source/smbd/dosmode.c

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