source3/smbd/vfs.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    VFS initialisation and support functions
   5    Copyright (C) Tim Potter 1999
   6    Copyright (C) Alexander Bokovoy 2002
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22    This work was sponsored by Optifacio Software Services, Inc.
  23 */
  24
  25 #include "includes.h"
  26
  27 #undef DBGC_CLASS
  28 #define DBGC_CLASS DBGC_VFS
  29
  30 struct vfs_init_function_entry {
  31         char *name;
  32         vfs_op_tuple *vfs_op_tuples;
  33         struct vfs_init_function_entry *prev, *next;
  34 };
  35
  36 static struct vfs_init_function_entry *backends = NULL;
  37
  38 /* Some structures to help us initialise the vfs operations table */
  39
  40 struct vfs_syminfo {
  41         char *name;
  42         void *fptr;
  43 };
  44
  45 /* Default vfs hooks.  WARNING: The order of these initialisers is
  46    very important.  They must be in the same order as defined in
  47    vfs.h.  Change at your own peril. */
  48
  49 static struct vfs_ops default_vfs = {
  50
  51         {
  52                 /* Disk operations */
  53
  54                 vfswrap_dummy_connect,
  55                 vfswrap_dummy_disconnect,
  56                 vfswrap_disk_free,
  57                 vfswrap_get_quota,
  58                 vfswrap_set_quota,
  59                 vfswrap_get_shadow_copy_data,
  60
  61                 /* Directory operations */
  62
  63                 vfswrap_opendir,
  64                 vfswrap_readdir,
  65                 vfswrap_mkdir,
  66                 vfswrap_rmdir,
  67                 vfswrap_closedir,
  68
  69                 /* File operations */
  70
  71                 vfswrap_open,
  72                 vfswrap_close,
  73                 vfswrap_read,
  74                 vfswrap_pread,
  75                 vfswrap_write,
  76                 vfswrap_pwrite,
  77                 vfswrap_lseek,
  78                 vfswrap_sendfile,
  79                 vfswrap_rename,
  80                 vfswrap_fsync,
  81                 vfswrap_stat,
  82                 vfswrap_fstat,
  83                 vfswrap_lstat,
  84                 vfswrap_unlink,
  85                 vfswrap_chmod,
  86                 vfswrap_fchmod,
  87                 vfswrap_chown,
  88                 vfswrap_fchown,
  89                 vfswrap_chdir,
  90                 vfswrap_getwd,
  91                 vfswrap_utime,
  92                 vfswrap_ftruncate,
  93                 vfswrap_lock,
  94                 vfswrap_symlink,
  95                 vfswrap_readlink,
  96                 vfswrap_link,
  97                 vfswrap_mknod,
  98                 vfswrap_realpath,
  99
 100                 /* Windows ACL operations. */
 101                 vfswrap_fget_nt_acl,
 102                 vfswrap_get_nt_acl,
 103                 vfswrap_fset_nt_acl,
 104                 vfswrap_set_nt_acl,
 105
 106                 /* POSIX ACL operations. */
 107                 vfswrap_chmod_acl,
 108                 vfswrap_fchmod_acl,
 109
 110                 vfswrap_sys_acl_get_entry,
 111                 vfswrap_sys_acl_get_tag_type,
 112                 vfswrap_sys_acl_get_permset,
 113                 vfswrap_sys_acl_get_qualifier,
 114                 vfswrap_sys_acl_get_file,
 115                 vfswrap_sys_acl_get_fd,
 116                 vfswrap_sys_acl_clear_perms,
 117                 vfswrap_sys_acl_add_perm,
 118                 vfswrap_sys_acl_to_text,
 119                 vfswrap_sys_acl_init,
 120                 vfswrap_sys_acl_create_entry,
 121                 vfswrap_sys_acl_set_tag_type,
 122                 vfswrap_sys_acl_set_qualifier,
 123                 vfswrap_sys_acl_set_permset,
 124                 vfswrap_sys_acl_valid,
 125                 vfswrap_sys_acl_set_file,
 126                 vfswrap_sys_acl_set_fd,
 127                 vfswrap_sys_acl_delete_def_file,
 128                 vfswrap_sys_acl_get_perm,
 129                 vfswrap_sys_acl_free_text,
 130                 vfswrap_sys_acl_free_acl,
 131                 vfswrap_sys_acl_free_qualifier,
 132
 133                 /* EA operations. */
 134                 vfswrap_getxattr,
 135                 vfswrap_lgetxattr,
 136                 vfswrap_fgetxattr,
 137                 vfswrap_listxattr,
 138                 vfswrap_llistxattr,
 139                 vfswrap_flistxattr,
 140                 vfswrap_removexattr,
