source/smbd/filename.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    filename handling routines
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 1999-200
   6    Copyright (C) Ying Chen 2000
   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
  23 /*
  24  * New hash table stat cache code added by Ying Chen.
  25  */
  26
  27 #include "includes.h"
  28
  29 extern BOOL case_sensitive;
  30 extern BOOL case_preserve;
  31 extern BOOL short_case_preserve;
  32 extern BOOL use_mangled_map;
  33
  34 static BOOL scan_directory(const char *path, char *name,size_t maxlength,
  35                            connection_struct *conn,BOOL docache);
  36
  37 /****************************************************************************
  38  Check if two filenames are equal.
  39  This needs to be careful about whether we are case sensitive.
  40 ****************************************************************************/
  41
  42 static BOOL fname_equal(char *name1, char *name2)
  43 {
  44         /* Normal filename handling */
  45         if (case_sensitive)
  46                 return(strcmp(name1,name2) == 0);
  47
  48         return(strequal(name1,name2));
  49 }
  50
  51 /****************************************************************************
  52  Mangle the 2nd name and check if it is then equal to the first name.
  53 ****************************************************************************/
  54
  55 static BOOL mangled_equal(char *name1, const char *name2, int snum)
  56 {
  57         pstring tmpname;
  58
  59         pstrcpy(tmpname, name2);
  60         mangle_map(tmpname, True, False, snum);
  61         return strequal(name1, tmpname);
  62 }
  63
  64 /****************************************************************************
  65 This routine is called to convert names from the dos namespace to unix
  66 namespace. It needs to handle any case conversions, mangling, format
  67 changes etc.
  68
  69 We assume that we have already done a chdir() to the right "root" directory
  70 for this service.
  71
  72 The function will return False if some part of the name except for the last
  73 part cannot be resolved
  74
  75 If the saved_last_component != 0, then the unmodified last component
  76 of the pathname is returned there. This is used in an exceptional
  77 case in reply_mv (so far). If saved_last_component == 0 then nothing
  78 is returned there.
  79
  80 The bad_path arg is set to True if the filename walk failed. This is
  81 used to pick the correct error code to return between ENOENT and ENOTDIR
  82 as Windows applications depend on ERRbadpath being returned if a component
  83 of a pathname does not exist.
  84
  85 On exit from unix_convert, if *pst was not null, then the file stat
  86 struct will be returned if the file exists and was found, if not this
  87 stat struct will be filled with zeros (and this can be detected by checking
  88 for nlinks = 0, which can never be true for any file).
  89 ****************************************************************************/
  90
  91 BOOL unix_convert(pstring name,connection_struct *conn,char *saved_last_component,
  92                   BOOL *bad_path, SMB_STRUCT_STAT *pst)
  93 {
  94         SMB_STRUCT_STAT st;
  95         char *start, *end;
  96         pstring dirpath;
  97         pstring orig_path;
  98         BOOL component_was_mangled = False;
  99         BOOL name_has_wildcard = False;
 100
 101         ZERO_STRUCTP(pst);
 102
 103         *dirpath = 0;
 104         *bad_path = False;
 105         if(saved_last_component)
 106                 *saved_last_component = 0;
 107
 108         if (conn->printer) {
 109                 /* we don't ever use the filenames on a printer share as a
 110                         filename - so don't convert them */
 111                 return True;
 112         }
 113
 114         DEBUG(5, ("unix_convert called on file \"%s\"\n", name));
 115
 116         /*
 117          * Convert to basic unix format - removing \ chars and cleaning it up.
 118          */
 119
 120         unix_format(name);
 121         unix_clean_name(name);
 122
 123         /*
 124          * Names must be relative to the root of the service - trim any leading /.
 125          * also trim trailing /'s.
 126          */
 127
 128         trim_string(name,"/","/");
 129
 130         /*
 131          * If we trimmed down to a single '\0' character
 132          * then we should use the "." directory to avoid
 133          * searching the cache, but not if we are in a
 134          * printing share.
