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
  34 static bool canonicalize_connect_path(connection_struct *conn)
  35 {
  36         bool ret;
  37         char *resolved_name = SMB_VFS_REALPATH(conn,conn->connectpath);
  38         if (!resolved_name) {
  39                 return false;
  40         }
  41         ret = set_conn_connectpath(conn,resolved_name);
  42         SAFE_FREE(resolved_name);
  43         return ret;
  44 }
  45
  46 /****************************************************************************
  47  Ensure when setting connectpath it is a canonicalized (no ./ // or ../)
  48  absolute path stating in / and not ending in /.
  49  Observent people will notice a similarity between this and check_path_syntax :-).
  50 ****************************************************************************/
  51
  52 bool set_conn_connectpath(connection_struct *conn, const char *connectpath)
  53 {
  54         char *destname;
  55         char *d;
  56         const char *s = connectpath;
  57         bool start_of_name_component = true;
  58
  59         if (connectpath == NULL || connectpath[0] == '\0') {
  60                 return false;
  61         }
  62
  63         /* Allocate for strlen + '\0' + possible leading '/' */
  64         destname = (char *)talloc_size(conn, strlen(connectpath) + 2);
  65         if (!destname) {
  66                 return false;
  67         }
  68         d = destname;
  69
  70         *d++ = '/'; /* Always start with root. */
  71
  72         while (*s) {
  73                 if (*s == '/') {
  74                         /* Eat multiple '/' */
  75                         while (*s == '/') {
  76                                 s++;
  77                         }
  78                         if ((d > destname + 1) && (*s != '\0')) {
  79                                 *d++ = '/';
  80                         }
  81                         start_of_name_component = True;
  82                         continue;
  83                 }
  84
  85                 if (start_of_name_component) {
  86                         if ((s[0] == '.') && (s[1] == '.') && (s[2] == '/' || s[2] == '\0')) {
  87                                 /* Uh oh - "/../" or "/..\0" ! */
  88
  89                                 /* Go past the ../ or .. */
  90                                 if (s[2] == '/') {
  91                                         s += 3;
  92                                 } else {
  93                                         s += 2; /* Go past the .. */
  94                                 }
  95
  96                                 /* If  we just added a '/' - delete it */
  97                                 if ((d > destname) && (*(d-1) == '/')) {
  98                                         *(d-1) = '\0';
  99                                         d--;
 100                                 }
 101
 102                                 /* Are we at the start ? Can't go back further if so. */
 103                                 if (d <= destname) {
 104                                         *d++ = '/'; /* Can't delete root */
 105                                         continue;
 106                                 }
 107                                 /* Go back one level... */
 108                                 /* Decrement d first as d points to the *next* char to write into. */
 109                                 for (d--; d > destname; d--) {
 110                                         if (*d == '/') {
 111                                                 break;
 112                                         }
 113                                 }
 114                                 /* We're still at the start of a name component, just the previous one. */
 115                                 continue;
 116                         } else if ((s[0] == '.') && ((s[1] == '\0') || s[1] == '/')) {
 117                                 /* Component of pathname can't be "." only - skip the '.' . */
 118                                 if (s[1] == '/') {
 119                                         s += 2;
 120                                 } else {
 121                                         s++;
 122                                 }
 123                                 continue;
 124                         }
 125                 }
 126
 127                 if (!(*s & 0x80)) {
 128                         *d++ = *s++;
 129                 } else {
 130                         size_t siz;
 131                         /* Get the size of the next MB character. */
 132                         next_codepoint(s,&siz);
 133                         switch(siz) {
 134                                 case 5:
 135                                         *d++ = *s++;
 136                                         /*fall through*/
 137                                 case 4:
 138                                         *d++ = *s++;
 139                                         /*fall through*/
 140                                 case 3:
 141                                         *d++ = *s++;
 142                                         /*fall through*/
 143                                 case 2:
 144                                         *d++ = *s++;
 145                                         /*fall through*/
 146                                 case 1:
 147                                         *d++ = *s++;
 148                                         break;
 149                                 default:
 150                                         break;
 151                         }
 152                 }
 153                 start_of_name_component = false;
 154         }
 155         *d = '\0';
 156
 157         /* And must not end in '/' */
 158         if (d > destname + 1 && (*(d-1) == '/')) {
 159                 *(d-1) = '\0';
 160         }
 161
 162         DEBUG(10,("set_conn_connectpath: service %s, connectpath = %s\n",
 163                 lp_servicename(talloc_tos(), SNUM(conn)), destname ));
 164
 165         talloc_free(conn->connectpath);
 166         conn->connectpath = destname;
 167         /* Ensure conn->cwd is initialized - start as conn->connectpath. */
 168         TALLOC_FREE(conn->cwd);
 169         conn->cwd = talloc_strdup(conn, conn->connectpath);
 170         if (!conn->cwd) {
 171                 return false;
 172         }
 173         return true;
 174 }
 175
 176 /****************************************************************************
