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 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 smbd_server_connection *sconn,
 521                                         connection_struct *conn,
 522                                         int snum, struct user_struct *vuser,
 523                                         const char *pdev)
 524 {
 525         struct smbXsrv_connection *xconn = sconn->conn;
 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(conn->params)) {
 682                 if (sconn->notify_ctx == NULL) {
 683                         sconn->notify_ctx = notify_init(
 684                                 sconn, sconn->msg_ctx, sconn->ev_ctx);
 685                 }
 686                 if (sconn->sys_notify_ctx == NULL) {
 687                         sconn->sys_notify_ctx = sys_notify_context_create(
 688                                 sconn, sconn->ev_ctx);
 689                 }
 690         }
 691
 692         if (lp_kernel_oplocks(snum)) {
 693                 init_kernel_oplocks(conn->sconn);
 694         }
 695
 696         /*
 697          * Fix compatibility issue pointed out by Volker.
 698          * We pass the conn->connectpath to the preexec
 699          * scripts as a parameter, so attempt to canonicalize
 700          * it here before calling the preexec scripts.
 701          * We ignore errors here, as it is possible that
 702          * the conn->connectpath doesn't exist yet and
 703          * the preexec scripts will create them.
 704          */
 705
 706         (void)canonicalize_connect_path(conn);
 707
 708         /* Preexecs are done here as they might make the dir we are to ChDir
 709          * to below */
 710         /* execute any "root preexec = " line */
 711         if (*lp_root_preexec(talloc_tos(), snum)) {
 712                 char *cmd = talloc_sub_advanced(talloc_tos(),
 713                                         lp_servicename(talloc_tos(), SNUM(conn)),
 714                                         conn->session_info->unix_info->unix_name,
 715                                         conn->connectpath,
 716                                         conn->session_info->unix_token->gid,
 717                                         conn->session_info->unix_info->sanitized_username,
 718                                         conn->session_info->info->domain_name,
 719                                         lp_root_preexec(talloc_tos(), snum));
 720                 DEBUG(5,("cmd=%s\n",cmd));
 721                 ret = smbrun(cmd,NULL);
 722                 TALLOC_FREE(cmd);
 723                 if (ret != 0 && lp_root_preexec_close(snum)) {
 724                         DEBUG(1,("root preexec gave %d - failing "
 725                                  "connection\n", ret));
 726                         status = NT_STATUS_ACCESS_DENIED;
 727                         goto err_root_exit;
 728                 }
 729         }
 730
 731 /* USER Activites: */
 732         if (!change_to_user(conn, conn->vuid)) {
 733                 /* No point continuing if they fail the basic checks */
 734                 DEBUG(0,("Can't become connected user!\n"));
 735                 status = NT_STATUS_LOGON_FAILURE;
 736                 goto err_root_exit;
 737         }
 738
 739         effuid = geteuid();
 740         effgid = getegid();
 741
 742         /* Remember that a different vuid can connect later without these
 743          * checks... */
 744
 745         /* Preexecs are done here as they might make the dir we are to ChDir
 746          * to below */
 747
 748         /* execute any "preexec = " line */
 749         if (*lp_preexec(talloc_tos(), snum)) {
 750                 char *cmd = talloc_sub_advanced(talloc_tos(),
 751                                         lp_servicename(talloc_tos(), SNUM(conn)),
 752                                         conn->session_info->unix_info->unix_name,
 753                                         conn->connectpath,
 754                                         conn->session_info->unix_token->gid,
 755                                         conn->session_info->unix_info->sanitized_username,
 756                                         conn->session_info->info->domain_name,
 757                                         lp_preexec(talloc_tos(), snum));
 758                 ret = smbrun(cmd,NULL);
 759                 TALLOC_FREE(cmd);
 760                 if (ret != 0 && lp_preexec_close(snum)) {
 761                         DEBUG(1,("preexec gave %d - failing connection\n",
 762                                  ret));
 763                         status = NT_STATUS_ACCESS_DENIED;
 764                         goto err_root_exit;
 765                 }
 766         }
 767
 768 #ifdef WITH_FAKE_KASERVER
 769         if (lp_afs_share(snum)) {
 770                 afs_login(conn);
 771         }
 772 #endif
 773
 774         /*
 775          * we've finished with the user stuff - go back to root
 776          * so the SMB_VFS_STAT call will only fail on path errors,
 777          * not permission problems.
