source3/smbd/uid.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    uid/user handling
   4    Copyright (C) Andrew Tridgell 1992-1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "system/passwd.h"
  22 #include "smbd/smbd.h"
  23 #include "smbd/globals.h"
  24 #include "source3/smbd/smbXsrv_session.h"
  25 #include "../librpc/gen_ndr/netlogon.h"
  26 #include "libcli/security/security.h"
  27 #include "passdb/lookup_sid.h"
  28 #include "auth.h"
  29 #include "../auth/auth_util.h"
  30 #include "source3/lib/substitute.h"
  31
  32 /* what user is current? */
  33 extern struct current_user current_user;
  34
  35 /****************************************************************************
  36  Become the guest user without changing the security context stack.
  37 ****************************************************************************/
  38
  39 bool change_to_guest(void)
  40 {
  41         struct passwd *pass;
  42
  43         pass = Get_Pwnam_alloc(talloc_tos(), lp_guest_account());
  44         if (!pass) {
  45                 return false;
  46         }
  47
  48 #ifdef AIX
  49         /* MWW: From AIX FAQ patch to WU-ftpd: call initgroups before
  50            setting IDs */
  51         initgroups(pass->pw_name, pass->pw_gid);
  52 #endif
  53
  54         set_sec_ctx(pass->pw_uid, pass->pw_gid, 0, NULL, NULL);
  55
  56         current_user.conn = NULL;
  57         current_user.vuid = UID_FIELD_INVALID;
  58
  59         TALLOC_FREE(pass);
  60
  61         return true;
  62 }
  63
  64 /****************************************************************************
  65  talloc free the conn->session_info if not used in the vuid cache.
  66 ****************************************************************************/
  67
  68 static void free_conn_session_info_if_unused(connection_struct *conn)
  69 {
  70         unsigned int i;
  71
  72         for (i = 0; i < VUID_CACHE_SIZE; i++) {
  73                 struct vuid_cache_entry *ent;
  74                 ent = &conn->vuid_cache->array[i];
  75                 if (ent->vuid != UID_FIELD_INVALID &&
  76                                 conn->session_info == ent->session_info) {
  77                         return;
  78                 }
  79         }
  80         /* Not used, safe to free. */
  81         TALLOC_FREE(conn->session_info);
  82 }
  83
  84 /****************************************************************************
  85   Setup the share access mask for a connection.
  86 ****************************************************************************/
  87
  88 static uint32_t create_share_access_mask(int snum,
  89                                 bool readonly_share,
  90                                 const struct security_token *token)
  91 {
  92         uint32_t share_access = 0;
  93
  94         share_access_check(token,
  95                         lp_const_servicename(snum),
  96                         MAXIMUM_ALLOWED_ACCESS,
  97                         &share_access);
  98
  99         if (readonly_share) {
 100                 share_access &=
 101                         ~(SEC_FILE_WRITE_DATA | SEC_FILE_APPEND_DATA |
 102                           SEC_FILE_WRITE_EA | SEC_FILE_WRITE_ATTRIBUTE |
 103                           SEC_DIR_DELETE_CHILD );
 104         }
 105
 106         if (security_token_has_privilege(token, SEC_PRIV_SECURITY)) {
 107                 share_access |= SEC_FLAG_SYSTEM_SECURITY;
 108         }
 109         if (security_token_has_privilege(token, SEC_PRIV_RESTORE)) {
 110                 share_access |= SEC_RIGHTS_PRIV_RESTORE;
 111         }
 112         if (security_token_has_privilege(token, SEC_PRIV_BACKUP)) {
 113                 share_access |= SEC_RIGHTS_PRIV_BACKUP;
 114         }
 115         if (security_token_has_privilege(token, SEC_PRIV_TAKE_OWNERSHIP)) {
 116                 share_access |= SEC_STD_WRITE_OWNER;
 117         }
 118
 119         return share_access;