 141                 vfswrap_lremovexattr,
 142                 vfswrap_fremovexattr,
 143                 vfswrap_setxattr,
 144                 vfswrap_lsetxattr,
 145                 vfswrap_fsetxattr
 146         }
 147 };
 148
 149 /****************************************************************************
 150     maintain the list of available backends
 151 ****************************************************************************/
 152
 153 static struct vfs_init_function_entry *vfs_find_backend_entry(const char *name)
 154 {
 155         struct vfs_init_function_entry *entry = backends;
 156
 157         while(entry) {
 158                 if (strcmp(entry->name, name)==0) return entry;
 159                 entry = entry->next;
 160         }
 161
 162         return NULL;
 163 }
 164
 165 NTSTATUS smb_register_vfs(int version, const char *name, vfs_op_tuple *vfs_op_tuples)
 166 {
 167         struct vfs_init_function_entry *entry = backends;
 168
 169         if ((version != SMB_VFS_INTERFACE_VERSION)) {
 170                 DEBUG(0, ("Failed to register vfs module.\n"
 171                           "The module was compiled against SMB_VFS_INTERFACE_VERSION %d,\n"
 172                           "current SMB_VFS_INTERFACE_VERSION is %d.\n"
 173                           "Please recompile against the current Samba Version!\n",
 174                           version, SMB_VFS_INTERFACE_VERSION));
 175                 return NT_STATUS_OBJECT_TYPE_MISMATCH;
 176         }
 177
 178         if (!name || !name[0] || !vfs_op_tuples) {
 179                 DEBUG(0,("smb_register_vfs() called with NULL pointer or empty name!\n"));
 180                 return NT_STATUS_INVALID_PARAMETER;
 181         }
 182
 183         if (vfs_find_backend_entry(name)) {
 184                 DEBUG(0,("VFS module %s already loaded!\n", name));
 185                 return NT_STATUS_OBJECT_NAME_COLLISION;
 186         }
 187
 188         entry = smb_xmalloc(sizeof(struct vfs_init_function_entry));
 189         entry->name = smb_xstrdup(name);
 190         entry->vfs_op_tuples = vfs_op_tuples;
 191
 192         DLIST_ADD(backends, entry);
 193         DEBUG(5, ("Successfully added vfs backend '%s'\n", name));
 194         return NT_STATUS_OK;
 195 }
 196
 197 /****************************************************************************
 198   initialise default vfs hooks
 199 ****************************************************************************/
 200
 201 static void vfs_init_default(connection_struct *conn)
 202 {
 203         DEBUG(3, ("Initialising default vfs hooks\n"));
 204
 205         memcpy(&conn->vfs.ops, &default_vfs.ops, sizeof(default_vfs.ops));
 206         memcpy(&conn->vfs_opaque.ops, &default_vfs.ops, sizeof(default_vfs.ops));
 207 }
 208
 209 /****************************************************************************
 210   initialise custom vfs hooks
 211  ****************************************************************************/
 212
 213 BOOL vfs_init_custom(connection_struct *conn, const char *vfs_object)
 214 {
 215         vfs_op_tuple *ops;
 216         char *module_name = NULL;
 217         char *module_param = NULL, *p;
 218         int i;
 219         vfs_handle_struct *handle;
 220         struct vfs_init_function_entry *entry;
 221
 222         if (!conn||!vfs_object||!vfs_object[0]) {
 223                 DEBUG(0,("vfs_init_custon() called with NULL pointer or emtpy vfs_object!\n"));
 224                 return False;
 225         }
 226
 227         if(!backends) static_init_vfs;
 228
 229         DEBUG(3, ("Initialising custom vfs hooks from [%s]\n", vfs_object));
 230
 231         module_name = smb_xstrdup(vfs_object);
 232
 233         p = strchr(module_name, ':');
 234
 235         if (p) {
 236                 *p = 0;
 237                 module_param = p+1;
 238                 trim_char(module_param, ' ', ' ');
 239         }
 240
 241         trim_char(module_name, ' ', ' ');
 242
 243         /* First, try to load the module with the new module system */
 244         if((entry = vfs_find_backend_entry(module_name)) ||
 245            (NT_STATUS_IS_OK(smb_probe_module("vfs", module_name)) &&
 246                 (entry = vfs_find_backend_entry(module_name)))) {
 247
 248                 DEBUGADD(5,("Successfully loaded vfs module [%s] with the new modules system\n", vfs_object));
 249
 250                 if ((ops = entry->vfs_op_tuples) == NULL) {
