scheduler/process.c

   1 /*
   2  * Process management routines for the CUPS scheduler.
   3  *
   4  * Copyright 2007-2017 by Apple Inc.
   5  * Copyright 1997-2007 by Easy Software Products, all rights reserved.
   6  *
   7  * Licensed under Apache License v2.0.  See the file "LICENSE" for more information.
   8  */
   9
  10 /*
  11  * Include necessary headers...
  12  */
  13
  14 #include "cupsd.h"
  15 #include <grp.h>
  16 #ifdef __APPLE__
  17 #  include <libgen.h>
  18 #endif /* __APPLE__ */
  19 #ifdef HAVE_POSIX_SPAWN
  20 #  include <spawn.h>
  21 extern char **environ;
  22 /* Don't use posix_spawn on systems with bugs in their implementations... */
  23 #  if defined(OpenBSD) && OpenBSD < 201505
  24 #    define USE_POSIX_SPAWN 0
  25 #  elif defined(__UCLIBC__) && __UCLIBC_MAJOR__ == 1 && __UCLIBC_MINOR__ == 0 && __UCLIBC_SUBLEVEL__ < 27
  26 #    define USE_POSIX_SPAWN 0
  27 #  elif defined(__UCLIBC__) && __UCLIBC_MAJOR__ < 1
  28 #    define USE_POSIX_SPAWN 0
  29 #  else /* All other platforms */
  30 #    define USE_POSIX_SPAWN 1
  31 #  endif /* ... */
  32 #else
  33 #  define USE_POSIX_SPAWN 0
  34 #endif /* HAVE_POSIX_SPAWN */
  35
  36
  37 /*
  38  * Process structure...
  39  */
  40
  41 typedef struct
  42 {
  43   int   pid,                            /* Process ID */
  44         job_id;                         /* Job associated with process */
  45   char  name[1];                        /* Name of process */
  46 } cupsd_proc_t;
  47
  48
  49 /*
  50  * Local globals...
  51  */
  52
  53 static cups_array_t     *process_array = NULL;
  54
  55
  56 /*
  57  * Local functions...
  58  */
  59
  60 static int      compare_procs(cupsd_proc_t *a, cupsd_proc_t *b);
  61 #ifdef HAVE_SANDBOX_H
  62 static char     *cupsd_requote(char *dst, const char *src, size_t dstsize);
  63 #endif /* HAVE_SANDBOX_H */
  64
  65
  66 /*
  67  * 'cupsdCreateProfile()' - Create an execution profile for a subprocess.
  68  */
  69
  70 void *                                  /* O - Profile or NULL on error */
  71 cupsdCreateProfile(int job_id,          /* I - Job ID or 0 for none */
  72                    int allow_networking)/* I - Allow networking off machine? */
  73 {
  74 #ifdef HAVE_SANDBOX_H
  75   cups_file_t           *fp;            /* File pointer */
  76   char                  profile[1024],  /* File containing the profile */
  77                         bin[1024],      /* Quoted ServerBin */
  78                         cache[1024],    /* Quoted CacheDir */
  79                         domain[1024],   /* Domain socket, if any */
  80                         request[1024],  /* Quoted RequestRoot */
  81                         root[1024],     /* Quoted ServerRoot */
  82                         state[1024],    /* Quoted StateDir */
  83                         temp[1024];     /* Quoted TempDir */
  84   const char            *nodebug;       /* " (with no-log)" for no debug */
  85   cupsd_listener_t      *lis;           /* Current listening socket */
  86
  87
  88   if (!UseSandboxing || Sandboxing == CUPSD_SANDBOXING_OFF)
  89   {
  90    /*
  91     * Only use sandbox profiles as root...
  92     */
  93
  94     cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdCreateProfile(job_id=%d, allow_networking=%d) = NULL", job_id, allow_networking);
  95
  96     return (NULL);
  97   }
  98
  99   if ((fp = cupsTempFile2(profile, sizeof(profile))) == NULL)
 100   {
 101    /*
 102     * This should never happen, and is fatal when sandboxing is enabled.
