sure we keep our
 703                  * caps, whiel we drop privileges. */
 704                 if (uid != 0) {
 705                         int sb = context->secure_bits|SECURE_KEEP_CAPS;
 706
 707                         if (prctl(PR_GET_SECUREBITS) != sb)
 708                                 if (prctl(PR_SET_SECUREBITS, sb) < 0)
 709                                         return -errno;
 710                 }
 711
 712                 /* Second step: set the capabilities. This will reduce
 713                  * the capabilities to the minimum we need. */
 714
 715                 if (!(d = cap_dup(context->capabilities)))
 716                         return -errno;
 717
 718                 if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 ||
 719                     cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0) {
 720                         r = -errno;
 721                         cap_free(d);
 722                         return r;
 723                 }
 724
 725                 if (cap_set_proc(d) < 0) {
 726                         r = -errno;
 727                         cap_free(d);
 728                         return r;
 729                 }
 730
 731                 cap_free(d);
 732         }
 733
 734         /* Third step: actually set the uids */
 735         if (setresuid(uid, uid, uid) < 0)
 736                 return -errno;
 737
 738         /* At this point we should have all necessary capabilities but
 739            are otherwise a normal user. However, the caps might got
 740            corrupted due to the setresuid() so we need clean them up
 741            later. This is done outside of this call. */
 742
 743         return 0;
 744 }
 745
 746 #ifdef HAVE_PAM
 747
 748 static int null_conv(
 749                 int num_msg,
 750                 const struct pam_message **msg,
 751                 struct pam_response **resp,
 752                 void *appdata_ptr) {
 753
 754         /* We don't support conversations */
 755
 756         return PAM_CONV_ERR;
 757 }
 758
 759 static int setup_pam(
 760                 const char *name,
 761                 const char *user,
 762                 const char *tty,
 763                 char ***pam_env,
 764                 int fds[], unsigned n_fds) {
 765
 766         static const struct pam_conv conv = {
 767                 .conv = null_conv,
 768                 .appdata_ptr = NULL
 769         };
 770
 771         pam_handle_t *handle = NULL;
 772         sigset_t ss, old_ss;
 773         int pam_code = PAM_SUCCESS;
 774         char **e = NULL;
 775         bool close_session = false;
 776         pid_t pam_pid = 0, parent_pid;
 777
 778         assert(name);
 779         assert(user);
 780         assert(pam_env);
 781
 782         /* We set up PAM in the parent process, then fork. The child
 783          * will then stay around until killed via PR_GET_PDEATHSIG or
 784          * systemd via the cgroup logic. It will then remove the PAM
 785          * session again. The parent process will exec() the actual
 786          * daemon. We do things this way to ensure that the main PID
 787          * of the daemon is the one we initially fork()ed. */
 788
 789         if ((pam_code = pam_start(name, user, &conv, &handle)) != PAM_SUCCESS) {
 790                 handle = NULL;
 791                 goto fail;
 792         }
 793
 794         if (tty)
 795                 if ((pam_code = pam_set_item(handle, PAM_TTY, tty)) != PAM_SUCCESS)
 796                         goto fail;
 797
 798         if ((pam_code = pam_acct_mgmt(handle, PAM_SILENT)) != PAM_SUCCESS)
 799                 goto fail;
 800
 801         if ((pam_code = pam_open_session(handle, PAM_SILENT)) != PAM_SUCCESS)
 802                 goto fail;
 803
 804         close_session = true;
 805
 806         if ((pam_code = pam_setcred(handle, PAM_ESTABLISH_CRED | PAM_SILENT)) != PAM_SUCCESS)
 807                 goto fail;
 808
 809         if ((!(e = pam_getenvlist(handle)))) {
 810                 pam_code = PAM_BUF_ERR;
 811                 goto fail;
 812         }
 813
 814         /* Block SIGTERM, so that we know that it won't get lost in
 815          * the child */
 816         if (sigemptyset(&ss) < 0 ||
 817             sigaddset(&ss, SIGTERM) < 0 ||
 818             sigprocmask(SIG_BLOCK, &ss, &old_ss) < 0)
 819                 goto fail;
 820
 821         parent_pid = getpid();
 822
 823         if ((pam_pid = fork()) < 0)
 824                 goto fail;
 825
 826         if (pam_pid == 0) {
 827                 int sig;
 828                 int r = EXIT_PAM;
 829
 830                 /* The child's job is to reset the PAM session on
 831                  * termination */
 832
 833                 /* This string must fit in 10 chars (i.e. the length
 834                  * of "/sbin/init") */
 835                 rename_process("sd:pam");
 836
 837                 /* Make sure we don't keep open the passed fds in this
 838                 child. We assume that otherwise only those fds are
 839                 open here that have been opened by PAM. */
 840                 close_many(fds, n_fds);
 841
 842                 /* Wait until our parent died. This will most likely
 843                  * not work since the kernel does not allow
 844                  * unprivileged parents kill their privileged children
 845                  * this way. We rely on the control groups kill logic
 846                  * to do the rest for us. */
 847                 if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)