 135          */
 136
 137         if (!*name) {
 138                 name[0] = '.';
 139                 name[1] = '\0';
 140         }
 141
 142         /*
 143          * Ensure saved_last_component is valid even if file exists.
 144          */
 145
 146         if(saved_last_component) {
 147                 end = strrchr_m(name, '/');
 148                 if(end)
 149                         pstrcpy(saved_last_component, end + 1);
 150                 else
 151                         pstrcpy(saved_last_component, name);
 152         }
 153
 154         if (!case_sensitive && (!case_preserve || (mangle_is_8_3(name, False) && !short_case_preserve)))
 155                 strnorm(name);
 156
 157         /*
 158          * If we trimmed down to a single '\0' character
 159          * then we will be using the "." directory.
 160          * As we know this is valid we can return true here.
 161          */
 162
 163         if(!*name)
 164                 return(True);
 165
 166         start = name;
 167         while (strncmp(start,"./",2) == 0)
 168                 start += 2;
 169
 170         pstrcpy(orig_path, name);
 171
 172         if(!case_sensitive && stat_cache_lookup(conn, name, dirpath, &start, &st)) {
 173                 *pst = st;
 174                 return True;
 175         }
 176
 177         /*
 178          * stat the name - if it exists then we are all done!
 179          */
 180
 181         if (vfs_stat(conn,name,&st) == 0) {
 182                 stat_cache_add(orig_path, name);
 183                 DEBUG(5,("conversion finished %s -> %s\n",orig_path, name));
 184                 *pst = st;
 185                 return(True);
 186         }
 187
 188         DEBUG(5,("unix_convert begin: name = %s, dirpath = %s, start = %s\n", name, dirpath, start));
 189
 190         /*
 191          * A special case - if we don't have any mangling chars and are case
 192          * sensitive then searching won't help.
 193          */
 194
 195         if (case_sensitive && !mangle_is_mangled(name) && !use_mangled_map)
 196                 return(False);
 197
 198         name_has_wildcard = ms_has_wild(start);
 199
 200         /*
 201          * is_mangled() was changed to look at an entire pathname, not
 202          * just a component. JRA.
 203          */
 204
 205         if (mangle_is_mangled(start))
 206                 component_was_mangled = True;
 207
 208         /*
 209          * Now we need to recursively match the name against the real
 210          * directory structure.
 211          */
 212
 213         /*
 214          * Match each part of the path name separately, trying the names
 215          * as is first, then trying to scan the directory for matching names.
 216          */
 217
 218         for (; start ; start = (end?end+1:(char *)NULL)) {
 219                 /*
 220                  * Pinpoint the end of this section of the filename.
 221                  */
 222                 end = strchr_m(start, '/');
 223
 224                 /*
 225                  * Chop the name at this point.
 226                  */
 227                 if (end)
 228                         *end = 0;
 229
 230                 if(saved_last_component != 0)
 231                         pstrcpy(saved_last_component, end ? end + 1 : start);
 232
 233                 /*
 234                  * Check if the name exists up to this point.
 235                  */
 236
 237                 if (vfs_stat(conn,name, &st) == 0) {
 238                         /*
 239                          * It exists. it must either be a directory or this must be
 240                          * the last part of the path for it to be OK.
 241                          */
 242                         if (end && !(st.st_mode & S_IFDIR)) {
 243                                 /*
 244                                  * An intermediate part of the name isn't a directory.
 245                                  */
 246                                 DEBUG(5,("Not a dir %s\n",start));
 247                                 *end = '/';
 248                                 return(False);
 249                         }
 250
 251                 } else {
 252                         pstring rest;
 253
 254                         /* Stat failed - ensure we don't use it. */
 255                         ZERO_STRUCT(st);
 256                         *rest = 0;
 257
 258                         /*
 259                          * Remember the rest of the pathname so it can be restored
 260                          * later.
 261                          */
 262
 263                         if (end)
 264                                 pstrcpy(rest,end+1);
 265
 266                         /*
 267                          * Try to find this part of the path in the directory.