 103     */
 104
 105     cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdCreateProfile(job_id=%d, allow_networking=%d) = NULL", job_id, allow_networking);
 106     cupsdLogMessage(CUPSD_LOG_EMERG, "Unable to create security profile: %s", strerror(errno));
 107     kill(getpid(), SIGTERM);
 108     return (NULL);
 109   }
 110
 111   fchown(cupsFileNumber(fp), RunUser, Group);
 112   fchmod(cupsFileNumber(fp), 0640);
 113
 114   cupsd_requote(bin, ServerBin, sizeof(bin));
 115   cupsd_requote(cache, CacheDir, sizeof(cache));
 116   cupsd_requote(request, RequestRoot, sizeof(request));
 117   cupsd_requote(root, ServerRoot, sizeof(root));
 118   cupsd_requote(state, StateDir, sizeof(state));
 119   cupsd_requote(temp, TempDir, sizeof(temp));
 120
 121   nodebug = LogLevel < CUPSD_LOG_DEBUG ? " (with no-log)" : "";
 122
 123   cupsFilePuts(fp, "(version 1)\n");
 124   if (Sandboxing == CUPSD_SANDBOXING_STRICT)
 125     cupsFilePuts(fp, "(deny default)\n");
 126   else
 127     cupsFilePuts(fp, "(allow default)\n");
 128   if (LogLevel >= CUPSD_LOG_DEBUG)
 129     cupsFilePuts(fp, "(debug deny)\n");
 130   cupsFilePuts(fp, "(import \"system.sb\")\n");
 131   cupsFilePuts(fp, "(import \"com.apple.corefoundation.sb\")\n");
 132   cupsFilePuts(fp, "(system-network)\n");
 133   cupsFilePuts(fp, "(allow mach-per-user-lookup)\n");
 134   cupsFilePuts(fp, "(allow ipc-posix-sem)\n");
 135   cupsFilePuts(fp, "(allow ipc-posix-shm)\n");
 136   cupsFilePuts(fp, "(allow ipc-sysv-shm)\n");
 137   cupsFilePuts(fp, "(allow mach-lookup)\n");
 138   if (!RunUser)
 139     cupsFilePrintf(fp,
 140                    "(deny file-write* file-read-data file-read-metadata\n"
 141                    "  (regex"
 142                    " #\"^/Users$\""
 143                    " #\"^/Users/\""
 144                    ")%s)\n", nodebug);
 145   cupsFilePrintf(fp,
 146                  "(deny file-write*\n"
 147                  "  (regex"
 148                  " #\"^%s$\""           /* ServerRoot */
 149                  " #\"^%s/\""           /* ServerRoot/... */
 150                  " #\"^/private/etc$\""
 151                  " #\"^/private/etc/\""
 152                  " #\"^/usr/local/etc$\""
 153                  " #\"^/usr/local/etc/\""
 154                  " #\"^/Library$\""
 155                  " #\"^/Library/\""
 156                  " #\"^/System$\""
 157                  " #\"^/System/\""
 158                  ")%s)\n",
 159                  root, root, nodebug);
 160   /* Specifically allow applications to stat RequestRoot and some other system folders */
 161   cupsFilePrintf(fp,
 162                  "(allow file-read-metadata\n"
 163                  "  (regex"
 164                  " #\"^/$\""            /* / */
 165                  " #\"^/usr$\""         /* /usr */
 166                  " #\"^/Library$\""     /* /Library */
 167                  " #\"^/Library/Printers$\""    /* /Library/Printers */
 168                  " #\"^%s$\""           /* RequestRoot */
 169                  "))\n",
 170                  request);
 171   /* Read and write TempDir, CacheDir, and other common folders */
 172   cupsFilePuts(fp,
 173                "(allow file-write* file-read-data file-read-metadata\n"
 174                "  (regex"
 175                " #\"^/private/var/db/\""
 176                " #\"^/private/var/folders/\""
 177                " #\"^/private/var/lib/\""
 178                " #\"^/private/var/log/\""
 179                " #\"^/private/var/mysql/\""
 180                " #\"^/private/var/run/\""
 181                " #\"^/private/var/spool/\""
 182                " #\"^/Library/Application Support/\""
 183                " #\"^/Library/Caches/\""
 184                " #\"^/Library/Logs/\""
 185                " #\"^/Library/Preferences/\""
 186                " #\"^/Library/WebServer/\""
 187                " #\"^/Users/Shared/\""
 188                "))\n");
 189   cupsFilePrintf(fp,
 190                  "(deny file-write*\n"
 191                  "       (regex #\"^%s$\")%s)\n",
 192                  request, nodebug);