 778          */
 779         change_to_root_user();
 780 /* ROOT Activites: */
 781
 782         /*
 783          * If widelinks are disallowed we need to canonicalise the connect
 784          * path here to ensure we don't have any symlinks in the
 785          * connectpath. We will be checking all paths on this connection are
 786          * below this directory. We must do this after the VFS init as we
 787          * depend on the realpath() pointer in the vfs table. JRA.
 788          */
 789         if (!lp_widelinks(snum)) {
 790                 if (!canonicalize_connect_path(conn)) {
 791                         DEBUG(0, ("canonicalize_connect_path failed "
 792                         "for service %s, path %s\n",
 793                                 lp_servicename(talloc_tos(), snum),
 794                                 conn->connectpath));
 795                         status = NT_STATUS_BAD_NETWORK_NAME;
 796                         goto err_root_exit;
 797                 }
 798         }
 799
 800         /* Add veto/hide lists */
 801         if (!IS_IPC(conn) && !IS_PRINT(conn)) {
 802                 set_namearray( &conn->veto_list,
 803                                lp_veto_files(talloc_tos(), snum));
 804                 set_namearray( &conn->hide_list,
 805                                lp_hide_files(talloc_tos(), snum));
 806                 set_namearray( &conn->veto_oplock_list,
 807                                lp_veto_oplock_files(talloc_tos(), snum));
 808                 set_namearray( &conn->aio_write_behind_list,
 809                                 lp_aio_write_behind(talloc_tos(), snum));
 810         }
 811         smb_fname_cpath = synthetic_smb_fname(talloc_tos(), conn->connectpath,
 812                                               NULL, NULL);
 813         if (smb_fname_cpath == NULL) {
 814                 status = NT_STATUS_NO_MEMORY;
 815                 goto err_root_exit;
 816         }
 817
 818         /* win2000 does not check the permissions on the directory
 819            during the tree connect, instead relying on permission
 820            check during individual operations. To match this behaviour
 821            I have disabled this chdir check (tridge) */
 822         /* the alternative is just to check the directory exists */
 823
 824         if ((ret = SMB_VFS_STAT(conn, smb_fname_cpath)) != 0 ||
 825             !S_ISDIR(smb_fname_cpath->st.st_ex_mode)) {
 826                 if (ret == 0 && !S_ISDIR(smb_fname_cpath->st.st_ex_mode)) {
 827                         DEBUG(0,("'%s' is not a directory, when connecting to "
 828                                  "[%s]\n", conn->connectpath,
 829                                  lp_servicename(talloc_tos(), snum)));
 830                 } else {
 831                         DEBUG(0,("'%s' does not exist or permission denied "
 832                                  "when connecting to [%s] Error was %s\n",
 833                                  conn->connectpath,
 834                                  lp_servicename(talloc_tos(), snum),
 835                                  strerror(errno) ));
 836                 }
 837                 status = NT_STATUS_BAD_NETWORK_NAME;
 838                 goto err_root_exit;
 839         }
 840         conn->base_share_dev = smb_fname_cpath->st.st_ex_dev;
 841
 842         talloc_free(conn->origpath);
 843         conn->origpath = talloc_strdup(conn, conn->connectpath);
 844
 845         /* Figure out the characteristics of the underlying filesystem. This
 846          * assumes that all the filesystem mounted withing a share path have
 847          * the same characteristics, which is likely but not guaranteed.
 848          */
 849
 850         conn->fs_capabilities = SMB_VFS_FS_CAPABILITIES(conn, &conn->ts_res);
 851
 852         /*
 853          * Print out the 'connected as' stuff here as we need
 854          * to know the effective uid and gid we will be using
 855          * (at least initially).
