source4/lib/ldb/common/ldb_attributes.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Andrew Tridgell  2005
   5
   6      ** NOTE! The following LGPL license applies to the ldb
   7      ** library. This does NOT imply that all of Samba is released
   8      ** under the LGPL
   9
  10    This library is free software; you can redistribute it and/or
  11    modify it under the terms of the GNU Lesser General Public
  12    License as published by the Free Software Foundation; either
  13    version 3 of the License, or (at your option) any later version.
  14
  15    This library is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    Lesser General Public License for more details.
  19
  20    You should have received a copy of the GNU Lesser General Public
  21    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  22 */
  23 /*
  24   register handlers for specific attributes and objectclass relationships
  25
  26   this allows a backend to store its schema information in any format
  27   it likes (or to not have any schema information at all) while keeping the
  28   message matching logic generic
  29 */
  30
  31 #include "ldb_includes.h"
  32
  33 /*
  34   add a attribute to the ldb_schema
  35
  36   if flags contains LDB_ATTR_FLAG_ALLOCATED
  37   the attribute name string will be copied using
  38   talloc_strdup(), otherwise it needs to be a static const
  39   string at least with a lifetime longer than the ldb struct!
  40
  41   the ldb_schema_syntax structure should be a pointer
  42   to a static const struct or at least it needs to be
  43   a struct with a longer lifetime than the ldb context!
  44
  45 */
  46 int ldb_schema_attribute_add_with_syntax(struct ldb_context *ldb,
  47                                          const char *attribute,
  48                                          unsigned flags,
  49                                          const struct ldb_schema_syntax *syntax)
  50 {
  51         int i, n;
  52         struct ldb_schema_attribute *a;
  53
  54         n = ldb->schema.num_attributes + 1;
  55
  56         a = talloc_realloc(ldb, ldb->schema.attributes,
  57                            struct ldb_schema_attribute, n);
  58         if (a == NULL) {
  59                 ldb_oom(ldb);
  60                 return -1;
  61         }
  62         ldb->schema.attributes = a;
  63
  64         for (i = 0; i < ldb->schema.num_attributes; i++) {
  65                 int cmp = ldb_attr_cmp(attribute, a[i].name);
  66                 if (cmp == 0) {
  67                         if (a[i].flags & LDB_ATTR_FLAG_ALLOCATED) {
  68                                 talloc_free(discard_const_p(char, a[i].name));
  69                         }
  70                         /* To cancel out increment below */
  71                         ldb->schema.num_attributes--;
  72                         break;
  73                 } else if (cmp < 0) {
  74                         memmove(a+i+1, a+i, sizeof(*a) * (ldb->schema.num_attributes-i));
  75                         break;
  76                 }
  77         }
  78         ldb->schema.num_attributes++;
  79
  80         a[i].name       = attribute;
  81         a[i].flags      = flags;
  82         a[i].syntax     = syntax;
  83
  84         if (a[i].flags & LDB_ATTR_FLAG_ALLOCATED) {
  85                 a[i].name = talloc_strdup(a, a[i].name);
  86                 if (a[i].name == NULL) {
  87                         ldb_oom(ldb);
  88                         return -1;
  89                 }
  90         }
  91
  92         return 0;
  93 }
  94
  95 static const struct ldb_schema_syntax ldb_syntax_default = {
  96         .name            = LDB_SYNTAX_OCTET_STRING,
  97         .ldif_read_fn    = ldb_handler_copy,
  98         .ldif_write_fn   = ldb_handler_copy,
  99         .canonicalise_fn = ldb_handler_copy,
 100         .comparison_fn   = ldb_comparison_binary
 101 };
 102
