source4/dsdb/samdb/ldb_modules/anr.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2007
   5    Copyright (C) Simo Sorce <idra@samba.org> 2008
   6    Copyright (C) Andrew Tridgell  2004
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 /*
  23  *  Name: ldb
  24  *
  25  *  Component: ldb anr module
  26  *
  27  *  Description: module to implement 'ambiguous name resolution'
  28  *
  29  *  Author: Andrew Bartlett
  30  */
  31
  32 #include "includes.h"
  33 #include "ldb_module.h"
  34 #include "dsdb/samdb/samdb.h"
  35 #include "dsdb/samdb/ldb_modules/util.h"
  36
  37 #undef strcasecmp
  38
  39 /**
  40  * Make a and 'and' or 'or' tree from the two supplied elements
  41  */
  42 static struct ldb_parse_tree *make_parse_list(struct ldb_module *module,
  43                                        TALLOC_CTX *mem_ctx, enum ldb_parse_op op,
  44                                        struct ldb_parse_tree *first_arm, struct ldb_parse_tree *second_arm)
  45 {
  46         struct ldb_context *ldb;
  47         struct ldb_parse_tree *list;
  48
  49         ldb = ldb_module_get_ctx(module);
  50
  51         list = talloc(mem_ctx, struct ldb_parse_tree);
  52         if (list == NULL){
  53                 ldb_oom(ldb);
  54                 return NULL;
  55         }
  56         list->operation = op;
  57
  58         list->u.list.num_elements = 2;
  59         list->u.list.elements = talloc_array(list, struct ldb_parse_tree *, 2);
  60         if (!list->u.list.elements) {
  61                 ldb_oom(ldb);
  62                 return NULL;
  63         }
  64         list->u.list.elements[0] = talloc_steal(list, first_arm);
  65         list->u.list.elements[1] = talloc_steal(list, second_arm);
  66         return list;
  67 }
  68
  69 /**
  70  * Make an equality or prefix match tree, from the attribute, operation and matching value supplied
  71  */
  72 static struct ldb_parse_tree *make_match_tree(struct ldb_module *module,
  73                                               TALLOC_CTX *mem_ctx,
  74                                               enum ldb_parse_op op,
  75                                               const char *attr,
  76                                               struct ldb_val *match)
  77 {
  78         struct ldb_context *ldb;
  79         struct ldb_parse_tree *match_tree;
  80
  81         ldb = ldb_module_get_ctx(module);
  82
  83         match_tree = talloc(mem_ctx, struct ldb_parse_tree);
  84
  85         /* Depending on what type of match was selected, fill in the right part of the union */
  86
  87         match_tree->operation = op;
  88         switch (op) {
  89         case LDB_OP_SUBSTRING:
  90                 match_tree->u.substring.attr = attr;
  91
  92                 match_tree->u.substring.start_with_wildcard = 0;
  93                 match_tree->u.substring.end_with_wildcard = 1;
  94                 match_tree->u.substring.chunks = talloc_array(match_tree, struct ldb_val *, 2);
  95
  96                 if (match_tree->u.substring.chunks == NULL){
  97                         talloc_free(match_tree);
  98                         ldb_oom(ldb);
  99                         return NULL;
 100                 }
 101                 match_tree->u.substring.chunks[0] = match;
 102                 match_tree->u.substring.chunks[1] = NULL;
 103                 break;
 104         case LDB_OP_EQUALITY:
 105                 match_tree->u.equality.attr = attr;
 106                 match_tree->u.equality.value = *match;
 107                 break;
 108         default:
 109                 talloc_free(match_tree);
 110                 return NULL;
 111         }
 112         return match_tree;
 113 }
 114
 115 struct anr_context {
 116         bool found_anr;
 117         struct ldb_module *module;
 118         struct ldb_request *req;
 119 };
 120
 121 /**
 122  * Given the match for an 'ambigious name resolution' query, create a
 123  * parse tree with an 'or' of all the anr attributes in the schema.
