source3/rpc_server/rpc_handles.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 #include "../librpc/gen_ndr/ndr_lsa.h"
  24 #include "../librpc/gen_ndr/ndr_samr.h"
  25
  26 #undef DBGC_CLASS
  27 #define DBGC_CLASS DBGC_RPC_SRV
  28
  29 /*
  30  * Handle database - stored per pipe.
  31  */
  32
  33 struct dcesrv_handle {
  34         struct dcesrv_handle *prev, *next;
  35         struct policy_handle wire_handle;
  36         uint32_t access_granted;
  37         void *data;
  38 };
  39
  40 struct handle_list {
  41         struct dcesrv_handle *handles;  /* List of pipe handles. */
  42         size_t count;                   /* Current number of handles. */
  43         size_t pipe_ref_count;          /* Number of pipe handles referring
  44                                          * to this tree. */
  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 pipes_struct *p)
  64 {
  65         if (p->pipe_handles == NULL) {
  66                 return 0;
  67         }
  68         return p->pipe_handles->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_handles(struct pipes_struct *p, const struct ndr_syntax_id *syntax)
  77 {
  78         struct 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 = talloc_zero(NULL, struct handle_list);
 107                 if (hl == NULL) {
 108                         return false;
 109                 }
 110
 111                 DEBUG(10,("init_pipe_handle_list: created handle list for "
 112                           "pipe %s\n",
 113                           get_pipe_name_from_syntax(talloc_tos(), 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_handle_list: pipe_handles ref count = %lu for "
 129                   "pipe %s\n", (unsigned long)p->pipe_handles->pipe_ref_count,
 130                   get_pipe_name_from_syntax(talloc_tos(), 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 dcesrv_handle *create_rpc_handle_internal(struct pipes_struct *p,
 144                                 struct policy_handle *hnd, void *data_ptr)
 145 {
 146         struct dcesrv_handle *rpc_hnd;
 147         static uint32 pol_hnd_low  = 0;
 148         static uint32 pol_hnd_high = 0;
 149         time_t t = time(NULL);
 150
 151         if (p->pipe_handles->count > MAX_OPEN_POLS) {
 152                 DEBUG(0,("create_policy_hnd: ERROR: too many handles (%d) on this pipe.\n",
 153                                 (int)p->pipe_handles->count));
 154                 return NULL;
 155         }
 156
 157         rpc_hnd = talloc_zero(p->pipe_handles, struct dcesrv_handle);
 158         if (!rpc_hnd) {
 159                 DEBUG(0,("create_policy_hnd: ERROR: out of memory!\n"));
 160                 return NULL;
 161         }
 162
 163         if (data_ptr != NULL) {
 164                 rpc_hnd->data = talloc_move(rpc_hnd, &data_ptr);
 165         }
 166
 167         pol_hnd_low++;
 168         if (pol_hnd_low == 0) {
 169                 pol_hnd_high++;
 170         }
 171
 172         /* first bit must be null */
 173         SIVAL(&rpc_hnd->wire_handle.handle_type, 0 , 0);
 174
 175         /* second bit is incrementing */
 176         SIVAL(&rpc_hnd->wire_handle.uuid.time_low, 0 , pol_hnd_low);
 177         SSVAL(&rpc_hnd->wire_handle.uuid.time_mid, 0 , pol_hnd_high);
 178         SSVAL(&rpc_hnd->wire_handle.uuid.time_hi_and_version, 0, (pol_hnd_high >> 16));
 179
 180         /* split the current time into two 16 bit values */
 181
 182         /* something random */
 183         SSVAL(rpc_hnd->wire_handle.uuid.clock_seq, 0, (t >> 16));
 184         /* something random */
 185         SSVAL(rpc_hnd->wire_handle.uuid.node, 0, t);
 186         /* something more random */
 187         SIVAL(rpc_hnd->wire_handle.uuid.node, 2, sys_getpid());
 188
 189         DLIST_ADD(p->pipe_handles->handles, rpc_hnd);
 190         p->pipe_handles->count++;
 191
 192         *hnd = rpc_hnd->wire_handle;
 193
 194         DEBUG(4, ("Opened policy hnd[%d] ", (int)p->pipe_handles->count));
 195         dump_data(4, (uint8_t *)hnd, sizeof(*hnd));
 196
 197         return rpc_hnd;
 198 }
 199
 200 bool create_policy_hnd(struct pipes_struct *p, struct policy_handle *hnd,
 201                        void *data_ptr)
 202 {
 203         struct dcesrv_handle *rpc_hnd;
 204
 205         rpc_hnd = create_rpc_handle_internal(p, hnd, data_ptr);
 206         if (rpc_hnd == NULL) {
 207                 return false;
 208         }
 209         return true;
 210 }
 211
 212 /****************************************************************************
 213   find policy by handle - internal version.
