source/smbd/dosmode.c

   1 #define OLD_NTDOMAIN 1
   2
   3 /*
   4    Unix SMB/Netbios implementation.
   5    Version 1.9.
   6    dos mode handling functions
   7    Copyright (C) Andrew Tridgell 1992-1998
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25
  26 extern int DEBUGLEVEL;
  27
  28 /****************************************************************************
  29   change a dos mode to a unix mode
  30     base permission for files:
  31          if inheriting
  32            apply read/write bits from parent directory.
  33          else
  34            everybody gets read bit set
  35          dos readonly is represented in unix by removing everyone's write bit
  36          dos archive is represented in unix by the user's execute bit
  37          dos system is represented in unix by the group's execute bit
  38          dos hidden is represented in unix by the other's execute bit
  39          if !inheriting {
  40            Then apply create mask,
  41            then add force bits.
  42          }
  43     base permission for directories:
  44          dos directory is represented in unix by unix's dir bit and the exec bit
  45          if !inheriting {
  46            Then apply create mask,
  47            then add force bits.
  48          }
  49 ****************************************************************************/
  50 mode_t unix_mode(connection_struct *conn,int dosmode,const char *fname)
  51 {
  52   mode_t result = (S_IRUSR | S_IRGRP | S_IROTH);
  53   mode_t dir_mode = 0; /* Mode of the parent directory if inheriting. */
  54
  55   if ( !IS_DOS_READONLY(dosmode) )
  56     result |= (S_IWUSR | S_IWGRP | S_IWOTH);
  57
  58   if (fname && lp_inherit_perms(SNUM(conn))) {
  59     char *dname;
  60     SMB_STRUCT_STAT sbuf;
  61
  62     dname = parent_dirname(fname);
  63     DEBUG(2,("unix_mode(%s) inheriting from %s\n",fname,dname));
  64     if (vfs_stat(conn,dname,&sbuf) != 0) {
  65       DEBUG(4,("unix_mode(%s) failed, [dir %s]: %s\n",fname,dname,strerror(errno)));
  66       return(0);      /* *** shouldn't happen! *** */
  67     }
  68
  69     /* Save for later - but explicitly remove setuid bit for safety. */
  70     dir_mode = sbuf.st_mode & ~S_ISUID;
  71     DEBUG(2,("unix_mode(%s) inherit mode %o\n",fname,(int)dir_mode));
  72     /* Clear "result" */
  73     result = 0;
  74   }
  75
  76   if (IS_DOS_DIR(dosmode)) {
  77     /* We never make directories read only for the owner as under DOS a user
  78        can always create a file in a read-only directory. */
  79     result |= (S_IFDIR | S_IWUSR);
  80
  81     if (dir_mode) {
  82       /* Inherit mode of parent directory. */
  83       result |= dir_mode;
  84     } else {
  85       /* Provisionally add all 'x' bits */
  86       result |= (S_IXUSR | S_IXGRP | S_IXOTH);
  87
  88       /* Apply directory mask */
  89       result &= lp_dir_mask(SNUM(conn));
  90       /* Add in force bits */
  91       result |= lp_force_dir_mode(SNUM(conn));
  92     }
  93   } else {
  94     if (lp_map_archive(SNUM(conn)) && IS_DOS_ARCHIVE(dosmode))
  95       result |= S_IXUSR;
  96
  97     if (lp_map_system(SNUM(conn)) && IS_DOS_SYSTEM(dosmode))
  98       result |= S_IXGRP;
  99
 100     if (lp_map_hidden(SNUM(conn)) && IS_DOS_HIDDEN(dosmode))
 101       result |= S_IXOTH;
 102
 103     if (dir_mode) {
 104       /* Inherit 666 component of parent directory mode */
 105       result |= dir_mode
 106         &  (S_IRUSR | S_IRGRP | S_IROTH | S_IWUSR | S_IWGRP | S_IWOTH);
 107     } else {
 108       /* Apply mode mask */
 109       result &= lp_create_mask(SNUM(conn));
 110       /* Add in force bits */
 111       result |= lp_force_create_mode(SNUM(conn));
 112     }
 113   }
 114   return(result);
 115 }
 116
 117
 118 /****************************************************************************
 119   change a unix mode to a dos mode
 120 ****************************************************************************/