 124  */
 125
 126 /**
 127  * Callback function to do the heavy lifting for the parse tree walker
 128  */
 129 static int anr_replace_value(struct anr_context *ac,
 130                              TALLOC_CTX *mem_ctx,
 131                              struct ldb_val *match,
 132                              struct ldb_parse_tree **ntree)
 133 {
 134         struct ldb_parse_tree *tree = NULL;
 135         struct ldb_module *module = ac->module;
 136         struct ldb_parse_tree *match_tree;
 137         struct dsdb_attribute *cur;
 138         const struct dsdb_schema *schema;
 139         struct ldb_context *ldb;
 140         uint8_t *p;
 141         enum ldb_parse_op op;
 142
 143         ldb = ldb_module_get_ctx(module);
 144
 145         schema = dsdb_get_schema(ldb, ac);
 146         if (!schema) {
 147                 ldb_asprintf_errstring(ldb, "no schema with which to construct anr filter");
 148                 return LDB_ERR_OPERATIONS_ERROR;
 149         }
 150
 151         if (match->length > 1 && match->data[0] == '=') {
 152                 struct ldb_val *match2 = talloc(mem_ctx, struct ldb_val);
 153                 if (match2 == NULL){
 154                         return ldb_oom(ldb);
 155                 }
 156                 *match2 = data_blob_const(match->data+1, match->length - 1);
 157                 match = match2;
 158                 op = LDB_OP_EQUALITY;
 159         } else {
 160                 op = LDB_OP_SUBSTRING;
 161         }
 162         for (cur = schema->attributes; cur; cur = cur->next) {
 163                 if (!(cur->searchFlags & SEARCH_FLAG_ANR)) continue;
 164                 match_tree = make_match_tree(module, mem_ctx, op, cur->lDAPDisplayName, match);
 165
 166                 if (tree) {
 167                         /* Inject an 'or' with the current tree */
 168                         tree = make_parse_list(module, mem_ctx,  LDB_OP_OR, tree, match_tree);
 169                         if (tree == NULL) {
 170                                 return ldb_oom(ldb);
 171                         }
 172                 } else {
 173                         tree = match_tree;
 174                 }
 175         }
 176
 177
 178         /* If the search term has a space in it,
 179            split it up at the first space.  */
 180
 181         p = memchr(match->data, ' ', match->length);
 182
 183         if (p) {
 184                 struct ldb_parse_tree *first_split_filter, *second_split_filter, *split_filters, *match_tree_1, *match_tree_2;
 185                 struct ldb_val *first_match = talloc(tree, struct ldb_val);
 186                 struct ldb_val *second_match = talloc(tree, struct ldb_val);
 187                 if (!first_match || !second_match) {
 188                         return ldb_oom(ldb);
 189                 }
 190                 *first_match = data_blob_const(match->data, p-match->data);
 191                 *second_match = data_blob_const(p+1, match->length - (p-match->data) - 1);
 192
 193                 /* Add (|(&(givenname=first)(sn=second))(&(givenname=second)(sn=first))) */
 194
 195                 match_tree_1 = make_match_tree(module, mem_ctx, op, "givenName", first_match);
 196                 match_tree_2 = make_match_tree(module, mem_ctx, op, "sn", second_match);
 197
 198                 first_split_filter = make_parse_list(module, ac,  LDB_OP_AND, match_tree_1, match_tree_2);
 199                 if (first_split_filter == NULL){
 200                         return ldb_oom(ldb);
 201                 }
 202
 203                 match_tree_1 = make_match_tree(module, mem_ctx, op, "sn", first_match);
 204                 match_tree_2 = make_match_tree(module, mem_ctx, op, "givenName", second_match);
 205
 206                 second_split_filter = make_parse_list(module, ac,  LDB_OP_AND, match_tree_1, match_tree_2);
 207                 if (second_split_filter == NULL){
 208                         return ldb_oom(ldb);
 209                 }
 210
 211                 split_filters = make_parse_list(module, mem_ctx,  LDB_OP_OR,
 212                                                 first_split_filter, second_split_filter);
 213                 if (split_filters == NULL) {
 214                         return ldb_oom(ldb);
