source4/scripting/python/samba/ntacls.py

   1 #!/usr/bin/env python
   2
   3 # Unix SMB/CIFS implementation.
   4 # Copyright (C) Matthieu Patou <mat@matws.net> 2009-2010
   5 #
   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 3 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, see <http://www.gnu.org/licenses/>.
  19 #
  20
  21 """NT Acls."""
  22
  23
  24 import os
  25 import samba.xattr_native, samba.xattr_tdb
  26 from samba.dcerpc import security, xattr
  27 from samba.ndr import ndr_pack, ndr_unpack
  28
  29 class XattrBackendError(Exception):
  30     """A generic xattr backend error."""
  31
  32
  33 def checkset_backend(lp, backend, eadbfile):
  34     '''return the path to the eadb, or None'''
  35     if backend is None:
  36         return lp.get("posix:eadb")
  37     elif backend == "native":
  38         return None
  39     elif backend == "tdb":
  40         if eadbfile is not None:
  41             return eadbfile
  42         else:
  43             return os.path.abspath(os.path.join(lp.get("private dir"), "eadb.tdb"))
  44     else:
  45         raise XattrBackendError("Invalid xattr backend choice %s"%backend)
  46
  47
  48 def getntacl(lp, file, backend=None, eadbfile=None):
  49     eadbname = checkset_backend(lp, backend, eadbfile)
  50     if eadbname is not None:
  51         try:
  52             attribute = samba.xattr_tdb.wrap_getxattr(eadbname, file,
  53                 xattr.XATTR_NTACL_NAME)
  54         except Exception:
  55             # FIXME: Don't catch all exceptions, just those related to opening
  56             # xattrdb
  57             print "Fail to open %s" % eadbname
  58             attribute = samba.xattr_native.wrap_getxattr(file,
  59                 xattr.XATTR_NTACL_NAME)
  60     else:
  61         attribute = samba.xattr_native.wrap_getxattr(file,
  62             xattr.XATTR_NTACL_NAME)
  63     ntacl = ndr_unpack(xattr.NTACL, attribute)
  64     return ntacl
  65
  66
  67 def setntacl(lp, file, sddl, domsid, backend=None, eadbfile=None):
  68     eadbname = checkset_backend(lp, backend, eadbfile)
  69     ntacl = xattr.NTACL()
  70     ntacl.version = 1
  71     sid = security.dom_sid(domsid)
  72     sd = security.descriptor.from_sddl(sddl, sid)
  73     ntacl.info = sd
  74     if eadbname is not None:
  75         try:
  76             samba.xattr_tdb.wrap_setxattr(eadbname,
  77                 file, xattr.XATTR_NTACL_NAME, ndr_pack(ntacl))
  78         except Exception:
  79             # FIXME: Don't catch all exceptions, just those related to opening
  80             # xattrdb
  81             print "Fail to open %s" % eadbname
  82             samba.xattr_native.wrap_setxattr(file, xattr.XATTR_NTACL_NAME,
  83                 ndr_pack(ntacl))
  84     else:
  85         samba.xattr_native.wrap_setxattr(file, xattr.XATTR_NTACL_NAME,
  86                 ndr_pack(ntacl))
  87
  88
  89 def ldapmask2filemask(ldm):
  90     """Takes the access mask of a DS ACE and transform them in a File ACE mask.