 193   cupsFilePrintf(fp,
 194                  "(deny file-write* file-read-data file-read-metadata\n"
 195                  "       (regex #\"^%s/\")%s)\n",
 196                  request, nodebug);
 197   cupsFilePrintf(fp,
 198                  "(allow file-write* file-read-data file-read-metadata\n"
 199                  "  (regex"
 200                  " #\"^%s$\""           /* TempDir */
 201                  " #\"^%s/\""           /* TempDir/... */
 202                  " #\"^%s$\""           /* CacheDir */
 203                  " #\"^%s/\""           /* CacheDir/... */
 204                  "))\n",
 205                  temp, temp, cache, cache);
 206   /* Read common folders */
 207   cupsFilePrintf(fp,
 208                  "(allow file-read-data file-read-metadata\n"
 209                  "  (regex"
 210                  " #\"^/AppleInternal$\""
 211                  " #\"^/AppleInternal/\""
 212                  " #\"^/bin$\""         /* /bin */
 213                  " #\"^/bin/\""         /* /bin/... */
 214                  " #\"^/private$\""
 215                  " #\"^/private/etc$\""
 216                  " #\"^/private/etc/\""
 217                  " #\"^/private/tmp$\""
 218                  " #\"^/private/tmp/\""
 219                  " #\"^/private/var$\""
 220                  " #\"^/private/var/db$\""
 221                  " #\"^/private/var/folders$\""
 222                  " #\"^/private/var/lib$\""
 223                  " #\"^/private/var/log$\""
 224                  " #\"^/private/var/mysql$\""
 225                  " #\"^/private/var/run$\""
 226                  " #\"^/private/var/spool$\""
 227                  " #\"^/private/var/tmp$\""
 228                  " #\"^/private/var/tmp/\""
 229                  " #\"^/usr/bin$\""     /* /usr/bin */
 230                  " #\"^/usr/bin/\""     /* /usr/bin/... */
 231                  " #\"^/usr/libexec/cups$\""    /* /usr/libexec/cups */
 232                  " #\"^/usr/libexec/cups/\""    /* /usr/libexec/cups/... */
 233                  " #\"^/usr/libexec/fax$\""     /* /usr/libexec/fax */
 234                  " #\"^/usr/libexec/fax/\""     /* /usr/libexec/fax/... */
 235                  " #\"^/usr/sbin$\""    /* /usr/sbin */
 236                  " #\"^/usr/sbin/\""    /* /usr/sbin/... */
 237                  " #\"^/Library$\""     /* /Library */
 238                  " #\"^/Library/\""     /* /Library/... */
 239                  " #\"^/System$\""      /* /System */
 240                  " #\"^/System/\""      /* /System/... */
 241                  " #\"^%s/Library$\""   /* RequestRoot/Library */
 242                  " #\"^%s/Library/\""   /* RequestRoot/Library/... */
 243                  " #\"^%s$\""           /* ServerBin */
 244                  " #\"^%s/\""           /* ServerBin/... */
 245                  " #\"^%s$\""           /* ServerRoot */
 246                  " #\"^%s/\""           /* ServerRoot/... */
 247                  " #\"^%s$\""           /* StateDir */
 248                  " #\"^%s/\""           /* StateDir/... */
 249                  "))\n",
 250                  request, request, bin, bin, root, root, state, state);
 251   if (Sandboxing == CUPSD_SANDBOXING_RELAXED)
 252   {
 253     /* Limited write access to /Library/Printers/... */
 254     cupsFilePuts(fp,
 255                  "(allow file-write*\n"
 256                  "  (regex"
 257                  " #\"^/Library/Printers/.*/\""
 258                  "))\n");
 259     cupsFilePrintf(fp,
 260                    "(deny file-write*\n"
 261                    "  (regex"
 262                    " #\"^/Library/Printers/PPDs$\""
 263                    " #\"^/Library/Printers/PPDs/\""
 264                    " #\"^/Library/Printers/PPD Plugins$\""
 265                    " #\"^/Library/Printers/PPD Plugins/\""
 266                    ")%s)\n", nodebug);
 267   }
 268   /* Allow execution of child processes as long as the programs are not in a user directory */
 269   cupsFilePuts(fp, "(allow process*)\n");
