source3/smbd/service.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    service (connection) opening and closing
   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/filesys.h"
  22 #include "system/passwd.h" /* uid_wrapper */
  23 #include "../lib/tsocket/tsocket.h"
  24 #include "smbd/smbd.h"
  25 #include "smbd/globals.h"
  26 #include "../librpc/gen_ndr/netlogon.h"
  27 #include "../libcli/security/security.h"
  28 #include "printing/pcap.h"
  29 #include "passdb/lookup_sid.h"
  30 #include "auth.h"
  31 #include "lib/param/loadparm.h"
  32 #include "messages.h"
  33 #include "lib/afs/afs_funcs.h"
  34
  35 static bool canonicalize_connect_path(connection_struct *conn)
  36 {
  37         bool ret;
  38         char *resolved_name = SMB_VFS_REALPATH(conn,conn->connectpath);
  39         if (!resolved_name) {
  40                 return false;
  41         }
  42         ret = set_conn_connectpath(conn,resolved_name);
  43         SAFE_FREE(resolved_name);
  44         return ret;
  45 }
  46
  47 /****************************************************************************
  48  Ensure when setting connectpath it is a canonicalized (no ./ // or ../)
  49  absolute path stating in / and not ending in /.
  50  Observent people will notice a similarity between this and check_path_syntax :-).
  51 ****************************************************************************/
  52
  53 bool set_conn_connectpath(connection_struct *conn, const char *connectpath)
  54 {
  55         char *destname;
  56         char *d;
  57         const char *s = connectpath;
  58         bool start_of_name_component = true;
  59
  60         if (connectpath == NULL || connectpath[0] == '\0') {
  61                 return false;
  62         }
  63
  64         /* Allocate for strlen + '\0' + possible leading '/' */
  65         destname = (char *)talloc_size(conn, strlen(connectpath) + 2);
  66         if (!destname) {
  67                 return false;
  68         }
  69         d = destname;
  70
  71         *d++ = '/'; /* Always start with root. */
  72
  73         while (*s) {
  74                 if (*s == '/') {
  75                         /* Eat multiple '/' */
  76                         while (*s == '/') {
  77                                 s++;
  78                         }
  79                         if ((d > destname + 1) && (*s != '\0')) {
  80                                 *d++ = '/';
  81                         }
  82                         start_of_name_component = True;
  83                         continue;
  84                 }
  85
  86                 if (start_of_name_component) {
  87                         if ((s[0] == '.') && (s[1] == '.') && (s[2] == '/' || s[2] == '\0')) {
  88                                 /* Uh oh - "/../" or "/..\0" ! */
  89
  90                                 /* Go past the ../ or .. */
  91                                 if (s[2] == '/') {
  92                                         s += 3;
  93                                 } else {
  94                                         s += 2; /* Go past the .. */
  95                                 }
  96
  97                                 /* If  we just added a '/' - delete it */
  98                                 if ((d > destname) && (*(d-1) == '/')) {
  99                                         *(d-1) = '\0';
 100                                         d--;
 101                                 }
 102
 103                                 /* Are we at the start ? Can't go back further if so. */
 104                                 if (d <= destname) {
 105                                         *d++ = '/'; /* Can't delete root */
 106                                         continue;
 107                                 }
 108                                 /* Go back one level... */
 109                                 /* Decrement d first as d points to the *next* char to write into. */
 110                                 for (d--; d > destname; d--) {
 111                                         if (*d == '/') {
 112                                                 break;
 113                                         }
 114                                 }
 115                                 /* We're still at the start of a name component, just the previous one. */
 116                                 continue;
 117                         } else if ((s[0] == '.') && ((s[1] == '\0') || s[1] == '/')) {
 118                                 /* Component of pathname can't be "." only - skip the '.' . */
 119                                 if (s[1] == '/') {
 120                                         s += 2;
 121                                 } else {
 122                                         s++;
 123                                 }
 124                                 continue;
 125                         }
 126                 }
 127
 128                 if (!(*s & 0x80)) {
 129                         *d++ = *s++;
 130                 } else {
 131                         size_t siz;
 132                         /* Get the size of the next MB character. */
 133                         next_codepoint(s,&siz);
 134                         switch(siz) {
 135                                 case 5:
 136                                         *d++ = *s++;
 137                                         /*fall through*/
 138                                 case 4:
 139                                         *d++ = *s++;
 140                                         /*fall through*/
 141                                 case 3:
 142                                         *d++ = *s++;
 143                                         /*fall through*/
 144                                 case 2:
 145                                         *d++ = *s++;
 146                                         /*fall through*/
 147                                 case 1:
 148                                         *d++ = *s++;
 149                                         break;
 150                                 default:
 151                                         break;
 152                         }
 153                 }
 154                 start_of_name_component = false;
 155         }
 156         *d = '\0';
 157
 158         /* And must not end in '/' */
 159         if (d > destname + 1 && (*(d-1) == '/')) {
 160                 *(d-1) = '\0';
 161         }
 162
 163         DEBUG(10,("set_conn_connectpath: service %s, connectpath = %s\n",
 164                 lp_servicename(talloc_tos(), SNUM(conn)), destname ));
 165
 166         talloc_free(conn->connectpath);
 167         conn->connectpath = destname;
 168         /* Ensure conn->cwd is initialized - start as conn->connectpath. */
 169         TALLOC_FREE(conn->cwd);
 170         conn->cwd = talloc_strdup(conn, conn->connectpath);
 171         if (!conn->cwd) {
 172                 return false;
 173         }
 174         return true;
 175 }
 176
 177 /****************************************************************************