 251                         DEBUG(0, ("entry->vfs_op_tuples==NULL for [%s] failed\n", vfs_object));
 252                         SAFE_FREE(module_name);
 253                         return False;
 254                 }
 255         } else {
 256                 DEBUG(0,("Can't find a vfs module [%s]\n",vfs_object));
 257                 SAFE_FREE(module_name);
 258                 return False;
 259         }
 260
 261         handle = (vfs_handle_struct *)talloc_zero(conn->mem_ctx,sizeof(vfs_handle_struct));
 262         if (!handle) {
 263                 DEBUG(0,("talloc_zero() failed!\n"));
 264                 SAFE_FREE(module_name);
 265                 return False;
 266         }
 267         memcpy(&handle->vfs_next, &conn->vfs, sizeof(struct vfs_ops));
 268         handle->conn = conn;
 269         if (module_param) {
 270                 handle->param = talloc_strdup(conn->mem_ctx, module_param);
 271         }
 272         DLIST_ADD(conn->vfs_handles, handle);
 273
 274         for(i=0; ops[i].op != NULL; i++) {
 275           DEBUG(5, ("Checking operation #%d (type %d, layer %d)\n", i, ops[i].type, ops[i].layer));
 276           if(ops[i].layer == SMB_VFS_LAYER_OPAQUE) {
 277             /* Check whether this operation was already made opaque by different module */
 278             if(((void**)&conn->vfs_opaque.ops)[ops[i].type] == ((void**)&default_vfs.ops)[ops[i].type]) {
 279               /* No, it isn't overloaded yet. Overload. */
 280               DEBUGADD(5, ("Making operation type %d opaque [module %s]\n", ops[i].type, vfs_object));
 281               ((void**)&conn->vfs_opaque.ops)[ops[i].type] = ops[i].op;
 282               ((vfs_handle_struct **)&conn->vfs_opaque.handles)[ops[i].type] = handle;
 283             }
 284           }
 285           /* Change current VFS disposition*/
 286           DEBUGADD(5, ("Accepting operation type %d from module %s\n", ops[i].type, vfs_object));
 287           ((void**)&conn->vfs.ops)[ops[i].type] = ops[i].op;
 288           ((vfs_handle_struct **)&conn->vfs.handles)[ops[i].type] = handle;
 289         }
 290
 291         SAFE_FREE(module_name);
 292         return True;
 293 }
 294
 295 /*****************************************************************
 296  Generic VFS init.
 297 ******************************************************************/
 298
 299 BOOL smbd_vfs_init(connection_struct *conn)
 300 {
 301         const char **vfs_objects;
 302         unsigned int i = 0;
 303         int j = 0;
 304
 305         /* Normal share - initialise with disk access functions */
 306         vfs_init_default(conn);
 307         vfs_objects = lp_vfs_objects(SNUM(conn));
 308
 309         /* Override VFS functions if 'vfs object' was not specified*/
 310         if (!vfs_objects || !vfs_objects[0])
 311                 return True;
 312
 313         for (i=0; vfs_objects[i] ;) {
 314                 i++;
 315         }
 316
 317         for (j=i-1; j >= 0; j--) {
 318                 if (!vfs_init_custom(conn, vfs_objects[j])) {
 319                         DEBUG(0, ("smbd_vfs_init: vfs_init_custom failed for %s\n", vfs_objects[j]));
 320                         return False;
 321                 }
 322         }
 323         return True;
 324 }
 325
 326 /*******************************************************************
 327  Check if directory exists.
 328 ********************************************************************/
 329
 330 BOOL vfs_directory_exist(connection_struct *conn, const char *dname, SMB_STRUCT_STAT *st)
 331 {
 332         SMB_STRUCT_STAT st2;
 333         BOOL ret;
 334
 335         if (!st)
 336                 st = &st2;
 337
 338         if (SMB_VFS_STAT(conn,dname,st) != 0)
 339                 return(False);
 340
 341         ret = S_ISDIR(st->st_mode);
 342         if(!ret)
 343                 errno = ENOTDIR;
 344
 345         return ret;
 346 }
 347
 348 /*******************************************************************
 349  vfs mkdir wrapper
 350 ********************************************************************/
 351
 352 int vfs_MkDir(connection_struct *conn, const char *name, mode_t mode)
 353 {
 354         int ret;
 355         SMB_STRUCT_STAT sbuf;
 356
 357         if(!(ret=SMB_VFS_MKDIR(conn, name, mode))) {
 358
 359                 inherit_access_acl(conn, name, mode);
 360
 361                 /*
 362                  * Check if high bits should have been set,
 363                  * then (if bits are missing): add them.