 120 }
 121
 122 /*******************************************************************
 123  Calculate access mask and if this user can access this share.
 124 ********************************************************************/
 125
 126 NTSTATUS check_user_share_access(connection_struct *conn,
 127                                 const struct auth_session_info *session_info,
 128                                 uint32_t *p_share_access,
 129                                 bool *p_readonly_share)
 130 {
 131         int snum = SNUM(conn);
 132         uint32_t share_access = 0;
 133         bool readonly_share = false;
 134
 135         if (!user_ok_token(session_info->unix_info->unix_name,
 136                            session_info->info->domain_name,
 137                            session_info->security_token, snum)) {
 138                 return NT_STATUS_ACCESS_DENIED;
 139         }
 140
 141         readonly_share = is_share_read_only_for_token(
 142                 session_info->unix_info->unix_name,
 143                 session_info->info->domain_name,
 144                 session_info->security_token,
 145                 conn);
 146
 147         share_access = create_share_access_mask(snum,
 148                                         readonly_share,
 149                                         session_info->security_token);
 150
 151         if ((share_access & (FILE_READ_DATA|FILE_WRITE_DATA)) == 0) {
 152                 /* No access, read or write. */
 153                 DBG_NOTICE("user %s connection to %s denied due to share "
 154                          "security descriptor.\n",
 155                          session_info->unix_info->unix_name,
 156                          lp_const_servicename(snum));
 157                 return NT_STATUS_ACCESS_DENIED;
 158         }
 159
 160         if (!readonly_share &&
 161             !(share_access & FILE_WRITE_DATA)) {
 162                 /* smb.conf allows r/w, but the security descriptor denies
 163                  * write. Fall back to looking at readonly. */
 164                 readonly_share = true;
 165                 DBG_INFO("falling back to read-only access-evaluation due to "
 166                          "security descriptor\n");
 167         }
 168
 169         *p_share_access = share_access;
 170         *p_readonly_share = readonly_share;
 171
 172         return NT_STATUS_OK;
 173 }
 174
 175 /*******************************************************************
 176  Check if a username is OK.
 177
 178  This sets up conn->session_info with a copy related to this vuser that
 179  later code can then mess with.
 180 ********************************************************************/
 181
 182 static bool check_user_ok(connection_struct *conn,
 183                         uint64_t vuid,
 184                         const struct auth_session_info *session_info,
 185                         int snum)
 186 {
 187         unsigned int i;
 188         bool readonly_share = false;
 189         bool admin_user = false;
 190         struct vuid_cache_entry *ent = NULL;
 191         uint32_t share_access = 0;
 192         NTSTATUS status;
 193
 194         for (i=0; i<VUID_CACHE_SIZE; i++) {
 195                 ent = &conn->vuid_cache->array[i];
 196                 if (ent->vuid == vuid) {
 197                         if (vuid == UID_FIELD_INVALID) {
 198                                 /*
 199                                  * Slow path, we don't care
 200                                  * about the array traversal.
 201                                 */
 202                                 continue;
 203                         }
 204                         free_conn_session_info_if_unused(conn);
 205                         conn->session_info = ent->session_info;
 206                         conn->read_only = ent->read_only;
 207                         conn->share_access = ent->share_access;
 208                         conn->vuid = ent->vuid;
 209                         return(True);
 210                 }
 211         }
 212
 213         status = check_user_share_access(conn,
 214                                         session_info,
 215                                         &share_access,
 216                                         &readonly_share);
 217         if (!NT_STATUS_IS_OK(status)) {
 218                 return false;
 219         }
 220
 221         admin_user = token_contains_name_in_list(
 222                 session_info->unix_info->unix_name,
 223                 session_info->info->domain_name,
 224                 NULL, session_info->security_token, lp_admin_users(snum));
 225
 226         ent = &conn->vuid_cache->array[conn->vuid_cache->next_entry];
 227
 228         conn->vuid_cache->next_entry =
 229                 (conn->vuid_cache->next_entry + 1) % VUID_CACHE_SIZE;
 230
 231         TALLOC_FREE(ent->session_info);
 232
 233         /*
 234          * If force_user was set, all session_info's are based on the same
 235          * username-based faked one.
 236          */
 237
 238         ent->session_info = copy_session_info(
 239                 conn, conn->force_user ? conn->session_info : session_info);
 240
 241         if (ent->session_info == NULL) {
 242                 ent->vuid = UID_FIELD_INVALID;
 243                 return false;
 244         }
 245
 246         if (admin_user) {
 247                 DEBUG(2,("check_user_ok: user %s is an admin user. "
 248                         "Setting uid as %d\n",
 249                         ent->session_info->unix_info->unix_name,
 250                         sec_initial_uid() ));
 251                 ent->session_info->unix_token->uid = sec_initial_uid();
 252         }
 253
 254         /*
 255          * It's actually OK to call check_user_ok() with
 256          * vuid == UID_FIELD_INVALID as called from become_user_by_session().