 856          */
 857
 858         if( DEBUGLVL( IS_IPC(conn) ? 3 : 2 ) ) {
 859                 dbgtext( "%s (%s) ", get_remote_machine_name(),
 860                          tsocket_address_string(conn->sconn->remote_address,
 861                                                 talloc_tos()) );
 862                 dbgtext( "%s", srv_is_signing_active(xconn) ? "signed " : "");
 863                 dbgtext( "connect to service %s ",
 864                          lp_servicename(talloc_tos(), snum) );
 865                 dbgtext( "initially as user %s ",
 866                          conn->session_info->unix_info->unix_name );
 867                 dbgtext( "(uid=%d, gid=%d) ", (int)effuid, (int)effgid );
 868                 dbgtext( "(pid %d)\n", (int)getpid() );
 869         }
 870
 871         return status;
 872
 873   err_root_exit:
 874
 875         TALLOC_FREE(smb_fname_cpath);
 876         /* We must exit this function as root. */
 877         if (geteuid() != 0) {
 878                 change_to_root_user();
 879         }
 880         if (on_err_call_dis_hook) {
 881                 /* Call VFS disconnect hook */
 882                 SMB_VFS_DISCONNECT(conn);
 883         }
 884         return status;
 885 }
 886
 887 /****************************************************************************
 888  Make a connection to a service from SMB1. Internal interface.
 889 ****************************************************************************/
 890
 891 static connection_struct *make_connection_smb1(struct smbd_server_connection *sconn,
 892                                         NTTIME now,
 893                                         int snum, struct user_struct *vuser,
 894                                         const char *pdev,
 895                                         NTSTATUS *pstatus)
 896 {
 897         struct smbXsrv_tcon *tcon;
 898         NTSTATUS status;
 899         struct connection_struct *conn;
 900
 901         status = smb1srv_tcon_create(sconn->conn, now, &tcon);
 902         if (!NT_STATUS_IS_OK(status)) {
 903                 DEBUG(0,("make_connection_smb1: Couldn't find free tcon %s.\n",
 904                          nt_errstr(status)));
 905                 *pstatus = status;
 906                 return NULL;
 907         }
 908
 909         conn = conn_new(sconn);
 910         if (!conn) {
 911                 TALLOC_FREE(tcon);
 912
 913                 DEBUG(0,("make_connection_smb1: Couldn't find free connection.\n"));
 914                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 915                 return NULL;
 916         }
 917
 918         conn->cnum = tcon->global->tcon_wire_id;
 919         conn->tcon = tcon;
 920
 921         *pstatus = make_connection_snum(sconn,
 922                                         conn,
 923                                         snum,
 924                                         vuser,
 925                                         pdev);
 926         if (!NT_STATUS_IS_OK(*pstatus)) {
 927                 conn_free(conn);
 928                 TALLOC_FREE(tcon);
 929                 return NULL;
 930         }
 931
 932         tcon->global->share_name = lp_servicename(tcon->global, SNUM(conn));
 933         if (tcon->global->share_name == NULL) {
 934                 conn_free(conn);
 935                 TALLOC_FREE(tcon);
 936                 *pstatus = NT_STATUS_NO_MEMORY;
 937                 return NULL;
 938         }
 939         tcon->global->session_global_id =
 940                 vuser->session->global->session_global_id;
 941
 942         tcon->compat = talloc_move(tcon, &conn);
 943         tcon->status = NT_STATUS_OK;
 944
 945         *pstatus = smbXsrv_tcon_update(tcon);
 946         if (!NT_STATUS_IS_OK(*pstatus)) {
 947                 TALLOC_FREE(tcon);
 948                 return NULL;
 949         }
 950
 951         return tcon->compat;
 952 }
 953
 954 /****************************************************************************
