source/lib/ldb/common/ldb_match.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Andrew Tridgell  2004-2005
   5    Copyright (C) Simo Sorce            2005
   6
   7      ** NOTE! The following LGPL license applies to the ldb
   8      ** library. This does NOT imply that all of Samba is released
   9      ** under the LGPL
  10
  11    This library is free software; you can redistribute it and/or
  12    modify it under the terms of the GNU Lesser General Public
  13    License as published by the Free Software Foundation; either
  14    version 2 of the License, or (at your option) any later version.
  15
  16    This library is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19    Lesser General Public License for more details.
  20
  21    You should have received a copy of the GNU Lesser General Public
  22    License along with this library; if not, write to the Free Software
  23    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24 */
  25
  26 /*
  27  *  Name: ldb
  28  *
  29  *  Component: ldb expression matching
  30  *
  31  *  Description: ldb expression matching
  32  *
  33  *  Author: Andrew Tridgell
  34  */
  35
  36 #include "includes.h"
  37 #include "ldb/include/includes.h"
  38
  39 /*
  40   check if the scope matches in a search result
  41 */
  42 static int ldb_match_scope(struct ldb_context *ldb,
  43                            const struct ldb_dn *base,
  44                            const struct ldb_dn *dn,
  45                            enum ldb_scope scope)
  46 {
  47         int ret = 0;
  48
  49         if (base == NULL || dn == NULL) {
  50                 return 1;
  51         }
  52
  53         switch (scope) {
  54         case LDB_SCOPE_BASE:
  55                 if (ldb_dn_compare(ldb, base, dn) == 0) {
  56                         ret = 1;
  57                 }
  58                 break;
  59
  60         case LDB_SCOPE_ONELEVEL:
  61                 if (ldb_dn_get_comp_num(dn) == (ldb_dn_get_comp_num(base) + 1)) {
  62                         if (ldb_dn_compare_base(ldb, base, dn) == 0) {
  63                                 ret = 1;
  64                         }
  65                 }
  66                 break;
  67
  68         case LDB_SCOPE_SUBTREE:
  69         default:
  70                 if (ldb_dn_compare_base(ldb, base, dn) == 0) {
  71                         ret = 1;
  72                 }
  73                 break;
  74         }
  75
  76         return ret;
  77 }
  78
  79
  80 /*
  81   match if node is present
  82 */
  83 static int ldb_match_present(struct ldb_context *ldb,
  84                              const struct ldb_message *msg,
  85                              const struct ldb_parse_tree *tree,
  86                              enum ldb_scope scope)
  87 {
  88         if (ldb_attr_dn(tree->u.present.attr) == 0) {
  89                 return 1;
  90         }
  91
  92         if (ldb_msg_find_element(msg, tree->u.present.attr)) {
  93                 return 1;
  94         }
  95
  96         return 0;
  97 }
  98
  99 static int ldb_match_comparison(struct ldb_context *ldb,
 100                                 const struct ldb_message *msg,
 101                                 const struct ldb_parse_tree *tree,
 102                                 enum ldb_scope scope,
 103                                 enum ldb_parse_op comp_op)
 104 {
 105         unsigned int i;
 106         struct ldb_message_element *el;
 107         const struct ldb_attrib_handler *h;
 108         int ret;
 109
 110         /* FIXME: APPROX comparison not handled yet */
 111         if (comp_op == LDB_OP_APPROX) return 0;
 112
 113         el = ldb_msg_find_element(msg, tree->u.comparison.attr);
 114         if (el == NULL) {
 115                 return 0;
 116         }
 117
 118         h = ldb_attrib_handler(ldb, el->name);
 119
 120         for (i = 0; i < el->num_values; i++) {
 121                 ret = h->comparison_fn(ldb, ldb, &el->values[i], &tree->u.comparison.value);
 122
 123                 if (ret == 0) {
 124                         return 1;
 125                 }
 126                 if (ret > 0 && comp_op == LDB_OP_GREATER) {
 127                         return 1;
 128                 }
 129                 if (ret < 0 && comp_op == LDB_OP_LESS) {
 130                         return 1;
 131                 }
 132         }
 133
 134         return 0;
 135 }
 136
 137 /*
 138   match a simple leaf node
 139 */
 140 static int ldb_match_equality(struct ldb_context *ldb,
 141                               const struct ldb_message *msg,
 142                               const struct ldb_parse_tree *tree,
 143                               enum ldb_scope scope)
 144 {
 145         unsigned int i;
 146         struct ldb_message_element *el;
 147         const struct ldb_attrib_handler *h;
 148         struct ldb_dn *valuedn;
 149         int ret;
 150
 151         if (ldb_attr_dn(tree->u.equality.attr) == 0) {
 152                 valuedn = ldb_dn_explode_casefold(ldb, ldb,
 153                                                   (char *)tree->u.equality.value.data);
