source3/auth/server_info_sam.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Authentication utility functions
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Andrew Bartlett 2001
   6    Copyright (C) Jeremy Allison 2000-2001
   7    Copyright (C) Rafal Szczesniak 2002
   8    Copyright (C) Volker Lendecke 2006
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "smbd/globals.h"
  26 #include "../libcli/auth/libcli_auth.h"
  27
  28 #undef DBGC_CLASS
  29 #define DBGC_CLASS DBGC_AUTH
  30
  31
  32 /***************************************************************************
  33  Is the incoming username our own machine account ?
  34  If so, the connection is almost certainly from winbindd.
  35 ***************************************************************************/
  36
  37 static bool is_our_machine_account(const char *username)
  38 {
  39         bool ret;
  40         char *truncname = NULL;
  41         size_t ulen = strlen(username);
  42
  43         if (ulen == 0 || username[ulen-1] != '$') {
  44                 return false;
  45         }
  46         truncname = SMB_STRDUP(username);
  47         if (!truncname) {
  48                 return false;
  49         }
  50         truncname[ulen-1] = '\0';
  51         ret = strequal(truncname, global_myname());
  52         SAFE_FREE(truncname);
  53         return ret;
  54 }
  55
  56 /***************************************************************************
  57  Make (and fill) a user_info struct from a struct samu
  58 ***************************************************************************/
  59
  60 NTSTATUS make_server_info_sam(struct auth_serversupplied_info **server_info,
  61                               struct samu *sampass)
  62 {
  63         struct passwd *pwd;
  64         gid_t *gids;
  65         struct auth_serversupplied_info *result;
  66         const char *username = pdb_get_username(sampass);
  67         NTSTATUS status;
  68
  69         if ( !(result = make_server_info(NULL)) ) {
  70                 return NT_STATUS_NO_MEMORY;
  71         }
  72
  73         if ( !(pwd = getpwnam_alloc(result, username)) ) {
  74                 DEBUG(1, ("User %s in passdb, but getpwnam() fails!\n",
  75                           pdb_get_username(sampass)));
  76                 TALLOC_FREE(result);
  77                 return NT_STATUS_NO_SUCH_USER;
  78         }
  79
  80         status = samu_to_SamInfo3(result, sampass,
  81                                   global_myname(), &result->info3);
  82         if (!NT_STATUS_IS_OK(status)) {
  83                 TALLOC_FREE(result);
  84                 return status;
  85         }
  86
  87         result->unix_name = pwd->pw_name;
  88         /* Ensure that we keep pwd->pw_name, because we will free pwd below */
  89         talloc_steal(result, pwd->pw_name);
  90         result->utok.gid = pwd->pw_gid;
  91         result->utok.uid = pwd->pw_uid;
  92
  93         TALLOC_FREE(pwd);
  94
  95         result->sanitized_username = sanitize_username(result,
  96                                                        result->unix_name);
  97         if (result->sanitized_username == NULL) {
  98                 TALLOC_FREE(result);
  99                 return NT_STATUS_NO_MEMORY;
 100         }
 101
 102         if (IS_DC && is_our_machine_account(username)) {
 103                 /*
 104                  * Ensure for a connection from our own
 105                  * machine account (from winbindd on a DC)
 106                  * there are no supplementary groups.
 107                  * Prevents loops in calling gid_to_sid().
 108                  */
 109                 result->sids = NULL;
 110                 gids = NULL;
 111                 result->num_sids = 0;
 112
 113                 /*
 114                  * This is a hack of monstrous proportions.
 115                  * If we know it's winbindd talking to us,
 116                  * we know we must never recurse into it,
 117                  * so turn off contacting winbindd for this
 118                  * entire process. This will get fixed when
 119                  * winbindd doesn't need to talk to smbd on
 120                  * a PDC. JRA.
 121                  */
 122
 123                 (void)winbind_off();
 124
 125                 DEBUG(10, ("make_server_info_sam: our machine account %s "
 126                         "setting supplementary group list empty and "
 127                         "turning off winbindd requests.\n",
 128                         username));
 129         } else {
 130                 status = pdb_enum_group_memberships(result, sampass,
 131                                             &result->sids, &gids,
 132                                             &result->num_sids);
 133
 134                 if (!NT_STATUS_IS_OK(status)) {
 135                         DEBUG(10, ("pdb_enum_group_memberships failed: %s\n",
 136                                    nt_errstr(status)));
 137                         TALLOC_FREE(result);
 138                         return status;
 139                 }
 140         }
 141
 142         /* For now we throw away the gids and convert via sid_to_gid
 143          * later. This needs fixing, but I'd like to get the code straight and
 144          * simple first. */
 145
 146         TALLOC_FREE(gids);
 147
 148         DEBUG(5,("make_server_info_sam: made server info for user %s -> %s\n",
 149                  pdb_get_username(sampass), result->unix_name));
 150
 151         *server_info = result;
 152
 153         return NT_STATUS_OK;
 154 }