 955  Make a connection to a service from SMB2. External SMB2 interface.
 956  We must set cnum before claiming connection.
 957 ****************************************************************************/
 958
 959 connection_struct *make_connection_smb2(struct smbd_server_connection *sconn,
 960                                         struct smbXsrv_tcon *tcon,
 961                                         int snum,
 962                                         struct user_struct *vuser,
 963                                         const char *pdev,
 964                                         NTSTATUS *pstatus)
 965 {
 966         connection_struct *conn = conn_new(sconn);
 967         if (!conn) {
 968                 DEBUG(0,("make_connection_smb2: Couldn't find free connection.\n"));
 969                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 970                 return NULL;
 971         }
 972
 973         conn->cnum = tcon->global->tcon_wire_id;
 974         conn->tcon = tcon;
 975
 976         *pstatus = make_connection_snum(sconn,
 977                                         conn,
 978                                         snum,
 979                                         vuser,
 980                                         pdev);
 981         if (!NT_STATUS_IS_OK(*pstatus)) {
 982                 conn_free(conn);
 983                 return NULL;
 984         }
 985         return conn;
 986 }
 987
 988 /****************************************************************************
 989  Make a connection to a service. External SMB1 interface.
 990  *
 991  * @param service
 992 ****************************************************************************/
 993
 994 connection_struct *make_connection(struct smbd_server_connection *sconn,
 995                                    NTTIME now,
 996                                    const char *service_in,
 997                                    const char *pdev, uint64_t vuid,
 998                                    NTSTATUS *status)
 999 {
1000         uid_t euid;
1001         struct user_struct *vuser = NULL;
1002         char *service = NULL;
1003         fstring dev;
1004         int snum = -1;
1005
1006         fstrcpy(dev, pdev);
1007
1008         /* This must ONLY BE CALLED AS ROOT. As it exits this function as
1009          * root. */
1010         if (!non_root_mode() && (euid = geteuid()) != 0) {
1011                 DEBUG(0,("make_connection: PANIC ERROR. Called as nonroot "
1012                          "(%u)\n", (unsigned int)euid ));
1013                 smb_panic("make_connection: PANIC ERROR. Called as nonroot\n");
1014         }
1015
1016         if (conn_num_open(sconn) > 2047) {
1017                 *status = NT_STATUS_INSUFF_SERVER_RESOURCES;
1018                 return NULL;
1019         }
1020
1021         vuser = get_valid_user_struct(sconn, vuid);
1022         if (!vuser) {
1023                 DEBUG(1,("make_connection: refusing to connect with "
1024                          "no session setup\n"));
1025                 *status = NT_STATUS_ACCESS_DENIED;
1026                 return NULL;
1027         }
1028
1029         /* Logic to try and connect to the correct [homes] share, preferably
1030            without too many getpwnam() lookups.  This is particulary nasty for
1031            winbind usernames, where the share name isn't the same as unix
1032            username.
1033
1034            The snum of the homes share is stored on the vuser at session setup
1035            time.
1036         */
1037
1038         if (strequal(service_in,HOMES_NAME)) {
1039                 if (vuser->homes_snum == -1) {
1040                         DEBUG(2, ("[homes] share not available for "
1041                                   "this user because it was not found "
1042                                   "or created at session setup "
1043                                   "time\n"));
1044                         *status = NT_STATUS_BAD_NETWORK_NAME;
1045                         return NULL;
1046                 }
1047                 DEBUG(5, ("making a connection to [homes] service "
1048                           "created at session setup time\n"));
1049                 return make_connection_smb1(sconn, now,
1050                                             vuser->homes_snum,
1051                                             vuser,
1052                                             dev, status);
1053         } else if ((vuser->homes_snum != -1)
1054                    && strequal(service_in,
1055                                lp_servicename(talloc_tos(), vuser->homes_snum))) {
1056                 DEBUG(5, ("making a connection to 'homes' service [%s] "
1057                           "created at session setup time\n", service_in));
1058                 return make_connection_smb1(sconn, now,
1059                                             vuser->homes_snum,
1060                                             vuser,
1061                                             dev, status);
1062         }
