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 static int int_compare( int *a, int *b )
  32 {
  33         if ( *a == *b )
  34                 return 0;
  35         else if ( *a < *b )
  36                 return -1;
  37         else
  38                 return 1;
  39 }
  40
  41 void remove_duplicate_gids( int *num_groups, gid_t *groups )
  42 {
  43         int i;
  44         int count = *num_groups;
  45
  46         if ( *num_groups <= 0 || !groups )
  47                 return;
  48
  49         DEBUG(8,("remove_duplicate_gids: Enter %d gids\n", *num_groups));
  50
  51         qsort( groups, *num_groups, sizeof(gid_t), QSORT_CAST int_compare );
  52
  53         for ( i=1; i<count; ) {
  54                 if ( groups[i-1] == groups[i] ) {
  55                         memmove( &groups[i-1], &groups[i], (count - i + 1)*sizeof(gid_t) );
  56
  57                         /* decrement the total number of groups and do not increment
  58                            the loop counter */
  59                         count--;
  60                         continue;
  61                 }
  62                 i++;
  63         }
  64
  65         *num_groups = count;
  66
  67         DEBUG(8,("remove_duplicate_gids: Exit %d gids\n", *num_groups));
  68
  69         return;
  70 }
  71
  72 /*
  73   This is a *much* faster way of getting the list of groups for a user
  74   without changing the current supplementary group list. The old
  75   method used getgrent() which could take 20 minutes on a really big
  76   network with hundeds of thousands of groups and users. The new method
  77   takes a couple of seconds.
  78
  79   NOTE!! this function only works if it is called as root!
  80   */
  81
  82 static int getgrouplist_internals(const char *user, gid_t gid, gid_t *groups, int *grpcnt)
  83 {
  84         gid_t *gids_saved;
  85         int ret, ngrp_saved, num_gids;
  86
  87         if (non_root_mode()) {
  88                 *grpcnt = 0;
  89                 return 0;
  90         }
  91
  92         /* work out how many groups we need to save */
  93         ngrp_saved = getgroups(0, NULL);
  94         if (ngrp_saved == -1) {
  95                 /* this shouldn't happen */
  96                 return -1;
  97         }
  98
  99         gids_saved = SMB_MALLOC_ARRAY(gid_t, ngrp_saved+1);
 100         if (!gids_saved) {
 101                 errno = ENOMEM;
 102                 return -1;
 103         }
 104
 105         ngrp_saved = getgroups(ngrp_saved, gids_saved);
 106         if (ngrp_saved == -1) {
 107                 SAFE_FREE(gids_saved);
 108                 /* very strange! */
 109                 return -1;
 110         }
 111
 112         if (initgroups(user, gid) != 0) {
 113                 DEBUG(0, ("getgrouplist_internals: initgroups() failed!\n"));
 114                 SAFE_FREE(gids_saved);
 115                 return -1;
 116         }
 117
 118         /* this must be done to cope with systems that put the current egid in the
 119            return from getgroups() */
 120         save_re_gid();
 121         set_effective_gid(gid);
 122         setgid(gid);
 123
 124         num_gids = getgroups(0, NULL);
 125         if (num_gids == -1) {
 126                 SAFE_FREE(gids_saved);
 127                 /* very strange! */
 128                 return -1;
 129         }
 130
 131         if (num_gids + 1 > *grpcnt) {
 132                 *grpcnt = num_gids + 1;
 133                 ret = -1;
 134         } else {
 135                 ret = getgroups(*grpcnt - 1, &groups[1]);
 136                 if (ret < 0) {
 137                         SAFE_FREE(gids_saved);
 138                         /* very strange! */
 139                         return -1;
 140                 }
 141                 groups[0] = gid;
 142                 *grpcnt = ret + 1;
 143
 144                 /* remove any duplicates gids in the list */
 145                 remove_duplicate_gids( grpcnt, groups );
 146         }
 147
 148         restore_re_gid();
 149
 150         if (sys_setgroups(ngrp_saved, gids_saved) != 0) {
 151                 /* yikes! */
 152                 DEBUG(0,("ERROR: getgrouplist: failed to reset group list!\n"));
 153                 smb_panic("getgrouplist: failed to reset group list!\n");
 154                 free(gids_saved);
 155                 return -1;
 156         }
 157
 158         free(gids_saved);