 257          * All this will do is throw away one entry in the cache.
 258          */
 259
 260         ent->vuid = vuid;
 261         ent->read_only = readonly_share;
 262         ent->share_access = share_access;
 263         free_conn_session_info_if_unused(conn);
 264         conn->session_info = ent->session_info;
 265         conn->vuid = ent->vuid;
 266         if (vuid == UID_FIELD_INVALID) {
 267                 /*
 268                  * Not strictly needed, just make it really
 269                  * clear this entry is actually an unused one.
 270                  */
 271                 ent->read_only = false;
 272                 ent->share_access = 0;
 273                 ent->session_info = NULL;
 274         }
 275
 276         conn->read_only = readonly_share;
 277         conn->share_access = share_access;
 278
 279         return(True);
 280 }
 281
 282 static void print_impersonation_info(connection_struct *conn)
 283 {
 284         struct smb_filename *cwdfname = NULL;
 285
 286         if (!CHECK_DEBUGLVL(DBGLVL_INFO)) {
 287                 return;
 288         }
 289
 290         cwdfname = vfs_GetWd(talloc_tos(), conn);
 291         if (cwdfname == NULL) {
 292                 return;
 293         }
 294
 295         DBG_INFO("Impersonated user: uid=(%d,%d), gid=(%d,%d), cwd=[%s]\n",
 296                  (int)getuid(),
 297                  (int)geteuid(),
 298                  (int)getgid(),
 299                  (int)getegid(),
 300                  cwdfname->base_name);
 301         TALLOC_FREE(cwdfname);
 302 }
 303
 304 /****************************************************************************
 305  Become the user of a connection number without changing the security context
 306  stack, but modify the current_user entries.
 307 ****************************************************************************/
 308
 309 static bool change_to_user_impersonate(connection_struct *conn,
 310                                        const struct auth_session_info *session_info,
 311                                        uint64_t vuid)
 312 {
 313         const struct loadparm_substitution *lp_sub =
 314                 loadparm_s3_global_substitution();
 315         int snum;
 316         gid_t gid;
 317         uid_t uid;
 318         const char *force_group_name;
 319         char group_c;
 320         int num_groups = 0;
 321         gid_t *group_list = NULL;
 322         bool ok;
 323
 324         if ((current_user.conn == conn) &&
 325             (current_user.vuid == vuid) &&
 326             (current_user.ut.uid == session_info->unix_token->uid))
 327         {
 328                 DBG_INFO("Skipping user change - already user\n");
 329                 return true;
 330         }
 331
 332         set_current_user_info(session_info->unix_info->sanitized_username,
 333                               session_info->unix_info->unix_name,
 334                               session_info->info->domain_name);
 335
 336         snum = SNUM(conn);
 337
 338         ok = check_user_ok(conn, vuid, session_info, snum);
 339         if (!ok) {
 340                 DBG_WARNING("SMB user %s (unix user %s) "
 341                          "not permitted access to share %s.\n",
 342                          session_info->unix_info->sanitized_username,
 343                          session_info->unix_info->unix_name,
 344                          lp_const_servicename(snum));
 345                 return false;
 346         }
 347
 348         uid = conn->session_info->unix_token->uid;
 349         gid = conn->session_info->unix_token->gid;
 350         num_groups = conn->session_info->unix_token->ngroups;
 351         group_list  = conn->session_info->unix_token->groups;
 352
 353         /*
 354          * See if we should force group for this service. If so this overrides
 355          * any group set in the force user code.
 356          */
 357         force_group_name = lp_force_group(talloc_tos(), lp_sub, snum);
 358         group_c = *force_group_name;
 359
 360         if ((group_c != '\0') && (conn->force_group_gid == (gid_t)-1)) {
 361                 /*
 362                  * This can happen if "force group" is added to a
 363                  * share definition whilst an existing connection
 364                  * to that share exists. In that case, don't change
 365                  * the existing credentials for force group, only
 366                  * do so for new connections.