 364                  * Consider bits automagically set by UNIX, i.e. SGID bit from parent dir.
 365                  */
 366                 if(mode & ~(S_IRWXU|S_IRWXG|S_IRWXO) &&
 367                                 !SMB_VFS_STAT(conn,name,&sbuf) && (mode & ~sbuf.st_mode))
 368                         SMB_VFS_CHMOD(conn,name,sbuf.st_mode | (mode & ~sbuf.st_mode));
 369         }
 370         return ret;
 371 }
 372
 373 /*******************************************************************
 374  Check if an object exists in the vfs.
 375 ********************************************************************/
 376
 377 BOOL vfs_object_exist(connection_struct *conn,const char *fname,SMB_STRUCT_STAT *sbuf)
 378 {
 379         SMB_STRUCT_STAT st;
 380
 381         if (!sbuf)
 382                 sbuf = &st;
 383
 384         ZERO_STRUCTP(sbuf);
 385
 386         if (SMB_VFS_STAT(conn,fname,sbuf) == -1)
 387                 return(False);
 388         return True;
 389 }
 390
 391 /*******************************************************************
 392  Check if a file exists in the vfs.
 393 ********************************************************************/
 394
 395 BOOL vfs_file_exist(connection_struct *conn, const char *fname,SMB_STRUCT_STAT *sbuf)
 396 {
 397         SMB_STRUCT_STAT st;
 398
 399         if (!sbuf)
 400                 sbuf = &st;
 401
 402         ZERO_STRUCTP(sbuf);
 403
 404         if (SMB_VFS_STAT(conn,fname,sbuf) == -1)
 405                 return False;
 406         return(S_ISREG(sbuf->st_mode));
 407 }
 408
 409 /****************************************************************************
 410  Read data from fsp on the vfs. (note: EINTR re-read differs from vfs_write_data)
 411 ****************************************************************************/
 412
 413 ssize_t vfs_read_data(files_struct *fsp, char *buf, size_t byte_count)
 414 {
 415         size_t total=0;
 416
 417         while (total < byte_count)
 418         {
 419                 ssize_t ret = SMB_VFS_READ(fsp, fsp->fd, buf + total,
 420                                         byte_count - total);
 421
 422                 if (ret == 0) return total;
 423                 if (ret == -1) {
 424                         if (errno == EINTR)
 425                                 continue;
 426                         else
 427                                 return -1;
 428                 }
 429                 total += ret;
 430         }
 431         return (ssize_t)total;
 432 }
 433
 434 ssize_t vfs_pread_data(files_struct *fsp, char *buf,
 435                 size_t byte_count, SMB_OFF_T offset)
 436 {
 437         size_t total=0;
 438
 439         while (total < byte_count)
 440         {
 441                 ssize_t ret = SMB_VFS_PREAD(fsp, fsp->fd, buf + total,
 442                                         byte_count - total, offset + total);
 443
 444                 if (ret == 0) return total;
 445                 if (ret == -1) {
 446                         if (errno == EINTR)
 447                                 continue;
 448                         else
 449                                 return -1;
 450                 }
 451                 total += ret;
 452         }
 453         return (ssize_t)total;
 454 }
 455
 456 /****************************************************************************
 457  Write data to a fd on the vfs.
 458 ****************************************************************************/
 459
 460 ssize_t vfs_write_data(files_struct *fsp,const char *buffer,size_t N)
 461 {
 462         size_t total=0;
 463         ssize_t ret;
 464
 465         while (total < N) {
 466                 ret = SMB_VFS_WRITE(fsp,fsp->fd,buffer + total,N - total);
 467
 468                 if (ret == -1)
 469                         return -1;
 470                 if (ret == 0)
 471                         return total;
 472
 473                 total += ret;
 474         }
 475         return (ssize_t)total;
 476 }
 477
 478 ssize_t vfs_pwrite_data(files_struct *fsp,const char *buffer,
 479                 size_t N, SMB_OFF_T offset)
 480 {
 481         size_t total=0;
 482         ssize_t ret;
 483
 484         while (total < N) {
 485                 ret = SMB_VFS_PWRITE(fsp, fsp->fd, buffer + total,
 486                                 N - total, offset + total);
 487
 488                 if (ret == -1)
 489                         return -1;
 490                 if (ret == 0)
 491                         return total;
 492
 493                 total += ret;
 494         }
 495         return (ssize_t)total;
 496 }
 497 /****************************************************************************
