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", get_pipe_name_from_iface(syntax)));
 114         }
 115
 116         /*
 117          * One more pipe is using this list.
 118          */
 119
 120         hl->pipe_ref_count++;
 121
 122         /*
 123          * Point this pipe at this list.
 124          */
 125
 126         p->pipe_handles = hl;
 127
 128         DEBUG(10,("init_pipe_handles: pipe_handles ref count = %lu for pipe %s\n",
 129                   (unsigned long)p->pipe_handles->pipe_ref_count,
 130                   get_pipe_name_from_iface(syntax)));
 131
 132         return True;
 133 }
 134
 135 /****************************************************************************
 136   find first available policy slot.  creates a policy handle for you.
 137
 138   If "data_ptr" is given, this must be a talloc'ed object, create_policy_hnd
 139   talloc_moves this into the handle. If the policy_hnd is closed,
 140   data_ptr is TALLOC_FREE()'ed
 141 ****************************************************************************/
 142
 143 static struct policy *create_policy_hnd_internal(pipes_struct *p,
 144                                                  struct policy_handle *hnd,
 145                                                  void *data_ptr)
 146 {
 147         static uint32 pol_hnd_low  = 0;
 148         static uint32 pol_hnd_high = 0;
 149         time_t t = time(NULL);
 150
 151         struct policy *pol;
 152
 153         if (p->pipe_handles->count > MAX_OPEN_POLS) {
 154                 DEBUG(0,("create_policy_hnd: ERROR: too many handles (%d) on this pipe.\n",
 155                                 (int)p->pipe_handles->count));
 156                 return NULL;
 157         }
 158
 159         pol = TALLOC_ZERO_P(NULL, struct policy);
 160         if (!pol) {
 161                 DEBUG(0,("create_policy_hnd: ERROR: out of memory!\n"));
 162                 return NULL;
 163         }
 164
 165         if (data_ptr != NULL) {
 166                 pol->data_ptr = talloc_move(pol, &data_ptr);
 167         }
 168
 169         pol_hnd_low++;
 170         if (pol_hnd_low == 0)
 171                 (pol_hnd_high)++;
 172
 173         SIVAL(&pol->pol_hnd.handle_type, 0 , 0);  /* first bit must be null */
 174         SIVAL(&pol->pol_hnd.uuid.time_low, 0 , pol_hnd_low ); /* second bit is incrementing */
 175         SSVAL(&pol->pol_hnd.uuid.time_mid, 0 , pol_hnd_high); /* second bit is incrementing */
 176         SSVAL(&pol->pol_hnd.uuid.time_hi_and_version, 0 , (pol_hnd_high>>16)); /* second bit is incrementing */
 177
 178         /* split the current time into two 16 bit values */
 179
 180         SSVAL(pol->pol_hnd.uuid.clock_seq, 0, (t>>16)); /* something random */
 181         SSVAL(pol->pol_hnd.uuid.node, 0, t); /* something random */
 182
 183         SIVAL(pol->pol_hnd.uuid.node, 2, sys_getpid()); /* something more random */
 184
 185         DLIST_ADD(p->pipe_handles->Policy, pol);
 186         p->pipe_handles->count++;
 187
 188         *hnd = pol->pol_hnd;
 189
 190         DEBUG(4,("Opened policy hnd[%d] ", (int)p->pipe_handles->count));
 191         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 192
 193         return pol;
 194 }
 195
 196 bool create_policy_hnd(pipes_struct *p, struct policy_handle *hnd,
 197                        void *data_ptr)
 198 {
 199         return create_policy_hnd_internal(p, hnd, data_ptr) != NULL;
 200 }
 201
 202 /****************************************************************************
 203   find policy by handle - internal version.
 204 ****************************************************************************/
 205
 206 static struct policy *find_policy_by_hnd_internal(pipes_struct *p,
 207                                                   const struct policy_handle *hnd,
 208                                                   void **data_p)
 209 {
 210         struct policy *pol;
 211         size_t i;
 212
 213         if (data_p)
 214                 *data_p = NULL;
 215
 216         for (i = 0, pol=p->pipe_handles->Policy;pol;pol=pol->next, i++) {
 217                 if (memcmp(&pol->pol_hnd, hnd, sizeof(*hnd)) == 0) {
 218                         DEBUG(4,("Found policy hnd[%d] ", (int)i));
 219                         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 220                         if (data_p)
 221                                 *data_p = pol->data_ptr;
 222                         return pol;
 223                 }
 224         }
 225
 226         DEBUG(4,("Policy not found: "));
 227         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 228
 229         p->bad_handle_fault_state = True;
 230
 231         return NULL;
 232 }
 233
 234 /****************************************************************************
 235   find policy by handle
 236 ****************************************************************************/
 237
 238 bool find_policy_by_hnd(pipes_struct *p, const struct policy_handle *hnd,
 239                         void **data_p)
 240 {
 241         return find_policy_by_hnd_internal(p, hnd, data_p) == NULL ? False : True;
 242 }
 243
 244 /****************************************************************************
 245   Close a policy.
 246 ****************************************************************************/
 247
 248 bool close_policy_hnd(pipes_struct *p, struct policy_handle *hnd)
 249 {
 250         struct policy *pol = find_policy_by_hnd_internal(p, hnd, NULL);
 251
 252         if (!pol) {
 253                 DEBUG(3,("Error closing policy\n"));
 254                 return False;
 255         }
 256
 257         DEBUG(3,("Closed policy\n"));
 258
 259         p->pipe_handles->count--;
 260
 261         DLIST_REMOVE(p->pipe_handles->Policy, pol);
 262
 263         TALLOC_FREE(pol);
 264
 265         return True;
 266 }
 267
 268 /****************************************************************************
 269  Close a pipe - free the handle list if it was the last pipe reference.
 270 ****************************************************************************/
 271
 272 void close_policy_by_pipe(pipes_struct *p)
 273 {
 274         p->pipe_handles->pipe_ref_count--;
 275
 276         if (p->pipe_handles->pipe_ref_count == 0) {
 277                 /*
 278                  * Last pipe open on this list - free the list.