 214 ****************************************************************************/
 215
 216 static struct dcesrv_handle *find_policy_by_hnd_internal(struct pipes_struct *p,
 217                                 const struct policy_handle *hnd, void **data_p)
 218 {
 219         struct dcesrv_handle *h;
 220         unsigned int count;
 221
 222         if (data_p) {
 223                 *data_p = NULL;
 224         }
 225
 226         count = 0;
 227         for (h = p->pipe_handles->handles; h != NULL; h = h->next) {
 228                 if (memcmp(&h->wire_handle, hnd, sizeof(*hnd)) == 0) {
 229                         DEBUG(4,("Found policy hnd[%u] ", count));
 230                         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 231                         if (data_p) {
 232                                 *data_p = h->data;
 233                         }
 234                         return h;
 235                 }
 236                 count++;
 237         }
 238
 239         DEBUG(4,("Policy not found: "));
 240         dump_data(4, (uint8_t *)hnd, sizeof(*hnd));
 241
 242         p->bad_handle_fault_state = true;
 243
 244         return NULL;
 245 }
 246
 247 /****************************************************************************
 248   find policy by handle
 249 ****************************************************************************/
 250
 251 bool find_policy_by_hnd(struct pipes_struct *p, const struct policy_handle *hnd,
 252                         void **data_p)
 253 {
 254         struct dcesrv_handle *rpc_hnd;
 255
 256         rpc_hnd = find_policy_by_hnd_internal(p, hnd, data_p);
 257         if (rpc_hnd == NULL) {
 258                 return false;
 259         }
 260         return true;
 261 }
 262
 263 /****************************************************************************
 264   Close a policy.
 265 ****************************************************************************/
 266
 267 bool close_policy_hnd(struct pipes_struct *p, struct policy_handle *hnd)
 268 {
 269         struct dcesrv_handle *rpc_hnd;
 270
 271         rpc_hnd = find_policy_by_hnd_internal(p, hnd, NULL);
 272
 273         if (rpc_hnd == NULL) {
 274                 DEBUG(3, ("Error closing policy (policy not found)\n"));
 275                 return false;
 276         }
 277
 278         DEBUG(3,("Closed policy\n"));
 279
 280         p->pipe_handles->count--;
 281
 282         DLIST_REMOVE(p->pipe_handles->handles, rpc_hnd);
 283         TALLOC_FREE(rpc_hnd);
 284
 285         return true;
 286 }
 287
 288 /****************************************************************************
 289  Close a pipe - free the handle set if it was the last pipe reference.
 290 ****************************************************************************/
 291
 292 void close_policy_by_pipe(struct pipes_struct *p)
 293 {
 294         p->pipe_handles->pipe_ref_count--;
 295
 296         if (p->pipe_handles->pipe_ref_count == 0) {
 297                 /*
 298                  * Last pipe open on this list - free the list.
 299                  */
 300                 TALLOC_FREE(p->pipe_handles);
 301
 302                 DEBUG(10,("close_policy_by_pipe: deleted handle list for "
 303                           "pipe %s\n",
 304                           get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
 305         }
 306 }
 307
 308 /*******************************************************************
 309 Shall we allow access to this rpc?  Currently this function
 310 implements the 'restrict anonymous' setting by denying access to
 311 anonymous users if the restrict anonymous level is > 0.  Further work
 312 will be checking a security descriptor to determine whether a user
 313 token has enough access to access the pipe.