 177  Load parameters specific to a connection/service.
 178 ****************************************************************************/
 179
 180 bool set_current_service(connection_struct *conn, uint16 flags, bool do_chdir)
 181 {
 182         int snum;
 183
 184         if (!conn)  {
 185                 last_conn = NULL;
 186                 return(False);
 187         }
 188
 189         conn->lastused_count++;
 190
 191         snum = SNUM(conn);
 192
 193         if (do_chdir &&
 194             vfs_ChDir(conn,conn->connectpath) != 0 &&
 195             vfs_ChDir(conn,conn->origpath) != 0) {
 196                 DEBUG(((errno!=EACCES)?0:3),("chdir (%s) failed, reason: %s\n",
 197                          conn->connectpath, strerror(errno)));
 198                 return(False);
 199         }
 200
 201         if ((conn == last_conn) && (last_flags == flags)) {
 202                 return(True);
 203         }
 204
 205         last_conn = conn;
 206         last_flags = flags;
 207
 208         /* Obey the client case sensitivity requests - only for clients that support it. */
 209         switch (lp_casesensitive(snum)) {
 210                 case Auto:
 211                         {
 212                                 /* We need this uglyness due to DOS/Win9x clients that lie about case insensitivity. */
 213                                 enum remote_arch_types ra_type = get_remote_arch();
 214                                 if ((ra_type != RA_SAMBA) && (ra_type != RA_CIFSFS)) {
 215                                         /* Client can't support per-packet case sensitive pathnames. */
 216                                         conn->case_sensitive = False;
 217                                 } else {
 218                                         conn->case_sensitive = !(flags & FLAG_CASELESS_PATHNAMES);
 219                                 }
 220                         }
 221                         break;
 222                 case True:
 223                         conn->case_sensitive = True;
 224                         break;
 225                 default:
 226                         conn->case_sensitive = False;
 227                         break;
 228         }
 229         return(True);
 230 }
 231
 232 /****************************************************************************
 233  do some basic sainity checks on the share.
 234  This function modifies dev, ecode.
 235 ****************************************************************************/
 236
 237 static NTSTATUS share_sanity_checks(const struct tsocket_address *remote_address,
 238                                     const char *rhost,
 239                                     int snum,
 240                                     fstring dev)
 241 {
 242         char *raddr;
 243
 244         raddr = tsocket_address_inet_addr_string(remote_address,
 245                                                  talloc_tos());
 246         if (raddr == NULL) {
 247                 return NT_STATUS_NO_MEMORY;
 248         }
 249
 250         if (!lp_snum_ok(snum) ||
 251             !allow_access(lp_hostsdeny(snum), lp_hostsallow(snum),
 252                           rhost, raddr)) {
 253                 return NT_STATUS_ACCESS_DENIED;
 254         }
 255
 256         if (dev[0] == '?' || !dev[0]) {
 257                 if (lp_print_ok(snum)) {
 258                         fstrcpy(dev,"LPT1:");
 259                 } else if (strequal(lp_fstype(talloc_tos(), snum), "IPC")) {
 260                         fstrcpy(dev, "IPC");
 261                 } else {
 262                         fstrcpy(dev,"A:");
 263                 }
 264         }
 265
 266         if (!strupper_m(dev)) {
 267                 DEBUG(2,("strupper_m %s failed\n", dev));
 268                 return NT_STATUS_INVALID_PARAMETER;
 269         }
 270
 271         if (lp_print_ok(snum)) {
 272                 if (!strequal(dev, "LPT1:")) {
 273                         return NT_STATUS_BAD_DEVICE_TYPE;
 274                 }
 275         } else if (strequal(lp_fstype(talloc_tos(), snum), "IPC")) {
 276                 if (!strequal(dev, "IPC")) {
 277                         return NT_STATUS_BAD_DEVICE_TYPE;
 278                 }
 279         } else if (!strequal(dev, "A:")) {
 280                 return NT_STATUS_BAD_DEVICE_TYPE;
 281         }
 282
 283         /* Behave as a printer if we are supposed to */
 284         if (lp_print_ok(snum) && (strcmp(dev, "A:") == 0)) {
 285                 fstrcpy(dev, "LPT1:");
 286         }
 287
 288         return NT_STATUS_OK;
 289 }
 290
 291 /*
 292  * Go through lookup_name etc to find the force'd group.
 293  *
 294  * Create a new token from src_token, replacing the primary group sid with the
 295  * one found.
 296  */
 297
 298 static NTSTATUS find_forced_group(bool force_user,
 299                                   int snum, const char *username,
 300                                   struct dom_sid *pgroup_sid,
 301                                   gid_t *pgid)
 302 {
 303         NTSTATUS result = NT_STATUS_NO_SUCH_GROUP;
 304         TALLOC_CTX *frame = talloc_stackframe();
 305         struct dom_sid group_sid;
 306         enum lsa_SidType type;
 307         char *groupname;
 308         bool user_must_be_member = False;
 309         gid_t gid;
 310
 311         groupname = lp_force_group(talloc_tos(), snum);
 312         if (groupname == NULL) {
 313                 DEBUG(1, ("talloc_strdup failed\n"));
 314                 result = NT_STATUS_NO_MEMORY;
 315                 goto done;
 316         }
 317
 318         if (groupname[0] == '+') {
 319                 user_must_be_member = True;
 320                 groupname += 1;
 321         }
 322
 323         groupname = talloc_string_sub(talloc_tos(), groupname,
 324                                       "%S", lp_servicename(talloc_tos(), snum));
 325         if (groupname == NULL) {
 326                 DEBUG(1, ("talloc_string_sub failed\n"));
 327                 result = NT_STATUS_NO_MEMORY;
 328                 goto done;
 329         }
 330
 331         if (!lookup_name_smbconf(talloc_tos(), groupname,
 332                          LOOKUP_NAME_ALL|LOOKUP_NAME_GROUP,
 333                          NULL, NULL, &group_sid, &type)) {
 334                 DEBUG(10, ("lookup_name_smbconf(%s) failed\n",
 335                            groupname));
 336                 goto done;
 337         }
 338
 339         if ((type != SID_NAME_DOM_GRP) && (type != SID_NAME_ALIAS) &&
 340             (type != SID_NAME_WKN_GRP)) {
 341                 DEBUG(10, ("%s is a %s, not a group\n", groupname,
 342                            sid_type_lookup(type)));
 343                 goto done;
 344         }
 345
 346         if (!sid_to_gid(&group_sid, &gid)) {
 347                 DEBUG(10, ("sid_to_gid(%s) for %s failed\n",
 348                            sid_string_dbg(&group_sid), groupname));
 349                 goto done;
 350         }
 351
 352         /*
 353          * If the user has been forced and the forced group starts with a '+',
 354          * then we only set the group to be the forced group if the forced
 355          * user is a member of that group.  Otherwise, the meaning of the '+'
 356          * would be ignored.
