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 #include "auth.h"
  26 #include "ntdomain.h"
  27 #include "rpc_server/rpc_ncacn_np.h"
  28
  29 #undef DBGC_CLASS
  30 #define DBGC_CLASS DBGC_RPC_SRV
  31
  32 /*
  33  * Handle database - stored per pipe.
  34  */
  35
  36 struct dcesrv_handle {
  37         struct dcesrv_handle *prev, *next;
  38         struct policy_handle wire_handle;
  39         uint32_t access_granted;
  40         void *data;
  41 };
  42
  43 struct handle_list {
  44         struct dcesrv_handle *handles;  /* List of pipe handles. */
  45         size_t count;                   /* Current number of handles. */
  46         size_t pipe_ref_count;          /* Number of pipe handles referring
  47                                          * to this tree. */
  48 };
  49
  50 /* This is the max handles across all instances of a pipe name. */
  51 #ifndef MAX_OPEN_POLS
  52 #define MAX_OPEN_POLS 2048
  53 #endif
  54
  55 /****************************************************************************
  56  Hack as handles need to be persisant over lsa pipe closes so long as a samr
  57  pipe is open. JRA.
  58 ****************************************************************************/
  59
  60 static bool is_samr_lsa_pipe(const struct ndr_syntax_id *syntax)
  61 {
  62         return (ndr_syntax_id_equal(syntax, &ndr_table_samr.syntax_id)
  63                 || ndr_syntax_id_equal(syntax, &ndr_table_lsarpc.syntax_id));
  64 }
  65
  66 size_t num_pipe_handles(struct pipes_struct *p)
  67 {
  68         if (p->pipe_handles == NULL) {
  69                 return 0;
  70         }
  71         return p->pipe_handles->count;
  72 }
  73
  74 /****************************************************************************
  75  Initialise a policy handle list on a pipe. Handle list is shared between all
  76  pipes of the same name.
  77 ****************************************************************************/
  78
  79 bool init_pipe_handles(struct pipes_struct *p, const struct ndr_syntax_id *syntax)
  80 {
  81         struct pipes_struct *plist;
  82         struct handle_list *hl;
  83
  84         for (plist = get_first_internal_pipe();
  85              plist;
  86              plist = get_next_internal_pipe(plist)) {
  87                 if (ndr_syntax_id_equal(syntax, &plist->syntax)) {
  88                         break;
  89                 }
  90                 if (is_samr_lsa_pipe(&plist->syntax)
  91                     && is_samr_lsa_pipe(syntax)) {
  92                         /*
  93                          * samr and lsa share a handle space (same process
  94                          * under Windows?)
  95                          */
  96                         break;
  97                 }
  98         }
  99
 100         if (plist != NULL) {
 101                 hl = plist->pipe_handles;
 102                 if (hl == NULL) {
 103                         return false;
 104                 }
 105         } else {
 106                 /*
 107                  * First open, we have to create the handle list
 108                  */
 109                 hl = talloc_zero(NULL, struct handle_list);
 110                 if (hl == NULL) {
 111                         return false;
 112                 }
 113
 114                 DEBUG(10,("init_pipe_handle_list: created handle list for "
 115                           "pipe %s\n",
 116                           get_pipe_name_from_syntax(talloc_tos(), syntax)));
 117         }
 118
 119         /*
 120          * One more pipe is using this list.
 121          */
 122
 123         hl->pipe_ref_count++;
 124
 125         /*
 126          * Point this pipe at this list.
 127          */
 128
 129         p->pipe_handles = hl;
 130
 131         DEBUG(10,("init_pipe_handle_list: pipe_handles ref count = %lu for "
 132                   "pipe %s\n", (unsigned long)p->pipe_handles->pipe_ref_count,
 133                   get_pipe_name_from_syntax(talloc_tos(), syntax)));
 134
 135         return True;
 136 }
 137
 138 /****************************************************************************
 139   find first available policy slot.  creates a policy handle for you.
