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