source3/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 1999-2004
   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 static BOOL scan_directory(const char *path, char *name,size_t maxlength,
  30                            connection_struct *conn,BOOL docache);
  31
  32 /****************************************************************************
  33  Check if two filenames are equal.
  34  This needs to be careful about whether we are case sensitive.
  35 ****************************************************************************/
  36
  37 static BOOL fname_equal(const char *name1, const char *name2, BOOL case_sensitive)
  38 {
  39         /* Normal filename handling */
  40         if (case_sensitive)
  41                 return(strcmp(name1,name2) == 0);
  42
  43         return(strequal(name1,name2));
  44 }
  45
  46 /****************************************************************************
  47  Mangle the 2nd name and check if it is then equal to the first name.
  48 ****************************************************************************/
  49
  50 static BOOL mangled_equal(const char *name1, const char *name2, int snum)
  51 {
  52         pstring tmpname;
  53
  54         pstrcpy(tmpname, name2);
  55         mangle_map(tmpname, True, False, snum);
  56         return strequal(name1, tmpname);
  57 }
  58
  59 /****************************************************************************
  60 This routine is called to convert names from the dos namespace to unix
  61 namespace. It needs to handle any case conversions, mangling, format
  62 changes etc.
  63
  64 We assume that we have already done a chdir() to the right "root" directory
  65 for this service.
  66
  67 The function will return False if some part of the name except for the last
  68 part cannot be resolved
  69
  70 If the saved_last_component != 0, then the unmodified last component
  71 of the pathname is returned there. This is used in an exceptional
  72 case in reply_mv (so far). If saved_last_component == 0 then nothing
  73 is returned there.
  74
  75 The bad_path arg is set to True if the filename walk failed. This is
  76 used to pick the correct error code to return between ENOENT and ENOTDIR
  77 as Windows applications depend on ERRbadpath being returned if a component
  78 of a pathname does not exist.
  79
  80 On exit from unix_convert, if *pst was not null, then the file stat
  81 struct will be returned if the file exists and was found, if not this
  82 stat struct will be filled with zeros (and this can be detected by checking
  83 for nlinks = 0, which can never be true for any file).
  84 ****************************************************************************/
  85
  86 BOOL unix_convert(pstring name,connection_struct *conn,char *saved_last_component,
  87                   BOOL *bad_path, SMB_STRUCT_STAT *pst)
  88 {
  89         SMB_STRUCT_STAT st;
  90         char *start, *end;
  91         pstring dirpath;
  92         pstring orig_path;
  93         BOOL component_was_mangled = False;
  94         BOOL name_has_wildcard = False;
  95
  96         ZERO_STRUCTP(pst);
  97
  98         *dirpath = 0;
  99         *bad_path = False;
 100         if(saved_last_component)
 101                 *saved_last_component = 0;
 102
 103         if (conn->printer) {
 104                 /* we don't ever use the filenames on a printer share as a
 105                         filename - so don't convert them */
 106                 return True;
 107         }
 108
 109         DEBUG(5, ("unix_convert called on file \"%s\"\n", name));
 110
 111         /*
 112          * Conversion to basic unix format is already done in check_path_syntax().
 113          */
 114
 115         /*
 116          * Names must be relative to the root of the service - any leading /.
 117          * and trailing /'s should have been trimmed by check_path_syntax().
 118          */
 119
 120 #ifdef DEVELOPER
 121         SMB_ASSERT(*name != '/');
 122 #endif
 123
 124         /*
 125          * If we trimmed down to a single '\0' character
 126          * then we should use the "." directory to avoid
 127          * searching the cache, but not if we are in a
 128          * printing share.
 129          * As we know this is valid we can return true here.
 130          */
 131
 132         if (!*name) {
 133                 name[0] = '.';
 134                 name[1] = '\0';
 135                 return(True);
 136         }
 137
 138         /*
 139          * Ensure saved_last_component is valid even if file exists.