 498  An allocate file space call using the vfs interface.
 499  Allocates space for a file from a filedescriptor.
 500  Returns 0 on success, -1 on failure.
 501 ****************************************************************************/
 502
 503 int vfs_allocate_file_space(files_struct *fsp, SMB_BIG_UINT len)
 504 {
 505         int ret;
 506         SMB_STRUCT_STAT st;
 507         connection_struct *conn = fsp->conn;
 508         SMB_BIG_UINT space_avail;
 509         SMB_BIG_UINT bsize,dfree,dsize;
 510
 511         release_level_2_oplocks_on_change(fsp);
 512
 513         /*
 514          * Actually try and commit the space on disk....
 515          */
 516
 517         DEBUG(10,("vfs_allocate_file_space: file %s, len %.0f\n", fsp->fsp_name, (double)len ));
 518
 519         if (((SMB_OFF_T)len) < 0) {
 520                 DEBUG(0,("vfs_allocate_file_space: %s negative len requested.\n", fsp->fsp_name ));
 521                 return -1;
 522         }
 523
 524         ret = SMB_VFS_FSTAT(fsp,fsp->fd,&st);
 525         if (ret == -1)
 526                 return ret;
 527
 528         if (len == (SMB_BIG_UINT)st.st_size)
 529                 return 0;
 530
 531         if (len < (SMB_BIG_UINT)st.st_size) {
 532                 /* Shrink - use ftruncate. */
 533
 534                 DEBUG(10,("vfs_allocate_file_space: file %s, shrink. Current size %.0f\n",
 535                                 fsp->fsp_name, (double)st.st_size ));
 536
 537                 flush_write_cache(fsp, SIZECHANGE_FLUSH);
 538                 if ((ret = SMB_VFS_FTRUNCATE(fsp, fsp->fd, (SMB_OFF_T)len)) != -1) {
 539                         set_filelen_write_cache(fsp, len);
 540                 }
 541                 return ret;
 542         }
 543
 544         /* Grow - we need to test if we have enough space. */
 545
 546         if (!lp_strict_allocate(SNUM(fsp->conn)))
 547                 return 0;
 548
 549         len -= st.st_size;
 550         len /= 1024; /* Len is now number of 1k blocks needed. */
 551         space_avail = SMB_VFS_DISK_FREE(conn,fsp->fsp_name,False,&bsize,&dfree,&dsize);
 552
 553         DEBUG(10,("vfs_allocate_file_space: file %s, grow. Current size %.0f, needed blocks = %.0f, space avail = %.0f\n",
 554                         fsp->fsp_name, (double)st.st_size, (double)len, (double)space_avail ));
 555
 556         if (len > space_avail) {
 557                 errno = ENOSPC;
 558                 return -1;
 559         }
 560
 561         return 0;
 562 }
 563
 564 /****************************************************************************
 565  A vfs set_filelen call.
 566  set the length of a file from a filedescriptor.
 567  Returns 0 on success, -1 on failure.
 568 ****************************************************************************/
 569
 570 int vfs_set_filelen(files_struct *fsp, SMB_OFF_T len)
 571 {
 572         int ret;
 573
 574         release_level_2_oplocks_on_change(fsp);
 575         DEBUG(10,("vfs_set_filelen: ftruncate %s to len %.0f\n", fsp->fsp_name, (double)len));
 576         flush_write_cache(fsp, SIZECHANGE_FLUSH);
 577         if ((ret = SMB_VFS_FTRUNCATE(fsp, fsp->fd, len)) != -1)
 578                 set_filelen_write_cache(fsp, len);
 579
 580         return ret;
 581 }
 582
 583 /****************************************************************************