 357          */
 358
 359         if (force_user && user_must_be_member) {
 360                 if (user_in_group_sid(username, &group_sid)) {
 361                         sid_copy(pgroup_sid, &group_sid);
 362                         *pgid = gid;
 363                         DEBUG(3,("Forced group %s for member %s\n",
 364                                  groupname, username));
 365                 } else {
 366                         DEBUG(0,("find_forced_group: forced user %s is not a member "
 367                                 "of forced group %s. Disallowing access.\n",
 368                                 username, groupname ));
 369                         result = NT_STATUS_MEMBER_NOT_IN_GROUP;
 370                         goto done;
 371                 }
 372         } else {
 373                 sid_copy(pgroup_sid, &group_sid);
 374                 *pgid = gid;
 375                 DEBUG(3,("Forced group %s\n", groupname));
 376         }
 377
 378         result = NT_STATUS_OK;
 379  done:
 380         TALLOC_FREE(frame);
 381         return result;
 382 }
 383
 384 /****************************************************************************
 385   Create an auth_session_info structure for a connection_struct
 386 ****************************************************************************/
 387
 388 static NTSTATUS create_connection_session_info(struct smbd_server_connection *sconn,
 389                                               TALLOC_CTX *mem_ctx, int snum,
 390                                               struct auth_session_info *session_info,
 391                                               struct auth_session_info **presult)
 392 {
 393         struct auth_session_info *result;
 394
 395         if (lp_guest_only(snum)) {
 396                 return make_session_info_guest(mem_ctx, presult);
 397         }
 398
 399         /*
 400          * This is the normal security != share case where we have a
 401          * valid vuid from the session setup.                 */
 402
 403         if (security_session_user_level(session_info, NULL) < SECURITY_USER) {
 404                 if (!lp_guest_ok(snum)) {
 405                         DEBUG(2, ("guest user (from session setup) "
 406                                   "not permitted to access this share "
 407                                   "(%s)\n", lp_servicename(talloc_tos(), snum)));
 408                         return NT_STATUS_ACCESS_DENIED;
 409                 }
 410         } else {
 411                 if (!user_ok_token(session_info->unix_info->unix_name,
 412                                    session_info->info->domain_name,
 413                                    session_info->security_token, snum)) {
 414                         DEBUG(2, ("user '%s' (from session setup) not "
 415                                   "permitted to access this share "
 416                                   "(%s)\n",
 417                                   session_info->unix_info->unix_name,
 418                                   lp_servicename(talloc_tos(), snum)));
 419                         return NT_STATUS_ACCESS_DENIED;
 420                 }
 421         }
 422
 423         result = copy_session_info(mem_ctx, session_info);
 424         if (result == NULL) {
 425                 return NT_STATUS_NO_MEMORY;
 426         }
 427
 428         *presult = result;
 429         return NT_STATUS_OK;
 430 }
 431
 432 /****************************************************************************
 433   set relavent user and group settings corresponding to force user/group
 434   configuration for the given snum.
 435 ****************************************************************************/
 436
 437 NTSTATUS set_conn_force_user_group(connection_struct *conn, int snum)
 438 {
 439         NTSTATUS status;
 440
 441         if (*lp_force_user(talloc_tos(), snum)) {
 442
 443                 /*
 444                  * Replace conn->session_info with a completely faked up one
 445                  * from the username we are forced into :-)
 446                  */
 447
 448                 char *fuser;
 449                 char *sanitized_username;
 450                 struct auth_session_info *forced_serverinfo;
 451                 bool guest;
 452
 453                 fuser = talloc_string_sub(conn, lp_force_user(talloc_tos(), snum), "%S",
 454                                           lp_const_servicename(snum));
 455                 if (fuser == NULL) {
 456                         return NT_STATUS_NO_MEMORY;
 457                 }
 458
 459                 guest = security_session_user_level(conn->session_info, NULL) < SECURITY_USER;
 460
 461                 status = make_session_info_from_username(
 462                         conn, fuser,
 463                         guest,
 464                         &forced_serverinfo);
 465                 if (!NT_STATUS_IS_OK(status)) {
 466                         return status;
 467                 }
 468
 469                 /* We don't want to replace the original sanitized_username
 470                    as it is the original user given in the connect attempt.
 471                    This is used in '%U' substitutions. */
 472                 sanitized_username = discard_const_p(char,
 473                         forced_serverinfo->unix_info->sanitized_username);
 474                 TALLOC_FREE(sanitized_username);
 475                 forced_serverinfo->unix_info->sanitized_username =
 476                         talloc_move(forced_serverinfo->unix_info,
 477                                 &conn->session_info->unix_info->sanitized_username);
 478
 479                 TALLOC_FREE(conn->session_info);
 480                 conn->session_info = forced_serverinfo;
 481
 482                 conn->force_user = true;
 483                 DEBUG(3,("Forced user %s\n", fuser));
 484         }
 485
 486         /*
 487          * If force group is true, then override
 488          * any groupid stored for the connecting user.