 215                 }
 216
 217                 if (tree) {
 218                         /* Inject an 'or' with the current tree */
 219                         tree = make_parse_list(module, mem_ctx,  LDB_OP_OR, tree, split_filters);
 220                 } else {
 221                         tree = split_filters;
 222                 }
 223         }
 224         *ntree = tree;
 225         return LDB_SUCCESS;
 226 }
 227
 228 /*
 229   replace any occurrences of an attribute with a new, generated attribute tree
 230 */
 231 static int anr_replace_subtrees(struct anr_context *ac,
 232                                 struct ldb_parse_tree *tree,
 233                                 const char *attr,
 234                                 struct ldb_parse_tree **ntree)
 235 {
 236         int ret;
 237         unsigned int i;
 238
 239         switch (tree->operation) {
 240         case LDB_OP_AND:
 241         case LDB_OP_OR:
 242                 for (i=0;i<tree->u.list.num_elements;i++) {
 243                         ret = anr_replace_subtrees(ac, tree->u.list.elements[i],
 244                                                    attr, &tree->u.list.elements[i]);
 245                         if (ret != LDB_SUCCESS) {
 246                                 return ret;
 247                         }
 248                         *ntree = tree;
 249                 }
 250                 break;
 251         case LDB_OP_NOT:
 252                 ret = anr_replace_subtrees(ac, tree->u.isnot.child, attr, &tree->u.isnot.child);
 253                 if (ret != LDB_SUCCESS) {
 254                         return ret;
 255                 }
 256                 *ntree = tree;
 257                 break;
 258         case LDB_OP_EQUALITY:
 259                 if (ldb_attr_cmp(tree->u.equality.attr, attr) == 0) {
 260                         ret = anr_replace_value(ac, tree, &tree->u.equality.value, ntree);
 261                         if (ret != LDB_SUCCESS) {
 262                                 return ret;
 263                         }
 264                 }
 265                 break;
 266         case LDB_OP_SUBSTRING:
 267                 if (ldb_attr_cmp(tree->u.substring.attr, attr) == 0) {
 268                         if (tree->u.substring.start_with_wildcard == 0 &&
 269                             tree->u.substring.end_with_wildcard == 1 &&
 270                             tree->u.substring.chunks[0] != NULL &&
 271                             tree->u.substring.chunks[1] == NULL) {
 272                                 ret = anr_replace_value(ac, tree, tree->u.substring.chunks[0], ntree);
 273                                 if (ret != LDB_SUCCESS) {
 274                                         return ret;
 275                                 }
 276                         }
 277                 }
 278                 break;
 279         default:
 280                 break;
 281         }
 282
 283         return LDB_SUCCESS;
 284 }
 285
 286 struct anr_present_ctx {
 287         bool found_anr;
 288         const char *attr;
 289 };
 290
 291 /*
 292   callback to determine if ANR is in use at all
 293  */
 294 static int parse_tree_anr_present(struct ldb_parse_tree *tree, void *private_context)
 295 {
 296         struct anr_present_ctx *ctx = private_context;
 297         switch (tree->operation) {
 298         case LDB_OP_EQUALITY:
 299                 if (ldb_attr_cmp(tree->u.equality.attr, ctx->attr) == 0) {
 300                         ctx->found_anr = true;
 301                 }
 302                 break;
 303         case LDB_OP_GREATER:
 304         case LDB_OP_LESS:
 305         case LDB_OP_APPROX:
 306                 if (ldb_attr_cmp(tree->u.comparison.attr, ctx->attr) == 0) {
 307                         ctx->found_anr = true;
 308                 }
 309                 break;
 310         case LDB_OP_SUBSTRING:
 311                 if (ldb_attr_cmp(tree->u.substring.attr, ctx->attr) == 0) {
 312                         ctx->found_anr = true;
 313                 }
 314                 break;
 315         case LDB_OP_PRESENT:
 316                 if (ldb_attr_cmp(tree->u.present.attr, ctx->attr) == 0) {
 317                         ctx->found_anr = true;