 103 static const struct ldb_schema_attribute ldb_attribute_default = {
 104         .name   = NULL,
 105         .flags  = 0,
 106         .syntax = &ldb_syntax_default
 107 };
 108
 109 /*
 110   return the attribute handlers for a given attribute
 111 */
 112 const struct ldb_schema_attribute *ldb_schema_attribute_by_name(struct ldb_context *ldb,
 113                                                                 const char *name)
 114 {
 115         int i, e, b = 0, r;
 116         const struct ldb_schema_attribute *def = &ldb_attribute_default;
 117
 118         /* as handlers are sorted, '*' must be the first if present */
 119         if (strcmp(ldb->schema.attributes[0].name, "*") == 0) {
 120                 def = &ldb->schema.attributes[0];
 121                 b = 1;
 122         }
 123
 124         /* do a binary search on the array */
 125         e = ldb->schema.num_attributes - 1;
 126
 127         while (b <= e) {
 128
 129                 i = (b + e) / 2;
 130
 131                 r = ldb_attr_cmp(name, ldb->schema.attributes[i].name);
 132                 if (r == 0) {
 133                         return &ldb->schema.attributes[i];
 134                 }
 135                 if (r < 0) {
 136                         e = i - 1;
 137                 } else {
 138                         b = i + 1;
 139                 }
 140
 141         }
 142
 143         return def;
 144 }
 145
 146
 147 /*
 148   add to the list of ldif handlers for this ldb context
 149 */
 150 void ldb_schema_attribute_remove(struct ldb_context *ldb, const char *name)
 151 {
 152         const struct ldb_schema_attribute *a;
 153         int i;
 154
 155         a = ldb_schema_attribute_by_name(ldb, name);
 156         if (a == NULL || a->name == NULL) {
 157                 return;
 158         }
 159
 160         /* FIXED attributes are never removed */
 161         if (a->flags & LDB_ATTR_FLAG_FIXED) {
 162                 return;
 163         }
 164
 165         if (a->flags & LDB_ATTR_FLAG_ALLOCATED) {
 166                 talloc_free(discard_const_p(char, a->name));
 167         }
 168
 169         i = a - ldb->schema.attributes;
 170         if (i < ldb->schema.num_attributes - 1) {
 171                 memmove(&ldb->schema.attributes[i],
 172                         a+1, sizeof(*a) * (ldb->schema.num_attributes-(i+1)));
 173         }
 174
 175         ldb->schema.num_attributes--;
 176 }
 177
 178 /*
 179   setup a attribute handler using a standard syntax
 180 */
 181 int ldb_schema_attribute_add(struct ldb_context *ldb,
 182                              const char *attribute,
 183                              unsigned flags,
 184                              const char *syntax)
 185 {
 186         const struct ldb_schema_syntax *s = ldb_standard_syntax_by_name(ldb, syntax);
 187         return ldb_schema_attribute_add_with_syntax(ldb, attribute, flags, s);
 188 }
 189
 190 /*
 191   setup the attribute handles for well known attributes
 192 */
 193 int ldb_setup_wellknown_attributes(struct ldb_context *ldb)
 194 {
 195         const struct {
 196                 const char *attr;
 197                 const char *syntax;
 198         } wellknown[] = {
 199                 { "dn", LDB_SYNTAX_DN },
 200                 { "distinguishedName", LDB_SYNTAX_DN },
 201                 { "cn", LDB_SYNTAX_DIRECTORY_STRING },
 202                 { "dc", LDB_SYNTAX_DIRECTORY_STRING },
 203                 { "ou", LDB_SYNTAX_DIRECTORY_STRING },
 204                 { "objectClass", LDB_SYNTAX_OBJECTCLASS }
 205         };
 206         int i;
 207         int ret;
 208
 209         for (i=0;i<ARRAY_SIZE(wellknown);i++) {
 210                 ret = ldb_schema_attribute_add(ldb, wellknown[i].attr, 0,
 211                                                wellknown[i].syntax);
 212                 if (ret != LDB_SUCCESS) {
 213                         return ret;
 214                 }
 215         }
 216
 217         return LDB_SUCCESS;
 218 }
 219