 489          */
 490
 491         if (*lp_force_group(talloc_tos(), snum)) {
 492
 493                 status = find_forced_group(
 494                         conn->force_user, snum, conn->session_info->unix_info->unix_name,
 495                         &conn->session_info->security_token->sids[1],
 496                         &conn->session_info->unix_token->gid);
 497
 498                 if (!NT_STATUS_IS_OK(status)) {
 499                         return status;
 500                 }
 501
 502                 /*
 503                  * We need to cache this gid, to use within
 504                  * change_to_user() separately from the conn->session_info
 505                  * struct. We only use conn->session_info directly if
 506                  * "force_user" was set.
 507                  */
 508                 conn->force_group_gid = conn->session_info->unix_token->gid;
 509         }
 510
 511         return NT_STATUS_OK;
 512 }
 513
 514 /****************************************************************************
 515   Make a connection, given the snum to connect to, and the vuser of the
 516   connecting user if appropriate.
 517 ****************************************************************************/
 518
 519 static NTSTATUS make_connection_snum(struct smbd_server_connection *sconn,
 520                                         connection_struct *conn,
 521                                         int snum, struct user_struct *vuser,
 522                                         const char *pdev)
 523 {
 524         struct smb_filename *smb_fname_cpath = NULL;
 525         fstring dev;
 526         int ret;
 527         bool on_err_call_dis_hook = false;
 528         uid_t effuid;
 529         gid_t effgid;
 530         NTSTATUS status;
 531
 532         fstrcpy(dev, pdev);
 533
 534         status = share_sanity_checks(sconn->remote_address,
 535                                        sconn->remote_hostname,
 536                                        snum,
 537                                        dev);
 538         if (NT_STATUS_IS_ERR(status)) {
 539                 goto err_root_exit;
 540         }
 541
 542         conn->params->service = snum;
 543
 544         status = create_connection_session_info(sconn,
 545                 conn, snum, vuser->session_info,
 546                 &conn->session_info);
 547
 548         if (!NT_STATUS_IS_OK(status)) {
 549                 DEBUG(1, ("create_connection_session_info failed: %s\n",
 550                           nt_errstr(status)));
 551                 goto err_root_exit;
 552         }
 553
 554         if (lp_guest_only(snum)) {
 555                 conn->force_user = true;
 556         }
 557
 558         conn->num_files_open = 0;
 559         conn->lastused = conn->lastused_count = time(NULL);
 560         conn->printer = (strncmp(dev,"LPT",3) == 0);
 561         conn->ipc = ( (strncmp(dev,"IPC",3) == 0) ||
 562                       ( lp_enable_asu_support() && strequal(dev,"ADMIN$")) );
 563
 564         /* Case options for the share. */
 565         if (lp_casesensitive(snum) == Auto) {
 566                 /* We will be setting this per packet. Set to be case
 567                  * insensitive for now. */
 568                 conn->case_sensitive = False;
 569         } else {
 570                 conn->case_sensitive = (bool)lp_casesensitive(snum);
 571         }
 572
 573         conn->case_preserve = lp_preservecase(snum);
 574         conn->short_case_preserve = lp_shortpreservecase(snum);
 575
 576         conn->encrypt_level = lp_smb_encrypt(snum);
 577
 578         conn->veto_list = NULL;
 579         conn->hide_list = NULL;
 580         conn->veto_oplock_list = NULL;
 581         conn->aio_write_behind_list = NULL;
 582
 583         conn->read_only = lp_readonly(SNUM(conn));
 584
 585         status = set_conn_force_user_group(conn, snum);
 586         if (!NT_STATUS_IS_OK(status)) {
 587                 goto err_root_exit;
 588         }
 589
 590         conn->vuid = vuser->vuid;
 591
 592         {
 593                 char *s = talloc_sub_advanced(talloc_tos(),
 594                                         lp_servicename(talloc_tos(), SNUM(conn)),
 595                                         conn->session_info->unix_info->unix_name,
 596                                         conn->connectpath,
 597                                         conn->session_info->unix_token->gid,
 598                                         conn->session_info->unix_info->sanitized_username,
 599                                         conn->session_info->info->domain_name,
 600                                         lp_pathname(talloc_tos(), snum));
 601                 if (!s) {
 602                         status = NT_STATUS_NO_MEMORY;
 603                         goto err_root_exit;
 604                 }
 605
 606                 if (!set_conn_connectpath(conn,s)) {
 607                         TALLOC_FREE(s);
 608                         status = NT_STATUS_NO_MEMORY;
 609                         goto err_root_exit;
 610                 }
 611                 DEBUG(3,("Connect path is '%s' for service [%s]\n",s,
 612                          lp_servicename(talloc_tos(), snum)));
 613                 TALLOC_FREE(s);
 614         }
 615
 616         /*
 617          * Set up the share security descripter.
 618          * NOTE - we use the *INCOMING USER* session_info
 619          * here, as does (indirectly) change_to_user(),
 620          * which can be called on any incoming packet.