 140          */
 141
 142         if(saved_last_component) {
 143                 end = strrchr_m(name, '/');
 144                 if(end)
 145                         pstrcpy(saved_last_component, end + 1);
 146                 else
 147                         pstrcpy(saved_last_component, name);
 148         }
 149
 150 #if 1
 151         if (!conn->case_preserve || (mangle_is_8_3(name, False) && !conn->short_case_preserve))
 152 #else
 153         if (!conn->case_sensitive && (!conn->case_preserve || (mangle_is_8_3(name, False) && !conn->short_case_preserve)))
 154 #endif
 155                 strnorm(name, lp_defaultcase(SNUM(conn)));
 156
 157         start = name;
 158         pstrcpy(orig_path, name);
 159
 160         if(!conn->case_sensitive && stat_cache_lookup(conn, name, dirpath, &start, &st)) {
 161                 *pst = st;
 162                 return True;
 163         }
 164
 165         /*
 166          * stat the name - if it exists then we are all done!
 167          */
 168
 169         if (SMB_VFS_STAT(conn,name,&st) == 0) {
 170                 stat_cache_add(orig_path, name, conn->case_sensitive);
 171                 DEBUG(5,("conversion finished %s -> %s\n",orig_path, name));
 172                 *pst = st;
 173                 return(True);
 174         }
 175
 176         DEBUG(5,("unix_convert begin: name = %s, dirpath = %s, start = %s\n", name, dirpath, start));
 177
 178         /*
 179          * A special case - if we don't have any mangling chars and are case
 180          * sensitive then searching won't help.
 181          */
 182
 183         if (conn->case_sensitive && !mangle_is_mangled(name) && !*lp_mangled_map(SNUM(conn)))
 184                 return(False);
 185
 186         name_has_wildcard = ms_has_wild(start);
 187
 188         /*
 189          * is_mangled() was changed to look at an entire pathname, not
 190          * just a component. JRA.
 191          */
 192
 193         if (mangle_is_mangled(start))
 194                 component_was_mangled = True;
 195
 196         /*
 197          * Now we need to recursively match the name against the real
 198          * directory structure.
 199          */
 200
 201         /*
 202          * Match each part of the path name separately, trying the names
 203          * as is first, then trying to scan the directory for matching names.
 204          */
 205
 206         for (; start ; start = (end?end+1:(char *)NULL)) {
 207                 /*
 208                  * Pinpoint the end of this section of the filename.
 209                  */
 210                 end = strchr_m(start, '/');
 211
 212                 /*
 213                  * Chop the name at this point.
 214                  */
 215                 if (end)
 216                         *end = 0;
 217
 218                 if(saved_last_component != 0)
 219                         pstrcpy(saved_last_component, end ? end + 1 : start);
 220
 221                 /*
 222                  * Check if the name exists up to this point.
 223                  */
 224
 225                 if (SMB_VFS_STAT(conn,name, &st) == 0) {
 226                         /*
 227                          * It exists. it must either be a directory or this must be
 228                          * the last part of the path for it to be OK.
 229                          */
 230                         if (end && !(st.st_mode & S_IFDIR)) {
 231                                 /*
 232                                  * An intermediate part of the name isn't a directory.
 233                                  */
 234                                 DEBUG(5,("Not a dir %s\n",start));
 235                                 *end = '/';
 236                                 return(False);
 237                         }
 238
 239                         if (!end) {
 240                                 /*
 241                                  * We just scanned for, and found the end of the path.
 242                                  * We must return the valid stat struct.
 243                                  * JRA.
 244                                  */
 245
 246                                 *pst = st;
 247                         }
 248
 249                 } else {
 250                         pstring rest;
 251
 252                         /* Stat failed - ensure we don't use it. */
 253                         ZERO_STRUCT(st);
 254                         *rest = 0;
 255
 256                         /*
 257                          * Remember the rest of the pathname so it can be restored
 258                          * later.
 259                          */
 260
 261                         if (end)
 262                                 pstrcpy(rest,end+1);
 263
 264                         /*
 265                          * Try to find this part of the path in the directory.
