D-Bus 1.4.1

dbus-sysdeps-util-unix.c

00001 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
00002 /* dbus-sysdeps-util-unix.c Would be in dbus-sysdeps-unix.c, but not used in libdbus
00003  * 
00004  * Copyright (C) 2002, 2003, 2004, 2005  Red Hat, Inc.
00005  * Copyright (C) 2003 CodeFactory AB
00006  *
00007  * Licensed under the Academic Free License version 2.1
00008  * 
00009  * This program is free software; you can redistribute it and/or modify
00010  * it under the terms of the GNU General Public License as published by
00011  * the Free Software Foundation; either version 2 of the License, or
00012  * (at your option) any later version.
00013  *
00014  * This program is distributed in the hope that it will be useful,
00015  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00016  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00017  * GNU General Public License for more details.
00018  * 
00019  * You should have received a copy of the GNU General Public License
00020  * along with this program; if not, write to the Free Software
00021  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
00022  *
00023  */
00024 
00025 #include <config.h>
00026 #include "dbus-sysdeps.h"
00027 #include "dbus-sysdeps-unix.h"
00028 #include "dbus-internals.h"
00029 #include "dbus-pipe.h"
00030 #include "dbus-protocol.h"
00031 #include "dbus-string.h"
00032 #define DBUS_USERDB_INCLUDES_PRIVATE 1
00033 #include "dbus-userdb.h"
00034 #include "dbus-test.h"
00035 
00036 #include <sys/types.h>
00037 #include <stdlib.h>
00038 #include <string.h>
00039 #include <signal.h>
00040 #include <unistd.h>
00041 #include <stdio.h>
00042 #include <errno.h>
00043 #include <fcntl.h>
00044 #include <sys/stat.h>
00045 #ifdef HAVE_SYS_RESOURCE_H
00046 #include <sys/resource.h>
00047 #endif
00048 #include <grp.h>
00049 #include <sys/socket.h>
00050 #include <dirent.h>
00051 #include <sys/un.h>
00052 #include <syslog.h>
00053 
00054 #ifdef HAVE_SYS_SYSLIMITS_H
00055 #include <sys/syslimits.h>
00056 #endif
00057 
00058 #ifndef O_BINARY
00059 #define O_BINARY 0
00060 #endif
00061 
00077 dbus_bool_t
00078 _dbus_become_daemon (const DBusString *pidfile,
00079                      DBusPipe         *print_pid_pipe,
00080                      DBusError        *error,
00081                      dbus_bool_t       keep_umask)
00082 {
00083   const char *s;
00084   pid_t child_pid;
00085   int dev_null_fd;
00086 
00087   _dbus_verbose ("Becoming a daemon...\n");
00088 
00089   _dbus_verbose ("chdir to /\n");
00090   if (chdir ("/") < 0)
00091     {
00092       dbus_set_error (error, DBUS_ERROR_FAILED,
00093                       "Could not chdir() to root directory");
00094       return FALSE;
00095     }
00096 
00097   _dbus_verbose ("forking...\n");
00098   switch ((child_pid = fork ()))
00099     {
00100     case -1:
00101       _dbus_verbose ("fork failed\n");
00102       dbus_set_error (error, _dbus_error_from_errno (errno),
00103                       "Failed to fork daemon: %s", _dbus_strerror (errno));
00104       return FALSE;
00105       break;
00106 
00107     case 0:
00108       _dbus_verbose ("in child, closing std file descriptors\n");
00109 
00110       /* silently ignore failures here, if someone
00111        * doesn't have /dev/null we may as well try
00112        * to continue anyhow
00113        */
00114       
00115       dev_null_fd = open ("/dev/null", O_RDWR);
00116       if (dev_null_fd >= 0)
00117         {
00118           dup2 (dev_null_fd, 0);
00119           dup2 (dev_null_fd, 1);
00120           
00121           s = _dbus_getenv ("DBUS_DEBUG_OUTPUT");
00122           if (s == NULL || *s == '\0')
00123             dup2 (dev_null_fd, 2);
00124           else
00125             _dbus_verbose ("keeping stderr open due to DBUS_DEBUG_OUTPUT\n");
00126         }
00127 
00128       if (!keep_umask)
00129         {