 121 int dos_mode(connection_struct *conn,char *path,SMB_STRUCT_STAT *sbuf)
 122 {
 123   int result = 0;
 124
 125   DEBUG(8,("dos_mode: %s\n", path));
 126
 127   if ((sbuf->st_mode & S_IWUSR) == 0)
 128       result |= aRONLY;
 129
 130   if (MAP_ARCHIVE(conn) && ((sbuf->st_mode & S_IXUSR) != 0))
 131     result |= aARCH;
 132
 133   if (MAP_SYSTEM(conn) && ((sbuf->st_mode & S_IXGRP) != 0))
 134     result |= aSYSTEM;
 135
 136   if (MAP_HIDDEN(conn) && ((sbuf->st_mode & S_IXOTH) != 0))
 137     result |= aHIDDEN;
 138
 139   if (S_ISDIR(sbuf->st_mode))
 140     result = aDIR | (result & aRONLY);
 141
 142 #ifdef S_ISLNK
 143 #if LINKS_READ_ONLY
 144   if (S_ISLNK(sbuf->st_mode) && S_ISDIR(sbuf->st_mode))
 145     result |= aRONLY;
 146 #endif
 147 #endif
 148
 149   /* hide files with a name starting with a . */
 150   if (lp_hide_dot_files(SNUM(conn)))
 151     {
 152       char *p = strrchr(path,'/');
 153       if (p)
 154         p++;
 155       else
 156         p = path;
 157
 158       if (p[0] == '.' && p[1] != '.' && p[1] != 0)
 159         result |= aHIDDEN;
 160     }
 161
 162   /* Optimization : Only call is_hidden_path if it's not already
 163      hidden. */
 164   if (!(result & aHIDDEN) && IS_HIDDEN_PATH(conn,path))
 165   {
 166     result |= aHIDDEN;
 167   }
 168
 169   DEBUG(8,("dos_mode returning "));
 170
 171   if (result & aHIDDEN) DEBUG(8, ("h"));
 172   if (result & aRONLY ) DEBUG(8, ("r"));
 173   if (result & aSYSTEM) DEBUG(8, ("s"));
 174   if (result & aDIR   ) DEBUG(8, ("d"));
 175   if (result & aARCH  ) DEBUG(8, ("a"));
 176
 177   DEBUG(8,("\n"));
 178
 179   return(result);
 180 }
 181
 182 /*******************************************************************
 183 chmod a file - but preserve some bits
 184 ********************************************************************/
 185 int file_chmod(connection_struct *conn,char *fname,int dosmode,SMB_STRUCT_STAT *st)
 186 {
 187         extern struct current_user current_user;
 188         SMB_STRUCT_STAT st1;
 189         int mask=0;
 190         mode_t tmp;
 191         mode_t unixmode;
 192         int ret = -1;
 193
 194         if (!st) {
 195                 st = &st1;
 196                 if (vfs_stat(conn,fname,st))
 197                         return(-1);
 198         }
 199
 200         if (S_ISDIR(st->st_mode))
 201                 dosmode |= aDIR;
 202
 203         if (dos_mode(conn,fname,st) == dosmode)
 204                 return(0);
 205
 206         unixmode = unix_mode(conn,dosmode,fname);
 207
 208         /* preserve the s bits */
 209         mask |= (S_ISUID | S_ISGID);
 210
 211         /* preserve the t bit */
 212 #ifdef S_ISVTX
 213         mask |= S_ISVTX;
 214 #endif
 215
 216         /* possibly preserve the x bits */
 217         if (!MAP_ARCHIVE(conn))
 218                 mask |= S_IXUSR;
 219         if (!MAP_SYSTEM(conn))
 220                 mask |= S_IXGRP;
 221         if (!MAP_HIDDEN(conn))
 222                 mask |= S_IXOTH;
 223
 224         unixmode |= (st->st_mode & mask);
 225
 226         /* if we previously had any r bits set then leave them alone */
 227         if ((tmp = st->st_mode & (S_IRUSR|S_IRGRP|S_IROTH))) {
 228                 unixmode &= ~(S_IRUSR|S_IRGRP|S_IROTH);
 229                 unixmode |= tmp;
 230         }
 231
 232         /* if we previously had any w bits set then leave them alone
 233                 whilst adding in the new w bits, if the new mode is not rdonly */
 234         if (!IS_DOS_READONLY(dosmode)) {
 235                 unixmode |= (st->st_mode & (S_IWUSR|S_IWGRP|S_IWOTH));
 236         }
 237
 238         if ((ret = vfs_chmod(conn,fname,unixmode)) == 0)
 239                 return 0;
 240
 241         if((errno != EPERM) && (errno != EACCES))
 242                 return -1;
 243
 244         if(!lp_dos_filemode(SNUM(conn)))
 245                 return -1;
 246
 247         /* We want DOS semantics, ie allow non owner with write permission to change the
 248                 bits on a file. Just like file_utime below.