 266                          */
 267
 268                         if (ms_has_wild(start) ||
 269                             !scan_directory(dirpath, start,
 270                                             sizeof(pstring) - 1 - (start - name),
 271                                             conn,
 272                                             end?True:False)) {
 273                                 if (end) {
 274                                         /*
 275                                          * An intermediate part of the name can't be found.
 276                                          */
 277                                         DEBUG(5,("Intermediate not found %s\n",start));
 278                                         *end = '/';
 279
 280                                         /*
 281                                          * We need to return the fact that the intermediate
 282                                          * name resolution failed. This is used to return an
 283                                          * error of ERRbadpath rather than ERRbadfile. Some
 284                                          * Windows applications depend on the difference between
 285                                          * these two errors.
 286                                          */
 287                                         *bad_path = True;
 288                                         return(False);
 289                                 }
 290
 291                                 /*
 292                                  * Just the last part of the name doesn't exist.
 293                                  * We may need to strupper() or strlower() it in case
 294                                  * this conversion is being used for file creation
 295                                  * purposes. If the filename is of mixed case then
 296                                  * don't normalise it.
 297                                  */
 298
 299                                 if (!conn->case_preserve && (!strhasupper(start) || !strhaslower(start)))
 300                                         strnorm(start, lp_defaultcase(SNUM(conn)));
 301
 302                                 /*
 303                                  * check on the mangled stack to see if we can recover the
 304                                  * base of the filename.
 305                                  */
 306
 307                                 if (mangle_is_mangled(start)) {
 308                                         mangle_check_cache( start );
 309                                 }
 310
 311                                 DEBUG(5,("New file %s\n",start));
 312                                 return(True);
 313                         }
 314
 315                         /*
 316                          * Restore the rest of the string. If the string was mangled the size
 317                          * may have changed.
 318                          */
 319                         if (end) {
 320                                 end = start + strlen(start);
 321                                 if (!safe_strcat(start, "/", sizeof(pstring) - 1 - (start - name)) ||
 322                                     !safe_strcat(start, rest, sizeof(pstring) - 1 - (start - name))) {
 323                                         return False;
 324                                 }
 325                                 *end = '\0';
 326                         } else {
 327                                 /*
 328                                  * We just scanned for, and found the end of the path.
 329                                  * We must return a valid stat struct if it exists.
 330                                  * JRA.
 331                                  */
 332
 333                                 if (SMB_VFS_STAT(conn,name, &st) == 0) {
 334                                         *pst = st;
 335                                 } else {
 336                                         ZERO_STRUCT(st);
 337                                 }
 338                         }
 339                 } /* end else */
 340
 341                 /*
 342                  * Add to the dirpath that we have resolved so far.
 343                  */
 344                 if (*dirpath)
 345                         pstrcat(dirpath,"/");
 346
 347                 pstrcat(dirpath,start);
 348
 349                 /*
 350                  * Don't cache a name with mangled or wildcard components
 351                  * as this can change the size.
 352                  */
 353
 354                 if(!component_was_mangled && !name_has_wildcard)
 355                         stat_cache_add(orig_path, dirpath, conn->case_sensitive);
 356
 357                 /*
 358                  * Restore the / that we wiped out earlier.
 359                  */
 360                 if (end)
 361                         *end = '/';
 362         }
 363
 364         /*
 365          * Don't cache a name with mangled or wildcard components
 366          * as this can change the size.
 367          */
 368
 369         if(!component_was_mangled && !name_has_wildcard)
 370                 stat_cache_add(orig_path, name, conn->case_sensitive);
 371
 372         /*
 373          * The name has been resolved.
 374          */
 375
 376         DEBUG(5,("conversion finished %s -> %s\n",orig_path, name));
 377         return(True);
 378 }
 379
 380 /****************************************************************************
 381  Check a filename - possibly caling reducename.
 382  This is called by every routine before it allows an operation on a filename.
 383  It does any final confirmation necessary to ensure that the filename is
 384  a valid one for the user to access.