 268                          */
 269
 270                         if (ms_has_wild(start) ||
 271                             !scan_directory(dirpath, start,
 272                                             sizeof(pstring) - 1 - (start - name),
 273                                             conn,
 274                                             end?True:False)) {
 275                                 if (end) {
 276                                         /*
 277                                          * An intermediate part of the name can't be found.
 278                                          */
 279                                         DEBUG(5,("Intermediate not found %s\n",start));
 280                                         *end = '/';
 281
 282                                         /*
 283                                          * We need to return the fact that the intermediate
 284                                          * name resolution failed. This is used to return an
 285                                          * error of ERRbadpath rather than ERRbadfile. Some
 286                                          * Windows applications depend on the difference between
 287                                          * these two errors.
 288                                          */
 289                                         *bad_path = True;
 290                                         return(False);
 291                                 }
 292
 293                                 /*
 294                                  * Just the last part of the name doesn't exist.
 295                                  * We may need to strupper() or strlower() it in case
 296                                  * this conversion is being used for file creation
 297                                  * purposes. If the filename is of mixed case then
 298                                  * don't normalise it.
 299                                  */
 300
 301                                 if (!case_preserve && (!strhasupper(start) || !strhaslower(start)))
 302                                         strnorm(start);
 303
 304                                 /*
 305                                  * check on the mangled stack to see if we can recover the
 306                                  * base of the filename.
 307                                  */
 308
 309                                 if (mangle_is_mangled(start)) {
 310                                         mangle_check_cache( start );
 311                                 }
 312
 313                                 DEBUG(5,("New file %s\n",start));
 314                                 return(True);
 315                         }
 316
 317                         /*
 318                          * Restore the rest of the string. If the string was mangled the size
 319                          * may have changed.
 320                          */
 321                         if (end) {
 322                                 end = start + strlen(start);
 323                                 if (!safe_strcat(start, "/", sizeof(pstring) - 1 - (start - name)) ||
 324                                     !safe_strcat(start, rest, sizeof(pstring) - 1 - (start - name))) {
 325                                         return False;
 326                                 }
 327                                 *end = '\0';
 328                         } else {
 329                                 /*
 330                                  * We just scanned for, and found the end of the path.
 331                                  * We must return a valid stat struct if it exists.
 332                                  * JRA.
 333                                  */
 334
 335                                 if (vfs_stat(conn,name, &st) == 0) {
 336                                         *pst = st;
 337                                 } else {
 338                                         ZERO_STRUCT(st);
 339                                 }
 340                         }
 341                 } /* end else */
 342
 343                 /*
 344                  * Add to the dirpath that we have resolved so far.
 345                  */
 346                 if (*dirpath)
 347                         pstrcat(dirpath,"/");
 348
 349                 pstrcat(dirpath,start);
 350
 351                 /*
 352                  * Don't cache a name with mangled or wildcard components
 353                  * as this can change the size.
 354                  */
 355
 356                 if(!component_was_mangled && !name_has_wildcard)
 357                         stat_cache_add(orig_path, dirpath);
 358
 359                 /*
 360                  * Restore the / that we wiped out earlier.
 361                  */
 362                 if (end)
 363                         *end = '/';
 364         }
 365
 366         /*
 367          * Don't cache a name with mangled or wildcard components
 368          * as this can change the size.
 369          */
 370
 371         if(!component_was_mangled && !name_has_wildcard)
 372                 stat_cache_add(orig_path, name);
 373
 374         /*
 375          * If we ended up resolving the entire path then return a valid
 376          * stat struct if we got one.
 377          */
 378
 379         if (VALID_STAT(st) && (strlen(orig_path) == strlen(name)))
 380                 *pst = st;
 381
 382         /*
 383          * The name has been resolved.
 384          */
 385
 386         DEBUG(5,("conversion finished %s -> %s\n",orig_path, name));
 387         return(True);
 388 }
 389
 390 /****************************************************************************
 391  Check a filename - possibly caling reducename.
 392  This is called by every routine before it allows an operation on a filename.
 393  It does any final confirmation necessary to ensure that the filename is
 394  a valid one for the user to access.
