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