 178  Load parameters specific to a connection/service.
 179 ****************************************************************************/
 180
 181 bool set_current_service(connection_struct *conn, uint16_t flags, bool do_chdir)
 182 {
 183         int snum;
 184
 185         if (!conn)  {
 186                 last_conn = NULL;
 187                 return(False);
 188         }
 189
 190         conn->lastused_count++;
 191
 192         snum = SNUM(conn);
 193
 194         if (do_chdir &&
 195             vfs_ChDir(conn,conn->connectpath) != 0 &&
 196             vfs_ChDir(conn,conn->origpath) != 0) {
 197                 DEBUG(((errno!=EACCES)?0:3),("chdir (%s) failed, reason: %s\n",
 198                          conn->connectpath, strerror(errno)));
 199                 return(False);
 200         }
 201
 202         if ((conn == last_conn) && (last_flags == flags)) {
 203                 return(True);
 204         }
 205
 206         last_conn = conn;
 207         last_flags = flags;
 208
 209         /* Obey the client case sensitivity requests - only for clients that support it. */
 210         switch (lp_case_sensitive(snum)) {
 211                 case Auto:
 212                         {
 213                                 /* We need this uglyness due to DOS/Win9x clients that lie about case insensitivity. */
 214                                 enum remote_arch_types ra_type = get_remote_arch();
 215                                 if ((ra_type != RA_SAMBA) && (ra_type != RA_CIFSFS)) {
 216                                         /* Client can't support per-packet case sensitive pathnames. */
 217                                         conn->case_sensitive = False;
 218                                 } else {
 219                                         conn->case_sensitive = !(flags & FLAG_CASELESS_PATHNAMES);
 220                                 }
 221                         }
 222                         break;
 223                 case True:
 224                         conn->case_sensitive = True;
 225                         break;
 226                 default:
 227                         conn->case_sensitive = False;
 228                         break;
 229         }
 230         return(True);
 231 }
 232
 233 /****************************************************************************
 234  do some basic sainity checks on the share.
 235  This function modifies dev, ecode.
 236 ****************************************************************************/
 237
 238 static NTSTATUS share_sanity_checks(const struct tsocket_address *remote_address,
 239                                     const char *rhost,
 240                                     int snum,
 241                                     fstring dev)
 242 {
 243         char *raddr;
 244
 245         raddr = tsocket_address_inet_addr_string(remote_address,
 246                                                  talloc_tos());
 247         if (raddr == NULL) {
 248                 return NT_STATUS_NO_MEMORY;
 249         }
 250
 251         if (!lp_snum_ok(snum) ||
 252             !allow_access(lp_hosts_deny(snum), lp_hosts_allow(snum),
 253                           rhost, raddr)) {
 254                 return NT_STATUS_ACCESS_DENIED;
 255         }
 256
 257         if (dev[0] == '?' || !dev[0]) {
 258                 if (lp_printable(snum)) {
 259                         fstrcpy(dev,"LPT1:");
 260                 } else if (strequal(lp_fstype(snum), "IPC")) {
 261                         fstrcpy(dev, "IPC");
 262                 } else {
 263                         fstrcpy(dev,"A:");
 264                 }
 265         }
 266
 267         if (!strupper_m(dev)) {
 268                 DEBUG(2,("strupper_m %s failed\n", dev));
 269                 return NT_STATUS_INVALID_PARAMETER;
 270         }
 271
 272         if (lp_printable(snum)) {
 273                 if (!strequal(dev, "LPT1:")) {
 274                         return NT_STATUS_BAD_DEVICE_TYPE;
 275                 }
 276         } else if (strequal(lp_fstype(snum), "IPC")) {
 277                 if (!strequal(dev, "IPC")) {
 278                         return NT_STATUS_BAD_DEVICE_TYPE;
 279                 }
 280         } else if (!strequal(dev, "A:")) {
 281                 return NT_STATUS_BAD_DEVICE_TYPE;
 282         }
 283
 284         /* Behave as a printer if we are supposed to */
 285         if (lp_printable(snum) && (strcmp(dev, "A:") == 0)) {
 286                 fstrcpy(dev, "LPT1:");
 287         }
 288
 289         return NT_STATUS_OK;
 290 }
 291
 292 /*
 293  * Go through lookup_name etc to find the force'd group.
 294  *
 295  * Create a new token from src_token, replacing the primary group sid with the
 296  * one found.
 297  */
 298
 299 static NTSTATUS find_forced_group(bool force_user,
 300                                   int snum, const char *username,
 301                                   struct dom_sid *pgroup_sid,
 302                                   gid_t *pgid)
 303 {
 304         NTSTATUS result = NT_STATUS_NO_SUCH_GROUP;
 305         TALLOC_CTX *frame = talloc_stackframe();
 306         struct dom_sid group_sid;
 307         enum lsa_SidType type;
 308         char *groupname;
 309         bool user_must_be_member = False;
 310         gid_t gid;
 311
 312         groupname = lp_force_group(talloc_tos(), snum);
 313         if (groupname == NULL) {
 314                 DEBUG(1, ("talloc_strdup failed\n"));
 315                 result = NT_STATUS_NO_MEMORY;
 316                 goto done;
 317         }
 318
 319         if (groupname[0] == '+') {
 320                 user_must_be_member = True;
 321                 groupname += 1;
 322         }
 323
 324         groupname = talloc_string_sub(talloc_tos(), groupname,
 325                                       "%S", lp_servicename(talloc_tos(), snum));
 326         if (groupname == NULL) {
 327                 DEBUG(1, ("talloc_string_sub failed\n"));
 328                 result = NT_STATUS_NO_MEMORY;
 329                 goto done;
 330         }
 331
 332         if (!lookup_name_smbconf(talloc_tos(), groupname,
 333                          LOOKUP_NAME_ALL|LOOKUP_NAME_GROUP,
 334                          NULL, NULL, &group_sid, &type)) {
 335                 DEBUG(10, ("lookup_name_smbconf(%s) failed\n",
 336                            groupname));
 337                 goto done;
 338         }
 339
 340         if ((type != SID_NAME_DOM_GRP) && (type != SID_NAME_ALIAS) &&
 341             (type != SID_NAME_WKN_GRP)) {
 342                 DEBUG(10, ("%s is a %s, not a group\n", groupname,
 343                            sid_type_lookup(type)));
 344                 goto done;
 345         }
 346
 347         if (!sid_to_gid(&group_sid, &gid)) {
 348                 DEBUG(10, ("sid_to_gid(%s) for %s failed\n",
 349                            sid_string_dbg(&group_sid), groupname));
 350                 goto done;
 351         }
 352
 353         /*
 354          * If the user has been forced and the forced group starts with a '+',
 355          * then we only set the group to be the forced group if the forced
 356          * user is a member of that group.  Otherwise, the meaning of the '+'
 357          * would be ignored.