 621          * This way we set up the share access based
 622          * on the authenticated user, not the forced
 623          * user. See bug:
 624          *
 625          * https://bugzilla.samba.org/show_bug.cgi?id=9878
 626          */
 627
 628         status = check_user_share_access(conn,
 629                                         vuser->session_info,
 630                                         &conn->share_access,
 631                                         &conn->read_only);
 632         if (!NT_STATUS_IS_OK(status)) {
 633                 goto err_root_exit;
 634         }
 635
 636         /* Initialise VFS function pointers */
 637
 638         if (!smbd_vfs_init(conn)) {
 639                 DEBUG(0, ("vfs_init failed for service %s\n",
 640                           lp_servicename(talloc_tos(), snum)));
 641                 status = NT_STATUS_BAD_NETWORK_NAME;
 642                 goto err_root_exit;
 643         }
 644
 645 /* ROOT Activities: */
 646         /* explicitly check widelinks here so that we can correctly warn
 647          * in the logs. */
 648         widelinks_warning(snum);
 649
 650         /*
 651          * Enforce the max connections parameter.
 652          */
 653
 654         if ((lp_max_connections(snum) > 0)
 655             && (count_current_connections(lp_servicename(talloc_tos(), SNUM(conn)), True) >=
 656                 lp_max_connections(snum))) {
 657
 658                 DEBUG(1, ("Max connections (%d) exceeded for %s\n",
 659                           lp_max_connections(snum),
 660                           lp_servicename(talloc_tos(), snum)));
 661                 status = NT_STATUS_INSUFFICIENT_RESOURCES;
 662                 goto err_root_exit;
 663         }
 664
 665         /* Invoke VFS make connection hook - this must be the first
 666            filesystem operation that we do. */
 667
 668         if (SMB_VFS_CONNECT(conn, lp_servicename(talloc_tos(), snum),
 669                             conn->session_info->unix_info->unix_name) < 0) {
 670                 DEBUG(0,("make_connection: VFS make connection failed!\n"));
 671                 status = NT_STATUS_UNSUCCESSFUL;
 672                 goto err_root_exit;
 673         }
 674
 675         /* Any error exit after here needs to call the disconnect hook. */
 676         on_err_call_dis_hook = true;
 677
 678         if ((!conn->printer) && (!conn->ipc) &&
 679             lp_change_notify(conn->params)) {
 680                 if (sconn->notify_ctx == NULL) {
 681                         sconn->notify_ctx = notify_init(
 682                                 sconn, sconn->msg_ctx, sconn->ev_ctx);
 683                 }
 684                 if (sconn->sys_notify_ctx == NULL) {
 685                         sconn->sys_notify_ctx = sys_notify_context_create(
 686                                 sconn, sconn->ev_ctx);
 687                 }
 688         }
 689
 690         if (lp_kernel_oplocks(snum)) {
 691                 init_kernel_oplocks(conn->sconn);
 692         }
 693
 694         /*
 695          * Fix compatibility issue pointed out by Volker.
 696          * We pass the conn->connectpath to the preexec
 697          * scripts as a parameter, so attempt to canonicalize
 698          * it here before calling the preexec scripts.
 699          * We ignore errors here, as it is possible that
 700          * the conn->connectpath doesn't exist yet and
 701          * the preexec scripts will create them.
 702          */
 703
 704         (void)canonicalize_connect_path(conn);
 705
 706         /* Preexecs are done here as they might make the dir we are to ChDir
 707          * to below */
 708         /* execute any "root preexec = " line */
 709         if (*lp_rootpreexec(talloc_tos(), snum)) {
 710                 char *cmd = talloc_sub_advanced(talloc_tos(),
 711                                         lp_servicename(talloc_tos(), SNUM(conn)),
 712                                         conn->session_info->unix_info->unix_name,
 713                                         conn->connectpath,
 714                                         conn->session_info->unix_token->gid,
 715                                         conn->session_info->unix_info->sanitized_username,
 716                                         conn->session_info->info->domain_name,
 717                                         lp_rootpreexec(talloc_tos(), snum));
 718                 DEBUG(5,("cmd=%s\n",cmd));
 719                 ret = smbrun(cmd,NULL);
 720                 TALLOC_FREE(cmd);
 721                 if (ret != 0 && lp_rootpreexec_close(snum)) {
 722                         DEBUG(1,("root preexec gave %d - failing "
 723                                  "connection\n", ret));
 724                         status = NT_STATUS_ACCESS_DENIED;
 725                         goto err_root_exit;
 726                 }
 727         }
 728
 729 /* USER Activites: */
 730         if (!change_to_user(conn, conn->vuid)) {
 731                 /* No point continuing if they fail the basic checks */
 732                 DEBUG(0,("Can't become connected user!\n"));
 733                 status = NT_STATUS_LOGON_FAILURE;
 734                 goto err_root_exit;
 735         }
 736
 737         effuid = geteuid();
 738         effgid = getegid();
 739
 740         /* Remember that a different vuid can connect later without these
 741          * checks... */
 742
 743         /* Preexecs are done here as they might make the dir we are to ChDir
 744          * to below */
 745
 746         /* execute any "preexec = " line */
 747         if (*lp_preexec(talloc_tos(), snum)) {
 748                 char *cmd = talloc_sub_advanced(talloc_tos(),
 749                                         lp_servicename(talloc_tos(), SNUM(conn)),
 750                                         conn->session_info->unix_info->unix_name,
 751                                         conn->connectpath,
 752                                         conn->session_info->unix_token->gid,
 753                                         conn->session_info->unix_info->sanitized_username,
 754                                         conn->session_info->info->domain_name,
 755                                         lp_preexec(talloc_tos(), snum));
 756                 ret = smbrun(cmd,NULL);
 757                 TALLOC_FREE(cmd);
 758                 if (ret != 0 && lp_preexec_close(snum)) {
 759                         DEBUG(1,("preexec gave %d - failing connection\n",
 760                                  ret));
 761                         status = NT_STATUS_ACCESS_DENIED;
 762                         goto err_root_exit;
 763                 }
 764         }
 765
 766 #ifdef WITH_FAKE_KASERVER
 767         if (lp_afs_share(snum)) {
 768                 afs_login(conn);
 769         }
 770 #endif
 771
 772         /*
 773          * we've finished with the user stuff - go back to root
 774          * so the SMB_VFS_STAT call will only fail on path errors,
 775          * not permission problems.