 848                         goto child_finish;
 849
 850                 /* Check if our parent process might already have
 851                  * died? */
 852                 if (getppid() == parent_pid) {
 853                         if (sigwait(&ss, &sig) < 0)
 854                                 goto child_finish;
 855
 856                         assert(sig == SIGTERM);
 857                 }
 858
 859                 /* Only if our parent died we'll end the session */
 860                 if (getppid() != parent_pid)
 861                         if ((pam_code = pam_close_session(handle, PAM_DATA_SILENT)) != PAM_SUCCESS)
 862                                 goto child_finish;
 863
 864                 r = 0;
 865
 866         child_finish:
 867                 pam_end(handle, pam_code | PAM_DATA_SILENT);
 868                 _exit(r);
 869         }
 870
 871         /* If the child was forked off successfully it will do all the
 872          * cleanups, so forget about the handle here. */
 873         handle = NULL;
 874
 875         /* Unblock SIGSUR1 again in the parent */
 876         if (sigprocmask(SIG_SETMASK, &old_ss, NULL) < 0)
 877                 goto fail;
 878
 879         /* We close the log explicitly here, since the PAM modules
 880          * might have opened it, but we don't want this fd around. */
 881         closelog();
 882
 883         return 0;
 884
 885 fail:
 886         if (handle) {
 887                 if (close_session)
 888                         pam_code = pam_close_session(handle, PAM_DATA_SILENT);
 889
 890                 pam_end(handle, pam_code | PAM_DATA_SILENT);
 891         }
 892
 893         strv_free(e);
 894
 895         closelog();
 896
 897         if (pam_pid > 1) {
 898                 kill(pam_pid, SIGTERM);
 899                 kill(pam_pid, SIGCONT);
 900         }
 901
 902         return EXIT_PAM;
 903 }
 904 #endif
 905
 906 int exec_spawn(ExecCommand *command,
 907                char **argv,
 908                const ExecContext *context,
 909                int fds[], unsigned n_fds,
 910                char **environment,
 911                bool apply_permissions,
 912                bool apply_chroot,
 913                bool apply_tty_stdin,
 914                bool confirm_spawn,
 915                CGroupBonding *cgroup_bondings,
 916                pid_t *ret) {
 917
 918         pid_t pid;
 919         int r;
 920         char *line;
 921         int socket_fd;
 922
 923         assert(command);
 924         assert(context);
 925         assert(ret);
 926         assert(fds || n_fds <= 0);
 927
 928         if (context->std_input == EXEC_INPUT_SOCKET ||
 929             context->std_output == EXEC_OUTPUT_SOCKET ||
 930             context->std_error == EXEC_OUTPUT_SOCKET) {
 931
 932                 if (n_fds != 1)
 933                         return -EINVAL;
 934
 935                 socket_fd = fds[0];
 936
 937                 fds = NULL;
 938                 n_fds = 0;
 939         } else
 940                 socket_fd = -1;
 941
 942         if (!argv)
 943                 argv = command->argv;
 944
 945         if (!(line = exec_command_line(argv)))
 946                 return -ENOMEM;
 947
 948         log_debug("About to execute: %s", line);
 949         free(line);
 950
 951         if (cgroup_bondings)
 952                 if ((r = cgroup_bonding_realize_list(cgroup_bondings)))
 953                         return r;
 954
 955         if ((pid = fork()) < 0)
 956                 return -errno;
 957
 958         if (pid == 0) {
 959                 int i;
 960                 sigset_t ss;
 961                 const char *username = NULL, *home = NULL;
 962                 uid_t uid = (uid_t) -1;
 963                 gid_t gid = (gid_t) -1;
 964                 char **our_env = NULL, **pam_env = NULL, **final_env = NULL, **final_argv = NULL;
 965                 unsigned n_env = 0;
 966                 int saved_stdout = -1, saved_stdin = -1;
 967                 bool keep_stdout = false, keep_stdin = false;
 968
 969                 /* child */
 970
 971                 /* This string must fit in 10 chars (i.e. the length
 972                  * of "/sbin/init") */
 973                 rename_process("sd:exec");
 974
 975                 /* We reset exactly these signals, since they are the
 976                  * only ones we set to SIG_IGN in the main daemon. All
 977                  * others we leave untouched because we set them to
 978                  * SIG_DFL or a valid handler initially, both of which
 979                  * will be demoted to SIG_DFL. */
 980                 default_signals(SIGNALS_CRASH_HANDLER,
 981                                 SIGNALS_IGNORE, -1);
 982
 983                 if (sigemptyset(&ss) < 0 ||
 984                     sigprocmask(SIG_SETMASK, &ss, NULL) < 0) {
 985                         r = EXIT_SIGNAL_MASK;
 986                         goto fail;
 987                 }
 988
 989                 /* Close sockets very early to make sure we don't
 990                  * block init reexecution because it cannot bind its
 991                  * sockets */
 992                 if (close_all_fds(socket_fd >= 0 ? &socket_fd : fds,
 993                                   socket_fd >= 0 ? 1 : n_fds) < 0) {
 994                         r = EXIT_FDS;
 995                         goto fail;
 996                 }
 997
 998                 if (!context->same_pgrp)
 999                         if (setsid() < 0) {
1000                                 r = EXIT_SETSID;