00130           /* Get a predictable umask */
00131           _dbus_verbose ("setting umask\n");
00132           umask (022);
00133         }
00134 
00135       _dbus_verbose ("calling setsid()\n");
00136       if (setsid () == -1)
00137         _dbus_assert_not_reached ("setsid() failed");
00138       
00139       break;
00140 
00141     default:
00142       if (!_dbus_write_pid_to_file_and_pipe (pidfile, print_pid_pipe,
00143                                              child_pid, error))
00144         {
00145           _dbus_verbose ("pid file or pipe write failed: %s\n",
00146                          error->message);
00147           kill (child_pid, SIGTERM);
00148           return FALSE;
00149         }
00150 
00151       _dbus_verbose ("parent exiting\n");
00152       _exit (0);
00153       break;
00154     }
00155   
00156   return TRUE;
00157 }
00158 
00159 
00168 static dbus_bool_t
00169 _dbus_write_pid_file (const DBusString *filename,
00170                       unsigned long     pid,
00171                       DBusError        *error)
00172 {
00173   const char *cfilename;
00174   int fd;
00175   FILE *f;
00176 
00177   cfilename = _dbus_string_get_const_data (filename);
00178   
00179   fd = open (cfilename, O_WRONLY|O_CREAT|O_EXCL|O_BINARY, 0644);
00180   
00181   if (fd < 0)
00182     {
00183       dbus_set_error (error, _dbus_error_from_errno (errno),
00184                       "Failed to open \"%s\": %s", cfilename,
00185                       _dbus_strerror (errno));
00186       return FALSE;
00187     }
00188 
00189   if ((f = fdopen (fd, "w")) == NULL)
00190     {
00191       dbus_set_error (error, _dbus_error_from_errno (errno),
00192                       "Failed to fdopen fd %d: %s", fd, _dbus_strerror (errno));
00193       _dbus_close (fd, NULL);
00194       return FALSE;
00195     }
00196   
00197   if (fprintf (f, "%lu\n", pid) < 0)
00198     {
00199       dbus_set_error (error, _dbus_error_from_errno (errno),
00200                       "Failed to write to \"%s\": %s", cfilename,
00201                       _dbus_strerror (errno));
00202       
00203       fclose (f);
00204       return FALSE;
00205     }
00206 
00207   if (fclose (f) == EOF)
00208     {
00209       dbus_set_error (error, _dbus_error_from_errno (errno),
00210                       "Failed to close \"%s\": %s", cfilename,
00211                       _dbus_strerror (errno));
00212       return FALSE;
00213     }
00214   
00215   return TRUE;
00216 }
00217 
00229 dbus_bool_t
00230 _dbus_write_pid_to_file_and_pipe (const DBusString *pidfile,
00231                                   DBusPipe         *print_pid_pipe,
00232                                   dbus_pid_t        pid_to_write,
00233                                   DBusError        *error)
00234 {
00235   if (pidfile)
00236     {
00237       _dbus_verbose ("writing pid file %s\n", _dbus_string_get_const_data (pidfile));
00238       if (!_dbus_write_pid_file (pidfile,
00239                                  pid_to_write,
00240                                  error))
00241         {
00242           _dbus_verbose ("pid file write failed\n");
00243           _DBUS_ASSERT_ERROR_IS_SET(error);
00244           return FALSE;
00245         }
00246     }
00247   else
00248     {
00249       _dbus_verbose ("No pid file requested\n");
00250     }
00251 
00252   if (print_pid_pipe != NULL && _dbus_pipe_is_valid (print_pid_pipe))
00253     {
00254       DBusString pid;
00255       int bytes;
00256 
00257       _dbus_verbose ("writing our pid to pipe %"PRIuPTR"\n",
00258                      print_pid_pipe->fd_or_handle);
00259       
00260       if (!_dbus_string_init (&pid))
00261         {
00262           _DBUS_SET_OOM (error);
00263           return FALSE;
00264         }
00265           
00266       if (!_dbus_string_append_int (&pid, pid_to_write) ||