 584  Transfer some data (n bytes) between two file_struct's.
 585 ****************************************************************************/
 586
 587 static files_struct *in_fsp;
 588 static files_struct *out_fsp;
 589
 590 static ssize_t read_fn(int fd, void *buf, size_t len)
 591 {
 592         return SMB_VFS_READ(in_fsp, fd, buf, len);
 593 }
 594
 595 static ssize_t write_fn(int fd, const void *buf, size_t len)
 596 {
 597         return SMB_VFS_WRITE(out_fsp, fd, buf, len);
 598 }
 599
 600 SMB_OFF_T vfs_transfer_file(files_struct *in, files_struct *out, SMB_OFF_T n)
 601 {
 602         in_fsp = in;
 603         out_fsp = out;
 604
 605         return transfer_file_internal(in_fsp->fd, out_fsp->fd, n, read_fn, write_fn);
 606 }
 607
 608 /*******************************************************************
 609  A vfs_readdir wrapper which just returns the file name.
 610 ********************************************************************/
 611
 612 char *vfs_readdirname(connection_struct *conn, void *p)
 613 {
 614         struct dirent *ptr= NULL;
 615         char *dname;
 616
 617         if (!p)
 618                 return(NULL);
 619
 620         ptr = (struct dirent *)SMB_VFS_READDIR(conn,p);
 621         if (!ptr)
 622                 return(NULL);
 623
 624         dname = ptr->d_name;
 625
 626 #ifdef NEXT2
 627         if (telldir(p) < 0)
 628                 return(NULL);
 629 #endif
 630
 631 #ifdef HAVE_BROKEN_READDIR
 632         /* using /usr/ucb/cc is BAD */
 633         dname = dname - 2;
 634 #endif
 635
 636         return(dname);
 637 }
 638
 639 /*******************************************************************
 640  A wrapper for vfs_chdir().
 641 ********************************************************************/
 642
 643 int vfs_ChDir(connection_struct *conn, const char *path)
 644 {
 645         int res;
 646         static pstring LastDir="";
 647
 648         if (strcsequal(path,"."))
 649                 return(0);
 650
 651         if (*path == '/' && strcsequal(LastDir,path))
 652                 return(0);
 653
 654         DEBUG(4,("vfs_ChDir to %s\n",path));
 655
 656         res = SMB_VFS_CHDIR(conn,path);
 657         if (!res)
 658                 pstrcpy(LastDir,path);
 659         return(res);
 660 }
 661
 662 /* number of list structures for a caching GetWd function. */
 663 #define MAX_GETWDCACHE (50)
 664
 665 static struct {
 666         SMB_DEV_T dev; /* These *must* be compatible with the types returned in a stat() call. */
 667         SMB_INO_T inode; /* These *must* be compatible with the types returned in a stat() call. */
 668         char *dos_path; /* The pathname in DOS format. */
 669         BOOL valid;
 670 } ino_list[MAX_GETWDCACHE];
 671
 672 extern BOOL use_getwd_cache;
 673
 674 /****************************************************************************
 675  Prompte a ptr (to make it recently used)
 676 ****************************************************************************/
 677
 678 static void array_promote(char *array,int elsize,int element)
 679 {
 680         char *p;
 681         if (element == 0)
 682                 return;
 683
 684         p = (char *)malloc(elsize);
 685
 686         if (!p) {
 687                 DEBUG(5,("array_promote: malloc fail\n"));
 688                 return;
 689         }
 690
 691         memcpy(p,array + element * elsize, elsize);
 692         memmove(array + elsize,array,elsize*element);
 693         memcpy(array,p,elsize);
 694         SAFE_FREE(p);
 695 }
 696
 697 /*******************************************************************
 698  Return the absolute current directory path - given a UNIX pathname.
 699  Note that this path is returned in DOS format, not UNIX
 700  format. Note this can be called with conn == NULL.
 701 ********************************************************************/
 702
 703 char *vfs_GetWd(connection_struct *conn, char *path)
 704 {
 705         pstring s;
 706         static BOOL getwd_cache_init = False;
 707         SMB_STRUCT_STAT st, st2;
 708         int i;
 709
 710         *s = 0;
 711
 712         if (!use_getwd_cache)
 713                 return(SMB_VFS_GETWD(conn,path));
 714
 715         /* init the cache */
 716         if (!getwd_cache_init) {
 717                 getwd_cache_init = True;
 718                 for (i=0;i<MAX_GETWDCACHE;i++) {
 719                         string_set(&ino_list[i].dos_path,"");
 720                         ino_list[i].valid = False;
 721                 }
 722         }
 723
 724         /*  Get the inode of the current directory, if this doesn't work we're
 725                 in trouble :-) */
 726
 727         if (SMB_VFS_STAT(conn, ".",&st) == -1) {
 728                 DEBUG(0,("Very strange, couldn't stat \".\" path=%s\n", path));
 729                 return(SMB_VFS_GETWD(conn,path));
 730         }
 731
 732
 733         for (i=0; i<MAX_GETWDCACHE; i++) {
 734                 if (ino_list[i].valid) {
 735
 736                         /*  If we have found an entry with a matching inode and dev number
 737                                 then find the inode number for the directory in the cached string.