 358          */
 359
 360         if (force_user && user_must_be_member) {
 361                 if (user_in_group_sid(username, &group_sid)) {
 362                         sid_copy(pgroup_sid, &group_sid);
 363                         *pgid = gid;
 364                         DEBUG(3,("Forced group %s for member %s\n",
 365                                  groupname, username));
 366                 } else {
 367                         DEBUG(0,("find_forced_group: forced user %s is not a member "
 368                                 "of forced group %s. Disallowing access.\n",
 369                                 username, groupname ));
 370                         result = NT_STATUS_MEMBER_NOT_IN_GROUP;
 371                         goto done;
 372                 }
 373         } else {
 374                 sid_copy(pgroup_sid, &group_sid);
 375                 *pgid = gid;
 376                 DEBUG(3,("Forced group %s\n", groupname));
 377         }
 378
 379         result = NT_STATUS_OK;
 380  done:
 381         TALLOC_FREE(frame);
 382         return result;
 383 }
 384
 385 /****************************************************************************
 386   Create an auth_session_info structure for a connection_struct
 387 ****************************************************************************/
 388
 389 static NTSTATUS create_connection_session_info(struct smbd_server_connection *sconn,
 390                                               TALLOC_CTX *mem_ctx, int snum,
 391                                               struct auth_session_info *session_info,
 392                                               struct auth_session_info **presult)
 393 {
 394         struct auth_session_info *result;
 395
 396         if (lp_guest_only(snum)) {
 397                 return make_session_info_guest(mem_ctx, presult);
 398         }
 399
 400         /*
 401          * This is the normal security != share case where we have a
 402          * valid vuid from the session setup.                 */
 403
 404         if (security_session_user_level(session_info, NULL) < SECURITY_USER) {
 405                 if (!lp_guest_ok(snum)) {
 406                         DEBUG(2, ("guest user (from session setup) "
 407                                   "not permitted to access this share "
 408                                   "(%s)\n", lp_servicename(talloc_tos(), snum)));
 409                         return NT_STATUS_ACCESS_DENIED;
 410                 }
 411         } else {
 412                 if (!user_ok_token(session_info->unix_info->unix_name,
 413                                    session_info->info->domain_name,
 414                                    session_info->security_token, snum)) {
 415                         DEBUG(2, ("user '%s' (from session setup) not "
 416                                   "permitted to access this share "
 417                                   "(%s)\n",
 418                                   session_info->unix_info->unix_name,
 419                                   lp_servicename(talloc_tos(), snum)));
 420                         return NT_STATUS_ACCESS_DENIED;
 421                 }
 422         }
 423
 424         result = copy_session_info(mem_ctx, session_info);
 425         if (result == NULL) {
 426                 return NT_STATUS_NO_MEMORY;
 427         }
 428
 429         *presult = result;
 430         return NT_STATUS_OK;
 431 }
 432
 433 /****************************************************************************
 434   Set relevant user and group settings corresponding to force user/group
 435   configuration for the given snum.
 436 ****************************************************************************/
 437
 438 NTSTATUS set_conn_force_user_group(connection_struct *conn, int snum)
 439 {
 440         NTSTATUS status;
 441
 442         if (*lp_force_user(talloc_tos(), snum)) {
 443
 444                 /*
 445                  * Replace conn->session_info with a completely faked up one
 446                  * from the username we are forced into :-)
 447                  */
 448
 449                 char *fuser;
 450                 char *sanitized_username;
 451                 struct auth_session_info *forced_serverinfo;
 452                 bool guest;
 453
 454                 fuser = talloc_string_sub(conn, lp_force_user(talloc_tos(), snum), "%S",
 455                                           lp_const_servicename(snum));
 456                 if (fuser == NULL) {
 457                         return NT_STATUS_NO_MEMORY;
 458                 }
 459
 460                 guest = security_session_user_level(conn->session_info, NULL) < SECURITY_USER;
 461
 462                 status = make_session_info_from_username(
 463                         conn, fuser,
 464                         guest,
 465                         &forced_serverinfo);
 466                 if (!NT_STATUS_IS_OK(status)) {
 467                         return status;
 468                 }
 469
 470                 /* We don't want to replace the original sanitized_username
 471                    as it is the original user given in the connect attempt.