00267           !_dbus_string_append (&pid, "\n"))
00268         {
00269           _dbus_string_free (&pid);
00270           _DBUS_SET_OOM (error);
00271           return FALSE;
00272         }
00273           
00274       bytes = _dbus_string_get_length (&pid);
00275       if (_dbus_pipe_write (print_pid_pipe, &pid, 0, bytes, error) != bytes)
00276         {
00277           /* _dbus_pipe_write sets error only on failure, not short write */
00278           if (error != NULL && !dbus_error_is_set(error))
00279             {
00280               dbus_set_error (error, DBUS_ERROR_FAILED,
00281                               "Printing message bus PID: did not write enough bytes\n");
00282             }
00283           _dbus_string_free (&pid);
00284           return FALSE;
00285         }
00286           
00287       _dbus_string_free (&pid);
00288     }
00289   else
00290     {
00291       _dbus_verbose ("No pid pipe to write to\n");
00292     }
00293 
00294   return TRUE;
00295 }
00296 
00303 dbus_bool_t
00304 _dbus_verify_daemon_user (const char *user)
00305 {
00306   DBusString u;
00307 
00308   _dbus_string_init_const (&u, user);
00309 
00310   return _dbus_get_user_id_and_primary_group (&u, NULL, NULL);
00311 }
00312 
00313 
00314 /* The HAVE_LIBAUDIT case lives in selinux.c */
00315 #ifndef HAVE_LIBAUDIT
00316 
00323 dbus_bool_t
00324 _dbus_change_to_daemon_user  (const char    *user,
00325                               DBusError     *error)
00326 {
00327   dbus_uid_t uid;
00328   dbus_gid_t gid;
00329   DBusString u;
00330 
00331   _dbus_string_init_const (&u, user);
00332 
00333   if (!_dbus_get_user_id_and_primary_group (&u, &uid, &gid))
00334     {
00335       dbus_set_error (error, DBUS_ERROR_FAILED,
00336                       "User '%s' does not appear to exist?",
00337                       user);
00338       return FALSE;
00339     }
00340 
00341   /* setgroups() only works if we are a privileged process,
00342    * so we don't return error on failure; the only possible
00343    * failure is that we don't have perms to do it.
00344    *
00345    * not sure this is right, maybe if setuid()
00346    * is going to work then setgroups() should also work.
00347    */
00348   if (setgroups (0, NULL) < 0)
00349     _dbus_warn ("Failed to drop supplementary groups: %s\n",
00350                 _dbus_strerror (errno));
00351 
00352   /* Set GID first, or the setuid may remove our permission
00353    * to change the GID
00354    */
00355   if (setgid (gid) < 0)
00356     {
00357       dbus_set_error (error, _dbus_error_from_errno (errno),
00358                       "Failed to set GID to %lu: %s", gid,
00359                       _dbus_strerror (errno));
00360       return FALSE;
00361     }
00362 
00363   if (setuid (uid) < 0)
00364     {
00365       dbus_set_error (error, _dbus_error_from_errno (errno),
00366                       "Failed to set UID to %lu: %s", uid,
00367                       _dbus_strerror (errno));
00368       return FALSE;
00369     }
00370 
00371   return TRUE;
00372 }
00373 #endif /* !HAVE_LIBAUDIT */
00374 
00375 
00386 void
00387 _dbus_request_file_descriptor_limit (unsigned int limit)
00388 {
00389 #ifdef HAVE_SETRLIMIT
00390   struct rlimit lim;
00391   struct rlimit target_lim;
00392   unsigned int current_limit;
00393 
00394   /* No point to doing this practically speaking
00395    * if we're not uid 0.  We expect the system
00396    * bus to use this before we change UID, and
00397    * the session bus takes the Linux default
00398    * of 1024 for both cur and max.
00399    */
00400   if (getuid () != 0)
00401     return;
00402 
00403   if (getrlimit (RLIMIT_NOFILE, &lim) < 0)
00404     return;
00405 
00406   if (lim.rlim_cur >= limit)
00407     return;
00408 
00409   /* Ignore "maximum limit", assume we have the "superuser"
00410    * privileges.  On Linux this is CAP_SYS_RESOURCE.