 367                  *
 368                  * BUG: https://bugzilla.samba.org/show_bug.cgi?id=13690
 369                  */
 370                 DBG_INFO("Not forcing group %s on existing connection to "
 371                         "share %s for SMB user %s (unix user %s)\n",
 372                         force_group_name,
 373                         lp_const_servicename(snum),
 374                         session_info->unix_info->sanitized_username,
 375                         session_info->unix_info->unix_name);
 376         }
 377
 378         if((group_c != '\0') && (conn->force_group_gid != (gid_t)-1)) {
 379                 /*
 380                  * Only force group for connections where
 381                  * conn->force_group_gid has already been set
 382                  * to the correct value (i.e. the connection
 383                  * happened after the 'force group' definition
 384                  * was added to the share definition. Connections
 385                  * that were made before force group was added
 386                  * should stay with their existing credentials.
 387                  *
 388                  * BUG: https://bugzilla.samba.org/show_bug.cgi?id=13690
 389                  */
 390
 391                 if (group_c == '+') {
 392                         int i;
 393
 394                         /*
 395                          * Only force group if the user is a member of the
 396                          * service group. Check the group memberships for this
 397                          * user (we already have this) to see if we should force
 398                          * the group.
 399                          */
 400                         for (i = 0; i < num_groups; i++) {
 401                                 if (group_list[i] == conn->force_group_gid) {
 402                                         conn->session_info->unix_token->gid =
 403                                                 conn->force_group_gid;
 404                                         gid = conn->force_group_gid;
 405                                         gid_to_sid(&conn->session_info->security_token
 406                                                    ->sids[1], gid);
 407                                         break;
 408                                 }
 409                         }
 410                 } else {
 411                         conn->session_info->unix_token->gid = conn->force_group_gid;
 412                         gid = conn->force_group_gid;
 413                         gid_to_sid(&conn->session_info->security_token->sids[1],
 414                                    gid);
 415                 }
 416         }
 417
 418         set_sec_ctx(uid,
 419                     gid,
 420                     num_groups,
 421                     group_list,
 422                     conn->session_info->security_token);
 423
 424         current_user.conn = conn;
 425         current_user.vuid = vuid;
 426         return true;
 427 }
 428
 429 /**
 430  * Impersonate user and change directory to service
 431  *
 432  * change_to_user_and_service() is used to impersonate the user associated with
 433  * the given vuid and to change the working directory of the process to the
 434  * service base directory.
 435  **/
 436 bool change_to_user_and_service(connection_struct *conn, uint64_t vuid)
 437 {
 438         int snum = SNUM(conn);
 439         struct auth_session_info *si = NULL;
 440         NTSTATUS status;
 441         bool ok;
 442
 443         if (conn == NULL) {
 444                 DBG_WARNING("Connection not open\n");
 445                 return false;
 446         }
 447
 448         status = smbXsrv_session_info_lookup(conn->sconn->client,
 449                                              vuid,
 450                                              &si);
 451         if (!NT_STATUS_IS_OK(status)) {
 452                 DBG_WARNING("Invalid vuid %llu used on share %s.\n",
 453                             (unsigned long long)vuid,
 454                             lp_const_servicename(snum));
 455                 return false;
 456         }
 457
 458         ok = change_to_user_impersonate(conn, si, vuid);
 459         if (!ok) {
 460                 return false;
 461         }
 462
 463         if (conn->tcon_done) {
 464                 ok = chdir_current_service(conn);
 465                 if (!ok) {
 466                         return false;
 467                 }
 468         }
 469
 470         print_impersonation_info(conn);
 471         return true;
 472 }
 473
 474 /**
 475  * Impersonate user and change directory to service
 476  *
 477  * change_to_user_and_service_by_fsp() is used to impersonate the user
 478  * associated with the given vuid and to change the working directory of the
 479  * process to the service base directory.
 480  **/
 481 bool change_to_user_and_service_by_fsp(struct files_struct *fsp)
 482 {
 483         return change_to_user_and_service(fsp->conn, fsp->vuid);
 484 }
 485
 486 /****************************************************************************
 487  Go back to being root without changing the security context stack,
 488  but modify the current_user entries.