 776          */
 777         change_to_root_user();
 778 /* ROOT Activites: */
 779
 780         /*
 781          * If widelinks are disallowed we need to canonicalise the connect
 782          * path here to ensure we don't have any symlinks in the
 783          * connectpath. We will be checking all paths on this connection are
 784          * below this directory. We must do this after the VFS init as we
 785          * depend on the realpath() pointer in the vfs table. JRA.
 786          */
 787         if (!lp_widelinks(snum)) {
 788                 if (!canonicalize_connect_path(conn)) {
 789                         DEBUG(0, ("canonicalize_connect_path failed "
 790                         "for service %s, path %s\n",
 791                                 lp_servicename(talloc_tos(), snum),
 792                                 conn->connectpath));
 793                         status = NT_STATUS_BAD_NETWORK_NAME;
 794                         goto err_root_exit;
 795                 }
 796         }
 797
 798         /* Add veto/hide lists */
 799         if (!IS_IPC(conn) && !IS_PRINT(conn)) {
 800                 set_namearray( &conn->veto_list,
 801                                lp_veto_files(talloc_tos(), snum));
 802                 set_namearray( &conn->hide_list,
 803                                lp_hide_files(talloc_tos(), snum));
 804                 set_namearray( &conn->veto_oplock_list,
 805                                lp_veto_oplocks(talloc_tos(), snum));
 806                 set_namearray( &conn->aio_write_behind_list,
 807                                 lp_aio_write_behind(talloc_tos(), snum));
 808         }
 809         status = create_synthetic_smb_fname(talloc_tos(), conn->connectpath,
 810                                             NULL, NULL, &smb_fname_cpath);
 811         if (!NT_STATUS_IS_OK(status)) {
 812                 goto err_root_exit;
 813         }
 814
 815         /* win2000 does not check the permissions on the directory
 816            during the tree connect, instead relying on permission
 817            check during individual operations. To match this behaviour
 818            I have disabled this chdir check (tridge) */
 819         /* the alternative is just to check the directory exists */
 820
 821         if ((ret = SMB_VFS_STAT(conn, smb_fname_cpath)) != 0 ||
 822             !S_ISDIR(smb_fname_cpath->st.st_ex_mode)) {
 823                 if (ret == 0 && !S_ISDIR(smb_fname_cpath->st.st_ex_mode)) {
 824                         DEBUG(0,("'%s' is not a directory, when connecting to "
 825                                  "[%s]\n", conn->connectpath,
 826                                  lp_servicename(talloc_tos(), snum)));
 827                 } else {
 828                         DEBUG(0,("'%s' does not exist or permission denied "
 829                                  "when connecting to [%s] Error was %s\n",
 830                                  conn->connectpath,
 831                                  lp_servicename(talloc_tos(), snum),
 832                                  strerror(errno) ));
 833                 }
 834                 status = NT_STATUS_BAD_NETWORK_NAME;
 835                 goto err_root_exit;
 836         }
 837         conn->base_share_dev = smb_fname_cpath->st.st_ex_dev;
 838
 839         talloc_free(conn->origpath);
 840         conn->origpath = talloc_strdup(conn, conn->connectpath);
 841
 842         /* Figure out the characteristics of the underlying filesystem. This
 843          * assumes that all the filesystem mounted withing a share path have
 844          * the same characteristics, which is likely but not guaranteed.
 845          */
 846
 847         conn->fs_capabilities = SMB_VFS_FS_CAPABILITIES(conn, &conn->ts_res);
 848
 849         /*
 850          * Print out the 'connected as' stuff here as we need
 851          * to know the effective uid and gid we will be using
 852          * (at least initially).
 853          */
 854
 855         if( DEBUGLVL( IS_IPC(conn) ? 3 : 1 ) ) {
 856                 dbgtext( "%s (%s) ", get_remote_machine_name(),
 857                          tsocket_address_string(conn->sconn->remote_address,
 858                                                 talloc_tos()) );
 859                 dbgtext( "%s", srv_is_signing_active(sconn) ? "signed " : "");
 860                 dbgtext( "connect to service %s ",
 861                          lp_servicename(talloc_tos(), snum) );
 862                 dbgtext( "initially as user %s ",
 863                          conn->session_info->unix_info->unix_name );
 864                 dbgtext( "(uid=%d, gid=%d) ", (int)effuid, (int)effgid );
 865                 dbgtext( "(pid %d)\n", (int)getpid() );
 866         }
 867
 868         return status;
 869
 870   err_root_exit:
 871
 872         TALLOC_FREE(smb_fname_cpath);
 873         /* We must exit this function as root. */
 874         if (geteuid() != 0) {
 875                 change_to_root_user();
 876         }
 877         if (on_err_call_dis_hook) {
 878                 /* Call VFS disconnect hook */
 879                 SMB_VFS_DISCONNECT(conn);
 880         }
 881         return status;
 882 }
 883
 884 /****************************************************************************