1063
1064         service = talloc_strdup(talloc_tos(), service_in);
1065         if (!service) {
1066                 *status = NT_STATUS_NO_MEMORY;
1067                 return NULL;
1068         }
1069
1070         if (!strlower_m(service)) {
1071                 DEBUG(2, ("strlower_m %s failed\n", service));
1072                 *status = NT_STATUS_INVALID_PARAMETER;
1073                 return NULL;
1074         }
1075
1076         snum = find_service(talloc_tos(), service, &service);
1077         if (!service) {
1078                 *status = NT_STATUS_NO_MEMORY;
1079                 return NULL;
1080         }
1081
1082         if (snum < 0) {
1083                 if (strequal(service,"IPC$") ||
1084                     (lp_enable_asu_support() && strequal(service,"ADMIN$"))) {
1085                         DEBUG(3,("refusing IPC connection to %s\n", service));
1086                         *status = NT_STATUS_ACCESS_DENIED;
1087                         return NULL;
1088                 }
1089
1090                 DEBUG(3,("%s (%s) couldn't find service %s\n",
1091                         get_remote_machine_name(),
1092                         tsocket_address_string(
1093                                 sconn->remote_address, talloc_tos()),
1094                         service));
1095                 *status = NT_STATUS_BAD_NETWORK_NAME;
1096                 return NULL;
1097         }
1098
1099         /* Handle non-Dfs clients attempting connections to msdfs proxy */
1100         if (lp_host_msdfs() && (*lp_msdfs_proxy(talloc_tos(), snum) != '\0'))  {
1101                 DEBUG(3, ("refusing connection to dfs proxy share '%s' "
1102                           "(pointing to %s)\n",
1103                         service, lp_msdfs_proxy(talloc_tos(), snum)));
1104                 *status = NT_STATUS_BAD_NETWORK_NAME;
1105                 return NULL;
1106         }
1107
1108         DEBUG(5, ("making a connection to 'normal' service %s\n", service));
1109
1110         return make_connection_smb1(sconn, now, snum, vuser,
1111                                     dev, status);
1112 }
1113
1114 /****************************************************************************
1115  Close a cnum.
1116 ****************************************************************************/
1117
1118 void close_cnum(connection_struct *conn, uint64_t vuid)
1119 {
1120         file_close_conn(conn);
1121
1122         if (!IS_IPC(conn)) {
1123                 dptr_closecnum(conn);
1124         }
1125
1126         change_to_root_user();
1127
1128         DEBUG(IS_IPC(conn)?3:1, ("%s (%s) closed connection to service %s\n",
1129                                  get_remote_machine_name(),
1130                                  tsocket_address_string(conn->sconn->remote_address,
1131                                                         talloc_tos()),
1132                                  lp_servicename(talloc_tos(), SNUM(conn))));
1133
1134         /* Call VFS disconnect hook */
1135         SMB_VFS_DISCONNECT(conn);
1136
1137         /* make sure we leave the directory available for unmount */
1138         vfs_ChDir(conn, "/");
1139
1140         /* execute any "postexec = " line */
1141         if (*lp_postexec(talloc_tos(), SNUM(conn)) &&
1142             change_to_user(conn, vuid))  {
1143                 char *cmd = talloc_sub_advanced(talloc_tos(),
1144                                         lp_servicename(talloc_tos(), SNUM(conn)),
1145                                         conn->session_info->unix_info->unix_name,
1146                                         conn->connectpath,
1147                                         conn->session_info->unix_token->gid,
1148                                         conn->session_info->unix_info->sanitized_username,
1149                                         conn->session_info->info->domain_name,
1150                                         lp_postexec(talloc_tos(), SNUM(conn)));
1151                 smbrun(cmd,NULL);
1152                 TALLOC_FREE(cmd);
1153                 change_to_root_user();
1154         }
1155
1156         change_to_root_user();
1157         /* execute any "root postexec = " line */
1158         if (*lp_root_postexec(talloc_tos(), SNUM(conn)))  {
1159                 char *cmd = talloc_sub_advanced(talloc_tos(),
1160                                         lp_servicename(talloc_tos(), SNUM(conn)),
1161                                         conn->session_info->unix_info->unix_name,
1162                                         conn->connectpath,
1163                                         conn->session_info->unix_token->gid,
1164                                         conn->session_info->unix_info->sanitized_username,
1165                                         conn->session_info->info->domain_name,
1166                                         lp_root_postexec(talloc_tos(), SNUM(conn)));
1167                 smbrun(cmd,NULL);
1168                 TALLOC_FREE(cmd);
1169         }
1170
1171         conn_free(conn);
1172 }