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 policy {
  34         struct policy *next, *prev;
  35
  36         struct policy_handle pol_hnd;
  37
  38         uint32_t access_granted;
  39
  40         void *data_ptr;
  41 };
  42
  43 struct handle_list {
  44         struct policy *Policy;  /* List of policies. */
  45         size_t count;                   /* Current number of handles. */
  46         size_t pipe_ref_count;  /* Number of pipe handles referring to this list. */
  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(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_handle_list(pipes_struct *p, const struct ndr_syntax_id *syntax)
  79 {
  80         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 = SMB_MALLOC_P(struct handle_list);
 109                 if (hl == NULL) {
 110                         return false;
 111                 }
 112                 ZERO_STRUCTP(hl);
 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 policy *create_policy_hnd_internal(pipes_struct *p,
 147                                                  struct policy_handle *hnd,
 148                                                  void *data_ptr)
 149 {
 150         static uint32 pol_hnd_low  = 0;
 151         static uint32 pol_hnd_high = 0;
 152         time_t t = time(NULL);
 153
 154         struct policy *pol;
 155
 156         if (p->pipe_handles->count > MAX_OPEN_POLS) {
 157                 DEBUG(0,("create_policy_hnd: ERROR: too many handles (%d) on this pipe.\n",
 158                                 (int)p->pipe_handles->count));
 159                 return NULL;
 160         }
 161
 162         pol = TALLOC_ZERO_P(NULL, struct policy);
 163         if (!pol) {
 164                 DEBUG(0,("create_policy_hnd: ERROR: out of memory!\n"));
 165                 return NULL;
 166         }
 167
 168         if (data_ptr != NULL) {
 169                 pol->data_ptr = talloc_move(pol, &data_ptr);
 170         }
 171
 172         pol_hnd_low++;
 173         if (pol_hnd_low == 0)
 174                 (pol_hnd_high)++;
 175
 176         SIVAL(&pol->pol_hnd.handle_type, 0 , 0);  /* first bit must be null */
 177         SIVAL(&pol->pol_hnd.uuid.time_low, 0 , pol_hnd_low ); /* second bit is incrementing */
 178         SSVAL(&pol->pol_hnd.uuid.time_mid, 0 , pol_hnd_high); /* second bit is incrementing */
 179         SSVAL(&pol->pol_hnd.uuid.time_hi_and_version, 0 , (pol_hnd_high>>16)); /* second bit is incrementing */
 180
 181         /* split the current time into two 16 bit values */
 182
 183         SSVAL(pol->pol_hnd.uuid.clock_seq, 0, (t>>16)); /* something random */
 184         SSVAL(pol->pol_hnd.uuid.node, 0, t); /* something random */
 185
 186         SIVAL(pol->pol_hnd.uuid.node, 2, sys_getpid()); /* something more random */
 187
 188         DLIST_ADD(p->pipe_handles->Policy, pol);
 189         p->pipe_handles->count++;
 190
 191         *hnd = pol->pol_hnd;
 192
 193         DEBUG(4,("Opened policy hnd[%d] ", (int)p->pipe_handles->count));
 194         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 195
 196         return pol;
 197 }
 198
 199 bool create_policy_hnd(pipes_struct *p, struct policy_handle *hnd,
 200                        void *data_ptr)
 201 {
 202         return create_policy_hnd_internal(p, hnd, data_ptr) != NULL;
 203 }
 204
 205 /****************************************************************************
 206   find policy by handle - internal version.
 207 ****************************************************************************/
 208
 209 static struct policy *find_policy_by_hnd_internal(pipes_struct *p,
 210                                                   const struct policy_handle *hnd,
 211                                                   void **data_p)
 212 {
 213         struct policy *pol;
 214         size_t i;
 215
 216         if (data_p)
 217                 *data_p = NULL;
 218
 219         for (i = 0, pol=p->pipe_handles->Policy;pol;pol=pol->next, i++) {
 220                 if (memcmp(&pol->pol_hnd, hnd, sizeof(*hnd)) == 0) {
 221                         DEBUG(4,("Found policy hnd[%d] ", (int)i));
 222                         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 223                         if (data_p)
 224                                 *data_p = pol->data_ptr;
 225                         return pol;
 226                 }
 227         }
 228
 229         DEBUG(4,("Policy not found: "));
 230         dump_data(4, (uint8 *)hnd, sizeof(*hnd));
 231
 232         p->bad_handle_fault_state = True;
 233
 234         return NULL;
 235 }
 236
 237 /****************************************************************************
 238   find policy by handle
 239 ****************************************************************************/
 240
 241 bool find_policy_by_hnd(pipes_struct *p, const struct policy_handle *hnd,
 242                         void **data_p)
 243 {
 244         return find_policy_by_hnd_internal(p, hnd, data_p) == NULL ? False : True;
 245 }
 246
 247 /****************************************************************************
 248   Close a policy.
 249 ****************************************************************************/
 250
 251 bool close_policy_hnd(pipes_struct *p, struct policy_handle *hnd)
 252 {
 253         struct policy *pol = find_policy_by_hnd_internal(p, hnd, NULL);
 254
 255         if (!pol) {
 256                 DEBUG(3,("Error closing policy\n"));
 257                 return False;
 258         }
 259
 260         DEBUG(3,("Closed policy\n"));
 261
 262         p->pipe_handles->count--;
 263
 264         DLIST_REMOVE(p->pipe_handles->Policy, pol);
 265
 266         TALLOC_FREE(pol);
 267
 268         return True;
 269 }
 270
 271 /****************************************************************************
 272  Close a pipe - free the handle list if it was the last pipe reference.
 273 ****************************************************************************/
 274
 275 void close_policy_by_pipe(pipes_struct *p)
 276 {
 277         p->pipe_handles->pipe_ref_count--;
 278
 279         if (p->pipe_handles->pipe_ref_count == 0) {
 280                 /*
 281                  * Last pipe open on this list - free the list.