 738                                 If this agrees with that returned by the stat for the current
 739                                 directory then all is o.k. (but make sure it is a directory all
 740                                 the same...) */
 741
 742                         if (st.st_ino == ino_list[i].inode && st.st_dev == ino_list[i].dev) {
 743                                 if (SMB_VFS_STAT(conn,ino_list[i].dos_path,&st2) == 0) {
 744                                         if (st.st_ino == st2.st_ino && st.st_dev == st2.st_dev &&
 745                                                         (st2.st_mode & S_IFMT) == S_IFDIR) {
 746                                                 pstrcpy (path, ino_list[i].dos_path);
 747
 748                                                 /* promote it for future use */
 749                                                 array_promote((char *)&ino_list[0],sizeof(ino_list[0]),i);
 750                                                 return (path);
 751                                         } else {
 752                                                 /*  If the inode is different then something's changed,
 753                                                         scrub the entry and start from scratch. */
 754                                                 ino_list[i].valid = False;
 755                                         }
 756                                 }
 757                         }
 758                 }
 759         }
 760
 761         /*  We don't have the information to hand so rely on traditional methods.
 762                 The very slow getcwd, which spawns a process on some systems, or the
 763                 not quite so bad getwd. */
 764
 765         if (!SMB_VFS_GETWD(conn,s)) {
 766                 DEBUG(0,("vfs_GetWd: SMB_VFS_GETWD call failed, errno %s\n",strerror(errno)));
 767                 return (NULL);
 768         }
 769
 770         pstrcpy(path,s);
 771
 772         DEBUG(5,("vfs_GetWd %s, inode %.0f, dev %.0f\n",s,(double)st.st_ino,(double)st.st_dev));
 773
 774         /* add it to the cache */
 775         i = MAX_GETWDCACHE - 1;
 776         string_set(&ino_list[i].dos_path,s);
 777         ino_list[i].dev = st.st_dev;
 778         ino_list[i].inode = st.st_ino;
 779         ino_list[i].valid = True;
 780
 781         /* put it at the top of the list */
 782         array_promote((char *)&ino_list[0],sizeof(ino_list[0]),i);
 783
 784         return (path);
 785 }
 786
 787
 788 /* check if the file 'nmae' is a symlink, in that case check that it point to
 789    a file that reside under the 'dir' tree */
 790
 791 static BOOL readlink_check(connection_struct *conn, const char *dir, char *name)
 792 {
 793         BOOL ret = True;
 794         pstring flink;
 795         pstring cleanlink;
 796         pstring savedir;
 797         pstring realdir;
 798         size_t reallen;
 799
 800         if (!vfs_GetWd(conn, savedir)) {
 801                 DEBUG(0,("couldn't vfs_GetWd for %s %s\n", name, dir));
 802                 return False;
 803         }
 804
 805         if (vfs_ChDir(conn, dir) != 0) {
 806                 DEBUG(0,("couldn't vfs_ChDir to %s\n", dir));
 807                 return False;
 808         }
 809
 810         if (!vfs_GetWd(conn, realdir)) {
 811                 DEBUG(0,("couldn't vfs_GetWd for %s\n", dir));
 812                 vfs_ChDir(conn, savedir);
 813                 return(False);
 814         }
 815
 816         reallen = strlen(realdir);
 817         if (realdir[reallen -1] == '/') {
 818                 reallen--;
 819                 realdir[reallen] = 0;
 820         }
 821
 822         if (SMB_VFS_READLINK(conn, name, flink, sizeof(pstring) -1) != -1) {
 823                 DEBUG(3,("reduce_name: file path name %s is a symlink\nChecking it's path\n", name));
 824                 if (*flink == '/') {
 825                         pstrcpy(cleanlink, flink);
 826                 } else {
 827                         pstrcpy(cleanlink, realdir);
 828                         pstrcat(cleanlink, "/");
 829                         pstrcat(cleanlink, flink);
 830                 }
 831                 unix_clean_name(cleanlink);
 832
 833                 if (strncmp(cleanlink, realdir, reallen) != 0) {
 834                         DEBUG(2,("Bad access attempt? s=%s dir=%s newname=%s l=%d\n", name, realdir, cleanlink, (int)reallen));
 835                         ret = False;
 836                 }
 837         }
 838
 839         vfs_ChDir(conn, savedir);
 840
 841         return ret;
 842 }
 843
 844 /*******************************************************************
 845  Reduce a file name, removing .. elements and checking that
 846  it is below dir in the heirachy. This uses vfs_GetWd() and so must be run
 847  on the system that has the referenced file system.