 314 ********************************************************************/
 315
 316 bool pipe_access_check(struct pipes_struct *p)
 317 {
 318         /* Don't let anonymous users access this RPC if restrict
 319            anonymous > 0 */
 320
 321         if (lp_restrict_anonymous() > 0) {
 322
 323                 /* schannel, so we must be ok */
 324                 if (p->pipe_bound &&
 325                     (p->auth.auth_type == DCERPC_AUTH_TYPE_SCHANNEL)) {
 326                         return True;
 327                 }
 328
 329                 if (p->server_info->guest) {
 330                         return False;
 331                 }
 332         }
 333
 334         return True;
 335 }
 336
 337 void *_policy_handle_create(struct pipes_struct *p, struct policy_handle *hnd,
 338                             uint32_t access_granted, size_t data_size,
 339                             const char *type, NTSTATUS *pstatus)
 340 {
 341         struct dcesrv_handle *rpc_hnd;
 342         void *data;
 343
 344         if (p->pipe_handles->count > MAX_OPEN_POLS) {
 345                 DEBUG(0, ("policy_handle_create: ERROR: too many handles (%d) "
 346                           "on pipe %s.\n", (int)p->pipe_handles->count,
 347                           get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
 348                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 349                 return NULL;
 350         }
 351
 352         data = talloc_size(talloc_tos(), data_size);
 353         if (data == NULL) {
 354                 *pstatus = NT_STATUS_NO_MEMORY;
 355                 return NULL;
 356         }
 357         talloc_set_name_const(data, type);
 358
 359         rpc_hnd = create_rpc_handle_internal(p, hnd, data);
 360         if (rpc_hnd == NULL) {
 361                 TALLOC_FREE(data);
 362                 *pstatus = NT_STATUS_NO_MEMORY;
 363                 return NULL;
 364         }
 365         rpc_hnd->access_granted = access_granted;
 366         *pstatus = NT_STATUS_OK;
 367         return data;
 368 }
 369
 370 void *_policy_handle_find(struct pipes_struct *p,
 371                           const struct policy_handle *hnd,
 372                           uint32_t access_required,
 373                           uint32_t *paccess_granted,
 374                           const char *name, const char *location,
 375                           NTSTATUS *pstatus)
 376 {
 377         struct dcesrv_handle *rpc_hnd;
 378         void *data;
 379
 380         rpc_hnd = find_policy_by_hnd_internal(p, hnd, &data);
 381         if (rpc_hnd == NULL) {
 382                 *pstatus = NT_STATUS_INVALID_HANDLE;
 383                 return NULL;
 384         }
 385         if (strcmp(name, talloc_get_name(data)) != 0) {
 386                 DEBUG(10, ("expected %s, got %s\n", name,
 387                            talloc_get_name(data)));
 388                 *pstatus = NT_STATUS_INVALID_HANDLE;
 389                 return NULL;
 390         }
 391         if ((access_required & rpc_hnd->access_granted) != access_required) {
 392                 if (geteuid() == sec_initial_uid()) {
 393                         DEBUG(4, ("%s: ACCESS should be DENIED (granted: "
 394                                   "%#010x; required: %#010x)\n", location,
 395                                   rpc_hnd->access_granted, access_required));
 396                         DEBUGADD(4,("but overwritten by euid == 0\n"));
 397                         goto okay;
 398                 }
 399                 DEBUG(2,("%s: ACCESS DENIED (granted: %#010x; required: "
 400                          "%#010x)\n", location, rpc_hnd->access_granted,
 401                          access_required));
 402                 *pstatus = NT_STATUS_ACCESS_DENIED;
 403                 return NULL;
 404         }
 405
 406  okay:
 407         DEBUG(10, ("found handle of type %s\n", talloc_get_name(data)));
 408         if (paccess_granted != NULL) {
 409                 *paccess_granted = rpc_hnd->access_granted;
 410         }
 411         *pstatus = NT_STATUS_OK;
 412         return data;
 413 }