 282                  */
 283                 while (p->pipe_handles->Policy)
 284                         close_policy_hnd(p, &p->pipe_handles->Policy->pol_hnd);
 285
 286                 p->pipe_handles->Policy = NULL;
 287                 p->pipe_handles->count = 0;
 288
 289                 SAFE_FREE(p->pipe_handles);
 290                 DEBUG(10,("close_policy_by_pipe: deleted handle list for "
 291                           "pipe %s\n",
 292                           get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
 293         }
 294 }
 295
 296 /*******************************************************************
 297 Shall we allow access to this rpc?  Currently this function
 298 implements the 'restrict anonymous' setting by denying access to
 299 anonymous users if the restrict anonymous level is > 0.  Further work
 300 will be checking a security descriptor to determine whether a user
 301 token has enough access to access the pipe.
 302 ********************************************************************/
 303
 304 bool pipe_access_check(pipes_struct *p)
 305 {
 306         /* Don't let anonymous users access this RPC if restrict
 307            anonymous > 0 */
 308
 309         if (lp_restrict_anonymous() > 0) {
 310
 311                 /* schannel, so we must be ok */
 312                 if (p->pipe_bound && (p->auth.auth_type == PIPE_AUTH_TYPE_SCHANNEL)) {
 313                         return True;
 314                 }
 315
 316                 if (p->server_info->guest) {
 317                         return False;
 318                 }
 319         }
 320
 321         return True;
 322 }
 323
 324 void *_policy_handle_create(struct pipes_struct *p, struct policy_handle *hnd,
 325                             uint32_t access_granted, size_t data_size,
 326                             const char *type, NTSTATUS *pstatus)
 327 {
 328         struct policy *pol;
 329         void *data;
 330
 331         if (p->pipe_handles->count > MAX_OPEN_POLS) {
 332                 DEBUG(0, ("policy_handle_create: ERROR: too many handles (%d) "
 333                           "on pipe %s.\n", (int)p->pipe_handles->count,
 334                           get_pipe_name_from_syntax(talloc_tos(), &p->syntax)));
 335                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 336                 return NULL;
 337         }
 338
 339         data = talloc_size(talloc_tos(), data_size);
 340         if (data == NULL) {
 341                 *pstatus = NT_STATUS_NO_MEMORY;
 342                 return NULL;
 343         }
 344         talloc_set_name_const(data, type);
 345
 346         pol = create_policy_hnd_internal(p, hnd, data);
 347         if (pol == NULL) {
 348                 TALLOC_FREE(data);
 349                 *pstatus = NT_STATUS_NO_MEMORY;
 350                 return NULL;
 351         }
 352         pol->access_granted = access_granted;
 353         *pstatus = NT_STATUS_OK;
 354         return data;
 355 }
 356
 357 void *_policy_handle_find(struct pipes_struct *p,
 358                           const struct policy_handle *hnd,
 359                           uint32_t access_required,
 360                           uint32_t *paccess_granted,
 361                           const char *name, const char *location,
 362                           NTSTATUS *pstatus)
 363 {
 364         struct policy *pol;
 365         void *data;
 366
 367         pol = find_policy_by_hnd_internal(p, hnd, &data);
 368         if (pol == NULL) {
 369                 *pstatus = NT_STATUS_INVALID_HANDLE;
 370                 return NULL;
 371         }
 372         if (strcmp(name, talloc_get_name(data)) != 0) {
 373                 DEBUG(10, ("expected %s, got %s\n", name,
 374                            talloc_get_name(data)));
 375                 *pstatus = NT_STATUS_INVALID_HANDLE;
 376                 return NULL;
 377         }
 378         if ((access_required & pol->access_granted) != access_required) {
 379                 if (geteuid() == sec_initial_uid()) {
 380                         DEBUG(4, ("%s: ACCESS should be DENIED (granted: "
 381                                   "%#010x; required: %#010x)\n", location,
 382                                   pol->access_granted, access_required));
 383                         DEBUGADD(4,("but overwritten by euid == 0\n"));
 384                         goto okay;
 385                 }
 386                 DEBUG(2,("%s: ACCESS DENIED (granted: %#010x; required: "
 387                          "%#010x)\n", location, pol->access_granted,
 388                          access_required));
 389                 *pstatus = NT_STATUS_ACCESS_DENIED;
 390                 return NULL;
 391         }
 392
 393  okay:
 394         DEBUG(10, ("found handle of type %s\n", talloc_get_name(data)));
 395         if (paccess_granted != NULL) {
 396                 *paccess_granted = pol->access_granted;
 397         }
 398         *pstatus = NT_STATUS_OK;
 399         return data;
 400 }