 472                    This is used in '%U' substitutions. */
 473                 sanitized_username = discard_const_p(char,
 474                         forced_serverinfo->unix_info->sanitized_username);
 475                 TALLOC_FREE(sanitized_username);
 476                 forced_serverinfo->unix_info->sanitized_username =
 477                         talloc_move(forced_serverinfo->unix_info,
 478                                 &conn->session_info->unix_info->sanitized_username);
 479
 480                 TALLOC_FREE(conn->session_info);
 481                 conn->session_info = forced_serverinfo;
 482
 483                 conn->force_user = true;
 484                 DEBUG(3,("Forced user %s\n", fuser));
 485         }
 486
 487         /*
 488          * If force group is true, then override
 489          * any groupid stored for the connecting user.
 490          */
 491
 492         if (*lp_force_group(talloc_tos(), snum)) {
 493
 494                 status = find_forced_group(
 495                         conn->force_user, snum, conn->session_info->unix_info->unix_name,
 496                         &conn->session_info->security_token->sids[1],
 497                         &conn->session_info->unix_token->gid);
 498
 499                 if (!NT_STATUS_IS_OK(status)) {
 500                         return status;
 501                 }
 502
 503                 /*
 504                  * We need to cache this gid, to use within
 505                  * change_to_user() separately from the conn->session_info
 506                  * struct. We only use conn->session_info directly if
 507                  * "force_user" was set.
 508                  */
 509                 conn->force_group_gid = conn->session_info->unix_token->gid;
 510         }
 511
 512         return NT_STATUS_OK;
 513 }
 514
 515 /****************************************************************************
 516   Make a connection, given the snum to connect to, and the vuser of the
 517   connecting user if appropriate.
 518 ****************************************************************************/
 519
 520 static NTSTATUS make_connection_snum(struct smbXsrv_connection *xconn,
 521                                         connection_struct *conn,
 522                                         int snum, struct user_struct *vuser,
 523                                         const char *pdev)
 524 {
 525         struct smbd_server_connection *sconn = xconn->client->sconn;
 526         struct smb_filename *smb_fname_cpath = NULL;
 527         fstring dev;
 528         int ret;
 529         bool on_err_call_dis_hook = false;
 530         uid_t effuid;
 531         gid_t effgid;
 532         NTSTATUS status;
 533
 534         fstrcpy(dev, pdev);
 535
 536         status = share_sanity_checks(sconn->remote_address,
 537                                        sconn->remote_hostname,
 538                                        snum,
 539                                        dev);
 540         if (NT_STATUS_IS_ERR(status)) {
 541                 goto err_root_exit;
 542         }
 543
 544         conn->params->service = snum;
 545
 546         status = create_connection_session_info(sconn,
 547                 conn, snum, vuser->session_info,
 548                 &conn->session_info);
 549
 550         if (!NT_STATUS_IS_OK(status)) {
 551                 DEBUG(1, ("create_connection_session_info failed: %s\n",
 552                           nt_errstr(status)));
 553                 goto err_root_exit;
 554         }
 555
 556         if (lp_guest_only(snum)) {
 557                 conn->force_user = true;
 558         }
 559
 560         conn->num_files_open = 0;
 561         conn->lastused = conn->lastused_count = time(NULL);
 562         conn->printer = (strncmp(dev,"LPT",3) == 0);
 563         conn->ipc = ( (strncmp(dev,"IPC",3) == 0) ||
 564                       ( lp_enable_asu_support() && strequal(dev,"ADMIN$")) );
 565
 566         /* Case options for the share. */
 567         if (lp_case_sensitive(snum) == Auto) {
 568                 /* We will be setting this per packet. Set to be case
 569                  * insensitive for now. */
 570                 conn->case_sensitive = False;
 571         } else {
 572                 conn->case_sensitive = (bool)lp_case_sensitive(snum);
 573         }
 574
 575         conn->case_preserve = lp_preserve_case(snum);
 576         conn->short_case_preserve = lp_short_preserve_case(snum);
 577
 578         conn->encrypt_level = lp_smb_encrypt(snum);
 579
 580         conn->veto_list = NULL;
 581         conn->hide_list = NULL;
 582         conn->veto_oplock_list = NULL;
 583         conn->aio_write_behind_list = NULL;
 584
 585         conn->read_only = lp_read_only(SNUM(conn));
 586
 587         status = set_conn_force_user_group(conn, snum);
 588         if (!NT_STATUS_IS_OK(status)) {
 589                 goto err_root_exit;
 590         }
 591
 592         conn->vuid = vuser->vuid;
 593
 594         {
 595                 char *s = talloc_sub_advanced(talloc_tos(),
 596                                         lp_servicename(talloc_tos(), SNUM(conn)),
 597                                         conn->session_info->unix_info->unix_name,
 598                                         conn->connectpath,
 599                                         conn->session_info->unix_token->gid,
 600                                         conn->session_info->unix_info->sanitized_username,
 601                                         conn->session_info->info->domain_name,
 602                                         lp_path(talloc_tos(), snum));
 603                 if (!s) {
 604                         status = NT_STATUS_NO_MEMORY;
 605                         goto err_root_exit;
 606                 }
 607
 608                 if (!set_conn_connectpath(conn,s)) {
 609                         TALLOC_FREE(s);
 610                         status = NT_STATUS_NO_MEMORY;
 611                         goto err_root_exit;
 612                 }
 613                 DEBUG(3,("Connect path is '%s' for service [%s]\n",s,
 614                          lp_servicename(talloc_tos(), snum)));
 615                 TALLOC_FREE(s);
 616         }
 617
 618         /*
 619          * Set up the share security descriptor.
 620          * NOTE - we use the *INCOMING USER* session_info
 621          * here, as does (indirectly) change_to_user(),
 622          * which can be called on any incoming packet.