 318                 }
 319                 break;
 320         case LDB_OP_EXTENDED:
 321                 if (tree->u.extended.attr &&
 322                     ldb_attr_cmp(tree->u.extended.attr, ctx->attr) == 0) {
 323                         ctx->found_anr = true;
 324                 }
 325                 break;
 326         default:
 327                 break;
 328         }
 329         return LDB_SUCCESS;
 330 }
 331
 332
 333 static int anr_search_callback(struct ldb_request *req, struct ldb_reply *ares)
 334 {
 335         struct anr_context *ac;
 336
 337         ac = talloc_get_type(req->context, struct anr_context);
 338
 339         if (!ares) {
 340                 return ldb_module_done(ac->req, NULL, NULL,
 341                                         LDB_ERR_OPERATIONS_ERROR);
 342         }
 343         if (ares->error != LDB_SUCCESS) {
 344                 return ldb_module_done(ac->req, ares->controls,
 345                                         ares->response, ares->error);
 346         }
 347
 348         switch (ares->type) {
 349         case LDB_REPLY_ENTRY:
 350                 return ldb_module_send_entry(ac->req, ares->message, ares->controls);
 351
 352         case LDB_REPLY_REFERRAL:
 353                 return ldb_module_send_referral(ac->req, ares->referral);
 354
 355         case LDB_REPLY_DONE:
 356                 return ldb_module_done(ac->req, ares->controls,
 357                                         ares->response, LDB_SUCCESS);
 358
 359         }
 360         return LDB_SUCCESS;
 361 }
 362
 363 /* search */
 364 static int anr_search(struct ldb_module *module, struct ldb_request *req)
 365 {
 366         struct ldb_context *ldb;
 367         struct ldb_parse_tree *anr_tree;
 368         struct ldb_request *down_req;
 369         struct anr_context *ac;
 370         struct anr_present_ctx ctx;
 371         const char *attr = "anr";
 372         int ret;
 373
 374         ctx.found_anr = false;
 375         ctx.attr = attr;
 376
 377         ldb_parse_tree_walk(req->op.search.tree,
 378                             parse_tree_anr_present,
 379                             &ctx);
 380
 381         if (!ctx.found_anr) {
 382                 return ldb_next_request(module, req);
 383         }
 384
 385         ldb = ldb_module_get_ctx(module);
 386
 387         ac = talloc(req, struct anr_context);
 388         if (!ac) {
 389                 return ldb_oom(ldb);
 390         }
 391
 392         ac->module = module;
 393         ac->req = req;
 394
 395 #if 0
 396         printf("oldanr : %s\n", ldb_filter_from_tree (0, req->op.search.tree));
 397 #endif
 398
 399         /* First make a copy, so we don't overwrite caller memory */
 400
 401         anr_tree = ldb_parse_tree_copy_shallow(ac, req->op.search.tree);
 402
 403         if (anr_tree == NULL) {
 404                 return ldb_operr(ldb);
 405         }
 406
 407         /* Now expand 'anr' out */
 408         ret = anr_replace_subtrees(ac, anr_tree, attr, &anr_tree);
 409         if (ret != LDB_SUCCESS) {
 410                 return ldb_operr(ldb);
 411         }
 412
 413         ret = ldb_build_search_req_ex(&down_req,
 414                                         ldb, ac,
 415                                         req->op.search.base,
 416                                         req->op.search.scope,
 417                                         anr_tree,
 418                                         req->op.search.attrs,
 419                                         req->controls,
 420                                         ac, anr_search_callback,
 421                                         req);
 422         LDB_REQ_SET_LOCATION(down_req);
 423         if (ret != LDB_SUCCESS) {
 424                 return ldb_operr(ldb);
 425         }
 426         talloc_steal(down_req, anr_tree);
 427
 428         return ldb_next_request(module, down_req);
 429 }
 430
 431 static const struct ldb_module_ops ldb_anr_module_ops = {
 432         .name              = "anr",
 433         .search = anr_search
 434 };
 435
 436 int ldb_anr_module_init(const char *version)
 437 {
 438         LDB_MODULE_CHECK_VERSION(version);
 439         return ldb_register_module(&ldb_anr_module_ops);
 440 }