source3/rpc_server/srv_lsa_hnd.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  RPC Pipe client / server routines
   4  *  Copyright (C) Andrew Tridgell              1992-1997,
   5  *  Copyright (C) Luke Kenneth Casson Leighton 1996-1997,
   6  *  Copyright (C) Jeremy Allison                           2001.
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 3 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include "includes.h"
  23
  24 #undef DBGC_CLASS
  25 #define DBGC_CLASS DBGC_RPC_SRV
  26
  27 /*
  28  * Handle database - stored per pipe.
  29  */
  30
  31 struct policy {
  32         struct policy *next, *prev;
  33
  34         struct policy_handle pol_hnd;
  35
  36         uint32_t access_granted;
  37
  38         void *data_ptr;
  39 };
  40
  41 struct handle_list {
  42         struct policy *Policy;  /* List of policies. */
  43         size_t count;                   /* Current number of handles. */
  44         size_t pipe_ref_count;  /* Number of pipe handles referring to this list. */
  45 };
  46
  47 /* This is the max handles across all instances of a pipe name. */
  48 #ifndef MAX_OPEN_POLS
  49 #define MAX_OPEN_POLS 2048
  50 #endif
  51
  52 /****************************************************************************
  53  Hack as handles need to be persisant over lsa pipe closes so long as a samr
  54  pipe is open. JRA.
  55 ****************************************************************************/
  56
  57 static bool is_samr_lsa_pipe(const struct ndr_syntax_id *syntax)
  58 {
  59         return (ndr_syntax_id_equal(syntax, &ndr_table_samr.syntax_id)
  60                 || ndr_syntax_id_equal(syntax, &ndr_table_lsarpc.syntax_id));
  61 }
  62
  63 size_t num_pipe_handles(struct handle_list *list)
  64 {
  65         if (list == NULL) {
  66                 return 0;
  67         }
  68         return list->count;
  69 }
  70
  71 /****************************************************************************
  72  Initialise a policy handle list on a pipe. Handle list is shared between all
  73  pipes of the same name.
  74 ****************************************************************************/
  75
  76 bool init_pipe_handle_list(pipes_struct *p, const struct ndr_syntax_id *syntax)
  77 {
  78         pipes_struct *plist;
  79         struct handle_list *hl;
  80
  81         for (plist = get_first_internal_pipe();
  82              plist;
  83              plist = get_next_internal_pipe(plist)) {
  84                 if (ndr_syntax_id_equal(syntax, &plist->syntax)) {
  85                         break;
  86                 }
  87                 if (is_samr_lsa_pipe(&plist->syntax)
  88                     && is_samr_lsa_pipe(syntax)) {
  89                         /*
  90                          * samr and lsa share a handle space (same process
  91                          * under Windows?)
  92                          */
  93                         break;
  94                 }
  95         }
  96
  97         if (plist != NULL) {
  98                 hl = plist->pipe_handles;
  99                 if (hl == NULL) {
 100                         return false;
 101                 }
 102         } else {
 103                 /*
 104                  * First open, we have to create the handle list
 105                  */
 106                 hl = SMB_MALLOC_P(struct handle_list);
 107                 if (hl == NULL) {
 108                         return false;
 109                 }
 110                 ZERO_STRUCTP(hl);
 111
 112                 DEBUG(10,("init_pipe_handles: created handle list for "
 113                           "pipe %s\n",
 114                           get_pipe_name_from_syntax(talloc_tos(), syntax)));
 115         }
 116
 117         /*
 118          * One more pipe is using this list.
 119          */
 120
 121         hl->pipe_ref_count++;
 122
 123         /*
 124          * Point this pipe at this list.
 125          */
 126
 127         p->pipe_handles = hl;
 128
 129         DEBUG(10,("init_pipe_handles: pipe_handles ref count = %lu for pipe %s\n",
 130                   (unsigned long)p->pipe_handles->pipe_ref_count,
 131                   get_pipe_name_from_syntax(talloc_tos(), syntax)));
 132
 133         return True;
 134 }
 135
 136 /****************************************************************************
 137   find first available policy slot.  creates a policy handle for you.