 279                  */
 280                 while (p->pipe_handles->Policy)
 281                         close_policy_hnd(p, &p->pipe_handles->Policy->pol_hnd);
 282
 283                 p->pipe_handles->Policy = NULL;
 284                 p->pipe_handles->count = 0;
 285
 286                 SAFE_FREE(p->pipe_handles);
 287                 DEBUG(10,("close_policy_by_pipe: deleted handle list for "
 288                           "pipe %s\n", get_pipe_name_from_iface(&p->syntax)));
 289         }
 290 }
 291
 292 /*******************************************************************
 293 Shall we allow access to this rpc?  Currently this function
 294 implements the 'restrict anonymous' setting by denying access to
 295 anonymous users if the restrict anonymous level is > 0.  Further work
 296 will be checking a security descriptor to determine whether a user
 297 token has enough access to access the pipe.
 298 ********************************************************************/
 299
 300 bool pipe_access_check(pipes_struct *p)
 301 {
 302         /* Don't let anonymous users access this RPC if restrict
 303            anonymous > 0 */
 304
 305         if (lp_restrict_anonymous() > 0) {
 306
 307                 /* schannel, so we must be ok */
 308                 if (p->pipe_bound && (p->auth.auth_type == PIPE_AUTH_TYPE_SCHANNEL)) {
 309                         return True;
 310                 }
 311
 312                 if (p->server_info->guest) {
 313                         return False;
 314                 }
 315         }
 316
 317         return True;
 318 }
 319
 320 void *_policy_handle_create(struct pipes_struct *p, struct policy_handle *hnd,
 321                             uint32_t access_granted, size_t data_size,
 322                             const char *type, NTSTATUS *pstatus)
 323 {
 324         struct policy *pol;
 325         void *data;
 326
 327         if (p->pipe_handles->count > MAX_OPEN_POLS) {
 328                 DEBUG(0, ("policy_handle_create: ERROR: too many handles (%d) "
 329                           "on pipe %s.\n", (int)p->pipe_handles->count,
 330                           get_pipe_name_from_iface(&p->syntax)));
 331                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 332                 return NULL;
 333         }
 334
 335         data = talloc_size(talloc_tos(), data_size);
 336         if (data == NULL) {
 337                 *pstatus = NT_STATUS_NO_MEMORY;
 338                 return NULL;
 339         }
 340         talloc_set_name_const(data, type);
 341
 342         pol = create_policy_hnd_internal(p, hnd, data);
 343         if (pol == NULL) {
 344                 TALLOC_FREE(data);
 345                 *pstatus = NT_STATUS_NO_MEMORY;
 346                 return NULL;
 347         }
 348         pol->access_granted = access_granted;
 349         *pstatus = NT_STATUS_OK;
 350         return data;
 351 }
 352
 353 void *_policy_handle_find(struct pipes_struct *p,
 354                           const struct policy_handle *hnd,
 355                           uint32_t access_required,
 356                           uint32_t *paccess_granted,
 357                           const char *name, const char *location,
 358                           NTSTATUS *pstatus)
 359 {
 360         struct policy *pol;
 361         void *data;
 362
 363         pol = find_policy_by_hnd_internal(p, hnd, &data);
 364         if (pol == NULL) {
 365                 *pstatus = NT_STATUS_INVALID_HANDLE;
 366                 return NULL;
 367         }
 368         if (strcmp(name, talloc_get_name(data)) != 0) {
 369                 DEBUG(10, ("expected %s, got %s\n", name,
 370                            talloc_get_name(data)));
 371                 *pstatus = NT_STATUS_INVALID_HANDLE;
 372                 return NULL;
 373         }
 374         if ((access_required & pol->access_granted) != access_required) {
 375                 if (geteuid() == sec_initial_uid()) {
 376                         DEBUG(4, ("%s: ACCESS should be DENIED (granted: "
 377                                   "%#010x; required: %#010x)\n", location,
 378                                   pol->access_granted, access_required));
 379                         DEBUGADD(4,("but overwritten by euid == 0\n"));
 380                         goto okay;
 381                 }
 382                 DEBUG(2,("%s: ACCESS DENIED (granted: %#010x; required: "
 383                          "%#010x)\n", location, pol->access_granted,
 384                          access_required));
 385                 *pstatus = NT_STATUS_ACCESS_DENIED;
 386                 return NULL;
 387         }
 388
 389  okay:
 390         DEBUG(10, ("found handle of type %s\n", talloc_get_name(data)));
 391         if (paccess_granted != NULL) {
 392                 *paccess_granted = pol->access_granted;
 393         }
 394         *pstatus = NT_STATUS_OK;
 395         return data;
 396 }