source/lib/system_smbd.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    system call wrapper interface.
   4    Copyright (C) Andrew Tridgell 2002
   5    Copyright (C) Andrew Barteltt 2002
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 /*
  23    This file may assume linkage with smbd - for things like become_root()
  24    etc.
  25 */
  26
  27 #include "includes.h"
  28
  29 #ifndef HAVE_GETGROUPLIST
  30 /*
  31   This is a *much* faster way of getting the list of groups for a user
  32   without changing the current supplemenrary group list. The old
  33   method used getgrent() which could take 20 minutes on a really big
  34   network with hundeds of thousands of groups and users. The new method
  35   takes a couple of seconds.
  36
  37   NOTE!! this function only works if it is called as root!
  38   */
  39 static int getgrouplist_internals(const char *user, gid_t gid, gid_t *groups, int *grpcnt)
  40 {
  41         gid_t *gids_saved;
  42         int ret, ngrp_saved, num_gids;
  43
  44         if (non_root_mode()) {
  45                 *grpcnt = 0;
  46                 return 0;
  47         }
  48
  49         /* work out how many groups we need to save */
  50         ngrp_saved = getgroups(0, NULL);
  51         if (ngrp_saved == -1) {
  52                 /* this shouldn't happen */
  53                 return -1;
  54         }
  55
  56         gids_saved = SMB_MALLOC_ARRAY(gid_t, ngrp_saved+1);
  57         if (!gids_saved) {
  58                 errno = ENOMEM;
  59                 return -1;
  60         }
  61
  62         ngrp_saved = getgroups(ngrp_saved, gids_saved);
  63         if (ngrp_saved == -1) {
  64                 SAFE_FREE(gids_saved);
  65                 /* very strange! */
  66                 return -1;
  67         }
  68
  69         if (initgroups(user, gid) != 0) {
  70                 DEBUG(0, ("getgrouplist_internals: initgroups() failed!\n"));
  71                 SAFE_FREE(gids_saved);
  72                 return -1;
  73         }
  74
  75         /* this must be done to cope with systems that put the current egid in the
  76            return from getgroups() */
  77         save_re_gid();
  78         set_effective_gid(gid);
  79         setgid(gid);
  80
  81         num_gids = getgroups(0, NULL);
  82         if (num_gids + 1 > *grpcnt) {
  83                 *grpcnt = num_gids + 1;
  84                 ret = -1;
  85         } else {
  86                 ret = getgroups(*grpcnt - 1, &groups[1]);
  87                 if (ret >= 0) {
  88                         groups[0] = gid;
  89                         *grpcnt = ret + 1;
  90                 }
  91
  92                 /* remove any duplicates gids in the list */
  93
  94                 remove_duplicate_gids( grpcnt, groups );
  95         }
  96
  97         restore_re_gid();
  98
  99         if (sys_setgroups(ngrp_saved, gids_saved) != 0) {
 100                 /* yikes! */
 101                 DEBUG(0,("ERROR: getgrouplist: failed to reset group list!\n"));
 102                 smb_panic("getgrouplist: failed to reset group list!\n");
 103                 free(gids_saved);
 104                 return -1;
 105         }
 106
 107         free(gids_saved);
 108         return ret;
 109 }
 110 #endif
 111
 112 static int sys_getgrouplist(const char *user, gid_t gid, gid_t *groups, int *grpcnt)
 113 {
 114         int retval;
 115
 116         DEBUG(10,("sys_getgrouplist: user [%s]\n", user));
 117
 118         /* see if we should disable winbindd lookups for local users */
 119         if (strchr(user, *lp_winbind_separator()) == NULL) {
 120                 if ( !winbind_off() )
 121                         DEBUG(0,("sys_getgroup_list: Insufficient environment space for %s\n",
 122                                 WINBINDD_DONT_ENV));
 123                 else
 124                         DEBUG(10,("sys_getgrouplist(): disabled winbindd for group lookup [user == %s]\n",
 125                                 user));
 126         }
 127
 128 #ifdef HAVE_GETGROUPLIST
 129         retval = getgrouplist(user, gid, groups, grpcnt);
 130 #else
 131         become_root();
 132         retval = getgrouplist_internals(user, gid, groups, grpcnt);
 133         unbecome_root();
 134 #endif
 135
 136         /* allow winbindd lookups */
 137         winbind_on();
 138
 139         return retval;
 140 }
 141
 142 BOOL getgroups_user(const char *user, gid_t primary_gid,
 143                     gid_t **ret_groups, int *ngroups)
 144 {
 145         int ngrp, max_grp;
 146         gid_t *temp_groups;
 147         gid_t *groups;
 148         int i;
 149
 150         max_grp = groups_max();
 151         temp_groups = SMB_MALLOC_ARRAY(gid_t, max_grp);
 152         if (! temp_groups) {
 153                 return False;
 154         }
 155
 156         if (sys_getgrouplist(user, primary_gid, temp_groups, &max_grp) == -1) {
 157
 158                 gid_t *groups_tmp;
 159
 160                 groups_tmp = SMB_REALLOC_ARRAY(temp_groups, gid_t, max_grp);
 161
 162                 if (!groups_tmp) {
 163                         SAFE_FREE(temp_groups);
 164                         return False;
 165                 }
 166                 temp_groups = groups_tmp;
 167
 168                 if (sys_getgrouplist(user, primary_gid,
 169                                      temp_groups, &max_grp) == -1) {
 170                         DEBUG(0, ("get_user_groups: failed to get the unix "
 171                                   "group list\n"));
 172                         SAFE_FREE(temp_groups);
 173                         return False;
 174                 }
 175         }
 176
 177         ngrp = 0;
 178         groups = NULL;
 179
 180         /* Add in primary group first */
 181         add_gid_to_array_unique(primary_gid, &groups, &ngrp);
 182
 183         for (i=0; i<max_grp; i++)
 184                 add_gid_to_array_unique(temp_groups[i], &groups, &ngrp);
 185
 186         *ngroups = ngrp;
 187         *ret_groups = groups;
 188         SAFE_FREE(temp_groups);
 189         return True;
 190 }
 191
 192 NTSTATUS pdb_default_enum_group_memberships(struct pdb_methods *methods,
 193                                             const char *username,
 194                                             gid_t primary_gid,
 195                                             DOM_SID **sids,
 196                                             gid_t **gids,
 197                                             int *num_groups)
 198 {
 199         int i;
 200
 201         if (!getgroups_user(username, primary_gid, gids, num_groups)) {
 202                 return NT_STATUS_NO_SUCH_USER;
 203         }
 204
 205         if (*num_groups == 0) {
 206                 smb_panic("primary group missing");
 207         }
 208
 209         *sids = SMB_MALLOC_ARRAY(DOM_SID, *num_groups);
 210
 211         if (*sids == NULL) {
 212                 SAFE_FREE(gids);
 213                 return NT_STATUS_NO_MEMORY;
 214         }
 215
 216         for (i=0; i<*num_groups; i++) {
 217                 if (!NT_STATUS_IS_OK(gid_to_sid(&(*sids)[i], (*gids)[i]))) {
 218                         DEBUG(1, ("get_user_groups: failed to convert "
 219                                   "gid %ld to a sid!\n",
 220                                   (long int)(*gids)[i+1]));
 221                         SAFE_FREE(*sids);
 222                         SAFE_FREE(*gids);
 223                         return NT_STATUS_NO_SUCH_USER;
 224                 }
 225         }
 226
 227         return NT_STATUS_OK;
 228 }