1001                                 goto fail;
1002                         }
1003
1004                 if (context->tcpwrap_name) {
1005                         if (socket_fd >= 0)
1006                                 if (!socket_tcpwrap(socket_fd, context->tcpwrap_name)) {
1007                                         r = EXIT_TCPWRAP;
1008                                         goto fail;
1009                                 }
1010
1011                         for (i = 0; i < (int) n_fds; i++) {
1012                                 if (!socket_tcpwrap(fds[i], context->tcpwrap_name)) {
1013                                         r = EXIT_TCPWRAP;
1014                                         goto fail;
1015                                 }
1016                         }
1017                 }
1018
1019                 /* We skip the confirmation step if we shall not apply the TTY */
1020                 if (confirm_spawn &&
1021                     (!is_terminal_input(context->std_input) || apply_tty_stdin)) {
1022                         char response;
1023
1024                         /* Set up terminal for the question */
1025                         if ((r = setup_confirm_stdio(context,
1026                                                      &saved_stdin, &saved_stdout)))
1027                                 goto fail;
1028
1029                         /* Now ask the question. */
1030                         if (!(line = exec_command_line(argv))) {
1031                                 r = EXIT_MEMORY;
1032                                 goto fail;
1033                         }
1034
1035                         r = ask(&response, "yns", "Execute %s? [Yes, No, Skip] ", line);
1036                         free(line);
1037
1038                         if (r < 0 || response == 'n') {
1039                                 r = EXIT_CONFIRM;
1040                                 goto fail;
1041                         } else if (response == 's') {
1042                                 r = 0;
1043                                 goto fail;
1044                         }
1045
1046                         /* Release terminal for the question */
1047                         if ((r = restore_confirm_stdio(context,
1048                                                        &saved_stdin, &saved_stdout,
1049                                                        &keep_stdin, &keep_stdout)))
1050                                 goto fail;
1051                 }
1052
1053                 /* If a socket is connected to STDIN/STDOUT/STDERR, we
1054                  * must sure to drop O_NONBLOCK */
1055                 if (socket_fd >= 0)
1056                         fd_nonblock(socket_fd, false);
1057
1058                 if (!keep_stdin)
1059                         if (setup_input(context, socket_fd, apply_tty_stdin) < 0) {
1060                                 r = EXIT_STDIN;
1061                                 goto fail;
1062                         }
1063
1064                 if (!keep_stdout)
1065                         if (setup_output(context, socket_fd, file_name_from_path(command->path), apply_tty_stdin) < 0) {
1066                                 r = EXIT_STDOUT;
1067                                 goto fail;
1068                         }
1069
1070                 if (setup_error(context, socket_fd, file_name_from_path(command->path), apply_tty_stdin) < 0) {
1071                         r = EXIT_STDERR;
1072                         goto fail;
1073                 }
1074
1075                 if (cgroup_bondings)
1076                         if (cgroup_bonding_install_list(cgroup_bondings, 0) < 0) {
1077                                 r = EXIT_CGROUP;
1078                                 goto fail;
1079                         }
1080
1081                 if (context->oom_score_adjust_set) {
1082                         char t[16];
1083
1084                         snprintf(t, sizeof(t), "%i", context->oom_score_adjust);
1085                         char_array_0(t);
1086
1087                         if (write_one_line_file("/proc/self/oom_score_adj", t) < 0) {
1088                                 /* Compatibility with Linux <= 2.6.35 */
1089
1090                                 int adj;
1091
1092                                 adj = (context->oom_score_adjust * -OOM_DISABLE) / OOM_SCORE_ADJ_MAX;
1093                                 adj = CLAMP(adj, OOM_DISABLE, OOM_ADJUST_MAX);
1094
1095                                 snprintf(t, sizeof(t), "%i", adj);
1096                                 char_array_0(t);
1097
1098                                 if (write_one_line_file("/proc/self/oom_adj", t) < 0) {
1099                                         r = EXIT_OOM_ADJUST;
1100                                         goto fail;
1101                                 }
1102                         }
1103                 }
1104
1105                 if (context->nice_set)
1106                         if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {
1107                                 r = EXIT_NICE;
1108                                 goto fail;
1109                         }
1110
1111                 if (context->cpu_sched_set) {
1112                         struct sched_param param;
1113
1114                         zero(param);
1115                         param.sched_priority = context->cpu_sched_priority;
1116
1117                         if (sched_setscheduler(0, context->cpu_sched_policy |