  91     """
  92     RIGHT_DS_CREATE_CHILD     = 0x00000001
  93     RIGHT_DS_DELETE_CHILD     = 0x00000002
  94     RIGHT_DS_LIST_CONTENTS    = 0x00000004
  95     ACTRL_DS_SELF             = 0x00000008
  96     RIGHT_DS_READ_PROPERTY    = 0x00000010
  97     RIGHT_DS_WRITE_PROPERTY   = 0x00000020
  98     RIGHT_DS_DELETE_TREE      = 0x00000040
  99     RIGHT_DS_LIST_OBJECT      = 0x00000080
 100     RIGHT_DS_CONTROL_ACCESS   = 0x00000100
 101     FILE_READ_DATA            = 0x0001
 102     FILE_LIST_DIRECTORY       = 0x0001
 103     FILE_WRITE_DATA           = 0x0002
 104     FILE_ADD_FILE             = 0x0002
 105     FILE_APPEND_DATA          = 0x0004
 106     FILE_ADD_SUBDIRECTORY     = 0x0004
 107     FILE_CREATE_PIPE_INSTANCE = 0x0004
 108     FILE_READ_EA              = 0x0008
 109     FILE_WRITE_EA             = 0x0010
 110     FILE_EXECUTE              = 0x0020
 111     FILE_TRAVERSE             = 0x0020
 112     FILE_DELETE_CHILD         = 0x0040
 113     FILE_READ_ATTRIBUTES      = 0x0080
 114     FILE_WRITE_ATTRIBUTES     = 0x0100
 115     DELETE                    = 0x00010000
 116     READ_CONTROL              = 0x00020000
 117     WRITE_DAC                 = 0x00040000
 118     WRITE_OWNER               = 0x00080000
 119     SYNCHRONIZE               = 0x00100000
 120     STANDARD_RIGHTS_ALL       = 0x001F0000
 121
 122     filemask = ldm & STANDARD_RIGHTS_ALL
 123
 124     if (ldm & RIGHT_DS_READ_PROPERTY) and (ldm & RIGHT_DS_LIST_CONTENTS):
 125         filemask = filemask | (SYNCHRONIZE | FILE_LIST_DIRECTORY |\
 126                                 FILE_READ_ATTRIBUTES | FILE_READ_EA |\
 127                                 FILE_READ_DATA | FILE_EXECUTE)
 128
 129     if ldm & RIGHT_DS_WRITE_PROPERTY:
 130         filemask = filemask | (SYNCHRONIZE | FILE_WRITE_DATA |\
 131                                 FILE_APPEND_DATA | FILE_WRITE_EA |\
 132                                 FILE_WRITE_ATTRIBUTES | FILE_ADD_FILE |\
 133                                 FILE_ADD_SUBDIRECTORY)
 134
 135     if ldm & RIGHT_DS_CREATE_CHILD:
 136         filemask = filemask | (FILE_ADD_SUBDIRECTORY | FILE_ADD_FILE)
 137
 138     if ldm & RIGHT_DS_DELETE_CHILD:
 139         filemask = filemask | FILE_DELETE_CHILD
 140
 141     return filemask
 142
 143
 144 def dsacl2fsacl(dssddl, domsid):
 145     """
 146
 147     This function takes an the SDDL representation of a DS
 148     ACL and return the SDDL representation of this ACL adapted
 149     for files. It's used for Policy object provision
 150     """
 151     sid = security.dom_sid(domsid)
 152     ref = security.descriptor.from_sddl(dssddl, sid)
 153     fdescr = security.descriptor()
 154     fdescr.owner_sid = ref.owner_sid
 155     fdescr.group_sid = ref.group_sid
 156     fdescr.type = ref.type
 157     fdescr.revision = ref.revision
 158     fdescr.sacl = ref.sacl
 159     aces = ref.dacl.aces
 160     for i in range(0, len(aces)):
 161         ace = aces[i]
 162         if not ace.type & security.SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT and str(ace.trustee) != security.SID_BUILTIN_PREW2K:
 163        #    if fdescr.type & security.SEC_DESC_DACL_AUTO_INHERITED:
 164             ace.flags = ace.flags | security.SEC_ACE_FLAG_OBJECT_INHERIT | security.SEC_ACE_FLAG_CONTAINER_INHERIT
 165             if str(ace.trustee) == security.SID_CREATOR_OWNER:
 166                 # For Creator/Owner the IO flag is set as this ACE has only a sense for child objects
 167                 ace.flags = ace.flags | security.SEC_ACE_FLAG_INHERIT_ONLY
 168             ace.access_mask =  ldapmask2filemask(ace.access_mask)
 169             fdescr.dacl_add(ace)
 170
 171     return fdescr.as_sddl(sid)