 270   cupsFilePuts(fp, "(deny process-exec (regex #\"^/Users/\"))\n");
 271   if (RunUser && getenv("CUPS_TESTROOT"))
 272   {
 273     /* Allow source directory access in "make test" environment */
 274     char        testroot[1024];         /* Root directory of test files */
 275
 276     cupsd_requote(testroot, getenv("CUPS_TESTROOT"), sizeof(testroot));
 277
 278     cupsFilePrintf(fp,
 279                    "(allow file-write* file-read-data file-read-metadata\n"
 280                    "  (regex"
 281                    " #\"^%s$\""         /* CUPS_TESTROOT */
 282                    " #\"^%s/\""         /* CUPS_TESTROOT/... */
 283                    "))\n",
 284                    testroot, testroot);
 285     cupsFilePrintf(fp,
 286                    "(allow process-exec\n"
 287                    "  (regex"
 288                    " #\"^%s/\""         /* CUPS_TESTROOT/... */
 289                    "))\n",
 290                    testroot);
 291     cupsFilePrintf(fp, "(allow sysctl*)\n");
 292   }
 293   if (job_id)
 294   {
 295     /* Allow job filters to read the current job files... */
 296     cupsFilePrintf(fp,
 297                    "(allow file-read-data file-read-metadata\n"
 298                    "       (regex #\"^%s/([ac]%05d|d%05d-[0-9][0-9][0-9])$\"))\n",
 299                    request, job_id, job_id);
 300   }
 301   else
 302   {
 303     /* Allow email notifications from notifiers... */
 304     cupsFilePuts(fp,
 305                  "(allow process-exec\n"
 306                  "  (literal \"/usr/sbin/sendmail\")\n"
 307                  "  (with no-sandbox))\n");
 308   }
 309   /* Allow access to Bluetooth, USB, and notify_post. */
 310   cupsFilePuts(fp, "(allow iokit*)\n");
 311   cupsFilePuts(fp, "(allow distributed-notification-post)\n");
 312   /* Allow outbound networking to local services */
 313   cupsFilePuts(fp, "(allow network-outbound"
 314                    "\n       (regex #\"^/private/var/run/\" #\"^/private/tmp/\" #\"^/private/var/tmp/\")");
 315   for (lis = (cupsd_listener_t *)cupsArrayFirst(Listeners);
 316        lis;
 317        lis = (cupsd_listener_t *)cupsArrayNext(Listeners))
 318   {
 319     if (httpAddrFamily(&(lis->address)) == AF_LOCAL)
 320     {
 321       httpAddrString(&(lis->address), domain, sizeof(domain));
 322       cupsFilePrintf(fp, "\n       (literal \"%s\")", domain);
 323     }
 324   }
 325   if (allow_networking)
 326   {
 327     /* Allow TCP and UDP networking off the machine... */
 328     cupsFilePuts(fp, "\n       (remote tcp))\n");
 329     cupsFilePuts(fp, "(allow network-bind)\n"); /* for LPD resvport */
 330     cupsFilePuts(fp, "(allow network*\n"
 331                      "       (local udp \"*:*\")\n"
 332                      "       (remote udp \"*:*\"))\n");
 333
 334     /* Also allow access to device files... */
 335     cupsFilePuts(fp, "(allow file-write* file-read-data file-read-metadata file-ioctl\n"
 336                      "       (regex #\"^/dev/\"))\n");
 337
 338     /* And allow kernel extensions to be loaded, e.g., SMB */
 339     cupsFilePuts(fp, "(allow system-kext-load)\n");
 340   }
 341   else
 342   {
 343     /* Only allow SNMP (UDP) and LPD (TCP) off the machine... */
 344     cupsFilePuts(fp, ")\n");
 345     cupsFilePuts(fp, "(allow network-outbound\n"
 346                      "       (remote udp \"*:161\")\n"
 347                      "       (remote tcp \"*:515\"))\n");
 348     cupsFilePuts(fp, "(allow network-inbound\n"
 349                      "       (local udp \"localhost:*\"))\n");
 350   }
 351   cupsFileClose(fp);
 352
 353   cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdCreateProfile(job_id=%d,allow_networking=%d) = \"%s\"", job_id, allow_networking, profile);
 354   return ((void *)strdup(profile));
 355
 356 #else
 357   cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdCreateProfile(job_id=%d, allow_networking=%d) = NULL", job_id, allow_networking);
 358
 359   return (NULL);
 360 #endif /* HAVE_SANDBOX_H */
 361 }
 362
 363
 364 /*
 365  * 'cupsdDestroyProfile()' - Delete an execution profile.