00411    */
00412   target_lim.rlim_cur = target_lim.rlim_max = limit;
00413   /* Also ignore errors; if we fail, we will at least work
00414    * up to whatever limit we had, which seems better than
00415    * just outright aborting.
00416    *
00417    * However, in the future we should probably log this so OS builders
00418    * have a chance to notice any misconfiguration like dbus-daemon
00419    * being started without CAP_SYS_RESOURCE.
00420    */
00421   setrlimit (RLIMIT_NOFILE, &target_lim);
00422 #endif
00423 }
00424 
00425 void 
00426 _dbus_init_system_log (void)
00427 {
00428   openlog ("dbus", LOG_PID, LOG_DAEMON);
00429 }
00438 void
00439 _dbus_system_log (DBusSystemLogSeverity severity, const char *msg, ...)
00440 {
00441   va_list args;
00442 
00443   va_start (args, msg);
00444 
00445   _dbus_system_logv (severity, msg, args);
00446 
00447   va_end (args);
00448 }
00449 
00460 void
00461 _dbus_system_logv (DBusSystemLogSeverity severity, const char *msg, va_list args)
00462 {
00463   int flags;
00464   switch (severity)
00465     {
00466       case DBUS_SYSTEM_LOG_INFO:
00467         flags =  LOG_DAEMON | LOG_NOTICE;
00468         break;
00469       case DBUS_SYSTEM_LOG_SECURITY:
00470         flags = LOG_AUTH | LOG_NOTICE;
00471         break;
00472       case DBUS_SYSTEM_LOG_FATAL:
00473         flags = LOG_DAEMON|LOG_CRIT;
00474       default:
00475         return;
00476     }
00477 
00478   vsyslog (flags, msg, args);
00479 
00480   if (severity == DBUS_SYSTEM_LOG_FATAL)
00481     exit (1);
00482 }
00483 
00489 void
00490 _dbus_set_signal_handler (int               sig,
00491                           DBusSignalHandler handler)
00492 {
00493   struct sigaction act;
00494   sigset_t empty_mask;
00495   
00496   sigemptyset (&empty_mask);
00497   act.sa_handler = handler;
00498   act.sa_mask    = empty_mask;
00499   act.sa_flags   = 0;
00500   sigaction (sig,  &act, NULL);
00501 }
00502 
00508 dbus_bool_t 
00509 _dbus_file_exists (const char *file)
00510 {
00511   return (access (file, F_OK) == 0);
00512 }
00513 
00520 dbus_bool_t 
00521 _dbus_user_at_console (const char *username,
00522                        DBusError  *error)
00523 {
00524 
00525   DBusString f;
00526   dbus_bool_t result;
00527 
00528   result = FALSE;
00529   if (!_dbus_string_init (&f))
00530     {
00531       _DBUS_SET_OOM (error);
00532       return FALSE;
00533     }
00534 
00535   if (!_dbus_string_append (&f, DBUS_CONSOLE_AUTH_DIR))
00536     {
00537       _DBUS_SET_OOM (error);
00538       goto out;
00539     }
00540 
00541 
00542   if (!_dbus_string_append (&f, username))
00543     {
00544       _DBUS_SET_OOM (error);
00545       goto out;
00546     }
00547 
00548   result = _dbus_file_exists (_dbus_string_get_const_data (&f));
00549 
00550  out:
00551   _dbus_string_free (&f);
00552 
00553   return result;
00554 }
00555 
00556 
00563 dbus_bool_t
00564 _dbus_path_is_absolute (const DBusString *filename)
00565 {
00566   if (_dbus_string_get_length (filename) > 0)
00567     return _dbus_string_get_byte (filename, 0) == '/';
00568   else
00569     return FALSE;
00570 }
00571 
00580 dbus_bool_t
00581 _dbus_stat (const DBusString *filename,
00582             DBusStat         *statbuf,
00583             DBusError        *error)
00584 {
00585   const char *filename_c;
00586   struct stat sb;
00587 
00588   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
00589   
00590   filename_c = _dbus_string_get_const_data (filename);
00591 
00592   if (stat (filename_c, &sb) < 0)