1118                                                (context->cpu_sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0), &param) < 0) {
1119                                 r = EXIT_SETSCHEDULER;
1120                                 goto fail;
1121                         }
1122                 }
1123
1124                 if (context->cpuset)
1125                         if (sched_setaffinity(0, CPU_ALLOC_SIZE(context->cpuset_ncpus), context->cpuset) < 0) {
1126                                 r = EXIT_CPUAFFINITY;
1127                                 goto fail;
1128                         }
1129
1130                 if (context->ioprio_set)
1131                         if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {
1132                                 r = EXIT_IOPRIO;
1133                                 goto fail;
1134                         }
1135
1136                 if (context->timer_slack_nsec_set)
1137                         if (prctl(PR_SET_TIMERSLACK, context->timer_slack_nsec) < 0) {
1138                                 r = EXIT_TIMERSLACK;
1139                                 goto fail;
1140                         }
1141
1142                 if (context->utmp_id)
1143                         utmp_put_init_process(0, context->utmp_id, getpid(), getsid(0), context->tty_path);
1144
1145                 if (context->user) {
1146                         username = context->user;
1147                         if (get_user_creds(&username, &uid, &gid, &home) < 0) {
1148                                 r = EXIT_USER;
1149                                 goto fail;
1150                         }
1151
1152                         if (is_terminal_input(context->std_input))
1153                                 if (chown_terminal(STDIN_FILENO, uid) < 0) {
1154                                         r = EXIT_STDIN;
1155                                         goto fail;
1156                                 }
1157                 }
1158
1159 #ifdef HAVE_PAM
1160                 if (context->pam_name && username) {
1161                         if (setup_pam(context->pam_name, username, context->tty_path, &pam_env, fds, n_fds) < 0) {
1162                                 r = EXIT_PAM;
1163                                 goto fail;
1164                         }
1165                 }
1166 #endif
1167
1168                 if (apply_permissions)
1169                         if (enforce_groups(context, username, uid) < 0) {
1170                                 r = EXIT_GROUP;
1171                                 goto fail;
1172                         }
1173
1174                 umask(context->umask);
1175
1176                 if (strv_length(context->read_write_dirs) > 0 ||
1177                     strv_length(context->read_only_dirs) > 0 ||
1178                     strv_length(context->inaccessible_dirs) > 0 ||
1179                     context->mount_flags != MS_SHARED ||
1180                     context->private_tmp)
1181                         if ((r = setup_namespace(
1182                                              context->read_write_dirs,
1183                                              context->read_only_dirs,
1184                                              context->inaccessible_dirs,
1185                                              context->private_tmp,
1186                                              context->mount_flags)) < 0)
1187                                 goto fail;
1188
1189                 if (apply_chroot) {
1190                         if (context->root_directory)
1191                                 if (chroot(context->root_directory) < 0) {
1192                                         r = EXIT_CHROOT;
1193                                         goto fail;
1194                                 }
1195
1196                         if (chdir(context->working_directory ? context->working_directory : "/") < 0) {
1197                                 r = EXIT_CHDIR;
1198                                 goto fail;
1199                         }
1200                 } else {
1201
1202                         char *d;
1203
1204                         if (asprintf(&d, "%s/%s",
1205                                      context->root_directory ? context->root_directory : "",
1206                                      context->working_directory ? context->working_directory : "") < 0) {
1207                                 r = EXIT_MEMORY;
1208                                 goto fail;
1209                         }
1210
1211                         if (chdir(d) < 0) {
1212                                 free(d);
1213                                 r = EXIT_CHDIR;
1214                                 goto fail;
1215                         }
1216
1217                         free(d);
1218                 }
1219
1220                 /* We repeat the fd closing here, to make sure that
1221                  * nothing is leaked from the PAM modules */
1222                 if (close_all_fds(fds, n_fds) < 0 ||
1223                     shift_fds(fds, n_fds) < 0 ||
1224                     flags_fds(fds, n_fds, context->non_blocking) < 0) {
1225                         r = EXIT_FDS;
1226                         goto fail;
1227                 }
1228
1229                 if (apply_permissions) {
1230
1231                         for (i = 0; i < RLIMIT_NLIMITS; i++) {
1232                                 if (!context->rlimit[i])
1233                                         continue;
1234
1235                                 if (setrlimit(i, context->rlimit[i]) < 0) {
1236                                         r = EXIT_LIMITS;