 138
 139   If "data_ptr" is given, this must be a talloc'ed object, create_policy_hnd
 140   talloc_moves this into the handle. If the policy_hnd is closed,
 141   data_ptr is TALLOC_FREE()'ed
 142 ****************************************************************************/
 143
 144 static struct policy *create_policy_hnd_internal(pipes_struct *p,
 145                                                  struct policy_handle *hnd,
 146                                                  void *data_ptr)
 147 {
 148         static uint32 pol_hnd_low  = 0;
 149         static uint32 pol_hnd_high = 0;
 150         time_t t = time(NULL);
 151
 152         struct policy *pol;
 153
 154         if (p->pipe_handles->count > MAX_OPEN_POLS) {
 155                 DEBUG(0,("create_policy_hnd: ERROR: too many handles (%d) on this pipe.\n",
 156                                 (int)p->pipe_handles->count));
 157                 return NULL;
 158         }
 159
 160         pol = TALLOC_ZERO_P(NULL, struct policy);
 161         if (!pol) {
 162                 DEBUG(0,("create_policy_hnd: ERROR: out of memory!\n"));
 163                 return NULL;
 164         }
 165
 166         if (data_ptr != NULL) {
 167                 pol->data_ptr = talloc_move(pol, &data_ptr);
 168         }
 169
 170         pol_hnd_low++;
 171         if (pol_hnd_low == 0)
 172                 (pol_hnd_high)++;
 173
 174         SIVAL(&pol->pol_hnd.handle_type, 0 , 0);  /* first bit must be null */
 175         SIVAL(&pol->pol_hnd.uuid.time_low, 0 , pol_hnd_low ); /* second bit is incrementing */
 176         SSVAL(&pol->pol_hnd.uuid.time_mid, 0 , pol_hnd_high); /* second bit is incrementing */
 177         SSVAL(&pol->pol_hnd.uuid.time_hi_and_version, 0 , (pol_hnd_high>>16)); /* second bit is incrementing */
 178
 179         /* split the current time into two 16 bit values */
 180
 181         SSVAL(pol->pol_hnd.uuid.clock_seq, 0, (t>>16)); /* something random */
 182         SSVAL(pol->pol_hnd.uuid.node, 0, t); /* something random */
 183
 184         SIVAL(pol->pol_hnd.uuid.node, 2, sys_getpid()); /* something more random */
 185
 186         DLIST_ADD(p->pipe_handles->Policy, pol);
 187         p->pipe_handles->count++;
 188
 189         *hnd = pol->pol_hnd;
 190
 191         DEBUG(4,("Opened policy hnd[%d] ", (int)p->pipe_handles->count));
 192         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 193
 194         return pol;
 195 }
 196
 197 bool create_policy_hnd(pipes_struct *p, struct policy_handle *hnd,
 198                        void *data_ptr)
 199 {
 200         return create_policy_hnd_internal(p, hnd, data_ptr) != NULL;
 201 }
 202
 203 /****************************************************************************
 204   find policy by handle - internal version.
 205 ****************************************************************************/
 206
 207 static struct policy *find_policy_by_hnd_internal(pipes_struct *p,
 208                                                   const struct policy_handle *hnd,
 209                                                   void **data_p)
 210 {
 211         struct policy *pol;
 212         size_t i;
 213
 214         if (data_p)
 215                 *data_p = NULL;
 216
 217         for (i = 0, pol=p->pipe_handles->Policy;pol;pol=pol->next, i++) {
 218                 if (memcmp(&pol->pol_hnd, hnd, sizeof(*hnd)) == 0) {
 219                         DEBUG(4,("Found policy hnd[%d] ", (int)i));
 220                         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 221                         if (data_p)
 222                                 *data_p = pol->data_ptr;
 223                         return pol;
 224                 }
 225         }
 226
 227         DEBUG(4,("Policy not found: "));
 228         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 229
 230         p->bad_handle_fault_state = True;
 231
 232         return NULL;
 233 }
 234
 235 /****************************************************************************
 236   find policy by handle
 237 ****************************************************************************/
 238
 239 bool find_policy_by_hnd(pipes_struct *p, const struct policy_handle *hnd,
 240                         void **data_p)
 241 {
 242         return find_policy_by_hnd_internal(p, hnd, data_p) == NULL ? False : True;
 243 }
 244
 245 /****************************************************************************
 246   Close a policy.
 247 ****************************************************************************/
 248
 249 bool close_policy_hnd(pipes_struct *p, struct policy_handle *hnd)
 250 {
 251         struct policy *pol = find_policy_by_hnd_internal(p, hnd, NULL);
 252
 253         if (!pol) {
 254                 DEBUG(3,("Error closing policy\n"));
 255                 return False;
 256         }
 257
 258         DEBUG(3,("Closed policy\n"));
 259
 260         p->pipe_handles->count--;
 261
 262         DLIST_REMOVE(p->pipe_handles->Policy, pol);
 263
 264         TALLOC_FREE(pol);
 265
 266         return True;
 267 }
 268
 269 /****************************************************************************
 270  Close a pipe - free the handle list if it was the last pipe reference.
 271 ****************************************************************************/
 272
 273 void close_policy_by_pipe(pipes_struct *p)
 274 {
 275         p->pipe_handles->pipe_ref_count--;
 276
 277         if (p->pipe_handles->pipe_ref_count == 0) {
 278                 /*
 279                  * Last pipe open on this list - free the list.