 489 ****************************************************************************/
 490
 491 bool smbd_change_to_root_user(void)
 492 {
 493         set_root_sec_ctx();
 494
 495         DEBUG(5,("change_to_root_user: now uid=(%d,%d) gid=(%d,%d)\n",
 496                 (int)getuid(),(int)geteuid(),(int)getgid(),(int)getegid()));
 497
 498         current_user.conn = NULL;
 499         current_user.vuid = UID_FIELD_INVALID;
 500
 501         return(True);
 502 }
 503
 504 /****************************************************************************
 505  Become the user of an authenticated connected named pipe.
 506  When this is called we are currently running as the connection
 507  user. Doesn't modify current_user.
 508 ****************************************************************************/
 509
 510 bool smbd_become_authenticated_pipe_user(struct auth_session_info *session_info)
 511 {
 512         if (!push_sec_ctx())
 513                 return False;
 514
 515         set_current_user_info(session_info->unix_info->sanitized_username,
 516                               session_info->unix_info->unix_name,
 517                               session_info->info->domain_name);
 518
 519         set_sec_ctx(session_info->unix_token->uid, session_info->unix_token->gid,
 520                     session_info->unix_token->ngroups, session_info->unix_token->groups,
 521                     session_info->security_token);
 522
 523         DEBUG(5, ("Impersonated user: uid=(%d,%d), gid=(%d,%d)\n",
 524                  (int)getuid(),
 525                  (int)geteuid(),
 526                  (int)getgid(),
 527                  (int)getegid()));
 528
 529         return True;
 530 }
 531
 532 /****************************************************************************
 533  Unbecome the user of an authenticated connected named pipe.
 534  When this is called we are running as the authenticated pipe
 535  user and need to go back to being the connection user. Doesn't modify
 536  current_user.
 537 ****************************************************************************/
 538
 539 bool smbd_unbecome_authenticated_pipe_user(void)
 540 {
 541         return pop_sec_ctx();
 542 }
 543
 544 /****************************************************************************
 545  Utility functions used by become_xxx/unbecome_xxx.
 546 ****************************************************************************/
 547
 548 static void push_conn_ctx(void)
 549 {
 550         struct conn_ctx *ctx_p;
 551         extern userdom_struct current_user_info;
 552
 553         /* Check we don't overflow our stack */
 554
 555         if (conn_ctx_stack_ndx == MAX_SEC_CTX_DEPTH) {
 556                 DEBUG(0, ("Connection context stack overflow!\n"));
 557                 smb_panic("Connection context stack overflow!\n");
 558         }
 559
 560         /* Store previous user context */
 561         ctx_p = &conn_ctx_stack[conn_ctx_stack_ndx];
 562
 563         ctx_p->conn = current_user.conn;
 564         ctx_p->vuid = current_user.vuid;
 565         ctx_p->user_info = current_user_info;
 566
 567         DEBUG(4, ("push_conn_ctx(%llu) : conn_ctx_stack_ndx = %d\n",
 568                 (unsigned long long)ctx_p->vuid, conn_ctx_stack_ndx));
 569
 570         conn_ctx_stack_ndx++;
 571 }
 572
 573 static void pop_conn_ctx(void)
 574 {
 575         struct conn_ctx *ctx_p;
 576
 577         /* Check for stack underflow. */
 578
 579         if (conn_ctx_stack_ndx == 0) {
 580                 DEBUG(0, ("Connection context stack underflow!\n"));
 581                 smb_panic("Connection context stack underflow!\n");
 582         }
 583
 584         conn_ctx_stack_ndx--;
 585         ctx_p = &conn_ctx_stack[conn_ctx_stack_ndx];
 586
 587         set_current_user_info(ctx_p->user_info.smb_name,
 588                               ctx_p->user_info.unix_name,
 589                               ctx_p->user_info.domain);
 590
 591         current_user.conn = ctx_p->conn;
 592         current_user.vuid = ctx_p->vuid;
 593
 594         *ctx_p = (struct conn_ctx) {
 595                 .vuid = UID_FIELD_INVALID,
 596         };
 597 }
 598
 599 /****************************************************************************
 600  Temporarily become a root user.  Must match with unbecome_root(). Saves and
 601  restores the connection context.