1237                                         goto fail;
1238                                 }
1239                         }
1240
1241                         if (context->user)
1242                                 if (enforce_user(context, uid) < 0) {
1243                                         r = EXIT_USER;
1244                                         goto fail;
1245                                 }
1246
1247                         /* PR_GET_SECUREBITS is not privileged, while
1248                          * PR_SET_SECUREBITS is. So to suppress
1249                          * potential EPERMs we'll try not to call
1250                          * PR_SET_SECUREBITS unless necessary. */
1251                         if (prctl(PR_GET_SECUREBITS) != context->secure_bits)
1252                                 if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) {
1253                                         r = EXIT_SECUREBITS;
1254                                         goto fail;
1255                                 }
1256
1257                         if (context->capabilities)
1258                                 if (cap_set_proc(context->capabilities) < 0) {
1259                                         r = EXIT_CAPABILITIES;
1260                                         goto fail;
1261                                 }
1262                 }
1263
1264                 if (!(our_env = new0(char*, 7))) {
1265                         r = EXIT_MEMORY;
1266                         goto fail;
1267                 }
1268
1269                 if (n_fds > 0)
1270                         if (asprintf(our_env + n_env++, "LISTEN_PID=%lu", (unsigned long) getpid()) < 0 ||
1271                             asprintf(our_env + n_env++, "LISTEN_FDS=%u", n_fds) < 0) {
1272                                 r = EXIT_MEMORY;
1273                                 goto fail;
1274                         }
1275
1276                 if (home)
1277                         if (asprintf(our_env + n_env++, "HOME=%s", home) < 0) {
1278                                 r = EXIT_MEMORY;
1279                                 goto fail;
1280                         }
1281
1282                 if (username)
1283                         if (asprintf(our_env + n_env++, "LOGNAME=%s", username) < 0 ||
1284                             asprintf(our_env + n_env++, "USER=%s", username) < 0) {
1285                                 r = EXIT_MEMORY;
1286                                 goto fail;
1287                         }
1288
1289                 if (is_terminal_input(context->std_input) ||
1290                     context->std_output == EXEC_OUTPUT_TTY ||
1291                     context->std_error == EXEC_OUTPUT_TTY)
1292                         if (!(our_env[n_env++] = strdup(default_term_for_tty(tty_path(context))))) {
1293                                 r = EXIT_MEMORY;
1294                                 goto fail;
1295                         }
1296
1297                 assert(n_env <= 7);
1298
1299                 if (!(final_env = strv_env_merge(
1300                                       4,
1301                                       environment,
1302                                       our_env,
1303                                       context->environment,
1304                                       pam_env,
1305                                       NULL))) {
1306                         r = EXIT_MEMORY;
1307                         goto fail;
1308                 }
1309
1310                 if (!(final_argv = replace_env_argv(argv, final_env))) {
1311                         r = EXIT_MEMORY;
1312                         goto fail;
1313                 }
1314
1315                 final_env = strv_env_clean(final_env);
1316
1317                 execve(command->path, final_argv, final_env);
1318                 r = EXIT_EXEC;
1319
1320         fail:
1321                 strv_free(our_env);
1322                 strv_free(final_env);
1323                 strv_free(pam_env);
1324                 strv_free(final_argv);
1325
1326                 if (saved_stdin >= 0)
1327                         close_nointr_nofail(saved_stdin);
1328
1329                 if (saved_stdout >= 0)
1330                         close_nointr_nofail(saved_stdout);
1331
1332                 _exit(r);
1333         }
1334
1335         /* We add the new process to the cgroup both in the child (so
1336          * that we can be sure that no user code is ever executed
1337          * outside of the cgroup) and in the parent (so that we can be
1338          * sure that when we kill the cgroup the process will be
1339          * killed too). */
1340         if (cgroup_bondings)
1341                 cgroup_bonding_install_list(cgroup_bondings, pid);
1342
1343         log_debug("Forked %s as %lu", command->path, (unsigned long) pid);
1344
1345         exec_status_start(&command->exec_status, pid);
1346
1347         *ret = pid;
1348         return 0;
1349 }
1350
1351 void exec_context_init(ExecContext *c) {
1352         assert(c);
1353
1354         c->umask = 0002;
1355         c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);
1356         c->cpu_sched_policy = SCHED_OTHER;
1357         c->syslog_priority = LOG_DAEMON|LOG_INFO;
1358         c->syslog_level_prefix = true;
1359         c->mount_flags = MS_SHARED;
1360         c->kill_signal = SIGTERM;
1361         c->send_sigkill = true;
1362 }
1363
1364 void exec_context_done(ExecContext *c) {
1365         unsigned l;
1366
1367         assert(c);
1368
