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(const char *name1, const 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(const 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 (SMB_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 (SMB_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                         if (!end) {
 252                                 /*
 253                                  * We just scanned for, and found the end of the path.
 254                                  * We must return the valid stat struct.
 255                                  * JRA.
 256                                  */
 257
 258                                 *pst = st;
 259                         }
 260
 261                 } else {
 262                         pstring rest;
 263
 264                         /* Stat failed - ensure we don't use it. */
 265                         ZERO_STRUCT(st);
 266                         *rest = 0;
 267
 268                         /*
 269                          * Remember the rest of the pathname so it can be restored
 270                          * later.
 271                          */
 272
 273                         if (end)
 274                                 pstrcpy(rest,end+1);
 275
 276                         /*
 277                          * Try to find this part of the path in the directory.
 278                          */
 279
 280                         if (ms_has_wild(start) ||
 281                             !scan_directory(dirpath, start,
 282                                             sizeof(pstring) - 1 - (start - name),
 283                                             conn,
 284                                             end?True:False)) {
 285                                 if (end) {
 286                                         /*
 287                                          * An intermediate part of the name can't be found.
 288                                          */
 289                                         DEBUG(5,("Intermediate not found %s\n",start));
 290                                         *end = '/';
 291
 292                                         /*
 293                                          * We need to return the fact that the intermediate
 294                                          * name resolution failed. This is used to return an
 295                                          * error of ERRbadpath rather than ERRbadfile. Some
 296                                          * Windows applications depend on the difference between
 297                                          * these two errors.
 298                                          */
 299                                         *bad_path = True;
 300                                         return(False);
 301                                 }
 302
 303                                 /*
 304                                  * Just the last part of the name doesn't exist.
 305                                  * We may need to strupper() or strlower() it in case
 306                                  * this conversion is being used for file creation
 307                                  * purposes. If the filename is of mixed case then
 308                                  * don't normalise it.
 309                                  */
 310
 311                                 if (!case_preserve && (!strhasupper(start) || !strhaslower(start)))
 312                                         strnorm(start);
 313
 314                                 /*
 315                                  * check on the mangled stack to see if we can recover the
 316                                  * base of the filename.
 317                                  */
 318
 319                                 if (mangle_is_mangled(start)) {
 320                                         mangle_check_cache( start );
 321                                 }
 322
 323                                 DEBUG(5,("New file %s\n",start));
 324                                 return(True);
 325                         }
 326
 327                         /*
 328                          * Restore the rest of the string. If the string was mangled the size
 329                          * may have changed.
 330                          */
 331                         if (end) {
 332                                 end = start + strlen(start);
 333                                 if (!safe_strcat(start, "/", sizeof(pstring) - 1 - (start - name)) ||
 334                                     !safe_strcat(start, rest, sizeof(pstring) - 1 - (start - name))) {
 335                                         return False;
 336                                 }
 337                                 *end = '\0';
 338                         } else {
 339                                 /*
 340                                  * We just scanned for, and found the end of the path.
 341                                  * We must return a valid stat struct if it exists.
 342                                  * JRA.
 343                                  */
 344
 345                                 if (SMB_VFS_STAT(conn,name, &st) == 0) {
 346                                         *pst = st;
 347                                 } else {
 348                                         ZERO_STRUCT(st);
 349                                 }
 350                         }
 351                 } /* end else */
 352
 353                 /*
 354                  * Add to the dirpath that we have resolved so far.
 355                  */
 356                 if (*dirpath)
 357                         pstrcat(dirpath,"/");
 358
 359                 pstrcat(dirpath,start);
 360
 361                 /*
 362                  * Don't cache a name with mangled or wildcard components
 363                  * as this can change the size.
 364                  */
 365
 366                 if(!component_was_mangled && !name_has_wildcard)
 367                         stat_cache_add(orig_path, dirpath);
 368
 369                 /*
 370                  * Restore the / that we wiped out earlier.
 371                  */
 372                 if (end)
 373                         *end = '/';
 374         }
 375
 376         /*
 377          * Don't cache a name with mangled or wildcard components
 378          * as this can change the size.
 379          */
 380
 381         if(!component_was_mangled && !name_has_wildcard)
 382                 stat_cache_add(orig_path, name);
 383
 384         /*
 385          * The name has been resolved.