 140
 141   If "data_ptr" is given, this must be a talloc'ed object, create_policy_hnd
 142   talloc_moves this into the handle. If the policy_hnd is closed,
 143   data_ptr is TALLOC_FREE()'ed
 144 ****************************************************************************/
 145
 146 static struct dcesrv_handle *create_rpc_handle_internal(struct pipes_struct *p,
 147                                 struct policy_handle *hnd, void *data_ptr)
 148 {
 149         struct dcesrv_handle *rpc_hnd;
 150         static uint32 pol_hnd_low  = 0;
 151         static uint32 pol_hnd_high = 0;
 152         time_t t = time(NULL);
 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         rpc_hnd = talloc_zero(p->pipe_handles, struct dcesrv_handle);
 161         if (!rpc_hnd) {
 162                 DEBUG(0,("create_policy_hnd: ERROR: out of memory!\n"));
 163                 return NULL;
 164         }
 165
 166         if (data_ptr != NULL) {
 167                 rpc_hnd->data = talloc_move(rpc_hnd, &data_ptr);
 168         }
 169
 170         pol_hnd_low++;
 171         if (pol_hnd_low == 0) {
 172                 pol_hnd_high++;
 173         }
 174
 175         /* first bit must be null */
 176         SIVAL(&rpc_hnd->wire_handle.handle_type, 0 , 0);
 177
 178         /* second bit is incrementing */
 179         SIVAL(&rpc_hnd->wire_handle.uuid.time_low, 0 , pol_hnd_low);
 180         SSVAL(&rpc_hnd->wire_handle.uuid.time_mid, 0 , pol_hnd_high);
 181         SSVAL(&rpc_hnd->wire_handle.uuid.time_hi_and_version, 0, (pol_hnd_high >> 16));
 182
 183         /* split the current time into two 16 bit values */
 184
 185         /* something random */
 186         SSVAL(rpc_hnd->wire_handle.uuid.clock_seq, 0, (t >> 16));
 187         /* something random */
 188         SSVAL(rpc_hnd->wire_handle.uuid.node, 0, t);
 189         /* something more random */
 190         SIVAL(rpc_hnd->wire_handle.uuid.node, 2, sys_getpid());
 191
 192         DLIST_ADD(p->pipe_handles->handles, rpc_hnd);
 193         p->pipe_handles->count++;
 194
 195         *hnd = rpc_hnd->wire_handle;
 196
 197         DEBUG(4, ("Opened policy hnd[%d] ", (int)p->pipe_handles->count));
 198         dump_data(4, (uint8_t *)hnd, sizeof(*hnd));
 199
 200         return rpc_hnd;
 201 }
 202
 203 bool create_policy_hnd(struct pipes_struct *p, struct policy_handle *hnd,
 204                        void *data_ptr)
 205 {
 206         struct dcesrv_handle *rpc_hnd;
 207
 208         rpc_hnd = create_rpc_handle_internal(p, hnd, data_ptr);
 209         if (rpc_hnd == NULL) {
 210                 return false;
 211         }
 212         return true;
 213 }
 214
 215 /****************************************************************************
 216   find policy by handle - internal version.
 217 ****************************************************************************/
 218
 219 static struct dcesrv_handle *find_policy_by_hnd_internal(struct pipes_struct *p,
 220                                 const struct policy_handle *hnd, void **data_p)
 221 {
 222         struct dcesrv_handle *h;
 223         unsigned int count;
 224
 225         if (data_p) {
 226                 *data_p = NULL;
 227         }
 228
 229         count = 0;
 230         for (h = p->pipe_handles->handles; h != NULL; h = h->next) {
 231                 if (memcmp(&h->wire_handle, hnd, sizeof(*hnd)) == 0) {
 232                         DEBUG(4,("Found policy hnd[%u] ", count));
 233                         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 234                         if (data_p) {
 235                                 *data_p = h->data;
 236                         }
 237                         return h;
 238                 }
 239                 count++;
 240         }
 241
 242         DEBUG(4,("Policy not found: "));
 243         dump_data(4, (uint8_t *)hnd, sizeof(*hnd));
 244
 245         p->bad_handle_fault_state = true;
 246
 247         return NULL;
 248 }
 249
 250 /****************************************************************************
 251   find policy by handle
 252 ****************************************************************************/
 253
 254 bool find_policy_by_hnd(struct pipes_struct *p, const struct policy_handle *hnd,
 255                         void **data_p)
 256 {
 257         struct dcesrv_handle *rpc_hnd;
 258
 259         rpc_hnd = find_policy_by_hnd_internal(p, hnd, data_p);
 260         if (rpc_hnd == NULL) {
 261                 return false;
 262         }
 263         return true;
 264 }
 265
 266 /****************************************************************************
 267   Close a policy.
 268 ****************************************************************************/
 269
 270 bool close_policy_hnd(struct pipes_struct *p, struct policy_handle *hnd)
 271 {
 272         struct dcesrv_handle *rpc_hnd;
 273
 274         rpc_hnd = find_policy_by_hnd_internal(p, hnd, NULL);
 275
 276         if (rpc_hnd == NULL) {
 277                 DEBUG(3, ("Error closing policy (policy not found)\n"));
 278                 return false;
 279         }
 280
 281         DEBUG(3,("Closed policy\n"));
 282
 283         p->pipe_handles->count--;
 284
 285         DLIST_REMOVE(p->pipe_handles->handles, rpc_hnd);
 286         TALLOC_FREE(rpc_hnd);
 287
 288         return true;
 289 }
 290
 291 /****************************************************************************
 292  Close a pipe - free the handle set if it was the last pipe reference.
 293 ****************************************************************************/
 294
 295 void close_policy_by_pipe(struct pipes_struct *p)
 296 {
 297         p->pipe_handles->pipe_ref_count--;
 298
 299         if (p->pipe_handles->pipe_ref_count == 0) {
 300                 /*
 301                  * Last pipe open on this list - free the list.