1369         strv_free(c->environment);
1370         c->environment = NULL;
1371
1372         for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {
1373                 free(c->rlimit[l]);
1374                 c->rlimit[l] = NULL;
1375         }
1376
1377         free(c->working_directory);
1378         c->working_directory = NULL;
1379         free(c->root_directory);
1380         c->root_directory = NULL;
1381
1382         free(c->tty_path);
1383         c->tty_path = NULL;
1384
1385         free(c->tcpwrap_name);
1386         c->tcpwrap_name = NULL;
1387
1388         free(c->syslog_identifier);
1389         c->syslog_identifier = NULL;
1390
1391         free(c->user);
1392         c->user = NULL;
1393
1394         free(c->group);
1395         c->group = NULL;
1396
1397         strv_free(c->supplementary_groups);
1398         c->supplementary_groups = NULL;
1399
1400         free(c->pam_name);
1401         c->pam_name = NULL;
1402
1403         if (c->capabilities) {
1404                 cap_free(c->capabilities);
1405                 c->capabilities = NULL;
1406         }
1407
1408         strv_free(c->read_only_dirs);
1409         c->read_only_dirs = NULL;
1410
1411         strv_free(c->read_write_dirs);
1412         c->read_write_dirs = NULL;
1413
1414         strv_free(c->inaccessible_dirs);
1415         c->inaccessible_dirs = NULL;
1416
1417         if (c->cpuset)
1418                 CPU_FREE(c->cpuset);
1419
1420         free(c->utmp_id);
1421         c->utmp_id = NULL;
1422 }
1423
1424 void exec_command_done(ExecCommand *c) {
1425         assert(c);
1426
1427         free(c->path);
1428         c->path = NULL;
1429
1430         strv_free(c->argv);
1431         c->argv = NULL;
1432 }
1433
1434 void exec_command_done_array(ExecCommand *c, unsigned n) {
1435         unsigned i;
1436
1437         for (i = 0; i < n; i++)
1438                 exec_command_done(c+i);
1439 }
1440
1441 void exec_command_free_list(ExecCommand *c) {
1442         ExecCommand *i;
1443
1444         while ((i = c)) {
1445                 LIST_REMOVE(ExecCommand, command, c, i);
1446                 exec_command_done(i);
1447                 free(i);
1448         }
1449 }
1450
1451 void exec_command_free_array(ExecCommand **c, unsigned n) {
1452         unsigned i;
1453
1454         for (i = 0; i < n; i++) {
1455                 exec_command_free_list(c[i]);
1456                 c[i] = NULL;
1457         }
1458 }
1459
1460 static void strv_fprintf(FILE *f, char **l) {
1461         char **g;
1462
1463         assert(f);
1464
1465         STRV_FOREACH(g, l)
1466                 fprintf(f, " %s", *g);
1467 }
1468
1469 void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
1470         char ** e;
1471         unsigned i;
1472
1473         assert(c);
1474         assert(f);
1475
1476         if (!prefix)
1477                 prefix = "";
1478
1479         fprintf(f,
1480                 "%sUMask: %04o\n"
1481                 "%sWorkingDirectory: %s\n"
1482                 "%sRootDirectory: %s\n"
1483                 "%sNonBlocking: %s\n"
1484                 "%sPrivateTmp: %s\n",
1485                 prefix, c->umask,
1486                 prefix, c->working_directory ? c->working_directory : "/",
1487                 prefix, c->root_directory ? c->root_directory : "/",
1488                 prefix, yes_no(c->non_blocking),
1489                 prefix, yes_no(c->private_tmp));
1490
1491         if (c->environment)
1492                 for (e = c->environment; *e; e++)
1493                         fprintf(f, "%sEnvironment: %s\n", prefix, *e);
1494
1495         if (c->tcpwrap_name)
1496                 fprintf(f,
1497                         "%sTCPWrapName: %s\n",
1498                         prefix, c->tcpwrap_name);
1499
1500         if (c->nice_set)
1501                 fprintf(f,
1502                         "%sNice: %i\n",
1503                         prefix, c->nice);
1504
1505         if (c->oom_score_adjust_set)
1506                 fprintf(f,
1507                         "%sOOMScoreAdjust: %i\n",
1508                         prefix, c->oom_score_adjust);
1509
1510         for (i = 0; i < RLIM_NLIMITS; i++)
1511                 if (c->rlimit[i])
1512                         fprintf(f, "%s%s: %llu\n", prefix, rlimit_to_string(i), (unsigned long long) c->rlimit[i]->rlim_max);
1513
1514         if (c->ioprio_set)
1515                 fprintf(f,
1516                         "%sIOSchedulingClass: %s\n"
1517                         "%sIOPriority: %i\n",
1518                         prefix, ioprio_class_to_string(IOPRIO_PRIO_CLASS(c->ioprio)),
1519                         prefix, (int) IOPRIO_PRIO_DATA(c->ioprio));
1520
1521         if (c->cpu_sched_set)
1522                 fprintf(f,
1523                         "%sCPUSchedulingPolicy: %s\n"
1524                         "%sCPUSchedulingPriority: %i\n"
1525                         "%sCPUSchedulingResetOnFork: %s\n",
1526                         prefix, sched_policy_to_string(c->cpu_sched_policy),
1527                         prefix, c->cpu_sched_priority,
1528                         prefix, yes_no(c->cpu_sched_reset_on_fork));
1529
1530         if (c->cpuset) {
1531                 fprintf(f, "%sCPUAffinity:", prefix);
1532                 for (i = 0; i < c->cpuset_ncpus; i++)
1533                         if (CPU_ISSET_S(i, CPU_ALLOC_SIZE(c->cpuset_ncpus), c->cpuset))
1534                                 fprintf(f, " %i", i);
1535                 fputs("\n", f);
1536         }
1537
1538         if (c->timer_slack_nsec_set)