00593     {
00594       dbus_set_error (error, _dbus_error_from_errno (errno),
00595                       "%s", _dbus_strerror (errno));
00596       return FALSE;
00597     }
00598 
00599   statbuf->mode = sb.st_mode;
00600   statbuf->nlink = sb.st_nlink;
00601   statbuf->uid = sb.st_uid;
00602   statbuf->gid = sb.st_gid;
00603   statbuf->size = sb.st_size;
00604   statbuf->atime = sb.st_atime;
00605   statbuf->mtime = sb.st_mtime;
00606   statbuf->ctime = sb.st_ctime;
00607 
00608   return TRUE;
00609 }
00610 
00611 
00615 struct DBusDirIter
00616 {
00617   DIR *d; 
00619 };
00620 
00628 DBusDirIter*
00629 _dbus_directory_open (const DBusString *filename,
00630                       DBusError        *error)
00631 {
00632   DIR *d;
00633   DBusDirIter *iter;
00634   const char *filename_c;
00635 
00636   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
00637   
00638   filename_c = _dbus_string_get_const_data (filename);
00639 
00640   d = opendir (filename_c);
00641   if (d == NULL)
00642     {
00643       dbus_set_error (error, _dbus_error_from_errno (errno),
00644                       "Failed to read directory \"%s\": %s",
00645                       filename_c,
00646                       _dbus_strerror (errno));
00647       return NULL;
00648     }
00649   iter = dbus_new0 (DBusDirIter, 1);
00650   if (iter == NULL)
00651     {
00652       closedir (d);
00653       dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
00654                       "Could not allocate memory for directory iterator");
00655       return NULL;
00656     }
00657 
00658   iter->d = d;
00659 
00660   return iter;
00661 }
00662 
00663 /* Calculate the required buffer size (in bytes) for directory
00664  * entries read from the given directory handle.  Return -1 if this
00665  * this cannot be done. 
00666  *
00667  * If you use autoconf, include fpathconf and dirfd in your
00668  * AC_CHECK_FUNCS list.  Otherwise use some other method to detect
00669  * and use them where available.
00670  */
00671 static dbus_bool_t
00672 dirent_buf_size(DIR * dirp, size_t *size)
00673 {
00674  long name_max;
00675 #   if defined(HAVE_FPATHCONF) && defined(_PC_NAME_MAX)
00676 #      if defined(HAVE_DIRFD)
00677           name_max = fpathconf(dirfd(dirp), _PC_NAME_MAX);
00678 #      elif defined(HAVE_DDFD)
00679           name_max = fpathconf(dirp->dd_fd, _PC_NAME_MAX);
00680 #      else
00681           name_max = fpathconf(dirp->__dd_fd, _PC_NAME_MAX);
00682 #      endif /* HAVE_DIRFD */
00683      if (name_max == -1)
00684 #           if defined(NAME_MAX)
00685              name_max = NAME_MAX;
00686 #           else
00687              return FALSE;
00688 #           endif
00689 #   elif defined(MAXNAMELEN)
00690      name_max = MAXNAMELEN;
00691 #   else
00692 #       if defined(NAME_MAX)
00693          name_max = NAME_MAX;
00694 #       else
00695 #           error "buffer size for readdir_r cannot be determined"
00696 #       endif
00697 #   endif
00698   if (size)
00699     *size = (size_t)offsetof(struct dirent, d_name) + name_max + 1;
00700   else
00701     return FALSE;
00702 
00703   return TRUE;
00704 }
00705 
00716 dbus_bool_t
00717 _dbus_directory_get_next_file (DBusDirIter      *iter,
00718                                DBusString       *filename,
00719                                DBusError        *error)
00720 {
00721   struct dirent *d, *ent;
00722   size_t buf_size;
00723   int err;
00724 
00725   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