 602 ****************************************************************************/
 603
 604 void smbd_become_root(void)
 605 {
 606          /*
 607           * no good way to handle push_sec_ctx() failing without changing
 608           * the prototype of become_root()
 609           */
 610         if (!push_sec_ctx()) {
 611                 smb_panic("become_root: push_sec_ctx failed");
 612         }
 613         push_conn_ctx();
 614         set_root_sec_ctx();
 615 }
 616
 617 /* Unbecome the root user */
 618
 619 void smbd_unbecome_root(void)
 620 {
 621         pop_sec_ctx();
 622         pop_conn_ctx();
 623 }
 624
 625 /****************************************************************************
 626  Push the current security context then force a change via change_to_user().
 627  Saves and restores the connection context.
 628 ****************************************************************************/
 629
 630 bool become_user_without_service(connection_struct *conn, uint64_t vuid)
 631 {
 632         struct auth_session_info *session_info = NULL;
 633         int snum = SNUM(conn);
 634         NTSTATUS status;
 635         bool ok;
 636
 637         if (conn == NULL) {
 638                 DBG_WARNING("Connection not open\n");
 639                 return false;
 640         }
 641
 642         status = smbXsrv_session_info_lookup(conn->sconn->client,
 643                                              vuid,
 644                                              &session_info);
 645         if (!NT_STATUS_IS_OK(status)) {
 646                 /* Invalid vuid sent */
 647                 DBG_WARNING("Invalid vuid %llu used on share %s.\n",
 648                             (unsigned long long)vuid,
 649                             lp_const_servicename(snum));
 650                 return false;
 651         }
 652
 653         ok = push_sec_ctx();
 654         if (!ok) {
 655                 return false;
 656         }
 657
 658         push_conn_ctx();
 659
 660         ok = change_to_user_impersonate(conn, session_info, vuid);
 661         if (!ok) {
 662                 pop_sec_ctx();
 663                 pop_conn_ctx();
 664                 return false;
 665         }
 666
 667         return true;
 668 }
 669
 670 bool become_user_without_service_by_fsp(struct files_struct *fsp)
 671 {
 672         return become_user_without_service(fsp->conn, fsp->vuid);
 673 }
 674
 675 bool become_user_without_service_by_session(connection_struct *conn,
 676                             const struct auth_session_info *session_info)
 677 {
 678         bool ok;
 679
 680         SMB_ASSERT(conn != NULL);
 681         SMB_ASSERT(session_info != NULL);
 682
 683         ok = push_sec_ctx();
 684         if (!ok) {
 685                 return false;
 686         }
 687
 688         push_conn_ctx();
 689
 690         ok = change_to_user_impersonate(conn, session_info, UID_FIELD_INVALID);
 691         if (!ok) {
 692                 pop_sec_ctx();
 693                 pop_conn_ctx();
 694                 return false;
 695         }
 696
 697         return true;
 698 }
 699
 700 bool unbecome_user_without_service(void)
 701 {
 702         pop_sec_ctx();
 703         pop_conn_ctx();
 704         return True;
 705 }
 706
 707 /****************************************************************************
 708  Return the current user we are running effectively as on this connection.
 709  I'd like to make this return conn->session_info->unix_token->uid, but become_root()
 710  doesn't alter this value.
 711 ****************************************************************************/
 712
 713 uid_t get_current_uid(connection_struct *conn)
 714 {
 715         return current_user.ut.uid;
 716 }
 717
 718 /****************************************************************************
 719  Return the current group we are running effectively as on this connection.
 720  I'd like to make this return conn->session_info->unix_token->gid, but become_root()
 721  doesn't alter this value.
 722 ****************************************************************************/
 723
 724 gid_t get_current_gid(connection_struct *conn)
 725 {
 726         return current_user.ut.gid;
 727 }
 728
 729 /****************************************************************************
 730  Return the UNIX token we are running effectively as on this connection.
 731  I'd like to make this return &conn->session_info->unix_token-> but become_root()
 732  doesn't alter this value.
 733 ****************************************************************************/
 734
 735 const struct security_unix_token *get_current_utok(connection_struct *conn)
 736 {
 737         return &current_user.ut;
 738 }
 739
 740 /****************************************************************************
 741  Return the Windows token we are running effectively as on this connection.
 742  If this is currently a NULL token as we're inside become_root() - a temporary
 743  UNIX security override, then we search up the stack for the previous active
 744  token.
 745 ****************************************************************************/
 746
 747 const struct security_token *get_current_nttok(connection_struct *conn)
 748 {
 749         if (current_user.nt_user_token) {
 750                 return current_user.nt_user_token;
 751         }
 752         return sec_ctx_active_token();
 753 }