1539                 fprintf(f, "%sTimerSlackNSec: %lu\n", prefix, c->timer_slack_nsec);
1540
1541         fprintf(f,
1542                 "%sStandardInput: %s\n"
1543                 "%sStandardOutput: %s\n"
1544                 "%sStandardError: %s\n",
1545                 prefix, exec_input_to_string(c->std_input),
1546                 prefix, exec_output_to_string(c->std_output),
1547                 prefix, exec_output_to_string(c->std_error));
1548
1549         if (c->tty_path)
1550                 fprintf(f,
1551                         "%sTTYPath: %s\n",
1552                         prefix, c->tty_path);
1553
1554         if (c->std_output == EXEC_OUTPUT_SYSLOG || c->std_output == EXEC_OUTPUT_KMSG ||
1555             c->std_output == EXEC_OUTPUT_SYSLOG_AND_CONSOLE || c->std_output == EXEC_OUTPUT_KMSG_AND_CONSOLE ||
1556             c->std_error == EXEC_OUTPUT_SYSLOG || c->std_error == EXEC_OUTPUT_KMSG ||
1557             c->std_error == EXEC_OUTPUT_SYSLOG_AND_CONSOLE || c->std_error == EXEC_OUTPUT_KMSG_AND_CONSOLE)
1558                 fprintf(f,
1559                         "%sSyslogFacility: %s\n"
1560                         "%sSyslogLevel: %s\n",
1561                         prefix, log_facility_to_string(LOG_FAC(c->syslog_priority)),
1562                         prefix, log_level_to_string(LOG_PRI(c->syslog_priority)));
1563
1564         if (c->capabilities) {
1565                 char *t;
1566                 if ((t = cap_to_text(c->capabilities, NULL))) {
1567                         fprintf(f, "%sCapabilities: %s\n",
1568                                 prefix, t);
1569                         cap_free(t);
1570                 }
1571         }
1572
1573         if (c->secure_bits)
1574                 fprintf(f, "%sSecure Bits:%s%s%s%s%s%s\n",
1575                         prefix,
1576                         (c->secure_bits & SECURE_KEEP_CAPS) ? " keep-caps" : "",
1577                         (c->secure_bits & SECURE_KEEP_CAPS_LOCKED) ? " keep-caps-locked" : "",
1578                         (c->secure_bits & SECURE_NO_SETUID_FIXUP) ? " no-setuid-fixup" : "",
1579                         (c->secure_bits & SECURE_NO_SETUID_FIXUP_LOCKED) ? " no-setuid-fixup-locked" : "",
1580                         (c->secure_bits & SECURE_NOROOT) ? " noroot" : "",
1581                         (c->secure_bits & SECURE_NOROOT_LOCKED) ? "noroot-locked" : "");
1582
1583         if (c->capability_bounding_set_drop) {
1584                 fprintf(f, "%sCapabilityBoundingSetDrop:", prefix);
1585
1586                 for (i = 0; i <= CAP_LAST_CAP; i++)
1587                         if (c->capability_bounding_set_drop & (1 << i)) {
1588                                 char *t;
1589
1590                                 if ((t = cap_to_name(i))) {
1591                                         fprintf(f, " %s", t);
1592                                         free(t);
1593                                 }
1594                         }
1595
1596                 fputs("\n", f);
1597         }
1598
1599         if (c->user)
1600                 fprintf(f, "%sUser: %s\n", prefix, c->user);
1601         if (c->group)
1602                 fprintf(f, "%sGroup: %s\n", prefix, c->group);
1603
1604         if (strv_length(c->supplementary_groups) > 0) {
1605                 fprintf(f, "%sSupplementaryGroups:", prefix);
1606                 strv_fprintf(f, c->supplementary_groups);
1607                 fputs("\n", f);
1608         }
1609
1610         if (c->pam_name)
1611                 fprintf(f, "%sPAMName: %s\n", prefix, c->pam_name);
1612
1613         if (strv_length(c->read_write_dirs) > 0) {
1614                 fprintf(f, "%sReadWriteDirs:", prefix);
1615                 strv_fprintf(f, c->read_write_dirs);
1616                 fputs("\n", f);
1617         }
1618
1619         if (strv_length(c->read_only_dirs) > 0) {
1620                 fprintf(f, "%sReadOnlyDirs:", prefix);
1621                 strv_fprintf(f, c->read_only_dirs);
1622                 fputs("\n", f);
1623         }
1624
1625         if (strv_length(c->inaccessible_dirs) > 0) {
1626                 fprintf(f, "%sInaccessibleDirs:", prefix);
1627                 strv_fprintf(f, c->inaccessible_dirs);
1628                 fputs("\n", f);
1629         }
1630
1631         fprintf(f,
1632                 "%sKillMode: %s\n"
1633                 "%sKillSignal: SIG%s\n"
1634                 "%sSendSIGKILL: %s\n",
1635                 prefix, kill_mode_to_string(c->kill_mode),
1636                 prefix, signal_to_string(c->kill_signal),
1637                 prefix, yes_no(c->send_sigkill));
1638
1639         if (c->utmp_id)
1640                 fprintf(f,
1641                         "%sUtmpIdentifier: %s\n",
1642                         prefix, c->utmp_id);
1643 }
1644
1645 void exec_status_start(ExecStatus *s, pid_t pid) {
1646         assert(s);
1647
1648         zero(*s);
1649         s->pid = pid;
1650         dual_timestamp_get(&s->start_timestamp);
1651 }
1652
1653 void exec_status_exit(ExecStatus *s, pid_t pid, int code, int status, const char *utmp_id) {
1654         assert(s);
1655
1656         if ((s->pid && s->pid != pid) ||
1657             !s->start_timestamp.realtime <= 0)
1658                 zero(*s);
1659
1660         s->pid = pid;
1661         dual_timestamp_get(&s->exit_timestamp);
1662
1663         s->code = code;
1664         s->status = status;
1665
1666         if (utmp_id)
1667                 utmp_put_dead_process(utmp_id, pid, code, status);
1668 }
1669
1670 void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix) {