 249         */
 250
 251         /* Check if we have write access. */
 252         if (CAN_WRITE(conn)) {
 253                 if (((st->st_mode & S_IWOTH) ||
 254                                 conn->admin_user ||
 255                                 ((st->st_mode & S_IWUSR) && current_user.uid==st->st_uid) ||
 256                                 ((st->st_mode & S_IWGRP) &&
 257                                 in_group(st->st_gid,current_user.gid, current_user.ngroups,current_user.groups)))) {
 258                                         /* We are allowed to become root and change the file mode. */
 259                                         become_root();
 260                                         ret = vfs_chmod(conn,fname,unixmode);
 261                                         unbecome_root();
 262                 }
 263         }
 264
 265         return( ret );
 266 }
 267
 268
 269 /*******************************************************************
 270 Wrapper around dos_utime that possibly allows DOS semantics rather
 271 than POSIX.
 272 *******************************************************************/
 273 int file_utime(connection_struct *conn, char *fname, struct utimbuf *times)
 274 {
 275   extern struct current_user current_user;
 276   SMB_STRUCT_STAT sb;
 277   int ret = -1;
 278
 279   errno = 0;
 280
 281   if(conn->vfs_ops.utime(conn,dos_to_unix(fname, False), times) == 0)
 282     return 0;
 283
 284   if((errno != EPERM) && (errno != EACCES))
 285     return -1;
 286
 287   if(!lp_dos_filetimes(SNUM(conn)))
 288     return -1;
 289
 290   /* We have permission (given by the Samba admin) to
 291      break POSIX semantics and allow a user to change
 292      the time on a file they don't own but can write to
 293      (as DOS does).
 294    */
 295
 296   if(vfs_stat(conn,fname,&sb) != 0)
 297     return -1;
 298
 299   /* Check if we have write access. */
 300   if (CAN_WRITE(conn)) {
 301           if (((sb.st_mode & S_IWOTH) ||
 302                conn->admin_user ||
 303                ((sb.st_mode & S_IWUSR) && current_user.uid==sb.st_uid) ||
 304                ((sb.st_mode & S_IWGRP) &&
 305                 in_group(sb.st_gid,current_user.gid,
 306                          current_user.ngroups,current_user.groups)))) {
 307                   /* We are allowed to become root and change the filetime. */
 308                   become_root();
 309                   ret = conn->vfs_ops.utime(conn,dos_to_unix(fname, False), times);
 310                   unbecome_root();
 311           }
 312   }
 313
 314   return ret;
 315 }
 316
 317 /*******************************************************************
 318 Change a filetime - possibly allowing DOS semantics.
 319 *******************************************************************/
 320 BOOL set_filetime(connection_struct *conn, char *fname, time_t mtime)
 321 {
 322   struct utimbuf times;
 323
 324   if (null_mtime(mtime)) return(True);
 325
 326   times.modtime = times.actime = mtime;
 327
 328   if (file_utime(conn, fname, &times)) {
 329     DEBUG(4,("set_filetime(%s) failed: %s\n",fname,strerror(errno)));
 330     return False;
 331   }
 332
 333   return(True);
 334 }
 335
 336 #undef OLD_NTDOMAIN