 159         return ret;
 160 }
 161 #endif
 162
 163 static int sys_getgrouplist(const char *user, gid_t gid, gid_t *groups, int *grpcnt)
 164 {
 165         int retval;
 166
 167         DEBUG(10,("sys_getgrouplist: user [%s]\n", user));
 168
 169         /* see if we should disable winbindd lookups for local users */
 170         if (strchr(user, *lp_winbind_separator()) == NULL) {
 171                 if ( !winbind_off() )
 172                         DEBUG(0,("sys_getgroup_list: Insufficient environment space for %s\n",
 173                                 WINBINDD_DONT_ENV));
 174                 else
 175                         DEBUG(10,("sys_getgrouplist(): disabled winbindd for group lookup [user == %s]\n",
 176                                 user));
 177         }
 178
 179 #ifdef HAVE_GETGROUPLIST
 180         retval = getgrouplist(user, gid, groups, grpcnt);
 181 #else
 182         become_root();
 183         retval = getgrouplist_internals(user, gid, groups, grpcnt);
 184         unbecome_root();
 185 #endif
 186
 187         /* allow winbindd lookups */
 188         winbind_on();
 189
 190         return retval;
 191 }
 192
 193 BOOL getgroups_user(const char *user, gid_t primary_gid,
 194                     gid_t **ret_groups, size_t *p_ngroups)
 195 {
 196         size_t ngrp;
 197         int max_grp;
 198         gid_t *temp_groups;
 199         gid_t *groups;
 200         int i;
 201
 202         max_grp = groups_max();
 203         temp_groups = SMB_MALLOC_ARRAY(gid_t, max_grp);
 204         if (! temp_groups) {
 205                 return False;
 206         }
 207
 208         if (sys_getgrouplist(user, primary_gid, temp_groups, &max_grp) == -1) {
 209                 gid_t *groups_tmp;
 210
 211                 groups_tmp = SMB_REALLOC_ARRAY(temp_groups, gid_t, max_grp);
 212
 213                 if (!groups_tmp) {
 214                         SAFE_FREE(temp_groups);
 215                         return False;
 216                 }
 217                 temp_groups = groups_tmp;
 218
 219                 if (sys_getgrouplist(user, primary_gid,
 220                                      temp_groups, &max_grp) == -1) {
 221                         DEBUG(0, ("get_user_groups: failed to get the unix "
 222                                   "group list\n"));
 223                         SAFE_FREE(temp_groups);
 224                         return False;
 225                 }
 226         }
 227
 228         ngrp = 0;
 229         groups = NULL;
 230
 231         /* Add in primary group first */
 232         add_gid_to_array_unique(NULL, primary_gid, &groups, &ngrp);
 233
 234         for (i=0; i<max_grp; i++)
 235                 add_gid_to_array_unique(NULL, temp_groups[i], &groups, &ngrp);
 236
 237         *p_ngroups = ngrp;
 238         *ret_groups = groups;
 239         SAFE_FREE(temp_groups);
 240         return True;
 241 }
 242
 243 NTSTATUS pdb_default_enum_group_memberships(struct pdb_methods *methods,
 244                                             const char *username,
 245                                             gid_t primary_gid,
 246                                             DOM_SID **pp_sids,
 247                                             gid_t **pp_gids,
 248                                             size_t *p_num_groups)
 249 {
 250         size_t i;
 251
 252         if (!getgroups_user(username, primary_gid, pp_gids, p_num_groups)) {
 253                 return NT_STATUS_NO_SUCH_USER;
 254         }
 255
 256         if (*p_num_groups == 0) {
 257                 smb_panic("primary group missing");
 258         }
 259
 260         *pp_sids = SMB_MALLOC_ARRAY(DOM_SID, *p_num_groups);
 261
 262         if (*pp_sids == NULL) {
 263                 SAFE_FREE(pp_gids);
 264                 return NT_STATUS_NO_MEMORY;
 265         }
 266
 267         for (i=0; i<*p_num_groups; i++) {
 268                 if (!NT_STATUS_IS_OK(gid_to_sid(&(*pp_sids)[i], (*pp_gids)[i]))) {
 269                         DEBUG(1, ("get_user_groups: failed to convert "
 270                                   "gid %ld to a sid!\n",
 271                                   (long int)(*pp_gids)[i+1]));
 272                         SAFE_FREE(*pp_sids);
 273                         SAFE_FREE(*pp_gids);
 274                         return NT_STATUS_NO_SUCH_USER;
 275                 }
 276         }
 277
 278         return NT_STATUS_OK;
 279 }