 885  Make a connection to a service from SMB1. Internal interface.
 886 ****************************************************************************/
 887
 888 static connection_struct *make_connection_smb1(struct smbd_server_connection *sconn,
 889                                         NTTIME now,
 890                                         int snum, struct user_struct *vuser,
 891                                         const char *pdev,
 892                                         NTSTATUS *pstatus)
 893 {
 894         struct smbXsrv_tcon *tcon;
 895         NTSTATUS status;
 896         struct connection_struct *conn;
 897
 898         status = smb1srv_tcon_create(sconn->conn, now, &tcon);
 899         if (!NT_STATUS_IS_OK(status)) {
 900                 DEBUG(0,("make_connection_smb1: Couldn't find free tcon %s.\n",
 901                          nt_errstr(status)));
 902                 *pstatus = status;
 903                 return NULL;
 904         }
 905
 906         conn = conn_new(sconn);
 907         if (!conn) {
 908                 TALLOC_FREE(tcon);
 909
 910                 DEBUG(0,("make_connection_smb1: Couldn't find free connection.\n"));
 911                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 912                 return NULL;
 913         }
 914
 915         conn->cnum = tcon->global->tcon_wire_id;
 916         conn->tcon = tcon;
 917
 918         *pstatus = make_connection_snum(sconn,
 919                                         conn,
 920                                         snum,
 921                                         vuser,
 922                                         pdev);
 923         if (!NT_STATUS_IS_OK(*pstatus)) {
 924                 conn_free(conn);
 925                 TALLOC_FREE(tcon);
 926                 return NULL;
 927         }
 928
 929         tcon->global->share_name = lp_servicename(tcon->global, SNUM(conn));
 930         if (tcon->global->share_name == NULL) {
 931                 conn_free(conn);
 932                 TALLOC_FREE(tcon);
 933                 *pstatus = NT_STATUS_NO_MEMORY;
 934                 return NULL;
 935         }
 936         tcon->global->session_global_id =
 937                 vuser->session->global->session_global_id;
 938
 939         tcon->compat = talloc_move(tcon, &conn);
 940         tcon->status = NT_STATUS_OK;
 941
 942         *pstatus = smbXsrv_tcon_update(tcon);
 943         if (!NT_STATUS_IS_OK(*pstatus)) {
 944                 TALLOC_FREE(tcon);
 945                 return NULL;
 946         }
 947
 948         return tcon->compat;
 949 }
 950
 951 /****************************************************************************
 952  Make a connection to a service from SMB2. External SMB2 interface.
 953  We must set cnum before claiming connection.
 954 ****************************************************************************/
 955
 956 connection_struct *make_connection_smb2(struct smbd_server_connection *sconn,
 957                                         struct smbXsrv_tcon *tcon,
 958                                         int snum,
 959                                         struct user_struct *vuser,
 960                                         const char *pdev,
 961                                         NTSTATUS *pstatus)
 962 {
 963         connection_struct *conn = conn_new(sconn);
 964         if (!conn) {
 965                 DEBUG(0,("make_connection_smb2: Couldn't find free connection.\n"));
 966                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
 967                 return NULL;
 968         }
 969
 970         conn->cnum = tcon->global->tcon_wire_id;
 971         conn->tcon = tcon;
 972
 973         *pstatus = make_connection_snum(sconn,
 974                                         conn,
 975                                         snum,
 976                                         vuser,
 977                                         pdev);
 978         if (!NT_STATUS_IS_OK(*pstatus)) {
 979                 conn_free(conn);
 980                 return NULL;
 981         }
 982         return conn;
 983 }
 984
 985 /****************************************************************************
 986  Make a connection to a service. External SMB1 interface.
 987  *
 988  * @param service
 989 ****************************************************************************/
 990
 991 connection_struct *make_connection(struct smbd_server_connection *sconn,
 992                                    NTTIME now,
 993                                    const char *service_in,
 994                                    const char *pdev, uint64_t vuid,
 995                                    NTSTATUS *status)
 996 {
 997         uid_t euid;
 998         struct user_struct *vuser = NULL;
 999         char *service = NULL;
1000         fstring dev;
1001         int snum = -1;
1002
1003         fstrcpy(dev, pdev);
1004
1005         /* This must ONLY BE CALLED AS ROOT. As it exits this function as
1006          * root. */
1007         if (!non_root_mode() && (euid = geteuid()) != 0) {
1008                 DEBUG(0,("make_connection: PANIC ERROR. Called as nonroot "
1009                          "(%u)\n", (unsigned int)euid ));
1010                 smb_panic("make_connection: PANIC ERROR. Called as nonroot\n");
1011         }
1012
1013         if (conn_num_open(sconn) > 2047) {
1014                 *status = NT_STATUS_INSUFF_SERVER_RESOURCES;
1015                 return NULL;
1016         }
1017
1018         vuser = get_valid_user_struct(sconn, vuid);
1019         if (!vuser) {
1020                 DEBUG(1,("make_connection: refusing to connect with "
1021                          "no session setup\n"));
1022                 *status = NT_STATUS_ACCESS_DENIED;
1023                 return NULL;
1024         }
1025
1026         /* Logic to try and connect to the correct [homes] share, preferably
1027            without too many getpwnam() lookups.  This is particulary nasty for
1028            winbind usernames, where the share name isn't the same as unix
1029            username.
1030
1031            The snum of the homes share is stored on the vuser at session setup
1032            time.