 302                  */
 303                 TALLOC_FREE(p->pipe_handles);
 304
 305                 DEBUG(10,("close_policy_by_pipe: deleted handle list for "
 306                           "pipe %s\n",
 307                           get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
 308         }
 309 }
 310
 311 /*******************************************************************
 312 Shall we allow access to this rpc?  Currently this function
 313 implements the 'restrict anonymous' setting by denying access to
 314 anonymous users if the restrict anonymous level is > 0.  Further work
 315 will be checking a security descriptor to determine whether a user
 316 token has enough access to access the pipe.
 317 ********************************************************************/
 318
 319 bool pipe_access_check(struct pipes_struct *p)
 320 {
 321         /* Don't let anonymous users access this RPC if restrict
 322            anonymous > 0 */
 323
 324         if (lp_restrict_anonymous() > 0) {
 325
 326                 /* schannel, so we must be ok */
 327                 if (p->pipe_bound &&
 328                     (p->auth.auth_type == DCERPC_AUTH_TYPE_SCHANNEL)) {
 329                         return True;
 330                 }
 331
 332                 if (p->session_info->guest) {
 333                         return False;
 334                 }
 335         }
 336
 337         return True;
 338 }
 339
 340 void *_policy_handle_create(struct pipes_struct *p, struct policy_handle *hnd,
 341                             uint32_t access_granted, size_t data_size,
 342                             const char *type, NTSTATUS *pstatus)
 343 {
 344         struct dcesrv_handle *rpc_hnd;
 345         void *data;
 346
 347         if (p->pipe_handles->count > MAX_OPEN_POLS) {
 348                 DEBUG(0, ("policy_handle_create: ERROR: too many handles (%d) "
 349                           "on pipe %s.\n", (int)p->pipe_handles->count,
 350                           get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
 351                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 352                 return NULL;
 353         }
 354
 355         data = talloc_size(talloc_tos(), data_size);
 356         if (data == NULL) {
 357                 *pstatus = NT_STATUS_NO_MEMORY;
 358                 return NULL;
 359         }
 360         talloc_set_name_const(data, type);
 361
 362         rpc_hnd = create_rpc_handle_internal(p, hnd, data);
 363         if (rpc_hnd == NULL) {
 364                 TALLOC_FREE(data);
 365                 *pstatus = NT_STATUS_NO_MEMORY;
 366                 return NULL;
 367         }
 368         rpc_hnd->access_granted = access_granted;
 369         *pstatus = NT_STATUS_OK;
 370         return data;
 371 }
 372
 373 void *_policy_handle_find(struct pipes_struct *p,
 374                           const struct policy_handle *hnd,
 375                           uint32_t access_required,
 376                           uint32_t *paccess_granted,
 377                           const char *name, const char *location,
 378                           NTSTATUS *pstatus)
 379 {
 380         struct dcesrv_handle *rpc_hnd;
 381         void *data;
 382
 383         rpc_hnd = find_policy_by_hnd_internal(p, hnd, &data);
 384         if (rpc_hnd == NULL) {
 385                 *pstatus = NT_STATUS_INVALID_HANDLE;
 386                 return NULL;
 387         }
 388         if (strcmp(name, talloc_get_name(data)) != 0) {
 389                 DEBUG(10, ("expected %s, got %s\n", name,
 390                            talloc_get_name(data)));
 391                 *pstatus = NT_STATUS_INVALID_HANDLE;
 392                 return NULL;
 393         }
 394         if ((access_required & rpc_hnd->access_granted) != access_required) {
 395                 if (geteuid() == sec_initial_uid()) {
 396                         DEBUG(4, ("%s: ACCESS should be DENIED (granted: "
 397                                   "%#010x; required: %#010x)\n", location,
 398                                   rpc_hnd->access_granted, access_required));
 399                         DEBUGADD(4,("but overwritten by euid == 0\n"));
 400                         goto okay;
 401                 }
 402                 DEBUG(2,("%s: ACCESS DENIED (granted: %#010x; required: "
 403                          "%#010x)\n", location, rpc_hnd->access_granted,
 404                          access_required));
 405                 *pstatus = NT_STATUS_ACCESS_DENIED;
 406                 return NULL;
 407         }
 408
 409  okay:
 410         DEBUG(10, ("found handle of type %s\n", talloc_get_name(data)));
 411         if (paccess_granted != NULL) {
 412                 *paccess_granted = rpc_hnd->access_granted;
 413         }
 414         *pstatus = NT_STATUS_OK;
 415         return data;
 416 }