 366  */
 367
 368 void
 369 cupsdDestroyProfile(void *profile)      /* I - Profile */
 370 {
 371   cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdDeleteProfile(profile=\"%s\")",
 372                   profile ? (char *)profile : "(null)");
 373
 374 #ifdef HAVE_SANDBOX_H
 375   if (profile)
 376   {
 377     unlink((char *)profile);
 378     free(profile);
 379   }
 380 #endif /* HAVE_SANDBOX_H */
 381 }
 382
 383
 384 /*
 385  * 'cupsdEndProcess()' - End a process.
 386  */
 387
 388 int                                     /* O - 0 on success, -1 on failure */
 389 cupsdEndProcess(int pid,                /* I - Process ID */
 390                 int force)              /* I - Force child to die */
 391 {
 392   cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdEndProcess(pid=%d, force=%d)", pid,
 393                   force);
 394
 395   if (!pid)
 396     return (0);
 397
 398   if (!RunUser)
 399   {
 400    /*
 401     * When running as root, cupsd puts child processes in their own process
 402     * group.  Using "-pid" sends a signal to all processes in the group.
 403     */
 404
 405     pid = -pid;
 406   }
 407
 408   if (force)
 409     return (kill(pid, SIGKILL));
 410   else
 411     return (kill(pid, SIGTERM));
 412 }
 413
 414
 415 /*
 416  * 'cupsdFinishProcess()' - Finish a process and get its name.
 417  */
 418
 419 const char *                            /* O - Process name */
 420 cupsdFinishProcess(int    pid,          /* I - Process ID */
 421                    char   *name,        /* I - Name buffer */
 422                    size_t namelen,      /* I - Size of name buffer */
 423                    int    *job_id)      /* O - Job ID pointer or NULL */
 424 {
 425   cupsd_proc_t  key,                    /* Search key */
 426                 *proc;                  /* Matching process */
 427
 428
 429   key.pid = pid;
 430
 431   if ((proc = (cupsd_proc_t *)cupsArrayFind(process_array, &key)) != NULL)
 432   {
 433     if (job_id)
 434       *job_id = proc->job_id;
 435
 436     strlcpy(name, proc->name, namelen);
 437     cupsArrayRemove(process_array, proc);
 438     free(proc);
 439   }
 440   else
 441   {
 442     if (job_id)
 443       *job_id = 0;
 444
 445     strlcpy(name, "unknown", namelen);
 446   }
 447
 448   cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdFinishProcess(pid=%d, name=%p, namelen=" CUPS_LLFMT ", job_id=%p(%d)) = \"%s\"", pid, name, CUPS_LLCAST namelen, job_id, job_id ? *job_id : 0, name);
 449
 450   return (name);
 451 }
 452
 453
 454 /*
 455  * 'cupsdStartProcess()' - Start a process.
 456  */
 457
 458 int                                     /* O - Process ID or 0 */
 459 cupsdStartProcess(
 460     const char  *command,               /* I - Full path to command */
 461     char        *argv[],                /* I - Command-line arguments */
 462     char        *envp[],                /* I - Environment */
 463     int         infd,                   /* I - Standard input file descriptor */
 464     int         outfd,                  /* I - Standard output file descriptor */
 465     int         errfd,                  /* I - Standard error file descriptor */
 466     int         backfd,                 /* I - Backchannel file descriptor */
 467     int         sidefd,                 /* I - Sidechannel file descriptor */
 468     int         root,                   /* I - Run as root? */
 469     void        *profile,               /* I - Security profile to use */
 470     cupsd_job_t *job,                   /* I - Job associated with process */
 471     int         *pid)                   /* O - Process ID */
 472 {
 473   int           i;                      /* Looping var */
 474   const char    *exec_path = command;   /* Command to be exec'd */
 475   char          *real_argv[110],        /* Real command-line arguments */
 476                 cups_exec[1024],        /* Path to "cups-exec" program */
 477                 user_str[16],           /* User string */
 478                 group_str[16],          /* Group string */
 479                 nice_str[16];           /* FilterNice string */
 480   uid_t         user;                   /* Command UID */
 481   cupsd_proc_t  *proc;                  /* New process record */
 482 #if USE_POSIX_SPAWN
 483   posix_spawn_file_actions_t actions;   /* Spawn file actions */
 484   posix_spawnattr_t attrs;              /* Spawn attributes */
 485   sigset_t      defsignals;             /* Default signals */
 486 #elif defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)
 487   struct sigaction action;              /* POSIX signal handler */
 488 #endif /* USE_POSIX_SPAWN */
 489 #if defined(__APPLE__)
 490   char          processPath[1024],      /* CFProcessPath environment variable */
 491                 linkpath[1024];         /* Link path for symlinks... */
 492   int           linkbytes;              /* Bytes for link path */
 493 #endif /* __APPLE__ */
 494
 495
 496   *pid = 0;
 497
 498  /*
 499   * Figure out the UID for the child process...