 848 ********************************************************************/
 849
 850 BOOL reduce_name(connection_struct *conn, pstring s, const char *dir)
 851 {
 852 #ifndef REDUCE_PATHS
 853         return True;
 854 #else
 855         pstring dir2;
 856         pstring wd;
 857         pstring base_name;
 858         pstring newname;
 859         char *p=NULL;
 860         BOOL relative = (*s != '/');
 861
 862         *dir2 = *wd = *base_name = *newname = 0;
 863
 864         DEBUG(3,("reduce_name [%s] [%s]\n",s,dir));
 865
 866         /* We know there are no double slashes as this comes from srvstr_get_path().
 867            and has gone through check_path_syntax(). JRA */
 868
 869         pstrcpy(base_name,s);
 870         p = strrchr_m(base_name,'/');
 871
 872         if (!p)
 873                 return readlink_check(conn, dir, s);
 874
 875         if (!vfs_GetWd(conn,wd)) {
 876                 DEBUG(0,("couldn't vfs_GetWd for %s %s\n",s,dir));
 877                 return(False);
 878         }
 879
 880         if (vfs_ChDir(conn,dir) != 0) {
 881                 DEBUG(0,("couldn't vfs_ChDir to %s\n",dir));
 882                 return(False);
 883         }
 884
 885         if (!vfs_GetWd(conn,dir2)) {
 886                 DEBUG(0,("couldn't vfs_GetWd for %s\n",dir));
 887                 vfs_ChDir(conn,wd);
 888                 return(False);
 889         }
 890
 891         if (p && (p != base_name)) {
 892                 *p = 0;
 893                 if (strcmp(p+1,".")==0)
 894                         p[1]=0;
 895                 if (strcmp(p+1,"..")==0)
 896                         *p = '/';
 897         }
 898
 899         if (vfs_ChDir(conn,base_name) != 0) {
 900                 vfs_ChDir(conn,wd);
 901                 DEBUG(3,("couldn't vfs_ChDir for %s %s basename=%s\n",s,dir,base_name));
 902                 return(False);
 903         }
 904
 905         if (!vfs_GetWd(conn,newname)) {
 906                 vfs_ChDir(conn,wd);
 907                 DEBUG(2,("couldn't get vfs_GetWd for %s %s\n",s,base_name));
 908                 return(False);
 909         }
 910
 911         if (p && (p != base_name)) {
 912                 pstrcat(newname,"/");
 913                 pstrcat(newname,p+1);
 914         }
 915
 916         {
 917                 size_t l = strlen(dir2);
 918                 char *last_slash = strrchr_m(dir2, '/');
 919
 920                 if (last_slash && (last_slash[1] == '\0'))
 921                         l--;
 922
 923                 if (strncmp(newname,dir2,l) != 0) {
 924                         vfs_ChDir(conn,wd);
 925                         DEBUG(2,("Bad access attempt: s=%s dir=%s newname=%s l=%d\n",s,dir2,newname,(int)l));
 926                         return(False);
 927                 }
 928
 929                 if (!readlink_check(conn, dir, newname)) {
 930                         DEBUG(2, ("Bad access attemt: %s is a symlink outside the share path", s));
 931                         return(False);
 932                 }
 933
 934                 if (relative) {
 935                         if (newname[l] == '/')
 936                                 pstrcpy(s,newname + l + 1);
 937                         else
 938                                 pstrcpy(s,newname+l);
 939                 } else
 940                         pstrcpy(s,newname);
 941         }
 942
 943         vfs_ChDir(conn,wd);
 944
 945         if (strlen(s) == 0)
 946                 pstrcpy(s,"./");
 947
 948         DEBUG(3,("reduced to %s\n",s));
 949         return(True);
 950 #endif
 951 }