1671         char buf[FORMAT_TIMESTAMP_MAX];
1672
1673         assert(s);
1674         assert(f);
1675
1676         if (!prefix)
1677                 prefix = "";
1678
1679         if (s->pid <= 0)
1680                 return;
1681
1682         fprintf(f,
1683                 "%sPID: %lu\n",
1684                 prefix, (unsigned long) s->pid);
1685
1686         if (s->start_timestamp.realtime > 0)
1687                 fprintf(f,
1688                         "%sStart Timestamp: %s\n",
1689                         prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp.realtime));
1690
1691         if (s->exit_timestamp.realtime > 0)
1692                 fprintf(f,
1693                         "%sExit Timestamp: %s\n"
1694                         "%sExit Code: %s\n"
1695                         "%sExit Status: %i\n",
1696                         prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp.realtime),
1697                         prefix, sigchld_code_to_string(s->code),
1698                         prefix, s->status);
1699 }
1700
1701 char *exec_command_line(char **argv) {
1702         size_t k;
1703         char *n, *p, **a;
1704         bool first = true;
1705
1706         assert(argv);
1707
1708         k = 1;
1709         STRV_FOREACH(a, argv)
1710                 k += strlen(*a)+3;
1711
1712         if (!(n = new(char, k)))
1713                 return NULL;
1714
1715         p = n;
1716         STRV_FOREACH(a, argv) {
1717
1718                 if (!first)
1719                         *(p++) = ' ';
1720                 else
1721                         first = false;
1722
1723                 if (strpbrk(*a, WHITESPACE)) {
1724                         *(p++) = '\'';
1725                         p = stpcpy(p, *a);
1726                         *(p++) = '\'';
1727                 } else
1728                         p = stpcpy(p, *a);
1729
1730         }
1731
1732         *p = 0;
1733
1734         /* FIXME: this doesn't really handle arguments that have
1735          * spaces and ticks in them */
1736
1737         return n;
1738 }
1739
1740 void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {
1741         char *p2;
1742         const char *prefix2;
1743
1744         char *cmd;
1745
1746         assert(c);
1747         assert(f);
1748
1749         if (!prefix)
1750                 prefix = "";
1751         p2 = strappend(prefix, "\t");
1752         prefix2 = p2 ? p2 : prefix;
1753
1754         cmd = exec_command_line(c->argv);
1755
1756         fprintf(f,
1757                 "%sCommand Line: %s\n",
1758                 prefix, cmd ? cmd : strerror(ENOMEM));
1759
1760         free(cmd);
1761
1762         exec_status_dump(&c->exec_status, f, prefix2);
1763
1764         free(p2);
1765 }
1766
1767 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {
1768         assert(f);
1769
1770         if (!prefix)
1771                 prefix = "";
1772
1773         LIST_FOREACH(command, c, c)
1774                 exec_command_dump(c, f, prefix);
1775 }
1776
1777 void exec_command_append_list(ExecCommand **l, ExecCommand *e) {
1778         ExecCommand *end;
1779
1780         assert(l);
1781         assert(e);
1782
1783         if (*l) {
1784                 /* It's kind of important, that we keep the order here */
1785                 LIST_FIND_TAIL(ExecCommand, command, *l, end);
1786                 LIST_INSERT_AFTER(ExecCommand, command, *l, end, e);
1787         } else
1788               *l = e;
1789 }
1790
1791 int exec_command_set(ExecCommand *c, const char *path, ...) {
1792         va_list ap;
1793         char **l, *p;
1794
1795         assert(c);
1796         assert(path);
1797
1798         va_start(ap, path);
1799         l = strv_new_ap(path, ap);
1800         va_end(ap);
1801
1802         if (!l)
1803                 return -ENOMEM;
1804
1805         if (!(p = strdup(path))) {
1806                 strv_free(l);
1807                 return -ENOMEM;
1808         }
1809
1810         free(c->path);
1811         c->path = p;
1812
1813         strv_free(c->argv);
1814         c->argv = l;
1815
1816         return 0;
1817 }
1818
1819 static const char* const exec_input_table[_EXEC_INPUT_MAX] = {
1820         [EXEC_INPUT_NULL] = "null",
1821         [EXEC_INPUT_TTY] = "tty",
1822         [EXEC_INPUT_TTY_FORCE] = "tty-force",
1823         [EXEC_INPUT_TTY_FAIL] = "tty-fail",
1824         [EXEC_INPUT_SOCKET] = "socket"
1825 };
1826
1827 DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);
1828
1829 static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
1830         [EXEC_OUTPUT_INHERIT] = "inherit",
1831         [EXEC_OUTPUT_NULL] = "null",
1832         [EXEC_OUTPUT_TTY] = "tty",
1833         [EXEC_OUTPUT_SYSLOG] = "syslog",
1834         [EXEC_OUTPUT_SYSLOG_AND_CONSOLE] = "syslog+console",
1835         [EXEC_OUTPUT_KMSG] = "kmsg",
1836         [EXEC_OUTPUT_KMSG_AND_CONSOLE] = "kmsg+console",
1837         [EXEC_OUTPUT_SOCKET] = "socket"
1838 };
1839
1840 DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);
1841
1842 static const char* const kill_mode_table[_KILL_MODE_MAX] = {
1843         [KILL_CONTROL_GROUP] = "control-group",
1844         [KILL_PROCESS_GROUP] = "process-group",
1845         [KILL_PROCESS] = "process",
1846         [KILL_NONE] = "none"
1847 };
1848
1849 DEFINE_STRING_TABLE_LOOKUP(kill_mode, KillMode);
1850
1851 static const char* const kill_who_table[_KILL_WHO_MAX] = {
1852         [KILL_MAIN] = "main",
1853         [KILL_CONTROL] = "control",
1854         [KILL_ALL] = "all"
1855 };
1856
1857 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);