 500   */
 501
 502   if (RunUser)
 503     user = RunUser;
 504   else if (root)
 505     user = 0;
 506   else
 507     user = User;
 508
 509  /*
 510   * Check the permissions of the command we are running...
 511   */
 512
 513   if (_cupsFileCheck(command, _CUPS_FILE_CHECK_PROGRAM, !RunUser,
 514                      cupsdLogFCMessage, job ? job->printer : NULL))
 515     return (0);
 516
 517 #if defined(__APPLE__)
 518   if (envp)
 519   {
 520    /*
 521     * Add special voodoo magic for macOS - this allows macOS programs to access
 522     * their bundle resources properly...
 523     */
 524
 525     if ((linkbytes = readlink(command, linkpath, sizeof(linkpath) - 1)) > 0)
 526     {
 527      /*
 528       * Yes, this is a symlink to the actual program, nul-terminate and
 529       * use it...
 530       */
 531
 532       linkpath[linkbytes] = '\0';
 533
 534       if (linkpath[0] == '/')
 535         snprintf(processPath, sizeof(processPath), "CFProcessPath=%s",
 536                  linkpath);
 537       else
 538         snprintf(processPath, sizeof(processPath), "CFProcessPath=%s/%s",
 539                  dirname((char *)command), linkpath);
 540     }
 541     else
 542       snprintf(processPath, sizeof(processPath), "CFProcessPath=%s", command);
 543
 544     envp[0] = processPath;              /* Replace <CFProcessPath> string */
 545   }
 546 #endif  /* __APPLE__ */
 547
 548  /*
 549   * Use helper program when we have a sandbox profile...
 550   */
 551
 552 #if !USE_POSIX_SPAWN
 553   if (profile)
 554 #endif /* !USE_POSIX_SPAWN */
 555   {
 556     snprintf(cups_exec, sizeof(cups_exec), "%s/daemon/cups-exec", ServerBin);
 557     snprintf(user_str, sizeof(user_str), "%d", user);
 558     snprintf(group_str, sizeof(group_str), "%d", Group);
 559     snprintf(nice_str, sizeof(nice_str), "%d", FilterNice);
 560
 561     real_argv[0] = cups_exec;
 562     real_argv[1] = (char *)"-g";
 563     real_argv[2] = group_str;
 564     real_argv[3] = (char *)"-n";
 565     real_argv[4] = nice_str;
 566     real_argv[5] = (char *)"-u";
 567     real_argv[6] = user_str;
 568     real_argv[7] = profile ? profile : "none";
 569     real_argv[8] = (char *)command;
 570
 571     for (i = 0;
 572          i < (int)(sizeof(real_argv) / sizeof(real_argv[0]) - 10) && argv[i];
 573          i ++)
 574       real_argv[i + 9] = argv[i];
 575
 576     real_argv[i + 9] = NULL;
 577
 578     argv      = real_argv;
 579     exec_path = cups_exec;
 580   }
 581
 582   if (LogLevel == CUPSD_LOG_DEBUG2)
 583   {
 584     cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdStartProcess: Preparing to start \"%s\", arguments:", command);
 585
 586     for (i = 0; argv[i]; i ++)
 587       cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdStartProcess: argv[%d] = \"%s\"", i, argv[i]);
 588   }
 589
 590 #if USE_POSIX_SPAWN
 591  /*
 592   * Setup attributes and file actions for the spawn...