 154                 if (valuedn == NULL) {
 155                         return 0;
 156                 }
 157
 158                 ret = ldb_dn_compare(ldb, msg->dn, valuedn);
 159
 160                 talloc_free(valuedn);
 161
 162                 if (ret == 0) return 1;
 163                 return 0;
 164         }
 165
 166         /* TODO: handle the "*" case derived from an extended search
 167            operation without the attibute type defined */
 168         el = ldb_msg_find_element(msg, tree->u.equality.attr);
 169         if (el == NULL) {
 170                 return 0;
 171         }
 172
 173         h = ldb_attrib_handler(ldb, el->name);
 174
 175         for (i=0;i<el->num_values;i++) {
 176                 if (h->comparison_fn(ldb, ldb, &tree->u.equality.value,
 177                                      &el->values[i]) == 0) {
 178                         return 1;
 179                 }
 180         }
 181
 182         return 0;
 183 }
 184
 185 static int ldb_wildcard_compare(struct ldb_context *ldb,
 186                                 const struct ldb_parse_tree *tree,
 187                                 const struct ldb_val value)
 188 {
 189         const struct ldb_attrib_handler *h;
 190         struct ldb_val val;
 191         struct ldb_val cnk;
 192         struct ldb_val *chunk;
 193         char *p, *g;
 194         uint8_t *save_p = NULL;
 195         int c = 0;
 196
 197         h = ldb_attrib_handler(ldb, tree->u.substring.attr);
 198
 199         if(h->canonicalise_fn(ldb, ldb, &value, &val) != 0)
 200                 return -1;
 201
 202         save_p = val.data;
 203         cnk.data = NULL;
 204
 205         if ( ! tree->u.substring.start_with_wildcard ) {
 206
 207                 chunk = tree->u.substring.chunks[c];
 208                 if(h->canonicalise_fn(ldb, ldb, chunk, &cnk) != 0) goto failed;
 209
 210                 /* This deals with wildcard prefix searches on binary attributes (eg objectGUID) */
 211                 if (cnk.length > val.length) {
 212                         goto failed;
 213                 }
 214                 if (memcmp((char *)val.data, (char *)cnk.data, cnk.length) != 0) goto failed;
 215                 val.length -= cnk.length;
 216                 val.data += cnk.length;
 217                 c++;
 218                 talloc_free(cnk.data);
 219                 cnk.data = NULL;
 220         }
 221
 222         while (tree->u.substring.chunks[c]) {
 223
 224                 chunk = tree->u.substring.chunks[c];
 225                 if(h->canonicalise_fn(ldb, ldb, chunk, &cnk) != 0) goto failed;
 226
 227                 /* FIXME: case of embedded nulls */
 228                 p = strstr((char *)val.data, (char *)cnk.data);
 229                 if (p == NULL) goto failed;
 230                 if ( (! tree->u.substring.chunks[c + 1]) && (! tree->u.substring.end_with_wildcard) ) {
 231                         do { /* greedy */
 232                                 g = strstr((char *)p + cnk.length, (char *)cnk.data);
 233                                 if (g) p = g;
 234                         } while(g);
 235                 }
 236                 val.length = val.length - (p - (char *)(val.data)) - cnk.length;
 237                 val.data = (uint8_t *)(p + cnk.length);
 238                 c++;
 239                 talloc_free(cnk.data);
 240                 cnk.data = NULL;
 241         }
 242
 243         if ( (! tree->u.substring.end_with_wildcard) && (*(val.data) != 0) ) goto failed; /* last chunk have not reached end of string */
 244         talloc_free(save_p);
 245         return 1;
 246
 247 failed:
 248         talloc_free(save_p);
 249         talloc_free(cnk.data);
 250         return 0;
 251 }
 252
 253 /*
 254   match a simple leaf node
 255 */
 256 static int ldb_match_substring(struct ldb_context *ldb,
 257                                const struct ldb_message *msg,
 258                                const struct ldb_parse_tree *tree,
 259                                enum ldb_scope scope)
 260 {
 261         unsigned int i;
 262         struct ldb_message_element *el;
 263
 264         el = ldb_msg_find_element(msg, tree->u.substring.attr);
 265         if (el == NULL) {
 266                 return 0;
 267         }
 268
 269         for (i = 0; i < el->num_values; i++) {
 270                 if (ldb_wildcard_compare(ldb, tree, el->values[i]) == 1) {
 271                         return 1;
 272                 }
 273         }
 274
 275         return 0;
 276 }
 277
 278
 279 /*
 280   bitwise-and comparator
 281 */
 282 static int ldb_comparator_and(const struct ldb_val *v1, const struct ldb_val *v2)
 283 {
 284         uint64_t i1, i2;
 285         i1 = strtoull((char *)v1->data, NULL, 0);
 286         i2 = strtoull((char *)v2->data, NULL, 0);
 287         return ((i1 & i2) == i2);
 288 }
 289
 290 /*
 291   bitwise-or comparator
 292 */
 293 static int ldb_comparator_or(const struct ldb_val *v1, const struct ldb_val *v2)
 294 {
 295         uint64_t i1, i2;
 296         i1 = strtoull((char *)v1->data, NULL, 0);