00726  
00727   if (!dirent_buf_size (iter->d, &buf_size))
00728     {
00729       dbus_set_error (error, DBUS_ERROR_FAILED,
00730                       "Can't calculate buffer size when reading directory");
00731       return FALSE;
00732     }
00733 
00734   d = (struct dirent *)dbus_malloc (buf_size);
00735   if (!d)
00736     {
00737       dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
00738                       "No memory to read directory entry");
00739       return FALSE;
00740     }
00741 
00742  again:
00743   err = readdir_r (iter->d, d, &ent);
00744   if (err || !ent)
00745     {
00746       if (err != 0)
00747         dbus_set_error (error,
00748                         _dbus_error_from_errno (err),
00749                         "%s", _dbus_strerror (err));
00750 
00751       dbus_free (d);
00752       return FALSE;
00753     }
00754   else if (ent->d_name[0] == '.' &&
00755            (ent->d_name[1] == '\0' ||
00756             (ent->d_name[1] == '.' && ent->d_name[2] == '\0')))
00757     goto again;
00758   else
00759     {
00760       _dbus_string_set_length (filename, 0);
00761       if (!_dbus_string_append (filename, ent->d_name))
00762         {
00763           dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
00764                           "No memory to read directory entry");
00765           dbus_free (d);
00766           return FALSE;
00767         }
00768       else
00769         {
00770           dbus_free (d);
00771           return TRUE;
00772         }
00773     }
00774 }
00775 
00779 void
00780 _dbus_directory_close (DBusDirIter *iter)
00781 {
00782   closedir (iter->d);
00783   dbus_free (iter);
00784 }
00785 
00786 static dbus_bool_t
00787 fill_user_info_from_group (struct group  *g,
00788                            DBusGroupInfo *info,
00789                            DBusError     *error)
00790 {
00791   _dbus_assert (g->gr_name != NULL);
00792   
00793   info->gid = g->gr_gid;
00794   info->groupname = _dbus_strdup (g->gr_name);
00795 
00796   /* info->members = dbus_strdupv (g->gr_mem) */
00797   
00798   if (info->groupname == NULL)
00799     {
00800       dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
00801       return FALSE;
00802     }
00803 
00804   return TRUE;
00805 }
00806 
00807 static dbus_bool_t
00808 fill_group_info (DBusGroupInfo    *info,
00809                  dbus_gid_t        gid,
00810                  const DBusString *groupname,
00811                  DBusError        *error)
00812 {
00813   const char *group_c_str;
00814 
00815   _dbus_assert (groupname != NULL || gid != DBUS_GID_UNSET);
00816   _dbus_assert (groupname == NULL || gid == DBUS_GID_UNSET);
00817 
00818   if (groupname)
00819     group_c_str = _dbus_string_get_const_data (groupname);
00820   else
00821     group_c_str = NULL;
00822   
00823   /* For now assuming that the getgrnam() and getgrgid() flavors
00824    * always correspond to the pwnam flavors, if not we have
00825    * to add more configure checks.
00826    */
00827   
00828 #if defined (HAVE_POSIX_GETPWNAM_R) || defined (HAVE_NONPOSIX_GETPWNAM_R)
00829   {
00830     struct group *g;
00831     int result;
00832     size_t buflen;
00833     char *buf;
00834     struct group g_str;
00835     dbus_bool_t b;
00836 
00837     /* retrieve maximum needed size for buf */
00838     buflen = sysconf (_SC_GETGR_R_SIZE_MAX);
00839 
00840     /* sysconf actually returns a long, but everything else expects size_t,
00841      * so just recast here.