 593   */
 594
 595   cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdStartProcess: Setting spawn attributes.");
 596   sigemptyset(&defsignals);
 597   sigaddset(&defsignals, SIGTERM);
 598   sigaddset(&defsignals, SIGCHLD);
 599   sigaddset(&defsignals, SIGPIPE);
 600
 601   posix_spawnattr_init(&attrs);
 602   posix_spawnattr_setflags(&attrs, POSIX_SPAWN_SETPGROUP | POSIX_SPAWN_SETSIGDEF);
 603   posix_spawnattr_setpgroup(&attrs, 0);
 604   posix_spawnattr_setsigdefault(&attrs, &defsignals);
 605
 606   cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdStartProcess: Setting file actions.");
 607   posix_spawn_file_actions_init(&actions);
 608   if (infd != 0)
 609   {
 610     if (infd < 0)
 611       posix_spawn_file_actions_addopen(&actions, 0, "/dev/null", O_RDONLY, 0);
 612     else
 613       posix_spawn_file_actions_adddup2(&actions, infd, 0);
 614   }
 615
 616   if (outfd != 1)
 617   {
 618     if (outfd < 0)
 619       posix_spawn_file_actions_addopen(&actions, 1, "/dev/null", O_WRONLY, 0);
 620     else
 621       posix_spawn_file_actions_adddup2(&actions, outfd, 1);
 622   }
 623
 624   if (errfd != 2)
 625   {
 626     if (errfd < 0)
 627       posix_spawn_file_actions_addopen(&actions, 2, "/dev/null", O_WRONLY, 0);
 628     else
 629       posix_spawn_file_actions_adddup2(&actions, errfd, 2);
 630   }
 631
 632   if (backfd != 3 && backfd >= 0)
 633     posix_spawn_file_actions_adddup2(&actions, backfd, 3);
 634
 635   if (sidefd != 4 && sidefd >= 0)
 636     posix_spawn_file_actions_adddup2(&actions, sidefd, 4);
 637
 638   cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdStartProcess: Calling posix_spawn.");
 639
 640   if (posix_spawn(pid, exec_path, &actions, &attrs, argv, envp ? envp : environ))
 641   {
 642     cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to fork %s - %s.", command, strerror(errno));
 643
 644     *pid = 0;
 645   }
 646   else
 647     cupsdLogMessage(CUPSD_LOG_DEBUG2, "cupsdStartProcess: pid=%d", (int)*pid);
 648
 649   posix_spawn_file_actions_destroy(&actions);
 650   posix_spawnattr_destroy(&attrs);
 651
 652 #else
 653  /*
 654   * Block signals before forking...
 655   */
 656
 657   cupsdHoldSignals();
 658
 659   if ((*pid = fork()) == 0)
 660   {
 661    /*
 662     * Child process goes here; update stderr as needed...
 663     */
 664
 665     if (errfd != 2)
 666     {
 667       if (errfd < 0)
 668         errfd = open("/dev/null", O_WRONLY);
 669
 670       if (errfd != 2)
 671       {
 672         dup2(errfd, 2);
 673         close(errfd);
 674       }
 675     }
 676
 677    /*
 678     * Put this process in its own process group so that we can kill any child
 679     * processes it creates.
 680     */
 681
 682 #  ifdef HAVE_SETPGID
 683     if (!RunUser && setpgid(0, 0))
 684       exit(errno + 100);
 685 #  else
 686     if (!RunUser && setpgrp())
 687       exit(errno + 100);
 688 #  endif /* HAVE_SETPGID */
 689
 690    /*
 691     * Update the remaining file descriptors as needed...
 692     */
 693
 694     if (infd != 0)
 695     {
 696       if (infd < 0)
 697         infd = open("/dev/null", O_RDONLY);
 698
 699       if (infd != 0)
 700       {
 701         dup2(infd, 0);
 702         close(infd);
 703       }
 704     }
 705
 706     if (outfd != 1)
 707     {
 708       if (outfd < 0)
 709         outfd = open("/dev/null", O_WRONLY);
 710
 711       if (outfd != 1)
 712       {
 713         dup2(outfd, 1);
 714         close(outfd);
 715       }
 716     }
 717
 718     if (backfd != 3 && backfd >= 0)
 719     {
 720       dup2(backfd, 3);
 721       close(backfd);
 722       fcntl(3, F_SETFL, O_NDELAY);
 723     }
 724
 725     if (sidefd != 4 && sidefd >= 0)
 726     {
 727       dup2(sidefd, 4);
 728       close(sidefd);
 729       fcntl(4, F_SETFL, O_NDELAY);
 730     }
 731
 732    /*
 733     * Change the priority of the process based on the FilterNice setting.
 734     * (this is not done for root processes...)
 735     */
 736
 737     if (!root)
 738       nice(FilterNice);
 739
 740    /*
 741     * Reset group membership to just the main one we belong to.
 742     */
 743
 744     if (!RunUser && setgid(Group))
 745       exit(errno + 100);
 746
 747     if (!RunUser && setgroups(1, &Group))
 748       exit(errno + 100);
 749
 750    /*
 751     * Change user to something "safe"...
 752     */
 753
 754     if (!RunUser && user && setuid(user))
 755       exit(errno + 100);
 756
 757    /*
 758     * Change umask to restrict permissions on created files...