 386          */
 387
 388         DEBUG(5,("conversion finished %s -> %s\n",orig_path, name));
 389         return(True);
 390 }
 391
 392 /****************************************************************************
 393  Check a filename - possibly caling reducename.
 394  This is called by every routine before it allows an operation on a filename.
 395  It does any final confirmation necessary to ensure that the filename is
 396  a valid one for the user to access.
 397 ****************************************************************************/
 398
 399 BOOL check_name(pstring name,connection_struct *conn)
 400 {
 401         BOOL ret;
 402
 403         errno = 0;
 404
 405         if (IS_VETO_PATH(conn, name))  {
 406                 if(strcmp(name, ".") && strcmp(name, "..")) {
 407                         DEBUG(5,("file path name %s vetoed\n",name));
 408                         return(0);
 409                 }
 410         }
 411
 412         ret = reduce_name(conn,name,conn->connectpath,lp_widelinks(SNUM(conn)));
 413
 414         /* Check if we are allowing users to follow symlinks */
 415         /* Patch from David Clerc <David.Clerc@cui.unige.ch>
 416                 University of Geneva */
 417
 418 #ifdef S_ISLNK
 419         if (!lp_symlinks(SNUM(conn))) {
 420                 SMB_STRUCT_STAT statbuf;
 421                 if ( (SMB_VFS_LSTAT(conn,name,&statbuf) != -1) &&
 422                                 (S_ISLNK(statbuf.st_mode)) ) {
 423                         DEBUG(3,("check_name: denied: file path name %s is a symlink\n",name));
 424                         ret=0;
 425                 }
 426         }
 427 #endif
 428
 429         if (!ret)
 430                 DEBUG(5,("check_name on %s failed\n",name));
 431
 432         return(ret);
 433 }
 434
 435 /****************************************************************************
 436  Scan a directory to find a filename, matching without case sensitivity.
 437  If the name looks like a mangled name then try via the mangling functions
 438 ****************************************************************************/
 439
 440 static BOOL scan_directory(const char *path, char *name, size_t maxlength,
 441                            connection_struct *conn,BOOL docache)
 442 {
 443         void *cur_dir;
 444         const char *dname;
 445         BOOL mangled;
 446
 447         mangled = mangle_is_mangled(name);
 448
 449         /* handle null paths */
 450         if (*path == 0)
 451                 path = ".";
 452
 453         if (docache && (dname = DirCacheCheck(path,name,SNUM(conn)))) {
 454                 safe_strcpy(name, dname, maxlength);
 455                 return(True);
 456         }
 457
 458         /*
 459          * The incoming name can be mangled, and if we de-mangle it
 460          * here it will not compare correctly against the filename (name2)
 461          * read from the directory and then mangled by the mangle_map()
 462          * call. We need to mangle both names or neither.
 463          * (JRA).
 464          */
 465         if (mangled)
 466                 mangled = !mangle_check_cache( name );
 467
 468         /* open the directory */
 469         if (!(cur_dir = OpenDir(conn, path, True))) {
 470                 DEBUG(3,("scan dir didn't open dir [%s]\n",path));
 471                 return(False);
 472         }
 473
 474         /* now scan for matching names */
 475         while ((dname = ReadDirName(cur_dir))) {
 476                 if (*dname == '.' && (strequal(dname,".") || strequal(dname,"..")))
 477                         continue;
 478
 479                 /*
 480                  * At this point dname is the unmangled name.
 481                  * name is either mangled or not, depending on the state of the "mangled"
 482                  * variable. JRA.
 483                  */
 484
 485                 /*
 486                  * Check mangled name against mangled name, or unmangled name
 487                  * against unmangled name.
 488                  */
 489
 490                 if ((mangled && mangled_equal(name,dname,SNUM(conn))) || fname_equal(name, dname)) {
 491                         /* we've found the file, change it's name and return */
 492                         if (docache)
 493                                 DirCacheAdd(path,name,dname,SNUM(conn));
 494                         safe_strcpy(name, dname, maxlength);
 495                         CloseDir(cur_dir);
 496                         return(True);
 497                 }
 498         }
 499
 500         CloseDir(cur_dir);
 501         return(False);
 502 }