00842      * https://bugs.freedesktop.org/show_bug.cgi?id=17061
00843      */
00844     if ((long) buflen <= 0)
00845       buflen = 1024;
00846 
00847     result = -1;
00848     while (1)
00849       {
00850         buf = dbus_malloc (buflen);
00851         if (buf == NULL)
00852           {
00853             dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
00854             return FALSE;
00855           }
00856 
00857         g = NULL;
00858 #ifdef HAVE_POSIX_GETPWNAM_R
00859         if (group_c_str)
00860           result = getgrnam_r (group_c_str, &g_str, buf, buflen,
00861                                &g);
00862         else
00863           result = getgrgid_r (gid, &g_str, buf, buflen,
00864                                &g);
00865 #else
00866         g = getgrnam_r (group_c_str, &g_str, buf, buflen);
00867         result = 0;
00868 #endif /* !HAVE_POSIX_GETPWNAM_R */
00869         /* Try a bigger buffer if ERANGE was returned:
00870            https://bugs.freedesktop.org/show_bug.cgi?id=16727
00871         */
00872         if (result == ERANGE && buflen < 512 * 1024)
00873           {
00874             dbus_free (buf);
00875             buflen *= 2;
00876           }
00877         else
00878           {
00879             break;
00880           }
00881       }
00882 
00883     if (result == 0 && g == &g_str)
00884       {
00885         b = fill_user_info_from_group (g, info, error);
00886         dbus_free (buf);
00887         return b;
00888       }
00889     else
00890       {
00891         dbus_set_error (error, _dbus_error_from_errno (errno),
00892                         "Group %s unknown or failed to look it up\n",
00893                         group_c_str ? group_c_str : "???");
00894         dbus_free (buf);
00895         return FALSE;
00896       }
00897   }
00898 #else /* ! HAVE_GETPWNAM_R */
00899   {
00900     /* I guess we're screwed on thread safety here */
00901     struct group *g;
00902 
00903     g = getgrnam (group_c_str);
00904 
00905     if (g != NULL)
00906       {
00907         return fill_user_info_from_group (g, info, error);
00908       }
00909     else
00910       {
00911         dbus_set_error (error, _dbus_error_from_errno (errno),
00912                         "Group %s unknown or failed to look it up\n",
00913                         group_c_str ? group_c_str : "???");
00914         return FALSE;
00915       }
00916   }
00917 #endif  /* ! HAVE_GETPWNAM_R */
00918 }
00919 
00929 dbus_bool_t
00930 _dbus_group_info_fill (DBusGroupInfo    *info,
00931                        const DBusString *groupname,
00932                        DBusError        *error)
00933 {
00934   return fill_group_info (info, DBUS_GID_UNSET,
00935                           groupname, error);
00936 
00937 }
00938 
00948 dbus_bool_t
00949 _dbus_group_info_fill_gid (DBusGroupInfo *info,
00950                            dbus_gid_t     gid,
00951                            DBusError     *error)
00952 {
00953   return fill_group_info (info, gid, NULL, error);
00954 }
00955 
00964 dbus_bool_t
00965 _dbus_parse_unix_user_from_config (const DBusString  *username,
00966                                    dbus_uid_t        *uid_p)
00967 {
00968   return _dbus_get_user_id (username, uid_p);
00969 
00970 }
00971 
00980 dbus_bool_t
00981 _dbus_parse_unix_group_from_config (const DBusString  *groupname,
00982                                     dbus_gid_t        *gid_p)
00983 {
00984   return _dbus_get_group_id (groupname, gid_p);
00985 }
00986 
00997 dbus_bool_t
00998 _dbus_unix_groups_from_uid (dbus_uid_t            uid,
00999                             dbus_gid_t          **group_ids,
01000                             int                  *n_group_ids)
01001 {
01002   return _dbus_groups_from_uid (uid, group_ids, n_group_ids);
01003 }
01004 
01014 dbus_bool_t
01015 _dbus_unix_user_is_at_console (dbus_uid_t         uid,
01016                                DBusError         *error)
01017 {
01018   return _dbus_is_console_user (uid, error);
01019 
01020 }
01021 
01029 dbus_bool_t
01030 _dbus_unix_user_is_process_owner (dbus_uid_t uid)
01031 {
01032   return uid == _dbus_geteuid ();
01033 }