 759     */
 760
 761     umask(077);
 762
 763    /*
 764     * Unblock signals before doing the exec...
 765     */
 766
 767 #  ifdef HAVE_SIGSET
 768     sigset(SIGTERM, SIG_DFL);
 769     sigset(SIGCHLD, SIG_DFL);
 770     sigset(SIGPIPE, SIG_DFL);
 771 #  elif defined(HAVE_SIGACTION)
 772     memset(&action, 0, sizeof(action));
 773
 774     sigemptyset(&action.sa_mask);
 775     action.sa_handler = SIG_DFL;
 776
 777     sigaction(SIGTERM, &action, NULL);
 778     sigaction(SIGCHLD, &action, NULL);
 779     sigaction(SIGPIPE, &action, NULL);
 780 #  else
 781     signal(SIGTERM, SIG_DFL);
 782     signal(SIGCHLD, SIG_DFL);
 783     signal(SIGPIPE, SIG_DFL);
 784 #  endif /* HAVE_SIGSET */
 785
 786     cupsdReleaseSignals();
 787
 788    /*
 789     * Execute the command; if for some reason this doesn't work, log an error
 790     * exit with a non-zero value...
 791     */
 792
 793     if (envp)
 794       execve(exec_path, argv, envp);
 795     else
 796       execv(exec_path, argv);
 797
 798     exit(errno + 100);
 799   }
 800   else if (*pid < 0)
 801   {
 802    /*
 803     * Error - couldn't fork a new process!
 804     */
 805
 806     cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to fork %s - %s.", command,
 807                     strerror(errno));
 808
 809     *pid = 0;
 810   }
 811
 812   cupsdReleaseSignals();
 813 #endif /* USE_POSIX_SPAWN */
 814
 815   if (*pid)
 816   {
 817     if (!process_array)
 818       process_array = cupsArrayNew((cups_array_func_t)compare_procs, NULL);
 819
 820     if (process_array)
 821     {
 822       if ((proc = calloc(1, sizeof(cupsd_proc_t) + strlen(command))) != NULL)
 823       {
 824         proc->pid    = *pid;
 825         proc->job_id = job ? job->id : 0;
 826         _cups_strcpy(proc->name, command);
 827
 828         cupsArrayAdd(process_array, proc);
 829       }
 830     }
 831   }
 832
 833   cupsdLogMessage(CUPSD_LOG_DEBUG2,
 834                   "cupsdStartProcess(command=\"%s\", argv=%p, envp=%p, "
 835                   "infd=%d, outfd=%d, errfd=%d, backfd=%d, sidefd=%d, root=%d, "
 836                   "profile=%p, job=%p(%d), pid=%p) = %d",
 837                   command, argv, envp, infd, outfd, errfd, backfd, sidefd,
 838                   root, profile, job, job ? job->id : 0, pid, *pid);
 839
 840   return (*pid);
 841 }
 842
 843
 844 /*
 845  * 'compare_procs()' - Compare two processes.
 846  */
 847
 848 static int                              /* O - Result of comparison */
 849 compare_procs(cupsd_proc_t *a,          /* I - First process */
 850               cupsd_proc_t *b)          /* I - Second process */
 851 {
 852   return (a->pid - b->pid);
 853 }
 854
 855
 856 #ifdef HAVE_SANDBOX_H
 857 /*
 858  * 'cupsd_requote()' - Make a regular-expression version of a string.
 859  */
 860
 861 static char *                           /* O - Quoted string */
 862 cupsd_requote(char       *dst,          /* I - Destination buffer */
 863               const char *src,          /* I - Source string */
 864               size_t     dstsize)       /* I - Size of destination buffer */
 865 {
 866   int   ch;                             /* Current character */
 867   char  *dstptr,                        /* Current position in buffer */
 868         *dstend;                        /* End of destination buffer */
 869
 870
 871   dstptr = dst;
 872   dstend = dst + dstsize - 2;
 873
 874   while (*src && dstptr < dstend)
 875   {
 876     ch = *src++;
 877
 878     if (ch == '/' && !*src)
 879       break;                            /* Don't add trailing slash */
 880
 881     if (strchr(".?*()[]^$\\\"", ch))
 882       *dstptr++ = '\\';
 883
 884     *dstptr++ = (char)ch;
 885   }
 886
 887   *dstptr = '\0';
 888
 889   return (dst);
 890 }
 891 #endif /* HAVE_SANDBOX_H */