 385 ****************************************************************************/
 386
 387 BOOL check_name(pstring name,connection_struct *conn)
 388 {
 389         BOOL ret = True;
 390
 391         errno = 0;
 392
 393         if (IS_VETO_PATH(conn, name))  {
 394                 /* Is it not dot or dot dot. */
 395                 if (!((name[0] == '.') && (!name[1] || (name[1] == '.' && !name[2])))) {
 396                         DEBUG(5,("file path name %s vetoed\n",name));
 397                         return False;
 398                 }
 399         }
 400
 401         if (!lp_widelinks(SNUM(conn))) {
 402                 ret = reduce_name(conn,name,conn->connectpath);
 403         }
 404
 405         /* Check if we are allowing users to follow symlinks */
 406         /* Patch from David Clerc <David.Clerc@cui.unige.ch>
 407                 University of Geneva */
 408
 409 #ifdef S_ISLNK
 410         if (!lp_symlinks(SNUM(conn))) {
 411                 SMB_STRUCT_STAT statbuf;
 412                 if ( (SMB_VFS_LSTAT(conn,name,&statbuf) != -1) &&
 413                                 (S_ISLNK(statbuf.st_mode)) ) {
 414                         DEBUG(3,("check_name: denied: file path name %s is a symlink\n",name));
 415                         ret = False;
 416                 }
 417         }
 418 #endif
 419
 420         if (!ret)
 421                 DEBUG(5,("check_name on %s failed\n",name));
 422
 423         return(ret);
 424 }
 425
 426 /****************************************************************************
 427  Scan a directory to find a filename, matching without case sensitivity.
 428  If the name looks like a mangled name then try via the mangling functions
 429 ****************************************************************************/
 430
 431 static BOOL scan_directory(const char *path, char *name, size_t maxlength,
 432                            connection_struct *conn,BOOL docache)
 433 {
 434         void *cur_dir;
 435         const char *dname;
 436         BOOL mangled;
 437
 438         mangled = mangle_is_mangled(name);
 439
 440         /* handle null paths */
 441         if (*path == 0)
 442                 path = ".";
 443
 444         if (docache && (dname = DirCacheCheck(path,name,SNUM(conn)))) {
 445                 safe_strcpy(name, dname, maxlength);
 446                 return(True);
 447         }
 448
 449         /*
 450          * The incoming name can be mangled, and if we de-mangle it
 451          * here it will not compare correctly against the filename (name2)
 452          * read from the directory and then mangled by the mangle_map()
 453          * call. We need to mangle both names or neither.
 454          * (JRA).
 455          */
 456         if (mangled)
 457                 mangled = !mangle_check_cache( name );
 458
 459         /* open the directory */
 460         if (!(cur_dir = OpenDir(conn, path, True))) {
 461                 DEBUG(3,("scan dir didn't open dir [%s]\n",path));
 462                 return(False);
 463         }
 464
 465         /* now scan for matching names */
 466         while ((dname = ReadDirName(cur_dir))) {
 467
 468                 /* Is it dot or dot dot. */
 469                 if ((dname[0] == '.') && (!dname[1] || (dname[1] == '.' && !dname[2]))) {
 470                         continue;
 471                 }
 472
 473                 /*
 474                  * At this point dname is the unmangled name.
 475                  * name is either mangled or not, depending on the state of the "mangled"
 476                  * variable. JRA.
 477                  */
 478
 479                 /*
 480                  * Check mangled name against mangled name, or unmangled name
 481                  * against unmangled name.
 482                  */
 483
 484                 if ((mangled && mangled_equal(name,dname,SNUM(conn))) || fname_equal(name, dname, conn->case_sensitive)) {
 485                         /* we've found the file, change it's name and return */
 486                         if (docache)
 487                                 DirCacheAdd(path,name,dname,SNUM(conn));
 488                         safe_strcpy(name, dname, maxlength);
 489                         CloseDir(cur_dir);
 490                         return(True);
 491                 }
 492         }
 493
 494         CloseDir(cur_dir);
 495         return(False);
 496 }