 623          * This way we set up the share access based
 624          * on the authenticated user, not the forced
 625          * user. See bug:
 626          *
 627          * https://bugzilla.samba.org/show_bug.cgi?id=9878
 628          */
 629
 630         status = check_user_share_access(conn,
 631                                         vuser->session_info,
 632                                         &conn->share_access,
 633                                         &conn->read_only);
 634         if (!NT_STATUS_IS_OK(status)) {
 635                 goto err_root_exit;
 636         }
 637
 638         /* Initialise VFS function pointers */
 639
 640         if (!smbd_vfs_init(conn)) {
 641                 DEBUG(0, ("vfs_init failed for service %s\n",
 642                           lp_servicename(talloc_tos(), snum)));
 643                 status = NT_STATUS_BAD_NETWORK_NAME;
 644                 goto err_root_exit;
 645         }
 646
 647 /* ROOT Activities: */
 648         /* explicitly check widelinks here so that we can correctly warn
 649          * in the logs. */
 650         widelinks_warning(snum);
 651
 652         /*
 653          * Enforce the max connections parameter.
 654          */
 655
 656         if ((lp_max_connections(snum) > 0)
 657             && (count_current_connections(lp_servicename(talloc_tos(), SNUM(conn)), True) >=
 658                 lp_max_connections(snum))) {
 659
 660                 DEBUG(1, ("Max connections (%d) exceeded for %s\n",
 661                           lp_max_connections(snum),
 662                           lp_servicename(talloc_tos(), snum)));
 663                 status = NT_STATUS_INSUFFICIENT_RESOURCES;
 664                 goto err_root_exit;
 665         }
 666
 667         /* Invoke VFS make connection hook - this must be the first
 668            filesystem operation that we do. */
 669
 670         if (SMB_VFS_CONNECT(conn, lp_servicename(talloc_tos(), snum),
 671                             conn->session_info->unix_info->unix_name) < 0) {
 672                 DEBUG(0,("make_connection: VFS make connection failed!\n"));
 673                 status = NT_STATUS_UNSUCCESSFUL;
 674                 goto err_root_exit;
 675         }
 676
 677         /* Any error exit after here needs to call the disconnect hook. */
 678         on_err_call_dis_hook = true;
 679
 680         if ((!conn->printer) && (!conn->ipc) &&
 681             lp_change_notify()) {
 682                 if (sconn->notify_ctx == NULL) {
 683                         sconn->notify_ctx = notify_init(
 684                                 sconn, sconn->msg_ctx, sconn->ev_ctx);
 685                         status = messaging_register(
 686                                 sconn->msg_ctx, sconn,
 687                                 MSG_SMB_NOTIFY_CANCEL_DELETED,
 688                                 smbd_notify_cancel_deleted);
 689                 }
 690                 if (sconn->sys_notify_ctx == NULL) {
 691                         sconn->sys_notify_ctx = sys_notify_context_create(
 692                                 sconn, sconn->ev_ctx);
 693                 }
 694         }
 695
 696         if (lp_kernel_oplocks(snum)) {
 697                 init_kernel_oplocks(conn->sconn);
 698         }
 699
 700         /*
 701          * Fix compatibility issue pointed out by Volker.
 702          * We pass the conn->connectpath to the preexec
 703          * scripts as a parameter, so attempt to canonicalize
 704          * it here before calling the preexec scripts.
 705          * We ignore errors here, as it is possible that
 706          * the conn->connectpath doesn't exist yet and
 707          * the preexec scripts will create them.
 708          */
 709
 710         (void)canonicalize_connect_path(conn);
 711
 712         /* Preexecs are done here as they might make the dir we are to ChDir
 713          * to below */
 714         /* execute any "root preexec = " line */
 715         if (*lp_root_preexec(talloc_tos(), snum)) {
 716                 char *cmd = talloc_sub_advanced(talloc_tos(),
 717                                         lp_servicename(talloc_tos(), SNUM(conn)),
 718                                         conn->session_info->unix_info->unix_name,
 719                                         conn->connectpath,
 720                                         conn->session_info->unix_token->gid,
 721                                         conn->session_info->unix_info->sanitized_username,
 722                                         conn->session_info->info->domain_name,
 723                                         lp_root_preexec(talloc_tos(), snum));
 724                 DEBUG(5,("cmd=%s\n",cmd));
 725                 ret = smbrun(cmd,NULL);
 726                 TALLOC_FREE(cmd);
 727                 if (ret != 0 && lp_root_preexec_close(snum)) {
 728                         DEBUG(1,("root preexec gave %d - failing "
 729                                  "connection\n", ret));
 730                         status = NT_STATUS_ACCESS_DENIED;
 731                         goto err_root_exit;
 732                 }
 733         }
 734
 735 /* USER Activites: */
 736         if (!change_to_user(conn, conn->vuid)) {
 737                 /* No point continuing if they fail the basic checks */
 738                 DEBUG(0,("Can't become connected user!\n"));
 739                 status = NT_STATUS_LOGON_FAILURE;
 740                 goto err_root_exit;
 741         }
 742
 743         effuid = geteuid();
 744         effgid = getegid();
 745
 746         /* Remember that a different vuid can connect later without these
 747          * checks... */
 748
 749         /* Preexecs are done here as they might make the dir we are to ChDir
 750          * to below */
 751
 752         /* execute any "preexec = " line */
 753         if (*lp_preexec(talloc_tos(), snum)) {
 754                 char *cmd = talloc_sub_advanced(talloc_tos(),
 755                                         lp_servicename(talloc_tos(), SNUM(conn)),
 756                                         conn->session_info->unix_info->unix_name,
 757                                         conn->connectpath,
 758                                         conn->session_info->unix_token->gid,
 759                                         conn->session_info->unix_info->sanitized_username,
 760                                         conn->session_info->info->domain_name,
 761                                         lp_preexec(talloc_tos(), snum));
 762                 ret = smbrun(cmd,NULL);
 763                 TALLOC_FREE(cmd);
 764                 if (ret != 0 && lp_preexec_close(snum)) {
 765                         DEBUG(1,("preexec gave %d - failing connection\n",
 766                                  ret));
 767                         status = NT_STATUS_ACCESS_DENIED;
 768                         goto err_root_exit;
 769                 }
 770         }
 771
 772 #ifdef WITH_FAKE_KASERVER
 773         if (lp_afs_share(snum)) {
 774                 afs_login(conn);
 775         }
 776 #endif
 777
 778         /*
 779          * we've finished with the user stuff - go back to root
 780          * so the SMB_VFS_STAT call will only fail on path errors,
 781          * not permission problems.