1033         */
1034
1035         if (strequal(service_in,HOMES_NAME)) {
1036                 if (vuser->homes_snum == -1) {
1037                         DEBUG(2, ("[homes] share not available for "
1038                                   "this user because it was not found "
1039                                   "or created at session setup "
1040                                   "time\n"));
1041                         *status = NT_STATUS_BAD_NETWORK_NAME;
1042                         return NULL;
1043                 }
1044                 DEBUG(5, ("making a connection to [homes] service "
1045                           "created at session setup time\n"));
1046                 return make_connection_smb1(sconn, now,
1047                                             vuser->homes_snum,
1048                                             vuser,
1049                                             dev, status);
1050         } else if ((vuser->homes_snum != -1)
1051                    && strequal(service_in,
1052                                lp_servicename(talloc_tos(), vuser->homes_snum))) {
1053                 DEBUG(5, ("making a connection to 'homes' service [%s] "
1054                           "created at session setup time\n", service_in));
1055                 return make_connection_smb1(sconn, now,
1056                                             vuser->homes_snum,
1057                                             vuser,
1058                                             dev, status);
1059         }
1060
1061         service = talloc_strdup(talloc_tos(), service_in);
1062         if (!service) {
1063                 *status = NT_STATUS_NO_MEMORY;
1064                 return NULL;
1065         }
1066
1067         if (!strlower_m(service)) {
1068                 DEBUG(2, ("strlower_m %s failed\n", service));
1069                 *status = NT_STATUS_INVALID_PARAMETER;
1070                 return NULL;
1071         }
1072
1073         snum = find_service(talloc_tos(), service, &service);
1074         if (!service) {
1075                 *status = NT_STATUS_NO_MEMORY;
1076                 return NULL;
1077         }
1078
1079         if (snum < 0) {
1080                 if (strequal(service,"IPC$") ||
1081                     (lp_enable_asu_support() && strequal(service,"ADMIN$"))) {
1082                         DEBUG(3,("refusing IPC connection to %s\n", service));
1083                         *status = NT_STATUS_ACCESS_DENIED;
1084                         return NULL;
1085                 }
1086
1087                 DEBUG(3,("%s (%s) couldn't find service %s\n",
1088                         get_remote_machine_name(),
1089                         tsocket_address_string(
1090                                 sconn->remote_address, talloc_tos()),
1091                         service));
1092                 *status = NT_STATUS_BAD_NETWORK_NAME;
1093                 return NULL;
1094         }
1095
1096         /* Handle non-Dfs clients attempting connections to msdfs proxy */
1097         if (lp_host_msdfs() && (*lp_msdfs_proxy(talloc_tos(), snum) != '\0'))  {
1098                 DEBUG(3, ("refusing connection to dfs proxy share '%s' "
1099                           "(pointing to %s)\n",
1100                         service, lp_msdfs_proxy(talloc_tos(), snum)));
1101                 *status = NT_STATUS_BAD_NETWORK_NAME;
1102                 return NULL;
1103         }
1104
1105         DEBUG(5, ("making a connection to 'normal' service %s\n", service));
1106
1107         return make_connection_smb1(sconn, now, snum, vuser,
1108                                     dev, status);
1109 }
1110
1111 /****************************************************************************
1112  Close a cnum.
1113 ****************************************************************************/
1114
1115 void close_cnum(connection_struct *conn, uint64_t vuid)
1116 {
1117         file_close_conn(conn);
1118
1119         if (!IS_IPC(conn)) {
1120                 dptr_closecnum(conn);
1121         }
1122
1123         change_to_root_user();
1124
1125         DEBUG(IS_IPC(conn)?3:1, ("%s (%s) closed connection to service %s\n",
1126                                  get_remote_machine_name(),
1127                                  tsocket_address_string(conn->sconn->remote_address,
1128                                                         talloc_tos()),
1129                                  lp_servicename(talloc_tos(), SNUM(conn))));
1130
1131         /* Call VFS disconnect hook */
1132         SMB_VFS_DISCONNECT(conn);
1133
1134         /* make sure we leave the directory available for unmount */
1135         vfs_ChDir(conn, "/");
1136
1137         /* execute any "postexec = " line */
1138         if (*lp_postexec(talloc_tos(), SNUM(conn)) &&
1139             change_to_user(conn, vuid))  {
1140                 char *cmd = talloc_sub_advanced(talloc_tos(),
1141                                         lp_servicename(talloc_tos(), SNUM(conn)),
1142                                         conn->session_info->unix_info->unix_name,
1143                                         conn->connectpath,
1144                                         conn->session_info->unix_token->gid,
1145                                         conn->session_info->unix_info->sanitized_username,
1146                                         conn->session_info->info->domain_name,
1147                                         lp_postexec(talloc_tos(), SNUM(conn)));
1148                 smbrun(cmd,NULL);
1149                 TALLOC_FREE(cmd);
1150                 change_to_root_user();
1151         }
1152
1153         change_to_root_user();
1154         /* execute any "root postexec = " line */
1155         if (*lp_rootpostexec(talloc_tos(), SNUM(conn)))  {
1156                 char *cmd = talloc_sub_advanced(talloc_tos(),
1157                                         lp_servicename(talloc_tos(), SNUM(conn)),
1158                                         conn->session_info->unix_info->unix_name,
1159                                         conn->connectpath,
1160                                         conn->session_info->unix_token->gid,
1161                                         conn->session_info->unix_info->sanitized_username,
1162                                         conn->session_info->info->domain_name,
1163                                         lp_rootpostexec(talloc_tos(), SNUM(conn)));
1164                 smbrun(cmd,NULL);
1165                 TALLOC_FREE(cmd);
1166         }
1167
1168         conn_free(conn);
1169 }