 297         i2 = strtoull((char *)v2->data, NULL, 0);
 298         return ((i1 & i2) != 0);
 299 }
 300
 301
 302 /*
 303   extended match, handles things like bitops
 304 */
 305 static int ldb_match_extended(struct ldb_context *ldb,
 306                               const struct ldb_message *msg,
 307                               const struct ldb_parse_tree *tree,
 308                               enum ldb_scope scope)
 309 {
 310         int i;
 311         const struct {
 312                 const char *oid;
 313                 int (*comparator)(const struct ldb_val *, const struct ldb_val *);
 314         } rules[] = {
 315                 { LDB_OID_COMPARATOR_AND, ldb_comparator_and},
 316                 { LDB_OID_COMPARATOR_OR, ldb_comparator_or}
 317         };
 318         int (*comp)(const struct ldb_val *, const struct ldb_val *) = NULL;
 319         struct ldb_message_element *el;
 320
 321         if (tree->u.extended.dnAttributes) {
 322                 ldb_debug(ldb, LDB_DEBUG_ERROR, "ldb: dnAttributes extended match not supported yet");
 323                 return -1;
 324         }
 325         if (tree->u.extended.rule_id == NULL) {
 326                 ldb_debug(ldb, LDB_DEBUG_ERROR, "ldb: no-rule extended matches not supported yet");
 327                 return -1;
 328         }
 329         if (tree->u.extended.attr == NULL) {
 330                 ldb_debug(ldb, LDB_DEBUG_ERROR, "ldb: no-attribute extended matches not supported yet");
 331                 return -1;
 332         }
 333
 334         for (i=0;i<ARRAY_SIZE(rules);i++) {
 335                 if (strcmp(rules[i].oid, tree->u.extended.rule_id) == 0) {
 336                         comp = rules[i].comparator;
 337                         break;
 338                 }
 339         }
 340         if (comp == NULL) {
 341                 ldb_debug(ldb, LDB_DEBUG_ERROR, "ldb: unknown extended rule_id %s\n",
 342                           tree->u.extended.rule_id);
 343                 return -1;
 344         }
 345
 346         /* find the message element */
 347         el = ldb_msg_find_element(msg, tree->u.extended.attr);
 348         if (el == NULL) {
 349                 return 0;
 350         }
 351
 352         for (i=0;i<el->num_values;i++) {
 353                 int ret = comp(&el->values[i], &tree->u.extended.value);
 354                 if (ret == -1 || ret == 1) return ret;
 355         }
 356
 357         return 0;
 358 }
 359
 360 /*
 361   return 0 if the given parse tree matches the given message. Assumes
 362   the message is in sorted order
 363
 364   return 1 if it matches, and 0 if it doesn't match
 365
 366   this is a recursive function, and does short-circuit evaluation
 367  */
 368 static int ldb_match_message(struct ldb_context *ldb,
 369                              const struct ldb_message *msg,
 370                              const struct ldb_parse_tree *tree,
 371                              enum ldb_scope scope)
 372 {
 373         unsigned int i;
 374         int v;
 375
 376         switch (tree->operation) {
 377         case LDB_OP_AND:
 378                 for (i=0;i<tree->u.list.num_elements;i++) {
 379                         v = ldb_match_message(ldb, msg, tree->u.list.elements[i], scope);
 380                         if (!v) return 0;
 381                 }
 382                 return 1;
 383
 384         case LDB_OP_OR:
 385                 for (i=0;i<tree->u.list.num_elements;i++) {
 386                         v = ldb_match_message(ldb, msg, tree->u.list.elements[i], scope);
 387                         if (v) return 1;
 388                 }
 389                 return 0;
 390
 391         case LDB_OP_NOT:
 392                 return ! ldb_match_message(ldb, msg, tree->u.isnot.child, scope);
 393
 394         case LDB_OP_EQUALITY:
 395                 return ldb_match_equality(ldb, msg, tree, scope);
 396
 397         case LDB_OP_SUBSTRING:
 398                 return ldb_match_substring(ldb, msg, tree, scope);
 399
 400         case LDB_OP_GREATER:
 401                 return ldb_match_comparison(ldb, msg, tree, scope, LDB_OP_GREATER);
 402
 403         case LDB_OP_LESS:
 404                 return ldb_match_comparison(ldb, msg, tree, scope, LDB_OP_LESS);
 405
 406         case LDB_OP_PRESENT:
 407                 return ldb_match_present(ldb, msg, tree, scope);
 408
 409         case LDB_OP_APPROX:
 410                 return ldb_match_comparison(ldb, msg, tree, scope, LDB_OP_APPROX);
 411
 412         case LDB_OP_EXTENDED:
 413                 return ldb_match_extended(ldb, msg, tree, scope);
 414
 415         }
 416
 417         return 0;
 418 }
 419
 420 int ldb_match_msg(struct ldb_context *ldb,
 421                   const struct ldb_message *msg,
 422                   const struct ldb_parse_tree *tree,
 423                   const struct ldb_dn *base,
 424                   enum ldb_scope scope)
 425 {
 426         if ( ! ldb_match_scope(ldb, base, msg->dn, scope) ) {
 427                 return 0;
 428         }
 429
 430         return ldb_match_message(ldb, msg, tree, scope);
 431 }