 782          */
 783         change_to_root_user();
 784 /* ROOT Activites: */
 785
 786         /*
 787          * If widelinks are disallowed we need to canonicalise the connect
 788          * path here to ensure we don't have any symlinks in the
 789          * connectpath. We will be checking all paths on this connection are
 790          * below this directory. We must do this after the VFS init as we
 791          * depend on the realpath() pointer in the vfs table. JRA.
 792          */
 793         if (!lp_widelinks(snum)) {
 794                 if (!canonicalize_connect_path(conn)) {
 795                         DEBUG(0, ("canonicalize_connect_path failed "
 796                         "for service %s, path %s\n",
 797                                 lp_servicename(talloc_tos(), snum),
 798                                 conn->connectpath));
 799                         status = NT_STATUS_BAD_NETWORK_NAME;
 800                         goto err_root_exit;
 801                 }
 802         }
 803
 804         /* Add veto/hide lists */
 805         if (!IS_IPC(conn) && !IS_PRINT(conn)) {
 806                 set_namearray( &conn->veto_list,
 807                                lp_veto_files(talloc_tos(), snum));
 808                 set_namearray( &conn->hide_list,
 809                                lp_hide_files(talloc_tos(), snum));
 810                 set_namearray( &conn->veto_oplock_list,
 811                                lp_veto_oplock_files(talloc_tos(), snum));
 812                 set_namearray( &conn->aio_write_behind_list,
 813                                 lp_aio_write_behind(talloc_tos(), snum));
 814         }
 815         smb_fname_cpath = synthetic_smb_fname(talloc_tos(), conn->connectpath,
 816                                               NULL, NULL);
 817         if (smb_fname_cpath == NULL) {
 818                 status = NT_STATUS_NO_MEMORY;
 819                 goto err_root_exit;
 820         }
 821
 822         /* win2000 does not check the permissions on the directory
 823            during the tree connect, instead relying on permission
 824            check during individual operations. To match this behaviour
 825            I have disabled this chdir check (tridge) */
 826         /* the alternative is just to check the directory exists */
 827
 828         if ((ret = SMB_VFS_STAT(conn, smb_fname_cpath)) != 0 ||
 829             !S_ISDIR(smb_fname_cpath->st.st_ex_mode)) {
 830                 if (ret == 0 && !S_ISDIR(smb_fname_cpath->st.st_ex_mode)) {
 831                         DEBUG(0,("'%s' is not a directory, when connecting to "
 832                                  "[%s]\n", conn->connectpath,
 833                                  lp_servicename(talloc_tos(), snum)));
 834                 } else {
 835                         DEBUG(0,("'%s' does not exist or permission denied "
 836                                  "when connecting to [%s] Error was %s\n",
 837                                  conn->connectpath,
 838                                  lp_servicename(talloc_tos(), snum),
 839                                  strerror(errno) ));
 840                 }
 841                 status = NT_STATUS_BAD_NETWORK_NAME;
 842                 goto err_root_exit;
 843         }
 844         conn->base_share_dev = smb_fname_cpath->st.st_ex_dev;
 845
 846         talloc_free(conn->origpath);
 847         conn->origpath = talloc_strdup(conn, conn->connectpath);
 848
 849         /* Figure out the characteristics of the underlying filesystem. This
 850          * assumes that all the filesystem mounted withing a share path have
 851          * the same characteristics, which is likely but not guaranteed.
 852          */
 853
 854         conn->fs_capabilities = SMB_VFS_FS_CAPABILITIES(conn, &conn->ts_res);
 855
 856         /*
 857          * Print out the 'connected as' stuff here as we need
 858          * to know the effective uid and gid we will be using
 859          * (at least initially).
 860          */
 861
 862         if( DEBUGLVL( IS_IPC(conn) ? 3 : 2 ) ) {
 863                 dbgtext( "%s (%s) ", get_remote_machine_name(),
 864                          tsocket_address_string(conn->sconn->remote_address,
 865                                                 talloc_tos()) );
 866                 dbgtext( "%s", srv_is_signing_active(xconn) ? "signed " : "");
 867                 dbgtext( "connect to service %s ",
 868                          lp_servicename(talloc_tos(), snum) );
 869                 dbgtext( "initially as user %s ",
 870                          conn->session_info->unix_info->unix_name );
 871                 dbgtext( "(uid=%d, gid=%d) ", (int)effuid, (int)effgid );
 872                 dbgtext( "(pid %d)\n", (int)getpid() );
 873         }
 874
 875         return status;
 876
 877   err_root_exit:
 878
 879         TALLOC_FREE(smb_fname_cpath);
 880         /* We must exit this function as root. */
 881         if (geteuid() != 0) {
 882                 change_to_root_user();
 883         }
 884         if (on_err_call_dis_hook) {
 885                 /* Call VFS disconnect hook */
 886                 SMB_VFS_DISCONNECT(conn);
 887         }
 888         return status;
 889 }
 890
 891 /****************************************************************************