 395 ****************************************************************************/
 396
 397 BOOL check_name(pstring name,connection_struct *conn)
 398 {
 399         BOOL ret;
 400
 401         errno = 0;
 402
 403         if (IS_VETO_PATH(conn, name))  {
 404                 if(strcmp(name, ".") && strcmp(name, "..")) {
 405                         DEBUG(5,("file path name %s vetoed\n",name));
 406                         return(0);
 407                 }
 408         }
 409
 410         ret = reduce_name(conn,name,conn->connectpath,lp_widelinks(SNUM(conn)));
 411
 412         /* Check if we are allowing users to follow symlinks */
 413         /* Patch from David Clerc <David.Clerc@cui.unige.ch>
 414                 University of Geneva */
 415
 416 #ifdef S_ISLNK
 417         if (!lp_symlinks(SNUM(conn))) {
 418                 SMB_STRUCT_STAT statbuf;
 419                 if ( (conn->vfs_ops.lstat(conn,name,&statbuf) != -1) &&
 420                                 (S_ISLNK(statbuf.st_mode)) ) {
 421                         DEBUG(3,("check_name: denied: file path name %s is a symlink\n",name));
 422                         ret=0;
 423                 }
 424         }
 425 #endif
 426
 427         if (!ret)
 428                 DEBUG(5,("check_name on %s failed\n",name));
 429
 430         return(ret);
 431 }
 432
 433 /****************************************************************************
 434  Scan a directory to find a filename, matching without case sensitivity.
 435  If the name looks like a mangled name then try via the mangling functions
 436 ****************************************************************************/
 437
 438 static BOOL scan_directory(const char *path, char *name, size_t maxlength,
 439                            connection_struct *conn,BOOL docache)
 440 {
 441         void *cur_dir;
 442         char *dname;
 443         BOOL mangled;
 444
 445         mangled = mangle_is_mangled(name);
 446
 447         /* handle null paths */
 448         if (*path == 0)
 449                 path = ".";
 450
 451         if (docache && (dname = DirCacheCheck(path,name,SNUM(conn)))) {
 452                 safe_strcpy(name, dname, maxlength);
 453                 return(True);
 454         }
 455
 456         /*
 457          * The incoming name can be mangled, and if we de-mangle it
 458          * here it will not compare correctly against the filename (name2)
 459          * read from the directory and then mangled by the mangle_map()
 460          * call. We need to mangle both names or neither.
 461          * (JRA).
 462          */
 463         if (mangled)
 464                 mangled = !mangle_check_cache( name );
 465
 466         /* open the directory */
 467         if (!(cur_dir = OpenDir(conn, path, True))) {
 468                 DEBUG(3,("scan dir didn't open dir [%s]\n",path));
 469                 return(False);
 470         }
 471
 472         /* now scan for matching names */
 473         while ((dname = ReadDirName(cur_dir))) {
 474                 if (*dname == '.' && (strequal(dname,".") || strequal(dname,"..")))
 475                         continue;
 476
 477                 /*
 478                  * At this point dname is the unmangled name.
 479                  * name is either mangled or not, depending on the state of the "mangled"
 480                  * variable. JRA.
 481                  */
 482
 483                 /*
 484                  * Check mangled name against mangled name, or unmangled name
 485                  * against unmangled name.
 486                  */
 487
 488                 if ((mangled && mangled_equal(name,dname,SNUM(conn))) || fname_equal(name, dname)) {
 489                         /* we've found the file, change it's name and return */
 490                         if (docache)
 491                                 DirCacheAdd(path,name,dname,SNUM(conn));
 492                         safe_strcpy(name, dname, maxlength);
 493                         CloseDir(cur_dir);
 494                         return(True);
 495                 }
 496         }
 497
 498         CloseDir(cur_dir);
 499         return(False);
 500 }