01034 
01042 dbus_bool_t
01043 _dbus_windows_user_is_process_owner (const char *windows_sid)
01044 {
01045   return FALSE;
01046 }
01047  /* End of DBusInternalsUtils functions */
01049 
01061 dbus_bool_t
01062 _dbus_string_get_dirname  (const DBusString *filename,
01063                            DBusString       *dirname)
01064 {
01065   int sep;
01066   
01067   _dbus_assert (filename != dirname);
01068   _dbus_assert (filename != NULL);
01069   _dbus_assert (dirname != NULL);
01070 
01071   /* Ignore any separators on the end */
01072   sep = _dbus_string_get_length (filename);
01073   if (sep == 0)
01074     return _dbus_string_append (dirname, "."); /* empty string passed in */
01075     
01076   while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/')
01077     --sep;
01078 
01079   _dbus_assert (sep >= 0);
01080   
01081   if (sep == 0)
01082     return _dbus_string_append (dirname, "/");
01083   
01084   /* Now find the previous separator */
01085   _dbus_string_find_byte_backward (filename, sep, '/', &sep);
01086   if (sep < 0)
01087     return _dbus_string_append (dirname, ".");
01088   
01089   /* skip multiple separators */
01090   while (sep > 0 && _dbus_string_get_byte (filename, sep - 1) == '/')
01091     --sep;
01092 
01093   _dbus_assert (sep >= 0);
01094   
01095   if (sep == 0 &&
01096       _dbus_string_get_byte (filename, 0) == '/')
01097     return _dbus_string_append (dirname, "/");
01098   else
01099     return _dbus_string_copy_len (filename, 0, sep - 0,
01100                                   dirname, _dbus_string_get_length (dirname));
01101 } /* DBusString stuff */
01103 
01104 static void
01105 string_squash_nonprintable (DBusString *str)
01106 {
01107   unsigned char *buf;
01108   int i, len; 
01109   
01110   buf = _dbus_string_get_data (str);
01111   len = _dbus_string_get_length (str);
01112   
01113   for (i = 0; i < len; i++)
01114     {
01115           unsigned char c = (unsigned char) buf[i];
01116       if (c == '\0')
01117         c = ' ';
01118       else if (c < 0x20 || c > 127)
01119         c = '?';
01120     }
01121 }
01122 
01137 dbus_bool_t 
01138 _dbus_command_for_pid (unsigned long  pid,
01139                        DBusString    *str,
01140                        int            max_len,
01141                        DBusError     *error)
01142 {
01143   /* This is all Linux-specific for now */
01144   DBusString path;
01145   DBusString cmdline;
01146   int fd;
01147   
01148   if (!_dbus_string_init (&path)) 
01149     {
01150       _DBUS_SET_OOM (error);
01151       return FALSE;
01152     }
01153   
01154   if (!_dbus_string_init (&cmdline))
01155     {
01156       _DBUS_SET_OOM (error);
01157       _dbus_string_free (&path);
01158       return FALSE;
01159     }
01160   
01161   if (!_dbus_string_append_printf (&path, "/proc/%ld/cmdline", pid))
01162     goto oom;
01163   
01164   fd = open (_dbus_string_get_const_data (&path), O_RDONLY);
01165   if (fd < 0) 
01166     {
01167       dbus_set_error (error,
01168                       _dbus_error_from_errno (errno),
01169                       "Failed to open \"%s\": %s",
01170                       _dbus_string_get_const_data (&path),
01171                       _dbus_strerror (errno));
01172       goto fail;
01173     }
01174   
01175   if (!_dbus_read (fd, &cmdline, max_len))
01176     {
01177       dbus_set_error (error,
01178                       _dbus_error_from_errno (errno),
01179                       "Failed to read from \"%s\": %s",
01180                       _dbus_string_get_const_data (&path),
01181                       _dbus_strerror (errno));      
01182       goto fail;
01183     }
01184   
01185   if (!_dbus_close (fd, error))
01186     goto fail;
01187   
01188   string_squash_nonprintable (&cmdline);  
01189   
01190   if (!_dbus_string_copy (&cmdline, 0, str, _dbus_string_get_length (str)))
01191     goto oom;
01192   
01193   _dbus_string_free (&cmdline);  
01194   _dbus_string_free (&path);
01195   return TRUE;
01196 oom:
01197   _DBUS_SET_OOM (error);
01198 fail:
01199   _dbus_string_free (&cmdline);
01200   _dbus_string_free (&path);
01201   return FALSE;
01202 }