 892  Make a connection to a service from SMB1. Internal interface.
 893 ****************************************************************************/
 894
 895 static connection_struct *make_connection_smb1(struct smb_request *req,
 896                                         NTTIME now,
 897                                         int snum, struct user_struct *vuser,
 898                                         const char *pdev,
 899                                         NTSTATUS *pstatus)
 900 {
 901         struct smbXsrv_tcon *tcon;
 902         NTSTATUS status;
 903         struct connection_struct *conn;
 904
 905         status = smb1srv_tcon_create(req->xconn, now, &tcon);
 906         if (!NT_STATUS_IS_OK(status)) {
 907                 DEBUG(0,("make_connection_smb1: Couldn't find free tcon %s.\n",
 908                          nt_errstr(status)));
 909                 *pstatus = status;
 910                 return NULL;
 911         }
 912
 913         conn = conn_new(req->sconn);
 914         if (!conn) {
 915                 TALLOC_FREE(tcon);
 916
 917                 DEBUG(0,("make_connection_smb1: Couldn't find free connection.\n"));
 918                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 919                 return NULL;
 920         }
 921
 922         conn->cnum = tcon->global->tcon_wire_id;
 923         conn->tcon = tcon;
 924
 925         *pstatus = make_connection_snum(req->xconn,
 926                                         conn,
 927                                         snum,
 928                                         vuser,
 929                                         pdev);
 930         if (!NT_STATUS_IS_OK(*pstatus)) {
 931                 conn_free(conn);
 932                 TALLOC_FREE(tcon);
 933                 return NULL;
 934         }
 935
 936         tcon->global->share_name = lp_servicename(tcon->global, SNUM(conn));
 937         if (tcon->global->share_name == NULL) {
 938                 conn_free(conn);
 939                 TALLOC_FREE(tcon);
 940                 *pstatus = NT_STATUS_NO_MEMORY;
 941                 return NULL;
 942         }
 943         tcon->global->session_global_id =
 944                 vuser->session->global->session_global_id;
 945
 946         tcon->compat = talloc_move(tcon, &conn);
 947         tcon->status = NT_STATUS_OK;
 948
 949         *pstatus = smbXsrv_tcon_update(tcon);
 950         if (!NT_STATUS_IS_OK(*pstatus)) {
 951                 TALLOC_FREE(tcon);
 952                 return NULL;
 953         }
 954
 955         return tcon->compat;
 956 }
 957
 958 /****************************************************************************
 959  Make a connection to a service from SMB2. External SMB2 interface.
 960  We must set cnum before claiming connection.
 961 ****************************************************************************/
 962
 963 connection_struct *make_connection_smb2(struct smbd_smb2_request *req,
 964                                         struct smbXsrv_tcon *tcon,
 965                                         int snum,
 966                                         struct user_struct *vuser,
 967                                         const char *pdev,
 968                                         NTSTATUS *pstatus)
 969 {
 970         struct smbd_server_connection *sconn = req->sconn;
 971         connection_struct *conn = conn_new(sconn);
 972         if (!conn) {
 973                 DEBUG(0,("make_connection_smb2: Couldn't find free connection.\n"));
 974                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 975                 return NULL;
 976         }
 977
 978         conn->cnum = tcon->global->tcon_wire_id;
 979         conn->tcon = tcon;
 980
 981         *pstatus = make_connection_snum(req->xconn,
 982                                         conn,
 983                                         snum,
 984                                         vuser,
 985                                         pdev);
 986         if (!NT_STATUS_IS_OK(*pstatus)) {
 987                 conn_free(conn);
 988                 return NULL;
 989         }
 990         return conn;
 991 }
 992
 993 /****************************************************************************
 994  Make a connection to a service. External SMB1 interface.
 995  *
 996  * @param service
 997 ****************************************************************************/
 998
 999 connection_struct *make_connection(struct smb_request *req,
1000                                    NTTIME now,
1001                                    const char *service_in,
1002                                    const char *pdev, uint64_t vuid,
1003                                    NTSTATUS *status)
1004 {
1005         struct smbd_server_connection *sconn = req->sconn;
1006         uid_t euid;
1007         struct user_struct *vuser = NULL;
1008         char *service = NULL;
1009         fstring dev;
1010         int snum = -1;
1011
1012         fstrcpy(dev, pdev);
1013
1014         /* This must ONLY BE CALLED AS ROOT. As it exits this function as
1015          * root. */
1016         if (!non_root_mode() && (euid = geteuid()) != 0) {
1017                 DEBUG(0,("make_connection: PANIC ERROR. Called as nonroot "
1018                          "(%u)\n", (unsigned int)euid ));
1019                 smb_panic("make_connection: PANIC ERROR. Called as nonroot\n");
1020         }
1021
1022         if (conn_num_open(sconn) > 2047) {
1023                 *status = NT_STATUS_INSUFF_SERVER_RESOURCES;
1024                 return NULL;
1025         }
1026
1027         vuser = get_valid_user_struct(sconn, vuid);
1028         if (!vuser) {
1029                 DEBUG(1,("make_connection: refusing to connect with "
1030                          "no session setup\n"));
1031                 *status = NT_STATUS_ACCESS_DENIED;
1032                 return NULL;
1033         }
1034
1035         /* Logic to try and connect to the correct [homes] share, preferably
1036            without too many getpwnam() lookups.  This is particulary nasty for
1037            winbind usernames, where the share name isn't the same as unix
1038            username.
1039
1040            The snum of the homes share is stored on the vuser at session setup
1041            time.