 280                  */
 281                 while (p->pipe_handles->Policy)
 282                         close_policy_hnd(p, &p->pipe_handles->Policy->pol_hnd);
 283
 284                 p->pipe_handles->Policy = NULL;
 285                 p->pipe_handles->count = 0;
 286
 287                 SAFE_FREE(p->pipe_handles);
 288                 DEBUG(10,("close_policy_by_pipe: deleted handle list for "
 289                           "pipe %s\n",
 290                           get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
 291         }
 292 }
 293
 294 /*******************************************************************
 295 Shall we allow access to this rpc?  Currently this function
 296 implements the 'restrict anonymous' setting by denying access to
 297 anonymous users if the restrict anonymous level is > 0.  Further work
 298 will be checking a security descriptor to determine whether a user
 299 token has enough access to access the pipe.
 300 ********************************************************************/
 301
 302 bool pipe_access_check(pipes_struct *p)
 303 {
 304         /* Don't let anonymous users access this RPC if restrict
 305            anonymous > 0 */
 306
 307         if (lp_restrict_anonymous() > 0) {
 308
 309                 /* schannel, so we must be ok */
 310                 if (p->pipe_bound && (p->auth.auth_type == PIPE_AUTH_TYPE_SCHANNEL)) {
 311                         return True;
 312                 }
 313
 314                 if (p->server_info->guest) {
 315                         return False;
 316                 }
 317         }
 318
 319         return True;
 320 }
 321
 322 void *_policy_handle_create(struct pipes_struct *p, struct policy_handle *hnd,
 323                             uint32_t access_granted, size_t data_size,
 324                             const char *type, NTSTATUS *pstatus)
 325 {
 326         struct policy *pol;
 327         void *data;
 328
 329         if (p->pipe_handles->count > MAX_OPEN_POLS) {
 330                 DEBUG(0, ("policy_handle_create: ERROR: too many handles (%d) "
 331                           "on pipe %s.\n", (int)p->pipe_handles->count,
 332                           get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
 333                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 334                 return NULL;
 335         }
 336
 337         data = talloc_size(talloc_tos(), data_size);
 338         if (data == NULL) {
 339                 *pstatus = NT_STATUS_NO_MEMORY;
 340                 return NULL;
 341         }
 342         talloc_set_name_const(data, type);
 343
 344         pol = create_policy_hnd_internal(p, hnd, data);
 345         if (pol == NULL) {
 346                 TALLOC_FREE(data);
 347                 *pstatus = NT_STATUS_NO_MEMORY;
 348                 return NULL;
 349         }
 350         pol->access_granted = access_granted;
 351         *pstatus = NT_STATUS_OK;
 352         return data;
 353 }
 354
 355 void *_policy_handle_find(struct pipes_struct *p,
 356                           const struct policy_handle *hnd,
 357                           uint32_t access_required,
 358                           uint32_t *paccess_granted,
 359                           const char *name, const char *location,
 360                           NTSTATUS *pstatus)
 361 {
 362         struct policy *pol;
 363         void *data;
 364
 365         pol = find_policy_by_hnd_internal(p, hnd, &data);
 366         if (pol == NULL) {
 367                 *pstatus = NT_STATUS_INVALID_HANDLE;
 368                 return NULL;
 369         }
 370         if (strcmp(name, talloc_get_name(data)) != 0) {
 371                 DEBUG(10, ("expected %s, got %s\n", name,
 372                            talloc_get_name(data)));
 373                 *pstatus = NT_STATUS_INVALID_HANDLE;
 374                 return NULL;
 375         }
 376         if ((access_required & pol->access_granted) != access_required) {
 377                 if (geteuid() == sec_initial_uid()) {
 378                         DEBUG(4, ("%s: ACCESS should be DENIED (granted: "
 379                                   "%#010x; required: %#010x)\n", location,
 380                                   pol->access_granted, access_required));
 381                         DEBUGADD(4,("but overwritten by euid == 0\n"));
 382                         goto okay;
 383                 }
 384                 DEBUG(2,("%s: ACCESS DENIED (granted: %#010x; required: "
 385                          "%#010x)\n", location, pol->access_granted,
 386                          access_required));
 387                 *pstatus = NT_STATUS_ACCESS_DENIED;
 388                 return NULL;
 389         }
 390
 391  okay:
 392         DEBUG(10, ("found handle of type %s\n", talloc_get_name(data)));
 393         if (paccess_granted != NULL) {
 394                 *paccess_granted = pol->access_granted;
 395         }
 396         *pstatus = NT_STATUS_OK;
 397         return data;
 398 }