1042         */
1043
1044         if (strequal(service_in,HOMES_NAME)) {
1045                 if (vuser->homes_snum == -1) {
1046                         DEBUG(2, ("[homes] share not available for "
1047                                   "this user because it was not found "
1048                                   "or created at session setup "
1049                                   "time\n"));
1050                         *status = NT_STATUS_BAD_NETWORK_NAME;
1051                         return NULL;
1052                 }
1053                 DEBUG(5, ("making a connection to [homes] service "
1054                           "created at session setup time\n"));
1055                 return make_connection_smb1(req, now,
1056                                             vuser->homes_snum,
1057                                             vuser,
1058                                             dev, status);
1059         } else if ((vuser->homes_snum != -1)
1060                    && strequal(service_in,
1061                                lp_servicename(talloc_tos(), vuser->homes_snum))) {
1062                 DEBUG(5, ("making a connection to 'homes' service [%s] "
1063                           "created at session setup time\n", service_in));
1064                 return make_connection_smb1(req, now,
1065                                             vuser->homes_snum,
1066                                             vuser,
1067                                             dev, status);
1068         }
1069
1070         service = talloc_strdup(talloc_tos(), service_in);
1071         if (!service) {
1072                 *status = NT_STATUS_NO_MEMORY;
1073                 return NULL;
1074         }
1075
1076         if (!strlower_m(service)) {
1077                 DEBUG(2, ("strlower_m %s failed\n", service));
1078                 *status = NT_STATUS_INVALID_PARAMETER;
1079                 return NULL;
1080         }
1081
1082         snum = find_service(talloc_tos(), service, &service);
1083         if (!service) {
1084                 *status = NT_STATUS_NO_MEMORY;
1085                 return NULL;
1086         }
1087
1088         if (snum < 0) {
1089                 if (strequal(service,"IPC$") ||
1090                     (lp_enable_asu_support() && strequal(service,"ADMIN$"))) {
1091                         DEBUG(3,("refusing IPC connection to %s\n", service));
1092                         *status = NT_STATUS_ACCESS_DENIED;
1093                         return NULL;
1094                 }
1095
1096                 DEBUG(3,("%s (%s) couldn't find service %s\n",
1097                         get_remote_machine_name(),
1098                         tsocket_address_string(
1099                                 sconn->remote_address, talloc_tos()),
1100                         service));
1101                 *status = NT_STATUS_BAD_NETWORK_NAME;
1102                 return NULL;
1103         }
1104
1105         /* Handle non-Dfs clients attempting connections to msdfs proxy */
1106         if (lp_host_msdfs() && (*lp_msdfs_proxy(talloc_tos(), snum) != '\0'))  {
1107                 DEBUG(3, ("refusing connection to dfs proxy share '%s' "
1108                           "(pointing to %s)\n",
1109                         service, lp_msdfs_proxy(talloc_tos(), snum)));
1110                 *status = NT_STATUS_BAD_NETWORK_NAME;
1111                 return NULL;
1112         }
1113
1114         DEBUG(5, ("making a connection to 'normal' service %s\n", service));
1115
1116         return make_connection_smb1(req, now, snum, vuser,
1117                                     dev, status);
1118 }
1119
1120 /****************************************************************************
1121  Close a cnum.
1122 ****************************************************************************/
1123
1124 void close_cnum(connection_struct *conn, uint64_t vuid)
1125 {
1126         file_close_conn(conn);
1127
1128         if (!IS_IPC(conn)) {
1129                 dptr_closecnum(conn);
1130         }
1131
1132         change_to_root_user();
1133
1134         DEBUG(IS_IPC(conn)?3:2, ("%s (%s) closed connection to service %s\n",
1135                                  get_remote_machine_name(),
1136                                  tsocket_address_string(conn->sconn->remote_address,
1137                                                         talloc_tos()),
1138                                  lp_servicename(talloc_tos(), SNUM(conn))));
1139
1140         /* make sure we leave the directory available for unmount */
1141         vfs_ChDir(conn, "/");
1142
1143         /* Call VFS disconnect hook */
1144         SMB_VFS_DISCONNECT(conn);
1145
1146         /* execute any "postexec = " line */
1147         if (*lp_postexec(talloc_tos(), SNUM(conn)) &&
1148             change_to_user(conn, vuid))  {
1149                 char *cmd = talloc_sub_advanced(talloc_tos(),
1150                                         lp_servicename(talloc_tos(), SNUM(conn)),
1151                                         conn->session_info->unix_info->unix_name,
1152                                         conn->connectpath,
1153                                         conn->session_info->unix_token->gid,
1154                                         conn->session_info->unix_info->sanitized_username,
1155                                         conn->session_info->info->domain_name,
1156                                         lp_postexec(talloc_tos(), SNUM(conn)));
1157                 smbrun(cmd,NULL);
1158                 TALLOC_FREE(cmd);
1159                 change_to_root_user();
1160         }
1161
1162         change_to_root_user();
1163         /* execute any "root postexec = " line */
1164         if (*lp_root_postexec(talloc_tos(), SNUM(conn)))  {
1165                 char *cmd = talloc_sub_advanced(talloc_tos(),
1166                                         lp_servicename(talloc_tos(), SNUM(conn)),
1167                                         conn->session_info->unix_info->unix_name,
1168                                         conn->connectpath,
1169                                         conn->session_info->unix_token->gid,
1170                                         conn->session_info->unix_info->sanitized_username,
1171                                         conn->session_info->info->domain_name,
1172                                         lp_root_postexec(talloc_tos(), SNUM(conn)));
1173                 smbrun(cmd,NULL);
1174                 TALLOC_FREE(cmd);
1175         }
1176
1177         conn_free(conn);
1178 }